deps: update V8 to 8.3.110.9

PR-URL: https://github.com/nodejs/node/pull/32831
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1524 files changed, 57362 insertions, 26750 deletions

diff --git a/deps/v8/.git-blame-ignore-revs b/deps/v8/.git-blame-ignore-revs
index 5ae3977031..4c53e208e3 100644
--- a/deps/v8/.git-blame-ignore-revs
+++ b/deps/v8/.git-blame-ignore-revs
@@ -23,3 +23,6 @@ e50b49a0e38b34e2b28e026f4d1c7e0da0c7bb1a
 
 # Rewrite code base to use "." instead of "->" to access Object members.
 878ccb33bd3cf0e6dc018ff8d15843f585ac07be
+
+# Move test/mjsunit/regress-*.js => test/mjsunit/regress/
+cb67be1a3842fcf6a0da18aee444e3b7ea789e04
diff --git a/deps/v8/AUTHORS b/deps/v8/AUTHORS
index 819d147096..7036ecd42b 100644
--- a/deps/v8/AUTHORS
+++ b/deps/v8/AUTHORS
@@ -77,11 +77,13 @@ Daniel Andersson <kodandersson@gmail.com>
 Daniel Bevenius <daniel.bevenius@gmail.com>
 Daniel James <dnljms@gmail.com>
 David Carlier <devnexen@gmail.com>
+David Manouchehri <david@davidmanouchehri.com>
 Deepak Mohan <hop2deep@gmail.com>
 Deon Dior <diaoyuanjie@gmail.com>
 Dominic Farolini <domfarolino@gmail.com>
 Douglas Crosher <dtc-v8@scieneer.com>
 Dusan Milosavljevic <dusan.m.milosavljevic@gmail.com>
+Eric Rannaud <eric.rannaud@gmail.com>
 Erich Ocean <erich.ocean@me.com>
 Evan Lucas <evan.lucas@help.com>
 Fedor Indutny <fedor@indutny.com>
@@ -97,12 +99,14 @@ Henrique Ferreiro <henrique.ferreiro@gmail.com>
 Hirofumi Mako <mkhrfm@gmail.com>
 Honggyu Kim <honggyu.kp@gmail.com>
 Huáng Jùnliàng <jlhwung@gmail.com>
+Iain Ireland <iireland@mozilla.com>
 Ingvar Stepanyan <me@rreverser.com>
 Ioseb Dzmanashvili <ioseb.dzmanashvili@gmail.com>
 Isiah Meadows <impinball@gmail.com>
 Jaime Bernardo <jaime@janeasystems.com>
 Jan de Mooij <jandemooij@gmail.com>
 Jan Krems <jan.krems@gmail.com>
+Janusz Majnert <jmajnert@gmail.com>
 Jay Freeman <saurik@saurik.com>
 James Pike <g00gle@chilon.net>
 James M Snell <jasnell@gmail.com>
@@ -151,6 +155,7 @@ Oliver Dunk <oliver@oliverdunk.com>
 Paolo Giarrusso <p.giarrusso@gmail.com>
 Patrick Gansterer <paroga@paroga.com>
 Peng Fei <pfgenyun@gmail.com>
+Peng-Yu Chen <pengyu@libstarrify.so>
 Peter Rybin <peter.rybin@gmail.com>
 Peter Varga <pvarga@inf.u-szeged.hu>
 Peter Wong <peter.wm.wong@gmail.com>
@@ -195,6 +200,7 @@ Vladimir Krivosheev <develar@gmail.com>
 Vladimir Shutoff <vovan@shutoff.ru>
 Wenlu Wang <kingwenlu@gmail.com>
 Wiktor Garbacz <wiktor.garbacz@gmail.com>
+Wouter Vermeiren <wouter.vermeiren@essensium.com>
 Xiaoyin Liu <xiaoyin.l@outlook.com>
 Yannic Bonenberger <contact@yannic-bonenberger.com>
 Yong Wang <ccyongwang@tencent.com>
diff --git a/deps/v8/BUILD.gn b/deps/v8/BUILD.gn
index 0ffa2b794d..b2dde3f9d7 100644
--- a/deps/v8/BUILD.gn
+++ b/deps/v8/BUILD.gn
@@ -107,7 +107,7 @@ declare_args() {
 
   # Enable pointer compression (sets -dV8_COMPRESS_POINTERS).
   v8_enable_pointer_compression = ""
-  v8_enable_31bit_smis_on_64bit_arch = true
+  v8_enable_31bit_smis_on_64bit_arch = false
 
   # Sets -dOBJECT_PRINT.
   v8_enable_object_print = ""
@@ -128,7 +128,7 @@ declare_args() {
   v8_enable_concurrent_marking = true
 
   # Sets -dV8_ARRAY_BUFFER_EXTENSION
-  v8_enable_array_buffer_extension = false
+  v8_enable_array_buffer_extension = true
 
   # Enables various testing features.
   v8_enable_test_features = ""
@@ -211,6 +211,13 @@ declare_args() {
   # Enable additional targets necessary for verification of torque
   # file generation
   v8_verify_torque_generation_invariance = false
+
+  # Disable all snapshot compression.
+  v8_enable_snapshot_compression = true
+
+  # Enable control-flow integrity features, such as pointer authentication for
+  # ARM64.
+  v8_control_flow_integrity = false
 }
 
 # Derived defaults.
@@ -270,6 +277,9 @@ assert(!v8_disable_write_barriers || v8_enable_single_generation,
 assert(v8_current_cpu != "x86" || !v8_untrusted_code_mitigations,
        "Untrusted code mitigations are unsupported on ia32")
 
+assert(v8_current_cpu == "arm64" || !v8_control_flow_integrity,
+       "Control-flow integrity is only supported on arm64")
+
 assert(
     !v8_enable_pointer_compression || !v8_enable_shared_ro_heap,
     "Pointer compression is not supported with shared read-only heap enabled")
@@ -298,6 +308,7 @@ config("internal_config") {
     "//build/config/compiler:wexit_time_destructors",
     ":internal_config_base",
     ":v8_header_features",
+    ":v8_tracing_config",
   ]
 
   if (is_component_build) {
@@ -305,6 +316,17 @@ config("internal_config") {
   }
 }
 
+# Should be applied to all targets that write trace events.
+config("v8_tracing_config") {
+  if (v8_use_perfetto) {
+    include_dirs = [
+      "third_party/perfetto/include",
+      "$root_gen_dir/third_party/perfetto",
+      "$root_gen_dir/third_party/perfetto/build_config",
+    ]
+  }
+}
+
 # This config should be applied to code using the libplatform.
 config("libplatform_config") {
   include_dirs = [ "include" ]
@@ -501,6 +523,15 @@ config("features") {
   if (v8_enable_regexp_interpreter_threaded_dispatch) {
     defines += [ "V8_ENABLE_REGEXP_INTERPRETER_THREADED_DISPATCH" ]
   }
+  if (v8_enable_snapshot_compression) {
+    defines += [ "V8_SNAPSHOT_COMPRESSION" ]
+  }
+  if (v8_control_flow_integrity) {
+    defines += [ "V8_ENABLE_CONTROL_FLOW_INTEGRITY" ]
+  }
+  if (v8_enable_wasm_gdb_remote_debugging) {
+    defines += [ "V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING" ]
+  }
 }
 
 config("toolchain") {
@@ -543,6 +574,12 @@ config("toolchain") {
   }
   if (v8_current_cpu == "arm64") {
     defines += [ "V8_TARGET_ARCH_ARM64" ]
+    if (v8_control_flow_integrity) {
+      # TODO(v8:10026): Enable this in src/build.
+      if (current_cpu == "arm64") {
+        cflags += [ "-mbranch-protection=standard" ]
+      }
+    }
   }
 
   # Mips64el/mipsel simulators.
@@ -618,6 +655,7 @@ config("toolchain") {
   }
   if (v8_current_cpu == "s390" || v8_current_cpu == "s390x") {
     defines += [ "V8_TARGET_ARCH_S390" ]
+    cflags += [ "-ffp-contract=off" ]
     if (v8_current_cpu == "s390x") {
       defines += [ "V8_TARGET_ARCH_S390X" ]
     }
@@ -628,8 +666,9 @@ config("toolchain") {
     }
   }
   if (v8_current_cpu == "ppc" || v8_current_cpu == "ppc64") {
-    defines += [ "V8_TARGET_ARCH_PPC" ]
-    if (v8_current_cpu == "ppc64") {
+    if (v8_current_cpu == "ppc") {
+      defines += [ "V8_TARGET_ARCH_PPC" ]
+    } else if (v8_current_cpu == "ppc64") {
       defines += [ "V8_TARGET_ARCH_PPC64" ]
     }
     if (host_byteorder == "little") {
@@ -1138,11 +1177,14 @@ template("run_torque") {
       "bit-fields-tq.h",
       "builtin-definitions-tq.h",
       "interface-descriptors-tq.inc",
+      "factory-tq.cc",
+      "factory-tq.inc",
       "field-offsets-tq.h",
       "class-verifiers-tq.cc",
       "class-verifiers-tq.h",
       "enum-verifiers-tq.cc",
       "objects-printer-tq.cc",
+      "objects-body-descriptors-tq-inl.h",
       "class-definitions-tq.cc",
       "class-definitions-tq-inl.h",
       "class-definitions-tq.h",
@@ -1264,6 +1306,7 @@ v8_source_set("torque_generated_definitions") {
     "$target_gen_dir/torque-generated/class-definitions-tq.cc",
     "$target_gen_dir/torque-generated/class-verifiers-tq.cc",
     "$target_gen_dir/torque-generated/class-verifiers-tq.h",
+    "$target_gen_dir/torque-generated/factory-tq.cc",
     "$target_gen_dir/torque-generated/objects-printer-tq.cc",
   ]
 
@@ -1631,11 +1674,16 @@ v8_source_set("v8_initializers") {
       ### gcmole(arch:mips64el) ###
       "src/builtins/mips64/builtins-mips64.cc",
     ]
-  } else if (v8_current_cpu == "ppc" || v8_current_cpu == "ppc64") {
+  } else if (v8_current_cpu == "ppc") {
     sources += [
       ### gcmole(arch:ppc) ###
       "src/builtins/ppc/builtins-ppc.cc",
     ]
+  } else if (v8_current_cpu == "ppc64") {
+    sources += [
+      ### gcmole(arch:ppc64) ###
+      "src/builtins/ppc/builtins-ppc.cc",
+    ]
   } else if (v8_current_cpu == "s390" || v8_current_cpu == "s390x") {
     sources += [
       ### gcmole(arch:s390) ###
@@ -1684,6 +1732,7 @@ v8_header_set("v8_headers") {
   public_configs = [ ":v8_header_features" ]
 
   sources = [
+    "include/v8-fast-api-calls.h",
     "include/v8-internal.h",
     "include/v8.h",
     "include/v8config.h",
@@ -1865,7 +1914,6 @@ v8_compiler_sources = [
   "src/compiler/memory-optimizer.cc",
   "src/compiler/memory-optimizer.h",
   "src/compiler/node-aux-data.h",
-  "src/compiler/node-cache.cc",
   "src/compiler/node-cache.h",
   "src/compiler/node-marker.cc",
   "src/compiler/node-marker.h",
@@ -2005,6 +2053,7 @@ v8_source_set("v8_base_without_compiler") {
 
     ### gcmole(all) ###
     "$target_gen_dir/builtins-generated/bytecodes-builtins-list.h",
+    "include/v8-fast-api-calls.h",
     "include/v8-inspector-protocol.h",
     "include/v8-inspector.h",
     "include/v8-internal.h",
@@ -2235,6 +2284,9 @@ v8_source_set("v8_base_without_compiler") {
     "src/execution/messages.h",
     "src/execution/microtask-queue.cc",
     "src/execution/microtask-queue.h",
+    "src/execution/off-thread-isolate.cc",
+    "src/execution/off-thread-isolate.h",
+    "src/execution/pointer-authentication.h",
     "src/execution/protectors-inl.h",
     "src/execution/protectors.cc",
     "src/execution/protectors.h",
@@ -2273,6 +2325,9 @@ v8_source_set("v8_base_without_compiler") {
     "src/handles/handles-inl.h",
     "src/handles/handles.cc",
     "src/handles/handles.h",
+    "src/handles/local-handles-inl.h",
+    "src/handles/local-handles.cc",
+    "src/handles/local-handles.h",
     "src/handles/maybe-handles-inl.h",
     "src/handles/maybe-handles.h",
     "src/heap/array-buffer-collector.cc",
@@ -2298,6 +2353,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/heap/factory-inl.h",
     "src/heap/factory.cc",
     "src/heap/factory.h",
+    "src/heap/finalization-registry-cleanup-task.cc",
+    "src/heap/finalization-registry-cleanup-task.h",
     "src/heap/gc-idle-time-handler.cc",
     "src/heap/gc-idle-time-handler.h",
     "src/heap/gc-tracer.cc",
@@ -2321,6 +2378,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/heap/item-parallel-job.h",
     "src/heap/local-allocator-inl.h",
     "src/heap/local-allocator.h",
+    "src/heap/local-heap.cc",
+    "src/heap/local-heap.h",
     "src/heap/mark-compact-inl.h",
     "src/heap/mark-compact.cc",
     "src/heap/mark-compact.h",
@@ -2346,6 +2405,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/heap/read-only-heap.cc",
     "src/heap/read-only-heap.h",
     "src/heap/remembered-set.h",
+    "src/heap/safepoint.cc",
+    "src/heap/safepoint.h",
     "src/heap/scavenge-job.cc",
     "src/heap/scavenge-job.h",
     "src/heap/scavenger-inl.h",
@@ -2446,6 +2507,7 @@ v8_source_set("v8_base_without_compiler") {
     "src/logging/log-utils.h",
     "src/logging/log.cc",
     "src/logging/log.h",
+    "src/logging/off-thread-logger.h",
     "src/numbers/bignum-dtoa.cc",
     "src/numbers/bignum-dtoa.h",
     "src/numbers/bignum.cc",
@@ -2688,6 +2750,7 @@ v8_source_set("v8_base_without_compiler") {
     "src/objects/tagged-impl-inl.h",
     "src/objects/tagged-impl.cc",
     "src/objects/tagged-impl.h",
+    "src/objects/tagged-index.h",
     "src/objects/tagged-value-inl.h",
     "src/objects/tagged-value.h",
     "src/objects/template-objects-inl.h",
@@ -2773,6 +2836,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/regexp/regexp-compiler.h",
     "src/regexp/regexp-dotprinter.cc",
     "src/regexp/regexp-dotprinter.h",
+    "src/regexp/regexp-error.cc",
+    "src/regexp/regexp-error.h",
     "src/regexp/regexp-interpreter.cc",
     "src/regexp/regexp-interpreter.h",
     "src/regexp/regexp-macro-assembler-arch.h",
@@ -2858,6 +2923,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/snapshot/serializer.cc",
     "src/snapshot/serializer.h",
     "src/snapshot/snapshot-common.cc",
+    "src/snapshot/snapshot-compression.cc",
+    "src/snapshot/snapshot-compression.h",
     "src/snapshot/snapshot-source-sink.cc",
     "src/snapshot/snapshot-source-sink.h",
     "src/snapshot/snapshot.h",
@@ -2964,6 +3031,8 @@ v8_source_set("v8_base_without_compiler") {
     "src/wasm/wasm-code-manager.cc",
     "src/wasm/wasm-code-manager.h",
     "src/wasm/wasm-constants.h",
+    "src/wasm/wasm-debug-evaluate.cc",
+    "src/wasm/wasm-debug-evaluate.h",
     "src/wasm/wasm-debug.cc",
     "src/wasm/wasm-engine.cc",
     "src/wasm/wasm-engine.h",
@@ -3010,10 +3079,30 @@ v8_source_set("v8_base_without_compiler") {
     "src/zone/zone.h",
   ]
 
+  if (!v8_control_flow_integrity) {
+    sources += [ "src/execution/pointer-authentication-dummy.h" ]
+  }
+
   if (v8_enable_third_party_heap) {
     sources += v8_third_party_heap_files
   }
 
+  if (v8_enable_wasm_gdb_remote_debugging) {
+    sources += [
+      "src/debug/wasm/gdb-server/gdb-server-thread.cc",
+      "src/debug/wasm/gdb-server/gdb-server-thread.h",
+      "src/debug/wasm/gdb-server/gdb-server.cc",
+      "src/debug/wasm/gdb-server/gdb-server.h",
+      "src/debug/wasm/gdb-server/session.cc",
+      "src/debug/wasm/gdb-server/session.h",
+      "src/debug/wasm/gdb-server/target.cc",
+      "src/debug/wasm/gdb-server/target.h",
+      "src/debug/wasm/gdb-server/transport.cc",
+      "src/debug/wasm/gdb-server/transport.h",
+      "src/debug/wasm/gdb-server/util.h",
+    ]
+  }
+
   if (v8_check_header_includes) {
     # This file will be generated by tools/generate-header-include-checks.py
     # if the "check_v8_header_includes" gclient variable is set.
@@ -3167,6 +3256,9 @@ v8_source_set("v8_base_without_compiler") {
       "src/regexp/arm64/regexp-macro-assembler-arm64.h",
       "src/wasm/baseline/arm64/liftoff-assembler-arm64.h",
     ]
+    if (v8_control_flow_integrity) {
+      sources += [ "src/execution/arm64/pointer-authentication-arm64.h" ]
+    }
     if (is_win) {
       sources += [
         "src/diagnostics/unwinding-info-win64.cc",
@@ -3227,7 +3319,7 @@ v8_source_set("v8_base_without_compiler") {
       "src/regexp/mips64/regexp-macro-assembler-mips64.h",
       "src/wasm/baseline/mips64/liftoff-assembler-mips64.h",
     ]
-  } else if (v8_current_cpu == "ppc" || v8_current_cpu == "ppc64") {
+  } else if (v8_current_cpu == "ppc") {
     sources += [  ### gcmole(arch:ppc) ###
       "src/codegen/ppc/assembler-ppc-inl.h",
       "src/codegen/ppc/assembler-ppc.cc",
@@ -3257,6 +3349,36 @@ v8_source_set("v8_base_without_compiler") {
       "src/regexp/ppc/regexp-macro-assembler-ppc.h",
       "src/wasm/baseline/ppc/liftoff-assembler-ppc.h",
     ]
+  } else if (v8_current_cpu == "ppc64") {
+    sources += [  ### gcmole(arch:ppc64) ###
+      "src/codegen/ppc/assembler-ppc-inl.h",
+      "src/codegen/ppc/assembler-ppc.cc",
+      "src/codegen/ppc/assembler-ppc.h",
+      "src/codegen/ppc/constants-ppc.cc",
+      "src/codegen/ppc/constants-ppc.h",
+      "src/codegen/ppc/cpu-ppc.cc",
+      "src/codegen/ppc/interface-descriptors-ppc.cc",
+      "src/codegen/ppc/macro-assembler-ppc.cc",
+      "src/codegen/ppc/macro-assembler-ppc.h",
+      "src/codegen/ppc/register-ppc.h",
+      "src/compiler/backend/ppc/code-generator-ppc.cc",
+      "src/compiler/backend/ppc/instruction-codes-ppc.h",
+      "src/compiler/backend/ppc/instruction-scheduler-ppc.cc",
+      "src/compiler/backend/ppc/instruction-selector-ppc.cc",
+      "src/compiler/backend/ppc/unwinding-info-writer-ppc.cc",
+      "src/compiler/backend/ppc/unwinding-info-writer-ppc.h",
+      "src/debug/ppc/debug-ppc.cc",
+      "src/deoptimizer/ppc/deoptimizer-ppc.cc",
+      "src/diagnostics/ppc/disasm-ppc.cc",
+      "src/diagnostics/ppc/eh-frame-ppc.cc",
+      "src/execution/ppc/frame-constants-ppc.cc",
+      "src/execution/ppc/frame-constants-ppc.h",
+      "src/execution/ppc/simulator-ppc.cc",
+      "src/execution/ppc/simulator-ppc.h",
+      "src/regexp/ppc/regexp-macro-assembler-ppc.cc",
+      "src/regexp/ppc/regexp-macro-assembler-ppc.h",
+      "src/wasm/baseline/ppc/liftoff-assembler-ppc.h",
+    ]
   } else if (v8_current_cpu == "s390" || v8_current_cpu == "s390x") {
     sources += [  ### gcmole(arch:s390) ###
       "src/codegen/s390/assembler-s390-inl.h",
@@ -3357,7 +3479,10 @@ v8_source_set("v8_base_without_compiler") {
     ]
   }
 
-  deps += [ "//third_party/zlib" ]
+  deps += [
+    "//third_party/zlib",
+    "//third_party/zlib/google:compression_utils_portable",
+  ]
 
   if (v8_postmortem_support) {
     sources += [ "$target_gen_dir/debug-support.cc" ]
@@ -3519,6 +3644,7 @@ v8_component("v8_libbase") {
     "src/base/atomicops_internals_std.h",
     "src/base/base-export.h",
     "src/base/bit-field.h",
+    "src/base/bits-iterator.h",
     "src/base/bits.cc",
     "src/base/bits.h",
     "src/base/bounded-page-allocator.cc",
@@ -3797,6 +3923,47 @@ v8_source_set("fuzzer_support") {
   ]
 }
 
+v8_source_set("cppgc_base") {
+  visibility = [ ":*" ]
+
+  sources = [
+    "include/cppgc/allocation.h",
+    "include/cppgc/api-constants.h",
+    "include/cppgc/finalizer-trait.h",
+    "include/cppgc/garbage-collected.h",
+    "include/cppgc/gc-info.h",
+    "include/cppgc/heap.h",
+    "include/cppgc/platform.h",
+    "include/v8config.h",
+    "src/heap/cppgc/allocation.cc",
+    "src/heap/cppgc/gc-info-table.cc",
+    "src/heap/cppgc/gc-info-table.h",
+    "src/heap/cppgc/gc-info.cc",
+    "src/heap/cppgc/heap-inl.h",
+    "src/heap/cppgc/heap-object-header-inl.h",
+    "src/heap/cppgc/heap-object-header.cc",
+    "src/heap/cppgc/heap-object-header.h",
+    "src/heap/cppgc/heap.cc",
+    "src/heap/cppgc/heap.h",
+    "src/heap/cppgc/platform.cc",
+    "src/heap/cppgc/sanitizers.h",
+    "src/heap/cppgc/stack.cc",
+    "src/heap/cppgc/stack.h",
+  ]
+
+  if (target_cpu == "x64") {
+    if (is_win) {
+      sources += [ "src/heap/cppgc/asm/x64/push_registers_win.S" ]
+    } else {
+      sources += [ "src/heap/cppgc/asm/x64/push_registers.S" ]
+    }
+  }
+
+  configs = [ ":internal_config" ]
+
+  public_deps = [ ":v8_libbase" ]
+}
+
 ###############################################################################
 # Produce a single static library for embedders
 #
@@ -3843,6 +4010,12 @@ v8_static_library("wee8") {
   ]
 }
 
+v8_static_library("cppgc") {
+  deps = [ ":cppgc_base" ]
+
+  configs = [ ":internal_config" ]
+}
+
 ###############################################################################
 # Executables
 #
@@ -4074,7 +4247,7 @@ group("v8_archive") {
 if (is_fuchsia && !build_with_chromium) {
   import("//build/config/fuchsia/rules.gni")
 
-  fuchsia_package("d8_fuchsia_pkg") {
+  cr_fuchsia_package("d8_fuchsia_pkg") {
     testonly = true
     binary = ":d8"
     package_name_override = "d8"
@@ -4134,6 +4307,15 @@ if (is_component_build) {
 
     public_configs = [ ":external_config" ]
   }
+
+  v8_component("cppgc_for_testing") {
+    testonly = true
+
+    public_deps = [ ":cppgc_base" ]
+
+    configs = [ ":internal_config" ]
+    public_configs = [ ":external_config" ]
+  }
 } else {
   group("v8") {
     public_deps = [
@@ -4157,6 +4339,14 @@ if (is_component_build) {
 
     public_configs = [ ":external_config" ]
   }
+
+  group("cppgc_for_testing") {
+    testonly = true
+
+    public_deps = [ ":cppgc_base" ]
+
+    public_configs = [ ":external_config" ]
+  }
 }
 
 v8_executable("d8") {
@@ -4177,6 +4367,7 @@ v8_executable("d8") {
     # the :external_config applied to it by virtue of depending on :v8, and
     # you can't have both applied to the same target.
     ":internal_config_base",
+    ":v8_tracing_config",
   ]
 
   deps = [
@@ -4203,7 +4394,7 @@ v8_executable("d8") {
   }
 
   if (v8_use_perfetto) {
-    deps += [ "//third_party/perfetto/include/perfetto/tracing" ]
+    deps += [ "//third_party/perfetto/src/tracing:in_process_backend" ]
   }
 }
 
diff --git a/deps/v8/COMMON_OWNERS b/deps/v8/COMMON_OWNERS
index cf53fe80e0..1eee48173a 100644
--- a/deps/v8/COMMON_OWNERS
+++ b/deps/v8/COMMON_OWNERS
@@ -29,9 +29,11 @@ petermarshall@chromium.org
 rmcilroy@chromium.org
 sigurds@chromium.org
 solanes@chromium.org
+syg@chromium.org
 szuend@chromium.org
 tebbi@chromium.org
-titzer@chromium.org
 ulan@chromium.org
 verwaest@chromium.org
+victorgomes@chromium.org
 yangguo@chromium.org
+zhin@chromium.org
diff --git a/deps/v8/DEPS b/deps/v8/DEPS
index 880ff6c4b8..1bc687beaf 100644
--- a/deps/v8/DEPS
+++ b/deps/v8/DEPS
@@ -4,13 +4,9 @@
 
 gclient_gn_args_file = 'v8/build/config/gclient_args.gni'
 gclient_gn_args = [
-  'checkout_aemu'
 ]
 
 vars = {
-  # By Default, do not checkout AEMU, as it is too big, as is done in Chromium.
-  'checkout_aemu': False,
-
   # Fetches only the SDK boot images which match at least one of the whitelist
   # entries in a comma-separated list.
   #
@@ -35,10 +31,10 @@ vars = {
   'check_v8_header_includes': False,
 
   # GN CIPD package version.
-  'gn_version': 'git_revision:97cc440d84f050f99ff0161f9414bfa2ffa38f65',
+  'gn_version': 'git_revision:5ed3c9cc67b090d5e311e4bd2aba072173e82db9',
 
   # luci-go CIPD package version.
-  'luci_go': 'git_revision:37a855b64d59b7f079c9a0e5368f2757099d14d3',
+  'luci_go': 'git_revision:de73cf6c4bde86f0a9c8d54151b69b0154a398f1',
 
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling android_sdk_build-tools_version
@@ -69,10 +65,6 @@ vars = {
   # and whatever else without interference from each other.
   'android_sdk_sources_version': '4gxhM8E62bvZpQs7Q3d0DinQaW0RLCIefhXrQBFkNy8C',
   # Three lines of non-changing comments so that
-  # the commit queue can handle CLs rolling android_sdk_tools_version
-  # and whatever else without interference from each other.
-  'android_sdk_tools_version': 'wYcRQC2WHsw2dKWs4EA7fw9Qsyzu1ds1_fRjKmGxe5QC',
-  # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling android_sdk_tools-lint_version
   # and whatever else without interference from each other.
   'android_sdk_tools-lint_version': '89hXqZYzCum3delB5RV7J_QyWkaRodqdtQS0s3LMh3wC',
@@ -80,15 +72,15 @@ vars = {
 
 deps = {
   'v8/build':
-    Var('chromium_url') + '/chromium/src/build.git' + '@' + '2f17606c25956e800b6c4670c294a03620e78551',
+    Var('chromium_url') + '/chromium/src/build.git' + '@' + '26e9d485d01d6e0eb9dadd21df767a63494c8fea',
   'v8/third_party/depot_tools':
-    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + 'ea8b58b970c0c94b4a36270b806ee307547cd77e',
+    Var('chromium_url') + '/chromium/tools/depot_tools.git' + '@' + '2b2aec6506a810f8d7bd018609de2c2450b3c121',
   'v8/third_party/icu':
-    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'dbd3825b31041d782c5b504c59dcfb5ac7dda08c',
+    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + 'd7aff76cf6bb0fbef3afa6c07718f78a80a70f8f',
   'v8/third_party/instrumented_libraries':
     Var('chromium_url') + '/chromium/src/third_party/instrumented_libraries.git' + '@' + 'bb3f1802c237dd19105dd0f7919f99e536a39d10',
   'v8/buildtools':
-    Var('chromium_url') + '/chromium/src/buildtools.git' + '@' + 'afc5b798c72905e85f9991152be878714c579958',
+    Var('chromium_url') + '/chromium/src/buildtools.git' + '@' + '7977eb176752aeec29d888cfe8e677ac12ed1c41',
   'v8/buildtools/clang_format/script':
     Var('chromium_url') + '/chromium/llvm-project/cfe/tools/clang-format.git' + '@' + '96636aa0e9f047f17447f2d45a094d0b59ed7917',
   'v8/buildtools/linux64': {
@@ -112,11 +104,11 @@ deps = {
     'condition': 'host_os == "mac"',
   },
   'v8/buildtools/third_party/libc++/trunk':
-    Var('chromium_url') + '/chromium/llvm-project/libcxx.git' + '@' + '78d6a7767ed57b50122a161b91f59f19c9bd0d19',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxx.git' + '@' + 'd9040c75cfea5928c804ab7c235fed06a63f743a',
   'v8/buildtools/third_party/libc++abi/trunk':
-    Var('chromium_url') + '/chromium/llvm-project/libcxxabi.git' + '@' + '0d529660e32d77d9111912d73f2c74fc5fa2a858',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libcxxabi.git' + '@' + '196ba1aaa8ac285d94f4ea8d9836390a45360533',
   'v8/buildtools/third_party/libunwind/trunk':
-    Var('chromium_url') + '/external/llvm.org/libunwind.git' + '@' + '69d9b84cca8354117b9fe9705a4430d789ee599b',
+    Var('chromium_url') + '/external/github.com/llvm/llvm-project/libunwind.git' + '@' + '43bb9f872232f531bac80093ceb4de61c64b9ab7',
   'v8/buildtools/win': {
     'packages': [
       {
@@ -128,7 +120,7 @@ deps = {
     'condition': 'host_os == "win"',
   },
   'v8/base/trace_event/common':
-    Var('chromium_url') + '/chromium/src/base/trace_event/common.git' + '@' + 'bd79231eb1f9e7de2efb4ad79e530d9a7e70d9a5',
+    Var('chromium_url') + '/chromium/src/base/trace_event/common.git' + '@' + 'dab187b372fc17e51f5b9fad8201813d0aed5129',
   'v8/third_party/android_ndk': {
     'url': Var('chromium_url') + '/android_ndk.git' + '@' + '27c0a8d090c666a50e40fceb4ee5b40b1a2d3f87',
     'condition': 'checkout_android',
@@ -168,10 +160,6 @@ deps = {
               'version': Var('android_sdk_sources_version'),
           },
           {
-              'package': 'chromium/third_party/android_sdk/public/tools',
-              'version': Var('android_sdk_tools_version'),
-          },
-          {
               'package': 'chromium/third_party/android_sdk/public/tools-lint',
               'version': Var('android_sdk_tools-lint_version'),
           },
@@ -180,7 +168,7 @@ deps = {
       'dep_type': 'cipd',
   },
   'v8/third_party/catapult': {
-    'url': Var('chromium_url') + '/catapult.git' + '@' + '2e0a0cb9ad546be8c835e65d7537507cb7896e03',
+    'url': Var('chromium_url') + '/catapult.git' + '@' + '032c78376792ef343ea361bca2181ba6dec6b95f',
     'condition': 'checkout_android',
   },
   'v8/third_party/colorama/src': {
@@ -188,23 +176,23 @@ deps = {
     'condition': 'checkout_android',
   },
   'v8/third_party/fuchsia-sdk': {
-    'url': Var('chromium_url') + '/chromium/src/third_party/fuchsia-sdk.git' + '@' + '19c8ac5e150fbd147ec5987425a41aa9e97098b2',
+    'url': Var('chromium_url') + '/chromium/src/third_party/fuchsia-sdk.git' + '@' + '2457e41d8dc379f74662d3157e76339ba92cee06',
     'condition': 'checkout_fuchsia',
   },
   'v8/third_party/googletest/src':
-    Var('chromium_url') + '/external/github.com/google/googletest.git' + '@' + '306f3754a71d6d1ac644681d3544d06744914228',
+    Var('chromium_url') + '/external/github.com/google/googletest.git' + '@' + '10b1902d893ea8cc43c69541d70868f91af3646b',
   'v8/third_party/jinja2':
     Var('chromium_url') + '/chromium/src/third_party/jinja2.git' + '@' + 'b41863e42637544c2941b574c7877d3e1f663e25',
   'v8/third_party/markupsafe':
     Var('chromium_url') + '/chromium/src/third_party/markupsafe.git' + '@' + '8f45f5cfa0009d2a70589bcda0349b8cb2b72783',
   'v8/tools/swarming_client':
-    Var('chromium_url') + '/infra/luci/client-py.git' + '@' + '885b3febcc170a60f25795304e60927b77d1e92d',
+    Var('chromium_url') + '/infra/luci/client-py.git' + '@' + 'cc958279ffd6853e0a1b227a7e957ca334fe56af',
   'v8/test/benchmarks/data':
     Var('chromium_url') + '/v8/deps/third_party/benchmarks.git' + '@' + '05d7188267b4560491ff9155c5ee13e207ecd65f',
   'v8/test/mozilla/data':
     Var('chromium_url') + '/v8/deps/third_party/mozilla-tests.git' + '@' + 'f6c578a10ea707b1a8ab0b88943fe5115ce2b9be',
   'v8/test/test262/data':
-    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + '28b4fcca4b1b1d278dfe0cc0e69c7d9d59b31aab',
+    Var('chromium_url') + '/external/github.com/tc39/test262.git' + '@' + 'f6b2ccdd091ff82da54150796297c3a96d7edb41',
   'v8/test/test262/harness':
     Var('chromium_url') + '/external/github.com/test262-utils/test262-harness-py.git' + '@' + '4555345a943d0c99a9461182705543fb171dda4b',
   'v8/third_party/qemu-linux-x64': {
@@ -227,8 +215,28 @@ deps = {
       'condition': 'host_os == "mac" and checkout_fuchsia',
       'dep_type': 'cipd',
   },
+  'v8/third_party/aemu-linux-x64': {
+      'packages': [
+          {
+              'package': 'fuchsia/third_party/aemu/linux-amd64',
+              'version': '7YlCgase5GlIanqHn-nZClSlZ5kQETJyVUYRF7Jjy6UC'
+          },
+      ],
+      'condition': 'host_os == "linux" and checkout_fuchsia',
+      'dep_type': 'cipd',
+  },
+  'v8/third_party/aemu-mac-x64': {
+      'packages': [
+          {
+              'package': 'fuchsia/third_party/aemu/mac-amd64',
+              'version': 'T9bWxf8aUC5TwCFgPxpuW29Mfy-7Z9xCfXB9QO8MfU0C'
+          },
+      ],
+      'condition': 'host_os == "mac" and checkout_fuchsia',
+      'dep_type': 'cipd',
+  },
   'v8/tools/clang':
-    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + '535dbf16a84c7fc238f7ed11b5a75381407e38f6',
+    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + '105a8460911176861a422738eee4daad8dfe88a2',
   'v8/tools/luci-go': {
       'packages': [
         {
@@ -258,11 +266,11 @@ deps = {
     'dep_type': 'cipd',
   },
   'v8/third_party/perfetto':
-    Var('android_url') + '/platform/external/perfetto.git' + '@' + '12dc10e0278cded35205cf84f80a821348cb6c56',
+    Var('android_url') + '/platform/external/perfetto.git' + '@' + 'b9b24d1b0b80aafec393af085067e9eae829412f',
   'v8/third_party/protobuf':
     Var('chromium_url') + '/external/github.com/google/protobuf'+ '@' + 'b68a347f56137b4b1a746e8c7438495a6ac1bd91',
   'v8/third_party/zlib':
-    Var('chromium_url') + '/chromium/src/third_party/zlib.git'+ '@' + 'b9b9a5af7cca2e683e5f2aead8418e5bf9d5a7d5',
+    Var('chromium_url') + '/chromium/src/third_party/zlib.git'+ '@' + '156be8c52f80cde343088b4a69a80579101b6e67',
   'v8/third_party/ittapi': {
     # Force checkout ittapi libraries to pass v8 header includes check on
     # bots that has check_v8_header_includes enabled.
diff --git a/deps/v8/base/trace_event/common/trace_event_common.h b/deps/v8/base/trace_event/common/trace_event_common.h
index 3f741d816f..a7bffbdbeb 100644
--- a/deps/v8/base/trace_event/common/trace_event_common.h
+++ b/deps/v8/base/trace_event/common/trace_event_common.h
@@ -61,28 +61,30 @@
 // current process id, thread id, and a timestamp in microseconds.
 //
 // To trace an asynchronous procedure such as an IPC send/receive, use
-// ASYNC_BEGIN and ASYNC_END:
+// NESTABLE_ASYNC_BEGIN and NESTABLE_ASYNC_END:
 //   [single threaded sender code]
 //     static int send_count = 0;
 //     ++send_count;
-//     TRACE_EVENT_ASYNC_BEGIN0("ipc", "message", send_count);
+//     TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(
+//         "ipc", "message", TRACE_ID_LOCAL(send_count));
 //     Send(new MyMessage(send_count));
 //   [receive code]
 //     void OnMyMessage(send_count) {
-//       TRACE_EVENT_ASYNC_END0("ipc", "message", send_count);
+//       TRACE_NESTABLE_EVENT_ASYNC_END0(
+//           "ipc", "message", TRACE_ID_LOCAL(send_count));
 //     }
-// The third parameter is a unique ID to match ASYNC_BEGIN/ASYNC_END pairs.
-// ASYNC_BEGIN and ASYNC_END can occur on any thread of any traced process.
-// Pointers can be used for the ID parameter, and they will be annotated
-// internally so that the same pointer on two different processes will not
-// match. For example:
+// The third parameter is a unique ID to match NESTABLE_ASYNC_BEGIN/ASYNC_END
+// pairs. NESTABLE_ASYNC_BEGIN and ASYNC_END can occur on any thread of any
+// traced process. // Pointers can be used for the ID parameter, and they will
+// be annotated internally so that the same pointer on two different processes
+// will not match. For example:
 //   class MyTracedClass {
 //    public:
 //     MyTracedClass() {
-//       TRACE_EVENT_ASYNC_BEGIN0("category", "MyTracedClass", this);
+//       TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("category", "MyTracedClass", this);
 //     }
 //     ~MyTracedClass() {
-//       TRACE_EVENT_ASYNC_END0("category", "MyTracedClass", this);
+//       TRACE_EVENT_NESTABLE_ASYNC_END0("category", "MyTracedClass", this);
 //     }
 //   }
 //
@@ -512,9 +514,11 @@
                                    name, id, TRACE_EVENT_FLAG_NONE, arg1_name, \
                                    arg1_val)
 
-// ASYNC_STEP_* APIs should be only used by legacy code. New code should
-// consider using NESTABLE_ASYNC_* APIs to describe substeps within an async
-// event.
+// -- TRACE_EVENT_ASYNC is DEPRECATED! --
+//
+// TRACE_EVENT_ASYNC_* APIs should be only used by legacy code. New code should
+// use TRACE_EVENT_NESTABLE_ASYNC_* APIs instead.
+//
 // Records a single ASYNC_BEGIN event called "name" immediately, with 0, 1 or 2
 // associated arguments. If the category is not enabled, then this
 // does nothing.
@@ -566,9 +570,6 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID(                                        \
       TRACE_EVENT_PHASE_ASYNC_BEGIN, category_group, name, id,             \
       TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_ASYNC_BEGIN_WITH_FLAGS0(category_group, name, id, flags) \
-  INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_BEGIN,            \
-                                   category_group, name, id, flags)
 
 // Similar to TRACE_EVENT_ASYNC_BEGINx but with a custom |at| timestamp
 // provided.
@@ -595,11 +596,6 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                          \
       TRACE_EVENT_PHASE_ASYNC_BEGIN, category_group, name, id,                 \
       TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_ASYNC_BEGIN_WITH_TIMESTAMP_AND_FLAGS0(     \
-    category_group, name, id, timestamp, flags)                \
-  INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(          \
-      TRACE_EVENT_PHASE_ASYNC_BEGIN, category_group, name, id, \
-      TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, flags)
 
 // Records a single ASYNC_STEP_INTO event for |step| immediately. If the
 // category is not enabled, then this does nothing. The |name| and |id| must
@@ -671,9 +667,6 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID(                                      \
       TRACE_EVENT_PHASE_ASYNC_END, category_group, name, id,             \
       TRACE_EVENT_FLAG_COPY, arg1_name, arg1_val, arg2_name, arg2_val)
-#define TRACE_EVENT_ASYNC_END_WITH_FLAGS0(category_group, name, id, flags) \
-  INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_ASYNC_END,            \
-                                   category_group, name, id, flags)
 
 // Similar to TRACE_EVENT_ASYNC_ENDx but with a custom |at| timestamp provided.
 #define TRACE_EVENT_ASYNC_END_WITH_TIMESTAMP0(category_group, name, id, \
@@ -699,11 +692,6 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                        \
       TRACE_EVENT_PHASE_ASYNC_END, category_group, name, id,                 \
       TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_COPY)
-#define TRACE_EVENT_ASYNC_END_WITH_TIMESTAMP_AND_FLAGS0(category_group, name, \
-                                                        id, timestamp, flags) \
-  INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                         \
-      TRACE_EVENT_PHASE_ASYNC_END, category_group, name, id,                  \
-      TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, flags)
 
 // NESTABLE_ASYNC_* APIs are used to describe an async operation, which can
 // be nested within a NESTABLE_ASYNC event and/or have inner NESTABLE_ASYNC
@@ -742,6 +730,10 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID(                                            \
       TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, category_group, name, id,        \
       TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, arg2_name, arg2_val)
+#define TRACE_EVENT_NESTABLE_ASYNC_BEGIN_WITH_FLAGS0(category_group, name, id, \
+                                                     flags)                    \
+  INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN,     \
+                                   category_group, name, id, flags)
 // Records a single NESTABLE_ASYNC_END event called "name" immediately, with 0
 // or 2 associated arguments. If the category is not enabled, then this does
 // nothing.
@@ -761,6 +753,10 @@
   INTERNAL_TRACE_EVENT_ADD_WITH_ID(                                          \
       TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, category_group, name, id,        \
       TRACE_EVENT_FLAG_NONE, arg1_name, arg1_val, arg2_name, arg2_val)
+#define TRACE_EVENT_NESTABLE_ASYNC_END_WITH_FLAGS0(category_group, name, id, \
+                                                   flags)                    \
+  INTERNAL_TRACE_EVENT_ADD_WITH_ID(TRACE_EVENT_PHASE_NESTABLE_ASYNC_END,     \
+                                   category_group, name, id, flags)
 
 // Records a single NESTABLE_ASYNC_INSTANT event called "name" immediately,
 // with none, one or two associated argument. If the category is not enabled,
@@ -808,6 +804,11 @@
       TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, category_group, name, id,    \
       TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_NONE, \
       arg1_name, arg1_val)
+#define TRACE_EVENT_NESTABLE_ASYNC_BEGIN_WITH_TIMESTAMP_AND_FLAGS0(     \
+    category_group, name, id, timestamp, flags)                         \
+  INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                   \
+      TRACE_EVENT_PHASE_NESTABLE_ASYNC_BEGIN, category_group, name, id, \
+      TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, flags)
 #define TRACE_EVENT_NESTABLE_ASYNC_END_WITH_TIMESTAMP0(category_group, name, \
                                                        id, timestamp)        \
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                        \
@@ -826,6 +827,11 @@
       TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, category_group, name, id,      \
       TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, TRACE_EVENT_FLAG_NONE, \
       arg1_name, arg1_val, arg2_name, arg2_val)
+#define TRACE_EVENT_NESTABLE_ASYNC_END_WITH_TIMESTAMP_AND_FLAGS0(     \
+    category_group, name, id, timestamp, flags)                       \
+  INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                 \
+      TRACE_EVENT_PHASE_NESTABLE_ASYNC_END, category_group, name, id, \
+      TRACE_EVENT_API_CURRENT_THREAD_ID, timestamp, flags)
 #define TRACE_EVENT_NESTABLE_ASYNC_INSTANT_WITH_TIMESTAMP0(               \
     category_group, name, id, timestamp)                                  \
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_TID_AND_TIMESTAMP(                     \
diff --git a/deps/v8/gni/proto_library.gni b/deps/v8/gni/proto_library.gni
index b16d8f93bd..eca3ffb84e 100644
--- a/deps/v8/gni/proto_library.gni
+++ b/deps/v8/gni/proto_library.gni
@@ -124,9 +124,13 @@ template("proto_library") {
       rebase_path(proto_in_dir, root_build_dir),
     ]
     if (generate_cc) {
+      cc_generator_options_ = ""
+      if (defined(invoker.cc_generator_options)) {
+        cc_generator_options_ = invoker.cc_generator_options
+      }
       args += [
         "--cpp_out",
-        rel_cc_out_dir,
+        cc_generator_options_ + rel_cc_out_dir,
       ]
     }
     if (generate_descriptor != "") {
@@ -153,13 +157,9 @@ template("proto_library") {
 
     args += rebase_path(proto_sources, root_build_dir)
 
-    inputs = [
-      protoc_path,
-    ]
+    inputs = [ protoc_path ]
 
-    deps = [
-      protoc_label,
-    ]
+    deps = [ protoc_label ]
     if (generate_with_plugin) {
       inputs += [ plugin_path ]
       if (defined(plugin_host_label)) {
@@ -201,21 +201,23 @@ template("proto_library") {
       public_configs = []
     }
 
-    public_configs += [
-      "//:protobuf_gen_config",
-      ":$config_name",
-    ]
+    public_configs += [ "//:protobuf_gen_config" ]
+
+    propagate_imports_configs = !defined(invoker.propagate_imports_configs) ||
+                                invoker.propagate_imports_configs
+    if (propagate_imports_configs) {
+      public_configs += [ ":$config_name" ]
+    } else {
+      # Embedder handles include directory propagation to dependents.
+      configs += [ ":$config_name" ]
+    }
 
     # Use protobuf_full only for tests.
     if (defined(invoker.use_protobuf_full) &&
         invoker.use_protobuf_full == true) {
-      deps = [
-        "//:protobuf_full",
-      ]
+      deps = [ "//:protobuf_full" ]
     } else {
-      deps = [
-        "//:protobuf_lite",
-      ]
+      deps = [ "//:protobuf_lite" ]
     }
 
     deps += [ ":$action_name" ]
diff --git a/deps/v8/gni/v8.gni b/deps/v8/gni/v8.gni
index eaf76a471b..0b2806ca94 100644
--- a/deps/v8/gni/v8.gni
+++ b/deps/v8/gni/v8.gni
@@ -57,6 +57,12 @@ declare_args() {
   # Use Perfetto (https://perfetto.dev) as the default TracingController. Not
   # currently implemented.
   v8_use_perfetto = false
+
+  # Override global symbol level setting for v8
+  v8_symbol_level = symbol_level
+
+  # Enable WebAssembly debugging via GDB-remote protocol.
+  v8_enable_wasm_gdb_remote_debugging = false
 }
 
 if (v8_use_external_startup_data == "") {
@@ -109,6 +115,13 @@ if (is_debug && !v8_optimized_debug) {
   }
 }
 
+if (!is_debug) {
+  v8_remove_configs += [
+    # Too much performance impact, unclear security benefit.
+    "//build/config/compiler:default_init_stack_vars",
+  ]
+}
+
 if (v8_code_coverage && !is_clang) {
   v8_add_configs += [
     v8_path_prefix + ":v8_gcov_coverage_cflags",
@@ -116,6 +129,19 @@ if (v8_code_coverage && !is_clang) {
   ]
 }
 
+if (v8_symbol_level != symbol_level) {
+  v8_remove_configs += [ "//build/config/compiler:default_symbols" ]
+  if (v8_symbol_level == 0) {
+    v8_add_configs += [ "//build/config/compiler:no_symbols" ]
+  } else if (v8_symbol_level == 1) {
+    v8_add_configs += [ "//build/config/compiler:minimal_symbols" ]
+  } else if (v8_symbol_level == 2) {
+    v8_add_configs += [ "//build/config/compiler:symbols" ]
+  } else {
+    assert(false)
+  }
+}
+
 if ((is_posix || is_fuchsia) &&
     (v8_enable_backtrace || v8_monolithic || v8_expose_symbols)) {
   v8_remove_configs += [ "//build/config/gcc:symbol_visibility_hidden" ]
@@ -217,6 +243,25 @@ template("v8_component") {
   }
 }
 
+template("v8_shared_library") {
+  shared_library(target_name) {
+    forward_variables_from(invoker,
+                           "*",
+                           [
+                             "configs",
+                             "remove_configs",
+                           ])
+    configs -= v8_remove_configs
+    configs += v8_add_configs
+    if (defined(invoker.remove_configs)) {
+      configs -= invoker.remove_configs
+    }
+    if (defined(invoker.configs)) {
+      configs += invoker.configs
+    }
+  }
+}
+
 template("v8_static_library") {
   static_library(target_name) {
     complete_static_lib = true
diff --git a/deps/v8/include/OWNERS b/deps/v8/include/OWNERS
index 1e0794df7a..4f90a5c8c7 100644
--- a/deps/v8/include/OWNERS
+++ b/deps/v8/include/OWNERS
@@ -1,5 +1,6 @@
 adamk@chromium.org
 danno@chromium.org
+mlippautz@chromium.org
 ulan@chromium.org
 verwaest@chromium.org
 yangguo@chromium.org
diff --git a/deps/v8/include/cppgc/README.md b/deps/v8/include/cppgc/README.md
new file mode 100644
index 0000000000..3a2db6dfa9
--- /dev/null
+++ b/deps/v8/include/cppgc/README.md
@@ -0,0 +1,5 @@
+# C++ Garbage Collection
+
+This directory provides an open-source garbage collection library for C++.
+
+The library is under construction, meaning that *all APIs in this directory are incomplete and considered unstable and should not be used*.
\ No newline at end of file
diff --git a/deps/v8/include/cppgc/allocation.h b/deps/v8/include/cppgc/allocation.h
new file mode 100644
index 0000000000..3e717ad7d4
--- /dev/null
+++ b/deps/v8/include/cppgc/allocation.h
@@ -0,0 +1,91 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_ALLOCATION_H_
+#define INCLUDE_CPPGC_ALLOCATION_H_
+
+#include <stdint.h>
+#include <atomic>
+
+#include "include/cppgc/garbage-collected.h"
+#include "include/cppgc/gc-info.h"
+#include "include/cppgc/heap.h"
+#include "include/cppgc/internals.h"
+
+namespace cppgc {
+
+template <typename T>
+class MakeGarbageCollectedTraitBase;
+
+namespace internal {
+
+class V8_EXPORT MakeGarbageCollectedTraitInternal {
+ protected:
+  static inline void MarkObjectAsFullyConstructed(const void* payload) {
+    // See api_constants for an explanation of the constants.
+    std::atomic<uint16_t>* atomic_mutable_bitfield =
+        reinterpret_cast<std::atomic<uint16_t>*>(
+            const_cast<uint16_t*>(reinterpret_cast<const uint16_t*>(
+                reinterpret_cast<const uint8_t*>(payload) -
+                api_constants::kFullyConstructedBitFieldOffsetFromPayload)));
+    uint16_t value = atomic_mutable_bitfield->load(std::memory_order_relaxed);
+    value = value | api_constants::kFullyConstructedBitMask;
+    atomic_mutable_bitfield->store(value, std::memory_order_release);
+  }
+
+  static void* Allocate(cppgc::Heap* heap, size_t size, GCInfoIndex index);
+
+  friend class HeapObjectHeader;
+};
+
+}  // namespace internal
+
+// Users with custom allocation needs (e.g. overriding size) should override
+// MakeGarbageCollectedTrait (see below) and inherit their trait from
+// MakeGarbageCollectedTraitBase to get access to low-level primitives.
+template <typename T>
+class MakeGarbageCollectedTraitBase
+    : private internal::MakeGarbageCollectedTraitInternal {
+ protected:
+  // Allocates an object of |size| bytes on |heap|.
+  //
+  // TODO(mlippautz): Allow specifying arena for specific embedder uses.
+  static void* Allocate(Heap* heap, size_t size) {
+    return internal::MakeGarbageCollectedTraitInternal::Allocate(
+        heap, size, internal::GCInfoTrait<T>::Index());
+  }
+
+  // Marks an object as being fully constructed, resulting in precise handling
+  // by the garbage collector.
+  static void MarkObjectAsFullyConstructed(const void* payload) {
+    // internal::MarkObjectAsFullyConstructed(payload);
+    internal::MakeGarbageCollectedTraitInternal::MarkObjectAsFullyConstructed(
+        payload);
+  }
+};
+
+template <typename T>
+class MakeGarbageCollectedTrait : public MakeGarbageCollectedTraitBase<T> {
+ public:
+  template <typename... Args>
+  static T* Call(Heap* heap, Args&&... args) {
+    static_assert(internal::IsGarbageCollectedType<T>::value,
+                  "T needs to be a garbage collected object");
+    void* memory = MakeGarbageCollectedTraitBase<T>::Allocate(heap, sizeof(T));
+    T* object = ::new (memory) T(std::forward<Args>(args)...);
+    MakeGarbageCollectedTraitBase<T>::MarkObjectAsFullyConstructed(object);
+    return object;
+  }
+};
+
+// Default MakeGarbageCollected: Constructs an instance of T, which is a garbage
+// collected type.
+template <typename T, typename... Args>
+T* MakeGarbageCollected(Heap* heap, Args&&... args) {
+  return MakeGarbageCollectedTrait<T>::Call(heap, std::forward<Args>(args)...);
+}
+
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_ALLOCATION_H_
diff --git a/deps/v8/include/cppgc/finalizer-trait.h b/deps/v8/include/cppgc/finalizer-trait.h
new file mode 100644
index 0000000000..12216ed84e
--- /dev/null
+++ b/deps/v8/include/cppgc/finalizer-trait.h
@@ -0,0 +1,90 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_FINALIZER_TRAIT_H_
+#define INCLUDE_CPPGC_FINALIZER_TRAIT_H_
+
+#include <type_traits>
+
+#include "include/cppgc/internals.h"
+
+namespace cppgc {
+namespace internal {
+
+using FinalizationCallback = void (*)(void*);
+
+template <typename T, typename = void>
+struct HasFinalizeGarbageCollectedObject : std::false_type {};
+
+template <typename T>
+struct HasFinalizeGarbageCollectedObject<
+    T, void_t<decltype(std::declval<T>().FinalizeGarbageCollectedObject())>>
+    : std::true_type {};
+
+// The FinalizerTraitImpl specifies how to finalize objects.
+template <typename T, bool isFinalized>
+struct FinalizerTraitImpl;
+
+template <typename T>
+struct FinalizerTraitImpl<T, true> {
+ private:
+  // Dispatch to custom FinalizeGarbageCollectedObject().
+  struct Custom {
+    static void Call(void* obj) {
+      static_cast<T*>(obj)->FinalizeGarbageCollectedObject();
+    }
+  };
+
+  // Dispatch to regular destructor.
+  struct Destructor {
+    static void Call(void* obj) { static_cast<T*>(obj)->~T(); }
+  };
+
+  using FinalizeImpl =
+      std::conditional_t<HasFinalizeGarbageCollectedObject<T>::value, Custom,
+                         Destructor>;
+
+ public:
+  static void Finalize(void* obj) {
+    static_assert(sizeof(T), "T must be fully defined");
+    FinalizeImpl::Call(obj);
+  }
+};
+
+template <typename T>
+struct FinalizerTraitImpl<T, false> {
+  static void Finalize(void* obj) {
+    static_assert(sizeof(T), "T must be fully defined");
+  }
+};
+
+// The FinalizerTrait is used to determine if a type requires finalization and
+// what finalization means.
+template <typename T>
+struct FinalizerTrait {
+ private:
+  // Object has a finalizer if it has
+  // - a custom FinalizeGarbageCollectedObject method, or
+  // - a destructor.
+  static constexpr bool kNonTrivialFinalizer =
+      internal::HasFinalizeGarbageCollectedObject<T>::value ||
+      !std::is_trivially_destructible<typename std::remove_cv<T>::type>::value;
+
+  static void Finalize(void* obj) {
+    internal::FinalizerTraitImpl<T, kNonTrivialFinalizer>::Finalize(obj);
+  }
+
+ public:
+  // The callback used to finalize an object of type T.
+  static constexpr FinalizationCallback kCallback =
+      kNonTrivialFinalizer ? Finalize : nullptr;
+};
+
+template <typename T>
+constexpr FinalizationCallback FinalizerTrait<T>::kCallback;
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_FINALIZER_TRAIT_H_
diff --git a/deps/v8/include/cppgc/garbage-collected.h b/deps/v8/include/cppgc/garbage-collected.h
new file mode 100644
index 0000000000..6c62daafdc
--- /dev/null
+++ b/deps/v8/include/cppgc/garbage-collected.h
@@ -0,0 +1,53 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_GARBAGE_COLLECTED_H_
+#define INCLUDE_CPPGC_GARBAGE_COLLECTED_H_
+
+#include <type_traits>
+
+#include "include/cppgc/internals.h"
+#include "include/cppgc/platform.h"
+
+namespace cppgc {
+namespace internal {
+
+template <typename T, typename = void>
+struct IsGarbageCollectedType : std::false_type {
+  static_assert(sizeof(T), "T must be fully defined");
+};
+
+template <typename T>
+struct IsGarbageCollectedType<
+    T, void_t<typename std::remove_const_t<T>::IsGarbageCollectedTypeMarker>>
+    : std::true_type {
+  static_assert(sizeof(T), "T must be fully defined");
+};
+
+}  // namespace internal
+
+template <typename>
+class GarbageCollected {
+ public:
+  using IsGarbageCollectedTypeMarker = void;
+
+  // Must use MakeGarbageCollected.
+  void* operator new(size_t) = delete;
+  void* operator new[](size_t) = delete;
+  // The garbage collector is taking care of reclaiming the object. Also,
+  // virtual destructor requires an unambiguous, accessible 'operator delete'.
+  void operator delete(void*) {
+#ifdef V8_ENABLE_CHECKS
+    internal::Abort();
+#endif  // V8_ENABLE_CHECKS
+  }
+  void operator delete[](void*) = delete;
+
+ protected:
+  GarbageCollected() = default;
+};
+
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_GARBAGE_COLLECTED_H_
diff --git a/deps/v8/include/cppgc/gc-info.h b/deps/v8/include/cppgc/gc-info.h
new file mode 100644
index 0000000000..987ba34fa4
--- /dev/null
+++ b/deps/v8/include/cppgc/gc-info.h
@@ -0,0 +1,43 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_GC_INFO_H_
+#define INCLUDE_CPPGC_GC_INFO_H_
+
+#include <stdint.h>
+
+#include "include/cppgc/finalizer-trait.h"
+#include "include/v8config.h"
+
+namespace cppgc {
+namespace internal {
+
+using GCInfoIndex = uint16_t;
+
+class V8_EXPORT RegisteredGCInfoIndex final {
+ public:
+  RegisteredGCInfoIndex(FinalizationCallback finalization_callback,
+                        bool has_v_table);
+  GCInfoIndex GetIndex() const { return index_; }
+
+ private:
+  const GCInfoIndex index_;
+};
+
+// Trait determines how the garbage collector treats objects wrt. to traversing,
+// finalization, and naming.
+template <typename T>
+struct GCInfoTrait {
+  static GCInfoIndex Index() {
+    static_assert(sizeof(T), "T must be fully defined");
+    static const RegisteredGCInfoIndex registered_index(
+        FinalizerTrait<T>::kCallback, std::is_polymorphic<T>::value);
+    return registered_index.GetIndex();
+  }
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_GC_INFO_H_
diff --git a/deps/v8/include/cppgc/heap.h b/deps/v8/include/cppgc/heap.h
new file mode 100644
index 0000000000..a0568d534f
--- /dev/null
+++ b/deps/v8/include/cppgc/heap.h
@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_HEAP_H_
+#define INCLUDE_CPPGC_HEAP_H_
+
+#include <memory>
+
+#include "include/v8config.h"
+
+namespace cppgc {
+namespace internal {
+class Heap;
+}  // namespace internal
+
+class V8_EXPORT Heap {
+ public:
+  static std::unique_ptr<Heap> Create();
+
+  virtual ~Heap() = default;
+
+ private:
+  Heap() = default;
+
+  friend class internal::Heap;
+};
+
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_HEAP_H_
diff --git a/deps/v8/include/cppgc/internals.h b/deps/v8/include/cppgc/internals.h
new file mode 100644
index 0000000000..1e57779758
--- /dev/null
+++ b/deps/v8/include/cppgc/internals.h
@@ -0,0 +1,41 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_INTERNALS_H_
+#define INCLUDE_CPPGC_INTERNALS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "include/v8config.h"
+
+namespace cppgc {
+namespace internal {
+
+// Pre-C++17 custom implementation of std::void_t.
+template <typename... Ts>
+struct make_void {
+  typedef void type;
+};
+template <typename... Ts>
+using void_t = typename make_void<Ts...>::type;
+
+// Embedders should not rely on this code!
+
+// Internal constants to avoid exposing internal types on the API surface.
+namespace api_constants {
+// Offset of the uint16_t bitfield from the payload contaning the
+// in-construction bit. This is subtracted from the payload pointer to get
+// to the right bitfield.
+static constexpr size_t kFullyConstructedBitFieldOffsetFromPayload =
+    2 * sizeof(uint16_t);
+// Mask for in-construction bit.
+static constexpr size_t kFullyConstructedBitMask = size_t{1};
+
+}  // namespace api_constants
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_INTERNALS_H_
diff --git a/deps/v8/include/cppgc/platform.h b/deps/v8/include/cppgc/platform.h
new file mode 100644
index 0000000000..f216c2730a
--- /dev/null
+++ b/deps/v8/include/cppgc/platform.h
@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef INCLUDE_CPPGC_PLATFORM_H_
+#define INCLUDE_CPPGC_PLATFORM_H_
+
+#include "include/v8-platform.h"
+#include "include/v8config.h"
+
+namespace cppgc {
+
+// TODO(v8:10346): Put PageAllocator in a non-V8 include header to avoid
+// depending on namespace v8.
+using PageAllocator = v8::PageAllocator;
+
+// Initializes the garbage collector with the provided platform. Must be called
+// before creating a Heap.
+V8_EXPORT void InitializePlatform(PageAllocator* page_allocator);
+
+// Must be called after destroying the last used heap.
+V8_EXPORT void ShutdownPlatform();
+
+namespace internal {
+
+V8_EXPORT void Abort();
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_PLATFORM_H_
diff --git a/deps/v8/include/js_protocol.pdl b/deps/v8/include/js_protocol.pdl
index 28b8e61076..3f5410d1e1 100644
--- a/deps/v8/include/js_protocol.pdl
+++ b/deps/v8/include/js_protocol.pdl
@@ -119,6 +119,7 @@ domain Debugger
         script
         eval
         module
+        wasm-expression-stack
       # Object representing the scope. For `global` and `with` scopes it represents the actual
       # object; for the rest of the scopes, it is artificial transient object enumerating scope
       # variables as its properties.
@@ -273,6 +274,13 @@ domain Debugger
 
   # Resumes JavaScript execution.
   command resume
+    parameters
+      # Set to true to terminate execution upon resuming execution. In contrast
+      # to Runtime.terminateExecution, this will allows to execute further
+      # JavaScript (i.e. via evaluation) until execution of the paused code
+      # is actually resumed, at which point termination is triggered.
+      # If execution is currently not paused, this parameter has no effect.
+      optional boolean terminateOnResume
 
   # Searches for given string in script content.
   command searchInContent
@@ -496,6 +504,12 @@ domain Debugger
   # Fired when the virtual machine resumed execution.
   event resumed
 
+  # Enum of possible script languages.
+  type ScriptLanguage extends string
+    enum
+      JavaScript
+      WebAssembly
+
   # Fired when virtual machine fails to parse the script.
   event scriptFailedToParse
     parameters
@@ -527,6 +541,10 @@ domain Debugger
       optional integer length
       # JavaScript top stack frame of where the script parsed event was triggered if available.
       experimental optional Runtime.StackTrace stackTrace
+      # If the scriptLanguage is WebAssembly, the code section offset in the module.
+      experimental optional integer codeOffset
+      # The language of the script.
+      experimental optional Debugger.ScriptLanguage scriptLanguage
 
   # Fired when virtual machine parses script. This event is also fired for all known and uncollected
   # scripts upon enabling debugger.
@@ -562,6 +580,10 @@ domain Debugger
       optional integer length
       # JavaScript top stack frame of where the script parsed event was triggered if available.
       experimental optional Runtime.StackTrace stackTrace
+      # If the scriptLanguage is WebAssembly, the code section offset in the module.
+      experimental optional integer codeOffset
+      # The language of the script.
+      experimental optional Debugger.ScriptLanguage scriptLanguage
 
 experimental domain HeapProfiler
   depends on Runtime
@@ -824,6 +846,8 @@ domain Profiler
       optional boolean callCount
       # Collect block-based coverage.
       optional boolean detailed
+      # Allow the backend to send updates on its own initiative
+      optional boolean allowTriggeredUpdates
     returns
       # Monotonically increasing time (in seconds) when the coverage update was taken in the backend.
       number timestamp
@@ -931,7 +955,8 @@ domain Runtime
         boolean
         symbol
         bigint
-      # Object subtype hint. Specified for `object` type values only.
+        wasm
+      # Object subtype hint. Specified for `object` or `wasm` type values only.
       optional enum subtype
         array
         null
@@ -950,6 +975,11 @@ domain Runtime
         typedarray
         arraybuffer
         dataview
+        i32
+        i64
+        f32
+        f64
+        v128
       # Object class (constructor) name. Specified for `object` type values only.
       optional string className
       # Remote object value in case of primitive values or JSON values (if it was requested).
@@ -1306,7 +1336,9 @@ domain Runtime
       experimental optional TimeDelta timeout
       # Disable breakpoints during execution.
       experimental optional boolean disableBreaks
-      # Reserved flag for future REPL mode support. Setting this flag has currently no effect.
+      # Setting this flag to true enables `let` re-declaration and top-level `await`.
+      # Note that `let` variables can only be re-declared if they originate from
+      # `replMode` themselves.
       experimental optional boolean replMode
     returns
       # Evaluation result.
diff --git a/deps/v8/include/v8-fast-api-calls.h b/deps/v8/include/v8-fast-api-calls.h
new file mode 100644
index 0000000000..bfce66b652
--- /dev/null
+++ b/deps/v8/include/v8-fast-api-calls.h
@@ -0,0 +1,408 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * This file provides additional API on top of the default one for making
+ * API calls, which come from embedder C++ functions. The functions are being
+ * called directly from optimized code, doing all the necessary typechecks
+ * in the compiler itself, instead of on the embedder side. Hence the "fast"
+ * in the name. Example usage might look like:
+ *
+ * \code
+ *    void FastMethod(int param, bool another_param);
+ *
+ *    v8::FunctionTemplate::New(isolate, SlowCallback, data,
+ *                              signature, length, constructor_behavior
+ *                              side_effect_type,
+ *                              &v8::CFunction::Make(FastMethod));
+ * \endcode
+ *
+ * An example for custom embedder type support might employ a way to wrap/
+ * unwrap various C++ types in JSObject instances, e.g:
+ *
+ * \code
+ *
+ *    // Represents the way this type system maps C++ and JS values.
+ *    struct WrapperTypeInfo {
+ *      // Store e.g. a method to map from exposed C++ types to the already
+ *      // created v8::FunctionTemplate's for instantiating them.
+ *    };
+ *
+ *    // Helper method with a sanity check.
+ *    template <typename T, int offset>
+ *    inline T* GetInternalField(v8::Local<v8::Object> wrapper) {
+ *      assert(offset < wrapper->InternalFieldCount());
+ *      return reinterpret_cast<T*>(
+ *          wrapper->GetAlignedPointerFromInternalField(offset));
+ *    }
+ *
+ *    // Returns the type info from a wrapper JS object.
+ *    inline const WrapperTypeInfo* ToWrapperTypeInfo(
+ *        v8::Local<v8::Object> wrapper) {
+ *      return GetInternalField<WrapperTypeInfo,
+ *                              kV8EmbedderWrapperTypeIndex>(wrapper);
+ *    }
+ *
+ *    class CustomEmbedderType {
+ *     public:
+ *      static constexpr const WrapperTypeInfo* GetWrapperTypeInfo() {
+ *        return &custom_type_wrapper_type_info;
+ *      }
+ *      // Returns the raw C object from a wrapper JS object.
+ *      static CustomEmbedderType* Unwrap(v8::Local<v8::Object> wrapper) {
+ *        return GetInternalField<CustomEmbedderType,
+ *                                kV8EmbedderWrapperObjectIndex>(wrapper);
+ *      }
+ *      static void FastMethod(CustomEmbedderType* receiver, int param) {
+ *        assert(receiver != nullptr);
+ *        // Type checks are already done by the optimized code.
+ *        // Then call some performance-critical method like:
+ *        // receiver->Method(param);
+ *      }
+ *
+ *      static void SlowMethod(
+ *          const v8::FunctionCallbackInfo<v8::Value>& info) {
+ *        v8::Local<v8::Object> instance =
+ *          v8::Local<v8::Object>::Cast(info.Holder());
+ *        CustomEmbedderType* receiver = Unwrap(instance);
+ *        // TODO: Do type checks and extract {param}.
+ *        FastMethod(receiver, param);
+ *      }
+ *
+ *     private:
+ *      static const WrapperTypeInfo custom_type_wrapper_type_info;
+ *    };
+ *
+ *    // Support for custom embedder types via specialization of WrapperTraits.
+ *    namespace v8 {
+ *      template <>
+ *      class WrapperTraits<CustomEmbedderType> {
+ *        public:
+ *          static const void* GetTypeInfo() {
+ *            // We use the already defined machinery for the custom type.
+ *            return CustomEmbedderType::GetWrapperTypeInfo();
+ *          }
+ *      };
+ *    }  // namespace v8
+ *
+ *    // The constants kV8EmbedderWrapperTypeIndex and
+ *    // kV8EmbedderWrapperObjectIndex describe the offsets for the type info
+ *    // struct (the one returned by WrapperTraits::GetTypeInfo) and the
+ *    // native object, when expressed as internal field indices within a
+ *    // JSObject. The existance of this helper function assumes that all
+ *    // embedder objects have their JSObject-side type info at the same
+ *    // offset, but this is not a limitation of the API itself. For a detailed
+ *    // use case, see the third example.
+ *    static constexpr int kV8EmbedderWrapperTypeIndex = 0;
+ *    static constexpr int kV8EmbedderWrapperObjectIndex = 1;
+ *
+ *    // The following setup function can be templatized based on
+ *    // the {embedder_object} argument.
+ *    void SetupCustomEmbedderObject(v8::Isolate* isolate,
+ *                                   v8::Local<v8::Context> context,
+ *                                   CustomEmbedderType* embedder_object) {
+ *      isolate->set_embedder_wrapper_type_index(
+ *        kV8EmbedderWrapperTypeIndex);
+ *      isolate->set_embedder_wrapper_object_index(
+ *        kV8EmbedderWrapperObjectIndex);
+ *
+ *      v8::CFunction c_func =
+ *        MakeV8CFunction(CustomEmbedderType::FastMethod);
+ *
+ *      Local<v8::FunctionTemplate> method_template =
+ *        v8::FunctionTemplate::New(
+ *          isolate, CustomEmbedderType::SlowMethod, v8::Local<v8::Value>(),
+ *          v8::Local<v8::Signature>(), 1, v8::ConstructorBehavior::kAllow,
+ *          v8::SideEffectType::kHasSideEffect, &c_func);
+ *
+ *      v8::Local<v8::ObjectTemplate> object_template =
+ *        v8::ObjectTemplate::New(isolate);
+ *      object_template->SetInternalFieldCount(
+ *        kV8EmbedderWrapperObjectIndex + 1);
+ *      object_template->Set(
+            v8::String::NewFromUtf8Literal(isolate, "method"), method_template);
+ *
+ *      // Instantiate the wrapper JS object.
+ *      v8::Local<v8::Object> object =
+ *          object_template->NewInstance(context).ToLocalChecked();
+ *      object->SetAlignedPointerInInternalField(
+ *        kV8EmbedderWrapperObjectIndex,
+ *        reinterpret_cast<void*>(embedder_object));
+ *
+ *      // TODO: Expose {object} where it's necessary.
+ *    }
+ * \endcode
+ *
+ * For instance if {object} is exposed via a global "obj" variable,
+ * one could write in JS:
+ *   function hot_func() {
+ *     obj.method(42);
+ *   }
+ * and once {hot_func} gets optimized, CustomEmbedderType::FastMethod
+ * will be called instead of the slow version, with the following arguments:
+ *   receiver := the {embedder_object} from above
+ *   param := 42
+ *
+ * Currently only void return types are supported.
+ * Currently supported argument types:
+ *  - pointer to an embedder type
+ *  - bool
+ *  - int32_t
+ *  - uint32_t
+ * To be supported types:
+ *  - int64_t
+ *  - uint64_t
+ *  - float32_t
+ *  - float64_t
+ *  - arrays of C types
+ *  - arrays of embedder types
+ */
+
+#ifndef INCLUDE_V8_FAST_API_CALLS_H_
+#define INCLUDE_V8_FAST_API_CALLS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "v8config.h"  // NOLINT(build/include)
+
+namespace v8 {
+
+class CTypeInfo {
+ public:
+  enum class Type : char {
+    kVoid,
+    kBool,
+    kInt32,
+    kUint32,
+    kInt64,
+    kUint64,
+    kFloat32,
+    kFloat64,
+    kUnwrappedApiObject,
+  };
+
+  enum ArgFlags : char {
+    None = 0,
+    IsArrayBit = 1 << 0,  // This argument is first in an array of values.
+  };
+
+  static CTypeInfo FromWrapperType(const void* wrapper_type_info,
+                                   ArgFlags flags = ArgFlags::None) {
+    uintptr_t wrapper_type_info_ptr =
+        reinterpret_cast<uintptr_t>(wrapper_type_info);
+    // Check that the lower kIsWrapperTypeBit bits are 0's.
+    CHECK_EQ(
+        wrapper_type_info_ptr & ~(static_cast<uintptr_t>(~0)
+                                  << static_cast<uintptr_t>(kIsWrapperTypeBit)),
+        0);
+    // TODO(mslekova): Refactor the manual bit manipulations to use
+    // PointerWithPayload instead.
+    return CTypeInfo(wrapper_type_info_ptr | flags | kIsWrapperTypeBit);
+  }
+
+  static constexpr CTypeInfo FromCType(Type ctype,
+                                       ArgFlags flags = ArgFlags::None) {
+    // ctype cannot be Type::kUnwrappedApiObject.
+    return CTypeInfo(
+        ((static_cast<uintptr_t>(ctype) << kTypeOffset) & kTypeMask) | flags);
+  }
+
+  const void* GetWrapperInfo() const;
+
+  constexpr Type GetType() const {
+    if (payload_ & kIsWrapperTypeBit) {
+      return Type::kUnwrappedApiObject;
+    }
+    return static_cast<Type>((payload_ & kTypeMask) >> kTypeOffset);
+  }
+
+  constexpr bool IsArray() const { return payload_ & ArgFlags::IsArrayBit; }
+
+ private:
+  explicit constexpr CTypeInfo(uintptr_t payload) : payload_(payload) {}
+
+  // That must be the last bit after ArgFlags.
+  static constexpr uintptr_t kIsWrapperTypeBit = 1 << 1;
+  static constexpr uintptr_t kWrapperTypeInfoMask = static_cast<uintptr_t>(~0)
+                                                    << 2;
+
+  static constexpr unsigned int kTypeOffset = kIsWrapperTypeBit;
+  static constexpr unsigned int kTypeSize = 8 - kTypeOffset;
+  static constexpr uintptr_t kTypeMask =
+      (~(static_cast<uintptr_t>(~0) << kTypeSize)) << kTypeOffset;
+
+  const uintptr_t payload_;
+};
+
+class CFunctionInfo {
+ public:
+  virtual const CTypeInfo& ReturnInfo() const = 0;
+  virtual unsigned int ArgumentCount() const = 0;
+  virtual const CTypeInfo& ArgumentInfo(unsigned int index) const = 0;
+};
+
+template <typename T>
+class WrapperTraits {
+ public:
+  static const void* GetTypeInfo() {
+    static_assert(sizeof(T) != sizeof(T),
+                  "WrapperTraits must be specialized for this type.");
+    return nullptr;
+  }
+};
+
+namespace internal {
+
+template <typename T>
+struct GetCType {
+  static_assert(sizeof(T) != sizeof(T), "Unsupported CType");
+};
+
+#define SPECIALIZE_GET_C_TYPE_FOR(ctype, ctypeinfo)            \
+  template <>                                                  \
+  struct GetCType<ctype> {                                     \
+    static constexpr CTypeInfo Get() {                         \
+      return CTypeInfo::FromCType(CTypeInfo::Type::ctypeinfo); \
+    }                                                          \
+  };
+
+#define SUPPORTED_C_TYPES(V) \
+  V(void, kVoid)             \
+  V(bool, kBool)             \
+  V(int32_t, kInt32)         \
+  V(uint32_t, kUint32)       \
+  V(int64_t, kInt64)         \
+  V(uint64_t, kUint64)       \
+  V(float, kFloat32)         \
+  V(double, kFloat64)
+
+SUPPORTED_C_TYPES(SPECIALIZE_GET_C_TYPE_FOR)
+
+template <typename T, typename = void>
+struct EnableIfHasWrapperTypeInfo {};
+
+template <>
+struct EnableIfHasWrapperTypeInfo<void> {};
+
+template <typename T>
+struct EnableIfHasWrapperTypeInfo<T, decltype(WrapperTraits<T>::GetTypeInfo(),
+                                              void())> {
+  typedef void type;
+};
+
+// T* where T is a primitive (array of primitives).
+template <typename T, typename = void>
+struct GetCTypePointerImpl {
+  static constexpr CTypeInfo Get() {
+    return CTypeInfo::FromCType(GetCType<T>::Get().GetType(),
+                                CTypeInfo::IsArrayBit);
+  }
+};
+
+// T* where T is an API object.
+template <typename T>
+struct GetCTypePointerImpl<T, typename EnableIfHasWrapperTypeInfo<T>::type> {
+  static constexpr CTypeInfo Get() {
+    return CTypeInfo::FromWrapperType(WrapperTraits<T>::GetTypeInfo());
+  }
+};
+
+// T** where T is a primitive. Not allowed.
+template <typename T, typename = void>
+struct GetCTypePointerPointerImpl {
+  static_assert(sizeof(T**) != sizeof(T**), "Unsupported type");
+};
+
+// T** where T is an API object (array of API objects).
+template <typename T>
+struct GetCTypePointerPointerImpl<
+    T, typename EnableIfHasWrapperTypeInfo<T>::type> {
+  static constexpr CTypeInfo Get() {
+    return CTypeInfo::FromWrapperType(WrapperTraits<T>::GetTypeInfo(),
+                                      CTypeInfo::IsArrayBit);
+  }
+};
+
+template <typename T>
+struct GetCType<T**> : public GetCTypePointerPointerImpl<T> {};
+
+template <typename T>
+struct GetCType<T*> : public GetCTypePointerImpl<T> {};
+
+template <typename R, typename... Args>
+class CFunctionInfoImpl : public CFunctionInfo {
+ public:
+  CFunctionInfoImpl()
+      : return_info_(i::GetCType<R>::Get()),
+        arg_count_(sizeof...(Args)),
+        arg_info_{i::GetCType<Args>::Get()...} {
+    static_assert(i::GetCType<R>::Get().GetType() == CTypeInfo::Type::kVoid,
+                  "Only void return types are currently supported.");
+  }
+
+  const CTypeInfo& ReturnInfo() const override { return return_info_; }
+  unsigned int ArgumentCount() const override { return arg_count_; }
+  const CTypeInfo& ArgumentInfo(unsigned int index) const override {
+    CHECK_LT(index, ArgumentCount());
+    return arg_info_[index];
+  }
+
+ private:
+  CTypeInfo return_info_;
+  const unsigned int arg_count_;
+  CTypeInfo arg_info_[sizeof...(Args)];
+};
+
+}  // namespace internal
+
+class V8_EXPORT CFunction {
+ public:
+  const CTypeInfo& ReturnInfo() const { return type_info_->ReturnInfo(); }
+
+  const CTypeInfo& ArgumentInfo(unsigned int index) const {
+    return type_info_->ArgumentInfo(index);
+  }
+
+  unsigned int ArgumentCount() const { return type_info_->ArgumentCount(); }
+
+  const void* GetAddress() const { return address_; }
+  const CFunctionInfo* GetTypeInfo() const { return type_info_; }
+
+  template <typename F>
+  static CFunction Make(F* func) {
+    return ArgUnwrap<F*>::Make(func);
+  }
+
+ private:
+  const void* address_;
+  const CFunctionInfo* type_info_;
+
+  CFunction(const void* address, const CFunctionInfo* type_info);
+
+  template <typename R, typename... Args>
+  static CFunctionInfo* GetCFunctionInfo() {
+    static internal::CFunctionInfoImpl<R, Args...> instance;
+    return &instance;
+  }
+
+  template <typename F>
+  class ArgUnwrap {
+    static_assert(sizeof(F) != sizeof(F),
+                  "CFunction must be created from a function pointer.");
+  };
+
+  template <typename R, typename... Args>
+  class ArgUnwrap<R (*)(Args...)> {
+   public:
+    static CFunction Make(R (*func)(Args...)) {
+      return CFunction(reinterpret_cast<const void*>(func),
+                       GetCFunctionInfo<R, Args...>());
+    }
+  };
+};
+
+}  // namespace v8
+
+#endif  // INCLUDE_V8_FAST_API_CALLS_H_
diff --git a/deps/v8/include/v8-inspector.h b/deps/v8/include/v8-inspector.h
index b9a4866533..01274625c1 100644
--- a/deps/v8/include/v8-inspector.h
+++ b/deps/v8/include/v8-inspector.h
@@ -65,15 +65,15 @@ class V8_EXPORT StringView {
 class V8_EXPORT StringBuffer {
  public:
   virtual ~StringBuffer() = default;
-  virtual const StringView& string() = 0;
+  virtual StringView string() const = 0;
   // This method copies contents.
-  static std::unique_ptr<StringBuffer> create(const StringView&);
+  static std::unique_ptr<StringBuffer> create(StringView);
 };
 
 class V8_EXPORT V8ContextInfo {
  public:
   V8ContextInfo(v8::Local<v8::Context> context, int contextGroupId,
-                const StringView& humanReadableName)
+                StringView humanReadableName)
       : context(context),
         contextGroupId(contextGroupId),
         humanReadableName(humanReadableName),
@@ -132,37 +132,36 @@ class V8_EXPORT V8InspectorSession {
   virtual void addInspectedObject(std::unique_ptr<Inspectable>) = 0;
 
   // Dispatching protocol messages.
-  static bool canDispatchMethod(const StringView& method);
-  virtual void dispatchProtocolMessage(const StringView& message) = 0;
+  static bool canDispatchMethod(StringView method);
+  virtual void dispatchProtocolMessage(StringView message) = 0;
   virtual std::vector<uint8_t> state() = 0;
   virtual std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
   supportedDomains() = 0;
 
   // Debugger actions.
-  virtual void schedulePauseOnNextStatement(const StringView& breakReason,
-                                            const StringView& breakDetails) = 0;
+  virtual void schedulePauseOnNextStatement(StringView breakReason,
+                                            StringView breakDetails) = 0;
   virtual void cancelPauseOnNextStatement() = 0;
-  virtual void breakProgram(const StringView& breakReason,
-                            const StringView& breakDetails) = 0;
+  virtual void breakProgram(StringView breakReason,
+                            StringView breakDetails) = 0;
   virtual void setSkipAllPauses(bool) = 0;
-  virtual void resume() = 0;
+  virtual void resume(bool setTerminateOnResume = false) = 0;
   virtual void stepOver() = 0;
   virtual std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
-  searchInTextByLines(const StringView& text, const StringView& query,
-                      bool caseSensitive, bool isRegex) = 0;
+  searchInTextByLines(StringView text, StringView query, bool caseSensitive,
+                      bool isRegex) = 0;
 
   // Remote objects.
   virtual std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
-      v8::Local<v8::Context>, v8::Local<v8::Value>, const StringView& groupName,
+      v8::Local<v8::Context>, v8::Local<v8::Value>, StringView groupName,
       bool generatePreview) = 0;
 
   virtual bool unwrapObject(std::unique_ptr<StringBuffer>* error,
-                            const StringView& objectId, v8::Local<v8::Value>*,
+                            StringView objectId, v8::Local<v8::Value>*,
                             v8::Local<v8::Context>*,
                             std::unique_ptr<StringBuffer>* objectGroup) = 0;
-  virtual void releaseObjectGroup(const StringView&) = 0;
-  virtual void triggerPreciseCoverageDeltaUpdate(
-      const StringView& occassion) = 0;
+  virtual void releaseObjectGroup(StringView) = 0;
+  virtual void triggerPreciseCoverageDeltaUpdate(StringView occassion) = 0;
 };
 
 class V8_EXPORT V8InspectorClient {
@@ -240,7 +239,7 @@ struct V8_EXPORT V8StackTraceId {
   V8StackTraceId(uintptr_t id, const std::pair<int64_t, int64_t> debugger_id);
   V8StackTraceId(uintptr_t id, const std::pair<int64_t, int64_t> debugger_id,
                  bool should_pause);
-  explicit V8StackTraceId(const StringView&);
+  explicit V8StackTraceId(StringView);
   V8StackTraceId& operator=(const V8StackTraceId&) = default;
   V8StackTraceId& operator=(V8StackTraceId&&) noexcept = default;
   ~V8StackTraceId() = default;
@@ -265,26 +264,26 @@ class V8_EXPORT V8Inspector {
   virtual void idleFinished() = 0;
 
   // Async stack traces instrumentation.
-  virtual void asyncTaskScheduled(const StringView& taskName, void* task,
+  virtual void asyncTaskScheduled(StringView taskName, void* task,
                                   bool recurring) = 0;
   virtual void asyncTaskCanceled(void* task) = 0;
   virtual void asyncTaskStarted(void* task) = 0;
   virtual void asyncTaskFinished(void* task) = 0;
   virtual void allAsyncTasksCanceled() = 0;
 
-  virtual V8StackTraceId storeCurrentStackTrace(
-      const StringView& description) = 0;
+  virtual V8StackTraceId storeCurrentStackTrace(StringView description) = 0;
   virtual void externalAsyncTaskStarted(const V8StackTraceId& parent) = 0;
   virtual void externalAsyncTaskFinished(const V8StackTraceId& parent) = 0;
 
   // Exceptions instrumentation.
-  virtual unsigned exceptionThrown(
-      v8::Local<v8::Context>, const StringView& message,
-      v8::Local<v8::Value> exception, const StringView& detailedMessage,
-      const StringView& url, unsigned lineNumber, unsigned columnNumber,
-      std::unique_ptr<V8StackTrace>, int scriptId) = 0;
+  virtual unsigned exceptionThrown(v8::Local<v8::Context>, StringView message,
+                                   v8::Local<v8::Value> exception,
+                                   StringView detailedMessage, StringView url,
+                                   unsigned lineNumber, unsigned columnNumber,
+                                   std::unique_ptr<V8StackTrace>,
+                                   int scriptId) = 0;
   virtual void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
-                                const StringView& message) = 0;
+                                StringView message) = 0;
 
   // Connection.
   class V8_EXPORT Channel {
@@ -295,8 +294,9 @@ class V8_EXPORT V8Inspector {
     virtual void sendNotification(std::unique_ptr<StringBuffer> message) = 0;
     virtual void flushProtocolNotifications() = 0;
   };
-  virtual std::unique_ptr<V8InspectorSession> connect(
-      int contextGroupId, Channel*, const StringView& state) = 0;
+  virtual std::unique_ptr<V8InspectorSession> connect(int contextGroupId,
+                                                      Channel*,
+                                                      StringView state) = 0;
 
   // API methods.
   virtual std::unique_ptr<V8StackTrace> createStackTrace(
diff --git a/deps/v8/include/v8-internal.h b/deps/v8/include/v8-internal.h
index e4d698e6ce..876408ebba 100644
--- a/deps/v8/include/v8-internal.h
+++ b/deps/v8/include/v8-internal.h
@@ -160,10 +160,10 @@ class Internals {
       kNumIsolateDataSlots * kApiSystemPointerSize;
   static const int kExternalMemoryLimitOffset =
       kExternalMemoryOffset + kApiInt64Size;
-  static const int kExternalMemoryAtLastMarkCompactOffset =
+  static const int kExternalMemoryLowSinceMarkCompactOffset =
       kExternalMemoryLimitOffset + kApiInt64Size;
   static const int kIsolateFastCCallCallerFpOffset =
-      kExternalMemoryAtLastMarkCompactOffset + kApiInt64Size;
+      kExternalMemoryLowSinceMarkCompactOffset + kApiInt64Size;
   static const int kIsolateFastCCallCallerPcOffset =
       kIsolateFastCCallCallerFpOffset + kApiSystemPointerSize;
   static const int kIsolateStackGuardOffset =
diff --git a/deps/v8/include/v8-version.h b/deps/v8/include/v8-version.h
index f21a0b8dd0..64f1848665 100644
--- a/deps/v8/include/v8-version.h
+++ b/deps/v8/include/v8-version.h
@@ -9,9 +9,9 @@
 // NOTE these macros are used by some of the tool scripts and the build
 // system so their names cannot be changed without changing the scripts.
 #define V8_MAJOR_VERSION 8
-#define V8_MINOR_VERSION 1
-#define V8_BUILD_NUMBER 307
-#define V8_PATCH_LEVEL 31
+#define V8_MINOR_VERSION 3
+#define V8_BUILD_NUMBER 110
+#define V8_PATCH_LEVEL 9
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
diff --git a/deps/v8/include/v8.h b/deps/v8/include/v8.h
index 54bc4f0835..9926b308b1 100644
--- a/deps/v8/include/v8.h
+++ b/deps/v8/include/v8.h
@@ -120,6 +120,8 @@ class EscapableHandleScope;
 template<typename T> class ReturnValue;
 
 namespace internal {
+enum class ArgumentsType;
+template <ArgumentsType>
 class Arguments;
 class DeferredHandles;
 class Heap;
@@ -149,11 +151,6 @@ class ConsoleCallArguments;
 
 // --- Handles ---
 
-#define TYPE_CHECK(T, S)                                       \
-  while (false) {                                              \
-    *(static_cast<T* volatile*>(0)) = static_cast<S*>(0);      \
-  }
-
 /**
  * An object reference managed by the v8 garbage collector.
  *
@@ -197,7 +194,7 @@ class Local {
      * handles. For example, converting from a Local<String> to a
      * Local<Number>.
      */
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   /**
@@ -363,7 +360,7 @@ class MaybeLocal {
   template <class S>
   V8_INLINE MaybeLocal(Local<S> that)
       : val_(reinterpret_cast<T*>(*that)) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   V8_INLINE bool IsEmpty() const { return val_ == nullptr; }
@@ -532,11 +529,16 @@ template <class T> class PersistentBase {
   }
 
   /**
-   *  Install a finalization callback on this object.
-   *  NOTE: There is no guarantee as to *when* or even *if* the callback is
-   *  invoked. The invocation is performed solely on a best effort basis.
-   *  As always, GC-based finalization should *not* be relied upon for any
-   *  critical form of resource management!
+   * Install a finalization callback on this object.
+   * NOTE: There is no guarantee as to *when* or even *if* the callback is
+   * invoked. The invocation is performed solely on a best effort basis.
+   * As always, GC-based finalization should *not* be relied upon for any
+   * critical form of resource management!
+   *
+   * The callback is supposed to reset the handle. No further V8 API may be
+   * called in this callback. In case additional work involving V8 needs to be
+   * done, a second callback can be scheduled using
+   * WeakCallbackInfo<void>::SetSecondPassCallback.
    */
   template <typename P>
   V8_INLINE void SetWeak(P* parameter,
@@ -618,11 +620,8 @@ class NonCopyablePersistentTraits {
   template<class S, class M>
   V8_INLINE static void Copy(const Persistent<S, M>& source,
                              NonCopyablePersistent* dest) {
-    Uncompilable<Object>();
-  }
-  // TODO(dcarney): come up with a good compile error here.
-  template<class O> V8_INLINE static void Uncompilable() {
-    TYPE_CHECK(O, Primitive);
+    static_assert(sizeof(S) < 0,
+                  "NonCopyablePersistentTraits::Copy is not instantiable");
   }
 };
 
@@ -665,7 +664,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
   template <class S>
   V8_INLINE Persistent(Isolate* isolate, Local<S> that)
       : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
   /**
    * Construct a Persistent from a Persistent.
@@ -675,7 +674,7 @@ template <class T, class M> class Persistent : public PersistentBase<T> {
   template <class S, class M2>
   V8_INLINE Persistent(Isolate* isolate, const Persistent<S, M2>& that)
     : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
   /**
    * The copy constructors and assignment operator create a Persistent
@@ -760,7 +759,7 @@ class Global : public PersistentBase<T> {
   template <class S>
   V8_INLINE Global(Isolate* isolate, Local<S> that)
       : PersistentBase<T>(PersistentBase<T>::New(isolate, *that)) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   /**
@@ -771,7 +770,7 @@ class Global : public PersistentBase<T> {
   template <class S>
   V8_INLINE Global(Isolate* isolate, const PersistentBase<S>& that)
       : PersistentBase<T>(PersistentBase<T>::New(isolate, that.val_)) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   /**
@@ -951,7 +950,7 @@ class TracedGlobal : public TracedReferenceBase<T> {
   TracedGlobal(Isolate* isolate, Local<S> that) : TracedReferenceBase<T>() {
     this->val_ = this->New(isolate, that.val_, &this->val_,
                            TracedReferenceBase<T>::kWithDestructor);
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   /**
@@ -1074,7 +1073,7 @@ class TracedReference : public TracedReferenceBase<T> {
   TracedReference(Isolate* isolate, Local<S> that) : TracedReferenceBase<T>() {
     this->val_ = this->New(isolate, that.val_, &this->val_,
                            TracedReferenceBase<T>::kWithoutDestructor);
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
 
   /**
@@ -1128,17 +1127,11 @@ class TracedReference : public TracedReferenceBase<T> {
 
   /**
    * Copy assignment operator initializing TracedGlobal from an existing one.
-   *
-   * Note: Prohibited when |other| has a finalization callback set through
-   * |SetFinalizationCallback|.
    */
   V8_INLINE TracedReference& operator=(const TracedReference& rhs);
 
   /**
    * Copy assignment operator initializing TracedGlobal from an existing one.
-   *
-   * Note: Prohibited when |other| has a finalization callback set through
-   * |SetFinalizationCallback|.
    */
   template <class S>
   V8_INLINE TracedReference& operator=(const TracedReference<S>& rhs);
@@ -1155,20 +1148,6 @@ class TracedReference : public TracedReferenceBase<T> {
     return reinterpret_cast<TracedReference<S>&>(
         const_cast<TracedReference<T>&>(*this));
   }
-
-  /**
-   * Adds a finalization callback to the handle. The type of this callback is
-   * similar to WeakCallbackType::kInternalFields, i.e., it will pass the
-   * parameter and the first two internal fields of the object.
-   *
-   * The callback is then supposed to reset the handle in the callback. No
-   * further V8 API may be called in this callback. In case additional work
-   * involving V8 needs to be done, a second callback can be scheduled using
-   * WeakCallbackInfo<void>::SetSecondPassCallback.
-   */
-  V8_DEPRECATED("Use TracedGlobal<> if callbacks are required.")
-  V8_INLINE void SetFinalizationCallback(
-      void* parameter, WeakCallbackInfo<void>::Callback callback);
 };
 
  /**
@@ -1773,11 +1752,9 @@ class V8_EXPORT ScriptCompiler {
    public:
     enum Encoding { ONE_BYTE, TWO_BYTE, UTF8 };
 
-#if defined(_MSC_VER) && _MSC_VER >= 1910 /* Disable on VS2015 */
     V8_DEPRECATE_SOON(
         "This class takes ownership of source_stream, so use the constructor "
         "taking a unique_ptr to make these semantics clearer")
-#endif
     StreamedSource(ExternalSourceStream* source_stream, Encoding encoding);
     StreamedSource(std::unique_ptr<ExternalSourceStream> source_stream,
                    Encoding encoding);
@@ -2201,6 +2178,7 @@ enum StateTag {
   COMPILER,
   OTHER,
   EXTERNAL,
+  ATOMICS_WAIT,
   IDLE
 };
 
@@ -2467,14 +2445,6 @@ class V8_EXPORT ValueDeserializer {
   void SetSupportsLegacyWireFormat(bool supports_legacy_wire_format);
 
   /**
-   * Expect inline wasm in the data stream (rather than in-memory transfer)
-   */
-  V8_DEPRECATED(
-      "Wasm module serialization is only supported via explicit methods, e.g. "
-      "CompiledWasmModule::Serialize()")
-  void SetExpectInlineWasm(bool allow_inline_wasm) {}
-
-  /**
    * Reads the underlying wire format version. Likely mostly to be useful to
    * legacy code reading old wire format versions. Must be called after
    * ReadHeader.
@@ -2813,9 +2783,6 @@ class V8_EXPORT Value : public Data {
    */
   bool IsWasmModuleObject() const;
 
-  V8_DEPRECATED("Use IsWasmModuleObject")
-  bool IsWebAssemblyCompiledModule() const;
-
   /**
    * Returns true if the value is a Module Namespace Object.
    */
@@ -3206,6 +3173,23 @@ class V8_EXPORT String : public Name {
 
   V8_INLINE static String* Cast(v8::Value* obj);
 
+  /**
+   * Allocates a new string from a UTF-8 literal. This is equivalent to calling
+   * String::NewFromUtf(isolate, "...").ToLocalChecked(), but without the check
+   * overhead.
+   *
+   * When called on a string literal containing '\0', the inferred length is the
+   * length of the input array minus 1 (for the final '\0') and not the value
+   * returned by strlen.
+   **/
+  template <int N>
+  static V8_WARN_UNUSED_RESULT Local<String> NewFromUtf8Literal(
+      Isolate* isolate, const char (&literal)[N],
+      NewStringType type = NewStringType::kNormal) {
+    static_assert(N <= kMaxLength, "String is too long");
+    return NewFromUtf8Literal(isolate, literal, type, N - 1);
+  }
+
   /** Allocates a new string from UTF-8 data. Only returns an empty value when
    * length > kMaxLength. **/
   static V8_WARN_UNUSED_RESULT MaybeLocal<String> NewFromUtf8(
@@ -3340,9 +3324,20 @@ class V8_EXPORT String : public Name {
   ExternalStringResourceBase* GetExternalStringResourceBaseSlow(
       String::Encoding* encoding_out) const;
 
+  static Local<v8::String> NewFromUtf8Literal(Isolate* isolate,
+                                              const char* literal,
+                                              NewStringType type, int length);
+
   static void CheckCast(v8::Value* obj);
 };
 
+// Zero-length string specialization (templated string size includes
+// terminator).
+template <>
+inline V8_WARN_UNUSED_RESULT Local<String> String::NewFromUtf8Literal(
+    Isolate* isolate, const char (&literal)[1], NewStringType type) {
+  return String::Empty(isolate);
+}
 
 /**
  * A JavaScript symbol (ECMA-262 edition 6)
@@ -4050,6 +4045,13 @@ class V8_EXPORT Object : public Value {
   bool IsApiWrapper();
 
   /**
+   * True if this object was created from an object template which was marked
+   * as undetectable. See v8::ObjectTemplate::MarkAsUndetectable for more
+   * information.
+   */
+  bool IsUndetectable();
+
+  /**
    * Call an Object as a function if a callback is set by the
    * ObjectTemplate::SetCallAsFunctionHandler method.
    */
@@ -4205,7 +4207,7 @@ class ReturnValue {
  public:
   template <class S> V8_INLINE ReturnValue(const ReturnValue<S>& that)
       : value_(that.value_) {
-    TYPE_CHECK(T, S);
+    static_assert(std::is_base_of<T, S>::value, "type check");
   }
   // Local setters
   template <typename S>
@@ -4785,27 +4787,9 @@ class V8_EXPORT WasmModuleObject : public Object {
    */
   CompiledWasmModule GetCompiledModule();
 
-  /**
-   * If possible, deserialize the module, otherwise compile it from the provided
-   * uncompiled bytes.
-   */
-  V8_DEPRECATED(
-      "Use WasmStreaming for deserialization from cache or the "
-      "CompiledWasmModule to transfer between isolates")
-  static MaybeLocal<WasmModuleObject> DeserializeOrCompile(
-      Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
-      MemorySpan<const uint8_t> wire_bytes);
-
   V8_INLINE static WasmModuleObject* Cast(Value* obj);
 
  private:
-  static MaybeLocal<WasmModuleObject> Deserialize(
-      Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
-      MemorySpan<const uint8_t> wire_bytes);
-  static MaybeLocal<WasmModuleObject> Compile(Isolate* isolate,
-                                              const uint8_t* start,
-                                              size_t length);
-
   static void CheckCast(Value* obj);
 };
 
@@ -4978,6 +4962,34 @@ class V8_EXPORT BackingStore : public v8::internal::BackingStoreBase {
    */
   bool IsShared() const;
 
+  /**
+   * Wrapper around ArrayBuffer::Allocator::Reallocate that preserves IsShared.
+   * Assumes that the backing_store was allocated by the ArrayBuffer allocator
+   * of the given isolate.
+   */
+  static std::unique_ptr<BackingStore> Reallocate(
+      v8::Isolate* isolate, std::unique_ptr<BackingStore> backing_store,
+      size_t byte_length);
+
+  /**
+   * This callback is used only if the memory block for a BackingStore cannot be
+   * allocated with an ArrayBuffer::Allocator. In such cases the destructor of
+   * the BackingStore invokes the callback to free the memory block.
+   */
+  using DeleterCallback = void (*)(void* data, size_t length,
+                                   void* deleter_data);
+
+  /**
+   * If the memory block of a BackingStore is static or is managed manually,
+   * then this empty deleter along with nullptr deleter_data can be passed to
+   * ArrayBuffer::NewBackingStore to indicate that.
+   *
+   * The manually managed case should be used with caution and only when it
+   * is guaranteed that the memory block freeing happens after detaching its
+   * ArrayBuffer.
+   */
+  static void EmptyDeleter(void* data, size_t length, void* deleter_data);
+
  private:
   /**
    * See [Shared]ArrayBuffer::GetBackingStore and
@@ -4986,14 +4998,13 @@ class V8_EXPORT BackingStore : public v8::internal::BackingStoreBase {
   BackingStore();
 };
 
-/**
- * This callback is used only if the memory block for this backing store cannot
- * be allocated with an ArrayBuffer::Allocator. In such cases the destructor
- * of this backing store object invokes the callback to free the memory block.
- */
+#if !defined(V8_IMMINENT_DEPRECATION_WARNINGS)
+// Use v8::BackingStore::DeleterCallback instead.
 using BackingStoreDeleterCallback = void (*)(void* data, size_t length,
                                              void* deleter_data);
 
+#endif
+
 /**
  * An instance of the built-in ArrayBuffer constructor (ES6 draft 15.13.5).
  */
@@ -5019,13 +5030,13 @@ class V8_EXPORT ArrayBuffer : public Object {
     virtual ~Allocator() = default;
 
     /**
-     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Allocate |length| bytes. Return nullptr if allocation is not successful.
      * Memory should be initialized to zeroes.
      */
     virtual void* Allocate(size_t length) = 0;
 
     /**
-     * Allocate |length| bytes. Return NULL if allocation is not successful.
+     * Allocate |length| bytes. Return nullptr if allocation is not successful.
      * Memory does not have to be initialized.
      */
     virtual void* AllocateUninitialized(size_t length) = 0;
@@ -5037,6 +5048,20 @@ class V8_EXPORT ArrayBuffer : public Object {
     virtual void Free(void* data, size_t length) = 0;
 
     /**
+     * Reallocate the memory block of size |old_length| to a memory block of
+     * size |new_length| by expanding, contracting, or copying the existing
+     * memory block. If |new_length| > |old_length|, then the new part of
+     * the memory must be initialized to zeros. Return nullptr if reallocation
+     * is not successful.
+     *
+     * The caller guarantees that the memory block was previously allocated
+     * using Allocate or AllocateUninitialized.
+     *
+     * The default implementation allocates a new block and copies data.
+     */
+    virtual void* Reallocate(void* data, size_t old_length, size_t new_length);
+
+    /**
      * ArrayBuffer allocation mode. kNormal is a malloc/free style allocation,
      * while kReservation is for larger allocations with the ability to set
      * access permissions.
@@ -5167,7 +5192,7 @@ class V8_EXPORT ArrayBuffer : public Object {
    * to the buffer must not be passed again to any V8 API function.
    */
   static std::unique_ptr<BackingStore> NewBackingStore(
-      void* data, size_t byte_length, BackingStoreDeleterCallback deleter,
+      void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
       void* deleter_data);
 
   /**
@@ -5649,7 +5674,7 @@ class V8_EXPORT SharedArrayBuffer : public Object {
    * to the buffer must not be passed again to any V8 functions.
    */
   static std::unique_ptr<BackingStore> NewBackingStore(
-      void* data, size_t byte_length, BackingStoreDeleterCallback deleter,
+      void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
       void* deleter_data);
 
   /**
@@ -5909,14 +5934,15 @@ class V8_EXPORT RegExp : public Object {
 };
 
 /**
- * An instance of the built-in FinalizationGroup constructor.
+ * An instance of the built-in FinalizationRegistry constructor.
  *
- * This API is experimental and may change significantly.
+ * The C++ name is FinalizationGroup for backwards compatibility. This API is
+ * experimental and deprecated.
  */
 class V8_EXPORT FinalizationGroup : public Object {
  public:
   /**
-   * Runs the cleanup callback of the given FinalizationGroup.
+   * Runs the cleanup callback of the given FinalizationRegistry.
    *
    * V8 will inform the embedder that there are finalizer callbacks be
    * called through HostCleanupFinalizationGroupCallback.
@@ -5931,6 +5957,9 @@ class V8_EXPORT FinalizationGroup : public Object {
    * occurred. Otherwise the result is |true| if the cleanup callback
    * was called successfully. The result is never |false|.
    */
+  V8_DEPRECATED(
+      "FinalizationGroup cleanup is automatic if "
+      "HostCleanupFinalizationGroupCallback is not set")
   static V8_WARN_UNUSED_RESULT Maybe<bool> Cleanup(
       Local<FinalizationGroup> finalization_group);
 };
@@ -5948,13 +5977,14 @@ class V8_EXPORT External : public Value {
   static void CheckCast(v8::Value* obj);
 };
 
-#define V8_INTRINSICS_LIST(F)                    \
-  F(ArrayProto_entries, array_entries_iterator)  \
-  F(ArrayProto_forEach, array_for_each_iterator) \
-  F(ArrayProto_keys, array_keys_iterator)        \
-  F(ArrayProto_values, array_values_iterator)    \
-  F(ErrorPrototype, initial_error_prototype)     \
-  F(IteratorPrototype, initial_iterator_prototype)
+#define V8_INTRINSICS_LIST(F)                      \
+  F(ArrayProto_entries, array_entries_iterator)    \
+  F(ArrayProto_forEach, array_for_each_iterator)   \
+  F(ArrayProto_keys, array_keys_iterator)          \
+  F(ArrayProto_values, array_values_iterator)      \
+  F(ErrorPrototype, initial_error_prototype)       \
+  F(IteratorPrototype, initial_iterator_prototype) \
+  F(ObjProto_valueOf, object_value_of_function)
 
 enum Intrinsic {
 #define V8_DECL_INTRINSIC(name, iname) k##name,
@@ -6300,6 +6330,7 @@ typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
                                     Local<Object> accessed_object,
                                     Local<Value> data);
 
+class CFunction;
 /**
  * A FunctionTemplate is used to create functions at runtime. There
  * can only be one function created from a FunctionTemplate in a
@@ -6335,11 +6366,12 @@ typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
  *    proto_t->Set(isolate, "proto_const", v8::Number::New(isolate, 2));
  *
  *    v8::Local<v8::ObjectTemplate> instance_t = t->InstanceTemplate();
- *    instance_t->SetAccessor(String::NewFromUtf8(isolate, "instance_accessor"),
- *                            InstanceAccessorCallback);
+ *    instance_t->SetAccessor(
+          String::NewFromUtf8Literal(isolate, "instance_accessor"),
+ *        InstanceAccessorCallback);
  *    instance_t->SetHandler(
  *        NamedPropertyHandlerConfiguration(PropertyHandlerCallback));
- *    instance_t->Set(String::NewFromUtf8(isolate, "instance_property"),
+ *    instance_t->Set(String::NewFromUtf8Literal(isolate, "instance_property"),
  *                    Number::New(isolate, 3));
  *
  *    v8::Local<v8::Function> function = t->GetFunction();
@@ -6399,6 +6431,12 @@ typedef bool (*AccessCheckCallback)(Local<Context> accessing_context,
  *   child_instance.instance_accessor calls 'InstanceAccessorCallback'
  *   child_instance.instance_property == 3;
  * \endcode
+ *
+ * The additional 'c_function' parameter refers to a fast API call, which
+ * must not trigger GC or JavaScript execution, or call into V8 in other
+ * ways. For more information how to define them, see
+ * include/v8-fast-api-calls.h. Please note that this feature is still
+ * experimental.
  */
 class V8_EXPORT FunctionTemplate : public Template {
  public:
@@ -6408,7 +6446,8 @@ class V8_EXPORT FunctionTemplate : public Template {
       Local<Value> data = Local<Value>(),
       Local<Signature> signature = Local<Signature>(), int length = 0,
       ConstructorBehavior behavior = ConstructorBehavior::kAllow,
-      SideEffectType side_effect_type = SideEffectType::kHasSideEffect);
+      SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
+      const CFunction* c_function = nullptr);
 
   /** Get a template included in the snapshot by index. */
   V8_DEPRECATED("Use v8::Isolate::GetDataFromSnapshotOnce instead")
@@ -6440,11 +6479,13 @@ class V8_EXPORT FunctionTemplate : public Template {
   /**
    * Set the call-handler callback for a FunctionTemplate.  This
    * callback is called whenever the function created from this
-   * FunctionTemplate is called.
+   * FunctionTemplate is called. The 'c_function' represents a fast
+   * API call, see the comment above the class declaration.
    */
   void SetCallHandler(
       FunctionCallback callback, Local<Value> data = Local<Value>(),
-      SideEffectType side_effect_type = SideEffectType::kHasSideEffect);
+      SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
+      const CFunction* c_function = nullptr);
 
   /** Set the predefined length property for the FunctionTemplate. */
   void SetLength(int length);
@@ -7293,14 +7334,15 @@ class PromiseRejectMessage {
 typedef void (*PromiseRejectCallback)(PromiseRejectMessage message);
 
 // --- Microtasks Callbacks ---
+V8_DEPRECATE_SOON("Use *WithData version.")
 typedef void (*MicrotasksCompletedCallback)(Isolate*);
 typedef void (*MicrotasksCompletedCallbackWithData)(Isolate*, void*);
 typedef void (*MicrotaskCallback)(void* data);
 
-
 /**
  * Policy for running microtasks:
- *   - explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
+ *   - explicit: microtasks are invoked with the
+ *               Isolate::PerformMicrotaskCheckpoint() method;
  *   - scoped: microtasks invocation is controlled by MicrotasksScope objects;
  *   - auto: microtasks are invoked when the script call depth decrements
  *           to zero.
@@ -7391,7 +7433,7 @@ class V8_EXPORT MicrotaskQueue {
 };
 
 /**
- * This scope is used to control microtasks when kScopeMicrotasksInvocation
+ * This scope is used to control microtasks when MicrotasksPolicy::kScoped
  * is used on Isolate. In this mode every non-primitive call to V8 should be
  * done inside some MicrotasksScope.
  * Microtasks are executed when topmost MicrotasksScope marked as kRunMicrotasks
@@ -7480,7 +7522,7 @@ typedef void (*WasmStreamingCallback)(const FunctionCallbackInfo<Value>&);
 // --- Callback for checking if WebAssembly threads are enabled ---
 typedef bool (*WasmThreadsEnabledCallback)(Local<Context> context);
 
-// --- Callback for loading source map file for WASM profiling support
+// --- Callback for loading source map file for Wasm profiling support
 typedef Local<String> (*WasmLoadSourceMapCallback)(Isolate* isolate,
                                                    const char* name);
 
@@ -7576,6 +7618,8 @@ class V8_EXPORT HeapStatistics {
   size_t total_heap_size_executable() { return total_heap_size_executable_; }
   size_t total_physical_size() { return total_physical_size_; }
   size_t total_available_size() { return total_available_size_; }
+  size_t total_global_handles_size() { return total_global_handles_size_; }
+  size_t used_global_handles_size() { return used_global_handles_size_; }
   size_t used_heap_size() { return used_heap_size_; }
   size_t heap_size_limit() { return heap_size_limit_; }
   size_t malloced_memory() { return malloced_memory_; }
@@ -7603,6 +7647,8 @@ class V8_EXPORT HeapStatistics {
   bool does_zap_garbage_;
   size_t number_of_native_contexts_;
   size_t number_of_detached_contexts_;
+  size_t total_global_handles_size_;
+  size_t used_global_handles_size_;
 
   friend class V8;
   friend class Isolate;
@@ -8407,6 +8453,13 @@ class V8_EXPORT Isolate {
     kRegExpReplaceCalledOnSlowRegExp = 80,
     kDisplayNames = 81,
     kSharedArrayBufferConstructed = 82,
+    kArrayPrototypeHasElements = 83,
+    kObjectPrototypeHasElements = 84,
+    kNumberFormatStyleUnit = 85,
+    kDateTimeFormatRange = 86,
+    kDateTimeFormatDateTimeStyle = 87,
+    kBreakIteratorTypeWord = 88,
+    kBreakIteratorTypeLine = 89,
 
     // If you add new values here, you'll also need to update Chromium's:
     // web_feature.mojom, use_counter_callback.cc, and enums.xml. V8 changes to
@@ -8472,10 +8525,13 @@ class V8_EXPORT Isolate {
    * objects are originally built when a WeakRef is created or
    * successfully dereferenced.
    *
-   * The embedder is expected to call this when a synchronous sequence
-   * of ECMAScript execution completes. It's the embedders
-   * responsiblity to make this call at a time which does not
-   * interrupt synchronous ECMAScript code execution.
+   * This is invoked automatically after microtasks are run. See
+   * MicrotasksPolicy for when microtasks are run.
+   *
+   * This needs to be manually invoked only if the embedder is manually running
+   * microtasks via a custom MicrotaskQueue class's PerformCheckpoint. In that
+   * case, it is the embedder's responsibility to make this call at a time which
+   * does not interrupt synchronous ECMAScript code execution.
    */
   void ClearKeptObjects();
 
@@ -8493,10 +8549,13 @@ class V8_EXPORT Isolate {
       AbortOnUncaughtExceptionCallback callback);
 
   /**
-   * This specifies the callback to be called when finalization groups
+   * This specifies the callback to be called when FinalizationRegistries
    * are ready to be cleaned up and require FinalizationGroup::Cleanup()
    * to be called in a future task.
    */
+  V8_DEPRECATED(
+      "FinalizationRegistry cleanup is automatic if "
+      "HostCleanupFinalizationGroupCallback is not set")
   void SetHostCleanupFinalizationGroupCallback(
       HostCleanupFinalizationGroupCallback callback);
 
@@ -9000,10 +9059,18 @@ class V8_EXPORT Isolate {
   void SetPromiseRejectCallback(PromiseRejectCallback callback);
 
   /**
-   * Runs the default MicrotaskQueue until it gets empty.
-   * Any exceptions thrown by microtask callbacks are swallowed.
+   * An alias for PerformMicrotaskCheckpoint.
+   */
+  V8_DEPRECATE_SOON("Use PerformMicrotaskCheckpoint.")
+  void RunMicrotasks() { PerformMicrotaskCheckpoint(); }
+
+  /**
+   * Runs the default MicrotaskQueue until it gets empty and perform other
+   * microtask checkpoint steps, such as calling ClearKeptObjects. Asserts that
+   * the MicrotasksPolicy is not kScoped. Any exceptions thrown by microtask
+   * callbacks are swallowed.
    */
-  void RunMicrotasks();
+  void PerformMicrotaskCheckpoint();
 
   /**
    * Enqueues the callback to the default MicrotaskQueue
@@ -9101,10 +9168,10 @@ class V8_EXPORT Isolate {
   void LowMemoryNotification();
 
   /**
-   * Optional notification that a context has been disposed. V8 uses
-   * these notifications to guide the GC heuristic. Returns the number
-   * of context disposals - including this one - since the last time
-   * V8 had a chance to clean up.
+   * Optional notification that a context has been disposed. V8 uses these
+   * notifications to guide the GC heuristic and cancel FinalizationRegistry
+   * cleanup tasks. Returns the number of context disposals - including this one
+   * - since the last time V8 had a chance to clean up.
    *
    * The optional parameter |dependant_context| specifies whether the disposed
    * context was depending on state from other contexts or not.
@@ -9218,7 +9285,7 @@ class V8_EXPORT Isolate {
    * Returns the UnwindState necessary for use with the Unwinder API.
    */
   // TODO(petermarshall): Remove this API.
-  V8_DEPRECATE_SOON("Use entry_stubs + code_pages version.")
+  V8_DEPRECATED("Use entry_stubs + code_pages version.")
   UnwindState GetUnwindState();
 
   /**
@@ -10347,6 +10414,18 @@ class V8_EXPORT Context {
   void SetAbortScriptExecution(AbortScriptExecutionCallback callback);
 
   /**
+   * Returns the value that was set or restored by
+   * SetContinuationPreservedEmbedderData(), if any.
+   */
+  Local<Value> GetContinuationPreservedEmbedderData() const;
+
+  /**
+   * Sets a value that will be stored on continuations and reset while the
+   * continuation runs.
+   */
+  void SetContinuationPreservedEmbedderData(Local<Value> context);
+
+  /**
    * Stack-allocated class which sets the execution context for all
    * operations executed within a local scope.
    */
@@ -10563,7 +10642,7 @@ class V8_EXPORT Unwinder {
    * \return True on success.
    */
   // TODO(petermarshall): Remove this API
-  V8_DEPRECATE_SOON("Use entry_stubs + code_pages version.")
+  V8_DEPRECATED("Use entry_stubs + code_pages version.")
   static bool TryUnwindV8Frames(const UnwindState& unwind_state,
                                 RegisterState* register_state,
                                 const void* stack_base);
@@ -10591,7 +10670,7 @@ class V8_EXPORT Unwinder {
    * (but not necessarily) be successful.
    */
   // TODO(petermarshall): Remove this API
-  V8_DEPRECATE_SOON("Use code_pages version.")
+  V8_DEPRECATED("Use code_pages version.")
   static bool PCIsInV8(const UnwindState& unwind_state, void* pc);
 
   /**
@@ -10632,7 +10711,7 @@ Local<T> Local<T>::New(Isolate* isolate, T* that) {
 template<class T>
 template<class S>
 void Eternal<T>::Set(Isolate* isolate, Local<S> handle) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   val_ = reinterpret_cast<T*>(
       V8::Eternalize(isolate, reinterpret_cast<Value*>(*handle)));
 }
@@ -10676,7 +10755,7 @@ T* PersistentBase<T>::New(Isolate* isolate, T* that) {
 template <class T, class M>
 template <class S, class M2>
 void Persistent<T, M>::Copy(const Persistent<S, M2>& that) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   this->Reset();
   if (that.IsEmpty()) return;
   internal::Address* p = reinterpret_cast<internal::Address*>(that.val_);
@@ -10704,7 +10783,7 @@ void PersistentBase<T>::Reset() {
 template <class T>
 template <class S>
 void PersistentBase<T>::Reset(Isolate* isolate, const Local<S>& other) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   Reset();
   if (other.IsEmpty()) return;
   this->val_ = New(isolate, other.val_);
@@ -10715,7 +10794,7 @@ template <class T>
 template <class S>
 void PersistentBase<T>::Reset(Isolate* isolate,
                               const PersistentBase<S>& other) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   Reset();
   if (other.IsEmpty()) return;
   this->val_ = New(isolate, other.val_);
@@ -10781,7 +10860,7 @@ Global<T>::Global(Global&& other) : PersistentBase<T>(other.val_) {
 template <class T>
 template <class S>
 Global<T>& Global<T>::operator=(Global<S>&& rhs) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   if (this != &rhs) {
     this->Reset();
     if (rhs.val_ != nullptr) {
@@ -10816,7 +10895,7 @@ void TracedReferenceBase<T>::Reset() {
 template <class T>
 template <class S>
 void TracedGlobal<T>::Reset(Isolate* isolate, const Local<S>& other) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   Reset();
   if (other.IsEmpty()) return;
   this->val_ = this->New(isolate, other.val_, &this->val_,
@@ -10826,7 +10905,7 @@ void TracedGlobal<T>::Reset(Isolate* isolate, const Local<S>& other) {
 template <class T>
 template <class S>
 TracedGlobal<T>& TracedGlobal<T>::operator=(TracedGlobal<S>&& rhs) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   *this = std::move(rhs.template As<T>());
   return *this;
 }
@@ -10834,7 +10913,7 @@ TracedGlobal<T>& TracedGlobal<T>::operator=(TracedGlobal<S>&& rhs) {
 template <class T>
 template <class S>
 TracedGlobal<T>& TracedGlobal<T>::operator=(const TracedGlobal<S>& rhs) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   *this = rhs.template As<T>();
   return *this;
 }
@@ -10865,7 +10944,7 @@ TracedGlobal<T>& TracedGlobal<T>::operator=(const TracedGlobal& rhs) {
 template <class T>
 template <class S>
 void TracedReference<T>::Reset(Isolate* isolate, const Local<S>& other) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   Reset();
   if (other.IsEmpty()) return;
   this->val_ = this->New(isolate, other.val_, &this->val_,
@@ -10875,7 +10954,7 @@ void TracedReference<T>::Reset(Isolate* isolate, const Local<S>& other) {
 template <class T>
 template <class S>
 TracedReference<T>& TracedReference<T>::operator=(TracedReference<S>&& rhs) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   *this = std::move(rhs.template As<T>());
   return *this;
 }
@@ -10884,7 +10963,7 @@ template <class T>
 template <class S>
 TracedReference<T>& TracedReference<T>::operator=(
     const TracedReference<S>& rhs) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   *this = rhs.template As<T>();
   return *this;
 }
@@ -10937,20 +11016,13 @@ void TracedGlobal<T>::SetFinalizationCallback(
       reinterpret_cast<internal::Address*>(this->val_), parameter, callback);
 }
 
-template <class T>
-void TracedReference<T>::SetFinalizationCallback(
-    void* parameter, typename WeakCallbackInfo<void>::Callback callback) {
-  V8::SetFinalizationCallbackTraced(
-      reinterpret_cast<internal::Address*>(this->val_), parameter, callback);
-}
-
 template <typename T>
 ReturnValue<T>::ReturnValue(internal::Address* slot) : value_(slot) {}
 
 template <typename T>
 template <typename S>
 void ReturnValue<T>::Set(const Global<S>& handle) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   if (V8_UNLIKELY(handle.IsEmpty())) {
     *value_ = GetDefaultValue();
   } else {
@@ -10961,7 +11033,7 @@ void ReturnValue<T>::Set(const Global<S>& handle) {
 template <typename T>
 template <typename S>
 void ReturnValue<T>::Set(const TracedReferenceBase<S>& handle) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_base_of<T, S>::value, "type check");
   if (V8_UNLIKELY(handle.IsEmpty())) {
     *value_ = GetDefaultValue();
   } else {
@@ -10972,7 +11044,8 @@ void ReturnValue<T>::Set(const TracedReferenceBase<S>& handle) {
 template <typename T>
 template <typename S>
 void ReturnValue<T>::Set(const Local<S> handle) {
-  TYPE_CHECK(T, S);
+  static_assert(std::is_void<T>::value || std::is_base_of<T, S>::value,
+                "type check");
   if (V8_UNLIKELY(handle.IsEmpty())) {
     *value_ = GetDefaultValue();
   } else {
@@ -10982,13 +11055,13 @@ void ReturnValue<T>::Set(const Local<S> handle) {
 
 template<typename T>
 void ReturnValue<T>::Set(double i) {
-  TYPE_CHECK(T, Number);
+  static_assert(std::is_base_of<T, Number>::value, "type check");
   Set(Number::New(GetIsolate(), i));
 }
 
 template<typename T>
 void ReturnValue<T>::Set(int32_t i) {
-  TYPE_CHECK(T, Integer);
+  static_assert(std::is_base_of<T, Integer>::value, "type check");
   typedef internal::Internals I;
   if (V8_LIKELY(I::IsValidSmi(i))) {
     *value_ = I::IntToSmi(i);
@@ -10999,7 +11072,7 @@ void ReturnValue<T>::Set(int32_t i) {
 
 template<typename T>
 void ReturnValue<T>::Set(uint32_t i) {
-  TYPE_CHECK(T, Integer);
+  static_assert(std::is_base_of<T, Integer>::value, "type check");
   // Can't simply use INT32_MAX here for whatever reason.
   bool fits_into_int32_t = (i & (1U << 31)) == 0;
   if (V8_LIKELY(fits_into_int32_t)) {
@@ -11011,7 +11084,7 @@ void ReturnValue<T>::Set(uint32_t i) {
 
 template<typename T>
 void ReturnValue<T>::Set(bool value) {
-  TYPE_CHECK(T, Boolean);
+  static_assert(std::is_base_of<T, Boolean>::value, "type check");
   typedef internal::Internals I;
   int root_index;
   if (value) {
@@ -11024,21 +11097,21 @@ void ReturnValue<T>::Set(bool value) {
 
 template<typename T>
 void ReturnValue<T>::SetNull() {
-  TYPE_CHECK(T, Primitive);
+  static_assert(std::is_base_of<T, Primitive>::value, "type check");
   typedef internal::Internals I;
   *value_ = *I::GetRoot(GetIsolate(), I::kNullValueRootIndex);
 }
 
 template<typename T>
 void ReturnValue<T>::SetUndefined() {
-  TYPE_CHECK(T, Primitive);
+  static_assert(std::is_base_of<T, Primitive>::value, "type check");
   typedef internal::Internals I;
   *value_ = *I::GetRoot(GetIsolate(), I::kUndefinedValueRootIndex);
 }
 
 template<typename T>
 void ReturnValue<T>::SetEmptyString() {
-  TYPE_CHECK(T, String);
+  static_assert(std::is_base_of<T, String>::value, "type check");
   typedef internal::Internals I;
   *value_ = *I::GetRoot(GetIsolate(), I::kEmptyStringRootIndex);
 }
@@ -11060,8 +11133,7 @@ Local<Value> ReturnValue<T>::Get() const {
 template <typename T>
 template <typename S>
 void ReturnValue<T>::Set(S* whatever) {
-  // Uncompilable to prevent inadvertent misuse.
-  TYPE_CHECK(S*, Primitive);
+  static_assert(sizeof(S) < 0, "incompilable to prevent inadvertent misuse");
 }
 
 template <typename T>
@@ -11078,14 +11150,24 @@ FunctionCallbackInfo<T>::FunctionCallbackInfo(internal::Address* implicit_args,
 
 template<typename T>
 Local<Value> FunctionCallbackInfo<T>::operator[](int i) const {
+  // values_ points to the first argument (not the receiver).
   if (i < 0 || length_ <= i) return Local<Value>(*Undefined(GetIsolate()));
+#ifdef V8_REVERSE_JSARGS
+  return Local<Value>(reinterpret_cast<Value*>(values_ + i));
+#else
   return Local<Value>(reinterpret_cast<Value*>(values_ - i));
+#endif
 }
 
 
 template<typename T>
 Local<Object> FunctionCallbackInfo<T>::This() const {
+  // values_ points to the first argument (not the receiver).
+#ifdef V8_REVERSE_JSARGS
+  return Local<Object>(reinterpret_cast<Object*>(values_ - 1));
+#else
   return Local<Object>(reinterpret_cast<Object*>(values_ + 1));
+#endif
 }
 
 
@@ -11854,9 +11936,9 @@ int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
       reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryOffset);
   int64_t* external_memory_limit = reinterpret_cast<int64_t*>(
       reinterpret_cast<uint8_t*>(this) + I::kExternalMemoryLimitOffset);
-  int64_t* external_memory_at_last_mc =
+  int64_t* external_memory_low_since_mc =
       reinterpret_cast<int64_t*>(reinterpret_cast<uint8_t*>(this) +
-                                 I::kExternalMemoryAtLastMarkCompactOffset);
+                                 I::kExternalMemoryLowSinceMarkCompactOffset);
 
   // Embedders are weird: we see both over- and underflows here. Perform the
   // addition with unsigned types to avoid undefined behavior.
@@ -11865,23 +11947,22 @@ int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
                            static_cast<uint64_t>(*external_memory));
   *external_memory = amount;
 
-  int64_t allocation_diff_since_last_mc =
-      static_cast<int64_t>(static_cast<uint64_t>(*external_memory) -
-                           static_cast<uint64_t>(*external_memory_at_last_mc));
+  if (amount < *external_memory_low_since_mc) {
+    *external_memory_low_since_mc = amount;
+    *external_memory_limit = amount + I::kExternalAllocationSoftLimit;
+  }
+
+  if (change_in_bytes <= 0) return *external_memory;
+
+  int64_t allocation_diff_since_last_mc = static_cast<int64_t>(
+      static_cast<uint64_t>(*external_memory) -
+      static_cast<uint64_t>(*external_memory_low_since_mc));
   // Only check memory pressure and potentially trigger GC if the amount of
   // external memory increased.
   if (allocation_diff_since_last_mc > kMemoryReducerActivationLimit) {
     CheckMemoryPressure();
   }
-
-  if (change_in_bytes < 0) {
-    const int64_t lower_limit =
-        static_cast<int64_t>(static_cast<uint64_t>(*external_memory_limit) +
-                             static_cast<uint64_t>(change_in_bytes));
-    if (lower_limit > I::kExternalAllocationSoftLimit) {
-      *external_memory_limit = lower_limit;
-    }
-  } else if (change_in_bytes > 0 && amount > *external_memory_limit) {
+  if (amount > *external_memory_limit) {
     ReportExternalAllocationLimitReached();
   }
   return *external_memory;
@@ -11963,8 +12044,4 @@ size_t SnapshotCreator::AddData(Local<T> object) {
 
 }  // namespace v8
 
-
-#undef TYPE_CHECK
-
-
 #endif  // INCLUDE_V8_H_
diff --git a/deps/v8/infra/testing/builders.pyl b/deps/v8/infra/testing/builders.pyl
index b26f1a1f08..6c3379b5cb 100644
--- a/deps/v8/infra/testing/builders.pyl
+++ b/deps/v8/infra/testing/builders.pyl
@@ -288,7 +288,8 @@
       {'name': 'test262', 'variant': 'extra', 'shards': 3},
       {'name': 'v8testing', 'shards': 3},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 3},
-      {'name': 'v8testing', 'variant': 'minor_mc', 'shards': 1},
+      {'name': 'v8testing', 'variant': 'minor_mc'},
+      {'name': 'v8testing', 'variant': 'no_lfa'},
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
     ],
   },
@@ -346,6 +347,7 @@
       {'name': 'v8testing', 'shards': 2},
       {'name': 'v8testing', 'variant': 'assert_types'},
       {'name': 'v8testing', 'variant': 'extra'},
+      {'name': 'v8testing', 'variant': 'no_lfa'},
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
     ],
   },
@@ -381,6 +383,7 @@
       {'name': 'v8testing', 'shards': 2},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
       {'name': 'v8testing', 'variant': 'minor_mc'},
+      {'name': 'v8testing', 'variant': 'no_lfa'},
       {'name': 'v8testing', 'variant': 'slow_path'},
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
     ],
@@ -849,7 +852,8 @@
       {'name': 'v8testing'},
       {'name': 'v8testing', 'variant': 'assert_types'},
       {'name': 'v8testing', 'variant': 'extra'},
-      {'name': 'v8testing', 'variant': 'minor_mc', 'shards': 1},
+      {'name': 'v8testing', 'variant': 'minor_mc'},
+      {'name': 'v8testing', 'variant': 'no_lfa'},
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
       # Noavx.
       {
@@ -906,8 +910,9 @@
       {'name': 'test262', 'variant': 'extra', 'shards': 3},
       {'name': 'v8testing', 'shards': 2},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
-      {'name': 'v8testing', 'variant': 'minor_mc', 'shards': 1},
-      {'name': 'v8testing', 'variant': 'slow_path', 'shards': 1},
+      {'name': 'v8testing', 'variant': 'minor_mc'},
+      {'name': 'v8testing', 'variant': 'no_lfa'},
+      {'name': 'v8testing', 'variant': 'slow_path'},
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
       # Noavx.
       {
@@ -1417,7 +1422,7 @@
       {'name': 'mozilla'},
       {'name': 'test262', 'variant': 'default'},
       {'name': 'v8testing', 'shards': 3},
-      {'name': 'v8testing', 'variant': 'extra'},
+      {'name': 'v8testing', 'variant': 'extra', 'shards': 2},
       {'name': 'v8testing', 'variant': 'trusted'},
     ],
   },
diff --git a/deps/v8/samples/hello-world.cc b/deps/v8/samples/hello-world.cc
index d75dcb3c3c..6e506475e4 100644
--- a/deps/v8/samples/hello-world.cc
+++ b/deps/v8/samples/hello-world.cc
@@ -37,9 +37,7 @@ int main(int argc, char* argv[]) {
     {
       // Create a string containing the JavaScript source code.
       v8::Local<v8::String> source =
-          v8::String::NewFromUtf8(isolate, "'Hello' + ', World!'",
-                                  v8::NewStringType::kNormal)
-              .ToLocalChecked();
+          v8::String::NewFromUtf8Literal(isolate, "'Hello' + ', World!'");
 
       // Compile the source code.
       v8::Local<v8::Script> script =
@@ -63,7 +61,7 @@ int main(int argc, char* argv[]) {
       //       get_local 1
       //       i32.add)
       //
-      const char* csource = R"(
+      const char csource[] = R"(
         let bytes = new Uint8Array([
           0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x07, 0x01,
           0x60, 0x02, 0x7f, 0x7f, 0x01, 0x7f, 0x03, 0x02, 0x01, 0x00, 0x07,
@@ -77,8 +75,7 @@ int main(int argc, char* argv[]) {
 
       // Create a string containing the JavaScript source code.
       v8::Local<v8::String> source =
-          v8::String::NewFromUtf8(isolate, csource, v8::NewStringType::kNormal)
-              .ToLocalChecked();
+          v8::String::NewFromUtf8Literal(isolate, csource);
 
       // Compile the source code.
       v8::Local<v8::Script> script =
diff --git a/deps/v8/samples/process.cc b/deps/v8/samples/process.cc
index e4f6fd9cee..b23329dc10 100644
--- a/deps/v8/samples/process.cc
+++ b/deps/v8/samples/process.cc
@@ -183,8 +183,7 @@ bool JsHttpRequestProcessor::Initialize(map<string, string>* opts,
   // Create a template for the global object where we set the
   // built-in global functions.
   Local<ObjectTemplate> global = ObjectTemplate::New(GetIsolate());
-  global->Set(String::NewFromUtf8(GetIsolate(), "log", NewStringType::kNormal)
-                  .ToLocalChecked(),
+  global->Set(String::NewFromUtf8Literal(GetIsolate(), "log"),
               FunctionTemplate::New(GetIsolate(), LogCallback));
 
   // Each processor gets its own context so different processors don't
@@ -210,8 +209,7 @@ bool JsHttpRequestProcessor::Initialize(map<string, string>* opts,
   // The script compiled and ran correctly.  Now we fetch out the
   // Process function from the global object.
   Local<String> process_name =
-      String::NewFromUtf8(GetIsolate(), "Process", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(GetIsolate(), "Process");
   Local<Value> process_val;
   // If there is no Process function, or if it is not a function,
   // bail out
@@ -276,17 +274,13 @@ bool JsHttpRequestProcessor::InstallMaps(map<string, string>* opts,
 
   // Set the options object as a property on the global object.
   context->Global()
-      ->Set(context,
-            String::NewFromUtf8(GetIsolate(), "options", NewStringType::kNormal)
-                .ToLocalChecked(),
+      ->Set(context, String::NewFromUtf8Literal(GetIsolate(), "options"),
             opts_obj)
       .FromJust();
 
   Local<Object> output_obj = WrapMap(output);
   context->Global()
-      ->Set(context,
-            String::NewFromUtf8(GetIsolate(), "output", NewStringType::kNormal)
-                .ToLocalChecked(),
+      ->Set(context, String::NewFromUtf8Literal(GetIsolate(), "output"),
             output_obj)
       .FromJust();
 
@@ -563,21 +557,17 @@ Local<ObjectTemplate> JsHttpRequestProcessor::MakeRequestTemplate(
 
   // Add accessors for each of the fields of the request.
   result->SetAccessor(
-      String::NewFromUtf8(isolate, "path", NewStringType::kInternalized)
-          .ToLocalChecked(),
+      String::NewFromUtf8Literal(isolate, "path", NewStringType::kInternalized),
       GetPath);
+  result->SetAccessor(String::NewFromUtf8Literal(isolate, "referrer",
+                                                 NewStringType::kInternalized),
+                      GetReferrer);
   result->SetAccessor(
-      String::NewFromUtf8(isolate, "referrer", NewStringType::kInternalized)
-          .ToLocalChecked(),
-      GetReferrer);
-  result->SetAccessor(
-      String::NewFromUtf8(isolate, "host", NewStringType::kInternalized)
-          .ToLocalChecked(),
+      String::NewFromUtf8Literal(isolate, "host", NewStringType::kInternalized),
       GetHost);
-  result->SetAccessor(
-      String::NewFromUtf8(isolate, "userAgent", NewStringType::kInternalized)
-          .ToLocalChecked(),
-      GetUserAgent);
+  result->SetAccessor(String::NewFromUtf8Literal(isolate, "userAgent",
+                                                 NewStringType::kInternalized),
+                      GetUserAgent);
 
   // Again, return the result through the current handle scope.
   return handle_scope.Escape(result);
diff --git a/deps/v8/samples/shell.cc b/deps/v8/samples/shell.cc
index 81b028720c..aed050cecc 100644
--- a/deps/v8/samples/shell.cc
+++ b/deps/v8/samples/shell.cc
@@ -108,27 +108,20 @@ v8::Local<v8::Context> CreateShellContext(v8::Isolate* isolate) {
   // Create a template for the global object.
   v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
   // Bind the global 'print' function to the C++ Print callback.
-  global->Set(
-      v8::String::NewFromUtf8(isolate, "print", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
-      v8::FunctionTemplate::New(isolate, Print));
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "print"),
+              v8::FunctionTemplate::New(isolate, Print));
   // Bind the global 'read' function to the C++ Read callback.
-  global->Set(v8::String::NewFromUtf8(
-                  isolate, "read", v8::NewStringType::kNormal).ToLocalChecked(),
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "read"),
               v8::FunctionTemplate::New(isolate, Read));
   // Bind the global 'load' function to the C++ Load callback.
-  global->Set(v8::String::NewFromUtf8(
-                  isolate, "load", v8::NewStringType::kNormal).ToLocalChecked(),
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "load"),
               v8::FunctionTemplate::New(isolate, Load));
   // Bind the 'quit' function
-  global->Set(v8::String::NewFromUtf8(
-                  isolate, "quit", v8::NewStringType::kNormal).ToLocalChecked(),
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "quit"),
               v8::FunctionTemplate::New(isolate, Quit));
   // Bind the 'version' function
-  global->Set(
-      v8::String::NewFromUtf8(isolate, "version", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
-      v8::FunctionTemplate::New(isolate, Version));
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "version"),
+              v8::FunctionTemplate::New(isolate, Version));
 
   return v8::Context::New(isolate, NULL, global);
 }
@@ -161,22 +154,19 @@ void Print(const v8::FunctionCallbackInfo<v8::Value>& args) {
 void Read(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
     args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(), "Bad parameters",
-                                v8::NewStringType::kNormal).ToLocalChecked());
+        v8::String::NewFromUtf8Literal(args.GetIsolate(), "Bad parameters"));
     return;
   }
   v8::String::Utf8Value file(args.GetIsolate(), args[0]);
   if (*file == NULL) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file",
-                                v8::NewStringType::kNormal).ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(), "Error loading file"));
     return;
   }
   v8::Local<v8::String> source;
   if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file",
-                                v8::NewStringType::kNormal).ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(), "Error loading file"));
     return;
   }
 
@@ -191,22 +181,19 @@ void Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
     v8::HandleScope handle_scope(args.GetIsolate());
     v8::String::Utf8Value file(args.GetIsolate(), args[i]);
     if (*file == NULL) {
-      args.GetIsolate()->ThrowException(
-          v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file",
-                                  v8::NewStringType::kNormal).ToLocalChecked());
+      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+          args.GetIsolate(), "Error loading file"));
       return;
     }
     v8::Local<v8::String> source;
     if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) {
-      args.GetIsolate()->ThrowException(
-          v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file",
-                                  v8::NewStringType::kNormal).ToLocalChecked());
+      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+          args.GetIsolate(), "Error loading file"));
       return;
     }
     if (!ExecuteString(args.GetIsolate(), source, args[i], false, false)) {
-      args.GetIsolate()->ThrowException(
-          v8::String::NewFromUtf8(args.GetIsolate(), "Error executing file",
-                                  v8::NewStringType::kNormal).ToLocalChecked());
+      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+          args.GetIsolate(), "Error executing file"));
       return;
     }
   }
@@ -228,8 +215,8 @@ void Quit(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Version(const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetReturnValue().Set(
-      v8::String::NewFromUtf8(args.GetIsolate(), v8::V8::GetVersion(),
-                              v8::NewStringType::kNormal).ToLocalChecked());
+      v8::String::NewFromUtf8(args.GetIsolate(), v8::V8::GetVersion())
+          .ToLocalChecked());
 }
 
 
@@ -276,12 +263,9 @@ int RunMain(v8::Isolate* isolate, v8::Platform* platform, int argc,
     } else if (strcmp(str, "-e") == 0 && i + 1 < argc) {
       // Execute argument given to -e option directly.
       v8::Local<v8::String> file_name =
-          v8::String::NewFromUtf8(isolate, "unnamed",
-                                  v8::NewStringType::kNormal).ToLocalChecked();
+          v8::String::NewFromUtf8Literal(isolate, "unnamed");
       v8::Local<v8::String> source;
-      if (!v8::String::NewFromUtf8(isolate, argv[++i],
-                                   v8::NewStringType::kNormal)
-               .ToLocal(&source)) {
+      if (!v8::String::NewFromUtf8(isolate, argv[++i]).ToLocal(&source)) {
         return 1;
       }
       bool success = ExecuteString(isolate, source, file_name, false, true);
@@ -290,8 +274,7 @@ int RunMain(v8::Isolate* isolate, v8::Platform* platform, int argc,
     } else {
       // Use all other arguments as names of files to load and run.
       v8::Local<v8::String> file_name =
-          v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kNormal)
-              .ToLocalChecked();
+          v8::String::NewFromUtf8(isolate, str).ToLocalChecked();
       v8::Local<v8::String> source;
       if (!ReadFile(isolate, str).ToLocal(&source)) {
         fprintf(stderr, "Error reading '%s'\n", str);
@@ -313,8 +296,7 @@ void RunShell(v8::Local<v8::Context> context, v8::Platform* platform) {
   // Enter the execution environment before evaluating any code.
   v8::Context::Scope context_scope(context);
   v8::Local<v8::String> name(
-      v8::String::NewFromUtf8(context->GetIsolate(), "(shell)",
-                              v8::NewStringType::kNormal).ToLocalChecked());
+      v8::String::NewFromUtf8Literal(context->GetIsolate(), "(shell)"));
   while (true) {
     char buffer[kBufferSize];
     fprintf(stderr, "> ");
@@ -323,8 +305,7 @@ void RunShell(v8::Local<v8::Context> context, v8::Platform* platform) {
     v8::HandleScope handle_scope(context->GetIsolate());
     ExecuteString(
         context->GetIsolate(),
-        v8::String::NewFromUtf8(context->GetIsolate(), str,
-                                v8::NewStringType::kNormal).ToLocalChecked(),
+        v8::String::NewFromUtf8(context->GetIsolate(), str).ToLocalChecked(),
         name, true, true);
     while (v8::platform::PumpMessageLoop(platform, context->GetIsolate()))
       continue;
diff --git a/deps/v8/src/DEPS b/deps/v8/src/DEPS
index 3e802dac97..772ad53b32 100644
--- a/deps/v8/src/DEPS
+++ b/deps/v8/src/DEPS
@@ -16,6 +16,7 @@ include_rules = [
   "+src/heap/heap-inl.h",
   "+src/heap/heap-write-barrier-inl.h",
   "+src/heap/heap-write-barrier.h",
+  "+src/heap/local-heap.h",
   "+src/heap/off-thread-factory-inl.h",
   "+src/heap/off-thread-factory.h",
   "+src/heap/read-only-heap-inl.h",
diff --git a/deps/v8/src/api/api-inl.h b/deps/v8/src/api/api-inl.h
index 217d21222d..0d2ad2f8a0 100644
--- a/deps/v8/src/api/api-inl.h
+++ b/deps/v8/src/api/api-inl.h
@@ -86,7 +86,7 @@ MAKE_TO_LOCAL(ToLocal, JSArrayBufferView, ArrayBufferView)
 MAKE_TO_LOCAL(ToLocal, JSDataView, DataView)
 MAKE_TO_LOCAL(ToLocal, JSTypedArray, TypedArray)
 MAKE_TO_LOCAL(ToLocalShared, JSArrayBuffer, SharedArrayBuffer)
-MAKE_TO_LOCAL(ToLocal, JSFinalizationGroup, FinalizationGroup)
+MAKE_TO_LOCAL(ToLocal, JSFinalizationRegistry, FinalizationGroup)
 
 TYPED_ARRAYS(MAKE_TO_LOCAL_TYPED_ARRAY)
 
diff --git a/deps/v8/src/api/api.cc b/deps/v8/src/api/api.cc
index 7fe974de24..b2d6db3661 100644
--- a/deps/v8/src/api/api.cc
+++ b/deps/v8/src/api/api.cc
@@ -13,6 +13,7 @@
 
 #include "src/api/api-inl.h"
 
+#include "include/v8-fast-api-calls.h"
 #include "include/v8-profiler.h"
 #include "include/v8-util.h"
 #include "src/api/api-natives.h"
@@ -309,6 +310,7 @@ class CallDepthScope {
 #ifdef V8_CHECK_MICROTASKS_SCOPES_CONSISTENCY
     if (do_callback) CheckMicrotasksScopesConsistency(microtask_queue);
 #endif
+    DCHECK(CheckKeptObjectsClearedAfterMicrotaskCheckpoint(microtask_queue));
     isolate_->set_next_v8_call_is_safe_for_termination(safe_for_termination_);
   }
 
@@ -323,6 +325,15 @@ class CallDepthScope {
   }
 
  private:
+  bool CheckKeptObjectsClearedAfterMicrotaskCheckpoint(
+      i::MicrotaskQueue* microtask_queue) {
+    bool did_perform_microtask_checkpoint =
+        do_callback && microtask_queue &&
+        microtask_queue->microtasks_policy() == MicrotasksPolicy::kAuto;
+    return !did_perform_microtask_checkpoint ||
+           isolate_->heap()->weak_refs_keep_during_job().IsUndefined(isolate_);
+  }
+
   i::Isolate* const isolate_;
   Local<Context> context_;
   bool escaped_;
@@ -453,11 +464,13 @@ void i::V8::FatalProcessOutOfMemory(i::Isolate* isolate, const char* location,
     // BUG(1718): Don't use the take_snapshot since we don't support
     // HeapObjectIterator here without doing a special GC.
     isolate->heap()->RecordStats(&heap_stats, false);
-    char* first_newline = strchr(last_few_messages, '\n');
-    if (first_newline == nullptr || first_newline[1] == '\0')
-      first_newline = last_few_messages;
-    PrintF("\n<--- Last few GCs --->\n%s\n", first_newline);
-    PrintF("\n<--- JS stacktrace --->\n%s\n", js_stacktrace);
+    if (!FLAG_correctness_fuzzer_suppressions) {
+      char* first_newline = strchr(last_few_messages, '\n');
+      if (first_newline == nullptr || first_newline[1] == '\0')
+        first_newline = last_few_messages;
+      base::OS::PrintError("\n<--- Last few GCs --->\n%s\n", first_newline);
+      base::OS::PrintError("\n<--- JS stacktrace --->\n%s\n", js_stacktrace);
+    }
   }
   Utils::ReportOOMFailure(isolate, location, is_heap_oom);
   // If the fatal error handler returns, we stop execution.
@@ -542,6 +555,21 @@ class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
   }
 
   void Free(void* data, size_t) override { free(data); }
+
+  void* Reallocate(void* data, size_t old_length, size_t new_length) override {
+#if V8_OS_AIX && _LINUX_SOURCE_COMPAT
+    // Work around for GCC bug on AIX
+    // See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79839
+    void* new_data = __linux_realloc(data, new_length);
+#else
+    void* new_data = realloc(data, new_length);
+#endif
+    if (new_length > old_length) {
+      memset(reinterpret_cast<uint8_t*>(new_data) + old_length, 0,
+             new_length - old_length);
+    }
+    return new_data;
+  }
 };
 
 struct SnapshotCreatorData {
@@ -867,6 +895,8 @@ StartupData SnapshotCreator::CreateBlob(
   startup_serializer.SerializeWeakReferencesAndDeferred();
   can_be_rehashed = can_be_rehashed && startup_serializer.can_be_rehashed();
 
+  startup_serializer.CheckNoDirtyFinalizationRegistries();
+
   read_only_serializer.FinalizeSerialization();
   can_be_rehashed = can_be_rehashed && read_only_serializer.can_be_rehashed();
 
@@ -985,7 +1015,7 @@ void ResourceConstraints::ConfigureDefaultsFromHeapSize(
     set_initial_young_generation_size_in_bytes(young_generation);
     set_initial_old_generation_size_in_bytes(old_generation);
   }
-  if (i::kRequiresCodeRange) {
+  if (i::kPlatformRequiresCodeRange) {
     set_code_range_size_in_bytes(
         i::Min(i::kMaximalCodeRangeSize, maximum_heap_size_in_bytes));
   }
@@ -1000,7 +1030,7 @@ void ResourceConstraints::ConfigureDefaults(uint64_t physical_memory,
   set_max_young_generation_size_in_bytes(young_generation);
   set_max_old_generation_size_in_bytes(old_generation);
 
-  if (virtual_memory_limit > 0 && i::kRequiresCodeRange) {
+  if (virtual_memory_limit > 0 && i::kPlatformRequiresCodeRange) {
     set_code_range_size_in_bytes(
         i::Min(i::kMaximalCodeRangeSize,
                static_cast<size_t>(virtual_memory_limit / 8)));
@@ -1442,7 +1472,8 @@ static Local<FunctionTemplate> FunctionTemplateNew(
     i::Isolate* isolate, FunctionCallback callback, v8::Local<Value> data,
     v8::Local<Signature> signature, int length, bool do_not_cache,
     v8::Local<Private> cached_property_name = v8::Local<Private>(),
-    SideEffectType side_effect_type = SideEffectType::kHasSideEffect) {
+    SideEffectType side_effect_type = SideEffectType::kHasSideEffect,
+    const CFunction* c_function = nullptr) {
   i::Handle<i::Struct> struct_obj = isolate->factory()->NewStruct(
       i::FUNCTION_TEMPLATE_INFO_TYPE, i::AllocationType::kOld);
   i::Handle<i::FunctionTemplateInfo> obj =
@@ -1460,7 +1491,8 @@ static Local<FunctionTemplate> FunctionTemplateNew(
     obj->set_serial_number(i::Smi::FromInt(next_serial_number));
   }
   if (callback != nullptr) {
-    Utils::ToLocal(obj)->SetCallHandler(callback, data, side_effect_type);
+    Utils::ToLocal(obj)->SetCallHandler(callback, data, side_effect_type,
+                                        c_function);
   }
   obj->set_undetectable(false);
   obj->set_needs_access_check(false);
@@ -1478,14 +1510,15 @@ static Local<FunctionTemplate> FunctionTemplateNew(
 Local<FunctionTemplate> FunctionTemplate::New(
     Isolate* isolate, FunctionCallback callback, v8::Local<Value> data,
     v8::Local<Signature> signature, int length, ConstructorBehavior behavior,
-    SideEffectType side_effect_type) {
+    SideEffectType side_effect_type, const CFunction* c_function) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   // Changes to the environment cannot be captured in the snapshot. Expect no
   // function templates when the isolate is created for serialization.
   LOG_API(i_isolate, FunctionTemplate, New);
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
-  auto templ = FunctionTemplateNew(i_isolate, callback, data, signature, length,
-                                   false, Local<Private>(), side_effect_type);
+  auto templ =
+      FunctionTemplateNew(i_isolate, callback, data, signature, length, false,
+                          Local<Private>(), side_effect_type, c_function);
   if (behavior == ConstructorBehavior::kThrow) templ->RemovePrototype();
   return templ;
 }
@@ -1534,7 +1567,8 @@ Local<AccessorSignature> AccessorSignature::New(
 
 void FunctionTemplate::SetCallHandler(FunctionCallback callback,
                                       v8::Local<Value> data,
-                                      SideEffectType side_effect_type) {
+                                      SideEffectType side_effect_type,
+                                      const CFunction* c_function) {
   auto info = Utils::OpenHandle(this);
   EnsureNotInstantiated(info, "v8::FunctionTemplate::SetCallHandler");
   i::Isolate* isolate = info->GetIsolate();
@@ -1548,6 +1582,15 @@ void FunctionTemplate::SetCallHandler(FunctionCallback callback,
     data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
   }
   obj->set_data(*Utils::OpenHandle(*data));
+  if (c_function != nullptr) {
+    DCHECK_NOT_NULL(c_function->GetAddress());
+    i::FunctionTemplateInfo::SetCFunction(
+        isolate, info,
+        i::handle(*FromCData(isolate, c_function->GetAddress()), isolate));
+    i::FunctionTemplateInfo::SetCSignature(
+        isolate, info,
+        i::handle(*FromCData(isolate, c_function->GetTypeInfo()), isolate));
+  }
   info->set_call_code(*obj);
 }
 
@@ -3462,7 +3505,6 @@ VALUE_IS_SPECIFIC_TYPE(Set, JSSet)
 VALUE_IS_SPECIFIC_TYPE(WasmModuleObject, WasmModuleObject)
 VALUE_IS_SPECIFIC_TYPE(WeakMap, JSWeakMap)
 VALUE_IS_SPECIFIC_TYPE(WeakSet, JSWeakSet)
-VALUE_IS_SPECIFIC_TYPE(WebAssemblyCompiledModule, WasmModuleObject)
 
 #undef VALUE_IS_SPECIFIC_TYPE
 
@@ -3784,6 +3826,28 @@ bool v8::BackingStore::IsShared() const {
   return reinterpret_cast<const i::BackingStore*>(this)->is_shared();
 }
 
+// static
+std::unique_ptr<v8::BackingStore> v8::BackingStore::Reallocate(
+    v8::Isolate* isolate, std::unique_ptr<v8::BackingStore> backing_store,
+    size_t byte_length) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  LOG_API(i_isolate, ArrayBuffer, BackingStore_Reallocate);
+  CHECK_LE(byte_length, i::JSArrayBuffer::kMaxByteLength);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
+  i::BackingStore* i_backing_store =
+      reinterpret_cast<i::BackingStore*>(backing_store.get());
+  if (!i_backing_store->Reallocate(i_isolate, byte_length)) {
+    i::FatalProcessOutOfMemory(i_isolate, "v8::BackingStore::Reallocate");
+  }
+  return backing_store;
+}
+
+// static
+void v8::BackingStore::EmptyDeleter(void* data, size_t length,
+                                    void* deleter_data) {
+  DCHECK_NULL(deleter_data);
+}
+
 std::shared_ptr<v8::BackingStore> v8::ArrayBuffer::GetBackingStore() {
   i::Handle<i::JSArrayBuffer> self = Utils::OpenHandle(this);
   std::shared_ptr<i::BackingStore> backing_store = self->GetBackingStore();
@@ -4800,6 +4864,11 @@ bool v8::Object::IsApiWrapper() {
   return self->IsApiWrapper();
 }
 
+bool v8::Object::IsUndetectable() {
+  auto self = i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
+  return self->IsUndetectable();
+}
+
 MaybeLocal<Value> Object::CallAsFunction(Local<Context> context,
                                          Local<Value> recv, int argc,
                                          Local<Value> argv[]) {
@@ -6085,6 +6154,24 @@ void Context::SetAbortScriptExecution(
   }
 }
 
+Local<Value> Context::GetContinuationPreservedEmbedderData() const {
+  i::Handle<i::Context> context = Utils::OpenHandle(this);
+  i::Isolate* isolate = context->GetIsolate();
+  i::Handle<i::Object> data(
+      context->native_context().continuation_preserved_embedder_data(),
+      isolate);
+  return ToApiHandle<Object>(data);
+}
+
+void Context::SetContinuationPreservedEmbedderData(Local<Value> data) {
+  i::Handle<i::Context> context = Utils::OpenHandle(this);
+  i::Isolate* isolate = context->GetIsolate();
+  if (data.IsEmpty())
+    data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
+  context->native_context().set_continuation_preserved_embedder_data(
+      *i::Handle<i::HeapObject>::cast(Utils::OpenHandle(*data)));
+}
+
 namespace {
 i::Address* GetSerializedDataFromFixedArray(i::Isolate* isolate,
                                             i::FixedArray list, size_t index) {
@@ -6290,6 +6377,19 @@ STATIC_ASSERT(v8::String::kMaxLength == i::String::kMaxLength);
     result = Utils::ToLocal(handle_result);                                \
   }
 
+Local<String> String::NewFromUtf8Literal(Isolate* isolate, const char* literal,
+                                         NewStringType type, int length) {
+  DCHECK_LE(length, i::String::kMaxLength);
+  i::Isolate* i_isolate = reinterpret_cast<internal::Isolate*>(isolate);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
+  LOG_API(i_isolate, String, NewFromUtf8Literal);
+  i::Handle<i::String> handle_result =
+      NewString(i_isolate->factory(), type,
+                i::Vector<const char>(literal, length))
+          .ToHandleChecked();
+  return Utils::ToLocal(handle_result);
+}
+
 MaybeLocal<String> String::NewFromUtf8(Isolate* isolate, const char* data,
                                        NewStringType type, int length) {
   NEW_STRING(isolate, String, NewFromUtf8, char, data, type, length);
@@ -7197,57 +7297,6 @@ MaybeLocal<WasmModuleObject> WasmModuleObject::FromCompiledModule(
       Utils::ToLocal(i::Handle<i::JSObject>::cast(module_object)));
 }
 
-MaybeLocal<WasmModuleObject> WasmModuleObject::Deserialize(
-    Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
-    MemorySpan<const uint8_t> wire_bytes) {
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i::MaybeHandle<i::WasmModuleObject> maybe_module_object =
-      i::wasm::DeserializeNativeModule(
-          i_isolate, {serialized_module.data(), serialized_module.size()},
-          {wire_bytes.data(), wire_bytes.size()}, {});
-  i::Handle<i::WasmModuleObject> module_object;
-  if (!maybe_module_object.ToHandle(&module_object)) {
-    return MaybeLocal<WasmModuleObject>();
-  }
-  return Local<WasmModuleObject>::Cast(
-      Utils::ToLocal(i::Handle<i::JSObject>::cast(module_object)));
-}
-
-MaybeLocal<WasmModuleObject> WasmModuleObject::DeserializeOrCompile(
-    Isolate* isolate, MemorySpan<const uint8_t> serialized_module,
-    MemorySpan<const uint8_t> wire_bytes) {
-  MaybeLocal<WasmModuleObject> ret =
-      Deserialize(isolate, serialized_module, wire_bytes);
-  if (!ret.IsEmpty()) {
-    return ret;
-  }
-  return Compile(isolate, wire_bytes.data(), wire_bytes.size());
-}
-
-MaybeLocal<WasmModuleObject> WasmModuleObject::Compile(Isolate* isolate,
-                                                       const uint8_t* start,
-                                                       size_t length) {
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  if (!i::wasm::IsWasmCodegenAllowed(i_isolate, i_isolate->native_context())) {
-    return MaybeLocal<WasmModuleObject>();
-  }
-  i::MaybeHandle<i::JSObject> maybe_compiled;
-  {
-    i::wasm::ErrorThrower thrower(i_isolate, "WasmModuleObject::Compile()");
-    auto enabled_features = i::wasm::WasmFeatures::FromIsolate(i_isolate);
-    maybe_compiled = i_isolate->wasm_engine()->SyncCompile(
-        i_isolate, enabled_features, &thrower,
-        i::wasm::ModuleWireBytes(start, start + length));
-  }
-  CHECK_EQ(maybe_compiled.is_null(), i_isolate->has_pending_exception());
-  if (maybe_compiled.is_null()) {
-    i_isolate->OptionalRescheduleException(false);
-    return MaybeLocal<WasmModuleObject>();
-  }
-  return Local<WasmModuleObject>::Cast(
-      Utils::ToLocal(maybe_compiled.ToHandleChecked()));
-}
-
 WasmModuleObjectBuilderStreaming::WasmModuleObjectBuilderStreaming(
     Isolate* isolate) {
   USE(isolate_);
@@ -7262,6 +7311,21 @@ void WasmModuleObjectBuilderStreaming::Finish() {}
 
 void WasmModuleObjectBuilderStreaming::Abort(MaybeLocal<Value> exception) {}
 
+void* v8::ArrayBuffer::Allocator::Reallocate(void* data, size_t old_length,
+                                             size_t new_length) {
+  if (old_length == new_length) return data;
+  uint8_t* new_data =
+      reinterpret_cast<uint8_t*>(AllocateUninitialized(new_length));
+  if (new_data == nullptr) return nullptr;
+  size_t bytes_to_copy = std::min(old_length, new_length);
+  memcpy(new_data, data, bytes_to_copy);
+  if (new_length > bytes_to_copy) {
+    memset(new_data + bytes_to_copy, 0, new_length - bytes_to_copy);
+  }
+  Free(data, old_length);
+  return new_data;
+}
+
 // static
 v8::ArrayBuffer::Allocator* v8::ArrayBuffer::Allocator::NewDefaultAllocator() {
   return new ArrayBufferAllocator();
@@ -7519,7 +7583,7 @@ std::unique_ptr<v8::BackingStore> v8::ArrayBuffer::NewBackingStore(
 }
 
 std::unique_ptr<v8::BackingStore> v8::ArrayBuffer::NewBackingStore(
-    void* data, size_t byte_length, BackingStoreDeleterCallback deleter,
+    void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
     void* deleter_data) {
   CHECK_LE(byte_length, i::JSArrayBuffer::kMaxByteLength);
   std::unique_ptr<i::BackingStoreBase> backing_store =
@@ -7848,7 +7912,7 @@ std::unique_ptr<v8::BackingStore> v8::SharedArrayBuffer::NewBackingStore(
 }
 
 std::unique_ptr<v8::BackingStore> v8::SharedArrayBuffer::NewBackingStore(
-    void* data, size_t byte_length, BackingStoreDeleterCallback deleter,
+    void* data, size_t byte_length, v8::BackingStore::DeleterCallback deleter,
     void* deleter_data) {
   CHECK_LE(byte_length, i::JSArrayBuffer::kMaxByteLength);
   std::unique_ptr<i::BackingStoreBase> backing_store =
@@ -8328,16 +8392,17 @@ void Isolate::SetHostCleanupFinalizationGroupCallback(
 
 Maybe<bool> FinalizationGroup::Cleanup(
     Local<FinalizationGroup> finalization_group) {
-  i::Handle<i::JSFinalizationGroup> fg = Utils::OpenHandle(*finalization_group);
-  i::Isolate* isolate = fg->native_context().GetIsolate();
-  i::Handle<i::Context> i_context(fg->native_context(), isolate);
+  i::Handle<i::JSFinalizationRegistry> fr =
+      Utils::OpenHandle(*finalization_group);
+  i::Isolate* isolate = fr->native_context().GetIsolate();
+  i::Handle<i::Context> i_context(fr->native_context(), isolate);
   Local<Context> context = Utils::ToLocal(i_context);
   ENTER_V8(isolate, context, FinalizationGroup, Cleanup, Nothing<bool>(),
            i::HandleScope);
-  i::Handle<i::Object> callback(fg->cleanup(), isolate);
-  fg->set_scheduled_for_cleanup(false);
+  i::Handle<i::Object> callback(fr->cleanup(), isolate);
+  fr->set_scheduled_for_cleanup(false);
   has_pending_exception =
-      i::JSFinalizationGroup::Cleanup(isolate, fg, callback).IsNothing();
+      i::JSFinalizationRegistry::Cleanup(isolate, fr, callback).IsNothing();
   RETURN_ON_FAILED_EXECUTION_PRIMITIVE(bool);
   return Just(true);
 }
@@ -8455,6 +8520,8 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
   heap_statistics->total_available_size_ = heap->Available();
   heap_statistics->used_heap_size_ = heap->SizeOfObjects();
+  heap_statistics->total_global_handles_size_ = heap->TotalGlobalHandlesSize();
+  heap_statistics->used_global_handles_size_ = heap->UsedGlobalHandlesSize();
 
 #ifndef V8_SHARED_RO_HEAP
   i::ReadOnlySpace* ro_space = heap->read_only_space();
@@ -8655,10 +8722,10 @@ void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
   isolate->SetPromiseRejectCallback(callback);
 }
 
-void Isolate::RunMicrotasks() {
+void Isolate::PerformMicrotaskCheckpoint() {
   DCHECK_NE(MicrotasksPolicy::kScoped, GetMicrotasksPolicy());
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
-  isolate->default_microtask_queue()->RunMicrotasks(isolate);
+  isolate->default_microtask_queue()->PerformCheckpoint(this);
 }
 
 void Isolate::EnqueueMicrotask(Local<Function> v8_function) {
@@ -9265,6 +9332,34 @@ MaybeLocal<Array> debug::GetInternalProperties(Isolate* v8_isolate,
   return Utils::ToLocal(result);
 }
 
+namespace {
+void CollectPrivateMethodsAndAccessorsFromContext(
+    i::Isolate* isolate, i::Handle<i::Context> context,
+    i::IsStaticFlag is_static_flag, std::vector<Local<Value>>* names_out,
+    std::vector<Local<Value>>* values_out) {
+  i::Handle<i::ScopeInfo> scope_info(context->scope_info(), isolate);
+  int local_count = scope_info->ContextLocalCount();
+  for (int j = 0; j < local_count; ++j) {
+    i::VariableMode mode = scope_info->ContextLocalMode(j);
+    i::IsStaticFlag flag = scope_info->ContextLocalIsStaticFlag(j);
+    if (!i::IsPrivateMethodOrAccessorVariableMode(mode) ||
+        flag != is_static_flag) {
+      continue;
+    }
+
+    i::Handle<i::String> name(scope_info->ContextLocalName(j), isolate);
+    int context_index = scope_info->ContextHeaderLength() + j;
+    i::Handle<i::Object> slot_value(context->get(context_index), isolate);
+    DCHECK_IMPLIES(mode == i::VariableMode::kPrivateMethod,
+                   slot_value->IsJSFunction());
+    DCHECK_IMPLIES(mode != i::VariableMode::kPrivateMethod,
+                   slot_value->IsAccessorPair());
+    names_out->push_back(Utils::ToLocal(name));
+    values_out->push_back(Utils::ToLocal(slot_value));
+  }
+}
+}  // anonymous namespace
+
 bool debug::GetPrivateMembers(Local<Context> context, Local<Object> value,
                               std::vector<Local<Value>>* names_out,
                               std::vector<Local<Value>>* values_out) {
@@ -9285,7 +9380,7 @@ bool debug::GetPrivateMembers(Local<Context> context, Local<Object> value,
                                  i::GetKeysConversion::kConvertToString),
       false);
 
-  // Estimate number of private entries to return in the FixedArray.
+  // Estimate number of private fields and private instance methods/accessors.
   int private_entries_count = 0;
   for (int i = 0; i < keys->length(); ++i) {
     // Exclude the private brand symbols.
@@ -9305,10 +9400,42 @@ bool debug::GetPrivateMembers(Local<Context> context, Local<Object> value,
     }
   }
 
+  // Estimate number of static private methods/accessors for classes.
+  bool has_static_private_methods_or_accessors = false;
+  if (receiver->IsJSFunction()) {
+    i::Handle<i::JSFunction> func(i::JSFunction::cast(*receiver), isolate);
+    i::Handle<i::SharedFunctionInfo> shared(func->shared(), isolate);
+    if (shared->is_class_constructor() &&
+        shared->has_static_private_methods_or_accessors()) {
+      has_static_private_methods_or_accessors = true;
+      i::Handle<i::Context> context(func->context(), isolate);
+      i::Handle<i::ScopeInfo> scope_info(context->scope_info(), isolate);
+      int local_count = scope_info->ContextLocalCount();
+      for (int j = 0; j < local_count; ++j) {
+        i::VariableMode mode = scope_info->ContextLocalMode(j);
+        i::IsStaticFlag is_static_flag =
+            scope_info->ContextLocalIsStaticFlag(j);
+        if (i::IsPrivateMethodOrAccessorVariableMode(mode) &&
+            is_static_flag == i::IsStaticFlag::kStatic) {
+          private_entries_count += local_count;
+          break;
+        }
+      }
+    }
+  }
+
   DCHECK(names_out->empty());
   names_out->reserve(private_entries_count);
   DCHECK(values_out->empty());
   values_out->reserve(private_entries_count);
+
+  if (has_static_private_methods_or_accessors) {
+    i::Handle<i::Context> context(i::JSFunction::cast(*receiver).context(),
+                                  isolate);
+    CollectPrivateMethodsAndAccessorsFromContext(
+        isolate, context, i::IsStaticFlag::kStatic, names_out, values_out);
+  }
+
   for (int i = 0; i < keys->length(); ++i) {
     i::Handle<i::Object> obj_key(keys->get(i), isolate);
     i::Handle<i::Symbol> key(i::Symbol::cast(*obj_key), isolate);
@@ -9320,25 +9447,8 @@ bool debug::GetPrivateMembers(Local<Context> context, Local<Object> value,
     if (key->is_private_brand()) {
       DCHECK(value->IsContext());
       i::Handle<i::Context> context(i::Context::cast(*value), isolate);
-      i::Handle<i::ScopeInfo> scope_info(context->scope_info(), isolate);
-      int local_count = scope_info->ContextLocalCount();
-
-      for (int j = 0; j < local_count; ++j) {
-        i::VariableMode mode = scope_info->ContextLocalMode(j);
-        if (!i::IsPrivateMethodOrAccessorVariableMode(mode)) {
-          continue;
-        }
-
-        i::Handle<i::String> name(scope_info->ContextLocalName(j), isolate);
-        int context_index = scope_info->ContextHeaderLength() + j;
-        i::Handle<i::Object> slot_value(context->get(context_index), isolate);
-        DCHECK_IMPLIES(mode == i::VariableMode::kPrivateMethod,
-                       slot_value->IsJSFunction());
-        DCHECK_IMPLIES(mode != i::VariableMode::kPrivateMethod,
-                       slot_value->IsAccessorPair());
-        names_out->push_back(Utils::ToLocal(name));
-        values_out->push_back(Utils::ToLocal(slot_value));
-      }
+      CollectPrivateMethodsAndAccessorsFromContext(
+          isolate, context, i::IsStaticFlag::kNotStatic, names_out, values_out);
     } else {  // Private fields
       i::Handle<i::String> name(
           i::String::cast(i::Symbol::cast(*key).description()), isolate);
@@ -9397,6 +9507,12 @@ void debug::BreakRightNow(Isolate* v8_isolate) {
   isolate->debug()->HandleDebugBreak(i::kIgnoreIfAllFramesBlackboxed);
 }
 
+void debug::SetTerminateOnResume(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
+  isolate->debug()->SetTerminateOnResume();
+}
+
 bool debug::AllFramesOnStackAreBlackboxed(Isolate* v8_isolate) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8_DO_NOT_USE(isolate);
@@ -9438,7 +9554,7 @@ std::vector<int> debug::Script::LineEnds() const {
 
   i::Isolate* isolate = script->GetIsolate();
   i::HandleScope scope(isolate);
-  i::Script::InitLineEnds(script);
+  i::Script::InitLineEnds(isolate, script);
   CHECK(script->line_ends().IsFixedArray());
   i::Handle<i::FixedArray> line_ends(i::FixedArray::cast(script->line_ends()),
                                      isolate);
@@ -9530,9 +9646,9 @@ bool debug::Script::GetPossibleBreakpoints(
                                                  locations);
   }
 
-  i::Script::InitLineEnds(script);
-  CHECK(script->line_ends().IsFixedArray());
   i::Isolate* isolate = script->GetIsolate();
+  i::Script::InitLineEnds(isolate, script);
+  CHECK(script->line_ends().IsFixedArray());
   i::Handle<i::FixedArray> line_ends =
       i::Handle<i::FixedArray>::cast(i::handle(script->line_ends(), isolate));
   CHECK(line_ends->length());
@@ -9585,7 +9701,7 @@ int debug::Script::GetSourceOffset(const debug::Location& location) const {
     column = std::max(0, column - script->column_offset());
   }
 
-  i::Script::InitLineEnds(script);
+  i::Script::InitLineEnds(script->GetIsolate(), script);
   CHECK(script->line_ends().IsFixedArray());
   i::Handle<i::FixedArray> line_ends = i::Handle<i::FixedArray>::cast(
       i::handle(script->line_ends(), script->GetIsolate()));
@@ -9732,6 +9848,15 @@ uint32_t debug::WasmScript::GetFunctionHash(int function_index) {
                                                function_bytes.length(), 0);
 }
 
+int debug::WasmScript::CodeOffset() const {
+  i::Handle<i::Script> script = Utils::OpenHandle(this);
+  DCHECK_EQ(i::Script::TYPE_WASM, script->type());
+  i::wasm::NativeModule* native_module = script->wasm_native_module();
+  const i::wasm::WasmModule* module = native_module->module();
+
+  return module->code.offset();
+}
+
 debug::Location::Location(int line_number, int column_number)
     : line_number_(line_number),
       column_number_(column_number),
@@ -9797,6 +9922,16 @@ MaybeLocal<UnboundScript> debug::CompileInspectorScript(Isolate* v8_isolate,
   RETURN_ESCAPED(ToApiHandle<UnboundScript>(result));
 }
 
+void debug::TierDownAllModulesPerIsolate(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  isolate->wasm_engine()->TierDownAllModulesPerIsolate(isolate);
+}
+
+void debug::TierUpAllModulesPerIsolate(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  isolate->wasm_engine()->TierUpAllModulesPerIsolate(isolate);
+}
+
 void debug::SetDebugDelegate(Isolate* v8_isolate,
                              debug::DebugDelegate* delegate) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
@@ -9911,7 +10046,7 @@ debug::ConsoleCallArguments::ConsoleCallArguments(
     : v8::FunctionCallbackInfo<v8::Value>(
           nullptr,
           // Drop the first argument (receiver, i.e. the "console" object).
-          args.address_of_arg_at(args.length() > 1 ? 1 : 0),
+          args.length() > 1 ? args.address_of_first_argument() : nullptr,
           args.length() - 1) {}
 
 int debug::GetStackFrameId(v8::Local<v8::StackFrame> frame) {
@@ -10826,6 +10961,34 @@ void EmbedderHeapTracer::ResetHandleInNonTracingGC(
   UNREACHABLE();
 }
 
+const void* CTypeInfo::GetWrapperInfo() const {
+  DCHECK(payload_ & kWrapperTypeInfoMask);
+  return reinterpret_cast<const void*>(payload_ & kWrapperTypeInfoMask);
+}
+
+CFunction::CFunction(const void* address, const CFunctionInfo* type_info)
+    : address_(address), type_info_(type_info) {
+  CHECK_NOT_NULL(address_);
+  CHECK_NOT_NULL(type_info_);
+  for (unsigned int i = 0; i < type_info_->ArgumentCount(); ++i) {
+    if (type_info_->ArgumentInfo(i).IsArray()) {
+      // Array args require an integer passed for their length
+      // as the next argument.
+      DCHECK_LT(i + 1, type_info_->ArgumentCount());
+      switch (type_info_->ArgumentInfo(i + 1).GetType()) {
+        case CTypeInfo::Type::kInt32:
+        case CTypeInfo::Type::kUint32:
+        case CTypeInfo::Type::kInt64:
+        case CTypeInfo::Type::kUint64:
+          break;
+        default:
+          UNREACHABLE();
+          break;
+      }
+    }
+  }
+}
+
 namespace internal {
 
 const size_t HandleScopeImplementer::kEnteredContextsOffset =
@@ -11007,6 +11170,27 @@ void InvokeFunctionCallback(const v8::FunctionCallbackInfo<v8::Value>& info,
   callback(info);
 }
 
+void InvokeFinalizationRegistryCleanupFromTask(
+    Handle<Context> context,
+    Handle<JSFinalizationRegistry> finalization_registry,
+    Handle<Object> callback) {
+  Isolate* isolate = finalization_registry->native_context().GetIsolate();
+  RuntimeCallTimerScope timer(
+      isolate, RuntimeCallCounterId::kFinalizationRegistryCleanupFromTask);
+  // Do not use ENTER_V8 because this is always called from a running
+  // FinalizationRegistryCleanupTask within V8 and we should not log it as an
+  // API call. This method is implemented here to avoid duplication of the
+  // exception handling and microtask running logic in CallDepthScope.
+  if (IsExecutionTerminatingCheck(isolate)) return;
+  Local<v8::Context> api_context = Utils::ToLocal(context);
+  CallDepthScope<true> call_depth_scope(isolate, api_context);
+  VMState<OTHER> state(isolate);
+  if (JSFinalizationRegistry::Cleanup(isolate, finalization_registry, callback)
+          .IsNothing()) {
+    call_depth_scope.Escape();
+  }
+}
+
 // Undefine macros for jumbo build.
 #undef LOG_API
 #undef ENTER_V8_DO_NOT_USE
diff --git a/deps/v8/src/api/api.h b/deps/v8/src/api/api.h
index 004740099c..4c383d3e43 100644
--- a/deps/v8/src/api/api.h
+++ b/deps/v8/src/api/api.h
@@ -26,6 +26,7 @@ namespace v8 {
 
 namespace internal {
 class JSArrayBufferView;
+class JSFinalizationRegistry;
 }  // namespace internal
 
 namespace debug {
@@ -92,7 +93,7 @@ class RegisteredExtension {
   V(Data, Object)                              \
   V(RegExp, JSRegExp)                          \
   V(Object, JSReceiver)                        \
-  V(FinalizationGroup, JSFinalizationGroup)    \
+  V(FinalizationGroup, JSFinalizationRegistry) \
   V(Array, JSArray)                            \
   V(Map, JSMap)                                \
   V(Set, JSSet)                                \
@@ -205,7 +206,7 @@ class Utils {
   static inline Local<BigUint64Array> ToLocalBigUint64Array(
       v8::internal::Handle<v8::internal::JSTypedArray> obj);
   static inline Local<FinalizationGroup> ToLocal(
-      v8::internal::Handle<v8::internal::JSFinalizationGroup> obj);
+      v8::internal::Handle<v8::internal::JSFinalizationRegistry> obj);
 
   static inline Local<SharedArrayBuffer> ToLocalShared(
       v8::internal::Handle<v8::internal::JSArrayBuffer> obj);
@@ -561,6 +562,11 @@ void InvokeAccessorGetterCallback(
 void InvokeFunctionCallback(const v8::FunctionCallbackInfo<v8::Value>& info,
                             v8::FunctionCallback callback);
 
+void InvokeFinalizationRegistryCleanupFromTask(
+    Handle<Context> context,
+    Handle<JSFinalizationRegistry> finalization_registry,
+    Handle<Object> callback);
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/asmjs/asm-js.cc b/deps/v8/src/asmjs/asm-js.cc
index 033efc45b3..5a6846c33f 100644
--- a/deps/v8/src/asmjs/asm-js.cc
+++ b/deps/v8/src/asmjs/asm-js.cc
@@ -132,13 +132,11 @@ void Report(Handle<Script> script, int position, Vector<const char> text,
 
 // Hook to report successful execution of {AsmJs::CompileAsmViaWasm} phase.
 void ReportCompilationSuccess(Handle<Script> script, int position,
-                              double translate_time, double compile_time,
-                              size_t module_size) {
+                              double compile_time, size_t module_size) {
   if (FLAG_suppress_asm_messages || !FLAG_trace_asm_time) return;
   EmbeddedVector<char, 100> text;
-  int length = SNPrintF(
-      text, "success, asm->wasm: %0.3f ms, compile: %0.3f ms, %zu bytes",
-      translate_time, compile_time, module_size);
+  int length = SNPrintF(text, "success, compile time %0.3f ms, %zu bytes",
+                        compile_time, module_size);
   CHECK_NE(-1, length);
   text.Truncate(length);
   Report(script, position, text, MessageTemplate::kAsmJsCompiled,
@@ -195,16 +193,17 @@ class AsmJsCompilationJob final : public UnoptimizedCompilationJob {
         compilation_info_(&zone_, parse_info, literal),
         module_(nullptr),
         asm_offsets_(nullptr),
-        translate_time_(0),
         compile_time_(0),
-        module_source_size_(0),
-        translate_time_micro_(0),
-        translate_zone_size_(0) {}
+        module_source_size_(0) {}
 
  protected:
   Status ExecuteJobImpl() final;
   Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
                          Isolate* isolate) final;
+  Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
+                         OffThreadIsolate* isolate) final {
+    UNREACHABLE();
+  }
 
  private:
   void RecordHistograms(Isolate* isolate);
@@ -216,21 +215,14 @@ class AsmJsCompilationJob final : public UnoptimizedCompilationJob {
   wasm::ZoneBuffer* asm_offsets_;
   wasm::AsmJsParser::StdlibSet stdlib_uses_;
 
-  double translate_time_;   // Time (milliseconds) taken to execute step [1].
   double compile_time_;     // Time (milliseconds) taken to execute step [2].
   int module_source_size_;  // Module source size in bytes.
-  int64_t translate_time_micro_;  // Time (microseconds) taken to translate.
-  size_t translate_zone_size_;
 
   DISALLOW_COPY_AND_ASSIGN(AsmJsCompilationJob);
 };
 
 UnoptimizedCompilationJob::Status AsmJsCompilationJob::ExecuteJobImpl() {
   // Step 1: Translate asm.js module to WebAssembly module.
-  size_t compile_zone_start = compilation_info()->zone()->allocation_size();
-  base::ElapsedTimer translate_timer;
-  translate_timer.Start();
-
   Zone* compile_zone = compilation_info()->zone();
   Zone translate_zone(allocator_, ZONE_NAME);
 
@@ -254,19 +246,8 @@ UnoptimizedCompilationJob::Status AsmJsCompilationJob::ExecuteJobImpl() {
   parser.module_builder()->WriteAsmJsOffsetTable(asm_offsets_);
   stdlib_uses_ = *parser.stdlib_uses();
 
-  size_t compile_zone_size =
-      compilation_info()->zone()->allocation_size() - compile_zone_start;
-  translate_zone_size_ = translate_zone.allocation_size();
-  translate_time_ = translate_timer.Elapsed().InMillisecondsF();
-  translate_time_micro_ = translate_timer.Elapsed().InMicroseconds();
   module_source_size_ = compilation_info()->literal()->end_position() -
                         compilation_info()->literal()->start_position();
-  if (FLAG_trace_asm_parser) {
-    PrintF(
-        "[asm.js translation successful: time=%0.3fms, "
-        "translate_zone=%zuKB, compile_zone+=%zuKB]\n",
-        translate_time_, translate_zone_size_ / KB, compile_zone_size / KB);
-  }
   return SUCCEEDED;
 }
 
@@ -297,26 +278,12 @@ UnoptimizedCompilationJob::Status AsmJsCompilationJob::FinalizeJobImpl(
   RecordHistograms(isolate);
   ReportCompilationSuccess(handle(Script::cast(shared_info->script()), isolate),
                            compilation_info()->literal()->position(),
-                           translate_time_, compile_time_, module_->size());
+                           compile_time_, module_->size());
   return SUCCEEDED;
 }
 
 void AsmJsCompilationJob::RecordHistograms(Isolate* isolate) {
-  Counters* counters = isolate->counters();
-  counters->asm_wasm_translation_time()->AddSample(
-      static_cast<int>(translate_time_micro_));
-  counters->asm_wasm_translation_peak_memory_bytes()->AddSample(
-      static_cast<int>(translate_zone_size_));
-  counters->asm_module_size_bytes()->AddSample(module_source_size_);
-  // translation_throughput is not exact (assumes MB == 1000000). But that is ok
-  // since the metric is stored in buckets that lose some precision anyways.
-  int translation_throughput =
-      translate_time_micro_ != 0
-          ? static_cast<int>(static_cast<int64_t>(module_source_size_) /
-                             translate_time_micro_)
-          : 0;
-  counters->asm_wasm_translation_throughput()->AddSample(
-      translation_throughput);
+  isolate->counters()->asm_module_size_bytes()->AddSample(module_source_size_);
 }
 
 std::unique_ptr<UnoptimizedCompilationJob> AsmJs::NewCompilationJob(
@@ -330,7 +297,7 @@ inline bool IsValidAsmjsMemorySize(size_t size) {
   // Enforce asm.js spec minimum size.
   if (size < (1u << 12u)) return false;
   // Enforce engine-limited and flag-limited maximum allocation size.
-  if (size > wasm::max_mem_pages() * uint64_t{wasm::kWasmPageSize}) {
+  if (size > wasm::max_initial_mem_pages() * uint64_t{wasm::kWasmPageSize}) {
     return false;
   }
   // Enforce power-of-2 sizes for 2^12 - 2^24.
@@ -441,9 +408,12 @@ MaybeHandle<Object> AsmJs::InstantiateAsmWasm(Isolate* isolate,
     return single_function;
   }
 
-  Handle<String> exports_name =
-      isolate->factory()->InternalizeUtf8String("exports");
-  return Object::GetProperty(isolate, instance, exports_name);
+  // Here we rely on the fact that the exports object is eagerly created.
+  // The following check is a weak indicator for that. If this ever changes,
+  // then we'll have to call the "exports" getter, and be careful about
+  // handling possible stack overflow exceptions.
+  DCHECK(instance->exports_object().IsJSObject());
+  return handle(instance->exports_object(), isolate);
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/ast/ast-traversal-visitor.h b/deps/v8/src/ast/ast-traversal-visitor.h
index af4b49c6c3..8a1f8b2f16 100644
--- a/deps/v8/src/ast/ast-traversal-visitor.h
+++ b/deps/v8/src/ast/ast-traversal-visitor.h
@@ -295,13 +295,6 @@ void AstTraversalVisitor<Subclass>::VisitNativeFunctionLiteral(
 }
 
 template <class Subclass>
-void AstTraversalVisitor<Subclass>::VisitDoExpression(DoExpression* expr) {
-  PROCESS_EXPRESSION(expr);
-  RECURSE(VisitBlock(expr->block()));
-  RECURSE(VisitVariableProxy(expr->result()));
-}
-
-template <class Subclass>
 void AstTraversalVisitor<Subclass>::VisitConditional(Conditional* expr) {
   PROCESS_EXPRESSION(expr);
   RECURSE_EXPRESSION(Visit(expr->condition()));
@@ -519,15 +512,6 @@ void AstTraversalVisitor<Subclass>::VisitSpread(Spread* expr) {
 }
 
 template <class Subclass>
-void AstTraversalVisitor<Subclass>::VisitStoreInArrayLiteral(
-    StoreInArrayLiteral* expr) {
-  PROCESS_EXPRESSION(expr);
-  RECURSE_EXPRESSION(Visit(expr->array()));
-  RECURSE_EXPRESSION(Visit(expr->index()));
-  RECURSE_EXPRESSION(Visit(expr->value()));
-}
-
-template <class Subclass>
 void AstTraversalVisitor<Subclass>::VisitEmptyParentheses(
     EmptyParentheses* expr) {
   PROCESS_EXPRESSION(expr);
diff --git a/deps/v8/src/ast/ast-value-factory.cc b/deps/v8/src/ast/ast-value-factory.cc
index fd61cd6808..7e1be44da1 100644
--- a/deps/v8/src/ast/ast-value-factory.cc
+++ b/deps/v8/src/ast/ast-value-factory.cc
@@ -28,6 +28,7 @@
 #include "src/ast/ast-value-factory.h"
 
 #include "src/common/globals.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/heap/factory-inl.h"
 #include "src/heap/off-thread-factory-inl.h"
 #include "src/objects/objects-inl.h"
@@ -57,24 +58,24 @@ class OneByteStringStream {
 
 }  // namespace
 
-void AstRawString::Internalize(Factory* factory) {
+void AstRawString::Internalize(Isolate* isolate) {
   DCHECK(!has_string_);
   if (literal_bytes_.length() == 0) {
-    set_string(factory->empty_string());
+    set_string(isolate->factory()->empty_string());
   } else if (is_one_byte()) {
     OneByteStringKey key(hash_field_, literal_bytes_);
-    set_string(factory->InternalizeStringWithKey(&key));
+    set_string(isolate->factory()->InternalizeStringWithKey(&key));
   } else {
     TwoByteStringKey key(hash_field_,
                          Vector<const uint16_t>::cast(literal_bytes_));
-    set_string(factory->InternalizeStringWithKey(&key));
+    set_string(isolate->factory()->InternalizeStringWithKey(&key));
   }
 }
 
-void AstRawString::Internalize(OffThreadFactory* factory) {
+void AstRawString::Internalize(OffThreadIsolate* isolate) {
   DCHECK(!has_string_);
   if (literal_bytes_.length() == 0) {
-    set_string(factory->empty_string());
+    set_string(isolate->factory()->empty_string());
     return;
   }
 
@@ -82,28 +83,30 @@ void AstRawString::Internalize(OffThreadFactory* factory) {
   // construction and don't have access to the main thread string table yet, so
   // we just unconditionally create strings and will internalize them properly
   // during merging.
-  OffThreadHandle<SeqString> string;
+  Handle<SeqString> string;
   if (is_one_byte()) {
-    string = factory->NewOneByteInternalizedString(
+    string = isolate->factory()->NewOneByteInternalizedString(
         Vector<const uint8_t>::cast(literal_bytes_), hash_field());
   } else {
-    string = factory->NewTwoByteInternalizedString(
+    string = isolate->factory()->NewTwoByteInternalizedString(
         Vector<const uc16>::cast(literal_bytes_), hash_field());
   }
   set_string(string);
 }
 
 bool AstRawString::AsArrayIndex(uint32_t* index) const {
-  // The StringHasher will set up the hash in such a way that we can use it to
-  // figure out whether the string is convertible to an array index.
-  if ((hash_field_ & Name::kIsNotArrayIndexMask) != 0) return false;
+  // The StringHasher will set up the hash. Bail out early if we know it
+  // can't be convertible to an array index.
+  if ((hash_field_ & Name::kIsNotIntegerIndexMask) != 0) return false;
   if (length() <= Name::kMaxCachedArrayIndexLength) {
     *index = Name::ArrayIndexValueBits::decode(hash_field_);
-  } else {
-    OneByteStringStream stream(literal_bytes_);
-    CHECK(StringToIndex(&stream, index));
+    return true;
   }
-  return true;
+  // Might be an index, but too big to cache it. Do the slow conversion. This
+  // might fail if the string is outside uint32_t (but within "safe integer")
+  // range.
+  OneByteStringStream stream(literal_bytes_);
+  return StringToIndex(&stream, index);
 }
 
 bool AstRawString::IsIntegerIndex() const {
@@ -159,37 +162,91 @@ bool AstRawString::Compare(void* a, void* b) {
   }
 }
 
-template <typename Factory>
-void AstConsString::Internalize(Factory* factory) {
+template <typename LocalIsolate>
+Handle<String> AstConsString::Allocate(LocalIsolate* isolate) const {
+  DCHECK(string_.is_null());
+
   if (IsEmpty()) {
-    set_string(factory->empty_string());
-    return;
+    return isolate->factory()->empty_string();
   }
-  // AstRawStrings are internalized before AstConsStrings, so
+  // AstRawStrings are internalized before AstConsStrings are allocated, so
   // AstRawString::string() will just work.
-  FactoryHandle<Factory, String> tmp(segment_.string->string().get<Factory>());
+  Handle<String> tmp = segment_.string->string();
   for (AstConsString::Segment* current = segment_.next; current != nullptr;
        current = current->next) {
-    tmp =
-        factory
-            ->NewConsString(
-                current->string->string().get<Factory>(), tmp,
-                // TODO(leszeks): This is to avoid memory regressions while this
-                // path is under development -- the off-thread factory doesn't
-                // support young allocations. Figure out a way to avoid memory
-                // regressions related to ConsStrings in the off-thread path.
-                std::is_same<Factory, OffThreadFactory>::value
-                    ? AllocationType::kOld
-                    : AllocationType::kYoung)
+    tmp = isolate->factory()
+              ->NewConsString(current->string->string(), tmp,
+                              AllocationType::kOld)
+              .ToHandleChecked();
+  }
+  return tmp;
+}
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<String> AstConsString::Allocate<Isolate>(Isolate* isolate) const;
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<String> AstConsString::Allocate<OffThreadIsolate>(
+        OffThreadIsolate* isolate) const;
+
+template <typename LocalIsolate>
+Handle<String> AstConsString::AllocateFlat(LocalIsolate* isolate) const {
+  if (IsEmpty()) {
+    return isolate->factory()->empty_string();
+  }
+  if (!segment_.next) {
+    return segment_.string->string();
+  }
+
+  int result_length = 0;
+  bool is_one_byte = true;
+  for (const AstConsString::Segment* current = &segment_; current != nullptr;
+       current = current->next) {
+    result_length += current->string->length();
+    is_one_byte = is_one_byte && current->string->is_one_byte();
+  }
+
+  if (is_one_byte) {
+    Handle<SeqOneByteString> result =
+        isolate->factory()
+            ->NewRawOneByteString(result_length, AllocationType::kOld)
             .ToHandleChecked();
+    DisallowHeapAllocation no_gc;
+    uint8_t* dest = result->GetChars(no_gc) + result_length;
+    for (const AstConsString::Segment* current = &segment_; current != nullptr;
+         current = current->next) {
+      int length = current->string->length();
+      dest -= length;
+      CopyChars(dest, current->string->raw_data(), length);
+    }
+    DCHECK_EQ(dest, result->GetChars(no_gc));
+    return result;
+  }
+
+  Handle<SeqTwoByteString> result =
+      isolate->factory()
+          ->NewRawTwoByteString(result_length, AllocationType::kOld)
+          .ToHandleChecked();
+  DisallowHeapAllocation no_gc;
+  uint16_t* dest = result->GetChars(no_gc) + result_length;
+  for (const AstConsString::Segment* current = &segment_; current != nullptr;
+       current = current->next) {
+    int length = current->string->length();
+    dest -= length;
+    if (current->string->is_one_byte()) {
+      CopyChars(dest, current->string->raw_data(), length);
+    } else {
+      CopyChars(dest,
+                reinterpret_cast<const uint16_t*>(current->string->raw_data()),
+                length);
+    }
   }
-  set_string(tmp);
+  DCHECK_EQ(dest, result->GetChars(no_gc));
+  return result;
 }
-template EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) void AstConsString::Internalize<Factory>(Factory*
-                                                                    factory);
-template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void AstConsString::
-    Internalize<OffThreadFactory>(OffThreadFactory* factory);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<String> AstConsString::AllocateFlat<Isolate>(Isolate* isolate) const;
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<String> AstConsString::AllocateFlat<OffThreadIsolate>(
+        OffThreadIsolate* isolate) const;
 
 std::forward_list<const AstRawString*> AstConsString::ToRawStrings() const {
   std::forward_list<const AstRawString*> result;
@@ -275,10 +332,7 @@ const AstRawString* AstValueFactory::CloneFromOtherFactory(
 }
 
 AstConsString* AstValueFactory::NewConsString() {
-  AstConsString* new_string = new (zone_) AstConsString;
-  DCHECK_NOT_NULL(new_string);
-  AddConsString(new_string);
-  return new_string;
+  return new (zone_) AstConsString;
 }
 
 AstConsString* AstValueFactory::NewConsString(const AstRawString* str) {
@@ -290,30 +344,23 @@ AstConsString* AstValueFactory::NewConsString(const AstRawString* str1,
   return NewConsString()->AddString(zone_, str1)->AddString(zone_, str2);
 }
 
-template <typename Factory>
-void AstValueFactory::Internalize(Factory* factory) {
+template <typename LocalIsolate>
+void AstValueFactory::Internalize(LocalIsolate* isolate) {
   // Strings need to be internalized before values, because values refer to
   // strings.
   for (AstRawString* current = strings_; current != nullptr;) {
     AstRawString* next = current->next();
-    current->Internalize(factory);
-    current = next;
-  }
-
-  // AstConsStrings refer to AstRawStrings.
-  for (AstConsString* current = cons_strings_; current != nullptr;) {
-    AstConsString* next = current->next();
-    current->Internalize(factory);
+    current->Internalize(isolate);
     current = next;
   }
 
   ResetStrings();
 }
 template EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) void AstValueFactory::Internalize<Factory>(Factory*
-                                                                      factory);
+    V8_EXPORT_PRIVATE) void AstValueFactory::Internalize<Isolate>(Isolate*
+                                                                      isolate);
 template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void AstValueFactory::
-    Internalize<OffThreadFactory>(OffThreadFactory* factory);
+    Internalize<OffThreadIsolate>(OffThreadIsolate* isolate);
 
 AstRawString* AstValueFactory::GetString(uint32_t hash_field, bool is_one_byte,
                                          Vector<const byte> literal_bytes) {
diff --git a/deps/v8/src/ast/ast-value-factory.h b/deps/v8/src/ast/ast-value-factory.h
index 9c53f0a8f8..dce9de4069 100644
--- a/deps/v8/src/ast/ast-value-factory.h
+++ b/deps/v8/src/ast/ast-value-factory.h
@@ -32,9 +32,7 @@
 
 #include "src/base/hashmap.h"
 #include "src/common/globals.h"
-#include "src/execution/isolate.h"
 #include "src/heap/factory.h"
-#include "src/heap/off-thread-factory.h"
 #include "src/numbers/conversions.h"
 
 // Ast(Raw|Cons)String and AstValueFactory are for storing strings and
@@ -45,6 +43,9 @@
 namespace v8 {
 namespace internal {
 
+class Isolate;
+class OffThreadIsolate;
+
 class AstRawString final : public ZoneObject {
  public:
   bool IsEmpty() const { return literal_bytes_.length() == 0; }
@@ -57,8 +58,8 @@ class AstRawString final : public ZoneObject {
   V8_EXPORT_PRIVATE bool IsOneByteEqualTo(const char* data) const;
   uint16_t FirstCharacter() const;
 
-  void Internalize(Factory* factory);
-  void Internalize(OffThreadFactory* factory);
+  void Internalize(Isolate* isolate);
+  void Internalize(OffThreadIsolate* isolate);
 
   // Access the physical representation:
   bool is_one_byte() const { return is_one_byte_; }
@@ -70,7 +71,7 @@ class AstRawString final : public ZoneObject {
   uint32_t Hash() const { return hash_field_ >> Name::kHashShift; }
 
   // This function can be called after internalizing.
-  V8_INLINE HandleOrOffThreadHandle<String> string() const {
+  V8_INLINE Handle<String> string() const {
     DCHECK(has_string_);
     return string_;
   }
@@ -97,7 +98,7 @@ class AstRawString final : public ZoneObject {
     return &next_;
   }
 
-  void set_string(HandleOrOffThreadHandle<String> string) {
+  void set_string(Handle<String> string) {
     DCHECK(!string.is_null());
     DCHECK(!has_string_);
     string_ = string;
@@ -108,7 +109,7 @@ class AstRawString final : public ZoneObject {
 
   union {
     AstRawString* next_;
-    HandleOrOffThreadHandle<String> string_;
+    Handle<String> string_;
   };
 
   Vector<const byte> literal_bytes_;  // Memory owned by Zone.
@@ -143,53 +144,42 @@ class AstConsString final : public ZoneObject {
     return segment_.string == nullptr;
   }
 
-  template <typename Factory>
-  void Internalize(Factory* factory);
-
-  // This function can be called after internalizing.
-  V8_INLINE HandleOrOffThreadHandle<String> string() const {
-    DCHECK(has_string_);
+  template <typename LocalIsolate>
+  Handle<String> GetString(LocalIsolate* isolate) {
+    if (string_.is_null()) {
+      string_ = Allocate(isolate);
+    }
     return string_;
   }
 
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<String> AllocateFlat(LocalIsolate* isolate) const;
+
   std::forward_list<const AstRawString*> ToRawStrings() const;
 
  private:
   friend class AstValueFactory;
 
-  AstConsString() : next_(nullptr), segment_({nullptr, nullptr}) {}
-
-  AstConsString* next() const { return next_; }
-  AstConsString** next_location() { return &next_; }
+  AstConsString() : string_(), segment_({nullptr, nullptr}) {}
 
-  void set_string(HandleOrOffThreadHandle<String> string) {
-    DCHECK(!string.is_null());
-    DCHECK(!has_string_);
-    string_ = string;
-#ifdef DEBUG
-    has_string_ = true;
-#endif
-  }
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<String> Allocate(LocalIsolate* isolate) const;
 
-  // {string_} is stored as Address* instead of a Handle<String> so it can be
-  // stored in a union with {next_}.
-  union {
-    AstConsString* next_;
-    HandleOrOffThreadHandle<String> string_;
-  };
+  Handle<String> string_;
 
+  // A linked list of AstRawStrings of the contents of this AstConsString.
+  // This list has several properties:
+  //
+  //   * For empty strings the string pointer is null,
+  //   * Appended raw strings are added to the head of the list, so they are in
+  //     reverse order
   struct Segment {
     const AstRawString* string;
     AstConsString::Segment* next;
   };
   Segment segment_;
-
-#ifdef DEBUG
-  // (Debug-only:) Verify the object life-cylce: Some functions may only be
-  // called after internalization (that is, after a v8::internal::String has
-  // been set); some only before.
-  bool has_string_ = false;
-#endif
 };
 
 enum class AstSymbol : uint8_t { kHomeObjectSymbol };
@@ -294,8 +284,6 @@ class AstValueFactory {
       : string_table_(string_constants->string_table()),
         strings_(nullptr),
         strings_end_(&strings_),
-        cons_strings_(nullptr),
-        cons_strings_end_(&cons_strings_),
         string_constants_(string_constants),
         empty_cons_string_(nullptr),
         zone_(zone),
@@ -329,8 +317,8 @@ class AstValueFactory {
   V8_EXPORT_PRIVATE AstConsString* NewConsString(const AstRawString* str1,
                                                  const AstRawString* str2);
 
-  template <typename Factory>
-  void Internalize(Factory* factory);
+  template <typename LocalIsolate>
+  void Internalize(LocalIsolate* isolate);
 
 #define F(name, str)                           \
   const AstRawString* name##_string() const {  \
@@ -338,7 +326,7 @@ class AstValueFactory {
   }
   AST_STRING_CONSTANTS(F)
 #undef F
-  const AstConsString* empty_cons_string() const { return empty_cons_string_; }
+  AstConsString* empty_cons_string() const { return empty_cons_string_; }
 
  private:
   AstRawString* AddString(AstRawString* string) {
@@ -346,16 +334,9 @@ class AstValueFactory {
     strings_end_ = string->next_location();
     return string;
   }
-  AstConsString* AddConsString(AstConsString* string) {
-    *cons_strings_end_ = string;
-    cons_strings_end_ = string->next_location();
-    return string;
-  }
   void ResetStrings() {
     strings_ = nullptr;
     strings_end_ = &strings_;
-    cons_strings_ = nullptr;
-    cons_strings_end_ = &cons_strings_;
   }
   V8_EXPORT_PRIVATE AstRawString* GetOneByteStringInternal(
       Vector<const uint8_t> literal);
@@ -366,16 +347,13 @@ class AstValueFactory {
   // All strings are copied here, one after another (no zeroes inbetween).
   base::CustomMatcherHashMap string_table_;
 
-  // We need to keep track of strings_ in order since cons strings require their
-  // members to be internalized first.
   AstRawString* strings_;
   AstRawString** strings_end_;
-  AstConsString* cons_strings_;
-  AstConsString** cons_strings_end_;
 
   // Holds constant string values which are shared across the isolate.
   const AstStringConstants* string_constants_;
-  const AstConsString* empty_cons_string_;
+
+  AstConsString* empty_cons_string_;
 
   // Caches one character lowercase strings (for minified code).
   static const int kMaxOneCharStringValue = 128;
@@ -387,12 +365,12 @@ class AstValueFactory {
 };
 
 extern template EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) void AstValueFactory::Internalize<Factory>(Factory*
-                                                                      factory);
+    V8_EXPORT_PRIVATE) void AstValueFactory::Internalize<Isolate>(Isolate*
+                                                                      isolate);
 
 extern template EXPORT_TEMPLATE_DECLARE(
     V8_EXPORT_PRIVATE) void AstValueFactory::
-    Internalize<OffThreadFactory>(OffThreadFactory* factory);
+    Internalize<OffThreadIsolate>(OffThreadIsolate* isolate);
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/ast/ast.cc b/deps/v8/src/ast/ast.cc
index 12c3aa981f..651508b677 100644
--- a/deps/v8/src/ast/ast.cc
+++ b/deps/v8/src/ast/ast.cc
@@ -10,9 +10,12 @@
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopes.h"
 #include "src/base/hashmap.h"
+#include "src/base/logging.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/builtins/builtins.h"
 #include "src/common/assert-scope.h"
+#include "src/execution/off-thread-isolate.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/numbers/conversions-inl.h"
 #include "src/numbers/double.h"
 #include "src/objects/contexts.h"
@@ -57,7 +60,6 @@ void AstNode::Print(Isolate* isolate) {
   AstPrinter::PrintOut(isolate, this);
 }
 
-
 #endif  // DEBUG
 
 #define RETURN_NODE(Node) \
@@ -202,8 +204,7 @@ void FunctionLiteral::set_inferred_name(Handle<String> inferred_name) {
   scope()->set_has_inferred_function_name(true);
 }
 
-void FunctionLiteral::set_raw_inferred_name(
-    const AstConsString* raw_inferred_name) {
+void FunctionLiteral::set_raw_inferred_name(AstConsString* raw_inferred_name) {
   DCHECK_NOT_NULL(raw_inferred_name);
   raw_inferred_name_ = raw_inferred_name;
   DCHECK(inferred_name_.is_null());
@@ -233,11 +234,7 @@ int FunctionLiteral::start_position() const {
   return scope()->start_position();
 }
 
-
-int FunctionLiteral::end_position() const {
-  return scope()->end_position();
-}
-
+int FunctionLiteral::end_position() const { return scope()->end_position(); }
 
 LanguageMode FunctionLiteral::language_mode() const {
   return scope()->language_mode();
@@ -281,17 +278,6 @@ std::unique_ptr<char[]> FunctionLiteral::GetDebugName() const {
   return result;
 }
 
-bool FunctionLiteral::requires_brand_initialization() const {
-  Scope* outer = scope_->outer_scope();
-
-  // If there are no variables declared in the outer scope other than
-  // the class name variable, the outer class scope may be elided when
-  // the function is deserialized after preparsing.
-  if (!outer->is_class_scope()) return false;
-
-  return outer->AsClassScope()->brand() != nullptr;
-}
-
 bool FunctionLiteral::private_name_lookup_skips_outer_class() const {
   return scope()->private_name_lookup_skips_outer_class();
 }
@@ -339,7 +325,6 @@ bool ObjectLiteral::Property::IsCompileTimeValue() const {
          (kind_ == MATERIALIZED_LITERAL && value_->IsCompileTimeValue());
 }
 
-
 void ObjectLiteral::Property::set_emit_store(bool emit_store) {
   emit_store_ = emit_store;
 }
@@ -473,7 +458,8 @@ int ObjectLiteral::InitDepthAndFlags() {
   return depth_acc;
 }
 
-void ObjectLiteral::BuildBoilerplateDescription(Isolate* isolate) {
+template <typename LocalIsolate>
+void ObjectLiteral::BuildBoilerplateDescription(LocalIsolate* isolate) {
   if (!boilerplate_description_.is_null()) return;
 
   int index_keys = 0;
@@ -518,9 +504,10 @@ void ObjectLiteral::BuildBoilerplateDescription(Isolate* isolate) {
     uint32_t element_index = 0;
     Handle<Object> key =
         key_literal->AsArrayIndex(&element_index)
-            ? isolate->factory()->NewNumberFromUint(element_index)
-            : Handle<Object>::cast(
-                  key_literal->AsRawPropertyName()->string().get<Factory>());
+            ? isolate->factory()
+                  ->template NewNumberFromUint<AllocationType::kOld>(
+                      element_index)
+            : Handle<Object>::cast(key_literal->AsRawPropertyName()->string());
 
     Handle<Object> value = GetBoilerplateValue(property->value(), isolate);
 
@@ -532,6 +519,10 @@ void ObjectLiteral::BuildBoilerplateDescription(Isolate* isolate) {
 
   boilerplate_description_ = boilerplate_description;
 }
+template EXPORT_TEMPLATE_DEFINE(V8_BASE_EXPORT) void ObjectLiteral::
+    BuildBoilerplateDescription(Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_BASE_EXPORT) void ObjectLiteral::
+    BuildBoilerplateDescription(OffThreadIsolate* isolate);
 
 bool ObjectLiteral::IsFastCloningSupported() const {
   // The CreateShallowObjectLiteratal builtin doesn't copy elements, and object
@@ -622,7 +613,8 @@ int ArrayLiteral::InitDepthAndFlags() {
   return depth_acc;
 }
 
-void ArrayLiteral::BuildBoilerplateDescription(Isolate* isolate) {
+template <typename LocalIsolate>
+void ArrayLiteral::BuildBoilerplateDescription(LocalIsolate* isolate) {
   if (!boilerplate_description_.is_null()) return;
 
   int constants_length =
@@ -632,9 +624,11 @@ void ArrayLiteral::BuildBoilerplateDescription(Isolate* isolate) {
 
   Handle<FixedArrayBase> elements;
   if (use_doubles) {
-    elements = isolate->factory()->NewFixedDoubleArray(constants_length);
+    elements = isolate->factory()->NewFixedDoubleArray(constants_length,
+                                                       AllocationType::kOld);
   } else {
-    elements = isolate->factory()->NewFixedArrayWithHoles(constants_length);
+    elements = isolate->factory()->NewFixedArrayWithHoles(constants_length,
+                                                          AllocationType::kOld);
   }
 
   // Fill in the literals.
@@ -664,7 +658,7 @@ void ArrayLiteral::BuildBoilerplateDescription(Isolate* isolate) {
       }
 
       // New handle scope here, needs to be after BuildContants().
-      HandleScope scope(isolate);
+      typename LocalIsolate::HandleScopeType scope(isolate);
 
       Object boilerplate_value = *GetBoilerplateValue(element, isolate);
       // We shouldn't allocate after creating the boilerplate value.
@@ -679,14 +673,15 @@ void ArrayLiteral::BuildBoilerplateDescription(Isolate* isolate) {
         boilerplate_value = Smi::zero();
       }
 
-      DCHECK_EQ(boilerplate_descriptor_kind(),
-                GetMoreGeneralElementsKind(
-                    boilerplate_descriptor_kind(),
-                    boilerplate_value.OptimalElementsKind(isolate)));
+      DCHECK_EQ(
+          boilerplate_descriptor_kind(),
+          GetMoreGeneralElementsKind(boilerplate_descriptor_kind(),
+                                     boilerplate_value.OptimalElementsKind(
+                                         GetIsolateForPtrCompr(*elements))));
 
-      Handle<FixedArray>::cast(elements)->set(array_index, boilerplate_value);
+      FixedArray::cast(*elements).set(array_index, boilerplate_value);
     }
-  }
+  }  // namespace internal
 
   // Simple and shallow arrays can be lazily copied, we transform the
   // elements array to a copy-on-write array.
@@ -698,6 +693,11 @@ void ArrayLiteral::BuildBoilerplateDescription(Isolate* isolate) {
   boilerplate_description_ =
       isolate->factory()->NewArrayBoilerplateDescription(kind, elements);
 }
+template EXPORT_TEMPLATE_DEFINE(
+    V8_BASE_EXPORT) void ArrayLiteral::BuildBoilerplateDescription(Isolate*
+                                                                       isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_BASE_EXPORT) void ArrayLiteral::
+    BuildBoilerplateDescription(OffThreadIsolate* isolate);
 
 bool ArrayLiteral::IsFastCloningSupported() const {
   return depth() <= 1 &&
@@ -712,8 +712,9 @@ bool MaterializedLiteral::IsSimple() const {
   return false;
 }
 
+template <typename LocalIsolate>
 Handle<Object> MaterializedLiteral::GetBoilerplateValue(Expression* expression,
-                                                        Isolate* isolate) {
+                                                        LocalIsolate* isolate) {
   if (expression->IsLiteral()) {
     return expression->AsLiteral()->BuildValue(isolate);
   }
@@ -731,6 +732,12 @@ Handle<Object> MaterializedLiteral::GetBoilerplateValue(Expression* expression,
   }
   return isolate->factory()->uninitialized_value();
 }
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Object> MaterializedLiteral::GetBoilerplateValue(
+        Expression* expression, Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Object> MaterializedLiteral::GetBoilerplateValue(
+        Expression* expression, OffThreadIsolate* isolate);
 
 int MaterializedLiteral::InitDepthAndFlags() {
   if (IsArrayLiteral()) return AsArrayLiteral()->InitDepthAndFlags();
@@ -750,7 +757,8 @@ bool MaterializedLiteral::NeedsInitialAllocationSite() {
   return false;
 }
 
-void MaterializedLiteral::BuildConstants(Isolate* isolate) {
+template <typename LocalIsolate>
+void MaterializedLiteral::BuildConstants(LocalIsolate* isolate) {
   if (IsArrayLiteral()) {
     AsArrayLiteral()->BuildBoilerplateDescription(isolate);
     return;
@@ -761,19 +769,30 @@ void MaterializedLiteral::BuildConstants(Isolate* isolate) {
   }
   DCHECK(IsRegExpLiteral());
 }
+template EXPORT_TEMPLATE_DEFINE(
+    V8_BASE_EXPORT) void MaterializedLiteral::BuildConstants(Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(
+    V8_BASE_EXPORT) void MaterializedLiteral::BuildConstants(OffThreadIsolate*
+                                                                 isolate);
 
+template <typename LocalIsolate>
 Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
-    Isolate* isolate) {
+    LocalIsolate* isolate) {
   Handle<FixedArray> raw_strings = isolate->factory()->NewFixedArray(
       this->raw_strings()->length(), AllocationType::kOld);
   bool raw_and_cooked_match = true;
   for (int i = 0; i < raw_strings->length(); ++i) {
-    if (this->cooked_strings()->at(i) == nullptr ||
-        *this->raw_strings()->at(i)->string().get<Factory>() !=
-            *this->cooked_strings()->at(i)->string().get<Factory>()) {
+    if (this->raw_strings()->at(i) != this->cooked_strings()->at(i)) {
+      // If the AstRawStrings don't match, then neither should the allocated
+      // Strings, since the AstValueFactory should have deduplicated them
+      // already.
+      DCHECK_IMPLIES(this->cooked_strings()->at(i) != nullptr,
+                     *this->cooked_strings()->at(i)->string() !=
+                         *this->raw_strings()->at(i)->string());
+
       raw_and_cooked_match = false;
     }
-    raw_strings->set(i, *this->raw_strings()->at(i)->string().get<Factory>());
+    raw_strings->set(i, *this->raw_strings()->at(i)->string());
   }
   Handle<FixedArray> cooked_strings = raw_strings;
   if (!raw_and_cooked_match) {
@@ -781,8 +800,7 @@ Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
         this->cooked_strings()->length(), AllocationType::kOld);
     for (int i = 0; i < cooked_strings->length(); ++i) {
       if (this->cooked_strings()->at(i) != nullptr) {
-        cooked_strings->set(
-            i, *this->cooked_strings()->at(i)->string().get<Factory>());
+        cooked_strings->set(i, *this->cooked_strings()->at(i)->string());
       } else {
         cooked_strings->set(i, ReadOnlyRoots(isolate).undefined_value());
       }
@@ -791,6 +809,12 @@ Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
   return isolate->factory()->NewTemplateObjectDescription(raw_strings,
                                                           cooked_strings);
 }
+template EXPORT_TEMPLATE_DEFINE(V8_BASE_EXPORT)
+    Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
+        Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_BASE_EXPORT)
+    Handle<TemplateObjectDescription> GetTemplateObject::GetOrBuildDescription(
+        OffThreadIsolate* isolate);
 
 static bool IsCommutativeOperationWithSmiLiteral(Token::Value op) {
   // Add is not commutative due to potential for string addition.
@@ -839,20 +863,16 @@ bool CompareOperation::IsLiteralCompareTypeof(Expression** expr,
          MatchLiteralCompareTypeof(right_, op(), left_, expr, literal);
 }
 
-
 static bool IsVoidOfLiteral(Expression* expr) {
   UnaryOperation* maybe_unary = expr->AsUnaryOperation();
   return maybe_unary != nullptr && maybe_unary->op() == Token::VOID &&
          maybe_unary->expression()->IsLiteral();
 }
 
-
 // Check for the pattern: void <literal> equals <expression> or
 // undefined equals <expression>
-static bool MatchLiteralCompareUndefined(Expression* left,
-                                         Token::Value op,
-                                         Expression* right,
-                                         Expression** expr) {
+static bool MatchLiteralCompareUndefined(Expression* left, Token::Value op,
+                                         Expression* right, Expression** expr) {
   if (IsVoidOfLiteral(left) && Token::IsEqualityOp(op)) {
     *expr = right;
     return true;
@@ -870,10 +890,8 @@ bool CompareOperation::IsLiteralCompareUndefined(Expression** expr) {
 }
 
 // Check for the pattern: null equals <expression>
-static bool MatchLiteralCompareNull(Expression* left,
-                                    Token::Value op,
-                                    Expression* right,
-                                    Expression** expr) {
+static bool MatchLiteralCompareNull(Expression* left, Token::Value op,
+                                    Expression* right, Expression** expr) {
   if (left->IsNullLiteral() && Token::IsEqualityOp(op)) {
     *expr = right;
     return true;
@@ -960,14 +978,16 @@ bool Literal::AsArrayIndex(uint32_t* value) const {
   return ToUint32(value) && *value != kMaxUInt32;
 }
 
-Handle<Object> Literal::BuildValue(Isolate* isolate) const {
+template <typename LocalIsolate>
+Handle<Object> Literal::BuildValue(LocalIsolate* isolate) const {
   switch (type()) {
     case kSmi:
       return handle(Smi::FromInt(smi_), isolate);
     case kHeapNumber:
-      return isolate->factory()->NewNumber<AllocationType::kOld>(number_);
+      return isolate->factory()->template NewNumber<AllocationType::kOld>(
+          number_);
     case kString:
-      return string_->string().get<Factory>();
+      return string_->string();
     case kSymbol:
       return isolate->factory()->home_object_symbol();
     case kBoolean:
@@ -985,6 +1005,10 @@ Handle<Object> Literal::BuildValue(Isolate* isolate) const {
   }
   UNREACHABLE();
 }
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Object> Literal::BuildValue(Isolate* isolate) const;
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Object> Literal::BuildValue(OffThreadIsolate* isolate) const;
 
 bool Literal::ToBooleanIsTrue() const {
   switch (type()) {
@@ -1024,7 +1048,6 @@ uint32_t Literal::Hash() {
                     : ComputeLongHash(double_to_uint64(AsNumber()));
 }
 
-
 // static
 bool Literal::Match(void* a, void* b) {
   Literal* x = static_cast<Literal*>(a);
@@ -1051,20 +1074,5 @@ const char* CallRuntime::debug_name() {
 #endif  // DEBUG
 }
 
-#define RETURN_LABELS(NodeType) \
-  case k##NodeType:             \
-    return static_cast<const NodeType*>(this)->labels();
-
-ZonePtrList<const AstRawString>* BreakableStatement::labels() const {
-  switch (node_type()) {
-    BREAKABLE_NODE_LIST(RETURN_LABELS)
-    ITERATION_NODE_LIST(RETURN_LABELS)
-    default:
-      UNREACHABLE();
-  }
-}
-
-#undef RETURN_LABELS
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/ast/ast.h b/deps/v8/src/ast/ast.h
index 06af719d55..5bf2d7e192 100644
--- a/deps/v8/src/ast/ast.h
+++ b/deps/v8/src/ast/ast.h
@@ -15,6 +15,7 @@
 #include "src/codegen/label.h"
 #include "src/common/globals.h"
 #include "src/execution/isolate.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/heap/factory.h"
 #include "src/objects/elements-kind.h"
 #include "src/objects/function-syntax-kind.h"
@@ -89,7 +90,6 @@ namespace internal {
   V(CompoundAssignment)         \
   V(Conditional)                \
   V(CountOperation)             \
-  V(DoExpression)               \
   V(EmptyParentheses)           \
   V(FunctionLiteral)            \
   V(GetTemplateObject)          \
@@ -99,7 +99,6 @@ namespace internal {
   V(OptionalChain)              \
   V(Property)                   \
   V(Spread)                     \
-  V(StoreInArrayLiteral)        \
   V(SuperCallReference)         \
   V(SuperPropertyReference)     \
   V(TemplateLiteral)            \
@@ -295,62 +294,28 @@ class FailureExpression : public Expression {
 // V8's notion of BreakableStatement does not correspond to the notion of
 // BreakableStatement in ECMAScript. In V8, the idea is that a
 // BreakableStatement is a statement that can be the target of a break
-// statement.  The BreakableStatement AST node carries a list of labels, any of
-// which can be used as an argument to the break statement in order to target
-// it.
+// statement.
 //
-// Since we don't want to attach a list of labels to all kinds of statements, we
+// Since we don't want to track a list of labels for all kinds of statements, we
 // only declare switchs, loops, and blocks as BreakableStatements.  This means
 // that we implement breaks targeting other statement forms as breaks targeting
 // a substatement thereof. For instance, in "foo: if (b) { f(); break foo; }" we
 // pretend that foo is the label of the inner block. That's okay because one
 // can't observe the difference.
-//
-// This optimization makes it harder to detect invalid continue labels, see the
-// need for own_labels in IterationStatement.
-//
+// TODO(verwaest): Reconsider this optimization now that the tracking of labels
+// is done at runtime.
 class BreakableStatement : public Statement {
- public:
-  enum BreakableType {
-    TARGET_FOR_ANONYMOUS,
-    TARGET_FOR_NAMED_ONLY
-  };
-
-  // A list of all labels declared on the path up to the previous
-  // BreakableStatement (if any).
-  //
-  // Example: "l1: for (;;) l2: l3: { l4: if (b) l5: { s } }"
-  // labels() of the ForStatement will be l1.
-  // labels() of the Block { l4: ... } will be l2, l3.
-  // labels() of the Block { s } will be l4, l5.
-  ZonePtrList<const AstRawString>* labels() const;
-
-  // Testers.
-  bool is_target_for_anonymous() const {
-    return BreakableTypeField::decode(bit_field_) == TARGET_FOR_ANONYMOUS;
-  }
-
- private:
-  using BreakableTypeField = Statement::NextBitField<BreakableType, 1>;
-
  protected:
-  BreakableStatement(BreakableType breakable_type, int position, NodeType type)
-      : Statement(position, type) {
-    bit_field_ |= BreakableTypeField::encode(breakable_type);
-  }
-
-  template <class T, int size>
-  using NextBitField = BreakableTypeField::Next<T, size>;
+  BreakableStatement(int position, NodeType type) : Statement(position, type) {}
 };
 
-class Block : public BreakableStatement {
+class Block final : public BreakableStatement {
  public:
   ZonePtrList<Statement>* statements() { return &statements_; }
   bool ignore_completion_value() const {
     return IgnoreCompletionField::decode(bit_field_);
   }
-
-  inline ZonePtrList<const AstRawString>* labels() const;
+  bool is_breakable() const { return IsBreakableField::decode(bit_field_); }
 
   Scope* scope() const { return scope_; }
   void set_scope(Scope* scope) { scope_ = scope; }
@@ -368,68 +333,22 @@ class Block : public BreakableStatement {
   Scope* scope_;
 
   using IgnoreCompletionField = BreakableStatement::NextBitField<bool, 1>;
-  using IsLabeledField = IgnoreCompletionField::Next<bool, 1>;
+  using IsBreakableField = IgnoreCompletionField::Next<bool, 1>;
 
  protected:
-  Block(Zone* zone, ZonePtrList<const AstRawString>* labels, int capacity,
-        bool ignore_completion_value)
-      : BreakableStatement(TARGET_FOR_NAMED_ONLY, kNoSourcePosition, kBlock),
+  Block(Zone* zone, int capacity, bool ignore_completion_value,
+        bool is_breakable)
+      : BreakableStatement(kNoSourcePosition, kBlock),
         statements_(capacity, zone),
         scope_(nullptr) {
     bit_field_ |= IgnoreCompletionField::encode(ignore_completion_value) |
-                  IsLabeledField::encode(labels != nullptr);
-  }
-
-  Block(ZonePtrList<const AstRawString>* labels, bool ignore_completion_value)
-      : Block(nullptr, labels, 0, ignore_completion_value) {}
-};
-
-class LabeledBlock final : public Block {
- private:
-  friend class AstNodeFactory;
-  friend class Block;
-
-  LabeledBlock(Zone* zone, ZonePtrList<const AstRawString>* labels,
-               int capacity, bool ignore_completion_value)
-      : Block(zone, labels, capacity, ignore_completion_value),
-        labels_(labels) {
-    DCHECK_NOT_NULL(labels);
-    DCHECK_GT(labels->length(), 0);
+                  IsBreakableField::encode(is_breakable);
   }
 
-  LabeledBlock(ZonePtrList<const AstRawString>* labels,
-               bool ignore_completion_value)
-      : LabeledBlock(nullptr, labels, 0, ignore_completion_value) {}
-
-  ZonePtrList<const AstRawString>* labels_;
+  Block(bool ignore_completion_value, bool is_breakable)
+      : Block(nullptr, 0, ignore_completion_value, is_breakable) {}
 };
 
-inline ZonePtrList<const AstRawString>* Block::labels() const {
-  if (IsLabeledField::decode(bit_field_)) {
-    return static_cast<const LabeledBlock*>(this)->labels_;
-  }
-  return nullptr;
-}
-
-class DoExpression final : public Expression {
- public:
-  Block* block() { return block_; }
-  VariableProxy* result() { return result_; }
-
- private:
-  friend class AstNodeFactory;
-
-  DoExpression(Block* block, VariableProxy* result, int pos)
-      : Expression(pos, kDoExpression), block_(block), result_(result) {
-    DCHECK_NOT_NULL(block_);
-    DCHECK_NOT_NULL(result_);
-  }
-
-  Block* block_;
-  VariableProxy* result_;
-};
-
-
 class Declaration : public AstNode {
  public:
   using List = base::ThreadedList<Declaration>;
@@ -510,31 +429,12 @@ class IterationStatement : public BreakableStatement {
   Statement* body() const { return body_; }
   void set_body(Statement* s) { body_ = s; }
 
-  ZonePtrList<const AstRawString>* labels() const { return labels_; }
-
-  // A list of all labels that the iteration statement is directly prefixed
-  // with, i.e.  all the labels that a continue statement in the body can use to
-  // continue this iteration statement. This is always a subset of {labels}.
-  //
-  // Example: "l1: { l2: if (b) l3: l4: for (;;) s }"
-  // labels() of the Block will be l1.
-  // labels() of the ForStatement will be l2, l3, l4.
-  // own_labels() of the ForStatement will be l3, l4.
-  ZonePtrList<const AstRawString>* own_labels() const { return own_labels_; }
-
  protected:
-  IterationStatement(ZonePtrList<const AstRawString>* labels,
-                     ZonePtrList<const AstRawString>* own_labels, int pos,
-                     NodeType type)
-      : BreakableStatement(TARGET_FOR_ANONYMOUS, pos, type),
-        labels_(labels),
-        own_labels_(own_labels),
-        body_(nullptr) {}
+  IterationStatement(int pos, NodeType type)
+      : BreakableStatement(pos, type), body_(nullptr) {}
   void Initialize(Statement* body) { body_ = body; }
 
  private:
-  ZonePtrList<const AstRawString>* labels_;
-  ZonePtrList<const AstRawString>* own_labels_;
   Statement* body_;
 };
 
@@ -551,10 +451,8 @@ class DoWhileStatement final : public IterationStatement {
  private:
   friend class AstNodeFactory;
 
-  DoWhileStatement(ZonePtrList<const AstRawString>* labels,
-                   ZonePtrList<const AstRawString>* own_labels, int pos)
-      : IterationStatement(labels, own_labels, pos, kDoWhileStatement),
-        cond_(nullptr) {}
+  explicit DoWhileStatement(int pos)
+      : IterationStatement(pos, kDoWhileStatement), cond_(nullptr) {}
 
   Expression* cond_;
 };
@@ -572,10 +470,8 @@ class WhileStatement final : public IterationStatement {
  private:
   friend class AstNodeFactory;
 
-  WhileStatement(ZonePtrList<const AstRawString>* labels,
-                 ZonePtrList<const AstRawString>* own_labels, int pos)
-      : IterationStatement(labels, own_labels, pos, kWhileStatement),
-        cond_(nullptr) {}
+  explicit WhileStatement(int pos)
+      : IterationStatement(pos, kWhileStatement), cond_(nullptr) {}
 
   Expression* cond_;
 };
@@ -598,9 +494,8 @@ class ForStatement final : public IterationStatement {
  private:
   friend class AstNodeFactory;
 
-  ForStatement(ZonePtrList<const AstRawString>* labels,
-               ZonePtrList<const AstRawString>* own_labels, int pos)
-      : IterationStatement(labels, own_labels, pos, kForStatement),
+  explicit ForStatement(int pos)
+      : IterationStatement(pos, kForStatement),
         init_(nullptr),
         cond_(nullptr),
         next_(nullptr) {}
@@ -636,12 +531,8 @@ class ForEachStatement : public IterationStatement {
  protected:
   friend class AstNodeFactory;
 
-  ForEachStatement(ZonePtrList<const AstRawString>* labels,
-                   ZonePtrList<const AstRawString>* own_labels, int pos,
-                   NodeType type)
-      : IterationStatement(labels, own_labels, pos, type),
-        each_(nullptr),
-        subject_(nullptr) {}
+  ForEachStatement(int pos, NodeType type)
+      : IterationStatement(pos, type), each_(nullptr), subject_(nullptr) {}
 
   Expression* each_;
   Expression* subject_;
@@ -651,9 +542,7 @@ class ForInStatement final : public ForEachStatement {
  private:
   friend class AstNodeFactory;
 
-  ForInStatement(ZonePtrList<const AstRawString>* labels,
-                 ZonePtrList<const AstRawString>* own_labels, int pos)
-      : ForEachStatement(labels, own_labels, pos, kForInStatement) {}
+  explicit ForInStatement(int pos) : ForEachStatement(pos, kForInStatement) {}
 };
 
 enum class IteratorType { kNormal, kAsync };
@@ -664,11 +553,8 @@ class ForOfStatement final : public ForEachStatement {
  private:
   friend class AstNodeFactory;
 
-  ForOfStatement(ZonePtrList<const AstRawString>* labels,
-                 ZonePtrList<const AstRawString>* own_labels, int pos,
-                 IteratorType type)
-      : ForEachStatement(labels, own_labels, pos, kForOfStatement),
-        type_(type) {}
+  ForOfStatement(int pos, IteratorType type)
+      : ForEachStatement(pos, kForOfStatement), type_(type) {}
 
   IteratorType type_;
 };
@@ -796,8 +682,6 @@ class CaseClause final : public ZoneObject {
 
 class SwitchStatement final : public BreakableStatement {
  public:
-  ZonePtrList<const AstRawString>* labels() const { return labels_; }
-
   Expression* tag() const { return tag_; }
   void set_tag(Expression* t) { tag_ = t; }
 
@@ -806,14 +690,9 @@ class SwitchStatement final : public BreakableStatement {
  private:
   friend class AstNodeFactory;
 
-  SwitchStatement(Zone* zone, ZonePtrList<const AstRawString>* labels,
-                  Expression* tag, int pos)
-      : BreakableStatement(TARGET_FOR_ANONYMOUS, pos, kSwitchStatement),
-        labels_(labels),
-        tag_(tag),
-        cases_(4, zone) {}
+  SwitchStatement(Zone* zone, Expression* tag, int pos)
+      : BreakableStatement(pos, kSwitchStatement), tag_(tag), cases_(4, zone) {}
 
-  ZonePtrList<const AstRawString>* labels_;
   Expression* tag_;
   ZonePtrList<CaseClause> cases_;
 };
@@ -1088,7 +967,8 @@ class Literal final : public Expression {
 
   // Returns an appropriate Object representing this Literal, allocating
   // a heap object if needed.
-  Handle<Object> BuildValue(Isolate* isolate) const;
+  template <typename LocalIsolate>
+  Handle<Object> BuildValue(LocalIsolate* isolate) const;
 
   // Support for using Literal as a HashMap key. NOTE: Currently, this works
   // only for string and number literals!
@@ -1164,20 +1044,23 @@ class MaterializedLiteral : public Expression {
   bool NeedsInitialAllocationSite();
 
   // Populate the constant properties/elements fixed array.
-  void BuildConstants(Isolate* isolate);
+  template <typename LocalIsolate>
+  void BuildConstants(LocalIsolate* isolate);
 
   // If the expression is a literal, return the literal value;
   // if the expression is a materialized literal and is_simple
   // then return an Array or Object Boilerplate Description
   // Otherwise, return undefined literal as the placeholder
   // in the object literal boilerplate.
-  Handle<Object> GetBoilerplateValue(Expression* expression, Isolate* isolate);
+  template <typename LocalIsolate>
+  Handle<Object> GetBoilerplateValue(Expression* expression,
+                                     LocalIsolate* isolate);
 };
 
 // Node for capturing a regexp literal.
 class RegExpLiteral final : public MaterializedLiteral {
  public:
-  Handle<String> pattern() const { return pattern_->string().get<Factory>(); }
+  Handle<String> pattern() const { return pattern_->string(); }
   const AstRawString* raw_pattern() const { return pattern_; }
   int flags() const { return flags_; }
 
@@ -1329,7 +1212,6 @@ class ObjectLiteralProperty final : public LiteralProperty {
   bool emit_store_;
 };
 
-
 // An object literal has a boilerplate object that is used
 // for minimizing the work when constructing it at runtime.
 class ObjectLiteral final : public AggregateLiteral {
@@ -1365,8 +1247,9 @@ class ObjectLiteral final : public AggregateLiteral {
   int InitDepthAndFlags();
 
   // Get the boilerplate description, populating it if necessary.
+  template <typename LocalIsolate>
   Handle<ObjectBoilerplateDescription> GetOrBuildBoilerplateDescription(
-      Isolate* isolate) {
+      LocalIsolate* isolate) {
     if (boilerplate_description_.is_null()) {
       BuildBoilerplateDescription(isolate);
     }
@@ -1374,7 +1257,8 @@ class ObjectLiteral final : public AggregateLiteral {
   }
 
   // Populate the boilerplate description.
-  void BuildBoilerplateDescription(Isolate* isolate);
+  template <typename LocalIsolate>
+  void BuildBoilerplateDescription(LocalIsolate* isolate);
 
   // Mark all computed expressions that are bound to a key that
   // is shadowed by a later occurrence of the same key. For the
@@ -1460,16 +1344,18 @@ class ArrayLiteral final : public AggregateLiteral {
   int InitDepthAndFlags();
 
   // Get the boilerplate description, populating it if necessary.
+  template <typename LocalIsolate>
   Handle<ArrayBoilerplateDescription> GetOrBuildBoilerplateDescription(
-      Isolate* isolate) {
+      LocalIsolate* isolate) {
     if (boilerplate_description_.is_null()) {
       BuildBoilerplateDescription(isolate);
     }
-    return boilerplate_description();
+    return boilerplate_description_;
   }
 
   // Populate the boilerplate description.
-  void BuildBoilerplateDescription(Isolate* isolate);
+  template <typename LocalIsolate>
+  void BuildBoilerplateDescription(LocalIsolate* isolate);
 
   // Determines whether the {CreateShallowArrayLiteral} builtin can be used.
   bool IsFastCloningSupported() const;
@@ -1507,7 +1393,7 @@ class VariableProxy final : public Expression {
  public:
   bool IsValidReferenceExpression() const { return !is_new_target(); }
 
-  Handle<String> name() const { return raw_name()->string().get<Factory>(); }
+  Handle<String> name() const { return raw_name()->string(); }
   const AstRawString* raw_name() const {
     return is_resolved() ? var_->raw_name() : raw_name_;
   }
@@ -2039,30 +1925,6 @@ class Spread final : public Expression {
   Expression* expression_;
 };
 
-// The StoreInArrayLiteral node corresponds to the StaInArrayLiteral bytecode.
-// It is used in the rewriting of destructuring assignments that contain an
-// array rest pattern.
-class StoreInArrayLiteral final : public Expression {
- public:
-  Expression* array() const { return array_; }
-  Expression* index() const { return index_; }
-  Expression* value() const { return value_; }
-
- private:
-  friend class AstNodeFactory;
-
-  StoreInArrayLiteral(Expression* array, Expression* index, Expression* value,
-                      int position)
-      : Expression(position, kStoreInArrayLiteral),
-        array_(array),
-        index_(index),
-        value_(value) {}
-
-  Expression* array_;
-  Expression* index_;
-  Expression* value_;
-};
-
 class Conditional final : public Expression {
  public:
   Expression* condition() const { return condition_; }
@@ -2218,9 +2080,9 @@ class FunctionLiteral final : public Expression {
 
   // Empty handle means that the function does not have a shared name (i.e.
   // the name will be set dynamically after creation of the function closure).
-  MaybeHandle<String> name() const {
-    return raw_name_ ? raw_name_->string().get<Factory>()
-                     : MaybeHandle<String>();
+  template <typename LocalIsolate>
+  MaybeHandle<String> GetName(LocalIsolate* isolate) const {
+    return raw_name_ ? raw_name_->AllocateFlat(isolate) : MaybeHandle<String>();
   }
   bool has_shared_name() const { return raw_name_ != nullptr; }
   const AstConsString* raw_name() const { return raw_name_; }
@@ -2278,21 +2140,26 @@ class FunctionLiteral final : public Expression {
   // Returns either name or inferred name as a cstring.
   std::unique_ptr<char[]> GetDebugName() const;
 
-  Handle<String> inferred_name() const {
+  Handle<String> GetInferredName(Isolate* isolate) {
     if (!inferred_name_.is_null()) {
       DCHECK_NULL(raw_inferred_name_);
       return inferred_name_;
     }
     if (raw_inferred_name_ != nullptr) {
-      return raw_inferred_name_->string().get<Factory>();
+      return raw_inferred_name_->GetString(isolate);
     }
     UNREACHABLE();
   }
+  Handle<String> GetInferredName(OffThreadIsolate* isolate) const {
+    DCHECK(inferred_name_.is_null());
+    DCHECK_NOT_NULL(raw_inferred_name_);
+    return raw_inferred_name_->GetString(isolate);
+  }
   const AstConsString* raw_inferred_name() { return raw_inferred_name_; }
 
   // Only one of {set_inferred_name, set_raw_inferred_name} should be called.
   void set_inferred_name(Handle<String> inferred_name);
-  void set_raw_inferred_name(const AstConsString* raw_inferred_name);
+  void set_raw_inferred_name(AstConsString* raw_inferred_name);
 
   bool pretenure() const { return Pretenure::decode(bit_field_); }
   void set_pretenure() { bit_field_ = Pretenure::update(bit_field_, true); }
@@ -2351,7 +2218,20 @@ class FunctionLiteral final : public Expression {
     return RequiresInstanceMembersInitializer::decode(bit_field_);
   }
 
-  bool requires_brand_initialization() const;
+  void set_has_static_private_methods_or_accessors(bool value) {
+    bit_field_ =
+        HasStaticPrivateMethodsOrAccessorsField::update(bit_field_, value);
+  }
+  bool has_static_private_methods_or_accessors() const {
+    return HasStaticPrivateMethodsOrAccessorsField::decode(bit_field_);
+  }
+
+  void set_class_scope_has_private_brand(bool value) {
+    bit_field_ = ClassScopeHasPrivateBrandField::update(bit_field_, value);
+  }
+  bool class_scope_has_private_brand() const {
+    return ClassScopeHasPrivateBrandField::decode(bit_field_);
+  }
 
   bool private_name_lookup_skips_outer_class() const;
 
@@ -2403,7 +2283,11 @@ class FunctionLiteral final : public Expression {
       HasDuplicateParameters::Next<BailoutReason, 8>;
   using RequiresInstanceMembersInitializer =
       DontOptimizeReasonField::Next<bool, 1>;
-  using HasBracesField = RequiresInstanceMembersInitializer::Next<bool, 1>;
+  using ClassScopeHasPrivateBrandField =
+      RequiresInstanceMembersInitializer::Next<bool, 1>;
+  using HasStaticPrivateMethodsOrAccessorsField =
+      ClassScopeHasPrivateBrandField::Next<bool, 1>;
+  using HasBracesField = HasStaticPrivateMethodsOrAccessorsField::Next<bool, 1>;
   using OneshotIIFEBit = HasBracesField::Next<bool, 1>;
 
   // expected_property_count_ is the sum of instance fields and properties.
@@ -2418,7 +2302,7 @@ class FunctionLiteral final : public Expression {
   const AstConsString* raw_name_;
   DeclarationScope* scope_;
   ZonePtrList<Statement> body_;
-  const AstConsString* raw_inferred_name_;
+  AstConsString* raw_inferred_name_;
   Handle<String> inferred_name_;
   ProducedPreparseData* produced_preparse_data_;
 };
@@ -2569,7 +2453,7 @@ class ClassLiteral final : public Expression {
 
 class NativeFunctionLiteral final : public Expression {
  public:
-  Handle<String> name() const { return name_->string().get<Factory>(); }
+  Handle<String> name() const { return name_->string(); }
   const AstRawString* raw_name() const { return name_; }
   v8::Extension* extension() const { return extension_; }
 
@@ -2663,7 +2547,9 @@ class GetTemplateObject final : public Expression {
     return raw_strings_;
   }
 
-  Handle<TemplateObjectDescription> GetOrBuildDescription(Isolate* isolate);
+  template <typename LocalIsolate>
+  Handle<TemplateObjectDescription> GetOrBuildDescription(
+      LocalIsolate* isolate);
 
  private:
   friend class AstNodeFactory;
@@ -2825,59 +2711,46 @@ class AstNodeFactory final {
   }
 
   Block* NewBlock(int capacity, bool ignore_completion_value) {
-    return new (zone_) Block(zone_, nullptr, capacity, ignore_completion_value);
+    return new (zone_) Block(zone_, capacity, ignore_completion_value, false);
   }
 
-  Block* NewBlock(bool ignore_completion_value,
-                  ZonePtrList<const AstRawString>* labels) {
-    return labels != nullptr
-               ? new (zone_) LabeledBlock(labels, ignore_completion_value)
-               : new (zone_) Block(labels, ignore_completion_value);
+  Block* NewBlock(bool ignore_completion_value, bool is_breakable) {
+    return new (zone_) Block(ignore_completion_value, is_breakable);
   }
 
   Block* NewBlock(bool ignore_completion_value,
                   const ScopedPtrList<Statement>& statements) {
-    Block* result = NewBlock(ignore_completion_value, nullptr);
+    Block* result = NewBlock(ignore_completion_value, false);
     result->InitializeStatements(statements, zone_);
     return result;
   }
 
-#define STATEMENT_WITH_LABELS(NodeType)                                \
-  NodeType* New##NodeType(ZonePtrList<const AstRawString>* labels,     \
-                          ZonePtrList<const AstRawString>* own_labels, \
-                          int pos) {                                   \
-    return new (zone_) NodeType(labels, own_labels, pos);              \
-  }
-  STATEMENT_WITH_LABELS(DoWhileStatement)
-  STATEMENT_WITH_LABELS(WhileStatement)
-  STATEMENT_WITH_LABELS(ForStatement)
-#undef STATEMENT_WITH_LABELS
+#define STATEMENT_WITH_POSITION(NodeType) \
+  NodeType* New##NodeType(int pos) { return new (zone_) NodeType(pos); }
+  STATEMENT_WITH_POSITION(DoWhileStatement)
+  STATEMENT_WITH_POSITION(WhileStatement)
+  STATEMENT_WITH_POSITION(ForStatement)
+#undef STATEMENT_WITH_POSITION
 
-  SwitchStatement* NewSwitchStatement(ZonePtrList<const AstRawString>* labels,
-                                      Expression* tag, int pos) {
-    return new (zone_) SwitchStatement(zone_, labels, tag, pos);
+  SwitchStatement* NewSwitchStatement(Expression* tag, int pos) {
+    return new (zone_) SwitchStatement(zone_, tag, pos);
   }
 
-  ForEachStatement* NewForEachStatement(
-      ForEachStatement::VisitMode visit_mode,
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos) {
+  ForEachStatement* NewForEachStatement(ForEachStatement::VisitMode visit_mode,
+                                        int pos) {
     switch (visit_mode) {
       case ForEachStatement::ENUMERATE: {
-        return new (zone_) ForInStatement(labels, own_labels, pos);
+        return new (zone_) ForInStatement(pos);
       }
       case ForEachStatement::ITERATE: {
-        return new (zone_)
-            ForOfStatement(labels, own_labels, pos, IteratorType::kNormal);
+        return new (zone_) ForOfStatement(pos, IteratorType::kNormal);
       }
     }
     UNREACHABLE();
   }
 
-  ForOfStatement* NewForOfStatement(ZonePtrList<const AstRawString>* labels,
-                                    ZonePtrList<const AstRawString>* own_labels,
-                                    int pos, IteratorType type) {
-    return new (zone_) ForOfStatement(labels, own_labels, pos, type);
+  ForOfStatement* NewForOfStatement(int pos, IteratorType type) {
+    return new (zone_) ForOfStatement(pos, type);
   }
 
   ExpressionStatement* NewExpressionStatement(Expression* expression, int pos) {
@@ -3176,12 +3049,6 @@ class AstNodeFactory final {
     return new (zone_) Spread(expression, pos, expr_pos);
   }
 
-  StoreInArrayLiteral* NewStoreInArrayLiteral(Expression* array,
-                                              Expression* index,
-                                              Expression* value, int pos) {
-    return new (zone_) StoreInArrayLiteral(array, index, value, pos);
-  }
-
   Conditional* NewConditional(Expression* condition,
                               Expression* then_expression,
                               Expression* else_expression,
@@ -3292,11 +3159,6 @@ class AstNodeFactory final {
     return new (zone_) NativeFunctionLiteral(name, extension, pos);
   }
 
-  DoExpression* NewDoExpression(Block* block, Variable* result_var, int pos) {
-    VariableProxy* result = NewVariableProxy(result_var, pos);
-    return new (zone_) DoExpression(block, result, pos);
-  }
-
   SuperPropertyReference* NewSuperPropertyReference(Expression* home_object,
                                                     int pos) {
     return new (zone_) SuperPropertyReference(home_object, pos);
diff --git a/deps/v8/src/ast/modules.cc b/deps/v8/src/ast/modules.cc
index 533a11524c..99371306fc 100644
--- a/deps/v8/src/ast/modules.cc
+++ b/deps/v8/src/ast/modules.cc
@@ -5,6 +5,7 @@
 #include "src/ast/modules.h"
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/scopes.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/objects/module-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/parsing/pending-compilation-error-handler.h"
@@ -84,17 +85,17 @@ void SourceTextModuleDescriptor::AddStarExport(
 }
 
 namespace {
-Handle<PrimitiveHeapObject> ToStringOrUndefined(Isolate* isolate,
+template <typename LocalIsolate>
+Handle<PrimitiveHeapObject> ToStringOrUndefined(LocalIsolate* isolate,
                                                 const AstRawString* s) {
-  return (s == nullptr)
-             ? Handle<PrimitiveHeapObject>::cast(
-                   isolate->factory()->undefined_value())
-             : Handle<PrimitiveHeapObject>::cast(s->string().get<Factory>());
+  if (s == nullptr) return isolate->factory()->undefined_value();
+  return s->string();
 }
 }  // namespace
 
+template <typename LocalIsolate>
 Handle<SourceTextModuleInfoEntry> SourceTextModuleDescriptor::Entry::Serialize(
-    Isolate* isolate) const {
+    LocalIsolate* isolate) const {
   CHECK(Smi::IsValid(module_request));  // TODO(neis): Check earlier?
   return SourceTextModuleInfoEntry::New(
       isolate, ToStringOrUndefined(isolate, export_name),
@@ -102,9 +103,14 @@ Handle<SourceTextModuleInfoEntry> SourceTextModuleDescriptor::Entry::Serialize(
       ToStringOrUndefined(isolate, import_name), module_request, cell_index,
       location.beg_pos, location.end_pos);
 }
+template Handle<SourceTextModuleInfoEntry>
+SourceTextModuleDescriptor::Entry::Serialize(Isolate* isolate) const;
+template Handle<SourceTextModuleInfoEntry>
+SourceTextModuleDescriptor::Entry::Serialize(OffThreadIsolate* isolate) const;
 
+template <typename LocalIsolate>
 Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
-    Isolate* isolate, Zone* zone) const {
+    LocalIsolate* isolate, Zone* zone) const {
   // We serialize regular exports in a way that lets us later iterate over their
   // local names and for each local name immediately access all its export
   // names.  (Regular exports have neither import name nor module request.)
@@ -127,7 +133,7 @@ Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
 
     Handle<FixedArray> export_names = isolate->factory()->NewFixedArray(count);
     data[index + SourceTextModuleInfo::kRegularExportLocalNameOffset] =
-        it->second->local_name->string().get<Factory>();
+        it->second->local_name->string();
     data[index + SourceTextModuleInfo::kRegularExportCellIndexOffset] =
         handle(Smi::FromInt(it->second->cell_index), isolate);
     data[index + SourceTextModuleInfo::kRegularExportExportNamesOffset] =
@@ -137,7 +143,7 @@ Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
     // Collect the export names.
     int i = 0;
     for (; it != next; ++it) {
-      export_names->set(i++, *it->second->export_name->string().get<Factory>());
+      export_names->set(i++, *it->second->export_name->string());
     }
     DCHECK_EQ(i, count);
 
@@ -155,6 +161,10 @@ Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
   }
   return result;
 }
+template Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
+    Isolate* isolate, Zone* zone) const;
+template Handle<FixedArray> SourceTextModuleDescriptor::SerializeRegularExports(
+    OffThreadIsolate* isolate, Zone* zone) const;
 
 void SourceTextModuleDescriptor::MakeIndirectExportsExplicit(Zone* zone) {
   for (auto it = regular_exports_.begin(); it != regular_exports_.end();) {
diff --git a/deps/v8/src/ast/modules.h b/deps/v8/src/ast/modules.h
index 4921d41932..b57387b25f 100644
--- a/deps/v8/src/ast/modules.h
+++ b/deps/v8/src/ast/modules.h
@@ -107,7 +107,8 @@ class SourceTextModuleDescriptor : public ZoneObject {
           module_request(-1),
           cell_index(0) {}
 
-    Handle<SourceTextModuleInfoEntry> Serialize(Isolate* isolate) const;
+    template <typename LocalIsolate>
+    Handle<SourceTextModuleInfoEntry> Serialize(LocalIsolate* isolate) const;
   };
 
   enum CellIndexKind { kInvalid, kExport, kImport };
@@ -184,7 +185,8 @@ class SourceTextModuleDescriptor : public ZoneObject {
     namespace_imports_.push_back(entry);
   }
 
-  Handle<FixedArray> SerializeRegularExports(Isolate* isolate,
+  template <typename LocalIsolate>
+  Handle<FixedArray> SerializeRegularExports(LocalIsolate* isolate,
                                              Zone* zone) const;
 
  private:
diff --git a/deps/v8/src/ast/prettyprinter.cc b/deps/v8/src/ast/prettyprinter.cc
index 4d8bd006c5..20dca56cc4 100644
--- a/deps/v8/src/ast/prettyprinter.cc
+++ b/deps/v8/src/ast/prettyprinter.cc
@@ -17,7 +17,8 @@
 namespace v8 {
 namespace internal {
 
-CallPrinter::CallPrinter(Isolate* isolate, bool is_user_js)
+CallPrinter::CallPrinter(Isolate* isolate, bool is_user_js,
+                         SpreadErrorInArgsHint error_in_spread_args)
     : builder_(new IncrementalStringBuilder(isolate)) {
   isolate_ = isolate;
   position_ = 0;
@@ -30,6 +31,8 @@ CallPrinter::CallPrinter(Isolate* isolate, bool is_user_js)
   destructuring_prop_ = nullptr;
   destructuring_assignment_ = nullptr;
   is_user_js_ = is_user_js;
+  error_in_spread_args_ = error_in_spread_args;
+  spread_arg_ = nullptr;
   function_kind_ = kNormalFunction;
   InitializeAstVisitor(isolate);
 }
@@ -235,9 +238,6 @@ void CallPrinter::VisitInitializeClassMembersStatement(
 void CallPrinter::VisitNativeFunctionLiteral(NativeFunctionLiteral* node) {}
 
 
-void CallPrinter::VisitDoExpression(DoExpression* node) { Find(node->block()); }
-
-
 void CallPrinter::VisitConditional(Conditional* node) {
   Find(node->condition());
   Find(node->then_expression());
@@ -404,9 +404,20 @@ void CallPrinter::VisitProperty(Property* node) {
 void CallPrinter::VisitCall(Call* node) {
   bool was_found = false;
   if (node->position() == position_) {
+    if (error_in_spread_args_ == SpreadErrorInArgsHint::kErrorInArgs) {
+      found_ = true;
+      spread_arg_ = node->arguments()->last()->AsSpread()->expression();
+      Find(spread_arg_, true);
+
+      done_ = true;
+      found_ = false;
+      return;
+    }
+
     is_call_error_ = true;
     was_found = !found_;
   }
+
   if (was_found) {
     // Bail out if the error is caused by a direct call to a variable in
     // non-user JS code. The variable name is meaningless due to minification.
@@ -429,6 +440,16 @@ void CallPrinter::VisitCall(Call* node) {
 void CallPrinter::VisitCallNew(CallNew* node) {
   bool was_found = false;
   if (node->position() == position_) {
+    if (error_in_spread_args_ == SpreadErrorInArgsHint::kErrorInArgs) {
+      found_ = true;
+      spread_arg_ = node->arguments()->last()->AsSpread()->expression();
+      Find(spread_arg_, true);
+
+      done_ = true;
+      found_ = false;
+      return;
+    }
+
     is_call_error_ = true;
     was_found = !found_;
   }
@@ -515,12 +536,6 @@ void CallPrinter::VisitSpread(Spread* node) {
   Print(")");
 }
 
-void CallPrinter::VisitStoreInArrayLiteral(StoreInArrayLiteral* node) {
-  Find(node->array());
-  Find(node->index());
-  Find(node->value());
-}
-
 void CallPrinter::VisitEmptyParentheses(EmptyParentheses* node) {
   UNREACHABLE();
 }
@@ -587,7 +602,7 @@ void CallPrinter::PrintLiteral(Handle<Object> value, bool quote) {
 
 
 void CallPrinter::PrintLiteral(const AstRawString* value, bool quote) {
-  PrintLiteral(value->string().get<Factory>(), quote);
+  PrintLiteral(value->string(), quote);
 }
 
 //-----------------------------------------------------------------------------
@@ -638,15 +653,6 @@ void AstPrinter::Print(const char* format, ...) {
   }
 }
 
-void AstPrinter::PrintLabels(ZonePtrList<const AstRawString>* labels) {
-  if (labels != nullptr) {
-    for (int i = 0; i < labels->length(); i++) {
-      PrintLiteral(labels->at(i), false);
-      Print(": ");
-    }
-  }
-}
-
 void AstPrinter::PrintLiteral(Literal* literal, bool quote) {
   switch (literal->type()) {
     case Literal::kString:
@@ -798,16 +804,6 @@ void AstPrinter::PrintLiteralWithModeIndented(const char* info, Variable* var,
   }
 }
 
-void AstPrinter::PrintLabelsIndented(ZonePtrList<const AstRawString>* labels,
-                                     const char* prefix) {
-  if (labels == nullptr || labels->length() == 0) return;
-  PrintIndented(prefix);
-  Print("LABELS ");
-  PrintLabels(labels);
-  Print("\n");
-}
-
-
 void AstPrinter::PrintIndentedVisit(const char* s, AstNode* node) {
   if (node != nullptr) {
     IndentedScope indent(this, s, node->position());
@@ -832,6 +828,12 @@ const char* AstPrinter::PrintProgram(FunctionLiteral* program) {
     if (program->requires_instance_members_initializer()) {
       Print(" REQUIRES INSTANCE FIELDS INITIALIZER\n");
     }
+    if (program->class_scope_has_private_brand()) {
+      Print(" CLASS SCOPE HAS PRIVATE BRAND\n");
+    }
+    if (program->has_static_private_methods_or_accessors()) {
+      Print(" HAS STATIC PRIVATE METHODS\n");
+    }
     PrintParameters(program->scope());
     PrintDeclarations(program->scope()->declarations());
     PrintStatements(program->body());
@@ -881,7 +883,6 @@ void AstPrinter::VisitBlock(Block* node) {
   const char* block_txt =
       node->ignore_completion_value() ? "BLOCK NOCOMPLETIONS" : "BLOCK";
   IndentedScope indent(this, block_txt, node->position());
-  PrintLabelsIndented(node->labels());
   PrintStatements(node->statements());
 }
 
@@ -932,13 +933,11 @@ void AstPrinter::VisitIfStatement(IfStatement* node) {
 
 void AstPrinter::VisitContinueStatement(ContinueStatement* node) {
   IndentedScope indent(this, "CONTINUE", node->position());
-  PrintLabelsIndented(node->target()->labels());
 }
 
 
 void AstPrinter::VisitBreakStatement(BreakStatement* node) {
   IndentedScope indent(this, "BREAK", node->position());
-  PrintLabelsIndented(node->target()->labels());
 }
 
 
@@ -957,7 +956,6 @@ void AstPrinter::VisitWithStatement(WithStatement* node) {
 
 void AstPrinter::VisitSwitchStatement(SwitchStatement* node) {
   IndentedScope indent(this, "SWITCH", node->position());
-  PrintLabelsIndented(node->labels());
   PrintIndentedVisit("TAG", node->tag());
   for (CaseClause* clause : *node->cases()) {
     if (clause->is_default()) {
@@ -974,8 +972,6 @@ void AstPrinter::VisitSwitchStatement(SwitchStatement* node) {
 
 void AstPrinter::VisitDoWhileStatement(DoWhileStatement* node) {
   IndentedScope indent(this, "DO", node->position());
-  PrintLabelsIndented(node->labels());
-  PrintLabelsIndented(node->own_labels(), "OWN ");
   PrintIndentedVisit("BODY", node->body());
   PrintIndentedVisit("COND", node->cond());
 }
@@ -983,8 +979,6 @@ void AstPrinter::VisitDoWhileStatement(DoWhileStatement* node) {
 
 void AstPrinter::VisitWhileStatement(WhileStatement* node) {
   IndentedScope indent(this, "WHILE", node->position());
-  PrintLabelsIndented(node->labels());
-  PrintLabelsIndented(node->own_labels(), "OWN ");
   PrintIndentedVisit("COND", node->cond());
   PrintIndentedVisit("BODY", node->body());
 }
@@ -992,8 +986,6 @@ void AstPrinter::VisitWhileStatement(WhileStatement* node) {
 
 void AstPrinter::VisitForStatement(ForStatement* node) {
   IndentedScope indent(this, "FOR", node->position());
-  PrintLabelsIndented(node->labels());
-  PrintLabelsIndented(node->own_labels(), "OWN ");
   if (node->init()) PrintIndentedVisit("INIT", node->init());
   if (node->cond()) PrintIndentedVisit("COND", node->cond());
   PrintIndentedVisit("BODY", node->body());
@@ -1003,8 +995,6 @@ void AstPrinter::VisitForStatement(ForStatement* node) {
 
 void AstPrinter::VisitForInStatement(ForInStatement* node) {
   IndentedScope indent(this, "FOR IN", node->position());
-  PrintLabelsIndented(node->labels());
-  PrintLabelsIndented(node->own_labels(), "OWN ");
   PrintIndentedVisit("FOR", node->each());
   PrintIndentedVisit("IN", node->subject());
   PrintIndentedVisit("BODY", node->body());
@@ -1013,8 +1003,6 @@ void AstPrinter::VisitForInStatement(ForInStatement* node) {
 
 void AstPrinter::VisitForOfStatement(ForOfStatement* node) {
   IndentedScope indent(this, "FOR OF", node->position());
-  PrintLabelsIndented(node->labels());
-  PrintLabelsIndented(node->own_labels(), "OWN ");
   const char* for_type;
   switch (node->type()) {
     case IteratorType::kNormal:
@@ -1155,12 +1143,6 @@ void AstPrinter::VisitNativeFunctionLiteral(NativeFunctionLiteral* node) {
 }
 
 
-void AstPrinter::VisitDoExpression(DoExpression* node) {
-  IndentedScope indent(this, "DO EXPRESSION", node->position());
-  PrintStatements(node->block()->statements());
-}
-
-
 void AstPrinter::VisitConditional(Conditional* node) {
   IndentedScope indent(this, "CONDITIONAL", node->position());
   PrintIndentedVisit("CONDITION", node->condition());
@@ -1428,13 +1410,6 @@ void AstPrinter::VisitSpread(Spread* node) {
   Visit(node->expression());
 }
 
-void AstPrinter::VisitStoreInArrayLiteral(StoreInArrayLiteral* node) {
-  IndentedScope indent(this, "STORE IN ARRAY LITERAL", node->position());
-  PrintIndentedVisit("ARRAY", node->array());
-  PrintIndentedVisit("INDEX", node->index());
-  PrintIndentedVisit("VALUE", node->value());
-}
-
 void AstPrinter::VisitEmptyParentheses(EmptyParentheses* node) {
   IndentedScope indent(this, "()", node->position());
 }
diff --git a/deps/v8/src/ast/prettyprinter.h b/deps/v8/src/ast/prettyprinter.h
index 795436d422..4b939c7d17 100644
--- a/deps/v8/src/ast/prettyprinter.h
+++ b/deps/v8/src/ast/prettyprinter.h
@@ -19,7 +19,11 @@ class IncrementalStringBuilder;  // to avoid including string-builder-inl.h
 
 class CallPrinter final : public AstVisitor<CallPrinter> {
  public:
-  explicit CallPrinter(Isolate* isolate, bool is_user_js);
+  enum class SpreadErrorInArgsHint { kErrorInArgs, kNoErrorInArgs };
+
+  explicit CallPrinter(Isolate* isolate, bool is_user_js,
+                       SpreadErrorInArgsHint error_in_spread_args =
+                           SpreadErrorInArgsHint::kNoErrorInArgs);
   ~CallPrinter();
 
   // The following routine prints the node with position |position| into a
@@ -32,7 +36,9 @@ class CallPrinter final : public AstVisitor<CallPrinter> {
     kCallAndNormalIterator,
     kCallAndAsyncIterator
   };
+
   ErrorHint GetErrorHint() const;
+  Expression* spread_arg() const { return spread_arg_; }
   ObjectLiteralProperty* destructuring_prop() const {
     return destructuring_prop_;
   }
@@ -62,8 +68,10 @@ class CallPrinter final : public AstVisitor<CallPrinter> {
   bool is_iterator_error_;
   bool is_async_iterator_error_;
   bool is_call_error_;
+  SpreadErrorInArgsHint error_in_spread_args_;
   ObjectLiteralProperty* destructuring_prop_;
   Assignment* destructuring_assignment_;
+  Expression* spread_arg_;
   FunctionKind function_kind_;
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
 
diff --git a/deps/v8/src/ast/scopes.cc b/deps/v8/src/ast/scopes.cc
index b422e56c4f..8c13556db9 100644
--- a/deps/v8/src/ast/scopes.cc
+++ b/deps/v8/src/ast/scopes.cc
@@ -11,6 +11,7 @@
 #include "src/base/optional.h"
 #include "src/builtins/accessors.h"
 #include "src/common/message-template.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/init/bootstrapper.h"
 #include "src/logging/counters.h"
 #include "src/objects/module-inl.h"
@@ -572,10 +573,11 @@ bool DeclarationScope::Analyze(ParseInfo* info) {
   DeclarationScope* scope = info->literal()->scope();
 
   base::Optional<AllowHandleDereference> allow_deref;
-  if (!info->maybe_outer_scope_info().is_null()) {
-    // Allow dereferences to the scope info if there is one.
+#ifdef DEBUG
+  if (scope->outer_scope() && !scope->outer_scope()->scope_info_.is_null()) {
     allow_deref.emplace();
   }
+#endif
 
   if (scope->is_eval_scope() && is_sloppy(scope->language_mode())) {
     AstNodeFactory factory(info->ast_value_factory(), info->zone());
@@ -835,7 +837,8 @@ Variable* Scope::LookupInScopeInfo(const AstRawString* name, Scope* cache) {
   DCHECK_NULL(cache->variables_.Lookup(name));
   DisallowHeapAllocation no_gc;
 
-  String name_handle = *name->string().get<Factory>();
+  String name_handle = *name->string();
+  ScopeInfo scope_info = *scope_info_;
   // The Scope is backed up by ScopeInfo. This means it cannot operate in a
   // heap-independent mode, and all strings must be internalized immediately. So
   // it's ok to get the Handle<String> here.
@@ -850,21 +853,21 @@ Variable* Scope::LookupInScopeInfo(const AstRawString* name, Scope* cache) {
 
   {
     location = VariableLocation::CONTEXT;
-    index = ScopeInfo::ContextSlotIndex(*scope_info_, name_handle, &mode,
-                                        &init_flag, &maybe_assigned_flag,
-                                        &is_static_flag);
+    index =
+        ScopeInfo::ContextSlotIndex(scope_info, name_handle, &mode, &init_flag,
+                                    &maybe_assigned_flag, &is_static_flag);
     found = index >= 0;
   }
 
   if (!found && is_module_scope()) {
     location = VariableLocation::MODULE;
-    index = scope_info_->ModuleIndex(name_handle, &mode, &init_flag,
-                                     &maybe_assigned_flag);
+    index = scope_info.ModuleIndex(name_handle, &mode, &init_flag,
+                                   &maybe_assigned_flag);
     found = index != 0;
   }
 
   if (!found) {
-    index = scope_info_->FunctionContextSlotIndex(name_handle);
+    index = scope_info.FunctionContextSlotIndex(name_handle);
     if (index < 0) return nullptr;  // Nowhere found.
     Variable* var = AsDeclarationScope()->DeclareFunctionVar(name, cache);
     DCHECK_EQ(VariableMode::kConst, var->mode());
@@ -873,7 +876,7 @@ Variable* Scope::LookupInScopeInfo(const AstRawString* name, Scope* cache) {
   }
 
   if (!is_module_scope()) {
-    DCHECK_NE(index, scope_info_->ReceiverContextSlotIndex());
+    DCHECK_NE(index, scope_info.ReceiverContextSlotIndex());
   }
 
   bool was_added;
@@ -1236,7 +1239,7 @@ bool DeclarationScope::AllocateVariables(ParseInfo* info) {
     return false;
   }
 
-  if (!ResolveVariablesRecursively(info)) {
+  if (!ResolveVariablesRecursively(info->scope())) {
     DCHECK(info->pending_error_handler()->has_pending_error());
     return false;
   }
@@ -1427,9 +1430,8 @@ bool Scope::IsOuterScopeOf(Scope* other) const {
 }
 
 void Scope::CollectNonLocals(DeclarationScope* max_outer_scope,
-                             Isolate* isolate, ParseInfo* info,
-                             Handle<StringSet>* non_locals) {
-  this->ForEach([max_outer_scope, isolate, info, non_locals](Scope* scope) {
+                             Isolate* isolate, Handle<StringSet>* non_locals) {
+  this->ForEach([max_outer_scope, isolate, non_locals](Scope* scope) {
     // Module variables must be allocated before variable resolution
     // to ensure that UpdateNeedsHoleCheck() can detect import variables.
     if (scope->is_module_scope()) {
@@ -1451,7 +1453,7 @@ void Scope::CollectNonLocals(DeclarationScope* max_outer_scope,
         // In this case we need to leave scopes in a way that they can be
         // allocated. If we resolved variables from lazy parsed scopes, we need
         // to context allocate the var.
-        scope->ResolveTo(info, proxy, var);
+        scope->ResolveTo(proxy, var);
         if (!var->is_dynamic() && lookup != scope)
           var->ForceContextAllocation();
       }
@@ -1500,8 +1502,8 @@ void Scope::AnalyzePartially(DeclarationScope* max_outer_scope,
 }
 
 Handle<StringSet> DeclarationScope::CollectNonLocals(
-    Isolate* isolate, ParseInfo* info, Handle<StringSet> non_locals) {
-  Scope::CollectNonLocals(this, isolate, info, &non_locals);
+    Isolate* isolate, Handle<StringSet> non_locals) {
+  Scope::CollectNonLocals(this, isolate, &non_locals);
   return non_locals;
 }
 
@@ -2105,12 +2107,11 @@ Variable* Scope::LookupSloppyEval(VariableProxy* proxy, Scope* scope,
   return var;
 }
 
-void Scope::ResolveVariable(ParseInfo* info, VariableProxy* proxy) {
-  DCHECK(info->script_scope()->is_script_scope());
+void Scope::ResolveVariable(VariableProxy* proxy) {
   DCHECK(!proxy->is_resolved());
   Variable* var = Lookup<kParsedScope>(proxy, this, nullptr);
   DCHECK_NOT_NULL(var);
-  ResolveTo(info, proxy, var);
+  ResolveTo(proxy, var);
 }
 
 namespace {
@@ -2173,7 +2174,7 @@ void UpdateNeedsHoleCheck(Variable* var, VariableProxy* proxy, Scope* scope) {
 
 }  // anonymous namespace
 
-void Scope::ResolveTo(ParseInfo* info, VariableProxy* proxy, Variable* var) {
+void Scope::ResolveTo(VariableProxy* proxy, Variable* var) {
   DCHECK_NOT_NULL(var);
   UpdateNeedsHoleCheck(var, proxy, this);
   proxy->BindTo(var);
@@ -2195,14 +2196,12 @@ void Scope::ResolvePreparsedVariable(VariableProxy* proxy, Scope* scope,
   }
 }
 
-bool Scope::ResolveVariablesRecursively(ParseInfo* info) {
-  DCHECK(info->script_scope()->is_script_scope());
+bool Scope::ResolveVariablesRecursively(Scope* end) {
   // Lazy parsed declaration scopes are already partially analyzed. If there are
   // unresolved references remaining, they just need to be resolved in outer
   // scopes.
   if (WasLazilyParsed(this)) {
     DCHECK_EQ(variables_.occupancy(), 0);
-    Scope* end = info->scope();
     // Resolve in all parsed scopes except for the script scope.
     if (!end->is_script_scope()) end = end->outer_scope();
 
@@ -2212,13 +2211,13 @@ bool Scope::ResolveVariablesRecursively(ParseInfo* info) {
   } else {
     // Resolve unresolved variables for this scope.
     for (VariableProxy* proxy : unresolved_list_) {
-      ResolveVariable(info, proxy);
+      ResolveVariable(proxy);
     }
 
     // Resolve unresolved variables for inner scopes.
     for (Scope* scope = inner_scope_; scope != nullptr;
          scope = scope->sibling_) {
-      if (!scope->ResolveVariablesRecursively(info)) return false;
+      if (!scope->ResolveVariablesRecursively(end)) return false;
     }
   }
   return true;
@@ -2449,7 +2448,8 @@ void Scope::AllocateVariablesRecursively() {
   });
 }
 
-void Scope::AllocateScopeInfosRecursively(Isolate* isolate,
+template <typename LocalIsolate>
+void Scope::AllocateScopeInfosRecursively(LocalIsolate* isolate,
                                           MaybeHandle<ScopeInfo> outer_scope) {
   DCHECK(scope_info_.is_null());
   MaybeHandle<ScopeInfo> next_outer_scope = outer_scope;
@@ -2470,6 +2470,13 @@ void Scope::AllocateScopeInfosRecursively(Isolate* isolate,
   }
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void Scope::
+    AllocateScopeInfosRecursively<Isolate>(Isolate* isolate,
+                                           MaybeHandle<ScopeInfo> outer_scope);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void Scope::
+    AllocateScopeInfosRecursively<OffThreadIsolate>(
+        OffThreadIsolate* isolate, MaybeHandle<ScopeInfo> outer_scope);
+
 void DeclarationScope::RecalcPrivateNameContextChain() {
   // The outermost scope in a class heritage expression is marked to skip the
   // class scope during private name resolution. It is possible, however, that
@@ -2512,7 +2519,9 @@ void DeclarationScope::RecordNeedsPrivateNameContextChainRecalc() {
 }
 
 // static
-void DeclarationScope::AllocateScopeInfos(ParseInfo* info, Isolate* isolate) {
+template <typename LocalIsolate>
+void DeclarationScope::AllocateScopeInfos(ParseInfo* info,
+                                          LocalIsolate* isolate) {
   DeclarationScope* scope = info->literal()->scope();
 
   // No one else should have allocated a scope info for this scope yet.
@@ -2520,6 +2529,7 @@ void DeclarationScope::AllocateScopeInfos(ParseInfo* info, Isolate* isolate) {
 
   MaybeHandle<ScopeInfo> outer_scope;
   if (scope->outer_scope_ != nullptr) {
+    DCHECK((std::is_same<Isolate, v8::internal::Isolate>::value));
     outer_scope = scope->outer_scope_->scope_info_;
   }
 
@@ -2540,11 +2550,15 @@ void DeclarationScope::AllocateScopeInfos(ParseInfo* info, Isolate* isolate) {
   // Ensuring that the outer script scope has a scope info avoids having
   // special case for native contexts vs other contexts.
   if (info->script_scope() && info->script_scope()->scope_info_.is_null()) {
-    info->script_scope()->scope_info_ =
-        handle(ScopeInfo::Empty(isolate), isolate);
+    info->script_scope()->scope_info_ = isolate->factory()->empty_scope_info();
   }
 }
 
+template V8_EXPORT_PRIVATE void DeclarationScope::AllocateScopeInfos<Isolate>(
+    ParseInfo* info, Isolate* isolate);
+template V8_EXPORT_PRIVATE void DeclarationScope::AllocateScopeInfos<
+    OffThreadIsolate>(ParseInfo* info, OffThreadIsolate* isolate);
+
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   Variable* function =
@@ -2655,7 +2669,7 @@ Variable* ClassScope::LookupPrivateNameInScopeInfo(const AstRawString* name) {
   DCHECK_NULL(LookupLocalPrivateName(name));
   DisallowHeapAllocation no_gc;
 
-  String name_handle = *name->string().get<Factory>();
+  String name_handle = *name->string();
   VariableMode mode;
   InitializationFlag init_flag;
   MaybeAssignedFlag maybe_assigned_flag;
diff --git a/deps/v8/src/ast/scopes.h b/deps/v8/src/ast/scopes.h
index 4955c5902b..08bbc696d9 100644
--- a/deps/v8/src/ast/scopes.h
+++ b/deps/v8/src/ast/scopes.h
@@ -645,9 +645,9 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
                                     bool force_context_allocation);
   static void ResolvePreparsedVariable(VariableProxy* proxy, Scope* scope,
                                        Scope* end);
-  void ResolveTo(ParseInfo* info, VariableProxy* proxy, Variable* var);
-  void ResolveVariable(ParseInfo* info, VariableProxy* proxy);
-  V8_WARN_UNUSED_RESULT bool ResolveVariablesRecursively(ParseInfo* info);
+  void ResolveTo(VariableProxy* proxy, Variable* var);
+  void ResolveVariable(VariableProxy* proxy);
+  V8_WARN_UNUSED_RESULT bool ResolveVariablesRecursively(Scope* end);
 
   // Finds free variables of this scope. This mutates the unresolved variables
   // list along the way, so full resolution cannot be done afterwards.
@@ -656,7 +656,7 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
                         UnresolvedList* new_unresolved_list,
                         bool maybe_in_arrowhead);
   void CollectNonLocals(DeclarationScope* max_outer_scope, Isolate* isolate,
-                        ParseInfo* info, Handle<StringSet>* non_locals);
+                        Handle<StringSet>* non_locals);
 
   // Predicates.
   bool MustAllocate(Variable* var);
@@ -670,7 +670,8 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
   V8_INLINE void AllocateNonParameterLocalsAndDeclaredGlobals();
   void AllocateVariablesRecursively();
 
-  void AllocateScopeInfosRecursively(Isolate* isolate,
+  template <typename LocalIsolate>
+  void AllocateScopeInfosRecursively(LocalIsolate* isolate,
                                      MaybeHandle<ScopeInfo> outer_scope);
 
   void AllocateDebuggerScopeInfos(Isolate* isolate,
@@ -691,6 +692,8 @@ class V8_EXPORT_PRIVATE Scope : public NON_EXPORTED_BASE(ZoneObject) {
 
   void SetDefaults();
 
+  void set_scope_info(Handle<ScopeInfo> scope_info);
+
   friend class DeclarationScope;
   friend class ClassScope;
   friend class ScopeTestHelper;
@@ -1098,9 +1101,11 @@ class V8_EXPORT_PRIVATE DeclarationScope : public Scope {
 
   // Allocate ScopeInfos for top scope and any inner scopes that need them.
   // Does nothing if ScopeInfo is already allocated.
-  static void AllocateScopeInfos(ParseInfo* info, Isolate* isolate);
+  template <typename LocalIsolate>
+  V8_EXPORT_PRIVATE static void AllocateScopeInfos(ParseInfo* info,
+                                                   LocalIsolate* isolate);
 
-  Handle<StringSet> CollectNonLocals(Isolate* isolate, ParseInfo* info,
+  Handle<StringSet> CollectNonLocals(Isolate* isolate,
                                      Handle<StringSet> non_locals);
 
   // Determine if we can use lazy compilation for this scope.
diff --git a/deps/v8/src/ast/variables.h b/deps/v8/src/ast/variables.h
index 3a8ca8888f..a3a5199620 100644
--- a/deps/v8/src/ast/variables.h
+++ b/deps/v8/src/ast/variables.h
@@ -8,6 +8,7 @@
 #include "src/ast/ast-value-factory.h"
 #include "src/base/threaded-list.h"
 #include "src/common/globals.h"
+#include "src/execution/isolate.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
@@ -57,7 +58,7 @@ class Variable final : public ZoneObject {
   // parameter initializers.
   void set_scope(Scope* scope) { scope_ = scope; }
 
-  Handle<String> name() const { return name_->string().get<Factory>(); }
+  Handle<String> name() const { return name_->string(); }
   const AstRawString* raw_name() const { return name_; }
   VariableMode mode() const { return VariableModeField::decode(bit_field_); }
   void set_mode(VariableMode mode) {
diff --git a/deps/v8/src/base/address-region.h b/deps/v8/src/base/address-region.h
index 0f4809f9e8..9ef6160d2a 100644
--- a/deps/v8/src/base/address-region.h
+++ b/deps/v8/src/base/address-region.h
@@ -66,6 +66,16 @@ class AddressRegion {
 };
 ASSERT_TRIVIALLY_COPYABLE(AddressRegion);
 
+// Construct an AddressRegion from anything providing a {data()} and {size()}
+// accessor.
+template <typename Container,
+          typename = decltype(std::declval<Container>().data()),
+          typename = decltype(std::declval<Container>().size())>
+inline constexpr AddressRegion AddressRegionOf(Container&& c) {
+  return AddressRegion{reinterpret_cast<AddressRegion::Address>(c.data()),
+                       sizeof(*c.data()) * c.size()};
+}
+
 inline std::ostream& operator<<(std::ostream& out, AddressRegion region) {
   return out << "[" << reinterpret_cast<void*>(region.begin()) << "+"
              << region.size() << "]";
diff --git a/deps/v8/src/base/atomic-utils.h b/deps/v8/src/base/atomic-utils.h
index 7b6bd85155..5d51510e3c 100644
--- a/deps/v8/src/base/atomic-utils.h
+++ b/deps/v8/src/base/atomic-utils.h
@@ -105,6 +105,16 @@ class AsAtomicImpl {
   }
 
   template <typename T>
+  static T Relaxed_CompareAndSwap(
+      T* addr, typename std::remove_reference<T>::type old_value,
+      typename std::remove_reference<T>::type new_value) {
+    STATIC_ASSERT(sizeof(T) <= sizeof(AtomicStorageType));
+    return cast_helper<T>::to_return_type(base::Relaxed_CompareAndSwap(
+        to_storage_addr(addr), cast_helper<T>::to_storage_type(old_value),
+        cast_helper<T>::to_storage_type(new_value)));
+  }
+
+  template <typename T>
   static T AcquireRelease_CompareAndSwap(
       T* addr, typename std::remove_reference<T>::type old_value,
       typename std::remove_reference<T>::type new_value) {
@@ -120,13 +130,14 @@ class AsAtomicImpl {
   static bool SetBits(T* addr, T bits, T mask) {
     STATIC_ASSERT(sizeof(T) <= sizeof(AtomicStorageType));
     DCHECK_EQ(bits & ~mask, static_cast<T>(0));
-    T old_value;
-    T new_value;
+    T old_value = Relaxed_Load(addr);
+    T new_value, old_value_before_cas;
     do {
-      old_value = Relaxed_Load(addr);
       if ((old_value & mask) == bits) return false;
       new_value = (old_value & ~mask) | bits;
-    } while (Release_CompareAndSwap(addr, old_value, new_value) != old_value);
+      old_value_before_cas = old_value;
+      old_value = Release_CompareAndSwap(addr, old_value, new_value);
+    } while (old_value != old_value_before_cas);
     return true;
   }
 
@@ -192,6 +203,16 @@ inline void CheckedDecrement(std::atomic<T>* number, T amount) {
   USE(old);
 }
 
+template <typename T>
+V8_INLINE std::atomic<T>* AsAtomicPtr(T* t) {
+  return reinterpret_cast<std::atomic<T>*>(t);
+}
+
+template <typename T>
+V8_INLINE const std::atomic<T>* AsAtomicPtr(const T* t) {
+  return reinterpret_cast<const std::atomic<T>*>(t);
+}
+
 }  // namespace base
 }  // namespace v8
 
diff --git a/deps/v8/src/base/atomicops.h b/deps/v8/src/base/atomicops.h
index 35b2732949..11c41545ab 100644
--- a/deps/v8/src/base/atomicops.h
+++ b/deps/v8/src/base/atomicops.h
@@ -57,77 +57,66 @@ using Atomic64 = intptr_t;
 using AtomicWord = intptr_t;
 
 // Atomically execute:
-//      result = *ptr;
-//      if (*ptr == old_value)
-//        *ptr = new_value;
-//      return result;
+//   result = *ptr;
+//   if (result == old_value)
+//     *ptr = new_value;
+//   return result;
 //
-// I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
-// Always return the old value of "*ptr"
-//
-// This routine implies no memory barriers.
+// I.e. replace |*ptr| with |new_value| if |*ptr| used to be |old_value|.
+// Always return the value of |*ptr| before the operation.
+// Acquire, Relaxed, Release correspond to standard C++ memory orders.
 Atomic16 Relaxed_CompareAndSwap(volatile Atomic16* ptr, Atomic16 old_value,
                                 Atomic16 new_value);
+Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
+                                Atomic32 new_value);
+Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
+                                       Atomic32 old_value, Atomic32 new_value);
 Atomic32 Relaxed_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
                                 Atomic32 new_value);
+Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, Atomic32 old_value,
+                                Atomic32 new_value);
+#ifdef V8_HOST_ARCH_64_BIT
+Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
+                                Atomic64 new_value);
+Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value, Atomic64 new_value);
+Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
+                                Atomic64 new_value);
+Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
+                                Atomic64 new_value);
+#endif  // V8_HOST_ARCH_64_BIT
 
-// Atomically store new_value into *ptr, returning the previous value held in
-// *ptr.  This routine implies no memory barriers.
+// Atomically store new_value into |*ptr|, returning the previous value held in
+// |*ptr|.
 Atomic32 Relaxed_AtomicExchange(volatile Atomic32* ptr, Atomic32 new_value);
+#ifdef V8_HOST_ARCH_64_BIT
+Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr, Atomic64 new_value);
+#endif  // V8_HOST_ARCH_64_BIT
 
-// Atomically increment *ptr by "increment".  Returns the new value of
-// *ptr with the increment applied.  This routine implies no memory barriers.
+// Atomically increment |*ptr| by |increment|. Returns the new value of
+// |*ptr| with the increment applied.
 Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr, Atomic32 increment);
 
-Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
-                                 Atomic32 increment);
-
-// These following lower-level operations are typically useful only to people
-// implementing higher-level synchronization operations like spinlocks,
-// mutexes, and condition-variables.  They combine CompareAndSwap(), a load,
-// or a store with appropriate memory-ordering instructions.  "Acquire"
-// operations ensure that no later memory access can be reordered ahead of the
-// operation. "Release" operations ensure that no previous memory access can
-// be reordered after the operation.  "Fence" operations have both "Acquire"
-// and "Release" semantics. A SeqCst_MemoryFence() has "Fence" semantics, but
-// does no memory access.
-Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
-                                Atomic32 old_value,
-                                Atomic32 new_value);
-Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
-                                Atomic32 old_value,
-                                Atomic32 new_value);
-Atomic32 AcquireRelease_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value, Atomic32 new_value);
+#ifdef V8_HOST_ARCH_64_BIT
+Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
+#endif  // V8_HOST_ARCH_64_BIT
 
 void SeqCst_MemoryFence();
+
 void Relaxed_Store(volatile Atomic8* ptr, Atomic8 value);
 void Relaxed_Store(volatile Atomic16* ptr, Atomic16 value);
 void Relaxed_Store(volatile Atomic32* ptr, Atomic32 value);
 void Release_Store(volatile Atomic32* ptr, Atomic32 value);
+#ifdef V8_HOST_ARCH_64_BIT
+void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value);
+void Release_Store(volatile Atomic64* ptr, Atomic64 value);
+#endif  // V8_HOST_ARCH_64_BIT
 
 Atomic8 Relaxed_Load(volatile const Atomic8* ptr);
 Atomic16 Relaxed_Load(volatile const Atomic16* ptr);
 Atomic32 Relaxed_Load(volatile const Atomic32* ptr);
 Atomic32 Acquire_Load(volatile const Atomic32* ptr);
-
-// 64-bit atomic operations (only available on 64-bit processors).
 #ifdef V8_HOST_ARCH_64_BIT
-Atomic64 Relaxed_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 Relaxed_AtomicExchange(volatile Atomic64* ptr, Atomic64 new_value);
-Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
-Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
-
-Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
-                                Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr, Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 AcquireRelease_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value, Atomic64 new_value);
-void Relaxed_Store(volatile Atomic64* ptr, Atomic64 value);
-void Release_Store(volatile Atomic64* ptr, Atomic64 value);
 Atomic64 Relaxed_Load(volatile const Atomic64* ptr);
 Atomic64 Acquire_Load(volatile const Atomic64* ptr);
 #endif  // V8_HOST_ARCH_64_BIT
diff --git a/deps/v8/src/base/atomicops_internals_atomicword_compat.h b/deps/v8/src/base/atomicops_internals_atomicword_compat.h
index 7deacf2f45..5ed7d5594e 100644
--- a/deps/v8/src/base/atomicops_internals_atomicword_compat.h
+++ b/deps/v8/src/base/atomicops_internals_atomicword_compat.h
@@ -42,12 +42,6 @@ inline AtomicWord Relaxed_AtomicIncrement(volatile AtomicWord* ptr,
                                  increment);
 }
 
-inline AtomicWord Barrier_AtomicIncrement(volatile AtomicWord* ptr,
-                                          AtomicWord increment) {
-  return Barrier_AtomicIncrement(
-      reinterpret_cast<volatile Atomic32*>(ptr), increment);
-}
-
 inline AtomicWord Acquire_CompareAndSwap(volatile AtomicWord* ptr,
                                          AtomicWord old_value,
                                          AtomicWord new_value) {
diff --git a/deps/v8/src/base/atomicops_internals_portable.h b/deps/v8/src/base/atomicops_internals_portable.h
index 068c1e87ff..1f89f0a6b3 100644
--- a/deps/v8/src/base/atomicops_internals_portable.h
+++ b/deps/v8/src/base/atomicops_internals_portable.h
@@ -74,11 +74,6 @@ inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
   return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_RELAXED);
 }
 
-inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
-                                        Atomic32 increment) {
-  return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_SEQ_CST);
-}
-
 inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
                                        Atomic32 old_value, Atomic32 new_value) {
   __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
@@ -160,11 +155,6 @@ inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
   return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_RELAXED);
 }
 
-inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
-                                        Atomic64 increment) {
-  return increment + __atomic_fetch_add(ptr, increment, __ATOMIC_SEQ_CST);
-}
-
 inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
                                        Atomic64 old_value, Atomic64 new_value) {
   __atomic_compare_exchange_n(ptr, &old_value, new_value, false,
diff --git a/deps/v8/src/base/atomicops_internals_std.h b/deps/v8/src/base/atomicops_internals_std.h
index c04e64bb32..8ea1019202 100644
--- a/deps/v8/src/base/atomicops_internals_std.h
+++ b/deps/v8/src/base/atomicops_internals_std.h
@@ -57,13 +57,6 @@ inline Atomic32 Relaxed_AtomicIncrement(volatile Atomic32* ptr,
                                                     std::memory_order_relaxed);
 }
 
-inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
-                                        Atomic32 increment) {
-  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
-                                                    increment,
-                                                    std::memory_order_seq_cst);
-}
-
 inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
                                        Atomic32 old_value, Atomic32 new_value) {
   atomic_compare_exchange_strong_explicit(
@@ -161,13 +154,6 @@ inline Atomic64 Relaxed_AtomicIncrement(volatile Atomic64* ptr,
                                                     std::memory_order_relaxed);
 }
 
-inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
-                                        Atomic64 increment) {
-  return increment + std::atomic_fetch_add_explicit(helper::to_std_atomic(ptr),
-                                                    increment,
-                                                    std::memory_order_seq_cst);
-}
-
 inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
                                        Atomic64 old_value, Atomic64 new_value) {
   std::atomic_compare_exchange_strong_explicit(
diff --git a/deps/v8/src/base/bits-iterator.h b/deps/v8/src/base/bits-iterator.h
new file mode 100644
index 0000000000..6ce656e6d7
--- /dev/null
+++ b/deps/v8/src/base/bits-iterator.h
@@ -0,0 +1,58 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_BITS_ITERATOR_H_
+#define V8_BASE_BITS_ITERATOR_H_
+
+#include <type_traits>
+
+#include "src/base/bits.h"
+#include "src/base/iterator.h"
+
+namespace v8 {
+namespace base {
+namespace bits {
+
+template <typename T, bool kMSBFirst = false>
+class BitsIterator : public iterator<std::forward_iterator_tag, int> {
+  STATIC_ASSERT(std::is_integral<T>::value);
+
+ public:
+  explicit BitsIterator(T bits) : bits_(bits) {}
+
+  int operator*() const {
+    return kMSBFirst ? 8 * sizeof(T) - 1 - CountLeadingZeros(bits_)
+                     : CountTrailingZeros(bits_);
+  }
+
+  BitsIterator& operator++() {
+    bits_ &= ~(T{1} << **this);
+    return *this;
+  }
+
+  bool operator==(BitsIterator other) { return bits_ == other.bits_; }
+  bool operator!=(BitsIterator other) { return bits_ != other.bits_; }
+
+ private:
+  T bits_;
+};
+
+// Returns an iterable over the bits in {bits}, from LSB to MSB.
+template <typename T>
+auto IterateBits(T bits) {
+  return make_iterator_range(BitsIterator<T>{bits}, BitsIterator<T>{0});
+}
+
+// Returns an iterable over the bits in {bits}, from MSB to LSB.
+template <typename T>
+auto IterateBitsBackwards(T bits) {
+  return make_iterator_range(BitsIterator<T, true>{bits},
+                             BitsIterator<T, true>{0});
+}
+
+}  // namespace bits
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_BITS_ITERATOR_H_
diff --git a/deps/v8/src/base/build_config.h b/deps/v8/src/base/build_config.h
index f4300824eb..8d142c456c 100644
--- a/deps/v8/src/base/build_config.h
+++ b/deps/v8/src/base/build_config.h
@@ -33,13 +33,12 @@
 #elif defined(__MIPSEB__) || defined(__MIPSEL__)
 #define V8_HOST_ARCH_MIPS 1
 #define V8_HOST_ARCH_32_BIT 1
+#elif defined(__PPC64__) || defined(_ARCH_PPC64)
+#define V8_HOST_ARCH_PPC64 1
+#define V8_HOST_ARCH_64_BIT 1
 #elif defined(__PPC__) || defined(_ARCH_PPC)
 #define V8_HOST_ARCH_PPC 1
-#if defined(__PPC64__) || defined(_ARCH_PPC64)
-#define V8_HOST_ARCH_64_BIT 1
-#else
 #define V8_HOST_ARCH_32_BIT 1
-#endif
 #elif defined(__s390__) || defined(__s390x__)
 #define V8_HOST_ARCH_S390 1
 #if defined(__s390x__)
@@ -78,7 +77,7 @@
 // environment as presented by the compiler.
 #if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM &&      \
     !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && !V8_TARGET_ARCH_MIPS64 && \
-    !V8_TARGET_ARCH_PPC && !V8_TARGET_ARCH_S390
+    !V8_TARGET_ARCH_PPC && !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390
 #if defined(_M_X64) || defined(__x86_64__)
 #define V8_TARGET_ARCH_X64 1
 #elif defined(_M_IX86) || defined(__i386__)
@@ -91,6 +90,8 @@
 #define V8_TARGET_ARCH_MIPS64 1
 #elif defined(__MIPSEB__) || defined(__MIPSEL__)
 #define V8_TARGET_ARCH_MIPS 1
+#elif defined(_ARCH_PPC64)
+#define V8_TARGET_ARCH_PPC64 1
 #elif defined(_ARCH_PPC)
 #define V8_TARGET_ARCH_PPC 1
 #else
@@ -118,11 +119,9 @@
 #elif V8_TARGET_ARCH_MIPS64
 #define V8_TARGET_ARCH_64_BIT 1
 #elif V8_TARGET_ARCH_PPC
-#if V8_TARGET_ARCH_PPC64
-#define V8_TARGET_ARCH_64_BIT 1
-#else
 #define V8_TARGET_ARCH_32_BIT 1
-#endif
+#elif V8_TARGET_ARCH_PPC64
+#define V8_TARGET_ARCH_64_BIT 1
 #elif V8_TARGET_ARCH_S390
 #if V8_TARGET_ARCH_S390X
 #define V8_TARGET_ARCH_64_BIT 1
diff --git a/deps/v8/src/base/cpu.cc b/deps/v8/src/base/cpu.cc
index 4f4ac2b328..f1c48fa135 100644
--- a/deps/v8/src/base/cpu.cc
+++ b/deps/v8/src/base/cpu.cc
@@ -9,7 +9,6 @@
 #endif
 #if V8_OS_LINUX
 #include <linux/auxvec.h>  // AT_HWCAP
-extern "C" char** environ;
 #endif
 #if V8_GLIBC_PREREQ(2, 16)
 #include <sys/auxv.h>  // getauxval()
@@ -17,7 +16,7 @@ extern "C" char** environ;
 #if V8_OS_QNX
 #include <sys/syspage.h>  // cpuinfo
 #endif
-#if (V8_OS_LINUX && V8_HOST_ARCH_PPC) || V8_OS_ANDROID
+#if V8_OS_LINUX && (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64)
 #include <elf.h>
 #endif
 #if V8_OS_AIX
@@ -110,25 +109,31 @@ static V8_INLINE void __cpuid(int cpu_info[4], int info_type) {
 #define HWCAP_LPAE  (1 << 20)
 
 static uint32_t ReadELFHWCaps() {
+  uint32_t result = 0;
 #if V8_GLIBC_PREREQ(2, 16)
-  return static_cast<uint32_t>(getauxval(AT_HWCAP));
-#else
-  char** head = environ;
-  while (*head++ != nullptr) {
-  }
-#ifdef __LP64__
-  using elf_auxv_t = Elf64_auxv_t;
+  result = static_cast<uint32_t>(getauxval(AT_HWCAP));
 #else
-  using elf_auxv_t = Elf32_auxv_t;
-#endif
-  for (elf_auxv_t* entry = reinterpret_cast<elf_auxv_t*>(head);
-       entry->a_type != AT_NULL; ++entry) {
-    if (entry->a_type == AT_HWCAP) {
-      return entry->a_un.a_val;
+  // Read the ELF HWCAP flags by parsing /proc/self/auxv.
+  FILE* fp = fopen("/proc/self/auxv", "r");
+  if (fp != nullptr) {
+    struct {
+      uint32_t tag;
+      uint32_t value;
+    } entry;
+    for (;;) {
+      size_t n = fread(&entry, sizeof(entry), 1, fp);
+      if (n == 0 || (entry.tag == 0 && entry.value == 0)) {
+        break;
+      }
+      if (entry.tag == AT_HWCAP) {
+        result = entry.value;
+        break;
+      }
     }
+    fclose(fp);
   }
-  return 0u;
 #endif
+  return result;
 }
 
 #endif  // V8_HOST_ARCH_ARM
@@ -602,32 +607,37 @@ CPU::CPU()
 #elif V8_HOST_ARCH_ARM64
 // Implementer, variant and part are currently unused under ARM64.
 
-#elif V8_HOST_ARCH_PPC
+#elif V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64
 
 #ifndef USE_SIMULATOR
 #if V8_OS_LINUX
+  // Read processor info from /proc/self/auxv.
   char* auxv_cpu_type = nullptr;
-  char** head = environ;
-  while (*head++ != nullptr) {
-  }
+  FILE* fp = fopen("/proc/self/auxv", "r");
+  if (fp != nullptr) {
 #if V8_TARGET_ARCH_PPC64
-  using elf_auxv_t = Elf64_auxv_t;
+    Elf64_auxv_t entry;
 #else
-  using elf_auxv_t = Elf32_auxv_t;
+    Elf32_auxv_t entry;
 #endif
-  for (elf_auxv_t* entry = reinterpret_cast<elf_auxv_t*>(head);
-       entry->a_type != AT_NULL; ++entry) {
-    switch (entry->a_type) {
-      case AT_PLATFORM:
-        auxv_cpu_type = reinterpret_cast<char*>(entry->a_un.a_val);
-        break;
-      case AT_ICACHEBSIZE:
-        icache_line_size_ = entry->a_un.a_val;
-        break;
-      case AT_DCACHEBSIZE:
-        dcache_line_size_ = entry->a_un.a_val;
+    for (;;) {
+      size_t n = fread(&entry, sizeof(entry), 1, fp);
+      if (n == 0 || entry.a_type == AT_NULL) {
         break;
+      }
+      switch (entry.a_type) {
+        case AT_PLATFORM:
+          auxv_cpu_type = reinterpret_cast<char*>(entry.a_un.a_val);
+          break;
+        case AT_ICACHEBSIZE:
+          icache_line_size_ = entry.a_un.a_val;
+          break;
+        case AT_DCACHEBSIZE:
+          dcache_line_size_ = entry.a_un.a_val;
+          break;
+      }
     }
+    fclose(fp);
   }
 
   part_ = -1;
@@ -671,7 +681,7 @@ CPU::CPU()
   }
 #endif  // V8_OS_AIX
 #endif  // !USE_SIMULATOR
-#endif  // V8_HOST_ARCH_PPC
+#endif  // V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64
 }
 
 }  // namespace base
diff --git a/deps/v8/src/base/enum-set.h b/deps/v8/src/base/enum-set.h
index ef7f0df9bd..927a8f87fe 100644
--- a/deps/v8/src/base/enum-set.h
+++ b/deps/v8/src/base/enum-set.h
@@ -29,32 +29,43 @@ class EnumSet {
 
   bool empty() const { return bits_ == 0; }
   bool contains(E element) const { return (bits_ & Mask(element)) != 0; }
-  bool contains_any(const EnumSet& set) const {
-    return (bits_ & set.bits_) != 0;
-  }
+  bool contains_any(EnumSet set) const { return (bits_ & set.bits_) != 0; }
   void Add(E element) { bits_ |= Mask(element); }
-  void Add(const EnumSet& set) { bits_ |= set.bits_; }
+  void Add(EnumSet set) { bits_ |= set.bits_; }
   void Remove(E element) { bits_ &= ~Mask(element); }
-  void Remove(const EnumSet& set) { bits_ &= ~set.bits_; }
+  void Remove(EnumSet set) { bits_ &= ~set.bits_; }
   void RemoveAll() { bits_ = 0; }
-  void Intersect(const EnumSet& set) { bits_ &= set.bits_; }
+  void Intersect(EnumSet set) { bits_ &= set.bits_; }
   T ToIntegral() const { return bits_; }
-  bool operator==(const EnumSet& set) const { return bits_ == set.bits_; }
-  bool operator!=(const EnumSet& set) const { return bits_ != set.bits_; }
-  EnumSet operator|(const EnumSet& set) const {
-    return EnumSet(bits_ | set.bits_);
-  }
-  EnumSet operator&(const EnumSet& set) const {
-    return EnumSet(bits_ & set.bits_);
-  }
+
+  bool operator==(EnumSet set) const { return bits_ == set.bits_; }
+  bool operator!=(EnumSet set) const { return bits_ != set.bits_; }
+
+  EnumSet operator|(EnumSet set) const { return EnumSet(bits_ | set.bits_); }
+  EnumSet operator&(EnumSet set) const { return EnumSet(bits_ & set.bits_); }
+  EnumSet operator-(EnumSet set) const { return EnumSet(bits_ & ~set.bits_); }
+
+  EnumSet& operator|=(EnumSet set) { return *this = *this | set; }
+  EnumSet& operator&=(EnumSet set) { return *this = *this & set; }
+  EnumSet& operator-=(EnumSet set) { return *this = *this - set; }
+
+  EnumSet operator|(E element) const { return EnumSet(bits_ | Mask(element)); }
+  EnumSet operator&(E element) const { return EnumSet(bits_ & Mask(element)); }
+  EnumSet operator-(E element) const { return EnumSet(bits_ & ~Mask(element)); }
+
+  EnumSet& operator|=(E element) { return *this = *this | element; }
+  EnumSet& operator&=(E element) { return *this = *this & element; }
+  EnumSet& operator-=(E element) { return *this = *this - element; }
 
   static constexpr EnumSet FromIntegral(T bits) { return EnumSet{bits}; }
 
  private:
   explicit constexpr EnumSet(T bits) : bits_(bits) {}
 
-  static T Mask(E element) {
+  static constexpr T Mask(E element) {
+#if V8_HAS_CXX14_CONSTEXPR
     DCHECK_GT(sizeof(T) * 8, static_cast<int>(element));
+#endif
     return T{1} << static_cast<typename std::underlying_type<E>::type>(element);
   }
 
diff --git a/deps/v8/src/base/macros.h b/deps/v8/src/base/macros.h
index 5f52a9893e..e22dd00895 100644
--- a/deps/v8/src/base/macros.h
+++ b/deps/v8/src/base/macros.h
@@ -144,11 +144,11 @@ V8_INLINE Dest bit_cast(Source const& source) {
 // Extract from 3.2.2 of C++11 spec:
 //  [...] A non-placement deallocation function for a class is
 //  odr-used by the definition of the destructor of that class, [...]
-#define DISALLOW_NEW_AND_DELETE()                            \
-  void* operator new(size_t) { base::OS::Abort(); }          \
-  void* operator new[](size_t) { base::OS::Abort(); }        \
-  void operator delete(void*, size_t) { base::OS::Abort(); } \
-  void operator delete[](void*, size_t) { base::OS::Abort(); }
+#define DISALLOW_NEW_AND_DELETE()                                \
+  void* operator new(size_t) { v8::base::OS::Abort(); }          \
+  void* operator new[](size_t) { v8::base::OS::Abort(); }        \
+  void operator delete(void*, size_t) { v8::base::OS::Abort(); } \
+  void operator delete[](void*, size_t) { v8::base::OS::Abort(); }
 
 // Define V8_USE_ADDRESS_SANITIZER macro.
 #if defined(__has_feature)
diff --git a/deps/v8/src/base/platform/platform-freebsd.cc b/deps/v8/src/base/platform/platform-freebsd.cc
index 8d63dd2f84..3c0b2d1d1a 100644
--- a/deps/v8/src/base/platform/platform-freebsd.cc
+++ b/deps/v8/src/base/platform/platform-freebsd.cc
@@ -96,5 +96,23 @@ void OS::SignalCodeMovingGC() {}
 
 void OS::AdjustSchedulingParams() {}
 
+// static
+void* Stack::GetStackStart() {
+  pthread_attr_t attr;
+  int error;
+  pthread_attr_init(&attr);
+  error = pthread_attr_get_np(pthread_self(), &attr);
+  if (!error) {
+    void* base;
+    size_t size;
+    error = pthread_attr_getstack(&attr, &base, &size);
+    CHECK(!error);
+    pthread_attr_destroy(&attr);
+    return reinterpret_cast<uint8_t*>(base) + size;
+  }
+  pthread_attr_destroy(&attr);
+  return nullptr;
+}
+
 }  // namespace base
 }  // namespace v8
diff --git a/deps/v8/src/base/platform/platform-macos.cc b/deps/v8/src/base/platform/platform-macos.cc
index 72a41c8491..bee6b30f7c 100644
--- a/deps/v8/src/base/platform/platform-macos.cc
+++ b/deps/v8/src/base/platform/platform-macos.cc
@@ -93,5 +93,10 @@ void OS::AdjustSchedulingParams() {
 #endif
 }
 
+// static
+void* Stack::GetStackStart() {
+  return pthread_get_stackaddr_np(pthread_self());
+}
+
 }  // namespace base
 }  // namespace v8
diff --git a/deps/v8/src/base/platform/platform-posix.cc b/deps/v8/src/base/platform/platform-posix.cc
index 0424d4c135..1e600c7891 100644
--- a/deps/v8/src/base/platform/platform-posix.cc
+++ b/deps/v8/src/base/platform/platform-posix.cc
@@ -81,6 +81,10 @@ extern int madvise(caddr_t, size_t, int);
 #define MADV_FREE MADV_DONTNEED
 #endif
 
+#if defined(V8_LIBC_GLIBC)
+extern "C" void* __libc_stack_end;  // NOLINT
+#endif
+
 namespace v8 {
 namespace base {
 
@@ -109,6 +113,8 @@ const int kMmapFd = -1;
 
 const int kMmapFdOffset = 0;
 
+// TODO(v8:10026): Add the right permission flag to make executable pages
+// guarded.
 int GetProtectionFromMemoryPermission(OS::MemoryPermission access) {
   switch (access) {
     case OS::MemoryPermission::kNoAccess:
@@ -464,7 +470,7 @@ void OS::DebugBreak() {
   asm("break");
 #elif V8_HOST_ARCH_MIPS64
   asm("break");
-#elif V8_HOST_ARCH_PPC
+#elif V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64
   asm("twge 2,2");
 #elif V8_HOST_ARCH_IA32
   asm("int $3");
@@ -802,7 +808,7 @@ static void* ThreadEntry(void* arg) {
 
 
 void Thread::set_name(const char* name) {
-  strncpy(name_, name, sizeof(name_));
+  strncpy(name_, name, sizeof(name_) - 1);
   name_[sizeof(name_) - 1] = '\0';
 }
 
@@ -961,6 +967,40 @@ void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
   USE(result);
 }
 
+// pthread_getattr_np used below is non portable (hence the _np suffix). We
+// keep this version in POSIX as most Linux-compatible derivatives will
+// support it. MacOS and FreeBSD are different here.
+#if !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX)
+
+// static
+void* Stack::GetStackStart() {
+  pthread_attr_t attr;
+  int error = pthread_getattr_np(pthread_self(), &attr);
+  if (!error) {
+    void* base;
+    size_t size;
+    error = pthread_attr_getstack(&attr, &base, &size);
+    CHECK(!error);
+    pthread_attr_destroy(&attr);
+    return reinterpret_cast<uint8_t*>(base) + size;
+  }
+  pthread_attr_destroy(&attr);
+
+#if defined(V8_LIBC_GLIBC)
+  // pthread_getattr_np can fail for the main thread. In this case
+  // just like NaCl we rely on the __libc_stack_end to give us
+  // the start of the stack.
+  // See https://code.google.com/p/nativeclient/issues/detail?id=3431.
+  return __libc_stack_end;
+#endif  // !defined(V8_LIBC_GLIBC)
+  return nullptr;
+}
+
+#endif  // !defined(V8_OS_FREEBSD) && !defined(V8_OS_MACOSX)
+
+// static
+void* Stack::GetCurrentStackPosition() { return __builtin_frame_address(0); }
+
 #undef LOG_TAG
 #undef MAP_ANONYMOUS
 #undef MADV_FREE
diff --git a/deps/v8/src/base/platform/platform-win32.cc b/deps/v8/src/base/platform/platform-win32.cc
index 04ef8a30f2..5db3e34310 100644
--- a/deps/v8/src/base/platform/platform-win32.cc
+++ b/deps/v8/src/base/platform/platform-win32.cc
@@ -1394,5 +1394,31 @@ void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
 
 void OS::AdjustSchedulingParams() {}
 
+// static
+void* Stack::GetStackStart() {
+#if defined(V8_TARGET_ARCH_X64)
+  return reinterpret_cast<void*>(__readgsqword(offsetof(NT_TIB64, StackBase)));
+#elif defined(V8_TARGET_ARCH_32_BIT)
+  return reinterpret_cast<void*>(__readfsdword(offsetof(NT_TIB, StackBase)));
+#elif defined(V8_TARGET_ARCH_ARM64)
+  // Windows 8 and later, see
+  // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentthreadstacklimits
+  ULONG_PTR lowLimit, highLimit;
+  ::GetCurrentThreadStackLimits(&lowLimit, &highLimit);
+  return reinterpret_cast<void*>(highLimit);
+#else
+#error Unsupported GetStackStart.
+#endif
+}
+
+// static
+void* Stack::GetCurrentStackPosition() {
+#if V8_CC_MSVC
+  return _AddressOfReturnAddress();
+#else
+  return __builtin_frame_address(0);
+#endif
+}
+
 }  // namespace base
 }  // namespace v8
diff --git a/deps/v8/src/base/platform/platform.h b/deps/v8/src/base/platform/platform.h
index e1f84043eb..af55036a00 100644
--- a/deps/v8/src/base/platform/platform.h
+++ b/deps/v8/src/base/platform/platform.h
@@ -35,6 +35,10 @@
 #include "src/base/qnx-math.h"
 #endif
 
+#ifdef V8_USE_ADDRESS_SANITIZER
+#include <sanitizer/asan_interface.h>
+#endif  // V8_USE_ADDRESS_SANITIZER
+
 namespace v8 {
 
 namespace base {
@@ -407,6 +411,38 @@ class V8_BASE_EXPORT Thread {
   DISALLOW_COPY_AND_ASSIGN(Thread);
 };
 
+// TODO(v8:10354): Make use of the stack utilities here in V8.
+class V8_BASE_EXPORT Stack {
+ public:
+  // Gets the start of the stack of the current thread.
+  static void* GetStackStart();
+
+  // Returns the current stack top. Works correctly with ASAN and SafeStack.
+  // GetCurrentStackPosition() should not be inlined, because it works on stack
+  // frames if it were inlined into a function with a huge stack frame it would
+  // return an address significantly above the actual current stack position.
+  static V8_NOINLINE void* GetCurrentStackPosition();
+
+  // Translates an ASAN-based slot to a real stack slot if necessary.
+  static void* GetStackSlot(void* slot) {
+#ifdef V8_USE_ADDRESS_SANITIZER
+    void* fake_stack = __asan_get_current_fake_stack();
+    if (fake_stack) {
+      void* fake_frame_start;
+      void* real_frame = __asan_addr_is_in_fake_stack(
+          fake_stack, slot, &fake_frame_start, nullptr);
+      if (real_frame) {
+        return reinterpret_cast<void*>(
+            reinterpret_cast<uintptr_t>(real_frame) +
+            (reinterpret_cast<uintptr_t>(slot) -
+             reinterpret_cast<uintptr_t>(fake_frame_start)));
+      }
+    }
+#endif  // V8_USE_ADDRESS_SANITIZER
+    return slot;
+  }
+};
+
 }  // namespace base
 }  // namespace v8
 
diff --git a/deps/v8/src/builtins/arm/builtins-arm.cc b/deps/v8/src/builtins/arm/builtins-arm.cc
index 93caa8847e..49f578d1fd 100644
--- a/deps/v8/src/builtins/arm/builtins-arm.cc
+++ b/deps/v8/src/builtins/arm/builtins-arm.cc
@@ -6,15 +6,15 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
@@ -22,6 +22,7 @@
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -65,10 +66,16 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void LoadStackLimit(MacroAssembler* masm, Register destination,
+                    StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -82,7 +89,7 @@ void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  LoadRealStackLimit(masm, scratch);
+  LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ sub(scratch, sp, scratch);
@@ -413,7 +420,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  LoadRealStackLimit(masm, scratch);
+  LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
   __ cmp(sp, scratch);
   __ b(lo, &stack_overflow);
 
@@ -926,18 +933,27 @@ static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register bytecode, Register scratch1,
-                                          Label* if_return) {
+                                          Register scratch2, Label* if_return) {
   Register bytecode_size_table = scratch1;
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch2;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+                     bytecode, original_bytecode_offset));
 
   __ Move(bytecode_size_table,
           ExternalReference::bytecode_size_table_address());
+  __ Move(original_bytecode_offset, bytecode_offset);
 
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode;
@@ -964,7 +980,7 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
 
   __ bind(&process_bytecode);
 
-// Bailout to the return label if this is a return bytecode.
+  // Bailout to the return label if this is a return bytecode.
 
   // Create cmp, cmpne, ..., cmpne to check for a return bytecode.
   Condition flag = al;
@@ -977,9 +993,22 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
 
   __ b(if_return, eq);
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ cmp(bytecode, Operand(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ b(ne, &not_jump_loop);
+  // We need to restore the original bytecode_offset since we might have
+  // increased it to skip the wide / extra-wide prefix bytecode.
+  __ Move(bytecode_offset, original_bytecode_offset);
+  __ b(&end);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
   __ ldr(scratch1, MemOperand(bytecode_size_table, bytecode, LSL, 2));
   __ add(bytecode_offset, bytecode_offset, scratch1);
+
+  __ bind(&end);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1085,7 +1114,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
     // Do a stack check to ensure we don't go over the limit.
     __ sub(r9, sp, Operand(r4));
-    LoadRealStackLimit(masm, r2);
+    LoadStackLimit(masm, r2, StackLimitKind::kRealStackLimit);
     __ cmp(r9, Operand(r2));
     __ b(lo, &stack_overflow);
 
@@ -1111,6 +1140,14 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ cmp(r9, Operand::Zero());
   __ str(r3, MemOperand(fp, r9, LSL, kPointerSizeLog2), ne);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  LoadStackLimit(masm, r4, StackLimitKind::kInterruptStackLimit);
+  __ cmp(sp, r4);
+  __ b(lo, &stack_check_interrupt);
+  __ bind(&after_stack_check_interrupt);
+
   // The accumulator is already loaded with undefined.
 
   // Load the dispatch table into a register and dispatch to the bytecode
@@ -1143,7 +1180,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ ldrb(r1, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r1, r2,
+                                kInterpreterBytecodeOffsetRegister, r1, r2, r3,
                                 &do_return);
   __ jmp(&do_dispatch);
 
@@ -1152,6 +1189,30 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r2);
   __ Jump(lr);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                              kFunctionEntryBytecodeOffset)));
+  __ str(kInterpreterBytecodeOffsetRegister,
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ ldr(kInterpreterBytecodeArrayRegister,
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(r4, kInterpreterBytecodeOffsetRegister);
+  __ str(r4, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1354,6 +1415,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmp(kInterpreterBytecodeOffsetRegister,
+           Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    __ b(ge, &okay);
+    __ bkpt(0);
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   UseScratchRegisterScope temps(masm);
   Register scratch = temps.Acquire();
@@ -1373,6 +1443,12 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ cmp(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                 kFunctionEntryBytecodeOffset));
+  __ b(eq, &function_entry_bytecode);
+
   // Load the current bytecode.
   __ ldrb(r1, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
@@ -1380,15 +1456,25 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   // Advance to the next bytecode.
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r1, r2,
+                                kInterpreterBytecodeOffsetRegister, r1, r2, r3,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(r2, kInterpreterBytecodeOffsetRegister);
   __ str(r2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ b(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -1994,7 +2080,8 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
 
         // Compute the space we have left. The stack might already be overflowed
         // here which will cause remaining_stack_size to become negative.
-        LoadRealStackLimit(masm, remaining_stack_size);
+        LoadStackLimit(masm, remaining_stack_size,
+                       StackLimitKind::kRealStackLimit);
         __ sub(remaining_stack_size, sp, remaining_stack_size);
 
         // Check if the arguments will overflow the stack.
@@ -2228,7 +2315,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // -----------------------------------
 
   Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
-  __ cmp(r2, Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+  __ cmp(r2, Operand(kDontAdaptArgumentsSentinel));
   __ b(eq, &dont_adapt_arguments);
   __ ldr(r4, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
   __ ldr(r4, FieldMemOperand(r4, SharedFunctionInfo::kFlagsOffset));
@@ -2433,6 +2520,35 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(r8);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    constexpr DwVfpRegister lowest_fp_reg = DwVfpRegister::from_code(
+        WasmDebugBreakFrameConstants::kFirstPushedFpReg);
+    constexpr DwVfpRegister highest_fp_reg = DwVfpRegister::from_code(
+        WasmDebugBreakFrameConstants::kLastPushedFpReg);
+
+    // Store gp parameter registers.
+    __ stm(db_w, sp, WasmDebugBreakFrameConstants::kPushedGpRegs);
+    // Store fp parameter registers.
+    __ vstm(db_w, sp, lowest_fp_reg, highest_fp_reg);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ vldm(ia_w, sp, lowest_fp_reg, highest_fp_reg);
+    __ ldm(ia_w, sp, WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
diff --git a/deps/v8/src/builtins/arm64/builtins-arm64.cc b/deps/v8/src/builtins/arm64/builtins-arm64.cc
index d4a4cbe0eb..9c38ae085e 100644
--- a/deps/v8/src/builtins/arm64/builtins-arm64.cc
+++ b/deps/v8/src/builtins/arm64/builtins-arm64.cc
@@ -6,15 +6,15 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
@@ -22,6 +22,7 @@
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 #if defined(V8_OS_WIN)
@@ -34,6 +35,8 @@ namespace internal {
 #define __ ACCESS_MASM(masm)
 
 void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address) {
+  __ CodeEntry();
+
   __ Mov(kJavaScriptCallExtraArg1Register, ExternalReference::Create(address));
   __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
           RelocInfo::CODE_TARGET);
@@ -65,10 +68,16 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void LoadStackLimit(MacroAssembler* masm, Register destination,
+                    StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -85,7 +94,7 @@ void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // We are not trying to catch interruptions (e.g. debug break and
   // preemption) here, so the "real stack limit" is checked.
 
-  LoadRealStackLimit(masm, scratch);
+  LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ Sub(scratch, sp, scratch);
@@ -465,7 +474,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  LoadRealStackLimit(masm, x10);
+  LoadStackLimit(masm, x10, StackLimitKind::kRealStackLimit);
   __ Cmp(sp, x10);
   __ B(lo, &stack_overflow);
 
@@ -689,10 +698,10 @@ void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
   // that.
   {
     Assembler::BlockPoolsScope block_pools(masm);
-    __ bind(&handler_entry);
 
     // Store the current pc as the handler offset. It's used later to create the
     // handler table.
+    __ BindExceptionHandler(&handler_entry);
     masm->isolate()->builtins()->SetJSEntryHandlerOffset(handler_entry.pos());
 
     // Caught exception: Store result (exception) in the pending exception
@@ -1049,17 +1058,26 @@ static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register bytecode, Register scratch1,
-                                          Label* if_return) {
+                                          Register scratch2, Label* if_return) {
   Register bytecode_size_table = scratch1;
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch2;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+                     bytecode, original_bytecode_offset));
 
   __ Mov(bytecode_size_table, ExternalReference::bytecode_size_table_address());
+  __ Mov(original_bytecode_offset, bytecode_offset);
 
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode, extra_wide;
@@ -1096,9 +1114,22 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ Cmp(bytecode, Operand(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ B(ne, &not_jump_loop);
+  // We need to restore the original bytecode_offset since we might have
+  // increased it to skip the wide / extra-wide prefix bytecode.
+  __ Mov(bytecode_offset, original_bytecode_offset);
+  __ B(&end);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
   __ Ldr(scratch1.W(), MemOperand(bytecode_size_table, bytecode, LSL, 2));
   __ Add(bytecode_offset, bytecode_offset, scratch1);
+
+  __ Bind(&end);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1180,7 +1211,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // the frame (that is done below).
   __ Bind(&push_stack_frame);
   FrameScope frame_scope(masm, StackFrame::MANUAL);
-  __ Push(lr, fp, cp, closure);
+  __ Push<TurboAssembler::kSignLR>(lr, fp, cp, closure);
   __ Add(fp, sp, StandardFrameConstants::kFixedFrameSizeFromFp);
 
   // Reset code age.
@@ -1213,7 +1244,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     {
       UseScratchRegisterScope temps(masm);
       Register scratch = temps.AcquireX();
-      LoadRealStackLimit(masm, scratch);
+      LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
       __ Cmp(x10, scratch);
     }
     __ B(lo, &stack_overflow);
@@ -1243,6 +1274,14 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Str(x3, MemOperand(fp, x10, LSL, kSystemPointerSizeLog2));
   __ Bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  LoadStackLimit(masm, x10, StackLimitKind::kInterruptStackLimit);
+  __ Cmp(sp, x10);
+  __ B(lo, &stack_check_interrupt);
+  __ Bind(&after_stack_check_interrupt);
+
   // The accumulator is already loaded with undefined.
 
   // Load the dispatch table into a register and dispatch to the bytecode
@@ -1274,7 +1313,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Ldrb(x1, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, x1, x2,
+                                kInterpreterBytecodeOffsetRegister, x1, x2, x3,
                                 &do_return);
   __ B(&do_dispatch);
 
@@ -1283,6 +1322,30 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, x2);
   __ Ret();
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ Mov(kInterpreterBytecodeOffsetRegister,
+         Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                              kFunctionEntryBytecodeOffset)));
+  __ Str(kInterpreterBytecodeOffsetRegister,
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ Ldr(kInterpreterBytecodeArrayRegister,
+         MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ Mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(x10, kInterpreterBytecodeOffsetRegister);
+  __ Str(x10, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1515,6 +1578,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister,
               MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmp(kInterpreterBytecodeOffsetRegister,
+           Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    __ B(ge, &okay);
+    __ Unreachable();
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   __ Ldrb(x23, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
@@ -1531,6 +1603,12 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister,
               MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ cmp(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                 kFunctionEntryBytecodeOffset));
+  __ B(eq, &function_entry_bytecode);
+
   // Load the current bytecode.
   __ Ldrb(x1, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
@@ -1538,15 +1616,25 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   // Advance to the next bytecode.
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, x1, x2,
+                                kInterpreterBytecodeOffsetRegister, x1, x2, x3,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(x2, kInterpreterBytecodeOffsetRegister);
   __ Str(x2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ Mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ B(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -1608,7 +1696,7 @@ void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
 
   // Restore fp, lr.
   __ Mov(sp, fp);
-  __ Pop(fp, lr);
+  __ Pop<TurboAssembler::kAuthLR>(fp, lr);
 
   __ LoadEntryFromBuiltinIndex(builtin);
   __ Jump(builtin);
@@ -1989,7 +2077,7 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
 namespace {
 
 void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
-  __ Push(lr, fp);
+  __ Push<TurboAssembler::kSignLR>(lr, fp);
   __ Mov(x11, StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR));
   __ Push(x11, x1);  // x1: function
   __ SmiTag(x11, x0);  // x0: number of arguments.
@@ -2005,7 +2093,7 @@ void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
   // then drop the parameters and the receiver.
   __ Ldr(x10, MemOperand(fp, ArgumentsAdaptorFrameConstants::kLengthOffset));
   __ Mov(sp, fp);
-  __ Pop(fp, lr);
+  __ Pop<TurboAssembler::kAuthLR>(fp, lr);
 
   // Drop actual parameters and receiver.
   __ SmiUntag(x10);
@@ -2375,7 +2463,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
       Label done;
-      LoadRealStackLimit(masm, x10);
+      LoadStackLimit(masm, x10, StackLimitKind::kRealStackLimit);
       // Make x10 the space we have left. The stack might already be overflowed
       // here which will cause x10 to become negative.
       __ Sub(x10, sp, x10);
@@ -2714,7 +2802,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   Label create_adaptor_frame, dont_adapt_arguments, stack_overflow,
       adapt_arguments_in_place;
 
-  __ Cmp(argc_expected, SharedFunctionInfo::kDontAdaptArgumentsSentinel);
+  __ Cmp(argc_expected, kDontAdaptArgumentsSentinel);
   __ B(eq, &dont_adapt_arguments);
 
   // When the difference between argc_actual and argc_expected is odd, we
@@ -2950,6 +3038,28 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(x8);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    __ PushXRegList(WasmDebugBreakFrameConstants::kPushedGpRegs);
+    __ PushDRegList(WasmDebugBreakFrameConstants::kPushedFpRegs);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ PopDRegList(WasmDebugBreakFrameConstants::kPushedFpRegs);
+    __ PopXRegList(WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
@@ -3577,9 +3687,9 @@ void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
   // DirectCEntry places the return address on the stack (updated by the GC),
   // making the call GC safe. The irregexp backend relies on this.
 
-  __ Poke(lr, 0);  // Store the return address.
+  __ Poke<TurboAssembler::kSignLR>(lr, 0);  // Store the return address.
   __ Blr(x10);     // Call the C++ function.
-  __ Peek(lr, 0);  // Return to calling code.
+  __ Peek<TurboAssembler::kAuthLR>(lr, 0);  // Return to calling code.
   __ AssertFPCRState();
   __ Ret();
 }
diff --git a/deps/v8/src/builtins/array-lastindexof.tq b/deps/v8/src/builtins/array-lastindexof.tq
index 0ba3ea4030..52bcc75d19 100644
--- a/deps/v8/src/builtins/array-lastindexof.tq
+++ b/deps/v8/src/builtins/array-lastindexof.tq
@@ -61,9 +61,8 @@ namespace array {
   GetFromIndex(context: Context, length: Number, arguments: Arguments): Number {
     // 4. If fromIndex is present, let n be ? ToInteger(fromIndex);
     //    else let n be len - 1.
-    const n: Number = arguments.length < 2 ?
-        length - 1 :
-        ToInteger_Inline(arguments[1], kTruncateMinusZero);
+    const n: Number =
+        arguments.length < 2 ? length - 1 : ToInteger_Inline(arguments[1]);
 
     // 5. If n >= 0, then.
     let k: Number = SmiConstant(0);
diff --git a/deps/v8/src/builtins/base.tq b/deps/v8/src/builtins/base.tq
index 3aa75c7413..7d87a55e88 100644
--- a/deps/v8/src/builtins/base.tq
+++ b/deps/v8/src/builtins/base.tq
@@ -29,6 +29,8 @@ type Tagged generates 'TNode<MaybeObject>' constexpr 'MaybeObject';
 type StrongTagged extends Tagged
     generates 'TNode<Object>' constexpr 'ObjectPtr';
 type Smi extends StrongTagged generates 'TNode<Smi>' constexpr 'Smi';
+type TaggedIndex extends StrongTagged
+    generates 'TNode<TaggedIndex>' constexpr 'TaggedIndex';
 // A possibly cleared weak pointer with a bit pattern that distinguishes it from
 // strong HeapObject pointers and Smi values.
 type WeakHeapObject extends Tagged;
@@ -85,7 +87,7 @@ type uint32 generates 'TNode<Uint32T>' constexpr 'uint32_t';
 type int31 extends int32
     generates 'TNode<Int32T>' constexpr 'int31_t';
 type uint31 extends uint32
-    generates 'TNode<Uint32T>' constexpr 'uint31_t';
+    generates 'TNode<Uint32T>' constexpr 'uint32_t';
 type int16 extends int31
     generates 'TNode<Int16T>' constexpr 'int16_t';
 type uint16 extends uint31
@@ -104,6 +106,9 @@ type bool generates 'TNode<BoolT>' constexpr 'bool';
 type bint generates 'TNode<BInt>' constexpr 'BInt';
 type string constexpr 'const char*';
 
+// A Smi value containing a bitfield struct as its integer data.
+type SmiTagged<T : type extends uint31> extends Smi;
+
 // WARNING: The memory representation (i.e., in class fields and arrays) of
 // float64_or_hole is just a float64 that may be the hole-representing
 // signalling NaN bit-pattern. So it's memory size is that of float64 and
@@ -156,7 +161,7 @@ type LayoutDescriptor extends ByteArray
     generates 'TNode<LayoutDescriptor>';
 extern class TransitionArray extends WeakFixedArray;
 
-type InstanceType extends uint16 constexpr 'v8::internal::InstanceType';
+type InstanceType extends uint16 constexpr 'InstanceType';
 
 type NoSharedNameSentinel extends Smi;
 
@@ -177,9 +182,6 @@ type Callable = JSFunction|JSBoundFunction|CallableJSProxy|CallableApiObject;
 type WriteBarrierMode
     generates 'TNode<Int32T>' constexpr 'WriteBarrierMode';
 
-type ToIntegerTruncationMode
-constexpr 'CodeStubAssembler::ToIntegerTruncationMode';
-
 extern enum UnicodeEncoding { UTF16, UTF32 }
 
 // Promise constants
@@ -345,10 +347,6 @@ const kSloppyArgumentsContextIndex: constexpr int31
 const kSloppyArgumentsParameterMapStart: constexpr int31
     generates 'SloppyArgumentsElements::kParameterMapStart';
 
-const kTruncateMinusZero: constexpr ToIntegerTruncationMode
-    generates 'CodeStubAssembler::ToIntegerTruncationMode::kTruncateMinusZero'
-    ;
-
 extern enum PrimitiveType { kString, kBoolean, kSymbol, kNumber }
 
 const kNameDictionaryInitialCapacity:
@@ -433,10 +431,53 @@ extern macro Comment(constexpr string);
 extern macro StaticAssert(bool);
 extern macro Print(Object);
 extern macro DebugBreak();
-extern transitioning macro ToInteger_Inline(implicit context: Context)(JSAny):
-    Number;
-extern transitioning macro ToInteger_Inline(implicit context: Context)(
-    JSAny, constexpr ToIntegerTruncationMode): Number;
+
+// ES6 7.1.4 ToInteger ( argument )
+transitioning macro ToIntegerImpl(implicit context: Context)(input: Object):
+    Number {
+  let input = input;
+
+  while (true) {
+    typeswitch (input) {
+      case (s: Smi): {
+        return s;
+      }
+      case (hn: HeapNumber): {
+        let value = Convert<float64>(hn);
+        if (Float64IsNaN(value)) return SmiConstant(0);
+        value = math::Float64Trunc(value);
+        // ToInteger normalizes -0 to +0.
+        if (value == 0.0) return SmiConstant(0);
+        const result = ChangeFloat64ToTagged(value);
+        assert(IsNumberNormalized(result));
+        return result;
+      }
+      case (ho: HeapObject): {
+        input = math::NonNumberToNumber(ho);
+      }
+    }
+  }
+  unreachable;
+}
+
+transitioning builtin ToInteger(implicit context: Context)(input: Object):
+    Number {
+  return ToIntegerImpl(input);
+}
+
+@export
+transitioning macro ToInteger_Inline(implicit context: Context)(input: Object):
+    Number {
+  typeswitch (input) {
+    case (s: Smi): {
+      return s;
+    }
+    case (ho: HeapObject): {
+      return ToInteger(ho);
+    }
+  }
+}
+
 extern transitioning macro ToLength_Inline(implicit context: Context)(JSAny):
     Number;
 extern transitioning macro ToNumber_Inline(implicit context: Context)(JSAny):
@@ -459,7 +500,8 @@ extern transitioning builtin HasProperty(implicit context: Context)(
     JSAny, JSAny): Boolean;
 extern transitioning macro HasProperty_Inline(implicit context: Context)(
     JSReceiver, JSAny): Boolean;
-extern builtin LoadIC(Context, JSAny, JSAny, Smi, FeedbackVector): JSAny;
+extern builtin LoadIC(
+    Context, JSAny, JSAny, TaggedIndex, FeedbackVector): JSAny;
 extern macro CollectCallFeedback(
     JSAny, Context, Undefined | FeedbackVector, uintptr);
 
@@ -514,7 +556,6 @@ extern macro CodeStubAssembler::AllocateNameDictionary(constexpr int32):
 extern builtin ToObject(Context, JSAny): JSReceiver;
 extern macro ToObject_Inline(Context, JSAny): JSReceiver;
 extern macro IsNullOrUndefined(Object): bool;
-extern macro IsTheHole(Object): bool;
 extern macro IsString(HeapObject): bool;
 transitioning builtin ToString(context: Context, o: JSAny): String {
   return ToStringImpl(context, o);
@@ -724,6 +765,10 @@ ConstexprInt31NotEqual(constexpr int31, constexpr int31): constexpr bool;
 extern operator '>=' macro
 ConstexprInt31GreaterThanEqual(
     constexpr int31, constexpr int31): constexpr bool;
+extern operator '==' macro ConstexprInt32Equal(
+    constexpr int32, constexpr int32): constexpr bool;
+extern operator '!=' macro ConstexprInt32NotEqual(
+    constexpr int32, constexpr int32): constexpr bool;
 
 extern operator '==' macro Word32Equal(int32, int32): bool;
 extern operator '==' macro Word32Equal(uint32, uint32): bool;
@@ -833,7 +878,14 @@ extern macro SmiTag(intptr): Smi;
 extern macro SmiFromInt32(int32): Smi;
 extern macro SmiFromUint32(uint32): Smi;
 extern macro SmiUntag(Smi): intptr;
+macro SmiUntag<T: type>(value: SmiTagged<T>): T {
+  return %RawDownCast<T>(Unsigned(SmiToInt32(Convert<Smi>(value))));
+}
 extern macro SmiToInt32(Smi): int32;
+extern macro TaggedIndexToIntPtr(TaggedIndex): intptr;
+extern macro IntPtrToTaggedIndex(intptr): TaggedIndex;
+extern macro TaggedIndexToSmi(TaggedIndex): Smi;
+extern macro SmiToTaggedIndex(Smi): TaggedIndex;
 extern macro RoundIntPtrToFloat64(intptr): float64;
 extern macro ChangeFloat32ToFloat64(float32): float64;
 extern macro ChangeNumberToFloat64(Number): float64;
@@ -888,6 +940,10 @@ macro UnsafeCast<A : type extends Object>(implicit context: Context)(o: Object):
   return %RawDownCast<A>(o);
 }
 
+macro UnsafeConstCast<T: type>(r: const &T):&T {
+  return %RawDownCast<&T>(r);
+}
+
 extern macro FixedArrayMapConstant(): Map;
 extern macro FixedDoubleArrayMapConstant(): Map;
 extern macro FixedCOWArrayMapConstant(): Map;
@@ -1206,7 +1262,7 @@ macro ChangeSafeIntegerNumberToUintPtr(value: Number):
 transitioning macro ToUintPtr(implicit context: Context)(value: JSAny):
     uintptr labels IfLessThanZero, IfUIntPtrOverflow, IfSafeIntegerOverflow {
   if (value == Undefined) return 0;
-  const indexNumber = ToInteger_Inline(value, kTruncateMinusZero);
+  const indexNumber = ToInteger_Inline(value);
   return TryNumberToUintPtr(indexNumber, kModeValueIsAnyNumber)
       otherwise IfLessThanZero, IfUIntPtrOverflow, IfSafeIntegerOverflow;
 }
@@ -1220,7 +1276,7 @@ transitioning macro ToUintPtr(implicit context: Context)(value: JSAny):
 transitioning macro ToIndex(implicit context: Context)(value: JSAny):
     uintptr labels IfRangeError {
   if (value == Undefined) return 0;
-  const indexNumber = ToInteger_Inline(value, kTruncateMinusZero);
+  const indexNumber = ToInteger_Inline(value);
   // Less than 0 case, uintptr range overflow and safe integer range overflow
   // imply IfRangeError.
   return TryNumberToUintPtr(indexNumber, kModeValueIsAnyNumber)
@@ -1293,7 +1349,7 @@ extern macro IsOneByteStringInstanceType(InstanceType): bool;
 @export
 transitioning macro ConvertToRelativeIndex(implicit context: Context)(
     index: JSAny, length: uintptr): uintptr {
-  const indexNumber: Number = ToInteger_Inline(index, kTruncateMinusZero);
+  const indexNumber: Number = ToInteger_Inline(index);
   return ConvertToRelativeIndex(indexNumber, length);
 }
 
@@ -1340,7 +1396,7 @@ macro ConvertToRelativeIndex(indexNumber: Number, length: uintptr): uintptr {
 @export
 transitioning macro ClampToIndexRange(implicit context: Context)(
     index: JSAny, limit: uintptr): uintptr {
-  const indexNumber: Number = ToInteger_Inline(index, kTruncateMinusZero);
+  const indexNumber: Number = ToInteger_Inline(index);
   return ClampToIndexRange(indexNumber, limit);
 }
 
@@ -1560,6 +1616,29 @@ builtin CheckNumberInRange(implicit context: Context)(
   }
 }
 
+// Assert that the objects satisfy SameValue or are both the hole.
+builtin CheckSameObject(implicit context: Context)(
+    lhs: Object, rhs: Object): Undefined {
+  typeswitch (lhs) {
+    case (TheHole): {
+      if (rhs == TheHole) return Undefined;
+    }
+    case (a: JSAny): {
+      typeswitch (rhs) {
+        case (b: JSAny): {
+          if (SameValue(a, b)) return Undefined;
+        }
+        case (Object): {
+        }
+      }
+    }
+    case (Object): {
+    }
+  }
+  Print('Distinct or unexpected values in CheckSameObject');
+  unreachable;
+}
+
 macro ReplaceTheHoleWithUndefined(o: JSAny|TheHole): JSAny {
   typeswitch (o) {
     case (TheHole): {
diff --git a/deps/v8/src/builtins/builtins-api.cc b/deps/v8/src/builtins/builtins-api.cc
index 0c30e52154..6eb6f87c74 100644
--- a/deps/v8/src/builtins/builtins-api.cc
+++ b/deps/v8/src/builtins/builtins-api.cc
@@ -105,9 +105,9 @@ V8_WARN_UNUSED_RESULT MaybeHandle<Object> HandleApiCallHelper(
     CallHandlerInfo call_data = CallHandlerInfo::cast(raw_call_data);
     Object data_obj = call_data.data();
 
-    FunctionCallbackArguments custom(isolate, data_obj, *function, raw_holder,
-                                     *new_target, args.address_of_arg_at(1),
-                                     args.length() - 1);
+    FunctionCallbackArguments custom(
+        isolate, data_obj, *function, raw_holder, *new_target,
+        args.address_of_first_argument(), args.length() - 1);
     Handle<Object> result = custom.Call(call_data);
 
     RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
@@ -206,6 +206,18 @@ MaybeHandle<Object> Builtins::InvokeApiFunction(Isolate* isolate,
   } else {
     argv = new Address[frame_argc];
   }
+#ifdef V8_REVERSE_JSARGS
+  argv[BuiltinArguments::kNewTargetOffset] = new_target->ptr();
+  argv[BuiltinArguments::kTargetOffset] = function->ptr();
+  argv[BuiltinArguments::kArgcOffset] = Smi::FromInt(frame_argc).ptr();
+  argv[BuiltinArguments::kPaddingOffset] =
+      ReadOnlyRoots(isolate).the_hole_value().ptr();
+  int cursor = BuiltinArguments::kNumExtraArgs;
+  argv[cursor++] = receiver->ptr();
+  for (int i = 0; i < argc; ++i) {
+    argv[cursor++] = args[i]->ptr();
+  }
+#else
   int cursor = frame_argc - 1;
   argv[cursor--] = receiver->ptr();
   for (int i = 0; i < argc; ++i) {
@@ -217,6 +229,7 @@ MaybeHandle<Object> Builtins::InvokeApiFunction(Isolate* isolate,
   argv[BuiltinArguments::kArgcOffset] = Smi::FromInt(frame_argc).ptr();
   argv[BuiltinArguments::kTargetOffset] = function->ptr();
   argv[BuiltinArguments::kNewTargetOffset] = new_target->ptr();
+#endif
   MaybeHandle<Object> result;
   {
     RelocatableArguments arguments(isolate, frame_argc, &argv[frame_argc - 1]);
@@ -269,9 +282,9 @@ V8_WARN_UNUSED_RESULT static Object HandleApiCallAsFunctionOrConstructor(
   {
     HandleScope scope(isolate);
     LOG(isolate, ApiObjectAccess("call non-function", obj));
-    FunctionCallbackArguments custom(isolate, call_data.data(), constructor,
-                                     obj, new_target, args.address_of_arg_at(1),
-                                     args.length() - 1);
+    FunctionCallbackArguments custom(
+        isolate, call_data.data(), constructor, obj, new_target,
+        args.address_of_first_argument(), args.length() - 1);
     Handle<Object> result_handle = custom.Call(call_data);
     if (result_handle.is_null()) {
       result = ReadOnlyRoots(isolate).undefined_value();
diff --git a/deps/v8/src/builtins/builtins-array-gen.cc b/deps/v8/src/builtins/builtins-array-gen.cc
index 1892406305..734b9b634a 100644
--- a/deps/v8/src/builtins/builtins-array-gen.cc
+++ b/deps/v8/src/builtins/builtins-array-gen.cc
@@ -50,8 +50,7 @@ TNode<Object> ArrayBuiltinsAssembler::TypedArrayMapProcessor(
   // 8. c. Let mapped_value be ? Call(callbackfn, T, « kValue, k, O »).
   TNode<Number> k_number = ChangeUintPtrToTagged(k);
   TNode<Object> mapped_value =
-      CallJS(CodeFactory::Call(isolate()), context(), callbackfn(), this_arg(),
-             k_value, k_number, o());
+      Call(context(), callbackfn(), this_arg(), k_value, k_number, o());
   Label fast(this), slow(this), done(this), detached(this, Label::kDeferred);
 
   // 8. d. Perform ? Set(A, Pk, mapped_value, true).
@@ -544,8 +543,8 @@ class ArrayPopulatorAssembler : public CodeStubAssembler {
 };
 
 TF_BUILTIN(TypedArrayPrototypeMap, ArrayBuiltinsAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<Object> receiver = args.GetReceiver();
@@ -1071,8 +1070,8 @@ void ArrayIncludesIndexofAssembler::GenerateHoleyDoubles(
 }
 
 TF_BUILTIN(ArrayIncludes, ArrayIncludesIndexofAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Generate(kIncludes, argc, context);
@@ -1112,8 +1111,8 @@ TF_BUILTIN(ArrayIncludesHoleyDoubles, ArrayIncludesIndexofAssembler) {
 }
 
 TF_BUILTIN(ArrayIndexOf, ArrayIncludesIndexofAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Generate(kIndexOf, argc, context);
@@ -1420,9 +1419,9 @@ class ArrayFlattenAssembler : public CodeStubAssembler {
 
           // 1. Set element to ? Call(mapperFunction, thisArg , « element,
           //                          sourceIndex, source »).
-          element_maybe_smi = CallJS(CodeFactory::Call(isolate()), context,
-                                     mapper_function.value(), this_arg.value(),
-                                     element_maybe_smi, source_index, source);
+          element_maybe_smi =
+              Call(context, mapper_function.value(), this_arg.value(),
+                   element_maybe_smi, source_index, source);
         }
 
         // iii. Let shouldFlatten be false.
@@ -1541,8 +1540,8 @@ TF_BUILTIN(FlatMapIntoArray, ArrayFlattenAssembler) {
 
 // https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flat
 TF_BUILTIN(ArrayPrototypeFlat, CodeStubAssembler) {
-  const TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  const TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
   const TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   const TNode<Object> receiver = args.GetReceiver();
@@ -1583,8 +1582,8 @@ TF_BUILTIN(ArrayPrototypeFlat, CodeStubAssembler) {
 
 // https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flatMap
 TF_BUILTIN(ArrayPrototypeFlatMap, CodeStubAssembler) {
-  const TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  const TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
   const TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   const TNode<Object> receiver = args.GetReceiver();
@@ -1871,8 +1870,8 @@ void ArrayBuiltinsAssembler::GenerateConstructor(
 
   BIND(&call_runtime);
   {
-    TailCallRuntime(Runtime::kNewArray, context, array_function, array_size,
-                    array_function, allocation_site);
+    TailCallRuntimeNewArray(context, array_function, array_size, array_function,
+                            allocation_site);
   }
 }
 
diff --git a/deps/v8/src/builtins/builtins-async-generator-gen.cc b/deps/v8/src/builtins/builtins-async-generator-gen.cc
index acc7721465..592400415b 100644
--- a/deps/v8/src/builtins/builtins-async-generator-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-generator-gen.cc
@@ -311,8 +311,8 @@ AsyncGeneratorBuiltinsAssembler::TakeFirstAsyncGeneratorRequestFromQueue(
 TF_BUILTIN(AsyncGeneratorPrototypeNext, AsyncGeneratorBuiltinsAssembler) {
   const int kValueArg = 0;
 
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Object> generator = args.GetReceiver();
@@ -329,8 +329,8 @@ TF_BUILTIN(AsyncGeneratorPrototypeNext, AsyncGeneratorBuiltinsAssembler) {
 TF_BUILTIN(AsyncGeneratorPrototypeReturn, AsyncGeneratorBuiltinsAssembler) {
   const int kValueArg = 0;
 
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Object> generator = args.GetReceiver();
@@ -347,8 +347,8 @@ TF_BUILTIN(AsyncGeneratorPrototypeReturn, AsyncGeneratorBuiltinsAssembler) {
 TF_BUILTIN(AsyncGeneratorPrototypeThrow, AsyncGeneratorBuiltinsAssembler) {
   const int kValueArg = 0;
 
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Object> generator = args.GetReceiver();
diff --git a/deps/v8/src/builtins/builtins-async-iterator-gen.cc b/deps/v8/src/builtins/builtins-async-iterator-gen.cc
index 1515605649..b138515af6 100644
--- a/deps/v8/src/builtins/builtins-async-iterator-gen.cc
+++ b/deps/v8/src/builtins/builtins-async-iterator-gen.cc
@@ -13,8 +13,6 @@
 namespace v8 {
 namespace internal {
 
-using compiler::Node;
-
 namespace {
 class AsyncFromSyncBuiltinsAssembler : public AsyncBuiltinsAssembler {
  public:
@@ -130,9 +128,11 @@ void AsyncFromSyncBuiltinsAssembler::Generate_AsyncFromSyncIteratorMethod(
     BIND(&if_isnotundefined);
   }
 
-  const TNode<Object> iter_result = CallJS(
-      CodeFactory::Call(isolate()), context, method, sync_iterator, sent_value);
-  GotoIfException(iter_result, &reject_promise, &var_exception);
+  TNode<Object> iter_result;
+  {
+    ScopedExceptionHandler handler(this, &reject_promise, &var_exception);
+    iter_result = Call(context, method, sync_iterator, sent_value);
+  }
 
   TNode<Object> value;
   TNode<Oddball> done;
@@ -144,10 +144,13 @@ void AsyncFromSyncBuiltinsAssembler::Generate_AsyncFromSyncIteratorMethod(
   CSA_ASSERT(this, IsConstructor(promise_fun));
 
   // Let valueWrapper be PromiseResolve(%Promise%, « value »).
-  const TNode<Object> value_wrapper = CallBuiltin(
-      Builtins::kPromiseResolve, native_context, promise_fun, value);
   // IfAbruptRejectPromise(valueWrapper, promiseCapability).
-  GotoIfException(value_wrapper, &reject_promise, &var_exception);
+  TNode<Object> value_wrapper;
+  {
+    ScopedExceptionHandler handler(this, &reject_promise, &var_exception);
+    value_wrapper = CallBuiltin(Builtins::kPromiseResolve, native_context,
+                                promise_fun, value);
+  }
 
   // Let onFulfilled be a new built-in function object as defined in
   // Async Iterator Value Unwrap Functions.
@@ -200,17 +203,17 @@ AsyncFromSyncBuiltinsAssembler::LoadIteratorResult(
 
   BIND(&if_slowpath);
   {
+    ScopedExceptionHandler handler(this, if_exception, var_exception);
+
     // Let nextDone be IteratorComplete(nextResult).
     // IfAbruptRejectPromise(nextDone, promiseCapability).
     const TNode<Object> done =
         GetProperty(context, iter_result, factory()->done_string());
-    GotoIfException(done, if_exception, var_exception);
 
     // Let nextValue be IteratorValue(nextResult).
     // IfAbruptRejectPromise(nextValue, promiseCapability).
     const TNode<Object> value =
         GetProperty(context, iter_result, factory()->value_string());
-    GotoIfException(value, if_exception, var_exception);
 
     var_value = value;
     var_done = done;
diff --git a/deps/v8/src/builtins/builtins-call-gen.cc b/deps/v8/src/builtins/builtins-call-gen.cc
index cfe82594df..1b53e9ca8e 100644
--- a/deps/v8/src/builtins/builtins-call-gen.cc
+++ b/deps/v8/src/builtins/builtins-call-gen.cc
@@ -65,14 +65,14 @@ void Builtins::Generate_CallFunctionForwardVarargs(MacroAssembler* masm) {
 }
 
 void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
-    TNode<Object> target, SloppyTNode<Object> new_target,
+    TNode<Object> target, base::Optional<TNode<Object>> new_target,
     TNode<Object> arguments_list, TNode<Context> context) {
   Label if_done(this), if_arguments(this), if_array(this),
       if_holey_array(this, Label::kDeferred),
       if_runtime(this, Label::kDeferred);
 
   // Perform appropriate checks on {target} (and {new_target} first).
-  if (new_target == nullptr) {
+  if (!new_target) {
     // Check that {target} is Callable.
     Label if_target_callable(this),
         if_target_not_callable(this, Label::kDeferred);
@@ -102,12 +102,12 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
     // Check that {new_target} is a Constructor.
     Label if_new_target_constructor(this),
         if_new_target_not_constructor(this, Label::kDeferred);
-    GotoIf(TaggedIsSmi(new_target), &if_new_target_not_constructor);
-    Branch(IsConstructor(CAST(new_target)), &if_new_target_constructor,
+    GotoIf(TaggedIsSmi(*new_target), &if_new_target_not_constructor);
+    Branch(IsConstructor(CAST(*new_target)), &if_new_target_constructor,
            &if_new_target_not_constructor);
     BIND(&if_new_target_not_constructor);
     {
-      CallRuntime(Runtime::kThrowNotConstructor, context, new_target);
+      CallRuntime(Runtime::kThrowNotConstructor, context, *new_target);
       Unreachable();
     }
     BIND(&if_new_target_constructor);
@@ -215,12 +215,12 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
 
     BIND(&if_not_double);
     {
-      if (new_target == nullptr) {
+      if (!new_target) {
         Callable callable = CodeFactory::CallVarargs(isolate());
         TailCallStub(callable, context, target, args_count, length, elements);
       } else {
         Callable callable = CodeFactory::ConstructVarargs(isolate());
-        TailCallStub(callable, context, target, new_target, args_count, length,
+        TailCallStub(callable, context, target, *new_target, args_count, length,
                      elements);
       }
     }
@@ -240,7 +240,7 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithArrayLike(
 // boxed as HeapNumbers, then tail calls CallVarargs/ConstructVarargs depending
 // on whether {new_target} was passed.
 void CallOrConstructBuiltinsAssembler::CallOrConstructDoubleVarargs(
-    TNode<Object> target, SloppyTNode<Object> new_target,
+    TNode<Object> target, base::Optional<TNode<Object>> new_target,
     TNode<FixedDoubleArray> elements, TNode<Int32T> length,
     TNode<Int32T> args_count, TNode<Context> context, TNode<Int32T> kind) {
   const ElementsKind new_kind = PACKED_ELEMENTS;
@@ -258,19 +258,19 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructDoubleVarargs(
   CopyFixedArrayElements(PACKED_DOUBLE_ELEMENTS, elements, new_kind,
                          new_elements, intptr_length, intptr_length,
                          barrier_mode);
-  if (new_target == nullptr) {
+  if (!new_target) {
     Callable callable = CodeFactory::CallVarargs(isolate());
     TailCallStub(callable, context, target, args_count, length, new_elements);
   } else {
     Callable callable = CodeFactory::ConstructVarargs(isolate());
-    TailCallStub(callable, context, target, new_target, args_count, length,
+    TailCallStub(callable, context, target, *new_target, args_count, length,
                  new_elements);
   }
 }
 
 void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
-    TNode<Object> target, TNode<Object> new_target, TNode<Object> spread,
-    TNode<Int32T> args_count, TNode<Context> context) {
+    TNode<Object> target, base::Optional<TNode<Object>> new_target,
+    TNode<Object> spread, TNode<Int32T> args_count, TNode<Context> context) {
   Label if_smiorobject(this), if_double(this),
       if_generic(this, Label::kDeferred);
 
@@ -316,7 +316,11 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
 
   BIND(&if_generic);
   {
-    Label if_iterator_fn_not_callable(this, Label::kDeferred);
+    Label if_iterator_fn_not_callable(this, Label::kDeferred),
+        if_iterator_is_null_or_undefined(this, Label::kDeferred);
+
+    GotoIf(IsNullOrUndefined(spread), &if_iterator_is_null_or_undefined);
+
     TNode<Object> iterator_fn =
         GetProperty(context, spread, IteratorSymbolConstant());
     GotoIfNot(TaggedIsCallable(iterator_fn), &if_iterator_fn_not_callable);
@@ -333,6 +337,10 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
 
     BIND(&if_iterator_fn_not_callable);
     ThrowTypeError(context, MessageTemplate::kIteratorSymbolNonCallable);
+
+    BIND(&if_iterator_is_null_or_undefined);
+    CallRuntime(Runtime::kThrowSpreadArgIsNullOrUndefined, context, spread);
+    Unreachable();
   }
 
   BIND(&if_smiorobject);
@@ -342,12 +350,12 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
     CSA_ASSERT(this, Int32LessThanOrEqual(
                          length, Int32Constant(FixedArray::kMaxLength)));
 
-    if (new_target == nullptr) {
+    if (!new_target) {
       Callable callable = CodeFactory::CallVarargs(isolate());
       TailCallStub(callable, context, target, args_count, length, elements);
     } else {
       Callable callable = CodeFactory::ConstructVarargs(isolate());
-      TailCallStub(callable, context, target, new_target, args_count, length,
+      TailCallStub(callable, context, target, *new_target, args_count, length,
                    elements);
     }
   }
@@ -363,7 +371,7 @@ void CallOrConstructBuiltinsAssembler::CallOrConstructWithSpread(
 
 TF_BUILTIN(CallWithArrayLike, CallOrConstructBuiltinsAssembler) {
   TNode<Object> target = CAST(Parameter(Descriptor::kTarget));
-  SloppyTNode<Object> new_target = nullptr;
+  base::Optional<TNode<Object>> new_target = base::nullopt;
   TNode<Object> arguments_list = CAST(Parameter(Descriptor::kArgumentsList));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   CallOrConstructWithArrayLike(target, new_target, arguments_list, context);
@@ -371,7 +379,7 @@ TF_BUILTIN(CallWithArrayLike, CallOrConstructBuiltinsAssembler) {
 
 TF_BUILTIN(CallWithSpread, CallOrConstructBuiltinsAssembler) {
   TNode<Object> target = CAST(Parameter(Descriptor::kTarget));
-  SloppyTNode<Object> new_target = nullptr;
+  base::Optional<TNode<Object>> new_target = base::nullopt;
   TNode<Object> spread = CAST(Parameter(Descriptor::kSpread));
   TNode<Int32T> args_count =
       UncheckedCast<Int32T>(Parameter(Descriptor::kArgumentsCount));
diff --git a/deps/v8/src/builtins/builtins-call-gen.h b/deps/v8/src/builtins/builtins-call-gen.h
index a15f31dd09..d54e4405e0 100644
--- a/deps/v8/src/builtins/builtins-call-gen.h
+++ b/deps/v8/src/builtins/builtins-call-gen.h
@@ -16,16 +16,17 @@ class CallOrConstructBuiltinsAssembler : public CodeStubAssembler {
       : CodeStubAssembler(state) {}
 
   void CallOrConstructWithArrayLike(TNode<Object> target,
-                                    SloppyTNode<Object> new_target,
+                                    base::Optional<TNode<Object>> new_target,
                                     TNode<Object> arguments_list,
                                     TNode<Context> context);
   void CallOrConstructDoubleVarargs(TNode<Object> target,
-                                    SloppyTNode<Object> new_target,
+                                    base::Optional<TNode<Object>> new_target,
                                     TNode<FixedDoubleArray> elements,
                                     TNode<Int32T> length,
                                     TNode<Int32T> args_count,
                                     TNode<Context> context, TNode<Int32T> kind);
-  void CallOrConstructWithSpread(TNode<Object> target, TNode<Object> new_target,
+  void CallOrConstructWithSpread(TNode<Object> target,
+                                 base::Optional<TNode<Object>> new_target,
                                  TNode<Object> spread, TNode<Int32T> args_count,
                                  TNode<Context> context);
 
diff --git a/deps/v8/src/builtins/builtins-collections-gen.cc b/deps/v8/src/builtins/builtins-collections-gen.cc
index df758e0e9f..df0ebce993 100644
--- a/deps/v8/src/builtins/builtins-collections-gen.cc
+++ b/deps/v8/src/builtins/builtins-collections-gen.cc
@@ -14,6 +14,7 @@
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-collection.h"
 #include "src/objects/ordered-hash-table.h"
+#include "src/roots/roots.h"
 
 namespace v8 {
 namespace internal {
@@ -150,8 +151,7 @@ void BaseCollectionsAssembler::AddConstructorEntry(
     TNode<Object> add_function, TNode<Object> key_value,
     Label* if_may_have_side_effects, Label* if_exception,
     TVariable<Object>* var_exception) {
-  compiler::CodeAssemblerScopedExceptionHandler handler(this, if_exception,
-                                                        var_exception);
+  compiler::ScopedExceptionHandler handler(this, if_exception, var_exception);
   CSA_ASSERT(this, Word32BinaryNot(IsTheHole(key_value)));
   if (variant == kMap || variant == kWeakMap) {
     TorqueStructKeyValuePair pair =
@@ -161,12 +161,10 @@ void BaseCollectionsAssembler::AddConstructorEntry(
             : LoadKeyValuePair(context, key_value);
     TNode<Object> key_n = pair.key;
     TNode<Object> value_n = pair.value;
-    CallJS(CodeFactory::Call(isolate()), context, add_function, collection,
-           key_n, value_n);
+    Call(context, add_function, collection, key_n, value_n);
   } else {
     DCHECK(variant == kSet || variant == kWeakSet);
-    CallJS(CodeFactory::Call(isolate()), context, add_function, collection,
-           key_value);
+    Call(context, add_function, collection, key_value);
   }
 }
 
@@ -854,8 +852,8 @@ TNode<HeapObject> CollectionsBuiltinsAssembler::AllocateTable(
 
 TF_BUILTIN(MapConstructor, CollectionsBuiltinsAssembler) {
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   GenerateConstructor(kMap, isolate()->factory()->Map_string(), new_target,
@@ -864,8 +862,8 @@ TF_BUILTIN(MapConstructor, CollectionsBuiltinsAssembler) {
 
 TF_BUILTIN(SetConstructor, CollectionsBuiltinsAssembler) {
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   GenerateConstructor(kSet, isolate()->factory()->Set_string(), new_target,
@@ -2035,8 +2033,7 @@ TF_BUILTIN(MapPrototypeForEach, CollectionsBuiltinsAssembler) {
 
     // Invoke the {callback} passing the {entry_key}, {entry_value} and the
     // {receiver}.
-    CallJS(CodeFactory::Call(isolate()), context, callback, this_arg,
-           entry_value, entry_key, receiver);
+    Call(context, callback, this_arg, entry_value, entry_key, receiver);
 
     // Continue with the next entry.
     var_index = index;
@@ -2266,8 +2263,7 @@ TF_BUILTIN(SetPrototypeForEach, CollectionsBuiltinsAssembler) {
         NextSkipHoles<OrderedHashSet>(table, index, &done_loop);
 
     // Invoke the {callback} passing the {entry_key} (twice) and the {receiver}.
-    CallJS(CodeFactory::Call(isolate()), context, callback, this_arg, entry_key,
-           entry_key, receiver);
+    Call(context, callback, this_arg, entry_key, entry_key, receiver);
 
     // Continue with the next entry.
     var_index = index;
@@ -2513,8 +2509,9 @@ TNode<HeapObject> WeakCollectionsBuiltinsAssembler::AllocateTable(
   TNode<FixedArray> table = CAST(
       AllocateFixedArray(HOLEY_ELEMENTS, length, kAllowLargeObjectAllocation));
 
-  RootIndex map_root_index = EphemeronHashTableShape::GetMapRootIndex();
-  StoreMapNoWriteBarrier(table, map_root_index);
+  TNode<Map> map =
+      HeapConstant(EphemeronHashTableShape::GetMap(ReadOnlyRoots(isolate())));
+  StoreMapNoWriteBarrier(table, map);
   StoreFixedArrayElement(table, EphemeronHashTable::kNumberOfElementsIndex,
                          SmiConstant(0), SKIP_WRITE_BARRIER);
   StoreFixedArrayElement(table,
@@ -2703,8 +2700,8 @@ TNode<IntPtrT> WeakCollectionsBuiltinsAssembler::ValueIndexFromKeyIndex(
 
 TF_BUILTIN(WeakMapConstructor, WeakCollectionsBuiltinsAssembler) {
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   GenerateConstructor(kWeakMap, isolate()->factory()->WeakMap_string(),
@@ -2713,8 +2710,8 @@ TF_BUILTIN(WeakMapConstructor, WeakCollectionsBuiltinsAssembler) {
 
 TF_BUILTIN(WeakSetConstructor, WeakCollectionsBuiltinsAssembler) {
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   GenerateConstructor(kWeakSet, isolate()->factory()->WeakSet_string(),
diff --git a/deps/v8/src/builtins/builtins-constructor-gen.cc b/deps/v8/src/builtins/builtins-constructor-gen.cc
index 01f3db63f3..c706ce9306 100644
--- a/deps/v8/src/builtins/builtins-constructor-gen.cc
+++ b/deps/v8/src/builtins/builtins-constructor-gen.cc
@@ -38,7 +38,7 @@ void Builtins::Generate_ConstructFunctionForwardVarargs(MacroAssembler* masm) {
 
 TF_BUILTIN(ConstructWithArrayLike, CallOrConstructBuiltinsAssembler) {
   TNode<Object> target = CAST(Parameter(Descriptor::kTarget));
-  SloppyTNode<Object> new_target = CAST(Parameter(Descriptor::kNewTarget));
+  TNode<Object> new_target = CAST(Parameter(Descriptor::kNewTarget));
   TNode<Object> arguments_list = CAST(Parameter(Descriptor::kArgumentsList));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   CallOrConstructWithArrayLike(target, new_target, arguments_list, context);
@@ -46,7 +46,7 @@ TF_BUILTIN(ConstructWithArrayLike, CallOrConstructBuiltinsAssembler) {
 
 TF_BUILTIN(ConstructWithSpread, CallOrConstructBuiltinsAssembler) {
   TNode<Object> target = CAST(Parameter(Descriptor::kTarget));
-  SloppyTNode<Object> new_target = CAST(Parameter(Descriptor::kNewTarget));
+  TNode<Object> new_target = CAST(Parameter(Descriptor::kNewTarget));
   TNode<Object> spread = CAST(Parameter(Descriptor::kSpread));
   TNode<Int32T> args_count =
       UncheckedCast<Int32T>(Parameter(Descriptor::kActualArgumentsCount));
@@ -160,8 +160,8 @@ TF_BUILTIN(FastNewObject, ConstructorBuiltinsAssembler) {
 }
 
 TNode<JSObject> ConstructorBuiltinsAssembler::EmitFastNewObject(
-    SloppyTNode<Context> context, SloppyTNode<JSFunction> target,
-    SloppyTNode<JSReceiver> new_target) {
+    TNode<Context> context, TNode<JSFunction> target,
+    TNode<JSReceiver> new_target) {
   TVARIABLE(JSObject, var_obj);
   Label call_runtime(this), end(this);
 
@@ -177,8 +177,8 @@ TNode<JSObject> ConstructorBuiltinsAssembler::EmitFastNewObject(
 }
 
 TNode<JSObject> ConstructorBuiltinsAssembler::EmitFastNewObject(
-    SloppyTNode<Context> context, SloppyTNode<JSFunction> target,
-    SloppyTNode<JSReceiver> new_target, Label* call_runtime) {
+    TNode<Context> context, TNode<JSFunction> target,
+    TNode<JSReceiver> new_target, Label* call_runtime) {
   // Verify that the new target is a JSFunction.
   Label end(this);
   TNode<JSFunction> new_target_func =
@@ -284,7 +284,7 @@ TF_BUILTIN(FastNewFunctionContextFunction, ConstructorBuiltinsAssembler) {
 }
 
 TNode<JSRegExp> ConstructorBuiltinsAssembler::EmitCreateRegExpLiteral(
-    TNode<HeapObject> maybe_feedback_vector, TNode<UintPtrT> slot,
+    TNode<HeapObject> maybe_feedback_vector, TNode<TaggedIndex> slot,
     TNode<Object> pattern, TNode<Smi> flags, TNode<Context> context) {
   Label call_runtime(this, Label::kDeferred), end(this);
 
@@ -311,8 +311,7 @@ TNode<JSRegExp> ConstructorBuiltinsAssembler::EmitCreateRegExpLiteral(
   BIND(&call_runtime);
   {
     result = CAST(CallRuntime(Runtime::kCreateRegExpLiteral, context,
-                              maybe_feedback_vector, SmiTag(Signed(slot)),
-                              pattern, flags));
+                              maybe_feedback_vector, slot, pattern, flags));
     Goto(&end);
   }
 
@@ -323,7 +322,7 @@ TNode<JSRegExp> ConstructorBuiltinsAssembler::EmitCreateRegExpLiteral(
 TF_BUILTIN(CreateRegExpLiteral, ConstructorBuiltinsAssembler) {
   TNode<HeapObject> maybe_feedback_vector =
       CAST(Parameter(Descriptor::kFeedbackVector));
-  TNode<UintPtrT> slot = Unsigned(SmiUntag(Parameter(Descriptor::kSlot)));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Object> pattern = CAST(Parameter(Descriptor::kPattern));
   TNode<Smi> flags = CAST(Parameter(Descriptor::kFlags));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
@@ -333,7 +332,7 @@ TF_BUILTIN(CreateRegExpLiteral, ConstructorBuiltinsAssembler) {
 }
 
 TNode<JSArray> ConstructorBuiltinsAssembler::EmitCreateShallowArrayLiteral(
-    TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+    TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
     TNode<Context> context, Label* call_runtime,
     AllocationSiteMode allocation_site_mode) {
   Label zero_capacity(this), cow_elements(this), fast_elements(this),
@@ -356,7 +355,7 @@ TNode<JSArray> ConstructorBuiltinsAssembler::EmitCreateShallowArrayLiteral(
 TF_BUILTIN(CreateShallowArrayLiteral, ConstructorBuiltinsAssembler) {
   TNode<FeedbackVector> feedback_vector =
       CAST(Parameter(Descriptor::kFeedbackVector));
-  TNode<UintPtrT> slot = Unsigned(SmiUntag(Parameter(Descriptor::kSlot)));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<ArrayBoilerplateDescription> constant_elements =
       CAST(Parameter(Descriptor::kConstantElements));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
@@ -371,13 +370,12 @@ TF_BUILTIN(CreateShallowArrayLiteral, ConstructorBuiltinsAssembler) {
     int const flags =
         AggregateLiteral::kDisableMementos | AggregateLiteral::kIsShallow;
     Return(CallRuntime(Runtime::kCreateArrayLiteral, context, feedback_vector,
-                       SmiTag(Signed(slot)), constant_elements,
-                       SmiConstant(flags)));
+                       slot, constant_elements, SmiConstant(flags)));
   }
 }
 
 TNode<JSArray> ConstructorBuiltinsAssembler::EmitCreateEmptyArrayLiteral(
-    TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+    TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
     TNode<Context> context) {
   // Array literals always have a valid AllocationSite to properly track
   // elements transitions.
@@ -395,8 +393,10 @@ TNode<JSArray> ConstructorBuiltinsAssembler::EmitCreateEmptyArrayLiteral(
   // TODO(cbruni): create the AllocationSite in CSA.
   BIND(&initialize_allocation_site);
   {
-    allocation_site =
-        CreateAllocationSiteInFeedbackVector(feedback_vector, slot);
+    allocation_site = CreateAllocationSiteInFeedbackVector(
+        feedback_vector,
+        // TODO(v8:10047): pass slot as TaggedIndex here
+        Unsigned(TaggedIndexToIntPtr(slot)));
     Goto(&create_empty_array);
   }
 
@@ -421,7 +421,7 @@ TNode<JSArray> ConstructorBuiltinsAssembler::EmitCreateEmptyArrayLiteral(
 TF_BUILTIN(CreateEmptyArrayLiteral, ConstructorBuiltinsAssembler) {
   TNode<FeedbackVector> feedback_vector =
       CAST(Parameter(Descriptor::kFeedbackVector));
-  TNode<UintPtrT> slot = Unsigned(SmiUntag(Parameter(Descriptor::kSlot)));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<JSArray> result =
       EmitCreateEmptyArrayLiteral(feedback_vector, slot, context);
@@ -429,7 +429,7 @@ TF_BUILTIN(CreateEmptyArrayLiteral, ConstructorBuiltinsAssembler) {
 }
 
 TNode<HeapObject> ConstructorBuiltinsAssembler::EmitCreateShallowObjectLiteral(
-    TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+    TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
     Label* call_runtime) {
   TNode<Object> maybe_allocation_site =
       CAST(LoadFeedbackVectorSlot(feedback_vector, slot));
@@ -609,7 +609,7 @@ TF_BUILTIN(CreateShallowObjectLiteral, ConstructorBuiltinsAssembler) {
   Label call_runtime(this);
   TNode<FeedbackVector> feedback_vector =
       CAST(Parameter(Descriptor::kFeedbackVector));
-  TNode<UintPtrT> slot = Unsigned(SmiUntag(Parameter(Descriptor::kSlot)));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> copy =
       EmitCreateShallowObjectLiteral(feedback_vector, slot, &call_runtime);
   Return(copy);
@@ -619,8 +619,8 @@ TF_BUILTIN(CreateShallowObjectLiteral, ConstructorBuiltinsAssembler) {
       CAST(Parameter(Descriptor::kObjectBoilerplateDescription));
   TNode<Smi> flags = CAST(Parameter(Descriptor::kFlags));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  TailCallRuntime(Runtime::kCreateObjectLiteral, context, feedback_vector,
-                  SmiTag(Signed(slot)), object_boilerplate_description, flags);
+  TailCallRuntime(Runtime::kCreateObjectLiteral, context, feedback_vector, slot,
+                  object_boilerplate_description, flags);
 }
 
 // Used by the CreateEmptyObjectLiteral bytecode and the Object constructor.
@@ -644,8 +644,8 @@ TNode<JSObject> ConstructorBuiltinsAssembler::EmitCreateEmptyObjectLiteral(
 // ES #sec-object-constructor
 TF_BUILTIN(ObjectConstructor, ConstructorBuiltinsAssembler) {
   int const kValueArg = 0;
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
@@ -694,8 +694,8 @@ TF_BUILTIN(ObjectConstructor, ConstructorBuiltinsAssembler) {
 // ES #sec-number-constructor
 TF_BUILTIN(NumberConstructor, ConstructorBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   // 1. If no arguments were passed to this function invocation, let n be +0.
diff --git a/deps/v8/src/builtins/builtins-constructor-gen.h b/deps/v8/src/builtins/builtins-constructor-gen.h
index 761a6c7adb..d6a698ddf6 100644
--- a/deps/v8/src/builtins/builtins-constructor-gen.h
+++ b/deps/v8/src/builtins/builtins-constructor-gen.h
@@ -21,30 +21,30 @@ class ConstructorBuiltinsAssembler : public CodeStubAssembler {
                                             ScopeType scope_type);
 
   TNode<JSRegExp> EmitCreateRegExpLiteral(
-      TNode<HeapObject> maybe_feedback_vector, TNode<UintPtrT> slot,
+      TNode<HeapObject> maybe_feedback_vector, TNode<TaggedIndex> slot,
       TNode<Object> pattern, TNode<Smi> flags, TNode<Context> context);
 
   TNode<JSArray> EmitCreateShallowArrayLiteral(
-      TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+      TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
       TNode<Context> context, Label* call_runtime,
       AllocationSiteMode allocation_site_mode);
 
   TNode<JSArray> EmitCreateEmptyArrayLiteral(
-      TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+      TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
       TNode<Context> context);
 
   TNode<HeapObject> EmitCreateShallowObjectLiteral(
-      TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot,
+      TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
       Label* call_runtime);
   TNode<JSObject> EmitCreateEmptyObjectLiteral(TNode<Context> context);
 
-  TNode<JSObject> EmitFastNewObject(SloppyTNode<Context> context,
-                                    SloppyTNode<JSFunction> target,
-                                    SloppyTNode<JSReceiver> new_target);
+  TNode<JSObject> EmitFastNewObject(TNode<Context> context,
+                                    TNode<JSFunction> target,
+                                    TNode<JSReceiver> new_target);
 
-  TNode<JSObject> EmitFastNewObject(SloppyTNode<Context> context,
-                                    SloppyTNode<JSFunction> target,
-                                    SloppyTNode<JSReceiver> new_target,
+  TNode<JSObject> EmitFastNewObject(TNode<Context> context,
+                                    TNode<JSFunction> target,
+                                    TNode<JSReceiver> new_target,
                                     Label* call_runtime);
 };
 
diff --git a/deps/v8/src/builtins/builtins-conversion-gen.cc b/deps/v8/src/builtins/builtins-conversion-gen.cc
index 4d0fead861..e524f39b5f 100644
--- a/deps/v8/src/builtins/builtins-conversion-gen.cc
+++ b/deps/v8/src/builtins/builtins-conversion-gen.cc
@@ -39,12 +39,9 @@ void ConversionBuiltinsAssembler::Generate_NonPrimitiveToPrimitive(
   {
     // Invoke the {exotic_to_prim} method on the {input} with a string
     // representation of the {hint}.
-    Callable callable =
-        CodeFactory::Call(isolate(), ConvertReceiverMode::kNotNullOrUndefined);
     TNode<String> hint_string =
         HeapConstant(factory()->ToPrimitiveHintString(hint));
-    TNode<Object> result =
-        CallJS(callable, context, exotic_to_prim, input, hint_string);
+    TNode<Object> result = Call(context, exotic_to_prim, input, hint_string);
 
     // Verify that the {result} is actually a primitive.
     Label if_resultisprimitive(this),
@@ -248,9 +245,7 @@ void ConversionBuiltinsAssembler::Generate_OrdinaryToPrimitive(
     BIND(&if_methodiscallable);
     {
       // Call the {method} on the {input}.
-      Callable callable = CodeFactory::Call(
-          isolate(), ConvertReceiverMode::kNotNullOrUndefined);
-      TNode<Object> result = CallJS(callable, context, method, input);
+      TNode<Object> result = Call(context, method, input);
       var_result = result;
 
       // Return the {result} if it is a primitive.
@@ -381,20 +376,6 @@ TF_BUILTIN(ToLength, CodeStubAssembler) {
   }
 }
 
-TF_BUILTIN(ToInteger, CodeStubAssembler) {
-  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  TNode<Object> input = CAST(Parameter(Descriptor::kArgument));
-
-  Return(ToInteger(context, input, kNoTruncation));
-}
-
-TF_BUILTIN(ToInteger_TruncateMinusZero, CodeStubAssembler) {
-  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-  TNode<Object> input = CAST(Parameter(Descriptor::kArgument));
-
-  Return(ToInteger(context, input, kTruncateMinusZero));
-}
-
 // ES6 section 7.1.13 ToObject (argument)
 TF_BUILTIN(ToObject, CodeStubAssembler) {
   Label if_smi(this, Label::kDeferred), if_jsreceiver(this),
diff --git a/deps/v8/src/builtins/builtins-definitions.h b/deps/v8/src/builtins/builtins-definitions.h
index 1e2cfb9a31..7ed38062c8 100644
--- a/deps/v8/src/builtins/builtins-definitions.h
+++ b/deps/v8/src/builtins/builtins-definitions.h
@@ -180,7 +180,7 @@ namespace internal {
   TFC(NewArgumentsElements, NewArgumentsElements)                              \
                                                                                \
   /* Debugger */                                                               \
-  TFJ(DebugBreakTrampoline, SharedFunctionInfo::kDontAdaptArgumentsSentinel)   \
+  TFJ(DebugBreakTrampoline, kDontAdaptArgumentsSentinel)                       \
   ASM(FrameDropperTrampoline, FrameDropperTrampoline)                          \
   ASM(HandleDebuggerStatement, ContextOnly)                                    \
                                                                                \
@@ -200,8 +200,6 @@ namespace internal {
   TFC(ToNumberConvertBigInt, TypeConversion)                                   \
   TFC(ToNumeric, TypeConversion)                                               \
   TFC(NumberToString, TypeConversion)                                          \
-  TFC(ToInteger, TypeConversion)                                               \
-  TFC(ToInteger_TruncateMinusZero, TypeConversion)                             \
   TFC(ToLength, TypeConversion)                                                \
   TFC(Typeof, Typeof)                                                          \
   TFC(GetSuperConstructor, Typeof)                                             \
@@ -311,20 +309,20 @@ namespace internal {
       kFromIndex)                                                              \
   TFS(ArrayIncludesHoleyDoubles, kElements, kSearchElement, kLength,           \
       kFromIndex)                                                              \
-  TFJ(ArrayIncludes, SharedFunctionInfo::kDontAdaptArgumentsSentinel)          \
+  TFJ(ArrayIncludes, kDontAdaptArgumentsSentinel)                              \
   /* ES6 #sec-array.prototype.indexof */                                       \
   TFS(ArrayIndexOfSmiOrObject, kElements, kSearchElement, kLength, kFromIndex) \
   TFS(ArrayIndexOfPackedDoubles, kElements, kSearchElement, kLength,           \
       kFromIndex)                                                              \
   TFS(ArrayIndexOfHoleyDoubles, kElements, kSearchElement, kLength,            \
       kFromIndex)                                                              \
-  TFJ(ArrayIndexOf, SharedFunctionInfo::kDontAdaptArgumentsSentinel)           \
+  TFJ(ArrayIndexOf, kDontAdaptArgumentsSentinel)                               \
   /* ES6 #sec-array.prototype.pop */                                           \
   CPP(ArrayPop)                                                                \
-  TFJ(ArrayPrototypePop, SharedFunctionInfo::kDontAdaptArgumentsSentinel)      \
+  TFJ(ArrayPrototypePop, kDontAdaptArgumentsSentinel)                          \
   /* ES6 #sec-array.prototype.push */                                          \
   CPP(ArrayPush)                                                               \
-  TFJ(ArrayPrototypePush, SharedFunctionInfo::kDontAdaptArgumentsSentinel)     \
+  TFJ(ArrayPrototypePush, kDontAdaptArgumentsSentinel)                         \
   /* ES6 #sec-array.prototype.shift */                                         \
   CPP(ArrayShift)                                                              \
   /* ES6 #sec-array.prototype.unshift */                                       \
@@ -346,9 +344,9 @@ namespace internal {
   TFS(FlatMapIntoArray, kTarget, kSource, kSourceLength, kStart, kDepth,       \
       kMapperFunction, kThisArg)                                               \
   /* https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flat */      \
-  TFJ(ArrayPrototypeFlat, SharedFunctionInfo::kDontAdaptArgumentsSentinel)     \
+  TFJ(ArrayPrototypeFlat, kDontAdaptArgumentsSentinel)                         \
   /* https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flatMap */   \
-  TFJ(ArrayPrototypeFlatMap, SharedFunctionInfo::kDontAdaptArgumentsSentinel)  \
+  TFJ(ArrayPrototypeFlatMap, kDontAdaptArgumentsSentinel)                      \
                                                                                \
   /* ArrayBuffer */                                                            \
   /* ES #sec-arraybuffer-constructor */                                        \
@@ -511,8 +509,7 @@ namespace internal {
   ASM(FunctionPrototypeApply, JSTrampoline)                                    \
   CPP(FunctionPrototypeBind)                                                   \
   /* ES6 #sec-function.prototype.bind */                                       \
-  TFJ(FastFunctionPrototypeBind,                                               \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(FastFunctionPrototypeBind, kDontAdaptArgumentsSentinel)                  \
   ASM(FunctionPrototypeCall, JSTrampoline)                                     \
   /* ES6 #sec-function.prototype-@@hasinstance */                              \
   TFJ(FunctionPrototypeHasInstance, 1, kReceiver, kV)                          \
@@ -526,13 +523,11 @@ namespace internal {
   TFS(CreateGeneratorObject, kClosure, kReceiver)                              \
   CPP(GeneratorFunctionConstructor)                                            \
   /* ES6 #sec-generator.prototype.next */                                      \
-  TFJ(GeneratorPrototypeNext, SharedFunctionInfo::kDontAdaptArgumentsSentinel) \
+  TFJ(GeneratorPrototypeNext, kDontAdaptArgumentsSentinel)                     \
   /* ES6 #sec-generator.prototype.return */                                    \
-  TFJ(GeneratorPrototypeReturn,                                                \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(GeneratorPrototypeReturn, kDontAdaptArgumentsSentinel)                   \
   /* ES6 #sec-generator.prototype.throw */                                     \
-  TFJ(GeneratorPrototypeThrow,                                                 \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(GeneratorPrototypeThrow, kDontAdaptArgumentsSentinel)                    \
   CPP(AsyncFunctionConstructor)                                                \
                                                                                \
   /* Iterator Protocol */                                                      \
@@ -593,7 +588,7 @@ namespace internal {
                                                                                \
   /* Map */                                                                    \
   TFS(FindOrderedHashMapEntry, kTable, kKey)                                   \
-  TFJ(MapConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)         \
+  TFJ(MapConstructor, kDontAdaptArgumentsSentinel)                             \
   TFJ(MapPrototypeSet, 2, kReceiver, kKey, kValue)                             \
   TFJ(MapPrototypeDelete, 1, kReceiver, kKey)                                  \
   TFJ(MapPrototypeGet, 1, kReceiver, kKey)                                     \
@@ -604,7 +599,7 @@ namespace internal {
   /* ES #sec-get-map.prototype.size */                                         \
   TFJ(MapPrototypeGetSize, 0, kReceiver)                                       \
   /* ES #sec-map.prototype.forEach */                                          \
-  TFJ(MapPrototypeForEach, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
+  TFJ(MapPrototypeForEach, kDontAdaptArgumentsSentinel)                        \
   /* ES #sec-map.prototype.keys */                                             \
   TFJ(MapPrototypeKeys, 0, kReceiver)                                          \
   /* ES #sec-map.prototype.values */                                           \
@@ -616,7 +611,7 @@ namespace internal {
   /* Number */                                                                 \
   TFC(AllocateHeapNumber, AllocateHeapNumber)                                  \
   /* ES #sec-number-constructor */                                             \
-  TFJ(NumberConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)      \
+  TFJ(NumberConstructor, kDontAdaptArgumentsSentinel)                          \
   /* ES6 #sec-number.isfinite */                                               \
   TFJ(NumberIsFinite, 1, kReceiver, kNumber)                                   \
   /* ES6 #sec-number.isinteger */                                              \
@@ -663,18 +658,17 @@ namespace internal {
                                                                                \
   /* Object */                                                                 \
   /* ES #sec-object-constructor */                                             \
-  TFJ(ObjectConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)      \
-  TFJ(ObjectAssign, SharedFunctionInfo::kDontAdaptArgumentsSentinel)           \
+  TFJ(ObjectConstructor, kDontAdaptArgumentsSentinel)                          \
+  TFJ(ObjectAssign, kDontAdaptArgumentsSentinel)                               \
   /* ES #sec-object.create */                                                  \
-  TFJ(ObjectCreate, SharedFunctionInfo::kDontAdaptArgumentsSentinel)           \
+  TFJ(ObjectCreate, kDontAdaptArgumentsSentinel)                               \
   CPP(ObjectDefineGetter)                                                      \
   CPP(ObjectDefineProperties)                                                  \
   CPP(ObjectDefineProperty)                                                    \
   CPP(ObjectDefineSetter)                                                      \
   TFJ(ObjectEntries, 1, kReceiver, kObject)                                    \
   CPP(ObjectFreeze)                                                            \
-  TFJ(ObjectGetOwnPropertyDescriptor,                                          \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(ObjectGetOwnPropertyDescriptor, kDontAdaptArgumentsSentinel)             \
   CPP(ObjectGetOwnPropertyDescriptors)                                         \
   TFJ(ObjectGetOwnPropertyNames, 1, kReceiver, kObject)                        \
   CPP(ObjectGetOwnPropertySymbols)                                             \
@@ -747,7 +741,7 @@ namespace internal {
   ASM(RegExpInterpreterTrampoline, CCall)                                      \
                                                                                \
   /* Set */                                                                    \
-  TFJ(SetConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)         \
+  TFJ(SetConstructor, kDontAdaptArgumentsSentinel)                             \
   TFJ(SetPrototypeHas, 1, kReceiver, kKey)                                     \
   TFJ(SetPrototypeAdd, 1, kReceiver, kKey)                                     \
   TFJ(SetPrototypeDelete, 1, kReceiver, kKey)                                  \
@@ -757,7 +751,7 @@ namespace internal {
   /* ES #sec-get-set.prototype.size */                                         \
   TFJ(SetPrototypeGetSize, 0, kReceiver)                                       \
   /* ES #sec-set.prototype.foreach */                                          \
-  TFJ(SetPrototypeForEach, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
+  TFJ(SetPrototypeForEach, kDontAdaptArgumentsSentinel)                        \
   /* ES #sec-set.prototype.values */                                           \
   TFJ(SetPrototypeValues, 0, kReceiver)                                        \
   /* ES #sec-%setiteratorprototype%.next */                                    \
@@ -786,12 +780,11 @@ namespace internal {
   /* ES #sec-string.fromcodepoint */                                           \
   CPP(StringFromCodePoint)                                                     \
   /* ES6 #sec-string.fromcharcode */                                           \
-  TFJ(StringFromCharCode, SharedFunctionInfo::kDontAdaptArgumentsSentinel)     \
+  TFJ(StringFromCharCode, kDontAdaptArgumentsSentinel)                         \
   /* ES6 #sec-string.prototype.includes */                                     \
-  TFJ(StringPrototypeIncludes,                                                 \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(StringPrototypeIncludes, kDontAdaptArgumentsSentinel)                    \
   /* ES6 #sec-string.prototype.indexof */                                      \
-  TFJ(StringPrototypeIndexOf, SharedFunctionInfo::kDontAdaptArgumentsSentinel) \
+  TFJ(StringPrototypeIndexOf, kDontAdaptArgumentsSentinel)                     \
   /* ES6 #sec-string.prototype.lastindexof */                                  \
   CPP(StringPrototypeLastIndexOf)                                              \
   /* ES6 #sec-string.prototype.match */                                        \
@@ -805,11 +798,10 @@ namespace internal {
   /* ES6 #sec-string.prototype.search */                                       \
   TFJ(StringPrototypeSearch, 1, kReceiver, kRegexp)                            \
   /* ES6 #sec-string.prototype.split */                                        \
-  TFJ(StringPrototypeSplit, SharedFunctionInfo::kDontAdaptArgumentsSentinel)   \
-  TFJ(StringPrototypeTrim, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
-  TFJ(StringPrototypeTrimEnd, SharedFunctionInfo::kDontAdaptArgumentsSentinel) \
-  TFJ(StringPrototypeTrimStart,                                                \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(StringPrototypeSplit, kDontAdaptArgumentsSentinel)                       \
+  TFJ(StringPrototypeTrim, kDontAdaptArgumentsSentinel)                        \
+  TFJ(StringPrototypeTrimEnd, kDontAdaptArgumentsSentinel)                     \
+  TFJ(StringPrototypeTrimStart, kDontAdaptArgumentsSentinel)                   \
   /* ES6 #sec-string.raw */                                                    \
   CPP(StringRaw)                                                               \
                                                                                \
@@ -825,7 +817,7 @@ namespace internal {
   /* ES #sec-typedarray-constructors */                                        \
   TFJ(TypedArrayBaseConstructor, 0, kReceiver)                                 \
   TFJ(GenericLazyDeoptContinuation, 1, kReceiver, kResult)                     \
-  TFJ(TypedArrayConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)  \
+  TFJ(TypedArrayConstructor, kDontAdaptArgumentsSentinel)                      \
   CPP(TypedArrayPrototypeBuffer)                                               \
   /* ES6 #sec-get-%typedarray%.prototype.bytelength */                         \
   TFJ(TypedArrayPrototypeByteLength, 0, kReceiver)                             \
@@ -854,14 +846,19 @@ namespace internal {
   /* ES6 #sec-get-%typedarray%.prototype-@@tostringtag */                      \
   TFJ(TypedArrayPrototypeToStringTag, 0, kReceiver)                            \
   /* ES6 %TypedArray%.prototype.map */                                         \
-  TFJ(TypedArrayPrototypeMap, SharedFunctionInfo::kDontAdaptArgumentsSentinel) \
+  TFJ(TypedArrayPrototypeMap, kDontAdaptArgumentsSentinel)                     \
                                                                                \
   /* Wasm */                                                                   \
   ASM(WasmCompileLazy, Dummy)                                                  \
+  ASM(WasmDebugBreak, Dummy)                                                   \
   TFC(WasmAtomicNotify, WasmAtomicNotify)                                      \
-  TFC(WasmI32AtomicWait, WasmI32AtomicWait)                                    \
-  TFC(WasmI64AtomicWait, WasmI64AtomicWait)                                    \
+  TFC(WasmI32AtomicWait32, WasmI32AtomicWait32)                                \
+  TFC(WasmI32AtomicWait64, WasmI32AtomicWait64)                                \
+  TFC(WasmI64AtomicWait32, WasmI64AtomicWait32)                                \
+  TFC(WasmI64AtomicWait64, WasmI64AtomicWait64)                                \
   TFC(WasmMemoryGrow, WasmMemoryGrow)                                          \
+  TFC(WasmTableInit, WasmTableInit)                                            \
+  TFC(WasmTableCopy, WasmTableCopy)                                            \
   TFC(WasmTableGet, WasmTableGet)                                              \
   TFC(WasmTableSet, WasmTableSet)                                              \
   TFC(WasmStackGuard, NoContext)                                               \
@@ -881,9 +878,11 @@ namespace internal {
   TFS(ThrowWasmTrapDataSegmentDropped)                                         \
   TFS(ThrowWasmTrapElemSegmentDropped)                                         \
   TFS(ThrowWasmTrapTableOutOfBounds)                                           \
+  TFS(ThrowWasmTrapBrOnExnNullRef)                                             \
+  TFS(ThrowWasmTrapRethrowNullRef)                                             \
                                                                                \
   /* WeakMap */                                                                \
-  TFJ(WeakMapConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)     \
+  TFJ(WeakMapConstructor, kDontAdaptArgumentsSentinel)                         \
   TFS(WeakMapLookupHashIndex, kTable, kKey)                                    \
   TFJ(WeakMapGet, 1, kReceiver, kKey)                                          \
   TFJ(WeakMapPrototypeHas, 1, kReceiver, kKey)                                 \
@@ -891,7 +890,7 @@ namespace internal {
   TFJ(WeakMapPrototypeDelete, 1, kReceiver, kKey)                              \
                                                                                \
   /* WeakSet */                                                                \
-  TFJ(WeakSetConstructor, SharedFunctionInfo::kDontAdaptArgumentsSentinel)     \
+  TFJ(WeakSetConstructor, kDontAdaptArgumentsSentinel)                         \
   TFJ(WeakSetPrototypeHas, 1, kReceiver, kKey)                                 \
   TFJ(WeakSetPrototypeAdd, 1, kReceiver, kValue)                               \
   TFJ(WeakSetPrototypeDelete, 1, kReceiver, kValue)                            \
@@ -913,16 +912,13 @@ namespace internal {
   CPP(AsyncGeneratorFunctionConstructor)                                       \
   /* AsyncGenerator.prototype.next ( value ) */                                \
   /* proposal-async-iteration/#sec-asyncgenerator-prototype-next */            \
-  TFJ(AsyncGeneratorPrototypeNext,                                             \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(AsyncGeneratorPrototypeNext, kDontAdaptArgumentsSentinel)                \
   /* AsyncGenerator.prototype.return ( value ) */                              \
   /* proposal-async-iteration/#sec-asyncgenerator-prototype-return */          \
-  TFJ(AsyncGeneratorPrototypeReturn,                                           \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(AsyncGeneratorPrototypeReturn, kDontAdaptArgumentsSentinel)              \
   /* AsyncGenerator.prototype.throw ( exception ) */                           \
   /* proposal-async-iteration/#sec-asyncgenerator-prototype-throw */           \
-  TFJ(AsyncGeneratorPrototypeThrow,                                            \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                         \
+  TFJ(AsyncGeneratorPrototypeThrow, kDontAdaptArgumentsSentinel)               \
                                                                                \
   /* Await (proposal-async-iteration/#await), with resume behaviour */         \
   /* specific to Async Generators. Internal / Not exposed to JS code. */       \
@@ -980,16 +976,16 @@ namespace internal {
   CPP(Trace)                                                                   \
                                                                                \
   /* Weak refs */                                                              \
-  CPP(FinalizationGroupCleanupIteratorNext)                                    \
-  CPP(FinalizationGroupCleanupSome)                                            \
-  CPP(FinalizationGroupConstructor)                                            \
-  CPP(FinalizationGroupRegister)                                               \
-  CPP(FinalizationGroupUnregister)                                             \
+  CPP(FinalizationRegistryCleanupIteratorNext)                                 \
+  CPP(FinalizationRegistryCleanupSome)                                         \
+  CPP(FinalizationRegistryConstructor)                                         \
+  CPP(FinalizationRegistryRegister)                                            \
+  CPP(FinalizationRegistryUnregister)                                          \
   CPP(WeakRefConstructor)                                                      \
   CPP(WeakRefDeref)                                                            \
                                                                                \
   /* Async modules */                                                          \
-  TFJ(AsyncModuleEvaluate, SharedFunctionInfo::kDontAdaptArgumentsSentinel)    \
+  TFJ(AsyncModuleEvaluate, kDontAdaptArgumentsSentinel)                        \
                                                                                \
   /* CallAsyncModule* are spec anonymyous functions */                         \
   CPP(CallAsyncModuleFulfilled)                                                \
@@ -1041,11 +1037,9 @@ namespace internal {
   /* ecma402 #sec-intl-listformat-constructor */                       \
   CPP(ListFormatConstructor)                                           \
   /* ecma402 #sec-intl-list-format.prototype.format */                 \
-  TFJ(ListFormatPrototypeFormat,                                       \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                 \
+  TFJ(ListFormatPrototypeFormat, kDontAdaptArgumentsSentinel)          \
   /* ecma402 #sec-intl-list-format.prototype.formattoparts */          \
-  TFJ(ListFormatPrototypeFormatToParts,                                \
-      SharedFunctionInfo::kDontAdaptArgumentsSentinel)                 \
+  TFJ(ListFormatPrototypeFormatToParts, kDontAdaptArgumentsSentinel)   \
   /* ecma402 #sec-intl.listformat.prototype.resolvedoptions */         \
   CPP(ListFormatPrototypeResolvedOptions)                              \
   /* ecma402 #sec-intl.ListFormat.supportedlocalesof */                \
diff --git a/deps/v8/src/builtins/builtins-descriptors.h b/deps/v8/src/builtins/builtins-descriptors.h
index c2eb44debe..174b89795f 100644
--- a/deps/v8/src/builtins/builtins-descriptors.h
+++ b/deps/v8/src/builtins/builtins-descriptors.h
@@ -13,7 +13,34 @@
 namespace v8 {
 namespace internal {
 
+#define REVERSE_0(a) a,
+#define REVERSE_1(a, b) b, a,
+#define REVERSE_2(a, b, c) c, b, a,
+#define REVERSE_3(a, b, c, d) d, c, b, a,
+#define REVERSE_4(a, b, c, d, e) e, d, c, b, a,
+#define REVERSE_5(a, b, c, d, e, f) f, e, d, c, b, a,
+#define REVERSE_6(a, b, c, d, e, f, g) g, f, e, d, c, b, a,
+#define REVERSE_7(a, b, c, d, e, f, g, h) h, g, f, e, d, c, b, a,
+#define REVERSE_8(a, b, c, d, e, f, g, h, i) i, h, g, f, e, d, c, b, a,
+#define REVERSE_kDontAdaptArgumentsSentinel(...)
+#define REVERSE(N, ...) REVERSE_##N(__VA_ARGS__)
+
 // Define interface descriptors for builtins with JS linkage.
+#ifdef V8_REVERSE_JSARGS
+#define DEFINE_TFJ_INTERFACE_DESCRIPTOR(Name, Argc, ...)                \
+  struct Builtin_##Name##_InterfaceDescriptor {                         \
+    enum ParameterIndices {                                             \
+      kJSTarget = compiler::CodeAssembler::kTargetParameterIndex,       \
+      REVERSE_##Argc(__VA_ARGS__) kJSNewTarget,                         \
+      kJSActualArgumentsCount,                                          \
+      kContext,                                                         \
+      kParameterCount,                                                  \
+    };                                                                  \
+    static_assert((Argc) == static_cast<uint16_t>(kParameterCount - 4), \
+                  "Inconsistent set of arguments");                     \
+    static_assert(kJSTarget == -1, "Unexpected kJSTarget index value"); \
+  };
+#else
 #define DEFINE_TFJ_INTERFACE_DESCRIPTOR(Name, Argc, ...)                \
   struct Builtin_##Name##_InterfaceDescriptor {                         \
     enum ParameterIndices {                                             \
@@ -28,6 +55,7 @@ namespace internal {
                   "Inconsistent set of arguments");                     \
     static_assert(kJSTarget == -1, "Unexpected kJSTarget index value"); \
   };
+#endif
 
 // Define interface descriptors for builtins with StubCall linkage.
 #define DEFINE_TFC_INTERFACE_DESCRIPTOR(Name, InterfaceDescriptor) \
diff --git a/deps/v8/src/builtins/builtins-generator-gen.cc b/deps/v8/src/builtins/builtins-generator-gen.cc
index 689c7f1342..8693cd61f4 100644
--- a/deps/v8/src/builtins/builtins-generator-gen.cc
+++ b/deps/v8/src/builtins/builtins-generator-gen.cc
@@ -56,12 +56,16 @@ void GeneratorBuiltinsAssembler::InnerResume(
                                  SmiConstant(resume_mode));
 
   // Resume the {receiver} using our trampoline.
+  // Close the generator if there was an exception.
   TVARIABLE(Object, var_exception);
   Label if_exception(this, Label::kDeferred), if_final_return(this);
-  TNode<Object> result = CallStub(CodeFactory::ResumeGenerator(isolate()),
-                                  context, value, receiver);
-  // Make sure we close the generator if there was an exception.
-  GotoIfException(result, &if_exception, &var_exception);
+  TNode<Object> result;
+  {
+    compiler::ScopedExceptionHandler handler(this, &if_exception,
+                                             &var_exception);
+    result = CallStub(CodeFactory::ResumeGenerator(isolate()), context, value,
+                      receiver);
+  }
 
   // If the generator is not suspended (i.e., its state is 'executing'),
   // close it and wrap the return value in IteratorResult.
diff --git a/deps/v8/src/builtins/builtins-internal-gen.cc b/deps/v8/src/builtins/builtins-internal-gen.cc
index 880f665c02..6f4f54656d 100644
--- a/deps/v8/src/builtins/builtins-internal-gen.cc
+++ b/deps/v8/src/builtins/builtins-internal-gen.cc
@@ -42,7 +42,7 @@ TF_BUILTIN(CopyFastSmiOrObjectElements, CodeStubAssembler) {
 
 TF_BUILTIN(GrowFastDoubleElements, CodeStubAssembler) {
   TNode<JSObject> object = CAST(Parameter(Descriptor::kObject));
-  TNode<Number> key = CAST(Parameter(Descriptor::kKey));
+  TNode<Smi> key = CAST(Parameter(Descriptor::kKey));
 
   Label runtime(this, Label::kDeferred);
   TNode<FixedArrayBase> elements = LoadElements(object);
@@ -57,7 +57,7 @@ TF_BUILTIN(GrowFastDoubleElements, CodeStubAssembler) {
 
 TF_BUILTIN(GrowFastSmiOrObjectElements, CodeStubAssembler) {
   TNode<JSObject> object = CAST(Parameter(Descriptor::kObject));
-  TNode<Number> key = CAST(Parameter(Descriptor::kKey));
+  TNode<Smi> key = CAST(Parameter(Descriptor::kKey));
 
   Label runtime(this, Label::kDeferred);
   TNode<FixedArrayBase> elements = LoadElements(object);
@@ -266,11 +266,11 @@ class RecordWriteCodeStubAssembler : public CodeStubAssembler {
     }
   }
 
-  TNode<BoolT> ShouldSkipFPRegs(SloppyTNode<Smi> mode) {
+  TNode<BoolT> ShouldSkipFPRegs(TNode<Smi> mode) {
     return TaggedEqual(mode, SmiConstant(kDontSaveFPRegs));
   }
 
-  TNode<BoolT> ShouldEmitRememberSet(SloppyTNode<Smi> remembered_set) {
+  TNode<BoolT> ShouldEmitRememberSet(TNode<Smi> remembered_set) {
     return TaggedEqual(remembered_set, SmiConstant(EMIT_REMEMBERED_SET));
   }
 
@@ -766,7 +766,7 @@ TF_BUILTIN(SetDataProperties, SetOrCopyDataPropertiesAssembler) {
 }
 
 TF_BUILTIN(ForInEnumerate, CodeStubAssembler) {
-  TNode<HeapObject> receiver = CAST(Parameter(Descriptor::kReceiver));
+  TNode<JSReceiver> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Label if_empty(this), if_runtime(this, Label::kDeferred);
diff --git a/deps/v8/src/builtins/builtins-iterator-gen.cc b/deps/v8/src/builtins/builtins-iterator-gen.cc
index e9dca2dbc3..94a79d2a32 100644
--- a/deps/v8/src/builtins/builtins-iterator-gen.cc
+++ b/deps/v8/src/builtins/builtins-iterator-gen.cc
@@ -23,53 +23,38 @@ TNode<Object> IteratorBuiltinsAssembler::GetIteratorMethod(
   return GetProperty(context, object, factory()->iterator_symbol());
 }
 
-IteratorRecord IteratorBuiltinsAssembler::GetIterator(
-    SloppyTNode<Context> context, SloppyTNode<Object> object,
-    Label* if_exception, TVariable<Object>* exception) {
+IteratorRecord IteratorBuiltinsAssembler::GetIterator(TNode<Context> context,
+                                                      TNode<Object> object) {
   TNode<Object> method = GetIteratorMethod(context, object);
-  return GetIterator(context, object, method, if_exception, exception);
+  return GetIterator(context, object, method);
 }
 
-IteratorRecord IteratorBuiltinsAssembler::GetIterator(
-    TNode<Context> context, TNode<Object> object, TNode<Object> method,
-    Label* if_exception, TVariable<Object>* exception) {
-  GotoIfException(method, if_exception, exception);
-
+IteratorRecord IteratorBuiltinsAssembler::GetIterator(TNode<Context> context,
+                                                      TNode<Object> object,
+                                                      TNode<Object> method) {
   Label if_not_callable(this, Label::kDeferred), if_callable(this);
   GotoIf(TaggedIsSmi(method), &if_not_callable);
   Branch(IsCallable(CAST(method)), &if_callable, &if_not_callable);
 
   BIND(&if_not_callable);
-  {
-    TNode<Object> ret =
-        CallRuntime(Runtime::kThrowIteratorError, context, object);
-    GotoIfException(ret, if_exception, exception);
-    Unreachable();
-  }
+  CallRuntime(Runtime::kThrowIteratorError, context, object);
+  Unreachable();
 
   BIND(&if_callable);
   {
-    Callable callable = CodeFactory::Call(isolate());
-    TNode<Object> iterator = CallJS(callable, context, method, object);
-    GotoIfException(iterator, if_exception, exception);
+    TNode<Object> iterator = Call(context, method, object);
 
     Label get_next(this), if_notobject(this, Label::kDeferred);
     GotoIf(TaggedIsSmi(iterator), &if_notobject);
     Branch(IsJSReceiver(CAST(iterator)), &get_next, &if_notobject);
 
     BIND(&if_notobject);
-    {
-      TNode<Object> ret =
-          CallRuntime(Runtime::kThrowSymbolIteratorInvalid, context);
-      GotoIfException(ret, if_exception, exception);
-      Unreachable();
-    }
+    CallRuntime(Runtime::kThrowSymbolIteratorInvalid, context);
+    Unreachable();
 
     BIND(&get_next);
-    const TNode<Object> next =
+    TNode<Object> next =
         GetProperty(context, iterator, factory()->next_string());
-    GotoIfException(next, if_exception, exception);
-
     return IteratorRecord{TNode<JSReceiver>::UncheckedCast(iterator),
                           TNode<Object>::UncheckedCast(next)};
   }
@@ -77,14 +62,10 @@ IteratorRecord IteratorBuiltinsAssembler::GetIterator(
 
 TNode<JSReceiver> IteratorBuiltinsAssembler::IteratorStep(
     TNode<Context> context, const IteratorRecord& iterator, Label* if_done,
-    base::Optional<TNode<Map>> fast_iterator_result_map, Label* if_exception,
-    TVariable<Object>* exception) {
+    base::Optional<TNode<Map>> fast_iterator_result_map) {
   DCHECK_NOT_NULL(if_done);
   // 1. a. Let result be ? Invoke(iterator, "next", « »).
-  Callable callable = CodeFactory::Call(isolate());
-  TNode<Object> result =
-      CallJS(callable, context, iterator.next, iterator.object);
-  GotoIfException(result, if_exception, exception);
+  TNode<Object> result = Call(context, iterator.next, iterator.object);
 
   // 3. If Type(result) is not Object, throw a TypeError exception.
   Label if_notobject(this, Label::kDeferred), return_result(this);
@@ -117,17 +98,12 @@ TNode<JSReceiver> IteratorBuiltinsAssembler::IteratorStep(
     // 2. Return ToBoolean(? Get(iterResult, "done")).
     TNode<Object> done =
         GetProperty(context, heap_object_result, factory()->done_string());
-    GotoIfException(done, if_exception, exception);
     BranchIfToBooleanIsTrue(done, if_done, &return_result);
   }
 
   BIND(&if_notobject);
-  {
-    TNode<Object> ret =
-        CallRuntime(Runtime::kThrowIteratorResultNotAnObject, context, result);
-    GotoIfException(ret, if_exception, exception);
-    Unreachable();
-  }
+  CallRuntime(Runtime::kThrowIteratorResultNotAnObject, context, result);
+  Unreachable();
 
   BIND(&return_result);
   return CAST(heap_object_result);
@@ -135,8 +111,7 @@ TNode<JSReceiver> IteratorBuiltinsAssembler::IteratorStep(
 
 TNode<Object> IteratorBuiltinsAssembler::IteratorValue(
     TNode<Context> context, TNode<JSReceiver> result,
-    base::Optional<TNode<Map>> fast_iterator_result_map, Label* if_exception,
-    TVariable<Object>* exception) {
+    base::Optional<TNode<Map>> fast_iterator_result_map) {
   Label exit(this);
   TVARIABLE(Object, var_value);
   if (fast_iterator_result_map) {
@@ -151,13 +126,8 @@ TNode<Object> IteratorBuiltinsAssembler::IteratorValue(
   }
 
   // Generic iterator result case:
-  {
-    TNode<Object> value =
-        GetProperty(context, result, factory()->value_string());
-    GotoIfException(value, if_exception, exception);
-    var_value = value;
-    Goto(&exit);
-  }
+  var_value = GetProperty(context, result, factory()->value_string());
+  Goto(&exit);
 
   BIND(&exit);
   return var_value.value();
@@ -174,23 +144,24 @@ void IteratorBuiltinsAssembler::IteratorCloseOnException(
   CSA_ASSERT(this, IsJSReceiver(iterator.object));
 
   // Let return be ? GetMethod(iterator, "return").
-  TNode<Object> method =
-      GetProperty(context, iterator.object, factory()->return_string());
-  GotoIfException(method, if_exception, exception);
+  TNode<Object> method;
+  {
+    compiler::ScopedExceptionHandler handler(this, if_exception, exception);
+    method = GetProperty(context, iterator.object, factory()->return_string());
+  }
 
   // If return is undefined, return Completion(completion).
   GotoIf(Word32Or(IsUndefined(method), IsNull(method)), if_exception);
 
   {
     // Let innerResult be Call(return, iterator, « »).
-    // If an exception occurs, the original exception remains bound
-    TNode<Object> inner_result =
-        CallJS(CodeFactory::Call(isolate()), context, method, iterator.object);
-    GotoIfException(inner_result, if_exception, nullptr);
-
-    // (If completion.[[Type]] is throw) return Completion(completion).
-    Goto(if_exception);
+    // If an exception occurs, the original exception remains bound.
+    compiler::ScopedExceptionHandler handler(this, if_exception, nullptr);
+    Call(context, method, iterator.object);
   }
+
+  // (If completion.[[Type]] is throw) return Completion(completion).
+  Goto(if_exception);
 }
 
 void IteratorBuiltinsAssembler::IteratorCloseOnException(
@@ -317,10 +288,13 @@ TNode<JSArray> IteratorBuiltinsAssembler::StringListFromIterable(
     {
       // 1. Let error be ThrowCompletion(a newly created TypeError object).
       TVARIABLE(Object, var_exception);
-      TNode<Object> ret = CallRuntime(
-          Runtime::kThrowTypeError, context,
-          SmiConstant(MessageTemplate::kIterableYieldedNonString), next_value);
-      GotoIfException(ret, &if_exception, &var_exception);
+      {
+        compiler::ScopedExceptionHandler handler(this, &if_exception,
+                                                 &var_exception);
+        CallRuntime(Runtime::kThrowTypeError, context,
+                    SmiConstant(MessageTemplate::kIterableYieldedNonString),
+                    next_value);
+      }
       Unreachable();
 
       // 2. Return ? IteratorClose(iteratorRecord, error).
@@ -466,13 +440,15 @@ TF_BUILTIN(GetIteratorWithFeedbackLazyDeoptContinuation,
            IteratorBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
-  TNode<Smi> callSlot = CAST(Parameter(Descriptor::kCallSlot));
+  // TODO(v8:10047): Use TaggedIndex here once TurboFan supports it.
+  TNode<Smi> call_slot_smi = CAST(Parameter(Descriptor::kCallSlot));
+  TNode<TaggedIndex> call_slot = SmiToTaggedIndex(call_slot_smi);
   TNode<FeedbackVector> feedback = CAST(Parameter(Descriptor::kFeedback));
-  TNode<Object> iteratorMethod = CAST(Parameter(Descriptor::kResult));
+  TNode<Object> iterator_method = CAST(Parameter(Descriptor::kResult));
 
   TNode<Object> result =
       CallBuiltin(Builtins::kCallIteratorWithFeedback, context, receiver,
-                  iteratorMethod, callSlot, feedback);
+                  iterator_method, call_slot, feedback);
   Return(result);
 }
 
diff --git a/deps/v8/src/builtins/builtins-iterator-gen.h b/deps/v8/src/builtins/builtins-iterator-gen.h
index 61665d2825..4d496fa384 100644
--- a/deps/v8/src/builtins/builtins-iterator-gen.h
+++ b/deps/v8/src/builtins/builtins-iterator-gen.h
@@ -24,14 +24,9 @@ class IteratorBuiltinsAssembler : public CodeStubAssembler {
 
   // https://tc39.github.io/ecma262/#sec-getiterator --- never used for
   // @@asyncIterator.
-  IteratorRecord GetIterator(SloppyTNode<Context> context,
-                             SloppyTNode<Object> object,
-                             Label* if_exception = nullptr,
-                             TVariable<Object>* exception = nullptr);
+  IteratorRecord GetIterator(TNode<Context> context, TNode<Object> object);
   IteratorRecord GetIterator(TNode<Context> context, TNode<Object> object,
-                             TNode<Object> method,
-                             Label* if_exception = nullptr,
-                             TVariable<Object>* exception = nullptr);
+                             TNode<Object> method);
 
   // https://tc39.github.io/ecma262/#sec-iteratorstep
   // If the iterator is done, goto {if_done}, otherwise returns an iterator
@@ -40,9 +35,7 @@ class IteratorBuiltinsAssembler : public CodeStubAssembler {
   // object, loaded from the native context.
   TNode<JSReceiver> IteratorStep(
       TNode<Context> context, const IteratorRecord& iterator, Label* if_done,
-      base::Optional<TNode<Map>> fast_iterator_result_map = base::nullopt,
-      Label* if_exception = nullptr, TVariable<Object>* exception = nullptr);
-
+      base::Optional<TNode<Map>> fast_iterator_result_map = base::nullopt);
   TNode<JSReceiver> IteratorStep(
       TNode<Context> context, const IteratorRecord& iterator,
       base::Optional<TNode<Map>> fast_iterator_result_map, Label* if_done) {
@@ -55,8 +48,7 @@ class IteratorBuiltinsAssembler : public CodeStubAssembler {
   // object, loaded from the native context.
   TNode<Object> IteratorValue(
       TNode<Context> context, TNode<JSReceiver> result,
-      base::Optional<TNode<Map>> fast_iterator_result_map = base::nullopt,
-      Label* if_exception = nullptr, TVariable<Object>* exception = nullptr);
+      base::Optional<TNode<Map>> fast_iterator_result_map = base::nullopt);
 
   // https://tc39.github.io/ecma262/#sec-iteratorclose
   void IteratorCloseOnException(TNode<Context> context,
diff --git a/deps/v8/src/builtins/builtins-microtask-queue-gen.cc b/deps/v8/src/builtins/builtins-microtask-queue-gen.cc
index 630d65e72c..917255f9bb 100644
--- a/deps/v8/src/builtins/builtins-microtask-queue-gen.cc
+++ b/deps/v8/src/builtins/builtins-microtask-queue-gen.cc
@@ -14,6 +14,8 @@
 namespace v8 {
 namespace internal {
 
+using compiler::ScopedExceptionHandler;
+
 class MicrotaskQueueBuiltinsAssembler : public CodeStubAssembler {
  public:
   explicit MicrotaskQueueBuiltinsAssembler(compiler::CodeAssemblerState* state)
@@ -45,7 +47,7 @@ class MicrotaskQueueBuiltinsAssembler : public CodeStubAssembler {
   void RewindEnteredContext(TNode<IntPtrT> saved_entered_context_count);
 
   void RunPromiseHook(Runtime::FunctionId id, TNode<Context> context,
-                      SloppyTNode<HeapObject> promise_or_capability);
+                      TNode<HeapObject> promise_or_capability);
 };
 
 TNode<RawPtrT> MicrotaskQueueBuiltinsAssembler::GetMicrotaskQueue(
@@ -118,7 +120,7 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
   TNode<Map> microtask_map = LoadMap(microtask);
   TNode<Uint16T> microtask_type = LoadMapInstanceType(microtask_map);
 
-  TVARIABLE(HeapObject, var_exception, TheHoleConstant());
+  TVARIABLE(Object, var_exception);
   Label if_exception(this, Label::kDeferred);
   Label is_callable(this), is_callback(this),
       is_promise_fulfill_reaction_job(this),
@@ -147,10 +149,10 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
 
     TNode<JSReceiver> callable =
         LoadObjectField<JSReceiver>(microtask, CallableTask::kCallableOffset);
-    const TNode<Object> result = CallJS(
-        CodeFactory::Call(isolate(), ConvertReceiverMode::kNullOrUndefined),
-        microtask_context, callable, UndefinedConstant());
-    GotoIfException(result, &if_exception, &var_exception);
+    {
+      ScopedExceptionHandler handler(this, &if_exception, &var_exception);
+      Call(microtask_context, callable, UndefinedConstant());
+    }
     RewindEnteredContext(saved_entered_context_count);
     SetCurrentContext(current_context);
     Goto(&done);
@@ -173,10 +175,11 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     // But from our current measurements it doesn't seem to be a
     // serious performance problem, even if the microtask is full
     // of CallHandlerTasks (which is not a realistic use case anyways).
-    const TNode<Object> result =
-        CallRuntime(Runtime::kRunMicrotaskCallback, current_context,
-                    microtask_callback, microtask_data);
-    GotoIfException(result, &if_exception, &var_exception);
+    {
+      ScopedExceptionHandler handler(this, &if_exception, &var_exception);
+      CallRuntime(Runtime::kRunMicrotaskCallback, current_context,
+                  microtask_callback, microtask_data);
+    }
     Goto(&done);
   }
 
@@ -195,10 +198,11 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     const TNode<Object> thenable = LoadObjectField(
         microtask, PromiseResolveThenableJobTask::kThenableOffset);
 
-    const TNode<Object> result =
-        CallBuiltin(Builtins::kPromiseResolveThenableJob, native_context,
-                    promise_to_resolve, thenable, then);
-    GotoIfException(result, &if_exception, &var_exception);
+    {
+      ScopedExceptionHandler handler(this, &if_exception, &var_exception);
+      CallBuiltin(Builtins::kPromiseResolveThenableJob, native_context,
+                  promise_to_resolve, thenable, then);
+    }
     RewindEnteredContext(saved_entered_context_count);
     SetCurrentContext(current_context);
     Goto(&done);
@@ -214,24 +218,44 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
 
     const TNode<Object> argument =
         LoadObjectField(microtask, PromiseReactionJobTask::kArgumentOffset);
-    const TNode<Object> handler =
+    const TNode<Object> job_handler =
         LoadObjectField(microtask, PromiseReactionJobTask::kHandlerOffset);
     const TNode<HeapObject> promise_or_capability = CAST(LoadObjectField(
         microtask, PromiseReactionJobTask::kPromiseOrCapabilityOffset));
 
+    TNode<Object> preserved_embedder_data = LoadObjectField(
+        microtask,
+        PromiseReactionJobTask::kContinuationPreservedEmbedderDataOffset);
+    Label preserved_data_done(this);
+    GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_done);
+    StoreContextElement(native_context,
+                        Context::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX,
+                        preserved_embedder_data);
+    Goto(&preserved_data_done);
+    BIND(&preserved_data_done);
+
     // Run the promise before/debug hook if enabled.
     RunPromiseHook(Runtime::kPromiseHookBefore, microtask_context,
                    promise_or_capability);
 
-    const TNode<Object> result =
-        CallBuiltin(Builtins::kPromiseFulfillReactionJob, microtask_context,
-                    argument, handler, promise_or_capability);
-    GotoIfException(result, &if_exception, &var_exception);
+    {
+      ScopedExceptionHandler handler(this, &if_exception, &var_exception);
+      CallBuiltin(Builtins::kPromiseFulfillReactionJob, microtask_context,
+                  argument, job_handler, promise_or_capability);
+    }
 
     // Run the promise after/debug hook if enabled.
     RunPromiseHook(Runtime::kPromiseHookAfter, microtask_context,
                    promise_or_capability);
 
+    Label preserved_data_reset_done(this);
+    GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_reset_done);
+    StoreContextElement(native_context,
+                        Context::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX,
+                        UndefinedConstant());
+    Goto(&preserved_data_reset_done);
+    BIND(&preserved_data_reset_done);
+
     RewindEnteredContext(saved_entered_context_count);
     SetCurrentContext(current_context);
     Goto(&done);
@@ -247,24 +271,44 @@ void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
 
     const TNode<Object> argument =
         LoadObjectField(microtask, PromiseReactionJobTask::kArgumentOffset);
-    const TNode<Object> handler =
+    const TNode<Object> job_handler =
         LoadObjectField(microtask, PromiseReactionJobTask::kHandlerOffset);
     const TNode<HeapObject> promise_or_capability = CAST(LoadObjectField(
         microtask, PromiseReactionJobTask::kPromiseOrCapabilityOffset));
 
+    TNode<Object> preserved_embedder_data = LoadObjectField(
+        microtask,
+        PromiseReactionJobTask::kContinuationPreservedEmbedderDataOffset);
+    Label preserved_data_done(this);
+    GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_done);
+    StoreContextElement(native_context,
+                        Context::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX,
+                        preserved_embedder_data);
+    Goto(&preserved_data_done);
+    BIND(&preserved_data_done);
+
     // Run the promise before/debug hook if enabled.
     RunPromiseHook(Runtime::kPromiseHookBefore, microtask_context,
                    promise_or_capability);
 
-    const TNode<Object> result =
-        CallBuiltin(Builtins::kPromiseRejectReactionJob, microtask_context,
-                    argument, handler, promise_or_capability);
-    GotoIfException(result, &if_exception, &var_exception);
+    {
+      ScopedExceptionHandler handler(this, &if_exception, &var_exception);
+      CallBuiltin(Builtins::kPromiseRejectReactionJob, microtask_context,
+                  argument, job_handler, promise_or_capability);
+    }
 
     // Run the promise after/debug hook if enabled.
     RunPromiseHook(Runtime::kPromiseHookAfter, microtask_context,
                    promise_or_capability);
 
+    Label preserved_data_reset_done(this);
+    GotoIf(IsUndefined(preserved_embedder_data), &preserved_data_reset_done);
+    StoreContextElement(native_context,
+                        Context::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX,
+                        UndefinedConstant());
+    Goto(&preserved_data_reset_done);
+    BIND(&preserved_data_reset_done);
+
     RewindEnteredContext(saved_entered_context_count);
     SetCurrentContext(current_context);
     Goto(&done);
@@ -415,7 +459,7 @@ void MicrotaskQueueBuiltinsAssembler::RewindEnteredContext(
 
 void MicrotaskQueueBuiltinsAssembler::RunPromiseHook(
     Runtime::FunctionId id, TNode<Context> context,
-    SloppyTNode<HeapObject> promise_or_capability) {
+    TNode<HeapObject> promise_or_capability) {
   Label hook(this, Label::kDeferred), done_hook(this);
   Branch(IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate(), &hook,
          &done_hook);
diff --git a/deps/v8/src/builtins/builtins-object-gen.cc b/deps/v8/src/builtins/builtins-object-gen.cc
index 9c5cd54613..9af4affa68 100644
--- a/deps/v8/src/builtins/builtins-object-gen.cc
+++ b/deps/v8/src/builtins/builtins-object-gen.cc
@@ -359,7 +359,7 @@ TF_BUILTIN(ObjectPrototypeToLocaleString, CodeStubAssembler) {
 
   TNode<Object> method =
       GetProperty(context, receiver, factory()->toString_string());
-  Return(CallJS(CodeFactory::Call(isolate()), context, method, receiver));
+  Return(Call(context, method, receiver));
 
   BIND(&if_null_or_undefined);
   ThrowTypeError(context, MessageTemplate::kCalledOnNullOrUndefined,
@@ -380,7 +380,9 @@ TF_BUILTIN(ObjectPrototypeHasOwnProperty, ObjectBuiltinsAssembler) {
   Branch(TaggedIsSmi(object), &to_primitive, &if_objectisnotsmi);
   BIND(&if_objectisnotsmi);
 
-  TNode<Map> map = LoadMap(CAST(object));
+  TNode<HeapObject> heap_object = CAST(object);
+
+  TNode<Map> map = LoadMap(heap_object);
   TNode<Uint16T> instance_type = LoadMapInstanceType(map);
 
   {
@@ -393,12 +395,12 @@ TF_BUILTIN(ObjectPrototypeHasOwnProperty, ObjectBuiltinsAssembler) {
               &call_runtime, &if_notunique_name);
 
     BIND(&if_unique_name);
-    TryHasOwnProperty(object, map, instance_type, var_unique.value(),
+    TryHasOwnProperty(heap_object, map, instance_type, var_unique.value(),
                       &return_true, &return_false, &call_runtime);
 
     BIND(&if_index);
     {
-      TryLookupElement(CAST(object), map, instance_type, var_index.value(),
+      TryLookupElement(heap_object, map, instance_type, var_index.value(),
                        &return_true, &return_false, &return_false,
                        &call_runtime);
     }
@@ -435,8 +437,8 @@ TF_BUILTIN(ObjectPrototypeHasOwnProperty, ObjectBuiltinsAssembler) {
 
 // ES #sec-object.assign
 TF_BUILTIN(ObjectAssign, ObjectBuiltinsAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
@@ -502,8 +504,8 @@ TF_BUILTIN(ObjectKeys, ObjectBuiltinsAssembler) {
     TNode<DescriptorArray> object_descriptors = LoadMapDescriptors(object_map);
     TNode<EnumCache> object_enum_cache = LoadObjectField<EnumCache>(
         object_descriptors, DescriptorArray::kEnumCacheOffset);
-    TNode<Object> object_enum_keys =
-        LoadObjectField(object_enum_cache, EnumCache::kKeysOffset);
+    auto object_enum_keys = LoadObjectField<FixedArrayBase>(
+        object_enum_cache, EnumCache::kKeysOffset);
 
     // Allocate a JSArray and copy the elements from the {object_enum_keys}.
     TNode<JSArray> array;
@@ -598,8 +600,8 @@ TF_BUILTIN(ObjectGetOwnPropertyNames, ObjectBuiltinsAssembler) {
     TNode<DescriptorArray> object_descriptors = LoadMapDescriptors(object_map);
     TNode<EnumCache> object_enum_cache = CAST(
         LoadObjectField(object_descriptors, DescriptorArray::kEnumCacheOffset));
-    TNode<Object> object_enum_keys =
-        LoadObjectField(object_enum_cache, EnumCache::kKeysOffset);
+    auto object_enum_keys = LoadObjectField<FixedArrayBase>(
+        object_enum_cache, EnumCache::kKeysOffset);
 
     // Allocate a JSArray and copy the elements from the {object_enum_keys}.
     TNode<NativeContext> native_context = LoadNativeContext(context);
@@ -1064,8 +1066,8 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
   int const kPrototypeArg = 0;
   int const kPropertiesArg = 1;
 
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Object> prototype = args.GetOptionalArgumentValue(kPrototypeArg);
diff --git a/deps/v8/src/builtins/builtins-promise-gen.cc b/deps/v8/src/builtins/builtins-promise-gen.cc
index 6b1f43d8ea..c48fc0f78f 100644
--- a/deps/v8/src/builtins/builtins-promise-gen.cc
+++ b/deps/v8/src/builtins/builtins-promise-gen.cc
@@ -28,11 +28,6 @@ void PromiseBuiltinsAssembler::ZeroOutEmbedderOffsets(
   }
 }
 
-TNode<HeapObject> PromiseBuiltinsAssembler::AllocatePromiseReactionJobTask(
-    TNode<Context> context) {
-  return Allocate(PromiseReactionJobTask::kSizeOfAllPromiseReactionJobTasks);
-}
-
 TNode<HeapObject> PromiseBuiltinsAssembler::AllocateJSPromise(
     TNode<Context> context) {
   return Allocate(JSPromise::kSizeWithEmbedderFields);
diff --git a/deps/v8/src/builtins/builtins-promise-gen.h b/deps/v8/src/builtins/builtins-promise-gen.h
index 66044b51af..377db4d9e3 100644
--- a/deps/v8/src/builtins/builtins-promise-gen.h
+++ b/deps/v8/src/builtins/builtins-promise-gen.h
@@ -20,8 +20,6 @@ class V8_EXPORT_PRIVATE PromiseBuiltinsAssembler : public CodeStubAssembler {
   void ZeroOutEmbedderOffsets(TNode<JSPromise> promise);
 
   TNode<HeapObject> AllocateJSPromise(TNode<Context> context);
-
-  TNode<HeapObject> AllocatePromiseReactionJobTask(TNode<Context> context);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-proxy-gen.cc b/deps/v8/src/builtins/builtins-proxy-gen.cc
index c0901953d1..caafcf6506 100644
--- a/deps/v8/src/builtins/builtins-proxy-gen.cc
+++ b/deps/v8/src/builtins/builtins-proxy-gen.cc
@@ -126,8 +126,7 @@ TF_BUILTIN(CallProxy, ProxiesCodeStubAssembler) {
                               UncheckedCast<IntPtrT>(argc_ptr));
 
   // 8. Return Call(trap, handler, «target, thisArgument, argArray»).
-  TNode<Object> result = CallJS(CodeFactory::Call(isolate()), context, trap,
-                                handler, target, receiver, array);
+  TNode<Object> result = Call(context, trap, handler, target, receiver, array);
   args.PopAndReturn(result);
 
   BIND(&trap_undefined);
@@ -181,8 +180,8 @@ TF_BUILTIN(ConstructProxy, ProxiesCodeStubAssembler) {
                               UncheckedCast<IntPtrT>(argc_ptr));
 
   // 8. Let newObj be ? Call(trap, handler, « target, argArray, newTarget »).
-  TNode<Object> new_obj = CallJS(CodeFactory::Call(isolate()), context, trap,
-                                 handler, target, array, new_target);
+  TNode<Object> new_obj =
+      Call(context, trap, handler, target, array, new_target);
 
   // 9. If Type(newObj) is not Object, throw a TypeError exception.
   GotoIf(TaggedIsSmi(new_obj), &not_an_object);
diff --git a/deps/v8/src/builtins/builtins-regexp-gen.cc b/deps/v8/src/builtins/builtins-regexp-gen.cc
index 792f0e44a6..d06ced76d2 100644
--- a/deps/v8/src/builtins/builtins-regexp-gen.cc
+++ b/deps/v8/src/builtins/builtins-regexp-gen.cc
@@ -164,9 +164,9 @@ void RegExpBuiltinsAssembler::FastStoreLastIndex(TNode<JSRegExp> regexp,
   StoreObjectField(regexp, field_offset, value);
 }
 
-void RegExpBuiltinsAssembler::SlowStoreLastIndex(SloppyTNode<Context> context,
-                                                 SloppyTNode<Object> regexp,
-                                                 SloppyTNode<Object> value) {
+void RegExpBuiltinsAssembler::SlowStoreLastIndex(TNode<Context> context,
+                                                 TNode<Object> regexp,
+                                                 TNode<Object> value) {
   TNode<String> name = HeapConstant(isolate()->factory()->lastIndex_string());
   SetPropertyStrict(context, regexp, name, value);
 }
@@ -1237,8 +1237,8 @@ TNode<BoolT> RegExpBuiltinsAssembler::FlagGetter(TNode<Context> context,
 }
 
 TNode<Number> RegExpBuiltinsAssembler::AdvanceStringIndex(
-    SloppyTNode<String> string, SloppyTNode<Number> index,
-    SloppyTNode<BoolT> is_unicode, bool is_fastpath) {
+    TNode<String> string, TNode<Number> index, TNode<BoolT> is_unicode,
+    bool is_fastpath) {
   CSA_ASSERT(this, IsString(string));
   CSA_ASSERT(this, IsNumberNormalized(index));
   if (is_fastpath) CSA_ASSERT(this, TaggedIsPositiveSmi(index));
diff --git a/deps/v8/src/builtins/builtins-regexp-gen.h b/deps/v8/src/builtins/builtins-regexp-gen.h
index c12ed63722..273e315599 100644
--- a/deps/v8/src/builtins/builtins-regexp-gen.h
+++ b/deps/v8/src/builtins/builtins-regexp-gen.h
@@ -37,9 +37,8 @@ class RegExpBuiltinsAssembler : public CodeStubAssembler {
   TNode<Object> SlowLoadLastIndex(TNode<Context> context, TNode<Object> regexp);
 
   void FastStoreLastIndex(TNode<JSRegExp> regexp, TNode<Smi> value);
-  void SlowStoreLastIndex(SloppyTNode<Context> context,
-                          SloppyTNode<Object> regexp,
-                          SloppyTNode<Object> value);
+  void SlowStoreLastIndex(TNode<Context> context, TNode<Object> regexp,
+                          TNode<Object> value);
 
   // Loads {var_string_start} and {var_string_end} with the corresponding
   // offsets into the given {string_data}.
@@ -140,10 +139,8 @@ class RegExpBuiltinsAssembler : public CodeStubAssembler {
                                  const TNode<Object> maybe_pattern,
                                  const TNode<Object> maybe_flags);
 
-  TNode<Number> AdvanceStringIndex(SloppyTNode<String> string,
-                                   SloppyTNode<Number> index,
-                                   SloppyTNode<BoolT> is_unicode,
-                                   bool is_fastpath);
+  TNode<Number> AdvanceStringIndex(TNode<String> string, TNode<Number> index,
+                                   TNode<BoolT> is_unicode, bool is_fastpath);
 
   TNode<Smi> AdvanceStringIndexFast(TNode<String> string, TNode<Smi> index,
                                     TNode<BoolT> is_unicode) {
diff --git a/deps/v8/src/builtins/builtins-sharedarraybuffer.cc b/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
index e6251c9480..f89bc25bdb 100644
--- a/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
+++ b/deps/v8/src/builtins/builtins-sharedarraybuffer.cc
@@ -25,20 +25,18 @@ namespace internal {
 // #sec-atomics.islockfree
 inline bool AtomicIsLockFree(double size) {
   // According to the standard, 1, 2, and 4 byte atomics are supposed to be
-  // 'lock free' on every platform. But what exactly does 'lock free' mean?
-  // For example, on x64 V8 uses a lock prefix to implement the semantics of
-  // many atomic operations. Is that considered a lock? Probably not.
+  // 'lock free' on every platform. 'Lock free' means that all possible uses of
+  // those atomics guarantee forward progress for the agent cluster (i.e. all
+  // threads in contrast with a single thread).
   //
-  // On the other hand, V8 emits a few instructions for some arm atomics which
-  // do appear to be a low level form of a spin lock. With an abundance of
-  // caution, we only claim to have 'true lock free' support for 8 byte sizes
-  // on x64 platforms. If people care about this function returning true, then
-  // we need to clarify exactly what 'lock free' means at the standard level.
-  bool is_lock_free = size == 1 || size == 2 || size == 4;
-#if V8_TARGET_ARCH_x64
-  is_lock_free |= size == 8;
-#endif
-  return is_lock_free;
+  // This property is often, but not always, aligned with whether atomic
+  // accesses are implemented with software locks such as mutexes.
+  //
+  // V8 has lock free atomics for all sizes on all supported first-class
+  // architectures: ia32, x64, ARM32 variants, and ARM64. Further, this property
+  // is depended upon by WebAssembly, which prescribes that all atomic accesses
+  // are always lock free.
+  return size == 1 || size == 2 || size == 4 || size == 8;
 }
 
 // ES #sec-atomics.islockfree
diff --git a/deps/v8/src/builtins/builtins-string-gen.cc b/deps/v8/src/builtins/builtins-string-gen.cc
index 5fe534879a..e2d1635274 100644
--- a/deps/v8/src/builtins/builtins-string-gen.cc
+++ b/deps/v8/src/builtins/builtins-string-gen.cc
@@ -973,7 +973,7 @@ void StringBuiltinsAssembler::StringIndexOf(
       const TNode<IntPtrT> search_length =
           IntPtrSub(subject_length, start_position);
       const TNode<IntPtrT> search_byte =
-          ChangeInt32ToIntPtr(Load(MachineType::Uint8(), adjusted_search_ptr));
+          ChangeInt32ToIntPtr(Load<Uint8T>(adjusted_search_ptr));
 
       const TNode<ExternalReference> memchr =
           ExternalConstant(ExternalReference::libc_memchr_function());
@@ -1074,8 +1074,8 @@ TF_BUILTIN(StringIndexOf, StringBuiltinsAssembler) {
 // ES6 String.prototype.includes(searchString [, position])
 // #sec-string.prototype.includes
 TF_BUILTIN(StringPrototypeIncludes, StringIncludesIndexOfAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   Generate(kIncludes, argc, context);
 }
@@ -1083,8 +1083,8 @@ TF_BUILTIN(StringPrototypeIncludes, StringIncludesIndexOfAssembler) {
 // ES6 String.prototype.indexOf(searchString [, position])
 // #sec-string.prototype.indexof
 TF_BUILTIN(StringPrototypeIndexOf, StringIncludesIndexOfAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   Generate(kIndexOf, argc, context);
 }
@@ -1293,8 +1293,7 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
                            replace));
       },
       [=](TNode<Object> fn) {
-        Callable call_callable = CodeFactory::Call(isolate());
-        Return(CallJS(call_callable, context, fn, search, receiver, replace));
+        Return(Call(context, fn, search, receiver, replace));
       });
 
   // Convert {receiver} and {search} to strings.
@@ -1394,10 +1393,9 @@ TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
 
   BIND(&if_iscallablereplace);
   {
-    Callable call_callable = CodeFactory::Call(isolate());
     const TNode<Object> replacement =
-        CallJS(call_callable, context, replace, UndefinedConstant(),
-               search_string, match_start_index, subject_string);
+        Call(context, replace, UndefinedConstant(), search_string,
+             match_start_index, subject_string);
     const TNode<String> replacement_string =
         ToString_Inline(context, replacement);
     var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
@@ -1463,8 +1461,7 @@ class StringMatchSearchAssembler : public StringBuiltinsAssembler {
         context, maybe_regexp, receiver, symbol, property_to_check,
         [=] { Return(CallBuiltin(builtin, context, maybe_regexp, receiver)); },
         [=](TNode<Object> fn) {
-          Callable call_callable = CodeFactory::Call(isolate());
-          Return(CallJS(call_callable, context, fn, maybe_regexp, receiver));
+          Return(Call(context, fn, maybe_regexp, receiver));
         });
 
     // maybe_regexp is not a RegExp nor has [@@match / @@search] property.
@@ -1494,9 +1491,7 @@ class StringMatchSearchAssembler : public StringBuiltinsAssembler {
       BIND(&slow_path);
       {
         TNode<Object> maybe_func = GetProperty(context, regexp, symbol);
-        Callable call_callable = CodeFactory::Call(isolate());
-        Return(CallJS(call_callable, context, maybe_func, regexp,
-                      receiver_string));
+        Return(Call(context, maybe_func, regexp, receiver_string));
       }
     }
   }
@@ -1588,8 +1583,7 @@ TF_BUILTIN(StringPrototypeMatchAll, StringBuiltinsAssembler) {
         RegExpPrototypeMatchAllImpl(context, native_context, maybe_regexp, s));
   };
   auto if_generic_call = [=](TNode<Object> fn) {
-    Callable call_callable = CodeFactory::Call(isolate());
-    Return(CallJS(call_callable, context, fn, maybe_regexp, receiver));
+    Return(Call(context, fn, maybe_regexp, receiver));
   };
   MaybeCallFunctionAtSymbol(
       context, maybe_regexp, receiver, isolate()->factory()->match_all_symbol(),
@@ -1606,10 +1600,9 @@ TF_BUILTIN(StringPrototypeMatchAll, StringBuiltinsAssembler) {
                                              maybe_regexp, StringConstant("g"));
 
   // 5. Return ? Invoke(rx, @@matchAll, « S »).
-  Callable callable = CodeFactory::Call(isolate());
   TNode<Object> match_all_func =
       GetProperty(context, rx, isolate()->factory()->match_all_symbol());
-  Return(CallJS(callable, context, match_all_func, rx, s));
+  Return(Call(context, match_all_func, rx, s));
 }
 
 // ES6 #sec-string.prototype.search
@@ -1699,8 +1692,8 @@ TF_BUILTIN(StringPrototypeSplit, StringBuiltinsAssembler) {
   const int kSeparatorArg = 0;
   const int kLimitArg = 1;
 
-  const TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  const TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
 
   TNode<Object> receiver = args.GetReceiver();
@@ -1724,9 +1717,7 @@ TF_BUILTIN(StringPrototypeSplit, StringBuiltinsAssembler) {
                                       separator, receiver, limit));
       },
       [&](TNode<Object> fn) {
-        Callable call_callable = CodeFactory::Call(isolate());
-        args.PopAndReturn(
-            CallJS(call_callable, context, fn, separator, receiver, limit));
+        args.PopAndReturn(Call(context, fn, separator, receiver, limit));
       });
 
   // String and integer conversions.
@@ -1808,8 +1799,8 @@ TF_BUILTIN(StringSubstring, StringBuiltinsAssembler) {
 
 // ES6 #sec-string.prototype.trim
 TF_BUILTIN(StringPrototypeTrim, StringTrimAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Generate(String::kTrim, "String.prototype.trim", argc, context);
@@ -1817,8 +1808,8 @@ TF_BUILTIN(StringPrototypeTrim, StringTrimAssembler) {
 
 // https://github.com/tc39/proposal-string-left-right-trim
 TF_BUILTIN(StringPrototypeTrimStart, StringTrimAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Generate(String::kTrimStart, "String.prototype.trimLeft", argc, context);
@@ -1826,8 +1817,8 @@ TF_BUILTIN(StringPrototypeTrimStart, StringTrimAssembler) {
 
 // https://github.com/tc39/proposal-string-left-right-trim
 TF_BUILTIN(StringPrototypeTrimEnd, StringTrimAssembler) {
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Generate(String::kTrimEnd, "String.prototype.trimRight", argc, context);
diff --git a/deps/v8/src/builtins/builtins-string.tq b/deps/v8/src/builtins/builtins-string.tq
index 3ef8fc2a9b..61cd984e7f 100644
--- a/deps/v8/src/builtins/builtins-string.tq
+++ b/deps/v8/src/builtins/builtins-string.tq
@@ -68,7 +68,7 @@ namespace string {
     const string: String = ToThisString(receiver, methodName);
 
     // 3. Let position be ? ToInteger(pos).
-    const indexNumber: Number = ToInteger_Inline(position, kTruncateMinusZero);
+    const indexNumber: Number = ToInteger_Inline(position);
 
     // Convert the {position} to a uintptr and check that it's in bounds of
     // the {string}.
diff --git a/deps/v8/src/builtins/builtins-typed-array-gen.cc b/deps/v8/src/builtins/builtins-typed-array-gen.cc
index 23339fa1c8..021a0e9240 100644
--- a/deps/v8/src/builtins/builtins-typed-array-gen.cc
+++ b/deps/v8/src/builtins/builtins-typed-array-gen.cc
@@ -89,8 +89,8 @@ TF_BUILTIN(TypedArrayConstructor, TypedArrayBuiltinsAssembler) {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<JSFunction> target = CAST(Parameter(Descriptor::kJSTarget));
   TNode<Object> new_target = CAST(Parameter(Descriptor::kJSNewTarget));
-  TNode<IntPtrT> argc =
-      ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount));
+  TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
+      UncheckedCast<Int32T>(Parameter(Descriptor::kJSActualArgumentsCount)));
   CodeStubArguments args(this, argc);
   TNode<Object> arg1 = args.GetOptionalArgumentValue(0);
   TNode<Object> arg2 = args.GetOptionalArgumentValue(1);
@@ -378,13 +378,6 @@ void TypedArrayBuiltinsAssembler::DispatchTypedArrayByElementsKind(
   BIND(&next);
 }
 
-TNode<BoolT> TypedArrayBuiltinsAssembler::IsSharedArrayBuffer(
-    TNode<JSArrayBuffer> buffer) {
-  TNode<Uint32T> bitfield =
-      LoadObjectField<Uint32T>(buffer, JSArrayBuffer::kBitFieldOffset);
-  return IsSetWord32<JSArrayBuffer::IsSharedBit>(bitfield);
-}
-
 void TypedArrayBuiltinsAssembler::SetJSTypedArrayOnHeapDataPtr(
     TNode<JSTypedArray> holder, TNode<ByteArray> base, TNode<UintPtrT> offset) {
   offset = UintPtrAdd(UintPtrConstant(ByteArray::kHeaderSize - kHeapObjectTag),
diff --git a/deps/v8/src/builtins/builtins-typed-array-gen.h b/deps/v8/src/builtins/builtins-typed-array-gen.h
index 7424020596..1008b6bdd7 100644
--- a/deps/v8/src/builtins/builtins-typed-array-gen.h
+++ b/deps/v8/src/builtins/builtins-typed-array-gen.h
@@ -85,8 +85,6 @@ class TypedArrayBuiltinsAssembler : public CodeStubAssembler {
   void DispatchTypedArrayByElementsKind(
       TNode<Word32T> elements_kind, const TypedArraySwitchCase& case_function);
 
-  TNode<BoolT> IsSharedArrayBuffer(TNode<JSArrayBuffer> buffer);
-
   void SetJSTypedArrayOnHeapDataPtr(TNode<JSTypedArray> holder,
                                     TNode<ByteArray> base,
                                     TNode<UintPtrT> offset);
diff --git a/deps/v8/src/builtins/builtins-utils-inl.h b/deps/v8/src/builtins/builtins-utils-inl.h
index c8c9a2522c..82d5fe2873 100644
--- a/deps/v8/src/builtins/builtins-utils-inl.h
+++ b/deps/v8/src/builtins/builtins-utils-inl.h
@@ -23,11 +23,21 @@ Handle<Object> BuiltinArguments::atOrUndefined(Isolate* isolate,
 Handle<Object> BuiltinArguments::receiver() const { return at<Object>(0); }
 
 Handle<JSFunction> BuiltinArguments::target() const {
-  return Arguments::at<JSFunction>(Arguments::length() - 1 - kTargetOffset);
+#ifdef V8_REVERSE_JSARGS
+  int index = kTargetOffset;
+#else
+  int index = Arguments::length() - 1 - kTargetOffset;
+#endif
+  return Handle<JSFunction>(address_of_arg_at(index));
 }
 
 Handle<HeapObject> BuiltinArguments::new_target() const {
-  return Arguments::at<HeapObject>(Arguments::length() - 1 - kNewTargetOffset);
+#ifdef V8_REVERSE_JSARGS
+  int index = kNewTargetOffset;
+#else
+  int index = Arguments::length() - 1 - kNewTargetOffset;
+#endif
+  return Handle<JSFunction>(address_of_arg_at(index));
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/builtins/builtins-utils.h b/deps/v8/src/builtins/builtins-utils.h
index 601dfd5813..3bed3bc651 100644
--- a/deps/v8/src/builtins/builtins-utils.h
+++ b/deps/v8/src/builtins/builtins-utils.h
@@ -15,7 +15,7 @@ namespace v8 {
 namespace internal {
 
 // Arguments object passed to C++ builtins.
-class BuiltinArguments : public Arguments {
+class BuiltinArguments : public JavaScriptArguments {
  public:
   BuiltinArguments(int length, Address* arguments)
       : Arguments(length, arguments) {
@@ -25,13 +25,24 @@ class BuiltinArguments : public Arguments {
 
   Object operator[](int index) const {
     DCHECK_LT(index, length());
-    return Arguments::operator[](index);
+    return Object(*address_of_arg_at(index + kArgsOffset));
   }
 
   template <class S = Object>
   Handle<S> at(int index) const {
     DCHECK_LT(index, length());
-    return Arguments::at<S>(index);
+    return Handle<S>(address_of_arg_at(index + kArgsOffset));
+  }
+
+  inline void set_at(int index, Object value) {
+    DCHECK_LT(index, length());
+    *address_of_arg_at(index + kArgsOffset) = value.ptr();
+  }
+
+  // Note: this should return the address after the receiver,
+  // even when length() == 1.
+  inline Address* address_of_first_argument() const {
+    return address_of_arg_at(kArgsOffset + 1);  // Skips receiver.
   }
 
   static constexpr int kNewTargetOffset = 0;
@@ -42,6 +53,12 @@ class BuiltinArguments : public Arguments {
   static constexpr int kNumExtraArgs = 4;
   static constexpr int kNumExtraArgsWithReceiver = 5;
 
+#ifdef V8_REVERSE_JSARGS
+  static constexpr int kArgsOffset = 4;
+#else
+  static constexpr int kArgsOffset = 0;
+#endif
+
   inline Handle<Object> atOrUndefined(Isolate* isolate, int index) const;
   inline Handle<Object> receiver() const;
   inline Handle<JSFunction> target() const;
diff --git a/deps/v8/src/builtins/builtins-wasm-gen.cc b/deps/v8/src/builtins/builtins-wasm-gen.cc
index 0f5d86e646..770f5da97b 100644
--- a/deps/v8/src/builtins/builtins-wasm-gen.cc
+++ b/deps/v8/src/builtins/builtins-wasm-gen.cc
@@ -28,6 +28,13 @@ class WasmBuiltinsAssembler : public CodeStubAssembler {
                      IntPtrConstant(WasmInstanceObject::kNativeContextOffset -
                                     kHeapObjectTag)));
   }
+
+  TNode<Smi> SmiFromUint32WithSaturation(TNode<Uint32T> value, uint32_t max) {
+    DCHECK_LE(max, static_cast<uint32_t>(Smi::kMaxValue));
+    TNode<Uint32T> capped_value = SelectConstant(
+        Uint32LessThan(value, Uint32Constant(max)), value, Uint32Constant(max));
+    return SmiFromUint32(capped_value);
+  }
 };
 
 TF_BUILTIN(WasmStackGuard, WasmBuiltinsAssembler) {
@@ -53,7 +60,16 @@ TF_BUILTIN(WasmRethrow, WasmBuiltinsAssembler) {
   TNode<Object> exception = CAST(Parameter(Descriptor::kException));
   TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
   TNode<Context> context = LoadContextFromInstance(instance);
+
+  Label nullref(this, Label::kDeferred);
+  GotoIf(TaggedEqual(NullConstant(), exception), &nullref);
+
   TailCallRuntime(Runtime::kReThrow, context, exception);
+
+  BIND(&nullref);
+  MessageTemplate message_id = MessageTemplate::kWasmTrapRethrowNullRef;
+  TailCallRuntime(Runtime::kThrowWasmError, context,
+                  SmiConstant(static_cast<int>(message_id)));
 }
 
 TF_BUILTIN(WasmTraceMemory, WasmBuiltinsAssembler) {
@@ -79,48 +95,118 @@ TF_BUILTIN(WasmAtomicNotify, WasmBuiltinsAssembler) {
   Return(Unsigned(SmiToInt32(result_smi)));
 }
 
-TF_BUILTIN(WasmI32AtomicWait, WasmBuiltinsAssembler) {
+TF_BUILTIN(WasmI32AtomicWait32, WasmBuiltinsAssembler) {
+  if (!Is32()) {
+    Unreachable();
+    return;
+  }
+
   TNode<Uint32T> address =
       UncheckedCast<Uint32T>(Parameter(Descriptor::kAddress));
+  TNode<Number> address_number = ChangeUint32ToTagged(address);
+
   TNode<Int32T> expected_value =
       UncheckedCast<Int32T>(Parameter(Descriptor::kExpectedValue));
-  TNode<Float64T> timeout =
-      UncheckedCast<Float64T>(Parameter(Descriptor::kTimeout));
+  TNode<Number> expected_value_number = ChangeInt32ToTagged(expected_value);
+
+  TNode<IntPtrT> timeout_low =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeoutLow));
+  TNode<IntPtrT> timeout_high =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeoutHigh));
+  TNode<BigInt> timeout = BigIntFromInt32Pair(timeout_low, timeout_high);
 
   TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
+  TNode<Context> context = LoadContextFromInstance(instance);
+
+  TNode<Smi> result_smi =
+      CAST(CallRuntime(Runtime::kWasmI32AtomicWait, context, instance,
+                       address_number, expected_value_number, timeout));
+  Return(Unsigned(SmiToInt32(result_smi)));
+}
+
+TF_BUILTIN(WasmI32AtomicWait64, WasmBuiltinsAssembler) {
+  if (!Is64()) {
+    Unreachable();
+    return;
+  }
+
+  TNode<Uint32T> address =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kAddress));
   TNode<Number> address_number = ChangeUint32ToTagged(address);
+
+  TNode<Int32T> expected_value =
+      UncheckedCast<Int32T>(Parameter(Descriptor::kExpectedValue));
   TNode<Number> expected_value_number = ChangeInt32ToTagged(expected_value);
-  TNode<Number> timeout_number = ChangeFloat64ToTagged(timeout);
+
+  TNode<IntPtrT> timeout_raw =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeout));
+  TNode<BigInt> timeout = BigIntFromInt64(timeout_raw);
+
+  TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
   TNode<Context> context = LoadContextFromInstance(instance);
 
   TNode<Smi> result_smi =
       CAST(CallRuntime(Runtime::kWasmI32AtomicWait, context, instance,
-                       address_number, expected_value_number, timeout_number));
+                       address_number, expected_value_number, timeout));
   Return(Unsigned(SmiToInt32(result_smi)));
 }
 
-TF_BUILTIN(WasmI64AtomicWait, WasmBuiltinsAssembler) {
+TF_BUILTIN(WasmI64AtomicWait32, WasmBuiltinsAssembler) {
+  if (!Is32()) {
+    Unreachable();
+    return;
+  }
+
   TNode<Uint32T> address =
       UncheckedCast<Uint32T>(Parameter(Descriptor::kAddress));
-  TNode<Uint32T> expected_value_high =
-      UncheckedCast<Uint32T>(Parameter(Descriptor::kExpectedValueHigh));
-  TNode<Uint32T> expected_value_low =
-      UncheckedCast<Uint32T>(Parameter(Descriptor::kExpectedValueLow));
-  TNode<Float64T> timeout =
-      UncheckedCast<Float64T>(Parameter(Descriptor::kTimeout));
+  TNode<Number> address_number = ChangeUint32ToTagged(address);
+
+  TNode<IntPtrT> expected_value_low =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kExpectedValueLow));
+  TNode<IntPtrT> expected_value_high =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kExpectedValueHigh));
+  TNode<BigInt> expected_value =
+      BigIntFromInt32Pair(expected_value_low, expected_value_high);
+
+  TNode<IntPtrT> timeout_low =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeoutLow));
+  TNode<IntPtrT> timeout_high =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeoutHigh));
+  TNode<BigInt> timeout = BigIntFromInt32Pair(timeout_low, timeout_high);
 
   TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
+  TNode<Context> context = LoadContextFromInstance(instance);
+
+  TNode<Smi> result_smi =
+      CAST(CallRuntime(Runtime::kWasmI64AtomicWait, context, instance,
+                       address_number, expected_value, timeout));
+  Return(Unsigned(SmiToInt32(result_smi)));
+}
+
+TF_BUILTIN(WasmI64AtomicWait64, WasmBuiltinsAssembler) {
+  if (!Is64()) {
+    Unreachable();
+    return;
+  }
+
+  TNode<Uint32T> address =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kAddress));
   TNode<Number> address_number = ChangeUint32ToTagged(address);
-  TNode<Number> expected_value_high_number =
-      ChangeUint32ToTagged(expected_value_high);
-  TNode<Number> expected_value_low_number =
-      ChangeUint32ToTagged(expected_value_low);
-  TNode<Number> timeout_number = ChangeFloat64ToTagged(timeout);
+
+  TNode<IntPtrT> expected_value_raw =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kExpectedValue));
+  TNode<BigInt> expected_value = BigIntFromInt64(expected_value_raw);
+
+  TNode<IntPtrT> timeout_raw =
+      UncheckedCast<IntPtrT>(Parameter(Descriptor::kTimeout));
+  TNode<BigInt> timeout = BigIntFromInt64(timeout_raw);
+
+  TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
   TNode<Context> context = LoadContextFromInstance(instance);
 
-  TNode<Smi> result_smi = CAST(CallRuntime(
-      Runtime::kWasmI64AtomicWait, context, instance, address_number,
-      expected_value_high_number, expected_value_low_number, timeout_number));
+  TNode<Smi> result_smi =
+      CAST(CallRuntime(Runtime::kWasmI64AtomicWait, context, instance,
+                       address_number, expected_value, timeout));
   Return(Unsigned(SmiToInt32(result_smi)));
 }
 
@@ -144,6 +230,66 @@ TF_BUILTIN(WasmMemoryGrow, WasmBuiltinsAssembler) {
   Return(Int32Constant(-1));
 }
 
+TF_BUILTIN(WasmTableInit, WasmBuiltinsAssembler) {
+  TNode<Uint32T> dst_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kDestination));
+  // We cap {dst}, {src}, and {size} by {wasm::kV8MaxWasmTableSize + 1} to make
+  // sure that the values fit into a Smi.
+  STATIC_ASSERT(static_cast<size_t>(Smi::kMaxValue) >=
+                wasm::kV8MaxWasmTableSize + 1);
+  constexpr uint32_t kCap =
+      static_cast<uint32_t>(wasm::kV8MaxWasmTableSize + 1);
+  TNode<Smi> dst = SmiFromUint32WithSaturation(dst_raw, kCap);
+  TNode<Uint32T> src_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kSource));
+  TNode<Smi> src = SmiFromUint32WithSaturation(src_raw, kCap);
+  TNode<Uint32T> size_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kSize));
+  TNode<Smi> size = SmiFromUint32WithSaturation(size_raw, kCap);
+  TNode<Smi> table_index =
+      UncheckedCast<Smi>(Parameter(Descriptor::kTableIndex));
+  TNode<Smi> segment_index =
+      UncheckedCast<Smi>(Parameter(Descriptor::kSegmentIndex));
+  TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
+  TNode<Context> context = LoadContextFromInstance(instance);
+
+  TailCallRuntime(Runtime::kWasmTableInit, context, instance, table_index,
+                  segment_index, dst, src, size);
+}
+
+TF_BUILTIN(WasmTableCopy, WasmBuiltinsAssembler) {
+  // We cap {dst}, {src}, and {size} by {wasm::kV8MaxWasmTableSize + 1} to make
+  // sure that the values fit into a Smi.
+  STATIC_ASSERT(static_cast<size_t>(Smi::kMaxValue) >=
+                wasm::kV8MaxWasmTableSize + 1);
+  constexpr uint32_t kCap =
+      static_cast<uint32_t>(wasm::kV8MaxWasmTableSize + 1);
+
+  TNode<Uint32T> dst_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kDestination));
+  TNode<Smi> dst = SmiFromUint32WithSaturation(dst_raw, kCap);
+
+  TNode<Uint32T> src_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kSource));
+  TNode<Smi> src = SmiFromUint32WithSaturation(src_raw, kCap);
+
+  TNode<Uint32T> size_raw =
+      UncheckedCast<Uint32T>(Parameter(Descriptor::kSize));
+  TNode<Smi> size = SmiFromUint32WithSaturation(size_raw, kCap);
+
+  TNode<Smi> dst_table =
+      UncheckedCast<Smi>(Parameter(Descriptor::kDestinationTable));
+
+  TNode<Smi> src_table =
+      UncheckedCast<Smi>(Parameter(Descriptor::kSourceTable));
+
+  TNode<WasmInstanceObject> instance = LoadInstanceFromFrame();
+  TNode<Context> context = LoadContextFromInstance(instance);
+
+  TailCallRuntime(Runtime::kWasmTableCopy, context, instance, dst_table,
+                  src_table, dst, src, size);
+}
+
 TF_BUILTIN(WasmTableGet, WasmBuiltinsAssembler) {
   TNode<Int32T> entry_index =
       UncheckedCast<Int32T>(Parameter(Descriptor::kEntryIndex));
diff --git a/deps/v8/src/builtins/builtins-weak-refs.cc b/deps/v8/src/builtins/builtins-weak-refs.cc
index 28fb9c9cbd..e75c7fae9d 100644
--- a/deps/v8/src/builtins/builtins-weak-refs.cc
+++ b/deps/v8/src/builtins/builtins-weak-refs.cc
@@ -9,7 +9,7 @@
 namespace v8 {
 namespace internal {
 
-BUILTIN(FinalizationGroupConstructor) {
+BUILTIN(FinalizationRegistryConstructor) {
   HandleScope scope(isolate);
   Handle<JSFunction> target = args.target();
   if (args.new_target()->IsUndefined(isolate)) {  // [[Call]]
@@ -31,22 +31,22 @@ BUILTIN(FinalizationGroupConstructor) {
       isolate, result,
       JSObject::New(target, new_target, Handle<AllocationSite>::null()));
 
-  Handle<JSFinalizationGroup> finalization_group =
-      Handle<JSFinalizationGroup>::cast(result);
-  finalization_group->set_native_context(*isolate->native_context());
-  finalization_group->set_cleanup(*cleanup);
-  finalization_group->set_flags(
-      JSFinalizationGroup::ScheduledForCleanupField::encode(false));
-
-  DCHECK(finalization_group->active_cells().IsUndefined(isolate));
-  DCHECK(finalization_group->cleared_cells().IsUndefined(isolate));
-  DCHECK(finalization_group->key_map().IsUndefined(isolate));
-  return *finalization_group;
+  Handle<JSFinalizationRegistry> finalization_registry =
+      Handle<JSFinalizationRegistry>::cast(result);
+  finalization_registry->set_native_context(*isolate->native_context());
+  finalization_registry->set_cleanup(*cleanup);
+  finalization_registry->set_flags(
+      JSFinalizationRegistry::ScheduledForCleanupField::encode(false));
+
+  DCHECK(finalization_registry->active_cells().IsUndefined(isolate));
+  DCHECK(finalization_registry->cleared_cells().IsUndefined(isolate));
+  DCHECK(finalization_registry->key_map().IsUndefined(isolate));
+  return *finalization_registry;
 }
 
-BUILTIN(FinalizationGroupRegister) {
+BUILTIN(FinalizationRegistryRegister) {
   HandleScope scope(isolate);
-  const char* method_name = "FinalizationGroup.prototype.register";
+  const char* method_name = "FinalizationRegistry.prototype.register";
 
   //  1. Let finalizationGroup be the this value.
   //
@@ -55,7 +55,7 @@ BUILTIN(FinalizationGroupRegister) {
   //
   //  4. If finalizationGroup does not have a [[Cells]] internal slot,
   //  throw a TypeError exception.
-  CHECK_RECEIVER(JSFinalizationGroup, finalization_group, method_name);
+  CHECK_RECEIVER(JSFinalizationRegistry, finalization_registry, method_name);
 
   Handle<Object> target = args.atOrUndefined(isolate, 1);
 
@@ -86,15 +86,15 @@ BUILTIN(FinalizationGroupRegister) {
   }
   // TODO(marja): Realms.
 
-  JSFinalizationGroup::Register(finalization_group,
-                                Handle<JSReceiver>::cast(target), holdings,
-                                unregister_token, isolate);
+  JSFinalizationRegistry::Register(finalization_registry,
+                                   Handle<JSReceiver>::cast(target), holdings,
+                                   unregister_token, isolate);
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-BUILTIN(FinalizationGroupUnregister) {
+BUILTIN(FinalizationRegistryUnregister) {
   HandleScope scope(isolate);
-  const char* method_name = "FinalizationGroup.prototype.unregister";
+  const char* method_name = "FinalizationRegistry.prototype.unregister";
 
   // 1. Let finalizationGroup be the this value.
   //
@@ -103,7 +103,7 @@ BUILTIN(FinalizationGroupUnregister) {
   //
   // 3. If finalizationGroup does not have a [[Cells]] internal slot,
   //    throw a TypeError exception.
-  CHECK_RECEIVER(JSFinalizationGroup, finalization_group, method_name);
+  CHECK_RECEIVER(JSFinalizationRegistry, finalization_registry, method_name);
 
   Handle<Object> unregister_token = args.atOrUndefined(isolate, 1);
 
@@ -115,15 +115,16 @@ BUILTIN(FinalizationGroupUnregister) {
                      unregister_token));
   }
 
-  bool success = JSFinalizationGroup::Unregister(
-      finalization_group, Handle<JSReceiver>::cast(unregister_token), isolate);
+  bool success = JSFinalizationRegistry::Unregister(
+      finalization_registry, Handle<JSReceiver>::cast(unregister_token),
+      isolate);
 
   return *isolate->factory()->ToBoolean(success);
 }
 
-BUILTIN(FinalizationGroupCleanupSome) {
+BUILTIN(FinalizationRegistryCleanupSome) {
   HandleScope scope(isolate);
-  const char* method_name = "FinalizationGroup.prototype.cleanupSome";
+  const char* method_name = "FinalizationRegistry.prototype.cleanupSome";
 
   // 1. Let finalizationGroup be the this value.
   //
@@ -132,9 +133,9 @@ BUILTIN(FinalizationGroupCleanupSome) {
   //
   // 3. If finalizationGroup does not have a [[Cells]] internal slot,
   //    throw a TypeError exception.
-  CHECK_RECEIVER(JSFinalizationGroup, finalization_group, method_name);
+  CHECK_RECEIVER(JSFinalizationRegistry, finalization_registry, method_name);
 
-  Handle<Object> callback(finalization_group->cleanup(), isolate);
+  Handle<Object> callback(finalization_registry->cleanup(), isolate);
   Handle<Object> callback_obj = args.atOrUndefined(isolate, 1);
 
   // 4. If callback is not undefined and IsCallable(callback) is
@@ -148,10 +149,9 @@ BUILTIN(FinalizationGroupCleanupSome) {
     callback = callback_obj;
   }
 
-  // Don't do set_scheduled_for_cleanup(false); we still have the microtask
-  // scheduled and don't want to schedule another one in case the user never
-  // executes microtasks.
-  if (JSFinalizationGroup::Cleanup(isolate, finalization_group, callback)
+  // Don't do set_scheduled_for_cleanup(false); we still have the task
+  // scheduled.
+  if (JSFinalizationRegistry::Cleanup(isolate, finalization_registry, callback)
           .IsNothing()) {
     DCHECK(isolate->has_pending_exception());
     return ReadOnlyRoots(isolate).exception();
@@ -159,19 +159,20 @@ BUILTIN(FinalizationGroupCleanupSome) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-BUILTIN(FinalizationGroupCleanupIteratorNext) {
+BUILTIN(FinalizationRegistryCleanupIteratorNext) {
   HandleScope scope(isolate);
-  CHECK_RECEIVER(JSFinalizationGroupCleanupIterator, iterator, "next");
+  CHECK_RECEIVER(JSFinalizationRegistryCleanupIterator, iterator, "next");
 
-  Handle<JSFinalizationGroup> finalization_group(iterator->finalization_group(),
-                                                 isolate);
-  if (!finalization_group->NeedsCleanup()) {
+  Handle<JSFinalizationRegistry> finalization_registry(
+      iterator->finalization_registry(), isolate);
+  if (!finalization_registry->NeedsCleanup()) {
     return *isolate->factory()->NewJSIteratorResult(
         handle(ReadOnlyRoots(isolate).undefined_value(), isolate), true);
   }
-  Handle<Object> holdings = handle(
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate),
-      isolate);
+  Handle<Object> holdings =
+      handle(JSFinalizationRegistry::PopClearedCellHoldings(
+                 finalization_registry, isolate),
+             isolate);
 
   return *isolate->factory()->NewJSIteratorResult(holdings, false);
 }
diff --git a/deps/v8/src/builtins/builtins.cc b/deps/v8/src/builtins/builtins.cc
index 955656d669..34f7ddc18a 100644
--- a/deps/v8/src/builtins/builtins.cc
+++ b/deps/v8/src/builtins/builtins.cc
@@ -8,6 +8,7 @@
 #include "src/builtins/builtins-descriptors.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/callable.h"
+#include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/diagnostics/code-tracer.h"
 #include "src/execution/isolate.h"
@@ -319,6 +320,7 @@ class OffHeapTrampolineGenerator {
     {
       FrameScope scope(&masm_, StackFrame::NONE);
       if (type == TrampolineType::kJump) {
+        masm_.CodeEntry();
         masm_.JumpToInstructionStream(off_heap_entry);
       } else {
         masm_.Trap();
diff --git a/deps/v8/src/builtins/cast.tq b/deps/v8/src/builtins/cast.tq
index 7e8d08097f..cb7ff412de 100644
--- a/deps/v8/src/builtins/cast.tq
+++ b/deps/v8/src/builtins/cast.tq
@@ -20,7 +20,6 @@ extern macro IsContext(HeapObject): bool;
 extern macro IsNativeContext(HeapObject): bool;
 extern macro IsJSReceiver(HeapObject): bool;
 extern macro TaggedIsCallable(Object): bool;
-extern macro IsDetachedBuffer(JSArrayBuffer): bool;
 extern macro IsHeapNumber(HeapObject): bool;
 extern macro IsBigInt(HeapObject): bool;
 extern macro IsFixedArray(HeapObject): bool;
@@ -624,8 +623,7 @@ Cast<DebugInfo>(implicit context: Context)(o: HeapObject): DebugInfo
 extern macro IsCoverageInfo(HeapObject): bool;
 Cast<CoverageInfo>(implicit context: Context)(o: HeapObject): CoverageInfo
     labels CastError {
-  // TODO(jgruber): Assign an instance type.
-  if (IsFixedArray(o)) return %RawDownCast<CoverageInfo>(o);
+  if (IsCoverageInfo(o)) return %RawDownCast<CoverageInfo>(o);
   goto CastError;
 }
 
diff --git a/deps/v8/src/builtins/convert.tq b/deps/v8/src/builtins/convert.tq
index fe44fe1287..ee9be1d411 100644
--- a/deps/v8/src/builtins/convert.tq
+++ b/deps/v8/src/builtins/convert.tq
@@ -168,6 +168,12 @@ Convert<intptr, Smi>(s: Smi): intptr {
 Convert<uintptr, PositiveSmi>(ps: PositiveSmi): uintptr {
   return Unsigned(SmiUntag(ps));
 }
+Convert<intptr, TaggedIndex>(ti: TaggedIndex): intptr {
+  return TaggedIndexToIntPtr(ti);
+}
+Convert<TaggedIndex, intptr>(i: intptr): TaggedIndex {
+  return IntPtrToTaggedIndex(i);
+}
 Convert<intptr, uintptr>(ui: uintptr): intptr {
   const i = Signed(ui);
   assert(i >= 0);
diff --git a/deps/v8/src/builtins/ia32/builtins-ia32.cc b/deps/v8/src/builtins/ia32/builtins-ia32.cc
index 739cdfdcdc..5bea93214c 100644
--- a/deps/v8/src/builtins/ia32/builtins-ia32.cc
+++ b/deps/v8/src/builtins/ia32/builtins-ia32.cc
@@ -5,17 +5,18 @@
 #if V8_TARGET_ARCH_IA32
 
 #include "src/api/api-arguments.h"
+#include "src/base/bits-iterator.h"
 #include "src/base/iterator.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
@@ -65,6 +66,24 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void CompareStackLimit(MacroAssembler* masm, Register with,
+                       StackLimitKind kind) {
+  DCHECK(masm->root_array_available());
+  Isolate* isolate = masm->isolate();
+  // Address through the root register. No load is needed.
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
+  DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
+
+  intptr_t offset =
+      TurboAssembler::RootRegisterOffsetForExternalReference(isolate, limit);
+  __ cmp(with, Operand(kRootRegister, offset));
+}
+
 void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
                                  Register scratch, Label* stack_overflow,
                                  bool include_receiver = false) {
@@ -637,7 +656,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ CompareRealStackLimit(esp);
+  CompareStackLimit(masm, esp, StackLimitKind::kRealStackLimit);
   __ j(below, &stack_overflow);
 
   // Pop return address.
@@ -856,22 +875,30 @@ static void MaybeOptimizeCode(MacroAssembler* masm,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register scratch1, Register scratch2,
-                                          Label* if_return) {
+                                          Register scratch3, Label* if_return) {
   Register bytecode_size_table = scratch1;
   Register bytecode = scratch2;
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch3;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+                     bytecode, original_bytecode_offset));
   __ Move(bytecode_size_table,
           Immediate(ExternalReference::bytecode_size_table_address()));
 
   // Load the current bytecode.
-  __ movzx_b(bytecode, Operand(kInterpreterBytecodeArrayRegister,
-                               kInterpreterBytecodeOffsetRegister, times_1, 0));
+  __ movzx_b(bytecode, Operand(bytecode_array, bytecode_offset, times_1, 0));
+  __ Move(original_bytecode_offset, bytecode_offset);
 
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode, extra_wide;
@@ -910,9 +937,24 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ cmp(bytecode,
+         Immediate(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ j(not_equal, &not_jump_loop, Label::kNear);
+  // If this is a wide or extra wide JumpLoop, we need to restore the original
+  // bytecode_offset since we might have increased it to skip the wide /
+  // extra-wide prefix bytecode.
+  __ Move(bytecode_offset, original_bytecode_offset);
+  __ jmp(&end, Label::kNear);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
   __ add(bytecode_offset,
          Operand(bytecode_size_table, bytecode, times_int_size, 0));
+
+  __ bind(&end);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1028,7 +1070,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     __ mov(eax, esp);
     __ sub(eax, frame_size);
-    __ CompareRealStackLimit(eax);
+    CompareStackLimit(masm, eax, StackLimitKind::kRealStackLimit);
     __ j(below, &stack_overflow);
 
     // If ok, push undefined as the initial value for all register file entries.
@@ -1056,8 +1098,15 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ mov(Operand(ebp, ecx, times_system_pointer_size, 0), edx);
   __ bind(&no_incoming_new_target_or_generator_register);
 
-  // Load accumulator and bytecode offset into registers.
-  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  CompareStackLimit(masm, esp, StackLimitKind::kInterruptStackLimit);
+  __ j(below, &stack_check_interrupt);
+  __ bind(&after_stack_check_interrupt);
+
+  // The accumulator is already loaded with undefined.
+
   __ mov(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
 
@@ -1088,16 +1137,45 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
   // Either return, or advance to the next bytecode and dispatch.
   Label do_return;
+  __ Push(eax);
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, ecx,
-                                kInterpreterDispatchTableRegister, &do_return);
+                                kInterpreterDispatchTableRegister, eax,
+                                &do_return);
+  __ Pop(eax);
   __ jmp(&do_dispatch);
 
   __ bind(&do_return);
+  __ Pop(eax);
   // The return value is in eax.
   LeaveInterpreterFrame(masm, edx, ecx);
   __ ret(0);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ mov(Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
+         Immediate(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                                kFunctionEntryBytecodeOffset)));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ mov(kInterpreterBytecodeArrayRegister,
+         Operand(ebp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  // It's ok to clobber kInterpreterBytecodeOffsetRegister since we are setting
+  // it again after continuing.
+  __ SmiTag(kInterpreterBytecodeOffsetRegister);
+  __ mov(Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
+         kInterpreterBytecodeOffsetRegister);
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1408,6 +1486,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
          Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmp(kInterpreterBytecodeOffsetRegister,
+           Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    __ j(greater_equal, &okay, Label::kNear);
+    __ int3();
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   __ movzx_b(scratch, Operand(kInterpreterBytecodeArrayRegister,
                               kInterpreterBytecodeOffsetRegister, times_1, 0));
@@ -1425,12 +1512,21 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
          Operand(ebp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ cmp(kInterpreterBytecodeOffsetRegister,
+         Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                   kFunctionEntryBytecodeOffset));
+  __ j(equal, &function_entry_bytecode);
+
   // Advance to the next bytecode.
   Label if_return;
+  __ Push(eax);
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, ecx, esi,
-                                &if_return);
+                                eax, &if_return);
+  __ Pop(eax);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ mov(ecx, kInterpreterBytecodeOffsetRegister);
   __ SmiTag(ecx);
@@ -1438,8 +1534,18 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ jmp(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
+  // No need to pop eax here since we will be aborting anyway.
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
 }
 
@@ -1524,9 +1630,10 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
-  //  -- esp[4]  : argArray
-  //  -- esp[8]  : thisArg
-  //  -- esp[12] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : thisArg
+  //  -- args[2] : argArray
   // -----------------------------------
 
   // 1. Load receiver into xmm0, argArray into edx (if present), remove all
@@ -1534,20 +1641,19 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // present) instead.
   {
     Label no_arg_array, no_this_arg;
+    StackArgumentsAccessor args(eax);
     // Spill receiver to allow the usage of edi as a scratch register.
-    __ movd(xmm0,
-            Operand(esp, eax, times_system_pointer_size, kSystemPointerSize));
+    __ movd(xmm0, args[0]);
 
     __ LoadRoot(edx, RootIndex::kUndefinedValue);
     __ mov(edi, edx);
     __ test(eax, eax);
     __ j(zero, &no_this_arg, Label::kNear);
     {
-      __ mov(edi, Operand(esp, eax, times_system_pointer_size, 0));
+      __ mov(edi, args[1]);
       __ cmp(eax, Immediate(1));
       __ j(equal, &no_arg_array, Label::kNear);
-      __ mov(edx,
-             Operand(esp, eax, times_system_pointer_size, -kSystemPointerSize));
+      __ mov(edx, args[2]);
       __ bind(&no_arg_array);
     }
     __ bind(&no_this_arg);
@@ -1615,7 +1721,10 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
   }
 
   // 2. Get the callable to call (passed as receiver) from the stack.
-  __ mov(edi, Operand(esp, eax, times_system_pointer_size, kSystemPointerSize));
+  {
+    StackArgumentsAccessor args(eax);
+    __ mov(edi, args.GetReceiverOperand());
+  }
 
   // 3. Shift arguments and return address one slot down on the stack
   //    (overwriting the original receiver).  Adjust argument count to make
@@ -1641,10 +1750,11 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
-  //  -- esp[4]  : argumentsList
-  //  -- esp[8]  : thisArgument
-  //  -- esp[12] : target
-  //  -- esp[16] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : target
+  //  -- args[2] : thisArgument
+  //  -- args[3] : argumentsList
   // -----------------------------------
 
   // 1. Load target into edi (if present), argumentsList into edx (if present),
@@ -1652,20 +1762,18 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   // thisArgument (if present) instead.
   {
     Label done;
+    StackArgumentsAccessor args(eax);
     __ LoadRoot(edi, RootIndex::kUndefinedValue);
     __ mov(edx, edi);
     __ mov(ecx, edi);
     __ cmp(eax, Immediate(1));
     __ j(below, &done, Label::kNear);
-    __ mov(edi, Operand(esp, eax, times_system_pointer_size,
-                        -0 * kSystemPointerSize));
+    __ mov(edi, args[1]);  // target
     __ j(equal, &done, Label::kNear);
-    __ mov(ecx, Operand(esp, eax, times_system_pointer_size,
-                        -1 * kSystemPointerSize));
+    __ mov(ecx, args[2]);  // thisArgument
     __ cmp(eax, Immediate(3));
     __ j(below, &done, Label::kNear);
-    __ mov(edx, Operand(esp, eax, times_system_pointer_size,
-                        -2 * kSystemPointerSize));
+    __ mov(edx, args[3]);  // argumentsList
     __ bind(&done);
 
     // Spill argumentsList to use edx as a scratch register.
@@ -1701,10 +1809,11 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax     : argc
   //  -- esp[0]  : return address
-  //  -- esp[4]  : new.target (optional)
-  //  -- esp[8]  : argumentsList
-  //  -- esp[12] : target
-  //  -- esp[16] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : target
+  //  -- args[2] : argumentsList
+  //  -- args[3] : new.target (optional)
   // -----------------------------------
 
   // 1. Load target into edi (if present), argumentsList into ecx (if present),
@@ -1713,21 +1822,19 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   // (if present) instead.
   {
     Label done;
+    StackArgumentsAccessor args(eax);
     __ LoadRoot(edi, RootIndex::kUndefinedValue);
     __ mov(edx, edi);
     __ mov(ecx, edi);
     __ cmp(eax, Immediate(1));
     __ j(below, &done, Label::kNear);
-    __ mov(edi, Operand(esp, eax, times_system_pointer_size,
-                        -0 * kSystemPointerSize));
+    __ mov(edi, args[1]);  // target
     __ mov(edx, edi);
     __ j(equal, &done, Label::kNear);
-    __ mov(ecx, Operand(esp, eax, times_system_pointer_size,
-                        -1 * kSystemPointerSize));
+    __ mov(ecx, args[2]);  // argumentsList
     __ cmp(eax, Immediate(3));
     __ j(below, &done, Label::kNear);
-    __ mov(edx, Operand(esp, eax, times_system_pointer_size,
-                        -2 * kSystemPointerSize));
+    __ mov(edx, args[3]);  // new.target
     __ bind(&done);
 
     // Spill argumentsList to use ecx as a scratch register.
@@ -1989,6 +2096,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the function to call (checked to be a JSFunction)
   // -----------------------------------
+  StackArgumentsAccessor args(eax);
   __ AssertFunction(edi);
 
   // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
@@ -2022,15 +2130,13 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ LoadGlobalProxy(ecx);
     } else {
       Label convert_to_object, convert_receiver;
-      __ mov(ecx,
-             Operand(esp, eax, times_system_pointer_size, kSystemPointerSize));
+      __ mov(ecx, args.GetReceiverOperand());
       __ JumpIfSmi(ecx, &convert_to_object, Label::kNear);
       STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
       __ CmpObjectType(ecx, FIRST_JS_RECEIVER_TYPE, ecx);  // Clobbers ecx.
       __ j(above_equal, &done_convert);
       // Reload the receiver (it was clobbered by CmpObjectType).
-      __ mov(ecx,
-             Operand(esp, eax, times_system_pointer_size, kSystemPointerSize));
+      __ mov(ecx, args.GetReceiverOperand());
       if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
         Label convert_global_proxy;
         __ JumpIfRoot(ecx, RootIndex::kUndefinedValue, &convert_global_proxy,
@@ -2066,8 +2172,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
       __ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
       __ bind(&convert_receiver);
     }
-    __ mov(Operand(esp, eax, times_system_pointer_size, kSystemPointerSize),
-           ecx);
+    __ mov(args.GetReceiverOperand(), ecx);
   }
   __ bind(&done_convert);
 
@@ -2125,7 +2230,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CompareRealStackLimit(esp);
+      CompareStackLimit(masm, esp, StackLimitKind::kRealStackLimit);
       __ j(above_equal, &done, Label::kNear);
       // Restore the stack pointer.
       __ lea(esp, Operand(esp, edx, times_system_pointer_size, 0));
@@ -2202,8 +2307,9 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
   __ AssertBoundFunction(edi);
 
   // Patch the receiver to [[BoundThis]].
+  StackArgumentsAccessor args(eax);
   __ mov(ecx, FieldOperand(edi, JSBoundFunction::kBoundThisOffset));
-  __ mov(Operand(esp, eax, times_system_pointer_size, kSystemPointerSize), ecx);
+  __ mov(args.GetReceiverOperand(), ecx);
 
   // Push the [[BoundArguments]] onto the stack.
   Generate_PushBoundArguments(masm);
@@ -2220,6 +2326,7 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
   //  -- eax : the number of arguments (not including the receiver)
   //  -- edi : the target to call (can be any Object).
   // -----------------------------------
+  StackArgumentsAccessor args(eax);
 
   Label non_callable, non_function, non_smi, non_jsfunction,
       non_jsboundfunction;
@@ -2251,7 +2358,7 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
   // not we raise an exception).
   __ bind(&non_function);
   // Overwrite the original receiver with the (original) target.
-  __ mov(Operand(esp, eax, times_system_pointer_size, kSystemPointerSize), edi);
+  __ mov(args.GetReceiverOperand(), edi);
   // Let the "call_as_function_delegate" take care of the rest.
   __ LoadNativeContextSlot(edi, Context::CALL_AS_FUNCTION_DELEGATE_INDEX);
   __ Jump(masm->isolate()->builtins()->CallFunction(
@@ -2334,6 +2441,7 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   //           the JSFunction on which new was invoked initially)
   //  -- edi : the constructor to call (can be any Object)
   // -----------------------------------
+  StackArgumentsAccessor args(eax);
 
   // Check if target is a Smi.
   Label non_constructor, non_proxy, non_jsfunction, non_jsboundfunction;
@@ -2370,8 +2478,7 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   __ bind(&non_proxy);
   {
     // Overwrite the original receiver with the (original) target.
-    __ mov(Operand(esp, eax, times_system_pointer_size, kSystemPointerSize),
-           edi);
+    __ mov(args.GetReceiverOperand(), edi);
     // Let the "call_as_constructor_delegate" take care of the rest.
     __ LoadNativeContextSlot(edi, Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX);
     __ Jump(masm->isolate()->builtins()->CallFunction(),
@@ -2396,8 +2503,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   const Register kExpectedNumberOfArgumentsRegister = ecx;
 
   Label invoke, dont_adapt_arguments, stack_overflow, enough, too_few;
-  __ cmp(kExpectedNumberOfArgumentsRegister,
-         SharedFunctionInfo::kDontAdaptArgumentsSentinel);
+  __ cmp(kExpectedNumberOfArgumentsRegister, kDontAdaptArgumentsSentinel);
   __ j(equal, &dont_adapt_arguments);
   __ cmp(eax, kExpectedNumberOfArgumentsRegister);
   __ j(less, &too_few);
@@ -2564,7 +2670,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
       offset += kSimd128Size;
     }
 
-    // Push the WASM instance as an explicit argument to WasmCompileLazy.
+    // Push the Wasm instance as an explicit argument to WasmCompileLazy.
     __ Push(kWasmInstanceRegister);
     // Push the function index as second argument.
     __ Push(kWasmCompileLazyFuncIndexRegister);
@@ -2594,6 +2700,49 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ jmp(edi);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    for (int reg_code : base::bits::IterateBitsBackwards(
+             WasmDebugBreakFrameConstants::kPushedGpRegs)) {
+      __ Push(Register::from_code(reg_code));
+    }
+
+    constexpr int kFpStackSize =
+        kSimd128Size * WasmDebugBreakFrameConstants::kNumPushedFpRegisters;
+    __ AllocateStackSpace(kFpStackSize);
+    int offset = kFpStackSize;
+    for (int reg_code : base::bits::IterateBitsBackwards(
+             WasmDebugBreakFrameConstants::kPushedFpRegs)) {
+      offset -= kSimd128Size;
+      __ movdqu(Operand(esp, offset), DoubleRegister::from_code(reg_code));
+    }
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(kContextRegister, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    for (int reg_code :
+         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedFpRegs)) {
+      __ movdqu(DoubleRegister::from_code(reg_code), Operand(esp, offset));
+      offset += kSimd128Size;
+    }
+    __ add(esp, Immediate(kFpStackSize));
+    for (int reg_code :
+         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedGpRegs)) {
+      __ Pop(Register::from_code(reg_code));
+    }
+  }
+
+  __ ret(0);
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
diff --git a/deps/v8/src/builtins/internal-coverage.tq b/deps/v8/src/builtins/internal-coverage.tq
index ebedbdce75..65cb207eaa 100644
--- a/deps/v8/src/builtins/internal-coverage.tq
+++ b/deps/v8/src/builtins/internal-coverage.tq
@@ -6,46 +6,20 @@
 
 namespace internal_coverage {
 
-  const kHasCoverageInfo:
-      constexpr int31 generates 'DebugInfo::kHasCoverageInfo';
-
-  const kFirstSlotIndex:
-      constexpr int31 generates 'CoverageInfo::kFirstSlotIndex';
-  const kSlotBlockCountIndex:
-      constexpr int31 generates 'CoverageInfo::kSlotBlockCountIndex';
-  const kSlotIndexCountLog2:
-      constexpr int31 generates 'CoverageInfo::kSlotIndexCountLog2';
-  const kSlotIndexCountMask:
-      constexpr int31 generates 'CoverageInfo::kSlotIndexCountMask';
-
   macro GetCoverageInfo(implicit context: Context)(function: JSFunction):
       CoverageInfo labels IfNoCoverageInfo {
     const shared: SharedFunctionInfo = function.shared_function_info;
     const debugInfo = Cast<DebugInfo>(shared.script_or_debug_info)
         otherwise goto IfNoCoverageInfo;
 
-    if ((debugInfo.flags & kHasCoverageInfo) == 0) goto IfNoCoverageInfo;
+    if (!SmiUntag(debugInfo.flags).has_coverage_info) goto IfNoCoverageInfo;
     return UnsafeCast<CoverageInfo>(debugInfo.coverage_info);
   }
 
-  macro SlotCount(coverageInfo: CoverageInfo): Smi {
-    assert(kFirstSlotIndex == 0);  // Otherwise we'd have to consider it below.
-    assert(kFirstSlotIndex == (coverageInfo.length & kSlotIndexCountMask));
-    return coverageInfo.length >> kSlotIndexCountLog2;
-  }
-
-  macro FirstIndexForSlot(implicit context: Context)(slot: Smi): Smi {
-    assert(kFirstSlotIndex == 0);  // Otherwise we'd have to consider it below.
-    return slot << kSlotIndexCountLog2;
-  }
-
   macro IncrementBlockCount(implicit context: Context)(
       coverageInfo: CoverageInfo, slot: Smi) {
-    assert(slot < SlotCount(coverageInfo));
-    const slotStart: Smi = FirstIndexForSlot(slot);
-    const index: Smi = slotStart + kSlotBlockCountIndex;
-    coverageInfo.objects[index] =
-        UnsafeCast<Smi>(coverageInfo.objects[index]) + 1;
+    assert(Convert<int32>(slot) < coverageInfo.slot_count);
+    ++coverageInfo.slots[slot].block_count;
   }
 
   builtin IncBlockCounter(implicit context: Context)(
diff --git a/deps/v8/src/builtins/iterator.tq b/deps/v8/src/builtins/iterator.tq
index 51a9564850..272a2a7db8 100644
--- a/deps/v8/src/builtins/iterator.tq
+++ b/deps/v8/src/builtins/iterator.tq
@@ -52,8 +52,8 @@ namespace iterator {
                                                     Context)(JSAny);
 
   transitioning builtin GetIteratorWithFeedback(
-      context: Context, receiver: JSAny, loadSlot: Smi, callSlot: Smi,
-      feedback: Undefined|FeedbackVector): JSAny {
+      context: Context, receiver: JSAny, loadSlot: TaggedIndex,
+      callSlot: TaggedIndex, feedback: Undefined|FeedbackVector): JSAny {
     let iteratorMethod: JSAny;
     typeswitch (feedback) {
       case (Undefined): {
@@ -64,8 +64,10 @@ namespace iterator {
             context, receiver, IteratorSymbolConstant(), loadSlot, feedback);
       }
     }
+    // TODO(v8:10047): Use TaggedIndex here once TurboFan supports it.
+    const callSlotSmi: Smi = TaggedIndexToSmi(callSlot);
     return CallIteratorWithFeedback(
-        context, receiver, iteratorMethod, callSlot, feedback);
+        context, receiver, iteratorMethod, callSlotSmi, feedback);
   }
 
   transitioning builtin CallIteratorWithFeedback(
diff --git a/deps/v8/src/builtins/mips/builtins-mips.cc b/deps/v8/src/builtins/mips/builtins-mips.cc
index 2561177cd6..cb1a86db2f 100644
--- a/deps/v8/src/builtins/mips/builtins-mips.cc
+++ b/deps/v8/src/builtins/mips/builtins-mips.cc
@@ -23,6 +23,7 @@
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -61,10 +62,16 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void LoadStackLimit(MacroAssembler* masm, Register destination,
+                    StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -143,7 +150,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  LoadRealStackLimit(masm, scratch1);
+  LoadStackLimit(masm, scratch1, StackLimitKind::kRealStackLimit);
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ subu(scratch1, sp, scratch1);
@@ -354,7 +361,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  LoadRealStackLimit(masm, scratch1);
+  LoadStackLimit(masm, scratch1, StackLimitKind::kRealStackLimit);
   // Make a2 the space we have left. The stack might already be overflowed
   // here which will cause a2 to become negative.
   __ Subu(scratch1, sp, scratch1);
@@ -701,7 +708,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  LoadRealStackLimit(masm, kScratchReg);
+  LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
   __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
 
   // Push receiver.
@@ -1058,7 +1065,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
     // Do a stack check to ensure we don't go over the limit.
     __ Subu(t1, sp, Operand(t0));
-    LoadRealStackLimit(masm, a2);
+    LoadStackLimit(masm, a2, StackLimitKind::kRealStackLimit);
     __ Branch(&stack_overflow, lo, t1, Operand(a2));
 
     // If ok, push undefined as the initial value for all register file entries.
@@ -1087,6 +1094,13 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ sw(a3, MemOperand(t1));
   __ bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  LoadStackLimit(masm, a2, StackLimitKind::kInterruptStackLimit);
+  __ Branch(&stack_check_interrupt, lo, sp, Operand(a2));
+  __ bind(&after_stack_check_interrupt);
+
   // Load accumulator with undefined.
   __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
@@ -1128,6 +1142,30 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, t0);
   __ Jump(ra);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                             kFunctionEntryBytecodeOffset)));
+  __ Sw(kInterpreterBytecodeOffsetRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ Lw(kInterpreterBytecodeArrayRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
+  __ Sw(a2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1332,6 +1370,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ Branch(&okay, ge, kInterpreterBytecodeOffsetRegister,
+              Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    // Unreachable code.
+    __ break_(0xCC);
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   __ Addu(a1, kInterpreterBytecodeArrayRegister,
           kInterpreterBytecodeOffsetRegister);
@@ -1351,6 +1398,11 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ Branch(&function_entry_bytecode, eq, kInterpreterBytecodeOffsetRegister,
+            Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                    kFunctionEntryBytecodeOffset));
+
   // Load the current bytecode.
   __ Addu(a1, kInterpreterBytecodeArrayRegister,
           kInterpreterBytecodeOffsetRegister);
@@ -1362,12 +1414,22 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
                                 kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
   __ sw(a2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ Branch(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -1982,7 +2044,7 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
     __ Subu(sp, sp, Operand(t1));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    LoadRealStackLimit(masm, kScratchReg);
+    LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
     __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Addu(sp, sp, Operand(t1));
@@ -2139,7 +2201,7 @@ void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
     __ Subu(sp, sp, Operand(t1));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    LoadRealStackLimit(masm, kScratchReg);
+    LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
     __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Addu(sp, sp, Operand(t1));
@@ -2264,7 +2326,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 
   Label enough, too_few;
   __ Branch(&dont_adapt_arguments, eq, a2,
-            Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+            Operand(kDontAdaptArgumentsSentinel));
   // We use Uless as the number of argument should always be greater than 0.
   __ Branch(&too_few, Uless, a0, Operand(a2));
 
@@ -2397,7 +2459,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     // Save all parameter registers (see wasm-linkage.cc). They might be
     // overwritten in the runtime call below. We don't have any callee-saved
     // registers in wasm, so no need to store anything else.
-    constexpr RegList gp_regs = Register::ListOf(a0, a1, a2, a3);
+    constexpr RegList gp_regs = Register::ListOf(a0, a2, a3);
     constexpr RegList fp_regs =
         DoubleRegister::ListOf(f2, f4, f6, f8, f10, f12, f14);
     __ MultiPush(gp_regs);
@@ -2419,6 +2481,28 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(kScratchReg, v0, 0);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    __ MultiPush(WasmDebugBreakFrameConstants::kPushedGpRegs);
+    __ MultiPushFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ MultiPopFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
+    __ MultiPop(WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
diff --git a/deps/v8/src/builtins/mips64/builtins-mips64.cc b/deps/v8/src/builtins/mips64/builtins-mips64.cc
index 8e91f8840f..baf2d5bfec 100644
--- a/deps/v8/src/builtins/mips64/builtins-mips64.cc
+++ b/deps/v8/src/builtins/mips64/builtins-mips64.cc
@@ -23,6 +23,7 @@
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -60,10 +61,16 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void LoadStackLimit(MacroAssembler* masm, Register destination,
+                    StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -144,7 +151,7 @@ static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  LoadRealStackLimit(masm, scratch1);
+  LoadStackLimit(masm, scratch1, StackLimitKind::kRealStackLimit);
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ dsubu(scratch1, sp, scratch1);
@@ -394,7 +401,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  LoadRealStackLimit(masm, kScratchReg);
+  LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
   __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
 
   // Push receiver.
@@ -501,7 +508,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  LoadRealStackLimit(masm, scratch1);
+  LoadStackLimit(masm, scratch1, StackLimitKind::kRealStackLimit);
   // Make a2 the space we have left. The stack might already be overflowed
   // here which will cause r2 to become negative.
   __ dsubu(scratch1, sp, scratch1);
@@ -1076,7 +1083,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
     // Do a stack check to ensure we don't go over the limit.
     __ Dsubu(a5, sp, Operand(a4));
-    LoadRealStackLimit(masm, a2);
+    LoadStackLimit(masm, a2, StackLimitKind::kRealStackLimit);
     __ Branch(&stack_overflow, lo, a5, Operand(a2));
 
     // If ok, push undefined as the initial value for all register file entries.
@@ -1105,6 +1112,13 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ Sd(a3, MemOperand(a5));
   __ bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  LoadStackLimit(masm, a5, StackLimitKind::kInterruptStackLimit);
+  __ Branch(&stack_check_interrupt, lo, sp, Operand(a5));
+  __ bind(&after_stack_check_interrupt);
+
   // Load accumulator as undefined.
   __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
 
@@ -1147,6 +1161,30 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, t0);
   __ Jump(ra);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                             kFunctionEntryBytecodeOffset)));
+  __ Sd(kInterpreterBytecodeOffsetRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ Ld(kInterpreterBytecodeArrayRegister,
+        MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(a5, kInterpreterBytecodeOffsetRegister);
+  __ Sd(a5, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1350,6 +1388,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister,
               MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ Branch(&okay, ge, kInterpreterBytecodeOffsetRegister,
+              Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    // Unreachable code.
+    __ break_(0xCC);
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   __ Daddu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
@@ -1369,6 +1416,11 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
         MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ Branch(&function_entry_bytecode, eq, kInterpreterBytecodeOffsetRegister,
+            Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                    kFunctionEntryBytecodeOffset));
+
   // Load the current bytecode.
   __ Daddu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
@@ -1380,12 +1432,22 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
                                 kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
   __ Sd(a2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ li(kInterpreterBytecodeOffsetRegister,
+        Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ Branch(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -2023,7 +2085,7 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
     __ Dsubu(sp, sp, Operand(a5));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    LoadRealStackLimit(masm, kScratchReg);
+    LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
     __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Daddu(sp, sp, Operand(a5));
@@ -2176,7 +2238,7 @@ void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
     __ Dsubu(sp, sp, Operand(a5));
     // Check the stack for overflow. We are not trying to catch interruptions
     // (i.e. debug break and preemption) here, so check the "real stack limit".
-    LoadRealStackLimit(masm, kScratchReg);
+    LoadStackLimit(masm, kScratchReg, StackLimitKind::kRealStackLimit);
     __ Branch(&done, hs, sp, Operand(kScratchReg));
     // Restore the stack pointer.
     __ Daddu(sp, sp, Operand(a5));
@@ -2300,7 +2362,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
 
   Label enough, too_few;
   __ Branch(&dont_adapt_arguments, eq, a2,
-            Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+            Operand(kDontAdaptArgumentsSentinel));
   // We use Uless as the number of argument should always be greater than 0.
   __ Branch(&too_few, Uless, a0, Operand(a2));
 
@@ -2436,7 +2498,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
     // overwritten in the runtime call below. We don't have any callee-saved
     // registers in wasm, so no need to store anything else.
     constexpr RegList gp_regs =
-        Register::ListOf(a0, a1, a2, a3, a4, a5, a6, a7);
+        Register::ListOf(a0, a2, a3, a4, a5, a6, a7);
     constexpr RegList fp_regs =
         DoubleRegister::ListOf(f2, f4, f6, f8, f10, f12, f14);
     __ MultiPush(gp_regs);
@@ -2458,6 +2520,28 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(v0);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    __ MultiPush(WasmDebugBreakFrameConstants::kPushedGpRegs);
+    __ MultiPushFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ MultiPopFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
+    __ MultiPop(WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
diff --git a/deps/v8/src/builtins/number.tq b/deps/v8/src/builtins/number.tq
index 37d51812a9..958cd5f5f6 100644
--- a/deps/v8/src/builtins/number.tq
+++ b/deps/v8/src/builtins/number.tq
@@ -34,7 +34,7 @@ namespace number {
     // 4. Else, let radixNumber be ? ToInteger(radix).
     const radix: JSAny = arguments[0];
     const radixNumber: Number =
-        radix == Undefined ? 10 : ToInteger_Inline(radix, kTruncateMinusZero);
+        radix == Undefined ? 10 : ToInteger_Inline(radix);
 
     // 5. If radixNumber < 2 or radixNumber > 36, throw a RangeError exception.
     if (radixNumber < 2 || radixNumber > 36) {
diff --git a/deps/v8/src/builtins/ppc/builtins-ppc.cc b/deps/v8/src/builtins/ppc/builtins-ppc.cc
index 97e870959a..460d749297 100644
--- a/deps/v8/src/builtins/ppc/builtins-ppc.cc
+++ b/deps/v8/src/builtins/ppc/builtins-ppc.cc
@@ -2,25 +2,26 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
 #include "src/objects/js-generator.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -58,10 +59,16 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+void LoadStackLimit(MacroAssembler* masm, Register destination,
+                    StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -75,7 +82,7 @@ void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  LoadRealStackLimit(masm, scratch);
+  LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ sub(scratch, sp, scratch);
@@ -424,7 +431,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  LoadRealStackLimit(masm, scratch);
+  LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
   __ cmpl(sp, scratch);
   __ blt(&stack_overflow);
 
@@ -717,7 +724,7 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  LoadRealStackLimit(masm, scratch1);
+  LoadStackLimit(masm, scratch1, StackLimitKind::kRealStackLimit);
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ sub(scratch1, sp, scratch1);
@@ -950,18 +957,27 @@ static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register bytecode, Register scratch1,
-                                          Label* if_return) {
+                                          Register scratch2, Label* if_return) {
   Register bytecode_size_table = scratch1;
-  Register scratch2 = bytecode;
+  Register scratch3 = bytecode;
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch2;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+                     bytecode, original_bytecode_offset));
   __ Move(bytecode_size_table,
           ExternalReference::bytecode_size_table_address());
+  __ Move(original_bytecode_offset, bytecode_offset);
 
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode, extra_wide;
@@ -992,7 +1008,7 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   // Load the size of the current bytecode.
   __ bind(&process_bytecode);
 
-// Bailout to the return label if this is a return bytecode.
+  // Bailout to the return label if this is a return bytecode.
 #define JUMP_IF_EQUAL(NAME)                                           \
   __ cmpi(bytecode,                                                   \
           Operand(static_cast<int>(interpreter::Bytecode::k##NAME))); \
@@ -1000,10 +1016,24 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ cmpi(bytecode,
+          Operand(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ bne(&not_jump_loop);
+  // We need to restore the original bytecode_offset since we might have
+  // increased it to skip the wide / extra-wide prefix bytecode.
+  __ Move(bytecode_offset, original_bytecode_offset);
+  __ b(&end);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
-  __ ShiftLeftImm(scratch2, bytecode, Operand(2));
-  __ lwzx(scratch2, MemOperand(bytecode_size_table, scratch2));
-  __ add(bytecode_offset, bytecode_offset, scratch2);
+  __ ShiftLeftImm(scratch3, bytecode, Operand(2));
+  __ lwzx(scratch3, MemOperand(bytecode_size_table, scratch3));
+  __ add(bytecode_offset, bytecode_offset, scratch3);
+
+  __ bind(&end);
 }
 // Generate code for entering a JS function with the interpreter.
 // On entry to the function the receiver and arguments have been pushed on the
@@ -1118,7 +1148,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
     // Do a stack check to ensure we don't go over the limit.
     __ sub(r8, sp, r5);
-    LoadRealStackLimit(masm, r0);
+    LoadStackLimit(masm, r0, StackLimitKind::kRealStackLimit);
     __ cmpl(r8, r0);
     __ blt(&stack_overflow);
 
@@ -1148,6 +1178,14 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ StorePX(r6, MemOperand(fp, r8));
   __ bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  LoadStackLimit(masm, r6, StackLimitKind::kInterruptStackLimit);
+  __ cmpl(sp, r6);
+  __ blt(&stack_check_interrupt);
+  __ bind(&after_stack_check_interrupt);
+
   // The accumulator is already loaded with undefined.
 
   // Load the dispatch table into a register and dispatch to the bytecode
@@ -1181,7 +1219,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ lbzx(r4, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r4, r5,
+                                kInterpreterBytecodeOffsetRegister, r4, r5, r6,
                                 &do_return);
   __ b(&do_dispatch);
 
@@ -1190,6 +1228,31 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, r5);
   __ blr();
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                              kFunctionEntryBytecodeOffset)));
+  __ StoreP(kInterpreterBytecodeOffsetRegister,
+            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ LoadP(kInterpreterBytecodeArrayRegister,
+           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(r6, kInterpreterBytecodeOffsetRegister);
+  __ StoreP(r6,
+            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&optimized_code_slot_not_empty);
   Label maybe_has_optimized_code;
   // Check if optimized code marker is actually a weak reference to the
@@ -1394,6 +1457,16 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmpi(kInterpreterBytecodeOffsetRegister,
+            Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                    kFunctionEntryBytecodeOffset));
+    __ bge(&okay);
+    __ bkpt(0);
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   UseScratchRegisterScope temps(masm);
   Register scratch = temps.Acquire();
@@ -1413,6 +1486,12 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ cmpi(kInterpreterBytecodeOffsetRegister,
+          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                  kFunctionEntryBytecodeOffset));
+  __ beq(&function_entry_bytecode);
+
   // Load the current bytecode.
   __ lbzx(r4, MemOperand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister));
@@ -1420,9 +1499,10 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   // Advance to the next bytecode.
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r4, r5,
+                                kInterpreterBytecodeOffsetRegister, r4, r5, r6,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(r5, kInterpreterBytecodeOffsetRegister);
   __ StoreP(r5,
@@ -1430,6 +1510,15 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ b(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -2083,7 +2172,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       {
         UseScratchRegisterScope temps(masm);
         Register scratch = temps.Acquire();
-        LoadRealStackLimit(masm, scratch);
+        LoadStackLimit(masm, scratch, StackLimitKind::kRealStackLimit);
         __ cmpl(sp, scratch);
       }
       __ bgt(&done);  // Signed comparison.
@@ -2325,7 +2414,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // -----------------------------------
 
   Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
-  __ cmpli(r5, Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+  __ cmpli(r5, Operand(kDontAdaptArgumentsSentinel));
   __ beq(&dont_adapt_arguments);
   __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
   __ lwz(r7, FieldMemOperand(r7, SharedFunctionInfo::kFlagsOffset));
@@ -2532,6 +2621,28 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(r11);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    __ MultiPush(WasmDebugBreakFrameConstants::kPushedGpRegs);
+    __ MultiPushDoubles(WasmDebugBreakFrameConstants::kPushedFpRegs);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ LoadSmiLiteral(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ MultiPopDoubles(WasmDebugBreakFrameConstants::kPushedFpRegs);
+    __ MultiPop(WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
@@ -3192,4 +3303,4 @@ void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/builtins/promise-abstract-operations.tq b/deps/v8/src/builtins/promise-abstract-operations.tq
index 8828ab84d2..95ca356a0c 100644
--- a/deps/v8/src/builtins/promise-abstract-operations.tq
+++ b/deps/v8/src/builtins/promise-abstract-operations.tq
@@ -40,7 +40,8 @@ namespace promise {
   EnqueueMicrotask(Context, Microtask): Undefined;
 
   macro
-  ExtractHandlerContext(implicit context: Context)(handler: Callable|Undefined):
+  ExtractHandlerContextInternal(implicit context: Context)(handler: Callable|
+                                                           Undefined):
       Context labels NotFound {
     let iter: JSAny = handler;
     while (true) {
@@ -62,16 +63,25 @@ namespace promise {
     goto NotFound;
   }
 
-  // According to the HTML specification, we use the handler's context to
-  // EnqueueJob for Promise resolution.
+  macro
+  ExtractHandlerContext(implicit context: Context)(handler: Callable|
+                                                   Undefined): Context {
+    try {
+      return ExtractHandlerContextInternal(handler) otherwise NotFound;
+    }
+    label NotFound deferred {
+      return context;
+    }
+  }
+
   macro
   ExtractHandlerContext(implicit context: Context)(
       primary: Callable|Undefined, secondary: Callable|Undefined): Context {
     try {
-      return ExtractHandlerContext(primary) otherwise NotFound;
+      return ExtractHandlerContextInternal(primary) otherwise NotFound;
     }
     label NotFound deferred {
-      return ExtractHandlerContext(secondary) otherwise Default;
+      return ExtractHandlerContextInternal(secondary) otherwise Default;
     }
     label Default deferred {
       return context;
@@ -92,6 +102,9 @@ namespace promise {
       secondaryHandler = promiseReaction.fulfill_handler;
     }
 
+    // According to HTML, we use the context of the appropriate handler as the
+    // context of the microtask. See step 3 of HTML's EnqueueJob:
+    // https://html.spec.whatwg.org/C/#enqueuejob(queuename,-job,-arguments)
     const handlerContext: Context =
         ExtractHandlerContext(primaryHandler, secondaryHandler);
 
@@ -102,7 +115,8 @@ namespace promise {
         kPromiseReactionSize ==
         kPromiseReactionJobTaskSizeOfAllPromiseReactionJobTasks);
     if constexpr (reactionType == kPromiseReactionFulfill) {
-      promiseReaction.map = PromiseFulfillReactionJobTaskMapConstant();
+      * UnsafeConstCast(& promiseReaction.map) =
+          PromiseFulfillReactionJobTaskMapConstant();
       const promiseReactionJobTask =
           UnsafeCast<PromiseFulfillReactionJobTask>(promiseReaction);
       promiseReactionJobTask.argument = argument;
@@ -116,7 +130,8 @@ namespace promise {
           kPromiseReactionJobTaskPromiseOrCapabilityOffset);
     } else {
       StaticAssert(reactionType == kPromiseReactionReject);
-      promiseReaction.map = PromiseRejectReactionJobTaskMapConstant();
+      * UnsafeConstCast(& promiseReaction.map) =
+          PromiseRejectReactionJobTaskMapConstant();
       const promiseReactionJobTask =
           UnsafeCast<PromiseRejectReactionJobTask>(promiseReaction);
       promiseReactionJobTask.argument = argument;
@@ -416,34 +431,33 @@ namespace promise {
       // PromiseReaction holding both the onFulfilled and onRejected callbacks.
       // Once the {promise} is resolved we decide on the concrete handler to
       // push onto the microtask queue.
+      const handlerContext = ExtractHandlerContext(onFulfilled, onRejected);
       const promiseReactions =
           UnsafeCast<(Zero | PromiseReaction)>(promise.reactions_or_result);
       const reaction = NewPromiseReaction(
-          promiseReactions, resultPromiseOrCapability, onFulfilled, onRejected);
+          handlerContext, promiseReactions, resultPromiseOrCapability,
+          onFulfilled, onRejected);
       promise.reactions_or_result = reaction;
     } else {
-      let map: Map;
-      let handler: Callable|Undefined = Undefined;
+      const reactionsOrResult = promise.reactions_or_result;
+      let microtask: PromiseReactionJobTask;
       let handlerContext: Context;
       if (promise.Status() == PromiseState::kFulfilled) {
-        map = PromiseFulfillReactionJobTaskMapConstant();
-        handler = onFulfilled;
         handlerContext = ExtractHandlerContext(onFulfilled, onRejected);
+        microtask = NewPromiseFulfillReactionJobTask(
+            handlerContext, reactionsOrResult, onFulfilled,
+            resultPromiseOrCapability);
       } else
         deferred {
           assert(promise.Status() == PromiseState::kRejected);
-          map = PromiseRejectReactionJobTaskMapConstant();
-          handler = onRejected;
           handlerContext = ExtractHandlerContext(onRejected, onFulfilled);
+          microtask = NewPromiseRejectReactionJobTask(
+              handlerContext, reactionsOrResult, onRejected,
+              resultPromiseOrCapability);
           if (!promise.HasHandler()) {
             runtime::PromiseRevokeReject(promise);
           }
         }
-
-      const reactionsOrResult = promise.reactions_or_result;
-      const microtask = NewPromiseReactionJobTask(
-          map, handlerContext, reactionsOrResult, handler,
-          resultPromiseOrCapability);
       EnqueueMicrotask(handlerContext, microtask);
     }
     promise.SetHasHandler();
diff --git a/deps/v8/src/builtins/promise-misc.tq b/deps/v8/src/builtins/promise-misc.tq
index 7996cc5b3d..61461de29f 100644
--- a/deps/v8/src/builtins/promise-misc.tq
+++ b/deps/v8/src/builtins/promise-misc.tq
@@ -16,10 +16,6 @@ namespace promise_internal {
       void;
 
   extern macro PromiseBuiltinsAssembler::AllocateJSPromise(Context): HeapObject;
-
-  extern macro PromiseBuiltinsAssembler::AllocatePromiseReactionJobTask(
-      Context): HeapObject;
-
 }
 
 namespace promise {
@@ -45,7 +41,7 @@ namespace promise {
     assert(IsFunctionWithPrototypeSlotMap(promiseFun.map));
     const promiseMap = UnsafeCast<Map>(promiseFun.prototype_or_initial_map);
     const promiseHeapObject = promise_internal::AllocateJSPromise(context);
-    promiseHeapObject.map = promiseMap;
+    * UnsafeConstCast(& promiseHeapObject.map) = promiseMap;
     const promise = UnsafeCast<JSPromise>(promiseHeapObject);
     promise.properties_or_hash = kEmptyFixedArray;
     promise.elements = kEmptyFixedArray;
@@ -54,20 +50,36 @@ namespace promise {
     return promise;
   }
 
-  macro NewPromiseReactionJobTask(implicit context: Context)(
-      map: Map, handlerContext: Context, argument: Object,
-      handler: Callable|Undefined,
+  macro NewPromiseFulfillReactionJobTask(implicit context: Context)(
+      handlerContext: Context, argument: Object, handler: Callable|Undefined,
       promiseOrCapability: JSPromise|PromiseCapability|
-      Undefined): PromiseReactionJobTask {
-    const taskHeapObject =
-        promise_internal::AllocatePromiseReactionJobTask(context);
-    taskHeapObject.map = map;
-    const jobTask = UnsafeCast<PromiseReactionJobTask>(taskHeapObject);
-    jobTask.argument = argument;
-    jobTask.context = handlerContext;
-    jobTask.handler = handler;
-    jobTask.promise_or_capability = promiseOrCapability;
-    return jobTask;
+      Undefined): PromiseFulfillReactionJobTask {
+    const nativeContext = LoadNativeContext(handlerContext);
+    return new PromiseFulfillReactionJobTask{
+      map: PromiseFulfillReactionJobTaskMapConstant(),
+      argument,
+      context: handlerContext,
+      handler,
+      promise_or_capability: promiseOrCapability,
+      continuation_preserved_embedder_data: nativeContext
+          [NativeContextSlot::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX]
+    };
+  }
+
+  macro NewPromiseRejectReactionJobTask(implicit context: Context)(
+      handlerContext: Context, argument: Object, handler: Callable|Undefined,
+      promiseOrCapability: JSPromise|PromiseCapability|
+      Undefined): PromiseRejectReactionJobTask {
+    const nativeContext = LoadNativeContext(handlerContext);
+    return new PromiseRejectReactionJobTask{
+      map: PromiseRejectReactionJobTaskMapConstant(),
+      argument,
+      context: handlerContext,
+      handler,
+      promise_or_capability: promiseOrCapability,
+      continuation_preserved_embedder_data: nativeContext
+          [NativeContextSlot::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX]
+    };
   }
 
   // These allocate and initialize a promise with pending state and
@@ -113,16 +125,19 @@ namespace promise {
   }
 
   macro NewPromiseReaction(implicit context: Context)(
-      next: Zero|PromiseReaction,
+      handlerContext: Context, next: Zero|PromiseReaction,
       promiseOrCapability: JSPromise|PromiseCapability|Undefined,
       fulfillHandler: Callable|Undefined,
       rejectHandler: Callable|Undefined): PromiseReaction {
+    const nativeContext = LoadNativeContext(handlerContext);
     return new PromiseReaction{
       map: PromiseReactionMapConstant(),
       next: next,
       reject_handler: rejectHandler,
       fulfill_handler: fulfillHandler,
-      promise_or_capability: promiseOrCapability
+      promise_or_capability: promiseOrCapability,
+      continuation_preserved_embedder_data: nativeContext
+          [NativeContextSlot::CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX]
     };
   }
 
@@ -130,10 +145,10 @@ namespace promise {
 
   macro NewPromiseResolveThenableJobTask(implicit context: Context)(
       promiseToResolve: JSPromise, then: JSReceiver, thenable: JSReceiver,
-      thenableContext: Context): PromiseResolveThenableJobTask {
+      thenContext: Context): PromiseResolveThenableJobTask {
     return new PromiseResolveThenableJobTask{
       map: PromiseResolveThenableJobTaskMapConstant(),
-      context: thenableContext,
+      context: thenContext,
       promise_to_resolve: promiseToResolve,
       then: then,
       thenable: thenable
diff --git a/deps/v8/src/builtins/promise-reaction-job.tq b/deps/v8/src/builtins/promise-reaction-job.tq
index 1db33f4a7a..1d20d22efb 100644
--- a/deps/v8/src/builtins/promise-reaction-job.tq
+++ b/deps/v8/src/builtins/promise-reaction-job.tq
@@ -17,27 +17,28 @@ namespace promise {
       promiseOrCapability: JSPromise|PromiseCapability|Undefined, reason: JSAny,
       reactionType: constexpr PromiseReactionType): JSAny {
     if constexpr (reactionType == kPromiseReactionReject) {
-      if (IsJSPromise(promiseOrCapability)) {
-        // For fast native promises we can skip the indirection via the
-        // promiseCapability.[[Reject]] function and run the resolve logic
-        // directly from here.
-        return RejectPromise(
-            UnsafeCast<JSPromise>(promiseOrCapability), reason, False);
-      } else
-        deferred {
-          assert(IsPromiseCapability(promiseOrCapability));
+      typeswitch (promiseOrCapability) {
+        case (promise: JSPromise): {
+          // For fast native promises we can skip the indirection via the
+          // promiseCapability.[[Reject]] function and run the resolve logic
+          // directly from here.
+          return RejectPromise(promise, reason, False);
+        }
+        case (Undefined): {
+          return Undefined;
+        }
+        case (capability: PromiseCapability): {
           // In the general case we need to call the (user provided)
           // promiseCapability.[[Reject]] function.
           try {
-            const promiseCapability =
-                UnsafeCast<PromiseCapability>(promiseOrCapability);
-            const reject = UnsafeCast<Callable>(promiseCapability.reject);
+            const reject = UnsafeCast<Callable>(capability.reject);
             return Call(context, reject, Undefined, reason);
           } catch (e) {
             // Swallow the exception here.
             return runtime::ReportMessage(e);
           }
         }
+      }
     } else {
       StaticAssert(reactionType == kPromiseReactionFulfill);
       // We have to call out to the dedicated PromiseRejectReactionJob
@@ -53,20 +54,20 @@ namespace promise {
       context: Context,
       promiseOrCapability: JSPromise|PromiseCapability|Undefined, result: JSAny,
       reactionType: constexpr PromiseReactionType): JSAny {
-    if (IsJSPromise(promiseOrCapability)) {
-      // For fast native promises we can skip the indirection via the
-      // promiseCapability.[[Resolve]] function and run the resolve logic
-      // directly from here.
-      return ResolvePromise(
-          context, UnsafeCast<JSPromise>(promiseOrCapability), result);
-    } else
-      deferred {
-        assert(IsPromiseCapability(promiseOrCapability));
+    typeswitch (promiseOrCapability) {
+      case (promise: JSPromise): {
+        // For fast native promises we can skip the indirection via the
+        // promiseCapability.[[Resolve]] function and run the resolve logic
+        // directly from here.
+        return ResolvePromise(context, promise, result);
+      }
+      case (Undefined): {
+        return Undefined;
+      }
+      case (capability: PromiseCapability): {
         // In the general case we need to call the (user provided)
         // promiseCapability.[[Resolve]] function.
-        const promiseCapability =
-            UnsafeCast<PromiseCapability>(promiseOrCapability);
-        const resolve = UnsafeCast<Callable>(promiseCapability.resolve);
+        const resolve = UnsafeCast<Callable>(capability.resolve);
         try {
           return Call(context, resolve, Undefined, result);
         } catch (e) {
@@ -74,6 +75,7 @@ namespace promise {
               context, promiseOrCapability, e, reactionType);
         }
       }
+    }
   }
 
   // https://tc39.es/ecma262/#sec-promisereactionjob
diff --git a/deps/v8/src/builtins/promise-resolve.tq b/deps/v8/src/builtins/promise-resolve.tq
index af7dd7afa0..0fc98b556b 100644
--- a/deps/v8/src/builtins/promise-resolve.tq
+++ b/deps/v8/src/builtins/promise-resolve.tq
@@ -177,7 +177,14 @@ namespace promise {
     label Enqueue {
       // 12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob,
       //                        «promise, resolution, thenAction»).
-      const nativeContext = LoadNativeContext(context);
+
+      // According to HTML, we use the context of the then function
+      // (|thenAction|) as the context of the microtask. See step 3 of HTML's
+      // EnqueueJob:
+      // https://html.spec.whatwg.org/C/#enqueuejob(queuename,-job,-arguments)
+      const thenContext: Context =
+          ExtractHandlerContext(UnsafeCast<Callable>(then));
+      const nativeContext = LoadNativeContext(thenContext);
       const task = NewPromiseResolveThenableJobTask(
           promise, UnsafeCast<JSReceiver>(then),
           UnsafeCast<JSReceiver>(resolution), nativeContext);
diff --git a/deps/v8/src/builtins/s390/builtins-s390.cc b/deps/v8/src/builtins/s390/builtins-s390.cc
index b9e56659f7..88bb80891e 100644
--- a/deps/v8/src/builtins/s390/builtins-s390.cc
+++ b/deps/v8/src/builtins/s390/builtins-s390.cc
@@ -6,21 +6,22 @@
 
 #include "src/api/api-arguments.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/foreign.h"
 #include "src/objects/heap-number.h"
 #include "src/objects/js-generator.h"
 #include "src/objects/smi.h"
 #include "src/runtime/runtime.h"
+#include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -58,10 +59,15 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-MemOperand RealStackLimitAsMemOperand(MacroAssembler* masm) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+MemOperand StackLimitAsMemOperand(MacroAssembler* masm, StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -75,7 +81,8 @@ void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ LoadP(scratch, RealStackLimitAsMemOperand(masm));
+  __ LoadP(scratch,
+           StackLimitAsMemOperand(masm, StackLimitKind::kRealStackLimit));
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
   __ SubP(scratch, sp, scratch);
@@ -196,7 +203,8 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     //  --        sp[4*kSystemPointerSize]: context
     // -----------------------------------
 
-    __ LoadP(r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+    __ LoadTaggedPointerField(
+        r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
     __ LoadlW(r6, FieldMemOperand(r6, SharedFunctionInfo::kFlagsOffset));
     __ DecodeField<SharedFunctionInfo::FunctionKindBits>(r6);
     __ JumpIfIsInRange(r6, kDefaultDerivedConstructor, kDerivedConstructor,
@@ -366,8 +374,9 @@ static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
 
   __ CompareObjectType(sfi_data, scratch1, scratch1, INTERPRETER_DATA_TYPE);
   __ bne(&done, Label::kNear);
-  __ LoadP(sfi_data,
-           FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));
+  __ LoadTaggedPointerField(
+      sfi_data,
+      FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));
   __ bind(&done);
 }
 
@@ -381,14 +390,16 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   __ AssertGeneratorObject(r3);
 
   // Store input value into generator object.
-  __ StoreP(r2, FieldMemOperand(r3, JSGeneratorObject::kInputOrDebugPosOffset),
-            r0);
+  __ StoreTaggedField(
+      r2, FieldMemOperand(r3, JSGeneratorObject::kInputOrDebugPosOffset), r0);
   __ RecordWriteField(r3, JSGeneratorObject::kInputOrDebugPosOffset, r2, r5,
                       kLRHasNotBeenSaved, kDontSaveFPRegs);
 
   // Load suspended function and context.
-  __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
-  __ LoadP(cp, FieldMemOperand(r6, JSFunction::kContextOffset));
+  __ LoadTaggedPointerField(
+      r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
+  __ LoadTaggedPointerField(cp,
+                            FieldMemOperand(r6, JSFunction::kContextOffset));
 
   // Flood function if we are stepping.
   Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
@@ -416,12 +427,14 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ LoadP(scratch, RealStackLimitAsMemOperand(masm));
+  __ LoadP(scratch,
+           StackLimitAsMemOperand(masm, StackLimitKind::kRealStackLimit));
   __ CmpLogicalP(sp, scratch);
   __ blt(&stack_overflow);
 
   // Push receiver.
-  __ LoadP(scratch, FieldMemOperand(r3, JSGeneratorObject::kReceiverOffset));
+  __ LoadTaggedPointerField(
+      scratch, FieldMemOperand(r3, JSGeneratorObject::kReceiverOffset));
   __ Push(scratch);
 
   // ----------- S t a t e -------------
@@ -433,28 +446,32 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // -----------------------------------
 
   // Copy the function arguments from the generator object's register file.
-  __ LoadP(r5, FieldMemOperand(r6, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r5, FieldMemOperand(r6, JSFunction::kSharedFunctionInfoOffset));
   __ LoadLogicalHalfWordP(
       r5, FieldMemOperand(r5, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ LoadP(r4, FieldMemOperand(
-                   r3, JSGeneratorObject::kParametersAndRegistersOffset));
+  __ LoadTaggedPointerField(
+      r4,
+      FieldMemOperand(r3, JSGeneratorObject::kParametersAndRegistersOffset));
   {
     Label loop, done_loop;
-    __ ShiftLeftP(r5, r5, Operand(kSystemPointerSizeLog2));
-    __ SubP(sp, r5);
+    __ ShiftLeftP(r1, r5, Operand(kSystemPointerSizeLog2));
+    __ SubP(sp, r1);
+
+    __ ShiftLeftP(r5, r5, Operand(kTaggedSizeLog2));
 
     // ip = stack offset
     // r5 = parameter array offset
     __ LoadImmP(ip, Operand::Zero());
-    __ SubP(r5, Operand(kSystemPointerSize));
+    __ SubP(r5, Operand(kTaggedSize));
     __ blt(&done_loop);
 
-    __ lgfi(r1, Operand(-kSystemPointerSize));
+    __ lghi(r1, Operand(-kTaggedSize));
 
     __ bind(&loop);
 
     // parameter copy loop
-    __ LoadP(r0, FieldMemOperand(r4, r5, FixedArray::kHeaderSize));
+    __ LoadAnyTaggedField(r0, FieldMemOperand(r4, r5, FixedArray::kHeaderSize));
     __ StoreP(r0, MemOperand(sp, ip));
 
     // update offsets
@@ -467,8 +484,10 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
 
   // Underlying function needs to have bytecode available.
   if (FLAG_debug_code) {
-    __ LoadP(r5, FieldMemOperand(r6, JSFunction::kSharedFunctionInfoOffset));
-    __ LoadP(r5, FieldMemOperand(r5, SharedFunctionInfo::kFunctionDataOffset));
+    __ LoadTaggedPointerField(
+        r5, FieldMemOperand(r6, JSFunction::kSharedFunctionInfoOffset));
+    __ LoadTaggedPointerField(
+        r5, FieldMemOperand(r5, SharedFunctionInfo::kFunctionDataOffset));
     GetSharedFunctionInfoBytecode(masm, r5, ip);
     __ CompareObjectType(r5, r5, r5, BYTECODE_ARRAY_TYPE);
     __ Assert(eq, AbortReason::kMissingBytecodeArray);
@@ -482,7 +501,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ LoadRR(r5, r3);
     __ LoadRR(r3, r6);
     static_assert(kJavaScriptCallCodeStartRegister == r4, "ABI mismatch");
-    __ LoadP(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
+    __ LoadTaggedPointerField(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
     __ JumpCodeObject(r4);
   }
 
@@ -494,7 +513,8 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ PushRoot(RootIndex::kTheHoleValue);
     __ CallRuntime(Runtime::kDebugOnFunctionCall);
     __ Pop(r3);
-    __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
+    __ LoadTaggedPointerField(
+        r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
   }
   __ b(&stepping_prepared);
 
@@ -504,7 +524,8 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ Push(r3);
     __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
     __ Pop(r3);
-    __ LoadP(r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
+    __ LoadTaggedPointerField(
+        r6, FieldMemOperand(r3, JSGeneratorObject::kFunctionOffset));
   }
   __ b(&stepping_prepared);
 
@@ -761,7 +782,8 @@ static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
-  __ LoadP(scratch1, RealStackLimitAsMemOperand(masm));
+  __ LoadP(scratch1,
+           StackLimitAsMemOperand(masm, StackLimitKind::kRealStackLimit));
   // Make scratch1 the space we have left. The stack might already be overflowed
   // here which will cause scratch1 to become negative.
   __ SubP(scratch1, sp, scratch1);
@@ -902,8 +924,8 @@ static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                                                 Register scratch1,
                                                 Register scratch2) {
   // Store code entry in the closure.
-  __ StoreP(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset),
-            r0);
+  __ StoreTaggedField(optimized_code,
+                      FieldMemOperand(closure, JSFunction::kCodeOffset), r0);
   __ LoadRR(scratch1,
             optimized_code);  // Write barrier clobbers scratch1 below.
   __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
@@ -952,8 +974,9 @@ static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
   // Check if the optimized code is marked for deopt. If it is, call the
   // runtime to clear it.
   Label found_deoptimized_code;
-  __ LoadP(scratch, FieldMemOperand(optimized_code_entry,
-                                    Code::kCodeDataContainerOffset));
+  __ LoadTaggedPointerField(
+      scratch,
+      FieldMemOperand(optimized_code_entry, Code::kCodeDataContainerOffset));
   __ LoadW(scratch, FieldMemOperand(
                         scratch, CodeDataContainer::kKindSpecificFlagsOffset));
   __ TestBit(scratch, Code::kMarkedForDeoptimizationBit, r0);
@@ -1008,18 +1031,27 @@ static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register bytecode, Register scratch1,
-                                          Label* if_return) {
+                                          Register scratch2, Label* if_return) {
   Register bytecode_size_table = scratch1;
-  Register scratch2 = bytecode;
+  Register scratch3 = bytecode;
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch2;
   DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+                     bytecode, original_bytecode_offset));
   __ Move(bytecode_size_table,
           ExternalReference::bytecode_size_table_address());
+  __ Move(original_bytecode_offset, bytecode_offset);
 
   // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
   Label process_bytecode, extra_wide;
@@ -1050,7 +1082,7 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   // Load the size of the current bytecode.
   __ bind(&process_bytecode);
 
-// Bailout to the return label if this is a return bytecode.
+  // Bailout to the return label if this is a return bytecode.
 #define JUMP_IF_EQUAL(NAME)                                           \
   __ CmpP(bytecode,                                                   \
           Operand(static_cast<int>(interpreter::Bytecode::k##NAME))); \
@@ -1058,10 +1090,24 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ CmpP(bytecode,
+          Operand(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ bne(&not_jump_loop);
+  // We need to restore the original bytecode_offset since we might have
+  // increased it to skip the wide / extra-wide prefix bytecode.
+  __ Move(bytecode_offset, original_bytecode_offset);
+  __ b(&end);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
-  __ ShiftLeftP(scratch2, bytecode, Operand(2));
-  __ LoadlW(scratch2, MemOperand(bytecode_size_table, scratch2));
-  __ AddP(bytecode_offset, bytecode_offset, scratch2);
+  __ ShiftLeftP(scratch3, bytecode, Operand(2));
+  __ LoadlW(scratch3, MemOperand(bytecode_size_table, scratch3));
+  __ AddP(bytecode_offset, bytecode_offset, scratch3);
+
+  __ bind(&end);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1086,10 +1132,12 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
   // Get the bytecode array from the function object and load it into
   // kInterpreterBytecodeArrayRegister.
-  __ LoadP(r2, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r2, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
   // Load original bytecode array or the debug copy.
-  __ LoadP(kInterpreterBytecodeArrayRegister,
-           FieldMemOperand(r2, SharedFunctionInfo::kFunctionDataOffset));
+  __ LoadTaggedPointerField(
+      kInterpreterBytecodeArrayRegister,
+      FieldMemOperand(r2, SharedFunctionInfo::kFunctionDataOffset));
   GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister, r6);
 
   // The bytecode array could have been flushed from the shared function info,
@@ -1100,15 +1148,17 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ bne(&compile_lazy);
 
   // Load the feedback vector from the closure.
-  __ LoadP(feedback_vector,
-           FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
-  __ LoadP(feedback_vector,
-           FieldMemOperand(feedback_vector, Cell::kValueOffset));
+  __ LoadTaggedPointerField(
+      feedback_vector,
+      FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
+  __ LoadTaggedPointerField(
+      feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
 
   Label push_stack_frame;
   // Check if feedback vector is valid. If valid, check for optimized code
   // and update invocation count. Otherwise, setup the stack frame.
-  __ LoadP(r6, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
+  __ LoadTaggedPointerField(
+      r6, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
   __ LoadLogicalHalfWordP(r6, FieldMemOperand(r6, Map::kInstanceTypeOffset));
   __ CmpP(r6, Operand(FEEDBACK_VECTOR_TYPE));
   __ bne(&push_stack_frame);
@@ -1116,9 +1166,10 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   Register optimized_code_entry = r6;
 
   // Read off the optimized code slot in the feedback vector.
-  __ LoadP(optimized_code_entry,
-           FieldMemOperand(feedback_vector,
-                           FeedbackVector::kOptimizedCodeWeakOrSmiOffset));
+  __ LoadAnyTaggedField(
+      optimized_code_entry,
+      FieldMemOperand(feedback_vector,
+                      FeedbackVector::kOptimizedCodeWeakOrSmiOffset));
 
   // Check if the optimized code slot is not empty.
   Label optimized_code_slot_not_empty;
@@ -1172,7 +1223,8 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
 
     // Do a stack check to ensure we don't go over the limit.
     __ SubP(r8, sp, r4);
-    __ CmpLogicalP(r8, RealStackLimitAsMemOperand(masm));
+    __ CmpLogicalP(
+        r8, StackLimitAsMemOperand(masm, StackLimitKind::kRealStackLimit));
     __ blt(&stack_overflow);
 
     // If ok, push undefined as the initial value for all register file entries.
@@ -1202,6 +1254,15 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ StoreP(r5, MemOperand(fp, r8));
   __ bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  __ LoadP(r5,
+           StackLimitAsMemOperand(masm, StackLimitKind::kInterruptStackLimit));
+  __ CmpLogicalP(sp, r5);
+  __ blt(&stack_check_interrupt);
+  __ bind(&after_stack_check_interrupt);
+
   // The accumulator is already loaded with undefined.
 
   // Load the dispatch table into a register and dispatch to the bytecode
@@ -1236,7 +1297,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ LoadlB(r3, MemOperand(kInterpreterBytecodeArrayRegister,
                            kInterpreterBytecodeOffsetRegister));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r3, r4,
+                                kInterpreterBytecodeOffsetRegister, r3, r4, r5,
                                 &do_return);
   __ b(&do_dispatch);
 
@@ -1254,6 +1315,31 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   // Fall through if there's no runnable optimized code.
   __ jmp(&not_optimized);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                              kFunctionEntryBytecodeOffset)));
+  __ StoreP(kInterpreterBytecodeOffsetRegister,
+            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ LoadP(kInterpreterBytecodeArrayRegister,
+           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(r5, kInterpreterBytecodeOffsetRegister);
+  __ StoreP(r5,
+            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&maybe_has_optimized_code);
   // Load code entry from the weak reference, if it was cleared, resume
   // execution of unoptimized code.
@@ -1401,15 +1487,17 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   // get the custom trampoline, otherwise grab the entry address of the global
   // trampoline.
   __ LoadP(r4, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-  __ LoadP(r4, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
-  __ LoadP(r4, FieldMemOperand(r4, SharedFunctionInfo::kFunctionDataOffset));
+  __ LoadTaggedPointerField(
+      r4, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r4, FieldMemOperand(r4, SharedFunctionInfo::kFunctionDataOffset));
   __ CompareObjectType(r4, kInterpreterDispatchTableRegister,
                        kInterpreterDispatchTableRegister,
                        INTERPRETER_DATA_TYPE);
   __ bne(&builtin_trampoline);
 
-  __ LoadP(r4,
-           FieldMemOperand(r4, InterpreterData::kInterpreterTrampolineOffset));
+  __ LoadTaggedPointerField(
+      r4, FieldMemOperand(r4, InterpreterData::kInterpreterTrampolineOffset));
   __ AddP(r4, r4, Operand(Code::kHeaderSize - kHeapObjectTag));
   __ b(&trampoline_loaded);
 
@@ -1447,6 +1535,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ CmpP(kInterpreterBytecodeOffsetRegister,
+            Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    __ bge(&okay);
+    __ bkpt(0);
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   UseScratchRegisterScope temps(masm);
   Register scratch = temps.Acquire();
@@ -1466,6 +1563,12 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
            MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
   __ SmiUntag(kInterpreterBytecodeOffsetRegister);
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ CmpP(kInterpreterBytecodeOffsetRegister,
+          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                  kFunctionEntryBytecodeOffset));
+  __ beq(&function_entry_bytecode);
+
   // Load the current bytecode.
   __ LoadlB(r3, MemOperand(kInterpreterBytecodeArrayRegister,
                            kInterpreterBytecodeOffsetRegister));
@@ -1473,9 +1576,10 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   // Advance to the next bytecode.
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
-                                kInterpreterBytecodeOffsetRegister, r3, r4,
+                                kInterpreterBytecodeOffsetRegister, r3, r4, r5,
                                 &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(r4, kInterpreterBytecodeOffsetRegister);
   __ StoreP(r4,
@@ -1483,6 +1587,15 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ mov(kInterpreterBytecodeOffsetRegister,
+         Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ b(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -1580,13 +1693,14 @@ void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
 
   // Load deoptimization data from the code object.
   // <deopt_data> = <code>[#deoptimization_data_offset]
-  __ LoadP(r3, FieldMemOperand(r2, Code::kDeoptimizationDataOffset));
+  __ LoadTaggedPointerField(
+      r3, FieldMemOperand(r2, Code::kDeoptimizationDataOffset));
 
   // Load the OSR entrypoint offset from the deoptimization data.
   // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
-  __ LoadP(r3, FieldMemOperand(r3, FixedArray::OffsetOfElementAt(
-                                       DeoptimizationData::kOsrPcOffsetIndex)));
-  __ SmiUntag(r3);
+  __ SmiUntagField(
+      r3, FieldMemOperand(r3, FixedArray::OffsetOfElementAt(
+                                  DeoptimizationData::kOsrPcOffsetIndex)));
 
   // Compute the target address = code_obj + header_size + osr_offset
   // <entry_addr> = <code_obj> + #header_size + <osr_offset>
@@ -1865,7 +1979,8 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     // Allow r4 to be a FixedArray, or a FixedDoubleArray if r6 == 0.
     Label ok, fail;
     __ AssertNotSmi(r4);
-    __ LoadP(scratch, FieldMemOperand(r4, HeapObject::kMapOffset));
+    __ LoadTaggedPointerField(scratch,
+                              FieldMemOperand(r4, HeapObject::kMapOffset));
     __ LoadHalfWordP(scratch,
                      FieldMemOperand(scratch, Map::kInstanceTypeOffset));
     __ CmpP(scratch, Operand(FIXED_ARRAY_TYPE));
@@ -1890,13 +2005,12 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     Label loop, no_args, skip;
     __ CmpP(r6, Operand::Zero());
     __ beq(&no_args);
-    __ AddP(
-        r4, r4,
-        Operand(FixedArray::kHeaderSize - kHeapObjectTag - kSystemPointerSize));
+    __ AddP(r4, r4,
+            Operand(FixedArray::kHeaderSize - kHeapObjectTag - kTaggedSize));
     __ LoadRR(r1, r6);
     __ bind(&loop);
-    __ LoadP(scratch, MemOperand(r4, kSystemPointerSize));
-    __ la(r4, MemOperand(r4, kSystemPointerSize));
+    __ LoadAnyTaggedField(scratch, MemOperand(r4, kTaggedSize), r0);
+    __ la(r4, MemOperand(r4, kTaggedSize));
     __ CompareRoot(scratch, RootIndex::kTheHoleValue);
     __ bne(&skip, Label::kNear);
     __ LoadRoot(scratch, RootIndex::kUndefinedValue);
@@ -1930,7 +2044,8 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
   if (mode == CallOrConstructMode::kConstruct) {
     Label new_target_constructor, new_target_not_constructor;
     __ JumpIfSmi(r5, &new_target_not_constructor);
-    __ LoadP(scratch, FieldMemOperand(r5, HeapObject::kMapOffset));
+    __ LoadTaggedPointerField(scratch,
+                              FieldMemOperand(r5, HeapObject::kMapOffset));
     __ LoadlB(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
     __ tmll(scratch, Operand(Map::Bits1::IsConstructorBit::kShift));
     __ bne(&new_target_constructor);
@@ -1954,7 +2069,8 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
   __ beq(&arguments_adaptor);
   {
     __ LoadP(r7, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
-    __ LoadP(r7, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
+    __ LoadTaggedPointerField(
+        r7, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
     __ LoadLogicalHalfWordP(
         r7,
         FieldMemOperand(r7, SharedFunctionInfo::kFormalParameterCountOffset));
@@ -2014,7 +2130,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
   // Check that the function is not a "classConstructor".
   Label class_constructor;
-  __ LoadP(r4, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r4, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
   __ LoadlW(r5, FieldMemOperand(r4, SharedFunctionInfo::kFlagsOffset));
   __ TestBitMask(r5, SharedFunctionInfo::IsClassConstructorBit::kMask, r0);
   __ bne(&class_constructor);
@@ -2022,7 +2139,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   // Enter the context of the function; ToObject has to run in the function
   // context, and we also need to take the global proxy from the function
   // context in case of conversion.
-  __ LoadP(cp, FieldMemOperand(r3, JSFunction::kContextOffset));
+  __ LoadTaggedPointerField(cp,
+                            FieldMemOperand(r3, JSFunction::kContextOffset));
   // We need to convert the receiver for non-native sloppy mode functions.
   Label done_convert;
   __ AndP(r0, r5,
@@ -2076,7 +2194,8 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
         __ Pop(r2, r3);
         __ SmiUntag(r2);
       }
-      __ LoadP(r4, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+      __ LoadTaggedPointerField(
+          r4, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
       __ bind(&convert_receiver);
     }
     __ ShiftLeftP(r6, r2, Operand(kSystemPointerSizeLog2));
@@ -2115,9 +2234,9 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
 
   // Load [[BoundArguments]] into r4 and length of that into r6.
   Label no_bound_arguments;
-  __ LoadP(r4, FieldMemOperand(r3, JSBoundFunction::kBoundArgumentsOffset));
-  __ LoadP(r6, FieldMemOperand(r4, FixedArray::kLengthOffset));
-  __ SmiUntag(r6);
+  __ LoadTaggedPointerField(
+      r4, FieldMemOperand(r3, JSBoundFunction::kBoundArgumentsOffset));
+  __ SmiUntagField(r6, FieldMemOperand(r4, FixedArray::kLengthOffset));
   __ LoadAndTestP(r6, r6);
   __ beq(&no_bound_arguments);
   {
@@ -2133,16 +2252,15 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     // Reserve stack space for the [[BoundArguments]].
     {
       Label done;
-      __ LoadRR(scratch, sp);  // preserve previous stack pointer
       __ ShiftLeftP(r9, r6, Operand(kSystemPointerSizeLog2));
-      __ SubP(sp, sp, r9);
+      __ SubP(r1, sp, r9);
       // Check the stack for overflow. We are not trying to catch interruptions
       // (i.e. debug break and preemption) here, so check the "real stack
       // limit".
-      __ CmpLogicalP(sp, RealStackLimitAsMemOperand(masm));
+      __ CmpLogicalP(
+          r1, StackLimitAsMemOperand(masm, StackLimitKind::kRealStackLimit));
       __ bgt(&done);  // Signed comparison.
       // Restore the stack pointer.
-      __ LoadRR(sp, scratch);
       {
         FrameScope scope(masm, StackFrame::MANUAL);
         __ EnterFrame(StackFrame::INTERNAL);
@@ -2151,10 +2269,12 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       __ bind(&done);
     }
 
+    __ LoadRR(scratch, sp);
+    __ LoadRR(sp, r1);
+
     // Relocate arguments down the stack.
     //  -- r2 : the number of arguments (not including the receiver)
     //  -- r8 : the previous stack pointer
-    //  -- r9: the size of the [[BoundArguments]]
     {
       Label skip, loop;
       __ LoadImmP(r7, Operand::Zero());
@@ -2164,7 +2284,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       __ bind(&loop);
       __ LoadP(r0, MemOperand(scratch, r7));
       __ StoreP(r0, MemOperand(sp, r7));
-      __ AddP(r7, r7, Operand(kSystemPointerSize));
+      __ lay(r7, MemOperand(r7, kSystemPointerSize));
       __ BranchOnCount(r1, &loop);
       __ bind(&skip);
     }
@@ -2172,14 +2292,14 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     // Copy [[BoundArguments]] to the stack (below the arguments).
     {
       Label loop;
-      __ AddP(r4, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
-      __ AddP(r4, r4, r9);
+      __ ShiftLeftP(r9, r6, Operand(kTaggedSizeLog2));
+      __ lay(r4, MemOperand(r4, r9, FixedArray::kHeaderSize - kHeapObjectTag));
       __ LoadRR(r1, r6);
       __ bind(&loop);
-      __ LoadP(r0, MemOperand(r4, -kSystemPointerSize));
-      __ lay(r4, MemOperand(r4, -kSystemPointerSize));
-      __ StoreP(r0, MemOperand(sp, r7));
-      __ AddP(r7, r7, Operand(kSystemPointerSize));
+      __ LoadAnyTaggedField(ip, MemOperand(r4, -kTaggedSize), r0);
+      __ lay(r4, MemOperand(r4, -kTaggedSize));
+      __ StoreP(ip, MemOperand(sp, r7));
+      __ lay(r7, MemOperand(r7, kSystemPointerSize));
       __ BranchOnCount(r1, &loop);
       __ AddP(r2, r2, r6);
     }
@@ -2198,7 +2318,8 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
   __ AssertBoundFunction(r3);
 
   // Patch the receiver to [[BoundThis]].
-  __ LoadP(r5, FieldMemOperand(r3, JSBoundFunction::kBoundThisOffset));
+  __ LoadAnyTaggedField(r5,
+                        FieldMemOperand(r3, JSBoundFunction::kBoundThisOffset));
   __ ShiftLeftP(r1, r2, Operand(kSystemPointerSizeLog2));
   __ StoreP(r5, MemOperand(sp, r1));
 
@@ -2206,8 +2327,8 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
   Generate_PushBoundArguments(masm);
 
   // Call the [[BoundTargetFunction]] via the Call builtin.
-  __ LoadP(r3,
-           FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
+  __ LoadTaggedPointerField(
+      r3, FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
   __ Jump(BUILTIN_CODE(masm->isolate(), Call_ReceiverIsAny),
           RelocInfo::CODE_TARGET);
 }
@@ -2275,7 +2396,8 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
   Label call_generic_stub;
 
   // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
-  __ LoadP(r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
   __ LoadlW(r6, FieldMemOperand(r6, SharedFunctionInfo::kFlagsOffset));
   __ AndP(r6, Operand(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
   __ beq(&call_generic_stub);
@@ -2303,15 +2425,15 @@ void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
 
   // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
   Label skip;
-  __ CmpP(r3, r5);
+  __ CompareTagged(r3, r5);
   __ bne(&skip);
-  __ LoadP(r5,
-           FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
+  __ LoadTaggedPointerField(
+      r5, FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
   __ bind(&skip);
 
   // Construct the [[BoundTargetFunction]] via the Construct builtin.
-  __ LoadP(r3,
-           FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
+  __ LoadTaggedPointerField(
+      r3, FieldMemOperand(r3, JSBoundFunction::kBoundTargetFunctionOffset));
   __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
 }
 
@@ -2329,7 +2451,7 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   __ JumpIfSmi(r3, &non_constructor);
 
   // Check if target has a [[Construct]] internal method.
-  __ LoadP(r6, FieldMemOperand(r3, HeapObject::kMapOffset));
+  __ LoadTaggedPointerField(r6, FieldMemOperand(r3, HeapObject::kMapOffset));
   __ LoadlB(r4, FieldMemOperand(r6, Map::kBitFieldOffset));
   __ TestBit(r4, Map::Bits1::IsConstructorBit::kShift);
   __ beq(&non_constructor);
@@ -2379,9 +2501,10 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // -----------------------------------
 
   Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
-  __ tmll(r4, Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+  __ tmll(r4, Operand(kDontAdaptArgumentsSentinel));
   __ b(Condition(1), &dont_adapt_arguments);
-  __ LoadP(r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r6, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
   __ LoadlW(r6, FieldMemOperand(r6, SharedFunctionInfo::kFlagsOffset));
   __ tmlh(r6,
           Operand(SharedFunctionInfo::IsSafeToSkipArgumentsAdaptorBit::kMask >>
@@ -2485,7 +2608,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // r3 : function (passed through to callee)
     // r5 : new target (passed through to callee)
     static_assert(kJavaScriptCallCodeStartRegister == r4, "ABI mismatch");
-    __ LoadP(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
+    __ LoadTaggedPointerField(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
     __ CallCodeObject(r4);
 
     // Store offset of return address for deoptimizer.
@@ -2537,8 +2660,9 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // Dont adapt arguments.
   // -------------------------------------------
   __ bind(&dont_adapt_arguments);
+  __ RecordComment("-- Call without adapting args --");
   static_assert(kJavaScriptCallCodeStartRegister == r4, "ABI mismatch");
-  __ LoadP(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
+  __ LoadTaggedPointerField(r4, FieldMemOperand(r3, JSFunction::kCodeOffset));
   __ JumpCodeObject(r4);
 
   __ bind(&stack_overflow);
@@ -2588,6 +2712,28 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ Jump(ip);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameAndConstantPoolScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    __ MultiPush(WasmDebugBreakFrameConstants::kPushedGpRegs);
+    __ MultiPushDoubles(WasmDebugBreakFrameConstants::kPushedFpRegs);
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ LoadSmiLiteral(cp, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    __ MultiPopDoubles(WasmDebugBreakFrameConstants::kPushedFpRegs);
+    __ MultiPop(WasmDebugBreakFrameConstants::kPushedGpRegs);
+  }
+  __ Ret();
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
@@ -3144,14 +3290,16 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
 
   __ push(receiver);
   // Push data from AccessorInfo.
-  __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
+  __ LoadAnyTaggedField(
+      scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset), r1);
   __ push(scratch);
   __ LoadRoot(scratch, RootIndex::kUndefinedValue);
   __ Push(scratch, scratch);
   __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
   __ Push(scratch, holder);
   __ Push(Smi::zero());  // should_throw_on_error -> false
-  __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kNameOffset));
+  __ LoadTaggedPointerField(
+      scratch, FieldMemOperand(callback, AccessorInfo::kNameOffset), r1);
   __ push(scratch);
 
   // v8::PropertyCallbackInfo::args_ array and name handle.
@@ -3200,7 +3348,8 @@ void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
   ExternalReference thunk_ref =
       ExternalReference::invoke_accessor_getter_callback();
 
-  __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
+  __ LoadTaggedPointerField(
+      scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
   __ LoadP(api_function_address,
            FieldMemOperand(scratch, Foreign::kForeignAddressOffset));
 
diff --git a/deps/v8/src/builtins/setup-builtins-internal.cc b/deps/v8/src/builtins/setup-builtins-internal.cc
index e3f39a0906..4739e18c57 100644
--- a/deps/v8/src/builtins/setup-builtins-internal.cc
+++ b/deps/v8/src/builtins/setup-builtins-internal.cc
@@ -7,6 +7,7 @@
 #include "src/builtins/builtins.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/interface-descriptors.h"
+#include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/compiler/code-assembler.h"
 #include "src/execution/isolate.h"
@@ -42,8 +43,7 @@ AssemblerOptions BuiltinAssemblerOptions(Isolate* isolate,
     return options;
   }
 
-  const base::AddressRegion& code_range =
-      isolate->heap()->memory_allocator()->code_range();
+  const base::AddressRegion& code_range = isolate->heap()->code_range();
   bool pc_relative_calls_fit_in_code_range =
       !code_range.is_empty() &&
       std::ceil(static_cast<float>(code_range.size() / MB)) <=
@@ -97,6 +97,7 @@ Code BuildWithMacroAssembler(Isolate* isolate, int32_t builtin_index,
                       ExternalAssemblerBuffer(buffer, kBufferSize));
   masm.set_builtin_index(builtin_index);
   DCHECK(!masm.has_frame());
+  masm.CodeEntry();
   generator(&masm);
 
   int handler_table_offset = 0;
@@ -159,7 +160,7 @@ Code BuildWithCodeStubAssemblerJS(Isolate* isolate, int32_t builtin_index,
 
   Zone zone(isolate->allocator(), ZONE_NAME);
   const int argc_with_recv =
-      (argc == SharedFunctionInfo::kDontAdaptArgumentsSentinel) ? 0 : argc + 1;
+      (argc == kDontAdaptArgumentsSentinel) ? 0 : argc + 1;
   compiler::CodeAssemblerState state(
       isolate, &zone, argc_with_recv, Code::BUILTIN, name,
       PoisoningMitigationLevel::kDontPoison, builtin_index);
diff --git a/deps/v8/src/builtins/string-repeat.tq b/deps/v8/src/builtins/string-repeat.tq
index 1c14be6cb4..e3e72ae7b5 100644
--- a/deps/v8/src/builtins/string-repeat.tq
+++ b/deps/v8/src/builtins/string-repeat.tq
@@ -36,7 +36,7 @@ namespace string {
 
     try {
       // 3. Let n be ? ToInteger(count).
-      typeswitch (ToInteger_Inline(count, kTruncateMinusZero)) {
+      typeswitch (ToInteger_Inline(count)) {
         case (n: Smi): {
           // 4. If n < 0, throw a RangeError exception.
           if (n < 0) goto InvalidCount;
diff --git a/deps/v8/src/builtins/torque-internal.tq b/deps/v8/src/builtins/torque-internal.tq
index 47e91c93dc..85c43342cf 100644
--- a/deps/v8/src/builtins/torque-internal.tq
+++ b/deps/v8/src/builtins/torque-internal.tq
@@ -17,13 +17,12 @@ namespace torque_internal {
     const offset: intptr;
     unsafeMarker: Unsafe;
   }
+  type ConstReference<T: type> extends Reference<T>;
+  type MutableReference<T: type> extends ConstReference<T>;
 
   macro UnsafeNewReference<T: type>(object: HeapObject, offset: intptr):&T {
-    return Reference<T>{
-      object: object,
-      offset: offset,
-      unsafeMarker: Unsafe {}
-    };
+    return %RawDownCast<&T>(
+        Reference<T>{object: object, offset: offset, unsafeMarker: Unsafe {}});
   }
 
   struct Slice<T: type> {
@@ -148,7 +147,7 @@ namespace torque_internal {
   type UninitializedHeapObject extends HeapObject;
 
   extern macro AllocateAllowLOS(intptr): UninitializedHeapObject;
-  extern macro GetStructMap(constexpr InstanceType): Map;
+  extern macro GetInstanceTypeMap(constexpr InstanceType): Map;
 
   macro Allocate(sizeInBytes: intptr, map: Map): UninitializedHeapObject {
     assert(ValidAllocationSize(sizeInBytes, map));
diff --git a/deps/v8/src/builtins/typed-array-createtypedarray.tq b/deps/v8/src/builtins/typed-array-createtypedarray.tq
index 77a0b404be..e5398fc50a 100644
--- a/deps/v8/src/builtins/typed-array-createtypedarray.tq
+++ b/deps/v8/src/builtins/typed-array-createtypedarray.tq
@@ -13,8 +13,6 @@ namespace typed_array {
   extern macro CodeStubAssembler::AllocateByteArray(uintptr): ByteArray;
   extern macro TypedArrayBuiltinsAssembler::GetDefaultConstructor(
       implicit context: Context)(JSTypedArray): JSFunction;
-  extern macro TypedArrayBuiltinsAssembler::IsSharedArrayBuffer(JSArrayBuffer):
-      bool;
   extern macro TypedArrayBuiltinsAssembler::SetupTypedArrayEmbedderFields(
       JSTypedArray): void;
 
diff --git a/deps/v8/src/builtins/x64/builtins-x64.cc b/deps/v8/src/builtins/x64/builtins-x64.cc
index 99f052d695..8d028c88f0 100644
--- a/deps/v8/src/builtins/x64/builtins-x64.cc
+++ b/deps/v8/src/builtins/x64/builtins-x64.cc
@@ -5,17 +5,18 @@
 #if V8_TARGET_ARCH_X64
 
 #include "src/api/api-arguments.h"
+#include "src/base/bits-iterator.h"
 #include "src/base/iterator.h"
 #include "src/codegen/code-factory.h"
+// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
+#include "src/codegen/macro-assembler-inl.h"
+#include "src/codegen/register-configuration.h"
 #include "src/codegen/x64/assembler-x64.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
-#include "src/logging/counters.h"
-// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
-#include "src/codegen/macro-assembler-inl.h"
-#include "src/codegen/register-configuration.h"
 #include "src/heap/heap-inl.h"
+#include "src/logging/counters.h"
 #include "src/objects/cell.h"
 #include "src/objects/debug-objects.h"
 #include "src/objects/foreign.h"
@@ -23,6 +24,7 @@
 #include "src/objects/js-generator.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
+#include "src/wasm/baseline/liftoff-assembler-defs.h"
 #include "src/wasm/wasm-linkage.h"
 #include "src/wasm/wasm-objects.h"
 
@@ -65,10 +67,15 @@ static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
 
 namespace {
 
-Operand RealStackLimitAsOperand(MacroAssembler* masm) {
+enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };
+
+Operand StackLimitAsOperand(MacroAssembler* masm, StackLimitKind kind) {
   DCHECK(masm->root_array_available());
   Isolate* isolate = masm->isolate();
-  ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
+  ExternalReference limit =
+      kind == StackLimitKind::kRealStackLimit
+          ? ExternalReference::address_of_real_jslimit(isolate)
+          : ExternalReference::address_of_jslimit(isolate);
   DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
 
   intptr_t offset =
@@ -84,7 +91,8 @@ void Generate_StackOverflowCheck(
   // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
-  __ movq(kScratchRegister, RealStackLimitAsOperand(masm));
+  __ movq(kScratchRegister,
+          StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
   __ movq(scratch, rsp);
   // Make scratch the space we have left. The stack might already be overflowed
   // here which will cause scratch to become negative.
@@ -116,31 +124,22 @@ void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
     __ Push(rsi);
     __ Push(rcx);
 
+#ifdef V8_REVERSE_JSARGS
+    // Set up pointer to first argument (skip receiver).
+    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset +
+                                  kSystemPointerSize));
+    // Copy arguments to the expression stack.
+    __ PushArray(rbx, rax, rcx);
+    // The receiver for the builtin/api call.
+    __ PushRoot(RootIndex::kTheHoleValue);
+#else
     // The receiver for the builtin/api call.
     __ PushRoot(RootIndex::kTheHoleValue);
-
     // Set up pointer to last argument.
     __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
-
-    // Copy arguments and receiver to the expression stack.
-    Label loop, entry;
-    __ movq(rcx, rax);
-    // ----------- S t a t e -------------
-    //  --                      rax: number of arguments (untagged)
-    //  --                      rdi: constructor function
-    //  --                      rdx: new target
-    //  --                      rbx: pointer to last argument
-    //  --                      rcx: counter
-    //  -- sp[0*kSystemPointerSize]: the hole (receiver)
-    //  -- sp[1*kSystemPointerSize]: number of arguments (tagged)
-    //  -- sp[2*kSystemPointerSize]: context
-    // -----------------------------------
-    __ jmp(&entry);
-    __ bind(&loop);
-    __ Push(Operand(rbx, rcx, times_system_pointer_size, 0));
-    __ bind(&entry);
-    __ decq(rcx);
-    __ j(greater_equal, &loop, Label::kNear);
+    // Copy arguments to the expression stack.
+    __ PushArray(rbx, rax, rcx);
+#endif
 
     // Call the function.
     // rax: number of arguments (untagged)
@@ -238,28 +237,34 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
     // Restore new target.
     __ Pop(rdx);
 
-    // Push the allocated receiver to the stack. We need two copies
-    // because we may have to return the original one and the calling
-    // conventions dictate that the called function pops the receiver.
+    // Push the allocated receiver to the stack.
     __ Push(rax);
+
+#ifdef V8_REVERSE_JSARGS
+    // We need two copies because we may have to return the original one
+    // and the calling conventions dictate that the called function pops the
+    // receiver. The second copy is pushed after the arguments, we saved in r8
+    // since rax needs to store the number of arguments before
+    // InvokingFunction.
+    __ movq(r8, rax);
+
+    // Set up pointer to first argument (skip receiver).
+    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset +
+                                  kSystemPointerSize));
+#else
+    // We need two copies because we may have to return the original one
+    // and the calling conventions dictate that the called function pops the
+    // receiver.
     __ Push(rax);
 
-    // ----------- S t a t e -------------
-    //  -- sp[0*kSystemPointerSize]  implicit receiver
-    //  -- sp[1*kSystemPointerSize]  implicit receiver
-    //  -- sp[2*kSystemPointerSize]  padding
-    //  -- sp[3*kSystemPointerSize]  constructor function
-    //  -- sp[4*kSystemPointerSize]  number of arguments (tagged)
-    //  -- sp[5*kSystemPointerSize]  context
-    // -----------------------------------
+    // Set up pointer to last argument.
+    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
+#endif
 
     // Restore constructor function and argument count.
     __ movq(rdi, Operand(rbp, ConstructFrameConstants::kConstructorOffset));
     __ SmiUntag(rax, Operand(rbp, ConstructFrameConstants::kLengthOffset));
 
-    // Set up pointer to last argument.
-    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
-
     // Check if we have enough stack space to push all arguments.
     // Argument count in rax. Clobbers rcx.
     Label enough_stack_space, stack_overflow;
@@ -275,27 +280,13 @@ void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
 
     __ bind(&enough_stack_space);
 
-    // Copy arguments and receiver to the expression stack.
-    Label loop, entry;
-    __ movq(rcx, rax);
-    // ----------- S t a t e -------------
-    //  --                              rax: number of arguments (untagged)
-    //  --                              rdx: new target
-    //  --                              rbx: pointer to last argument
-    //  --                              rcx: counter (tagged)
-    //  --         sp[0*kSystemPointerSize]: implicit receiver
-    //  --         sp[1*kSystemPointerSize]: implicit receiver
-    //  --         sp[2*kSystemPointerSize]: padding
-    //  -- rdi and sp[3*kSystemPointerSize]: constructor function
-    //  --         sp[4*kSystemPointerSize]: number of arguments (tagged)
-    //  --         sp[5*kSystemPointerSize]: context
-    // -----------------------------------
-    __ jmp(&entry, Label::kNear);
-    __ bind(&loop);
-    __ Push(Operand(rbx, rcx, times_system_pointer_size, 0));
-    __ bind(&entry);
-    __ decq(rcx);
-    __ j(greater_equal, &loop, Label::kNear);
+    // Copy arguments to the expression stack.
+    __ PushArray(rbx, rax, rcx);
+
+#ifdef V8_REVERSE_JSARGS
+    // Push implicit receiver.
+    __ Push(r8);
+#endif
 
     // Call the function.
     __ InvokeFunction(rdi, rdx, rax, CALL_FUNCTION);
@@ -606,9 +597,13 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
         IsolateAddressId::kContextAddress, masm->isolate());
     __ movq(rsi, masm->ExternalReferenceAsOperand(context_address));
 
-    // Push the function and the receiver onto the stack.
+    // Push the function onto the stack.
     __ Push(rdi);
+
+#ifndef V8_REVERSE_JSARGS
+    // Push the receiver onto the stack.
     __ Push(arg_reg_4);
+#endif
 
 #ifdef V8_TARGET_OS_WIN
     // Load the previous frame pointer to access C arguments on stack
@@ -620,18 +615,25 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     // Load the number of arguments and setup pointer to the arguments.
     __ movq(rax, r8);
     __ movq(rbx, r9);
+#ifdef V8_REVERSE_JSARGS
+    __ movq(r9, arg_reg_4);  // Temporarily saving the receiver.
+#endif
 #endif  // V8_TARGET_OS_WIN
 
-    // Current stack contents:
-    // [rsp + 2 * kSystemPointerSize ... ] : Internal frame
-    // [rsp + kSystemPointerSize]          : function
-    // [rsp]                         : receiver
+    // Current stack contents if V8_REVERSE_JSARGS:
+    // [rsp + kSystemPointerSize]     : Internal frame
+    // [rsp]                          : function
+    // Current stack contents if not V8_REVERSE_JSARGS:
+    // [rsp + 2 * kSystemPointerSize] : Internal frame
+    // [rsp +     kSystemPointerSize] : function
+    // [rsp]                          : receiver
     // Current register contents:
     // rax : argc
     // rbx : argv
     // rsi : context
     // rdi : function
     // rdx : new.target
+    // r9  : receiver, if V8_REVERSE_JSARGS
 
     // Check if we have enough stack space to push all arguments.
     // Argument count in rax. Clobbers rcx.
@@ -649,6 +651,20 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     // Copy arguments to the stack in a loop.
     // Register rbx points to array of pointers to handle locations.
     // Push the values of these handles.
+#ifdef V8_REVERSE_JSARGS
+    Label loop, entry;
+    __ movq(rcx, rax);
+    __ jmp(&entry, Label::kNear);
+    __ bind(&loop);
+    __ movq(kScratchRegister, Operand(rbx, rcx, times_system_pointer_size, 0));
+    __ Push(Operand(kScratchRegister, 0));  // dereference handle
+    __ bind(&entry);
+    __ decq(rcx);
+    __ j(greater_equal, &loop, Label::kNear);
+
+    // Push the receiver.
+    __ Push(r9);
+#else
     Label loop, entry;
     __ Set(rcx, 0);  // Set loop variable to 0.
     __ jmp(&entry, Label::kNear);
@@ -659,6 +675,7 @@ static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
     __ bind(&entry);
     __ cmpq(rcx, rax);
     __ j(not_equal, &loop, Label::kNear);
+#endif
 
     // Invoke the builtin code.
     Handle<Code> builtin = is_construct
@@ -745,22 +762,24 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
   // Check the stack for overflow. We are not trying to catch interruptions
   // (i.e. debug break and preemption) here, so check the "real stack limit".
   Label stack_overflow;
-  __ cmpq(rsp, RealStackLimitAsOperand(masm));
+  __ cmpq(rsp, StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
   __ j(below, &stack_overflow);
 
   // Pop return address.
   __ PopReturnAddressTo(rax);
 
+#ifndef V8_REVERSE_JSARGS
   // Push receiver.
   __ PushTaggedPointerField(
       FieldOperand(rdx, JSGeneratorObject::kReceiverOffset), decompr_scratch1);
+#endif
 
   // ----------- S t a t e -------------
   //  -- rax    : return address
   //  -- rdx    : the JSGeneratorObject to resume
   //  -- rdi    : generator function
   //  -- rsi    : generator context
-  //  -- rsp[0] : generator receiver
+  //  -- rsp[0] : generator receiver, if V8_REVERSE_JSARGS is not set
   // -----------------------------------
 
   // Copy the function arguments from the generator object's register file.
@@ -773,6 +792,27 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
       rbx, FieldOperand(rdx, JSGeneratorObject::kParametersAndRegistersOffset));
 
   {
+#ifdef V8_REVERSE_JSARGS
+    {
+      Label done_loop, loop;
+      __ movq(r9, rcx);
+
+      __ bind(&loop);
+      __ decq(r9);
+      __ j(less, &done_loop, Label::kNear);
+      __ PushTaggedAnyField(
+          FieldOperand(rbx, r9, times_tagged_size, FixedArray::kHeaderSize),
+          decompr_scratch1);
+      __ jmp(&loop);
+
+      __ bind(&done_loop);
+    }
+
+    // Push the receiver.
+    __ PushTaggedPointerField(
+        FieldOperand(rdx, JSGeneratorObject::kReceiverOffset),
+        decompr_scratch1);
+#else
     Label done_loop, loop;
     __ Set(r9, 0);
 
@@ -786,6 +826,7 @@ void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
     __ jmp(&loop);
 
     __ bind(&done_loop);
+#endif
   }
 
   // Underlying function needs to have bytecode available.
@@ -963,15 +1004,25 @@ static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
 
 // Advance the current bytecode offset. This simulates what all bytecode
 // handlers do upon completion of the underlying operation. Will bail out to a
-// label if the bytecode (without prefix) is a return bytecode.
+// label if the bytecode (without prefix) is a return bytecode. Will not advance
+// the bytecode offset if the current bytecode is a JumpLoop, instead just
+// re-executing the JumpLoop to jump to the correct bytecode.
 static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                           Register bytecode_array,
                                           Register bytecode_offset,
                                           Register bytecode, Register scratch1,
-                                          Label* if_return) {
+                                          Register scratch2, Label* if_return) {
   Register bytecode_size_table = scratch1;
-  DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
-                     bytecode));
+
+  // The bytecode offset value will be increased by one in wide and extra wide
+  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
+  // will restore the original bytecode. In order to simplify the code, we have
+  // a backup of it.
+  Register original_bytecode_offset = scratch2;
+  DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode,
+                     bytecode_size_table, original_bytecode_offset));
+
+  __ movq(original_bytecode_offset, bytecode_offset);
 
   __ Move(bytecode_size_table,
           ExternalReference::bytecode_size_table_address());
@@ -1013,9 +1064,23 @@ static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
   RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
 #undef JUMP_IF_EQUAL
 
+  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
+  // of the loop.
+  Label end, not_jump_loop;
+  __ cmpb(bytecode,
+          Immediate(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
+  __ j(not_equal, &not_jump_loop, Label::kNear);
+  // We need to restore the original bytecode_offset since we might have
+  // increased it to skip the wide / extra-wide prefix bytecode.
+  __ movq(bytecode_offset, original_bytecode_offset);
+  __ jmp(&end, Label::kNear);
+
+  __ bind(&not_jump_loop);
   // Otherwise, load the size of the current bytecode and advance the offset.
   __ addl(bytecode_offset,
           Operand(bytecode_size_table, bytecode, times_int_size, 0));
+
+  __ bind(&end);
 }
 
 // Generate code for entering a JS function with the interpreter.
@@ -1127,7 +1192,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
     // Do a stack check to ensure we don't go over the limit.
     __ movq(rax, rsp);
     __ subq(rax, rcx);
-    __ cmpq(rax, RealStackLimitAsOperand(masm));
+    __ cmpq(rax, StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
     __ j(below, &stack_overflow);
 
     // If ok, push undefined as the initial value for all register file entries.
@@ -1156,6 +1221,13 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   __ movq(Operand(rbp, rcx, times_system_pointer_size, 0), rdx);
   __ bind(&no_incoming_new_target_or_generator_register);
 
+  // Perform interrupt stack check.
+  // TODO(solanes): Merge with the real stack limit check above.
+  Label stack_check_interrupt, after_stack_check_interrupt;
+  __ cmpq(rsp, StackLimitAsOperand(masm, StackLimitKind::kInterruptStackLimit));
+  __ j(below, &stack_check_interrupt);
+  __ bind(&after_stack_check_interrupt);
+
   // The accumulator is already loaded with undefined.
 
   // Load the dispatch table into a register and dispatch to the bytecode
@@ -1188,7 +1260,7 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, rbx, rcx,
-                                &do_return);
+                                r11, &do_return);
   __ jmp(&do_dispatch);
 
   __ bind(&do_return);
@@ -1196,6 +1268,28 @@ void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
   LeaveInterpreterFrame(masm, rbx, rcx);
   __ ret(0);
 
+  __ bind(&stack_check_interrupt);
+  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
+  // for the call to the StackGuard.
+  __ Move(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
+          Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                       kFunctionEntryBytecodeOffset));
+  __ CallRuntime(Runtime::kStackGuard);
+
+  // After the call, restore the bytecode array, bytecode offset and accumulator
+  // registers again. Also, restore the bytecode offset in the stack to its
+  // previous value.
+  __ movq(kInterpreterBytecodeArrayRegister,
+          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
+  __ movq(kInterpreterBytecodeOffsetRegister,
+          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
+
+  __ SmiTag(rcx, kInterpreterBytecodeArrayRegister);
+  __ movq(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp), rcx);
+
+  __ jmp(&after_stack_check_interrupt);
+
   __ bind(&compile_lazy);
   GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
   __ int3();  // Should not return.
@@ -1224,21 +1318,19 @@ static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                          Register num_args,
                                          Register start_address,
                                          Register scratch) {
-  // Find the address of the last argument.
-  __ Move(scratch, num_args);
-  __ shlq(scratch, Immediate(kSystemPointerSizeLog2));
+  // Find the argument with lowest address.
+  __ movq(scratch, num_args);
   __ negq(scratch);
-  __ addq(scratch, start_address);
-
+  __ leaq(start_address,
+          Operand(start_address, scratch, times_system_pointer_size,
+                  kSystemPointerSize));
   // Push the arguments.
-  Label loop_header, loop_check;
-  __ j(always, &loop_check, Label::kNear);
-  __ bind(&loop_header);
-  __ Push(Operand(start_address, 0));
-  __ subq(start_address, Immediate(kSystemPointerSize));
-  __ bind(&loop_check);
-  __ cmpq(start_address, scratch);
-  __ j(above, &loop_header, Label::kNear);
+#ifdef V8_REVERSE_JSARGS
+  __ PushArray(start_address, num_args, scratch,
+               TurboAssembler::PushArrayOrder::kReverse);
+#else
+  __ PushArray(start_address, num_args, scratch);
+#endif
 }
 
 // static
@@ -1255,7 +1347,13 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
   // -----------------------------------
   Label stack_overflow;
 
-  // Number of values to be pushed.
+#ifdef V8_REVERSE_JSARGS
+  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
+    // The spread argument should not be pushed.
+    __ decl(rax);
+  }
+#endif
+
   __ leal(rcx, Operand(rax, 1));  // Add one for receiver.
 
   // Add a stack check before pushing arguments.
@@ -1264,6 +1362,27 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
   // Pop return address to allow tail-call after pushing arguments.
   __ PopReturnAddressTo(kScratchRegister);
 
+#ifdef V8_REVERSE_JSARGS
+  if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
+    // Don't copy receiver.
+    __ decq(rcx);
+  }
+
+  // rbx and rdx will be modified.
+  Generate_InterpreterPushArgs(masm, rcx, rbx, rdx);
+
+  // Push "undefined" as the receiver arg if we need to.
+  if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
+    __ PushRoot(RootIndex::kUndefinedValue);
+  }
+
+  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
+    // Pass the spread in the register rbx.
+    // rbx already points to the penultime argument, the spread
+    // is below that.
+    __ movq(rbx, Operand(rbx, -kSystemPointerSize));
+  }
+#else
   // Push "undefined" as the receiver arg if we need to.
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
     __ PushRoot(RootIndex::kUndefinedValue);
@@ -1277,6 +1396,7 @@ void Builtins::Generate_InterpreterPushArgsThenCallImpl(
     __ Pop(rbx);                 // Pass the spread in a register
     __ decl(rax);                // Subtract one for spread
   }
+#endif
 
   // Call the target.
   __ PushReturnAddressFrom(kScratchRegister);  // Re-push return address.
@@ -1319,16 +1439,33 @@ void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
   // Pop return address to allow tail-call after pushing arguments.
   __ PopReturnAddressTo(kScratchRegister);
 
+#ifdef V8_REVERSE_JSARGS
+  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
+    // The spread argument should not be pushed.
+    __ decl(rax);
+  }
+
+  // rcx and r8 will be modified.
+  Generate_InterpreterPushArgs(masm, rax, rcx, r8);
+
+  // Push slot for the receiver to be constructed.
+  __ Push(Immediate(0));
+#else
   // Push slot for the receiver to be constructed.
   __ Push(Immediate(0));
 
   // rcx and r8 will be modified.
   Generate_InterpreterPushArgs(masm, rax, rcx, r8);
+#endif
 
   if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
+#ifdef V8_REVERSE_JSARGS
+    // Pass the spread in the register rbx.
+    __ movq(rbx, Operand(rcx, -kSystemPointerSize));
+#else
     __ Pop(rbx);                 // Pass the spread in a register
     __ decl(rax);                // Subtract one for spread
-
+#endif
     // Push return address in preparation for the tail-call.
     __ PushReturnAddressFrom(kScratchRegister);
   } else {
@@ -1423,6 +1560,15 @@ static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister,
               Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
+  if (FLAG_debug_code) {
+    Label okay;
+    __ cmpq(kInterpreterBytecodeOffsetRegister,
+            Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+    __ j(greater_equal, &okay, Label::kNear);
+    __ int3();
+    __ bind(&okay);
+  }
+
   // Dispatch to the target bytecode.
   __ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
@@ -1439,6 +1585,12 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   __ SmiUntag(kInterpreterBytecodeOffsetRegister,
               Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
 
+  Label enter_bytecode, function_entry_bytecode;
+  __ cmpq(kInterpreterBytecodeOffsetRegister,
+          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag +
+                    kFunctionEntryBytecodeOffset));
+  __ j(equal, &function_entry_bytecode);
+
   // Load the current bytecode.
   __ movzxbq(rbx, Operand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister, times_1, 0));
@@ -1447,8 +1599,9 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
   Label if_return;
   AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                 kInterpreterBytecodeOffsetRegister, rbx, rcx,
-                                &if_return);
+                                r11, &if_return);
 
+  __ bind(&enter_bytecode);
   // Convert new bytecode offset to a Smi and save in the stackframe.
   __ SmiTag(kInterpreterBytecodeOffsetRegister);
   __ movq(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
@@ -1456,6 +1609,15 @@ void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
 
   Generate_InterpreterEnterBytecode(masm);
 
+  __ bind(&function_entry_bytecode);
+  // If the code deoptimizes during the implicit function entry stack interrupt
+  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
+  // not a valid bytecode offset. Detect this case and advance to the first
+  // actual bytecode.
+  __ movq(kInterpreterBytecodeOffsetRegister,
+          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
+  __ jmp(&enter_bytecode);
+
   // We should never take the if_return path.
   __ bind(&if_return);
   __ Abort(AbortReason::kInvalidBytecodeAdvance);
@@ -1544,9 +1706,10 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax     : argc
   //  -- rsp[0]  : return address
-  //  -- rsp[8]  : argArray
-  //  -- rsp[16] : thisArg
-  //  -- rsp[24] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : thisArg
+  //  -- args[2] : argArray
   // -----------------------------------
 
   // 1. Load receiver into rdi, argArray into rbx (if present), remove all
@@ -1554,17 +1717,17 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // present) instead.
   {
     Label no_arg_array, no_this_arg;
-    StackArgumentsAccessor args(rsp, rax);
+    StackArgumentsAccessor args(rax);
     __ LoadRoot(rdx, RootIndex::kUndefinedValue);
     __ movq(rbx, rdx);
-    __ movq(rdi, args.GetReceiverOperand());
+    __ movq(rdi, args[0]);
     __ testq(rax, rax);
     __ j(zero, &no_this_arg, Label::kNear);
     {
-      __ movq(rdx, args.GetArgumentOperand(1));
+      __ movq(rdx, args[1]);
       __ cmpq(rax, Immediate(1));
       __ j(equal, &no_arg_array, Label::kNear);
-      __ movq(rbx, args.GetArgumentOperand(2));
+      __ movq(rbx, args[2]);
       __ bind(&no_arg_array);
     }
     __ bind(&no_this_arg);
@@ -1606,6 +1769,7 @@ void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
 }
 
 // static
+// TODO(victor): merge steps 1, 2 and 3 when V8_REVERSE_JSARGS is set.
 void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
   // Stack Layout:
   // rsp[0]           : Return address
@@ -1613,17 +1777,23 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
   // rsp[16]          : Argument n-1
   //  ...
   // rsp[8 * n]       : Argument 1
-  // rsp[8 * (n + 1)] : Receiver (callable to call)
-  //
+  // rsp[8 * (n + 1)] : Argument 0 (receiver: callable to call)
+  // NOTE: The order of args are reversed if V8_REVERSE_JSARGS
   // rax contains the number of arguments, n, not counting the receiver.
-  //
+
   // 1. Make sure we have at least one argument.
   {
     Label done;
     __ testq(rax, rax);
     __ j(not_zero, &done, Label::kNear);
     __ PopReturnAddressTo(rbx);
+#ifdef V8_REVERSE_JSARGS
+    __ Pop(kScratchRegister);  // Pop the receiver.
+    __ PushRoot(RootIndex::kUndefinedValue);
+    __ Push(kScratchRegister);
+#else
     __ PushRoot(RootIndex::kUndefinedValue);
+#endif
     __ PushReturnAddressFrom(rbx);
     __ incq(rax);
     __ bind(&done);
@@ -1631,25 +1801,34 @@ void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
 
   // 2. Get the callable to call (passed as receiver) from the stack.
   {
-    StackArgumentsAccessor args(rsp, rax);
+    StackArgumentsAccessor args(rax);
     __ movq(rdi, args.GetReceiverOperand());
   }
 
+#ifdef V8_REVERSE_JSARGS
+  // 3. Shift return address one slot down on the stack (overwriting the
+  // original receiver), making the original first argument the new receiver.
+  {
+    __ DropUnderReturnAddress(1, rbx);  // Drop one slot under return address.
+    __ decq(rax);  // One fewer argument (first argument is new receiver).
+  }
+#else
   // 3. Shift arguments and return address one slot down on the stack
   //    (overwriting the original receiver).  Adjust argument count to make
   //    the original first argument the new receiver.
   {
     Label loop;
     __ movq(rcx, rax);
-    StackArgumentsAccessor args(rsp, rcx);
+    StackArgumentsAccessor args(rcx);
     __ bind(&loop);
-    __ movq(rbx, args.GetArgumentOperand(1));
-    __ movq(args.GetArgumentOperand(0), rbx);
+    __ movq(rbx, args[1]);
+    __ movq(args[0], rbx);
     __ decq(rcx);
     __ j(not_zero, &loop);              // While non-zero.
     __ DropUnderReturnAddress(1, rbx);  // Drop one slot under return address.
     __ decq(rax);  // One fewer argument (first argument is new receiver).
   }
+#endif
 
   // 4. Call the callable.
   // Since we did not create a frame for Function.prototype.call() yet,
@@ -1661,10 +1840,11 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax     : argc
   //  -- rsp[0]  : return address
-  //  -- rsp[8]  : argumentsList
-  //  -- rsp[16] : thisArgument
-  //  -- rsp[24] : target
-  //  -- rsp[32] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : target
+  //  -- args[2] : thisArgument
+  //  -- args[3] : argumentsList
   // -----------------------------------
 
   // 1. Load target into rdi (if present), argumentsList into rbx (if present),
@@ -1672,18 +1852,18 @@ void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
   // thisArgument (if present) instead.
   {
     Label done;
-    StackArgumentsAccessor args(rsp, rax);
+    StackArgumentsAccessor args(rax);
     __ LoadRoot(rdi, RootIndex::kUndefinedValue);
     __ movq(rdx, rdi);
     __ movq(rbx, rdi);
     __ cmpq(rax, Immediate(1));
     __ j(below, &done, Label::kNear);
-    __ movq(rdi, args.GetArgumentOperand(1));  // target
+    __ movq(rdi, args[1]);  // target
     __ j(equal, &done, Label::kNear);
-    __ movq(rdx, args.GetArgumentOperand(2));  // thisArgument
+    __ movq(rdx, args[2]);  // thisArgument
     __ cmpq(rax, Immediate(3));
     __ j(below, &done, Label::kNear);
-    __ movq(rbx, args.GetArgumentOperand(3));  // argumentsList
+    __ movq(rbx, args[3]);  // argumentsList
     __ bind(&done);
     __ PopReturnAddressTo(rcx);
     __ leaq(rsp,
@@ -1712,10 +1892,11 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax     : argc
   //  -- rsp[0]  : return address
-  //  -- rsp[8]  : new.target (optional)
-  //  -- rsp[16] : argumentsList
-  //  -- rsp[24] : target
-  //  -- rsp[32] : receiver
+  // The order of args depends on V8_REVERSE_JSARGS
+  //  -- args[0] : receiver
+  //  -- args[1] : target
+  //  -- args[2] : argumentsList
+  //  -- args[3] : new.target (optional)
   // -----------------------------------
 
   // 1. Load target into rdi (if present), argumentsList into rbx (if present),
@@ -1724,19 +1905,19 @@ void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
   // (if present) instead.
   {
     Label done;
-    StackArgumentsAccessor args(rsp, rax);
+    StackArgumentsAccessor args(rax);
     __ LoadRoot(rdi, RootIndex::kUndefinedValue);
     __ movq(rdx, rdi);
     __ movq(rbx, rdi);
     __ cmpq(rax, Immediate(1));
     __ j(below, &done, Label::kNear);
-    __ movq(rdi, args.GetArgumentOperand(1));  // target
+    __ movq(rdi, args[1]);                     // target
     __ movq(rdx, rdi);                         // new.target defaults to target
     __ j(equal, &done, Label::kNear);
-    __ movq(rbx, args.GetArgumentOperand(2));  // argumentsList
+    __ movq(rbx, args[2]);  // argumentsList
     __ cmpq(rax, Immediate(3));
     __ j(below, &done, Label::kNear);
-    __ movq(rdx, args.GetArgumentOperand(3));  // new.target
+    __ movq(rdx, args[3]);  // new.target
     __ bind(&done);
     __ PopReturnAddressTo(rcx);
     __ leaq(rsp,
@@ -1809,14 +1990,18 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // -----------------------------------
 
   Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
-  __ cmpq(rbx, Immediate(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+  __ cmpq(rbx, Immediate(kDontAdaptArgumentsSentinel));
   __ j(equal, &dont_adapt_arguments);
   __ LoadTaggedPointerField(
       rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+
+#ifndef V8_REVERSE_JSARGS
+  // This optimization is disabled when the arguments are reversed.
   __ testl(
       FieldOperand(rcx, SharedFunctionInfo::kFlagsOffset),
       Immediate(SharedFunctionInfo::IsSafeToSkipArgumentsAdaptorBit::kMask));
   __ j(not_zero, &skip_adapt_arguments);
+#endif
 
   // -------------------------------------------
   // Adapt arguments.
@@ -1834,7 +2019,11 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     {
       // Copy receiver and all expected arguments.
       const int offset = StandardFrameConstants::kCallerSPOffset;
+#ifdef V8_REVERSE_JSARGS
+      __ leaq(r8, Operand(rbp, rbx, times_system_pointer_size, offset));
+#else
       __ leaq(r8, Operand(rbp, rax, times_system_pointer_size, offset));
+#endif
       __ Set(rax, -1);  // account for receiver
 
       Label copy;
@@ -1850,6 +2039,17 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     // Too few parameters: Actual < expected.
     __ bind(&under_application);
     {
+#ifdef V8_REVERSE_JSARGS
+      // Fill remaining expected arguments with undefined values.
+      Label fill;
+      __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
+      __ movq(r8, rbx);
+      __ subq(r8, rax);
+      __ bind(&fill);
+      __ Push(kScratchRegister);
+      __ decq(r8);
+      __ j(greater, &fill);
+
       // Copy receiver and all actual arguments.
       const int offset = StandardFrameConstants::kCallerSPOffset;
       __ leaq(r9, Operand(rbp, rax, times_system_pointer_size, offset));
@@ -1863,6 +2063,22 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
       __ cmpq(r8, rax);
       __ j(less, &copy);
 
+      // Update actual number of arguments.
+      __ movq(rax, rbx);
+#else   // !V8_REVERSE_JSARGS
+        // Copy receiver and all actual arguments.
+      const int offset = StandardFrameConstants::kCallerSPOffset;
+      __ leaq(r9, Operand(rbp, rax, times_system_pointer_size, offset));
+      __ Set(r8, -1);  // account for receiver
+
+      Label copy;
+      __ bind(&copy);
+      __ incq(r8);
+      __ Push(Operand(r9, 0));
+      __ subq(r9, Immediate(kSystemPointerSize));
+      __ cmpq(r8, rax);
+      __ j(less, &copy);
+
       // Fill remaining expected arguments with undefined values.
       Label fill;
       __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
@@ -1871,6 +2087,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
       __ Push(kScratchRegister);
       __ cmpq(rax, rbx);
       __ j(less, &fill);
+#endif  // !V8_REVERSE_JSARGS
     }
 
     // Call the entry point.
@@ -1981,6 +2198,56 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
   Generate_StackOverflowCheck(masm, rcx, r8, &stack_overflow, Label::kNear);
 
   // Push additional arguments onto the stack.
+#ifdef V8_REVERSE_JSARGS
+  // Move the arguments already in the stack,
+  // including the receiver and the return address.
+  {
+    Label copy, check;
+    Register src = r8, dest = rsp, num = r9, current = r11;
+    __ movq(src, rsp);
+    __ movq(kScratchRegister, rcx);
+    __ negq(kScratchRegister);
+    __ leaq(rsp, Operand(rsp, kScratchRegister, times_system_pointer_size,
+                         0));       // Update stack pointer.
+    __ leaq(num, Operand(rax, 2));  // Number of words to copy.
+                                    // +2 for receiver and return address.
+    __ Set(current, 0);
+    __ jmp(&check);
+    __ bind(&copy);
+    __ movq(kScratchRegister,
+            Operand(src, current, times_system_pointer_size, 0));
+    __ movq(Operand(dest, current, times_system_pointer_size, 0),
+            kScratchRegister);
+    __ incq(current);
+    __ bind(&check);
+    __ cmpq(current, num);
+    __ j(less, &copy);
+    __ leaq(r8, Operand(rsp, num, times_system_pointer_size, 0));
+  }
+
+  // Copy the additional arguments onto the stack.
+  {
+    Register value = scratch;
+    Register src = rbx, dest = r8, num = rcx, current = r9;
+    __ Set(current, 0);
+    Label done, push, loop;
+    __ bind(&loop);
+    __ cmpl(current, num);
+    __ j(equal, &done, Label::kNear);
+    // Turn the hole into undefined as we go.
+    __ LoadAnyTaggedField(value, FieldOperand(src, current, times_tagged_size,
+                                              FixedArray::kHeaderSize));
+    __ CompareRoot(value, RootIndex::kTheHoleValue);
+    __ j(not_equal, &push, Label::kNear);
+    __ LoadRoot(value, RootIndex::kUndefinedValue);
+    __ bind(&push);
+    __ movq(Operand(dest, current, times_system_pointer_size, 0), value);
+    __ incl(current);
+    __ jmp(&loop);
+    __ bind(&done);
+    __ addq(rax, current);
+  }
+#else  // !V8_REVERSE_JSARGS
   {
     Register value = scratch;
     __ PopReturnAddressTo(r8);
@@ -2003,6 +2270,7 @@ void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
     __ PushReturnAddressFrom(r8);
     __ addq(rax, r9);
   }
+#endif
 
   // Tail-call to the actual Call or Construct builtin.
   __ Jump(code, RelocInfo::CODE_TARGET);
@@ -2076,9 +2344,9 @@ void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
       __ PopReturnAddressTo(rcx);
       __ bind(&loop);
       {
-        StackArgumentsAccessor args(rbx, r8, ARGUMENTS_DONT_CONTAIN_RECEIVER);
-        __ Push(args.GetArgumentOperand(0));
         __ decl(r8);
+        __ Push(Operand(rbx, r8, times_system_pointer_size,
+                        kFPOnStackSize + kPCOnStackSize));
         __ j(not_zero, &loop);
       }
       __ PushReturnAddressFrom(rcx);
@@ -2101,7 +2369,7 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm,
   //  -- rdi : the function to call (checked to be a JSFunction)
   // -----------------------------------
 
-  StackArgumentsAccessor args(rsp, rax);
+  StackArgumentsAccessor args(rax);
   __ AssertFunction(rdi);
 
   // ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
@@ -2233,6 +2501,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     //  -- rbx : the number of [[BoundArguments]] (checked to be non-zero)
     // -----------------------------------
 
+    // TODO(victor): Use Generate_StackOverflowCheck here.
     // Check the stack for overflow.
     {
       Label done;
@@ -2242,7 +2511,8 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
 
       // We are not trying to catch interruptions (i.e. debug break and
       // preemption) here, so check the "real stack limit".
-      __ cmpq(kScratchRegister, RealStackLimitAsOperand(masm));
+      __ cmpq(kScratchRegister,
+              StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
       __ j(above_equal, &done, Label::kNear);
       {
         FrameScope scope(masm, StackFrame::MANUAL);
@@ -2252,6 +2522,35 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       __ bind(&done);
     }
 
+#ifdef V8_REVERSE_JSARGS
+    // Save Return Address and Receiver into registers.
+    __ Pop(r8);
+    __ Pop(r10);
+
+    // Push [[BoundArguments]] to the stack.
+    {
+      Label loop;
+      __ LoadTaggedPointerField(
+          rcx, FieldOperand(rdi, JSBoundFunction::kBoundArgumentsOffset));
+      __ SmiUntagField(rbx, FieldOperand(rcx, FixedArray::kLengthOffset));
+      __ addq(rax, rbx);  // Adjust effective number of arguments.
+      __ bind(&loop);
+      // Instead of doing decl(rbx) here subtract kTaggedSize from the header
+      // offset in order to be able to move decl(rbx) right before the loop
+      // condition. This is necessary in order to avoid flags corruption by
+      // pointer decompression code.
+      __ LoadAnyTaggedField(
+          r12, FieldOperand(rcx, rbx, times_tagged_size,
+                            FixedArray::kHeaderSize - kTaggedSize));
+      __ Push(r12);
+      __ decl(rbx);
+      __ j(greater, &loop);
+    }
+
+    // Recover Receiver and Return Address.
+    __ Push(r10);
+    __ Push(r8);
+#else   // !V8_REVERSE_JSARGS
     // Reserve stack space for the [[BoundArguments]].
     __ movq(kScratchRegister, rbx);
     __ AllocateStackSpace(kScratchRegister);
@@ -2282,7 +2581,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
       __ SmiUntagField(rbx, FieldOperand(rcx, FixedArray::kLengthOffset));
       __ bind(&loop);
       // Instead of doing decl(rbx) here subtract kTaggedSize from the header
-      // offset in order to move be able to move decl(rbx) right before the loop
+      // offset in order be able to move decl(rbx) right before the loop
       // condition. This is necessary in order to avoid flags corruption by
       // pointer decompression code.
       __ LoadAnyTaggedField(
@@ -2298,6 +2597,7 @@ void Generate_PushBoundArguments(MacroAssembler* masm) {
     // arguments from the call plus return address plus the number of
     // [[BoundArguments]]), so we need to subtract one for the return address.
     __ decl(rax);
+#endif  // !V8_REVERSE_JSARGS
   }
   __ bind(&no_bound_arguments);
 }
@@ -2313,7 +2613,7 @@ void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
   __ AssertBoundFunction(rdi);
 
   // Patch the receiver to [[BoundThis]].
-  StackArgumentsAccessor args(rsp, rax);
+  StackArgumentsAccessor args(rax);
   __ LoadAnyTaggedField(rbx,
                         FieldOperand(rdi, JSBoundFunction::kBoundThisOffset));
   __ movq(args.GetReceiverOperand(), rbx);
@@ -2334,7 +2634,7 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
   //  -- rax : the number of arguments (not including the receiver)
   //  -- rdi : the target to call (can be any Object)
   // -----------------------------------
-  StackArgumentsAccessor args(rsp, rax);
+  StackArgumentsAccessor args(rax);
 
   Label non_callable;
   __ JumpIfSmi(rdi, &non_callable);
@@ -2439,7 +2739,7 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
   //           the JSFunction on which new was invoked initially)
   //  -- rdi : the constructor to call (can be any Object)
   // -----------------------------------
-  StackArgumentsAccessor args(rsp, rax);
+  StackArgumentsAccessor args(rax);
 
   // Check if target is a Smi.
   Label non_constructor;
@@ -2549,7 +2849,7 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
       offset += kSimd128Size;
     }
 
-    // Push the WASM instance as an explicit argument to WasmCompileLazy.
+    // Push the Wasm instance as an explicit argument to WasmCompileLazy.
     __ Push(kWasmInstanceRegister);
     // Push the function index as second argument.
     __ Push(r11);
@@ -2575,6 +2875,49 @@ void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
   __ jmp(r11);
 }
 
+void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
+  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
+  {
+    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
+
+    // Save all parameter registers. They might hold live values, we restore
+    // them after the runtime call.
+    for (int reg_code : base::bits::IterateBitsBackwards(
+             WasmDebugBreakFrameConstants::kPushedGpRegs)) {
+      __ Push(Register::from_code(reg_code));
+    }
+
+    constexpr int kFpStackSize =
+        kSimd128Size * WasmDebugBreakFrameConstants::kNumPushedFpRegisters;
+    __ AllocateStackSpace(kFpStackSize);
+    int offset = kFpStackSize;
+    for (int reg_code : base::bits::IterateBitsBackwards(
+             WasmDebugBreakFrameConstants::kPushedFpRegs)) {
+      offset -= kSimd128Size;
+      __ movdqu(Operand(rsp, offset), DoubleRegister::from_code(reg_code));
+    }
+
+    // Initialize the JavaScript context with 0. CEntry will use it to
+    // set the current context on the isolate.
+    __ Move(kContextRegister, Smi::zero());
+    __ CallRuntime(Runtime::kWasmDebugBreak, 0);
+
+    // Restore registers.
+    for (int reg_code :
+         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedFpRegs)) {
+      __ movdqu(DoubleRegister::from_code(reg_code), Operand(rsp, offset));
+      offset += kSimd128Size;
+    }
+    __ addq(rsp, Immediate(kFpStackSize));
+    for (int reg_code :
+         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedGpRegs)) {
+      __ Pop(Register::from_code(reg_code));
+    }
+  }
+
+  __ ret(0);
+}
+
 void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                bool builtin_exit_frame) {
@@ -2979,11 +3322,12 @@ void Builtins::Generate_CallApiCallback(MacroAssembler* masm) {
   //  -- rbx                 : call data
   //  -- rdi                 : holder
   //  -- rsp[0]              : return address
-  //  -- rsp[8]              : last argument
+  //  -- rsp[8]              : argument argc
   //  -- ...
-  //  -- rsp[argc * 8]       : first argument
-  //  -- rsp[(argc + 1) * 8] : receiver
+  //  -- rsp[argc * 8]       : argument 1
+  //  -- rsp[(argc + 1) * 8] : argument 0 (receiver)
   // -----------------------------------
+  // NOTE: The order of args are reversed if V8_REVERSE_JSARGS
 
   Register api_function_address = rdx;
   Register argc = rcx;
@@ -3042,8 +3386,13 @@ void Builtins::Generate_CallApiCallback(MacroAssembler* masm) {
 
   // FunctionCallbackInfo::values_ (points at the first varargs argument passed
   // on the stack).
+#ifdef V8_REVERSE_JSARGS
+  __ leaq(scratch,
+          Operand(scratch, (FCA::kArgsLength + 1) * kSystemPointerSize));
+#else
   __ leaq(scratch, Operand(scratch, argc, times_system_pointer_size,
                            (FCA::kArgsLength - 1) * kSystemPointerSize));
+#endif
   __ movq(StackSpaceOperand(1), scratch);
 
   // FunctionCallbackInfo::length_.
diff --git a/deps/v8/src/codegen/OWNERS b/deps/v8/src/codegen/OWNERS
index 8846258784..7b3ad8d1e0 100644
--- a/deps/v8/src/codegen/OWNERS
+++ b/deps/v8/src/codegen/OWNERS
@@ -1,6 +1,7 @@
 bbudge@chromium.org
 bmeurer@chromium.org
 clemensb@chromium.org
+delphick@chromium.org
 gdeepti@chromium.org
 ishell@chromium.org
 jarin@chromium.org
@@ -12,6 +13,7 @@ mvstanton@chromium.org
 neis@chromium.org
 rmcilroy@chromium.org
 sigurds@chromium.org
+solanes@chromium.org
 tebbi@chromium.org
 titzer@chromium.org
 mythria@chromium.org
diff --git a/deps/v8/src/codegen/arm/macro-assembler-arm.cc b/deps/v8/src/codegen/arm/macro-assembler-arm.cc
index 46ad405489..349c8dc29e 100644
--- a/deps/v8/src/codegen/arm/macro-assembler-arm.cc
+++ b/deps/v8/src/codegen/arm/macro-assembler-arm.cc
@@ -852,13 +852,6 @@ void TurboAssembler::PushStandardFrame(Register function_reg) {
   add(fp, sp, Operand(offset));
 }
 
-int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
-  // The registers are pushed starting with the highest encoding,
-  // which means that lowest encodings are closest to the stack pointer.
-  DCHECK(reg_code >= 0 && reg_code < kNumSafepointRegisters);
-  return reg_code;
-}
-
 void TurboAssembler::VFPCanonicalizeNaN(const DwVfpRegister dst,
                                         const DwVfpRegister src,
                                         const Condition cond) {
@@ -2373,15 +2366,25 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    Register scratch = r4;
-    Push(scratch);
+  Register addr_scratch = r4;
+  // See x64 code for reasoning about how to address the isolate data fields.
+  if (root_array_available()) {
+    str(pc,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_pc_offset()));
+    str(fp,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Push(addr_scratch);
+
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_pc_address(isolate()));
+    str(pc, MemOperand(addr_scratch));
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    str(fp, MemOperand(addr_scratch));
 
-    Move(scratch, ExternalReference::fast_c_call_caller_pc_address(isolate()));
-    str(pc, MemOperand(scratch));
-    Move(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    str(fp, MemOperand(scratch));
-    Pop(scratch);
+    Pop(addr_scratch);
   }
 
   // Just call directly. The function called cannot cause a GC, or
@@ -2389,19 +2392,25 @@ void TurboAssembler::CallCFunctionHelper(Register function,
   // stays correct.
   Call(function);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
-    Register scratch1 = r4;
-    Register scratch2 = r5;
-    Push(scratch1);
-    Push(scratch2);
-    Move(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    mov(scratch2, Operand::Zero());
-    str(scratch2, MemOperand(scratch1));
-    Pop(scratch2);
-    Pop(scratch1);
+  // We don't unset the PC; the FP is the source of truth.
+  Register zero_scratch = r5;
+  Push(zero_scratch);
+  mov(zero_scratch, Operand::Zero());
+
+  if (root_array_available()) {
+    str(zero_scratch,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Push(addr_scratch);
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    str(zero_scratch, MemOperand(addr_scratch));
+    Pop(addr_scratch);
   }
 
+  Pop(zero_scratch);
+
   int stack_passed_arguments =
       CalculateStackPassedWords(num_reg_arguments, num_double_arguments);
   if (ActivationFrameAlignment() > kPointerSize) {
@@ -2452,7 +2461,9 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
   mov(kSpeculationPoisonRegister, Operand(-1));
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
 
   // Save the deopt id in r10 (we don't need the roots array from now on).
@@ -2473,6 +2484,7 @@ void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
 }
 
 void TurboAssembler::Trap() { stop(); }
+void TurboAssembler::DebugBreak() { stop(); }
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/codegen/arm/macro-assembler-arm.h b/deps/v8/src/codegen/arm/macro-assembler-arm.h
index d0d9b1c655..9ec1bafb58 100644
--- a/deps/v8/src/codegen/arm/macro-assembler-arm.h
+++ b/deps/v8/src/codegen/arm/macro-assembler-arm.h
@@ -254,6 +254,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void MovFromFloatResult(DwVfpRegister dst);
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Calls Abort(msg) if the condition cond is not satisfied.
   // Use --debug-code to enable.
@@ -315,7 +316,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   // This should only be used when assembling a deoptimizer call because of
   // the CheckConstPool invocation, which is only needed for deoptimization.
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   // Emit code to discard a non-negative number of pointer-sized elements
   // from the stack, clobbering only the sp register.
@@ -531,6 +533,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void ResetSpeculationPoisonRegister();
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
  private:
   // Compare single values and then load the fpscr flags to a register.
   void VFPCompareAndLoadFlags(const SwVfpRegister src1,
@@ -799,13 +811,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
                       Register actual_parameter_count, Label* done,
                       InvokeFlag flag);
 
-  // Compute memory operands for safepoint stack slots.
-  static int SafepointRegisterStackIndex(int reg_code);
-
-  // Needs access to SafepointRegisterStackIndex for compiled frame
-  // traversal.
-  friend class StandardFrame;
-
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
 
diff --git a/deps/v8/src/codegen/arm/register-arm.h b/deps/v8/src/codegen/arm/register-arm.h
index 2130bdf0a4..0d453ec03e 100644
--- a/deps/v8/src/codegen/arm/register-arm.h
+++ b/deps/v8/src/codegen/arm/register-arm.h
@@ -63,7 +63,6 @@ const int kR9Available = 1;  // 1 if available to us, 0 if reserved
 
 // Register list in load/store instructions
 // Note that the bit values must match those used in actual instruction encoding
-const int kNumRegs = 16;
 
 // Caller-saved/arguments registers
 const RegList kJSCallerSaved = 1 << 0 |  // r0 a1
@@ -96,17 +95,6 @@ const int kNumCalleeSaved = 7 + kR9Available;
 // Double registers d8 to d15 are callee-saved.
 const int kNumDoubleCalleeSaved = 8;
 
-// Number of registers for which space is reserved in safepoints. Must be a
-// multiple of 8.
-// TODO(regis): Only 8 registers may actually be sufficient. Revisit.
-const int kNumSafepointRegisters = 16;
-
-// Define the list of registers actually saved at safepoints.
-// Note that the number of saved registers may be smaller than the reserved
-// space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
-const RegList kSafepointSavedRegisters = kJSCallerSaved | kCalleeSaved;
-const int kNumSafepointSavedRegisters = kNumJSCallerSaved + kNumCalleeSaved;
-
 enum RegisterCode {
 #define REGISTER_CODE(R) kRegCode_##R,
   GENERAL_REGISTERS(REGISTER_CODE)
diff --git a/deps/v8/src/codegen/arm64/assembler-arm64-inl.h b/deps/v8/src/codegen/arm64/assembler-arm64-inl.h
index 8416defe3c..f3c3e55975 100644
--- a/deps/v8/src/codegen/arm64/assembler-arm64-inl.h
+++ b/deps/v8/src/codegen/arm64/assembler-arm64-inl.h
@@ -463,19 +463,6 @@ bool MemOperand::IsPreIndex() const { return addrmode_ == PreIndex; }
 
 bool MemOperand::IsPostIndex() const { return addrmode_ == PostIndex; }
 
-Operand MemOperand::OffsetAsOperand() const {
-  if (IsImmediateOffset()) {
-    return offset();
-  } else {
-    DCHECK(IsRegisterOffset());
-    if (extend() == NO_EXTEND) {
-      return Operand(regoffset(), shift(), shift_amount());
-    } else {
-      return Operand(regoffset(), extend(), shift_amount());
-    }
-  }
-}
-
 void Assembler::Unreachable() { debug("UNREACHABLE", __LINE__, BREAK); }
 
 Address Assembler::target_pointer_address_at(Address pc) {
diff --git a/deps/v8/src/codegen/arm64/assembler-arm64.cc b/deps/v8/src/codegen/arm64/assembler-arm64.cc
index c3bae988f6..d5a0295934 100644
--- a/deps/v8/src/codegen/arm64/assembler-arm64.cc
+++ b/deps/v8/src/codegen/arm64/assembler-arm64.cc
@@ -83,18 +83,6 @@ CPURegister CPURegList::PopHighestIndex() {
   return CPURegister::Create(index, size_, type_);
 }
 
-void CPURegList::RemoveCalleeSaved() {
-  if (type() == CPURegister::kRegister) {
-    Remove(GetCalleeSaved(RegisterSizeInBits()));
-  } else if (type() == CPURegister::kVRegister) {
-    Remove(GetCalleeSavedV(RegisterSizeInBits()));
-  } else {
-    DCHECK_EQ(type(), CPURegister::kNoRegister);
-    DCHECK(IsEmpty());
-    // The list must already be empty, so do nothing.
-  }
-}
-
 void CPURegList::Align() {
   // Use padreg, if necessary, to maintain stack alignment.
   if (Count() % 2 != 0) {
@@ -109,7 +97,7 @@ void CPURegList::Align() {
 }
 
 CPURegList CPURegList::GetCalleeSaved(int size) {
-  return CPURegList(CPURegister::kRegister, size, 19, 29);
+  return CPURegList(CPURegister::kRegister, size, 19, 28);
 }
 
 CPURegList CPURegList::GetCalleeSavedV(int size) {
@@ -118,9 +106,8 @@ CPURegList CPURegList::GetCalleeSavedV(int size) {
 
 CPURegList CPURegList::GetCallerSaved(int size) {
   // x18 is the platform register and is reserved for the use of platform ABIs.
-  // Registers x0-x17 and lr (x30) are caller-saved.
+  // Registers x0-x17 are caller-saved.
   CPURegList list = CPURegList(CPURegister::kRegister, size, 0, 17);
-  list.Combine(lr);
   return list;
 }
 
@@ -131,34 +118,6 @@ CPURegList CPURegList::GetCallerSavedV(int size) {
   return list;
 }
 
-// This function defines the list of registers which are associated with a
-// safepoint slot. Safepoint register slots are saved contiguously on the stack.
-// MacroAssembler::SafepointRegisterStackIndex handles mapping from register
-// code to index in the safepoint register slots. Any change here can affect
-// this mapping.
-CPURegList CPURegList::GetSafepointSavedRegisters() {
-  CPURegList list = CPURegList::GetCalleeSaved();
-  list.Combine(
-      CPURegList(CPURegister::kRegister, kXRegSizeInBits, kJSCallerSaved));
-
-  // Note that unfortunately we can't use symbolic names for registers and have
-  // to directly use register codes. This is because this function is used to
-  // initialize some static variables and we can't rely on register variables
-  // to be initialized due to static initialization order issues in C++.
-
-  // Drop ip0 and ip1 (i.e. x16 and x17), as they should not be expected to be
-  // preserved outside of the macro assembler.
-  list.Remove(16);
-  list.Remove(17);
-
-  // x18 is the platform register and is reserved for the use of platform ABIs.
-
-  // Add the link register (x30) to the safepoint list.
-  list.Combine(30);
-
-  return list;
-}
-
 // -----------------------------------------------------------------------------
 // Implementation of RelocInfo
 
@@ -292,31 +251,6 @@ bool Operand::NeedsRelocation(const Assembler* assembler) const {
   return !RelocInfo::IsNone(rmode);
 }
 
-MemOperand::PairResult MemOperand::AreConsistentForPair(
-    const MemOperand& operandA, const MemOperand& operandB,
-    int access_size_log2) {
-  DCHECK_GE(access_size_log2, 0);
-  DCHECK_LE(access_size_log2, 3);
-  // Step one: check that they share the same base, that the mode is Offset
-  // and that the offset is a multiple of access size.
-  if (operandA.base() != operandB.base() || (operandA.addrmode() != Offset) ||
-      (operandB.addrmode() != Offset) ||
-      ((operandA.offset() & ((1 << access_size_log2) - 1)) != 0)) {
-    return kNotPair;
-  }
-  // Step two: check that the offsets are contiguous and that the range
-  // is OK for ldp/stp.
-  if ((operandB.offset() == operandA.offset() + (1LL << access_size_log2)) &&
-      is_int7(operandA.offset() >> access_size_log2)) {
-    return kPairAB;
-  }
-  if ((operandA.offset() == operandB.offset() + (1LL << access_size_log2)) &&
-      is_int7(operandB.offset() >> access_size_log2)) {
-    return kPairBA;
-  }
-  return kNotPair;
-}
-
 // Assembler
 Assembler::Assembler(const AssemblerOptions& options,
                      std::unique_ptr<AssemblerBuffer> buffer)
@@ -1184,6 +1118,30 @@ void Assembler::autia1716() { Emit(AUTIA1716); }
 void Assembler::paciasp() { Emit(PACIASP); }
 void Assembler::autiasp() { Emit(AUTIASP); }
 
+void Assembler::bti(BranchTargetIdentifier id) {
+  SystemHint op;
+  switch (id) {
+    case BranchTargetIdentifier::kBti:
+      op = BTI;
+      break;
+    case BranchTargetIdentifier::kBtiCall:
+      op = BTI_c;
+      break;
+    case BranchTargetIdentifier::kBtiJump:
+      op = BTI_j;
+      break;
+    case BranchTargetIdentifier::kBtiJumpCall:
+      op = BTI_jc;
+      break;
+    case BranchTargetIdentifier::kNone:
+    case BranchTargetIdentifier::kPaciasp:
+      // We always want to generate a BTI instruction here, so disallow
+      // skipping its generation or generating a PACIASP instead.
+      UNREACHABLE();
+  }
+  hint(op);
+}
+
 void Assembler::ldp(const CPURegister& rt, const CPURegister& rt2,
                     const MemOperand& src) {
   LoadStorePair(rt, rt2, src, LoadPairOpFor(rt, rt2));
diff --git a/deps/v8/src/codegen/arm64/assembler-arm64.h b/deps/v8/src/codegen/arm64/assembler-arm64.h
index 04fbaf3fb0..a9e8a5e85a 100644
--- a/deps/v8/src/codegen/arm64/assembler-arm64.h
+++ b/deps/v8/src/codegen/arm64/assembler-arm64.h
@@ -154,20 +154,6 @@ class MemOperand {
   inline bool IsPreIndex() const;
   inline bool IsPostIndex() const;
 
-  // For offset modes, return the offset as an Operand. This helper cannot
-  // handle indexed modes.
-  inline Operand OffsetAsOperand() const;
-
-  enum PairResult {
-    kNotPair,  // Can't use a pair instruction.
-    kPairAB,   // Can use a pair instruction (operandA has lower address).
-    kPairBA    // Can use a pair instruction (operandB has lower address).
-  };
-  // Check if two MemOperand are consistent for stp/ldp use.
-  static PairResult AreConsistentForPair(const MemOperand& operandA,
-                                         const MemOperand& operandB,
-                                         int access_size_log2 = kXRegSizeLog2);
-
  private:
   Register base_;
   Register regoffset_;
@@ -953,7 +939,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Conditional speculation barrier.
   void csdb();
 
-  // Alias for system instructions.
+  // Branch target identification.
+  void bti(BranchTargetIdentifier id);
+
+  // No-op.
   void nop() { hint(NOP); }
 
   // Different nop operations are used by the code generator to detect certain
diff --git a/deps/v8/src/codegen/arm64/constants-arm64.h b/deps/v8/src/codegen/arm64/constants-arm64.h
index ccafae5e14..e63962993a 100644
--- a/deps/v8/src/codegen/arm64/constants-arm64.h
+++ b/deps/v8/src/codegen/arm64/constants-arm64.h
@@ -38,14 +38,10 @@ constexpr int kMaxLoadLiteralRange = 1 * MB;
 
 const int kNumberOfRegisters = 32;
 const int kNumberOfVRegisters = 32;
-// Callee saved registers are x19-x30(lr).
-const int kNumberOfCalleeSavedRegisters = 11;
-const int kFirstCalleeSavedRegisterIndex = 19;
+// Callee saved registers are x19-x28.
+const int kNumberOfCalleeSavedRegisters = 10;
 // Callee saved FP registers are d8-d15.
 const int kNumberOfCalleeSavedVRegisters = 8;
-const int kFirstCalleeSavedVRegisterIndex = 8;
-// Callee saved registers with no specific purpose in JS are x19-x25.
-const size_t kJSCalleeSavedRegList = 0x03f80000;
 const int kWRegSizeInBits = 32;
 const int kWRegSizeInBitsLog2 = 5;
 const int kWRegSize = kWRegSizeInBits >> 3;
@@ -389,7 +385,36 @@ enum SystemHint {
   WFI = 3,
   SEV = 4,
   SEVL = 5,
-  CSDB = 20
+  CSDB = 20,
+  BTI = 32,
+  BTI_c = 34,
+  BTI_j = 36,
+  BTI_jc = 38
+};
+
+// In a guarded page, only BTI and PACI[AB]SP instructions are allowed to be
+// the target of indirect branches. Details on which kinds of branches each
+// instruction allows follow in the comments below:
+enum class BranchTargetIdentifier {
+  // Do not emit a BTI instruction.
+  kNone,
+
+  // Emit a BTI instruction. Cannot be the target of indirect jumps/calls.
+  kBti,
+
+  // Emit a "BTI c" instruction. Can be the target of indirect jumps (BR) with
+  // x16/x17 as the target register, or indirect calls (BLR).
+  kBtiCall,
+
+  // Emit a "BTI j" instruction. Can be the target of indirect jumps (BR).
+  kBtiJump,
+
+  // Emit a "BTI jc" instruction, which is a combination of "BTI j" and "BTI c".
+  kBtiJumpCall,
+
+  // Emit a PACIASP instruction, which acts like a "BTI c" or a "BTI jc", based
+  // on the value of SCTLR_EL1.BT0.
+  kPaciasp
 };
 
 enum BarrierDomain {
diff --git a/deps/v8/src/codegen/arm64/instructions-arm64.cc b/deps/v8/src/codegen/arm64/instructions-arm64.cc
index ab022affdd..c2224ffe34 100644
--- a/deps/v8/src/codegen/arm64/instructions-arm64.cc
+++ b/deps/v8/src/codegen/arm64/instructions-arm64.cc
@@ -310,28 +310,6 @@ void Instruction::SetImmLLiteral(Instruction* source) {
   SetInstructionBits(Mask(~mask) | imm);
 }
 
-// TODO(jbramley): We can't put this inline in the class because things like
-// xzr and Register are not defined in that header. Consider adding
-// instructions-arm64-inl.h to work around this.
-bool InstructionSequence::IsInlineData() const {
-  // Inline data is encoded as a single movz instruction which writes to xzr
-  // (x31).
-  return IsMovz() && SixtyFourBits() && (Rd() == kZeroRegCode);
-  // TODO(all): If we extend ::InlineData() to support bigger data, we need
-  // to update this method too.
-}
-
-// TODO(jbramley): We can't put this inline in the class because things like
-// xzr and Register are not defined in that header. Consider adding
-// instructions-arm64-inl.h to work around this.
-uint64_t InstructionSequence::InlineData() const {
-  DCHECK(IsInlineData());
-  uint64_t payload = ImmMoveWide();
-  // TODO(all): If we extend ::InlineData() to support bigger data, we need
-  // to update this method too.
-  return payload;
-}
-
 NEONFormatDecoder::NEONFormatDecoder(const Instruction* instr) {
   instrbits_ = instr->InstructionBits();
   SetFormatMaps(IntegerFormatMap());
diff --git a/deps/v8/src/codegen/arm64/instructions-arm64.h b/deps/v8/src/codegen/arm64/instructions-arm64.h
index 7fe732e2ba..d2341b972f 100644
--- a/deps/v8/src/codegen/arm64/instructions-arm64.h
+++ b/deps/v8/src/codegen/arm64/instructions-arm64.h
@@ -379,6 +379,24 @@ class Instruction {
            (Mask(MoveWideImmediateMask) == MOVN_w);
   }
 
+  bool IsException() const { return Mask(ExceptionFMask) == ExceptionFixed; }
+
+  bool IsPAuth() const { return Mask(SystemPAuthFMask) == SystemPAuthFixed; }
+
+  bool IsBti() const {
+    if (Mask(SystemHintFMask) == SystemHintFixed) {
+      int imm_hint = ImmHint();
+      switch (imm_hint) {
+        case BTI:
+        case BTI_c:
+        case BTI_j:
+        case BTI_jc:
+          return true;
+      }
+    }
+    return false;
+  }
+
   bool IsNop(int n) {
     // A marking nop is an instruction
     //   mov r<n>,  r<n>
@@ -445,20 +463,6 @@ class Instruction {
   void SetBranchImmTarget(Instruction* target);
 };
 
-// Where Instruction looks at instructions generated by the Assembler,
-// InstructionSequence looks at instructions sequences generated by the
-// MacroAssembler.
-class InstructionSequence : public Instruction {
- public:
-  static InstructionSequence* At(Address address) {
-    return reinterpret_cast<InstructionSequence*>(address);
-  }
-
-  // Sequences generated by MacroAssembler::InlineData().
-  bool IsInlineData() const;
-  uint64_t InlineData() const;
-};
-
 // Simulator/Debugger debug instructions ---------------------------------------
 // Each debug marker is represented by a HLT instruction. The immediate comment
 // field in the instruction is used to identify the type of debug marker. Each
diff --git a/deps/v8/src/codegen/arm64/macro-assembler-arm64-inl.h b/deps/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
index aa2df90d0f..809838bcf9 100644
--- a/deps/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
+++ b/deps/v8/src/codegen/arm64/macro-assembler-arm64-inl.h
@@ -309,9 +309,71 @@ void MacroAssembler::Bfxil(const Register& rd, const Register& rn, unsigned lsb,
   bfxil(rd, rn, lsb, width);
 }
 
-void TurboAssembler::Bind(Label* label) {
+void TurboAssembler::Bind(Label* label, BranchTargetIdentifier id) {
   DCHECK(allow_macro_instructions());
-  bind(label);
+  if (id == BranchTargetIdentifier::kNone) {
+    bind(label);
+  } else {
+    // Emit this inside an InstructionAccurateScope to ensure there are no extra
+    // instructions between the bind and the target identifier instruction.
+    InstructionAccurateScope scope(this, 1);
+    bind(label);
+    if (id == BranchTargetIdentifier::kPaciasp) {
+      paciasp();
+    } else {
+      bti(id);
+    }
+  }
+}
+
+void TurboAssembler::CodeEntry() {
+  // Since `kJavaScriptCallCodeStartRegister` is the target register for tail
+  // calls, we have to allow for jumps too, with "BTI jc". We also allow the
+  // register allocator to pick the target register for calls made from
+  // WebAssembly.
+  // TODO(v8:10026): Consider changing this so that we can use CallTarget(),
+  // which maps to "BTI c", here instead.
+  JumpOrCallTarget();
+}
+
+void TurboAssembler::ExceptionHandler() { JumpTarget(); }
+
+void TurboAssembler::BindExceptionHandler(Label* label) {
+  BindJumpTarget(label);
+}
+
+void TurboAssembler::JumpTarget() {
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  bti(BranchTargetIdentifier::kBtiJump);
+#endif
+}
+
+void TurboAssembler::BindJumpTarget(Label* label) {
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Bind(label, BranchTargetIdentifier::kBtiJump);
+#else
+  Bind(label);
+#endif
+}
+
+void TurboAssembler::CallTarget() {
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  bti(BranchTargetIdentifier::kBtiCall);
+#endif
+}
+
+void TurboAssembler::JumpOrCallTarget() {
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  bti(BranchTargetIdentifier::kBtiJumpCall);
+#endif
+}
+
+void TurboAssembler::BindJumpOrCallTarget(Label* label) {
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Bind(label, BranchTargetIdentifier::kBtiJumpCall);
+#else
+  Bind(label);
+#endif
 }
 
 void TurboAssembler::Bl(Label* label) {
@@ -1063,6 +1125,166 @@ void MacroAssembler::JumpIfNotSmi(Register value, Label* not_smi_label) {
 
 void TurboAssembler::jmp(Label* L) { B(L); }
 
+template <TurboAssembler::StoreLRMode lr_mode>
+void TurboAssembler::Push(const CPURegister& src0, const CPURegister& src1,
+                          const CPURegister& src2, const CPURegister& src3) {
+  DCHECK(AreSameSizeAndType(src0, src1, src2, src3));
+  DCHECK_IMPLIES((lr_mode == kSignLR), ((src0 == lr) || (src1 == lr) ||
+                                        (src2 == lr) || (src3 == lr)));
+  DCHECK_IMPLIES((lr_mode == kDontStoreLR), ((src0 != lr) && (src1 != lr) &&
+                                             (src2 != lr) && (src3 != lr)));
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kSignLR) {
+    Paciasp();
+  }
+#endif
+
+  int count = 1 + src1.is_valid() + src2.is_valid() + src3.is_valid();
+  int size = src0.SizeInBytes();
+  DCHECK_EQ(0, (size * count) % 16);
+
+  PushHelper(count, size, src0, src1, src2, src3);
+}
+
+template <TurboAssembler::StoreLRMode lr_mode>
+void TurboAssembler::Push(const Register& src0, const VRegister& src1) {
+  DCHECK_IMPLIES((lr_mode == kSignLR), ((src0 == lr) || (src1 == lr)));
+  DCHECK_IMPLIES((lr_mode == kDontStoreLR), ((src0 != lr) && (src1 != lr)));
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kSignLR) {
+    Paciasp();
+  }
+#endif
+
+  int size = src0.SizeInBytes() + src1.SizeInBytes();
+  DCHECK_EQ(0, size % 16);
+
+  // Reserve room for src0 and push src1.
+  str(src1, MemOperand(sp, -size, PreIndex));
+  // Fill the gap with src0.
+  str(src0, MemOperand(sp, src1.SizeInBytes()));
+}
+
+template <TurboAssembler::LoadLRMode lr_mode>
+void TurboAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
+                         const CPURegister& dst2, const CPURegister& dst3) {
+  // It is not valid to pop into the same register more than once in one
+  // instruction, not even into the zero register.
+  DCHECK(!AreAliased(dst0, dst1, dst2, dst3));
+  DCHECK(AreSameSizeAndType(dst0, dst1, dst2, dst3));
+  DCHECK(dst0.is_valid());
+
+  int count = 1 + dst1.is_valid() + dst2.is_valid() + dst3.is_valid();
+  int size = dst0.SizeInBytes();
+  DCHECK_EQ(0, (size * count) % 16);
+
+  PopHelper(count, size, dst0, dst1, dst2, dst3);
+
+  DCHECK_IMPLIES((lr_mode == kAuthLR), ((dst0 == lr) || (dst1 == lr) ||
+                                        (dst2 == lr) || (dst3 == lr)));
+  DCHECK_IMPLIES((lr_mode == kDontLoadLR), ((dst0 != lr) && (dst1 != lr)) &&
+                                               (dst2 != lr) && (dst3 != lr));
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kAuthLR) {
+    Autiasp();
+  }
+#endif
+}
+
+template <TurboAssembler::StoreLRMode lr_mode>
+void TurboAssembler::Poke(const CPURegister& src, const Operand& offset) {
+  DCHECK_IMPLIES((lr_mode == kSignLR), (src == lr));
+  DCHECK_IMPLIES((lr_mode == kDontStoreLR), (src != lr));
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kSignLR) {
+    Paciasp();
+  }
+#endif
+
+  if (offset.IsImmediate()) {
+    DCHECK_GE(offset.ImmediateValue(), 0);
+  } else if (emit_debug_code()) {
+    Cmp(xzr, offset);
+    Check(le, AbortReason::kStackAccessBelowStackPointer);
+  }
+
+  Str(src, MemOperand(sp, offset));
+}
+
+template <TurboAssembler::LoadLRMode lr_mode>
+void TurboAssembler::Peek(const CPURegister& dst, const Operand& offset) {
+  if (offset.IsImmediate()) {
+    DCHECK_GE(offset.ImmediateValue(), 0);
+  } else if (emit_debug_code()) {
+    Cmp(xzr, offset);
+    Check(le, AbortReason::kStackAccessBelowStackPointer);
+  }
+
+  Ldr(dst, MemOperand(sp, offset));
+
+  DCHECK_IMPLIES((lr_mode == kAuthLR), (dst == lr));
+  DCHECK_IMPLIES((lr_mode == kDontLoadLR), (dst != lr));
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kAuthLR) {
+    Autiasp();
+  }
+#endif
+}
+
+template <TurboAssembler::StoreLRMode lr_mode>
+void TurboAssembler::PushCPURegList(CPURegList registers) {
+  DCHECK_IMPLIES((lr_mode == kDontStoreLR), !registers.IncludesAliasOf(lr));
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kSignLR && registers.IncludesAliasOf(lr)) {
+    Paciasp();
+  }
+#endif
+
+  int size = registers.RegisterSizeInBytes();
+  DCHECK_EQ(0, (size * registers.Count()) % 16);
+
+  // Push up to four registers at a time.
+  while (!registers.IsEmpty()) {
+    int count_before = registers.Count();
+    const CPURegister& src0 = registers.PopHighestIndex();
+    const CPURegister& src1 = registers.PopHighestIndex();
+    const CPURegister& src2 = registers.PopHighestIndex();
+    const CPURegister& src3 = registers.PopHighestIndex();
+    int count = count_before - registers.Count();
+    PushHelper(count, size, src0, src1, src2, src3);
+  }
+}
+
+template <TurboAssembler::LoadLRMode lr_mode>
+void TurboAssembler::PopCPURegList(CPURegList registers) {
+  int size = registers.RegisterSizeInBytes();
+  DCHECK_EQ(0, (size * registers.Count()) % 16);
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  bool contains_lr = registers.IncludesAliasOf(lr);
+  DCHECK_IMPLIES((lr_mode == kDontLoadLR), !contains_lr);
+#endif
+
+  // Pop up to four registers at a time.
+  while (!registers.IsEmpty()) {
+    int count_before = registers.Count();
+    const CPURegister& dst0 = registers.PopLowestIndex();
+    const CPURegister& dst1 = registers.PopLowestIndex();
+    const CPURegister& dst2 = registers.PopLowestIndex();
+    const CPURegister& dst3 = registers.PopLowestIndex();
+    int count = count_before - registers.Count();
+    PopHelper(count, size, dst0, dst1, dst2, dst3);
+  }
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  if (lr_mode == kAuthLR && contains_lr) {
+    Autiasp();
+  }
+#endif
+}
+
 void TurboAssembler::Push(Handle<HeapObject> handle) {
   UseScratchRegisterScope temps(this);
   Register tmp = temps.AcquireX();
@@ -1245,12 +1467,6 @@ void TurboAssembler::TestAndBranchIfAllClear(const Register& reg,
   }
 }
 
-void MacroAssembler::InlineData(uint64_t data) {
-  DCHECK(is_uint16(data));
-  InstructionAccurateScope scope(this, 1);
-  movz(xzr, data);
-}
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/codegen/arm64/macro-assembler-arm64.cc b/deps/v8/src/codegen/arm64/macro-assembler-arm64.cc
index 07e308b48b..1273904c9c 100644
--- a/deps/v8/src/codegen/arm64/macro-assembler-arm64.cc
+++ b/deps/v8/src/codegen/arm64/macro-assembler-arm64.cc
@@ -60,7 +60,7 @@ int TurboAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
   list.Remove(exclusion);
   list.Align();
 
-  PushCPURegList(list);
+  PushCPURegList<kDontStoreLR>(list);
 
   int bytes = list.Count() * kXRegSizeInBits / 8;
 
@@ -84,7 +84,7 @@ int TurboAssembler::PopCallerSaved(SaveFPRegsMode fp_mode, Register exclusion) {
   list.Remove(exclusion);
   list.Align();
 
-  PopCPURegList(list);
+  PopCPURegList<kDontLoadLR>(list);
   bytes += list.Count() * kXRegSizeInBits / 8;
 
   return bytes;
@@ -1046,17 +1046,6 @@ void TurboAssembler::Abs(const Register& rd, const Register& rm,
 // Abstracted stack operations.
 
 void TurboAssembler::Push(const CPURegister& src0, const CPURegister& src1,
-                          const CPURegister& src2, const CPURegister& src3) {
-  DCHECK(AreSameSizeAndType(src0, src1, src2, src3));
-
-  int count = 1 + src1.is_valid() + src2.is_valid() + src3.is_valid();
-  int size = src0.SizeInBytes();
-  DCHECK_EQ(0, (size * count) % 16);
-
-  PushHelper(count, size, src0, src1, src2, src3);
-}
-
-void TurboAssembler::Push(const CPURegister& src0, const CPURegister& src1,
                           const CPURegister& src2, const CPURegister& src3,
                           const CPURegister& src4, const CPURegister& src5,
                           const CPURegister& src6, const CPURegister& src7) {
@@ -1071,21 +1060,6 @@ void TurboAssembler::Push(const CPURegister& src0, const CPURegister& src1,
 }
 
 void TurboAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
-                         const CPURegister& dst2, const CPURegister& dst3) {
-  // It is not valid to pop into the same register more than once in one
-  // instruction, not even into the zero register.
-  DCHECK(!AreAliased(dst0, dst1, dst2, dst3));
-  DCHECK(AreSameSizeAndType(dst0, dst1, dst2, dst3));
-  DCHECK(dst0.is_valid());
-
-  int count = 1 + dst1.is_valid() + dst2.is_valid() + dst3.is_valid();
-  int size = dst0.SizeInBytes();
-  DCHECK_EQ(0, (size * count) % 16);
-
-  PopHelper(count, size, dst0, dst1, dst2, dst3);
-}
-
-void TurboAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
                          const CPURegister& dst2, const CPURegister& dst3,
                          const CPURegister& dst4, const CPURegister& dst5,
                          const CPURegister& dst6, const CPURegister& dst7) {
@@ -1103,48 +1077,6 @@ void TurboAssembler::Pop(const CPURegister& dst0, const CPURegister& dst1,
   PopHelper(count - 4, size, dst4, dst5, dst6, dst7);
 }
 
-void TurboAssembler::Push(const Register& src0, const VRegister& src1) {
-  int size = src0.SizeInBytes() + src1.SizeInBytes();
-  DCHECK_EQ(0, size % 16);
-
-  // Reserve room for src0 and push src1.
-  str(src1, MemOperand(sp, -size, PreIndex));
-  // Fill the gap with src0.
-  str(src0, MemOperand(sp, src1.SizeInBytes()));
-}
-
-void TurboAssembler::PushCPURegList(CPURegList registers) {
-  int size = registers.RegisterSizeInBytes();
-  DCHECK_EQ(0, (size * registers.Count()) % 16);
-
-  // Push up to four registers at a time.
-  while (!registers.IsEmpty()) {
-    int count_before = registers.Count();
-    const CPURegister& src0 = registers.PopHighestIndex();
-    const CPURegister& src1 = registers.PopHighestIndex();
-    const CPURegister& src2 = registers.PopHighestIndex();
-    const CPURegister& src3 = registers.PopHighestIndex();
-    int count = count_before - registers.Count();
-    PushHelper(count, size, src0, src1, src2, src3);
-  }
-}
-
-void TurboAssembler::PopCPURegList(CPURegList registers) {
-  int size = registers.RegisterSizeInBytes();
-  DCHECK_EQ(0, (size * registers.Count()) % 16);
-
-  // Pop up to four registers at a time.
-  while (!registers.IsEmpty()) {
-    int count_before = registers.Count();
-    const CPURegister& dst0 = registers.PopLowestIndex();
-    const CPURegister& dst1 = registers.PopLowestIndex();
-    const CPURegister& dst2 = registers.PopLowestIndex();
-    const CPURegister& dst3 = registers.PopLowestIndex();
-    int count = count_before - registers.Count();
-    PopHelper(count, size, dst0, dst1, dst2, dst3);
-  }
-}
-
 void MacroAssembler::PushMultipleTimes(CPURegister src, Register count) {
   UseScratchRegisterScope temps(this);
   Register temp = temps.AcquireSameSizeAs(count);
@@ -1249,28 +1181,6 @@ void TurboAssembler::PopHelper(int count, int size, const CPURegister& dst0,
   }
 }
 
-void TurboAssembler::Poke(const CPURegister& src, const Operand& offset) {
-  if (offset.IsImmediate()) {
-    DCHECK_GE(offset.ImmediateValue(), 0);
-  } else if (emit_debug_code()) {
-    Cmp(xzr, offset);
-    Check(le, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  Str(src, MemOperand(sp, offset));
-}
-
-void TurboAssembler::Peek(const CPURegister& dst, const Operand& offset) {
-  if (offset.IsImmediate()) {
-    DCHECK_GE(offset.ImmediateValue(), 0);
-  } else if (emit_debug_code()) {
-    Cmp(xzr, offset);
-    Check(le, AbortReason::kStackAccessBelowStackPointer);
-  }
-
-  Ldr(dst, MemOperand(sp, offset));
-}
-
 void TurboAssembler::PokePair(const CPURegister& src1, const CPURegister& src2,
                               int offset) {
   DCHECK(AreSameSizeAndType(src1, src2));
@@ -1286,50 +1196,61 @@ void MacroAssembler::PeekPair(const CPURegister& dst1, const CPURegister& dst2,
 }
 
 void MacroAssembler::PushCalleeSavedRegisters() {
-  // Ensure that the macro-assembler doesn't use any scratch registers.
-  InstructionAccurateScope scope(this);
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Paciasp();
+#endif
 
-  MemOperand tos(sp, -2 * static_cast<int>(kXRegSize), PreIndex);
+  {
+    // Ensure that the macro-assembler doesn't use any scratch registers.
+    InstructionAccurateScope scope(this);
 
-  stp(d14, d15, tos);
-  stp(d12, d13, tos);
-  stp(d10, d11, tos);
-  stp(d8, d9, tos);
+    MemOperand tos(sp, -2 * static_cast<int>(kXRegSize), PreIndex);
 
-  STATIC_ASSERT(
-      EntryFrameConstants::kCalleeSavedRegisterBytesPushedBeforeFpLrPair ==
-      8 * kSystemPointerSize);
+    stp(d14, d15, tos);
+    stp(d12, d13, tos);
+    stp(d10, d11, tos);
+    stp(d8, d9, tos);
 
-  stp(x29, x30, tos);  // fp, lr
+    STATIC_ASSERT(
+        EntryFrameConstants::kCalleeSavedRegisterBytesPushedBeforeFpLrPair ==
+        8 * kSystemPointerSize);
+    stp(x29, x30, tos);  // fp, lr
 
-  STATIC_ASSERT(
-      EntryFrameConstants::kCalleeSavedRegisterBytesPushedAfterFpLrPair ==
-      10 * kSystemPointerSize);
+    STATIC_ASSERT(
+        EntryFrameConstants::kCalleeSavedRegisterBytesPushedAfterFpLrPair ==
+        10 * kSystemPointerSize);
 
-  stp(x27, x28, tos);
-  stp(x25, x26, tos);
-  stp(x23, x24, tos);
-  stp(x21, x22, tos);
-  stp(x19, x20, tos);
+    stp(x27, x28, tos);
+    stp(x25, x26, tos);
+    stp(x23, x24, tos);
+    stp(x21, x22, tos);
+    stp(x19, x20, tos);
+  }
 }
 
 void MacroAssembler::PopCalleeSavedRegisters() {
-  // Ensure that the macro-assembler doesn't use any scratch registers.
-  InstructionAccurateScope scope(this);
+  {
+    // Ensure that the macro-assembler doesn't use any scratch registers.
+    InstructionAccurateScope scope(this);
 
-  MemOperand tos(sp, 2 * kXRegSize, PostIndex);
+    MemOperand tos(sp, 2 * kXRegSize, PostIndex);
 
-  ldp(x19, x20, tos);
-  ldp(x21, x22, tos);
-  ldp(x23, x24, tos);
-  ldp(x25, x26, tos);
-  ldp(x27, x28, tos);
-  ldp(x29, x30, tos);
+    ldp(x19, x20, tos);
+    ldp(x21, x22, tos);
+    ldp(x23, x24, tos);
+    ldp(x25, x26, tos);
+    ldp(x27, x28, tos);
+    ldp(x29, x30, tos);
 
-  ldp(d8, d9, tos);
-  ldp(d10, d11, tos);
-  ldp(d12, d13, tos);
-  ldp(d14, d15, tos);
+    ldp(d8, d9, tos);
+    ldp(d10, d11, tos);
+    ldp(d12, d13, tos);
+    ldp(d14, d15, tos);
+  }
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Autiasp();
+#endif
 }
 
 void TurboAssembler::AssertSpAligned() {
@@ -1712,34 +1633,47 @@ void TurboAssembler::CallCFunction(Register function, int num_of_reg_args,
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    Register scratch1 = x4;
-    Register scratch2 = x5;
-    Push(scratch1, scratch2);
-
-    Label get_pc;
-    Bind(&get_pc);
-    Adr(scratch2, &get_pc);
-
-    Mov(scratch1, ExternalReference::fast_c_call_caller_pc_address(isolate()));
-    Str(scratch2, MemOperand(scratch1));
-    Mov(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    Str(fp, MemOperand(scratch1));
-
-    Pop(scratch2, scratch1);
+  Register pc_scratch = x4;
+  Register addr_scratch = x5;
+  Push(pc_scratch, addr_scratch);
+
+  Label get_pc;
+  Bind(&get_pc);
+  Adr(pc_scratch, &get_pc);
+
+  // See x64 code for reasoning about how to address the isolate data fields.
+  if (root_array_available()) {
+    Str(pc_scratch,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_pc_offset()));
+    Str(fp,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Mov(addr_scratch,
+        ExternalReference::fast_c_call_caller_pc_address(isolate()));
+    Str(pc_scratch, MemOperand(addr_scratch));
+    Mov(addr_scratch,
+        ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    Str(fp, MemOperand(addr_scratch));
   }
 
+  Pop(addr_scratch, pc_scratch);
+
   // Call directly. The function called cannot cause a GC, or allow preemption,
   // so the return address in the link register stays correct.
   Call(function);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
-    Register scratch = x4;
-    Push(scratch, xzr);
-    Mov(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    Str(xzr, MemOperand(scratch));
-    Pop(xzr, scratch);
+  // We don't unset the PC; the FP is the source of truth.
+  if (root_array_available()) {
+    Str(xzr,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Push(addr_scratch, xzr);
+    Mov(addr_scratch,
+        ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    Str(xzr, MemOperand(addr_scratch));
+    Pop(xzr, addr_scratch);
   }
 
   if (num_of_reg_args > kRegisterPassedArguments) {
@@ -1800,7 +1734,7 @@ void TurboAssembler::JumpHelper(int64_t offset, RelocInfo::Mode rmode,
 namespace {
 
 // The calculated offset is either:
-// * the 'target' input unmodified if this is a WASM call, or
+// * the 'target' input unmodified if this is a Wasm call, or
 // * the offset of the target from the current PC, in instructions, for any
 //   other type of call.
 static int64_t CalculateTargetOffset(Address target, RelocInfo::Mode rmode,
@@ -2017,18 +1951,22 @@ void TurboAssembler::StoreReturnAddressAndCall(Register target) {
   // GC, since the callee function will return to it.
 
   UseScratchRegisterScope temps(this);
-  Register scratch1 = temps.AcquireX();
+  temps.Exclude(x16, x17);
 
   Label return_location;
-  Adr(scratch1, &return_location);
-  Poke(scratch1, 0);
+  Adr(x17, &return_location);
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Add(x16, sp, kSystemPointerSize);
+  Pacia1716();
+#endif
+  Poke(x17, 0);
 
   if (emit_debug_code()) {
-    // Verify that the slot below fp[kSPOffset]-8 points to the return location.
-    Register scratch2 = temps.AcquireX();
-    Ldr(scratch2, MemOperand(fp, ExitFrameConstants::kSPOffset));
-    Ldr(scratch2, MemOperand(scratch2, -static_cast<int64_t>(kXRegSize)));
-    Cmp(scratch2, scratch1);
+    // Verify that the slot below fp[kSPOffset]-8 points to the signed return
+    // location.
+    Ldr(x16, MemOperand(fp, ExitFrameConstants::kSPOffset));
+    Ldr(x16, MemOperand(x16, -static_cast<int64_t>(kXRegSize)));
+    Cmp(x16, x17);
     Check(eq, AbortReason::kReturnAddressNotFoundInFrame);
   }
 
@@ -2047,19 +1985,20 @@ bool TurboAssembler::IsNearCallOffset(int64_t offset) {
   return is_int26(offset);
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
   BlockPoolsScope scope(this);
-#ifdef DEBUG
-  Label start;
-  bind(&start);
-#endif
   int64_t offset = static_cast<int64_t>(target) -
                    static_cast<int64_t>(options().code_range_start);
   DCHECK_EQ(offset % kInstrSize, 0);
   offset = offset / static_cast<int>(kInstrSize);
   DCHECK(IsNearCallOffset(offset));
   near_call(static_cast<int>(offset), RelocInfo::RUNTIME_ENTRY);
-  DCHECK_EQ(SizeOfCodeGeneratedSince(&start), Deoptimizer::kDeoptExitSize);
+  DCHECK_EQ(SizeOfCodeGeneratedSince(exit),
+            (kind == DeoptimizeKind::kLazy)
+                ? Deoptimizer::kLazyDeoptExitSize
+                : Deoptimizer::kNonLazyDeoptExitSize);
+  USE(exit, kind);
 }
 
 void TurboAssembler::PrepareForTailCall(Register callee_args_count,
@@ -2096,8 +2035,7 @@ void TurboAssembler::PrepareForTailCall(Register callee_args_count,
 
   // Restore caller's frame pointer and return address now as they will be
   // overwritten by the copying loop.
-  Ldr(lr, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
-  Ldr(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  RestoreFPAndLR();
 
   // Now copy callee arguments to the caller frame going backwards to avoid
   // callee arguments corruption (source and destination areas could overlap).
@@ -2242,7 +2180,7 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
   LoadTaggedPointerField(cp,
                          FieldMemOperand(function, JSFunction::kContextOffset));
   // The number of arguments is stored as an int32_t, and -1 is a marker
-  // (SharedFunctionInfo::kDontAdaptArgumentsSentinel), so we need sign
+  // (kDontAdaptArgumentsSentinel), so we need sign
   // extension to correctly handle it.
   LoadTaggedPointerField(
       expected_parameter_count,
@@ -2301,7 +2239,8 @@ void TurboAssembler::TryConvertDoubleToInt64(Register result,
 void TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
                                        Register result,
                                        DoubleRegister double_input,
-                                       StubCallMode stub_mode) {
+                                       StubCallMode stub_mode,
+                                       LinkRegisterStatus lr_status) {
   Label done;
 
   // Try to convert the double to an int64. If successful, the bottom 32 bits
@@ -2309,7 +2248,11 @@ void TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
   TryConvertDoubleToInt64(result, double_input, &done);
 
   // If we fell through then inline version didn't succeed - call stub instead.
-  Push(lr, double_input);
+  if (lr_status == kLRHasNotBeenSaved) {
+    Push<TurboAssembler::kSignLR>(lr, double_input);
+  } else {
+    Push<TurboAssembler::kDontStoreLR>(xzr, double_input);
+  }
 
   // DoubleToI preserves any registers it needs to clobber.
   if (stub_mode == StubCallMode::kCallWasmRuntimeStub) {
@@ -2322,7 +2265,13 @@ void TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
   Ldr(result, MemOperand(sp, 0));
 
   DCHECK_EQ(xzr.SizeInBytes(), double_input.SizeInBytes());
-  Pop(xzr, lr);  // xzr to drop the double input on the stack.
+
+  if (lr_status == kLRHasNotBeenSaved) {
+    // Pop into xzr here to drop the double input on the stack:
+    Pop<TurboAssembler::kAuthLR>(xzr, lr);
+  } else {
+    Drop(2);
+  }
 
   Bind(&done);
   // Keep our invariant that the upper 32 bits are zero.
@@ -2330,18 +2279,17 @@ void TurboAssembler::TruncateDoubleToI(Isolate* isolate, Zone* zone,
 }
 
 void TurboAssembler::Prologue() {
-  Push(lr, fp, cp, x1);
+  Push<TurboAssembler::kSignLR>(lr, fp, cp, x1);
   Add(fp, sp, StandardFrameConstants::kFixedFrameSizeFromFp);
 }
 
 void TurboAssembler::EnterFrame(StackFrame::Type type) {
   UseScratchRegisterScope temps(this);
 
-  if (type == StackFrame::INTERNAL) {
+  if (type == StackFrame::INTERNAL || type == StackFrame::WASM_DEBUG_BREAK) {
     Register type_reg = temps.AcquireX();
     Mov(type_reg, StackFrame::TypeToMarker(type));
-    // type_reg pushed twice for alignment.
-    Push(lr, fp, type_reg, type_reg);
+    Push<TurboAssembler::kSignLR>(lr, fp, type_reg, padreg);
     const int kFrameSize =
         TypedFrameConstants::kFixedFrameSizeFromFp + kSystemPointerSize;
     Add(fp, sp, kFrameSize);
@@ -2354,7 +2302,7 @@ void TurboAssembler::EnterFrame(StackFrame::Type type) {
              type == StackFrame::WASM_EXIT) {
     Register type_reg = temps.AcquireX();
     Mov(type_reg, StackFrame::TypeToMarker(type));
-    Push(lr, fp);
+    Push<TurboAssembler::kSignLR>(lr, fp);
     Mov(fp, sp);
     Push(type_reg, padreg);
     // sp[3] : lr
@@ -2368,7 +2316,7 @@ void TurboAssembler::EnterFrame(StackFrame::Type type) {
 
     // Users of this frame type push a context pointer after the type field,
     // so do it here to keep the stack pointer aligned.
-    Push(lr, fp, type_reg, cp);
+    Push<TurboAssembler::kSignLR>(lr, fp, type_reg, cp);
 
     // The context pointer isn't part of the fixed frame, so add an extra slot
     // to account for it.
@@ -2385,7 +2333,7 @@ void TurboAssembler::LeaveFrame(StackFrame::Type type) {
   // Drop the execution stack down to the frame pointer and restore
   // the caller frame pointer and return address.
   Mov(sp, fp);
-  Pop(fp, lr);
+  Pop<TurboAssembler::kAuthLR>(fp, lr);
 }
 
 void MacroAssembler::ExitFramePreserveFPRegs() {
@@ -2415,7 +2363,7 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, const Register& scratch,
          frame_type == StackFrame::BUILTIN_EXIT);
 
   // Set up the new stack frame.
-  Push(lr, fp);
+  Push<TurboAssembler::kSignLR>(lr, fp);
   Mov(fp, sp);
   Mov(scratch, StackFrame::TypeToMarker(frame_type));
   Push(scratch, xzr);
@@ -2498,7 +2446,7 @@ void MacroAssembler::LeaveExitFrame(bool restore_doubles,
   //   fp -> fp[0]: CallerFP (old fp)
   //         fp[...]: The rest of the frame.
   Mov(sp, fp);
-  Pop(fp, lr);
+  Pop<TurboAssembler::kAuthLR>(fp, lr);
 }
 
 void MacroAssembler::LoadGlobalProxy(Register dst) {
@@ -2675,30 +2623,6 @@ void TurboAssembler::DecompressAnyTagged(const Register& destination,
   RecordComment("]");
 }
 
-int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
-  // Make sure the safepoint registers list is what we expect.
-  DCHECK_EQ(CPURegList::GetSafepointSavedRegisters().list(), 0x6FFCFFFF);
-
-  // Safepoint registers are stored contiguously on the stack, but not all the
-  // registers are saved. The following registers are excluded:
-  //  - x16 and x17 (ip0 and ip1) because they shouldn't be preserved outside of
-  //    the macro assembler.
-  //  - x31 (sp) because the system stack pointer doesn't need to be included
-  //    in safepoint registers.
-  //
-  // This function implements the mapping of register code to index into the
-  // safepoint register slots.
-  if ((reg_code >= 0) && (reg_code <= 15)) {
-    return reg_code;
-  } else if ((reg_code >= 18) && (reg_code <= 30)) {
-    // Skip ip0 and ip1.
-    return reg_code - 2;
-  } else {
-    // This register has no safepoint register slot.
-    UNREACHABLE();
-  }
-}
-
 void TurboAssembler::CheckPageFlag(const Register& object, int mask,
                                    Condition cc, Label* condition_met) {
   UseScratchRegisterScope temps(this);
@@ -2751,25 +2675,19 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
 
 void TurboAssembler::SaveRegisters(RegList registers) {
   DCHECK_GT(NumRegs(registers), 0);
-  CPURegList regs(lr);
-  for (int i = 0; i < Register::kNumRegisters; ++i) {
-    if ((registers >> i) & 1u) {
-      regs.Combine(Register::XRegFromCode(i));
-    }
-  }
-
+  CPURegList regs(CPURegister::kRegister, kXRegSizeInBits, registers);
+  // If we were saving LR, we might need to sign it.
+  DCHECK(!regs.IncludesAliasOf(lr));
+  regs.Align();
   PushCPURegList(regs);
 }
 
 void TurboAssembler::RestoreRegisters(RegList registers) {
   DCHECK_GT(NumRegs(registers), 0);
-  CPURegList regs(lr);
-  for (int i = 0; i < Register::kNumRegisters; ++i) {
-    if ((registers >> i) & 1u) {
-      regs.Combine(Register::XRegFromCode(i));
-    }
-  }
-
+  CPURegList regs(CPURegister::kRegister, kXRegSizeInBits, registers);
+  // If we were saving LR, we might need to sign it.
+  DCHECK(!regs.IncludesAliasOf(lr));
+  regs.Align();
   PopCPURegList(regs);
 }
 
@@ -2924,11 +2842,11 @@ void MacroAssembler::RecordWrite(Register object, Operand offset,
 
   // Record the actual write.
   if (lr_status == kLRHasNotBeenSaved) {
-    Push(padreg, lr);
+    Push<TurboAssembler::kSignLR>(padreg, lr);
   }
   CallRecordWriteStub(object, offset, remembered_set_action, fp_mode);
   if (lr_status == kLRHasNotBeenSaved) {
-    Pop(lr, padreg);
+    Pop<TurboAssembler::kAuthLR>(lr, padreg);
   }
 
   Bind(&done);
@@ -2944,14 +2862,6 @@ void TurboAssembler::AssertUnreachable(AbortReason reason) {
   if (emit_debug_code()) Abort(reason);
 }
 
-void MacroAssembler::AssertRegisterIsRoot(Register reg, RootIndex index,
-                                          AbortReason reason) {
-  if (emit_debug_code()) {
-    CompareRoot(reg, index);
-    Check(eq, reason);
-  }
-}
-
 void TurboAssembler::Check(Condition cond, AbortReason reason) {
   Label ok;
   B(cond, &ok);
@@ -2961,6 +2871,7 @@ void TurboAssembler::Check(Condition cond, AbortReason reason) {
 }
 
 void TurboAssembler::Trap() { Brk(0); }
+void TurboAssembler::DebugBreak() { Debug("DebugBreak", 0, BREAK); }
 
 void TurboAssembler::Abort(AbortReason reason) {
 #ifdef DEBUG
@@ -3182,7 +3093,7 @@ void TurboAssembler::Printf(const char* format, CPURegister arg0,
   // Preserve all caller-saved registers as well as NZCV.
   // PushCPURegList asserts that the size of each list is a multiple of 16
   // bytes.
-  PushCPURegList(saved_registers);
+  PushCPURegList<kDontStoreLR>(saved_registers);
   PushCPURegList(kCallerSavedV);
 
   // We can use caller-saved registers as scratch values (except for argN).
@@ -3235,7 +3146,7 @@ void TurboAssembler::Printf(const char* format, CPURegister arg0,
   }
 
   PopCPURegList(kCallerSavedV);
-  PopCPURegList(saved_registers);
+  PopCPURegList<kDontLoadLR>(saved_registers);
 
   TmpList()->set_list(old_tmp_list);
   FPTmpList()->set_list(old_fp_tmp_list);
@@ -3273,6 +3184,35 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
   Mov(kSpeculationPoisonRegister, -1);
 }
 
+void TurboAssembler::RestoreFPAndLR() {
+  static_assert(StandardFrameConstants::kCallerFPOffset + kSystemPointerSize ==
+                    StandardFrameConstants::kCallerPCOffset,
+                "Offsets must be consecutive for ldp!");
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  // Make sure we can use x16 and x17.
+  UseScratchRegisterScope temps(this);
+  temps.Exclude(x16, x17);
+  // We can load the return address directly into x17.
+  Add(x16, fp, StandardFrameConstants::kCallerSPOffset);
+  Ldp(fp, x17, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  Autia1716();
+  Mov(lr, x17);
+#else
+  Ldp(fp, lr, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+#endif
+}
+
+void TurboAssembler::StoreReturnAddressInWasmExitFrame(Label* return_location) {
+  UseScratchRegisterScope temps(this);
+  temps.Exclude(x16, x17);
+  Adr(x17, return_location);
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  Add(x16, fp, WasmExitFrameConstants::kCallingPCOffset + kSystemPointerSize);
+  Pacia1716();
+#endif
+  Str(x17, MemOperand(fp, WasmExitFrameConstants::kCallingPCOffset));
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/codegen/arm64/macro-assembler-arm64.h b/deps/v8/src/codegen/arm64/macro-assembler-arm64.h
index f7fbb1105d..7b1fb69e95 100644
--- a/deps/v8/src/codegen/arm64/macro-assembler-arm64.h
+++ b/deps/v8/src/codegen/arm64/macro-assembler-arm64.h
@@ -18,12 +18,6 @@
 
 // Simulator specific helpers.
 #if USE_SIMULATOR
-// TODO(all): If possible automatically prepend an indicator like
-// UNIMPLEMENTED or LOCATION.
-#define ASM_UNIMPLEMENTED(message) __ Debug(message, __LINE__, NO_PARAM)
-#define ASM_UNIMPLEMENTED_BREAK(message) \
-  __ Debug(message, __LINE__,            \
-           FLAG_ignore_asm_unimplemented_break ? NO_PARAM : BREAK)
 #if DEBUG
 #define ASM_LOCATION(message) __ Debug("LOCATION: " message, __LINE__, NO_PARAM)
 #define ASM_LOCATION_IN_ASSEMBLER(message) \
@@ -33,8 +27,6 @@
 #define ASM_LOCATION_IN_ASSEMBLER(message)
 #endif
 #else
-#define ASM_UNIMPLEMENTED(message)
-#define ASM_UNIMPLEMENTED_BREAK(message)
 #define ASM_LOCATION(message)
 #define ASM_LOCATION_IN_ASSEMBLER(message)
 #endif
@@ -136,10 +128,6 @@ inline BranchType InvertBranchType(BranchType type) {
 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
-enum TargetAddressStorageMode {
-  CAN_INLINE_TARGET_ADDRESS,
-  NEVER_INLINE_TARGET_ADDRESS
-};
 enum DiscardMoveMode { kDontDiscardForSameWReg, kDiscardForSameWReg };
 
 // The macro assembler supports moving automatically pre-shifted immediates for
@@ -590,6 +578,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   inline void Debug(const char* message, uint32_t code, Instr params = BREAK);
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Print a message to stderr and abort execution.
   void Abort(AbortReason reason);
@@ -630,7 +619,31 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // Returns false, otherwise.
   bool TryOneInstrMoveImmediate(const Register& dst, int64_t imm);
 
-  inline void Bind(Label* label);
+  inline void Bind(Label* label,
+                   BranchTargetIdentifier id = BranchTargetIdentifier::kNone);
+
+  // Control-flow integrity:
+
+  // Define a function entrypoint.
+  inline void CodeEntry();
+  // Define an exception handler.
+  inline void ExceptionHandler();
+  // Define an exception handler and bind a label.
+  inline void BindExceptionHandler(Label* label);
+
+  // Control-flow integrity:
+
+  // Define a jump (BR) target.
+  inline void JumpTarget();
+  // Define a jump (BR) target and bind a label.
+  inline void BindJumpTarget(Label* label);
+  // Define a call (BLR) target. The target also allows tail calls (via BR)
+  // when the target is x16 or x17.
+  inline void CallTarget();
+  // Define a jump/call target.
+  inline void JumpOrCallTarget();
+  // Define a jump/call target and bind a label.
+  inline void BindJumpOrCallTarget(Label* label);
 
   static unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size);
 
@@ -781,20 +794,33 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // The stack pointer must be aligned to 16 bytes on entry and the total size
   // of the specified registers must also be a multiple of 16 bytes.
   //
-  // Other than the registers passed into Pop, the stack pointer and (possibly)
-  // the system stack pointer, these methods do not modify any other registers.
+  // Other than the registers passed into Pop, the stack pointer, (possibly)
+  // the system stack pointer and (possibly) the link register, these methods
+  // do not modify any other registers.
+  //
+  // Some of the methods take an optional LoadLRMode or StoreLRMode template
+  // argument, which specifies whether we need to sign the link register at the
+  // start of the operation, or authenticate it at the end of the operation,
+  // when control flow integrity measures are enabled.
+  // When the mode is kDontLoadLR or kDontStoreLR, LR must not be passed as an
+  // argument to the operation.
+  enum LoadLRMode { kAuthLR, kDontLoadLR };
+  enum StoreLRMode { kSignLR, kDontStoreLR };
+  template <StoreLRMode lr_mode = kDontStoreLR>
   void Push(const CPURegister& src0, const CPURegister& src1 = NoReg,
             const CPURegister& src2 = NoReg, const CPURegister& src3 = NoReg);
   void Push(const CPURegister& src0, const CPURegister& src1,
             const CPURegister& src2, const CPURegister& src3,
             const CPURegister& src4, const CPURegister& src5 = NoReg,
             const CPURegister& src6 = NoReg, const CPURegister& src7 = NoReg);
+  template <LoadLRMode lr_mode = kDontLoadLR>
   void Pop(const CPURegister& dst0, const CPURegister& dst1 = NoReg,
            const CPURegister& dst2 = NoReg, const CPURegister& dst3 = NoReg);
   void Pop(const CPURegister& dst0, const CPURegister& dst1,
            const CPURegister& dst2, const CPURegister& dst3,
            const CPURegister& dst4, const CPURegister& dst5 = NoReg,
            const CPURegister& dst6 = NoReg, const CPURegister& dst7 = NoReg);
+  template <StoreLRMode lr_mode = kDontStoreLR>
   void Push(const Register& src0, const VRegister& src1);
 
   // This is a convenience method for pushing a single Handle<Object>.
@@ -836,7 +862,15 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // kSRegSizeInBits are supported.
   //
   // Otherwise, (Push|Pop)(CPU|X|W|D|S)RegList is preferred.
+  //
+  // The methods take an optional LoadLRMode or StoreLRMode template argument.
+  // When control flow integrity measures are enabled and the link register is
+  // included in 'registers', passing kSignLR to PushCPURegList will sign the
+  // link register before pushing the list, and passing kAuthLR to
+  // PopCPURegList will authenticate it after popping the list.
+  template <StoreLRMode lr_mode = kDontStoreLR>
   void PushCPURegList(CPURegList registers);
+  template <LoadLRMode lr_mode = kDontLoadLR>
   void PopCPURegList(CPURegList registers);
 
   // Calculate how much stack space (in bytes) are required to store caller
@@ -941,7 +975,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // The return address on the stack is used by frame iteration.
   void StoreReturnAddressAndCall(Register target);
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   // Calls a C function.
   // The called function is not allowed to trigger a
@@ -958,7 +993,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // the JS bitwise operations. See ECMA-262 9.5: ToInt32.
   // Exits with 'result' holding the answer.
   void TruncateDoubleToI(Isolate* isolate, Zone* zone, Register result,
-                         DoubleRegister double_input, StubCallMode stub_mode);
+                         DoubleRegister double_input, StubCallMode stub_mode,
+                         LinkRegisterStatus lr_status);
 
   inline void Mul(const Register& rd, const Register& rn, const Register& rm);
 
@@ -1040,10 +1076,18 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   // Poke 'src' onto the stack. The offset is in bytes. The stack pointer must
   // be 16 byte aligned.
+  // When the optional template argument is kSignLR and control flow integrity
+  // measures are enabled, we sign the link register before poking it onto the
+  // stack. 'src' must be lr in this case.
+  template <StoreLRMode lr_mode = kDontStoreLR>
   void Poke(const CPURegister& src, const Operand& offset);
 
   // Peek at a value on the stack, and put it in 'dst'. The offset is in bytes.
   // The stack pointer must be aligned to 16 bytes.
+  // When the optional template argument is kAuthLR and control flow integrity
+  // measures are enabled, we authenticate the link register after peeking the
+  // value. 'dst' must be lr in this case.
+  template <LoadLRMode lr_mode = kDontLoadLR>
   void Peek(const CPURegister& dst, const Operand& offset);
 
   // Poke 'src1' and 'src2' onto the stack. The values written will be adjacent
@@ -1295,6 +1339,12 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void DecompressAnyTagged(const Register& destination,
                            const MemOperand& field_operand);
 
+  // Restore FP and LR from the values stored in the current frame. This will
+  // authenticate the LR when pointer authentication is enabled.
+  void RestoreFPAndLR();
+
+  void StoreReturnAddressInWasmExitFrame(Label* return_location);
+
  protected:
   // The actual Push and Pop implementations. These don't generate any code
   // other than that required for the push or pop. This allows
@@ -1623,21 +1673,27 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
     tbx(vd, vn, vn2, vn3, vn4, vm);
   }
 
+  // For the 'lr_mode' template argument of the following methods, see
+  // PushCPURegList/PopCPURegList.
+  template <StoreLRMode lr_mode = kDontStoreLR>
   inline void PushSizeRegList(
       RegList registers, unsigned reg_size,
       CPURegister::RegisterType type = CPURegister::kRegister) {
-    PushCPURegList(CPURegList(type, reg_size, registers));
+    PushCPURegList<lr_mode>(CPURegList(type, reg_size, registers));
   }
+  template <LoadLRMode lr_mode = kDontLoadLR>
   inline void PopSizeRegList(
       RegList registers, unsigned reg_size,
       CPURegister::RegisterType type = CPURegister::kRegister) {
-    PopCPURegList(CPURegList(type, reg_size, registers));
+    PopCPURegList<lr_mode>(CPURegList(type, reg_size, registers));
   }
+  template <StoreLRMode lr_mode = kDontStoreLR>
   inline void PushXRegList(RegList regs) {
-    PushSizeRegList(regs, kXRegSizeInBits);
+    PushSizeRegList<lr_mode>(regs, kXRegSizeInBits);
   }
+  template <LoadLRMode lr_mode = kDontLoadLR>
   inline void PopXRegList(RegList regs) {
-    PopSizeRegList(regs, kXRegSizeInBits);
+    PopSizeRegList<lr_mode>(regs, kXRegSizeInBits);
   }
   inline void PushWRegList(RegList regs) {
     PushSizeRegList(regs, kWRegSizeInBits);
@@ -1667,11 +1723,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // be aligned to 16 bytes.
   void PeekPair(const CPURegister& dst1, const CPURegister& dst2, int offset);
 
-  // Insert one or more instructions into the instruction stream that encode
-  // some caller-defined data. The instructions used will be executable with no
-  // side effects.
-  inline void InlineData(uint64_t data);
-
   // Preserve the callee-saved registers (as defined by AAPCS64).
   //
   // Higher-numbered registers are pushed before lower-numbered registers, and
@@ -1679,6 +1730,9 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // Floating-point registers are pushed before general-purpose registers, and
   // thus get higher addresses.
   //
+  // When control flow integrity measures are enabled, this method signs the
+  // link register before pushing it.
+  //
   // Note that registers are not checked for invalid values. Use this method
   // only if you know that the GC won't try to examine the values on the stack.
   void PushCalleeSavedRegisters();
@@ -1689,12 +1743,13 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // thus come from higher addresses.
   // Floating-point registers are popped after general-purpose registers, and
   // thus come from higher addresses.
+  //
+  // When control flow integrity measures are enabled, this method
+  // authenticates the link register after popping it.
   void PopCalleeSavedRegisters();
 
   // Helpers ------------------------------------------------------------------
 
-  static int SafepointRegisterStackIndex(int reg_code);
-
   template <typename Field>
   void DecodeField(Register dst, Register src) {
     static const int shift = Field::kShift;
@@ -1925,25 +1980,8 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   // ---------------------------------------------------------------------------
   // Debugging.
 
-  void AssertRegisterIsRoot(
-      Register reg, RootIndex index,
-      AbortReason reason = AbortReason::kRegisterDidNotMatchExpectedRoot);
-
   void LoadNativeContextSlot(int index, Register dst);
 
-  // Far branches resolving.
-  //
-  // The various classes of branch instructions with immediate offsets have
-  // different ranges. While the Assembler will fail to assemble a branch
-  // exceeding its range, the MacroAssembler offers a mechanism to resolve
-  // branches to too distant targets, either by tweaking the generated code to
-  // use branch instructions with wider ranges or generating veneers.
-  //
-  // Currently branches to distant targets are resolved using unconditional
-  // branch isntructions with a range of +-128MB. If that becomes too little
-  // (!), the mechanism can be extended to generate special veneers for really
-  // far targets.
-
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
 
@@ -2043,7 +2081,7 @@ class UseScratchRegisterScope {
     CPURegList list(reg1, reg2);
     Include(list);
   }
-  void Exclude(const Register& reg1, const Register& reg2) {
+  void Exclude(const Register& reg1, const Register& reg2 = NoReg) {
     CPURegList list(reg1, reg2);
     Exclude(list);
   }
diff --git a/deps/v8/src/codegen/arm64/register-arm64.h b/deps/v8/src/codegen/arm64/register-arm64.h
index 756e3dcaf3..03a5900b5a 100644
--- a/deps/v8/src/codegen/arm64/register-arm64.h
+++ b/deps/v8/src/codegen/arm64/register-arm64.h
@@ -71,23 +71,6 @@ namespace internal {
 
 constexpr int kRegListSizeInBits = sizeof(RegList) * kBitsPerByte;
 
-const int kNumRegs = kNumberOfRegisters;
-// Registers x0-x17 are caller-saved.
-const int kNumJSCallerSaved = 18;
-const RegList kJSCallerSaved = 0x3ffff;
-
-// Number of registers for which space is reserved in safepoints. Must be a
-// multiple of eight.
-// TODO(all): Refine this number.
-const int kNumSafepointRegisters = 32;
-
-// Define the list of registers actually saved at safepoints.
-// Note that the number of saved registers may be smaller than the reserved
-// space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
-#define kSafepointSavedRegisters CPURegList::GetSafepointSavedRegisters().list()
-#define kNumSafepointSavedRegisters \
-  CPURegList::GetSafepointSavedRegisters().Count()
-
 // Some CPURegister methods can return Register and VRegister types, so we
 // need to declare them in advance.
 class Register;
@@ -539,8 +522,6 @@ using Simd128Register = VRegister;
 // Lists of registers.
 class V8_EXPORT_PRIVATE CPURegList {
  public:
-  CPURegList() = default;
-
   template <typename... CPURegisters>
   explicit CPURegList(CPURegister reg0, CPURegisters... regs)
       : list_(CPURegister::ListOf(reg0, regs...)),
@@ -602,10 +583,6 @@ class V8_EXPORT_PRIVATE CPURegList {
   void Combine(int code);
   void Remove(int code);
 
-  // Remove all callee-saved registers from the list. This can be useful when
-  // preparing registers for an AAPCS64 function call, for example.
-  void RemoveCalleeSaved();
-
   // Align the list to 16 bytes.
   void Align();
 
@@ -622,9 +599,6 @@ class V8_EXPORT_PRIVATE CPURegList {
   static CPURegList GetCallerSaved(int size = kXRegSizeInBits);
   static CPURegList GetCallerSavedV(int size = kDRegSizeInBits);
 
-  // Registers saved as safepoints.
-  static CPURegList GetSafepointSavedRegisters();
-
   bool IsEmpty() const {
     return list_ == 0;
   }
diff --git a/deps/v8/src/codegen/assembler-arch.h b/deps/v8/src/codegen/assembler-arch.h
index cab4cbfc3b..d56b372504 100644
--- a/deps/v8/src/codegen/assembler-arch.h
+++ b/deps/v8/src/codegen/assembler-arch.h
@@ -15,7 +15,7 @@
 #include "src/codegen/arm64/assembler-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/codegen/arm/assembler-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/codegen/ppc/assembler-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/codegen/mips/assembler-mips.h"
diff --git a/deps/v8/src/codegen/assembler-inl.h b/deps/v8/src/codegen/assembler-inl.h
index fd08a38555..8c81315d50 100644
--- a/deps/v8/src/codegen/assembler-inl.h
+++ b/deps/v8/src/codegen/assembler-inl.h
@@ -15,7 +15,7 @@
 #include "src/codegen/arm64/assembler-arm64-inl.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/codegen/arm/assembler-arm-inl.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/codegen/ppc/assembler-ppc-inl.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/codegen/mips/assembler-mips-inl.h"
diff --git a/deps/v8/src/codegen/assembler.cc b/deps/v8/src/codegen/assembler.cc
index bc30192a7c..4bda1260a9 100644
--- a/deps/v8/src/codegen/assembler.cc
+++ b/deps/v8/src/codegen/assembler.cc
@@ -70,8 +70,7 @@ AssemblerOptions AssemblerOptions::Default(Isolate* isolate) {
 #endif
   options.inline_offheap_trampolines &= !generating_embedded_builtin;
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
-  const base::AddressRegion& code_range =
-      isolate->heap()->memory_allocator()->code_range();
+  const base::AddressRegion& code_range = isolate->heap()->code_range();
   DCHECK_IMPLIES(code_range.begin() != kNullAddress, !code_range.is_empty());
   options.code_range_start = code_range.begin();
 #endif
diff --git a/deps/v8/src/codegen/assembler.h b/deps/v8/src/codegen/assembler.h
index 92925a5bf9..1c287222e9 100644
--- a/deps/v8/src/codegen/assembler.h
+++ b/deps/v8/src/codegen/assembler.h
@@ -143,7 +143,7 @@ enum class CodeObjectRequired { kNo, kYes };
 
 struct V8_EXPORT_PRIVATE AssemblerOptions {
   // Recording reloc info for external references and off-heap targets is
-  // needed whenever code is serialized, e.g. into the snapshot or as a WASM
+  // needed whenever code is serialized, e.g. into the snapshot or as a Wasm
   // module. This flag allows this reloc info to be disabled for code that
   // will not survive process destruction.
   bool record_reloc_info_for_serialization = true;
diff --git a/deps/v8/src/codegen/code-stub-assembler.cc b/deps/v8/src/codegen/code-stub-assembler.cc
index 702a64d091..0464faea3b 100644
--- a/deps/v8/src/codegen/code-stub-assembler.cc
+++ b/deps/v8/src/codegen/code-stub-assembler.cc
@@ -23,6 +23,7 @@
 #include "src/objects/oddball.h"
 #include "src/objects/ordered-hash-table-inl.h"
 #include "src/objects/property-cell.h"
+#include "src/roots/roots.h"
 #include "src/wasm/wasm-objects.h"
 
 namespace v8 {
@@ -116,8 +117,7 @@ void CodeStubAssembler::Check(const NodeGenerator<BoolT>& condition_body,
                               const char* message, const char* file, int line,
                               std::initializer_list<ExtraNode> extra_nodes) {
   BranchGenerator branch = [=](Label* ok, Label* not_ok) {
-    Node* condition = condition_body();
-    DCHECK_NOT_NULL(condition);
+    TNode<BoolT> condition = condition_body();
     Branch(condition, ok, not_ok);
   };
 
@@ -146,7 +146,8 @@ TNode<IntPtrT> CodeStubAssembler::IntPtrToParameter<IntPtrT>(
 
 void CodeStubAssembler::CollectCallableFeedback(
     TNode<Object> maybe_target, TNode<Context> context,
-    TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot_id) {
+    TNode<FeedbackVector> feedback_vector, TNode<UintPtrT> slot_id,
+    CallableFeedbackMode mode) {
   Label extra_checks(this, Label::kDeferred), done(this);
 
   // Check if we have monomorphic {target} feedback already.
@@ -176,7 +177,47 @@ void CodeStubAssembler::CollectCallableFeedback(
     // If the weak reference is cleared, we have a new chance to become
     // monomorphic.
     Comment("check if weak reference is cleared");
-    Branch(IsCleared(feedback), &initialize, &mark_megamorphic);
+    GotoIf(IsCleared(feedback), &initialize);
+    GotoIf(TaggedIsSmi(maybe_target), &mark_megamorphic);
+
+    if (mode == CallableFeedbackMode::kDontCollectFeedbackCell) {
+      Goto(&mark_megamorphic);
+    } else {
+      Label try_transition_to_feedback_cell(this);
+
+      // Check if {target} is a JSFunction.
+      Comment("check if target is a JSFunction");
+      TNode<HeapObject> target = CAST(maybe_target);
+      GotoIfNot(IsJSFunction(target), &mark_megamorphic);
+
+      // Check if {target}s feedback vector cell matches the {feedback_value}.
+      TNode<HeapObject> feedback_value = GetHeapObjectAssumeWeak(feedback);
+      TNode<Object> target_feedback_cell =
+          LoadObjectField(target, JSFunction::kFeedbackCellOffset);
+      Branch(TaggedEqual(feedback_value, target_feedback_cell), &done,
+             &try_transition_to_feedback_cell);
+
+      BIND(&try_transition_to_feedback_cell);
+      {
+        // Check if {target} and {feedback_value} are both JSFunctions with
+        // the same feedback vector cell, and that those functions were
+        // actually compiled already.
+        GotoIfNot(IsJSFunction(feedback_value), &mark_megamorphic);
+        TNode<HeapObject> feedback_cell = CAST(
+            LoadObjectField(feedback_value, JSFunction::kFeedbackCellOffset));
+        GotoIfNot(TaggedEqual(feedback_cell, target_feedback_cell),
+                  &mark_megamorphic);
+        GotoIfNot(IsFeedbackCell(feedback_cell), &mark_megamorphic);
+
+        // Record the feedback vector cell.
+        Comment("transition to polymorphic");
+        StoreWeakReferenceInFeedbackVector(feedback_vector, slot_id,
+                                           feedback_cell);
+        ReportFeedbackUpdate(feedback_vector, slot_id,
+                             "Call:FeedbackVectorCell");
+        Goto(&done);
+      }
+    }
 
     BIND(&initialize);
     {
@@ -255,7 +296,8 @@ void CodeStubAssembler::CollectCallFeedback(
   IncrementCallCount(feedback_vector, slot_id);
 
   // Collect the callable {target} feedback.
-  CollectCallableFeedback(maybe_target, context, feedback_vector, slot_id);
+  CollectCallableFeedback(maybe_target, context, feedback_vector, slot_id,
+                          CallableFeedbackMode::kCollectFeedbackCell);
   Goto(&feedback_done);
 
   BIND(&feedback_done);
@@ -718,6 +760,49 @@ TNode<BoolT> CodeStubAssembler::IsValidSmiIndex(TNode<Smi> smi) {
   return Int32TrueConstant();
 }
 
+TNode<IntPtrT> CodeStubAssembler::TaggedIndexToIntPtr(
+    TNode<TaggedIndex> value) {
+  return Signed(WordSar(BitcastTaggedToWordForTagAndSmiBits(value),
+                        IntPtrConstant(kSmiTagSize)));
+}
+
+TNode<TaggedIndex> CodeStubAssembler::IntPtrToTaggedIndex(
+    TNode<IntPtrT> value) {
+  return ReinterpretCast<TaggedIndex>(
+      BitcastWordToTaggedSigned(WordShl(value, IntPtrConstant(kSmiTagSize))));
+}
+
+TNode<Smi> CodeStubAssembler::TaggedIndexToSmi(TNode<TaggedIndex> value) {
+  if (SmiValuesAre32Bits()) {
+    DCHECK_EQ(kSmiShiftSize, 31);
+    return BitcastWordToTaggedSigned(
+        WordShl(BitcastTaggedToWordForTagAndSmiBits(value),
+                IntPtrConstant(kSmiShiftSize)));
+  }
+  DCHECK(SmiValuesAre31Bits());
+  DCHECK_EQ(kSmiShiftSize, 0);
+  return ReinterpretCast<Smi>(value);
+}
+
+TNode<TaggedIndex> CodeStubAssembler::SmiToTaggedIndex(TNode<Smi> value) {
+  if (kSystemPointerSize == kInt32Size) {
+    return ReinterpretCast<TaggedIndex>(value);
+  }
+  if (SmiValuesAre32Bits()) {
+    DCHECK_EQ(kSmiShiftSize, 31);
+    return ReinterpretCast<TaggedIndex>(BitcastWordToTaggedSigned(
+        WordSar(BitcastTaggedToWordForTagAndSmiBits(value),
+                IntPtrConstant(kSmiShiftSize))));
+  }
+  DCHECK(SmiValuesAre31Bits());
+  DCHECK_EQ(kSmiShiftSize, 0);
+  // Just sign-extend the lower 32 bits.
+  TNode<Int32T> raw =
+      TruncateWordToInt32(BitcastTaggedToWordForTagAndSmiBits(value));
+  return ReinterpretCast<TaggedIndex>(
+      BitcastWordToTaggedSigned(ChangeInt32ToIntPtr(raw)));
+}
+
 TNode<Smi> CodeStubAssembler::NormalizeSmiIndex(TNode<Smi> smi_index) {
   if (COMPRESS_POINTERS_BOOL) {
     TNode<Int32T> raw =
@@ -1497,8 +1582,7 @@ void CodeStubAssembler::BranchIfToBooleanIsTrue(SloppyTNode<Object> value,
 
 TNode<Object> CodeStubAssembler::LoadFromParentFrame(int offset) {
   TNode<RawPtrT> frame_pointer = LoadParentFramePointer();
-  return CAST(
-      Load(MachineType::AnyTagged(), frame_pointer, IntPtrConstant(offset)));
+  return LoadFullTagged(frame_pointer, IntPtrConstant(offset));
 }
 
 Node* CodeStubAssembler::LoadObjectField(SloppyTNode<HeapObject> object,
@@ -1521,8 +1605,7 @@ TNode<IntPtrT> CodeStubAssembler::LoadAndUntagObjectField(
 #if V8_TARGET_LITTLE_ENDIAN
     offset += 4;
 #endif
-    return ChangeInt32ToIntPtr(
-        LoadObjectField(object, offset, MachineType::Int32()));
+    return ChangeInt32ToIntPtr(LoadObjectField<Int32T>(object, offset));
   } else {
     return SmiToIntPtr(
         LoadObjectField(object, offset, MachineType::TaggedSigned()));
@@ -1551,9 +1634,10 @@ TNode<Float64T> CodeStubAssembler::LoadHeapNumberValue(
       object, HeapNumber::kValueOffset, MachineType::Float64()));
 }
 
-TNode<Map> CodeStubAssembler::GetStructMap(InstanceType instance_type) {
-  Handle<Map> map_handle(Map::GetStructMap(isolate(), instance_type),
-                         isolate());
+TNode<Map> CodeStubAssembler::GetInstanceTypeMap(InstanceType instance_type) {
+  Handle<Map> map_handle(
+      Map::GetInstanceTypeMap(ReadOnlyRoots(isolate()), instance_type),
+      isolate());
   return HeapConstant(map_handle);
 }
 
@@ -1743,8 +1827,8 @@ TNode<HeapObject> CodeStubAssembler::LoadMapPrototype(SloppyTNode<Map> map) {
 TNode<IntPtrT> CodeStubAssembler::LoadMapInstanceSizeInWords(
     SloppyTNode<Map> map) {
   CSA_SLOW_ASSERT(this, IsMap(map));
-  return ChangeInt32ToIntPtr(LoadObjectField(
-      map, Map::kInstanceSizeInWordsOffset, MachineType::Uint8()));
+  return ChangeInt32ToIntPtr(
+      LoadObjectField<Uint8T>(map, Map::kInstanceSizeInWordsOffset));
 }
 
 TNode<IntPtrT> CodeStubAssembler::LoadMapInobjectPropertiesStartInWords(
@@ -1752,9 +1836,8 @@ TNode<IntPtrT> CodeStubAssembler::LoadMapInobjectPropertiesStartInWords(
   CSA_SLOW_ASSERT(this, IsMap(map));
   // See Map::GetInObjectPropertiesStartInWords() for details.
   CSA_ASSERT(this, IsJSObjectMap(map));
-  return ChangeInt32ToIntPtr(LoadObjectField(
-      map, Map::kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
-      MachineType::Uint8()));
+  return ChangeInt32ToIntPtr(LoadObjectField<Uint8T>(
+      map, Map::kInObjectPropertiesStartOrConstructorFunctionIndexOffset));
 }
 
 TNode<IntPtrT> CodeStubAssembler::LoadMapConstructorFunctionIndex(
@@ -1762,9 +1845,8 @@ TNode<IntPtrT> CodeStubAssembler::LoadMapConstructorFunctionIndex(
   CSA_SLOW_ASSERT(this, IsMap(map));
   // See Map::GetConstructorFunctionIndex() for details.
   CSA_ASSERT(this, IsPrimitiveInstanceType(LoadMapInstanceType(map)));
-  return ChangeInt32ToIntPtr(LoadObjectField(
-      map, Map::kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
-      MachineType::Uint8()));
+  return ChangeInt32ToIntPtr(LoadObjectField<Uint8T>(
+      map, Map::kInObjectPropertiesStartOrConstructorFunctionIndexOffset));
 }
 
 TNode<Object> CodeStubAssembler::LoadMapConstructor(SloppyTNode<Map> map) {
@@ -2443,7 +2525,7 @@ TNode<MaybeObject> CodeStubAssembler::LoadFeedbackVectorSlot(
 }
 
 template TNode<MaybeObject> CodeStubAssembler::LoadFeedbackVectorSlot(
-    TNode<FeedbackVector> feedback_vector, TNode<Smi> slot,
+    TNode<FeedbackVector> feedback_vector, TNode<TaggedIndex> slot,
     int additional_offset);
 template TNode<MaybeObject> CodeStubAssembler::LoadFeedbackVectorSlot(
     TNode<FeedbackVector> feedback_vector, TNode<IntPtrT> slot,
@@ -2854,8 +2936,9 @@ void CodeStubAssembler::StoreObjectFieldRoot(TNode<HeapObject> object,
 }
 
 void CodeStubAssembler::StoreFixedArrayOrPropertyArrayElement(
-    Node* object, Node* index_node, Node* value, WriteBarrierMode barrier_mode,
-    int additional_offset, ParameterMode parameter_mode) {
+    TNode<UnionT<FixedArray, PropertyArray>> object, Node* index_node,
+    TNode<Object> value, WriteBarrierMode barrier_mode, int additional_offset,
+    ParameterMode parameter_mode) {
   CSA_SLOW_ASSERT(
       this, Word32Or(IsFixedArraySubclass(object), IsPropertyArray(object)));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(index_node, parameter_mode));
@@ -2964,8 +3047,9 @@ TNode<Int32T> CodeStubAssembler::EnsureArrayPushable(TNode<Context> context,
 }
 
 void CodeStubAssembler::PossiblyGrowElementsCapacity(
-    ParameterMode mode, ElementsKind kind, Node* array, Node* length,
-    Variable* var_elements, Node* growth, Label* bailout) {
+    ParameterMode mode, ElementsKind kind, TNode<HeapObject> array,
+    Node* length, TVariable<FixedArrayBase>* var_elements, Node* growth,
+    Label* bailout) {
   Label fits(this, var_elements);
   Node* capacity =
       TaggedToParameter(LoadFixedArrayBaseLength(var_elements->value()), mode);
@@ -2974,9 +3058,8 @@ void CodeStubAssembler::PossiblyGrowElementsCapacity(
   Node* new_length = IntPtrOrSmiAdd(growth, length, mode);
   GotoIfNot(IntPtrOrSmiGreaterThan(new_length, capacity, mode), &fits);
   Node* new_capacity = CalculateNewElementsCapacity(new_length, mode);
-  var_elements->Bind(GrowElementsCapacity(array, var_elements->value(), kind,
-                                          kind, capacity, new_capacity, mode,
-                                          bailout));
+  *var_elements = GrowElementsCapacity(array, var_elements->value(), kind, kind,
+                                       capacity, new_capacity, mode, bailout);
   Goto(&fits);
   BIND(&fits);
 }
@@ -3035,17 +3118,19 @@ TNode<Smi> CodeStubAssembler::BuildAppendJSArray(ElementsKind kind,
 
 void CodeStubAssembler::TryStoreArrayElement(ElementsKind kind,
                                              ParameterMode mode, Label* bailout,
-                                             Node* elements, Node* index,
-                                             Node* value) {
+                                             TNode<FixedArrayBase> elements,
+                                             Node* index, TNode<Object> value) {
   if (IsSmiElementsKind(kind)) {
     GotoIf(TaggedIsNotSmi(value), bailout);
   } else if (IsDoubleElementsKind(kind)) {
-    GotoIfNotNumber(CAST(value), bailout);
+    GotoIfNotNumber(value, bailout);
   }
   if (IsDoubleElementsKind(kind)) {
-    value = ChangeNumberToFloat64(CAST(value));
+    StoreElement(elements, kind, index, ChangeNumberToFloat64(CAST(value)),
+                 mode);
+  } else {
+    StoreElement(elements, kind, index, value, mode);
   }
-  StoreElement(elements, kind, index, value, mode);
 }
 
 void CodeStubAssembler::BuildAppendJSArray(ElementsKind kind,
@@ -3321,7 +3406,6 @@ TNode<String> CodeStubAssembler::AllocateSlicedTwoByteString(
                               offset);
 }
 
-
 TNode<NameDictionary> CodeStubAssembler::AllocateNameDictionary(
     int at_least_space_for) {
   return AllocateNameDictionary(IntPtrConstant(at_least_space_for));
@@ -3426,7 +3510,7 @@ TNode<CollectionType> CodeStubAssembler::AllocateOrderedHashTable() {
   const ElementsKind elements_kind = HOLEY_ELEMENTS;
   TNode<IntPtrT> length_intptr = IntPtrConstant(kFixedArrayLength);
   TNode<Map> fixed_array_map =
-      CAST(LoadRoot(CollectionType::GetMapRootIndex()));
+      HeapConstant(CollectionType::GetMap(ReadOnlyRoots(isolate())));
   TNode<CollectionType> table =
       CAST(AllocateFixedArray(elements_kind, length_intptr,
                               kAllowLargeObjectAllocation, fixed_array_map));
@@ -3557,9 +3641,9 @@ void CodeStubAssembler::InitializeJSObjectBodyWithSlackTracking(
 
     // The object still has in-object slack therefore the |unsed_or_unused|
     // field contain the "used" value.
-    TNode<IntPtrT> used_size = Signed(TimesTaggedSize(ChangeUint32ToWord(
-        LoadObjectField(map, Map::kUsedOrUnusedInstanceSizeInWordsOffset,
-                        MachineType::Uint8()))));
+    TNode<IntPtrT> used_size =
+        Signed(TimesTaggedSize(ChangeUint32ToWord(LoadObjectField<Uint8T>(
+            map, Map::kUsedOrUnusedInstanceSizeInWordsOffset))));
 
     Comment("iInitialize filler fields");
     InitializeFieldsWithRoot(object, used_size, instance_size,
@@ -3948,7 +4032,8 @@ TNode<FixedArray> CodeStubAssembler::ExtractToFixedArray(
     Node* capacity, SloppyTNode<Map> source_map, ElementsKind from_kind,
     AllocationFlags allocation_flags, ExtractFixedArrayFlags extract_flags,
     ParameterMode parameter_mode, HoleConversionMode convert_holes,
-    TVariable<BoolT>* var_holes_converted, Node* source_elements_kind) {
+    TVariable<BoolT>* var_holes_converted,
+    base::Optional<TNode<Int32T>> source_elements_kind) {
   DCHECK_NE(first, nullptr);
   DCHECK_NE(count, nullptr);
   DCHECK_NE(capacity, nullptr);
@@ -4070,9 +4155,9 @@ TNode<FixedArray> CodeStubAssembler::ExtractToFixedArray(
 
         // Try to use memcpy if we don't need to convert holes to undefined.
         if (convert_holes == HoleConversionMode::kDontConvert &&
-            source_elements_kind != nullptr) {
+            source_elements_kind) {
           // Only try memcpy if we're not copying object pointers.
-          GotoIfNot(IsFastSmiElementsKind(source_elements_kind),
+          GotoIfNot(IsFastSmiElementsKind(*source_elements_kind),
                     &copy_one_by_one);
 
           const ElementsKind to_smi_kind = PACKED_SMI_ELEMENTS;
@@ -4116,8 +4201,8 @@ TNode<FixedArray> CodeStubAssembler::ExtractToFixedArray(
 }
 
 TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedDoubleArrayFillingHoles(
-    Node* from_array, Node* first, Node* count, Node* capacity,
-    Node* fixed_array_map, TVariable<BoolT>* var_holes_converted,
+    TNode<FixedArrayBase> from_array, Node* first, Node* count, Node* capacity,
+    TNode<Map> fixed_array_map, TVariable<BoolT>* var_holes_converted,
     AllocationFlags allocation_flags, ExtractFixedArrayFlags extract_flags,
     ParameterMode mode) {
   DCHECK_NE(first, nullptr);
@@ -4169,7 +4254,7 @@ TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedDoubleArrayFillingHoles(
         IntPtrSub(var_from_offset.value(), IntPtrConstant(kDoubleSize));
     var_from_offset = from_offset;
 
-    Node* to_offset = from_offset;
+    TNode<IntPtrT> to_offset = from_offset;
 
     Label if_hole(this);
 
@@ -4202,9 +4287,10 @@ TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedDoubleArrayFillingHoles(
 }
 
 TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedArray(
-    Node* source, Node* first, Node* count, Node* capacity,
+    TNode<FixedArrayBase> source, Node* first, Node* count, Node* capacity,
     ExtractFixedArrayFlags extract_flags, ParameterMode parameter_mode,
-    TVariable<BoolT>* var_holes_converted, Node* source_runtime_kind) {
+    TVariable<BoolT>* var_holes_converted,
+    base::Optional<TNode<Int32T>> source_runtime_kind) {
   DCHECK(extract_flags & ExtractFixedArrayFlag::kFixedArrays ||
          extract_flags & ExtractFixedArrayFlag::kFixedDoubleArrays);
   // If we want to replace holes, ExtractFixedArrayFlag::kDontCopyCOW should not
@@ -4282,7 +4368,7 @@ TNode<FixedArrayBase> CodeStubAssembler::ExtractFixedArray(
           kind, capacity, parameter_mode, allocation_flags, source_map);
       FillFixedArrayWithValue(kind, to_elements, count, capacity,
                               RootIndex::kTheHoleValue, parameter_mode);
-      CopyElements(kind, to_elements, IntPtrConstant(0), CAST(source),
+      CopyElements(kind, to_elements, IntPtrConstant(0), source,
                    ParameterToIntPtr(first, parameter_mode),
                    ParameterToIntPtr(count, parameter_mode));
       var_result = to_elements;
@@ -4317,9 +4403,8 @@ void CodeStubAssembler::InitializePropertyArrayLength(
                                  ParameterToTagged(length, mode));
 }
 
-Node* CodeStubAssembler::AllocatePropertyArray(Node* capacity_node,
-                                               ParameterMode mode,
-                                               AllocationFlags flags) {
+TNode<PropertyArray> CodeStubAssembler::AllocatePropertyArray(
+    Node* capacity_node, ParameterMode mode, AllocationFlags flags) {
   CSA_SLOW_ASSERT(this, MatchesParameterMode(capacity_node, mode));
   CSA_ASSERT(this, IntPtrOrSmiGreaterThan(capacity_node,
                                           IntPtrOrSmiConstant(0, mode), mode));
@@ -4330,17 +4415,16 @@ Node* CodeStubAssembler::AllocatePropertyArray(Node* capacity_node,
   RootIndex map_index = RootIndex::kPropertyArrayMap;
   DCHECK(RootsTable::IsImmortalImmovable(map_index));
   StoreMapNoWriteBarrier(array, map_index);
-  InitializePropertyArrayLength(CAST(array), capacity_node, mode);
-  return array;
+  TNode<PropertyArray> property_array = CAST(array);
+  InitializePropertyArrayLength(property_array, capacity_node, mode);
+  return property_array;
 }
 
-void CodeStubAssembler::FillPropertyArrayWithUndefined(Node* array,
-                                                       Node* from_node,
-                                                       Node* to_node,
-                                                       ParameterMode mode) {
+void CodeStubAssembler::FillPropertyArrayWithUndefined(
+    TNode<PropertyArray> array, Node* from_node, Node* to_node,
+    ParameterMode mode) {
   CSA_SLOW_ASSERT(this, MatchesParameterMode(from_node, mode));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(to_node, mode));
-  CSA_SLOW_ASSERT(this, IsPropertyArray(array));
   ElementsKind kind = PACKED_ELEMENTS;
   TNode<Oddball> value = UndefinedConstant();
   BuildFastFixedArrayForEach(
@@ -4352,7 +4436,8 @@ void CodeStubAssembler::FillPropertyArrayWithUndefined(Node* array,
       mode);
 }
 
-void CodeStubAssembler::FillFixedArrayWithValue(ElementsKind kind, Node* array,
+void CodeStubAssembler::FillFixedArrayWithValue(ElementsKind kind,
+                                                TNode<FixedArrayBase> array,
                                                 Node* from_node, Node* to_node,
                                                 RootIndex value_root_index,
                                                 ParameterMode mode) {
@@ -4641,10 +4726,11 @@ void CodeStubAssembler::CopyElements(ElementsKind kind,
 }
 
 void CodeStubAssembler::CopyFixedArrayElements(
-    ElementsKind from_kind, Node* from_array, ElementsKind to_kind,
-    Node* to_array, Node* first_element, Node* element_count, Node* capacity,
-    WriteBarrierMode barrier_mode, ParameterMode mode,
-    HoleConversionMode convert_holes, TVariable<BoolT>* var_holes_converted) {
+    ElementsKind from_kind, TNode<FixedArrayBase> from_array,
+    ElementsKind to_kind, TNode<FixedArrayBase> to_array, Node* first_element,
+    Node* element_count, Node* capacity, WriteBarrierMode barrier_mode,
+    ParameterMode mode, HoleConversionMode convert_holes,
+    TVariable<BoolT>* var_holes_converted) {
   DCHECK_IMPLIES(var_holes_converted != nullptr,
                  convert_holes == HoleConversionMode::kConvertToUndefined);
   CSA_SLOW_ASSERT(this, MatchesParameterMode(element_count, mode));
@@ -4719,10 +4805,10 @@ void CodeStubAssembler::CopyFixedArrayElements(
       var_holes_converted != nullptr ? arraysize(vars) : arraysize(vars) - 1;
   Label decrement(this, num_vars, vars);
 
-  Node* to_array_adjusted =
+  TNode<IntPtrT> to_array_adjusted =
       element_offset_matches
           ? IntPtrSub(BitcastTaggedToWord(to_array), first_from_element_offset)
-          : to_array;
+          : ReinterpretCast<IntPtrT>(to_array);
 
   Branch(WordEqual(var_from_offset.value(), limit_offset), &done, &decrement);
 
@@ -4825,8 +4911,8 @@ TNode<FixedArray> CodeStubAssembler::HeapObjectToFixedArray(
   return UncheckedCast<FixedArray>(base);
 }
 
-void CodeStubAssembler::CopyPropertyArrayValues(Node* from_array,
-                                                Node* to_array,
+void CodeStubAssembler::CopyPropertyArrayValues(TNode<HeapObject> from_array,
+                                                TNode<PropertyArray> to_array,
                                                 Node* property_count,
                                                 WriteBarrierMode barrier_mode,
                                                 ParameterMode mode,
@@ -4834,7 +4920,6 @@ void CodeStubAssembler::CopyPropertyArrayValues(Node* from_array,
   CSA_SLOW_ASSERT(this, MatchesParameterMode(property_count, mode));
   CSA_SLOW_ASSERT(this, Word32Or(IsPropertyArray(from_array),
                                  IsEmptyFixedArray(from_array)));
-  CSA_SLOW_ASSERT(this, IsPropertyArray(to_array));
   Comment("[ CopyPropertyArrayValues");
 
   bool needs_write_barrier = barrier_mode == UPDATE_WRITE_BARRIER;
@@ -4871,7 +4956,8 @@ void CodeStubAssembler::CopyPropertyArrayValues(Node* from_array,
   if (destroy_source == DestroySource::kYes) {
     Label did_zap(this);
     GotoIf(IsEmptyFixedArray(from_array), &did_zap);
-    FillPropertyArrayWithUndefined(from_array, start, property_count, mode);
+    FillPropertyArrayWithUndefined(CAST(from_array), start, property_count,
+                                   mode);
 
     Goto(&did_zap);
     BIND(&did_zap);
@@ -4920,11 +5006,9 @@ Node* CodeStubAssembler::CalculateNewElementsCapacity(Node* old_capacity,
 }
 
 TNode<FixedArrayBase> CodeStubAssembler::TryGrowElementsCapacity(
-    Node* object, Node* elements, ElementsKind kind, Node* key,
-    Label* bailout) {
-  CSA_SLOW_ASSERT(this, TaggedIsNotSmi(object));
+    TNode<HeapObject> object, TNode<FixedArrayBase> elements, ElementsKind kind,
+    TNode<Smi> key, Label* bailout) {
   CSA_SLOW_ASSERT(this, IsFixedArrayWithKindOrEmpty(elements, kind));
-  CSA_SLOW_ASSERT(this, TaggedIsSmi(key));
   TNode<Smi> capacity = LoadFixedArrayBaseLength(elements);
 
   ParameterMode mode = OptimalParameterMode();
@@ -4934,10 +5018,9 @@ TNode<FixedArrayBase> CodeStubAssembler::TryGrowElementsCapacity(
 }
 
 TNode<FixedArrayBase> CodeStubAssembler::TryGrowElementsCapacity(
-    Node* object, Node* elements, ElementsKind kind, Node* key, Node* capacity,
-    ParameterMode mode, Label* bailout) {
+    TNode<HeapObject> object, TNode<FixedArrayBase> elements, ElementsKind kind,
+    Node* key, Node* capacity, ParameterMode mode, Label* bailout) {
   Comment("TryGrowElementsCapacity");
-  CSA_SLOW_ASSERT(this, TaggedIsNotSmi(object));
   CSA_SLOW_ASSERT(this, IsFixedArrayWithKindOrEmpty(elements, kind));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(capacity, mode));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(key, mode));
@@ -4955,10 +5038,10 @@ TNode<FixedArrayBase> CodeStubAssembler::TryGrowElementsCapacity(
 }
 
 TNode<FixedArrayBase> CodeStubAssembler::GrowElementsCapacity(
-    Node* object, Node* elements, ElementsKind from_kind, ElementsKind to_kind,
-    Node* capacity, Node* new_capacity, ParameterMode mode, Label* bailout) {
+    TNode<HeapObject> object, TNode<FixedArrayBase> elements,
+    ElementsKind from_kind, ElementsKind to_kind, Node* capacity,
+    Node* new_capacity, ParameterMode mode, Label* bailout) {
   Comment("[ GrowElementsCapacity");
-  CSA_SLOW_ASSERT(this, TaggedIsNotSmi(object));
   CSA_SLOW_ASSERT(this, IsFixedArrayWithKindOrEmpty(elements, from_kind));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(capacity, mode));
   CSA_SLOW_ASSERT(this, MatchesParameterMode(new_capacity, mode));
@@ -4977,12 +5060,12 @@ TNode<FixedArrayBase> CodeStubAssembler::GrowElementsCapacity(
   // Copy the elements from the old elements store to the new.
   // The size-check above guarantees that the |new_elements| is allocated
   // in new space so we can skip the write barrier.
-  CopyFixedArrayElements(from_kind, CAST(elements), to_kind, new_elements,
+  CopyFixedArrayElements(from_kind, elements, to_kind, new_elements,
                          UncheckedCast<IntPtrT>(capacity),
                          UncheckedCast<IntPtrT>(new_capacity),
                          SKIP_WRITE_BARRIER, mode);
 
-  StoreObjectField(CAST(object), JSObject::kElementsOffset, new_elements);
+  StoreObjectField(object, JSObject::kElementsOffset, new_elements);
   Comment("] GrowElementsCapacity");
   return new_elements;
 }
@@ -5616,6 +5699,10 @@ TNode<BoolT> CodeStubAssembler::IsCallableMap(SloppyTNode<Map> map) {
   return IsSetWord32<Map::Bits1::IsCallableBit>(LoadMapBitField(map));
 }
 
+TNode<BoolT> CodeStubAssembler::IsCoverageInfo(TNode<HeapObject> object) {
+  return IsCoverageInfoMap(LoadMap(object));
+}
+
 TNode<BoolT> CodeStubAssembler::IsDebugInfo(TNode<HeapObject> object) {
   return HasInstanceType(object, DEBUG_INFO_TYPE);
 }
@@ -6037,13 +6124,13 @@ TNode<BoolT> CodeStubAssembler::IsPromiseFulfillReactionJobTask(
 // TODO(jgruber): It might we worth creating an empty_double_array constant to
 // simplify this case.
 TNode<BoolT> CodeStubAssembler::IsFixedArrayWithKindOrEmpty(
-    SloppyTNode<HeapObject> object, ElementsKind kind) {
+    SloppyTNode<FixedArrayBase> object, ElementsKind kind) {
   Label out(this);
   TVARIABLE(BoolT, var_result, Int32TrueConstant());
 
   GotoIf(IsFixedArrayWithKind(object, kind), &out);
 
-  const TNode<Smi> length = LoadFixedArrayBaseLength(CAST(object));
+  const TNode<Smi> length = LoadFixedArrayBaseLength(object);
   GotoIf(SmiEqual(length, SmiConstant(0)), &out);
 
   var_result = Int32FalseConstant();
@@ -6151,13 +6238,35 @@ TNode<BoolT> CodeStubAssembler::IsUniqueName(TNode<HeapObject> object) {
       [=] { return IsSymbolInstanceType(instance_type); });
 }
 
+// Semantics: guaranteed not to be an integer index (i.e. contains non-digit
+// characters, or is outside MAX_SAFE_INTEGER/size_t range). Note that for
+// non-TypedArray receivers, there are additional strings that must be treated
+// as named property keys, namely the range [0xFFFFFFFF, MAX_SAFE_INTEGER].
 TNode<BoolT> CodeStubAssembler::IsUniqueNameNoIndex(TNode<HeapObject> object) {
   TNode<Uint16T> instance_type = LoadInstanceType(object);
   return Select<BoolT>(
       IsInternalizedStringInstanceType(instance_type),
       [=] {
         return IsSetWord32(LoadNameHashField(CAST(object)),
-                           Name::kIsNotArrayIndexMask);
+                           Name::kIsNotIntegerIndexMask);
+      },
+      [=] { return IsSymbolInstanceType(instance_type); });
+}
+
+// Semantics: {object} is a Symbol, or a String that doesn't have a cached
+// index. This returns {true} for strings containing representations of
+// integers in the range above 9999999 (per kMaxCachedArrayIndexLength)
+// and below MAX_SAFE_INTEGER. For CSA_ASSERTs ensuring correct usage, this is
+// better than no checking; and we don't have a good/fast way to accurately
+// check such strings for being within "array index" (uint32_t) range.
+TNode<BoolT> CodeStubAssembler::IsUniqueNameNoCachedIndex(
+    TNode<HeapObject> object) {
+  TNode<Uint16T> instance_type = LoadInstanceType(object);
+  return Select<BoolT>(
+      IsInternalizedStringInstanceType(instance_type),
+      [=] {
+        return IsSetWord32(LoadNameHashField(CAST(object)),
+                           Name::kDoesNotContainCachedArrayIndexMask);
       },
       [=] { return IsSymbolInstanceType(instance_type); });
 }
@@ -6418,9 +6527,8 @@ TNode<BoolT> CodeStubAssembler::IsNumberArrayIndex(TNode<Number> number) {
       [=] { return IsHeapNumberUint32(CAST(number)); });
 }
 
-Node* CodeStubAssembler::FixedArraySizeDoesntFitInNewSpace(Node* element_count,
-                                                           int base_size,
-                                                           ParameterMode mode) {
+TNode<BoolT> CodeStubAssembler::FixedArraySizeDoesntFitInNewSpace(
+    Node* element_count, int base_size, ParameterMode mode) {
   int max_newspace_elements =
       (kMaxRegularHeapObjectSize - base_size) / kTaggedSize;
   return IntPtrOrSmiGreaterThan(
@@ -6826,6 +6934,7 @@ TNode<Numeric> CodeStubAssembler::NonNumberToNumberOrNumeric(
     }
 
     BIND(&if_inputisbigint);
+    CSA_ASSERT(this, Word32And(TaggedIsNotSmi(context), IsContext(context)));
     if (mode == Object::Conversion::kToNumeric) {
       var_result = CAST(input);
       Goto(&end);
@@ -6850,6 +6959,7 @@ TNode<Numeric> CodeStubAssembler::NonNumberToNumberOrNumeric(
 
     BIND(&if_inputisreceiver);
     {
+      CSA_ASSERT(this, Word32And(TaggedIsNotSmi(context), IsContext(context)));
       // The {input} is a JSReceiver, we need to convert it to a Primitive first
       // using the ToPrimitive type conversion, preferably yielding a Number.
       Callable callable = CodeFactory::NonPrimitiveToPrimitive(
@@ -6880,6 +6990,7 @@ TNode<Numeric> CodeStubAssembler::NonNumberToNumberOrNumeric(
 
     BIND(&if_inputisother);
     {
+      CSA_ASSERT(this, Word32And(TaggedIsNotSmi(context), IsContext(context)));
       // The {input} is something else (e.g. Symbol), let the runtime figure
       // out the correct exception.
       // Note: We cannot tail call to the runtime here, as js-to-wasm
@@ -7208,82 +7319,6 @@ TNode<Number> CodeStubAssembler::ToLength_Inline(SloppyTNode<Context> context,
       [=] { return CAST(CallBuiltin(Builtins::kToLength, context, input)); });
 }
 
-TNode<Number> CodeStubAssembler::ToInteger_Inline(
-    SloppyTNode<Context> context, SloppyTNode<Object> input,
-    ToIntegerTruncationMode mode) {
-  Builtins::Name builtin = (mode == kNoTruncation)
-                               ? Builtins::kToInteger
-                               : Builtins::kToInteger_TruncateMinusZero;
-  return Select<Number>(
-      TaggedIsSmi(input), [=] { return CAST(input); },
-      [=] { return CAST(CallBuiltin(builtin, context, input)); });
-}
-
-TNode<Number> CodeStubAssembler::ToInteger(SloppyTNode<Context> context,
-                                           SloppyTNode<Object> input,
-                                           ToIntegerTruncationMode mode) {
-  // We might need to loop once for ToNumber conversion.
-  TVARIABLE(Object, var_arg, input);
-  Label loop(this, &var_arg), out(this);
-  Goto(&loop);
-  BIND(&loop);
-  {
-    // Shared entry points.
-    Label return_zero(this, Label::kDeferred);
-
-    // Load the current {arg} value.
-    TNode<Object> arg = var_arg.value();
-
-    // Check if {arg} is a Smi.
-    GotoIf(TaggedIsSmi(arg), &out);
-
-    // Check if {arg} is a HeapNumber.
-    Label if_argisheapnumber(this),
-        if_argisnotheapnumber(this, Label::kDeferred);
-    Branch(IsHeapNumber(CAST(arg)), &if_argisheapnumber,
-           &if_argisnotheapnumber);
-
-    BIND(&if_argisheapnumber);
-    {
-      TNode<HeapNumber> arg_hn = CAST(arg);
-      // Load the floating-point value of {arg}.
-      TNode<Float64T> arg_value = LoadHeapNumberValue(arg_hn);
-
-      // Check if {arg} is NaN.
-      GotoIfNot(Float64Equal(arg_value, arg_value), &return_zero);
-
-      // Truncate {arg} towards zero.
-      TNode<Float64T> value = Float64Trunc(arg_value);
-
-      if (mode == kTruncateMinusZero) {
-        // Truncate -0.0 to 0.
-        GotoIf(Float64Equal(value, Float64Constant(0.0)), &return_zero);
-      }
-
-      var_arg = ChangeFloat64ToTagged(value);
-      Goto(&out);
-    }
-
-    BIND(&if_argisnotheapnumber);
-    {
-      // Need to convert {arg} to a Number first.
-      var_arg = UncheckedCast<Object>(
-          CallBuiltin(Builtins::kNonNumberToNumber, context, arg));
-      Goto(&loop);
-    }
-
-    BIND(&return_zero);
-    var_arg = SmiConstant(0);
-    Goto(&out);
-  }
-
-  BIND(&out);
-  if (mode == kTruncateMinusZero) {
-    CSA_ASSERT(this, IsNumberNormalized(CAST(var_arg.value())));
-  }
-  return CAST(var_arg.value());
-}
-
 TNode<Uint32T> CodeStubAssembler::DecodeWord32(SloppyTNode<Word32T> word32,
                                                uint32_t shift, uint32_t mask) {
   DCHECK_EQ((mask >> shift) << shift, mask);
@@ -7419,7 +7454,7 @@ void CodeStubAssembler::TryToName(SloppyTNode<Object> key, Label* if_keyisindex,
              &if_has_cached_index);
       // No cached array index. If the string knows that it contains an index,
       // then it must be an uncacheable index. Handle this case in the runtime.
-      GotoIf(IsClearWord32(hash, Name::kIsNotArrayIndexMask), if_bailout);
+      GotoIf(IsClearWord32(hash, Name::kIsNotIntegerIndexMask), if_bailout);
 
       GotoIf(InstanceTypeEqual(var_instance_type.value(), THIN_STRING_TYPE),
              &if_thinstring);
@@ -7742,7 +7777,7 @@ void CodeStubAssembler::NumberDictionaryLookup(
   TNode<IntPtrT> mask = IntPtrSub(capacity, IntPtrConstant(1));
 
   TNode<UintPtrT> hash = ChangeUint32ToWord(ComputeSeededHash(intptr_index));
-  Node* key_as_float64 = RoundIntPtrToFloat64(intptr_index);
+  TNode<Float64T> key_as_float64 = RoundIntPtrToFloat64(intptr_index);
 
   // See Dictionary::FirstProbe().
   TNode<IntPtrT> count = IntPtrConstant(0);
@@ -8411,7 +8446,7 @@ void CodeStubAssembler::TryLookupPropertyInSimpleObject(
     TVariable<HeapObject>* var_meta_storage, TVariable<IntPtrT>* var_name_index,
     Label* if_not_found) {
   CSA_ASSERT(this, IsSimpleObjectMap(map));
-  CSA_ASSERT(this, IsUniqueNameNoIndex(unique_name));
+  CSA_ASSERT(this, IsUniqueNameNoCachedIndex(unique_name));
 
   TNode<Uint32T> bit_field3 = LoadMapBitField3(map);
   Label if_isfastmap(this), if_isslowmap(this);
@@ -8436,7 +8471,7 @@ void CodeStubAssembler::TryLookupPropertyInSimpleObject(
 }
 
 void CodeStubAssembler::TryLookupProperty(
-    SloppyTNode<JSReceiver> object, SloppyTNode<Map> map,
+    SloppyTNode<HeapObject> object, SloppyTNode<Map> map,
     SloppyTNode<Int32T> instance_type, SloppyTNode<Name> unique_name,
     Label* if_found_fast, Label* if_found_dict, Label* if_found_global,
     TVariable<HeapObject>* var_meta_storage, TVariable<IntPtrT>* var_name_index,
@@ -8460,7 +8495,7 @@ void CodeStubAssembler::TryLookupProperty(
                Map::Bits1::IsAccessCheckNeededBit::kMask;
     GotoIf(IsSetWord32(bit_field, mask), if_bailout);
 
-    TNode<GlobalDictionary> dictionary = CAST(LoadSlowProperties(object));
+    TNode<GlobalDictionary> dictionary = CAST(LoadSlowProperties(CAST(object)));
     *var_meta_storage = dictionary;
 
     NameDictionaryLookup<GlobalDictionary>(
@@ -8468,13 +8503,14 @@ void CodeStubAssembler::TryLookupProperty(
   }
 }
 
-void CodeStubAssembler::TryHasOwnProperty(Node* object, Node* map,
-                                          Node* instance_type,
-                                          Node* unique_name, Label* if_found,
-                                          Label* if_not_found,
+void CodeStubAssembler::TryHasOwnProperty(TNode<HeapObject> object,
+                                          TNode<Map> map,
+                                          TNode<Int32T> instance_type,
+                                          TNode<Name> unique_name,
+                                          Label* if_found, Label* if_not_found,
                                           Label* if_bailout) {
   Comment("TryHasOwnProperty");
-  CSA_ASSERT(this, IsUniqueNameNoIndex(CAST(unique_name)));
+  CSA_ASSERT(this, IsUniqueNameNoCachedIndex(unique_name));
   TVARIABLE(HeapObject, var_meta_storage);
   TVARIABLE(IntPtrT, var_name_index);
 
@@ -8671,7 +8707,7 @@ TNode<Object> CodeStubAssembler::CallGetterIfAccessor(
   {
     if (mode == kCallJSGetter) {
       Label if_callable(this), if_function_template_info(this);
-      Node* accessor_pair = value;
+      TNode<AccessorPair> accessor_pair = CAST(value);
       TNode<HeapObject> getter =
           CAST(LoadObjectField(accessor_pair, AccessorPair::kGetterOffset));
       TNode<Map> getter_map = LoadMap(getter);
@@ -8686,8 +8722,7 @@ TNode<Object> CodeStubAssembler::CallGetterIfAccessor(
       BIND(&if_callable);
       {
         // Call the accessor.
-        Callable callable = CodeFactory::Call(isolate());
-        var_value = CallJS(callable, context, getter, receiver);
+        var_value = Call(context, getter, receiver);
         Goto(&done);
       }
 
@@ -8790,7 +8825,7 @@ void CodeStubAssembler::TryGetOwnProperty(
     GetOwnPropertyMode mode) {
   DCHECK_EQ(MachineRepresentation::kTagged, var_value->rep());
   Comment("TryGetOwnProperty");
-  CSA_ASSERT(this, IsUniqueNameNoIndex(unique_name));
+  CSA_ASSERT(this, IsUniqueNameNoCachedIndex(unique_name));
   TVARIABLE(HeapObject, var_meta_storage);
   TVARIABLE(IntPtrT, var_entry);
 
@@ -9276,17 +9311,18 @@ TNode<IntPtrT> CodeStubAssembler::ElementOffsetFromIndex(
     TNode<TIndex> index_node, ElementsKind kind, int base_size) {
   // TODO(v8:9708): Remove IntPtrT variant in favor of UintPtrT.
   static_assert(std::is_same<TIndex, Smi>::value ||
+                    std::is_same<TIndex, TaggedIndex>::value ||
                     std::is_same<TIndex, IntPtrT>::value ||
                     std::is_same<TIndex, UintPtrT>::value,
                 "Only Smi, UintPtrT or IntPtrT index nodes are allowed");
   int element_size_shift = ElementsKindToShiftSize(kind);
   int element_size = 1 << element_size_shift;
-  int const kSmiShiftBits = kSmiShiftSize + kSmiTagSize;
   intptr_t index = 0;
   TNode<IntPtrT> intptr_index_node;
   bool constant_index = false;
   if (std::is_same<TIndex, Smi>::value) {
     TNode<Smi> smi_index_node = ReinterpretCast<Smi>(index_node);
+    int const kSmiShiftBits = kSmiShiftSize + kSmiTagSize;
     element_size_shift -= kSmiShiftBits;
     Smi smi_index;
     constant_index = ToSmiConstant(smi_index_node, &smi_index);
@@ -9298,6 +9334,12 @@ TNode<IntPtrT> CodeStubAssembler::ElementOffsetFromIndex(
       }
     }
     intptr_index_node = BitcastTaggedToWordForTagAndSmiBits(smi_index_node);
+  } else if (std::is_same<TIndex, TaggedIndex>::value) {
+    TNode<TaggedIndex> tagged_index_node =
+        ReinterpretCast<TaggedIndex>(index_node);
+    element_size_shift -= kSmiTagSize;
+    intptr_index_node = BitcastTaggedToWordForTagAndSmiBits(tagged_index_node);
+    constant_index = ToIntPtrConstant(intptr_index_node, &index);
   } else {
     intptr_index_node = ReinterpretCast<IntPtrT>(index_node);
     constant_index = ToIntPtrConstant(intptr_index_node, &index);
@@ -9323,6 +9365,9 @@ CodeStubAssembler::ElementOffsetFromIndex<Smi>(TNode<Smi> index_node,
                                                ElementsKind kind,
                                                int base_size);
 template V8_EXPORT_PRIVATE TNode<IntPtrT>
+CodeStubAssembler::ElementOffsetFromIndex<TaggedIndex>(
+    TNode<TaggedIndex> index_node, ElementsKind kind, int base_size);
+template V8_EXPORT_PRIVATE TNode<IntPtrT>
 CodeStubAssembler::ElementOffsetFromIndex<IntPtrT>(TNode<IntPtrT> index_node,
                                                    ElementsKind kind,
                                                    int base_size);
@@ -9936,8 +9981,8 @@ void CodeStubAssembler::EmitElementStore(
         IsNonextensibleElementsKind(elements_kind))) {
     CSA_ASSERT(this, Word32BinaryNot(IsFixedCOWArrayMap(LoadMap(elements))));
   } else if (IsCOWHandlingStoreMode(store_mode)) {
-    elements = CAST(CopyElementsOnWrite(object, elements, elements_kind, length,
-                                        parameter_mode, bailout));
+    elements = CopyElementsOnWrite(object, elements, elements_kind, length,
+                                   parameter_mode, bailout);
   }
 
   CSA_ASSERT(this, Word32BinaryNot(IsFixedCOWArrayMap(LoadMap(elements))));
@@ -9953,7 +9998,7 @@ Node* CodeStubAssembler::CheckForCapacityGrow(
   Label grow_case(this), no_grow_case(this), done(this),
       grow_bailout(this, Label::kDeferred);
 
-  Node* condition;
+  TNode<BoolT> condition;
   if (IsHoleyElementsKind(kind)) {
     condition = UintPtrGreaterThanOrEqual(key, length);
   } else {
@@ -10011,20 +10056,19 @@ Node* CodeStubAssembler::CheckForCapacityGrow(
   return checked_elements.value();
 }
 
-Node* CodeStubAssembler::CopyElementsOnWrite(Node* object, Node* elements,
-                                             ElementsKind kind, Node* length,
-                                             ParameterMode mode,
-                                             Label* bailout) {
-  VARIABLE(new_elements_var, MachineRepresentation::kTagged, elements);
+TNode<FixedArrayBase> CodeStubAssembler::CopyElementsOnWrite(
+    TNode<HeapObject> object, TNode<FixedArrayBase> elements, ElementsKind kind,
+    Node* length, ParameterMode mode, Label* bailout) {
+  TVARIABLE(FixedArrayBase, new_elements_var, elements);
   Label done(this);
 
   GotoIfNot(IsFixedCOWArrayMap(LoadMap(elements)), &done);
   {
     Node* capacity =
         TaggedToParameter(LoadFixedArrayBaseLength(elements), mode);
-    Node* new_elements = GrowElementsCapacity(object, elements, kind, kind,
-                                              length, capacity, mode, bailout);
-    new_elements_var.Bind(new_elements);
+    TNode<FixedArrayBase> new_elements = GrowElementsCapacity(
+        object, elements, kind, kind, length, capacity, mode, bailout);
+    new_elements_var = new_elements;
     Goto(&done);
   }
 
@@ -12135,9 +12179,7 @@ TNode<Oddball> CodeStubAssembler::InstanceOf(TNode<Object> object,
     GotoIf(IsUndefined(inst_of_handler), &if_nohandler);
 
     // Call the {inst_of_handler} for {callable} and {object}.
-    Node* result = CallJS(
-        CodeFactory::Call(isolate(), ConvertReceiverMode::kNotNullOrUndefined),
-        context, inst_of_handler, callable, object);
+    TNode<Object> result = Call(context, inst_of_handler, callable, object);
 
     // Convert the {result} to a Boolean.
     BranchIfToBooleanIsTrue(result, &return_true, &return_false);
@@ -12428,11 +12470,6 @@ TNode<JSReceiver> CodeStubAssembler::ArraySpeciesCreate(TNode<Context> context,
   return Construct(context, constructor, len);
 }
 
-TNode<BoolT> CodeStubAssembler::IsDetachedBuffer(TNode<JSArrayBuffer> buffer) {
-  TNode<Uint32T> buffer_bit_field = LoadJSArrayBufferBitField(buffer);
-  return IsSetWord32<JSArrayBuffer::WasDetachedBit>(buffer_bit_field);
-}
-
 void CodeStubAssembler::ThrowIfArrayBufferIsDetached(
     SloppyTNode<Context> context, TNode<JSArrayBuffer> array_buffer,
     const char* method_name) {
@@ -12492,30 +12529,52 @@ CodeStubArguments::CodeStubArguments(CodeStubAssembler* assembler,
       argc_(argc),
       base_(),
       fp_(fp != nullptr ? fp : assembler_->LoadFramePointer()) {
+#ifdef V8_REVERSE_JSARGS
+  TNode<IntPtrT> offset = assembler_->IntPtrConstant(
+      (StandardFrameConstants::kFixedSlotCountAboveFp + 1) *
+      kSystemPointerSize);
+#else
   TNode<IntPtrT> offset = assembler_->ElementOffsetFromIndex(
       argc_, SYSTEM_POINTER_ELEMENTS,
       (StandardFrameConstants::kFixedSlotCountAboveFp - 1) *
           kSystemPointerSize);
+#endif
+  // base_ points to the first argument, not the receiver
+  // whether present or not.
   base_ = assembler_->RawPtrAdd(fp_, offset);
 }
 
 TNode<Object> CodeStubArguments::GetReceiver() const {
   DCHECK_EQ(receiver_mode_, ReceiverMode::kHasReceiver);
-  return assembler_->UncheckedCast<Object>(assembler_->LoadFullTagged(
-      base_, assembler_->IntPtrConstant(kSystemPointerSize)));
+#ifdef V8_REVERSE_JSARGS
+  intptr_t offset = -kSystemPointerSize;
+#else
+  intptr_t offset = kSystemPointerSize;
+#endif
+  return assembler_->LoadFullTagged(base_, assembler_->IntPtrConstant(offset));
 }
 
 void CodeStubArguments::SetReceiver(TNode<Object> object) const {
   DCHECK_EQ(receiver_mode_, ReceiverMode::kHasReceiver);
+#ifdef V8_REVERSE_JSARGS
+  intptr_t offset = -kSystemPointerSize;
+#else
+  intptr_t offset = kSystemPointerSize;
+#endif
   assembler_->StoreFullTaggedNoWriteBarrier(
-      base_, assembler_->IntPtrConstant(kSystemPointerSize), object);
+      base_, assembler_->IntPtrConstant(offset), object);
 }
 
 TNode<RawPtrT> CodeStubArguments::AtIndexPtr(TNode<IntPtrT> index) const {
+#ifdef V8_REVERSE_JSARGS
+  TNode<IntPtrT> offset =
+      assembler_->ElementOffsetFromIndex(index, SYSTEM_POINTER_ELEMENTS, 0);
+#else
   TNode<IntPtrT> negated_index =
       assembler_->IntPtrOrSmiSub(assembler_->IntPtrConstant(0), index);
   TNode<IntPtrT> offset = assembler_->ElementOffsetFromIndex(
       negated_index, SYSTEM_POINTER_ELEMENTS, 0);
+#endif
   return assembler_->RawPtrAdd(base_, offset);
 }
 
@@ -12579,18 +12638,20 @@ void CodeStubArguments::ForEach(
   if (last == nullptr) {
     last = argc_;
   }
-  TNode<RawPtrT> start = assembler_->RawPtrSub(
-      base_,
-      assembler_->ElementOffsetFromIndex(first, SYSTEM_POINTER_ELEMENTS));
-  TNode<RawPtrT> end = assembler_->RawPtrSub(
-      base_, assembler_->ElementOffsetFromIndex(last, SYSTEM_POINTER_ELEMENTS));
+  TNode<RawPtrT> start = AtIndexPtr(first);
+  TNode<RawPtrT> end = AtIndexPtr(last);
+#ifdef V8_REVERSE_JSARGS
+  const int increment = kSystemPointerSize;
+#else
+  const int increment = -kSystemPointerSize;
+#endif
   assembler_->BuildFastLoop<RawPtrT>(
       vars, start, end,
       [&](TNode<RawPtrT> current) {
-        TNode<Object> arg = assembler_->Load<Object>(current);
+        TNode<Object> arg = assembler_->LoadFullTagged(current);
         body(arg);
       },
-      -kSystemPointerSize, CodeStubAssembler::IndexAdvanceMode::kPost);
+      increment, CodeStubAssembler::IndexAdvanceMode::kPost);
 }
 
 void CodeStubArguments::PopAndReturn(TNode<Object> value) {
@@ -12852,53 +12913,50 @@ TNode<JSFunction> CodeStubAssembler::AllocateFunctionWithMapAndContext(
   return CAST(fun);
 }
 
-void CodeStubAssembler::CheckPrototypeEnumCache(Node* receiver,
-                                                Node* receiver_map,
+void CodeStubAssembler::CheckPrototypeEnumCache(TNode<JSReceiver> receiver,
+                                                TNode<Map> receiver_map,
                                                 Label* if_fast,
                                                 Label* if_slow) {
-  VARIABLE(var_object, MachineRepresentation::kTagged, receiver);
-  VARIABLE(var_object_map, MachineRepresentation::kTagged, receiver_map);
+  TVARIABLE(JSReceiver, var_object, receiver);
+  TVARIABLE(Map, object_map, receiver_map);
 
-  Label loop(this, {&var_object, &var_object_map}), done_loop(this);
+  Label loop(this, {&var_object, &object_map}), done_loop(this);
   Goto(&loop);
   BIND(&loop);
   {
-    // Check that there are no elements on the current {object}.
+    // Check that there are no elements on the current {var_object}.
     Label if_no_elements(this);
-    Node* object = var_object.value();
-    Node* object_map = var_object_map.value();
 
     // The following relies on the elements only aliasing with JSProxy::target,
-    // which is a Javascript value and hence cannot be confused with an elements
+    // which is a JavaScript value and hence cannot be confused with an elements
     // backing store.
     STATIC_ASSERT(static_cast<int>(JSObject::kElementsOffset) ==
                   static_cast<int>(JSProxy::kTargetOffset));
     TNode<Object> object_elements =
-        LoadObjectField(object, JSObject::kElementsOffset);
+        LoadObjectField(var_object.value(), JSObject::kElementsOffset);
     GotoIf(IsEmptyFixedArray(object_elements), &if_no_elements);
     GotoIf(IsEmptySlowElementDictionary(object_elements), &if_no_elements);
 
     // It might still be an empty JSArray.
-    GotoIfNot(IsJSArrayMap(object_map), if_slow);
-    TNode<Number> object_length = LoadJSArrayLength(CAST(object));
+    GotoIfNot(IsJSArrayMap(object_map.value()), if_slow);
+    TNode<Number> object_length = LoadJSArrayLength(CAST(var_object.value()));
     Branch(TaggedEqual(object_length, SmiConstant(0)), &if_no_elements,
            if_slow);
 
-    // Continue with the {object}s prototype.
+    // Continue with {var_object}'s prototype.
     BIND(&if_no_elements);
-    object = LoadMapPrototype(object_map);
+    TNode<HeapObject> object = LoadMapPrototype(object_map.value());
     GotoIf(IsNull(object), if_fast);
 
     // For all {object}s but the {receiver}, check that the cache is empty.
-    var_object.Bind(object);
+    var_object = CAST(object);
     object_map = LoadMap(object);
-    var_object_map.Bind(object_map);
-    TNode<WordT> object_enum_length = LoadMapEnumLength(object_map);
+    TNode<WordT> object_enum_length = LoadMapEnumLength(object_map.value());
     Branch(WordEqual(object_enum_length, IntPtrConstant(0)), &loop, if_slow);
   }
 }
 
-TNode<Map> CodeStubAssembler::CheckEnumCache(TNode<HeapObject> receiver,
+TNode<Map> CodeStubAssembler::CheckEnumCache(TNode<JSReceiver> receiver,
                                              Label* if_empty,
                                              Label* if_runtime) {
   Label if_fast(this), if_cache(this), if_no_cache(this, Label::kDeferred);
@@ -12916,7 +12974,7 @@ TNode<Map> CodeStubAssembler::CheckEnumCache(TNode<HeapObject> receiver,
     // Avoid runtime-call for empty dictionary receivers.
     GotoIfNot(IsDictionaryMap(receiver_map), if_runtime);
     TNode<HashTableBase> properties =
-        UncheckedCast<HashTableBase>(LoadSlowProperties(CAST(receiver)));
+        UncheckedCast<HashTableBase>(LoadSlowProperties(receiver));
     CSA_ASSERT(this, Word32Or(IsNameDictionary(properties),
                               IsGlobalDictionary(properties)));
     STATIC_ASSERT(static_cast<int>(NameDictionary::kNumberOfElementsIndex) ==
@@ -13018,6 +13076,62 @@ void CodeStubAssembler::InitializeSyntheticFunctionContext(
                                     UndefinedConstant());
 }
 
+TNode<Object> CodeStubAssembler::CallApiCallback(
+    TNode<Object> context, TNode<RawPtrT> callback, TNode<IntPtrT> argc,
+    TNode<Object> data, TNode<Object> holder, TNode<Object> receiver) {
+  Callable callable = CodeFactory::CallApiCallback(isolate());
+  return CallStub(callable, context, callback, argc, data, holder, receiver);
+}
+
+TNode<Object> CodeStubAssembler::CallApiCallback(
+    TNode<Object> context, TNode<RawPtrT> callback, TNode<IntPtrT> argc,
+    TNode<Object> data, TNode<Object> holder, TNode<Object> receiver,
+    TNode<Object> value) {
+  // CallApiCallback receives the first four arguments in registers
+  // (callback, argc, data and holder). The last arguments are in the stack in
+  // JS ordering. See ApiCallbackDescriptor.
+  Callable callable = CodeFactory::CallApiCallback(isolate());
+#ifdef V8_REVERSE_JSARGS
+  return CallStub(callable, context, callback, argc, data, holder, value,
+                  receiver);
+#else
+  return CallStub(callable, context, callback, argc, data, holder, receiver,
+                  value);
+#endif
+}
+
+TNode<Object> CodeStubAssembler::CallRuntimeNewArray(
+    TNode<Context> context, TNode<Object> receiver, TNode<Object> length,
+    TNode<Object> new_target, TNode<Object> allocation_site) {
+  // Runtime_NewArray receives arguments in the JS order (to avoid unnecessary
+  // copy). Except the last two (new_target and allocation_site) which are add
+  // on top of the stack later.
+#ifdef V8_REVERSE_JSARGS
+  return CallRuntime(Runtime::kNewArray, context, length, receiver, new_target,
+                     allocation_site);
+#else
+  return CallRuntime(Runtime::kNewArray, context, receiver, length, new_target,
+                     allocation_site);
+#endif
+}
+
+void CodeStubAssembler::TailCallRuntimeNewArray(TNode<Context> context,
+                                                TNode<Object> receiver,
+                                                TNode<Object> length,
+                                                TNode<Object> new_target,
+                                                TNode<Object> allocation_site) {
+  // Runtime_NewArray receives arguments in the JS order (to avoid unnecessary
+  // copy). Except the last two (new_target and allocation_site) which are add
+  // on top of the stack later.
+#ifdef V8_REVERSE_JSARGS
+  return TailCallRuntime(Runtime::kNewArray, context, length, receiver,
+                         new_target, allocation_site);
+#else
+  return TailCallRuntime(Runtime::kNewArray, context, receiver, length,
+                         new_target, allocation_site);
+#endif
+}
+
 TNode<JSArray> CodeStubAssembler::ArrayCreate(TNode<Context> context,
                                               TNode<Number> length) {
   TVARIABLE(JSArray, array);
@@ -13040,8 +13154,8 @@ TNode<JSArray> CodeStubAssembler::ArrayCreate(TNode<Context> context,
     TNode<NativeContext> native_context = LoadNativeContext(context);
     TNode<JSFunction> array_function =
         CAST(LoadContextElement(native_context, Context::ARRAY_FUNCTION_INDEX));
-    array = CAST(CallRuntime(Runtime::kNewArray, context, array_function,
-                             length, array_function, UndefinedConstant()));
+    array = CAST(CallRuntimeNewArray(context, array_function, length,
+                                     array_function, UndefinedConstant()));
     Goto(&done);
   }
 
diff --git a/deps/v8/src/codegen/code-stub-assembler.h b/deps/v8/src/codegen/code-stub-assembler.h
index 6eb9baef69..618481ff47 100644
--- a/deps/v8/src/codegen/code-stub-assembler.h
+++ b/deps/v8/src/codegen/code-stub-assembler.h
@@ -18,6 +18,7 @@
 #include "src/objects/promise.h"
 #include "src/objects/shared-function-info.h"
 #include "src/objects/smi.h"
+#include "src/objects/tagged-index.h"
 #include "src/roots/roots.h"
 
 #include "torque-generated/exported-macros-assembler-tq.h"
@@ -52,6 +53,9 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(TypedArraySpeciesProtector, typed_array_species_protector,                \
     TypedArraySpeciesProtector)
 
+#define TORQUE_INTERNAL_CLASS_LIST_CSA_ADAPTER(V, NAME, Name, name) \
+  V(Name##Map, name##_map, Name##Map)
+
 #define HEAP_IMMUTABLE_IMMOVABLE_OBJECT_LIST(V)                                \
   V(AccessorInfoMap, accessor_info_map, AccessorInfoMap)                       \
   V(AccessorPairMap, accessor_pair_map, AccessorPairMap)                       \
@@ -71,6 +75,7 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(ConsOneByteStringMap, cons_one_byte_string_map, ConsOneByteStringMap)      \
   V(ConsStringMap, cons_string_map, ConsStringMap)                             \
   V(constructor_string, constructor_string, ConstructorString)                 \
+  V(CoverageInfoMap, coverage_info_map, CoverageInfoMap)                       \
   V(date_to_string, date_to_string, DateToString)                              \
   V(default_string, default_string, DefaultString)                             \
   V(EmptyByteArray, empty_byte_array, EmptyByteArray)                          \
@@ -172,7 +177,9 @@ enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };
   V(UndefinedValue, undefined_value, Undefined)                                \
   V(uninitialized_symbol, uninitialized_symbol, UninitializedSymbol)           \
   V(WeakFixedArrayMap, weak_fixed_array_map, WeakFixedArrayMap)                \
-  V(zero_string, zero_string, ZeroString)
+  V(zero_string, zero_string, ZeroString)                                      \
+  TORQUE_INTERNAL_CLASS_LIST_GENERATOR(TORQUE_INTERNAL_CLASS_LIST_CSA_ADAPTER, \
+                                       V)
 
 #define HEAP_IMMOVABLE_OBJECT_LIST(V)   \
   HEAP_MUTABLE_IMMOVABLE_OBJECT_LIST(V) \
@@ -273,6 +280,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
       public TorqueGeneratedExportedMacrosAssembler {
  public:
   using Node = compiler::Node;
+  using ScopedExceptionHandler = compiler::ScopedExceptionHandler;
 
   template <typename T>
   using LazyNode = std::function<TNode<T>()>;
@@ -384,6 +392,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 #error Unknown architecture.
 #endif
 
+  TNode<IntPtrT> TaggedIndexToIntPtr(TNode<TaggedIndex> value);
+  TNode<TaggedIndex> IntPtrToTaggedIndex(TNode<IntPtrT> value);
+  // TODO(v8:10047): Get rid of these convertions eventually.
+  TNode<Smi> TaggedIndexToSmi(TNode<TaggedIndex> value);
+  TNode<TaggedIndex> SmiToTaggedIndex(TNode<Smi> value);
+
   // Pointer compression specific. Returns true if the upper 32 bits of a Smi
   // contain the sign of a lower 32 bits (i.e. not corrupted) so that the Smi
   // can be directly used as an index in element offset computation.
@@ -878,6 +892,25 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                         callable, receiver, args...));
   }
 
+  TNode<Object> CallApiCallback(TNode<Object> context, TNode<RawPtrT> callback,
+                                TNode<IntPtrT> argc, TNode<Object> data,
+                                TNode<Object> holder, TNode<Object> receiver);
+
+  TNode<Object> CallApiCallback(TNode<Object> context, TNode<RawPtrT> callback,
+                                TNode<IntPtrT> argc, TNode<Object> data,
+                                TNode<Object> holder, TNode<Object> receiver,
+                                TNode<Object> value);
+
+  TNode<Object> CallRuntimeNewArray(TNode<Context> context,
+                                    TNode<Object> receiver,
+                                    TNode<Object> length,
+                                    TNode<Object> new_target,
+                                    TNode<Object> allocation_site);
+
+  void TailCallRuntimeNewArray(TNode<Context> context, TNode<Object> receiver,
+                               TNode<Object> length, TNode<Object> new_target,
+                               TNode<Object> allocation_site);
+
   template <class... TArgs>
   TNode<JSReceiver> ConstructWithTarget(TNode<Context> context,
                                         TNode<JSReceiver> target,
@@ -1036,9 +1069,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<Object> LoadFromParentFrame(int offset);
 
   // Load an object pointer from a buffer that isn't in the heap.
-  template <typename T = Object>
-  TNode<T> LoadBufferObject(TNode<RawPtrT> buffer, int offset) {
-    return CAST(Load(MachineTypeOf<T>::value, buffer, IntPtrConstant(offset)));
+  TNode<Object> LoadBufferObject(TNode<RawPtrT> buffer, int offset) {
+    return LoadFullTagged(buffer, IntPtrConstant(offset));
   }
   template <typename T>
   TNode<T> LoadBufferData(TNode<RawPtrT> buffer, int offset) {
@@ -1049,7 +1081,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
     return LoadBufferData<RawPtrT>(buffer, offset);
   }
   TNode<Smi> LoadBufferSmi(TNode<RawPtrT> buffer, int offset) {
-    return LoadBufferObject<Smi>(buffer, offset);
+    return CAST(LoadBufferObject(buffer, offset));
   }
   // Load a field from an object on the heap.
   template <class T, typename std::enable_if<
@@ -1625,12 +1657,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                   CheckBounds::kDebugOnly);
   }
 
-  void StoreFixedArrayOrPropertyArrayElement(
-      Node* array, Node* index, Node* value,
-      WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
-      int additional_offset = 0,
-      ParameterMode parameter_mode = INTPTR_PARAMETERS);
-
   void StoreFixedArrayElement(
       TNode<FixedArray> array, Node* index, SloppyTNode<Object> value,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
@@ -1741,8 +1767,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                     Label* bailout);
 
   void TryStoreArrayElement(ElementsKind kind, ParameterMode mode,
-                            Label* bailout, Node* elements, Node* index,
-                            Node* value);
+                            Label* bailout, TNode<FixedArrayBase> elements,
+                            Node* index, TNode<Object> value);
   // Consumes args into the array, and returns tagged new length.
   TNode<Smi> BuildAppendJSArray(ElementsKind kind, TNode<JSArray> array,
                                 CodeStubArguments* args,
@@ -1939,7 +1965,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                           Label* if_bailout);
   TNode<Object> GetConstructor(TNode<Map> map);
 
-  TNode<Map> GetStructMap(InstanceType instance_type);
+  TNode<Map> GetInstanceTypeMap(InstanceType instance_type);
 
   TNode<FixedArray> AllocateUninitializedFixedArray(intptr_t capacity) {
     return UncheckedCast<FixedArray>(AllocateFixedArray(
@@ -1981,9 +2007,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
     return result;
   }
 
-  Node* AllocatePropertyArray(Node* capacity,
-                              ParameterMode mode = INTPTR_PARAMETERS,
-                              AllocationFlags flags = kNone);
+  TNode<PropertyArray> AllocatePropertyArray(
+      Node* capacity, ParameterMode mode = INTPTR_PARAMETERS,
+      AllocationFlags flags = kNone);
 
   // Perform CreateArrayIterator (ES #sec-createarrayiterator).
   TNode<JSArrayIterator> CreateArrayIterator(TNode<Context> context,
@@ -2004,8 +2030,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                        TNode<Object> originalArray,
                                        TNode<Number> len);
 
-  void FillFixedArrayWithValue(ElementsKind kind, Node* array, Node* from_index,
-                               Node* to_index, RootIndex value_root_index,
+  void FillFixedArrayWithValue(ElementsKind kind, TNode<FixedArrayBase> array,
+                               Node* from_index, Node* to_index,
+                               RootIndex value_root_index,
                                ParameterMode mode = INTPTR_PARAMETERS);
 
   // Uses memset to effectively initialize the given FixedArray with zeroes.
@@ -2014,18 +2041,33 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   void FillFixedDoubleArrayWithZero(TNode<FixedDoubleArray> array,
                                     TNode<IntPtrT> length);
 
-  void FillPropertyArrayWithUndefined(Node* array, Node* from_index,
-                                      Node* to_index,
+  void FillPropertyArrayWithUndefined(TNode<PropertyArray> array,
+                                      Node* from_index, Node* to_index,
                                       ParameterMode mode = INTPTR_PARAMETERS);
 
   enum class DestroySource { kNo, kYes };
 
   // Collect the callable |maybe_target| feedback for either a CALL_IC or
-  // an INSTANCEOF_IC in the |feedback_vector| at |slot_id|.
+  // an INSTANCEOF_IC in the |feedback_vector| at |slot_id|. There are
+  // two modes for feedback collection:
+  //
+  //   kCollectFeedbackCell -     collect JSFunctions, but devolve to the
+  //                              FeedbackCell as long as all JSFunctions
+  //                              seen share the same one.
+  //   kDontCollectFeedbackCell - collect JSFunctions without devolving
+  //                              to the FeedbackCell in case a
+  //                              different JSFunction appears. Go directly
+  //                              to the Megamorphic sentinel value in this
+  //                              case.
+  enum class CallableFeedbackMode {
+    kCollectFeedbackCell,
+    kDontCollectFeedbackCell
+  };
   void CollectCallableFeedback(TNode<Object> maybe_target,
                                TNode<Context> context,
                                TNode<FeedbackVector> feedback_vector,
-                               TNode<UintPtrT> slot_id);
+                               TNode<UintPtrT> slot_id,
+                               CallableFeedbackMode mode);
 
   // Collect CALL_IC feedback for |maybe_target| function in the
   // |feedback_vector| at |slot_id|, and the call counts in
@@ -2046,7 +2088,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // Otherwise, specify DestroySource::kNo for operations where an Object is
   // being cloned, to ensure that mutable HeapNumbers are unique between the
   // source and cloned object.
-  void CopyPropertyArrayValues(Node* from_array, Node* to_array, Node* length,
+  void CopyPropertyArrayValues(TNode<HeapObject> from_array,
+                               TNode<PropertyArray> to_array, Node* length,
                                WriteBarrierMode barrier_mode,
                                ParameterMode mode,
                                DestroySource destroy_source);
@@ -2054,7 +2097,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // Copies all elements from |from_array| of |length| size to
   // |to_array| of the same size respecting the elements kind.
   void CopyFixedArrayElements(
-      ElementsKind kind, Node* from_array, Node* to_array, Node* length,
+      ElementsKind kind, TNode<FixedArrayBase> from_array,
+      TNode<FixedArrayBase> to_array, Node* length,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
       ParameterMode mode = INTPTR_PARAMETERS) {
     CopyFixedArrayElements(kind, from_array, kind, to_array,
@@ -2066,9 +2110,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // zero to |to_array| of |capacity| size respecting both array's elements
   // kinds.
   void CopyFixedArrayElements(
-      ElementsKind from_kind, TNode<Object> from_array, ElementsKind to_kind,
-      TNode<Object> to_array, TNode<IntPtrT> element_count,
-      TNode<IntPtrT> capacity,
+      ElementsKind from_kind, TNode<FixedArrayBase> from_array,
+      ElementsKind to_kind, TNode<FixedArrayBase> to_array,
+      TNode<IntPtrT> element_count, TNode<IntPtrT> capacity,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
       ParameterMode mode = INTPTR_PARAMETERS) {
     CopyFixedArrayElements(from_kind, from_array, to_kind, to_array,
@@ -2085,8 +2129,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // HoleConversionMode::kConvertToUndefined, then it must not be the case that
   // IsDoubleElementsKind(to_kind).
   void CopyFixedArrayElements(
-      ElementsKind from_kind, Node* from_array, ElementsKind to_kind,
-      Node* to_array, Node* first_element, Node* element_count, Node* capacity,
+      ElementsKind from_kind, TNode<FixedArrayBase> from_array,
+      ElementsKind to_kind, TNode<FixedArrayBase> to_array, Node* first_element,
+      Node* element_count, Node* capacity,
       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
       ParameterMode mode = INTPTR_PARAMETERS,
       HoleConversionMode convert_holes = HoleConversionMode::kDontConvert,
@@ -2187,13 +2232,13 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // runtime elements kind of source to make copy faster. More specifically, it
   // can skip write barriers.
   TNode<FixedArrayBase> ExtractFixedArray(
-      Node* source, Node* first, Node* count = nullptr,
+      TNode<FixedArrayBase> source, Node* first, Node* count = nullptr,
       Node* capacity = nullptr,
       ExtractFixedArrayFlags extract_flags =
           ExtractFixedArrayFlag::kAllFixedArrays,
       ParameterMode parameter_mode = INTPTR_PARAMETERS,
       TVariable<BoolT>* var_holes_converted = nullptr,
-      Node* source_elements_kind = nullptr);
+      base::Optional<TNode<Int32T>> source_elements_kind = base::nullopt);
 
   TNode<FixedArrayBase> ExtractFixedArray(
       TNode<FixedArrayBase> source, TNode<Smi> first, TNode<Smi> count,
@@ -2250,7 +2295,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
       ParameterMode parameter_mode = INTPTR_PARAMETERS,
       HoleConversionMode convert_holes = HoleConversionMode::kDontConvert,
       TVariable<BoolT>* var_holes_converted = nullptr,
-      Node* source_runtime_kind = nullptr);
+      base::Optional<TNode<Int32T>> source_runtime_kind = base::nullopt);
 
   // Attempt to copy a FixedDoubleArray to another FixedDoubleArray. In the case
   // where the source array has a hole, produce a FixedArray instead where holes
@@ -2271,8 +2316,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // * |parameter_mode| determines the parameter mode of |first|, |count| and
   // |capacity|.
   TNode<FixedArrayBase> ExtractFixedDoubleArrayFillingHoles(
-      Node* source, Node* first, Node* count, Node* capacity, Node* source_map,
-      TVariable<BoolT>* var_holes_converted, AllocationFlags allocation_flags,
+      TNode<FixedArrayBase> source, Node* first, Node* count, Node* capacity,
+      TNode<Map> source_map, TVariable<BoolT>* var_holes_converted,
+      AllocationFlags allocation_flags,
       ExtractFixedArrayFlags extract_flags =
           ExtractFixedArrayFlag::kAllFixedArrays,
       ParameterMode parameter_mode = INTPTR_PARAMETERS);
@@ -2318,34 +2364,34 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 
   // Tries to grow the |elements| array of given |object| to store the |key|
   // or bails out if the growing gap is too big. Returns new elements.
-  TNode<FixedArrayBase> TryGrowElementsCapacity(Node* object, Node* elements,
-                                                ElementsKind kind, Node* key,
-                                                Label* bailout);
+  TNode<FixedArrayBase> TryGrowElementsCapacity(TNode<HeapObject> object,
+                                                TNode<FixedArrayBase> elements,
+                                                ElementsKind kind,
+                                                TNode<Smi> key, Label* bailout);
 
   // Tries to grow the |capacity|-length |elements| array of given |object|
   // to store the |key| or bails out if the growing gap is too big. Returns
   // new elements.
-  TNode<FixedArrayBase> TryGrowElementsCapacity(Node* object, Node* elements,
+  TNode<FixedArrayBase> TryGrowElementsCapacity(TNode<HeapObject> object,
+                                                TNode<FixedArrayBase> elements,
                                                 ElementsKind kind, Node* key,
                                                 Node* capacity,
                                                 ParameterMode mode,
                                                 Label* bailout);
 
   // Grows elements capacity of given object. Returns new elements.
-  TNode<FixedArrayBase> GrowElementsCapacity(Node* object, Node* elements,
-                                             ElementsKind from_kind,
-                                             ElementsKind to_kind,
-                                             Node* capacity, Node* new_capacity,
-                                             ParameterMode mode,
-                                             Label* bailout);
+  TNode<FixedArrayBase> GrowElementsCapacity(
+      TNode<HeapObject> object, TNode<FixedArrayBase> elements,
+      ElementsKind from_kind, ElementsKind to_kind, Node* capacity,
+      Node* new_capacity, ParameterMode mode, Label* bailout);
 
   // Given a need to grow by |growth|, allocate an appropriate new capacity
   // if necessary, and return a new elements FixedArray object. Label |bailout|
   // is followed for allocation failure.
   void PossiblyGrowElementsCapacity(ParameterMode mode, ElementsKind kind,
-                                    Node* array, Node* length,
-                                    Variable* var_elements, Node* growth,
-                                    Label* bailout);
+                                    TNode<HeapObject> array, Node* length,
+                                    TVariable<FixedArrayBase>* var_elements,
+                                    Node* growth, Label* bailout);
 
   // Allocation site manipulation
   void InitializeAllocationMemento(TNode<HeapObject> base,
@@ -2474,6 +2520,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BoolT> IsConsStringInstanceType(SloppyTNode<Int32T> instance_type);
   TNode<BoolT> IsConstructorMap(SloppyTNode<Map> map);
   TNode<BoolT> IsConstructor(SloppyTNode<HeapObject> object);
+  TNode<BoolT> IsCoverageInfo(TNode<HeapObject> object);
   TNode<BoolT> IsDebugInfo(TNode<HeapObject> object);
   TNode<BoolT> IsDeprecatedMap(SloppyTNode<Map> map);
   TNode<BoolT> IsNameDictionary(SloppyTNode<HeapObject> object);
@@ -2488,7 +2535,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BoolT> IsFixedArraySubclass(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsFixedArrayWithKind(SloppyTNode<HeapObject> object,
                                     ElementsKind kind);
-  TNode<BoolT> IsFixedArrayWithKindOrEmpty(SloppyTNode<HeapObject> object,
+  TNode<BoolT> IsFixedArrayWithKindOrEmpty(SloppyTNode<FixedArrayBase> object,
                                            ElementsKind kind);
   TNode<BoolT> IsFixedDoubleArray(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsFunctionWithPrototypeSlotMap(SloppyTNode<Map> map);
@@ -2583,6 +2630,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BoolT> IsInternalizedStringInstanceType(TNode<Int32T> instance_type);
   TNode<BoolT> IsUniqueName(TNode<HeapObject> object);
   TNode<BoolT> IsUniqueNameNoIndex(TNode<HeapObject> object);
+  TNode<BoolT> IsUniqueNameNoCachedIndex(TNode<HeapObject> object);
   TNode<BoolT> IsUndetectableMap(SloppyTNode<Map> map);
   TNode<BoolT> IsNotWeakFixedArraySubclass(SloppyTNode<HeapObject> object);
   TNode<BoolT> IsZeroOrContext(SloppyTNode<Object> object);
@@ -2637,7 +2685,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   // [0, 2^32-1).
   TNode<BoolT> IsNumberArrayIndex(TNode<Number> number);
 
-  Node* FixedArraySizeDoesntFitInNewSpace(
+  TNode<BoolT> FixedArraySizeDoesntFitInNewSpace(
       Node* element_count, int base_size = FixedArray::kHeaderSize,
       ParameterMode mode = INTPTR_PARAMETERS);
 
@@ -2725,23 +2773,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<JSReceiver> ToObject_Inline(TNode<Context> context,
                                     TNode<Object> input);
 
-  enum ToIntegerTruncationMode {
-    kNoTruncation,
-    kTruncateMinusZero,
-  };
-
   // ES6 7.1.15 ToLength, but with inlined fast path.
   TNode<Number> ToLength_Inline(SloppyTNode<Context> context,
                                 SloppyTNode<Object> input);
 
-  // ES6 7.1.4 ToInteger ( argument )
-  TNode<Number> ToInteger_Inline(SloppyTNode<Context> context,
-                                 SloppyTNode<Object> input,
-                                 ToIntegerTruncationMode mode = kNoTruncation);
-  TNode<Number> ToInteger(SloppyTNode<Context> context,
-                          SloppyTNode<Object> input,
-                          ToIntegerTruncationMode mode = kNoTruncation);
-
   // Returns a node that contains a decoded (unsigned!) value of a bit
   // field |BitField| in |word32|. Returns result as an uint32 node.
   template <typename BitField>
@@ -3091,9 +3126,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
            Label* bailout);
 
   // Tries to check if {object} has own {unique_name} property.
-  void TryHasOwnProperty(Node* object, Node* map, Node* instance_type,
-                         Node* unique_name, Label* if_found,
-                         Label* if_not_found, Label* if_bailout);
+  void TryHasOwnProperty(TNode<HeapObject> object, TNode<Map> map,
+                         TNode<Int32T> instance_type, TNode<Name> unique_name,
+                         Label* if_found, Label* if_not_found,
+                         Label* if_bailout);
 
   // Operating mode for TryGetOwnProperty and CallGetterIfAccessor
   // kReturnAccessorPair is used when we're only getting the property descriptor
@@ -3192,7 +3228,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   //
   // Note: this code does not check if the global dictionary points to deleted
   // entry! This has to be done by the caller.
-  void TryLookupProperty(SloppyTNode<JSReceiver> object, SloppyTNode<Map> map,
+  void TryLookupProperty(SloppyTNode<HeapObject> object, SloppyTNode<Map> map,
                          SloppyTNode<Int32T> instance_type,
                          SloppyTNode<Name> unique_name, Label* if_found_fast,
                          Label* if_found_dict, Label* if_found_global,
@@ -3350,8 +3386,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                              TNode<UintPtrT> length, TNode<IntPtrT> key,
                              Label* bailout);
 
-  Node* CopyElementsOnWrite(Node* object, Node* elements, ElementsKind kind,
-                            Node* length, ParameterMode mode, Label* bailout);
+  TNode<FixedArrayBase> CopyElementsOnWrite(TNode<HeapObject> object,
+                                            TNode<FixedArrayBase> elements,
+                                            ElementsKind kind, Node* length,
+                                            ParameterMode mode, Label* bailout);
 
   void TransitionElementsKind(TNode<JSObject> object, TNode<Map> map,
                               ElementsKind from_kind, ElementsKind to_kind,
@@ -3558,7 +3596,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<Uint32T> LoadJSArrayBufferBitField(TNode<JSArrayBuffer> array_buffer);
   TNode<RawPtrT> LoadJSArrayBufferBackingStore(
       TNode<JSArrayBuffer> array_buffer);
-  TNode<BoolT> IsDetachedBuffer(TNode<JSArrayBuffer> buffer);
   void ThrowIfArrayBufferIsDetached(SloppyTNode<Context> context,
                                     TNode<JSArrayBuffer> array_buffer,
                                     const char* method_name);
@@ -3611,9 +3648,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BoolT> IsPromiseHookEnabledOrDebugIsActiveOrHasAsyncEventDelegate();
 
   // for..in helpers
-  void CheckPrototypeEnumCache(Node* receiver, Node* receiver_map,
-                               Label* if_fast, Label* if_slow);
-  TNode<Map> CheckEnumCache(TNode<HeapObject> receiver, Label* if_empty,
+  void CheckPrototypeEnumCache(TNode<JSReceiver> receiver,
+                               TNode<Map> receiver_map, Label* if_fast,
+                               Label* if_slow);
+  TNode<Map> CheckEnumCache(TNode<JSReceiver> receiver, Label* if_empty,
                             Label* if_runtime);
 
   TNode<Object> GetArgumentValue(TorqueStructArguments args,
@@ -3635,8 +3673,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
     STATIC_ASSERT(sizeof...(TArgs) <= 3);
     const TNode<Object> make_type_error = LoadContextElement(
         LoadNativeContext(context), Context::MAKE_TYPE_ERROR_INDEX);
-    return CAST(CallJS(CodeFactory::Call(isolate()), context, make_type_error,
-                       UndefinedConstant(), SmiConstant(message), args...));
+    return CAST(Call(context, make_type_error, UndefinedConstant(),
+                     SmiConstant(message), args...));
   }
 
   void Abort(AbortReason reason) {
@@ -3649,6 +3687,8 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   bool ConstexprInt31Equal(int31_t a, int31_t b) { return a == b; }
   bool ConstexprInt31NotEqual(int31_t a, int31_t b) { return a != b; }
   bool ConstexprInt31GreaterThanEqual(int31_t a, int31_t b) { return a >= b; }
+  bool ConstexprInt32Equal(int32_t a, int32_t b) { return a == b; }
+  bool ConstexprInt32NotEqual(int32_t a, int32_t b) { return a != b; }
   bool ConstexprInt32GreaterThanEqual(int32_t a, int32_t b) { return a >= b; }
   uint32_t ConstexprUint32Add(uint32_t a, uint32_t b) { return a + b; }
   int31_t ConstexprInt31Add(int31_t a, int31_t b) {
@@ -3892,6 +3932,12 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<Object> LoadRoot(RootIndex root_index) {
     return CodeAssembler::LoadRoot(root_index);
   }
+
+  void StoreFixedArrayOrPropertyArrayElement(
+      TNode<UnionT<FixedArray, PropertyArray>> array, Node* index,
+      TNode<Object> value, WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
+      int additional_offset = 0,
+      ParameterMode parameter_mode = INTPTR_PARAMETERS);
 };
 
 // template <typename TIndex>
diff --git a/deps/v8/src/codegen/compiler.cc b/deps/v8/src/codegen/compiler.cc
index 04e80f5a6e..595e59f551 100644
--- a/deps/v8/src/codegen/compiler.cc
+++ b/deps/v8/src/codegen/compiler.cc
@@ -11,12 +11,14 @@
 #include "src/asmjs/asm-js.h"
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopes.h"
+#include "src/base/logging.h"
 #include "src/base/optional.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/compilation-cache.h"
 #include "src/codegen/optimized-compilation-info.h"
 #include "src/codegen/pending-optimization-table.h"
 #include "src/codegen/unoptimized-compilation-info.h"
+#include "src/common/assert-scope.h"
 #include "src/common/globals.h"
 #include "src/common/message-template.h"
 #include "src/compiler-dispatcher/compiler-dispatcher.h"
@@ -24,16 +26,22 @@
 #include "src/compiler/pipeline.h"
 #include "src/debug/debug.h"
 #include "src/debug/liveedit.h"
+#include "src/diagnostics/code-tracer.h"
 #include "src/execution/frames-inl.h"
 #include "src/execution/isolate-inl.h"
+#include "src/execution/isolate.h"
 #include "src/execution/runtime-profiler.h"
 #include "src/execution/vm-state-inl.h"
+#include "src/handles/maybe-handles.h"
 #include "src/heap/heap-inl.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/init/bootstrapper.h"
 #include "src/interpreter/interpreter.h"
 #include "src/logging/log-inl.h"
 #include "src/objects/feedback-cell-inl.h"
 #include "src/objects/map.h"
+#include "src/objects/object-list-macros.h"
+#include "src/objects/shared-function-info.h"
 #include "src/parsing/parse-info.h"
 #include "src/parsing/parser.h"
 #include "src/parsing/parsing.h"
@@ -161,6 +169,16 @@ CompilationJob::Status UnoptimizedCompilationJob::FinalizeJob(
   return UpdateState(FinalizeJobImpl(shared_info, isolate), State::kSucceeded);
 }
 
+CompilationJob::Status UnoptimizedCompilationJob::FinalizeJob(
+    Handle<SharedFunctionInfo> shared_info, OffThreadIsolate* isolate) {
+  DisallowHeapAccess no_heap_access;
+
+  // Delegate to the underlying implementation.
+  DCHECK_EQ(state(), State::kReadyToFinalize);
+  ScopedTimer t(&time_taken_to_finalize_);
+  return UpdateState(FinalizeJobImpl(shared_info, isolate), State::kSucceeded);
+}
+
 void UnoptimizedCompilationJob::RecordCompilationStats(Isolate* isolate) const {
   int code_size;
   if (compilation_info()->has_bytecode_array()) {
@@ -208,7 +226,8 @@ CompilationJob::Status OptimizedCompilationJob::PrepareJob(Isolate* isolate) {
   DisallowJavascriptExecution no_js(isolate);
 
   if (FLAG_trace_opt && compilation_info()->IsOptimizing()) {
-    StdoutStream os;
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    OFStream os(scope.file());
     os << "[compiling method " << Brief(*compilation_info()->closure())
        << " using " << compiler_name_;
     if (compilation_info()->is_osr()) os << " OSR";
@@ -262,10 +281,11 @@ void OptimizedCompilationJob::RecordCompilationStats(CompilationMode mode,
   double ms_optimize = time_taken_to_execute_.InMillisecondsF();
   double ms_codegen = time_taken_to_finalize_.InMillisecondsF();
   if (FLAG_trace_opt) {
-    PrintF("[optimizing ");
-    function->ShortPrint();
-    PrintF(" - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph, ms_optimize,
-           ms_codegen);
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    PrintF(scope.file(), "[optimizing ");
+    function->ShortPrint(scope.file());
+    PrintF(scope.file(), " - took %0.3f, %0.3f, %0.3f ms]\n", ms_creategraph,
+           ms_optimize, ms_codegen);
   }
   if (FLAG_trace_opt_stats) {
     static double compilation_time = 0.0;
@@ -442,9 +462,40 @@ void InstallUnoptimizedCode(UnoptimizedCompilationInfo* compilation_info,
   }
 }
 
+void InstallUnoptimizedCode(UnoptimizedCompilationInfo* compilation_info,
+                            Handle<SharedFunctionInfo> shared_info,
+                            ParseInfo* parse_info, OffThreadIsolate* isolate) {
+  DCHECK_EQ(shared_info->language_mode(),
+            compilation_info->literal()->language_mode());
+
+  // Update the shared function info with the scope info.
+  Handle<ScopeInfo> scope_info = compilation_info->scope()->scope_info();
+  shared_info->set_scope_info(*scope_info);
+
+  DCHECK(compilation_info->has_bytecode_array());
+  DCHECK(!shared_info->HasBytecodeArray());  // Only compiled once.
+  DCHECK(!compilation_info->has_asm_wasm_data());
+  DCHECK(!shared_info->HasFeedbackMetadata());
+
+  // If the function failed asm-wasm compilation, mark asm_wasm as broken
+  // to ensure we don't try to compile as asm-wasm.
+  if (compilation_info->literal()->scope()->IsAsmModule()) {
+    shared_info->set_is_asm_wasm_broken(true);
+  }
+
+  shared_info->set_bytecode_array(*compilation_info->bytecode_array());
+
+  Handle<FeedbackMetadata> feedback_metadata =
+      FeedbackMetadata::New(isolate, compilation_info->feedback_vector_spec());
+  shared_info->set_feedback_metadata(*feedback_metadata);
+
+  DCHECK(!compilation_info->has_coverage_info());
+}
+
+template <typename LocalIsolate>
 void EnsureSharedFunctionInfosArrayOnScript(Handle<Script> script,
                                             ParseInfo* parse_info,
-                                            Isolate* isolate) {
+                                            LocalIsolate* isolate) {
   DCHECK(parse_info->is_toplevel());
   if (script->shared_function_infos().length() > 0) {
     DCHECK_EQ(script->shared_function_infos().length(),
@@ -452,21 +503,25 @@ void EnsureSharedFunctionInfosArrayOnScript(Handle<Script> script,
     return;
   }
   Handle<WeakFixedArray> infos(isolate->factory()->NewWeakFixedArray(
-      parse_info->max_function_literal_id() + 1));
+      parse_info->max_function_literal_id() + 1, AllocationType::kOld));
   script->set_shared_function_infos(*infos);
 }
 
 void SetSharedFunctionFlagsFromLiteral(FunctionLiteral* literal,
-                                       Handle<SharedFunctionInfo> shared_info) {
-  shared_info->set_has_duplicate_parameters(
-      literal->has_duplicate_parameters());
-  shared_info->set_is_oneshot_iife(literal->is_oneshot_iife());
-  shared_info->UpdateAndFinalizeExpectedNofPropertiesFromEstimate(literal);
+                                       SharedFunctionInfo shared_info) {
+  shared_info.set_has_duplicate_parameters(literal->has_duplicate_parameters());
+  shared_info.set_is_oneshot_iife(literal->is_oneshot_iife());
+  shared_info.UpdateAndFinalizeExpectedNofPropertiesFromEstimate(literal);
   if (literal->dont_optimize_reason() != BailoutReason::kNoReason) {
-    shared_info->DisableOptimization(literal->dont_optimize_reason());
+    shared_info.DisableOptimization(literal->dont_optimize_reason());
   }
-  shared_info->set_is_safe_to_skip_arguments_adaptor(
+
+  shared_info.set_class_scope_has_private_brand(
+      literal->class_scope_has_private_brand());
+  shared_info.set_is_safe_to_skip_arguments_adaptor(
       literal->SafeToSkipArgumentsAdaptor());
+  shared_info.set_has_static_private_methods_or_accessors(
+      literal->has_static_private_methods_or_accessors());
 }
 
 CompilationJob::Status FinalizeUnoptimizedCompilationJob(
@@ -475,7 +530,7 @@ CompilationJob::Status FinalizeUnoptimizedCompilationJob(
   UnoptimizedCompilationInfo* compilation_info = job->compilation_info();
   ParseInfo* parse_info = job->parse_info();
 
-  SetSharedFunctionFlagsFromLiteral(compilation_info->literal(), shared_info);
+  SetSharedFunctionFlagsFromLiteral(compilation_info->literal(), *shared_info);
 
   CompilationJob::Status status = job->FinalizeJob(shared_info, isolate);
   if (status == CompilationJob::SUCCEEDED) {
@@ -485,7 +540,8 @@ CompilationJob::Status FinalizeUnoptimizedCompilationJob(
     // background compile was started in which the compiled bytecode will not be
     // missing source positions (for instance by enabling the cpu profiler). So
     // force source position collection now in that case.
-    if (isolate->NeedsDetailedOptimizedCodeLineInfo()) {
+    if (!parse_info->collect_source_positions() &&
+        isolate->NeedsDetailedOptimizedCodeLineInfo()) {
       SharedFunctionInfo::EnsureSourcePositionsAvailable(isolate, shared_info);
     }
 
@@ -503,6 +559,23 @@ CompilationJob::Status FinalizeUnoptimizedCompilationJob(
   return status;
 }
 
+CompilationJob::Status FinalizeUnoptimizedCompilationJob(
+    UnoptimizedCompilationJob* job, Handle<SharedFunctionInfo> shared_info,
+    OffThreadIsolate* isolate) {
+  UnoptimizedCompilationInfo* compilation_info = job->compilation_info();
+  ParseInfo* parse_info = job->parse_info();
+
+  SetSharedFunctionFlagsFromLiteral(compilation_info->literal(), *shared_info);
+
+  CompilationJob::Status status = job->FinalizeJob(shared_info, isolate);
+  if (status == CompilationJob::SUCCEEDED) {
+    InstallUnoptimizedCode(compilation_info, shared_info, parse_info, isolate);
+
+    // TODO(leszeks): Record the function compilation and compilation stats.
+  }
+  return status;
+}
+
 std::unique_ptr<UnoptimizedCompilationJob> ExecuteUnoptimizedCompileJobs(
     ParseInfo* parse_info, FunctionLiteral* literal,
     AccountingAllocator* allocator,
@@ -564,7 +637,7 @@ MaybeHandle<SharedFunctionInfo> GenerateUnoptimizedCodeForToplevel(
     Isolate* isolate, Handle<Script> script, ParseInfo* parse_info,
     AccountingAllocator* allocator, IsCompiledScope* is_compiled_scope) {
   EnsureSharedFunctionInfosArrayOnScript(script, parse_info, isolate);
-  parse_info->ast_value_factory()->Internalize(isolate->factory());
+  parse_info->ast_value_factory()->Internalize(isolate);
 
   if (!Compiler::Analyze(parse_info)) return MaybeHandle<SharedFunctionInfo>();
   DeclarationScope::AllocateScopeInfos(parse_info, isolate);
@@ -629,12 +702,14 @@ MaybeHandle<SharedFunctionInfo> GenerateUnoptimizedCodeForToplevel(
   return top_level;
 }
 
+template <typename LocalIsolate>
 bool FinalizeUnoptimizedCode(
-    ParseInfo* parse_info, Isolate* isolate,
+    ParseInfo* parse_info, LocalIsolate* isolate,
     Handle<SharedFunctionInfo> shared_info,
     UnoptimizedCompilationJob* outer_function_job,
     UnoptimizedCompilationJobList* inner_function_jobs) {
-  DCHECK(AllowCompilation::IsAllowed(isolate));
+  // TODO(leszeks): Re-enable.
+  // DCHECK(AllowCompilation::IsAllowed(isolate));
 
   // TODO(rmcilroy): Clear native context in debug once AsmJS generates doesn't
   // rely on accessing native context during finalization.
@@ -649,6 +724,7 @@ bool FinalizeUnoptimizedCode(
   }
 
   Handle<Script> script(Script::cast(shared_info->script()), isolate);
+  parse_info->CheckFlagsForFunctionFromScript(*script);
 
   // Finalize the inner functions' compilation jobs.
   for (auto&& inner_job : *inner_function_jobs) {
@@ -752,9 +828,10 @@ bool GetOptimizedCodeNow(OptimizedCompilationJob* job, Isolate* isolate) {
           CompilationJob::SUCCEEDED ||
       job->FinalizeJob(isolate) != CompilationJob::SUCCEEDED) {
     if (FLAG_trace_opt) {
-      PrintF("[aborted optimizing ");
-      compilation_info->closure()->ShortPrint();
-      PrintF(" because: %s]\n",
+      CodeTracer::Scope scope(isolate->GetCodeTracer());
+      PrintF(scope.file(), "[aborted optimizing ");
+      compilation_info->closure()->ShortPrint(scope.file());
+      PrintF(scope.file(), " because: %s]\n",
              GetBailoutReason(compilation_info->bailout_reason()));
     }
     return false;
@@ -838,12 +915,13 @@ MaybeHandle<Code> GetOptimizedCode(Handle<JSFunction> function,
   if (GetCodeFromOptimizedCodeCache(function, osr_offset)
           .ToHandle(&cached_code)) {
     if (FLAG_trace_opt) {
-      PrintF("[found optimized code for ");
-      function->ShortPrint();
+      CodeTracer::Scope scope(isolate->GetCodeTracer());
+      PrintF(scope.file(), "[found optimized code for ");
+      function->ShortPrint(scope.file());
       if (!osr_offset.IsNone()) {
-        PrintF(" at OSR AST id %d", osr_offset.ToInt());
+        PrintF(scope.file(), " at OSR AST id %d", osr_offset.ToInt());
       }
-      PrintF("]\n");
+      PrintF(scope.file(), "]\n");
     }
     return cached_code;
   }
@@ -932,6 +1010,13 @@ bool FailWithPendingException(Isolate* isolate, Handle<Script> script,
   return false;
 }
 
+bool FailWithPendingException(OffThreadIsolate* isolate, Handle<Script> script,
+                              ParseInfo* parse_info,
+                              Compiler::ClearExceptionFlag flag) {
+  // TODO(leszeks): Implement.
+  UNREACHABLE();
+}
+
 void FinalizeScriptCompilation(Isolate* isolate, Handle<Script> script,
                                ParseInfo* parse_info) {
   script->set_compilation_state(Script::COMPILATION_STATE_COMPILED);
@@ -954,12 +1039,19 @@ void FinalizeScriptCompilation(Isolate* isolate, Handle<Script> script,
   }
 }
 
+void FinalizeScriptCompilation(OffThreadIsolate* isolate, Handle<Script> script,
+                               ParseInfo* parse_info) {
+  script->set_compilation_state(Script::COMPILATION_STATE_COMPILED);
+  DCHECK(!parse_info->parallel_tasks());
+}
+
+template <typename LocalIsolate>
 MaybeHandle<SharedFunctionInfo> FinalizeTopLevel(
-    ParseInfo* parse_info, Handle<Script> script, Isolate* isolate,
+    ParseInfo* parse_info, Handle<Script> script, LocalIsolate* isolate,
     UnoptimizedCompilationJob* outer_function_job,
     UnoptimizedCompilationJobList* inner_function_jobs) {
   // Internalize ast values onto the heap.
-  parse_info->ast_value_factory()->Internalize(isolate->factory());
+  parse_info->ast_value_factory()->Internalize(isolate);
 
   // Create shared function infos for top level and shared function infos array
   // for inner functions.
@@ -984,7 +1076,8 @@ MaybeHandle<SharedFunctionInfo> FinalizeTopLevel(
 }
 
 MaybeHandle<SharedFunctionInfo> CompileToplevel(
-    ParseInfo* parse_info, Handle<Script> script, Isolate* isolate,
+    ParseInfo* parse_info, Handle<Script> script,
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info, Isolate* isolate,
     IsCompiledScope* is_compiled_scope) {
   TimerEventScope<TimerEventCompileCode> top_level_timer(isolate);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileCode");
@@ -997,7 +1090,8 @@ MaybeHandle<SharedFunctionInfo> CompileToplevel(
                                      : RuntimeCallCounterId::kCompileScript);
   VMState<BYTECODE_COMPILER> state(isolate);
   if (parse_info->literal() == nullptr &&
-      !parsing::ParseProgram(parse_info, script, isolate)) {
+      !parsing::ParseProgram(parse_info, script, maybe_outer_scope_info,
+                             isolate)) {
     return MaybeHandle<SharedFunctionInfo>();
   }
   // Measure how long it takes to do the compilation; only take the
@@ -1044,34 +1138,43 @@ std::unique_ptr<UnoptimizedCompilationJob> CompileOnBackgroundThread(
   return outer_function_job;
 }
 
+MaybeHandle<SharedFunctionInfo> CompileToplevel(
+    ParseInfo* parse_info, Handle<Script> script, Isolate* isolate,
+    IsCompiledScope* is_compiled_scope) {
+  return CompileToplevel(parse_info, script, kNullMaybeHandle, isolate,
+                         is_compiled_scope);
+}
+
 }  // namespace
 
 BackgroundCompileTask::BackgroundCompileTask(ScriptStreamingData* streamed_data,
                                              Isolate* isolate)
     : info_(new ParseInfo(isolate)),
+      off_thread_isolate_(FLAG_finalize_streaming_on_background
+                              ? new OffThreadIsolate(isolate, info_->zone())
+                              : nullptr),
       stack_size_(i::FLAG_stack_size),
       worker_thread_runtime_call_stats_(
           isolate->counters()->worker_thread_runtime_call_stats()),
       allocator_(isolate->allocator()),
-      timer_(isolate->counters()->compile_script_on_background()) {
+      timer_(isolate->counters()->compile_script_on_background()),
+      collected_source_positions_(false) {
   VMState<PARSER> state(isolate);
 
   // Prepare the data for the internalization phase and compilation phase, which
   // will happen in the main thread after parsing.
   LOG(isolate, ScriptEvent(Logger::ScriptEventType::kStreamingCompile,
                            info_->script_id()));
-  info_->set_toplevel();
-  info_->set_allow_lazy_parsing();
-  if (V8_UNLIKELY(info_->block_coverage_enabled())) {
-    info_->AllocateSourceRangeMap();
-  }
-  LanguageMode language_mode = construct_language_mode(FLAG_use_strict);
-  info_->set_language_mode(
-      stricter_language_mode(info_->language_mode(), language_mode));
+  info_->SetFlagsForToplevelCompile(isolate->is_collecting_type_profile(), true,
+                                    construct_language_mode(FLAG_use_strict),
+                                    REPLMode::kNo);
+  language_mode_ = info_->language_mode();
 
   std::unique_ptr<Utf16CharacterStream> stream(ScannerStream::For(
       streamed_data->source_stream.get(), streamed_data->encoding));
   info_->set_character_stream(std::move(stream));
+
+  finalize_on_background_thread_ = FLAG_finalize_streaming_on_background;
 }
 
 BackgroundCompileTask::BackgroundCompileTask(
@@ -1084,7 +1187,10 @@ BackgroundCompileTask::BackgroundCompileTask(
       stack_size_(max_stack_size),
       worker_thread_runtime_call_stats_(worker_thread_runtime_stats),
       allocator_(allocator),
-      timer_(timer) {
+      timer_(timer),
+      language_mode_(info_->language_mode()),
+      collected_source_positions_(false),
+      finalize_on_background_thread_(false) {
   DCHECK(outer_parse_info->is_toplevel());
   DCHECK(!function_literal->is_toplevel());
 
@@ -1124,6 +1230,7 @@ class OffThreadParseInfoScope {
   }
 
   ~OffThreadParseInfoScope() {
+    DCHECK_NOT_NULL(parse_info_);
     parse_info_->set_stack_limit(original_stack_limit_);
     parse_info_->set_runtime_call_stats(original_runtime_call_stats_);
   }
@@ -1145,8 +1252,9 @@ void BackgroundCompileTask::Run() {
   DisallowHeapAccess no_heap_access;
 
   TimedHistogramScope timer(timer_);
-  OffThreadParseInfoScope off_thread_scope(
-      info_.get(), worker_thread_runtime_call_stats_, stack_size_);
+  base::Optional<OffThreadParseInfoScope> off_thread_scope(
+      base::in_place, info_.get(), worker_thread_runtime_call_stats_,
+      stack_size_);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "BackgroundCompileTask::Run");
   RuntimeCallTimerScope runtimeTimer(
@@ -1167,6 +1275,52 @@ void BackgroundCompileTask::Run() {
     // Parsing has succeeded, compile.
     outer_function_job_ = CompileOnBackgroundThread(info_.get(), allocator_,
                                                     &inner_function_jobs_);
+    // Save the language mode and record whether we collected source positions.
+    language_mode_ = info_->language_mode();
+    collected_source_positions_ = info_->collect_source_positions();
+
+    if (finalize_on_background_thread_) {
+      DCHECK(info_->is_toplevel());
+
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                   "V8.FinalizeCodeBackground");
+
+      off_thread_isolate_->PinToCurrentThread();
+
+      OffThreadHandleScope handle_scope(off_thread_isolate_.get());
+
+      // We don't have the script source or the script origin yet, so use a few
+      // default values for them. These will be fixed up during the main-thread
+      // merge.
+      Handle<Script> script =
+          info_->CreateScript(off_thread_isolate_.get(),
+                              off_thread_isolate_->factory()->empty_string(),
+                              ScriptOriginOptions(), NOT_NATIVES_CODE);
+
+      Handle<SharedFunctionInfo> outer_function_sfi =
+          FinalizeTopLevel(info_.get(), script, off_thread_isolate_.get(),
+                           outer_function_job_.get(), &inner_function_jobs_)
+              .ToHandleChecked();
+
+      parser_->HandleSourceURLComments(off_thread_isolate_.get(), script);
+
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                   "V8.FinalizeCodeBackground.Finish");
+      off_thread_isolate_->FinishOffThread();
+
+      // Off-thread handles will become invalid after the handle scope closes,
+      // so save the raw object here.
+      outer_function_sfi_ = *outer_function_sfi;
+
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                   "V8.FinalizeCodeBackground.ReleaseParser");
+      DCHECK_EQ(language_mode_, info_->language_mode());
+      off_thread_scope.reset();
+      parser_.reset();
+      info_.reset();
+      outer_function_job_.reset();
+      inner_function_jobs_.clear();
+    }
   }
 }
 
@@ -1357,7 +1511,7 @@ bool Compiler::Compile(Handle<SharedFunctionInfo> shared_info,
   }
 
   // Internalize ast values onto the heap.
-  parse_info.ast_value_factory()->Internalize(isolate->factory());
+  parse_info.ast_value_factory()->Internalize(isolate);
 
   // Finalize compilation of the unoptimized bytecode or asm-js data.
   if (!FinalizeUnoptimizedCode(&parse_info, isolate, shared_info,
@@ -1422,9 +1576,10 @@ bool Compiler::Compile(Handle<JSFunction> function, ClearExceptionFlag flag,
   // Optimize now if --always-opt is enabled.
   if (FLAG_always_opt && !function->shared().HasAsmWasmData()) {
     if (FLAG_trace_opt) {
-      PrintF("[optimizing ");
-      function->ShortPrint();
-      PrintF(" because --always-opt]\n");
+      CodeTracer::Scope scope(isolate->GetCodeTracer());
+      PrintF(scope.file(), "[optimizing ");
+      function->ShortPrint(scope.file());
+      PrintF(scope.file(), " because --always-opt]\n");
     }
     Handle<Code> opt_code;
     if (GetOptimizedCode(function, ConcurrencyMode::kNotConcurrent)
@@ -1456,9 +1611,7 @@ bool Compiler::FinalizeBackgroundCompileTask(
   DCHECK(!shared_info->is_compiled());
 
   Handle<Script> script(Script::cast(shared_info->script()), isolate);
-  // TODO(leszeks): We can probably remove this, the parse_info flags should
-  // already match the script's.
-  parse_info->SetFlagsFromScript(isolate, *script);
+  parse_info->CheckFlagsForFunctionFromScript(*script);
 
   task->parser()->UpdateStatistics(isolate, script);
   task->parser()->HandleSourceURLComments(isolate, script);
@@ -1469,7 +1622,7 @@ bool Compiler::FinalizeBackgroundCompileTask(
   }
 
   // Parsing has succeeded - finalize compilation.
-  parse_info->ast_value_factory()->Internalize(isolate->factory());
+  parse_info->ast_value_factory()->Internalize(isolate);
   if (!FinalizeUnoptimizedCode(parse_info, isolate, shared_info,
                                task->outer_function_job(),
                                task->inner_function_jobs())) {
@@ -1565,9 +1718,21 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
     allow_eval_cache = true;
   } else {
     ParseInfo parse_info(isolate);
+    parse_info.SetFlagsForToplevelCompile(isolate->is_collecting_type_profile(),
+                                          true, language_mode, REPLMode::kNo);
+
+    parse_info.set_eval();
+    parse_info.set_parse_restriction(restriction);
+    parse_info.set_parameters_end_pos(parameters_end_pos);
+    DCHECK(!parse_info.is_module());
+
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info;
+    if (!context->IsNativeContext()) {
+      maybe_outer_scope_info = handle(context->scope_info(), isolate);
+    }
+
     script = parse_info.CreateScript(
         isolate, source, OriginOptionsForEval(outer_info->script()));
-    script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
     script->set_eval_from_shared(*outer_info);
     if (eval_position == kNoSourcePosition) {
       // If the position is missing, attempt to get the code offset by
@@ -1586,16 +1751,8 @@ MaybeHandle<JSFunction> Compiler::GetFunctionFromEval(
     }
     script->set_eval_from_position(eval_position);
 
-    parse_info.set_eval();
-    parse_info.set_language_mode(language_mode);
-    parse_info.set_parse_restriction(restriction);
-    parse_info.set_parameters_end_pos(parameters_end_pos);
-    if (!context->IsNativeContext()) {
-      parse_info.set_outer_scope_info(handle(context->scope_info(), isolate));
-    }
-    DCHECK(!parse_info.is_module());
-
-    if (!CompileToplevel(&parse_info, script, isolate, &is_compiled_scope)
+    if (!CompileToplevel(&parse_info, script, maybe_outer_scope_info, isolate,
+                         &is_compiled_scope)
              .ToHandle(&shared_info)) {
       return MaybeHandle<JSFunction>();
     }
@@ -1981,32 +2138,51 @@ struct ScriptCompileTimerScope {
   }
 };
 
-Handle<Script> NewScript(Isolate* isolate, ParseInfo* parse_info,
-                         Handle<String> source,
-                         Compiler::ScriptDetails script_details,
-                         ScriptOriginOptions origin_options,
-                         NativesFlag natives) {
-  // Create a script object describing the script to be compiled.
-  Handle<Script> script = parse_info->CreateScript(
-      isolate, source, origin_options, script_details.repl_mode, natives);
+void SetScriptFieldsFromDetails(Script script,
+                                Compiler::ScriptDetails script_details) {
   Handle<Object> script_name;
   if (script_details.name_obj.ToHandle(&script_name)) {
-    script->set_name(*script_name);
-    script->set_line_offset(script_details.line_offset);
-    script->set_column_offset(script_details.column_offset);
+    script.set_name(*script_name);
+    script.set_line_offset(script_details.line_offset);
+    script.set_column_offset(script_details.column_offset);
   }
   Handle<Object> source_map_url;
   if (script_details.source_map_url.ToHandle(&source_map_url)) {
-    script->set_source_mapping_url(*source_map_url);
+    script.set_source_mapping_url(*source_map_url);
   }
   Handle<FixedArray> host_defined_options;
   if (script_details.host_defined_options.ToHandle(&host_defined_options)) {
-    script->set_host_defined_options(*host_defined_options);
+    script.set_host_defined_options(*host_defined_options);
   }
+}
+
+Handle<Script> NewScript(Isolate* isolate, ParseInfo* parse_info,
+                         Handle<String> source,
+                         Compiler::ScriptDetails script_details,
+                         ScriptOriginOptions origin_options,
+                         NativesFlag natives) {
+  // Create a script object describing the script to be compiled.
+  Handle<Script> script =
+      parse_info->CreateScript(isolate, source, origin_options, natives);
+  SetScriptFieldsFromDetails(*script, script_details);
   LOG(isolate, ScriptDetails(*script));
   return script;
 }
 
+void FixUpOffThreadAllocatedScript(Isolate* isolate, Handle<Script> script,
+                                   Handle<String> source,
+                                   Compiler::ScriptDetails script_details,
+                                   ScriptOriginOptions origin_options,
+                                   NativesFlag natives) {
+  DisallowHeapAllocation no_gc;
+  DCHECK_EQ(natives, NOT_NATIVES_CODE);
+  DCHECK_EQ(script_details.repl_mode, REPLMode::kNo);
+  script->set_origin_options(origin_options);
+  script->set_source(*source);
+  SetScriptFieldsFromDetails(*script, script_details);
+  LOG(isolate, ScriptDetails(*script));
+}
+
 }  // namespace
 
 MaybeHandle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
@@ -2077,19 +2253,24 @@ MaybeHandle<SharedFunctionInfo> Compiler::GetSharedFunctionInfoForScript(
   }
 
   if (maybe_result.is_null()) {
-    ParseInfo parse_info(isolate);
     // No cache entry found compile the script.
+    ParseInfo parse_info(isolate);
+
+    parse_info.SetFlagsForToplevelCompile(
+        isolate->is_collecting_type_profile(), natives == NOT_NATIVES_CODE,
+        language_mode, script_details.repl_mode);
+
+    parse_info.set_module(origin_options.IsModule());
+    parse_info.set_extension(extension);
+    parse_info.set_eager(compile_options == ScriptCompiler::kEagerCompile);
+
     Handle<Script> script = NewScript(isolate, &parse_info, source,
                                       script_details, origin_options, natives);
+    DCHECK_IMPLIES(parse_info.collect_type_profile(),
+                   script->IsUserJavaScript());
     DCHECK_EQ(parse_info.is_repl_mode(), script->is_repl_mode());
 
     // Compile the function and add it to the isolate cache.
-    if (origin_options.IsModule()) parse_info.set_module();
-    parse_info.set_extension(extension);
-    parse_info.set_eager(compile_options == ScriptCompiler::kEagerCompile);
-
-    parse_info.set_language_mode(
-        stricter_language_mode(parse_info.language_mode(), language_mode));
     maybe_result =
         CompileToplevel(&parse_info, script, isolate, &is_compiled_scope);
     Handle<SharedFunctionInfo> result;
@@ -2151,27 +2332,30 @@ MaybeHandle<JSFunction> Compiler::GetWrappedFunction(
   IsCompiledScope is_compiled_scope;
   if (!maybe_result.ToHandle(&wrapped)) {
     ParseInfo parse_info(isolate);
-    script = NewScript(isolate, &parse_info, source, script_details,
-                       origin_options, NOT_NATIVES_CODE);
-    script->set_wrapped_arguments(*arguments);
+    parse_info.SetFlagsForToplevelCompile(isolate->is_collecting_type_profile(),
+                                          true, language_mode,
+                                          script_details.repl_mode);
 
     parse_info.set_eval();  // Use an eval scope as declaration scope.
     parse_info.set_function_syntax_kind(FunctionSyntaxKind::kWrapped);
-    parse_info.set_wrapped_arguments(arguments);
     // TODO(delphick): Remove this and instead make the wrapped and wrapper
     // functions fully non-lazy instead thus preventing source positions from
     // being omitted.
     parse_info.set_collect_source_positions(true);
     // parse_info.set_eager(compile_options == ScriptCompiler::kEagerCompile);
+
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info;
     if (!context->IsNativeContext()) {
-      parse_info.set_outer_scope_info(handle(context->scope_info(), isolate));
+      maybe_outer_scope_info = handle(context->scope_info(), isolate);
     }
-    parse_info.set_language_mode(
-        stricter_language_mode(parse_info.language_mode(), language_mode));
+
+    script = NewScript(isolate, &parse_info, source, script_details,
+                       origin_options, NOT_NATIVES_CODE);
+    script->set_wrapped_arguments(*arguments);
 
     Handle<SharedFunctionInfo> top_level;
-    maybe_result =
-        CompileToplevel(&parse_info, script, isolate, &is_compiled_scope);
+    maybe_result = CompileToplevel(&parse_info, script, maybe_outer_scope_info,
+                                   isolate, &is_compiled_scope);
     if (maybe_result.is_null()) isolate->ReportPendingMessages();
     ASSIGN_RETURN_ON_EXCEPTION(isolate, top_level, maybe_result, JSFunction);
 
@@ -2208,59 +2392,107 @@ Compiler::GetSharedFunctionInfoForStreamedScript(
   isolate->counters()->total_compile_size()->Increment(source_length);
 
   BackgroundCompileTask* task = streaming_data->task.get();
-  ParseInfo* parse_info = task->info();
-  DCHECK(parse_info->is_toplevel());
+
+  MaybeHandle<SharedFunctionInfo> maybe_result;
   // Check if compile cache already holds the SFI, if so no need to finalize
   // the code compiled on the background thread.
   CompilationCache* compilation_cache = isolate->compilation_cache();
-  MaybeHandle<SharedFunctionInfo> maybe_result =
-      compilation_cache->LookupScript(
-          source, script_details.name_obj, script_details.line_offset,
-          script_details.column_offset, origin_options,
-          isolate->native_context(), parse_info->language_mode());
-  if (!maybe_result.is_null()) {
-    compile_timer.set_hit_isolate_cache();
+  {
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                 "V8.StreamingFinalization.CheckCache");
+    maybe_result = compilation_cache->LookupScript(
+        source, script_details.name_obj, script_details.line_offset,
+        script_details.column_offset, origin_options, isolate->native_context(),
+        task->language_mode());
+    if (!maybe_result.is_null()) {
+      compile_timer.set_hit_isolate_cache();
+    }
   }
 
   if (maybe_result.is_null()) {
-    // No cache entry found, finalize compilation of the script and add it to
-    // the isolate cache.
-    Handle<Script> script =
-        NewScript(isolate, parse_info, source, script_details, origin_options,
-                  NOT_NATIVES_CODE);
-    task->parser()->UpdateStatistics(isolate, script);
-    task->parser()->HandleSourceURLComments(isolate, script);
-
-    if (parse_info->literal() == nullptr || !task->outer_function_job()) {
-      // Parsing has failed - report error messages.
-      FailWithPendingException(isolate, script, parse_info,
-                               Compiler::ClearExceptionFlag::KEEP_EXCEPTION);
+    if (task->finalize_on_background_thread()) {
+      RuntimeCallTimerScope runtimeTimerScope(
+          isolate, RuntimeCallCounterId::kCompilePublishBackgroundFinalization);
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                   "V8.OffThreadFinalization.Publish");
+
+      Handle<SharedFunctionInfo> sfi(task->outer_function_sfi(), isolate);
+      Handle<Script> script(Script::cast(sfi->script()), isolate);
+      task->off_thread_isolate()->factory()->Publish(isolate);
+
+      FixUpOffThreadAllocatedScript(isolate, script, source, script_details,
+                                    origin_options, NOT_NATIVES_CODE);
+
+      // It's possible that source position collection was enabled after the
+      // background compile was started (for instance by enabling the cpu
+      // profiler), and the compiled bytecode is missing source positions. So,
+      // walk all the SharedFunctionInfos in the script and force source
+      // position collection.
+      if (!task->collected_source_positions() &&
+          isolate->NeedsDetailedOptimizedCodeLineInfo()) {
+        Handle<WeakFixedArray> shared_function_infos(
+            script->shared_function_infos(isolate), isolate);
+        int length = shared_function_infos->length();
+        FOR_WITH_HANDLE_SCOPE(isolate, int, i = 0, i, i < length, i++, {
+          Object entry = shared_function_infos->Get(isolate, i)
+                             .GetHeapObjectOrSmi(isolate);
+          if (entry.IsSharedFunctionInfo(isolate)) {
+            SharedFunctionInfo::EnsureSourcePositionsAvailable(
+                isolate, handle(SharedFunctionInfo::cast(entry), isolate));
+          }
+        });
+      }
+
+      maybe_result = sfi;
     } else {
-      // Parsing has succeeded - finalize compilation.
-      maybe_result = FinalizeTopLevel(parse_info, script, isolate,
-                                      task->outer_function_job(),
-                                      task->inner_function_jobs());
-      if (maybe_result.is_null()) {
-        // Finalization failed - throw an exception.
+      ParseInfo* parse_info = task->info();
+      DCHECK(parse_info->is_toplevel());
+
+      // No cache entry found, finalize compilation of the script and add it to
+      // the isolate cache.
+      Handle<Script> script =
+          NewScript(isolate, parse_info, source, script_details, origin_options,
+                    NOT_NATIVES_CODE);
+      task->parser()->UpdateStatistics(isolate, script);
+      task->parser()->HandleSourceURLComments(isolate, script);
+
+      if (parse_info->literal() == nullptr || !task->outer_function_job()) {
+        // Parsing has failed - report error messages.
         FailWithPendingException(isolate, script, parse_info,
                                  Compiler::ClearExceptionFlag::KEEP_EXCEPTION);
+      } else {
+        // Parsing has succeeded - finalize compilation.
+        maybe_result = FinalizeTopLevel(parse_info, script, isolate,
+                                        task->outer_function_job(),
+                                        task->inner_function_jobs());
+        if (maybe_result.is_null()) {
+          // Finalization failed - throw an exception.
+          FailWithPendingException(
+              isolate, script, parse_info,
+              Compiler::ClearExceptionFlag::KEEP_EXCEPTION);
+        }
       }
     }
 
     // Add compiled code to the isolate cache.
     Handle<SharedFunctionInfo> result;
     if (maybe_result.ToHandle(&result)) {
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                   "V8.StreamingFinalization.AddToCache");
       compilation_cache->PutScript(source, isolate->native_context(),
-                                   parse_info->language_mode(), result);
+                                   task->language_mode(), result);
     }
   }
 
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.StreamingFinalization.Release");
   streaming_data->Release();
   return maybe_result;
 }
 
+template <typename LocalIsolate>
 Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
-    FunctionLiteral* literal, Handle<Script> script, Isolate* isolate) {
+    FunctionLiteral* literal, Handle<Script> script, LocalIsolate* isolate) {
   // Precondition: code has been parsed and scopes have been analyzed.
   MaybeHandle<SharedFunctionInfo> maybe_existing;
 
@@ -2303,6 +2535,11 @@ Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
   return result;
 }
 
+template Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
+    FunctionLiteral* literal, Handle<Script> script, Isolate* isolate);
+template Handle<SharedFunctionInfo> Compiler::GetSharedFunctionInfo(
+    FunctionLiteral* literal, Handle<Script> script, OffThreadIsolate* isolate);
+
 MaybeHandle<Code> Compiler::GetOptimizedCodeForOSR(Handle<JSFunction> function,
                                                    BailoutId osr_offset,
                                                    JavaScriptFrame* osr_frame) {
@@ -2347,9 +2584,10 @@ bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
                                      isolate);
       InsertCodeIntoOptimizedCodeCache(compilation_info);
       if (FLAG_trace_opt) {
-        PrintF("[completed optimizing ");
-        compilation_info->closure()->ShortPrint();
-        PrintF("]\n");
+        CodeTracer::Scope scope(isolate->GetCodeTracer());
+        PrintF(scope.file(), "[completed optimizing ");
+        compilation_info->closure()->ShortPrint(scope.file());
+        PrintF(scope.file(), "]\n");
       }
       compilation_info->closure()->set_code(*compilation_info->code());
       return CompilationJob::SUCCEEDED;
@@ -2358,9 +2596,10 @@ bool Compiler::FinalizeOptimizedCompilationJob(OptimizedCompilationJob* job,
 
   DCHECK_EQ(job->state(), CompilationJob::State::kFailed);
   if (FLAG_trace_opt) {
-    PrintF("[aborted optimizing ");
-    compilation_info->closure()->ShortPrint();
-    PrintF(" because: %s]\n",
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    PrintF(scope.file(), "[aborted optimizing ");
+    compilation_info->closure()->ShortPrint(scope.file());
+    PrintF(scope.file(), " because: %s]\n",
            GetBailoutReason(compilation_info->bailout_reason()));
   }
   compilation_info->closure()->set_code(shared->GetCode());
diff --git a/deps/v8/src/codegen/compiler.h b/deps/v8/src/codegen/compiler.h
index 7747d1c074..7284003de9 100644
--- a/deps/v8/src/codegen/compiler.h
+++ b/deps/v8/src/codegen/compiler.h
@@ -10,10 +10,11 @@
 
 #include "src/base/platform/elapsed-timer.h"
 #include "src/codegen/bailout-reason.h"
+#include "src/common/globals.h"
 #include "src/execution/isolate.h"
 #include "src/logging/code-events.h"
-#include "src/utils/allocation.h"
 #include "src/objects/contexts.h"
+#include "src/utils/allocation.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
@@ -176,9 +177,9 @@ class V8_EXPORT_PRIVATE Compiler : public AllStatic {
 
   // Create a shared function info object for the given function literal
   // node (the code may be lazily compiled).
-  static Handle<SharedFunctionInfo> GetSharedFunctionInfo(FunctionLiteral* node,
-                                                          Handle<Script> script,
-                                                          Isolate* isolate);
+  template <typename LocalIsolate>
+  static Handle<SharedFunctionInfo> GetSharedFunctionInfo(
+      FunctionLiteral* node, Handle<Script> script, LocalIsolate* isolate);
 
   // ===========================================================================
   // The following family of methods provides support for OSR. Code generated
@@ -258,6 +259,10 @@ class UnoptimizedCompilationJob : public CompilationJob {
   V8_WARN_UNUSED_RESULT Status
   FinalizeJob(Handle<SharedFunctionInfo> shared_info, Isolate* isolate);
 
+  // Finalizes the compile job. Can be called on a background thread.
+  V8_WARN_UNUSED_RESULT Status FinalizeJob(
+      Handle<SharedFunctionInfo> shared_info, OffThreadIsolate* isolate);
+
   void RecordCompilationStats(Isolate* isolate) const;
   void RecordFunctionCompilation(CodeEventListener::LogEventsAndTags tag,
                                  Handle<SharedFunctionInfo> shared,
@@ -275,6 +280,8 @@ class UnoptimizedCompilationJob : public CompilationJob {
   virtual Status ExecuteJobImpl() = 0;
   virtual Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
                                  Isolate* isolate) = 0;
+  virtual Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
+                                 OffThreadIsolate* isolate) = 0;
 
  private:
   uintptr_t stack_limit_;
@@ -364,7 +371,10 @@ class V8_EXPORT_PRIVATE BackgroundCompileTask {
 
   void Run();
 
-  ParseInfo* info() { return info_.get(); }
+  ParseInfo* info() {
+    DCHECK_NOT_NULL(info_);
+    return info_.get();
+  }
   Parser* parser() { return parser_.get(); }
   UnoptimizedCompilationJob* outer_function_job() {
     return outer_function_job_.get();
@@ -372,6 +382,18 @@ class V8_EXPORT_PRIVATE BackgroundCompileTask {
   UnoptimizedCompilationJobList* inner_function_jobs() {
     return &inner_function_jobs_;
   }
+  LanguageMode language_mode() { return language_mode_; }
+  bool collected_source_positions() { return collected_source_positions_; }
+  bool finalize_on_background_thread() {
+    return finalize_on_background_thread_;
+  }
+  OffThreadIsolate* off_thread_isolate() { return off_thread_isolate_.get(); }
+  SharedFunctionInfo outer_function_sfi() {
+    // Make sure that this is an off-thread object, so that it won't have been
+    // moved by the GC.
+    DCHECK(Heap::InOffThreadSpace(outer_function_sfi_));
+    return outer_function_sfi_;
+  }
 
  private:
   // Data needed for parsing, and data needed to to be passed between thread
@@ -384,10 +406,27 @@ class V8_EXPORT_PRIVATE BackgroundCompileTask {
   std::unique_ptr<UnoptimizedCompilationJob> outer_function_job_;
   UnoptimizedCompilationJobList inner_function_jobs_;
 
+  // Data needed for merging onto the main thread after background finalization.
+  // TODO(leszeks): When these are available, the above fields are not. We
+  // should add some stricter type-safety or DCHECKs to ensure that the user of
+  // the task knows this.
+  std::unique_ptr<OffThreadIsolate> off_thread_isolate_;
+  // This is a raw pointer to the off-thread allocated SharedFunctionInfo.
+  SharedFunctionInfo outer_function_sfi_;
+
   int stack_size_;
   WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats_;
   AccountingAllocator* allocator_;
   TimedHistogram* timer_;
+  LanguageMode language_mode_;
+  bool collected_source_positions_;
+
+  // True if the background compilation should be finalized on the background
+  // thread. When this is true, the ParseInfo, Parser and compilation jobs are
+  // freed on the background thread, the outer_function_sfi holds the top-level
+  // function, and the off_thread_isolate has to be merged into the main-thread
+  // Isolate.
+  bool finalize_on_background_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundCompileTask);
 };
diff --git a/deps/v8/src/codegen/constant-pool.cc b/deps/v8/src/codegen/constant-pool.cc
index 42b2fa6e9a..1a676787df 100644
--- a/deps/v8/src/codegen/constant-pool.cc
+++ b/deps/v8/src/codegen/constant-pool.cc
@@ -9,7 +9,7 @@
 namespace v8 {
 namespace internal {
 
-#if defined(V8_TARGET_ARCH_PPC)
+#if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 ConstantPoolBuilder::ConstantPoolBuilder(int ptr_reach_bits,
                                          int double_reach_bits) {
@@ -209,7 +209,7 @@ int ConstantPoolBuilder::Emit(Assembler* assm) {
   return !empty ? (assm->pc_offset() - emitted_label_.pos()) : 0;
 }
 
-#endif  // defined(V8_TARGET_ARCH_PPC)
+#endif  // defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 #if defined(V8_TARGET_ARCH_ARM64)
 
diff --git a/deps/v8/src/codegen/constant-pool.h b/deps/v8/src/codegen/constant-pool.h
index d2ab5641ae..581644b917 100644
--- a/deps/v8/src/codegen/constant-pool.h
+++ b/deps/v8/src/codegen/constant-pool.h
@@ -81,7 +81,7 @@ class ConstantPoolEntry {
   enum { SHARING_PROHIBITED = -2, SHARING_ALLOWED = -1 };
 };
 
-#if defined(V8_TARGET_ARCH_PPC)
+#if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 // -----------------------------------------------------------------------------
 // Embedded constant pool support
@@ -161,7 +161,7 @@ class ConstantPoolBuilder {
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
-#endif  // defined(V8_TARGET_ARCH_PPC)
+#endif  // defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 #if defined(V8_TARGET_ARCH_ARM64)
 
diff --git a/deps/v8/src/codegen/constants-arch.h b/deps/v8/src/codegen/constants-arch.h
index b49d2b64f2..7a222c960f 100644
--- a/deps/v8/src/codegen/constants-arch.h
+++ b/deps/v8/src/codegen/constants-arch.h
@@ -15,7 +15,7 @@
 #include "src/codegen/mips/constants-mips.h"  // NOLINT
 #elif V8_TARGET_ARCH_MIPS64
 #include "src/codegen/mips64/constants-mips64.h"  // NOLINT
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/codegen/ppc/constants-ppc.h"  // NOLINT
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/constants-s390.h"  // NOLINT
diff --git a/deps/v8/src/codegen/cpu-features.h b/deps/v8/src/codegen/cpu-features.h
index 9ff38bc40b..14c94ebae9 100644
--- a/deps/v8/src/codegen/cpu-features.h
+++ b/deps/v8/src/codegen/cpu-features.h
@@ -47,7 +47,7 @@ enum CpuFeature {
   MIPSr6,
   MIPS_SIMD,  // MSA instructions
 
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
   FPU,
   FPR_GPR_MOV,
   LWSYNC,
diff --git a/deps/v8/src/codegen/external-reference.cc b/deps/v8/src/codegen/external-reference.cc
index 3bd2f299d1..7a42e40461 100644
--- a/deps/v8/src/codegen/external-reference.cc
+++ b/deps/v8/src/codegen/external-reference.cc
@@ -289,6 +289,7 @@ FUNCTION_REFERENCE(wasm_word32_rol, wasm::word32_rol_wrapper)
 FUNCTION_REFERENCE(wasm_word32_ror, wasm::word32_ror_wrapper)
 FUNCTION_REFERENCE(wasm_word64_rol, wasm::word64_rol_wrapper)
 FUNCTION_REFERENCE(wasm_word64_ror, wasm::word64_ror_wrapper)
+FUNCTION_REFERENCE(wasm_memory_init, wasm::memory_init_wrapper)
 FUNCTION_REFERENCE(wasm_memory_copy, wasm::memory_copy_wrapper)
 FUNCTION_REFERENCE(wasm_memory_fill, wasm::memory_fill_wrapper)
 
@@ -465,7 +466,7 @@ ExternalReference ExternalReference::invoke_accessor_getter_callback() {
 #define re_stack_check_func RegExpMacroAssemblerARM64::CheckStackGuardState
 #elif V8_TARGET_ARCH_ARM
 #define re_stack_check_func RegExpMacroAssemblerARM::CheckStackGuardState
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #define re_stack_check_func RegExpMacroAssemblerPPC::CheckStackGuardState
 #elif V8_TARGET_ARCH_MIPS
 #define re_stack_check_func RegExpMacroAssemblerMIPS::CheckStackGuardState
@@ -910,6 +911,11 @@ bool operator!=(ExternalReference lhs, ExternalReference rhs) {
 }
 
 size_t hash_value(ExternalReference reference) {
+  if (FLAG_predictable) {
+    // Avoid ASLR non-determinism in predictable mode. For this, just take the
+    // lowest 12 bit corresponding to a 4K page size.
+    return base::hash<Address>()(reference.address() & 0xfff);
+  }
   return base::hash<Address>()(reference.address());
 }
 
diff --git a/deps/v8/src/codegen/external-reference.h b/deps/v8/src/codegen/external-reference.h
index 9eb95e18d9..2c5c8348f4 100644
--- a/deps/v8/src/codegen/external-reference.h
+++ b/deps/v8/src/codegen/external-reference.h
@@ -200,6 +200,7 @@ class StatsCounter;
   V(wasm_word64_ror, "wasm::word64_ror")                                      \
   V(wasm_word64_ctz, "wasm::word64_ctz")                                      \
   V(wasm_word64_popcnt, "wasm::word64_popcnt")                                \
+  V(wasm_memory_init, "wasm::memory_init")                                    \
   V(wasm_memory_copy, "wasm::memory_copy")                                    \
   V(wasm_memory_fill, "wasm::memory_fill")                                    \
   V(call_enqueue_microtask_function, "MicrotaskQueue::CallEnqueueMicrotask")  \
diff --git a/deps/v8/src/codegen/ia32/assembler-ia32.h b/deps/v8/src/codegen/ia32/assembler-ia32.h
index 4cd713811b..246415ba67 100644
--- a/deps/v8/src/codegen/ia32/assembler-ia32.h
+++ b/deps/v8/src/codegen/ia32/assembler-ia32.h
@@ -1619,6 +1619,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   SSSE3_INSTRUCTION_LIST(DECLARE_SSSE3_INSTRUCTION)
+  SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSSE3_INSTRUCTION)
 #undef DECLARE_SSSE3_INSTRUCTION
 
 #define DECLARE_SSE4_INSTRUCTION(instruction, prefix, escape1, escape2,     \
@@ -1656,6 +1657,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     vinstr(0x##opcode, dst, xmm0, src, k##prefix, k##escape1##escape2, kW0);   \
   }
 
+  SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSE4_AVX_RM_INSTRUCTION)
   SSE4_RM_INSTRUCTION_LIST(DECLARE_SSE4_AVX_RM_INSTRUCTION)
 #undef DECLARE_SSE4_AVX_RM_INSTRUCTION
 
diff --git a/deps/v8/src/codegen/ia32/macro-assembler-ia32.cc b/deps/v8/src/codegen/ia32/macro-assembler-ia32.cc
index 4741cdb10d..6f5778d3ca 100644
--- a/deps/v8/src/codegen/ia32/macro-assembler-ia32.cc
+++ b/deps/v8/src/codegen/ia32/macro-assembler-ia32.cc
@@ -31,6 +31,20 @@
 namespace v8 {
 namespace internal {
 
+Operand StackArgumentsAccessor::GetArgumentOperand(int index) const {
+  DCHECK_GE(index, 0);
+#ifdef V8_REVERSE_JSARGS
+  // arg[0] = esp + kPCOnStackSize;
+  // arg[i] = arg[0] + i * kSystemPointerSize;
+  return Operand(esp, kPCOnStackSize + index * kSystemPointerSize);
+#else
+  // arg[0] = (esp + kPCOnStackSize) + argc * kSystemPointerSize;
+  // arg[i] = arg[0] - i * kSystemPointerSize;
+  return Operand(esp, argc_, times_system_pointer_size,
+                 kPCOnStackSize - index * kSystemPointerSize);
+#endif
+}
+
 // -------------------------------------------------------------------------
 // MacroAssembler implementation.
 
@@ -91,18 +105,6 @@ void TurboAssembler::CompareRoot(Register with, RootIndex index) {
   }
 }
 
-void TurboAssembler::CompareRealStackLimit(Register with) {
-  CHECK(root_array_available());  // Only used by builtins.
-
-  // Address through the root register. No load is needed.
-  ExternalReference limit =
-      ExternalReference::address_of_real_jslimit(isolate());
-  DCHECK(IsAddressableThroughRootRegister(isolate(), limit));
-
-  intptr_t offset = RootRegisterOffsetForExternalReference(isolate(), limit);
-  cmp(with, Operand(kRootRegister, offset));
-}
-
 void MacroAssembler::PushRoot(RootIndex index) {
   if (root_array_available()) {
     DCHECK(RootsTable::IsImmortalImmovable(index));
@@ -1107,9 +1109,14 @@ void MacroAssembler::CallDebugOnFunctionCall(Register fun, Register new_target,
   }
   Push(fun);
   Push(fun);
+  // Arguments are located 2 words below the base pointer.
+#ifdef V8_REVERSE_JSARGS
+  Operand receiver_op = Operand(ebp, kSystemPointerSize * 2);
+#else
   Operand receiver_op =
       Operand(ebp, actual_parameter_count, times_system_pointer_size,
               kSystemPointerSize * 2);
+#endif
   Push(receiver_op);
   CallRuntime(Runtime::kDebugOnFunctionCall);
   Pop(fun);
@@ -1776,32 +1783,38 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    // Find two caller-saved scratch registers.
-    Register scratch1 = eax;
-    Register scratch2 = ecx;
-    if (function == eax) scratch1 = edx;
-    if (function == ecx) scratch2 = edx;
-    PushPC();
-    pop(scratch1);
-    mov(ExternalReferenceAsOperand(
-            ExternalReference::fast_c_call_caller_pc_address(isolate()),
-            scratch2),
-        scratch1);
-    mov(ExternalReferenceAsOperand(
-            ExternalReference::fast_c_call_caller_fp_address(isolate()),
-            scratch2),
-        ebp);
-  }
+  // Find two caller-saved scratch registers.
+  Register pc_scratch = eax;
+  Register scratch = ecx;
+  if (function == eax) pc_scratch = edx;
+  if (function == ecx) scratch = edx;
+  PushPC();
+  pop(pc_scratch);
+
+  // See x64 code for reasoning about how to address the isolate data fields.
+  DCHECK_IMPLIES(!root_array_available(), isolate() != nullptr);
+  mov(root_array_available()
+          ? Operand(kRootRegister, IsolateData::fast_c_call_caller_pc_offset())
+          : ExternalReferenceAsOperand(
+                ExternalReference::fast_c_call_caller_pc_address(isolate()),
+                scratch),
+      pc_scratch);
+  mov(root_array_available()
+          ? Operand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset())
+          : ExternalReferenceAsOperand(
+                ExternalReference::fast_c_call_caller_fp_address(isolate()),
+                scratch),
+      ebp);
 
   call(function);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
-    mov(ExternalReferenceAsOperand(
-            ExternalReference::fast_c_call_caller_fp_address(isolate()), edx),
-        Immediate(0));
-  }
+  // We don't unset the PC; the FP is the source of truth.
+  mov(root_array_available()
+          ? Operand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset())
+          : ExternalReferenceAsOperand(
+                ExternalReference::fast_c_call_caller_fp_address(isolate()),
+                scratch),
+      Immediate(0));
 
   if (base::OS::ActivationFrameAlignment() != 0) {
     mov(esp, Operand(esp, num_arguments * kSystemPointerSize));
@@ -2028,7 +2041,9 @@ void TurboAssembler::ComputeCodeStartAddress(Register dst) {
   }
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
   // Save the deopt id in ebx (we don't need the roots array from now on).
   mov(ebx, deopt_id);
@@ -2036,6 +2051,7 @@ void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
 }
 
 void TurboAssembler::Trap() { int3(); }
+void TurboAssembler::DebugBreak() { int3(); }
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/codegen/ia32/macro-assembler-ia32.h b/deps/v8/src/codegen/ia32/macro-assembler-ia32.h
index 4d2ea96a92..40b542f375 100644
--- a/deps/v8/src/codegen/ia32/macro-assembler-ia32.h
+++ b/deps/v8/src/codegen/ia32/macro-assembler-ia32.h
@@ -24,6 +24,26 @@ using MemOperand = Operand;
 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
 
+// Convenient class to access arguments below the stack pointer.
+class StackArgumentsAccessor {
+ public:
+  // argc = the number of arguments not including the receiver.
+  explicit StackArgumentsAccessor(Register argc) : argc_(argc) {
+    DCHECK_NE(argc_, no_reg);
+  }
+
+  // Argument 0 is the receiver (despite argc not including the receiver).
+  Operand operator[](int index) const { return GetArgumentOperand(index); }
+
+  Operand GetArgumentOperand(int index) const;
+  Operand GetReceiverOperand() const { return GetArgumentOperand(0); }
+
+ private:
+  const Register argc_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(StackArgumentsAccessor);
+};
+
 class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
   using TurboAssemblerBase::TurboAssemblerBase;
@@ -108,8 +128,10 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void RetpolineJump(Register reg);
 
   void Trap() override;
+  void DebugBreak() override;
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   // Jump the register contains a smi.
   inline void JumpIfSmi(Register value, Label* smi_label,
@@ -215,7 +237,6 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void LoadAddress(Register destination, ExternalReference source);
 
-  void CompareRealStackLimit(Register with);
   void CompareRoot(Register with, RootIndex index);
   void CompareRoot(Register with, Register scratch, RootIndex index);
 
@@ -284,6 +305,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_OP3_XO(Packsswb, packsswb)
   AVX_OP3_XO(Packuswb, packuswb)
   AVX_OP3_XO(Paddusb, paddusb)
+  AVX_OP3_XO(Pand, pand)
   AVX_OP3_XO(Pcmpeqb, pcmpeqb)
   AVX_OP3_XO(Pcmpeqw, pcmpeqw)
   AVX_OP3_XO(Pcmpeqd, pcmpeqd)
@@ -335,8 +357,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_PACKED_OP3(Minpd, minpd)
   AVX_PACKED_OP3(Maxpd, maxpd)
   AVX_PACKED_OP3(Cmpunordpd, cmpunordpd)
+  AVX_PACKED_OP3(Psllw, psllw)
+  AVX_PACKED_OP3(Pslld, pslld)
   AVX_PACKED_OP3(Psllq, psllq)
+  AVX_PACKED_OP3(Psrlw, psrlw)
+  AVX_PACKED_OP3(Psrld, psrld)
   AVX_PACKED_OP3(Psrlq, psrlq)
+  AVX_PACKED_OP3(Psraw, psraw)
+  AVX_PACKED_OP3(Psrad, psrad)
   AVX_PACKED_OP3(Paddq, paddq)
   AVX_PACKED_OP3(Psubq, psubq)
   AVX_PACKED_OP3(Pmuludq, pmuludq)
@@ -344,7 +372,14 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_PACKED_OP3(Pavgw, pavgw)
 #undef AVX_PACKED_OP3
 
+  AVX_PACKED_OP3_WITH_TYPE(Psllw, psllw, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Pslld, pslld, XMMRegister, uint8_t)
   AVX_PACKED_OP3_WITH_TYPE(Psllq, psllq, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Psrlw, psrlw, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Psrld, psrld, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Psrlq, psrlq, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Psraw, psraw, XMMRegister, uint8_t)
+  AVX_PACKED_OP3_WITH_TYPE(Psrad, psrad, XMMRegister, uint8_t)
 #undef AVX_PACKED_OP3_WITH_TYPE
 
 // Non-SSE2 instructions.
@@ -369,6 +404,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_OP2_XO_SSE3(Movddup, movddup)
 
 #undef AVX_OP2_XO_SSE3
+
+#define AVX_OP2_XO_SSSE3(macro_name, name)                                   \
+  AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, XMMRegister, SSSE3) \
+  AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, Operand, SSSE3)
+  AVX_OP2_XO_SSSE3(Pabsb, pabsb)
+  AVX_OP2_XO_SSSE3(Pabsw, pabsw)
+  AVX_OP2_XO_SSSE3(Pabsd, pabsd)
+
+#undef AVX_OP2_XO_SSE3
+
 #define AVX_OP2_XO_SSE4(macro_name, name)                                     \
   AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, XMMRegister, SSE4_1) \
   AVX_OP2_WITH_TYPE_SCOPE(macro_name, name, XMMRegister, Operand, SSE4_1)
@@ -494,6 +539,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // TODO(860429): Remove remaining poisoning infrastructure on ia32.
   void ResetSpeculationPoisonRegister() { UNREACHABLE(); }
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
   void CallRecordWriteStub(Register object, Register address,
                            RememberedSetAction remembered_set_action,
                            SaveFPRegsMode fp_mode, Handle<Code> code_target,
diff --git a/deps/v8/src/codegen/ia32/sse-instr.h b/deps/v8/src/codegen/ia32/sse-instr.h
index c63b6aa3f3..b8a7a3c827 100644
--- a/deps/v8/src/codegen/ia32/sse-instr.h
+++ b/deps/v8/src/codegen/ia32/sse-instr.h
@@ -67,6 +67,12 @@
   V(psignw, 66, 0F, 38, 09)       \
   V(psignd, 66, 0F, 38, 0A)
 
+// SSSE3 instructions whose AVX version has two operands.
+#define SSSE3_UNOP_INSTRUCTION_LIST(V) \
+  V(pabsb, 66, 0F, 38, 1C)             \
+  V(pabsw, 66, 0F, 38, 1D)             \
+  V(pabsd, 66, 0F, 38, 1E)
+
 #define SSE4_INSTRUCTION_LIST(V) \
   V(packusdw, 66, 0F, 38, 2B)    \
   V(pminsb, 66, 0F, 38, 38)      \
diff --git a/deps/v8/src/codegen/interface-descriptors.cc b/deps/v8/src/codegen/interface-descriptors.cc
index 345c82454e..42b45c0f33 100644
--- a/deps/v8/src/codegen/interface-descriptors.cc
+++ b/deps/v8/src/codegen/interface-descriptors.cc
@@ -380,6 +380,18 @@ void WasmMemoryGrowDescriptor::InitializePlatformSpecific(
   DefaultInitializePlatformSpecific(data, kParameterCount);
 }
 
+void WasmTableInitDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  DefaultInitializePlatformSpecific(data,
+                                    kParameterCount - kStackArgumentsCount);
+}
+
+void WasmTableCopyDescriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  DefaultInitializePlatformSpecific(data,
+                                    kParameterCount - kStackArgumentsCount);
+}
+
 void WasmTableGetDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   DefaultInitializePlatformSpecific(data, kParameterCount);
@@ -401,12 +413,23 @@ void WasmAtomicNotifyDescriptor::InitializePlatformSpecific(
 }
 
 #if !defined(V8_TARGET_ARCH_MIPS) && !defined(V8_TARGET_ARCH_MIPS64)
-void WasmI32AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   DefaultInitializePlatformSpecific(data, kParameterCount);
 }
 
-void WasmI64AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait64Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  DefaultInitializePlatformSpecific(data, kParameterCount);
+}
+
+void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  DefaultInitializePlatformSpecific(data,
+                                    kParameterCount - kStackArgumentsCount);
+}
+
+void WasmI64AtomicWait64Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   DefaultInitializePlatformSpecific(data, kParameterCount);
 }
diff --git a/deps/v8/src/codegen/interface-descriptors.h b/deps/v8/src/codegen/interface-descriptors.h
index 0701c66be5..36099d57fe 100644
--- a/deps/v8/src/codegen/interface-descriptors.h
+++ b/deps/v8/src/codegen/interface-descriptors.h
@@ -91,9 +91,13 @@ namespace internal {
   V(Typeof)                           \
   V(Void)                             \
   V(WasmAtomicNotify)                 \
-  V(WasmI32AtomicWait)                \
-  V(WasmI64AtomicWait)                \
+  V(WasmI32AtomicWait32)              \
+  V(WasmI32AtomicWait64)              \
+  V(WasmI64AtomicWait32)              \
+  V(WasmI64AtomicWait64)              \
   V(WasmMemoryGrow)                   \
+  V(WasmTableInit)                    \
+  V(WasmTableCopy)                    \
   V(WasmTableGet)                     \
   V(WasmTableSet)                     \
   V(WasmThrow)                        \
@@ -454,18 +458,22 @@ STATIC_ASSERT(kMaxTFSBuiltinRegisterParams <= kMaxBuiltinRegisterParams);
   DEFINE_FLAGS_AND_RESULT_AND_PARAMETERS( \
       CallInterfaceDescriptorData::kAllowVarArgs, 1, ##__VA_ARGS__)
 
-#define DEFINE_RESULT_AND_PARAMETER_TYPES(...)                                 \
-  void InitializePlatformIndependent(CallInterfaceDescriptorData* data)        \
-      override {                                                               \
-    MachineType machine_types[] = {__VA_ARGS__};                               \
-    static_assert(                                                             \
-        kReturnCount + kParameterCount == arraysize(machine_types),            \
-        "Parameter names definition is not consistent with parameter types");  \
-    data->InitializePlatformIndependent(Flags(kDescriptorFlags), kReturnCount, \
-                                        kParameterCount, machine_types,        \
-                                        arraysize(machine_types));             \
+#define DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG(flag, ...)                \
+  void InitializePlatformIndependent(CallInterfaceDescriptorData* data)       \
+      override {                                                              \
+    MachineType machine_types[] = {__VA_ARGS__};                              \
+    static_assert(                                                            \
+        kReturnCount + kParameterCount == arraysize(machine_types),           \
+        "Parameter names definition is not consistent with parameter types"); \
+    data->InitializePlatformIndependent(                                      \
+        Flags(flag | kDescriptorFlags), kReturnCount, kParameterCount,        \
+        machine_types, arraysize(machine_types));                             \
   }
 
+#define DEFINE_RESULT_AND_PARAMETER_TYPES(...) \
+  DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG( \
+      CallInterfaceDescriptorData::kNoFlags, __VA_ARGS__)
+
 #define DEFINE_PARAMETER_TYPES(...)                                        \
   DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::AnyTagged() /* result */, \
                                     ##__VA_ARGS__)
@@ -1039,6 +1047,7 @@ class ArrayNoArgumentConstructorDescriptor
                      ArrayNArgumentsConstructorDescriptor)
 };
 
+#ifdef V8_REVERSE_JSARGS
 class ArraySingleArgumentConstructorDescriptor
     : public ArrayNArgumentsConstructorDescriptor {
  public:
@@ -1046,15 +1055,35 @@ class ArraySingleArgumentConstructorDescriptor
   // ArrayNArgumentsConstructorDescriptor and it declares indices for
   // JS arguments passed on the expression stack.
   DEFINE_PARAMETERS(kFunction, kAllocationSite, kActualArgumentsCount,
-                    kFunctionParameter, kArraySizeSmiParameter)
+                    kArraySizeSmiParameter, kReceiverParameter)
   DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction
                          MachineType::AnyTagged(),  // kAllocationSite
                          MachineType::Int32(),      // kActualArgumentsCount
-                         MachineType::AnyTagged(),  // kFunctionParameter
+                         // JS arguments on the stack
+                         MachineType::AnyTagged(),  // kArraySizeSmiParameter
+                         MachineType::AnyTagged())  // kReceiverParameter
+  DECLARE_DESCRIPTOR(ArraySingleArgumentConstructorDescriptor,
+                     ArrayNArgumentsConstructorDescriptor)
+};
+#else
+class ArraySingleArgumentConstructorDescriptor
+    : public ArrayNArgumentsConstructorDescriptor {
+ public:
+  // This descriptor declares same register arguments as the parent
+  // ArrayNArgumentsConstructorDescriptor and it declares indices for
+  // JS arguments passed on the expression stack.
+  DEFINE_PARAMETERS(kFunction, kAllocationSite, kActualArgumentsCount,
+                    kReceiverParameter, kArraySizeSmiParameter)
+  DEFINE_PARAMETER_TYPES(MachineType::AnyTagged(),  // kFunction
+                         MachineType::AnyTagged(),  // kAllocationSite
+                         MachineType::Int32(),      // kActualArgumentsCount
+                         // JS arguments on the stack
+                         MachineType::AnyTagged(),  // kReceiverParameter
                          MachineType::AnyTagged())  // kArraySizeSmiParameter
   DECLARE_DESCRIPTOR(ArraySingleArgumentConstructorDescriptor,
                      ArrayNArgumentsConstructorDescriptor)
 };
+#endif
 
 class CompareDescriptor : public CallInterfaceDescriptor {
  public:
@@ -1289,6 +1318,52 @@ class WasmMemoryGrowDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(WasmMemoryGrowDescriptor, CallInterfaceDescriptor)
 };
 
+class WasmTableInitDescriptor final : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS_NO_CONTEXT(kDestination, kSource, kSize, kTableIndex,
+                               kSegmentIndex)
+  DEFINE_PARAMETER_TYPES(MachineType::Int32(),      // kDestination
+                         MachineType::Int32(),      // kSource
+                         MachineType::Int32(),      // kSize
+                         MachineType::AnyTagged(),  // kTableIndex
+                         MachineType::AnyTagged(),  // kSegmentindex
+  )
+
+#if V8_TARGET_ARCH_IA32
+  static constexpr bool kPassLastArgOnStack = true;
+#else
+  static constexpr bool kPassLastArgOnStack = false;
+#endif
+
+  // Pass the last parameter through the stack.
+  static constexpr int kStackArgumentsCount = kPassLastArgOnStack ? 1 : 0;
+
+  DECLARE_DESCRIPTOR(WasmTableInitDescriptor, CallInterfaceDescriptor)
+};
+
+class WasmTableCopyDescriptor final : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS_NO_CONTEXT(kDestination, kSource, kSize, kDestinationTable,
+                               kSourceTable)
+  DEFINE_PARAMETER_TYPES(MachineType::Int32(),      // kDestination
+                         MachineType::Int32(),      // kSource
+                         MachineType::Int32(),      // kSize
+                         MachineType::AnyTagged(),  // kDestinationTable
+                         MachineType::AnyTagged(),  // kSourceTable
+  )
+
+#if V8_TARGET_ARCH_IA32
+  static constexpr bool kPassLastArgOnStack = true;
+#else
+  static constexpr bool kPassLastArgOnStack = false;
+#endif
+
+  // Pass the last parameter through the stack.
+  static constexpr int kStackArgumentsCount = kPassLastArgOnStack ? 1 : 0;
+
+  DECLARE_DESCRIPTOR(WasmTableCopyDescriptor, CallInterfaceDescriptor)
+};
+
 class WasmTableGetDescriptor final : public CallInterfaceDescriptor {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kTableIndex, kEntryIndex)
@@ -1361,27 +1436,62 @@ class WasmAtomicNotifyDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(WasmAtomicNotifyDescriptor, CallInterfaceDescriptor)
 };
 
-class WasmI32AtomicWaitDescriptor final : public CallInterfaceDescriptor {
+class WasmI32AtomicWait32Descriptor final : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValue, kTimeoutLow,
+                               kTimeoutHigh)
+  DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Uint32(),  // result 1
+                                    MachineType::Uint32(),  // kAddress
+                                    MachineType::Int32(),   // kExpectedValue
+                                    MachineType::Uint32(),  // kTimeoutLow
+                                    MachineType::Uint32())  // kTimeoutHigh
+  DECLARE_DESCRIPTOR(WasmI32AtomicWait32Descriptor, CallInterfaceDescriptor)
+};
+
+class WasmI64AtomicWait32Descriptor final : public CallInterfaceDescriptor {
+ public:
+  DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValueLow, kExpectedValueHigh,
+                               kTimeoutLow, kTimeoutHigh)
+
+  DEFINE_RESULT_AND_PARAMETER_TYPES_WITH_FLAG(
+      CallInterfaceDescriptorData::kNoStackScan,  // allow untagged stack params
+      MachineType::Uint32(),                      // result 1
+      MachineType::Uint32(),                      // kAddress
+      MachineType::Uint32(),                      // kExpectedValueLow
+      MachineType::Uint32(),                      // kExpectedValueHigh
+      MachineType::Uint32(),                      // kTimeoutLow
+      MachineType::Uint32())                      // kTimeoutHigh
+
+#if V8_TARGET_ARCH_IA32
+  static constexpr bool kPassLastArgOnStack = true;
+#else
+  static constexpr bool kPassLastArgOnStack = false;
+#endif
+
+  // Pass the last parameter through the stack.
+  static constexpr int kStackArgumentsCount = kPassLastArgOnStack ? 1 : 0;
+
+  DECLARE_DESCRIPTOR(WasmI64AtomicWait32Descriptor, CallInterfaceDescriptor)
+};
+
+class WasmI32AtomicWait64Descriptor final : public CallInterfaceDescriptor {
  public:
   DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValue, kTimeout)
-  DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Uint32(),   // result 1
-                                    MachineType::Uint32(),   // kAddress
-                                    MachineType::Int32(),    // kExpectedValue
-                                    MachineType::Float64())  // kTimeout
-  DECLARE_DESCRIPTOR(WasmI32AtomicWaitDescriptor, CallInterfaceDescriptor)
+  DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Uint32(),  // result 1
+                                    MachineType::Uint32(),  // kAddress
+                                    MachineType::Int32(),   // kExpectedValue
+                                    MachineType::Uint64())  // kTimeout
+  DECLARE_DESCRIPTOR(WasmI32AtomicWait64Descriptor, CallInterfaceDescriptor)
 };
 
-class WasmI64AtomicWaitDescriptor final : public CallInterfaceDescriptor {
+class WasmI64AtomicWait64Descriptor final : public CallInterfaceDescriptor {
  public:
-  DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValueHigh, kExpectedValueLow,
-                               kTimeout)
-  DEFINE_RESULT_AND_PARAMETER_TYPES(
-      MachineType::Uint32(),   // result 1
-      MachineType::Uint32(),   // kAddress
-      MachineType::Uint32(),   // kExpectedValueHigh
-      MachineType::Uint32(),   // kExpectedValueLow
-      MachineType::Float64())  // kTimeout
-  DECLARE_DESCRIPTOR(WasmI64AtomicWaitDescriptor, CallInterfaceDescriptor)
+  DEFINE_PARAMETERS_NO_CONTEXT(kAddress, kExpectedValue, kTimeout)
+  DEFINE_RESULT_AND_PARAMETER_TYPES(MachineType::Uint32(),  // result 1
+                                    MachineType::Uint32(),  // kAddress
+                                    MachineType::Uint64(),  // kExpectedValue
+                                    MachineType::Uint64())  // kTimeout
+  DECLARE_DESCRIPTOR(WasmI64AtomicWait64Descriptor, CallInterfaceDescriptor)
 };
 
 class CloneObjectWithVectorDescriptor final : public CallInterfaceDescriptor {
diff --git a/deps/v8/src/codegen/machine-type.h b/deps/v8/src/codegen/machine-type.h
index b89da584c1..ea05441594 100644
--- a/deps/v8/src/codegen/machine-type.h
+++ b/deps/v8/src/codegen/machine-type.h
@@ -268,10 +268,14 @@ class MachineType {
     }
   }
 
-  bool LessThanOrEqualPointerSize() {
+  constexpr bool LessThanOrEqualPointerSize() const {
     return ElementSizeLog2Of(this->representation()) <= kSystemPointerSizeLog2;
   }
 
+  constexpr byte MemSize() const {
+    return 1 << i::ElementSizeLog2Of(this->representation());
+  }
+
  private:
   MachineRepresentation representation_;
   MachineSemantic semantic_;
diff --git a/deps/v8/src/codegen/macro-assembler.h b/deps/v8/src/codegen/macro-assembler.h
index 28b3b3a3c4..01175e585e 100644
--- a/deps/v8/src/codegen/macro-assembler.h
+++ b/deps/v8/src/codegen/macro-assembler.h
@@ -40,7 +40,7 @@ enum AllocationFlags {
 #elif V8_TARGET_ARCH_ARM
 #include "src/codegen/arm/constants-arm.h"
 #include "src/codegen/arm/macro-assembler-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/codegen/ppc/constants-ppc.h"
 #include "src/codegen/ppc/macro-assembler-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
diff --git a/deps/v8/src/codegen/mips/constants-mips.h b/deps/v8/src/codegen/mips/constants-mips.h
index d2b3f6b08f..67d12155a3 100644
--- a/deps/v8/src/codegen/mips/constants-mips.h
+++ b/deps/v8/src/codegen/mips/constants-mips.h
@@ -89,15 +89,18 @@ const uint32_t kHoleNanLower32Offset = 4;
 #error Unknown endianness
 #endif
 
-#define IsFp64Mode() (kFpuMode == kFP64)
-#define IsFp32Mode() (kFpuMode == kFP32)
-#define IsFpxxMode() (kFpuMode == kFPXX)
+constexpr bool IsFp64Mode() { return kFpuMode == kFP64; }
+constexpr bool IsFp32Mode() { return kFpuMode == kFP32; }
+constexpr bool IsFpxxMode() { return kFpuMode == kFPXX; }
 
 #ifndef _MIPS_ARCH_MIPS32RX
-#define IsMipsArchVariant(check) (kArchVariant == check)
+constexpr bool IsMipsArchVariant(const ArchVariants check) {
+  return kArchVariant == check;
+}
 #else
-#define IsMipsArchVariant(check) \
-  (CpuFeatures::IsSupported(static_cast<CpuFeature>(check)))
+bool IsMipsArchVariant(const ArchVariants check) {
+  return CpuFeatures::IsSupported(static_cast<CpuFeature>(check));
+}
 #endif
 
 #if defined(V8_TARGET_LITTLE_ENDIAN)
diff --git a/deps/v8/src/codegen/mips/interface-descriptors-mips.cc b/deps/v8/src/codegen/mips/interface-descriptors-mips.cc
index 0a36e26577..8b8bc1b56d 100644
--- a/deps/v8/src/codegen/mips/interface-descriptors-mips.cc
+++ b/deps/v8/src/codegen/mips/interface-descriptors-mips.cc
@@ -31,19 +31,34 @@ bool CallInterfaceDescriptor::IsValidFloatParameterRegister(Register reg) {
   return reg.code() % 2 == 0;
 }
 
-void WasmI32AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  /* Register t4 correspond to f12 FPU register. */
-  const Register default_stub_registers[] = {a0, a1, t4};
+  const Register default_stub_registers[] = {a0, a1, a2, a3};
   CHECK_EQ(static_cast<size_t>(kParameterCount),
            arraysize(default_stub_registers));
   data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
 }
 
-void WasmI64AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait64Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  /* Register t4 correspond to f12 FPU register. */
-  const Register default_stub_registers[] = {a0, a1, a2, t4};
+  const Register default_stub_registers[] = {a0, a1, a2};
+  CHECK_EQ(static_cast<size_t>(kParameterCount),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
+}
+
+void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  const Register default_stub_registers[] = {a0, a1, a2, a3, t0};
+  CHECK_EQ(static_cast<size_t>(kParameterCount - kStackArgumentsCount),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
+                                   default_stub_registers);
+}
+
+void WasmI64AtomicWait64Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  const Register default_stub_registers[] = {a0, a1, a2};
   CHECK_EQ(static_cast<size_t>(kParameterCount),
            arraysize(default_stub_registers));
   data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
diff --git a/deps/v8/src/codegen/mips/macro-assembler-mips.cc b/deps/v8/src/codegen/mips/macro-assembler-mips.cc
index 6526f48da5..6ae70798c1 100644
--- a/deps/v8/src/codegen/mips/macro-assembler-mips.cc
+++ b/deps/v8/src/codegen/mips/macro-assembler-mips.cc
@@ -4668,6 +4668,7 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 // Debugging.
 
 void TurboAssembler::Trap() { stop(); }
+void TurboAssembler::DebugBreak() { stop(); }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason, Register rs,
                             Operand rt) {
@@ -5374,31 +5375,38 @@ void TurboAssembler::CallCFunctionHelper(Register function_base,
 
     // Save the frame pointer and PC so that the stack layout remains iterable,
     // even without an ExitFrame which normally exists between JS and C frames.
-    if (isolate() != nullptr) {
-      // 't' registers are caller-saved so this is safe as a scratch register.
-      Register scratch1 = t4;
-      Register scratch2 = t5;
-      DCHECK(!AreAliased(scratch1, scratch2, function_base));
-
-      Label get_pc;
-      mov(scratch1, ra);
-      Call(&get_pc);
-
-      bind(&get_pc);
-      mov(scratch2, ra);
-      mov(ra, scratch1);
-
-      li(scratch1, ExternalReference::fast_c_call_caller_pc_address(isolate()));
-      sw(scratch2, MemOperand(scratch1));
-      li(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-      sw(fp, MemOperand(scratch1));
+    // 't' registers are caller-saved so this is safe as a scratch register.
+    Register pc_scratch = t4;
+    Register scratch = t5;
+    DCHECK(!AreAliased(pc_scratch, scratch, function_base));
+
+    mov(scratch, ra);
+    nal();
+    mov(pc_scratch, ra);
+    mov(ra, scratch);
+
+    // See x64 code for reasoning about how to address the isolate data fields.
+    if (root_array_available()) {
+      sw(pc_scratch, MemOperand(kRootRegister,
+                                IsolateData::fast_c_call_caller_pc_offset()));
+      sw(fp, MemOperand(kRootRegister,
+                        IsolateData::fast_c_call_caller_fp_offset()));
+    } else {
+      DCHECK_NOT_NULL(isolate());
+      li(scratch, ExternalReference::fast_c_call_caller_pc_address(isolate()));
+      sw(pc_scratch, MemOperand(scratch));
+      li(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
+      sw(fp, MemOperand(scratch));
     }
 
     Call(function_base, function_offset);
 
-    if (isolate() != nullptr) {
-      // We don't unset the PC; the FP is the source of truth.
-      Register scratch = t4;
+    // We don't unset the PC; the FP is the source of truth.
+    if (root_array_available()) {
+      sw(zero_reg, MemOperand(kRootRegister,
+                              IsolateData::fast_c_call_caller_fp_offset()));
+    } else {
+      DCHECK_NOT_NULL(isolate());
       li(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
       sw(zero_reg, MemOperand(scratch));
     }
@@ -5469,7 +5477,9 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
   li(kSpeculationPoisonRegister, -1);
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
 
   // Save the deipt id in kRootRegister (we don't need the roots array from now
diff --git a/deps/v8/src/codegen/mips/macro-assembler-mips.h b/deps/v8/src/codegen/mips/macro-assembler-mips.h
index f916b9d101..d7441c2fcf 100644
--- a/deps/v8/src/codegen/mips/macro-assembler-mips.h
+++ b/deps/v8/src/codegen/mips/macro-assembler-mips.h
@@ -103,6 +103,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // Debugging.
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Calls Abort(msg) if the condition cc is not satisfied.
   // Use --debug_code to enable.
@@ -236,7 +237,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // The return address on the stack is used by frame iteration.
   void StoreReturnAddressAndCall(Register target);
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   void Ret(COND_ARGS);
   inline void Ret(BranchDelaySlot bd, Condition cond = al,
@@ -813,6 +815,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void ResetSpeculationPoisonRegister();
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
  protected:
   void BranchLong(Label* L, BranchDelaySlot bdslot);
 
diff --git a/deps/v8/src/codegen/mips64/interface-descriptors-mips64.cc b/deps/v8/src/codegen/mips64/interface-descriptors-mips64.cc
index e32d6c6d6e..84910f1ee9 100644
--- a/deps/v8/src/codegen/mips64/interface-descriptors-mips64.cc
+++ b/deps/v8/src/codegen/mips64/interface-descriptors-mips64.cc
@@ -31,19 +31,34 @@ bool CallInterfaceDescriptor::IsValidFloatParameterRegister(Register reg) {
   return reg.code() % 2 == 0;
 }
 
-void WasmI32AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait32Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  /* Register t0 correspond to f12 FPU register. */
-  const Register default_stub_registers[] = {a0, a1, t0};
+  const Register default_stub_registers[] = {a0, a1, a2, a3};
   CHECK_EQ(static_cast<size_t>(kParameterCount),
            arraysize(default_stub_registers));
   data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
 }
 
-void WasmI64AtomicWaitDescriptor::InitializePlatformSpecific(
+void WasmI32AtomicWait64Descriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
-  /* Register t0 correspond to f12 FPU register. */
-  const Register default_stub_registers[] = {a0, a1, a2, t0};
+  const Register default_stub_registers[] = {a0, a1, a2};
+  CHECK_EQ(static_cast<size_t>(kParameterCount),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
+}
+
+void WasmI64AtomicWait32Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  const Register default_stub_registers[] = {a0, a1, a2, a3, a4};
+  CHECK_EQ(static_cast<size_t>(kParameterCount - kStackArgumentsCount),
+           arraysize(default_stub_registers));
+  data->InitializePlatformSpecific(kParameterCount - kStackArgumentsCount,
+                                   default_stub_registers);
+}
+
+void WasmI64AtomicWait64Descriptor::InitializePlatformSpecific(
+    CallInterfaceDescriptorData* data) {
+  const Register default_stub_registers[] = {a0, a1, a2};
   CHECK_EQ(static_cast<size_t>(kParameterCount),
            arraysize(default_stub_registers));
   data->InitializePlatformSpecific(kParameterCount, default_stub_registers);
diff --git a/deps/v8/src/codegen/mips64/macro-assembler-mips64.cc b/deps/v8/src/codegen/mips64/macro-assembler-mips64.cc
index a9bbcf54aa..78f3228f24 100644
--- a/deps/v8/src/codegen/mips64/macro-assembler-mips64.cc
+++ b/deps/v8/src/codegen/mips64/macro-assembler-mips64.cc
@@ -4984,6 +4984,7 @@ void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
 // Debugging.
 
 void TurboAssembler::Trap() { stop(); }
+void TurboAssembler::DebugBreak() { stop(); }
 
 void TurboAssembler::Assert(Condition cc, AbortReason reason, Register rs,
                             Operand rt) {
@@ -5698,31 +5699,38 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
     // Save the frame pointer and PC so that the stack layout remains iterable,
     // even without an ExitFrame which normally exists between JS and C frames.
-    if (isolate() != nullptr) {
-      // 't' registers are caller-saved so this is safe as a scratch register.
-      Register scratch1 = t1;
-      Register scratch2 = t2;
-      DCHECK(!AreAliased(scratch1, scratch2, function));
-
-      Label get_pc;
-      mov(scratch1, ra);
-      Call(&get_pc);
-
-      bind(&get_pc);
-      mov(scratch2, ra);
-      mov(ra, scratch1);
-
-      li(scratch1, ExternalReference::fast_c_call_caller_pc_address(isolate()));
-      Sd(scratch2, MemOperand(scratch1));
-      li(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-      Sd(fp, MemOperand(scratch1));
+    // 't' registers are caller-saved so this is safe as a scratch register.
+    Register pc_scratch = t1;
+    Register scratch = t2;
+    DCHECK(!AreAliased(pc_scratch, scratch, function));
+
+    mov(scratch, ra);
+    nal();
+    mov(pc_scratch, ra);
+    mov(ra, scratch);
+
+    // See x64 code for reasoning about how to address the isolate data fields.
+    if (root_array_available()) {
+      Sd(pc_scratch, MemOperand(kRootRegister,
+                                IsolateData::fast_c_call_caller_pc_offset()));
+      Sd(fp, MemOperand(kRootRegister,
+                        IsolateData::fast_c_call_caller_fp_offset()));
+    } else {
+      DCHECK_NOT_NULL(isolate());
+      li(scratch, ExternalReference::fast_c_call_caller_pc_address(isolate()));
+      Sd(pc_scratch, MemOperand(scratch));
+      li(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
+      Sd(fp, MemOperand(scratch));
     }
 
     Call(function);
 
-    if (isolate() != nullptr) {
-      // We don't unset the PC; the FP is the source of truth.
-      Register scratch = t1;
+    // We don't unset the PC; the FP is the source of truth.
+    if (root_array_available()) {
+      Sd(zero_reg, MemOperand(kRootRegister,
+                              IsolateData::fast_c_call_caller_fp_offset()));
+    } else {
+      DCHECK_NOT_NULL(isolate());
       li(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
       Sd(zero_reg, MemOperand(scratch));
     }
@@ -5793,7 +5801,9 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
   li(kSpeculationPoisonRegister, -1);
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
 
   // Save the deopt id in kRootRegister (we don't need the roots array from now
diff --git a/deps/v8/src/codegen/mips64/macro-assembler-mips64.h b/deps/v8/src/codegen/mips64/macro-assembler-mips64.h
index d1f681c38a..c8b8d2876f 100644
--- a/deps/v8/src/codegen/mips64/macro-assembler-mips64.h
+++ b/deps/v8/src/codegen/mips64/macro-assembler-mips64.h
@@ -123,6 +123,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // Debugging.
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Calls Abort(msg) if the condition cc is not satisfied.
   // Use --debug_code to enable.
@@ -259,7 +260,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   // The return address on the stack is used by frame iteration.
   void StoreReturnAddressAndCall(Register target);
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   void Ret(COND_ARGS);
   inline void Ret(BranchDelaySlot bd, Condition cond = al,
@@ -819,6 +821,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void ResetSpeculationPoisonRegister();
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
  protected:
   inline Register GetRtAsRegisterHelper(const Operand& rt, Register scratch);
   inline int32_t GetOffset(int32_t offset, Label* L, OffsetSize bits);
diff --git a/deps/v8/src/codegen/ppc/assembler-ppc.cc b/deps/v8/src/codegen/ppc/assembler-ppc.cc
index 321386af14..a305a104f0 100644
--- a/deps/v8/src/codegen/ppc/assembler-ppc.cc
+++ b/deps/v8/src/codegen/ppc/assembler-ppc.cc
@@ -36,7 +36,7 @@
 
 #include "src/codegen/ppc/assembler-ppc.h"
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/base/bits.h"
 #include "src/base/cpu.h"
@@ -1960,4 +1960,4 @@ Register UseScratchRegisterScope::Acquire() {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/codegen/ppc/assembler-ppc.h b/deps/v8/src/codegen/ppc/assembler-ppc.h
index 222d4c28ad..b27a4fd8fe 100644
--- a/deps/v8/src/codegen/ppc/assembler-ppc.h
+++ b/deps/v8/src/codegen/ppc/assembler-ppc.h
@@ -230,10 +230,6 @@ class Assembler : public AssemblerBase {
     return link(L) - pc_offset();
   }
 
-  // Puts a labels target address at the given position.
-  // The high 8 bits are set to zero.
-  void label_at_put(Label* L, int at_offset);
-
   V8_INLINE static bool IsConstantPoolLoadStart(
       Address pc, ConstantPoolEntry::Access* access = nullptr);
   V8_INLINE static bool IsConstantPoolLoadEnd(
diff --git a/deps/v8/src/codegen/ppc/constants-ppc.cc b/deps/v8/src/codegen/ppc/constants-ppc.cc
index 4cee2cbcb5..ee2e19aa24 100644
--- a/deps/v8/src/codegen/ppc/constants-ppc.cc
+++ b/deps/v8/src/codegen/ppc/constants-ppc.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/codegen/ppc/constants-ppc.h"
 
@@ -46,4 +46,4 @@ int Registers::Number(const char* name) {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/codegen/ppc/constants-ppc.h b/deps/v8/src/codegen/ppc/constants-ppc.h
index d8892097bd..fe7df45ae5 100644
--- a/deps/v8/src/codegen/ppc/constants-ppc.h
+++ b/deps/v8/src/codegen/ppc/constants-ppc.h
@@ -20,7 +20,7 @@
 #define UNIMPLEMENTED_PPC()
 #endif
 
-#if V8_HOST_ARCH_PPC &&                                            \
+#if (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) &&                    \
     (V8_OS_AIX || (V8_TARGET_ARCH_PPC64 && V8_TARGET_BIG_ENDIAN && \
                    (!defined(_CALL_ELF) || _CALL_ELF == 1)))
 #define ABI_USES_FUNCTION_DESCRIPTORS 1
@@ -28,28 +28,30 @@
 #define ABI_USES_FUNCTION_DESCRIPTORS 0
 #endif
 
-#if !V8_HOST_ARCH_PPC || V8_OS_AIX || V8_TARGET_ARCH_PPC64
+#if !(V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) || V8_OS_AIX || \
+    V8_TARGET_ARCH_PPC64
 #define ABI_PASSES_HANDLES_IN_REGS 1
 #else
 #define ABI_PASSES_HANDLES_IN_REGS 0
 #endif
 
-#if !V8_HOST_ARCH_PPC || !V8_TARGET_ARCH_PPC64 || V8_TARGET_LITTLE_ENDIAN || \
-    (defined(_CALL_ELF) && _CALL_ELF == 2)
+#if !(V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) || !V8_TARGET_ARCH_PPC64 || \
+    V8_TARGET_LITTLE_ENDIAN || (defined(_CALL_ELF) && _CALL_ELF == 2)
 #define ABI_RETURNS_OBJECT_PAIRS_IN_REGS 1
 #else
 #define ABI_RETURNS_OBJECT_PAIRS_IN_REGS 0
 #endif
 
-#if !V8_HOST_ARCH_PPC ||     \
-    (V8_TARGET_ARCH_PPC64 && \
+#if !(V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) || \
+    (V8_TARGET_ARCH_PPC64 &&                     \
      (V8_TARGET_LITTLE_ENDIAN || (defined(_CALL_ELF) && _CALL_ELF == 2)))
 #define ABI_CALL_VIA_IP 1
 #else
 #define ABI_CALL_VIA_IP 0
 #endif
 
-#if !V8_HOST_ARCH_PPC || V8_OS_AIX || V8_TARGET_ARCH_PPC64
+#if !(V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) || V8_OS_AIX || \
+    V8_TARGET_ARCH_PPC64
 #define ABI_TOC_REGISTER 2
 #else
 #define ABI_TOC_REGISTER 13
diff --git a/deps/v8/src/codegen/ppc/cpu-ppc.cc b/deps/v8/src/codegen/ppc/cpu-ppc.cc
index 243fa29a46..9559af7778 100644
--- a/deps/v8/src/codegen/ppc/cpu-ppc.cc
+++ b/deps/v8/src/codegen/ppc/cpu-ppc.cc
@@ -4,7 +4,7 @@
 
 // CPU specific code for ppc independent of OS goes here.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/codegen/cpu-features.h"
 
@@ -47,4 +47,4 @@ void CpuFeatures::FlushICache(void* buffer, size_t size) {
 }  // namespace v8
 
 #undef INSTR_AND_DATA_CACHE_COHERENCY
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/codegen/ppc/interface-descriptors-ppc.cc b/deps/v8/src/codegen/ppc/interface-descriptors-ppc.cc
index 3d378d7a43..f2264b05fa 100644
--- a/deps/v8/src/codegen/ppc/interface-descriptors-ppc.cc
+++ b/deps/v8/src/codegen/ppc/interface-descriptors-ppc.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/codegen/interface-descriptors.h"
 
@@ -286,4 +286,4 @@ void RunMicrotasksEntryDescriptor::InitializePlatformSpecific(
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/codegen/ppc/macro-assembler-ppc.cc b/deps/v8/src/codegen/ppc/macro-assembler-ppc.cc
index 96a9058240..ca6d472c93 100644
--- a/deps/v8/src/codegen/ppc/macro-assembler-ppc.cc
+++ b/deps/v8/src/codegen/ppc/macro-assembler-ppc.cc
@@ -5,7 +5,7 @@
 #include <assert.h>  // For assert
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ -673,23 +673,6 @@ void TurboAssembler::RestoreFrameStateForTailCall() {
   mtlr(r0);
 }
 
-int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
-  // The registers are pushed starting with the highest encoding,
-  // which means that lowest encodings are closest to the stack pointer.
-  RegList regs = kSafepointSavedRegisters;
-  int index = 0;
-
-  DCHECK(reg_code >= 0 && reg_code < kNumRegisters);
-
-  for (int16_t i = 0; i < reg_code; i++) {
-    if ((regs & (1 << i)) != 0) {
-      index++;
-    }
-  }
-
-  return index;
-}
-
 void TurboAssembler::CanonicalizeNaN(const DoubleRegister dst,
                                      const DoubleRegister src) {
   // Turn potential sNaN into qNaN.
@@ -1914,20 +1897,32 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    Register scratch1 = r7;
-    Register scratch2 = r8;
-    Push(scratch1, scratch2);
+  Register addr_scratch = r7;
+  Register scratch = r8;
+  Push(scratch);
+  mflr(scratch);
+  // See x64 code for reasoning about how to address the isolate data fields.
+  if (root_array_available()) {
+    LoadPC(r0);
+    StoreP(r0, MemOperand(kRootRegister,
+                          IsolateData::fast_c_call_caller_pc_offset()));
+    StoreP(fp, MemOperand(kRootRegister,
+                          IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Push(addr_scratch);
 
-    mflr(scratch2);
-    Move(scratch1, ExternalReference::fast_c_call_caller_pc_address(isolate()));
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_pc_address(isolate()));
     LoadPC(r0);
-    StoreP(r0, MemOperand(scratch1));
-    Move(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    StoreP(fp, MemOperand(scratch1));
-    mtlr(scratch2);
-    Pop(scratch1, scratch2);
+    StoreP(r0, MemOperand(addr_scratch));
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    StoreP(fp, MemOperand(addr_scratch));
+    Pop(addr_scratch);
   }
+  mtlr(scratch);
+  Pop(scratch);
 
   // Just call directly. The function called cannot cause a GC, or
   // allow preemption, so the return address in the link register
@@ -1947,15 +1942,21 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
   Call(dest);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
-    Register scratch1 = r7;
-    Register scratch2 = r8;
-    Push(scratch1, scratch2);
-    Move(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    mov(scratch2, Operand::Zero());
-    StoreP(scratch2, MemOperand(scratch1));
-    Pop(scratch1, scratch2);
+  // We don't unset the PC; the FP is the source of truth.
+  Register zero_scratch = r0;
+  mov(zero_scratch, Operand::Zero());
+
+  if (root_array_available()) {
+    StoreP(
+        zero_scratch,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Push(addr_scratch);
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    StoreP(zero_scratch, MemOperand(addr_scratch));
+    Pop(addr_scratch);
   }
 
   // Remove frame bought in PrepareCallCFunction
@@ -3013,7 +3014,9 @@ void TurboAssembler::StoreReturnAddressAndCall(Register target) {
             SizeOfCodeGeneratedSince(&start_call));
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
 
   // Save the deopt id in r29 (we don't need the roots array from now on).
@@ -3036,8 +3039,9 @@ void TurboAssembler::ZeroExtWord32(Register dst, Register src) {
 }
 
 void TurboAssembler::Trap() { stop(); }
+void TurboAssembler::DebugBreak() { stop(); }
 
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/codegen/ppc/macro-assembler-ppc.h b/deps/v8/src/codegen/ppc/macro-assembler-ppc.h
index 87de0a77c8..2c46124b24 100644
--- a/deps/v8/src/codegen/ppc/macro-assembler-ppc.h
+++ b/deps/v8/src/codegen/ppc/macro-assembler-ppc.h
@@ -365,6 +365,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void MovFromFloatResult(DoubleRegister dst);
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Calls Abort(msg) if the condition cond is not satisfied.
   // Use --debug_code to enable.
@@ -419,7 +420,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void JumpCodeObject(Register code_object) override;
 
   void CallBuiltinByIndex(Register builtin_index) override;
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   // Emit code to discard a non-negative number of pointer-sized elements
   // from the stack, clobbering only the sp register.
@@ -638,6 +640,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void ResetSpeculationPoisonRegister();
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
  private:
   static const int kSmiShift = kSmiTagSize + kSmiShiftSize;
 
@@ -763,7 +775,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
   void InvokeFunction(Register function, Register expected_parameter_count,
                       Register actual_parameter_count, InvokeFlag flag);
 
-  void DebugBreak();
   // Frame restart support
   void MaybeDropFrames();
 
@@ -952,13 +963,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
                       Register actual_parameter_count, Label* done,
                       InvokeFlag flag);
 
-  // Compute memory operands for safepoint stack slots.
-  static int SafepointRegisterStackIndex(int reg_code);
-
-  // Needs access to SafepointRegisterStackIndex for compiled frame
-  // traversal.
-  friend class StandardFrame;
-
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
 
diff --git a/deps/v8/src/codegen/ppc/register-ppc.h b/deps/v8/src/codegen/ppc/register-ppc.h
index 92f7632e14..8c89aecec7 100644
--- a/deps/v8/src/codegen/ppc/register-ppc.h
+++ b/deps/v8/src/codegen/ppc/register-ppc.h
@@ -59,7 +59,6 @@ namespace internal {
 
 // Register list in load/store instructions
 // Note that the bit values must match those used in actual instruction encoding
-const int kNumRegs = 32;
 
 // Caller-saved/arguments registers
 const RegList kJSCallerSaved = 1 << 3 |   // r3  a1
@@ -138,10 +137,6 @@ const RegList kCalleeSavedDoubles = 1 << 14 |  // d14
 
 const int kNumCalleeSavedDoubles = 18;
 
-// Number of registers for which space is reserved in safepoints. Must be a
-// multiple of 8.
-const int kNumSafepointRegisters = 32;
-
 // The following constants describe the stack frame linkage area as
 // defined by the ABI.  Note that kNumRequiredStackFrameSlots must
 // satisfy alignment requirements (rounding up if required).
@@ -177,12 +172,6 @@ const int kStackFrameLRSlot = 2;
 const int kStackFrameExtraParamSlot = 14;
 #endif
 
-// Define the list of registers actually saved at safepoints.
-// Note that the number of saved registers may be smaller than the reserved
-// space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
-const RegList kSafepointSavedRegisters = kJSCallerSaved | kCalleeSaved;
-const int kNumSafepointSavedRegisters = kNumJSCallerSaved + kNumCalleeSaved;
-
 enum RegisterCode {
 #define REGISTER_CODE(R) kRegCode_##R,
   GENERAL_REGISTERS(REGISTER_CODE)
diff --git a/deps/v8/src/codegen/register-arch.h b/deps/v8/src/codegen/register-arch.h
index aa668a9158..21a7233016 100644
--- a/deps/v8/src/codegen/register-arch.h
+++ b/deps/v8/src/codegen/register-arch.h
@@ -16,7 +16,7 @@
 #include "src/codegen/arm64/register-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/codegen/arm/register-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/codegen/ppc/register-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/codegen/mips/register-mips.h"
diff --git a/deps/v8/src/codegen/register-configuration.cc b/deps/v8/src/codegen/register-configuration.cc
index c8f768e6de..5752b46339 100644
--- a/deps/v8/src/codegen/register-configuration.cc
+++ b/deps/v8/src/codegen/register-configuration.cc
@@ -60,6 +60,8 @@ static int get_num_allocatable_double_registers() {
       kMaxAllocatableDoubleRegisterCount;
 #elif V8_TARGET_ARCH_PPC
       kMaxAllocatableDoubleRegisterCount;
+#elif V8_TARGET_ARCH_PPC64
+      kMaxAllocatableDoubleRegisterCount;
 #elif V8_TARGET_ARCH_S390
       kMaxAllocatableDoubleRegisterCount;
 #else
diff --git a/deps/v8/src/codegen/reloc-info.cc b/deps/v8/src/codegen/reloc-info.cc
index 039a6746b1..9f07978932 100644
--- a/deps/v8/src/codegen/reloc-info.cc
+++ b/deps/v8/src/codegen/reloc-info.cc
@@ -329,7 +329,7 @@ bool RelocInfo::OffHeapTargetIsCodedSpecially() {
   return false;
 #elif defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_MIPS) || \
     defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_PPC) ||  \
-    defined(V8_TARGET_ARCH_S390)
+    defined(V8_TARGET_ARCH_PPC64) || defined(V8_TARGET_ARCH_S390)
   return true;
 #endif
 }
diff --git a/deps/v8/src/codegen/s390/assembler-s390-inl.h b/deps/v8/src/codegen/s390/assembler-s390-inl.h
index f911bdabf6..e34cfa0cbd 100644
--- a/deps/v8/src/codegen/s390/assembler-s390-inl.h
+++ b/deps/v8/src/codegen/s390/assembler-s390-inl.h
@@ -48,7 +48,9 @@ namespace internal {
 
 bool CpuFeatures::SupportsOptimizer() { return true; }
 
-bool CpuFeatures::SupportsWasmSimd128() { return false; }
+bool CpuFeatures::SupportsWasmSimd128() {
+  return CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1);
+}
 
 void RelocInfo::apply(intptr_t delta) {
   // Absolute code pointer inside code object moves with the code object.
@@ -114,7 +116,25 @@ Address RelocInfo::target_address_address() {
 
 Address RelocInfo::constant_pool_entry_address() { UNREACHABLE(); }
 
-int RelocInfo::target_address_size() { return Assembler::kSpecialTargetSize; }
+void Assembler::set_target_compressed_address_at(
+    Address pc, Address constant_pool, Tagged_t target,
+    ICacheFlushMode icache_flush_mode) {
+  Assembler::set_target_address_at(
+      pc, constant_pool, static_cast<Address>(target), icache_flush_mode);
+}
+
+int RelocInfo::target_address_size() {
+  if (IsCodedSpecially()) {
+    return Assembler::kSpecialTargetSize;
+  } else {
+    return kSystemPointerSize;
+  }
+}
+
+Tagged_t Assembler::target_compressed_address_at(Address pc,
+                                                 Address constant_pool) {
+  return static_cast<Tagged_t>(target_address_at(pc, constant_pool));
+}
 
 Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
   SixByteInstr instr =
@@ -124,32 +144,58 @@ Handle<Object> Assembler::code_target_object_handle_at(Address pc) {
 }
 
 HeapObject RelocInfo::target_object() {
-  DCHECK(IsCodeTarget(rmode_) || rmode_ == FULL_EMBEDDED_OBJECT);
-  return HeapObject::cast(
-      Object(Assembler::target_address_at(pc_, constant_pool_)));
+  DCHECK(IsCodeTarget(rmode_) || IsEmbeddedObjectMode(rmode_));
+  if (IsCompressedEmbeddedObject(rmode_)) {
+    return HeapObject::cast(Object(DecompressTaggedAny(
+        host_.address(),
+        Assembler::target_compressed_address_at(pc_, constant_pool_))));
+  } else {
+    return HeapObject::cast(
+        Object(Assembler::target_address_at(pc_, constant_pool_)));
+  }
 }
 
 HeapObject RelocInfo::target_object_no_host(Isolate* isolate) {
-  return target_object();
+  if (IsCompressedEmbeddedObject(rmode_)) {
+    return HeapObject::cast(Object(DecompressTaggedAny(
+        isolate,
+        Assembler::target_compressed_address_at(pc_, constant_pool_))));
+  } else {
+    return target_object();
+  }
+}
+
+Handle<HeapObject> Assembler::compressed_embedded_object_handle_at(
+    Address pc, Address const_pool) {
+  return GetEmbeddedObject(target_compressed_address_at(pc, const_pool));
 }
 
 Handle<HeapObject> RelocInfo::target_object_handle(Assembler* origin) {
   DCHECK(IsRelativeCodeTarget(rmode_) || IsCodeTarget(rmode_) ||
-         rmode_ == FULL_EMBEDDED_OBJECT);
-  if (rmode_ == FULL_EMBEDDED_OBJECT) {
+         IsEmbeddedObjectMode(rmode_));
+  if (IsCodeTarget(rmode_) || IsRelativeCodeTarget(rmode_)) {
+    return Handle<HeapObject>::cast(origin->code_target_object_handle_at(pc_));
+  } else {
+    if (IsCompressedEmbeddedObject(rmode_)) {
+      return origin->compressed_embedded_object_handle_at(pc_, constant_pool_);
+    }
     return Handle<HeapObject>(reinterpret_cast<Address*>(
         Assembler::target_address_at(pc_, constant_pool_)));
-  } else {
-    return Handle<HeapObject>::cast(origin->code_target_object_handle_at(pc_));
   }
 }
 
 void RelocInfo::set_target_object(Heap* heap, HeapObject target,
                                   WriteBarrierMode write_barrier_mode,
                                   ICacheFlushMode icache_flush_mode) {
-  DCHECK(IsCodeTarget(rmode_) || rmode_ == FULL_EMBEDDED_OBJECT);
-  Assembler::set_target_address_at(pc_, constant_pool_, target.ptr(),
-                                   icache_flush_mode);
+  DCHECK(IsCodeTarget(rmode_) || IsEmbeddedObjectMode(rmode_));
+  if (IsCompressedEmbeddedObject(rmode_)) {
+    Assembler::set_target_compressed_address_at(
+        pc_, constant_pool_, CompressTagged(target.ptr()), icache_flush_mode);
+  } else {
+    DCHECK(IsFullEmbeddedObject(rmode_));
+    Assembler::set_target_address_at(pc_, constant_pool_, target.ptr(),
+                                     icache_flush_mode);
+  }
   if (write_barrier_mode == UPDATE_WRITE_BARRIER && !host().is_null() &&
       !FLAG_disable_write_barriers) {
     WriteBarrierForCode(host(), this, target);
@@ -187,13 +233,16 @@ void RelocInfo::set_target_runtime_entry(Address target,
 }
 
 void RelocInfo::WipeOut() {
-  DCHECK(IsFullEmbeddedObject(rmode_) || IsCodeTarget(rmode_) ||
+  DCHECK(IsEmbeddedObjectMode(rmode_) || IsCodeTarget(rmode_) ||
          IsRuntimeEntry(rmode_) || IsExternalReference(rmode_) ||
          IsInternalReference(rmode_) || IsInternalReferenceEncoded(rmode_) ||
          IsOffHeapTarget(rmode_));
   if (IsInternalReference(rmode_)) {
     // Jump table entry
     Memory<Address>(pc_) = kNullAddress;
+  } else if (IsCompressedEmbeddedObject(rmode_)) {
+    Assembler::set_target_compressed_address_at(pc_, constant_pool_,
+                                                kNullAddress);
   } else if (IsInternalReferenceEncoded(rmode_) || IsOffHeapTarget(rmode_)) {
     // mov sequence
     // Currently used only by deserializer, no need to flush.
diff --git a/deps/v8/src/codegen/s390/assembler-s390.cc b/deps/v8/src/codegen/s390/assembler-s390.cc
index 88d2265712..d96bfd8b84 100644
--- a/deps/v8/src/codegen/s390/assembler-s390.cc
+++ b/deps/v8/src/codegen/s390/assembler-s390.cc
@@ -580,16 +580,6 @@ void Assembler::next(Label* L) {
   }
 }
 
-bool Assembler::is_near(Label* L, Condition cond) {
-  DCHECK(L->is_bound());
-  if (L->is_bound() == false) return false;
-
-  int maxReach = ((cond == al) ? 26 : 16);
-  int offset = L->pos() - pc_offset();
-
-  return is_intn(offset, maxReach);
-}
-
 int Assembler::link(Label* L) {
   int position;
   if (L->is_bound()) {
diff --git a/deps/v8/src/codegen/s390/assembler-s390.h b/deps/v8/src/codegen/s390/assembler-s390.h
index 933996050c..bf746df27f 100644
--- a/deps/v8/src/codegen/s390/assembler-s390.h
+++ b/deps/v8/src/codegen/s390/assembler-s390.h
@@ -266,27 +266,30 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Otherwise, returns the current pc_offset().
   int link(Label* L);
 
-  // Determines if Label is bound and near enough so that a single
-  // branch instruction can be used to reach it.
-  bool is_near(Label* L, Condition cond);
-
   // Returns the branch offset to the given label from the current code position
   // Links the label to the current position if it is still unbound
   int branch_offset(Label* L) { return link(L) - pc_offset(); }
 
-  // Puts a labels target address at the given position.
-  // The high 8 bits are set to zero.
-  void label_at_put(Label* L, int at_offset);
   void load_label_offset(Register r1, Label* L);
 
   // Read/Modify the code target address in the branch/call instruction at pc.
   // The isolate argument is unused (and may be nullptr) when skipping flushing.
   V8_INLINE static Address target_address_at(Address pc, Address constant_pool);
+
+  // Read/Modify the code target address in the branch/call instruction at pc.
+  inline static Tagged_t target_compressed_address_at(Address pc,
+                                                      Address constant_pool);
   V8_INLINE static void set_target_address_at(
       Address pc, Address constant_pool, Address target,
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
 
+  inline static void set_target_compressed_address_at(
+      Address pc, Address constant_pool, Tagged_t target,
+      ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
+
   inline Handle<Object> code_target_object_handle_at(Address pc);
+  inline Handle<HeapObject> compressed_embedded_object_handle_at(
+      Address pc, Address constant_pool);
   // This sets the branch destination.
   // This is for calls and branches within generated code.
   inline static void deserialization_set_special_target_at(
diff --git a/deps/v8/src/codegen/s390/constants-s390.h b/deps/v8/src/codegen/s390/constants-s390.h
index e2a906204e..6cd5e4d9fa 100644
--- a/deps/v8/src/codegen/s390/constants-s390.h
+++ b/deps/v8/src/codegen/s390/constants-s390.h
@@ -613,7 +613,9 @@ using SixByteInstr = uint64_t;
   V(vperm, VPERM, 0xE78C) /* type = VRR_E VECTOR PERMUTE  */                  \
   V(vsel, VSEL, 0xE78D)   /* type = VRR_E VECTOR SELECT  */                   \
   V(vfms, VFMS, 0xE78E)   /* type = VRR_E VECTOR FP MULTIPLY AND SUBTRACT  */ \
-  V(vfma, VFMA, 0xE78F)   /* type = VRR_E VECTOR FP MULTIPLY AND ADD  */
+  V(vfnms, VFNMS,                                                             \
+    0xE79E) /* type = VRR_E VECTOR FP NEGATIVE MULTIPLY AND SUBTRACT  */      \
+  V(vfma, VFMA, 0xE78F) /* type = VRR_E VECTOR FP MULTIPLY AND ADD  */
 
 #define S390_VRI_C_OPCODE_LIST(V) \
   V(vrep, VREP, 0xE74D) /* type = VRI_C VECTOR REPLICATE  */
@@ -2331,6 +2333,13 @@ class VRR_E_Instruction : SixByteInstruction {
   DECLARE_FIELD_FOR_SIX_BYTE_INSTR(M5Value, uint32_t, 28, 32)
 };
 
+class VRR_F_Instruction : SixByteInstruction {
+ public:
+  DECLARE_FIELD_FOR_SIX_BYTE_INSTR(R1Value, int, 8, 12)
+  DECLARE_FIELD_FOR_SIX_BYTE_INSTR(R2Value, int, 12, 16)
+  DECLARE_FIELD_FOR_SIX_BYTE_INSTR(R3Value, int, 16, 20)
+};
+
 class VRX_Instruction : SixByteInstruction {
  public:
   DECLARE_FIELD_FOR_SIX_BYTE_INSTR(R1Value, int, 8, 12)
diff --git a/deps/v8/src/codegen/s390/macro-assembler-s390.cc b/deps/v8/src/codegen/s390/macro-assembler-s390.cc
index c540a5773b..77bf0ee916 100644
--- a/deps/v8/src/codegen/s390/macro-assembler-s390.cc
+++ b/deps/v8/src/codegen/s390/macro-assembler-s390.cc
@@ -122,7 +122,11 @@ void TurboAssembler::LoadFromConstantsTable(Register destination,
   CHECK(is_uint19(offset));
   DCHECK_NE(destination, r0);
   LoadRoot(destination, RootIndex::kBuiltinsConstantsTable);
-  LoadP(destination, MemOperand(destination, offset), r1);
+  LoadTaggedPointerField(
+      destination,
+      FieldMemOperand(destination,
+                      FixedArray::OffsetOfElementAt(constant_index)),
+      r1);
 }
 
 void TurboAssembler::LoadRootRelative(Register destination, int32_t offset) {
@@ -287,15 +291,22 @@ void TurboAssembler::Push(Smi smi) {
   push(r0);
 }
 
-void TurboAssembler::Move(Register dst, Handle<HeapObject> value) {
+void TurboAssembler::Move(Register dst, Handle<HeapObject> value,
+                          RelocInfo::Mode rmode) {
   // TODO(jgruber,v8:8887): Also consider a root-relative load when generating
   // non-isolate-independent code. In many cases it might be cheaper than
   // embedding the relocatable value.
   if (root_array_available_ && options().isolate_independent_code) {
     IndirectLoadConstant(dst, value);
     return;
+  } else if (RelocInfo::IsCompressedEmbeddedObject(rmode)) {
+    EmbeddedObjectIndex index = AddEmbeddedObject(value);
+    DCHECK(is_uint32(index));
+    mov(dst, Operand(static_cast<int>(index), rmode));
+  } else {
+    DCHECK(RelocInfo::IsFullEmbeddedObject(rmode));
+    mov(dst, Operand(value.address(), rmode));
   }
-  mov(dst, Operand(value));
 }
 
 void TurboAssembler::Move(Register dst, ExternalReference reference) {
@@ -426,6 +437,96 @@ void TurboAssembler::LoadRoot(Register destination, RootIndex index,
         MemOperand(kRootRegister, RootRegisterOffsetForRootIndex(index)), r0);
 }
 
+void TurboAssembler::LoadTaggedPointerField(const Register& destination,
+                                            const MemOperand& field_operand,
+                                            const Register& scratch) {
+  if (COMPRESS_POINTERS_BOOL) {
+    DecompressTaggedPointer(destination, field_operand);
+  } else {
+    LoadP(destination, field_operand, scratch);
+  }
+}
+
+void TurboAssembler::LoadAnyTaggedField(const Register& destination,
+                                        const MemOperand& field_operand,
+                                        const Register& scratch) {
+  if (COMPRESS_POINTERS_BOOL) {
+    DecompressAnyTagged(destination, field_operand);
+  } else {
+    LoadP(destination, field_operand, scratch);
+  }
+}
+
+void TurboAssembler::SmiUntag(Register dst, const MemOperand& src) {
+  if (SmiValuesAre31Bits()) {
+    LoadW(dst, src);
+  } else {
+    LoadP(dst, src);
+  }
+  SmiUntag(dst);
+}
+
+void TurboAssembler::SmiUntagField(Register dst, const MemOperand& src) {
+  SmiUntag(dst, src);
+}
+
+void TurboAssembler::StoreTaggedField(const Register& value,
+                                      const MemOperand& dst_field_operand,
+                                      const Register& scratch) {
+  if (COMPRESS_POINTERS_BOOL) {
+    RecordComment("[ StoreTagged");
+    StoreW(value, dst_field_operand);
+    RecordComment("]");
+  } else {
+    StoreP(value, dst_field_operand, scratch);
+  }
+}
+
+void TurboAssembler::DecompressTaggedSigned(Register destination,
+                                            Register src) {
+  RecordComment("[ DecompressTaggedSigned");
+  llgfr(destination, src);
+  RecordComment("]");
+}
+
+void TurboAssembler::DecompressTaggedSigned(Register destination,
+                                            MemOperand field_operand) {
+  RecordComment("[ DecompressTaggedSigned");
+  llgf(destination, field_operand);
+  RecordComment("]");
+}
+
+void TurboAssembler::DecompressTaggedPointer(Register destination,
+                                             Register source) {
+  RecordComment("[ DecompressTaggedPointer");
+  llgfr(destination, source);
+  agr(destination, kRootRegister);
+  RecordComment("]");
+}
+
+void TurboAssembler::DecompressTaggedPointer(Register destination,
+                                             MemOperand field_operand) {
+  RecordComment("[ DecompressTaggedPointer");
+  llgf(destination, field_operand);
+  agr(destination, kRootRegister);
+  RecordComment("]");
+}
+
+void TurboAssembler::DecompressAnyTagged(Register destination,
+                                         MemOperand field_operand) {
+  RecordComment("[ DecompressAnyTagged");
+  llgf(destination, field_operand);
+  agr(destination, kRootRegister);
+  RecordComment("]");
+}
+
+void TurboAssembler::DecompressAnyTagged(Register destination,
+                                         Register source) {
+  RecordComment("[ DecompressAnyTagged");
+  llgfr(destination, source);
+  agr(destination, kRootRegister);
+  RecordComment("]");
+}
 void MacroAssembler::RecordWriteField(Register object, int offset,
                                       Register value, Register dst,
                                       LinkRegisterStatus lr_status,
@@ -443,12 +544,12 @@ void MacroAssembler::RecordWriteField(Register object, int offset,
 
   // Although the object register is tagged, the offset is relative to the start
   // of the object, so so offset must be a multiple of kSystemPointerSize.
-  DCHECK(IsAligned(offset, kSystemPointerSize));
+  DCHECK(IsAligned(offset, kTaggedSize));
 
   lay(dst, MemOperand(object, offset - kHeapObjectTag));
   if (emit_debug_code()) {
     Label ok;
-    AndP(r0, dst, Operand(kSystemPointerSize - 1));
+    AndP(r0, dst, Operand(kTaggedSize - 1));
     beq(&ok, Label::kNear);
     stop();
     bind(&ok);
@@ -582,7 +683,8 @@ void MacroAssembler::RecordWrite(Register object, Register address,
                                  SmiCheck smi_check) {
   DCHECK(object != value);
   if (emit_debug_code()) {
-    CmpP(value, MemOperand(address));
+    LoadTaggedPointerField(r0, MemOperand(address));
+    CmpP(value, r0);
     Check(eq, AbortReason::kWrongAddressOrValuePassedToRecordWrite);
   }
 
@@ -670,23 +772,6 @@ void TurboAssembler::RestoreFrameStateForTailCall() {
   LoadP(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
 }
 
-int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
-  // The registers are pushed starting with the highest encoding,
-  // which means that lowest encodings are closest to the stack pointer.
-  RegList regs = kSafepointSavedRegisters;
-  int index = 0;
-
-  DCHECK(reg_code >= 0 && reg_code < kNumRegisters);
-
-  for (int16_t i = 0; i < reg_code; i++) {
-    if ((regs & (1 << i)) != 0) {
-      index++;
-    }
-  }
-
-  return index;
-}
-
 void TurboAssembler::CanonicalizeNaN(const DoubleRegister dst,
                                      const DoubleRegister src) {
   // Turn potential sNaN into qNaN
@@ -1348,17 +1433,17 @@ void MacroAssembler::InvokeFunctionCode(Register function, Register new_target,
   // allow recompilation to take effect without changing any of the
   // call sites.
   Register code = kJavaScriptCallCodeStartRegister;
-  LoadP(code, FieldMemOperand(function, JSFunction::kCodeOffset));
+  LoadTaggedPointerField(code,
+                         FieldMemOperand(function, JSFunction::kCodeOffset));
   if (flag == CALL_FUNCTION) {
     CallCodeObject(code);
   } else {
     DCHECK(flag == JUMP_FUNCTION);
     JumpCodeObject(code);
   }
-
-    // Continue here if InvokePrologue does handle the invocation due to
-    // mismatched parameter counts.
-    bind(&done);
+  // Continue here if InvokePrologue does handle the invocation due to
+  // mismatched parameter counts.
+  bind(&done);
 }
 
 void MacroAssembler::InvokeFunctionWithNewTarget(
@@ -1372,8 +1457,9 @@ void MacroAssembler::InvokeFunctionWithNewTarget(
 
   Register expected_reg = r4;
   Register temp_reg = r6;
-  LoadP(temp_reg, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
-  LoadP(cp, FieldMemOperand(r3, JSFunction::kContextOffset));
+  LoadTaggedPointerField(cp, FieldMemOperand(fun, JSFunction::kContextOffset));
+  LoadTaggedPointerField(
+      temp_reg, FieldMemOperand(fun, JSFunction::kSharedFunctionInfoOffset));
   LoadLogicalHalfWordP(
       expected_reg,
       FieldMemOperand(temp_reg,
@@ -1394,7 +1480,8 @@ void MacroAssembler::InvokeFunction(Register function,
   DCHECK_EQ(function, r3);
 
   // Get the function and setup the context.
-  LoadP(cp, FieldMemOperand(r3, JSFunction::kContextOffset));
+  LoadTaggedPointerField(cp,
+                         FieldMemOperand(function, JSFunction::kContextOffset));
 
   InvokeFunctionCode(r3, no_reg, expected_parameter_count,
                      actual_parameter_count, flag);
@@ -1464,7 +1551,11 @@ void MacroAssembler::CompareInstanceType(Register map, Register type_reg,
 }
 
 void MacroAssembler::CompareRoot(Register obj, RootIndex index) {
-  CmpP(obj, MemOperand(kRootRegister, RootRegisterOffsetForRootIndex(index)));
+  int32_t offset = RootRegisterOffsetForRootIndex(index);
+#ifdef V8_TARGET_BIG_ENDIAN
+  offset += (COMPRESS_POINTERS_BOOL ? kTaggedSize : 0);
+#endif
+  CompareTagged(obj, MemOperand(kRootRegister, offset));
 }
 
 void MacroAssembler::JumpIfIsInRange(Register value, unsigned lower_limit,
@@ -1651,14 +1742,16 @@ void TurboAssembler::Abort(AbortReason reason) {
 }
 
 void MacroAssembler::LoadMap(Register destination, Register object) {
-  LoadP(destination, FieldMemOperand(object, HeapObject::kMapOffset));
+  LoadTaggedPointerField(destination,
+                         FieldMemOperand(object, HeapObject::kMapOffset));
 }
 
 void MacroAssembler::LoadNativeContextSlot(int index, Register dst) {
   LoadMap(dst, cp);
-  LoadP(dst, FieldMemOperand(
-                 dst, Map::kConstructorOrBackPointerOrNativeContextOffset));
-  LoadP(dst, MemOperand(dst, Context::SlotOffset(index)));
+  LoadTaggedPointerField(
+      dst, FieldMemOperand(
+               dst, Map::kConstructorOrBackPointerOrNativeContextOffset));
+  LoadTaggedPointerField(dst, MemOperand(dst, Context::SlotOffset(index)));
 }
 
 void MacroAssembler::AssertNotSmi(Register object) {
@@ -1845,16 +1938,24 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    Register scratch = r6;
-    push(scratch);
+  Register addr_scratch = r1;
+  // See x64 code for reasoning about how to address the isolate data fields.
+  if (root_array_available()) {
+    LoadPC(r0);
+    StoreP(r0, MemOperand(kRootRegister,
+                          IsolateData::fast_c_call_caller_pc_offset()));
+    StoreP(fp, MemOperand(kRootRegister,
+                          IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
 
-    Move(scratch, ExternalReference::fast_c_call_caller_pc_address(isolate()));
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_pc_address(isolate()));
     LoadPC(r0);
-    StoreP(r0, MemOperand(scratch));
-    Move(scratch, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    StoreP(fp, MemOperand(scratch));
-    pop(scratch);
+    StoreP(r0, MemOperand(addr_scratch));
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    StoreP(fp, MemOperand(addr_scratch));
   }
 
   // Just call directly. The function called cannot cause a GC, or
@@ -1868,15 +1969,19 @@ void TurboAssembler::CallCFunctionHelper(Register function,
 
   Call(dest);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
-    Register scratch1 = r6;
-    Register scratch2 = r7;
-    Push(scratch1, scratch2);
-    Move(scratch1, ExternalReference::fast_c_call_caller_fp_address(isolate()));
-    lghi(scratch2, Operand::Zero());
-    StoreP(scratch2, MemOperand(scratch1));
-    Pop(scratch1, scratch2);
+  // We don't unset the PC; the FP is the source of truth.
+  Register zero_scratch = r0;
+  lghi(zero_scratch, Operand::Zero());
+
+  if (root_array_available()) {
+    StoreP(
+        zero_scratch,
+        MemOperand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()));
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    Move(addr_scratch,
+         ExternalReference::fast_c_call_caller_fp_address(isolate()));
+    StoreP(zero_scratch, MemOperand(addr_scratch));
   }
 
   int stack_passed_arguments =
@@ -3757,9 +3862,15 @@ void TurboAssembler::LoadFloat32ConvertToDouble(DoubleRegister dst,
   ldebr(dst, dst);
 }
 
-void TurboAssembler::LoadSimd128(Simd128Register dst, const MemOperand& mem) {
-  DCHECK(is_uint12(mem.offset()));
-  vl(dst, mem, Condition(0));
+void TurboAssembler::LoadSimd128(Simd128Register dst, const MemOperand& mem,
+                                 Register scratch) {
+  if (is_uint12(mem.offset())) {
+    vl(dst, mem, Condition(0));
+  } else {
+    DCHECK(is_int20(mem.offset()));
+    lay(scratch, mem);
+    vl(dst, MemOperand(scratch), Condition(0));
+  }
 }
 
 // Store Double Precision (64-bit) Floating Point number to memory
@@ -3789,9 +3900,15 @@ void TurboAssembler::StoreDoubleAsFloat32(DoubleRegister src,
   StoreFloat32(scratch, mem);
 }
 
-void TurboAssembler::StoreSimd128(Simd128Register src, const MemOperand& mem) {
-  DCHECK(is_uint12(mem.offset()));
-  vst(src, mem, Condition(0));
+void TurboAssembler::StoreSimd128(Simd128Register src, const MemOperand& mem,
+                                  Register scratch) {
+  if (is_uint12(mem.offset())) {
+    vst(src, mem, Condition(0));
+  } else {
+    DCHECK(is_int20(mem.offset()));
+    lay(scratch, mem);
+    vst(src, MemOperand(scratch), Condition(0));
+  }
 }
 
 void TurboAssembler::AddFloat32(DoubleRegister dst, const MemOperand& opnd,
@@ -4197,13 +4314,17 @@ void TurboAssembler::SwapFloat32(DoubleRegister src, MemOperand dst,
 }
 
 void TurboAssembler::SwapFloat32(MemOperand src, MemOperand dst,
-                                 DoubleRegister scratch_0,
-                                 DoubleRegister scratch_1) {
-  DCHECK(!AreAliased(scratch_0, scratch_1));
-  LoadFloat32(scratch_0, src);
-  LoadFloat32(scratch_1, dst);
-  StoreFloat32(scratch_0, dst);
-  StoreFloat32(scratch_1, src);
+                                 DoubleRegister scratch) {
+  // push d0, to be used as scratch
+  lay(sp, MemOperand(sp, -kDoubleSize));
+  StoreDouble(d0, MemOperand(sp));
+  LoadFloat32(scratch, src);
+  LoadFloat32(d0, dst);
+  StoreFloat32(scratch, dst);
+  StoreFloat32(d0, src);
+  // restore d0
+  LoadDouble(d0, MemOperand(sp));
+  lay(sp, MemOperand(sp, kDoubleSize));
 }
 
 void TurboAssembler::SwapDouble(DoubleRegister src, DoubleRegister dst,
@@ -4224,13 +4345,17 @@ void TurboAssembler::SwapDouble(DoubleRegister src, MemOperand dst,
 }
 
 void TurboAssembler::SwapDouble(MemOperand src, MemOperand dst,
-                                DoubleRegister scratch_0,
-                                DoubleRegister scratch_1) {
-  DCHECK(!AreAliased(scratch_0, scratch_1));
-  LoadDouble(scratch_0, src);
-  LoadDouble(scratch_1, dst);
-  StoreDouble(scratch_0, dst);
-  StoreDouble(scratch_1, src);
+                                DoubleRegister scratch) {
+  // push d0, to be used as scratch
+  lay(sp, MemOperand(sp, -kDoubleSize));
+  StoreDouble(d0, MemOperand(sp));
+  LoadDouble(scratch, src);
+  LoadDouble(d0, dst);
+  StoreDouble(scratch, dst);
+  StoreDouble(d0, src);
+  // restore d0
+  LoadDouble(d0, MemOperand(sp));
+  lay(sp, MemOperand(sp, kDoubleSize));
 }
 
 void TurboAssembler::SwapSimd128(Simd128Register src, Simd128Register dst,
@@ -4245,17 +4370,22 @@ void TurboAssembler::SwapSimd128(Simd128Register src, MemOperand dst,
                                  Simd128Register scratch) {
   DCHECK(!AreAliased(src, scratch));
   vlr(scratch, src, Condition(0), Condition(0), Condition(0));
-  LoadSimd128(src, dst);
-  StoreSimd128(scratch, dst);
+  LoadSimd128(src, dst, ip);
+  StoreSimd128(scratch, dst, ip);
 }
 
 void TurboAssembler::SwapSimd128(MemOperand src, MemOperand dst,
-                                 Simd128Register scratch_0,
-                                 Simd128Register scratch_1) {
-  LoadSimd128(scratch_0, src);
-  LoadSimd128(scratch_1, dst);
-  StoreSimd128(scratch_0, dst);
-  StoreSimd128(scratch_1, src);
+                                 Simd128Register scratch) {
+  // push d0, to be used as scratch
+  lay(sp, MemOperand(sp, -kSimd128Size));
+  StoreSimd128(d0, MemOperand(sp), ip);
+  LoadSimd128(scratch, src, ip);
+  LoadSimd128(d0, dst, ip);
+  StoreSimd128(scratch, dst, ip);
+  StoreSimd128(d0, src, ip);
+  // restore d0
+  LoadSimd128(d0, MemOperand(sp), ip);
+  lay(sp, MemOperand(sp, kSimd128Size));
 }
 
 void TurboAssembler::ResetSpeculationPoisonRegister() {
@@ -4286,20 +4416,17 @@ void TurboAssembler::LoadEntryFromBuiltinIndex(Register builtin_index) {
   STATIC_ASSERT(kSystemPointerSize == 8);
   STATIC_ASSERT(kSmiTagSize == 1);
   STATIC_ASSERT(kSmiTag == 0);
-
   // The builtin_index register contains the builtin index as a Smi.
-  // Untagging is folded into the indexing operand below.
-#if defined(V8_COMPRESS_POINTERS) || defined(V8_31BIT_SMIS_ON_64BIT_ARCH)
-  STATIC_ASSERT(kSmiShiftSize == 0);
-  ShiftLeftP(builtin_index, builtin_index,
-             Operand(kSystemPointerSizeLog2 - kSmiShift));
-#else
-  ShiftRightArithP(builtin_index, builtin_index,
-                   Operand(kSmiShift - kSystemPointerSizeLog2));
-#endif
-  AddP(builtin_index, builtin_index,
-       Operand(IsolateData::builtin_entry_table_offset()));
-  LoadP(builtin_index, MemOperand(kRootRegister, builtin_index));
+  if (SmiValuesAre32Bits()) {
+    ShiftRightArithP(builtin_index, builtin_index,
+                     Operand(kSmiShift - kSystemPointerSizeLog2));
+  } else {
+    DCHECK(SmiValuesAre31Bits());
+    ShiftLeftP(builtin_index, builtin_index,
+               Operand(kSystemPointerSizeLog2 - kSmiShift));
+  }
+  LoadP(builtin_index, MemOperand(kRootRegister, builtin_index,
+                                  IsolateData::builtin_entry_table_offset()));
 }
 
 void TurboAssembler::CallBuiltinByIndex(Register builtin_index) {
@@ -4382,7 +4509,9 @@ void TurboAssembler::StoreReturnAddressAndCall(Register target) {
   bind(&return_label);
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
 
   // Save the deopt id in r10 (we don't need the roots array from now on).
@@ -4392,6 +4521,7 @@ void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
 }
 
 void TurboAssembler::Trap() { stop(); }
+void TurboAssembler::DebugBreak() { stop(); }
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/codegen/s390/macro-assembler-s390.h b/deps/v8/src/codegen/s390/macro-assembler-s390.h
index d0d6ca6c06..8b267eb2c6 100644
--- a/deps/v8/src/codegen/s390/macro-assembler-s390.h
+++ b/deps/v8/src/codegen/s390/macro-assembler-s390.h
@@ -153,7 +153,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Ret() { b(r14); }
   void Ret(Condition cond) { b(cond, r14); }
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   // Emit code to discard a non-negative number of pointer-sized elements
   // from the stack, clobbering only the sp register.
@@ -178,7 +179,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   // Register move. May do nothing if the registers are identical.
   void Move(Register dst, Smi smi) { LoadSmiLiteral(dst, smi); }
-  void Move(Register dst, Handle<HeapObject> value);
+  void Move(Register dst, Handle<HeapObject> source,
+            RelocInfo::Mode rmode = RelocInfo::FULL_EMBEDDED_OBJECT);
   void Move(Register dst, ExternalReference reference);
   void Move(Register dst, Register src, Condition cond = al);
   void Move(DoubleRegister dst, DoubleRegister src);
@@ -417,7 +419,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void LoadDouble(DoubleRegister dst, const MemOperand& opnd);
   void LoadFloat32(DoubleRegister dst, const MemOperand& opnd);
   void LoadFloat32ConvertToDouble(DoubleRegister dst, const MemOperand& mem);
-  void LoadSimd128(Simd128Register dst, const MemOperand& mem);
+  void LoadSimd128(Simd128Register dst, const MemOperand& mem,
+                   Register scratch);
 
   void AddFloat32(DoubleRegister dst, const MemOperand& opnd,
                   DoubleRegister scratch);
@@ -449,7 +452,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void StoreFloat32(DoubleRegister dst, const MemOperand& opnd);
   void StoreDoubleAsFloat32(DoubleRegister src, const MemOperand& mem,
                             DoubleRegister scratch);
-  void StoreSimd128(Simd128Register src, const MemOperand& mem);
+  void StoreSimd128(Simd128Register src, const MemOperand& mem,
+                    Register scratch);
 
   void Branch(Condition c, const Operand& opnd);
   void BranchOnCount(Register r1, Label* l);
@@ -782,19 +786,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void SwapFloat32(DoubleRegister src, DoubleRegister dst,
                    DoubleRegister scratch);
   void SwapFloat32(DoubleRegister src, MemOperand dst, DoubleRegister scratch);
-  void SwapFloat32(MemOperand src, MemOperand dst, DoubleRegister scratch_0,
-                   DoubleRegister scratch_1);
+  void SwapFloat32(MemOperand src, MemOperand dst, DoubleRegister scratch);
   void SwapDouble(DoubleRegister src, DoubleRegister dst,
                   DoubleRegister scratch);
   void SwapDouble(DoubleRegister src, MemOperand dst, DoubleRegister scratch);
-  void SwapDouble(MemOperand src, MemOperand dst, DoubleRegister scratch_0,
-                  DoubleRegister scratch_1);
+  void SwapDouble(MemOperand src, MemOperand dst, DoubleRegister scratch);
   void SwapSimd128(Simd128Register src, Simd128Register dst,
                    Simd128Register scratch);
   void SwapSimd128(Simd128Register src, MemOperand dst,
                    Simd128Register scratch);
-  void SwapSimd128(MemOperand src, MemOperand dst, Simd128Register scratch_0,
-                   Simd128Register scratch_1);
+  void SwapSimd128(MemOperand src, MemOperand dst, Simd128Register scratch);
 
   // Cleanse pointer address on 31bit by zero out top  bit.
   // This is a NOP on 64-bit.
@@ -849,6 +850,7 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void MovFromFloatResult(DoubleRegister dst);
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Emit code for a truncating division by a constant. The dividend register is
   // unchanged and ip gets clobbered. Dividend and result must be different.
@@ -971,16 +973,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
     // High bits must be identical to fit into an 32-bit integer
     cgfr(value, value);
   }
-  void SmiUntag(Register reg, int scale = 0) { SmiUntag(reg, reg, scale); }
+  void SmiUntag(Register reg) { SmiUntag(reg, reg); }
 
-  void SmiUntag(Register dst, Register src, int scale = 0) {
-    if (scale > kSmiShift) {
-      ShiftLeftP(dst, src, Operand(scale - kSmiShift));
-    } else if (scale < kSmiShift) {
-      ShiftRightArithP(dst, src, Operand(kSmiShift - scale));
+  void SmiUntag(Register dst, const MemOperand& src);
+  void SmiUntag(Register dst, Register src) {
+    if (SmiValuesAre31Bits()) {
+      ShiftRightArith(dst, src, Operand(kSmiShift));
     } else {
-      // do nothing
+      ShiftRightArithP(dst, src, Operand(kSmiShift));
     }
+    lgfr(dst, dst);
   }
 
   // Activation support.
@@ -996,11 +998,50 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void ComputeCodeStartAddress(Register dst);
   void LoadPC(Register dst);
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
   // Generates an instruction sequence s.t. the return address points to the
   // instruction following the call.
   // The return address on the stack is used by frame iteration.
   void StoreReturnAddressAndCall(Register target);
 
+  // ---------------------------------------------------------------------------
+  // Pointer compression Support
+
+  // Loads a field containing a HeapObject and decompresses it if pointer
+  // compression is enabled.
+  void LoadTaggedPointerField(const Register& destination,
+                              const MemOperand& field_operand,
+                              const Register& scratch = no_reg);
+
+  // Loads a field containing any tagged value and decompresses it if necessary.
+  void LoadAnyTaggedField(const Register& destination,
+                          const MemOperand& field_operand,
+                          const Register& scratch = no_reg);
+
+  // Loads a field containing smi value and untags it.
+  void SmiUntagField(Register dst, const MemOperand& src);
+
+  // Compresses and stores tagged value to given on-heap location.
+  void StoreTaggedField(const Register& value,
+                        const MemOperand& dst_field_operand,
+                        const Register& scratch = no_reg);
+
+  void DecompressTaggedSigned(Register destination, MemOperand field_operand);
+  void DecompressTaggedSigned(Register destination, Register src);
+  void DecompressTaggedPointer(Register destination, MemOperand field_operand);
+  void DecompressTaggedPointer(Register destination, Register source);
+  void DecompressAnyTagged(Register destination, MemOperand field_operand);
+  void DecompressAnyTagged(Register destination, Register source);
+
  private:
   static const int kSmiShift = kSmiTagSize + kSmiShiftSize;
 
@@ -1072,6 +1113,15 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
     Push(r0);
   }
 
+  template <class T>
+  void CompareTagged(Register src1, T src2) {
+    if (COMPRESS_POINTERS_BOOL) {
+      Cmp32(src1, src2);
+    } else {
+      CmpP(src1, src2);
+    }
+  }
+
   // Jump to a runtime routine.
   void JumpToExternalReference(const ExternalReference& builtin,
                                bool builtin_exit_frame = false);
@@ -1278,13 +1328,6 @@ class V8_EXPORT_PRIVATE MacroAssembler : public TurboAssembler {
                       Register actual_parameter_count, Label* done,
                       InvokeFlag flag);
 
-  // Compute memory operands for safepoint stack slots.
-  static int SafepointRegisterStackIndex(int reg_code);
-
-  // Needs access to SafepointRegisterStackIndex for compiled frame
-  // traversal.
-  friend class StandardFrame;
-
   DISALLOW_IMPLICIT_CONSTRUCTORS(MacroAssembler);
 };
 
diff --git a/deps/v8/src/codegen/s390/register-s390.h b/deps/v8/src/codegen/s390/register-s390.h
index dddd16d89c..21094ef3bc 100644
--- a/deps/v8/src/codegen/s390/register-s390.h
+++ b/deps/v8/src/codegen/s390/register-s390.h
@@ -38,7 +38,6 @@ namespace internal {
 
 // Register list in load/store instructions
 // Note that the bit values must match those used in actual instruction encoding
-const int kNumRegs = 16;
 
 // Caller-saved/arguments registers
 const RegList kJSCallerSaved = 1 << 1 | 1 << 2 |  // r2  a1
@@ -87,17 +86,6 @@ const RegList kCalleeSavedDoubles = 1 << 8 |   // d8
 
 const int kNumCalleeSavedDoubles = 8;
 
-// Number of registers for which space is reserved in safepoints. Must be a
-// multiple of 8.
-// TODO(regis): Only 8 registers may actually be sufficient. Revisit.
-const int kNumSafepointRegisters = 16;
-
-// Define the list of registers actually saved at safepoints.
-// Note that the number of saved registers may be smaller than the reserved
-// space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
-const RegList kSafepointSavedRegisters = kJSCallerSaved | kCalleeSaved;
-const int kNumSafepointSavedRegisters = kNumJSCallerSaved + kNumCalleeSaved;
-
 // The following constants describe the stack frame linkage area as
 // defined by the ABI.
 
diff --git a/deps/v8/src/codegen/source-position-table.cc b/deps/v8/src/codegen/source-position-table.cc
index b0c9d95456..0f03867331 100644
--- a/deps/v8/src/codegen/source-position-table.cc
+++ b/deps/v8/src/codegen/source-position-table.cc
@@ -4,6 +4,8 @@
 
 #include "src/codegen/source-position-table.h"
 
+#include "src/base/export-template.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/objects.h"
 
@@ -153,8 +155,9 @@ void SourcePositionTableBuilder::AddEntry(const PositionTableEntry& entry) {
 #endif
 }
 
+template <typename LocalIsolate>
 Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
-    Isolate* isolate) {
+    LocalIsolate* isolate) {
   if (bytes_.empty()) return isolate->factory()->empty_byte_array();
   DCHECK(!Omit());
 
@@ -165,7 +168,9 @@ Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
 #ifdef ENABLE_SLOW_DCHECKS
   // Brute force testing: Record all positions and decode
   // the entire table to verify they are identical.
-  SourcePositionTableIterator it(*table, SourcePositionTableIterator::kAll);
+  SourcePositionTableIterator it(
+      *table, SourcePositionTableIterator::kAll,
+      SourcePositionTableIterator::kDontSkipFunctionEntry);
   CheckTableEquals(raw_entries_, &it);
   // No additional source positions after creating the table.
   mode_ = OMIT_SOURCE_POSITIONS;
@@ -173,6 +178,13 @@ Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
   return table;
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
+        Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> SourcePositionTableBuilder::ToSourcePositionTable(
+        OffThreadIsolate* isolate);
+
 OwnedVector<byte> SourcePositionTableBuilder::ToSourcePositionTableVector() {
   if (bytes_.empty()) return OwnedVector<byte>();
   DCHECK(!Omit());
@@ -182,8 +194,9 @@ OwnedVector<byte> SourcePositionTableBuilder::ToSourcePositionTableVector() {
 #ifdef ENABLE_SLOW_DCHECKS
   // Brute force testing: Record all positions and decode
   // the entire table to verify they are identical.
-  SourcePositionTableIterator it(table.as_vector(),
-                                 SourcePositionTableIterator::kAll);
+  SourcePositionTableIterator it(
+      table.as_vector(), SourcePositionTableIterator::kAll,
+      SourcePositionTableIterator::kDontSkipFunctionEntry);
   CheckTableEquals(raw_entries_, &it);
   // No additional source positions after creating the table.
   mode_ = OMIT_SOURCE_POSITIONS;
@@ -191,16 +204,30 @@ OwnedVector<byte> SourcePositionTableBuilder::ToSourcePositionTableVector() {
   return table;
 }
 
-SourcePositionTableIterator::SourcePositionTableIterator(ByteArray byte_array,
-                                                         IterationFilter filter)
-    : raw_table_(VectorFromByteArray(byte_array)), filter_(filter) {
+void SourcePositionTableIterator::Initialize() {
   Advance();
+  if (function_entry_filter_ == kSkipFunctionEntry &&
+      current_.code_offset == kFunctionEntryBytecodeOffset && !done()) {
+    Advance();
+  }
 }
 
 SourcePositionTableIterator::SourcePositionTableIterator(
-    Handle<ByteArray> byte_array, IterationFilter filter)
-    : table_(byte_array), filter_(filter) {
-  Advance();
+    ByteArray byte_array, IterationFilter iteration_filter,
+    FunctionEntryFilter function_entry_filter)
+    : raw_table_(VectorFromByteArray(byte_array)),
+      iteration_filter_(iteration_filter),
+      function_entry_filter_(function_entry_filter) {
+  Initialize();
+}
+
+SourcePositionTableIterator::SourcePositionTableIterator(
+    Handle<ByteArray> byte_array, IterationFilter iteration_filter,
+    FunctionEntryFilter function_entry_filter)
+    : table_(byte_array),
+      iteration_filter_(iteration_filter),
+      function_entry_filter_(function_entry_filter) {
+  Initialize();
 #ifdef DEBUG
   // We can enable allocation because we keep the table in a handle.
   no_gc.Release();
@@ -208,9 +235,12 @@ SourcePositionTableIterator::SourcePositionTableIterator(
 }
 
 SourcePositionTableIterator::SourcePositionTableIterator(
-    Vector<const byte> bytes, IterationFilter filter)
-    : raw_table_(bytes), filter_(filter) {
-  Advance();
+    Vector<const byte> bytes, IterationFilter iteration_filter,
+    FunctionEntryFilter function_entry_filter)
+    : raw_table_(bytes),
+      iteration_filter_(iteration_filter),
+      function_entry_filter_(function_entry_filter) {
+  Initialize();
 #ifdef DEBUG
   // We can enable allocation because the underlying vector does not move.
   no_gc.Release();
@@ -231,9 +261,10 @@ void SourcePositionTableIterator::Advance() {
       DecodeEntry(bytes, &index_, &tmp);
       AddAndSetEntry(&current_, tmp);
       SourcePosition p = source_position();
-      filter_satisfied = (filter_ == kAll) ||
-                         (filter_ == kJavaScriptOnly && p.IsJavaScript()) ||
-                         (filter_ == kExternalOnly && p.IsExternal());
+      filter_satisfied =
+          (iteration_filter_ == kAll) ||
+          (iteration_filter_ == kJavaScriptOnly && p.IsJavaScript()) ||
+          (iteration_filter_ == kExternalOnly && p.IsExternal());
     }
   }
 }
diff --git a/deps/v8/src/codegen/source-position-table.h b/deps/v8/src/codegen/source-position-table.h
index b3bba3bc8a..024eca54fa 100644
--- a/deps/v8/src/codegen/source-position-table.h
+++ b/deps/v8/src/codegen/source-position-table.h
@@ -5,6 +5,7 @@
 #ifndef V8_CODEGEN_SOURCE_POSITION_TABLE_H_
 #define V8_CODEGEN_SOURCE_POSITION_TABLE_H_
 
+#include "src/base/export-template.h"
 #include "src/codegen/source-position.h"
 #include "src/common/assert-scope.h"
 #include "src/common/checks.h"
@@ -23,7 +24,9 @@ class Zone;
 
 struct PositionTableEntry {
   PositionTableEntry()
-      : code_offset(0), source_position(0), is_statement(false) {}
+      : code_offset(kFunctionEntryBytecodeOffset),
+        source_position(0),
+        is_statement(false) {}
   PositionTableEntry(int offset, int64_t source, bool statement)
       : code_offset(offset), source_position(source), is_statement(statement) {}
 
@@ -51,7 +54,9 @@ class V8_EXPORT_PRIVATE SourcePositionTableBuilder {
   void AddPosition(size_t code_offset, SourcePosition source_position,
                    bool is_statement);
 
-  Handle<ByteArray> ToSourcePositionTable(Isolate* isolate);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
   OwnedVector<byte> ToSourcePositionTableVector();
 
   inline bool Omit() const { return mode_ != RECORD_SOURCE_POSITIONS; }
@@ -70,13 +75,23 @@ class V8_EXPORT_PRIVATE SourcePositionTableBuilder {
 
 class V8_EXPORT_PRIVATE SourcePositionTableIterator {
  public:
+  // Filter that applies when advancing the iterator. If the filter isn't
+  // satisfied, we advance the iterator again.
   enum IterationFilter { kJavaScriptOnly = 0, kExternalOnly = 1, kAll = 2 };
+  // Filter that applies only to the first entry of the source position table.
+  // If it is kSkipFunctionEntry, it will skip the FunctionEntry entry if it
+  // exists.
+  enum FunctionEntryFilter {
+    kSkipFunctionEntry = 0,
+    kDontSkipFunctionEntry = 1
+  };
 
   // Used for saving/restoring the iterator.
   struct IndexAndPositionState {
     int index_;
     PositionTableEntry position_;
-    IterationFilter filter_;
+    IterationFilter iteration_filter_;
+    FunctionEntryFilter function_entry_filter_;
   };
 
   // We expose three flavours of the iterator, depending on the argument passed
@@ -85,18 +100,23 @@ class V8_EXPORT_PRIVATE SourcePositionTableIterator {
   // Handlified iterator allows allocation, but it needs a handle (and thus
   // a handle scope). This is the preferred version.
   explicit SourcePositionTableIterator(
-      Handle<ByteArray> byte_array, IterationFilter filter = kJavaScriptOnly);
+      Handle<ByteArray> byte_array,
+      IterationFilter iteration_filter = kJavaScriptOnly,
+      FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
 
   // Non-handlified iterator does not need a handle scope, but it disallows
   // allocation during its lifetime. This is useful if there is no handle
   // scope around.
   explicit SourcePositionTableIterator(
-      ByteArray byte_array, IterationFilter filter = kJavaScriptOnly);
+      ByteArray byte_array, IterationFilter iteration_filter = kJavaScriptOnly,
+      FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
 
   // Handle-safe iterator based on an a vector located outside the garbage
   // collected heap, allows allocation during its lifetime.
   explicit SourcePositionTableIterator(
-      Vector<const byte> bytes, IterationFilter filter = kJavaScriptOnly);
+      Vector<const byte> bytes,
+      IterationFilter iteration_filter = kJavaScriptOnly,
+      FunctionEntryFilter function_entry_filter = kSkipFunctionEntry);
 
   void Advance();
 
@@ -114,22 +134,30 @@ class V8_EXPORT_PRIVATE SourcePositionTableIterator {
   }
   bool done() const { return index_ == kDone; }
 
-  IndexAndPositionState GetState() const { return {index_, current_, filter_}; }
+  IndexAndPositionState GetState() const {
+    return {index_, current_, iteration_filter_, function_entry_filter_};
+  }
 
   void RestoreState(const IndexAndPositionState& saved_state) {
     index_ = saved_state.index_;
     current_ = saved_state.position_;
-    filter_ = saved_state.filter_;
+    iteration_filter_ = saved_state.iteration_filter_;
+    function_entry_filter_ = saved_state.function_entry_filter_;
   }
 
  private:
+  // Initializes the source position interator with the first valid bytecode.
+  // Also sets the FunctionEntry SourcePosition if it exists.
+  void Initialize();
+
   static const int kDone = -1;
 
   Vector<const byte> raw_table_;
   Handle<ByteArray> table_;
   int index_ = 0;
   PositionTableEntry current_;
-  IterationFilter filter_;
+  IterationFilter iteration_filter_;
+  FunctionEntryFilter function_entry_filter_;
   DISALLOW_HEAP_ALLOCATION(no_gc)
 };
 
diff --git a/deps/v8/src/codegen/tnode.h b/deps/v8/src/codegen/tnode.h
index 64a4272d17..ecf9afab48 100644
--- a/deps/v8/src/codegen/tnode.h
+++ b/deps/v8/src/codegen/tnode.h
@@ -13,6 +13,8 @@ namespace internal {
 class HeapNumber;
 class BigInt;
 class Object;
+class Smi;
+class TaggedIndex;
 
 namespace compiler {
 
@@ -130,6 +132,10 @@ template <>
 struct MachineTypeOf<Smi> {
   static constexpr MachineType value = MachineType::TaggedSigned();
 };
+template <>
+struct MachineTypeOf<TaggedIndex> {
+  static constexpr MachineType value = MachineType::Pointer();
+};
 template <class HeapObjectSubtype>
 struct MachineTypeOf<HeapObjectSubtype,
                      typename std::enable_if<std::is_base_of<
diff --git a/deps/v8/src/codegen/turbo-assembler.h b/deps/v8/src/codegen/turbo-assembler.h
index bb38eb5554..26cf12d4eb 100644
--- a/deps/v8/src/codegen/turbo-assembler.h
+++ b/deps/v8/src/codegen/turbo-assembler.h
@@ -86,6 +86,7 @@ class V8_EXPORT_PRIVATE TurboAssemblerBase : public Assembler {
   virtual void LoadRoot(Register destination, RootIndex index) = 0;
 
   virtual void Trap() = 0;
+  virtual void DebugBreak() = 0;
 
   static int32_t RootRegisterOffsetForRootIndex(RootIndex root_index);
   static int32_t RootRegisterOffsetForBuiltinIndex(int builtin_index);
diff --git a/deps/v8/src/codegen/x64/assembler-x64.cc b/deps/v8/src/codegen/x64/assembler-x64.cc
index a058cbb24e..1106626a13 100644
--- a/deps/v8/src/codegen/x64/assembler-x64.cc
+++ b/deps/v8/src/codegen/x64/assembler-x64.cc
@@ -3340,26 +3340,6 @@ void Assembler::cvtss2sd(XMMRegister dst, Operand src) {
   emit_sse_operand(dst, src);
 }
 
-void Assembler::cvtsd2ss(XMMRegister dst, XMMRegister src) {
-  DCHECK(!IsEnabled(AVX));
-  EnsureSpace ensure_space(this);
-  emit(0xF2);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x5A);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::cvtsd2ss(XMMRegister dst, Operand src) {
-  DCHECK(!IsEnabled(AVX));
-  EnsureSpace ensure_space(this);
-  emit(0xF2);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x5A);
-  emit_sse_operand(dst, src);
-}
-
 void Assembler::cvtsd2si(Register dst, XMMRegister src) {
   DCHECK(!IsEnabled(AVX));
   EnsureSpace ensure_space(this);
@@ -3380,62 +3360,6 @@ void Assembler::cvtsd2siq(Register dst, XMMRegister src) {
   emit_sse_operand(dst, src);
 }
 
-void Assembler::andpd(XMMRegister dst, XMMRegister src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x54);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::andpd(XMMRegister dst, Operand src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x54);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::orpd(XMMRegister dst, XMMRegister src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x56);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::orpd(XMMRegister dst, Operand src) {
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x56);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::xorpd(XMMRegister dst, XMMRegister src) {
-  DCHECK(!IsEnabled(AVX));
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x57);
-  emit_sse_operand(dst, src);
-}
-
-void Assembler::xorpd(XMMRegister dst, Operand src) {
-  DCHECK(!IsEnabled(AVX));
-  EnsureSpace ensure_space(this);
-  emit(0x66);
-  emit_optional_rex_32(dst, src);
-  emit(0x0F);
-  emit(0x57);
-  emit_sse_operand(dst, src);
-}
-
 void Assembler::haddps(XMMRegister dst, XMMRegister src) {
   DCHECK(IsEnabled(SSE3));
   EnsureSpace ensure_space(this);
diff --git a/deps/v8/src/codegen/x64/assembler-x64.h b/deps/v8/src/codegen/x64/assembler-x64.h
index 2392146065..3f58e3b428 100644
--- a/deps/v8/src/codegen/x64/assembler-x64.h
+++ b/deps/v8/src/codegen/x64/assembler-x64.h
@@ -901,6 +901,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   SSE_INSTRUCTION_LIST_SS(DECLARE_SSE2_INSTRUCTION)
   SSE2_INSTRUCTION_LIST(DECLARE_SSE2_INSTRUCTION)
   SSE2_INSTRUCTION_LIST_SD(DECLARE_SSE2_INSTRUCTION)
+  SSE2_UNOP_INSTRUCTION_LIST(DECLARE_SSE2_INSTRUCTION)
 #undef DECLARE_SSE2_INSTRUCTION
 
   void sse2_instr(XMMRegister reg, byte imm8, byte prefix, byte escape,
@@ -928,6 +929,17 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   SSE2_INSTRUCTION_LIST(DECLARE_SSE2_AVX_INSTRUCTION)
 #undef DECLARE_SSE2_AVX_INSTRUCTION
 
+#define DECLARE_SSE2_UNOP_AVX_INSTRUCTION(instruction, prefix, escape, opcode) \
+  void v##instruction(XMMRegister dst, XMMRegister src) {                      \
+    vpd(0x##opcode, dst, xmm0, src);                                           \
+  }                                                                            \
+  void v##instruction(XMMRegister dst, Operand src) {                          \
+    vpd(0x##opcode, dst, xmm0, src);                                           \
+  }
+
+  SSE2_UNOP_INSTRUCTION_LIST(DECLARE_SSE2_UNOP_AVX_INSTRUCTION)
+#undef DECLARE_SSE2_UNOP_AVX_INSTRUCTION
+
   // SSE3
   void lddqu(XMMRegister dst, Operand src);
   void movddup(XMMRegister dst, Operand src);
@@ -949,6 +961,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   SSSE3_INSTRUCTION_LIST(DECLARE_SSSE3_INSTRUCTION)
+  SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSSE3_INSTRUCTION)
 #undef DECLARE_SSSE3_INSTRUCTION
 
   // SSE4
@@ -972,7 +985,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   }
 
   SSE4_INSTRUCTION_LIST(DECLARE_SSE4_INSTRUCTION)
-  SSE4_PMOV_INSTRUCTION_LIST(DECLARE_SSE4_INSTRUCTION)
+  SSE4_UNOP_INSTRUCTION_LIST(DECLARE_SSE4_INSTRUCTION)
   DECLARE_SSE4_INSTRUCTION(blendvpd, 66, 0F, 38, 15)
 #undef DECLARE_SSE4_INSTRUCTION
 
@@ -1021,6 +1034,18 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   SSE4_2_INSTRUCTION_LIST(DECLARE_SSE34_AVX_INSTRUCTION)
 #undef DECLARE_SSE34_AVX_INSTRUCTION
 
+#define DECLARE_SSSE3_UNOP_AVX_INSTRUCTION(instruction, prefix, escape1,     \
+                                           escape2, opcode)                  \
+  void v##instruction(XMMRegister dst, XMMRegister src) {                    \
+    vinstr(0x##opcode, dst, xmm0, src, k##prefix, k##escape1##escape2, kW0); \
+  }                                                                          \
+  void v##instruction(XMMRegister dst, Operand src) {                        \
+    vinstr(0x##opcode, dst, xmm0, src, k##prefix, k##escape1##escape2, kW0); \
+  }
+
+  SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSSE3_UNOP_AVX_INSTRUCTION)
+#undef DECLARE_SSSE3_UNOP_AVX_INSTRUCTION
+
   void vblendvpd(XMMRegister dst, XMMRegister src1, XMMRegister src2,
                  XMMRegister mask) {
     vinstr(0x4B, dst, src1, src2, k66, k0F3A, kW0);
@@ -1036,7 +1061,7 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void v##instruction(XMMRegister dst, Operand src) {                        \
     vinstr(0x##opcode, dst, xmm0, src, k##prefix, k##escape1##escape2, kW0); \
   }
-  SSE4_PMOV_INSTRUCTION_LIST(DECLARE_SSE4_PMOV_AVX_INSTRUCTION)
+  SSE4_UNOP_INSTRUCTION_LIST(DECLARE_SSE4_PMOV_AVX_INSTRUCTION)
 #undef DECLARE_SSE4_PMOV_AVX_INSTRUCTION
 
   void movd(XMMRegister dst, Register src);
@@ -1086,19 +1111,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
 
   void cvtss2sd(XMMRegister dst, XMMRegister src);
   void cvtss2sd(XMMRegister dst, Operand src);
-  void cvtsd2ss(XMMRegister dst, XMMRegister src);
-  void cvtsd2ss(XMMRegister dst, Operand src);
 
   void cvtsd2si(Register dst, XMMRegister src);
   void cvtsd2siq(Register dst, XMMRegister src);
 
-  void andpd(XMMRegister dst, XMMRegister src);
-  void andpd(XMMRegister dst, Operand src);
-  void orpd(XMMRegister dst, XMMRegister src);
-  void orpd(XMMRegister dst, Operand src);
-  void xorpd(XMMRegister dst, XMMRegister src);
-  void xorpd(XMMRegister dst, Operand src);
-
   void haddps(XMMRegister dst, XMMRegister src);
   void haddps(XMMRegister dst, Operand src);
 
@@ -1224,10 +1240,6 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     impl(opcode, dst, src1, src2);                                  \
   }
 
-  AVX_3(vandpd, 0x54, vpd)
-  AVX_3(vorpd, 0x56, vpd)
-  AVX_3(vxorpd, 0x57, vpd)
-  AVX_3(vcvtsd2ss, 0x5a, vsd)
   AVX_3(vhaddps, 0x7c, vsd)
 
 #define AVX_SCALAR(instr, prefix, escape, opcode)                      \
@@ -1261,6 +1273,9 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   void vcvtss2sd(XMMRegister dst, XMMRegister src1, Operand src2) {
     vinstr(0x5a, dst, src1, src2, kF3, k0F, kWIG);
   }
+  void vcvttps2dq(XMMRegister dst, XMMRegister src) {
+    vinstr(0x5b, dst, xmm0, src, kF3, k0F, kWIG);
+  }
   void vcvtlsi2sd(XMMRegister dst, XMMRegister src1, Register src2) {
     XMMRegister isrc2 = XMMRegister::from_code(src2.code());
     vinstr(0x2a, dst, src1, isrc2, kF2, k0F, kW0);
@@ -1508,6 +1523,10 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     vinstr(0x70, dst, xmm0, src, k66, k0F, kWIG);
     emit(imm8);
   }
+  void vpshufd(XMMRegister dst, Operand src, uint8_t imm8) {
+    vinstr(0x70, dst, xmm0, src, k66, k0F, kWIG);
+    emit(imm8);
+  }
   void vpshuflw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
     vinstr(0x70, dst, xmm0, src, kF2, k0F, kWIG);
     emit(imm8);
@@ -1516,6 +1535,14 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
     vinstr(0x70, dst, xmm0, src, kF2, k0F, kWIG);
     emit(imm8);
   }
+  void vpshufhw(XMMRegister dst, XMMRegister src, uint8_t imm8) {
+    vinstr(0x70, dst, xmm0, src, kF3, k0F, kWIG);
+    emit(imm8);
+  }
+  void vpshufhw(XMMRegister dst, Operand src, uint8_t imm8) {
+    vinstr(0x70, dst, xmm0, src, kF2, k0F, kWIG);
+    emit(imm8);
+  }
 
   void vpblendw(XMMRegister dst, XMMRegister src1, XMMRegister src2,
                 uint8_t mask) {
diff --git a/deps/v8/src/codegen/x64/macro-assembler-x64.cc b/deps/v8/src/codegen/x64/macro-assembler-x64.cc
index 60b2c2b10c..a3389f1bb0 100644
--- a/deps/v8/src/codegen/x64/macro-assembler-x64.cc
+++ b/deps/v8/src/codegen/x64/macro-assembler-x64.cc
@@ -34,28 +34,18 @@
 namespace v8 {
 namespace internal {
 
-Operand StackArgumentsAccessor::GetArgumentOperand(int index) {
+Operand StackArgumentsAccessor::GetArgumentOperand(int index) const {
   DCHECK_GE(index, 0);
-  int receiver = (receiver_mode_ == ARGUMENTS_CONTAIN_RECEIVER) ? 1 : 0;
-  int displacement_to_last_argument =
-      base_reg_ == rsp ? kPCOnStackSize : kFPOnStackSize + kPCOnStackSize;
-  displacement_to_last_argument += extra_displacement_to_last_argument_;
-  if (argument_count_reg_ == no_reg) {
-    // argument[0] is at base_reg_ + displacement_to_last_argument +
-    // (argument_count_immediate_ + receiver - 1) * kSystemPointerSize.
-    DCHECK_GT(argument_count_immediate_ + receiver, 0);
-    return Operand(base_reg_,
-                   displacement_to_last_argument +
-                       (argument_count_immediate_ + receiver - 1 - index) *
-                           kSystemPointerSize);
-  } else {
-    // argument[0] is at base_reg_ + displacement_to_last_argument +
-    // argument_count_reg_ * times_system_pointer_size + (receiver - 1) *
-    // kSystemPointerSize.
-    return Operand(base_reg_, argument_count_reg_, times_system_pointer_size,
-                   displacement_to_last_argument +
-                       (receiver - 1 - index) * kSystemPointerSize);
-  }
+#ifdef V8_REVERSE_JSARGS
+  // arg[0] = rsp + kPCOnStackSize;
+  // arg[i] = arg[0] + i * kSystemPointerSize;
+  return Operand(rsp, kPCOnStackSize + index * kSystemPointerSize);
+#else
+  // arg[0] = (rsp + kPCOnStackSize) + argc * kSystemPointerSize;
+  // arg[i] = arg[0] - i * kSystemPointerSize;
+  return Operand(rsp, argc_, times_system_pointer_size,
+                 kPCOnStackSize - index * kSystemPointerSize);
+#endif
 }
 
 void MacroAssembler::Load(Register destination, ExternalReference source) {
@@ -1411,6 +1401,31 @@ void TurboAssembler::Push(Handle<HeapObject> source) {
   Push(kScratchRegister);
 }
 
+void TurboAssembler::PushArray(Register array, Register size, Register scratch,
+                               PushArrayOrder order) {
+  DCHECK(!AreAliased(array, size, scratch));
+  Register counter = scratch;
+  Label loop, entry;
+  if (order == PushArrayOrder::kReverse) {
+    Set(counter, 0);
+    jmp(&entry);
+    bind(&loop);
+    Push(Operand(array, counter, times_system_pointer_size, 0));
+    incq(counter);
+    bind(&entry);
+    cmpq(counter, size);
+    j(less, &loop, Label::kNear);
+  } else {
+    movq(counter, size);
+    jmp(&entry);
+    bind(&loop);
+    Push(Operand(array, counter, times_system_pointer_size, 0));
+    bind(&entry);
+    decq(counter);
+    j(greater_equal, &loop, Label::kNear);
+  }
+}
+
 void TurboAssembler::Move(Register result, Handle<HeapObject> object,
                           RelocInfo::Mode rmode) {
   // TODO(jgruber,v8:8887): Also consider a root-relative load when generating
@@ -2078,7 +2093,7 @@ void TurboAssembler::AssertZeroExtended(Register int32_register) {
     DCHECK_NE(int32_register, kScratchRegister);
     movq(kScratchRegister, int64_t{0x0000000100000000});
     cmpq(kScratchRegister, int32_register);
-    Check(above_equal, AbortReason::k32BitValueInRegisterIsNotZeroExtended);
+    Check(above, AbortReason::k32BitValueInRegisterIsNotZeroExtended);
   }
 }
 
@@ -2371,8 +2386,15 @@ void MacroAssembler::CallDebugOnFunctionCall(Register fun, Register new_target,
   }
   Push(fun);
   Push(fun);
-  Push(
-      StackArgumentsAccessor(rbp, actual_parameter_count).GetReceiverOperand());
+  // Arguments are located 2 words below the base pointer.
+#ifdef V8_REVERSE_JSARGS
+  Operand receiver_op = Operand(rbp, kSystemPointerSize * 2);
+#else
+  Operand receiver_op =
+      Operand(rbp, actual_parameter_count, times_system_pointer_size,
+              kSystemPointerSize * 2);
+#endif
+  Push(receiver_op);
   CallRuntime(Runtime::kDebugOnFunctionCall);
   Pop(fun);
   if (new_target.is_valid()) {
@@ -2651,23 +2673,57 @@ void TurboAssembler::CallCFunction(Register function, int num_arguments) {
 
   // Save the frame pointer and PC so that the stack layout remains iterable,
   // even without an ExitFrame which normally exists between JS and C frames.
-  if (isolate() != nullptr) {
-    Label get_pc;
-    DCHECK(!AreAliased(kScratchRegister, function));
-    leaq(kScratchRegister, Operand(&get_pc, 0));
-    bind(&get_pc);
+  Label get_pc;
+  DCHECK(!AreAliased(kScratchRegister, function));
+  leaq(kScratchRegister, Operand(&get_pc, 0));
+  bind(&get_pc);
+
+  // Addressing the following external references is tricky because we need
+  // this to work in three situations:
+  // 1. In wasm compilation, the isolate is nullptr and thus no
+  //    ExternalReference can be created, but we can construct the address
+  //    directly using the root register and a static offset.
+  // 2. In normal JIT (and builtin) compilation, the external reference is
+  //    usually addressed through the root register, so we can use the direct
+  //    offset directly in most cases.
+  // 3. In regexp compilation, the external reference is embedded into the reloc
+  //    info.
+  // The solution here is to use root register offsets wherever possible in
+  // which case we can construct it directly. When falling back to external
+  // references we need to ensure that the scratch register does not get
+  // accidentally overwritten. If we run into more such cases in the future, we
+  // should implement a more general solution.
+  if (root_array_available()) {
+    movq(Operand(kRootRegister, IsolateData::fast_c_call_caller_pc_offset()),
+         kScratchRegister);
+    movq(Operand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()),
+         rbp);
+  } else {
+    DCHECK_NOT_NULL(isolate());
+    // Use alternative scratch register in order not to overwrite
+    // kScratchRegister.
+    Register scratch = r12;
+    pushq(scratch);
+
     movq(ExternalReferenceAsOperand(
-             ExternalReference::fast_c_call_caller_pc_address(isolate())),
+             ExternalReference::fast_c_call_caller_pc_address(isolate()),
+             scratch),
          kScratchRegister);
     movq(ExternalReferenceAsOperand(
              ExternalReference::fast_c_call_caller_fp_address(isolate())),
          rbp);
+
+    popq(scratch);
   }
 
   call(function);
 
-  if (isolate() != nullptr) {
-    // We don't unset the PC; the FP is the source of truth.
+  // We don't unset the PC; the FP is the source of truth.
+  if (root_array_available()) {
+    movq(Operand(kRootRegister, IsolateData::fast_c_call_caller_fp_offset()),
+         Immediate(0));
+  } else {
+    DCHECK_NOT_NULL(isolate());
     movq(ExternalReferenceAsOperand(
              ExternalReference::fast_c_call_caller_fp_address(isolate())),
          Immediate(0));
@@ -2712,7 +2768,9 @@ void TurboAssembler::ResetSpeculationPoisonRegister() {
   Set(kSpeculationPoisonRegister, -1);
 }
 
-void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
+void TurboAssembler::CallForDeoptimization(Address target, int deopt_id,
+                                           Label* exit, DeoptimizeKind kind) {
+  USE(exit, kind);
   NoRootArrayScope no_root_array(this);
   // Save the deopt id in r13 (we don't need the roots array from now on).
   movq(r13, Immediate(deopt_id));
@@ -2720,6 +2778,7 @@ void TurboAssembler::CallForDeoptimization(Address target, int deopt_id) {
 }
 
 void TurboAssembler::Trap() { int3(); }
+void TurboAssembler::DebugBreak() { int3(); }
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/codegen/x64/macro-assembler-x64.h b/deps/v8/src/codegen/x64/macro-assembler-x64.h
index 84244ea455..da9ab5da32 100644
--- a/deps/v8/src/codegen/x64/macro-assembler-x64.h
+++ b/deps/v8/src/codegen/x64/macro-assembler-x64.h
@@ -33,36 +33,22 @@ struct SmiIndex {
   ScaleFactor scale;
 };
 
-enum StackArgumentsAccessorReceiverMode {
-  ARGUMENTS_CONTAIN_RECEIVER,
-  ARGUMENTS_DONT_CONTAIN_RECEIVER
-};
-
+// Convenient class to access arguments below the stack pointer.
 class StackArgumentsAccessor {
  public:
-  StackArgumentsAccessor(Register base_reg, Register argument_count_reg,
-                         StackArgumentsAccessorReceiverMode receiver_mode =
-                             ARGUMENTS_CONTAIN_RECEIVER,
-                         int extra_displacement_to_last_argument = 0)
-      : base_reg_(base_reg),
-        argument_count_reg_(argument_count_reg),
-        argument_count_immediate_(0),
-        receiver_mode_(receiver_mode),
-        extra_displacement_to_last_argument_(
-            extra_displacement_to_last_argument) {}
-
-  Operand GetArgumentOperand(int index);
-  Operand GetReceiverOperand() {
-    DCHECK(receiver_mode_ == ARGUMENTS_CONTAIN_RECEIVER);
-    return GetArgumentOperand(0);
+  // argc = the number of arguments not including the receiver.
+  explicit StackArgumentsAccessor(Register argc) : argc_(argc) {
+    DCHECK_NE(argc_, no_reg);
   }
 
+  // Argument 0 is the receiver (despite argc not including the receiver).
+  Operand operator[](int index) const { return GetArgumentOperand(index); }
+
+  Operand GetArgumentOperand(int index) const;
+  Operand GetReceiverOperand() const { return GetArgumentOperand(0); }
+
  private:
-  const Register base_reg_;
-  const Register argument_count_reg_;
-  const int argument_count_immediate_;
-  const StackArgumentsAccessorReceiverMode receiver_mode_;
-  const int extra_displacement_to_last_argument_;
+  const Register argc_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StackArgumentsAccessor);
 };
@@ -158,7 +144,15 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_OP(Movss, movss)
   AVX_OP(Movsd, movsd)
   AVX_OP(Movdqu, movdqu)
+  AVX_OP(Pcmpeqb, pcmpeqb)
+  AVX_OP(Pcmpeqw, pcmpeqw)
   AVX_OP(Pcmpeqd, pcmpeqd)
+  AVX_OP(Pcmpgtb, pcmpgtb)
+  AVX_OP(Pcmpgtw, pcmpgtw)
+  AVX_OP(Pmaxsw, pmaxsw)
+  AVX_OP(Pmaxub, pmaxub)
+  AVX_OP(Pminsw, pminsw)
+  AVX_OP(Pminub, pminub)
   AVX_OP(Addss, addss)
   AVX_OP(Addsd, addsd)
   AVX_OP(Mulsd, mulsd)
@@ -185,22 +179,40 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_OP(Sqrtsd, sqrtsd)
   AVX_OP(Sqrtps, sqrtps)
   AVX_OP(Sqrtpd, sqrtpd)
+  AVX_OP(Cvttps2dq, cvttps2dq)
   AVX_OP(Ucomiss, ucomiss)
   AVX_OP(Ucomisd, ucomisd)
-  AVX_OP(Paddusb, paddusb)
   AVX_OP(Pand, pand)
   AVX_OP(Por, por)
   AVX_OP(Pxor, pxor)
+  AVX_OP(Psubb, psubb)
+  AVX_OP(Psubw, psubw)
   AVX_OP(Psubd, psubd)
   AVX_OP(Psubq, psubq)
+  AVX_OP(Psubsb, psubsb)
+  AVX_OP(Psubsw, psubsw)
+  AVX_OP(Psubusb, psubusb)
+  AVX_OP(Psubusw, psubusw)
   AVX_OP(Pslld, pslld)
   AVX_OP(Pavgb, pavgb)
   AVX_OP(Pavgw, pavgw)
+  AVX_OP(Psraw, psraw)
   AVX_OP(Psrad, psrad)
+  AVX_OP(Psllw, psllw)
+  AVX_OP(Psllq, psllq)
+  AVX_OP(Psrlw, psrlw)
   AVX_OP(Psrld, psrld)
+  AVX_OP(Psrlq, psrlq)
+  AVX_OP(Paddb, paddb)
+  AVX_OP(Paddw, paddw)
   AVX_OP(Paddd, paddd)
   AVX_OP(Paddq, paddq)
+  AVX_OP(Paddsb, paddsb)
+  AVX_OP(Paddsw, paddsw)
+  AVX_OP(Paddusb, paddusb)
+  AVX_OP(Paddusw, paddusw)
   AVX_OP(Pcmpgtd, pcmpgtd)
+  AVX_OP(Pmullw, pmullw)
   AVX_OP(Pmuludq, pmuludq)
   AVX_OP(Addpd, addpd)
   AVX_OP(Subpd, subpd)
@@ -220,25 +232,49 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   AVX_OP(Mulps, mulps)
   AVX_OP(Divps, divps)
   AVX_OP(Pshuflw, pshuflw)
+  AVX_OP(Pshufhw, pshufhw)
+  AVX_OP(Packsswb, packsswb)
+  AVX_OP(Packuswb, packuswb)
+  AVX_OP(Packssdw, packssdw)
+  AVX_OP(Punpcklbw, punpcklbw)
+  AVX_OP(Punpcklwd, punpcklwd)
+  AVX_OP(Punpckldq, punpckldq)
+  AVX_OP(Punpckhbw, punpckhbw)
+  AVX_OP(Punpckhwd, punpckhwd)
+  AVX_OP(Punpckhdq, punpckhdq)
   AVX_OP(Punpcklqdq, punpcklqdq)
+  AVX_OP(Punpckhqdq, punpckhqdq)
   AVX_OP(Pshufd, pshufd)
   AVX_OP(Cmpps, cmpps)
   AVX_OP(Cmppd, cmppd)
   AVX_OP(Movlhps, movlhps)
   AVX_OP_SSE3(Movddup, movddup)
+  AVX_OP_SSSE3(Phaddd, phaddd)
+  AVX_OP_SSSE3(Phaddw, phaddw)
   AVX_OP_SSSE3(Pshufb, pshufb)
+  AVX_OP_SSSE3(Psignb, psignb)
+  AVX_OP_SSSE3(Psignw, psignw)
   AVX_OP_SSSE3(Psignd, psignd)
   AVX_OP_SSSE3(Palignr, palignr)
+  AVX_OP_SSSE3(Pabsb, pabsb)
+  AVX_OP_SSSE3(Pabsw, pabsw)
+  AVX_OP_SSSE3(Pabsd, pabsd)
   AVX_OP_SSE4_1(Pcmpeqq, pcmpeqq)
-  AVX_OP_SSE4_1(Pmulld, pmulld)
+  AVX_OP_SSE4_1(Packusdw, packusdw)
+  AVX_OP_SSE4_1(Pminsb, pminsb)
   AVX_OP_SSE4_1(Pminsd, pminsd)
+  AVX_OP_SSE4_1(Pminuw, pminuw)
   AVX_OP_SSE4_1(Pminud, pminud)
+  AVX_OP_SSE4_1(Pmaxsb, pmaxsb)
   AVX_OP_SSE4_1(Pmaxsd, pmaxsd)
+  AVX_OP_SSE4_1(Pmaxuw, pmaxuw)
   AVX_OP_SSE4_1(Pmaxud, pmaxud)
+  AVX_OP_SSE4_1(Pmulld, pmulld)
   AVX_OP_SSE4_1(Extractps, extractps)
   AVX_OP_SSE4_1(Insertps, insertps)
   AVX_OP_SSE4_1(Pinsrq, pinsrq)
   AVX_OP_SSE4_1(Pblendw, pblendw)
+  AVX_OP_SSE4_1(Ptest, ptest)
   AVX_OP_SSE4_1(Pmovsxbw, pmovsxbw)
   AVX_OP_SSE4_1(Pmovsxwd, pmovsxwd)
   AVX_OP_SSE4_1(Pmovsxdq, pmovsxdq)
@@ -276,6 +312,12 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Push(Smi smi);
   void Push(Handle<HeapObject> source);
 
+  enum class PushArrayOrder { kNormal, kReverse };
+  // `array` points to the first element (the lowest address).
+  // `array` and `size` are not modified.
+  void PushArray(Register array, Register size, Register scratch,
+                 PushArrayOrder order = PushArrayOrder::kNormal);
+
   // Before calling a C-function from generated code, align arguments on stack.
   // After aligning the frame, arguments must be stored in rsp[0], rsp[8],
   // etc., not pushed. The argument count assumes all arguments are word sized.
@@ -460,9 +502,11 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void RetpolineJump(Register reg);
 
-  void CallForDeoptimization(Address target, int deopt_id);
+  void CallForDeoptimization(Address target, int deopt_id, Label* exit,
+                             DeoptimizeKind kind);
 
   void Trap() override;
+  void DebugBreak() override;
 
   // Non-SSE2 instructions.
   void Pextrd(Register dst, XMMRegister src, int8_t imm8);
@@ -475,7 +519,9 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   void Pinsrb(XMMRegister dst, Register src, int8_t imm8);
   void Pinsrb(XMMRegister dst, Operand src, int8_t imm8);
 
+  void Psllq(XMMRegister dst, int imm8) { Psllq(dst, static_cast<byte>(imm8)); }
   void Psllq(XMMRegister dst, byte imm8);
+  void Psrlq(XMMRegister dst, int imm8) { Psrlq(dst, static_cast<byte>(imm8)); }
   void Psrlq(XMMRegister dst, byte imm8);
   void Pslld(XMMRegister dst, byte imm8);
   void Psrld(XMMRegister dst, byte imm8);
@@ -586,6 +632,16 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
 
   void ResetSpeculationPoisonRegister();
 
+  // Control-flow integrity:
+
+  // Define a function entrypoint. This doesn't emit any code for this
+  // architecture, as control-flow integrity is not supported for it.
+  void CodeEntry() {}
+  // Define an exception handler.
+  void ExceptionHandler() {}
+  // Define an exception handler and bind a label.
+  void BindExceptionHandler(Label* label) { bind(label); }
+
   // ---------------------------------------------------------------------------
   // Pointer compression support
 
diff --git a/deps/v8/src/codegen/x64/sse-instr.h b/deps/v8/src/codegen/x64/sse-instr.h
index 6fba5c070c..74ec16d6a2 100644
--- a/deps/v8/src/codegen/x64/sse-instr.h
+++ b/deps/v8/src/codegen/x64/sse-instr.h
@@ -36,11 +36,12 @@
   V(maxss, F3, 0F, 5F)
 
 #define SSE2_INSTRUCTION_LIST(V) \
-  V(sqrtpd, 66, 0F, 51)          \
+  V(andpd, 66, 0F, 54)           \
   V(andnpd, 66, 0F, 55)          \
+  V(orpd, 66, 0F, 56)            \
+  V(xorpd, 66, 0F, 57)           \
   V(addpd, 66, 0F, 58)           \
   V(mulpd, 66, 0F, 59)           \
-  V(cvtps2dq, 66, 0F, 5B)        \
   V(subpd, 66, 0F, 5C)           \
   V(minpd, 66, 0F, 5D)           \
   V(maxpd, 66, 0F, 5F)           \
@@ -98,6 +99,11 @@
   V(por, 66, 0F, EB)             \
   V(pxor, 66, 0F, EF)
 
+// SSE2 instructions whose AVX version has two operands.
+#define SSE2_UNOP_INSTRUCTION_LIST(V) \
+  V(sqrtpd, 66, 0F, 51)               \
+  V(cvtps2dq, 66, 0F, 5B)
+
 // SSE2 shift instructions with an immediate operand. The last element is the
 // extension to the opcode.
 #define SSE2_INSTRUCTION_LIST_SHIFT_IMM(V) \
@@ -115,15 +121,13 @@
   V(sqrtsd, F2, 0F, 51)             \
   V(addsd, F2, 0F, 58)              \
   V(mulsd, F2, 0F, 59)              \
+  V(cvtsd2ss, F2, 0F, 5A)           \
   V(subsd, F2, 0F, 5C)              \
   V(minsd, F2, 0F, 5D)              \
   V(divsd, F2, 0F, 5E)              \
   V(maxsd, F2, 0F, 5F)
 
 #define SSSE3_INSTRUCTION_LIST(V) \
-  V(pabsb, 66, 0F, 38, 1C)        \
-  V(pabsw, 66, 0F, 38, 1D)        \
-  V(pabsd, 66, 0F, 38, 1E)        \
   V(phaddd, 66, 0F, 38, 02)       \
   V(phaddw, 66, 0F, 38, 01)       \
   V(pshufb, 66, 0F, 38, 00)       \
@@ -131,9 +135,14 @@
   V(psignw, 66, 0F, 38, 09)       \
   V(psignd, 66, 0F, 38, 0A)
 
+// SSSE3 instructions whose AVX version has two operands.
+#define SSSE3_UNOP_INSTRUCTION_LIST(V) \
+  V(pabsb, 66, 0F, 38, 1C)             \
+  V(pabsw, 66, 0F, 38, 1D)             \
+  V(pabsd, 66, 0F, 38, 1E)
+
 #define SSE4_INSTRUCTION_LIST(V) \
   V(pcmpeqq, 66, 0F, 38, 29)     \
-  V(ptest, 66, 0F, 38, 17)       \
   V(packusdw, 66, 0F, 38, 2B)    \
   V(pminsb, 66, 0F, 38, 38)      \
   V(pminsd, 66, 0F, 38, 39)      \
@@ -146,7 +155,8 @@
   V(pmulld, 66, 0F, 38, 40)
 
 // SSE instructions whose AVX version has two operands.
-#define SSE4_PMOV_INSTRUCTION_LIST(V) \
+#define SSE4_UNOP_INSTRUCTION_LIST(V) \
+  V(ptest, 66, 0F, 38, 17)            \
   V(pmovsxbw, 66, 0F, 38, 20)         \
   V(pmovsxwd, 66, 0F, 38, 23)         \
   V(pmovsxdq, 66, 0F, 38, 25)         \
diff --git a/deps/v8/src/common/globals.h b/deps/v8/src/common/globals.h
index 44441e0fc9..c79b3b633c 100644
--- a/deps/v8/src/common/globals.h
+++ b/deps/v8/src/common/globals.h
@@ -46,6 +46,9 @@ constexpr int GB = MB * 1024;
 #if (V8_TARGET_ARCH_PPC && !V8_HOST_ARCH_PPC)
 #define USE_SIMULATOR 1
 #endif
+#if (V8_TARGET_ARCH_PPC64 && !V8_HOST_ARCH_PPC64)
+#define USE_SIMULATOR 1
+#endif
 #if (V8_TARGET_ARCH_MIPS && !V8_HOST_ARCH_MIPS)
 #define USE_SIMULATOR 1
 #endif
@@ -59,7 +62,7 @@ constexpr int GB = MB * 1024;
 
 // Determine whether the architecture uses an embedded constant pool
 // (contiguous constant pool embedded in code object).
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #define V8_EMBEDDED_CONSTANT_POOL true
 #else
 #define V8_EMBEDDED_CONSTANT_POOL false
@@ -191,8 +194,9 @@ constexpr size_t kMaxWasmCodeSpaceSize = kMaxWasmCodeMemory;
 constexpr int kSystemPointerSizeLog2 = 3;
 constexpr intptr_t kIntptrSignBit =
     static_cast<intptr_t>(uintptr_t{0x8000000000000000});
-constexpr bool kRequiresCodeRange = true;
-#if V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
+constexpr bool kPlatformRequiresCodeRange = true;
+#if (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) && \
+    (V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64) && V8_OS_LINUX
 constexpr size_t kMaximalCodeRangeSize = 512 * MB;
 constexpr size_t kMinExpectedOSPageSize = 64 * KB;  // OS page on PPC Linux
 #elif V8_TARGET_ARCH_ARM64
@@ -212,18 +216,19 @@ constexpr size_t kReservedCodeRangePages = 0;
 #else
 constexpr int kSystemPointerSizeLog2 = 2;
 constexpr intptr_t kIntptrSignBit = 0x80000000;
-#if V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
-constexpr bool kRequiresCodeRange = false;
+#if (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) && \
+    (V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64) && V8_OS_LINUX
+constexpr bool kPlatformRequiresCodeRange = false;
 constexpr size_t kMaximalCodeRangeSize = 0 * MB;
 constexpr size_t kMinimumCodeRangeSize = 0 * MB;
 constexpr size_t kMinExpectedOSPageSize = 64 * KB;  // OS page on PPC Linux
 #elif V8_TARGET_ARCH_MIPS
-constexpr bool kRequiresCodeRange = false;
+constexpr bool kPlatformRequiresCodeRange = false;
 constexpr size_t kMaximalCodeRangeSize = 2048LL * MB;
 constexpr size_t kMinimumCodeRangeSize = 0 * MB;
 constexpr size_t kMinExpectedOSPageSize = 4 * KB;  // OS page.
 #else
-constexpr bool kRequiresCodeRange = false;
+constexpr bool kPlatformRequiresCodeRange = false;
 constexpr size_t kMaximalCodeRangeSize = 0 * MB;
 constexpr size_t kMinimumCodeRangeSize = 0 * MB;
 constexpr size_t kMinExpectedOSPageSize = 4 * KB;  // OS page.
@@ -342,7 +347,7 @@ F FUNCTION_CAST(Address addr) {
 // Determine whether the architecture uses function descriptors
 // which provide a level of indirection between the function pointer
 // and the function entrypoint.
-#if V8_HOST_ARCH_PPC &&                                            \
+#if (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64) &&                    \
     (V8_OS_AIX || (V8_TARGET_ARCH_PPC64 && V8_TARGET_BIG_ENDIAN && \
                    (!defined(_CALL_ELF) || _CALL_ELF == 1)))
 #define USES_FUNCTION_DESCRIPTORS 1
@@ -418,6 +423,10 @@ enum ArgvMode { kArgvOnStack, kArgvInRegister };
 // This constant is used as an undefined value when passing source positions.
 constexpr int kNoSourcePosition = -1;
 
+// This constant is used to signal the function entry implicit stack check
+// bytecode offset.
+constexpr int kFunctionEntryBytecodeOffset = -1;
+
 // This constant is used to indicate missing deoptimization information.
 constexpr int kNoDeoptimizationId = -1;
 
@@ -577,11 +586,19 @@ enum class HeapObjectReferenceType {
   STRONG,
 };
 
+enum class ArgumentsType {
+  kRuntime,
+  kJS,
+};
+
 // -----------------------------------------------------------------------------
 // Forward declarations for frequently used classes
 
 class AccessorInfo;
+template <ArgumentsType>
 class Arguments;
+using RuntimeArguments = Arguments<ArgumentsType::kRuntime>;
+using JavaScriptArguments = Arguments<ArgumentsType::kJS>;
 class Assembler;
 class ClassScope;
 class Code;
@@ -811,6 +828,10 @@ enum class REPLMode {
   kNo,
 };
 
+inline REPLMode construct_repl_mode(bool is_repl_mode) {
+  return is_repl_mode ? REPLMode::kYes : REPLMode::kNo;
+}
+
 // Flag indicating whether code is built into the VM (one of the natives files).
 enum NativesFlag { NOT_NATIVES_CODE, EXTENSION_CODE, INSPECTOR_CODE };
 
@@ -1575,7 +1596,9 @@ enum class LoadSensitivity {
   V(TrapFuncSigMismatch)           \
   V(TrapDataSegmentDropped)        \
   V(TrapElemSegmentDropped)        \
-  V(TrapTableOutOfBounds)
+  V(TrapTableOutOfBounds)          \
+  V(TrapBrOnExnNullRef)            \
+  V(TrapRethrowNullRef)
 
 enum KeyedAccessLoadMode {
   STANDARD_LOAD,
@@ -1622,6 +1645,8 @@ constexpr int kFunctionLiteralIdTopLevel = 0;
 constexpr int kSmallOrderedHashSetMinCapacity = 4;
 constexpr int kSmallOrderedHashMapMinCapacity = 4;
 
+static const uint16_t kDontAdaptArgumentsSentinel = static_cast<uint16_t>(-1);
+
 // Opaque data type for identifying stack frames. Used extensively
 // by the debugger.
 // ID_MIN_VALUE and ID_MAX_VALUE are specified to ensure that enumeration type
diff --git a/deps/v8/src/common/message-template.h b/deps/v8/src/common/message-template.h
index 8c10c42b7b..13d5310d92 100644
--- a/deps/v8/src/common/message-template.h
+++ b/deps/v8/src/common/message-template.h
@@ -415,6 +415,7 @@ namespace internal {
     "Invalid left-hand side expression in prefix operation")                   \
   T(InvalidRegExpFlags, "Invalid flags supplied to RegExp constructor '%'")    \
   T(InvalidOrUnexpectedToken, "Invalid or unexpected token")                   \
+  T(InvalidPrivateBrand, "Object must be an instance of class %")              \
   T(InvalidPrivateFieldResolution,                                             \
     "Private field '%' must be declared in an enclosing class")                \
   T(InvalidPrivateMemberRead,                                                  \
@@ -426,6 +427,8 @@ namespace internal {
   T(InvalidPrivateMethodWrite, "Private method '%' is not writable")           \
   T(InvalidPrivateGetterAccess, "'%' was defined without a getter")            \
   T(InvalidPrivateSetterAccess, "'%' was defined without a setter")            \
+  T(InvalidUnusedPrivateStaticMethodAccessedByDebugger,                        \
+    "Unused static private method '%' cannot be accessed at debug time")       \
   T(JsonParseUnexpectedEOS, "Unexpected end of JSON input")                    \
   T(JsonParseUnexpectedToken, "Unexpected token % in JSON at position %")      \
   T(JsonParseUnexpectedTokenNumber, "Unexpected number in JSON at position %") \
@@ -549,6 +552,8 @@ namespace internal {
   T(WasmTrapDataSegmentDropped, "data segment has been dropped")               \
   T(WasmTrapElemSegmentDropped, "element segment has been dropped")            \
   T(WasmTrapTableOutOfBounds, "table access out of bounds")                    \
+  T(WasmTrapBrOnExnNullRef, "br_on_exn on nullref value")                      \
+  T(WasmTrapRethrowNullRef, "rethrowing nullref value")                        \
   T(WasmExceptionError, "wasm exception")                                      \
   /* Asm.js validation related */                                              \
   T(AsmJsInvalid, "Invalid asm.js: %")                                         \
@@ -578,12 +583,12 @@ namespace internal {
   T(WeakRefsUnregisterTokenMustBeObject,                                       \
     "unregisterToken ('%') must be an object")                                 \
   T(WeakRefsCleanupMustBeCallable,                                             \
-    "FinalizationGroup: cleanup must be callable")                             \
+    "FinalizationRegistry: cleanup must be callable")                          \
   T(WeakRefsRegisterTargetMustBeObject,                                        \
-    "FinalizationGroup.prototype.register: target must be an object")          \
+    "FinalizationRegistry.prototype.register: target must be an object")       \
   T(WeakRefsRegisterTargetAndHoldingsMustNotBeSame,                            \
-    "FinalizationGroup.prototype.register: target and holdings must not be "   \
-    "same")                                                                    \
+    "FinalizationRegistry.prototype.register: target and holdings must not "   \
+    "be same")                                                                 \
   T(WeakRefsWeakRefConstructorTargetMustBeObject,                              \
     "WeakRef: target must be an object")                                       \
   T(OptionalChainingNoNew, "Invalid optional chain from new expression")       \
diff --git a/deps/v8/src/compiler/backend/arm/code-generator-arm.cc b/deps/v8/src/compiler/backend/arm/code-generator-arm.cc
index a82eb4b35c..5b0c74799b 100644
--- a/deps/v8/src/compiler/backend/arm/code-generator-arm.cc
+++ b/deps/v8/src/compiler/backend/arm/code-generator-arm.cc
@@ -507,6 +507,45 @@ void ComputePoisonedAddressForLoad(CodeGenerator* codegen,
           i.InputSimd128Register(1).high());                                  \
   } while (0)
 
+// If shift value is an immediate, we can call asm_imm, taking the shift value
+// modulo 2^width. Otherwise, emit code to perform the modulus operation, and
+// call vshl.
+#define ASSEMBLE_SIMD_SHIFT_LEFT(asm_imm, width, sz, dt) \
+  do {                                                   \
+    QwNeonRegister dst = i.OutputSimd128Register();      \
+    QwNeonRegister src = i.InputSimd128Register(0);      \
+    if (instr->InputAt(1)->IsImmediate()) {              \
+      __ asm_imm(dt, dst, src, i.InputInt##width(1));    \
+    } else {                                             \
+      QwNeonRegister tmp = i.TempSimd128Register(0);     \
+      Register shift = i.TempRegister(1);                \
+      constexpr int mask = (1 << width) - 1;             \
+      __ and_(shift, i.InputRegister(1), Operand(mask)); \
+      __ vdup(sz, tmp, shift);                           \
+      __ vshl(dt, dst, src, tmp);                        \
+    }                                                    \
+  } while (0)
+
+// If shift value is an immediate, we can call asm_imm, taking the shift value
+// modulo 2^width. Otherwise, emit code to perform the modulus operation, and
+// call vshl, passing in the negative shift value (treated as a right shift).
+#define ASSEMBLE_SIMD_SHIFT_RIGHT(asm_imm, width, sz, dt) \
+  do {                                                    \
+    QwNeonRegister dst = i.OutputSimd128Register();       \
+    QwNeonRegister src = i.InputSimd128Register(0);       \
+    if (instr->InputAt(1)->IsImmediate()) {               \
+      __ asm_imm(dt, dst, src, i.InputInt##width(1));     \
+    } else {                                              \
+      QwNeonRegister tmp = i.TempSimd128Register(0);      \
+      Register shift = i.TempRegister(1);                 \
+      constexpr int mask = (1 << width) - 1;              \
+      __ and_(shift, i.InputRegister(1), Operand(mask));  \
+      __ vdup(sz, tmp, shift);                            \
+      __ vneg(sz, tmp, tmp);                              \
+      __ vshl(dt, dst, src, tmp);                         \
+    }                                                     \
+  } while (0)
+
 void CodeGenerator::AssembleDeconstructFrame() {
   __ LeaveFrame(StackFrame::MANUAL);
   unwinding_info_writer_.MarkFrameDeconstructed(__ pc_offset());
@@ -890,10 +929,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      DCHECK_EQ(LeaveCC, i.OutputSBit());
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       DCHECK_EQ(LeaveCC, i.OutputSBit());
@@ -912,7 +947,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       unwinding_info_writer_.MarkBlockWillExit();
       break;
     case kArchDebugBreak:
-      __ stop();
+      __ DebugBreak();
       break;
     case kArchComment:
       __ RecordComment(reinterpret_cast<const char*>(i.InputInt32(0)));
@@ -2039,38 +2074,19 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI64x2Shl: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ and_(shift, i.InputRegister(1), Operand(63));
-      // Only the least significant byte of each lane is used.
-      __ vdup(Neon32, tmp, shift);
-      __ vshl(NeonS64, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_LEFT(vshl, 6, Neon32, NeonS64);
       break;
     }
     case kArmI64x2ShrS: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ and_(shift, i.InputRegister(1), Operand(63));
-      // Only the least significant byte of each lane is used.
-      __ vdup(Neon32, tmp, shift);
-      __ vneg(Neon32, tmp, tmp);
-      __ vshl(NeonS64, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      // Only the least significant byte of each lane is used, so we can use
+      // Neon32 as the size.
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 6, Neon32, NeonS64);
       break;
     }
     case kArmI64x2ShrU: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ and_(shift, i.InputRegister(1), Operand(63));
-      // Only the least significant byte of each lane is used.
-      __ vdup(Neon32, tmp, shift);
-      __ vneg(Neon32, tmp, tmp);
-      __ vshl(NeonU64, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      // Only the least significant byte of each lane is used, so we can use
+      // Neon32 as the size.
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 6, Neon32, NeonU64);
       break;
     }
     case kArmF32x4Splat: {
@@ -2238,24 +2254,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI32x4Shl: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, i.InputRegister(1), Operand(31));
-      __ vdup(Neon32, tmp, shift);
-      __ vshl(NeonS32, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_LEFT(vshl, 5, Neon32, NeonS32);
       break;
     }
     case kArmI32x4ShrS: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, i.InputRegister(1), Operand(31));
-      __ vdup(Neon32, tmp, shift);
-      __ vneg(Neon32, tmp, tmp);
-      __ vshl(NeonS32, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 5, Neon32, NeonS32);
       break;
     }
     case kArmI32x4Add: {
@@ -2323,14 +2326,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI32x4ShrU: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, i.InputRegister(1), Operand(31));
-      __ vdup(Neon32, tmp, shift);
-      __ vneg(Neon32, tmp, tmp);
-      __ vshl(NeonU32, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 5, Neon32, NeonU32);
       break;
     }
     case kArmI32x4MinU: {
@@ -2353,6 +2349,27 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
               i.InputSimd128Register(1));
       break;
     }
+    case kArmI32x4Abs: {
+      __ vabs(Neon32, i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kArmI32x4BitMask: {
+      Register dst = i.OutputRegister();
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register tmp2 = i.TempSimd128Register(0);
+      Simd128Register mask = i.TempSimd128Register(1);
+
+      __ vshr(NeonS32, tmp2, src, 31);
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ vmov(mask.low(), Double((uint64_t)0x0000'0002'0000'0001));
+      __ vmov(mask.high(), Double((uint64_t)0x0000'0008'0000'0004));
+      __ vand(tmp2, mask, tmp2);
+      __ vpadd(Neon32, tmp2.low(), tmp2.low(), tmp2.high());
+      __ vpadd(Neon32, tmp2.low(), tmp2.low(), kDoubleRegZero);
+      __ VmovLow(dst, tmp2.low());
+      break;
+    }
     case kArmI16x8Splat: {
       __ vdup(Neon16, i.OutputSimd128Register(), i.InputRegister(0));
       break;
@@ -2387,24 +2404,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI16x8Shl: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, i.InputRegister(1), Operand(15));
-      __ vdup(Neon16, tmp, shift);
-      __ vshl(NeonS16, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_LEFT(vshl, 4, Neon16, NeonS16);
       break;
     }
     case kArmI16x8ShrS: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, i.InputRegister(1), Operand(15));
-      __ vdup(Neon16, tmp, shift);
-      __ vneg(Neon16, tmp, tmp);
-      __ vshl(NeonS16, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 4, Neon16, NeonS16);
       break;
     }
     case kArmI16x8SConvertI32x4:
@@ -2481,14 +2485,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI16x8ShrU: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, i.InputRegister(1), Operand(15));
-      __ vdup(Neon16, tmp, shift);
-      __ vneg(Neon16, tmp, tmp);
-      __ vshl(NeonU16, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 4, Neon16, NeonU16);
       break;
     }
     case kArmI16x8UConvertI32x4:
@@ -2529,6 +2526,28 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                 i.InputSimd128Register(1));
       break;
     }
+    case kArmI16x8Abs: {
+      __ vabs(Neon16, i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kArmI16x8BitMask: {
+      Register dst = i.OutputRegister();
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register tmp2 = i.TempSimd128Register(0);
+      Simd128Register mask = i.TempSimd128Register(1);
+
+      __ vshr(NeonS16, tmp2, src, 15);
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ vmov(mask.low(), Double((uint64_t)0x0008'0004'0002'0001));
+      __ vmov(mask.high(), Double((uint64_t)0x0080'0040'0020'0010));
+      __ vand(tmp2, mask, tmp2);
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.high());
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.low());
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.low());
+      __ vmov(NeonU16, dst, tmp2.low(), 0);
+      break;
+    }
     case kArmI8x16Splat: {
       __ vdup(Neon8, i.OutputSimd128Register(), i.InputRegister(0));
       break;
@@ -2553,24 +2572,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI8x16Shl: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 8.
-      __ and_(shift, i.InputRegister(1), Operand(7));
-      __ vdup(Neon8, tmp, i.InputRegister(1));
-      __ vshl(NeonS8, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_LEFT(vshl, 3, Neon8, NeonS8);
       break;
     }
     case kArmI8x16ShrS: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 8.
-      __ and_(shift, i.InputRegister(1), Operand(7));
-      __ vdup(Neon8, tmp, shift);
-      __ vneg(Neon8, tmp, tmp);
-      __ vshl(NeonS8, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 3, Neon8, NeonS8);
       break;
     }
     case kArmI8x16SConvertI16x8:
@@ -2633,14 +2639,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArmI8x16ShrU: {
-      QwNeonRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 8.
-      __ and_(shift, i.InputRegister(1), Operand(7));
-      __ vdup(Neon8, tmp, shift);
-      __ vneg(Neon8, tmp, tmp);
-      __ vshl(NeonU8, i.OutputSimd128Register(), i.InputSimd128Register(0),
-              tmp);
+      ASSEMBLE_SIMD_SHIFT_RIGHT(vshr, 3, Neon8, NeonU8);
       break;
     }
     case kArmI8x16UConvertI16x8:
@@ -2681,6 +2680,30 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                 i.InputSimd128Register(1));
       break;
     }
+    case kArmI8x16Abs: {
+      __ vabs(Neon8, i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
+    case kArmI8x16BitMask: {
+      Register dst = i.OutputRegister();
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register tmp2 = i.TempSimd128Register(0);
+      Simd128Register mask = i.TempSimd128Register(1);
+
+      __ vshr(NeonS8, tmp2, src, 7);
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ vmov(mask.low(), Double((uint64_t)0x8040'2010'0804'0201));
+      __ vmov(mask.high(), Double((uint64_t)0x8040'2010'0804'0201));
+      __ vand(tmp2, mask, tmp2);
+      __ vext(mask, tmp2, tmp2, 8);
+      __ vzip(Neon8, mask, tmp2);
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.high());
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.low());
+      __ vpadd(Neon16, tmp2.low(), tmp2.low(), tmp2.low());
+      __ vmov(NeonU16, dst, tmp2.low(), 0);
+      break;
+    }
     case kArmS128Zero: {
       __ veor(i.OutputSimd128Register(), i.OutputSimd128Register(),
               i.OutputSimd128Register());
@@ -3335,6 +3358,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #undef ASSEMBLE_IEEE754_UNOP
 #undef ASSEMBLE_NEON_NARROWING_OP
 #undef ASSEMBLE_NEON_PAIRWISE_OP
+#undef ASSEMBLE_SIMD_SHIFT_LEFT
+#undef ASSEMBLE_SIMD_SHIFT_RIGHT
   }
   return kSuccess;
 }  // NOLINT(readability/fn_size)
@@ -3451,16 +3476,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  ArmOperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ cmp(input, Operand(i.InputInt32(index + 0)));
-    __ b(eq, GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   ArmOperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -3524,7 +3539,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ Push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
diff --git a/deps/v8/src/compiler/backend/arm/instruction-codes-arm.h b/deps/v8/src/compiler/backend/arm/instruction-codes-arm.h
index 8173d32833..c6365bf7a5 100644
--- a/deps/v8/src/compiler/backend/arm/instruction-codes-arm.h
+++ b/deps/v8/src/compiler/backend/arm/instruction-codes-arm.h
@@ -201,6 +201,8 @@ namespace compiler {
   V(ArmI32x4MaxU)                  \
   V(ArmI32x4GtU)                   \
   V(ArmI32x4GeU)                   \
+  V(ArmI32x4Abs)                   \
+  V(ArmI32x4BitMask)               \
   V(ArmI16x8Splat)                 \
   V(ArmI16x8ExtractLaneS)          \
   V(ArmI16x8ReplaceLane)           \
@@ -234,6 +236,8 @@ namespace compiler {
   V(ArmI16x8GtU)                   \
   V(ArmI16x8GeU)                   \
   V(ArmI16x8RoundingAverageU)      \
+  V(ArmI16x8Abs)                   \
+  V(ArmI16x8BitMask)               \
   V(ArmI8x16Splat)                 \
   V(ArmI8x16ExtractLaneS)          \
   V(ArmI8x16ReplaceLane)           \
@@ -262,6 +266,8 @@ namespace compiler {
   V(ArmI8x16GtU)                   \
   V(ArmI8x16GeU)                   \
   V(ArmI8x16RoundingAverageU)      \
+  V(ArmI8x16Abs)                   \
+  V(ArmI8x16BitMask)               \
   V(ArmS128Zero)                   \
   V(ArmS128Dup)                    \
   V(ArmS128And)                    \
diff --git a/deps/v8/src/compiler/backend/arm/instruction-scheduler-arm.cc b/deps/v8/src/compiler/backend/arm/instruction-scheduler-arm.cc
index 4c0be32d8a..8c09acd6df 100644
--- a/deps/v8/src/compiler/backend/arm/instruction-scheduler-arm.cc
+++ b/deps/v8/src/compiler/backend/arm/instruction-scheduler-arm.cc
@@ -181,6 +181,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArmI32x4MaxU:
     case kArmI32x4GtU:
     case kArmI32x4GeU:
+    case kArmI32x4Abs:
+    case kArmI32x4BitMask:
     case kArmI16x8Splat:
     case kArmI16x8ExtractLaneS:
     case kArmI16x8ReplaceLane:
@@ -214,6 +216,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArmI16x8GtU:
     case kArmI16x8GeU:
     case kArmI16x8RoundingAverageU:
+    case kArmI16x8Abs:
+    case kArmI16x8BitMask:
     case kArmI8x16Splat:
     case kArmI8x16ExtractLaneS:
     case kArmI8x16ReplaceLane:
@@ -242,6 +246,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArmI8x16GtU:
     case kArmI8x16GeU:
     case kArmI8x16RoundingAverageU:
+    case kArmI8x16Abs:
+    case kArmI8x16BitMask:
     case kArmS128Zero:
     case kArmS128Dup:
     case kArmS128And:
diff --git a/deps/v8/src/compiler/backend/arm/instruction-selector-arm.cc b/deps/v8/src/compiler/backend/arm/instruction-selector-arm.cc
index 0027c7a570..38a4dd8db4 100644
--- a/deps/v8/src/compiler/backend/arm/instruction-selector-arm.cc
+++ b/deps/v8/src/compiler/backend/arm/instruction-selector-arm.cc
@@ -92,12 +92,23 @@ void VisitRRR(InstructionSelector* selector, ArchOpcode opcode, Node* node) {
 }
 
 void VisitSimdShiftRRR(InstructionSelector* selector, ArchOpcode opcode,
-                       Node* node) {
+                       Node* node, int width) {
   ArmOperandGenerator g(selector);
-  InstructionOperand temps[] = {g.TempSimd128Register(), g.TempRegister()};
-  selector->Emit(opcode, g.DefineAsRegister(node),
-                 g.UseRegister(node->InputAt(0)),
-                 g.UseRegister(node->InputAt(1)), arraysize(temps), temps);
+  Int32Matcher m(node->InputAt(1));
+  if (m.HasValue()) {
+    if (m.IsMultipleOf(width)) {
+      selector->EmitIdentity(node);
+    } else {
+      selector->Emit(opcode, g.DefineAsRegister(node),
+                     g.UseRegister(node->InputAt(0)),
+                     g.UseImmediate(node->InputAt(1)));
+    }
+  } else {
+    InstructionOperand temps[] = {g.TempSimd128Register(), g.TempRegister()};
+    selector->Emit(opcode, g.DefineAsRegister(node),
+                   g.UseUniqueRegister(node->InputAt(0)),
+                   g.UseRegister(node->InputAt(1)), arraysize(temps), temps);
+  }
 }
 
 void VisitRRRShuffle(InstructionSelector* selector, ArchOpcode opcode,
@@ -2004,7 +2015,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   ArmOperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -2458,24 +2469,24 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
                          AddressingModeField::encode(addressing_mode);
   Node* projection0 = NodeProperties::FindProjection(node, 0);
   Node* projection1 = NodeProperties::FindProjection(node, 1);
+  InstructionOperand outputs[2];
+  size_t output_count = 0;
+  InstructionOperand temps[4];
+  size_t temp_count = 0;
+  temps[temp_count++] = g.TempRegister();
+  temps[temp_count++] = g.TempRegister();
+  if (projection0) {
+    outputs[output_count++] = g.DefineAsFixed(projection0, r2);
+  } else {
+    temps[temp_count++] = g.TempRegister(r2);
+  }
   if (projection1) {
-    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, r2),
-                                    g.DefineAsFixed(projection1, r3)};
-    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister()};
-    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-         arraysize(temps), temps);
-  } else if (projection0) {
-    InstructionOperand outputs[] = {
-        g.DefineAsFixed(NodeProperties::FindProjection(node, 0), r2)};
-    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
-                                  g.TempRegister(r3)};
-    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-         arraysize(temps), temps);
+    outputs[output_count++] = g.DefineAsFixed(projection1, r3);
   } else {
-    InstructionOperand temps[] = {g.TempRegister(), g.TempRegister(),
-                                  g.TempRegister(r2), g.TempRegister(r3)};
-    Emit(code, 0, nullptr, arraysize(inputs), inputs, arraysize(temps), temps);
+    temps[temp_count++] = g.TempRegister(r3);
   }
+  Emit(code, output_count, outputs, arraysize(inputs), inputs, temp_count,
+       temps);
 }
 
 #define SIMD_TYPE_LIST(V) \
@@ -2501,12 +2512,15 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   V(I32x4UConvertF32x4, kArmI32x4UConvertF32x4)         \
   V(I32x4UConvertI16x8Low, kArmI32x4UConvertI16x8Low)   \
   V(I32x4UConvertI16x8High, kArmI32x4UConvertI16x8High) \
+  V(I32x4Abs, kArmI32x4Abs)                             \
   V(I16x8SConvertI8x16Low, kArmI16x8SConvertI8x16Low)   \
   V(I16x8SConvertI8x16High, kArmI16x8SConvertI8x16High) \
   V(I16x8Neg, kArmI16x8Neg)                             \
   V(I16x8UConvertI8x16Low, kArmI16x8UConvertI8x16Low)   \
   V(I16x8UConvertI8x16High, kArmI16x8UConvertI8x16High) \
+  V(I16x8Abs, kArmI16x8Abs)                             \
   V(I8x16Neg, kArmI8x16Neg)                             \
+  V(I8x16Abs, kArmI8x16Abs)                             \
   V(S128Not, kArmS128Not)                               \
   V(S1x4AnyTrue, kArmS1x4AnyTrue)                       \
   V(S1x4AllTrue, kArmS1x4AllTrue)                       \
@@ -2516,18 +2530,18 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   V(S1x16AllTrue, kArmS1x16AllTrue)
 
 #define SIMD_SHIFT_OP_LIST(V) \
-  V(I64x2Shl)                 \
-  V(I64x2ShrS)                \
-  V(I64x2ShrU)                \
-  V(I32x4Shl)                 \
-  V(I32x4ShrS)                \
-  V(I32x4ShrU)                \
-  V(I16x8Shl)                 \
-  V(I16x8ShrS)                \
-  V(I16x8ShrU)                \
-  V(I8x16Shl)                 \
-  V(I8x16ShrS)                \
-  V(I8x16ShrU)
+  V(I64x2Shl, 64)             \
+  V(I64x2ShrS, 64)            \
+  V(I64x2ShrU, 64)            \
+  V(I32x4Shl, 32)             \
+  V(I32x4ShrS, 32)            \
+  V(I32x4ShrU, 32)            \
+  V(I16x8Shl, 16)             \
+  V(I16x8ShrS, 16)            \
+  V(I16x8ShrU, 16)            \
+  V(I8x16Shl, 8)              \
+  V(I8x16ShrS, 8)             \
+  V(I8x16ShrU, 8)
 
 #define SIMD_BINOP_LIST(V)                            \
   V(F64x2Add, kArmF64x2Add)                           \
@@ -2655,9 +2669,9 @@ SIMD_UNOP_LIST(SIMD_VISIT_UNOP)
 #undef SIMD_VISIT_UNOP
 #undef SIMD_UNOP_LIST
 
-#define SIMD_VISIT_SHIFT_OP(Name)                     \
+#define SIMD_VISIT_SHIFT_OP(Name, width)              \
   void InstructionSelector::Visit##Name(Node* node) { \
-    VisitSimdShiftRRR(this, kArm##Name, node);        \
+    VisitSimdShiftRRR(this, kArm##Name, node, width); \
   }
 SIMD_SHIFT_OP_LIST(SIMD_VISIT_SHIFT_OP)
 #undef SIMD_VISIT_SHIFT_OP
@@ -2901,6 +2915,29 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   UNREACHABLE();
 }
 
+namespace {
+template <ArchOpcode opcode>
+void VisitBitMask(InstructionSelector* selector, Node* node) {
+  ArmOperandGenerator g(selector);
+  InstructionOperand temps[] = {g.TempSimd128Register(),
+                                g.TempSimd128Register()};
+  selector->Emit(opcode, g.DefineAsRegister(node),
+                 g.UseRegister(node->InputAt(0)), arraysize(temps), temps);
+}
+}  // namespace
+
+void InstructionSelector::VisitI8x16BitMask(Node* node) {
+  VisitBitMask<kArmI8x16BitMask>(this, node);
+}
+
+void InstructionSelector::VisitI16x8BitMask(Node* node) {
+  VisitBitMask<kArmI16x8BitMask>(this, node);
+}
+
+void InstructionSelector::VisitI32x4BitMask(Node* node) {
+  VisitBitMask<kArmI32x4BitMask>(this, node);
+}
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/deps/v8/src/compiler/backend/arm64/code-generator-arm64.cc b/deps/v8/src/compiler/backend/arm64/code-generator-arm64.cc
index 7ab1ce07d5..f01181e955 100644
--- a/deps/v8/src/compiler/backend/arm64/code-generator-arm64.cc
+++ b/deps/v8/src/compiler/backend/arm64/code-generator-arm64.cc
@@ -291,7 +291,7 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
         frame()->DidAllocateDoubleRegisters() ? kSaveFPRegs : kDontSaveFPRegs;
     if (must_save_lr_) {
       // We need to save and restore lr if the frame was elided.
-      __ Push(lr, padreg);
+      __ Push<TurboAssembler::kSignLR>(lr, padreg);
       unwinding_info_writer_->MarkLinkRegisterOnTopOfStack(__ pc_offset(), sp);
     }
     if (mode_ == RecordWriteMode::kValueIsEphemeronKey) {
@@ -307,7 +307,7 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
                              save_fp_mode);
     }
     if (must_save_lr_) {
-      __ Pop(padreg, lr);
+      __ Pop<TurboAssembler::kAuthLR>(padreg, lr);
       unwinding_info_writer_->MarkPopLinkRegisterFromTopOfStack(__ pc_offset());
     }
   }
@@ -494,20 +494,55 @@ void EmitMaybePoisonedFPLoad(CodeGenerator* codegen, InstructionCode opcode,
     __ CallCFunction(ExternalReference::ieee754_##name##_function(), 0, 1); \
   } while (0)
 
+// If shift value is an immediate, we can call asm_imm, taking the shift value
+// modulo 2^width. Otherwise, emit code to perform the modulus operation, and
+// call asm_shl.
+#define ASSEMBLE_SIMD_SHIFT_LEFT(asm_imm, width, format, asm_shl, gp)       \
+  do {                                                                      \
+    if (instr->InputAt(1)->IsImmediate()) {                                 \
+      __ asm_imm(i.OutputSimd128Register().format(),                        \
+                 i.InputSimd128Register(0).format(), i.InputInt##width(1)); \
+    } else {                                                                \
+      VRegister tmp = i.TempSimd128Register(0);                             \
+      Register shift = i.TempRegister(1).gp();                              \
+      constexpr int mask = (1 << width) - 1;                                \
+      __ And(shift, i.InputRegister32(1), mask);                            \
+      __ Dup(tmp.format(), shift);                                          \
+      __ asm_shl(i.OutputSimd128Register().format(),                        \
+                 i.InputSimd128Register(0).format(), tmp.format());         \
+    }                                                                       \
+  } while (0)
+
+// If shift value is an immediate, we can call asm_imm, taking the shift value
+// modulo 2^width. Otherwise, emit code to perform the modulus operation, and
+// call asm_shl, passing in the negative shift value (treated as right shift).
+#define ASSEMBLE_SIMD_SHIFT_RIGHT(asm_imm, width, format, asm_shl, gp)      \
+  do {                                                                      \
+    if (instr->InputAt(1)->IsImmediate()) {                                 \
+      __ asm_imm(i.OutputSimd128Register().format(),                        \
+                 i.InputSimd128Register(0).format(), i.InputInt##width(1)); \
+    } else {                                                                \
+      VRegister tmp = i.TempSimd128Register(0);                             \
+      Register shift = i.TempRegister(1).gp();                              \
+      constexpr int mask = (1 << width) - 1;                                \
+      __ And(shift, i.InputRegister32(1), mask);                            \
+      __ Dup(tmp.format(), shift);                                          \
+      __ Neg(tmp.format(), tmp.format());                                   \
+      __ asm_shl(i.OutputSimd128Register().format(),                        \
+                 i.InputSimd128Register(0).format(), tmp.format());         \
+    }                                                                       \
+  } while (0)
+
 void CodeGenerator::AssembleDeconstructFrame() {
   __ Mov(sp, fp);
-  __ Pop(fp, lr);
+  __ Pop<TurboAssembler::kAuthLR>(fp, lr);
 
   unwinding_info_writer_.MarkFrameDeconstructed(__ pc_offset());
 }
 
 void CodeGenerator::AssemblePrepareTailCall() {
   if (frame_access_state()->has_frame()) {
-    static_assert(
-        StandardFrameConstants::kCallerFPOffset + kSystemPointerSize ==
-            StandardFrameConstants::kCallerPCOffset,
-        "Offsets must be consecutive for ldp!");
-    __ Ldp(fp, lr, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+    __ RestoreFPAndLR();
   }
   frame_access_state()->SetFrameAccessToSP();
 }
@@ -779,10 +814,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Label return_location;
       if (linkage()->GetIncomingDescriptor()->IsWasmCapiFunction()) {
         // Put the return address in a stack slot.
-        Register scratch = x8;
-        __ Adr(scratch, &return_location);
-        __ Str(scratch,
-               MemOperand(fp, WasmExitFrameConstants::kCallingPCOffset));
+        __ StoreReturnAddressInWasmExitFrame(&return_location);
       }
 
       if (instr->InputAt(0)->IsImmediate()) {
@@ -824,9 +856,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      break;
     case kArchAbortCSAAssert:
       DCHECK_EQ(i.InputRegister(0), x1);
       {
@@ -841,7 +870,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       unwinding_info_writer_.MarkBlockWillExit();
       break;
     case kArchDebugBreak:
-      __ Debug("kArchDebugBreak", 0, BREAK);
+      __ DebugBreak();
       break;
     case kArchComment:
       __ RecordComment(reinterpret_cast<const char*>(i.InputInt64(0)));
@@ -894,7 +923,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     case kArchTruncateDoubleToI:
       __ TruncateDoubleToI(isolate(), zone(), i.OutputRegister(),
-                           i.InputDoubleRegister(0), DetermineStubCallMode());
+                           i.InputDoubleRegister(0), DetermineStubCallMode(),
+                           frame_access_state()->has_frame()
+                               ? kLRHasBeenSaved
+                               : kLRHasNotBeenSaved);
+
       break;
     case kArchStoreWithWriteBarrier: {
       RecordWriteMode mode =
@@ -1953,24 +1986,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
       SIMD_UNOP_CASE(kArm64I64x2Neg, Neg, 2D);
     case kArm64I64x2Shl: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ And(shift, i.InputRegister64(1), 63);
-      __ Dup(tmp.V2D(), shift);
-      __ Sshl(i.OutputSimd128Register().V2D(), i.InputSimd128Register(0).V2D(),
-              tmp.V2D());
+      ASSEMBLE_SIMD_SHIFT_LEFT(Shl, 6, V2D, Sshl, X);
       break;
     }
     case kArm64I64x2ShrS: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ And(shift, i.InputRegister64(1), 63);
-      __ Dup(tmp.V2D(), shift);
-      __ Neg(tmp.V2D(), tmp.V2D());
-      __ Sshl(i.OutputSimd128Register().V2D(), i.InputSimd128Register(0).V2D(),
-              tmp.V2D());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Sshr, 6, V2D, Sshl, X);
       break;
     }
       SIMD_BINOP_CASE(kArm64I64x2Add, Add, 2D);
@@ -2045,14 +2065,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_BINOP_CASE(kArm64I64x2GtS, Cmgt, 2D);
       SIMD_BINOP_CASE(kArm64I64x2GeS, Cmge, 2D);
     case kArm64I64x2ShrU: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister(1);
-      // Take shift value modulo 64.
-      __ And(shift, i.InputRegister64(1), 63);
-      __ Dup(tmp.V2D(), shift);
-      __ Neg(tmp.V2D(), tmp.V2D());
-      __ Ushl(i.OutputSimd128Register().V2D(), i.InputSimd128Register(0).V2D(),
-              tmp.V2D());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Ushr, 6, V2D, Ushl, X);
       break;
     }
       SIMD_BINOP_CASE(kArm64I64x2GtU, Cmhi, 2D);
@@ -2080,24 +2093,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_WIDENING_UNOP_CASE(kArm64I32x4SConvertI16x8High, Sxtl2, 4S, 8H);
       SIMD_UNOP_CASE(kArm64I32x4Neg, Neg, 4S);
     case kArm64I32x4Shl: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 32.
-      __ And(shift, i.InputRegister32(1), 31);
-      __ Dup(tmp.V4S(), shift);
-      __ Sshl(i.OutputSimd128Register().V4S(), i.InputSimd128Register(0).V4S(),
-              tmp.V4S());
+      ASSEMBLE_SIMD_SHIFT_LEFT(Shl, 5, V4S, Sshl, W);
       break;
     }
     case kArm64I32x4ShrS: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 32.
-      __ And(shift, i.InputRegister32(1), 31);
-      __ Dup(tmp.V4S(), shift);
-      __ Neg(tmp.V4S(), tmp.V4S());
-      __ Sshl(i.OutputSimd128Register().V4S(), i.InputSimd128Register(0).V4S(),
-              tmp.V4S());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Sshr, 5, V4S, Sshl, W);
       break;
     }
       SIMD_BINOP_CASE(kArm64I32x4Add, Add, 4S);
@@ -2120,20 +2120,29 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_WIDENING_UNOP_CASE(kArm64I32x4UConvertI16x8Low, Uxtl, 4S, 4H);
       SIMD_WIDENING_UNOP_CASE(kArm64I32x4UConvertI16x8High, Uxtl2, 4S, 8H);
     case kArm64I32x4ShrU: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 32.
-      __ And(shift, i.InputRegister32(1), 31);
-      __ Dup(tmp.V4S(), shift);
-      __ Neg(tmp.V4S(), tmp.V4S());
-      __ Ushl(i.OutputSimd128Register().V4S(), i.InputSimd128Register(0).V4S(),
-              tmp.V4S());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Ushr, 5, V4S, Ushl, W);
       break;
     }
       SIMD_BINOP_CASE(kArm64I32x4MinU, Umin, 4S);
       SIMD_BINOP_CASE(kArm64I32x4MaxU, Umax, 4S);
       SIMD_BINOP_CASE(kArm64I32x4GtU, Cmhi, 4S);
       SIMD_BINOP_CASE(kArm64I32x4GeU, Cmhs, 4S);
+      SIMD_UNOP_CASE(kArm64I32x4Abs, Abs, 4S);
+    case kArm64I32x4BitMask: {
+      Register dst = i.OutputRegister32();
+      VRegister src = i.InputSimd128Register(0);
+      VRegister tmp = i.TempSimd128Register(0);
+      VRegister mask = i.TempSimd128Register(1);
+
+      __ Sshr(tmp.V4S(), src.V4S(), 31);
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ Movi(mask.V2D(), 0x0000'0008'0000'0004, 0x0000'0002'0000'0001);
+      __ And(tmp.V16B(), mask.V16B(), tmp.V16B());
+      __ Addv(tmp.S(), tmp.V4S());
+      __ Mov(dst.W(), tmp.V4S(), 0);
+      break;
+    }
     case kArm64I16x8Splat: {
       __ Dup(i.OutputSimd128Register().V8H(), i.InputRegister32(0));
       break;
@@ -2161,24 +2170,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_WIDENING_UNOP_CASE(kArm64I16x8SConvertI8x16High, Sxtl2, 8H, 16B);
       SIMD_UNOP_CASE(kArm64I16x8Neg, Neg, 8H);
     case kArm64I16x8Shl: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 16.
-      __ And(shift, i.InputRegister32(1), 15);
-      __ Dup(tmp.V8H(), shift);
-      __ Sshl(i.OutputSimd128Register().V8H(), i.InputSimd128Register(0).V8H(),
-              tmp.V8H());
+      ASSEMBLE_SIMD_SHIFT_LEFT(Shl, 4, V8H, Sshl, W);
       break;
     }
     case kArm64I16x8ShrS: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 16.
-      __ And(shift, i.InputRegister32(1), 15);
-      __ Dup(tmp.V8H(), shift);
-      __ Neg(tmp.V8H(), tmp.V8H());
-      __ Sshl(i.OutputSimd128Register().V8H(), i.InputSimd128Register(0).V8H(),
-              tmp.V8H());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Sshr, 4, V8H, Sshl, W);
       break;
     }
     case kArm64I16x8SConvertI32x4: {
@@ -2223,14 +2219,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kArm64I16x8ShrU: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 16.
-      __ And(shift, i.InputRegister32(1), 15);
-      __ Dup(tmp.V8H(), shift);
-      __ Neg(tmp.V8H(), tmp.V8H());
-      __ Ushl(i.OutputSimd128Register().V8H(), i.InputSimd128Register(0).V8H(),
-              tmp.V8H());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Ushr, 4, V8H, Ushl, W);
       break;
     }
     case kArm64I16x8UConvertI32x4: {
@@ -2254,6 +2243,22 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_BINOP_CASE(kArm64I16x8GtU, Cmhi, 8H);
       SIMD_BINOP_CASE(kArm64I16x8GeU, Cmhs, 8H);
       SIMD_BINOP_CASE(kArm64I16x8RoundingAverageU, Urhadd, 8H);
+      SIMD_UNOP_CASE(kArm64I16x8Abs, Abs, 8H);
+    case kArm64I16x8BitMask: {
+      Register dst = i.OutputRegister32();
+      VRegister src = i.InputSimd128Register(0);
+      VRegister tmp = i.TempSimd128Register(0);
+      VRegister mask = i.TempSimd128Register(1);
+
+      __ Sshr(tmp.V8H(), src.V8H(), 15);
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ Movi(mask.V2D(), 0x0080'0040'0020'0010, 0x0008'0004'0002'0001);
+      __ And(tmp.V16B(), mask.V16B(), tmp.V16B());
+      __ Addv(tmp.H(), tmp.V8H());
+      __ Mov(dst.W(), tmp.V8H(), 0);
+      break;
+    }
     case kArm64I8x16Splat: {
       __ Dup(i.OutputSimd128Register().V16B(), i.InputRegister32(0));
       break;
@@ -2279,24 +2284,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
       SIMD_UNOP_CASE(kArm64I8x16Neg, Neg, 16B);
     case kArm64I8x16Shl: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 8.
-      __ And(shift, i.InputRegister32(1), 7);
-      __ Dup(tmp.V16B(), shift);
-      __ Sshl(i.OutputSimd128Register().V16B(),
-              i.InputSimd128Register(0).V16B(), tmp.V16B());
+      ASSEMBLE_SIMD_SHIFT_LEFT(Shl, 3, V16B, Sshl, W);
       break;
     }
     case kArm64I8x16ShrS: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 8.
-      __ And(shift, i.InputRegister32(1), 7);
-      __ Dup(tmp.V16B(), shift);
-      __ Neg(tmp.V16B(), tmp.V16B());
-      __ Sshl(i.OutputSimd128Register().V16B(),
-              i.InputSimd128Register(0).V16B(), tmp.V16B());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Sshr, 3, V16B, Sshl, W);
       break;
     }
     case kArm64I8x16SConvertI16x8: {
@@ -2331,14 +2323,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_BINOP_CASE(kArm64I8x16GtS, Cmgt, 16B);
       SIMD_BINOP_CASE(kArm64I8x16GeS, Cmge, 16B);
     case kArm64I8x16ShrU: {
-      VRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.TempRegister32(1);
-      // Take shift value modulo 8.
-      __ And(shift, i.InputRegister32(1), 7);
-      __ Dup(tmp.V16B(), shift);
-      __ Neg(tmp.V16B(), tmp.V16B());
-      __ Ushl(i.OutputSimd128Register().V16B(),
-              i.InputSimd128Register(0).V16B(), tmp.V16B());
+      ASSEMBLE_SIMD_SHIFT_RIGHT(Ushr, 3, V16B, Ushl, W);
       break;
     }
     case kArm64I8x16UConvertI16x8: {
@@ -2362,6 +2347,24 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       SIMD_BINOP_CASE(kArm64I8x16GtU, Cmhi, 16B);
       SIMD_BINOP_CASE(kArm64I8x16GeU, Cmhs, 16B);
       SIMD_BINOP_CASE(kArm64I8x16RoundingAverageU, Urhadd, 16B);
+      SIMD_UNOP_CASE(kArm64I8x16Abs, Abs, 16B);
+    case kArm64I8x16BitMask: {
+      Register dst = i.OutputRegister32();
+      VRegister src = i.InputSimd128Register(0);
+      VRegister tmp = i.TempSimd128Register(0);
+      VRegister mask = i.TempSimd128Register(1);
+
+      // Set i-th bit of each lane i. When AND with tmp, the lanes that
+      // are signed will have i-th bit set, unsigned will be 0.
+      __ Sshr(tmp.V16B(), src.V16B(), 7);
+      __ Movi(mask.V2D(), 0x8040'2010'0804'0201);
+      __ And(tmp.V16B(), mask.V16B(), tmp.V16B());
+      __ Ext(mask.V16B(), tmp.V16B(), tmp.V16B(), 8);
+      __ Zip1(tmp.V16B(), tmp.V16B(), mask.V16B());
+      __ Addv(tmp.H(), tmp.V8H());
+      __ Mov(dst.W(), tmp.V8H(), 0);
+      break;
+    }
     case kArm64S128Zero: {
       __ Movi(i.OutputSimd128Register().V16B(), 0);
       break;
@@ -2573,6 +2576,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #undef SIMD_WIDENING_UNOP_CASE
 #undef SIMD_BINOP_CASE
 #undef SIMD_REDUCE_OP_CASE
+#undef ASSEMBLE_SIMD_SHIFT_LEFT
+#undef ASSEMBLE_SIMD_SHIFT_RIGHT
 
 // Assemble branches after this instruction.
 void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
@@ -2734,16 +2739,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  Arm64OperandConverter i(this, instr);
-  Register input = i.InputRegister32(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ Cmp(input, i.InputInt32(index + 0));
-    __ B(eq, GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   Arm64OperandConverter i(this, instr);
   UseScratchRegisterScope scope(tasm());
@@ -2754,15 +2749,21 @@ void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   __ Cmp(input, case_count);
   __ B(hs, GetLabel(i.InputRpo(1)));
   __ Adr(temp, &table);
-  __ Add(temp, temp, Operand(input, UXTW, 2));
+  int entry_size_log2 = 2;
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  ++entry_size_log2;  // Account for BTI.
+#endif
+  __ Add(temp, temp, Operand(input, UXTW, entry_size_log2));
   __ Br(temp);
   {
     TurboAssembler::BlockPoolsScope block_pools(tasm(),
                                                 case_count * kInstrSize);
     __ Bind(&table);
     for (size_t index = 0; index < case_count; ++index) {
+      __ JumpTarget();
       __ B(GetLabel(i.InputRpo(index + 2)));
     }
+    __ JumpTarget();
   }
 }
 
@@ -2801,8 +2802,10 @@ void CodeGenerator::AssembleConstructFrame() {
 
   CPURegList saves = CPURegList(CPURegister::kRegister, kXRegSizeInBits,
                                 call_descriptor->CalleeSavedRegisters());
+  DCHECK_EQ(saves.Count() % 2, 0);
   CPURegList saves_fp = CPURegList(CPURegister::kVRegister, kDRegSizeInBits,
                                    call_descriptor->CalleeSavedFPRegisters());
+  DCHECK_EQ(saves_fp.Count() % 2, 0);
   // The number of slots for returns has to be even to ensure the correct stack
   // alignment.
   const int returns = RoundUp(frame()->GetReturnSlotCount(), 2);
@@ -2812,7 +2815,7 @@ void CodeGenerator::AssembleConstructFrame() {
     if (call_descriptor->IsJSFunctionCall()) {
       __ Prologue();
     } else {
-      __ Push(lr, fp);
+      __ Push<TurboAssembler::kSignLR>(lr, fp);
       __ Mov(fp, sp);
     }
     unwinding_info_writer_.MarkFrameConstructed(__ pc_offset());
@@ -2856,13 +2859,10 @@ void CodeGenerator::AssembleConstructFrame() {
       {
         // Finish the frame that hasn't been fully built yet.
         UseScratchRegisterScope temps(tasm());
-        __ Claim(2);  // Claim extra slots for marker + instance.
         Register scratch = temps.AcquireX();
         __ Mov(scratch,
                StackFrame::TypeToMarker(info()->GetOutputStackFrameType()));
-        __ Str(scratch, MemOperand(fp, TypedFrameConstants::kFrameTypeOffset));
-        __ Str(kWasmInstanceRegister,
-               MemOperand(fp, WasmCompiledFrameConstants::kWasmInstanceOffset));
+        __ Push(scratch, kWasmInstanceRegister);
       }
 
       __ Call(wasm::WasmCode::kWasmStackOverflow, RelocInfo::WASM_STUB_CALL);
@@ -2896,23 +2896,25 @@ void CodeGenerator::AssembleConstructFrame() {
         break;
       case CallDescriptor::kCallCodeObject: {
         UseScratchRegisterScope temps(tasm());
-        __ Claim(required_slots +
-                 1);  // Claim extra slot for frame type marker.
         Register scratch = temps.AcquireX();
         __ Mov(scratch,
                StackFrame::TypeToMarker(info()->GetOutputStackFrameType()));
-        __ Str(scratch, MemOperand(fp, TypedFrameConstants::kFrameTypeOffset));
+        __ Push(scratch, padreg);
+        // One of the extra slots has just been claimed when pushing the frame
+        // type marker above. We also know that we have at least one slot to
+        // claim here, as the typed frame has an odd number of fixed slots, and
+        // all other parts of the total frame slots are even, leaving
+        // {required_slots} to be odd.
+        DCHECK_GE(required_slots, 1);
+        __ Claim(required_slots - 1);
       } break;
       case CallDescriptor::kCallWasmFunction: {
         UseScratchRegisterScope temps(tasm());
-        __ Claim(required_slots +
-                 2);  // Claim extra slots for marker + instance.
         Register scratch = temps.AcquireX();
         __ Mov(scratch,
                StackFrame::TypeToMarker(info()->GetOutputStackFrameType()));
-        __ Str(scratch, MemOperand(fp, TypedFrameConstants::kFrameTypeOffset));
-        __ Str(kWasmInstanceRegister,
-               MemOperand(fp, WasmCompiledFrameConstants::kWasmInstanceOffset));
+        __ Push(scratch, kWasmInstanceRegister);
+        __ Claim(required_slots);
       } break;
       case CallDescriptor::kCallWasmImportWrapper:
       case CallDescriptor::kCallWasmCapiFunction: {
@@ -2923,30 +2925,25 @@ void CodeGenerator::AssembleConstructFrame() {
         __ LoadTaggedPointerField(
             kWasmInstanceRegister,
             FieldMemOperand(kWasmInstanceRegister, Tuple2::kValue1Offset));
-        int extra_slots =
-            call_descriptor->kind() == CallDescriptor::kCallWasmImportWrapper
-                ? 2   // Import wrapper: marker + instance.
-                : 3;  // C-API function: marker + instance + PC.
-        __ Claim(required_slots + extra_slots);
         Register scratch = temps.AcquireX();
         __ Mov(scratch,
                StackFrame::TypeToMarker(info()->GetOutputStackFrameType()));
-        __ Str(scratch, MemOperand(fp, TypedFrameConstants::kFrameTypeOffset));
-        __ Str(kWasmInstanceRegister,
-               MemOperand(fp, WasmCompiledFrameConstants::kWasmInstanceOffset));
+        __ Push(scratch, kWasmInstanceRegister);
+        int extra_slots =
+            call_descriptor->kind() == CallDescriptor::kCallWasmImportWrapper
+                ? 0   // Import wrapper: none.
+                : 1;  // C-API function: PC.
+        __ Claim(required_slots + extra_slots);
       } break;
       case CallDescriptor::kCallAddress:
         if (info()->GetOutputStackFrameType() == StackFrame::C_WASM_ENTRY) {
-          required_slots += 2;  // marker + saved c_entry_fp.
-        }
-        __ Claim(required_slots);
-        if (info()->GetOutputStackFrameType() == StackFrame::C_WASM_ENTRY) {
           UseScratchRegisterScope temps(tasm());
           Register scratch = temps.AcquireX();
           __ Mov(scratch, StackFrame::TypeToMarker(StackFrame::C_WASM_ENTRY));
-          __ Str(scratch,
-                 MemOperand(fp, TypedFrameConstants::kFrameTypeOffset));
+          __ Push(scratch, padreg);
+          // The additional slot will be used for the saved c_entry_fp.
         }
+        __ Claim(required_slots);
         break;
       default:
         UNREACHABLE();
@@ -2959,10 +2956,9 @@ void CodeGenerator::AssembleConstructFrame() {
   __ PushCPURegList(saves_fp);
 
   // Save registers.
-  // TODO(palfia): TF save list is not in sync with
-  // CPURegList::GetCalleeSaved(): x30 is missing.
-  // DCHECK(saves.list() == CPURegList::GetCalleeSaved().list());
-  __ PushCPURegList(saves);
+  DCHECK_IMPLIES(!saves.IsEmpty(),
+                 saves.list() == CPURegList::GetCalleeSaved().list());
+  __ PushCPURegList<TurboAssembler::kSignLR>(saves);
 
   if (returns != 0) {
     __ Claim(returns);
@@ -2981,7 +2977,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* pop) {
   // Restore registers.
   CPURegList saves = CPURegList(CPURegister::kRegister, kXRegSizeInBits,
                                 call_descriptor->CalleeSavedRegisters());
-  __ PopCPURegList(saves);
+  __ PopCPURegList<TurboAssembler::kAuthLR>(saves);
 
   // Restore fp registers.
   CPURegList saves_fp = CPURegList(CPURegister::kVRegister, kDRegSizeInBits,
@@ -3027,7 +3023,11 @@ void CodeGenerator::FinishCode() { __ ForceConstantPoolEmissionWithoutJump(); }
 
 void CodeGenerator::PrepareForDeoptimizationExits(int deopt_count) {
   __ ForceConstantPoolEmissionWithoutJump();
-  __ CheckVeneerPool(false, false, deopt_count * Deoptimizer::kDeoptExitSize);
+  // We are conservative here, assuming all deopts are lazy deopts.
+  DCHECK_GE(Deoptimizer::kLazyDeoptExitSize,
+            Deoptimizer::kNonLazyDeoptExitSize);
+  __ CheckVeneerPool(false, false,
+                     deopt_count * Deoptimizer::kLazyDeoptExitSize);
 }
 
 void CodeGenerator::AssembleMove(InstructionOperand* source,
diff --git a/deps/v8/src/compiler/backend/arm64/instruction-codes-arm64.h b/deps/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
index 0e78a346a6..e24812f884 100644
--- a/deps/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
+++ b/deps/v8/src/compiler/backend/arm64/instruction-codes-arm64.h
@@ -252,6 +252,8 @@ namespace compiler {
   V(Arm64I32x4MaxU)                         \
   V(Arm64I32x4GtU)                          \
   V(Arm64I32x4GeU)                          \
+  V(Arm64I32x4Abs)                          \
+  V(Arm64I32x4BitMask)                      \
   V(Arm64I16x8Splat)                        \
   V(Arm64I16x8ExtractLaneU)                 \
   V(Arm64I16x8ExtractLaneS)                 \
@@ -285,6 +287,8 @@ namespace compiler {
   V(Arm64I16x8GtU)                          \
   V(Arm64I16x8GeU)                          \
   V(Arm64I16x8RoundingAverageU)             \
+  V(Arm64I16x8Abs)                          \
+  V(Arm64I16x8BitMask)                      \
   V(Arm64I8x16Splat)                        \
   V(Arm64I8x16ExtractLaneU)                 \
   V(Arm64I8x16ExtractLaneS)                 \
@@ -313,6 +317,8 @@ namespace compiler {
   V(Arm64I8x16GtU)                          \
   V(Arm64I8x16GeU)                          \
   V(Arm64I8x16RoundingAverageU)             \
+  V(Arm64I8x16Abs)                          \
+  V(Arm64I8x16BitMask)                      \
   V(Arm64S128Zero)                          \
   V(Arm64S128Dup)                           \
   V(Arm64S128And)                           \
diff --git a/deps/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc b/deps/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
index f032e333c1..72a0b1b012 100644
--- a/deps/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
+++ b/deps/v8/src/compiler/backend/arm64/instruction-scheduler-arm64.cc
@@ -222,6 +222,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArm64I32x4MaxU:
     case kArm64I32x4GtU:
     case kArm64I32x4GeU:
+    case kArm64I32x4Abs:
+    case kArm64I32x4BitMask:
     case kArm64I16x8Splat:
     case kArm64I16x8ExtractLaneU:
     case kArm64I16x8ExtractLaneS:
@@ -255,6 +257,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArm64I16x8GtU:
     case kArm64I16x8GeU:
     case kArm64I16x8RoundingAverageU:
+    case kArm64I16x8Abs:
+    case kArm64I16x8BitMask:
     case kArm64I8x16Splat:
     case kArm64I8x16ExtractLaneU:
     case kArm64I8x16ExtractLaneS:
@@ -283,6 +287,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kArm64I8x16GtU:
     case kArm64I8x16GeU:
     case kArm64I8x16RoundingAverageU:
+    case kArm64I8x16Abs:
+    case kArm64I8x16BitMask:
     case kArm64S128Zero:
     case kArm64S128Dup:
     case kArm64S128And:
diff --git a/deps/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc b/deps/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
index 3c7c337537..bb204f62a6 100644
--- a/deps/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
+++ b/deps/v8/src/compiler/backend/arm64/instruction-selector-arm64.cc
@@ -152,12 +152,25 @@ void VisitRRR(InstructionSelector* selector, ArchOpcode opcode, Node* node) {
 }
 
 void VisitSimdShiftRRR(InstructionSelector* selector, ArchOpcode opcode,
-                       Node* node) {
+                       Node* node, int width) {
   Arm64OperandGenerator g(selector);
-  InstructionOperand temps[] = {g.TempSimd128Register(), g.TempRegister()};
-  selector->Emit(opcode, g.DefineAsRegister(node),
-                 g.UseRegister(node->InputAt(0)),
-                 g.UseRegister(node->InputAt(1)), arraysize(temps), temps);
+  if (g.IsIntegerConstant(node->InputAt(1))) {
+    if (g.GetIntegerConstantValue(node->InputAt(1)) % width == 0) {
+      selector->EmitIdentity(node);
+    } else {
+      selector->Emit(opcode, g.DefineAsRegister(node),
+                     g.UseRegister(node->InputAt(0)),
+                     g.UseImmediate(node->InputAt(1)));
+    }
+  } else {
+    InstructionOperand temps[] = {g.TempSimd128Register(), g.TempRegister()};
+    // We only need a unique register for the first input (src), since in
+    // the codegen we use tmp to store the shifts, and then later use it with
+    // src. The second input can be the same as the second temp (shift).
+    selector->Emit(opcode, g.DefineAsRegister(node),
+                   g.UseUniqueRegister(node->InputAt(0)),
+                   g.UseRegister(node->InputAt(1)), arraysize(temps), temps);
+  }
 }
 
 void VisitRRI(InstructionSelector* selector, ArchOpcode opcode, Node* node) {
@@ -2578,7 +2591,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   Arm64OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -3157,12 +3170,15 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I32x4UConvertF32x4, kArm64I32x4UConvertF32x4)         \
   V(I32x4UConvertI16x8Low, kArm64I32x4UConvertI16x8Low)   \
   V(I32x4UConvertI16x8High, kArm64I32x4UConvertI16x8High) \
+  V(I32x4Abs, kArm64I32x4Abs)                             \
   V(I16x8SConvertI8x16Low, kArm64I16x8SConvertI8x16Low)   \
   V(I16x8SConvertI8x16High, kArm64I16x8SConvertI8x16High) \
   V(I16x8Neg, kArm64I16x8Neg)                             \
   V(I16x8UConvertI8x16Low, kArm64I16x8UConvertI8x16Low)   \
   V(I16x8UConvertI8x16High, kArm64I16x8UConvertI8x16High) \
+  V(I16x8Abs, kArm64I16x8Abs)                             \
   V(I8x16Neg, kArm64I8x16Neg)                             \
+  V(I8x16Abs, kArm64I8x16Abs)                             \
   V(S128Not, kArm64S128Not)                               \
   V(S1x2AnyTrue, kArm64S1x2AnyTrue)                       \
   V(S1x2AllTrue, kArm64S1x2AllTrue)                       \
@@ -3174,18 +3190,18 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(S1x16AllTrue, kArm64S1x16AllTrue)
 
 #define SIMD_SHIFT_OP_LIST(V) \
-  V(I64x2Shl)                 \
-  V(I64x2ShrS)                \
-  V(I64x2ShrU)                \
-  V(I32x4Shl)                 \
-  V(I32x4ShrS)                \
-  V(I32x4ShrU)                \
-  V(I16x8Shl)                 \
-  V(I16x8ShrS)                \
-  V(I16x8ShrU)                \
-  V(I8x16Shl)                 \
-  V(I8x16ShrS)                \
-  V(I8x16ShrU)
+  V(I64x2Shl, 64)             \
+  V(I64x2ShrS, 64)            \
+  V(I64x2ShrU, 64)            \
+  V(I32x4Shl, 32)             \
+  V(I32x4ShrS, 32)            \
+  V(I32x4ShrU, 32)            \
+  V(I16x8Shl, 16)             \
+  V(I16x8ShrS, 16)            \
+  V(I16x8ShrU, 16)            \
+  V(I8x16Shl, 8)              \
+  V(I8x16ShrS, 8)             \
+  V(I8x16ShrU, 8)
 
 #define SIMD_BINOP_LIST(V)                              \
   V(F64x2Add, kArm64F64x2Add)                           \
@@ -3319,9 +3335,9 @@ SIMD_UNOP_LIST(SIMD_VISIT_UNOP)
 #undef SIMD_VISIT_UNOP
 #undef SIMD_UNOP_LIST
 
-#define SIMD_VISIT_SHIFT_OP(Name)                     \
-  void InstructionSelector::Visit##Name(Node* node) { \
-    VisitSimdShiftRRR(this, kArm64##Name, node);      \
+#define SIMD_VISIT_SHIFT_OP(Name, width)                \
+  void InstructionSelector::Visit##Name(Node* node) {   \
+    VisitSimdShiftRRR(this, kArm64##Name, node, width); \
   }
 SIMD_SHIFT_OP_LIST(SIMD_VISIT_SHIFT_OP)
 #undef SIMD_VISIT_SHIFT_OP
@@ -3364,6 +3380,29 @@ VISIT_SIMD_QFMOP(F32x4Qfms)
 #undef VISIT_SIMD_QFMOP
 
 namespace {
+template <ArchOpcode opcode>
+void VisitBitMask(InstructionSelector* selector, Node* node) {
+  Arm64OperandGenerator g(selector);
+  InstructionOperand temps[] = {g.TempSimd128Register(),
+                                g.TempSimd128Register()};
+  selector->Emit(opcode, g.DefineAsRegister(node),
+                 g.UseRegister(node->InputAt(0)), arraysize(temps), temps);
+}
+}  // namespace
+
+void InstructionSelector::VisitI8x16BitMask(Node* node) {
+  VisitBitMask<kArm64I8x16BitMask>(this, node);
+}
+
+void InstructionSelector::VisitI16x8BitMask(Node* node) {
+  VisitBitMask<kArm64I16x8BitMask>(this, node);
+}
+
+void InstructionSelector::VisitI32x4BitMask(Node* node) {
+  VisitBitMask<kArm64I32x4BitMask>(this, node);
+}
+
+namespace {
 
 struct ShuffleEntry {
   uint8_t shuffle[kSimd128Size];
diff --git a/deps/v8/src/compiler/backend/arm64/unwinding-info-writer-arm64.cc b/deps/v8/src/compiler/backend/arm64/unwinding-info-writer-arm64.cc
index 3747019c7d..c8a570af53 100644
--- a/deps/v8/src/compiler/backend/arm64/unwinding-info-writer-arm64.cc
+++ b/deps/v8/src/compiler/backend/arm64/unwinding-info-writer-arm64.cc
@@ -9,6 +9,9 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+// TODO(v8:10026): When using CFI, we need to generate unwinding info to tell
+// the unwinder that return addresses are signed.
+
 void UnwindingInfoWriter::BeginInstructionBlock(int pc_offset,
                                                 const InstructionBlock* block) {
   if (!enabled()) return;
diff --git a/deps/v8/src/compiler/backend/code-generator-impl.h b/deps/v8/src/compiler/backend/code-generator-impl.h
index 530dc0a813..e335135240 100644
--- a/deps/v8/src/compiler/backend/code-generator-impl.h
+++ b/deps/v8/src/compiler/backend/code-generator-impl.h
@@ -62,6 +62,10 @@ class InstructionOperandConverter {
     return static_cast<int8_t>(InputInt32(index));
   }
 
+  uint8_t InputUint8(size_t index) {
+    return bit_cast<uint8_t>(InputInt8(index));
+  }
+
   int16_t InputInt16(size_t index) {
     return static_cast<int16_t>(InputInt32(index));
   }
diff --git a/deps/v8/src/compiler/backend/code-generator.cc b/deps/v8/src/compiler/backend/code-generator.cc
index a441a36496..9dbd5fac33 100644
--- a/deps/v8/src/compiler/backend/code-generator.cc
+++ b/deps/v8/src/compiler/backend/code-generator.cc
@@ -158,6 +158,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleDeoptimizerCall(
   }
 
   DeoptimizeKind deopt_kind = exit->kind();
+
   DeoptimizeReason deoptimization_reason = exit->reason();
   Address deopt_entry =
       Deoptimizer::GetDeoptimizationEntry(tasm()->isolate(), deopt_kind);
@@ -165,7 +166,16 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleDeoptimizerCall(
     tasm()->RecordDeoptReason(deoptimization_reason, exit->pos(),
                               deoptimization_id);
   }
-  tasm()->CallForDeoptimization(deopt_entry, deoptimization_id);
+
+  if (deopt_kind == DeoptimizeKind::kLazy) {
+    tasm()->BindExceptionHandler(exit->label());
+  } else {
+    ++non_lazy_deopt_count_;
+    tasm()->bind(exit->label());
+  }
+
+  tasm()->CallForDeoptimization(deopt_entry, deoptimization_id, exit->label(),
+                                deopt_kind);
   exit->set_emitted();
   return kSuccess;
 }
@@ -186,6 +196,9 @@ void CodeGenerator::AssembleCode() {
     AssembleSourcePosition(start_source_position());
   }
   offsets_info_.code_start_register_check = tasm()->pc_offset();
+
+  tasm()->CodeEntry();
+
   // Check that {kJavaScriptCallCodeStartRegister} has been set correctly.
   if (FLAG_debug_code && (info->code_kind() == Code::OPTIMIZED_FUNCTION ||
                           info->code_kind() == Code::BYTECODE_HANDLER)) {
@@ -312,31 +325,49 @@ void CodeGenerator::AssembleCode() {
   // emitted before emitting the deoptimization exits.
   PrepareForDeoptimizationExits(static_cast<int>(deoptimization_exits_.size()));
 
-  if (Deoptimizer::kSupportsFixedDeoptExitSize) {
+  if (Deoptimizer::kSupportsFixedDeoptExitSizes) {
     deopt_exit_start_offset_ = tasm()->pc_offset();
   }
 
   // Assemble deoptimization exits.
   offsets_info_.deoptimization_exits = tasm()->pc_offset();
   int last_updated = 0;
+  // We sort the deoptimization exits here so that the lazy ones will
+  // be visited last. We need this as on architectures where
+  // Deoptimizer::kSupportsFixedDeoptExitSizes is true, lazy deopts
+  // might need additional instructions.
+  auto cmp = [](const DeoptimizationExit* a, const DeoptimizationExit* b) {
+    static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kEager,
+                  "lazy deopts are expected to be emitted last");
+    static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kSoft,
+                  "lazy deopts are expected to be emitted last");
+    if (a->kind() != b->kind()) {
+      return a->kind() < b->kind();
+    }
+    return a->pc_offset() < b->pc_offset();
+  };
+  if (Deoptimizer::kSupportsFixedDeoptExitSizes) {
+    std::sort(deoptimization_exits_.begin(), deoptimization_exits_.end(), cmp);
+  }
+
   for (DeoptimizationExit* exit : deoptimization_exits_) {
     if (exit->emitted()) continue;
-    if (Deoptimizer::kSupportsFixedDeoptExitSize) {
+    if (Deoptimizer::kSupportsFixedDeoptExitSizes) {
       exit->set_deoptimization_id(next_deoptimization_id_++);
     }
-    tasm()->bind(exit->label());
+    result_ = AssembleDeoptimizerCall(exit);
+    if (result_ != kSuccess) return;
 
     // UpdateDeoptimizationInfo expects lazy deopts to be visited in pc_offset
     // order, which is always the case since they are added to
-    // deoptimization_exits_ in that order.
+    // deoptimization_exits_ in that order, and the optional sort operation
+    // above preserves that order.
     if (exit->kind() == DeoptimizeKind::kLazy) {
-      int trampoline_pc = tasm()->pc_offset();
+      int trampoline_pc = exit->label()->pos();
       last_updated = safepoints()->UpdateDeoptimizationInfo(
           exit->pc_offset(), trampoline_pc, last_updated,
           exit->deoptimization_id());
     }
-    result_ = AssembleDeoptimizerCall(exit);
-    if (result_ != kSuccess) return;
   }
 
   offsets_info_.pools = tasm()->pc_offset();
@@ -432,10 +463,9 @@ OwnedVector<byte> CodeGenerator::GetSourcePositionTable() {
   return source_position_table_builder_.ToSourcePositionTableVector();
 }
 
-OwnedVector<trap_handler::ProtectedInstructionData>
-CodeGenerator::GetProtectedInstructions() {
-  return OwnedVector<trap_handler::ProtectedInstructionData>::Of(
-      protected_instructions_);
+OwnedVector<byte> CodeGenerator::GetProtectedInstructionsData() {
+  return OwnedVector<byte>::Of(
+      Vector<byte>::cast(VectorOf(protected_instructions_)));
 }
 
 MaybeHandle<Code> CodeGenerator::FinalizeCode() {
@@ -531,6 +561,9 @@ bool CodeGenerator::IsMaterializableFromRoot(Handle<HeapObject> object,
 
 CodeGenerator::CodeGenResult CodeGenerator::AssembleBlock(
     const InstructionBlock* block) {
+  if (block->IsHandler()) {
+    tasm()->ExceptionHandler();
+  }
   for (int i = block->code_start(); i < block->code_end(); ++i) {
     CodeGenResult result = AssembleInstruction(i, block);
     if (result != kSuccess) return result;
@@ -883,6 +916,7 @@ Handle<DeoptimizationData> CodeGenerator::GenerateDeoptimizationData() {
   data->SetOptimizationId(Smi::FromInt(info->optimization_id()));
 
   data->SetDeoptExitStart(Smi::FromInt(deopt_exit_start_offset_));
+  data->SetNonLazyDeoptCount(Smi::FromInt(non_lazy_deopt_count_));
 
   if (info->has_shared_info()) {
     data->SetSharedFunctionInfo(*info->shared_info());
@@ -944,6 +978,7 @@ void CodeGenerator::RecordCallPosition(Instruction* instr) {
   if (flags & CallDescriptor::kHasExceptionHandler) {
     InstructionOperandConverter i(this, instr);
     RpoNumber handler_rpo = i.InputRpo(instr->InputCount() - 1);
+    DCHECK(instructions()->InstructionBlockAt(handler_rpo)->IsHandler());
     handlers_.push_back({GetLabel(handler_rpo), tasm()->pc_offset()});
   }
 
@@ -1120,7 +1155,7 @@ DeoptimizationExit* CodeGenerator::BuildTranslation(
       current_source_position_, descriptor->bailout_id(), translation.index(),
       pc_offset, entry.kind(), entry.reason());
 
-  if (!Deoptimizer::kSupportsFixedDeoptExitSize) {
+  if (!Deoptimizer::kSupportsFixedDeoptExitSizes) {
     exit->set_deoptimization_id(next_deoptimization_id_++);
   }
 
diff --git a/deps/v8/src/compiler/backend/code-generator.h b/deps/v8/src/compiler/backend/code-generator.h
index e54d988b52..0caefddd97 100644
--- a/deps/v8/src/compiler/backend/code-generator.h
+++ b/deps/v8/src/compiler/backend/code-generator.h
@@ -125,8 +125,7 @@ class V8_EXPORT_PRIVATE CodeGenerator final : public GapResolver::Assembler {
   MaybeHandle<Code> FinalizeCode();
 
   OwnedVector<byte> GetSourcePositionTable();
-  OwnedVector<trap_handler::ProtectedInstructionData>
-  GetProtectedInstructions();
+  OwnedVector<byte> GetProtectedInstructionsData();
 
   InstructionSequence* instructions() const { return instructions_; }
   FrameAccessState* frame_access_state() const { return frame_access_state_; }
@@ -253,7 +252,6 @@ class V8_EXPORT_PRIVATE CodeGenerator final : public GapResolver::Assembler {
                                            std::pair<int32_t, Label*>* begin,
                                            std::pair<int32_t, Label*>* end);
   void AssembleArchBinarySearchSwitch(Instruction* instr);
-  void AssembleArchLookupSwitch(Instruction* instr);
   void AssembleArchTableSwitch(Instruction* instr);
 
   // Generates code that checks whether the {kJavaScriptCallCodeStartRegister}
@@ -425,6 +423,7 @@ class V8_EXPORT_PRIVATE CodeGenerator final : public GapResolver::Assembler {
   ZoneVector<HandlerInfo> handlers_;
   int next_deoptimization_id_ = 0;
   int deopt_exit_start_offset_ = 0;
+  int non_lazy_deopt_count_ = 0;
   ZoneDeque<DeoptimizationExit*> deoptimization_exits_;
   ZoneDeque<DeoptimizationLiteral> deoptimization_literals_;
   size_t inlined_function_count_ = 0;
diff --git a/deps/v8/src/compiler/backend/ia32/code-generator-ia32.cc b/deps/v8/src/compiler/backend/ia32/code-generator-ia32.cc
index 7484d91dbf..d397ba8241 100644
--- a/deps/v8/src/compiler/backend/ia32/code-generator-ia32.cc
+++ b/deps/v8/src/compiler/backend/ia32/code-generator-ia32.cc
@@ -493,6 +493,22 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     __ cmov(zero, dst, tmp);                         \
   } while (false)
 
+#define ASSEMBLE_SIMD_SHIFT(opcode, width)                          \
+  do {                                                              \
+    XMMRegister dst = i.OutputSimd128Register();                    \
+    DCHECK_EQ(dst, i.InputSimd128Register(0));                      \
+    if (HasImmediateInput(instr, 1)) {                              \
+      __ opcode(dst, dst, static_cast<byte>(i.InputInt##width(1))); \
+    } else {                                                        \
+      XMMRegister tmp = i.TempSimd128Register(0);                   \
+      Register shift = i.InputRegister(1);                          \
+      constexpr int mask = (1 << width) - 1;                        \
+      __ and_(shift, Immediate(mask));                              \
+      __ Movd(tmp, shift);                                          \
+      __ opcode(dst, dst, tmp);                                     \
+    }                                                               \
+  } while (false)
+
 void CodeGenerator::AssembleDeconstructFrame() {
   __ mov(esp, ebp);
   __ pop(ebp);
@@ -883,9 +899,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
@@ -905,7 +918,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ int3();
       break;
     case kArchDebugBreak:
-      __ int3();
+      __ DebugBreak();
       break;
     case kArchNop:
     case kArchThrowTerminator:
@@ -2021,12 +2034,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32I64x2Shl: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 64.
-      __ and_(shift, Immediate(63));
-      __ Movd(tmp, shift);
-      __ Psllq(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+      ASSEMBLE_SIMD_SHIFT(Psllq, 6);
       break;
     }
     case kIA32I64x2ShrS: {
@@ -2086,12 +2094,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32I64x2ShrU: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 64.
-      __ and_(shift, Immediate(63));
-      __ Movd(tmp, shift);
-      __ Psrlq(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+      ASSEMBLE_SIMD_SHIFT(Psrlq, 6);
       break;
     }
     case kSSEF32x4Splat: {
@@ -2487,44 +2490,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
-    case kSSEI32x4Shl: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ pslld(i.OutputSimd128Register(), tmp);
+    case kIA32I32x4Shl: {
+      ASSEMBLE_SIMD_SHIFT(Pslld, 5);
       break;
     }
-    case kAVXI32x4Shl: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ vpslld(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
-      break;
-    }
-    case kSSEI32x4ShrS: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ psrad(i.OutputSimd128Register(), tmp);
-      break;
-    }
-    case kAVXI32x4ShrS: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ vpsrad(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+    case kIA32I32x4ShrS: {
+      ASSEMBLE_SIMD_SHIFT(Psrad, 5);
       break;
     }
     case kSSEI32x4Add: {
@@ -2717,24 +2688,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Pmovzxwd(dst, dst);
       break;
     }
-    case kSSEI32x4ShrU: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ psrld(i.OutputSimd128Register(), tmp);
-      break;
-    }
-    case kAVXI32x4ShrU: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ and_(shift, 31);
-      __ movd(tmp, shift);
-      __ vpsrld(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+    case kIA32I32x4ShrU: {
+      ASSEMBLE_SIMD_SHIFT(Psrld, 5);
       break;
     }
     case kSSEI32x4MinU: {
@@ -2800,6 +2755,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ vpcmpeqd(i.OutputSimd128Register(), kScratchDoubleReg, src2);
       break;
     }
+    case kIA32I32x4Abs: {
+      __ Pabsd(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kIA32I16x8Splat: {
       XMMRegister dst = i.OutputSimd128Register();
       __ Movd(dst, i.InputOperand(0));
@@ -2851,44 +2810,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
-    case kSSEI16x8Shl: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ psllw(i.OutputSimd128Register(), tmp);
-      break;
-    }
-    case kAVXI16x8Shl: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ vpsllw(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+    case kIA32I16x8Shl: {
+      ASSEMBLE_SIMD_SHIFT(Psllw, 4);
       break;
     }
-    case kSSEI16x8ShrS: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ psraw(i.OutputSimd128Register(), tmp);
-      break;
-    }
-    case kAVXI16x8ShrS: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ vpsraw(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+    case kIA32I16x8ShrS: {
+      ASSEMBLE_SIMD_SHIFT(Psraw, 4);
       break;
     }
     case kSSEI16x8SConvertI32x4: {
@@ -3055,24 +2982,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Pmovzxbw(dst, dst);
       break;
     }
-    case kSSEI16x8ShrU: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ psrlw(i.OutputSimd128Register(), tmp);
-      break;
-    }
-    case kAVXI16x8ShrU: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ and_(shift, 15);
-      __ movd(tmp, shift);
-      __ vpsrlw(i.OutputSimd128Register(), i.InputSimd128Register(0), tmp);
+    case kIA32I16x8ShrU: {
+      ASSEMBLE_SIMD_SHIFT(Psrlw, 4);
       break;
     }
     case kSSEI16x8UConvertI32x4: {
@@ -3178,6 +3089,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                i.InputOperand(1));
       break;
     }
+    case kIA32I16x8Abs: {
+      __ Pabsw(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kIA32I8x16Splat: {
       XMMRegister dst = i.OutputSimd128Register();
       __ Movd(dst, i.InputOperand(0));
@@ -3231,63 +3146,65 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       }
       break;
     }
-    case kSSEI8x16Shl: {
+    case kIA32I8x16Shl: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      Register shift = i.InputRegister(1);
-      Register tmp = i.ToRegister(instr->TempAt(0));
-      XMMRegister tmp_simd = i.TempSimd128Register(1);
-      // Take shift value modulo 8.
-      __ and_(shift, 7);
-      // Mask off the unwanted bits before word-shifting.
-      __ pcmpeqw(kScratchDoubleReg, kScratchDoubleReg);
-      __ mov(tmp, shift);
-      __ add(tmp, Immediate(8));
-      __ movd(tmp_simd, tmp);
-      __ psrlw(kScratchDoubleReg, tmp_simd);
-      __ packuswb(kScratchDoubleReg, kScratchDoubleReg);
-      __ pand(dst, kScratchDoubleReg);
-      __ movd(tmp_simd, shift);
-      __ psllw(dst, tmp_simd);
-      break;
-    }
-    case kAVXI8x16Shl: {
-      CpuFeatureScope avx_scope(tasm(), AVX);
-      XMMRegister dst = i.OutputSimd128Register();
-      XMMRegister src = i.InputSimd128Register(0);
-      Register shift = i.InputRegister(1);
       Register tmp = i.ToRegister(instr->TempAt(0));
       XMMRegister tmp_simd = i.TempSimd128Register(1);
-      // Take shift value modulo 8.
-      __ and_(shift, 7);
-      // Mask off the unwanted bits before word-shifting.
-      __ vpcmpeqw(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg);
-      __ mov(tmp, shift);
-      __ add(tmp, Immediate(8));
-      __ movd(tmp_simd, tmp);
-      __ vpsrlw(kScratchDoubleReg, kScratchDoubleReg, tmp_simd);
-      __ vpackuswb(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg);
-      __ vpand(dst, src, kScratchDoubleReg);
-      __ movd(tmp_simd, shift);
-      __ vpsllw(dst, dst, tmp_simd);
+
+      if (HasImmediateInput(instr, 1)) {
+        // Perform 16-bit shift, then mask away low bits.
+        uint8_t shift = i.InputInt3(1);
+        __ Psllw(dst, dst, static_cast<byte>(shift));
+
+        uint8_t bmask = static_cast<uint8_t>(0xff << shift);
+        uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
+        __ mov(tmp, mask);
+        __ Movd(tmp_simd, tmp);
+        __ Pshufd(tmp_simd, tmp_simd, 0);
+        __ Pand(dst, tmp_simd);
+      } else {
+        Register shift = i.InputRegister(1);
+        // Take shift value modulo 8.
+        __ and_(shift, 7);
+        // Mask off the unwanted bits before word-shifting.
+        __ Pcmpeqw(kScratchDoubleReg, kScratchDoubleReg);
+        __ mov(tmp, shift);
+        __ add(tmp, Immediate(8));
+        __ Movd(tmp_simd, tmp);
+        __ Psrlw(kScratchDoubleReg, kScratchDoubleReg, tmp_simd);
+        __ Packuswb(kScratchDoubleReg, kScratchDoubleReg);
+        __ Pand(dst, kScratchDoubleReg);
+        __ Movd(tmp_simd, shift);
+        __ Psllw(dst, dst, tmp_simd);
+      }
       break;
     }
     case kIA32I8x16ShrS: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      Register tmp = i.ToRegister(instr->TempAt(0));
-      XMMRegister tmp_simd = i.TempSimd128Register(1);
-      // Unpack the bytes into words, do arithmetic shifts, and repack.
-      __ punpckhbw(kScratchDoubleReg, dst);
-      __ punpcklbw(dst, dst);
-      __ mov(tmp, i.InputRegister(1));
-      // Take shift value modulo 8.
-      __ and_(tmp, 7);
-      __ add(tmp, Immediate(8));
-      __ movd(tmp_simd, tmp);
-      __ psraw(kScratchDoubleReg, tmp_simd);
-      __ psraw(dst, tmp_simd);
-      __ packsswb(dst, kScratchDoubleReg);
+      if (HasImmediateInput(instr, 1)) {
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        uint8_t shift = i.InputInt3(1) + 8;
+        __ Psraw(kScratchDoubleReg, shift);
+        __ Psraw(dst, shift);
+        __ Packsswb(dst, kScratchDoubleReg);
+      } else {
+        Register tmp = i.ToRegister(instr->TempAt(0));
+        XMMRegister tmp_simd = i.TempSimd128Register(1);
+        // Unpack the bytes into words, do arithmetic shifts, and repack.
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        __ mov(tmp, i.InputRegister(1));
+        // Take shift value modulo 8.
+        __ and_(tmp, 7);
+        __ add(tmp, Immediate(8));
+        __ Movd(tmp_simd, tmp);
+        __ Psraw(kScratchDoubleReg, kScratchDoubleReg, tmp_simd);
+        __ Psraw(dst, dst, tmp_simd);
+        __ Packsswb(dst, kScratchDoubleReg);
+      }
       break;
     }
     case kSSEI8x16Add: {
@@ -3529,21 +3446,35 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kIA32I8x16ShrU: {
-      DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
       XMMRegister dst = i.OutputSimd128Register();
+      DCHECK_EQ(dst, i.InputSimd128Register(0));
       Register tmp = i.ToRegister(instr->TempAt(0));
       XMMRegister tmp_simd = i.TempSimd128Register(1);
-      // Unpack the bytes into words, do logical shifts, and repack.
-      __ punpckhbw(kScratchDoubleReg, dst);
-      __ punpcklbw(dst, dst);
-      __ mov(tmp, i.InputRegister(1));
-      // Take shift value modulo 8.
-      __ and_(tmp, 7);
-      __ add(tmp, Immediate(8));
-      __ movd(tmp_simd, tmp);
-      __ psrlw(kScratchDoubleReg, tmp_simd);
-      __ psrlw(dst, tmp_simd);
-      __ packuswb(dst, kScratchDoubleReg);
+
+      if (HasImmediateInput(instr, 1)) {
+        // Perform 16-bit shift, then mask away high bits.
+        uint8_t shift = i.InputInt3(1);
+        __ Psrlw(dst, dst, static_cast<byte>(shift));
+
+        uint8_t bmask = 0xff >> shift;
+        uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
+        __ mov(tmp, mask);
+        __ Movd(tmp_simd, tmp);
+        __ Pshufd(tmp_simd, tmp_simd, 0);
+        __ Pand(dst, tmp_simd);
+      } else {
+        // Unpack the bytes into words, do logical shifts, and repack.
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        __ mov(tmp, i.InputRegister(1));
+        // Take shift value modulo 8.
+        __ and_(tmp, 7);
+        __ add(tmp, Immediate(8));
+        __ Movd(tmp_simd, tmp);
+        __ Psrlw(kScratchDoubleReg, kScratchDoubleReg, tmp_simd);
+        __ Psrlw(dst, dst, tmp_simd);
+        __ Packuswb(dst, kScratchDoubleReg);
+      }
       break;
     }
     case kSSEI8x16MinU: {
@@ -3611,6 +3542,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                i.InputOperand(1));
       break;
     }
+    case kIA32I8x16Abs: {
+      __ Pabsb(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kIA32S128Zero: {
       XMMRegister dst = i.OutputSimd128Register();
       __ Pxor(dst, dst);
@@ -4503,16 +4438,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  IA32OperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ cmp(input, Immediate(i.InputInt32(index + 0)));
-    __ j(equal, GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   IA32OperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -4689,7 +4614,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
@@ -5086,6 +5011,7 @@ void CodeGenerator::AssembleJumpTable(Label** targets, size_t target_count) {
 #undef ASSEMBLE_SIMD_PUNPCK_SHUFFLE
 #undef ASSEMBLE_SIMD_IMM_SHUFFLE
 #undef ASSEMBLE_SIMD_ALL_TRUE
+#undef ASSEMBLE_SIMD_SHIFT
 
 }  // namespace compiler
 }  // namespace internal
diff --git a/deps/v8/src/compiler/backend/ia32/instruction-codes-ia32.h b/deps/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
index d53c1ecc01..b4c90e2711 100644
--- a/deps/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
+++ b/deps/v8/src/compiler/backend/ia32/instruction-codes-ia32.h
@@ -190,10 +190,8 @@ namespace compiler {
   V(IA32I32x4SConvertI16x8Low)     \
   V(IA32I32x4SConvertI16x8High)    \
   V(IA32I32x4Neg)                  \
-  V(SSEI32x4Shl)                   \
-  V(AVXI32x4Shl)                   \
-  V(SSEI32x4ShrS)                  \
-  V(AVXI32x4ShrS)                  \
+  V(IA32I32x4Shl)                  \
+  V(IA32I32x4ShrS)                 \
   V(SSEI32x4Add)                   \
   V(AVXI32x4Add)                   \
   V(SSEI32x4AddHoriz)              \
@@ -218,8 +216,7 @@ namespace compiler {
   V(AVXI32x4UConvertF32x4)         \
   V(IA32I32x4UConvertI16x8Low)     \
   V(IA32I32x4UConvertI16x8High)    \
-  V(SSEI32x4ShrU)                  \
-  V(AVXI32x4ShrU)                  \
+  V(IA32I32x4ShrU)                 \
   V(SSEI32x4MinU)                  \
   V(AVXI32x4MinU)                  \
   V(SSEI32x4MaxU)                  \
@@ -228,6 +225,7 @@ namespace compiler {
   V(AVXI32x4GtU)                   \
   V(SSEI32x4GeU)                   \
   V(AVXI32x4GeU)                   \
+  V(IA32I32x4Abs)                  \
   V(IA32I16x8Splat)                \
   V(IA32I16x8ExtractLaneU)         \
   V(IA32I16x8ExtractLaneS)         \
@@ -236,10 +234,8 @@ namespace compiler {
   V(IA32I16x8SConvertI8x16Low)     \
   V(IA32I16x8SConvertI8x16High)    \
   V(IA32I16x8Neg)                  \
-  V(SSEI16x8Shl)                   \
-  V(AVXI16x8Shl)                   \
-  V(SSEI16x8ShrS)                  \
-  V(AVXI16x8ShrS)                  \
+  V(IA32I16x8Shl)                  \
+  V(IA32I16x8ShrS)                 \
   V(SSEI16x8SConvertI32x4)         \
   V(AVXI16x8SConvertI32x4)         \
   V(SSEI16x8Add)                   \
@@ -268,8 +264,7 @@ namespace compiler {
   V(AVXI16x8GeS)                   \
   V(IA32I16x8UConvertI8x16Low)     \
   V(IA32I16x8UConvertI8x16High)    \
-  V(SSEI16x8ShrU)                  \
-  V(AVXI16x8ShrU)                  \
+  V(IA32I16x8ShrU)                 \
   V(SSEI16x8UConvertI32x4)         \
   V(AVXI16x8UConvertI32x4)         \
   V(SSEI16x8AddSaturateU)          \
@@ -285,6 +280,7 @@ namespace compiler {
   V(SSEI16x8GeU)                   \
   V(AVXI16x8GeU)                   \
   V(IA32I16x8RoundingAverageU)     \
+  V(IA32I16x8Abs)                  \
   V(IA32I8x16Splat)                \
   V(IA32I8x16ExtractLaneU)         \
   V(IA32I8x16ExtractLaneS)         \
@@ -293,8 +289,7 @@ namespace compiler {
   V(SSEI8x16SConvertI16x8)         \
   V(AVXI8x16SConvertI16x8)         \
   V(IA32I8x16Neg)                  \
-  V(SSEI8x16Shl)                   \
-  V(AVXI8x16Shl)                   \
+  V(IA32I8x16Shl)                  \
   V(IA32I8x16ShrS)                 \
   V(SSEI8x16Add)                   \
   V(AVXI8x16Add)                   \
@@ -334,6 +329,7 @@ namespace compiler {
   V(SSEI8x16GeU)                   \
   V(AVXI8x16GeU)                   \
   V(IA32I8x16RoundingAverageU)     \
+  V(IA32I8x16Abs)                  \
   V(IA32S128Zero)                  \
   V(SSES128Not)                    \
   V(AVXS128Not)                    \
diff --git a/deps/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc b/deps/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
index 61c39a17e3..020136403a 100644
--- a/deps/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
+++ b/deps/v8/src/compiler/backend/ia32/instruction-scheduler-ia32.cc
@@ -171,10 +171,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kIA32I32x4SConvertI16x8Low:
     case kIA32I32x4SConvertI16x8High:
     case kIA32I32x4Neg:
-    case kSSEI32x4Shl:
-    case kAVXI32x4Shl:
-    case kSSEI32x4ShrS:
-    case kAVXI32x4ShrS:
+    case kIA32I32x4Shl:
+    case kIA32I32x4ShrS:
     case kSSEI32x4Add:
     case kAVXI32x4Add:
     case kSSEI32x4AddHoriz:
@@ -199,8 +197,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kAVXI32x4UConvertF32x4:
     case kIA32I32x4UConvertI16x8Low:
     case kIA32I32x4UConvertI16x8High:
-    case kSSEI32x4ShrU:
-    case kAVXI32x4ShrU:
+    case kIA32I32x4ShrU:
     case kSSEI32x4MinU:
     case kAVXI32x4MinU:
     case kSSEI32x4MaxU:
@@ -209,6 +206,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kAVXI32x4GtU:
     case kSSEI32x4GeU:
     case kAVXI32x4GeU:
+    case kIA32I32x4Abs:
     case kIA32I16x8Splat:
     case kIA32I16x8ExtractLaneU:
     case kIA32I16x8ExtractLaneS:
@@ -217,10 +215,8 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kIA32I16x8SConvertI8x16Low:
     case kIA32I16x8SConvertI8x16High:
     case kIA32I16x8Neg:
-    case kSSEI16x8Shl:
-    case kAVXI16x8Shl:
-    case kSSEI16x8ShrS:
-    case kAVXI16x8ShrS:
+    case kIA32I16x8Shl:
+    case kIA32I16x8ShrS:
     case kSSEI16x8SConvertI32x4:
     case kAVXI16x8SConvertI32x4:
     case kSSEI16x8Add:
@@ -249,8 +245,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kAVXI16x8GeS:
     case kIA32I16x8UConvertI8x16Low:
     case kIA32I16x8UConvertI8x16High:
-    case kSSEI16x8ShrU:
-    case kAVXI16x8ShrU:
+    case kIA32I16x8ShrU:
     case kSSEI16x8UConvertI32x4:
     case kAVXI16x8UConvertI32x4:
     case kSSEI16x8AddSaturateU:
@@ -266,6 +261,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kSSEI16x8GeU:
     case kAVXI16x8GeU:
     case kIA32I16x8RoundingAverageU:
+    case kIA32I16x8Abs:
     case kIA32I8x16Splat:
     case kIA32I8x16ExtractLaneU:
     case kIA32I8x16ExtractLaneS:
@@ -274,8 +270,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kSSEI8x16SConvertI16x8:
     case kAVXI8x16SConvertI16x8:
     case kIA32I8x16Neg:
-    case kSSEI8x16Shl:
-    case kAVXI8x16Shl:
+    case kIA32I8x16Shl:
     case kIA32I8x16ShrS:
     case kSSEI8x16Add:
     case kAVXI8x16Add:
@@ -315,6 +310,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kSSEI8x16GeU:
     case kAVXI8x16GeU:
     case kIA32I8x16RoundingAverageU:
+    case kIA32I8x16Abs:
     case kIA32S128Zero:
     case kSSES128Not:
     case kAVXS128Not:
diff --git a/deps/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc b/deps/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
index cb02f56e48..36a70c8fa8 100644
--- a/deps/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
+++ b/deps/v8/src/compiler/backend/ia32/instruction-selector-ia32.cc
@@ -305,22 +305,23 @@ void VisitRRISimd(InstructionSelector* selector, Node* node,
 }
 
 void VisitRROSimdShift(InstructionSelector* selector, Node* node,
-                       ArchOpcode avx_opcode, ArchOpcode sse_opcode) {
+                       ArchOpcode opcode) {
   IA32OperandGenerator g(selector);
-  InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
-  InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
-  InstructionOperand temps[] = {g.TempSimd128Register()};
-  if (selector->IsSupported(AVX)) {
-    selector->Emit(avx_opcode, g.DefineAsRegister(node), operand0, operand1,
-                   arraysize(temps), temps);
+  if (g.CanBeImmediate(node->InputAt(1))) {
+    selector->Emit(opcode, g.DefineSameAsFirst(node),
+                   g.UseRegister(node->InputAt(0)),
+                   g.UseImmediate(node->InputAt(1)));
   } else {
-    selector->Emit(sse_opcode, g.DefineSameAsFirst(node), operand0, operand1,
+    InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
+    InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
+    InstructionOperand temps[] = {g.TempSimd128Register()};
+    selector->Emit(opcode, g.DefineSameAsFirst(node), operand0, operand1,
                    arraysize(temps), temps);
   }
 }
 
-void VisitRROI8x16SimdRightShift(InstructionSelector* selector, Node* node,
-                                 ArchOpcode opcode) {
+void VisitRROI8x16SimdShift(InstructionSelector* selector, Node* node,
+                            ArchOpcode opcode) {
   IA32OperandGenerator g(selector);
   InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
   InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
@@ -328,7 +329,6 @@ void VisitRROI8x16SimdRightShift(InstructionSelector* selector, Node* node,
   selector->Emit(opcode, g.DefineSameAsFirst(node), operand0, operand1,
                  arraysize(temps), temps);
 }
-
 }  // namespace
 
 void InstructionSelector::VisitStackSlot(Node* node) {
@@ -1631,7 +1631,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   IA32OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -2004,21 +2004,22 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   InstructionCode code = kIA32Word32AtomicPairCompareExchange |
                          AddressingModeField::encode(addressing_mode);
 
+  InstructionOperand outputs[2];
+  size_t output_count = 0;
+  InstructionOperand temps[2];
+  size_t temp_count = 0;
+  if (projection0) {
+    outputs[output_count++] = g.DefineAsFixed(projection0, eax);
+  } else {
+    temps[temp_count++] = g.TempRegister(eax);
+  }
   if (projection1) {
-    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax),
-                                    g.DefineAsFixed(projection1, edx)};
-    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs, 0, {});
-  } else if (projection0) {
-    InstructionOperand outputs[] = {g.DefineAsFixed(projection0, eax)};
-    InstructionOperand temps[] = {g.TempRegister(edx)};
-    const int num_temps = arraysize(temps);
-    Emit(code, arraysize(outputs), outputs, arraysize(inputs), inputs,
-         num_temps, temps);
+    outputs[output_count++] = g.DefineAsFixed(projection1, edx);
   } else {
-    InstructionOperand temps[] = {g.TempRegister(eax), g.TempRegister(edx)};
-    const int num_temps = arraysize(temps);
-    Emit(code, 0, nullptr, arraysize(inputs), inputs, num_temps, temps);
+    temps[temp_count++] = g.TempRegister(edx);
   }
+  Emit(code, output_count, outputs, arraysize(inputs), inputs, temp_count,
+       temps);
 }
 
 #define SIMD_INT_TYPES(V) \
@@ -2107,12 +2108,15 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   V(I32x4Neg)               \
   V(I32x4UConvertI16x8Low)  \
   V(I32x4UConvertI16x8High) \
+  V(I32x4Abs)               \
   V(I16x8SConvertI8x16Low)  \
   V(I16x8SConvertI8x16High) \
   V(I16x8Neg)               \
   V(I16x8UConvertI8x16Low)  \
   V(I16x8UConvertI8x16High) \
-  V(I8x16Neg)
+  V(I16x8Abs)               \
+  V(I8x16Neg)               \
+  V(I8x16Abs)
 
 #define SIMD_UNOP_PREFIX_LIST(V) \
   V(F32x4Abs)                    \
@@ -2130,21 +2134,15 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
   V(S1x8AllTrue)             \
   V(S1x16AllTrue)
 
-#define SIMD_SHIFT_OPCODES(V) \
-  V(I32x4Shl)                 \
-  V(I32x4ShrS)                \
-  V(I32x4ShrU)                \
-  V(I16x8Shl)                 \
-  V(I16x8ShrS)                \
-  V(I16x8ShrU)
-
 #define SIMD_SHIFT_OPCODES_UNIFED_SSE_AVX(V) \
   V(I64x2Shl)                                \
-  V(I64x2ShrU)
-
-#define SIMD_I8X16_RIGHT_SHIFT_OPCODES(V) \
-  V(I8x16ShrS)                            \
-  V(I8x16ShrU)
+  V(I64x2ShrU)                               \
+  V(I32x4Shl)                                \
+  V(I32x4ShrS)                               \
+  V(I32x4ShrU)                               \
+  V(I16x8Shl)                                \
+  V(I16x8ShrS)                               \
+  V(I16x8ShrU)
 
 void InstructionSelector::VisitF64x2Min(Node* node) {
   IA32OperandGenerator g(this);
@@ -2360,30 +2358,14 @@ VISIT_SIMD_REPLACE_LANE(F32x4)
 VISIT_SIMD_REPLACE_LANE_USE_REG(F64x2)
 #undef VISIT_SIMD_REPLACE_LANE_USE_REG
 
-#define VISIT_SIMD_SHIFT(Opcode)                               \
-  void InstructionSelector::Visit##Opcode(Node* node) {        \
-    VisitRROSimdShift(this, node, kAVX##Opcode, kSSE##Opcode); \
-  }
-SIMD_SHIFT_OPCODES(VISIT_SIMD_SHIFT)
-#undef VISIT_SIMD_SHIFT
-#undef SIMD_SHIFT_OPCODES
-
-#define VISIT_SIMD_SHIFT_UNIFIED_SSE_AVX(Opcode)                 \
-  void InstructionSelector::Visit##Opcode(Node* node) {          \
-    VisitRROSimdShift(this, node, kIA32##Opcode, kIA32##Opcode); \
+#define VISIT_SIMD_SHIFT_UNIFIED_SSE_AVX(Opcode)        \
+  void InstructionSelector::Visit##Opcode(Node* node) { \
+    VisitRROSimdShift(this, node, kIA32##Opcode);       \
   }
 SIMD_SHIFT_OPCODES_UNIFED_SSE_AVX(VISIT_SIMD_SHIFT_UNIFIED_SSE_AVX)
 #undef VISIT_SIMD_SHIFT_UNIFIED_SSE_AVX
 #undef SIMD_SHIFT_OPCODES_UNIFED_SSE_AVX
 
-#define VISIT_SIMD_I8x16_RIGHT_SHIFT(Opcode)                \
-  void InstructionSelector::Visit##Opcode(Node* node) {     \
-    VisitRROI8x16SimdRightShift(this, node, kIA32##Opcode); \
-  }
-SIMD_I8X16_RIGHT_SHIFT_OPCODES(VISIT_SIMD_I8x16_RIGHT_SHIFT)
-#undef SIMD_I8X16_RIGHT_SHIFT_OPCODES
-#undef VISIT_SIMD_I8x16_RIGHT_SHIFT
-
 #define VISIT_SIMD_UNOP(Opcode)                                             \
   void InstructionSelector::Visit##Opcode(Node* node) {                     \
     IA32OperandGenerator g(this);                                           \
@@ -2463,15 +2445,36 @@ void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
 
 void InstructionSelector::VisitI8x16Shl(Node* node) {
   IA32OperandGenerator g(this);
-  InstructionOperand operand0 = g.UseUniqueRegister(node->InputAt(0));
-  InstructionOperand operand1 = g.UseUniqueRegister(node->InputAt(1));
-  InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()};
-  if (IsSupported(AVX)) {
-    Emit(kAVXI8x16Shl, g.DefineAsRegister(node), operand0, operand1,
-         arraysize(temps), temps);
+  if (g.CanBeImmediate(node->InputAt(1))) {
+    InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()};
+    this->Emit(kIA32I8x16Shl, g.DefineSameAsFirst(node),
+               g.UseRegister(node->InputAt(0)),
+               g.UseImmediate(node->InputAt(1)), arraysize(temps), temps);
   } else {
-    Emit(kSSEI8x16Shl, g.DefineSameAsFirst(node), operand0, operand1,
-         arraysize(temps), temps);
+    VisitRROI8x16SimdShift(this, node, kIA32I8x16Shl);
+  }
+}
+
+void InstructionSelector::VisitI8x16ShrS(Node* node) {
+  IA32OperandGenerator g(this);
+  if (g.CanBeImmediate(node->InputAt(1))) {
+    this->Emit(kIA32I8x16ShrS, g.DefineSameAsFirst(node),
+               g.UseRegister(node->InputAt(0)),
+               g.UseImmediate(node->InputAt(1)));
+  } else {
+    VisitRROI8x16SimdShift(this, node, kIA32I8x16ShrS);
+  }
+}
+
+void InstructionSelector::VisitI8x16ShrU(Node* node) {
+  IA32OperandGenerator g(this);
+  if (g.CanBeImmediate(node->InputAt(1))) {
+    InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()};
+    this->Emit(kIA32I8x16ShrU, g.DefineSameAsFirst(node),
+               g.UseRegister(node->InputAt(0)),
+               g.UseImmediate(node->InputAt(1)), arraysize(temps), temps);
+  } else {
+    VisitRROI8x16SimdShift(this, node, kIA32I8x16ShrU);
   }
 }
 
@@ -2700,7 +2703,10 @@ void InstructionSelector::VisitS8x16Shuffle(Node* node) {
         // pshufd takes a single imm8 shuffle mask.
         opcode = kIA32S32x4Swizzle;
         no_same_as_first = true;
-        src0_needs_reg = false;
+        // TODO(v8:9198): This doesn't strictly require a register, forcing the
+        // swizzles to always use registers until generation of incorrect memory
+        // operands can be fixed.
+        src0_needs_reg = true;
         imms[imm_count++] = shuffle_mask;
       }
     } else {
@@ -2713,7 +2719,11 @@ void InstructionSelector::VisitS8x16Shuffle(Node* node) {
       } else {
         opcode = kIA32S32x4Shuffle;
         no_same_as_first = true;
-        src0_needs_reg = false;
+        // TODO(v8:9198): src0 and src1 is used by pshufd in codegen, which
+        // requires memory to be 16-byte aligned, since we cannot guarantee that
+        // yet, force using a register here.
+        src0_needs_reg = true;
+        src1_needs_reg = true;
         imms[imm_count++] = shuffle_mask;
         int8_t blend_mask = PackBlend4(shuffle32x4);
         imms[imm_count++] = blend_mask;
diff --git a/deps/v8/src/compiler/backend/instruction-codes.h b/deps/v8/src/compiler/backend/instruction-codes.h
index 23e4e44b76..84d5d249b8 100644
--- a/deps/v8/src/compiler/backend/instruction-codes.h
+++ b/deps/v8/src/compiler/backend/instruction-codes.h
@@ -19,7 +19,7 @@
 #include "src/compiler/backend/mips64/instruction-codes-mips64.h"
 #elif V8_TARGET_ARCH_X64
 #include "src/compiler/backend/x64/instruction-codes-x64.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/compiler/backend/ppc/instruction-codes-ppc.h"
 #elif V8_TARGET_ARCH_S390
 #include "src/compiler/backend/s390/instruction-codes-s390.h"
@@ -82,7 +82,6 @@ inline RecordWriteMode WriteBarrierKindToRecordWriteMode(
   V(ArchCallBuiltinPointer)                                            \
   V(ArchJmp)                                                           \
   V(ArchBinarySearchSwitch)                                            \
-  V(ArchLookupSwitch)                                                  \
   V(ArchTableSwitch)                                                   \
   V(ArchNop)                                                           \
   V(ArchAbortCSAAssert)                                                \
diff --git a/deps/v8/src/compiler/backend/instruction-scheduler.cc b/deps/v8/src/compiler/backend/instruction-scheduler.cc
index dd4bca4d81..4f26130d66 100644
--- a/deps/v8/src/compiler/backend/instruction-scheduler.cc
+++ b/deps/v8/src/compiler/backend/instruction-scheduler.cc
@@ -263,7 +263,6 @@ int InstructionScheduler::GetInstructionFlags(const Instruction* instr) const {
     case kArchDeoptimize:
     case kArchJmp:
     case kArchBinarySearchSwitch:
-    case kArchLookupSwitch:
     case kArchRet:
     case kArchTableSwitch:
     case kArchThrowTerminator:
diff --git a/deps/v8/src/compiler/backend/instruction-selector-impl.h b/deps/v8/src/compiler/backend/instruction-selector-impl.h
index 7569d1280a..aa7da85e42 100644
--- a/deps/v8/src/compiler/backend/instruction-selector-impl.h
+++ b/deps/v8/src/compiler/backend/instruction-selector-impl.h
@@ -11,6 +11,7 @@
 #include "src/compiler/common-operator.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/schedule.h"
+#include "src/objects/tagged-index.h"
 
 namespace v8 {
 namespace internal {
@@ -46,12 +47,6 @@ class SwitchInfo {
     }
   }
 
-  // Ensure that comparison order of if-cascades is preserved.
-  std::vector<CaseInfo> CasesSortedByOriginalOrder() const {
-    std::vector<CaseInfo> result(cases_.begin(), cases_.end());
-    std::stable_sort(result.begin(), result.end());
-    return result;
-  }
   std::vector<CaseInfo> CasesSortedByValue() const {
     std::vector<CaseInfo> result(cases_.begin(), cases_.end());
     std::stable_sort(result.begin(), result.end(),
@@ -314,6 +309,19 @@ class OperandGenerator {
         return Constant(OpParameter<int32_t>(node->op()));
       case IrOpcode::kInt64Constant:
         return Constant(OpParameter<int64_t>(node->op()));
+      case IrOpcode::kTaggedIndexConstant: {
+        // Unencoded index value.
+        intptr_t value =
+            static_cast<intptr_t>(OpParameter<int32_t>(node->op()));
+        DCHECK(TaggedIndex::IsValid(value));
+        // Generate it as 32/64-bit constant in a tagged form.
+        Address tagged_index = TaggedIndex::FromIntptr(value).ptr();
+        if (kSystemPointerSize == kInt32Size) {
+          return Constant(static_cast<int32_t>(tagged_index));
+        } else {
+          return Constant(static_cast<int64_t>(tagged_index));
+        }
+      }
       case IrOpcode::kFloat32Constant:
         return Constant(OpParameter<float>(node->op()));
       case IrOpcode::kRelocatableInt32Constant:
diff --git a/deps/v8/src/compiler/backend/instruction-selector.cc b/deps/v8/src/compiler/backend/instruction-selector.cc
index 6c6db9f6d7..7d72dbbf2d 100644
--- a/deps/v8/src/compiler/backend/instruction-selector.cc
+++ b/deps/v8/src/compiler/backend/instruction-selector.cc
@@ -574,11 +574,7 @@ size_t InstructionSelector::AddOperandToStateValueDescriptor(
     StateValueList* values, InstructionOperandVector* inputs,
     OperandGenerator* g, StateObjectDeduplicator* deduplicator, Node* input,
     MachineType type, FrameStateInputKind kind, Zone* zone) {
-  if (input == nullptr) {
-    values->PushOptimizedOut();
-    return 0;
-  }
-
+  DCHECK_NOT_NULL(input);
   switch (input->opcode()) {
     case IrOpcode::kArgumentsElementsState: {
       values->PushArgumentsElements(ArgumentsStateTypeOf(input->op()));
@@ -636,6 +632,26 @@ size_t InstructionSelector::AddOperandToStateValueDescriptor(
   }
 }
 
+size_t InstructionSelector::AddInputsToFrameStateDescriptor(
+    StateValueList* values, InstructionOperandVector* inputs,
+    OperandGenerator* g, StateObjectDeduplicator* deduplicator, Node* node,
+    FrameStateInputKind kind, Zone* zone) {
+  size_t entries = 0;
+  StateValuesAccess::iterator it = StateValuesAccess(node).begin();
+  // Take advantage of sparse nature of StateValuesAccess to skip over multiple
+  // empty nodes at once pushing repeated OptimizedOuts all in one go.
+  while (!it.done()) {
+    values->PushOptimizedOut(it.AdvanceTillNotEmpty());
+    if (it.done()) break;
+    StateValuesAccess::TypedNode input_node = *it;
+    entries += AddOperandToStateValueDescriptor(values, inputs, g, deduplicator,
+                                                input_node.node,
+                                                input_node.type, kind, zone);
+    ++it;
+  }
+  return entries;
+}
+
 // Returns the number of instruction operands added to inputs.
 size_t InstructionSelector::AddInputsToFrameStateDescriptor(
     FrameStateDescriptor* descriptor, Node* state, OperandGenerator* g,
@@ -669,30 +685,25 @@ size_t InstructionSelector::AddInputsToFrameStateDescriptor(
   DCHECK_EQ(values_descriptor->size(), 0u);
   values_descriptor->ReserveSize(descriptor->GetSize());
 
+  DCHECK_NOT_NULL(function);
   entries += AddOperandToStateValueDescriptor(
       values_descriptor, inputs, g, deduplicator, function,
       MachineType::AnyTagged(), FrameStateInputKind::kStackSlot, zone);
-  for (StateValuesAccess::TypedNode input_node :
-       StateValuesAccess(parameters)) {
-    entries += AddOperandToStateValueDescriptor(values_descriptor, inputs, g,
-                                                deduplicator, input_node.node,
-                                                input_node.type, kind, zone);
-  }
+
+  entries += AddInputsToFrameStateDescriptor(
+      values_descriptor, inputs, g, deduplicator, parameters, kind, zone);
+
   if (descriptor->HasContext()) {
+    DCHECK_NOT_NULL(context);
     entries += AddOperandToStateValueDescriptor(
         values_descriptor, inputs, g, deduplicator, context,
         MachineType::AnyTagged(), FrameStateInputKind::kStackSlot, zone);
   }
-  for (StateValuesAccess::TypedNode input_node : StateValuesAccess(locals)) {
-    entries += AddOperandToStateValueDescriptor(values_descriptor, inputs, g,
-                                                deduplicator, input_node.node,
-                                                input_node.type, kind, zone);
-  }
-  for (StateValuesAccess::TypedNode input_node : StateValuesAccess(stack)) {
-    entries += AddOperandToStateValueDescriptor(values_descriptor, inputs, g,
-                                                deduplicator, input_node.node,
-                                                input_node.type, kind, zone);
-  }
+
+  entries += AddInputsToFrameStateDescriptor(values_descriptor, inputs, g,
+                                             deduplicator, locals, kind, zone);
+  entries += AddInputsToFrameStateDescriptor(values_descriptor, inputs, g,
+                                             deduplicator, stack, kind, zone);
   DCHECK_EQ(initial_size + entries, inputs->size());
   return entries;
 }
@@ -798,21 +809,6 @@ void InstructionSelector::AppendDeoptimizeArguments(
                                   instruction_zone());
 }
 
-Instruction* InstructionSelector::EmitDeoptimize(
-    InstructionCode opcode, size_t output_count, InstructionOperand* outputs,
-    size_t input_count, InstructionOperand* inputs, DeoptimizeKind kind,
-    DeoptimizeReason reason, FeedbackSource const& feedback,
-    Node* frame_state) {
-  InstructionOperandVector args(instruction_zone());
-  for (size_t i = 0; i < input_count; ++i) {
-    args.push_back(inputs[i]);
-  }
-  opcode |= MiscField::encode(static_cast<int>(input_count));
-  AppendDeoptimizeArguments(&args, kind, reason, feedback, frame_state);
-  return Emit(opcode, output_count, outputs, args.size(), &args.front(), 0,
-              nullptr);
-}
-
 // An internal helper class for generating the operands to calls.
 // TODO(bmeurer): Get rid of the CallBuffer business and make
 // InstructionSelector::VisitCall platform independent instead.
@@ -1335,6 +1331,7 @@ void InstructionSelector::VisitNode(Node* node) {
       return VisitProjection(node);
     case IrOpcode::kInt32Constant:
     case IrOpcode::kInt64Constant:
+    case IrOpcode::kTaggedIndexConstant:
     case IrOpcode::kExternalConstant:
     case IrOpcode::kRelocatableInt32Constant:
     case IrOpcode::kRelocatableInt64Constant:
@@ -2026,6 +2023,10 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsSimd128(node), VisitI32x4GtU(node);
     case IrOpcode::kI32x4GeU:
       return MarkAsSimd128(node), VisitI32x4GeU(node);
+    case IrOpcode::kI32x4Abs:
+      return MarkAsSimd128(node), VisitI32x4Abs(node);
+    case IrOpcode::kI32x4BitMask:
+      return MarkAsWord32(node), VisitI32x4BitMask(node);
     case IrOpcode::kI16x8Splat:
       return MarkAsSimd128(node), VisitI16x8Splat(node);
     case IrOpcode::kI16x8ExtractLaneU:
@@ -2092,6 +2093,10 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsSimd128(node), VisitI16x8GeU(node);
     case IrOpcode::kI16x8RoundingAverageU:
       return MarkAsSimd128(node), VisitI16x8RoundingAverageU(node);
+    case IrOpcode::kI16x8Abs:
+      return MarkAsSimd128(node), VisitI16x8Abs(node);
+    case IrOpcode::kI16x8BitMask:
+      return MarkAsWord32(node), VisitI16x8BitMask(node);
     case IrOpcode::kI8x16Splat:
       return MarkAsSimd128(node), VisitI8x16Splat(node);
     case IrOpcode::kI8x16ExtractLaneU:
@@ -2148,6 +2153,10 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsSimd128(node), VisitI8x16GeU(node);
     case IrOpcode::kI8x16RoundingAverageU:
       return MarkAsSimd128(node), VisitI8x16RoundingAverageU(node);
+    case IrOpcode::kI8x16Abs:
+      return MarkAsSimd128(node), VisitI8x16Abs(node);
+    case IrOpcode::kI8x16BitMask:
+      return MarkAsWord32(node), VisitI8x16BitMask(node);
     case IrOpcode::kS128Zero:
       return MarkAsSimd128(node), VisitS128Zero(node);
     case IrOpcode::kS128And:
@@ -2336,23 +2345,6 @@ void InstructionSelector::EmitTableSwitch(
   Emit(kArchTableSwitch, 0, nullptr, input_count, inputs, 0, nullptr);
 }
 
-void InstructionSelector::EmitLookupSwitch(
-    const SwitchInfo& sw, InstructionOperand const& value_operand) {
-  OperandGenerator g(this);
-  std::vector<CaseInfo> cases = sw.CasesSortedByOriginalOrder();
-  size_t input_count = 2 + sw.case_count() * 2;
-  DCHECK_LE(sw.case_count(), (std::numeric_limits<size_t>::max() - 2) / 2);
-  auto* inputs = zone()->NewArray<InstructionOperand>(input_count);
-  inputs[0] = value_operand;
-  inputs[1] = g.Label(sw.default_branch());
-  for (size_t index = 0; index < cases.size(); ++index) {
-    const CaseInfo& c = cases[index];
-    inputs[index * 2 + 2 + 0] = g.TempImmediate(c.value);
-    inputs[index * 2 + 2 + 1] = g.Label(c.branch);
-  }
-  Emit(kArchLookupSwitch, 0, nullptr, input_count, inputs, 0, nullptr);
-}
-
 void InstructionSelector::EmitBinarySearchSwitch(
     const SwitchInfo& sw, InstructionOperand const& value_operand) {
   OperandGenerator g(this);
@@ -2362,8 +2354,6 @@ void InstructionSelector::EmitBinarySearchSwitch(
   inputs[0] = value_operand;
   inputs[1] = g.Label(sw.default_branch());
   std::vector<CaseInfo> cases = sw.CasesSortedByValue();
-  std::stable_sort(cases.begin(), cases.end(),
-                   [](CaseInfo a, CaseInfo b) { return a.value < b.value; });
   for (size_t index = 0; index < cases.size(); ++index) {
     const CaseInfo& c = cases[index];
     inputs[index * 2 + 2 + 0] = g.TempImmediate(c.value);
@@ -2583,7 +2573,7 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
 #endif  // !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_MIPS
 
 #if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS64 && \
-    !V8_TARGET_ARCH_S390 && !V8_TARGET_ARCH_PPC
+    !V8_TARGET_ARCH_S390 && !V8_TARGET_ARCH_PPC64
 void InstructionSelector::VisitWord64AtomicLoad(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitWord64AtomicStore(Node* node) {
@@ -2607,7 +2597,7 @@ void InstructionSelector::VisitWord64AtomicExchange(Node* node) {
 void InstructionSelector::VisitWord64AtomicCompareExchange(Node* node) {
   UNIMPLEMENTED();
 }
-#endif  // !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_PPC
+#endif  // !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_PPC64
         // !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_S390
 
 #if !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM
@@ -2620,7 +2610,7 @@ void InstructionSelector::VisitI64x2ReplaceLaneI32Pair(Node* node) {
 }
 #endif  // !V8_TARGET_ARCH_IA32
 
-#if !V8_TARGET_ARCH_X64
+#if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_S390X
 #if !V8_TARGET_ARCH_ARM64
 void InstructionSelector::VisitI64x2Splat(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI64x2ExtractLane(Node* node) { UNIMPLEMENTED(); }
@@ -2642,7 +2632,13 @@ void InstructionSelector::VisitI64x2MinS(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI64x2MaxS(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI64x2MinU(Node* node) { UNIMPLEMENTED(); }
 void InstructionSelector::VisitI64x2MaxU(Node* node) { UNIMPLEMENTED(); }
-#endif  // !V8_TARGET_ARCH_X64
+#endif  // !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_S390X
+
+#if !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_ARM
+void InstructionSelector::VisitI8x16BitMask(Node* node) { UNIMPLEMENTED(); }
+void InstructionSelector::VisitI16x8BitMask(Node* node) { UNIMPLEMENTED(); }
+void InstructionSelector::VisitI32x4BitMask(Node* node) { UNIMPLEMENTED(); }
+#endif  // !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_ARM
 
 void InstructionSelector::VisitFinishRegion(Node* node) { EmitIdentity(node); }
 
@@ -2990,9 +2986,10 @@ void InstructionSelector::EmitIdentity(Node* node) {
 void InstructionSelector::VisitDeoptimize(DeoptimizeKind kind,
                                           DeoptimizeReason reason,
                                           FeedbackSource const& feedback,
-                                          Node* value) {
-  EmitDeoptimize(kArchDeoptimize, 0, nullptr, 0, nullptr, kind, reason,
-                 feedback, value);
+                                          Node* frame_state) {
+  InstructionOperandVector args(instruction_zone());
+  AppendDeoptimizeArguments(&args, kind, reason, feedback, frame_state);
+  Emit(kArchDeoptimize, 0, nullptr, args.size(), &args.front(), 0, nullptr);
 }
 
 void InstructionSelector::VisitThrow(Node* node) {
@@ -3055,17 +3052,10 @@ namespace {
 FrameStateDescriptor* GetFrameStateDescriptorInternal(Zone* zone, Node* state) {
   DCHECK_EQ(IrOpcode::kFrameState, state->opcode());
   DCHECK_EQ(kFrameStateInputCount, state->InputCount());
-  FrameStateInfo state_info = FrameStateInfoOf(state->op());
-
-  int parameters = static_cast<int>(
-      StateValuesAccess(state->InputAt(kFrameStateParametersInput)).size());
-  int locals = static_cast<int>(
-      StateValuesAccess(state->InputAt(kFrameStateLocalsInput)).size());
-  int stack = static_cast<int>(
-      StateValuesAccess(state->InputAt(kFrameStateStackInput)).size());
-
-  DCHECK_EQ(parameters, state_info.parameter_count());
-  DCHECK_EQ(locals, state_info.local_count());
+  const FrameStateInfo& state_info = FrameStateInfoOf(state->op());
+  int parameters = state_info.parameter_count();
+  int locals = state_info.local_count();
+  int stack = state_info.type() == FrameStateType::kInterpretedFunction ? 1 : 0;
 
   FrameStateDescriptor* outer_state = nullptr;
   Node* outer_node = state->InputAt(kFrameStateOuterStateInput);
@@ -3242,7 +3232,6 @@ bool InstructionSelector::NeedsPoisoning(IsSafetyCheck safety_check) const {
   }
   UNREACHABLE();
 }
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler/backend/instruction-selector.h b/deps/v8/src/compiler/backend/instruction-selector.h
index a142993ef2..5950591286 100644
--- a/deps/v8/src/compiler/backend/instruction-selector.h
+++ b/deps/v8/src/compiler/backend/instruction-selector.h
@@ -351,15 +351,7 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
       size_t input_count, InstructionOperand* inputs, size_t temp_count,
       InstructionOperand* temps, FlagsContinuation* cont);
 
-  // ===========================================================================
-  // ===== Architecture-independent deoptimization exit emission methods. ======
-  // ===========================================================================
-  Instruction* EmitDeoptimize(InstructionCode opcode, size_t output_count,
-                              InstructionOperand* outputs, size_t input_count,
-                              InstructionOperand* inputs, DeoptimizeKind kind,
-                              DeoptimizeReason reason,
-                              FeedbackSource const& feedback,
-                              Node* frame_state);
+  void EmitIdentity(Node* node);
 
   // ===========================================================================
   // ============== Architecture-independent CPU feature methods. ==============
@@ -508,8 +500,6 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
 
   void EmitTableSwitch(const SwitchInfo& sw,
                        InstructionOperand const& index_operand);
-  void EmitLookupSwitch(const SwitchInfo& sw,
-                        InstructionOperand const& value_operand);
   void EmitBinarySearchSwitch(const SwitchInfo& sw,
                               InstructionOperand const& value_operand);
 
@@ -586,6 +576,12 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
                                          StateObjectDeduplicator* deduplicator,
                                          InstructionOperandVector* inputs,
                                          FrameStateInputKind kind, Zone* zone);
+  size_t AddInputsToFrameStateDescriptor(StateValueList* values,
+                                         InstructionOperandVector* inputs,
+                                         OperandGenerator* g,
+                                         StateObjectDeduplicator* deduplicator,
+                                         Node* node, FrameStateInputKind kind,
+                                         Zone* zone);
   size_t AddOperandToStateValueDescriptor(StateValueList* values,
                                           InstructionOperandVector* inputs,
                                           OperandGenerator* g,
@@ -636,7 +632,7 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
   void VisitBranch(Node* input, BasicBlock* tbranch, BasicBlock* fbranch);
   void VisitSwitch(Node* node, const SwitchInfo& sw);
   void VisitDeoptimize(DeoptimizeKind kind, DeoptimizeReason reason,
-                       FeedbackSource const& feedback, Node* value);
+                       FeedbackSource const& feedback, Node* frame_state);
   void VisitReturn(Node* ret);
   void VisitThrow(Node* node);
   void VisitRetain(Node* node);
@@ -655,7 +651,6 @@ class V8_EXPORT_PRIVATE InstructionSelector final {
   void EmitPrepareResults(ZoneVector<compiler::PushParameter>* results,
                           const CallDescriptor* call_descriptor, Node* node);
 
-  void EmitIdentity(Node* node);
   bool CanProduceSignalingNaN(Node* node);
 
   // ===========================================================================
diff --git a/deps/v8/src/compiler/backend/instruction.h b/deps/v8/src/compiler/backend/instruction.h
index 92fa95270c..e189100c34 100644
--- a/deps/v8/src/compiler/backend/instruction.h
+++ b/deps/v8/src/compiler/backend/instruction.h
@@ -1212,8 +1212,8 @@ class StateValueList {
   void PushPlain(MachineType type) {
     fields_.push_back(StateValueDescriptor::Plain(type));
   }
-  void PushOptimizedOut() {
-    fields_.push_back(StateValueDescriptor::OptimizedOut());
+  void PushOptimizedOut(size_t num = 1) {
+    fields_.insert(fields_.end(), num, StateValueDescriptor::OptimizedOut());
   }
 
   iterator begin() { return iterator(fields_.begin(), nested_.begin()); }
@@ -1362,6 +1362,8 @@ class V8_EXPORT_PRIVATE InstructionBlock final
 
   bool IsDeferred() const { return deferred_; }
   bool IsHandler() const { return handler_; }
+  void MarkHandler() { handler_ = true; }
+  void UnmarkHandler() { handler_ = false; }
 
   RpoNumber ao_number() const { return ao_number_; }
   RpoNumber rpo_number() const { return rpo_number_; }
@@ -1416,7 +1418,7 @@ class V8_EXPORT_PRIVATE InstructionBlock final
   int32_t code_start_;   // start index of arch-specific code.
   int32_t code_end_ = -1;     // end index of arch-specific code.
   const bool deferred_;       // Block contains deferred code.
-  const bool handler_;   // Block is a handler entry point.
+  bool handler_;              // Block is a handler entry point.
   bool switch_target_ = false;
   bool alignment_ = false;  // insert alignment before this block
   bool needs_frame_ = false;
diff --git a/deps/v8/src/compiler/backend/jump-threading.cc b/deps/v8/src/compiler/backend/jump-threading.cc
index ee195bf51e..488a13c1a9 100644
--- a/deps/v8/src/compiler/backend/jump-threading.cc
+++ b/deps/v8/src/compiler/backend/jump-threading.cc
@@ -165,8 +165,19 @@ void JumpThreading::ApplyForwarding(Zone* local_zone,
   // Skip empty blocks when the previous block doesn't fall through.
   bool prev_fallthru = true;
   for (auto const block : code->instruction_blocks()) {
-    int block_num = block->rpo_number().ToInt();
-    skip[block_num] = !prev_fallthru && result[block_num].ToInt() != block_num;
+    RpoNumber block_rpo = block->rpo_number();
+    int block_num = block_rpo.ToInt();
+    RpoNumber result_rpo = result[block_num];
+    skip[block_num] = !prev_fallthru && result_rpo != block_rpo;
+
+    if (result_rpo != block_rpo) {
+      // We need the handler information to be propagated, so that branch
+      // targets are annotated as necessary for control flow integrity
+      // checks (when enabled).
+      if (code->InstructionBlockAt(block_rpo)->IsHandler()) {
+        code->InstructionBlockAt(result_rpo)->MarkHandler();
+      }
+    }
 
     bool fallthru = true;
     for (int i = block->code_start(); i < block->code_end(); ++i) {
@@ -179,6 +190,8 @@ void JumpThreading::ApplyForwarding(Zone* local_zone,
           // Overwrite a redundant jump with a nop.
           TRACE("jt-fw nop @%d\n", i);
           instr->OverwriteWithNop();
+          // If this block was marked as a handler, it can be unmarked now.
+          code->InstructionBlockAt(block_rpo)->UnmarkHandler();
         }
         fallthru = false;  // jumps don't fall through to the next block.
       }
diff --git a/deps/v8/src/compiler/backend/mips/code-generator-mips.cc b/deps/v8/src/compiler/backend/mips/code-generator-mips.cc
index dd35d47dc4..8e1ce0f2a3 100644
--- a/deps/v8/src/compiler/backend/mips/code-generator-mips.cc
+++ b/deps/v8/src/compiler/backend/mips/code-generator-mips.cc
@@ -787,7 +787,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       bool isWasmCapiFunction =
           linkage()->GetIncomingDescriptor()->IsWasmCapiFunction();
       // from start_call to return address.
-      int offset = 40;
+      int offset = __ root_array_available() ? 68 : 80;
 #if V8_HOST_ARCH_MIPS
       if (__ emit_debug_code()) {
         offset += 16;
@@ -840,9 +840,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
@@ -859,7 +856,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ stop();
       break;
     case kArchDebugBreak:
-      __ stop();
+      __ DebugBreak();
       break;
     case kArchComment:
       __ RecordComment(reinterpret_cast<const char*>(i.InputInt32(0)));
@@ -2439,6 +2436,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                  i.InputSimd128Register(0));
       break;
     }
+    case kMipsI32x4Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_w(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMipsI16x8Splat: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ fill_h(i.OutputSimd128Register(), i.InputRegister(0));
@@ -2600,6 +2603,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                   i.InputSimd128Register(0));
       break;
     }
+    case kMipsI16x8Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_h(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMipsI8x16Splat: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ fill_b(i.OutputSimd128Register(), i.InputRegister(0));
@@ -2761,6 +2770,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                   i.InputSimd128Register(0));
       break;
     }
+    case kMipsI8x16Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_b(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMipsS128And: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ and_v(i.OutputSimd128Register(), i.InputSimd128Register(0),
@@ -3681,16 +3696,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  MipsOperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ li(kScratchReg, Operand(i.InputInt32(index + 0)));
-    __ Branch(GetLabel(i.InputRpo(index + 1)), eq, input, Operand(kScratchReg));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   MipsOperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -3747,7 +3752,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ Push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
diff --git a/deps/v8/src/compiler/backend/mips/instruction-codes-mips.h b/deps/v8/src/compiler/backend/mips/instruction-codes-mips.h
index c3458e7b91..0a37dd7068 100644
--- a/deps/v8/src/compiler/backend/mips/instruction-codes-mips.h
+++ b/deps/v8/src/compiler/backend/mips/instruction-codes-mips.h
@@ -203,6 +203,7 @@ namespace compiler {
   V(MipsI32x4GeS)                  \
   V(MipsI32x4GtU)                  \
   V(MipsI32x4GeU)                  \
+  V(MipsI32x4Abs)                  \
   V(MipsI16x8Splat)                \
   V(MipsI16x8ExtractLaneU)         \
   V(MipsI16x8ExtractLaneS)         \
@@ -230,6 +231,7 @@ namespace compiler {
   V(MipsI16x8GtU)                  \
   V(MipsI16x8GeU)                  \
   V(MipsI16x8RoundingAverageU)     \
+  V(MipsI16x8Abs)                  \
   V(MipsI8x16Splat)                \
   V(MipsI8x16ExtractLaneU)         \
   V(MipsI8x16ExtractLaneS)         \
@@ -256,6 +258,7 @@ namespace compiler {
   V(MipsI8x16GtU)                  \
   V(MipsI8x16GeU)                  \
   V(MipsI8x16RoundingAverageU)     \
+  V(MipsI8x16Abs)                  \
   V(MipsS128And)                   \
   V(MipsS128Or)                    \
   V(MipsS128Xor)                   \
diff --git a/deps/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc b/deps/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
index c6a7f6b95a..81bbfbbfb9 100644
--- a/deps/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
+++ b/deps/v8/src/compiler/backend/mips/instruction-scheduler-mips.cc
@@ -137,6 +137,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMipsI16x8UConvertI32x4:
     case kMipsI16x8UConvertI8x16High:
     case kMipsI16x8UConvertI8x16Low:
+    case kMipsI16x8Abs:
     case kMipsI32x4Add:
     case kMipsI32x4AddHoriz:
     case kMipsI32x4Eq:
@@ -164,6 +165,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMipsI32x4UConvertF32x4:
     case kMipsI32x4UConvertI16x8High:
     case kMipsI32x4UConvertI16x8Low:
+    case kMipsI32x4Abs:
     case kMipsI8x16Add:
     case kMipsI8x16AddSaturateS:
     case kMipsI8x16AddSaturateU:
@@ -192,6 +194,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMipsI8x16SubSaturateS:
     case kMipsI8x16SubSaturateU:
     case kMipsI8x16UConvertI16x8:
+    case kMipsI8x16Abs:
     case kMipsIns:
     case kMipsLsa:
     case kMipsMaddD:
@@ -1295,13 +1298,9 @@ int AssembleArchJumpLatency() {
   return Latency::BRANCH;
 }
 
-int AssembleArchLookupSwitchLatency(int cases) {
-  return cases * (1 + Latency::BRANCH) + AssembleArchJumpLatency();
-}
-
 int AssembleArchBinarySearchSwitchLatency(int cases) {
   if (cases < CodeGenerator::kBinarySearchSwitchMinimalCases) {
-    return AssembleArchLookupSwitchLatency(cases);
+    return cases * (1 + Latency::BRANCH) + AssembleArchJumpLatency();
   }
   return 1 + Latency::BRANCH + AssembleArchBinarySearchSwitchLatency(cases / 2);
 }
@@ -1390,8 +1389,6 @@ int InstructionScheduler::GetInstructionLatency(const Instruction* instr) {
     case kArchBinarySearchSwitch:
       return AssembleArchBinarySearchSwitchLatency((instr->InputCount() - 2) /
                                                    2);
-    case kArchLookupSwitch:
-      return AssembleArchLookupSwitchLatency((instr->InputCount() - 2) / 2);
     case kArchTableSwitch:
       return AssembleArchTableSwitchLatency();
     case kArchAbortCSAAssert:
diff --git a/deps/v8/src/compiler/backend/mips/instruction-selector-mips.cc b/deps/v8/src/compiler/backend/mips/instruction-selector-mips.cc
index 22f8217e4d..cd87f36913 100644
--- a/deps/v8/src/compiler/backend/mips/instruction-selector-mips.cc
+++ b/deps/v8/src/compiler/backend/mips/instruction-selector-mips.cc
@@ -1708,7 +1708,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   MipsOperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 9 + sw.value_range();
@@ -2169,6 +2169,7 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I32x4GeS, kMipsI32x4GeS)                           \
   V(I32x4GtU, kMipsI32x4GtU)                           \
   V(I32x4GeU, kMipsI32x4GeU)                           \
+  V(I32x4Abs, kMipsI32x4Abs)                           \
   V(I16x8Add, kMipsI16x8Add)                           \
   V(I16x8AddSaturateS, kMipsI16x8AddSaturateS)         \
   V(I16x8AddSaturateU, kMipsI16x8AddSaturateU)         \
@@ -2190,6 +2191,7 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I16x8SConvertI32x4, kMipsI16x8SConvertI32x4)       \
   V(I16x8UConvertI32x4, kMipsI16x8UConvertI32x4)       \
   V(I16x8RoundingAverageU, kMipsI16x8RoundingAverageU) \
+  V(I16x8Abs, kMipsI16x8Abs)                           \
   V(I8x16Add, kMipsI8x16Add)                           \
   V(I8x16AddSaturateS, kMipsI8x16AddSaturateS)         \
   V(I8x16AddSaturateU, kMipsI8x16AddSaturateU)         \
@@ -2210,6 +2212,7 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I8x16RoundingAverageU, kMipsI8x16RoundingAverageU) \
   V(I8x16SConvertI16x8, kMipsI8x16SConvertI16x8)       \
   V(I8x16UConvertI16x8, kMipsI8x16UConvertI16x8)       \
+  V(I8x16Abs, kMipsI8x16Abs)                           \
   V(S128And, kMipsS128And)                             \
   V(S128Or, kMipsS128Or)                               \
   V(S128Xor, kMipsS128Xor)                             \
diff --git a/deps/v8/src/compiler/backend/mips64/code-generator-mips64.cc b/deps/v8/src/compiler/backend/mips64/code-generator-mips64.cc
index 1e36c6ed92..224b23fffc 100644
--- a/deps/v8/src/compiler/backend/mips64/code-generator-mips64.cc
+++ b/deps/v8/src/compiler/backend/mips64/code-generator-mips64.cc
@@ -765,7 +765,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       bool isWasmCapiFunction =
           linkage()->GetIncomingDescriptor()->IsWasmCapiFunction();
       // from start_call to return address.
-      int offset = 48;
+      int offset = __ root_array_available() ? 76 : 88;
 #if V8_HOST_ARCH_MIPS64
       if (__ emit_debug_code()) {
         offset += 16;
@@ -818,8 +818,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
       break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
@@ -837,7 +835,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ stop();
       break;
     case kArchDebugBreak:
-      __ stop();
+      __ DebugBreak();
       break;
     case kArchComment:
       __ RecordComment(reinterpret_cast<const char*>(i.InputInt64(0)));
@@ -2492,6 +2490,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                  i.InputSimd128Register(0));
       break;
     }
+    case kMips64I32x4Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_w(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMips64I16x8Splat: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ fill_h(i.OutputSimd128Register(), i.InputRegister(0));
@@ -2653,6 +2657,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                   i.InputSimd128Register(0));
       break;
     }
+    case kMips64I16x8Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_h(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMips64I8x16Splat: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ fill_b(i.OutputSimd128Register(), i.InputRegister(0));
@@ -2814,6 +2824,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                   i.InputSimd128Register(0));
       break;
     }
+    case kMips64I8x16Abs: {
+      CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
+      __ asub_s_b(i.OutputSimd128Register(), i.InputSimd128Register(0),
+                  kSimd128RegZero);
+      break;
+    }
     case kMips64S128And: {
       CpuFeatureScope msa_scope(tasm(), MIPS_SIMD);
       __ and_v(i.OutputSimd128Register(), i.InputSimd128Register(0),
@@ -3780,16 +3796,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  MipsOperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ li(kScratchReg, Operand(i.InputInt32(index + 0)));
-    __ Branch(GetLabel(i.InputRpo(index + 1)), eq, input, Operand(kScratchReg));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   MipsOperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -3844,7 +3850,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ Push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
diff --git a/deps/v8/src/compiler/backend/mips64/instruction-codes-mips64.h b/deps/v8/src/compiler/backend/mips64/instruction-codes-mips64.h
index bed1080cbe..c752381c8c 100644
--- a/deps/v8/src/compiler/backend/mips64/instruction-codes-mips64.h
+++ b/deps/v8/src/compiler/backend/mips64/instruction-codes-mips64.h
@@ -233,6 +233,7 @@ namespace compiler {
   V(Mips64I32x4GeS)                          \
   V(Mips64I32x4GtU)                          \
   V(Mips64I32x4GeU)                          \
+  V(Mips64I32x4Abs)                          \
   V(Mips64I16x8Splat)                        \
   V(Mips64I16x8ExtractLaneU)                 \
   V(Mips64I16x8ExtractLaneS)                 \
@@ -260,6 +261,7 @@ namespace compiler {
   V(Mips64I16x8GtU)                          \
   V(Mips64I16x8GeU)                          \
   V(Mips64I16x8RoundingAverageU)             \
+  V(Mips64I16x8Abs)                          \
   V(Mips64I8x16Splat)                        \
   V(Mips64I8x16ExtractLaneU)                 \
   V(Mips64I8x16ExtractLaneS)                 \
@@ -286,6 +288,7 @@ namespace compiler {
   V(Mips64I8x16GtU)                          \
   V(Mips64I8x16GeU)                          \
   V(Mips64I8x16RoundingAverageU)             \
+  V(Mips64I8x16Abs)                          \
   V(Mips64S128And)                           \
   V(Mips64S128Or)                            \
   V(Mips64S128Xor)                           \
diff --git a/deps/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc b/deps/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
index ff6517be00..0261d915fb 100644
--- a/deps/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
+++ b/deps/v8/src/compiler/backend/mips64/instruction-scheduler-mips64.cc
@@ -167,6 +167,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMips64I16x8UConvertI8x16High:
     case kMips64I16x8UConvertI8x16Low:
     case kMips64I16x8RoundingAverageU:
+    case kMips64I16x8Abs:
     case kMips64I32x4Add:
     case kMips64I32x4AddHoriz:
     case kMips64I32x4Eq:
@@ -194,6 +195,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMips64I32x4UConvertF32x4:
     case kMips64I32x4UConvertI16x8High:
     case kMips64I32x4UConvertI16x8Low:
+    case kMips64I32x4Abs:
     case kMips64I8x16Add:
     case kMips64I8x16AddSaturateS:
     case kMips64I8x16AddSaturateU:
@@ -220,6 +222,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kMips64I8x16SubSaturateS:
     case kMips64I8x16SubSaturateU:
     case kMips64I8x16RoundingAverageU:
+    case kMips64I8x16Abs:
     case kMips64Ins:
     case kMips64Lsa:
     case kMips64MaxD:
@@ -945,14 +948,6 @@ int AssembleArchJumpLatency() {
   return Latency::BRANCH;
 }
 
-int AssembleArchLookupSwitchLatency(const Instruction* instr) {
-  int latency = 0;
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    latency += 1 + Latency::BRANCH;
-  }
-  return latency + AssembleArchJumpLatency();
-}
-
 int GenerateSwitchTableLatency() {
   int latency = 0;
   if (kArchVariant >= kMips64r6) {
@@ -1301,8 +1296,6 @@ int InstructionScheduler::GetInstructionLatency(const Instruction* instr) {
       return CallCFunctionLatency();
     case kArchJmp:
       return AssembleArchJumpLatency();
-    case kArchLookupSwitch:
-      return AssembleArchLookupSwitchLatency(instr);
     case kArchTableSwitch:
       return AssembleArchTableSwitchLatency();
     case kArchAbortCSAAssert:
diff --git a/deps/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc b/deps/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
index 12a12e456c..5a0e41ccbe 100644
--- a/deps/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
+++ b/deps/v8/src/compiler/backend/mips64/instruction-selector-mips64.cc
@@ -2290,7 +2290,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   Mips64OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 10 + 2 * sw.value_range();
@@ -2757,12 +2757,15 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(I32x4SConvertI16x8High, kMips64I32x4SConvertI16x8High) \
   V(I32x4UConvertI16x8Low, kMips64I32x4UConvertI16x8Low)   \
   V(I32x4UConvertI16x8High, kMips64I32x4UConvertI16x8High) \
+  V(I32x4Abs, kMips64I32x4Abs)                             \
   V(I16x8Neg, kMips64I16x8Neg)                             \
   V(I16x8SConvertI8x16Low, kMips64I16x8SConvertI8x16Low)   \
   V(I16x8SConvertI8x16High, kMips64I16x8SConvertI8x16High) \
   V(I16x8UConvertI8x16Low, kMips64I16x8UConvertI8x16Low)   \
   V(I16x8UConvertI8x16High, kMips64I16x8UConvertI8x16High) \
+  V(I16x8Abs, kMips64I16x8Abs)                             \
   V(I8x16Neg, kMips64I8x16Neg)                             \
+  V(I8x16Abs, kMips64I8x16Abs)                             \
   V(S128Not, kMips64S128Not)                               \
   V(S1x4AnyTrue, kMips64S1x4AnyTrue)                       \
   V(S1x4AllTrue, kMips64S1x4AllTrue)                       \
diff --git a/deps/v8/src/compiler/backend/ppc/code-generator-ppc.cc b/deps/v8/src/compiler/backend/ppc/code-generator-ppc.cc
index c43295f03f..addbd76ffb 100644
--- a/deps/v8/src/compiler/backend/ppc/code-generator-ppc.cc
+++ b/deps/v8/src/compiler/backend/ppc/code-generator-ppc.cc
@@ -1031,7 +1031,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Label start_call;
       bool isWasmCapiFunction =
           linkage()->GetIncomingDescriptor()->IsWasmCapiFunction();
-      int offset = 9 * kInstrSize;
+      int offset = 20 * kInstrSize;
 #if defined(_AIX)
       // AIX/PPC64BE Linux uses a function descriptor
       int kNumParametersMask = kHasFunctionDescriptorBitMask - 1;
@@ -1041,7 +1041,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // AIX may emit 2 extra Load instructions under CallCFunctionHelper
       // due to having function descriptor.
       if (has_function_descriptor) {
-        offset = 11 * kInstrSize;
+        offset = 22 * kInstrSize;
       }
 #endif
       if (isWasmCapiFunction) {
@@ -1096,10 +1096,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      DCHECK_EQ(LeaveRC, i.OutputRCBit());
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
@@ -1117,7 +1113,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ stop();
       break;
     case kArchDebugBreak:
-      __ stop();
+      __ DebugBreak();
       break;
     case kArchNop:
     case kArchThrowTerminator:
@@ -2315,16 +2311,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  PPCOperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ Cmpwi(input, Operand(i.InputInt32(index + 0)), r0);
-    __ beq(GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   PPCOperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -2401,7 +2387,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ Push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
diff --git a/deps/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc b/deps/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
index a7b4e3e870..7e29b00c31 100644
--- a/deps/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
+++ b/deps/v8/src/compiler/backend/ppc/instruction-selector-ppc.cc
@@ -1658,7 +1658,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   PPCOperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -2457,6 +2457,12 @@ void InstructionSelector::VisitF64x2Max(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitLoadTransform(Node* node) { UNIMPLEMENTED(); }
 
+void InstructionSelector::VisitI8x16Abs(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitI16x8Abs(Node* node) { UNIMPLEMENTED(); }
+
+void InstructionSelector::VisitI32x4Abs(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/deps/v8/src/compiler/backend/register-allocator.cc b/deps/v8/src/compiler/backend/register-allocator.cc
index f37faf850d..9420269ca0 100644
--- a/deps/v8/src/compiler/backend/register-allocator.cc
+++ b/deps/v8/src/compiler/backend/register-allocator.cc
@@ -2808,9 +2808,9 @@ bool LiveRangeBundle::TryMerge(LiveRangeBundle* other, bool trace_alloc) {
   auto iter2 = other->uses_.begin();
 
   while (iter1 != uses_.end() && iter2 != other->uses_.end()) {
-    if (iter1->start > iter2->end) {
+    if (iter1->start >= iter2->end) {
       ++iter2;
-    } else if (iter2->start > iter1->end) {
+    } else if (iter2->start >= iter1->end) {
       ++iter1;
     } else {
       TRACE_COND(trace_alloc, "No merge %d:%d %d:%d\n", iter1->start,
@@ -3016,13 +3016,14 @@ LifetimePosition RegisterAllocator::FindOptimalSpillingPos(
         LiveRange* check_use = live_at_header;
         for (; check_use != nullptr && check_use->Start() < pos;
              check_use = check_use->next()) {
-          UsePosition* next_use =
-              check_use->NextUsePositionRegisterIsBeneficial(loop_start);
-          if (next_use != nullptr && next_use->pos() < pos) {
+          UsePosition* next_use = check_use->NextRegisterPosition(loop_start);
+          // UsePosition at the end of a UseInterval may
+          // have the same value as the start of next range.
+          if (next_use != nullptr && next_use->pos() <= pos) {
             return pos;
           }
         }
-        // No register beneficial use inside the loop before the pos.
+        // No register use inside the loop before the pos.
         *begin_spill_out = live_at_header;
         pos = loop_start;
         break;
@@ -4323,6 +4324,10 @@ void LinearScanAllocator::AllocateBlockedReg(LiveRange* current,
   if (register_use == nullptr) {
     // There is no use in the current live range that requires a register.
     // We can just spill it.
+    LiveRange* begin_spill = nullptr;
+    LifetimePosition spill_pos = FindOptimalSpillingPos(
+        current, current->Start(), spill_mode, &begin_spill);
+    MaybeSpillPreviousRanges(begin_spill, spill_pos, current);
     Spill(current, spill_mode);
     return;
   }
diff --git a/deps/v8/src/compiler/backend/register-allocator.h b/deps/v8/src/compiler/backend/register-allocator.h
index 6c943dbe68..9e1a7beff9 100644
--- a/deps/v8/src/compiler/backend/register-allocator.h
+++ b/deps/v8/src/compiler/backend/register-allocator.h
@@ -721,6 +721,7 @@ class LiveRangeBundle : public ZoneObject {
  private:
   friend class BundleBuilder;
 
+  // Representation of the non-empty interval [start,end[.
   class Range {
    public:
     Range(int s, int e) : start(s), end(e) {}
diff --git a/deps/v8/src/compiler/backend/s390/code-generator-s390.cc b/deps/v8/src/compiler/backend/s390/code-generator-s390.cc
index 5b7d0adb09..24552cf632 100644
--- a/deps/v8/src/compiler/backend/s390/code-generator-s390.cc
+++ b/deps/v8/src/compiler/backend/s390/code-generator-s390.cc
@@ -204,6 +204,9 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     if (mode_ > RecordWriteMode::kValueIsPointer) {
       __ JumpIfSmi(value_, exit());
     }
+    if (COMPRESS_POINTERS_BOOL) {
+      __ DecompressTaggedPointer(value_, value_);
+    }
     __ CheckPageFlag(value_, scratch0_,
                      MemoryChunk::kPointersToHereAreInterestingMask, eq,
                      exit());
@@ -1330,7 +1333,8 @@ void CodeGenerator::BailoutIfDeoptimized() {
   }
 
   int offset = Code::kCodeDataContainerOffset - Code::kHeaderSize;
-  __ LoadP(ip, MemOperand(kJavaScriptCallCodeStartRegister, offset));
+  __ LoadTaggedPointerField(
+      ip, MemOperand(kJavaScriptCallCodeStartRegister, offset), r0);
   __ LoadW(ip,
            FieldMemOperand(ip, CodeDataContainer::kKindSpecificFlagsOffset));
   __ TestBit(ip, Code::kMarkedForDeoptimizationBit);
@@ -1467,13 +1471,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Register func = i.InputRegister(0);
       if (FLAG_debug_code) {
         // Check the function's context matches the context argument.
-        __ LoadP(kScratchReg,
-                 FieldMemOperand(func, JSFunction::kContextOffset));
+        __ LoadTaggedPointerField(
+            kScratchReg, FieldMemOperand(func, JSFunction::kContextOffset));
         __ CmpP(cp, kScratchReg);
         __ Assert(eq, AbortReason::kWrongFunctionContext);
       }
       static_assert(kJavaScriptCallCodeStartRegister == r4, "ABI mismatch");
-      __ LoadP(r4, FieldMemOperand(func, JSFunction::kCodeOffset));
+      __ LoadTaggedPointerField(r4,
+                                FieldMemOperand(func, JSFunction::kCodeOffset));
       __ CallCodeObject(r4);
       RecordCallPosition(instr);
       frame_access_state()->ClearSPDelta();
@@ -1559,9 +1564,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
@@ -1578,7 +1580,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ stop();
       break;
     case kArchDebugBreak:
-      __ stop();
+      __ DebugBreak();
       break;
     case kArchNop:
     case kArchThrowTerminator:
@@ -1646,14 +1648,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         ool = new (zone()) OutOfLineRecordWrite(
             this, object, offset, value, scratch0, scratch1, mode,
             DetermineStubCallMode(), &unwinding_info_writer_);
-        __ StoreP(value, MemOperand(object, offset));
+        __ StoreTaggedField(value, MemOperand(object, offset), r0);
       } else {
         DCHECK_EQ(kMode_MRR, addressing_mode);
         Register offset(i.InputRegister(1));
         ool = new (zone()) OutOfLineRecordWrite(
             this, object, offset, value, scratch0, scratch1, mode,
             DetermineStubCallMode(), &unwinding_info_writer_);
-        __ StoreP(value, MemOperand(object, offset));
+        __ StoreTaggedField(value, MemOperand(object, offset));
       }
       __ CheckPageFlag(object, scratch0,
                        MemoryChunk::kPointersFromHereAreInterestingMask, ne,
@@ -2246,16 +2248,28 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kS390_Push:
       if (instr->InputAt(0)->IsFPRegister()) {
         LocationOperand* op = LocationOperand::cast(instr->InputAt(0));
-        if (op->representation() == MachineRepresentation::kFloat64) {
-          __ lay(sp, MemOperand(sp, -kDoubleSize));
-          __ StoreDouble(i.InputDoubleRegister(0), MemOperand(sp));
-          frame_access_state()->IncreaseSPDelta(kDoubleSize /
-                                                kSystemPointerSize);
-        } else {
-          DCHECK_EQ(MachineRepresentation::kFloat32, op->representation());
-          __ lay(sp, MemOperand(sp, -kSystemPointerSize));
-          __ StoreFloat32(i.InputDoubleRegister(0), MemOperand(sp));
-          frame_access_state()->IncreaseSPDelta(1);
+        switch (op->representation()) {
+          case MachineRepresentation::kFloat32:
+            __ lay(sp, MemOperand(sp, -kSystemPointerSize));
+            __ StoreFloat32(i.InputDoubleRegister(0), MemOperand(sp));
+            break;
+          case MachineRepresentation::kFloat64:
+            __ lay(sp, MemOperand(sp, -kDoubleSize));
+            __ StoreDouble(i.InputDoubleRegister(0), MemOperand(sp));
+            frame_access_state()->IncreaseSPDelta(kDoubleSize /
+                                                  kSystemPointerSize);
+            break;
+          case MachineRepresentation::kSimd128: {
+            __ lay(sp, MemOperand(sp, -kSimd128Size));
+            __ StoreSimd128(i.InputDoubleRegister(0), MemOperand(sp),
+                            kScratchReg);
+            frame_access_state()->IncreaseSPDelta(kSimd128Size /
+                                                  kSystemPointerSize);
+            break;
+          }
+          default:
+            UNREACHABLE();
+            break;
         }
       } else {
         __ Push(i.InputRegister(0));
@@ -2285,10 +2299,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
         if (op->representation() == MachineRepresentation::kFloat64) {
           __ StoreDouble(i.InputDoubleRegister(0),
                          MemOperand(sp, slot * kSystemPointerSize));
-        } else {
-          DCHECK_EQ(MachineRepresentation::kFloat32, op->representation());
+        } else if (op->representation() == MachineRepresentation::kFloat32) {
           __ StoreFloat32(i.InputDoubleRegister(0),
                           MemOperand(sp, slot * kSystemPointerSize));
+        } else {
+          DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
+          __ StoreSimd128(i.InputDoubleRegister(0),
+                          MemOperand(sp, slot * kSystemPointerSize),
+                          kScratchReg);
         }
       } else {
         __ StoreP(i.InputRegister(0),
@@ -2887,6 +2905,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       ASSEMBLE_ATOMIC64_COMP_EXCHANGE_WORD64();
       break;
       // vector replicate element
+    case kS390_F64x2Splat: {
+      __ vrep(i.OutputSimd128Register(), i.InputDoubleRegister(0), Operand(0),
+              Condition(3));
+      break;
+    }
     case kS390_F32x4Splat: {
 #ifdef V8_TARGET_BIG_ENDIAN
       __ vrep(i.OutputSimd128Register(), i.InputDoubleRegister(0), Operand(0),
@@ -2897,6 +2920,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #endif
       break;
     }
+    case kS390_I64x2Splat: {
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vlvg(dst, i.InputRegister(0), MemOperand(r0, 0), Condition(3));
+      __ vrep(dst, dst, Operand(0), Condition(3));
+      break;
+    }
     case kS390_I32x4Splat: {
       Simd128Register dst = i.OutputSimd128Register();
       __ vlvg(dst, i.InputRegister(0), MemOperand(r0, 0), Condition(2));
@@ -2916,47 +2945,136 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     // vector extract element
+    case kS390_F64x2ExtractLane: {
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vrep(i.OutputDoubleRegister(), i.InputSimd128Register(0),
+              Operand(1 - i.InputInt8(1)), Condition(3));
+#else
+      __ vrep(i.OutputDoubleRegister(), i.InputSimd128Register(0),
+              Operand(i.InputInt8(1)), Condition(3));
+#endif
+      break;
+    }
     case kS390_F32x4ExtractLane: {
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vrep(i.OutputDoubleRegister(), i.InputSimd128Register(0),
               Operand(3 - i.InputInt8(1)), Condition(2));
+#else
+      __ vrep(i.OutputDoubleRegister(), i.InputSimd128Register(0),
+              Operand(i.InputInt8(1)), Condition(2));
+#endif
+      break;
+    }
+    case kS390_I64x2ExtractLane: {
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+              MemOperand(r0, 1 - i.InputInt8(1)), Condition(3));
+#else
+      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(3));
+#endif
       break;
     }
     case kS390_I32x4ExtractLane: {
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
               MemOperand(r0, 3 - i.InputInt8(1)), Condition(2));
+#else
+      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(2));
+#endif
       break;
     }
     case kS390_I16x8ExtractLaneU: {
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
               MemOperand(r0, 7 - i.InputInt8(1)), Condition(1));
+#else
+      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(1));
+#endif
       break;
     }
     case kS390_I16x8ExtractLaneS: {
-      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlgv(kScratchReg, i.InputSimd128Register(0),
               MemOperand(r0, 7 - i.InputInt8(1)), Condition(1));
+#else
+      __ vlgv(kScratchReg, i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(1));
+#endif
+      __ lghr(i.OutputRegister(), kScratchReg);
       break;
     }
     case kS390_I8x16ExtractLaneU: {
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
               MemOperand(r0, 15 - i.InputInt8(1)), Condition(0));
+#else
+      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(0));
+#endif
       break;
     }
     case kS390_I8x16ExtractLaneS: {
-      __ vlgv(i.OutputRegister(), i.InputSimd128Register(0),
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlgv(kScratchReg, i.InputSimd128Register(0),
               MemOperand(r0, 15 - i.InputInt8(1)), Condition(0));
+#else
+      __ vlgv(kScratchReg, i.InputSimd128Register(0),
+              MemOperand(r0, i.InputInt8(1)), Condition(0));
+#endif
+      __ lgbr(i.OutputRegister(), kScratchReg);
       break;
     }
     // vector replace element
+    case kS390_F64x2ReplaceLane: {
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vlr(kScratchDoubleReg, src, Condition(0), Condition(0), Condition(0));
+      __ vlgv(kScratchReg, i.InputDoubleRegister(2), MemOperand(r0, 0),
+              Condition(3));
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlvg(kScratchDoubleReg, kScratchReg,
+              MemOperand(r0, 1 - i.InputInt8(1)), Condition(3));
+#else
+      __ vlvg(kScratchDoubleReg, kScratchReg, MemOperand(r0, i.InputInt8(1)),
+              Condition(3));
+#endif
+      __ vlr(dst, kScratchDoubleReg, Condition(0), Condition(0), Condition(0));
+      break;
+    }
     case kS390_F32x4ReplaceLane: {
       Simd128Register src = i.InputSimd128Register(0);
       Simd128Register dst = i.OutputSimd128Register();
+      __ vlr(kScratchDoubleReg, src, Condition(0), Condition(0), Condition(0));
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlgv(kScratchReg, i.InputDoubleRegister(2), MemOperand(r0, 0),
+              Condition(2));
+      __ vlvg(kScratchDoubleReg, kScratchReg,
+              MemOperand(r0, 3 - i.InputInt8(1)), Condition(2));
+#else
+      __ vlgv(kScratchReg, i.InputDoubleRegister(2), MemOperand(r0, 1),
+              Condition(2));
+      __ vlvg(kScratchDoubleReg, kScratchReg, MemOperand(r0, i.InputInt8(1)),
+              Condition(2));
+#endif
+      __ vlr(dst, kScratchDoubleReg, Condition(0), Condition(0), Condition(0));
+      break;
+    }
+    case kS390_I64x2ReplaceLane: {
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register dst = i.OutputSimd128Register();
       if (src != dst) {
         __ vlr(dst, src, Condition(0), Condition(0), Condition(0));
       }
-      __ lgdr(kScratchReg, i.InputDoubleRegister(2));
-      __ srlg(kScratchReg, kScratchReg, Operand(32));
-      __ vlvg(i.OutputSimd128Register(), kScratchReg,
-              MemOperand(r0, 3 - i.InputInt8(1)), Condition(2));
+#ifdef V8_TARGET_BIG_ENDIAN
+      __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
+              MemOperand(r0, 1 - i.InputInt8(1)), Condition(3));
+#else
+      __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
+              MemOperand(r0, i.InputInt8(1)), Condition(3));
+#endif
       break;
     }
     case kS390_I32x4ReplaceLane: {
@@ -2965,8 +3083,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       if (src != dst) {
         __ vlr(dst, src, Condition(0), Condition(0), Condition(0));
       }
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
               MemOperand(r0, 3 - i.InputInt8(1)), Condition(2));
+#else
+      __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
+              MemOperand(r0, i.InputInt8(1)), Condition(2));
+#endif
       break;
     }
     case kS390_I16x8ReplaceLane: {
@@ -2975,8 +3098,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       if (src != dst) {
         __ vlr(dst, src, Condition(0), Condition(0), Condition(0));
       }
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
               MemOperand(r0, 7 - i.InputInt8(1)), Condition(1));
+#else
+      __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
+              MemOperand(r0, i.InputInt8(1)), Condition(1));
+#endif
       break;
     }
     case kS390_I8x16ReplaceLane: {
@@ -2985,17 +3113,81 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       if (src != dst) {
         __ vlr(dst, src, Condition(0), Condition(0), Condition(0));
       }
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
               MemOperand(r0, 15 - i.InputInt8(1)), Condition(0));
+#else
+      __ vlvg(i.OutputSimd128Register(), i.InputRegister(2),
+              MemOperand(r0, i.InputInt8(1)), Condition(0));
+#endif
       break;
     }
     // vector binops
+    case kS390_F64x2Add: {
+      __ vfa(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
+    case kS390_F64x2Sub: {
+      __ vfs(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
+    case kS390_F64x2Mul: {
+      __ vfm(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
+    case kS390_F64x2Div: {
+      __ vfd(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
+    case kS390_F64x2Min: {
+      __ vfmin(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(1), Condition(0),
+               Condition(3));
+      break;
+    }
+    case kS390_F64x2Max: {
+      __ vfmax(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(1), Condition(0),
+               Condition(3));
+      break;
+    }
+    case kS390_F64x2Qfma: {
+      Simd128Register src0 = i.InputSimd128Register(0);
+      Simd128Register src1 = i.InputSimd128Register(1);
+      Simd128Register src2 = i.InputSimd128Register(2);
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vfma(dst, src1, src2, src0, Condition(3), Condition(0));
+      break;
+    }
+    case kS390_F64x2Qfms: {
+      Simd128Register src0 = i.InputSimd128Register(0);
+      Simd128Register src1 = i.InputSimd128Register(1);
+      Simd128Register src2 = i.InputSimd128Register(2);
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vfnms(dst, src1, src2, src0, Condition(3), Condition(0));
+      break;
+    }
     case kS390_F32x4Add: {
       __ vfa(i.OutputSimd128Register(), i.InputSimd128Register(0),
              i.InputSimd128Register(1), Condition(0), Condition(0),
              Condition(2));
       break;
     }
+#define FLOAT_ADD_HORIZ(src0, src1, scratch0, scratch1, add0, add1)         \
+  __ vpk(dst, src0, src1, Condition(0), Condition(0), Condition(3));        \
+  __ vesrl(scratch0, src0, MemOperand(r0, shift_bits), Condition(3));       \
+  __ vesrl(scratch1, src1, MemOperand(r0, shift_bits), Condition(3));       \
+  __ vpk(kScratchDoubleReg, scratch0, scratch1, Condition(0), Condition(0), \
+         Condition(3));                                                     \
+  __ vfa(dst, add0, add1, Condition(0), Condition(0), Condition(2));
     case kS390_F32x4AddHoriz: {
       Simd128Register src0 = i.InputSimd128Register(0);
       Simd128Register src1 = i.InputSimd128Register(1);
@@ -3003,16 +3195,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       DoubleRegister tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
       DoubleRegister tempFPReg2 = i.ToSimd128Register(instr->TempAt(1));
       constexpr int shift_bits = 32;
-      // generate first operand
-      __ vpk(dst, src1, src0, Condition(0), Condition(0), Condition(3));
-      // generate second operand
-      __ vesrl(tempFPReg1, src0, MemOperand(r0, shift_bits), Condition(3));
-      __ vesrl(tempFPReg2, src1, MemOperand(r0, shift_bits), Condition(3));
-      __ vpk(kScratchDoubleReg, tempFPReg2, tempFPReg1, Condition(0),
-             Condition(0), Condition(3));
-      // add the operands
-      __ vfa(dst, kScratchDoubleReg, dst, Condition(0), Condition(0),
-             Condition(2));
+#ifdef V8_TARGET_BIG_ENDIAN
+      FLOAT_ADD_HORIZ(src1, src0, tempFPReg2, tempFPReg1, kScratchDoubleReg,
+                      dst)
+#else
+      FLOAT_ADD_HORIZ(src0, src1, tempFPReg1, tempFPReg2, dst,
+                      kScratchDoubleReg)
+#endif
+#undef FLOAT_ADD_HORIZ
       break;
     }
     case kS390_F32x4Sub: {
@@ -3027,6 +3217,67 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
              Condition(2));
       break;
     }
+    case kS390_F32x4Div: {
+      __ vfd(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(2));
+      break;
+    }
+    case kS390_F32x4Min: {
+      __ vfmin(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(1), Condition(0),
+               Condition(2));
+      break;
+    }
+    case kS390_F32x4Max: {
+      __ vfmax(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(1), Condition(0),
+               Condition(2));
+      break;
+    }
+    case kS390_F32x4Qfma: {
+      Simd128Register src0 = i.InputSimd128Register(0);
+      Simd128Register src1 = i.InputSimd128Register(1);
+      Simd128Register src2 = i.InputSimd128Register(2);
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vfma(dst, src1, src2, src0, Condition(2), Condition(0));
+      break;
+    }
+    case kS390_F32x4Qfms: {
+      Simd128Register src0 = i.InputSimd128Register(0);
+      Simd128Register src1 = i.InputSimd128Register(1);
+      Simd128Register src2 = i.InputSimd128Register(2);
+      Simd128Register dst = i.OutputSimd128Register();
+      __ vfnms(dst, src1, src2, src0, Condition(2), Condition(0));
+      break;
+    }
+    case kS390_I64x2Add: {
+      __ va(i.OutputSimd128Register(), i.InputSimd128Register(0),
+            i.InputSimd128Register(1), Condition(0), Condition(0),
+            Condition(3));
+      break;
+    }
+    case kS390_I64x2Sub: {
+      __ vs(i.OutputSimd128Register(), i.InputSimd128Register(0),
+            i.InputSimd128Register(1), Condition(0), Condition(0),
+            Condition(3));
+      break;
+    }
+    case kS390_I64x2Mul: {
+      Simd128Register src0 = i.InputSimd128Register(0);
+      Simd128Register src1 = i.InputSimd128Register(1);
+      Register scratch_0 = r0;
+      Register scratch_1 = r1;
+      for (int i = 0; i < 2; i++) {
+        __ vlgv(scratch_0, src0, MemOperand(r0, 0), Condition(3));
+        __ vlgv(scratch_1, src1, MemOperand(r0, 0), Condition(3));
+        __ Mul64(scratch_0, scratch_1);
+        scratch_0 = r1;
+        scratch_1 = ip;
+      }
+      __ vlvgp(i.OutputSimd128Register(), r0, r1);
+      break;
+    }
     case kS390_I32x4Add: {
       __ va(i.OutputSimd128Register(), i.InputSimd128Register(0),
             i.InputSimd128Register(1), Condition(0), Condition(0),
@@ -3043,8 +3294,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                Condition(2));
       __ vsumg(kScratchDoubleReg, src1, kScratchDoubleReg, Condition(0),
                Condition(0), Condition(2));
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vpk(dst, kScratchDoubleReg, dst, Condition(0), Condition(0),
              Condition(3));
+#else
+      __ vpk(dst, dst, kScratchDoubleReg, Condition(0), Condition(0),
+             Condition(3));
+#endif
       break;
     }
     case kS390_I32x4Sub: {
@@ -3075,8 +3331,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
               Condition(1));
       __ vsum(kScratchDoubleReg, src1, kScratchDoubleReg, Condition(0),
               Condition(0), Condition(1));
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vpk(dst, kScratchDoubleReg, dst, Condition(0), Condition(0),
              Condition(2));
+#else
+      __ vpk(dst, dst, kScratchDoubleReg, Condition(0), Condition(0),
+             Condition(2));
+#endif
       break;
     }
     case kS390_I16x8Sub: {
@@ -3109,13 +3370,63 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
              Condition(0));
       break;
     }
+    case kS390_I16x8RoundingAverageU: {
+      __ vavgl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(0), Condition(0),
+               Condition(1));
+      break;
+    }
+    case kS390_I8x16RoundingAverageU: {
+      __ vavgl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               i.InputSimd128Register(1), Condition(0), Condition(0),
+               Condition(0));
+      break;
+    }
     // vector comparisons
+    case kS390_F64x2Eq: {
+      __ vfce(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(0),
+              Condition(3));
+      break;
+    }
+    case kS390_F64x2Ne: {
+      __ vfce(kScratchDoubleReg, i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(0),
+              Condition(3));
+      __ vno(i.OutputSimd128Register(), kScratchDoubleReg, kScratchDoubleReg,
+             Condition(0), Condition(0), Condition(3));
+      break;
+    }
+    case kS390_F64x2Le: {
+      __ vfche(i.OutputSimd128Register(), i.InputSimd128Register(1),
+               i.InputSimd128Register(0), Condition(0), Condition(0),
+               Condition(3));
+      break;
+    }
+    case kS390_F64x2Lt: {
+      __ vfch(i.OutputSimd128Register(), i.InputSimd128Register(1),
+              i.InputSimd128Register(0), Condition(0), Condition(0),
+              Condition(3));
+      break;
+    }
+    case kS390_I64x2MinS: {
+      __ vmn(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
     case kS390_I32x4MinS: {
       __ vmn(i.OutputSimd128Register(), i.InputSimd128Register(0),
              i.InputSimd128Register(1), Condition(0), Condition(0),
              Condition(2));
       break;
     }
+    case kS390_I64x2MinU: {
+      __ vmnl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(0),
+              Condition(3));
+      break;
+    }
     case kS390_I32x4MinU: {
       __ vmnl(i.OutputSimd128Register(), i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(0),
@@ -3146,12 +3457,24 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
               Condition(0));
       break;
     }
+    case kS390_I64x2MaxS: {
+      __ vmx(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(0),
+             Condition(3));
+      break;
+    }
     case kS390_I32x4MaxS: {
       __ vmx(i.OutputSimd128Register(), i.InputSimd128Register(0),
              i.InputSimd128Register(1), Condition(0), Condition(0),
              Condition(2));
       break;
     }
+    case kS390_I64x2MaxU: {
+      __ vmxl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(0),
+              Condition(3));
+      break;
+    }
     case kS390_I32x4MaxU: {
       __ vmxl(i.OutputSimd128Register(), i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(0),
@@ -3188,6 +3511,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
               Condition(2));
       break;
     }
+    case kS390_I64x2Eq: {
+      __ vceq(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4Eq: {
       __ vceq(i.OutputSimd128Register(), i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(2));
@@ -3204,12 +3532,19 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kS390_F32x4Ne: {
-      __ vfce(i.OutputSimd128Register(), i.InputSimd128Register(0),
+      __ vfce(kScratchDoubleReg, i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(0),
               Condition(2));
+      __ vno(i.OutputSimd128Register(), kScratchDoubleReg, kScratchDoubleReg,
+             Condition(0), Condition(0), Condition(2));
+      break;
+    }
+    case kS390_I64x2Ne: {
+      __ vceq(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
       __ vno(i.OutputSimd128Register(), i.OutputSimd128Register(),
              i.OutputSimd128Register(), Condition(0), Condition(0),
-             Condition(2));
+             Condition(3));
       break;
     }
     case kS390_I32x4Ne: {
@@ -3248,11 +3583,25 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                Condition(2));
       break;
     }
+    case kS390_I64x2GtS: {
+      __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4GtS: {
       __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
              i.InputSimd128Register(1), Condition(0), Condition(2));
       break;
     }
+    case kS390_I64x2GeS: {
+      __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
+      __ vch(i.OutputSimd128Register(), i.InputSimd128Register(0),
+             i.InputSimd128Register(1), Condition(0), Condition(3));
+      __ vo(i.OutputSimd128Register(), i.OutputSimd128Register(),
+            kScratchDoubleReg, Condition(0), Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4GeS: {
       __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(2));
@@ -3262,11 +3611,25 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
             kScratchDoubleReg, Condition(0), Condition(0), Condition(2));
       break;
     }
+    case kS390_I64x2GtU: {
+      __ vchl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4GtU: {
       __ vchl(i.OutputSimd128Register(), i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(2));
       break;
     }
+    case kS390_I64x2GeU: {
+      __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
+      __ vchl(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(3));
+      __ vo(i.OutputSimd128Register(), i.OutputSimd128Register(),
+            kScratchDoubleReg, Condition(0), Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4GeU: {
       __ vceq(kScratchDoubleReg, i.InputSimd128Register(0),
               i.InputSimd128Register(1), Condition(0), Condition(2));
@@ -3342,6 +3705,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     __ op(i.OutputSimd128Register(), i.InputSimd128Register(0),            \
           kScratchDoubleReg, Condition(0), Condition(0), Condition(mode)); \
   }
+    case kS390_I64x2Shl: {
+      VECTOR_SHIFT(veslv, 3);
+      break;
+    }
+    case kS390_I64x2ShrS: {
+      VECTOR_SHIFT(vesrav, 3);
+      break;
+    }
+    case kS390_I64x2ShrU: {
+      VECTOR_SHIFT(vesrlv, 3);
+      break;
+    }
     case kS390_I32x4Shl: {
       VECTOR_SHIFT(veslv, 2);
       break;
@@ -3379,6 +3754,21 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     // vector unary ops
+    case kS390_F64x2Abs: {
+      __ vfpso(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               Condition(2), Condition(0), Condition(3));
+      break;
+    }
+    case kS390_F64x2Neg: {
+      __ vfpso(i.OutputSimd128Register(), i.InputSimd128Register(0),
+               Condition(0), Condition(0), Condition(3));
+      break;
+    }
+    case kS390_F64x2Sqrt: {
+      __ vfsq(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              Condition(0), Condition(0), Condition(3));
+      break;
+    }
     case kS390_F32x4Abs: {
       __ vfpso(i.OutputSimd128Register(), i.InputSimd128Register(0),
                Condition(2), Condition(0), Condition(2));
@@ -3389,6 +3779,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
                Condition(0), Condition(0), Condition(2));
       break;
     }
+    case kS390_I64x2Neg: {
+      __ vlc(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0),
+             Condition(0), Condition(3));
+      break;
+    }
     case kS390_I32x4Neg: {
       __ vlc(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0),
              Condition(0), Condition(2));
@@ -3407,7 +3802,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kS390_F32x4RecipApprox: {
       __ lgfi(kScratchReg, Operand(1));
       __ ConvertIntToFloat(kScratchDoubleReg, kScratchReg);
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vrep(kScratchDoubleReg, kScratchDoubleReg, Operand(0), Condition(2));
+#else
+      __ vrep(kScratchDoubleReg, kScratchDoubleReg, Operand(1), Condition(2));
+#endif
       __ vfd(i.OutputSimd128Register(), kScratchDoubleReg,
              i.InputSimd128Register(0), Condition(0), Condition(0),
              Condition(2));
@@ -3419,18 +3818,43 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
               Condition(2));
       __ lgfi(kScratchReg, Operand(1));
       __ ConvertIntToFloat(kScratchDoubleReg, kScratchReg);
+#ifdef V8_TARGET_BIG_ENDIAN
       __ vrep(kScratchDoubleReg, kScratchDoubleReg, Operand(0), Condition(2));
+#else
+      __ vrep(kScratchDoubleReg, kScratchDoubleReg, Operand(1), Condition(2));
+#endif
       __ vfd(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
              Condition(0), Condition(0), Condition(2));
       break;
     }
+    case kS390_F32x4Sqrt: {
+      __ vfsq(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              Condition(0), Condition(0), Condition(2));
+      break;
+    }
     case kS390_S128Not: {
       Simd128Register src = i.InputSimd128Register(0);
       Simd128Register dst = i.OutputSimd128Register();
       __ vno(dst, src, src, Condition(0), Condition(0), Condition(0));
       break;
     }
+    case kS390_I8x16Abs: {
+      __ vlp(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0),
+             Condition(0), Condition(0));
+      break;
+    }
+    case kS390_I16x8Abs: {
+      __ vlp(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0),
+             Condition(0), Condition(1));
+      break;
+    }
+    case kS390_I32x4Abs: {
+      __ vlp(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0),
+             Condition(0), Condition(2));
+      break;
+    }
     // vector boolean unops
+    case kS390_S1x2AnyTrue:
     case kS390_S1x4AnyTrue:
     case kS390_S1x8AnyTrue:
     case kS390_S1x16AnyTrue: {
@@ -3443,20 +3867,36 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ locgr(Condition(8), dst, temp);
       break;
     }
-    case kS390_S1x4AllTrue:
-    case kS390_S1x8AllTrue:
+#define SIMD_ALL_TRUE(mode)                                                    \
+  Simd128Register src = i.InputSimd128Register(0);                             \
+  Register dst = i.OutputRegister();                                           \
+  Register temp = i.TempRegister(0);                                           \
+  __ lgfi(temp, Operand(1));                                                   \
+  __ xgr(dst, dst);                                                            \
+  __ vx(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg, Condition(0), \
+        Condition(0), Condition(2));                                           \
+  __ vceq(kScratchDoubleReg, src, kScratchDoubleReg, Condition(0),             \
+          Condition(mode));                                                    \
+  __ vtm(kScratchDoubleReg, kScratchDoubleReg, Condition(0), Condition(0),     \
+         Condition(0));                                                        \
+  __ locgr(Condition(8), dst, temp);
+    case kS390_S1x2AllTrue: {
+      SIMD_ALL_TRUE(3)
+      break;
+    }
+    case kS390_S1x4AllTrue: {
+      SIMD_ALL_TRUE(2)
+      break;
+    }
+    case kS390_S1x8AllTrue: {
+      SIMD_ALL_TRUE(1)
+      break;
+    }
     case kS390_S1x16AllTrue: {
-      Simd128Register src = i.InputSimd128Register(0);
-      Register dst = i.OutputRegister();
-      Register temp = i.TempRegister(0);
-      __ lgfi(temp, Operand(1));
-      __ xgr(dst, dst);
-      __ vceq(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg,
-              Condition(0), Condition(2));
-      __ vtm(src, kScratchDoubleReg, Condition(0), Condition(0), Condition(0));
-      __ locgr(Condition(1), dst, temp);
+      SIMD_ALL_TRUE(0)
       break;
     }
+#undef SIMD_ALL_TRUE
     // vector bitwise ops
     case kS390_S128And: {
       Simd128Register dst = i.OutputSimd128Register();
@@ -3481,8 +3921,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
     case kS390_S128Zero: {
       Simd128Register dst = i.OutputSimd128Register();
-      Simd128Register src = i.InputSimd128Register(1);
-      __ vx(dst, dst, src, Condition(0), Condition(0), Condition(0));
+      __ vx(dst, dst, dst, Condition(0), Condition(0), Condition(0));
       break;
     }
     case kS390_S128Select: {
@@ -3493,6 +3932,284 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ vsel(dst, src1, src2, mask, Condition(0), Condition(0));
       break;
     }
+    case kS390_S128AndNot: {
+      Simd128Register dst = i.OutputSimd128Register();
+      Simd128Register src = i.InputSimd128Register(1);
+      __ vnc(dst, i.InputSimd128Register(0), src, Condition(0), Condition(0),
+             Condition(0));
+      break;
+    }
+    // vector conversions
+#define CONVERT_FLOAT_TO_INT32(convert)                             \
+  for (int index = 0; index < 4; index++) {                         \
+    __ vlgv(kScratchReg, kScratchDoubleReg, MemOperand(r0, index),  \
+            Condition(2));                                          \
+    __ MovIntToFloat(tempFPReg1, kScratchReg);                      \
+    __ convert(kScratchReg, tempFPReg1, kRoundToZero);              \
+    __ vlvg(dst, kScratchReg, MemOperand(r0, index), Condition(2)); \
+  }
+    case kS390_I32x4SConvertF32x4: {
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register dst = i.OutputSimd128Register();
+      Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
+      // NaN to 0
+      __ vlr(kScratchDoubleReg, src, Condition(0), Condition(0), Condition(0));
+      __ vfce(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg,
+              Condition(0), Condition(0), Condition(2));
+      __ vn(kScratchDoubleReg, src, kScratchDoubleReg, Condition(0),
+            Condition(0), Condition(0));
+      CONVERT_FLOAT_TO_INT32(ConvertFloat32ToInt32)
+      break;
+    }
+    case kS390_I32x4UConvertF32x4: {
+      Simd128Register src = i.InputSimd128Register(0);
+      Simd128Register dst = i.OutputSimd128Register();
+      Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));
+      // NaN to 0, negative to 0
+      __ vx(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg,
+            Condition(0), Condition(0), Condition(0));
+      __ vfmax(kScratchDoubleReg, src, kScratchDoubleReg, Condition(1),
+               Condition(0), Condition(2));
+      CONVERT_FLOAT_TO_INT32(ConvertFloat32ToUnsignedInt32)
+      break;
+    }
+#undef CONVERT_FLOAT_TO_INT32
+#define CONVERT_INT32_TO_FLOAT(convert, double_index)               \
+  Simd128Register src = i.InputSimd128Register(0);                  \
+  Simd128Register dst = i.OutputSimd128Register();                  \
+  for (int index = 0; index < 4; index++) {                         \
+    __ vlgv(kScratchReg, src, MemOperand(r0, index), Condition(2)); \
+    __ convert(kScratchDoubleReg, kScratchReg);                     \
+    __ MovFloatToInt(kScratchReg, kScratchDoubleReg);               \
+    __ vlvg(dst, kScratchReg, MemOperand(r0, index), Condition(2)); \
+  }
+    case kS390_F32x4SConvertI32x4: {
+#ifdef V8_TARGET_BIG_ENDIAN
+      CONVERT_INT32_TO_FLOAT(ConvertIntToFloat, 0)
+#else
+      CONVERT_INT32_TO_FLOAT(ConvertIntToFloat, 1)
+#endif
+      break;
+    }
+    case kS390_F32x4UConvertI32x4: {
+#ifdef V8_TARGET_BIG_ENDIAN
+      CONVERT_INT32_TO_FLOAT(ConvertUnsignedIntToFloat, 0)
+#else
+      CONVERT_INT32_TO_FLOAT(ConvertUnsignedIntToFloat, 1)
+#endif
+      break;
+    }
+#undef CONVERT_INT32_TO_FLOAT
+#define VECTOR_UNPACK(op, mode)                                             \
+  __ op(i.OutputSimd128Register(), i.InputSimd128Register(0), Condition(0), \
+        Condition(0), Condition(mode));
+    case kS390_I32x4SConvertI16x8Low: {
+      VECTOR_UNPACK(vupl, 1)
+      break;
+    }
+    case kS390_I32x4SConvertI16x8High: {
+      VECTOR_UNPACK(vuph, 1)
+      break;
+    }
+    case kS390_I32x4UConvertI16x8Low: {
+      VECTOR_UNPACK(vupll, 1)
+      break;
+    }
+    case kS390_I32x4UConvertI16x8High: {
+      VECTOR_UNPACK(vuplh, 1)
+      break;
+    }
+    case kS390_I16x8SConvertI8x16Low: {
+      VECTOR_UNPACK(vupl, 0)
+      break;
+    }
+    case kS390_I16x8SConvertI8x16High: {
+      VECTOR_UNPACK(vuph, 0)
+      break;
+    }
+    case kS390_I16x8UConvertI8x16Low: {
+      VECTOR_UNPACK(vupll, 0)
+      break;
+    }
+    case kS390_I16x8UConvertI8x16High: {
+      VECTOR_UNPACK(vuplh, 0)
+      break;
+    }
+#undef VECTOR_UNPACK
+    case kS390_I16x8SConvertI32x4:
+      __ vpks(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(2));
+      break;
+    case kS390_I8x16SConvertI16x8:
+      __ vpks(i.OutputSimd128Register(), i.InputSimd128Register(0),
+              i.InputSimd128Register(1), Condition(0), Condition(1));
+      break;
+#define VECTOR_PACK_UNSIGNED(mode)                                             \
+  Simd128Register tempFPReg = i.ToSimd128Register(instr->TempAt(0));           \
+  __ vx(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg, Condition(0), \
+        Condition(0), Condition(mode));                                        \
+  __ vmx(tempFPReg, i.InputSimd128Register(0), kScratchDoubleReg,              \
+         Condition(0), Condition(0), Condition(mode));                         \
+  __ vmx(kScratchDoubleReg, i.InputSimd128Register(1), kScratchDoubleReg,      \
+         Condition(0), Condition(0), Condition(mode));                         \
+  __ vpkls(i.OutputSimd128Register(), tempFPReg, kScratchDoubleReg,            \
+           Condition(0), Condition(mode));
+    case kS390_I16x8UConvertI32x4: {
+      // treat inputs as signed, and saturate to unsigned (negative to 0)
+      VECTOR_PACK_UNSIGNED(2)
+      break;
+    }
+    case kS390_I8x16UConvertI16x8: {
+      // treat inputs as signed, and saturate to unsigned (negative to 0)
+      VECTOR_PACK_UNSIGNED(1)
+      break;
+    }
+#undef VECTOR_PACK_UNSIGNED
+#define BINOP_EXTRACT(op, extract_high, extract_low, mode)              \
+  Simd128Register src1 = i.InputSimd128Register(0);                     \
+  Simd128Register src2 = i.InputSimd128Register(1);                     \
+  Simd128Register tempFPReg1 = i.ToSimd128Register(instr->TempAt(0));   \
+  Simd128Register tempFPReg2 = i.ToSimd128Register(instr->TempAt(1));   \
+  __ extract_high(kScratchDoubleReg, src1, Condition(0), Condition(0),  \
+                  Condition(mode));                                     \
+  __ extract_high(tempFPReg1, src2, Condition(0), Condition(0),         \
+                  Condition(mode));                                     \
+  __ op(kScratchDoubleReg, kScratchDoubleReg, tempFPReg1, Condition(0), \
+        Condition(0), Condition(mode + 1));                             \
+  __ extract_low(tempFPReg1, src1, Condition(0), Condition(0),          \
+                 Condition(mode));                                      \
+  __ extract_low(tempFPReg2, src2, Condition(0), Condition(0),          \
+                 Condition(mode));                                      \
+  __ op(tempFPReg1, tempFPReg1, tempFPReg2, Condition(0), Condition(0), \
+        Condition(mode + 1));
+    case kS390_I16x8AddSaturateS: {
+      BINOP_EXTRACT(va, vuph, vupl, 1)
+      __ vpks(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+              Condition(0), Condition(2));
+      break;
+    }
+    case kS390_I16x8SubSaturateS: {
+      BINOP_EXTRACT(vs, vuph, vupl, 1)
+      __ vpks(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+              Condition(0), Condition(2));
+      break;
+    }
+    case kS390_I16x8AddSaturateU: {
+      BINOP_EXTRACT(va, vuplh, vupll, 1)
+      __ vpkls(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+               Condition(0), Condition(2));
+      break;
+    }
+    case kS390_I16x8SubSaturateU: {
+      BINOP_EXTRACT(vs, vuplh, vupll, 1)
+      // negative to 0
+      __ vx(tempFPReg2, tempFPReg2, tempFPReg2, Condition(0), Condition(0),
+            Condition(0));
+      __ vmx(kScratchDoubleReg, tempFPReg2, kScratchDoubleReg, Condition(0),
+             Condition(0), Condition(2));
+      __ vmx(tempFPReg1, tempFPReg2, tempFPReg1, Condition(0), Condition(0),
+             Condition(2));
+      __ vpkls(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+               Condition(0), Condition(2));
+      break;
+    }
+    case kS390_I8x16AddSaturateS: {
+      BINOP_EXTRACT(va, vuph, vupl, 0)
+      __ vpks(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+              Condition(0), Condition(1));
+      break;
+    }
+    case kS390_I8x16SubSaturateS: {
+      BINOP_EXTRACT(vs, vuph, vupl, 0)
+      __ vpks(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+              Condition(0), Condition(1));
+      break;
+    }
+    case kS390_I8x16AddSaturateU: {
+      BINOP_EXTRACT(va, vuplh, vupll, 0)
+      __ vpkls(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+               Condition(0), Condition(1));
+      break;
+    }
+    case kS390_I8x16SubSaturateU: {
+      BINOP_EXTRACT(vs, vuplh, vupll, 0)
+      // negative to 0
+      __ vx(tempFPReg2, tempFPReg2, tempFPReg2, Condition(0), Condition(0),
+            Condition(0));
+      __ vmx(kScratchDoubleReg, tempFPReg2, kScratchDoubleReg, Condition(0),
+             Condition(0), Condition(1));
+      __ vmx(tempFPReg1, tempFPReg2, tempFPReg1, Condition(0), Condition(0),
+             Condition(1));
+      __ vpkls(i.OutputSimd128Register(), kScratchDoubleReg, tempFPReg1,
+               Condition(0), Condition(1));
+      break;
+    }
+#undef BINOP_EXTRACT
+    case kS390_S8x16Shuffle: {
+      Simd128Register dst = i.OutputSimd128Register(),
+                      src0 = i.InputSimd128Register(0),
+                      src1 = i.InputSimd128Register(1);
+      int32_t k8x16_indices[] = {i.InputInt32(2), i.InputInt32(3),
+                                 i.InputInt32(4), i.InputInt32(5)};
+      // create 2 * 8 byte inputs indicating new indices
+      for (int i = 0, j = 0; i < 2; i++, j = +2) {
+#ifdef V8_TARGET_BIG_ENDIAN
+        __ lgfi(i < 1 ? ip : r0, Operand(k8x16_indices[j + 1]));
+        __ aih(i < 1 ? ip : r0, Operand(k8x16_indices[j]));
+#else
+        __ lgfi(i < 1 ? ip : r0, Operand(k8x16_indices[j]));
+        __ aih(i < 1 ? ip : r0, Operand(k8x16_indices[j + 1]));
+#endif
+      }
+      __ vlvgp(kScratchDoubleReg, ip, r0);
+      __ vperm(dst, src0, src1, kScratchDoubleReg, Condition(0), Condition(0));
+      break;
+    }
+    case kS390_S8x16Swizzle: {
+      Simd128Register dst = i.OutputSimd128Register(),
+                      src0 = i.InputSimd128Register(0),
+                      src1 = i.InputSimd128Register(1);
+#ifdef V8_TARGET_BIG_ENDIAN
+      //  input needs to be reversed
+      __ vlgv(r0, src0, MemOperand(r0, 0), Condition(3));
+      __ vlgv(r1, src0, MemOperand(r0, 1), Condition(3));
+      __ lrvgr(r0, r0);
+      __ lrvgr(r1, r1);
+      __ vlvgp(kScratchDoubleReg, r1, r0);
+      // clear scr0
+      __ vx(src0, src0, src0, Condition(0), Condition(0), Condition(0));
+      __ vperm(dst, kScratchDoubleReg, src0, src1, Condition(0), Condition(0));
+#else
+      __ vx(kScratchDoubleReg, kScratchDoubleReg, kScratchDoubleReg,
+            Condition(0), Condition(0), Condition(0));
+      __ vperm(dst, src0, kScratchDoubleReg, src1, Condition(0), Condition(0));
+#endif
+      break;
+    }
+    case kS390_StoreCompressTagged: {
+      CHECK(!instr->HasOutput());
+      size_t index = 0;
+      AddressingMode mode = kMode_None;
+      MemOperand operand = i.MemoryOperand(&mode, &index);
+      Register value = i.InputRegister(index);
+      __ StoreTaggedField(value, operand, r1);
+      break;
+    }
+    case kS390_LoadDecompressTaggedSigned: {
+      CHECK(instr->HasOutput());
+      __ DecompressTaggedSigned(i.OutputRegister(), i.MemoryOperand());
+      break;
+    }
+    case kS390_LoadDecompressTaggedPointer: {
+      CHECK(instr->HasOutput());
+      __ DecompressTaggedPointer(i.OutputRegister(), i.MemoryOperand());
+      break;
+    }
+    case kS390_LoadDecompressAnyTagged: {
+      CHECK(instr->HasOutput());
+      __ DecompressAnyTagged(i.OutputRegister(), i.MemoryOperand());
+      break;
+    }
     default:
       UNREACHABLE();
   }
@@ -3653,16 +4370,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  S390OperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ Cmp32(input, Operand(i.InputInt32(index + 0)));
-    __ beq(GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   S390OperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -3729,14 +4436,16 @@ void CodeGenerator::AssembleConstructFrame() {
         __ Push(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
-        __ LoadP(kJSFunctionRegister,
-                 FieldMemOperand(kWasmInstanceRegister, Tuple2::kValue2Offset));
-        __ LoadP(kWasmInstanceRegister,
-                 FieldMemOperand(kWasmInstanceRegister, Tuple2::kValue1Offset));
+        __ LoadTaggedPointerField(
+            kJSFunctionRegister,
+            FieldMemOperand(kWasmInstanceRegister, Tuple2::kValue2Offset), r0);
+        __ LoadTaggedPointerField(
+            kWasmInstanceRegister,
+            FieldMemOperand(kWasmInstanceRegister, Tuple2::kValue1Offset), r0);
         __ Push(kWasmInstanceRegister);
         if (call_descriptor->IsWasmCapiFunction()) {
           // Reserve space for saving the PC later.
@@ -3956,9 +4665,16 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
           }
           break;
         }
-        case Constant::kCompressedHeapObject:
-          UNREACHABLE();
+        case Constant::kCompressedHeapObject: {
+          Handle<HeapObject> src_object = src.ToHeapObject();
+          RootIndex index;
+          if (IsMaterializableFromRoot(src_object, &index)) {
+            __ LoadRoot(dst, index);
+          } else {
+            __ Move(dst, src_object, RelocInfo::COMPRESSED_EMBEDDED_OBJECT);
+          }
           break;
+        }
         case Constant::kRpoNumber:
           UNREACHABLE();  // TODO(dcarney): loading RPO constants on S390.
           break;
@@ -3986,17 +4702,29 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
       }
     }
   } else if (source->IsFPRegister()) {
-    DoubleRegister src = g.ToDoubleRegister(source);
-    if (destination->IsFPRegister()) {
-      DoubleRegister dst = g.ToDoubleRegister(destination);
-      __ Move(dst, src);
+    MachineRepresentation rep = LocationOperand::cast(source)->representation();
+    if (rep == MachineRepresentation::kSimd128) {
+      if (destination->IsSimd128Register()) {
+        __ vlr(g.ToSimd128Register(destination), g.ToSimd128Register(source),
+               Condition(0), Condition(0), Condition(0));
+      } else {
+        DCHECK(destination->IsSimd128StackSlot());
+        __ StoreSimd128(g.ToSimd128Register(source),
+                        g.ToMemOperand(destination), kScratchReg);
+      }
     } else {
-      DCHECK(destination->IsFPStackSlot());
-      LocationOperand* op = LocationOperand::cast(source);
-      if (op->representation() == MachineRepresentation::kFloat64) {
-        __ StoreDouble(src, g.ToMemOperand(destination));
+      DoubleRegister src = g.ToDoubleRegister(source);
+      if (destination->IsFPRegister()) {
+        DoubleRegister dst = g.ToDoubleRegister(destination);
+        __ Move(dst, src);
       } else {
-        __ StoreFloat32(src, g.ToMemOperand(destination));
+        DCHECK(destination->IsFPStackSlot());
+        LocationOperand* op = LocationOperand::cast(source);
+        if (op->representation() == MachineRepresentation::kFloat64) {
+          __ StoreDouble(src, g.ToMemOperand(destination));
+        } else {
+          __ StoreFloat32(src, g.ToMemOperand(destination));
+        }
       }
     }
   } else if (source->IsFPStackSlot()) {
@@ -4006,8 +4734,12 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
       LocationOperand* op = LocationOperand::cast(source);
       if (op->representation() == MachineRepresentation::kFloat64) {
         __ LoadDouble(g.ToDoubleRegister(destination), src);
-      } else {
+      } else if (op->representation() == MachineRepresentation::kFloat32) {
         __ LoadFloat32(g.ToDoubleRegister(destination), src);
+      } else {
+        DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
+        __ LoadSimd128(g.ToSimd128Register(destination), g.ToMemOperand(source),
+                       kScratchReg);
       }
     } else {
       LocationOperand* op = LocationOperand::cast(source);
@@ -4015,9 +4747,14 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
       if (op->representation() == MachineRepresentation::kFloat64) {
         __ LoadDouble(temp, src);
         __ StoreDouble(temp, g.ToMemOperand(destination));
-      } else {
+      } else if (op->representation() == MachineRepresentation::kFloat32) {
         __ LoadFloat32(temp, src);
         __ StoreFloat32(temp, g.ToMemOperand(destination));
+      } else {
+        DCHECK_EQ(MachineRepresentation::kSimd128, op->representation());
+        __ LoadSimd128(kScratchDoubleReg, g.ToMemOperand(source), kScratchReg);
+        __ StoreSimd128(kScratchDoubleReg, g.ToMemOperand(destination),
+                        kScratchReg);
       }
     }
   } else {
@@ -4067,13 +4804,23 @@ void CodeGenerator::AssembleSwap(InstructionOperand* source,
   } else if (source->IsFloatStackSlot()) {
     DCHECK(destination->IsFloatStackSlot());
     __ SwapFloat32(g.ToMemOperand(source), g.ToMemOperand(destination),
-                   kScratchDoubleReg, d0);
+                   kScratchDoubleReg);
   } else if (source->IsDoubleStackSlot()) {
     DCHECK(destination->IsDoubleStackSlot());
     __ SwapDouble(g.ToMemOperand(source), g.ToMemOperand(destination),
-                  kScratchDoubleReg, d0);
+                  kScratchDoubleReg);
   } else if (source->IsSimd128Register()) {
-    UNREACHABLE();
+    Simd128Register src = g.ToSimd128Register(source);
+    if (destination->IsSimd128Register()) {
+      __ SwapSimd128(src, g.ToSimd128Register(destination), kScratchDoubleReg);
+    } else {
+      DCHECK(destination->IsSimd128StackSlot());
+      __ SwapSimd128(src, g.ToMemOperand(destination), kScratchDoubleReg);
+    }
+  } else if (source->IsSimd128StackSlot()) {
+    DCHECK(destination->IsSimd128StackSlot());
+    __ SwapSimd128(g.ToMemOperand(source), g.ToMemOperand(destination),
+                   kScratchDoubleReg);
   } else {
     UNREACHABLE();
   }
diff --git a/deps/v8/src/compiler/backend/s390/instruction-codes-s390.h b/deps/v8/src/compiler/backend/s390/instruction-codes-s390.h
index 165c811787..6101b22166 100644
--- a/deps/v8/src/compiler/backend/s390/instruction-codes-s390.h
+++ b/deps/v8/src/compiler/backend/s390/instruction-codes-s390.h
@@ -197,6 +197,24 @@ namespace compiler {
   V(S390_Word64AtomicXorUint16)             \
   V(S390_Word64AtomicXorUint32)             \
   V(S390_Word64AtomicXorUint64)             \
+  V(S390_F64x2Splat)                        \
+  V(S390_F64x2ReplaceLane)                  \
+  V(S390_F64x2Abs)                          \
+  V(S390_F64x2Neg)                          \
+  V(S390_F64x2Sqrt)                         \
+  V(S390_F64x2Add)                          \
+  V(S390_F64x2Sub)                          \
+  V(S390_F64x2Mul)                          \
+  V(S390_F64x2Div)                          \
+  V(S390_F64x2Eq)                           \
+  V(S390_F64x2Ne)                           \
+  V(S390_F64x2Lt)                           \
+  V(S390_F64x2Le)                           \
+  V(S390_F64x2Min)                          \
+  V(S390_F64x2Max)                          \
+  V(S390_F64x2ExtractLane)                  \
+  V(S390_F64x2Qfma)                         \
+  V(S390_F64x2Qfms)                         \
   V(S390_F32x4Splat)                        \
   V(S390_F32x4ExtractLane)                  \
   V(S390_F32x4ReplaceLane)                  \
@@ -212,6 +230,34 @@ namespace compiler {
   V(S390_F32x4Neg)                          \
   V(S390_F32x4RecipApprox)                  \
   V(S390_F32x4RecipSqrtApprox)              \
+  V(S390_F32x4SConvertI32x4)                \
+  V(S390_F32x4UConvertI32x4)                \
+  V(S390_F32x4Sqrt)                         \
+  V(S390_F32x4Div)                          \
+  V(S390_F32x4Min)                          \
+  V(S390_F32x4Max)                          \
+  V(S390_F32x4Qfma)                         \
+  V(S390_F32x4Qfms)                         \
+  V(S390_I64x2Neg)                          \
+  V(S390_I64x2Add)                          \
+  V(S390_I64x2Sub)                          \
+  V(S390_I64x2Shl)                          \
+  V(S390_I64x2ShrS)                         \
+  V(S390_I64x2ShrU)                         \
+  V(S390_I64x2Mul)                          \
+  V(S390_I64x2Splat)                        \
+  V(S390_I64x2ReplaceLane)                  \
+  V(S390_I64x2ExtractLane)                  \
+  V(S390_I64x2Eq)                           \
+  V(S390_I64x2Ne)                           \
+  V(S390_I64x2GtS)                          \
+  V(S390_I64x2GeS)                          \
+  V(S390_I64x2GtU)                          \
+  V(S390_I64x2GeU)                          \
+  V(S390_I64x2MinS)                         \
+  V(S390_I64x2MinU)                         \
+  V(S390_I64x2MaxS)                         \
+  V(S390_I64x2MaxU)                         \
   V(S390_I32x4Splat)                        \
   V(S390_I32x4ExtractLane)                  \
   V(S390_I32x4ReplaceLane)                  \
@@ -230,10 +276,17 @@ namespace compiler {
   V(S390_I32x4GtU)                          \
   V(S390_I32x4GeU)                          \
   V(S390_I32x4Neg)                          \
-  V(S390_I16x8Splat)                        \
   V(S390_I32x4Shl)                          \
   V(S390_I32x4ShrS)                         \
   V(S390_I32x4ShrU)                         \
+  V(S390_I32x4SConvertF32x4)                \
+  V(S390_I32x4UConvertF32x4)                \
+  V(S390_I32x4SConvertI16x8Low)             \
+  V(S390_I32x4SConvertI16x8High)            \
+  V(S390_I32x4UConvertI16x8Low)             \
+  V(S390_I32x4UConvertI16x8High)            \
+  V(S390_I32x4Abs)                          \
+  V(S390_I16x8Splat)                        \
   V(S390_I16x8ExtractLaneU)                 \
   V(S390_I16x8ExtractLaneS)                 \
   V(S390_I16x8ReplaceLane)                  \
@@ -255,6 +308,18 @@ namespace compiler {
   V(S390_I16x8ShrS)                         \
   V(S390_I16x8ShrU)                         \
   V(S390_I16x8Neg)                          \
+  V(S390_I16x8SConvertI32x4)                \
+  V(S390_I16x8UConvertI32x4)                \
+  V(S390_I16x8SConvertI8x16Low)             \
+  V(S390_I16x8SConvertI8x16High)            \
+  V(S390_I16x8UConvertI8x16Low)             \
+  V(S390_I16x8UConvertI8x16High)            \
+  V(S390_I16x8AddSaturateS)                 \
+  V(S390_I16x8SubSaturateS)                 \
+  V(S390_I16x8AddSaturateU)                 \
+  V(S390_I16x8SubSaturateU)                 \
+  V(S390_I16x8RoundingAverageU)             \
+  V(S390_I16x8Abs)                          \
   V(S390_I8x16Splat)                        \
   V(S390_I8x16ExtractLaneU)                 \
   V(S390_I8x16ExtractLaneS)                 \
@@ -276,9 +341,21 @@ namespace compiler {
   V(S390_I8x16ShrS)                         \
   V(S390_I8x16ShrU)                         \
   V(S390_I8x16Neg)                          \
+  V(S390_I8x16SConvertI16x8)                \
+  V(S390_I8x16UConvertI16x8)                \
+  V(S390_I8x16AddSaturateS)                 \
+  V(S390_I8x16SubSaturateS)                 \
+  V(S390_I8x16AddSaturateU)                 \
+  V(S390_I8x16SubSaturateU)                 \
+  V(S390_I8x16RoundingAverageU)             \
+  V(S390_I8x16Abs)                          \
+  V(S390_S8x16Shuffle)                      \
+  V(S390_S8x16Swizzle)                      \
+  V(S390_S1x2AnyTrue)                       \
   V(S390_S1x4AnyTrue)                       \
   V(S390_S1x8AnyTrue)                       \
   V(S390_S1x16AnyTrue)                      \
+  V(S390_S1x2AllTrue)                       \
   V(S390_S1x4AllTrue)                       \
   V(S390_S1x8AllTrue)                       \
   V(S390_S1x16AllTrue)                      \
@@ -288,8 +365,13 @@ namespace compiler {
   V(S390_S128Zero)                          \
   V(S390_S128Not)                           \
   V(S390_S128Select)                        \
+  V(S390_S128AndNot)                        \
   V(S390_StoreSimd128)                      \
-  V(S390_LoadSimd128)
+  V(S390_LoadSimd128)                       \
+  V(S390_StoreCompressTagged)               \
+  V(S390_LoadDecompressTaggedSigned)        \
+  V(S390_LoadDecompressTaggedPointer)       \
+  V(S390_LoadDecompressAnyTagged)
 
 // Addressing modes represent the "shape" of inputs to an instruction.
 // Many instructions support multiple addressing modes. Addressing modes
diff --git a/deps/v8/src/compiler/backend/s390/instruction-scheduler-s390.cc b/deps/v8/src/compiler/backend/s390/instruction-scheduler-s390.cc
index 50d23766b6..502ce229f5 100644
--- a/deps/v8/src/compiler/backend/s390/instruction-scheduler-s390.cc
+++ b/deps/v8/src/compiler/backend/s390/instruction-scheduler-s390.cc
@@ -143,6 +143,24 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_CompressSigned:
     case kS390_CompressPointer:
     case kS390_CompressAny:
+    case kS390_F64x2Splat:
+    case kS390_F64x2ReplaceLane:
+    case kS390_F64x2Abs:
+    case kS390_F64x2Neg:
+    case kS390_F64x2Sqrt:
+    case kS390_F64x2Add:
+    case kS390_F64x2Sub:
+    case kS390_F64x2Mul:
+    case kS390_F64x2Div:
+    case kS390_F64x2Eq:
+    case kS390_F64x2Ne:
+    case kS390_F64x2Lt:
+    case kS390_F64x2Le:
+    case kS390_F64x2Min:
+    case kS390_F64x2Max:
+    case kS390_F64x2ExtractLane:
+    case kS390_F64x2Qfma:
+    case kS390_F64x2Qfms:
     case kS390_F32x4Splat:
     case kS390_F32x4ExtractLane:
     case kS390_F32x4ReplaceLane:
@@ -158,6 +176,34 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_F32x4Neg:
     case kS390_F32x4RecipApprox:
     case kS390_F32x4RecipSqrtApprox:
+    case kS390_F32x4SConvertI32x4:
+    case kS390_F32x4UConvertI32x4:
+    case kS390_F32x4Sqrt:
+    case kS390_F32x4Div:
+    case kS390_F32x4Min:
+    case kS390_F32x4Max:
+    case kS390_F32x4Qfma:
+    case kS390_F32x4Qfms:
+    case kS390_I64x2Neg:
+    case kS390_I64x2Add:
+    case kS390_I64x2Sub:
+    case kS390_I64x2Shl:
+    case kS390_I64x2ShrS:
+    case kS390_I64x2ShrU:
+    case kS390_I64x2Mul:
+    case kS390_I64x2Splat:
+    case kS390_I64x2ReplaceLane:
+    case kS390_I64x2ExtractLane:
+    case kS390_I64x2Eq:
+    case kS390_I64x2Ne:
+    case kS390_I64x2GtS:
+    case kS390_I64x2GeS:
+    case kS390_I64x2GtU:
+    case kS390_I64x2GeU:
+    case kS390_I64x2MinS:
+    case kS390_I64x2MinU:
+    case kS390_I64x2MaxS:
+    case kS390_I64x2MaxU:
     case kS390_I32x4Splat:
     case kS390_I32x4ExtractLane:
     case kS390_I32x4ReplaceLane:
@@ -179,6 +225,13 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_I32x4ShrS:
     case kS390_I32x4ShrU:
     case kS390_I32x4Neg:
+    case kS390_I32x4SConvertF32x4:
+    case kS390_I32x4UConvertF32x4:
+    case kS390_I32x4SConvertI16x8Low:
+    case kS390_I32x4SConvertI16x8High:
+    case kS390_I32x4UConvertI16x8Low:
+    case kS390_I32x4UConvertI16x8High:
+    case kS390_I32x4Abs:
     case kS390_I16x8Splat:
     case kS390_I16x8ExtractLaneU:
     case kS390_I16x8ExtractLaneS:
@@ -201,6 +254,18 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_I16x8ShrS:
     case kS390_I16x8ShrU:
     case kS390_I16x8Neg:
+    case kS390_I16x8SConvertI32x4:
+    case kS390_I16x8UConvertI32x4:
+    case kS390_I16x8SConvertI8x16Low:
+    case kS390_I16x8SConvertI8x16High:
+    case kS390_I16x8UConvertI8x16Low:
+    case kS390_I16x8UConvertI8x16High:
+    case kS390_I16x8AddSaturateS:
+    case kS390_I16x8SubSaturateS:
+    case kS390_I16x8AddSaturateU:
+    case kS390_I16x8SubSaturateU:
+    case kS390_I16x8RoundingAverageU:
+    case kS390_I16x8Abs:
     case kS390_I8x16Splat:
     case kS390_I8x16ExtractLaneU:
     case kS390_I8x16ExtractLaneS:
@@ -222,9 +287,21 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_I8x16ShrS:
     case kS390_I8x16ShrU:
     case kS390_I8x16Neg:
+    case kS390_I8x16SConvertI16x8:
+    case kS390_I8x16UConvertI16x8:
+    case kS390_I8x16AddSaturateS:
+    case kS390_I8x16SubSaturateS:
+    case kS390_I8x16AddSaturateU:
+    case kS390_I8x16SubSaturateU:
+    case kS390_I8x16RoundingAverageU:
+    case kS390_I8x16Abs:
+    case kS390_S8x16Shuffle:
+    case kS390_S8x16Swizzle:
+    case kS390_S1x2AnyTrue:
     case kS390_S1x4AnyTrue:
     case kS390_S1x8AnyTrue:
     case kS390_S1x16AnyTrue:
+    case kS390_S1x2AllTrue:
     case kS390_S1x4AllTrue:
     case kS390_S1x8AllTrue:
     case kS390_S1x16AllTrue:
@@ -234,6 +311,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_S128Zero:
     case kS390_S128Not:
     case kS390_S128Select:
+    case kS390_S128AndNot:
       return kNoOpcodeFlags;
 
     case kS390_LoadWordS8:
@@ -250,6 +328,9 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_LoadReverse32:
     case kS390_LoadReverse64:
     case kS390_Peek:
+    case kS390_LoadDecompressTaggedSigned:
+    case kS390_LoadDecompressTaggedPointer:
+    case kS390_LoadDecompressAnyTagged:
       return kIsLoadOperation;
 
     case kS390_StoreWord8:
@@ -263,6 +344,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kS390_StoreFloat32:
     case kS390_StoreDouble:
     case kS390_StoreSimd128:
+    case kS390_StoreCompressTagged:
     case kS390_Push:
     case kS390_PushFrame:
     case kS390_StoreToStackSlot:
diff --git a/deps/v8/src/compiler/backend/s390/instruction-selector-s390.cc b/deps/v8/src/compiler/backend/s390/instruction-selector-s390.cc
index b66530f1dc..fdffb30e00 100644
--- a/deps/v8/src/compiler/backend/s390/instruction-selector-s390.cc
+++ b/deps/v8/src/compiler/backend/s390/instruction-selector-s390.cc
@@ -154,10 +154,12 @@ class S390OperandGenerator final : public OperandGenerator {
     switch (opcode) {
       case kS390_Cmp64:
       case kS390_LoadAndTestWord64:
-        return rep == MachineRepresentation::kWord64 || IsAnyTagged(rep);
+        return rep == MachineRepresentation::kWord64 ||
+               (!COMPRESS_POINTERS_BOOL && IsAnyTagged(rep));
       case kS390_LoadAndTestWord32:
       case kS390_Cmp32:
-        return rep == MachineRepresentation::kWord32;
+        return rep == MachineRepresentation::kWord32 ||
+               (COMPRESS_POINTERS_BOOL && IsAnyTagged(rep));
       default:
         break;
     }
@@ -285,29 +287,38 @@ ArchOpcode SelectLoadOpcode(Node* node) {
     case MachineRepresentation::kWord16:
       opcode = load_rep.IsSigned() ? kS390_LoadWordS16 : kS390_LoadWordU16;
       break;
-#if !V8_TARGET_ARCH_S390X
-    case MachineRepresentation::kTaggedSigned:   // Fall through.
-    case MachineRepresentation::kTaggedPointer:  // Fall through.
-    case MachineRepresentation::kTagged:         // Fall through.
-#endif
     case MachineRepresentation::kWord32:
       opcode = kS390_LoadWordU32;
       break;
-    case MachineRepresentation::kSimd128:
-      opcode = kS390_LoadSimd128;
+    case MachineRepresentation::kCompressedPointer:  // Fall through.
+    case MachineRepresentation::kCompressed:
+#ifdef V8_COMPRESS_POINTERS
+      opcode = kS390_LoadWordS32;
       break;
-#if V8_TARGET_ARCH_S390X
+#else
+      UNREACHABLE();
+#endif
+#ifdef V8_COMPRESS_POINTERS
+    case MachineRepresentation::kTaggedSigned:
+      opcode = kS390_LoadDecompressTaggedSigned;
+      break;
+    case MachineRepresentation::kTaggedPointer:
+      opcode = kS390_LoadDecompressTaggedPointer;
+      break;
+    case MachineRepresentation::kTagged:
+      opcode = kS390_LoadDecompressAnyTagged;
+      break;
+#else
     case MachineRepresentation::kTaggedSigned:   // Fall through.
     case MachineRepresentation::kTaggedPointer:  // Fall through.
     case MachineRepresentation::kTagged:         // Fall through.
+#endif
     case MachineRepresentation::kWord64:
       opcode = kS390_LoadWord64;
       break;
-#else
-    case MachineRepresentation::kWord64:  // Fall through.
-#endif
-    case MachineRepresentation::kCompressedPointer:  // Fall through.
-    case MachineRepresentation::kCompressed:         // Fall through.
+    case MachineRepresentation::kSimd128:
+      opcode = kS390_LoadSimd128;
+      break;
     case MachineRepresentation::kNone:
     default:
       UNREACHABLE();
@@ -683,8 +694,7 @@ void InstructionSelector::VisitAbortCSAAssert(Node* node) {
 void InstructionSelector::VisitLoad(Node* node) {
   S390OperandGenerator g(this);
   InstructionCode opcode = SelectLoadOpcode(node);
-  InstructionOperand outputs[1];
-  outputs[0] = g.DefineAsRegister(node);
+  InstructionOperand outputs[] = {g.DefineAsRegister(node)};
   InstructionOperand inputs[3];
   size_t input_count = 0;
   AddressingMode mode =
@@ -694,7 +704,6 @@ void InstructionSelector::VisitLoad(Node* node) {
     CHECK_NE(poisoning_level_, PoisoningMitigationLevel::kDontPoison);
     opcode |= MiscField::encode(kMemoryAccessPoisoned);
   }
-
   Emit(opcode, 1, outputs, input_count, inputs);
 }
 
@@ -714,7 +723,7 @@ static void VisitGeneralStore(
   Node* value = node->InputAt(2);
   if (write_barrier_kind != kNoWriteBarrier &&
       V8_LIKELY(!FLAG_disable_write_barriers)) {
-    DCHECK(CanBeTaggedPointer(rep));
+    DCHECK(CanBeTaggedOrCompressedPointer(rep));
     AddressingMode addressing_mode;
     InstructionOperand inputs[3];
     size_t input_count = 0;
@@ -754,13 +763,6 @@ static void VisitGeneralStore(
       case MachineRepresentation::kWord16:
         opcode = kS390_StoreWord16;
         break;
-#if !V8_TARGET_ARCH_S390X
-      case MachineRepresentation::kTaggedSigned:       // Fall through.
-      case MachineRepresentation::kTaggedPointer:      // Fall through.
-      case MachineRepresentation::kTagged:             // Fall through.
-      case MachineRepresentation::kCompressedPointer:  // Fall through.
-      case MachineRepresentation::kCompressed:         // Fall through.
-#endif
       case MachineRepresentation::kWord32:
         opcode = kS390_StoreWord32;
         if (m.IsWord32ReverseBytes()) {
@@ -768,19 +770,19 @@ static void VisitGeneralStore(
           value = value->InputAt(0);
         }
         break;
-      case MachineRepresentation::kSimd128:
-        opcode = kS390_StoreSimd128;
-        if (m.IsSimd128ReverseBytes()) {
-          opcode = kS390_StoreReverseSimd128;
-          value = value->InputAt(0);
-        }
-        break;
-#if V8_TARGET_ARCH_S390X
-      case MachineRepresentation::kTaggedSigned:       // Fall through.
-      case MachineRepresentation::kTaggedPointer:      // Fall through.
-      case MachineRepresentation::kTagged:             // Fall through.
       case MachineRepresentation::kCompressedPointer:  // Fall through.
-      case MachineRepresentation::kCompressed:         // Fall through.
+      case MachineRepresentation::kCompressed:
+#ifdef V8_COMPRESS_POINTERS
+        opcode = kS390_StoreCompressTagged;
+        break;
+#else
+        UNREACHABLE();
+#endif
+      case MachineRepresentation::kTaggedSigned:   // Fall through.
+      case MachineRepresentation::kTaggedPointer:  // Fall through.
+      case MachineRepresentation::kTagged:
+        opcode = kS390_StoreCompressTagged;
+        break;
       case MachineRepresentation::kWord64:
         opcode = kS390_StoreWord64;
         if (m.IsWord64ReverseBytes()) {
@@ -788,9 +790,13 @@ static void VisitGeneralStore(
           value = value->InputAt(0);
         }
         break;
-#else
-      case MachineRepresentation::kWord64:  // Fall through.
-#endif
+      case MachineRepresentation::kSimd128:
+        opcode = kS390_StoreSimd128;
+        if (m.IsSimd128ReverseBytes()) {
+          opcode = kS390_StoreReverseSimd128;
+          value = value->InputAt(0);
+        }
+        break;
       case MachineRepresentation::kNone:
         UNREACHABLE();
         return;
@@ -2068,7 +2074,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   S390OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -2222,12 +2228,21 @@ void InstructionSelector::EmitPrepareArguments(
     int num_slots = 0;
     int slot = 0;
 
+#define INPUT_SWITCH(param)                            \
+  switch (input.location.GetType().representation()) { \
+    case MachineRepresentation::kSimd128:              \
+      param += kSimd128Size / kSystemPointerSize;      \
+      break;                                           \
+    case MachineRepresentation::kFloat64:              \
+      param += kDoubleSize / kSystemPointerSize;       \
+      break;                                           \
+    default:                                           \
+      param += 1;                                      \
+      break;                                           \
+  }
     for (PushParameter input : *arguments) {
       if (input.node == nullptr) continue;
-      num_slots += input.location.GetType().representation() ==
-                           MachineRepresentation::kFloat64
-                       ? kDoubleSize / kSystemPointerSize
-                       : 1;
+      INPUT_SWITCH(num_slots)
     }
     Emit(kS390_StackClaim, g.NoOutput(), g.TempImmediate(num_slots));
     for (PushParameter input : *arguments) {
@@ -2235,12 +2250,10 @@ void InstructionSelector::EmitPrepareArguments(
       if (input.node) {
         Emit(kS390_StoreToStackSlot, g.NoOutput(), g.UseRegister(input.node),
              g.TempImmediate(slot));
-        slot += input.location.GetType().representation() ==
-                        MachineRepresentation::kFloat64
-                    ? (kDoubleSize / kSystemPointerSize)
-                    : 1;
+        INPUT_SWITCH(slot)
       }
     }
+#undef INPUT_SWITCH
     DCHECK(num_slots == slot);
   }
 }
@@ -2512,12 +2525,24 @@ void InstructionSelector::VisitWord64AtomicStore(Node* node) {
 }
 
 #define SIMD_TYPES(V) \
+  V(F64x2)            \
   V(F32x4)            \
+  V(I64x2)            \
   V(I32x4)            \
   V(I16x8)            \
   V(I8x16)
 
 #define SIMD_BINOP_LIST(V) \
+  V(F64x2Add)              \
+  V(F64x2Sub)              \
+  V(F64x2Mul)              \
+  V(F64x2Div)              \
+  V(F64x2Eq)               \
+  V(F64x2Ne)               \
+  V(F64x2Lt)               \
+  V(F64x2Le)               \
+  V(F64x2Min)              \
+  V(F64x2Max)              \
   V(F32x4Add)              \
   V(F32x4AddHoriz)         \
   V(F32x4Sub)              \
@@ -2526,6 +2551,22 @@ void InstructionSelector::VisitWord64AtomicStore(Node* node) {
   V(F32x4Ne)               \
   V(F32x4Lt)               \
   V(F32x4Le)               \
+  V(F32x4Div)              \
+  V(F32x4Min)              \
+  V(F32x4Max)              \
+  V(I64x2Add)              \
+  V(I64x2Sub)              \
+  V(I64x2Mul)              \
+  V(I64x2Eq)               \
+  V(I64x2Ne)               \
+  V(I64x2GtS)              \
+  V(I64x2GeS)              \
+  V(I64x2GtU)              \
+  V(I64x2GeU)              \
+  V(I64x2MinS)             \
+  V(I64x2MinU)             \
+  V(I64x2MaxS)             \
+  V(I64x2MaxU)             \
   V(I32x4Add)              \
   V(I32x4AddHoriz)         \
   V(I32x4Sub)              \
@@ -2554,6 +2595,13 @@ void InstructionSelector::VisitWord64AtomicStore(Node* node) {
   V(I16x8GeS)              \
   V(I16x8GtU)              \
   V(I16x8GeU)              \
+  V(I16x8SConvertI32x4)    \
+  V(I16x8UConvertI32x4)    \
+  V(I16x8AddSaturateS)     \
+  V(I16x8SubSaturateS)     \
+  V(I16x8AddSaturateU)     \
+  V(I16x8SubSaturateU)     \
+  V(I16x8RoundingAverageU) \
   V(I8x16Add)              \
   V(I8x16Sub)              \
   V(I8x16Mul)              \
@@ -2567,39 +2615,74 @@ void InstructionSelector::VisitWord64AtomicStore(Node* node) {
   V(I8x16GeS)              \
   V(I8x16GtU)              \
   V(I8x16GeU)              \
+  V(I8x16SConvertI16x8)    \
+  V(I8x16UConvertI16x8)    \
+  V(I8x16AddSaturateS)     \
+  V(I8x16SubSaturateS)     \
+  V(I8x16AddSaturateU)     \
+  V(I8x16SubSaturateU)     \
+  V(I8x16RoundingAverageU) \
   V(S128And)               \
   V(S128Or)                \
-  V(S128Xor)
-
-#define SIMD_UNOP_LIST(V) \
-  V(F32x4Abs)             \
-  V(F32x4Neg)             \
-  V(F32x4RecipApprox)     \
-  V(F32x4RecipSqrtApprox) \
-  V(I32x4Neg)             \
-  V(I16x8Neg)             \
-  V(I8x16Neg)             \
+  V(S128Xor)               \
+  V(S128AndNot)
+
+#define SIMD_UNOP_LIST(V)   \
+  V(F64x2Abs)               \
+  V(F64x2Neg)               \
+  V(F64x2Sqrt)              \
+  V(F32x4Abs)               \
+  V(F32x4Neg)               \
+  V(F32x4RecipApprox)       \
+  V(F32x4RecipSqrtApprox)   \
+  V(F32x4Sqrt)              \
+  V(I64x2Neg)               \
+  V(I16x8Abs)               \
+  V(I32x4Neg)               \
+  V(I32x4SConvertI16x8Low)  \
+  V(I32x4SConvertI16x8High) \
+  V(I32x4UConvertI16x8Low)  \
+  V(I32x4UConvertI16x8High) \
+  V(I32x4Abs)               \
+  V(I16x8Neg)               \
+  V(I16x8SConvertI8x16Low)  \
+  V(I16x8SConvertI8x16High) \
+  V(I16x8UConvertI8x16Low)  \
+  V(I16x8UConvertI8x16High) \
+  V(I8x16Neg)               \
+  V(I8x16Abs)               \
   V(S128Not)
 
-#define SIMD_SHIFT_OPCODES(V) \
-  V(I32x4Shl)                 \
-  V(I32x4ShrS)                \
-  V(I32x4ShrU)                \
-  V(I16x8Shl)                 \
-  V(I16x8ShrS)                \
-  V(I16x8ShrU)                \
-  V(I8x16Shl)                 \
-  V(I8x16ShrS)                \
+#define SIMD_SHIFT_LIST(V) \
+  V(I64x2Shl)              \
+  V(I64x2ShrS)             \
+  V(I64x2ShrU)             \
+  V(I32x4Shl)              \
+  V(I32x4ShrS)             \
+  V(I32x4ShrU)             \
+  V(I16x8Shl)              \
+  V(I16x8ShrS)             \
+  V(I16x8ShrU)             \
+  V(I8x16Shl)              \
+  V(I8x16ShrS)             \
   V(I8x16ShrU)
 
 #define SIMD_BOOL_LIST(V) \
+  V(S1x2AnyTrue)          \
   V(S1x4AnyTrue)          \
   V(S1x8AnyTrue)          \
   V(S1x16AnyTrue)         \
+  V(S1x2AllTrue)          \
   V(S1x4AllTrue)          \
   V(S1x8AllTrue)          \
   V(S1x16AllTrue)
 
+#define SIMD_CONVERSION_LIST(V) \
+  V(I32x4SConvertF32x4)         \
+  V(I32x4UConvertF32x4)         \
+  V(F32x4SConvertI32x4)         \
+  V(F32x4UConvertI32x4)
+
 #define SIMD_VISIT_SPLAT(Type)                               \
   void InstructionSelector::Visit##Type##Splat(Node* node) { \
     S390OperandGenerator g(this);                            \
@@ -2616,7 +2699,9 @@ SIMD_TYPES(SIMD_VISIT_SPLAT)
     Emit(kS390_##Type##ExtractLane##Sign, g.DefineAsRegister(node),      \
          g.UseRegister(node->InputAt(0)), g.UseImmediate(lane));         \
   }
+SIMD_VISIT_EXTRACT_LANE(F64x2, )
 SIMD_VISIT_EXTRACT_LANE(F32x4, )
+SIMD_VISIT_EXTRACT_LANE(I64x2, )
 SIMD_VISIT_EXTRACT_LANE(I32x4, )
 SIMD_VISIT_EXTRACT_LANE(I16x8, U)
 SIMD_VISIT_EXTRACT_LANE(I16x8, S)
@@ -2666,9 +2751,9 @@ SIMD_UNOP_LIST(SIMD_VISIT_UNOP)
          g.UseUniqueRegister(node->InputAt(0)),         \
          g.UseUniqueRegister(node->InputAt(1)));        \
   }
-SIMD_SHIFT_OPCODES(SIMD_VISIT_SHIFT)
+SIMD_SHIFT_LIST(SIMD_VISIT_SHIFT)
 #undef SIMD_VISIT_SHIFT
-#undef SIMD_SHIFT_OPCODES
+#undef SIMD_SHIFT_LIST
 
 #define SIMD_VISIT_BOOL(Opcode)                                           \
   void InstructionSelector::Visit##Opcode(Node* node) {                   \
@@ -2679,11 +2764,81 @@ SIMD_SHIFT_OPCODES(SIMD_VISIT_SHIFT)
   }
 SIMD_BOOL_LIST(SIMD_VISIT_BOOL)
 #undef SIMD_VISIT_BOOL
+#undef SIMD_BOOL_LIST
+
+#define SIMD_VISIT_CONVERSION(Opcode)                               \
+  void InstructionSelector::Visit##Opcode(Node* node) {             \
+    S390OperandGenerator g(this);                                   \
+    InstructionOperand temps[] = {g.TempSimd128Register()};         \
+    Emit(kS390_##Opcode, g.DefineAsRegister(node),                  \
+         g.UseRegister(node->InputAt(0)), arraysize(temps), temps); \
+  }
+SIMD_CONVERSION_LIST(SIMD_VISIT_CONVERSION)
+#undef SIMD_VISIT_CONVERSION
+#undef SIMD_CONVERSION_LIST
+
+#define SIMD_VISIT_QFMOP(Opcode)                        \
+  void InstructionSelector::Visit##Opcode(Node* node) { \
+    S390OperandGenerator g(this);                       \
+    Emit(kS390_##Opcode, g.DefineSameAsFirst(node),     \
+         g.UseUniqueRegister(node->InputAt(0)),         \
+         g.UseUniqueRegister(node->InputAt(1)),         \
+         g.UseRegister(node->InputAt(2)));              \
+  }
+SIMD_VISIT_QFMOP(F64x2Qfma)
+SIMD_VISIT_QFMOP(F64x2Qfms)
+SIMD_VISIT_QFMOP(F32x4Qfma)
+SIMD_VISIT_QFMOP(F32x4Qfms)
+#undef SIMD_VISIT_QFMOP
 #undef SIMD_TYPES
 
+void InstructionSelector::VisitS8x16Shuffle(Node* node) {
+  uint8_t shuffle[kSimd128Size];
+  bool is_swizzle;
+  CanonicalizeShuffle(node, shuffle, &is_swizzle);
+  S390OperandGenerator g(this);
+  Node* input0 = node->InputAt(0);
+  Node* input1 = node->InputAt(1);
+#ifdef V8_TARGET_BIG_ENDIAN
+  // input registers are each in reverse order, we will have to remap the
+  // shuffle indices
+  int max_index = 15;
+  int total_lane_count = 2 * kSimd128Size;
+  uint8_t shuffle_remapped[kSimd128Size];
+  for (int i = 0; i < kSimd128Size; i++) {
+    uint8_t current_index = shuffle[i];
+    shuffle_remapped[i] = (current_index <= max_index
+                               ? max_index - current_index
+                               : total_lane_count - current_index + max_index);
+  }
+  Emit(kS390_S8x16Shuffle, g.DefineAsRegister(node), g.UseRegister(input0),
+       g.UseRegister(input1),
+       // Pack4Lanes reverses the bytes, therefore we will need to pass it in
+       // reverse
+       g.UseImmediate(Pack4Lanes(shuffle_remapped + 12)),
+       g.UseImmediate(Pack4Lanes(shuffle_remapped + 8)),
+       g.UseImmediate(Pack4Lanes(shuffle_remapped + 4)),
+       g.UseImmediate(Pack4Lanes(shuffle_remapped)));
+#else
+  Emit(kS390_S8x16Shuffle, g.DefineAsRegister(node),
+       g.UseUniqueRegister(input0), g.UseUniqueRegister(input1),
+       g.UseImmediate(Pack4Lanes(shuffle)),
+       g.UseImmediate(Pack4Lanes(shuffle + 4)),
+       g.UseImmediate(Pack4Lanes(shuffle + 8)),
+       g.UseImmediate(Pack4Lanes(shuffle + 12)));
+#endif
+}
+
+void InstructionSelector::VisitS8x16Swizzle(Node* node) {
+  S390OperandGenerator g(this);
+  Emit(kS390_S8x16Swizzle, g.DefineAsRegister(node),
+       g.UseUniqueRegister(node->InputAt(0)),
+       g.UseUniqueRegister(node->InputAt(1)));
+}
+
 void InstructionSelector::VisitS128Zero(Node* node) {
   S390OperandGenerator g(this);
-  Emit(kS390_S128Zero, g.DefineAsRegister(node), g.DefineAsRegister(node));
+  Emit(kS390_S128Zero, g.DefineAsRegister(node));
 }
 
 void InstructionSelector::VisitS128Select(Node* node) {
@@ -2693,48 +2848,6 @@ void InstructionSelector::VisitS128Select(Node* node) {
        g.UseRegister(node->InputAt(2)));
 }
 
-void InstructionSelector::VisitI16x8AddSaturateS(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SubSaturateS(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8AddSaturateU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SubSaturateU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8RoundingAverageU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16RoundingAverageU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16AddSaturateS(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16SubSaturateS(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16AddSaturateU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16SubSaturateU(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitS128AndNot(Node* node) { UNIMPLEMENTED(); }
-
 void InstructionSelector::EmitPrepareResults(
     ZoneVector<PushParameter>* results, const CallDescriptor* call_descriptor,
     Node* node) {
@@ -2758,129 +2871,11 @@ void InstructionSelector::EmitPrepareResults(
   }
 }
 
-void InstructionSelector::VisitF32x4Sqrt(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF32x4Div(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF32x4Min(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF32x4Max(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF32x4SConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitF32x4UConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4SConvertF32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertF32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4SConvertI16x8Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4SConvertI16x8High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertI16x8Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI32x4UConvertI16x8High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI8x16Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI8x16High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8UConvertI8x16Low(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8UConvertI8x16High(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI16x8SConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-void InstructionSelector::VisitI16x8UConvertI32x4(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16SConvertI16x8(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitI8x16UConvertI16x8(Node* node) {
-  UNIMPLEMENTED();
+void InstructionSelector::VisitLoadTransform(Node* node) {
+  // We should never reach here, see http://crrev.com/c/2050811
+  UNREACHABLE();
 }
 
-void InstructionSelector::VisitS8x16Shuffle(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitS8x16Swizzle(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Splat(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2ReplaceLane(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Abs(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Neg(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Sqrt(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Add(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Sub(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Mul(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Div(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Eq(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Ne(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Lt(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Le(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2Neg(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2Add(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2Sub(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2Shl(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2ShrS(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2ShrU(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitI64x2Mul(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Min(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2Max(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitF64x2ExtractLane(Node* node) { UNIMPLEMENTED(); }
-
-void InstructionSelector::VisitLoadTransform(Node* node) { UNIMPLEMENTED(); }
-
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
diff --git a/deps/v8/src/compiler/backend/unwinding-info-writer.h b/deps/v8/src/compiler/backend/unwinding-info-writer.h
index 7f195db51b..a288e219a8 100644
--- a/deps/v8/src/compiler/backend/unwinding-info-writer.h
+++ b/deps/v8/src/compiler/backend/unwinding-info-writer.h
@@ -15,7 +15,7 @@
 #include "src/compiler/backend/x64/unwinding-info-writer-x64.h"
 #elif V8_TARGET_ARCH_S390X
 #include "src/compiler/backend/s390/unwinding-info-writer-s390.h"
-#elif V8_TARGET_ARCH_PPC64
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/compiler/backend/ppc/unwinding-info-writer-ppc.h"
 #else
 
diff --git a/deps/v8/src/compiler/backend/x64/code-generator-x64.cc b/deps/v8/src/compiler/backend/x64/code-generator-x64.cc
index 571502be77..472ffaa508 100644
--- a/deps/v8/src/compiler/backend/x64/code-generator-x64.cc
+++ b/deps/v8/src/compiler/backend/x64/code-generator-x64.cc
@@ -580,25 +580,41 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     ASSEMBLE_SIMD_INSTR(opcode, dst, input_index);       \
   } while (false)
 
-#define ASSEMBLE_SIMD_IMM_SHUFFLE(opcode, SSELevel, imm)                  \
+#define ASSEMBLE_SIMD_IMM_SHUFFLE(opcode, imm)                            \
   do {                                                                    \
-    CpuFeatureScope sse_scope(tasm(), SSELevel);                          \
     DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));      \
     __ opcode(i.OutputSimd128Register(), i.InputSimd128Register(1), imm); \
   } while (false)
 
-#define ASSEMBLE_SIMD_ALL_TRUE(opcode)           \
-  do {                                           \
-    CpuFeatureScope sse_scope(tasm(), SSE4_1);   \
-    Register dst = i.OutputRegister();           \
-    Register tmp1 = i.TempRegister(0);           \
-    XMMRegister tmp2 = i.TempSimd128Register(1); \
-    __ movq(tmp1, Immediate(1));                 \
-    __ xorq(dst, dst);                           \
-    __ pxor(tmp2, tmp2);                         \
-    __ opcode(tmp2, i.InputSimd128Register(0));  \
-    __ ptest(tmp2, tmp2);                        \
-    __ cmovq(zero, dst, tmp1);                   \
+#define ASSEMBLE_SIMD_ALL_TRUE(opcode)          \
+  do {                                          \
+    CpuFeatureScope sse_scope(tasm(), SSE4_1);  \
+    Register dst = i.OutputRegister();          \
+    XMMRegister tmp = i.TempSimd128Register(0); \
+    __ xorq(dst, dst);                          \
+    __ Pxor(tmp, tmp);                          \
+    __ opcode(tmp, i.InputSimd128Register(0));  \
+    __ Ptest(tmp, tmp);                         \
+    __ setcc(equal, dst);                       \
+  } while (false)
+
+// This macro will directly emit the opcode if the shift is an immediate - the
+// shift value will be taken modulo 2^width. Otherwise, it will emit code to
+// perform the modulus operation.
+#define ASSEMBLE_SIMD_SHIFT(opcode, width)                     \
+  do {                                                         \
+    XMMRegister dst = i.OutputSimd128Register();               \
+    DCHECK_EQ(dst, i.InputSimd128Register(0));                 \
+    if (HasImmediateInput(instr, 1)) {                         \
+      __ opcode(dst, static_cast<byte>(i.InputInt##width(1))); \
+    } else {                                                   \
+      XMMRegister tmp = i.TempSimd128Register(0);              \
+      Register shift = i.InputRegister(1);                     \
+      constexpr int mask = (1 << width) - 1;                   \
+      __ andq(shift, Immediate(mask));                         \
+      __ Movq(tmp, shift);                                     \
+      __ opcode(dst, tmp);                                     \
+    }                                                          \
   } while (false)
 
 void CodeGenerator::AssembleDeconstructFrame() {
@@ -969,9 +985,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchBinarySearchSwitch:
       AssembleArchBinarySearchSwitch(instr);
       break;
-    case kArchLookupSwitch:
-      AssembleArchLookupSwitch(instr);
-      break;
     case kArchTableSwitch:
       AssembleArchTableSwitch(instr);
       break;
@@ -992,7 +1005,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       unwinding_info_writer_.MarkBlockWillExit();
       break;
     case kArchDebugBreak:
-      __ int3();
+      __ DebugBreak();
       break;
     case kArchThrowTerminator:
       unwinding_info_writer_.MarkBlockWillExit();
@@ -2634,12 +2647,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I64x2Shl: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 8.
-      __ andq(shift, Immediate(63));
-      __ movq(tmp, shift);
-      __ psllq(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^6.
+      ASSEMBLE_SIMD_SHIFT(Psllq, 6);
       break;
     }
     case kX64I64x2ShrS: {
@@ -2652,14 +2661,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // Modulo 64 not required as sarq_cl will mask cl to 6 bits.
 
       // lower quadword
-      __ pextrq(tmp, src, 0x0);
+      __ Pextrq(tmp, src, static_cast<int8_t>(0x0));
       __ sarq_cl(tmp);
-      __ pinsrq(dst, tmp, 0x0);
+      __ Pinsrq(dst, tmp, static_cast<int8_t>(0x0));
 
       // upper quadword
-      __ pextrq(tmp, src, 0x1);
+      __ Pextrq(tmp, src, static_cast<int8_t>(0x1));
       __ sarq_cl(tmp);
-      __ pinsrq(dst, tmp, 0x1);
+      __ Pinsrq(dst, tmp, static_cast<int8_t>(0x1));
       break;
     }
     case kX64I64x2Add: {
@@ -2788,12 +2797,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I64x2ShrU: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 64.
-      __ andq(shift, Immediate(63));
-      __ movq(tmp, shift);
-      __ psrlq(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^6.
+      ASSEMBLE_SIMD_SHIFT(Psrlq, 6);
       break;
     }
     case kX64I64x2MinU: {
@@ -2904,18 +2909,18 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister tmp = i.TempSimd128Register(0);
       // NAN->0
-      __ movaps(tmp, dst);
-      __ cmpeqps(tmp, tmp);
-      __ pand(dst, tmp);
+      __ Movaps(tmp, dst);
+      __ Cmpeqps(tmp, tmp);
+      __ Pand(dst, tmp);
       // Set top bit if >= 0 (but not -0.0!)
-      __ pxor(tmp, dst);
+      __ Pxor(tmp, dst);
       // Convert
-      __ cvttps2dq(dst, dst);
+      __ Cvttps2dq(dst, dst);
       // Set top bit if >=0 is now < 0
-      __ pand(tmp, dst);
-      __ psrad(tmp, 31);
+      __ Pand(tmp, dst);
+      __ Psrad(tmp, static_cast<byte>(31));
       // Set positive overflow lanes to 0x7FFFFFFF
-      __ pxor(dst, tmp);
+      __ Pxor(dst, tmp);
       break;
     }
     case kX64I32x4SConvertI16x8Low: {
@@ -2943,21 +2948,13 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I32x4Shl: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ andq(shift, Immediate(31));
-      __ Movq(tmp, shift);
-      __ Pslld(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^5.
+      ASSEMBLE_SIMD_SHIFT(Pslld, 5);
       break;
     }
     case kX64I32x4ShrS: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ andq(shift, Immediate(31));
-      __ Movq(tmp, shift);
-      __ Psrad(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^5.
+      ASSEMBLE_SIMD_SHIFT(Psrad, 5);
       break;
     }
     case kX64I32x4Add: {
@@ -2966,7 +2963,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
     case kX64I32x4AddHoriz: {
       CpuFeatureScope sse_scope(tasm(), SSSE3);
-      __ phaddd(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Phaddd(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I32x4Sub: {
@@ -3018,26 +3015,26 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister tmp = i.TempSimd128Register(0);
       XMMRegister tmp2 = i.TempSimd128Register(1);
       // NAN->0, negative->0
-      __ pxor(tmp2, tmp2);
-      __ maxps(dst, tmp2);
+      __ Pxor(tmp2, tmp2);
+      __ Maxps(dst, tmp2);
       // scratch: float representation of max_signed
-      __ pcmpeqd(tmp2, tmp2);
-      __ psrld(tmp2, 1);        // 0x7fffffff
-      __ cvtdq2ps(tmp2, tmp2);  // 0x4f000000
+      __ Pcmpeqd(tmp2, tmp2);
+      __ Psrld(tmp2, static_cast<uint8_t>(1));  // 0x7fffffff
+      __ Cvtdq2ps(tmp2, tmp2);                  // 0x4f000000
       // tmp: convert (src-max_signed).
       // Positive overflow lanes -> 0x7FFFFFFF
       // Negative lanes -> 0
-      __ movaps(tmp, dst);
-      __ subps(tmp, tmp2);
-      __ cmpleps(tmp2, tmp);
-      __ cvttps2dq(tmp, tmp);
-      __ pxor(tmp, tmp2);
-      __ pxor(tmp2, tmp2);
-      __ pmaxsd(tmp, tmp2);
+      __ Movaps(tmp, dst);
+      __ Subps(tmp, tmp2);
+      __ Cmpleps(tmp2, tmp);
+      __ Cvttps2dq(tmp, tmp);
+      __ Pxor(tmp, tmp2);
+      __ Pxor(tmp2, tmp2);
+      __ Pmaxsd(tmp, tmp2);
       // convert. Overflow lanes above max_signed will be 0x80000000
-      __ cvttps2dq(dst, dst);
+      __ Cvttps2dq(dst, dst);
       // Add (src-max_signed) for overflow lanes.
-      __ paddd(dst, tmp);
+      __ Paddd(dst, tmp);
       break;
     }
     case kX64I32x4UConvertI16x8Low: {
@@ -3051,12 +3048,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I32x4ShrU: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 32.
-      __ andq(shift, Immediate(31));
-      __ Movq(tmp, shift);
-      __ Psrld(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^5.
+      ASSEMBLE_SIMD_SHIFT(Psrld, 5);
       break;
     }
     case kX64I32x4MinU: {
@@ -3088,37 +3081,38 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ Pcmpeqd(dst, src);
       break;
     }
+    case kX64I32x4Abs: {
+      __ Pabsd(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kX64S128Zero: {
       XMMRegister dst = i.OutputSimd128Register();
-      __ xorps(dst, dst);
+      __ Xorps(dst, dst);
       break;
     }
     case kX64I16x8Splat: {
       XMMRegister dst = i.OutputSimd128Register();
       if (HasRegisterInput(instr, 0)) {
-        __ movd(dst, i.InputRegister(0));
+        __ Movd(dst, i.InputRegister(0));
       } else {
-        __ movd(dst, i.InputOperand(0));
+        __ Movd(dst, i.InputOperand(0));
       }
-      __ pshuflw(dst, dst, 0x0);
-      __ pshufd(dst, dst, 0x0);
+      __ Pshuflw(dst, dst, static_cast<uint8_t>(0x0));
+      __ Pshufd(dst, dst, static_cast<uint8_t>(0x0));
       break;
     }
     case kX64I16x8ExtractLaneU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       Register dst = i.OutputRegister();
       __ Pextrw(dst, i.InputSimd128Register(0), i.InputInt8(1));
       break;
     }
     case kX64I16x8ExtractLaneS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       Register dst = i.OutputRegister();
       __ Pextrw(dst, i.InputSimd128Register(0), i.InputInt8(1));
       __ movsxwl(dst, dst);
       break;
     }
     case kX64I16x8ReplaceLane: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       if (HasRegisterInput(instr, 2)) {
         __ Pinsrw(i.OutputSimd128Register(), i.InputRegister(2),
                   i.InputInt8(1));
@@ -3138,103 +3132,88 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I16x8Neg: {
-      CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(0);
       if (dst == src) {
-        __ pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ psignw(dst, kScratchDoubleReg);
+        __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
+        __ Psignw(dst, kScratchDoubleReg);
       } else {
-        __ pxor(dst, dst);
-        __ psubw(dst, src);
+        __ Pxor(dst, dst);
+        __ Psubw(dst, src);
       }
       break;
     }
     case kX64I16x8Shl: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ andq(shift, Immediate(15));
-      __ movq(tmp, shift);
-      __ psllw(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^4.
+      ASSEMBLE_SIMD_SHIFT(Psllw, 4);
       break;
     }
     case kX64I16x8ShrS: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ andq(shift, Immediate(15));
-      __ movq(tmp, shift);
-      __ psraw(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^4.
+      ASSEMBLE_SIMD_SHIFT(Psraw, 4);
       break;
     }
     case kX64I16x8SConvertI32x4: {
       DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      __ packssdw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Packssdw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8Add: {
-      __ paddw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Paddw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8AddSaturateS: {
-      __ paddsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Paddsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8AddHoriz: {
-      CpuFeatureScope sse_scope(tasm(), SSSE3);
-      __ phaddw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Phaddw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8Sub: {
-      __ psubw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8SubSaturateS: {
-      __ psubsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8Mul: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmullw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pmullw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8MinS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pminsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pminsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8MaxS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmaxsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pmaxsw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8Eq: {
-      __ pcmpeqw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpeqw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8Ne: {
       XMMRegister tmp = i.TempSimd128Register(0);
-      __ pcmpeqw(i.OutputSimd128Register(), i.InputSimd128Register(1));
-      __ pcmpeqw(tmp, tmp);
-      __ pxor(i.OutputSimd128Register(), tmp);
+      __ Pcmpeqw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpeqw(tmp, tmp);
+      __ Pxor(i.OutputSimd128Register(), tmp);
       break;
     }
     case kX64I16x8GtS: {
-      __ pcmpgtw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpgtw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8GeS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
-      __ pminsw(dst, src);
-      __ pcmpeqw(dst, src);
+      __ Pminsw(dst, src);
+      __ Pcmpeqw(dst, src);
       break;
     }
     case kX64I16x8UConvertI8x16Low: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmovzxbw(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      __ Pmovzxbw(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
     }
     case kX64I16x8UConvertI8x16High: {
@@ -3244,63 +3223,57 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I16x8ShrU: {
-      XMMRegister tmp = i.TempSimd128Register(0);
-      Register shift = i.InputRegister(1);
-      // Take shift value modulo 16.
-      __ andq(shift, Immediate(15));
-      __ movq(tmp, shift);
-      __ psrlw(i.OutputSimd128Register(), tmp);
+      // Take shift value modulo 2^4.
+      ASSEMBLE_SIMD_SHIFT(Psrlw, 4);
       break;
     }
     case kX64I16x8UConvertI32x4: {
       DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ packusdw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Packusdw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8AddSaturateU: {
-      __ paddusw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Paddusw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8SubSaturateU: {
-      __ psubusw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubusw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8MinU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pminuw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pminuw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8MaxU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmaxuw(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pmaxuw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I16x8GtU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
       XMMRegister tmp = i.TempSimd128Register(0);
-      __ pmaxuw(dst, src);
-      __ pcmpeqw(dst, src);
-      __ pcmpeqw(tmp, tmp);
-      __ pxor(dst, tmp);
+      __ Pmaxuw(dst, src);
+      __ Pcmpeqw(dst, src);
+      __ Pcmpeqw(tmp, tmp);
+      __ Pxor(dst, tmp);
       break;
     }
     case kX64I16x8GeU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
-      __ pminuw(dst, src);
-      __ pcmpeqw(dst, src);
+      __ Pminuw(dst, src);
+      __ Pcmpeqw(dst, src);
       break;
     }
     case kX64I16x8RoundingAverageU: {
       __ Pavgw(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
+    case kX64I16x8Abs: {
+      __ Pabsw(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kX64I8x16Splat: {
-      CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
       if (HasRegisterInput(instr, 0)) {
         __ Movd(dst, i.InputRegister(0));
@@ -3312,20 +3285,17 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I8x16ExtractLaneU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       Register dst = i.OutputRegister();
       __ Pextrb(dst, i.InputSimd128Register(0), i.InputInt8(1));
       break;
     }
     case kX64I8x16ExtractLaneS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       Register dst = i.OutputRegister();
       __ Pextrb(dst, i.InputSimd128Register(0), i.InputInt8(1));
       __ movsxbl(dst, dst);
       break;
     }
     case kX64I8x16ReplaceLane: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       if (HasRegisterInput(instr, 2)) {
         __ Pinsrb(i.OutputSimd128Register(), i.InputRegister(2),
                   i.InputInt8(1));
@@ -3336,77 +3306,98 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
     case kX64I8x16SConvertI16x8: {
       DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      __ packsswb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Packsswb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16Neg: {
-      CpuFeatureScope sse_scope(tasm(), SSSE3);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(0);
       if (dst == src) {
-        __ pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
-        __ psignb(dst, kScratchDoubleReg);
+        __ Pcmpeqd(kScratchDoubleReg, kScratchDoubleReg);
+        __ Psignb(dst, kScratchDoubleReg);
       } else {
-        __ pxor(dst, dst);
-        __ psubb(dst, src);
+        __ Pxor(dst, dst);
+        __ Psubb(dst, src);
       }
       break;
     }
     case kX64I8x16Shl: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      // Temp registers for shift mask andadditional moves to XMM registers.
+      // Temp registers for shift mask and additional moves to XMM registers.
       Register tmp = i.ToRegister(instr->TempAt(0));
       XMMRegister tmp_simd = i.TempSimd128Register(1);
-      Register shift = i.InputRegister(1);
-      // Mask off the unwanted bits before word-shifting.
-      __ pcmpeqw(kScratchDoubleReg, kScratchDoubleReg);
-      // Take shift value modulo 8.
-      __ andq(shift, Immediate(7));
-      __ movq(tmp, shift);
-      __ addq(tmp, Immediate(8));
-      __ movq(tmp_simd, tmp);
-      __ psrlw(kScratchDoubleReg, tmp_simd);
-      __ packuswb(kScratchDoubleReg, kScratchDoubleReg);
-      __ pand(dst, kScratchDoubleReg);
-      __ movq(tmp_simd, shift);
-      __ psllw(dst, tmp_simd);
+      if (HasImmediateInput(instr, 1)) {
+        // Perform 16-bit shift, then mask away low bits.
+        uint8_t shift = i.InputInt3(1);
+        __ Psllw(dst, static_cast<byte>(shift));
+
+        uint8_t bmask = static_cast<uint8_t>(0xff << shift);
+        uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
+        __ movl(tmp, Immediate(mask));
+        __ Movd(tmp_simd, tmp);
+        __ Pshufd(tmp_simd, tmp_simd, static_cast<uint8_t>(0));
+        __ Pand(dst, tmp_simd);
+      } else {
+        Register shift = i.InputRegister(1);
+        // Mask off the unwanted bits before word-shifting.
+        __ Pcmpeqw(kScratchDoubleReg, kScratchDoubleReg);
+        // Take shift value modulo 8.
+        __ andq(shift, Immediate(7));
+        __ movq(tmp, shift);
+        __ addq(tmp, Immediate(8));
+        __ Movq(tmp_simd, tmp);
+        __ Psrlw(kScratchDoubleReg, tmp_simd);
+        __ Packuswb(kScratchDoubleReg, kScratchDoubleReg);
+        __ Pand(dst, kScratchDoubleReg);
+        __ Movq(tmp_simd, shift);
+        __ Psllw(dst, tmp_simd);
+      }
       break;
     }
     case kX64I8x16ShrS: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      // Temp registers for shift mask andadditional moves to XMM registers.
-      Register tmp = i.ToRegister(instr->TempAt(0));
-      XMMRegister tmp_simd = i.TempSimd128Register(1);
-      // Unpack the bytes into words, do arithmetic shifts, and repack.
-      __ punpckhbw(kScratchDoubleReg, dst);
-      __ punpcklbw(dst, dst);
-      // Prepare shift value
-      __ movq(tmp, i.InputRegister(1));
-      // Take shift value modulo 8.
-      __ andq(tmp, Immediate(7));
-      __ addq(tmp, Immediate(8));
-      __ movq(tmp_simd, tmp);
-      __ psraw(kScratchDoubleReg, tmp_simd);
-      __ psraw(dst, tmp_simd);
-      __ packsswb(dst, kScratchDoubleReg);
+      if (HasImmediateInput(instr, 1)) {
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        uint8_t shift = i.InputInt3(1) + 8;
+        __ Psraw(kScratchDoubleReg, shift);
+        __ Psraw(dst, shift);
+        __ Packsswb(dst, kScratchDoubleReg);
+      } else {
+        // Temp registers for shift mask andadditional moves to XMM registers.
+        Register tmp = i.ToRegister(instr->TempAt(0));
+        XMMRegister tmp_simd = i.TempSimd128Register(1);
+        // Unpack the bytes into words, do arithmetic shifts, and repack.
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        // Prepare shift value
+        __ movq(tmp, i.InputRegister(1));
+        // Take shift value modulo 8.
+        __ andq(tmp, Immediate(7));
+        __ addq(tmp, Immediate(8));
+        __ Movq(tmp_simd, tmp);
+        __ Psraw(kScratchDoubleReg, tmp_simd);
+        __ Psraw(dst, tmp_simd);
+        __ Packsswb(dst, kScratchDoubleReg);
+      }
       break;
     }
     case kX64I8x16Add: {
-      __ paddb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Paddb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16AddSaturateS: {
-      __ paddsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Paddsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16Sub: {
-      __ psubb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16SubSaturateS: {
-      __ psubsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16Mul: {
@@ -3419,66 +3410,62 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // right= BBbb BBbb ... BBbb BBbb
       // t = 00AA 00AA ... 00AA 00AA
       // s = 00BB 00BB ... 00BB 00BB
-      __ movaps(tmp, dst);
-      __ movaps(kScratchDoubleReg, right);
-      __ psrlw(tmp, 8);
-      __ psrlw(kScratchDoubleReg, 8);
+      __ Movaps(tmp, dst);
+      __ Movaps(kScratchDoubleReg, right);
+      __ Psrlw(tmp, static_cast<byte>(8));
+      __ Psrlw(kScratchDoubleReg, static_cast<byte>(8));
       // dst = left * 256
-      __ psllw(dst, 8);
+      __ Psllw(dst, static_cast<byte>(8));
       // t = I16x8Mul(t, s)
       //    => __PP __PP ...  __PP  __PP
-      __ pmullw(tmp, kScratchDoubleReg);
+      __ Pmullw(tmp, kScratchDoubleReg);
       // dst = I16x8Mul(left * 256, right)
       //    => pp__ pp__ ...  pp__  pp__
-      __ pmullw(dst, right);
+      __ Pmullw(dst, right);
       // t = I16x8Shl(t, 8)
       //    => PP00 PP00 ...  PP00  PP00
-      __ psllw(tmp, 8);
+      __ Psllw(tmp, static_cast<byte>(8));
       // dst = I16x8Shr(dst, 8)
       //    => 00pp 00pp ...  00pp  00pp
-      __ psrlw(dst, 8);
+      __ Psrlw(dst, static_cast<byte>(8));
       // dst = I16x8Or(dst, t)
       //    => PPpp PPpp ...  PPpp  PPpp
-      __ por(dst, tmp);
+      __ Por(dst, tmp);
       break;
     }
     case kX64I8x16MinS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pminsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pminsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16MaxS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmaxsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pmaxsb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16Eq: {
-      __ pcmpeqb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpeqb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16Ne: {
       XMMRegister tmp = i.TempSimd128Register(0);
-      __ pcmpeqb(i.OutputSimd128Register(), i.InputSimd128Register(1));
-      __ pcmpeqb(tmp, tmp);
-      __ pxor(i.OutputSimd128Register(), tmp);
+      __ Pcmpeqb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpeqb(tmp, tmp);
+      __ Pxor(i.OutputSimd128Register(), tmp);
       break;
     }
     case kX64I8x16GtS: {
-      __ pcmpgtb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pcmpgtb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16GeS: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
-      __ pminsb(dst, src);
-      __ pcmpeqb(dst, src);
+      __ Pminsb(dst, src);
+      __ Pcmpeqb(dst, src);
       break;
     }
     case kX64I8x16UConvertI16x8: {
       DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ packuswb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Packuswb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16ShrU: {
@@ -3488,17 +3475,30 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       // Temp registers for shift mask andadditional moves to XMM registers.
       Register tmp = i.ToRegister(instr->TempAt(0));
       XMMRegister tmp_simd = i.TempSimd128Register(1);
-      __ punpckhbw(kScratchDoubleReg, dst);
-      __ punpcklbw(dst, dst);
-      // Prepare shift value
-      __ movq(tmp, i.InputRegister(1));
-      // Take shift value modulo 8.
-      __ andq(tmp, Immediate(7));
-      __ addq(tmp, Immediate(8));
-      __ movq(tmp_simd, tmp);
-      __ psrlw(kScratchDoubleReg, tmp_simd);
-      __ psrlw(dst, tmp_simd);
-      __ packuswb(dst, kScratchDoubleReg);
+      if (HasImmediateInput(instr, 1)) {
+        // Perform 16-bit shift, then mask away high bits.
+        uint8_t shift = i.InputInt3(1);
+        __ Psrlw(dst, static_cast<byte>(shift));
+
+        uint8_t bmask = 0xff >> shift;
+        uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
+        __ movl(tmp, Immediate(mask));
+        __ Movd(tmp_simd, tmp);
+        __ Pshufd(tmp_simd, tmp_simd, static_cast<byte>(0));
+        __ Pand(dst, tmp_simd);
+      } else {
+        __ Punpckhbw(kScratchDoubleReg, dst);
+        __ Punpcklbw(dst, dst);
+        // Prepare shift value
+        __ movq(tmp, i.InputRegister(1));
+        // Take shift value modulo 8.
+        __ andq(tmp, Immediate(7));
+        __ addq(tmp, Immediate(8));
+        __ Movq(tmp_simd, tmp);
+        __ Psrlw(kScratchDoubleReg, tmp_simd);
+        __ Psrlw(dst, tmp_simd);
+        __ Packuswb(dst, kScratchDoubleReg);
+      }
       break;
     }
     case kX64I8x16AddSaturateU: {
@@ -3506,64 +3506,64 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64I8x16SubSaturateU: {
-      __ psubusb(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Psubusb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16MinU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pminub(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pminub(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16MaxU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
-      __ pmaxub(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pmaxub(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64I8x16GtU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
       XMMRegister tmp = i.TempSimd128Register(0);
-      __ pmaxub(dst, src);
-      __ pcmpeqb(dst, src);
-      __ pcmpeqb(tmp, tmp);
-      __ pxor(dst, tmp);
+      __ Pmaxub(dst, src);
+      __ Pcmpeqb(dst, src);
+      __ Pcmpeqb(tmp, tmp);
+      __ Pxor(dst, tmp);
       break;
     }
     case kX64I8x16GeU: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(1);
-      __ pminub(dst, src);
-      __ pcmpeqb(dst, src);
+      __ Pminub(dst, src);
+      __ Pcmpeqb(dst, src);
       break;
     }
     case kX64I8x16RoundingAverageU: {
       __ Pavgb(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
+    case kX64I8x16Abs: {
+      __ Pabsb(i.OutputSimd128Register(), i.InputSimd128Register(0));
+      break;
+    }
     case kX64S128And: {
-      __ pand(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pand(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64S128Or: {
-      __ por(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Por(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64S128Xor: {
-      __ pxor(i.OutputSimd128Register(), i.InputSimd128Register(1));
+      __ Pxor(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
     case kX64S128Not: {
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src = i.InputSimd128Register(0);
       if (dst == src) {
-        __ movaps(kScratchDoubleReg, dst);
-        __ pcmpeqd(dst, dst);
-        __ pxor(dst, kScratchDoubleReg);
+        __ Movaps(kScratchDoubleReg, dst);
+        __ Pcmpeqd(dst, dst);
+        __ Pxor(dst, kScratchDoubleReg);
       } else {
-        __ pcmpeqd(dst, dst);
-        __ pxor(dst, src);
+        __ Pcmpeqd(dst, dst);
+        __ Pxor(dst, src);
       }
 
       break;
@@ -3586,7 +3586,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64S8x16Swizzle: {
-      CpuFeatureScope sse_scope(tasm(), SSSE3);
       DCHECK_EQ(i.OutputSimd128Register(), i.InputSimd128Register(0));
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister mask = i.TempSimd128Register(0);
@@ -3718,129 +3717,126 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     }
     case kX64S32x4Swizzle: {
       DCHECK_EQ(2, instr->InputCount());
-      ASSEMBLE_SIMD_IMM_INSTR(pshufd, i.OutputSimd128Register(), 0,
-                              i.InputInt8(1));
+      ASSEMBLE_SIMD_IMM_INSTR(Pshufd, i.OutputSimd128Register(), 0,
+                              i.InputUint8(1));
       break;
     }
     case kX64S32x4Shuffle: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       DCHECK_EQ(4, instr->InputCount());  // Swizzles should be handled above.
-      int8_t shuffle = i.InputInt8(2);
+      uint8_t shuffle = i.InputUint8(2);
       DCHECK_NE(0xe4, shuffle);  // A simple blend should be handled below.
-      ASSEMBLE_SIMD_IMM_INSTR(pshufd, kScratchDoubleReg, 1, shuffle);
-      ASSEMBLE_SIMD_IMM_INSTR(pshufd, i.OutputSimd128Register(), 0, shuffle);
-      __ pblendw(i.OutputSimd128Register(), kScratchDoubleReg, i.InputInt8(3));
+      ASSEMBLE_SIMD_IMM_INSTR(Pshufd, kScratchDoubleReg, 1, shuffle);
+      ASSEMBLE_SIMD_IMM_INSTR(Pshufd, i.OutputSimd128Register(), 0, shuffle);
+      __ Pblendw(i.OutputSimd128Register(), kScratchDoubleReg, i.InputUint8(3));
       break;
     }
     case kX64S16x8Blend: {
-      ASSEMBLE_SIMD_IMM_SHUFFLE(pblendw, SSE4_1, i.InputInt8(2));
+      ASSEMBLE_SIMD_IMM_SHUFFLE(Pblendw, i.InputUint8(2));
       break;
     }
     case kX64S16x8HalfShuffle1: {
       XMMRegister dst = i.OutputSimd128Register();
-      ASSEMBLE_SIMD_IMM_INSTR(pshuflw, dst, 0, i.InputInt8(1));
-      __ pshufhw(dst, dst, i.InputInt8(2));
+      ASSEMBLE_SIMD_IMM_INSTR(Pshuflw, dst, 0, i.InputUint8(1));
+      __ Pshufhw(dst, dst, i.InputUint8(2));
       break;
     }
     case kX64S16x8HalfShuffle2: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
-      ASSEMBLE_SIMD_IMM_INSTR(pshuflw, kScratchDoubleReg, 1, i.InputInt8(2));
-      __ pshufhw(kScratchDoubleReg, kScratchDoubleReg, i.InputInt8(3));
-      ASSEMBLE_SIMD_IMM_INSTR(pshuflw, dst, 0, i.InputInt8(2));
-      __ pshufhw(dst, dst, i.InputInt8(3));
-      __ pblendw(dst, kScratchDoubleReg, i.InputInt8(4));
+      ASSEMBLE_SIMD_IMM_INSTR(Pshuflw, kScratchDoubleReg, 1, i.InputUint8(2));
+      __ Pshufhw(kScratchDoubleReg, kScratchDoubleReg, i.InputUint8(3));
+      ASSEMBLE_SIMD_IMM_INSTR(Pshuflw, dst, 0, i.InputUint8(2));
+      __ Pshufhw(dst, dst, i.InputUint8(3));
+      __ Pblendw(dst, kScratchDoubleReg, i.InputUint8(4));
       break;
     }
     case kX64S8x16Alignr: {
-      ASSEMBLE_SIMD_IMM_SHUFFLE(palignr, SSSE3, i.InputInt8(2));
+      ASSEMBLE_SIMD_IMM_SHUFFLE(Palignr, i.InputUint8(2));
       break;
     }
     case kX64S16x8Dup: {
       XMMRegister dst = i.OutputSimd128Register();
-      int8_t lane = i.InputInt8(1) & 0x7;
-      int8_t lane4 = lane & 0x3;
-      int8_t half_dup = lane4 | (lane4 << 2) | (lane4 << 4) | (lane4 << 6);
+      uint8_t lane = i.InputInt8(1) & 0x7;
+      uint8_t lane4 = lane & 0x3;
+      uint8_t half_dup = lane4 | (lane4 << 2) | (lane4 << 4) | (lane4 << 6);
       if (lane < 4) {
-        ASSEMBLE_SIMD_IMM_INSTR(pshuflw, dst, 0, half_dup);
-        __ pshufd(dst, dst, 0);
+        ASSEMBLE_SIMD_IMM_INSTR(Pshuflw, dst, 0, half_dup);
+        __ Pshufd(dst, dst, static_cast<uint8_t>(0));
       } else {
-        ASSEMBLE_SIMD_IMM_INSTR(pshufhw, dst, 0, half_dup);
-        __ pshufd(dst, dst, 0xaa);
+        ASSEMBLE_SIMD_IMM_INSTR(Pshufhw, dst, 0, half_dup);
+        __ Pshufd(dst, dst, static_cast<uint8_t>(0xaa));
       }
       break;
     }
     case kX64S8x16Dup: {
       XMMRegister dst = i.OutputSimd128Register();
-      int8_t lane = i.InputInt8(1) & 0xf;
+      uint8_t lane = i.InputInt8(1) & 0xf;
       DCHECK_EQ(dst, i.InputSimd128Register(0));
       if (lane < 8) {
-        __ punpcklbw(dst, dst);
+        __ Punpcklbw(dst, dst);
       } else {
-        __ punpckhbw(dst, dst);
+        __ Punpckhbw(dst, dst);
       }
       lane &= 0x7;
-      int8_t lane4 = lane & 0x3;
-      int8_t half_dup = lane4 | (lane4 << 2) | (lane4 << 4) | (lane4 << 6);
+      uint8_t lane4 = lane & 0x3;
+      uint8_t half_dup = lane4 | (lane4 << 2) | (lane4 << 4) | (lane4 << 6);
       if (lane < 4) {
-        __ pshuflw(dst, dst, half_dup);
-        __ pshufd(dst, dst, 0);
+        __ Pshuflw(dst, dst, half_dup);
+        __ Pshufd(dst, dst, static_cast<uint8_t>(0));
       } else {
-        __ pshufhw(dst, dst, half_dup);
-        __ pshufd(dst, dst, 0xaa);
+        __ Pshufhw(dst, dst, half_dup);
+        __ Pshufd(dst, dst, static_cast<uint8_t>(0xaa));
       }
       break;
     }
     case kX64S64x2UnpackHigh:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpckhqdq);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpckhqdq);
       break;
     case kX64S32x4UnpackHigh:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpckhdq);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpckhdq);
       break;
     case kX64S16x8UnpackHigh:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpckhwd);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpckhwd);
       break;
     case kX64S8x16UnpackHigh:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpckhbw);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpckhbw);
       break;
     case kX64S64x2UnpackLow:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpcklqdq);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpcklqdq);
       break;
     case kX64S32x4UnpackLow:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpckldq);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpckldq);
       break;
     case kX64S16x8UnpackLow:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpcklwd);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpcklwd);
       break;
     case kX64S8x16UnpackLow:
-      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(punpcklbw);
+      ASSEMBLE_SIMD_PUNPCK_SHUFFLE(Punpcklbw);
       break;
     case kX64S16x8UnzipHigh: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src2 = dst;
       DCHECK_EQ(dst, i.InputSimd128Register(0));
       if (instr->InputCount() == 2) {
-        ASSEMBLE_SIMD_INSTR(movups, kScratchDoubleReg, 1);
-        __ psrld(kScratchDoubleReg, 16);
+        ASSEMBLE_SIMD_INSTR(Movups, kScratchDoubleReg, 1);
+        __ Psrld(kScratchDoubleReg, static_cast<byte>(16));
         src2 = kScratchDoubleReg;
       }
-      __ psrld(dst, 16);
-      __ packusdw(dst, src2);
+      __ Psrld(dst, static_cast<byte>(16));
+      __ Packusdw(dst, src2);
       break;
     }
     case kX64S16x8UnzipLow: {
-      CpuFeatureScope sse_scope(tasm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       XMMRegister src2 = dst;
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      __ pxor(kScratchDoubleReg, kScratchDoubleReg);
+      __ Pxor(kScratchDoubleReg, kScratchDoubleReg);
       if (instr->InputCount() == 2) {
-        ASSEMBLE_SIMD_IMM_INSTR(pblendw, kScratchDoubleReg, 1, 0x55);
+        ASSEMBLE_SIMD_IMM_INSTR(Pblendw, kScratchDoubleReg, 1,
+                                static_cast<uint8_t>(0x55));
         src2 = kScratchDoubleReg;
       }
-      __ pblendw(dst, kScratchDoubleReg, 0xaa);
-      __ packusdw(dst, src2);
+      __ Pblendw(dst, kScratchDoubleReg, static_cast<uint8_t>(0xaa));
+      __ Packusdw(dst, src2);
       break;
     }
     case kX64S8x16UnzipHigh: {
@@ -3848,12 +3844,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister src2 = dst;
       DCHECK_EQ(dst, i.InputSimd128Register(0));
       if (instr->InputCount() == 2) {
-        ASSEMBLE_SIMD_INSTR(movups, kScratchDoubleReg, 1);
-        __ psrlw(kScratchDoubleReg, 8);
+        ASSEMBLE_SIMD_INSTR(Movups, kScratchDoubleReg, 1);
+        __ Psrlw(kScratchDoubleReg, static_cast<byte>(8));
         src2 = kScratchDoubleReg;
       }
-      __ psrlw(dst, 8);
-      __ packuswb(dst, src2);
+      __ Psrlw(dst, static_cast<byte>(8));
+      __ Packuswb(dst, src2);
       break;
     }
     case kX64S8x16UnzipLow: {
@@ -3861,44 +3857,44 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       XMMRegister src2 = dst;
       DCHECK_EQ(dst, i.InputSimd128Register(0));
       if (instr->InputCount() == 2) {
-        ASSEMBLE_SIMD_INSTR(movups, kScratchDoubleReg, 1);
-        __ psllw(kScratchDoubleReg, 8);
-        __ psrlw(kScratchDoubleReg, 8);
+        ASSEMBLE_SIMD_INSTR(Movups, kScratchDoubleReg, 1);
+        __ Psllw(kScratchDoubleReg, static_cast<byte>(8));
+        __ Psrlw(kScratchDoubleReg, static_cast<byte>(8));
         src2 = kScratchDoubleReg;
       }
-      __ psllw(dst, 8);
-      __ psrlw(dst, 8);
-      __ packuswb(dst, src2);
+      __ Psllw(dst, static_cast<byte>(8));
+      __ Psrlw(dst, static_cast<byte>(8));
+      __ Packuswb(dst, src2);
       break;
     }
     case kX64S8x16TransposeLow: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      __ psllw(dst, 8);
+      __ Psllw(dst, static_cast<byte>(8));
       if (instr->InputCount() == 1) {
-        __ movups(kScratchDoubleReg, dst);
+        __ Movups(kScratchDoubleReg, dst);
       } else {
         DCHECK_EQ(2, instr->InputCount());
-        ASSEMBLE_SIMD_INSTR(movups, kScratchDoubleReg, 1);
-        __ psllw(kScratchDoubleReg, 8);
+        ASSEMBLE_SIMD_INSTR(Movups, kScratchDoubleReg, 1);
+        __ Psllw(kScratchDoubleReg, static_cast<byte>(8));
       }
-      __ psrlw(dst, 8);
-      __ por(dst, kScratchDoubleReg);
+      __ Psrlw(dst, static_cast<byte>(8));
+      __ Por(dst, kScratchDoubleReg);
       break;
     }
     case kX64S8x16TransposeHigh: {
       XMMRegister dst = i.OutputSimd128Register();
       DCHECK_EQ(dst, i.InputSimd128Register(0));
-      __ psrlw(dst, 8);
+      __ Psrlw(dst, static_cast<byte>(8));
       if (instr->InputCount() == 1) {
-        __ movups(kScratchDoubleReg, dst);
+        __ Movups(kScratchDoubleReg, dst);
       } else {
         DCHECK_EQ(2, instr->InputCount());
-        ASSEMBLE_SIMD_INSTR(movups, kScratchDoubleReg, 1);
-        __ psrlw(kScratchDoubleReg, 8);
+        ASSEMBLE_SIMD_INSTR(Movups, kScratchDoubleReg, 1);
+        __ Psrlw(kScratchDoubleReg, static_cast<byte>(8));
       }
-      __ psllw(kScratchDoubleReg, 8);
-      __ por(dst, kScratchDoubleReg);
+      __ Psllw(kScratchDoubleReg, static_cast<byte>(8));
+      __ Por(dst, kScratchDoubleReg);
       break;
     }
     case kX64S8x8Reverse:
@@ -3909,14 +3905,14 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       DCHECK_EQ(dst, i.InputSimd128Register(0));
       if (arch_opcode != kX64S8x2Reverse) {
         // First shuffle words into position.
-        int8_t shuffle_mask = arch_opcode == kX64S8x4Reverse ? 0xB1 : 0x1B;
-        __ pshuflw(dst, dst, shuffle_mask);
-        __ pshufhw(dst, dst, shuffle_mask);
+        uint8_t shuffle_mask = arch_opcode == kX64S8x4Reverse ? 0xB1 : 0x1B;
+        __ Pshuflw(dst, dst, shuffle_mask);
+        __ Pshufhw(dst, dst, shuffle_mask);
       }
-      __ movaps(kScratchDoubleReg, dst);
-      __ psrlw(kScratchDoubleReg, 8);
-      __ psllw(dst, 8);
-      __ por(dst, kScratchDoubleReg);
+      __ Movaps(kScratchDoubleReg, dst);
+      __ Psrlw(kScratchDoubleReg, static_cast<byte>(8));
+      __ Psllw(dst, static_cast<byte>(8));
+      __ Por(dst, kScratchDoubleReg);
       break;
     }
     case kX64S1x2AnyTrue:
@@ -3926,11 +3922,10 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       CpuFeatureScope sse_scope(tasm(), SSE4_1);
       Register dst = i.OutputRegister();
       XMMRegister src = i.InputSimd128Register(0);
-      Register tmp = i.TempRegister(0);
-      __ xorq(tmp, tmp);
-      __ movq(dst, Immediate(1));
-      __ ptest(src, src);
-      __ cmovq(zero, dst, tmp);
+
+      __ xorq(dst, dst);
+      __ Ptest(src, src);
+      __ setcc(not_equal, dst);
       break;
     }
     // Need to split up all the different lane structures because the
@@ -3942,15 +3937,15 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kX64S1x4AllTrue: {
-      ASSEMBLE_SIMD_ALL_TRUE(pcmpeqd);
+      ASSEMBLE_SIMD_ALL_TRUE(Pcmpeqd);
       break;
     }
     case kX64S1x8AllTrue: {
-      ASSEMBLE_SIMD_ALL_TRUE(pcmpeqw);
+      ASSEMBLE_SIMD_ALL_TRUE(Pcmpeqw);
       break;
     }
     case kX64S1x16AllTrue: {
-      ASSEMBLE_SIMD_ALL_TRUE(pcmpeqb);
+      ASSEMBLE_SIMD_ALL_TRUE(Pcmpeqb);
       break;
     }
     case kWord32AtomicExchangeInt8: {
@@ -4065,6 +4060,8 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kX64Word64AtomicCompareExchangeUint32: {
       __ lock();
       __ cmpxchgl(i.MemoryOperand(2), i.InputRegister(1));
+      // Zero-extend the 32 bit value to 64 bit.
+      __ movl(rax, rax);
       break;
     }
     case kX64Word64AtomicCompareExchangeUint64: {
@@ -4133,6 +4130,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
 #undef ASSEMBLE_SIMD_PUNPCK_SHUFFLE
 #undef ASSEMBLE_SIMD_IMM_SHUFFLE
 #undef ASSEMBLE_SIMD_ALL_TRUE
+#undef ASSEMBLE_SIMD_SHIFT
 
 namespace {
 
@@ -4297,16 +4295,6 @@ void CodeGenerator::AssembleArchBinarySearchSwitch(Instruction* instr) {
                                       cases.data() + cases.size());
 }
 
-void CodeGenerator::AssembleArchLookupSwitch(Instruction* instr) {
-  X64OperandConverter i(this, instr);
-  Register input = i.InputRegister(0);
-  for (size_t index = 2; index < instr->InputCount(); index += 2) {
-    __ cmpl(input, Immediate(i.InputInt32(index + 0)));
-    __ j(equal, GetLabel(i.InputRpo(index + 1)));
-  }
-  AssembleArchJump(i.InputRpo(1));
-}
-
 void CodeGenerator::AssembleArchTableSwitch(Instruction* instr) {
   X64OperandConverter i(this, instr);
   Register input = i.InputRegister(0);
@@ -4376,7 +4364,7 @@ void CodeGenerator::AssembleConstructFrame() {
         __ pushq(kWasmInstanceRegister);
       } else if (call_descriptor->IsWasmImportWrapper() ||
                  call_descriptor->IsWasmCapiFunction()) {
-        // WASM import wrappers are passed a tuple in the place of the instance.
+        // Wasm import wrappers are passed a tuple in the place of the instance.
         // Unpack the tuple into the instance and the target callable.
         // This must be done here in the codegen because it cannot be expressed
         // properly in the graph.
diff --git a/deps/v8/src/compiler/backend/x64/instruction-codes-x64.h b/deps/v8/src/compiler/backend/x64/instruction-codes-x64.h
index 64e87430b7..be5ac0d6c3 100644
--- a/deps/v8/src/compiler/backend/x64/instruction-codes-x64.h
+++ b/deps/v8/src/compiler/backend/x64/instruction-codes-x64.h
@@ -240,6 +240,7 @@ namespace compiler {
   V(X64I32x4MaxU)                         \
   V(X64I32x4GtU)                          \
   V(X64I32x4GeU)                          \
+  V(X64I32x4Abs)                          \
   V(X64I16x8Splat)                        \
   V(X64I16x8ExtractLaneU)                 \
   V(X64I16x8ExtractLaneS)                 \
@@ -273,6 +274,7 @@ namespace compiler {
   V(X64I16x8GtU)                          \
   V(X64I16x8GeU)                          \
   V(X64I16x8RoundingAverageU)             \
+  V(X64I16x8Abs)                          \
   V(X64I8x16Splat)                        \
   V(X64I8x16ExtractLaneU)                 \
   V(X64I8x16ExtractLaneS)                 \
@@ -301,6 +303,7 @@ namespace compiler {
   V(X64I8x16GtU)                          \
   V(X64I8x16GeU)                          \
   V(X64I8x16RoundingAverageU)             \
+  V(X64I8x16Abs)                          \
   V(X64S128Zero)                          \
   V(X64S128Not)                           \
   V(X64S128And)                           \
diff --git a/deps/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc b/deps/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
index 6563ab5f7c..f4a74a4050 100644
--- a/deps/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
+++ b/deps/v8/src/compiler/backend/x64/instruction-scheduler-x64.cc
@@ -212,6 +212,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I32x4MaxU:
     case kX64I32x4GtU:
     case kX64I32x4GeU:
+    case kX64I32x4Abs:
     case kX64I16x8Splat:
     case kX64I16x8ExtractLaneU:
     case kX64I16x8ExtractLaneS:
@@ -245,6 +246,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I16x8GtU:
     case kX64I16x8GeU:
     case kX64I16x8RoundingAverageU:
+    case kX64I16x8Abs:
     case kX64I8x16Splat:
     case kX64I8x16ExtractLaneU:
     case kX64I8x16ExtractLaneS:
@@ -273,6 +275,7 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kX64I8x16GtU:
     case kX64I8x16GeU:
     case kX64I8x16RoundingAverageU:
+    case kX64I8x16Abs:
     case kX64S128And:
     case kX64S128Or:
     case kX64S128Xor:
diff --git a/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc b/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
index 1046ab9a06..392b207c8e 100644
--- a/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
+++ b/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
@@ -2212,7 +2212,7 @@ void InstructionSelector::VisitSwitch(Node* node, const SwitchInfo& sw) {
   X64OperandGenerator g(this);
   InstructionOperand value_operand = g.UseRegister(node->InputAt(0));
 
-  // Emit either ArchTableSwitch or ArchLookupSwitch.
+  // Emit either ArchTableSwitch or ArchBinarySearchSwitch.
   if (enable_switch_jump_table_ == kEnableSwitchJumpTable) {
     static const size_t kMaxTableSwitchValueRange = 2 << 16;
     size_t table_space_cost = 4 + sw.value_range();
@@ -2729,12 +2729,15 @@ VISIT_ATOMIC_BINOP(Xor)
   V(I32x4Neg)               \
   V(I32x4UConvertI16x8Low)  \
   V(I32x4UConvertI16x8High) \
+  V(I32x4Abs)               \
   V(I16x8SConvertI8x16Low)  \
   V(I16x8SConvertI8x16High) \
   V(I16x8Neg)               \
   V(I16x8UConvertI8x16Low)  \
   V(I16x8UConvertI8x16High) \
+  V(I16x8Abs)               \
   V(I8x16Neg)               \
+  V(I8x16Abs)               \
   V(S128Not)
 
 #define SIMD_SHIFT_OPCODES(V) \
@@ -2749,7 +2752,6 @@ VISIT_ATOMIC_BINOP(Xor)
 
 #define SIMD_NARROW_SHIFT_OPCODES(V) \
   V(I8x16Shl)                        \
-  V(I8x16ShrS)                       \
   V(I8x16ShrU)
 
 #define SIMD_ANYTRUE_LIST(V) \
@@ -2806,13 +2808,18 @@ SIMD_VISIT_EXTRACT_LANE(I8x16, S)
 SIMD_TYPES(VISIT_SIMD_REPLACE_LANE)
 #undef VISIT_SIMD_REPLACE_LANE
 
-#define VISIT_SIMD_SHIFT(Opcode)                                          \
-  void InstructionSelector::Visit##Opcode(Node* node) {                   \
-    X64OperandGenerator g(this);                                          \
-    InstructionOperand temps[] = {g.TempSimd128Register()};               \
-    Emit(kX64##Opcode, g.DefineSameAsFirst(node),                         \
-         g.UseUniqueRegister(node->InputAt(0)),                           \
-         g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps); \
+#define VISIT_SIMD_SHIFT(Opcode)                                               \
+  void InstructionSelector::Visit##Opcode(Node* node) {                        \
+    X64OperandGenerator g(this);                                               \
+    if (g.CanBeImmediate(node->InputAt(1))) {                                  \
+      Emit(kX64##Opcode, g.DefineSameAsFirst(node),                            \
+           g.UseRegister(node->InputAt(0)), g.UseImmediate(node->InputAt(1))); \
+    } else {                                                                   \
+      InstructionOperand temps[] = {g.TempSimd128Register()};                  \
+      Emit(kX64##Opcode, g.DefineSameAsFirst(node),                            \
+           g.UseUniqueRegister(node->InputAt(0)),                              \
+           g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps);    \
+    }                                                                          \
   }
 SIMD_SHIFT_OPCODES(VISIT_SIMD_SHIFT)
 #undef VISIT_SIMD_SHIFT
@@ -2822,9 +2829,15 @@ SIMD_SHIFT_OPCODES(VISIT_SIMD_SHIFT)
   void InstructionSelector::Visit##Opcode(Node* node) {                       \
     X64OperandGenerator g(this);                                              \
     InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()}; \
-    Emit(kX64##Opcode, g.DefineSameAsFirst(node),                             \
-         g.UseUniqueRegister(node->InputAt(0)),                               \
-         g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps);     \
+    if (g.CanBeImmediate(node->InputAt(1))) {                                 \
+      Emit(kX64##Opcode, g.DefineSameAsFirst(node),                           \
+           g.UseRegister(node->InputAt(0)), g.UseImmediate(node->InputAt(1)), \
+           arraysize(temps), temps);                                          \
+    } else {                                                                  \
+      Emit(kX64##Opcode, g.DefineSameAsFirst(node),                           \
+           g.UseUniqueRegister(node->InputAt(0)),                             \
+           g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps);   \
+    }                                                                         \
   }
 SIMD_NARROW_SHIFT_OPCODES(VISIT_SIMD_NARROW_SHIFT)
 #undef VISIT_SIMD_NARROW_SHIFT
@@ -2862,23 +2875,22 @@ SIMD_BINOP_ONE_TEMP_LIST(VISIT_SIMD_BINOP_ONE_TEMP)
 #undef VISIT_SIMD_BINOP_ONE_TEMP
 #undef SIMD_BINOP_ONE_TEMP_LIST
 
-#define VISIT_SIMD_ANYTRUE(Opcode)                                        \
-  void InstructionSelector::Visit##Opcode(Node* node) {                   \
-    X64OperandGenerator g(this);                                          \
-    InstructionOperand temps[] = {g.TempRegister()};                      \
-    Emit(kX64##Opcode, g.DefineAsRegister(node),                          \
-         g.UseUniqueRegister(node->InputAt(0)), arraysize(temps), temps); \
+#define VISIT_SIMD_ANYTRUE(Opcode)                      \
+  void InstructionSelector::Visit##Opcode(Node* node) { \
+    X64OperandGenerator g(this);                        \
+    Emit(kX64##Opcode, g.DefineAsRegister(node),        \
+         g.UseUniqueRegister(node->InputAt(0)));        \
   }
 SIMD_ANYTRUE_LIST(VISIT_SIMD_ANYTRUE)
 #undef VISIT_SIMD_ANYTRUE
 #undef SIMD_ANYTRUE_LIST
 
-#define VISIT_SIMD_ALLTRUE(Opcode)                                            \
-  void InstructionSelector::Visit##Opcode(Node* node) {                       \
-    X64OperandGenerator g(this);                                              \
-    InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()}; \
-    Emit(kX64##Opcode, g.DefineAsRegister(node),                              \
-         g.UseUniqueRegister(node->InputAt(0)), arraysize(temps), temps);     \
+#define VISIT_SIMD_ALLTRUE(Opcode)                                        \
+  void InstructionSelector::Visit##Opcode(Node* node) {                   \
+    X64OperandGenerator g(this);                                          \
+    InstructionOperand temps[] = {g.TempSimd128Register()};               \
+    Emit(kX64##Opcode, g.DefineAsRegister(node),                          \
+         g.UseUniqueRegister(node->InputAt(0)), arraysize(temps), temps); \
   }
 SIMD_ALLTRUE_LIST(VISIT_SIMD_ALLTRUE)
 #undef VISIT_SIMD_ALLTRUE
@@ -3035,6 +3047,19 @@ void InstructionSelector::VisitI8x16Mul(Node* node) {
        g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps);
 }
 
+void InstructionSelector::VisitI8x16ShrS(Node* node) {
+  X64OperandGenerator g(this);
+  if (g.CanBeImmediate(node->InputAt(1))) {
+    Emit(kX64I8x16ShrS, g.DefineSameAsFirst(node),
+         g.UseRegister(node->InputAt(0)), g.UseImmediate(node->InputAt(1)));
+  } else {
+    InstructionOperand temps[] = {g.TempRegister(), g.TempSimd128Register()};
+    Emit(kX64I8x16ShrS, g.DefineSameAsFirst(node),
+         g.UseUniqueRegister(node->InputAt(0)),
+         g.UseUniqueRegister(node->InputAt(1)), arraysize(temps), temps);
+  }
+}
+
 void InstructionSelector::VisitInt32AbsWithOverflow(Node* node) {
   UNREACHABLE();
 }
diff --git a/deps/v8/src/compiler/branch-elimination.cc b/deps/v8/src/compiler/branch-elimination.cc
index ffc149ea5d..1c8a606726 100644
--- a/deps/v8/src/compiler/branch-elimination.cc
+++ b/deps/v8/src/compiler/branch-elimination.cc
@@ -157,6 +157,11 @@ Reduction BranchElimination::ReduceBranch(Node* node) {
     return Replace(dead());
   }
   SimplifyBranchCondition(node);
+  // Trigger revisits of the IfTrue/IfFalse projections, since they depend on
+  // the branch condition.
+  for (Node* const use : node->uses()) {
+    Revisit(use);
+  }
   return TakeConditionsFromFirstControl(node);
 }
 
diff --git a/deps/v8/src/compiler/bytecode-analysis.cc b/deps/v8/src/compiler/bytecode-analysis.cc
index f1d43fc1a6..cddbabd074 100644
--- a/deps/v8/src/compiler/bytecode-analysis.cc
+++ b/deps/v8/src/compiler/bytecode-analysis.cc
@@ -328,9 +328,7 @@ void BytecodeAnalysis::Analyze() {
     if (bytecode == Bytecode::kSwitchOnGeneratorState) {
       DCHECK_EQ(generator_switch_index, -1);
       generator_switch_index = iterator.current_index();
-    }
-
-    if (bytecode == Bytecode::kJumpLoop) {
+    } else if (bytecode == Bytecode::kJumpLoop) {
       // Every byte up to and including the last byte within the backwards jump
       // instruction is considered part of the loop, set loop end accordingly.
       int loop_end = current_offset + iterator.current_bytecode_size();
@@ -350,7 +348,16 @@ void BytecodeAnalysis::Analyze() {
       if (analyze_liveness_) {
         loop_end_index_queue_.push_back(iterator.current_index());
       }
-    } else if (loop_stack_.size() > 1) {
+    }
+
+    // We have to pop from loop_stack_ if:
+    // 1) We entered the body of the loop
+    // 2) If we have a JumpLoop that jumps to itself (i.e an empty loop)
+    bool pop_current_loop = loop_stack_.size() > 1 &&
+                            (bytecode != Bytecode::kJumpLoop ||
+                             iterator.GetJumpTargetOffset() == current_offset);
+
+    if (pop_current_loop) {
       LoopStackEntry& current_loop = loop_stack_.top();
       LoopInfo* current_loop_info = current_loop.loop_info;
 
@@ -553,10 +560,10 @@ void BytecodeAnalysis::Analyze() {
 }
 
 void BytecodeAnalysis::PushLoop(int loop_header, int loop_end) {
-  DCHECK(loop_header < loop_end);
-  DCHECK(loop_stack_.top().header_offset < loop_header);
-  DCHECK(end_to_header_.find(loop_end) == end_to_header_.end());
-  DCHECK(header_to_info_.find(loop_header) == header_to_info_.end());
+  DCHECK_LT(loop_header, loop_end);
+  DCHECK_LT(loop_stack_.top().header_offset, loop_header);
+  DCHECK_EQ(end_to_header_.find(loop_end), end_to_header_.end());
+  DCHECK_EQ(header_to_info_.find(loop_header), header_to_info_.end());
 
   int parent_offset = loop_stack_.top().header_offset;
 
diff --git a/deps/v8/src/compiler/bytecode-graph-builder.cc b/deps/v8/src/compiler/bytecode-graph-builder.cc
index 064d7ee7e4..b59b5a1b84 100644
--- a/deps/v8/src/compiler/bytecode-graph-builder.cc
+++ b/deps/v8/src/compiler/bytecode-graph-builder.cc
@@ -164,6 +164,8 @@ class BytecodeGraphBuilder {
   // to the given node and the output value produced by the node is combined.
   // Conceptually this frame state is "after" a given operation.
   void PrepareFrameState(Node* node, OutputFrameStateCombine combine);
+  void PrepareFrameState(Node* node, OutputFrameStateCombine combine,
+                         BailoutId bailout_id);
 
   void BuildCreateArguments(CreateArgumentsType type);
   Node* BuildLoadGlobal(NameRef name, uint32_t feedback_slot_index,
@@ -261,6 +263,11 @@ class BytecodeGraphBuilder {
   // feedback. Returns kDisallowSpeculation if feedback is insufficient.
   SpeculationMode GetSpeculationMode(int slot_id) const;
 
+  // Helpers for building the implicit FunctionEntry and IterationBody
+  // StackChecks.
+  void BuildFunctionEntryStackCheck();
+  void BuildIterationBodyStackCheck();
+
   // Control flow plumbing.
   void BuildJump();
   void BuildJumpIf(Node* condition);
@@ -355,8 +362,6 @@ class BytecodeGraphBuilder {
     currently_peeled_loop_offset_ = offset;
   }
   bool skip_first_stack_check() const { return skip_first_stack_check_; }
-  bool visited_first_stack_check() const { return visited_first_stack_check_; }
-  void set_visited_first_stack_check() { visited_first_stack_check_ = true; }
   int current_exception_handler() const { return current_exception_handler_; }
   void set_current_exception_handler(int index) {
     current_exception_handler_ = index;
@@ -395,7 +400,6 @@ class BytecodeGraphBuilder {
   int currently_peeled_loop_offset_;
 
   const bool skip_first_stack_check_;
-  bool visited_first_stack_check_ = false;
 
   // Merge environments are snapshots of the environment at points where the
   // control flow merges. This models a forward data flow propagation of all
@@ -1086,16 +1090,30 @@ void BytecodeGraphBuilder::PrepareEagerCheckpoint() {
 void BytecodeGraphBuilder::PrepareFrameState(Node* node,
                                              OutputFrameStateCombine combine) {
   if (OperatorProperties::HasFrameStateInput(node->op())) {
+    PrepareFrameState(node, combine,
+                      BailoutId(bytecode_iterator().current_offset()));
+  }
+}
+
+void BytecodeGraphBuilder::PrepareFrameState(Node* node,
+                                             OutputFrameStateCombine combine,
+                                             BailoutId bailout_id) {
+  if (OperatorProperties::HasFrameStateInput(node->op())) {
     // Add the frame state for after the operation. The node in question has
     // already been created and had a {Dead} frame state input up until now.
     DCHECK_EQ(1, OperatorProperties::GetFrameStateInputCount(node->op()));
     DCHECK_EQ(IrOpcode::kDead,
               NodeProperties::GetFrameStateInput(node)->opcode());
-    BailoutId bailout_id(bytecode_iterator().current_offset());
+    DCHECK_IMPLIES(bailout_id.ToInt() == kFunctionEntryBytecodeOffset,
+                   bytecode_iterator().current_offset() == 0);
 
+    // If we have kFunctionEntryBytecodeOffset as the bailout_id, we want to get
+    // the liveness at the moment of function entry. This is the same as the IN
+    // liveness of the first actual bytecode.
     const BytecodeLivenessState* liveness_after =
-        bytecode_analysis().GetOutLivenessFor(
-            bytecode_iterator().current_offset());
+        bailout_id.ToInt() == kFunctionEntryBytecodeOffset
+            ? bytecode_analysis().GetInLivenessFor(0)
+            : bytecode_analysis().GetOutLivenessFor(bailout_id.ToInt());
 
     Node* frame_state_after =
         environment()->Checkpoint(bailout_id, combine, liveness_after);
@@ -1204,6 +1222,21 @@ void BytecodeGraphBuilder::RemoveMergeEnvironmentsBeforeOffset(
   }
 }
 
+void BytecodeGraphBuilder::BuildFunctionEntryStackCheck() {
+  if (!skip_first_stack_check()) {
+    Node* node =
+        NewNode(javascript()->StackCheck(StackCheckKind::kJSFunctionEntry));
+    PrepareFrameState(node, OutputFrameStateCombine::Ignore(),
+                      BailoutId(kFunctionEntryBytecodeOffset));
+  }
+}
+
+void BytecodeGraphBuilder::BuildIterationBodyStackCheck() {
+  Node* node =
+      NewNode(javascript()->StackCheck(StackCheckKind::kJSIterationBody));
+  environment()->RecordAfterState(node, Environment::kAttachFrameState);
+}
+
 // We will iterate through the OSR loop, then its parent, and so on
 // until we have reached the outmost loop containing the OSR loop. We do
 // not generate nodes for anything before the outermost loop.
@@ -1307,6 +1340,8 @@ void BytecodeGraphBuilder::VisitBytecodes() {
     // the last copies of the loops it contains) to be generated by the normal
     // bytecode iteration below.
     AdvanceToOsrEntryAndPeelLoops();
+  } else {
+    BuildFunctionEntryStackCheck();
   }
 
   bool has_one_shot_bytecode = false;
@@ -3229,7 +3264,10 @@ void BytecodeGraphBuilder::VisitJumpIfUndefinedOrNullConstant() {
   BuildJumpIfEqual(jsgraph()->NullConstant());
 }
 
-void BytecodeGraphBuilder::VisitJumpLoop() { BuildJump(); }
+void BytecodeGraphBuilder::VisitJumpLoop() {
+  BuildIterationBodyStackCheck();
+  BuildJump();
+}
 
 void BytecodeGraphBuilder::BuildSwitchOnSmi(Node* condition) {
   interpreter::JumpTableTargetOffsets offsets =
@@ -3252,24 +3290,6 @@ void BytecodeGraphBuilder::VisitSwitchOnSmiNoFeedback() {
   BuildSwitchOnSmi(acc_smi);
 }
 
-void BytecodeGraphBuilder::VisitStackCheck() {
-  // Note: The stack check kind is determined heuristically: we simply assume
-  // that the first seen stack check is at function-entry, and all other stack
-  // checks are at iteration-body. An alternative precise solution would be to
-  // parameterize the StackCheck bytecode; but this has the caveat of increased
-  // code size.
-  StackCheckKind kind = StackCheckKind::kJSIterationBody;
-  if (!visited_first_stack_check()) {
-    set_visited_first_stack_check();
-    kind = StackCheckKind::kJSFunctionEntry;
-    if (skip_first_stack_check()) return;
-  }
-
-  PrepareEagerCheckpoint();
-  Node* node = NewNode(javascript()->StackCheck(kind));
-  environment()->RecordAfterState(node, Environment::kAttachFrameState);
-}
-
 void BytecodeGraphBuilder::VisitSetPendingMessage() {
   Node* previous_message = NewNode(javascript()->LoadMessage());
   NewNode(javascript()->StoreMessage(), environment()->LookupAccumulator());
diff --git a/deps/v8/src/compiler/c-linkage.cc b/deps/v8/src/compiler/c-linkage.cc
index 4c576b771a..4967f2bbfa 100644
--- a/deps/v8/src/compiler/c-linkage.cc
+++ b/deps/v8/src/compiler/c-linkage.cc
@@ -68,8 +68,7 @@ namespace {
   (1 << x19.code()) | (1 << x20.code()) | (1 << x21.code()) |     \
       (1 << x22.code()) | (1 << x23.code()) | (1 << x24.code()) | \
       (1 << x25.code()) | (1 << x26.code()) | (1 << x27.code()) | \
-      (1 << x28.code()) | (1 << x29.code()) | (1 << x30.code())
-
+      (1 << x28.code())
 
 #define CALLEE_SAVE_FP_REGISTERS                                  \
   (1 << d8.code()) | (1 << d9.code()) | (1 << d10.code()) |       \
diff --git a/deps/v8/src/compiler/code-assembler.cc b/deps/v8/src/compiler/code-assembler.cc
index 2eee2aed15..302c429f0f 100644
--- a/deps/v8/src/compiler/code-assembler.cc
+++ b/deps/v8/src/compiler/code-assembler.cc
@@ -257,6 +257,11 @@ TNode<IntPtrT> CodeAssembler::IntPtrConstant(intptr_t value) {
   return UncheckedCast<IntPtrT>(jsgraph()->IntPtrConstant(value));
 }
 
+TNode<TaggedIndex> CodeAssembler::TaggedIndexConstant(intptr_t value) {
+  DCHECK(TaggedIndex::IsValid(value));
+  return UncheckedCast<TaggedIndex>(raw_assembler()->IntPtrConstant(value));
+}
+
 TNode<Number> CodeAssembler::NumberConstant(double value) {
   int smi_value;
   if (DoubleToSmiInteger(value, &smi_value)) {
@@ -446,7 +451,7 @@ void CodeAssembler::PopAndReturn(Node* pop, Node* value) {
   return raw_assembler()->PopAndReturn(pop, value);
 }
 
-void CodeAssembler::ReturnIf(Node* condition, TNode<Object> value) {
+void CodeAssembler::ReturnIf(TNode<BoolT> condition, TNode<Object> value) {
   Label if_return(this), if_continue(this);
   Branch(condition, &if_return, &if_continue);
   Bind(&if_return);
@@ -494,13 +499,12 @@ TNode<RawPtrT> CodeAssembler::LoadParentFramePointer() {
   return UncheckedCast<RawPtrT>(raw_assembler()->LoadParentFramePointer());
 }
 
-TNode<Object> CodeAssembler::TaggedPoisonOnSpeculation(
-    SloppyTNode<Object> value) {
+TNode<Object> CodeAssembler::TaggedPoisonOnSpeculation(TNode<Object> value) {
   return UncheckedCast<Object>(
       raw_assembler()->TaggedPoisonOnSpeculation(value));
 }
 
-TNode<WordT> CodeAssembler::WordPoisonOnSpeculation(SloppyTNode<WordT> value) {
+TNode<WordT> CodeAssembler::WordPoisonOnSpeculation(TNode<WordT> value) {
   return UncheckedCast<WordT>(raw_assembler()->WordPoisonOnSpeculation(value));
 }
 
@@ -550,7 +554,7 @@ CODE_ASSEMBLER_COMPARE(Word64Equal, Word64T, int64_t, ToInt64Constant, ==)
 CODE_ASSEMBLER_COMPARE(Word64NotEqual, Word64T, int64_t, ToInt64Constant, !=)
 #undef CODE_ASSEMBLER_COMPARE
 
-TNode<UintPtrT> CodeAssembler::ChangeUint32ToWord(SloppyTNode<Word32T> value) {
+TNode<UintPtrT> CodeAssembler::ChangeUint32ToWord(TNode<Word32T> value) {
   if (raw_assembler()->machine()->Is64()) {
     return UncheckedCast<UintPtrT>(
         raw_assembler()->ChangeUint32ToUint64(value));
@@ -558,47 +562,43 @@ TNode<UintPtrT> CodeAssembler::ChangeUint32ToWord(SloppyTNode<Word32T> value) {
   return ReinterpretCast<UintPtrT>(value);
 }
 
-TNode<IntPtrT> CodeAssembler::ChangeInt32ToIntPtr(SloppyTNode<Word32T> value) {
+TNode<IntPtrT> CodeAssembler::ChangeInt32ToIntPtr(TNode<Word32T> value) {
   if (raw_assembler()->machine()->Is64()) {
-    return ReinterpretCast<IntPtrT>(raw_assembler()->ChangeInt32ToInt64(value));
+    return UncheckedCast<IntPtrT>(raw_assembler()->ChangeInt32ToInt64(value));
   }
   return ReinterpretCast<IntPtrT>(value);
 }
 
 TNode<IntPtrT> CodeAssembler::ChangeFloat64ToIntPtr(TNode<Float64T> value) {
   if (raw_assembler()->machine()->Is64()) {
-    return ReinterpretCast<IntPtrT>(
-        raw_assembler()->ChangeFloat64ToInt64(value));
+    return UncheckedCast<IntPtrT>(raw_assembler()->ChangeFloat64ToInt64(value));
   }
-  return ReinterpretCast<IntPtrT>(raw_assembler()->ChangeFloat64ToInt32(value));
+  return UncheckedCast<IntPtrT>(raw_assembler()->ChangeFloat64ToInt32(value));
 }
 
-TNode<UintPtrT> CodeAssembler::ChangeFloat64ToUintPtr(
-    SloppyTNode<Float64T> value) {
+TNode<UintPtrT> CodeAssembler::ChangeFloat64ToUintPtr(TNode<Float64T> value) {
   if (raw_assembler()->machine()->Is64()) {
-    return ReinterpretCast<UintPtrT>(
+    return UncheckedCast<UintPtrT>(
         raw_assembler()->ChangeFloat64ToUint64(value));
   }
-  return ReinterpretCast<UintPtrT>(
-      raw_assembler()->ChangeFloat64ToUint32(value));
+  return UncheckedCast<UintPtrT>(raw_assembler()->ChangeFloat64ToUint32(value));
 }
 
 TNode<Float64T> CodeAssembler::ChangeUintPtrToFloat64(TNode<UintPtrT> value) {
   if (raw_assembler()->machine()->Is64()) {
     // TODO(turbofan): Maybe we should introduce a ChangeUint64ToFloat64
     // machine operator to TurboFan here?
-    return ReinterpretCast<Float64T>(
+    return UncheckedCast<Float64T>(
         raw_assembler()->RoundUint64ToFloat64(value));
   }
-  return ReinterpretCast<Float64T>(
-      raw_assembler()->ChangeUint32ToFloat64(value));
+  return UncheckedCast<Float64T>(raw_assembler()->ChangeUint32ToFloat64(value));
 }
 
-Node* CodeAssembler::RoundIntPtrToFloat64(Node* value) {
+TNode<Float64T> CodeAssembler::RoundIntPtrToFloat64(Node* value) {
   if (raw_assembler()->machine()->Is64()) {
-    return raw_assembler()->RoundInt64ToFloat64(value);
+    return UncheckedCast<Float64T>(raw_assembler()->RoundInt64ToFloat64(value));
   }
-  return raw_assembler()->ChangeInt32ToFloat64(value);
+  return UncheckedCast<Float64T>(raw_assembler()->ChangeInt32ToFloat64(value));
 }
 
 #define DEFINE_CODE_ASSEMBLER_UNARY_OP(name, ResType, ArgType) \
@@ -808,35 +808,6 @@ Node* CodeAssembler::Projection(int index, Node* value) {
   return raw_assembler()->Projection(index, value);
 }
 
-void CodeAssembler::GotoIfException(Node* node, Label* if_exception,
-                                    Variable* exception_var) {
-  if (if_exception == nullptr) {
-    // If no handler is supplied, don't add continuations
-    return;
-  }
-
-  // No catch handlers should be active if we're using catch labels
-  DCHECK_EQ(state()->exception_handler_labels_.size(), 0);
-  DCHECK(!node->op()->HasProperty(Operator::kNoThrow));
-
-  Label success(this), exception(this, Label::kDeferred);
-  success.MergeVariables();
-  exception.MergeVariables();
-
-  raw_assembler()->Continuations(node, success.label_, exception.label_);
-
-  Bind(&exception);
-  const Operator* op = raw_assembler()->common()->IfException();
-  Node* exception_value = raw_assembler()->AddNode(op, node, node);
-  if (exception_var != nullptr) {
-    exception_var->Bind(exception_value);
-  }
-  Goto(if_exception);
-
-  Bind(&success);
-  raw_assembler()->AddNode(raw_assembler()->common()->IfSuccess(), node);
-}
-
 TNode<HeapObject> CodeAssembler::OptimizedAllocate(
     TNode<IntPtrT> size, AllocationType allocation,
     AllowLargeObjects allow_large_objects) {
@@ -1023,6 +994,33 @@ Node* CodeAssembler::CallStubRImpl(StubCallMode call_mode,
                    inputs.data());
 }
 
+Node* CodeAssembler::CallJSStubImpl(const CallInterfaceDescriptor& descriptor,
+                                    TNode<Object> target, TNode<Object> context,
+                                    TNode<Object> function,
+                                    TNode<Object> new_target,
+                                    TNode<Int32T> arity,
+                                    std::initializer_list<Node*> args) {
+  constexpr size_t kMaxNumArgs = 10;
+  DCHECK_GE(kMaxNumArgs, args.size());
+  NodeArray<kMaxNumArgs + 5> inputs;
+  inputs.Add(target);
+  inputs.Add(function);
+  if (!new_target.is_null()) {
+    inputs.Add(new_target);
+  }
+  inputs.Add(arity);
+#ifdef V8_REVERSE_JSARGS
+  for (auto arg : base::Reversed(args)) inputs.Add(arg);
+#else
+  for (auto arg : args) inputs.Add(arg);
+#endif
+  if (descriptor.HasContextParameter()) {
+    inputs.Add(context);
+  }
+  return CallStubN(StubCallMode::kCallCodeObject, descriptor, 1, inputs.size(),
+                   inputs.data());
+}
+
 void CodeAssembler::TailCallStubThenBytecodeDispatchImpl(
     const CallInterfaceDescriptor& descriptor, Node* target, Node* context,
     std::initializer_list<Node*> args) {
@@ -1112,21 +1110,19 @@ void CodeAssembler::Goto(Label* label) {
   raw_assembler()->Goto(label->label_);
 }
 
-void CodeAssembler::GotoIf(SloppyTNode<IntegralT> condition,
-                           Label* true_label) {
+void CodeAssembler::GotoIf(TNode<IntegralT> condition, Label* true_label) {
   Label false_label(this);
   Branch(condition, true_label, &false_label);
   Bind(&false_label);
 }
 
-void CodeAssembler::GotoIfNot(SloppyTNode<IntegralT> condition,
-                              Label* false_label) {
+void CodeAssembler::GotoIfNot(TNode<IntegralT> condition, Label* false_label) {
   Label true_label(this);
   Branch(condition, &true_label, false_label);
   Bind(&true_label);
 }
 
-void CodeAssembler::Branch(SloppyTNode<IntegralT> condition, Label* true_label,
+void CodeAssembler::Branch(TNode<IntegralT> condition, Label* true_label,
                            Label* false_label) {
   int32_t constant;
   if (ToInt32Constant(condition, &constant)) {
@@ -1557,7 +1553,7 @@ void CodeAssemblerState::PopExceptionHandler() {
   exception_handler_labels_.pop_back();
 }
 
-CodeAssemblerScopedExceptionHandler::CodeAssemblerScopedExceptionHandler(
+ScopedExceptionHandler::ScopedExceptionHandler(
     CodeAssembler* assembler, CodeAssemblerExceptionHandlerLabel* label)
     : has_handler_(label != nullptr),
       assembler_(assembler),
@@ -1568,7 +1564,7 @@ CodeAssemblerScopedExceptionHandler::CodeAssemblerScopedExceptionHandler(
   }
 }
 
-CodeAssemblerScopedExceptionHandler::CodeAssemblerScopedExceptionHandler(
+ScopedExceptionHandler::ScopedExceptionHandler(
     CodeAssembler* assembler, CodeAssemblerLabel* label,
     TypedCodeAssemblerVariable<Object>* exception)
     : has_handler_(label != nullptr),
@@ -1582,7 +1578,7 @@ CodeAssemblerScopedExceptionHandler::CodeAssemblerScopedExceptionHandler(
   }
 }
 
-CodeAssemblerScopedExceptionHandler::~CodeAssemblerScopedExceptionHandler() {
+ScopedExceptionHandler::~ScopedExceptionHandler() {
   if (has_handler_) {
     assembler_->state()->PopExceptionHandler();
   }
@@ -1594,7 +1590,7 @@ CodeAssemblerScopedExceptionHandler::~CodeAssemblerScopedExceptionHandler() {
     }
     TNode<Object> e;
     assembler_->Bind(label_.get(), &e);
-    *exception_ = e;
+    if (exception_ != nullptr) *exception_ = e;
     assembler_->Goto(compatibility_label_);
     if (inside_block) {
       assembler_->Bind(&skip);
@@ -1625,6 +1621,7 @@ Address CheckObjectType(Address raw_value, Address raw_type,
 
     TYPE_CASE(Object)
     TYPE_CASE(Smi)
+    TYPE_CASE(TaggedIndex)
     TYPE_CASE(HeapObject)
     OBJECT_TYPE_LIST(TYPE_CASE)
     HEAP_OBJECT_TYPE_LIST(TYPE_CASE)
diff --git a/deps/v8/src/compiler/code-assembler.h b/deps/v8/src/compiler/code-assembler.h
index af49852015..3a137fdee2 100644
--- a/deps/v8/src/compiler/code-assembler.h
+++ b/deps/v8/src/compiler/code-assembler.h
@@ -29,6 +29,8 @@
 #include "src/objects/maybe-object.h"
 #include "src/objects/objects.h"
 #include "src/objects/oddball.h"
+#include "src/objects/smi.h"
+#include "src/objects/tagged-index.h"
 #include "src/runtime/runtime.h"
 #include "src/utils/allocation.h"
 #include "src/zone/zone-containers.h"
@@ -62,8 +64,8 @@ class JSSegmentIterator;
 class JSSegmenter;
 class JSV8BreakIterator;
 class JSWeakCollection;
-class JSFinalizationGroup;
-class JSFinalizationGroupCleanupIterator;
+class JSFinalizationRegistry;
+class JSFinalizationRegistryCleanupIterator;
 class JSWeakMap;
 class JSWeakRef;
 class JSWeakSet;
@@ -75,7 +77,7 @@ class PromiseRejectReactionJobTask;
 class WasmDebugInfo;
 class Zone;
 #define MAKE_FORWARD_DECLARATION(V, NAME, Name, name) class Name;
-TORQUE_STRUCT_LIST_GENERATOR(MAKE_FORWARD_DECLARATION, UNUSED)
+TORQUE_INTERNAL_CLASS_LIST_GENERATOR(MAKE_FORWARD_DECLARATION, UNUSED)
 #undef MAKE_FORWARD_DECLARATION
 
 template <typename T>
@@ -86,6 +88,7 @@ class Signature;
 enum class ObjectType {
   ENUM_ELEMENT(Object)                 //
   ENUM_ELEMENT(Smi)                    //
+  ENUM_ELEMENT(TaggedIndex)            //
   ENUM_ELEMENT(HeapObject)             //
   OBJECT_TYPE_LIST(ENUM_ELEMENT)       //
   HEAP_OBJECT_TYPE_LIST(ENUM_ELEMENT)  //
@@ -163,6 +166,7 @@ struct ObjectTypeOf {};
   };
 OBJECT_TYPE_CASE(Object)
 OBJECT_TYPE_CASE(Smi)
+OBJECT_TYPE_CASE(TaggedIndex)
 OBJECT_TYPE_CASE(HeapObject)
 OBJECT_TYPE_LIST(OBJECT_TYPE_CASE)
 HEAP_OBJECT_ORDINARY_TYPE_LIST(OBJECT_TYPE_CASE)
@@ -508,6 +512,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   TNode<UintPtrT> UintPtrConstant(uintptr_t value) {
     return Unsigned(IntPtrConstant(bit_cast<intptr_t>(value)));
   }
+  TNode<TaggedIndex> TaggedIndexConstant(intptr_t value);
   TNode<RawPtrT> PointerConstant(void* value) {
     return ReinterpretCast<RawPtrT>(IntPtrConstant(bit_cast<intptr_t>(value)));
   }
@@ -570,7 +575,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   void Return(TNode<WordT> value1, TNode<WordT> value2);
   void PopAndReturn(Node* pop, Node* value);
 
-  void ReturnIf(Node* condition, TNode<Object> value);
+  void ReturnIf(TNode<BoolT> condition, TNode<Object> value);
 
   void AbortCSAAssert(Node* message);
   void DebugBreak();
@@ -597,9 +602,9 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   void Bind(Label* label, AssemblerDebugInfo debug_info);
 #endif  // DEBUG
   void Goto(Label* label);
-  void GotoIf(SloppyTNode<IntegralT> condition, Label* true_label);
-  void GotoIfNot(SloppyTNode<IntegralT> condition, Label* false_label);
-  void Branch(SloppyTNode<IntegralT> condition, Label* true_label,
+  void GotoIf(TNode<IntegralT> condition, Label* true_label);
+  void GotoIfNot(TNode<IntegralT> condition, Label* false_label);
+  void Branch(TNode<IntegralT> condition, Label* true_label,
               Label* false_label);
 
   template <class T>
@@ -620,6 +625,16 @@ class V8_EXPORT_PRIVATE CodeAssembler {
     if_false->AddInputs(args...);
     Branch(condition, if_true->plain_label(), if_false->plain_label());
   }
+  template <class... T, class... U>
+  void Branch(TNode<BoolT> condition,
+              CodeAssemblerParameterizedLabel<T...>* if_true,
+              std::vector<Node*> args_true,
+              CodeAssemblerParameterizedLabel<U...>* if_false,
+              std::vector<Node*> args_false) {
+    if_true->AddInputsVector(std::move(args_true));
+    if_false->AddInputsVector(std::move(args_false));
+    Branch(condition, if_true->plain_label(), if_false->plain_label());
+  }
 
   template <class... T, class... Args>
   void Goto(CodeAssemblerParameterizedLabel<T...>* label, Args... args) {
@@ -642,8 +657,8 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   TNode<RawPtrT> LoadParentFramePointer();
 
   // Poison |value| on speculative paths.
-  TNode<Object> TaggedPoisonOnSpeculation(SloppyTNode<Object> value);
-  TNode<WordT> WordPoisonOnSpeculation(SloppyTNode<WordT> value);
+  TNode<Object> TaggedPoisonOnSpeculation(TNode<Object> value);
+  TNode<WordT> WordPoisonOnSpeculation(TNode<WordT> value);
 
   // Load raw memory location.
   Node* Load(MachineType type, Node* base,
@@ -905,18 +920,18 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   // Changes a double to an inptr_t for pointer arithmetic outside of Smi range.
   // Assumes that the double can be exactly represented as an int.
   TNode<IntPtrT> ChangeFloat64ToIntPtr(TNode<Float64T> value);
-  TNode<UintPtrT> ChangeFloat64ToUintPtr(SloppyTNode<Float64T> value);
+  TNode<UintPtrT> ChangeFloat64ToUintPtr(TNode<Float64T> value);
   // Same in the opposite direction.
   TNode<Float64T> ChangeUintPtrToFloat64(TNode<UintPtrT> value);
 
   // Changes an intptr_t to a double, e.g. for storing an element index
   // outside Smi range in a HeapNumber. Lossless on 32-bit,
   // rounds on 64-bit (which doesn't affect valid element indices).
-  Node* RoundIntPtrToFloat64(Node* value);
+  TNode<Float64T> RoundIntPtrToFloat64(Node* value);
   // No-op on 32-bit, otherwise zero extend.
-  TNode<UintPtrT> ChangeUint32ToWord(SloppyTNode<Word32T> value);
+  TNode<UintPtrT> ChangeUint32ToWord(TNode<Word32T> value);
   // No-op on 32-bit, otherwise sign extend.
-  TNode<IntPtrT> ChangeInt32ToIntPtr(SloppyTNode<Word32T> value);
+  TNode<IntPtrT> ChangeInt32ToIntPtr(TNode<Word32T> value);
 
   // No-op that guarantees that the value is kept alive till this point even
   // if GC happens.
@@ -935,26 +950,26 @@ class V8_EXPORT_PRIVATE CodeAssembler {
 
   // Calls
   template <class... TArgs>
-  TNode<Object> CallRuntime(Runtime::FunctionId function,
-                            SloppyTNode<Object> context, TArgs... args) {
+  TNode<Object> CallRuntime(Runtime::FunctionId function, TNode<Object> context,
+                            TArgs... args) {
     return CallRuntimeImpl(function, context,
-                           {implicit_cast<SloppyTNode<Object>>(args)...});
+                           {implicit_cast<TNode<Object>>(args)...});
   }
 
   template <class... TArgs>
-  void TailCallRuntime(Runtime::FunctionId function,
-                       SloppyTNode<Object> context, TArgs... args) {
+  void TailCallRuntime(Runtime::FunctionId function, TNode<Object> context,
+                       TArgs... args) {
     int argc = static_cast<int>(sizeof...(args));
     TNode<Int32T> arity = Int32Constant(argc);
     return TailCallRuntimeImpl(function, arity, context,
-                               {implicit_cast<SloppyTNode<Object>>(args)...});
+                               {implicit_cast<TNode<Object>>(args)...});
   }
 
   template <class... TArgs>
   void TailCallRuntime(Runtime::FunctionId function, TNode<Int32T> arity,
-                       SloppyTNode<Object> context, TArgs... args) {
+                       TNode<Object> context, TArgs... args) {
     return TailCallRuntimeImpl(function, arity, context,
-                               {implicit_cast<SloppyTNode<Object>>(args)...});
+                               {implicit_cast<TNode<Object>>(args)...});
   }
 
   //
@@ -962,7 +977,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   //
 
   template <class T = Object, class... TArgs>
-  TNode<T> CallStub(Callable const& callable, SloppyTNode<Object> context,
+  TNode<T> CallStub(Callable const& callable, TNode<Object> context,
                     TArgs... args) {
     TNode<Code> target = HeapConstant(callable.code());
     return CallStub<T>(callable.descriptor(), target, context, args...);
@@ -970,8 +985,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
 
   template <class T = Object, class... TArgs>
   TNode<T> CallStub(const CallInterfaceDescriptor& descriptor,
-                    SloppyTNode<Code> target, SloppyTNode<Object> context,
-                    TArgs... args) {
+                    TNode<Code> target, TNode<Object> context, TArgs... args) {
     return UncheckedCast<T>(CallStubR(StubCallMode::kCallCodeObject, descriptor,
                                       1, target, context, args...));
   }
@@ -979,8 +993,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   template <class... TArgs>
   Node* CallStubR(StubCallMode call_mode,
                   const CallInterfaceDescriptor& descriptor, size_t result_size,
-                  SloppyTNode<Object> target, SloppyTNode<Object> context,
-                  TArgs... args) {
+                  TNode<Object> target, TNode<Object> context, TArgs... args) {
     return CallStubRImpl(call_mode, descriptor, result_size, target, context,
                          {args...});
   }
@@ -998,7 +1011,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   }
 
   template <class... TArgs>
-  void TailCallStub(Callable const& callable, SloppyTNode<Object> context,
+  void TailCallStub(Callable const& callable, TNode<Object> context,
                     TArgs... args) {
     TNode<Code> target = HeapConstant(callable.code());
     TailCallStub(callable.descriptor(), target, context, args...);
@@ -1006,8 +1019,7 @@ class V8_EXPORT_PRIVATE CodeAssembler {
 
   template <class... TArgs>
   void TailCallStub(const CallInterfaceDescriptor& descriptor,
-                    SloppyTNode<Code> target, SloppyTNode<Object> context,
-                    TArgs... args) {
+                    TNode<Code> target, TNode<Object> context, TArgs... args) {
     TailCallStubImpl(descriptor, target, context, {args...});
   }
 
@@ -1039,19 +1051,22 @@ class V8_EXPORT_PRIVATE CodeAssembler {
                        Node* receiver, TArgs... args) {
     int argc = static_cast<int>(sizeof...(args));
     TNode<Int32T> arity = Int32Constant(argc);
-    return CallStub(callable, context, function, arity, receiver, args...);
+    TNode<Code> target = HeapConstant(callable.code());
+    return CAST(CallJSStubImpl(callable.descriptor(), target, CAST(context),
+                               CAST(function), TNode<Object>(), arity,
+                               {receiver, args...}));
   }
 
   template <class... TArgs>
   Node* ConstructJSWithTarget(Callable const& callable, Node* context,
-                              Node* target, Node* new_target, TArgs... args) {
+                              Node* function, Node* new_target, TArgs... args) {
     int argc = static_cast<int>(sizeof...(args));
     TNode<Int32T> arity = Int32Constant(argc);
     TNode<Object> receiver = LoadRoot(RootIndex::kUndefinedValue);
-
-    // Construct(target, new_target, arity, receiver, arguments...)
-    return CallStub(callable, context, target, new_target, arity, receiver,
-                    args...);
+    TNode<Code> target = HeapConstant(callable.code());
+    return CallJSStubImpl(callable.descriptor(), target, CAST(context),
+                          CAST(function), CAST(new_target), arity,
+                          {receiver, args...});
   }
   template <class... TArgs>
   Node* ConstructJS(Callable const& callable, Node* context, Node* new_target,
@@ -1100,10 +1115,6 @@ class V8_EXPORT_PRIVATE CodeAssembler {
                                                  {cargs...});
   }
 
-  // Exception handling support.
-  void GotoIfException(Node* node, Label* if_exception,
-                       Variable* exception_var = nullptr);
-
   // Helpers which delegate to RawMachineAssembler.
   Factory* factory() const;
   Isolate* isolate() const;
@@ -1164,6 +1175,11 @@ class V8_EXPORT_PRIVATE CodeAssembler {
                       size_t result_size, TNode<Object> target,
                       TNode<Object> context, std::initializer_list<Node*> args);
 
+  Node* CallJSStubImpl(const CallInterfaceDescriptor& descriptor,
+                       TNode<Object> target, TNode<Object> context,
+                       TNode<Object> function, TNode<Object> new_target,
+                       TNode<Int32T> arity, std::initializer_list<Node*> args);
+
   // These two don't have definitions and are here only for catching use cases
   // where the cast is not necessary.
   TNode<Int32T> Signed(TNode<Int32T> x);
@@ -1349,6 +1365,9 @@ class CodeAssemblerParameterizedLabel
  private:
   friend class CodeAssembler;
 
+  void AddInputsVector(std::vector<Node*> inputs) {
+    CodeAssemblerParameterizedLabelBase::AddInputs(std::move(inputs));
+  }
   void AddInputs(TNode<Types>... inputs) {
     CodeAssemblerParameterizedLabelBase::AddInputs(
         std::vector<Node*>{inputs...});
@@ -1403,7 +1422,7 @@ class V8_EXPORT_PRIVATE CodeAssemblerState {
   friend class CodeAssemblerVariable;
   friend class CodeAssemblerTester;
   friend class CodeAssemblerParameterizedLabelBase;
-  friend class CodeAssemblerScopedExceptionHandler;
+  friend class ScopedExceptionHandler;
 
   CodeAssemblerState(Isolate* isolate, Zone* zone,
                      CallDescriptor* call_descriptor, Code::Kind kind,
@@ -1432,18 +1451,17 @@ class V8_EXPORT_PRIVATE CodeAssemblerState {
   DISALLOW_COPY_AND_ASSIGN(CodeAssemblerState);
 };
 
-class V8_EXPORT_PRIVATE CodeAssemblerScopedExceptionHandler {
+class V8_EXPORT_PRIVATE ScopedExceptionHandler {
  public:
-  CodeAssemblerScopedExceptionHandler(
-      CodeAssembler* assembler, CodeAssemblerExceptionHandlerLabel* label);
+  ScopedExceptionHandler(CodeAssembler* assembler,
+                         CodeAssemblerExceptionHandlerLabel* label);
 
   // Use this constructor for compatability/ports of old CSA code only. New code
   // should use the CodeAssemblerExceptionHandlerLabel version.
-  CodeAssemblerScopedExceptionHandler(
-      CodeAssembler* assembler, CodeAssemblerLabel* label,
-      TypedCodeAssemblerVariable<Object>* exception);
+  ScopedExceptionHandler(CodeAssembler* assembler, CodeAssemblerLabel* label,
+                         TypedCodeAssemblerVariable<Object>* exception);
 
-  ~CodeAssemblerScopedExceptionHandler();
+  ~ScopedExceptionHandler();
 
  private:
   bool has_handler_;
diff --git a/deps/v8/src/compiler/common-node-cache.cc b/deps/v8/src/compiler/common-node-cache.cc
index 92c9c78c71..97d2774016 100644
--- a/deps/v8/src/compiler/common-node-cache.cc
+++ b/deps/v8/src/compiler/common-node-cache.cc
@@ -12,21 +12,23 @@ namespace internal {
 namespace compiler {
 
 Node** CommonNodeCache::FindExternalConstant(ExternalReference value) {
-  return external_constants_.Find(zone(), bit_cast<intptr_t>(value.address()));
+  return external_constants_.Find(bit_cast<intptr_t>(value.address()));
 }
 
 
 Node** CommonNodeCache::FindHeapConstant(Handle<HeapObject> value) {
-  return heap_constants_.Find(zone(), bit_cast<intptr_t>(value.address()));
+  return heap_constants_.Find(bit_cast<intptr_t>(value.address()));
 }
 
 
 void CommonNodeCache::GetCachedNodes(ZoneVector<Node*>* nodes) {
   int32_constants_.GetCachedNodes(nodes);
   int64_constants_.GetCachedNodes(nodes);
+  tagged_index_constants_.GetCachedNodes(nodes);
   float32_constants_.GetCachedNodes(nodes);
   float64_constants_.GetCachedNodes(nodes);
   external_constants_.GetCachedNodes(nodes);
+  pointer_constants_.GetCachedNodes(nodes);
   number_constants_.GetCachedNodes(nodes);
   heap_constants_.GetCachedNodes(nodes);
   relocatable_int32_constants_.GetCachedNodes(nodes);
diff --git a/deps/v8/src/compiler/common-node-cache.h b/deps/v8/src/compiler/common-node-cache.h
index 6a36c979a1..b1a8370a7f 100644
--- a/deps/v8/src/compiler/common-node-cache.h
+++ b/deps/v8/src/compiler/common-node-cache.h
@@ -22,58 +22,70 @@ namespace compiler {
 // Bundles various caches for common nodes.
 class CommonNodeCache final {
  public:
-  explicit CommonNodeCache(Zone* zone) : zone_(zone) {}
+  explicit CommonNodeCache(Zone* zone)
+      : int32_constants_(zone),
+        int64_constants_(zone),
+        tagged_index_constants_(zone),
+        float32_constants_(zone),
+        float64_constants_(zone),
+        external_constants_(zone),
+        pointer_constants_(zone),
+        number_constants_(zone),
+        heap_constants_(zone),
+        relocatable_int32_constants_(zone),
+        relocatable_int64_constants_(zone) {}
   ~CommonNodeCache() = default;
 
   Node** FindInt32Constant(int32_t value) {
-    return int32_constants_.Find(zone(), value);
+    return int32_constants_.Find(value);
   }
 
   Node** FindInt64Constant(int64_t value) {
-    return int64_constants_.Find(zone(), value);
+    return int64_constants_.Find(value);
+  }
+
+  Node** FindTaggedIndexConstant(int32_t value) {
+    return tagged_index_constants_.Find(value);
   }
 
   Node** FindFloat32Constant(float value) {
     // We canonicalize float constants at the bit representation level.
-    return float32_constants_.Find(zone(), bit_cast<int32_t>(value));
+    return float32_constants_.Find(bit_cast<int32_t>(value));
   }
 
   Node** FindFloat64Constant(double value) {
     // We canonicalize double constants at the bit representation level.
-    return float64_constants_.Find(zone(), bit_cast<int64_t>(value));
+    return float64_constants_.Find(bit_cast<int64_t>(value));
   }
 
   Node** FindExternalConstant(ExternalReference value);
 
   Node** FindPointerConstant(intptr_t value) {
-    return pointer_constants_.Find(zone(), value);
+    return pointer_constants_.Find(value);
   }
 
   Node** FindNumberConstant(double value) {
     // We canonicalize double constants at the bit representation level.
-    return number_constants_.Find(zone(), bit_cast<int64_t>(value));
+    return number_constants_.Find(bit_cast<int64_t>(value));
   }
 
   Node** FindHeapConstant(Handle<HeapObject> value);
 
   Node** FindRelocatableInt32Constant(int32_t value, RelocInfoMode rmode) {
-    return relocatable_int32_constants_.Find(zone(),
-                                             std::make_pair(value, rmode));
+    return relocatable_int32_constants_.Find(std::make_pair(value, rmode));
   }
 
   Node** FindRelocatableInt64Constant(int64_t value, RelocInfoMode rmode) {
-    return relocatable_int64_constants_.Find(zone(),
-                                             std::make_pair(value, rmode));
+    return relocatable_int64_constants_.Find(std::make_pair(value, rmode));
   }
 
   // Return all nodes from the cache.
   void GetCachedNodes(ZoneVector<Node*>* nodes);
 
-  Zone* zone() const { return zone_; }
-
  private:
   Int32NodeCache int32_constants_;
   Int64NodeCache int64_constants_;
+  Int32NodeCache tagged_index_constants_;
   Int32NodeCache float32_constants_;
   Int64NodeCache float64_constants_;
   IntPtrNodeCache external_constants_;
@@ -82,7 +94,6 @@ class CommonNodeCache final {
   IntPtrNodeCache heap_constants_;
   RelocInt32NodeCache relocatable_int32_constants_;
   RelocInt64NodeCache relocatable_int64_constants_;
-  Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(CommonNodeCache);
 };
diff --git a/deps/v8/src/compiler/common-operator-reducer.cc b/deps/v8/src/compiler/common-operator-reducer.cc
index 5dd765527f..95ecb0f820 100644
--- a/deps/v8/src/compiler/common-operator-reducer.cc
+++ b/deps/v8/src/compiler/common-operator-reducer.cc
@@ -21,6 +21,9 @@ namespace {
 
 Decision DecideCondition(JSHeapBroker* broker, Node* const cond) {
   switch (cond->opcode()) {
+    case IrOpcode::kFoldConstant: {
+      return DecideCondition(broker, cond->InputAt(1));
+    }
     case IrOpcode::kInt32Constant: {
       Int32Matcher mcond(cond);
       return mcond.Value() ? Decision::kTrue : Decision::kFalse;
diff --git a/deps/v8/src/compiler/common-operator.cc b/deps/v8/src/compiler/common-operator.cc
index 57cde2ed6e..e548650316 100644
--- a/deps/v8/src/compiler/common-operator.cc
+++ b/deps/v8/src/compiler/common-operator.cc
@@ -257,7 +257,8 @@ size_t hash_value(RelocatablePtrConstantInfo const& p) {
 
 std::ostream& operator<<(std::ostream& os,
                          RelocatablePtrConstantInfo const& p) {
-  return os << p.value() << ", " << p.rmode() << ", " << p.type();
+  return os << p.value() << ", " << static_cast<int>(p.rmode()) << ", "
+            << p.type();
 }
 
 SparseInputMask::InputIterator::InputIterator(
@@ -281,6 +282,15 @@ void SparseInputMask::InputIterator::Advance() {
   bit_mask_ >>= 1;
 }
 
+size_t SparseInputMask::InputIterator::AdvanceToNextRealOrEnd() {
+  DCHECK_NE(bit_mask_, SparseInputMask::kDenseBitMask);
+
+  size_t count = base::bits::CountTrailingZeros(bit_mask_);
+  bit_mask_ >>= count;
+  DCHECK(IsReal() || IsEnd());
+  return count;
+}
+
 Node* SparseInputMask::InputIterator::GetReal() const {
   DCHECK(IsReal());
   return parent_->InputAt(real_index_);
@@ -454,8 +464,6 @@ IfValueParameters const& IfValueParametersOf(const Operator* op) {
   V(IfException, Operator::kKontrol, 0, 1, 1, 1, 1, 1)                        \
   V(Throw, Operator::kKontrol, 0, 1, 1, 0, 0, 1)                              \
   V(Terminate, Operator::kKontrol, 0, 1, 1, 0, 0, 1)                          \
-  V(OsrNormalEntry, Operator::kFoldable, 0, 1, 1, 0, 1, 1)                    \
-  V(OsrLoopEntry, Operator::kFoldable | Operator::kNoThrow, 0, 1, 1, 0, 1, 1) \
   V(LoopExit, Operator::kKontrol, 0, 0, 2, 0, 0, 1)                           \
   V(LoopExitValue, Operator::kPure, 1, 0, 1, 1, 0, 0)                         \
   V(LoopExitEffect, Operator::kNoThrow, 0, 1, 1, 0, 1, 0)                     \
@@ -1159,6 +1167,13 @@ const Operator* CommonOperatorBuilder::Int64Constant(int64_t value) {
       value);                                     // parameter
 }
 
+const Operator* CommonOperatorBuilder::TaggedIndexConstant(int32_t value) {
+  return new (zone()) Operator1<int32_t>(               // --
+      IrOpcode::kTaggedIndexConstant, Operator::kPure,  // opcode
+      "TaggedIndexConstant",                            // name
+      0, 0, 0, 1, 0, 0,                                 // counts
+      value);                                           // parameter
+}
 
 const Operator* CommonOperatorBuilder::Float32Constant(volatile float value) {
   return new (zone()) Operator1<float>(             // --
@@ -1295,6 +1310,13 @@ const Operator* CommonOperatorBuilder::TypeGuard(Type type) {
       type);                                  // parameter
 }
 
+const Operator* CommonOperatorBuilder::FoldConstant() {
+  return new (zone()) Operator(                  // --
+      IrOpcode::kFoldConstant, Operator::kPure,  // opcode
+      "FoldConstant",                            // name
+      2, 0, 0, 1, 0, 0);                         // counts
+}
+
 const Operator* CommonOperatorBuilder::EffectPhi(int effect_input_count) {
   DCHECK_LT(0, effect_input_count);  // Disallow empty effect phis.
   switch (effect_input_count) {
diff --git a/deps/v8/src/compiler/common-operator.h b/deps/v8/src/compiler/common-operator.h
index 2b0dcc7db9..14bb48b073 100644
--- a/deps/v8/src/compiler/common-operator.h
+++ b/deps/v8/src/compiler/common-operator.h
@@ -273,6 +273,11 @@ class SparseInputMask final {
     // current sparse input is real.
     Node* GetReal() const;
 
+    // Advance to the next real value or the end. Only valid if the iterator is
+    // not dense. Returns the number of empty values that were skipped. This can
+    // return 0 and in that case, it does not advance.
+    size_t AdvanceToNextRealOrEnd();
+
     // Get the current sparse input, returning either a real input node if
     // the current sparse input is real, or the given {empty_value} if the
     // current sparse input is empty.
@@ -487,12 +492,11 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
   const Operator* Merge(int control_input_count);
   const Operator* Parameter(int index, const char* debug_name = nullptr);
 
-  const Operator* OsrNormalEntry();
-  const Operator* OsrLoopEntry();
   const Operator* OsrValue(int index);
 
   const Operator* Int32Constant(int32_t);
   const Operator* Int64Constant(int64_t);
+  const Operator* TaggedIndexConstant(int32_t value);
   const Operator* Float32Constant(volatile float);
   const Operator* Float64Constant(volatile double);
   const Operator* ExternalConstant(const ExternalReference&);
@@ -534,6 +538,7 @@ class V8_EXPORT_PRIVATE CommonOperatorBuilder final
   const Operator* Projection(size_t index);
   const Operator* Retain();
   const Operator* TypeGuard(Type type);
+  const Operator* FoldConstant();
 
   // Constructs a new merge or phi operator with the same opcode as {op}, but
   // with {size} inputs.
diff --git a/deps/v8/src/compiler/constant-folding-reducer.cc b/deps/v8/src/compiler/constant-folding-reducer.cc
index 5a903273ed..9649dbda08 100644
--- a/deps/v8/src/compiler/constant-folding-reducer.cc
+++ b/deps/v8/src/compiler/constant-folding-reducer.cc
@@ -11,6 +11,51 @@ namespace v8 {
 namespace internal {
 namespace compiler {
 
+namespace {
+Node* TryGetConstant(JSGraph* jsgraph, Node* node) {
+  Type type = NodeProperties::GetType(node);
+  Node* result;
+  if (type.IsNone()) {
+    result = nullptr;
+  } else if (type.Is(Type::Null())) {
+    result = jsgraph->NullConstant();
+  } else if (type.Is(Type::Undefined())) {
+    result = jsgraph->UndefinedConstant();
+  } else if (type.Is(Type::MinusZero())) {
+    result = jsgraph->MinusZeroConstant();
+  } else if (type.Is(Type::NaN())) {
+    result = jsgraph->NaNConstant();
+  } else if (type.Is(Type::Hole())) {
+    result = jsgraph->TheHoleConstant();
+  } else if (type.IsHeapConstant()) {
+    result = jsgraph->Constant(type.AsHeapConstant()->Ref());
+  } else if (type.Is(Type::PlainNumber()) && type.Min() == type.Max()) {
+    result = jsgraph->Constant(type.Min());
+  } else {
+    result = nullptr;
+  }
+  DCHECK_EQ(result != nullptr, type.IsSingleton());
+  DCHECK_IMPLIES(result != nullptr,
+                 type.Equals(NodeProperties::GetType(result)));
+  return result;
+}
+
+bool IsAlreadyBeingFolded(Node* node) {
+  DCHECK(FLAG_assert_types);
+  if (node->opcode() == IrOpcode::kFoldConstant) return true;
+  for (Edge edge : node->use_edges()) {
+    if (NodeProperties::IsValueEdge(edge) &&
+        edge.from()->opcode() == IrOpcode::kFoldConstant) {
+      // Note: {node} may have gained new value uses since the time it was
+      // "constant-folded", and theses uses should ideally be rewritten as well.
+      // For simplicity, we ignore them here.
+      return true;
+    }
+  }
+  return false;
+}
+}  // namespace
+
 ConstantFoldingReducer::ConstantFoldingReducer(Editor* editor, JSGraph* jsgraph,
                                                JSHeapBroker* broker)
     : AdvancedReducer(editor), jsgraph_(jsgraph), broker_(broker) {}
@@ -19,43 +64,27 @@ ConstantFoldingReducer::~ConstantFoldingReducer() = default;
 
 Reduction ConstantFoldingReducer::Reduce(Node* node) {
   DisallowHeapAccess no_heap_access;
-  // Check if the output type is a singleton.  In that case we already know the
-  // result value and can simply replace the node if it's eliminable.
   if (!NodeProperties::IsConstant(node) && NodeProperties::IsTyped(node) &&
-      node->op()->HasProperty(Operator::kEliminatable)) {
-    // TODO(v8:5303): We must not eliminate FinishRegion here. This special
-    // case can be removed once we have separate operators for value and
-    // effect regions.
-    if (node->opcode() == IrOpcode::kFinishRegion) return NoChange();
-    // We can only constant-fold nodes here, that are known to not cause any
-    // side-effect, may it be a JavaScript observable side-effect or a possible
-    // eager deoptimization exit (i.e. {node} has an operator that doesn't have
-    // the Operator::kNoDeopt property).
-    Type upper = NodeProperties::GetType(node);
-    if (!upper.IsNone()) {
-      Node* replacement = nullptr;
-      if (upper.IsHeapConstant()) {
-        replacement = jsgraph()->Constant(upper.AsHeapConstant()->Ref());
-      } else if (upper.Is(Type::MinusZero())) {
-        Factory* factory = jsgraph()->isolate()->factory();
-        ObjectRef minus_zero(broker(), factory->minus_zero_value());
-        replacement = jsgraph()->Constant(minus_zero);
-      } else if (upper.Is(Type::NaN())) {
-        replacement = jsgraph()->NaNConstant();
-      } else if (upper.Is(Type::Null())) {
-        replacement = jsgraph()->NullConstant();
-      } else if (upper.Is(Type::PlainNumber()) && upper.Min() == upper.Max()) {
-        replacement = jsgraph()->Constant(upper.Min());
-      } else if (upper.Is(Type::Undefined())) {
-        replacement = jsgraph()->UndefinedConstant();
-      }
-      if (replacement) {
-        // Make sure the node has a type.
-        if (!NodeProperties::IsTyped(replacement)) {
-          NodeProperties::SetType(replacement, upper);
-        }
-        ReplaceWithValue(node, replacement);
-        return Changed(replacement);
+      node->op()->HasProperty(Operator::kEliminatable) &&
+      node->opcode() != IrOpcode::kFinishRegion) {
+    Node* constant = TryGetConstant(jsgraph(), node);
+    if (constant != nullptr) {
+      DCHECK(NodeProperties::IsTyped(constant));
+      if (!FLAG_assert_types) {
+        DCHECK_EQ(node->op()->ControlOutputCount(), 0);
+        ReplaceWithValue(node, constant);
+        return Replace(constant);
+      } else if (!IsAlreadyBeingFolded(node)) {
+        // Delay the constant folding (by inserting a FoldConstant operation
+        // instead) in order to keep type assertions meaningful.
+        Node* fold_constant = jsgraph()->graph()->NewNode(
+            jsgraph()->common()->FoldConstant(), node, constant);
+        DCHECK(NodeProperties::IsTyped(fold_constant));
+        ReplaceWithValue(node, fold_constant, node, node);
+        fold_constant->ReplaceInput(0, node);
+        DCHECK(IsAlreadyBeingFolded(node));
+        DCHECK(IsAlreadyBeingFolded(fold_constant));
+        return Changed(node);
       }
     }
   }
diff --git a/deps/v8/src/compiler/dead-code-elimination.cc b/deps/v8/src/compiler/dead-code-elimination.cc
index f39e6cabfb..bab6b7b506 100644
--- a/deps/v8/src/compiler/dead-code-elimination.cc
+++ b/deps/v8/src/compiler/dead-code-elimination.cc
@@ -317,7 +317,10 @@ Reduction DeadCodeElimination::ReduceDeoptimizeOrReturnOrTerminateOrTailCall(
          node->opcode() == IrOpcode::kTailCall);
   Reduction reduction = PropagateDeadControl(node);
   if (reduction.Changed()) return reduction;
-  if (FindDeadInput(node) != nullptr) {
+  // Terminate nodes are not part of actual control flow, so they should never
+  // be replaced with Throw.
+  if (node->opcode() != IrOpcode::kTerminate &&
+      FindDeadInput(node) != nullptr) {
     Node* effect = NodeProperties::GetEffectInput(node, 0);
     Node* control = NodeProperties::GetControlInput(node, 0);
     if (effect->opcode() != IrOpcode::kUnreachable) {
diff --git a/deps/v8/src/compiler/effect-control-linearizer.cc b/deps/v8/src/compiler/effect-control-linearizer.cc
index 3f170df065..d3344b9545 100644
--- a/deps/v8/src/compiler/effect-control-linearizer.cc
+++ b/deps/v8/src/compiler/effect-control-linearizer.cc
@@ -75,6 +75,7 @@ class EffectControlLinearizer {
   void LowerCheckMaps(Node* node, Node* frame_state);
   Node* LowerCompareMaps(Node* node);
   Node* LowerCheckNumber(Node* node, Node* frame_state);
+  Node* LowerCheckClosure(Node* node, Node* frame_state);
   Node* LowerCheckReceiver(Node* node, Node* frame_state);
   Node* LowerCheckReceiverOrNullOrUndefined(Node* node, Node* frame_state);
   Node* LowerCheckString(Node* node, Node* frame_state);
@@ -198,6 +199,7 @@ class EffectControlLinearizer {
   void LowerTransitionAndStoreNonNumberElement(Node* node);
   void LowerRuntimeAbort(Node* node);
   Node* LowerAssertType(Node* node);
+  Node* LowerFoldConstant(Node* node);
   Node* LowerConvertReceiver(Node* node);
   Node* LowerDateNow(Node* node);
 
@@ -235,6 +237,10 @@ class EffectControlLinearizer {
 
   Node* BuildTypedArrayDataPointer(Node* base, Node* external);
 
+  template <typename... Args>
+  Node* CallBuiltin(Builtins::Name builtin, Operator::Properties properties,
+                    Args...);
+
   Node* ChangeInt32ToSmi(Node* value);
   // In pointer compression, we smi-corrupt. This means the upper bits of a Smi
   // are not important. ChangeTaggedInt32ToSmi has a known tagged int32 as input
@@ -903,6 +909,9 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kPoisonIndex:
       result = LowerPoisonIndex(node);
       break;
+    case IrOpcode::kCheckClosure:
+      result = LowerCheckClosure(node, frame_state);
+      break;
     case IrOpcode::kCheckMaps:
       LowerCheckMaps(node, frame_state);
       break;
@@ -1299,6 +1308,9 @@ bool EffectControlLinearizer::TryWireInStateEffect(Node* node,
     case IrOpcode::kDateNow:
       result = LowerDateNow(node);
       break;
+    case IrOpcode::kFoldConstant:
+      result = LowerFoldConstant(node);
+      break;
     default:
       return false;
   }
@@ -1702,6 +1714,30 @@ Node* EffectControlLinearizer::LowerPoisonIndex(Node* node) {
   return index;
 }
 
+Node* EffectControlLinearizer::LowerCheckClosure(Node* node,
+                                                 Node* frame_state) {
+  Handle<FeedbackCell> feedback_cell = FeedbackCellOf(node->op());
+  Node* value = node->InputAt(0);
+
+  // Check that {value} is actually a JSFunction.
+  Node* value_map = __ LoadField(AccessBuilder::ForMap(), value);
+  Node* value_instance_type =
+      __ LoadField(AccessBuilder::ForMapInstanceType(), value_map);
+  Node* check_instance_type =
+      __ Word32Equal(value_instance_type, __ Int32Constant(JS_FUNCTION_TYPE));
+  __ DeoptimizeIfNot(DeoptimizeReason::kWrongCallTarget, FeedbackSource(),
+                     check_instance_type, frame_state);
+
+  // Check that the {value}s feedback vector cell matches the one
+  // we recorded before.
+  Node* value_cell =
+      __ LoadField(AccessBuilder::ForJSFunctionFeedbackCell(), value);
+  Node* check_cell = __ WordEqual(value_cell, __ HeapConstant(feedback_cell));
+  __ DeoptimizeIfNot(DeoptimizeReason::kWrongFeedbackCell, FeedbackSource(),
+                     check_cell, frame_state);
+  return value;
+}
+
 void EffectControlLinearizer::LowerCheckMaps(Node* node, Node* frame_state) {
   CheckMapsParameters const& p = CheckMapsParametersOf(node->op());
   Node* value = node->InputAt(0);
@@ -2380,13 +2416,31 @@ Node* EffectControlLinearizer::LowerCheckedUint32ToTaggedSigned(
 
 Node* EffectControlLinearizer::LowerCheckedUint64Bounds(Node* node,
                                                         Node* frame_state) {
-  CheckParameters const& params = CheckParametersOf(node->op());
   Node* const index = node->InputAt(0);
   Node* const limit = node->InputAt(1);
+  const CheckBoundsParameters& params = CheckBoundsParametersOf(node->op());
 
   Node* check = __ Uint64LessThan(index, limit);
-  __ DeoptimizeIfNot(DeoptimizeReason::kOutOfBounds, params.feedback(), check,
-                     frame_state, IsSafetyCheck::kCriticalSafetyCheck);
+  switch (params.mode()) {
+    case CheckBoundsParameters::kDeoptOnOutOfBounds:
+      __ DeoptimizeIfNot(DeoptimizeReason::kOutOfBounds,
+                         params.check_parameters().feedback(), check,
+                         frame_state, IsSafetyCheck::kCriticalSafetyCheck);
+      break;
+    case CheckBoundsParameters::kAbortOnOutOfBounds: {
+      auto if_abort = __ MakeDeferredLabel();
+      auto done = __ MakeLabel();
+
+      __ Branch(check, &done, &if_abort);
+
+      __ Bind(&if_abort);
+      __ Unreachable();
+      __ Goto(&done);
+
+      __ Bind(&done);
+      break;
+    }
+  }
   return index;
 }
 
@@ -3432,9 +3486,9 @@ Node* EffectControlLinearizer::LowerArgumentsLength(Node* node) {
     __ Goto(&if_adaptor_frame);
 
     __ Bind(&if_adaptor_frame);
-    Node* arguments_length = __ Load(
-        MachineType::TaggedSigned(), arguments_frame,
-        __ IntPtrConstant(ArgumentsAdaptorFrameConstants::kLengthOffset));
+    Node* arguments_length = __ BitcastWordToTaggedSigned(__ Load(
+        MachineType::Pointer(), arguments_frame,
+        __ IntPtrConstant(ArgumentsAdaptorFrameConstants::kLengthOffset)));
 
     Node* rest_length =
         __ SmiSub(arguments_length, __ SmiConstant(formal_parameter_count));
@@ -3457,9 +3511,9 @@ Node* EffectControlLinearizer::LowerArgumentsLength(Node* node) {
     __ Goto(&if_adaptor_frame);
 
     __ Bind(&if_adaptor_frame);
-    Node* arguments_length = __ Load(
-        MachineType::TaggedSigned(), arguments_frame,
-        __ IntPtrConstant(ArgumentsAdaptorFrameConstants::kLengthOffset));
+    Node* arguments_length = __ BitcastWordToTaggedSigned(__ Load(
+        MachineType::Pointer(), arguments_frame,
+        __ IntPtrConstant(ArgumentsAdaptorFrameConstants::kLengthOffset)));
     __ Goto(&done, arguments_length);
 
     __ Bind(&done);
@@ -5421,28 +5475,39 @@ void EffectControlLinearizer::LowerRuntimeAbort(Node* node) {
           __ Int32Constant(1), __ NoContextConstant());
 }
 
+template <typename... Args>
+Node* EffectControlLinearizer::CallBuiltin(Builtins::Name builtin,
+                                           Operator::Properties properties,
+                                           Args... args) {
+  Callable const callable = Builtins::CallableFor(isolate(), builtin);
+  auto call_descriptor = Linkage::GetStubCallDescriptor(
+      graph()->zone(), callable.descriptor(),
+      callable.descriptor().GetStackParameterCount(), CallDescriptor::kNoFlags,
+      properties);
+  return __ Call(call_descriptor, __ HeapConstant(callable.code()), args...,
+                 __ NoContextConstant());
+}
+
 Node* EffectControlLinearizer::LowerAssertType(Node* node) {
   DCHECK_EQ(node->opcode(), IrOpcode::kAssertType);
   Type type = OpParameter<Type>(node->op());
   DCHECK(type.IsRange());
   auto range = type.AsRange();
-
   Node* const input = node->InputAt(0);
   Node* const min = __ NumberConstant(range->Min());
   Node* const max = __ NumberConstant(range->Max());
-
-  {
-    Callable const callable =
-        Builtins::CallableFor(isolate(), Builtins::kCheckNumberInRange);
-    Operator::Properties const properties = node->op()->properties();
-    CallDescriptor::Flags const flags = CallDescriptor::kNoFlags;
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        graph()->zone(), callable.descriptor(),
-        callable.descriptor().GetStackParameterCount(), flags, properties);
-    __ Call(call_descriptor, __ HeapConstant(callable.code()), input, min, max,
-            __ NoContextConstant());
-    return input;
-  }
+  CallBuiltin(Builtins::kCheckNumberInRange, node->op()->properties(), input,
+              min, max);
+  return input;
+}
+
+Node* EffectControlLinearizer::LowerFoldConstant(Node* node) {
+  DCHECK_EQ(node->opcode(), IrOpcode::kFoldConstant);
+  Node* original = node->InputAt(0);
+  Node* constant = node->InputAt(1);
+  CallBuiltin(Builtins::kCheckSameObject, node->op()->properties(), original,
+              constant);
+  return constant;
 }
 
 Node* EffectControlLinearizer::LowerConvertReceiver(Node* node) {
diff --git a/deps/v8/src/compiler/graph-assembler.cc b/deps/v8/src/compiler/graph-assembler.cc
index 09b66c306f..246bf1e229 100644
--- a/deps/v8/src/compiler/graph-assembler.cc
+++ b/deps/v8/src/compiler/graph-assembler.cc
@@ -648,11 +648,20 @@ Node* GraphAssembler::Store(StoreRepresentation rep, Node* object, Node* offset,
                                   effect(), control()));
 }
 
+Node* GraphAssembler::Store(StoreRepresentation rep, Node* object, int offset,
+                            Node* value) {
+  return Store(rep, object, Int32Constant(offset), value);
+}
+
 Node* GraphAssembler::Load(MachineType type, Node* object, Node* offset) {
   return AddNode(graph()->NewNode(machine()->Load(type), object, offset,
                                   effect(), control()));
 }
 
+Node* GraphAssembler::Load(MachineType type, Node* object, int offset) {
+  return Load(type, object, Int32Constant(offset));
+}
+
 Node* GraphAssembler::StoreUnaligned(MachineRepresentation rep, Node* object,
                                      Node* offset, Node* value) {
   Operator const* const op =
@@ -689,6 +698,11 @@ TNode<Number> JSGraphAssembler::PlainPrimitiveToNumber(TNode<Object> value) {
                                           NoContextConstant(), effect()));
 }
 
+Node* GraphAssembler::BitcastWordToTaggedSigned(Node* value) {
+  return AddNode(
+      graph()->NewNode(machine()->BitcastWordToTaggedSigned(), value));
+}
+
 Node* GraphAssembler::BitcastWordToTagged(Node* value) {
   return AddNode(graph()->NewNode(machine()->BitcastWordToTagged(), value,
                                   effect(), control()));
diff --git a/deps/v8/src/compiler/graph-assembler.h b/deps/v8/src/compiler/graph-assembler.h
index 92c37a1860..b9f605ae6e 100644
--- a/deps/v8/src/compiler/graph-assembler.h
+++ b/deps/v8/src/compiler/graph-assembler.h
@@ -87,6 +87,7 @@ class BasicBlock;
   V(Word32Xor)                            \
   V(Word64And)                            \
   V(Word64Equal)                          \
+  V(Word64Or)                             \
   V(WordAnd)                              \
   V(WordEqual)                            \
   V(WordSar)                              \
@@ -302,6 +303,7 @@ class V8_EXPORT_PRIVATE GraphAssembler {
   Node* Float64RoundTruncate(Node* value);
 
   Node* BitcastWordToTagged(Node* value);
+  Node* BitcastWordToTaggedSigned(Node* value);
   Node* BitcastTaggedToWord(Node* value);
   Node* BitcastTaggedToWordForTagAndSmiBits(Node* value);
 
@@ -309,7 +311,9 @@ class V8_EXPORT_PRIVATE GraphAssembler {
   Node* Checkpoint(FrameState frame_state);
 
   Node* Store(StoreRepresentation rep, Node* object, Node* offset, Node* value);
+  Node* Store(StoreRepresentation rep, Node* object, int offset, Node* value);
   Node* Load(MachineType type, Node* object, Node* offset);
+  Node* Load(MachineType type, Node* object, int offset);
 
   Node* StoreUnaligned(MachineRepresentation rep, Node* object, Node* offset,
                        Node* value);
diff --git a/deps/v8/src/compiler/heap-refs.h b/deps/v8/src/compiler/heap-refs.h
index c9bb6bf9d1..deeaa89c1e 100644
--- a/deps/v8/src/compiler/heap-refs.h
+++ b/deps/v8/src/compiler/heap-refs.h
@@ -12,6 +12,8 @@
 #include "src/objects/instance-type.h"
 
 namespace v8 {
+class CFunctionInfo;
+
 namespace internal {
 
 class BytecodeArray;
@@ -490,7 +492,7 @@ class FeedbackCellRef : public HeapObjectRef {
   DEFINE_REF_CONSTRUCTOR(FeedbackCell, HeapObjectRef)
 
   Handle<FeedbackCell> object() const;
-
+  base::Optional<SharedFunctionInfoRef> shared_function_info() const;
   HeapObjectRef value() const;
 };
 
@@ -500,9 +502,11 @@ class FeedbackVectorRef : public HeapObjectRef {
 
   Handle<FeedbackVector> object() const;
 
+  SharedFunctionInfoRef shared_function_info() const;
   double invocation_count() const;
 
   void Serialize();
+  bool serialized() const;
   FeedbackCellRef GetClosureFeedbackCell(int index) const;
 };
 
@@ -659,6 +663,8 @@ class FunctionTemplateInfoRef : public HeapObjectRef {
 
   void SerializeCallCode();
   base::Optional<CallHandlerInfoRef> call_code() const;
+  Address c_function() const;
+  const CFunctionInfo* c_signature() const;
 
   HolderLookupResult LookupHolderOfExpectedType(
       MapRef receiver_map,
diff --git a/deps/v8/src/compiler/int64-lowering.cc b/deps/v8/src/compiler/int64-lowering.cc
index bc6267f375..ad68d34d03 100644
--- a/deps/v8/src/compiler/int64-lowering.cc
+++ b/deps/v8/src/compiler/int64-lowering.cc
@@ -1023,14 +1023,12 @@ bool Int64Lowering::DefaultLowering(Node* node, bool low_word_only) {
   return something_changed;
 }
 
-CallDescriptor* Int64Lowering::LowerCallDescriptor(
+const CallDescriptor* Int64Lowering::LowerCallDescriptor(
     const CallDescriptor* call_descriptor) {
   if (special_case_) {
-    if (call_descriptor == special_case_->bigint_to_i64_call_descriptor) {
-      return special_case_->bigint_to_i32_pair_call_descriptor;
-    }
-    if (call_descriptor == special_case_->i64_to_bigint_call_descriptor) {
-      return special_case_->i32_pair_to_bigint_call_descriptor;
+    auto replacement = special_case_->replacements.find(call_descriptor);
+    if (replacement != special_case_->replacements.end()) {
+      return replacement->second;
     }
   }
   return GetI32WasmCallDescriptor(zone(), call_descriptor);
diff --git a/deps/v8/src/compiler/int64-lowering.h b/deps/v8/src/compiler/int64-lowering.h
index 0190d3a9c4..944d2bc32a 100644
--- a/deps/v8/src/compiler/int64-lowering.h
+++ b/deps/v8/src/compiler/int64-lowering.h
@@ -24,19 +24,9 @@ namespace compiler {
 
 // Struct for CallDescriptors that need special lowering.
 struct V8_EXPORT_PRIVATE Int64LoweringSpecialCase {
-  Int64LoweringSpecialCase()
-      : bigint_to_i64_call_descriptor(nullptr),
-        i64_to_bigint_call_descriptor(nullptr),
-        bigint_to_i32_pair_call_descriptor(nullptr),
-        i32_pair_to_bigint_call_descriptor(nullptr) {}
-
-  // CallDescriptors that need special lowering.
-  CallDescriptor* bigint_to_i64_call_descriptor;
-  CallDescriptor* i64_to_bigint_call_descriptor;
-
-  // The replacement CallDescriptors.
-  CallDescriptor* bigint_to_i32_pair_call_descriptor;
-  CallDescriptor* i32_pair_to_bigint_call_descriptor;
+  // Map from CallDescriptors that should be replaced, to the replacement
+  // CallDescriptors.
+  std::unordered_map<const CallDescriptor*, const CallDescriptor*> replacements;
 };
 
 class V8_EXPORT_PRIVATE Int64Lowering {
@@ -74,7 +64,8 @@ class V8_EXPORT_PRIVATE Int64Lowering {
   void LowerWord64AtomicBinop(Node* node, const Operator* op);
   void LowerWord64AtomicNarrowOp(Node* node, const Operator* op);
 
-  CallDescriptor* LowerCallDescriptor(const CallDescriptor* call_descriptor);
+  const CallDescriptor* LowerCallDescriptor(
+      const CallDescriptor* call_descriptor);
 
   void ReplaceNode(Node* old, Node* new_low, Node* new_high);
   bool HasReplacementLow(Node* node);
diff --git a/deps/v8/src/compiler/js-call-reducer.cc b/deps/v8/src/compiler/js-call-reducer.cc
index dc4e4000ca..3fb41a8809 100644
--- a/deps/v8/src/compiler/js-call-reducer.cc
+++ b/deps/v8/src/compiler/js-call-reducer.cc
@@ -6,7 +6,9 @@
 
 #include <functional>
 
+#include "include/v8-fast-api-calls.h"
 #include "src/api/api-inl.h"
+#include "src/base/small-vector.h"
 #include "src/builtins/builtins-promise.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/codegen/code-factory.h"
@@ -864,6 +866,88 @@ class PromiseBuiltinReducerAssembler : public JSCallReducerAssembler {
   }
 };
 
+class FastApiCallReducerAssembler : public JSCallReducerAssembler {
+ public:
+  FastApiCallReducerAssembler(JSGraph* jsgraph, Zone* zone, Node* node,
+                              Address c_function,
+                              const CFunctionInfo* c_signature)
+      : JSCallReducerAssembler(jsgraph, zone, node),
+        c_function_(c_function),
+        c_signature_(c_signature) {
+    DCHECK_EQ(IrOpcode::kJSCall, node->opcode());
+    DCHECK_NE(c_function_, kNullAddress);
+    CHECK_NOT_NULL(c_signature_);
+  }
+
+  TNode<Object> ReduceFastApiCall() {
+    int c_arg_count = c_signature_->ArgumentCount();
+    Node* function_node =
+        ExternalConstant(ExternalReference::Create(c_function_));
+    base::SmallVector<Node*, kInlineSize + kExtraInputsCount> inputs(0);
+    inputs.emplace_back(function_node);
+    int wrapper_object_index = isolate()->embedder_wrapper_object_index();
+    CHECK_GE(wrapper_object_index, 0);
+    for (int i = 0; i < c_arg_count; ++i) {
+      if (i + kFunctionArgCount < ValueInputCount()) {
+        inputs.emplace_back(ConvertArgumentIfJSWrapper(
+            c_signature_->ArgumentInfo(i).GetType(),
+            ValueInput(i + kFunctionArgCount), wrapper_object_index));
+      } else {
+        inputs.emplace_back(UndefinedConstant());
+      }
+    }
+    inputs.emplace_back(effect());
+    inputs.emplace_back(control());
+
+    return FastApiCall(inputs);
+  }
+
+ private:
+  static constexpr int kFunctionArgCount = 1;
+  static constexpr int kExtraInputsCount =
+      kFunctionArgCount + 2;  // effect, control
+  static constexpr int kInlineSize = 10;
+
+  TNode<Object> FastApiCall(
+      base::SmallVector<Node*, kInlineSize + kExtraInputsCount> const& inputs) {
+    return AddNode<Object>(
+        graph()->NewNode(simplified()->FastApiCall(c_signature_, feedback()),
+                         static_cast<int>(inputs.size()), inputs.begin()));
+  }
+
+  TNode<RawPtrT> UnwrapApiObject(TNode<JSObject> node,
+                                 int wrapper_object_index) {
+    const int offset =
+        Internals::kJSObjectHeaderSize +
+        (Internals::kEmbedderDataSlotSize * wrapper_object_index);
+
+    FieldAccess access(kTaggedBase, offset, MaybeHandle<Name>(),
+                       MaybeHandle<Map>(), Type::Any(), MachineType::Pointer(),
+                       WriteBarrierKind::kNoWriteBarrier);
+    TNode<RawPtrT> load = AddNode<RawPtrT>(graph()->NewNode(
+        simplified()->LoadField(access), node, effect(), control()));
+    return load;
+  }
+
+  Node* ConvertArgumentIfJSWrapper(CTypeInfo::Type type, TNode<Object> node,
+                                   int wrapper_object_index) {
+    switch (type) {
+      case CTypeInfo::Type::kUnwrappedApiObject:
+        // This call assumes that {node} is a JSObject with an internal field
+        // set to a C pointer. It should fail in all other cases.
+        // TODO(mslekova): Implement instanceOf check for the C pointer type.
+        // TODO(mslekova): Introduce a GraphAssembler primitive for safe cast.
+        return UnwrapApiObject(TNode<JSObject>::UncheckedCast(node),
+                               wrapper_object_index);
+      default:
+        return node;
+    }
+  }
+
+  const Address c_function_;
+  const CFunctionInfo* const c_signature_;
+};
+
 TNode<Number> JSCallReducerAssembler::SpeculativeToNumber(
     TNode<Object> value, NumberOperationHint hint) {
   return AddNode<Number>(
@@ -3368,8 +3452,9 @@ Reduction JSCallReducer::ReduceCallApiFunction(
       // See if we can constant-fold the compatible receiver checks.
       HolderLookupResult api_holder =
           function_template_info.LookupHolderOfExpectedType(first_receiver_map);
-      if (api_holder.lookup == CallOptimization::kHolderNotFound)
+      if (api_holder.lookup == CallOptimization::kHolderNotFound) {
         return inference.NoChange();
+      }
 
       // Check that all {receiver_maps} are actually JSReceiver maps and
       // that the {function_template_info} accepts them without access
@@ -3471,6 +3556,18 @@ Reduction JSCallReducer::ReduceCallApiFunction(
                                        << function_template_info);
     return NoChange();
   }
+
+  Address c_function = function_template_info.c_function();
+
+  if (FLAG_turbo_fast_api_calls && c_function != kNullAddress) {
+    const CFunctionInfo* c_signature = function_template_info.c_signature();
+    FastApiCallReducerAssembler a(jsgraph(), graph()->zone(), node, c_function,
+                                  c_signature);
+    Node* c_call = a.ReduceFastApiCall();
+    ReplaceWithSubgraph(&a, c_call);
+    return Replace(c_call);
+  }
+
   CallHandlerInfoRef call_handler_info = *function_template_info.call_code();
   Callable call_api_callback = CodeFactory::CallApiCallback(isolate());
   CallInterfaceDescriptor cid = call_api_callback.descriptor();
@@ -3733,7 +3830,7 @@ namespace {
 
 bool ShouldUseCallICFeedback(Node* node) {
   HeapObjectMatcher m(node);
-  if (m.HasValue() || m.IsJSCreateClosure()) {
+  if (m.HasValue() || m.IsCheckClosure() || m.IsJSCreateClosure()) {
     // Don't use CallIC feedback when we know the function
     // being called, i.e. either know the closure itself or
     // at least the SharedFunctionInfo.
@@ -3827,9 +3924,14 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
   // just immediately try to inline based on the SharedFunctionInfo,
   // since TurboFan generally doesn't inline cross-context, and hence
   // the {target} must have the same native context as the call site.
+  // Same if the {target} is the result of a CheckClosure operation.
   if (target->opcode() == IrOpcode::kJSCreateClosure) {
     CreateClosureParameters const& p = CreateClosureParametersOf(target->op());
     return ReduceJSCall(node, SharedFunctionInfoRef(broker(), p.shared_info()));
+  } else if (target->opcode() == IrOpcode::kCheckClosure) {
+    FeedbackCellRef cell(broker(), FeedbackCellOf(target->op()));
+    return ReduceJSCall(node,
+                        cell.value().AsFeedbackVector().shared_function_info());
   }
 
   // If {target} is the result of a JSCreateBoundFunction operation,
@@ -3898,8 +4000,32 @@ Reduction JSCallReducer::ReduceJSCall(Node* node) {
     // Try to further reduce the JSCall {node}.
     Reduction const reduction = ReduceJSCall(node);
     return reduction.Changed() ? reduction : Changed(node);
-  }
+  } else if (feedback_target.has_value() && feedback_target->IsFeedbackCell()) {
+    FeedbackCellRef feedback_cell(
+        broker(), feedback_target.value().AsFeedbackCell().object());
+    if (feedback_cell.value().IsFeedbackVector()) {
+      // Check that {target} is a closure with given {feedback_cell},
+      // which uniquely identifies a given function inside a native context.
+      FeedbackVectorRef feedback_vector =
+          feedback_cell.value().AsFeedbackVector();
+      if (!feedback_vector.serialized()) {
+        TRACE_BROKER_MISSING(
+            broker(), "feedback vector, not serialized: " << feedback_vector);
+        return NoChange();
+      }
+      Node* target_closure = effect =
+          graph()->NewNode(simplified()->CheckClosure(feedback_cell.object()),
+                           target, effect, control);
+
+      // Specialize the JSCall node to the {target_closure}.
+      NodeProperties::ReplaceValueInput(node, target_closure, 0);
+      NodeProperties::ReplaceEffectInput(node, effect);
 
+      // Try to further reduce the JSCall {node}.
+      Reduction const reduction = ReduceJSCall(node);
+      return reduction.Changed() ? reduction : Changed(node);
+    }
+  }
   return NoChange();
 }
 
@@ -6403,13 +6529,8 @@ Reduction JSCallReducer::ReduceTypedArrayPrototypeToStringTag(Node* node) {
         jsgraph()->Constant(TYPE##_ELEMENTS -                          \
                             FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND));   \
     control = graph()->NewNode(common()->Branch(), check, control);    \
-    if (should_disallow_heap_access()) {                               \
-      values.push_back(jsgraph()->Constant(                            \
-          broker()->GetTypedArrayStringTag(TYPE##_ELEMENTS)));         \
-    } else {                                                           \
-      values.push_back(jsgraph()->HeapConstant(                        \
-          factory()->InternalizeUtf8String(#Type "Array")));           \
-    }                                                                  \
+    values.push_back(jsgraph()->Constant(                              \
+        broker()->GetTypedArrayStringTag(TYPE##_ELEMENTS)));           \
     effects.push_back(effect);                                         \
     controls.push_back(graph()->NewNode(common()->IfTrue(), control)); \
     control = graph()->NewNode(common()->IfFalse(), control);          \
diff --git a/deps/v8/src/compiler/js-create-lowering.cc b/deps/v8/src/compiler/js-create-lowering.cc
index 6f76cb7c78..d0059030d5 100644
--- a/deps/v8/src/compiler/js-create-lowering.cc
+++ b/deps/v8/src/compiler/js-create-lowering.cc
@@ -256,10 +256,12 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       }
     }
     UNREACHABLE();
-  } else if (outer_state->opcode() == IrOpcode::kFrameState) {
-    // Use inline allocation for all mapped arguments objects within inlined
-    // (i.e. non-outermost) frames, independent of the object size.
-    if (type == CreateArgumentsType::kMappedArguments) {
+  }
+  // Use inline allocation for all mapped arguments objects within inlined
+  // (i.e. non-outermost) frames, independent of the object size.
+  DCHECK_EQ(outer_state->opcode(), IrOpcode::kFrameState);
+  switch (type) {
+    case CreateArgumentsType::kMappedArguments: {
       Node* const callee = NodeProperties::GetValueInput(node, 0);
       Node* const context = NodeProperties::GetContextInput(node);
       Node* effect = NodeProperties::GetEffectInput(node);
@@ -300,7 +302,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       RelaxControls(node);
       a.FinishAndChange(node);
       return Changed(node);
-    } else if (type == CreateArgumentsType::kUnmappedArguments) {
+    }
+    case CreateArgumentsType::kUnmappedArguments: {
       // Use inline allocation for all unmapped arguments objects within inlined
       // (i.e. non-outermost) frames, independent of the object size.
       Node* effect = NodeProperties::GetEffectInput(node);
@@ -335,7 +338,8 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       RelaxControls(node);
       a.FinishAndChange(node);
       return Changed(node);
-    } else if (type == CreateArgumentsType::kRestParameter) {
+    }
+    case CreateArgumentsType::kRestParameter: {
       int start_index = shared.internal_formal_parameter_count();
       // Use inline allocation for all unmapped arguments objects within inlined
       // (i.e. non-outermost) frames, independent of the object size.
@@ -378,8 +382,7 @@ Reduction JSCreateLowering::ReduceJSCreateArguments(Node* node) {
       return Changed(node);
     }
   }
-
-  return NoChange();
+  UNREACHABLE();
 }
 
 Reduction JSCreateLowering::ReduceJSCreateGeneratorObject(Node* node) {
@@ -1421,9 +1424,9 @@ Node* JSCreateLowering::AllocateArguments(Node* effect, Node* control,
   a.AllocateArray(argument_count,
                   MapRef(broker(), factory()->fixed_array_map()));
   for (int i = 0; i < argument_count; ++i, ++parameters_it) {
-    DCHECK_NOT_NULL((*parameters_it).node);
+    DCHECK_NOT_NULL(parameters_it.node());
     a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
-            (*parameters_it).node);
+            parameters_it.node());
   }
   return a.Finish();
 }
@@ -1452,9 +1455,9 @@ Node* JSCreateLowering::AllocateRestArguments(Node* effect, Node* control,
   AllocationBuilder a(jsgraph(), effect, control);
   a.AllocateArray(num_elements, MapRef(broker(), factory()->fixed_array_map()));
   for (int i = 0; i < num_elements; ++i, ++parameters_it) {
-    DCHECK_NOT_NULL((*parameters_it).node);
+    DCHECK_NOT_NULL(parameters_it.node());
     a.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
-            (*parameters_it).node);
+            parameters_it.node());
   }
   return a.Finish();
 }
@@ -1496,9 +1499,9 @@ Node* JSCreateLowering::AllocateAliasedArguments(
              jsgraph()->TheHoleConstant());
   }
   for (int i = mapped_count; i < argument_count; ++i, ++parameters_it) {
-    DCHECK_NOT_NULL((*parameters_it).node);
+    DCHECK_NOT_NULL(parameters_it.node());
     aa.Store(AccessBuilder::ForFixedArrayElement(), jsgraph()->Constant(i),
-             (*parameters_it).node);
+             parameters_it.node());
   }
   Node* arguments = aa.Finish();
 
diff --git a/deps/v8/src/compiler/js-generic-lowering.cc b/deps/v8/src/compiler/js-generic-lowering.cc
index e565d9ee40..7a3610fff2 100644
--- a/deps/v8/src/compiler/js-generic-lowering.cc
+++ b/deps/v8/src/compiler/js-generic-lowering.cc
@@ -168,7 +168,8 @@ void JSGenericLowering::LowerJSLoadProperty(Node* node) {
   const PropertyAccess& p = PropertyAccessOf(node->op());
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
-  node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 2,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable = Builtins::CallableFor(
         isolate(), ShouldUseMegamorphicLoadBuiltin(p.feedback(), broker())
@@ -198,7 +199,8 @@ void JSGenericLowering::LowerJSLoadNamed(Node* node) {
     ReplaceWithStubCall(node, callable, flags);
     return;
   }
-  node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 2,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable = Builtins::CallableFor(
         isolate(), ShouldUseMegamorphicLoadBuiltin(p.feedback(), broker())
@@ -222,7 +224,8 @@ void JSGenericLowering::LowerJSLoadGlobal(Node* node) {
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.name()));
-  node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 1,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable = CodeFactory::LoadGlobalIC(isolate(), p.typeof_mode());
     ReplaceWithStubCall(node, callable, flags);
@@ -252,7 +255,8 @@ void JSGenericLowering::LowerJSStoreProperty(Node* node) {
   PropertyAccess const& p = PropertyAccessOf(node->op());
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
-  node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 3,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable =
         Builtins::CallableFor(isolate(), Builtins::kKeyedStoreICTrampoline);
@@ -276,7 +280,8 @@ void JSGenericLowering::LowerJSStoreNamed(Node* node) {
     ReplaceWithRuntimeCall(node, Runtime::kSetNamedProperty);
     return;
   }
-  node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 3,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable =
         Builtins::CallableFor(isolate(), Builtins::kStoreICTrampoline);
@@ -295,7 +300,8 @@ void JSGenericLowering::LowerJSStoreNamedOwn(Node* node) {
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
-  node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 3,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable = CodeFactory::StoreOwnIC(isolate());
     ReplaceWithStubCall(node, callable, flags);
@@ -313,7 +319,8 @@ void JSGenericLowering::LowerJSStoreGlobal(Node* node) {
   Node* frame_state = NodeProperties::GetFrameStateInput(node);
   Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.name()));
-  node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 2,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   if (outer_state->opcode() != IrOpcode::kFrameState) {
     Callable callable =
         Builtins::CallableFor(isolate(), Builtins::kStoreGlobalICTrampoline);
@@ -332,7 +339,7 @@ void JSGenericLowering::LowerJSStoreDataPropertyInLiteral(Node* node) {
   RelaxControls(node);
   node->InsertInputs(zone(), 4, 2);
   node->ReplaceInput(4, jsgraph()->HeapConstant(p.feedback().vector));
-  node->ReplaceInput(5, jsgraph()->SmiConstant(p.feedback().index()));
+  node->ReplaceInput(5, jsgraph()->TaggedIndexConstant(p.feedback().index()));
   ReplaceWithRuntimeCall(node, Runtime::kDefineDataPropertyInLiteral);
 }
 
@@ -342,7 +349,8 @@ void JSGenericLowering::LowerJSStoreInArrayLiteral(Node* node) {
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   FeedbackParameter const& p = FeedbackParameterOf(node->op());
   RelaxControls(node);
-  node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 3,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->InsertInput(zone(), 4, jsgraph()->HeapConstant(p.feedback().vector));
   ReplaceWithStubCall(node, callable, flags);
 }
@@ -550,7 +558,8 @@ void JSGenericLowering::LowerJSCreateLiteralArray(Node* node) {
   CreateLiteralParameters const& p = CreateLiteralParametersOf(node->op());
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.feedback().vector));
-  node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 1,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->InsertInput(zone(), 2, jsgraph()->HeapConstant(p.constant()));
 
   // Use the CreateShallowArrayLiteratlr builtin only for shallow boilerplates
@@ -574,7 +583,8 @@ void JSGenericLowering::LowerJSCreateEmptyLiteralArray(Node* node) {
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   FeedbackParameter const& p = FeedbackParameterOf(node->op());
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.feedback().vector));
-  node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 1,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->RemoveInput(4);  // control
   Callable callable =
       Builtins::CallableFor(isolate(), Builtins::kCreateEmptyArrayLiteral);
@@ -592,7 +602,8 @@ void JSGenericLowering::LowerJSCreateLiteralObject(Node* node) {
   CreateLiteralParameters const& p = CreateLiteralParametersOf(node->op());
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.feedback().vector));
-  node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 1,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->InsertInput(zone(), 2, jsgraph()->HeapConstant(p.constant()));
   node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.flags()));
 
@@ -615,7 +626,8 @@ void JSGenericLowering::LowerJSCloneObject(Node* node) {
   Callable callable =
       Builtins::CallableFor(isolate(), Builtins::kCloneObjectIC);
   node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.flags()));
-  node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 2,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->InsertInput(zone(), 3, jsgraph()->HeapConstant(p.feedback().vector));
   ReplaceWithStubCall(node, callable, flags);
 }
@@ -630,7 +642,8 @@ void JSGenericLowering::LowerJSCreateLiteralRegExp(Node* node) {
   Callable callable =
       Builtins::CallableFor(isolate(), Builtins::kCreateRegExpLiteral);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(p.feedback().vector));
-  node->InsertInput(zone(), 1, jsgraph()->SmiConstant(p.feedback().index()));
+  node->InsertInput(zone(), 1,
+                    jsgraph()->TaggedIndexConstant(p.feedback().index()));
   node->InsertInput(zone(), 2, jsgraph()->HeapConstant(p.constant()));
   node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.flags()));
   ReplaceWithStubCall(node, callable, flags);
diff --git a/deps/v8/src/compiler/js-graph.cc b/deps/v8/src/compiler/js-graph.cc
index beed7820b4..bd733ae413 100644
--- a/deps/v8/src/compiler/js-graph.cc
+++ b/deps/v8/src/compiler/js-graph.cc
@@ -160,6 +160,8 @@ DEFINE_GETTER(NullConstant, HeapConstant(factory()->null_value()))
 
 DEFINE_GETTER(ZeroConstant, NumberConstant(0.0))
 
+DEFINE_GETTER(MinusZeroConstant, NumberConstant(-0.0))
+
 DEFINE_GETTER(OneConstant, NumberConstant(1.0))
 
 DEFINE_GETTER(MinusOneConstant, NumberConstant(-1.0))
diff --git a/deps/v8/src/compiler/js-graph.h b/deps/v8/src/compiler/js-graph.h
index 83c81b1010..f965451e35 100644
--- a/deps/v8/src/compiler/js-graph.h
+++ b/deps/v8/src/compiler/js-graph.h
@@ -99,9 +99,10 @@ class V8_EXPORT_PRIVATE JSGraph : public MachineGraph {
   V(FalseConstant)                                \
   V(NullConstant)                                 \
   V(ZeroConstant)                                 \
+  V(MinusZeroConstant)                            \
   V(OneConstant)                                  \
-  V(NaNConstant)                                  \
   V(MinusOneConstant)                             \
+  V(NaNConstant)                                  \
   V(EmptyStateValues)                             \
   V(SingleDeadTypedStateValues)
 
diff --git a/deps/v8/src/compiler/js-heap-broker.cc b/deps/v8/src/compiler/js-heap-broker.cc
index 27df7fc4e9..6acc77cdcc 100644
--- a/deps/v8/src/compiler/js-heap-broker.cc
+++ b/deps/v8/src/compiler/js-heap-broker.cc
@@ -9,6 +9,7 @@
 #include <algorithm>
 #endif
 
+#include "include/v8-fast-api-calls.h"
 #include "src/api/api-inl.h"
 #include "src/ast/modules.h"
 #include "src/codegen/code-factory.h"
@@ -226,6 +227,8 @@ class FunctionTemplateInfoData : public HeapObjectData {
 
   void SerializeCallCode(JSHeapBroker* broker);
   CallHandlerInfoData* call_code() const { return call_code_; }
+  Address c_function() const { return c_function_; }
+  const CFunctionInfo* c_signature() const { return c_signature_; }
   KnownReceiversMap& known_receivers() { return known_receivers_; }
 
  private:
@@ -234,6 +237,8 @@ class FunctionTemplateInfoData : public HeapObjectData {
   bool has_call_code_ = false;
 
   CallHandlerInfoData* call_code_ = nullptr;
+  const Address c_function_;
+  const CFunctionInfo* const c_signature_;
   KnownReceiversMap known_receivers_;
 };
 
@@ -257,6 +262,8 @@ FunctionTemplateInfoData::FunctionTemplateInfoData(
     JSHeapBroker* broker, ObjectData** storage,
     Handle<FunctionTemplateInfo> object)
     : HeapObjectData(broker, storage, object),
+      c_function_(v8::ToCData<Address>(object->GetCFunction())),
+      c_signature_(v8::ToCData<CFunctionInfo*>(object->GetCSignature())),
       known_receivers_(broker->zone()) {
   auto function_template_info = Handle<FunctionTemplateInfo>::cast(object);
   is_signature_undefined_ =
@@ -821,9 +828,12 @@ StringData::StringData(JSHeapBroker* broker, ObjectData** storage,
       is_external_string_(object->IsExternalString()),
       is_seq_string_(object->IsSeqString()),
       chars_as_strings_(broker->zone()) {
-  int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_BINARY;
   if (length_ <= kMaxLengthForDoubleConversion) {
-    to_number_ = StringToDouble(broker->isolate(), object, flags);
+    const int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_BINARY;
+    uc16 buffer[kMaxLengthForDoubleConversion];
+    String::WriteToFlat(*object, buffer, 0, length_);
+    Vector<const uc16> v(buffer, length_);
+    to_number_ = StringToDouble(v, flags);
   }
 }
 
@@ -1353,7 +1363,13 @@ class FeedbackVectorData : public HeapObjectData {
 
   double invocation_count() const { return invocation_count_; }
 
+  SharedFunctionInfoData* shared_function_info() {
+    CHECK(serialized_);
+    return shared_function_info_;
+  }
+
   void Serialize(JSHeapBroker* broker);
+  bool serialized() const { return serialized_; }
   FeedbackCellData* GetClosureFeedbackCell(JSHeapBroker* broker,
                                            int index) const;
 
@@ -1361,6 +1377,7 @@ class FeedbackVectorData : public HeapObjectData {
   double const invocation_count_;
 
   bool serialized_ = false;
+  SharedFunctionInfoData* shared_function_info_;
   ZoneVector<ObjectData*> closure_feedback_cell_array_;
 };
 
@@ -1392,6 +1409,9 @@ void FeedbackVectorData::Serialize(JSHeapBroker* broker) {
 
   TraceScope tracer(broker, this, "FeedbackVectorData::Serialize");
   Handle<FeedbackVector> vector = Handle<FeedbackVector>::cast(object());
+  Handle<SharedFunctionInfo> sfi(vector->shared_function_info(),
+                                 broker->isolate());
+  shared_function_info_ = broker->GetOrCreateData(sfi)->AsSharedFunctionInfo();
   DCHECK(closure_feedback_cell_array_.empty());
   int length = vector->closure_feedback_cell_array().length();
   closure_feedback_cell_array_.reserve(length);
@@ -2510,23 +2530,17 @@ void JSHeapBroker::CollectArrayAndObjectPrototypes() {
   CHECK(!array_and_object_prototypes_.empty());
 }
 
-void JSHeapBroker::SerializeTypedArrayStringTags() {
-#define TYPED_ARRAY_STRING_TAG(Type, type, TYPE, ctype)              \
-  do {                                                               \
-    ObjectData* data = GetOrCreateData(                              \
-        isolate()->factory()->InternalizeUtf8String(#Type "Array")); \
-    typed_array_string_tags_.push_back(data);                        \
-  } while (false);
-
-  TYPED_ARRAYS(TYPED_ARRAY_STRING_TAG)
-#undef TYPED_ARRAY_STRING_TAG
-}
-
 StringRef JSHeapBroker::GetTypedArrayStringTag(ElementsKind kind) {
   DCHECK(IsTypedArrayElementsKind(kind));
-  size_t idx = kind - FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND;
-  CHECK_LT(idx, typed_array_string_tags_.size());
-  return StringRef(this, typed_array_string_tags_[idx]);
+  switch (kind) {
+#define TYPED_ARRAY_STRING_TAG(Type, type, TYPE, ctype) \
+  case ElementsKind::TYPE##_ELEMENTS:                   \
+    return StringRef(this, isolate()->factory()->Type##Array_string());
+    TYPED_ARRAYS(TYPED_ARRAY_STRING_TAG)
+#undef TYPED_ARRAY_STRING_TAG
+    default:
+      UNREACHABLE();
+  }
 }
 
 bool JSHeapBroker::ShouldBeSerializedForCompilation(
@@ -2593,7 +2607,6 @@ void JSHeapBroker::InitializeAndStartSerializing(
   target_native_context().Serialize();
 
   CollectArrayAndObjectPrototypes();
-  SerializeTypedArrayStringTags();
 
   // Serialize Cells
   Factory* const f = isolate()->factory();
@@ -3676,6 +3689,20 @@ Address CallHandlerInfoRef::callback() const {
   return HeapObjectRef::data()->AsCallHandlerInfo()->callback();
 }
 
+Address FunctionTemplateInfoRef::c_function() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    return v8::ToCData<Address>(object()->GetCFunction());
+  }
+  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_function();
+}
+
+const CFunctionInfo* FunctionTemplateInfoRef::c_signature() const {
+  if (broker()->mode() == JSHeapBroker::kDisabled) {
+    return v8::ToCData<CFunctionInfo*>(object()->GetCSignature());
+  }
+  return HeapObjectRef::data()->AsFunctionTemplateInfo()->c_signature();
+}
+
 bool StringRef::IsSeqString() const {
   IF_ACCESS_FROM_HEAP_C(String, IsSeqString);
   return data()->AsString()->is_seq_string();
@@ -3694,6 +3721,22 @@ ScopeInfoRef NativeContextRef::scope_info() const {
   return ScopeInfoRef(broker(), data()->AsNativeContext()->scope_info());
 }
 
+SharedFunctionInfoRef FeedbackVectorRef::shared_function_info() const {
+  if (data_->should_access_heap()) {
+    DCHECK(data_->kind() != ObjectDataKind::kUnserializedReadOnlyHeapObject);
+    AllowHandleAllocationIf allow_handle_allocation(data()->kind(),
+                                                    broker()->mode());
+    AllowHandleDereferenceIf allow_handle_dereference(data()->kind(),
+                                                      broker()->mode());
+    return SharedFunctionInfoRef(
+        broker(),
+        handle(object()->shared_function_info(), broker()->isolate()));
+  }
+
+  return SharedFunctionInfoRef(
+      broker(), data()->AsFeedbackVector()->shared_function_info());
+}
+
 MapRef NativeContextRef::GetFunctionMapFromIndex(int index) const {
   DCHECK_GE(index, Context::FIRST_FUNCTION_MAP_INDEX);
   DCHECK_LE(index, Context::LAST_FUNCTION_MAP_INDEX);
@@ -4007,10 +4050,27 @@ Float64 FixedDoubleArrayData::Get(int i) const {
   return contents_[i];
 }
 
+base::Optional<SharedFunctionInfoRef> FeedbackCellRef::shared_function_info()
+    const {
+  if (value().IsFeedbackVector()) {
+    FeedbackVectorRef vector = value().AsFeedbackVector();
+    if (vector.serialized()) {
+      return value().AsFeedbackVector().shared_function_info();
+    }
+  }
+  return base::nullopt;
+}
+
 void FeedbackVectorRef::Serialize() {
   data()->AsFeedbackVector()->Serialize(broker());
 }
 
+bool FeedbackVectorRef::serialized() const {
+  DCHECK(data_->kind() != ObjectDataKind::kUnserializedReadOnlyHeapObject);
+  if (data_->should_access_heap()) return true;
+  return data()->AsFeedbackVector()->serialized();
+}
+
 bool NameRef::IsUniqueName() const {
   // Must match Name::IsUniqueName.
   return IsInternalizedString() || IsSymbol();
@@ -4430,7 +4490,6 @@ GlobalAccessFeedback::GlobalAccessFeedback(PropertyCellRef cell,
 
 GlobalAccessFeedback::GlobalAccessFeedback(FeedbackSlotKind slot_kind)
     : ProcessedFeedback(kGlobalAccess, slot_kind),
-      cell_or_context_(base::nullopt),
       index_and_immutable_(0 /* doesn't matter */) {
   DCHECK(IsGlobalICKind(slot_kind));
 }
diff --git a/deps/v8/src/compiler/js-heap-broker.h b/deps/v8/src/compiler/js-heap-broker.h
index 0cd5df2944..424da1df55 100644
--- a/deps/v8/src/compiler/js-heap-broker.h
+++ b/deps/v8/src/compiler/js-heap-broker.h
@@ -228,7 +228,6 @@ class V8_EXPORT_PRIVATE JSHeapBroker {
       FeedbackSource const& source);
 
   void CollectArrayAndObjectPrototypes();
-  void SerializeTypedArrayStringTags();
 
   PerIsolateCompilerCache* compiler_cache() const { return compiler_cache_; }
 
diff --git a/deps/v8/src/compiler/js-heap-copy-reducer.cc b/deps/v8/src/compiler/js-heap-copy-reducer.cc
index 13bd6a1282..820928ec8c 100644
--- a/deps/v8/src/compiler/js-heap-copy-reducer.cc
+++ b/deps/v8/src/compiler/js-heap-copy-reducer.cc
@@ -27,6 +27,12 @@ JSHeapBroker* JSHeapCopyReducer::broker() { return broker_; }
 
 Reduction JSHeapCopyReducer::Reduce(Node* node) {
   switch (node->opcode()) {
+    case IrOpcode::kCheckClosure: {
+      FeedbackCellRef cell(broker(), FeedbackCellOf(node->op()));
+      FeedbackVectorRef feedback_vector = cell.value().AsFeedbackVector();
+      feedback_vector.Serialize();
+      break;
+    }
     case IrOpcode::kHeapConstant: {
       ObjectRef object(broker(), HeapConstantOf(node->op()));
       if (object.IsJSFunction()) object.AsJSFunction().Serialize();
diff --git a/deps/v8/src/compiler/js-inlining-heuristic.cc b/deps/v8/src/compiler/js-inlining-heuristic.cc
index 89233d3fea..f38cb51c1f 100644
--- a/deps/v8/src/compiler/js-inlining-heuristic.cc
+++ b/deps/v8/src/compiler/js-inlining-heuristic.cc
@@ -108,6 +108,20 @@ JSInliningHeuristic::Candidate JSInliningHeuristic::CollectFunctions(
     out.num_functions = value_input_count;
     return out;
   }
+  if (m.IsCheckClosure()) {
+    DCHECK(!out.functions[0].has_value());
+    FeedbackCellRef feedback_cell(broker(), FeedbackCellOf(m.op()));
+    SharedFunctionInfoRef shared_info =
+        feedback_cell.shared_function_info().value();
+    out.shared_info = shared_info;
+    if (feedback_cell.value().IsFeedbackVector() &&
+        CanConsiderForInlining(broker(), shared_info,
+                               feedback_cell.value().AsFeedbackVector())) {
+      out.bytecode[0] = shared_info.GetBytecodeArray();
+    }
+    out.num_functions = 1;
+    return out;
+  }
   if (m.IsJSCreateClosure()) {
     DCHECK(!out.functions[0].has_value());
     CreateClosureParameters const& p = CreateClosureParametersOf(m.op());
diff --git a/deps/v8/src/compiler/js-inlining.cc b/deps/v8/src/compiler/js-inlining.cc
index 60c7626067..16a6fb2f0f 100644
--- a/deps/v8/src/compiler/js-inlining.cc
+++ b/deps/v8/src/compiler/js-inlining.cc
@@ -8,6 +8,7 @@
 #include "src/codegen/compiler.h"
 #include "src/codegen/optimized-compilation-info.h"
 #include "src/codegen/tick-counter.h"
+#include "src/compiler/access-builder.h"
 #include "src/compiler/all-nodes.h"
 #include "src/compiler/bytecode-graph-builder.h"
 #include "src/compiler/common-operator.h"
@@ -317,13 +318,11 @@ base::Optional<SharedFunctionInfoRef> JSInliner::DetermineCallTarget(
   //  - JSConstruct(JSCreateClosure[shared](context), args..., new.target)
   if (match.IsJSCreateClosure()) {
     CreateClosureParameters const& p = CreateClosureParametersOf(match.op());
-
-    // TODO(turbofan): We might consider to eagerly create the feedback vector
-    // in such a case (in {DetermineCallContext} below) eventually.
     FeedbackCellRef cell(broker(), p.feedback_cell());
-    if (!cell.value().IsFeedbackVector()) return base::nullopt;
-
-    return SharedFunctionInfoRef(broker(), p.shared_info());
+    return cell.shared_function_info();
+  } else if (match.IsCheckClosure()) {
+    FeedbackCellRef cell(broker(), FeedbackCellOf(match.op()));
+    return cell.shared_function_info();
   }
 
   return base::nullopt;
@@ -354,11 +353,22 @@ FeedbackVectorRef JSInliner::DetermineCallContext(Node* node,
 
     // Load the feedback vector of the target by looking up its vector cell at
     // the instantiation site (we only decide to inline if it's populated).
-    FeedbackCellRef cell(FeedbackCellRef(broker(), p.feedback_cell()));
+    FeedbackCellRef cell(broker(), p.feedback_cell());
 
     // The inlinee uses the locally provided context at instantiation.
     *context_out = NodeProperties::GetContextInput(match.node());
     return cell.value().AsFeedbackVector();
+  } else if (match.IsCheckClosure()) {
+    FeedbackCellRef cell(broker(), FeedbackCellOf(match.op()));
+
+    Node* effect = NodeProperties::GetEffectInput(node);
+    Node* control = NodeProperties::GetControlInput(node);
+    *context_out = effect = graph()->NewNode(
+        simplified()->LoadField(AccessBuilder::ForJSFunctionContext()),
+        match.node(), effect, control);
+    NodeProperties::ReplaceEffectInput(node, effect);
+
+    return cell.value().AsFeedbackVector();
   }
 
   // Must succeed.
diff --git a/deps/v8/src/compiler/js-native-context-specialization.cc b/deps/v8/src/compiler/js-native-context-specialization.cc
index 3d730a07ef..3963edcbbd 100644
--- a/deps/v8/src/compiler/js-native-context-specialization.cc
+++ b/deps/v8/src/compiler/js-native-context-specialization.cc
@@ -1375,6 +1375,7 @@ Reduction JSNativeContextSpecialization::ReduceJSGetIterator(Node* node) {
       javascript()->LoadNamed(iterator_symbol, p.loadFeedback());
 
   // Lazy deopt of the load iterator property
+  // TODO(v8:10047): Use TaggedIndexConstant here once deoptimizer supports it.
   Node* call_slot = jsgraph()->SmiConstant(p.callFeedback().slot.ToInt());
   Node* call_feedback = jsgraph()->HeapConstant(p.callFeedback().vector);
   Node* lazy_deopt_parameters[] = {receiver, call_slot, call_feedback};
@@ -2635,6 +2636,15 @@ JSNativeContextSpecialization::BuildElementAccess(
           Node* etrue = effect;
           Node* vtrue;
           {
+            // Do a real bounds check against {length}. This is in order to
+            // protect against a potential typer bug leading to the elimination
+            // of the NumberLessThan above.
+            index = etrue = graph()->NewNode(
+                simplified()->CheckBounds(
+                    FeedbackSource(),
+                    CheckBoundsParameters::kAbortOnOutOfBounds),
+                index, length, etrue, if_true);
+
             // Perform the actual load
             vtrue = etrue = graph()->NewNode(
                 simplified()->LoadTypedElement(external_array_type),
@@ -2696,6 +2706,15 @@ JSNativeContextSpecialization::BuildElementAccess(
           Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
           Node* etrue = effect;
           {
+            // Do a real bounds check against {length}. This is in order to
+            // protect against a potential typer bug leading to the elimination
+            // of the NumberLessThan above.
+            index = etrue = graph()->NewNode(
+                simplified()->CheckBounds(
+                    FeedbackSource(),
+                    CheckBoundsParameters::kAbortOnOutOfBounds),
+                index, length, etrue, if_true);
+
             // Perform the actual store.
             etrue = graph()->NewNode(
                 simplified()->StoreTypedElement(external_array_type),
@@ -2828,6 +2847,14 @@ JSNativeContextSpecialization::BuildElementAccess(
         Node* etrue = effect;
         Node* vtrue;
         {
+          // Do a real bounds check against {length}. This is in order to
+          // protect against a potential typer bug leading to the elimination of
+          // the NumberLessThan above.
+          index = etrue = graph()->NewNode(
+              simplified()->CheckBounds(
+                  FeedbackSource(), CheckBoundsParameters::kAbortOnOutOfBounds),
+              index, length, etrue, if_true);
+
           // Perform the actual load
           vtrue = etrue =
               graph()->NewNode(simplified()->LoadElement(element_access),
@@ -3096,13 +3123,18 @@ Node* JSNativeContextSpecialization::BuildIndexedStringLoad(
                                           IsSafetyCheck::kCriticalSafetyCheck),
                          check, *control);
 
-    Node* masked_index = graph()->NewNode(simplified()->PoisonIndex(), index);
-
     Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-    Node* etrue;
+    // Do a real bounds check against {length}. This is in order to protect
+    // against a potential typer bug leading to the elimination of the
+    // NumberLessThan above.
+    Node* etrue = index = graph()->NewNode(
+        simplified()->CheckBounds(FeedbackSource(),
+                                  CheckBoundsParameters::kAbortOnOutOfBounds),
+        index, length, *effect, if_true);
+    Node* masked_index = graph()->NewNode(simplified()->PoisonIndex(), index);
     Node* vtrue = etrue =
         graph()->NewNode(simplified()->StringCharCodeAt(), receiver,
-                         masked_index, *effect, if_true);
+                         masked_index, etrue, if_true);
     vtrue = graph()->NewNode(simplified()->StringFromSingleCharCode(), vtrue);
 
     Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
diff --git a/deps/v8/src/compiler/js-typed-lowering.cc b/deps/v8/src/compiler/js-typed-lowering.cc
index c5ebc2f6a1..47f931317e 100644
--- a/deps/v8/src/compiler/js-typed-lowering.cc
+++ b/deps/v8/src/compiler/js-typed-lowering.cc
@@ -428,8 +428,8 @@ JSTypedLowering::JSTypedLowering(Editor* editor, JSGraph* jsgraph,
     : AdvancedReducer(editor),
       jsgraph_(jsgraph),
       broker_(broker),
-      empty_string_type_(Type::HeapConstant(broker, factory()->empty_string(),
-                                            graph()->zone())),
+      empty_string_type_(
+          Type::Constant(broker, factory()->empty_string(), graph()->zone())),
       pointer_comparable_type_(
           Type::Union(Type::Oddball(),
                       Type::Union(Type::SymbolOrReceiver(), empty_string_type_,
@@ -848,24 +848,19 @@ Reduction JSTypedLowering::ReduceJSEqual(Node* node) {
 
 Reduction JSTypedLowering::ReduceJSStrictEqual(Node* node) {
   JSBinopReduction r(this, node);
+  if (r.type().IsSingleton()) {
+    // Let ConstantFoldingReducer handle this.
+    return NoChange();
+  }
   if (r.left() == r.right()) {
     // x === x is always true if x != NaN
     Node* replacement = graph()->NewNode(
         simplified()->BooleanNot(),
         graph()->NewNode(simplified()->ObjectIsNaN(), r.left()));
+    DCHECK(NodeProperties::GetType(replacement).Is(r.type()));
     ReplaceWithValue(node, replacement);
     return Replace(replacement);
   }
-  if (r.OneInputCannotBe(Type::NumericOrString())) {
-    // For values with canonical representation (i.e. neither String nor
-    // Numeric) an empty type intersection means the values cannot be strictly
-    // equal.
-    if (!r.left_type().Maybe(r.right_type())) {
-      Node* replacement = jsgraph()->FalseConstant();
-      ReplaceWithValue(node, replacement);
-      return Replace(replacement);
-    }
-  }
 
   if (r.BothInputsAre(Type::Unique())) {
     return r.ChangeToPureOperator(simplified()->ReferenceEqual());
@@ -1530,7 +1525,7 @@ void ReduceBuiltin(JSGraph* jsgraph, Node* node, int builtin_index, int arity,
 }
 
 bool NeedsArgumentAdaptorFrame(SharedFunctionInfoRef shared, int arity) {
-  static const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
+  static const int sentinel = kDontAdaptArgumentsSentinel;
   const int num_decl_parms = shared.internal_formal_parameter_count();
   return (num_decl_parms != arity && num_decl_parms != sentinel);
 }
@@ -1664,34 +1659,46 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
     convert_mode = ConvertReceiverMode::kNotNullOrUndefined;
   }
 
-  // Check if {target} is a known JSFunction.
+  // Check if we know the SharedFunctionInfo of {target}.
+  base::Optional<JSFunctionRef> function;
+  base::Optional<SharedFunctionInfoRef> shared;
+
   if (target_type.IsHeapConstant() &&
       target_type.AsHeapConstant()->Ref().IsJSFunction()) {
-    JSFunctionRef function = target_type.AsHeapConstant()->Ref().AsJSFunction();
+    function = target_type.AsHeapConstant()->Ref().AsJSFunction();
 
-    if (!function.serialized()) {
-      TRACE_BROKER_MISSING(broker(), "data for function " << function);
+    if (!function->serialized()) {
+      TRACE_BROKER_MISSING(broker(), "data for function " << *function);
       return NoChange();
     }
-    SharedFunctionInfoRef shared = function.shared();
+    shared = function->shared();
+  } else if (target->opcode() == IrOpcode::kJSCreateClosure) {
+    CreateClosureParameters const& ccp =
+        CreateClosureParametersOf(target->op());
+    shared = SharedFunctionInfoRef(broker(), ccp.shared_info());
+  } else if (target->opcode() == IrOpcode::kCheckClosure) {
+    FeedbackCellRef cell(broker(), FeedbackCellOf(target->op()));
+    shared = cell.value().AsFeedbackVector().shared_function_info();
+  }
 
+  if (shared.has_value()) {
     // Do not inline the call if we need to check whether to break at entry.
-    if (shared.HasBreakInfo()) return NoChange();
+    if (shared->HasBreakInfo()) return NoChange();
 
     // Class constructors are callable, but [[Call]] will raise an exception.
     // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList ).
-    if (IsClassConstructor(shared.kind())) return NoChange();
+    if (IsClassConstructor(shared->kind())) return NoChange();
 
     // Check if we need to convert the {receiver}, but bailout if it would
     // require data from a foreign native context.
-    if (is_sloppy(shared.language_mode()) && !shared.native() &&
+    if (is_sloppy(shared->language_mode()) && !shared->native() &&
         !receiver_type.Is(Type::Receiver())) {
-      if (!function.native_context().equals(
-              broker()->target_native_context())) {
+      if (!function.has_value() || !function->native_context().equals(
+                                       broker()->target_native_context())) {
         return NoChange();
       }
       Node* global_proxy =
-          jsgraph()->Constant(function.native_context().global_proxy_object());
+          jsgraph()->Constant(function->native_context().global_proxy_object());
       receiver = effect =
           graph()->NewNode(simplified()->ConvertReceiver(convert_mode),
                            receiver, global_proxy, effect, control);
@@ -1711,20 +1718,20 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
     CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
     Node* new_target = jsgraph()->UndefinedConstant();
 
-    if (NeedsArgumentAdaptorFrame(shared, arity)) {
+    if (NeedsArgumentAdaptorFrame(*shared, arity)) {
       // Check if it's safe to skip the arguments adaptor for {shared},
       // that is whether the target function anyways cannot observe the
       // actual arguments. Details can be found in this document at
       // https://bit.ly/v8-faster-calls-with-arguments-mismatch and
       // on the tracking bug at https://crbug.com/v8/8895
-      if (shared.is_safe_to_skip_arguments_adaptor()) {
+      if (shared->is_safe_to_skip_arguments_adaptor()) {
         // Currently we only support skipping arguments adaptor frames
         // for strict mode functions, since there's Function.arguments
         // legacy accessor, which is still available in sloppy mode.
-        DCHECK_EQ(LanguageMode::kStrict, shared.language_mode());
+        DCHECK_EQ(LanguageMode::kStrict, shared->language_mode());
 
         // Massage the arguments to match the expected number of arguments.
-        int expected_argument_count = shared.internal_formal_parameter_count();
+        int expected_argument_count = shared->internal_formal_parameter_count();
         for (; arity > expected_argument_count; --arity) {
           node->RemoveInput(arity + 1);
         }
@@ -1750,20 +1757,21 @@ Reduction JSTypedLowering::ReduceJSCall(Node* node) {
         node->InsertInput(graph()->zone(), 3, jsgraph()->Constant(arity));
         node->InsertInput(
             graph()->zone(), 4,
-            jsgraph()->Constant(shared.internal_formal_parameter_count()));
+            jsgraph()->Constant(shared->internal_formal_parameter_count()));
         NodeProperties::ChangeOp(
             node,
             common()->Call(Linkage::GetStubCallDescriptor(
                 graph()->zone(), callable.descriptor(), 1 + arity, flags)));
       }
-    } else if (shared.HasBuiltinId() && Builtins::IsCpp(shared.builtin_id())) {
+    } else if (shared->HasBuiltinId() &&
+               Builtins::IsCpp(shared->builtin_id())) {
       // Patch {node} to a direct CEntry call.
-      ReduceBuiltin(jsgraph(), node, shared.builtin_id(), arity, flags);
-    } else if (shared.HasBuiltinId()) {
-      DCHECK(Builtins::HasJSLinkage(shared.builtin_id()));
+      ReduceBuiltin(jsgraph(), node, shared->builtin_id(), arity, flags);
+    } else if (shared->HasBuiltinId()) {
+      DCHECK(Builtins::HasJSLinkage(shared->builtin_id()));
       // Patch {node} to a direct code object call.
       Callable callable = Builtins::CallableFor(
-          isolate(), static_cast<Builtins::Name>(shared.builtin_id()));
+          isolate(), static_cast<Builtins::Name>(shared->builtin_id()));
       CallDescriptor::Flags flags = CallDescriptor::kNeedsFrameState;
 
       const CallInterfaceDescriptor& descriptor = callable.descriptor();
diff --git a/deps/v8/src/compiler/linkage.cc b/deps/v8/src/compiler/linkage.cc
index 39c93c0328..e97ee820f3 100644
--- a/deps/v8/src/compiler/linkage.cc
+++ b/deps/v8/src/compiler/linkage.cc
@@ -401,7 +401,9 @@ CallDescriptor* Linkage::GetStubCallDescriptor(
       // The rest of the parameters go on the stack.
       int stack_slot = i - register_parameter_count - stack_parameter_count;
       locations.AddParam(LinkageLocation::ForCallerFrameSlot(
-          stack_slot, MachineType::AnyTagged()));
+          stack_slot, i < descriptor.GetParameterCount()
+                          ? descriptor.GetParameterType(i)
+                          : MachineType::AnyTagged()));
     }
   }
   // Add context.
diff --git a/deps/v8/src/compiler/linkage.h b/deps/v8/src/compiler/linkage.h
index 17a419bab3..b55f3cdcb7 100644
--- a/deps/v8/src/compiler/linkage.h
+++ b/deps/v8/src/compiler/linkage.h
@@ -18,7 +18,16 @@
 #include "src/runtime/runtime.h"
 #include "src/zone/zone.h"
 
+#if !defined(__clang__) && defined(_M_ARM64)
+// _M_ARM64 is an MSVC-specific macro that clang-cl emulates.
+#define NO_INLINE_FOR_ARM64_MSVC __declspec(noinline)
+#else
+#define NO_INLINE_FOR_ARM64_MSVC
+#endif
+
 namespace v8 {
+class CFunctionInfo;
+
 namespace internal {
 
 class CallInterfaceDescriptor;
@@ -134,7 +143,9 @@ class LinkageLocation {
            LocationField::kShift;
   }
 
-  bool IsRegister() const { return TypeField::decode(bit_field_) == REGISTER; }
+  NO_INLINE_FOR_ARM64_MSVC bool IsRegister() const {
+    return TypeField::decode(bit_field_) == REGISTER;
+  }
   bool IsAnyRegister() const {
     return IsRegister() && GetLocation() == ANY_REGISTER;
   }
@@ -357,6 +368,13 @@ class V8_EXPORT_PRIVATE CallDescriptor final
     return allocatable_registers_ != 0;
   }
 
+  // Stores the signature information for a fast API call - C++ functions
+  // that can be called directly from TurboFan.
+  void SetCFunctionInfo(const CFunctionInfo* c_function_info) {
+    c_function_info_ = c_function_info;
+  }
+  const CFunctionInfo* GetCFunctionInfo() const { return c_function_info_; }
+
  private:
   friend class Linkage;
 
@@ -374,6 +392,7 @@ class V8_EXPORT_PRIVATE CallDescriptor final
   const RegList allocatable_registers_;
   const Flags flags_;
   const char* const debug_name_;
+  const CFunctionInfo* c_function_info_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(CallDescriptor);
 };
@@ -505,5 +524,6 @@ class V8_EXPORT_PRIVATE Linkage : public NON_EXPORTED_BASE(ZoneObject) {
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
+#undef NO_INLINE_FOR_ARM64_MSVC
 
 #endif  // V8_COMPILER_LINKAGE_H_
diff --git a/deps/v8/src/compiler/machine-graph.cc b/deps/v8/src/compiler/machine-graph.cc
index 3f05d56a9a..0a00392f4b 100644
--- a/deps/v8/src/compiler/machine-graph.cc
+++ b/deps/v8/src/compiler/machine-graph.cc
@@ -32,6 +32,15 @@ Node* MachineGraph::IntPtrConstant(intptr_t value) {
                            : Int64Constant(static_cast<int64_t>(value));
 }
 
+Node* MachineGraph::TaggedIndexConstant(intptr_t value) {
+  int32_t value32 = static_cast<int32_t>(value);
+  Node** loc = cache_.FindTaggedIndexConstant(value32);
+  if (*loc == nullptr) {
+    *loc = graph()->NewNode(common()->TaggedIndexConstant(value32));
+  }
+  return *loc;
+}
+
 Node* MachineGraph::RelocatableInt32Constant(int32_t value,
                                              RelocInfo::Mode rmode) {
   Node** loc = cache_.FindRelocatableInt32Constant(
diff --git a/deps/v8/src/compiler/machine-graph.h b/deps/v8/src/compiler/machine-graph.h
index 86c3847211..9eb5998dfc 100644
--- a/deps/v8/src/compiler/machine-graph.h
+++ b/deps/v8/src/compiler/machine-graph.h
@@ -44,6 +44,8 @@ class V8_EXPORT_PRIVATE MachineGraph : public NON_EXPORTED_BASE(ZoneObject) {
   // constants is probably not serializable.
   Node* IntPtrConstant(intptr_t value);
 
+  Node* TaggedIndexConstant(intptr_t value);
+
   Node* RelocatableInt32Constant(int32_t value, RelocInfo::Mode rmode);
   Node* RelocatableInt64Constant(int64_t value, RelocInfo::Mode rmode);
   Node* RelocatableIntPtrConstant(intptr_t value, RelocInfo::Mode rmode);
diff --git a/deps/v8/src/compiler/machine-operator-reducer.cc b/deps/v8/src/compiler/machine-operator-reducer.cc
index 4a192cd3e1..9527074825 100644
--- a/deps/v8/src/compiler/machine-operator-reducer.cc
+++ b/deps/v8/src/compiler/machine-operator-reducer.cc
@@ -297,6 +297,27 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       }
       // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
       if (m.LeftEqualsRight()) return ReplaceBool(true);  // x == x => true
+      if (m.left().IsWord32And() && m.right().HasValue()) {
+        Uint32BinopMatcher mand(m.left().node());
+        if ((mand.left().IsWord32Shr() || mand.left().IsWord32Sar()) &&
+            mand.right().HasValue()) {
+          Uint32BinopMatcher mshift(mand.left().node());
+          // ((x >> K1) & K2) == K3 => (x & (K2 << K1)) == (K3 << K1)
+          if (mshift.right().HasValue()) {
+            auto shift_bits = mshift.right().Value();
+            auto mask = mand.right().Value();
+            auto rhs = static_cast<uint32_t>(m.right().Value());
+            // Make sure that we won't shift data off the end.
+            if (shift_bits <= base::bits::CountLeadingZeros(mask) &&
+                shift_bits <= base::bits::CountLeadingZeros(rhs)) {
+              node->ReplaceInput(
+                  0, Word32And(mshift.left().node(), mask << shift_bits));
+              node->ReplaceInput(1, Int32Constant(rhs << shift_bits));
+              return Changed(node);
+            }
+          }
+        }
+      }
       break;
     }
     case IrOpcode::kWord64Equal: {
@@ -832,6 +853,12 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
+    case IrOpcode::kBranch:
+    case IrOpcode::kDeoptimizeIf:
+    case IrOpcode::kDeoptimizeUnless:
+    case IrOpcode::kTrapIf:
+    case IrOpcode::kTrapUnless:
+      return ReduceConditional(node);
     default:
       break;
   }
@@ -1659,6 +1686,37 @@ Reduction MachineOperatorReducer::ReduceFloat64RoundDown(Node* node) {
   return NoChange();
 }
 
+Reduction MachineOperatorReducer::ReduceConditional(Node* node) {
+  DCHECK(node->opcode() == IrOpcode::kBranch ||
+         node->opcode() == IrOpcode::kDeoptimizeIf ||
+         node->opcode() == IrOpcode::kDeoptimizeUnless ||
+         node->opcode() == IrOpcode::kTrapIf ||
+         node->opcode() == IrOpcode::kTrapUnless);
+  // This reducer only applies operator reductions to the branch condition.
+  // Reductions involving control flow happen elsewhere. Non-zero inputs are
+  // considered true in all conditional ops.
+  NodeMatcher condition(NodeProperties::GetValueInput(node, 0));
+  if (condition.IsWord32And()) {
+    Uint32BinopMatcher mand(condition.node());
+    if ((mand.left().IsWord32Shr() || mand.left().IsWord32Sar()) &&
+        mand.right().HasValue()) {
+      Uint32BinopMatcher mshift(mand.left().node());
+      // Branch condition (x >> K1) & K2 => x & (K2 << K1)
+      if (mshift.right().HasValue()) {
+        auto shift_bits = mshift.right().Value();
+        auto mask = mand.right().Value();
+        // Make sure that we won't shift data off the end.
+        if (shift_bits <= base::bits::CountLeadingZeros(mask)) {
+          NodeProperties::ReplaceValueInput(
+              node, Word32And(mshift.left().node(), mask << shift_bits), 0);
+          return Changed(node);
+        }
+      }
+    }
+  }
+  return NoChange();
+}
+
 CommonOperatorBuilder* MachineOperatorReducer::common() const {
   return mcgraph()->common();
 }
diff --git a/deps/v8/src/compiler/machine-operator-reducer.h b/deps/v8/src/compiler/machine-operator-reducer.h
index 2e869c9062..53c5d6fa68 100644
--- a/deps/v8/src/compiler/machine-operator-reducer.h
+++ b/deps/v8/src/compiler/machine-operator-reducer.h
@@ -109,6 +109,7 @@ class V8_EXPORT_PRIVATE MachineOperatorReducer final
   Reduction ReduceFloat64InsertHighWord32(Node* node);
   Reduction ReduceFloat64Compare(Node* node);
   Reduction ReduceFloat64RoundDown(Node* node);
+  Reduction ReduceConditional(Node* node);
 
   Graph* graph() const;
   MachineGraph* mcgraph() const { return mcgraph_; }
diff --git a/deps/v8/src/compiler/machine-operator.cc b/deps/v8/src/compiler/machine-operator.cc
index aadf48c5b9..898182db31 100644
--- a/deps/v8/src/compiler/machine-operator.cc
+++ b/deps/v8/src/compiler/machine-operator.cc
@@ -389,6 +389,8 @@ MachineType AtomicOpType(Operator const* op) {
   V(I32x4MaxU, Operator::kCommutative, 2, 0, 1)                            \
   V(I32x4GtU, Operator::kNoProperties, 2, 0, 1)                            \
   V(I32x4GeU, Operator::kNoProperties, 2, 0, 1)                            \
+  V(I32x4Abs, Operator::kNoProperties, 1, 0, 1)                            \
+  V(I32x4BitMask, Operator::kNoProperties, 1, 0, 1)                        \
   V(I16x8Splat, Operator::kNoProperties, 1, 0, 1)                          \
   V(I16x8SConvertI8x16Low, Operator::kNoProperties, 1, 0, 1)               \
   V(I16x8SConvertI8x16High, Operator::kNoProperties, 1, 0, 1)              \
@@ -419,6 +421,8 @@ MachineType AtomicOpType(Operator const* op) {
   V(I16x8GtU, Operator::kNoProperties, 2, 0, 1)                            \
   V(I16x8GeU, Operator::kNoProperties, 2, 0, 1)                            \
   V(I16x8RoundingAverageU, Operator::kCommutative, 2, 0, 1)                \
+  V(I16x8Abs, Operator::kNoProperties, 1, 0, 1)                            \
+  V(I16x8BitMask, Operator::kNoProperties, 1, 0, 1)                        \
   V(I8x16Splat, Operator::kNoProperties, 1, 0, 1)                          \
   V(I8x16Neg, Operator::kNoProperties, 1, 0, 1)                            \
   V(I8x16Shl, Operator::kNoProperties, 2, 0, 1)                            \
@@ -444,6 +448,8 @@ MachineType AtomicOpType(Operator const* op) {
   V(I8x16GtU, Operator::kNoProperties, 2, 0, 1)                            \
   V(I8x16GeU, Operator::kNoProperties, 2, 0, 1)                            \
   V(I8x16RoundingAverageU, Operator::kCommutative, 2, 0, 1)                \
+  V(I8x16Abs, Operator::kNoProperties, 1, 0, 1)                            \
+  V(I8x16BitMask, Operator::kNoProperties, 1, 0, 1)                        \
   V(S128Load, Operator::kNoProperties, 2, 0, 1)                            \
   V(S128Store, Operator::kNoProperties, 3, 0, 1)                           \
   V(S128Zero, Operator::kNoProperties, 0, 0, 1)                            \
@@ -614,56 +620,52 @@ struct MachineOperatorGlobalCache {
   OVERFLOW_OP_LIST(OVERFLOW_OP)
 #undef OVERFLOW_OP
 
-#define LOAD(Type)                                                            \
-  struct Load##Type##Operator final : public Operator1<LoadRepresentation> {  \
-    Load##Type##Operator()                                                    \
-        : Operator1<LoadRepresentation>(                                      \
-              IrOpcode::kLoad,                                                \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,   \
-              "Load", 2, 1, 1, 1, 1, 0, MachineType::Type()) {}               \
-  };                                                                          \
-  struct PoisonedLoad##Type##Operator final                                   \
-      : public Operator1<LoadRepresentation> {                                \
-    PoisonedLoad##Type##Operator()                                            \
-        : Operator1<LoadRepresentation>(                                      \
-              IrOpcode::kPoisonedLoad,                                        \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,   \
-              "PoisonedLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {}       \
-  };                                                                          \
-  struct UnalignedLoad##Type##Operator final                                  \
-      : public Operator1<LoadRepresentation> {                                \
-    UnalignedLoad##Type##Operator()                                           \
-        : Operator1<LoadRepresentation>(                                      \
-              IrOpcode::kUnalignedLoad,                                       \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,   \
-              "UnalignedLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {}      \
-  };                                                                          \
-  struct ProtectedLoad##Type##Operator final                                  \
-      : public Operator1<LoadRepresentation> {                                \
-    ProtectedLoad##Type##Operator()                                           \
-        : Operator1<LoadRepresentation>(                                      \
-              IrOpcode::kProtectedLoad,                                       \
-              Operator::kNoDeopt | Operator::kNoThrow, "ProtectedLoad", 2, 1, \
-              1, 1, 1, 0, MachineType::Type()) {}                             \
-  };                                                                          \
-  Load##Type##Operator kLoad##Type;                                           \
-  PoisonedLoad##Type##Operator kPoisonedLoad##Type;                           \
-  UnalignedLoad##Type##Operator kUnalignedLoad##Type;                         \
+#define LOAD(Type)                                                             \
+  struct Load##Type##Operator final : public Operator1<LoadRepresentation> {   \
+    Load##Type##Operator()                                                     \
+        : Operator1<LoadRepresentation>(IrOpcode::kLoad,                       \
+                                        Operator::kEliminatable, "Load", 2, 1, \
+                                        1, 1, 1, 0, MachineType::Type()) {}    \
+  };                                                                           \
+  struct PoisonedLoad##Type##Operator final                                    \
+      : public Operator1<LoadRepresentation> {                                 \
+    PoisonedLoad##Type##Operator()                                             \
+        : Operator1<LoadRepresentation>(                                       \
+              IrOpcode::kPoisonedLoad, Operator::kEliminatable,                \
+              "PoisonedLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {}        \
+  };                                                                           \
+  struct UnalignedLoad##Type##Operator final                                   \
+      : public Operator1<LoadRepresentation> {                                 \
+    UnalignedLoad##Type##Operator()                                            \
+        : Operator1<LoadRepresentation>(                                       \
+              IrOpcode::kUnalignedLoad, Operator::kEliminatable,               \
+              "UnalignedLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {}       \
+  };                                                                           \
+  struct ProtectedLoad##Type##Operator final                                   \
+      : public Operator1<LoadRepresentation> {                                 \
+    ProtectedLoad##Type##Operator()                                            \
+        : Operator1<LoadRepresentation>(                                       \
+              IrOpcode::kProtectedLoad,                                        \
+              Operator::kNoDeopt | Operator::kNoThrow, "ProtectedLoad", 2, 1,  \
+              1, 1, 1, 0, MachineType::Type()) {}                              \
+  };                                                                           \
+  Load##Type##Operator kLoad##Type;                                            \
+  PoisonedLoad##Type##Operator kPoisonedLoad##Type;                            \
+  UnalignedLoad##Type##Operator kUnalignedLoad##Type;                          \
   ProtectedLoad##Type##Operator kProtectedLoad##Type;
   MACHINE_TYPE_LIST(LOAD)
 #undef LOAD
 
-#define LOAD_TRANSFORM_KIND(TYPE, KIND)                                     \
-  struct KIND##LoadTransform##TYPE##Operator final                          \
-      : public Operator1<LoadTransformParameters> {                         \
-    KIND##LoadTransform##TYPE##Operator()                                   \
-        : Operator1<LoadTransformParameters>(                               \
-              IrOpcode::kLoadTransform,                                     \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite, \
-              #KIND "LoadTransform", 2, 1, 1, 1, 1, 0,                      \
-              LoadTransformParameters{LoadKind::k##KIND,                    \
-                                      LoadTransformation::k##TYPE}) {}      \
-  };                                                                        \
+#define LOAD_TRANSFORM_KIND(TYPE, KIND)                                \
+  struct KIND##LoadTransform##TYPE##Operator final                     \
+      : public Operator1<LoadTransformParameters> {                    \
+    KIND##LoadTransform##TYPE##Operator()                              \
+        : Operator1<LoadTransformParameters>(                          \
+              IrOpcode::kLoadTransform, Operator::kEliminatable,       \
+              #KIND "LoadTransform", 2, 1, 1, 1, 1, 0,                 \
+              LoadTransformParameters{LoadKind::k##KIND,               \
+                                      LoadTransformation::k##TYPE}) {} \
+  };                                                                   \
   KIND##LoadTransform##TYPE##Operator k##KIND##LoadTransform##TYPE;
 
 #define LOAD_TRANSFORM(TYPE)           \
@@ -764,8 +766,7 @@ struct MachineOperatorGlobalCache {
       : public Operator1<LoadRepresentation> {                              \
     Word32AtomicLoad##Type##Operator()                                      \
         : Operator1<LoadRepresentation>(                                    \
-              IrOpcode::kWord32AtomicLoad,                                  \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite, \
+              IrOpcode::kWord32AtomicLoad, Operator::kEliminatable,         \
               "Word32AtomicLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {} \
   };                                                                        \
   Word32AtomicLoad##Type##Operator kWord32AtomicLoad##Type;
@@ -777,8 +778,7 @@ struct MachineOperatorGlobalCache {
       : public Operator1<LoadRepresentation> {                              \
     Word64AtomicLoad##Type##Operator()                                      \
         : Operator1<LoadRepresentation>(                                    \
-              IrOpcode::kWord64AtomicLoad,                                  \
-              Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite, \
+              IrOpcode::kWord64AtomicLoad, Operator::kEliminatable,         \
               "Word64AtomicLoad", 2, 1, 1, 1, 1, 0, MachineType::Type()) {} \
   };                                                                        \
   Word64AtomicLoad##Type##Operator kWord64AtomicLoad##Type;
diff --git a/deps/v8/src/compiler/machine-operator.h b/deps/v8/src/compiler/machine-operator.h
index d3792be559..d4f9ffa0fd 100644
--- a/deps/v8/src/compiler/machine-operator.h
+++ b/deps/v8/src/compiler/machine-operator.h
@@ -629,6 +629,8 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I32x4MaxU();
   const Operator* I32x4GtU();
   const Operator* I32x4GeU();
+  const Operator* I32x4Abs();
+  const Operator* I32x4BitMask();
 
   const Operator* I16x8Splat();
   const Operator* I16x8ExtractLaneU(int32_t);
@@ -664,6 +666,8 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I16x8GtU();
   const Operator* I16x8GeU();
   const Operator* I16x8RoundingAverageU();
+  const Operator* I16x8Abs();
+  const Operator* I16x8BitMask();
 
   const Operator* I8x16Splat();
   const Operator* I8x16ExtractLaneU(int32_t);
@@ -694,6 +698,8 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I8x16GtU();
   const Operator* I8x16GeU();
   const Operator* I8x16RoundingAverageU();
+  const Operator* I8x16Abs();
+  const Operator* I8x16BitMask();
 
   const Operator* S128Load();
   const Operator* S128Store();
diff --git a/deps/v8/src/compiler/node-cache.cc b/deps/v8/src/compiler/node-cache.cc
deleted file mode 100644
index 70e497ae60..0000000000
--- a/deps/v8/src/compiler/node-cache.cc
+++ /dev/null
@@ -1,125 +0,0 @@
-// Copyright 2014 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/compiler/node-cache.h"
-
-#include <cstring>
-
-#include "src/common/globals.h"
-#include "src/zone/zone-containers.h"
-#include "src/zone/zone.h"
-
-namespace v8 {
-namespace internal {
-namespace compiler {
-
-namespace {
-
-enum { kInitialSize = 16u, kLinearProbe = 5u };
-
-}  // namespace
-
-
-template <typename Key, typename Hash, typename Pred>
-struct NodeCache<Key, Hash, Pred>::Entry {
-  Key key_;
-  Node* value_;
-};
-
-
-template <typename Key, typename Hash, typename Pred>
-bool NodeCache<Key, Hash, Pred>::Resize(Zone* zone) {
-  if (size_ >= max_) return false;  // Don't grow past the maximum size.
-
-  // Allocate a new block of entries 4x the size.
-  Entry* old_entries = entries_;
-  size_t old_size = size_ + kLinearProbe;
-  size_ *= 4;
-  size_t num_entries = size_ + kLinearProbe;
-  entries_ = zone->NewArray<Entry>(num_entries);
-  memset(static_cast<void*>(entries_), 0, sizeof(Entry) * num_entries);
-
-  // Insert the old entries into the new block.
-  for (size_t i = 0; i < old_size; ++i) {
-    Entry* old = &old_entries[i];
-    if (old->value_) {
-      size_t hash = hash_(old->key_);
-      size_t start = hash & (size_ - 1);
-      size_t end = start + kLinearProbe;
-      for (size_t j = start; j < end; ++j) {
-        Entry* entry = &entries_[j];
-        if (!entry->value_) {
-          entry->key_ = old->key_;
-          entry->value_ = old->value_;
-          break;
-        }
-      }
-    }
-  }
-  return true;
-}
-
-
-template <typename Key, typename Hash, typename Pred>
-Node** NodeCache<Key, Hash, Pred>::Find(Zone* zone, Key key) {
-  size_t hash = hash_(key);
-  if (!entries_) {
-    // Allocate the initial entries and insert the first entry.
-    size_t num_entries = kInitialSize + kLinearProbe;
-    entries_ = zone->NewArray<Entry>(num_entries);
-    size_ = kInitialSize;
-    memset(static_cast<void*>(entries_), 0, sizeof(Entry) * num_entries);
-    Entry* entry = &entries_[hash & (kInitialSize - 1)];
-    entry->key_ = key;
-    return &entry->value_;
-  }
-
-  for (;;) {
-    // Search up to N entries after (linear probing).
-    size_t start = hash & (size_ - 1);
-    size_t end = start + kLinearProbe;
-    for (size_t i = start; i < end; i++) {
-      Entry* entry = &entries_[i];
-      if (pred_(entry->key_, key)) return &entry->value_;
-      if (!entry->value_) {
-        entry->key_ = key;
-        return &entry->value_;
-      }
-    }
-
-    if (!Resize(zone)) break;  // Don't grow past the maximum size.
-  }
-
-  // If resized to maximum and still didn't find space, overwrite an entry.
-  Entry* entry = &entries_[hash & (size_ - 1)];
-  entry->key_ = key;
-  entry->value_ = nullptr;
-  return &entry->value_;
-}
-
-
-template <typename Key, typename Hash, typename Pred>
-void NodeCache<Key, Hash, Pred>::GetCachedNodes(ZoneVector<Node*>* nodes) {
-  if (entries_) {
-    for (size_t i = 0; i < size_ + kLinearProbe; i++) {
-      if (entries_[i].value_) nodes->push_back(entries_[i].value_);
-    }
-  }
-}
-
-
-// -----------------------------------------------------------------------------
-// Instantiations
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) NodeCache<int32_t>;
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) NodeCache<int64_t>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) NodeCache<RelocInt32Key>;
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) NodeCache<RelocInt64Key>;
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/src/compiler/node-cache.h b/deps/v8/src/compiler/node-cache.h
index c99eeafad8..935e5778e3 100644
--- a/deps/v8/src/compiler/node-cache.h
+++ b/deps/v8/src/compiler/node-cache.h
@@ -8,6 +8,7 @@
 #include "src/base/export-template.h"
 #include "src/base/functional.h"
 #include "src/base/macros.h"
+#include "src/zone/zone-containers.h"
 
 namespace v8 {
 namespace internal {
@@ -30,33 +31,25 @@ template <typename Key, typename Hash = base::hash<Key>,
           typename Pred = std::equal_to<Key> >
 class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) NodeCache final {
  public:
-  explicit NodeCache(unsigned max = 256)
-      : entries_(nullptr), size_(0), max_(max) {}
+  explicit NodeCache(Zone* zone) : map_(zone) {}
   ~NodeCache() = default;
 
   // Search for node associated with {key} and return a pointer to a memory
   // location in this cache that stores an entry for the key. If the location
   // returned by this method contains a non-nullptr node, the caller can use
-  // that
-  // node. Otherwise it is the responsibility of the caller to fill the entry
-  // with a new node.
-  // Note that a previous cache entry may be overwritten if the cache becomes
-  // too full or encounters too many hash collisions.
-  Node** Find(Zone* zone, Key key);
+  // that node. Otherwise it is the responsibility of the caller to fill the
+  // entry with a new node.
+  Node** Find(Key key) { return &(map_[key]); }
 
   // Appends all nodes from this cache to {nodes}.
-  void GetCachedNodes(ZoneVector<Node*>* nodes);
+  void GetCachedNodes(ZoneVector<Node*>* nodes) {
+    for (const auto& entry : map_) {
+      if (entry.second) nodes->push_back(entry.second);
+    }
+  }
 
  private:
-  struct Entry;
-
-  Entry* entries_;  // lazily-allocated hash entries.
-  size_t size_;
-  size_t max_;
-  Hash hash_;
-  Pred pred_;
-
-  bool Resize(Zone* zone);
+  ZoneUnorderedMap<Key, Node*, Hash, Pred> map_;
 
   DISALLOW_COPY_AND_ASSIGN(NodeCache);
 };
@@ -78,17 +71,6 @@ using IntPtrNodeCache = Int32NodeCache;
 using IntPtrNodeCache = Int64NodeCache;
 #endif
 
-// Explicit instantiation declarations.
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) NodeCache<int32_t>;
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) NodeCache<int64_t>;
-
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) NodeCache<RelocInt32Key>;
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) NodeCache<RelocInt64Key>;
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/compiler/node-matchers.h b/deps/v8/src/compiler/node-matchers.h
index 82bc179519..8c4e5e76d5 100644
--- a/deps/v8/src/compiler/node-matchers.h
+++ b/deps/v8/src/compiler/node-matchers.h
@@ -53,8 +53,13 @@ template <typename T, IrOpcode::Value kOpcode>
 struct ValueMatcher : public NodeMatcher {
   using ValueType = T;
 
-  explicit ValueMatcher(Node* node)
-      : NodeMatcher(node), value_(), has_value_(opcode() == kOpcode) {
+  explicit ValueMatcher(Node* node) : NodeMatcher(node) {
+    static_assert(kOpcode != IrOpcode::kFoldConstant, "unsupported opcode");
+    if (node->opcode() == IrOpcode::kFoldConstant) {
+      node = node->InputAt(1);
+    }
+    DCHECK_NE(node->opcode(), IrOpcode::kFoldConstant);
+    has_value_ = opcode() == kOpcode;
     if (has_value_) {
       value_ = OpParameter<T>(node->op());
     }
@@ -110,6 +115,30 @@ inline ValueMatcher<uint64_t, IrOpcode::kInt64Constant>::ValueMatcher(
   }
 }
 
+template <>
+inline ValueMatcher<double, IrOpcode::kNumberConstant>::ValueMatcher(Node* node)
+    : NodeMatcher(node), value_(), has_value_(false) {
+  if (node->opcode() == IrOpcode::kNumberConstant) {
+    value_ = OpParameter<double>(node->op());
+    has_value_ = true;
+  } else if (node->opcode() == IrOpcode::kFoldConstant) {
+    node = node->InputAt(1);
+    DCHECK_NE(node->opcode(), IrOpcode::kFoldConstant);
+  }
+}
+
+template <>
+inline ValueMatcher<Handle<HeapObject>, IrOpcode::kHeapConstant>::ValueMatcher(
+    Node* node)
+    : NodeMatcher(node), value_(), has_value_(false) {
+  if (node->opcode() == IrOpcode::kHeapConstant) {
+    value_ = OpParameter<Handle<HeapObject>>(node->op());
+    has_value_ = true;
+  } else if (node->opcode() == IrOpcode::kFoldConstant) {
+    node = node->InputAt(1);
+    DCHECK_NE(node->opcode(), IrOpcode::kFoldConstant);
+  }
+}
 
 // A pattern matcher for integer constants.
 template <typename T, IrOpcode::Value kOpcode>
diff --git a/deps/v8/src/compiler/opcodes.h b/deps/v8/src/compiler/opcodes.h
index 7836c4425d..61af28841a 100644
--- a/deps/v8/src/compiler/opcodes.h
+++ b/deps/v8/src/compiler/opcodes.h
@@ -30,8 +30,6 @@
   V(Return)                \
   V(TailCall)              \
   V(Terminate)             \
-  V(OsrNormalEntry)        \
-  V(OsrLoopEntry)          \
   V(Throw)                 \
   V(End)
 
@@ -39,6 +37,7 @@
 #define CONSTANT_OP_LIST(V)   \
   V(Int32Constant)            \
   V(Int64Constant)            \
+  V(TaggedIndexConstant)      \
   V(Float32Constant)          \
   V(Float64Constant)          \
   V(ExternalConstant)         \
@@ -49,31 +48,32 @@
   V(RelocatableInt32Constant) \
   V(RelocatableInt64Constant)
 
-#define INNER_OP_LIST(V)          \
-  V(Select)                       \
-  V(Phi)                          \
-  V(EffectPhi)                    \
-  V(InductionVariablePhi)         \
-  V(Checkpoint)                   \
-  V(BeginRegion)                  \
-  V(FinishRegion)                 \
-  V(FrameState)                   \
-  V(StateValues)                  \
-  V(TypedStateValues)             \
-  V(ArgumentsElementsState)       \
-  V(ArgumentsLengthState)         \
-  V(ObjectState)                  \
-  V(ObjectId)                     \
-  V(TypedObjectState)             \
-  V(Call)                         \
-  V(Parameter)                    \
-  V(OsrValue)                     \
-  V(LoopExit)                     \
-  V(LoopExitValue)                \
-  V(LoopExitEffect)               \
-  V(Projection)                   \
-  V(Retain)                       \
-  V(MapGuard)                     \
+#define INNER_OP_LIST(V)    \
+  V(Select)                 \
+  V(Phi)                    \
+  V(EffectPhi)              \
+  V(InductionVariablePhi)   \
+  V(Checkpoint)             \
+  V(BeginRegion)            \
+  V(FinishRegion)           \
+  V(FrameState)             \
+  V(StateValues)            \
+  V(TypedStateValues)       \
+  V(ArgumentsElementsState) \
+  V(ArgumentsLengthState)   \
+  V(ObjectState)            \
+  V(ObjectId)               \
+  V(TypedObjectState)       \
+  V(Call)                   \
+  V(Parameter)              \
+  V(OsrValue)               \
+  V(LoopExit)               \
+  V(LoopExitValue)          \
+  V(LoopExitEffect)         \
+  V(Projection)             \
+  V(Retain)                 \
+  V(MapGuard)               \
+  V(FoldConstant)           \
   V(TypeGuard)
 
 #define COMMON_OP_LIST(V) \
@@ -409,6 +409,7 @@
   V(CheckSmi)                           \
   V(CheckHeapObject)                    \
   V(CheckFloat64Hole)                   \
+  V(CheckClosure)                       \
   V(CheckNotTaggedHole)                 \
   V(CheckEqualsInternalizedString)      \
   V(CheckEqualsSymbol)                  \
@@ -475,7 +476,8 @@
   V(PoisonIndex)                        \
   V(RuntimeAbort)                       \
   V(AssertType)                         \
-  V(DateNow)
+  V(DateNow)                            \
+  V(FastApiCall)
 
 #define SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(V) \
   V(SpeculativeBigIntAdd)                           \
@@ -837,6 +839,8 @@
   V(I32x4LeU)                   \
   V(I32x4GtU)                   \
   V(I32x4GeU)                   \
+  V(I32x4Abs)                   \
+  V(I32x4BitMask)               \
   V(I16x8Splat)                 \
   V(I16x8ExtractLaneU)          \
   V(I16x8ExtractLaneS)          \
@@ -874,6 +878,8 @@
   V(I16x8GtU)                   \
   V(I16x8GeU)                   \
   V(I16x8RoundingAverageU)      \
+  V(I16x8Abs)                   \
+  V(I16x8BitMask)               \
   V(I8x16Splat)                 \
   V(I8x16ExtractLaneU)          \
   V(I8x16ExtractLaneS)          \
@@ -906,6 +912,8 @@
   V(I8x16GtU)                   \
   V(I8x16GeU)                   \
   V(I8x16RoundingAverageU)      \
+  V(I8x16Abs)                   \
+  V(I8x16BitMask)               \
   V(S128Load)                   \
   V(S128Store)                  \
   V(S128Zero)                   \
diff --git a/deps/v8/src/compiler/operation-typer.cc b/deps/v8/src/compiler/operation-typer.cc
index 3745d10214..229c7864b2 100644
--- a/deps/v8/src/compiler/operation-typer.cc
+++ b/deps/v8/src/compiler/operation-typer.cc
@@ -20,21 +20,18 @@ namespace compiler {
 OperationTyper::OperationTyper(JSHeapBroker* broker, Zone* zone)
     : zone_(zone), cache_(TypeCache::Get()) {
   Factory* factory = broker->isolate()->factory();
-  infinity_ = Type::NewConstant(V8_INFINITY, zone);
-  minus_infinity_ = Type::NewConstant(-V8_INFINITY, zone);
+  infinity_ = Type::Constant(V8_INFINITY, zone);
+  minus_infinity_ = Type::Constant(-V8_INFINITY, zone);
   Type truncating_to_zero = Type::MinusZeroOrNaN();
   DCHECK(!truncating_to_zero.Maybe(Type::Integral32()));
 
   singleton_empty_string_ =
-      Type::HeapConstant(broker, factory->empty_string(), zone);
-  singleton_NaN_string_ =
-      Type::HeapConstant(broker, factory->NaN_string(), zone);
-  singleton_zero_string_ =
-      Type::HeapConstant(broker, factory->zero_string(), zone);
-  singleton_false_ = Type::HeapConstant(broker, factory->false_value(), zone);
-  singleton_true_ = Type::HeapConstant(broker, factory->true_value(), zone);
-  singleton_the_hole_ =
-      Type::HeapConstant(broker, factory->the_hole_value(), zone);
+      Type::Constant(broker, factory->empty_string(), zone);
+  singleton_NaN_string_ = Type::Constant(broker, factory->NaN_string(), zone);
+  singleton_zero_string_ = Type::Constant(broker, factory->zero_string(), zone);
+  singleton_false_ = Type::Constant(broker, factory->false_value(), zone);
+  singleton_true_ = Type::Constant(broker, factory->true_value(), zone);
+  singleton_the_hole_ = Type::Hole();
   signed32ish_ = Type::Union(Type::Signed32(), truncating_to_zero, zone);
   unsigned32ish_ = Type::Union(Type::Unsigned32(), truncating_to_zero, zone);
 
@@ -1043,24 +1040,26 @@ Type OperationTyper::NumberMax(Type lhs, Type rhs) {
   if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
     type = Type::Union(type, Type::NaN(), zone());
   }
-  lhs = Type::Intersect(lhs, Type::OrderedNumber(), zone());
-  DCHECK(!lhs.IsNone());
-  rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
-  DCHECK(!rhs.IsNone());
-  if (lhs.Is(cache_->kIntegerOrMinusZero) &&
-      rhs.Is(cache_->kIntegerOrMinusZero)) {
-    // TODO(turbofan): This could still be improved in ruling out -0 when
-    // one of the inputs' min is 0.
-    double max = std::max(lhs.Max(), rhs.Max());
-    double min = std::max(lhs.Min(), rhs.Min());
+  if (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero())) {
+    type = Type::Union(type, Type::MinusZero(), zone());
+  }
+
+  if (!lhs.Is(cache_->kIntegerOrMinusZeroOrNaN) ||
+      !rhs.Is(cache_->kIntegerOrMinusZeroOrNaN)) {
+    return Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
+  }
+
+  lhs = Type::Intersect(lhs, cache_->kInteger, zone());
+  rhs = Type::Intersect(rhs, cache_->kInteger, zone());
+
+  if (!lhs.IsNone() || !rhs.IsNone()) {
+    double min = std::max(lhs.IsNone() ? -V8_INFINITY : lhs.Min(),
+                          rhs.IsNone() ? -V8_INFINITY : rhs.Min());
+    double max = std::max(lhs.IsNone() ? -V8_INFINITY : lhs.Max(),
+                          rhs.IsNone() ? -V8_INFINITY : rhs.Max());
     type = Type::Union(type, Type::Range(min, max, zone()), zone());
-    if (min <= 0.0 && 0.0 <= max &&
-        (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero()))) {
-      type = Type::Union(type, Type::MinusZero(), zone());
-    }
-  } else {
-    type = Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
   }
+
   return type;
 }
 
@@ -1075,22 +1074,26 @@ Type OperationTyper::NumberMin(Type lhs, Type rhs) {
   if (lhs.Maybe(Type::NaN()) || rhs.Maybe(Type::NaN())) {
     type = Type::Union(type, Type::NaN(), zone());
   }
-  lhs = Type::Intersect(lhs, Type::OrderedNumber(), zone());
-  DCHECK(!lhs.IsNone());
-  rhs = Type::Intersect(rhs, Type::OrderedNumber(), zone());
-  DCHECK(!rhs.IsNone());
-  if (lhs.Is(cache_->kIntegerOrMinusZero) &&
-      rhs.Is(cache_->kIntegerOrMinusZero)) {
-    double max = std::min(lhs.Max(), rhs.Max());
-    double min = std::min(lhs.Min(), rhs.Min());
+  if (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero())) {
+    type = Type::Union(type, Type::MinusZero(), zone());
+  }
+
+  if (!lhs.Is(cache_->kIntegerOrMinusZeroOrNaN) ||
+      !rhs.Is(cache_->kIntegerOrMinusZeroOrNaN)) {
+    return Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
+  }
+
+  lhs = Type::Intersect(lhs, cache_->kInteger, zone());
+  rhs = Type::Intersect(rhs, cache_->kInteger, zone());
+
+  if (!lhs.IsNone() || !rhs.IsNone()) {
+    double min = std::min(lhs.IsNone() ? +V8_INFINITY : lhs.Min(),
+                          rhs.IsNone() ? +V8_INFINITY : rhs.Min());
+    double max = std::min(lhs.IsNone() ? +V8_INFINITY : lhs.Max(),
+                          rhs.IsNone() ? +V8_INFINITY : rhs.Max());
     type = Type::Union(type, Type::Range(min, max, zone()), zone());
-    if (min <= 0.0 && 0.0 <= max &&
-        (lhs.Maybe(Type::MinusZero()) || rhs.Maybe(Type::MinusZero()))) {
-      type = Type::Union(type, Type::MinusZero(), zone());
-    }
-  } else {
-    type = Type::Union(type, Type::Union(lhs, rhs, zone()), zone());
   }
+
   return type;
 }
 
@@ -1242,14 +1245,17 @@ Type OperationTyper::StrictEqual(Type lhs, Type rhs) {
       (lhs.Max() < rhs.Min() || lhs.Min() > rhs.Max())) {
     return singleton_false();
   }
-  if ((lhs.Is(Type::Hole()) || rhs.Is(Type::Hole())) && !lhs.Maybe(rhs)) {
-    return singleton_false();
-  }
-  if (lhs.IsHeapConstant() && rhs.Is(lhs)) {
+  if (lhs.IsSingleton() && rhs.Is(lhs)) {
     // Types are equal and are inhabited only by a single semantic value,
     // which is not nan due to the earlier check.
+    DCHECK(lhs.Is(rhs));
+    DCHECK(lhs.Is(Type::NonInternal()) || lhs.Is(Type::Hole()));
     return singleton_true();
   }
+  if ((lhs.Is(Type::Unique()) || rhs.Is(Type::Unique())) && !lhs.Maybe(rhs)) {
+    // One of the inputs has a canonical representation but types don't overlap.
+    return singleton_false();
+  }
   return Type::Boolean();
 }
 
diff --git a/deps/v8/src/compiler/operator.h b/deps/v8/src/compiler/operator.h
index c393aa257b..23e844e164 100644
--- a/deps/v8/src/compiler/operator.h
+++ b/deps/v8/src/compiler/operator.h
@@ -12,6 +12,7 @@
 #include "src/base/functional.h"
 #include "src/common/globals.h"
 #include "src/handles/handles.h"
+#include "src/objects/feedback-cell.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
@@ -47,9 +48,9 @@ class V8_EXPORT_PRIVATE Operator : public NON_EXPORTED_BASE(ZoneObject) {
     kNoThrow = 1 << 5,      // Can never generate an exception.
     kNoDeopt = 1 << 6,      // Can never generate an eager deoptimization exit.
     kFoldable = kNoRead | kNoWrite,
-    kKontrol = kNoDeopt | kFoldable | kNoThrow,
     kEliminatable = kNoDeopt | kNoWrite | kNoThrow,
-    kPure = kNoDeopt | kNoRead | kNoWrite | kNoThrow | kIdempotent
+    kKontrol = kNoDeopt | kFoldable | kNoThrow,
+    kPure = kKontrol | kIdempotent
   };
 
 // List of all bits, for the visualizer.
@@ -230,20 +231,10 @@ struct OpEqualTo<double> : public base::bit_equal_to<double> {};
 template <>
 struct OpHash<double> : public base::bit_hash<double> {};
 
-template <>
-struct OpEqualTo<Handle<HeapObject>> : public Handle<HeapObject>::equal_to {};
-template <>
-struct OpHash<Handle<HeapObject>> : public Handle<HeapObject>::hash {};
-
-template <>
-struct OpEqualTo<Handle<String>> : public Handle<String>::equal_to {};
-template <>
-struct OpHash<Handle<String>> : public Handle<String>::hash {};
-
-template <>
-struct OpEqualTo<Handle<ScopeInfo>> : public Handle<ScopeInfo>::equal_to {};
-template <>
-struct OpHash<Handle<ScopeInfo>> : public Handle<ScopeInfo>::hash {};
+template <class T>
+struct OpEqualTo<Handle<T>> : public Handle<T>::equal_to {};
+template <class T>
+struct OpHash<Handle<T>> : public Handle<T>::hash {};
 
 }  // namespace compiler
 }  // namespace internal
diff --git a/deps/v8/src/compiler/pipeline.cc b/deps/v8/src/compiler/pipeline.cc
index e7285f0074..71cef6fd70 100644
--- a/deps/v8/src/compiler/pipeline.cc
+++ b/deps/v8/src/compiler/pipeline.cc
@@ -2621,6 +2621,9 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
   PipelineData data(&zone_stats, &info, isolate, isolate->allocator(), graph,
                     jsgraph, nullptr, source_positions, &node_origins,
                     should_optimize_jumps ? &jump_opt : nullptr, options);
+  PipelineJobScope scope(&data, isolate->counters()->runtime_call_stats());
+  RuntimeCallTimerScope timer_scope(isolate,
+                                    RuntimeCallCounterId::kOptimizeCode);
   data.set_verify_graph(FLAG_verify_csa);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
@@ -2672,6 +2675,8 @@ MaybeHandle<Code> Pipeline::GenerateCodeForCodeStub(
                            data.graph(), data.jsgraph(), data.schedule(),
                            data.source_positions(), data.node_origins(),
                            data.jump_optimization_info(), options);
+  PipelineJobScope second_scope(&second_data,
+                                isolate->counters()->runtime_call_stats());
   second_data.set_verify_graph(FLAG_verify_csa);
   PipelineImpl second_pipeline(&second_data);
   second_pipeline.SelectInstructionsAndAssemble(call_descriptor);
@@ -2765,7 +2770,8 @@ wasm::WasmCompilationResult Pipeline::GenerateCodeForWasmNativeStub(
       static_cast<int>(code_generator->GetHandlerTableOffset()));
   result.instr_buffer = instruction_buffer->ReleaseBuffer();
   result.source_positions = code_generator->GetSourcePositionTable();
-  result.protected_instructions = code_generator->GetProtectedInstructions();
+  result.protected_instructions_data =
+      code_generator->GetProtectedInstructionsData();
   result.frame_slot_count = code_generator->frame()->GetTotalFrameSlotCount();
   result.tagged_parameter_slots = call_descriptor->GetTaggedParameterSlots();
   result.result_tier = wasm::ExecutionTier::kTurbofan;
@@ -2972,7 +2978,8 @@ void Pipeline::GenerateCodeForWasmFunction(
   result->frame_slot_count = code_generator->frame()->GetTotalFrameSlotCount();
   result->tagged_parameter_slots = call_descriptor->GetTaggedParameterSlots();
   result->source_positions = code_generator->GetSourcePositionTable();
-  result->protected_instructions = code_generator->GetProtectedInstructions();
+  result->protected_instructions_data =
+      code_generator->GetProtectedInstructionsData();
   result->result_tier = wasm::ExecutionTier::kTurbofan;
 
   if (data.info()->trace_turbo_json_enabled()) {
diff --git a/deps/v8/src/compiler/redundancy-elimination.cc b/deps/v8/src/compiler/redundancy-elimination.cc
index 62f1ca739c..d0bac9bfc0 100644
--- a/deps/v8/src/compiler/redundancy-elimination.cc
+++ b/deps/v8/src/compiler/redundancy-elimination.cc
@@ -21,6 +21,7 @@ Reduction RedundancyElimination::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kCheckBigInt:
     case IrOpcode::kCheckBounds:
+    case IrOpcode::kCheckClosure:
     case IrOpcode::kCheckEqualsInternalizedString:
     case IrOpcode::kCheckEqualsSymbol:
     case IrOpcode::kCheckFloat64Hole:
diff --git a/deps/v8/src/compiler/representation-change.cc b/deps/v8/src/compiler/representation-change.cc
index 2c0cb76708..45d0ec994c 100644
--- a/deps/v8/src/compiler/representation-change.cc
+++ b/deps/v8/src/compiler/representation-change.cc
@@ -889,12 +889,12 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
     if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
         use_info.type_check() == TypeCheckKind::kSigned32 ||
         use_info.type_check() == TypeCheckKind::kArrayIndex) {
-      bool indentify_zeros = use_info.truncation().IdentifiesZeroAndMinusZero();
+      bool identify_zeros = use_info.truncation().IdentifiesZeroAndMinusZero();
       if (output_type.Is(Type::Signed32()) ||
-          (indentify_zeros && output_type.Is(Type::Signed32OrMinusZero()))) {
+          (identify_zeros && output_type.Is(Type::Signed32OrMinusZero()))) {
         return node;
       } else if (output_type.Is(Type::Unsigned32()) ||
-                 (indentify_zeros &&
+                 (identify_zeros &&
                   output_type.Is(Type::Unsigned32OrMinusZero()))) {
         op = simplified()->CheckedUint32ToInt32(use_info.feedback());
       } else {
diff --git a/deps/v8/src/compiler/representation-change.h b/deps/v8/src/compiler/representation-change.h
index ad9e1d6041..78fa1fbe9d 100644
--- a/deps/v8/src/compiler/representation-change.h
+++ b/deps/v8/src/compiler/representation-change.h
@@ -196,6 +196,9 @@ class UseInfo {
   static UseInfo Float32() {
     return UseInfo(MachineRepresentation::kFloat32, Truncation::Any());
   }
+  static UseInfo Float64() {
+    return UseInfo(MachineRepresentation::kFloat64, Truncation::Any());
+  }
   static UseInfo TruncatingFloat64(
       IdentifyZeros identify_zeros = kDistinguishZeros) {
     return UseInfo(MachineRepresentation::kFloat64,
diff --git a/deps/v8/src/compiler/serializer-for-background-compilation.cc b/deps/v8/src/compiler/serializer-for-background-compilation.cc
index 8ae19bc0c5..c6e352d90a 100644
--- a/deps/v8/src/compiler/serializer-for-background-compilation.cc
+++ b/deps/v8/src/compiler/serializer-for-background-compilation.cc
@@ -87,7 +87,6 @@ namespace compiler {
 
 #define IGNORED_BYTECODE_LIST(V)      \
   V(IncBlockCounter)                  \
-  V(StackCheck)                       \
   V(ThrowSuperAlreadyCalledIfNotHole) \
   V(ThrowSuperNotCalledIfHole)
 
@@ -2082,7 +2081,8 @@ void SerializerForBackgroundCompilation::ProcessCallOrConstruct(
       speculation_mode = feedback.AsCall().speculation_mode();
       // Incorporate target feedback into hints copy to simplify processing.
       base::Optional<HeapObjectRef> target = feedback.AsCall().target();
-      if (target.has_value() && target->map().is_callable()) {
+      if (target.has_value() &&
+          (target->map().is_callable() || target->IsFeedbackCell())) {
         callee = callee.Copy(zone());
         // TODO(mvstanton): if the map isn't callable then we have an allocation
         // site, and it may make sense to add the Array JSFunction constant.
@@ -2092,8 +2092,19 @@ void SerializerForBackgroundCompilation::ProcessCallOrConstruct(
           new_target->AddConstant(target->object(), zone(), broker());
           callee.AddConstant(target->object(), zone(), broker());
         } else {
-          // Call; target is callee.
-          callee.AddConstant(target->object(), zone(), broker());
+          // Call; target is feedback cell or callee.
+          if (target->IsFeedbackCell() &&
+              target->AsFeedbackCell().value().IsFeedbackVector()) {
+            FeedbackVectorRef vector =
+                target->AsFeedbackCell().value().AsFeedbackVector();
+            vector.Serialize();
+            VirtualClosure virtual_closure(
+                vector.shared_function_info().object(), vector.object(),
+                Hints());
+            callee.AddVirtualClosure(virtual_closure, zone(), broker());
+          } else {
+            callee.AddConstant(target->object(), zone(), broker());
+          }
         }
       }
     }
diff --git a/deps/v8/src/compiler/simd-scalar-lowering.cc b/deps/v8/src/compiler/simd-scalar-lowering.cc
index b5e0410d50..db5a736855 100644
--- a/deps/v8/src/compiler/simd-scalar-lowering.cc
+++ b/deps/v8/src/compiler/simd-scalar-lowering.cc
@@ -4,8 +4,10 @@
 
 #include "src/compiler/simd-scalar-lowering.h"
 
+#include "src/codegen/machine-type.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/linkage.h"
+#include "src/compiler/machine-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/node.h"
@@ -111,6 +113,7 @@ void SimdScalarLowering::LowerGraph() {
   V(I32x4LeU)                     \
   V(I32x4GtU)                     \
   V(I32x4GeU)                     \
+  V(I32x4Abs)                     \
   V(S128And)                      \
   V(S128Or)                       \
   V(S128Xor)                      \
@@ -183,7 +186,9 @@ void SimdScalarLowering::LowerGraph() {
   V(I16x8LtS)                     \
   V(I16x8LeS)                     \
   V(I16x8LtU)                     \
-  V(I16x8LeU)
+  V(I16x8LeU)                     \
+  V(I16x8RoundingAverageU)        \
+  V(I16x8Abs)
 
 #define FOREACH_INT8X16_OPCODE(V) \
   V(I8x16Splat)                   \
@@ -214,7 +219,9 @@ void SimdScalarLowering::LowerGraph() {
   V(I8x16LtU)                     \
   V(I8x16LeU)                     \
   V(S8x16Swizzle)                 \
-  V(S8x16Shuffle)
+  V(S8x16Shuffle)                 \
+  V(I8x16RoundingAverageU)        \
+  V(I8x16Abs)
 
 MachineType SimdScalarLowering::MachineTypeFrom(SimdType simdType) {
   switch (simdType) {
@@ -268,6 +275,31 @@ void SimdScalarLowering::SetLoweredType(Node* node, Node* output) {
         replacements_[node->id()].type = SimdType::kInt8x16;
         break;
       }
+    case IrOpcode::kLoadTransform: {
+      LoadTransformParameters params = LoadTransformParametersOf(node->op());
+      switch (params.transformation) {
+        case LoadTransformation::kS8x16LoadSplat:
+          replacements_[node->id()].type = SimdType::kInt8x16;
+          break;
+        case LoadTransformation::kS16x8LoadSplat:
+          replacements_[node->id()].type = SimdType::kInt16x8;
+          break;
+        case LoadTransformation::kS32x4LoadSplat:
+          replacements_[node->id()].type = SimdType::kInt32x4;
+          break;
+        case LoadTransformation::kI16x8Load8x8S:
+        case LoadTransformation::kI16x8Load8x8U:
+          replacements_[node->id()].type = SimdType::kInt16x8;
+          break;
+        case LoadTransformation::kI32x4Load16x4S:
+        case LoadTransformation::kI32x4Load16x4U:
+          replacements_[node->id()].type = SimdType::kInt32x4;
+          break;
+        default:
+          UNIMPLEMENTED();
+      }
+      break;
+    }
     default: {
       switch (output->opcode()) {
         case IrOpcode::kF32x4SConvertI32x4:
@@ -426,6 +458,84 @@ void SimdScalarLowering::LowerLoadOp(Node* node, SimdType type) {
   }
 }
 
+void SimdScalarLowering::LowerLoadTransformOp(Node* node, SimdType type) {
+  LoadTransformParameters params = LoadTransformParametersOf(node->op());
+  MachineType load_rep = MachineType::None();
+  SimdType load_type = type;
+
+  // Load extends have a different machine type for loading.
+  switch (params.transformation) {
+    case LoadTransformation::kI16x8Load8x8S:
+      load_rep = MachineType::Int8();
+      load_type = SimdType::kInt8x16;
+      break;
+    case LoadTransformation::kI16x8Load8x8U:
+      load_rep = MachineType::Uint8();
+      load_type = SimdType::kInt8x16;
+      break;
+    case LoadTransformation::kI32x4Load16x4S:
+      load_rep = MachineType::Int16();
+      load_type = SimdType::kInt16x8;
+      break;
+    case LoadTransformation::kI32x4Load16x4U:
+      load_rep = MachineType::Uint16();
+      load_type = SimdType::kInt16x8;
+      break;
+    case LoadTransformation::kS8x16LoadSplat:
+    case LoadTransformation::kS16x8LoadSplat:
+    case LoadTransformation::kS32x4LoadSplat:
+      load_rep = MachineTypeFrom(type);
+      break;
+    default:
+      // Lowering for s64x2 is not implemented since lowering for 64x2
+      // operations doesn't work properly yet.
+      UNIMPLEMENTED();
+  }
+
+  DCHECK_NE(load_rep, MachineType::None());
+
+  const Operator* load_op;
+  switch (params.kind) {
+    case LoadKind::kNormal:
+      load_op = machine()->Load(load_rep);
+      break;
+    case LoadKind::kUnaligned:
+      load_op = machine()->UnalignedLoad(load_rep);
+      break;
+    case LoadKind::kProtected:
+      load_op = machine()->ProtectedLoad(load_rep);
+      break;
+  }
+
+  Node* base = node->InputAt(0);
+  Node* index = node->InputAt(1);
+  int num_lanes = NumLanes(type);
+  Node** rep_nodes = zone()->NewArray<Node*>(num_lanes);
+  Node* effect_input = node->InputAt(2);
+  Node* control_input = node->InputAt(3);
+
+  if (type != load_type) {
+    // We load a smaller lane size, then extend to a larger lane size. So use
+    // the smaller lane size to calculte the index nodes for loads, but only
+    // actually load half of those lanes.
+    Node** indices = zone()->NewArray<Node*>(num_lanes * 2);
+    GetIndexNodes(index, indices, load_type);
+    for (int i = num_lanes - 1; i >= 0; --i) {
+      rep_nodes[i] = graph()->NewNode(load_op, base, indices[i], effect_input,
+                                      control_input);
+      effect_input = rep_nodes[i];
+    }
+  } else {
+    // Load splat, load from the same index for every lane.
+    for (int i = num_lanes - 1; i >= 0; --i) {
+      rep_nodes[i] =
+          graph()->NewNode(load_op, base, index, effect_input, control_input);
+      effect_input = rep_nodes[i];
+    }
+  }
+  ReplaceNode(node, rep_nodes, num_lanes);
+}
+
 void SimdScalarLowering::LowerStoreOp(Node* node) {
   // For store operation, use replacement type of its input instead of the
   // one of its effected node.
@@ -973,6 +1083,10 @@ void SimdScalarLowering::LowerNode(Node* node) {
       LowerLoadOp(node, rep_type);
       break;
     }
+    case IrOpcode::kLoadTransform: {
+      LowerLoadTransformOp(node, rep_type);
+      break;
+    }
     case IrOpcode::kStore:
     case IrOpcode::kUnalignedStore:
     case IrOpcode::kProtectedStore: {
@@ -1127,6 +1241,30 @@ void SimdScalarLowering::LowerNode(Node* node) {
       ReplaceNode(node, rep_node, num_lanes);
       break;
     }
+    case IrOpcode::kI32x4Abs:
+    case IrOpcode::kI16x8Abs:
+    case IrOpcode::kI8x16Abs: {
+      // From https://stackoverflow.com/a/14194764
+      // abs(x) = (x XOR y) - y
+      Node** rep = GetReplacementsWithType(node->InputAt(0), rep_type);
+      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
+      for (int i = 0; i < num_lanes; ++i) {
+        // It's fine to shift by 31 even for i8x16 since each node is
+        // effectively expanded to 32 bits.
+        Node* y = graph()->NewNode(machine()->Word32Sar(), rep[i],
+                                   mcgraph_->Int32Constant(31));
+        rep_node[i] = graph()->NewNode(
+            machine()->Int32Sub(),
+            graph()->NewNode(machine()->Word32Xor(), rep[i], y), y);
+        if (node->opcode() == IrOpcode::kI16x8Neg) {
+          rep_node[i] = FixUpperBits(rep_node[i], kShift16);
+        } else if (node->opcode() == IrOpcode::kI8x16Neg) {
+          rep_node[i] = FixUpperBits(rep_node[i], kShift8);
+        }
+      }
+      ReplaceNode(node, rep_node, num_lanes);
+      break;
+    }
     case IrOpcode::kS128Zero: {
       DCHECK_EQ(0, node->InputCount());
       Node* rep_node[kNumLanes32];
@@ -1506,6 +1644,26 @@ void SimdScalarLowering::LowerNode(Node* node) {
       ReplaceNode(node, rep_node, num_lanes);
       break;
     }
+    case IrOpcode::kI8x16RoundingAverageU:
+    case IrOpcode::kI16x8RoundingAverageU: {
+      DCHECK_EQ(2, node->InputCount());
+      Node** rep_left = GetReplacementsWithType(node->InputAt(0), rep_type);
+      Node** rep_right = GetReplacementsWithType(node->InputAt(1), rep_type);
+      int num_lanes = NumLanes(rep_type);
+      Node** rep_node = zone()->NewArray<Node*>(num_lanes);
+      // rounding_average(left, right) = (left + right + 1) >> 1
+      for (int i = 0; i < num_lanes; ++i) {
+        Node* left_plus_right_plus_one = graph()->NewNode(
+            machine()->Int32Add(),
+            graph()->NewNode(machine()->Int32Add(), rep_left[i], rep_right[i]),
+            mcgraph_->Int32Constant(1));
+        rep_node[i] =
+            graph()->NewNode(machine()->Word32Shr(), left_plus_right_plus_one,
+                             mcgraph_->Int32Constant(1));
+      }
+      ReplaceNode(node, rep_node, num_lanes);
+      break;
+    }
     default: { DefaultLowering(node); }
   }
 }
diff --git a/deps/v8/src/compiler/simd-scalar-lowering.h b/deps/v8/src/compiler/simd-scalar-lowering.h
index 76723fcc77..d91e6285f4 100644
--- a/deps/v8/src/compiler/simd-scalar-lowering.h
+++ b/deps/v8/src/compiler/simd-scalar-lowering.h
@@ -85,6 +85,7 @@ class SimdScalarLowering {
   void SetLoweredType(Node* node, Node* output);
   void GetIndexNodes(Node* index, Node** new_indices, SimdType type);
   void LowerLoadOp(Node* node, SimdType type);
+  void LowerLoadTransformOp(Node* node, SimdType type);
   void LowerStoreOp(Node* node);
   void LowerBinaryOp(Node* node, SimdType input_rep_type, const Operator* op,
                      bool not_horizontal = true);
diff --git a/deps/v8/src/compiler/simplified-lowering.cc b/deps/v8/src/compiler/simplified-lowering.cc
index 8997a5a831..aa222af96c 100644
--- a/deps/v8/src/compiler/simplified-lowering.cc
+++ b/deps/v8/src/compiler/simplified-lowering.cc
@@ -6,8 +6,11 @@
 
 #include <limits>
 
+#include "include/v8-fast-api-calls.h"
 #include "src/base/bits.h"
+#include "src/base/small-vector.h"
 #include "src/codegen/code-factory.h"
+#include "src/codegen/machine-type.h"
 #include "src/codegen/tick-counter.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
@@ -1643,7 +1646,8 @@ class RepresentationSelector {
   }
 
   void VisitCheckBounds(Node* node, SimplifiedLowering* lowering) {
-    CheckParameters const& p = CheckParametersOf(node->op());
+    CheckBoundsParameters const& p = CheckBoundsParametersOf(node->op());
+    FeedbackSource const& feedback = p.check_parameters().feedback();
     Type const index_type = TypeOf(node->InputAt(0));
     Type const length_type = TypeOf(node->InputAt(1));
     if (length_type.Is(Type::Unsigned31())) {
@@ -1654,8 +1658,7 @@ class RepresentationSelector {
         VisitBinop(node, UseInfo::TruncatingWord32(),
                    MachineRepresentation::kWord32);
         if (lower()) {
-          CheckBoundsParameters::Mode mode =
-              CheckBoundsParameters::kDeoptOnOutOfBounds;
+          CheckBoundsParameters::Mode mode = p.mode();
           if (lowering->poisoning_level_ ==
                   PoisoningMitigationLevel::kDontPoison &&
               (index_type.IsNone() || length_type.IsNone() ||
@@ -1666,32 +1669,126 @@ class RepresentationSelector {
             mode = CheckBoundsParameters::kAbortOnOutOfBounds;
           }
           NodeProperties::ChangeOp(
-              node, simplified()->CheckedUint32Bounds(p.feedback(), mode));
+              node, simplified()->CheckedUint32Bounds(feedback, mode));
         }
       } else {
-        VisitBinop(node, UseInfo::CheckedTaggedAsArrayIndex(p.feedback()),
+        VisitBinop(node, UseInfo::CheckedTaggedAsArrayIndex(feedback),
                    UseInfo::Word(), MachineType::PointerRepresentation());
         if (lower()) {
           if (jsgraph_->machine()->Is64()) {
             NodeProperties::ChangeOp(
-                node, simplified()->CheckedUint64Bounds(p.feedback()));
+                node, simplified()->CheckedUint64Bounds(feedback, p.mode()));
           } else {
             NodeProperties::ChangeOp(
-                node,
-                simplified()->CheckedUint32Bounds(
-                    p.feedback(), CheckBoundsParameters::kDeoptOnOutOfBounds));
+                node, simplified()->CheckedUint32Bounds(feedback, p.mode()));
           }
         }
       }
     } else {
-      DCHECK(length_type.Is(type_cache_->kPositiveSafeInteger));
+      CHECK(length_type.Is(type_cache_->kPositiveSafeInteger));
       VisitBinop(node,
-                 UseInfo::CheckedSigned64AsWord64(kIdentifyZeros, p.feedback()),
+                 UseInfo::CheckedSigned64AsWord64(kIdentifyZeros, feedback),
                  UseInfo::Word64(), MachineRepresentation::kWord64);
       if (lower()) {
         NodeProperties::ChangeOp(
-            node, simplified()->CheckedUint64Bounds(p.feedback()));
+            node, simplified()->CheckedUint64Bounds(feedback, p.mode()));
+      }
+    }
+  }
+
+  static MachineType MachineTypeFor(CTypeInfo::Type type) {
+    switch (type) {
+      case CTypeInfo::Type::kVoid:
+        return MachineType::Int32();
+      case CTypeInfo::Type::kBool:
+        return MachineType::Bool();
+      case CTypeInfo::Type::kInt32:
+        return MachineType::Int32();
+      case CTypeInfo::Type::kUint32:
+        return MachineType::Uint32();
+      case CTypeInfo::Type::kInt64:
+        return MachineType::Int64();
+      case CTypeInfo::Type::kUint64:
+        return MachineType::Uint64();
+      case CTypeInfo::Type::kFloat32:
+        return MachineType::Float32();
+      case CTypeInfo::Type::kFloat64:
+        return MachineType::Float64();
+      case CTypeInfo::Type::kUnwrappedApiObject:
+        return MachineType::Pointer();
+    }
+  }
+
+  UseInfo UseInfoForFastApiCallArgument(CTypeInfo::Type type,
+                                        FeedbackSource const& feedback) {
+    switch (type) {
+      case CTypeInfo::Type::kVoid:
+        UNREACHABLE();
+      case CTypeInfo::Type::kBool:
+        return UseInfo::Bool();
+      case CTypeInfo::Type::kInt32:
+      case CTypeInfo::Type::kUint32:
+      case CTypeInfo::Type::kFloat32:
+        return UseInfo::CheckedNumberAsWord32(feedback);
+      case CTypeInfo::Type::kInt64:
+        return UseInfo::CheckedSigned64AsWord64(kIdentifyZeros, feedback);
+      case CTypeInfo::Type::kFloat64:
+        return UseInfo::CheckedNumberAsFloat64(kIdentifyZeros, feedback);
+      // UseInfo::Word64 does not propagate any TypeCheckKind, so it relies
+      // on the implicit assumption that Word64 representation only holds
+      // Numbers, which is already no longer true with BigInts. By now,
+      // BigInts are handled in a very conservative way to make sure they don't
+      // fall into that pit, but future changes may break this here.
+      case CTypeInfo::Type::kUint64:
+        return UseInfo::Word64();
+      case CTypeInfo::Type::kUnwrappedApiObject:
+        return UseInfo::Word();
+    }
+  }
+
+  static constexpr int kInitialArgumentsCount = 10;
+
+  void VisitFastApiCall(Node* node) {
+    FastApiCallParameters const& params = FastApiCallParametersOf(node->op());
+    const CFunctionInfo* c_signature = params.signature();
+    int c_arg_count = c_signature->ArgumentCount();
+    int value_input_count = node->op()->ValueInputCount();
+    // function, ... C args
+    CHECK_EQ(c_arg_count + 1, value_input_count);
+
+    base::SmallVector<UseInfo, kInitialArgumentsCount> arg_use_info(
+        c_arg_count);
+    ProcessInput(node, 0, UseInfo::Word());
+    // Propagate representation information from TypeInfo.
+    for (int i = 0; i < c_arg_count; i++) {
+      arg_use_info[i] = UseInfoForFastApiCallArgument(
+          c_signature->ArgumentInfo(i).GetType(), params.feedback());
+      ProcessInput(node, i + 1, arg_use_info[i]);
+    }
+
+    MachineType return_type =
+        MachineTypeFor(c_signature->ReturnInfo().GetType());
+    SetOutput(node, return_type.representation());
+
+    if (lower()) {
+      MachineSignature::Builder builder(graph()->zone(), 1, c_arg_count);
+      builder.AddReturn(return_type);
+      for (int i = 0; i < c_arg_count; ++i) {
+        MachineType machine_type =
+            MachineTypeFor(c_signature->ArgumentInfo(i).GetType());
+        // Here the arg_use_info are indexed starting from 1 because of the
+        // function input, while this loop is only over the actual arguments.
+        DCHECK_EQ(arg_use_info[i].representation(),
+                  machine_type.representation());
+        builder.AddParam(machine_type);
       }
+
+      CallDescriptor* call_descriptor = Linkage::GetSimplifiedCDescriptor(
+          graph()->zone(), builder.Build(), CallDescriptor::kNoFlags);
+
+      call_descriptor->SetCFunctionInfo(c_signature);
+
+      NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
     }
   }
 
@@ -3428,6 +3525,12 @@ class RepresentationSelector {
         VisitUnop(node, UseInfo::AnyTagged(), MachineRepresentation::kTagged);
         return;
       }
+      case IrOpcode::kCheckClosure: {
+        VisitUnop(node,
+                  UseInfo::CheckedHeapObjectAsTaggedPointer(FeedbackSource()),
+                  MachineRepresentation::kTaggedPointer);
+        return;
+      }
       case IrOpcode::kConvertTaggedHoleToUndefined: {
         if (InputIs(node, Type::NumberOrOddball()) &&
             truncation.IsUsedAsWord32()) {
@@ -3510,6 +3613,7 @@ class RepresentationSelector {
         return VisitObjectState(node);
       case IrOpcode::kObjectId:
         return SetOutput(node, MachineRepresentation::kTaggedPointer);
+
       case IrOpcode::kTypeGuard: {
         // We just get rid of the sigma here, choosing the best representation
         // for the sigma's type.
@@ -3530,6 +3634,10 @@ class RepresentationSelector {
         return;
       }
 
+      case IrOpcode::kFoldConstant:
+        VisitInputs(node);
+        return SetOutput(node, MachineRepresentation::kTaggedPointer);
+
       case IrOpcode::kFinishRegion:
         VisitInputs(node);
         // Assume the output is tagged pointer.
@@ -3557,6 +3665,11 @@ class RepresentationSelector {
         return;
       }
 
+      case IrOpcode::kFastApiCall: {
+        VisitFastApiCall(node);
+        return;
+      }
+
       // Operators with all inputs tagged and no or tagged output have uniform
       // handling.
       case IrOpcode::kEnd:
diff --git a/deps/v8/src/compiler/simplified-operator.cc b/deps/v8/src/compiler/simplified-operator.cc
index 41547fd132..2b1e0ab99e 100644
--- a/deps/v8/src/compiler/simplified-operator.cc
+++ b/deps/v8/src/compiler/simplified-operator.cc
@@ -4,11 +4,13 @@
 
 #include "src/compiler/simplified-operator.h"
 
+#include "include/v8-fast-api-calls.h"
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/compiler/types.h"
 #include "src/handles/handles-inl.h"
+#include "src/objects/feedback-cell.h"
 #include "src/objects/map.h"
 #include "src/objects/name.h"
 #include "src/objects/objects-inl.h"
@@ -820,7 +822,6 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(CheckedUint32Mod, 2, 1)
 
 #define CHECKED_WITH_FEEDBACK_OP_LIST(V)    \
-  V(CheckBounds, 2, 1)                      \
   V(CheckNumber, 1, 1)                      \
   V(CheckSmi, 1, 1)                         \
   V(CheckString, 1, 1)                      \
@@ -834,11 +835,13 @@ bool operator==(CheckMinusZeroParameters const& lhs,
   V(CheckedTaggedToTaggedSigned, 1, 1)      \
   V(CheckedUint32ToInt32, 1, 1)             \
   V(CheckedUint32ToTaggedSigned, 1, 1)      \
-  V(CheckedUint64Bounds, 2, 1)              \
   V(CheckedUint64ToInt32, 1, 1)             \
   V(CheckedUint64ToTaggedSigned, 1, 1)
 
-#define CHECKED_BOUNDS_OP_LIST(V) V(CheckedUint32Bounds)
+#define CHECKED_BOUNDS_OP_LIST(V) \
+  V(CheckBounds)                  \
+  V(CheckedUint32Bounds)          \
+  V(CheckedUint64Bounds)
 
 struct SimplifiedOperatorGlobalCache final {
 #define PURE(Name, properties, value_input_count, control_input_count)     \
@@ -851,16 +854,14 @@ struct SimplifiedOperatorGlobalCache final {
   PURE_OP_LIST(PURE)
 #undef PURE
 
-#define EFFECT_DEPENDENT(Name, properties, value_input_count,              \
-                         control_input_count)                              \
-  struct Name##Operator final : public Operator {                          \
-    Name##Operator()                                                       \
-        : Operator(IrOpcode::k##Name,                                      \
-                   Operator::kNoDeopt | Operator::kNoWrite |               \
-                       Operator::kNoThrow | properties,                    \
-                   #Name, value_input_count, 1, control_input_count, 1, 1, \
-                   0) {}                                                   \
-  };                                                                       \
+#define EFFECT_DEPENDENT(Name, properties, value_input_count,               \
+                         control_input_count)                               \
+  struct Name##Operator final : public Operator {                           \
+    Name##Operator()                                                        \
+        : Operator(IrOpcode::k##Name, Operator::kEliminatable | properties, \
+                   #Name, value_input_count, 1, control_input_count, 1, 1,  \
+                   0) {}                                                    \
+  };                                                                        \
   Name##Operator k##Name;
   EFFECT_DEPENDENT_OP_LIST(EFFECT_DEPENDENT)
 #undef EFFECT_DEPENDENT
@@ -1126,10 +1127,9 @@ struct SimplifiedOperatorGlobalCache final {
     LoadStackArgumentOperator()
         : Operator(                          // --
               IrOpcode::kLoadStackArgument,  // opcode
-              Operator::kNoDeopt | Operator::kNoThrow |
-                  Operator::kNoWrite,  // flags
-              "LoadStackArgument",     // name
-              2, 1, 1, 1, 1, 0) {}     // counts
+              Operator::kEliminatable,       // flags
+              "LoadStackArgument",           // name
+              2, 1, 1, 1, 1, 0) {}           // counts
   };
   LoadStackArgumentOperator kLoadStackArgument;
 
@@ -1256,6 +1256,16 @@ const Operator* SimplifiedOperatorBuilder::AssertType(Type type) {
                                       "AssertType", 1, 0, 0, 1, 0, 0, type);
 }
 
+const Operator* SimplifiedOperatorBuilder::FastApiCall(
+    const CFunctionInfo* signature, FeedbackSource const& feedback) {
+  // function, c args
+  int value_input_count = signature->ArgumentCount() + 1;
+  return new (zone()) Operator1<FastApiCallParameters>(
+      IrOpcode::kFastApiCall, Operator::kNoThrow, "FastApiCall",
+      value_input_count, 1, 1, 1, 1, 0,
+      FastApiCallParameters(signature, feedback));
+}
+
 const Operator* SimplifiedOperatorBuilder::CheckIf(
     DeoptimizeReason reason, const FeedbackSource& feedback) {
   if (!feedback.IsValid()) {
@@ -1476,6 +1486,21 @@ const Operator* SimplifiedOperatorBuilder::SpeculativeBigIntNegate(
       1, 1, 1, 0, hint);
 }
 
+const Operator* SimplifiedOperatorBuilder::CheckClosure(
+    const Handle<FeedbackCell>& feedback_cell) {
+  return new (zone()) Operator1<Handle<FeedbackCell>>(  // --
+      IrOpcode::kCheckClosure,                          // opcode
+      Operator::kNoThrow | Operator::kNoWrite,          // flags
+      "CheckClosure",                                   // name
+      1, 1, 1, 1, 1, 0,                                 // counts
+      feedback_cell);                                   // parameter
+}
+
+Handle<FeedbackCell> FeedbackCellOf(const Operator* op) {
+  DCHECK(IrOpcode::kCheckClosure == op->opcode());
+  return OpParameter<Handle<FeedbackCell>>(op);
+}
+
 const Operator* SimplifiedOperatorBuilder::SpeculativeToNumber(
     NumberOperationHint hint, const FeedbackSource& feedback) {
   if (!feedback.IsValid()) {
@@ -1589,7 +1614,9 @@ std::ostream& operator<<(std::ostream& os, CheckParameters const& p) {
 }
 
 CheckParameters const& CheckParametersOf(Operator const* op) {
-  if (op->opcode() == IrOpcode::kCheckedUint32Bounds) {
+  if (op->opcode() == IrOpcode::kCheckBounds ||
+      op->opcode() == IrOpcode::kCheckedUint32Bounds ||
+      op->opcode() == IrOpcode::kCheckedUint64Bounds) {
     return OpParameter<CheckBoundsParameters>(op).check_parameters();
   }
 #define MAKE_OR(name, arg2, arg3) op->opcode() == IrOpcode::k##name ||
@@ -1622,7 +1649,9 @@ std::ostream& operator<<(std::ostream& os, CheckBoundsParameters const& p) {
 }
 
 CheckBoundsParameters const& CheckBoundsParametersOf(Operator const* op) {
-  CHECK_EQ(op->opcode(), IrOpcode::kCheckedUint32Bounds);
+  DCHECK(op->opcode() == IrOpcode::kCheckBounds ||
+         op->opcode() == IrOpcode::kCheckedUint32Bounds ||
+         op->opcode() == IrOpcode::kCheckedUint64Bounds);
   return OpParameter<CheckBoundsParameters>(op);
 }
 
@@ -1679,12 +1708,30 @@ int NewArgumentsElementsMappedCountOf(const Operator* op) {
   return OpParameter<int>(op);
 }
 
+FastApiCallParameters const& FastApiCallParametersOf(const Operator* op) {
+  DCHECK_EQ(IrOpcode::kFastApiCall, op->opcode());
+  return OpParameter<FastApiCallParameters>(op);
+}
+
+std::ostream& operator<<(std::ostream& os, FastApiCallParameters const& p) {
+  return os << p.signature() << ", " << p.feedback();
+}
+
+size_t hash_value(FastApiCallParameters const& p) {
+  return base::hash_combine(p.signature(),
+                            FeedbackSource::Hash()(p.feedback()));
+}
+
+bool operator==(FastApiCallParameters const& lhs,
+                FastApiCallParameters const& rhs) {
+  return lhs.signature() == rhs.signature() && lhs.feedback() == rhs.feedback();
+}
+
 const Operator* SimplifiedOperatorBuilder::Allocate(Type type,
                                                     AllocationType allocation) {
   return new (zone()) Operator1<AllocateParameters>(
-      IrOpcode::kAllocate,
-      Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite, "Allocate",
-      1, 1, 1, 1, 1, 0, AllocateParameters(type, allocation));
+      IrOpcode::kAllocate, Operator::kEliminatable, "Allocate", 1, 1, 1, 1, 1,
+      0, AllocateParameters(type, allocation));
 }
 
 const Operator* SimplifiedOperatorBuilder::AllocateRaw(
@@ -1696,10 +1743,8 @@ const Operator* SimplifiedOperatorBuilder::AllocateRaw(
            allocation == AllocationType::kYoung &&
            !FLAG_young_generation_large_objects));
   return new (zone()) Operator1<AllocateParameters>(
-      IrOpcode::kAllocateRaw,
-      Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,
-      "AllocateRaw", 1, 1, 1, 1, 1, 1,
-      AllocateParameters(type, allocation, allow_large_objects));
+      IrOpcode::kAllocateRaw, Operator::kEliminatable, "AllocateRaw", 1, 1, 1,
+      1, 1, 1, AllocateParameters(type, allocation, allow_large_objects));
 }
 
 #define SPECULATIVE_NUMBER_BINOP(Name)                                        \
@@ -1747,10 +1792,8 @@ ACCESS_OP_LIST(ACCESS)
 #undef ACCESS
 
 const Operator* SimplifiedOperatorBuilder::LoadMessage() {
-  return new (zone())
-      Operator(IrOpcode::kLoadMessage,
-               Operator::kNoDeopt | Operator::kNoThrow | Operator::kNoWrite,
-               "LoadMessage", 1, 1, 1, 1, 1, 0);
+  return new (zone()) Operator(IrOpcode::kLoadMessage, Operator::kEliminatable,
+                               "LoadMessage", 1, 1, 1, 1, 1, 0);
 }
 
 const Operator* SimplifiedOperatorBuilder::StoreMessage() {
diff --git a/deps/v8/src/compiler/simplified-operator.h b/deps/v8/src/compiler/simplified-operator.h
index 4fc9a4be78..251bb43678 100644
--- a/deps/v8/src/compiler/simplified-operator.h
+++ b/deps/v8/src/compiler/simplified-operator.h
@@ -106,7 +106,9 @@ struct FieldAccess {
         write_barrier_kind(write_barrier_kind),
         load_sensitivity(load_sensitivity),
         const_field_info(const_field_info),
-        is_store_in_literal(is_store_in_literal) {}
+        is_store_in_literal(is_store_in_literal) {
+    DCHECK_GE(offset, 0);
+  }
 
   int tag() const { return base_is_tagged == kTaggedBase ? kHeapObjectTag : 0; }
 };
@@ -300,6 +302,9 @@ bool operator==(CheckFloat64HoleParameters const&,
 bool operator!=(CheckFloat64HoleParameters const&,
                 CheckFloat64HoleParameters const&);
 
+// Parameter for CheckClosure node.
+Handle<FeedbackCell> FeedbackCellOf(const Operator* op);
+
 enum class CheckTaggedInputMode : uint8_t {
   kNumber,
   kNumberOrOddball,
@@ -580,6 +585,30 @@ DeoptimizeReason DeoptimizeReasonOf(const Operator* op) V8_WARN_UNUSED_RESULT;
 
 int NewArgumentsElementsMappedCountOf(const Operator* op) V8_WARN_UNUSED_RESULT;
 
+class FastApiCallParameters {
+ public:
+  explicit FastApiCallParameters(const CFunctionInfo* signature,
+                                 FeedbackSource const& feedback)
+      : signature_(signature), feedback_(feedback) {}
+
+  const CFunctionInfo* signature() const { return signature_; }
+  FeedbackSource const& feedback() const { return feedback_; }
+
+ private:
+  const CFunctionInfo* signature_;
+  const FeedbackSource feedback_;
+};
+
+FastApiCallParameters const& FastApiCallParametersOf(const Operator* op)
+    V8_WARN_UNUSED_RESULT;
+
+V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream&,
+                                           FastApiCallParameters const&);
+
+size_t hash_value(FastApiCallParameters const&);
+
+bool operator==(FastApiCallParameters const&, FastApiCallParameters const&);
+
 // Interface for building simplified operators, which represent the
 // medium-level operations of V8, including adding numbers, allocating objects,
 // indexing into objects and arrays, etc.
@@ -754,7 +783,15 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
   const Operator* CompareMaps(ZoneHandleSet<Map>);
   const Operator* MapGuard(ZoneHandleSet<Map> maps);
 
-  const Operator* CheckBounds(const FeedbackSource& feedback);
+  const Operator* CheckBounds(const FeedbackSource& feedback,
+                              CheckBoundsParameters::Mode mode =
+                                  CheckBoundsParameters::kDeoptOnOutOfBounds);
+  const Operator* CheckedUint32Bounds(const FeedbackSource& feedback,
+                                      CheckBoundsParameters::Mode mode);
+  const Operator* CheckedUint64Bounds(const FeedbackSource& feedback,
+                                      CheckBoundsParameters::Mode mode);
+
+  const Operator* CheckClosure(const Handle<FeedbackCell>& feedback_cell);
   const Operator* CheckEqualsInternalizedString();
   const Operator* CheckEqualsSymbol();
   const Operator* CheckFloat64Hole(CheckFloat64HoleMode, FeedbackSource const&);
@@ -799,11 +836,8 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
                                                 const FeedbackSource& feedback);
   const Operator* CheckedUint32Div();
   const Operator* CheckedUint32Mod();
-  const Operator* CheckedUint32Bounds(const FeedbackSource& feedback,
-                                      CheckBoundsParameters::Mode mode);
   const Operator* CheckedUint32ToInt32(const FeedbackSource& feedback);
   const Operator* CheckedUint32ToTaggedSigned(const FeedbackSource& feedback);
-  const Operator* CheckedUint64Bounds(const FeedbackSource& feedback);
   const Operator* CheckedUint64ToInt32(const FeedbackSource& feedback);
   const Operator* CheckedUint64ToTaggedSigned(const FeedbackSource& feedback);
 
@@ -920,6 +954,10 @@ class V8_EXPORT_PRIVATE SimplifiedOperatorBuilder final
 
   const Operator* DateNow();
 
+  // Stores the signature and feedback of a fast C call
+  const Operator* FastApiCall(const CFunctionInfo* signature,
+                              FeedbackSource const& feedback);
+
  private:
   Zone* zone() const { return zone_; }
 
diff --git a/deps/v8/src/compiler/state-values-utils.cc b/deps/v8/src/compiler/state-values-utils.cc
index 2bb5a0a4b5..b0fc8a9b71 100644
--- a/deps/v8/src/compiler/state-values-utils.cc
+++ b/deps/v8/src/compiler/state-values-utils.cc
@@ -4,6 +4,7 @@
 
 #include "src/compiler/state-values-utils.h"
 
+#include "src/compiler/common-operator.h"
 #include "src/utils/bit-vector.h"
 
 namespace v8 {
@@ -240,9 +241,9 @@ void CheckTreeContainsValues(Node* tree, Node** values, size_t count,
   auto itend = access.end();
   for (i = 0; it != itend; ++it, ++i) {
     if (liveness == nullptr || liveness->Contains(liveness_offset + i)) {
-      DCHECK_EQ((*it).node, values[i]);
+      DCHECK_EQ(it.node(), values[i]);
     } else {
-      DCHECK_NULL((*it).node);
+      DCHECK_NULL(it.node());
     }
   }
   DCHECK_EQ(static_cast<size_t>(i), count);
@@ -329,13 +330,20 @@ void StateValuesAccess::iterator::Pop() {
   current_depth_--;
 }
 
-bool StateValuesAccess::iterator::done() const { return current_depth_ < 0; }
-
 void StateValuesAccess::iterator::Advance() {
   Top()->Advance();
   EnsureValid();
 }
 
+size_t StateValuesAccess::iterator::AdvanceTillNotEmpty() {
+  size_t count = 0;
+  while (!done() && Top()->IsEmpty()) {
+    count += Top()->AdvanceToNextRealOrEnd();
+    EnsureValid();
+  }
+  return count;
+}
+
 void StateValuesAccess::iterator::EnsureValid() {
   while (true) {
     SparseInputMask::InputIterator* top = Top();
@@ -376,21 +384,18 @@ Node* StateValuesAccess::iterator::node() { return Top()->Get(nullptr); }
 
 MachineType StateValuesAccess::iterator::type() {
   Node* parent = Top()->parent();
+  DCHECK(!Top()->IsEmpty());
   if (parent->opcode() == IrOpcode::kStateValues) {
     return MachineType::AnyTagged();
   } else {
     DCHECK_EQ(IrOpcode::kTypedStateValues, parent->opcode());
 
-    if (Top()->IsEmpty()) {
-      return MachineType::None();
-    } else {
-      ZoneVector<MachineType> const* types = MachineTypesOf(parent->op());
-      return (*types)[Top()->real_index()];
-    }
+    ZoneVector<MachineType> const* types = MachineTypesOf(parent->op());
+    return (*types)[Top()->real_index()];
   }
 }
 
-bool StateValuesAccess::iterator::operator!=(iterator const& other) {
+bool StateValuesAccess::iterator::operator!=(iterator const& other) const {
   // We only allow comparison with end().
   CHECK(other.done());
   return !done();
@@ -406,8 +411,7 @@ StateValuesAccess::TypedNode StateValuesAccess::iterator::operator*() {
   return TypedNode(node(), type());
 }
 
-
-size_t StateValuesAccess::size() {
+size_t StateValuesAccess::size() const {
   size_t count = 0;
   SparseInputMask mask = SparseInputMaskOf(node_->op());
 
diff --git a/deps/v8/src/compiler/state-values-utils.h b/deps/v8/src/compiler/state-values-utils.h
index 0ff5d218f1..7913f1df04 100644
--- a/deps/v8/src/compiler/state-values-utils.h
+++ b/deps/v8/src/compiler/state-values-utils.h
@@ -6,6 +6,7 @@
 #define V8_COMPILER_STATE_VALUES_UTILS_H_
 
 #include <array>
+
 #include "src/common/globals.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-graph.h"
@@ -91,20 +92,23 @@ class V8_EXPORT_PRIVATE StateValuesAccess {
 
   class V8_EXPORT_PRIVATE iterator {
    public:
-    // Bare minimum of operators needed for range iteration.
-    bool operator!=(iterator const& other);
+    bool operator!=(iterator const& other) const;
     iterator& operator++();
     TypedNode operator*();
 
+    Node* node();
+    bool done() const { return current_depth_ < 0; }
+
+    // Returns the number of empty nodes that were skipped over.
+    size_t AdvanceTillNotEmpty();
+
    private:
     friend class StateValuesAccess;
 
     iterator() : current_depth_(-1) {}
     explicit iterator(Node* node);
 
-    Node* node();
     MachineType type();
-    bool done() const;
     void Advance();
     void EnsureValid();
 
@@ -119,9 +123,9 @@ class V8_EXPORT_PRIVATE StateValuesAccess {
 
   explicit StateValuesAccess(Node* node) : node_(node) {}
 
-  size_t size();
-  iterator begin() { return iterator(node_); }
-  iterator end() { return iterator(); }
+  size_t size() const;
+  iterator begin() const { return iterator(node_); }
+  iterator end() const { return iterator(); }
 
  private:
   Node* node_;
diff --git a/deps/v8/src/compiler/type-cache.h b/deps/v8/src/compiler/type-cache.h
index 3329154dbd..b71ea8455d 100644
--- a/deps/v8/src/compiler/type-cache.h
+++ b/deps/v8/src/compiler/type-cache.h
@@ -116,7 +116,7 @@ class V8_EXPORT_PRIVATE TypeCache final {
   Type const kJSArrayBufferViewByteOffsetType = kJSArrayBufferByteLengthType;
 
   // The JSTypedArray::length property always contains an untagged number in
-  // the range [0, kMaxSmiValue].
+  // the range [0, JSTypedArray::kMaxLength].
   Type const kJSTypedArrayLengthType =
       CreateRange(0.0, JSTypedArray::kMaxLength);
 
diff --git a/deps/v8/src/compiler/typed-optimization.cc b/deps/v8/src/compiler/typed-optimization.cc
index 0c81670f0b..50e2a640f6 100644
--- a/deps/v8/src/compiler/typed-optimization.cc
+++ b/deps/v8/src/compiler/typed-optimization.cc
@@ -26,9 +26,9 @@ TypedOptimization::TypedOptimization(Editor* editor,
       jsgraph_(jsgraph),
       broker_(broker),
       true_type_(
-          Type::HeapConstant(broker, factory()->true_value(), graph()->zone())),
-      false_type_(Type::HeapConstant(broker, factory()->false_value(),
-                                     graph()->zone())),
+          Type::Constant(broker, factory()->true_value(), graph()->zone())),
+      false_type_(
+          Type::Constant(broker, factory()->false_value(), graph()->zone())),
       type_cache_(TypeCache::Get()) {}
 
 TypedOptimization::~TypedOptimization() = default;
diff --git a/deps/v8/src/compiler/typer.cc b/deps/v8/src/compiler/typer.cc
index eacec94271..6d53531f1c 100644
--- a/deps/v8/src/compiler/typer.cc
+++ b/deps/v8/src/compiler/typer.cc
@@ -68,150 +68,75 @@ class Typer::Visitor : public Reducer {
 
   Reduction Reduce(Node* node) override {
     if (node->op()->ValueOutputCount() == 0) return NoChange();
-    switch (node->opcode()) {
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return UpdateType(node, TypeBinaryOp(node, x##Typer));
-      JS_SIMPLE_BINOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return UpdateType(node, Type##x(node));
-      DECLARE_CASE(Start)
-      DECLARE_CASE(IfException)
-      // VALUE_OP_LIST without JS_SIMPLE_BINOP_LIST:
-      COMMON_OP_LIST(DECLARE_CASE)
-      SIMPLIFIED_COMPARE_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_OTHER_OP_LIST(DECLARE_CASE)
-      JS_SIMPLE_UNOP_LIST(DECLARE_CASE)
-      JS_OBJECT_OP_LIST(DECLARE_CASE)
-      JS_CONTEXT_OP_LIST(DECLARE_CASE)
-      JS_OTHER_OP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return UpdateType(node, TypeBinaryOp(node, x));
-      SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_BIGINT_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return UpdateType(node, TypeUnaryOp(node, x));
-      SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_BIGINT_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_NUMBER_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) case IrOpcode::k##x:
-      DECLARE_CASE(Loop)
-      DECLARE_CASE(Branch)
-      DECLARE_CASE(IfTrue)
-      DECLARE_CASE(IfFalse)
-      DECLARE_CASE(IfSuccess)
-      DECLARE_CASE(Switch)
-      DECLARE_CASE(IfValue)
-      DECLARE_CASE(IfDefault)
-      DECLARE_CASE(Merge)
-      DECLARE_CASE(Deoptimize)
-      DECLARE_CASE(DeoptimizeIf)
-      DECLARE_CASE(DeoptimizeUnless)
-      DECLARE_CASE(TrapIf)
-      DECLARE_CASE(TrapUnless)
-      DECLARE_CASE(Return)
-      DECLARE_CASE(TailCall)
-      DECLARE_CASE(Terminate)
-      DECLARE_CASE(OsrNormalEntry)
-      DECLARE_CASE(OsrLoopEntry)
-      DECLARE_CASE(Throw)
-      DECLARE_CASE(End)
-      SIMPLIFIED_CHANGE_OP_LIST(DECLARE_CASE)
-      SIMPLIFIED_CHECKED_OP_LIST(DECLARE_CASE)
-      MACHINE_SIMD_OP_LIST(DECLARE_CASE)
-      MACHINE_OP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-      break;
-    }
-    return NoChange();
+    return UpdateType(node, TypeNode(node));
   }
 
   Type TypeNode(Node* node) {
     switch (node->opcode()) {
-#define DECLARE_CASE(x) \
-      case IrOpcode::k##x: return TypeBinaryOp(node, x##Typer);
-      JS_SIMPLE_BINOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) case IrOpcode::k##x: return Type##x(node);
-      DECLARE_CASE(Start)
-      DECLARE_CASE(IfException)
-      // VALUE_OP_LIST without JS_SIMPLE_BINOP_LIST:
-      COMMON_OP_LIST(DECLARE_CASE)
-      SIMPLIFIED_COMPARE_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_OTHER_OP_LIST(DECLARE_CASE)
-      JS_SIMPLE_UNOP_LIST(DECLARE_CASE)
-      JS_OBJECT_OP_LIST(DECLARE_CASE)
-      JS_CONTEXT_OP_LIST(DECLARE_CASE)
-      JS_OTHER_OP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return TypeBinaryOp(node, x);
-      SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_BIGINT_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) \
-  case IrOpcode::k##x:  \
-    return TypeUnaryOp(node, x);
-      SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_BIGINT_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_NUMBER_UNOP_LIST(DECLARE_CASE)
-      SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-
-#define DECLARE_CASE(x) case IrOpcode::k##x:
-      DECLARE_CASE(Loop)
-      DECLARE_CASE(Branch)
-      DECLARE_CASE(IfTrue)
-      DECLARE_CASE(IfFalse)
-      DECLARE_CASE(IfSuccess)
-      DECLARE_CASE(Switch)
-      DECLARE_CASE(IfValue)
-      DECLARE_CASE(IfDefault)
-      DECLARE_CASE(Merge)
-      DECLARE_CASE(Deoptimize)
-      DECLARE_CASE(DeoptimizeIf)
-      DECLARE_CASE(DeoptimizeUnless)
-      DECLARE_CASE(TrapIf)
-      DECLARE_CASE(TrapUnless)
-      DECLARE_CASE(Return)
-      DECLARE_CASE(TailCall)
-      DECLARE_CASE(Terminate)
-      DECLARE_CASE(OsrNormalEntry)
-      DECLARE_CASE(OsrLoopEntry)
-      DECLARE_CASE(Throw)
-      DECLARE_CASE(End)
-      SIMPLIFIED_CHANGE_OP_LIST(DECLARE_CASE)
-      SIMPLIFIED_CHECKED_OP_LIST(DECLARE_CASE)
-      MACHINE_SIMD_OP_LIST(DECLARE_CASE)
-      MACHINE_OP_LIST(DECLARE_CASE)
-#undef DECLARE_CASE
-      break;
+#define DECLARE_UNARY_CASE(x) \
+  case IrOpcode::k##x:        \
+    return Type##x(Operand(node, 0));
+      JS_SIMPLE_UNOP_LIST(DECLARE_UNARY_CASE)
+      SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_UNARY_CASE)
+      SIMPLIFIED_BIGINT_UNOP_LIST(DECLARE_UNARY_CASE)
+      SIMPLIFIED_SPECULATIVE_NUMBER_UNOP_LIST(DECLARE_UNARY_CASE)
+      SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(DECLARE_UNARY_CASE)
+#undef DECLARE_UNARY_CASE
+#define DECLARE_BINARY_CASE(x) \
+  case IrOpcode::k##x:         \
+    return Type##x(Operand(node, 0), Operand(node, 1));
+      JS_SIMPLE_BINOP_LIST(DECLARE_BINARY_CASE)
+      SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_BINARY_CASE)
+      SIMPLIFIED_BIGINT_BINOP_LIST(DECLARE_BINARY_CASE)
+      SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_BINARY_CASE)
+      SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(DECLARE_BINARY_CASE)
+#undef DECLARE_BINARY_CASE
+#define DECLARE_OTHER_CASE(x) \
+  case IrOpcode::k##x:        \
+    return Type##x(node);
+      DECLARE_OTHER_CASE(Start)
+      DECLARE_OTHER_CASE(IfException)
+      COMMON_OP_LIST(DECLARE_OTHER_CASE)
+      SIMPLIFIED_COMPARE_BINOP_LIST(DECLARE_OTHER_CASE)
+      SIMPLIFIED_OTHER_OP_LIST(DECLARE_OTHER_CASE)
+      JS_OBJECT_OP_LIST(DECLARE_OTHER_CASE)
+      JS_CONTEXT_OP_LIST(DECLARE_OTHER_CASE)
+      JS_OTHER_OP_LIST(DECLARE_OTHER_CASE)
+#undef DECLARE_OTHER_CASE
+#define DECLARE_IMPOSSIBLE_CASE(x) case IrOpcode::k##x:
+      DECLARE_IMPOSSIBLE_CASE(Loop)
+      DECLARE_IMPOSSIBLE_CASE(Branch)
+      DECLARE_IMPOSSIBLE_CASE(IfTrue)
+      DECLARE_IMPOSSIBLE_CASE(IfFalse)
+      DECLARE_IMPOSSIBLE_CASE(IfSuccess)
+      DECLARE_IMPOSSIBLE_CASE(Switch)
+      DECLARE_IMPOSSIBLE_CASE(IfValue)
+      DECLARE_IMPOSSIBLE_CASE(IfDefault)
+      DECLARE_IMPOSSIBLE_CASE(Merge)
+      DECLARE_IMPOSSIBLE_CASE(Deoptimize)
+      DECLARE_IMPOSSIBLE_CASE(DeoptimizeIf)
+      DECLARE_IMPOSSIBLE_CASE(DeoptimizeUnless)
+      DECLARE_IMPOSSIBLE_CASE(TrapIf)
+      DECLARE_IMPOSSIBLE_CASE(TrapUnless)
+      DECLARE_IMPOSSIBLE_CASE(Return)
+      DECLARE_IMPOSSIBLE_CASE(TailCall)
+      DECLARE_IMPOSSIBLE_CASE(Terminate)
+      DECLARE_IMPOSSIBLE_CASE(Throw)
+      DECLARE_IMPOSSIBLE_CASE(End)
+      SIMPLIFIED_CHANGE_OP_LIST(DECLARE_IMPOSSIBLE_CASE)
+      SIMPLIFIED_CHECKED_OP_LIST(DECLARE_IMPOSSIBLE_CASE)
+      MACHINE_SIMD_OP_LIST(DECLARE_IMPOSSIBLE_CASE)
+      MACHINE_OP_LIST(DECLARE_IMPOSSIBLE_CASE)
+#undef DECLARE_IMPOSSIBLE_CASE
+      UNREACHABLE();
     }
-    UNREACHABLE();
   }
 
   Type TypeConstant(Handle<Object> value);
 
+  bool InductionVariablePhiTypeIsPrefixedPoint(
+      InductionVariable* induction_var);
+
  private:
   Typer* typer_;
   LoopVariableOptimizer* induction_vars_;
@@ -225,7 +150,12 @@ class Typer::Visitor : public Reducer {
   COMMON_OP_LIST(DECLARE_METHOD)
   SIMPLIFIED_COMPARE_BINOP_LIST(DECLARE_METHOD)
   SIMPLIFIED_OTHER_OP_LIST(DECLARE_METHOD)
-  JS_OP_LIST(DECLARE_METHOD)
+  JS_OBJECT_OP_LIST(DECLARE_METHOD)
+  JS_CONTEXT_OP_LIST(DECLARE_METHOD)
+  JS_OTHER_OP_LIST(DECLARE_METHOD)
+#undef DECLARE_METHOD
+#define DECLARE_METHOD(x) inline Type Type##x(Type input);
+  JS_SIMPLE_UNOP_LIST(DECLARE_METHOD)
 #undef DECLARE_METHOD
 
   Type TypeOrNone(Node* node) {
@@ -251,8 +181,10 @@ class Typer::Visitor : public Reducer {
   using UnaryTyperFun = Type (*)(Type, Typer* t);
   using BinaryTyperFun = Type (*)(Type, Type, Typer* t);
 
-  Type TypeUnaryOp(Node* node, UnaryTyperFun);
-  Type TypeBinaryOp(Node* node, BinaryTyperFun);
+  inline Type TypeUnaryOp(Node* node, UnaryTyperFun);
+  inline Type TypeBinaryOp(Node* node, BinaryTyperFun);
+  inline Type TypeUnaryOp(Type input, UnaryTyperFun);
+  inline Type TypeBinaryOp(Type left, Type right, BinaryTyperFun);
 
   static Type BinaryNumberOpTyper(Type lhs, Type rhs, Typer* t,
                                   BinaryTyperFun f);
@@ -300,7 +232,28 @@ class Typer::Visitor : public Reducer {
   SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_METHOD)
   SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(DECLARE_METHOD)
 #undef DECLARE_METHOD
-
+#define DECLARE_METHOD(Name)                       \
+  inline Type Type##Name(Type left, Type right) {  \
+    return TypeBinaryOp(left, right, Name##Typer); \
+  }
+  JS_SIMPLE_BINOP_LIST(DECLARE_METHOD)
+#undef DECLARE_METHOD
+#define DECLARE_METHOD(Name)                      \
+  inline Type Type##Name(Type left, Type right) { \
+    return TypeBinaryOp(left, right, Name);       \
+  }
+  SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_BIGINT_BINOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_SPECULATIVE_BIGINT_BINOP_LIST(DECLARE_METHOD)
+#undef DECLARE_METHOD
+#define DECLARE_METHOD(Name) \
+  inline Type Type##Name(Type input) { return TypeUnaryOp(input, Name); }
+  SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_BIGINT_UNOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_SPECULATIVE_NUMBER_UNOP_LIST(DECLARE_METHOD)
+  SIMPLIFIED_SPECULATIVE_BIGINT_UNOP_LIST(DECLARE_METHOD)
+#undef DECLARE_METHOD
   static Type ObjectIsArrayBufferView(Type, Typer*);
   static Type ObjectIsBigInt(Type, Typer*);
   static Type ObjectIsCallable(Type, Typer*);
@@ -431,6 +384,14 @@ void Typer::Run(const NodeVector& roots,
   graph_reducer.ReduceGraph();
 
   if (induction_vars != nullptr) {
+    // Validate the types computed by TypeInductionVariablePhi.
+    for (auto entry : induction_vars->induction_variables()) {
+      InductionVariable* induction_var = entry.second;
+      if (induction_var->phi()->opcode() == IrOpcode::kInductionVariablePhi) {
+        CHECK(visitor.InductionVariablePhiTypeIsPrefixedPoint(induction_var));
+      }
+    }
+
     induction_vars->ChangeToPhisAndInsertGuards();
   }
 }
@@ -461,12 +422,20 @@ void Typer::Decorator::Decorate(Node* node) {
 
 Type Typer::Visitor::TypeUnaryOp(Node* node, UnaryTyperFun f) {
   Type input = Operand(node, 0);
+  return TypeUnaryOp(input, f);
+}
+
+Type Typer::Visitor::TypeUnaryOp(Type input, UnaryTyperFun f) {
   return input.IsNone() ? Type::None() : f(input, typer_);
 }
 
 Type Typer::Visitor::TypeBinaryOp(Node* node, BinaryTyperFun f) {
   Type left = Operand(node, 0);
   Type right = Operand(node, 1);
+  return TypeBinaryOp(left, right, f);
+}
+
+Type Typer::Visitor::TypeBinaryOp(Type left, Type right, BinaryTyperFun f) {
   return left.IsNone() || right.IsNone() ? Type::None()
                                          : f(left, right, typer_);
 }
@@ -561,13 +530,12 @@ Type Typer::Visitor::ToBoolean(Type type, Typer* t) {
 Type Typer::Visitor::ToInteger(Type type, Typer* t) {
   // ES6 section 7.1.4 ToInteger ( argument )
   type = ToNumber(type, t);
-  if (type.Is(t->cache_->kIntegerOrMinusZero)) return type;
+  if (type.Is(t->cache_->kInteger)) return type;
   if (type.Is(t->cache_->kIntegerOrMinusZeroOrNaN)) {
-    return Type::Union(
-        Type::Intersect(type, t->cache_->kIntegerOrMinusZero, t->zone()),
-        t->cache_->kSingletonZero, t->zone());
+    return Type::Union(Type::Intersect(type, t->cache_->kInteger, t->zone()),
+                       t->cache_->kSingletonZero, t->zone());
   }
-  return t->cache_->kIntegerOrMinusZero;
+  return t->cache_->kInteger;
 }
 
 
@@ -579,10 +547,10 @@ Type Typer::Visitor::ToLength(Type type, Typer* t) {
   double min = type.Min();
   double max = type.Max();
   if (max <= 0.0) {
-    return Type::NewConstant(0, t->zone());
+    return Type::Constant(0, t->zone());
   }
   if (min >= kMaxSafeInteger) {
-    return Type::NewConstant(kMaxSafeInteger, t->zone());
+    return Type::Constant(kMaxSafeInteger, t->zone());
   }
   if (min <= 0.0) min = 0.0;
   if (max >= kMaxSafeInteger) max = kMaxSafeInteger;
@@ -802,6 +770,8 @@ Type Typer::Visitor::TypeInt32Constant(Node* node) { UNREACHABLE(); }
 
 Type Typer::Visitor::TypeInt64Constant(Node* node) { UNREACHABLE(); }
 
+Type Typer::Visitor::TypeTaggedIndexConstant(Node* node) { UNREACHABLE(); }
+
 Type Typer::Visitor::TypeRelocatableInt32Constant(Node* node) { UNREACHABLE(); }
 
 Type Typer::Visitor::TypeRelocatableInt64Constant(Node* node) { UNREACHABLE(); }
@@ -812,7 +782,7 @@ Type Typer::Visitor::TypeFloat64Constant(Node* node) { UNREACHABLE(); }
 
 Type Typer::Visitor::TypeNumberConstant(Node* node) {
   double number = OpParameter<double>(node->op());
-  return Type::NewConstant(number, zone());
+  return Type::Constant(number, zone());
 }
 
 Type Typer::Visitor::TypeHeapConstant(Node* node) {
@@ -850,11 +820,13 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
   Type initial_type = Operand(node, 0);
   Type increment_type = Operand(node, 2);
 
-  // Fallback to normal phi typing in a variety of cases: when the induction
-  // variable is not initially of type Integer (we want to work with ranges
-  // below), when the increment is zero (in that case, phi typing will generally
-  // yield a better type), and when the induction variable can become NaN
-  // (through addition/subtraction of opposing infinities).
+  // Fallback to normal phi typing in a variety of cases:
+  // - when the induction variable is not initially of type Integer, because we
+  //   want to work with ranges in the algorithm below.
+  // - when the increment is zero, because in that case normal phi typing will
+  //   generally yield a more precise type.
+  // - when the induction variable can become NaN (through addition/subtraction
+  //   of opposing infinities), because the code below can't handle that case.
   if (initial_type.IsNone() ||
       increment_type.Is(typer_->cache_->kSingletonZero) ||
       !initial_type.Is(typer_->cache_->kInteger) ||
@@ -873,9 +845,8 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
     return type;
   }
 
-  // Now process the bounds.
   auto res = induction_vars_->induction_variables().find(node->id());
-  DCHECK(res != induction_vars_->induction_variables().end());
+  DCHECK_NE(res, induction_vars_->induction_variables().end());
   InductionVariable* induction_var = res->second;
   InductionVariable::ArithmeticType arithmetic_type = induction_var->Type();
 
@@ -888,13 +859,13 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
     increment_min = increment_type.Min();
     increment_max = increment_type.Max();
   } else {
-    DCHECK_EQ(InductionVariable::ArithmeticType::kSubtraction, arithmetic_type);
+    DCHECK_EQ(arithmetic_type, InductionVariable::ArithmeticType::kSubtraction);
     increment_min = -increment_type.Max();
     increment_max = -increment_type.Min();
   }
 
   if (increment_min >= 0) {
-    // increasing sequence
+    // Increasing sequence.
     min = initial_type.Min();
     for (auto bound : induction_var->upper_bounds()) {
       Type bound_type = TypeOrNone(bound.bound);
@@ -914,7 +885,7 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
     // The upper bound must be at least the initial value's upper bound.
     max = std::max(max, initial_type.Max());
   } else if (increment_max <= 0) {
-    // decreasing sequence
+    // Decreasing sequence.
     max = initial_type.Max();
     for (auto bound : induction_var->lower_bounds()) {
       Type bound_type = TypeOrNone(bound.bound);
@@ -935,9 +906,12 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
     min = std::min(min, initial_type.Min());
   } else {
     // If the increment can be both positive and negative, the variable can go
-    // arbitrarily far.
-    return typer_->cache_->kInteger;
+    // arbitrarily far. Use the maximal range in that case. Note that this may
+    // be less precise than what ordinary typing would produce.
+    min = -V8_INFINITY;
+    max = +V8_INFINITY;
   }
+
   if (FLAG_trace_turbo_loop) {
     StdoutStream{} << std::setprecision(10) << "Loop ("
                    << NodeProperties::GetControlInput(node)->id()
@@ -949,9 +923,68 @@ Type Typer::Visitor::TypeInductionVariablePhi(Node* node) {
                    << " for phi " << node->id() << ": (" << min << ", " << max
                    << ")\n";
   }
+
   return Type::Range(min, max, typer_->zone());
 }
 
+bool Typer::Visitor::InductionVariablePhiTypeIsPrefixedPoint(
+    InductionVariable* induction_var) {
+  Node* node = induction_var->phi();
+  DCHECK_EQ(node->opcode(), IrOpcode::kInductionVariablePhi);
+  Type type = NodeProperties::GetType(node);
+  Type initial_type = Operand(node, 0);
+  Node* arith = node->InputAt(1);
+  Type increment_type = Operand(node, 2);
+
+  // Intersect {type} with useful bounds.
+  for (auto bound : induction_var->upper_bounds()) {
+    Type bound_type = TypeOrNone(bound.bound);
+    if (!bound_type.Is(typer_->cache_->kInteger)) continue;
+    if (!bound_type.IsNone()) {
+      bound_type = Type::Range(
+          -V8_INFINITY,
+          bound_type.Max() - (bound.kind == InductionVariable::kStrict),
+          zone());
+    }
+    type = Type::Intersect(type, bound_type, typer_->zone());
+  }
+  for (auto bound : induction_var->lower_bounds()) {
+    Type bound_type = TypeOrNone(bound.bound);
+    if (!bound_type.Is(typer_->cache_->kInteger)) continue;
+    if (!bound_type.IsNone()) {
+      bound_type = Type::Range(
+          bound_type.Min() + (bound.kind == InductionVariable::kStrict),
+          +V8_INFINITY, typer_->zone());
+    }
+    type = Type::Intersect(type, bound_type, typer_->zone());
+  }
+
+  // Apply ordinary typing to the "increment" operation.
+  // clang-format off
+  switch (arith->opcode()) {
+#define CASE(x)                             \
+    case IrOpcode::k##x:                    \
+      type = Type##x(type, increment_type); \
+      break;
+    CASE(JSAdd)
+    CASE(JSSubtract)
+    CASE(NumberAdd)
+    CASE(NumberSubtract)
+    CASE(SpeculativeNumberAdd)
+    CASE(SpeculativeNumberSubtract)
+    CASE(SpeculativeSafeIntegerAdd)
+    CASE(SpeculativeSafeIntegerSubtract)
+#undef CASE
+    default:
+      UNREACHABLE();
+  }
+  // clang-format on
+
+  type = Type::Union(initial_type, type, typer_->zone());
+
+  return type.Is(NodeProperties::GetType(node));
+}
+
 Type Typer::Visitor::TypeEffectPhi(Node* node) { UNREACHABLE(); }
 
 Type Typer::Visitor::TypeLoopExit(Node* node) { UNREACHABLE(); }
@@ -1005,6 +1038,8 @@ Type Typer::Visitor::TypeTypedObjectState(Node* node) {
 
 Type Typer::Visitor::TypeCall(Node* node) { return Type::Any(); }
 
+Type Typer::Visitor::TypeFastApiCall(Node* node) { return Type::Any(); }
+
 Type Typer::Visitor::TypeProjection(Node* node) {
   Type const type = Operand(node, 0);
   if (type.Is(Type::None())) return Type::None();
@@ -1022,6 +1057,8 @@ Type Typer::Visitor::TypeTypeGuard(Node* node) {
   return typer_->operation_typer()->TypeTypeGuard(node->op(), type);
 }
 
+Type Typer::Visitor::TypeFoldConstant(Node* node) { return Operand(node, 0); }
+
 Type Typer::Visitor::TypeDead(Node* node) { return Type::None(); }
 
 Type Typer::Visitor::TypeDeadValue(Node* node) { return Type::None(); }
@@ -1042,9 +1079,10 @@ Type Typer::Visitor::JSEqualTyper(Type lhs, Type rhs, Typer* t) {
       (lhs.Max() < rhs.Min() || lhs.Min() > rhs.Max())) {
     return t->singleton_false_;
   }
-  if (lhs.IsHeapConstant() && rhs.Is(lhs)) {
+  if (lhs.IsSingleton() && rhs.Is(lhs)) {
     // Types are equal and are inhabited only by a single semantic value,
     // which is not nan due to the earlier check.
+    DCHECK(lhs.Is(rhs));
     return t->singleton_true_;
   }
   return Type::Boolean();
@@ -1190,61 +1228,33 @@ Type Typer::Visitor::JSExponentiateTyper(Type lhs, Type rhs, Typer* t) {
 
 // JS unary operators.
 
-Type Typer::Visitor::TypeJSBitwiseNot(Node* node) {
-  return TypeUnaryOp(node, BitwiseNot);
-}
-
-Type Typer::Visitor::TypeJSDecrement(Node* node) {
-  return TypeUnaryOp(node, Decrement);
-}
-
-Type Typer::Visitor::TypeJSIncrement(Node* node) {
-  return TypeUnaryOp(node, Increment);
-}
-
-Type Typer::Visitor::TypeJSNegate(Node* node) {
-  return TypeUnaryOp(node, Negate);
-}
+#define DEFINE_METHOD(Name)                       \
+  Type Typer::Visitor::TypeJS##Name(Type input) { \
+    return TypeUnaryOp(input, Name);              \
+  }
+DEFINE_METHOD(BitwiseNot)
+DEFINE_METHOD(Decrement)
+DEFINE_METHOD(Increment)
+DEFINE_METHOD(Negate)
+DEFINE_METHOD(ToLength)
+DEFINE_METHOD(ToName)
+DEFINE_METHOD(ToNumber)
+DEFINE_METHOD(ToNumberConvertBigInt)
+DEFINE_METHOD(ToNumeric)
+DEFINE_METHOD(ToObject)
+DEFINE_METHOD(ToString)
+#undef DEFINE_METHOD
 
 Type Typer::Visitor::TypeTypeOf(Node* node) {
   return Type::InternalizedString();
 }
 
-
 // JS conversion operators.
 
 Type Typer::Visitor::TypeToBoolean(Node* node) {
   return TypeUnaryOp(node, ToBoolean);
 }
 
-Type Typer::Visitor::TypeJSToLength(Node* node) {
-  return TypeUnaryOp(node, ToLength);
-}
-
-Type Typer::Visitor::TypeJSToName(Node* node) {
-  return TypeUnaryOp(node, ToName);
-}
-
-Type Typer::Visitor::TypeJSToNumber(Node* node) {
-  return TypeUnaryOp(node, ToNumber);
-}
-
-Type Typer::Visitor::TypeJSToNumberConvertBigInt(Node* node) {
-  return TypeUnaryOp(node, ToNumberConvertBigInt);
-}
-
-Type Typer::Visitor::TypeJSToNumeric(Node* node) {
-  return TypeUnaryOp(node, ToNumeric);
-}
-
-Type Typer::Visitor::TypeJSToObject(Node* node) {
-  return TypeUnaryOp(node, ToObject);
-}
-
-Type Typer::Visitor::TypeJSToString(Node* node) {
-  return TypeUnaryOp(node, ToString);
-}
-
 // JS object operators.
 
 Type Typer::Visitor::TypeJSCreate(Node* node) { return Type::Object(); }
@@ -1352,7 +1362,7 @@ Type Typer::Visitor::TypeJSLoadGlobal(Node* node) {
   return Type::NonInternal();
 }
 
-Type Typer::Visitor::TypeJSParseInt(Node* node) { return Type::Number(); }
+Type Typer::Visitor::TypeJSParseInt(Type input) { return Type::Number(); }
 
 Type Typer::Visitor::TypeJSRegExpTest(Node* node) { return Type::Boolean(); }
 
@@ -2167,6 +2177,8 @@ Type Typer::Visitor::TypeCheckNotTaggedHole(Node* node) {
   return type;
 }
 
+Type Typer::Visitor::TypeCheckClosure(Node* node) { return Type::Function(); }
+
 Type Typer::Visitor::TypeConvertReceiver(Node* node) {
   Type arg = Operand(node, 0);
   return typer_->operation_typer_.ConvertReceiver(arg);
@@ -2382,7 +2394,7 @@ Type Typer::Visitor::TypeAssertType(Node* node) { UNREACHABLE(); }
 // Heap constants.
 
 Type Typer::Visitor::TypeConstant(Handle<Object> value) {
-  return Type::NewConstant(typer_->broker(), value, zone());
+  return Type::Constant(typer_->broker(), value, zone());
 }
 
 Type Typer::Visitor::TypeJSGetIterator(Node* node) { return Type::Any(); }
diff --git a/deps/v8/src/compiler/types.cc b/deps/v8/src/compiler/types.cc
index 40adc60699..08e6e8023d 100644
--- a/deps/v8/src/compiler/types.cc
+++ b/deps/v8/src/compiler/types.cc
@@ -239,8 +239,8 @@ Type::bitset BitsetType::Lub(const MapRefLike& map) {
     case JS_MAP_VALUE_ITERATOR_TYPE:
     case JS_STRING_ITERATOR_TYPE:
     case JS_ASYNC_FROM_SYNC_ITERATOR_TYPE:
-    case JS_FINALIZATION_GROUP_TYPE:
-    case JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE:
+    case JS_FINALIZATION_REGISTRY_TYPE:
+    case JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE:
     case JS_WEAK_MAP_TYPE:
     case JS_WEAK_REF_TYPE:
     case JS_WEAK_SET_TYPE:
@@ -322,6 +322,7 @@ Type::bitset BitsetType::Lub(const MapRefLike& map) {
     case PREPARSE_DATA_TYPE:
     case UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE:
     case UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE:
+    case COVERAGE_INFO_TYPE:
       return kOtherInternal;
 
     // Remaining instance types are unsupported for now. If any of them do
@@ -368,7 +369,7 @@ Type::bitset BitsetType::Lub(const MapRefLike& map) {
     case PROMISE_REJECT_REACTION_JOB_TASK_TYPE:
     case PROMISE_RESOLVE_THENABLE_JOB_TASK_TYPE:
 #define MAKE_TORQUE_CLASS_TYPE(V) case V:
-      TORQUE_INTERNAL_INSTANCE_TYPES(MAKE_TORQUE_CLASS_TYPE)
+      TORQUE_INSTANCE_TYPES(MAKE_TORQUE_CLASS_TYPE)
 #undef MAKE_TORQUE_CLASS_TYPE
       UNREACHABLE();
   }
@@ -563,7 +564,7 @@ bool Type::SlowIs(Type that) const {
   }
 
   if (that.IsRange()) {
-    return (this->IsRange() && Contains(that.AsRange(), this->AsRange()));
+    return this->IsRange() && Contains(that.AsRange(), this->AsRange());
   }
   if (this->IsRange()) return false;
 
@@ -840,7 +841,7 @@ Type Type::NormalizeRangeAndBitset(Type range, bitset* bits, Zone* zone) {
   return Type::Range(range_min, range_max, zone);
 }
 
-Type Type::NewConstant(double value, Zone* zone) {
+Type Type::Constant(double value, Zone* zone) {
   if (RangeType::IsInteger(value)) {
     return Range(value, value, zone);
   } else if (IsMinusZero(value)) {
@@ -853,14 +854,13 @@ Type Type::NewConstant(double value, Zone* zone) {
   return OtherNumberConstant(value, zone);
 }
 
-Type Type::NewConstant(JSHeapBroker* broker, Handle<i::Object> value,
-                       Zone* zone) {
+Type Type::Constant(JSHeapBroker* broker, Handle<i::Object> value, Zone* zone) {
   ObjectRef ref(broker, value);
   if (ref.IsSmi()) {
-    return NewConstant(static_cast<double>(ref.AsSmi()), zone);
+    return Constant(static_cast<double>(ref.AsSmi()), zone);
   }
   if (ref.IsHeapNumber()) {
-    return NewConstant(ref.AsHeapNumber().value(), zone);
+    return Constant(ref.AsHeapNumber().value(), zone);
   }
   if (ref.IsString() && !ref.IsInternalizedString()) {
     return Type::String();
@@ -1093,15 +1093,12 @@ Type Type::OtherNumberConstant(double value, Zone* zone) {
 }
 
 // static
-Type Type::HeapConstant(JSHeapBroker* broker, Handle<i::Object> value,
-                        Zone* zone) {
-  return FromTypeBase(
-      HeapConstantType::New(HeapObjectRef(broker, value), zone));
-}
-
-// static
 Type Type::HeapConstant(const HeapObjectRef& value, Zone* zone) {
-  return HeapConstantType::New(value, zone);
+  DCHECK(!value.IsHeapNumber());
+  DCHECK_IMPLIES(value.IsString(), value.IsInternalizedString());
+  BitsetType::bitset bitset = BitsetType::Lub(value.GetHeapObjectType());
+  if (Type(bitset).IsSingleton()) return Type(bitset);
+  return HeapConstantType::New(value, bitset, zone);
 }
 
 // static
@@ -1114,11 +1111,6 @@ Type Type::Range(RangeType::Limits lims, Zone* zone) {
   return FromTypeBase(RangeType::New(lims, zone));
 }
 
-// static
-Type Type::Union(int length, Zone* zone) {
-  return FromTypeBase(UnionType::New(length, zone));
-}
-
 const HeapConstantType* Type::AsHeapConstant() const {
   DCHECK(IsKind(TypeBase::kHeapConstant));
   return static_cast<const HeapConstantType*>(ToTypeBase());
diff --git a/deps/v8/src/compiler/types.h b/deps/v8/src/compiler/types.h
index 0dc1aa77b0..fb1fa37d9d 100644
--- a/deps/v8/src/compiler/types.h
+++ b/deps/v8/src/compiler/types.h
@@ -191,7 +191,7 @@ namespace compiler {
   V(SymbolOrReceiver,             kSymbol | kReceiver) \
   V(StringOrReceiver,             kString | kReceiver) \
   V(Unique,                       kBoolean | kUniqueName | kNull | \
-                                  kUndefined | kReceiver) \
+                                  kUndefined | kHole | kReceiver) \
   V(Internal,                     kHole | kExternalPointer | kOtherInternal) \
   V(NonInternal,                  kPrimitive | kReceiver) \
   V(NonBigInt,                    kNonBigIntPrimitive | kReceiver) \
@@ -369,26 +369,15 @@ class V8_EXPORT_PRIVATE Type {
   static Type SignedSmall() { return NewBitset(BitsetType::SignedSmall()); }
   static Type UnsignedSmall() { return NewBitset(BitsetType::UnsignedSmall()); }
 
-  static Type OtherNumberConstant(double value, Zone* zone);
-  static Type HeapConstant(JSHeapBroker* broker, Handle<i::Object> value,
-                           Zone* zone);
-  static Type HeapConstant(const HeapObjectRef& value, Zone* zone);
+  static Type Constant(JSHeapBroker* broker, Handle<i::Object> value,
+                       Zone* zone);
+  static Type Constant(double value, Zone* zone);
   static Type Range(double min, double max, Zone* zone);
-  static Type Range(RangeType::Limits lims, Zone* zone);
   static Type Tuple(Type first, Type second, Type third, Zone* zone);
-  static Type Union(int length, Zone* zone);
-
-  // NewConstant is a factory that returns Constant, Range or Number.
-  static Type NewConstant(JSHeapBroker* broker, Handle<i::Object> value,
-                          Zone* zone);
-  static Type NewConstant(double value, Zone* zone);
 
   static Type Union(Type type1, Type type2, Zone* zone);
   static Type Intersect(Type type1, Type type2, Zone* zone);
 
-  static Type For(HeapObjectType const& type) {
-    return NewBitset(BitsetType::ExpandInternals(BitsetType::Lub(type)));
-  }
   static Type For(MapRef const& type) {
     return NewBitset(BitsetType::ExpandInternals(BitsetType::Lub(type)));
   }
@@ -412,6 +401,13 @@ class V8_EXPORT_PRIVATE Type {
   }
   bool IsTuple() const { return IsKind(TypeBase::kTuple); }
 
+  bool IsSingleton() const {
+    if (IsNone()) return false;
+    return Is(Type::Null()) || Is(Type::Undefined()) || Is(Type::MinusZero()) ||
+           Is(Type::NaN()) || Is(Type::Hole()) || IsHeapConstant() ||
+           (Is(Type::PlainNumber()) && Min() == Max());
+  }
+
   const HeapConstantType* AsHeapConstant() const;
   const OtherNumberConstantType* AsOtherNumberConstant() const;
   const RangeType* AsRange() const;
@@ -459,6 +455,7 @@ class V8_EXPORT_PRIVATE Type {
   friend size_t hash_value(Type type);
 
   explicit Type(bitset bits) : payload_(bits | 1u) {}
+
   Type(TypeBase* type_base)  // NOLINT(runtime/explicit)
       : payload_(reinterpret_cast<uintptr_t>(type_base)) {}
 
@@ -491,6 +488,10 @@ class V8_EXPORT_PRIVATE Type {
 
   static Type NewBitset(bitset bits) { return Type(bits); }
 
+  static Type Range(RangeType::Limits lims, Zone* zone);
+  static Type OtherNumberConstant(double value, Zone* zone);
+  static Type HeapConstant(const HeapObjectRef& value, Zone* zone);
+
   static bool Overlap(const RangeType* lhs, const RangeType* rhs);
   static bool Contains(const RangeType* lhs, const RangeType* rhs);
 
@@ -553,10 +554,8 @@ class V8_EXPORT_PRIVATE HeapConstantType : public NON_EXPORTED_BASE(TypeBase) {
   friend class Type;
   friend class BitsetType;
 
-  static HeapConstantType* New(const HeapObjectRef& heap_ref, Zone* zone) {
-    DCHECK(!heap_ref.IsHeapNumber());
-    DCHECK_IMPLIES(heap_ref.IsString(), heap_ref.IsInternalizedString());
-    BitsetType::bitset bitset = BitsetType::Lub(heap_ref.GetHeapObjectType());
+  static HeapConstantType* New(const HeapObjectRef& heap_ref,
+                               BitsetType::bitset bitset, Zone* zone) {
     return new (zone->New(sizeof(HeapConstantType)))
         HeapConstantType(bitset, heap_ref);
   }
diff --git a/deps/v8/src/compiler/verifier.cc b/deps/v8/src/compiler/verifier.cc
index 4384c1c066..1be87c9463 100644
--- a/deps/v8/src/compiler/verifier.cc
+++ b/deps/v8/src/compiler/verifier.cc
@@ -21,6 +21,7 @@
 #include "src/compiler/operator.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/simplified-operator.h"
+#include "src/compiler/state-values-utils.h"
 #include "src/compiler/type-cache.h"
 #include "src/utils/bit-vector.h"
 #include "src/utils/ostreams.h"
@@ -150,8 +151,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
 
   // If this node has any effect outputs, make sure that it is
   // consumed as an effect input somewhere else.
-  // TODO(mvstanton): support this kind of verification for WASM
-  // compiles, too.
+  // TODO(mvstanton): support this kind of verification for Wasm compiles, too.
   if (code_type != kWasm && node->op()->EffectOutputCount() > 0) {
     int effect_edges = 0;
     for (Edge edge : node->use_edges()) {
@@ -387,14 +387,6 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       }
       CheckNotTyped(node);
       break;
-    case IrOpcode::kOsrNormalEntry:
-    case IrOpcode::kOsrLoopEntry:
-      // Osr entries take one control and effect.
-      CHECK_EQ(1, control_count);
-      CHECK_EQ(1, effect_count);
-      CHECK_EQ(2, input_count);
-      CheckNotTyped(node);
-      break;
 
     // Common operators
     // ----------------
@@ -413,6 +405,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     }
     case IrOpcode::kInt32Constant:  // TODO(turbofan): rename Word32Constant?
     case IrOpcode::kInt64Constant:  // TODO(turbofan): rename Word64Constant?
+    case IrOpcode::kTaggedIndexConstant:
     case IrOpcode::kFloat32Constant:
     case IrOpcode::kFloat64Constant:
     case IrOpcode::kRelocatableInt32Constant:
@@ -550,11 +543,34 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
               NodeProperties::GetValueInput(node, i)->opcode() ==
                   IrOpcode::kTypedStateValues);
       }
-      // The accumulator (InputAt(2)) cannot be kStateValues, but it can be
-      // kTypedStateValues (to signal the type). Once AST graph builder
-      // is removed, we should check this here. Until then, AST graph
-      // builder can generate expression stack as InputAt(2), which can
-      // still be kStateValues.
+
+      // Checks that the state input is empty for all but kInterpretedFunction
+      // frames, where it should have size one.
+      {
+        const FrameStateInfo& state_info = FrameStateInfoOf(node->op());
+        const FrameStateFunctionInfo* func_info = state_info.function_info();
+        CHECK_EQ(func_info->parameter_count(),
+                 StateValuesAccess(node->InputAt(kFrameStateParametersInput))
+                     .size());
+        CHECK_EQ(
+            func_info->local_count(),
+            StateValuesAccess(node->InputAt(kFrameStateLocalsInput)).size());
+
+        Node* accumulator = node->InputAt(kFrameStateStackInput);
+        if (func_info->type() == FrameStateType::kInterpretedFunction) {
+          // The accumulator (InputAt(2)) cannot be kStateValues.
+          // It can be kTypedStateValues (to signal the type) and it can have
+          // other Node types including that of the optimized_out HeapConstant.
+          CHECK_NE(accumulator->opcode(), IrOpcode::kStateValues);
+          if (accumulator->opcode() == IrOpcode::kTypedStateValues) {
+            CHECK_EQ(1, StateValuesAccess(accumulator).size());
+          }
+        } else {
+          CHECK(accumulator->opcode() == IrOpcode::kTypedStateValues ||
+                accumulator->opcode() == IrOpcode::kStateValues);
+          CHECK_EQ(0, StateValuesAccess(accumulator).size());
+        }
+      }
       break;
     }
     case IrOpcode::kObjectId:
@@ -1394,6 +1410,11 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       CheckValueInputIs(node, 0, Type::Unsigned32());
       CheckTypeIs(node, Type::Unsigned32());
       break;
+    case IrOpcode::kCheckClosure:
+      // Any -> Function
+      CheckValueInputIs(node, 0, Type::Any());
+      CheckTypeIs(node, Type::Function());
+      break;
     case IrOpcode::kCheckHeapObject:
       CheckValueInputIs(node, 0, Type::Any());
       break;
@@ -1505,7 +1526,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // Object -> fieldtype
       // TODO(rossberg): activate once machine ops are typed.
       // CheckValueInputIs(node, 0, Type::Object());
-      // CheckTypeIs(node, FieldAccessOf(node->op()).type));
+      // CheckTypeIs(node, FieldAccessOf(node->op()).type);
       break;
     case IrOpcode::kLoadElement:
     case IrOpcode::kLoadStackArgument:
@@ -1515,7 +1536,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       // CheckTypeIs(node, ElementAccessOf(node->op()).type));
       break;
     case IrOpcode::kLoadFromObject:
-      // TODO(gsps): Can we check some types here?
+      CheckValueInputIs(node, 0, Type::Receiver());
       break;
     case IrOpcode::kLoadTypedElement:
       break;
@@ -1567,6 +1588,14 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
     case IrOpcode::kTypeGuard:
       CheckTypeIs(node, TypeGuardTypeOf(node->op()));
       break;
+    case IrOpcode::kFoldConstant:
+      if (typing == TYPED) {
+        Type type = NodeProperties::GetType(node);
+        CHECK(type.IsSingleton());
+        CHECK(type.Equals(NodeProperties::GetType(node->InputAt(0))));
+        CHECK(type.Equals(NodeProperties::GetType(node->InputAt(1))));
+      }
+      break;
     case IrOpcode::kDateNow:
       CHECK_EQ(0, value_count);
       CheckTypeIs(node, Type::Number());
@@ -1575,6 +1604,10 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       CheckValueInputIs(node, 0, Type::Any());
       CheckTypeIs(node, Type::BigInt());
       break;
+    case IrOpcode::kFastApiCall:
+      CHECK_GE(value_count, 1);
+      CheckValueInputIs(node, 0, Type::ExternalPointer());
+      break;
 
     // Machine operators
     // -----------------------
diff --git a/deps/v8/src/compiler/wasm-compiler.cc b/deps/v8/src/compiler/wasm-compiler.cc
index db1731f388..9373a2b4b9 100644
--- a/deps/v8/src/compiler/wasm-compiler.cc
+++ b/deps/v8/src/compiler/wasm-compiler.cc
@@ -62,13 +62,6 @@ namespace compiler {
 
 namespace {
 
-// TODO(titzer): pull WASM_64 up to a common header.
-#if !V8_TARGET_ARCH_32_BIT || V8_TARGET_ARCH_X64
-#define WASM_64 1
-#else
-#define WASM_64 0
-#endif
-
 #define FATAL_UNSUPPORTED_OPCODE(opcode)        \
   FATAL("Unsupported opcode 0x%x:%s", (opcode), \
         wasm::WasmOpcodes::OpcodeName(opcode));
@@ -85,28 +78,22 @@ MachineType assert_size(int expected_size, MachineType type) {
 #define WASM_INSTANCE_OBJECT_OFFSET(name) \
   wasm::ObjectAccess::ToTagged(WasmInstanceObject::k##name##Offset)
 
-#define LOAD_RAW(base_pointer, byte_offset, type)                             \
-  SetEffect(graph()->NewNode(mcgraph()->machine()->Load(type), base_pointer,  \
-                             mcgraph()->Int32Constant(byte_offset), effect(), \
-                             control()))
-
-#define LOAD_RAW_NODE_OFFSET(base_pointer, node_offset, type)                \
-  SetEffect(graph()->NewNode(mcgraph()->machine()->Load(type), base_pointer, \
-                             node_offset, effect(), control()))
+#define LOAD_INSTANCE_FIELD(name, type)                           \
+  gasm_->Load(assert_size(WASM_INSTANCE_OBJECT_SIZE(name), type), \
+              instance_node_.get(), WASM_INSTANCE_OBJECT_OFFSET(name))
 
-#define LOAD_INSTANCE_FIELD(name, type)                             \
-  LOAD_RAW(instance_node_.get(), WASM_INSTANCE_OBJECT_OFFSET(name), \
-           assert_size(WASM_INSTANCE_OBJECT_SIZE(name), type))
+#define LOAD_FULL_POINTER(base_pointer, byte_offset) \
+  gasm_->Load(MachineType::Pointer(), base_pointer, byte_offset)
 
 #define LOAD_TAGGED_POINTER(base_pointer, byte_offset) \
-  LOAD_RAW(base_pointer, byte_offset, MachineType::TaggedPointer())
+  gasm_->Load(MachineType::TaggedPointer(), base_pointer, byte_offset)
 
 #define LOAD_TAGGED_ANY(base_pointer, byte_offset) \
-  LOAD_RAW(base_pointer, byte_offset, MachineType::AnyTagged())
+  gasm_->Load(MachineType::AnyTagged(), base_pointer, byte_offset)
 
 #define LOAD_FIXED_ARRAY_SLOT(array_node, index, type) \
-  LOAD_RAW(array_node,                                 \
-           wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(index), type)
+  gasm_->Load(type, array_node,                        \
+              wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(index))
 
 #define LOAD_FIXED_ARRAY_SLOT_SMI(array_node, index) \
   LOAD_FIXED_ARRAY_SLOT(array_node, index, MachineType::TaggedSigned())
@@ -117,15 +104,11 @@ MachineType assert_size(int expected_size, MachineType type) {
 #define LOAD_FIXED_ARRAY_SLOT_ANY(array_node, index) \
   LOAD_FIXED_ARRAY_SLOT(array_node, index, MachineType::AnyTagged())
 
-#define STORE_RAW(base, offset, val, rep, barrier)                          \
-  SetEffect(graph()->NewNode(                                               \
-      mcgraph()->machine()->Store(StoreRepresentation(rep, barrier)), base, \
-      mcgraph()->Int32Constant(offset), val, effect(), control()))
+#define STORE_RAW(base, offset, val, rep, barrier) \
+  STORE_RAW_NODE_OFFSET(base, gasm_->Int32Constant(offset), val, rep, barrier)
 
-#define STORE_RAW_NODE_OFFSET(base, node_offset, val, rep, barrier)         \
-  SetEffect(graph()->NewNode(                                               \
-      mcgraph()->machine()->Store(StoreRepresentation(rep, barrier)), base, \
-      node_offset, val, effect(), control()))
+#define STORE_RAW_NODE_OFFSET(base, node_offset, val, rep, barrier) \
+  gasm_->Store(StoreRepresentation(rep, barrier), base, node_offset, val)
 
 // This can be used to store tagged Smi values only.
 #define STORE_FIXED_ARRAY_SLOT_SMI(array_node, index, value)                   \
@@ -148,14 +131,14 @@ void MergeControlToEnd(MachineGraph* mcgraph, Node* node) {
   }
 }
 
-bool ContainsSimd(wasm::FunctionSig* sig) {
+bool ContainsSimd(const wasm::FunctionSig* sig) {
   for (auto type : sig->all()) {
     if (type == wasm::kWasmS128) return true;
   }
   return false;
 }
 
-bool ContainsInt64(wasm::FunctionSig* sig) {
+bool ContainsInt64(const wasm::FunctionSig* sig) {
   for (auto type : sig->all()) {
     if (type == wasm::kWasmI64) return true;
   }
@@ -171,7 +154,7 @@ class WasmGraphAssembler : public GraphAssembler {
 
 WasmGraphBuilder::WasmGraphBuilder(
     wasm::CompilationEnv* env, Zone* zone, MachineGraph* mcgraph,
-    wasm::FunctionSig* sig,
+    const wasm::FunctionSig* sig,
     compiler::SourcePositionTable* source_position_table)
     : gasm_(std::make_unique<WasmGraphAssembler>(mcgraph, zone)),
       zone_(zone),
@@ -262,9 +245,8 @@ Node* WasmGraphBuilder::Phi(wasm::ValueType type, unsigned count,
                             Node** vals_and_control) {
   DCHECK(IrOpcode::IsMergeOpcode(vals_and_control[count]->opcode()));
   return graph()->NewNode(
-      mcgraph()->common()->Phi(wasm::ValueTypes::MachineRepresentationFor(type),
-                               count),
-      count + 1, vals_and_control);
+      mcgraph()->common()->Phi(type.machine_representation(), count), count + 1,
+      vals_and_control);
 }
 
 Node* WasmGraphBuilder::EffectPhi(unsigned count, Node** effects_and_control) {
@@ -275,7 +257,7 @@ Node* WasmGraphBuilder::EffectPhi(unsigned count, Node** effects_and_control) {
 
 Node* WasmGraphBuilder::RefNull() {
   Node* isolate_root = BuildLoadIsolateRoot();
-  return LOAD_TAGGED_POINTER(
+  return LOAD_FULL_POINTER(
       isolate_root, IsolateData::root_slot_offset(RootIndex::kNullValue));
 }
 
@@ -1148,26 +1130,26 @@ Node* WasmGraphBuilder::BuildChangeEndiannessStore(
   Node* result;
   Node* value = node;
   MachineOperatorBuilder* m = mcgraph()->machine();
-  int valueSizeInBytes = wasm::ValueTypes::ElementSizeInBytes(wasmtype);
+  int valueSizeInBytes = wasmtype.element_size_bytes();
   int valueSizeInBits = 8 * valueSizeInBytes;
   bool isFloat = false;
 
-  switch (wasmtype) {
-    case wasm::kWasmF64:
+  switch (wasmtype.kind()) {
+    case wasm::ValueType::kF64:
       value = graph()->NewNode(m->BitcastFloat64ToInt64(), node);
       isFloat = true;
       V8_FALLTHROUGH;
-    case wasm::kWasmI64:
+    case wasm::ValueType::kI64:
       result = mcgraph()->Int64Constant(0);
       break;
-    case wasm::kWasmF32:
+    case wasm::ValueType::kF32:
       value = graph()->NewNode(m->BitcastFloat32ToInt32(), node);
       isFloat = true;
       V8_FALLTHROUGH;
-    case wasm::kWasmI32:
+    case wasm::ValueType::kI32:
       result = mcgraph()->Int32Constant(0);
       break;
-    case wasm::kWasmS128:
+    case wasm::ValueType::kS128:
       DCHECK(ReverseBytesSupported(m, valueSizeInBytes));
       break;
     default:
@@ -1182,7 +1164,7 @@ Node* WasmGraphBuilder::BuildChangeEndiannessStore(
     // In case we store lower part of WasmI64 expression, we can truncate
     // upper 32bits
     value = graph()->NewNode(m->TruncateInt64ToInt32(), value);
-    valueSizeInBytes = wasm::ValueTypes::ElementSizeInBytes(wasm::kWasmI32);
+    valueSizeInBytes = wasm::kWasmI32.element_size_bytes();
     valueSizeInBits = 8 * valueSizeInBytes;
     if (mem_rep == MachineRepresentation::kWord16) {
       value =
@@ -1256,11 +1238,11 @@ Node* WasmGraphBuilder::BuildChangeEndiannessStore(
   }
 
   if (isFloat) {
-    switch (wasmtype) {
-      case wasm::kWasmF64:
+    switch (wasmtype.kind()) {
+      case wasm::ValueType::kF64:
         result = graph()->NewNode(m->BitcastInt64ToFloat64(), result);
         break;
-      case wasm::kWasmF32:
+      case wasm::ValueType::kF32:
         result = graph()->NewNode(m->BitcastInt32ToFloat32(), result);
         break;
       default:
@@ -1431,31 +1413,24 @@ Node* WasmGraphBuilder::BuildF32CopySign(Node* left, Node* right) {
 }
 
 Node* WasmGraphBuilder::BuildF64CopySign(Node* left, Node* right) {
-#if WASM_64
-  Node* result = Unop(
-      wasm::kExprF64ReinterpretI64,
-      Binop(wasm::kExprI64Ior,
-            Binop(wasm::kExprI64And, Unop(wasm::kExprI64ReinterpretF64, left),
-                  mcgraph()->Int64Constant(0x7FFFFFFFFFFFFFFF)),
-            Binop(wasm::kExprI64And, Unop(wasm::kExprI64ReinterpretF64, right),
-                  mcgraph()->Int64Constant(0x8000000000000000))));
+  if (mcgraph()->machine()->Is64()) {
+    return gasm_->BitcastInt64ToFloat64(gasm_->Word64Or(
+        gasm_->Word64And(gasm_->BitcastFloat64ToInt64(left),
+                         gasm_->Int64Constant(0x7FFFFFFFFFFFFFFF)),
+        gasm_->Word64And(gasm_->BitcastFloat64ToInt64(right),
+                         gasm_->Int64Constant(0x8000000000000000))));
+  }
 
-  return result;
-#else
-  MachineOperatorBuilder* m = mcgraph()->machine();
+  DCHECK(mcgraph()->machine()->Is32());
 
-  Node* high_word_left = graph()->NewNode(m->Float64ExtractHighWord32(), left);
-  Node* high_word_right =
-      graph()->NewNode(m->Float64ExtractHighWord32(), right);
+  Node* high_word_left = gasm_->Float64ExtractHighWord32(left);
+  Node* high_word_right = gasm_->Float64ExtractHighWord32(right);
 
-  Node* new_high_word = Binop(wasm::kExprI32Ior,
-                              Binop(wasm::kExprI32And, high_word_left,
-                                    mcgraph()->Int32Constant(0x7FFFFFFF)),
-                              Binop(wasm::kExprI32And, high_word_right,
-                                    mcgraph()->Int32Constant(0x80000000)));
+  Node* new_high_word = gasm_->Word32Or(
+      gasm_->Word32And(high_word_left, gasm_->Int32Constant(0x7FFFFFFF)),
+      gasm_->Word32And(high_word_right, gasm_->Int32Constant(0x80000000)));
 
-  return graph()->NewNode(m->Float64InsertHighWord32(), left, new_high_word);
-#endif
+  return gasm_->Float64InsertHighWord32(left, new_high_word);
 }
 
 namespace {
@@ -1763,14 +1738,7 @@ Node* WasmGraphBuilder::BuildI32AsmjsUConvertF64(Node* input) {
 
 Node* WasmGraphBuilder::BuildBitCountingCall(Node* input, ExternalReference ref,
                                              MachineRepresentation input_type) {
-  Node* stack_slot_param =
-      graph()->NewNode(mcgraph()->machine()->StackSlot(input_type));
-
-  const Operator* store_op = mcgraph()->machine()->Store(
-      StoreRepresentation(input_type, kNoWriteBarrier));
-  SetEffect(graph()->NewNode(store_op, stack_slot_param,
-                             mcgraph()->Int32Constant(0), input, effect(),
-                             control()));
+  Node* stack_slot_param = StoreArgsInStackSlot({{input_type, input}});
 
   MachineType sig_types[] = {MachineType::Int32(), MachineType::Pointer()};
   MachineSignature sig(1, 1, sig_types);
@@ -1885,27 +1853,17 @@ Node* WasmGraphBuilder::BuildCFuncInstruction(ExternalReference ref,
   // parameters in this buffer slots, pass a pointer to the buffer to the C
   // function, and after calling the C function we collect the return value from
   // the buffer.
-
-  const int type_size = ElementSizeInBytes(type.representation());
-  const int stack_slot_bytes = (input1 == nullptr ? 1 : 2) * type_size;
-  Node* stack_slot =
-      graph()->NewNode(mcgraph()->machine()->StackSlot(stack_slot_bytes));
-
-  const Operator* store_op = mcgraph()->machine()->Store(
-      StoreRepresentation(type.representation(), kNoWriteBarrier));
-  SetEffect(graph()->NewNode(store_op, stack_slot, mcgraph()->Int32Constant(0),
-                             input0, effect(), control()));
-
-  Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(ref));
-
-  if (input1 != nullptr) {
-    SetEffect(graph()->NewNode(store_op, stack_slot,
-                               mcgraph()->Int32Constant(type_size), input1,
-                               effect(), control()));
+  Node* stack_slot;
+  if (input1) {
+    stack_slot = StoreArgsInStackSlot(
+        {{type.representation(), input0}, {type.representation(), input1}});
+  } else {
+    stack_slot = StoreArgsInStackSlot({{type.representation(), input0}});
   }
 
   MachineType sig_types[] = {MachineType::Pointer()};
   MachineSignature sig(0, 1, sig_types);
+  Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(ref));
   BuildCCall(&sig, function, stack_slot);
 
   return SetEffect(graph()->NewNode(mcgraph()->machine()->Load(type),
@@ -2066,17 +2024,17 @@ Node* WasmGraphBuilder::Throw(uint32_t exception_index,
   MachineOperatorBuilder* m = mcgraph()->machine();
   for (size_t i = 0; i < sig->parameter_count(); ++i) {
     Node* value = values[i];
-    switch (sig->GetParam(i)) {
-      case wasm::kWasmF32:
+    switch (sig->GetParam(i).kind()) {
+      case wasm::ValueType::kF32:
         value = graph()->NewNode(m->BitcastFloat32ToInt32(), value);
         V8_FALLTHROUGH;
-      case wasm::kWasmI32:
+      case wasm::ValueType::kI32:
         BuildEncodeException32BitValue(values_array, &index, value);
         break;
-      case wasm::kWasmF64:
+      case wasm::ValueType::kF64:
         value = graph()->NewNode(m->BitcastFloat64ToInt64(), value);
         V8_FALLTHROUGH;
-      case wasm::kWasmI64: {
+      case wasm::ValueType::kI64: {
         Node* upper32 = graph()->NewNode(
             m->TruncateInt64ToInt32(),
             Binop(wasm::kExprI64ShrU, value, Int64Constant(32)));
@@ -2085,7 +2043,7 @@ Node* WasmGraphBuilder::Throw(uint32_t exception_index,
         BuildEncodeException32BitValue(values_array, &index, lower32);
         break;
       }
-      case wasm::kWasmS128:
+      case wasm::ValueType::kS128:
         BuildEncodeException32BitValue(
             values_array, &index,
             graph()->NewNode(m->I32x4ExtractLane(0), value));
@@ -2099,14 +2057,15 @@ Node* WasmGraphBuilder::Throw(uint32_t exception_index,
             values_array, &index,
             graph()->NewNode(m->I32x4ExtractLane(3), value));
         break;
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef:
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef:
         STORE_FIXED_ARRAY_SLOT_ANY(values_array, index, value);
         ++index;
         break;
-      default:
+      case wasm::ValueType::kStmt:
+      case wasm::ValueType::kBottom:
         UNREACHABLE();
     }
   }
@@ -2165,7 +2124,6 @@ Node* WasmGraphBuilder::BuildDecodeException64BitValue(Node* values_array,
 }
 
 Node* WasmGraphBuilder::Rethrow(Node* except_obj) {
-  needs_stack_check_ = true;
   // TODO(v8:8091): Currently the message of the original exception is not being
   // preserved when rethrown to the console. The pending message will need to be
   // saved when caught and restored here while being rethrown.
@@ -2176,9 +2134,7 @@ Node* WasmGraphBuilder::Rethrow(Node* except_obj) {
       Operator::kNoProperties, StubCallMode::kCallWasmRuntimeStub);
   Node* call_target = mcgraph()->RelocatableIntPtrConstant(
       wasm::WasmCode::kWasmRethrow, RelocInfo::WASM_STUB_CALL);
-  return SetEffectControl(
-      graph()->NewNode(mcgraph()->common()->Call(call_descriptor), call_target,
-                       except_obj, effect(), control()));
+  return gasm_->Call(call_descriptor, call_target, except_obj);
 }
 
 Node* WasmGraphBuilder::ExceptionTagEqual(Node* caught_tag,
@@ -2194,8 +2150,10 @@ Node* WasmGraphBuilder::LoadExceptionTagFromTable(uint32_t exception_index) {
   return tag;
 }
 
-Node* WasmGraphBuilder::GetExceptionTag(Node* except_obj) {
-  needs_stack_check_ = true;
+Node* WasmGraphBuilder::GetExceptionTag(Node* except_obj,
+                                        wasm::WasmCodePosition position) {
+  TrapIfTrue(wasm::kTrapBrOnExnNullRef, gasm_->WordEqual(RefNull(), except_obj),
+             position);
   return BuildCallToRuntime(Runtime::kWasmExceptionGetTag, &except_obj, 1);
 }
 
@@ -2209,24 +2167,24 @@ Node* WasmGraphBuilder::GetExceptionValues(Node* except_obj,
   DCHECK_EQ(sig->parameter_count(), values.size());
   for (size_t i = 0; i < sig->parameter_count(); ++i) {
     Node* value;
-    switch (sig->GetParam(i)) {
-      case wasm::kWasmI32:
+    switch (sig->GetParam(i).kind()) {
+      case wasm::ValueType::kI32:
         value = BuildDecodeException32BitValue(values_array, &index);
         break;
-      case wasm::kWasmI64:
+      case wasm::ValueType::kI64:
         value = BuildDecodeException64BitValue(values_array, &index);
         break;
-      case wasm::kWasmF32: {
+      case wasm::ValueType::kF32: {
         value = Unop(wasm::kExprF32ReinterpretI32,
                      BuildDecodeException32BitValue(values_array, &index));
         break;
       }
-      case wasm::kWasmF64: {
+      case wasm::ValueType::kF64: {
         value = Unop(wasm::kExprF64ReinterpretI64,
                      BuildDecodeException64BitValue(values_array, &index));
         break;
       }
-      case wasm::kWasmS128:
+      case wasm::ValueType::kS128:
         value = graph()->NewNode(
             mcgraph()->machine()->I32x4Splat(),
             BuildDecodeException32BitValue(values_array, &index));
@@ -2240,14 +2198,15 @@ Node* WasmGraphBuilder::GetExceptionValues(Node* except_obj,
             mcgraph()->machine()->I32x4ReplaceLane(3), value,
             BuildDecodeException32BitValue(values_array, &index));
         break;
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef:
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef:
         value = LOAD_FIXED_ARRAY_SLOT_ANY(values_array, index);
         ++index;
         break;
-      default:
+      case wasm::ValueType::kStmt:
+      case wasm::ValueType::kBottom:
         UNREACHABLE();
     }
     values[i] = value;
@@ -2551,15 +2510,8 @@ Node* WasmGraphBuilder::BuildDiv64Call(Node* left, Node* right,
                                        wasm::TrapReason trap_zero,
                                        wasm::WasmCodePosition position) {
   Node* stack_slot =
-      graph()->NewNode(mcgraph()->machine()->StackSlot(2 * sizeof(double)));
-
-  const Operator* store_op = mcgraph()->machine()->Store(
-      StoreRepresentation(MachineRepresentation::kWord64, kNoWriteBarrier));
-  SetEffect(graph()->NewNode(store_op, stack_slot, mcgraph()->Int32Constant(0),
-                             left, effect(), control()));
-  SetEffect(graph()->NewNode(store_op, stack_slot,
-                             mcgraph()->Int32Constant(sizeof(double)), right,
-                             effect(), control()));
+      StoreArgsInStackSlot({{MachineRepresentation::kWord64, left},
+                            {MachineRepresentation::kWord64, right}});
 
   MachineType sig_types[] = {MachineType::Int32(), MachineType::Pointer()};
   MachineSignature sig(1, 1, sig_types);
@@ -2588,7 +2540,7 @@ Node* WasmGraphBuilder::BuildCCall(MachineSignature* sig, Node* function,
   return SetEffect(graph()->NewNode(op, arraysize(call_args), call_args));
 }
 
-Node* WasmGraphBuilder::BuildCallNode(wasm::FunctionSig* sig,
+Node* WasmGraphBuilder::BuildCallNode(const wasm::FunctionSig* sig,
                                       Vector<Node*> args,
                                       wasm::WasmCodePosition position,
                                       Node* instance_node, const Operator* op) {
@@ -2623,7 +2575,7 @@ Node* WasmGraphBuilder::BuildCallNode(wasm::FunctionSig* sig,
   return call;
 }
 
-Node* WasmGraphBuilder::BuildWasmCall(wasm::FunctionSig* sig,
+Node* WasmGraphBuilder::BuildWasmCall(const wasm::FunctionSig* sig,
                                       Vector<Node*> args, Vector<Node*> rets,
                                       wasm::WasmCodePosition position,
                                       Node* instance_node,
@@ -2650,7 +2602,7 @@ Node* WasmGraphBuilder::BuildWasmCall(wasm::FunctionSig* sig,
   return call;
 }
 
-Node* WasmGraphBuilder::BuildWasmReturnCall(wasm::FunctionSig* sig,
+Node* WasmGraphBuilder::BuildWasmReturnCall(const wasm::FunctionSig* sig,
                                             Vector<Node*> args,
                                             wasm::WasmCodePosition position,
                                             Node* instance_node,
@@ -2665,7 +2617,7 @@ Node* WasmGraphBuilder::BuildWasmReturnCall(wasm::FunctionSig* sig,
   return call;
 }
 
-Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig,
+Node* WasmGraphBuilder::BuildImportCall(const wasm::FunctionSig* sig,
                                         Vector<Node*> args, Vector<Node*> rets,
                                         wasm::WasmCodePosition position,
                                         int func_index,
@@ -2696,7 +2648,7 @@ Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig,
   }
 }
 
-Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig,
+Node* WasmGraphBuilder::BuildImportCall(const wasm::FunctionSig* sig,
                                         Vector<Node*> args, Vector<Node*> rets,
                                         wasm::WasmCodePosition position,
                                         Node* func_index,
@@ -2712,9 +2664,9 @@ Node* WasmGraphBuilder::BuildImportCall(wasm::FunctionSig* sig,
   Node* func_index_times_tagged_size = graph()->NewNode(
       mcgraph()->machine()->IntMul(), Uint32ToUintptr(func_index),
       mcgraph()->Int32Constant(kTaggedSize));
-  Node* ref_node = LOAD_RAW_NODE_OFFSET(imported_instances_data,
-                                        func_index_times_tagged_size,
-                                        MachineType::TaggedPointer());
+  Node* ref_node =
+      gasm_->Load(MachineType::TaggedPointer(), imported_instances_data,
+                  func_index_times_tagged_size);
 
   // Load the target from the imported_targets array at the offset of
   // {func_index}.
@@ -2750,7 +2702,7 @@ Node* WasmGraphBuilder::CallDirect(uint32_t index, Vector<Node*> args,
                                    Vector<Node*> rets,
                                    wasm::WasmCodePosition position) {
   DCHECK_NULL(args[0]);
-  wasm::FunctionSig* sig = env_->module->functions[index].sig;
+  const wasm::FunctionSig* sig = env_->module->functions[index].sig;
 
   if (env_ && index < env_->module->num_imported_functions) {
     // Call to an imported function.
@@ -2793,25 +2745,21 @@ void WasmGraphBuilder::LoadIndirectFunctionTable(uint32_t table_index,
       LOAD_INSTANCE_FIELD(IndirectFunctionTables, MachineType::TaggedPointer());
   Node* ift_table = LOAD_FIXED_ARRAY_SLOT_ANY(ift_tables, table_index);
 
-  *ift_size = LOAD_RAW(
-      ift_table,
-      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kSizeOffset),
-      MachineType::Int32());
+  *ift_size = gasm_->Load(
+      MachineType::Int32(), ift_table,
+      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kSizeOffset));
 
-  *ift_sig_ids = LOAD_RAW(
-      ift_table,
-      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kSigIdsOffset),
-      MachineType::Pointer());
+  *ift_sig_ids = gasm_->Load(
+      MachineType::Pointer(), ift_table,
+      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kSigIdsOffset));
 
-  *ift_targets = LOAD_RAW(
-      ift_table,
-      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kTargetsOffset),
-      MachineType::Pointer());
+  *ift_targets = gasm_->Load(
+      MachineType::Pointer(), ift_table,
+      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kTargetsOffset));
 
-  *ift_instances = LOAD_RAW(
-      ift_table,
-      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kRefsOffset),
-      MachineType::TaggedPointer());
+  *ift_instances = gasm_->Load(
+      MachineType::TaggedPointer(), ift_table,
+      wasm::ObjectAccess::ToTagged(WasmIndirectFunctionTable::kRefsOffset));
 }
 
 Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
@@ -2831,7 +2779,7 @@ Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
   LoadIndirectFunctionTable(table_index, &ift_size, &ift_sig_ids, &ift_targets,
                             &ift_instances);
 
-  wasm::FunctionSig* sig = env_->module->signatures[sig_index];
+  const wasm::FunctionSig* sig = env_->module->signatures[sig_index];
 
   MachineOperatorBuilder* machine = mcgraph()->machine();
   Node* key = args[0];
@@ -2875,10 +2823,10 @@ Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
                                          int32_scaled_key);
   }
 
-  Node* target_instance = LOAD_RAW(
+  Node* target_instance = gasm_->Load(
+      MachineType::TaggedPointer(),
       graph()->NewNode(machine->IntAdd(), ift_instances, tagged_scaled_key),
-      wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0),
-      MachineType::TaggedPointer());
+      wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(0));
 
   Node* intptr_scaled_key;
   if (kSystemPointerSize == kTaggedSize) {
@@ -2910,7 +2858,7 @@ Node* WasmGraphBuilder::BuildIndirectCall(uint32_t table_index,
 Node* WasmGraphBuilder::ReturnCall(uint32_t index, Vector<Node*> args,
                                    wasm::WasmCodePosition position) {
   DCHECK_NULL(args[0]);
-  wasm::FunctionSig* sig = env_->module->functions[index].sig;
+  const wasm::FunctionSig* sig = env_->module->functions[index].sig;
 
   if (env_ && index < env_->module->num_imported_functions) {
     // Return Call to an imported function.
@@ -2991,6 +2939,7 @@ Node* WasmGraphBuilder::BuildChangeInt32ToIntPtr(Node* value) {
 }
 
 Node* WasmGraphBuilder::BuildChangeInt32ToSmi(Node* value) {
+  // With pointer compression, only the lower 32 bits are used.
   if (COMPRESS_POINTERS_BOOL) {
     return graph()->NewNode(mcgraph()->machine()->Word32Shl(), value,
                             BuildSmiShiftBitsConstant32());
@@ -3299,7 +3248,7 @@ Node* WasmGraphBuilder::BuildCallToRuntimeWithContext(Runtime::FunctionId f,
   DCHECK_EQ(1, fun->result_size);
   auto centry_id =
       Builtins::kCEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit;
-  Node* centry_stub = LOAD_TAGGED_POINTER(
+  Node* centry_stub = LOAD_FULL_POINTER(
       isolate_root, IsolateData::builtin_slot_offset(centry_id));
   // TODO(titzer): allow arbitrary number of runtime arguments
   // At the moment we only allow 5 parameters. If more parameters are needed,
@@ -3334,39 +3283,36 @@ Node* WasmGraphBuilder::BuildCallToRuntime(Runtime::FunctionId f,
 
 Node* WasmGraphBuilder::GlobalGet(uint32_t index) {
   const wasm::WasmGlobal& global = env_->module->globals[index];
-  if (wasm::ValueTypes::IsReferenceType(global.type)) {
+  if (global.type.IsReferenceType()) {
     if (global.mutability && global.imported) {
       Node* base = nullptr;
       Node* offset = nullptr;
       GetBaseAndOffsetForImportedMutableAnyRefGlobal(global, &base, &offset);
-      return LOAD_RAW_NODE_OFFSET(base, offset, MachineType::AnyTagged());
+      return gasm_->Load(MachineType::AnyTagged(), base, offset);
     }
     Node* globals_buffer =
         LOAD_INSTANCE_FIELD(TaggedGlobalsBuffer, MachineType::TaggedPointer());
     return LOAD_FIXED_ARRAY_SLOT_ANY(globals_buffer, global.offset);
   }
 
-  MachineType mem_type =
-      wasm::ValueTypes::MachineTypeFor(env_->module->globals[index].type);
+  MachineType mem_type = global.type.machine_type();
   if (mem_type.representation() == MachineRepresentation::kSimd128) {
     has_simd_ = true;
   }
   Node* base = nullptr;
   Node* offset = nullptr;
-  GetGlobalBaseAndOffset(mem_type, env_->module->globals[index], &base,
-                         &offset);
+  GetGlobalBaseAndOffset(mem_type, global, &base, &offset);
   Node* result = SetEffect(graph()->NewNode(
       mcgraph()->machine()->Load(mem_type), base, offset, effect(), control()));
 #if defined(V8_TARGET_BIG_ENDIAN)
-  result = BuildChangeEndiannessLoad(result, mem_type,
-                                     env_->module->globals[index].type);
+  result = BuildChangeEndiannessLoad(result, mem_type, global.type);
 #endif
   return result;
 }
 
 Node* WasmGraphBuilder::GlobalSet(uint32_t index, Node* val) {
   const wasm::WasmGlobal& global = env_->module->globals[index];
-  if (wasm::ValueTypes::IsReferenceType(global.type)) {
+  if (global.type.IsReferenceType()) {
     if (global.mutability && global.imported) {
       Node* base = nullptr;
       Node* offset = nullptr;
@@ -3377,24 +3323,20 @@ Node* WasmGraphBuilder::GlobalSet(uint32_t index, Node* val) {
     }
     Node* globals_buffer =
         LOAD_INSTANCE_FIELD(TaggedGlobalsBuffer, MachineType::TaggedPointer());
-    return STORE_FIXED_ARRAY_SLOT_ANY(globals_buffer,
-                                      env_->module->globals[index].offset, val);
+    return STORE_FIXED_ARRAY_SLOT_ANY(globals_buffer, global.offset, val);
   }
 
-  MachineType mem_type =
-      wasm::ValueTypes::MachineTypeFor(env_->module->globals[index].type);
+  MachineType mem_type = global.type.machine_type();
   if (mem_type.representation() == MachineRepresentation::kSimd128) {
     has_simd_ = true;
   }
   Node* base = nullptr;
   Node* offset = nullptr;
-  GetGlobalBaseAndOffset(mem_type, env_->module->globals[index], &base,
-                         &offset);
+  GetGlobalBaseAndOffset(mem_type, global, &base, &offset);
   const Operator* op = mcgraph()->machine()->Store(
       StoreRepresentation(mem_type.representation(), kNoWriteBarrier));
 #if defined(V8_TARGET_BIG_ENDIAN)
-  val = BuildChangeEndiannessStore(val, mem_type.representation(),
-                                   env_->module->globals[index].type);
+  val = BuildChangeEndiannessStore(val, mem_type.representation(), global.type);
 #endif
   return SetEffect(
       graph()->NewNode(op, base, offset, val, effect(), control()));
@@ -3409,10 +3351,9 @@ void WasmGraphBuilder::BoundsCheckTable(uint32_t table_index, Node* entry_index,
 
   int length_field_size = WasmTableObject::kCurrentLengthOffsetEnd -
                           WasmTableObject::kCurrentLengthOffset + 1;
-  Node* length_smi = LOAD_RAW(
-      table,
-      wasm::ObjectAccess::ToTagged(WasmTableObject::kCurrentLengthOffset),
-      assert_size(length_field_size, MachineType::TaggedSigned()));
+  Node* length_smi = gasm_->Load(
+      assert_size(length_field_size, MachineType::TaggedSigned()), table,
+      wasm::ObjectAccess::ToTagged(WasmTableObject::kCurrentLengthOffset));
   Node* length = BuildChangeSmiToInt32(length_smi);
 
   // Bounds check against the table size.
@@ -3423,9 +3364,9 @@ void WasmGraphBuilder::BoundsCheckTable(uint32_t table_index, Node* entry_index,
   if (base_node) {
     int storage_field_size = WasmTableObject::kEntriesOffsetEnd -
                              WasmTableObject::kEntriesOffset + 1;
-    *base_node = LOAD_RAW(
-        table, wasm::ObjectAccess::ToTagged(WasmTableObject::kEntriesOffset),
-        assert_size(storage_field_size, MachineType::TaggedPointer()));
+    *base_node = gasm_->Load(
+        assert_size(storage_field_size, MachineType::TaggedPointer()), table,
+        wasm::ObjectAccess::ToTagged(WasmTableObject::kEntriesOffset));
   }
 }
 
@@ -3457,7 +3398,7 @@ Node* WasmGraphBuilder::TableGet(uint32_t table_index, Node* index,
     Node* base = nullptr;
     Node* offset = nullptr;
     GetTableBaseAndOffset(table_index, index, position, &base, &offset);
-    return LOAD_RAW_NODE_OFFSET(base, offset, MachineType::AnyTagged());
+    return gasm_->Load(MachineType::AnyTagged(), base, offset);
   }
   // We access funcref tables through runtime calls.
   WasmTableGetDescriptor interface_descriptor;
@@ -3648,15 +3589,15 @@ Node* WasmGraphBuilder::BoundsCheckMemRange(Node** start, Node** size,
 
 const Operator* WasmGraphBuilder::GetSafeLoadOperator(int offset,
                                                       wasm::ValueType type) {
-  int alignment = offset % (wasm::ValueTypes::ElementSizeInBytes(type));
-  MachineType mach_type = wasm::ValueTypes::MachineTypeFor(type);
+  int alignment = offset % type.element_size_bytes();
+  MachineType mach_type = type.machine_type();
   if (COMPRESS_POINTERS_BOOL && mach_type.IsTagged()) {
     // We are loading tagged value from off-heap location, so we need to load
     // it as a full word otherwise we will not be able to decompress it.
     mach_type = MachineType::Pointer();
   }
   if (alignment == 0 || mcgraph()->machine()->UnalignedLoadSupported(
-                            wasm::ValueTypes::MachineRepresentationFor(type))) {
+                            type.machine_representation())) {
     return mcgraph()->machine()->Load(mach_type);
   }
   return mcgraph()->machine()->UnalignedLoad(mach_type);
@@ -3664,8 +3605,8 @@ const Operator* WasmGraphBuilder::GetSafeLoadOperator(int offset,
 
 const Operator* WasmGraphBuilder::GetSafeStoreOperator(int offset,
                                                        wasm::ValueType type) {
-  int alignment = offset % (wasm::ValueTypes::ElementSizeInBytes(type));
-  MachineRepresentation rep = wasm::ValueTypes::MachineRepresentationFor(type);
+  int alignment = offset % type.element_size_bytes();
+  MachineRepresentation rep = type.machine_representation();
   if (COMPRESS_POINTERS_BOOL && IsAnyTagged(rep)) {
     // We are storing tagged value to off-heap location, so we need to store
     // it as a full word otherwise we will not be able to decompress it.
@@ -3760,7 +3701,47 @@ LoadKind GetLoadKind(MachineGraph* mcgraph, MachineType memtype,
 }
 }  // namespace
 
-Node* WasmGraphBuilder::LoadTransform(MachineType memtype,
+// S390 simulator does not execute BE code, hence needs to also check if we are
+// running on a LE simulator.
+// TODO(miladfar): Remove SIM once V8_TARGET_BIG_ENDIAN includes the Sim.
+#if defined(V8_TARGET_BIG_ENDIAN) || defined(V8_TARGET_ARCH_S390_LE_SIM)
+Node* WasmGraphBuilder::LoadTransformBigEndian(
+    MachineType memtype, wasm::LoadTransformationKind transform, Node* value) {
+  Node* result;
+  LoadTransformation transformation = GetLoadTransformation(memtype, transform);
+
+  switch (transformation) {
+    case LoadTransformation::kS8x16LoadSplat: {
+      result = graph()->NewNode(mcgraph()->machine()->I8x16Splat(), value);
+      break;
+    }
+    case LoadTransformation::kI16x8Load8x8S:
+    case LoadTransformation::kI16x8Load8x8U:
+    case LoadTransformation::kS16x8LoadSplat: {
+      result = graph()->NewNode(mcgraph()->machine()->I16x8Splat(), value);
+      break;
+    }
+    case LoadTransformation::kI32x4Load16x4S:
+    case LoadTransformation::kI32x4Load16x4U:
+    case LoadTransformation::kS32x4LoadSplat: {
+      result = graph()->NewNode(mcgraph()->machine()->I32x4Splat(), value);
+      break;
+    }
+    case LoadTransformation::kI64x2Load32x2S:
+    case LoadTransformation::kI64x2Load32x2U:
+    case LoadTransformation::kS64x2LoadSplat: {
+      result = graph()->NewNode(mcgraph()->machine()->I64x2Splat(), value);
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+
+  return result;
+}
+#endif
+
+Node* WasmGraphBuilder::LoadTransform(wasm::ValueType type, MachineType memtype,
                                       wasm::LoadTransformationKind transform,
                                       Node* index, uint32_t offset,
                                       uint32_t alignment,
@@ -3769,24 +3750,31 @@ Node* WasmGraphBuilder::LoadTransform(MachineType memtype,
     has_simd_ = true;
   }
 
+  Node* load;
+
+#if defined(V8_TARGET_BIG_ENDIAN) || defined(V8_TARGET_ARCH_S390_LE_SIM)
+  // LoadTransform cannot efficiently be executed on BE machines as a
+  // single operation since loaded bytes need to be reversed first,
+  // therefore we divide them into separate "load" and "operation" nodes.
+  load = LoadMem(type, memtype, index, offset, alignment, position);
+  load = LoadTransformBigEndian(memtype, transform, load);
+  USE(GetLoadKind);
+#else
   // Wasm semantics throw on OOB. Introduce explicit bounds check and
   // conditioning when not using the trap handler.
-  index = BoundsCheckMem(wasm::ValueTypes::MemSize(memtype), index, offset,
-                         position, kCanOmitBoundsCheck);
+  index = BoundsCheckMem(memtype.MemSize(), index, offset, position,
+                         kCanOmitBoundsCheck);
 
   LoadTransformation transformation = GetLoadTransformation(memtype, transform);
   LoadKind load_kind = GetLoadKind(mcgraph(), memtype, use_trap_handler());
 
-  Node* load = SetEffect(graph()->NewNode(
+  load = SetEffect(graph()->NewNode(
       mcgraph()->machine()->LoadTransform(load_kind, transformation),
       MemBuffer(offset), index, effect(), control()));
 
   if (load_kind == LoadKind::kProtected) {
     SetSourcePosition(load, position);
   }
-
-#if defined(V8_TARGET_BIG_ENDIAN)
-  load = BuildChangeEndiannessLoad(load, memtype, wasm::ValueType::kWasmS128);
 #endif
 
   if (FLAG_trace_wasm_memory) {
@@ -3808,8 +3796,8 @@ Node* WasmGraphBuilder::LoadMem(wasm::ValueType type, MachineType memtype,
 
   // Wasm semantics throw on OOB. Introduce explicit bounds check and
   // conditioning when not using the trap handler.
-  index = BoundsCheckMem(wasm::ValueTypes::MemSize(memtype), index, offset,
-                         position, kCanOmitBoundsCheck);
+  index = BoundsCheckMem(memtype.MemSize(), index, offset, position,
+                         kCanOmitBoundsCheck);
 
   if (memtype.representation() == MachineRepresentation::kWord8 ||
       mcgraph()->machine()->UnalignedLoadSupported(memtype.representation())) {
@@ -4010,14 +3998,15 @@ Graph* WasmGraphBuilder::graph() { return mcgraph()->graph(); }
 
 namespace {
 Signature<MachineRepresentation>* CreateMachineSignature(
-    Zone* zone, wasm::FunctionSig* sig, WasmGraphBuilder::CallOrigin origin) {
+    Zone* zone, const wasm::FunctionSig* sig,
+    WasmGraphBuilder::CallOrigin origin) {
   Signature<MachineRepresentation>::Builder builder(zone, sig->return_count(),
                                                     sig->parameter_count());
   for (auto ret : sig->returns()) {
     if (origin == WasmGraphBuilder::kCalledFromJS) {
       builder.AddReturn(MachineRepresentation::kTagged);
     } else {
-      builder.AddReturn(wasm::ValueTypes::MachineRepresentationFor(ret));
+      builder.AddReturn(ret.machine_representation());
     }
   }
 
@@ -4028,13 +4017,65 @@ Signature<MachineRepresentation>* CreateMachineSignature(
       // provided by JavaScript, and not two 32-bit parameters.
       builder.AddParam(MachineRepresentation::kTagged);
     } else {
-      builder.AddParam(wasm::ValueTypes::MachineRepresentationFor(param));
+      builder.AddParam(param.machine_representation());
     }
   }
   return builder.Build();
 }
+
+template <typename BuiltinDescriptor>
+CallDescriptor* GetBuiltinCallDescriptor(WasmGraphBuilder* builder,
+                                         StubCallMode stub_mode) {
+  BuiltinDescriptor interface_descriptor;
+  return Linkage::GetStubCallDescriptor(
+      builder->mcgraph()->zone(),                     // zone
+      interface_descriptor,                           // descriptor
+      interface_descriptor.GetStackParameterCount(),  // stack parameter count
+      CallDescriptor::kNoFlags,                       // flags
+      Operator::kNoProperties,                        // properties
+      stub_mode);                                     // stub call mode
+}
+
 }  // namespace
 
+void WasmGraphBuilder::AddInt64LoweringReplacement(
+    CallDescriptor* original, CallDescriptor* replacement) {
+  if (!lowering_special_case_) {
+    lowering_special_case_ = std::make_unique<Int64LoweringSpecialCase>();
+  }
+  lowering_special_case_->replacements.insert({original, replacement});
+}
+
+CallDescriptor* WasmGraphBuilder::GetI32AtomicWaitCallDescriptor() {
+  if (i32_atomic_wait_descriptor_) return i32_atomic_wait_descriptor_;
+
+  i32_atomic_wait_descriptor_ =
+      GetBuiltinCallDescriptor<WasmI32AtomicWait64Descriptor>(
+          this, StubCallMode::kCallWasmRuntimeStub);
+
+  AddInt64LoweringReplacement(
+      i32_atomic_wait_descriptor_,
+      GetBuiltinCallDescriptor<WasmI32AtomicWait32Descriptor>(
+          this, StubCallMode::kCallWasmRuntimeStub));
+
+  return i32_atomic_wait_descriptor_;
+}
+
+CallDescriptor* WasmGraphBuilder::GetI64AtomicWaitCallDescriptor() {
+  if (i64_atomic_wait_descriptor_) return i64_atomic_wait_descriptor_;
+
+  i64_atomic_wait_descriptor_ =
+      GetBuiltinCallDescriptor<WasmI64AtomicWait64Descriptor>(
+          this, StubCallMode::kCallWasmRuntimeStub);
+
+  AddInt64LoweringReplacement(
+      i64_atomic_wait_descriptor_,
+      GetBuiltinCallDescriptor<WasmI64AtomicWait32Descriptor>(
+          this, StubCallMode::kCallWasmRuntimeStub));
+
+  return i64_atomic_wait_descriptor_;
+}
+
 void WasmGraphBuilder::LowerInt64(CallOrigin origin) {
   if (mcgraph()->machine()->Is64()) return;
   Int64Lowering r(mcgraph()->graph(), mcgraph()->machine(), mcgraph()->common(),
@@ -4330,6 +4371,10 @@ Node* WasmGraphBuilder::SimdOp(wasm::WasmOpcode opcode, Node* const* inputs) {
     case wasm::kExprI32x4GeU:
       return graph()->NewNode(mcgraph()->machine()->I32x4GeU(), inputs[0],
                               inputs[1]);
+    case wasm::kExprI32x4Abs:
+      return graph()->NewNode(mcgraph()->machine()->I32x4Abs(), inputs[0]);
+    case wasm::kExprI32x4BitMask:
+      return graph()->NewNode(mcgraph()->machine()->I32x4BitMask(), inputs[0]);
     case wasm::kExprI16x8Splat:
       return graph()->NewNode(mcgraph()->machine()->I16x8Splat(), inputs[0]);
     case wasm::kExprI16x8SConvertI8x16Low:
@@ -4430,6 +4475,10 @@ Node* WasmGraphBuilder::SimdOp(wasm::WasmOpcode opcode, Node* const* inputs) {
     case wasm::kExprI16x8RoundingAverageU:
       return graph()->NewNode(mcgraph()->machine()->I16x8RoundingAverageU(),
                               inputs[0], inputs[1]);
+    case wasm::kExprI16x8Abs:
+      return graph()->NewNode(mcgraph()->machine()->I16x8Abs(), inputs[0]);
+    case wasm::kExprI16x8BitMask:
+      return graph()->NewNode(mcgraph()->machine()->I16x8BitMask(), inputs[0]);
     case wasm::kExprI8x16Splat:
       return graph()->NewNode(mcgraph()->machine()->I8x16Splat(), inputs[0]);
     case wasm::kExprI8x16Neg:
@@ -4515,6 +4564,10 @@ Node* WasmGraphBuilder::SimdOp(wasm::WasmOpcode opcode, Node* const* inputs) {
     case wasm::kExprI8x16RoundingAverageU:
       return graph()->NewNode(mcgraph()->machine()->I8x16RoundingAverageU(),
                               inputs[0], inputs[1]);
+    case wasm::kExprI8x16Abs:
+      return graph()->NewNode(mcgraph()->machine()->I8x16Abs(), inputs[0]);
+    case wasm::kExprI8x16BitMask:
+      return graph()->NewNode(mcgraph()->machine()->I8x16BitMask(), inputs[0]);
     case wasm::kExprS128And:
       return graph()->NewNode(mcgraph()->machine()->S128And(), inputs[0],
                               inputs[1]);
@@ -4692,9 +4745,8 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
   switch (opcode) {
 #define BUILD_ATOMIC_BINOP(Name, Operation, Type, Prefix)                     \
   case wasm::kExpr##Name: {                                                   \
-    Node* index = CheckBoundsAndAlignment(                                    \
-        wasm::ValueTypes::MemSize(MachineType::Type()), inputs[0], offset,    \
-        position);                                                            \
+    Node* index = CheckBoundsAndAlignment(MachineType::Type().MemSize(),      \
+                                          inputs[0], offset, position);       \
     node = graph()->NewNode(                                                  \
         mcgraph()->machine()->Prefix##Atomic##Operation(MachineType::Type()), \
         MemBuffer(offset), index, inputs[1], effect(), control());            \
@@ -4705,9 +4757,8 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
 
 #define BUILD_ATOMIC_CMP_EXCHG(Name, Type, Prefix)                            \
   case wasm::kExpr##Name: {                                                   \
-    Node* index = CheckBoundsAndAlignment(                                    \
-        wasm::ValueTypes::MemSize(MachineType::Type()), inputs[0], offset,    \
-        position);                                                            \
+    Node* index = CheckBoundsAndAlignment(MachineType::Type().MemSize(),      \
+                                          inputs[0], offset, position);       \
     node = graph()->NewNode(                                                  \
         mcgraph()->machine()->Prefix##AtomicCompareExchange(                  \
             MachineType::Type()),                                             \
@@ -4717,24 +4768,22 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
     ATOMIC_CMP_EXCHG_LIST(BUILD_ATOMIC_CMP_EXCHG)
 #undef BUILD_ATOMIC_CMP_EXCHG
 
-#define BUILD_ATOMIC_LOAD_OP(Name, Type, Prefix)                           \
-  case wasm::kExpr##Name: {                                                \
-    Node* index = CheckBoundsAndAlignment(                                 \
-        wasm::ValueTypes::MemSize(MachineType::Type()), inputs[0], offset, \
-        position);                                                         \
-    node = graph()->NewNode(                                               \
-        mcgraph()->machine()->Prefix##AtomicLoad(MachineType::Type()),     \
-        MemBuffer(offset), index, effect(), control());                    \
-    break;                                                                 \
+#define BUILD_ATOMIC_LOAD_OP(Name, Type, Prefix)                         \
+  case wasm::kExpr##Name: {                                              \
+    Node* index = CheckBoundsAndAlignment(MachineType::Type().MemSize(), \
+                                          inputs[0], offset, position);  \
+    node = graph()->NewNode(                                             \
+        mcgraph()->machine()->Prefix##AtomicLoad(MachineType::Type()),   \
+        MemBuffer(offset), index, effect(), control());                  \
+    break;                                                               \
   }
     ATOMIC_LOAD_LIST(BUILD_ATOMIC_LOAD_OP)
 #undef BUILD_ATOMIC_LOAD_OP
 
 #define BUILD_ATOMIC_STORE_OP(Name, Type, Rep, Prefix)                         \
   case wasm::kExpr##Name: {                                                    \
-    Node* index = CheckBoundsAndAlignment(                                     \
-        wasm::ValueTypes::MemSize(MachineType::Type()), inputs[0], offset,     \
-        position);                                                             \
+    Node* index = CheckBoundsAndAlignment(MachineType::Type().MemSize(),       \
+                                          inputs[0], offset, position);        \
     node = graph()->NewNode(                                                   \
         mcgraph()->machine()->Prefix##AtomicStore(MachineRepresentation::Rep), \
         MemBuffer(offset), index, inputs[1], effect(), control());             \
@@ -4743,9 +4792,8 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
     ATOMIC_STORE_LIST(BUILD_ATOMIC_STORE_OP)
 #undef BUILD_ATOMIC_STORE_OP
     case wasm::kExprAtomicNotify: {
-      Node* index = CheckBoundsAndAlignment(
-          wasm::ValueTypes::MemSize(MachineType::Uint32()), inputs[0], offset,
-          position);
+      Node* index = CheckBoundsAndAlignment(MachineType::Uint32().MemSize(),
+                                            inputs[0], offset, position);
       // Now that we've bounds-checked, compute the effective address.
       Node* address = graph()->NewNode(mcgraph()->machine()->Int32Add(),
                                        Uint32Constant(offset), index);
@@ -4764,64 +4812,44 @@ Node* WasmGraphBuilder::AtomicOp(wasm::WasmOpcode opcode, Node* const* inputs,
     }
 
     case wasm::kExprI32AtomicWait: {
-      Node* index = CheckBoundsAndAlignment(
-          wasm::ValueTypes::MemSize(MachineType::Uint32()), inputs[0], offset,
-          position);
+      Node* index = CheckBoundsAndAlignment(MachineType::Uint32().MemSize(),
+                                            inputs[0], offset, position);
       // Now that we've bounds-checked, compute the effective address.
       Node* address = graph()->NewNode(mcgraph()->machine()->Int32Add(),
                                        Uint32Constant(offset), index);
-      Node* timeout;
-      if (mcgraph()->machine()->Is32()) {
-        timeout = BuildF64SConvertI64(inputs[2]);
-      } else {
-        timeout = graph()->NewNode(mcgraph()->machine()->RoundInt64ToFloat64(),
-                                   inputs[2]);
-      }
-      WasmI32AtomicWaitDescriptor interface_descriptor;
-      auto call_descriptor = Linkage::GetStubCallDescriptor(
-          mcgraph()->zone(), interface_descriptor,
-          interface_descriptor.GetStackParameterCount(),
-          CallDescriptor::kNoFlags, Operator::kNoProperties,
-          StubCallMode::kCallWasmRuntimeStub);
+
+      auto call_descriptor = GetI32AtomicWaitCallDescriptor();
+
+      intptr_t target = mcgraph()->machine()->Is64()
+                            ? wasm::WasmCode::kWasmI32AtomicWait64
+                            : wasm::WasmCode::kWasmI32AtomicWait32;
       Node* call_target = mcgraph()->RelocatableIntPtrConstant(
-          wasm::WasmCode::kWasmI32AtomicWait, RelocInfo::WASM_STUB_CALL);
+          target, RelocInfo::WASM_STUB_CALL);
+
       node = graph()->NewNode(mcgraph()->common()->Call(call_descriptor),
-                              call_target, address, inputs[1], timeout,
+                              call_target, address, inputs[1], inputs[2],
                               effect(), control());
       break;
     }
 
     case wasm::kExprI64AtomicWait: {
-      Node* index = CheckBoundsAndAlignment(
-          wasm::ValueTypes::MemSize(MachineType::Uint64()), inputs[0], offset,
-          position);
+      Node* index = CheckBoundsAndAlignment(MachineType::Uint64().MemSize(),
+                                            inputs[0], offset, position);
       // Now that we've bounds-checked, compute the effective address.
       Node* address = graph()->NewNode(mcgraph()->machine()->Int32Add(),
                                        Uint32Constant(offset), index);
-      Node* timeout;
-      if (mcgraph()->machine()->Is32()) {
-        timeout = BuildF64SConvertI64(inputs[2]);
-      } else {
-        timeout = graph()->NewNode(mcgraph()->machine()->RoundInt64ToFloat64(),
-                                   inputs[2]);
-      }
-      Node* expected_value_low = graph()->NewNode(
-          mcgraph()->machine()->TruncateInt64ToInt32(), inputs[1]);
-      Node* tmp = graph()->NewNode(mcgraph()->machine()->Word64Shr(), inputs[1],
-                                   Int64Constant(32));
-      Node* expected_value_high =
-          graph()->NewNode(mcgraph()->machine()->TruncateInt64ToInt32(), tmp);
-      WasmI64AtomicWaitDescriptor interface_descriptor;
-      auto call_descriptor = Linkage::GetStubCallDescriptor(
-          mcgraph()->zone(), interface_descriptor,
-          interface_descriptor.GetStackParameterCount(),
-          CallDescriptor::kNoFlags, Operator::kNoProperties,
-          StubCallMode::kCallWasmRuntimeStub);
+
+      CallDescriptor* call_descriptor = GetI64AtomicWaitCallDescriptor();
+
+      intptr_t target = mcgraph()->machine()->Is64()
+                            ? wasm::WasmCode::kWasmI64AtomicWait64
+                            : wasm::WasmCode::kWasmI64AtomicWait32;
       Node* call_target = mcgraph()->RelocatableIntPtrConstant(
-          wasm::WasmCode::kWasmI64AtomicWait, RelocInfo::WASM_STUB_CALL);
+          target, RelocInfo::WASM_STUB_CALL);
+
       node = graph()->NewNode(mcgraph()->common()->Call(call_descriptor),
-                              call_target, address, expected_value_high,
-                              expected_value_low, timeout, effect(), control());
+                              call_target, address, inputs[1], inputs[2],
+                              effect(), control());
       break;
     }
 
@@ -4848,50 +4876,21 @@ Node* WasmGraphBuilder::MemoryInit(uint32_t data_segment_index, Node* dst,
   // validation.
   DCHECK_LT(data_segment_index, env_->module->num_declared_data_segments);
 
-  Node* dst_fail = BoundsCheckMemRange(&dst, &size, position);
-  TrapIfTrue(wasm::kTrapMemOutOfBounds, dst_fail, position);
-
-  Node* seg_index = Uint32Constant(data_segment_index);
-  auto m = mcgraph()->machine();
-
-  {
-    // Load segment size from WasmInstanceObject::data_segment_sizes.
-    Node* seg_size_array =
-        LOAD_INSTANCE_FIELD(DataSegmentSizes, MachineType::Pointer());
-    STATIC_ASSERT(wasm::kV8MaxWasmDataSegments <= kMaxUInt32 >> 2);
-    Node* scaled_index = Uint32ToUintptr(
-        graph()->NewNode(m->Word32Shl(), seg_index, Int32Constant(2)));
-    Node* seg_size = SetEffect(graph()->NewNode(m->Load(MachineType::Uint32()),
-                                                seg_size_array, scaled_index,
-                                                effect(), control()));
-
-    // Bounds check the src index against the segment size.
-    Node* src_fail = BoundsCheckRange(src, &size, seg_size, position);
-    TrapIfTrue(wasm::kTrapMemOutOfBounds, src_fail, position);
-  }
-
-  {
-    // Load segment's base pointer from WasmInstanceObject::data_segment_starts.
-    Node* seg_start_array =
-        LOAD_INSTANCE_FIELD(DataSegmentStarts, MachineType::Pointer());
-    STATIC_ASSERT(wasm::kV8MaxWasmDataSegments <=
-                  kMaxUInt32 / kSystemPointerSize);
-    Node* scaled_index = Uint32ToUintptr(graph()->NewNode(
-        m->Word32Shl(), seg_index, Int32Constant(kSystemPointerSizeLog2)));
-    Node* seg_start = SetEffect(
-        graph()->NewNode(m->Load(MachineType::Pointer()), seg_start_array,
-                         scaled_index, effect(), control()));
+  Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(
+      ExternalReference::wasm_memory_init()));
 
-    // Convert src index to pointer.
-    src = graph()->NewNode(m->IntAdd(), seg_start, Uint32ToUintptr(src));
-  }
+  Node* stack_slot = StoreArgsInStackSlot(
+      {{MachineType::PointerRepresentation(), instance_node_.get()},
+       {MachineRepresentation::kWord32, dst},
+       {MachineRepresentation::kWord32, src},
+       {MachineRepresentation::kWord32,
+        gasm_->Uint32Constant(data_segment_index)},
+       {MachineRepresentation::kWord32, size}});
 
-  Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(
-      ExternalReference::wasm_memory_copy()));
-  MachineType sig_types[] = {MachineType::Pointer(), MachineType::Pointer(),
-                             MachineType::Uint32()};
-  MachineSignature sig(0, 3, sig_types);
-  return SetEffect(BuildCCall(&sig, function, dst, src, size));
+  MachineType sig_types[] = {MachineType::Int32(), MachineType::Pointer()};
+  MachineSignature sig(1, 1, sig_types);
+  Node* call = SetEffect(BuildCCall(&sig, function, stack_slot));
+  return TrapIfFalse(wasm::kTrapMemOutOfBounds, call, position);
 }
 
 Node* WasmGraphBuilder::DataDrop(uint32_t data_segment_index,
@@ -4909,51 +4908,77 @@ Node* WasmGraphBuilder::DataDrop(uint32_t data_segment_index,
                        mcgraph()->Int32Constant(0), effect(), control()));
 }
 
+Node* WasmGraphBuilder::StoreArgsInStackSlot(
+    std::initializer_list<std::pair<MachineRepresentation, Node*>> args) {
+  int slot_size = 0;
+  for (auto arg : args) {
+    slot_size += ElementSizeInBytes(arg.first);
+  }
+  DCHECK_LT(0, slot_size);
+  Node* stack_slot =
+      graph()->NewNode(mcgraph()->machine()->StackSlot(slot_size));
+
+  int offset = 0;
+  for (auto arg : args) {
+    MachineRepresentation type = arg.first;
+    Node* value = arg.second;
+    gasm_->Store(StoreRepresentation(type, kNoWriteBarrier), stack_slot,
+                 mcgraph()->Int32Constant(offset), value);
+    offset += ElementSizeInBytes(type);
+  }
+  return stack_slot;
+}
+
 Node* WasmGraphBuilder::MemoryCopy(Node* dst, Node* src, Node* size,
                                    wasm::WasmCodePosition position) {
-  Node* dst_fail = BoundsCheckMemRange(&dst, &size, position);
-  TrapIfTrue(wasm::kTrapMemOutOfBounds, dst_fail, position);
-  Node* src_fail = BoundsCheckMemRange(&src, &size, position);
-  TrapIfTrue(wasm::kTrapMemOutOfBounds, src_fail, position);
-
   Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(
       ExternalReference::wasm_memory_copy()));
-  MachineType sig_types[] = {MachineType::Pointer(), MachineType::Pointer(),
-                             MachineType::Uint32()};
-  MachineSignature sig(0, 3, sig_types);
-  return SetEffect(BuildCCall(&sig, function, dst, src, size));
+
+  Node* stack_slot = StoreArgsInStackSlot(
+      {{MachineType::PointerRepresentation(), instance_node_.get()},
+       {MachineRepresentation::kWord32, dst},
+       {MachineRepresentation::kWord32, src},
+       {MachineRepresentation::kWord32, size}});
+
+  MachineType sig_types[] = {MachineType::Int32(), MachineType::Pointer()};
+  MachineSignature sig(1, 1, sig_types);
+  Node* call = SetEffect(BuildCCall(&sig, function, stack_slot));
+  return TrapIfFalse(wasm::kTrapMemOutOfBounds, call, position);
 }
 
 Node* WasmGraphBuilder::MemoryFill(Node* dst, Node* value, Node* size,
                                    wasm::WasmCodePosition position) {
-  Node* fail = BoundsCheckMemRange(&dst, &size, position);
-  TrapIfTrue(wasm::kTrapMemOutOfBounds, fail, position);
-
   Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(
       ExternalReference::wasm_memory_fill()));
-  MachineType sig_types[] = {MachineType::Pointer(), MachineType::Uint32(),
-                             MachineType::Uint32()};
-  MachineSignature sig(0, 3, sig_types);
-  return SetEffect(BuildCCall(&sig, function, dst, value, size));
+
+  Node* stack_slot = StoreArgsInStackSlot(
+      {{MachineType::PointerRepresentation(), instance_node_.get()},
+       {MachineRepresentation::kWord32, dst},
+       {MachineRepresentation::kWord32, value},
+       {MachineRepresentation::kWord32, size}});
+
+  MachineType sig_types[] = {MachineType::Int32(), MachineType::Pointer()};
+  MachineSignature sig(1, 1, sig_types);
+  Node* call = SetEffect(BuildCCall(&sig, function, stack_slot));
+  return TrapIfFalse(wasm::kTrapMemOutOfBounds, call, position);
 }
 
 Node* WasmGraphBuilder::TableInit(uint32_t table_index,
                                   uint32_t elem_segment_index, Node* dst,
                                   Node* src, Node* size,
                                   wasm::WasmCodePosition position) {
-  DCHECK_LT(table_index, env_->module->tables.size());
-  // The elem segment index must be in bounds since it is required by
-  // validation.
-  DCHECK_LT(elem_segment_index, env_->module->elem_segments.size());
+  auto call_descriptor = GetBuiltinCallDescriptor<WasmTableInitDescriptor>(
+      this, StubCallMode::kCallWasmRuntimeStub);
 
-  Node* args[] = {
+  intptr_t target = wasm::WasmCode::kWasmTableInit;
+  Node* call_target =
+      mcgraph()->RelocatableIntPtrConstant(target, RelocInfo::WASM_STUB_CALL);
+
+  return gasm_->Call(
+      call_descriptor, call_target, dst, src, size,
       graph()->NewNode(mcgraph()->common()->NumberConstant(table_index)),
-      graph()->NewNode(mcgraph()->common()->NumberConstant(elem_segment_index)),
-      BuildConvertUint32ToSmiWithSaturation(dst, FLAG_wasm_max_table_size),
-      BuildConvertUint32ToSmiWithSaturation(src, FLAG_wasm_max_table_size),
-      BuildConvertUint32ToSmiWithSaturation(size, FLAG_wasm_max_table_size)};
-  return SetEffect(
-      BuildCallToRuntime(Runtime::kWasmTableInit, args, arraysize(args)));
+      graph()->NewNode(
+          mcgraph()->common()->NumberConstant(elem_segment_index)));
 }
 
 Node* WasmGraphBuilder::ElemDrop(uint32_t elem_segment_index,
@@ -4976,16 +5001,17 @@ Node* WasmGraphBuilder::TableCopy(uint32_t table_dst_index,
                                   uint32_t table_src_index, Node* dst,
                                   Node* src, Node* size,
                                   wasm::WasmCodePosition position) {
-  Node* args[] = {
-      graph()->NewNode(mcgraph()->common()->NumberConstant(table_dst_index)),
-      graph()->NewNode(mcgraph()->common()->NumberConstant(table_src_index)),
-      BuildConvertUint32ToSmiWithSaturation(dst, FLAG_wasm_max_table_size),
-      BuildConvertUint32ToSmiWithSaturation(src, FLAG_wasm_max_table_size),
-      BuildConvertUint32ToSmiWithSaturation(size, FLAG_wasm_max_table_size)};
-  Node* result =
-      BuildCallToRuntime(Runtime::kWasmTableCopy, args, arraysize(args));
+  auto call_descriptor = GetBuiltinCallDescriptor<WasmTableCopyDescriptor>(
+      this, StubCallMode::kCallWasmRuntimeStub);
 
-  return result;
+  intptr_t target = wasm::WasmCode::kWasmTableCopy;
+  Node* call_target =
+      mcgraph()->RelocatableIntPtrConstant(target, RelocInfo::WASM_STUB_CALL);
+
+  return gasm_->Call(
+      call_descriptor, call_target, dst, src, size,
+      graph()->NewNode(mcgraph()->common()->NumberConstant(table_dst_index)),
+      graph()->NewNode(mcgraph()->common()->NumberConstant(table_src_index)));
 }
 
 Node* WasmGraphBuilder::TableGrow(uint32_t table_index, Node* value,
@@ -5004,10 +5030,9 @@ Node* WasmGraphBuilder::TableSize(uint32_t table_index) {
 
   int length_field_size = WasmTableObject::kCurrentLengthOffsetEnd -
                           WasmTableObject::kCurrentLengthOffset + 1;
-  Node* length_smi = LOAD_RAW(
-      table,
-      wasm::ObjectAccess::ToTagged(WasmTableObject::kCurrentLengthOffset),
-      assert_size(length_field_size, MachineType::TaggedSigned()));
+  Node* length_smi = gasm_->Load(
+      assert_size(length_field_size, MachineType::TaggedSigned()), table,
+      wasm::ObjectAccess::ToTagged(WasmTableObject::kCurrentLengthOffset));
 
   return BuildChangeSmiToInt32(length_smi);
 }
@@ -5053,86 +5078,39 @@ void WasmGraphBuilder::RemoveBytecodePositionDecorator() {
 }
 
 namespace {
+
 class WasmWrapperGraphBuilder : public WasmGraphBuilder {
  public:
   WasmWrapperGraphBuilder(Zone* zone, MachineGraph* mcgraph,
-                          wasm::FunctionSig* sig,
+                          const wasm::FunctionSig* sig,
                           compiler::SourcePositionTable* spt,
                           StubCallMode stub_mode, wasm::WasmFeatures features)
       : WasmGraphBuilder(nullptr, zone, mcgraph, sig, spt),
         stub_mode_(stub_mode),
         enabled_features_(features) {}
 
-  CallDescriptor* GetI32PairToBigIntCallDescriptor() {
-    I32PairToBigIntDescriptor interface_descriptor;
-
-    return Linkage::GetStubCallDescriptor(
-        mcgraph()->zone(),                              // zone
-        interface_descriptor,                           // descriptor
-        interface_descriptor.GetStackParameterCount(),  // stack parameter count
-        CallDescriptor::kNoFlags,                       // flags
-        Operator::kNoProperties,                        // properties
-        stub_mode_);                                    // stub call mode
-  }
-
   CallDescriptor* GetI64ToBigIntCallDescriptor() {
-    if (!lowering_special_case_) {
-      lowering_special_case_ = std::make_unique<Int64LoweringSpecialCase>();
-    }
+    if (i64_to_bigint_descriptor_) return i64_to_bigint_descriptor_;
 
-    if (lowering_special_case_->i64_to_bigint_call_descriptor) {
-      return lowering_special_case_->i64_to_bigint_call_descriptor;
-    }
+    i64_to_bigint_descriptor_ =
+        GetBuiltinCallDescriptor<I64ToBigIntDescriptor>(this, stub_mode_);
 
-    I64ToBigIntDescriptor interface_descriptor;
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        mcgraph()->zone(),                              // zone
-        interface_descriptor,                           // descriptor
-        interface_descriptor.GetStackParameterCount(),  // stack parameter count
-        CallDescriptor::kNoFlags,                       // flags
-        Operator::kNoProperties,                        // properties
-        stub_mode_);                                    // stub call mode
-
-    lowering_special_case_->i64_to_bigint_call_descriptor = call_descriptor;
-    lowering_special_case_->i32_pair_to_bigint_call_descriptor =
-        GetI32PairToBigIntCallDescriptor();
-    return call_descriptor;
-  }
-
-  CallDescriptor* GetBigIntToI32PairCallDescriptor() {
-    BigIntToI32PairDescriptor interface_descriptor;
-
-    return Linkage::GetStubCallDescriptor(
-        mcgraph()->zone(),                              // zone
-        interface_descriptor,                           // descriptor
-        interface_descriptor.GetStackParameterCount(),  // stack parameter count
-        CallDescriptor::kNoFlags,                       // flags
-        Operator::kNoProperties,                        // properties
-        stub_mode_);                                    // stub call mode
+    AddInt64LoweringReplacement(
+        i64_to_bigint_descriptor_,
+        GetBuiltinCallDescriptor<I32PairToBigIntDescriptor>(this, stub_mode_));
+    return i64_to_bigint_descriptor_;
   }
 
   CallDescriptor* GetBigIntToI64CallDescriptor() {
-    if (!lowering_special_case_) {
-      lowering_special_case_ = std::make_unique<Int64LoweringSpecialCase>();
-    }
-
-    if (lowering_special_case_->bigint_to_i64_call_descriptor) {
-      return lowering_special_case_->bigint_to_i64_call_descriptor;
-    }
+    if (bigint_to_i64_descriptor_) return bigint_to_i64_descriptor_;
 
-    BigIntToI64Descriptor interface_descriptor;
-    auto call_descriptor = Linkage::GetStubCallDescriptor(
-        mcgraph()->zone(),                              // zone
-        interface_descriptor,                           // descriptor
-        interface_descriptor.GetStackParameterCount(),  // stack parameter count
-        CallDescriptor::kNoFlags,                       // flags
-        Operator::kNoProperties,                        // properties
-        stub_mode_);                                    // stub call mode
+    bigint_to_i64_descriptor_ =
+        GetBuiltinCallDescriptor<BigIntToI64Descriptor>(this, stub_mode_);
 
-    lowering_special_case_->bigint_to_i64_call_descriptor = call_descriptor;
-    lowering_special_case_->bigint_to_i32_pair_call_descriptor =
-        GetBigIntToI32PairCallDescriptor();
-    return call_descriptor;
+    AddInt64LoweringReplacement(
+        bigint_to_i64_descriptor_,
+        GetBuiltinCallDescriptor<BigIntToI32PairDescriptor>(this, stub_mode_));
+    return bigint_to_i64_descriptor_;
   }
 
   Node* GetBuiltinPointerTarget(Builtins::Name builtin_id) {
@@ -5148,7 +5126,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
                : GetBuiltinPointerTarget(builtin_id);
   }
 
-  Node* BuildAllocateHeapNumberWithValue(Node* value, Node* control) {
+  Node* BuildAllocateHeapNumberWithValue(Node* value) {
     MachineOperatorBuilder* machine = mcgraph()->machine();
     CommonOperatorBuilder* common = mcgraph()->common();
     Node* target = GetTargetForBuiltinCall(wasm::WasmCode::kAllocateHeapNumber,
@@ -5160,12 +5138,12 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       allocate_heap_number_operator_.set(common->Call(call_descriptor));
     }
     Node* heap_number = graph()->NewNode(allocate_heap_number_operator_.get(),
-                                         target, effect(), control);
+                                         target, effect(), control());
     SetEffect(
         graph()->NewNode(machine->Store(StoreRepresentation(
                              MachineRepresentation::kFloat64, kNoWriteBarrier)),
                          heap_number, BuildHeapNumberValueIndexConstant(),
-                         value, heap_number, control));
+                         value, heap_number, control()));
     return heap_number;
   }
 
@@ -5202,8 +5180,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
           mcgraph()->Int32Constant(WASM_INSTANCE_OBJECT_OFFSET(IsolateRoot)),
           graph()->start(), graph()->start());
       undefined_value_node_ = graph()->NewNode(
-          mcgraph()->machine()->Load(MachineType::TaggedPointer()),
-          isolate_root,
+          mcgraph()->machine()->Load(MachineType::Pointer()), isolate_root,
           mcgraph()->Int32Constant(
               IsolateData::root_slot_offset(RootIndex::kUndefinedValue)),
           isolate_root, graph()->start());
@@ -5212,129 +5189,96 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* BuildChangeInt32ToTagged(Node* value) {
-    MachineOperatorBuilder* machine = mcgraph()->machine();
-    CommonOperatorBuilder* common = mcgraph()->common();
-
     if (SmiValuesAre32Bits()) {
       return BuildChangeInt32ToSmi(value);
     }
     DCHECK(SmiValuesAre31Bits());
 
-    Node* old_effect = effect();
-    Node* old_control = control();
-    Node* add = graph()->NewNode(machine->Int32AddWithOverflow(), value, value,
-                                 graph()->start());
+    auto allocate_heap_number = gasm_->MakeDeferredLabel();
+    auto done = gasm_->MakeLabel(MachineRepresentation::kTagged);
 
-    Node* ovf = graph()->NewNode(common->Projection(1), add, graph()->start());
-    Node* branch =
-        graph()->NewNode(common->Branch(BranchHint::kFalse), ovf, old_control);
+    // The smi value is {2 * value}. If that overflows, we need to allocate a
+    // heap number.
+    Node* add = gasm_->Int32AddWithOverflow(value, value);
+    Node* ovf = gasm_->Projection(1, add);
+    gasm_->GotoIf(ovf, &allocate_heap_number);
 
-    Node* if_true = graph()->NewNode(common->IfTrue(), branch);
-    Node* vtrue = BuildAllocateHeapNumberWithValue(
-        graph()->NewNode(machine->ChangeInt32ToFloat64(), value), if_true);
-    Node* etrue = effect();
+    // If it didn't overflow, the result is {2 * value} as pointer-sized value.
+    Node* smi_tagged = BuildChangeInt32ToIntPtr(gasm_->Projection(0, add));
+    gasm_->Goto(&done, smi_tagged);
 
-    Node* if_false = graph()->NewNode(common->IfFalse(), branch);
-    Node* vfalse = graph()->NewNode(common->Projection(0), add, if_false);
-    vfalse = BuildChangeInt32ToIntPtr(vfalse);
+    gasm_->Bind(&allocate_heap_number);
+    Node* heap_number =
+        BuildAllocateHeapNumberWithValue(gasm_->ChangeInt32ToFloat64(value));
+    gasm_->Goto(&done, heap_number);
 
-    Node* merge =
-        SetControl(graph()->NewNode(common->Merge(2), if_true, if_false));
-    SetEffect(graph()->NewNode(common->EffectPhi(2), etrue, old_effect, merge));
-    return graph()->NewNode(common->Phi(MachineRepresentation::kTagged, 2),
-                            vtrue, vfalse, merge);
+    gasm_->Bind(&done);
+    return done.PhiAt(0);
   }
 
   Node* BuildChangeFloat64ToTagged(Node* value) {
-    MachineOperatorBuilder* machine = mcgraph()->machine();
-    CommonOperatorBuilder* common = mcgraph()->common();
-
     // Check several conditions:
     //  i32?
     //  ├─ true: zero?
-    //  │        ├─ true: negative?
-    //  │        │        ├─ true: box
-    //  │        │        └─ false: potentially Smi
+    //  │        ├─ true: positive?
+    //  │        │        ├─ true: potentially Smi
+    //  │        │        └─ false: box (-0)
     //  │        └─ false: potentially Smi
-    //  └─ false: box
+    //  └─ false: box (non-int)
     // For potential Smi values, depending on whether Smis are 31 or 32 bit, we
     // still need to check whether the value fits in a Smi.
 
-    Node* old_effect = effect();
-    Node* old_control = control();
-    Node* value32 = graph()->NewNode(machine->RoundFloat64ToInt32(), value);
-    Node* check_i32 = graph()->NewNode(
-        machine->Float64Equal(), value,
-        graph()->NewNode(machine->ChangeInt32ToFloat64(), value32));
-    Node* branch_i32 =
-        graph()->NewNode(common->Branch(), check_i32, old_control);
+    auto box_value = gasm_->MakeDeferredLabel();
+    auto potentially_smi = gasm_->MakeLabel();
+    auto done = gasm_->MakeLabel(MachineRepresentation::kTagged);
 
-    Node* if_i32 = graph()->NewNode(common->IfTrue(), branch_i32);
-    Node* if_not_i32 = graph()->NewNode(common->IfFalse(), branch_i32);
+    Node* value32 = gasm_->RoundFloat64ToInt32(value);
+    Node* check_i32 =
+        gasm_->Float64Equal(value, gasm_->ChangeInt32ToFloat64(value32));
+    gasm_->GotoIfNot(check_i32, &box_value);
 
     // We only need to check for -0 if the {value} can potentially contain -0.
-    Node* check_zero = graph()->NewNode(machine->Word32Equal(), value32,
-                                        mcgraph()->Int32Constant(0));
-    Node* branch_zero = graph()->NewNode(common->Branch(BranchHint::kFalse),
-                                         check_zero, if_i32);
-
-    Node* if_zero = graph()->NewNode(common->IfTrue(), branch_zero);
-    Node* if_not_zero = graph()->NewNode(common->IfFalse(), branch_zero);
-
-    // In case of 0, we need to check the high bits for the IEEE -0 pattern.
-    Node* check_negative = graph()->NewNode(
-        machine->Int32LessThan(),
-        graph()->NewNode(machine->Float64ExtractHighWord32(), value),
-        mcgraph()->Int32Constant(0));
-    Node* branch_negative = graph()->NewNode(common->Branch(BranchHint::kFalse),
-                                             check_negative, if_zero);
-
-    Node* if_negative = graph()->NewNode(common->IfTrue(), branch_negative);
-    Node* if_not_negative =
-        graph()->NewNode(common->IfFalse(), branch_negative);
-
-    // We need to create a box for negative 0.
-    Node* if_smi =
-        graph()->NewNode(common->Merge(2), if_not_zero, if_not_negative);
-    Node* if_box = graph()->NewNode(common->Merge(2), if_not_i32, if_negative);
+    Node* check_zero = gasm_->Word32Equal(value32, gasm_->Int32Constant(0));
+    gasm_->GotoIfNot(check_zero, &potentially_smi);
+
+    // In case of 0, we need to check the MSB (sign bit).
+    Node* check_positive = gasm_->Word32Equal(
+        gasm_->Float64ExtractHighWord32(value), gasm_->Int32Constant(0));
+    gasm_->Branch(check_positive, &potentially_smi, &box_value);
+
+    gasm_->Bind(&potentially_smi);
 
     // On 64-bit machines we can just wrap the 32-bit integer in a smi, for
     // 32-bit machines we need to deal with potential overflow and fallback to
     // boxing.
-    Node* vsmi;
     if (SmiValuesAre32Bits()) {
-      vsmi = BuildChangeInt32ToSmi(value32);
+      gasm_->Goto(&done, BuildChangeInt32ToSmi(value32));
     } else {
       DCHECK(SmiValuesAre31Bits());
-      Node* smi_tag = graph()->NewNode(machine->Int32AddWithOverflow(), value32,
-                                       value32, if_smi);
+      // The smi value is {2 * value}. If that overflows, we need to box.
+      Node* smi_tag = gasm_->Int32AddWithOverflow(value32, value32);
 
-      Node* check_ovf =
-          graph()->NewNode(common->Projection(1), smi_tag, if_smi);
-      Node* branch_ovf = graph()->NewNode(common->Branch(BranchHint::kFalse),
-                                          check_ovf, if_smi);
+      Node* check_ovf = gasm_->Projection(1, smi_tag);
+      gasm_->GotoIf(check_ovf, &box_value);
 
-      Node* if_ovf = graph()->NewNode(common->IfTrue(), branch_ovf);
-      if_box = graph()->NewNode(common->Merge(2), if_ovf, if_box);
-
-      if_smi = graph()->NewNode(common->IfFalse(), branch_ovf);
-      vsmi = graph()->NewNode(common->Projection(0), smi_tag, if_smi);
-      vsmi = BuildChangeInt32ToIntPtr(vsmi);
+      Node* smi_value = gasm_->Projection(0, smi_tag);
+      // With pointer compression, only the lower 32 bits are used.
+      if (!COMPRESS_POINTERS_BOOL) {
+        smi_value = BuildChangeInt32ToIntPtr(smi_value);
+      }
+      gasm_->Goto(&done, smi_value);
     }
 
     // Allocate the box for the {value}.
-    Node* vbox = BuildAllocateHeapNumberWithValue(value, if_box);
-    Node* ebox = effect();
+    gasm_->Bind(&box_value);
+    gasm_->Goto(&done, BuildAllocateHeapNumberWithValue(value));
 
-    Node* merge =
-        SetControl(graph()->NewNode(common->Merge(2), if_smi, if_box));
-    SetEffect(graph()->NewNode(common->EffectPhi(2), old_effect, ebox, merge));
-    return graph()->NewNode(common->Phi(MachineRepresentation::kTagged, 2),
-                            vsmi, vbox, merge);
+    gasm_->Bind(&done);
+    return done.PhiAt(0);
   }
 
   int AddArgumentNodes(Vector<Node*> args, int pos, int param_count,
-                       wasm::FunctionSig* sig) {
+                       const wasm::FunctionSig* sig) {
     // Convert wasm numbers to JS values.
     for (int i = 0; i < param_count; ++i) {
       Node* param =
@@ -5368,27 +5312,28 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* ToJS(Node* node, wasm::ValueType type) {
-    switch (type) {
-      case wasm::kWasmI32:
+    switch (type.kind()) {
+      case wasm::ValueType::kI32:
         return BuildChangeInt32ToTagged(node);
-      case wasm::kWasmS128:
+      case wasm::ValueType::kS128:
         UNREACHABLE();
-      case wasm::kWasmI64: {
+      case wasm::ValueType::kI64: {
         DCHECK(enabled_features_.has_bigint());
         return BuildChangeInt64ToBigInt(node);
       }
-      case wasm::kWasmF32:
+      case wasm::ValueType::kF32:
         node = graph()->NewNode(mcgraph()->machine()->ChangeFloat32ToFloat64(),
                                 node);
         return BuildChangeFloat64ToTagged(node);
-      case wasm::kWasmF64:
+      case wasm::ValueType::kF64:
         return BuildChangeFloat64ToTagged(node);
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef:
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef:
         return node;
-      default:
+      case wasm::ValueType::kStmt:
+      case wasm::ValueType::kBottom:
         UNREACHABLE();
     }
   }
@@ -5436,23 +5381,21 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* BuildTestSmi(Node* value) {
-    MachineOperatorBuilder* machine = mcgraph()->machine();
-    return graph()->NewNode(machine->Word32Equal(),
-                            graph()->NewNode(machine->Word32And(),
-                                             BuildTruncateIntPtrToInt32(value),
-                                             Int32Constant(kSmiTagMask)),
-                            Int32Constant(0));
+    return gasm_->Word32Equal(
+        gasm_->Word32And(BuildTruncateIntPtrToInt32(value),
+                         gasm_->Int32Constant(kSmiTagMask)),
+        gasm_->Int32Constant(0));
   }
 
   Node* BuildFloat64ToWasm(Node* value, wasm::ValueType type) {
-    switch (type) {
-      case wasm::kWasmI32:
+    switch (type.kind()) {
+      case wasm::ValueType::kI32:
         return graph()->NewNode(mcgraph()->machine()->TruncateFloat64ToWord32(),
                                 value);
-      case wasm::kWasmF32:
+      case wasm::ValueType::kF32:
         return graph()->NewNode(
             mcgraph()->machine()->TruncateFloat64ToFloat32(), value);
-      case wasm::kWasmF64:
+      case wasm::ValueType::kF64:
         return value;
       default:
         UNREACHABLE();
@@ -5460,12 +5403,12 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* BuildSmiToWasm(Node* smi, wasm::ValueType type) {
-    switch (type) {
-      case wasm::kWasmI32:
+    switch (type.kind()) {
+      case wasm::ValueType::kI32:
         return BuildChangeSmiToInt32(smi);
-      case wasm::kWasmF32:
+      case wasm::ValueType::kF32:
         return BuildChangeSmiToFloat32(smi);
-      case wasm::kWasmF64:
+      case wasm::ValueType::kF64:
         return BuildChangeSmiToFloat64(smi);
       default:
         UNREACHABLE();
@@ -5473,12 +5416,12 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* FromJS(Node* input, Node* js_context, wasm::ValueType type) {
-    switch (type) {
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmExnRef:
+    switch (type.kind()) {
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kExnRef:
         return input;
 
-      case wasm::kWasmNullRef: {
+      case wasm::ValueType::kNullRef: {
         Node* check = graph()->NewNode(mcgraph()->machine()->WordEqual(), input,
                                        RefNull());
 
@@ -5497,7 +5440,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         return input;
       }
 
-      case wasm::kWasmFuncRef: {
+      case wasm::ValueType::kFuncRef: {
         Node* check =
             BuildChangeSmiToInt32(SetEffect(BuildCallToRuntimeWithContext(
                 Runtime::kWasmIsValidFuncRefValue, js_context, &input, 1)));
@@ -5517,7 +5460,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         return input;
       }
 
-      case wasm::kWasmI64:
+      case wasm::ValueType::kI64:
         // i64 values can only come from BigInt.
         DCHECK(enabled_features_.has_bigint());
         return BuildChangeBigIntToInt64(input, js_context);
@@ -5534,25 +5477,26 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
 
     // Build a graph implementing this diagram:
     //   input smi?
-    //    ├─ true: ───────────────────────┬─ smi-to-wasm ──────┬─ result
+    //    ├─ true: ──<fast path>──────────┬─ smi-to-wasm ──────┬─ result
     //    └─ false: ToNumber -> smi?      │                    │
     //                          ├─ true: ─┘                    │
     //                          └─ false: load -> f64-to-wasm ─┘
 
     auto smi_to_wasm = gasm_->MakeLabel(MachineRepresentation::kTaggedSigned);
-    auto done =
-        gasm_->MakeLabel(wasm::ValueTypes::MachineRepresentationFor(type));
+    auto call_to_number =
+        gasm_->MakeDeferredLabel(MachineRepresentation::kTaggedPointer);
+    auto done = gasm_->MakeLabel(type.machine_representation());
 
-    // If the input is Smi, directly convert to the wasm type.
-    gasm_->GotoIf(BuildTestSmi(input), &smi_to_wasm, input);
+    // Branch to smi conversion or the ToNumber call.
+    gasm_->Branch(BuildTestSmi(input), &smi_to_wasm, &call_to_number, input);
 
-    // Otherwise, call ToNumber which returns a Smi or HeapNumber.
+    // Build the ToNumber path.
+    gasm_->Bind(&call_to_number);
     auto to_number_descriptor = Linkage::GetStubCallDescriptor(
         mcgraph()->zone(), TypeConversionDescriptor{}, 0,
         CallDescriptor::kNoFlags, Operator::kNoProperties, stub_mode_);
     Node* to_number_target =
         GetTargetForBuiltinCall(wasm::WasmCode::kToNumber, Builtins::kToNumber);
-
     Node* number =
         gasm_->Call(to_number_descriptor, to_number_target, input, js_context);
     SetSourcePosition(number, 1);
@@ -5567,7 +5511,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         BuildFloat64ToWasm(heap_number_value, type);
     gasm_->Goto(&done, converted_heap_number_value);
 
-    // Now implement the smi to wasm conversion.
+    // Implement the smi to wasm conversion.
     gasm_->Bind(&smi_to_wasm);
     Node* smi_to_wasm_result = BuildSmiToWasm(smi_to_wasm.PhiAt(0), type);
     gasm_->Goto(&done, smi_to_wasm_result);
@@ -5582,8 +5526,8 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     Node* isolate_root = BuildLoadIsolateRoot();
 
     Node* thread_in_wasm_flag_address =
-        LOAD_RAW(isolate_root, Isolate::thread_in_wasm_flag_address_offset(),
-                 MachineType::Pointer());
+        gasm_->Load(MachineType::Pointer(), isolate_root,
+                    Isolate::thread_in_wasm_flag_address_offset());
 
     if (FLAG_debug_code) {
       Node* flag_value = SetEffect(
@@ -5619,35 +5563,32 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   }
 
   Node* BuildLoadFunctionDataFromExportedFunction(Node* closure) {
-    Node* shared = LOAD_RAW(
-        closure,
-        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction(),
-        MachineType::AnyTagged());
-    return LOAD_RAW(shared,
-                    SharedFunctionInfo::kFunctionDataOffset - kHeapObjectTag,
-                    MachineType::AnyTagged());
+    Node* shared = gasm_->Load(
+        MachineType::AnyTagged(), closure,
+        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction());
+    return gasm_->Load(
+        MachineType::AnyTagged(), shared,
+        SharedFunctionInfo::kFunctionDataOffset - kHeapObjectTag);
   }
 
   Node* BuildLoadInstanceFromExportedFunctionData(Node* function_data) {
-    return LOAD_RAW(function_data,
-                    WasmExportedFunctionData::kInstanceOffset - kHeapObjectTag,
-                    MachineType::AnyTagged());
+    return gasm_->Load(
+        MachineType::AnyTagged(), function_data,
+        WasmExportedFunctionData::kInstanceOffset - kHeapObjectTag);
   }
 
   Node* BuildLoadFunctionIndexFromExportedFunctionData(Node* function_data) {
-    Node* function_index_smi = LOAD_RAW(
-        function_data,
-        WasmExportedFunctionData::kFunctionIndexOffset - kHeapObjectTag,
-        MachineType::TaggedSigned());
+    Node* function_index_smi = gasm_->Load(
+        MachineType::TaggedSigned(), function_data,
+        WasmExportedFunctionData::kFunctionIndexOffset - kHeapObjectTag);
     Node* function_index = BuildChangeSmiToInt32(function_index_smi);
     return function_index;
   }
 
   Node* BuildLoadJumpTableOffsetFromExportedFunctionData(Node* function_data) {
-    Node* jump_table_offset_smi = LOAD_RAW(
-        function_data,
-        WasmExportedFunctionData::kJumpTableOffsetOffset - kHeapObjectTag,
-        MachineType::TaggedSigned());
+    Node* jump_table_offset_smi = gasm_->Load(
+        MachineType::TaggedSigned(), function_data,
+        WasmExportedFunctionData::kJumpTableOffsetOffset - kHeapObjectTag);
     Node* jump_table_offset = BuildChangeSmiToIntPtr(jump_table_offset_smi);
     return jump_table_offset;
   }
@@ -5768,14 +5709,12 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   Node* BuildReceiverNode(Node* callable_node, Node* native_context,
                           Node* undefined_node) {
     // Check function strict bit.
-    Node* shared_function_info = LOAD_RAW(
-        callable_node,
-        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction(),
-        MachineType::TaggedPointer());
+    Node* shared_function_info = gasm_->Load(
+        MachineType::TaggedPointer(), callable_node,
+        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction());
     Node* flags =
-        LOAD_RAW(shared_function_info,
-                 wasm::ObjectAccess::FlagsOffsetInSharedFunctionInfo(),
-                 MachineType::Int32());
+        gasm_->Load(MachineType::Int32(), shared_function_info,
+                    wasm::ObjectAccess::FlagsOffsetInSharedFunctionInfo());
     Node* strict_check =
         Binop(wasm::kExprI32And, flags,
               mcgraph()->Int32Constant(SharedFunctionInfo::IsNativeBit::kMask |
@@ -5815,7 +5754,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       return false;
     }
 
-    // The callable is passed as the last parameter, after WASM arguments.
+    // The callable is passed as the last parameter, after Wasm arguments.
     Node* callable_node = Param(wasm_count + 1);
 
     Node* undefined_node = BuildLoadUndefinedValueFromInstance();
@@ -5833,9 +5772,8 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         base::SmallVector<Node*, 16> args(wasm_count + 7);
         int pos = 0;
         Node* function_context =
-            LOAD_RAW(callable_node,
-                     wasm::ObjectAccess::ContextOffsetInTaggedJSFunction(),
-                     MachineType::TaggedPointer());
+            gasm_->Load(MachineType::TaggedPointer(), callable_node,
+                        wasm::ObjectAccess::ContextOffsetInTaggedJSFunction());
         args[pos++] = callable_node;  // target callable.
 
         // Determine receiver at runtime.
@@ -5866,9 +5804,8 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         base::SmallVector<Node*, 16> args(wasm_count + 9);
         int pos = 0;
         Node* function_context =
-            LOAD_RAW(callable_node,
-                     wasm::ObjectAccess::ContextOffsetInTaggedJSFunction(),
-                     MachineType::TaggedPointer());
+            gasm_->Load(MachineType::TaggedPointer(), callable_node,
+                        wasm::ObjectAccess::ContextOffsetInTaggedJSFunction());
         args[pos++] = mcgraph()->RelocatableIntPtrConstant(
             wasm::WasmCode::kArgumentsAdaptorTrampoline,
             RelocInfo::WASM_STUB_CALL);
@@ -5877,10 +5814,9 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
         args[pos++] = mcgraph()->Int32Constant(wasm_count);  // argument count
 
         // Load shared function info, and then the formal parameter count.
-        Node* shared_function_info = LOAD_RAW(
-            callable_node,
-            wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction(),
-            MachineType::TaggedPointer());
+        Node* shared_function_info = gasm_->Load(
+            MachineType::TaggedPointer(), callable_node,
+            wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction());
         Node* formal_param_count = SetEffect(graph()->NewNode(
             mcgraph()->machine()->Load(MachineType::Uint16()),
             shared_function_info,
@@ -5978,11 +5914,11 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     // Store arguments on our stack, then align the stack for calling to C.
     int param_bytes = 0;
     for (wasm::ValueType type : sig_->parameters()) {
-      param_bytes += wasm::ValueTypes::MemSize(type);
+      param_bytes += type.element_size_bytes();
     }
     int return_bytes = 0;
     for (wasm::ValueType type : sig_->returns()) {
-      return_bytes += wasm::ValueTypes::MemSize(type);
+      return_bytes += type.element_size_bytes();
     }
 
     int stack_slot_bytes = std::max(param_bytes, return_bytes);
@@ -6001,20 +5937,19 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       SetEffect(graph()->NewNode(GetSafeStoreOperator(offset, type), values,
                                  Int32Constant(offset), Param(i + 1), effect(),
                                  control()));
-      offset += wasm::ValueTypes::ElementSizeInBytes(type);
+      offset += type.element_size_bytes();
     }
-    // The function is passed as the last parameter, after WASM arguments.
+    // The function is passed as the last parameter, after Wasm arguments.
     Node* function_node = Param(param_count + 1);
-    Node* shared = LOAD_RAW(
-        function_node,
-        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction(),
-        MachineType::AnyTagged());
-    Node* sfi_data = LOAD_RAW(
-        shared, SharedFunctionInfo::kFunctionDataOffset - kHeapObjectTag,
-        MachineType::AnyTagged());
-    Node* host_data_foreign = LOAD_RAW(
-        sfi_data, WasmCapiFunctionData::kEmbedderDataOffset - kHeapObjectTag,
-        MachineType::AnyTagged());
+    Node* shared = gasm_->Load(
+        MachineType::AnyTagged(), function_node,
+        wasm::ObjectAccess::SharedFunctionInfoOffsetInTaggedJSFunction());
+    Node* sfi_data =
+        gasm_->Load(MachineType::AnyTagged(), shared,
+                    SharedFunctionInfo::kFunctionDataOffset - kHeapObjectTag);
+    Node* host_data_foreign =
+        gasm_->Load(MachineType::AnyTagged(), sfi_data,
+                    WasmCapiFunctionData::kEmbedderDataOffset - kHeapObjectTag);
 
     BuildModifyThreadInWasmFlag(false);
     Node* isolate_root = BuildLoadIsolateRoot();
@@ -6071,7 +6006,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
             graph()->NewNode(GetSafeLoadOperator(offset, type), values,
                              Int32Constant(offset), effect(), control()));
         returns[i] = val;
-        offset += wasm::ValueTypes::ElementSizeInBytes(type);
+        offset += type.element_size_bytes();
       }
       Return(VectorOf(returns));
     }
@@ -6091,13 +6026,13 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     // Compute size for the argument buffer.
     int args_size_bytes = 0;
     for (wasm::ValueType type : sig_->parameters()) {
-      args_size_bytes += wasm::ValueTypes::ElementSizeInBytes(type);
+      args_size_bytes += type.element_size_bytes();
     }
 
     // The return value is also passed via this buffer:
     int return_size_bytes = 0;
     for (wasm::ValueType type : sig_->returns()) {
-      return_size_bytes += wasm::ValueTypes::ElementSizeInBytes(type);
+      return_size_bytes += type.element_size_bytes();
     }
 
     // Get a stack slot for the arguments.
@@ -6116,7 +6051,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       SetEffect(graph()->NewNode(GetSafeStoreOperator(offset, type), arg_buffer,
                                  Int32Constant(offset), Param(i + 1), effect(),
                                  control()));
-      offset += wasm::ValueTypes::ElementSizeInBytes(type);
+      offset += type.element_size_bytes();
     }
     DCHECK_EQ(args_size_bytes, offset);
 
@@ -6143,7 +6078,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
             graph()->NewNode(GetSafeLoadOperator(offset, type), arg_buffer,
                              Int32Constant(offset), effect(), control()));
         returns[i] = val;
-        offset += wasm::ValueTypes::ElementSizeInBytes(type);
+        offset += type.element_size_bytes();
       }
       Return(VectorOf(returns));
     }
@@ -6267,7 +6202,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
           graph()->NewNode(GetSafeLoadOperator(offset, type), arg_buffer,
                            Int32Constant(offset), effect(), control()));
       args[pos++] = arg_load;
-      offset += wasm::ValueTypes::ElementSizeInBytes(type);
+      offset += type.element_size_bytes();
     }
 
     args[pos++] = effect();
@@ -6300,7 +6235,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
       SetEffect(graph()->NewNode(GetSafeStoreOperator(offset, type), arg_buffer,
                                  Int32Constant(offset), value, effect(),
                                  control()));
-      offset += wasm::ValueTypes::ElementSizeInBytes(type);
+      offset += type.element_size_bytes();
       pos++;
     }
 
@@ -6329,27 +6264,31 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
   SetOncePointer<Node> undefined_value_node_;
   SetOncePointer<const Operator> allocate_heap_number_operator_;
   wasm::WasmFeatures enabled_features_;
+  CallDescriptor* bigint_to_i64_descriptor_ = nullptr;
+  CallDescriptor* i64_to_bigint_descriptor_ = nullptr;
 };
 
 }  // namespace
 
 std::unique_ptr<OptimizedCompilationJob> NewJSToWasmCompilationJob(
-    Isolate* isolate, wasm::WasmEngine* wasm_engine, wasm::FunctionSig* sig,
-    bool is_import, const wasm::WasmFeatures& enabled_features) {
+    Isolate* isolate, wasm::WasmEngine* wasm_engine,
+    const wasm::FunctionSig* sig, bool is_import,
+    const wasm::WasmFeatures& enabled_features) {
   //----------------------------------------------------------------------------
   // Create the Graph.
   //----------------------------------------------------------------------------
   std::unique_ptr<Zone> zone =
       std::make_unique<Zone>(wasm_engine->allocator(), ZONE_NAME);
   Graph* graph = new (zone.get()) Graph(zone.get());
-  CommonOperatorBuilder common(zone.get());
-  MachineOperatorBuilder machine(
+  CommonOperatorBuilder* common =
+      new (zone.get()) CommonOperatorBuilder(zone.get());
+  MachineOperatorBuilder* machine = new (zone.get()) MachineOperatorBuilder(
       zone.get(), MachineType::PointerRepresentation(),
       InstructionSelector::SupportedMachineOperatorFlags(),
       InstructionSelector::AlignmentRequirements());
-  MachineGraph mcgraph(graph, &common, &machine);
+  MachineGraph* mcgraph = new (zone.get()) MachineGraph(graph, common, machine);
 
-  WasmWrapperGraphBuilder builder(zone.get(), &mcgraph, sig, nullptr,
+  WasmWrapperGraphBuilder builder(zone.get(), mcgraph, sig, nullptr,
                                   StubCallMode::kCallBuiltinPointer,
                                   enabled_features);
   builder.BuildJSToWasmWrapper(is_import);
@@ -6375,13 +6314,13 @@ std::unique_ptr<OptimizedCompilationJob> NewJSToWasmCompilationJob(
 }
 
 std::pair<WasmImportCallKind, Handle<JSReceiver>> ResolveWasmImportCall(
-    Handle<JSReceiver> callable, wasm::FunctionSig* expected_sig,
+    Handle<JSReceiver> callable, const wasm::FunctionSig* expected_sig,
     const wasm::WasmFeatures& enabled_features) {
   if (WasmExportedFunction::IsWasmExportedFunction(*callable)) {
     auto imported_function = Handle<WasmExportedFunction>::cast(callable);
     auto func_index = imported_function->function_index();
     auto module = imported_function->instance().module();
-    wasm::FunctionSig* imported_sig = module->functions[func_index].sig;
+    const wasm::FunctionSig* imported_sig = module->functions[func_index].sig;
     if (*imported_sig != *expected_sig) {
       return std::make_pair(WasmImportCallKind::kLinkError, callable);
     }
@@ -6420,14 +6359,15 @@ std::pair<WasmImportCallKind, Handle<JSReceiver>> ResolveWasmImportCall(
     SharedFunctionInfo shared = function->shared();
 
 // Check for math intrinsics.
-#define COMPARE_SIG_FOR_BUILTIN(name)                                         \
-  {                                                                           \
-    wasm::FunctionSig* sig = wasm::WasmOpcodes::Signature(wasm::kExpr##name); \
-    if (!sig) sig = wasm::WasmOpcodes::AsmjsSignature(wasm::kExpr##name);     \
-    DCHECK_NOT_NULL(sig);                                                     \
-    if (*expected_sig == *sig) {                                              \
-      return std::make_pair(WasmImportCallKind::k##name, callable);           \
-    }                                                                         \
+#define COMPARE_SIG_FOR_BUILTIN(name)                                     \
+  {                                                                       \
+    const wasm::FunctionSig* sig =                                        \
+        wasm::WasmOpcodes::Signature(wasm::kExpr##name);                  \
+    if (!sig) sig = wasm::WasmOpcodes::AsmjsSignature(wasm::kExpr##name); \
+    DCHECK_NOT_NULL(sig);                                                 \
+    if (*expected_sig == *sig) {                                          \
+      return std::make_pair(WasmImportCallKind::k##name, callable);       \
+    }                                                                     \
   }
 #define COMPARE_SIG_FOR_BUILTIN_F64(name) \
   case Builtins::kMath##name:             \
@@ -6524,7 +6464,7 @@ wasm::WasmOpcode GetMathIntrinsicOpcode(WasmImportCallKind kind,
 
 wasm::WasmCompilationResult CompileWasmMathIntrinsic(
     wasm::WasmEngine* wasm_engine, WasmImportCallKind kind,
-    wasm::FunctionSig* sig) {
+    const wasm::FunctionSig* sig) {
   DCHECK_EQ(1, sig->return_count());
 
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"),
@@ -6532,7 +6472,7 @@ wasm::WasmCompilationResult CompileWasmMathIntrinsic(
 
   Zone zone(wasm_engine->allocator(), ZONE_NAME);
 
-  // Compile a WASM function with a single bytecode and let TurboFan
+  // Compile a Wasm function with a single bytecode and let TurboFan
   // generate either inlined machine code or a call to a helper.
   SourcePositionTable* source_positions = nullptr;
   MachineGraph* mcgraph = new (&zone) MachineGraph(
@@ -6587,7 +6527,8 @@ wasm::WasmCompilationResult CompileWasmMathIntrinsic(
 
 wasm::WasmCompilationResult CompileWasmImportCallWrapper(
     wasm::WasmEngine* wasm_engine, wasm::CompilationEnv* env,
-    WasmImportCallKind kind, wasm::FunctionSig* sig, bool source_positions) {
+    WasmImportCallKind kind, const wasm::FunctionSig* sig,
+    bool source_positions) {
   DCHECK_NE(WasmImportCallKind::kLinkError, kind);
   DCHECK_NE(WasmImportCallKind::kWasmToWasm, kind);
 
@@ -6604,18 +6545,18 @@ wasm::WasmCompilationResult CompileWasmImportCallWrapper(
   // Create the Graph
   //----------------------------------------------------------------------------
   Zone zone(wasm_engine->allocator(), ZONE_NAME);
-  Graph graph(&zone);
-  CommonOperatorBuilder common(&zone);
-  MachineOperatorBuilder machine(
+  Graph* graph = new (&zone) Graph(&zone);
+  CommonOperatorBuilder* common = new (&zone) CommonOperatorBuilder(&zone);
+  MachineOperatorBuilder* machine = new (&zone) MachineOperatorBuilder(
       &zone, MachineType::PointerRepresentation(),
       InstructionSelector::SupportedMachineOperatorFlags(),
       InstructionSelector::AlignmentRequirements());
-  MachineGraph mcgraph(&graph, &common, &machine);
+  MachineGraph* mcgraph = new (&zone) MachineGraph(graph, common, machine);
 
   SourcePositionTable* source_position_table =
-      source_positions ? new (&zone) SourcePositionTable(&graph) : nullptr;
+      source_positions ? new (&zone) SourcePositionTable(graph) : nullptr;
 
-  WasmWrapperGraphBuilder builder(&zone, &mcgraph, sig, source_position_table,
+  WasmWrapperGraphBuilder builder(&zone, mcgraph, sig, source_position_table,
                                   StubCallMode::kCallWasmRuntimeStub,
                                   env->enabled_features);
   builder.BuildWasmImportCallWrapper(kind);
@@ -6626,11 +6567,11 @@ wasm::WasmCompilationResult CompileWasmImportCallWrapper(
   CallDescriptor* incoming =
       GetWasmCallDescriptor(&zone, sig, WasmGraphBuilder::kNoRetpoline,
                             WasmCallKind::kWasmImportWrapper);
-  if (machine.Is32()) {
+  if (machine->Is32()) {
     incoming = GetI32WasmCallDescriptor(&zone, incoming);
   }
   wasm::WasmCompilationResult result = Pipeline::GenerateCodeForWasmNativeStub(
-      wasm_engine, incoming, &mcgraph, Code::WASM_TO_JS_FUNCTION,
+      wasm_engine, incoming, mcgraph, Code::WASM_TO_JS_FUNCTION,
       wasm::WasmCode::kWasmToJsWrapper, func_name, WasmStubAssemblerOptions(),
       source_position_table);
   result.kind = wasm::WasmCompilationResult::kWasmToJsWrapper;
@@ -6639,7 +6580,7 @@ wasm::WasmCompilationResult CompileWasmImportCallWrapper(
 
 wasm::WasmCode* CompileWasmCapiCallWrapper(wasm::WasmEngine* wasm_engine,
                                            wasm::NativeModule* native_module,
-                                           wasm::FunctionSig* sig,
+                                           const wasm::FunctionSig* sig,
                                            Address address) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), "CompileWasmCapiFunction");
 
@@ -6682,35 +6623,36 @@ wasm::WasmCode* CompileWasmCapiCallWrapper(wasm::WasmEngine* wasm_engine,
       WasmStubAssemblerOptions(), source_positions);
   std::unique_ptr<wasm::WasmCode> wasm_code = native_module->AddCode(
       wasm::kAnonymousFuncIndex, result.code_desc, result.frame_slot_count,
-      result.tagged_parameter_slots, std::move(result.protected_instructions),
-      std::move(result.source_positions), wasm::WasmCode::kWasmToCapiWrapper,
+      result.tagged_parameter_slots,
+      result.protected_instructions_data.as_vector(),
+      result.source_positions.as_vector(), wasm::WasmCode::kWasmToCapiWrapper,
       wasm::ExecutionTier::kNone);
   return native_module->PublishCode(std::move(wasm_code));
 }
 
 wasm::WasmCompilationResult CompileWasmInterpreterEntry(
     wasm::WasmEngine* wasm_engine, const wasm::WasmFeatures& enabled_features,
-    uint32_t func_index, wasm::FunctionSig* sig) {
+    uint32_t func_index, const wasm::FunctionSig* sig) {
   //----------------------------------------------------------------------------
   // Create the Graph
   //----------------------------------------------------------------------------
   Zone zone(wasm_engine->allocator(), ZONE_NAME);
-  Graph graph(&zone);
-  CommonOperatorBuilder common(&zone);
-  MachineOperatorBuilder machine(
+  Graph* graph = new (&zone) Graph(&zone);
+  CommonOperatorBuilder* common = new (&zone) CommonOperatorBuilder(&zone);
+  MachineOperatorBuilder* machine = new (&zone) MachineOperatorBuilder(
       &zone, MachineType::PointerRepresentation(),
       InstructionSelector::SupportedMachineOperatorFlags(),
       InstructionSelector::AlignmentRequirements());
-  MachineGraph mcgraph(&graph, &common, &machine);
+  MachineGraph* mcgraph = new (&zone) MachineGraph(graph, common, machine);
 
-  WasmWrapperGraphBuilder builder(&zone, &mcgraph, sig, nullptr,
+  WasmWrapperGraphBuilder builder(&zone, mcgraph, sig, nullptr,
                                   StubCallMode::kCallWasmRuntimeStub,
                                   enabled_features);
   builder.BuildWasmInterpreterEntry(func_index);
 
   // Schedule and compile to machine code.
   CallDescriptor* incoming = GetWasmCallDescriptor(&zone, sig);
-  if (machine.Is32()) {
+  if (machine->Is32()) {
     incoming = GetI32WasmCallDescriptor(&zone, incoming);
   }
 
@@ -6719,7 +6661,7 @@ wasm::WasmCompilationResult CompileWasmInterpreterEntry(
       SNPrintF(func_name, "wasm-interpreter-entry#%d", func_index));
 
   wasm::WasmCompilationResult result = Pipeline::GenerateCodeForWasmNativeStub(
-      wasm_engine, incoming, &mcgraph, Code::WASM_INTERPRETER_ENTRY,
+      wasm_engine, incoming, mcgraph, Code::WASM_INTERPRETER_ENTRY,
       wasm::WasmCode::kInterpreterEntry, func_name.begin(),
       WasmStubAssemblerOptions());
   result.result_tier = wasm::ExecutionTier::kInterpreter;
@@ -6729,18 +6671,19 @@ wasm::WasmCompilationResult CompileWasmInterpreterEntry(
 }
 
 MaybeHandle<Code> CompileJSToJSWrapper(Isolate* isolate,
-                                       wasm::FunctionSig* sig) {
+                                       const wasm::FunctionSig* sig) {
   std::unique_ptr<Zone> zone =
       std::make_unique<Zone>(isolate->allocator(), ZONE_NAME);
   Graph* graph = new (zone.get()) Graph(zone.get());
-  CommonOperatorBuilder common(zone.get());
-  MachineOperatorBuilder machine(
+  CommonOperatorBuilder* common =
+      new (zone.get()) CommonOperatorBuilder(zone.get());
+  MachineOperatorBuilder* machine = new (zone.get()) MachineOperatorBuilder(
       zone.get(), MachineType::PointerRepresentation(),
       InstructionSelector::SupportedMachineOperatorFlags(),
       InstructionSelector::AlignmentRequirements());
-  MachineGraph mcgraph(graph, &common, &machine);
+  MachineGraph* mcgraph = new (zone.get()) MachineGraph(graph, common, machine);
 
-  WasmWrapperGraphBuilder builder(zone.get(), &mcgraph, sig, nullptr,
+  WasmWrapperGraphBuilder builder(zone.get(), mcgraph, sig, nullptr,
                                   StubCallMode::kCallBuiltinPointer,
                                   wasm::WasmFeatures::FromIsolate(isolate));
   builder.BuildJSToJSWrapper(isolate);
@@ -6774,18 +6717,20 @@ MaybeHandle<Code> CompileJSToJSWrapper(Isolate* isolate,
   return code;
 }
 
-MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate, wasm::FunctionSig* sig) {
+MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate,
+                                    const wasm::FunctionSig* sig) {
   std::unique_ptr<Zone> zone =
       std::make_unique<Zone>(isolate->allocator(), ZONE_NAME);
   Graph* graph = new (zone.get()) Graph(zone.get());
-  CommonOperatorBuilder common(zone.get());
-  MachineOperatorBuilder machine(
+  CommonOperatorBuilder* common =
+      new (zone.get()) CommonOperatorBuilder(zone.get());
+  MachineOperatorBuilder* machine = new (zone.get()) MachineOperatorBuilder(
       zone.get(), MachineType::PointerRepresentation(),
       InstructionSelector::SupportedMachineOperatorFlags(),
       InstructionSelector::AlignmentRequirements());
-  MachineGraph mcgraph(graph, &common, &machine);
+  MachineGraph* mcgraph = new (zone.get()) MachineGraph(graph, common, machine);
 
-  WasmWrapperGraphBuilder builder(zone.get(), &mcgraph, sig, nullptr,
+  WasmWrapperGraphBuilder builder(zone.get(), mcgraph, sig, nullptr,
                                   StubCallMode::kCallBuiltinPointer,
                                   wasm::WasmFeatures::FromIsolate(isolate));
   builder.BuildCWasmEntry();
@@ -7004,7 +6949,7 @@ class LinkageLocationAllocator {
 
 // General code uses the above configuration data.
 CallDescriptor* GetWasmCallDescriptor(
-    Zone* zone, wasm::FunctionSig* fsig,
+    Zone* zone, const wasm::FunctionSig* fsig,
     WasmGraphBuilder::UseRetpoline use_retpoline, WasmCallKind call_kind) {
   // The extra here is to accomodate the instance object as first parameter
   // and, when specified, the additional callable.
@@ -7027,16 +6972,14 @@ CallDescriptor* GetWasmCallDescriptor(
   // during frame iteration.
   const size_t parameter_count = fsig->parameter_count();
   for (size_t i = 0; i < parameter_count; i++) {
-    MachineRepresentation param =
-        wasm::ValueTypes::MachineRepresentationFor(fsig->GetParam(i));
+    MachineRepresentation param = fsig->GetParam(i).machine_representation();
     // Skip tagged parameters (e.g. any-ref).
     if (IsAnyTagged(param)) continue;
     auto l = params.Next(param);
     locations.AddParamAt(i + param_offset, l);
   }
   for (size_t i = 0; i < parameter_count; i++) {
-    MachineRepresentation param =
-        wasm::ValueTypes::MachineRepresentationFor(fsig->GetParam(i));
+    MachineRepresentation param = fsig->GetParam(i).machine_representation();
     // Skip untagged parameters.
     if (!IsAnyTagged(param)) continue;
     auto l = params.Next(param);
@@ -7061,8 +7004,7 @@ CallDescriptor* GetWasmCallDescriptor(
 
   const int return_count = static_cast<int>(locations.return_count_);
   for (int i = 0; i < return_count; i++) {
-    MachineRepresentation ret =
-        wasm::ValueTypes::MachineRepresentationFor(fsig->GetReturn(i));
+    MachineRepresentation ret = fsig->GetReturn(i).machine_representation();
     auto l = rets.Next(ret);
     locations.AddReturn(l);
   }
@@ -7210,12 +7152,9 @@ AssemblerOptions WasmStubAssemblerOptions() {
   return options;
 }
 
-#undef WASM_64
 #undef FATAL_UNSUPPORTED_OPCODE
 #undef WASM_INSTANCE_OBJECT_SIZE
 #undef WASM_INSTANCE_OBJECT_OFFSET
-#undef LOAD_RAW
-#undef LOAD_RAW_NODE_OFFSET
 #undef LOAD_INSTANCE_FIELD
 #undef LOAD_TAGGED_POINTER
 #undef LOAD_TAGGED_ANY
diff --git a/deps/v8/src/compiler/wasm-compiler.h b/deps/v8/src/compiler/wasm-compiler.h
index 7782ebfdec..176fdb63c4 100644
--- a/deps/v8/src/compiler/wasm-compiler.h
+++ b/deps/v8/src/compiler/wasm-compiler.h
@@ -58,16 +58,16 @@ wasm::WasmCompilationResult ExecuteInterpreterEntryCompilation(
     wasm::WasmEngine*, wasm::CompilationEnv*, const wasm::FunctionBody&,
     int func_index, Counters*, wasm::WasmFeatures* detected);
 
-// Calls to WASM imports are handled in several different ways, depending on the
+// Calls to Wasm imports are handled in several different ways, depending on the
 // type of the target function/callable and whether the signature matches the
 // argument arity.
 enum class WasmImportCallKind : uint8_t {
-  kLinkError,                      // static WASM->WASM type error
-  kRuntimeTypeError,               // runtime WASM->JS type error
-  kWasmToCapi,                     // fast WASM->C-API call
-  kWasmToWasm,                     // fast WASM->WASM call
-  kJSFunctionArityMatch,           // fast WASM->JS call
-  kJSFunctionArityMismatch,        // WASM->JS, needs adapter frame
+  kLinkError,                // static Wasm->Wasm type error
+  kRuntimeTypeError,         // runtime Wasm->JS type error
+  kWasmToCapi,               // fast Wasm->C-API call
+  kWasmToWasm,               // fast Wasm->Wasm call
+  kJSFunctionArityMatch,     // fast Wasm->JS call
+  kJSFunctionArityMismatch,  // Wasm->JS, needs adapter frame
   // Math functions imported from JavaScript that are intrinsified
   kFirstMathIntrinsic,
   kF64Acos = kFirstMathIntrinsic,
@@ -106,35 +106,36 @@ constexpr WasmImportCallKind kDefaultImportCallKind =
 // some callables (e.g. a {WasmExportedFunction} or {WasmJSFunction}) just wrap
 // another target, which is why the ultimate target is returned as well.
 V8_EXPORT_PRIVATE std::pair<WasmImportCallKind, Handle<JSReceiver>>
-ResolveWasmImportCall(Handle<JSReceiver> callable, wasm::FunctionSig* sig,
+ResolveWasmImportCall(Handle<JSReceiver> callable, const wasm::FunctionSig* sig,
                       const wasm::WasmFeatures& enabled_features);
 
-// Compiles an import call wrapper, which allows WASM to call imports.
+// Compiles an import call wrapper, which allows Wasm to call imports.
 V8_EXPORT_PRIVATE wasm::WasmCompilationResult CompileWasmImportCallWrapper(
     wasm::WasmEngine*, wasm::CompilationEnv* env, WasmImportCallKind,
-    wasm::FunctionSig*, bool source_positions);
+    const wasm::FunctionSig*, bool source_positions);
 
-// Compiles a host call wrapper, which allows WASM to call host functions.
+// Compiles a host call wrapper, which allows Wasm to call host functions.
 wasm::WasmCode* CompileWasmCapiCallWrapper(wasm::WasmEngine*,
                                            wasm::NativeModule*,
-                                           wasm::FunctionSig*, Address address);
+                                           const wasm::FunctionSig*,
+                                           Address address);
 
 // Returns an OptimizedCompilationJob object for a JS to Wasm wrapper.
 std::unique_ptr<OptimizedCompilationJob> NewJSToWasmCompilationJob(
-    Isolate* isolate, wasm::WasmEngine* wasm_engine, wasm::FunctionSig* sig,
-    bool is_import, const wasm::WasmFeatures& enabled_features);
+    Isolate* isolate, wasm::WasmEngine* wasm_engine,
+    const wasm::FunctionSig* sig, bool is_import,
+    const wasm::WasmFeatures& enabled_features);
 
 // Compiles a stub that redirects a call to a wasm function to the wasm
 // interpreter. It's ABI compatible with the compiled wasm function.
 V8_EXPORT_PRIVATE wasm::WasmCompilationResult CompileWasmInterpreterEntry(
     wasm::WasmEngine*, const wasm::WasmFeatures& enabled_features,
-    uint32_t func_index, wasm::FunctionSig*);
+    uint32_t func_index, const wasm::FunctionSig*);
 
 // Compiles a stub with JS linkage that serves as an adapter for function
 // objects constructed via {WebAssembly.Function}. It performs a round-trip
 // simulating a JS-to-Wasm-to-JS coercion of parameter and return values.
-MaybeHandle<Code> CompileJSToJSWrapper(Isolate* isolate,
-                                       wasm::FunctionSig* sig);
+MaybeHandle<Code> CompileJSToJSWrapper(Isolate*, const wasm::FunctionSig*);
 
 enum CWasmEntryParameters {
   kCodeEntry,
@@ -147,11 +148,11 @@ enum CWasmEntryParameters {
 
 // Compiles a stub with C++ linkage, to be called from Execution::CallWasm,
 // which knows how to feed it its parameters.
-MaybeHandle<Code> CompileCWasmEntry(Isolate* isolate, wasm::FunctionSig* sig);
+MaybeHandle<Code> CompileCWasmEntry(Isolate*, const wasm::FunctionSig*);
 
-// Values from the instance object are cached between WASM-level function calls.
+// Values from the instance object are cached between Wasm-level function calls.
 // This struct allows the SSA environment handling this cache to be defined
-// and manipulated in wasm-compiler.{h,cc} instead of inside the WASM decoder.
+// and manipulated in wasm-compiler.{h,cc} instead of inside the Wasm decoder.
 // (Note that currently, the globals base is immutable, so not cached here.)
 struct WasmInstanceCacheNodes {
   Node* mem_start;
@@ -174,7 +175,8 @@ class WasmGraphBuilder {
 
   V8_EXPORT_PRIVATE WasmGraphBuilder(
       wasm::CompilationEnv* env, Zone* zone, MachineGraph* mcgraph,
-      wasm::FunctionSig* sig, compiler::SourcePositionTable* spt = nullptr);
+      const wasm::FunctionSig* sig,
+      compiler::SourcePositionTable* spt = nullptr);
 
   V8_EXPORT_PRIVATE ~WasmGraphBuilder();
 
@@ -211,7 +213,7 @@ class WasmGraphBuilder {
   Node* Rethrow(Node* except_obj);
   Node* ExceptionTagEqual(Node* caught_tag, Node* expected_tag);
   Node* LoadExceptionTagFromTable(uint32_t exception_index);
-  Node* GetExceptionTag(Node* except_obj);
+  Node* GetExceptionTag(Node* except_obj, wasm::WasmCodePosition);
   Node* GetExceptionValues(Node* except_obj,
                            const wasm::WasmException* exception,
                            Vector<Node*> values_out);
@@ -283,7 +285,12 @@ class WasmGraphBuilder {
   Node* LoadMem(wasm::ValueType type, MachineType memtype, Node* index,
                 uint32_t offset, uint32_t alignment,
                 wasm::WasmCodePosition position);
-  Node* LoadTransform(MachineType memtype,
+#if defined(V8_TARGET_BIG_ENDIAN) || defined(V8_TARGET_ARCH_S390_LE_SIM)
+  Node* LoadTransformBigEndian(MachineType memtype,
+                               wasm::LoadTransformationKind transform,
+                               Node* value);
+#endif
+  Node* LoadTransform(wasm::ValueType type, MachineType memtype,
                       wasm::LoadTransformationKind transform, Node* index,
                       uint32_t offset, uint32_t alignment,
                       wasm::WasmCodePosition position);
@@ -335,7 +342,7 @@ class WasmGraphBuilder {
     this->instance_cache_ = instance_cache;
   }
 
-  wasm::FunctionSig* GetFunctionSignature() { return sig_; }
+  const wasm::FunctionSig* GetFunctionSignature() { return sig_; }
 
   enum CallOrigin { kCalledFromWasm, kCalledFromJS };
 
@@ -430,7 +437,7 @@ class WasmGraphBuilder {
 
   template <typename... Args>
   Node* BuildCCall(MachineSignature* sig, Node* function, Args... args);
-  Node* BuildCallNode(wasm::FunctionSig* sig, Vector<Node*> args,
+  Node* BuildCallNode(const wasm::FunctionSig* sig, Vector<Node*> args,
                       wasm::WasmCodePosition position, Node* instance_node,
                       const Operator* op);
   // Helper function for {BuildIndirectCall}.
@@ -441,16 +448,16 @@ class WasmGraphBuilder {
                           Vector<Node*> args, Vector<Node*> rets,
                           wasm::WasmCodePosition position,
                           IsReturnCall continuation);
-  Node* BuildWasmCall(wasm::FunctionSig* sig, Vector<Node*> args,
+  Node* BuildWasmCall(const wasm::FunctionSig* sig, Vector<Node*> args,
                       Vector<Node*> rets, wasm::WasmCodePosition position,
                       Node* instance_node, UseRetpoline use_retpoline);
-  Node* BuildWasmReturnCall(wasm::FunctionSig* sig, Vector<Node*> args,
+  Node* BuildWasmReturnCall(const wasm::FunctionSig* sig, Vector<Node*> args,
                             wasm::WasmCodePosition position,
                             Node* instance_node, UseRetpoline use_retpoline);
-  Node* BuildImportCall(wasm::FunctionSig* sig, Vector<Node*> args,
+  Node* BuildImportCall(const wasm::FunctionSig* sig, Vector<Node*> args,
                         Vector<Node*> rets, wasm::WasmCodePosition position,
                         int func_index, IsReturnCall continuation);
-  Node* BuildImportCall(wasm::FunctionSig* sig, Vector<Node*> args,
+  Node* BuildImportCall(const wasm::FunctionSig* sig, Vector<Node*> args,
                         Vector<Node*> rets, wasm::WasmCodePosition position,
                         Node* func_index, IsReturnCall continuation);
 
@@ -551,6 +558,16 @@ class WasmGraphBuilder {
                                       Node** parameters, int parameter_count);
   TrapId GetTrapIdForTrap(wasm::TrapReason reason);
 
+  void AddInt64LoweringReplacement(CallDescriptor* original,
+                                   CallDescriptor* replacement);
+
+  CallDescriptor* GetI32AtomicWaitCallDescriptor();
+
+  CallDescriptor* GetI64AtomicWaitCallDescriptor();
+
+  Node* StoreArgsInStackSlot(
+      std::initializer_list<std::pair<MachineRepresentation, Node*>> args);
+
   std::unique_ptr<WasmGraphAssembler> gasm_;
   Zone* const zone_;
   MachineGraph* const mcgraph_;
@@ -569,19 +586,21 @@ class WasmGraphBuilder {
   bool needs_stack_check_ = false;
   const bool untrusted_code_mitigations_ = true;
 
-  wasm::FunctionSig* const sig_;
+  const wasm::FunctionSig* const sig_;
 
   compiler::WasmDecorator* decorator_ = nullptr;
 
   compiler::SourcePositionTable* const source_position_table_ = nullptr;
 
   std::unique_ptr<Int64LoweringSpecialCase> lowering_special_case_;
+  CallDescriptor* i32_atomic_wait_descriptor_ = nullptr;
+  CallDescriptor* i64_atomic_wait_descriptor_ = nullptr;
 };
 
 enum WasmCallKind { kWasmFunction, kWasmImportWrapper, kWasmCapiFunction };
 
 V8_EXPORT_PRIVATE CallDescriptor* GetWasmCallDescriptor(
-    Zone* zone, wasm::FunctionSig* signature,
+    Zone* zone, const wasm::FunctionSig* signature,
     WasmGraphBuilder::UseRetpoline use_retpoline =
         WasmGraphBuilder::kNoRetpoline,
     WasmCallKind kind = kWasmFunction);
diff --git a/deps/v8/src/d8/OWNERS b/deps/v8/src/d8/OWNERS
index a548e5a509..d57b8cb779 100644
--- a/deps/v8/src/d8/OWNERS
+++ b/deps/v8/src/d8/OWNERS
@@ -1,4 +1,5 @@
 binji@chromium.org
 bmeurer@chromium.org
 clemensb@chromium.org
+ulan@chromium.org
 verwaest@chromium.org
diff --git a/deps/v8/src/d8/async-hooks-wrapper.cc b/deps/v8/src/d8/async-hooks-wrapper.cc
index cb00dd521a..f96aad4123 100644
--- a/deps/v8/src/d8/async-hooks-wrapper.cc
+++ b/deps/v8/src/d8/async-hooks-wrapper.cc
@@ -47,11 +47,8 @@ static AsyncHooksWrap* UnwrapHook(
   AsyncHooks* hooks = PerIsolateData::Get(isolate)->GetAsyncHooks();
 
   if (!hooks->async_hook_ctor.Get(isolate)->HasInstance(hook)) {
-    isolate->ThrowException(
-        String::NewFromUtf8(
-            isolate, "Invalid 'this' passed instead of AsyncHooks instance",
-            NewStringType::kNormal)
-            .ToLocalChecked());
+    isolate->ThrowException(String::NewFromUtf8Literal(
+        isolate, "Invalid 'this' passed instead of AsyncHooks instance"));
     return nullptr;
   }
 
@@ -90,10 +87,8 @@ Local<Object> AsyncHooks::CreateHook(
   Local<Context> currentContext = isolate->GetCurrentContext();
 
   if (args.Length() != 1 || !args[0]->IsObject()) {
-    isolate->ThrowException(
-        String::NewFromUtf8(isolate, "Invalid arguments passed to createHook",
-                            NewStringType::kNormal)
-            .ToLocalChecked());
+    isolate->ThrowException(String::NewFromUtf8Literal(
+        isolate, "Invalid arguments passed to createHook"));
     return Local<Object>();
   }
 
@@ -101,15 +96,12 @@ Local<Object> AsyncHooks::CreateHook(
 
   Local<Object> fn_obj = args[0].As<Object>();
 
-#define SET_HOOK_FN(name)                                                   \
-  Local<Value> name##_v =                                                   \
-      fn_obj                                                                \
-          ->Get(currentContext,                                             \
-                String::NewFromUtf8(isolate, #name, NewStringType::kNormal) \
-                    .ToLocalChecked())                                      \
-          .ToLocalChecked();                                                \
-  if (name##_v->IsFunction()) {                                             \
-    wrap->set_##name##_function(name##_v.As<Function>());                   \
+#define SET_HOOK_FN(name)                                                     \
+  Local<Value> name##_v =                                                     \
+      fn_obj->Get(currentContext, String::NewFromUtf8Literal(isolate, #name)) \
+          .ToLocalChecked();                                                  \
+  if (name##_v->IsFunction()) {                                               \
+    wrap->set_##name##_function(name##_v.As<Function>());                     \
   }
 
   SET_HOOK_FN(init);
@@ -197,19 +189,16 @@ void AsyncHooks::Initialize() {
 
   async_hook_ctor.Reset(isolate_, FunctionTemplate::New(isolate_));
   async_hook_ctor.Get(isolate_)->SetClassName(
-      String::NewFromUtf8(isolate_, "AsyncHook", NewStringType::kNormal)
-          .ToLocalChecked());
+      String::NewFromUtf8Literal(isolate_, "AsyncHook"));
 
   async_hooks_templ.Reset(isolate_,
                           async_hook_ctor.Get(isolate_)->InstanceTemplate());
   async_hooks_templ.Get(isolate_)->SetInternalFieldCount(1);
   async_hooks_templ.Get(isolate_)->Set(
-      String::NewFromUtf8(isolate_, "enable", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
+      String::NewFromUtf8Literal(isolate_, "enable"),
       FunctionTemplate::New(isolate_, EnableHook));
   async_hooks_templ.Get(isolate_)->Set(
-      String::NewFromUtf8(isolate_, "disable", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
+      String::NewFromUtf8Literal(isolate_, "disable"),
       FunctionTemplate::New(isolate_, DisableHook));
 
   async_id_smb.Reset(isolate_, Private::New(isolate_));
@@ -262,10 +251,7 @@ void AsyncHooks::PromiseHookDispatch(PromiseHookType type,
   if (type == PromiseHookType::kInit) {
     if (!wrap->init_function().IsEmpty()) {
       Local<Value> initArgs[4] = {
-          async_id,
-          String::NewFromUtf8(hooks->isolate_, "PROMISE",
-                              NewStringType::kNormal)
-              .ToLocalChecked(),
+          async_id, String::NewFromUtf8Literal(hooks->isolate_, "PROMISE"),
           promise
               ->GetPrivate(context, hooks->trigger_id_smb.Get(hooks->isolate_))
               .ToLocalChecked(),
diff --git a/deps/v8/src/d8/d8-console.cc b/deps/v8/src/d8/d8-console.cc
index 9c133b60f4..5ecdf6767b 100644
--- a/deps/v8/src/d8/d8-console.cc
+++ b/deps/v8/src/d8/d8-console.cc
@@ -44,9 +44,7 @@ void D8Console::Assert(const debug::ConsoleCallArguments& args,
   if (args.Length() > 0 && args[0]->BooleanValue(isolate_)) return;
   WriteToFile("console.assert", stdout, isolate_, args);
   isolate_->ThrowException(v8::Exception::Error(
-      v8::String::NewFromUtf8(isolate_, "console.assert failed",
-                              v8::NewStringType::kNormal)
-          .ToLocalChecked()));
+      v8::String::NewFromUtf8Literal(isolate_, "console.assert failed")));
 }
 
 void D8Console::Log(const debug::ConsoleCallArguments& args,
diff --git a/deps/v8/src/d8/d8-posix.cc b/deps/v8/src/d8/d8-posix.cc
index 23767ba2b5..1c9f506641 100644
--- a/deps/v8/src/d8/d8-posix.cc
+++ b/deps/v8/src/d8/d8-posix.cc
@@ -158,11 +158,8 @@ class ExecArgs {
   bool Init(Isolate* isolate, Local<Value> arg0, Local<Array> command_args) {
     String::Utf8Value prog(isolate, arg0);
     if (*prog == nullptr) {
-      const char* message =
-          "os.system(): String conversion of program name failed";
-      isolate->ThrowException(
-          String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-              .ToLocalChecked());
+      isolate->ThrowException(String::NewFromUtf8Literal(
+          isolate, "os.system(): String conversion of program name failed"));
       return false;
     }
     int len = prog.length() + 3;
@@ -178,11 +175,8 @@ class ExecArgs {
       String::Utf8Value utf8_arg(isolate, arg);
       if (*utf8_arg == nullptr) {
         exec_args_[i] = nullptr;  // Consistent state for destructor.
-        const char* message =
-            "os.system(): String conversion of argument failed.";
-        isolate->ThrowException(
-            String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-                .ToLocalChecked());
+        isolate->ThrowException(String::NewFromUtf8Literal(
+            isolate, "os.system(): String conversion of argument failed."));
         return false;
       }
       int len = utf8_arg.length() + 1;
@@ -219,11 +213,8 @@ static bool GetTimeouts(const v8::FunctionCallbackInfo<v8::Value>& args,
                            ->Int32Value(args.GetIsolate()->GetCurrentContext())
                            .FromJust();
     } else {
-      args.GetIsolate()->ThrowException(
-          String::NewFromUtf8(args.GetIsolate(),
-                              "system: Argument 4 must be a number",
-                              NewStringType::kNormal)
-              .ToLocalChecked());
+      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+          args.GetIsolate(), "system: Argument 4 must be a number"));
       return false;
     }
   }
@@ -233,11 +224,8 @@ static bool GetTimeouts(const v8::FunctionCallbackInfo<v8::Value>& args,
                           ->Int32Value(args.GetIsolate()->GetCurrentContext())
                           .FromJust();
     } else {
-      args.GetIsolate()->ThrowException(
-          String::NewFromUtf8(args.GetIsolate(),
-                              "system: Argument 3 must be a number",
-                              NewStringType::kNormal)
-              .ToLocalChecked());
+      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+          args.GetIsolate(), "system: Argument 3 must be a number"));
       return false;
     }
   }
@@ -279,8 +267,7 @@ static bool ChildLaunchedOK(Isolate* isolate, int* exec_error_fds) {
   } while (bytes_read == -1 && errno == EINTR);
   if (bytes_read != 0) {
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(err), NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, strerror(err)).ToLocalChecked());
     return false;
   }
   return true;
@@ -299,8 +286,7 @@ static Local<Value> GetStdout(Isolate* isolate, int child_fd,
 
   if (fcntl(child_fd, F_SETFL, O_NONBLOCK) != 0) {
     return isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno), NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
   }
 
   int bytes_read;
@@ -311,10 +297,8 @@ static Local<Value> GetStdout(Isolate* isolate, int child_fd,
       if (errno == EAGAIN) {
         if (!WaitOnFD(child_fd, read_timeout, total_timeout, start_time) ||
             (TimeIsOut(start_time, total_timeout))) {
-          return isolate->ThrowException(
-              String::NewFromUtf8(isolate, "Timed out waiting for output",
-                                  NewStringType::kNormal)
-                  .ToLocalChecked());
+          return isolate->ThrowException(String::NewFromUtf8Literal(
+              isolate, "Timed out waiting for output"));
         }
         continue;
       } else if (errno == EINTR) {
@@ -372,11 +356,8 @@ static bool WaitForChild(Isolate* isolate, int pid,
     if (useconds < 1000000) useconds <<= 1;
     if ((read_timeout != -1 && useconds / 1000 > read_timeout) ||
         (TimeIsOut(start_time, total_timeout))) {
-      isolate->ThrowException(
-          String::NewFromUtf8(isolate,
-                              "Timed out waiting for process to terminate",
-                              NewStringType::kNormal)
-              .ToLocalChecked());
+      isolate->ThrowException(String::NewFromUtf8Literal(
+          isolate, "Timed out waiting for process to terminate"));
       kill(pid, SIGINT);
       return false;
     }
@@ -386,8 +367,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     snprintf(message, sizeof(message), "Child killed by signal %d",
              child_info.si_status);
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, message).ToLocalChecked());
     return false;
   }
   if (child_info.si_code == CLD_EXITED && child_info.si_status != 0) {
@@ -395,8 +375,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     snprintf(message, sizeof(message), "Child exited with status %d",
              child_info.si_status);
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, message).ToLocalChecked());
     return false;
   }
 
@@ -410,8 +389,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     snprintf(message, sizeof(message), "Child killed by signal %d",
              WTERMSIG(child_status));
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, message).ToLocalChecked());
     return false;
   }
   if (WEXITSTATUS(child_status) != 0) {
@@ -420,8 +398,7 @@ static bool WaitForChild(Isolate* isolate, int pid,
     snprintf(message, sizeof(message), "Child exited with status %d",
              exit_status);
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, message).ToLocalChecked());
     return false;
   }
 
@@ -441,11 +418,8 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Local<Array> command_args;
   if (args.Length() > 1) {
     if (!args[1]->IsArray()) {
-      args.GetIsolate()->ThrowException(
-          String::NewFromUtf8(args.GetIsolate(),
-                              "system: Argument 2 must be an array",
-                              NewStringType::kNormal)
-              .ToLocalChecked());
+      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+          args.GetIsolate(), "system: Argument 2 must be an array"));
       return;
     }
     command_args = Local<Array>::Cast(args[1]);
@@ -453,17 +427,13 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
     command_args = Array::New(args.GetIsolate(), 0);
   }
   if (command_args->Length() > ExecArgs::kMaxArgs) {
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), "Too many arguments to system()",
-                            NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "Too many arguments to system()"));
     return;
   }
   if (args.Length() < 1) {
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), "Too few arguments to system()",
-                            NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "Too few arguments to system()"));
     return;
   }
 
@@ -479,16 +449,12 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
   if (pipe(exec_error_fds) != 0) {
     args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), "pipe syscall failed.",
-                            NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8Literal(args.GetIsolate(), "pipe syscall failed."));
     return;
   }
   if (pipe(stdout_fds) != 0) {
     args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), "pipe syscall failed.",
-                            NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8Literal(args.GetIsolate(), "pipe syscall failed."));
     return;
   }
 
@@ -526,24 +492,20 @@ void Shell::System(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::ChangeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    const char* message = "chdir() takes one argument";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "chdir() takes one argument"));
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    const char* message = "os.chdir(): String conversion of argument failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.chdir(): String conversion of argument failed."));
     return;
   }
   if (chdir(*directory) != 0) {
     args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), strerror(errno),
-                            NewStringType::kNormal)
+        String::NewFromUtf8(args.GetIsolate(), strerror(errno))
             .ToLocalChecked());
     return;
   }
@@ -551,10 +513,8 @@ void Shell::ChangeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    const char* message = "umask() takes one argument";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "umask() takes one argument"));
     return;
   }
   if (args[0]->IsNumber()) {
@@ -563,10 +523,8 @@ void Shell::SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args) {
     args.GetReturnValue().Set(previous);
     return;
   } else {
-    const char* message = "umask() argument must be numeric";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "umask() argument must be numeric"));
     return;
   }
 }
@@ -576,14 +534,12 @@ static bool CheckItsADirectory(Isolate* isolate, char* directory) {
   int stat_result = stat(directory, &stat_buf);
   if (stat_result != 0) {
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno), NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
     return false;
   }
   if ((stat_buf.st_mode & S_IFDIR) != 0) return true;
   isolate->ThrowException(
-      String::NewFromUtf8(isolate, strerror(EEXIST), NewStringType::kNormal)
-          .ToLocalChecked());
+      String::NewFromUtf8(isolate, strerror(EEXIST)).ToLocalChecked());
   return false;
 }
 
@@ -598,8 +554,7 @@ static bool mkdirp(Isolate* isolate, char* directory, mode_t mask) {
     char* last_slash = strrchr(directory, '/');
     if (last_slash == nullptr) {
       isolate->ThrowException(
-          String::NewFromUtf8(isolate, strerror(errno), NewStringType::kNormal)
-              .ToLocalChecked());
+          String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
       return false;
     }
     *last_slash = 0;
@@ -611,13 +566,11 @@ static bool mkdirp(Isolate* isolate, char* directory, mode_t mask) {
       return CheckItsADirectory(isolate, directory);
     }
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno), NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
     return false;
   } else {
     isolate->ThrowException(
-        String::NewFromUtf8(isolate, strerror(errno), NewStringType::kNormal)
-            .ToLocalChecked());
+        String::NewFromUtf8(isolate, strerror(errno)).ToLocalChecked());
     return false;
   }
 }
@@ -630,26 +583,20 @@ void Shell::MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
                  ->Int32Value(args.GetIsolate()->GetCurrentContext())
                  .FromJust();
     } else {
-      const char* message = "mkdirp() second argument must be numeric";
-      args.GetIsolate()->ThrowException(
-          String::NewFromUtf8(args.GetIsolate(), message,
-                              NewStringType::kNormal)
-              .ToLocalChecked());
+      args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+          args.GetIsolate(), "mkdirp() second argument must be numeric"));
       return;
     }
   } else if (args.Length() != 1) {
-    const char* message = "mkdirp() takes one or two arguments";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "mkdirp() takes one or two arguments"));
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    const char* message = "os.mkdirp(): String conversion of argument failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.mkdirp(): String conversion of argument failed."));
     return;
   }
   mkdirp(args.GetIsolate(), *directory, mask);
@@ -657,18 +604,15 @@ void Shell::MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    const char* message = "rmdir() takes one or two arguments";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "rmdir() takes one or two arguments"));
     return;
   }
   String::Utf8Value directory(args.GetIsolate(), args[0]);
   if (*directory == nullptr) {
-    const char* message = "os.rmdir(): String conversion of argument failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.rmdir(): String conversion of argument failed."));
     return;
   }
   rmdir(*directory);
@@ -676,28 +620,22 @@ void Shell::RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::SetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 2) {
-    const char* message = "setenv() takes two arguments";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "setenv() takes two arguments"));
     return;
   }
   String::Utf8Value var(args.GetIsolate(), args[0]);
   String::Utf8Value value(args.GetIsolate(), args[1]);
   if (*var == nullptr) {
-    const char* message =
-        "os.setenv(): String conversion of variable name failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.setenv(): String conversion of variable name failed."));
     return;
   }
   if (*value == nullptr) {
-    const char* message =
-        "os.setenv(): String conversion of variable contents failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.setenv(): String conversion of variable contents failed."));
     return;
   }
   setenv(*var, *value, 1);
@@ -705,19 +643,15 @@ void Shell::SetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
 void Shell::UnsetEnvironment(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1) {
-    const char* message = "unsetenv() takes one argument";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(), "unsetenv() takes one argument"));
     return;
   }
   String::Utf8Value var(args.GetIsolate(), args[0]);
   if (*var == nullptr) {
-    const char* message =
-        "os.setenv(): String conversion of variable name failed.";
-    args.GetIsolate()->ThrowException(
-        String::NewFromUtf8(args.GetIsolate(), message, NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "os.setenv(): String conversion of variable name failed."));
     return;
   }
   unsetenv(*var);
@@ -827,27 +761,20 @@ char* Shell::ReadCharsFromTcpPort(const char* name, int* size_out) {
 
 void Shell::AddOSMethods(Isolate* isolate, Local<ObjectTemplate> os_templ) {
   if (options.enable_os_system) {
-    os_templ->Set(String::NewFromUtf8(isolate, "system", NewStringType::kNormal)
-                      .ToLocalChecked(),
+    os_templ->Set(String::NewFromUtf8Literal(isolate, "system"),
                   FunctionTemplate::New(isolate, System));
   }
-  os_templ->Set(String::NewFromUtf8(isolate, "chdir", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "chdir"),
                 FunctionTemplate::New(isolate, ChangeDirectory));
-  os_templ->Set(String::NewFromUtf8(isolate, "setenv", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "setenv"),
                 FunctionTemplate::New(isolate, SetEnvironment));
-  os_templ->Set(String::NewFromUtf8(isolate, "unsetenv", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "unsetenv"),
                 FunctionTemplate::New(isolate, UnsetEnvironment));
-  os_templ->Set(String::NewFromUtf8(isolate, "umask", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "umask"),
                 FunctionTemplate::New(isolate, SetUMask));
-  os_templ->Set(String::NewFromUtf8(isolate, "mkdirp", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "mkdirp"),
                 FunctionTemplate::New(isolate, MakeDirectory));
-  os_templ->Set(String::NewFromUtf8(isolate, "rmdir", NewStringType::kNormal)
-                    .ToLocalChecked(),
+  os_templ->Set(String::NewFromUtf8Literal(isolate, "rmdir"),
                 FunctionTemplate::New(isolate, RemoveDirectory));
 }
 
diff --git a/deps/v8/src/d8/d8.cc b/deps/v8/src/d8/d8.cc
index d6d21bf5fa..dd00c58288 100644
--- a/deps/v8/src/d8/d8.cc
+++ b/deps/v8/src/d8/d8.cc
@@ -10,6 +10,8 @@
 #include <algorithm>
 #include <fstream>
 #include <iomanip>
+#include <iterator>
+#include <string>
 #include <unordered_map>
 #include <utility>
 #include <vector>
@@ -35,6 +37,7 @@
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/diagnostics/basic-block-profiler.h"
 #include "src/execution/vm-state-inl.h"
+#include "src/handles/maybe-handles.h"
 #include "src/init/v8.h"
 #include "src/interpreter/interpreter.h"
 #include "src/logging/counters.h"
@@ -308,8 +311,7 @@ std::unique_ptr<v8::Platform> g_platform;
 
 static Local<Value> Throw(Isolate* isolate, const char* message) {
   return isolate->ThrowException(
-      String::NewFromUtf8(isolate, message, NewStringType::kNormal)
-          .ToLocalChecked());
+      String::NewFromUtf8(isolate, message).ToLocalChecked());
 }
 
 static MaybeLocal<Value> TryGetValue(v8::Isolate* isolate,
@@ -317,8 +319,7 @@ static MaybeLocal<Value> TryGetValue(v8::Isolate* isolate,
                                      Local<v8::Object> object,
                                      const char* property) {
   Local<String> v8_str =
-      String::NewFromUtf8(isolate, property, NewStringType::kNormal)
-          .FromMaybe(Local<String>());
+      String::NewFromUtf8(isolate, property).FromMaybe(Local<String>());
   if (v8_str.IsEmpty()) return Local<Value>();
   return object->Get(context, v8_str);
 }
@@ -370,8 +371,7 @@ class TraceConfigParser {
     HandleScope inner_scope(isolate);
 
     Local<String> source =
-        String::NewFromUtf8(isolate, json_str, NewStringType::kNormal)
-            .ToLocalChecked();
+        String::NewFromUtf8(isolate, json_str).ToLocalChecked();
     Local<Value> result = JSON::Parse(context, source).ToLocalChecked();
     Local<v8::Object> trace_config_object = Local<v8::Object>::Cast(result);
 
@@ -552,7 +552,8 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
 
     i::Handle<i::Script> script =
         parse_info.CreateScript(i_isolate, str, options.compile_options);
-    if (!i::parsing::ParseProgram(&parse_info, script, i_isolate)) {
+    if (!i::parsing::ParseProgram(&parse_info, script, i::kNullMaybeHandle,
+                                  i_isolate)) {
       fprintf(stderr, "Failed parsing\n");
       return false;
     }
@@ -640,7 +641,7 @@ bool Shell::ExecuteString(Isolate* isolate, Local<String> source,
     DCHECK(try_catch.HasCaught());
     return false;
   }
-  // It's possible that a FinalizationGroup cleanup task threw an error.
+  // It's possible that a FinalizationRegistry cleanup task threw an error.
   if (try_catch.HasCaught()) success = false;
   if (print_result) {
     if (options.test_shell) {
@@ -706,18 +707,29 @@ std::string DirName(const std::string& path) {
 // and replacing backslashes with slashes).
 std::string NormalizePath(const std::string& path,
                           const std::string& dir_name) {
-  std::string result;
+  std::string absolute_path;
   if (IsAbsolutePath(path)) {
-    result = path;
+    absolute_path = path;
   } else {
-    result = dir_name + '/' + path;
+    absolute_path = dir_name + '/' + path;
   }
-  std::replace(result.begin(), result.end(), '\\', '/');
-  size_t i;
-  while ((i = result.find("/./")) != std::string::npos) {
-    result.erase(i, 2);
+  std::replace(absolute_path.begin(), absolute_path.end(), '\\', '/');
+  std::vector<std::string> segments;
+  std::istringstream segment_stream(absolute_path);
+  std::string segment;
+  while (std::getline(segment_stream, segment, '/')) {
+    if (segment == "..") {
+      segments.pop_back();
+    } else if (segment != ".") {
+      segments.push_back(segment);
+    }
   }
-  return result;
+  // Join path segments.
+  std::ostringstream os;
+  std::copy(segments.begin(), segments.end() - 1,
+            std::ostream_iterator<std::string>(os, "/"));
+  os << *segments.rbegin();
+  return os.str();
 }
 
 // Per-context Module data, allowing sharing of module maps
@@ -785,14 +797,21 @@ MaybeLocal<Module> Shell::FetchModuleTree(Local<Context> context,
   DCHECK(IsAbsolutePath(file_name));
   Isolate* isolate = context->GetIsolate();
   Local<String> source_text = ReadFile(isolate, file_name.c_str());
+  if (source_text.IsEmpty() && options.fuzzy_module_file_extensions) {
+    std::string fallback_file_name = file_name + ".js";
+    source_text = ReadFile(isolate, fallback_file_name.c_str());
+    if (source_text.IsEmpty()) {
+      fallback_file_name = file_name + ".mjs";
+      source_text = ReadFile(isolate, fallback_file_name.c_str());
+    }
+  }
   if (source_text.IsEmpty()) {
     std::string msg = "Error reading: " + file_name;
     Throw(isolate, msg.c_str());
     return MaybeLocal<Module>();
   }
   ScriptOrigin origin(
-      String::NewFromUtf8(isolate, file_name.c_str(), NewStringType::kNormal)
-          .ToLocalChecked(),
+      String::NewFromUtf8(isolate, file_name.c_str()).ToLocalChecked(),
       Local<Integer>(), Local<Integer>(), Local<Boolean>(), Local<Integer>(),
       Local<Value>(), Local<Boolean>(), Local<Boolean>(), True(isolate));
   ScriptCompiler::Source source(source_text, origin);
@@ -815,10 +834,9 @@ MaybeLocal<Module> Shell::FetchModuleTree(Local<Context> context,
     Local<String> name = module->GetModuleRequest(i);
     std::string absolute_path =
         NormalizePath(ToSTLString(isolate, name), dir_name);
-    if (!d->specifier_to_module_map.count(absolute_path)) {
-      if (FetchModuleTree(context, absolute_path).IsEmpty()) {
-        return MaybeLocal<Module>();
-      }
+    if (d->specifier_to_module_map.count(absolute_path)) continue;
+    if (FetchModuleTree(context, absolute_path).IsEmpty()) {
+      return MaybeLocal<Module>();
     }
   }
 
@@ -916,16 +934,6 @@ MaybeLocal<Promise> Shell::HostImportModuleDynamically(
   return MaybeLocal<Promise>();
 }
 
-void Shell::HostCleanupFinalizationGroup(Local<Context> context,
-                                         Local<FinalizationGroup> fg) {
-  Isolate* isolate = context->GetIsolate();
-  PerIsolateData::Get(isolate)->HostCleanupFinalizationGroup(fg);
-}
-
-void PerIsolateData::HostCleanupFinalizationGroup(Local<FinalizationGroup> fg) {
-  cleanup_finalization_groups_.emplace(isolate_, fg);
-}
-
 void Shell::HostInitializeImportMetaObject(Local<Context> context,
                                            Local<Module> module,
                                            Local<Object> meta) {
@@ -938,10 +946,8 @@ void Shell::HostInitializeImportMetaObject(Local<Context> context,
   CHECK(specifier_it != d->module_to_specifier_map.end());
 
   Local<String> url_key =
-      String::NewFromUtf8(isolate, "url", NewStringType::kNormal)
-          .ToLocalChecked();
-  Local<String> url = String::NewFromUtf8(isolate, specifier_it->second.c_str(),
-                                          NewStringType::kNormal)
+      String::NewFromUtf8Literal(isolate, "url", NewStringType::kInternalized);
+  Local<String> url = String::NewFromUtf8(isolate, specifier_it->second.c_str())
                           .ToLocalChecked();
   meta->CreateDataProperty(context, url_key, url).ToChecked();
 }
@@ -1017,7 +1023,7 @@ void Shell::DoHostImportModuleDynamically(void* import_data) {
     result_promise->Then(realm, callback_success, callback_failure)
         .ToLocalChecked();
   } else {
-    // TODO(joshualitt): Clean up exception handling after introucing new
+    // TODO(cbruni): Clean up exception handling after introducing new
     // API for evaluating async modules.
     DCHECK(!try_catch.HasCaught());
     resolver->Resolve(realm, module_namespace).ToChecked();
@@ -1062,17 +1068,17 @@ bool Shell::ExecuteModule(Isolate* isolate, const char* file_name) {
   }
   if (i::FLAG_harmony_top_level_await) {
     // Loop until module execution finishes
-    // TODO(joshualitt): This is a bit wonky. "Real" engines would not be
+    // TODO(cbruni): This is a bit wonky. "Real" engines would not be
     // able to just busy loop waiting for execution to finish.
     Local<Promise> result_promise(Local<Promise>::Cast(result));
     while (result_promise->State() == Promise::kPending) {
-      isolate->RunMicrotasks();
+      isolate->PerformMicrotaskCheckpoint();
     }
 
     if (result_promise->State() == Promise::kRejected) {
       // If the exception has been caught by the promise pipeline, we rethrow
       // here in order to ReportException.
-      // TODO(joshualitt): Clean this up after we create a new API for the case
+      // TODO(cbruni): Clean this up after we create a new API for the case
       // where TLA is enabled.
       if (!try_catch.HasCaught()) {
         isolate->ThrowException(result_promise->Result());
@@ -1123,15 +1129,6 @@ MaybeLocal<Context> PerIsolateData::GetTimeoutContext() {
   return result;
 }
 
-MaybeLocal<FinalizationGroup> PerIsolateData::GetCleanupFinalizationGroup() {
-  if (cleanup_finalization_groups_.empty())
-    return MaybeLocal<FinalizationGroup>();
-  Local<FinalizationGroup> result =
-      cleanup_finalization_groups_.front().Get(isolate_);
-  cleanup_finalization_groups_.pop();
-  return result;
-}
-
 PerIsolateData::RealmScope::RealmScope(PerIsolateData* data) : data_(data) {
   data_->realm_count_ = 1;
   data_->realm_current_ = 0;
@@ -1281,8 +1278,11 @@ void Shell::DisposeRealm(const v8::FunctionCallbackInfo<v8::Value>& args,
                          int index) {
   Isolate* isolate = args.GetIsolate();
   PerIsolateData* data = PerIsolateData::Get(isolate);
-  DisposeModuleEmbedderData(data->realms_[index].Get(isolate));
+  Local<Context> context = data->realms_[index].Get(isolate);
+  DisposeModuleEmbedderData(context);
   data->realms_[index].Reset();
+  // ContextDisposedNotification expects the disposed context to be entered.
+  v8::Context::Scope scope(context);
   isolate->ContextDisposedNotification();
   isolate->IdleNotificationDeadline(g_platform->MonotonicallyIncreasingTime());
 }
@@ -1524,8 +1524,7 @@ void Shell::Read(const v8::FunctionCallbackInfo<v8::Value>& args) {
 Local<String> Shell::ReadFromStdin(Isolate* isolate) {
   static const int kBufferSize = 256;
   char buffer[kBufferSize];
-  Local<String> accumulator =
-      String::NewFromUtf8(isolate, "", NewStringType::kNormal).ToLocalChecked();
+  Local<String> accumulator = String::NewFromUtf8Literal(isolate, "");
   int length;
   while (true) {
     // Continue reading if the line ends with an escape '\\' or the line has
@@ -1574,9 +1573,7 @@ void Shell::Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
     }
     if (!ExecuteString(
             args.GetIsolate(), source,
-            String::NewFromUtf8(args.GetIsolate(), *file,
-                                NewStringType::kNormal)
-                .ToLocalChecked(),
+            String::NewFromUtf8(args.GetIsolate(), *file).ToLocalChecked(),
             kNoPrintResult,
             options.quiet_load ? kNoReportExceptions : kReportExceptions,
             kNoProcessMessageQueue)) {
@@ -1750,10 +1747,9 @@ void Shell::NotifyDone(const v8::FunctionCallbackInfo<v8::Value>& args) {
 }
 
 void Shell::Version(const v8::FunctionCallbackInfo<v8::Value>& args) {
-  args.GetReturnValue().Set(String::NewFromUtf8(args.GetIsolate(),
-                                                V8::GetVersion(),
-                                                NewStringType::kNormal)
-                                .ToLocalChecked());
+  args.GetReturnValue().Set(
+      String::NewFromUtf8(args.GetIsolate(), V8::GetVersion())
+          .ToLocalChecked());
 }
 
 void Shell::ReportException(Isolate* isolate, Local<v8::Message> message,
@@ -1907,11 +1903,8 @@ Local<String> Shell::Stringify(Isolate* isolate, Local<Value> value) {
       v8::Local<v8::Context>::New(isolate, evaluation_context_);
   if (stringify_function_.IsEmpty()) {
     Local<String> source =
-        String::NewFromUtf8(isolate, stringify_source_, NewStringType::kNormal)
-            .ToLocalChecked();
-    Local<String> name =
-        String::NewFromUtf8(isolate, "d8-stringify", NewStringType::kNormal)
-            .ToLocalChecked();
+        String::NewFromUtf8(isolate, stringify_source_).ToLocalChecked();
+    Local<String> name = String::NewFromUtf8Literal(isolate, "d8-stringify");
     ScriptOrigin origin(name);
     Local<Script> script =
         Script::Compile(context, source, &origin).ToLocalChecked();
@@ -1928,197 +1921,113 @@ Local<String> Shell::Stringify(Isolate* isolate, Local<Value> value) {
 
 Local<ObjectTemplate> Shell::CreateGlobalTemplate(Isolate* isolate) {
   Local<ObjectTemplate> global_template = ObjectTemplate::New(isolate);
-  global_template->Set(
-      String::NewFromUtf8(isolate, "print", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Print));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "printErr", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, PrintErr));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "write", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Write));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "read", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Read));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "readbuffer", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, ReadBuffer));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "readline", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, ReadLine));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "load", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Load));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "setTimeout", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, SetTimeout));
+  global_template->Set(isolate, "print", FunctionTemplate::New(isolate, Print));
+  global_template->Set(isolate, "printErr",
+                       FunctionTemplate::New(isolate, PrintErr));
+  global_template->Set(isolate, "write", FunctionTemplate::New(isolate, Write));
+  global_template->Set(isolate, "read", FunctionTemplate::New(isolate, Read));
+  global_template->Set(isolate, "readbuffer",
+                       FunctionTemplate::New(isolate, ReadBuffer));
+  global_template->Set(isolate, "readline",
+                       FunctionTemplate::New(isolate, ReadLine));
+  global_template->Set(isolate, "load", FunctionTemplate::New(isolate, Load));
+  global_template->Set(isolate, "setTimeout",
+                       FunctionTemplate::New(isolate, SetTimeout));
   // Some Emscripten-generated code tries to call 'quit', which in turn would
   // call C's exit(). This would lead to memory leaks, because there is no way
   // we can terminate cleanly then, so we need a way to hide 'quit'.
   if (!options.omit_quit) {
-    global_template->Set(
-        String::NewFromUtf8(isolate, "quit", NewStringType::kNormal)
-            .ToLocalChecked(),
-        FunctionTemplate::New(isolate, Quit));
+    global_template->Set(isolate, "quit", FunctionTemplate::New(isolate, Quit));
   }
   Local<ObjectTemplate> test_template = ObjectTemplate::New(isolate);
-  global_template->Set(
-      String::NewFromUtf8(isolate, "testRunner", NewStringType::kNormal)
-          .ToLocalChecked(),
-      test_template);
-  test_template->Set(
-      String::NewFromUtf8(isolate, "notifyDone", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, NotifyDone));
-  test_template->Set(
-      String::NewFromUtf8(isolate, "waitUntilDone", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, WaitUntilDone));
+  global_template->Set(isolate, "testRunner", test_template);
+  test_template->Set(isolate, "notifyDone",
+                     FunctionTemplate::New(isolate, NotifyDone));
+  test_template->Set(isolate, "waitUntilDone",
+                     FunctionTemplate::New(isolate, WaitUntilDone));
   // Reliable access to quit functionality. The "quit" method function
   // installed on the global object can be hidden with the --omit-quit flag
   // (e.g. on asan bots).
-  test_template->Set(
-      String::NewFromUtf8(isolate, "quit", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Quit));
-
-  global_template->Set(
-      String::NewFromUtf8(isolate, "version", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, Version));
-  global_template->Set(
-      Symbol::GetToStringTag(isolate),
-      String::NewFromUtf8(isolate, "global", NewStringType::kNormal)
-          .ToLocalChecked());
+  test_template->Set(isolate, "quit", FunctionTemplate::New(isolate, Quit));
+
+  global_template->Set(isolate, "version",
+                       FunctionTemplate::New(isolate, Version));
+  global_template->Set(Symbol::GetToStringTag(isolate),
+                       String::NewFromUtf8Literal(isolate, "global"));
 
   // Bind the Realm object.
   Local<ObjectTemplate> realm_template = ObjectTemplate::New(isolate);
+  realm_template->Set(isolate, "current",
+                      FunctionTemplate::New(isolate, RealmCurrent));
+  realm_template->Set(isolate, "owner",
+                      FunctionTemplate::New(isolate, RealmOwner));
+  realm_template->Set(isolate, "global",
+                      FunctionTemplate::New(isolate, RealmGlobal));
+  realm_template->Set(isolate, "create",
+                      FunctionTemplate::New(isolate, RealmCreate));
   realm_template->Set(
-      String::NewFromUtf8(isolate, "current", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmCurrent));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "owner", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmOwner));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "global", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmGlobal));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "create", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmCreate));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "createAllowCrossRealmAccess",
-                          NewStringType::kNormal)
-          .ToLocalChecked(),
+      isolate, "createAllowCrossRealmAccess",
       FunctionTemplate::New(isolate, RealmCreateAllowCrossRealmAccess));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "navigate", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmNavigate));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "detachGlobal", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmDetachGlobal));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "dispose", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmDispose));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "switch", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmSwitch));
-  realm_template->Set(
-      String::NewFromUtf8(isolate, "eval", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, RealmEval));
-  realm_template->SetAccessor(
-      String::NewFromUtf8(isolate, "shared", NewStringType::kNormal)
-          .ToLocalChecked(),
-      RealmSharedGet, RealmSharedSet);
-  global_template->Set(
-      String::NewFromUtf8(isolate, "Realm", NewStringType::kNormal)
-          .ToLocalChecked(),
-      realm_template);
+  realm_template->Set(isolate, "navigate",
+                      FunctionTemplate::New(isolate, RealmNavigate));
+  realm_template->Set(isolate, "detachGlobal",
+                      FunctionTemplate::New(isolate, RealmDetachGlobal));
+  realm_template->Set(isolate, "dispose",
+                      FunctionTemplate::New(isolate, RealmDispose));
+  realm_template->Set(isolate, "switch",
+                      FunctionTemplate::New(isolate, RealmSwitch));
+  realm_template->Set(isolate, "eval",
+                      FunctionTemplate::New(isolate, RealmEval));
+  realm_template->SetAccessor(String::NewFromUtf8Literal(isolate, "shared"),
+                              RealmSharedGet, RealmSharedSet);
+  global_template->Set(isolate, "Realm", realm_template);
 
   Local<ObjectTemplate> performance_template = ObjectTemplate::New(isolate);
+  performance_template->Set(isolate, "now",
+                            FunctionTemplate::New(isolate, PerformanceNow));
   performance_template->Set(
-      String::NewFromUtf8(isolate, "now", NewStringType::kNormal)
-          .ToLocalChecked(),
-      FunctionTemplate::New(isolate, PerformanceNow));
-  performance_template->Set(
-      String::NewFromUtf8(isolate, "measureMemory", NewStringType::kNormal)
-          .ToLocalChecked(),
+      isolate, "measureMemory",
       FunctionTemplate::New(isolate, PerformanceMeasureMemory));
-  global_template->Set(
-      String::NewFromUtf8(isolate, "performance", NewStringType::kNormal)
-          .ToLocalChecked(),
-      performance_template);
+  global_template->Set(isolate, "performance", performance_template);
 
   Local<FunctionTemplate> worker_fun_template =
       FunctionTemplate::New(isolate, WorkerNew);
   Local<Signature> worker_signature =
       Signature::New(isolate, worker_fun_template);
   worker_fun_template->SetClassName(
-      String::NewFromUtf8(isolate, "Worker", NewStringType::kNormal)
-          .ToLocalChecked());
+      String::NewFromUtf8Literal(isolate, "Worker"));
   worker_fun_template->ReadOnlyPrototype();
   worker_fun_template->PrototypeTemplate()->Set(
-      String::NewFromUtf8(isolate, "terminate", NewStringType::kNormal)
-          .ToLocalChecked(),
+      isolate, "terminate",
       FunctionTemplate::New(isolate, WorkerTerminate, Local<Value>(),
                             worker_signature));
   worker_fun_template->PrototypeTemplate()->Set(
-      String::NewFromUtf8(isolate, "postMessage", NewStringType::kNormal)
-          .ToLocalChecked(),
+      isolate, "postMessage",
       FunctionTemplate::New(isolate, WorkerPostMessage, Local<Value>(),
                             worker_signature));
   worker_fun_template->PrototypeTemplate()->Set(
-      String::NewFromUtf8(isolate, "getMessage", NewStringType::kNormal)
-          .ToLocalChecked(),
+      isolate, "getMessage",
       FunctionTemplate::New(isolate, WorkerGetMessage, Local<Value>(),
                             worker_signature));
   worker_fun_template->InstanceTemplate()->SetInternalFieldCount(1);
-  global_template->Set(
-      String::NewFromUtf8(isolate, "Worker", NewStringType::kNormal)
-          .ToLocalChecked(),
-      worker_fun_template);
+  global_template->Set(isolate, "Worker", worker_fun_template);
 
   Local<ObjectTemplate> os_templ = ObjectTemplate::New(isolate);
   AddOSMethods(isolate, os_templ);
-  global_template->Set(
-      String::NewFromUtf8(isolate, "os", NewStringType::kNormal)
-          .ToLocalChecked(),
-      os_templ);
+  global_template->Set(isolate, "os", os_templ);
 
   if (i::FLAG_expose_async_hooks) {
     Local<ObjectTemplate> async_hooks_templ = ObjectTemplate::New(isolate);
     async_hooks_templ->Set(
-        String::NewFromUtf8(isolate, "createHook", NewStringType::kNormal)
-            .ToLocalChecked(),
+        isolate, "createHook",
         FunctionTemplate::New(isolate, AsyncHooksCreateHook));
     async_hooks_templ->Set(
-        String::NewFromUtf8(isolate, "executionAsyncId", NewStringType::kNormal)
-            .ToLocalChecked(),
+        isolate, "executionAsyncId",
         FunctionTemplate::New(isolate, AsyncHooksExecutionAsyncId));
     async_hooks_templ->Set(
-        String::NewFromUtf8(isolate, "triggerAsyncId", NewStringType::kNormal)
-            .ToLocalChecked(),
+        isolate, "triggerAsyncId",
         FunctionTemplate::New(isolate, AsyncHooksTriggerAsyncId));
-    global_template->Set(
-        String::NewFromUtf8(isolate, "async_hooks", NewStringType::kNormal)
-            .ToLocalChecked(),
-        async_hooks_templ);
+    global_template->Set(isolate, "async_hooks", async_hooks_templ);
   }
 
   return global_template;
@@ -2158,17 +2067,27 @@ static void PrintMessageCallback(Local<Message> message, Local<Value> error) {
   printf("%s:%i: %s\n", filename_string, linenum, msg_string);
 }
 
-void Shell::Initialize(Isolate* isolate) {
-  // Set up counters
-  if (i::FLAG_map_counters[0] != '\0') {
-    MapCounters(isolate, i::FLAG_map_counters);
+void Shell::Initialize(Isolate* isolate, D8Console* console,
+                       bool isOnMainThread) {
+  if (isOnMainThread) {
+    // Set up counters
+    if (i::FLAG_map_counters[0] != '\0') {
+      MapCounters(isolate, i::FLAG_map_counters);
+    }
+    // Disable default message reporting.
+    isolate->AddMessageListenerWithErrorLevel(
+        PrintMessageCallback,
+        v8::Isolate::kMessageError | v8::Isolate::kMessageWarning |
+            v8::Isolate::kMessageInfo | v8::Isolate::kMessageDebug |
+            v8::Isolate::kMessageLog);
   }
-  // Disable default message reporting.
-  isolate->AddMessageListenerWithErrorLevel(
-      PrintMessageCallback,
-      v8::Isolate::kMessageError | v8::Isolate::kMessageWarning |
-          v8::Isolate::kMessageInfo | v8::Isolate::kMessageDebug |
-          v8::Isolate::kMessageLog);
+
+  isolate->SetHostImportModuleDynamicallyCallback(
+      Shell::HostImportModuleDynamically);
+  isolate->SetHostInitializeImportMetaObjectCallback(
+      Shell::HostInitializeImportMetaObject);
+
+  debug::SetConsoleDelegate(isolate, console);
 }
 
 Local<Context> Shell::CreateEvaluationContext(Isolate* isolate) {
@@ -2190,14 +2109,12 @@ Local<Context> Shell::CreateEvaluationContext(Isolate* isolate) {
     Local<Array> array = Array::New(isolate, size);
     for (int i = 0; i < size; i++) {
       Local<String> arg =
-          v8::String::NewFromUtf8(isolate, args[i], v8::NewStringType::kNormal)
-              .ToLocalChecked();
+          v8::String::NewFromUtf8(isolate, args[i]).ToLocalChecked();
       Local<Number> index = v8::Number::New(isolate, i);
       array->Set(context, index, arg).FromJust();
     }
-    Local<String> name =
-        String::NewFromUtf8(isolate, "arguments", NewStringType::kInternalized)
-            .ToLocalChecked();
+    Local<String> name = String::NewFromUtf8Literal(
+        isolate, "arguments", NewStringType::kInternalized);
     context->Global()->Set(context, name, array).FromJust();
   }
   return handle_scope.Escape(context);
@@ -2471,9 +2388,7 @@ void Shell::RunShell(Isolate* isolate) {
       v8::Local<v8::Context>::New(isolate, evaluation_context_);
   v8::Context::Scope context_scope(context);
   PerIsolateData::RealmScope realm_scope(PerIsolateData::Get(isolate));
-  Local<String> name =
-      String::NewFromUtf8(isolate, "(d8)", NewStringType::kNormal)
-          .ToLocalChecked();
+  Local<String> name = String::NewFromUtf8Literal(isolate, "(d8)");
   printf("V8 version %s\n", V8::GetVersion());
   while (true) {
     HandleScope inner_scope(isolate);
@@ -2525,9 +2440,8 @@ class InspectorFrontend final : public v8_inspector::V8Inspector::Channel {
                    reinterpret_cast<const uint16_t*>(string.characters16()),
                    v8::NewStringType::kNormal, length))
             .ToLocalChecked();
-    Local<String> callback_name =
-        v8::String::NewFromUtf8(isolate_, "receive", v8::NewStringType::kNormal)
-            .ToLocalChecked();
+    Local<String> callback_name = v8::String::NewFromUtf8Literal(
+        isolate_, "receive", NewStringType::kInternalized);
     Local<Context> context = context_.Get(isolate_);
     Local<Value> callback =
         context->Global()->Get(context, callback_name).ToLocalChecked();
@@ -2539,14 +2453,10 @@ class InspectorFrontend final : public v8_inspector::V8Inspector::Channel {
 #ifdef DEBUG
       if (try_catch.HasCaught()) {
         Local<Object> exception = Local<Object>::Cast(try_catch.Exception());
-        Local<String> key = v8::String::NewFromUtf8(isolate_, "message",
-                                                    v8::NewStringType::kNormal)
-                                .ToLocalChecked();
-        Local<String> expected =
-            v8::String::NewFromUtf8(isolate_,
-                                    "Maximum call stack size exceeded",
-                                    v8::NewStringType::kNormal)
-                .ToLocalChecked();
+        Local<String> key = v8::String::NewFromUtf8Literal(
+            isolate_, "message", NewStringType::kInternalized);
+        Local<String> expected = v8::String::NewFromUtf8Literal(
+            isolate_, "Maximum call stack size exceeded");
         Local<Value> value = exception->Get(context, key).ToLocalChecked();
         DCHECK(value->StrictEquals(expected));
       }
@@ -2575,9 +2485,8 @@ class InspectorClient : public v8_inspector::V8InspectorClient {
         FunctionTemplate::New(isolate_, SendInspectorMessage)
             ->GetFunction(context)
             .ToLocalChecked();
-    Local<String> function_name =
-        String::NewFromUtf8(isolate_, "send", NewStringType::kNormal)
-            .ToLocalChecked();
+    Local<String> function_name = String::NewFromUtf8Literal(
+        isolate_, "send", NewStringType::kInternalized);
     CHECK(context->Global()->Set(context, function_name, function).FromJust());
 
     context_.Reset(isolate_, context);
@@ -2586,10 +2495,8 @@ class InspectorClient : public v8_inspector::V8InspectorClient {
   void runMessageLoopOnPause(int contextGroupId) override {
     v8::Isolate::AllowJavascriptExecutionScope allow_script(isolate_);
     v8::HandleScope handle_scope(isolate_);
-    Local<String> callback_name =
-        v8::String::NewFromUtf8(isolate_, "handleInspectorMessage",
-                                v8::NewStringType::kNormal)
-            .ToLocalChecked();
+    Local<String> callback_name = v8::String::NewFromUtf8Literal(
+        isolate_, "handleInspectorMessage", NewStringType::kInternalized);
     Local<Context> context = context_.Get(isolate_);
     Local<Value> callback =
         context->Global()->Get(context, callback_name).ToLocalChecked();
@@ -2674,12 +2581,9 @@ bool SourceGroup::Execute(Isolate* isolate) {
     if (strcmp(arg, "-e") == 0 && i + 1 < end_offset_) {
       // Execute argument given to -e option directly.
       HandleScope handle_scope(isolate);
-      Local<String> file_name =
-          String::NewFromUtf8(isolate, "unnamed", NewStringType::kNormal)
-              .ToLocalChecked();
+      Local<String> file_name = String::NewFromUtf8Literal(isolate, "unnamed");
       Local<String> source =
-          String::NewFromUtf8(isolate, argv_[i + 1], NewStringType::kNormal)
-              .ToLocalChecked();
+          String::NewFromUtf8(isolate, argv_[i + 1]).ToLocalChecked();
       Shell::set_script_executed();
       if (!Shell::ExecuteString(isolate, source, file_name,
                                 Shell::kNoPrintResult, Shell::kReportExceptions,
@@ -2713,8 +2617,7 @@ bool SourceGroup::Execute(Isolate* isolate) {
     // Use all other arguments as names of files to load and run.
     HandleScope handle_scope(isolate);
     Local<String> file_name =
-        String::NewFromUtf8(isolate, arg, NewStringType::kNormal)
-            .ToLocalChecked();
+        String::NewFromUtf8(isolate, arg).ToLocalChecked();
     Local<String> source = ReadFile(isolate, arg);
     if (source.IsEmpty()) {
       printf("Error reading '%s'\n", arg);
@@ -2742,15 +2645,10 @@ void SourceGroup::ExecuteInThread() {
   Isolate::CreateParams create_params;
   create_params.array_buffer_allocator = Shell::array_buffer_allocator;
   Isolate* isolate = Isolate::New(create_params);
-  isolate->SetHostCleanupFinalizationGroupCallback(
-      Shell::HostCleanupFinalizationGroup);
-  isolate->SetHostImportModuleDynamicallyCallback(
-      Shell::HostImportModuleDynamically);
-  isolate->SetHostInitializeImportMetaObjectCallback(
-      Shell::HostInitializeImportMetaObject);
   Shell::SetWaitUntilDone(isolate, false);
   D8Console console(isolate);
-  debug::SetConsoleDelegate(isolate, &console);
+  Shell::Initialize(isolate, &console, false);
+
   for (int i = 0; i < Shell::options.stress_runs; ++i) {
     next_semaphore_.Wait();
     {
@@ -2889,14 +2787,8 @@ void Worker::ExecuteInThread() {
   Isolate::CreateParams create_params;
   create_params.array_buffer_allocator = Shell::array_buffer_allocator;
   Isolate* isolate = Isolate::New(create_params);
-  isolate->SetHostCleanupFinalizationGroupCallback(
-      Shell::HostCleanupFinalizationGroup);
-  isolate->SetHostImportModuleDynamicallyCallback(
-      Shell::HostImportModuleDynamically);
-  isolate->SetHostInitializeImportMetaObjectCallback(
-      Shell::HostInitializeImportMetaObject);
   D8Console console(isolate);
-  debug::SetConsoleDelegate(isolate, &console);
+  Shell::Initialize(isolate, &console, false);
   {
     Isolate::Scope iscope(isolate);
     {
@@ -2917,29 +2809,26 @@ void Worker::ExecuteInThread() {
                 &postmessage_fun)) {
           global
               ->Set(context,
-                    String::NewFromUtf8(isolate, "postMessage",
-                                        NewStringType::kNormal)
-                        .ToLocalChecked(),
+                    v8::String::NewFromUtf8Literal(
+                        isolate, "postMessage", NewStringType::kInternalized),
                     postmessage_fun)
               .FromJust();
         }
 
         // First run the script
         Local<String> file_name =
-            String::NewFromUtf8(isolate, "unnamed", NewStringType::kNormal)
-                .ToLocalChecked();
+            String::NewFromUtf8Literal(isolate, "unnamed");
         Local<String> source =
-            String::NewFromUtf8(isolate, script_, NewStringType::kNormal)
-                .ToLocalChecked();
+            String::NewFromUtf8(isolate, script_).ToLocalChecked();
         if (Shell::ExecuteString(
                 isolate, source, file_name, Shell::kNoPrintResult,
                 Shell::kReportExceptions, Shell::kProcessMessageQueue)) {
           // Get the message handler
           Local<Value> onmessage =
               global
-                  ->Get(context, String::NewFromUtf8(isolate, "onmessage",
-                                                     NewStringType::kNormal)
-                                     .ToLocalChecked())
+                  ->Get(context,
+                        String::NewFromUtf8Literal(
+                            isolate, "onmessage", NewStringType::kInternalized))
                   .ToLocalChecked();
           if (onmessage->IsFunction()) {
             Local<Function> onmessage_fun = Local<Function>::Cast(onmessage);
@@ -3147,6 +3036,9 @@ bool Shell::SetOptions(int argc, char* argv[]) {
       options.cpu_profiler = true;
       options.cpu_profiler_print = true;
       argv[i] = nullptr;
+    } else if (strcmp(argv[i], "--fuzzy-module-file-extensions") == 0) {
+      options.fuzzy_module_file_extensions = true;
+      argv[i] = nullptr;
     }
   }
 
@@ -3272,21 +3164,6 @@ bool RunSetTimeoutCallback(Isolate* isolate, bool* did_run) {
   return true;
 }
 
-bool RunCleanupFinalizationGroupCallback(Isolate* isolate, bool* did_run) {
-  PerIsolateData* data = PerIsolateData::Get(isolate);
-  HandleScope handle_scope(isolate);
-  while (true) {
-    Local<FinalizationGroup> fg;
-    if (!data->GetCleanupFinalizationGroup().ToLocal(&fg)) return true;
-    *did_run = true;
-    TryCatch try_catch(isolate);
-    try_catch.SetVerbose(true);
-    if (FinalizationGroup::Cleanup(fg).IsNothing()) {
-      return false;
-    }
-  }
-}
-
 bool ProcessMessages(
     Isolate* isolate,
     const std::function<platform::MessageLoopBehavior()>& behavior) {
@@ -3297,23 +3174,17 @@ bool ProcessMessages(
     while (v8::platform::PumpMessageLoop(g_default_platform, isolate,
                                          behavior())) {
       MicrotasksScope::PerformCheckpoint(isolate);
-      isolate->ClearKeptObjects();
     }
     if (g_default_platform->IdleTasksEnabled(isolate)) {
       v8::platform::RunIdleTasks(g_default_platform, isolate,
                                  50.0 / base::Time::kMillisecondsPerSecond);
     }
-    bool ran_finalization_callback = false;
-    if (!RunCleanupFinalizationGroupCallback(isolate,
-                                             &ran_finalization_callback)) {
-      return false;
-    }
     bool ran_set_timeout = false;
     if (!RunSetTimeoutCallback(isolate, &ran_set_timeout)) {
       return false;
     }
 
-    if (!ran_set_timeout && !ran_finalization_callback) return true;
+    if (!ran_set_timeout) return true;
   }
   return true;
 }
@@ -3768,19 +3639,12 @@ int Shell::Main(int argc, char* argv[]) {
   }
 
   Isolate* isolate = Isolate::New(create_params);
-  isolate->SetHostCleanupFinalizationGroupCallback(
-      Shell::HostCleanupFinalizationGroup);
-  isolate->SetHostImportModuleDynamicallyCallback(
-      Shell::HostImportModuleDynamically);
-  isolate->SetHostInitializeImportMetaObjectCallback(
-      Shell::HostInitializeImportMetaObject);
 
-  D8Console console(isolate);
   {
+    D8Console console(isolate);
     Isolate::Scope scope(isolate);
-    Initialize(isolate);
+    Initialize(isolate, &console);
     PerIsolateData data(isolate);
-    debug::SetConsoleDelegate(isolate, &console);
 
     if (options.trace_enabled) {
       platform::tracing::TraceConfig* trace_config;
@@ -3832,16 +3696,9 @@ int Shell::Main(int argc, char* argv[]) {
       i::FLAG_hash_seed ^= 1337;  // Use a different hash seed.
       Isolate* isolate2 = Isolate::New(create_params);
       i::FLAG_hash_seed ^= 1337;  // Restore old hash seed.
-      isolate2->SetHostCleanupFinalizationGroupCallback(
-          Shell::HostCleanupFinalizationGroup);
-      isolate2->SetHostImportModuleDynamicallyCallback(
-          Shell::HostImportModuleDynamically);
-      isolate2->SetHostInitializeImportMetaObjectCallback(
-          Shell::HostInitializeImportMetaObject);
       {
         D8Console console(isolate2);
-        Initialize(isolate2);
-        debug::SetConsoleDelegate(isolate2, &console);
+        Initialize(isolate2, &console);
         PerIsolateData data(isolate2);
         Isolate::Scope isolate_scope(isolate2);
 
diff --git a/deps/v8/src/d8/d8.h b/deps/v8/src/d8/d8.h
index 435eb6dbd8..2d27f62e58 100644
--- a/deps/v8/src/d8/d8.h
+++ b/deps/v8/src/d8/d8.h
@@ -23,6 +23,8 @@
 
 namespace v8 {
 
+class D8Console;
+
 // A single counter in a counter collection.
 class Counter {
  public:
@@ -226,8 +228,6 @@ class PerIsolateData {
     PerIsolateData* data_;
   };
 
-  inline void HostCleanupFinalizationGroup(Local<FinalizationGroup> fg);
-  inline MaybeLocal<FinalizationGroup> GetCleanupFinalizationGroup();
   inline void SetTimeout(Local<Function> callback, Local<Context> context);
   inline MaybeLocal<Function> GetTimeoutCallback();
   inline MaybeLocal<Context> GetTimeoutContext();
@@ -245,7 +245,6 @@ class PerIsolateData {
   Global<Value> realm_shared_;
   std::queue<Global<Function>> set_timeout_callbacks_;
   std::queue<Global<Context>> set_timeout_contexts_;
-  std::queue<Global<FinalizationGroup>> cleanup_finalization_groups_;
   AsyncHooks* async_hooks_wrapper_;
 
   int RealmIndexOrThrow(const v8::FunctionCallbackInfo<v8::Value>& args,
@@ -299,6 +298,7 @@ class ShellOptions {
   bool include_arguments = true;
   bool cpu_profiler = false;
   bool cpu_profiler_print = false;
+  bool fuzzy_module_file_extensions = true;
 };
 
 class Shell : public i::AllStatic {
@@ -423,8 +423,6 @@ class Shell : public i::AllStatic {
   static void SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
-  static void HostCleanupFinalizationGroup(Local<Context> context,
-                                           Local<FinalizationGroup> fg);
   static MaybeLocal<Promise> HostImportModuleDynamically(
       Local<Context> context, Local<ScriptOrModule> referrer,
       Local<String> specifier);
@@ -461,6 +459,9 @@ class Shell : public i::AllStatic {
   static void AddRunningWorker(std::shared_ptr<Worker> worker);
   static void RemoveRunningWorker(const std::shared_ptr<Worker>& worker);
 
+  static void Initialize(Isolate* isolate, D8Console* console,
+                         bool isOnMainThread = true);
+
  private:
   static Global<Context> evaluation_context_;
   static base::OnceType quit_once_;
@@ -487,7 +488,6 @@ class Shell : public i::AllStatic {
   static void WriteLcovData(v8::Isolate* isolate, const char* file);
   static Counter* GetCounter(const char* name, bool is_histogram);
   static Local<String> Stringify(Isolate* isolate, Local<Value> value);
-  static void Initialize(Isolate* isolate);
   static void RunShell(Isolate* isolate);
   static bool SetOptions(int argc, char* argv[]);
   static Local<ObjectTemplate> CreateGlobalTemplate(Isolate* isolate);
diff --git a/deps/v8/src/date/date.cc b/deps/v8/src/date/date.cc
index 825c5040d3..250539e24c 100644
--- a/deps/v8/src/date/date.cc
+++ b/deps/v8/src/date/date.cc
@@ -66,7 +66,7 @@ void DateCache::ResetDateCache(
 // ECMA 262 - ES#sec-timeclip TimeClip (time)
 double DateCache::TimeClip(double time) {
   if (-kMaxTimeInMs <= time && time <= kMaxTimeInMs) {
-    return DoubleToInteger(time) + 0.0;
+    return DoubleToInteger(time);
   }
   return std::numeric_limits<double>::quiet_NaN();
 }
diff --git a/deps/v8/src/debug/arm64/debug-arm64.cc b/deps/v8/src/debug/arm64/debug-arm64.cc
index 96cd8a7b74..251856e284 100644
--- a/deps/v8/src/debug/arm64/debug-arm64.cc
+++ b/deps/v8/src/debug/arm64/debug-arm64.cc
@@ -38,7 +38,7 @@ void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
   __ Ldr(x1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
 
   __ Mov(sp, fp);
-  __ Pop(fp, lr);  // Frame, Return address.
+  __ Pop<TurboAssembler::kAuthLR>(fp, lr);
 
   __ LoadTaggedPointerField(
       x0, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
diff --git a/deps/v8/src/debug/debug-coverage.cc b/deps/v8/src/debug/debug-coverage.cc
index 5f368683f2..9b359fde36 100644
--- a/deps/v8/src/debug/debug-coverage.cc
+++ b/deps/v8/src/debug/debug-coverage.cc
@@ -74,9 +74,9 @@ std::vector<CoverageBlock> GetSortedBlockData(SharedFunctionInfo shared) {
       CoverageInfo::cast(shared.GetDebugInfo().coverage_info());
 
   std::vector<CoverageBlock> result;
-  if (coverage_info.SlotCount() == 0) return result;
+  if (coverage_info.slot_count() == 0) return result;
 
-  for (int i = 0; i < coverage_info.SlotCount(); i++) {
+  for (int i = 0; i < coverage_info.slot_count(); i++) {
     const int start_pos = coverage_info.StartSourcePosition(i);
     const int until_pos = coverage_info.EndSourcePosition(i);
     const int count = coverage_info.BlockCount(i);
@@ -385,7 +385,7 @@ void ResetAllBlockCounts(SharedFunctionInfo shared) {
   CoverageInfo coverage_info =
       CoverageInfo::cast(shared.GetDebugInfo().coverage_info());
 
-  for (int i = 0; i < coverage_info.SlotCount(); i++) {
+  for (int i = 0; i < coverage_info.slot_count(); i++) {
     coverage_info.ResetBlockCount(i);
   }
 }
diff --git a/deps/v8/src/debug/debug-evaluate.cc b/deps/v8/src/debug/debug-evaluate.cc
index 5a8b68305b..fcf9b8448a 100644
--- a/deps/v8/src/debug/debug-evaluate.cc
+++ b/deps/v8/src/debug/debug-evaluate.cc
@@ -265,6 +265,7 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   /* Type checks */                           \
   V(IsArray)                                  \
   V(IsFunction)                               \
+  V(IsJSProxy)                                \
   V(IsJSReceiver)                             \
   V(IsRegExp)                                 \
   V(IsSmi)                                    \
@@ -478,6 +479,7 @@ bool BytecodeHasNoSideEffect(interpreter::Bytecode bytecode) {
     case Bytecode::kForInContinue:
     case Bytecode::kForInNext:
     case Bytecode::kForInStep:
+    case Bytecode::kJumpLoop:
     case Bytecode::kThrow:
     case Bytecode::kReThrow:
     case Bytecode::kThrowReferenceErrorIfHole:
@@ -485,7 +487,6 @@ bool BytecodeHasNoSideEffect(interpreter::Bytecode bytecode) {
     case Bytecode::kThrowSuperAlreadyCalledIfNotHole:
     case Bytecode::kIllegal:
     case Bytecode::kCallJSRuntime:
-    case Bytecode::kStackCheck:
     case Bytecode::kReturn:
     case Bytecode::kSetPendingMessage:
       return true;
@@ -948,6 +949,7 @@ static bool TransitivelyCalledBuiltinHasNoSideEffect(Builtins::Name caller,
     case Builtins::kArraySomeLoopContinuation:
     case Builtins::kArrayTimSort:
     case Builtins::kCall_ReceiverIsAny:
+    case Builtins::kCall_ReceiverIsNotNullOrUndefined:
     case Builtins::kCall_ReceiverIsNullOrUndefined:
     case Builtins::kCallWithArrayLike:
     case Builtins::kCEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit:
@@ -991,7 +993,6 @@ static bool TransitivelyCalledBuiltinHasNoSideEffect(Builtins::Name caller,
     case Builtins::kStringIndexOf:
     case Builtins::kStringRepeat:
     case Builtins::kToInteger:
-    case Builtins::kToInteger_TruncateMinusZero:
     case Builtins::kToLength:
     case Builtins::kToName:
     case Builtins::kToObject:
@@ -1065,7 +1066,8 @@ void DebugEvaluate::VerifyTransitiveBuiltins(Isolate* isolate) {
     }
   }
   CHECK(!failed);
-#if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_MIPS64)
+#if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64) || \
+    defined(V8_TARGET_ARCH_MIPS64)
   // Isolate-independent builtin calls and jumps do not emit reloc infos
   // on PPC. We try to avoid using PC relative code due to performance
   // issue with especially older hardwares.
diff --git a/deps/v8/src/debug/debug-interface.h b/deps/v8/src/debug/debug-interface.h
index 732001327f..f6cfe31d32 100644
--- a/deps/v8/src/debug/debug-interface.h
+++ b/deps/v8/src/debug/debug-interface.h
@@ -101,6 +101,13 @@ void PrepareStep(Isolate* isolate, StepAction action);
 void ClearStepping(Isolate* isolate);
 V8_EXPORT_PRIVATE void BreakRightNow(Isolate* isolate);
 
+// Use `SetTerminateOnResume` to indicate that an TerminateExecution interrupt
+// should be set shortly before resuming, i.e. shortly before returning into
+// the JavaScript stack frames on the stack. In contrast to setting the
+// interrupt with `RequestTerminateExecution` directly, this flag allows
+// the isolate to be entered for further JavaScript execution.
+V8_EXPORT_PRIVATE void SetTerminateOnResume(Isolate* isolate);
+
 bool AllFramesOnStackAreBlackboxed(Isolate* isolate);
 
 class Script;
@@ -174,6 +181,9 @@ class WasmScript : public Script {
   int GetContainingFunction(int byte_offset) const;
 
   uint32_t GetFunctionHash(int function_index);
+
+  int CodeOffset() const;
+  int CodeLength() const;
 };
 
 V8_EXPORT_PRIVATE void GetLoadedScripts(
@@ -209,6 +219,9 @@ class DebugDelegate {
 V8_EXPORT_PRIVATE void SetDebugDelegate(Isolate* isolate,
                                         DebugDelegate* listener);
 
+V8_EXPORT_PRIVATE void TierDownAllModulesPerIsolate(Isolate* isolate);
+V8_EXPORT_PRIVATE void TierUpAllModulesPerIsolate(Isolate* isolate);
+
 class AsyncEventDelegate {
  public:
   virtual ~AsyncEventDelegate() = default;
@@ -410,7 +423,8 @@ class V8_EXPORT_PRIVATE ScopeIterator {
     ScopeTypeBlock,
     ScopeTypeScript,
     ScopeTypeEval,
-    ScopeTypeModule
+    ScopeTypeModule,
+    ScopeTypeWasmExpressionStack
   };
 
   virtual bool Done() = 0;
diff --git a/deps/v8/src/debug/debug-scope-iterator.cc b/deps/v8/src/debug/debug-scope-iterator.cc
index 1f6d9e0fd1..28d8ed0c8f 100644
--- a/deps/v8/src/debug/debug-scope-iterator.cc
+++ b/deps/v8/src/debug/debug-scope-iterator.cc
@@ -137,17 +137,24 @@ DebugWasmScopeIterator::DebugWasmScopeIterator(Isolate* isolate,
       type_(debug::ScopeIterator::ScopeTypeGlobal) {}
 
 bool DebugWasmScopeIterator::Done() {
-  return type_ != debug::ScopeIterator::ScopeTypeGlobal &&
-         type_ != debug::ScopeIterator::ScopeTypeLocal;
+  return type_ == debug::ScopeIterator::ScopeTypeWith;
 }
 
 void DebugWasmScopeIterator::Advance() {
   DCHECK(!Done());
-  if (type_ == debug::ScopeIterator::ScopeTypeGlobal) {
-    type_ = debug::ScopeIterator::ScopeTypeLocal;
-  } else {
-    // We use ScopeTypeWith type as marker for done.
-    type_ = debug::ScopeIterator::ScopeTypeWith;
+  switch (type_) {
+    case ScopeTypeGlobal:
+      type_ = debug::ScopeIterator::ScopeTypeLocal;
+      break;
+    case ScopeTypeLocal:
+      type_ = debug::ScopeIterator::ScopeTypeWasmExpressionStack;
+      break;
+    case ScopeTypeWasmExpressionStack:
+      // We use ScopeTypeWith type as marker for done.
+      type_ = debug::ScopeIterator::ScopeTypeWith;
+      break;
+    default:
+      UNREACHABLE();
   }
 }
 
@@ -176,7 +183,21 @@ v8::Local<v8::Object> DebugWasmScopeIterator::GetObject() {
       wasm::DebugInfo* debug_info =
           WasmCompiledFrame::cast(frame_)->native_module()->GetDebugInfo();
       return Utils::ToLocal(debug_info->GetLocalScopeObject(
-          isolate_, frame_->pc(), frame_->fp()));
+          isolate_, frame_->pc(), frame_->fp(), frame_->callee_fp()));
+    }
+    case debug::ScopeIterator::ScopeTypeWasmExpressionStack: {
+      if (frame_->is_wasm_interpreter_entry()) {
+        Handle<WasmDebugInfo> debug_info(
+            WasmInterpreterEntryFrame::cast(frame_)->debug_info(), isolate_);
+        return Utils::ToLocal(WasmDebugInfo::GetStackScopeObject(
+            debug_info, frame_->fp(), inlined_frame_index_));
+      }
+      // Compiled code.
+      DCHECK(frame_->is_wasm_compiled());
+      wasm::DebugInfo* debug_info =
+          WasmCompiledFrame::cast(frame_)->native_module()->GetDebugInfo();
+      return Utils::ToLocal(debug_info->GetStackScopeObject(
+          isolate_, frame_->pc(), frame_->fp(), frame_->callee_fp()));
     }
     default:
       return {};
diff --git a/deps/v8/src/debug/debug-scopes.cc b/deps/v8/src/debug/debug-scopes.cc
index 58182941c8..c5061ecb81 100644
--- a/deps/v8/src/debug/debug-scopes.cc
+++ b/deps/v8/src/debug/debug-scopes.cc
@@ -244,10 +244,11 @@ void ScopeIterator::TryParseAndRetrieveScopes(ReparseStrategy strategy) {
     info_->set_eager();
   }
 
+  MaybeHandle<ScopeInfo> maybe_outer_scope;
   if (scope_info->scope_type() == EVAL_SCOPE || script->is_wrapped()) {
     info_->set_eval();
     if (!context_->IsNativeContext()) {
-      info_->set_outer_scope_info(handle(context_->scope_info(), isolate_));
+      maybe_outer_scope = handle(context_->scope_info(), isolate_);
     }
     // Language mode may be inherited from the eval caller.
     // Retrieve it from shared function info.
@@ -259,9 +260,13 @@ void ScopeIterator::TryParseAndRetrieveScopes(ReparseStrategy strategy) {
            scope_info->scope_type() == FUNCTION_SCOPE);
   }
 
-  if (parsing::ParseAny(info_, shared_info, isolate_) &&
-      Rewriter::Rewrite(info_)) {
-    info_->ast_value_factory()->Internalize(isolate_->factory());
+  const bool parse_result =
+      info_->is_toplevel()
+          ? parsing::ParseProgram(info_, script, maybe_outer_scope, isolate_)
+          : parsing::ParseFunction(info_, shared_info, isolate_);
+
+  if (parse_result && Rewriter::Rewrite(info_)) {
+    info_->ast_value_factory()->Internalize(isolate_);
     DeclarationScope* literal_scope = info_->literal()->scope();
 
     ScopeChainRetriever scope_chain_retriever(literal_scope, function_,
diff --git a/deps/v8/src/debug/debug.cc b/deps/v8/src/debug/debug.cc
index 449ac490d0..a7a3d2fd81 100644
--- a/deps/v8/src/debug/debug.cc
+++ b/deps/v8/src/debug/debug.cc
@@ -37,6 +37,7 @@
 #include "src/objects/js-promise-inl.h"
 #include "src/objects/slots.h"
 #include "src/snapshot/snapshot.h"
+#include "src/wasm/wasm-debug.h"
 #include "src/wasm/wasm-objects-inl.h"
 
 namespace v8 {
@@ -871,8 +872,9 @@ void Debug::PrepareStepIn(Handle<JSFunction> function) {
   if (in_debug_scope()) return;
   if (break_disabled()) return;
   Handle<SharedFunctionInfo> shared(function->shared(), isolate_);
-  // If stepping from JS into Wasm, prepare for it.
-  if (shared->HasWasmExportedFunctionData()) {
+  // If stepping from JS into Wasm, and we are using the wasm interpreter for
+  // debugging, prepare the interpreter for step in.
+  if (shared->HasWasmExportedFunctionData() && !FLAG_debug_in_liftoff) {
     auto imported_function = Handle<WasmExportedFunction>::cast(function);
     Handle<WasmInstanceObject> wasm_instance(imported_function->instance(),
                                              isolate_);
@@ -995,19 +997,6 @@ void Debug::PrepareStep(StepAction step_action) {
   StackTraceFrameIterator frames_it(isolate_, frame_id);
   StandardFrame* frame = frames_it.frame();
 
-  // Handle stepping in wasm functions via the wasm interpreter.
-  if (frame->is_wasm_interpreter_entry()) {
-    WasmInterpreterEntryFrame* wasm_frame =
-        WasmInterpreterEntryFrame::cast(frame);
-    if (wasm_frame->NumberOfActiveFrames() > 0) {
-      wasm_frame->debug_info().PrepareStep(step_action);
-      return;
-    }
-  }
-  // If this is wasm, but there are no interpreted frames on top, all we can do
-  // is step out.
-  if (frame->is_wasm()) step_action = StepOut;
-
   BreakLocation location = BreakLocation::Invalid();
   Handle<SharedFunctionInfo> shared;
   int current_frame_count = CurrentFrameCount();
@@ -1051,6 +1040,26 @@ void Debug::PrepareStep(StepAction step_action) {
     thread_local_.last_frame_count_ = current_frame_count;
     // No longer perform the current async step.
     clear_suspended_generator();
+  } else if (frame->is_wasm_interpreter_entry()) {
+    // Handle stepping in wasm functions via the wasm interpreter.
+    WasmInterpreterEntryFrame* wasm_frame =
+        WasmInterpreterEntryFrame::cast(frame);
+    if (wasm_frame->NumberOfActiveFrames() > 0) {
+      wasm_frame->debug_info().PrepareStep(step_action);
+      return;
+    }
+  } else if (FLAG_debug_in_liftoff && frame->is_wasm_compiled()) {
+    // Handle stepping in Liftoff code.
+    WasmCompiledFrame* wasm_frame = WasmCompiledFrame::cast(frame);
+    wasm::WasmCodeRefScope code_ref_scope;
+    wasm::WasmCode* code = wasm_frame->wasm_code();
+    if (code->is_liftoff()) {
+      wasm_frame->native_module()->GetDebugInfo()->PrepareStep(isolate_,
+                                                               frame_id);
+    }
+    // In case the wasm code returns, prepare the next frame (if JS) to break.
+    step_action = StepOut;
+    UpdateHookOnFunctionCall();
   }
 
   switch (step_action) {
@@ -1718,8 +1727,8 @@ Handle<FixedArray> Debug::GetLoadedScripts() {
   return FixedArray::ShrinkOrEmpty(isolate_, results, length);
 }
 
-void Debug::OnThrow(Handle<Object> exception) {
-  if (in_debug_scope() || ignore_events()) return;
+base::Optional<Object> Debug::OnThrow(Handle<Object> exception) {
+  if (in_debug_scope() || ignore_events()) return {};
   // Temporarily clear any scheduled_exception to allow evaluating
   // JavaScript from the debug event handler.
   HandleScope scope(isolate_);
@@ -1736,6 +1745,14 @@ void Debug::OnThrow(Handle<Object> exception) {
     isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
   }
   PrepareStepOnThrow();
+  // If the OnException handler requested termination, then indicated this to
+  // our caller Isolate::Throw so it can deal with it immediatelly instead of
+  // throwing the original exception.
+  if (isolate_->stack_guard()->CheckTerminateExecution()) {
+    isolate_->stack_guard()->ClearTerminateExecution();
+    return isolate_->TerminateExecution();
+  }
+  return {};
 }
 
 void Debug::OnPromiseReject(Handle<Object> promise, Handle<Object> value) {
@@ -2060,7 +2077,7 @@ void Debug::PrintBreakLocation() {
   if (script_obj->IsScript()) {
     Handle<Script> script = Handle<Script>::cast(script_obj);
     Handle<String> source(String::cast(script->source()), isolate_);
-    Script::InitLineEnds(script);
+    Script::InitLineEnds(isolate_, script);
     int line =
         Script::GetLineNumber(script, source_position) - script->line_offset();
     int column = Script::GetColumnNumber(script, source_position) -
@@ -2092,7 +2109,6 @@ DebugScope::DebugScope(Debug* debug)
   // Link recursive debugger entry.
   base::Relaxed_Store(&debug_->thread_local_.current_debug_scope_,
                       reinterpret_cast<base::AtomicWord>(this));
-
   // Store the previous frame id and return value.
   break_frame_id_ = debug_->break_frame_id();
 
@@ -2106,8 +2122,18 @@ DebugScope::DebugScope(Debug* debug)
   debug_->UpdateState();
 }
 
+void DebugScope::set_terminate_on_resume() { terminate_on_resume_ = true; }
 
 DebugScope::~DebugScope() {
+  // Terminate on resume must have been handled by retrieving it, if this is
+  // the outer scope.
+  if (terminate_on_resume_) {
+    if (!prev_) {
+      debug_->isolate_->stack_guard()->RequestTerminateExecution();
+    } else {
+      prev_->set_terminate_on_resume();
+    }
+  }
   // Leaving this debugger entry.
   base::Relaxed_Store(&debug_->thread_local_.current_debug_scope_,
                       reinterpret_cast<base::AtomicWord>(prev_));
@@ -2147,6 +2173,13 @@ void Debug::UpdateDebugInfosForExecutionMode() {
   }
 }
 
+void Debug::SetTerminateOnResume() {
+  DebugScope* scope = reinterpret_cast<DebugScope*>(
+      base::Acquire_Load(&thread_local_.current_debug_scope_));
+  CHECK_NOT_NULL(scope);
+  scope->set_terminate_on_resume();
+}
+
 void Debug::StartSideEffectCheckMode() {
   DCHECK(isolate_->debug_execution_mode() != DebugInfo::kSideEffects);
   isolate_->set_debug_execution_mode(DebugInfo::kSideEffects);
diff --git a/deps/v8/src/debug/debug.h b/deps/v8/src/debug/debug.h
index 8a63b1044e..4bb2008c4d 100644
--- a/deps/v8/src/debug/debug.h
+++ b/deps/v8/src/debug/debug.h
@@ -217,7 +217,8 @@ class V8_EXPORT_PRIVATE Debug {
   // Debug event triggers.
   void OnDebugBreak(Handle<FixedArray> break_points_hit);
 
-  void OnThrow(Handle<Object> exception);
+  base::Optional<Object> OnThrow(Handle<Object> exception)
+      V8_WARN_UNUSED_RESULT;
   void OnPromiseReject(Handle<Object> promise, Handle<Object> value);
   void OnCompileError(Handle<Script> script);
   void OnAfterCompile(Handle<Script> script);
@@ -238,6 +239,8 @@ class V8_EXPORT_PRIVATE Debug {
   void ChangeBreakOnException(ExceptionBreakType type, bool enable);
   bool IsBreakOnException(ExceptionBreakType type);
 
+  void SetTerminateOnResume();
+
   bool SetBreakPointForScript(Handle<Script> script, Handle<String> condition,
                               int* source_position, int* id);
   bool SetBreakpointForFunction(Handle<SharedFunctionInfo> shared,
@@ -564,6 +567,8 @@ class DebugScope {
   explicit DebugScope(Debug* debug);
   ~DebugScope();
 
+  void set_terminate_on_resume();
+
  private:
   Isolate* isolate() { return debug_->isolate_; }
 
@@ -571,6 +576,8 @@ class DebugScope {
   DebugScope* prev_;               // Previous scope if entered recursively.
   StackFrameId break_frame_id_;    // Previous break frame id.
   PostponeInterruptsScope no_interrupts_;
+  // This is used as a boolean.
+  bool terminate_on_resume_ = false;
 };
 
 // This scope is used to handle return values in nested debug break points.
diff --git a/deps/v8/src/debug/liveedit.cc b/deps/v8/src/debug/liveedit.cc
index 99063ba8f6..aad5f5d9e6 100644
--- a/deps/v8/src/debug/liveedit.cc
+++ b/deps/v8/src/debug/liveedit.cc
@@ -761,7 +761,7 @@ bool ParseScript(Isolate* isolate, Handle<Script> script, ParseInfo* parse_info,
     success = parsing::ParseProgram(parse_info, script, isolate);
     if (success) {
       success = Compiler::Analyze(parse_info);
-      parse_info->ast_value_factory()->Internalize(isolate->factory());
+      parse_info->ast_value_factory()->Internalize(isolate);
     }
   }
   if (!success) {
diff --git a/deps/v8/src/debug/ppc/debug-ppc.cc b/deps/v8/src/debug/ppc/debug-ppc.cc
index d06aa67bb8..be32d3ba28 100644
--- a/deps/v8/src/debug/ppc/debug-ppc.cc
+++ b/deps/v8/src/debug/ppc/debug-ppc.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/debug/debug.h"
 
@@ -50,4 +50,4 @@ const bool LiveEdit::kFrameDropperSupported = true;
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/debug/s390/debug-s390.cc b/deps/v8/src/debug/s390/debug-s390.cc
index 0230fcaa83..7d08e13678 100644
--- a/deps/v8/src/debug/s390/debug-s390.cc
+++ b/deps/v8/src/debug/s390/debug-s390.cc
@@ -38,7 +38,8 @@ void DebugCodegen::GenerateFrameDropperTrampoline(MacroAssembler* masm) {
   __ LoadRR(fp, r3);
   __ LoadP(r3, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
   __ LeaveFrame(StackFrame::INTERNAL);
-  __ LoadP(r2, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
+  __ LoadTaggedPointerField(
+      r2, FieldMemOperand(r3, JSFunction::kSharedFunctionInfoOffset));
   __ LoadLogicalHalfWordP(
       r2, FieldMemOperand(r2, SharedFunctionInfo::kFormalParameterCountOffset));
   __ LoadRR(r4, r2);
diff --git a/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.cc b/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.cc
new file mode 100644
index 0000000000..a9f1b58f6c
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.cc
@@ -0,0 +1,118 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/debug/wasm/gdb-server/gdb-server-thread.h"
+#include "src/debug/wasm/gdb-server/gdb-server.h"
+#include "src/debug/wasm/gdb-server/session.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+GdbServerThread::GdbServerThread(GdbServer* gdb_server)
+    : Thread(v8::base::Thread::Options("GdbServerThread")),
+      gdb_server_(gdb_server),
+      start_semaphore_(0) {}
+
+bool GdbServerThread::StartAndInitialize() {
+  // Executed in the Isolate thread.
+  if (!Start()) {
+    return false;
+  }
+
+  // We need to make sure that {Stop} is never called before the thread has
+  // completely initialized {transport_} and {target_}. Otherwise there could be
+  // a race condition where in the main thread {Stop} might get called before
+  // the transport is created, and then in the GDBServer thread we may have time
+  // to setup the transport and block on accept() before the main thread blocks
+  // on joining the thread.
+  // The small performance hit caused by this Wait should be negligeable because
+  // this operation happensat most once per process and only when the
+  // --wasm-gdb-remote flag is set.
+  start_semaphore_.Wait();
+  return true;
+}
+
+void GdbServerThread::CleanupThread() {
+  // Executed in the GdbServer thread.
+  v8::base::MutexGuard guard(&mutex_);
+
+  target_ = nullptr;
+  transport_ = nullptr;
+
+#if _WIN32
+  ::WSACleanup();
+#endif
+}
+
+void GdbServerThread::Run() {
+  // Executed in the GdbServer thread.
+#ifdef _WIN32
+  // Initialize Winsock
+  WSADATA wsaData;
+  int iResult = ::WSAStartup(MAKEWORD(2, 2), &wsaData);
+  if (iResult != 0) {
+    TRACE_GDB_REMOTE("GdbServerThread::Run: WSAStartup failed\n");
+    return;
+  }
+#endif
+
+  // If the default port is not available, try any port.
+  SocketBinding socket_binding = SocketBinding::Bind(FLAG_wasm_gdb_remote_port);
+  if (!socket_binding.IsValid()) {
+    socket_binding = SocketBinding::Bind(0);
+  }
+  if (!socket_binding.IsValid()) {
+    TRACE_GDB_REMOTE("GdbServerThread::Run: Failed to bind any TCP port\n");
+    return;
+  }
+  TRACE_GDB_REMOTE("gdb-remote(%d) : Connect GDB with 'target remote :%d\n",
+                   __LINE__, socket_binding.GetBoundPort());
+
+  transport_ = socket_binding.CreateTransport();
+  target_ = std::make_unique<Target>(gdb_server_);
+
+  // Here we have completed the initialization, and the thread that called
+  // {StartAndInitialize} may resume execution.
+  start_semaphore_.Signal();
+
+  while (!target_->IsTerminated()) {
+    // Wait for incoming connections.
+    if (!transport_->AcceptConnection()) {
+      continue;
+    }
+
+    // Create a new session for this connection
+    Session session(transport_.get());
+    TRACE_GDB_REMOTE("GdbServerThread: Connected\n");
+
+    // Run this session for as long as it lasts
+    target_->Run(&session);
+  }
+  CleanupThread();
+}
+
+void GdbServerThread::Stop() {
+  // Executed in the Isolate thread.
+
+  // Synchronized, becauses {Stop} might be called while {Run} is still
+  // initializing {transport_} and {target_}. If this happens and the thread is
+  // blocked waiting for an incoming connection or GdbServer for incoming
+  // packets, it will unblocked when {transport_} is closed.
+  v8::base::MutexGuard guard(&mutex_);
+
+  if (target_) {
+    target_->Terminate();
+  }
+
+  if (transport_) {
+    transport_->Close();
+  }
+}
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.h b/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.h
new file mode 100644
index 0000000000..f31756cbb3
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/gdb-server-thread.h
@@ -0,0 +1,61 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_THREAD_H_
+#define V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_THREAD_H_
+
+#include "src/base/platform/platform.h"
+#include "src/base/platform/semaphore.h"
+#include "src/debug/wasm/gdb-server/target.h"
+#include "src/debug/wasm/gdb-server/transport.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+class GdbServer;
+
+// class GdbServerThread spawns a thread where all communication with a debugger
+// happens.
+class GdbServerThread : public v8::base::Thread {
+ public:
+  explicit GdbServerThread(GdbServer* gdb_server);
+
+  // base::Thread
+  void Run() override;
+
+  // Starts the GDB-server thread and waits Run() method is called on the new
+  // thread and the initialization completes.
+  bool StartAndInitialize();
+
+  // Stops the GDB-server thread when the V8 process shuts down; gracefully
+  // closes any active debugging session.
+  void Stop();
+
+ private:
+  void CleanupThread();
+
+  GdbServer* gdb_server_;
+
+  // Used to block the caller on StartAndInitialize() waiting for the new thread
+  // to have completed its initialization.
+  // (Note that Thread::StartSynchronously() wouldn't work in this case because
+  // it returns as soon as the new thread starts, but before Run() is called).
+  base::Semaphore start_semaphore_;
+
+  base::Mutex mutex_;
+  // Protected by {mutex_}:
+  std::unique_ptr<Transport> transport_;
+  std::unique_ptr<Target> target_;
+
+  DISALLOW_COPY_AND_ASSIGN(GdbServerThread);
+};
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_THREAD_H_
diff --git a/deps/v8/src/debug/wasm/gdb-server/gdb-server.cc b/deps/v8/src/debug/wasm/gdb-server/gdb-server.cc
new file mode 100644
index 0000000000..bad7f439eb
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/gdb-server.cc
@@ -0,0 +1,38 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/debug/wasm/gdb-server/gdb-server.h"
+
+#include "src/debug/wasm/gdb-server/gdb-server-thread.h"
+#include "src/wasm/wasm-engine.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+GdbServer::GdbServer() {
+  DCHECK(!thread_);
+  DCHECK(FLAG_wasm_gdb_remote);
+
+  thread_ = std::make_unique<GdbServerThread>(this);
+  // TODO(paolosev): does StartSynchronously hurt performances?
+  if (!thread_->StartAndInitialize()) {
+    TRACE_GDB_REMOTE(
+        "Cannot initialize thread, GDB-remote debugging will be disabled.\n");
+    thread_ = nullptr;
+  }
+}
+
+GdbServer::~GdbServer() {
+  if (thread_) {
+    thread_->Stop();
+    thread_->Join();
+  }
+}
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/debug/wasm/gdb-server/gdb-server.h b/deps/v8/src/debug/wasm/gdb-server/gdb-server.h
new file mode 100644
index 0000000000..59d8a17375
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/gdb-server.h
@@ -0,0 +1,43 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
+#define V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
+
+#include <memory>
+#include "src/debug/wasm/gdb-server/gdb-server-thread.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+// class GdbServer acts as a manager for the GDB-remote stub. It is instantiated
+// as soon as the first Wasm module is loaded in the Wasm engine and spawns a
+// separate thread to accept connections and exchange messages with a debugger.
+// It will contain the logic to serve debugger queries and access the state of
+// the Wasm engine.
+class GdbServer {
+ public:
+  // Spawns a "GDB-remote" thread that will be used to communicate with the
+  // debugger. This should be called once, the first time a Wasm module is
+  // loaded in the Wasm engine.
+  GdbServer();
+
+  // Stops the "GDB-remote" thread and waits for it to complete. This should be
+  // called once, when the Wasm engine shuts down.
+  ~GdbServer();
+
+ private:
+  std::unique_ptr<GdbServerThread> thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(GdbServer);
+};
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_GDB_SERVER_H_
diff --git a/deps/v8/src/debug/wasm/gdb-server/session.cc b/deps/v8/src/debug/wasm/gdb-server/session.cc
new file mode 100644
index 0000000000..3e98e093af
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/session.cc
@@ -0,0 +1,48 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/debug/wasm/gdb-server/session.h"
+#include "src/debug/wasm/gdb-server/transport.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+Session::Session(Transport* transport) : io_(transport), connected_(true) {}
+
+void Session::WaitForDebugStubEvent() { io_->WaitForDebugStubEvent(); }
+
+bool Session::SignalThreadEvent() { return io_->SignalThreadEvent(); }
+
+bool Session::IsDataAvailable() const { return io_->IsDataAvailable(); }
+
+bool Session::IsConnected() const { return connected_; }
+
+void Session::Disconnect() {
+  io_->Disconnect();
+  connected_ = false;
+}
+
+bool Session::GetChar(char* ch) {
+  if (!io_->Read(ch, 1)) {
+    Disconnect();
+    return false;
+  }
+
+  return true;
+}
+
+bool Session::GetPacket() {
+  char ch;
+  if (!GetChar(&ch)) return false;
+
+  // discard the input
+  return true;
+}
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/debug/wasm/gdb-server/session.h b/deps/v8/src/debug/wasm/gdb-server/session.h
new file mode 100644
index 0000000000..a76bb4a3b4
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/session.h
@@ -0,0 +1,59 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_SESSION_H_
+#define V8_DEBUG_WASM_GDB_SERVER_SESSION_H_
+
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+class Transport;
+
+// Represents a gdb-remote debugging session.
+class Session {
+ public:
+  explicit Session(Transport* transport);
+
+  // Attempt to receive a packet.
+  // For the moment this method is only used to check whether the TCP connection
+  // is still active; all bytes read are discarded.
+  bool GetPacket();
+
+  // Return true if there is data to read.
+  bool IsDataAvailable() const;
+
+  // Return true if the connection still valid.
+  bool IsConnected() const;
+
+  // Shutdown the connection.
+  void Disconnect();
+
+  // When a debugging session is active, the GDB-remote thread can block waiting
+  // for events and it will resume execution when one of these two events arise:
+  // - A network event (a new packet arrives, or the connection is dropped)
+  // - A thread event (the execution stopped because of a trap or breakpoint).
+  void WaitForDebugStubEvent();
+
+  // Signal that the debuggee execution stopped because of a trap or breakpoint.
+  bool SignalThreadEvent();
+
+ private:
+  bool GetChar(char* ch);
+
+  Transport* io_;   // Transport object not owned by the Session.
+  bool connected_;  // Is the connection still valid.
+
+  DISALLOW_COPY_AND_ASSIGN(Session);
+};
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_SESSION_H_
diff --git a/deps/v8/src/debug/wasm/gdb-server/target.cc b/deps/v8/src/debug/wasm/gdb-server/target.cc
new file mode 100644
index 0000000000..ac5bf10a0e
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/target.cc
@@ -0,0 +1,65 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/debug/wasm/gdb-server/target.h"
+
+#include "src/base/platform/time.h"
+#include "src/debug/wasm/gdb-server/gdb-server.h"
+#include "src/debug/wasm/gdb-server/session.h"
+#include "src/debug/wasm/gdb-server/transport.h"
+#include "src/debug/wasm/gdb-server/util.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+Target::Target(GdbServer* gdb_server)
+    : status_(Status::Running), session_(nullptr) {}
+
+void Target::Terminate() {
+  // Executed in the Isolate thread.
+  status_ = Status::Terminated;
+}
+
+void Target::Run(Session* session) {
+  // Executed in the GdbServer thread.
+
+  session_ = session;
+  do {
+    WaitForDebugEvent();
+    ProcessCommands();
+  } while (!IsTerminated() && session_->IsConnected());
+  session_ = nullptr;
+}
+
+void Target::WaitForDebugEvent() {
+  // Executed in the GdbServer thread.
+
+  if (status_ != Status::Terminated) {
+    // Wait for either:
+    //   * the thread to fault (or single-step)
+    //   * an interrupt from LLDB
+    session_->WaitForDebugStubEvent();
+  }
+}
+
+void Target::ProcessCommands() {
+  // GDB-remote messages are processed in the GDBServer thread.
+
+  if (IsTerminated()) {
+    return;
+  }
+
+  // TODO(paolosev)
+  // For the moment just discard any packet we receive from the debugger.
+  do {
+    if (!session_->GetPacket()) continue;
+  } while (session_->IsConnected());
+}
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/debug/wasm/gdb-server/target.h b/deps/v8/src/debug/wasm/gdb-server/target.h
new file mode 100644
index 0000000000..93d02489c5
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/target.h
@@ -0,0 +1,57 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_TARGET_H_
+#define V8_DEBUG_WASM_GDB_SERVER_TARGET_H_
+
+#include <atomic>
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+class GdbServer;
+class Session;
+
+// Class Target represents a debugging target. It contains the logic to decode
+// incoming GDB-remote packets, execute them forwarding the debugger commands
+// and queries to the Wasm engine, and send back GDB-remote packets.
+class Target {
+ public:
+  // Contruct a Target object.
+  explicit Target(GdbServer* gdb_server);
+
+  // This function spin on a debugging session, until it closes.
+  void Run(Session* ses);
+
+  void Terminate();
+  bool IsTerminated() const { return status_ == Status::Terminated; }
+
+ private:
+  // Blocks waiting for one of these two events to occur:
+  // - A network packet arrives from the debugger, or the debugger connection is
+  //   closed;
+  // - The debuggee suspends execution because of a trap or breakpoint.
+  void WaitForDebugEvent();
+
+  // Processes GDB-remote packets that arrive from the debugger.
+  // This method should be called when the debuggee has suspended its execution.
+  void ProcessCommands();
+
+  enum class Status { Running, Terminated };
+  std::atomic<Status> status_;
+
+  Session* session_;  // Session object not owned by the Target.
+
+  DISALLOW_COPY_AND_ASSIGN(Target);
+};
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_TARGET_H_
diff --git a/deps/v8/src/debug/wasm/gdb-server/transport.cc b/deps/v8/src/debug/wasm/gdb-server/transport.cc
new file mode 100644
index 0000000000..385828ff69
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/transport.cc
@@ -0,0 +1,444 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/debug/wasm/gdb-server/transport.h"
+#include <fcntl.h>
+
+#ifndef SD_BOTH
+#define SD_BOTH 2
+#endif
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+SocketBinding::SocketBinding(SocketHandle socket_handle)
+    : socket_handle_(socket_handle) {}
+
+// static
+SocketBinding SocketBinding::Bind(uint16_t tcp_port) {
+  SocketHandle socket_handle = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+  if (socket_handle == InvalidSocket) {
+    TRACE_GDB_REMOTE("Failed to create socket.\n");
+    return SocketBinding(InvalidSocket);
+  }
+  struct sockaddr_in sockaddr;
+  // Clearing sockaddr_in first appears to be necessary on Mac OS X.
+  memset(&sockaddr, 0, sizeof(sockaddr));
+  socklen_t addrlen = static_cast<socklen_t>(sizeof(sockaddr));
+  sockaddr.sin_family = AF_INET;
+  sockaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+  sockaddr.sin_port = htons(tcp_port);
+
+#if _WIN32
+  // On Windows, SO_REUSEADDR has a different meaning than on POSIX systems.
+  // SO_REUSEADDR allows hijacking of an open socket by another process.
+  // The SO_EXCLUSIVEADDRUSE flag prevents this behavior.
+  // See:
+  // http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621(v=vs.85).aspx
+  //
+  // Additionally, unlike POSIX, TCP server sockets can be bound to
+  // ports in the TIME_WAIT state, without setting SO_REUSEADDR.
+  int exclusive_address = 1;
+  if (setsockopt(socket_handle, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
+                 reinterpret_cast<char*>(&exclusive_address),
+                 sizeof(exclusive_address))) {
+    TRACE_GDB_REMOTE("Failed to set SO_EXCLUSIVEADDRUSE option.\n");
+  }
+#else
+  // On POSIX, this is necessary to ensure that the TCP port is released
+  // promptly when sel_ldr exits.  Without this, the TCP port might
+  // only be released after a timeout, and later processes can fail
+  // to bind it.
+  int reuse_address = 1;
+  if (setsockopt(socket_handle, SOL_SOCKET, SO_REUSEADDR,
+                 reinterpret_cast<char*>(&reuse_address),
+                 sizeof(reuse_address))) {
+    TRACE_GDB_REMOTE("Failed to set SO_REUSEADDR option.\n");
+  }
+#endif
+
+  if (bind(socket_handle, reinterpret_cast<struct sockaddr*>(&sockaddr),
+           addrlen)) {
+    TRACE_GDB_REMOTE("Failed to bind server.\n");
+    return SocketBinding(InvalidSocket);
+  }
+
+  if (listen(socket_handle, 1)) {
+    TRACE_GDB_REMOTE("Failed to listen.\n");
+    return SocketBinding(InvalidSocket);
+  }
+  return SocketBinding(socket_handle);
+}
+
+std::unique_ptr<Transport> SocketBinding::CreateTransport() {
+  return std::make_unique<Transport>(socket_handle_);
+}
+
+uint16_t SocketBinding::GetBoundPort() {
+  struct sockaddr_in saddr;
+  struct sockaddr* psaddr = reinterpret_cast<struct sockaddr*>(&saddr);
+  // Clearing sockaddr_in first appears to be necessary on Mac OS X.
+  memset(&saddr, 0, sizeof(saddr));
+  socklen_t addrlen = static_cast<socklen_t>(sizeof(saddr));
+  if (::getsockname(socket_handle_, psaddr, &addrlen)) {
+    TRACE_GDB_REMOTE("Failed to retrieve bound address.\n");
+    return 0;
+  }
+  return ntohs(saddr.sin_port);
+}
+
+// Do not delay sending small packets.  This significantly speeds up
+// remote debugging.  Debug stub uses buffering to send outgoing packets
+// so they are not split into more TCP packets than necessary.
+void DisableNagleAlgorithm(SocketHandle socket) {
+  int nodelay = 1;
+  if (::setsockopt(socket, IPPROTO_TCP, TCP_NODELAY,
+                   reinterpret_cast<char*>(&nodelay), sizeof(nodelay))) {
+    TRACE_GDB_REMOTE("Failed to set TCP_NODELAY option.\n");
+  }
+}
+
+TransportBase::TransportBase(SocketHandle s)
+    : buf_(new char[kBufSize]),
+      pos_(0),
+      size_(0),
+      handle_bind_(s),
+      handle_accept_(InvalidSocket) {}
+
+TransportBase::~TransportBase() {
+  if (handle_accept_ != InvalidSocket) {
+    CloseSocket(handle_accept_);
+  }
+}
+
+void TransportBase::CopyFromBuffer(char** dst, int32_t* len) {
+  int32_t copy_bytes = std::min(*len, size_ - pos_);
+  memcpy(*dst, buf_.get() + pos_, copy_bytes);
+  pos_ += copy_bytes;
+  *len -= copy_bytes;
+  *dst += copy_bytes;
+}
+
+bool TransportBase::Read(char* dst, int32_t len) {
+  if (pos_ < size_) {
+    CopyFromBuffer(&dst, &len);
+  }
+  while (len > 0) {
+    pos_ = 0;
+    size_ = 0;
+    if (!ReadSomeData()) {
+      return false;
+    }
+    CopyFromBuffer(&dst, &len);
+  }
+  return true;
+}
+
+bool TransportBase::Write(const char* src, int32_t len) {
+  while (len > 0) {
+    ssize_t result = ::send(handle_accept_, src, len, 0);
+    if (result > 0) {
+      src += result;
+      len -= result;
+      continue;
+    }
+    if (result == 0) {
+      return false;
+    }
+    if (SocketGetLastError() != kErrInterrupt) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// Return true if there is data to read.
+bool TransportBase::IsDataAvailable() const {
+  if (pos_ < size_) {
+    return true;
+  }
+  fd_set fds;
+
+  FD_ZERO(&fds);
+  FD_SET(handle_accept_, &fds);
+
+  // We want a "non-blocking" check
+  struct timeval timeout;
+  timeout.tv_sec = 0;
+  timeout.tv_usec = 0;
+
+  // Check if this file handle can select on read
+  int cnt = select(static_cast<int>(handle_accept_) + 1, &fds, 0, 0, &timeout);
+
+  // If we are ready, or if there is an error.  We return true
+  // on error, to let the next IO request fail.
+  if (cnt != 0) return true;
+
+  return false;
+}
+
+void TransportBase::Close() {
+  ::shutdown(handle_bind_, SD_BOTH);
+  CloseSocket(handle_bind_);
+  Disconnect();
+}
+
+void TransportBase::Disconnect() {
+  if (handle_accept_ != InvalidSocket) {
+    // Shutdown the connection in both directions.  This should
+    // always succeed, and nothing we can do if this fails.
+    ::shutdown(handle_accept_, SD_BOTH);
+
+    CloseSocket(handle_accept_);
+    handle_accept_ = InvalidSocket;
+  }
+}
+
+#if _WIN32
+
+Transport::Transport(SocketHandle s) : TransportBase(s) {
+  socket_event_ = WSA_INVALID_EVENT;
+  faulted_thread_event_ = ::CreateEvent(NULL, TRUE, FALSE, NULL);
+  if (faulted_thread_event_ == NULL) {
+    TRACE_GDB_REMOTE(
+        "Transport::Transport: Failed to create event object for faulted"
+        "thread\n");
+  }
+}
+
+Transport::~Transport() {
+  if (!CloseHandle(faulted_thread_event_)) {
+    TRACE_GDB_REMOTE("Transport::~Transport: Failed to close event\n");
+  }
+
+  if (socket_event_) {
+    if (!::WSACloseEvent(socket_event_)) {
+      TRACE_GDB_REMOTE("Transport::~Transport: Failed to close socket event\n");
+    }
+  }
+}
+
+bool Transport::AcceptConnection() {
+  CHECK(handle_accept_ == InvalidSocket);
+  handle_accept_ = ::accept(handle_bind_, NULL, 0);
+  if (handle_accept_ != InvalidSocket) {
+    DisableNagleAlgorithm(handle_accept_);
+
+    // Create socket event
+    socket_event_ = ::WSACreateEvent();
+    if (socket_event_ == WSA_INVALID_EVENT) {
+      TRACE_GDB_REMOTE(
+          "Transport::AcceptConnection: Failed to create socket event\n");
+    }
+
+    // Listen for close events in order to handle them correctly.
+    // Additionally listen for read readiness as WSAEventSelect sets the socket
+    // to non-blocking mode.
+    // http://msdn.microsoft.com/en-us/library/windows/desktop/ms738547(v=vs.85).aspx
+    if (::WSAEventSelect(handle_accept_, socket_event_, FD_CLOSE | FD_READ) ==
+        SOCKET_ERROR) {
+      TRACE_GDB_REMOTE(
+          "Transport::AcceptConnection: Failed to bind event to socket\n");
+    }
+    return true;
+  }
+  return false;
+}
+
+bool Transport::ReadSomeData() {
+  while (true) {
+    ssize_t result =
+        ::recv(handle_accept_, buf_.get() + size_, kBufSize - size_, 0);
+    if (result > 0) {
+      size_ += result;
+      return true;
+    }
+    if (result == 0) {
+      return false;  // The connection was gracefully closed.
+    }
+
+    // WSAEventSelect sets socket to non-blocking mode. This is essential
+    // for socket event notification to work, there is no workaround.
+    // See remarks section at the page
+    // http://msdn.microsoft.com/en-us/library/windows/desktop/ms741576(v=vs.85).aspx
+    if (SocketGetLastError() == WSAEWOULDBLOCK) {
+      if (::WaitForSingleObject(socket_event_, INFINITE) == WAIT_FAILED) {
+        TRACE_GDB_REMOTE(
+            "Transport::ReadSomeData: Failed to wait on socket event\n");
+      }
+      if (!::ResetEvent(socket_event_)) {
+        TRACE_GDB_REMOTE(
+            "Transport::ReadSomeData: Failed to reset socket event\n");
+      }
+      continue;
+    }
+
+    if (SocketGetLastError() != kErrInterrupt) {
+      return false;
+    }
+  }
+}
+
+void Transport::WaitForDebugStubEvent() {
+  // Don't wait if we already have data to read.
+  bool wait = !(pos_ < size_);
+
+  HANDLE handles[2];
+  handles[0] = faulted_thread_event_;
+  handles[1] = socket_event_;
+  int count = size_ < kBufSize ? 2 : 1;
+  int result =
+      WaitForMultipleObjects(count, handles, FALSE, wait ? INFINITE : 0);
+  if (result == WAIT_OBJECT_0 + 1) {
+    if (!ResetEvent(socket_event_)) {
+      TRACE_GDB_REMOTE(
+          "Transport::WaitForDebugStubEvent: Failed to reset socket event\n");
+    }
+    return;
+  } else if (result == WAIT_OBJECT_0) {
+    if (!ResetEvent(faulted_thread_event_)) {
+      TRACE_GDB_REMOTE(
+          "Transport::WaitForDebugStubEvent: Failed to reset event\n");
+    }
+    return;
+  } else if (result == WAIT_TIMEOUT) {
+    return;
+  }
+  TRACE_GDB_REMOTE(
+      "Transport::WaitForDebugStubEvent: Wait for events failed\n");
+}
+
+bool Transport::SignalThreadEvent() {
+  if (!SetEvent(faulted_thread_event_)) {
+    return false;
+  }
+  return true;
+}
+
+void Transport::Disconnect() {
+  TransportBase::Disconnect();
+
+  if (socket_event_ != WSA_INVALID_EVENT && !::WSACloseEvent(socket_event_)) {
+    TRACE_GDB_REMOTE("Transport::~Transport: Failed to close socket event\n");
+  }
+  socket_event_ = WSA_INVALID_EVENT;
+  SignalThreadEvent();
+}
+
+#else  // _WIN32
+
+Transport::Transport(SocketHandle s) : TransportBase(s) {
+  int fds[2];
+#if defined(__linux__)
+  int ret = pipe2(fds, O_CLOEXEC);
+#else
+  int ret = pipe(fds);
+#endif
+  if (ret < 0) {
+    TRACE_GDB_REMOTE(
+        "Transport::Transport: Failed to allocate pipe for faulted thread\n");
+  }
+  faulted_thread_fd_read_ = fds[0];
+  faulted_thread_fd_write_ = fds[1];
+}
+
+Transport::~Transport() {
+  if (close(faulted_thread_fd_read_) != 0) {
+    TRACE_GDB_REMOTE("Transport::~Transport: Failed to close event\n");
+  }
+  if (close(faulted_thread_fd_write_) != 0) {
+    TRACE_GDB_REMOTE("Transport::~Transport: Failed to close event\n");
+  }
+}
+
+bool Transport::AcceptConnection() {
+  CHECK(handle_accept_ == InvalidSocket);
+  handle_accept_ = ::accept(handle_bind_, NULL, 0);
+  if (handle_accept_ != InvalidSocket) {
+    DisableNagleAlgorithm(handle_accept_);
+    return true;
+  }
+  return false;
+}
+
+bool Transport::ReadSomeData() {
+  while (true) {
+    ssize_t result =
+        ::recv(handle_accept_, buf_.get() + size_, kBufSize - size_, 0);
+    if (result > 0) {
+      size_ += result;
+      return true;
+    }
+    if (result == 0) {
+      return false;  // The connection was gracefully closed.
+    }
+    if (SocketGetLastError() != kErrInterrupt) {
+      return false;
+    }
+  }
+}
+
+void Transport::WaitForDebugStubEvent() {
+  // Don't wait if we already have data to read.
+  bool wait = !(pos_ < size_);
+
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(faulted_thread_fd_read_, &fds);
+  int max_fd = faulted_thread_fd_read_;
+  if (size_ < kBufSize) {
+    FD_SET(handle_accept_, &fds);
+    max_fd = std::max(max_fd, handle_accept_);
+  }
+
+  int ret;
+  // We don't need sleep-polling on Linux now, so we set either zero or infinite
+  // timeout.
+  if (wait) {
+    ret = select(max_fd + 1, &fds, NULL, NULL, NULL);
+  } else {
+    struct timeval timeout;
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 0;
+    ret = select(max_fd + 1, &fds, NULL, NULL, &timeout);
+  }
+  if (ret < 0) {
+    TRACE_GDB_REMOTE(
+        "Transport::WaitForDebugStubEvent: Failed to wait for "
+        "debug stub event\n");
+  }
+
+  if (ret > 0) {
+    if (FD_ISSET(faulted_thread_fd_read_, &fds)) {
+      char buf[16];
+      if (read(faulted_thread_fd_read_, &buf, sizeof(buf)) < 0) {
+        TRACE_GDB_REMOTE(
+            "Transport::WaitForDebugStubEvent: Failed to read from "
+            "debug stub event pipe fd\n");
+      }
+    }
+    if (FD_ISSET(handle_accept_, &fds)) ReadSomeData();
+  }
+}
+
+bool Transport::SignalThreadEvent() {
+  // Notify the debug stub by marking the thread as faulted.
+  char buf = 0;
+  if (write(faulted_thread_fd_write_, &buf, sizeof(buf)) != sizeof(buf)) {
+    TRACE_GDB_REMOTE("SignalThreadEvent: Can't send debug stub event\n");
+    return false;
+  }
+  return true;
+}
+
+#endif  // _WIN32
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#undef SD_BOTH
diff --git a/deps/v8/src/debug/wasm/gdb-server/transport.h b/deps/v8/src/debug/wasm/gdb-server/transport.h
new file mode 100644
index 0000000000..077b1d1097
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/transport.h
@@ -0,0 +1,183 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_TRANSPORT_H_
+#define V8_DEBUG_WASM_GDB_SERVER_TRANSPORT_H_
+
+#include <sstream>
+#include <vector>
+#include "src/base/macros.h"
+#include "src/debug/wasm/gdb-server/util.h"
+
+#if _WIN32
+#include <windows.h>
+#include <winsock2.h>
+
+typedef SOCKET SocketHandle;
+
+#define CloseSocket closesocket
+#define InvalidSocket INVALID_SOCKET
+#define SocketGetLastError() WSAGetLastError()
+static const int kErrInterrupt = WSAEINTR;
+typedef int ssize_t;
+typedef int socklen_t;
+
+#else  // _WIN32
+
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/tcp.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <string>
+
+typedef int SocketHandle;
+
+#define CloseSocket close
+#define InvalidSocket (-1)
+#define SocketGetLastError() errno
+static const int kErrInterrupt = EINTR;
+
+#endif  // _WIN32
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+class Transport;
+
+// Acts as a factory for Transport objects bound to a specified TCP port.
+class SocketBinding {
+ public:
+  // Wrap existing socket handle.
+  explicit SocketBinding(SocketHandle socket_handle);
+
+  // Bind to the specified TCP port.
+  static SocketBinding Bind(uint16_t tcp_port);
+
+  bool IsValid() const { return socket_handle_ != InvalidSocket; }
+
+  // Create a transport object from this socket binding
+  std::unique_ptr<Transport> CreateTransport();
+
+  // Get port the socket is bound to.
+  uint16_t GetBoundPort();
+
+ private:
+  SocketHandle socket_handle_;
+};
+
+class TransportBase {
+ public:
+  explicit TransportBase(SocketHandle s);
+  virtual ~TransportBase();
+
+  // Read {len} bytes from this transport, possibly blocking until enough data
+  // is available.
+  // {dst} must point to a buffer large enough to contain {len} bytes.
+  // Returns true on success.
+  // Returns false if the connection is closed; in that case the {dst} may have
+  // been partially overwritten.
+  bool Read(char* dst, int32_t len);
+
+  // Write {len} bytes to this transport.
+  // Return true on success, false if the connection is closed.
+  bool Write(const char* src, int32_t len);
+
+  // Return true if there is data to read.
+  bool IsDataAvailable() const;
+
+  // Shuts down this transport, gracefully closing the existing connection and
+  // also closing the listening socket. This should be called when the GDB stub
+  // shuts down, when the program terminates.
+  void Close();
+
+  // If a socket connection with a debugger is present, gracefully closes it.
+  // This should be called when a debugging session gets closed.
+  virtual void Disconnect();
+
+ protected:
+  // Copy buffered data to *dst up to len bytes and update dst and len.
+  void CopyFromBuffer(char** dst, int32_t* len);
+
+  // Read available data from the socket. Return false on EOF or error.
+  virtual bool ReadSomeData() = 0;
+
+  static const int kBufSize = 4096;
+  std::unique_ptr<char[]> buf_;
+  int32_t pos_;
+  int32_t size_;
+  SocketHandle handle_bind_;
+  SocketHandle handle_accept_;
+};
+
+#if _WIN32
+
+class Transport : public TransportBase {
+ public:
+  explicit Transport(SocketHandle s);
+  ~Transport() override;
+
+  // Waits for an incoming connection on the bound port.
+  bool AcceptConnection();
+
+  // Blocks waiting for one of these two events to occur:
+  // - A network event (a new packet arrives, or the connection is dropped),
+  // - A thread event is signaled (the execution stopped because of a trap or
+  // breakpoint).
+  void WaitForDebugStubEvent();
+
+  // Signal that this transport should leave an alertable wait state because
+  // the execution of the debuggee was stopped because of a trap or breakpoint.
+  bool SignalThreadEvent();
+
+  void Disconnect() override;
+
+ private:
+  bool ReadSomeData() override;
+
+  HANDLE socket_event_;
+  HANDLE faulted_thread_event_;
+
+  DISALLOW_COPY_AND_ASSIGN(Transport);
+};
+
+#else  // _WIN32
+
+class Transport : public TransportBase {
+ public:
+  explicit Transport(SocketHandle s);
+  ~Transport() override;
+
+  // Waits for an incoming connection on the bound port.
+  bool AcceptConnection();
+
+  // Blocks waiting for one of these two events to occur:
+  // - A network event (a new packet arrives, or the connection is dropped),
+  // - The debuggee suspends execution because of a trap or breakpoint.
+  void WaitForDebugStubEvent();
+
+  // Signal that this transport should leave an alertable wait state because
+  // the execution of the debuggee was stopped because of a trap or breakpoint.
+  bool SignalThreadEvent();
+
+ private:
+  bool ReadSomeData() override;
+
+  int faulted_thread_fd_read_;
+  int faulted_thread_fd_write_;
+
+  DISALLOW_COPY_AND_ASSIGN(Transport);
+};
+
+#endif  // _WIN32
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_TRANSPORT_H_
diff --git a/deps/v8/src/debug/wasm/gdb-server/util.h b/deps/v8/src/debug/wasm/gdb-server/util.h
new file mode 100644
index 0000000000..5e977741d8
--- /dev/null
+++ b/deps/v8/src/debug/wasm/gdb-server/util.h
@@ -0,0 +1,27 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_DEBUG_WASM_GDB_SERVER_UTIL_H_
+#define V8_DEBUG_WASM_GDB_SERVER_UTIL_H_
+
+#include <string>
+#include "src/flags/flags.h"
+#include "src/utils/utils.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace gdb_server {
+
+#define TRACE_GDB_REMOTE(...)                                            \
+  do {                                                                   \
+    if (FLAG_trace_wasm_gdb_remote) PrintF("[gdb-remote] " __VA_ARGS__); \
+  } while (false)
+
+}  // namespace gdb_server
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_DEBUG_WASM_GDB_SERVER_UTIL_H_
diff --git a/deps/v8/src/deoptimizer/arm/deoptimizer-arm.cc b/deps/v8/src/deoptimizer/arm/deoptimizer-arm.cc
index becdc93a4c..c04e49282e 100644
--- a/deps/v8/src/deoptimizer/arm/deoptimizer-arm.cc
+++ b/deps/v8/src/deoptimizer/arm/deoptimizer-arm.cc
@@ -12,8 +12,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -262,6 +263,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/arm64/deoptimizer-arm64.cc b/deps/v8/src/deoptimizer/arm64/deoptimizer-arm64.cc
index 300e65ab00..9477fe185b 100644
--- a/deps/v8/src/deoptimizer/arm64/deoptimizer-arm64.cc
+++ b/deps/v8/src/deoptimizer/arm64/deoptimizer-arm64.cc
@@ -9,12 +9,18 @@
 #include "src/codegen/safepoint-table.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frame-constants.h"
+#include "src/execution/pointer-authentication.h"
 
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = true;
-const int Deoptimizer::kDeoptExitSize = kInstrSize;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = true;
+const int Deoptimizer::kNonLazyDeoptExitSize = kInstrSize;
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+const int Deoptimizer::kLazyDeoptExitSize = 2 * kInstrSize;
+#else
+const int Deoptimizer::kLazyDeoptExitSize = 1 * kInstrSize;
+#endif
 
 #define __ masm->
 
@@ -288,6 +294,9 @@ void Deoptimizer::GenerateDeoptimizationEntries(MacroAssembler* masm,
   __ Ldr(continuation, MemOperand(last_output_frame,
                                   FrameDescription::continuation_offset()));
   __ Ldr(lr, MemOperand(last_output_frame, FrameDescription::pc_offset()));
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  __ Autiasp();
+#endif
   __ Br(continuation);
 }
 
@@ -297,6 +306,14 @@ Float32 RegisterValues::GetFloatRegister(unsigned n) const {
 }
 
 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
+  // TODO(v8:10026): check that the pointer is still in the list of allowed
+  // builtins.
+  Address new_context =
+      static_cast<Address>(GetTop()) + offset + kPCOnStackSize;
+  uint64_t old_context = GetTop() + GetFrameSize();
+  PointerAuthentication::ReplaceContext(reinterpret_cast<Address*>(&value),
+                                        old_context, new_context);
+
   SetFrameSlot(offset, value);
 }
 
@@ -309,6 +326,12 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) {
+  // TODO(v8:10026): we should only accept a specific list of allowed builtins
+  // here.
+  pc_ = PointerAuthentication::SignPCWithSP(pc, GetTop());
+}
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/deoptimize-reason.h b/deps/v8/src/deoptimizer/deoptimize-reason.h
index cfb07248dc..4a23da8532 100644
--- a/deps/v8/src/deoptimizer/deoptimize-reason.h
+++ b/deps/v8/src/deoptimizer/deoptimize-reason.h
@@ -55,6 +55,7 @@ namespace internal {
   V(ValueMismatch, "value mismatch")                                           \
   V(WrongCallTarget, "wrong call target")                                      \
   V(WrongEnumIndices, "wrong enum indices")                                    \
+  V(WrongFeedbackCell, "wrong feedback cell")                                  \
   V(WrongInstanceType, "wrong instance type")                                  \
   V(WrongMap, "wrong map")                                                     \
   V(WrongName, "wrong name")                                                   \
diff --git a/deps/v8/src/deoptimizer/deoptimizer.cc b/deps/v8/src/deoptimizer/deoptimizer.cc
index 56431d4eea..9fcccd483c 100644
--- a/deps/v8/src/deoptimizer/deoptimizer.cc
+++ b/deps/v8/src/deoptimizer/deoptimizer.cc
@@ -14,6 +14,7 @@
 #include "src/codegen/register-configuration.h"
 #include "src/diagnostics/disasm.h"
 #include "src/execution/frames-inl.h"
+#include "src/execution/pointer-authentication.h"
 #include "src/execution/v8threads.h"
 #include "src/handles/global-handles.h"
 #include "src/heap/heap-inl.h"
@@ -122,7 +123,8 @@ class FrameWriter {
       PrintF(trace_scope_->file(), "    " V8PRIxPTR_FMT ": [top + %3d] <- ",
              output_address(output_offset), output_offset);
       if (obj.IsSmi()) {
-        PrintF(V8PRIxPTR_FMT " <Smi %d>", obj.ptr(), Smi::cast(obj).value());
+        PrintF(trace_scope_->file(), V8PRIxPTR_FMT " <Smi %d>", obj.ptr(),
+               Smi::cast(obj).value());
       } else {
         obj.ShortPrint(trace_scope_->file());
       }
@@ -252,7 +254,10 @@ class ActivationsFinder : public ThreadVisitor {
           int trampoline_pc = safepoint.trampoline_pc();
           DCHECK_IMPLIES(code == topmost_, safe_to_deopt_);
           // Replace the current pc on the stack with the trampoline.
-          it.frame()->set_pc(code.raw_instruction_start() + trampoline_pc);
+          // TODO(v8:10026): avoid replacing a signed pointer.
+          Address* pc_addr = it.frame()->pc_address();
+          Address new_pc = code.raw_instruction_start() + trampoline_pc;
+          PointerAuthentication::ReplacePC(pc_addr, new_pc, kSystemPointerSize);
         }
       }
     }
@@ -528,17 +533,37 @@ Deoptimizer::Deoptimizer(Isolate* isolate, JSFunction function,
       InternalFormalParameterCountWithReceiver(function.shared());
   input_ = new (size) FrameDescription(size, parameter_count);
 
-  if (kSupportsFixedDeoptExitSize) {
+  if (kSupportsFixedDeoptExitSizes) {
     DCHECK_EQ(bailout_id_, kMaxUInt32);
     // Calculate bailout id from return address.
-    DCHECK_GT(kDeoptExitSize, 0);
+    DCHECK_GT(kNonLazyDeoptExitSize, 0);
+    DCHECK_GT(kLazyDeoptExitSize, 0);
     DeoptimizationData deopt_data =
         DeoptimizationData::cast(compiled_code_.deoptimization_data());
     Address deopt_start = compiled_code_.raw_instruction_start() +
                           deopt_data.DeoptExitStart().value();
-    int offset = static_cast<int>(from_ - kDeoptExitSize - deopt_start);
-    DCHECK_EQ(0, offset % kDeoptExitSize);
-    bailout_id_ = offset / kDeoptExitSize;
+    int non_lazy_deopt_count = deopt_data.NonLazyDeoptCount().value();
+    Address lazy_deopt_start =
+        deopt_start + non_lazy_deopt_count * kNonLazyDeoptExitSize;
+    // The deoptimization exits are sorted so that lazy deopt exits appear last.
+    static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kEager,
+                  "lazy deopts are expected to be emitted last");
+    static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kSoft,
+                  "lazy deopts are expected to be emitted last");
+    // from_ is the value of the link register after the call to the
+    // deoptimizer, so for the last lazy deopt, from_ points to the first
+    // non-lazy deopt, so we use <=.
+    if (from_ <= lazy_deopt_start) {
+      int offset =
+          static_cast<int>(from_ - kNonLazyDeoptExitSize - deopt_start);
+      DCHECK_EQ(0, offset % kNonLazyDeoptExitSize);
+      bailout_id_ = offset / kNonLazyDeoptExitSize;
+    } else {
+      int offset =
+          static_cast<int>(from_ - kLazyDeoptExitSize - lazy_deopt_start);
+      DCHECK_EQ(0, offset % kLazyDeoptExitSize);
+      bailout_id_ = non_lazy_deopt_count + (offset / kLazyDeoptExitSize);
+    }
   }
 }
 
@@ -690,6 +715,13 @@ void Deoptimizer::DoComputeOutputFrames() {
     caller_fp_ = Memory<intptr_t>(fp_address);
     caller_pc_ =
         Memory<intptr_t>(fp_address + CommonFrameConstants::kCallerPCOffset);
+    // Sign caller_pc_ with caller_frame_top_ to be consistent with everything
+    // else here.
+    uint64_t sp = stack_fp_ + StandardFrameConstants::kCallerSPOffset;
+    // TODO(v8:10026): avoid replacing a signed pointer.
+    PointerAuthentication::ReplaceContext(
+        reinterpret_cast<Address*>(&caller_pc_), sp, caller_frame_top_);
+
     input_frame_context_ = Memory<intptr_t>(
         fp_address + CommonFrameConstants::kContextOrFrameTypeOffset);
 
@@ -1717,7 +1749,8 @@ void Deoptimizer::MaterializeHeapObjects() {
     Handle<Object> value = materialization.value_->GetValue();
 
     if (trace_scope_ != nullptr) {
-      PrintF("Materialization [" V8PRIxPTR_FMT "] <- " V8PRIxPTR_FMT " ;  ",
+      PrintF(trace_scope_->file(),
+             "Materialization [" V8PRIxPTR_FMT "] <- " V8PRIxPTR_FMT " ;  ",
              static_cast<intptr_t>(materialization.output_slot_address_),
              value->ptr());
       value->ShortPrint(trace_scope_->file());
@@ -3869,7 +3902,7 @@ TranslatedFrame* TranslatedState::GetArgumentsInfoFromJSFrameIndex(
         if (frames_[i].kind() ==
                 TranslatedFrame::kJavaScriptBuiltinContinuation &&
             frames_[i].shared_info()->internal_formal_parameter_count() ==
-                SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
+                kDontAdaptArgumentsSentinel) {
           DCHECK(frames_[i].shared_info()->IsApiFunction());
 
           // The argument count for this special case is always the second
diff --git a/deps/v8/src/deoptimizer/deoptimizer.h b/deps/v8/src/deoptimizer/deoptimizer.h
index beb2a9aa50..41ef7d2336 100644
--- a/deps/v8/src/deoptimizer/deoptimizer.h
+++ b/deps/v8/src/deoptimizer/deoptimizer.h
@@ -513,11 +513,12 @@ class Deoptimizer : public Malloced {
   // Set to true when the architecture supports deoptimization exit sequences
   // of a fixed size, that can be sorted so that the deoptimization index is
   // deduced from the address of the deoptimization exit.
-  static const bool kSupportsFixedDeoptExitSize;
+  static const bool kSupportsFixedDeoptExitSizes;
 
   // Size of deoptimization exit sequence. This is only meaningful when
-  // kSupportsFixedDeoptExitSize is true.
-  static const int kDeoptExitSize;
+  // kSupportsFixedDeoptExitSizes is true.
+  static const int kNonLazyDeoptExitSize;
+  static const int kLazyDeoptExitSize;
 
  private:
   friend class FrameWriter;
@@ -712,7 +713,7 @@ class FrameDescription {
   void SetTop(intptr_t top) { top_ = top; }
 
   intptr_t GetPc() const { return pc_; }
-  void SetPc(intptr_t pc) { pc_ = pc; }
+  void SetPc(intptr_t pc);
 
   intptr_t GetFp() const { return fp_; }
   void SetFp(intptr_t fp) { fp_ = fp; }
diff --git a/deps/v8/src/deoptimizer/ia32/deoptimizer-ia32.cc b/deps/v8/src/deoptimizer/ia32/deoptimizer-ia32.cc
index 2fd424a667..19be03c1e3 100644
--- a/deps/v8/src/deoptimizer/ia32/deoptimizer-ia32.cc
+++ b/deps/v8/src/deoptimizer/ia32/deoptimizer-ia32.cc
@@ -13,8 +13,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -217,6 +218,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/mips/deoptimizer-mips.cc b/deps/v8/src/deoptimizer/mips/deoptimizer-mips.cc
index bf82e2631b..80221c5cbe 100644
--- a/deps/v8/src/deoptimizer/mips/deoptimizer-mips.cc
+++ b/deps/v8/src/deoptimizer/mips/deoptimizer-mips.cc
@@ -10,8 +10,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -236,6 +237,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/mips64/deoptimizer-mips64.cc b/deps/v8/src/deoptimizer/mips64/deoptimizer-mips64.cc
index a1138d202f..3b8b1b9659 100644
--- a/deps/v8/src/deoptimizer/mips64/deoptimizer-mips64.cc
+++ b/deps/v8/src/deoptimizer/mips64/deoptimizer-mips64.cc
@@ -10,8 +10,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -236,6 +237,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/ppc/deoptimizer-ppc.cc b/deps/v8/src/deoptimizer/ppc/deoptimizer-ppc.cc
index 1d05968806..0a8798dcc8 100644
--- a/deps/v8/src/deoptimizer/ppc/deoptimizer-ppc.cc
+++ b/deps/v8/src/deoptimizer/ppc/deoptimizer-ppc.cc
@@ -11,8 +11,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -258,6 +259,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   SetFrameSlot(offset, value);
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/deoptimizer/s390/deoptimizer-s390.cc b/deps/v8/src/deoptimizer/s390/deoptimizer-s390.cc
index 63ea22f71a..66d9d0db8e 100644
--- a/deps/v8/src/deoptimizer/s390/deoptimizer-s390.cc
+++ b/deps/v8/src/deoptimizer/s390/deoptimizer-s390.cc
@@ -10,8 +10,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -254,6 +255,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/deoptimizer/x64/deoptimizer-x64.cc b/deps/v8/src/deoptimizer/x64/deoptimizer-x64.cc
index 724062c506..ea13361341 100644
--- a/deps/v8/src/deoptimizer/x64/deoptimizer-x64.cc
+++ b/deps/v8/src/deoptimizer/x64/deoptimizer-x64.cc
@@ -13,8 +13,9 @@
 namespace v8 {
 namespace internal {
 
-const bool Deoptimizer::kSupportsFixedDeoptExitSize = false;
-const int Deoptimizer::kDeoptExitSize = 0;
+const bool Deoptimizer::kSupportsFixedDeoptExitSizes = false;
+const int Deoptimizer::kNonLazyDeoptExitSize = 0;
+const int Deoptimizer::kLazyDeoptExitSize = 0;
 
 #define __ masm->
 
@@ -221,18 +222,10 @@ Float32 RegisterValues::GetFloatRegister(unsigned n) const {
 }
 
 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
-  if (kPCOnStackSize == 2 * kSystemPointerSize) {
-    // Zero out the high-32 bit of PC for x32 port.
-    SetFrameSlot(offset + kSystemPointerSize, 0);
-  }
   SetFrameSlot(offset, value);
 }
 
 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
-  if (kFPOnStackSize == 2 * kSystemPointerSize) {
-    // Zero out the high-32 bit of FP for x32 port.
-    SetFrameSlot(offset + kSystemPointerSize, 0);
-  }
   SetFrameSlot(offset, value);
 }
 
@@ -241,6 +234,8 @@ void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
   UNREACHABLE();
 }
 
+void FrameDescription::SetPc(intptr_t pc) { pc_ = pc; }
+
 #undef __
 
 }  // namespace internal
diff --git a/deps/v8/src/diagnostics/arm64/disasm-arm64.cc b/deps/v8/src/diagnostics/arm64/disasm-arm64.cc
index 5a87f73529..c2a82a5837 100644
--- a/deps/v8/src/diagnostics/arm64/disasm-arm64.cc
+++ b/deps/v8/src/diagnostics/arm64/disasm-arm64.cc
@@ -1436,7 +1436,7 @@ void DisassemblingDecoder::VisitSystem(Instruction* instr) {
 #define PAUTH_CASE(NAME, MN) \
   case NAME:                 \
     mnemonic = MN;           \
-    form = NULL;             \
+    form = nullptr;          \
     break;
 
       PAUTH_SYSTEM_MNEMONICS(PAUTH_CASE)
@@ -1478,17 +1478,30 @@ void DisassemblingDecoder::VisitSystem(Instruction* instr) {
     }
   } else if (instr->Mask(SystemHintFMask) == SystemHintFixed) {
     DCHECK(instr->Mask(SystemHintMask) == HINT);
+    form = nullptr;
     switch (instr->ImmHint()) {
-      case NOP: {
+      case NOP:
         mnemonic = "nop";
-        form = nullptr;
         break;
-      }
-      case CSDB: {
+      case CSDB:
         mnemonic = "csdb";
-        form = nullptr;
         break;
-      }
+      case BTI:
+        mnemonic = "bti";
+        break;
+      case BTI_c:
+        mnemonic = "bti c";
+        break;
+      case BTI_j:
+        mnemonic = "bti j";
+        break;
+      case BTI_jc:
+        mnemonic = "bti jc";
+        break;
+      default:
+        // Fall back to 'hint #<imm7>'.
+        form = "'IH";
+        mnemonic = "hint";
     }
   } else if (instr->Mask(MemBarrierFMask) == MemBarrierFixed) {
     switch (instr->Mask(MemBarrierMask)) {
diff --git a/deps/v8/src/diagnostics/code-tracer.h b/deps/v8/src/diagnostics/code-tracer.h
index 6dd8d3e086..a9f276bf44 100644
--- a/deps/v8/src/diagnostics/code-tracer.h
+++ b/deps/v8/src/diagnostics/code-tracer.h
@@ -52,6 +52,9 @@ class CodeTracer final : public Malloced {
 
     if (file_ == nullptr) {
       file_ = base::OS::FOpen(filename_.begin(), "ab");
+      CHECK_WITH_MSG(file_ != nullptr,
+                     "could not open file. If on Android, try passing "
+                     "--redirect-code-traces-to=/sdcard/Download/<file-name>");
     }
 
     scope_depth_++;
@@ -63,6 +66,7 @@ class CodeTracer final : public Malloced {
     }
 
     if (--scope_depth_ == 0) {
+      DCHECK_NOT_NULL(file_);
       fclose(file_);
       file_ = nullptr;
     }
diff --git a/deps/v8/src/diagnostics/ia32/disasm-ia32.cc b/deps/v8/src/diagnostics/ia32/disasm-ia32.cc
index 0cb36d1228..129c2d72e1 100644
--- a/deps/v8/src/diagnostics/ia32/disasm-ia32.cc
+++ b/deps/v8/src/diagnostics/ia32/disasm-ia32.cc
@@ -781,6 +781,7 @@ int DisassemblerIA32::AVXInstruction(byte* data) {
     break;                                                                     \
   }
 
+        SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSE_AVX_RM_DIS_CASE)
         SSE4_RM_INSTRUCTION_LIST(DECLARE_SSE_AVX_RM_DIS_CASE)
 #undef DECLARE_SSE_AVX_RM_DIS_CASE
       default:
@@ -2100,6 +2101,7 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
   }
 
               SSSE3_INSTRUCTION_LIST(SSE34_DIS_CASE)
+              SSSE3_UNOP_INSTRUCTION_LIST(SSE34_DIS_CASE)
               SSE4_INSTRUCTION_LIST(SSE34_DIS_CASE)
               SSE4_RM_INSTRUCTION_LIST(SSE34_DIS_CASE)
 #undef SSE34_DIS_CASE
diff --git a/deps/v8/src/diagnostics/objects-debug.cc b/deps/v8/src/diagnostics/objects-debug.cc
index d087a6d21d..4a9d029a05 100644
--- a/deps/v8/src/diagnostics/objects-debug.cc
+++ b/deps/v8/src/diagnostics/objects-debug.cc
@@ -32,6 +32,7 @@
 #include "src/objects/js-array-inl.h"
 #include "src/objects/layout-descriptor.h"
 #include "src/objects/objects-inl.h"
+#include "src/roots/roots.h"
 #ifdef V8_INTL_SUPPORT
 #include "src/objects/js-break-iterator-inl.h"
 #include "src/objects/js-collator-inl.h"
@@ -138,6 +139,10 @@ void Smi::SmiVerify(Isolate* isolate) {
   CHECK(!IsConstructor());
 }
 
+void TaggedIndex::TaggedIndexVerify(Isolate* isolate) {
+  CHECK(IsTaggedIndex());
+}
+
 void HeapObject::HeapObjectVerify(Isolate* isolate) {
   TorqueGeneratedClassVerifiers::HeapObjectVerify(*this, isolate);
 
@@ -242,6 +247,7 @@ void HeapObject::HeapObjectVerify(Isolate* isolate) {
       // Every class that has its fields defined in a .tq file and corresponds
       // to exactly one InstanceType value is included in the following list.
       TORQUE_INSTANCE_CHECKERS_SINGLE_FULLY_DEFINED(MAKE_TORQUE_CASE)
+      TORQUE_INSTANCE_CHECKERS_MULTIPLE_FULLY_DEFINED(MAKE_TORQUE_CASE)
 #undef MAKE_TORQUE_CASE
 
     case ALLOCATION_SITE_TYPE:
@@ -812,12 +818,20 @@ void JSFunction::JSFunctionVerify(Isolate* isolate) {
 }
 
 void SharedFunctionInfo::SharedFunctionInfoVerify(Isolate* isolate) {
+  // TODO(leszeks): Add a TorqueGeneratedClassVerifier for OffThreadIsolate.
   TorqueGeneratedClassVerifiers::SharedFunctionInfoVerify(*this, isolate);
+  this->SharedFunctionInfoVerify(ReadOnlyRoots(isolate));
+}
+
+void SharedFunctionInfo::SharedFunctionInfoVerify(OffThreadIsolate* isolate) {
+  this->SharedFunctionInfoVerify(ReadOnlyRoots(isolate));
+}
 
+void SharedFunctionInfo::SharedFunctionInfoVerify(ReadOnlyRoots roots) {
   Object value = name_or_scope_info();
   if (value.IsScopeInfo()) {
     CHECK_LT(0, ScopeInfo::cast(value).length());
-    CHECK_NE(value, ReadOnlyRoots(isolate).empty_scope_info());
+    CHECK_NE(value, roots.empty_scope_info());
   }
 
   CHECK(HasWasmExportedFunctionData() || IsApiFunction() ||
@@ -826,13 +840,13 @@ void SharedFunctionInfo::SharedFunctionInfoVerify(Isolate* isolate) {
         HasUncompiledDataWithoutPreparseData() || HasWasmJSFunctionData() ||
         HasWasmCapiFunctionData());
 
-  CHECK(script_or_debug_info().IsUndefined(isolate) ||
+  CHECK(script_or_debug_info().IsUndefined(roots) ||
         script_or_debug_info().IsScript() || HasDebugInfo());
 
   if (!is_compiled()) {
     CHECK(!HasFeedbackMetadata());
     CHECK(outer_scope_info().IsScopeInfo() ||
-          outer_scope_info().IsTheHole(isolate));
+          outer_scope_info().IsTheHole(roots));
   } else if (HasBytecodeArray() && HasFeedbackMetadata()) {
     CHECK(feedback_metadata().IsFeedbackMetadata());
   }
@@ -1057,8 +1071,8 @@ void WeakCell::WeakCellVerify(Isolate* isolate) {
 
   CHECK(key_list_next().IsWeakCell() || key_list_next().IsUndefined(isolate));
 
-  CHECK(finalization_group().IsUndefined(isolate) ||
-        finalization_group().IsJSFinalizationGroup());
+  CHECK(finalization_registry().IsUndefined(isolate) ||
+        finalization_registry().IsJSFinalizationRegistry());
 }
 
 void JSWeakRef::JSWeakRefVerify(Isolate* isolate) {
@@ -1067,8 +1081,8 @@ void JSWeakRef::JSWeakRefVerify(Isolate* isolate) {
   CHECK(target().IsUndefined(isolate) || target().IsJSReceiver());
 }
 
-void JSFinalizationGroup::JSFinalizationGroupVerify(Isolate* isolate) {
-  CHECK(IsJSFinalizationGroup());
+void JSFinalizationRegistry::JSFinalizationRegistryVerify(Isolate* isolate) {
+  CHECK(IsJSFinalizationRegistry());
   JSObjectVerify(isolate);
   VerifyHeapPointer(isolate, cleanup());
   CHECK(active_cells().IsUndefined(isolate) || active_cells().IsWeakCell());
@@ -1079,14 +1093,15 @@ void JSFinalizationGroup::JSFinalizationGroupVerify(Isolate* isolate) {
   if (cleared_cells().IsWeakCell()) {
     CHECK(WeakCell::cast(cleared_cells()).prev().IsUndefined(isolate));
   }
-  CHECK(next().IsUndefined(isolate) || next().IsJSFinalizationGroup());
+  CHECK(next_dirty().IsUndefined(isolate) ||
+        next_dirty().IsJSFinalizationRegistry());
 }
 
-void JSFinalizationGroupCleanupIterator::
-    JSFinalizationGroupCleanupIteratorVerify(Isolate* isolate) {
-  CHECK(IsJSFinalizationGroupCleanupIterator());
+void JSFinalizationRegistryCleanupIterator::
+    JSFinalizationRegistryCleanupIteratorVerify(Isolate* isolate) {
+  CHECK(IsJSFinalizationRegistryCleanupIterator());
   JSObjectVerify(isolate);
-  VerifyHeapPointer(isolate, finalization_group());
+  VerifyHeapPointer(isolate, finalization_registry());
 }
 
 void JSWeakMap::JSWeakMapVerify(Isolate* isolate) {
diff --git a/deps/v8/src/diagnostics/objects-printer.cc b/deps/v8/src/diagnostics/objects-printer.cc
index 9dae2881b9..e36171edfd 100644
--- a/deps/v8/src/diagnostics/objects-printer.cc
+++ b/deps/v8/src/diagnostics/objects-printer.cc
@@ -207,6 +207,7 @@ void HeapObject::HeapObjectPrint(std::ostream& os) {  // NOLINT
       // Every class that has its fields defined in a .tq file and corresponds
       // to exactly one InstanceType value is included in the following list.
       TORQUE_INSTANCE_CHECKERS_SINGLE_FULLY_DEFINED(MAKE_TORQUE_CASE)
+      TORQUE_INSTANCE_CHECKERS_MULTIPLE_FULLY_DEFINED(MAKE_TORQUE_CASE)
 #undef MAKE_TORQUE_CASE
 
     case ALLOCATION_SITE_TYPE:
@@ -1150,7 +1151,7 @@ void JSMapIterator::JSMapIteratorPrint(std::ostream& os) {  // NOLINT
 
 void WeakCell::WeakCellPrint(std::ostream& os) {
   PrintHeader(os, "WeakCell");
-  os << "\n - finalization_group: " << Brief(finalization_group());
+  os << "\n - finalization_registry: " << Brief(finalization_registry());
   os << "\n - target: " << Brief(target());
   os << "\n - holdings: " << Brief(holdings());
   os << "\n - prev: " << Brief(prev());
@@ -1166,8 +1167,8 @@ void JSWeakRef::JSWeakRefPrint(std::ostream& os) {
   JSObjectPrintBody(os, *this);
 }
 
-void JSFinalizationGroup::JSFinalizationGroupPrint(std::ostream& os) {
-  JSObjectPrintHeader(os, *this, "JSFinalizationGroup");
+void JSFinalizationRegistry::JSFinalizationRegistryPrint(std::ostream& os) {
+  JSObjectPrintHeader(os, *this, "JSFinalizationRegistry");
   os << "\n - native_context: " << Brief(native_context());
   os << "\n - cleanup: " << Brief(cleanup());
   os << "\n - active_cells: " << Brief(active_cells());
@@ -1186,10 +1187,10 @@ void JSFinalizationGroup::JSFinalizationGroupPrint(std::ostream& os) {
   JSObjectPrintBody(os, *this);
 }
 
-void JSFinalizationGroupCleanupIterator::
-    JSFinalizationGroupCleanupIteratorPrint(std::ostream& os) {
-  JSObjectPrintHeader(os, *this, "JSFinalizationGroupCleanupIterator");
-  os << "\n - finalization_group: " << Brief(finalization_group());
+void JSFinalizationRegistryCleanupIterator::
+    JSFinalizationRegistryCleanupIteratorPrint(std::ostream& os) {
+  JSObjectPrintHeader(os, *this, "JSFinalizationRegistryCleanupIterator");
+  os << "\n - finalization_registry: " << Brief(finalization_registry());
   JSObjectPrintBody(os, *this);
 }
 
@@ -1306,12 +1307,12 @@ void JSFunction::JSFunctionPrint(std::ostream& os) {  // NOLINT
   }
   if (WasmExportedFunction::IsWasmExportedFunction(*this)) {
     WasmExportedFunction function = WasmExportedFunction::cast(*this);
-    os << "\n - WASM instance: " << Brief(function.instance());
-    os << "\n - WASM function index: " << function.function_index();
+    os << "\n - Wasm instance: " << Brief(function.instance());
+    os << "\n - Wasm function index: " << function.function_index();
   }
   if (WasmJSFunction::IsWasmJSFunction(*this)) {
     WasmJSFunction function = WasmJSFunction::cast(*this);
-    os << "\n - WASM wrapper around: " << Brief(function.GetCallable());
+    os << "\n - Wasm wrapper around: " << Brief(function.GetCallable());
   }
   shared().PrintSourceCode(os);
   JSObjectPrintBody(os, *this);
@@ -1364,6 +1365,12 @@ void SharedFunctionInfo::SharedFunctionInfoPrint(std::ostream& os) {  // NOLINT
   if (HasInferredName()) {
     os << "\n - inferred name: " << Brief(inferred_name());
   }
+  if (class_scope_has_private_brand()) {
+    os << "\n - class_scope_has_private_brand";
+  }
+  if (has_static_private_methods_or_accessors()) {
+    os << "\n - has_static_private_methods_or_accessors";
+  }
   os << "\n - kind: " << kind();
   os << "\n - syntax kind: " << syntax_kind();
   if (needs_home_object()) {
@@ -1779,7 +1786,7 @@ void WasmGlobalObject::WasmGlobalObjectPrint(std::ostream& os) {  // NOLINT
   os << "\n - tagged_buffer: " << Brief(tagged_buffer());
   os << "\n - offset: " << offset();
   os << "\n - flags: " << flags();
-  os << "\n - type: " << type();
+  os << "\n - type: " << type().kind();
   os << "\n - is_mutable: " << is_mutable();
   os << "\n";
 }
@@ -1986,15 +1993,18 @@ void Script::ScriptPrint(std::ostream& os) {  // NOLINT
   os << "\n - context data: " << Brief(context_data());
   os << "\n - compilation type: " << compilation_type();
   os << "\n - line ends: " << Brief(line_ends());
-  if (has_eval_from_shared()) {
-    os << "\n - eval from shared: " << Brief(eval_from_shared());
-  }
-  if (is_wrapped()) {
-    os << "\n - wrapped arguments: " << Brief(wrapped_arguments());
-  }
-  os << "\n - eval from position: " << eval_from_position();
-  if (has_wasm_breakpoint_infos()) {
-    os << "\n - wasm_breakpoint_infos: " << Brief(wasm_breakpoint_infos());
+  if (type() == TYPE_WASM) {
+    if (has_wasm_breakpoint_infos()) {
+      os << "\n - wasm_breakpoint_infos: " << Brief(wasm_breakpoint_infos());
+    }
+  } else {
+    if (has_eval_from_shared()) {
+      os << "\n - eval from shared: " << Brief(eval_from_shared());
+    }
+    if (is_wrapped()) {
+      os << "\n - wrapped arguments: " << Brief(wrapped_arguments());
+    }
+    os << "\n - eval from position: " << eval_from_position();
   }
   os << "\n - shared function infos: " << Brief(shared_function_infos());
   os << "\n";
@@ -2004,7 +2014,6 @@ void Script::ScriptPrint(std::ostream& os) {  // NOLINT
 void JSV8BreakIterator::JSV8BreakIteratorPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, *this, "JSV8BreakIterator");
   os << "\n - locale: " << Brief(locale());
-  os << "\n - type: " << TypeAsString();
   os << "\n - break iterator: " << Brief(break_iterator());
   os << "\n - unicode string: " << Brief(unicode_string());
   os << "\n - bound adopt text: " << Brief(bound_adopt_text());
@@ -2059,7 +2068,6 @@ void JSLocale::JSLocalePrint(std::ostream& os) {  // NOLINT
 void JSNumberFormat::JSNumberFormatPrint(std::ostream& os) {  // NOLINT
   JSObjectPrintHeader(os, *this, "JSNumberFormat");
   os << "\n - locale: " << Brief(locale());
-  os << "\n - numberingSystem: " << Brief(numberingSystem());
   os << "\n - icu_number_formatter: " << Brief(icu_number_formatter());
   os << "\n - bound_format: " << Brief(bound_format());
   JSObjectPrintBody(os, *this);
@@ -2079,7 +2087,6 @@ void JSRelativeTimeFormat::JSRelativeTimeFormatPrint(
   JSObjectPrintHeader(os, *this, "JSRelativeTimeFormat");
   os << "\n - locale: " << Brief(locale());
   os << "\n - numberingSystem: " << Brief(numberingSystem());
-  os << "\n - style: " << StyleAsString();
   os << "\n - numeric: " << NumericAsString();
   os << "\n - icu formatter: " << Brief(icu_formatter());
   os << "\n";
diff --git a/deps/v8/src/diagnostics/perf-jit.h b/deps/v8/src/diagnostics/perf-jit.h
index 2192063508..dbe78ddf2d 100644
--- a/deps/v8/src/diagnostics/perf-jit.h
+++ b/deps/v8/src/diagnostics/perf-jit.h
@@ -81,7 +81,8 @@ class PerfJitLogger : public CodeEventLogger {
   static const uint32_t kElfMachIA32 = 3;
   static const uint32_t kElfMachX64 = 62;
   static const uint32_t kElfMachARM = 40;
-  static const uint32_t kElfMachMIPS = 10;
+  static const uint32_t kElfMachMIPS = 8;
+  static const uint32_t kElfMachMIPS64 = 8;
   static const uint32_t kElfMachARM64 = 183;
   static const uint32_t kElfMachS390x = 22;
   static const uint32_t kElfMachPPC64 = 21;
@@ -95,6 +96,8 @@ class PerfJitLogger : public CodeEventLogger {
     return kElfMachARM;
 #elif V8_TARGET_ARCH_MIPS
     return kElfMachMIPS;
+#elif V8_TARGET_ARCH_MIPS64
+    return kElfMachMIPS64;
 #elif V8_TARGET_ARCH_ARM64
     return kElfMachARM64;
 #elif V8_TARGET_ARCH_S390X
diff --git a/deps/v8/src/diagnostics/ppc/disasm-ppc.cc b/deps/v8/src/diagnostics/ppc/disasm-ppc.cc
index e7d26858e5..99767f17dc 100644
--- a/deps/v8/src/diagnostics/ppc/disasm-ppc.cc
+++ b/deps/v8/src/diagnostics/ppc/disasm-ppc.cc
@@ -27,7 +27,7 @@
 #include <stdio.h>
 #include <string.h>
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/base/platform/platform.h"
 #include "src/codegen/macro-assembler.h"
@@ -1519,4 +1519,4 @@ void Disassembler::Disassemble(FILE* f, byte* begin, byte* end,
 
 }  // namespace disasm
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/diagnostics/unwinder.cc b/deps/v8/src/diagnostics/unwinder.cc
index 64adf17b82..c08fe20330 100644
--- a/deps/v8/src/diagnostics/unwinder.cc
+++ b/deps/v8/src/diagnostics/unwinder.cc
@@ -7,6 +7,7 @@
 #include "include/v8.h"
 #include "src/common/globals.h"
 #include "src/execution/frame-constants.h"
+#include "src/execution/pointer-authentication.h"
 
 namespace v8 {
 
@@ -87,8 +88,9 @@ void* GetReturnAddressFromFP(void* fp, void* pc,
     caller_pc_offset = i::EntryFrameConstants::kDirectCallerPCOffset;
   }
 #endif
-  return reinterpret_cast<void*>(
-      Load(reinterpret_cast<i::Address>(fp) + caller_pc_offset));
+  i::Address ret_addr =
+      Load(reinterpret_cast<i::Address>(fp) + caller_pc_offset);
+  return reinterpret_cast<void*>(i::PointerAuthentication::StripPAC(ret_addr));
 }
 
 void* GetReturnAddressFromFP(void* fp, void* pc,
@@ -99,8 +101,9 @@ void* GetReturnAddressFromFP(void* fp, void* pc,
     caller_pc_offset = i::EntryFrameConstants::kDirectCallerPCOffset;
   }
 #endif
-  return reinterpret_cast<void*>(
-      Load(reinterpret_cast<i::Address>(fp) + caller_pc_offset));
+  i::Address ret_addr =
+      Load(reinterpret_cast<i::Address>(fp) + caller_pc_offset);
+  return reinterpret_cast<void*>(i::PointerAuthentication::StripPAC(ret_addr));
 }
 
 void* GetCallerFPFromFP(void* fp, void* pc,
diff --git a/deps/v8/src/diagnostics/unwinding-info-win64.cc b/deps/v8/src/diagnostics/unwinding-info-win64.cc
index cd1b976c18..f3b9a753af 100644
--- a/deps/v8/src/diagnostics/unwinding-info-win64.cc
+++ b/deps/v8/src/diagnostics/unwinding-info-win64.cc
@@ -16,37 +16,6 @@
 #error "Unsupported OS"
 #endif  // V8_OS_WIN_X64
 
-// Forward declaration to keep this independent of Win8
-NTSYSAPI
-DWORD
-NTAPI
-RtlAddGrowableFunctionTable(
-    _Out_ PVOID* DynamicTable,
-    _In_reads_(MaximumEntryCount) PRUNTIME_FUNCTION FunctionTable,
-    _In_ DWORD EntryCount,
-    _In_ DWORD MaximumEntryCount,
-    _In_ ULONG_PTR RangeBase,
-    _In_ ULONG_PTR RangeEnd
-    );
-
-
-NTSYSAPI
-void
-NTAPI
-RtlGrowFunctionTable(
-    _Inout_ PVOID DynamicTable,
-    _In_ DWORD NewEntryCount
-    );
-
-
-NTSYSAPI
-void
-NTAPI
-RtlDeleteGrowableFunctionTable(
-    _In_ PVOID DynamicTable
-    );
-
-
 namespace v8 {
 namespace internal {
 namespace win64_unwindinfo {
@@ -548,7 +517,7 @@ void RegisterNonABICompliantCodeRange(void* start, size_t size_in_bytes) {
 
   // When the --win64-unwinding-info flag is set, we call
   // RtlAddGrowableFunctionTable to register unwinding info for the whole code
-  // range of an isolate or WASM module. This enables the Windows OS stack
+  // range of an isolate or Wasm module. This enables the Windows OS stack
   // unwinder to work correctly with V8-generated code, enabling stack walking
   // in Windows debuggers and performance tools. However, the
   // RtlAddGrowableFunctionTable API is only supported on Windows 8 and above.
diff --git a/deps/v8/src/diagnostics/unwinding-info-win64.h b/deps/v8/src/diagnostics/unwinding-info-win64.h
index 102df15590..ca66437e00 100644
--- a/deps/v8/src/diagnostics/unwinding-info-win64.h
+++ b/deps/v8/src/diagnostics/unwinding-info-win64.h
@@ -32,7 +32,7 @@ bool CanEmitUnwindInfoForBuiltins();
 
 /**
  * Returns true if V8 if we can register unwinding data for the whole code range
- * of an isolate or WASM module. The first page of the code range is reserved
+ * of an isolate or Wasm module. The first page of the code range is reserved
  * and writable, to be used to store unwind data, as documented in:
  * https://docs.microsoft.com/en-us/cpp/build/exception-handling-x64.
  * In jitless mode V8 does not allocate any executable memory itself so the only
@@ -52,9 +52,9 @@ void UnregisterNonABICompliantCodeRange(void* start);
 /**
  * Default count of RUNTIME_FUNCTION needed. For Windows X64, 1 RUNTIME_FUNCTION
  * covers 4GB range which is sufficient to cover the whole code range of an
- * isolate or WASM module. For Windows ARM64, 1 RUNTIME_FUNCTION covers
+ * isolate or Wasm module. For Windows ARM64, 1 RUNTIME_FUNCTION covers
  * kMaxFunctionLength bytes so multiple RUNTIME_FUNCTION structs could be needed
- * to cover the whole code range of an isolate or WASM module. The extra
+ * to cover the whole code range of an isolate or Wasm module. The extra
  * RUNTIME_FUNCTIONs are assumed following the first one in the reserved page.
  */
 static const uint32_t kDefaultRuntimeFunctionCount = 1;
diff --git a/deps/v8/src/diagnostics/x64/disasm-x64.cc b/deps/v8/src/diagnostics/x64/disasm-x64.cc
index a1331784a3..d603e6169c 100644
--- a/deps/v8/src/diagnostics/x64/disasm-x64.cc
+++ b/deps/v8/src/diagnostics/x64/disasm-x64.cc
@@ -929,15 +929,16 @@ int DisassemblerX64::AVXInstruction(byte* data) {
         SSE4_2_INSTRUCTION_LIST(DECLARE_SSE_AVX_DIS_CASE)
 #undef DECLARE_SSE_AVX_DIS_CASE
 
-#define DECLARE_SSE_PMOV_AVX_DIS_CASE(instruction, notUsed1, notUsed2, \
+#define DECLARE_SSE_UNOP_AVX_DIS_CASE(instruction, notUsed1, notUsed2, \
                                       notUsed3, opcode)                \
   case 0x##opcode: {                                                   \
     AppendToBuffer("v" #instruction " %s,", NameOfXMMRegister(regop)); \
     current += PrintRightXMMOperand(current);                          \
     break;                                                             \
   }
-        SSE4_PMOV_INSTRUCTION_LIST(DECLARE_SSE_PMOV_AVX_DIS_CASE)
-#undef DECLARE_SSE_PMOV_AVX_DIS_CASE
+        SSSE3_UNOP_INSTRUCTION_LIST(DECLARE_SSE_UNOP_AVX_DIS_CASE)
+        SSE4_UNOP_INSTRUCTION_LIST(DECLARE_SSE_UNOP_AVX_DIS_CASE)
+#undef DECLARE_SSE_UNOP_AVX_DIS_CASE
 
       default:
         UnimplementedInstruction();
@@ -1067,6 +1068,10 @@ int DisassemblerX64::AVXInstruction(byte* data) {
                        NameOfXMMRegister(vvvv));
         current += PrintRightXMMOperand(current);
         break;
+      case 0x5B:
+        AppendToBuffer("vcvttps2dq %s,", NameOfXMMRegister(regop));
+        current += PrintRightXMMOperand(current);
+        break;
       case 0x5C:
         AppendToBuffer("vsubss %s,%s,", NameOfXMMRegister(regop),
                        NameOfXMMRegister(vvvv));
@@ -1091,6 +1096,11 @@ int DisassemblerX64::AVXInstruction(byte* data) {
         AppendToBuffer("vmovdqu %s,", NameOfXMMRegister(regop));
         current += PrintRightXMMOperand(current);
         break;
+      case 0x70:
+        AppendToBuffer("vpshufhw %s,", NameOfXMMRegister(regop));
+        current += PrintRightXMMOperand(current);
+        AppendToBuffer(",0x%x", *current++);
+        break;
       case 0x7F:
         AppendToBuffer("vmovdqu ");
         current += PrintRightXMMOperand(current);
@@ -1426,21 +1436,6 @@ int DisassemblerX64::AVXInstruction(byte* data) {
         AppendToBuffer("vmovmskpd %s,", NameOfCPURegister(regop));
         current += PrintRightXMMOperand(current);
         break;
-      case 0x54:
-        AppendToBuffer("vandpd %s,%s,", NameOfXMMRegister(regop),
-                       NameOfXMMRegister(vvvv));
-        current += PrintRightXMMOperand(current);
-        break;
-      case 0x56:
-        AppendToBuffer("vorpd %s,%s,", NameOfXMMRegister(regop),
-                       NameOfXMMRegister(vvvv));
-        current += PrintRightXMMOperand(current);
-        break;
-      case 0x57:
-        AppendToBuffer("vxorpd %s,%s,", NameOfXMMRegister(regop),
-                       NameOfXMMRegister(vvvv));
-        current += PrintRightXMMOperand(current);
-        break;
       case 0x6E:
         AppendToBuffer("vmov%c %s,", vex_w() ? 'q' : 'd',
                        NameOfXMMRegister(regop));
@@ -1505,6 +1500,15 @@ int DisassemblerX64::AVXInstruction(byte* data) {
 
         SSE2_INSTRUCTION_LIST(DECLARE_SSE_AVX_DIS_CASE)
 #undef DECLARE_SSE_AVX_DIS_CASE
+#define DECLARE_SSE_UNOP_AVX_DIS_CASE(instruction, notUsed1, notUsed2, opcode) \
+  case 0x##opcode: {                                                           \
+    AppendToBuffer("v" #instruction " %s,", NameOfXMMRegister(regop));         \
+    current += PrintRightXMMOperand(current);                                  \
+    break;                                                                     \
+  }
+
+        SSE2_UNOP_INSTRUCTION_LIST(DECLARE_SSE_UNOP_AVX_DIS_CASE)
+#undef DECLARE_SSE_UNOP_AVX_DIS_CASE
       default:
         UnimplementedInstruction();
     }
@@ -1815,8 +1819,9 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
   }
 
         SSSE3_INSTRUCTION_LIST(SSE34_DIS_CASE)
+        SSSE3_UNOP_INSTRUCTION_LIST(SSE34_DIS_CASE)
         SSE4_INSTRUCTION_LIST(SSE34_DIS_CASE)
-        SSE4_PMOV_INSTRUCTION_LIST(SSE34_DIS_CASE)
+        SSE4_UNOP_INSTRUCTION_LIST(SSE34_DIS_CASE)
         SSE4_2_INSTRUCTION_LIST(SSE34_DIS_CASE)
 #undef SSE34_DIS_CASE
         default:
@@ -2049,7 +2054,7 @@ int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
         } else if (opcode == 0xD2) {
           mnemonic = "psrld";
         } else if (opcode == 0xD3) {
-          mnemonic = "psrld";
+          mnemonic = "psrlq";
         } else if (opcode == 0xD4) {
           mnemonic = "paddq";
         } else if (opcode == 0xD5) {
diff --git a/deps/v8/src/execution/arguments-inl.h b/deps/v8/src/execution/arguments-inl.h
index 4565f5d265..0be2325837 100644
--- a/deps/v8/src/execution/arguments-inl.h
+++ b/deps/v8/src/execution/arguments-inl.h
@@ -9,20 +9,26 @@
 
 #include "src/handles/handles-inl.h"
 #include "src/objects/objects-inl.h"  // TODO(jkummerow): Just smi-inl.h.
+#include "src/objects/tagged-index.h"
 
 namespace v8 {
 namespace internal {
 
-template <class S>
-Handle<S> Arguments::at(int index) const {
-  return Handle<S>::cast(at<Object>(index));
+template <ArgumentsType T>
+int Arguments<T>::smi_at(int index) const {
+  return Smi::ToInt(Object(*address_of_arg_at(index)));
 }
 
-int Arguments::smi_at(int index) const {
-  return Smi::ToInt(Object(*address_of_arg_at(index)));
+template <ArgumentsType T>
+int Arguments<T>::tagged_index_at(int index) const {
+  Address raw = *address_of_arg_at(index);
+  return static_cast<int>(TaggedIndex(raw).value());
 }
 
-double Arguments::number_at(int index) const { return (*this)[index].Number(); }
+template <ArgumentsType T>
+double Arguments<T>::number_at(int index) const {
+  return (*this)[index].Number();
+}
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/execution/arguments.h b/deps/v8/src/execution/arguments.h
index 77bbe62dfc..d2798e6f76 100644
--- a/deps/v8/src/execution/arguments.h
+++ b/deps/v8/src/execution/arguments.h
@@ -30,6 +30,7 @@ namespace internal {
 // Note that length_ (whose value is in the integer range) is defined
 // as intptr_t to provide endian-neutrality on 64-bit archs.
 
+template <ArgumentsType arguments_type>
 class Arguments {
  public:
   Arguments(int length, Address* arguments)
@@ -46,6 +47,8 @@ class Arguments {
 
   inline int smi_at(int index) const;
 
+  inline int tagged_index_at(int index) const;
+
   inline double number_at(int index) const;
 
   inline void set_at(int index, Object value) {
@@ -57,26 +60,47 @@ class Arguments {
   }
 
   inline Address* address_of_arg_at(int index) const {
-    DCHECK_LT(static_cast<uint32_t>(index), static_cast<uint32_t>(length_));
+    DCHECK_LE(static_cast<uint32_t>(index), static_cast<uint32_t>(length_));
+    uintptr_t offset = index * kSystemPointerSize;
+#ifdef V8_REVERSE_JSARGS
+    if (arguments_type == ArgumentsType::kJS) {
+      offset = (length_ - index - 1) * kSystemPointerSize;
+    }
+#endif
     return reinterpret_cast<Address*>(reinterpret_cast<Address>(arguments_) -
-                                      index * kSystemPointerSize);
+                                      offset);
   }
 
   // Get the total number of arguments including the receiver.
   int length() const { return static_cast<int>(length_); }
 
   // Arguments on the stack are in reverse order (compared to an array).
-  FullObjectSlot first_slot() const { return slot_at(length() - 1); }
-  FullObjectSlot last_slot() const { return slot_at(0); }
+  FullObjectSlot first_slot() const {
+    int index = length() - 1;
+#ifdef V8_REVERSE_JSARGS
+    if (arguments_type == ArgumentsType::kJS) index = 0;
+#endif
+    return slot_at(index);
+  }
+
+  FullObjectSlot last_slot() const {
+    int index = 0;
+#ifdef V8_REVERSE_JSARGS
+    if (arguments_type == ArgumentsType::kJS) index = length() - 1;
+#endif
+    return slot_at(index);
+  }
 
  private:
   intptr_t length_;
   Address* arguments_;
 };
 
-template <>
-inline Handle<Object> Arguments::at(int index) const {
-  return Handle<Object>(address_of_arg_at(index));
+template <ArgumentsType T>
+template <class S>
+Handle<S> Arguments<T>::at(int index) const {
+  Handle<Object> obj = Handle<Object>(address_of_arg_at(index));
+  return Handle<S>::cast(obj);
 }
 
 double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
@@ -90,7 +114,7 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
 // TODO(cbruni): add global flag to check whether any tracing events have been
 // enabled.
 #define RUNTIME_FUNCTION_RETURNS_TYPE(Type, InternalType, Convert, Name)      \
-  static V8_INLINE InternalType __RT_impl_##Name(Arguments args,              \
+  static V8_INLINE InternalType __RT_impl_##Name(RuntimeArguments args,       \
                                                  Isolate* isolate);           \
                                                                               \
   V8_NOINLINE static Type Stats_##Name(int args_length, Address* args_object, \
@@ -98,7 +122,7 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
     RuntimeCallTimerScope timer(isolate, RuntimeCallCounterId::k##Name);      \
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                     \
                  "V8.Runtime_" #Name);                                        \
-    Arguments args(args_length, args_object);                                 \
+    RuntimeArguments args(args_length, args_object);                          \
     return Convert(__RT_impl_##Name(args, isolate));                          \
   }                                                                           \
                                                                               \
@@ -108,11 +132,11 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
     if (V8_UNLIKELY(TracingFlags::is_runtime_stats_enabled())) {              \
       return Stats_##Name(args_length, args_object, isolate);                 \
     }                                                                         \
-    Arguments args(args_length, args_object);                                 \
+    RuntimeArguments args(args_length, args_object);                          \
     return Convert(__RT_impl_##Name(args, isolate));                          \
   }                                                                           \
                                                                               \
-  static InternalType __RT_impl_##Name(Arguments args, Isolate* isolate)
+  static InternalType __RT_impl_##Name(RuntimeArguments args, Isolate* isolate)
 
 #define CONVERT_OBJECT(x) (x).ptr()
 #define CONVERT_OBJECTPAIR(x) (x)
diff --git a/deps/v8/src/execution/arm/frame-constants-arm.h b/deps/v8/src/execution/arm/frame-constants-arm.h
index faa3cc8ab7..cd9c4527b3 100644
--- a/deps/v8/src/execution/arm/frame-constants-arm.h
+++ b/deps/v8/src/execution/arm/frame-constants-arm.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_ARM_FRAME_CONSTANTS_ARM_H_
 #define V8_EXECUTION_ARM_FRAME_CONSTANTS_ARM_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -36,6 +37,44 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {r0, r1, r2, r3, r4, r5, r6, r8, r9}
+  static constexpr uint32_t kPushedGpRegs = 0b1101111111;
+  // {d0 .. d12}
+  static constexpr int kFirstPushedFpReg = 0;
+  static constexpr int kLastPushedFpReg = 12;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      kLastPushedFpReg - kFirstPushedFpReg + 1;
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -TypedFrameConstants::kFixedFrameSizeFromFp -
+      kSystemPointerSize * kNumPushedGpRegisters;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kDoubleSize * kNumPushedFpRegisters;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_LE(kFirstPushedFpReg, reg_code);
+    DCHECK_GE(kLastPushedFpReg, reg_code);
+    return kLastPushedFpRegisterOffset +
+           (reg_code - kFirstPushedFpReg) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/arm/simulator-arm.cc b/deps/v8/src/execution/arm/simulator-arm.cc
index 193a996676..a409dc97d2 100644
--- a/deps/v8/src/execution/arm/simulator-arm.cc
+++ b/deps/v8/src/execution/arm/simulator-arm.cc
@@ -19,6 +19,7 @@
 #include "src/codegen/macro-assembler.h"
 #include "src/diagnostics/disasm.h"
 #include "src/heap/combined-heap.h"
+#include "src/heap/heap-inl.h"  // For CodeSpaceMemoryModificationScope.
 #include "src/objects/objects-inl.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/utils/ostreams.h"
@@ -43,8 +44,6 @@ DEFINE_LAZY_LEAKY_OBJECT_GETTER(Simulator::GlobalMonitor,
 class ArmDebugger {
  public:
   explicit ArmDebugger(Simulator* sim) : sim_(sim) {}
-
-  void Stop(Instruction* instr);
   void Debug();
 
  private:
@@ -61,26 +60,20 @@ class ArmDebugger {
   bool GetVFPSingleValue(const char* desc, float* value);
   bool GetVFPDoubleValue(const char* desc, double* value);
 
-  // Set or delete a breakpoint. Returns true if successful.
+  // Set or delete breakpoint (there can be only one).
   bool SetBreakpoint(Instruction* breakpc);
-  bool DeleteBreakpoint(Instruction* breakpc);
+  void DeleteBreakpoint();
 
-  // Undo and redo all breakpoints. This is needed to bracket disassembly and
-  // execution to skip past breakpoints when run from the debugger.
-  void UndoBreakpoints();
-  void RedoBreakpoints();
+  // Undo and redo the breakpoint. This is needed to bracket disassembly and
+  // execution to skip past the breakpoint when run from the debugger.
+  void UndoBreakpoint();
+  void RedoBreakpoint();
 };
 
-void ArmDebugger::Stop(Instruction* instr) {
-  // Get the stop code.
-  uint32_t code = instr->SvcValue() & kStopCodeMask;
-  // Print the stop message and code if it is not the default code.
-  if (code != kMaxStopCode) {
-    PrintF("Simulator hit stop %u\n", code);
-  } else {
-    PrintF("Simulator hit\n");
-  }
-  Debug();
+void Simulator::DebugAtNextPC() {
+  PrintF("Starting debugger on the next instruction:\n");
+  set_pc(get_pc() + kInstrSize);
+  ArmDebugger(this).Debug();
 }
 
 int32_t ArmDebugger::GetRegisterValue(int regnum) {
@@ -148,25 +141,33 @@ bool ArmDebugger::SetBreakpoint(Instruction* breakpc) {
   return true;
 }
 
-bool ArmDebugger::DeleteBreakpoint(Instruction* breakpc) {
-  if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
-  }
+namespace {
+// This function is dangerous, but it's only available in non-production
+// (simulator) builds.
+void SetInstructionBitsInCodeSpace(Instruction* instr, Instr value,
+                                   Heap* heap) {
+  CodeSpaceMemoryModificationScope scope(heap);
+  instr->SetInstructionBits(value);
+}
+}  // namespace
 
+void ArmDebugger::DeleteBreakpoint() {
+  UndoBreakpoint();
   sim_->break_pc_ = nullptr;
   sim_->break_instr_ = 0;
-  return true;
 }
 
-void ArmDebugger::UndoBreakpoints() {
+void ArmDebugger::UndoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, sim_->break_instr_,
+                                  sim_->isolate_->heap());
   }
 }
 
-void ArmDebugger::RedoBreakpoints() {
+void ArmDebugger::RedoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(kBreakpointInstr);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, kBreakpointInstr,
+                                  sim_->isolate_->heap());
   }
 }
 
@@ -190,9 +191,9 @@ void ArmDebugger::Debug() {
   arg1[ARG_SIZE] = 0;
   arg2[ARG_SIZE] = 0;
 
-  // Undo all set breakpoints while running in the debugger shell. This will
-  // make them invisible to all commands.
-  UndoBreakpoints();
+  // Unset breakpoint while running in the debugger shell, making it invisible
+  // to all commands.
+  UndoBreakpoint();
 
   while (!done && !sim_->has_bad_pc()) {
     if (last_pc != sim_->get_pc()) {
@@ -292,7 +293,8 @@ void ArmDebugger::Debug() {
         } else {
           PrintF("printobject <value>\n");
         }
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         int32_t* cur = nullptr;
         int32_t* end = nullptr;
         int next_arg = 1;
@@ -319,20 +321,23 @@ void ArmDebugger::Debug() {
         }
         end = cur + words;
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%08" V8PRIxPTR ":  0x%08x %10d",
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
           Object obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
-          if (obj.IsSmi() ||
-              IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            if (obj.IsSmi()) {
-              PrintF("smi %d", Smi::ToInt(obj));
-            } else {
-              obj.ShortPrint();
+          if (!skip_obj_print) {
+            if (obj.IsSmi() ||
+                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              if (obj.IsSmi()) {
+                PrintF("smi %d", Smi::ToInt(obj));
+              } else {
+                obj.ShortPrint();
+              }
+              PrintF(")");
             }
-            PrintF(")");
           }
           PrintF("\n");
           cur++;
@@ -402,9 +407,7 @@ void ArmDebugger::Debug() {
           PrintF("break <address>\n");
         }
       } else if (strcmp(cmd, "del") == 0) {
-        if (!DeleteBreakpoint(nullptr)) {
-          PrintF("deleting breakpoint failed\n");
-        }
+        DeleteBreakpoint();
       } else if (strcmp(cmd, "flags") == 0) {
         PrintF("N flag: %d; ", sim_->n_flag_);
         PrintF("Z flag: %d; ", sim_->z_flag_);
@@ -421,8 +424,9 @@ void ArmDebugger::Debug() {
         Instruction* stop_instr = reinterpret_cast<Instruction*>(stop_pc);
         if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
           // Remove the current stop.
-          if (sim_->isStopInstruction(stop_instr)) {
-            stop_instr->SetInstructionBits(kNopInstr);
+          if (stop_instr->IsStop()) {
+            SetInstructionBitsInCodeSpace(stop_instr, kNopInstr,
+                                          sim_->isolate_->heap());
           } else {
             PrintF("Not at debugger stop.\n");
           }
@@ -486,6 +490,10 @@ void ArmDebugger::Debug() {
         PrintF("  dump stack content, default dump 10 words)\n");
         PrintF("mem <address> [<words>]\n");
         PrintF("  dump memory content, default dump 10 words)\n");
+        PrintF("dump [<words>]\n");
+        PrintF(
+            "  dump memory content without pretty printing JS objects, default "
+            "dump 10 words)\n");
         PrintF("disasm [<instructions>]\n");
         PrintF("disasm [<address/register>]\n");
         PrintF("disasm [[<address/register>] <instructions>]\n");
@@ -526,9 +534,9 @@ void ArmDebugger::Debug() {
     }
   }
 
-  // Add all the breakpoints back to stop execution and enter the debugger
-  // shell when hit.
-  RedoBreakpoints();
+  // Reinstall breakpoint to stop execution and enter the debugger shell when
+  // hit.
+  RedoBreakpoint();
 
 #undef COMMAND_SIZE
 #undef ARG_SIZE
@@ -1785,13 +1793,11 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       set_pc(get_register(lr));
       break;
     }
-    case kBreakpoint: {
-      ArmDebugger dbg(this);
-      dbg.Debug();
+    case kBreakpoint:
+      ArmDebugger(this).Debug();
       break;
-    }
     // stop uses all codes greater than 1 << 23.
-    default: {
+    default:
       if (svc >= (1 << 23)) {
         uint32_t code = svc & kStopCodeMask;
         if (isWatchedStop(code)) {
@@ -1800,15 +1806,17 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         // Stop if it is enabled, otherwise go on jumping over the stop
         // and the message address.
         if (isEnabledStop(code)) {
-          ArmDebugger dbg(this);
-          dbg.Stop(instr);
+          if (code != kMaxStopCode) {
+            PrintF("Simulator hit stop %u. ", code);
+          } else {
+            PrintF("Simulator hit stop. ");
+          }
+          DebugAtNextPC();
         }
       } else {
         // This is not a valid svc code.
         UNREACHABLE();
-        break;
       }
-    }
   }
 }
 
@@ -1848,10 +1856,6 @@ Float64 Simulator::canonicalizeNaN(Float64 value) {
 }
 
 // Stop helper functions.
-bool Simulator::isStopInstruction(Instruction* instr) {
-  return (instr->Bits(27, 24) == 0xF) && (instr->SvcValue() >= kStopCode);
-}
-
 bool Simulator::isWatchedStop(uint32_t code) {
   DCHECK_LE(code, kMaxStopCode);
   return code < kNumOfWatchedStops;
@@ -2243,12 +2247,10 @@ void Simulator::DecodeType01(Instruction* instr) {
           set_register(lr, old_pc + kInstrSize);
           break;
         }
-        case BKPT: {
-          ArmDebugger dbg(this);
-          PrintF("Simulator hit BKPT.\n");
-          dbg.Debug();
+        case BKPT:
+          PrintF("Simulator hit BKPT. ");
+          DebugAtNextPC();
           break;
-        }
         default:
           UNIMPLEMENTED();
       }
diff --git a/deps/v8/src/execution/arm/simulator-arm.h b/deps/v8/src/execution/arm/simulator-arm.h
index 0a21b30ac3..e577e0f815 100644
--- a/deps/v8/src/execution/arm/simulator-arm.h
+++ b/deps/v8/src/execution/arm/simulator-arm.h
@@ -330,9 +330,9 @@ class Simulator : public SimulatorBase {
   void HandleRList(Instruction* instr, bool load);
   void HandleVList(Instruction* inst);
   void SoftwareInterrupt(Instruction* instr);
+  void DebugAtNextPC();
 
   // Stop helper functions.
-  inline bool isStopInstruction(Instruction* instr);
   inline bool isWatchedStop(uint32_t bkpt_code);
   inline bool isEnabledStop(uint32_t bkpt_code);
   inline void EnableStop(uint32_t bkpt_code);
diff --git a/deps/v8/src/execution/arm64/frame-constants-arm64.h b/deps/v8/src/execution/arm64/frame-constants-arm64.h
index 4617d48d71..4a09e5b911 100644
--- a/deps/v8/src/execution/arm64/frame-constants-arm64.h
+++ b/deps/v8/src/execution/arm64/frame-constants-arm64.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_ARM64_FRAME_CONSTANTS_ARM64_H_
 #define V8_EXECUTION_ARM64_FRAME_CONSTANTS_ARM64_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/common/globals.h"
 #include "src/execution/frame-constants.h"
@@ -87,6 +88,46 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {x0 .. x28} \ {x16, x17, x18, x26, x27}
+  static constexpr uint32_t kPushedGpRegs =
+      (1 << 29) - 1 - (1 << 16) - (1 << 17) - (1 << 18) - (1 << 26) - (1 << 27);
+  // {d0 .. d29}; {d15} is not used, but we still keep it for alignment reasons
+  // (the frame size needs to be a multiple of 16).
+  static constexpr uint32_t kPushedFpRegs = (1 << 30) - 1;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      // Header is padded to 16 byte (see {MacroAssembler::EnterFrame}).
+      -RoundUp<16>(TypedFrameConstants::kFixedFrameSizeFromFp) -
+      kSystemPointerSize * kNumPushedGpRegisters;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kDoubleSize * kNumPushedFpRegisters;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/arm64/pointer-authentication-arm64.h b/deps/v8/src/execution/arm64/pointer-authentication-arm64.h
new file mode 100644
index 0000000000..c54a59f29c
--- /dev/null
+++ b/deps/v8/src/execution/arm64/pointer-authentication-arm64.h
@@ -0,0 +1,164 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_EXECUTION_ARM64_POINTER_AUTHENTICATION_ARM64_H_
+#define V8_EXECUTION_ARM64_POINTER_AUTHENTICATION_ARM64_H_
+
+#include "src/execution/pointer-authentication.h"
+
+#include "src/common/globals.h"
+#include "src/execution/arm64/simulator-arm64.h"
+
+// TODO(v8:10026): Replace hints with instruction aliases, when supported.
+#define AUTIA1716 "hint #12"
+#define PACIA1716 "hint #8"
+#define XPACLRI "hint #7"
+
+namespace v8 {
+namespace internal {
+
+// The following functions execute on the host and therefore need a different
+// path based on whether we are simulating arm64 or not.
+
+// clang-format fails to detect this file as C++, turn it off.
+// clang-format off
+
+// Authenticate the address stored in {pc_address}. {offset_from_sp} is the
+// offset between {pc_address} and the pointer used as a context for signing.
+V8_INLINE Address PointerAuthentication::AuthenticatePC(
+    Address* pc_address, unsigned offset_from_sp) {
+  uint64_t sp = reinterpret_cast<uint64_t>(pc_address) + offset_from_sp;
+  uint64_t pc = reinterpret_cast<uint64_t>(*pc_address);
+#ifdef USE_SIMULATOR
+  pc = Simulator::AuthPAC(pc, sp, Simulator::kPACKeyIA,
+                          Simulator::kInstructionPointer);
+#else
+  asm volatile(
+      "  mov x17, %[pc]\n"
+      "  mov x16, %[stack_ptr]\n"
+      "  " AUTIA1716 "\n"
+      "  ldr xzr, [x17]\n"
+      "  mov %[pc], x17\n"
+      : [pc] "+r"(pc)
+      : [stack_ptr] "r"(sp)
+      : "x16", "x17");
+#endif
+  return pc;
+}
+
+// Strip Pointer Authentication Code (PAC) from {pc} and return the raw value.
+V8_INLINE Address PointerAuthentication::StripPAC(Address pc) {
+#ifdef USE_SIMULATOR
+  return Simulator::StripPAC(pc, Simulator::kInstructionPointer);
+#else
+  asm volatile(
+      "  mov x16, lr\n"
+      "  mov lr, %[pc]\n"
+      "  " XPACLRI "\n"
+      "  mov %[pc], lr\n"
+      "  mov lr, x16\n"
+      : [pc] "+r"(pc)
+      :
+      : "x16", "lr");
+  return pc;
+#endif
+}
+
+// Sign {pc} using {sp}.
+V8_INLINE Address PointerAuthentication::SignPCWithSP(Address pc, Address sp) {
+#ifdef USE_SIMULATOR
+  return Simulator::AddPAC(pc, sp, Simulator::kPACKeyIA,
+                           Simulator::kInstructionPointer);
+#else
+  asm volatile(
+      "  mov x17, %[pc]\n"
+      "  mov x16, %[sp]\n"
+      "  " PACIA1716 "\n"
+      "  mov %[pc], x17\n"
+      : [pc] "+r"(pc)
+      : [sp] "r"(sp)
+      : "x16", "x17");
+  return pc;
+#endif
+}
+
+// Authenticate the address stored in {pc_address} and replace it with
+// {new_pc}, after signing it. {offset_from_sp} is the offset between
+// {pc_address} and the pointer used as a context for signing.
+V8_INLINE void PointerAuthentication::ReplacePC(Address* pc_address,
+                                                Address new_pc,
+                                                int offset_from_sp) {
+  uint64_t sp = reinterpret_cast<uint64_t>(pc_address) + offset_from_sp;
+  uint64_t old_pc = reinterpret_cast<uint64_t>(*pc_address);
+#ifdef USE_SIMULATOR
+  uint64_t auth_old_pc = Simulator::AuthPAC(old_pc, sp, Simulator::kPACKeyIA,
+                                            Simulator::kInstructionPointer);
+  uint64_t raw_old_pc =
+      Simulator::StripPAC(old_pc, Simulator::kInstructionPointer);
+  // Verify that the old address is authenticated.
+  CHECK_EQ(auth_old_pc, raw_old_pc);
+  new_pc = Simulator::AddPAC(new_pc, sp, Simulator::kPACKeyIA,
+                             Simulator::kInstructionPointer);
+#else
+  // Only store newly signed address after we have verified that the old
+  // address is authenticated.
+  asm volatile(
+      "  mov x17, %[new_pc]\n"
+      "  mov x16, %[sp]\n"
+      "  " PACIA1716 "\n"
+      "  mov %[new_pc], x17\n"
+      "  mov x17, %[old_pc]\n"
+      "  " AUTIA1716 "\n"
+      "  ldr xzr, [x17]\n"
+      : [new_pc] "+&r"(new_pc)
+      : [sp] "r"(sp), [old_pc] "r"(old_pc)
+      : "x16", "x17");
+#endif
+  *pc_address = new_pc;
+}
+
+// Authenticate the address stored in {pc_address} based on {old_context} and
+// replace it with the same address signed with {new_context} instead.
+V8_INLINE void PointerAuthentication::ReplaceContext(Address* pc_address,
+                                                     Address old_context,
+                                                     Address new_context) {
+  uint64_t old_signed_pc = static_cast<uint64_t>(*pc_address);
+  uint64_t new_pc;
+#ifdef USE_SIMULATOR
+  uint64_t auth_pc =
+      Simulator::AuthPAC(old_signed_pc, old_context, Simulator::kPACKeyIA,
+                         Simulator::kInstructionPointer);
+  uint64_t raw_pc =
+      Simulator::StripPAC(auth_pc, Simulator::kInstructionPointer);
+  // Verify that the old address is authenticated.
+  CHECK_EQ(raw_pc, auth_pc);
+  new_pc = Simulator::AddPAC(raw_pc, new_context, Simulator::kPACKeyIA,
+                             Simulator::kInstructionPointer);
+#else
+  // Only store newly signed address after we have verified that the old
+  // address is authenticated.
+  asm volatile(
+      "  mov x17, %[old_pc]\n"
+      "  mov x16, %[old_ctx]\n"
+      "  " AUTIA1716 "\n"
+      "  mov x16, %[new_ctx]\n"
+      "  " PACIA1716 "\n"
+      "  mov %[new_pc], x17\n"
+      "  mov x17, %[old_pc]\n"
+      "  mov x16, %[old_ctx]\n"
+      "  " AUTIA1716 "\n"
+      "  ldr xzr, [x17]\n"
+      : [new_pc] "=&r"(new_pc)
+      : [old_pc] "r"(old_signed_pc), [old_ctx] "r"(old_context),
+        [new_ctx] "r"(new_context)
+      : "x16", "x17");
+#endif
+  *pc_address = new_pc;
+}
+
+// clang-format on
+
+}  // namespace internal
+}  // namespace v8
+#endif  // V8_EXECUTION_ARM64_POINTER_AUTHENTICATION_ARM64_H_
diff --git a/deps/v8/src/execution/arm64/simulator-arm64.cc b/deps/v8/src/execution/arm64/simulator-arm64.cc
index 8ee43c07e8..adc856a606 100644
--- a/deps/v8/src/execution/arm64/simulator-arm64.cc
+++ b/deps/v8/src/execution/arm64/simulator-arm64.cc
@@ -194,11 +194,13 @@ void Simulator::CheckPCSComplianceAndRun() {
     saved_fpregisters[i] = dreg_bits(PopLowestIndexAsCode(&fpregister_list));
   }
   int64_t original_stack = sp();
+  int64_t original_fp = fp();
 #endif
   // Start the simulation!
   Run();
 #ifdef DEBUG
   DCHECK_EQ(original_stack, sp());
+  DCHECK_EQ(original_fp, fp());
   // Check that callee-saved registers have been preserved.
   register_list = kCalleeSaved;
   fpregister_list = kCalleeSavedV;
@@ -298,8 +300,10 @@ void Simulator::SetRedirectInstruction(Instruction* instruction) {
 Simulator::Simulator(Decoder<DispatchingDecoderVisitor>* decoder,
                      Isolate* isolate, FILE* stream)
     : decoder_(decoder),
+      guard_pages_(ENABLE_CONTROL_FLOW_INTEGRITY_BOOL),
       last_debugger_input_(nullptr),
       log_parameters_(NO_PARAM),
+      icount_for_stop_sim_at_(0),
       isolate_(isolate) {
   // Setup the decoder.
   decoder_->AppendVisitor(this);
@@ -314,6 +318,7 @@ Simulator::Simulator(Decoder<DispatchingDecoderVisitor>* decoder,
 
 Simulator::Simulator()
     : decoder_(nullptr),
+      guard_pages_(ENABLE_CONTROL_FLOW_INTEGRITY_BOOL),
       last_debugger_input_(nullptr),
       log_parameters_(NO_PARAM),
       isolate_(nullptr) {
@@ -361,6 +366,8 @@ void Simulator::ResetState() {
   // Reset debug helpers.
   breakpoints_.clear();
   break_on_next_ = false;
+
+  btype_ = DefaultBType;
 }
 
 Simulator::~Simulator() {
@@ -378,8 +385,24 @@ void Simulator::Run() {
   LogAllWrittenRegisters();
 
   pc_modified_ = false;
-  while (pc_ != kEndOfSimAddress) {
-    ExecuteInstruction();
+
+  if (::v8::internal::FLAG_stop_sim_at == 0) {
+    // Fast version of the dispatch loop without checking whether the simulator
+    // should be stopping at a particular executed instruction.
+    while (pc_ != kEndOfSimAddress) {
+      ExecuteInstruction();
+    }
+  } else {
+    // FLAG_stop_sim_at is at the non-default value. Stop in the debugger when
+    // we reach the particular instruction count.
+    while (pc_ != kEndOfSimAddress) {
+      icount_for_stop_sim_at_ =
+          base::AddWithWraparound(icount_for_stop_sim_at_, 1);
+      if (icount_for_stop_sim_at_ == ::v8::internal::FLAG_stop_sim_at) {
+        Debug();
+      }
+      ExecuteInstruction();
+    }
   }
 }
 
@@ -1494,6 +1517,20 @@ void Simulator::VisitConditionalBranch(Instruction* instr) {
   }
 }
 
+Simulator::BType Simulator::GetBTypeFromInstruction(
+    const Instruction* instr) const {
+  switch (instr->Mask(UnconditionalBranchToRegisterMask)) {
+    case BLR:
+      return BranchAndLink;
+    case BR:
+      if (!PcIsInGuardedPage() || (instr->Rn() == 16) || (instr->Rn() == 17)) {
+        return BranchFromUnguardedOrToIP;
+      }
+      return BranchFromGuardedNotToIP;
+  }
+  return DefaultBType;
+}
+
 void Simulator::VisitUnconditionalBranchToRegister(Instruction* instr) {
   Instruction* target = reg<Instruction*>(instr->Rn());
   switch (instr->Mask(UnconditionalBranchToRegisterMask)) {
@@ -1513,6 +1550,7 @@ void Simulator::VisitUnconditionalBranchToRegister(Instruction* instr) {
     default:
       UNIMPLEMENTED();
   }
+  set_btype(GetBTypeFromInstruction(instr));
 }
 
 void Simulator::VisitTestBranch(Instruction* instr) {
@@ -3096,6 +3134,7 @@ void Simulator::VisitSystem(Instruction* instr) {
   // range of immediates instead of indicating a different instruction. This
   // makes the decoding tricky.
   if (instr->Mask(SystemPAuthFMask) == SystemPAuthFixed) {
+    // The BType check for PACIASP happens in CheckBType().
     switch (instr->Mask(SystemPAuthMask)) {
 #define DEFINE_PAUTH_FUNCS(SUFFIX, DST, MOD, KEY)                     \
   case PACI##SUFFIX:                                                  \
@@ -3145,6 +3184,11 @@ void Simulator::VisitSystem(Instruction* instr) {
     switch (instr->ImmHint()) {
       case NOP:
       case CSDB:
+      case BTI_jc:
+      case BTI:
+      case BTI_c:
+      case BTI_j:
+        // The BType checks happen in CheckBType().
         break;
       default:
         UNIMPLEMENTED();
@@ -3386,7 +3430,8 @@ void Simulator::Debug() {
 
         // stack / mem
         // ----------------------------------------------------------
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         int64_t* cur = nullptr;
         int64_t* end = nullptr;
         int next_arg = 1;
@@ -3418,20 +3463,23 @@ void Simulator::Debug() {
         }
         end = cur + words;
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%016" PRIx64 ":  0x%016" PRIx64 " %10" PRId64,
                  reinterpret_cast<uint64_t>(cur), *cur, *cur);
-          Object obj(*cur);
-          Heap* current_heap = isolate_->heap();
-          if (obj.IsSmi() ||
-              IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            if (obj.IsSmi()) {
-              PrintF("smi %" PRId32, Smi::ToInt(obj));
-            } else {
-              obj.ShortPrint();
+          if (!skip_obj_print) {
+            Object obj(*cur);
+            Heap* current_heap = isolate_->heap();
+            if (obj.IsSmi() ||
+                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              if (obj.IsSmi()) {
+                PrintF("smi %" PRId32, Smi::ToInt(obj));
+              } else {
+                obj.ShortPrint();
+              }
+              PrintF(")");
             }
-            PrintF(")");
           }
           PrintF("\n");
           cur++;
@@ -3440,13 +3488,12 @@ void Simulator::Debug() {
         // trace / t
         // -------------------------------------------------------------
       } else if (strcmp(cmd, "trace") == 0 || strcmp(cmd, "t") == 0) {
-        if ((log_parameters() & (LOG_DISASM | LOG_REGS)) !=
-            (LOG_DISASM | LOG_REGS)) {
-          PrintF("Enabling disassembly and registers tracing\n");
-          set_log_parameters(log_parameters() | LOG_DISASM | LOG_REGS);
+        if ((log_parameters() & LOG_ALL) != LOG_ALL) {
+          PrintF("Enabling disassembly, registers and memory write tracing\n");
+          set_log_parameters(log_parameters() | LOG_ALL);
         } else {
-          PrintF("Disabling disassembly and registers tracing\n");
-          set_log_parameters(log_parameters() & ~(LOG_DISASM | LOG_REGS));
+          PrintF("Disabling disassembly, registers and memory write tracing\n");
+          set_log_parameters(log_parameters() & ~LOG_ALL);
         }
 
         // break / b
@@ -3509,6 +3556,10 @@ void Simulator::Debug() {
             "mem\n"
             "    mem <address> [<words>]\n"
             "    Dump memory content, default dump 10 words\n"
+            "dump\n"
+            "    dump <address> [<words>]\n"
+            "    Dump memory content without pretty printing JS objects, "
+            "default dump 10 words\n"
             "trace / t\n"
             "    Toggle disassembly and register tracing\n"
             "break / b\n"
diff --git a/deps/v8/src/execution/arm64/simulator-arm64.h b/deps/v8/src/execution/arm64/simulator-arm64.h
index ae3b6867a9..cd4137c8e5 100644
--- a/deps/v8/src/execution/arm64/simulator-arm64.h
+++ b/deps/v8/src/execution/arm64/simulator-arm64.h
@@ -770,8 +770,125 @@ class Simulator : public DecoderVisitor, public SimulatorBase {
 
   virtual void Decode(Instruction* instr) { decoder_->Decode(instr); }
 
+  // Branch Target Identification (BTI)
+  //
+  // Executing an instruction updates PSTATE.BTYPE, as described in the table
+  // below. Execution of an instruction on a guarded page is allowed if either:
+  // * PSTATE.BTYPE is 00, or
+  // * it is a BTI or PACI[AB]SP instruction that accepts the current value of
+  //   PSTATE.BTYPE (as described in the table below), or
+  // * it is BRK or HLT instruction that causes some higher-priority exception.
+  //
+  //  --------------------------------------------------------------------------
+  //  | Last-executed instruction    | Sets     | Accepted by                  |
+  //  |                              | BTYPE to | BTI | BTI j | BTI c | BTI jc |
+  //  --------------------------------------------------------------------------
+  //  | - BR from an unguarded page. |          |     |       |       |        |
+  //  | - BR from guarded page,      |          |     |       |       |        |
+  //  |   to x16 or x17.             |    01    |     |   X   |   X   |   X    |
+  //  --------------------------------------------------------------------------
+  //  | BR from guarded page,        |          |     |       |       |        |
+  //  | not to x16 or x17.           |    11    |     |   X   |       |   X    |
+  //  --------------------------------------------------------------------------
+  //  | BLR                          |    10    |     |       |   X   |   X    |
+  //  --------------------------------------------------------------------------
+  //  | Any other instruction        |          |     |       |       |        |
+  //  |(including RET).              |    00    |  X  |   X   |   X   |   X    |
+  //  --------------------------------------------------------------------------
+  //
+  // PACI[AB]SP is treated either like "BTI c" or "BTI jc", according to the
+  // value of SCTLR_EL1.BT0. Details available in ARM DDI 0487E.a, D5-2580.
+
+  enum BType {
+    // Set when executing any instruction, except those cases listed below.
+    DefaultBType = 0,
+
+    // Set when an indirect branch is taken from an unguarded page, or from a
+    // guarded page to ip0 or ip1 (x16 or x17), eg "br ip0".
+    BranchFromUnguardedOrToIP = 1,
+
+    // Set when an indirect branch and link (call) is taken, eg. "blr x0".
+    BranchAndLink = 2,
+
+    // Set when an indirect branch is taken from a guarded page to a register
+    // that is not ip0 or ip1 (x16 or x17), eg, "br x0".
+    BranchFromGuardedNotToIP = 3
+  };
+
+  BType btype() const { return btype_; }
+  void ResetBType() { btype_ = DefaultBType; }
+  void set_btype(BType btype) { btype_ = btype; }
+
+  // Helper function to determine BType for branches.
+  BType GetBTypeFromInstruction(const Instruction* instr) const;
+
+  bool PcIsInGuardedPage() const { return guard_pages_; }
+  void SetGuardedPages(bool guard_pages) { guard_pages_ = guard_pages; }
+
+  void CheckBTypeForPAuth() {
+    DCHECK(pc_->IsPAuth());
+    Instr instr = pc_->Mask(SystemPAuthMask);
+    // Only PACI[AB]SP allowed here, but we don't currently support PACIBSP.
+    CHECK_EQ(instr, PACIASP);
+    // Check BType allows PACI[AB]SP instructions.
+    switch (btype()) {
+      case BranchFromGuardedNotToIP:
+        // This case depends on the value of SCTLR_EL1.BT0, which we assume
+        // here to be set. This makes PACI[AB]SP behave like "BTI c",
+        // disallowing its execution when BTYPE is BranchFromGuardedNotToIP
+        // (0b11).
+        FATAL("Executing PACIASP with wrong BType.");
+      case BranchFromUnguardedOrToIP:
+      case BranchAndLink:
+        break;
+      case DefaultBType:
+        UNREACHABLE();
+    }
+  }
+
+  void CheckBTypeForBti() {
+    DCHECK(pc_->IsBti());
+    switch (pc_->ImmHint()) {
+      case BTI_jc:
+        break;
+      case BTI: {
+        DCHECK(btype() != DefaultBType);
+        FATAL("Executing BTI with wrong BType (expected 0, got %d).", btype());
+        break;
+      }
+      case BTI_c:
+        if (btype() == BranchFromGuardedNotToIP) {
+          FATAL("Executing BTI c with wrong BType (3).");
+        }
+        break;
+      case BTI_j:
+        if (btype() == BranchAndLink) {
+          FATAL("Executing BTI j with wrong BType (2).");
+        }
+        break;
+      default:
+        UNIMPLEMENTED();
+    }
+  }
+
+  void CheckBType() {
+    // On guarded pages, if BType is not zero, take an exception on any
+    // instruction other than BTI, PACI[AB]SP, HLT or BRK.
+    if (PcIsInGuardedPage() && (btype() != DefaultBType)) {
+      if (pc_->IsPAuth()) {
+        CheckBTypeForPAuth();
+      } else if (pc_->IsBti()) {
+        CheckBTypeForBti();
+      } else if (!pc_->IsException()) {
+        FATAL("Executing non-BTI instruction with wrong BType.");
+      }
+    }
+  }
+
   void ExecuteInstruction() {
     DCHECK(IsAligned(reinterpret_cast<uintptr_t>(pc_), kInstrSize));
+    CheckBType();
+    ResetBType();
     CheckBreakNext();
     Decode(pc_);
     increment_pc();
@@ -2192,6 +2309,13 @@ class Simulator : public DecoderVisitor, public SimulatorBase {
   bool pc_modified_;
   Instruction* pc_;
 
+  // Branch type register, used for branch target identification.
+  BType btype_;
+
+  // Global flag for enabling guarded pages.
+  // TODO(arm64): implement guarding at page granularity, rather than globally.
+  bool guard_pages_;
+
   static const char* xreg_names[];
   static const char* wreg_names[];
   static const char* sreg_names[];
@@ -2368,6 +2492,8 @@ class Simulator : public DecoderVisitor, public SimulatorBase {
   }
 
   int log_parameters_;
+  // Instruction counter only valid if FLAG_stop_sim_at isn't 0.
+  int icount_for_stop_sim_at_;
   Isolate* isolate_;
 };
 
diff --git a/deps/v8/src/execution/execution.cc b/deps/v8/src/execution/execution.cc
index 61219a21d7..e41c3a6286 100644
--- a/deps/v8/src/execution/execution.cc
+++ b/deps/v8/src/execution/execution.cc
@@ -229,12 +229,7 @@ MaybeHandle<Context> NewScriptContext(Isolate* isolate,
   Handle<Context> result =
       isolate->factory()->NewScriptContext(native_context, scope_info);
 
-  int header = scope_info->ContextHeaderLength();
-  for (int var = 0; var < scope_info->ContextLocalCount(); var++) {
-    if (scope_info->ContextLocalInitFlag(var) == kNeedsInitialization) {
-      result->set(header + var, ReadOnlyRoots(isolate).the_hole_value());
-    }
-  }
+  result->Initialize(isolate);
 
   Handle<ScriptContextTable> new_script_context_table =
       ScriptContextTable::Extend(script_context, result);
diff --git a/deps/v8/src/execution/frame-constants.h b/deps/v8/src/execution/frame-constants.h
index c215bbaeab..8c3f774319 100644
--- a/deps/v8/src/execution/frame-constants.h
+++ b/deps/v8/src/execution/frame-constants.h
@@ -21,6 +21,9 @@ namespace internal {
 // header, with slot index 2 corresponding to the current function context and 3
 // corresponding to the frame marker/JSFunction.
 //
+// If V8_REVERSE_JSARGS is set, then the parameters are reversed in the stack,
+// i.e., the first parameter (the receiver) is just above the return address.
+//
 //  slot      JS frame
 //       +-----------------+--------------------------------
 //  -n-1 |   parameter 0   |                            ^
@@ -160,7 +163,7 @@ class OptimizedBuiltinFrameConstants : public StandardFrameConstants {
   static constexpr int kFixedSlotCount = kFixedFrameSize / kSystemPointerSize;
 };
 
-// TypedFrames have a SMI type maker value below the saved FP/constant pool to
+// TypedFrames have a type maker value below the saved FP/constant pool to
 // distinguish them from StandardFrames, which have a context in that position
 // instead.
 //
@@ -202,8 +205,7 @@ class TypedFrameConstants : public CommonFrameConstants {
       StandardFrameConstants::kFixedFrameSizeAboveFp + kFixedFrameSizeFromFp;
   static constexpr int kFixedSlotCount = kFixedFrameSize / kSystemPointerSize;
   static constexpr int kFirstPushedFrameValueOffset =
-      -StandardFrameConstants::kCPSlotSize - kFrameTypeSize -
-      kSystemPointerSize;
+      -kFixedFrameSizeFromFp - kSystemPointerSize;
 };
 
 #define TYPED_FRAME_PUSHED_VALUE_OFFSET(x) \
@@ -326,8 +328,13 @@ class InterpreterFrameConstants : public AllStatic {
       StandardFrameConstants::kFixedFrameSizeFromFp + 2 * kSystemPointerSize;
 
   // FP-relative.
+#ifdef V8_REVERSE_JSARGS
+  static constexpr int kFirstParamFromFp =
+      StandardFrameConstants::kCallerSPOffset;
+#else
   static constexpr int kLastParamFromFp =
       StandardFrameConstants::kCallerSPOffset;
+#endif
   static constexpr int kCallerPCOffsetFromFp =
       StandardFrameConstants::kCallerPCOffset;
   static constexpr int kBytecodeArrayFromFp =
@@ -376,7 +383,7 @@ inline static int FrameSlotToFPOffset(int slot) {
 #include "src/execution/arm64/frame-constants-arm64.h"  // NOLINT
 #elif V8_TARGET_ARCH_ARM
 #include "src/execution/arm/frame-constants-arm.h"  // NOLINT
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/execution/ppc/frame-constants-ppc.h"  // NOLINT
 #elif V8_TARGET_ARCH_MIPS
 #include "src/execution/mips/frame-constants-mips.h"  // NOLINT
diff --git a/deps/v8/src/execution/frames-inl.h b/deps/v8/src/execution/frames-inl.h
index f1b979b7be..e73cca4f05 100644
--- a/deps/v8/src/execution/frames-inl.h
+++ b/deps/v8/src/execution/frames-inl.h
@@ -9,6 +9,7 @@
 #include "src/execution/frame-constants.h"
 #include "src/execution/frames.h"
 #include "src/execution/isolate.h"
+#include "src/execution/pointer-authentication.h"
 #include "src/objects/objects-inl.h"
 
 namespace v8 {
@@ -69,6 +70,16 @@ inline StackHandler* StackFrame::top_handler() const {
   return iterator_->handler();
 }
 
+inline Address StackFrame::callee_pc() const {
+  return state_.callee_pc_address ? ReadPC(state_.callee_pc_address)
+                                  : kNullAddress;
+}
+
+inline Address StackFrame::pc() const { return ReadPC(pc_address()); }
+
+inline Address StackFrame::ReadPC(Address* pc_address) {
+  return PointerAuthentication::AuthenticatePC(pc_address, kSystemPointerSize);
+}
 
 inline Address* StackFrame::ResolveReturnAddressLocation(Address* pc_address) {
   if (return_address_location_resolver_ == nullptr) {
@@ -179,11 +190,15 @@ inline JavaScriptFrame::JavaScriptFrame(StackFrameIteratorBase* iterator)
     : StandardFrame(iterator) {}
 
 Address JavaScriptFrame::GetParameterSlot(int index) const {
-  int param_count = ComputeParametersCount();
   DCHECK(-1 <= index &&
-         (index < param_count ||
-          param_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel));
+         (index < ComputeParametersCount() ||
+          ComputeParametersCount() == kDontAdaptArgumentsSentinel));
+#ifdef V8_REVERSE_JSARGS
+  int parameter_offset = (index + 1) * kSystemPointerSize;
+#else
+  int param_count = ComputeParametersCount();
   int parameter_offset = (param_count - index - 1) * kSystemPointerSize;
+#endif
   return caller_sp() + parameter_offset;
 }
 
@@ -231,6 +246,10 @@ inline WasmInterpreterEntryFrame::WasmInterpreterEntryFrame(
     StackFrameIteratorBase* iterator)
     : StandardFrame(iterator) {}
 
+inline WasmDebugBreakFrame::WasmDebugBreakFrame(
+    StackFrameIteratorBase* iterator)
+    : StandardFrame(iterator) {}
+
 inline WasmToJsFrame::WasmToJsFrame(StackFrameIteratorBase* iterator)
     : StubFrame(iterator) {}
 
diff --git a/deps/v8/src/execution/frames.cc b/deps/v8/src/execution/frames.cc
index 8337a63e17..7d405efa5e 100644
--- a/deps/v8/src/execution/frames.cc
+++ b/deps/v8/src/execution/frames.cc
@@ -491,16 +491,18 @@ Code StackFrame::LookupCode() const {
 
 void StackFrame::IteratePc(RootVisitor* v, Address* pc_address,
                            Address* constant_pool_address, Code holder) {
-  Address pc = *pc_address;
+  Address old_pc = ReadPC(pc_address);
   DCHECK(ReadOnlyHeap::Contains(holder) ||
-         holder.GetHeap()->GcSafeCodeContains(holder, pc));
-  unsigned pc_offset = static_cast<unsigned>(pc - holder.InstructionStart());
+         holder.GetHeap()->GcSafeCodeContains(holder, old_pc));
+  unsigned pc_offset =
+      static_cast<unsigned>(old_pc - holder.InstructionStart());
   Object code = holder;
   v->VisitRootPointer(Root::kTop, nullptr, FullObjectSlot(&code));
   if (code == holder) return;
   holder = Code::unchecked_cast(code);
-  pc = holder.InstructionStart() + pc_offset;
-  *pc_address = pc;
+  Address pc = holder.InstructionStart() + pc_offset;
+  // TODO(v8:10026): avoid replacing a signed pointer.
+  PointerAuthentication::ReplacePC(pc_address, pc, kSystemPointerSize);
   if (FLAG_enable_embedded_constant_pool && constant_pool_address) {
     *constant_pool_address = holder.constant_pool();
   }
@@ -521,6 +523,7 @@ StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
       kSystemPointerSize);
   intptr_t marker = Memory<intptr_t>(
       state->fp + CommonFrameConstants::kContextOrFrameTypeOffset);
+  Address pc = StackFrame::ReadPC(state->pc_address);
   if (!iterator->can_access_heap_objects_) {
     // TODO(titzer): "can_access_heap_objects" is kind of bogus. It really
     // means that we are being called from the profiler, which can interrupt
@@ -535,15 +538,13 @@ StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
     if (!StackFrame::IsTypeMarker(marker)) {
       if (maybe_function.IsSmi()) {
         return NATIVE;
-      } else if (IsInterpreterFramePc(iterator->isolate(), *(state->pc_address),
-                                      state)) {
+      } else if (IsInterpreterFramePc(iterator->isolate(), pc, state)) {
         return INTERPRETED;
       } else {
         return OPTIMIZED;
       }
     }
   } else {
-    Address pc = *(state->pc_address);
     // If the {pc} does not point into WebAssembly code we can rely on the
     // returned {wasm_code} to be null and fall back to {GetContainingCode}.
     wasm::WasmCodeRefScope code_ref_scope;
@@ -621,6 +622,7 @@ StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
     case WASM_COMPILED:
     case WASM_COMPILE_LAZY:
     case WASM_EXIT:
+    case WASM_DEBUG_BREAK:
       return candidate;
     case JS_TO_WASM:
     case OPTIMIZED:
@@ -894,6 +896,7 @@ void StandardFrame::ComputeCallerState(State* state) const {
   state->fp = caller_fp();
   state->pc_address = ResolveReturnAddressLocation(
       reinterpret_cast<Address*>(ComputePCAddress(fp())));
+  state->callee_fp = fp();
   state->callee_pc_address = pc_address();
   state->constant_pool_address =
       reinterpret_cast<Address*>(ComputeConstantPoolAddress(fp()));
@@ -967,6 +970,7 @@ void StandardFrame::IterateCompiledFrame(RootVisitor* v) const {
       case CONSTRUCT:
       case JS_TO_WASM:
       case C_WASM_ENTRY:
+      case WASM_DEBUG_BREAK:
         frame_header_size = TypedFrameConstants::kFixedFrameSizeFromFp;
         break;
       case WASM_TO_JS:
@@ -1667,6 +1671,7 @@ DeoptimizationData OptimizedFrame::GetDeoptimizationData(
   return DeoptimizationData();
 }
 
+#ifndef V8_REVERSE_JSARGS
 Object OptimizedFrame::receiver() const {
   Code code = LookupCode();
   if (code.kind() == Code::BUILTIN) {
@@ -1681,6 +1686,7 @@ Object OptimizedFrame::receiver() const {
     return JavaScriptFrame::receiver();
   }
 }
+#endif
 
 void OptimizedFrame::GetFunctions(
     std::vector<SharedFunctionInfo>* functions) const {
@@ -1779,7 +1785,7 @@ void InterpretedFrame::PatchBytecodeOffset(int new_offset) {
   DCHECK_EQ(InterpreterFrameConstants::kBytecodeOffsetFromFp,
             InterpreterFrameConstants::kExpressionsOffset -
                 index * kSystemPointerSize);
-  int raw_offset = new_offset + BytecodeArray::kHeaderSize - kHeapObjectTag;
+  int raw_offset = BytecodeArray::kHeaderSize - kHeapObjectTag + new_offset;
   SetExpression(index, Smi::FromInt(raw_offset));
 }
 
@@ -2028,6 +2034,26 @@ Address WasmInterpreterEntryFrame::GetCallerStackPointer() const {
   return fp() + ExitFrameConstants::kCallerSPOffset;
 }
 
+void WasmDebugBreakFrame::Iterate(RootVisitor* v) const {
+  // Nothing to iterate here. This will change once we support references in
+  // Liftoff.
+}
+
+Code WasmDebugBreakFrame::unchecked_code() const { return Code(); }
+
+void WasmDebugBreakFrame::Print(StringStream* accumulator, PrintMode mode,
+                                int index) const {
+  PrintIndex(accumulator, mode, index);
+  accumulator->Add("WASM DEBUG BREAK");
+  if (mode != OVERVIEW) accumulator->Add("\n");
+}
+
+Address WasmDebugBreakFrame::GetCallerStackPointer() const {
+  // WasmDebugBreak does not receive any arguments, hence the stack pointer of
+  // the caller is at a fixed offset from the frame pointer.
+  return fp() + WasmDebugBreakFrameConstants::kCallerSPOffset;
+}
+
 Code WasmCompileLazyFrame::unchecked_code() const { return Code(); }
 
 WasmInstanceObject WasmCompileLazyFrame::wasm_instance() const {
diff --git a/deps/v8/src/execution/frames.h b/deps/v8/src/execution/frames.h
index 3ffdee4b05..bd50cda8f8 100644
--- a/deps/v8/src/execution/frames.h
+++ b/deps/v8/src/execution/frames.h
@@ -70,6 +70,7 @@ class StackHandler {
   V(WASM_TO_JS, WasmToJsFrame)                                            \
   V(JS_TO_WASM, JsToWasmFrame)                                            \
   V(WASM_INTERPRETER_ENTRY, WasmInterpreterEntryFrame)                    \
+  V(WASM_DEBUG_BREAK, WasmDebugBreakFrame)                                \
   V(C_WASM_ENTRY, CWasmEntryFrame)                                        \
   V(WASM_EXIT, WasmExitFrame)                                             \
   V(WASM_COMPILE_LAZY, WasmCompileLazyFrame)                              \
@@ -117,6 +118,7 @@ class StackFrame {
     Address sp = kNullAddress;
     Address fp = kNullAddress;
     Address* pc_address = nullptr;
+    Address callee_fp = kNullAddress;
     Address* callee_pc_address = nullptr;
     Address* constant_pool_address = nullptr;
   };
@@ -181,6 +183,7 @@ class StackFrame {
   bool is_interpreted() const { return type() == INTERPRETED; }
   bool is_wasm_compiled() const { return type() == WASM_COMPILED; }
   bool is_wasm_compile_lazy() const { return type() == WASM_COMPILE_LAZY; }
+  bool is_wasm_debug_break() const { return type() == WASM_DEBUG_BREAK; }
   bool is_wasm_interpreter_entry() const {
     return type() == WASM_INTERPRETER_ENTRY;
   }
@@ -215,9 +218,8 @@ class StackFrame {
   // Accessors.
   Address sp() const { return state_.sp; }
   Address fp() const { return state_.fp; }
-  Address callee_pc() const {
-    return state_.callee_pc_address ? *state_.callee_pc_address : kNullAddress;
-  }
+  Address callee_fp() const { return state_.callee_fp; }
+  inline Address callee_pc() const;
   Address caller_sp() const { return GetCallerStackPointer(); }
 
   // If this frame is optimized and was dynamically aligned return its old
@@ -225,8 +227,7 @@ class StackFrame {
   // up one word and become unaligned.
   Address UnpaddedFP() const;
 
-  Address pc() const { return *pc_address(); }
-  void set_pc(Address pc) { *pc_address() = pc; }
+  inline Address pc() const;
 
   Address constant_pool() const { return *constant_pool_address(); }
   void set_constant_pool(Address constant_pool) {
@@ -265,6 +266,8 @@ class StackFrame {
   static void SetReturnAddressLocationResolver(
       ReturnAddressLocationResolver resolver);
 
+  static inline Address ReadPC(Address* pc_address);
+
   // Resolves pc_address through the resolution address function if one is set.
   static inline Address* ResolveReturnAddressLocation(Address* pc_address);
 
@@ -820,7 +823,11 @@ class OptimizedFrame : public JavaScriptFrame {
 
   DeoptimizationData GetDeoptimizationData(int* deopt_index) const;
 
+#ifndef V8_REVERSE_JSARGS
+  // When the arguments are reversed in the stack, receiver() is
+  // inherited from JavaScriptFrame.
   Object receiver() const override;
+#endif
   int ComputeParametersCount() const override;
 
   static int StackSlotOffsetRelativeToFp(int slot_index);
@@ -1027,6 +1034,32 @@ class WasmInterpreterEntryFrame final : public StandardFrame {
   WasmModuleObject module_object() const;
 };
 
+class WasmDebugBreakFrame final : public StandardFrame {
+ public:
+  Type type() const override { return WASM_DEBUG_BREAK; }
+
+  // GC support.
+  void Iterate(RootVisitor* v) const override;
+
+  Code unchecked_code() const override;
+
+  void Print(StringStream* accumulator, PrintMode mode,
+             int index) const override;
+
+  static WasmDebugBreakFrame* cast(StackFrame* frame) {
+    DCHECK(frame->is_wasm_debug_break());
+    return static_cast<WasmDebugBreakFrame*>(frame);
+  }
+
+ protected:
+  inline explicit WasmDebugBreakFrame(StackFrameIteratorBase*);
+
+  Address GetCallerStackPointer() const override;
+
+ private:
+  friend class StackFrameIteratorBase;
+};
+
 class WasmToJsFrame : public StubFrame {
  public:
   Type type() const override { return WASM_TO_JS; }
diff --git a/deps/v8/src/execution/futex-emulation.cc b/deps/v8/src/execution/futex-emulation.cc
index 8c3b54c2a7..9861454d8c 100644
--- a/deps/v8/src/execution/futex-emulation.cc
+++ b/deps/v8/src/execution/futex-emulation.cc
@@ -9,6 +9,7 @@
 #include "src/base/macros.h"
 #include "src/base/platform/time.h"
 #include "src/execution/isolate.h"
+#include "src/execution/vm-state-inl.h"
 #include "src/handles/handles-inl.h"
 #include "src/numbers/conversions.h"
 #include "src/objects/bigint.h"
@@ -105,27 +106,33 @@ Object WaitJsTranslateReturn(Isolate* isolate, Object res) {
 Object FutexEmulation::WaitJs32(Isolate* isolate,
                                 Handle<JSArrayBuffer> array_buffer, size_t addr,
                                 int32_t value, double rel_timeout_ms) {
-  Object res = Wait32(isolate, array_buffer, addr, value, rel_timeout_ms);
+  Object res =
+      Wait<int32_t>(isolate, array_buffer, addr, value, rel_timeout_ms);
   return WaitJsTranslateReturn(isolate, res);
 }
 
 Object FutexEmulation::WaitJs64(Isolate* isolate,
                                 Handle<JSArrayBuffer> array_buffer, size_t addr,
                                 int64_t value, double rel_timeout_ms) {
-  Object res = Wait64(isolate, array_buffer, addr, value, rel_timeout_ms);
+  Object res =
+      Wait<int64_t>(isolate, array_buffer, addr, value, rel_timeout_ms);
   return WaitJsTranslateReturn(isolate, res);
 }
 
-Object FutexEmulation::Wait32(Isolate* isolate,
-                              Handle<JSArrayBuffer> array_buffer, size_t addr,
-                              int32_t value, double rel_timeout_ms) {
-  return Wait<int32_t>(isolate, array_buffer, addr, value, rel_timeout_ms);
+Object FutexEmulation::WaitWasm32(Isolate* isolate,
+                                  Handle<JSArrayBuffer> array_buffer,
+                                  size_t addr, int32_t value,
+                                  int64_t rel_timeout_ns) {
+  return Wait<int32_t>(isolate, array_buffer, addr, value, rel_timeout_ns >= 0,
+                       rel_timeout_ns);
 }
 
-Object FutexEmulation::Wait64(Isolate* isolate,
-                              Handle<JSArrayBuffer> array_buffer, size_t addr,
-                              int64_t value, double rel_timeout_ms) {
-  return Wait<int64_t>(isolate, array_buffer, addr, value, rel_timeout_ms);
+Object FutexEmulation::WaitWasm64(Isolate* isolate,
+                                  Handle<JSArrayBuffer> array_buffer,
+                                  size_t addr, int64_t value,
+                                  int64_t rel_timeout_ns) {
+  return Wait<int64_t>(isolate, array_buffer, addr, value, rel_timeout_ns >= 0,
+                       rel_timeout_ns);
 }
 
 template <typename T>
@@ -135,24 +142,43 @@ Object FutexEmulation::Wait(Isolate* isolate,
   DCHECK_LT(addr, array_buffer->byte_length());
 
   bool use_timeout = rel_timeout_ms != V8_INFINITY;
+  int64_t rel_timeout_ns = -1;
 
-  base::TimeDelta rel_timeout;
   if (use_timeout) {
     // Convert to nanoseconds.
-    double rel_timeout_ns = rel_timeout_ms *
-                            base::Time::kNanosecondsPerMicrosecond *
-                            base::Time::kMicrosecondsPerMillisecond;
-    if (rel_timeout_ns >
-        static_cast<double>(std::numeric_limits<int64_t>::max())) {
+    double timeout_ns = rel_timeout_ms *
+                        base::Time::kNanosecondsPerMicrosecond *
+                        base::Time::kMicrosecondsPerMillisecond;
+    if (timeout_ns > static_cast<double>(std::numeric_limits<int64_t>::max())) {
       // 2**63 nanoseconds is 292 years. Let's just treat anything greater as
       // infinite.
       use_timeout = false;
     } else {
-      rel_timeout = base::TimeDelta::FromNanoseconds(
-          static_cast<int64_t>(rel_timeout_ns));
+      rel_timeout_ns = static_cast<int64_t>(timeout_ns);
     }
   }
+  return Wait(isolate, array_buffer, addr, value, use_timeout, rel_timeout_ns);
+}
+
+namespace {
+double WaitTimeoutInMs(double timeout_ns) {
+  return timeout_ns < 0
+             ? V8_INFINITY
+             : timeout_ns / (base::Time::kNanosecondsPerMicrosecond *
+                             base::Time::kMicrosecondsPerMillisecond);
+}
+}  // namespace
+
+template <typename T>
+Object FutexEmulation::Wait(Isolate* isolate,
+                            Handle<JSArrayBuffer> array_buffer, size_t addr,
+                            T value, bool use_timeout, int64_t rel_timeout_ns) {
+  VMState<ATOMICS_WAIT> state(isolate);
+  base::TimeDelta rel_timeout =
+      base::TimeDelta::FromNanoseconds(rel_timeout_ns);
 
+  // We have to convert the timeout back to double for the AtomicsWaitCallback.
+  double rel_timeout_ms = WaitTimeoutInMs(static_cast<double>(rel_timeout_ns));
   AtomicsWaitWakeHandle stop_handle(isolate);
 
   isolate->RunAtomicsWaitCallback(AtomicsWaitEvent::kStartWait, array_buffer,
diff --git a/deps/v8/src/execution/futex-emulation.h b/deps/v8/src/execution/futex-emulation.h
index 052b3c9c17..2d005bcfd1 100644
--- a/deps/v8/src/execution/futex-emulation.h
+++ b/deps/v8/src/execution/futex-emulation.h
@@ -126,13 +126,13 @@ class FutexEmulation : public AllStatic {
 
   // Same as WaitJs above except it returns 0 (ok), 1 (not equal) and 2 (timed
   // out) as expected by Wasm.
-  static Object Wait32(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
-                       size_t addr, int32_t value, double rel_timeout_ms);
+  static Object WaitWasm32(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
+                           size_t addr, int32_t value, int64_t rel_timeout_ns);
 
   // Same as Wait32 above except it checks for an int64_t value in the
   // array_buffer.
-  static Object Wait64(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
-                       size_t addr, int64_t value, double rel_timeout_ms);
+  static Object WaitWasm64(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
+                           size_t addr, int64_t value, int64_t rel_timeout_ns);
 
   // Wake |num_waiters_to_wake| threads that are waiting on the given |addr|.
   // |num_waiters_to_wake| can be kWakeAll, in which case all waiters are
@@ -154,6 +154,11 @@ class FutexEmulation : public AllStatic {
   static Object Wait(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
                      size_t addr, T value, double rel_timeout_ms);
 
+  template <typename T>
+  static Object Wait(Isolate* isolate, Handle<JSArrayBuffer> array_buffer,
+                     size_t addr, T value, bool use_timeout,
+                     int64_t rel_timeout_ns);
+
   // `mutex_` protects the composition of `wait_list_` (i.e. no elements may be
   // added or removed without holding this mutex), as well as the `waiting_`
   // and `interrupted_` fields for each individual list node that is currently
diff --git a/deps/v8/src/execution/ia32/frame-constants-ia32.h b/deps/v8/src/execution/ia32/frame-constants-ia32.h
index e579fa7352..dde0611f27 100644
--- a/deps/v8/src/execution/ia32/frame-constants-ia32.h
+++ b/deps/v8/src/execution/ia32/frame-constants-ia32.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_IA32_FRAME_CONSTANTS_IA32_H_
 #define V8_EXECUTION_IA32_FRAME_CONSTANTS_IA32_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -45,6 +46,42 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kSimd128Size;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {eax, ecx, edx, esi, edi}
+  static constexpr uint32_t kPushedGpRegs = 0b11000111;
+  // {xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6}
+  static constexpr uint32_t kPushedFpRegs = 0b01111111;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -kFixedFrameSizeFromFp - kNumPushedGpRegisters * kSystemPointerSize;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kNumPushedFpRegisters * kSimd128Size;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSimd128Size;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/isolate-data.h b/deps/v8/src/execution/isolate-data.h
index f402296ab5..2cbc3daa66 100644
--- a/deps/v8/src/execution/isolate-data.h
+++ b/deps/v8/src/execution/isolate-data.h
@@ -62,6 +62,14 @@ class IsolateData final {
     return kBuiltinsTableOffset - kIsolateRootBias;
   }
 
+  static constexpr int fast_c_call_caller_fp_offset() {
+    return kFastCCallCallerFPOffset - kIsolateRootBias;
+  }
+
+  static constexpr int fast_c_call_caller_pc_offset() {
+    return kFastCCallCallerPCOffset - kIsolateRootBias;
+  }
+
   // Root-register-relative offset of the given builtin table entry.
   // TODO(ishell): remove in favour of typified id version.
   static int builtin_slot_offset(int builtin_index) {
@@ -117,7 +125,7 @@ class IsolateData final {
   V(kEmbedderDataOffset, Internals::kNumIsolateDataSlots* kSystemPointerSize) \
   V(kExternalMemoryOffset, kInt64Size)                                        \
   V(kExternalMemoryLlimitOffset, kInt64Size)                                  \
-  V(kExternalMemoryAtLastMarkCompactOffset, kInt64Size)                       \
+  V(kExternalMemoryLowSinceMarkCompactOffset, kInt64Size)                     \
   V(kFastCCallCallerFPOffset, kSystemPointerSize)                             \
   V(kFastCCallCallerPCOffset, kSystemPointerSize)                             \
   V(kStackGuardOffset, StackGuard::kSizeInBytes)                              \
@@ -151,7 +159,7 @@ class IsolateData final {
   int64_t external_memory_limit_ = kExternalAllocationSoftLimit;
 
   // Caches the amount of external memory registered at the last MC.
-  int64_t external_memory_at_last_mark_compact_ = 0;
+  int64_t external_memory_low_since_mark_compact_ = 0;
 
   // Stores the state of the caller for TurboAssembler::CallCFunction so that
   // the sampling CPU profiler can iterate the stack during such calls. These
@@ -220,8 +228,9 @@ void IsolateData::AssertPredictableLayout() {
                 kExternalMemoryOffset);
   STATIC_ASSERT(offsetof(IsolateData, external_memory_limit_) ==
                 kExternalMemoryLlimitOffset);
-  STATIC_ASSERT(offsetof(IsolateData, external_memory_at_last_mark_compact_) ==
-                kExternalMemoryAtLastMarkCompactOffset);
+  STATIC_ASSERT(
+      offsetof(IsolateData, external_memory_low_since_mark_compact_) ==
+      kExternalMemoryLowSinceMarkCompactOffset);
   STATIC_ASSERT(offsetof(IsolateData, fast_c_call_caller_fp_) ==
                 kFastCCallCallerFPOffset);
   STATIC_ASSERT(offsetof(IsolateData, fast_c_call_caller_pc_) ==
diff --git a/deps/v8/src/execution/isolate-inl.h b/deps/v8/src/execution/isolate-inl.h
index ae786f00d5..163ab4ea8c 100644
--- a/deps/v8/src/execution/isolate-inl.h
+++ b/deps/v8/src/execution/isolate-inl.h
@@ -83,6 +83,18 @@ bool Isolate::is_catchable_by_javascript(Object exception) {
   return exception != ReadOnlyRoots(heap()).termination_exception();
 }
 
+bool Isolate::is_catchable_by_wasm(Object exception) {
+  if (!is_catchable_by_javascript(exception)) return false;
+  if (!exception.IsJSObject()) return true;
+  // We don't allocate, but the LookupIterator interface expects a handle.
+  DisallowHeapAllocation no_gc;
+  HandleScope handle_scope(this);
+  LookupIterator it(this, handle(JSReceiver::cast(exception), this),
+                    factory()->wasm_uncatchable_symbol(),
+                    LookupIterator::OWN_SKIP_INTERCEPTOR);
+  return !JSReceiver::HasProperty(&it).FromJust();
+}
+
 void Isolate::FireBeforeCallEnteredCallback() {
   for (auto& callback : before_call_entered_callbacks_) {
     callback(reinterpret_cast<v8::Isolate*>(this));
diff --git a/deps/v8/src/execution/isolate-utils-inl.h b/deps/v8/src/execution/isolate-utils-inl.h
index 16bc1da8fa..47e03d51a1 100644
--- a/deps/v8/src/execution/isolate-utils-inl.h
+++ b/deps/v8/src/execution/isolate-utils-inl.h
@@ -23,8 +23,15 @@ inline const Isolate* GetIsolateForPtrCompr(HeapObject object) {
 }
 
 V8_INLINE Heap* GetHeapFromWritableObject(HeapObject object) {
-#if defined V8_COMPRESS_POINTERS || defined V8_ENABLE_THIRD_PARTY_HEAP
-  return GetIsolateFromWritableObject(object)->heap();
+  // Avoid using the below GetIsolateFromWritableObject because we want to be
+  // able to get the heap, but not the isolate, for off-thread objects.
+
+#if defined V8_ENABLE_THIRD_PARTY_HEAP
+  return Heap::GetIsolateFromWritableObject(object)->heap();
+#elif defined V8_COMPRESS_POINTERS
+  Isolate* isolate = Isolate::FromRoot(GetIsolateRoot(object.ptr()));
+  DCHECK_NOT_NULL(isolate);
+  return isolate->heap();
 #else
   heap_internals::MemoryChunk* chunk =
       heap_internals::MemoryChunk::FromHeapObject(object);
@@ -33,6 +40,9 @@ V8_INLINE Heap* GetHeapFromWritableObject(HeapObject object) {
 }
 
 V8_INLINE Isolate* GetIsolateFromWritableObject(HeapObject object) {
+  // We don't want to allow accessing the isolate off-thread.
+  DCHECK(!Heap::InOffThreadSpace(object));
+
 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
   return Heap::GetIsolateFromWritableObject(object);
 #elif defined V8_COMPRESS_POINTERS
diff --git a/deps/v8/src/execution/isolate.cc b/deps/v8/src/execution/isolate.cc
index 3da8963c53..c9c6225eb8 100644
--- a/deps/v8/src/execution/isolate.cc
+++ b/deps/v8/src/execution/isolate.cc
@@ -10,7 +10,9 @@
 #include <fstream>  // NOLINT(readability/streams)
 #include <memory>
 #include <sstream>
+#include <string>
 #include <unordered_map>
+#include <utility>
 
 #include "src/api/api-inl.h"
 #include "src/ast/ast-value-factory.h"
@@ -968,13 +970,13 @@ Handle<Object> CaptureStackTrace(Isolate* isolate, Handle<Object> caller,
             builder.AppendJavaScriptFrame(java_script);
           } else if (summary.IsWasmCompiled()) {
             //=========================================================
-            // Handle a WASM compiled frame.
+            // Handle a Wasm compiled frame.
             //=========================================================
             auto const& wasm_compiled = summary.AsWasmCompiled();
             builder.AppendWasmCompiledFrame(wasm_compiled);
           } else if (summary.IsWasmInterpreted()) {
             //=========================================================
-            // Handle a WASM interpreted frame.
+            // Handle a Wasm interpreted frame.
             //=========================================================
             auto const& wasm_interpreted = summary.AsWasmInterpreted();
             builder.AppendWasmInterpretedFrame(wasm_interpreted);
@@ -1523,7 +1525,10 @@ Object Isolate::Throw(Object raw_exception, MessageLocation* location) {
 
   // Notify debugger of exception.
   if (is_catchable_by_javascript(raw_exception)) {
-    debug()->OnThrow(exception);
+    base::Optional<Object> maybe_exception = debug()->OnThrow(exception);
+    if (maybe_exception.has_value()) {
+      return *maybe_exception;
+    }
   }
 
   // Generate the message if required.
@@ -1609,6 +1614,7 @@ Object Isolate::UnwindAndFindHandler() {
   // Special handling of termination exceptions, uncatchable by JavaScript and
   // Wasm code, we unwind the handlers until the top ENTRY handler is found.
   bool catchable_by_js = is_catchable_by_javascript(exception);
+  bool catchable_by_wasm = is_catchable_by_wasm(exception);
 
   // Compute handler and stack unwinding information by performing a full walk
   // over the stack and dispatching according to the frame type.
@@ -1659,8 +1665,9 @@ Object Isolate::UnwindAndFindHandler() {
           trap_handler::ClearThreadInWasm();
         }
 
+        if (!catchable_by_wasm) break;
+
         // For WebAssembly frames we perform a lookup in the handler table.
-        if (!catchable_by_js) break;
         // This code ref scope is here to avoid a check failure when looking up
         // the code. It's not actually necessary to keep the code alive as it's
         // currently being executed.
@@ -2851,6 +2858,10 @@ Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator)
       builtins_(this),
       rail_mode_(PERFORMANCE_ANIMATION),
       code_event_dispatcher_(new CodeEventDispatcher()),
+      jitless_(FLAG_jitless),
+#if V8_SFI_HAS_UNIQUE_ID
+      next_unique_sfi_id_(0),
+#endif
       cancelable_task_manager_(new CancelableTaskManager()) {
   TRACE_ISOLATE(constructor);
   CheckIsolateLayout();
@@ -2900,10 +2911,10 @@ void Isolate::CheckIsolateLayout() {
   CHECK_EQ(static_cast<int>(
                OFFSET_OF(Isolate, isolate_data_.external_memory_limit_)),
            Internals::kExternalMemoryLimitOffset);
-  CHECK_EQ(Internals::kExternalMemoryAtLastMarkCompactOffset % 8, 0);
+  CHECK_EQ(Internals::kExternalMemoryLowSinceMarkCompactOffset % 8, 0);
   CHECK_EQ(static_cast<int>(OFFSET_OF(
-               Isolate, isolate_data_.external_memory_at_last_mark_compact_)),
-           Internals::kExternalMemoryAtLastMarkCompactOffset);
+               Isolate, isolate_data_.external_memory_low_since_mark_compact_)),
+           Internals::kExternalMemoryLowSinceMarkCompactOffset);
 }
 
 void Isolate::ClearSerializerData() {
@@ -2929,7 +2940,7 @@ void Isolate::Deinit() {
 
 #if defined(V8_OS_WIN64)
   if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
-      heap()->memory_allocator()) {
+      heap()->memory_allocator() && RequiresCodeRange()) {
     const base::AddressRegion& code_range =
         heap()->memory_allocator()->code_range();
     void* start = reinterpret_cast<void*>(code_range.begin());
@@ -3333,7 +3344,7 @@ bool Isolate::Init(ReadOnlyDeserializer* read_only_deserializer,
   has_fatal_error_ = false;
 
   // The initialization process does not handle memory exhaustion.
-  AlwaysAllocateScope always_allocate(this);
+  AlwaysAllocateScope always_allocate(heap());
 
 #define ASSIGN_ELEMENT(CamelName, hacker_name)                  \
   isolate_addresses_[IsolateAddressId::k##CamelName##Address] = \
@@ -3420,15 +3431,15 @@ bool Isolate::Init(ReadOnlyDeserializer* read_only_deserializer,
 
     setup_delegate_->SetupBuiltins(this);
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
     // Store the interpreter entry trampoline on the root list. It is used as a
     // template for further copies that may later be created to help profile
     // interpreted code.
-    // We currently cannot do this on arm due to RELATIVE_CODE_TARGETs
-    // assuming that all possible Code targets may be addressed with an int24
-    // offset, effectively limiting code space size to 32MB. We can guarantee
-    // this at mksnapshot-time, but not at runtime.
-    // See also: https://crbug.com/v8/8713.
+    // We currently cannot do this on above architectures due to
+    // RELATIVE_CODE_TARGETs assuming that all possible Code targets may be
+    // addressed with an int24 offset, effectively limiting code space size to
+    // 32MB. We can guarantee this at mksnapshot-time, but not at runtime. See
+    // also: https://crbug.com/v8/8713.
     heap_.SetInterpreterEntryTrampolineForProfiling(
         heap_.builtin(Builtins::kInterpreterEntryTrampoline));
 #endif
@@ -3462,8 +3473,8 @@ bool Isolate::Init(ReadOnlyDeserializer* read_only_deserializer,
 
   // If we are deserializing, read the state into the now-empty heap.
   {
-    AlwaysAllocateScope always_allocate(this);
-    CodeSpaceMemoryModificationScope modification_scope(&heap_);
+    AlwaysAllocateScope always_allocate(heap());
+    CodeSpaceMemoryModificationScope modification_scope(heap());
 
     if (create_heap_objects) {
       heap_.read_only_space()->ClearStringPaddingIfNeeded();
@@ -3503,11 +3514,11 @@ bool Isolate::Init(ReadOnlyDeserializer* read_only_deserializer,
   }
 #endif  // DEBUG
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
   // The IET for profiling should always be a full on-heap Code object.
   DCHECK(!Code::cast(heap_.interpreter_entry_trampoline_for_profiling())
               .is_off_heap_trampoline());
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
   if (FLAG_print_builtin_code) builtins()->PrintBuiltinCode();
   if (FLAG_print_builtin_size) builtins()->PrintBuiltinSize();
@@ -3696,6 +3707,11 @@ bool Isolate::use_optimizer() {
          !is_precise_count_code_coverage();
 }
 
+void Isolate::IncreaseTotalRegexpCodeGenerated(Handle<HeapObject> code) {
+  DCHECK(code->IsCode() || code->IsByteArray());
+  total_regexp_code_generated_ += code->Size();
+}
+
 bool Isolate::NeedsDetailedOptimizedCodeLineInfo() const {
   return NeedsSourcePositionsForProfiling() ||
          detailed_source_positions_for_profiling();
@@ -3752,18 +3768,21 @@ void Isolate::set_date_cache(DateCache* date_cache) {
   date_cache_ = date_cache;
 }
 
-bool Isolate::IsArrayOrObjectOrStringPrototype(Object object) {
+Isolate::KnownPrototype Isolate::IsArrayOrObjectOrStringPrototype(
+    Object object) {
   Object context = heap()->native_contexts_list();
   while (!context.IsUndefined(this)) {
     Context current_context = Context::cast(context);
-    if (current_context.initial_object_prototype() == object ||
-        current_context.initial_array_prototype() == object ||
-        current_context.initial_string_prototype() == object) {
-      return true;
+    if (current_context.initial_object_prototype() == object) {
+      return KnownPrototype::kObject;
+    } else if (current_context.initial_array_prototype() == object) {
+      return KnownPrototype::kArray;
+    } else if (current_context.initial_string_prototype() == object) {
+      return KnownPrototype::kString;
     }
     context = current_context.next_context_link();
   }
-  return false;
+  return KnownPrototype::kNone;
 }
 
 bool Isolate::IsInAnyContext(Object object, uint32_t index) {
@@ -3783,7 +3802,13 @@ void Isolate::UpdateNoElementsProtectorOnSetElement(Handle<JSObject> object) {
   DisallowHeapAllocation no_gc;
   if (!object->map().is_prototype_map()) return;
   if (!Protectors::IsNoElementsIntact(this)) return;
-  if (!IsArrayOrObjectOrStringPrototype(*object)) return;
+  KnownPrototype obj_type = IsArrayOrObjectOrStringPrototype(*object);
+  if (obj_type == KnownPrototype::kNone) return;
+  if (obj_type == KnownPrototype::kObject) {
+    this->CountUsage(v8::Isolate::kObjectPrototypeHasElements);
+  } else if (obj_type == KnownPrototype::kArray) {
+    this->CountUsage(v8::Isolate::kArrayPrototypeHasElements);
+  }
   Protectors::InvalidateNoElements(this);
 }
 
@@ -3909,18 +3934,15 @@ void Isolate::RemoveCallCompletedCallback(CallCompletedCallback callback) {
 void Isolate::FireCallCompletedCallback(MicrotaskQueue* microtask_queue) {
   if (!thread_local_top()->CallDepthIsZero()) return;
 
-  bool run_microtasks =
-      microtask_queue && microtask_queue->size() &&
-      !microtask_queue->HasMicrotasksSuppressions() &&
+  bool perform_checkpoint =
+      microtask_queue &&
       microtask_queue->microtasks_policy() == v8::MicrotasksPolicy::kAuto;
 
-  if (run_microtasks) {
-    microtask_queue->RunMicrotasks(this);
-  }
+  v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this);
+  if (perform_checkpoint) microtask_queue->PerformCheckpoint(isolate);
 
   if (call_completed_callbacks_.empty()) return;
   // Fire callbacks.  Increase call depth to prevent recursive callbacks.
-  v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this);
   v8::Isolate::SuppressMicrotaskExecutionScope suppress(isolate);
   std::vector<CallCompletedCallback> callbacks(call_completed_callbacks_);
   for (auto& callback : callbacks) {
@@ -4002,12 +4024,12 @@ void Isolate::SetHostCleanupFinalizationGroupCallback(
 }
 
 void Isolate::RunHostCleanupFinalizationGroupCallback(
-    Handle<JSFinalizationGroup> fg) {
+    Handle<JSFinalizationRegistry> fr) {
   if (host_cleanup_finalization_group_callback_ != nullptr) {
     v8::Local<v8::Context> api_context =
-        v8::Utils::ToLocal(handle(Context::cast(fg->native_context()), this));
+        v8::Utils::ToLocal(handle(Context::cast(fr->native_context()), this));
     host_cleanup_finalization_group_callback_(api_context,
-                                              v8::Utils::ToLocal(fg));
+                                              v8::Utils::ToLocal(fr));
   }
 }
 
@@ -4233,6 +4255,8 @@ void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature) {
   }
 }
 
+int Isolate::GetNextScriptId() { return heap()->NextScriptId(); }
+
 // static
 std::string Isolate::GetTurboCfgFileName(Isolate* isolate) {
   if (FLAG_trace_turbo_cfg_file == nullptr) {
@@ -4348,10 +4372,9 @@ void Isolate::PrintWithTimestamp(const char* format, ...) {
 }
 
 void Isolate::SetIdle(bool is_idle) {
-  if (!is_profiling()) return;
   StateTag state = current_vm_state();
-  DCHECK(state == EXTERNAL || state == IDLE);
   if (js_entry_sp() != kNullAddress) return;
+  DCHECK(state == EXTERNAL || state == IDLE);
   if (is_idle) {
     set_current_vm_state(IDLE);
   } else if (state == IDLE) {
@@ -4479,6 +4502,10 @@ void Isolate::AddCodeRange(Address begin, size_t length_in_bytes) {
       MemoryRange{reinterpret_cast<void*>(begin), length_in_bytes});
 }
 
+bool Isolate::RequiresCodeRange() const {
+  return kPlatformRequiresCodeRange && !jitless_;
+}
+
 // |chunk| is either a Page or an executable LargePage.
 void Isolate::RemoveCodeMemoryChunk(MemoryChunk* chunk) {
   // We only keep track of individual code pages/allocations if we are on arm32,
diff --git a/deps/v8/src/execution/isolate.h b/deps/v8/src/execution/isolate.h
index 913249dfe5..037e6ea7f5 100644
--- a/deps/v8/src/execution/isolate.h
+++ b/deps/v8/src/execution/isolate.h
@@ -204,7 +204,7 @@ class BuiltinUnwindInfo;
 
 #define ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, dst, call)                \
   do {                                                                        \
-    Isolate* __isolate__ = (isolate);                                         \
+    auto* __isolate__ = (isolate);                                            \
     ASSIGN_RETURN_ON_EXCEPTION_VALUE(__isolate__, dst, call,                  \
                                      ReadOnlyRoots(__isolate__).exception()); \
   } while (false)
@@ -212,21 +212,21 @@ class BuiltinUnwindInfo;
 #define ASSIGN_RETURN_ON_EXCEPTION(isolate, dst, call, T) \
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, dst, call, MaybeHandle<T>())
 
-#define THROW_NEW_ERROR(isolate, call, T)                       \
-  do {                                                          \
-    Isolate* __isolate__ = (isolate);                           \
-    return __isolate__->Throw<T>(__isolate__->factory()->call); \
+#define THROW_NEW_ERROR(isolate, call, T)                                \
+  do {                                                                   \
+    auto* __isolate__ = (isolate);                                       \
+    return __isolate__->template Throw<T>(__isolate__->factory()->call); \
   } while (false)
 
 #define THROW_NEW_ERROR_RETURN_FAILURE(isolate, call)         \
   do {                                                        \
-    Isolate* __isolate__ = (isolate);                         \
+    auto* __isolate__ = (isolate);                            \
     return __isolate__->Throw(*__isolate__->factory()->call); \
   } while (false)
 
 #define THROW_NEW_ERROR_RETURN_VALUE(isolate, call, value) \
   do {                                                     \
-    Isolate* __isolate__ = (isolate);                      \
+    auto* __isolate__ = (isolate);                         \
     __isolate__->Throw(*__isolate__->factory()->call);     \
     return value;                                          \
   } while (false)
@@ -437,7 +437,9 @@ using DebugObjectCache = std::vector<Handle<HeapObject>>;
   V(v8_inspector::V8Inspector*, inspector, nullptr)                            \
   V(bool, next_v8_call_is_safe_for_termination, false)                         \
   V(bool, only_terminate_in_safe_scope, false)                                 \
-  V(bool, detailed_source_positions_for_profiling, FLAG_detailed_line_info)
+  V(bool, detailed_source_positions_for_profiling, FLAG_detailed_line_info)    \
+  V(int, embedder_wrapper_type_index, -1)                                      \
+  V(int, embedder_wrapper_object_index, -1)
 
 #define THREAD_LOCAL_TOP_ACCESSOR(type, name)                         \
   inline void set_##name(type v) { thread_local_top()->name##_ = v; } \
@@ -450,13 +452,15 @@ using DebugObjectCache = std::vector<Handle<HeapObject>>;
 // Factory's members available to Isolate directly.
 class V8_EXPORT_PRIVATE HiddenFactory : private Factory {};
 
-class Isolate final : private HiddenFactory {
+class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
   // These forward declarations are required to make the friend declarations in
   // PerIsolateThreadData work on some older versions of gcc.
   class ThreadDataTable;
   class EntryStackItem;
 
  public:
+  using HandleScopeType = HandleScope;
+
   // A thread has a PerIsolateThreadData instance for each isolate that it has
   // entered. That instance is allocated when the isolate is initially entered
   // and reused on subsequent entries.
@@ -509,7 +513,7 @@ class Isolate final : private HiddenFactory {
 
   // Creates Isolate object. Must be used instead of constructing Isolate with
   // new operator.
-  static V8_EXPORT_PRIVATE Isolate* New(
+  static Isolate* New(
       IsolateAllocationMode mode = IsolateAllocationMode::kDefault);
 
   // Deletes Isolate object. Must be used instead of delete operator.
@@ -613,7 +617,7 @@ class Isolate final : private HiddenFactory {
   inline void set_pending_exception(Object exception_obj);
   inline void clear_pending_exception();
 
-  V8_EXPORT_PRIVATE bool AreWasmThreadsEnabled(Handle<Context> context);
+  bool AreWasmThreadsEnabled(Handle<Context> context);
 
   THREAD_LOCAL_TOP_ADDRESS(Object, pending_exception)
 
@@ -649,6 +653,7 @@ class Isolate final : private HiddenFactory {
   bool IsExternalHandlerOnTop(Object exception);
 
   inline bool is_catchable_by_javascript(Object exception);
+  inline bool is_catchable_by_wasm(Object exception);
 
   // JS execution stack (see frames.h).
   static Address c_entry_fp(ThreadLocalTop* thread) {
@@ -676,9 +681,9 @@ class Isolate final : private HiddenFactory {
     return &thread_local_top()->js_entry_sp_;
   }
 
-  V8_EXPORT_PRIVATE std::vector<MemoryRange>* GetCodePages() const;
+  std::vector<MemoryRange>* GetCodePages() const;
 
-  V8_EXPORT_PRIVATE void SetCodePages(std::vector<MemoryRange>* new_code_pages);
+  void SetCodePages(std::vector<MemoryRange>* new_code_pages);
 
   // Returns the global object of the current context. It could be
   // a builtin object, or a JS global object.
@@ -694,7 +699,7 @@ class Isolate final : private HiddenFactory {
   // exceptions.  If an exception was thrown and not handled by an external
   // handler the exception is scheduled to be rethrown when we return to running
   // JavaScript code.  If an exception is scheduled true is returned.
-  V8_EXPORT_PRIVATE bool OptionalRescheduleException(bool clear_exception);
+  bool OptionalRescheduleException(bool clear_exception);
 
   // Push and pop a promise and the current try-catch handler.
   void PushPromise(Handle<JSObject> promise);
@@ -719,7 +724,7 @@ class Isolate final : private HiddenFactory {
     Handle<Object> pending_exception_;
   };
 
-  V8_EXPORT_PRIVATE void SetCaptureStackTraceForUncaughtExceptions(
+  void SetCaptureStackTraceForUncaughtExceptions(
       bool capture, int frame_limit, StackTrace::StackTraceOptions options);
 
   void SetAbortOnUncaughtExceptionCallback(
@@ -729,8 +734,7 @@ class Isolate final : private HiddenFactory {
   void PrintCurrentStackTrace(FILE* out);
   void PrintStack(StringStream* accumulator,
                   PrintStackMode mode = kPrintStackVerbose);
-  V8_EXPORT_PRIVATE void PrintStack(FILE* out,
-                                    PrintStackMode mode = kPrintStackVerbose);
+  void PrintStack(FILE* out, PrintStackMode mode = kPrintStackVerbose);
   Handle<String> StackTraceString();
   // Stores a stack trace in a stack-allocated temporary buffer which will
   // end up in the minidump for debugging purposes.
@@ -774,6 +778,10 @@ class Isolate final : private HiddenFactory {
 
   void ThrowAt(Handle<JSObject> exception, MessageLocation* location);
 
+  void FatalProcessOutOfHeapMemory(const char* location) {
+    heap()->FatalProcessOutOfMemory(location);
+  }
+
   void set_console_delegate(debug::ConsoleDelegate* delegate) {
     console_delegate_ = delegate;
   }
@@ -807,7 +815,7 @@ class Isolate final : private HiddenFactory {
   };
   CatchType PredictExceptionCatcher();
 
-  V8_EXPORT_PRIVATE void ScheduleThrow(Object exception);
+  void ScheduleThrow(Object exception);
   // Re-set pending message, script and positions reported to the TryCatch
   // back to the TLS for re-use when rethrowing.
   void RestorePendingMessageFromTryCatch(v8::TryCatch* handler);
@@ -829,19 +837,18 @@ class Isolate final : private HiddenFactory {
   bool ComputeLocation(MessageLocation* target);
   bool ComputeLocationFromException(MessageLocation* target,
                                     Handle<Object> exception);
-  V8_EXPORT_PRIVATE bool ComputeLocationFromStackTrace(
-      MessageLocation* target, Handle<Object> exception);
+  bool ComputeLocationFromStackTrace(MessageLocation* target,
+                                     Handle<Object> exception);
 
-  V8_EXPORT_PRIVATE Handle<JSMessageObject> CreateMessage(
-      Handle<Object> exception, MessageLocation* location);
+  Handle<JSMessageObject> CreateMessage(Handle<Object> exception,
+                                        MessageLocation* location);
 
   // Out of resource exception helpers.
   Object StackOverflow();
   Object TerminateExecution();
   void CancelTerminateExecution();
 
-  V8_EXPORT_PRIVATE void RequestInterrupt(InterruptCallback callback,
-                                          void* data);
+  void RequestInterrupt(InterruptCallback callback, void* data);
   void InvokeApiInterruptCallbacks();
 
   // Administration
@@ -1034,9 +1041,7 @@ class Isolate final : private HiddenFactory {
   RegExpStack* regexp_stack() { return regexp_stack_; }
 
   size_t total_regexp_code_generated() { return total_regexp_code_generated_; }
-  void IncreaseTotalRegexpCodeGenerated(int size) {
-    total_regexp_code_generated_ += size;
-  }
+  void IncreaseTotalRegexpCodeGenerated(Handle<HeapObject> code);
 
   std::vector<int>* regexp_indices() { return &regexp_indices_; }
 
@@ -1085,13 +1090,13 @@ class Isolate final : private HiddenFactory {
   bool IsDead() { return has_fatal_error_; }
   void SignalFatalError() { has_fatal_error_ = true; }
 
-  V8_EXPORT_PRIVATE bool use_optimizer();
+  bool use_optimizer();
 
   bool initialized_from_snapshot() { return initialized_from_snapshot_; }
 
   bool NeedsSourcePositionsForProfiling() const;
 
-  V8_EXPORT_PRIVATE bool NeedsDetailedOptimizedCodeLineInfo() const;
+  bool NeedsDetailedOptimizedCodeLineInfo() const;
 
   bool is_best_effort_code_coverage() const {
     return code_coverage_mode() == debug::CoverageMode::kBestEffort;
@@ -1144,7 +1149,7 @@ class Isolate final : private HiddenFactory {
 
   DateCache* date_cache() { return date_cache_; }
 
-  V8_EXPORT_PRIVATE void set_date_cache(DateCache* date_cache);
+  void set_date_cache(DateCache* date_cache);
 
 #ifdef V8_INTL_SUPPORT
 
@@ -1169,7 +1174,9 @@ class Isolate final : private HiddenFactory {
 
 #endif  // V8_INTL_SUPPORT
 
-  bool IsArrayOrObjectOrStringPrototype(Object object);
+  enum class KnownPrototype { kNone, kObject, kArray, kString };
+
+  KnownPrototype IsArrayOrObjectOrStringPrototype(Object object);
 
   // On intent to set an element in object, make sure that appropriate
   // notifications occur if the set is on the elements of the array or
@@ -1214,7 +1221,7 @@ class Isolate final : private HiddenFactory {
   int id() const { return id_; }
 
   CompilationStatistics* GetTurboStatistics();
-  V8_EXPORT_PRIVATE CodeTracer* GetCodeTracer();
+  CodeTracer* GetCodeTracer();
 
   void DumpAndResetStats();
 
@@ -1228,16 +1235,16 @@ class Isolate final : private HiddenFactory {
     return &debug_execution_mode_;
   }
 
-  V8_EXPORT_PRIVATE base::RandomNumberGenerator* random_number_generator();
+  base::RandomNumberGenerator* random_number_generator();
 
-  V8_EXPORT_PRIVATE base::RandomNumberGenerator* fuzzer_rng();
+  base::RandomNumberGenerator* fuzzer_rng();
 
   // Generates a random number that is non-zero when masked
   // with the provided mask.
   int GenerateIdentityHash(uint32_t mask);
 
   // Given an address occupied by a live code object, return that object.
-  V8_EXPORT_PRIVATE Code FindCodeObject(Address a);
+  Code FindCodeObject(Address a);
 
   int NextOptimizationId() {
     int id = next_optimization_id_++;
@@ -1267,14 +1274,27 @@ class Isolate final : private HiddenFactory {
   Handle<Symbol> SymbolFor(RootIndex dictionary_index, Handle<String> name,
                            bool private_symbol);
 
-  V8_EXPORT_PRIVATE void SetUseCounterCallback(
-      v8::Isolate::UseCounterCallback callback);
+  void SetUseCounterCallback(v8::Isolate::UseCounterCallback callback);
   void CountUsage(v8::Isolate::UseCounterFeature feature);
 
   static std::string GetTurboCfgFileName(Isolate* isolate);
 
+  int GetNextScriptId();
+
 #if V8_SFI_HAS_UNIQUE_ID
-  int GetNextUniqueSharedFunctionInfoId() { return next_unique_sfi_id_++; }
+  int GetNextUniqueSharedFunctionInfoId() {
+    int current_id = next_unique_sfi_id_.load(std::memory_order_relaxed);
+    int next_id;
+    do {
+      if (current_id >= Smi::kMaxValue) {
+        next_id = 0;
+      } else {
+        next_id = current_id + 1;
+      }
+    } while (!next_unique_sfi_id_.compare_exchange_weak(
+        current_id, next_id, std::memory_order_relaxed));
+    return current_id;
+  }
 #endif
 
   Address promise_hook_address() {
@@ -1306,10 +1326,9 @@ class Isolate final : private HiddenFactory {
                               double timeout_in_ms,
                               AtomicsWaitWakeHandle* stop_handle);
 
-  V8_EXPORT_PRIVATE void SetPromiseHook(PromiseHook hook);
-  V8_EXPORT_PRIVATE void RunPromiseHook(PromiseHookType type,
-                                        Handle<JSPromise> promise,
-                                        Handle<Object> parent);
+  void SetPromiseHook(PromiseHook hook);
+  void RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
+                      Handle<Object> parent);
   void PromiseHookStateUpdated();
 
   void AddDetachedContext(Handle<Context> context);
@@ -1334,14 +1353,14 @@ class Isolate final : private HiddenFactory {
   // builtins constants table to remain unchanged from build-time.
   size_t HashIsolateForEmbeddedBlob();
 
-  V8_EXPORT_PRIVATE static const uint8_t* CurrentEmbeddedBlob();
-  V8_EXPORT_PRIVATE static uint32_t CurrentEmbeddedBlobSize();
+  static const uint8_t* CurrentEmbeddedBlob();
+  static uint32_t CurrentEmbeddedBlobSize();
   static bool CurrentEmbeddedBlobIsBinaryEmbedded();
 
   // These always return the same result as static methods above, but don't
   // access the global atomic variable (and thus *might be* slightly faster).
-  V8_EXPORT_PRIVATE const uint8_t* embedded_blob() const;
-  V8_EXPORT_PRIVATE uint32_t embedded_blob_size() const;
+  const uint8_t* embedded_blob() const;
+  uint32_t embedded_blob_size() const;
 
   void set_array_buffer_allocator(v8::ArrayBuffer::Allocator* allocator) {
     array_buffer_allocator_ = allocator;
@@ -1391,17 +1410,21 @@ class Isolate final : private HiddenFactory {
   void ClearKeptObjects();
   void SetHostCleanupFinalizationGroupCallback(
       HostCleanupFinalizationGroupCallback callback);
-  void RunHostCleanupFinalizationGroupCallback(Handle<JSFinalizationGroup> fg);
+  HostCleanupFinalizationGroupCallback
+  host_cleanup_finalization_group_callback() const {
+    return host_cleanup_finalization_group_callback_;
+  }
+  void RunHostCleanupFinalizationGroupCallback(
+      Handle<JSFinalizationRegistry> fr);
 
   void SetHostImportModuleDynamicallyCallback(
       HostImportModuleDynamicallyCallback callback);
-  V8_EXPORT_PRIVATE MaybeHandle<JSPromise>
-  RunHostImportModuleDynamicallyCallback(Handle<Script> referrer,
-                                         Handle<Object> specifier);
+  MaybeHandle<JSPromise> RunHostImportModuleDynamicallyCallback(
+      Handle<Script> referrer, Handle<Object> specifier);
 
   void SetHostInitializeImportMetaObjectCallback(
       HostInitializeImportMetaObjectCallback callback);
-  V8_EXPORT_PRIVATE Handle<JSObject> RunHostInitializeImportMetaObjectCallback(
+  Handle<JSObject> RunHostInitializeImportMetaObjectCallback(
       Handle<SourceTextModule> module);
 
   void RegisterEmbeddedFileWriter(EmbeddedFileWriterInterface* writer) {
@@ -1460,8 +1483,7 @@ class Isolate final : private HiddenFactory {
   bool allow_atomics_wait() { return allow_atomics_wait_; }
 
   // Register a finalizer to be called at isolate teardown.
-  V8_EXPORT_PRIVATE void RegisterManagedPtrDestructor(
-      ManagedPtrDestructor* finalizer);
+  void RegisterManagedPtrDestructor(ManagedPtrDestructor* finalizer);
 
   // Removes a previously-registered shared object finalizer.
   void UnregisterManagedPtrDestructor(ManagedPtrDestructor* finalizer);
@@ -1472,8 +1494,7 @@ class Isolate final : private HiddenFactory {
   }
 
   wasm::WasmEngine* wasm_engine() const { return wasm_engine_.get(); }
-  V8_EXPORT_PRIVATE void SetWasmEngine(
-      std::shared_ptr<wasm::WasmEngine> engine);
+  void SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine);
 
   const v8::Context::BackupIncumbentScope* top_backup_incumbent_scope() const {
     return top_backup_incumbent_scope_;
@@ -1483,23 +1504,25 @@ class Isolate final : private HiddenFactory {
     top_backup_incumbent_scope_ = top_backup_incumbent_scope;
   }
 
-  V8_EXPORT_PRIVATE void SetIdle(bool is_idle);
+  void SetIdle(bool is_idle);
 
   // Changing various modes can cause differences in generated bytecode which
   // interferes with lazy source positions, so this should be called immediately
   // before such a mode change to ensure that this cannot happen.
-  V8_EXPORT_PRIVATE void CollectSourcePositionsForAllBytecodeArrays();
+  void CollectSourcePositionsForAllBytecodeArrays();
 
   void AddCodeMemoryChunk(MemoryChunk* chunk);
   void RemoveCodeMemoryChunk(MemoryChunk* chunk);
-  V8_EXPORT_PRIVATE void AddCodeRange(Address begin, size_t length_in_bytes);
+  void AddCodeRange(Address begin, size_t length_in_bytes);
+
+  bool RequiresCodeRange() const;
 
  private:
   explicit Isolate(std::unique_ptr<IsolateAllocator> isolate_allocator);
   ~Isolate();
 
-  V8_EXPORT_PRIVATE bool Init(ReadOnlyDeserializer* read_only_deserializer,
-                              StartupDeserializer* startup_deserializer);
+  bool Init(ReadOnlyDeserializer* read_only_deserializer,
+            StartupDeserializer* startup_deserializer);
 
   void CheckIsolateLayout();
 
@@ -1696,7 +1719,7 @@ class Isolate final : private HiddenFactory {
   double time_millis_at_init_ = 0;
 
 #ifdef DEBUG
-  V8_EXPORT_PRIVATE static std::atomic<size_t> non_disposed_isolates_;
+  static std::atomic<size_t> non_disposed_isolates_;
 
   JSObject::SpillInformation js_spill_information_;
 #endif
@@ -1732,7 +1755,7 @@ class Isolate final : private HiddenFactory {
   // preprocessor defines. Make sure the offsets of these fields agree
   // between compilation units.
 #define ISOLATE_FIELD_OFFSET(type, name, ignored) \
-  V8_EXPORT_PRIVATE static const intptr_t name##_debug_offset_;
+  static const intptr_t name##_debug_offset_;
   ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
   ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
@@ -1746,10 +1769,12 @@ class Isolate final : private HiddenFactory {
 
   bool force_slow_path_ = false;
 
+  bool jitless_ = false;
+
   int next_optimization_id_ = 0;
 
 #if V8_SFI_HAS_UNIQUE_ID
-  int next_unique_sfi_id_ = 0;
+  std::atomic<int> next_unique_sfi_id_;
 #endif
 
   // Vector of callbacks before a Call starts execution.
diff --git a/deps/v8/src/execution/messages.cc b/deps/v8/src/execution/messages.cc
index f11ab23848..d1a76f654c 100644
--- a/deps/v8/src/execution/messages.cc
+++ b/deps/v8/src/execution/messages.cc
@@ -581,6 +581,12 @@ Handle<Object> WasmStackFrame::GetFunctionName() {
   return name;
 }
 
+Handle<Object> WasmStackFrame::GetScriptNameOrSourceUrl() {
+  Handle<Script> script = GetScript();
+  DCHECK_EQ(Script::TYPE_WASM, script->type());
+  return ScriptNameOrSourceUrl(script, isolate_);
+}
+
 Handle<Object> WasmStackFrame::GetWasmModuleName() {
   Handle<Object> module_name;
   Handle<WasmModuleObject> module_object(wasm_instance_->module_object(),
@@ -994,9 +1000,20 @@ MaybeHandle<JSObject> ErrorUtils::Construct(
     Isolate* isolate, Handle<JSFunction> target, Handle<Object> new_target,
     Handle<Object> message, FrameSkipMode mode, Handle<Object> caller,
     StackTraceCollection stack_trace_collection) {
+  if (FLAG_correctness_fuzzer_suppressions) {
+    // Abort range errors in correctness fuzzing, as their causes differ
+    // accross correctness-fuzzing scenarios.
+    if (target.is_identical_to(isolate->range_error_function())) {
+      FATAL("Aborting on range error");
+    }
+    // Ignore error messages in correctness fuzzing, because the spec leaves
+    // room for undefined behavior.
+    message = isolate->factory()->InternalizeUtf8String(
+        "Message suppressed for fuzzers (--correctness-fuzzer-suppressions)");
+  }
+
   // 1. If NewTarget is undefined, let newTarget be the active function object,
   // else let newTarget be NewTarget.
-
   Handle<JSReceiver> new_target_recv =
       new_target->IsJSReceiver() ? Handle<JSReceiver>::cast(new_target)
                                  : Handle<JSReceiver>::cast(target);
@@ -1154,15 +1171,7 @@ Handle<JSObject> ErrorUtils::MakeGenericError(
     // pending exceptions would be cleared. Preserve this behavior.
     isolate->clear_pending_exception();
   }
-  Handle<String> msg;
-  if (FLAG_correctness_fuzzer_suppressions) {
-    // Ignore error messages in correctness fuzzing, because the spec leaves
-    // room for undefined behavior.
-    msg = isolate->factory()->InternalizeUtf8String(
-        "Message suppressed for fuzzers (--correctness-fuzzer-suppressions)");
-  } else {
-    msg = DoFormatMessage(isolate, index, arg0, arg1, arg2);
-  }
+  Handle<String> msg = DoFormatMessage(isolate, index, arg0, arg1, arg2);
 
   DCHECK(mode != SKIP_UNTIL_SEEN);
 
@@ -1230,7 +1239,7 @@ Handle<String> RenderCallSite(Isolate* isolate, Handle<Object> object,
   if (ComputeLocation(isolate, location)) {
     ParseInfo info(isolate, *location->shared());
     if (parsing::ParseAny(&info, location->shared(), isolate)) {
-      info.ast_value_factory()->Internalize(isolate->factory());
+      info.ast_value_factory()->Internalize(isolate);
       CallPrinter printer(isolate, location->shared()->IsUserJavaScript());
       Handle<String> str = printer.Print(info.literal(), location->start_pos());
       *hint = printer.GetErrorHint();
@@ -1281,6 +1290,38 @@ Handle<Object> ErrorUtils::NewIteratorError(Isolate* isolate,
   return isolate->factory()->NewTypeError(id, callsite);
 }
 
+Object ErrorUtils::ThrowSpreadArgIsNullOrUndefinedError(Isolate* isolate,
+                                                        Handle<Object> object) {
+  MessageLocation location;
+  Handle<String> callsite;
+  if (ComputeLocation(isolate, &location)) {
+    ParseInfo info(isolate, *location.shared());
+    if (parsing::ParseAny(&info, location.shared(), isolate)) {
+      info.ast_value_factory()->Internalize(isolate);
+      CallPrinter printer(isolate, location.shared()->IsUserJavaScript(),
+                          CallPrinter::SpreadErrorInArgsHint::kErrorInArgs);
+      Handle<String> str = printer.Print(info.literal(), location.start_pos());
+      callsite =
+          str->length() > 0 ? str : BuildDefaultCallSite(isolate, object);
+
+      if (printer.spread_arg() != nullptr) {
+        // Change the message location to point at the property name.
+        int pos = printer.spread_arg()->position();
+        location =
+            MessageLocation(location.script(), pos, pos + 1, location.shared());
+      }
+    } else {
+      isolate->clear_pending_exception();
+      callsite = BuildDefaultCallSite(isolate, object);
+    }
+  }
+
+  MessageTemplate id = MessageTemplate::kNotIterableNoSymbolLoad;
+  Handle<Object> exception =
+      isolate->factory()->NewTypeError(id, callsite, object);
+  return isolate->Throw(*exception, &location);
+}
+
 Handle<Object> ErrorUtils::NewCalledNonCallableError(Isolate* isolate,
                                                      Handle<Object> source) {
   MessageLocation location;
@@ -1331,7 +1372,7 @@ Object ErrorUtils::ThrowLoadFromNullOrUndefined(Isolate* isolate,
 
     ParseInfo info(isolate, *location.shared());
     if (parsing::ParseAny(&info, location.shared(), isolate)) {
-      info.ast_value_factory()->Internalize(isolate->factory());
+      info.ast_value_factory()->Internalize(isolate);
       CallPrinter printer(isolate, location.shared()->IsUserJavaScript());
       Handle<String> str = printer.Print(info.literal(), location.start_pos());
 
@@ -1348,8 +1389,7 @@ Object ErrorUtils::ThrowLoadFromNullOrUndefined(Isolate* isolate,
           maybe_property_name = destructuring_prop->key()
                                     ->AsLiteral()
                                     ->AsRawPropertyName()
-                                    ->string()
-                                    .get<Factory>();
+                                    ->string();
           // Change the message location to point at the property name.
           pos = destructuring_prop->key()->position();
         }
diff --git a/deps/v8/src/execution/messages.h b/deps/v8/src/execution/messages.h
index cc6a233138..cf54cac852 100644
--- a/deps/v8/src/execution/messages.h
+++ b/deps/v8/src/execution/messages.h
@@ -169,7 +169,7 @@ class WasmStackFrame : public StackFrameBase {
 
   Handle<Object> GetFileName() override { return Null(); }
   Handle<Object> GetFunctionName() override;
-  Handle<Object> GetScriptNameOrSourceUrl() override { return Null(); }
+  Handle<Object> GetScriptNameOrSourceUrl() override;
   Handle<Object> GetMethodName() override { return Null(); }
   Handle<Object> GetTypeName() override { return Null(); }
   Handle<Object> GetWasmModuleName() override;
@@ -293,6 +293,8 @@ class ErrorUtils : public AllStatic {
                                                   Handle<Object> source);
   static Handle<Object> NewConstructedNonConstructable(Isolate* isolate,
                                                        Handle<Object> source);
+  static Object ThrowSpreadArgIsNullOrUndefinedError(Isolate* isolate,
+                                                     Handle<Object> object);
   static Object ThrowLoadFromNullOrUndefined(Isolate* isolate,
                                              Handle<Object> object);
   static Object ThrowLoadFromNullOrUndefined(Isolate* isolate,
diff --git a/deps/v8/src/execution/microtask-queue.cc b/deps/v8/src/execution/microtask-queue.cc
index fca9d2d3f4..496737b03a 100644
--- a/deps/v8/src/execution/microtask-queue.cc
+++ b/deps/v8/src/execution/microtask-queue.cc
@@ -115,6 +115,7 @@ void MicrotaskQueue::PerformCheckpoint(v8::Isolate* v8_isolate) {
       !HasMicrotasksSuppressions()) {
     Isolate* isolate = reinterpret_cast<Isolate*>(v8_isolate);
     RunMicrotasks(isolate);
+    isolate->ClearKeptObjects();
   }
 }
 
diff --git a/deps/v8/src/execution/mips/frame-constants-mips.h b/deps/v8/src/execution/mips/frame-constants-mips.h
index 08c9c789ac..6287203f95 100644
--- a/deps/v8/src/execution/mips/frame-constants-mips.h
+++ b/deps/v8/src/execution/mips/frame-constants-mips.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_MIPS_FRAME_CONSTANTS_MIPS_H_
 #define V8_EXECUTION_MIPS_FRAME_CONSTANTS_MIPS_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -36,6 +37,42 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {v0, v1, a0, a1, a2, a3, t0, t1, t2, t3, t4, t5, t6, s7}
+  static constexpr uint32_t kPushedGpRegs = 0b111111111111100 + (1 << 23);
+  // {f0, f2, f4, f6, f8, f10, f12, f14, f16, f18, f20, f22, f24}
+  static constexpr uint32_t kPushedFpRegs = 0b1010101010101010101010101;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -kFixedFrameSizeFromFp - kNumPushedGpRegisters * kSystemPointerSize;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kNumPushedFpRegisters * kDoubleSize;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/mips/simulator-mips.cc b/deps/v8/src/execution/mips/simulator-mips.cc
index 2d9a924c14..edb734d37c 100644
--- a/deps/v8/src/execution/mips/simulator-mips.cc
+++ b/deps/v8/src/execution/mips/simulator-mips.cc
@@ -465,7 +465,8 @@ void MipsDebugger::Debug() {
         } else {
           PrintF("printobject <value>\n");
         }
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         int32_t* cur = nullptr;
         int32_t* end = nullptr;
         int next_arg = 1;
@@ -505,20 +506,23 @@ void MipsDebugger::Debug() {
           end = cur + words;
         }
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%08" PRIxPTR ":  0x%08x %10d",
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
           Object obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
-          if (obj.IsSmi() ||
-              IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            if (obj.IsSmi()) {
-              PrintF("smi %d", Smi::ToInt(obj));
-            } else {
-              obj.ShortPrint();
+          if (!skip_obj_print) {
+            if (obj.IsSmi() ||
+                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              if (obj.IsSmi()) {
+                PrintF("smi %d", Smi::ToInt(obj));
+              } else {
+                obj.ShortPrint();
+              }
+              PrintF(")");
             }
-            PrintF(")");
           }
           PrintF("\n");
           cur++;
@@ -702,6 +706,10 @@ void MipsDebugger::Debug() {
         PrintF("  dump stack content, default dump 10 words)\n");
         PrintF("mem <address> [<words>]\n");
         PrintF("  dump memory content, default dump 10 words)\n");
+        PrintF("dump [<words>]\n");
+        PrintF(
+            "  dump memory content without pretty printing JS objects, default "
+            "dump 10 words)\n");
         PrintF("flags\n");
         PrintF("  print flags\n");
         PrintF("disasm [<instructions>]\n");
diff --git a/deps/v8/src/execution/mips64/frame-constants-mips64.h b/deps/v8/src/execution/mips64/frame-constants-mips64.h
index 58bb82a153..7a49ef6d19 100644
--- a/deps/v8/src/execution/mips64/frame-constants-mips64.h
+++ b/deps/v8/src/execution/mips64/frame-constants-mips64.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_MIPS64_FRAME_CONSTANTS_MIPS64_H_
 #define V8_EXECUTION_MIPS64_FRAME_CONSTANTS_MIPS64_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -32,6 +33,42 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {v0, v1, a0, a1, a2, a3, a4, a5, a6, a7, t0, t1, t2, s7}
+  static constexpr uint32_t kPushedGpRegs = 0b111111111111100 + (1 << 23);
+  // {f0, f2, f4, f6, f8, f10, f12, f14, f16, f18, f20, f22, f24, f26}
+  static constexpr uint32_t kPushedFpRegs = 0b101010101010101010101010101;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -kFixedFrameSizeFromFp - kNumPushedGpRegisters * kSystemPointerSize;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kNumPushedFpRegisters * kDoubleSize;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/mips64/simulator-mips64.cc b/deps/v8/src/execution/mips64/simulator-mips64.cc
index 78dbc29a0b..72f2836329 100644
--- a/deps/v8/src/execution/mips64/simulator-mips64.cc
+++ b/deps/v8/src/execution/mips64/simulator-mips64.cc
@@ -420,7 +420,8 @@ void MipsDebugger::Debug() {
         } else {
           PrintF("printobject <value>\n");
         }
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         int64_t* cur = nullptr;
         int64_t* end = nullptr;
         int next_arg = 1;
@@ -447,20 +448,23 @@ void MipsDebugger::Debug() {
         }
         end = cur + words;
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%012" PRIxPTR " :  0x%016" PRIx64 "  %14" PRId64 " ",
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
           Object obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
-          if (obj.IsSmi() ||
-              IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            if (obj.IsSmi()) {
-              PrintF("smi %d", Smi::ToInt(obj));
-            } else {
-              obj.ShortPrint();
+          if (!skip_obj_print) {
+            if (obj.IsSmi() ||
+                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              if (obj.IsSmi()) {
+                PrintF("smi %d", Smi::ToInt(obj));
+              } else {
+                obj.ShortPrint();
+              }
+              PrintF(")");
             }
-            PrintF(")");
           }
           PrintF("\n");
           cur++;
@@ -644,6 +648,10 @@ void MipsDebugger::Debug() {
         PrintF("  dump stack content, default dump 10 words)\n");
         PrintF("mem <address> [<words>]\n");
         PrintF("  dump memory content, default dump 10 words)\n");
+        PrintF("dump [<words>]\n");
+        PrintF(
+            "  dump memory content without pretty printing JS objects, default "
+            "dump 10 words)\n");
         PrintF("flags\n");
         PrintF("  print flags\n");
         PrintF("disasm [<instructions>]\n");
diff --git a/deps/v8/src/execution/off-thread-isolate.cc b/deps/v8/src/execution/off-thread-isolate.cc
new file mode 100644
index 0000000000..c08d51d7b4
--- /dev/null
+++ b/deps/v8/src/execution/off-thread-isolate.cc
@@ -0,0 +1,45 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/execution/off-thread-isolate.h"
+
+#include "src/execution/isolate.h"
+#include "src/execution/thread-id.h"
+#include "src/logging/off-thread-logger.h"
+
+namespace v8 {
+namespace internal {
+
+OffThreadIsolate::OffThreadIsolate(Isolate* isolate, Zone* zone)
+    : HiddenOffThreadFactory(isolate),
+      isolate_(isolate),
+      logger_(new OffThreadLogger()),
+      handle_zone_(zone) {}
+OffThreadIsolate::~OffThreadIsolate() { delete logger_; }
+
+int OffThreadIsolate::GetNextScriptId() { return isolate_->GetNextScriptId(); }
+
+#if V8_SFI_HAS_UNIQUE_ID
+int OffThreadIsolate::GetNextUniqueSharedFunctionInfoId() {
+  return isolate_->GetNextUniqueSharedFunctionInfoId();
+}
+#endif  // V8_SFI_HAS_UNIQUE_ID
+
+bool OffThreadIsolate::NeedsSourcePositionsForProfiling() {
+  // TODO(leszeks): Figure out if it makes sense to check this asynchronously.
+  return isolate_->NeedsSourcePositionsForProfiling();
+}
+
+bool OffThreadIsolate::is_collecting_type_profile() {
+  // TODO(leszeks): Figure out if it makes sense to check this asynchronously.
+  return isolate_->is_collecting_type_profile();
+}
+
+void OffThreadIsolate::PinToCurrentThread() {
+  DCHECK(!thread_id_.IsValid());
+  thread_id_ = ThreadId::Current();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/execution/off-thread-isolate.h b/deps/v8/src/execution/off-thread-isolate.h
new file mode 100644
index 0000000000..9a75c32859
--- /dev/null
+++ b/deps/v8/src/execution/off-thread-isolate.h
@@ -0,0 +1,99 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_EXECUTION_OFF_THREAD_ISOLATE_H_
+#define V8_EXECUTION_OFF_THREAD_ISOLATE_H_
+
+#include "src/base/logging.h"
+#include "src/execution/thread-id.h"
+#include "src/handles/handles.h"
+#include "src/heap/off-thread-factory.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+class OffThreadLogger;
+
+// HiddenOffThreadFactory parallels Isolate's HiddenFactory
+class V8_EXPORT_PRIVATE HiddenOffThreadFactory : private OffThreadFactory {
+ public:
+  // Forward constructors.
+  using OffThreadFactory::OffThreadFactory;
+};
+
+// And Isolate-like class that can be passed in to templated methods that need
+// an isolate syntactically, but are usable off-thread.
+//
+// This class holds an OffThreadFactory, but is otherwise effectively a stub
+// implementation of an Isolate. In particular, it doesn't allow throwing
+// exceptions, and hard crashes if you try.
+class V8_EXPORT_PRIVATE OffThreadIsolate final
+    : private HiddenOffThreadFactory {
+ public:
+  using HandleScopeType = OffThreadHandleScope;
+
+  explicit OffThreadIsolate(Isolate* isolate, Zone* zone);
+  ~OffThreadIsolate();
+
+  v8::internal::OffThreadFactory* factory() {
+    // Upcast to the privately inherited base-class using c-style casts to avoid
+    // undefined behavior (as static_cast cannot cast across private bases).
+    // NOLINTNEXTLINE (google-readability-casting)
+    return (
+        v8::internal::OffThreadFactory*)this;  // NOLINT(readability/casting)
+  }
+
+  // This method finishes the use of the off-thread Isolate, and can be safely
+  // called off-thread.
+  void FinishOffThread() {
+    factory()->FinishOffThread();
+    handle_zone_ = nullptr;
+  }
+
+  template <typename T>
+  Handle<T> Throw(Handle<Object> exception) {
+    UNREACHABLE();
+  }
+  [[noreturn]] void FatalProcessOutOfHeapMemory(const char* location) {
+    UNREACHABLE();
+  }
+
+  Address* NewHandle(Address object) {
+    DCHECK_NOT_NULL(handle_zone_);
+    Address* location =
+        static_cast<Address*>(handle_zone_->New(sizeof(Address)));
+    *location = object;
+    return location;
+  }
+
+  int GetNextScriptId();
+#if V8_SFI_HAS_UNIQUE_ID
+  int GetNextUniqueSharedFunctionInfoId();
+#endif  // V8_SFI_HAS_UNIQUE_ID
+
+  bool NeedsSourcePositionsForProfiling();
+  bool is_collecting_type_profile();
+
+  OffThreadLogger* logger() { return logger_; }
+
+  void PinToCurrentThread();
+  ThreadId thread_id() { return thread_id_; }
+
+ private:
+  friend class v8::internal::OffThreadFactory;
+
+  // TODO(leszeks): Extract out the fields of the Isolate we want and store
+  // those instead of the whole thing.
+  Isolate* isolate_;
+
+  OffThreadLogger* logger_;
+  ThreadId thread_id_;
+  Zone* handle_zone_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_EXECUTION_OFF_THREAD_ISOLATE_H_
diff --git a/deps/v8/src/execution/pointer-authentication-dummy.h b/deps/v8/src/execution/pointer-authentication-dummy.h
new file mode 100644
index 0000000000..32a10dc0dd
--- /dev/null
+++ b/deps/v8/src/execution/pointer-authentication-dummy.h
@@ -0,0 +1,56 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_EXECUTION_POINTER_AUTHENTICATION_DUMMY_H_
+#define V8_EXECUTION_POINTER_AUTHENTICATION_DUMMY_H_
+
+#include "src/execution/pointer-authentication.h"
+
+#include "include/v8.h"
+#include "src/base/macros.h"
+#include "src/common/globals.h"
+
+namespace v8 {
+namespace internal {
+
+// Dummy implementation of the PointerAuthentication class methods, to be used
+// when CFI is not enabled.
+
+// Load return address from {pc_address} and return it.
+V8_INLINE Address PointerAuthentication::AuthenticatePC(
+    Address* pc_address, unsigned offset_from_sp) {
+  USE(offset_from_sp);
+  return *pc_address;
+}
+
+// Return {pc} unmodified.
+V8_INLINE Address PointerAuthentication::StripPAC(Address pc) { return pc; }
+
+// Return {pc} unmodified.
+V8_INLINE Address PointerAuthentication::SignPCWithSP(Address pc, Address sp) {
+  USE(sp);
+  return pc;
+}
+
+// Store {new_pc} to {pc_address} without signing.
+V8_INLINE void PointerAuthentication::ReplacePC(Address* pc_address,
+                                                Address new_pc,
+                                                int offset_from_sp) {
+  USE(offset_from_sp);
+  *pc_address = new_pc;
+}
+
+// Do nothing.
+V8_INLINE void PointerAuthentication::ReplaceContext(Address* pc_address,
+                                                     Address old_context,
+                                                     Address new_context) {
+  USE(pc_address);
+  USE(old_context);
+  USE(new_context);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_EXECUTION_POINTER_AUTHENTICATION_DUMMY_H_
diff --git a/deps/v8/src/execution/pointer-authentication.h b/deps/v8/src/execution/pointer-authentication.h
new file mode 100644
index 0000000000..f2d63773f4
--- /dev/null
+++ b/deps/v8/src/execution/pointer-authentication.h
@@ -0,0 +1,65 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_EXECUTION_POINTER_AUTHENTICATION_H_
+#define V8_EXECUTION_POINTER_AUTHENTICATION_H_
+
+#include "include/v8.h"
+#include "src/base/macros.h"
+#include "src/common/globals.h"
+
+namespace v8 {
+namespace internal {
+
+class PointerAuthentication : public AllStatic {
+ public:
+  // When CFI is enabled, authenticate the address stored in {pc_address} and
+  // return the authenticated address. {offset_from_sp} is the offset between
+  // {pc_address} and the pointer used as a context for signing.
+  // When CFI is not enabled, simply load return address from {pc_address} and
+  // return it.
+  V8_INLINE static Address AuthenticatePC(Address* pc_address,
+                                          unsigned offset_from_sp);
+
+  // When CFI is enabled, strip Pointer Authentication Code (PAC) from {pc} and
+  // return the raw value.
+  // When CFI is not enabled, return {pc} unmodified.
+  V8_INLINE static Address StripPAC(Address pc);
+
+  // When CFI is enabled, sign {pc} using {sp} and return the signed value.
+  // When CFI is not enabled, return {pc} unmodified.
+  V8_INLINE static Address SignPCWithSP(Address pc, Address sp);
+
+  // When CFI is enabled, authenticate the address stored in {pc_address} and
+  // replace it with {new_pc}, after signing it. {offset_from_sp} is the offset
+  // between {pc_address} and the pointer used as a context for signing.
+  // When CFI is not enabled, store {new_pc} to {pc_address} without signing.
+  V8_INLINE static void ReplacePC(Address* pc_address, Address new_pc,
+                                  int offset_from_sp);
+
+  // When CFI is enabled, authenticate the address stored in {pc_address} based
+  // on {old_context} and replace it with the same address signed with
+  // {new_context} instead.
+  // When CFI is not enabled, do nothing.
+  V8_INLINE static void ReplaceContext(Address* pc_address, Address old_context,
+                                       Address new_context);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+
+#ifndef V8_TARGET_ARCH_ARM64
+#error "V8_ENABLE_CONTROL_FLOW_INTEGRITY should imply V8_TARGET_ARCH_ARM64"
+#endif
+#include "src/execution/arm64/pointer-authentication-arm64.h"
+
+#else
+
+#include "src/execution/pointer-authentication-dummy.h"
+
+#endif
+
+#endif  // V8_EXECUTION_POINTER_AUTHENTICATION_H_
diff --git a/deps/v8/src/execution/ppc/frame-constants-ppc.cc b/deps/v8/src/execution/ppc/frame-constants-ppc.cc
index 05cde9c8ee..97bef56a56 100644
--- a/deps/v8/src/execution/ppc/frame-constants-ppc.cc
+++ b/deps/v8/src/execution/ppc/frame-constants-ppc.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/execution/ppc/frame-constants-ppc.h"
 
@@ -32,4 +32,4 @@ int BuiltinContinuationFrameConstants::PaddingSlotCount(int register_count) {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  // V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/execution/ppc/frame-constants-ppc.h b/deps/v8/src/execution/ppc/frame-constants-ppc.h
index c987d48c27..47f3b9e410 100644
--- a/deps/v8/src/execution/ppc/frame-constants-ppc.h
+++ b/deps/v8/src/execution/ppc/frame-constants-ppc.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_PPC_FRAME_CONSTANTS_PPC_H_
 #define V8_EXECUTION_PPC_FRAME_CONSTANTS_PPC_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -30,6 +31,43 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {r3, r4, r5, r6, r7, r8, r9, r10, r11}
+  static constexpr uint32_t kPushedGpRegs = 0b111111111000;
+  // {d0 .. d12}
+  static constexpr uint32_t kPushedFpRegs = 0b1111111111111;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -TypedFrameConstants::kFixedFrameSizeFromFp -
+      kSystemPointerSize * kNumPushedGpRegisters;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kDoubleSize * kNumPushedFpRegisters;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/ppc/simulator-ppc.cc b/deps/v8/src/execution/ppc/simulator-ppc.cc
index ab8786713b..2a9aa6486b 100644
--- a/deps/v8/src/execution/ppc/simulator-ppc.cc
+++ b/deps/v8/src/execution/ppc/simulator-ppc.cc
@@ -19,6 +19,7 @@
 #include "src/diagnostics/disasm.h"
 #include "src/execution/ppc/frame-constants-ppc.h"
 #include "src/heap/combined-heap.h"
+#include "src/heap/heap-inl.h"  // For CodeSpaceMemoryModificationScope.
 #include "src/objects/objects-inl.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/utils/ostreams.h"
@@ -41,8 +42,6 @@ DEFINE_LAZY_LEAKY_OBJECT_GETTER(Simulator::GlobalMonitor,
 class PPCDebugger {
  public:
   explicit PPCDebugger(Simulator* sim) : sim_(sim) {}
-
-  void Stop(Instruction* instr);
   void Debug();
 
  private:
@@ -57,34 +56,20 @@ class PPCDebugger {
   bool GetValue(const char* desc, intptr_t* value);
   bool GetFPDoubleValue(const char* desc, double* value);
 
-  // Set or delete a breakpoint. Returns true if successful.
+  // Set or delete breakpoint (there can be only one).
   bool SetBreakpoint(Instruction* break_pc);
-  bool DeleteBreakpoint(Instruction* break_pc);
+  void DeleteBreakpoint();
 
-  // Undo and redo all breakpoints. This is needed to bracket disassembly and
-  // execution to skip past breakpoints when run from the debugger.
-  void UndoBreakpoints();
-  void RedoBreakpoints();
+  // Undo and redo the breakpoint. This is needed to bracket disassembly and
+  // execution to skip past the breakpoint when run from the debugger.
+  void UndoBreakpoint();
+  void RedoBreakpoint();
 };
 
-void PPCDebugger::Stop(Instruction* instr) {
-  // Get the stop code.
-  // use of kStopCodeMask not right on PowerPC
-  uint32_t code = instr->SvcValue() & kStopCodeMask;
-  // Retrieve the encoded address, which comes just after this stop.
-  char* msg = *reinterpret_cast<char**>(sim_->get_pc() + kInstrSize);
-  // Update this stop description.
-  if (sim_->isWatchedStop(code) && !sim_->watched_stops_[code].desc) {
-    sim_->watched_stops_[code].desc = msg;
-  }
-  // Print the stop message and code if it is not the default code.
-  if (code != kMaxStopCode) {
-    PrintF("Simulator hit stop %u: %s\n", code, msg);
-  } else {
-    PrintF("Simulator hit %s\n", msg);
-  }
-  sim_->set_pc(sim_->get_pc() + kInstrSize + kPointerSize);
-  Debug();
+void Simulator::DebugAtNextPC() {
+  PrintF("Starting debugger on the next instruction:\n");
+  set_pc(get_pc() + kInstrSize);
+  PPCDebugger(this).Debug();
 }
 
 intptr_t PPCDebugger::GetRegisterValue(int regnum) {
@@ -139,25 +124,33 @@ bool PPCDebugger::SetBreakpoint(Instruction* break_pc) {
   return true;
 }
 
-bool PPCDebugger::DeleteBreakpoint(Instruction* break_pc) {
-  if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
-  }
+namespace {
+// This function is dangerous, but it's only available in non-production
+// (simulator) builds.
+void SetInstructionBitsInCodeSpace(Instruction* instr, Instr value,
+                                   Heap* heap) {
+  CodeSpaceMemoryModificationScope scope(heap);
+  instr->SetInstructionBits(value);
+}
+}  // namespace
 
+void PPCDebugger::DeleteBreakpoint() {
+  UndoBreakpoint();
   sim_->break_pc_ = nullptr;
   sim_->break_instr_ = 0;
-  return true;
 }
 
-void PPCDebugger::UndoBreakpoints() {
+void PPCDebugger::UndoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, sim_->break_instr_,
+                                  sim_->isolate_->heap());
   }
 }
 
-void PPCDebugger::RedoBreakpoints() {
+void PPCDebugger::RedoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(kBreakpointInstr);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, kBreakpointInstr,
+                                  sim_->isolate_->heap());
   }
 }
 
@@ -181,9 +174,9 @@ void PPCDebugger::Debug() {
   arg1[ARG_SIZE] = 0;
   arg2[ARG_SIZE] = 0;
 
-  // Undo all set breakpoints while running in the debugger shell. This will
-  // make them invisible to all commands.
-  UndoBreakpoints();
+  // Unset breakpoint while running in the debugger shell, making it invisible
+  // to all commands.
+  UndoBreakpoint();
   // Disable tracing while simulating
   bool trace = ::v8::internal::FLAG_trace_sim;
   ::v8::internal::FLAG_trace_sim = false;
@@ -361,7 +354,8 @@ void PPCDebugger::Debug() {
           continue;
         }
         sim_->set_pc(value);
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         intptr_t* cur = nullptr;
         intptr_t* end = nullptr;
         int next_arg = 1;
@@ -388,20 +382,23 @@ void PPCDebugger::Debug() {
         }
         end = cur + words;
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%08" V8PRIxPTR ":  0x%08" V8PRIxPTR " %10" V8PRIdPTR,
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
           Object obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
-          if (obj.IsSmi() ||
-              IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            if (obj.IsSmi()) {
-              PrintF("smi %d", Smi::ToInt(obj));
-            } else {
-              obj.ShortPrint();
+          if (!skip_obj_print) {
+            if (obj.IsSmi() ||
+                IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              if (obj.IsSmi()) {
+                PrintF("smi %d", Smi::ToInt(obj));
+              } else {
+                obj.ShortPrint();
+              }
+              PrintF(")");
             }
-            PrintF(")");
           }
           PrintF("\n");
           cur++;
@@ -471,9 +468,7 @@ void PPCDebugger::Debug() {
           PrintF("break <address>\n");
         }
       } else if (strcmp(cmd, "del") == 0) {
-        if (!DeleteBreakpoint(nullptr)) {
-          PrintF("deleting breakpoint failed\n");
-        }
+        DeleteBreakpoint();
       } else if (strcmp(cmd, "cr") == 0) {
         PrintF("Condition reg: %08x\n", sim_->condition_reg_);
       } else if (strcmp(cmd, "lr") == 0) {
@@ -493,7 +488,8 @@ void PPCDebugger::Debug() {
         if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
           // Remove the current stop.
           if (sim_->isStopInstruction(stop_instr)) {
-            stop_instr->SetInstructionBits(kNopInstr);
+            SetInstructionBitsInCodeSpace(stop_instr, kNopInstr,
+                                          sim_->isolate_->heap());
             msg_address->SetInstructionBits(kNopInstr);
           } else {
             PrintF("Not at debugger stop.\n");
@@ -573,6 +569,10 @@ void PPCDebugger::Debug() {
         PrintF("  dump stack content, default dump 10 words)\n");
         PrintF("mem <address> [<num words>]\n");
         PrintF("  dump memory content, default dump 10 words)\n");
+        PrintF("dump [<words>]\n");
+        PrintF(
+            "  dump memory content without pretty printing JS objects, default "
+            "dump 10 words)\n");
         PrintF("disasm [<instructions>]\n");
         PrintF("disasm [<address/register>]\n");
         PrintF("disasm [[<address/register>] <instructions>]\n");
@@ -613,9 +613,9 @@ void PPCDebugger::Debug() {
     }
   }
 
-  // Add all the breakpoints back to stop execution and enter the debugger
-  // shell when hit.
-  RedoBreakpoints();
+  // Reinstall breakpoint to stop execution and enter the debugger shell when
+  // hit.
+  RedoBreakpoint();
   // Restore tracing
   ::v8::internal::FLAG_trace_sim = trace;
 
@@ -1210,13 +1210,11 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       set_pc(saved_lr);
       break;
     }
-    case kBreakpoint: {
-      PPCDebugger dbg(this);
-      dbg.Debug();
+    case kBreakpoint:
+      PPCDebugger(this).Debug();
       break;
-    }
     // stop uses all codes greater than 1 << 23.
-    default: {
+    default:
       if (svc >= (1 << 23)) {
         uint32_t code = svc & kStopCodeMask;
         if (isWatchedStop(code)) {
@@ -1225,17 +1223,19 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         // Stop if it is enabled, otherwise go on jumping over the stop
         // and the message address.
         if (isEnabledStop(code)) {
-          PPCDebugger dbg(this);
-          dbg.Stop(instr);
+          if (code != kMaxStopCode) {
+            PrintF("Simulator hit stop %u. ", code);
+          } else {
+            PrintF("Simulator hit stop. ");
+          }
+          DebugAtNextPC();
         } else {
           set_pc(get_pc() + kInstrSize + kPointerSize);
         }
       } else {
         // This is not a valid svc code.
         UNREACHABLE();
-        break;
       }
-    }
   }
 }
 
diff --git a/deps/v8/src/execution/ppc/simulator-ppc.h b/deps/v8/src/execution/ppc/simulator-ppc.h
index 34a39f608b..76f836b196 100644
--- a/deps/v8/src/execution/ppc/simulator-ppc.h
+++ b/deps/v8/src/execution/ppc/simulator-ppc.h
@@ -238,6 +238,7 @@ class Simulator : public SimulatorBase {
   void HandleRList(Instruction* instr, bool load);
   void HandleVList(Instruction* inst);
   void SoftwareInterrupt(Instruction* instr);
+  void DebugAtNextPC();
 
   // Stop helper functions.
   inline bool isStopInstruction(Instruction* instr);
diff --git a/deps/v8/src/execution/runtime-profiler.cc b/deps/v8/src/execution/runtime-profiler.cc
index c1bdf021eb..7459f59ae1 100644
--- a/deps/v8/src/execution/runtime-profiler.cc
+++ b/deps/v8/src/execution/runtime-profiler.cc
@@ -9,6 +9,7 @@
 #include "src/codegen/compilation-cache.h"
 #include "src/codegen/compiler.h"
 #include "src/codegen/pending-optimization-table.h"
+#include "src/diagnostics/code-tracer.h"
 #include "src/execution/execution.h"
 #include "src/execution/frames-inl.h"
 #include "src/handles/global-handles.h"
@@ -69,18 +70,20 @@ RuntimeProfiler::RuntimeProfiler(Isolate* isolate)
     : isolate_(isolate), any_ic_changed_(false) {}
 
 static void TraceRecompile(JSFunction function, const char* reason,
-                           const char* type) {
+                           const char* type, Isolate* isolate) {
   if (FLAG_trace_opt) {
-    PrintF("[marking ");
-    function.ShortPrint();
-    PrintF(" for %s recompilation, reason: %s", type, reason);
-    PrintF("]\n");
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    PrintF(scope.file(), "[marking ");
+    function.ShortPrint(scope.file());
+    PrintF(scope.file(), " for %s recompilation, reason: %s", type, reason);
+    PrintF(scope.file(), "]\n");
   }
 }
 
 void RuntimeProfiler::Optimize(JSFunction function, OptimizationReason reason) {
   DCHECK_NE(reason, OptimizationReason::kDoNotOptimize);
-  TraceRecompile(function, OptimizationReasonToString(reason), "optimized");
+  TraceRecompile(function, OptimizationReasonToString(reason), "optimized",
+                 isolate_);
   function.MarkForOptimization(ConcurrencyMode::kConcurrent);
 }
 
@@ -99,9 +102,10 @@ void RuntimeProfiler::AttemptOnStackReplacement(InterpretedFrame* frame,
   // BytecodeArray header so that certain back edges in any interpreter frame
   // for this bytecode will trigger on-stack replacement for that frame.
   if (FLAG_trace_osr) {
-    PrintF("[OSR - arming back edges in ");
-    function.PrintName();
-    PrintF("]\n");
+    CodeTracer::Scope scope(isolate_->GetCodeTracer());
+    PrintF(scope.file(), "[OSR - arming back edges in ");
+    function.PrintName(scope.file());
+    PrintF(scope.file(), "]\n");
   }
 
   DCHECK_EQ(StackFrame::INTERPRETED, frame->type());
diff --git a/deps/v8/src/execution/s390/frame-constants-s390.h b/deps/v8/src/execution/s390/frame-constants-s390.h
index efa03f6e01..0893fffedf 100644
--- a/deps/v8/src/execution/s390/frame-constants-s390.h
+++ b/deps/v8/src/execution/s390/frame-constants-s390.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_S390_FRAME_CONSTANTS_S390_H_
 #define V8_EXECUTION_S390_FRAME_CONSTANTS_S390_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -36,6 +37,43 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kDoubleSize;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {r2, r3, r4, r5, r6, r7, r8}
+  static constexpr uint32_t kPushedGpRegs = 0b111111100;
+  // {d0 .. d12}
+  static constexpr uint32_t kPushedFpRegs = 0b1111111111111;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -TypedFrameConstants::kFixedFrameSizeFromFp -
+      kSystemPointerSize * kNumPushedGpRegisters;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kDoubleSize * kNumPushedFpRegisters;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kDoubleSize;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/execution/s390/simulator-s390.cc b/deps/v8/src/execution/s390/simulator-s390.cc
index 985a941874..f41288f6a9 100644
--- a/deps/v8/src/execution/s390/simulator-s390.cc
+++ b/deps/v8/src/execution/s390/simulator-s390.cc
@@ -19,6 +19,7 @@
 #include "src/codegen/s390/constants-s390.h"
 #include "src/diagnostics/disasm.h"
 #include "src/heap/combined-heap.h"
+#include "src/heap/heap-inl.h"  // For CodeSpaceMemoryModificationScope.
 #include "src/objects/objects-inl.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/utils/ostreams.h"
@@ -39,8 +40,6 @@ const Simulator::fpr_t Simulator::fp_zero;
 class S390Debugger {
  public:
   explicit S390Debugger(Simulator* sim) : sim_(sim) {}
-
-  void Stop(Instruction* instr);
   void Debug();
 
  private:
@@ -61,34 +60,20 @@ class S390Debugger {
   bool GetValue(const char* desc, intptr_t* value);
   bool GetFPDoubleValue(const char* desc, double* value);
 
-  // Set or delete a breakpoint. Returns true if successful.
-  bool SetBreakpoint(Instruction* break_pc);
-  bool DeleteBreakpoint(Instruction* break_pc);
+  // Set or delete breakpoint (there can be only one).
+  bool SetBreakpoint(Instruction* breakpc);
+  void DeleteBreakpoint();
 
-  // Undo and redo all breakpoints. This is needed to bracket disassembly and
-  // execution to skip past breakpoints when run from the debugger.
-  void UndoBreakpoints();
-  void RedoBreakpoints();
+  // Undo and redo the breakpoint. This is needed to bracket disassembly and
+  // execution to skip past the breakpoint when run from the debugger.
+  void UndoBreakpoint();
+  void RedoBreakpoint();
 };
 
-void S390Debugger::Stop(Instruction* instr) {
-  // Get the stop code.
-  // use of kStopCodeMask not right on PowerPC
-  uint32_t code = instr->SvcValue() & kStopCodeMask;
-  // Retrieve the encoded address, which comes just after this stop.
-  char* msg = *reinterpret_cast<char**>(sim_->get_pc() + sizeof(FourByteInstr));
-  // Update this stop description.
-  if (sim_->isWatchedStop(code) && !sim_->watched_stops_[code].desc) {
-    sim_->watched_stops_[code].desc = msg;
-  }
-  // Print the stop message and code if it is not the default code.
-  if (code != kMaxStopCode) {
-    PrintF("Simulator hit stop %u: %s\n", code, msg);
-  } else {
-    PrintF("Simulator hit %s\n", msg);
-  }
-  sim_->set_pc(sim_->get_pc() + sizeof(FourByteInstr) + kPointerSize);
-  Debug();
+void Simulator::DebugAtNextPC() {
+  PrintF("Starting debugger on the next instruction:\n");
+  set_pc(get_pc() + sizeof(FourByteInstr));
+  S390Debugger(this).Debug();
 }
 
 intptr_t S390Debugger::GetRegisterValue(int regnum) {
@@ -147,25 +132,33 @@ bool S390Debugger::SetBreakpoint(Instruction* break_pc) {
   return true;
 }
 
-bool S390Debugger::DeleteBreakpoint(Instruction* break_pc) {
-  if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
-  }
+namespace {
+// This function is dangerous, but it's only available in non-production
+// (simulator) builds.
+void SetInstructionBitsInCodeSpace(Instruction* instr, Instr value,
+                                   Heap* heap) {
+  CodeSpaceMemoryModificationScope scope(heap);
+  instr->SetInstructionBits(value);
+}
+}  // namespace
 
+void S390Debugger::DeleteBreakpoint() {
+  UndoBreakpoint();
   sim_->break_pc_ = nullptr;
   sim_->break_instr_ = 0;
-  return true;
 }
 
-void S390Debugger::UndoBreakpoints() {
+void S390Debugger::UndoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, sim_->break_instr_,
+                                  sim_->isolate_->heap());
   }
 }
 
-void S390Debugger::RedoBreakpoints() {
+void S390Debugger::RedoBreakpoint() {
   if (sim_->break_pc_ != nullptr) {
-    sim_->break_pc_->SetInstructionBits(kBreakpointInstr);
+    SetInstructionBitsInCodeSpace(sim_->break_pc_, kBreakpointInstr,
+                                  sim_->isolate_->heap());
   }
 }
 
@@ -189,9 +182,9 @@ void S390Debugger::Debug() {
   arg1[ARG_SIZE] = 0;
   arg2[ARG_SIZE] = 0;
 
-  // Undo all set breakpoints while running in the debugger shell. This will
-  // make them invisible to all commands.
-  UndoBreakpoints();
+  // Unset breakpoint while running in the debugger shell, making it invisible
+  // to all commands.
+  UndoBreakpoint();
   // Disable tracing while simulating
   bool trace = ::v8::internal::FLAG_trace_sim;
   ::v8::internal::FLAG_trace_sim = false;
@@ -391,7 +384,8 @@ void S390Debugger::Debug() {
           continue;
         }
         sim_->set_pc(value);
-      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
+      } else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0 ||
+                 strcmp(cmd, "dump") == 0) {
         intptr_t* cur = nullptr;
         intptr_t* end = nullptr;
         int next_arg = 1;
@@ -418,19 +412,22 @@ void S390Debugger::Debug() {
         }
         end = cur + words;
 
+        bool skip_obj_print = (strcmp(cmd, "dump") == 0);
         while (cur < end) {
           PrintF("  0x%08" V8PRIxPTR ":  0x%08" V8PRIxPTR " %10" V8PRIdPTR,
                  reinterpret_cast<intptr_t>(cur), *cur, *cur);
           Object obj(*cur);
           Heap* current_heap = sim_->isolate_->heap();
-          if (obj.IsSmi()) {
-            PrintF(" (smi %d)", Smi::ToInt(obj));
-          } else if (IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
-            PrintF(" (");
-            obj.ShortPrint();
-            PrintF(")");
+          if (!skip_obj_print) {
+            if (obj.IsSmi()) {
+              PrintF(" (smi %d)", Smi::ToInt(obj));
+            } else if (IsValidHeapObject(current_heap, HeapObject::cast(obj))) {
+              PrintF(" (");
+              obj.ShortPrint();
+              PrintF(")");
+            }
+            PrintF("\n");
           }
-          PrintF("\n");
           cur++;
         }
       } else if (strcmp(cmd, "disasm") == 0 || strcmp(cmd, "di") == 0) {
@@ -498,22 +495,21 @@ void S390Debugger::Debug() {
           PrintF("break <address>\n");
         }
       } else if (strcmp(cmd, "del") == 0) {
-        if (!DeleteBreakpoint(nullptr)) {
-          PrintF("deleting breakpoint failed\n");
-        }
+        DeleteBreakpoint();
       } else if (strcmp(cmd, "cr") == 0) {
         PrintF("Condition reg: %08x\n", sim_->condition_reg_);
       } else if (strcmp(cmd, "stop") == 0) {
         intptr_t value;
         intptr_t stop_pc =
-            sim_->get_pc() - (sizeof(FourByteInstr) + kPointerSize);
+            sim_->get_pc() - (sizeof(FourByteInstr) + kSystemPointerSize);
         Instruction* stop_instr = reinterpret_cast<Instruction*>(stop_pc);
         Instruction* msg_address =
             reinterpret_cast<Instruction*>(stop_pc + sizeof(FourByteInstr));
         if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
           // Remove the current stop.
           if (sim_->isStopInstruction(stop_instr)) {
-            stop_instr->SetInstructionBits(kNopInstr);
+            SetInstructionBitsInCodeSpace(stop_instr, kNopInstr,
+                                          sim_->isolate_->heap());
             msg_address->SetInstructionBits(kNopInstr);
           } else {
             PrintF("Not at debugger stop.\n");
@@ -587,6 +583,10 @@ void S390Debugger::Debug() {
         PrintF("  dump stack content, default dump 10 words)\n");
         PrintF("mem <address> [<num words>]\n");
         PrintF("  dump memory content, default dump 10 words)\n");
+        PrintF("dump [<words>]\n");
+        PrintF(
+            "  dump memory content without pretty printing JS objects, default "
+            "dump 10 words)\n");
         PrintF("disasm [<instructions>]\n");
         PrintF("disasm [<address/register>]\n");
         PrintF("disasm [[<address/register>] <instructions>]\n");
@@ -627,9 +627,9 @@ void S390Debugger::Debug() {
     }
   }
 
-  // Add all the breakpoints back to stop execution and enter the debugger
-  // shell when hit.
-  RedoBreakpoints();
+  // Reinstall breakpoint to stop execution and enter the debugger shell when
+  // hit.
+  RedoBreakpoint();
   // Restore tracing
   ::v8::internal::FLAG_trace_sim = trace;
 
@@ -747,17 +747,21 @@ void Simulator::EvalTableInit() {
 #define S390_SUPPORTED_VECTOR_OPCODE_LIST(V)                                   \
   V(vst, VST, 0xE70E)     /* type = VRX   VECTOR STORE  */                     \
   V(vl, VL, 0xE706)       /* type = VRX   VECTOR LOAD  */                      \
+  V(vlp, VLP, 0xE7DF)     /* type = VRR_A VECTOR LOAD POSITIVE */              \
   V(vlgv, VLGV, 0xE721)   /* type = VRS_C VECTOR LOAD GR FROM VR ELEMENT  */   \
   V(vlvg, VLVG, 0xE722)   /* type = VRS_B VECTOR LOAD VR ELEMENT FROM GR  */   \
+  V(vlvgp, VLVGP, 0xE762) /* type = VRR_F VECTOR LOAD VR FROM GRS DISJOINT */  \
   V(vrep, VREP, 0xE74D)   /* type = VRI_C VECTOR REPLICATE  */                 \
   V(vlrep, VLREP, 0xE705) /* type = VRX   VECTOR LOAD AND REPLICATE  */        \
   V(vrepi, VREPI, 0xE745) /* type = VRI_A VECTOR REPLICATE IMMEDIATE  */       \
   V(vlr, VLR, 0xE756)     /* type = VRR_A VECTOR LOAD  */                      \
   V(vstef, VSTEF, 0xE70B) /* type = VRX   VECTOR STORE ELEMENT (32)  */        \
   V(vlef, VLEF, 0xE703)   /* type = VRX   VECTOR LOAD ELEMENT (32)  */         \
+  V(vavgl, VAVGL, 0xE7F0) /* type = VRR_C VECTOR AVERAGE LOGICAL  */           \
   V(va, VA, 0xE7F3)       /* type = VRR_C VECTOR ADD  */                       \
   V(vs, VS, 0xE7F7)       /* type = VRR_C VECTOR SUBTRACT  */                  \
   V(vml, VML, 0xE7A2)     /* type = VRR_C VECTOR MULTIPLY LOW  */              \
+  V(vnc, VNC, 0xE769)     /* type = VRR_C VECTOR AND WITH COMPLEMENT */        \
   V(vsum, VSUM, 0xE764)   /* type = VRR_C VECTOR SUM ACROSS WORD  */           \
   V(vsumg, VSUMG, 0xE765) /* type = VRR_C VECTOR SUM ACROSS DOUBLEWORD  */     \
   V(vpk, VPK, 0xE794)     /* type = VRR_C VECTOR PACK  */                      \
@@ -777,14 +781,21 @@ void Simulator::EvalTableInit() {
   V(vch, VCH, 0xE7FB)     /* type = VRR_B VECTOR COMPARE HIGH  */              \
   V(vo, VO, 0xE76A)       /* type = VRR_C VECTOR OR  */                        \
   V(vn, VN, 0xE768)       /* type = VRR_C VECTOR AND  */                       \
+  V(vno, VNO, 0xE768B)    /* type = VRR_C VECTOR NOR  */                       \
   V(vlc, VLC, 0xE7DE)     /* type = VRR_A VECTOR LOAD COMPLEMENT  */           \
   V(vsel, VSEL, 0xE78D)   /* type = VRR_E VECTOR SELECT  */                    \
+  V(vperm, VPERM, 0xE78C) /* type = VRR_E VECTOR PERMUTE  */                   \
   V(vtm, VTM, 0xE7D8)     /* type = VRR_A VECTOR TEST UNDER MASK  */           \
   V(vesl, VESL, 0xE730)   /* type = VRS_A VECTOR ELEMENT SHIFT LEFT  */        \
+  V(veslv, VESLV, 0xE770) /* type = VRR_C VECTOR ELEMENT SHIFT LEFT  */        \
   V(vesrl, VESRL,                                                              \
     0xE738) /* type = VRS_A VECTOR ELEMENT SHIFT RIGHT LOGICAL  */             \
+  V(vesrlv, VESRLV,                                                            \
+    0xE778) /* type = VRR_C VECTOR ELEMENT SHIFT RIGHT LOGICAL  */             \
   V(vesra, VESRA,                                                              \
     0xE73A) /* type = VRS_A VECTOR ELEMENT SHIFT RIGHT ARITHMETIC  */          \
+  V(vesrav, VESRAV,                                                            \
+    0xE77A) /* type = VRR_C VECTOR ELEMENT SHIFT RIGHT ARITHMETIC  */          \
   V(vfsq, VFSQ, 0xE7CE)   /* type = VRR_A VECTOR FP SQUARE ROOT  */            \
   V(vfmax, VFMAX, 0xE7EF) /* type = VRR_C VECTOR FP MAXIMUM */                 \
   V(vfmin, VFMIN, 0xE7EE) /* type = VRR_C VECTOR FP MINIMUM */                 \
@@ -796,7 +807,10 @@ void Simulator::EvalTableInit() {
   V(vfs, VFS, 0xE7E2)     /* type = VRR_C VECTOR FP SUBTRACT  */               \
   V(vfa, VFA, 0xE7E3)     /* type = VRR_C VECTOR FP ADD  */                    \
   V(vfd, VFD, 0xE7E5)     /* type = VRR_C VECTOR FP DIVIDE  */                 \
-  V(vfm, VFM, 0xE7E7)     /* type = VRR_C VECTOR FP MULTIPLY  */
+  V(vfm, VFM, 0xE7E7)     /* type = VRR_C VECTOR FP MULTIPLY  */               \
+  V(vfma, VFMA, 0xE78F)   /* type = VRR_E VECTOR FP MULTIPLY AND ADD  */       \
+  V(vfnms, VFNMS,                                                              \
+    0xE79E) /* type = VRR_E VECTOR FP NEGATIVE MULTIPLY AND SUBTRACT   */
 
 #define CREATE_EVALUATE_TABLE(name, op_name, op_value) \
   EvalTable[op_name] = &Simulator::Evaluate_##op_name;
@@ -1912,8 +1926,9 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       // Remaining arguments on stack
       intptr_t* stack_pointer = reinterpret_cast<intptr_t*>(get_register(sp));
       for (int i = kRegisterArgCount; i < kArgCount; i++) {
-        arg[i] = stack_pointer[(kCalleeRegisterSaveAreaSize / kPointerSize) +
-                               (i - kRegisterArgCount)];
+        arg[i] =
+            stack_pointer[(kCalleeRegisterSaveAreaSize / kSystemPointerSize) +
+                          (i - kRegisterArgCount)];
       }
       STATIC_ASSERT(kArgCount == kRegisterArgCount + 5);
       STATIC_ASSERT(kMaxCParameters == kArgCount);
@@ -1925,7 +1940,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
 
       // Place the return address on the stack, making the call GC safe.
       *reinterpret_cast<intptr_t*>(get_register(sp) +
-                                   kStackFrameRASlot * kPointerSize) =
+                                   kStackFrameRASlot * kSystemPointerSize) =
           get_register(r14);
 
       intptr_t external =
@@ -2193,7 +2208,7 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         // #endif
       }
       int64_t saved_lr = *reinterpret_cast<intptr_t*>(
-          get_register(sp) + kStackFrameRASlot * kPointerSize);
+          get_register(sp) + kStackFrameRASlot * kSystemPointerSize);
 #if (!V8_TARGET_ARCH_S390X && V8_HOST_ARCH_S390)
       // On zLinux-31, the saved_lr might be tagged with a high bit of 1.
       // Cleanse it before proceeding with simulation.
@@ -2202,13 +2217,11 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       set_pc(saved_lr);
       break;
     }
-    case kBreakpoint: {
-      S390Debugger dbg(this);
-      dbg.Debug();
+    case kBreakpoint:
+      S390Debugger(this).Debug();
       break;
-    }
     // stop uses all codes greater than 1 << 23.
-    default: {
+    default:
       if (svc >= (1 << 23)) {
         uint32_t code = svc & kStopCodeMask;
         if (isWatchedStop(code)) {
@@ -2217,17 +2230,19 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
         // Stop if it is enabled, otherwise go on jumping over the stop
         // and the message address.
         if (isEnabledStop(code)) {
-          S390Debugger dbg(this);
-          dbg.Stop(instr);
+          if (code != kMaxStopCode) {
+            PrintF("Simulator hit stop %u. ", code);
+          } else {
+            PrintF("Simulator hit stop. ");
+          }
+          DebugAtNextPC();
         } else {
-          set_pc(get_pc() + sizeof(FourByteInstr) + kPointerSize);
+          set_pc(get_pc() + sizeof(FourByteInstr) + kSystemPointerSize);
         }
       } else {
         // This is not a valid svc code.
         UNREACHABLE();
-        break;
       }
-    }
   }
 }
 
@@ -2870,6 +2885,12 @@ uintptr_t Simulator::PopAddress() {
   int m5 = AS(VRR_E_Instruction)->M5Value();             \
   int length = 6;
 
+#define DECODE_VRR_F_INSTRUCTION(r1, r2, r3) \
+  int r1 = AS(VRR_F_Instruction)->R1Value(); \
+  int r2 = AS(VRR_F_Instruction)->R2Value(); \
+  int r3 = AS(VRR_F_Instruction)->R3Value(); \
+  int length = 6;
+
 #define DECODE_VRX_INSTRUCTION(r1, x2, b2, d2, m3) \
   int r1 = AS(VRX_Instruction)->R1Value();         \
   int x2 = AS(VRX_Instruction)->X2Value();         \
@@ -2927,6 +2948,78 @@ EVALUATE(VL) {
   return length;
 }
 
+#define VECTOR_LOAD_POSITIVE(r1, r2, type)                              \
+  for (size_t i = 0, j = 0; j < kSimd128Size; i++, j += sizeof(type)) { \
+    set_simd_register_by_lane<type>(                                    \
+        r1, i, abs(get_simd_register_by_lane<type>(r2, i)));            \
+  }
+EVALUATE(VLP) {
+  DCHECK(VL);
+  DECODE_VRR_A_INSTRUCTION(r1, r2, m5, m4, m3);
+  USE(m5);
+  USE(m4);
+  switch (m3) {
+    case 0: {
+      VECTOR_LOAD_POSITIVE(r1, r2, int8_t)
+      break;
+    }
+    case 1: {
+      VECTOR_LOAD_POSITIVE(r1, r2, int16_t)
+      break;
+    }
+    case 2: {
+      VECTOR_LOAD_POSITIVE(r1, r2, int32_t)
+      break;
+    }
+    case 3: {
+      VECTOR_LOAD_POSITIVE(r1, r2, int64_t)
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+
+  return length;
+}
+#undef VECTOR_LOAD_POSITIVE
+
+#define VECTOR_AVERAGE_U(r1, r2, r3, type)                                    \
+  for (size_t i = 0, j = 0; j < kSimd128Size; i++, j += sizeof(type)) {       \
+    type src0 = get_simd_register_by_lane<type>(r2, i);                       \
+    type src1 = get_simd_register_by_lane<type>(r3, i);                       \
+    set_simd_register_by_lane<type>(                                          \
+        r1, i, (static_cast<type>(src0) + static_cast<type>(src1) + 1) >> 1); \
+  }
+EVALUATE(VAVGL) {
+  DCHECK(VL);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  switch (m4) {
+    case 0: {
+      VECTOR_AVERAGE_U(r1, r2, r3, uint8_t)
+      break;
+    }
+    case 1: {
+      VECTOR_AVERAGE_U(r1, r2, r3, uint16_t)
+      break;
+    }
+    case 2: {
+      VECTOR_AVERAGE_U(r1, r2, r3, uint32_t)
+      break;
+    }
+    case 3: {
+      VECTOR_AVERAGE_U(r1, r2, r3, uint64_t)
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+
+  return length;
+}
+#undef VECTOR_AVERAGE_U
+
 EVALUATE(VLGV) {
   DCHECK_OPCODE(VLGV);
   DECODE_VRS_INSTRUCTION(r1, r3, b2, d2, m4);
@@ -2950,6 +3043,14 @@ EVALUATE(VLVG) {
   return length;
 }
 
+EVALUATE(VLVGP) {
+  DCHECK_OPCODE(VLVGP);
+  DECODE_VRR_F_INSTRUCTION(r1, r2, r3);
+  set_simd_register_by_lane<int64_t>(r1, 0, get_register(r2));
+  set_simd_register_by_lane<int64_t>(r1, 1, get_register(r3));
+  return length;
+}
+
 EVALUATE(VREP) {
   DCHECK_OPCODE(VREP);
   DECODE_VRI_C_INSTRUCTION(r1, r3, i2, m4);
@@ -3084,6 +3185,20 @@ EVALUATE(VML) {
   return length;
 }
 
+EVALUATE(VNC) {
+  DCHECK(VNC);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  USE(m4);
+  for (int i = 0; i < 2; i++) {
+    int64_t lane_1 = get_simd_register_by_lane<uint64_t>(r2, i);
+    int64_t lane_2 = get_simd_register_by_lane<uint64_t>(r3, i);
+    set_simd_register_by_lane<uint64_t>(r1, i, lane_1 & ~lane_2);
+  }
+  return length;
+}
+
 template <class S, class D>
 void VectorSum(void* dst, void* src1, void* src2) {
   D value = 0;
@@ -3490,6 +3605,42 @@ EVALUATE(VX) {
   return length;
 }
 
+#define VECTOR_NOR(r1, r2, r3, type)                                    \
+  for (size_t i = 0, j = 0; j < kSimd128Size; i++, j += sizeof(type)) { \
+    type src0 = get_simd_register_by_lane<type>(r2, i);                 \
+    type src1 = get_simd_register_by_lane<type>(r3, i);                 \
+    set_simd_register_by_lane<type>(r1, i, ~(src0 | src1));             \
+  }
+EVALUATE(VNO) {
+  DCHECK(VL);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  switch (m4) {
+    case 0: {
+      VECTOR_NOR(r1, r2, r3, int8_t)
+      break;
+    }
+    case 1: {
+      VECTOR_NOR(r1, r2, r3, int16_t)
+      break;
+    }
+    case 2: {
+      VECTOR_NOR(r1, r2, r3, int32_t)
+      break;
+    }
+    case 3: {
+      VECTOR_NOR(r1, r2, r3, int64_t)
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+
+  return length;
+}
+#undef VECTOR_NOR
+
 template <class T>
 void VectorLoadComplement(void* dst, void* src) {
   int8_t* src_ptr = reinterpret_cast<int8_t*>(src);
@@ -3530,6 +3681,27 @@ EVALUATE(VLC) {
   return length;
 }
 
+EVALUATE(VPERM) {
+  DCHECK_OPCODE(VPERM);
+  DECODE_VRR_E_INSTRUCTION(r1, r2, r3, r4, m6, m5);
+  USE(m5);
+  USE(m6);
+  for (int i = 0; i < kSimd128Size; i++) {
+    int8_t lane_num = get_simd_register_by_lane<int8_t>(r4, i);
+    int reg = r2;
+    if (lane_num >= kSimd128Size) {
+      lane_num = lane_num - kSimd128Size;
+      reg = r3;
+    }
+    int8_t result = 0;
+    if (lane_num >= 0 && lane_num < kSimd128Size * 2) {
+      result = get_simd_register_by_lane<int8_t>(reg, lane_num);
+    }
+    set_simd_register_by_lane<int8_t>(r1, i, result);
+  }
+  return length;
+}
+
 EVALUATE(VSEL) {
   DCHECK_OPCODE(VSEL);
   DECODE_VRR_E_INSTRUCTION(r1, r2, r3, r4, m6, m5);
@@ -3606,6 +3778,65 @@ EVALUATE(VESRL) {
   return length;
 }
 
+#define VECTOR_SHIFT_WITH_OPERAND_TYPE(r1, r2, r3, type, op)             \
+  for (size_t i = 0, j = 0; j < kSimd128Size; i++, j += sizeof(type)) {  \
+    type src0 = get_simd_register_by_lane<type>(r2, i);                  \
+    type src1 = get_simd_register_by_lane<type>(r3, i);                  \
+    set_simd_register_by_lane<type>(r1, i,                               \
+                                    src0 op(src1 % (sizeof(type) * 8))); \
+  }
+
+#define VECTOR_SHIFT_WITH_OPERAND(r1, r2, r3, op, sign)             \
+  switch (m4) {                                                     \
+    case 0: {                                                       \
+      VECTOR_SHIFT_WITH_OPERAND_TYPE(r1, r2, r3, sign##int8_t, op)  \
+      break;                                                        \
+    }                                                               \
+    case 1: {                                                       \
+      VECTOR_SHIFT_WITH_OPERAND_TYPE(r1, r2, r3, sign##int16_t, op) \
+      break;                                                        \
+    }                                                               \
+    case 2: {                                                       \
+      VECTOR_SHIFT_WITH_OPERAND_TYPE(r1, r2, r3, sign##int32_t, op) \
+      break;                                                        \
+    }                                                               \
+    case 3: {                                                       \
+      VECTOR_SHIFT_WITH_OPERAND_TYPE(r1, r2, r3, sign##int64_t, op) \
+      break;                                                        \
+    }                                                               \
+    default:                                                        \
+      UNREACHABLE();                                                \
+  }
+
+EVALUATE(VESLV) {
+  DCHECK_OPCODE(VESLV);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  VECTOR_SHIFT_WITH_OPERAND(r1, r2, r3, <<, )
+  return length;
+}
+
+EVALUATE(VESRAV) {
+  DCHECK_OPCODE(VESRAV);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  VECTOR_SHIFT_WITH_OPERAND(r1, r2, r3, >>, )
+  return length;
+}
+
+EVALUATE(VESRLV) {
+  DCHECK_OPCODE(VESRLV);
+  DECODE_VRR_C_INSTRUCTION(r1, r2, r3, m6, m5, m4);
+  USE(m6);
+  USE(m5);
+  VECTOR_SHIFT_WITH_OPERAND(r1, r2, r3, >>, u)
+  return length;
+}
+#undef VECTOR_SHIFT_WITH_OPERAND
+#undef VECTOR_SHIFT_WITH_OPERAND_TYPE
+
 EVALUATE(VTM) {
   DCHECK_OPCODE(VTM);
   DECODE_VRR_A_INSTRUCTION(r1, r2, m5, m4, m3);
@@ -3688,6 +3919,63 @@ EVALUATE(VFD) {
   return length;
 }
 
+#define VECTOR_FP_MULTIPLY_QFMS_OPERATION(type, op, sign, first_lane_only) \
+  for (size_t i = 0, j = 0; j < kSimd128Size; i++, j += sizeof(type)) {    \
+    type src0 = get_simd_register_by_lane<type>(r2, i);                    \
+    type src1 = get_simd_register_by_lane<type>(r3, i);                    \
+    type src2 = get_simd_register_by_lane<type>(r4, i);                    \
+    type result = sign * (src0 * src1 op src2);                            \
+    if (isinf(src0)) result = src0;                                        \
+    if (isinf(src1)) result = src1;                                        \
+    if (isinf(src2)) result = src2;                                        \
+    set_simd_register_by_lane<type>(r1, i, result);                        \
+    if (first_lane_only) break;                                            \
+  }
+
+#define VECTOR_FP_MULTIPLY_QFMS(op, sign)                          \
+  switch (m6) {                                                    \
+    case 2:                                                        \
+      DCHECK(CpuFeatures::IsSupported(VECTOR_ENHANCE_FACILITY_1)); \
+      if (m5 == 8) {                                               \
+        VECTOR_FP_MULTIPLY_QFMS_OPERATION(float, op, sign, true)   \
+      } else {                                                     \
+        DCHECK_EQ(m5, 0);                                          \
+        VECTOR_FP_MULTIPLY_QFMS_OPERATION(float, op, sign, false)  \
+      }                                                            \
+      break;                                                       \
+    case 3:                                                        \
+      if (m5 == 8) {                                               \
+        VECTOR_FP_MULTIPLY_QFMS_OPERATION(double, op, sign, true)  \
+      } else {                                                     \
+        DCHECK_EQ(m5, 0);                                          \
+        VECTOR_FP_MULTIPLY_QFMS_OPERATION(double, op, sign, false) \
+      }                                                            \
+      break;                                                       \
+    default:                                                       \
+      UNREACHABLE();                                               \
+      break;                                                       \
+  }
+
+EVALUATE(VFMA) {
+  DCHECK_OPCODE(VFMA);
+  DECODE_VRR_E_INSTRUCTION(r1, r2, r3, r4, m6, m5);
+  USE(m5);
+  USE(m6);
+  VECTOR_FP_MULTIPLY_QFMS(+, 1)
+  return length;
+}
+
+EVALUATE(VFNMS) {
+  DCHECK_OPCODE(VFNMS);
+  DECODE_VRR_E_INSTRUCTION(r1, r2, r3, r4, m6, m5);
+  USE(m5);
+  USE(m6);
+  VECTOR_FP_MULTIPLY_QFMS(-, -1)
+  return length;
+}
+#undef VECTOR_FP_MULTIPLY_QFMS
+#undef VECTOR_FP_MULTIPLY_QFMS_OPERATION
+
 template <class T, class Operation>
 void VectorFPMaxMin(void* dst, void* src1, void* src2, Operation op) {
   T* dst_ptr = reinterpret_cast<T*>(dst);
@@ -3707,8 +3995,13 @@ void VectorFPMaxMin(void* dst, void* src1, void* src2, Operation op) {
 
 #define VECTOR_FP_MAX_MIN_FOR_TYPE(type, op)                           \
   VectorFPMaxMin<type>(&get_simd_register(r1), &get_simd_register(r2), \
-                       &get_simd_register(r3),                         \
-                       [](type a, type b) { return (a op b) ? a : b; });
+                       &get_simd_register(r3), [](type a, type b) {    \
+                         if (signbit(b) op signbit(a))                 \
+                           return a;                                   \
+                         else if (signbit(b) != signbit(a))            \
+                           return b;                                   \
+                         return (a op b) ? a : b;                      \
+                       });
 
 #define VECTOR_FP_MAX_MIN(op)                                                  \
   switch (m4) {                                                                \
@@ -4388,13 +4681,14 @@ EVALUATE(LPR) {
   // Load Positive (32)
   DECODE_RR_INSTRUCTION(r1, r2);
   int32_t r2_val = get_low_register<int32_t>(r2);
-  // If negative, then negate it.
-  r2_val = (r2_val < 0) ? -r2_val : r2_val;
-  set_low_register(r1, r2_val);
   SetS390ConditionCode<int32_t>(r2_val, 0);
   if (r2_val == (static_cast<int32_t>(1) << 31)) {
     SetS390OverflowCode(true);
+  } else {
+    // If negative and not overflowing, then negate it.
+    r2_val = (r2_val < 0) ? -r2_val : r2_val;
   }
+  set_low_register(r1, r2_val);
   return length;
 }
 
@@ -6430,7 +6724,7 @@ EVALUATE(TRAP4) {
   int length = 4;
   // whack the space of the caller allocated stack
   int64_t sp_addr = get_register(sp);
-  for (int i = 0; i < kCalleeRegisterSaveAreaSize / kPointerSize; ++i) {
+  for (int i = 0; i < kCalleeRegisterSaveAreaSize / kSystemPointerSize; ++i) {
     // we dont want to whack the RA (r14)
     if (i != 14) (reinterpret_cast<intptr_t*>(sp_addr))[i] = 0xDEADBABE;
   }
@@ -7089,14 +7383,19 @@ EVALUATE(CFEBRA) {
       break;
     }
     case ROUND_TOWARD_0: {
-      // check for overflow, cast r2_fval to 64bit integer
+      // check for overflow, cast r2_fval to double
       // then check value within the range of INT_MIN and INT_MAX
       // and set condition code accordingly
-      int64_t temp = static_cast<int64_t>(r2_fval);
-      if (temp < INT_MIN || temp > INT_MAX) {
+      double temp = static_cast<double>(r2_fval);
+      if (temp < INT_MIN) {
+        r1_val = kMinInt;
+        condition_reg_ = CC_OF;
+      } else if (temp > INT_MAX) {
+        r1_val = kMaxInt;
         condition_reg_ = CC_OF;
+      } else {
+        r1_val = static_cast<int32_t>(r2_fval);
       }
-      r1_val = static_cast<int32_t>(r2_fval);
       break;
     }
     case ROUND_TOWARD_PLUS_INFINITE: {
@@ -7216,8 +7515,11 @@ EVALUATE(CLFEBR) {
   DECODE_RRE_INSTRUCTION(r1, r2);
   float r2_val = get_float32_from_d_register(r2);
   uint32_t r1_val = static_cast<uint32_t>(r2_val);
-  set_low_register(r1, r1_val);
   SetS390ConvertConditionCode<double>(r2_val, r1_val, UINT32_MAX);
+  double temp = static_cast<double>(r2_val);
+  if (temp < 0) r1_val = 0;
+  if (temp > kMaxUInt32) r1_val = kMaxUInt32;
+  set_low_register(r1, r1_val);
   return length;
 }
 
@@ -7743,12 +8045,14 @@ EVALUATE(LPGR) {
   // Load Positive (32)
   DECODE_RRE_INSTRUCTION(r1, r2);
   int64_t r2_val = get_register(r2);
-  r2_val = (r2_val < 0) ? -r2_val : r2_val;  // If negative, then negate it.
-  set_register(r1, r2_val);
   SetS390ConditionCode<int64_t>(r2_val, 0);
   if (r2_val == (static_cast<int64_t>(1) << 63)) {
     SetS390OverflowCode(true);
+  } else {
+    // If negative and not overflowing, then negate it.
+    r2_val = (r2_val < 0) ? -r2_val : r2_val;
   }
+  set_register(r1, r2_val);
   return length;
 }
 
@@ -10897,6 +11201,7 @@ EVALUATE(CXZT) {
 #undef DECODE_VRR_B_INSTRUCTION
 #undef DECODE_VRR_C_INSTRUCTION
 #undef DECODE_VRR_E_INSTRUCTION
+#undef DECODE_VRR_F_INSTRUCTION
 #undef DECODE_VRX_INSTRUCTION
 #undef DECODE_VRS_INSTRUCTION
 #undef DECODE_VRI_A_INSTRUCTION
diff --git a/deps/v8/src/execution/s390/simulator-s390.h b/deps/v8/src/execution/s390/simulator-s390.h
index 0921ac839e..57dbb1e3de 100644
--- a/deps/v8/src/execution/s390/simulator-s390.h
+++ b/deps/v8/src/execution/s390/simulator-s390.h
@@ -230,6 +230,7 @@ class Simulator : public SimulatorBase {
   void HandleRList(Instruction* instr, bool load);
   void HandleVList(Instruction* inst);
   void SoftwareInterrupt(Instruction* instr);
+  void DebugAtNextPC();
 
   // Stop helper functions.
   inline bool isStopInstruction(Instruction* instr);
@@ -457,7 +458,7 @@ class Simulator : public SimulatorBase {
 
   // Simulator support.
   char* stack_;
-  static const size_t stack_protection_size_ = 256 * kPointerSize;
+  static const size_t stack_protection_size_ = 256 * kSystemPointerSize;
   bool pc_modified_;
   int64_t icount_;
 
@@ -502,6 +503,7 @@ class Simulator : public SimulatorBase {
   S390_VRR_A_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
   S390_VRR_C_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
   S390_VRR_E_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
+  S390_VRR_F_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
   S390_VRX_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
   S390_VRS_A_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
   S390_VRS_B_OPCODE_LIST(EVALUATE_VR_INSTRUCTIONS)
diff --git a/deps/v8/src/execution/simulator-base.h b/deps/v8/src/execution/simulator-base.h
index 6eca3f2b47..58aa753a33 100644
--- a/deps/v8/src/execution/simulator-base.h
+++ b/deps/v8/src/execution/simulator-base.h
@@ -121,6 +121,7 @@ class SimulatorBase {
 //  - V8_TARGET_ARCH_MIPS: swi (software-interrupt)
 //  - V8_TARGET_ARCH_MIPS64: swi (software-interrupt)
 //  - V8_TARGET_ARCH_PPC: svc (Supervisor Call)
+//  - V8_TARGET_ARCH_PPC64: svc (Supervisor Call)
 //  - V8_TARGET_ARCH_S390: svc (Supervisor Call)
 class Redirection {
  public:
diff --git a/deps/v8/src/execution/simulator.h b/deps/v8/src/execution/simulator.h
index 4000973a24..a4e07b235b 100644
--- a/deps/v8/src/execution/simulator.h
+++ b/deps/v8/src/execution/simulator.h
@@ -18,7 +18,7 @@
 #include "src/execution/arm64/simulator-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/execution/arm/simulator-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/execution/ppc/simulator-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/execution/mips/simulator-mips.h"
diff --git a/deps/v8/src/execution/stack-guard.h b/deps/v8/src/execution/stack-guard.h
index febd1ecb0a..b445158557 100644
--- a/deps/v8/src/execution/stack-guard.h
+++ b/deps/v8/src/execution/stack-guard.h
@@ -130,7 +130,7 @@ class V8_EXPORT_PRIVATE StackGuard final {
     // The stack limit is split into a JavaScript and a C++ stack limit. These
     // two are the same except when running on a simulator where the C++ and
     // JavaScript stacks are separate. Each of the two stack limits have two
-    // values. The one eith the real_ prefix is the actual stack limit
+    // values. The one with the real_ prefix is the actual stack limit
     // set for the VM. The one without the real_ prefix has the same value as
     // the actual stack limit except when there is an interruption (e.g. debug
     // break or preemption) in which case it is lowered to make stack checks
diff --git a/deps/v8/src/execution/vm-state-inl.h b/deps/v8/src/execution/vm-state-inl.h
index 87dc185f2d..1781917764 100644
--- a/deps/v8/src/execution/vm-state-inl.h
+++ b/deps/v8/src/execution/vm-state-inl.h
@@ -14,11 +14,9 @@
 namespace v8 {
 namespace internal {
 
-//
-// VMState class implementation.  A simple stack of VM states held by the
-// logger and partially threaded through the call stack.  States are pushed by
-// VMState construction and popped by destruction.
-//
+// VMState class implementation. A simple stack of VM states held by the logger
+// and partially threaded through the call stack. States are pushed by VMState
+// construction and popped by destruction.
 inline const char* StateToString(StateTag state) {
   switch (state) {
     case JS:
@@ -35,6 +33,8 @@ inline const char* StateToString(StateTag state) {
       return "OTHER";
     case EXTERNAL:
       return "EXTERNAL";
+    case ATOMICS_WAIT:
+      return "ATOMICS_WAIT";
     case IDLE:
       return "IDLE";
   }
diff --git a/deps/v8/src/execution/vm-state.h b/deps/v8/src/execution/vm-state.h
index 38b70f5a95..2ccde290d5 100644
--- a/deps/v8/src/execution/vm-state.h
+++ b/deps/v8/src/execution/vm-state.h
@@ -11,11 +11,10 @@
 namespace v8 {
 namespace internal {
 
-// Logging and profiling.  A StateTag represents a possible state of
-// the VM. The logger maintains a stack of these. Creating a VMState
-// object enters a state by pushing on the stack, and destroying a
-// VMState object leaves a state by popping the current state from the
-// stack.
+// Logging and profiling. A StateTag represents a possible state of the VM. The
+// logger maintains a stack of these. Creating a VMState object enters a state
+// by pushing on the stack, and destroying a VMState object leaves a state by
+// popping the current state from the stack.
 template <StateTag Tag>
 class VMState {
  public:
diff --git a/deps/v8/src/execution/x64/frame-constants-x64.h b/deps/v8/src/execution/x64/frame-constants-x64.h
index 409880cc7b..6ce0a02e14 100644
--- a/deps/v8/src/execution/x64/frame-constants-x64.h
+++ b/deps/v8/src/execution/x64/frame-constants-x64.h
@@ -5,6 +5,7 @@
 #ifndef V8_EXECUTION_X64_FRAME_CONSTANTS_X64_H_
 #define V8_EXECUTION_X64_FRAME_CONSTANTS_X64_H_
 
+#include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "src/execution/frame-constants.h"
 
@@ -54,6 +55,42 @@ class WasmCompileLazyFrameConstants : public TypedFrameConstants {
       kNumberOfSavedFpParamRegs * kSimd128Size;
 };
 
+// Frame constructed by the {WasmDebugBreak} builtin.
+// After pushing the frame type marker, the builtin pushes all Liftoff cache
+// registers (see liftoff-assembler-defs.h).
+class WasmDebugBreakFrameConstants : public TypedFrameConstants {
+ public:
+  // {rax, rcx, rdx, rbx, rsi, rdi, r9}
+  static constexpr uint32_t kPushedGpRegs = 0b1011001111;
+  // {xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7}
+  static constexpr uint32_t kPushedFpRegs = 0b11111111;
+
+  static constexpr int kNumPushedGpRegisters =
+      base::bits::CountPopulation(kPushedGpRegs);
+  static constexpr int kNumPushedFpRegisters =
+      base::bits::CountPopulation(kPushedFpRegs);
+
+  static constexpr int kLastPushedGpRegisterOffset =
+      -kFixedFrameSizeFromFp - kNumPushedGpRegisters * kSystemPointerSize;
+  static constexpr int kLastPushedFpRegisterOffset =
+      kLastPushedGpRegisterOffset - kNumPushedFpRegisters * kSimd128Size;
+
+  // Offsets are fp-relative.
+  static int GetPushedGpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedGpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedGpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedGpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSystemPointerSize;
+  }
+
+  static int GetPushedFpRegisterOffset(int reg_code) {
+    DCHECK_NE(0, kPushedFpRegs & (1 << reg_code));
+    uint32_t lower_regs = kPushedFpRegs & ((uint32_t{1} << reg_code) - 1);
+    return kLastPushedFpRegisterOffset +
+           base::bits::CountPopulation(lower_regs) * kSimd128Size;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/extensions/cputracemark-extension.cc b/deps/v8/src/extensions/cputracemark-extension.cc
index 6162afad5f..9dfa9761fd 100644
--- a/deps/v8/src/extensions/cputracemark-extension.cc
+++ b/deps/v8/src/extensions/cputracemark-extension.cc
@@ -16,12 +16,10 @@ CpuTraceMarkExtension::GetNativeFunctionTemplate(v8::Isolate* isolate,
 void CpuTraceMarkExtension::Mark(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() < 1 || !args[0]->IsUint32()) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(
-            args.GetIsolate(),
-            "First parameter to cputracemark() must be a unsigned int32.",
-            NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "First parameter to cputracemark() must be a unsigned int32."));
+    return;
   }
 
 #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
diff --git a/deps/v8/src/extensions/externalize-string-extension.cc b/deps/v8/src/extensions/externalize-string-extension.cc
index 00a946b6ff..b153ebd075 100644
--- a/deps/v8/src/extensions/externalize-string-extension.cc
+++ b/deps/v8/src/extensions/externalize-string-extension.cc
@@ -59,11 +59,9 @@ ExternalizeStringExtension::GetNativeFunctionTemplate(
 void ExternalizeStringExtension::Externalize(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() < 1 || !args[0]->IsString()) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(
-            args.GetIsolate(),
-            "First parameter to externalizeString() must be a string.",
-            NewStringType::kNormal).ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "First parameter to externalizeString() must be a string."));
     return;
   }
   bool force_two_byte = false;
@@ -71,22 +69,17 @@ void ExternalizeStringExtension::Externalize(
     if (args[1]->IsBoolean()) {
       force_two_byte = args[1]->BooleanValue(args.GetIsolate());
     } else {
-      args.GetIsolate()->ThrowException(
-          v8::String::NewFromUtf8(
-              args.GetIsolate(),
-              "Second parameter to externalizeString() must be a boolean.",
-              NewStringType::kNormal).ToLocalChecked());
+      args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+          args.GetIsolate(),
+          "Second parameter to externalizeString() must be a boolean."));
       return;
     }
   }
   bool result = false;
   Handle<String> string = Utils::OpenHandle(*args[0].As<v8::String>());
   if (!string->SupportsExternalization()) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(),
-                                "string does not support externalization.",
-                                NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(), "string does not support externalization."));
     return;
   }
   if (string->IsOneByteRepresentation() && !force_two_byte) {
@@ -105,10 +98,8 @@ void ExternalizeStringExtension::Externalize(
     if (!result) delete resource;
   }
   if (!result) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(),
-                                "externalizeString() failed.",
-                                NewStringType::kNormal).ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(), "externalizeString() failed."));
     return;
   }
 }
@@ -117,11 +108,9 @@ void ExternalizeStringExtension::Externalize(
 void ExternalizeStringExtension::IsOneByte(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1 || !args[0]->IsString()) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(
-            args.GetIsolate(),
-            "isOneByteString() requires a single string argument.",
-            NewStringType::kNormal).ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "isOneByteString() requires a single string argument."));
     return;
   }
   bool is_one_byte =
diff --git a/deps/v8/src/extensions/statistics-extension.cc b/deps/v8/src/extensions/statistics-extension.cc
index 8f897ae97e..9d63d760ec 100644
--- a/deps/v8/src/extensions/statistics-extension.cc
+++ b/deps/v8/src/extensions/statistics-extension.cc
@@ -27,10 +27,10 @@ static void AddCounter(v8::Isolate* isolate,
                        StatsCounter* counter,
                        const char* name) {
   if (counter->Enabled()) {
-    object->Set(isolate->GetCurrentContext(),
-                v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
-                    .ToLocalChecked(),
-                v8::Number::New(isolate, *counter->GetInternalPointer()))
+    object
+        ->Set(isolate->GetCurrentContext(),
+              v8::String::NewFromUtf8(isolate, name).ToLocalChecked(),
+              v8::Number::New(isolate, *counter->GetInternalPointer()))
         .FromJust();
   }
 }
@@ -39,8 +39,7 @@ static void AddNumber(v8::Isolate* isolate, v8::Local<v8::Object> object,
                       double value, const char* name) {
   object
       ->Set(isolate->GetCurrentContext(),
-            v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
-                .ToLocalChecked(),
+            v8::String::NewFromUtf8(isolate, name).ToLocalChecked(),
             v8::Number::New(isolate, value))
       .FromJust();
 }
@@ -50,10 +49,11 @@ static void AddNumber64(v8::Isolate* isolate,
                         v8::Local<v8::Object> object,
                         int64_t value,
                         const char* name) {
-  object->Set(isolate->GetCurrentContext(),
-              v8::String::NewFromUtf8(isolate, name, NewStringType::kNormal)
-                  .ToLocalChecked(),
-              v8::Number::New(isolate, static_cast<double>(value))).FromJust();
+  object
+      ->Set(isolate->GetCurrentContext(),
+            v8::String::NewFromUtf8(isolate, name).ToLocalChecked(),
+            v8::Number::New(isolate, static_cast<double>(value)))
+      .FromJust();
 }
 
 
diff --git a/deps/v8/src/extensions/vtunedomain-support-extension.cc b/deps/v8/src/extensions/vtunedomain-support-extension.cc
index e5b68ff63d..793ffec716 100644
--- a/deps/v8/src/extensions/vtunedomain-support-extension.cc
+++ b/deps/v8/src/extensions/vtunedomain-support-extension.cc
@@ -109,13 +109,10 @@ void VTuneDomainSupportExtension::Mark(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 3 || !args[0]->IsString() || !args[1]->IsString() ||
       !args[2]->IsString()) {
-    args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(
-            args.GetIsolate(),
-            "Parameter number should be exactly three, first domain name"
-            "second task name, third start/end",
-            NewStringType::kNormal)
-            .ToLocalChecked());
+    args.GetIsolate()->ThrowException(v8::String::NewFromUtf8Literal(
+        args.GetIsolate(),
+        "Parameter number should be exactly three, first domain name"
+        "second task name, third start/end"));
     return;
   }
 
@@ -134,8 +131,7 @@ void VTuneDomainSupportExtension::Mark(
   int r = 0;
   if ((r = libvtune::invoke(params.str().c_str())) != 0) {
     args.GetIsolate()->ThrowException(
-        v8::String::NewFromUtf8(args.GetIsolate(), std::to_string(r).c_str(),
-                                NewStringType::kNormal)
+        v8::String::NewFromUtf8(args.GetIsolate(), std::to_string(r).c_str())
             .ToLocalChecked());
   }
 }
diff --git a/deps/v8/src/flags/flag-definitions.h b/deps/v8/src/flags/flag-definitions.h
index 2eb2bbc80e..c3f360cdf0 100644
--- a/deps/v8/src/flags/flag-definitions.h
+++ b/deps/v8/src/flags/flag-definitions.h
@@ -134,6 +134,12 @@ struct MaybeBoolFlag {
 #define COMPRESS_POINTERS_BOOL false
 #endif
 
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+#define ENABLE_CONTROL_FLOW_INTEGRITY_BOOL true
+#else
+#define ENABLE_CONTROL_FLOW_INTEGRITY_BOOL false
+#endif
+
 // Supported ARM configurations are:
 //  "armv6":       ARMv6 + VFPv2
 //  "armv7":       ARMv7 + VFPv3-D32 + NEON
@@ -167,6 +173,8 @@ struct MaybeBoolFlag {
   FLAG(MAYBE_BOOL, MaybeBoolFlag, nam, {false COMMA false}, cmt)
 #define DEFINE_INT(nam, def, cmt) FLAG(INT, int, nam, def, cmt)
 #define DEFINE_UINT(nam, def, cmt) FLAG(UINT, unsigned int, nam, def, cmt)
+#define DEFINE_UINT_READONLY(nam, def, cmt) \
+  FLAG_READONLY(UINT, unsigned int, nam, def, cmt)
 #define DEFINE_UINT64(nam, def, cmt) FLAG(UINT64, uint64_t, nam, def, cmt)
 #define DEFINE_FLOAT(nam, def, cmt) FLAG(FLOAT, double, nam, def, cmt)
 #define DEFINE_SIZE_T(nam, def, cmt) FLAG(SIZE_T, size_t, nam, def, cmt)
@@ -368,7 +376,7 @@ DEFINE_BOOL(assert_types, false,
 DEFINE_BOOL(allocation_site_pretenuring, true,
             "pretenure with allocation sites")
 DEFINE_BOOL(page_promotion, true, "promote pages based on utilization")
-DEFINE_BOOL(always_promote_young_mc, false,
+DEFINE_BOOL(always_promote_young_mc, true,
             "always promote young objects during mark-compact")
 DEFINE_INT(page_promotion_threshold, 70,
            "min percentage of live bytes on a page to enable fast evacuation")
@@ -397,7 +405,7 @@ DEFINE_BOOL_READONLY(internalize_on_the_fly, true,
                      "internalize string keys for generic keyed ICs on the fly")
 
 // Flag for one shot optimiztions.
-DEFINE_BOOL(enable_one_shot_optimization, true,
+DEFINE_BOOL(enable_one_shot_optimization, false,
             "Enable size optimizations for the code that will "
             "only be executed once")
 
@@ -486,7 +494,7 @@ DEFINE_BOOL(turboprop, false,
             "enable experimental turboprop mid-tier compiler.")
 DEFINE_NEG_IMPLICATION(turboprop, turbo_inlining)
 DEFINE_IMPLICATION(turboprop, concurrent_inlining)
-DEFINE_VALUE_IMPLICATION(turboprop, interrupt_budget, 10 * KB)
+DEFINE_VALUE_IMPLICATION(turboprop, interrupt_budget, 15 * KB)
 
 // Flags for concurrent recompilation.
 DEFINE_BOOL(concurrent_recompilation, true,
@@ -636,6 +644,7 @@ DEFINE_BOOL(turbo_rewrite_far_jumps, true,
 DEFINE_BOOL(
     stress_gc_during_compilation, false,
     "simulate GC/compiler thread race related to https://crbug.com/v8/8520")
+DEFINE_BOOL(turbo_fast_api_calls, false, "enable fast API calls from TurboFan")
 
 // Favor memory over execution speed.
 DEFINE_BOOL(optimize_for_size, false,
@@ -668,9 +677,12 @@ DEFINE_BOOL(wasm_async_compilation, true,
             "enable actual asynchronous compilation for WebAssembly.compile")
 DEFINE_BOOL(wasm_test_streaming, false,
             "use streaming compilation instead of async compilation for tests")
-// TODO(4153): Set this back to v8::internal::wasm::kV8MaxWasmMemoryPages
-DEFINE_UINT(wasm_max_mem_pages, 32767,
-            "maximum number of 64KiB memory pages of a wasm instance")
+DEFINE_UINT(wasm_max_mem_pages,
+            v8::internal::wasm::kSpecMaxWasmInitialMemoryPages,
+            "maximum initial number of 64KiB memory pages of a wasm instance")
+DEFINE_UINT(wasm_max_mem_pages_growth,
+            v8::internal::wasm::kSpecMaxWasmMaximumMemoryPages,
+            "maximum number of 64KiB pages a Wasm memory can grow to")
 DEFINE_UINT(wasm_max_table_size, v8::internal::wasm::kV8MaxWasmTableSize,
             "maximum table size of a wasm instance")
 DEFINE_UINT(wasm_max_code_space, v8::internal::kMaxWasmCodeMB,
@@ -709,6 +721,7 @@ DEFINE_INT(wasm_tier_mask_for_testing, 0,
 DEFINE_BOOL(debug_in_liftoff, false,
             "use Liftoff instead of the C++ interpreter for debugging "
             "WebAssembly (experimental)")
+DEFINE_IMPLICATION(future, debug_in_liftoff)
 
 DEFINE_BOOL(validate_asm, true, "validate asm.js modules before compiling")
 DEFINE_BOOL(suppress_asm_messages, false,
@@ -723,7 +736,7 @@ DEFINE_DEBUG_BOOL(dump_wasm_module, false, "dump wasm module bytes")
 DEFINE_STRING(dump_wasm_module_path, nullptr,
               "directory to dump wasm modules to")
 
-// Declare command-line flags for WASM features. Warning: avoid using these
+// Declare command-line flags for Wasm features. Warning: avoid using these
 // flags directly in the implementation. Instead accept wasm::WasmFeatures
 // for configurability.
 #include "src/wasm/wasm-feature-flags.h"
@@ -767,12 +780,20 @@ DEFINE_BOOL(wasm_lazy_compilation, false,
             "enable lazy compilation for all wasm modules")
 DEFINE_DEBUG_BOOL(trace_wasm_lazy_compilation, false,
                   "trace lazy compilation of wasm functions")
-DEFINE_BOOL(wasm_grow_shared_memory, true,
-            "allow growing shared WebAssembly memory objects")
-DEFINE_BOOL(wasm_atomics_on_non_shared_memory, false,
-            "allow atomic operations on non-shared WebAssembly memory")
 DEFINE_BOOL(wasm_lazy_validation, false,
             "enable lazy validation for lazily compiled wasm functions")
+
+// Flags for wasm prototyping that are not strictly features i.e., part of
+// an existing proposal that may be conditionally enabled.
+DEFINE_BOOL(wasm_atomics_on_non_shared_memory, false,
+            "allow atomic operations on non-shared WebAssembly memory")
+DEFINE_BOOL(wasm_grow_shared_memory, true,
+            "allow growing shared WebAssembly memory objects")
+DEFINE_BOOL(wasm_simd_post_mvp, false,
+            "allow experimental SIMD operations for prototyping that are not "
+            "included in the current proposal")
+DEFINE_IMPLICATION(wasm_simd_post_mvp, experimental_wasm_simd)
+
 // wasm-interpret-all resets {asm-,}wasm-lazy-compilation.
 DEFINE_NEG_IMPLICATION(wasm_interpret_all, asm_wasm_lazy_compilation)
 DEFINE_NEG_IMPLICATION(wasm_interpret_all, wasm_lazy_compilation)
@@ -781,9 +802,6 @@ DEFINE_BOOL(wasm_code_gc, true, "enable garbage collection of wasm code")
 DEFINE_BOOL(trace_wasm_code_gc, false, "trace garbage collection of wasm code")
 DEFINE_BOOL(stress_wasm_code_gc, false,
             "stress test garbage collection of wasm code")
-DEFINE_BOOL(wasm_far_jump_table, true,
-            "use multiple separate code spaces that might require far jumps "
-            "between them")
 DEFINE_INT(wasm_max_initial_code_space_reservation, 0,
            "maximum size of the initial wasm code space reservation (in MB)")
 
@@ -801,9 +819,6 @@ DEFINE_SIZE_T(max_semi_space_size, 0,
               "max size of a semi-space (in MBytes), the new space consists of "
               "two semi-spaces")
 DEFINE_INT(semi_space_growth_factor, 2, "factor by which to grow the new space")
-DEFINE_BOOL(experimental_new_space_growth_heuristic, false,
-            "Grow the new space based on the percentage of survivors instead "
-            "of their absolute value.")
 DEFINE_SIZE_T(max_old_space_size, 0, "max size of the old space (in Mbytes)")
 DEFINE_SIZE_T(
     max_heap_size, 0,
@@ -811,7 +826,7 @@ DEFINE_SIZE_T(
     "both max_semi_space_size and max_old_space_size take precedence. "
     "All three flags cannot be specified at the same time.")
 DEFINE_SIZE_T(initial_heap_size, 0, "initial size of the heap (in Mbytes)")
-DEFINE_BOOL(huge_max_old_generation_size, false,
+DEFINE_BOOL(huge_max_old_generation_size, true,
             "Increase max size of the old space to 4 GB for x64 systems with"
             "the physical memory bigger than 16 GB")
 DEFINE_SIZE_T(initial_old_space_size, 0, "initial old space size (in Mbytes)")
@@ -895,6 +910,7 @@ DEFINE_BOOL_READONLY(array_buffer_extension, V8_ARRAY_BUFFER_EXTENSION_BOOL,
 DEFINE_IMPLICATION(array_buffer_extension, always_promote_young_mc)
 DEFINE_BOOL(concurrent_array_buffer_sweeping, true,
             "concurrently sweep array buffers")
+DEFINE_BOOL(local_heaps, false, "allow heap access from background tasks")
 DEFINE_BOOL(parallel_marking, true, "use parallel marking in atomic pause")
 DEFINE_INT(ephemeron_fixpoint_iterations, 10,
            "number of fixpoint iterations it takes to switch to linear "
@@ -1014,8 +1030,6 @@ DEFINE_BOOL(young_generation_large_objects, true,
             "allocates large objects by default in the young generation large "
             "object space")
 
-DEFINE_BOOL(idle_time_scavenge, true, "Perform scavenges in idle time.")
-
 // assembler-ia32.cc / assembler-arm.cc / assembler-x64.cc
 DEFINE_BOOL(debug_code, DEBUG_BOOL,
             "generate extra code (assertions) for debugging")
@@ -1064,6 +1078,9 @@ DEFINE_BOOL(enable_regexp_unaligned_accesses, true,
 
 // api.cc
 DEFINE_BOOL(script_streaming, true, "enable parsing on background")
+DEFINE_BOOL(
+    finalize_streaming_on_background, false,
+    "perform the script streaming finalization on the background thread")
 DEFINE_BOOL(disable_old_api_accessors, false,
             "Disable old-style API accessors whose setters trigger through the "
             "prototype chain")
@@ -1211,6 +1228,15 @@ DEFINE_IMPLICATION(trace_maps, log_code)
 
 // parser.cc
 DEFINE_BOOL(allow_natives_syntax, false, "allow natives syntax")
+DEFINE_BOOL(allow_natives_for_fuzzing, false,
+            "allow only natives explicitly whitelisted for fuzzers")
+DEFINE_BOOL(allow_natives_for_differential_fuzzing, false,
+            "allow only natives explicitly whitelisted for differential "
+            "fuzzers")
+DEFINE_IMPLICATION(allow_natives_for_differential_fuzzing, allow_natives_syntax)
+DEFINE_IMPLICATION(allow_natives_for_fuzzing, allow_natives_syntax)
+DEFINE_IMPLICATION(allow_natives_for_differential_fuzzing,
+                   allow_natives_for_fuzzing)
 DEFINE_BOOL(parse_only, false, "only parse the sources")
 
 // simulator-arm.cc, simulator-arm64.cc and simulator-mips.cc
@@ -1233,8 +1259,6 @@ DEFINE_INT(sim_stack_size, 2 * MB / KB,
            "in kBytes (default is 2 MB)")
 DEFINE_BOOL(log_colour, ENABLE_LOG_COLOUR,
             "When logging, try to use coloured output.")
-DEFINE_BOOL(ignore_asm_unimplemented_break, false,
-            "Don't break for ASM_UNIMPLEMENTED_BREAK macros.")
 DEFINE_BOOL(trace_sim_messages, false,
             "Trace simulator debug messages. Implied by --trace-sim.")
 
@@ -1279,15 +1303,25 @@ DEFINE_GENERIC_IMPLICATION(
     runtime_call_stats,
     TracingFlags::runtime_stats.store(
         v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE))
+DEFINE_BOOL(rcs, false, "report runtime call counts and times")
+DEFINE_IMPLICATION(rcs, runtime_call_stats)
+
+DEFINE_BOOL(rcs_cpu_time, false,
+            "report runtime times in cpu time (the default is wall time)")
+DEFINE_IMPLICATION(rcs_cpu_time, rcs)
 
 // snapshot-common.cc
 DEFINE_BOOL(profile_deserialization, false,
             "Print the time it takes to deserialize the snapshot.")
 DEFINE_BOOL(serialization_statistics, false,
             "Collect statistics on serialized objects.")
+#ifdef V8_ENABLE_THIRD_PARTY_HEAP
+DEFINE_UINT_READONLY(serialization_chunk_size, 1,
+                     "Custom size for serialization chunks")
+#else
 DEFINE_UINT(serialization_chunk_size, 4096,
             "Custom size for serialization chunks")
-
+#endif
 // Regexp
 DEFINE_BOOL(regexp_optimization, true, "generate optimized regexp code")
 DEFINE_BOOL(regexp_mode_modifiers, false, "enable inline flags in regexp.")
@@ -1380,6 +1414,18 @@ DEFINE_BOOL(multi_mapped_mock_allocator, false,
             "Use a multi-mapped mock ArrayBuffer allocator for testing.")
 #endif
 
+// Flags for Wasm GDB remote debugging.
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+#define DEFAULT_WASM_GDB_REMOTE_PORT 8765
+DEFINE_BOOL(wasm_gdb_remote, false,
+            "enable GDB-remote for WebAssembly debugging")
+DEFINE_INT(wasm_gdb_remote_port, DEFAULT_WASM_GDB_REMOTE_PORT,
+           "default port for WebAssembly debugging with LLDB.")
+DEFINE_BOOL(wasm_pause_waiting_for_debugger, false,
+            "pause at the first Webassembly instruction waiting for a debugger "
+            "to attach")
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
 //
 // GDB JIT integration flags.
 //
@@ -1465,6 +1511,10 @@ DEFINE_BOOL(print_break_location, false, "print source location on debug break")
 DEFINE_DEBUG_BOOL(trace_wasm_instances, false,
                   "trace creation and collection of wasm instances")
 
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+DEFINE_BOOL(trace_wasm_gdb_remote, false, "trace Webassembly GDB-remote server")
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
 //
 // Logging and profiling flags
 //
@@ -1575,8 +1625,8 @@ DEFINE_BOOL(vtune_prof_annotate_wasm, false,
 
 DEFINE_BOOL(win64_unwinding_info, true, "Enable unwinding info for Windows/x64")
 
-#ifdef V8_TARGET_ARCH_ARM
-// Unsupported on arm. See https://crbug.com/v8/8713.
+#if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_S390X)
+// Unsupported on above architectures. See https://crbug.com/v8/8713.
 DEFINE_BOOL_READONLY(
     interpreted_frames_native_stack, false,
     "Show interpreted frames on the native stack (useful for external "
@@ -1651,7 +1701,6 @@ DEFINE_BOOL(predictable_gc_schedule, false,
 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, min_semi_space_size, 4)
 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, max_semi_space_size, 4)
 DEFINE_VALUE_IMPLICATION(predictable_gc_schedule, heap_growing_percent, 30)
-DEFINE_NEG_IMPLICATION(predictable_gc_schedule, idle_time_scavenge)
 DEFINE_NEG_IMPLICATION(predictable_gc_schedule, memory_reducer)
 
 //
diff --git a/deps/v8/src/flags/flags.cc b/deps/v8/src/flags/flags.cc
index 15f87b0b74..e3564d0f6b 100644
--- a/deps/v8/src/flags/flags.cc
+++ b/deps/v8/src/flags/flags.cc
@@ -594,9 +594,12 @@ static uint32_t flag_hash = 0;
 
 void ComputeFlagListHash() {
   std::ostringstream modified_args_as_string;
-#ifdef DEBUG
-  modified_args_as_string << "debug";
-#endif  // DEBUG
+  if (COMPRESS_POINTERS_BOOL) {
+    modified_args_as_string << "ptr-compr";
+  }
+  if (DEBUG_BOOL) {
+    modified_args_as_string << "debug";
+  }
   for (size_t i = 0; i < num_flags; ++i) {
     Flag* current = &flags[i];
     if (current->type() == Flag::TYPE_BOOL &&
diff --git a/deps/v8/src/handles/factory-handles.h b/deps/v8/src/handles/factory-handles.h
deleted file mode 100644
index 312ced8b7c..0000000000
--- a/deps/v8/src/handles/factory-handles.h
+++ /dev/null
@@ -1,23 +0,0 @@
-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_HANDLES_FACTORY_HANDLES_H_
-#define V8_HANDLES_FACTORY_HANDLES_H_
-
-namespace v8 {
-namespace internal {
-
-template <typename Impl>
-struct FactoryTraits;
-
-template <typename Impl, typename T>
-using FactoryHandle = typename FactoryTraits<Impl>::template HandleType<T>;
-template <typename Impl, typename T>
-using FactoryMaybeHandle =
-    typename FactoryTraits<Impl>::template MaybeHandleType<T>;
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_HANDLES_FACTORY_HANDLES_H_
diff --git a/deps/v8/src/handles/global-handles.cc b/deps/v8/src/handles/global-handles.cc
index fcec0ca761..df4042e8eb 100644
--- a/deps/v8/src/handles/global-handles.cc
+++ b/deps/v8/src/handles/global-handles.cc
@@ -186,6 +186,9 @@ class GlobalHandles::NodeSpace final {
   iterator begin() { return iterator(first_used_block_); }
   iterator end() { return iterator(nullptr); }
 
+  size_t TotalSize() const { return blocks_ * sizeof(NodeType) * kBlockSize; }
+  size_t handles_count() const { return handles_count_; }
+
  private:
   void PutNodesOnFreeList(BlockType* block);
   V8_INLINE void Free(NodeType* node);
@@ -194,6 +197,8 @@ class GlobalHandles::NodeSpace final {
   BlockType* first_block_ = nullptr;
   BlockType* first_used_block_ = nullptr;
   NodeType* first_free_ = nullptr;
+  size_t blocks_ = 0;
+  size_t handles_count_ = 0;
 };
 
 template <class NodeType>
@@ -210,6 +215,7 @@ template <class NodeType>
 NodeType* GlobalHandles::NodeSpace<NodeType>::Acquire(Object object) {
   if (first_free_ == nullptr) {
     first_block_ = new BlockType(global_handles_, this, first_block_);
+    blocks_++;
     PutNodesOnFreeList(first_block_);
   }
   DCHECK_NOT_NULL(first_free_);
@@ -221,7 +227,7 @@ NodeType* GlobalHandles::NodeSpace<NodeType>::Acquire(Object object) {
     block->ListAdd(&first_used_block_);
   }
   global_handles_->isolate()->counters()->global_handles()->Increment();
-  global_handles_->handles_count_++;
+  handles_count_++;
   DCHECK(node->IsInUse());
   return node;
 }
@@ -253,7 +259,7 @@ void GlobalHandles::NodeSpace<NodeType>::Free(NodeType* node) {
     block->ListRemove(&first_used_block_);
   }
   global_handles_->isolate()->counters()->global_handles()->Decrement();
-  global_handles_->handles_count_--;
+  handles_count_--;
 }
 
 template <class Child>
@@ -875,6 +881,19 @@ size_t GlobalHandles::NumberOfOnStackHandlesForTesting() {
   return on_stack_nodes_->NumberOfHandlesForTesting();
 }
 
+size_t GlobalHandles::TotalSize() const {
+  return regular_nodes_->TotalSize() + traced_nodes_->TotalSize();
+}
+
+size_t GlobalHandles::UsedSize() const {
+  return regular_nodes_->handles_count() * sizeof(Node) +
+         traced_nodes_->handles_count() * sizeof(TracedNode);
+}
+
+size_t GlobalHandles::handles_count() const {
+  return regular_nodes_->handles_count() + traced_nodes_->handles_count();
+}
+
 void GlobalHandles::SetStackStart(void* stack_start) {
   on_stack_nodes_->SetStackStart(stack_start);
 }
@@ -1232,7 +1251,6 @@ void GlobalHandles::IterateYoungStrongAndDependentRoots(RootVisitor* v) {
       v->VisitRootPointer(Root::kGlobalHandles, nullptr, node->location());
     }
   }
-  on_stack_nodes_->Iterate(v);
 }
 
 void GlobalHandles::MarkYoungWeakUnmodifiedObjectsPending(
@@ -1517,6 +1535,9 @@ void GlobalHandles::IterateStrongRoots(RootVisitor* v) {
                           node->location());
     }
   }
+}
+
+void GlobalHandles::IterateStrongStackRoots(RootVisitor* v) {
   on_stack_nodes_->Iterate(v);
 }
 
diff --git a/deps/v8/src/handles/global-handles.h b/deps/v8/src/handles/global-handles.h
index e2e733d8f2..de08007d22 100644
--- a/deps/v8/src/handles/global-handles.h
+++ b/deps/v8/src/handles/global-handles.h
@@ -121,6 +121,7 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
       GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags);
 
   void IterateStrongRoots(RootVisitor* v);
+  void IterateStrongStackRoots(RootVisitor* v);
   void IterateWeakRoots(RootVisitor* v);
   void IterateAllRoots(RootVisitor* v);
   void IterateAllYoungRoots(RootVisitor* v);
@@ -175,8 +176,11 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
 
   Isolate* isolate() const { return isolate_; }
 
+  size_t TotalSize() const;
+  size_t UsedSize() const;
+
   // Number of global handles.
-  size_t handles_count() const { return handles_count_; }
+  size_t handles_count() const;
 
   size_t GetAndResetGlobalHandleResetCount() {
     size_t old = number_of_phantom_handle_resets_;
@@ -236,8 +240,6 @@ class V8_EXPORT_PRIVATE GlobalHandles final {
   std::vector<TracedNode*> traced_young_nodes_;
   std::unique_ptr<OnStackTracedNodeSpace> on_stack_nodes_;
 
-  // Field always containing the number of handles to global objects.
-  size_t handles_count_ = 0;
   size_t number_of_phantom_handle_resets_ = 0;
 
   std::vector<std::pair<Node*, PendingPhantomCallback>>
diff --git a/deps/v8/src/handles/handles-inl.h b/deps/v8/src/handles/handles-inl.h
index 0f53edf5d6..c8b4b4556b 100644
--- a/deps/v8/src/handles/handles-inl.h
+++ b/deps/v8/src/handles/handles-inl.h
@@ -6,15 +6,25 @@
 #define V8_HANDLES_HANDLES_INL_H_
 
 #include "src/execution/isolate.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/handles/handles.h"
+#include "src/handles/local-handles-inl.h"
 #include "src/sanitizer/msan.h"
 
 namespace v8 {
 namespace internal {
 
+class LocalHeap;
+
 HandleBase::HandleBase(Address object, Isolate* isolate)
     : location_(HandleScope::GetHandle(isolate, object)) {}
 
+HandleBase::HandleBase(Address object, OffThreadIsolate* isolate)
+    : location_(isolate->NewHandle(object)) {}
+
+HandleBase::HandleBase(Address object, LocalHeap* local_heap)
+    : location_(LocalHandleScope::GetHandle(local_heap, object)) {}
+
 // Allocate a new handle for the object, do not canonicalize.
 
 template <typename T>
@@ -34,33 +44,41 @@ Handle<T>::Handle(T object, Isolate* isolate)
     : HandleBase(object.ptr(), isolate) {}
 
 template <typename T>
+Handle<T>::Handle(T object, OffThreadIsolate* isolate)
+    : HandleBase(object.ptr(), isolate) {}
+
+template <typename T>
+Handle<T>::Handle(T object, LocalHeap* local_heap)
+    : HandleBase(object.ptr(), local_heap) {}
+
+template <typename T>
 V8_INLINE Handle<T> handle(T object, Isolate* isolate) {
   return Handle<T>(object, isolate);
 }
 
-// Convenience overloads for cases where we want to either create a Handle or an
-// OffThreadHandle, depending on whether we have a Factory or an
-// OffThreadFactory.
 template <typename T>
-V8_INLINE Handle<T> handle(T object, Factory* factory) {
-  return factory->MakeHandle<T>(object);
+V8_INLINE Handle<T> handle(T object, OffThreadIsolate* isolate) {
+  return Handle<T>(object, isolate);
 }
+
 template <typename T>
-V8_INLINE OffThreadHandle<T> handle(T object, OffThreadFactory* factory) {
-  // Convienently, we don't actually need the factory to create this handle.
-  return OffThreadHandle<T>(object);
+V8_INLINE Handle<T> handle(T object, LocalHeap* local_heap) {
+  return Handle<T>(object, local_heap);
 }
 
-// Similar convenience overloads for when we already have a Handle, but want
-// either a Handle or an OffThreadHandle.
+// Convenience overloads for when we already have a Handle, but want
+// either a Handle or an Handle.
 template <typename T>
-V8_INLINE Handle<T> handle(Handle<T> handle, Factory* factory) {
+V8_INLINE Handle<T> handle(Handle<T> handle, Isolate* isolate) {
   return handle;
 }
 template <typename T>
-V8_INLINE OffThreadHandle<T> handle(Handle<T> handle,
-                                    OffThreadFactory* factory) {
-  return OffThreadHandle<T>(*handle);
+V8_INLINE Handle<T> handle(Handle<T> handle, OffThreadIsolate* isolate) {
+  return Handle<T>(*handle);
+}
+template <typename T>
+V8_INLINE Handle<T> handle(Handle<T> handle, LocalHeap* local_heap) {
+  return Handle<T>(*handle, local_heap);
 }
 
 template <typename T>
@@ -197,6 +215,13 @@ inline SealHandleScope::~SealHandleScope() {
 
 #endif
 
+template <typename T>
+Handle<T> OffThreadHandleScope::CloseAndEscape(Handle<T> handle_value) {
+  // At the moment, off-thread handle scopes do nothing on close, so we can
+  // safely return the same handle value.
+  return handle_value;
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/handles/handles.cc b/deps/v8/src/handles/handles.cc
index 87c435061e..87cbc6cc40 100644
--- a/deps/v8/src/handles/handles.cc
+++ b/deps/v8/src/handles/handles.cc
@@ -34,6 +34,8 @@ bool HandleBase::IsDereferenceAllowed() const {
   if (object.IsSmi()) return true;
   HeapObject heap_object = HeapObject::cast(object);
   if (IsReadOnlyHeapObject(heap_object)) return true;
+  if (Heap::InOffThreadSpace(heap_object)) return true;
+
   Isolate* isolate = GetIsolateFromWritableObject(heap_object);
   RootIndex root_index;
   if (isolate->roots_table().IsRootHandleLocation(location_, &root_index) &&
diff --git a/deps/v8/src/handles/handles.h b/deps/v8/src/handles/handles.h
index 0c724ad2d9..b90a942df1 100644
--- a/deps/v8/src/handles/handles.h
+++ b/deps/v8/src/handles/handles.h
@@ -12,7 +12,6 @@
 #include "src/base/macros.h"
 #include "src/common/checks.h"
 #include "src/common/globals.h"
-#include "src/handles/factory-handles.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
@@ -22,12 +21,15 @@ namespace internal {
 class DeferredHandles;
 class HandleScopeImplementer;
 class Isolate;
+class LocalHeap;
+class OffThreadIsolate;
 template <typename T>
 class MaybeHandle;
 class Object;
 class OrderedHashMap;
 class OrderedHashSet;
 class OrderedNameDictionary;
+class RootVisitor;
 class SmallOrderedHashMap;
 class SmallOrderedHashSet;
 class SmallOrderedNameDictionary;
@@ -39,6 +41,8 @@ class HandleBase {
  public:
   V8_INLINE explicit HandleBase(Address* location) : location_(location) {}
   V8_INLINE explicit HandleBase(Address object, Isolate* isolate);
+  V8_INLINE explicit HandleBase(Address object, OffThreadIsolate* isolate);
+  V8_INLINE explicit HandleBase(Address object, LocalHeap* local_heap);
 
   // Check if this handle refers to the exact same object as the other handle.
   V8_INLINE bool is_identical_to(const HandleBase that) const {
@@ -99,7 +103,7 @@ class Handle final : public HandleBase {
     T* operator->() { return &object_; }
 
    private:
-    friend class Handle;
+    friend class Handle<T>;
     explicit ObjectRef(T object) : object_(object) {}
 
     T object_;
@@ -119,6 +123,8 @@ class Handle final : public HandleBase {
   }
 
   V8_INLINE Handle(T object, Isolate* isolate);
+  V8_INLINE Handle(T object, OffThreadIsolate* isolate);
+  V8_INLINE Handle(T object, LocalHeap* local_heap);
 
   // Allocate a new handle for the object, do not canonicalize.
   V8_INLINE static Handle<T> New(T object, Isolate* isolate);
@@ -176,119 +182,6 @@ template <typename T>
 inline std::ostream& operator<<(std::ostream& os, Handle<T> handle);
 
 // ----------------------------------------------------------------------------
-// A fake Handle that simply wraps an object reference. This is used for
-// off-thread Objects, where we want a class that behaves like Handle for the
-// purposes of operator->, casting, etc., but isn't a GC root and doesn't
-// require access to the Isolate.
-template <typename T>
-class OffThreadHandle {
- public:
-  OffThreadHandle() = default;
-
-  template <typename U>
-  explicit OffThreadHandle(U obj) : obj_(obj) {}
-
-  // Constructor for handling automatic up casting. We rely on the compiler
-  // making sure that the assignment to obj_ is legitimate.
-  template <typename U>
-  // NOLINTNEXTLINE
-  OffThreadHandle<T>(OffThreadHandle<U> other) : obj_(*other) {}
-
-  T operator*() const { return obj_; }
-  T* operator->() { return &obj_; }
-  const T* operator->() const { return &obj_; }
-
-  template <typename U>
-  static OffThreadHandle<T> cast(OffThreadHandle<U> other) {
-    return OffThreadHandle<T>(T::cast(*other));
-  }
-
-  bool is_null() const {
-    // TODO(leszeks): This will only work for HeapObjects, figure out a way to
-    // make is_null work for Object and Smi too.
-    return obj_.is_null();
-  }
-
-  bool ToHandle(OffThreadHandle<T>* out) {
-    if (is_null()) return false;
-
-    *out = *this;
-    return true;
-  }
-  OffThreadHandle<T> ToHandleChecked() {
-    DCHECK(!is_null());
-    return *this;
-  }
-
- private:
-  T obj_;
-};
-
-// A helper class which wraps an normal or off-thread handle, and returns one
-// or the other depending on the factory type.
-template <typename T>
-class HandleOrOffThreadHandle {
- public:
-  HandleOrOffThreadHandle() = default;
-
-  template <typename U>
-  HandleOrOffThreadHandle(Handle<U> handle)  // NOLINT
-      : value_(bit_cast<Address>(static_cast<Handle<T>>(handle).location())) {
-#ifdef DEBUG
-    which_ = kHandle;
-#endif
-  }
-
-  template <typename U>
-  HandleOrOffThreadHandle(OffThreadHandle<U> handle)  // NOLINT
-      : value_(static_cast<OffThreadHandle<T>>(handle)->ptr()) {
-#ifdef DEBUG
-    which_ = kOffThreadHandle;
-#endif
-  }
-
-  // To minimize the impact of these handles on main-thread callers, we allow
-  // them to implicitly convert to Handles.
-  template <typename U>
-  operator Handle<U>() {
-    return get<class Factory>();
-  }
-
-  template <typename FactoryType>
-  inline FactoryHandle<FactoryType, T> get() {
-    return get_for(Tag<FactoryType>());
-  }
-
-  inline bool is_null() const { return value_ == 0; }
-
-#ifdef DEBUG
-  inline bool is_initialized() { return which_ != kUninitialized; }
-#endif
-
- private:
-  // Tagged overloads because we can't specialize the above getter
-  // without also specializing the class.
-  template <typename FactoryType>
-  struct Tag {};
-
-  V8_INLINE Handle<T> get_for(Tag<class Factory>) {
-    DCHECK_NE(which_, kOffThreadHandle);
-    return Handle<T>(reinterpret_cast<Address*>(value_));
-  }
-  V8_INLINE OffThreadHandle<T> get_for(Tag<class OffThreadFactory>) {
-    DCHECK_NE(which_, kHandle);
-    return OffThreadHandle<T>(T::unchecked_cast(Object(value_)));
-  }
-
-  // Either handle.location() or off_thread_handle->ptr().
-  Address value_;
-
-#ifdef DEBUG
-  enum { kUninitialized, kHandle, kOffThreadHandle } which_;
-#endif
-};
-
-// ----------------------------------------------------------------------------
 // A stack-allocated class that governs a number of local handles.
 // After a handle scope has been created, all local handles will be
 // allocated within that handle scope until either the handle scope is
@@ -474,6 +367,16 @@ struct HandleScopeData final {
   }
 };
 
+class OffThreadHandleScope {
+ public:
+  // Off-thread Handles are allocated in the parse/compile zone, and not
+  // cleared out, so the scope doesn't have to do anything
+  explicit OffThreadHandleScope(OffThreadIsolate* isolate) {}
+
+  template <typename T>
+  inline Handle<T> CloseAndEscape(Handle<T> handle_value);
+};
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/handles/local-handles-inl.h b/deps/v8/src/handles/local-handles-inl.h
new file mode 100644
index 0000000000..8f24385621
--- /dev/null
+++ b/deps/v8/src/handles/local-handles-inl.h
@@ -0,0 +1,61 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HANDLES_LOCAL_HANDLES_INL_H_
+#define V8_HANDLES_LOCAL_HANDLES_INL_H_
+
+#include "src/handles/local-handles.h"
+
+#include "src/sanitizer/msan.h"
+
+namespace v8 {
+namespace internal {
+
+// static
+V8_INLINE Address* LocalHandleScope::GetHandle(LocalHeap* local_heap,
+                                               Address value) {
+  LocalHandles* handles = local_heap->handles();
+  Address* result = handles->scope_.next;
+  if (result == handles->scope_.limit) {
+    result = handles->AddBlock();
+  }
+  DCHECK_LT(result, handles->scope_.limit);
+  handles->scope_.next++;
+  *result = value;
+  return result;
+}
+
+LocalHandleScope::LocalHandleScope(LocalHeap* local_heap) {
+  LocalHandles* handles = local_heap->handles();
+  local_heap_ = local_heap;
+  prev_next_ = handles->scope_.next;
+  prev_limit_ = handles->scope_.limit;
+  handles->scope_.level++;
+}
+
+LocalHandleScope::~LocalHandleScope() {
+  LocalHandles* handles = local_heap_->handles();
+  Address* old_limit = handles->scope_.limit;
+
+  handles->scope_.next = prev_next_;
+  handles->scope_.limit = prev_limit_;
+  handles->scope_.level--;
+
+  if (old_limit != handles->scope_.limit) {
+    handles->RemoveBlocks();
+    old_limit = handles->scope_.limit;
+  }
+
+  // TODO(dinfuehr): Zap handles
+
+  MSAN_ALLOCATED_UNINITIALIZED_MEMORY(
+      handles->scope_.next,
+      static_cast<size_t>(reinterpret_cast<Address>(old_limit) -
+                          reinterpret_cast<Address>(handles->scope_.next)));
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HANDLES_LOCAL_HANDLES_INL_H_
diff --git a/deps/v8/src/handles/local-handles.cc b/deps/v8/src/handles/local-handles.cc
new file mode 100644
index 0000000000..26e4fb596a
--- /dev/null
+++ b/deps/v8/src/handles/local-handles.cc
@@ -0,0 +1,58 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/handles/local-handles.h"
+
+#include "src/api/api.h"
+#include "src/handles/handles.h"
+
+namespace v8 {
+namespace internal {
+
+LocalHandles::LocalHandles() { scope_.Initialize(); }
+
+void LocalHandles::Iterate(RootVisitor* visitor) {
+  for (int i = 0; i < static_cast<int>(blocks_.size()) - 1; i++) {
+    Address* block = blocks_[i];
+    visitor->VisitRootPointers(Root::kHandleScope, nullptr,
+                               FullObjectSlot(block),
+                               FullObjectSlot(&block[kHandleBlockSize]));
+  }
+
+  if (!blocks_.empty()) {
+    Address* block = blocks_.back();
+    visitor->VisitRootPointers(Root::kHandleScope, nullptr,
+                               FullObjectSlot(block),
+                               FullObjectSlot(scope_.next));
+  }
+}
+
+Address* LocalHandles::AddBlock() {
+  DCHECK_EQ(scope_.next, scope_.limit);
+  Address* block = NewArray<Address>(kHandleBlockSize);
+  blocks_.push_back(block);
+  scope_.next = block;
+  scope_.limit = block + kHandleBlockSize;
+  return block;
+}
+
+void LocalHandles::RemoveBlocks() {
+  while (!blocks_.empty()) {
+    Address* block_start = blocks_.back();
+    Address* block_limit = block_start + kHandleBlockSize;
+
+    if (block_limit == scope_.limit) {
+      break;
+    }
+
+    blocks_.pop_back();
+
+    // TODO(dinfuehr): Zap handles in block
+
+    DeleteArray(block_start);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/handles/local-handles.h b/deps/v8/src/handles/local-handles.h
new file mode 100644
index 0000000000..561ac65765
--- /dev/null
+++ b/deps/v8/src/handles/local-handles.h
@@ -0,0 +1,57 @@
+// Copyright 2011 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HANDLES_LOCAL_HANDLES_H_
+#define V8_HANDLES_LOCAL_HANDLES_H_
+
+#include "include/v8-internal.h"
+#include "src/base/functional.h"
+#include "src/base/macros.h"
+#include "src/handles/handles.h"
+#include "src/heap/local-heap.h"
+
+namespace v8 {
+namespace internal {
+
+class RootVisitor;
+
+class LocalHandles {
+ public:
+  LocalHandles();
+
+  void Iterate(RootVisitor* visitor);
+
+ private:
+  HandleScopeData scope_;
+  std::vector<Address*> blocks_;
+
+  V8_EXPORT_PRIVATE Address* AddBlock();
+  V8_EXPORT_PRIVATE void RemoveBlocks();
+
+  friend class LocalHandleScope;
+};
+
+class LocalHandleScope {
+ public:
+  explicit inline LocalHandleScope(LocalHeap* local_heap);
+  inline ~LocalHandleScope();
+
+  V8_INLINE static Address* GetHandle(LocalHeap* local_heap, Address value);
+
+ private:
+  // Prevent heap allocation or illegal handle scopes.
+  void* operator new(size_t size);
+  void operator delete(void* size_t);
+
+  LocalHeap* local_heap_;
+  Address* prev_limit_;
+  Address* prev_next_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocalHandleScope);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HANDLES_LOCAL_HANDLES_H_
diff --git a/deps/v8/src/handles/maybe-handles.h b/deps/v8/src/handles/maybe-handles.h
index 0b93bf82ea..d804374088 100644
--- a/deps/v8/src/handles/maybe-handles.h
+++ b/deps/v8/src/handles/maybe-handles.h
@@ -12,6 +12,10 @@
 namespace v8 {
 namespace internal {
 
+struct NullMaybeHandleType {};
+
+constexpr NullMaybeHandleType kNullMaybeHandle;
+
 // ----------------------------------------------------------------------------
 // A Handle can be converted into a MaybeHandle. Converting a MaybeHandle
 // into a Handle requires checking that it does not point to nullptr.  This
@@ -25,6 +29,8 @@ class MaybeHandle final {
  public:
   V8_INLINE MaybeHandle() = default;
 
+  V8_INLINE MaybeHandle(NullMaybeHandleType) {}
+
   // Constructor for handling automatic up casting from Handle.
   // Ex. Handle<JSArray> can be passed when MaybeHandle<Object> is expected.
   template <typename S, typename = typename std::enable_if<
@@ -50,7 +56,7 @@ class MaybeHandle final {
 
   // Convert to a Handle with a type that can be upcasted to.
   template <typename S>
-  V8_INLINE bool ToHandle(Handle<S>* out) const {
+  V8_WARN_UNUSED_RESULT V8_INLINE bool ToHandle(Handle<S>* out) const {
     if (location_ == nullptr) {
       *out = Handle<T>::null();
       return false;
diff --git a/deps/v8/src/heap/OWNERS b/deps/v8/src/heap/OWNERS
index c5ceee075f..5a02732930 100644
--- a/deps/v8/src/heap/OWNERS
+++ b/deps/v8/src/heap/OWNERS
@@ -1,6 +1,10 @@
+bikineev@chromium.org
 dinfuehr@chromium.org
 hpayer@chromium.org
 mlippautz@chromium.org
+omerkatz@chromium.org
 ulan@chromium.org
 
+per-file *factory*=leszeks@chromium.org
+
 # COMPONENT: Blink>JavaScript>GC
diff --git a/deps/v8/src/heap/array-buffer-sweeper.cc b/deps/v8/src/heap/array-buffer-sweeper.cc
index d11b08932c..9401db11d5 100644
--- a/deps/v8/src/heap/array-buffer-sweeper.cc
+++ b/deps/v8/src/heap/array-buffer-sweeper.cc
@@ -21,6 +21,7 @@ void ArrayBufferList::Append(ArrayBufferExtension* extension) {
     tail_ = extension;
   }
 
+  bytes_ += extension->accounting_length();
   extension->set_next(nullptr);
 }
 
@@ -37,6 +38,7 @@ void ArrayBufferList::Append(ArrayBufferList* list) {
     DCHECK_NULL(list->tail_);
   }
 
+  bytes_ += list->Bytes();
   list->Reset();
 }
 
@@ -51,22 +53,35 @@ bool ArrayBufferList::Contains(ArrayBufferExtension* extension) {
   return false;
 }
 
+size_t ArrayBufferList::BytesSlow() {
+  ArrayBufferExtension* current = head_;
+  size_t sum = 0;
+
+  while (current) {
+    sum += current->accounting_length();
+    current = current->next();
+  }
+
+  return sum;
+}
+
 void ArrayBufferSweeper::EnsureFinished() {
   if (!sweeping_in_progress_) return;
+  CHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
 
   TryAbortResult abort_result =
       heap_->isolate()->cancelable_task_manager()->TryAbort(job_.id);
 
   switch (abort_result) {
     case TryAbortResult::kTaskAborted: {
-      job_.Sweep();
+      Sweep();
       Merge();
       break;
     }
 
     case TryAbortResult::kTaskRemoved: {
       CHECK_NE(job_.state, SweepingState::Uninitialized);
-      if (job_.state == SweepingState::Prepared) job_.Sweep();
+      if (job_.state == SweepingState::Prepared) Sweep();
       Merge();
       break;
     }
@@ -86,9 +101,25 @@ void ArrayBufferSweeper::EnsureFinished() {
       UNREACHABLE();
   }
 
+  DecrementExternalMemoryCounters();
   sweeping_in_progress_ = false;
 }
 
+void ArrayBufferSweeper::DecrementExternalMemoryCounters() {
+  size_t bytes = freed_bytes_.load(std::memory_order_relaxed);
+  if (bytes == 0) return;
+
+  while (!freed_bytes_.compare_exchange_weak(bytes, 0)) {
+    // empty body
+  }
+
+  if (bytes == 0) return;
+
+  heap_->DecrementExternalBackingStoreBytes(
+      ExternalBackingStoreType::kArrayBuffer, bytes);
+  heap_->update_external_memory(-static_cast<int64_t>(bytes));
+}
+
 void ArrayBufferSweeper::RequestSweepYoung() {
   RequestSweep(SweepingScope::Young);
 }
@@ -97,12 +128,18 @@ void ArrayBufferSweeper::RequestSweepFull() {
   RequestSweep(SweepingScope::Full);
 }
 
+size_t ArrayBufferSweeper::YoungBytes() { return young_bytes_; }
+
+size_t ArrayBufferSweeper::OldBytes() { return old_bytes_; }
+
 void ArrayBufferSweeper::RequestSweep(SweepingScope scope) {
   DCHECK(!sweeping_in_progress_);
 
   if (young_.IsEmpty() && (old_.IsEmpty() || scope == SweepingScope::Young))
     return;
 
+  CHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
+
   if (!heap_->IsTearingDown() && !heap_->ShouldReduceMemory() &&
       FLAG_concurrent_array_buffer_sweeping) {
     Prepare(scope);
@@ -112,7 +149,7 @@ void ArrayBufferSweeper::RequestSweep(SweepingScope scope) {
           heap_->tracer(),
           GCTracer::BackgroundScope::BACKGROUND_ARRAY_BUFFER_SWEEP);
       base::MutexGuard guard(&sweeping_mutex_);
-      job_.Sweep();
+      Sweep();
       job_finished_.NotifyAll();
     });
     job_.id = task->id();
@@ -120,8 +157,9 @@ void ArrayBufferSweeper::RequestSweep(SweepingScope scope) {
     sweeping_in_progress_ = true;
   } else {
     Prepare(scope);
-    job_.Sweep();
+    Sweep();
     Merge();
+    DecrementExternalMemoryCounters();
   }
 }
 
@@ -144,6 +182,8 @@ void ArrayBufferSweeper::Merge() {
   CHECK_EQ(job_.state, SweepingState::Swept);
   young_.Append(&job_.young);
   old_.Append(&job_.old);
+  young_bytes_ = young_.Bytes();
+  old_bytes_ = old_.Bytes();
   job_.state = SweepingState::Uninitialized;
 }
 
@@ -151,6 +191,7 @@ void ArrayBufferSweeper::ReleaseAll() {
   EnsureFinished();
   ReleaseAll(&old_);
   ReleaseAll(&young_);
+  old_bytes_ = young_bytes_ = 0;
 }
 
 void ArrayBufferSweeper::ReleaseAll(ArrayBufferList* list) {
@@ -167,11 +208,26 @@ void ArrayBufferSweeper::ReleaseAll(ArrayBufferList* list) {
 
 void ArrayBufferSweeper::Append(JSArrayBuffer object,
                                 ArrayBufferExtension* extension) {
+  CHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
+  size_t bytes = extension->accounting_length();
+
   if (Heap::InYoungGeneration(object)) {
     young_.Append(extension);
+    young_bytes_ += bytes;
   } else {
     old_.Append(extension);
+    old_bytes_ += bytes;
   }
+
+  DecrementExternalMemoryCounters();
+  IncrementExternalMemoryCounters(bytes);
+}
+
+void ArrayBufferSweeper::IncrementExternalMemoryCounters(size_t bytes) {
+  heap_->IncrementExternalBackingStoreBytes(
+      ExternalBackingStoreType::kArrayBuffer, bytes);
+  reinterpret_cast<v8::Isolate*>(heap_->isolate())
+      ->AdjustAmountOfExternalAllocatedMemory(static_cast<int64_t>(bytes));
 }
 
 ArrayBufferSweeper::SweepingJob::SweepingJob()
@@ -188,52 +244,53 @@ ArrayBufferSweeper::SweepingJob ArrayBufferSweeper::SweepingJob::Prepare(
   return job;
 }
 
-void ArrayBufferSweeper::SweepingJob::Sweep() {
-  CHECK_EQ(state, SweepingState::Prepared);
+void ArrayBufferSweeper::Sweep() {
+  CHECK_EQ(job_.state, SweepingState::Prepared);
 
-  if (scope == SweepingScope::Young) {
+  if (job_.scope == SweepingScope::Young) {
     SweepYoung();
   } else {
-    CHECK_EQ(scope, SweepingScope::Full);
+    CHECK_EQ(job_.scope, SweepingScope::Full);
     SweepFull();
   }
-  state = SweepingState::Swept;
+  job_.state = SweepingState::Swept;
 }
 
-void ArrayBufferSweeper::SweepingJob::SweepFull() {
-  CHECK_EQ(scope, SweepingScope::Full);
-  ArrayBufferList promoted = SweepListFull(&young);
-  ArrayBufferList survived = SweepListFull(&old);
+void ArrayBufferSweeper::SweepFull() {
+  CHECK_EQ(job_.scope, SweepingScope::Full);
+  ArrayBufferList promoted = SweepListFull(&job_.young);
+  ArrayBufferList survived = SweepListFull(&job_.old);
 
-  old = promoted;
-  old.Append(&survived);
+  job_.old = promoted;
+  job_.old.Append(&survived);
 }
 
-ArrayBufferList ArrayBufferSweeper::SweepingJob::SweepListFull(
-    ArrayBufferList* list) {
+ArrayBufferList ArrayBufferSweeper::SweepListFull(ArrayBufferList* list) {
   ArrayBufferExtension* current = list->head_;
-  ArrayBufferList survived;
+  ArrayBufferList survivor_list;
 
   while (current) {
     ArrayBufferExtension* next = current->next();
 
     if (!current->IsMarked()) {
+      size_t bytes = current->accounting_length();
       delete current;
+      IncrementFreedBytes(bytes);
     } else {
       current->Unmark();
-      survived.Append(current);
+      survivor_list.Append(current);
     }
 
     current = next;
   }
 
   list->Reset();
-  return survived;
+  return survivor_list;
 }
 
-void ArrayBufferSweeper::SweepingJob::SweepYoung() {
-  CHECK_EQ(scope, SweepingScope::Young);
-  ArrayBufferExtension* current = young.head_;
+void ArrayBufferSweeper::SweepYoung() {
+  CHECK_EQ(job_.scope, SweepingScope::Young);
+  ArrayBufferExtension* current = job_.young.head_;
 
   ArrayBufferList new_young;
   ArrayBufferList new_old;
@@ -242,7 +299,9 @@ void ArrayBufferSweeper::SweepingJob::SweepYoung() {
     ArrayBufferExtension* next = current->next();
 
     if (!current->IsYoungMarked()) {
+      size_t bytes = current->accounting_length();
       delete current;
+      IncrementFreedBytes(bytes);
     } else if (current->IsYoungPromoted()) {
       current->YoungUnmark();
       new_old.Append(current);
@@ -254,8 +313,13 @@ void ArrayBufferSweeper::SweepingJob::SweepYoung() {
     current = next;
   }
 
-  old = new_old;
-  young = new_young;
+  job_.old = new_old;
+  job_.young = new_young;
+}
+
+void ArrayBufferSweeper::IncrementFreedBytes(size_t bytes) {
+  if (bytes == 0) return;
+  freed_bytes_.fetch_add(bytes);
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/array-buffer-sweeper.h b/deps/v8/src/heap/array-buffer-sweeper.h
index a2605a43d2..5cedb2b8f8 100644
--- a/deps/v8/src/heap/array-buffer-sweeper.h
+++ b/deps/v8/src/heap/array-buffer-sweeper.h
@@ -18,17 +18,24 @@ class Heap;
 // Singly linked-list of ArrayBufferExtensions that stores head and tail of the
 // list to allow for concatenation of lists.
 struct ArrayBufferList {
-  ArrayBufferList() : head_(nullptr), tail_(nullptr) {}
+  ArrayBufferList() : head_(nullptr), tail_(nullptr), bytes_(0) {}
 
   ArrayBufferExtension* head_;
   ArrayBufferExtension* tail_;
+  size_t bytes_;
 
   bool IsEmpty() {
     DCHECK_IMPLIES(head_, tail_);
     return head_ == nullptr;
   }
 
-  void Reset() { head_ = tail_ = nullptr; }
+  size_t Bytes() { return bytes_; }
+  size_t BytesSlow();
+
+  void Reset() {
+    head_ = tail_ = nullptr;
+    bytes_ = 0;
+  }
 
   void Append(ArrayBufferExtension* extension);
   void Append(ArrayBufferList* list);
@@ -41,7 +48,11 @@ struct ArrayBufferList {
 class ArrayBufferSweeper {
  public:
   explicit ArrayBufferSweeper(Heap* heap)
-      : heap_(heap), sweeping_in_progress_(false) {}
+      : heap_(heap),
+        sweeping_in_progress_(false),
+        freed_bytes_(0),
+        young_bytes_(0),
+        old_bytes_(0) {}
   ~ArrayBufferSweeper() { ReleaseAll(); }
 
   void EnsureFinished();
@@ -53,6 +64,9 @@ class ArrayBufferSweeper {
   ArrayBufferList young() { return young_; }
   ArrayBufferList old() { return old_; }
 
+  size_t YoungBytes();
+  size_t OldBytes();
+
  private:
   enum class SweepingScope { Young, Full };
 
@@ -67,20 +81,24 @@ class ArrayBufferSweeper {
 
     SweepingJob();
 
-    void Sweep();
-    void SweepYoung();
-    void SweepFull();
-    ArrayBufferList SweepListFull(ArrayBufferList* list);
     static SweepingJob Prepare(ArrayBufferList young, ArrayBufferList old,
                                SweepingScope scope);
   } job_;
 
   void Merge();
 
+  void DecrementExternalMemoryCounters();
+  void IncrementExternalMemoryCounters(size_t bytes);
+  void IncrementFreedBytes(size_t bytes);
+
   void RequestSweep(SweepingScope sweeping_task);
   void Prepare(SweepingScope sweeping_task);
 
+  void Sweep();
+  void SweepYoung();
+  void SweepFull();
   ArrayBufferList SweepListFull(ArrayBufferList* list);
+
   ArrayBufferList SweepYoungGen();
   void SweepOldGen(ArrayBufferExtension* extension);
 
@@ -91,9 +109,13 @@ class ArrayBufferSweeper {
   bool sweeping_in_progress_;
   base::Mutex sweeping_mutex_;
   base::ConditionVariable job_finished_;
+  std::atomic<size_t> freed_bytes_;
 
   ArrayBufferList young_;
   ArrayBufferList old_;
+
+  size_t young_bytes_;
+  size_t old_bytes_;
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/array-buffer-tracker-inl.h b/deps/v8/src/heap/array-buffer-tracker-inl.h
index 63d4147d41..b2d1115cba 100644
--- a/deps/v8/src/heap/array-buffer-tracker-inl.h
+++ b/deps/v8/src/heap/array-buffer-tracker-inl.h
@@ -20,14 +20,6 @@
 namespace v8 {
 namespace internal {
 
-inline size_t PerIsolateAccountingLength(JSArrayBuffer buffer) {
-  // TODO(titzer): SharedArrayBuffers and shared WasmMemorys cause problems with
-  // accounting for per-isolate external memory. In particular, sharing the same
-  // array buffer or memory multiple times, which happens in stress tests, can
-  // cause overcounting, leading to GC thrashing. Fix with global accounting?
-  return buffer.is_shared() ? 0 : buffer.byte_length();
-}
-
 void ArrayBufferTracker::RegisterNew(
     Heap* heap, JSArrayBuffer buffer,
     std::shared_ptr<BackingStore> backing_store) {
@@ -38,6 +30,7 @@ void ArrayBufferTracker::RegisterNew(
   // ArrayBuffer tracking works only for small objects.
   DCHECK(!heap->IsLargeObject(buffer));
   DCHECK_EQ(backing_store->buffer_start(), buffer.backing_store());
+  const size_t length = backing_store->PerIsolateAccountingLength();
 
   Page* page = Page::FromHeapObject(buffer);
   {
@@ -57,7 +50,6 @@ void ArrayBufferTracker::RegisterNew(
   // TODO(wez): Remove backing-store from external memory accounting.
   // We may go over the limit of externally allocated memory here. We call the
   // api function to trigger a GC in this case.
-  const size_t length = PerIsolateAccountingLength(buffer);
   reinterpret_cast<v8::Isolate*>(heap->isolate())
       ->AdjustAmountOfExternalAllocatedMemory(length);
 }
@@ -66,7 +58,6 @@ std::shared_ptr<BackingStore> ArrayBufferTracker::Unregister(
     Heap* heap, JSArrayBuffer buffer) {
   std::shared_ptr<BackingStore> backing_store;
 
-  const size_t length = PerIsolateAccountingLength(buffer);
   Page* page = Page::FromHeapObject(buffer);
   {
     base::MutexGuard guard(page->mutex());
@@ -76,6 +67,7 @@ std::shared_ptr<BackingStore> ArrayBufferTracker::Unregister(
   }
 
   // TODO(wez): Remove backing-store from external memory accounting.
+  const size_t length = backing_store->PerIsolateAccountingLength();
   heap->update_external_memory(-static_cast<intptr_t>(length));
   return backing_store;
 }
@@ -98,7 +90,7 @@ void LocalArrayBufferTracker::Free(Callback should_free) {
        it != array_buffers_.end();) {
     // Unchecked cast because the map might already be dead at this point.
     JSArrayBuffer buffer = JSArrayBuffer::unchecked_cast(it->first);
-    const size_t length = PerIsolateAccountingLength(buffer);
+    const size_t length = it->second->PerIsolateAccountingLength();
 
     if (should_free(buffer)) {
       // Destroy the shared pointer, (perhaps) freeing the backing store.
@@ -135,7 +127,7 @@ void ArrayBufferTracker::FreeDead(Page* page, MarkingState* marking_state) {
 
 void LocalArrayBufferTracker::Add(JSArrayBuffer buffer,
                                   std::shared_ptr<BackingStore> backing_store) {
-  auto length = PerIsolateAccountingLength(buffer);
+  auto length = backing_store->PerIsolateAccountingLength();
   page_->IncrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, length);
 
@@ -169,7 +161,7 @@ std::shared_ptr<BackingStore> LocalArrayBufferTracker::Remove(
   array_buffers_.erase(it);
 
   // Update accounting.
-  auto length = PerIsolateAccountingLength(buffer);
+  auto length = backing_store->PerIsolateAccountingLength();
   page_->DecrementExternalBackingStoreBytes(
       ExternalBackingStoreType::kArrayBuffer, length);
 
diff --git a/deps/v8/src/heap/array-buffer-tracker.cc b/deps/v8/src/heap/array-buffer-tracker.cc
index b284a65f66..e79f86942f 100644
--- a/deps/v8/src/heap/array-buffer-tracker.cc
+++ b/deps/v8/src/heap/array-buffer-tracker.cc
@@ -50,7 +50,7 @@ void LocalArrayBufferTracker::Process(Callback callback) {
           tracker = target_page->local_tracker();
         }
         DCHECK_NOT_NULL(tracker);
-        const size_t length = PerIsolateAccountingLength(old_buffer);
+        const size_t length = it->second->PerIsolateAccountingLength();
         // We should decrement before adding to avoid potential overflows in
         // the external memory counters.
         tracker->AddInternal(new_buffer, std::move(it->second));
@@ -60,8 +60,8 @@ void LocalArrayBufferTracker::Process(Callback callback) {
             static_cast<MemoryChunk*>(target_page), length);
       }
     } else if (result == kRemoveEntry) {
-      freed_memory += PerIsolateAccountingLength(old_buffer);
       auto backing_store = std::move(it->second);
+      freed_memory += backing_store->PerIsolateAccountingLength();
       TRACE_BS("ABT:queue bs=%p mem=%p (length=%zu) cnt=%ld\n",
                backing_store.get(), backing_store->buffer_start(),
                backing_store->byte_length(), backing_store.use_count());
diff --git a/deps/v8/src/heap/concurrent-marking.cc b/deps/v8/src/heap/concurrent-marking.cc
index 9bed247194..562719c07f 100644
--- a/deps/v8/src/heap/concurrent-marking.cc
+++ b/deps/v8/src/heap/concurrent-marking.cc
@@ -524,7 +524,7 @@ void ConcurrentMarking::ScheduleTasks() {
 #else   // defined(OS_MACOSX)
     // On other platforms use all logical cores, leaving one for the main
     // thread.
-    total_task_count_ = Max(1, Min(kMaxTasks, num_cores - 1));
+    total_task_count_ = Max(1, Min(kMaxTasks, num_cores - 2));
 #endif  // defined(OS_MACOSX)
     DCHECK_LE(total_task_count_, kMaxTasks);
     // One task is for the main thread.
diff --git a/deps/v8/src/heap/cppgc/allocation.cc b/deps/v8/src/heap/cppgc/allocation.cc
new file mode 100644
index 0000000000..7e98d1eec9
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/allocation.cc
@@ -0,0 +1,23 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/allocation.h"
+
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+#include "src/heap/cppgc/heap-inl.h"
+
+namespace cppgc {
+namespace internal {
+
+// static
+void* MakeGarbageCollectedTraitInternal::Allocate(cppgc::Heap* heap,
+                                                  size_t size,
+                                                  GCInfoIndex index) {
+  DCHECK_NOT_NULL(heap);
+  return Heap::From(heap)->Allocate(size, index);
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/asm/x64/push_registers.S b/deps/v8/src/heap/cppgc/asm/x64/push_registers.S
new file mode 100644
index 0000000000..018859d5c0
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/asm/x64/push_registers.S
@@ -0,0 +1,52 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+.att_syntax
+
+.text
+
+#ifdef V8_TARGET_OS_MACOSX
+
+.globl _PushAllRegistersAndIterateStack
+_PushAllRegistersAndIterateStack:
+
+#else  // !V8_TARGET_OS_MACOSX
+
+.type PushAllRegistersAndIterateStack, %function
+.global PushAllRegistersAndIterateStack
+.hidden PushAllRegistersAndIterateStack
+PushAllRegistersAndIterateStack:
+
+#endif  // !V8_TARGET_OS_MACOSX
+
+    // Push all callee-saved registers to get them on the stack for conservative
+    // stack scanning.
+    //
+    // We maintain 16-byte alignment at calls. There is an 8-byte return address
+    // on the stack and we push 56 bytes which maintains 16-byte stack alignment
+    // at the call.
+    // Source: https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-1.0.pdf
+    //
+    // rbp is callee-saved. Maintain proper frame pointer for debugging.
+    push %rbp
+    mov %rsp, %rbp
+    push $0xCDCDCD  // Dummy for alignment.
+    push %rbx
+    push %r12
+    push %r13
+    push %r14
+    push %r15
+    // Pass 1st parameter (rdi) unchanged (Stack*).
+    // Pass 2nd parameter (rsi) unchanged (StackVisitor*).
+    // Save 3rd parameter (rdx; IterateStackCallback)
+    mov %rdx, %r8
+    // Pass 3rd parameter as rsp (stack pointer).
+    mov %rsp, %rdx
+    // Call the callback.
+    call *%r8
+    // Pop the callee-saved registers.
+    add $48, %rsp
+    // Restore rbp as it was used as frame pointer.
+    pop %rbp
+    ret
diff --git a/deps/v8/src/heap/cppgc/asm/x64/push_registers_win.S b/deps/v8/src/heap/cppgc/asm/x64/push_registers_win.S
new file mode 100644
index 0000000000..627843830f
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/asm/x64/push_registers_win.S
@@ -0,0 +1,45 @@
+;; Copyright 2020 the V8 project authors. All rights reserved.
+;; Use of this source code is governed by a BSD-style license that can be
+;; found in the LICENSE file.
+
+;; MASM syntax
+;; https://docs.microsoft.com/en-us/cpp/assembler/masm/microsoft-macro-assembler-reference?view=vs-2019
+
+public PushAllRegistersAndIterateStack
+
+.code
+PushAllRegistersAndIterateStack:
+    ;; Push all callee-saved registers to get them on the stack for conservative
+    ;; stack scanning.
+    ;;
+    ;; We maintain 16-byte alignment at calls. There is an 8-byte return address
+    ;; on the stack and we push 72 bytes which maintains 16-byte stack alignment
+    ;; at the call.
+    ;; Source: https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention
+    ;;
+    ;; rbp is callee-saved. Maintain proper frame pointer for debugging.
+    push rbp
+    mov rbp, rsp
+    push 0CDCDCDh  ;; Dummy for alignment.
+    push rsi
+    push rdi
+    push rbx
+    push r12
+    push r13
+    push r14
+    push r15
+    ;; Pass 1st parameter (rcx) unchanged (Stack*).
+    ;; Pass 2nd parameter (rdx) unchanged (StackVisitor*).
+    ;; Save 3rd parameter (r8; IterateStackCallback)
+    mov r9, r8
+    ;; Pass 3rd parameter as rsp (stack pointer).
+    mov r8, rsp
+    ;; Call the callback.
+    call r9
+    ;; Pop the callee-saved registers.
+    add rsp, 64
+    ;; Restore rbp as it was used as frame pointer.
+    pop rbp
+    ret
+
+end
diff --git a/deps/v8/src/heap/cppgc/gc-info-table.cc b/deps/v8/src/heap/cppgc/gc-info-table.cc
new file mode 100644
index 0000000000..580ff4d069
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/gc-info-table.cc
@@ -0,0 +1,124 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/gc-info-table.h"
+
+#include <algorithm>
+#include <limits>
+#include <memory>
+
+#include "include/cppgc/gc-info.h"
+#include "include/cppgc/platform.h"
+#include "src/base/bits.h"
+#include "src/base/lazy-instance.h"
+
+namespace cppgc {
+namespace internal {
+
+namespace {
+
+constexpr size_t kEntrySize = sizeof(GCInfo);
+static_assert(v8::base::bits::IsPowerOfTwo(kEntrySize),
+              "GCInfoTable entries size must be power of "
+              "two");
+
+}  // namespace
+
+GCInfoTable* GlobalGCInfoTable::global_table_ = nullptr;
+constexpr GCInfoIndex GCInfoTable::kMaxIndex;
+constexpr GCInfoIndex GCInfoTable::kMinIndex;
+constexpr GCInfoIndex GCInfoTable::kInitialWantedLimit;
+
+void GlobalGCInfoTable::Create(PageAllocator* page_allocator) {
+  static v8::base::LeakyObject<GCInfoTable> table(page_allocator);
+  if (!global_table_) {
+    global_table_ = table.get();
+  }
+}
+
+GCInfoTable::GCInfoTable(PageAllocator* page_allocator)
+    : page_allocator_(page_allocator),
+      table_(static_cast<decltype(table_)>(page_allocator_->AllocatePages(
+          nullptr, MaxTableSize(), page_allocator_->AllocatePageSize(),
+          PageAllocator::kNoAccess))),
+      read_only_table_end_(reinterpret_cast<uint8_t*>(table_)) {
+  CHECK(table_);
+  Resize();
+}
+
+GCInfoTable::~GCInfoTable() {
+  page_allocator_->ReleasePages(const_cast<GCInfo*>(table_), MaxTableSize(), 0);
+}
+
+size_t GCInfoTable::MaxTableSize() const {
+  return RoundUp(GCInfoTable::kMaxIndex * kEntrySize,
+                 page_allocator_->AllocatePageSize());
+}
+
+GCInfoIndex GCInfoTable::InitialTableLimit() const {
+  // Different OSes have different page sizes, so we have to choose the minimum
+  // of memory wanted and OS page size.
+  constexpr size_t memory_wanted = kInitialWantedLimit * kEntrySize;
+  const size_t initial_limit =
+      RoundUp(memory_wanted, page_allocator_->AllocatePageSize()) / kEntrySize;
+  CHECK_GT(std::numeric_limits<GCInfoIndex>::max(), initial_limit);
+  return static_cast<GCInfoIndex>(
+      std::min(static_cast<size_t>(kMaxIndex), initial_limit));
+}
+
+void GCInfoTable::Resize() {
+  const GCInfoIndex new_limit = (limit_) ? 2 * limit_ : InitialTableLimit();
+  CHECK_GT(new_limit, limit_);
+  const size_t old_committed_size = limit_ * kEntrySize;
+  const size_t new_committed_size = new_limit * kEntrySize;
+  CHECK(table_);
+  CHECK_EQ(0u, new_committed_size % page_allocator_->AllocatePageSize());
+  CHECK_GE(MaxTableSize(), new_committed_size);
+  // Recommit new area as read/write.
+  uint8_t* current_table_end =
+      reinterpret_cast<uint8_t*>(table_) + old_committed_size;
+  const size_t table_size_delta = new_committed_size - old_committed_size;
+  CHECK(page_allocator_->SetPermissions(current_table_end, table_size_delta,
+                                        PageAllocator::kReadWrite));
+  // Recommit old area as read-only.
+  if (read_only_table_end_ != current_table_end) {
+    DCHECK_GT(current_table_end, read_only_table_end_);
+    const size_t read_only_delta = current_table_end - read_only_table_end_;
+    CHECK(page_allocator_->SetPermissions(read_only_table_end_, read_only_delta,
+                                          PageAllocator::kRead));
+    read_only_table_end_ += read_only_delta;
+  }
+
+  // Check that newly-committed memory is zero-initialized.
+  CheckMemoryIsZeroed(reinterpret_cast<uintptr_t*>(current_table_end),
+                      table_size_delta / sizeof(uintptr_t));
+
+  limit_ = new_limit;
+}
+
+void GCInfoTable::CheckMemoryIsZeroed(uintptr_t* base, size_t len) {
+#if DEBUG
+  for (size_t i = 0; i < len; ++i) {
+    DCHECK(!base[i]);
+  }
+#endif  // DEBUG
+}
+
+GCInfoIndex GCInfoTable::RegisterNewGCInfo(const GCInfo& info) {
+  // Ensuring a new index involves current index adjustment as well as
+  // potentially resizing the table. For simplicity we use a lock.
+  v8::base::MutexGuard guard(&table_mutex_);
+
+  if (current_index_ == limit_) {
+    Resize();
+  }
+
+  GCInfoIndex new_index = current_index_++;
+  CHECK_LT(new_index, GCInfoTable::kMaxIndex);
+  table_[new_index] = info;
+  return new_index;
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/gc-info-table.h b/deps/v8/src/heap/cppgc/gc-info-table.h
new file mode 100644
index 0000000000..c5ccec2a38
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/gc-info-table.h
@@ -0,0 +1,113 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_GC_INFO_TABLE_H_
+#define V8_HEAP_CPPGC_GC_INFO_TABLE_H_
+
+#include <stdint.h>
+
+#include "include/cppgc/gc-info.h"
+#include "include/cppgc/platform.h"
+#include "include/v8config.h"
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+#include "src/base/platform/mutex.h"
+#include "src/base/platform/platform.h"
+
+namespace cppgc {
+namespace internal {
+
+// GCInfo contains metadata for objects that are instantiated from classes that
+// inherit from GarbageCollected.
+struct GCInfo final {
+  FinalizationCallback finalize;
+  bool has_v_table;
+};
+
+class V8_EXPORT GCInfoTable final {
+ public:
+  // At maximum |kMaxIndex - 1| indices are supported.
+  //
+  // We assume that 14 bits are enough to represent all possible types.
+  //
+  // For Blink during telemetry runs, we see about 1,000 different types;
+  // looking at the output of the Oilpan GC clang plugin, there appear to be at
+  // most about 6,000 types. Thus 14 bits should be more than twice as many bits
+  // as we will ever need. Different contexts may require adjusting this limit.
+  static constexpr GCInfoIndex kMaxIndex = 1 << 14;
+
+  // Minimum index returned. Values smaller |kMinIndex| may be used as
+  // sentinels.
+  static constexpr GCInfoIndex kMinIndex = 1;
+
+  // (Light) experimentation suggests that Blink doesn't need more than this
+  // while handling content on popular web properties.
+  static constexpr GCInfoIndex kInitialWantedLimit = 512;
+
+  // Refer through GlobalGCInfoTable for retrieving the global table outside
+  // of testing code.
+  explicit GCInfoTable(PageAllocator* page_allocator);
+  ~GCInfoTable();
+
+  GCInfoIndex RegisterNewGCInfo(const GCInfo& info);
+
+  const GCInfo& GCInfoFromIndex(GCInfoIndex index) const {
+    DCHECK_GE(index, kMinIndex);
+    DCHECK_LT(index, kMaxIndex);
+    DCHECK(table_);
+    return table_[index];
+  }
+
+  GCInfoIndex NumberOfGCInfosForTesting() const { return current_index_; }
+  GCInfoIndex LimitForTesting() const { return limit_; }
+  GCInfo& TableSlotForTesting(GCInfoIndex index) { return table_[index]; }
+
+ private:
+  void Resize();
+
+  GCInfoIndex InitialTableLimit() const;
+  size_t MaxTableSize() const;
+
+  void CheckMemoryIsZeroed(uintptr_t* base, size_t len);
+
+  PageAllocator* page_allocator_;
+  // Holds the per-class GCInfo descriptors; each HeapObjectHeader keeps an
+  // index into this table.
+  GCInfo* table_;
+  uint8_t* read_only_table_end_;
+  // Current index used when requiring a new GCInfo object.
+  GCInfoIndex current_index_ = kMinIndex;
+  // The limit (exclusive) of the currently allocated table.
+  GCInfoIndex limit_ = 0;
+
+  v8::base::Mutex table_mutex_;
+
+  DISALLOW_COPY_AND_ASSIGN(GCInfoTable);
+};
+
+class V8_EXPORT GlobalGCInfoTable final {
+ public:
+  // Sets up a singleton table that can be acquired using Get().
+  static void Create(PageAllocator* page_allocator);
+
+  // Accessors for the singleton table.
+  static GCInfoTable& GetMutable() { return *global_table_; }
+  static const GCInfoTable& Get() { return *global_table_; }
+
+  static const GCInfo& GCInfoFromIndex(GCInfoIndex index) {
+    return Get().GCInfoFromIndex(index);
+  }
+
+ private:
+  // Singleton for each process. Retrieved through Get().
+  static GCInfoTable* global_table_;
+
+  DISALLOW_NEW_AND_DELETE()
+  DISALLOW_COPY_AND_ASSIGN(GlobalGCInfoTable);
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_GC_INFO_TABLE_H_
diff --git a/deps/v8/src/heap/cppgc/gc-info.cc b/deps/v8/src/heap/cppgc/gc-info.cc
new file mode 100644
index 0000000000..21492825cc
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/gc-info.cc
@@ -0,0 +1,18 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/gc-info.h"
+#include "include/v8config.h"
+#include "src/heap/cppgc/gc-info-table.h"
+
+namespace cppgc {
+namespace internal {
+
+RegisteredGCInfoIndex::RegisteredGCInfoIndex(
+    FinalizationCallback finalization_callback, bool has_v_table)
+    : index_(GlobalGCInfoTable::GetMutable().RegisterNewGCInfo(
+          {finalization_callback, has_v_table})) {}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/globals.h b/deps/v8/src/heap/cppgc/globals.h
new file mode 100644
index 0000000000..18a7e3189e
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/globals.h
@@ -0,0 +1,39 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_GLOBALS_H_
+#define V8_HEAP_CPPGC_GLOBALS_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace cppgc {
+namespace internal {
+
+using Address = uint8_t*;
+using ConstAddress = const uint8_t*;
+
+// See 6.7.6 (http://eel.is/c++draft/basic.align) for alignment restrictions. We
+// do not fully support all alignment restrictions (following
+// alignof(std​::​max_­align_­t)) but limit to alignof(double).
+//
+// This means that any scalar type with stricter alignment requirements (in
+// practice: long double) cannot be used unrestricted in garbage-collected
+// objects.
+//
+// Note: We use the same allocation granularity on 32-bit and 64-bit systems.
+constexpr size_t kAllocationGranularity = 8;
+constexpr size_t kAllocationMask = kAllocationGranularity - 1;
+
+constexpr size_t kPageSizeLog2 = 17;
+constexpr size_t kPageSize = 1 << kPageSizeLog2;
+constexpr size_t kPageOffsetMask = kPageSize - 1;
+constexpr size_t kPageBaseMask = ~kPageOffsetMask;
+
+constexpr size_t kLargeObjectSizeThreshold = kPageSize / 2;
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_GLOBALS_H_
diff --git a/deps/v8/src/heap/cppgc/heap-inl.h b/deps/v8/src/heap/cppgc/heap-inl.h
new file mode 100644
index 0000000000..28a4a14139
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap-inl.h
@@ -0,0 +1,36 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/heap.h"
+
+#include "src/heap/cppgc/globals.h"
+#include "src/heap/cppgc/heap-object-header-inl.h"
+
+#ifndef V8_HEAP_CPPGC_HEAP_INL_H_
+#define V8_HEAP_CPPGC_HEAP_INL_H_
+
+namespace cppgc {
+namespace internal {
+
+void* Heap::Allocate(size_t size, GCInfoIndex index) {
+  // TODO(chromium:1056170): This is merely a dummy implementation and will be
+  // replaced with proper allocation code throughout the migration.
+  size_t allocation_size = size + sizeof(HeapObjectHeader);
+  // The allocation size calculation can overflow for large sizes.
+  CHECK_GT(allocation_size, size);
+  // calloc() provides stricter alignment guarantees than the GC. Allocate
+  // a multiple of kAllocationGranularity to follow restrictions of
+  // HeapObjectHeader.
+  allocation_size = (allocation_size + kAllocationMask) & ~kAllocationMask;
+  void* memory = calloc(1, allocation_size);
+  HeapObjectHeader* header =
+      new (memory) HeapObjectHeader(allocation_size, index);
+  objects_.push_back(header);
+  return header->Payload();
+}
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_HEAP_INL_H_
diff --git a/deps/v8/src/heap/cppgc/heap-object-header-inl.h b/deps/v8/src/heap/cppgc/heap-object-header-inl.h
new file mode 100644
index 0000000000..a0bcda464b
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap-object-header-inl.h
@@ -0,0 +1,148 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_INL_H_
+#define V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_INL_H_
+
+#include "include/cppgc/allocation.h"
+#include "include/cppgc/gc-info.h"
+#include "src/base/atomic-utils.h"
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+#include "src/heap/cppgc/gc-info-table.h"
+#include "src/heap/cppgc/heap-object-header.h"
+
+namespace cppgc {
+namespace internal {
+
+// static
+HeapObjectHeader& HeapObjectHeader::FromPayload(void* payload) {
+  return *reinterpret_cast<HeapObjectHeader*>(static_cast<Address>(payload) -
+                                              sizeof(HeapObjectHeader));
+}
+
+// static
+const HeapObjectHeader& HeapObjectHeader::FromPayload(const void* payload) {
+  return *reinterpret_cast<const HeapObjectHeader*>(
+      static_cast<ConstAddress>(payload) - sizeof(HeapObjectHeader));
+}
+
+HeapObjectHeader::HeapObjectHeader(size_t size, GCInfoIndex gc_info_index) {
+#if defined(V8_TARGET_ARCH_64_BIT)
+  USE(padding_);
+#endif  // defined(V8_TARGET_ARCH_64_BIT)
+  DCHECK_LT(gc_info_index, GCInfoTable::kMaxIndex);
+  DCHECK_EQ(0u, size & kAllocationMask);
+  DCHECK_GE(kMaxSize, size);
+  encoded_high_ = GCInfoIndexField::encode(gc_info_index);
+  encoded_low_ = EncodeSize(size);
+  DCHECK(IsInConstruction());
+#ifdef DEBUG
+  CheckApiConstants();
+#endif  // DEBUG
+}
+
+Address HeapObjectHeader::Payload() const {
+  return reinterpret_cast<Address>(const_cast<HeapObjectHeader*>(this)) +
+         sizeof(HeapObjectHeader);
+}
+
+template <HeapObjectHeader::AccessMode mode>
+GCInfoIndex HeapObjectHeader::GetGCInfoIndex() const {
+  const uint16_t encoded =
+      LoadEncoded<mode, EncodedHalf::kHigh, std::memory_order_acquire>();
+  return GCInfoIndexField::decode(encoded);
+}
+
+template <HeapObjectHeader::AccessMode mode>
+size_t HeapObjectHeader::GetSize() const {
+  // Size is immutable after construction while either marking or sweeping
+  // is running so relaxed load (if mode == kAtomic) is enough.
+  uint16_t encoded_low_value =
+      LoadEncoded<mode, EncodedHalf::kLow, std::memory_order_relaxed>();
+  const size_t size = DecodeSize(encoded_low_value);
+  return size;
+}
+
+void HeapObjectHeader::SetSize(size_t size) {
+  DCHECK(!IsMarked());
+  encoded_low_ |= EncodeSize(size);
+}
+
+template <HeapObjectHeader::AccessMode mode>
+bool HeapObjectHeader::IsLargeObject() const {
+  return GetSize<mode>() == kLargeObjectSizeInHeader;
+}
+
+template <HeapObjectHeader::AccessMode mode>
+bool HeapObjectHeader::IsInConstruction() const {
+  const uint16_t encoded =
+      LoadEncoded<mode, EncodedHalf::kHigh, std::memory_order_acquire>();
+  return !FullyConstructedField::decode(encoded);
+}
+
+void HeapObjectHeader::MarkAsFullyConstructed() {
+  MakeGarbageCollectedTraitInternal::MarkObjectAsFullyConstructed(Payload());
+}
+
+template <HeapObjectHeader::AccessMode mode>
+bool HeapObjectHeader::IsMarked() const {
+  const uint16_t encoded =
+      LoadEncoded<mode, EncodedHalf::kLow, std::memory_order_relaxed>();
+  return MarkBitField::decode(encoded);
+}
+
+template <HeapObjectHeader::AccessMode mode>
+void HeapObjectHeader::Unmark() {
+  DCHECK(IsMarked<mode>());
+  StoreEncoded<mode, EncodedHalf::kLow, std::memory_order_relaxed>(
+      MarkBitField::encode(false), MarkBitField::kMask);
+}
+
+bool HeapObjectHeader::TryMarkAtomic() {
+  auto* atomic_encoded = v8::base::AsAtomicPtr(&encoded_low_);
+  uint16_t old_value = atomic_encoded->load(std::memory_order_relaxed);
+  const uint16_t new_value = old_value | MarkBitField::encode(true);
+  if (new_value == old_value) {
+    return false;
+  }
+  return atomic_encoded->compare_exchange_strong(old_value, new_value,
+                                                 std::memory_order_relaxed);
+}
+
+template <HeapObjectHeader::AccessMode mode, HeapObjectHeader::EncodedHalf part,
+          std::memory_order memory_order>
+uint16_t HeapObjectHeader::LoadEncoded() const {
+  const uint16_t& half =
+      part == EncodedHalf::kLow ? encoded_low_ : encoded_high_;
+  if (mode == AccessMode::kNonAtomic) return half;
+  return v8::base::AsAtomicPtr(&half)->load(memory_order);
+}
+
+template <HeapObjectHeader::AccessMode mode, HeapObjectHeader::EncodedHalf part,
+          std::memory_order memory_order>
+void HeapObjectHeader::StoreEncoded(uint16_t bits, uint16_t mask) {
+  // Caveat: Not all changes to HeapObjectHeader's bitfields go through
+  // StoreEncoded. The following have their own implementations and need to be
+  // kept in sync:
+  // - HeapObjectHeader::TryMarkAtomic
+  // - MarkObjectAsFullyConstructed (API)
+  DCHECK_EQ(0u, bits & ~mask);
+  uint16_t& half = part == EncodedHalf::kLow ? encoded_low_ : encoded_high_;
+  if (mode == AccessMode::kNonAtomic) {
+    half = (half & ~mask) | bits;
+    return;
+  }
+  // We don't perform CAS loop here assuming that only none of the info that
+  // shares the same encoded halfs change at the same time.
+  auto* atomic_encoded = v8::base::AsAtomicPtr(&half);
+  uint16_t value = atomic_encoded->load(std::memory_order_relaxed);
+  value = (value & ~mask) | bits;
+  atomic_encoded->store(value, memory_order);
+}
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_INL_H_
diff --git a/deps/v8/src/heap/cppgc/heap-object-header.cc b/deps/v8/src/heap/cppgc/heap-object-header.cc
new file mode 100644
index 0000000000..bd90d5930c
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap-object-header.cc
@@ -0,0 +1,30 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/heap-object-header.h"
+
+#include "include/cppgc/internals.h"
+#include "src/base/macros.h"
+#include "src/heap/cppgc/gc-info-table.h"
+#include "src/heap/cppgc/heap-object-header-inl.h"
+
+namespace cppgc {
+namespace internal {
+
+void HeapObjectHeader::CheckApiConstants() {
+  STATIC_ASSERT(api_constants::kFullyConstructedBitMask ==
+                FullyConstructedField::kMask);
+  STATIC_ASSERT(api_constants::kFullyConstructedBitFieldOffsetFromPayload ==
+                (sizeof(encoded_high_) + sizeof(encoded_low_)));
+}
+
+void HeapObjectHeader::Finalize() {
+  const GCInfo& gc_info = GlobalGCInfoTable::GCInfoFromIndex(GetGCInfoIndex());
+  if (gc_info.finalize) {
+    gc_info.finalize(Payload());
+  }
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/heap-object-header.h b/deps/v8/src/heap/cppgc/heap-object-header.h
new file mode 100644
index 0000000000..738f9d9ab9
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap-object-header.h
@@ -0,0 +1,127 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_H_
+#define V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_H_
+
+#include <stdint.h>
+#include <atomic>
+
+#include "include/cppgc/gc-info.h"
+#include "src/base/bit-field.h"
+#include "src/heap/cppgc/globals.h"
+
+namespace cppgc {
+namespace internal {
+
+// HeapObjectHeader contains meta data per object and is prepended to each
+// object.
+//
+// +-----------------+------+------------------------------------------+
+// | name            | bits |                                          |
+// +-----------------+------+------------------------------------------+
+// | padding         |   32 | Only present on 64-bit platform.         |
+// +-----------------+------+------------------------------------------+
+// | GCInfoIndex     |   14 |                                          |
+// | unused          |    1 |                                          |
+// | in construction |    1 | In construction encoded as |false|.      |
+// +-----------------+------+------------------------------------------+
+// | size            |   14 | 17 bits because allocations are aligned. |
+// | unused          |    1 |                                          |
+// | mark bit        |    1 |                                          |
+// +-----------------+------+------------------------------------------+
+//
+// Notes:
+// - See |GCInfoTable| for constraints on GCInfoIndex.
+// - |size| for regular objects is encoded with 14 bits but can actually
+//   represent sizes up to |kBlinkPageSize| (2^17) because allocations are
+//   always 8 byte aligned (see kAllocationGranularity).
+// - |size| for large objects is encoded as 0. The size of a large object is
+//   stored in |LargeObjectPage::PayloadSize()|.
+// - |mark bit| and |in construction| bits are located in separate 16-bit halves
+//    to allow potentially accessing them non-atomically.
+class HeapObjectHeader final {
+ public:
+  enum class AccessMode : uint8_t { kNonAtomic, kAtomic };
+
+  static constexpr size_t kSizeLog2 = 17;
+  static constexpr size_t kMaxSize = (size_t{1} << kSizeLog2) - 1;
+
+  inline static HeapObjectHeader& FromPayload(void* address);
+  inline static const HeapObjectHeader& FromPayload(const void* address);
+
+  inline HeapObjectHeader(size_t size, GCInfoIndex gc_info_index);
+
+  // The payload starts directly after the HeapObjectHeader.
+  inline Address Payload() const;
+
+  template <AccessMode mode = AccessMode::kNonAtomic>
+  inline GCInfoIndex GetGCInfoIndex() const;
+
+  template <AccessMode mode = AccessMode::kNonAtomic>
+  inline size_t GetSize() const;
+  inline void SetSize(size_t size);
+
+  template <AccessMode mode = AccessMode::kNonAtomic>
+  inline bool IsLargeObject() const;
+
+  template <AccessMode = AccessMode::kNonAtomic>
+  bool IsInConstruction() const;
+  inline void MarkAsFullyConstructed();
+  // Use MarkObjectAsFullyConstructed() to mark an object as being constructed.
+
+  template <AccessMode = AccessMode::kNonAtomic>
+  bool IsMarked() const;
+  template <AccessMode = AccessMode::kNonAtomic>
+  void Unmark();
+  inline bool TryMarkAtomic();
+
+  void Finalize();
+
+ private:
+  enum class EncodedHalf : uint8_t { kLow, kHigh };
+
+  static constexpr uint16_t kLargeObjectSizeInHeader = 0;
+
+  // Used in |encoded_high_|.
+  using FullyConstructedField = v8::base::BitField16<bool, 0, 1>;
+  using UnusedField1 = FullyConstructedField::Next<bool, 1>;
+  using GCInfoIndexField = UnusedField1::Next<GCInfoIndex, 14>;
+  // Used in |encoded_low_|.
+  using MarkBitField = v8::base::BitField16<bool, 0, 1>;
+  using UnusedField2 = MarkBitField::Next<bool, 1>;
+  using SizeField = void;  // Use EncodeSize/DecodeSize instead.
+
+  static constexpr size_t DecodeSize(uint16_t encoded) {
+    // Essentially, gets optimized to << 1.
+    using SizeField = UnusedField2::Next<size_t, 14>;
+    return SizeField::decode(encoded) * kAllocationGranularity;
+  }
+
+  static constexpr uint16_t EncodeSize(size_t size) {
+    // Essentially, gets optimized to >> 1.
+    using SizeField = UnusedField2::Next<size_t, 14>;
+    return SizeField::encode(size) / kAllocationGranularity;
+  }
+
+  V8_EXPORT_PRIVATE void CheckApiConstants();
+
+  template <AccessMode, EncodedHalf part,
+            std::memory_order memory_order = std::memory_order_seq_cst>
+  inline uint16_t LoadEncoded() const;
+  template <AccessMode mode, EncodedHalf part,
+            std::memory_order memory_order = std::memory_order_seq_cst>
+  inline void StoreEncoded(uint16_t bits, uint16_t mask);
+
+#if defined(V8_TARGET_ARCH_64_BIT)
+  uint32_t padding_ = 0;
+#endif  // defined(V8_TARGET_ARCH_64_BIT)
+  uint16_t encoded_high_;
+  uint16_t encoded_low_;
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_HEAP_OBJECT_HEADER_H_
diff --git a/deps/v8/src/heap/cppgc/heap.cc b/deps/v8/src/heap/cppgc/heap.cc
new file mode 100644
index 0000000000..e60cb15573
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap.cc
@@ -0,0 +1,28 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/heap.h"
+
+#include <memory>
+
+#include "src/heap/cppgc/heap-object-header.h"
+
+namespace cppgc {
+
+std::unique_ptr<Heap> Heap::Create() {
+  return std::make_unique<internal::Heap>();
+}
+
+namespace internal {
+
+void Heap::CollectGarbage() {
+  for (HeapObjectHeader* header : objects_) {
+    header->Finalize();
+    free(header);
+  }
+  objects_.clear();
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/heap.h b/deps/v8/src/heap/cppgc/heap.h
new file mode 100644
index 0000000000..baf70d8f4e
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/heap.h
@@ -0,0 +1,35 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_HEAP_H_
+#define V8_HEAP_CPPGC_HEAP_H_
+
+#include <vector>
+
+#include "include/cppgc/gc-info.h"
+#include "include/cppgc/heap.h"
+#include "src/heap/cppgc/heap-object-header.h"
+
+namespace cppgc {
+namespace internal {
+
+class V8_EXPORT_PRIVATE Heap final : public cppgc::Heap {
+ public:
+  static Heap* From(cppgc::Heap* heap) { return static_cast<Heap*>(heap); }
+
+  Heap() = default;
+  ~Heap() final = default;
+
+  inline void* Allocate(size_t size, GCInfoIndex index);
+
+  void CollectGarbage();
+
+ private:
+  std::vector<HeapObjectHeader*> objects_;
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_HEAP_H_
diff --git a/deps/v8/src/heap/cppgc/platform.cc b/deps/v8/src/heap/cppgc/platform.cc
new file mode 100644
index 0000000000..3b20060392
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/platform.cc
@@ -0,0 +1,29 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/platform.h"
+
+#include "src/base/platform/platform.h"
+#include "src/heap/cppgc/gc-info-table.h"
+
+namespace cppgc {
+namespace internal {
+
+static PageAllocator* g_page_allocator;
+
+}  // namespace internal
+
+void InitializePlatform(PageAllocator* page_allocator) {
+  internal::g_page_allocator = page_allocator;
+  internal::GlobalGCInfoTable::Create(page_allocator);
+}
+
+void ShutdownPlatform() { internal::g_page_allocator = nullptr; }
+
+namespace internal {
+
+void Abort() { v8::base::OS::Abort(); }
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/sanitizers.h b/deps/v8/src/heap/cppgc/sanitizers.h
new file mode 100644
index 0000000000..e3102b01ed
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/sanitizers.h
@@ -0,0 +1,38 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_SANITIZERS_H_
+#define V8_HEAP_CPPGC_SANITIZERS_H_
+
+#include "src/base/macros.h"
+
+//
+// TODO(chromium:1056170): Find a place in base for sanitizer support.
+//
+
+#ifdef V8_USE_ADDRESS_SANITIZER
+
+#include <sanitizer/asan_interface.h>
+
+#define NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
+
+#else  // !V8_USE_ADDRESS_SANITIZER
+
+#define NO_SANITIZE_ADDRESS
+
+#endif  // V8_USE_ADDRESS_SANITIZER
+
+#ifdef V8_USE_MEMORY_SANITIZER
+
+#include <sanitizer/msan_interface.h>
+
+#define MSAN_UNPOISON(addr, size) __msan_unpoison(addr, size)
+
+#else  // !V8_USE_MEMORY_SANITIZER
+
+#define MSAN_UNPOISON(addr, size) ((void)(addr), (void)(size))
+
+#endif  // V8_USE_MEMORY_SANITIZER
+
+#endif  // V8_HEAP_CPPGC_SANITIZERS_H_
diff --git a/deps/v8/src/heap/cppgc/stack.cc b/deps/v8/src/heap/cppgc/stack.cc
new file mode 100644
index 0000000000..a821768917
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/stack.cc
@@ -0,0 +1,136 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/stack.h"
+
+#include <limits>
+
+#include "src/base/platform/platform.h"
+#include "src/heap/cppgc/globals.h"
+#include "src/heap/cppgc/sanitizers.h"
+
+namespace cppgc {
+namespace internal {
+
+using IterateStackCallback = void (Stack::*)(StackVisitor*, intptr_t*) const;
+extern "C" void PushAllRegistersAndIterateStack(const Stack*, StackVisitor*,
+                                                IterateStackCallback);
+
+Stack::Stack(const void* stack_start) : stack_start_(stack_start) {}
+
+bool Stack::IsOnStack(void* slot) const {
+  void* raw_slot = v8::base::Stack::GetStackSlot(slot);
+  return v8::base::Stack::GetCurrentStackPosition() <= raw_slot &&
+         raw_slot <= stack_start_;
+}
+
+namespace {
+
+#ifdef V8_USE_ADDRESS_SANITIZER
+
+// No ASAN support as accessing fake frames otherwise results in
+// "stack-use-after-scope" warnings.
+NO_SANITIZE_ADDRESS
+void IterateAsanFakeFrameIfNecessary(StackVisitor* visitor,
+                                     void* asan_fake_stack,
+                                     const void* stack_start,
+                                     const void* stack_end, void* address) {
+  // When using ASAN fake stack a pointer to the fake frame is kept on the
+  // native frame. In case |addr| points to a fake frame of the current stack
+  // iterate the fake frame. Frame layout see
+  // https://github.com/google/sanitizers/wiki/AddressSanitizerUseAfterReturn
+  if (asan_fake_stack) {
+    void* fake_frame_begin;
+    void* fake_frame_end;
+    void* real_stack_frame = __asan_addr_is_in_fake_stack(
+        asan_fake_stack, address, &fake_frame_begin, &fake_frame_end);
+    if (real_stack_frame) {
+      // |address| points to a fake frame. Check that the fake frame is part
+      // of this stack.
+      if (stack_start >= real_stack_frame && real_stack_frame >= stack_end) {
+        // Iterate the fake frame.
+        for (void** current = reinterpret_cast<void**>(fake_frame_begin);
+             current < fake_frame_end; ++current) {
+          void* addr = *current;
+          if (addr == nullptr) continue;
+          visitor->VisitPointer(addr);
+        }
+      }
+    }
+  }
+}
+
+#endif  // V8_USE_ADDRESS_SANITIZER
+
+#ifdef CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+void IterateSafeStackIfNecessary(StackVisitor* visitor) {
+#if defined(__has_feature)
+#if __has_feature(safe_stack)
+  // Source:
+  // https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/safestack/safestack.cpp
+  constexpr size_t kSafeStackAlignmentBytes = 16;
+  void* stack_end = __builtin___get_unsafe_stack_ptr();
+  void* stack_start = __builtin___get_unsafe_stack_top();
+  CHECK_GT(stack_start, stack_end);
+  CHECK_EQ(0u, reinterpret_cast<uintptr_t>(stack_end) &
+                   (kSafeStackAlignmentBytes - 1));
+  CHECK_EQ(0u, reinterpret_cast<uintptr_t>(stack_start) &
+                   (kSafeStackAlignmentBytes - 1));
+  void** current = reinterpret_cast<void**>(stack_end);
+  for (; current < stack_start; ++current) {
+    void* address = *current;
+    if (address == nullptr) continue;
+    visitor->VisitPointer(address);
+  }
+#endif  // __has_feature(safe_stack)
+#endif  // defined(__has_feature)
+}
+
+#endif  // CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+}  // namespace
+
+#ifdef CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+void Stack::IteratePointers(StackVisitor* visitor) const {
+  PushAllRegistersAndIterateStack(this, visitor, &Stack::IteratePointersImpl);
+  // No need to deal with callee-saved registers as they will be kept alive by
+  // the regular conservative stack iteration.
+  IterateSafeStackIfNecessary(visitor);
+}
+#endif  // CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+// No ASAN support as method accesses redzones while walking the stack.
+NO_SANITIZE_ADDRESS
+void Stack::IteratePointersImpl(StackVisitor* visitor,
+                                intptr_t* stack_end) const {
+#ifdef V8_USE_ADDRESS_SANITIZER
+  void* asan_fake_stack = __asan_get_current_fake_stack();
+#endif  // V8_USE_ADDRESS_SANITIZER
+  // All supported platforms should have their stack aligned to at least
+  // sizeof(void*).
+  constexpr size_t kMinStackAlignment = sizeof(void*);
+  // Redzone should not contain any pointers as the iteration is always called
+  // from the assembly trampoline. If inline assembly is ever inlined through
+  // LTO this may become necessary.
+  constexpr size_t kRedZoneBytes = 128;
+  void** current = reinterpret_cast<void**>(
+      reinterpret_cast<uintptr_t>(stack_end - kRedZoneBytes));
+  CHECK_EQ(0u, reinterpret_cast<uintptr_t>(current) & (kMinStackAlignment - 1));
+  for (; current < stack_start_; ++current) {
+    // MSAN: Instead of unpoisoning the whole stack, the slot's value is copied
+    // into a local which is unpoisoned.
+    void* address = *current;
+    MSAN_UNPOISON(address, sizeof(address));
+    if (address == nullptr) continue;
+    visitor->VisitPointer(address);
+#ifdef V8_USE_ADDRESS_SANITIZER
+    IterateAsanFakeFrameIfNecessary(visitor, asan_fake_stack, stack_start_,
+                                    stack_end, address);
+#endif  // V8_USE_ADDRESS_SANITIZER
+  }
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/src/heap/cppgc/stack.h b/deps/v8/src/heap/cppgc/stack.h
new file mode 100644
index 0000000000..599bf3a54a
--- /dev/null
+++ b/deps/v8/src/heap/cppgc/stack.h
@@ -0,0 +1,49 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_CPPGC_STACK_H_
+#define V8_HEAP_CPPGC_STACK_H_
+
+#include "src/base/macros.h"
+
+// TODO(chromium:1056170): Implement all platforms.
+#if defined(V8_TARGET_ARCH_X64)
+#define CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN 1
+#endif
+
+namespace cppgc {
+namespace internal {
+
+class StackVisitor {
+ public:
+  virtual void VisitPointer(const void* address) = 0;
+};
+
+// Abstraction over the stack. Supports handling of:
+// - native stack;
+// - ASAN/MSAN;
+// - SafeStack: https://releases.llvm.org/10.0.0/tools/clang/docs/SafeStack.html
+class V8_EXPORT_PRIVATE Stack final {
+ public:
+  explicit Stack(const void* stack_start);
+
+  // Returns true if |slot| is part of the stack and false otherwise.
+  bool IsOnStack(void* slot) const;
+
+  // Word-aligned iteration of the stack. Slot values are passed on to
+  // |visitor|.
+#ifdef CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+  void IteratePointers(StackVisitor* visitor) const;
+#endif  // CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+ private:
+  void IteratePointersImpl(StackVisitor* visitor, intptr_t* stack_end) const;
+
+  const void* stack_start_;
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // V8_HEAP_CPPGC_STACK_H_
diff --git a/deps/v8/src/heap/embedder-tracing.cc b/deps/v8/src/heap/embedder-tracing.cc
index e3317b1379..2b46da1feb 100644
--- a/deps/v8/src/heap/embedder-tracing.cc
+++ b/deps/v8/src/heap/embedder-tracing.cc
@@ -24,7 +24,6 @@ void LocalEmbedderHeapTracer::TracePrologue(
     EmbedderHeapTracer::TraceFlags flags) {
   if (!InUse()) return;
 
-  num_v8_marking_worklist_was_empty_ = 0;
   embedder_worklist_empty_ = false;
   remote_tracer_->TracePrologue(flags);
 }
diff --git a/deps/v8/src/heap/embedder-tracing.h b/deps/v8/src/heap/embedder-tracing.h
index 05932ea141..cc3801e479 100644
--- a/deps/v8/src/heap/embedder-tracing.h
+++ b/deps/v8/src/heap/embedder-tracing.h
@@ -69,15 +69,9 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
     remote_tracer_->ResetHandleInNonTracingGC(handle);
   }
 
-  void NotifyV8MarkingWorklistWasEmpty() {
-    num_v8_marking_worklist_was_empty_++;
-  }
-
   bool ShouldFinalizeIncrementalMarking() {
-    static const size_t kMaxIncrementalFixpointRounds = 3;
     return !FLAG_incremental_marking_wrappers || !InUse() ||
-           (IsRemoteTracingDone() && embedder_worklist_empty_) ||
-           num_v8_marking_worklist_was_empty_ > kMaxIncrementalFixpointRounds;
+           (IsRemoteTracingDone() && embedder_worklist_empty_);
   }
 
   void SetEmbedderStackStateForNextFinalization(
@@ -114,7 +108,6 @@ class V8_EXPORT_PRIVATE LocalEmbedderHeapTracer final {
   Isolate* const isolate_;
   EmbedderHeapTracer* remote_tracer_ = nullptr;
 
-  size_t num_v8_marking_worklist_was_empty_ = 0;
   EmbedderHeapTracer::EmbedderStackState embedder_stack_state_ =
       EmbedderHeapTracer::kUnknown;
   // Indicates whether the embedder worklist was observed empty on the main
diff --git a/deps/v8/src/heap/factory-base-inl.h b/deps/v8/src/heap/factory-base-inl.h
new file mode 100644
index 0000000000..6f218b8248
--- /dev/null
+++ b/deps/v8/src/heap/factory-base-inl.h
@@ -0,0 +1,99 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_FACTORY_BASE_INL_H_
+#define V8_HEAP_FACTORY_BASE_INL_H_
+
+#include "src/heap/factory-base.h"
+
+#include "src/numbers/conversions.h"
+#include "src/objects/heap-number.h"
+#include "src/objects/smi.h"
+#include "src/roots/roots.h"
+
+namespace v8 {
+namespace internal {
+
+template <typename Impl>
+Handle<Oddball> FactoryBase<Impl>::ToBoolean(bool value) {
+  return value ? impl()->true_value() : impl()->false_value();
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<Object> FactoryBase<Impl>::NewNumber(double value) {
+  // Materialize as a SMI if possible.
+  int32_t int_value;
+  if (DoubleToSmiInteger(value, &int_value)) {
+    return handle(Smi::FromInt(int_value), isolate());
+  }
+  return NewHeapNumber<allocation>(value);
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<Object> FactoryBase<Impl>::NewNumberFromInt(int32_t value) {
+  if (Smi::IsValid(value)) return handle(Smi::FromInt(value), isolate());
+  // Bypass NewNumber to avoid various redundant checks.
+  return NewHeapNumber<allocation>(FastI2D(value));
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<Object> FactoryBase<Impl>::NewNumberFromUint(uint32_t value) {
+  int32_t int32v = static_cast<int32_t>(value);
+  if (int32v >= 0 && Smi::IsValid(int32v)) {
+    return handle(Smi::FromInt(int32v), isolate());
+  }
+  return NewHeapNumber<allocation>(FastUI2D(value));
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<Object> FactoryBase<Impl>::NewNumberFromSize(size_t value) {
+  // We can't use Smi::IsValid() here because that operates on a signed
+  // intptr_t, and casting from size_t could create a bogus sign bit.
+  if (value <= static_cast<size_t>(Smi::kMaxValue)) {
+    return handle(Smi::FromIntptr(static_cast<intptr_t>(value)), isolate());
+  }
+  return NewHeapNumber<allocation>(static_cast<double>(value));
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<Object> FactoryBase<Impl>::NewNumberFromInt64(int64_t value) {
+  if (value <= std::numeric_limits<int32_t>::max() &&
+      value >= std::numeric_limits<int32_t>::min() &&
+      Smi::IsValid(static_cast<int32_t>(value))) {
+    return handle(Smi::FromInt(static_cast<int32_t>(value)), isolate());
+  }
+  return NewHeapNumber<allocation>(static_cast<double>(value));
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<HeapNumber> FactoryBase<Impl>::NewHeapNumber(double value) {
+  Handle<HeapNumber> heap_number = NewHeapNumber<allocation>();
+  heap_number->set_value(value);
+  return heap_number;
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<HeapNumber> FactoryBase<Impl>::NewHeapNumberFromBits(uint64_t bits) {
+  Handle<HeapNumber> heap_number = NewHeapNumber<allocation>();
+  heap_number->set_value_as_bits(bits);
+  return heap_number;
+}
+
+template <typename Impl>
+template <AllocationType allocation>
+Handle<HeapNumber> FactoryBase<Impl>::NewHeapNumberWithHoleNaN() {
+  return NewHeapNumberFromBits<allocation>(kHoleNanInt64);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_FACTORY_BASE_INL_H_
diff --git a/deps/v8/src/heap/factory-base.cc b/deps/v8/src/heap/factory-base.cc
index bdd1ccf2e2..e2ef3318ce 100644
--- a/deps/v8/src/heap/factory-base.cc
+++ b/deps/v8/src/heap/factory-base.cc
@@ -4,21 +4,448 @@
 
 #include "src/heap/factory-base.h"
 
+#include "src/ast/ast-source-ranges.h"
 #include "src/ast/ast.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/handles/handles-inl.h"
 #include "src/heap/factory.h"
-#include "src/heap/off-thread-factory.h"
-#include "src/objects/string-inl.h"
-#include "src/utils/memcopy.h"
+#include "src/heap/heap-inl.h"
+#include "src/heap/off-thread-factory-inl.h"
+#include "src/heap/read-only-heap.h"
+#include "src/logging/log.h"
+#include "src/logging/off-thread-logger.h"
+#include "src/objects/literal-objects-inl.h"
+#include "src/objects/module-inl.h"
+#include "src/objects/oddball.h"
+#include "src/objects/shared-function-info-inl.h"
+#include "src/objects/source-text-module.h"
+#include "src/objects/template-objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 template <typename Impl>
-FactoryHandle<Impl, SeqOneByteString>
-FactoryBase<Impl>::NewOneByteInternalizedString(
+template <AllocationType allocation>
+Handle<HeapNumber> FactoryBase<Impl>::NewHeapNumber() {
+  STATIC_ASSERT(HeapNumber::kSize <= kMaxRegularHeapObjectSize);
+  Map map = read_only_roots().heap_number_map();
+  HeapObject result = AllocateRawWithImmortalMap(HeapNumber::kSize, allocation,
+                                                 map, kDoubleUnaligned);
+  return handle(HeapNumber::cast(result), isolate());
+}
+
+template V8_EXPORT_PRIVATE Handle<HeapNumber>
+FactoryBase<Factory>::NewHeapNumber<AllocationType::kYoung>();
+template V8_EXPORT_PRIVATE Handle<HeapNumber>
+FactoryBase<Factory>::NewHeapNumber<AllocationType::kOld>();
+template V8_EXPORT_PRIVATE Handle<HeapNumber>
+FactoryBase<Factory>::NewHeapNumber<AllocationType::kReadOnly>();
+
+template V8_EXPORT_PRIVATE Handle<HeapNumber>
+FactoryBase<OffThreadFactory>::NewHeapNumber<AllocationType::kOld>();
+
+template <typename Impl>
+Handle<Struct> FactoryBase<Impl>::NewStruct(InstanceType type,
+                                            AllocationType allocation) {
+  Map map = Map::GetInstanceTypeMap(read_only_roots(), type);
+  int size = map.instance_size();
+  HeapObject result = AllocateRawWithImmortalMap(size, allocation, map);
+  Handle<Struct> str = handle(Struct::cast(result), isolate());
+  str->InitializeBody(size);
+  return str;
+}
+
+template <typename Impl>
+Handle<AccessorPair> FactoryBase<Impl>::NewAccessorPair() {
+  Handle<AccessorPair> accessors = Handle<AccessorPair>::cast(
+      NewStruct(ACCESSOR_PAIR_TYPE, AllocationType::kOld));
+  accessors->set_getter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
+  accessors->set_setter(read_only_roots().null_value(), SKIP_WRITE_BARRIER);
+  return accessors;
+}
+
+template <typename Impl>
+Handle<FixedArray> FactoryBase<Impl>::NewFixedArray(int length,
+                                                    AllocationType allocation) {
+  DCHECK_LE(0, length);
+  if (length == 0) return impl()->empty_fixed_array();
+  return NewFixedArrayWithFiller(
+      read_only_roots().fixed_array_map_handle(), length,
+      read_only_roots().undefined_value_handle(), allocation);
+}
+
+template <typename Impl>
+Handle<FixedArray> FactoryBase<Impl>::NewFixedArrayWithMap(
+    Handle<Map> map, int length, AllocationType allocation) {
+  // Zero-length case must be handled outside, where the knowledge about
+  // the map is.
+  DCHECK_LT(0, length);
+  return NewFixedArrayWithFiller(
+      map, length, read_only_roots().undefined_value_handle(), allocation);
+}
+
+template <typename Impl>
+Handle<FixedArray> FactoryBase<Impl>::NewFixedArrayWithHoles(
+    int length, AllocationType allocation) {
+  DCHECK_LE(0, length);
+  if (length == 0) return impl()->empty_fixed_array();
+  return NewFixedArrayWithFiller(
+      read_only_roots().fixed_array_map_handle(), length,
+      read_only_roots().the_hole_value_handle(), allocation);
+}
+
+template <typename Impl>
+Handle<FixedArray> FactoryBase<Impl>::NewFixedArrayWithFiller(
+    Handle<Map> map, int length, Handle<Oddball> filler,
+    AllocationType allocation) {
+  HeapObject result = AllocateRawFixedArray(length, allocation);
+  DCHECK(ReadOnlyHeap::Contains(*map));
+  DCHECK(ReadOnlyHeap::Contains(*filler));
+  result.set_map_after_allocation(*map, SKIP_WRITE_BARRIER);
+  Handle<FixedArray> array = handle(FixedArray::cast(result), isolate());
+  array->set_length(length);
+  MemsetTagged(array->data_start(), *filler, length);
+  return array;
+}
+
+template <typename Impl>
+Handle<FixedArrayBase> FactoryBase<Impl>::NewFixedDoubleArray(
+    int length, AllocationType allocation) {
+  if (length == 0) return impl()->empty_fixed_array();
+  if (length < 0 || length > FixedDoubleArray::kMaxLength) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+  }
+  int size = FixedDoubleArray::SizeFor(length);
+  Map map = read_only_roots().fixed_double_array_map();
+  HeapObject result =
+      AllocateRawWithImmortalMap(size, allocation, map, kDoubleAligned);
+  Handle<FixedDoubleArray> array =
+      handle(FixedDoubleArray::cast(result), isolate());
+  array->set_length(length);
+  return array;
+}
+
+template <typename Impl>
+Handle<WeakFixedArray> FactoryBase<Impl>::NewWeakFixedArrayWithMap(
+    Map map, int length, AllocationType allocation) {
+  // Zero-length case must be handled outside.
+  DCHECK_LT(0, length);
+  DCHECK(ReadOnlyHeap::Contains(map));
+
+  HeapObject result =
+      AllocateRawArray(WeakFixedArray::SizeFor(length), allocation);
+  result.set_map_after_allocation(map, SKIP_WRITE_BARRIER);
+
+  Handle<WeakFixedArray> array =
+      handle(WeakFixedArray::cast(result), isolate());
+  array->set_length(length);
+  MemsetTagged(ObjectSlot(array->data_start()),
+               read_only_roots().undefined_value(), length);
+
+  return array;
+}
+
+template <typename Impl>
+Handle<WeakFixedArray> FactoryBase<Impl>::NewWeakFixedArray(
+    int length, AllocationType allocation) {
+  DCHECK_LE(0, length);
+  if (length == 0) return impl()->empty_weak_fixed_array();
+  return NewWeakFixedArrayWithMap(read_only_roots().weak_fixed_array_map(),
+                                  length, allocation);
+}
+
+template <typename Impl>
+Handle<ByteArray> FactoryBase<Impl>::NewByteArray(int length,
+                                                  AllocationType allocation) {
+  if (length < 0 || length > ByteArray::kMaxLength) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+  }
+  int size = ByteArray::SizeFor(length);
+  HeapObject result = AllocateRawWithImmortalMap(
+      size, allocation, read_only_roots().byte_array_map());
+  Handle<ByteArray> array(ByteArray::cast(result), isolate());
+  array->set_length(length);
+  array->clear_padding();
+  return array;
+}
+
+template <typename Impl>
+Handle<BytecodeArray> FactoryBase<Impl>::NewBytecodeArray(
+    int length, const byte* raw_bytecodes, int frame_size, int parameter_count,
+    Handle<FixedArray> constant_pool) {
+  if (length < 0 || length > BytecodeArray::kMaxLength) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+  }
+  // Bytecode array is AllocationType::kOld, so constant pool array should be
+  // too.
+  DCHECK(!Heap::InYoungGeneration(*constant_pool));
+
+  int size = BytecodeArray::SizeFor(length);
+  HeapObject result = AllocateRawWithImmortalMap(
+      size, AllocationType::kOld, read_only_roots().bytecode_array_map());
+  Handle<BytecodeArray> instance(BytecodeArray::cast(result), isolate());
+  instance->set_length(length);
+  instance->set_frame_size(frame_size);
+  instance->set_parameter_count(parameter_count);
+  instance->set_incoming_new_target_or_generator_register(
+      interpreter::Register::invalid_value());
+  instance->set_osr_loop_nesting_level(0);
+  instance->set_bytecode_age(BytecodeArray::kNoAgeBytecodeAge);
+  instance->set_constant_pool(*constant_pool);
+  instance->set_handler_table(read_only_roots().empty_byte_array());
+  instance->set_source_position_table(read_only_roots().undefined_value());
+  CopyBytes(reinterpret_cast<byte*>(instance->GetFirstBytecodeAddress()),
+            raw_bytecodes, length);
+  instance->clear_padding();
+
+  return instance;
+}
+
+template <typename Impl>
+Handle<Script> FactoryBase<Impl>::NewScript(Handle<String> source) {
+  return NewScriptWithId(source, isolate()->GetNextScriptId());
+}
+
+template <typename Impl>
+Handle<Script> FactoryBase<Impl>::NewScriptWithId(Handle<String> source,
+                                                  int script_id) {
+  // Create and initialize script object.
+  ReadOnlyRoots roots = read_only_roots();
+  Handle<Script> script =
+      Handle<Script>::cast(NewStruct(SCRIPT_TYPE, AllocationType::kOld));
+  script->set_source(*source);
+  script->set_name(roots.undefined_value());
+  script->set_id(script_id);
+  script->set_line_offset(0);
+  script->set_column_offset(0);
+  script->set_context_data(roots.undefined_value());
+  script->set_type(Script::TYPE_NORMAL);
+  script->set_line_ends(roots.undefined_value());
+  script->set_eval_from_shared_or_wrapped_arguments(roots.undefined_value());
+  script->set_eval_from_position(0);
+  script->set_shared_function_infos(roots.empty_weak_fixed_array(),
+                                    SKIP_WRITE_BARRIER);
+  script->set_flags(0);
+  script->set_host_defined_options(roots.empty_fixed_array());
+
+  impl()->AddToScriptList(script);
+
+  LOG(isolate(), ScriptEvent(Logger::ScriptEventType::kCreate, script_id));
+  return script;
+}
+
+template <typename Impl>
+Handle<SharedFunctionInfo> FactoryBase<Impl>::NewSharedFunctionInfoForLiteral(
+    FunctionLiteral* literal, Handle<Script> script, bool is_toplevel) {
+  FunctionKind kind = literal->kind();
+  Handle<SharedFunctionInfo> shared =
+      NewSharedFunctionInfo(literal->GetName(isolate()), MaybeHandle<Code>(),
+                            Builtins::kCompileLazy, kind);
+  SharedFunctionInfo::InitFromFunctionLiteral(isolate(), shared, literal,
+                                              is_toplevel);
+  shared->SetScript(read_only_roots(), *script, literal->function_literal_id(),
+                    false);
+  return shared;
+}
+
+template <typename Impl>
+Handle<PreparseData> FactoryBase<Impl>::NewPreparseData(int data_length,
+                                                        int children_length) {
+  int size = PreparseData::SizeFor(data_length, children_length);
+  Handle<PreparseData> result = handle(
+      PreparseData::cast(AllocateRawWithImmortalMap(
+          size, AllocationType::kOld, read_only_roots().preparse_data_map())),
+      isolate());
+  result->set_data_length(data_length);
+  result->set_children_length(children_length);
+  MemsetTagged(result->inner_data_start(), read_only_roots().null_value(),
+               children_length);
+  result->clear_padding();
+  return result;
+}
+
+template <typename Impl>
+Handle<UncompiledDataWithoutPreparseData>
+FactoryBase<Impl>::NewUncompiledDataWithoutPreparseData(
+    Handle<String> inferred_name, int32_t start_position,
+    int32_t end_position) {
+  Handle<UncompiledDataWithoutPreparseData> result = handle(
+      UncompiledDataWithoutPreparseData::cast(NewWithImmortalMap(
+          impl()->read_only_roots().uncompiled_data_without_preparse_data_map(),
+          AllocationType::kOld)),
+      isolate());
+
+  result->Init(impl(), *inferred_name, start_position, end_position);
+  return result;
+}
+
+template <typename Impl>
+Handle<UncompiledDataWithPreparseData>
+FactoryBase<Impl>::NewUncompiledDataWithPreparseData(
+    Handle<String> inferred_name, int32_t start_position, int32_t end_position,
+    Handle<PreparseData> preparse_data) {
+  Handle<UncompiledDataWithPreparseData> result = handle(
+      UncompiledDataWithPreparseData::cast(NewWithImmortalMap(
+          impl()->read_only_roots().uncompiled_data_with_preparse_data_map(),
+          AllocationType::kOld)),
+      isolate());
+
+  result->Init(impl(), *inferred_name, start_position, end_position,
+               *preparse_data);
+
+  return result;
+}
+
+template <typename Impl>
+Handle<SharedFunctionInfo> FactoryBase<Impl>::NewSharedFunctionInfo(
+    MaybeHandle<String> maybe_name, MaybeHandle<HeapObject> maybe_function_data,
+    int maybe_builtin_index, FunctionKind kind) {
+  Handle<SharedFunctionInfo> shared = NewSharedFunctionInfo();
+
+  // Function names are assumed to be flat elsewhere.
+  Handle<String> shared_name;
+  bool has_shared_name = maybe_name.ToHandle(&shared_name);
+  if (has_shared_name) {
+    DCHECK(shared_name->IsFlat());
+    shared->set_name_or_scope_info(*shared_name);
+  } else {
+    DCHECK_EQ(shared->name_or_scope_info(),
+              SharedFunctionInfo::kNoSharedNameSentinel);
+  }
+
+  Handle<HeapObject> function_data;
+  if (maybe_function_data.ToHandle(&function_data)) {
+    // If we pass function_data then we shouldn't pass a builtin index, and
+    // the function_data should not be code with a builtin.
+    DCHECK(!Builtins::IsBuiltinId(maybe_builtin_index));
+    DCHECK_IMPLIES(function_data->IsCode(),
+                   !Code::cast(*function_data).is_builtin());
+    shared->set_function_data(*function_data);
+  } else if (Builtins::IsBuiltinId(maybe_builtin_index)) {
+    shared->set_builtin_id(maybe_builtin_index);
+  } else {
+    shared->set_builtin_id(Builtins::kIllegal);
+  }
+
+  shared->CalculateConstructAsBuiltin();
+  shared->set_kind(kind);
+
+#ifdef VERIFY_HEAP
+  shared->SharedFunctionInfoVerify(isolate());
+#endif  // VERIFY_HEAP
+  return shared;
+}
+
+template <typename Impl>
+Handle<ObjectBoilerplateDescription>
+FactoryBase<Impl>::NewObjectBoilerplateDescription(int boilerplate,
+                                                   int all_properties,
+                                                   int index_keys,
+                                                   bool has_seen_proto) {
+  DCHECK_GE(boilerplate, 0);
+  DCHECK_GE(all_properties, index_keys);
+  DCHECK_GE(index_keys, 0);
+
+  int backing_store_size =
+      all_properties - index_keys - (has_seen_proto ? 1 : 0);
+  DCHECK_GE(backing_store_size, 0);
+  bool has_different_size_backing_store = boilerplate != backing_store_size;
+
+  // Space for name and value for every boilerplate property + LiteralType flag.
+  int size =
+      2 * boilerplate + ObjectBoilerplateDescription::kDescriptionStartIndex;
+
+  if (has_different_size_backing_store) {
+    // An extra entry for the backing store size.
+    size++;
+  }
+
+  Handle<ObjectBoilerplateDescription> description =
+      Handle<ObjectBoilerplateDescription>::cast(NewFixedArrayWithMap(
+          read_only_roots().object_boilerplate_description_map_handle(), size,
+          AllocationType::kOld));
+
+  if (has_different_size_backing_store) {
+    DCHECK_IMPLIES((boilerplate == (all_properties - index_keys)),
+                   has_seen_proto);
+    description->set_backing_store_size(backing_store_size);
+  }
+
+  description->set_flags(0);
+
+  return description;
+}
+
+template <typename Impl>
+Handle<ArrayBoilerplateDescription>
+FactoryBase<Impl>::NewArrayBoilerplateDescription(
+    ElementsKind elements_kind, Handle<FixedArrayBase> constant_values) {
+  Handle<ArrayBoilerplateDescription> result =
+      Handle<ArrayBoilerplateDescription>::cast(
+          NewStruct(ARRAY_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld));
+  result->set_elements_kind(elements_kind);
+  result->set_constant_elements(*constant_values);
+  return result;
+}
+
+template <typename Impl>
+Handle<TemplateObjectDescription>
+FactoryBase<Impl>::NewTemplateObjectDescription(
+    Handle<FixedArray> raw_strings, Handle<FixedArray> cooked_strings) {
+  DCHECK_EQ(raw_strings->length(), cooked_strings->length());
+  DCHECK_LT(0, raw_strings->length());
+  Handle<TemplateObjectDescription> result =
+      Handle<TemplateObjectDescription>::cast(
+          NewStruct(TEMPLATE_OBJECT_DESCRIPTION_TYPE, AllocationType::kOld));
+  result->set_raw_strings(*raw_strings);
+  result->set_cooked_strings(*cooked_strings);
+  return result;
+}
+
+template <typename Impl>
+Handle<FeedbackMetadata> FactoryBase<Impl>::NewFeedbackMetadata(
+    int slot_count, int feedback_cell_count, AllocationType allocation) {
+  DCHECK_LE(0, slot_count);
+  int size = FeedbackMetadata::SizeFor(slot_count);
+  HeapObject result = AllocateRawWithImmortalMap(
+      size, allocation, read_only_roots().feedback_metadata_map());
+  Handle<FeedbackMetadata> data(FeedbackMetadata::cast(result), isolate());
+  data->set_slot_count(slot_count);
+  data->set_closure_feedback_cell_count(feedback_cell_count);
+
+  // Initialize the data section to 0.
+  int data_size = size - FeedbackMetadata::kHeaderSize;
+  Address data_start = data->address() + FeedbackMetadata::kHeaderSize;
+  memset(reinterpret_cast<byte*>(data_start), 0, data_size);
+  // Fields have been zeroed out but not initialized, so this object will not
+  // pass object verification at this point.
+  return data;
+}
+
+template <typename Impl>
+Handle<CoverageInfo> FactoryBase<Impl>::NewCoverageInfo(
+    const ZoneVector<SourceRange>& slots) {
+  const int slot_count = static_cast<int>(slots.size());
+
+  int size = CoverageInfo::SizeFor(slot_count);
+  Map map = read_only_roots().coverage_info_map();
+  HeapObject result =
+      AllocateRawWithImmortalMap(size, AllocationType::kYoung, map);
+  Handle<CoverageInfo> info(CoverageInfo::cast(result), isolate());
+
+  info->set_slot_count(slot_count);
+  for (int i = 0; i < slot_count; i++) {
+    SourceRange range = slots[i];
+    info->InitializeSlot(i, range.start, range.end);
+  }
+
+  return info;
+}
+
+template <typename Impl>
+Handle<SeqOneByteString> FactoryBase<Impl>::NewOneByteInternalizedString(
     const Vector<const uint8_t>& str, uint32_t hash_field) {
-  FactoryHandle<Impl, SeqOneByteString> result =
+  Handle<SeqOneByteString> result =
       AllocateRawOneByteInternalizedString(str.length(), hash_field);
   DisallowHeapAllocation no_gc;
   MemCopy(result->GetChars(no_gc), str.begin(), str.length());
@@ -26,10 +453,9 @@ FactoryBase<Impl>::NewOneByteInternalizedString(
 }
 
 template <typename Impl>
-FactoryHandle<Impl, SeqTwoByteString>
-FactoryBase<Impl>::NewTwoByteInternalizedString(const Vector<const uc16>& str,
-                                                uint32_t hash_field) {
-  FactoryHandle<Impl, SeqTwoByteString> result =
+Handle<SeqTwoByteString> FactoryBase<Impl>::NewTwoByteInternalizedString(
+    const Vector<const uc16>& str, uint32_t hash_field) {
+  Handle<SeqTwoByteString> result =
       AllocateRawTwoByteInternalizedString(str.length(), hash_field);
   DisallowHeapAllocation no_gc;
   MemCopy(result->GetChars(no_gc), str.begin(), str.length() * kUC16Size);
@@ -37,11 +463,10 @@ FactoryBase<Impl>::NewTwoByteInternalizedString(const Vector<const uc16>& str,
 }
 
 template <typename Impl>
-FactoryMaybeHandle<Impl, SeqOneByteString>
-FactoryBase<Impl>::NewRawOneByteString(int length, AllocationType allocation) {
+MaybeHandle<SeqOneByteString> FactoryBase<Impl>::NewRawOneByteString(
+    int length, AllocationType allocation) {
   if (length > String::kMaxLength || length < 0) {
-    return impl()->template Throw<SeqOneByteString>(
-        impl()->NewInvalidStringLengthError());
+    THROW_NEW_ERROR(isolate(), NewInvalidStringLengthError(), SeqOneByteString);
   }
   DCHECK_GT(length, 0);  // Use Factory::empty_string() instead.
   int size = SeqOneByteString::SizeFor(length);
@@ -49,8 +474,8 @@ FactoryBase<Impl>::NewRawOneByteString(int length, AllocationType allocation) {
 
   HeapObject result = AllocateRawWithImmortalMap(
       size, allocation, read_only_roots().one_byte_string_map());
-  FactoryHandle<Impl, SeqOneByteString> string =
-      handle(SeqOneByteString::cast(result), impl());
+  Handle<SeqOneByteString> string =
+      handle(SeqOneByteString::cast(result), isolate());
   string->set_length(length);
   string->set_hash_field(String::kEmptyHashField);
   DCHECK_EQ(size, string->Size());
@@ -58,11 +483,10 @@ FactoryBase<Impl>::NewRawOneByteString(int length, AllocationType allocation) {
 }
 
 template <typename Impl>
-FactoryMaybeHandle<Impl, SeqTwoByteString>
-FactoryBase<Impl>::NewRawTwoByteString(int length, AllocationType allocation) {
+MaybeHandle<SeqTwoByteString> FactoryBase<Impl>::NewRawTwoByteString(
+    int length, AllocationType allocation) {
   if (length > String::kMaxLength || length < 0) {
-    return impl()->template Throw<SeqTwoByteString>(
-        impl()->NewInvalidStringLengthError());
+    THROW_NEW_ERROR(isolate(), NewInvalidStringLengthError(), SeqTwoByteString);
   }
   DCHECK_GT(length, 0);  // Use Factory::empty_string() instead.
   int size = SeqTwoByteString::SizeFor(length);
@@ -70,8 +494,8 @@ FactoryBase<Impl>::NewRawTwoByteString(int length, AllocationType allocation) {
 
   HeapObject result = AllocateRawWithImmortalMap(
       size, allocation, read_only_roots().string_map());
-  FactoryHandle<Impl, SeqTwoByteString> string =
-      handle(SeqTwoByteString::cast(result), impl());
+  Handle<SeqTwoByteString> string =
+      handle(SeqTwoByteString::cast(result), isolate());
   string->set_length(length);
   string->set_hash_field(String::kEmptyHashField);
   DCHECK_EQ(size, string->Size());
@@ -79,14 +503,13 @@ FactoryBase<Impl>::NewRawTwoByteString(int length, AllocationType allocation) {
 }
 
 template <typename Impl>
-FactoryMaybeHandle<Impl, String> FactoryBase<Impl>::NewConsString(
-    FactoryHandle<Impl, String> left, FactoryHandle<Impl, String> right,
-    AllocationType allocation) {
+MaybeHandle<String> FactoryBase<Impl>::NewConsString(
+    Handle<String> left, Handle<String> right, AllocationType allocation) {
   if (left->IsThinString()) {
-    left = handle(ThinString::cast(*left).actual(), impl());
+    left = handle(ThinString::cast(*left).actual(), isolate());
   }
   if (right->IsThinString()) {
-    right = handle(ThinString::cast(*right).actual(), impl());
+    right = handle(ThinString::cast(*right).actual(), isolate());
   }
   int left_length = left->length();
   if (left_length == 0) return right;
@@ -104,8 +527,7 @@ FactoryMaybeHandle<Impl, String> FactoryBase<Impl>::NewConsString(
   // Make sure that an out of memory exception is thrown if the length
   // of the new cons string is too large.
   if (length > String::kMaxLength || length < 0) {
-    return impl()->template Throw<String>(
-        impl()->NewInvalidStringLengthError());
+    THROW_NEW_ERROR(isolate(), NewInvalidStringLengthError(), String);
   }
 
   bool left_is_one_byte = left->IsOneByteRepresentation();
@@ -121,7 +543,7 @@ FactoryMaybeHandle<Impl, String> FactoryBase<Impl>::NewConsString(
 
     STATIC_ASSERT(ConsString::kMinLength <= String::kMaxLength);
     if (is_one_byte) {
-      FactoryHandle<Impl, SeqOneByteString> result =
+      Handle<SeqOneByteString> result =
           NewRawOneByteString(length, allocation).ToHandleChecked();
       DisallowHeapAllocation no_gc;
       uint8_t* dest = result->GetChars(no_gc);
@@ -134,7 +556,7 @@ FactoryMaybeHandle<Impl, String> FactoryBase<Impl>::NewConsString(
       return result;
     }
 
-    FactoryHandle<Impl, SeqTwoByteString> result =
+    Handle<SeqTwoByteString> result =
         NewRawTwoByteString(length, allocation).ToHandleChecked();
 
     DisallowHeapAllocation pointer_stays_valid;
@@ -148,22 +570,23 @@ FactoryMaybeHandle<Impl, String> FactoryBase<Impl>::NewConsString(
 }
 
 template <typename Impl>
-FactoryHandle<Impl, String> FactoryBase<Impl>::NewConsString(
-    FactoryHandle<Impl, String> left, FactoryHandle<Impl, String> right,
-    int length, bool one_byte, AllocationType allocation) {
+Handle<String> FactoryBase<Impl>::NewConsString(Handle<String> left,
+                                                Handle<String> right,
+                                                int length, bool one_byte,
+                                                AllocationType allocation) {
   DCHECK(!left->IsThinString());
   DCHECK(!right->IsThinString());
   DCHECK_GE(length, ConsString::kMinLength);
   DCHECK_LE(length, String::kMaxLength);
 
-  FactoryHandle<Impl, ConsString> result = handle(
+  Handle<ConsString> result = handle(
       ConsString::cast(
           one_byte
               ? NewWithImmortalMap(read_only_roots().cons_one_byte_string_map(),
                                    allocation)
               : NewWithImmortalMap(read_only_roots().cons_string_map(),
                                    allocation)),
-      impl());
+      isolate());
 
   DisallowHeapAllocation no_gc;
   WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
@@ -176,7 +599,81 @@ FactoryHandle<Impl, String> FactoryBase<Impl>::NewConsString(
 }
 
 template <typename Impl>
-FactoryHandle<Impl, SeqOneByteString>
+Handle<FreshlyAllocatedBigInt> FactoryBase<Impl>::NewBigInt(
+    int length, AllocationType allocation) {
+  if (length < 0 || length > BigInt::kMaxLength) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid BigInt length");
+  }
+  HeapObject result = AllocateRawWithImmortalMap(
+      BigInt::SizeFor(length), allocation, read_only_roots().bigint_map());
+  FreshlyAllocatedBigInt bigint = FreshlyAllocatedBigInt::cast(result);
+  bigint.clear_padding();
+  return handle(bigint, isolate());
+}
+
+template <typename Impl>
+Handle<ScopeInfo> FactoryBase<Impl>::NewScopeInfo(int length,
+                                                  AllocationType type) {
+  DCHECK(type == AllocationType::kOld || type == AllocationType::kReadOnly);
+  return Handle<ScopeInfo>::cast(NewFixedArrayWithMap(
+      read_only_roots().scope_info_map_handle(), length, type));
+}
+
+template <typename Impl>
+Handle<SourceTextModuleInfo> FactoryBase<Impl>::NewSourceTextModuleInfo() {
+  return Handle<SourceTextModuleInfo>::cast(NewFixedArrayWithMap(
+      read_only_roots().module_info_map_handle(), SourceTextModuleInfo::kLength,
+      AllocationType::kOld));
+}
+
+template <typename Impl>
+Handle<SharedFunctionInfo> FactoryBase<Impl>::NewSharedFunctionInfo() {
+  Map map = read_only_roots().shared_function_info_map();
+
+  Handle<SharedFunctionInfo> shared = handle(
+      SharedFunctionInfo::cast(NewWithImmortalMap(map, AllocationType::kOld)),
+      isolate());
+  int unique_id = -1;
+#if V8_SFI_HAS_UNIQUE_ID
+  unique_id = isolate()->GetNextUniqueSharedFunctionInfoId();
+#endif  // V8_SFI_HAS_UNIQUE_ID
+
+  shared->Init(read_only_roots(), unique_id);
+
+#ifdef VERIFY_HEAP
+  shared->SharedFunctionInfoVerify(isolate());
+#endif  // VERIFY_HEAP
+  return shared;
+}
+
+template <typename Impl>
+Handle<DescriptorArray> FactoryBase<Impl>::NewDescriptorArray(
+    int number_of_descriptors, int slack, AllocationType allocation) {
+  int number_of_all_descriptors = number_of_descriptors + slack;
+  // Zero-length case must be handled outside.
+  DCHECK_LT(0, number_of_all_descriptors);
+  int size = DescriptorArray::SizeFor(number_of_all_descriptors);
+  HeapObject obj = AllocateRawWithImmortalMap(
+      size, allocation, read_only_roots().descriptor_array_map());
+  DescriptorArray array = DescriptorArray::cast(obj);
+  array.Initialize(read_only_roots().empty_enum_cache(),
+                   read_only_roots().undefined_value(), number_of_descriptors,
+                   slack);
+  return handle(array, isolate());
+}
+
+template <typename Impl>
+Handle<ClassPositions> FactoryBase<Impl>::NewClassPositions(int start,
+                                                            int end) {
+  Handle<ClassPositions> class_positions = Handle<ClassPositions>::cast(
+      NewStruct(CLASS_POSITIONS_TYPE, AllocationType::kOld));
+  class_positions->set_start(start);
+  class_positions->set_end(end);
+  return class_positions;
+}
+
+template <typename Impl>
+Handle<SeqOneByteString>
 FactoryBase<Impl>::AllocateRawOneByteInternalizedString(int length,
                                                         uint32_t hash_field) {
   CHECK_GE(String::kMaxLength, length);
@@ -190,8 +687,8 @@ FactoryBase<Impl>::AllocateRawOneByteInternalizedString(int length,
       impl()->CanAllocateInReadOnlySpace() ? AllocationType::kReadOnly
                                            : AllocationType::kOld,
       map);
-  FactoryHandle<Impl, SeqOneByteString> answer =
-      handle(SeqOneByteString::cast(result), impl());
+  Handle<SeqOneByteString> answer =
+      handle(SeqOneByteString::cast(result), isolate());
   answer->set_length(length);
   answer->set_hash_field(hash_field);
   DCHECK_EQ(size, answer->Size());
@@ -199,7 +696,7 @@ FactoryBase<Impl>::AllocateRawOneByteInternalizedString(int length,
 }
 
 template <typename Impl>
-FactoryHandle<Impl, SeqTwoByteString>
+Handle<SeqTwoByteString>
 FactoryBase<Impl>::AllocateRawTwoByteInternalizedString(int length,
                                                         uint32_t hash_field) {
   CHECK_GE(String::kMaxLength, length);
@@ -209,8 +706,8 @@ FactoryBase<Impl>::AllocateRawTwoByteInternalizedString(int length,
   int size = SeqTwoByteString::SizeFor(length);
   HeapObject result =
       AllocateRawWithImmortalMap(size, AllocationType::kOld, map);
-  FactoryHandle<Impl, SeqTwoByteString> answer =
-      handle(SeqTwoByteString::cast(result), impl());
+  Handle<SeqTwoByteString> answer =
+      handle(SeqTwoByteString::cast(result), isolate());
   answer->set_length(length);
   answer->set_hash_field(hash_field);
   DCHECK_EQ(size, result.Size());
@@ -218,6 +715,35 @@ FactoryBase<Impl>::AllocateRawTwoByteInternalizedString(int length,
 }
 
 template <typename Impl>
+HeapObject FactoryBase<Impl>::AllocateRawArray(int size,
+                                               AllocationType allocation) {
+  HeapObject result = AllocateRaw(size, allocation);
+  if (size > kMaxRegularHeapObjectSize && FLAG_use_marking_progress_bar) {
+    MemoryChunk* chunk = MemoryChunk::FromHeapObject(result);
+    chunk->SetFlag<AccessMode::ATOMIC>(MemoryChunk::HAS_PROGRESS_BAR);
+  }
+  return result;
+}
+
+template <typename Impl>
+HeapObject FactoryBase<Impl>::AllocateRawFixedArray(int length,
+                                                    AllocationType allocation) {
+  if (length < 0 || length > FixedArray::kMaxLength) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+  }
+  return AllocateRawArray(FixedArray::SizeFor(length), allocation);
+}
+
+template <typename Impl>
+HeapObject FactoryBase<Impl>::AllocateRawWeakArrayList(
+    int capacity, AllocationType allocation) {
+  if (capacity < 0 || capacity > WeakArrayList::kMaxCapacity) {
+    isolate()->FatalProcessOutOfHeapMemory("invalid array length");
+  }
+  return AllocateRawArray(WeakArrayList::SizeForCapacity(capacity), allocation);
+}
+
+template <typename Impl>
 HeapObject FactoryBase<Impl>::NewWithImmortalMap(Map map,
                                                  AllocationType allocation) {
   return AllocateRawWithImmortalMap(map.instance_size(), allocation, map);
@@ -227,6 +753,10 @@ template <typename Impl>
 HeapObject FactoryBase<Impl>::AllocateRawWithImmortalMap(
     int size, AllocationType allocation, Map map,
     AllocationAlignment alignment) {
+  // TODO(delphick): Potentially you could also pass a immortal immovable Map
+  // from MAP_SPACE here, like external_map or message_object_map, but currently
+  // noone does so this check is sufficient.
+  DCHECK(ReadOnlyHeap::Contains(map));
   HeapObject result = AllocateRaw(size, allocation, alignment);
   result.set_map_after_allocation(map, SKIP_WRITE_BARRIER);
   return result;
diff --git a/deps/v8/src/heap/factory-base.h b/deps/v8/src/heap/factory-base.h
index f49d9ace66..36a193bbf8 100644
--- a/deps/v8/src/heap/factory-base.h
+++ b/deps/v8/src/heap/factory-base.h
@@ -5,57 +5,210 @@
 #ifndef V8_HEAP_FACTORY_BASE_H_
 #define V8_HEAP_FACTORY_BASE_H_
 
+#include "src/base/export-template.h"
 #include "src/common/globals.h"
-#include "src/handles/factory-handles.h"
+#include "src/objects/function-kind.h"
+#include "src/objects/instance-type.h"
 #include "src/roots/roots.h"
 
 namespace v8 {
 namespace internal {
 
 class HeapObject;
+class SharedFunctionInfo;
+class FunctionLiteral;
 class SeqOneByteString;
 class SeqTwoByteString;
+class FreshlyAllocatedBigInt;
+class ObjectBoilerplateDescription;
+class ArrayBoilerplateDescription;
+class TemplateObjectDescription;
+class SourceTextModuleInfo;
+class PreparseData;
+class UncompiledDataWithoutPreparseData;
+class UncompiledDataWithPreparseData;
+class BytecodeArray;
+class CoverageInfo;
+class ClassPositions;
+struct SourceRange;
+template <typename T>
+class ZoneVector;
 
 template <typename Impl>
-class V8_EXPORT_PRIVATE FactoryBase {
+class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) FactoryBase {
  public:
-  FactoryHandle<Impl, SeqOneByteString> NewOneByteInternalizedString(
+  // Converts the given boolean condition to JavaScript boolean value.
+  inline Handle<Oddball> ToBoolean(bool value);
+
+  // Numbers (e.g. literals) are pretenured by the parser.
+  // The return value may be a smi or a heap number.
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<Object> NewNumber(double value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<Object> NewNumberFromInt(int32_t value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<Object> NewNumberFromUint(uint32_t value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<Object> NewNumberFromSize(size_t value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<Object> NewNumberFromInt64(int64_t value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<HeapNumber> NewHeapNumber(double value);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<HeapNumber> NewHeapNumberFromBits(uint64_t bits);
+  template <AllocationType allocation = AllocationType::kYoung>
+  inline Handle<HeapNumber> NewHeapNumberWithHoleNaN();
+
+  template <AllocationType allocation>
+  Handle<HeapNumber> NewHeapNumber();
+
+  Handle<Struct> NewStruct(InstanceType type,
+                           AllocationType allocation = AllocationType::kYoung);
+
+  // Create a pre-tenured empty AccessorPair.
+  Handle<AccessorPair> NewAccessorPair();
+
+  // Allocates a fixed array initialized with undefined values.
+  Handle<FixedArray> NewFixedArray(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  // Allocates a fixed array-like object with given map and initialized with
+  // undefined values.
+  Handle<FixedArray> NewFixedArrayWithMap(
+      Handle<Map> map, int length,
+      AllocationType allocation = AllocationType::kYoung);
+
+  // Allocate a new fixed array with non-existing entries (the hole).
+  Handle<FixedArray> NewFixedArrayWithHoles(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  // Allocate a new uninitialized fixed double array.
+  // The function returns a pre-allocated empty fixed array for length = 0,
+  // so the return type must be the general fixed array class.
+  Handle<FixedArrayBase> NewFixedDoubleArray(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  // Allocates a weak fixed array-like object with given map and initialized
+  // with undefined values.
+  Handle<WeakFixedArray> NewWeakFixedArrayWithMap(
+      Map map, int length, AllocationType allocation = AllocationType::kYoung);
+
+  // Allocates a fixed array which may contain in-place weak references. The
+  // array is initialized with undefined values
+  Handle<WeakFixedArray> NewWeakFixedArray(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  Handle<ByteArray> NewByteArray(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  Handle<BytecodeArray> NewBytecodeArray(int length, const byte* raw_bytecodes,
+                                         int frame_size, int parameter_count,
+                                         Handle<FixedArray> constant_pool);
+
+  // Allocates a fixed array for name-value pairs of boilerplate properties and
+  // calculates the number of properties we need to store in the backing store.
+  Handle<ObjectBoilerplateDescription> NewObjectBoilerplateDescription(
+      int boilerplate, int all_properties, int index_keys, bool has_seen_proto);
+
+  // Create a new ArrayBoilerplateDescription struct.
+  Handle<ArrayBoilerplateDescription> NewArrayBoilerplateDescription(
+      ElementsKind elements_kind, Handle<FixedArrayBase> constant_values);
+
+  // Create a new TemplateObjectDescription struct.
+  Handle<TemplateObjectDescription> NewTemplateObjectDescription(
+      Handle<FixedArray> raw_strings, Handle<FixedArray> cooked_strings);
+
+  Handle<Script> NewScript(Handle<String> source);
+  Handle<Script> NewScriptWithId(Handle<String> source, int script_id);
+
+  Handle<SharedFunctionInfo> NewSharedFunctionInfoForLiteral(
+      FunctionLiteral* literal, Handle<Script> script, bool is_toplevel);
+
+  Handle<PreparseData> NewPreparseData(int data_length, int children_length);
+
+  Handle<UncompiledDataWithoutPreparseData>
+  NewUncompiledDataWithoutPreparseData(Handle<String> inferred_name,
+                                       int32_t start_position,
+                                       int32_t end_position);
+
+  Handle<UncompiledDataWithPreparseData> NewUncompiledDataWithPreparseData(
+      Handle<String> inferred_name, int32_t start_position,
+      int32_t end_position, Handle<PreparseData>);
+
+  // Allocates a FeedbackMedata object and zeroes the data section.
+  Handle<FeedbackMetadata> NewFeedbackMetadata(
+      int slot_count, int feedback_cell_count,
+      AllocationType allocation = AllocationType::kOld);
+
+  Handle<CoverageInfo> NewCoverageInfo(const ZoneVector<SourceRange>& slots);
+
+  Handle<SeqOneByteString> NewOneByteInternalizedString(
       const Vector<const uint8_t>& str, uint32_t hash_field);
-  FactoryHandle<Impl, SeqTwoByteString> NewTwoByteInternalizedString(
+  Handle<SeqTwoByteString> NewTwoByteInternalizedString(
       const Vector<const uc16>& str, uint32_t hash_field);
 
-  FactoryHandle<Impl, SeqOneByteString> AllocateRawOneByteInternalizedString(
+  Handle<SeqOneByteString> AllocateRawOneByteInternalizedString(
       int length, uint32_t hash_field);
-  FactoryHandle<Impl, SeqTwoByteString> AllocateRawTwoByteInternalizedString(
+  Handle<SeqTwoByteString> AllocateRawTwoByteInternalizedString(
       int length, uint32_t hash_field);
 
   // Allocates and partially initializes an one-byte or two-byte String. The
   // characters of the string are uninitialized. Currently used in regexp code
   // only, where they are pretenured.
-  V8_WARN_UNUSED_RESULT FactoryMaybeHandle<Impl, SeqOneByteString>
-  NewRawOneByteString(int length,
-                      AllocationType allocation = AllocationType::kYoung);
-  V8_WARN_UNUSED_RESULT FactoryMaybeHandle<Impl, SeqTwoByteString>
-  NewRawTwoByteString(int length,
-                      AllocationType allocation = AllocationType::kYoung);
+  V8_WARN_UNUSED_RESULT MaybeHandle<SeqOneByteString> NewRawOneByteString(
+      int length, AllocationType allocation = AllocationType::kYoung);
+  V8_WARN_UNUSED_RESULT MaybeHandle<SeqTwoByteString> NewRawTwoByteString(
+      int length, AllocationType allocation = AllocationType::kYoung);
   // Create a new cons string object which consists of a pair of strings.
-  V8_WARN_UNUSED_RESULT FactoryMaybeHandle<Impl, String> NewConsString(
-      FactoryHandle<Impl, String> left, FactoryHandle<Impl, String> right,
+  V8_WARN_UNUSED_RESULT MaybeHandle<String> NewConsString(
+      Handle<String> left, Handle<String> right,
+      AllocationType allocation = AllocationType::kYoung);
+
+  V8_WARN_UNUSED_RESULT Handle<String> NewConsString(
+      Handle<String> left, Handle<String> right, int length, bool one_byte,
       AllocationType allocation = AllocationType::kYoung);
 
-  V8_WARN_UNUSED_RESULT FactoryHandle<Impl, String> NewConsString(
-      FactoryHandle<Impl, String> left, FactoryHandle<Impl, String> right,
-      int length, bool one_byte,
+  // Allocates a new BigInt with {length} digits. Only to be used by
+  // MutableBigInt::New*.
+  Handle<FreshlyAllocatedBigInt> NewBigInt(
+      int length, AllocationType allocation = AllocationType::kYoung);
+
+  // Create a serialized scope info.
+  Handle<ScopeInfo> NewScopeInfo(int length,
+                                 AllocationType type = AllocationType::kOld);
+
+  Handle<SourceTextModuleInfo> NewSourceTextModuleInfo();
+
+  Handle<DescriptorArray> NewDescriptorArray(
+      int number_of_entries, int slack = 0,
       AllocationType allocation = AllocationType::kYoung);
 
+  Handle<ClassPositions> NewClassPositions(int start, int end);
+
  protected:
+  // Allocate memory for an uninitialized array (e.g., a FixedArray or similar).
+  HeapObject AllocateRawArray(int size, AllocationType allocation);
+  HeapObject AllocateRawFixedArray(int length, AllocationType allocation);
+  HeapObject AllocateRawWeakArrayList(int length, AllocationType allocation);
+
   HeapObject AllocateRawWithImmortalMap(
       int size, AllocationType allocation, Map map,
       AllocationAlignment alignment = kWordAligned);
   HeapObject NewWithImmortalMap(Map map, AllocationType allocation);
 
+  Handle<FixedArray> NewFixedArrayWithFiller(Handle<Map> map, int length,
+                                             Handle<Oddball> filler,
+                                             AllocationType allocation);
+
+  Handle<SharedFunctionInfo> NewSharedFunctionInfo();
+  Handle<SharedFunctionInfo> NewSharedFunctionInfo(
+      MaybeHandle<String> maybe_name,
+      MaybeHandle<HeapObject> maybe_function_data, int maybe_builtin_index,
+      FunctionKind kind = kNormalFunction);
+
  private:
   Impl* impl() { return static_cast<Impl*>(this); }
+  auto isolate() { return impl()->isolate(); }
   ReadOnlyRoots read_only_roots() { return impl()->read_only_roots(); }
 
   HeapObject AllocateRaw(int size, AllocationType allocation,
diff --git a/deps/v8/src/heap/factory-inl.h b/deps/v8/src/heap/factory-inl.h
index 77d03e6d47..65d7ebbf98 100644
--- a/deps/v8/src/heap/factory-inl.h
+++ b/deps/v8/src/heap/factory-inl.h
@@ -11,6 +11,7 @@
 // Do not include anything from src/heap here!
 #include "src/execution/isolate-inl.h"
 #include "src/handles/handles-inl.h"
+#include "src/heap/factory-base-inl.h"
 #include "src/objects/feedback-cell.h"
 #include "src/objects/heap-number-inl.h"
 #include "src/objects/objects-inl.h"
@@ -43,43 +44,6 @@ Handle<String> Factory::NewSubString(Handle<String> str, int begin, int end) {
   return NewProperSubString(str, begin, end);
 }
 
-Handle<Object> Factory::NewNumberFromSize(size_t value) {
-  // We can't use Smi::IsValid() here because that operates on a signed
-  // intptr_t, and casting from size_t could create a bogus sign bit.
-  if (value <= static_cast<size_t>(Smi::kMaxValue)) {
-    return Handle<Object>(Smi::FromIntptr(static_cast<intptr_t>(value)),
-                          isolate());
-  }
-  return NewHeapNumber(static_cast<double>(value));
-}
-
-Handle<Object> Factory::NewNumberFromInt64(int64_t value) {
-  if (value <= std::numeric_limits<int32_t>::max() &&
-      value >= std::numeric_limits<int32_t>::min() &&
-      Smi::IsValid(static_cast<int32_t>(value))) {
-    return Handle<Object>(Smi::FromInt(static_cast<int32_t>(value)), isolate());
-  }
-  return NewHeapNumber(static_cast<double>(value));
-}
-
-template <AllocationType allocation>
-Handle<HeapNumber> Factory::NewHeapNumber(double value) {
-  Handle<HeapNumber> heap_number = NewHeapNumber<allocation>();
-  heap_number->set_value(value);
-  return heap_number;
-}
-
-template <AllocationType allocation>
-Handle<HeapNumber> Factory::NewHeapNumberFromBits(uint64_t bits) {
-  Handle<HeapNumber> heap_number = NewHeapNumber<allocation>();
-  heap_number->set_value_as_bits(bits);
-  return heap_number;
-}
-
-Handle<HeapNumber> Factory::NewHeapNumberWithHoleNaN() {
-  return NewHeapNumberFromBits(kHoleNanInt64);
-}
-
 Handle<JSArray> Factory::NewJSArrayWithElements(Handle<FixedArrayBase> elements,
                                                 ElementsKind elements_kind,
                                                 AllocationType allocation) {
@@ -101,11 +65,6 @@ Handle<Object> Factory::NewURIError() {
                   MessageTemplate::kURIMalformed);
 }
 
-template <typename T>
-inline MaybeHandle<T> Factory::Throw(Handle<Object> exception) {
-  return isolate()->Throw<T>(exception);
-}
-
 ReadOnlyRoots Factory::read_only_roots() { return ReadOnlyRoots(isolate()); }
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/factory.cc b/deps/v8/src/heap/factory.cc
index 56c61b53e6..933a51425f 100644
--- a/deps/v8/src/heap/factory.cc
+++ b/deps/v8/src/heap/factory.cc
@@ -10,7 +10,6 @@
 #include <utility>  // For move
 
 #include "src/ast/ast-source-ranges.h"
-#include "src/ast/ast.h"
 #include "src/base/bits.h"
 #include "src/builtins/accessors.h"
 #include "src/builtins/constants-table-builder.h"
@@ -221,10 +220,6 @@ Handle<Code> Factory::CodeBuilder::Build() {
   return BuildInternal(true).ToHandleChecked();
 }
 
-void Factory::FatalProcessOutOfHeapMemory(const char* location) {
-  isolate()->heap()->FatalProcessOutOfMemory(location);
-}
-
 HeapObject Factory::AllocateRaw(int size, AllocationType allocation,
                                 AllocationAlignment alignment) {
   return isolate()->heap()->AllocateRawWith<Heap::kRetryOrFail>(
@@ -261,32 +256,6 @@ void Factory::InitializeAllocationMemento(AllocationMemento memento,
   }
 }
 
-HeapObject Factory::AllocateRawArray(int size, AllocationType allocation) {
-  HeapObject result =
-      isolate()->heap()->AllocateRawWith<Heap::kRetryOrFail>(size, allocation);
-  if (size > kMaxRegularHeapObjectSize && FLAG_use_marking_progress_bar) {
-    MemoryChunk* chunk = MemoryChunk::FromHeapObject(result);
-    chunk->SetFlag<AccessMode::ATOMIC>(MemoryChunk::HAS_PROGRESS_BAR);
-  }
-  return result;
-}
-
-HeapObject Factory::AllocateRawFixedArray(int length,
-                                          AllocationType allocation) {
-  if (length < 0 || length > FixedArray::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-  return AllocateRawArray(FixedArray::SizeFor(length), allocation);
-}
-
-HeapObject Factory::AllocateRawWeakArrayList(int capacity,
-                                             AllocationType allocation) {
-  if (capacity < 0 || capacity > WeakArrayList::kMaxCapacity) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-  return AllocateRawArray(WeakArrayList::SizeForCapacity(capacity), allocation);
-}
-
 HeapObject Factory::New(Handle<Map> map, AllocationType allocation) {
   DCHECK(map->instance_type() != MAP_TYPE);
   int size = map->instance_size();
@@ -323,8 +292,8 @@ Handle<PrototypeInfo> Factory::NewPrototypeInfo() {
 
 Handle<EnumCache> Factory::NewEnumCache(Handle<FixedArray> keys,
                                         Handle<FixedArray> indices) {
-  Handle<EnumCache> result = Handle<EnumCache>::cast(
-      NewStruct(ENUM_CACHE_TYPE, AllocationType::kOld));
+  Handle<EnumCache> result =
+      Handle<EnumCache>::cast(NewStruct(ENUM_CACHE_TYPE, AllocationType::kOld));
   result->set_keys(*keys);
   result->set_indices(*indices);
   return result;
@@ -339,28 +308,6 @@ Handle<Tuple2> Factory::NewTuple2(Handle<Object> value1, Handle<Object> value2,
   return result;
 }
 
-Handle<ArrayBoilerplateDescription> Factory::NewArrayBoilerplateDescription(
-    ElementsKind elements_kind, Handle<FixedArrayBase> constant_values) {
-  Handle<ArrayBoilerplateDescription> result =
-      Handle<ArrayBoilerplateDescription>::cast(
-          NewStruct(ARRAY_BOILERPLATE_DESCRIPTION_TYPE, AllocationType::kOld));
-  result->set_elements_kind(elements_kind);
-  result->set_constant_elements(*constant_values);
-  return result;
-}
-
-Handle<TemplateObjectDescription> Factory::NewTemplateObjectDescription(
-    Handle<FixedArray> raw_strings, Handle<FixedArray> cooked_strings) {
-  DCHECK_EQ(raw_strings->length(), cooked_strings->length());
-  DCHECK_LT(0, raw_strings->length());
-  Handle<TemplateObjectDescription> result =
-      Handle<TemplateObjectDescription>::cast(
-          NewStruct(TEMPLATE_OBJECT_DESCRIPTION_TYPE, AllocationType::kOld));
-  result->set_raw_strings(*raw_strings);
-  result->set_cooked_strings(*cooked_strings);
-  return result;
-}
-
 Handle<Oddball> Factory::NewOddball(Handle<Map> map, const char* to_string,
                                     Handle<Object> to_number,
                                     const char* type_of, byte kind) {
@@ -387,78 +334,6 @@ Handle<PropertyArray> Factory::NewPropertyArray(int length) {
   return array;
 }
 
-Handle<FixedArray> Factory::NewFixedArrayWithFiller(RootIndex map_root_index,
-                                                    int length, Object filler,
-                                                    AllocationType allocation) {
-  HeapObject result = AllocateRawFixedArray(length, allocation);
-  DCHECK(RootsTable::IsImmortalImmovable(map_root_index));
-  Map map = Map::cast(isolate()->root(map_root_index));
-  result.set_map_after_allocation(map, SKIP_WRITE_BARRIER);
-  Handle<FixedArray> array(FixedArray::cast(result), isolate());
-  array->set_length(length);
-  MemsetTagged(array->data_start(), filler, length);
-  return array;
-}
-
-template <typename T>
-Handle<T> Factory::NewFixedArrayWithMap(RootIndex map_root_index, int length,
-                                        AllocationType allocation) {
-  static_assert(std::is_base_of<FixedArray, T>::value,
-                "T must be a descendant of FixedArray");
-  // Zero-length case must be handled outside, where the knowledge about
-  // the map is.
-  DCHECK_LT(0, length);
-  return Handle<T>::cast(NewFixedArrayWithFiller(
-      map_root_index, length, *undefined_value(), allocation));
-}
-
-template <typename T>
-Handle<T> Factory::NewWeakFixedArrayWithMap(RootIndex map_root_index,
-                                            int length,
-                                            AllocationType allocation) {
-  static_assert(std::is_base_of<WeakFixedArray, T>::value,
-                "T must be a descendant of WeakFixedArray");
-
-  // Zero-length case must be handled outside.
-  DCHECK_LT(0, length);
-
-  HeapObject result =
-      AllocateRawArray(WeakFixedArray::SizeFor(length), AllocationType::kOld);
-  Map map = Map::cast(isolate()->root(map_root_index));
-  result.set_map_after_allocation(map, SKIP_WRITE_BARRIER);
-
-  Handle<WeakFixedArray> array(WeakFixedArray::cast(result), isolate());
-  array->set_length(length);
-  MemsetTagged(ObjectSlot(array->data_start()), *undefined_value(), length);
-
-  return Handle<T>::cast(array);
-}
-
-template Handle<FixedArray> Factory::NewFixedArrayWithMap<FixedArray>(
-    RootIndex, int, AllocationType allocation);
-
-Handle<FixedArray> Factory::NewFixedArray(int length,
-                                          AllocationType allocation) {
-  DCHECK_LE(0, length);
-  if (length == 0) return empty_fixed_array();
-  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
-                                 *undefined_value(), allocation);
-}
-
-Handle<WeakFixedArray> Factory::NewWeakFixedArray(int length,
-                                                  AllocationType allocation) {
-  DCHECK_LE(0, length);
-  if (length == 0) return empty_weak_fixed_array();
-  HeapObject result =
-      AllocateRawArray(WeakFixedArray::SizeFor(length), allocation);
-  DCHECK(RootsTable::IsImmortalImmovable(RootIndex::kWeakFixedArrayMap));
-  result.set_map_after_allocation(*weak_fixed_array_map(), SKIP_WRITE_BARRIER);
-  Handle<WeakFixedArray> array(WeakFixedArray::cast(result), isolate());
-  array->set_length(length);
-  MemsetTagged(ObjectSlot(array->data_start()), *undefined_value(), length);
-  return array;
-}
-
 MaybeHandle<FixedArray> Factory::TryNewFixedArray(
     int length, AllocationType allocation_type) {
   DCHECK_LE(0, length);
@@ -481,14 +356,6 @@ MaybeHandle<FixedArray> Factory::TryNewFixedArray(
   return array;
 }
 
-Handle<FixedArray> Factory::NewFixedArrayWithHoles(int length,
-                                                   AllocationType allocation) {
-  DCHECK_LE(0, length);
-  if (length == 0) return empty_fixed_array();
-  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
-                                 *the_hole_value(), allocation);
-}
-
 Handle<FixedArray> Factory::NewUninitializedFixedArray(int length) {
   if (length == 0) return empty_fixed_array();
   if (length < 0 || length > FixedArray::kMaxLength) {
@@ -498,8 +365,9 @@ Handle<FixedArray> Factory::NewUninitializedFixedArray(int length) {
   // TODO(ulan): As an experiment this temporarily returns an initialized fixed
   // array. After getting canary/performance coverage, either remove the
   // function or revert to returning uninitilized array.
-  return NewFixedArrayWithFiller(RootIndex::kFixedArrayMap, length,
-                                 *undefined_value(), AllocationType::kYoung);
+  return NewFixedArrayWithFiller(read_only_roots().fixed_array_map_handle(),
+                                 length, undefined_value(),
+                                 AllocationType::kYoung);
 }
 
 Handle<ClosureFeedbackCellArray> Factory::NewClosureFeedbackCellArray(
@@ -507,9 +375,9 @@ Handle<ClosureFeedbackCellArray> Factory::NewClosureFeedbackCellArray(
   if (length == 0) return empty_closure_feedback_cell_array();
 
   Handle<ClosureFeedbackCellArray> feedback_cell_array =
-      NewFixedArrayWithMap<ClosureFeedbackCellArray>(
-          RootIndex::kClosureFeedbackCellArrayMap, length,
-          AllocationType::kOld);
+      Handle<ClosureFeedbackCellArray>::cast(NewFixedArrayWithMap(
+          read_only_roots().closure_feedback_cell_array_map_handle(), length,
+          AllocationType::kOld));
 
   return feedback_cell_array;
 }
@@ -557,56 +425,6 @@ Handle<EmbedderDataArray> Factory::NewEmbedderDataArray(int length) {
   return array;
 }
 
-Handle<ObjectBoilerplateDescription> Factory::NewObjectBoilerplateDescription(
-    int boilerplate, int all_properties, int index_keys, bool has_seen_proto) {
-  DCHECK_GE(boilerplate, 0);
-  DCHECK_GE(all_properties, index_keys);
-  DCHECK_GE(index_keys, 0);
-
-  int backing_store_size =
-      all_properties - index_keys - (has_seen_proto ? 1 : 0);
-  DCHECK_GE(backing_store_size, 0);
-  bool has_different_size_backing_store = boilerplate != backing_store_size;
-
-  // Space for name and value for every boilerplate property + LiteralType flag.
-  int size =
-      2 * boilerplate + ObjectBoilerplateDescription::kDescriptionStartIndex;
-
-  if (has_different_size_backing_store) {
-    // An extra entry for the backing store size.
-    size++;
-  }
-
-  Handle<ObjectBoilerplateDescription> description =
-      Handle<ObjectBoilerplateDescription>::cast(
-          NewFixedArrayWithMap(RootIndex::kObjectBoilerplateDescriptionMap,
-                               size, AllocationType::kOld));
-
-  if (has_different_size_backing_store) {
-    DCHECK_IMPLIES((boilerplate == (all_properties - index_keys)),
-                   has_seen_proto);
-    description->set_backing_store_size(backing_store_size);
-  }
-
-  description->set_flags(0);
-
-  return description;
-}
-
-Handle<FixedArrayBase> Factory::NewFixedDoubleArray(int length) {
-  if (length == 0) return empty_fixed_array();
-  if (length < 0 || length > FixedDoubleArray::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-  int size = FixedDoubleArray::SizeFor(length);
-  Map map = *fixed_double_array_map();
-  HeapObject result = AllocateRawWithImmortalMap(size, AllocationType::kYoung,
-                                                 map, kDoubleAligned);
-  Handle<FixedDoubleArray> array(FixedDoubleArray::cast(result), isolate());
-  array->set_length(length);
-  return array;
-}
-
 Handle<FixedArrayBase> Factory::NewFixedDoubleArrayWithHoles(int length) {
   DCHECK_LE(0, length);
   Handle<FixedArrayBase> array = NewFixedDoubleArray(length);
@@ -616,25 +434,6 @@ Handle<FixedArrayBase> Factory::NewFixedDoubleArrayWithHoles(int length) {
   return array;
 }
 
-Handle<FeedbackMetadata> Factory::NewFeedbackMetadata(
-    int slot_count, int feedback_cell_count, AllocationType allocation) {
-  DCHECK_LE(0, slot_count);
-  int size = FeedbackMetadata::SizeFor(slot_count);
-  HeapObject result =
-      AllocateRawWithImmortalMap(size, allocation, *feedback_metadata_map());
-  Handle<FeedbackMetadata> data(FeedbackMetadata::cast(result), isolate());
-  data->set_slot_count(slot_count);
-  data->set_closure_feedback_cell_count(feedback_cell_count);
-
-  // Initialize the data section to 0.
-  int data_size = size - FeedbackMetadata::kHeaderSize;
-  Address data_start = data->address() + FeedbackMetadata::kHeaderSize;
-  memset(reinterpret_cast<byte*>(data_start), 0, data_size);
-  // Fields have been zeroed out but not initialized, so this object will not
-  // pass object verification at this point.
-  return data;
-}
-
 Handle<FrameArray> Factory::NewFrameArray(int number_of_frames) {
   DCHECK_LE(0, number_of_frames);
   Handle<FixedArray> result =
@@ -702,19 +501,11 @@ Handle<OrderedNameDictionary> Factory::NewOrderedNameDictionary() {
       .ToHandleChecked();
 }
 
-Handle<AccessorPair> Factory::NewAccessorPair() {
-  Handle<AccessorPair> accessors = Handle<AccessorPair>::cast(
-      NewStruct(ACCESSOR_PAIR_TYPE, AllocationType::kOld));
-  accessors->set_getter(*null_value(), SKIP_WRITE_BARRIER);
-  accessors->set_setter(*null_value(), SKIP_WRITE_BARRIER);
-  return accessors;
-}
-
 Handle<PropertyDescriptorObject> Factory::NewPropertyDescriptorObject() {
   Handle<PropertyDescriptorObject> object =
       Handle<PropertyDescriptorObject>::cast(
           NewStruct(PROPERTY_DESCRIPTOR_OBJECT_TYPE, AllocationType::kYoung));
-  object->set_flags(Smi::zero());
+  object->set_flags(0);
   object->set_value(*the_hole_value(), SKIP_WRITE_BARRIER);
   object->set_get(*the_hole_value(), SKIP_WRITE_BARRIER);
   object->set_set(*the_hole_value(), SKIP_WRITE_BARRIER);
@@ -1200,7 +991,7 @@ Handle<Symbol> Factory::NewSymbol(AllocationType allocation) {
   int hash = isolate()->GenerateIdentityHash(Name::kHashBitMask);
 
   Handle<Symbol> symbol(Symbol::cast(result), isolate());
-  symbol->set_hash_field(Name::kIsNotArrayIndexMask |
+  symbol->set_hash_field(Name::kIsNotIntegerIndexMask |
                          (hash << Name::kHashShift));
   symbol->set_description(*undefined_value());
   symbol->set_flags(0);
@@ -1278,9 +1069,9 @@ Handle<Context> Factory::NewScriptContext(Handle<NativeContext> outer,
 }
 
 Handle<ScriptContextTable> Factory::NewScriptContextTable() {
-  Handle<ScriptContextTable> context_table =
-      NewFixedArrayWithMap<ScriptContextTable>(
-          RootIndex::kScriptContextTableMap, ScriptContextTable::kMinLength);
+  Handle<ScriptContextTable> context_table = Handle<ScriptContextTable>::cast(
+      NewFixedArrayWithMap(read_only_roots().script_context_table_map_handle(),
+                           ScriptContextTable::kMinLength));
   context_table->set_used(0);
   return context_table;
 }
@@ -1401,16 +1192,6 @@ Handle<Context> Factory::NewBuiltinContext(Handle<NativeContext> native_context,
   return context;
 }
 
-Handle<Struct> Factory::NewStruct(InstanceType type,
-                                  AllocationType allocation) {
-  Map map = Map::GetStructMap(isolate(), type);
-  int size = map.instance_size();
-  HeapObject result = AllocateRawWithImmortalMap(size, allocation, map);
-  Handle<Struct> str(Struct::cast(result), isolate());
-  str->InitializeBody(size);
-  return str;
-}
-
 Handle<AliasedArgumentsEntry> Factory::NewAliasedArgumentsEntry(
     int aliased_context_slot) {
   Handle<AliasedArgumentsEntry> entry = Handle<AliasedArgumentsEntry>::cast(
@@ -1436,41 +1217,16 @@ Handle<AccessorInfo> Factory::NewAccessorInfo() {
   return info;
 }
 
-Handle<Script> Factory::NewScript(Handle<String> source) {
-  return NewScriptWithId(source, isolate()->heap()->NextScriptId());
-}
-
-Handle<Script> Factory::NewScriptWithId(Handle<String> source, int script_id) {
-  // Create and initialize script object.
-  Heap* heap = isolate()->heap();
-  ReadOnlyRoots roots(heap);
-  Handle<Script> script =
-      Handle<Script>::cast(NewStruct(SCRIPT_TYPE, AllocationType::kOld));
-  script->set_source(*source);
-  script->set_name(roots.undefined_value());
-  script->set_id(script_id);
-  script->set_line_offset(0);
-  script->set_column_offset(0);
-  script->set_context_data(roots.undefined_value());
-  script->set_type(Script::TYPE_NORMAL);
-  script->set_line_ends(roots.undefined_value());
-  script->set_eval_from_shared_or_wrapped_arguments(roots.undefined_value());
-  script->set_eval_from_position(0);
-  script->set_shared_function_infos(*empty_weak_fixed_array(),
-                                    SKIP_WRITE_BARRIER);
-  script->set_flags(0);
-  script->set_host_defined_options(*empty_fixed_array());
+void Factory::AddToScriptList(Handle<Script> script) {
   Handle<WeakArrayList> scripts = script_list();
   scripts = WeakArrayList::Append(isolate(), scripts,
                                   MaybeObjectHandle::Weak(script));
-  heap->set_script_list(*scripts);
-  LOG(isolate(), ScriptEvent(Logger::ScriptEventType::kCreate, script_id));
-  return script;
+  isolate()->heap()->set_script_list(*scripts);
 }
 
 Handle<Script> Factory::CloneScript(Handle<Script> script) {
   Heap* heap = isolate()->heap();
-  int script_id = isolate()->heap()->NextScriptId();
+  int script_id = isolate()->GetNextScriptId();
   Handle<Script> new_script =
       Handle<Script>::cast(NewStruct(SCRIPT_TYPE, AllocationType::kOld));
   new_script->set_source(script->source());
@@ -1540,50 +1296,6 @@ Handle<Foreign> Factory::NewForeign(Address addr) {
   return foreign;
 }
 
-Handle<ByteArray> Factory::NewByteArray(int length, AllocationType allocation) {
-  if (length < 0 || length > ByteArray::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-  int size = ByteArray::SizeFor(length);
-  HeapObject result =
-      AllocateRawWithImmortalMap(size, allocation, *byte_array_map());
-  Handle<ByteArray> array(ByteArray::cast(result), isolate());
-  array->set_length(length);
-  array->clear_padding();
-  return array;
-}
-
-Handle<BytecodeArray> Factory::NewBytecodeArray(
-    int length, const byte* raw_bytecodes, int frame_size, int parameter_count,
-    Handle<FixedArray> constant_pool) {
-  if (length < 0 || length > BytecodeArray::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid array length");
-  }
-  // Bytecode array is AllocationType::kOld, so constant pool array should be
-  // too.
-  DCHECK(!Heap::InYoungGeneration(*constant_pool));
-
-  int size = BytecodeArray::SizeFor(length);
-  HeapObject result = AllocateRawWithImmortalMap(size, AllocationType::kOld,
-                                                 *bytecode_array_map());
-  Handle<BytecodeArray> instance(BytecodeArray::cast(result), isolate());
-  instance->set_length(length);
-  instance->set_frame_size(frame_size);
-  instance->set_parameter_count(parameter_count);
-  instance->set_incoming_new_target_or_generator_register(
-      interpreter::Register::invalid_value());
-  instance->set_osr_loop_nesting_level(0);
-  instance->set_bytecode_age(BytecodeArray::kNoAgeBytecodeAge);
-  instance->set_constant_pool(*constant_pool);
-  instance->set_handler_table(*empty_byte_array());
-  instance->set_source_position_table(*undefined_value());
-  CopyBytes(reinterpret_cast<byte*>(instance->GetFirstBytecodeAddress()),
-            raw_bytecodes, length);
-  instance->clear_padding();
-
-  return instance;
-}
-
 Handle<Cell> Factory::NewCell(Handle<Object> value) {
   STATIC_ASSERT(Cell::kSize <= kMaxRegularHeapObjectSize);
   HeapObject result = AllocateRawWithImmortalMap(
@@ -1594,31 +1306,34 @@ Handle<Cell> Factory::NewCell(Handle<Object> value) {
 }
 
 Handle<FeedbackCell> Factory::NewNoClosuresCell(Handle<HeapObject> value) {
-  HeapObject result = AllocateRawWithImmortalMap(FeedbackCell::kAlignedSize,
-      AllocationType::kOld, *no_closures_cell_map());
+  HeapObject result =
+      AllocateRawWithImmortalMap(FeedbackCell::kAlignedSize,
+                                 AllocationType::kOld, *no_closures_cell_map());
   Handle<FeedbackCell> cell(FeedbackCell::cast(result), isolate());
   cell->set_value(*value);
-  cell->set_interrupt_budget(FeedbackCell::GetInitialInterruptBudget());
+  cell->SetInitialInterruptBudget();
   cell->clear_padding();
   return cell;
 }
 
 Handle<FeedbackCell> Factory::NewOneClosureCell(Handle<HeapObject> value) {
-  HeapObject result = AllocateRawWithImmortalMap(FeedbackCell::kAlignedSize,
-      AllocationType::kOld, *one_closure_cell_map());
+  HeapObject result =
+      AllocateRawWithImmortalMap(FeedbackCell::kAlignedSize,
+                                 AllocationType::kOld, *one_closure_cell_map());
   Handle<FeedbackCell> cell(FeedbackCell::cast(result), isolate());
   cell->set_value(*value);
-  cell->set_interrupt_budget(FeedbackCell::GetInitialInterruptBudget());
+  cell->SetInitialInterruptBudget();
   cell->clear_padding();
   return cell;
 }
 
 Handle<FeedbackCell> Factory::NewManyClosuresCell(Handle<HeapObject> value) {
   HeapObject result = AllocateRawWithImmortalMap(FeedbackCell::kAlignedSize,
-      AllocationType::kOld, *many_closures_cell_map());
+                                                 AllocationType::kOld,
+                                                 *many_closures_cell_map());
   Handle<FeedbackCell> cell(FeedbackCell::cast(result), isolate());
   cell->set_value(*value);
-  cell->set_interrupt_budget(FeedbackCell::GetInitialInterruptBudget());
+  cell->SetInitialInterruptBudget();
   cell->clear_padding();
   return cell;
 }
@@ -1638,26 +1353,12 @@ Handle<PropertyCell> Factory::NewPropertyCell(Handle<Name> name,
   return cell;
 }
 
-Handle<DescriptorArray> Factory::NewDescriptorArray(int number_of_descriptors,
-                                                    int slack) {
-  int number_of_all_descriptors = number_of_descriptors + slack;
-  // Zero-length case must be handled outside.
-  DCHECK_LT(0, number_of_all_descriptors);
-  int size = DescriptorArray::SizeFor(number_of_all_descriptors);
-  HeapObject obj = isolate()->heap()->AllocateRawWith<Heap::kRetryOrFail>(
-      size, AllocationType::kYoung);
-  obj.set_map_after_allocation(*descriptor_array_map(), SKIP_WRITE_BARRIER);
-  DescriptorArray array = DescriptorArray::cast(obj);
-  array.Initialize(*empty_enum_cache(), *undefined_value(),
-                   number_of_descriptors, slack);
-  return Handle<DescriptorArray>(array, isolate());
-}
-
 Handle<TransitionArray> Factory::NewTransitionArray(int number_of_transitions,
                                                     int slack) {
   int capacity = TransitionArray::LengthFor(number_of_transitions + slack);
-  Handle<TransitionArray> array = NewWeakFixedArrayWithMap<TransitionArray>(
-      RootIndex::kTransitionArrayMap, capacity, AllocationType::kOld);
+  Handle<TransitionArray> array = Handle<TransitionArray>::cast(
+      NewWeakFixedArrayWithMap(read_only_roots().transition_array_map(),
+                               capacity, AllocationType::kOld));
   // Transition arrays are AllocationType::kOld. When black allocation is on we
   // have to add the transition array to the list of
   // encountered_transition_arrays.
@@ -2019,71 +1720,12 @@ Handle<FixedDoubleArray> Factory::CopyFixedDoubleArray(
   return result;
 }
 
-template <AllocationType allocation>
-Handle<Object> Factory::NewNumber(double value) {
-  // Materialize as a SMI if possible.
-  int32_t int_value;
-  if (DoubleToSmiInteger(value, &int_value)) {
-    return handle(Smi::FromInt(int_value), isolate());
-  }
-  return NewHeapNumber<allocation>(value);
-}
-
-template Handle<Object> V8_EXPORT_PRIVATE
-Factory::NewNumber<AllocationType::kYoung>(double);
-template Handle<Object> V8_EXPORT_PRIVATE
-Factory::NewNumber<AllocationType::kOld>(double);
-template Handle<Object> V8_EXPORT_PRIVATE
-Factory::NewNumber<AllocationType::kReadOnly>(double);
-
-Handle<Object> Factory::NewNumberFromInt(int32_t value) {
-  if (Smi::IsValid(value)) return handle(Smi::FromInt(value), isolate());
-  // Bypass NewNumber to avoid various redundant checks.
-  return NewHeapNumber(FastI2D(value));
-}
-
-Handle<Object> Factory::NewNumberFromUint(uint32_t value) {
-  int32_t int32v = static_cast<int32_t>(value);
-  if (int32v >= 0 && Smi::IsValid(int32v)) {
-    return handle(Smi::FromInt(int32v), isolate());
-  }
-  return NewHeapNumber(FastUI2D(value));
-}
-
-template <AllocationType allocation>
-Handle<HeapNumber> Factory::NewHeapNumber() {
-  STATIC_ASSERT(HeapNumber::kSize <= kMaxRegularHeapObjectSize);
-  Map map = *heap_number_map();
-  HeapObject result = AllocateRawWithImmortalMap(HeapNumber::kSize, allocation,
-                                                 map, kDoubleUnaligned);
-  return handle(HeapNumber::cast(result), isolate());
-}
-
-template Handle<HeapNumber> V8_EXPORT_PRIVATE
-Factory::NewHeapNumber<AllocationType::kYoung>();
-template Handle<HeapNumber> V8_EXPORT_PRIVATE
-Factory::NewHeapNumber<AllocationType::kOld>();
-template Handle<HeapNumber> V8_EXPORT_PRIVATE
-Factory::NewHeapNumber<AllocationType::kReadOnly>();
-
 Handle<HeapNumber> Factory::NewHeapNumberForCodeAssembler(double value) {
   return isolate()->heap()->CanAllocateInReadOnlySpace()
              ? NewHeapNumber<AllocationType::kReadOnly>(value)
              : NewHeapNumber<AllocationType::kOld>(value);
 }
 
-Handle<FreshlyAllocatedBigInt> Factory::NewBigInt(int length,
-                                                  AllocationType allocation) {
-  if (length < 0 || length > BigInt::kMaxLength) {
-    isolate()->heap()->FatalProcessOutOfMemory("invalid BigInt length");
-  }
-  HeapObject result = AllocateRawWithImmortalMap(BigInt::SizeFor(length),
-                                                 allocation, *bigint_map());
-  FreshlyAllocatedBigInt bigint = FreshlyAllocatedBigInt::cast(result);
-  bigint.clear_padding();
-  return handle(bigint, isolate());
-}
-
 Handle<JSObject> Factory::NewError(Handle<JSFunction> constructor,
                                    MessageTemplate template_index,
                                    Handle<Object> arg0, Handle<Object> arg1,
@@ -2363,60 +2005,6 @@ Handle<JSFunction> Factory::NewFunctionFromSharedFunctionInfo(
   return result;
 }
 
-Handle<ScopeInfo> Factory::NewScopeInfo(int length, AllocationType type) {
-  DCHECK(type == AllocationType::kOld || type == AllocationType::kReadOnly);
-  return NewFixedArrayWithMap<ScopeInfo>(RootIndex::kScopeInfoMap, length,
-                                         type);
-}
-
-Handle<SourceTextModuleInfo> Factory::NewSourceTextModuleInfo() {
-  return NewFixedArrayWithMap<SourceTextModuleInfo>(
-      RootIndex::kModuleInfoMap, SourceTextModuleInfo::kLength,
-      AllocationType::kOld);
-}
-
-Handle<PreparseData> Factory::NewPreparseData(int data_length,
-                                              int children_length) {
-  int size = PreparseData::SizeFor(data_length, children_length);
-  Handle<PreparseData> result(
-      PreparseData::cast(AllocateRawWithImmortalMap(size, AllocationType::kOld,
-                                                    *preparse_data_map())),
-      isolate());
-  result->set_data_length(data_length);
-  result->set_children_length(children_length);
-  MemsetTagged(result->inner_data_start(), *null_value(), children_length);
-  result->clear_padding();
-  return result;
-}
-
-Handle<UncompiledDataWithoutPreparseData>
-Factory::NewUncompiledDataWithoutPreparseData(Handle<String> inferred_name,
-                                              int32_t start_position,
-                                              int32_t end_position) {
-  Handle<UncompiledDataWithoutPreparseData> result(
-      UncompiledDataWithoutPreparseData::cast(New(
-          uncompiled_data_without_preparse_data_map(), AllocationType::kOld)),
-      isolate());
-
-  result->Init(*inferred_name, start_position, end_position);
-  return result;
-}
-
-Handle<UncompiledDataWithPreparseData>
-Factory::NewUncompiledDataWithPreparseData(Handle<String> inferred_name,
-                                           int32_t start_position,
-                                           int32_t end_position,
-                                           Handle<PreparseData> preparse_data) {
-  Handle<UncompiledDataWithPreparseData> result(
-      UncompiledDataWithPreparseData::cast(
-          New(uncompiled_data_with_preparse_data_map(), AllocationType::kOld)),
-      isolate());
-
-  result->Init(*inferred_name, start_position, end_position, *preparse_data);
-
-  return result;
-}
-
 Handle<JSObject> Factory::NewExternal(void* value) {
   Handle<Foreign> foreign = NewForeign(reinterpret_cast<Address>(value));
   Handle<JSObject> external = NewJSObjectFromMap(external_map());
@@ -3210,18 +2798,6 @@ void Factory::ReinitializeJSGlobalProxy(Handle<JSGlobalProxy> object,
   InitializeJSObjectFromMap(object, raw_properties_or_hash, map);
 }
 
-Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfoForLiteral(
-    FunctionLiteral* literal, Handle<Script> script, bool is_toplevel) {
-  FunctionKind kind = literal->kind();
-  Handle<SharedFunctionInfo> shared = NewSharedFunctionInfoForBuiltin(
-      literal->name(), Builtins::kCompileLazy, kind);
-  SharedFunctionInfo::InitFromFunctionLiteral(isolate(), shared, literal,
-                                              is_toplevel);
-  shared->SetScript(ReadOnlyRoots(isolate()), *script,
-                    literal->function_literal_id(), false);
-  return shared;
-}
-
 Handle<JSMessageObject> Factory::NewJSMessageObject(
     MessageTemplate message, Handle<Object> argument, int start_position,
     int end_position, Handle<SharedFunctionInfo> shared_info,
@@ -3251,7 +2827,7 @@ Handle<JSMessageObject> Factory::NewJSMessageObject(
       DCHECK_EQ(bytecode_offset, -1);
     } else {
       message_obj->set_shared_info(*shared_info);
-      DCHECK_GE(bytecode_offset, 0);
+      DCHECK_GE(bytecode_offset, kFunctionEntryBytecodeOffset);
     }
   }
 
@@ -3281,64 +2857,6 @@ Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfoForBuiltin(
   return shared;
 }
 
-Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
-    MaybeHandle<String> maybe_name, MaybeHandle<HeapObject> maybe_function_data,
-    int maybe_builtin_index, FunctionKind kind) {
-  Handle<SharedFunctionInfo> shared = NewSharedFunctionInfo();
-
-  // Function names are assumed to be flat elsewhere. Must flatten before
-  // allocating SharedFunctionInfo to avoid GC seeing the uninitialized SFI.
-  Handle<String> shared_name;
-  bool has_shared_name = maybe_name.ToHandle(&shared_name);
-  if (has_shared_name) {
-    shared_name = String::Flatten(isolate(), shared_name, AllocationType::kOld);
-    shared->set_name_or_scope_info(*shared_name);
-  } else {
-    DCHECK_EQ(shared->name_or_scope_info(),
-              SharedFunctionInfo::kNoSharedNameSentinel);
-  }
-
-  Handle<HeapObject> function_data;
-  if (maybe_function_data.ToHandle(&function_data)) {
-    // If we pass function_data then we shouldn't pass a builtin index, and
-    // the function_data should not be code with a builtin.
-    DCHECK(!Builtins::IsBuiltinId(maybe_builtin_index));
-    DCHECK_IMPLIES(function_data->IsCode(),
-                   !Code::cast(*function_data).is_builtin());
-    shared->set_function_data(*function_data);
-  } else if (Builtins::IsBuiltinId(maybe_builtin_index)) {
-    shared->set_builtin_id(maybe_builtin_index);
-  } else {
-    shared->set_builtin_id(Builtins::kIllegal);
-  }
-
-  shared->CalculateConstructAsBuiltin();
-  shared->set_kind(kind);
-
-#ifdef VERIFY_HEAP
-  shared->SharedFunctionInfoVerify(isolate());
-#endif  // VERIFY_HEAP
-  return shared;
-}
-
-Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo() {
-  Handle<Map> map = shared_function_info_map();
-
-  Handle<SharedFunctionInfo> shared(
-      SharedFunctionInfo::cast(New(map, AllocationType::kOld)), isolate());
-  int unique_id = -1;
-#if V8_SFI_HAS_UNIQUE_ID
-  unique_id = isolate()->GetNextUniqueSharedFunctionInfoId();
-#endif  // V8_SFI_HAS_UNIQUE_ID
-
-  shared->Init(ReadOnlyRoots(isolate()), unique_id);
-
-#ifdef VERIFY_HEAP
-  shared->SharedFunctionInfoVerify(isolate());
-#endif  // VERIFY_HEAP
-  return shared;
-}
-
 namespace {
 inline int NumberToStringCacheHash(Handle<FixedArray> cache, Smi number) {
   int mask = (cache->length() >> 1) - 1;
@@ -3478,14 +2996,6 @@ Handle<String> Factory::SizeToString(size_t value, bool check_cache) {
   return result;
 }
 
-Handle<ClassPositions> Factory::NewClassPositions(int start, int end) {
-  Handle<ClassPositions> class_positions = Handle<ClassPositions>::cast(
-      NewStruct(CLASS_POSITIONS_TYPE, AllocationType::kOld));
-  class_positions->set_start(start);
-  class_positions->set_end(end);
-  return class_positions;
-}
-
 Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
   DCHECK(!shared->HasDebugInfo());
   Heap* heap = isolate()->heap();
@@ -3509,22 +3019,6 @@ Handle<DebugInfo> Factory::NewDebugInfo(Handle<SharedFunctionInfo> shared) {
   return debug_info;
 }
 
-Handle<CoverageInfo> Factory::NewCoverageInfo(
-    const ZoneVector<SourceRange>& slots) {
-  const int slot_count = static_cast<int>(slots.size());
-
-  const int length = CoverageInfo::FixedArrayLengthForSlotCount(slot_count);
-  Handle<CoverageInfo> info =
-      Handle<CoverageInfo>::cast(NewUninitializedFixedArray(length));
-
-  for (int i = 0; i < slot_count; i++) {
-    SourceRange range = slots[i];
-    info->InitializeSlot(i, range.start, range.end);
-  }
-
-  return info;
-}
-
 Handle<BreakPointInfo> Factory::NewBreakPointInfo(int source_position) {
   Handle<BreakPointInfo> new_break_point_info = Handle<BreakPointInfo>::cast(
       NewStruct(BREAK_POINT_INFO_TYPE, AllocationType::kOld));
@@ -3807,10 +3301,6 @@ Handle<Object> Factory::GlobalConstantFor(Handle<Name> name) {
   return Handle<Object>::null();
 }
 
-Handle<Object> Factory::ToBoolean(bool value) {
-  return value ? true_value() : false_value();
-}
-
 Handle<String> Factory::ToPrimitiveHintString(ToPrimitiveHint hint) {
   switch (hint) {
     case ToPrimitiveHint::kDefault:
@@ -4061,6 +3551,8 @@ bool Factory::EmptyStringRootIsInitialized() {
 NewFunctionArgs NewFunctionArgs::ForWasm(
     Handle<String> name,
     Handle<WasmExportedFunctionData> exported_function_data, Handle<Map> map) {
+  DCHECK(name->IsFlat());
+
   NewFunctionArgs args;
   args.name_ = name;
   args.maybe_map_ = map;
@@ -4075,6 +3567,8 @@ NewFunctionArgs NewFunctionArgs::ForWasm(
 NewFunctionArgs NewFunctionArgs::ForWasm(
     Handle<String> name, Handle<WasmJSFunctionData> js_function_data,
     Handle<Map> map) {
+  DCHECK(name->IsFlat());
+
   NewFunctionArgs args;
   args.name_ = name;
   args.maybe_map_ = map;
@@ -4089,6 +3583,7 @@ NewFunctionArgs NewFunctionArgs::ForWasm(
 NewFunctionArgs NewFunctionArgs::ForBuiltin(Handle<String> name,
                                             Handle<Map> map, int builtin_id) {
   DCHECK(Builtins::IsBuiltinId(builtin_id));
+  DCHECK(name->IsFlat());
 
   NewFunctionArgs args;
   args.name_ = name;
@@ -4105,6 +3600,8 @@ NewFunctionArgs NewFunctionArgs::ForBuiltin(Handle<String> name,
 // static
 NewFunctionArgs NewFunctionArgs::ForFunctionWithoutCode(
     Handle<String> name, Handle<Map> map, LanguageMode language_mode) {
+  DCHECK(name->IsFlat());
+
   NewFunctionArgs args;
   args.name_ = name;
   args.maybe_map_ = map;
@@ -4123,6 +3620,7 @@ NewFunctionArgs NewFunctionArgs::ForBuiltinWithPrototype(
     int instance_size, int inobject_properties, int builtin_id,
     MutableMode prototype_mutability) {
   DCHECK(Builtins::IsBuiltinId(builtin_id));
+  DCHECK(name->IsFlat());
 
   NewFunctionArgs args;
   args.name_ = name;
@@ -4145,6 +3643,7 @@ NewFunctionArgs NewFunctionArgs::ForBuiltinWithPrototype(
 NewFunctionArgs NewFunctionArgs::ForBuiltinWithoutPrototype(
     Handle<String> name, int builtin_id, LanguageMode language_mode) {
   DCHECK(Builtins::IsBuiltinId(builtin_id));
+  DCHECK(name->IsFlat());
 
   NewFunctionArgs args;
   args.name_ = name;
diff --git a/deps/v8/src/heap/factory.h b/deps/v8/src/heap/factory.h
index 877e2f8972..81041f7f40 100644
--- a/deps/v8/src/heap/factory.h
+++ b/deps/v8/src/heap/factory.h
@@ -16,7 +16,6 @@
 #include "src/heap/heap.h"
 #include "src/objects/code.h"
 #include "src/objects/dictionary.h"
-#include "src/objects/function-kind.h"
 #include "src/objects/js-array.h"
 #include "src/objects/js-regexp.h"
 #include "src/objects/string.h"
@@ -55,26 +54,19 @@ class JSWeakMap;
 class LoadHandler;
 class NativeContext;
 class NewFunctionArgs;
-class PreparseData;
 class PromiseResolveThenableJobTask;
 class RegExpMatchInfo;
 class ScriptContextTable;
 class SourceTextModule;
-class SourceTextModuleInfo;
 class StackFrameInfo;
 class StackTraceFrame;
 class StoreHandler;
 class SyntheticModule;
 class TemplateObjectDescription;
-class UncompiledDataWithoutPreparseData;
-class UncompiledDataWithPreparseData;
 class WasmCapiFunctionData;
 class WasmExportedFunctionData;
 class WasmJSFunctionData;
 class WeakCell;
-struct SourceRange;
-template <typename T>
-class ZoneVector;
 enum class SharedFlag : uint8_t;
 enum class InitializedFlag : uint8_t;
 
@@ -106,24 +98,18 @@ enum FunctionMode {
       kWithReadonlyPrototypeBit | kWithNameBit,
 };
 
-class Factory;
-
-template <>
-struct FactoryTraits<Factory> {
-  template <typename T>
-  using HandleType = Handle<T>;
-  template <typename T>
-  using MaybeHandleType = v8::internal::MaybeHandle<T>;
-};
-
 // Interface for handle based allocation.
 class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
  public:
   inline ReadOnlyRoots read_only_roots();
+
   template <typename T>
   Handle<T> MakeHandle(T obj) {
     return handle(obj, isolate());
   }
+
+#include "torque-generated/factory-tq.inc"
+
   Handle<Oddball> NewOddball(Handle<Map> map, const char* to_string,
                              Handle<Object> to_number, const char* type_of,
                              byte kind);
@@ -131,29 +117,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   // Marks self references within code generation.
   Handle<Oddball> NewSelfReferenceMarker();
 
-  // Allocates a fixed array-like object with given map and initialized with
-  // undefined values.
-  template <typename T = FixedArray>
-  Handle<T> NewFixedArrayWithMap(
-      RootIndex map_root_index, int length,
-      AllocationType allocation = AllocationType::kYoung);
-
-  // Allocates a weak fixed array-like object with given map and initialized
-  // with undefined values.
-  template <typename T = WeakFixedArray>
-  Handle<T> NewWeakFixedArrayWithMap(
-      RootIndex map_root_index, int length,
-      AllocationType allocation = AllocationType::kYoung);
-
-  // Allocates a fixed array initialized with undefined values.
-  Handle<FixedArray> NewFixedArray(
-      int length, AllocationType allocation = AllocationType::kYoung);
-
-  // Allocates a fixed array which may contain in-place weak references. The
-  // array is initialized with undefined values
-  Handle<WeakFixedArray> NewWeakFixedArray(
-      int length, AllocationType allocation = AllocationType::kYoung);
-
   // Allocates a property array initialized with undefined values.
   Handle<PropertyArray> NewPropertyArray(int length);
   // Tries allocating a fixed array initialized with undefined values.
@@ -165,10 +128,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   MaybeHandle<FixedArray> TryNewFixedArray(
       int length, AllocationType allocation = AllocationType::kYoung);
 
-  // Allocate a new fixed array with non-existing entries (the hole).
-  Handle<FixedArray> NewFixedArrayWithHoles(
-      int length, AllocationType allocation = AllocationType::kYoung);
-
   // Allocates an uninitialized fixed array. It must be filled by the caller.
   Handle<FixedArray> NewUninitializedFixedArray(int length);
 
@@ -185,24 +144,9 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   // Allocates a clean embedder data array with given capacity.
   Handle<EmbedderDataArray> NewEmbedderDataArray(int length);
 
-  // Allocates a fixed array for name-value pairs of boilerplate properties and
-  // calculates the number of properties we need to store in the backing store.
-  Handle<ObjectBoilerplateDescription> NewObjectBoilerplateDescription(
-      int boilerplate, int all_properties, int index_keys, bool has_seen_proto);
-
-  // Allocate a new uninitialized fixed double array.
-  // The function returns a pre-allocated empty fixed array for length = 0,
-  // so the return type must be the general fixed array class.
-  Handle<FixedArrayBase> NewFixedDoubleArray(int length);
-
   // Allocate a new fixed double array with hole values.
   Handle<FixedArrayBase> NewFixedDoubleArrayWithHoles(int size);
 
-  // Allocates a FeedbackMedata object and zeroes the data section.
-  Handle<FeedbackMetadata> NewFeedbackMetadata(
-      int slot_count, int feedback_cell_count,
-      AllocationType allocation = AllocationType::kOld);
-
   Handle<FrameArray> NewFrameArray(int number_of_frames);
 
   Handle<OrderedHashSet> NewOrderedHashSet();
@@ -230,17 +174,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   Handle<Tuple2> NewTuple2(Handle<Object> value1, Handle<Object> value2,
                            AllocationType allocation);
 
-  // Create a new ArrayBoilerplateDescription struct.
-  Handle<ArrayBoilerplateDescription> NewArrayBoilerplateDescription(
-      ElementsKind elements_kind, Handle<FixedArrayBase> constant_values);
-
-  // Create a new TemplateObjectDescription struct.
-  Handle<TemplateObjectDescription> NewTemplateObjectDescription(
-      Handle<FixedArray> raw_strings, Handle<FixedArray> cooked_strings);
-
-  // Create a pre-tenured empty AccessorPair.
-  Handle<AccessorPair> NewAccessorPair();
-
   // Create a new PropertyDescriptorObject struct.
   Handle<PropertyDescriptorObject> NewPropertyDescriptorObject();
 
@@ -417,16 +350,11 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   Handle<Context> NewBuiltinContext(Handle<NativeContext> native_context,
                                     int length);
 
-  Handle<Struct> NewStruct(InstanceType type,
-                           AllocationType allocation = AllocationType::kYoung);
-
   Handle<AliasedArgumentsEntry> NewAliasedArgumentsEntry(
       int aliased_context_slot);
 
   Handle<AccessorInfo> NewAccessorInfo();
 
-  Handle<Script> NewScript(Handle<String> source);
-  Handle<Script> NewScriptWithId(Handle<String> source, int script_id);
   Handle<Script> CloneScript(Handle<Script> script);
 
   Handle<BreakPointInfo> NewBreakPointInfo(int source_position);
@@ -448,13 +376,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   // Foreign objects are pretenured when allocated by the bootstrapper.
   Handle<Foreign> NewForeign(Address addr);
 
-  Handle<ByteArray> NewByteArray(
-      int length, AllocationType allocation = AllocationType::kYoung);
-
-  Handle<BytecodeArray> NewBytecodeArray(int length, const byte* raw_bytecodes,
-                                         int frame_size, int parameter_count,
-                                         Handle<FixedArray> constant_pool);
-
   Handle<Cell> NewCell(Handle<Object> value);
 
   Handle<PropertyCell> NewPropertyCell(
@@ -464,8 +385,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   Handle<FeedbackCell> NewOneClosureCell(Handle<HeapObject> value);
   Handle<FeedbackCell> NewManyClosuresCell(Handle<HeapObject> value);
 
-  Handle<DescriptorArray> NewDescriptorArray(int number_of_entries,
-                                             int slack = 0);
   Handle<TransitionArray> NewTransitionArray(int number_of_transitions,
                                              int slack = 0);
 
@@ -534,36 +453,10 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
 
   Handle<FixedDoubleArray> CopyFixedDoubleArray(Handle<FixedDoubleArray> array);
 
-  // Numbers (e.g. literals) are pretenured by the parser.
-  // The return value may be a smi or a heap number.
-  template <AllocationType allocation = AllocationType::kYoung>
-  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<Object> NewNumber(double value);
-  Handle<Object> NewNumberFromInt(int32_t value);
-  Handle<Object> NewNumberFromUint(uint32_t value);
-  inline Handle<Object> NewNumberFromSize(size_t value);
-  inline Handle<Object> NewNumberFromInt64(int64_t value);
-  template <AllocationType allocation = AllocationType::kYoung>
-  inline Handle<HeapNumber> NewHeapNumber(double value);
-  template <AllocationType allocation = AllocationType::kYoung>
-  inline Handle<HeapNumber> NewHeapNumberFromBits(uint64_t bits);
-
-  // Creates heap number object with not yet set value field.
-  template <AllocationType allocation = AllocationType::kYoung>
-  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-  Handle<HeapNumber> NewHeapNumber();
-
   // Creates a new HeapNumber in read-only space if possible otherwise old
   // space.
   Handle<HeapNumber> NewHeapNumberForCodeAssembler(double value);
 
-  inline Handle<HeapNumber> NewHeapNumberWithHoleNaN();
-
-  // Allocates a new BigInt with {length} digits. Only to be used by
-  // MutableBigInt::New*.
-  Handle<FreshlyAllocatedBigInt> NewBigInt(
-      int length, AllocationType allocation = AllocationType::kYoung);
-
   Handle<JSObject> NewArgumentsObject(Handle<JSFunction> callee, int length);
 
   // Allocates and initializes a new JavaScript object based on a
@@ -736,23 +629,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       Handle<Map> map, Handle<SharedFunctionInfo> info, Handle<Context> context,
       AllocationType allocation = AllocationType::kOld);
 
-  // Create a serialized scope info.
-  Handle<ScopeInfo> NewScopeInfo(int length,
-                                 AllocationType type = AllocationType::kOld);
-
-  Handle<SourceTextModuleInfo> NewSourceTextModuleInfo();
-
-  Handle<PreparseData> NewPreparseData(int data_length, int children_length);
-
-  Handle<UncompiledDataWithoutPreparseData>
-  NewUncompiledDataWithoutPreparseData(Handle<String> inferred_name,
-                                       int32_t start_position,
-                                       int32_t end_position);
-
-  Handle<UncompiledDataWithPreparseData> NewUncompiledDataWithPreparseData(
-      Handle<String> inferred_name, int32_t start_position,
-      int32_t end_position, Handle<PreparseData>);
-
   // Create an External object for V8's external API.
   Handle<JSObject> NewExternal(void* value);
 
@@ -826,9 +702,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       MaybeHandle<String> name, int builtin_index,
       FunctionKind kind = kNormalFunction);
 
-  Handle<SharedFunctionInfo> NewSharedFunctionInfoForLiteral(
-      FunctionLiteral* literal, Handle<Script> script, bool is_toplevel);
-
   static bool IsFunctionModeWithPrototype(FunctionMode function_mode) {
     return (function_mode & kWithPrototypeBits) != 0;
   }
@@ -859,11 +732,8 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       int end_position, Handle<SharedFunctionInfo> shared_info,
       int bytecode_offset, Handle<Script> script, Handle<Object> stack_frames);
 
-  Handle<ClassPositions> NewClassPositions(int start, int end);
   Handle<DebugInfo> NewDebugInfo(Handle<SharedFunctionInfo> shared);
 
-  Handle<CoverageInfo> NewCoverageInfo(const ZoneVector<SourceRange>& slots);
-
   // Return a map for given number of properties using the map cache in the
   // native context.
   Handle<Map> ObjectLiteralMapFromCache(Handle<NativeContext> native_context,
@@ -892,9 +762,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   // Returns a null handle when the given name is unknown.
   Handle<Object> GlobalConstantFor(Handle<Name> name);
 
-  // Converts the given boolean condition to JavaScript boolean value.
-  Handle<Object> ToBoolean(bool value);
-
   // Converts the given ToPrimitive hint to it's string representation.
   Handle<String> ToPrimitiveHintString(ToPrimitiveHint hint);
 
@@ -1003,12 +870,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   // Customization points for FactoryBase
   HeapObject AllocateRaw(int size, AllocationType allocation,
                          AllocationAlignment alignment = kWordAligned);
-  template <typename T>
-  inline MaybeHandle<T> Throw(Handle<Object> exception);
-  [[noreturn]] void FatalProcessOutOfHeapMemory(const char* location);
-  bool CanAllocateInReadOnlySpace();
-  bool EmptyStringRootIsInitialized();
-  // ------
 
   Isolate* isolate() {
     // Downcast to the privately inherited sub-class using c-style casts to
@@ -1017,6 +878,13 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
     // NOLINTNEXTLINE (google-readability-casting)
     return (Isolate*)this;  // NOLINT(readability/casting)
   }
+  bool CanAllocateInReadOnlySpace();
+  bool EmptyStringRootIsInitialized();
+
+  Handle<String> MakeOrFindTwoCharacterString(uint16_t c1, uint16_t c2);
+
+  void AddToScriptList(Handle<Script> shared);
+  // ------
 
   HeapObject AllocateRawWithAllocationSite(
       Handle<Map> map, AllocationType allocation,
@@ -1026,14 +894,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       Handle<Map> map, Handle<FixedArrayBase> elements,
       Handle<JSArrayBuffer> buffer, size_t byte_offset, size_t byte_length);
 
-  // Allocate memory for an uninitialized array (e.g., a FixedArray or similar).
-  HeapObject AllocateRawArray(int size, AllocationType allocation);
-  HeapObject AllocateRawFixedArray(int length, AllocationType allocation);
-  HeapObject AllocateRawWeakArrayList(int length, AllocationType allocation);
-  Handle<FixedArray> NewFixedArrayWithFiller(RootIndex map_root_index,
-                                             int length, Object filler,
-                                             AllocationType allocation);
-
   // Allocates new context with given map, sets length and initializes the
   // after-header part with uninitialized values and leaves the context header
   // uninitialized.
@@ -1065,8 +925,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
   MaybeHandle<String> NewStringFromTwoByte(const uc16* string, int length,
                                            AllocationType allocation);
 
-  Handle<String> MakeOrFindTwoCharacterString(uint16_t c1, uint16_t c2);
-
   // Attempt to find the number in a small cache.  If we finds it, return
   // the string representation of the number.  Otherwise return undefined.
   Handle<Object> NumberToStringCacheGet(Object number, int hash);
@@ -1089,11 +947,6 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       ElementsKind elements_kind, int capacity,
       ArrayStorageAllocationMode mode = DONT_INITIALIZE_ARRAY_ELEMENTS);
 
-  Handle<SharedFunctionInfo> NewSharedFunctionInfo();
-  Handle<SharedFunctionInfo> NewSharedFunctionInfo(
-      MaybeHandle<String> name, MaybeHandle<HeapObject> maybe_function_data,
-      int maybe_builtin_index, FunctionKind kind = kNormalFunction);
-
   void InitializeAllocationMemento(AllocationMemento memento,
                                    AllocationSite allocation_site);
 
diff --git a/deps/v8/src/heap/finalization-registry-cleanup-task.cc b/deps/v8/src/heap/finalization-registry-cleanup-task.cc
new file mode 100644
index 0000000000..c1868d4862
--- /dev/null
+++ b/deps/v8/src/heap/finalization-registry-cleanup-task.cc
@@ -0,0 +1,77 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/finalization-registry-cleanup-task.h"
+
+#include "src/execution/frames.h"
+#include "src/execution/interrupts-scope.h"
+#include "src/execution/stack-guard.h"
+#include "src/execution/v8threads.h"
+#include "src/heap/heap-inl.h"
+#include "src/objects/js-weak-refs-inl.h"
+#include "src/tracing/trace-event.h"
+
+namespace v8 {
+namespace internal {
+
+FinalizationRegistryCleanupTask::FinalizationRegistryCleanupTask(Heap* heap)
+    : CancelableTask(heap->isolate()), heap_(heap) {}
+
+void FinalizationRegistryCleanupTask::SlowAssertNoActiveJavaScript() {
+#ifdef ENABLE_SLOW_DCHECKS
+  class NoActiveJavaScript : public ThreadVisitor {
+   public:
+    void VisitThread(Isolate* isolate, ThreadLocalTop* top) override {
+      for (StackFrameIterator it(isolate, top); !it.done(); it.Advance()) {
+        DCHECK(!it.frame()->is_java_script());
+      }
+    }
+  };
+  NoActiveJavaScript no_active_js_visitor;
+  Isolate* isolate = heap_->isolate();
+  no_active_js_visitor.VisitThread(isolate, isolate->thread_local_top());
+  isolate->thread_manager()->IterateArchivedThreads(&no_active_js_visitor);
+#endif  // ENABLE_SLOW_DCHECKS
+}
+
+void FinalizationRegistryCleanupTask::RunInternal() {
+  Isolate* isolate = heap_->isolate();
+  DCHECK(!isolate->host_cleanup_finalization_group_callback());
+  SlowAssertNoActiveJavaScript();
+
+  TRACE_EVENT_CALL_STATS_SCOPED(isolate, "v8",
+                                "V8.FinalizationRegistryCleanupTask");
+
+  HandleScope handle_scope(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry;
+  // There could be no dirty FinalizationRegistries. When a context is disposed
+  // by the embedder, its FinalizationRegistries are removed from the dirty
+  // list.
+  if (!heap_->DequeueDirtyJSFinalizationRegistry().ToHandle(
+          &finalization_registry)) {
+    return;
+  }
+  finalization_registry->set_scheduled_for_cleanup(false);
+
+  // Since FinalizationRegistry cleanup callbacks are scheduled by V8, enter the
+  // FinalizationRegistry's context.
+  Handle<Context> context(
+      Context::cast(finalization_registry->native_context()), isolate);
+  Handle<Object> callback(finalization_registry->cleanup(), isolate);
+  v8::Context::Scope context_scope(v8::Utils::ToLocal(context));
+  v8::TryCatch catcher(reinterpret_cast<v8::Isolate*>(isolate));
+  catcher.SetVerbose(true);
+
+  // Exceptions are reported via the message handler. This is ensured by the
+  // verbose TryCatch.
+  InvokeFinalizationRegistryCleanupFromTask(context, finalization_registry,
+                                            callback);
+
+  // Repost if there are remaining dirty FinalizationRegistries.
+  heap_->set_is_finalization_registry_cleanup_task_posted(false);
+  heap_->PostFinalizationRegistryCleanupTaskIfNeeded();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/heap/finalization-registry-cleanup-task.h b/deps/v8/src/heap/finalization-registry-cleanup-task.h
new file mode 100644
index 0000000000..bb25c1abec
--- /dev/null
+++ b/deps/v8/src/heap/finalization-registry-cleanup-task.h
@@ -0,0 +1,36 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_FINALIZATION_REGISTRY_CLEANUP_TASK_H_
+#define V8_HEAP_FINALIZATION_REGISTRY_CLEANUP_TASK_H_
+
+#include "src/objects/js-weak-refs.h"
+#include "src/tasks/cancelable-task.h"
+
+namespace v8 {
+namespace internal {
+
+// The GC schedules a cleanup task when the dirty FinalizationRegistry list is
+// non-empty. The task processes a single FinalizationRegistry and posts another
+// cleanup task if there are remaining dirty FinalizationRegistries on the list.
+class FinalizationRegistryCleanupTask : public CancelableTask {
+ public:
+  explicit FinalizationRegistryCleanupTask(Heap* heap);
+  ~FinalizationRegistryCleanupTask() override = default;
+
+ private:
+  FinalizationRegistryCleanupTask(const FinalizationRegistryCleanupTask&) =
+      delete;
+  void operator=(const FinalizationRegistryCleanupTask&) = delete;
+
+  void RunInternal() override;
+  void SlowAssertNoActiveJavaScript();
+
+  Heap* heap_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_FINALIZATION_REGISTRY_CLEANUP_TASK_H_
diff --git a/deps/v8/src/heap/gc-idle-time-handler.cc b/deps/v8/src/heap/gc-idle-time-handler.cc
index 7b1defb935..ea42812585 100644
--- a/deps/v8/src/heap/gc-idle-time-handler.cc
+++ b/deps/v8/src/heap/gc-idle-time-handler.cc
@@ -12,10 +12,7 @@ namespace v8 {
 namespace internal {
 
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
-const size_t GCIdleTimeHandler::kMaxFinalIncrementalMarkCompactTimeInMs = 1000;
 const double GCIdleTimeHandler::kHighContextDisposalRate = 100;
-const size_t GCIdleTimeHandler::kMinTimeForOverApproximatingWeakClosureInMs = 1;
-
 
 void GCIdleTimeHeapState::Print() {
   PrintF("contexts_disposed=%d ", contexts_disposed);
@@ -39,18 +36,6 @@ size_t GCIdleTimeHandler::EstimateMarkingStepSize(
   return static_cast<size_t>(marking_step_size * kConservativeTimeRatio);
 }
 
-double GCIdleTimeHandler::EstimateFinalIncrementalMarkCompactTime(
-    size_t size_of_objects,
-    double final_incremental_mark_compact_speed_in_bytes_per_ms) {
-  if (final_incremental_mark_compact_speed_in_bytes_per_ms == 0) {
-    final_incremental_mark_compact_speed_in_bytes_per_ms =
-        kInitialConservativeFinalIncrementalMarkCompactSpeed;
-  }
-  double result =
-      size_of_objects / final_incremental_mark_compact_speed_in_bytes_per_ms;
-  return Min<double>(result, kMaxFinalIncrementalMarkCompactTimeInMs);
-}
-
 bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
     int contexts_disposed, double contexts_disposal_rate,
     size_t size_of_objects) {
@@ -59,34 +44,13 @@ bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
          size_of_objects <= kMaxHeapSizeForContextDisposalMarkCompact;
 }
 
-bool GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
-    double idle_time_in_ms, size_t size_of_objects,
-    double final_incremental_mark_compact_speed_in_bytes_per_ms) {
-  return idle_time_in_ms >=
-         EstimateFinalIncrementalMarkCompactTime(
-             size_of_objects,
-             final_incremental_mark_compact_speed_in_bytes_per_ms);
-}
-
-bool GCIdleTimeHandler::ShouldDoOverApproximateWeakClosure(
-    double idle_time_in_ms) {
-  // TODO(jochen): Estimate the time it will take to build the object groups.
-  return idle_time_in_ms >= kMinTimeForOverApproximatingWeakClosureInMs;
-}
-
-
 // The following logic is implemented by the controller:
 // (1) If we don't have any idle time, do nothing, unless a context was
 // disposed, incremental marking is stopped, and the heap is small. Then do
 // a full GC.
 // (2) If the context disposal rate is high and we cannot perform a full GC,
 // we do nothing until the context disposal rate becomes lower.
-// (3) If the new space is almost full and we can afford a scavenge or if the
-// next scavenge will very likely take long, then a scavenge is performed.
-// (4) If sweeping is in progress and we received a large enough idle time
-// request, we finalize sweeping here.
-// (5) If incremental marking is in progress, we perform a marking step. Note,
-// that this currently may trigger a full garbage collection.
+// (3) If incremental marking is in progress, we perform a marking step.
 GCIdleTimeAction GCIdleTimeHandler::Compute(double idle_time_in_ms,
                                             GCIdleTimeHeapState heap_state) {
   if (static_cast<int>(idle_time_in_ms) <= 0) {
diff --git a/deps/v8/src/heap/gc-idle-time-handler.h b/deps/v8/src/heap/gc-idle-time-handler.h
index a7ce5dafc7..f14330ea8a 100644
--- a/deps/v8/src/heap/gc-idle-time-handler.h
+++ b/deps/v8/src/heap/gc-idle-time-handler.h
@@ -42,42 +42,15 @@ class V8_EXPORT_PRIVATE GCIdleTimeHandler {
   // idle_time_in_ms. Hence, we conservatively prune our workload estimate.
   static const double kConservativeTimeRatio;
 
-  // If we haven't recorded any mark-compact events yet, we use
-  // conservative lower bound for the mark-compact speed.
-  static const size_t kInitialConservativeMarkCompactSpeed = 2 * MB;
-
-  // If we haven't recorded any final incremental mark-compact events yet, we
-  // use conservative lower bound for the mark-compact speed.
-  static const size_t kInitialConservativeFinalIncrementalMarkCompactSpeed =
-      2 * MB;
-
-  // Maximum final incremental mark-compact time returned by
-  // EstimateFinalIncrementalMarkCompactTime.
-  static const size_t kMaxFinalIncrementalMarkCompactTimeInMs;
-
   // This is the maximum scheduled idle time. Note that it can be more than
   // 16.66 ms when there is currently no rendering going on.
   static const size_t kMaxScheduledIdleTime = 50;
 
-  // The maximum idle time when frames are rendered is 16.66ms.
-  static const size_t kMaxFrameRenderingIdleTime = 17;
-
-  static const int kMinBackgroundIdleTime = 900;
-
-  // An allocation throughput below kLowAllocationThroughput bytes/ms is
-  // considered low
-  static const size_t kLowAllocationThroughput = 1000;
-
   static const size_t kMaxHeapSizeForContextDisposalMarkCompact = 100 * MB;
 
   // If contexts are disposed at a higher rate a full gc is triggered.
   static const double kHighContextDisposalRate;
 
-  // Incremental marking step time.
-  static const size_t kIncrementalMarkingStepTimeInMs = 1;
-
-  static const size_t kMinTimeForOverApproximatingWeakClosureInMs;
-
   GCIdleTimeHandler() = default;
 
   GCIdleTimeAction Compute(double idle_time_in_ms,
@@ -95,12 +68,6 @@ class V8_EXPORT_PRIVATE GCIdleTimeHandler {
                                                  double contexts_disposal_rate,
                                                  size_t size_of_objects);
 
-  static bool ShouldDoFinalIncrementalMarkCompact(
-      double idle_time_in_ms, size_t size_of_objects,
-      double final_incremental_mark_compact_speed_in_bytes_per_ms);
-
-  static bool ShouldDoOverApproximateWeakClosure(double idle_time_in_ms);
-
  private:
   DISALLOW_COPY_AND_ASSIGN(GCIdleTimeHandler);
 };
diff --git a/deps/v8/src/heap/gc-tracer.cc b/deps/v8/src/heap/gc-tracer.cc
index b165b69882..f023bd7c74 100644
--- a/deps/v8/src/heap/gc-tracer.cc
+++ b/deps/v8/src/heap/gc-tracer.cc
@@ -518,11 +518,12 @@ void GCTracer::Print() const {
   Output(
       "[%d:%p] "
       "%8.0f ms: "
-      "%s %.1f (%.1f) -> %.1f (%.1f) MB, "
+      "%s%s %.1f (%.1f) -> %.1f (%.1f) MB, "
       "%.1f / %.1f ms %s (average mu = %.3f, current mu = %.3f) %s %s\n",
       base::OS::GetCurrentProcessId(),
       reinterpret_cast<void*>(heap_->isolate()),
       heap_->isolate()->time_millis_since_init(), current_.TypeName(false),
+      current_.reduce_memory ? " (reduce)" : "",
       static_cast<double>(current_.start_object_size) / MB,
       static_cast<double>(current_.start_memory_size) / MB,
       static_cast<double>(current_.end_object_size) / MB,
@@ -931,6 +932,19 @@ void GCTracer::RecordIncrementalMarkingSpeed(size_t bytes, double duration) {
   }
 }
 
+void GCTracer::RecordTimeToIncrementalMarkingTask(double time_to_task) {
+  if (average_time_to_incremental_marking_task_ == 0.0) {
+    average_time_to_incremental_marking_task_ = time_to_task;
+  } else {
+    average_time_to_incremental_marking_task_ =
+        (average_time_to_incremental_marking_task_ + time_to_task) / 2;
+  }
+}
+
+double GCTracer::AverageTimeToIncrementalMarkingTask() const {
+  return average_time_to_incremental_marking_task_;
+}
+
 void GCTracer::RecordEmbedderSpeed(size_t bytes, double duration) {
   if (duration == 0 || bytes == 0) return;
   double current_speed = bytes / duration;
diff --git a/deps/v8/src/heap/gc-tracer.h b/deps/v8/src/heap/gc-tracer.h
index 454bb9ff17..6ff6e18a59 100644
--- a/deps/v8/src/heap/gc-tracer.h
+++ b/deps/v8/src/heap/gc-tracer.h
@@ -353,6 +353,11 @@ class V8_EXPORT_PRIVATE GCTracer {
 
   void RecordEmbedderSpeed(size_t bytes, double duration);
 
+  // Returns the average time between scheduling and invocation of an
+  // incremental marking task.
+  double AverageTimeToIncrementalMarkingTask() const;
+  void RecordTimeToIncrementalMarkingTask(double time_to_task);
+
   WorkerThreadRuntimeCallStats* worker_thread_runtime_call_stats();
 
  private:
@@ -446,6 +451,8 @@ class V8_EXPORT_PRIVATE GCTracer {
 
   double recorded_incremental_marking_speed_;
 
+  double average_time_to_incremental_marking_task_ = 0.0;
+
   double recorded_embedder_speed_ = 0.0;
 
   // Incremental scopes carry more information than just the duration. The infos
diff --git a/deps/v8/src/heap/heap-inl.h b/deps/v8/src/heap/heap-inl.h
index 0e5230f1e0..e618b91058 100644
--- a/deps/v8/src/heap/heap-inl.h
+++ b/deps/v8/src/heap/heap-inl.h
@@ -10,6 +10,7 @@
 // Clients of this interface shouldn't depend on lots of heap internals.
 // Do not include anything from src/heap other than src/heap/heap.h and its
 // write barrier here!
+#include "src/base/atomicops.h"
 #include "src/heap/heap-write-barrier.h"
 #include "src/heap/heap.h"
 #include "src/heap/third-party/heap-api.h"
@@ -65,7 +66,14 @@ int64_t Heap::external_memory() {
 }
 
 void Heap::update_external_memory(int64_t delta) {
-  isolate()->isolate_data()->external_memory_ += delta;
+  const int64_t amount = isolate()->isolate_data()->external_memory_ + delta;
+  isolate()->isolate_data()->external_memory_ = amount;
+  if (amount <
+      isolate()->isolate_data()->external_memory_low_since_mark_compact_) {
+    isolate()->isolate_data()->external_memory_low_since_mark_compact_ = amount;
+    isolate()->isolate_data()->external_memory_limit_ =
+        amount + kExternalAllocationSoftLimit;
+  }
 }
 
 void Heap::update_external_memory_concurrently_freed(uintptr_t freed) {
@@ -73,8 +81,8 @@ void Heap::update_external_memory_concurrently_freed(uintptr_t freed) {
 }
 
 void Heap::account_external_memory_concurrently_freed() {
-  isolate()->isolate_data()->external_memory_ -=
-      external_memory_concurrently_freed_;
+  update_external_memory(
+      -static_cast<int64_t>(external_memory_concurrently_freed_));
   external_memory_concurrently_freed_ = 0;
 }
 
@@ -155,6 +163,14 @@ size_t Heap::NewSpaceAllocationCounter() {
   return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC();
 }
 
+inline const base::AddressRegion& Heap::code_range() {
+#ifdef V8_ENABLE_THIRD_PARTY_HEAP
+  return tp_heap_->GetCodeRange();
+#else
+  return memory_allocator_->code_range();
+#endif
+}
+
 AllocationResult Heap::AllocateRaw(int size_in_bytes, AllocationType type,
                                    AllocationOrigin origin,
                                    AllocationAlignment alignment) {
@@ -248,13 +264,13 @@ template <Heap::AllocationRetryMode mode>
 HeapObject Heap::AllocateRawWith(int size, AllocationType allocation,
                                  AllocationOrigin origin,
                                  AllocationAlignment alignment) {
+  DCHECK(AllowHandleAllocation::IsAllowed());
+  DCHECK(AllowHeapAllocation::IsAllowed());
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
     AllocationResult result = AllocateRaw(size, allocation, origin, alignment);
     DCHECK(!result.IsRetry());
     return result.ToObjectChecked();
   }
-  DCHECK(AllowHandleAllocation::IsAllowed());
-  DCHECK(AllowHeapAllocation::IsAllowed());
   DCHECK_EQ(gc_state_, NOT_IN_GC);
   Heap* heap = isolate()->heap();
   Address* top = heap->NewSpaceAllocationTopAddress();
@@ -286,7 +302,7 @@ HeapObject Heap::AllocateRawWith(int size, AllocationType allocation,
 Address Heap::DeserializerAllocate(AllocationType type, int size_in_bytes) {
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
     AllocationResult allocation = tp_heap_->Allocate(
-        size_in_bytes, type, AllocationAlignment::kWordAligned);
+        size_in_bytes, type, AllocationAlignment::kDoubleAligned);
     return allocation.ToObjectChecked().ptr();
   } else {
     UNIMPLEMENTED();  // unimplemented
@@ -560,11 +576,27 @@ Oddball Heap::ToBoolean(bool condition) {
 }
 
 int Heap::NextScriptId() {
-  int last_id = last_script_id().value();
-  if (last_id == Smi::kMaxValue) last_id = v8::UnboundScript::kNoScriptId;
-  last_id++;
-  set_last_script_id(Smi::FromInt(last_id));
-  return last_id;
+  FullObjectSlot last_script_id_slot(&roots_table()[RootIndex::kLastScriptId]);
+  Smi last_id = Smi::cast(last_script_id_slot.Relaxed_Load());
+  Smi new_id, last_id_before_cas;
+  do {
+    if (last_id.value() == Smi::kMaxValue) {
+      STATIC_ASSERT(v8::UnboundScript::kNoScriptId == 0);
+      new_id = Smi::FromInt(1);
+    } else {
+      new_id = Smi::FromInt(last_id.value() + 1);
+    }
+
+    // CAS returns the old value on success, and the current value in the slot
+    // on failure. Therefore, we want to break if the returned value matches the
+    // old value (last_id), and keep looping (with the new last_id value) if it
+    // doesn't.
+    last_id_before_cas = last_id;
+    last_id =
+        Smi::cast(last_script_id_slot.Relaxed_CompareAndSwap(last_id, new_id));
+  } while (last_id != last_id_before_cas);
+
+  return new_id.value();
 }
 
 int Heap::NextDebuggingId() {
@@ -608,17 +640,21 @@ void Heap::DecrementExternalBackingStoreBytes(ExternalBackingStoreType type,
   base::CheckedDecrement(&backing_store_bytes_, amount);
 }
 
+bool Heap::HasDirtyJSFinalizationRegistries() {
+  return !dirty_js_finalization_registries_list().IsUndefined(isolate());
+}
+
 AlwaysAllocateScope::AlwaysAllocateScope(Heap* heap) : heap_(heap) {
   heap_->always_allocate_scope_count_++;
 }
 
-AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
-    : AlwaysAllocateScope(isolate->heap()) {}
-
 AlwaysAllocateScope::~AlwaysAllocateScope() {
   heap_->always_allocate_scope_count_--;
 }
 
+AlwaysAllocateScopeForTesting::AlwaysAllocateScopeForTesting(Heap* heap)
+    : scope_(heap) {}
+
 CodeSpaceMemoryModificationScope::CodeSpaceMemoryModificationScope(Heap* heap)
     : heap_(heap) {
   if (heap_->write_protect_code_memory()) {
diff --git a/deps/v8/src/heap/heap-write-barrier-inl.h b/deps/v8/src/heap/heap-write-barrier-inl.h
index 7b1438e6a3..8fec301fe7 100644
--- a/deps/v8/src/heap/heap-write-barrier-inl.h
+++ b/deps/v8/src/heap/heap-write-barrier-inl.h
@@ -61,6 +61,7 @@ struct MemoryChunk {
 
   V8_INLINE static heap_internals::MemoryChunk* FromHeapObject(
       HeapObject object) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<MemoryChunk*>(object.ptr() & ~kPageAlignmentMask);
   }
 
diff --git a/deps/v8/src/heap/heap.cc b/deps/v8/src/heap/heap.cc
index 28ff2e970d..518bbcf162 100644
--- a/deps/v8/src/heap/heap.cc
+++ b/deps/v8/src/heap/heap.cc
@@ -33,12 +33,14 @@
 #include "src/heap/combined-heap.h"
 #include "src/heap/concurrent-marking.h"
 #include "src/heap/embedder-tracing.h"
+#include "src/heap/finalization-registry-cleanup-task.h"
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/heap/heap-controller.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/heap/incremental-marking-inl.h"
 #include "src/heap/incremental-marking.h"
+#include "src/heap/local-heap.h"
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/mark-compact.h"
 #include "src/heap/memory-measurement.h"
@@ -48,6 +50,7 @@
 #include "src/heap/objects-visiting.h"
 #include "src/heap/read-only-heap.h"
 #include "src/heap/remembered-set.h"
+#include "src/heap/safepoint.h"
 #include "src/heap/scavenge-job.h"
 #include "src/heap/scavenger-inl.h"
 #include "src/heap/stress-marking-observer.h"
@@ -182,13 +185,13 @@ struct Heap::StrongRootsList {
   StrongRootsList* next;
 };
 
-class IdleScavengeObserver : public AllocationObserver {
+class ScavengeTaskObserver : public AllocationObserver {
  public:
-  IdleScavengeObserver(Heap* heap, intptr_t step_size)
+  ScavengeTaskObserver(Heap* heap, intptr_t step_size)
       : AllocationObserver(step_size), heap_(heap) {}
 
   void Step(int bytes_allocated, Address, size_t) override {
-    heap_->ScheduleIdleScavengeIfNeeded(bytes_allocated);
+    heap_->ScheduleScavengeTaskIfNeeded();
   }
 
  private:
@@ -199,12 +202,15 @@ Heap::Heap()
     : isolate_(isolate()),
       memory_pressure_level_(MemoryPressureLevel::kNone),
       global_pretenuring_feedback_(kInitialFeedbackCapacity),
+      safepoint_(new Safepoint(this)),
       external_string_table_(this) {
   // Ensure old_generation_size_ is a multiple of kPageSize.
   DCHECK_EQ(0, max_old_generation_size_ & (Page::kPageSize - 1));
 
   set_native_contexts_list(Smi::zero());
   set_allocation_sites_list(Smi::zero());
+  set_dirty_js_finalization_registries_list(Smi::zero());
+  set_dirty_js_finalization_registries_list_tail(Smi::zero());
   // Put a dummy entry in the remembered pages so we can find the list the
   // minidump even if there are no real unmapped pages.
   RememberUnmappedPage(kNullAddress, false);
@@ -410,7 +416,6 @@ bool Heap::HasBeenSetUp() {
   return new_space_ != nullptr;
 }
 
-
 GarbageCollector Heap::SelectGarbageCollector(AllocationSpace space,
                                               const char** reason) {
   // Is global GC requested?
@@ -817,12 +822,6 @@ void Heap::GarbageCollectionPrologue() {
   {
     AllowHeapAllocation for_the_first_part_of_prologue;
     gc_count_++;
-
-#ifdef VERIFY_HEAP
-    if (FLAG_verify_heap) {
-      Verify();
-    }
-#endif
   }
 
   // Reset GC statistics.
@@ -865,6 +864,14 @@ size_t Heap::SizeOfObjects() {
   return total;
 }
 
+size_t Heap::TotalGlobalHandlesSize() {
+  return isolate_->global_handles()->TotalSize();
+}
+
+size_t Heap::UsedGlobalHandlesSize() {
+  return isolate_->global_handles()->UsedSize();
+}
+
 // static
 const char* Heap::GetSpaceName(AllocationSpace space) {
   switch (space) {
@@ -1090,10 +1097,10 @@ void Heap::DeoptMarkedAllocationSites() {
   // TODO(hpayer): If iterating over the allocation sites list becomes a
   // performance issue, use a cache data structure in heap instead.
 
-  ForeachAllocationSite(allocation_sites_list(), [this](AllocationSite site) {
+  ForeachAllocationSite(allocation_sites_list(), [](AllocationSite site) {
     if (site.deopt_dependent_code()) {
       site.dependent_code().MarkCodeForDeoptimization(
-          isolate_, DependentCode::kAllocationSiteTenuringChangedGroup);
+          DependentCode::kAllocationSiteTenuringChangedGroup);
       site.set_deopt_dependent_code(false);
     }
   });
@@ -1108,12 +1115,6 @@ void Heap::GarbageCollectionEpilogue() {
     ZapFromSpace();
   }
 
-#ifdef VERIFY_HEAP
-  if (FLAG_verify_heap) {
-    Verify();
-  }
-#endif
-
   AllowHeapAllocation for_the_rest_of_the_epilogue;
 
 #ifdef DEBUG
@@ -1197,18 +1198,13 @@ void Heap::GarbageCollectionEpilogue() {
     ReduceNewSpaceSize();
   }
 
-  if (FLAG_harmony_weak_refs) {
+  if (FLAG_harmony_weak_refs &&
+      isolate()->host_cleanup_finalization_group_callback()) {
     HandleScope handle_scope(isolate());
-    while (!isolate()->heap()->dirty_js_finalization_groups().IsUndefined(
-        isolate())) {
-      Handle<JSFinalizationGroup> finalization_group(
-          JSFinalizationGroup::cast(
-              isolate()->heap()->dirty_js_finalization_groups()),
-          isolate());
-      isolate()->heap()->set_dirty_js_finalization_groups(
-          finalization_group->next());
-      finalization_group->set_next(ReadOnlyRoots(isolate()).undefined_value());
-      isolate()->RunHostCleanupFinalizationGroupCallback(finalization_group);
+    Handle<JSFinalizationRegistry> finalization_registry;
+    while (
+        DequeueDirtyJSFinalizationRegistry().ToHandle(&finalization_registry)) {
+      isolate()->RunHostCleanupFinalizationGroupCallback(finalization_registry);
     }
   }
 }
@@ -1250,11 +1246,9 @@ void Heap::HandleGCRequest() {
   }
 }
 
-
-void Heap::ScheduleIdleScavengeIfNeeded(int bytes_allocated) {
-  DCHECK(FLAG_idle_time_scavenge);
+void Heap::ScheduleScavengeTaskIfNeeded() {
   DCHECK_NOT_NULL(scavenge_job_);
-  scavenge_job_->ScheduleIdleTaskIfNeeded(this, bytes_allocated);
+  scavenge_job_->ScheduleTaskIfNeeded(this);
 }
 
 TimedHistogram* Heap::GCTypePriorityTimer(GarbageCollector collector) {
@@ -1288,17 +1282,18 @@ TimedHistogram* Heap::GCTypePriorityTimer(GarbageCollector collector) {
 TimedHistogram* Heap::GCTypeTimer(GarbageCollector collector) {
   if (IsYoungGenerationCollector(collector)) {
     return isolate_->counters()->gc_scavenger();
-  } else {
-    if (!incremental_marking()->IsStopped()) {
-      if (ShouldReduceMemory()) {
-        return isolate_->counters()->gc_finalize_reduce_memory();
-      } else {
-        return isolate_->counters()->gc_finalize();
-      }
-    } else {
-      return isolate_->counters()->gc_compactor();
-    }
   }
+  if (incremental_marking()->IsStopped()) {
+    return isolate_->counters()->gc_compactor();
+  }
+  if (ShouldReduceMemory()) {
+    return isolate_->counters()->gc_finalize_reduce_memory();
+  }
+  if (incremental_marking()->IsMarking() &&
+      incremental_marking()->marking_worklists()->IsPerContextMode()) {
+    return isolate_->counters()->gc_finalize_measure_memory();
+  }
+  return isolate_->counters()->gc_finalize();
 }
 
 void Heap::CollectAllGarbage(int flags, GarbageCollectionReason gc_reason,
@@ -1452,7 +1447,7 @@ void Heap::ReportExternalMemoryPressure() {
           kGCCallbackFlagSynchronousPhantomCallbackProcessing |
           kGCCallbackFlagCollectAllExternalMemory);
   if (isolate()->isolate_data()->external_memory_ >
-      (isolate()->isolate_data()->external_memory_at_last_mark_compact_ +
+      (isolate()->isolate_data()->external_memory_low_since_mark_compact_ +
        external_memory_hard_limit())) {
     CollectAllGarbage(
         kReduceMemoryFootprintMask,
@@ -1662,6 +1657,9 @@ int Heap::NotifyContextDisposed(bool dependant_context) {
     memory_reducer_->NotifyPossibleGarbage(event);
   }
   isolate()->AbortConcurrentOptimization(BlockingBehavior::kDontBlock);
+  if (!isolate()->context().is_null()) {
+    RemoveDirtyFinalizationRegistriesOnContext(isolate()->raw_native_context());
+  }
 
   number_of_disposed_maps_ = retained_maps().length();
   tracer()->AddContextDisposalTime(MonotonicallyIncreasingTimeInMs());
@@ -1845,8 +1843,13 @@ bool Heap::ReserveSpace(Reservation* reservations, std::vector<Address>* maps) {
         DCHECK_EQ(0, reserved_size % Map::kSize);
         int num_maps = reserved_size / Map::kSize;
         for (int i = 0; i < num_maps; i++) {
-          AllocationResult allocation =
-              map_space()->AllocateRawUnaligned(Map::kSize);
+          AllocationResult allocation;
+#if V8_ENABLE_THIRD_PARTY_HEAP_BOOL
+          allocation = AllocateRaw(Map::kSize, AllocationType::kMap,
+                                   AllocationOrigin::kRuntime, kWordAligned);
+#else
+          allocation = map_space()->AllocateRawUnaligned(Map::kSize);
+#endif
           HeapObject free_space;
           if (allocation.To(&free_space)) {
             // Mark with a free list node, in case we have a GC before
@@ -1873,12 +1876,24 @@ bool Heap::ReserveSpace(Reservation* reservations, std::vector<Address>* maps) {
           DCHECK_LE(static_cast<size_t>(size),
                     MemoryChunkLayout::AllocatableMemoryInMemoryChunk(
                         static_cast<AllocationSpace>(space)));
+#if V8_ENABLE_THIRD_PARTY_HEAP_BOOL
+          AllocationType type = (space == CODE_SPACE)
+                                    ? AllocationType::kCode
+                                    : (space == RO_SPACE)
+                                          ? AllocationType::kReadOnly
+                                          : AllocationType::kYoung;
+          AllocationAlignment align =
+              (space == CODE_SPACE) ? kCodeAligned : kWordAligned;
+          allocation =
+              AllocateRaw(size, type, AllocationOrigin::kRuntime, align);
+#else
           if (space == NEW_SPACE) {
             allocation = new_space()->AllocateRawUnaligned(size);
           } else {
             // The deserializer will update the skip list.
             allocation = paged_space(space)->AllocateRawUnaligned(size);
           }
+#endif
           HeapObject free_space;
           if (allocation.To(&free_space)) {
             // Mark with a free list node, in case we have a GC before
@@ -1995,6 +2010,13 @@ bool Heap::PerformGarbageCollection(
     }
   }
 
+  if (FLAG_local_heaps) safepoint()->Start();
+#ifdef VERIFY_HEAP
+  if (FLAG_verify_heap) {
+    Verify();
+  }
+#endif
+
   EnsureFromSpaceIsCommitted();
 
   size_t start_young_generation_size =
@@ -2068,6 +2090,13 @@ bool Heap::PerformGarbageCollection(
     local_embedder_heap_tracer()->TraceEpilogue();
   }
 
+#ifdef VERIFY_HEAP
+  if (FLAG_verify_heap) {
+    Verify();
+  }
+#endif
+  if (FLAG_local_heaps) safepoint()->End();
+
   {
     TRACE_GC(tracer(), GCTracer::Scope::HEAP_EXTERNAL_WEAK_GLOBAL_HANDLES);
     gc_post_processing_depth_++;
@@ -2143,7 +2172,7 @@ void Heap::RecomputeLimits(GarbageCollector collector) {
 
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
-    isolate()->isolate_data()->external_memory_at_last_mark_compact_ =
+    isolate()->isolate_data()->external_memory_low_since_mark_compact_ =
         isolate()->isolate_data()->external_memory_;
     isolate()->isolate_data()->external_memory_limit_ =
         isolate()->isolate_data()->external_memory_ +
@@ -2248,7 +2277,7 @@ void Heap::MinorMarkCompact() {
   LOG(isolate_, ResourceEvent("MinorMarkCompact", "begin"));
 
   TRACE_GC(tracer(), GCTracer::Scope::MINOR_MC);
-  AlwaysAllocateScope always_allocate(isolate());
+  AlwaysAllocateScope always_allocate(this);
   IncrementalMarking::PauseBlackAllocationScope pause_black_allocation(
       incremental_marking());
   ConcurrentMarking::PauseScope pause_scope(concurrent_marking());
@@ -2287,16 +2316,8 @@ void Heap::MarkCompactPrologue() {
 
 
 void Heap::CheckNewSpaceExpansionCriteria() {
-  if (FLAG_experimental_new_space_growth_heuristic) {
-    if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() &&
-        survived_last_scavenge_ * 100 / new_space_->TotalCapacity() >= 10) {
-      // Grow the size of new space if there is room to grow, and more than 10%
-      // have survived the last scavenge.
-      new_space_->Grow();
-      survived_since_last_expansion_ = 0;
-    }
-  } else if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() &&
-             survived_since_last_expansion_ > new_space_->TotalCapacity()) {
+  if (new_space_->TotalCapacity() < new_space_->MaximumCapacity() &&
+      survived_since_last_expansion_ > new_space_->TotalCapacity()) {
     // Grow the size of new space if there is room to grow, and enough data
     // has survived scavenge since the last expansion.
     new_space_->Grow();
@@ -2365,7 +2386,7 @@ void Heap::Scavenge() {
   // There are soft limits in the allocation code, designed to trigger a mark
   // sweep collection by failing allocations. There is no sense in trying to
   // trigger one during scavenge: scavenges allocation should always succeed.
-  AlwaysAllocateScope scope(isolate());
+  AlwaysAllocateScope scope(this);
 
   // Bump-pointer allocations done during scavenge are not real allocations.
   // Pause the inline allocation steps.
@@ -2636,6 +2657,7 @@ void Heap::UpdateReferencesInExternalStringTable(
 void Heap::ProcessAllWeakReferences(WeakObjectRetainer* retainer) {
   ProcessNativeContexts(retainer);
   ProcessAllocationSites(retainer);
+  ProcessDirtyJSFinalizationRegistries(retainer);
 }
 
 
@@ -2657,9 +2679,24 @@ void Heap::ProcessAllocationSites(WeakObjectRetainer* retainer) {
   set_allocation_sites_list(allocation_site_obj);
 }
 
+void Heap::ProcessDirtyJSFinalizationRegistries(WeakObjectRetainer* retainer) {
+  Object head = VisitWeakList<JSFinalizationRegistry>(
+      this, dirty_js_finalization_registries_list(), retainer);
+  set_dirty_js_finalization_registries_list(head);
+  // If the list is empty, set the tail to undefined. Otherwise the tail is set
+  // by WeakListVisitor<JSFinalizationRegistry>::VisitLiveObject.
+  if (head.IsUndefined(isolate())) {
+    set_dirty_js_finalization_registries_list_tail(head);
+  }
+}
+
 void Heap::ProcessWeakListRoots(WeakObjectRetainer* retainer) {
   set_native_contexts_list(retainer->RetainAs(native_contexts_list()));
   set_allocation_sites_list(retainer->RetainAs(allocation_sites_list()));
+  set_dirty_js_finalization_registries_list(
+      retainer->RetainAs(dirty_js_finalization_registries_list()));
+  set_dirty_js_finalization_registries_list_tail(
+      retainer->RetainAs(dirty_js_finalization_registries_list_tail()));
 }
 
 void Heap::ForeachAllocationSite(
@@ -2813,25 +2850,32 @@ HeapObject Heap::AlignWithFiller(HeapObject object, int object_size,
 
 void* Heap::AllocateExternalBackingStore(
     const std::function<void*(size_t)>& allocate, size_t byte_length) {
-  size_t new_space_backing_store_bytes =
-      new_space()->ExternalBackingStoreBytes();
-  if (new_space_backing_store_bytes >= 2 * kMaxSemiSpaceSize &&
-      new_space_backing_store_bytes >= byte_length) {
-    // Performing a young generation GC amortizes over the allocated backing
-    // store bytes and may free enough external bytes for this allocation.
-    CollectGarbage(NEW_SPACE, GarbageCollectionReason::kExternalMemoryPressure);
+  if (!always_allocate()) {
+    size_t new_space_backing_store_bytes =
+        new_space()->ExternalBackingStoreBytes();
+    if (new_space_backing_store_bytes >= 2 * kMaxSemiSpaceSize &&
+        new_space_backing_store_bytes >= byte_length) {
+      // Performing a young generation GC amortizes over the allocated backing
+      // store bytes and may free enough external bytes for this allocation.
+      CollectGarbage(NEW_SPACE,
+                     GarbageCollectionReason::kExternalMemoryPressure);
+    }
   }
   // TODO(ulan): Perform GCs proactively based on the byte_length and
   // the current external backing store counters.
   void* result = allocate(byte_length);
   if (result) return result;
-  for (int i = 0; i < 2; i++) {
-    CollectGarbage(OLD_SPACE, GarbageCollectionReason::kExternalMemoryPressure);
-    result = allocate(byte_length);
-    if (result) return result;
+  if (!always_allocate()) {
+    for (int i = 0; i < 2; i++) {
+      CollectGarbage(OLD_SPACE,
+                     GarbageCollectionReason::kExternalMemoryPressure);
+      result = allocate(byte_length);
+      if (result) return result;
+    }
+    isolate()->counters()->gc_last_resort_from_handles()->Increment();
+    CollectAllAvailableGarbage(
+        GarbageCollectionReason::kExternalMemoryPressure);
   }
-  isolate()->counters()->gc_last_resort_from_handles()->Increment();
-  CollectAllAvailableGarbage(GarbageCollectionReason::kExternalMemoryPressure);
   return allocate(byte_length);
 }
 
@@ -2941,6 +2985,23 @@ bool Heap::CanMoveObjectStart(HeapObject object) {
   return Page::FromHeapObject(object)->SweepingDone();
 }
 
+// static
+bool Heap::InOffThreadSpace(HeapObject heap_object) {
+#ifdef V8_ENABLE_THIRD_PARTY_HEAP
+  return false;  // currently unsupported
+#else
+  Space* owner = MemoryChunk::FromHeapObject(heap_object)->owner();
+  if (owner->identity() == OLD_SPACE) {
+    // TODO(leszeks): Should we exclude compaction spaces here?
+    return static_cast<PagedSpace*>(owner)->is_off_thread_space();
+  }
+  if (owner->identity() == LO_SPACE) {
+    return static_cast<LargeObjectSpace*>(owner)->is_off_thread();
+  }
+  return false;
+#endif
+}
+
 bool Heap::IsImmovable(HeapObject object) {
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
     // TODO(steveblackburn): For now all objects are immovable.
@@ -3909,8 +3970,8 @@ const char* Heap::GarbageCollectionReasonToString(
       return "full hash-table";
     case GarbageCollectionReason::kHeapProfiler:
       return "heap profiler";
-    case GarbageCollectionReason::kIdleTask:
-      return "idle task";
+    case GarbageCollectionReason::kTask:
+      return "task";
     case GarbageCollectionReason::kLastResort:
       return "last resort";
     case GarbageCollectionReason::kLowMemoryNotification:
@@ -4057,6 +4118,7 @@ void Heap::Verify() {
 
   // We have to wait here for the sweeper threads to have an iterable heap.
   mark_compact_collector()->EnsureSweepingCompleted();
+  array_buffer_sweeper()->EnsureFinished();
 
   VerifyPointersVisitor visitor(this);
   IterateRoots(&visitor, VISIT_ONLY_STRONG);
@@ -4392,6 +4454,7 @@ void Heap::IterateStrongRoots(RootVisitor* v, VisitMode mode) {
   v->Synchronize(VisitorSynchronization::kBootstrapper);
   if (mode != VISIT_ONLY_STRONG_IGNORE_STACK) {
     isolate_->Iterate(v);
+    isolate_->global_handles()->IterateStrongStackRoots(v);
     v->Synchronize(VisitorSynchronization::kTop);
   }
   Relocatable::Iterate(isolate_, v);
@@ -4406,6 +4469,12 @@ void Heap::IterateStrongRoots(RootVisitor* v, VisitMode mode) {
   FixStaleLeftTrimmedHandlesVisitor left_trim_visitor(this);
   isolate_->handle_scope_implementer()->Iterate(&left_trim_visitor);
   isolate_->handle_scope_implementer()->Iterate(v);
+
+  if (FLAG_local_heaps) {
+    safepoint_->Iterate(&left_trim_visitor);
+    safepoint_->Iterate(v);
+  }
+
   isolate_->IterateDeferredHandles(&left_trim_visitor);
   isolate_->IterateDeferredHandles(v);
   v->Synchronize(VisitorSynchronization::kHandleScope);
@@ -4743,12 +4812,12 @@ size_t Heap::GlobalSizeOfObjects() {
 uint64_t Heap::PromotedExternalMemorySize() {
   IsolateData* isolate_data = isolate()->isolate_data();
   if (isolate_data->external_memory_ <=
-      isolate_data->external_memory_at_last_mark_compact_) {
+      isolate_data->external_memory_low_since_mark_compact_) {
     return 0;
   }
   return static_cast<uint64_t>(
       isolate_data->external_memory_ -
-      isolate_data->external_memory_at_last_mark_compact_);
+      isolate_data->external_memory_low_since_mark_compact_);
 }
 
 bool Heap::AllocationLimitOvershotByLargeMargin() {
@@ -4871,7 +4940,7 @@ Heap::IncrementalMarkingLimit Heap::IncrementalMarkingLimitReached() {
     double gained_since_last_gc =
         PromotedSinceLastGC() +
         (isolate()->isolate_data()->external_memory_ -
-         isolate()->isolate_data()->external_memory_at_last_mark_compact_);
+         isolate()->isolate_data()->external_memory_low_since_mark_compact_);
     double size_before_gc =
         OldGenerationObjectsAndPromotedExternalMemorySize() -
         gained_since_last_gc;
@@ -5006,7 +5075,7 @@ HeapObject Heap::AllocateRawWithRetryOrFailSlowPath(
   isolate()->counters()->gc_last_resort_from_handles()->Increment();
   CollectAllAvailableGarbage(GarbageCollectionReason::kLastResort);
   {
-    AlwaysAllocateScope scope(isolate());
+    AlwaysAllocateScope scope(this);
     alloc = AllocateRaw(size, allocation, origin, alignment);
   }
   if (alloc.To(&result)) {
@@ -5040,7 +5109,7 @@ HeapObject Heap::AllocateRawCodeInLargeObjectSpace(int size) {
   isolate()->counters()->gc_last_resort_from_handles()->Increment();
   CollectAllAvailableGarbage(GarbageCollectionReason::kLastResort);
   {
-    AlwaysAllocateScope scope(isolate());
+    AlwaysAllocateScope scope(this);
     alloc = code_lo_space()->AllocateRaw(size);
   }
   if (alloc.To(&result)) {
@@ -5058,8 +5127,7 @@ void Heap::SetUp() {
 #endif
 
 #ifdef V8_ENABLE_THIRD_PARTY_HEAP
-  tp_heap_ =
-      third_party_heap::Heap::New(reinterpret_cast<v8::Isolate*>(isolate()));
+  tp_heap_ = third_party_heap::Heap::New(isolate());
 #endif
 
   // Initialize heap spaces and initial maps and objects.
@@ -5151,12 +5219,10 @@ void Heap::SetUpSpaces() {
   }
 #endif  // ENABLE_MINOR_MC
 
-  if (FLAG_idle_time_scavenge) {
-    scavenge_job_.reset(new ScavengeJob());
-    idle_scavenge_observer_.reset(new IdleScavengeObserver(
-        this, ScavengeJob::kBytesAllocatedBeforeNextIdleTask));
-    new_space()->AddAllocationObserver(idle_scavenge_observer_.get());
-  }
+  scavenge_job_.reset(new ScavengeJob());
+  scavenge_task_observer_.reset(new ScavengeTaskObserver(
+      this, ScavengeJob::YoungGenerationTaskTriggerSize(this)));
+  new_space()->AddAllocationObserver(scavenge_task_observer_.get());
 
   SetGetExternallyAllocatedMemoryInBytesCallback(
       DefaultGetExternallyAllocatedMemoryInBytesCallback);
@@ -5336,11 +5402,9 @@ void Heap::TearDown() {
     }
   }
 
-  if (FLAG_idle_time_scavenge) {
-    new_space()->RemoveAllocationObserver(idle_scavenge_observer_.get());
-    idle_scavenge_observer_.reset();
-    scavenge_job_.reset();
-  }
+  new_space()->RemoveAllocationObserver(scavenge_task_observer_.get());
+  scavenge_task_observer_.reset();
+  scavenge_job_.reset();
 
   if (FLAG_stress_marking > 0) {
     RemoveAllocationObserversFromAllSpaces(stress_marking_observer_,
@@ -5966,6 +6030,16 @@ void Heap::RememberUnmappedPage(Address page, bool compacted) {
   remembered_unmapped_pages_index_ %= kRememberedUnmappedPages;
 }
 
+size_t Heap::YoungArrayBufferBytes() {
+  DCHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
+  return array_buffer_sweeper()->YoungBytes();
+}
+
+size_t Heap::OldArrayBufferBytes() {
+  DCHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
+  return array_buffer_sweeper()->OldBytes();
+}
+
 void Heap::RegisterStrongRoots(FullObjectSlot start, FullObjectSlot end) {
   StrongRootsList* list = new StrongRootsList();
   list->next = strong_roots_list_;
@@ -6002,23 +6076,96 @@ void Heap::SetInterpreterEntryTrampolineForProfiling(Code code) {
   set_interpreter_entry_trampoline_for_profiling(code);
 }
 
-void Heap::AddDirtyJSFinalizationGroup(
-    JSFinalizationGroup finalization_group,
+void Heap::PostFinalizationRegistryCleanupTaskIfNeeded() {
+  DCHECK(!isolate()->host_cleanup_finalization_group_callback());
+  // Only one cleanup task is posted at a time.
+  if (!HasDirtyJSFinalizationRegistries() ||
+      is_finalization_registry_cleanup_task_posted_) {
+    return;
+  }
+  auto taskrunner = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
+      reinterpret_cast<v8::Isolate*>(isolate()));
+  auto task = std::make_unique<FinalizationRegistryCleanupTask>(this);
+  taskrunner->PostNonNestableTask(std::move(task));
+  is_finalization_registry_cleanup_task_posted_ = true;
+}
+
+void Heap::EnqueueDirtyJSFinalizationRegistry(
+    JSFinalizationRegistry finalization_registry,
     std::function<void(HeapObject object, ObjectSlot slot, Object target)>
         gc_notify_updated_slot) {
-  DCHECK(dirty_js_finalization_groups().IsUndefined(isolate()) ||
-         dirty_js_finalization_groups().IsJSFinalizationGroup());
-  DCHECK(finalization_group.next().IsUndefined(isolate()));
-  DCHECK(!finalization_group.scheduled_for_cleanup());
-  finalization_group.set_scheduled_for_cleanup(true);
-  finalization_group.set_next(dirty_js_finalization_groups());
-  gc_notify_updated_slot(
-      finalization_group,
-      finalization_group.RawField(JSFinalizationGroup::kNextOffset),
-      dirty_js_finalization_groups());
-  set_dirty_js_finalization_groups(finalization_group);
-  // Roots are rescanned after objects are moved, so no need to record a slot
-  // for the root pointing to the first JSFinalizationGroup.
+  // Add a FinalizationRegistry to the tail of the dirty list.
+  DCHECK(!HasDirtyJSFinalizationRegistries() ||
+         dirty_js_finalization_registries_list().IsJSFinalizationRegistry());
+  DCHECK(finalization_registry.next_dirty().IsUndefined(isolate()));
+  DCHECK(!finalization_registry.scheduled_for_cleanup());
+  finalization_registry.set_scheduled_for_cleanup(true);
+  if (dirty_js_finalization_registries_list_tail().IsUndefined(isolate())) {
+    DCHECK(dirty_js_finalization_registries_list().IsUndefined(isolate()));
+    set_dirty_js_finalization_registries_list(finalization_registry);
+    // dirty_js_finalization_registries_list_ is rescanned by
+    // ProcessWeakListRoots.
+  } else {
+    JSFinalizationRegistry tail = JSFinalizationRegistry::cast(
+        dirty_js_finalization_registries_list_tail());
+    tail.set_next_dirty(finalization_registry);
+    gc_notify_updated_slot(tail,
+                           finalization_registry.RawField(
+                               JSFinalizationRegistry::kNextDirtyOffset),
+                           finalization_registry);
+  }
+  set_dirty_js_finalization_registries_list_tail(finalization_registry);
+  // dirty_js_finalization_registries_list_tail_ is rescanned by
+  // ProcessWeakListRoots.
+}
+
+MaybeHandle<JSFinalizationRegistry> Heap::DequeueDirtyJSFinalizationRegistry() {
+  // Take a FinalizationRegistry from the head of the dirty list for fairness.
+  if (HasDirtyJSFinalizationRegistries()) {
+    Handle<JSFinalizationRegistry> head(
+        JSFinalizationRegistry::cast(dirty_js_finalization_registries_list()),
+        isolate());
+    set_dirty_js_finalization_registries_list(head->next_dirty());
+    head->set_next_dirty(ReadOnlyRoots(this).undefined_value());
+    if (*head == dirty_js_finalization_registries_list_tail()) {
+      set_dirty_js_finalization_registries_list_tail(
+          ReadOnlyRoots(this).undefined_value());
+    }
+    return head;
+  }
+  return {};
+}
+
+void Heap::RemoveDirtyFinalizationRegistriesOnContext(NativeContext context) {
+  if (!FLAG_harmony_weak_refs) return;
+  if (isolate()->host_cleanup_finalization_group_callback()) return;
+
+  DisallowHeapAllocation no_gc;
+
+  Isolate* isolate = this->isolate();
+  Object prev = ReadOnlyRoots(isolate).undefined_value();
+  Object current = dirty_js_finalization_registries_list();
+  while (!current.IsUndefined(isolate)) {
+    JSFinalizationRegistry finalization_registry =
+        JSFinalizationRegistry::cast(current);
+    if (finalization_registry.native_context() == context) {
+      if (prev.IsUndefined(isolate)) {
+        set_dirty_js_finalization_registries_list(
+            finalization_registry.next_dirty());
+      } else {
+        JSFinalizationRegistry::cast(prev).set_next_dirty(
+            finalization_registry.next_dirty());
+      }
+      finalization_registry.set_scheduled_for_cleanup(false);
+      current = finalization_registry.next_dirty();
+      finalization_registry.set_next_dirty(
+          ReadOnlyRoots(isolate).undefined_value());
+    } else {
+      prev = current;
+      current = finalization_registry.next_dirty();
+    }
+  }
+  set_dirty_js_finalization_registries_list_tail(prev);
 }
 
 void Heap::KeepDuringJob(Handle<JSReceiver> target) {
@@ -6527,7 +6674,7 @@ bool Heap::PageFlagsAreConsistent(HeapObject object) {
   CHECK_EQ(chunk->InReadOnlySpace(), slim_chunk->InReadOnlySpace());
 
   // Marking consistency.
-  if (chunk->IsWritable()) {
+  if (chunk->IsWritable() && !Heap::InOffThreadSpace(object)) {
     // RO_SPACE can be shared between heaps, so we can't use RO_SPACE objects to
     // find a heap. The exception is when the ReadOnlySpace is writeable, during
     // bootstrapping, so explicitly allow this case.
diff --git a/deps/v8/src/heap/heap.h b/deps/v8/src/heap/heap.h
index 86dbab60a7..6d6eddf61a 100644
--- a/deps/v8/src/heap/heap.h
+++ b/deps/v8/src/heap/heap.h
@@ -70,8 +70,9 @@ class HeapObjectAllocationTracker;
 class HeapObjectsFilter;
 class HeapStats;
 class Isolate;
-class JSFinalizationGroup;
+class JSFinalizationRegistry;
 class LocalEmbedderHeapTracer;
+class LocalHeap;
 class MemoryAllocator;
 class MemoryMeasurement;
 class MemoryReducer;
@@ -82,6 +83,7 @@ class Page;
 class PagedSpace;
 class ReadOnlyHeap;
 class RootVisitor;
+class Safepoint;
 class ScavengeJob;
 class Scavenger;
 class ScavengerCollector;
@@ -127,7 +129,7 @@ enum class GarbageCollectionReason {
   kFinalizeMarkingViaTask = 9,
   kFullHashtable = 10,
   kHeapProfiler = 11,
-  kIdleTask = 12,
+  kTask = 12,
   kLastResort = 13,
   kLowMemoryNotification = 14,
   kMakeHeapIterable = 15,
@@ -502,6 +504,19 @@ class Heap {
   }
   Object allocation_sites_list() { return allocation_sites_list_; }
 
+  void set_dirty_js_finalization_registries_list(Object object) {
+    dirty_js_finalization_registries_list_ = object;
+  }
+  Object dirty_js_finalization_registries_list() {
+    return dirty_js_finalization_registries_list_;
+  }
+  void set_dirty_js_finalization_registries_list_tail(Object object) {
+    dirty_js_finalization_registries_list_tail_ = object;
+  }
+  Object dirty_js_finalization_registries_list_tail() {
+    return dirty_js_finalization_registries_list_tail_;
+  }
+
   // Used in CreateAllocationSiteStub and the (de)serializer.
   Address allocation_sites_list_address() {
     return reinterpret_cast<Address>(&allocation_sites_list_);
@@ -605,6 +620,8 @@ class Heap {
   void AppendArrayBufferExtension(JSArrayBuffer object,
                                   ArrayBufferExtension* extension);
 
+  Safepoint* safepoint() { return safepoint_.get(); }
+
   V8_EXPORT_PRIVATE double MonotonicallyIncreasingTimeInMs();
 
   void RecordStats(HeapStats* stats, bool take_snapshot = false);
@@ -644,6 +661,9 @@ class Heap {
   V8_INLINE void update_external_memory_concurrently_freed(uintptr_t freed);
   V8_INLINE void account_external_memory_concurrently_freed();
 
+  V8_EXPORT_PRIVATE size_t YoungArrayBufferBytes();
+  V8_EXPORT_PRIVATE size_t OldArrayBufferBytes();
+
   size_t backing_store_bytes() const { return backing_store_bytes_; }
 
   void CompactWeakArrayLists(AllocationType allocation);
@@ -763,6 +783,8 @@ class Heap {
     return array_buffer_sweeper_.get();
   }
 
+  const base::AddressRegion& code_range();
+
   // ===========================================================================
   // Root set access. ==========================================================
   // ===========================================================================
@@ -795,12 +817,31 @@ class Heap {
   // See also: FLAG_interpreted_frames_native_stack.
   void SetInterpreterEntryTrampolineForProfiling(Code code);
 
-  // Add finalization_group into the dirty_js_finalization_groups list.
-  void AddDirtyJSFinalizationGroup(
-      JSFinalizationGroup finalization_group,
+  void EnqueueDirtyJSFinalizationRegistry(
+      JSFinalizationRegistry finalization_registry,
       std::function<void(HeapObject object, ObjectSlot slot, Object target)>
           gc_notify_updated_slot);
 
+  MaybeHandle<JSFinalizationRegistry> DequeueDirtyJSFinalizationRegistry();
+
+  // Called from Heap::NotifyContextDisposed to remove all
+  // FinalizationRegistries with {context} from the dirty list when the context
+  // e.g. navigates away or is detached. If the dirty list is empty afterwards,
+  // the cleanup task is aborted if needed.
+  void RemoveDirtyFinalizationRegistriesOnContext(NativeContext context);
+
+  inline bool HasDirtyJSFinalizationRegistries();
+
+  void PostFinalizationRegistryCleanupTaskIfNeeded();
+
+  void set_is_finalization_registry_cleanup_task_posted(bool posted) {
+    is_finalization_registry_cleanup_task_posted_ = posted;
+  }
+
+  bool is_finalization_registry_cleanup_task_posted() {
+    return is_finalization_registry_cleanup_task_posted_;
+  }
+
   V8_EXPORT_PRIVATE void KeepDuringJob(Handle<JSReceiver> target);
   void ClearKeptObjects();
 
@@ -1043,6 +1084,8 @@ class Heap {
   static inline bool InToPage(MaybeObject object);
   static inline bool InToPage(HeapObject heap_object);
 
+  V8_EXPORT_PRIVATE static bool InOffThreadSpace(HeapObject heap_object);
+
   // Returns whether the object resides in old space.
   inline bool InOldSpace(Object object);
 
@@ -1156,9 +1199,15 @@ class Heap {
   // all available bytes. Check MaxHeapObjectSize() instead.
   size_t Available();
 
-  // Returns of size of all objects residing in the heap.
+  // Returns size of all objects residing in the heap.
   V8_EXPORT_PRIVATE size_t SizeOfObjects();
 
+  // Returns size of all global handles in the heap.
+  V8_EXPORT_PRIVATE size_t TotalGlobalHandlesSize();
+
+  // Returns size of all allocated/used global handles in the heap.
+  V8_EXPORT_PRIVATE size_t UsedGlobalHandlesSize();
+
   void UpdateSurvivalStatistics(int start_new_space_size);
 
   inline void IncrementPromotedObjectsSize(size_t object_size) {
@@ -1518,7 +1567,6 @@ class Heap {
   static const int kOldSurvivalRateLowThreshold = 10;
 
   static const int kMaxMarkCompactsInIdleRound = 7;
-  static const int kIdleScavengeThreshold = 5;
 
   static const int kInitialFeedbackCapacity = 256;
 
@@ -1709,6 +1757,7 @@ class Heap {
   void ProcessYoungWeakReferences(WeakObjectRetainer* retainer);
   void ProcessNativeContexts(WeakObjectRetainer* retainer);
   void ProcessAllocationSites(WeakObjectRetainer* retainer);
+  void ProcessDirtyJSFinalizationRegistries(WeakObjectRetainer* retainer);
   void ProcessWeakListRoots(WeakObjectRetainer* retainer);
 
   // ===========================================================================
@@ -1783,7 +1832,12 @@ class Heap {
   // ===========================================================================
 
   bool RecentIdleNotificationHappened();
-  void ScheduleIdleScavengeIfNeeded(int bytes_allocated);
+
+  // ===========================================================================
+  // GC Tasks. =================================================================
+  // ===========================================================================
+
+  void ScheduleScavengeTaskIfNeeded();
 
   // ===========================================================================
   // Allocation methods. =======================================================
@@ -2013,6 +2067,9 @@ class Heap {
   // List heads are initialized lazily and contain the undefined_value at start.
   Object native_contexts_list_;
   Object allocation_sites_list_;
+  Object dirty_js_finalization_registries_list_;
+  // Weak list tails.
+  Object dirty_js_finalization_registries_list_tail_;
 
   std::vector<GCCallbackTuple> gc_epilogue_callbacks_;
   std::vector<GCCallbackTuple> gc_prologue_callbacks_;
@@ -2062,7 +2119,7 @@ class Heap {
   std::unique_ptr<ObjectStats> live_object_stats_;
   std::unique_ptr<ObjectStats> dead_object_stats_;
   std::unique_ptr<ScavengeJob> scavenge_job_;
-  std::unique_ptr<AllocationObserver> idle_scavenge_observer_;
+  std::unique_ptr<AllocationObserver> scavenge_task_observer_;
   std::unique_ptr<LocalEmbedderHeapTracer> local_embedder_heap_tracer_;
   StrongRootsList* strong_roots_list_ = nullptr;
 
@@ -2109,6 +2166,8 @@ class Heap {
   GCCallbackFlags current_gc_callback_flags_ =
       GCCallbackFlags::kNoGCCallbackFlags;
 
+  std::unique_ptr<Safepoint> safepoint_;
+
   bool is_current_gc_forced_ = false;
 
   ExternalStringTable external_string_table_;
@@ -2149,6 +2208,8 @@ class Heap {
 
   std::vector<HeapObjectAllocationTracker*> allocation_trackers_;
 
+  bool is_finalization_registry_cleanup_task_posted_ = false;
+
   std::unique_ptr<third_party_heap::Heap> tp_heap_;
 
   // Classes in "heap" can be friends.
@@ -2159,7 +2220,7 @@ class Heap {
   friend class GCCallbacksScope;
   friend class GCTracer;
   friend class HeapObjectIterator;
-  friend class IdleScavengeObserver;
+  friend class ScavengeTaskObserver;
   friend class IncrementalMarking;
   friend class IncrementalMarkingJob;
   friend class OldLargeObjectSpace;
@@ -2227,16 +2288,33 @@ class HeapStats {
   intptr_t* end_marker;                    // 27
 };
 
+// Disables GC for all allocations. It should not be used
+// outside heap, deserializer, and isolate bootstrap.
+// Use AlwaysAllocateScopeForTesting in tests.
 class AlwaysAllocateScope {
  public:
-  explicit inline AlwaysAllocateScope(Heap* heap);
-  explicit inline AlwaysAllocateScope(Isolate* isolate);
   inline ~AlwaysAllocateScope();
 
  private:
+  friend class AlwaysAllocateScopeForTesting;
+  friend class Deserializer;
+  friend class DeserializerAllocator;
+  friend class Evacuator;
+  friend class Heap;
+  friend class Isolate;
+
+  explicit inline AlwaysAllocateScope(Heap* heap);
   Heap* heap_;
 };
 
+class AlwaysAllocateScopeForTesting {
+ public:
+  explicit inline AlwaysAllocateScopeForTesting(Heap* heap);
+
+ private:
+  AlwaysAllocateScope scope_;
+};
+
 // The CodeSpaceMemoryModificationScope can only be used by the main thread.
 class CodeSpaceMemoryModificationScope {
  public:
diff --git a/deps/v8/src/heap/incremental-marking-job.cc b/deps/v8/src/heap/incremental-marking-job.cc
index 1f924ff139..63e47ca313 100644
--- a/deps/v8/src/heap/incremental-marking-job.cc
+++ b/deps/v8/src/heap/incremental-marking-job.cc
@@ -8,6 +8,7 @@
 #include "src/execution/isolate.h"
 #include "src/execution/vm-state-inl.h"
 #include "src/heap/embedder-tracing.h"
+#include "src/heap/gc-tracer.h"
 #include "src/heap/heap-inl.h"
 #include "src/heap/heap.h"
 #include "src/heap/incremental-marking.h"
@@ -18,8 +19,7 @@ namespace internal {
 
 class IncrementalMarkingJob::Task : public CancelableTask {
  public:
-  static StepResult Step(Heap* heap,
-                         EmbedderHeapTracer::EmbedderStackState stack_state);
+  static StepResult Step(Heap* heap);
 
   Task(Isolate* isolate, IncrementalMarkingJob* job,
        EmbedderHeapTracer::EmbedderStackState stack_state, TaskType task_type)
@@ -52,48 +52,39 @@ void IncrementalMarkingJob::ScheduleTask(Heap* heap, TaskType task_type) {
     SetTaskPending(task_type, true);
     auto taskrunner =
         V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate);
+    const EmbedderHeapTracer::EmbedderStackState stack_state =
+        taskrunner->NonNestableTasksEnabled()
+            ? EmbedderHeapTracer::EmbedderStackState::kEmpty
+            : EmbedderHeapTracer::EmbedderStackState::kUnknown;
+    auto task =
+        std::make_unique<Task>(heap->isolate(), this, stack_state, task_type);
     if (task_type == TaskType::kNormal) {
+      scheduled_time_ = heap->MonotonicallyIncreasingTimeInMs();
       if (taskrunner->NonNestableTasksEnabled()) {
-        taskrunner->PostNonNestableTask(std::make_unique<Task>(
-            heap->isolate(), this,
-            EmbedderHeapTracer::EmbedderStackState::kEmpty, task_type));
+        taskrunner->PostNonNestableTask(std::move(task));
       } else {
-        taskrunner->PostTask(std::make_unique<Task>(
-            heap->isolate(), this,
-            EmbedderHeapTracer::EmbedderStackState::kUnknown, task_type));
+        taskrunner->PostTask(std::move(task));
       }
     } else {
       if (taskrunner->NonNestableDelayedTasksEnabled()) {
-        taskrunner->PostNonNestableDelayedTask(
-            std::make_unique<Task>(
-                heap->isolate(), this,
-                EmbedderHeapTracer::EmbedderStackState::kEmpty, task_type),
-            kDelayInSeconds);
+        taskrunner->PostNonNestableDelayedTask(std::move(task),
+                                               kDelayInSeconds);
       } else {
-        taskrunner->PostDelayedTask(
-            std::make_unique<Task>(
-                heap->isolate(), this,
-                EmbedderHeapTracer::EmbedderStackState::kUnknown, task_type),
-            kDelayInSeconds);
+        taskrunner->PostDelayedTask(std::move(task), kDelayInSeconds);
       }
     }
   }
 }
 
-StepResult IncrementalMarkingJob::Task::Step(
-    Heap* heap, EmbedderHeapTracer::EmbedderStackState stack_state) {
+StepResult IncrementalMarkingJob::Task::Step(Heap* heap) {
   const int kIncrementalMarkingDelayMs = 1;
   double deadline =
       heap->MonotonicallyIncreasingTimeInMs() + kIncrementalMarkingDelayMs;
   StepResult result = heap->incremental_marking()->AdvanceWithDeadline(
       deadline, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
       i::StepOrigin::kTask);
-  {
-    EmbedderStackStateScope scope(heap->local_embedder_heap_tracer(),
-                                  stack_state);
-    heap->FinalizeIncrementalMarkingIfComplete(
-        GarbageCollectionReason::kFinalizeMarkingViaTask);
-  }
+  heap->FinalizeIncrementalMarkingIfComplete(
+      GarbageCollectionReason::kFinalizeMarkingViaTask);
   return result;
 }
 
@@ -102,12 +93,19 @@ void IncrementalMarkingJob::Task::RunInternal() {
   TRACE_EVENT_CALL_STATS_SCOPED(isolate(), "v8", "V8.Task");
 
   Heap* heap = isolate()->heap();
+  EmbedderStackStateScope scope(heap->local_embedder_heap_tracer(),
+                                stack_state_);
+  if (task_type_ == TaskType::kNormal) {
+    heap->tracer()->RecordTimeToIncrementalMarkingTask(
+        heap->MonotonicallyIncreasingTimeInMs() - job_->scheduled_time_);
+    job_->scheduled_time_ = 0.0;
+  }
   IncrementalMarking* incremental_marking = heap->incremental_marking();
   if (incremental_marking->IsStopped()) {
     if (heap->IncrementalMarkingLimitReached() !=
         Heap::IncrementalMarkingLimit::kNoLimit) {
       heap->StartIncrementalMarking(heap->GCFlagsForIncrementalMarking(),
-                                    GarbageCollectionReason::kIdleTask,
+                                    GarbageCollectionReason::kTask,
                                     kGCCallbackScheduleIdleGarbageCollection);
     }
   }
@@ -117,14 +115,23 @@ void IncrementalMarkingJob::Task::RunInternal() {
   job_->SetTaskPending(task_type_, false);
 
   if (!incremental_marking->IsStopped()) {
-    StepResult step_result = Step(heap, stack_state_);
+    StepResult step_result = Step(heap);
     if (!incremental_marking->IsStopped()) {
-      job_->ScheduleTask(heap, step_result == StepResult::kNoImmediateWork
-                                   ? TaskType::kDelayed
-                                   : TaskType::kNormal);
+      const TaskType task_type =
+          incremental_marking->finalize_marking_completed() ||
+                  step_result != StepResult::kNoImmediateWork
+              ? TaskType::kNormal
+              : TaskType::kDelayed;
+      job_->ScheduleTask(heap, task_type);
     }
   }
 }
 
+double IncrementalMarkingJob::CurrentTimeToTask(Heap* heap) const {
+  if (scheduled_time_ == 0.0) return 0.0;
+
+  return heap->MonotonicallyIncreasingTimeInMs() - scheduled_time_;
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/incremental-marking-job.h b/deps/v8/src/heap/incremental-marking-job.h
index 145f1dca64..ed133e88e5 100644
--- a/deps/v8/src/heap/incremental-marking-job.h
+++ b/deps/v8/src/heap/incremental-marking-job.h
@@ -16,7 +16,7 @@ class Isolate;
 // The incremental marking job uses platform tasks to perform incremental
 // marking steps. The job posts a foreground task that makes a small (~1ms)
 // step and posts another task until the marking is completed.
-class IncrementalMarkingJob {
+class IncrementalMarkingJob final {
  public:
   enum class TaskType { kNormal, kDelayed };
 
@@ -26,14 +26,17 @@ class IncrementalMarkingJob {
 
   void ScheduleTask(Heap* heap, TaskType task_type = TaskType::kNormal);
 
- private:
-  class Task;
-  static constexpr double kDelayInSeconds = 10.0 / 1000.0;
+  double CurrentTimeToTask(Heap* heap) const;
 
-  bool IsTaskPending(TaskType task_type) {
+  bool IsTaskPending(TaskType task_type) const {
     return task_type == TaskType::kNormal ? normal_task_pending_
                                           : delayed_task_pending_;
   }
+
+ private:
+  class Task;
+  static constexpr double kDelayInSeconds = 10.0 / 1000.0;
+
   void SetTaskPending(TaskType task_type, bool value) {
     if (task_type == TaskType::kNormal) {
       normal_task_pending_ = value;
@@ -42,6 +45,7 @@ class IncrementalMarkingJob {
     }
   }
 
+  double scheduled_time_ = 0.0;
   bool normal_task_pending_ = false;
   bool delayed_task_pending_ = false;
 };
diff --git a/deps/v8/src/heap/incremental-marking.cc b/deps/v8/src/heap/incremental-marking.cc
index 29faad471c..76fdbc80c8 100644
--- a/deps/v8/src/heap/incremental-marking.cc
+++ b/deps/v8/src/heap/incremental-marking.cc
@@ -29,6 +29,7 @@
 #include "src/objects/transitions-inl.h"
 #include "src/objects/visitors.h"
 #include "src/tracing/trace-event.h"
+#include "src/utils/utils.h"
 
 namespace v8 {
 namespace internal {
@@ -50,17 +51,6 @@ IncrementalMarking::IncrementalMarking(Heap* heap,
     : heap_(heap),
       collector_(heap->mark_compact_collector()),
       weak_objects_(weak_objects),
-      initial_old_generation_size_(0),
-      bytes_marked_(0),
-      scheduled_bytes_to_mark_(0),
-      schedule_update_time_ms_(0),
-      bytes_marked_concurrently_(0),
-      is_compacting_(false),
-      should_hurry_(false),
-      was_activated_(false),
-      black_allocation_(false),
-      finalize_marking_completed_(false),
-      request_type_(NONE),
       new_generation_observer_(this, kYoungGenerationAllocatedThreshold),
       old_generation_observer_(this, kOldGenerationAllocatedThreshold) {
   SetState(STOPPED);
@@ -285,13 +275,13 @@ void IncrementalMarking::Start(GarbageCollectionReason gc_reason) {
   heap_->tracer()->NotifyIncrementalMarkingStart();
 
   start_time_ms_ = heap()->MonotonicallyIncreasingTimeInMs();
+  time_to_force_completion_ = 0.0;
   initial_old_generation_size_ = heap_->OldGenerationSizeOfObjects();
   old_generation_allocation_counter_ = heap_->OldGenerationAllocationCounter();
   bytes_marked_ = 0;
   scheduled_bytes_to_mark_ = 0;
   schedule_update_time_ms_ = start_time_ms_;
   bytes_marked_concurrently_ = 0;
-  should_hurry_ = false;
   was_activated_ = true;
 
   {
@@ -680,18 +670,25 @@ void IncrementalMarking::ProcessBlackAllocatedObject(HeapObject obj) {
   }
 }
 
-StepResult IncrementalMarking::EmbedderStep(double duration_ms) {
-  if (!ShouldDoEmbedderStep()) return StepResult::kNoImmediateWork;
+StepResult IncrementalMarking::EmbedderStep(double expected_duration_ms,
+                                            double* duration_ms) {
+  if (!ShouldDoEmbedderStep()) {
+    *duration_ms = 0.0;
+    return StepResult::kNoImmediateWork;
+  }
 
   constexpr size_t kObjectsToProcessBeforeInterrupt = 500;
 
   TRACE_GC(heap()->tracer(), GCTracer::Scope::MC_INCREMENTAL_EMBEDDER_TRACING);
-  double deadline = heap_->MonotonicallyIncreasingTimeInMs() + duration_ms;
+  LocalEmbedderHeapTracer* local_tracer = heap_->local_embedder_heap_tracer();
+  const double start = heap_->MonotonicallyIncreasingTimeInMs();
+  const double deadline = start + expected_duration_ms;
+  double current;
   bool empty_worklist;
+  bool remote_tracing_done = false;
   do {
     {
-      LocalEmbedderHeapTracer::ProcessingScope scope(
-          heap_->local_embedder_heap_tracer());
+      LocalEmbedderHeapTracer::ProcessingScope scope(local_tracer);
       HeapObject object;
       size_t cnt = 0;
       empty_worklist = true;
@@ -704,20 +701,17 @@ StepResult IncrementalMarking::EmbedderStep(double duration_ms) {
         }
       }
     }
-    heap_->local_embedder_heap_tracer()->Trace(deadline);
-  } while (!empty_worklist &&
-           (heap_->MonotonicallyIncreasingTimeInMs() < deadline));
-  heap_->local_embedder_heap_tracer()->SetEmbedderWorklistEmpty(empty_worklist);
-  return empty_worklist ? StepResult::kNoImmediateWork
-                        : StepResult::kMoreWorkRemaining;
+    remote_tracing_done = local_tracer->Trace(deadline);
+    current = heap_->MonotonicallyIncreasingTimeInMs();
+  } while (!empty_worklist && !remote_tracing_done && (current < deadline));
+  local_tracer->SetEmbedderWorklistEmpty(empty_worklist);
+  *duration_ms = current - start;
+  return (empty_worklist && remote_tracing_done)
+             ? StepResult::kNoImmediateWork
+             : StepResult::kMoreWorkRemaining;
 }
 
 void IncrementalMarking::Hurry() {
-  // A scavenge may have pushed new objects on the marking deque (due to black
-  // allocation) even in COMPLETE state. This may happen if scavenges are
-  // forced e.g. in tests. It should not happen when COMPLETE was set when
-  // incremental marking finished and a regular GC was triggered after that
-  // because should_hurry_ will force a full GC.
   if (!marking_worklists()->IsEmpty()) {
     double start = 0.0;
     if (FLAG_trace_incremental_marking) {
@@ -765,7 +759,6 @@ void IncrementalMarking::Stop() {
     }
   }
 
-  IncrementalMarking::set_should_hurry(false);
   heap_->isolate()->stack_guard()->ClearGC();
   SetState(STOPPED);
   is_compacting_ = false;
@@ -792,15 +785,66 @@ void IncrementalMarking::FinalizeMarking(CompletionAction action) {
   }
 }
 
+double IncrementalMarking::CurrentTimeToMarkingTask() const {
+  const double recorded_time_to_marking_task =
+      heap_->tracer()->AverageTimeToIncrementalMarkingTask();
+  const double current_time_to_marking_task =
+      incremental_marking_job_.CurrentTimeToTask(heap_);
+  if (recorded_time_to_marking_task == 0.0) return 0.0;
+  return Max(recorded_time_to_marking_task, current_time_to_marking_task);
+}
 
 void IncrementalMarking::MarkingComplete(CompletionAction action) {
+  // Allowed overshoot percantage of incremental marking walltime.
+  constexpr double kAllowedOvershoot = 0.1;
+  // Minimum overshoot in ms. This is used to allow moving away from stack when
+  // marking was fast.
+  constexpr double kMinOvershootMs = 50;
+
+  if (action == GC_VIA_STACK_GUARD) {
+    if (time_to_force_completion_ == 0.0) {
+      const double now = heap_->MonotonicallyIncreasingTimeInMs();
+      const double overshoot_ms =
+          Max(kMinOvershootMs, (now - start_time_ms_) * kAllowedOvershoot);
+      const double time_to_marking_task = CurrentTimeToMarkingTask();
+      if (time_to_marking_task == 0.0 || time_to_marking_task > overshoot_ms) {
+        if (FLAG_trace_incremental_marking) {
+          heap()->isolate()->PrintWithTimestamp(
+              "[IncrementalMarking] Not delaying marking completion. time to "
+              "task: %fms allowed overshoot: %fms\n",
+              time_to_marking_task, overshoot_ms);
+        }
+      } else {
+        time_to_force_completion_ = now + overshoot_ms;
+        if (FLAG_trace_incremental_marking) {
+          heap()->isolate()->PrintWithTimestamp(
+              "[IncrementalMarking] Delaying GC via stack guard. time to task: "
+              "%fms "
+              "allowed overshoot: %fms\n",
+              time_to_marking_task, overshoot_ms);
+        }
+        incremental_marking_job_.ScheduleTask(
+            heap(), IncrementalMarkingJob::TaskType::kNormal);
+        return;
+      }
+    }
+    if (heap()->MonotonicallyIncreasingTimeInMs() < time_to_force_completion_) {
+      if (FLAG_trace_incremental_marking) {
+        heap()->isolate()->PrintWithTimestamp(
+            "[IncrementalMarking] Delaying GC via stack guard. time left: "
+            "%fms\n",
+            time_to_force_completion_ -
+                heap_->MonotonicallyIncreasingTimeInMs());
+      }
+      return;
+    }
+  }
+
   SetState(COMPLETE);
   // We will set the stack guard to request a GC now.  This will mean the rest
   // of the GC gets performed as soon as possible (we can't do a GC here in a
   // record-write context).  If a few things get allocated between now and then
-  // that shouldn't make us do a scavenge and keep being incremental, so we set
-  // the should-hurry flag to indicate that there can't be much work left to do.
-  set_should_hurry(true);
+  // that shouldn't make us do a scavenge and keep being incremental.
   if (FLAG_trace_incremental_marking) {
     heap()->isolate()->PrintWithTimestamp(
         "[IncrementalMarking] Complete (normal).\n");
@@ -811,7 +855,6 @@ void IncrementalMarking::MarkingComplete(CompletionAction action) {
   }
 }
 
-
 void IncrementalMarking::Epilogue() {
   was_activated_ = false;
   finalize_marking_completed_ = false;
@@ -863,12 +906,11 @@ void IncrementalMarking::ScheduleBytesToMarkBasedOnTime(double time_ms) {
 
 namespace {
 StepResult CombineStepResults(StepResult a, StepResult b) {
+  DCHECK_NE(StepResult::kWaitingForFinalization, a);
+  DCHECK_NE(StepResult::kWaitingForFinalization, b);
   if (a == StepResult::kMoreWorkRemaining ||
       b == StepResult::kMoreWorkRemaining)
     return StepResult::kMoreWorkRemaining;
-  if (a == StepResult::kWaitingForFinalization ||
-      b == StepResult::kWaitingForFinalization)
-    return StepResult::kWaitingForFinalization;
   return StepResult::kNoImmediateWork;
 }
 }  // anonymous namespace
@@ -884,22 +926,7 @@ StepResult IncrementalMarking::AdvanceWithDeadline(
 
   ScheduleBytesToMarkBasedOnTime(heap()->MonotonicallyIncreasingTimeInMs());
   FastForwardScheduleIfCloseToFinalization();
-
-  double remaining_time_in_ms = 0.0;
-  StepResult result;
-  do {
-    StepResult v8_result =
-        V8Step(kStepSizeInMs / 2, completion_action, step_origin);
-    remaining_time_in_ms =
-        deadline_in_ms - heap()->MonotonicallyIncreasingTimeInMs();
-    StepResult embedder_result =
-        EmbedderStep(Min(kStepSizeInMs, remaining_time_in_ms));
-    result = CombineStepResults(v8_result, embedder_result);
-    remaining_time_in_ms =
-        deadline_in_ms - heap()->MonotonicallyIncreasingTimeInMs();
-  } while (remaining_time_in_ms >= kStepSizeInMs &&
-           result == StepResult::kMoreWorkRemaining);
-  return result;
+  return Step(kStepSizeInMs, completion_action, step_origin);
 }
 
 void IncrementalMarking::FinalizeSweeping() {
@@ -1015,13 +1042,12 @@ void IncrementalMarking::AdvanceOnAllocation() {
   TRACE_EVENT0("v8", "V8.GCIncrementalMarking");
   TRACE_GC(heap_->tracer(), GCTracer::Scope::MC_INCREMENTAL);
   ScheduleBytesToMarkBasedOnAllocation();
-  V8Step(kMaxStepSizeInMs, GC_VIA_STACK_GUARD, StepOrigin::kV8);
+  Step(kMaxStepSizeInMs, GC_VIA_STACK_GUARD, StepOrigin::kV8);
 }
 
-StepResult IncrementalMarking::V8Step(double max_step_size_in_ms,
-                                      CompletionAction action,
-                                      StepOrigin step_origin) {
-  StepResult result = StepResult::kMoreWorkRemaining;
+StepResult IncrementalMarking::Step(double max_step_size_in_ms,
+                                    CompletionAction action,
+                                    StepOrigin step_origin) {
   double start = heap_->MonotonicallyIncreasingTimeInMs();
 
   if (state_ == SWEEPING) {
@@ -1029,7 +1055,11 @@ StepResult IncrementalMarking::V8Step(double max_step_size_in_ms,
     FinalizeSweeping();
   }
 
-  size_t bytes_processed = 0, bytes_to_process = 0;
+  StepResult combined_result = StepResult::kMoreWorkRemaining;
+  size_t bytes_to_process = 0;
+  size_t v8_bytes_processed = 0;
+  double embedder_duration = 0.0;
+  double embedder_deadline = 0.0;
   if (state_ == MARKING) {
     if (FLAG_concurrent_marking) {
       heap_->new_space()->ResetOriginalTop();
@@ -1054,34 +1084,42 @@ StepResult IncrementalMarking::V8Step(double max_step_size_in_ms,
     }
     // The first step after Scavenge will see many allocated bytes.
     // Cap the step size to distribute the marking work more uniformly.
+    const double marking_speed =
+        heap()->tracer()->IncrementalMarkingSpeedInBytesPerMillisecond();
     size_t max_step_size = GCIdleTimeHandler::EstimateMarkingStepSize(
-        max_step_size_in_ms,
-        heap()->tracer()->IncrementalMarkingSpeedInBytesPerMillisecond());
+        max_step_size_in_ms, marking_speed);
     bytes_to_process = Min(ComputeStepSizeInBytes(step_origin), max_step_size);
-    if (bytes_to_process == 0) {
-      result = StepResult::kNoImmediateWork;
+    bytes_to_process = Max(bytes_to_process, kMinStepSizeInBytes);
+
+    // Perform a single V8 and a single embedder step. In case both have been
+    // observed as empty back to back, we can finalize.
+    //
+    // This ignores that case where the embedder finds new V8-side objects. The
+    // assumption is that large graphs are well connected and can mostly be
+    // processed on their own. For small graphs, helping is not necessary.
+    v8_bytes_processed = collector_->ProcessMarkingWorklist(bytes_to_process);
+    StepResult v8_result = marking_worklists()->IsEmpty()
+                               ? StepResult::kNoImmediateWork
+                               : StepResult::kMoreWorkRemaining;
+    StepResult embedder_result = StepResult::kNoImmediateWork;
+    if (heap_->local_embedder_heap_tracer()->InUse()) {
+      embedder_deadline =
+          Min(max_step_size_in_ms,
+              static_cast<double>(bytes_to_process) / marking_speed);
+      embedder_result = EmbedderStep(embedder_deadline, &embedder_duration);
     }
-
-    bytes_processed = collector_->ProcessMarkingWorklist(
-        Max(bytes_to_process, kMinStepSizeInBytes));
-
-    bytes_marked_ += bytes_processed;
-
-    if (marking_worklists()->IsEmpty()) {
-      result = StepResult::kNoImmediateWork;
-      if (heap_->local_embedder_heap_tracer()
-              ->ShouldFinalizeIncrementalMarking()) {
-        if (!finalize_marking_completed_) {
-          FinalizeMarking(action);
-          FastForwardSchedule();
-          result = StepResult::kWaitingForFinalization;
-          incremental_marking_job()->Start(heap_);
-        } else {
-          MarkingComplete(action);
-          result = StepResult::kWaitingForFinalization;
-        }
+    bytes_marked_ += v8_bytes_processed;
+    combined_result = CombineStepResults(v8_result, embedder_result);
+
+    if (combined_result == StepResult::kNoImmediateWork) {
+      if (!finalize_marking_completed_) {
+        FinalizeMarking(action);
+        FastForwardSchedule();
+        combined_result = StepResult::kWaitingForFinalization;
+        incremental_marking_job()->Start(heap_);
       } else {
-        heap_->local_embedder_heap_tracer()->NotifyV8MarkingWorklistWasEmpty();
+        MarkingComplete(action);
+        combined_result = StepResult::kWaitingForFinalization;
       }
     }
     if (FLAG_concurrent_marking) {
@@ -1089,22 +1127,22 @@ StepResult IncrementalMarking::V8Step(double max_step_size_in_ms,
       heap_->concurrent_marking()->RescheduleTasksIfNeeded();
     }
   }
-
-  double end = heap_->MonotonicallyIncreasingTimeInMs();
-  double duration = (end - start);
   if (state_ == MARKING) {
-    // Note that we report zero bytes here when sweeping was in progress or
-    // when we just started incremental marking. In these cases we did not
-    // process the marking deque.
-    heap_->tracer()->AddIncrementalMarkingStep(duration, bytes_processed);
+    // Note that we do not report any marked by in case of finishing sweeping as
+    // we did not process the marking worklist.
+    const double v8_duration =
+        heap_->MonotonicallyIncreasingTimeInMs() - start - embedder_duration;
+    heap_->tracer()->AddIncrementalMarkingStep(v8_duration, v8_bytes_processed);
   }
   if (FLAG_trace_incremental_marking) {
     heap_->isolate()->PrintWithTimestamp(
-        "[IncrementalMarking] Step %s %zuKB (%zuKB) in %.1f\n",
+        "[IncrementalMarking] Step %s V8: %zuKB (%zuKB), embedder: %fms (%fms) "
+        "in %.1f\n",
         step_origin == StepOrigin::kV8 ? "in v8" : "in task",
-        bytes_processed / KB, bytes_to_process / KB, duration);
+        v8_bytes_processed / KB, bytes_to_process / KB, embedder_duration,
+        embedder_deadline, heap_->MonotonicallyIncreasingTimeInMs() - start);
   }
-  return result;
+  return combined_result;
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/incremental-marking.h b/deps/v8/src/heap/incremental-marking.h
index bd2b93efe2..04000be352 100644
--- a/deps/v8/src/heap/incremental-marking.h
+++ b/deps/v8/src/heap/incremental-marking.h
@@ -26,7 +26,7 @@ enum class StepResult {
   kWaitingForFinalization
 };
 
-class V8_EXPORT_PRIVATE IncrementalMarking {
+class V8_EXPORT_PRIVATE IncrementalMarking final {
  public:
   enum State { STOPPED, SWEEPING, MARKING, COMPLETE };
 
@@ -105,9 +105,6 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
     return state_;
   }
 
-  bool should_hurry() const { return should_hurry_; }
-  void set_should_hurry(bool val) { should_hurry_ = val; }
-
   bool finalize_marking_completed() const {
     return finalize_marking_completed_;
   }
@@ -172,11 +169,11 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
 
   void FinalizeSweeping();
 
-  StepResult V8Step(double max_step_size_in_ms, CompletionAction action,
-                    StepOrigin step_origin);
+  StepResult Step(double max_step_size_in_ms, CompletionAction action,
+                  StepOrigin step_origin);
 
   bool ShouldDoEmbedderStep();
-  StepResult EmbedderStep(double duration);
+  StepResult EmbedderStep(double expected_duration_ms, double* duration_ms);
 
   V8_INLINE void RestartIfNotMarking();
 
@@ -301,32 +298,34 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
     heap_->SetIsMarkingFlag(s >= MARKING);
   }
 
+  double CurrentTimeToMarkingTask() const;
+
   Heap* const heap_;
   MarkCompactCollector* const collector_;
   WeakObjects* weak_objects_;
 
-  double start_time_ms_;
-  size_t initial_old_generation_size_;
-  size_t old_generation_allocation_counter_;
-  size_t bytes_marked_;
-  size_t scheduled_bytes_to_mark_;
-  double schedule_update_time_ms_;
+  double start_time_ms_ = 0.0;
+  double time_to_force_completion_ = 0.0;
+  size_t initial_old_generation_size_ = 0;
+  size_t old_generation_allocation_counter_ = 0;
+  size_t bytes_marked_ = 0;
+  size_t scheduled_bytes_to_mark_ = 0;
+  double schedule_update_time_ms_ = 0.0;
   // A sample of concurrent_marking()->TotalMarkedBytes() at the last
   // incremental marking step. It is used for updating
   // bytes_marked_ahead_of_schedule_ with contribution of concurrent marking.
-  size_t bytes_marked_concurrently_;
+  size_t bytes_marked_concurrently_ = 0;
 
   // Must use SetState() above to update state_
   State state_;
 
-  bool is_compacting_;
-  bool should_hurry_;
-  bool was_activated_;
-  bool black_allocation_;
-  bool finalize_marking_completed_;
+  bool is_compacting_ = false;
+  bool was_activated_ = false;
+  bool black_allocation_ = false;
+  bool finalize_marking_completed_ = false;
   IncrementalMarkingJob incremental_marking_job_;
 
-  GCRequestType request_type_;
+  GCRequestType request_type_ = NONE;
 
   Observer new_generation_observer_;
   Observer old_generation_observer_;
diff --git a/deps/v8/src/heap/local-heap.cc b/deps/v8/src/heap/local-heap.cc
new file mode 100644
index 0000000000..392b343236
--- /dev/null
+++ b/deps/v8/src/heap/local-heap.cc
@@ -0,0 +1,71 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/local-heap.h"
+#include "src/handles/local-handles.h"
+#include "src/heap/heap.h"
+#include "src/heap/safepoint.h"
+
+namespace v8 {
+namespace internal {
+
+LocalHeap::LocalHeap(Heap* heap)
+    : heap_(heap),
+      state_(ThreadState::Running),
+      safepoint_requested_(false),
+      prev_(nullptr),
+      next_(nullptr),
+      handles_(new LocalHandles) {
+  heap_->safepoint()->AddLocalHeap(this);
+}
+
+LocalHeap::~LocalHeap() {
+  // Park thread since removing the local heap could block.
+  EnsureParkedBeforeDestruction();
+
+  heap_->safepoint()->RemoveLocalHeap(this);
+}
+
+void LocalHeap::Park() {
+  base::MutexGuard guard(&state_mutex_);
+  CHECK(state_ == ThreadState::Running);
+  state_ = ThreadState::Parked;
+  state_change_.NotifyAll();
+}
+
+void LocalHeap::Unpark() {
+  base::MutexGuard guard(&state_mutex_);
+  CHECK(state_ == ThreadState::Parked);
+  state_ = ThreadState::Running;
+}
+
+void LocalHeap::EnsureParkedBeforeDestruction() {
+  base::MutexGuard guard(&state_mutex_);
+  state_ = ThreadState::Parked;
+  state_change_.NotifyAll();
+}
+
+void LocalHeap::RequestSafepoint() {
+  safepoint_requested_.store(true, std::memory_order_relaxed);
+}
+
+bool LocalHeap::IsSafepointRequested() {
+  return safepoint_requested_.load(std::memory_order_relaxed);
+}
+
+void LocalHeap::Safepoint() {
+  if (IsSafepointRequested()) {
+    ClearSafepointRequested();
+    EnterSafepoint();
+  }
+}
+
+void LocalHeap::ClearSafepointRequested() {
+  safepoint_requested_.store(false, std::memory_order_relaxed);
+}
+
+void LocalHeap::EnterSafepoint() { heap_->safepoint()->EnterFromThread(this); }
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/heap/local-heap.h b/deps/v8/src/heap/local-heap.h
new file mode 100644
index 0000000000..a6eed1d928
--- /dev/null
+++ b/deps/v8/src/heap/local-heap.h
@@ -0,0 +1,89 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_LOCAL_HEAP_H_
+#define V8_HEAP_LOCAL_HEAP_H_
+
+#include <atomic>
+#include <memory>
+
+#include "src/base/platform/condition-variable.h"
+#include "src/base/platform/mutex.h"
+
+namespace v8 {
+namespace internal {
+
+class Heap;
+class Safepoint;
+class LocalHandles;
+
+class LocalHeap {
+ public:
+  V8_EXPORT_PRIVATE explicit LocalHeap(Heap* heap);
+  V8_EXPORT_PRIVATE ~LocalHeap();
+
+  // Invoked by main thread to signal this thread that it needs to halt in a
+  // safepoint.
+  void RequestSafepoint();
+
+  // Frequently invoked by local thread to check whether safepoint was requested
+  // from the main thread.
+  V8_EXPORT_PRIVATE void Safepoint();
+
+  LocalHandles* handles() { return handles_.get(); }
+
+ private:
+  enum class ThreadState {
+    // Threads in this state need to be stopped in a safepoint.
+    Running,
+    // Thread was parked, which means that the thread is not allowed to access
+    // or manipulate the heap in any way.
+    Parked,
+    // Thread was stopped in a safepoint.
+    Safepoint
+  };
+
+  V8_EXPORT_PRIVATE void Park();
+  V8_EXPORT_PRIVATE void Unpark();
+  void EnsureParkedBeforeDestruction();
+
+  bool IsSafepointRequested();
+  void ClearSafepointRequested();
+
+  void EnterSafepoint();
+
+  Heap* heap_;
+
+  base::Mutex state_mutex_;
+  base::ConditionVariable state_change_;
+  ThreadState state_;
+
+  std::atomic<bool> safepoint_requested_;
+
+  LocalHeap* prev_;
+  LocalHeap* next_;
+
+  std::unique_ptr<LocalHandles> handles_;
+
+  friend class Heap;
+  friend class Safepoint;
+  friend class ParkedScope;
+};
+
+class ParkedScope {
+ public:
+  explicit ParkedScope(LocalHeap* local_heap) : local_heap_(local_heap) {
+    local_heap_->Park();
+  }
+
+  ~ParkedScope() { local_heap_->Unpark(); }
+
+ private:
+  LocalHeap* local_heap_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_LOCAL_HEAP_H_
diff --git a/deps/v8/src/heap/mark-compact-inl.h b/deps/v8/src/heap/mark-compact-inl.h
index 3c90344e68..295982beb5 100644
--- a/deps/v8/src/heap/mark-compact-inl.h
+++ b/deps/v8/src/heap/mark-compact-inl.h
@@ -205,8 +205,11 @@ void LiveObjectRange<mode>::iterator::AdvanceToNextValidObject() {
         // make sure that we skip all set bits in the black area until the
         // object ends.
         HeapObject black_object = HeapObject::FromAddress(addr);
-        map = Map::cast(ObjectSlot(addr).Acquire_Load());
+        Object map_object = ObjectSlot(addr).Acquire_Load();
+        CHECK(map_object.IsMap());
+        map = Map::cast(map_object);
         size = black_object.SizeFromMap(map);
+        CHECK_LE(addr + size, chunk_->area_end());
         Address end = addr + size - kTaggedSize;
         // One word filler objects do not borrow the second mark bit. We have
         // to jump over the advancing and clearing part.
@@ -232,9 +235,12 @@ void LiveObjectRange<mode>::iterator::AdvanceToNextValidObject() {
           object = black_object;
         }
       } else if ((mode == kGreyObjects || mode == kAllLiveObjects)) {
-        map = Map::cast(ObjectSlot(addr).Acquire_Load());
+        Object map_object = ObjectSlot(addr).Acquire_Load();
+        CHECK(map_object.IsMap());
+        map = Map::cast(map_object);
         object = HeapObject::FromAddress(addr);
         size = object.SizeFromMap(map);
+        CHECK_LE(addr + size, chunk_->area_end());
       }
 
       // We found a live object.
diff --git a/deps/v8/src/heap/mark-compact.cc b/deps/v8/src/heap/mark-compact.cc
index 2113f89ba6..7a87adb5f6 100644
--- a/deps/v8/src/heap/mark-compact.cc
+++ b/deps/v8/src/heap/mark-compact.cc
@@ -387,8 +387,9 @@ int NumberOfAvailableCores() {
 
 int MarkCompactCollectorBase::NumberOfParallelCompactionTasks(int pages) {
   DCHECK_GT(pages, 0);
-  int tasks =
-      FLAG_parallel_compaction ? Min(NumberOfAvailableCores(), pages) : 1;
+  int tasks = FLAG_parallel_compaction ? Min(NumberOfAvailableCores(),
+                                             pages / (MB / Page::kPageSize) + 1)
+                                       : 1;
   if (!heap_->CanExpandOldGeneration(
           static_cast<size_t>(tasks * Page::kPageSize))) {
     // Optimize for memory usage near the heap limit.
@@ -2217,7 +2218,7 @@ void MarkCompactCollector::FlushBytecodeFromSFI(
 
   // Initialize the uncompiled data.
   UncompiledData uncompiled_data = UncompiledData::cast(compiled_data);
-  uncompiled_data.Init(
+  uncompiled_data.InitAfterBytecodeFlush(
       inferred_name, start_position, end_position,
       [](HeapObject object, ObjectSlot slot, HeapObject target) {
         RecordSlot(object, slot, target);
@@ -2493,18 +2494,18 @@ void MarkCompactCollector::ClearJSWeakRefs() {
     if (!non_atomic_marking_state()->IsBlackOrGrey(target)) {
       DCHECK(!target.IsUndefined());
       // The value of the WeakCell is dead.
-      JSFinalizationGroup finalization_group =
-          JSFinalizationGroup::cast(weak_cell.finalization_group());
-      if (!finalization_group.scheduled_for_cleanup()) {
-        heap()->AddDirtyJSFinalizationGroup(finalization_group,
-                                            gc_notify_updated_slot);
+      JSFinalizationRegistry finalization_registry =
+          JSFinalizationRegistry::cast(weak_cell.finalization_registry());
+      if (!finalization_registry.scheduled_for_cleanup()) {
+        heap()->EnqueueDirtyJSFinalizationRegistry(finalization_registry,
+                                                   gc_notify_updated_slot);
       }
-      // We're modifying the pointers in WeakCell and JSFinalizationGroup during
-      // GC; thus we need to record the slots it writes. The normal write
+      // We're modifying the pointers in WeakCell and JSFinalizationRegistry
+      // during GC; thus we need to record the slots it writes. The normal write
       // barrier is not enough, since it's disabled before GC.
       weak_cell.Nullify(isolate(), gc_notify_updated_slot);
-      DCHECK(finalization_group.NeedsCleanup());
-      DCHECK(finalization_group.scheduled_for_cleanup());
+      DCHECK(finalization_registry.NeedsCleanup());
+      DCHECK(finalization_registry.scheduled_for_cleanup());
     } else {
       // The value of the WeakCell is alive.
       ObjectSlot slot = weak_cell.RawField(WeakCell::kTargetOffset);
@@ -2520,9 +2521,9 @@ void MarkCompactCollector::ClearJSWeakRefs() {
       // WeakCell. Like above, we're modifying pointers during GC, so record the
       // slots.
       HeapObject undefined = ReadOnlyRoots(isolate()).undefined_value();
-      JSFinalizationGroup finalization_group =
-          JSFinalizationGroup::cast(weak_cell.finalization_group());
-      finalization_group.RemoveUnregisterToken(
+      JSFinalizationRegistry finalization_registry =
+          JSFinalizationRegistry::cast(weak_cell.finalization_registry());
+      finalization_registry.RemoveUnregisterToken(
           JSReceiver::cast(unregister_token), isolate(),
           [undefined](WeakCell matched_cell) {
             matched_cell.set_unregister_token(undefined);
@@ -2534,6 +2535,9 @@ void MarkCompactCollector::ClearJSWeakRefs() {
       RecordSlot(weak_cell, slot, HeapObject::cast(*slot));
     }
   }
+  if (!isolate()->host_cleanup_finalization_group_callback()) {
+    heap()->PostFinalizationRegistryCleanupTaskIfNeeded();
+  }
 }
 
 void MarkCompactCollector::AbortWeakObjects() {
@@ -2936,7 +2940,7 @@ void Evacuator::EvacuatePage(MemoryChunk* chunk) {
   intptr_t saved_live_bytes = 0;
   double evacuation_time = 0.0;
   {
-    AlwaysAllocateScope always_allocate(heap()->isolate());
+    AlwaysAllocateScope always_allocate(heap());
     TimedScope timed_scope(&evacuation_time);
     RawEvacuatePage(chunk, &saved_live_bytes);
   }
diff --git a/deps/v8/src/heap/marking-worklist.h b/deps/v8/src/heap/marking-worklist.h
index ffa2a15fa1..d4659b0ac7 100644
--- a/deps/v8/src/heap/marking-worklist.h
+++ b/deps/v8/src/heap/marking-worklist.h
@@ -81,6 +81,10 @@ class V8_EXPORT_PRIVATE MarkingWorklistsHolder {
     on_hold_.Update(callback);
     embedder_.Update(callback);
     for (auto cw : context_worklists_) {
+      if (cw.context == kSharedContext) {
+        // The shared context was updated above.
+        continue;
+      }
       cw.worklist->Update(callback);
     }
   }
diff --git a/deps/v8/src/heap/memory-measurement.cc b/deps/v8/src/heap/memory-measurement.cc
index 3d2c794ca2..2a59ac5a4d 100644
--- a/deps/v8/src/heap/memory-measurement.cc
+++ b/deps/v8/src/heap/memory-measurement.cc
@@ -13,6 +13,7 @@
 #include "src/heap/factory.h"
 #include "src/heap/incremental-marking.h"
 #include "src/heap/marking-worklist.h"
+#include "src/logging/counters.h"
 #include "src/objects/js-promise-inl.h"
 #include "src/objects/js-promise.h"
 #include "src/tasks/task-utils.h"
@@ -178,8 +179,12 @@ bool MemoryMeasurement::EnqueueRequest(
   }
   Handle<WeakFixedArray> global_weak_contexts =
       isolate_->global_handles()->Create(*weak_contexts);
-  Request request = {std::move(delegate), global_weak_contexts,
-                     std::vector<size_t>(length), 0u};
+  Request request = {std::move(delegate),
+                     global_weak_contexts,
+                     std::vector<size_t>(length),
+                     0u,
+                     {}};
+  request.timer.Start();
   received_.push_back(std::move(request));
   ScheduleGCTask(execution);
   return true;
@@ -303,6 +308,8 @@ void MemoryMeasurement::ReportResults() {
       sizes.push_back(std::make_pair(context, request.sizes[i]));
     }
     request.delegate->MeasurementComplete(sizes, request.shared);
+    isolate_->counters()->measure_memory_delay_ms()->AddSample(
+        static_cast<int>(request.timer.Elapsed().InMilliseconds()));
   }
 }
 
diff --git a/deps/v8/src/heap/memory-measurement.h b/deps/v8/src/heap/memory-measurement.h
index eb12cb152d..d72dd1eba9 100644
--- a/deps/v8/src/heap/memory-measurement.h
+++ b/deps/v8/src/heap/memory-measurement.h
@@ -8,6 +8,7 @@
 #include <list>
 #include <unordered_map>
 
+#include "src/base/platform/elapsed-timer.h"
 #include "src/common/globals.h"
 #include "src/objects/contexts.h"
 #include "src/objects/map.h"
@@ -34,12 +35,13 @@ class MemoryMeasurement {
       Handle<JSPromise> promise, v8::MeasureMemoryMode mode);
 
  private:
-  static const int kGCTaskDelayInSeconds = 60;
+  static const int kGCTaskDelayInSeconds = 10;
   struct Request {
     std::unique_ptr<v8::MeasureMemoryDelegate> delegate;
     Handle<WeakFixedArray> contexts;
     std::vector<size_t> sizes;
     size_t shared;
+    base::ElapsedTimer timer;
   };
   void ScheduleReportingTask();
   void ReportResults();
diff --git a/deps/v8/src/heap/object-stats.h b/deps/v8/src/heap/object-stats.h
index 28ef967c5c..fe27095ee5 100644
--- a/deps/v8/src/heap/object-stats.h
+++ b/deps/v8/src/heap/object-stats.h
@@ -94,7 +94,7 @@ class ObjectStats {
  public:
   static const size_t kNoOverAllocation = 0;
 
-  explicit ObjectStats(Heap* heap) : heap_(heap) { ClearObjectStats(); }
+  explicit ObjectStats(Heap* heap) : heap_(heap) { ClearObjectStats(true); }
 
   // See description on VIRTUAL_INSTANCE_TYPE_LIST.
   enum VirtualInstanceType {
diff --git a/deps/v8/src/heap/objects-visiting-inl.h b/deps/v8/src/heap/objects-visiting-inl.h
index d4d6d9375c..03df9a175d 100644
--- a/deps/v8/src/heap/objects-visiting-inl.h
+++ b/deps/v8/src/heap/objects-visiting-inl.h
@@ -18,6 +18,7 @@
 #include "src/objects/oddball.h"
 #include "src/objects/ordered-hash-table.h"
 #include "src/wasm/wasm-objects.h"
+#include "torque-generated/objects-body-descriptors-tq-inl.h"
 
 namespace v8 {
 namespace internal {
@@ -43,6 +44,7 @@ ResultType HeapVisitor<ResultType, ConcreteVisitor>::Visit(Map map,
     return visitor->Visit##TypeName( \
         map, ConcreteVisitor::template Cast<TypeName>(object));
     TYPED_VISITOR_ID_LIST(CASE)
+    TORQUE_VISITOR_ID_LIST(CASE)
 #undef CASE
     case kVisitShortcutCandidate:
       return visitor->VisitShortcutCandidate(
@@ -96,6 +98,7 @@ void HeapVisitor<ResultType, ConcreteVisitor>::VisitMapPointer(
     return static_cast<ResultType>(size);                                      \
   }
 TYPED_VISITOR_ID_LIST(VISIT)
+TORQUE_VISITOR_ID_LIST(VISIT)
 #undef VISIT
 
 template <typename ResultType, typename ConcreteVisitor>
diff --git a/deps/v8/src/heap/objects-visiting.cc b/deps/v8/src/heap/objects-visiting.cc
index ec494715ba..218a7a03c9 100644
--- a/deps/v8/src/heap/objects-visiting.cc
+++ b/deps/v8/src/heap/objects-visiting.cc
@@ -185,10 +185,37 @@ struct WeakListVisitor<AllocationSite> {
   static void VisitPhantomObject(Heap*, AllocationSite) {}
 };
 
+template <>
+struct WeakListVisitor<JSFinalizationRegistry> {
+  static void SetWeakNext(JSFinalizationRegistry obj, Object next) {
+    obj.set_next_dirty(next, UPDATE_WEAK_WRITE_BARRIER);
+  }
+
+  static Object WeakNext(JSFinalizationRegistry obj) {
+    return obj.next_dirty();
+  }
+
+  static HeapObject WeakNextHolder(JSFinalizationRegistry obj) { return obj; }
+
+  static int WeakNextOffset() {
+    return JSFinalizationRegistry::kNextDirtyOffset;
+  }
+
+  static void VisitLiveObject(Heap* heap, JSFinalizationRegistry obj,
+                              WeakObjectRetainer*) {
+    heap->set_dirty_js_finalization_registries_list_tail(obj);
+  }
+
+  static void VisitPhantomObject(Heap*, JSFinalizationRegistry) {}
+};
+
 template Object VisitWeakList<Context>(Heap* heap, Object list,
                                        WeakObjectRetainer* retainer);
 
 template Object VisitWeakList<AllocationSite>(Heap* heap, Object list,
                                               WeakObjectRetainer* retainer);
+
+template Object VisitWeakList<JSFinalizationRegistry>(
+    Heap* heap, Object list, WeakObjectRetainer* retainer);
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/objects-visiting.h b/deps/v8/src/heap/objects-visiting.h
index d197bb4fd2..ea70f36ac0 100644
--- a/deps/v8/src/heap/objects-visiting.h
+++ b/deps/v8/src/heap/objects-visiting.h
@@ -23,6 +23,7 @@ namespace internal {
   V(CodeDataContainer)                 \
   V(ConsString)                        \
   V(Context)                           \
+  V(CoverageInfo)                      \
   V(DataHandler)                       \
   V(DescriptorArray)                   \
   V(EmbedderDataArray)                 \
@@ -67,6 +68,7 @@ namespace internal {
 
 #define FORWARD_DECLARE(TypeName) class TypeName;
 TYPED_VISITOR_ID_LIST(FORWARD_DECLARE)
+TORQUE_VISITOR_ID_LIST(FORWARD_DECLARE)
 #undef FORWARD_DECLARE
 
 // The base class for visitors that need to dispatch on object type. The default
@@ -102,6 +104,7 @@ class HeapVisitor : public ObjectVisitor {
 #define VISIT(TypeName) \
   V8_INLINE ResultType Visit##TypeName(Map map, TypeName object);
   TYPED_VISITOR_ID_LIST(VISIT)
+  TORQUE_VISITOR_ID_LIST(VISIT)
 #undef VISIT
   V8_INLINE ResultType VisitShortcutCandidate(Map map, ConsString object);
   V8_INLINE ResultType VisitDataObject(Map map, HeapObject object);
@@ -143,8 +146,6 @@ class WeakObjectRetainer;
 // access the next-element pointers.
 template <class T>
 Object VisitWeakList(Heap* heap, Object list, WeakObjectRetainer* retainer);
-template <class T>
-Object VisitWeakList2(Heap* heap, Object list, WeakObjectRetainer* retainer);
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/heap/off-thread-factory-inl.h b/deps/v8/src/heap/off-thread-factory-inl.h
index 8352565ad5..75f35d94c4 100644
--- a/deps/v8/src/heap/off-thread-factory-inl.h
+++ b/deps/v8/src/heap/off-thread-factory-inl.h
@@ -7,18 +7,29 @@
 
 #include "src/heap/off-thread-factory.h"
 
+#include "src/heap/factory-base-inl.h"
 #include "src/roots/roots-inl.h"
 
 namespace v8 {
 namespace internal {
 
-#define ROOT_ACCESSOR(Type, name, CamelName)                \
-  OffThreadHandle<Type> OffThreadFactory::name() {          \
-    return OffThreadHandle<Type>(read_only_roots().name()); \
+#define ROOT_ACCESSOR(Type, name, CamelName)  \
+  Handle<Type> OffThreadFactory::name() {     \
+    return read_only_roots().name##_handle(); \
   }
 READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
+#define ACCESSOR_INFO_ACCESSOR(Type, name, CamelName)                          \
+  Handle<Type> OffThreadFactory::name() {                                      \
+    /* Do a bit of handle location magic to cast the Handle without having */  \
+    /* to pull in Type::cast. We know the type is right by construction.   */  \
+    return Handle<Type>(                                                       \
+        isolate()->isolate_->root_handle(RootIndex::k##CamelName).location()); \
+  }
+ACCESSOR_INFO_ROOT_LIST(ACCESSOR_INFO_ACCESSOR)
+#undef ACCESSOR_INFO_ACCESSOR
+
 #endif  // V8_HEAP_OFF_THREAD_FACTORY_INL_H_
 
 }  // namespace internal
diff --git a/deps/v8/src/heap/off-thread-factory.cc b/deps/v8/src/heap/off-thread-factory.cc
index 66aca9261c..d8cab5df69 100644
--- a/deps/v8/src/heap/off-thread-factory.cc
+++ b/deps/v8/src/heap/off-thread-factory.cc
@@ -16,10 +16,12 @@
 #include "src/objects/heap-object.h"
 #include "src/objects/map-inl.h"
 #include "src/objects/objects-body-descriptors-inl.h"
+#include "src/objects/shared-function-info.h"
 #include "src/objects/string.h"
 #include "src/objects/visitors.h"
 #include "src/roots/roots-inl.h"
 #include "src/roots/roots.h"
+#include "src/tracing/trace-event.h"
 
 namespace v8 {
 namespace internal {
@@ -106,98 +108,138 @@ void OffThreadFactory::Publish(Isolate* isolate) {
   // structure off-thread and merge it into the current handle scope all in one
   // go (DeferredHandles maybe?).
   std::vector<Handle<HeapObject>> heap_object_handles;
-  heap_object_handles.reserve(string_slots_.size());
-  for (RelativeSlot relative_slot : string_slots_) {
-    // TODO(leszeks): Group slots in the same parent object to avoid creating
-    // multiple duplicate handles.
-    heap_object_handles.push_back(handle(
-        HeapObject::cast(Object(relative_slot.object_address)), isolate));
-
-    // De-internalize the string so that we can re-internalize it later.
-    ObjectSlot slot(relative_slot.object_address + relative_slot.slot_offset);
-    String string = String::cast(slot.Acquire_Load());
-    bool one_byte = string.IsOneByteRepresentation();
-    Map map = one_byte ? read_only_roots().one_byte_string_map()
-                       : read_only_roots().string_map();
-    string.set_map_no_write_barrier(map);
+  std::vector<Handle<Script>> script_handles;
+  {
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                 "V8.OffThreadFinalization.Publish.CollectHandles");
+    heap_object_handles.reserve(string_slots_.size());
+    for (RelativeSlot relative_slot : string_slots_) {
+      // TODO(leszeks): Group slots in the same parent object to avoid creating
+      // multiple duplicate handles.
+      heap_object_handles.push_back(handle(
+          HeapObject::cast(Object(relative_slot.object_address)), isolate));
+
+      // De-internalize the string so that we can re-internalize it later.
+      ObjectSlot slot(relative_slot.object_address + relative_slot.slot_offset);
+      String string = String::cast(slot.Acquire_Load());
+      bool one_byte = string.IsOneByteRepresentation();
+      Map map = one_byte ? read_only_roots().one_byte_string_map()
+                         : read_only_roots().string_map();
+      string.set_map_no_write_barrier(map);
+    }
+
+    script_handles.reserve(script_list_.size());
+    for (Script script : script_list_) {
+      script_handles.push_back(handle(script, isolate));
+    }
   }
 
   // Then merge the spaces. At this point, we are allowed to point between (no
   // longer) off-thread pages and main-thread heap pages, and objects in the
   // previously off-thread page can move.
-  isolate->heap()->old_space()->MergeLocalSpace(&space_);
-  isolate->heap()->lo_space()->MergeOffThreadSpace(&lo_space_);
+  {
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                 "V8.OffThreadFinalization.Publish.Merge");
+    isolate->heap()->old_space()->MergeLocalSpace(&space_);
+    isolate->heap()->lo_space()->MergeOffThreadSpace(&lo_space_);
+  }
 
   // Iterate the string slots, as an offset from the holders we have handles to.
-  for (size_t i = 0; i < string_slots_.size(); ++i) {
-    int slot_offset = string_slots_[i].slot_offset;
-
-    // There's currently no cases where the holder object could have been
-    // resized.
-    DCHECK_LT(slot_offset, heap_object_handles[i]->Size());
-
-    ObjectSlot slot(heap_object_handles[i]->ptr() + slot_offset);
-
-    String string = String::cast(slot.Acquire_Load());
-    if (string.IsThinString()) {
-      // We may have already internalized this string via another slot.
-      slot.Release_Store(ThinString::cast(string).GetUnderlying());
-    } else {
-      HandleScope handle_scope(isolate);
-
-      Handle<String> string_handle = handle(string, isolate);
-      Handle<String> internalized_string =
-          isolate->factory()->InternalizeString(string_handle);
-
-      // Recalculate the slot in case there was GC and the holder moved.
-      ObjectSlot slot(heap_object_handles[i]->ptr() +
-                      string_slots_[i].slot_offset);
-
-      DCHECK(string_handle->IsThinString() ||
-             string_handle->IsInternalizedString());
-      if (*string_handle != *internalized_string) {
-        slot.Release_Store(*internalized_string);
+  {
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                 "V8.OffThreadFinalization.Publish.UpdateHandles");
+    for (size_t i = 0; i < string_slots_.size(); ++i) {
+      int slot_offset = string_slots_[i].slot_offset;
+
+      // There's currently no cases where the holder object could have been
+      // resized.
+      DCHECK_LT(slot_offset, heap_object_handles[i]->Size());
+
+      ObjectSlot slot(heap_object_handles[i]->ptr() + slot_offset);
+
+      String string = String::cast(slot.Acquire_Load());
+      if (string.IsThinString()) {
+        // We may have already internalized this string via another slot.
+        slot.Release_Store(ThinString::cast(string).GetUnderlying());
+      } else {
+        HandleScope handle_scope(isolate);
+
+        Handle<String> string_handle = handle(string, isolate);
+        Handle<String> internalized_string =
+            isolate->factory()->InternalizeString(string_handle);
+
+        // Recalculate the slot in case there was GC and the holder moved.
+        ObjectSlot slot(heap_object_handles[i]->ptr() + slot_offset);
+
+        DCHECK(string_handle->IsThinString() ||
+               string_handle->IsInternalizedString());
+        if (*string_handle != *internalized_string) {
+          slot.Release_Store(*internalized_string);
+        }
       }
     }
-  }
-}
 
-OffThreadHandle<Object> OffThreadFactory::NewInvalidStringLengthError() {
-  // TODO(leszeks): Implement.
-  UNREACHABLE();
+    // Merge the recorded scripts into the isolate's script list.
+    // This for loop may seem expensive, but practically there's unlikely to be
+    // more than one script in the OffThreadFactory.
+    Handle<WeakArrayList> scripts = isolate->factory()->script_list();
+    for (Handle<Script> script_handle : script_handles) {
+      scripts = WeakArrayList::Append(isolate, scripts,
+                                      MaybeObjectHandle::Weak(script_handle));
+    }
+    isolate->heap()->SetRootScriptList(*scripts);
+  }
 }
 
 // Hacky method for creating a simple object with a slot pointing to a string.
 // TODO(leszeks): Remove once we have full FixedArray support.
-OffThreadHandle<FixedArray> OffThreadFactory::StringWrapperForTest(
-    OffThreadHandle<String> string) {
+Handle<FixedArray> OffThreadFactory::StringWrapperForTest(
+    Handle<String> string) {
   HeapObject wrapper =
       AllocateRaw(FixedArray::SizeFor(1), AllocationType::kOld);
   wrapper.set_map_after_allocation(read_only_roots().fixed_array_map());
   FixedArray array = FixedArray::cast(wrapper);
   array.set_length(1);
   array.data_start().Relaxed_Store(*string);
-  return OffThreadHandle<FixedArray>(array);
+  return handle(array, isolate());
 }
 
-OffThreadHandle<String> OffThreadFactory::MakeOrFindTwoCharacterString(
-    uint16_t c1, uint16_t c2) {
+Handle<String> OffThreadFactory::MakeOrFindTwoCharacterString(uint16_t c1,
+                                                              uint16_t c2) {
   // TODO(leszeks): Do some real caching here. Also, these strings should be
   // internalized.
   if ((c1 | c2) <= unibrow::Latin1::kMaxChar) {
-    OffThreadHandle<SeqOneByteString> ret =
-        NewRawOneByteString(2, AllocationType::kOld);
+    Handle<SeqOneByteString> ret =
+        NewRawOneByteString(2, AllocationType::kOld).ToHandleChecked();
     ret->SeqOneByteStringSet(0, c1);
     ret->SeqOneByteStringSet(1, c2);
     return ret;
   }
-  OffThreadHandle<SeqTwoByteString> ret =
-      NewRawTwoByteString(2, AllocationType::kOld);
+  Handle<SeqTwoByteString> ret =
+      NewRawTwoByteString(2, AllocationType::kOld).ToHandleChecked();
   ret->SeqTwoByteStringSet(0, c1);
   ret->SeqTwoByteStringSet(1, c2);
   return ret;
 }
 
+Handle<String> OffThreadFactory::InternalizeString(
+    const Vector<const uint8_t>& string) {
+  uint32_t hash = StringHasher::HashSequentialString(
+      string.begin(), string.length(), HashSeed(read_only_roots()));
+  return NewOneByteInternalizedString(string, hash);
+}
+
+Handle<String> OffThreadFactory::InternalizeString(
+    const Vector<const uint16_t>& string) {
+  uint32_t hash = StringHasher::HashSequentialString(
+      string.begin(), string.length(), HashSeed(read_only_roots()));
+  return NewTwoByteInternalizedString(string, hash);
+}
+
+void OffThreadFactory::AddToScriptList(Handle<Script> shared) {
+  script_list_.push_back(*shared);
+}
+
 HeapObject OffThreadFactory::AllocateRaw(int size, AllocationType allocation,
                                          AllocationAlignment alignment) {
   DCHECK(!is_finished);
@@ -212,10 +254,5 @@ HeapObject OffThreadFactory::AllocateRaw(int size, AllocationType allocation,
   return result.ToObjectChecked();
 }
 
-void OffThreadFactory::FatalProcessOutOfHeapMemory(const char* location) {
-  // TODO(leszeks): Do something reasonable.
-  UNREACHABLE();
-}
-
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/off-thread-factory.h b/deps/v8/src/heap/off-thread-factory.h
index 244e04189d..f297bd30c6 100644
--- a/deps/v8/src/heap/off-thread-factory.h
+++ b/deps/v8/src/heap/off-thread-factory.h
@@ -7,6 +7,7 @@
 
 #include <map>
 #include <vector>
+#include "src/base/logging.h"
 #include "src/common/globals.h"
 #include "src/handles/handles.h"
 #include "src/heap/factory-base.h"
@@ -14,7 +15,9 @@
 #include "src/heap/read-only-heap.h"
 #include "src/heap/spaces.h"
 #include "src/objects/heap-object.h"
+#include "src/objects/map.h"
 #include "src/objects/objects.h"
+#include "src/objects/shared-function-info.h"
 #include "src/roots/roots.h"
 
 namespace v8 {
@@ -23,16 +26,7 @@ namespace internal {
 class AstValueFactory;
 class AstRawString;
 class AstConsString;
-
-class OffThreadFactory;
-
-template <>
-struct FactoryTraits<OffThreadFactory> {
-  template <typename T>
-  using HandleType = OffThreadHandle<T>;
-  template <typename T>
-  using MaybeHandleType = OffThreadHandle<T>;
-};
+class OffThreadIsolate;
 
 struct RelativeSlot {
   RelativeSlot() = default;
@@ -50,18 +44,29 @@ class V8_EXPORT_PRIVATE OffThreadFactory
 
   ReadOnlyRoots read_only_roots() const { return roots_; }
 
-#define ROOT_ACCESSOR(Type, name, CamelName) \
-  inline OffThreadHandle<Type> name();
+#define ROOT_ACCESSOR(Type, name, CamelName) inline Handle<Type> name();
   READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
+  // AccessorInfos appear mutable, but they're actually not mutated once they
+  // finish initializing. In particular, the root accessors are not mutated and
+  // are safe to access (as long as the off-thread job doesn't try to mutate
+  // them).
+  ACCESSOR_INFO_ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
+  Handle<String> InternalizeString(const Vector<const uint8_t>& string);
+  Handle<String> InternalizeString(const Vector<const uint16_t>& string);
+
   void FinishOffThread();
   void Publish(Isolate* isolate);
 
-  OffThreadHandle<Object> NewInvalidStringLengthError();
+  // The parser shouldn't allow the OffThreadFactory to get into a state where
+  // it generates errors.
+  Handle<Object> NewInvalidStringLengthError() { UNREACHABLE(); }
+  Handle<Object> NewRangeError(MessageTemplate template_index) {
+    UNREACHABLE();
+  }
 
-  OffThreadHandle<FixedArray> StringWrapperForTest(
-      OffThreadHandle<String> string);
+  Handle<FixedArray> StringWrapperForTest(Handle<String> string);
 
  private:
   friend class FactoryBase<OffThreadFactory>;
@@ -70,23 +75,28 @@ class V8_EXPORT_PRIVATE OffThreadFactory
   // Customization points for FactoryBase.
   HeapObject AllocateRaw(int size, AllocationType allocation,
                          AllocationAlignment alignment = kWordAligned);
-  template <typename T>
-  OffThreadHandle<T> Throw(OffThreadHandle<Object> exception) {
-    // TODO(leszeks): Figure out what to do here.
-    return OffThreadHandle<T>();
+
+  OffThreadIsolate* isolate() {
+    // Downcast to the privately inherited sub-class using c-style casts to
+    // avoid undefined behavior (as static_cast cannot cast across private
+    // bases).
+    // NOLINTNEXTLINE (google-readability-casting)
+    return (OffThreadIsolate*)this;  // NOLINT(readability/casting)
   }
-  [[noreturn]] void FatalProcessOutOfHeapMemory(const char* location);
   inline bool CanAllocateInReadOnlySpace() { return false; }
   inline bool EmptyStringRootIsInitialized() { return true; }
   // ------
 
-  OffThreadHandle<String> MakeOrFindTwoCharacterString(uint16_t c1,
-                                                       uint16_t c2);
+  Handle<String> MakeOrFindTwoCharacterString(uint16_t c1, uint16_t c2);
+
+  void AddToScriptList(Handle<Script> shared);
+  // ------
 
   ReadOnlyRoots roots_;
   OffThreadSpace space_;
   OffThreadLargeObjectSpace lo_space_;
   std::vector<RelativeSlot> string_slots_;
+  std::vector<Script> script_list_;
   bool is_finished = false;
 };
 
diff --git a/deps/v8/src/heap/read-only-heap.cc b/deps/v8/src/heap/read-only-heap.cc
index 2050d3729b..5b0e29bf12 100644
--- a/deps/v8/src/heap/read-only-heap.cc
+++ b/deps/v8/src/heap/read-only-heap.cc
@@ -52,9 +52,12 @@ void ReadOnlyHeap::SetUp(Isolate* isolate, ReadOnlyDeserializer* des) {
 #ifdef DEBUG
   const base::Optional<uint32_t> last_checksum =
       shared_ro_heap_->read_only_blob_checksum_;
-  if (last_checksum || des_checksum) {
+  if (last_checksum) {
     // The read-only heap was set up from a snapshot. Make sure it's the always
     // the same snapshot.
+    CHECK_WITH_MSG(des_checksum,
+                   "Attempt to create the read-only heap after "
+                   "already creating from a snapshot.");
     CHECK_EQ(last_checksum, des_checksum);
   } else {
     // The read-only heap objects were created. Make sure this happens only
@@ -144,9 +147,7 @@ bool ReadOnlyHeap::Contains(Address address) {
 // static
 bool ReadOnlyHeap::Contains(HeapObject object) {
   if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
-    // read only includes both TPH and the snapshot, so need both checks
-    return third_party_heap::Heap::InReadOnlySpace(object.address()) ||
-           MemoryChunk::FromHeapObject(object)->InReadOnlySpace();
+    return third_party_heap::Heap::InReadOnlySpace(object.address());
   } else {
     return MemoryChunk::FromHeapObject(object)->InReadOnlySpace();
   }
diff --git a/deps/v8/src/heap/safepoint.cc b/deps/v8/src/heap/safepoint.cc
new file mode 100644
index 0000000000..f524b30e74
--- /dev/null
+++ b/deps/v8/src/heap/safepoint.cc
@@ -0,0 +1,134 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/safepoint.h"
+
+#include "src/handles/local-handles.h"
+#include "src/heap/heap.h"
+#include "src/heap/local-heap.h"
+
+namespace v8 {
+namespace internal {
+
+Safepoint::Safepoint(Heap* heap) : heap_(heap), local_heaps_head_(nullptr) {}
+
+void Safepoint::Start() { StopThreads(); }
+
+void Safepoint::End() { ResumeThreads(); }
+
+void Safepoint::StopThreads() {
+  local_heaps_mutex_.Lock();
+
+  barrier_.Arm();
+
+  for (LocalHeap* current = local_heaps_head_; current;
+       current = current->next_) {
+    current->RequestSafepoint();
+  }
+
+  for (LocalHeap* current = local_heaps_head_; current;
+       current = current->next_) {
+    current->state_mutex_.Lock();
+
+    while (current->state_ == LocalHeap::ThreadState::Running) {
+      current->state_change_.Wait(&current->state_mutex_);
+    }
+  }
+}
+
+void Safepoint::ResumeThreads() {
+  for (LocalHeap* current = local_heaps_head_; current;
+       current = current->next_) {
+    current->state_mutex_.Unlock();
+  }
+
+  barrier_.Disarm();
+
+  local_heaps_mutex_.Unlock();
+}
+
+void Safepoint::EnterFromThread(LocalHeap* local_heap) {
+  {
+    base::MutexGuard guard(&local_heap->state_mutex_);
+    local_heap->state_ = LocalHeap::ThreadState::Safepoint;
+    local_heap->state_change_.NotifyAll();
+  }
+
+  barrier_.Wait();
+
+  {
+    base::MutexGuard guard(&local_heap->state_mutex_);
+    local_heap->state_ = LocalHeap::ThreadState::Running;
+  }
+}
+
+void Safepoint::Barrier::Arm() {
+  base::MutexGuard guard(&mutex_);
+  CHECK(!armed_);
+  armed_ = true;
+}
+
+void Safepoint::Barrier::Disarm() {
+  base::MutexGuard guard(&mutex_);
+  CHECK(armed_);
+  armed_ = false;
+  cond_.NotifyAll();
+}
+
+void Safepoint::Barrier::Wait() {
+  base::MutexGuard guard(&mutex_);
+  while (armed_) {
+    cond_.Wait(&mutex_);
+  }
+}
+
+SafepointScope::SafepointScope(Heap* heap) : safepoint_(heap->safepoint()) {
+  safepoint_->StopThreads();
+}
+
+SafepointScope::~SafepointScope() { safepoint_->ResumeThreads(); }
+
+void Safepoint::AddLocalHeap(LocalHeap* local_heap) {
+  base::MutexGuard guard(&local_heaps_mutex_);
+  if (local_heaps_head_) local_heaps_head_->prev_ = local_heap;
+  local_heap->prev_ = nullptr;
+  local_heap->next_ = local_heaps_head_;
+  local_heaps_head_ = local_heap;
+}
+
+void Safepoint::RemoveLocalHeap(LocalHeap* local_heap) {
+  base::MutexGuard guard(&local_heaps_mutex_);
+  if (local_heap->next_) local_heap->next_->prev_ = local_heap->prev_;
+  if (local_heap->prev_)
+    local_heap->prev_->next_ = local_heap->next_;
+  else
+    local_heaps_head_ = local_heap->next_;
+}
+
+bool Safepoint::ContainsLocalHeap(LocalHeap* local_heap) {
+  base::MutexGuard guard(&local_heaps_mutex_);
+  LocalHeap* current = local_heaps_head_;
+
+  while (current) {
+    if (current == local_heap) return true;
+    current = current->next_;
+  }
+
+  return false;
+}
+
+bool Safepoint::ContainsAnyLocalHeap() {
+  base::MutexGuard guard(&local_heaps_mutex_);
+  return local_heaps_head_ != nullptr;
+}
+
+void Safepoint::Iterate(RootVisitor* visitor) {
+  for (LocalHeap* current = local_heaps_head_; current;
+       current = current->next_) {
+    current->handles()->Iterate(visitor);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/heap/safepoint.h b/deps/v8/src/heap/safepoint.h
new file mode 100644
index 0000000000..4b0036c047
--- /dev/null
+++ b/deps/v8/src/heap/safepoint.h
@@ -0,0 +1,77 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_HEAP_SAFEPOINT_H_
+#define V8_HEAP_SAFEPOINT_H_
+
+#include "src/base/platform/condition-variable.h"
+#include "src/base/platform/mutex.h"
+
+namespace v8 {
+namespace internal {
+
+class Heap;
+class LocalHeap;
+class RootVisitor;
+
+class Safepoint {
+ public:
+  explicit Safepoint(Heap* heap);
+
+  // Enter the safepoint from a thread
+  void EnterFromThread(LocalHeap* local_heap);
+
+  V8_EXPORT_PRIVATE bool ContainsLocalHeap(LocalHeap* local_heap);
+  V8_EXPORT_PRIVATE bool ContainsAnyLocalHeap();
+
+  // Iterate handles in local heaps
+  void Iterate(RootVisitor* visitor);
+
+  // Use these methods now instead of the more intrusive SafepointScope
+  void Start();
+  void End();
+
+ private:
+  class Barrier {
+    base::Mutex mutex_;
+    base::ConditionVariable cond_;
+    bool armed_;
+
+   public:
+    Barrier() : armed_(false) {}
+
+    void Arm();
+    void Disarm();
+    void Wait();
+  };
+
+  void StopThreads();
+  void ResumeThreads();
+
+  void AddLocalHeap(LocalHeap* local_heap);
+  void RemoveLocalHeap(LocalHeap* local_heap);
+
+  Barrier barrier_;
+  Heap* heap_;
+
+  base::Mutex local_heaps_mutex_;
+  LocalHeap* local_heaps_head_;
+
+  friend class SafepointScope;
+  friend class LocalHeap;
+};
+
+class SafepointScope {
+ public:
+  V8_EXPORT_PRIVATE explicit SafepointScope(Heap* heap);
+  V8_EXPORT_PRIVATE ~SafepointScope();
+
+ private:
+  Safepoint* safepoint_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_HEAP_SAFEPOINT_H_
diff --git a/deps/v8/src/heap/scavenge-job.cc b/deps/v8/src/heap/scavenge-job.cc
index 3730bfeecb..a731e37be0 100644
--- a/deps/v8/src/heap/scavenge-job.cc
+++ b/deps/v8/src/heap/scavenge-job.cc
@@ -7,112 +7,59 @@
 #include "src/base/platform/time.h"
 #include "src/execution/isolate.h"
 #include "src/execution/vm-state-inl.h"
-#include "src/heap/gc-tracer.h"
 #include "src/heap/heap-inl.h"
 #include "src/heap/heap.h"
-#include "src/heap/spaces.h"
 #include "src/init/v8.h"
 
 namespace v8 {
 namespace internal {
 
+class ScavengeJob::Task : public CancelableTask {
+ public:
+  Task(Isolate* isolate, ScavengeJob* job)
+      : CancelableTask(isolate), isolate_(isolate), job_(job) {}
 
-const double ScavengeJob::kMaxAllocationLimitAsFractionOfNewSpace = 0.8;
+  // CancelableTask overrides.
+  void RunInternal() override;
 
-void ScavengeJob::IdleTask::RunInternal(double deadline_in_seconds) {
-  VMState<GC> state(isolate());
-  TRACE_EVENT_CALL_STATS_SCOPED(isolate(), "v8", "V8.Task");
-  Heap* heap = isolate()->heap();
-  double deadline_in_ms =
-      deadline_in_seconds *
-      static_cast<double>(base::Time::kMillisecondsPerSecond);
-  double start_ms = heap->MonotonicallyIncreasingTimeInMs();
-  double idle_time_in_ms = deadline_in_ms - start_ms;
-  double scavenge_speed_in_bytes_per_ms =
-      heap->tracer()->ScavengeSpeedInBytesPerMillisecond();
-  size_t new_space_size = heap->new_space()->Size();
-  size_t new_space_capacity = heap->new_space()->Capacity();
+  Isolate* isolate() const { return isolate_; }
 
-  job_->NotifyIdleTask();
+ private:
+  Isolate* const isolate_;
+  ScavengeJob* const job_;
+};
 
-  if (ReachedIdleAllocationLimit(scavenge_speed_in_bytes_per_ms, new_space_size,
-                                 new_space_capacity)) {
-    if (EnoughIdleTimeForScavenge(
-            idle_time_in_ms, scavenge_speed_in_bytes_per_ms, new_space_size)) {
-      heap->CollectGarbage(NEW_SPACE, GarbageCollectionReason::kIdleTask);
-    } else {
-      // Immediately request another idle task that can get larger idle time.
-      job_->RescheduleIdleTask(heap);
-    }
-  }
+size_t ScavengeJob::YoungGenerationTaskTriggerSize(Heap* heap) {
+  static constexpr double kTaskTriggerFactor = 0.8;
+  return heap->new_space()->Capacity() * kTaskTriggerFactor;
 }
 
-bool ScavengeJob::ReachedIdleAllocationLimit(
-    double scavenge_speed_in_bytes_per_ms, size_t new_space_size,
-    size_t new_space_capacity) {
-  if (scavenge_speed_in_bytes_per_ms == 0) {
-    scavenge_speed_in_bytes_per_ms = kInitialScavengeSpeedInBytesPerMs;
-  }
-
-  // Set the allocation limit to the number of bytes we can scavenge in an
-  // average idle task.
-  double allocation_limit = kAverageIdleTimeMs * scavenge_speed_in_bytes_per_ms;
-
-  // Keep the limit smaller than the new space capacity.
-  allocation_limit =
-      Min<double>(allocation_limit,
-                  new_space_capacity * kMaxAllocationLimitAsFractionOfNewSpace);
-  // Adjust the limit to take into account bytes that will be allocated until
-  // the next check and keep the limit large enough to avoid scavenges in tiny
-  // new space.
-  allocation_limit =
-      Max<double>(allocation_limit - kBytesAllocatedBeforeNextIdleTask,
-                  kMinAllocationLimit);
-
-  return allocation_limit <= new_space_size;
+bool ScavengeJob::YoungGenerationSizeTaskTriggerReached(Heap* heap) {
+  return heap->new_space()->Size() >= YoungGenerationTaskTriggerSize(heap);
 }
 
-bool ScavengeJob::EnoughIdleTimeForScavenge(
-    double idle_time_in_ms, double scavenge_speed_in_bytes_per_ms,
-    size_t new_space_size) {
-  if (scavenge_speed_in_bytes_per_ms == 0) {
-    scavenge_speed_in_bytes_per_ms = kInitialScavengeSpeedInBytesPerMs;
+void ScavengeJob::ScheduleTaskIfNeeded(Heap* heap) {
+  if (!task_pending_ && !heap->IsTearingDown() &&
+      YoungGenerationSizeTaskTriggerReached(heap)) {
+    v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate());
+    auto taskrunner =
+        V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate);
+    taskrunner->PostTask(std::make_unique<Task>(heap->isolate(), this));
+    task_pending_ = true;
   }
-  return new_space_size <= idle_time_in_ms * scavenge_speed_in_bytes_per_ms;
 }
 
+void ScavengeJob::Task::RunInternal() {
+  VMState<GC> state(isolate());
+  TRACE_EVENT_CALL_STATS_SCOPED(isolate(), "v8", "V8.Task");
 
-void ScavengeJob::RescheduleIdleTask(Heap* heap) {
-  // Make sure that we don't reschedule more than one time.
-  // Otherwise, we might spam the scheduler with idle tasks.
-  if (!idle_task_rescheduled_) {
-    ScheduleIdleTask(heap);
-    idle_task_rescheduled_ = true;
+  if (ScavengeJob::YoungGenerationSizeTaskTriggerReached(isolate()->heap())) {
+    isolate()->heap()->CollectGarbage(NEW_SPACE,
+                                      GarbageCollectionReason::kTask);
   }
-}
 
-
-void ScavengeJob::ScheduleIdleTaskIfNeeded(Heap* heap, int bytes_allocated) {
-  bytes_allocated_since_the_last_task_ += bytes_allocated;
-  if (bytes_allocated_since_the_last_task_ >=
-      static_cast<int>(kBytesAllocatedBeforeNextIdleTask)) {
-    ScheduleIdleTask(heap);
-    bytes_allocated_since_the_last_task_ = 0;
-    idle_task_rescheduled_ = false;
-  }
+  job_->set_task_pending(false);
 }
 
-
-void ScavengeJob::ScheduleIdleTask(Heap* heap) {
-  if (!idle_task_pending_ && !heap->IsTearingDown()) {
-    v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate());
-    if (V8::GetCurrentPlatform()->IdleTasksEnabled(isolate)) {
-      idle_task_pending_ = true;
-      auto task = std::make_unique<IdleTask>(heap->isolate(), this);
-      V8::GetCurrentPlatform()->GetForegroundTaskRunner(isolate)->PostIdleTask(
-          std::move(task));
-    }
-  }
-}
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/scavenge-job.h b/deps/v8/src/heap/scavenge-job.h
index 2b35ccbb18..815f1b8d09 100644
--- a/deps/v8/src/heap/scavenge-job.h
+++ b/deps/v8/src/heap/scavenge-job.h
@@ -5,7 +5,6 @@
 #ifndef V8_HEAP_SCAVENGE_JOB_H_
 #define V8_HEAP_SCAVENGE_JOB_H_
 
-#include "src/common/globals.h"
 #include "src/tasks/cancelable-task.h"
 
 namespace v8 {
@@ -14,67 +13,24 @@ namespace internal {
 class Heap;
 class Isolate;
 
-// This class posts idle tasks and performs scavenges in the idle tasks.
-class V8_EXPORT_PRIVATE ScavengeJob {
+// The scavenge job uses platform tasks to perform a young generation
+// Scavenge garbage collection. The job posts a foreground task.
+class ScavengeJob {
  public:
-  class IdleTask : public CancelableIdleTask {
-   public:
-    explicit IdleTask(Isolate* isolate, ScavengeJob* job)
-        : CancelableIdleTask(isolate), isolate_(isolate), job_(job) {}
-    // CancelableIdleTask overrides.
-    void RunInternal(double deadline_in_seconds) override;
+  ScavengeJob() V8_NOEXCEPT = default;
 
-    Isolate* isolate() { return isolate_; }
+  void ScheduleTaskIfNeeded(Heap* heap);
 
-   private:
-    Isolate* isolate_;
-    ScavengeJob* job_;
-  };
+  static size_t YoungGenerationTaskTriggerSize(Heap* heap);
 
-  ScavengeJob()
-      : idle_task_pending_(false),
-        idle_task_rescheduled_(false),
-        bytes_allocated_since_the_last_task_(0) {}
-
-  // Posts an idle task if the cumulative bytes allocated since the last
-  // idle task exceed kBytesAllocatedBeforeNextIdleTask.
-  void ScheduleIdleTaskIfNeeded(Heap* heap, int bytes_allocated);
-
-  // Posts an idle task ignoring the bytes allocated, but makes sure
-  // that the new idle task cannot reschedule again.
-  // This prevents infinite rescheduling.
-  void RescheduleIdleTask(Heap* heap);
-
-  bool IdleTaskPending() { return idle_task_pending_; }
-  void NotifyIdleTask() { idle_task_pending_ = false; }
-  bool IdleTaskRescheduled() { return idle_task_rescheduled_; }
-
-  static bool ReachedIdleAllocationLimit(double scavenge_speed_in_bytes_per_ms,
-                                         size_t new_space_size,
-                                         size_t new_space_capacity);
+ private:
+  class Task;
 
-  static bool EnoughIdleTimeForScavenge(double idle_time_ms,
-                                        double scavenge_speed_in_bytes_per_ms,
-                                        size_t new_space_size);
+  static bool YoungGenerationSizeTaskTriggerReached(Heap* heap);
 
-  // If we haven't recorded any scavenger events yet, we use a conservative
-  // lower bound for the scavenger speed.
-  static const int kInitialScavengeSpeedInBytesPerMs = 256 * KB;
-  // Estimate of the average idle time that an idle task gets.
-  static const int kAverageIdleTimeMs = 5;
-  // The number of bytes to be allocated in new space before the next idle
-  // task is posted.
-  static const size_t kBytesAllocatedBeforeNextIdleTask = 1024 * KB;
-  // The minimum size of allocated new space objects to trigger a scavenge.
-  static const size_t kMinAllocationLimit = 512 * KB;
-  // The allocation limit cannot exceed this fraction of the new space capacity.
-  static const double kMaxAllocationLimitAsFractionOfNewSpace;
+  void set_task_pending(bool value) { task_pending_ = value; }
 
- private:
-  void ScheduleIdleTask(Heap* heap);
-  bool idle_task_pending_;
-  bool idle_task_rescheduled_;
-  int bytes_allocated_since_the_last_task_;
+  bool task_pending_ = false;
 };
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/heap/setup-heap-internal.cc b/deps/v8/src/heap/setup-heap-internal.cc
index 58929c6691..8c9d8cd456 100644
--- a/deps/v8/src/heap/setup-heap-internal.cc
+++ b/deps/v8/src/heap/setup-heap-internal.cc
@@ -67,6 +67,10 @@ bool Heap::CreateHeapObjects() {
 
   set_native_contexts_list(ReadOnlyRoots(this).undefined_value());
   set_allocation_sites_list(ReadOnlyRoots(this).undefined_value());
+  set_dirty_js_finalization_registries_list(
+      ReadOnlyRoots(this).undefined_value());
+  set_dirty_js_finalization_registries_list_tail(
+      ReadOnlyRoots(this).undefined_value());
 
   return true;
 }
@@ -399,6 +403,18 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_VARSIZE_MAP(SMALL_ORDERED_NAME_DICTIONARY_TYPE,
                          small_ordered_name_dictionary)
 
+#define TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR(V, NAME, Name, name) \
+  ALLOCATE_MAP(NAME, Name::kSize, name)
+    TORQUE_INTERNAL_FIXED_CLASS_LIST_GENERATOR(
+        TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR, _);
+#undef TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR
+
+#define TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR(V, NAME, Name, name) \
+  ALLOCATE_VARSIZE_MAP(NAME, name)
+    TORQUE_INTERNAL_VARSIZE_CLASS_LIST_GENERATOR(
+        TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR, _);
+#undef TORQUE_INTERNAL_CLASS_LIST_MAP_ALLOCATOR
+
     ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, sloppy_arguments_elements)
 
     ALLOCATE_VARSIZE_MAP(CODE_TYPE, code)
@@ -452,6 +468,8 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_VARSIZE_MAP(OBJECT_BOILERPLATE_DESCRIPTION_TYPE,
                          object_boilerplate_description)
 
+    ALLOCATE_VARSIZE_MAP(COVERAGE_INFO_TYPE, coverage_info);
+
     ALLOCATE_MAP(CALL_HANDLER_INFO_TYPE, CallHandlerInfo::kSize,
                  side_effect_call_handler_info)
     ALLOCATE_MAP(CALL_HANDLER_INFO_TYPE, CallHandlerInfo::kSize,
@@ -618,7 +636,6 @@ void Heap::CreateInitialObjects() {
   // There's no "current microtask" in the beginning.
   set_current_microtask(roots.undefined_value());
 
-  set_dirty_js_finalization_groups(roots.undefined_value());
   set_weak_refs_keep_during_job(roots.undefined_value());
 
   // Allocate cache for single character one byte strings.
diff --git a/deps/v8/src/heap/spaces.cc b/deps/v8/src/heap/spaces.cc
index bfa568dd29..a7aec2ff1f 100644
--- a/deps/v8/src/heap/spaces.cc
+++ b/deps/v8/src/heap/spaces.cc
@@ -14,6 +14,7 @@
 #include "src/base/platform/semaphore.h"
 #include "src/common/globals.h"
 #include "src/execution/vm-state-inl.h"
+#include "src/heap/array-buffer-sweeper.h"
 #include "src/heap/array-buffer-tracker-inl.h"
 #include "src/heap/combined-heap.h"
 #include "src/heap/concurrent-marking.h"
@@ -155,7 +156,7 @@ void MemoryAllocator::InitializeCodePageAllocator(
   code_page_allocator_ = page_allocator;
 
   if (requested == 0) {
-    if (!kRequiresCodeRange) return;
+    if (!isolate_->RequiresCodeRange()) return;
     // When a target requires the code range feature, we put all code objects
     // in a kMaximalCodeRangeSize range of virtual address space, so that
     // they can call each other with near calls.
@@ -172,7 +173,7 @@ void MemoryAllocator::InitializeCodePageAllocator(
     // alignments is not supported (requires re-implementation).
     DCHECK_LE(kMinExpectedOSPageSize, page_allocator->AllocatePageSize());
   }
-  DCHECK(!kRequiresCodeRange || requested <= kMaximalCodeRangeSize);
+  DCHECK(!isolate_->RequiresCodeRange() || requested <= kMaximalCodeRangeSize);
 
   Address hint =
       RoundDown(code_range_address_hint.Pointer()->GetAddressHint(requested),
@@ -213,7 +214,7 @@ void MemoryAllocator::InitializeCodePageAllocator(
       NewEvent("CodeRange", reinterpret_cast<void*>(reservation.address()),
                requested));
 
-  heap_reservation_ = std::move(reservation);
+  code_reservation_ = std::move(reservation);
   code_page_allocator_instance_ = std::make_unique<base::BoundedPageAllocator>(
       page_allocator, aligned_base, size,
       static_cast<size_t>(MemoryChunk::kAlignment));
@@ -761,7 +762,8 @@ Page* PagedSpace::InitializePage(MemoryChunk* chunk) {
       page->area_size());
   // Make sure that categories are initialized before freeing the area.
   page->ResetAllocationStatistics();
-  page->SetOldGenerationPageFlags(heap()->incremental_marking()->IsMarking());
+  page->SetOldGenerationPageFlags(!is_off_thread_space() &&
+                                  heap()->incremental_marking()->IsMarking());
   page->AllocateFreeListCategories();
   page->InitializeFreeListCategories();
   page->list_node().Initialize();
@@ -1118,7 +1120,7 @@ size_t Page::ShrinkToHighWaterMark() {
 void Page::CreateBlackArea(Address start, Address end) {
   DCHECK(heap()->incremental_marking()->black_allocation());
   DCHECK_EQ(Page::FromAddress(start), this);
-  DCHECK_NE(start, end);
+  DCHECK_LT(start, end);
   DCHECK_EQ(Page::FromAddress(end - 1), this);
   IncrementalMarking::MarkingState* marking_state =
       heap()->incremental_marking()->marking_state();
@@ -1130,7 +1132,7 @@ void Page::CreateBlackArea(Address start, Address end) {
 void Page::DestroyBlackArea(Address start, Address end) {
   DCHECK(heap()->incremental_marking()->black_allocation());
   DCHECK_EQ(Page::FromAddress(start), this);
-  DCHECK_NE(start, end);
+  DCHECK_LT(start, end);
   DCHECK_EQ(Page::FromAddress(end - 1), this);
   IncrementalMarking::MarkingState* marking_state =
       heap()->incremental_marking()->marking_state();
@@ -1743,6 +1745,7 @@ void PagedSpace::MergeLocalSpace(LocalSpace* other) {
 
     if (merging_from_off_thread) {
       DCHECK_NULL(p->sweeping_slot_set());
+      p->SetOldGenerationPageFlags(heap()->incremental_marking()->IsMarking());
       if (heap()->incremental_marking()->black_allocation()) {
         p->CreateBlackArea(p->area_start(), p->HighWaterMark());
       }
@@ -1911,7 +1914,7 @@ int PagedSpace::CountTotalPages() {
 
 void PagedSpace::SetLinearAllocationArea(Address top, Address limit) {
   SetTopAndLimit(top, limit);
-  if (top != kNullAddress && top != limit &&
+  if (top != kNullAddress && top != limit && !is_off_thread_space() &&
       heap()->incremental_marking()->black_allocation()) {
     Page::FromAllocationAreaAddress(top)->CreateBlackArea(top, limit);
   }
@@ -1995,7 +1998,8 @@ void PagedSpace::FreeLinearAllocationArea() {
     return;
   }
 
-  if (heap()->incremental_marking()->black_allocation()) {
+  if (!is_off_thread_space() &&
+      heap()->incremental_marking()->black_allocation()) {
     Page* page = Page::FromAllocationAreaAddress(current_top);
 
     // Clear the bits in the unused black area.
@@ -2199,7 +2203,9 @@ void PagedSpace::Verify(Isolate* isolate, ObjectVisitor* visitor) {
       } else if (object.IsJSArrayBuffer()) {
         JSArrayBuffer array_buffer = JSArrayBuffer::cast(object);
         if (ArrayBufferTracker::IsTracked(array_buffer)) {
-          size_t size = PerIsolateAccountingLength(array_buffer);
+          size_t size =
+              ArrayBufferTracker::Lookup(isolate->heap(), array_buffer)
+                  ->PerIsolateAccountingLength();
           external_page_bytes[ExternalBackingStoreType::kArrayBuffer] += size;
         }
       }
@@ -2211,10 +2217,20 @@ void PagedSpace::Verify(Isolate* isolate, ObjectVisitor* visitor) {
     }
   }
   for (int i = 0; i < kNumTypes; i++) {
+    if (V8_ARRAY_BUFFER_EXTENSION_BOOL &&
+        i == ExternalBackingStoreType::kArrayBuffer)
+      continue;
     ExternalBackingStoreType t = static_cast<ExternalBackingStoreType>(i);
     CHECK_EQ(external_space_bytes[t], ExternalBackingStoreBytes(t));
   }
   CHECK(allocation_pointer_found_in_space);
+
+  if (identity() == OLD_SPACE && V8_ARRAY_BUFFER_EXTENSION_BOOL) {
+    size_t bytes = heap()->array_buffer_sweeper()->old().BytesSlow();
+    CHECK_EQ(bytes,
+             ExternalBackingStoreBytes(ExternalBackingStoreType::kArrayBuffer));
+  }
+
 #ifdef DEBUG
   VerifyCountersAfterSweeping(isolate->heap());
 #endif
@@ -2687,7 +2703,8 @@ void NewSpace::Verify(Isolate* isolate) {
       } else if (object.IsJSArrayBuffer()) {
         JSArrayBuffer array_buffer = JSArrayBuffer::cast(object);
         if (ArrayBufferTracker::IsTracked(array_buffer)) {
-          size_t size = PerIsolateAccountingLength(array_buffer);
+          size_t size = ArrayBufferTracker::Lookup(heap(), array_buffer)
+                            ->PerIsolateAccountingLength();
           external_space_bytes[ExternalBackingStoreType::kArrayBuffer] += size;
         }
       }
@@ -2701,10 +2718,19 @@ void NewSpace::Verify(Isolate* isolate) {
   }
 
   for (int i = 0; i < kNumTypes; i++) {
+    if (V8_ARRAY_BUFFER_EXTENSION_BOOL &&
+        i == ExternalBackingStoreType::kArrayBuffer)
+      continue;
     ExternalBackingStoreType t = static_cast<ExternalBackingStoreType>(i);
     CHECK_EQ(external_space_bytes[t], ExternalBackingStoreBytes(t));
   }
 
+  if (V8_ARRAY_BUFFER_EXTENSION_BOOL) {
+    size_t bytes = heap()->array_buffer_sweeper()->young().BytesSlow();
+    CHECK_EQ(bytes,
+             ExternalBackingStoreBytes(ExternalBackingStoreType::kArrayBuffer));
+  }
+
   // Check semi-spaces.
   CHECK_EQ(from_space_.id(), kFromSpace);
   CHECK_EQ(to_space_.id(), kToSpace);
@@ -4487,7 +4513,12 @@ void CodeLargeObjectSpace::RemovePage(LargePage* page, size_t object_size) {
 }
 
 OffThreadLargeObjectSpace::OffThreadLargeObjectSpace(Heap* heap)
-    : LargeObjectSpace(heap, LO_SPACE) {}
+    : LargeObjectSpace(heap, LO_SPACE) {
+#ifdef V8_ENABLE_THIRD_PARTY_HEAP
+  // OffThreadLargeObjectSpace doesn't work with third-party heap.
+  UNREACHABLE();
+#endif
+}
 
 AllocationResult OffThreadLargeObjectSpace::AllocateRaw(int object_size) {
   LargePage* page = AllocateLargePage(object_size, NOT_EXECUTABLE);
diff --git a/deps/v8/src/heap/spaces.h b/deps/v8/src/heap/spaces.h
index 9d0de53f82..8d587443e3 100644
--- a/deps/v8/src/heap/spaces.h
+++ b/deps/v8/src/heap/spaces.h
@@ -5,6 +5,7 @@
 #ifndef V8_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
+#include <atomic>
 #include <list>
 #include <map>
 #include <memory>
@@ -641,10 +642,12 @@ class MemoryChunk : public BasicMemoryChunk {
 
   // Only works if the pointer is in the first kPageSize of the MemoryChunk.
   static MemoryChunk* FromAddress(Address a) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<MemoryChunk*>(BaseAddress(a));
   }
   // Only works if the object is in the first kPageSize of the MemoryChunk.
   static MemoryChunk* FromHeapObject(HeapObject o) {
+    DCHECK(!V8_ENABLE_THIRD_PARTY_HEAP_BOOL);
     return reinterpret_cast<MemoryChunk*>(BaseAddress(o.ptr()));
   }
 
@@ -658,12 +661,11 @@ class MemoryChunk : public BasicMemoryChunk {
     // to another chunk. See the comment to Page::FromAllocationAreaAddress.
     MemoryChunk* chunk = MemoryChunk::FromAddress(mark - 1);
     intptr_t new_mark = static_cast<intptr_t>(mark - chunk->address());
-    intptr_t old_mark = 0;
-    do {
-      old_mark = chunk->high_water_mark_;
-    } while (
-        (new_mark > old_mark) &&
-        !chunk->high_water_mark_.compare_exchange_weak(old_mark, new_mark));
+    intptr_t old_mark = chunk->high_water_mark_.load(std::memory_order_relaxed);
+    while ((new_mark > old_mark) &&
+           !chunk->high_water_mark_.compare_exchange_weak(
+               old_mark, new_mark, std::memory_order_acq_rel)) {
+    }
   }
 
   static inline void MoveExternalBackingStoreBytes(
@@ -1451,15 +1453,14 @@ class MemoryAllocator {
     // The use of atomic primitives does not guarantee correctness (wrt.
     // desired semantics) by default. The loop here ensures that we update the
     // values only if they did not change in between.
-    Address ptr = kNullAddress;
-    do {
-      ptr = lowest_ever_allocated_;
-    } while ((low < ptr) &&
-             !lowest_ever_allocated_.compare_exchange_weak(ptr, low));
-    do {
-      ptr = highest_ever_allocated_;
-    } while ((high > ptr) &&
-             !highest_ever_allocated_.compare_exchange_weak(ptr, high));
+    Address ptr = lowest_ever_allocated_.load(std::memory_order_relaxed);
+    while ((low < ptr) && !lowest_ever_allocated_.compare_exchange_weak(
+                              ptr, low, std::memory_order_acq_rel)) {
+    }
+    ptr = highest_ever_allocated_.load(std::memory_order_relaxed);
+    while ((high > ptr) && !highest_ever_allocated_.compare_exchange_weak(
+                               ptr, high, std::memory_order_acq_rel)) {
+    }
   }
 
   void RegisterExecutableMemoryChunk(MemoryChunk* chunk) {
@@ -1476,14 +1477,9 @@ class MemoryAllocator {
 
   Isolate* isolate_;
 
-  // This object controls virtual space reserved for V8 heap instance.
-  // Depending on the configuration it may contain the following:
-  // - no reservation (on 32-bit architectures)
-  // - code range reservation used by bounded code page allocator (on 64-bit
-  //   architectures without pointers compression in V8 heap)
-  // - data + code range reservation (on 64-bit architectures with pointers
-  //   compression in V8 heap)
-  VirtualMemory heap_reservation_;
+  // This object controls virtual space reserved for code on the V8 heap. This
+  // is only valid for 64-bit architectures where kRequiresCodeRange.
+  VirtualMemory code_reservation_;
 
   // Page allocator used for allocating data pages. Depending on the
   // configuration it may be a page allocator instance provided by v8::Platform
@@ -1497,7 +1493,7 @@ class MemoryAllocator {
   // can be used for call and jump instructions).
   v8::PageAllocator* code_page_allocator_;
 
-  // A part of the |heap_reservation_| that may contain executable code
+  // A part of the |code_reservation_| that may contain executable code
   // including reserved page with read-write access in the beginning.
   // See details below.
   base::AddressRegion code_range_;
@@ -1506,9 +1502,9 @@ class MemoryAllocator {
   // that controls executable pages allocation. It does not control the
   // optionally existing page in the beginning of the |code_range_|.
   // So, summarizing all above, the following conditions hold:
-  // 1) |heap_reservation_| >= |code_range_|
+  // 1) |code_reservation_| >= |code_range_|
   // 2) |code_range_| >= |optional RW pages| + |code_page_allocator_instance_|.
-  // 3) |heap_reservation_| is AllocatePageSize()-aligned
+  // 3) |code_reservation_| is AllocatePageSize()-aligned
   // 4) |code_page_allocator_instance_| is MemoryChunk::kAlignment-aligned
   // 5) |code_range_| is CommitPageSize()-aligned
   std::unique_ptr<base::BoundedPageAllocator> code_page_allocator_instance_;
@@ -2869,6 +2865,9 @@ class V8_EXPORT_PRIVATE NewSpace
   }
 
   size_t ExternalBackingStoreBytes(ExternalBackingStoreType type) const final {
+    if (V8_ARRAY_BUFFER_EXTENSION_BOOL &&
+        type == ExternalBackingStoreType::kArrayBuffer)
+      return heap()->YoungArrayBufferBytes();
     DCHECK_EQ(0, from_space_.ExternalBackingStoreBytes(type));
     return to_space_.ExternalBackingStoreBytes(type);
   }
@@ -3133,6 +3132,13 @@ class OldSpace : public PagedSpace {
     return static_cast<intptr_t>(addr & kPageAlignmentMask) ==
            MemoryChunkLayout::ObjectStartOffsetInDataPage();
   }
+
+  size_t ExternalBackingStoreBytes(ExternalBackingStoreType type) const final {
+    if (V8_ARRAY_BUFFER_EXTENSION_BOOL &&
+        type == ExternalBackingStoreType::kArrayBuffer)
+      return heap()->OldArrayBufferBytes();
+    return external_backing_store_bytes_[type];
+  }
 };
 
 // -----------------------------------------------------------------------------
@@ -3184,7 +3190,12 @@ class V8_EXPORT_PRIVATE OffThreadSpace : public LocalSpace {
  public:
   explicit OffThreadSpace(Heap* heap)
       : LocalSpace(heap, OLD_SPACE, NOT_EXECUTABLE,
-                   LocalSpaceKind::kOffThreadSpace) {}
+                   LocalSpaceKind::kOffThreadSpace) {
+#ifdef V8_ENABLE_THIRD_PARTY_HEAP
+    // OffThreadSpace doesn't work with third-party heap.
+    UNREACHABLE();
+#endif
+  }
 
  protected:
   V8_WARN_UNUSED_RESULT bool SlowRefillLinearAllocationArea(
@@ -3289,6 +3300,8 @@ class V8_EXPORT_PRIVATE LargeObjectSpace : public Space {
 
   std::unique_ptr<ObjectIterator> GetObjectIterator(Heap* heap) override;
 
+  virtual bool is_off_thread() const { return false; }
+
 #ifdef VERIFY_HEAP
   virtual void Verify(Isolate* isolate);
 #endif
@@ -3393,6 +3406,8 @@ class V8_EXPORT_PRIVATE OffThreadLargeObjectSpace : public LargeObjectSpace {
 
   void FreeUnmarkedObjects() override;
 
+  bool is_off_thread() const override { return true; }
+
  protected:
   // OldLargeObjectSpace can mess with OffThreadLargeObjectSpace during merging.
   friend class OldLargeObjectSpace;
diff --git a/deps/v8/src/heap/third-party/heap-api.h b/deps/v8/src/heap/third-party/heap-api.h
index 69a84114ee..5eaae847a7 100644
--- a/deps/v8/src/heap/third-party/heap-api.h
+++ b/deps/v8/src/heap/third-party/heap-api.h
@@ -6,6 +6,7 @@
 #define V8_HEAP_THIRD_PARTY_HEAP_API_H_
 
 #include "include/v8.h"
+#include "src/base/address-region.h"
 #include "src/heap/heap.h"
 
 namespace v8 {
@@ -14,15 +15,17 @@ namespace third_party_heap {
 
 class Heap {
  public:
-  static std::unique_ptr<Heap> New(v8::Isolate* isolate);
+  static std::unique_ptr<Heap> New(v8::internal::Isolate* isolate);
 
-  static v8::Isolate* GetIsolate(Address address);
+  static v8::internal::Isolate* GetIsolate(Address address);
 
   AllocationResult Allocate(size_t size_in_bytes, AllocationType type,
                             AllocationAlignment align);
 
   Address GetObjectFromInnerPointer(Address inner_pointer);
 
+  const base::AddressRegion& GetCodeRange();
+
   static bool InCodeSpace(Address address);
 
   static bool InReadOnlySpace(Address address);
diff --git a/deps/v8/src/heap/worklist.h b/deps/v8/src/heap/worklist.h
index 82a278a042..0f5f13cdf7 100644
--- a/deps/v8/src/heap/worklist.h
+++ b/deps/v8/src/heap/worklist.h
@@ -148,6 +148,9 @@ class Worklist {
            private_push_segment(task_id)->Size();
   }
 
+  // Thread-safe but may return an outdated result.
+  size_t GlobalPoolSize() const { return global_pool_.Size(); }
+
   // Clears all segments. Frees the global segment pool.
   //
   // Assumes that no other tasks are running.
@@ -201,8 +204,7 @@ class Worklist {
   }
 
   void MergeGlobalPool(Worklist* other) {
-    auto pair = other->global_pool_.Extract();
-    global_pool_.MergeList(pair.first, pair.second);
+    global_pool_.Merge(&other->global_pool_);
   }
 
  private:
@@ -282,17 +284,23 @@ class Worklist {
       Segment* temp = top_;
       set_top(other.top_);
       other.set_top(temp);
+      size_t other_size = other.size_.exchange(
+          size_.load(std::memory_order_relaxed), std::memory_order_relaxed);
+      size_.store(other_size, std::memory_order_relaxed);
     }
 
     V8_INLINE void Push(Segment* segment) {
       base::MutexGuard guard(&lock_);
       segment->set_next(top_);
       set_top(segment);
+      size_.fetch_add(1, std::memory_order_relaxed);
     }
 
     V8_INLINE bool Pop(Segment** segment) {
       base::MutexGuard guard(&lock_);
       if (top_ != nullptr) {
+        DCHECK_LT(0U, size_);
+        size_.fetch_sub(1, std::memory_order_relaxed);
         *segment = top_;
         set_top(top_->next());
         return true;
@@ -304,8 +312,16 @@ class Worklist {
       return base::AsAtomicPointer::Relaxed_Load(&top_) == nullptr;
     }
 
+    V8_INLINE size_t Size() const {
+      // It is safe to read |size_| without a lock since this variable is
+      // atomic, keeping in mind that threads may not immediately see the new
+      // value when it is updated.
+      return size_.load(std::memory_order_relaxed);
+    }
+
     void Clear() {
       base::MutexGuard guard(&lock_);
+      size_.store(0, std::memory_order_relaxed);
       Segment* current = top_;
       while (current != nullptr) {
         Segment* tmp = current;
@@ -321,9 +337,12 @@ class Worklist {
       base::MutexGuard guard(&lock_);
       Segment* prev = nullptr;
       Segment* current = top_;
+      size_t num_deleted = 0;
       while (current != nullptr) {
         current->Update(callback);
         if (current->IsEmpty()) {
+          DCHECK_LT(0U, size_);
+          ++num_deleted;
           if (prev == nullptr) {
             top_ = current->next();
           } else {
@@ -337,6 +356,7 @@ class Worklist {
           current = current->next();
         }
       }
+      size_.fetch_sub(num_deleted, std::memory_order_relaxed);
     }
 
     // See Worklist::Iterate.
@@ -349,25 +369,28 @@ class Worklist {
       }
     }
 
-    std::pair<Segment*, Segment*> Extract() {
+    void Merge(GlobalPool* other) {
       Segment* top = nullptr;
+      size_t other_size = 0;
       {
-        base::MutexGuard guard(&lock_);
-        if (top_ == nullptr) return std::make_pair(nullptr, nullptr);
-        top = top_;
-        set_top(nullptr);
+        base::MutexGuard guard(&other->lock_);
+        if (!other->top_) return;
+        top = other->top_;
+        other_size = other->size_.load(std::memory_order_relaxed);
+        other->size_.store(0, std::memory_order_relaxed);
+        other->set_top(nullptr);
       }
+
+      // It's safe to iterate through these segments because the top was
+      // extracted from |other|.
       Segment* end = top;
-      while (end->next() != nullptr) end = end->next();
-      return std::make_pair(top, end);
-    }
+      while (end->next()) end = end->next();
 
-    void MergeList(Segment* start, Segment* end) {
-      if (start == nullptr) return;
       {
         base::MutexGuard guard(&lock_);
+        size_.fetch_add(other_size, std::memory_order_relaxed);
         end->set_next(top_);
-        set_top(start);
+        set_top(top);
       }
     }
 
@@ -378,6 +401,7 @@ class Worklist {
 
     base::Mutex lock_;
     Segment* top_;
+    std::atomic<size_t> size_{0};
   };
 
   V8_INLINE Segment*& private_push_segment(int task_id) {
diff --git a/deps/v8/src/ic/accessor-assembler.cc b/deps/v8/src/ic/accessor-assembler.cc
index 1fd29fe169..d3731a7465 100644
--- a/deps/v8/src/ic/accessor-assembler.cc
+++ b/deps/v8/src/ic/accessor-assembler.cc
@@ -64,8 +64,9 @@ TNode<MaybeObject> AccessorAssembler::LoadHandlerDataField(
 }
 
 TNode<MaybeObject> AccessorAssembler::TryMonomorphicCase(
-    TNode<Smi> slot, TNode<FeedbackVector> vector, TNode<Map> receiver_map,
-    Label* if_handler, TVariable<MaybeObject>* var_handler, Label* if_miss) {
+    TNode<TaggedIndex> slot, TNode<FeedbackVector> vector,
+    TNode<Map> receiver_map, Label* if_handler,
+    TVariable<MaybeObject>* var_handler, Label* if_miss) {
   Comment("TryMonomorphicCase");
   DCHECK_EQ(MachineRepresentation::kTagged, var_handler->rep());
 
@@ -225,10 +226,9 @@ void AccessorAssembler::HandleLoadAccessor(
   Goto(&load);
 
   BIND(&load);
-  Callable callable = CodeFactory::CallApiCallback(isolate());
   TNode<IntPtrT> argc = IntPtrConstant(0);
-  exit_point->Return(CallStub(callable, context, callback, argc, data,
-                              api_holder.value(), p->receiver()));
+  exit_point->Return(CallApiCallback(context, callback, argc, data,
+                                     api_holder.value(), p->receiver()));
 }
 
 void AccessorAssembler::HandleLoadField(TNode<JSObject> holder,
@@ -563,8 +563,7 @@ void AccessorAssembler::HandleLoadICSmiHandlerLoadNamedCase(
         LoadObjectField(accessor_pair, AccessorPair::kGetterOffset);
     CSA_ASSERT(this, Word32BinaryNot(IsTheHole(getter)));
 
-    Callable callable = CodeFactory::Call(isolate());
-    exit_point->Return(CallJS(callable, p->context(), getter, p->receiver()));
+    exit_point->Return(Call(p->context(), getter, p->receiver()));
   }
 
   BIND(&native_data_property);
@@ -1496,7 +1495,7 @@ void AccessorAssembler::HandleStoreAccessor(const StoreICParameters* p,
   CSA_ASSERT(this, Word32BinaryNot(IsTheHole(setter)));
 
   Callable callable = CodeFactory::Call(isolate());
-  Return(CallJS(callable, p->context(), setter, p->receiver(), p->value()));
+  Return(Call(p->context(), setter, p->receiver(), p->value()));
 }
 
 void AccessorAssembler::HandleStoreICProtoHandler(
@@ -1674,10 +1673,9 @@ void AccessorAssembler::HandleStoreICProtoHandler(
       Goto(&store);
 
       BIND(&store);
-      Callable callable = CodeFactory::CallApiCallback(isolate());
       TNode<IntPtrT> argc = IntPtrConstant(1);
-      Return(CallStub(callable, context, callback, argc, data,
-                      api_holder.value(), p->receiver(), p->value()));
+      Return(CallApiCallback(context, callback, argc, data, api_holder.value(),
+                             p->receiver(), p->value()));
     }
 
     BIND(&if_store_global_proxy);
@@ -1989,7 +1987,7 @@ TNode<PropertyArray> AccessorAssembler::ExtendPropertiesBackingStore(
                    mode));
 
     TNode<PropertyArray> new_properties =
-        CAST(AllocatePropertyArray(new_capacity, mode));
+        AllocatePropertyArray(new_capacity, mode);
     var_new_properties = new_properties;
 
     FillPropertyArrayWithUndefined(new_properties, var_length.value(),
@@ -2831,8 +2829,7 @@ void AccessorAssembler::LoadIC_NoFeedback(const LoadICParameters* p,
 }
 
 void AccessorAssembler::LoadGlobalIC(TNode<HeapObject> maybe_feedback_vector,
-                                     const LazyNode<Smi>& lazy_smi_slot,
-                                     const LazyNode<UintPtrT>& lazy_slot,
+                                     const LazyNode<TaggedIndex>& lazy_slot,
                                      const LazyNode<Context>& lazy_context,
                                      const LazyNode<Name>& lazy_name,
                                      TypeofMode typeof_mode,
@@ -2842,24 +2839,27 @@ void AccessorAssembler::LoadGlobalIC(TNode<HeapObject> maybe_feedback_vector,
 
   GotoIf(IsUndefined(maybe_feedback_vector), &no_feedback);
   {
-    TNode<FeedbackVector> vector = CAST(maybe_feedback_vector);
-    TNode<UintPtrT> slot = lazy_slot();
-    LoadGlobalIC_TryPropertyCellCase(vector, slot, lazy_context, exit_point,
-                                     &try_handler, &miss);
+    TNode<TaggedIndex> slot = lazy_slot();
 
-    BIND(&try_handler);
-    LoadGlobalIC_TryHandlerCase(vector, slot, lazy_smi_slot, lazy_context,
-                                lazy_name, typeof_mode, exit_point, &miss);
-  }
+    {
+      TNode<FeedbackVector> vector = CAST(maybe_feedback_vector);
+      LoadGlobalIC_TryPropertyCellCase(vector, slot, lazy_context, exit_point,
+                                       &try_handler, &miss);
 
-  BIND(&miss);
-  {
-    Comment("LoadGlobalIC_MissCase");
-    TNode<Context> context = lazy_context();
-    TNode<Name> name = lazy_name();
-    exit_point->ReturnCallRuntime(Runtime::kLoadGlobalIC_Miss, context, name,
-                                  lazy_smi_slot(), maybe_feedback_vector,
-                                  SmiConstant(typeof_mode));
+      BIND(&try_handler);
+      LoadGlobalIC_TryHandlerCase(vector, slot, lazy_context, lazy_name,
+                                  typeof_mode, exit_point, &miss);
+    }
+
+    BIND(&miss);
+    {
+      Comment("LoadGlobalIC_MissCase");
+      TNode<Context> context = lazy_context();
+      TNode<Name> name = lazy_name();
+      exit_point->ReturnCallRuntime(Runtime::kLoadGlobalIC_Miss, context, name,
+                                    slot, maybe_feedback_vector,
+                                    SmiConstant(typeof_mode));
+    }
   }
 
   BIND(&no_feedback);
@@ -2875,7 +2875,7 @@ void AccessorAssembler::LoadGlobalIC(TNode<HeapObject> maybe_feedback_vector,
 }
 
 void AccessorAssembler::LoadGlobalIC_TryPropertyCellCase(
-    TNode<FeedbackVector> vector, TNode<UintPtrT> slot,
+    TNode<FeedbackVector> vector, TNode<TaggedIndex> slot,
     const LazyNode<Context>& lazy_context, ExitPoint* exit_point,
     Label* try_handler, Label* miss) {
   Comment("LoadGlobalIC_TryPropertyCellCase");
@@ -2912,10 +2912,9 @@ void AccessorAssembler::LoadGlobalIC_TryPropertyCellCase(
 }
 
 void AccessorAssembler::LoadGlobalIC_TryHandlerCase(
-    TNode<FeedbackVector> vector, TNode<UintPtrT> slot,
-    const LazyNode<Smi>& lazy_smi_slot, const LazyNode<Context>& lazy_context,
-    const LazyNode<Name>& lazy_name, TypeofMode typeof_mode,
-    ExitPoint* exit_point, Label* miss) {
+    TNode<FeedbackVector> vector, TNode<TaggedIndex> slot,
+    const LazyNode<Context>& lazy_context, const LazyNode<Name>& lazy_name,
+    TypeofMode typeof_mode, ExitPoint* exit_point, Label* miss) {
   Comment("LoadGlobalIC_TryHandlerCase");
 
   Label call_handler(this), non_smi(this);
@@ -2937,7 +2936,7 @@ void AccessorAssembler::LoadGlobalIC_TryHandlerCase(
       LoadContextElement(native_context, Context::EXTENSION_INDEX);
 
   LazyLoadICParameters p([=] { return context; }, receiver, lazy_name,
-                         lazy_smi_slot, vector, holder);
+                         [=] { return slot; }, vector, holder);
 
   HandleLoadICHandlerCase(&p, handler, miss, exit_point, ICMode::kGlobalIC,
                           on_nonexistent);
@@ -3233,7 +3232,7 @@ void AccessorAssembler::KeyedLoadICPolymorphicName(const LoadICParameters* p,
   TNode<Map> receiver_map = LoadReceiverMap(receiver);
   TNode<Name> name = CAST(p->name());
   TNode<FeedbackVector> vector = CAST(p->vector());
-  TNode<Smi> slot = p->slot();
+  TNode<TaggedIndex> slot = p->slot();
   TNode<Context> context = p->context();
 
   // When we get here, we know that the {name} matches the recorded
@@ -3634,7 +3633,7 @@ void AccessorAssembler::GenerateLoadIC() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3647,7 +3646,7 @@ void AccessorAssembler::GenerateLoadIC_Megamorphic() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3659,8 +3658,13 @@ void AccessorAssembler::GenerateLoadIC_Megamorphic() {
                     &if_handler, &var_handler, &miss);
 
   BIND(&if_handler);
-  LazyLoadICParameters p([=] { return context; }, receiver,
-                         [=] { return name; }, [=] { return slot; }, vector);
+  LazyLoadICParameters p(
+      // lazy_context
+      [=] { return context; }, receiver,
+      // lazy_name
+      [=] { return name; },
+      // lazy_slot
+      [=] { return slot; }, vector);
   HandleLoadICHandlerCase(&p, CAST(var_handler.value()), &miss, &direct_exit);
 
   BIND(&miss);
@@ -3673,7 +3677,7 @@ void AccessorAssembler::GenerateLoadIC_Noninlined() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<FeedbackVector> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3709,10 +3713,9 @@ void AccessorAssembler::GenerateLoadIC_NoFeedback() {
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<Smi> ic_kind = CAST(Parameter(Descriptor::kICKind));
 
-  LoadICParameters p(
-      context, receiver, name,
-      SmiConstant(static_cast<int>(FeedbackSlot::Invalid().ToInt())),
-      UndefinedConstant());
+  LoadICParameters p(context, receiver, name,
+                     TaggedIndexConstant(FeedbackSlot::Invalid().ToInt()),
+                     UndefinedConstant());
   LoadIC_NoFeedback(&p, ic_kind);
 }
 
@@ -3721,7 +3724,7 @@ void AccessorAssembler::GenerateLoadICTrampoline() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3733,7 +3736,7 @@ void AccessorAssembler::GenerateLoadICTrampoline_Megamorphic() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3755,17 +3758,15 @@ void AccessorAssembler::GenerateLoadGlobalIC(TypeofMode typeof_mode) {
   using Descriptor = LoadGlobalWithVectorDescriptor;
 
   TNode<Name> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   ExitPoint direct_exit(this);
   LoadGlobalIC(
       vector,
-      // lazy_smi_slot
-      [=] { return slot; },
       // lazy_slot
-      [=] { return Unsigned(SmiUntag(slot)); },
+      [=] { return slot; },
       // lazy_context
       [=] { return context; },
       // lazy_name
@@ -3776,7 +3777,7 @@ void AccessorAssembler::GenerateLoadGlobalICTrampoline(TypeofMode typeof_mode) {
   using Descriptor = LoadGlobalDescriptor;
 
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3790,7 +3791,7 @@ void AccessorAssembler::GenerateKeyedLoadIC() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3803,7 +3804,7 @@ void AccessorAssembler::GenerateKeyedLoadIC_Megamorphic() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3816,7 +3817,7 @@ void AccessorAssembler::GenerateKeyedLoadICTrampoline() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3829,7 +3830,7 @@ void AccessorAssembler::GenerateKeyedLoadICTrampoline_Megamorphic() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3842,7 +3843,7 @@ void AccessorAssembler::GenerateKeyedLoadIC_PolymorphicName() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<FeedbackVector> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3855,7 +3856,7 @@ void AccessorAssembler::GenerateStoreGlobalIC() {
 
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3868,7 +3869,7 @@ void AccessorAssembler::GenerateStoreGlobalICTrampoline() {
 
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3881,7 +3882,7 @@ void AccessorAssembler::GenerateStoreIC() {
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3895,7 +3896,7 @@ void AccessorAssembler::GenerateStoreICTrampoline() {
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3909,7 +3910,7 @@ void AccessorAssembler::GenerateKeyedStoreIC() {
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -3923,7 +3924,7 @@ void AccessorAssembler::GenerateKeyedStoreICTrampoline() {
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TNode<FeedbackVector> vector = LoadFeedbackVectorForStub();
 
@@ -3937,7 +3938,7 @@ void AccessorAssembler::GenerateStoreInArrayLiteralIC() {
   TNode<Object> array = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> index = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -4007,7 +4008,7 @@ void AccessorAssembler::GenerateCloneObjectIC() {
   using Descriptor = CloneObjectWithVectorDescriptor;
   TNode<Object> source = CAST(Parameter(Descriptor::kSource));
   TNode<Smi> flags = CAST(Parameter(Descriptor::kFlags));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> maybe_vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
   TVARIABLE(MaybeObject, var_handler);
@@ -4056,17 +4057,18 @@ void AccessorAssembler::GenerateCloneObjectIC() {
       GotoIf(IsEmptyFixedArray(source_properties), &allocate_object);
 
       // This IC requires that the source object has fast properties.
-      CSA_SLOW_ASSERT(this, IsPropertyArray(CAST(source_properties)));
-      TNode<IntPtrT> length = LoadPropertyArrayLength(
-          UncheckedCast<PropertyArray>(source_properties));
+      TNode<PropertyArray> source_property_array = CAST(source_properties);
+
+      TNode<IntPtrT> length = LoadPropertyArrayLength(source_property_array);
       GotoIf(IntPtrEqual(length, IntPtrConstant(0)), &allocate_object);
 
       auto mode = INTPTR_PARAMETERS;
-      var_properties = CAST(AllocatePropertyArray(length, mode));
-      FillPropertyArrayWithUndefined(var_properties.value(), IntPtrConstant(0),
-                                     length, mode);
-      CopyPropertyArrayValues(source_properties, var_properties.value(), length,
+      TNode<PropertyArray> property_array = AllocatePropertyArray(length, mode);
+      FillPropertyArrayWithUndefined(property_array, IntPtrConstant(0), length,
+                                     mode);
+      CopyPropertyArrayValues(source_property_array, property_array, length,
                               SKIP_WRITE_BARRIER, mode, DestroySource::kNo);
+      var_properties = property_array;
     }
 
     Goto(&allocate_object);
@@ -4171,7 +4173,7 @@ void AccessorAssembler::GenerateKeyedHasIC() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
@@ -4195,7 +4197,7 @@ void AccessorAssembler::GenerateKeyedHasIC_PolymorphicName() {
 
   TNode<Object> receiver = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<HeapObject> vector = CAST(Parameter(Descriptor::kVector));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
diff --git a/deps/v8/src/ic/accessor-assembler.h b/deps/v8/src/ic/accessor-assembler.h
index 3fb9a533ca..49b6694d6d 100644
--- a/deps/v8/src/ic/accessor-assembler.h
+++ b/deps/v8/src/ic/accessor-assembler.h
@@ -71,7 +71,7 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
   struct LoadICParameters {
     LoadICParameters(TNode<Context> context,
                      base::Optional<TNode<Object>> receiver, TNode<Object> name,
-                     TNode<Smi> slot, TNode<HeapObject> vector,
+                     TNode<TaggedIndex> slot, TNode<HeapObject> vector,
                      base::Optional<TNode<Object>> holder = base::nullopt)
         : context_(context),
           receiver_(receiver),
@@ -91,7 +91,7 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
     TNode<Context> context() const { return context_; }
     TNode<Object> receiver() const { return receiver_.value(); }
     TNode<Object> name() const { return name_; }
-    TNode<Smi> slot() const { return slot_; }
+    TNode<TaggedIndex> slot() const { return slot_; }
     TNode<HeapObject> vector() const { return vector_; }
     TNode<Object> holder() const { return holder_.value(); }
     bool receiver_is_null() const { return !receiver_.has_value(); }
@@ -100,14 +100,14 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
     TNode<Context> context_;
     base::Optional<TNode<Object>> receiver_;
     TNode<Object> name_;
-    TNode<Smi> slot_;
+    TNode<TaggedIndex> slot_;
     TNode<HeapObject> vector_;
     base::Optional<TNode<Object>> holder_;
   };
 
   struct LazyLoadICParameters {
     LazyLoadICParameters(LazyNode<Context> context, TNode<Object> receiver,
-                         LazyNode<Object> name, LazyNode<Smi> slot,
+                         LazyNode<Object> name, LazyNode<TaggedIndex> slot,
                          TNode<HeapObject> vector,
                          base::Optional<TNode<Object>> holder = base::nullopt)
         : context_(context),
@@ -129,7 +129,7 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
     TNode<Context> context() const { return context_(); }
     TNode<Object> receiver() const { return receiver_; }
     TNode<Object> name() const { return name_(); }
-    TNode<Smi> slot() const { return slot_(); }
+    TNode<TaggedIndex> slot() const { return slot_(); }
     TNode<HeapObject> vector() const { return vector_; }
     TNode<Object> holder() const { return holder_; }
 
@@ -137,14 +137,13 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
     LazyNode<Context> context_;
     TNode<Object> receiver_;
     LazyNode<Object> name_;
-    LazyNode<Smi> slot_;
+    LazyNode<TaggedIndex> slot_;
     TNode<HeapObject> vector_;
     TNode<Object> holder_;
   };
 
   void LoadGlobalIC(TNode<HeapObject> maybe_feedback_vector,
-                    const LazyNode<Smi>& lazy_smi_slot,
-                    const LazyNode<UintPtrT>& lazy_slot,
+                    const LazyNode<TaggedIndex>& lazy_slot,
                     const LazyNode<Context>& lazy_context,
                     const LazyNode<Name>& lazy_name, TypeofMode typeof_mode,
                     ExitPoint* exit_point);
@@ -162,8 +161,8 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
   struct StoreICParameters : public LoadICParameters {
     StoreICParameters(TNode<Context> context,
                       base::Optional<TNode<Object>> receiver,
-                      TNode<Object> name, TNode<Object> value, TNode<Smi> slot,
-                      TNode<HeapObject> vector)
+                      TNode<Object> name, TNode<Object> value,
+                      TNode<TaggedIndex> slot, TNode<HeapObject> vector)
         : LoadICParameters(context, receiver, name, slot, vector),
           value_(value) {}
 
@@ -243,9 +242,12 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
   // IC dispatcher behavior.
 
   // Checks monomorphic case. Returns {feedback} entry of the vector.
-  TNode<MaybeObject> TryMonomorphicCase(
-      TNode<Smi> slot, TNode<FeedbackVector> vector, TNode<Map> receiver_map,
-      Label* if_handler, TVariable<MaybeObject>* var_handler, Label* if_miss);
+  TNode<MaybeObject> TryMonomorphicCase(TNode<TaggedIndex> slot,
+                                        TNode<FeedbackVector> vector,
+                                        TNode<Map> receiver_map,
+                                        Label* if_handler,
+                                        TVariable<MaybeObject>* var_handler,
+                                        Label* if_miss);
   void HandlePolymorphicCase(TNode<Map> receiver_map,
                              TNode<WeakFixedArray> feedback, Label* if_handler,
                              TVariable<MaybeObject>* var_handler,
@@ -309,14 +311,13 @@ class V8_EXPORT_PRIVATE AccessorAssembler : public CodeStubAssembler {
   // LoadGlobalIC implementation.
 
   void LoadGlobalIC_TryPropertyCellCase(TNode<FeedbackVector> vector,
-                                        TNode<UintPtrT> slot,
+                                        TNode<TaggedIndex> slot,
                                         const LazyNode<Context>& lazy_context,
                                         ExitPoint* exit_point,
                                         Label* try_handler, Label* miss);
 
   void LoadGlobalIC_TryHandlerCase(TNode<FeedbackVector> vector,
-                                   TNode<UintPtrT> slot,
-                                   const LazyNode<Smi>& lazy_smi_slot,
+                                   TNode<TaggedIndex> slot,
                                    const LazyNode<Context>& lazy_context,
                                    const LazyNode<Name>& lazy_name,
                                    TypeofMode typeof_mode,
diff --git a/deps/v8/src/ic/ic.cc b/deps/v8/src/ic/ic.cc
index 5f6ff322d2..b508a20f80 100644
--- a/deps/v8/src/ic/ic.cc
+++ b/deps/v8/src/ic/ic.cc
@@ -96,10 +96,7 @@ void IC::TraceIC(const char* type, Handle<Object> name, State old_state,
                  State new_state) {
   if (V8_LIKELY(!TracingFlags::is_ic_stats_enabled())) return;
 
-  Map map;
-  if (!receiver_map().is_null()) {
-    map = *receiver_map();
-  }
+  Handle<Map> map = receiver_map();  // Might be empty.
 
   const char* modifier = "";
   if (state() == NO_FEEDBACK) {
@@ -116,7 +113,7 @@ void IC::TraceIC(const char* type, Handle<Object> name, State old_state,
 
   if (!(TracingFlags::ic_stats.load(std::memory_order_relaxed) &
         v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
-    LOG(isolate(), ICEvent(type, keyed_prefix, map, *name,
+    LOG(isolate(), ICEvent(type, keyed_prefix, map, name,
                            TransitionMarkFromState(old_state),
                            TransitionMarkFromState(new_state), modifier,
                            slow_stub_reason_));
@@ -125,6 +122,8 @@ void IC::TraceIC(const char* type, Handle<Object> name, State old_state,
 
   JavaScriptFrameIterator it(isolate());
   JavaScriptFrame* frame = it.frame();
+
+  DisallowHeapAllocation no_gc;
   JSFunction function = frame->function();
 
   ICStats::instance()->Begin();
@@ -150,11 +149,13 @@ void IC::TraceIC(const char* type, Handle<Object> name, State old_state,
   ic_info.state += TransitionMarkFromState(new_state);
   ic_info.state += modifier;
   ic_info.state += ")";
-  ic_info.map = reinterpret_cast<void*>(map.ptr());
   if (!map.is_null()) {
-    ic_info.is_dictionary_map = map.is_dictionary_map();
-    ic_info.number_of_own_descriptors = map.NumberOfOwnDescriptors();
-    ic_info.instance_type = std::to_string(map.instance_type());
+    ic_info.map = reinterpret_cast<void*>(map->ptr());
+    ic_info.is_dictionary_map = map->is_dictionary_map();
+    ic_info.number_of_own_descriptors = map->NumberOfOwnDescriptors();
+    ic_info.instance_type = std::to_string(map->instance_type());
+  } else {
+    ic_info.map = nullptr;
   }
   // TODO(lpy) Add name as key field in ICStats.
   ICStats::instance()->End();
@@ -426,6 +427,14 @@ MaybeHandle<Object> LoadIC::Load(Handle<Object> object, Handle<Name> name,
     if (name->IsPrivateName() && !it.IsFound()) {
       Handle<String> name_string(
           String::cast(Symbol::cast(*name).description()), isolate());
+      if (name->IsPrivateBrand()) {
+        Handle<String> class_name =
+            (name_string->length() == 0)
+                ? isolate()->factory()->anonymous_string()
+                : name_string;
+        return TypeError(MessageTemplate::kInvalidPrivateBrand, object,
+                         class_name);
+      }
       return TypeError(MessageTemplate::kInvalidPrivateMemberRead, object,
                        name_string);
     }
@@ -1485,11 +1494,10 @@ MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
   // TODO(verwaest): Let SetProperty do the migration, since storing a property
   // might deprecate the current map again, if value does not fit.
   if (MigrateDeprecated(isolate(), object)) {
-    Handle<Object> result;
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate(), result, Object::SetProperty(isolate(), object, name, value),
-        Object);
-    return result;
+    LookupIterator::Key key(isolate(), name);
+    LookupIterator it(isolate(), object, key);
+    MAYBE_RETURN_NULL(Object::SetProperty(&it, value, StoreOrigin::kNamed));
+    return value;
   }
 
   bool use_ic = (state() != NO_FEEDBACK) && FLAG_use_ic;
@@ -2238,7 +2246,7 @@ RUNTIME_FUNCTION(Runtime_LoadIC_Miss) {
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> receiver = args.at(0);
   Handle<Name> key = args.at<Name>(1);
-  Handle<Smi> slot = args.at<Smi>(2);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(2);
   Handle<FeedbackVector> vector = args.at<FeedbackVector>(3);
   FeedbackSlot vector_slot = FeedbackVector::ToSlot(slot->value());
 
@@ -2290,7 +2298,7 @@ RUNTIME_FUNCTION(Runtime_LoadGlobalIC_Miss) {
   // Runtime functions don't follow the IC's calling convention.
   Handle<JSGlobalObject> global = isolate->global_object();
   Handle<String> name = args.at<String>(0);
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(2);
   CONVERT_INT32_ARG_CHECKED(typeof_value, 3);
   TypeofMode typeof_mode = static_cast<TypeofMode>(typeof_value);
@@ -2318,7 +2326,7 @@ RUNTIME_FUNCTION(Runtime_LoadGlobalIC_Slow) {
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
 
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<FeedbackVector> vector = args.at<FeedbackVector>(2);
   FeedbackSlot vector_slot = FeedbackVector::ToSlot(slot->value());
   FeedbackSlotKind kind = vector->GetKind(vector_slot);
@@ -2335,7 +2343,7 @@ RUNTIME_FUNCTION(Runtime_KeyedLoadIC_Miss) {
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> receiver = args.at(0);
   Handle<Object> key = args.at(1);
-  Handle<Smi> slot = args.at<Smi>(2);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(2);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(3);
 
   Handle<FeedbackVector> vector = Handle<FeedbackVector>();
@@ -2354,7 +2362,7 @@ RUNTIME_FUNCTION(Runtime_StoreIC_Miss) {
   DCHECK_EQ(5, args.length());
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> value = args.at(0);
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(2);
   Handle<Object> receiver = args.at(3);
   Handle<Name> key = args.at<Name>(4);
@@ -2384,7 +2392,7 @@ RUNTIME_FUNCTION(Runtime_StoreGlobalIC_Miss) {
   DCHECK_EQ(4, args.length());
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> value = args.at(0);
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<FeedbackVector> vector = args.at<FeedbackVector>(2);
   Handle<Name> key = args.at<Name>(3);
 
@@ -2420,7 +2428,7 @@ RUNTIME_FUNCTION(Runtime_StoreGlobalIC_Slow) {
 
 #ifdef DEBUG
   {
-    Handle<Smi> slot = args.at<Smi>(1);
+    Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
     Handle<FeedbackVector> vector = args.at<FeedbackVector>(2);
     FeedbackSlot vector_slot = FeedbackVector::ToSlot(slot->value());
     FeedbackSlotKind slot_kind = vector->GetKind(vector_slot);
@@ -2468,7 +2476,7 @@ RUNTIME_FUNCTION(Runtime_KeyedStoreIC_Miss) {
   DCHECK_EQ(5, args.length());
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> value = args.at(0);
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(2);
   Handle<Object> receiver = args.at(3);
   Handle<Object> key = args.at(4);
@@ -2510,7 +2518,7 @@ RUNTIME_FUNCTION(Runtime_StoreInArrayLiteralIC_Miss) {
   DCHECK_EQ(5, args.length());
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> value = args.at(0);
-  Handle<Smi> slot = args.at<Smi>(1);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(1);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(2);
   Handle<Object> receiver = args.at(3);
   Handle<Object> key = args.at(4);
@@ -2558,7 +2566,7 @@ RUNTIME_FUNCTION(Runtime_ElementsTransitionAndStoreIC_Miss) {
   Handle<Object> key = args.at(1);
   Handle<Object> value = args.at(2);
   Handle<Map> map = args.at<Map>(3);
-  Handle<Smi> slot = args.at<Smi>(4);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(4);
   Handle<FeedbackVector> vector = args.at<FeedbackVector>(5);
   FeedbackSlot vector_slot = FeedbackVector::ToSlot(slot->value());
   FeedbackSlotKind kind = vector->GetKind(vector_slot);
@@ -2681,10 +2689,11 @@ RUNTIME_FUNCTION(Runtime_CloneObjectIC_Miss) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   Handle<Object> source = args.at<Object>(0);
-  int flags = args.smi_at(1);
+  CONVERT_SMI_ARG_CHECKED(flags, 1);
 
   if (!MigrateDeprecated(isolate, source)) {
-    FeedbackSlot slot = FeedbackVector::ToSlot(args.smi_at(2));
+    CONVERT_TAGGED_INDEX_ARG_CHECKED(index, 2);
+    FeedbackSlot slot = FeedbackVector::ToSlot(index);
     Handle<HeapObject> maybe_vector = args.at<HeapObject>(3);
     if (maybe_vector->IsFeedbackVector()) {
       FeedbackNexus nexus(Handle<FeedbackVector>::cast(maybe_vector), slot);
@@ -2768,7 +2777,7 @@ RUNTIME_FUNCTION(Runtime_LoadPropertyWithInterceptor) {
 
   if (it.IsFound()) return *result;
 
-  Handle<Smi> slot = args.at<Smi>(3);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(3);
   Handle<FeedbackVector> vector = args.at<FeedbackVector>(4);
   FeedbackSlot vector_slot = FeedbackVector::ToSlot(slot->value());
   FeedbackSlotKind slot_kind = vector->GetKind(vector_slot);
@@ -2859,7 +2868,7 @@ RUNTIME_FUNCTION(Runtime_KeyedHasIC_Miss) {
   // Runtime functions don't follow the IC's calling convention.
   Handle<Object> receiver = args.at(0);
   Handle<Object> key = args.at(1);
-  Handle<Smi> slot = args.at<Smi>(2);
+  Handle<TaggedIndex> slot = args.at<TaggedIndex>(2);
   Handle<HeapObject> maybe_vector = args.at<HeapObject>(3);
 
   Handle<FeedbackVector> vector = Handle<FeedbackVector>();
diff --git a/deps/v8/src/ic/keyed-store-generic.cc b/deps/v8/src/ic/keyed-store-generic.cc
index 5d8ea71bcd..88a66e1760 100644
--- a/deps/v8/src/ic/keyed-store-generic.cc
+++ b/deps/v8/src/ic/keyed-store-generic.cc
@@ -617,9 +617,9 @@ void KeyedStoreGenericAssembler::LookupPropertyOnPrototypeChain(
       Label found(this), found_fast(this), found_dict(this), found_global(this);
       TVARIABLE(HeapObject, var_meta_storage);
       TVARIABLE(IntPtrT, var_entry);
-      TryLookupProperty(CAST(holder), holder_map, instance_type, name,
-                        &found_fast, &found_dict, &found_global,
-                        &var_meta_storage, &var_entry, &next_proto, bailout);
+      TryLookupProperty(holder, holder_map, instance_type, name, &found_fast,
+                        &found_dict, &found_global, &var_meta_storage,
+                        &var_entry, &next_proto, bailout);
       BIND(&found_fast);
       {
         TNode<DescriptorArray> descriptors = CAST(var_meta_storage.value());
@@ -920,8 +920,7 @@ void KeyedStoreGenericAssembler::EmitGenericPropertyStore(
       GotoIf(IsFunctionTemplateInfoMap(setter_map), slow);
       GotoIfNot(IsCallableMap(setter_map), &not_callable);
 
-      Callable callable = CodeFactory::Call(isolate());
-      CallJS(callable, p->context(), setter, receiver, p->value());
+      Call(p->context(), setter, receiver, p->value());
       exit_point->Return(p->value());
 
       BIND(&not_callable);
@@ -1054,7 +1053,7 @@ void KeyedStoreGenericAssembler::StoreIC_NoFeedback() {
   TNode<Object> receiver_maybe_smi = CAST(Parameter(Descriptor::kReceiver));
   TNode<Object> name = CAST(Parameter(Descriptor::kName));
   TNode<Object> value = CAST(Parameter(Descriptor::kValue));
-  TNode<Smi> slot = CAST(Parameter(Descriptor::kSlot));
+  TNode<TaggedIndex> slot = CAST(Parameter(Descriptor::kSlot));
   TNode<Context> context = CAST(Parameter(Descriptor::kContext));
 
   Label miss(this, Label::kDeferred), store_property(this);
diff --git a/deps/v8/src/ic/stub-cache.h b/deps/v8/src/ic/stub-cache.h
index dc3317588d..ec026bcfcf 100644
--- a/deps/v8/src/ic/stub-cache.h
+++ b/deps/v8/src/ic/stub-cache.h
@@ -78,15 +78,12 @@ class V8_EXPORT_PRIVATE StubCache {
 
   Isolate* isolate() { return isolate_; }
 
-  // Ideally we would set kCacheIndexShift to Name::kHashShift, such that
-  // the bit field inside the hash field gets shifted out implicitly. However,
-  // sizeof(Entry) needs to be a multiple of 1 << kCacheIndexShift, and it
-  // isn't clear whether letting one bit of the bit field leak into the index
-  // computation is bad enough to warrant an additional shift to get rid of it.
-  static const int kCacheIndexShift = 2;
-  // The purpose of the static assert is to make us reconsider this choice
-  // if the bit field ever grows even more.
-  STATIC_ASSERT(kCacheIndexShift == Name::kHashShift - 1);
+  // Setting kCacheIndexShift to Name::kHashShift is convenient because it
+  // causes the bit field inside the hash field to get shifted out implicitly.
+  // Note that kCacheIndexShift must not get too large, because
+  // sizeof(Entry) needs to be a multiple of 1 << kCacheIndexShift (see
+  // the STATIC_ASSERT below, in {entry(...)}).
+  static const int kCacheIndexShift = Name::kHashShift;
 
   static const int kPrimaryTableBits = 11;
   static const int kPrimaryTableSize = (1 << kPrimaryTableBits);
diff --git a/deps/v8/src/init/bootstrapper.cc b/deps/v8/src/init/bootstrapper.cc
index 93d19a42a9..22d33eaf91 100644
--- a/deps/v8/src/init/bootstrapper.cc
+++ b/deps/v8/src/init/bootstrapper.cc
@@ -9,6 +9,7 @@
 #include "src/base/ieee754.h"
 #include "src/builtins/accessors.h"
 #include "src/codegen/compiler.h"
+#include "src/common/globals.h"
 #include "src/debug/debug.h"
 #include "src/execution/isolate-inl.h"
 #include "src/execution/microtask-queue.h"
@@ -443,6 +444,7 @@ V8_NOINLINE Handle<JSFunction> SimpleCreateFunction(Isolate* isolate,
                                                     Builtins::Name call,
                                                     int len, bool adapt) {
   DCHECK(Builtins::HasJSLinkage(call));
+  name = String::Flatten(isolate, name, AllocationType::kOld);
   NewFunctionArgs args = NewFunctionArgs::ForBuiltinWithoutPrototype(
       name, call, LanguageMode::kStrict);
   Handle<JSFunction> fun = isolate->factory()->NewFunction(args);
@@ -1551,9 +1553,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         isolate_, isolate_->initial_object_prototype(), "toString",
         Builtins::kObjectPrototypeToString, 0, true);
     native_context()->set_object_to_string(*object_to_string);
-    SimpleInstallFunction(isolate_, isolate_->initial_object_prototype(),
-                          "valueOf", Builtins::kObjectPrototypeValueOf, 0,
-                          true);
+    Handle<JSFunction> object_value_of = SimpleInstallFunction(
+        isolate_, isolate_->initial_object_prototype(), "valueOf",
+        Builtins::kObjectPrototypeValueOf, 0, true);
+    native_context()->set_object_value_of_function(*object_value_of);
 
     SimpleInstallGetterSetter(
         isolate_, isolate_->initial_object_prototype(), factory->proto_string(),
@@ -4305,44 +4308,46 @@ void Genesis::InitializeGlobal_harmony_weak_refs() {
   Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
 
   {
-    // Create %FinalizationGroupPrototype%
-    Handle<String> finalization_group_name =
-        factory->NewStringFromStaticChars("FinalizationGroup");
-    Handle<JSObject> finalization_group_prototype = factory->NewJSObject(
+    // Create %FinalizationRegistryPrototype%
+    Handle<String> finalization_registry_name =
+        factory->NewStringFromStaticChars("FinalizationRegistry");
+    Handle<JSObject> finalization_registry_prototype = factory->NewJSObject(
         isolate()->object_function(), AllocationType::kOld);
 
-    // Create %FinalizationGroup%
-    Handle<JSFunction> finalization_group_fun = CreateFunction(
-        isolate(), finalization_group_name, JS_FINALIZATION_GROUP_TYPE,
-        JSFinalizationGroup::kHeaderSize, 0, finalization_group_prototype,
-        Builtins::kFinalizationGroupConstructor);
+    // Create %FinalizationRegistry%
+    Handle<JSFunction> finalization_registry_fun = CreateFunction(
+        isolate(), finalization_registry_name, JS_FINALIZATION_REGISTRY_TYPE,
+        JSFinalizationRegistry::kHeaderSize, 0, finalization_registry_prototype,
+        Builtins::kFinalizationRegistryConstructor);
     InstallWithIntrinsicDefaultProto(
-        isolate(), finalization_group_fun,
-        Context::JS_FINALIZATION_GROUP_FUNCTION_INDEX);
+        isolate(), finalization_registry_fun,
+        Context::JS_FINALIZATION_REGISTRY_FUNCTION_INDEX);
 
-    finalization_group_fun->shared().DontAdaptArguments();
-    finalization_group_fun->shared().set_length(1);
+    finalization_registry_fun->shared().DontAdaptArguments();
+    finalization_registry_fun->shared().set_length(1);
 
     // Install the "constructor" property on the prototype.
-    JSObject::AddProperty(isolate(), finalization_group_prototype,
-                          factory->constructor_string(), finalization_group_fun,
-                          DONT_ENUM);
+    JSObject::AddProperty(isolate(), finalization_registry_prototype,
+                          factory->constructor_string(),
+                          finalization_registry_fun, DONT_ENUM);
 
-    InstallToStringTag(isolate(), finalization_group_prototype,
-                       finalization_group_name);
+    InstallToStringTag(isolate(), finalization_registry_prototype,
+                       finalization_registry_name);
 
-    JSObject::AddProperty(isolate(), global, finalization_group_name,
-                          finalization_group_fun, DONT_ENUM);
+    JSObject::AddProperty(isolate(), global, finalization_registry_name,
+                          finalization_registry_fun, DONT_ENUM);
 
-    SimpleInstallFunction(isolate(), finalization_group_prototype, "register",
-                          Builtins::kFinalizationGroupRegister, 2, false);
+    SimpleInstallFunction(isolate(), finalization_registry_prototype,
+                          "register", Builtins::kFinalizationRegistryRegister,
+                          2, false);
 
-    SimpleInstallFunction(isolate(), finalization_group_prototype, "unregister",
-                          Builtins::kFinalizationGroupUnregister, 1, false);
+    SimpleInstallFunction(isolate(), finalization_registry_prototype,
+                          "unregister",
+                          Builtins::kFinalizationRegistryUnregister, 1, false);
 
-    SimpleInstallFunction(isolate(), finalization_group_prototype,
+    SimpleInstallFunction(isolate(), finalization_registry_prototype,
                           "cleanupSome",
-                          Builtins::kFinalizationGroupCleanupSome, 0, false);
+                          Builtins::kFinalizationRegistryCleanupSome, 0, false);
   }
   {
     // Create %WeakRefPrototype%
@@ -4381,7 +4386,7 @@ void Genesis::InitializeGlobal_harmony_weak_refs() {
   }
 
   {
-    // Create cleanup iterator for JSFinalizationGroup.
+    // Create cleanup iterator for JSFinalizationRegistry.
     Handle<JSObject> iterator_prototype(
         native_context()->initial_iterator_prototype(), isolate());
 
@@ -4390,17 +4395,17 @@ void Genesis::InitializeGlobal_harmony_weak_refs() {
     JSObject::ForceSetPrototype(cleanup_iterator_prototype, iterator_prototype);
 
     InstallToStringTag(isolate(), cleanup_iterator_prototype,
-                       "FinalizationGroup Cleanup Iterator");
+                       "FinalizationRegistry Cleanup Iterator");
 
     SimpleInstallFunction(isolate(), cleanup_iterator_prototype, "next",
-                          Builtins::kFinalizationGroupCleanupIteratorNext, 0,
+                          Builtins::kFinalizationRegistryCleanupIteratorNext, 0,
                           true);
     Handle<Map> cleanup_iterator_map =
-        factory->NewMap(JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE,
-                        JSFinalizationGroupCleanupIterator::kHeaderSize);
+        factory->NewMap(JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE,
+                        JSFinalizationRegistryCleanupIterator::kHeaderSize);
     Map::SetPrototype(isolate(), cleanup_iterator_map,
                       cleanup_iterator_prototype);
-    native_context()->set_js_finalization_group_cleanup_iterator_map(
+    native_context()->set_js_finalization_registry_cleanup_iterator_map(
         *cleanup_iterator_map);
   }
 }
@@ -4992,7 +4997,7 @@ bool Genesis::InstallSpecialObjects(Isolate* isolate,
     WasmJs::Install(isolate, true);
   } else if (FLAG_validate_asm) {
     // Install the internal data structures only; these are needed for asm.js
-    // translated to WASM to work correctly.
+    // translated to Wasm to work correctly.
     WasmJs::Install(isolate, false);
   }
 
diff --git a/deps/v8/src/init/heap-symbols.h b/deps/v8/src/init/heap-symbols.h
index 7131b80860..d56cc4b0cd 100644
--- a/deps/v8/src/init/heap-symbols.h
+++ b/deps/v8/src/init/heap-symbols.h
@@ -359,6 +359,7 @@
   V(_, strict_function_transition_symbol)             \
   V(_, wasm_exception_tag_symbol)                     \
   V(_, wasm_exception_values_symbol)                  \
+  V(_, wasm_uncatchable_symbol)                       \
   V(_, uninitialized_symbol)
 
 #define PUBLIC_SYMBOL_LIST_GENERATOR(V, _)          \
diff --git a/deps/v8/src/inspector/custom-preview.cc b/deps/v8/src/inspector/custom-preview.cc
index aa5652a42d..393e0f15c5 100644
--- a/deps/v8/src/inspector/custom-preview.cc
+++ b/deps/v8/src/inspector/custom-preview.cc
@@ -116,13 +116,13 @@ bool substituteObjectTags(int sessionId, const String16& groupName,
     protocol::Response response =
         injectedScript->wrapObject(originValue, groupName, WrapMode::kNoPreview,
                                    configValue, maxDepth - 1, &wrapper);
-    if (!response.isSuccess() || !wrapper) {
+    if (!response.IsSuccess() || !wrapper) {
       reportError(context, tryCatch, "cannot wrap value");
       return false;
     }
-    std::vector<uint8_t> cbor = std::move(*wrapper).TakeSerialized();
     std::vector<uint8_t> json;
-    v8_crdtp::json::ConvertCBORToJSON(v8_crdtp::SpanFrom(cbor), &json);
+    v8_crdtp::json::ConvertCBORToJSON(v8_crdtp::SpanFrom(wrapper->Serialize()),
+                                      &json);
     v8::Local<v8::Value> jsonWrapper;
     v8_inspector::StringView serialized(json.data(), json.size());
     if (!v8::JSON::Parse(context, toV8String(isolate, serialized))
diff --git a/deps/v8/src/inspector/injected-script.cc b/deps/v8/src/inspector/injected-script.cc
index fb3fa9b069..734c70141d 100644
--- a/deps/v8/src/inspector/injected-script.cc
+++ b/deps/v8/src/inspector/injected-script.cc
@@ -179,7 +179,7 @@ class InjectedScript::ProtocolPromiseHandler {
     if (!session) return;
     InjectedScript::ContextScope scope(session, m_executionContextId);
     Response response = scope.initialize();
-    if (!response.isSuccess()) return;
+    if (!response.IsSuccess()) return;
 
     std::unique_ptr<EvaluateCallback> callback =
         scope.injectedScript()->takeEvaluateCallback(m_callback);
@@ -210,7 +210,7 @@ class InjectedScript::ProtocolPromiseHandler {
     std::unique_ptr<protocol::Runtime::RemoteObject> wrappedValue;
     response = scope.injectedScript()->wrapObject(result, m_objectGroup,
                                                   m_wrapMode, &wrappedValue);
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
@@ -224,14 +224,14 @@ class InjectedScript::ProtocolPromiseHandler {
     if (!session) return;
     InjectedScript::ContextScope scope(session, m_executionContextId);
     Response response = scope.initialize();
-    if (!response.isSuccess()) return;
+    if (!response.IsSuccess()) return;
     std::unique_ptr<EvaluateCallback> callback =
         scope.injectedScript()->takeEvaluateCallback(m_callback);
     if (!callback) return;
     std::unique_ptr<protocol::Runtime::RemoteObject> wrappedValue;
     response = scope.injectedScript()->wrapObject(result, m_objectGroup,
                                                   m_wrapMode, &wrappedValue);
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
@@ -251,7 +251,7 @@ class InjectedScript::ProtocolPromiseHandler {
           exceptionDetails;
       response = scope.injectedScript()->createExceptionDetails(
           message, exception, m_objectGroup, &exceptionDetails);
-      if (!response.isSuccess()) {
+      if (!response.IsSuccess()) {
         callback->sendFailure(response);
         return;
       }
@@ -297,7 +297,7 @@ class InjectedScript::ProtocolPromiseHandler {
             .build();
     response = scope.injectedScript()->addExceptionToDetails(
         result, exceptionDetails.get(), m_objectGroup);
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
@@ -315,11 +315,11 @@ class InjectedScript::ProtocolPromiseHandler {
     if (!session) return;
     InjectedScript::ContextScope scope(session, m_executionContextId);
     Response response = scope.initialize();
-    if (!response.isSuccess()) return;
+    if (!response.IsSuccess()) return;
     std::unique_ptr<EvaluateCallback> callback =
         scope.injectedScript()->takeEvaluateCallback(m_callback);
     if (!callback) return;
-    callback->sendFailure(Response::Error("Promise was collected"));
+    callback->sendFailure(Response::ServerError("Promise was collected"));
   }
 
   V8InspectorImpl* m_inspector;
@@ -380,60 +380,59 @@ Response InjectedScript::getProperties(
             .setEnumerable(mirror.enumerable)
             .setIsOwn(mirror.isOwn)
             .build();
-    Response response;
     std::unique_ptr<RemoteObject> remoteObject;
     if (mirror.value) {
-      response = wrapObjectMirror(*mirror.value, groupName, wrapMode,
-                                  v8::MaybeLocal<v8::Value>(),
-                                  kMaxCustomPreviewDepth, &remoteObject);
-      if (!response.isSuccess()) return response;
+      Response response = wrapObjectMirror(
+          *mirror.value, groupName, wrapMode, v8::MaybeLocal<v8::Value>(),
+          kMaxCustomPreviewDepth, &remoteObject);
+      if (!response.IsSuccess()) return response;
       descriptor->setValue(std::move(remoteObject));
       descriptor->setWritable(mirror.writable);
     }
     if (mirror.getter) {
-      response =
+      Response response =
           mirror.getter->buildRemoteObject(context, wrapMode, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response =
           bindRemoteObjectIfNeeded(sessionId, context, mirror.getter->v8Value(),
                                    groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setGet(std::move(remoteObject));
     }
     if (mirror.setter) {
-      response =
+      Response response =
           mirror.setter->buildRemoteObject(context, wrapMode, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response =
           bindRemoteObjectIfNeeded(sessionId, context, mirror.setter->v8Value(),
                                    groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setSet(std::move(remoteObject));
     }
     if (mirror.symbol) {
-      response =
+      Response response =
           mirror.symbol->buildRemoteObject(context, wrapMode, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response =
           bindRemoteObjectIfNeeded(sessionId, context, mirror.symbol->v8Value(),
                                    groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setSymbol(std::move(remoteObject));
     }
     if (mirror.exception) {
-      response =
+      Response response =
           mirror.exception->buildRemoteObject(context, wrapMode, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response = bindRemoteObjectIfNeeded(sessionId, context,
                                           mirror.exception->v8Value(),
                                           groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setValue(std::move(remoteObject));
       descriptor->setWasThrown(true);
     }
     (*properties)->emplace_back(std::move(descriptor));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response InjectedScript::getInternalAndPrivateProperties(
@@ -445,7 +444,7 @@ Response InjectedScript::getInternalAndPrivateProperties(
   *internalProperties = std::make_unique<Array<InternalPropertyDescriptor>>();
   *privateProperties = std::make_unique<Array<PrivatePropertyDescriptor>>();
 
-  if (!value->IsObject()) return Response::OK();
+  if (!value->IsObject()) return Response::Success();
 
   v8::Local<v8::Object> value_obj = value.As<v8::Object>();
 
@@ -458,11 +457,11 @@ Response InjectedScript::getInternalAndPrivateProperties(
     std::unique_ptr<RemoteObject> remoteObject;
     Response response = internalProperty.value->buildRemoteObject(
         m_context->context(), WrapMode::kNoPreview, &remoteObject);
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
     response = bindRemoteObjectIfNeeded(sessionId, context,
                                         internalProperty.value->v8Value(),
                                         groupName, remoteObject.get());
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
     (*internalProperties)
         ->emplace_back(InternalPropertyDescriptor::create()
                            .setName(internalProperty.name)
@@ -479,50 +478,53 @@ Response InjectedScript::getInternalAndPrivateProperties(
             .build();
 
     std::unique_ptr<RemoteObject> remoteObject;
-    Response response;
     DCHECK((privateProperty.getter || privateProperty.setter) ^
            (!!privateProperty.value));
     if (privateProperty.value) {
-      response = privateProperty.value->buildRemoteObject(
+      Response response = privateProperty.value->buildRemoteObject(
           context, WrapMode::kNoPreview, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response = bindRemoteObjectIfNeeded(sessionId, context,
                                           privateProperty.value->v8Value(),
                                           groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setValue(std::move(remoteObject));
     }
 
     if (privateProperty.getter) {
-      response = privateProperty.getter->buildRemoteObject(
+      Response response = privateProperty.getter->buildRemoteObject(
           context, WrapMode::kNoPreview, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response = bindRemoteObjectIfNeeded(sessionId, context,
                                           privateProperty.getter->v8Value(),
                                           groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setGet(std::move(remoteObject));
     }
 
     if (privateProperty.setter) {
-      response = privateProperty.setter->buildRemoteObject(
+      Response response = privateProperty.setter->buildRemoteObject(
           context, WrapMode::kNoPreview, &remoteObject);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       response = bindRemoteObjectIfNeeded(sessionId, context,
                                           privateProperty.setter->v8Value(),
                                           groupName, remoteObject.get());
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       descriptor->setSet(std::move(remoteObject));
     }
 
     (*privateProperties)->emplace_back(std::move(descriptor));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 void InjectedScript::releaseObject(const String16& objectId) {
+  std::vector<uint8_t> cbor;
+  v8_crdtp::json::ConvertJSONToCBOR(
+      v8_crdtp::span<uint16_t>(objectId.characters16(), objectId.length()),
+      &cbor);
   std::unique_ptr<protocol::Value> parsedObjectId =
-      protocol::StringUtil::parseJSON(objectId);
+      protocol::Value::parseBinary(cbor.data(), cbor.size());
   if (!parsedObjectId) return;
   protocol::DictionaryValue* object =
       protocol::DictionaryValue::cast(parsedObjectId.get());
@@ -560,11 +562,11 @@ Response InjectedScript::wrapObjectMirror(
   v8::Local<v8::Context> context = m_context->context();
   v8::Context::Scope contextScope(context);
   Response response = mirror.buildRemoteObject(context, wrapMode, result);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   v8::Local<v8::Value> value = mirror.v8Value();
   response = bindRemoteObjectIfNeeded(sessionId, context, value, groupName,
                                       result->get());
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (customPreviewEnabled && value->IsObject()) {
     std::unique_ptr<protocol::Runtime::CustomPreview> customPreview;
     generateCustomPreview(sessionId, groupName, value.As<v8::Object>(),
@@ -572,7 +574,7 @@ Response InjectedScript::wrapObjectMirror(
                           &customPreview);
     if (customPreview) (*result)->setCustomPreview(std::move(customPreview));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 std::unique_ptr<protocol::Runtime::RemoteObject> InjectedScript::wrapTable(
@@ -589,7 +591,7 @@ std::unique_ptr<protocol::Runtime::RemoteObject> InjectedScript::wrapTable(
   std::unique_ptr<RemoteObject> remoteObject;
   Response response =
       wrapObject(table, "console", WrapMode::kNoPreview, &remoteObject);
-  if (!remoteObject || !response.isSuccess()) return nullptr;
+  if (!remoteObject || !response.IsSuccess()) return nullptr;
 
   auto mirror = ValueMirror::create(context, table);
   std::unique_ptr<ObjectPreview> preview;
@@ -658,7 +660,8 @@ void InjectedScript::addPromiseCallback(
 
 void InjectedScript::discardEvaluateCallbacks() {
   for (auto& callback : m_evaluateCallbacks) {
-    callback->sendFailure(Response::Error("Execution context was destroyed."));
+    callback->sendFailure(
+        Response::ServerError("Execution context was destroyed."));
     delete callback;
   }
   m_evaluateCallbacks.clear();
@@ -677,9 +680,9 @@ Response InjectedScript::findObject(const RemoteObjectId& objectId,
                                     v8::Local<v8::Value>* outObject) const {
   auto it = m_idToWrappedObject.find(objectId.id());
   if (it == m_idToWrappedObject.end())
-    return Response::Error("Could not find object with given id");
+    return Response::ServerError("Could not find object with given id");
   *outObject = it->second.Get(m_context->isolate());
-  return Response::OK();
+  return Response::Success();
 }
 
 String16 InjectedScript::objectGroupName(const RemoteObjectId& objectId) const {
@@ -719,9 +722,9 @@ Response InjectedScript::resolveCallArgument(
     std::unique_ptr<RemoteObjectId> remoteObjectId;
     Response response =
         RemoteObjectId::parse(callArgument->getObjectId(""), &remoteObjectId);
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
     if (remoteObjectId->contextId() != m_context->contextId())
-      return Response::Error(
+      return Response::ServerError(
           "Argument should belong to the same JavaScript world as target "
           "object");
     return findObject(*remoteObjectId, result);
@@ -729,10 +732,10 @@ Response InjectedScript::resolveCallArgument(
   if (callArgument->hasValue() || callArgument->hasUnserializableValue()) {
     String16 value;
     if (callArgument->hasValue()) {
-      std::vector<uint8_t> cbor =
-          std::move(*callArgument->getValue(nullptr)).TakeSerialized();
       std::vector<uint8_t> json;
-      v8_crdtp::json::ConvertCBORToJSON(v8_crdtp::SpanFrom(cbor), &json);
+      v8_crdtp::json::ConvertCBORToJSON(
+          v8_crdtp::SpanFrom(callArgument->getValue(nullptr)->Serialize()),
+          &json);
       value =
           "(" +
           String16(reinterpret_cast<const char*>(json.data()), json.size()) +
@@ -749,28 +752,29 @@ Response InjectedScript::resolveCallArgument(
              ->compileAndRunInternalScript(
                  m_context->context(), toV8String(m_context->isolate(), value))
              .ToLocal(result)) {
-      return Response::Error("Couldn't parse value object in call argument");
+      return Response::ServerError(
+          "Couldn't parse value object in call argument");
     }
-    return Response::OK();
+    return Response::Success();
   }
   *result = v8::Undefined(m_context->isolate());
-  return Response::OK();
+  return Response::Success();
 }
 
 Response InjectedScript::addExceptionToDetails(
     v8::Local<v8::Value> exception,
     protocol::Runtime::ExceptionDetails* exceptionDetails,
     const String16& objectGroup) {
-  if (exception.IsEmpty()) return Response::OK();
+  if (exception.IsEmpty()) return Response::Success();
   std::unique_ptr<protocol::Runtime::RemoteObject> wrapped;
   Response response =
       wrapObject(exception, objectGroup,
                  exception->IsNativeError() ? WrapMode::kNoPreview
                                             : WrapMode::kWithPreview,
                  &wrapped);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   exceptionDetails->setException(std::move(wrapped));
-  return Response::OK();
+  return Response::Success();
 }
 
 Response InjectedScript::createExceptionDetails(
@@ -817,9 +821,9 @@ Response InjectedScript::createExceptionDetails(
   }
   Response response =
       addExceptionToDetails(exception, exceptionDetails.get(), objectGroup);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   *result = std::move(exceptionDetails);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response InjectedScript::wrapEvaluateResult(
@@ -832,14 +836,14 @@ Response InjectedScript::wrapEvaluateResult(
     if (!maybeResultValue.ToLocal(&resultValue))
       return Response::InternalError();
     Response response = wrapObject(resultValue, objectGroup, wrapMode, result);
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
     if (objectGroup == "console") {
       m_lastEvaluationResult.Reset(m_context->isolate(), resultValue);
       m_lastEvaluationResult.AnnotateStrongRetainer(kGlobalHandleLabel);
     }
   } else {
     if (tryCatch.HasTerminated() || !tryCatch.CanContinue()) {
-      return Response::Error("Execution was terminated");
+      return Response::ServerError("Execution was terminated");
     }
     v8::Local<v8::Value> exception = tryCatch.Exception();
     Response response =
@@ -847,13 +851,13 @@ Response InjectedScript::wrapEvaluateResult(
                    exception->IsNativeError() ? WrapMode::kNoPreview
                                               : WrapMode::kWithPreview,
                    result);
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
     // We send exception in result for compatibility reasons, even though it's
     // accessible through exceptionDetails.exception.
     response = createExceptionDetails(tryCatch, objectGroup, exceptionDetails);
-    if (!response.isSuccess()) return response;
+    if (!response.IsSuccess()) return response;
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 v8::Local<v8::Object> InjectedScript::commandLineAPI() {
@@ -885,11 +889,11 @@ Response InjectedScript::Scope::initialize() {
       m_inspector->sessionById(m_contextGroupId, m_sessionId);
   if (!session) return Response::InternalError();
   Response response = findInjectedScript(session);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   m_context = m_injectedScript->context()->context();
   m_context->Enter();
   if (m_allowEval) m_context->AllowCodeGenerationFromStrings(true);
-  return Response::OK();
+  return Response::Success();
 }
 
 void InjectedScript::Scope::installCommandLineAPI() {
@@ -972,15 +976,15 @@ Response InjectedScript::ObjectScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
   std::unique_ptr<RemoteObjectId> remoteId;
   Response response = RemoteObjectId::parse(m_remoteObjectId, &remoteId);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   InjectedScript* injectedScript = nullptr;
   response = session->findInjectedScript(remoteId.get(), injectedScript);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   m_objectGroupName = injectedScript->objectGroupName(*remoteId);
   response = injectedScript->findObject(*remoteId, &m_object);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   m_injectedScript = injectedScript;
-  return Response::OK();
+  return Response::Success();
 }
 
 InjectedScript::CallFrameScope::CallFrameScope(V8InspectorSessionImpl* session,
@@ -993,7 +997,7 @@ Response InjectedScript::CallFrameScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
   std::unique_ptr<RemoteCallFrameId> remoteId;
   Response response = RemoteCallFrameId::parse(m_remoteCallFrameId, &remoteId);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   m_frameOrdinal = static_cast<size_t>(remoteId->frameOrdinal());
   return session->findInjectedScript(remoteId.get(), m_injectedScript);
 }
@@ -1018,9 +1022,9 @@ String16 InjectedScript::bindObject(v8::Local<v8::Value> value,
 Response InjectedScript::bindRemoteObjectIfNeeded(
     int sessionId, v8::Local<v8::Context> context, v8::Local<v8::Value> value,
     const String16& groupName, protocol::Runtime::RemoteObject* remoteObject) {
-  if (!remoteObject) return Response::OK();
-  if (remoteObject->hasValue()) return Response::OK();
-  if (remoteObject->hasUnserializableValue()) return Response::OK();
+  if (!remoteObject) return Response::Success();
+  if (remoteObject->hasValue()) return Response::Success();
+  if (remoteObject->hasUnserializableValue()) return Response::Success();
   if (remoteObject->getType() != RemoteObject::TypeEnum::Undefined) {
     v8::Isolate* isolate = context->GetIsolate();
     V8InspectorImpl* inspector =
@@ -1031,11 +1035,11 @@ Response InjectedScript::bindRemoteObjectIfNeeded(
         inspectedContext ? inspectedContext->getInjectedScript(sessionId)
                          : nullptr;
     if (!injectedScript) {
-      return Response::Error("Cannot find context with specified id");
+      return Response::ServerError("Cannot find context with specified id");
     }
     remoteObject->setObjectId(injectedScript->bindObject(value, groupName));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 void InjectedScript::unbindObject(int id) {
diff --git a/deps/v8/src/inspector/remote-object-id.cc b/deps/v8/src/inspector/remote-object-id.cc
index 2f5f051816..e3c67bb6c9 100644
--- a/deps/v8/src/inspector/remote-object-id.cc
+++ b/deps/v8/src/inspector/remote-object-id.cc
@@ -4,6 +4,7 @@
 
 #include "src/inspector/remote-object-id.h"
 
+#include "../../third_party/inspector_protocol/crdtp/json.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/string-util.h"
 
@@ -13,8 +14,12 @@ RemoteObjectIdBase::RemoteObjectIdBase() : m_injectedScriptId(0) {}
 
 std::unique_ptr<protocol::DictionaryValue>
 RemoteObjectIdBase::parseInjectedScriptId(const String16& objectId) {
+  std::vector<uint8_t> cbor;
+  v8_crdtp::json::ConvertJSONToCBOR(
+      v8_crdtp::span<uint16_t>(objectId.characters16(), objectId.length()),
+      &cbor);
   std::unique_ptr<protocol::Value> parsedValue =
-      protocol::StringUtil::parseJSON(objectId);
+      protocol::Value::parseBinary(cbor.data(), cbor.size());
   if (!parsedValue || parsedValue->type() != protocol::Value::TypeObject)
     return nullptr;
 
@@ -33,12 +38,12 @@ Response RemoteObjectId::parse(const String16& objectId,
   std::unique_ptr<RemoteObjectId> remoteObjectId(new RemoteObjectId());
   std::unique_ptr<protocol::DictionaryValue> parsedObjectId =
       remoteObjectId->parseInjectedScriptId(objectId);
-  if (!parsedObjectId) return Response::Error("Invalid remote object id");
+  if (!parsedObjectId) return Response::ServerError("Invalid remote object id");
 
   bool success = parsedObjectId->getInteger("id", &remoteObjectId->m_id);
-  if (!success) return Response::Error("Invalid remote object id");
+  if (!success) return Response::ServerError("Invalid remote object id");
   *result = std::move(remoteObjectId);
-  return Response::OK();
+  return Response::Success();
 }
 
 RemoteCallFrameId::RemoteCallFrameId()
@@ -49,13 +54,13 @@ Response RemoteCallFrameId::parse(const String16& objectId,
   std::unique_ptr<RemoteCallFrameId> remoteCallFrameId(new RemoteCallFrameId());
   std::unique_ptr<protocol::DictionaryValue> parsedObjectId =
       remoteCallFrameId->parseInjectedScriptId(objectId);
-  if (!parsedObjectId) return Response::Error("Invalid call frame id");
+  if (!parsedObjectId) return Response::ServerError("Invalid call frame id");
 
   bool success =
       parsedObjectId->getInteger("ordinal", &remoteCallFrameId->m_frameOrdinal);
-  if (!success) return Response::Error("Invalid call frame id");
+  if (!success) return Response::ServerError("Invalid call frame id");
   *result = std::move(remoteCallFrameId);
-  return Response::OK();
+  return Response::Success();
 }
 
 String16 RemoteCallFrameId::serialize(int injectedScriptId, int frameOrdinal) {
diff --git a/deps/v8/src/inspector/string-16.cc b/deps/v8/src/inspector/string-16.cc
index 15344ee2b8..43b581a1b5 100644
--- a/deps/v8/src/inspector/string-16.cc
+++ b/deps/v8/src/inspector/string-16.cc
@@ -208,21 +208,8 @@ String16 String16::fromUTF8(const char* stringStart, size_t length) {
   return String16(UTF8ToUTF16(stringStart, length));
 }
 
-String16 String16::fromUTF16LE(const UChar* stringStart, size_t length) {
-#ifdef V8_TARGET_BIG_ENDIAN
-  // Need to flip the byte order on big endian machines.
-  String16Builder builder;
-  builder.reserveCapacity(length);
-  for (size_t i = 0; i < length; i++) {
-    const UChar utf16be_char =
-        stringStart[i] << 8 | (stringStart[i] >> 8 & 0x00FF);
-    builder.append(utf16be_char);
-  }
-  return builder.toString();
-#else
-  // No need to do anything on little endian machines.
+String16 String16::fromUTF16(const UChar* stringStart, size_t length) {
   return String16(stringStart, length);
-#endif  // V8_TARGET_BIG_ENDIAN
 }
 
 std::string String16::utf8() const {
diff --git a/deps/v8/src/inspector/string-16.h b/deps/v8/src/inspector/string-16.h
index 16d2b15527..b4cbd016a6 100644
--- a/deps/v8/src/inspector/string-16.h
+++ b/deps/v8/src/inspector/string-16.h
@@ -70,11 +70,7 @@ class String16 {
   // Convenience methods.
   V8_EXPORT std::string utf8() const;
   V8_EXPORT static String16 fromUTF8(const char* stringStart, size_t length);
-
-  // Instantiates a String16 in native endianness from UTF16 LE.
-  // On Big endian architectures, byte order needs to be flipped.
-  V8_EXPORT static String16 fromUTF16LE(const UChar* stringStart,
-                                        size_t length);
+  V8_EXPORT static String16 fromUTF16(const UChar* stringStart, size_t length);
 
   std::size_t hash() const {
     if (!hash_code) {
diff --git a/deps/v8/src/inspector/string-util.cc b/deps/v8/src/inspector/string-util.cc
index e37b59b1c8..3f779e86e1 100644
--- a/deps/v8/src/inspector/string-util.cc
+++ b/deps/v8/src/inspector/string-util.cc
@@ -95,75 +95,43 @@ bool stringViewStartsWith(const StringView& string, const char* prefix) {
   return true;
 }
 
-namespace protocol {
-
-// static
-double StringUtil::toDouble(const char* s, size_t len, bool* isOk) {
-  int flags = v8::internal::ALLOW_HEX | v8::internal::ALLOW_OCTAL |
-              v8::internal::ALLOW_BINARY;
-  double result = v8::internal::StringToDouble(s, flags);
-  *isOk = !std::isnan(result);
-  return result;
-}
-
-std::unique_ptr<protocol::Value> StringUtil::parseJSON(
-    const StringView& string) {
-  if (!string.length()) return nullptr;
-  if (string.is8Bit()) {
-    return parseJSONCharacters(string.characters8(),
-                               static_cast<int>(string.length()));
-  }
-  return parseJSONCharacters(string.characters16(),
-                             static_cast<int>(string.length()));
-}
-
-std::unique_ptr<protocol::Value> StringUtil::parseJSON(const String16& string) {
-  if (!string.length()) return nullptr;
-  return parseJSONCharacters(string.characters16(),
-                             static_cast<int>(string.length()));
-}
-}  // namespace protocol
-
 namespace {
 // An empty string buffer doesn't own any string data; its ::string() returns a
 // default-constructed StringView instance.
 class EmptyStringBuffer : public StringBuffer {
  public:
-  const StringView& string() override { return string_; }
-
- private:
-  StringView string_;
+  StringView string() const override { return StringView(); }
 };
 
 // Contains LATIN1 text data or CBOR encoded binary data in a vector.
 class StringBuffer8 : public StringBuffer {
  public:
-  explicit StringBuffer8(std::vector<uint8_t> data)
-      : data_(std::move(data)), string_(data_.data(), data_.size()) {}
+  explicit StringBuffer8(std::vector<uint8_t> data) : data_(std::move(data)) {}
 
-  const StringView& string() override { return string_; }
+  StringView string() const override {
+    return StringView(data_.data(), data_.size());
+  }
 
  private:
   std::vector<uint8_t> data_;
-  StringView string_;
 };
 
 // Contains a 16 bit string (String16).
 class StringBuffer16 : public StringBuffer {
  public:
-  explicit StringBuffer16(String16 data)
-      : data_(std::move(data)), string_(data_.characters16(), data_.length()) {}
+  explicit StringBuffer16(String16 data) : data_(std::move(data)) {}
 
-  const StringView& string() override { return string_; }
+  StringView string() const override {
+    return StringView(data_.characters16(), data_.length());
+  }
 
  private:
   String16 data_;
-  StringView string_;
 };
 }  // namespace
 
 // static
-std::unique_ptr<StringBuffer> StringBuffer::create(const StringView& string) {
+std::unique_ptr<StringBuffer> StringBuffer::create(StringView string) {
   if (string.length() == 0) return std::make_unique<EmptyStringBuffer>();
   if (string.is8Bit()) {
     return std::make_unique<StringBuffer8>(std::vector<uint8_t>(
@@ -190,3 +158,10 @@ String16 stackTraceIdToString(uintptr_t id) {
 }
 
 }  // namespace v8_inspector
+
+namespace v8_crdtp {
+void SerializerTraits<v8_inspector::protocol::Binary>::Serialize(
+    const v8_inspector::protocol::Binary& binary, std::vector<uint8_t>* out) {
+  cbor::EncodeBinary(span<uint8_t>(binary.data(), binary.size()), out);
+}
+}  // namespace v8_crdtp
diff --git a/deps/v8/src/inspector/string-util.h b/deps/v8/src/inspector/string-util.h
index 15925b663c..50d3614e54 100644
--- a/deps/v8/src/inspector/string-util.h
+++ b/deps/v8/src/inspector/string-util.h
@@ -21,59 +21,15 @@ namespace protocol {
 class Value;
 
 using String = v8_inspector::String16;
-using StringBuilder = v8_inspector::String16Builder;
 
 class StringUtil {
  public:
-  static String substring(const String& s, size_t pos, size_t len) {
-    return s.substring(pos, len);
-  }
-  static String fromInteger(int number) { return String::fromInteger(number); }
-  static String fromInteger(size_t number) {
-    return String::fromInteger(number);
-  }
-  static String fromDouble(double number) { return String::fromDouble(number); }
-  static double toDouble(const char* s, size_t len, bool* isOk);
-  static size_t find(const String& s, const char* needle) {
-    return s.find(needle);
-  }
-  static size_t find(const String& s, const String& needle) {
-    return s.find(needle);
-  }
-  static const size_t kNotFound = String::kNotFound;
-  static void builderAppend(
-      StringBuilder& builder,  // NOLINT(runtime/references)
-      const String& s) {
-    builder.append(s);
-  }
-  static void builderAppend(
-      StringBuilder& builder,  // NOLINT(runtime/references)
-      UChar c) {
-    builder.append(c);
-  }
-  static void builderAppend(
-      StringBuilder& builder,  // NOLINT(runtime/references)
-      const char* s, size_t len) {
-    builder.append(s, len);
-  }
-  static void builderReserve(
-      StringBuilder& builder,  // NOLINT(runtime/references)
-      size_t capacity) {
-    builder.reserveCapacity(capacity);
-  }
-  static String builderToString(
-      StringBuilder& builder) {  // NOLINT(runtime/references)
-    return builder.toString();
-  }
-  static std::unique_ptr<protocol::Value> parseJSON(const String16& json);
-  static std::unique_ptr<protocol::Value> parseJSON(const StringView& json);
-
   static String fromUTF8(const uint8_t* data, size_t length) {
     return String16::fromUTF8(reinterpret_cast<const char*>(data), length);
   }
 
   static String fromUTF16LE(const uint16_t* data, size_t length) {
-    return String16::fromUTF16LE(data, length);
+    return String16::fromUTF16(data, length);
   }
 
   static const uint8_t* CharactersLatin1(const String& s) { return nullptr; }
@@ -133,4 +89,13 @@ String16 stackTraceIdToString(uintptr_t id);
 
 }  //  namespace v8_inspector
 
+// See third_party/inspector_protocol/crdtp/serializer_traits.h.
+namespace v8_crdtp {
+template <>
+struct SerializerTraits<v8_inspector::protocol::Binary> {
+  static void Serialize(const v8_inspector::protocol::Binary& binary,
+                        std::vector<uint8_t>* out);
+};
+}  // namespace v8_crdtp
+
 #endif  // V8_INSPECTOR_STRING_UTIL_H_
diff --git a/deps/v8/src/inspector/v8-console-agent-impl.cc b/deps/v8/src/inspector/v8-console-agent-impl.cc
index 66c96110d7..eb00c5cdb5 100644
--- a/deps/v8/src/inspector/v8-console-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-console-agent-impl.cc
@@ -27,23 +27,23 @@ V8ConsoleAgentImpl::V8ConsoleAgentImpl(
 V8ConsoleAgentImpl::~V8ConsoleAgentImpl() = default;
 
 Response V8ConsoleAgentImpl::enable() {
-  if (m_enabled) return Response::OK();
+  if (m_enabled) return Response::Success();
   m_state->setBoolean(ConsoleAgentState::consoleEnabled, true);
   m_enabled = true;
   m_session->inspector()->enableStackCapturingIfNeeded();
   reportAllMessages();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ConsoleAgentImpl::disable() {
-  if (!m_enabled) return Response::OK();
+  if (!m_enabled) return Response::Success();
   m_session->inspector()->disableStackCapturingIfNeeded();
   m_state->setBoolean(ConsoleAgentState::consoleEnabled, false);
   m_enabled = false;
-  return Response::OK();
+  return Response::Success();
 }
 
-Response V8ConsoleAgentImpl::clearMessages() { return Response::OK(); }
+Response V8ConsoleAgentImpl::clearMessages() { return Response::Success(); }
 
 void V8ConsoleAgentImpl::restore() {
   if (!m_state->booleanProperty(ConsoleAgentState::consoleEnabled, false))
diff --git a/deps/v8/src/inspector/v8-console.cc b/deps/v8/src/inspector/v8-console.cc
index f4d0ffa055..ec7709f8c6 100644
--- a/deps/v8/src/inspector/v8-console.cc
+++ b/deps/v8/src/inspector/v8-console.cc
@@ -595,7 +595,7 @@ static void inspectImpl(const v8::FunctionCallbackInfo<v8::Value>& info,
   std::unique_ptr<protocol::Runtime::RemoteObject> wrappedObject;
   protocol::Response response = injectedScript->wrapObject(
       value, "", WrapMode::kNoPreview, &wrappedObject);
-  if (!response.isSuccess()) return;
+  if (!response.IsSuccess()) return;
 
   std::unique_ptr<protocol::DictionaryValue> hints =
       protocol::DictionaryValue::create();
diff --git a/deps/v8/src/inspector/v8-debugger-agent-impl.cc b/deps/v8/src/inspector/v8-debugger-agent-impl.cc
index 0176bef645..2e5c8cd417 100644
--- a/deps/v8/src/inspector/v8-debugger-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-debugger-agent-impl.cc
@@ -6,10 +6,12 @@
 
 #include <algorithm>
 
+#include "../../third_party/inspector_protocol/crdtp/json.h"
 #include "src/base/safe_conversions.h"
 #include "src/debug/debug-interface.h"
 #include "src/inspector/injected-script.h"
 #include "src/inspector/inspected-context.h"
+#include "src/inspector/protocol/Debugger.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/remote-object-id.h"
 #include "src/inspector/search-util.h"
@@ -241,6 +243,8 @@ String16 scopeType(v8::debug::ScopeIterator::ScopeType type) {
       return Scope::TypeEnum::Eval;
     case v8::debug::ScopeIterator::ScopeTypeModule:
       return Scope::TypeEnum::Module;
+    case v8::debug::ScopeIterator::ScopeTypeWasmExpressionStack:
+      return Scope::TypeEnum::WasmExpressionStack;
   }
   UNREACHABLE();
   return String16();
@@ -250,8 +254,8 @@ Response buildScopes(v8::Isolate* isolate, v8::debug::ScopeIterator* iterator,
                      InjectedScript* injectedScript,
                      std::unique_ptr<Array<Scope>>* scopes) {
   *scopes = std::make_unique<Array<Scope>>();
-  if (!injectedScript) return Response::OK();
-  if (iterator->Done()) return Response::OK();
+  if (!injectedScript) return Response::Success();
+  if (iterator->Done()) return Response::Success();
 
   String16 scriptId = String16::fromInteger(iterator->GetScriptId());
 
@@ -260,7 +264,7 @@ Response buildScopes(v8::Isolate* isolate, v8::debug::ScopeIterator* iterator,
     Response result =
         injectedScript->wrapObject(iterator->GetObject(), kBacktraceObjectGroup,
                                    WrapMode::kNoPreview, &object);
-    if (!result.isSuccess()) return result;
+    if (!result.IsSuccess()) return result;
 
     auto scope = Scope::create()
                      .setType(scopeType(iterator->GetType()))
@@ -288,7 +292,7 @@ Response buildScopes(v8::Isolate* isolate, v8::debug::ScopeIterator* iterator,
     }
     (*scopes)->emplace_back(std::move(scope));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 protocol::DictionaryValue* getOrCreateObject(protocol::DictionaryValue* object,
@@ -342,17 +346,17 @@ Response V8DebuggerAgentImpl::enable(Maybe<double> maxScriptsCacheSize,
       maxScriptsCacheSize.fromMaybe(std::numeric_limits<double>::max()));
   *outDebuggerId =
       m_debugger->debuggerIdFor(m_session->contextGroupId()).toString();
-  if (enabled()) return Response::OK();
+  if (enabled()) return Response::Success();
 
   if (!m_inspector->client()->canExecuteScripts(m_session->contextGroupId()))
-    return Response::Error("Script execution is prohibited");
+    return Response::ServerError("Script execution is prohibited");
 
   enableImpl();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::disable() {
-  if (!enabled()) return Response::OK();
+  if (!enabled()) return Response::Success();
 
   m_state->remove(DebuggerAgentState::breakpointsByRegex);
   m_state->remove(DebuggerAgentState::breakpointsByUrl);
@@ -387,7 +391,7 @@ Response V8DebuggerAgentImpl::disable() {
   m_enabled = false;
   m_state->setBoolean(DebuggerAgentState::debuggerEnabled, false);
   m_debugger->disable();
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8DebuggerAgentImpl::restore() {
@@ -419,21 +423,21 @@ void V8DebuggerAgentImpl::restore() {
 }
 
 Response V8DebuggerAgentImpl::setBreakpointsActive(bool active) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
-  if (m_breakpointsActive == active) return Response::OK();
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
+  if (m_breakpointsActive == active) return Response::Success();
   m_breakpointsActive = active;
   m_debugger->setBreakpointsActive(active);
   if (!active && !m_breakReason.empty()) {
     clearBreakDetails();
     m_debugger->setPauseOnNextCall(false, m_session->contextGroupId());
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setSkipAllPauses(bool skip) {
   m_state->setBoolean(DebuggerAgentState::skipAllPauses, skip);
   m_skipAllPauses = skip;
-  return Response::OK();
+  return Response::Success();
 }
 
 static bool matches(V8InspectorImpl* inspector, const V8DebuggerScript& script,
@@ -467,13 +471,14 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
                   (optionalURLRegex.isJust() ? 1 : 0) +
                   (optionalScriptHash.isJust() ? 1 : 0);
   if (specified != 1) {
-    return Response::Error(
+    return Response::ServerError(
         "Either url or urlRegex or scriptHash must be specified.");
   }
   int columnNumber = 0;
   if (optionalColumnNumber.isJust()) {
     columnNumber = optionalColumnNumber.fromJust();
-    if (columnNumber < 0) return Response::Error("Incorrect column number");
+    if (columnNumber < 0)
+      return Response::ServerError("Incorrect column number");
   }
 
   BreakpointType type = BreakpointType::kByUrl;
@@ -513,7 +518,8 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
       UNREACHABLE();
   }
   if (breakpoints->get(breakpointId)) {
-    return Response::Error("Breakpoint at specified location already exists.");
+    return Response::ServerError(
+        "Breakpoint at specified location already exists.");
   }
 
   String16 hint;
@@ -537,7 +543,7 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
     breakpointHints->setString(breakpointId, hint);
   }
   *outBreakpointId = breakpointId;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setBreakpoint(
@@ -549,15 +555,17 @@ Response V8DebuggerAgentImpl::setBreakpoint(
       location->getLineNumber(), location->getColumnNumber(0));
   if (m_breakpointIdToDebuggerBreakpointIds.find(breakpointId) !=
       m_breakpointIdToDebuggerBreakpointIds.end()) {
-    return Response::Error("Breakpoint at specified location already exists.");
+    return Response::ServerError(
+        "Breakpoint at specified location already exists.");
   }
   *actualLocation = setBreakpointImpl(breakpointId, location->getScriptId(),
                                       optionalCondition.fromMaybe(String16()),
                                       location->getLineNumber(),
                                       location->getColumnNumber(0));
-  if (!*actualLocation) return Response::Error("Could not resolve breakpoint");
+  if (!*actualLocation)
+    return Response::ServerError("Could not resolve breakpoint");
   *outBreakpointId = breakpointId;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setBreakpointOnFunctionCall(
@@ -565,9 +573,9 @@ Response V8DebuggerAgentImpl::setBreakpointOnFunctionCall(
     String16* outBreakpointId) {
   InjectedScript::ObjectScope scope(m_session, functionObjectId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (!scope.object()->IsFunction()) {
-    return Response::Error("Could not find function with given id");
+    return Response::ServerError("Could not find function with given id");
   }
   v8::Local<v8::Function> function =
       v8::Local<v8::Function>::Cast(scope.object());
@@ -575,35 +583,37 @@ Response V8DebuggerAgentImpl::setBreakpointOnFunctionCall(
       generateBreakpointId(BreakpointType::kBreakpointAtEntry, function);
   if (m_breakpointIdToDebuggerBreakpointIds.find(breakpointId) !=
       m_breakpointIdToDebuggerBreakpointIds.end()) {
-    return Response::Error("Breakpoint at specified location already exists.");
+    return Response::ServerError(
+        "Breakpoint at specified location already exists.");
   }
   v8::Local<v8::String> condition =
       toV8String(m_isolate, optionalCondition.fromMaybe(String16()));
   setBreakpointImpl(breakpointId, function, condition);
   *outBreakpointId = breakpointId;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setInstrumentationBreakpoint(
     const String16& instrumentation, String16* outBreakpointId) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
   String16 breakpointId = generateInstrumentationBreakpointId(instrumentation);
   protocol::DictionaryValue* breakpoints = getOrCreateObject(
       m_state, DebuggerAgentState::instrumentationBreakpoints);
   if (breakpoints->get(breakpointId)) {
-    return Response::Error("Instrumentation breakpoint is already enabled.");
+    return Response::ServerError(
+        "Instrumentation breakpoint is already enabled.");
   }
   breakpoints->setBoolean(breakpointId, true);
   *outBreakpointId = breakpointId;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
   BreakpointType type;
   String16 selector;
   if (!parseBreakpointId(breakpointId, &type, &selector)) {
-    return Response::OK();
+    return Response::Success();
   }
   protocol::DictionaryValue* breakpoints = nullptr;
   switch (type) {
@@ -647,7 +657,7 @@ Response V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
   }
   removeBreakpointImpl(breakpointId, scripts);
 
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8DebuggerAgentImpl::removeBreakpointImpl(
@@ -679,7 +689,7 @@ Response V8DebuggerAgentImpl::getPossibleBreakpoints(
   String16 scriptId = start->getScriptId();
 
   if (start->getLineNumber() < 0 || start->getColumnNumber(0) < 0)
-    return Response::Error(
+    return Response::ServerError(
         "start.lineNumber and start.columnNumber should be >= 0");
 
   v8::debug::Location v8Start(start->getLineNumber(),
@@ -687,23 +697,24 @@ Response V8DebuggerAgentImpl::getPossibleBreakpoints(
   v8::debug::Location v8End;
   if (end.isJust()) {
     if (end.fromJust()->getScriptId() != scriptId)
-      return Response::Error("Locations should contain the same scriptId");
+      return Response::ServerError(
+          "Locations should contain the same scriptId");
     int line = end.fromJust()->getLineNumber();
     int column = end.fromJust()->getColumnNumber(0);
     if (line < 0 || column < 0)
-      return Response::Error(
+      return Response::ServerError(
           "end.lineNumber and end.columnNumber should be >= 0");
     v8End = v8::debug::Location(line, column);
   }
   auto it = m_scripts.find(scriptId);
-  if (it == m_scripts.end()) return Response::Error("Script not found");
+  if (it == m_scripts.end()) return Response::ServerError("Script not found");
   std::vector<v8::debug::BreakLocation> v8Locations;
   {
     v8::HandleScope handleScope(m_isolate);
     int contextId = it->second->executionContextId();
     InspectedContext* inspected = m_inspector->getContext(contextId);
     if (!inspected) {
-      return Response::Error("Cannot retrive script context");
+      return Response::ServerError("Cannot retrive script context");
     }
     v8::Context::Scope contextScope(inspected->context());
     v8::MicrotasksScope microtasks(m_isolate,
@@ -727,23 +738,23 @@ Response V8DebuggerAgentImpl::getPossibleBreakpoints(
     }
     (*locations)->emplace_back(std::move(breakLocation));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::continueToLocation(
     std::unique_ptr<protocol::Debugger::Location> location,
     Maybe<String16> targetCallFrames) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   ScriptsMap::iterator it = m_scripts.find(location->getScriptId());
   if (it == m_scripts.end()) {
-    return Response::Error("Cannot continue to specified location");
+    return Response::ServerError("Cannot continue to specified location");
   }
   V8DebuggerScript* script = it->second.get();
   int contextId = script->executionContextId();
   InspectedContext* inspected = m_inspector->getContext(contextId);
   if (!inspected)
-    return Response::Error("Cannot continue to specified location");
+    return Response::ServerError("Cannot continue to specified location");
   v8::HandleScope handleScope(m_isolate);
   v8::Context::Scope contextScope(inspected->context());
   return m_debugger->continueToLocation(
@@ -757,7 +768,7 @@ Response V8DebuggerAgentImpl::getStackTrace(
     std::unique_ptr<protocol::Runtime::StackTrace>* outStackTrace) {
   bool isOk = false;
   int64_t id = inStackTraceId->getId().toInteger64(&isOk);
-  if (!isOk) return Response::Error("Invalid stack trace id");
+  if (!isOk) return Response::ServerError("Invalid stack trace id");
 
   V8DebuggerId debuggerId;
   if (inStackTraceId->hasDebuggerId()) {
@@ -765,19 +776,20 @@ Response V8DebuggerAgentImpl::getStackTrace(
   } else {
     debuggerId = m_debugger->debuggerIdFor(m_session->contextGroupId());
   }
-  if (!debuggerId.isValid()) return Response::Error("Invalid stack trace id");
+  if (!debuggerId.isValid())
+    return Response::ServerError("Invalid stack trace id");
 
   V8StackTraceId v8StackTraceId(id, debuggerId.pair());
   if (v8StackTraceId.IsInvalid())
-    return Response::Error("Invalid stack trace id");
+    return Response::ServerError("Invalid stack trace id");
   auto stack =
       m_debugger->stackTraceFor(m_session->contextGroupId(), v8StackTraceId);
   if (!stack) {
-    return Response::Error("Stack trace with given id is not found");
+    return Response::ServerError("Stack trace with given id is not found");
   }
   *outStackTrace = stack->buildInspectorObject(
       m_debugger, m_debugger->maxAsyncCallChainDepth());
-  return Response::OK();
+  return Response::Success();
 }
 
 bool V8DebuggerAgentImpl::isFunctionBlackboxed(const String16& scriptId,
@@ -877,13 +889,13 @@ Response V8DebuggerAgentImpl::searchInContent(
   v8::HandleScope handles(m_isolate);
   ScriptsMap::iterator it = m_scripts.find(scriptId);
   if (it == m_scripts.end())
-    return Response::Error("No script for id: " + scriptId);
+    return Response::ServerError("No script for id: " + scriptId.utf8());
 
   *results = std::make_unique<protocol::Array<protocol::Debugger::SearchMatch>>(
       searchInTextByLinesImpl(m_session, it->second->source(0), query,
                               optionalCaseSensitive.fromMaybe(false),
                               optionalIsRegex.fromMaybe(false)));
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setScriptSource(
@@ -893,11 +905,11 @@ Response V8DebuggerAgentImpl::setScriptSource(
     Maybe<protocol::Runtime::StackTrace>* asyncStackTrace,
     Maybe<protocol::Runtime::StackTraceId>* asyncStackTraceId,
     Maybe<protocol::Runtime::ExceptionDetails>* optOutCompileError) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
 
   ScriptsMap::iterator it = m_scripts.find(scriptId);
   if (it == m_scripts.end()) {
-    return Response::Error("No script with given id found");
+    return Response::ServerError("No script with given id found");
   }
   int contextId = it->second->executionContextId();
   InspectedContext* inspected = m_inspector->getContext(contextId);
@@ -920,17 +932,17 @@ Response V8DebuggerAgentImpl::setScriptSource(
             .setColumnNumber(result.column_number != -1 ? result.column_number
                                                         : 0)
             .build();
-    return Response::OK();
+    return Response::Success();
   } else {
     *stackChanged = result.stack_changed;
   }
   std::unique_ptr<Array<CallFrame>> callFrames;
   Response response = currentCallFrames(&callFrames);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   *newCallFrames = std::move(callFrames);
   *asyncStackTrace = currentAsyncStackTrace();
   *asyncStackTraceId = currentExternalStackTrace();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::restartFrame(
@@ -938,52 +950,52 @@ Response V8DebuggerAgentImpl::restartFrame(
     std::unique_ptr<Array<CallFrame>>* newCallFrames,
     Maybe<protocol::Runtime::StackTrace>* asyncStackTrace,
     Maybe<protocol::Runtime::StackTraceId>* asyncStackTraceId) {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   InjectedScript::CallFrameScope scope(m_session, callFrameId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   int frameOrdinal = static_cast<int>(scope.frameOrdinal());
   auto it = v8::debug::StackTraceIterator::Create(m_isolate, frameOrdinal);
   if (it->Done()) {
-    return Response::Error("Could not find call frame with given id");
+    return Response::ServerError("Could not find call frame with given id");
   }
   if (!it->Restart()) {
     return Response::InternalError();
   }
   response = currentCallFrames(newCallFrames);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   *asyncStackTrace = currentAsyncStackTrace();
   *asyncStackTraceId = currentExternalStackTrace();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::getScriptSource(
     const String16& scriptId, String16* scriptSource,
     Maybe<protocol::Binary>* bytecode) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
   ScriptsMap::iterator it = m_scripts.find(scriptId);
   if (it == m_scripts.end())
-    return Response::Error("No script for id: " + scriptId);
+    return Response::ServerError("No script for id: " + scriptId.utf8());
   *scriptSource = it->second->source(0);
   v8::MemorySpan<const uint8_t> span;
   if (it->second->wasmBytecode().To(&span)) {
     *bytecode = protocol::Binary::fromSpan(span.data(), span.size());
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::getWasmBytecode(const String16& scriptId,
                                               protocol::Binary* bytecode) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
   ScriptsMap::iterator it = m_scripts.find(scriptId);
   if (it == m_scripts.end())
-    return Response::Error("No script for id: " + scriptId);
+    return Response::ServerError("No script for id: " + scriptId.utf8());
   v8::MemorySpan<const uint8_t> span;
   if (!it->second->wasmBytecode().To(&span))
-    return Response::Error("Script with id " + scriptId +
-                           " is not WebAssembly");
+    return Response::ServerError("Script with id " + scriptId.utf8() +
+                                 " is not WebAssembly");
   *bytecode = protocol::Binary::fromSpan(span.data(), span.size());
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8DebuggerAgentImpl::pushBreakDetails(
@@ -1021,8 +1033,8 @@ void V8DebuggerAgentImpl::cancelPauseOnNextStatement() {
 }
 
 Response V8DebuggerAgentImpl::pause() {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
-  if (isPaused()) return Response::OK();
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
+  if (isPaused()) return Response::Success();
   if (m_debugger->canBreakProgram()) {
     m_debugger->interruptAndBreak(m_session->contextGroupId());
   } else {
@@ -1031,47 +1043,48 @@ Response V8DebuggerAgentImpl::pause() {
     }
     pushBreakDetails(protocol::Debugger::Paused::ReasonEnum::Other, nullptr);
   }
-  return Response::OK();
+  return Response::Success();
 }
 
-Response V8DebuggerAgentImpl::resume() {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+Response V8DebuggerAgentImpl::resume(Maybe<bool> terminateOnResume) {
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   m_session->releaseObjectGroup(kBacktraceObjectGroup);
-  m_debugger->continueProgram(m_session->contextGroupId());
-  return Response::OK();
+  m_debugger->continueProgram(m_session->contextGroupId(),
+                              terminateOnResume.fromMaybe(false));
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::stepOver() {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   m_session->releaseObjectGroup(kBacktraceObjectGroup);
   m_debugger->stepOverStatement(m_session->contextGroupId());
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::stepInto(Maybe<bool> inBreakOnAsyncCall) {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   m_session->releaseObjectGroup(kBacktraceObjectGroup);
   m_debugger->stepIntoStatement(m_session->contextGroupId(),
                                 inBreakOnAsyncCall.fromMaybe(false));
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::stepOut() {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   m_session->releaseObjectGroup(kBacktraceObjectGroup);
   m_debugger->stepOutOfFunction(m_session->contextGroupId());
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::pauseOnAsyncCall(
     std::unique_ptr<protocol::Runtime::StackTraceId> inParentStackTraceId) {
   // Deprecated, just return OK.
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setPauseOnExceptions(
     const String16& stringPauseState) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
   v8::debug::ExceptionBreakState pauseState;
   if (stringPauseState == "none") {
     pauseState = v8::debug::NoBreakOnException;
@@ -1080,11 +1093,11 @@ Response V8DebuggerAgentImpl::setPauseOnExceptions(
   } else if (stringPauseState == "uncaught") {
     pauseState = v8::debug::BreakOnUncaughtException;
   } else {
-    return Response::Error("Unknown pause on exceptions mode: " +
-                           stringPauseState);
+    return Response::ServerError("Unknown pause on exceptions mode: " +
+                                 stringPauseState.utf8());
   }
   setPauseOnExceptionsImpl(pauseState);
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8DebuggerAgentImpl::setPauseOnExceptionsImpl(int pauseState) {
@@ -1102,17 +1115,17 @@ Response V8DebuggerAgentImpl::evaluateOnCallFrame(
     Maybe<bool> throwOnSideEffect, Maybe<double> timeout,
     std::unique_ptr<RemoteObject>* result,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   InjectedScript::CallFrameScope scope(m_session, callFrameId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (includeCommandLineAPI.fromMaybe(false)) scope.installCommandLineAPI();
   if (silent.fromMaybe(false)) scope.ignoreExceptionsAndMuteConsole();
 
   int frameOrdinal = static_cast<int>(scope.frameOrdinal());
   auto it = v8::debug::StackTraceIterator::Create(m_isolate, frameOrdinal);
   if (it->Done()) {
-    return Response::Error("Could not find call frame with given id");
+    return Response::ServerError("Could not find call frame with given id");
   }
 
   v8::MaybeLocal<v8::Value> maybeResultValue;
@@ -1120,7 +1133,7 @@ Response V8DebuggerAgentImpl::evaluateOnCallFrame(
     V8InspectorImpl::EvaluateScope evaluateScope(scope);
     if (timeout.isJust()) {
       response = evaluateScope.setTimeout(timeout.fromJust() / 1000.0);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
     }
     maybeResultValue = it->Evaluate(toV8String(m_isolate, expression),
                                     throwOnSideEffect.fromMaybe(false));
@@ -1128,7 +1141,7 @@ Response V8DebuggerAgentImpl::evaluateOnCallFrame(
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.
   response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   WrapMode mode = generatePreview.fromMaybe(false) ? WrapMode::kWithPreview
                                                    : WrapMode::kNoPreview;
   if (returnByValue.fromMaybe(false)) mode = WrapMode::kForceValue;
@@ -1141,20 +1154,20 @@ Response V8DebuggerAgentImpl::setVariableValue(
     int scopeNumber, const String16& variableName,
     std::unique_ptr<protocol::Runtime::CallArgument> newValueArgument,
     const String16& callFrameId) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   InjectedScript::CallFrameScope scope(m_session, callFrameId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   v8::Local<v8::Value> newValue;
   response = scope.injectedScript()->resolveCallArgument(newValueArgument.get(),
                                                          &newValue);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
 
   int frameOrdinal = static_cast<int>(scope.frameOrdinal());
   auto it = v8::debug::StackTraceIterator::Create(m_isolate, frameOrdinal);
   if (it->Done()) {
-    return Response::Error("Could not find call frame with given id");
+    return Response::ServerError("Could not find call frame with given id");
   }
   auto scopeIterator = it->GetScopeIterator();
   while (!scopeIterator->Done() && scopeNumber > 0) {
@@ -1162,7 +1175,7 @@ Response V8DebuggerAgentImpl::setVariableValue(
     scopeIterator->Advance();
   }
   if (scopeNumber != 0) {
-    return Response::Error("Could not find scope with given number");
+    return Response::ServerError("Could not find scope with given number");
   }
 
   if (!scopeIterator->SetVariableValue(toV8String(m_isolate, variableName),
@@ -1170,40 +1183,40 @@ Response V8DebuggerAgentImpl::setVariableValue(
       scope.tryCatch().HasCaught()) {
     return Response::InternalError();
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setReturnValue(
     std::unique_ptr<protocol::Runtime::CallArgument> protocolNewValue) {
-  if (!enabled()) return Response::Error(kDebuggerNotEnabled);
-  if (!isPaused()) return Response::Error(kDebuggerNotPaused);
+  if (!enabled()) return Response::ServerError(kDebuggerNotEnabled);
+  if (!isPaused()) return Response::ServerError(kDebuggerNotPaused);
   v8::HandleScope handleScope(m_isolate);
   auto iterator = v8::debug::StackTraceIterator::Create(m_isolate);
   if (iterator->Done()) {
-    return Response::Error("Could not find top call frame");
+    return Response::ServerError("Could not find top call frame");
   }
   if (iterator->GetReturnValue().IsEmpty()) {
-    return Response::Error(
+    return Response::ServerError(
         "Could not update return value at non-return position");
   }
   InjectedScript::ContextScope scope(m_session, iterator->GetContextId());
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   v8::Local<v8::Value> newValue;
   response = scope.injectedScript()->resolveCallArgument(protocolNewValue.get(),
                                                          &newValue);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   v8::debug::SetReturnValue(m_isolate, newValue);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setAsyncCallStackDepth(int depth) {
   if (!enabled() && !m_session->runtimeAgent()->enabled()) {
-    return Response::Error(kDebuggerNotEnabled);
+    return Response::ServerError(kDebuggerNotEnabled);
   }
   m_state->setInteger(DebuggerAgentState::asyncCallStackDepth, depth);
   m_debugger->setAsyncCallStackDepth(this, depth);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setBlackboxPatterns(
@@ -1212,7 +1225,7 @@ Response V8DebuggerAgentImpl::setBlackboxPatterns(
     m_blackboxPattern = nullptr;
     resetBlackboxedStateCache();
     m_state->remove(DebuggerAgentState::blackboxPattern);
-    return Response::OK();
+    return Response::Success();
   }
 
   String16Builder patternBuilder;
@@ -1225,19 +1238,20 @@ Response V8DebuggerAgentImpl::setBlackboxPatterns(
   patternBuilder.append(')');
   String16 pattern = patternBuilder.toString();
   Response response = setBlackboxPattern(pattern);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   resetBlackboxedStateCache();
   m_state->setString(DebuggerAgentState::blackboxPattern, pattern);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::setBlackboxPattern(const String16& pattern) {
   std::unique_ptr<V8Regex> regex(new V8Regex(
       m_inspector, pattern, true /** caseSensitive */, false /** multiline */));
   if (!regex->isValid())
-    return Response::Error("Pattern parser error: " + regex->errorMessage());
+    return Response::ServerError("Pattern parser error: " +
+                                 regex->errorMessage().utf8());
   m_blackboxPattern = std::move(regex);
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8DebuggerAgentImpl::resetBlackboxedStateCache() {
@@ -1252,12 +1266,12 @@ Response V8DebuggerAgentImpl::setBlackboxedRanges(
         inPositions) {
   auto it = m_scripts.find(scriptId);
   if (it == m_scripts.end())
-    return Response::Error("No script with passed id.");
+    return Response::ServerError("No script with passed id.");
 
   if (inPositions->empty()) {
     m_blackboxedPositions.erase(scriptId);
     it->second->resetBlackboxedStateCache();
-    return Response::OK();
+    return Response::Success();
   }
 
   std::vector<std::pair<int, int>> positions;
@@ -1265,9 +1279,10 @@ Response V8DebuggerAgentImpl::setBlackboxedRanges(
   for (const std::unique_ptr<protocol::Debugger::ScriptPosition>& position :
        *inPositions) {
     if (position->getLineNumber() < 0)
-      return Response::Error("Position missing 'line' or 'line' < 0.");
+      return Response::ServerError("Position missing 'line' or 'line' < 0.");
     if (position->getColumnNumber() < 0)
-      return Response::Error("Position missing 'column' or 'column' < 0.");
+      return Response::ServerError(
+          "Position missing 'column' or 'column' < 0.");
     positions.push_back(
         std::make_pair(position->getLineNumber(), position->getColumnNumber()));
   }
@@ -1277,20 +1292,20 @@ Response V8DebuggerAgentImpl::setBlackboxedRanges(
     if (positions[i - 1].first == positions[i].first &&
         positions[i - 1].second < positions[i].second)
       continue;
-    return Response::Error(
+    return Response::ServerError(
         "Input positions array is not sorted or contains duplicate values.");
   }
 
   m_blackboxedPositions[scriptId] = positions;
   it->second->resetBlackboxedStateCache();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8DebuggerAgentImpl::currentCallFrames(
     std::unique_ptr<Array<CallFrame>>* result) {
   if (!isPaused()) {
     *result = std::make_unique<Array<CallFrame>>();
-    return Response::OK();
+    return Response::Success();
   }
   v8::HandleScope handles(m_isolate);
   *result = std::make_unique<Array<CallFrame>>();
@@ -1309,7 +1324,7 @@ Response V8DebuggerAgentImpl::currentCallFrames(
     auto scopeIterator = iterator->GetScopeIterator();
     Response res =
         buildScopes(m_isolate, scopeIterator.get(), injectedScript, &scopes);
-    if (!res.isSuccess()) return res;
+    if (!res.IsSuccess()) return res;
 
     std::unique_ptr<RemoteObject> protocolReceiver;
     if (injectedScript) {
@@ -1318,7 +1333,7 @@ Response V8DebuggerAgentImpl::currentCallFrames(
         res =
             injectedScript->wrapObject(receiver, kBacktraceObjectGroup,
                                        WrapMode::kNoPreview, &protocolReceiver);
-        if (!res.isSuccess()) return res;
+        if (!res.IsSuccess()) return res;
       }
     }
     if (!protocolReceiver) {
@@ -1368,12 +1383,12 @@ Response V8DebuggerAgentImpl::currentCallFrames(
       std::unique_ptr<RemoteObject> value;
       res = injectedScript->wrapObject(returnValue, kBacktraceObjectGroup,
                                        WrapMode::kNoPreview, &value);
-      if (!res.isSuccess()) return res;
+      if (!res.IsSuccess()) return res;
       frame->setReturnValue(std::move(value));
     }
     (*result)->emplace_back(std::move(frame));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 std::unique_ptr<protocol::Runtime::StackTrace>
@@ -1399,6 +1414,15 @@ bool V8DebuggerAgentImpl::isPaused() const {
   return m_debugger->isPausedInContextGroup(m_session->contextGroupId());
 }
 
+static String16 getScriptLanguage(const V8DebuggerScript& script) {
+  switch (script.getLanguage()) {
+    case V8DebuggerScript::Language::WebAssembly:
+      return protocol::Debugger::ScriptLanguageEnum::WebAssembly;
+    case V8DebuggerScript::Language::JavaScript:
+      return protocol::Debugger::ScriptLanguageEnum::JavaScript;
+  }
+}
+
 void V8DebuggerAgentImpl::didParseSource(
     std::unique_ptr<V8DebuggerScript> script, bool success) {
   v8::HandleScope handles(m_isolate);
@@ -1417,14 +1441,23 @@ void V8DebuggerAgentImpl::didParseSource(
   if (inspected) {
     // Script reused between different groups/sessions can have a stale
     // execution context id.
+    const String16& aux = inspected->auxData();
+    std::vector<uint8_t> cbor;
+    v8_crdtp::json::ConvertJSONToCBOR(
+        v8_crdtp::span<uint16_t>(aux.characters16(), aux.length()), &cbor);
     executionContextAuxData = protocol::DictionaryValue::cast(
-        protocol::StringUtil::parseJSON(inspected->auxData()));
+        protocol::Value::parseBinary(cbor.data(), cbor.size()));
   }
   bool isLiveEdit = script->isLiveEdit();
   bool hasSourceURLComment = script->hasSourceURLComment();
   bool isModule = script->isModule();
   String16 scriptId = script->scriptId();
   String16 scriptURL = script->sourceURL();
+  String16 scriptLanguage = getScriptLanguage(*script);
+  Maybe<int> codeOffset =
+      script->getLanguage() == V8DebuggerScript::Language::JavaScript
+          ? Maybe<int>()
+          : script->codeOffset();
 
   m_scripts[scriptId] = std::move(script);
   // Release the strong reference to get notified when debugger is the only
@@ -1460,25 +1493,28 @@ void V8DebuggerAgentImpl::didParseSource(
         scriptRef->endLine(), scriptRef->endColumn(), contextId,
         scriptRef->hash(), std::move(executionContextAuxDataParam),
         std::move(sourceMapURLParam), hasSourceURLParam, isModuleParam,
-        scriptRef->length(), std::move(stackTrace));
+        scriptRef->length(), std::move(stackTrace), std::move(codeOffset),
+        std::move(scriptLanguage));
     return;
   }
 
-  // TODO(herhut, dgozman): Report correct length for WASM if needed for
+  // TODO(herhut, dgozman): Report correct length for Wasm if needed for
   // coverage. Or do not send the length at all and change coverage instead.
   if (scriptRef->isSourceLoadedLazily()) {
     m_frontend.scriptParsed(
         scriptId, scriptURL, 0, 0, 0, 0, contextId, scriptRef->hash(),
         std::move(executionContextAuxDataParam), isLiveEditParam,
         std::move(sourceMapURLParam), hasSourceURLParam, isModuleParam, 0,
-        std::move(stackTrace));
+        std::move(stackTrace), std::move(codeOffset),
+        std::move(scriptLanguage));
   } else {
     m_frontend.scriptParsed(
         scriptId, scriptURL, scriptRef->startLine(), scriptRef->startColumn(),
         scriptRef->endLine(), scriptRef->endColumn(), contextId,
         scriptRef->hash(), std::move(executionContextAuxDataParam),
         isLiveEditParam, std::move(sourceMapURLParam), hasSourceURLParam,
-        isModuleParam, scriptRef->length(), std::move(stackTrace));
+        isModuleParam, scriptRef->length(), std::move(stackTrace),
+        std::move(codeOffset), std::move(scriptLanguage));
   }
 
   std::vector<protocol::DictionaryValue*> potentialBreakpoints;
@@ -1654,7 +1690,7 @@ void V8DebuggerAgentImpl::didPause(
 
   std::unique_ptr<Array<CallFrame>> protocolCallFrames;
   Response response = currentCallFrames(&protocolCallFrames);
-  if (!response.isSuccess())
+  if (!response.IsSuccess())
     protocolCallFrames = std::make_unique<Array<CallFrame>>();
 
   m_frontend.paused(std::move(protocolCallFrames), breakReason,
@@ -1665,6 +1701,7 @@ void V8DebuggerAgentImpl::didPause(
 void V8DebuggerAgentImpl::didContinue() {
   clearBreakDetails();
   m_frontend.resumed();
+  m_frontend.flush();
 }
 
 void V8DebuggerAgentImpl::breakProgram(
diff --git a/deps/v8/src/inspector/v8-debugger-agent-impl.h b/deps/v8/src/inspector/v8-debugger-agent-impl.h
index 540d655bc2..df719a4fa3 100644
--- a/deps/v8/src/inspector/v8-debugger-agent-impl.h
+++ b/deps/v8/src/inspector/v8-debugger-agent-impl.h
@@ -98,7 +98,7 @@ class V8DebuggerAgentImpl : public protocol::Debugger::Backend {
   Response getWasmBytecode(const String16& scriptId,
                            protocol::Binary* bytecode) override;
   Response pause() override;
-  Response resume() override;
+  Response resume(Maybe<bool> terminateOnResume) override;
   Response stepOver() override;
   Response stepInto(Maybe<bool> inBreakOnAsyncCall) override;
   Response stepOut() override;
diff --git a/deps/v8/src/inspector/v8-debugger-script.cc b/deps/v8/src/inspector/v8-debugger-script.cc
index f4b3f487c1..551beb242b 100644
--- a/deps/v8/src/inspector/v8-debugger-script.cc
+++ b/deps/v8/src/inspector/v8-debugger-script.cc
@@ -6,6 +6,7 @@
 
 #include "src/base/memory.h"
 #include "src/inspector/inspected-context.h"
+#include "src/inspector/protocol/Debugger.h"
 #include "src/inspector/string-util.h"
 #include "src/inspector/v8-debugger-agent-impl.h"
 #include "src/inspector/v8-inspector-impl.h"
@@ -120,10 +121,16 @@ class ActualScript : public V8DebuggerScript {
     if (!script->IsWasm()) return v8::Nothing<v8::MemorySpan<const uint8_t>>();
     return v8::Just(v8::debug::WasmScript::Cast(*script)->Bytecode());
   }
+  Language getLanguage() const override { return m_language; }
   int startLine() const override { return m_startLine; }
   int startColumn() const override { return m_startColumn; }
   int endLine() const override { return m_endLine; }
   int endColumn() const override { return m_endColumn; }
+  int codeOffset() const override {
+    auto script = this->script();
+    if (!script->IsWasm()) return 0;
+    return v8::debug::WasmScript::Cast(*script)->CodeOffset();
+  }
   bool isSourceLoadedLazily() const override { return false; }
   int length() const override {
     v8::HandleScope scope(m_isolate);
@@ -274,6 +281,11 @@ class ActualScript : public V8DebuggerScript {
     }
 
     USE(script->ContextId().To(&m_executionContextId));
+    if (script->IsWasm()) {
+      m_language = V8DebuggerScript::Language::WebAssembly;
+    } else {
+      m_language = V8DebuggerScript::Language::JavaScript;
+    }
 
     m_isModule = script->IsModule();
 
@@ -297,6 +309,7 @@ class ActualScript : public V8DebuggerScript {
 
   V8DebuggerAgentImpl* m_agent;
   String16 m_sourceMappingURL;
+  Language m_language;
   bool m_isLiveEdit = false;
   bool m_isModule = false;
   mutable String16 m_hash;
diff --git a/deps/v8/src/inspector/v8-debugger-script.h b/deps/v8/src/inspector/v8-debugger-script.h
index 164e017610..d4ad784394 100644
--- a/deps/v8/src/inspector/v8-debugger-script.h
+++ b/deps/v8/src/inspector/v8-debugger-script.h
@@ -46,6 +46,7 @@ class V8InspectorClient;
 
 class V8DebuggerScript {
  public:
+  enum class Language { JavaScript, WebAssembly };
   static std::unique_ptr<V8DebuggerScript> Create(
       v8::Isolate* isolate, v8::Local<v8::debug::Script> script,
       bool isLiveEdit, V8DebuggerAgentImpl* agent, V8InspectorClient* client);
@@ -59,11 +60,13 @@ class V8DebuggerScript {
   virtual const String16& sourceMappingURL() const = 0;
   virtual String16 source(size_t pos, size_t len = UINT_MAX) const = 0;
   virtual v8::Maybe<v8::MemorySpan<const uint8_t>> wasmBytecode() const = 0;
+  virtual Language getLanguage() const = 0;
   virtual const String16& hash() const = 0;
   virtual int startLine() const = 0;
   virtual int startColumn() const = 0;
   virtual int endLine() const = 0;
   virtual int endColumn() const = 0;
+  virtual int codeOffset() const = 0;
   int executionContextId() const { return m_executionContextId; }
   virtual bool isLiveEdit() const = 0;
   virtual bool isModule() const = 0;
diff --git a/deps/v8/src/inspector/v8-debugger.cc b/deps/v8/src/inspector/v8-debugger.cc
index 3bdbba80b1..4a2119ff1c 100644
--- a/deps/v8/src/inspector/v8-debugger.cc
+++ b/deps/v8/src/inspector/v8-debugger.cc
@@ -124,6 +124,7 @@ void V8Debugger::enable() {
   m_isolate->AddNearHeapLimitCallback(&V8Debugger::nearHeapLimitCallback, this);
   v8::debug::ChangeBreakOnException(m_isolate, v8::debug::NoBreakOnException);
   m_pauseOnExceptionsState = v8::debug::NoBreakOnException;
+  v8::debug::TierDownAllModulesPerIsolate(m_isolate);
 }
 
 void V8Debugger::disable() {
@@ -146,6 +147,7 @@ void V8Debugger::disable() {
   m_taskWithScheduledBreakPauseRequested = false;
   m_pauseOnNextCallRequested = false;
   m_pauseOnAsyncCall = false;
+  v8::debug::TierUpAllModulesPerIsolate(m_isolate);
   v8::debug::SetDebugDelegate(m_isolate, nullptr);
   m_isolate->RemoveNearHeapLimitCallback(&V8Debugger::nearHeapLimitCallback,
                                          m_originalHeapLimit);
@@ -245,9 +247,15 @@ void V8Debugger::interruptAndBreak(int targetContextGroupId) {
       nullptr);
 }
 
-void V8Debugger::continueProgram(int targetContextGroupId) {
+void V8Debugger::continueProgram(int targetContextGroupId,
+                                 bool terminateOnResume) {
   if (m_pausedContextGroupId != targetContextGroupId) return;
-  if (isPaused()) m_inspector->client()->quitMessageLoopOnPause();
+  if (isPaused()) {
+    if (terminateOnResume) {
+      v8::debug::SetTerminateOnResume(m_isolate);
+    }
+    m_inspector->client()->quitMessageLoopOnPause();
+  }
 }
 
 void V8Debugger::breakProgramOnAssert(int targetContextGroupId) {
@@ -295,7 +303,10 @@ bool V8Debugger::asyncStepOutOfFunction(int targetContextGroupId,
                                         bool onlyAtReturn) {
   v8::HandleScope handleScope(m_isolate);
   auto iterator = v8::debug::StackTraceIterator::Create(m_isolate);
-  CHECK(!iterator->Done());
+  // When stepping through extensions code, it is possible that the
+  // iterator doesn't have any frames, since we exclude all frames
+  // that correspond to extension scripts.
+  if (iterator->Done()) return false;
   bool atReturn = !iterator->GetReturnValue().IsEmpty();
   iterator->Advance();
   // Synchronous stack has more then one frame.
@@ -328,8 +339,8 @@ void V8Debugger::terminateExecution(
     std::unique_ptr<TerminateExecutionCallback> callback) {
   if (m_terminateExecutionCallback) {
     if (callback) {
-      callback->sendFailure(
-          Response::Error("There is current termination request in progress"));
+      callback->sendFailure(Response::ServerError(
+          "There is current termination request in progress"));
     }
     return;
   }
@@ -383,9 +394,9 @@ Response V8Debugger::continueToLocation(
     }
     continueProgram(targetContextGroupId);
     // TODO(kozyatinskiy): Return actual line and column number.
-    return Response::OK();
+    return Response::Success();
   } else {
-    return Response::Error("Cannot continue to specified location");
+    return Response::ServerError("Cannot continue to specified location");
   }
 }
 
@@ -674,6 +685,9 @@ v8::MaybeLocal<v8::Value> V8Debugger::getTargetScopes(
       case v8::debug::ScopeIterator::ScopeTypeModule:
         description = "Module" + nameSuffix;
         break;
+      case v8::debug::ScopeIterator::ScopeTypeWasmExpressionStack:
+        description = "Wasm Expression Stack" + nameSuffix;
+        break;
     }
     v8::Local<v8::Object> object = iterator->GetObject();
     createDataProperty(context, scope,
diff --git a/deps/v8/src/inspector/v8-debugger.h b/deps/v8/src/inspector/v8-debugger.h
index f5605818ab..60837f47ca 100644
--- a/deps/v8/src/inspector/v8-debugger.h
+++ b/deps/v8/src/inspector/v8-debugger.h
@@ -77,7 +77,8 @@ class V8Debugger : public v8::debug::DebugDelegate,
   bool canBreakProgram();
   void breakProgram(int targetContextGroupId);
   void interruptAndBreak(int targetContextGroupId);
-  void continueProgram(int targetContextGroupId);
+  void continueProgram(int targetContextGroupId,
+                       bool terminateOnResume = false);
   void breakProgramOnAssert(int targetContextGroupId);
 
   void setPauseOnNextCall(bool, int targetContextGroupId);
diff --git a/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc b/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
index 8bd68cdbc6..3d6035c762 100644
--- a/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-heap-profiler-agent-impl.cc
@@ -173,7 +173,7 @@ void V8HeapProfilerAgentImpl::restore() {
 
 Response V8HeapProfilerAgentImpl::collectGarbage() {
   m_isolate->LowMemoryNotification();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::startTrackingHeapObjects(
@@ -183,7 +183,7 @@ Response V8HeapProfilerAgentImpl::startTrackingHeapObjects(
   m_state->setBoolean(HeapProfilerAgentState::allocationTrackingEnabled,
                       allocationTrackingEnabled);
   startTrackingHeapObjectsInternal(allocationTrackingEnabled);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::stopTrackingHeapObjects(
@@ -192,12 +192,12 @@ Response V8HeapProfilerAgentImpl::stopTrackingHeapObjects(
   takeHeapSnapshot(std::move(reportProgress),
                    std::move(treatGlobalObjectsAsRoots));
   stopTrackingHeapObjectsInternal();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::enable() {
   m_state->setBoolean(HeapProfilerAgentState::heapProfilerEnabled, true);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::disable() {
@@ -209,13 +209,13 @@ Response V8HeapProfilerAgentImpl::disable() {
   }
   m_isolate->GetHeapProfiler()->ClearObjectIds();
   m_state->setBoolean(HeapProfilerAgentState::heapProfilerEnabled, false);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::takeHeapSnapshot(
     Maybe<bool> reportProgress, Maybe<bool> treatGlobalObjectsAsRoots) {
   v8::HeapProfiler* profiler = m_isolate->GetHeapProfiler();
-  if (!profiler) return Response::Error("Cannot access v8 heap profiler");
+  if (!profiler) return Response::ServerError("Cannot access v8 heap profiler");
   std::unique_ptr<HeapSnapshotProgress> progress;
   if (reportProgress.fromMaybe(false))
     progress.reset(new HeapSnapshotProgress(&m_frontend));
@@ -223,11 +223,11 @@ Response V8HeapProfilerAgentImpl::takeHeapSnapshot(
   GlobalObjectNameResolver resolver(m_session);
   const v8::HeapSnapshot* snapshot = profiler->TakeHeapSnapshot(
       progress.get(), &resolver, treatGlobalObjectsAsRoots.fromMaybe(true));
-  if (!snapshot) return Response::Error("Failed to take heap snapshot");
+  if (!snapshot) return Response::ServerError("Failed to take heap snapshot");
   HeapSnapshotOutputStream stream(&m_frontend);
   snapshot->Serialize(&stream);
   const_cast<v8::HeapSnapshot*>(snapshot)->Delete();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::getObjectByHeapObjectId(
@@ -235,36 +235,38 @@ Response V8HeapProfilerAgentImpl::getObjectByHeapObjectId(
     std::unique_ptr<protocol::Runtime::RemoteObject>* result) {
   bool ok;
   int id = heapSnapshotObjectId.toInteger(&ok);
-  if (!ok) return Response::Error("Invalid heap snapshot object id");
+  if (!ok) return Response::ServerError("Invalid heap snapshot object id");
 
   v8::HandleScope handles(m_isolate);
   v8::Local<v8::Object> heapObject = objectByHeapObjectId(m_isolate, id);
-  if (heapObject.IsEmpty()) return Response::Error("Object is not available");
+  if (heapObject.IsEmpty())
+    return Response::ServerError("Object is not available");
 
   if (!m_session->inspector()->client()->isInspectableHeapObject(heapObject))
-    return Response::Error("Object is not available");
+    return Response::ServerError("Object is not available");
 
   *result = m_session->wrapObject(heapObject->CreationContext(), heapObject,
                                   objectGroup.fromMaybe(""), false);
-  if (!*result) return Response::Error("Object is not available");
-  return Response::OK();
+  if (!*result) return Response::ServerError("Object is not available");
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::addInspectedHeapObject(
     const String16& inspectedHeapObjectId) {
   bool ok;
   int id = inspectedHeapObjectId.toInteger(&ok);
-  if (!ok) return Response::Error("Invalid heap snapshot object id");
+  if (!ok) return Response::ServerError("Invalid heap snapshot object id");
 
   v8::HandleScope handles(m_isolate);
   v8::Local<v8::Object> heapObject = objectByHeapObjectId(m_isolate, id);
-  if (heapObject.IsEmpty()) return Response::Error("Object is not available");
+  if (heapObject.IsEmpty())
+    return Response::ServerError("Object is not available");
 
   if (!m_session->inspector()->client()->isInspectableHeapObject(heapObject))
-    return Response::Error("Object is not available");
+    return Response::ServerError("Object is not available");
   m_session->addInspectedObject(
       std::unique_ptr<InspectableHeapObject>(new InspectableHeapObject(id)));
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8HeapProfilerAgentImpl::getHeapObjectId(
@@ -274,12 +276,12 @@ Response V8HeapProfilerAgentImpl::getHeapObjectId(
   v8::Local<v8::Context> context;
   Response response =
       m_session->unwrapObject(objectId, &value, &context, nullptr);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (value->IsUndefined()) return Response::InternalError();
 
   v8::SnapshotObjectId id = m_isolate->GetHeapProfiler()->GetObjectId(value);
   *heapSnapshotObjectId = String16::fromInteger(static_cast<size_t>(id));
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8HeapProfilerAgentImpl::requestHeapStatsUpdate() {
@@ -320,7 +322,7 @@ void V8HeapProfilerAgentImpl::stopTrackingHeapObjectsInternal() {
 Response V8HeapProfilerAgentImpl::startSampling(
     Maybe<double> samplingInterval) {
   v8::HeapProfiler* profiler = m_isolate->GetHeapProfiler();
-  if (!profiler) return Response::Error("Cannot access v8 heap profiler");
+  if (!profiler) return Response::ServerError("Cannot access v8 heap profiler");
   const unsigned defaultSamplingInterval = 1 << 15;
   double samplingIntervalValue =
       samplingInterval.fromMaybe(defaultSamplingInterval);
@@ -331,7 +333,7 @@ Response V8HeapProfilerAgentImpl::startSampling(
   profiler->StartSamplingHeapProfiler(
       static_cast<uint64_t>(samplingIntervalValue), 128,
       v8::HeapProfiler::kSamplingForceGC);
-  return Response::OK();
+  return Response::Success();
 }
 
 namespace {
@@ -367,7 +369,7 @@ buildSampingHeapProfileNode(v8::Isolate* isolate,
 Response V8HeapProfilerAgentImpl::stopSampling(
     std::unique_ptr<protocol::HeapProfiler::SamplingHeapProfile>* profile) {
   Response result = getSamplingProfile(profile);
-  if (result.isSuccess()) {
+  if (result.IsSuccess()) {
     m_isolate->GetHeapProfiler()->StopSamplingHeapProfiler();
     m_state->setBoolean(HeapProfilerAgentState::samplingHeapProfilerEnabled,
                         false);
@@ -383,7 +385,7 @@ Response V8HeapProfilerAgentImpl::getSamplingProfile(
   std::unique_ptr<v8::AllocationProfile> v8Profile(
       profiler->GetAllocationProfile());
   if (!v8Profile)
-    return Response::Error("V8 sampling heap profiler was not started.");
+    return Response::ServerError("V8 sampling heap profiler was not started.");
   v8::AllocationProfile::Node* root = v8Profile->GetRootNode();
   auto samples = std::make_unique<
       protocol::Array<protocol::HeapProfiler::SamplingHeapProfileSample>>();
@@ -399,7 +401,7 @@ Response V8HeapProfilerAgentImpl::getSamplingProfile(
                  .setHead(buildSampingHeapProfileNode(m_isolate, root))
                  .setSamples(std::move(samples))
                  .build();
-  return Response::OK();
+  return Response::Success();
 }
 
 }  // namespace v8_inspector
diff --git a/deps/v8/src/inspector/v8-inspector-impl.cc b/deps/v8/src/inspector/v8-inspector-impl.cc
index c767dbf09d..18c592ef11 100644
--- a/deps/v8/src/inspector/v8-inspector-impl.cc
+++ b/deps/v8/src/inspector/v8-inspector-impl.cc
@@ -155,8 +155,7 @@ std::unique_ptr<V8StackTrace> V8InspectorImpl::createStackTrace(
 }
 
 std::unique_ptr<V8InspectorSession> V8InspectorImpl::connect(
-    int contextGroupId, V8Inspector::Channel* channel,
-    const StringView& state) {
+    int contextGroupId, V8Inspector::Channel* channel, StringView state) {
   int sessionId = ++m_lastSessionId;
   std::unique_ptr<V8InspectorSessionImpl> session =
       V8InspectorSessionImpl::create(this, contextGroupId, sessionId, channel,
@@ -256,9 +255,9 @@ void V8InspectorImpl::idleStarted() { m_isolate->SetIdle(true); }
 void V8InspectorImpl::idleFinished() { m_isolate->SetIdle(false); }
 
 unsigned V8InspectorImpl::exceptionThrown(
-    v8::Local<v8::Context> context, const StringView& message,
-    v8::Local<v8::Value> exception, const StringView& detailedMessage,
-    const StringView& url, unsigned lineNumber, unsigned columnNumber,
+    v8::Local<v8::Context> context, StringView message,
+    v8::Local<v8::Value> exception, StringView detailedMessage, StringView url,
+    unsigned lineNumber, unsigned columnNumber,
     std::unique_ptr<V8StackTrace> stackTrace, int scriptId) {
   int groupId = contextGroupId(context);
   if (!groupId || m_muteExceptionsMap[groupId]) return 0;
@@ -277,7 +276,7 @@ unsigned V8InspectorImpl::exceptionThrown(
 
 void V8InspectorImpl::exceptionRevoked(v8::Local<v8::Context> context,
                                        unsigned exceptionId,
-                                       const StringView& message) {
+                                       StringView message) {
   int groupId = contextGroupId(context);
   if (!groupId) return;
 
@@ -292,8 +291,7 @@ std::unique_ptr<V8StackTrace> V8InspectorImpl::captureStackTrace(
   return m_debugger->captureStackTrace(fullStack);
 }
 
-V8StackTraceId V8InspectorImpl::storeCurrentStackTrace(
-    const StringView& description) {
+V8StackTraceId V8InspectorImpl::storeCurrentStackTrace(StringView description) {
   return m_debugger->storeCurrentStackTrace(description);
 }
 
@@ -305,7 +303,7 @@ void V8InspectorImpl::externalAsyncTaskFinished(const V8StackTraceId& parent) {
   m_debugger->externalAsyncTaskFinished(parent);
 }
 
-void V8InspectorImpl::asyncTaskScheduled(const StringView& taskName, void* task,
+void V8InspectorImpl::asyncTaskScheduled(StringView taskName, void* task,
                                          bool recurring) {
   if (!task) return;
   m_debugger->asyncTaskScheduled(taskName, task, recurring);
@@ -467,12 +465,12 @@ class V8InspectorImpl::EvaluateScope::TerminateTask : public v8::Task {
 
 protocol::Response V8InspectorImpl::EvaluateScope::setTimeout(double timeout) {
   if (m_isolate->IsExecutionTerminating()) {
-    return protocol::Response::Error("Execution was terminated");
+    return protocol::Response::ServerError("Execution was terminated");
   }
   m_cancelToken.reset(new CancelToken());
   v8::debug::GetCurrentPlatform()->CallDelayedOnWorkerThread(
       std::make_unique<TerminateTask>(m_isolate, m_cancelToken), timeout);
-  return protocol::Response::OK();
+  return protocol::Response::Success();
 }
 
 }  // namespace v8_inspector
diff --git a/deps/v8/src/inspector/v8-inspector-impl.h b/deps/v8/src/inspector/v8-inspector-impl.h
index dce3db52bd..43e3369953 100644
--- a/deps/v8/src/inspector/v8-inspector-impl.h
+++ b/deps/v8/src/inspector/v8-inspector-impl.h
@@ -77,7 +77,7 @@ class V8InspectorImpl : public V8Inspector {
   // V8Inspector implementation.
   std::unique_ptr<V8InspectorSession> connect(int contextGroupId,
                                               V8Inspector::Channel*,
-                                              const StringView& state) override;
+                                              StringView state) override;
   void contextCreated(const V8ContextInfo&) override;
   void contextDestroyed(v8::Local<v8::Context>) override;
   v8::MaybeLocal<v8::Context> contextById(int contextId) override;
@@ -85,25 +85,25 @@ class V8InspectorImpl : public V8Inspector {
   void resetContextGroup(int contextGroupId) override;
   void idleStarted() override;
   void idleFinished() override;
-  unsigned exceptionThrown(v8::Local<v8::Context>, const StringView& message,
+  unsigned exceptionThrown(v8::Local<v8::Context>, StringView message,
                            v8::Local<v8::Value> exception,
-                           const StringView& detailedMessage,
-                           const StringView& url, unsigned lineNumber,
-                           unsigned columnNumber, std::unique_ptr<V8StackTrace>,
+                           StringView detailedMessage, StringView url,
+                           unsigned lineNumber, unsigned columnNumber,
+                           std::unique_ptr<V8StackTrace>,
                            int scriptId) override;
   void exceptionRevoked(v8::Local<v8::Context>, unsigned exceptionId,
-                        const StringView& message) override;
+                        StringView message) override;
   std::unique_ptr<V8StackTrace> createStackTrace(
       v8::Local<v8::StackTrace>) override;
   std::unique_ptr<V8StackTrace> captureStackTrace(bool fullStack) override;
-  void asyncTaskScheduled(const StringView& taskName, void* task,
+  void asyncTaskScheduled(StringView taskName, void* task,
                           bool recurring) override;
   void asyncTaskCanceled(void* task) override;
   void asyncTaskStarted(void* task) override;
   void asyncTaskFinished(void* task) override;
   void allAsyncTasksCanceled() override;
 
-  V8StackTraceId storeCurrentStackTrace(const StringView& description) override;
+  V8StackTraceId storeCurrentStackTrace(StringView description) override;
   void externalAsyncTaskStarted(const V8StackTraceId& parent) override;
   void externalAsyncTaskFinished(const V8StackTraceId& parent) override;
 
diff --git a/deps/v8/src/inspector/v8-inspector-session-impl.cc b/deps/v8/src/inspector/v8-inspector-session-impl.cc
index 45881a4596..3bdc3e80c2 100644
--- a/deps/v8/src/inspector/v8-inspector-session-impl.cc
+++ b/deps/v8/src/inspector/v8-inspector-session-impl.cc
@@ -5,6 +5,7 @@
 #include "src/inspector/v8-inspector-session-impl.h"
 
 #include "../../third_party/inspector_protocol/crdtp/cbor.h"
+#include "../../third_party/inspector_protocol/crdtp/dispatch.h"
 #include "../../third_party/inspector_protocol/crdtp/json.h"
 #include "src/base/logging.h"
 #include "src/base/macros.h"
@@ -32,12 +33,12 @@ using v8_crdtp::cbor::CheckCBORMessage;
 using v8_crdtp::json::ConvertCBORToJSON;
 using v8_crdtp::json::ConvertJSONToCBOR;
 
-bool IsCBORMessage(const StringView& msg) {
+bool IsCBORMessage(StringView msg) {
   return msg.is8Bit() && msg.length() >= 2 && msg.characters8()[0] == 0xd8 &&
          msg.characters8()[1] == 0x5a;
 }
 
-Status ConvertToCBOR(const StringView& state, std::vector<uint8_t>* cbor) {
+Status ConvertToCBOR(StringView state, std::vector<uint8_t>* cbor) {
   return state.is8Bit()
              ? ConvertJSONToCBOR(
                    span<uint8_t>(state.characters8(), state.length()), cbor)
@@ -45,7 +46,7 @@ Status ConvertToCBOR(const StringView& state, std::vector<uint8_t>* cbor) {
                    span<uint16_t>(state.characters16(), state.length()), cbor);
 }
 
-std::unique_ptr<protocol::DictionaryValue> ParseState(const StringView& state) {
+std::unique_ptr<protocol::DictionaryValue> ParseState(StringView state) {
   std::vector<uint8_t> converted;
   span<uint8_t> cbor;
   if (IsCBORMessage(state))
@@ -62,7 +63,7 @@ std::unique_ptr<protocol::DictionaryValue> ParseState(const StringView& state) {
 }  // namespace
 
 // static
-bool V8InspectorSession::canDispatchMethod(const StringView& method) {
+bool V8InspectorSession::canDispatchMethod(StringView method) {
   return stringViewStartsWith(method,
                               protocol::Runtime::Metainfo::commandPrefix) ||
          stringViewStartsWith(method,
@@ -84,7 +85,7 @@ int V8ContextInfo::executionContextId(v8::Local<v8::Context> context) {
 
 std::unique_ptr<V8InspectorSessionImpl> V8InspectorSessionImpl::create(
     V8InspectorImpl* inspector, int contextGroupId, int sessionId,
-    V8Inspector::Channel* channel, const StringView& state) {
+    V8Inspector::Channel* channel, StringView state) {
   return std::unique_ptr<V8InspectorSessionImpl>(new V8InspectorSessionImpl(
       inspector, contextGroupId, sessionId, channel, state));
 }
@@ -93,7 +94,7 @@ V8InspectorSessionImpl::V8InspectorSessionImpl(V8InspectorImpl* inspector,
                                                int contextGroupId,
                                                int sessionId,
                                                V8Inspector::Channel* channel,
-                                               const StringView& savedState)
+                                               StringView savedState)
     : m_contextGroupId(contextGroupId),
       m_sessionId(sessionId),
       m_inspector(inspector),
@@ -167,7 +168,7 @@ protocol::DictionaryValue* V8InspectorSessionImpl::agentState(
 
 std::unique_ptr<StringBuffer> V8InspectorSessionImpl::serializeForFrontend(
     std::unique_ptr<protocol::Serializable> message) {
-  std::vector<uint8_t> cbor = std::move(*message).TakeSerialized();
+  std::vector<uint8_t> cbor = message->Serialize();
   DCHECK(CheckCBORMessage(SpanFrom(cbor)).ok());
   if (use_binary_protocol_) return StringBufferFrom(std::move(cbor));
   std::vector<uint8_t> json;
@@ -184,23 +185,24 @@ std::unique_ptr<StringBuffer> V8InspectorSessionImpl::serializeForFrontend(
   return StringBufferFrom(std::move(string16));
 }
 
-void V8InspectorSessionImpl::sendProtocolResponse(
+void V8InspectorSessionImpl::SendProtocolResponse(
     int callId, std::unique_ptr<protocol::Serializable> message) {
   m_channel->sendResponse(callId, serializeForFrontend(std::move(message)));
 }
 
-void V8InspectorSessionImpl::sendProtocolNotification(
+void V8InspectorSessionImpl::SendProtocolNotification(
     std::unique_ptr<protocol::Serializable> message) {
   m_channel->sendNotification(serializeForFrontend(std::move(message)));
 }
 
-void V8InspectorSessionImpl::fallThrough(int callId, const String16& method,
+void V8InspectorSessionImpl::FallThrough(int callId,
+                                         const v8_crdtp::span<uint8_t> method,
                                          v8_crdtp::span<uint8_t> message) {
   // There's no other layer to handle the command.
   UNREACHABLE();
 }
 
-void V8InspectorSessionImpl::flushProtocolNotifications() {
+void V8InspectorSessionImpl::FlushProtocolNotifications() {
   m_channel->flushProtocolNotifications();
 }
 
@@ -224,14 +226,15 @@ Response V8InspectorSessionImpl::findInjectedScript(
   injectedScript = nullptr;
   InspectedContext* context =
       m_inspector->getContext(m_contextGroupId, contextId);
-  if (!context) return Response::Error("Cannot find context with specified id");
+  if (!context)
+    return Response::ServerError("Cannot find context with specified id");
   injectedScript = context->getInjectedScript(m_sessionId);
   if (!injectedScript) {
     injectedScript = context->createInjectedScript(m_sessionId);
     if (m_customObjectFormatterEnabled)
       injectedScript->setCustomObjectFormatterEnabled(true);
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8InspectorSessionImpl::findInjectedScript(
@@ -239,7 +242,7 @@ Response V8InspectorSessionImpl::findInjectedScript(
   return findInjectedScript(objectId->contextId(), injectedScript);
 }
 
-void V8InspectorSessionImpl::releaseObjectGroup(const StringView& objectGroup) {
+void V8InspectorSessionImpl::releaseObjectGroup(StringView objectGroup) {
   releaseObjectGroup(toString16(objectGroup));
 }
 
@@ -253,14 +256,17 @@ void V8InspectorSessionImpl::releaseObjectGroup(const String16& objectGroup) {
 }
 
 bool V8InspectorSessionImpl::unwrapObject(
-    std::unique_ptr<StringBuffer>* error, const StringView& objectId,
+    std::unique_ptr<StringBuffer>* error, StringView objectId,
     v8::Local<v8::Value>* object, v8::Local<v8::Context>* context,
     std::unique_ptr<StringBuffer>* objectGroup) {
   String16 objectGroupString;
   Response response = unwrapObject(toString16(objectId), object, context,
                                    objectGroup ? &objectGroupString : nullptr);
-  if (!response.isSuccess()) {
-    if (error) *error = StringBufferFrom(response.errorMessage());
+  if (response.IsError()) {
+    if (error) {
+      const std::string& msg = response.Message();
+      *error = StringBufferFrom(String16::fromUTF8(msg.data(), msg.size()));
+    }
     return false;
   }
   if (objectGroup)
@@ -274,22 +280,21 @@ Response V8InspectorSessionImpl::unwrapObject(const String16& objectId,
                                               String16* objectGroup) {
   std::unique_ptr<RemoteObjectId> remoteId;
   Response response = RemoteObjectId::parse(objectId, &remoteId);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   InjectedScript* injectedScript = nullptr;
   response = findInjectedScript(remoteId.get(), injectedScript);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   response = injectedScript->findObject(*remoteId, object);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   *context = injectedScript->context()->context();
   if (objectGroup) *objectGroup = injectedScript->objectGroupName(*remoteId);
-  return Response::OK();
+  return Response::Success();
 }
 
 std::unique_ptr<protocol::Runtime::API::RemoteObject>
 V8InspectorSessionImpl::wrapObject(v8::Local<v8::Context> context,
                                    v8::Local<v8::Value> value,
-                                   const StringView& groupName,
-                                   bool generatePreview) {
+                                   StringView groupName, bool generatePreview) {
   return wrapObject(context, value, toString16(groupName), generatePreview);
 }
 
@@ -336,8 +341,7 @@ void V8InspectorSessionImpl::reportAllContexts(V8RuntimeAgentImpl* agent) {
                               });
 }
 
-void V8InspectorSessionImpl::dispatchProtocolMessage(
-    const StringView& message) {
+void V8InspectorSessionImpl::dispatchProtocolMessage(StringView message) {
   using v8_crdtp::span;
   using v8_crdtp::SpanFrom;
   span<uint8_t> cbor;
@@ -347,32 +351,35 @@ void V8InspectorSessionImpl::dispatchProtocolMessage(
     m_state->setBoolean("use_binary_protocol", true);
     cbor = span<uint8_t>(message.characters8(), message.length());
   } else {
-    if (message.is8Bit()) {
-      // We're ignoring the return value of these conversion functions
-      // intentionally. It means the |parsed_message| below will be nullptr.
-      ConvertJSONToCBOR(span<uint8_t>(message.characters8(), message.length()),
-                        &converted_cbor);
-    } else {
-      ConvertJSONToCBOR(
-          span<uint16_t>(message.characters16(), message.length()),
-          &converted_cbor);
+    // We're ignoring the return value of the conversion function
+    // intentionally. It means the |parsed_message| below will be nullptr.
+    auto status = ConvertToCBOR(message, &converted_cbor);
+    if (!status.ok()) {
+      m_channel->sendNotification(
+          serializeForFrontend(v8_crdtp::CreateErrorNotification(
+              v8_crdtp::DispatchResponse::ParseError(status.ToASCIIString()))));
+      return;
     }
     cbor = SpanFrom(converted_cbor);
   }
-  int callId;
-  std::unique_ptr<protocol::Value> parsed_message =
-      protocol::Value::parseBinary(cbor.data(), cbor.size());
-  String16 method;
-  if (m_dispatcher.parseCommand(parsed_message.get(), &callId, &method)) {
-    // Pass empty string instead of the actual message to save on a conversion.
-    // We're allowed to do so because fall-through is not implemented.
-    m_dispatcher.dispatch(callId, method, std::move(parsed_message),
-                          v8_crdtp::span<uint8_t>());
+  v8_crdtp::Dispatchable dispatchable(cbor);
+  if (!dispatchable.ok()) {
+    if (dispatchable.HasCallId()) {
+      m_channel->sendNotification(serializeForFrontend(
+          v8_crdtp::CreateErrorNotification(dispatchable.DispatchError())));
+    } else {
+      m_channel->sendResponse(
+          dispatchable.CallId(),
+          serializeForFrontend(v8_crdtp::CreateErrorResponse(
+              dispatchable.CallId(), dispatchable.DispatchError())));
+    }
+    return;
   }
+  m_dispatcher.Dispatch(dispatchable).Run();
 }
 
 std::vector<uint8_t> V8InspectorSessionImpl::state() {
-  return std::move(*m_state).TakeSerialized();
+  return m_state->Serialize();
 }
 
 std::vector<std::unique_ptr<protocol::Schema::API::Domain>>
@@ -425,36 +432,41 @@ V8InspectorSession::Inspectable* V8InspectorSessionImpl::inspectedObject(
 }
 
 void V8InspectorSessionImpl::schedulePauseOnNextStatement(
-    const StringView& breakReason, const StringView& breakDetails) {
+    StringView breakReason, StringView breakDetails) {
+  std::vector<uint8_t> cbor;
+  ConvertToCBOR(breakDetails, &cbor);
   m_debuggerAgent->schedulePauseOnNextStatement(
       toString16(breakReason),
       protocol::DictionaryValue::cast(
-          protocol::StringUtil::parseJSON(breakDetails)));
+          protocol::Value::parseBinary(cbor.data(), cbor.size())));
 }
 
 void V8InspectorSessionImpl::cancelPauseOnNextStatement() {
   m_debuggerAgent->cancelPauseOnNextStatement();
 }
 
-void V8InspectorSessionImpl::breakProgram(const StringView& breakReason,
-                                          const StringView& breakDetails) {
+void V8InspectorSessionImpl::breakProgram(StringView breakReason,
+                                          StringView breakDetails) {
+  std::vector<uint8_t> cbor;
+  ConvertToCBOR(breakDetails, &cbor);
   m_debuggerAgent->breakProgram(
       toString16(breakReason),
       protocol::DictionaryValue::cast(
-          protocol::StringUtil::parseJSON(breakDetails)));
+          protocol::Value::parseBinary(cbor.data(), cbor.size())));
 }
 
 void V8InspectorSessionImpl::setSkipAllPauses(bool skip) {
   m_debuggerAgent->setSkipAllPauses(skip);
 }
 
-void V8InspectorSessionImpl::resume() { m_debuggerAgent->resume(); }
+void V8InspectorSessionImpl::resume(bool terminateOnResume) {
+  m_debuggerAgent->resume(terminateOnResume);
+}
 
 void V8InspectorSessionImpl::stepOver() { m_debuggerAgent->stepOver(); }
 
 std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
-V8InspectorSessionImpl::searchInTextByLines(const StringView& text,
-                                            const StringView& query,
+V8InspectorSessionImpl::searchInTextByLines(StringView text, StringView query,
                                             bool caseSensitive, bool isRegex) {
   // TODO(dgozman): search may operate on StringView and avoid copying |text|.
   std::vector<std::unique_ptr<protocol::Debugger::SearchMatch>> matches =
@@ -467,7 +479,7 @@ V8InspectorSessionImpl::searchInTextByLines(const StringView& text,
 }
 
 void V8InspectorSessionImpl::triggerPreciseCoverageDeltaUpdate(
-    const StringView& occassion) {
+    StringView occassion) {
   m_profilerAgent->triggerPreciseCoverageDeltaUpdate(toString16(occassion));
 }
 
diff --git a/deps/v8/src/inspector/v8-inspector-session-impl.h b/deps/v8/src/inspector/v8-inspector-session-impl.h
index 31b822c47d..b3fce48df7 100644
--- a/deps/v8/src/inspector/v8-inspector-session-impl.h
+++ b/deps/v8/src/inspector/v8-inspector-session-impl.h
@@ -32,9 +32,11 @@ using protocol::Response;
 class V8InspectorSessionImpl : public V8InspectorSession,
                                public protocol::FrontendChannel {
  public:
-  static std::unique_ptr<V8InspectorSessionImpl> create(
-      V8InspectorImpl*, int contextGroupId, int sessionId,
-      V8Inspector::Channel*, const StringView& state);
+  static std::unique_ptr<V8InspectorSessionImpl> create(V8InspectorImpl*,
+                                                        int contextGroupId,
+                                                        int sessionId,
+                                                        V8Inspector::Channel*,
+                                                        StringView state);
   ~V8InspectorSessionImpl() override;
 
   V8InspectorImpl* inspector() const { return m_inspector; }
@@ -64,49 +66,48 @@ class V8InspectorSessionImpl : public V8InspectorSession,
   void releaseObjectGroup(const String16& objectGroup);
 
   // V8InspectorSession implementation.
-  void dispatchProtocolMessage(const StringView& message) override;
+  void dispatchProtocolMessage(StringView message) override;
   std::vector<uint8_t> state() override;
   std::vector<std::unique_ptr<protocol::Schema::API::Domain>> supportedDomains()
       override;
   void addInspectedObject(
       std::unique_ptr<V8InspectorSession::Inspectable>) override;
-  void schedulePauseOnNextStatement(const StringView& breakReason,
-                                    const StringView& breakDetails) override;
+  void schedulePauseOnNextStatement(StringView breakReason,
+                                    StringView breakDetails) override;
   void cancelPauseOnNextStatement() override;
-  void breakProgram(const StringView& breakReason,
-                    const StringView& breakDetails) override;
+  void breakProgram(StringView breakReason, StringView breakDetails) override;
   void setSkipAllPauses(bool) override;
-  void resume() override;
+  void resume(bool terminateOnResume = false) override;
   void stepOver() override;
   std::vector<std::unique_ptr<protocol::Debugger::API::SearchMatch>>
-  searchInTextByLines(const StringView& text, const StringView& query,
-                      bool caseSensitive, bool isRegex) override;
-  void releaseObjectGroup(const StringView& objectGroup) override;
-  bool unwrapObject(std::unique_ptr<StringBuffer>*, const StringView& objectId,
+  searchInTextByLines(StringView text, StringView query, bool caseSensitive,
+                      bool isRegex) override;
+  void releaseObjectGroup(StringView objectGroup) override;
+  bool unwrapObject(std::unique_ptr<StringBuffer>*, StringView objectId,
                     v8::Local<v8::Value>*, v8::Local<v8::Context>*,
                     std::unique_ptr<StringBuffer>* objectGroup) override;
   std::unique_ptr<protocol::Runtime::API::RemoteObject> wrapObject(
-      v8::Local<v8::Context>, v8::Local<v8::Value>, const StringView& groupName,
+      v8::Local<v8::Context>, v8::Local<v8::Value>, StringView groupName,
       bool generatePreview) override;
 
   V8InspectorSession::Inspectable* inspectedObject(unsigned num);
   static const unsigned kInspectedObjectBufferSize = 5;
 
-  void triggerPreciseCoverageDeltaUpdate(const StringView& occassion) override;
+  void triggerPreciseCoverageDeltaUpdate(StringView occassion) override;
 
  private:
   V8InspectorSessionImpl(V8InspectorImpl*, int contextGroupId, int sessionId,
-                         V8Inspector::Channel*, const StringView& state);
+                         V8Inspector::Channel*, StringView state);
   protocol::DictionaryValue* agentState(const String16& name);
 
   // protocol::FrontendChannel implementation.
-  void sendProtocolResponse(
+  void SendProtocolResponse(
       int callId, std::unique_ptr<protocol::Serializable> message) override;
-  void sendProtocolNotification(
+  void SendProtocolNotification(
       std::unique_ptr<protocol::Serializable> message) override;
-  void fallThrough(int callId, const String16& method,
+  void FallThrough(int callId, v8_crdtp::span<uint8_t> method,
                    v8_crdtp::span<uint8_t> message) override;
-  void flushProtocolNotifications() override;
+  void FlushProtocolNotifications() override;
 
   std::unique_ptr<StringBuffer> serializeForFrontend(
       std::unique_ptr<protocol::Serializable> message);
diff --git a/deps/v8/src/inspector/v8-profiler-agent-impl.cc b/deps/v8/src/inspector/v8-profiler-agent-impl.cc
index 58d83aa948..873add9a19 100644
--- a/deps/v8/src/inspector/v8-profiler-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-profiler-agent-impl.cc
@@ -27,8 +27,10 @@ static const char profilerEnabled[] = "profilerEnabled";
 static const char preciseCoverageStarted[] = "preciseCoverageStarted";
 static const char preciseCoverageCallCount[] = "preciseCoverageCallCount";
 static const char preciseCoverageDetailed[] = "preciseCoverageDetailed";
+static const char preciseCoverageAllowTriggeredUpdates[] =
+    "preciseCoverageAllowTriggeredUpdates";
 static const char typeProfileStarted[] = "typeProfileStarted";
-}
+}  // namespace ProfilerAgentState
 
 namespace {
 
@@ -218,14 +220,14 @@ void V8ProfilerAgentImpl::consoleProfileEnd(const String16& title) {
 }
 
 Response V8ProfilerAgentImpl::enable() {
-  if (m_enabled) return Response::OK();
+  if (m_enabled) return Response::Success();
   m_enabled = true;
   m_state->setBoolean(ProfilerAgentState::profilerEnabled, true);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::disable() {
-  if (!m_enabled) return Response::OK();
+  if (!m_enabled) return Response::Success();
   for (size_t i = m_startedProfiles.size(); i > 0; --i)
     stopProfiling(m_startedProfiles[i - 1].m_id, false);
   m_startedProfiles.clear();
@@ -234,15 +236,16 @@ Response V8ProfilerAgentImpl::disable() {
   DCHECK(!m_profiler);
   m_enabled = false;
   m_state->setBoolean(ProfilerAgentState::profilerEnabled, false);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::setSamplingInterval(int interval) {
   if (m_profiler) {
-    return Response::Error("Cannot change sampling interval when profiling.");
+    return Response::ServerError(
+        "Cannot change sampling interval when profiling.");
   }
   m_state->setInteger(ProfilerAgentState::samplingInterval, interval);
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8ProfilerAgentImpl::restore() {
@@ -261,52 +264,57 @@ void V8ProfilerAgentImpl::restore() {
         ProfilerAgentState::preciseCoverageCallCount, false);
     bool detailed = m_state->booleanProperty(
         ProfilerAgentState::preciseCoverageDetailed, false);
+    bool updatesAllowed = m_state->booleanProperty(
+        ProfilerAgentState::preciseCoverageAllowTriggeredUpdates, false);
     double timestamp;
     startPreciseCoverage(Maybe<bool>(callCount), Maybe<bool>(detailed),
-                         &timestamp);
+                         Maybe<bool>(updatesAllowed), &timestamp);
   }
 }
 
 Response V8ProfilerAgentImpl::start() {
-  if (m_recordingCPUProfile) return Response::OK();
-  if (!m_enabled) return Response::Error("Profiler is not enabled");
+  if (m_recordingCPUProfile) return Response::Success();
+  if (!m_enabled) return Response::ServerError("Profiler is not enabled");
   m_recordingCPUProfile = true;
   m_frontendInitiatedProfileId = nextProfileId();
   startProfiling(m_frontendInitiatedProfileId);
   m_state->setBoolean(ProfilerAgentState::userInitiatedProfiling, true);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::stop(
     std::unique_ptr<protocol::Profiler::Profile>* profile) {
   if (!m_recordingCPUProfile) {
-    return Response::Error("No recording profiles found");
+    return Response::ServerError("No recording profiles found");
   }
   m_recordingCPUProfile = false;
   std::unique_ptr<protocol::Profiler::Profile> cpuProfile =
       stopProfiling(m_frontendInitiatedProfileId, !!profile);
   if (profile) {
     *profile = std::move(cpuProfile);
-    if (!profile->get()) return Response::Error("Profile is not found");
+    if (!profile->get()) return Response::ServerError("Profile is not found");
   }
   m_frontendInitiatedProfileId = String16();
   m_state->setBoolean(ProfilerAgentState::userInitiatedProfiling, false);
-  return Response::OK();
+  return Response::Success();
 }
 
-Response V8ProfilerAgentImpl::startPreciseCoverage(Maybe<bool> callCount,
-                                                   Maybe<bool> detailed,
-                                                   double* out_timestamp) {
-  if (!m_enabled) return Response::Error("Profiler is not enabled");
+Response V8ProfilerAgentImpl::startPreciseCoverage(
+    Maybe<bool> callCount, Maybe<bool> detailed,
+    Maybe<bool> allowTriggeredUpdates, double* out_timestamp) {
+  if (!m_enabled) return Response::ServerError("Profiler is not enabled");
   *out_timestamp =
       v8::base::TimeTicks::HighResolutionNow().since_origin().InSecondsF();
   bool callCountValue = callCount.fromMaybe(false);
   bool detailedValue = detailed.fromMaybe(false);
+  bool allowTriggeredUpdatesValue = allowTriggeredUpdates.fromMaybe(false);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageStarted, true);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageCallCount,
                       callCountValue);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageDetailed,
                       detailedValue);
+  m_state->setBoolean(ProfilerAgentState::preciseCoverageAllowTriggeredUpdates,
+                      allowTriggeredUpdatesValue);
   // BlockCount is a superset of PreciseCount. It includes block-granularity
   // coverage data if it exists (at the time of writing, that's the case for
   // each function recompiled after the BlockCount mode has been set); and
@@ -317,17 +325,17 @@ Response V8ProfilerAgentImpl::startPreciseCoverage(Maybe<bool> callCount,
                   ? (detailedValue ? Mode::kBlockCount : Mode::kPreciseCount)
                   : (detailedValue ? Mode::kBlockBinary : Mode::kPreciseBinary);
   C::SelectMode(m_isolate, mode);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::stopPreciseCoverage() {
-  if (!m_enabled) return Response::Error("Profiler is not enabled");
+  if (!m_enabled) return Response::ServerError("Profiler is not enabled");
   m_state->setBoolean(ProfilerAgentState::preciseCoverageStarted, false);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageCallCount, false);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageDetailed, false);
   v8::debug::Coverage::SelectMode(m_isolate,
                                   v8::debug::CoverageMode::kBestEffort);
-  return Response::OK();
+  return Response::Success();
 }
 
 namespace {
@@ -395,7 +403,7 @@ Response coverageToProtocol(
                              .build());
   }
   *out_result = std::move(result);
-  return Response::OK();
+  return Response::Success();
 }
 }  // anonymous namespace
 
@@ -405,7 +413,7 @@ Response V8ProfilerAgentImpl::takePreciseCoverage(
     double* out_timestamp) {
   if (!m_state->booleanProperty(ProfilerAgentState::preciseCoverageStarted,
                                 false)) {
-    return Response::Error("Precise coverage has not been started.");
+    return Response::ServerError("Precise coverage has not been started.");
   }
   v8::HandleScope handle_scope(m_isolate);
   v8::debug::Coverage coverage = v8::debug::Coverage::CollectPrecise(m_isolate);
@@ -420,6 +428,10 @@ void V8ProfilerAgentImpl::triggerPreciseCoverageDeltaUpdate(
                                 false)) {
     return;
   }
+  if (!m_state->booleanProperty(
+          ProfilerAgentState::preciseCoverageAllowTriggeredUpdates, false)) {
+    return;
+  }
   v8::HandleScope handle_scope(m_isolate);
   v8::debug::Coverage coverage = v8::debug::Coverage::CollectPrecise(m_isolate);
   std::unique_ptr<protocol::Array<protocol::Profiler::ScriptCoverage>>
@@ -489,14 +501,14 @@ Response V8ProfilerAgentImpl::startTypeProfile() {
   m_state->setBoolean(ProfilerAgentState::typeProfileStarted, true);
   v8::debug::TypeProfile::SelectMode(m_isolate,
                                      v8::debug::TypeProfileMode::kCollect);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::stopTypeProfile() {
   m_state->setBoolean(ProfilerAgentState::typeProfileStarted, false);
   v8::debug::TypeProfile::SelectMode(m_isolate,
                                      v8::debug::TypeProfileMode::kNone);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::takeTypeProfile(
@@ -504,37 +516,38 @@ Response V8ProfilerAgentImpl::takeTypeProfile(
         out_result) {
   if (!m_state->booleanProperty(ProfilerAgentState::typeProfileStarted,
                                 false)) {
-    return Response::Error("Type profile has not been started.");
+    return Response::ServerError("Type profile has not been started.");
   }
   v8::HandleScope handle_scope(m_isolate);
   v8::debug::TypeProfile type_profile =
       v8::debug::TypeProfile::Collect(m_isolate);
   *out_result = typeProfileToProtocol(m_session->inspector(), type_profile);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::enableRuntimeCallStats() {
   if (m_counters)
-    return Response::Error("RuntimeCallStats collection already enabled.");
+    return Response::ServerError(
+        "RuntimeCallStats collection already enabled.");
 
   if (V8Inspector* inspector = v8::debug::GetInspector(m_isolate))
     m_counters = inspector->enableCounters();
   else
-    return Response::Error("No inspector found.");
+    return Response::ServerError("No inspector found.");
 
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::disableRuntimeCallStats() {
   if (m_counters) m_counters.reset();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8ProfilerAgentImpl::getRuntimeCallStats(
     std::unique_ptr<protocol::Array<protocol::Profiler::CounterInfo>>*
         out_result) {
   if (!m_counters)
-    return Response::Error("RuntimeCallStats collection is not enabled.");
+    return Response::ServerError("RuntimeCallStats collection is not enabled.");
 
   *out_result =
       std::make_unique<protocol::Array<protocol::Profiler::CounterInfo>>();
@@ -548,7 +561,7 @@ Response V8ProfilerAgentImpl::getRuntimeCallStats(
                 .build());
   }
 
-  return Response::OK();
+  return Response::Success();
 }
 
 String16 V8ProfilerAgentImpl::nextProfileId() {
diff --git a/deps/v8/src/inspector/v8-profiler-agent-impl.h b/deps/v8/src/inspector/v8-profiler-agent-impl.h
index 74d7069efc..08d76ce587 100644
--- a/deps/v8/src/inspector/v8-profiler-agent-impl.h
+++ b/deps/v8/src/inspector/v8-profiler-agent-impl.h
@@ -40,6 +40,7 @@ class V8ProfilerAgentImpl : public protocol::Profiler::Backend {
   Response stop(std::unique_ptr<protocol::Profiler::Profile>*) override;
 
   Response startPreciseCoverage(Maybe<bool> binary, Maybe<bool> detailed,
+                                Maybe<bool> allow_triggered_updates,
                                 double* out_timestamp) override;
   Response stopPreciseCoverage() override;
   Response takePreciseCoverage(
diff --git a/deps/v8/src/inspector/v8-runtime-agent-impl.cc b/deps/v8/src/inspector/v8-runtime-agent-impl.cc
index ed6cebea7c..5a2a49154c 100644
--- a/deps/v8/src/inspector/v8-runtime-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-runtime-agent-impl.cc
@@ -32,6 +32,7 @@
 
 #include <inttypes.h>
 
+#include "../../third_party/inspector_protocol/crdtp/json.h"
 #include "src/debug/debug-interface.h"
 #include "src/inspector/injected-script.h"
 #include "src/inspector/inspected-context.h"
@@ -98,7 +99,7 @@ bool wrapEvaluateResultAsync(InjectedScript* injectedScript,
   Response response = injectedScript->wrapEvaluateResult(
       maybeResultValue, tryCatch, objectGroup, wrapMode, &result,
       &exceptionDetails);
-  if (response.isSuccess()) {
+  if (response.IsSuccess()) {
     callback->sendSuccess(std::move(result), std::move(exceptionDetails));
     return true;
   }
@@ -127,7 +128,7 @@ void innerCallFunctionOn(
       v8::Local<v8::Value> argumentValue;
       Response response = scope.injectedScript()->resolveCallArgument(
           (*arguments)[i].get(), &argumentValue);
-      if (!response.isSuccess()) {
+      if (!response.IsSuccess()) {
         callback->sendFailure(response);
         return;
       }
@@ -153,7 +154,7 @@ void innerCallFunctionOn(
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.
   Response response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -168,8 +169,8 @@ void innerCallFunctionOn(
   v8::Local<v8::Value> functionValue;
   if (!maybeFunctionValue.ToLocal(&functionValue) ||
       !functionValue->IsFunction()) {
-    callback->sendFailure(
-        Response::Error("Given expression does not evaluate to a function"));
+    callback->sendFailure(Response::ServerError(
+        "Given expression does not evaluate to a function"));
     return;
   }
 
@@ -183,7 +184,7 @@ void innerCallFunctionOn(
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.
   response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -210,10 +211,10 @@ Response ensureContext(V8InspectorImpl* inspector, int contextGroupId,
     v8::Local<v8::Context> defaultContext =
         inspector->client()->ensureDefaultContextInGroup(contextGroupId);
     if (defaultContext.IsEmpty())
-      return Response::Error("Cannot find default execution context");
+      return Response::ServerError("Cannot find default execution context");
     *contextId = InspectedContext::contextId(defaultContext);
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 }  // namespace
@@ -242,14 +243,14 @@ void V8RuntimeAgentImpl::evaluate(
   int contextId = 0;
   Response response = ensureContext(m_inspector, m_session->contextGroupId(),
                                     std::move(executionContextId), &contextId);
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
 
   InjectedScript::ContextScope scope(m_session, contextId);
   response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -268,7 +269,7 @@ void V8RuntimeAgentImpl::evaluate(
     V8InspectorImpl::EvaluateScope evaluateScope(scope);
     if (timeout.isJust()) {
       response = evaluateScope.setTimeout(timeout.fromJust() / 1000.0);
-      if (!response.isSuccess()) {
+      if (!response.IsSuccess()) {
         callback->sendFailure(response);
         return;
       }
@@ -291,7 +292,7 @@ void V8RuntimeAgentImpl::evaluate(
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.
   response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -319,13 +320,13 @@ void V8RuntimeAgentImpl::awaitPromise(
     std::unique_ptr<AwaitPromiseCallback> callback) {
   InjectedScript::ObjectScope scope(m_session, promiseObjectId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
   if (!scope.object()->IsPromise()) {
     callback->sendFailure(
-        Response::Error("Could not find promise with given id"));
+        Response::ServerError("Could not find promise with given id"));
     return;
   }
   WrapMode mode = generatePreview.fromMaybe(false) ? WrapMode::kWithPreview
@@ -345,12 +346,12 @@ void V8RuntimeAgentImpl::callFunctionOn(
     Maybe<int> executionContextId, Maybe<String16> objectGroup,
     std::unique_ptr<CallFunctionOnCallback> callback) {
   if (objectId.isJust() && executionContextId.isJust()) {
-    callback->sendFailure(Response::Error(
+    callback->sendFailure(Response::ServerError(
         "ObjectId must not be specified together with executionContextId"));
     return;
   }
   if (!objectId.isJust() && !executionContextId.isJust()) {
-    callback->sendFailure(Response::Error(
+    callback->sendFailure(Response::ServerError(
         "Either ObjectId or executionContextId must be specified"));
     return;
   }
@@ -360,7 +361,7 @@ void V8RuntimeAgentImpl::callFunctionOn(
   if (objectId.isJust()) {
     InjectedScript::ObjectScope scope(m_session, objectId.fromJust());
     Response response = scope.initialize();
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
@@ -376,13 +377,13 @@ void V8RuntimeAgentImpl::callFunctionOn(
     Response response =
         ensureContext(m_inspector, m_session->contextGroupId(),
                       std::move(executionContextId.fromJust()), &contextId);
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
     InjectedScript::ContextScope scope(m_session, contextId);
     response = scope.initialize();
-    if (!response.isSuccess()) {
+    if (!response.IsSuccess()) {
       callback->sendFailure(response);
       return;
     }
@@ -409,13 +410,13 @@ Response V8RuntimeAgentImpl::getProperties(
 
   InjectedScript::ObjectScope scope(m_session, objectId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
 
   scope.ignoreExceptionsAndMuteConsole();
   v8::MicrotasksScope microtasks_scope(m_inspector->isolate(),
                                        v8::MicrotasksScope::kRunMicrotasks);
   if (!scope.object()->IsObject())
-    return Response::Error("Value with given id is not an object");
+    return Response::ServerError("Value with given id is not an object");
 
   v8::Local<v8::Object> object = scope.object().As<v8::Object>();
   response = scope.injectedScript()->getProperties(
@@ -424,9 +425,9 @@ Response V8RuntimeAgentImpl::getProperties(
       generatePreview.fromMaybe(false) ? WrapMode::kWithPreview
                                        : WrapMode::kNoPreview,
       result, exceptionDetails);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (exceptionDetails->isJust() || accessorPropertiesOnly.fromMaybe(false))
-    return Response::OK();
+    return Response::Success();
   std::unique_ptr<protocol::Array<InternalPropertyDescriptor>>
       internalPropertiesProtocolArray;
   std::unique_ptr<protocol::Array<PrivatePropertyDescriptor>>
@@ -434,68 +435,69 @@ Response V8RuntimeAgentImpl::getProperties(
   response = scope.injectedScript()->getInternalAndPrivateProperties(
       object, scope.objectGroupName(), &internalPropertiesProtocolArray,
       &privatePropertiesProtocolArray);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (!internalPropertiesProtocolArray->empty())
     *internalProperties = std::move(internalPropertiesProtocolArray);
   if (!privatePropertiesProtocolArray->empty())
     *privateProperties = std::move(privatePropertiesProtocolArray);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::releaseObject(const String16& objectId) {
   InjectedScript::ObjectScope scope(m_session, objectId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   scope.injectedScript()->releaseObject(objectId);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::releaseObjectGroup(const String16& objectGroup) {
   m_session->releaseObjectGroup(objectGroup);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::runIfWaitingForDebugger() {
   m_inspector->client()->runIfWaitingForDebugger(m_session->contextGroupId());
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::setCustomObjectFormatterEnabled(bool enabled) {
   m_state->setBoolean(V8RuntimeAgentImplState::customObjectFormatterEnabled,
                       enabled);
-  if (!m_enabled) return Response::Error("Runtime agent is not enabled");
+  if (!m_enabled) return Response::ServerError("Runtime agent is not enabled");
   m_session->setCustomObjectFormatterEnabled(enabled);
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::setMaxCallStackSizeToCapture(int size) {
   if (size < 0) {
-    return Response::Error("maxCallStackSizeToCapture should be non-negative");
+    return Response::ServerError(
+        "maxCallStackSizeToCapture should be non-negative");
   }
   V8StackTraceImpl::maxCallStackSizeToCapture = size;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::discardConsoleEntries() {
   V8ConsoleMessageStorage* storage =
       m_inspector->ensureConsoleMessageStorage(m_session->contextGroupId());
   storage->clear();
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::compileScript(
     const String16& expression, const String16& sourceURL, bool persistScript,
     Maybe<int> executionContextId, Maybe<String16>* scriptId,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
-  if (!m_enabled) return Response::Error("Runtime agent is not enabled");
+  if (!m_enabled) return Response::ServerError("Runtime agent is not enabled");
 
   int contextId = 0;
   Response response = ensureContext(m_inspector, m_session->contextGroupId(),
                                     std::move(executionContextId), &contextId);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   InjectedScript::ContextScope scope(m_session, contextId);
   response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
 
   if (!persistScript) m_inspector->debugger()->muteScriptParsedEvents();
   v8::Local<v8::Script> script;
@@ -506,14 +508,14 @@ Response V8RuntimeAgentImpl::compileScript(
     if (scope.tryCatch().HasCaught()) {
       response = scope.injectedScript()->createExceptionDetails(
           scope.tryCatch(), String16(), exceptionDetails);
-      if (!response.isSuccess()) return response;
-      return Response::OK();
+      if (!response.IsSuccess()) return response;
+      return Response::Success();
     } else {
-      return Response::Error("Script compilation failed");
+      return Response::ServerError("Script compilation failed");
     }
   }
 
-  if (!persistScript) return Response::OK();
+  if (!persistScript) return Response::Success();
 
   String16 scriptValueId =
       String16::fromInteger(script->GetUnboundScript()->GetId());
@@ -521,7 +523,7 @@ Response V8RuntimeAgentImpl::compileScript(
       new v8::Global<v8::Script>(m_inspector->isolate(), script));
   m_compiledScripts[scriptValueId] = std::move(global);
   *scriptId = scriptValueId;
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8RuntimeAgentImpl::runScript(
@@ -531,27 +533,28 @@ void V8RuntimeAgentImpl::runScript(
     Maybe<bool> generatePreview, Maybe<bool> awaitPromise,
     std::unique_ptr<RunScriptCallback> callback) {
   if (!m_enabled) {
-    callback->sendFailure(Response::Error("Runtime agent is not enabled"));
+    callback->sendFailure(
+        Response::ServerError("Runtime agent is not enabled"));
     return;
   }
 
   auto it = m_compiledScripts.find(scriptId);
   if (it == m_compiledScripts.end()) {
-    callback->sendFailure(Response::Error("No script with given id"));
+    callback->sendFailure(Response::ServerError("No script with given id"));
     return;
   }
 
   int contextId = 0;
   Response response = ensureContext(m_inspector, m_session->contextGroupId(),
                                     std::move(executionContextId), &contextId);
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
 
   InjectedScript::ContextScope scope(m_session, contextId);
   response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -562,7 +565,7 @@ void V8RuntimeAgentImpl::runScript(
   m_compiledScripts.erase(it);
   v8::Local<v8::Script> script = scriptWrapper->Get(m_inspector->isolate());
   if (script.IsEmpty()) {
-    callback->sendFailure(Response::Error("Script execution failed"));
+    callback->sendFailure(Response::ServerError("Script execution failed"));
     return;
   }
 
@@ -578,7 +581,7 @@ void V8RuntimeAgentImpl::runScript(
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.
   response = scope.initialize();
-  if (!response.isSuccess()) {
+  if (!response.IsSuccess()) {
     callback->sendFailure(response);
     return;
   }
@@ -603,9 +606,9 @@ Response V8RuntimeAgentImpl::queryObjects(
     std::unique_ptr<protocol::Runtime::RemoteObject>* objects) {
   InjectedScript::ObjectScope scope(m_session, prototypeObjectId);
   Response response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
   if (!scope.object()->IsObject()) {
-    return Response::Error("Prototype should be instance of Object");
+    return Response::ServerError("Prototype should be instance of Object");
   }
   v8::Local<v8::Array> resultArray = m_inspector->debugger()->queryObjects(
       scope.context(), v8::Local<v8::Object>::Cast(scope.object()));
@@ -620,11 +623,11 @@ Response V8RuntimeAgentImpl::globalLexicalScopeNames(
   int contextId = 0;
   Response response = ensureContext(m_inspector, m_session->contextGroupId(),
                                     std::move(executionContextId), &contextId);
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
 
   InjectedScript::ContextScope scope(m_session, contextId);
   response = scope.initialize();
-  if (!response.isSuccess()) return response;
+  if (!response.IsSuccess()) return response;
 
   v8::PersistentValueVector<v8::String> names(m_inspector->isolate());
   v8::debug::GlobalLexicalScopeNames(scope.context(), &names);
@@ -633,14 +636,14 @@ Response V8RuntimeAgentImpl::globalLexicalScopeNames(
     (*outNames)->emplace_back(
         toProtocolString(m_inspector->isolate(), names.Get(i)));
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::getIsolateId(String16* outIsolateId) {
   char buf[40];
   std::snprintf(buf, sizeof(buf), "%" PRIx64, m_inspector->isolateId());
   *outIsolateId = buf;
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::getHeapUsage(double* out_usedSize,
@@ -649,7 +652,7 @@ Response V8RuntimeAgentImpl::getHeapUsage(double* out_usedSize,
   m_inspector->isolate()->GetHeapStatistics(&stats);
   *out_usedSize = stats.used_heap_size();
   *out_totalSize = stats.total_heap_size();
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8RuntimeAgentImpl::terminateExecution(
@@ -665,25 +668,25 @@ Response V8RuntimeAgentImpl::addBinding(const String16& name,
   }
   protocol::DictionaryValue* bindings =
       m_state->getObject(V8RuntimeAgentImplState::bindings);
-  if (bindings->booleanProperty(name, false)) return Response::OK();
+  if (bindings->booleanProperty(name, false)) return Response::Success();
   if (executionContextId.isJust()) {
     int contextId = executionContextId.fromJust();
     InspectedContext* context =
         m_inspector->getContext(m_session->contextGroupId(), contextId);
     if (!context) {
-      return Response::Error(
+      return Response::ServerError(
           "Cannot find execution context with given executionContextId");
     }
     addBinding(context, name);
     // false means that we should not add this binding later.
     bindings->setBoolean(name, false);
-    return Response::OK();
+    return Response::Success();
   }
   bindings->setBoolean(name, true);
   m_inspector->forEachContext(
       m_session->contextGroupId(),
       [&name, this](InspectedContext* context) { addBinding(context, name); });
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8RuntimeAgentImpl::bindingCallback(
@@ -730,9 +733,9 @@ void V8RuntimeAgentImpl::addBinding(InspectedContext* context,
 Response V8RuntimeAgentImpl::removeBinding(const String16& name) {
   protocol::DictionaryValue* bindings =
       m_state->getObject(V8RuntimeAgentImplState::bindings);
-  if (!bindings) return Response::OK();
+  if (!bindings) return Response::Success();
   bindings->remove(name);
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8RuntimeAgentImpl::bindingCalled(const String16& name,
@@ -770,7 +773,7 @@ void V8RuntimeAgentImpl::restore() {
 }
 
 Response V8RuntimeAgentImpl::enable() {
-  if (m_enabled) return Response::OK();
+  if (m_enabled) return Response::Success();
   m_inspector->client()->beginEnsureAllContextsInGroup(
       m_session->contextGroupId());
   m_enabled = true;
@@ -782,11 +785,11 @@ Response V8RuntimeAgentImpl::enable() {
   for (const auto& message : storage->messages()) {
     if (!reportMessage(message.get(), false)) break;
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 Response V8RuntimeAgentImpl::disable() {
-  if (!m_enabled) return Response::OK();
+  if (!m_enabled) return Response::Success();
   m_enabled = false;
   m_state->setBoolean(V8RuntimeAgentImplState::runtimeEnabled, false);
   m_state->remove(V8RuntimeAgentImplState::bindings);
@@ -798,7 +801,7 @@ Response V8RuntimeAgentImpl::disable() {
   if (m_session->debuggerAgent() && !m_session->debuggerAgent()->enabled()) {
     m_session->debuggerAgent()->setAsyncCallStackDepth(0);
   }
-  return Response::OK();
+  return Response::Success();
 }
 
 void V8RuntimeAgentImpl::reset() {
@@ -823,9 +826,14 @@ void V8RuntimeAgentImpl::reportExecutionContextCreated(
           .setName(context->humanReadableName())
           .setOrigin(context->origin())
           .build();
-  if (!context->auxData().isEmpty())
+  const String16& aux = context->auxData();
+  if (!aux.isEmpty()) {
+    std::vector<uint8_t> cbor;
+    v8_crdtp::json::ConvertJSONToCBOR(
+        v8_crdtp::span<uint16_t>(aux.characters16(), aux.length()), &cbor);
     description->setAuxData(protocol::DictionaryValue::cast(
-        protocol::StringUtil::parseJSON(context->auxData())));
+        protocol::Value::parseBinary(cbor.data(), cbor.size())));
+  }
   m_frontend.executionContextCreated(std::move(description));
 }
 
diff --git a/deps/v8/src/inspector/v8-schema-agent-impl.cc b/deps/v8/src/inspector/v8-schema-agent-impl.cc
index ae19416d1f..9f2533bd6a 100644
--- a/deps/v8/src/inspector/v8-schema-agent-impl.cc
+++ b/deps/v8/src/inspector/v8-schema-agent-impl.cc
@@ -21,7 +21,7 @@ Response V8SchemaAgentImpl::getDomains(
   *result =
       std::make_unique<std::vector<std::unique_ptr<protocol::Schema::Domain>>>(
           m_session->supportedDomainsImpl());
-  return Response::OK();
+  return Response::Success();
 }
 
 }  // namespace v8_inspector
diff --git a/deps/v8/src/inspector/v8-stack-trace-impl.cc b/deps/v8/src/inspector/v8-stack-trace-impl.cc
index 639ba46592..dc991937c0 100644
--- a/deps/v8/src/inspector/v8-stack-trace-impl.cc
+++ b/deps/v8/src/inspector/v8-stack-trace-impl.cc
@@ -10,6 +10,10 @@
 #include "src/inspector/v8-debugger.h"
 #include "src/inspector/v8-inspector-impl.h"
 
+using v8_crdtp::SpanFrom;
+using v8_crdtp::json::ConvertCBORToJSON;
+using v8_crdtp::json::ConvertJSONToCBOR;
+
 namespace v8_inspector {
 
 int V8StackTraceImpl::maxCallStackSizeToCapture = 200;
@@ -124,10 +128,19 @@ V8StackTraceId::V8StackTraceId(uintptr_t id,
                                bool should_pause)
     : id(id), debugger_id(debugger_id), should_pause(should_pause) {}
 
-V8StackTraceId::V8StackTraceId(const StringView& json)
+V8StackTraceId::V8StackTraceId(StringView json)
     : id(0), debugger_id(V8DebuggerId().pair()) {
-  auto dict =
-      protocol::DictionaryValue::cast(protocol::StringUtil::parseJSON(json));
+  if (json.length() == 0) return;
+  std::vector<uint8_t> cbor;
+  if (json.is8Bit()) {
+    ConvertJSONToCBOR(
+        v8_crdtp::span<uint8_t>(json.characters8(), json.length()), &cbor);
+  } else {
+    ConvertJSONToCBOR(
+        v8_crdtp::span<uint16_t>(json.characters16(), json.length()), &cbor);
+  }
+  auto dict = protocol::DictionaryValue::cast(
+      protocol::Value::parseBinary(cbor.data(), cbor.size()));
   if (!dict) return;
   String16 s;
   if (!dict->getString(kId, &s)) return;
@@ -151,8 +164,8 @@ std::unique_ptr<StringBuffer> V8StackTraceId::ToString() {
   dict->setString(kDebuggerId, V8DebuggerId(debugger_id).toString());
   dict->setBoolean(kShouldPause, should_pause);
   std::vector<uint8_t> json;
-  std::vector<uint8_t> cbor = std::move(*dict).TakeSerialized();
-  v8_crdtp::json::ConvertCBORToJSON(v8_crdtp::SpanFrom(cbor), &json);
+  v8_crdtp::json::ConvertCBORToJSON(v8_crdtp::SpanFrom(dict->Serialize()),
+                                    &json);
   return StringBufferFrom(std::move(json));
 }
 
diff --git a/deps/v8/src/inspector/value-mirror.cc b/deps/v8/src/inspector/value-mirror.cc
index f8d1f74e7d..f9457fd1ec 100644
--- a/deps/v8/src/inspector/value-mirror.cc
+++ b/deps/v8/src/inspector/value-mirror.cc
@@ -42,17 +42,18 @@ V8InternalValueType v8InternalValueTypeFrom(v8::Local<v8::Context> context,
 Response toProtocolValue(v8::Local<v8::Context> context,
                          v8::Local<v8::Value> value, int maxDepth,
                          std::unique_ptr<protocol::Value>* result) {
-  if (!maxDepth) return Response::Error("Object reference chain is too long");
+  if (!maxDepth)
+    return Response::ServerError("Object reference chain is too long");
   maxDepth--;
 
   if (value->IsNull() || value->IsUndefined()) {
     *result = protocol::Value::null();
-    return Response::OK();
+    return Response::Success();
   }
   if (value->IsBoolean()) {
     *result =
         protocol::FundamentalValue::create(value.As<v8::Boolean>()->Value());
-    return Response::OK();
+    return Response::Success();
   }
   if (value->IsNumber()) {
     double doubleValue = value.As<v8::Number>()->Value();
@@ -62,16 +63,16 @@ Response toProtocolValue(v8::Local<v8::Context> context,
       int intValue = static_cast<int>(doubleValue);
       if (intValue == doubleValue) {
         *result = protocol::FundamentalValue::create(intValue);
-        return Response::OK();
+        return Response::Success();
       }
     }
     *result = protocol::FundamentalValue::create(doubleValue);
-    return Response::OK();
+    return Response::Success();
   }
   if (value->IsString()) {
     *result = protocol::StringValue::create(
         toProtocolString(context->GetIsolate(), value.As<v8::String>()));
-    return Response::OK();
+    return Response::Success();
   }
   if (value->IsArray()) {
     v8::Local<v8::Array> array = value.As<v8::Array>();
@@ -84,11 +85,11 @@ Response toProtocolValue(v8::Local<v8::Context> context,
         return Response::InternalError();
       std::unique_ptr<protocol::Value> element;
       Response response = toProtocolValue(context, value, maxDepth, &element);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       inspectorArray->pushValue(std::move(element));
     }
     *result = std::move(inspectorArray);
-    return Response::OK();
+    return Response::Success();
   }
   if (value->IsObject()) {
     std::unique_ptr<protocol::DictionaryValue> jsonObject =
@@ -119,21 +120,21 @@ Response toProtocolValue(v8::Local<v8::Context> context,
       std::unique_ptr<protocol::Value> propertyValue;
       Response response =
           toProtocolValue(context, property, maxDepth, &propertyValue);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       jsonObject->setValue(
           toProtocolString(context->GetIsolate(), propertyName),
           std::move(propertyValue));
     }
     *result = std::move(jsonObject);
-    return Response::OK();
+    return Response::Success();
   }
-  return Response::Error("Object couldn't be returned by value");
+  return Response::ServerError("Object couldn't be returned by value");
 }
 
 Response toProtocolValue(v8::Local<v8::Context> context,
                          v8::Local<v8::Value> value,
                          std::unique_ptr<protocol::Value>* result) {
-  if (value->IsUndefined()) return Response::OK();
+  if (value->IsUndefined()) return Response::Success();
   return toProtocolValue(context, value, 1000, result);
 }
 
@@ -361,7 +362,7 @@ class PrimitiveValueMirror final : public ValueMirror {
                   .build();
     if (m_value->IsNull())
       (*result)->setSubtype(RemoteObject::SubtypeEnum::Null);
-    return Response::OK();
+    return Response::Success();
   }
 
   void buildEntryPreview(
@@ -416,7 +417,7 @@ class NumberMirror final : public ValueMirror {
     } else {
       (*result)->setValue(protocol::FundamentalValue::create(m_value->Value()));
     }
-    return Response::OK();
+    return Response::Success();
   }
   void buildPropertyPreview(
       v8::Local<v8::Context> context, const String16& name,
@@ -470,7 +471,7 @@ class BigIntMirror final : public ValueMirror {
                   .setUnserializableValue(description)
                   .setDescription(description)
                   .build();
-    return Response::OK();
+    return Response::Success();
   }
 
   void buildPropertyPreview(v8::Local<v8::Context> context,
@@ -513,13 +514,13 @@ class SymbolMirror final : public ValueMirror {
       v8::Local<v8::Context> context, WrapMode mode,
       std::unique_ptr<RemoteObject>* result) const override {
     if (mode == WrapMode::kForceValue) {
-      return Response::Error("Object couldn't be returned by value");
+      return Response::ServerError("Object couldn't be returned by value");
     }
     *result = RemoteObject::create()
                   .setType(RemoteObject::TypeEnum::Symbol)
                   .setDescription(descriptionForSymbol(context, m_symbol))
                   .build();
-    return Response::OK();
+    return Response::Success();
   }
 
   void buildPropertyPreview(v8::Local<v8::Context> context,
@@ -576,7 +577,7 @@ class LocationMirror final : public ValueMirror {
                   .setDescription("Object")
                   .setValue(std::move(location))
                   .build();
-    return Response::OK();
+    return Response::Success();
   }
   v8::Local<v8::Value> v8Value() const override { return m_value; }
 
@@ -620,7 +621,7 @@ class FunctionMirror final : public ValueMirror {
     if (mode == WrapMode::kForceValue) {
       std::unique_ptr<protocol::Value> protocolValue;
       Response response = toProtocolValue(context, m_value, &protocolValue);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       *result = RemoteObject::create()
                     .setType(RemoteObject::TypeEnum::Function)
                     .setValue(std::move(protocolValue))
@@ -633,7 +634,7 @@ class FunctionMirror final : public ValueMirror {
                     .setDescription(descriptionForFunction(context, m_value))
                     .build();
     }
-    return Response::OK();
+    return Response::Success();
   }
 
   void buildPropertyPreview(
@@ -881,7 +882,7 @@ class ObjectMirror final : public ValueMirror {
     if (mode == WrapMode::kForceValue) {
       std::unique_ptr<protocol::Value> protocolValue;
       Response response = toProtocolValue(context, m_value, &protocolValue);
-      if (!response.isSuccess()) return response;
+      if (!response.IsSuccess()) return response;
       *result = RemoteObject::create()
                     .setType(RemoteObject::TypeEnum::Object)
                     .setValue(std::move(protocolValue))
@@ -904,7 +905,7 @@ class ObjectMirror final : public ValueMirror {
         (*result)->setPreview(std::move(previewValue));
       }
     }
-    return Response::OK();
+    return Response::Success();
   }
 
   void buildObjectPreview(
diff --git a/deps/v8/src/interpreter/bytecode-array-builder.cc b/deps/v8/src/interpreter/bytecode-array-builder.cc
index 1c61776cdf..cc65545138 100644
--- a/deps/v8/src/interpreter/bytecode-array-builder.cc
+++ b/deps/v8/src/interpreter/bytecode-array-builder.cc
@@ -4,6 +4,7 @@
 
 #include "src/interpreter/bytecode-array-builder.h"
 
+#include "src/common/assert-scope.h"
 #include "src/common/globals.h"
 #include "src/interpreter/bytecode-array-writer.h"
 #include "src/interpreter/bytecode-jump-table.h"
@@ -81,7 +82,9 @@ Register BytecodeArrayBuilder::Local(int index) const {
   return Register(index);
 }
 
-Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(Isolate* isolate) {
+template <typename LocalIsolate>
+Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(
+    LocalIsolate* isolate) {
   DCHECK(RemainderOfBlockIsDead());
   DCHECK(!bytecode_generated_);
   bytecode_generated_ = true;
@@ -99,19 +102,35 @@ Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(Isolate* isolate) {
       isolate, register_count, parameter_count(), handler_table);
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(
+        Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray(
+        OffThreadIsolate* isolate);
+
 #ifdef DEBUG
-int BytecodeArrayBuilder::CheckBytecodeMatches(Handle<BytecodeArray> bytecode) {
+int BytecodeArrayBuilder::CheckBytecodeMatches(BytecodeArray bytecode) {
+  DisallowHeapAllocation no_gc;
   return bytecode_array_writer_.CheckBytecodeMatches(bytecode);
 }
 #endif
 
+template <typename LocalIsolate>
 Handle<ByteArray> BytecodeArrayBuilder::ToSourcePositionTable(
-    Isolate* isolate) {
+    LocalIsolate* isolate) {
   DCHECK(RemainderOfBlockIsDead());
 
   return bytecode_array_writer_.ToSourcePositionTable(isolate);
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> BytecodeArrayBuilder::ToSourcePositionTable(
+        Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> BytecodeArrayBuilder::ToSourcePositionTable(
+        OffThreadIsolate* isolate);
+
 BytecodeSourceInfo BytecodeArrayBuilder::CurrentSourcePosition(
     Bytecode bytecode) {
   BytecodeSourceInfo source_position;
@@ -1237,32 +1256,26 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::JumpIfJSReceiver(
 }
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::JumpLoop(
-    BytecodeLoopHeader* loop_header, int loop_depth) {
-  OutputJumpLoop(loop_header, loop_depth);
-  return *this;
-}
-
-BytecodeArrayBuilder& BytecodeArrayBuilder::SwitchOnSmiNoFeedback(
-    BytecodeJumpTable* jump_table) {
-  OutputSwitchOnSmiNoFeedback(jump_table);
-  return *this;
-}
-
-BytecodeArrayBuilder& BytecodeArrayBuilder::StackCheck(int position) {
+    BytecodeLoopHeader* loop_header, int loop_depth, int position) {
   if (position != kNoSourcePosition) {
-    // We need to attach a non-breakable source position to a stack
-    // check, so we simply add it as expression position. There can be
-    // a prior statement position from constructs like:
+    // We need to attach a non-breakable source position to JumpLoop for its
+    // implicit stack check, so we simply add it as expression position. There
+    // can be a prior statement position from constructs like:
     //
     //    do var x;  while (false);
     //
     // A Nop could be inserted for empty statements, but since no code
-    // is associated with these positions, instead we force the stack
-    // check's expression position which eliminates the empty
-    // statement's position.
+    // is associated with these positions, instead we force the jump loop's
+    // expression position which eliminates the empty statement's position.
     latest_source_info_.ForceExpressionPosition(position);
   }
-  OutputStackCheck();
+  OutputJumpLoop(loop_header, loop_depth);
+  return *this;
+}
+
+BytecodeArrayBuilder& BytecodeArrayBuilder::SwitchOnSmiNoFeedback(
+    BytecodeJumpTable* jump_table) {
+  OutputSwitchOnSmiNoFeedback(jump_table);
   return *this;
 }
 
@@ -1619,6 +1632,14 @@ uint32_t BytecodeArrayBuilder::GetOutputRegisterListOperand(
   return static_cast<uint32_t>(reg_list.first_register().ToOperand());
 }
 
+void BytecodeArrayBuilder::EmitFunctionStartSourcePosition(int position) {
+  bytecode_array_writer_.SetFunctionEntrySourcePosition(position);
+  // Force an expression position to make sure we have one. If the next bytecode
+  // overwrites it, it’s fine since it would mean we have a source position
+  // anyway.
+  latest_source_info_.ForceExpressionPosition(position);
+}
+
 std::ostream& operator<<(std::ostream& os,
                          const BytecodeArrayBuilder::ToBooleanMode& mode) {
   switch (mode) {
diff --git a/deps/v8/src/interpreter/bytecode-array-builder.h b/deps/v8/src/interpreter/bytecode-array-builder.h
index 39cd4fa6f6..cad4f473a2 100644
--- a/deps/v8/src/interpreter/bytecode-array-builder.h
+++ b/deps/v8/src/interpreter/bytecode-array-builder.h
@@ -7,6 +7,7 @@
 
 #include "src/ast/ast.h"
 #include "src/base/compiler-specific.h"
+#include "src/base/export-template.h"
 #include "src/common/globals.h"
 #include "src/interpreter/bytecode-array-writer.h"
 #include "src/interpreter/bytecode-flags.h"
@@ -42,11 +43,15 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
       SourcePositionTableBuilder::RecordingMode source_position_mode =
           SourcePositionTableBuilder::RECORD_SOURCE_POSITIONS);
 
-  Handle<BytecodeArray> ToBytecodeArray(Isolate* isolate);
-  Handle<ByteArray> ToSourcePositionTable(Isolate* isolate);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<BytecodeArray> ToBytecodeArray(LocalIsolate* isolate);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
 
 #ifdef DEBUG
-  int CheckBytecodeMatches(Handle<BytecodeArray> bytecode);
+  int CheckBytecodeMatches(BytecodeArray bytecode);
 #endif
 
   // Get the number of parameters expected by function.
@@ -422,7 +427,7 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
 
   BytecodeArrayBuilder& Jump(BytecodeLabel* label);
   BytecodeArrayBuilder& JumpLoop(BytecodeLoopHeader* loop_header,
-                                 int loop_depth);
+                                 int loop_depth, int position);
 
   BytecodeArrayBuilder& JumpIfTrue(ToBooleanMode mode, BytecodeLabel* label);
   BytecodeArrayBuilder& JumpIfFalse(ToBooleanMode mode, BytecodeLabel* label);
@@ -439,8 +444,6 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
 
   BytecodeArrayBuilder& SwitchOnSmiNoFeedback(BytecodeJumpTable* jump_table);
 
-  BytecodeArrayBuilder& StackCheck(int position);
-
   // Sets the pending message to the value in the accumulator, and returns the
   // previous pending message in the accumulator.
   BytecodeArrayBuilder& SetPendingMessage();
@@ -549,6 +552,8 @@ class V8_EXPORT_PRIVATE BytecodeArrayBuilder final {
   void OutputStarRaw(Register reg);
   void OutputMovRaw(Register src, Register dest);
 
+  void EmitFunctionStartSourcePosition(int position);
+
   // Accessors
   BytecodeRegisterAllocator* register_allocator() {
     return &register_allocator_;
diff --git a/deps/v8/src/interpreter/bytecode-array-writer.cc b/deps/v8/src/interpreter/bytecode-array-writer.cc
index 3a459b4833..a1b9d9d5f6 100644
--- a/deps/v8/src/interpreter/bytecode-array-writer.cc
+++ b/deps/v8/src/interpreter/bytecode-array-writer.cc
@@ -5,6 +5,7 @@
 #include "src/interpreter/bytecode-array-writer.h"
 
 #include "src/api/api-inl.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/interpreter/bytecode-jump-table.h"
 #include "src/interpreter/bytecode-label.h"
 #include "src/interpreter/bytecode-node.h"
@@ -36,8 +37,9 @@ BytecodeArrayWriter::BytecodeArrayWriter(
   bytecodes_.reserve(512);  // Derived via experimentation.
 }
 
+template <typename LocalIsolate>
 Handle<BytecodeArray> BytecodeArrayWriter::ToBytecodeArray(
-    Isolate* isolate, int register_count, int parameter_count,
+    LocalIsolate* isolate, int register_count, int parameter_count,
     Handle<ByteArray> handler_table) {
   DCHECK_EQ(0, unbound_jumps_);
 
@@ -52,27 +54,45 @@ Handle<BytecodeArray> BytecodeArrayWriter::ToBytecodeArray(
   return bytecode_array;
 }
 
-Handle<ByteArray> BytecodeArrayWriter::ToSourcePositionTable(Isolate* isolate) {
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<BytecodeArray> BytecodeArrayWriter::ToBytecodeArray(
+        Isolate* isolate, int register_count, int parameter_count,
+        Handle<ByteArray> handler_table);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<BytecodeArray> BytecodeArrayWriter::ToBytecodeArray(
+        OffThreadIsolate* isolate, int register_count, int parameter_count,
+        Handle<ByteArray> handler_table);
+
+template <typename LocalIsolate>
+Handle<ByteArray> BytecodeArrayWriter::ToSourcePositionTable(
+    LocalIsolate* isolate) {
   DCHECK(!source_position_table_builder_.Lazy());
   Handle<ByteArray> source_position_table =
       source_position_table_builder_.Omit()
-          ? ReadOnlyRoots(isolate).empty_byte_array_handle()
+          ? isolate->factory()->empty_byte_array()
           : source_position_table_builder_.ToSourcePositionTable(isolate);
   return source_position_table;
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> BytecodeArrayWriter::ToSourcePositionTable(
+        Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ByteArray> BytecodeArrayWriter::ToSourcePositionTable(
+        OffThreadIsolate* isolate);
+
 #ifdef DEBUG
-int BytecodeArrayWriter::CheckBytecodeMatches(Handle<BytecodeArray> bytecode) {
+int BytecodeArrayWriter::CheckBytecodeMatches(BytecodeArray bytecode) {
   int mismatches = false;
   int bytecode_size = static_cast<int>(bytecodes()->size());
   const byte* bytecode_ptr = &bytecodes()->front();
-  if (bytecode_size != bytecode->length()) mismatches = true;
+  if (bytecode_size != bytecode.length()) mismatches = true;
 
   // If there's a mismatch only in the length of the bytecode (very unlikely)
   // then the first mismatch will be the first extra bytecode.
-  int first_mismatch = std::min(bytecode_size, bytecode->length());
+  int first_mismatch = std::min(bytecode_size, bytecode.length());
   for (int i = 0; i < first_mismatch; ++i) {
-    if (bytecode_ptr[i] != bytecode->get(i)) {
+    if (bytecode_ptr[i] != bytecode.get(i)) {
       mismatches = true;
       first_mismatch = i;
       break;
@@ -187,6 +207,12 @@ void BytecodeArrayWriter::BindTryRegionEnd(
   handler_table_builder->SetTryRegionEnd(handler_id, current_offset);
 }
 
+void BytecodeArrayWriter::SetFunctionEntrySourcePosition(int position) {
+  bool is_statement = false;
+  source_position_table_builder_.AddPosition(
+      kFunctionEntryBytecodeOffset, SourcePosition(position), is_statement);
+}
+
 void BytecodeArrayWriter::StartBasicBlock() {
   InvalidateLastBytecode();
   exit_seen_in_block_ = false;
diff --git a/deps/v8/src/interpreter/bytecode-array-writer.h b/deps/v8/src/interpreter/bytecode-array-writer.h
index 22f0296aff..c1f4266e49 100644
--- a/deps/v8/src/interpreter/bytecode-array-writer.h
+++ b/deps/v8/src/interpreter/bytecode-array-writer.h
@@ -51,15 +51,21 @@ class V8_EXPORT_PRIVATE BytecodeArrayWriter final {
   void BindTryRegionEnd(HandlerTableBuilder* handler_table_builder,
                         int handler_id);
 
-  Handle<BytecodeArray> ToBytecodeArray(Isolate* isolate, int register_count,
-                                        int parameter_count,
+  void SetFunctionEntrySourcePosition(int position);
+
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<BytecodeArray> ToBytecodeArray(LocalIsolate* isolate,
+                                        int register_count, int parameter_count,
                                         Handle<ByteArray> handler_table);
 
-  Handle<ByteArray> ToSourcePositionTable(Isolate* isolate);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<ByteArray> ToSourcePositionTable(LocalIsolate* isolate);
 
 #ifdef DEBUG
   // Returns -1 if they match or the offset of the first mismatching byte.
-  int CheckBytecodeMatches(Handle<BytecodeArray> bytecode);
+  int CheckBytecodeMatches(BytecodeArray bytecode);
 #endif
 
   bool RemainderOfBlockIsDead() const { return exit_seen_in_block_; }
diff --git a/deps/v8/src/interpreter/bytecode-generator.cc b/deps/v8/src/interpreter/bytecode-generator.cc
index 196f9d8819..18a2fc9913 100644
--- a/deps/v8/src/interpreter/bytecode-generator.cc
+++ b/deps/v8/src/interpreter/bytecode-generator.cc
@@ -17,6 +17,7 @@
 #include "src/interpreter/bytecode-register.h"
 #include "src/interpreter/control-flow-builders.h"
 #include "src/logging/log.h"
+#include "src/logging/off-thread-logger.h"
 #include "src/objects/debug-objects.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/objects-inl.h"
@@ -24,6 +25,7 @@
 #include "src/objects/template-objects-inl.h"
 #include "src/parsing/parse-info.h"
 #include "src/parsing/token.h"
+#include "src/utils/ostreams.h"
 
 namespace v8 {
 namespace internal {
@@ -409,10 +411,7 @@ class BytecodeGenerator::ControlScopeForIteration final
                            LoopBuilder* loop_builder)
       : ControlScope(generator),
         statement_(statement),
-        loop_builder_(loop_builder) {
-    generator->loop_depth_++;
-  }
-  ~ControlScopeForIteration() override { generator()->loop_depth_--; }
+        loop_builder_(loop_builder) {}
 
  protected:
   bool Execute(Command command, Statement* statement,
@@ -724,47 +723,72 @@ class BytecodeGenerator::TestResultScope final : public ExpressionResultScope {
   DISALLOW_COPY_AND_ASSIGN(TestResultScope);
 };
 
-// Used to build a list of global declaration initial value pairs.
-class BytecodeGenerator::GlobalDeclarationsBuilder final : public ZoneObject {
+// Used to build a list of toplevel declaration data.
+class BytecodeGenerator::TopLevelDeclarationsBuilder final : public ZoneObject {
  public:
+  template <typename LocalIsolate>
   Handle<FixedArray> AllocateDeclarations(UnoptimizedCompilationInfo* info,
                                           BytecodeGenerator* generator,
                                           Handle<Script> script,
-                                          Isolate* isolate) {
-    int size = 0;
-    for (Declaration* decl : *info->scope()->declarations()) {
-      Variable* var = decl->var();
-      if (!var->is_used()) continue;
-      if (var->location() != VariableLocation::UNALLOCATED) continue;
-      DCHECK_IMPLIES(decl->node_type() != AstNode::kVariableDeclaration,
-                     decl->node_type() == AstNode::kFunctionDeclaration);
-      size += decl->node_type() == AstNode::kVariableDeclaration ? 1 : 2;
-    }
-
+                                          LocalIsolate* isolate) {
     DCHECK(has_constant_pool_entry_);
 
     Handle<FixedArray> data =
-        isolate->factory()->NewFixedArray(size, AllocationType::kOld);
+        isolate->factory()->NewFixedArray(entry_slots_, AllocationType::kOld);
 
     int array_index = 0;
-    for (Declaration* decl : *info->scope()->declarations()) {
-      Variable* var = decl->var();
-      if (!var->is_used()) continue;
-      if (var->location() != VariableLocation::UNALLOCATED) continue;
-      if (decl->node_type() == AstNode::kVariableDeclaration) {
-        data->set(array_index++, *var->raw_name()->string().get<Factory>());
-      } else {
-        FunctionLiteral* f = static_cast<FunctionDeclaration*>(decl)->fun();
-        Handle<Object> sfi(Compiler::GetSharedFunctionInfo(f, script, isolate));
-        // Return a null handle if any initial values can't be created. Caller
-        // will set stack overflow.
-        if (sfi.is_null()) return Handle<FixedArray>();
-        data->set(array_index++, *sfi);
-        int literal_index = generator->GetCachedCreateClosureSlot(f);
-        data->set(array_index++, Smi::FromInt(literal_index));
+    if (info->scope()->is_module_scope()) {
+      for (Declaration* decl : *info->scope()->declarations()) {
+        Variable* var = decl->var();
+        if (!var->is_used()) continue;
+        if (var->location() != VariableLocation::MODULE) continue;
+#ifdef DEBUG
+        int start = array_index;
+#endif
+        if (decl->IsFunctionDeclaration()) {
+          FunctionLiteral* f = static_cast<FunctionDeclaration*>(decl)->fun();
+          Handle<SharedFunctionInfo> sfi(
+              Compiler::GetSharedFunctionInfo(f, script, isolate));
+          // Return a null handle if any initial values can't be created. Caller
+          // will set stack overflow.
+          if (sfi.is_null()) return Handle<FixedArray>();
+          data->set(array_index++, *sfi);
+          int literal_index = generator->GetCachedCreateClosureSlot(f);
+          data->set(array_index++, Smi::FromInt(literal_index));
+          DCHECK(var->IsExport());
+          data->set(array_index++, Smi::FromInt(var->index()));
+          DCHECK_EQ(start + kModuleFunctionDeclarationSize, array_index);
+        } else if (var->IsExport() && var->binding_needs_init()) {
+          data->set(array_index++, Smi::FromInt(var->index()));
+          DCHECK_EQ(start + kModuleVariableDeclarationSize, array_index);
+        }
+      }
+    } else {
+      for (Declaration* decl : *info->scope()->declarations()) {
+        Variable* var = decl->var();
+        if (!var->is_used()) continue;
+        if (var->location() != VariableLocation::UNALLOCATED) continue;
+#ifdef DEBUG
+        int start = array_index;
+#endif
+        if (decl->IsVariableDeclaration()) {
+          data->set(array_index++, *var->raw_name()->string());
+          DCHECK_EQ(start + kGlobalVariableDeclarationSize, array_index);
+        } else {
+          FunctionLiteral* f = static_cast<FunctionDeclaration*>(decl)->fun();
+          Handle<SharedFunctionInfo> sfi(
+              Compiler::GetSharedFunctionInfo(f, script, isolate));
+          // Return a null handle if any initial values can't be created. Caller
+          // will set stack overflow.
+          if (sfi.is_null()) return Handle<FixedArray>();
+          data->set(array_index++, *sfi);
+          int literal_index = generator->GetCachedCreateClosureSlot(f);
+          data->set(array_index++, Smi::FromInt(literal_index));
+          DCHECK_EQ(start + kGlobalFunctionDeclarationSize, array_index);
+        }
       }
     }
-
+    DCHECK_EQ(array_index, data->length());
     return data;
   }
 
@@ -774,21 +798,37 @@ class BytecodeGenerator::GlobalDeclarationsBuilder final : public ZoneObject {
   }
 
   void set_constant_pool_entry(size_t constant_pool_entry) {
-    DCHECK(has_global_declaration());
+    DCHECK(has_top_level_declaration());
     DCHECK(!has_constant_pool_entry_);
     constant_pool_entry_ = constant_pool_entry;
     has_constant_pool_entry_ = true;
   }
 
-  void record_global_declaration() { has_seen_global_declaration_ = true; }
-  bool has_global_declaration() { return has_seen_global_declaration_; }
+  void record_global_variable_declaration() {
+    entry_slots_ += kGlobalVariableDeclarationSize;
+  }
+  void record_global_function_declaration() {
+    entry_slots_ += kGlobalFunctionDeclarationSize;
+  }
+  void record_module_variable_declaration() {
+    entry_slots_ += kModuleVariableDeclarationSize;
+  }
+  void record_module_function_declaration() {
+    entry_slots_ += kModuleFunctionDeclarationSize;
+  }
+  bool has_top_level_declaration() { return entry_slots_ > 0; }
   bool processed() { return processed_; }
   void mark_processed() { processed_ = true; }
 
  private:
+  const int kGlobalVariableDeclarationSize = 1;
+  const int kGlobalFunctionDeclarationSize = 2;
+  const int kModuleVariableDeclarationSize = 1;
+  const int kModuleFunctionDeclarationSize = 3;
+
   size_t constant_pool_entry_ = 0;
+  int entry_slots_ = 0;
   bool has_constant_pool_entry_ = false;
-  bool has_seen_global_declaration_ = false;
   bool processed_ = false;
 };
 
@@ -910,6 +950,36 @@ class BytecodeGenerator::OptionalChainNullLabelScope final {
   BytecodeLabels* prev_;
 };
 
+// LoopScope delimits the scope of {loop}, from its header to its final jump.
+// It should be constructed iff a (conceptual) back edge should be produced. In
+// the case of creating a LoopBuilder but never emitting the loop, it is valid
+// to skip the creation of LoopScope.
+class BytecodeGenerator::LoopScope final {
+ public:
+  explicit LoopScope(BytecodeGenerator* bytecode_generator, LoopBuilder* loop)
+      : bytecode_generator_(bytecode_generator),
+        parent_loop_scope_(bytecode_generator_->current_loop_scope()),
+        loop_builder_(loop) {
+    loop_builder_->LoopHeader();
+    bytecode_generator_->set_current_loop_scope(this);
+    bytecode_generator_->loop_depth_++;
+  }
+
+  ~LoopScope() {
+    bytecode_generator_->loop_depth_--;
+    bytecode_generator_->set_current_loop_scope(parent_loop_scope_);
+    DCHECK_GE(bytecode_generator_->loop_depth_, 0);
+    loop_builder_->JumpToHeader(
+        bytecode_generator_->loop_depth_,
+        parent_loop_scope_ ? parent_loop_scope_->loop_builder_ : nullptr);
+  }
+
+ private:
+  BytecodeGenerator* const bytecode_generator_;
+  LoopScope* const parent_loop_scope_;
+  LoopBuilder* const loop_builder_;
+};
+
 namespace {
 
 template <typename PropertyT>
@@ -983,7 +1053,7 @@ BytecodeGenerator::BytecodeGenerator(
       current_scope_(info->scope()),
       eager_inner_literals_(eager_inner_literals),
       feedback_slot_cache_(new (zone()) FeedbackSlotCache(zone())),
-      globals_builder_(new (zone()) GlobalDeclarationsBuilder()),
+      top_level_builder_(new (zone()) TopLevelDeclarationsBuilder()),
       block_coverage_builder_(nullptr),
       function_literals_(0, zone()),
       native_function_literals_(0, zone()),
@@ -1000,6 +1070,7 @@ BytecodeGenerator::BytecodeGenerator(
       generator_jump_table_(nullptr),
       suspend_count_(0),
       loop_depth_(0),
+      current_loop_scope_(nullptr),
       catch_prediction_(HandlerTable::UNCAUGHT) {
   DCHECK_EQ(closure_scope(), closure_scope()->GetClosureScope());
   if (info->has_source_range_map()) {
@@ -1008,22 +1079,49 @@ BytecodeGenerator::BytecodeGenerator(
   }
 }
 
+namespace {
+
+template <typename Isolate>
+struct NullContextScopeHelper;
+
+template <>
+struct NullContextScopeHelper<Isolate> {
+  using Type = NullContextScope;
+};
+
+template <>
+struct NullContextScopeHelper<OffThreadIsolate> {
+  class DummyNullContextScope {
+   public:
+    explicit DummyNullContextScope(OffThreadIsolate*) {}
+  };
+  using Type = DummyNullContextScope;
+};
+
+template <typename Isolate>
+using NullContextScopeFor = typename NullContextScopeHelper<Isolate>::Type;
+
+}  // namespace
+
+template <typename LocalIsolate>
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
-    Isolate* isolate, Handle<Script> script) {
+    LocalIsolate* isolate, Handle<Script> script) {
   DCHECK_EQ(ThreadId::Current(), isolate->thread_id());
 #ifdef DEBUG
   // Unoptimized compilation should be context-independent. Verify that we don't
   // access the native context by nulling it out during finalization.
-  NullContextScope null_context_scope(isolate);
+  NullContextScopeFor<LocalIsolate> null_context_scope(isolate);
 #endif
 
   AllocateDeferredConstants(isolate, script);
 
   if (block_coverage_builder_) {
-    info()->set_coverage_info(
-        isolate->factory()->NewCoverageInfo(block_coverage_builder_->slots()));
+    Handle<CoverageInfo> coverage_info =
+        isolate->factory()->NewCoverageInfo(block_coverage_builder_->slots());
+    info()->set_coverage_info(coverage_info);
     if (FLAG_trace_block_coverage) {
-      info()->coverage_info()->Print(info()->literal()->GetDebugName());
+      StdoutStream os;
+      coverage_info->CoverageInfoPrint(os, info()->literal()->GetDebugName());
     }
   }
 
@@ -1038,13 +1136,19 @@ Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
   return bytecode_array;
 }
 
+template Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
+    Isolate* isolate, Handle<Script> script);
+template Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(
+    OffThreadIsolate* isolate, Handle<Script> script);
+
+template <typename LocalIsolate>
 Handle<ByteArray> BytecodeGenerator::FinalizeSourcePositionTable(
-    Isolate* isolate) {
+    LocalIsolate* isolate) {
   DCHECK_EQ(ThreadId::Current(), isolate->thread_id());
 #ifdef DEBUG
   // Unoptimized compilation should be context-independent. Verify that we don't
   // access the native context by nulling it out during finalization.
-  NullContextScope null_context_scope(isolate);
+  NullContextScopeFor<LocalIsolate> null_context_scope(isolate);
 #endif
 
   Handle<ByteArray> source_position_table =
@@ -1058,21 +1162,27 @@ Handle<ByteArray> BytecodeGenerator::FinalizeSourcePositionTable(
   return source_position_table;
 }
 
+template Handle<ByteArray> BytecodeGenerator::FinalizeSourcePositionTable(
+    Isolate* isolate);
+template Handle<ByteArray> BytecodeGenerator::FinalizeSourcePositionTable(
+    OffThreadIsolate* isolate);
+
 #ifdef DEBUG
-int BytecodeGenerator::CheckBytecodeMatches(Handle<BytecodeArray> bytecode) {
+int BytecodeGenerator::CheckBytecodeMatches(BytecodeArray bytecode) {
   return builder()->CheckBytecodeMatches(bytecode);
 }
 #endif
 
-void BytecodeGenerator::AllocateDeferredConstants(Isolate* isolate,
+template <typename LocalIsolate>
+void BytecodeGenerator::AllocateDeferredConstants(LocalIsolate* isolate,
                                                   Handle<Script> script) {
-  if (globals_builder()->has_global_declaration()) {
+  if (top_level_builder()->has_top_level_declaration()) {
     // Build global declaration pair array.
-    Handle<FixedArray> declarations =
-        globals_builder()->AllocateDeclarations(info(), this, script, isolate);
+    Handle<FixedArray> declarations = top_level_builder()->AllocateDeclarations(
+        info(), this, script, isolate);
     if (declarations.is_null()) return SetStackOverflow();
     builder()->SetDeferredConstantPoolEntry(
-        globals_builder()->constant_pool_entry(), declarations);
+        top_level_builder()->constant_pool_entry(), declarations);
   }
 
   // Find or build shared function infos.
@@ -1087,6 +1197,9 @@ void BytecodeGenerator::AllocateDeferredConstants(Isolate* isolate,
   // Find or build shared function infos for the native function templates.
   for (std::pair<NativeFunctionLiteral*, size_t> literal :
        native_function_literals_) {
+    // This should only happen for main-thread compilations.
+    DCHECK((std::is_same<Isolate, v8::internal::Isolate>::value));
+
     NativeFunctionLiteral* expr = literal.first;
     v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
 
@@ -1142,6 +1255,18 @@ void BytecodeGenerator::AllocateDeferredConstants(Isolate* isolate,
   }
 }
 
+template void BytecodeGenerator::AllocateDeferredConstants(
+    Isolate* isolate, Handle<Script> script);
+template void BytecodeGenerator::AllocateDeferredConstants(
+    OffThreadIsolate* isolate, Handle<Script> script);
+
+namespace {
+bool NeedsContextInitialization(DeclarationScope* scope) {
+  return scope->NeedsContext() && !scope->is_script_scope() &&
+         !scope->is_module_scope();
+}
+}  // namespace
+
 void BytecodeGenerator::GenerateBytecode(uintptr_t stack_limit) {
   DisallowHeapAllocation no_allocation;
   DisallowHandleAllocation no_handles;
@@ -1159,14 +1284,14 @@ void BytecodeGenerator::GenerateBytecode(uintptr_t stack_limit) {
 
   AllocateTopLevelRegisters();
 
-  // Perform a stack-check before the body.
-  builder()->StackCheck(info()->literal()->start_position());
+  builder()->EmitFunctionStartSourcePosition(
+      info()->literal()->start_position());
 
   if (info()->literal()->CanSuspend()) {
     BuildGeneratorPrologue();
   }
 
-  if (closure_scope()->NeedsContext() && !closure_scope()->is_script_scope()) {
+  if (NeedsContextInitialization(closure_scope())) {
     // Push a new inner context scope for the function.
     BuildNewLocalActivationContext();
     ContextScope local_function_context(this, closure_scope());
@@ -1223,6 +1348,8 @@ void BytecodeGenerator::GenerateBytecodeBody() {
   // Visit declarations within the function scope.
   if (closure_scope()->is_script_scope()) {
     VisitGlobalDeclarations(closure_scope()->declarations());
+  } else if (closure_scope()->is_module_scope()) {
+    VisitModuleDeclarations(closure_scope()->declarations());
   } else {
     VisitDeclarations(closure_scope()->declarations());
   }
@@ -1232,7 +1359,7 @@ void BytecodeGenerator::GenerateBytecodeBody() {
 
   // The derived constructor case is handled in VisitCallSuper.
   if (IsBaseConstructor(function_kind())) {
-    if (literal->requires_brand_initialization()) {
+    if (literal->class_scope_has_private_brand()) {
       BuildPrivateBrandInitialization(builder()->Receiver());
     }
 
@@ -1320,6 +1447,7 @@ void BytecodeGenerator::VisitVariableDeclaration(VariableDeclaration* decl) {
 
   switch (variable->location()) {
     case VariableLocation::UNALLOCATED:
+    case VariableLocation::MODULE:
       UNREACHABLE();
     case VariableLocation::LOCAL:
       if (variable->binding_needs_init()) {
@@ -1355,13 +1483,6 @@ void BytecodeGenerator::VisitVariableDeclaration(VariableDeclaration* decl) {
           .CallRuntime(Runtime::kDeclareEvalVar, name);
       break;
     }
-    case VariableLocation::MODULE:
-      if (variable->IsExport() && variable->binding_needs_init()) {
-        builder()->LoadTheHole();
-        BuildVariableAssignment(variable, Token::INIT, HoleCheckMode::kElided);
-      }
-      // Nothing to do for imports.
-      break;
   }
 }
 
@@ -1375,6 +1496,7 @@ void BytecodeGenerator::VisitFunctionDeclaration(FunctionDeclaration* decl) {
 
   switch (variable->location()) {
     case VariableLocation::UNALLOCATED:
+    case VariableLocation::MODULE:
       UNREACHABLE();
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL: {
@@ -1400,12 +1522,6 @@ void BytecodeGenerator::VisitFunctionDeclaration(FunctionDeclaration* decl) {
           Runtime::kDeclareEvalFunction, args);
       break;
     }
-    case VariableLocation::MODULE:
-      DCHECK_EQ(variable->mode(), VariableMode::kLet);
-      DCHECK(variable->IsExport());
-      VisitForAccumulatorValue(decl->fun());
-      BuildVariableAssignment(variable, Token::INIT, HoleCheckMode::kElided);
-      break;
   }
   DCHECK_IMPLIES(
       eager_inner_literals_ != nullptr && decl->fun()->ShouldEagerCompile(),
@@ -1430,18 +1546,60 @@ void BytecodeGenerator::VisitModuleNamespaceImports() {
   }
 }
 
+void BytecodeGenerator::BuildDeclareCall(Runtime::FunctionId id) {
+  if (!top_level_builder()->has_top_level_declaration()) return;
+  DCHECK(!top_level_builder()->processed());
+
+  top_level_builder()->set_constant_pool_entry(
+      builder()->AllocateDeferredConstantPoolEntry());
+
+  // Emit code to declare globals.
+  RegisterList args = register_allocator()->NewRegisterList(2);
+  builder()
+      ->LoadConstantPoolEntry(top_level_builder()->constant_pool_entry())
+      .StoreAccumulatorInRegister(args[0])
+      .MoveRegister(Register::function_closure(), args[1])
+      .CallRuntime(id, args);
+
+  top_level_builder()->mark_processed();
+}
+
+void BytecodeGenerator::VisitModuleDeclarations(Declaration::List* decls) {
+  RegisterAllocationScope register_scope(this);
+  for (Declaration* decl : *decls) {
+    Variable* var = decl->var();
+    if (!var->is_used()) continue;
+    if (var->location() == VariableLocation::MODULE) {
+      if (decl->IsFunctionDeclaration()) {
+        DCHECK(var->IsExport());
+        FunctionDeclaration* f = static_cast<FunctionDeclaration*>(decl);
+        AddToEagerLiteralsIfEager(f->fun());
+        top_level_builder()->record_module_function_declaration();
+      } else if (var->IsExport() && var->binding_needs_init()) {
+        DCHECK(decl->IsVariableDeclaration());
+        top_level_builder()->record_module_variable_declaration();
+      }
+    } else {
+      RegisterAllocationScope register_scope(this);
+      Visit(decl);
+    }
+  }
+  BuildDeclareCall(Runtime::kDeclareModuleExports);
+}
+
 void BytecodeGenerator::VisitGlobalDeclarations(Declaration::List* decls) {
   RegisterAllocationScope register_scope(this);
-  bool has_global_declaration = false;
   for (Declaration* decl : *decls) {
     Variable* var = decl->var();
     DCHECK(var->is_used());
     if (var->location() == VariableLocation::UNALLOCATED) {
       // var or function.
-      has_global_declaration = true;
       if (decl->IsFunctionDeclaration()) {
+        top_level_builder()->record_global_function_declaration();
         FunctionDeclaration* f = static_cast<FunctionDeclaration*>(decl);
         AddToEagerLiteralsIfEager(f->fun());
+      } else {
+        top_level_builder()->record_global_variable_declaration();
       }
     } else {
       // let or const. Handled in NewScriptContext.
@@ -1450,22 +1608,7 @@ void BytecodeGenerator::VisitGlobalDeclarations(Declaration::List* decls) {
     }
   }
 
-  if (!has_global_declaration) return;
-  globals_builder()->record_global_declaration();
-  DCHECK(!globals_builder()->processed());
-
-  globals_builder()->set_constant_pool_entry(
-      builder()->AllocateDeferredConstantPoolEntry());
-
-  // Emit code to declare globals.
-  RegisterList args = register_allocator()->NewRegisterList(2);
-  builder()
-      ->LoadConstantPoolEntry(globals_builder()->constant_pool_entry())
-      .StoreAccumulatorInRegister(args[0])
-      .MoveRegister(Register::function_closure(), args[1])
-      .CallRuntime(Runtime::kDeclareGlobals, args);
-
-  globals_builder()->mark_processed();
+  BuildDeclareCall(Runtime::kDeclareGlobals);
 }
 
 void BytecodeGenerator::VisitDeclarations(Declaration::List* declarations) {
@@ -1717,7 +1860,6 @@ void BytecodeGenerator::VisitIterationBody(IterationStatement* stmt,
                                            LoopBuilder* loop_builder) {
   loop_builder->LoopBody();
   ControlScopeForIteration execution_control(this, stmt, loop_builder);
-  builder()->StackCheck(stmt->position());
   Visit(stmt->body());
   loop_builder->BindContinueTarget();
 }
@@ -1725,20 +1867,22 @@ void BytecodeGenerator::VisitIterationBody(IterationStatement* stmt,
 void BytecodeGenerator::VisitDoWhileStatement(DoWhileStatement* stmt) {
   LoopBuilder loop_builder(builder(), block_coverage_builder_, stmt);
   if (stmt->cond()->ToBooleanIsFalse()) {
+    // Since we know that the condition is false, we don't create a loop.
+    // Therefore, we don't create a LoopScope (and thus we don't create a header
+    // and a JumpToHeader). However, we still need to iterate once through the
+    // body.
     VisitIterationBody(stmt, &loop_builder);
   } else if (stmt->cond()->ToBooleanIsTrue()) {
-    loop_builder.LoopHeader();
+    LoopScope loop_scope(this, &loop_builder);
     VisitIterationBody(stmt, &loop_builder);
-    loop_builder.JumpToHeader(loop_depth_);
   } else {
-    loop_builder.LoopHeader();
+    LoopScope loop_scope(this, &loop_builder);
     VisitIterationBody(stmt, &loop_builder);
     builder()->SetExpressionAsStatementPosition(stmt->cond());
     BytecodeLabels loop_backbranch(zone());
     VisitForTest(stmt->cond(), &loop_backbranch, loop_builder.break_labels(),
                  TestFallthrough::kThen);
     loop_backbranch.Bind(builder());
-    loop_builder.JumpToHeader(loop_depth_);
   }
 }
 
@@ -1750,7 +1894,7 @@ void BytecodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
     return;
   }
 
-  loop_builder.LoopHeader();
+  LoopScope loop_scope(this, &loop_builder);
   if (!stmt->cond()->ToBooleanIsTrue()) {
     builder()->SetExpressionAsStatementPosition(stmt->cond());
     BytecodeLabels loop_body(zone());
@@ -1759,22 +1903,21 @@ void BytecodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
     loop_body.Bind(builder());
   }
   VisitIterationBody(stmt, &loop_builder);
-  loop_builder.JumpToHeader(loop_depth_);
 }
 
 void BytecodeGenerator::VisitForStatement(ForStatement* stmt) {
-  LoopBuilder loop_builder(builder(), block_coverage_builder_, stmt);
-
   if (stmt->init() != nullptr) {
     Visit(stmt->init());
   }
+
+  LoopBuilder loop_builder(builder(), block_coverage_builder_, stmt);
   if (stmt->cond() && stmt->cond()->ToBooleanIsFalse()) {
     // If the condition is known to be false there is no need to generate
     // body, next or condition blocks. Init block should be generated.
     return;
   }
 
-  loop_builder.LoopHeader();
+  LoopScope loop_scope(this, &loop_builder);
   if (stmt->cond() && !stmt->cond()->ToBooleanIsTrue()) {
     builder()->SetExpressionAsStatementPosition(stmt->cond());
     BytecodeLabels loop_body(zone());
@@ -1787,7 +1930,6 @@ void BytecodeGenerator::VisitForStatement(ForStatement* stmt) {
     builder()->SetStatementPosition(stmt->next());
     Visit(stmt->next());
   }
-  loop_builder.JumpToHeader(loop_depth_);
 }
 
 void BytecodeGenerator::VisitForInStatement(ForInStatement* stmt) {
@@ -1821,7 +1963,7 @@ void BytecodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // The loop
   {
     LoopBuilder loop_builder(builder(), block_coverage_builder_, stmt);
-    loop_builder.LoopHeader();
+    LoopScope loop_scope(this, &loop_builder);
     builder()->SetExpressionAsStatementPosition(stmt->each());
     builder()->ForInContinue(index, cache_length);
     loop_builder.BreakIfFalse(ToBooleanMode::kAlreadyBoolean);
@@ -1843,7 +1985,6 @@ void BytecodeGenerator::VisitForInStatement(ForInStatement* stmt) {
     VisitIterationBody(stmt, &loop_builder);
     builder()->ForInStep(index);
     builder()->StoreAccumulatorInRegister(index);
-    loop_builder.JumpToHeader(loop_depth_);
   }
   builder()->Bind(&subject_undefined_label);
 }
@@ -1895,7 +2036,7 @@ void BytecodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
         Register next_result = register_allocator()->NewRegister();
 
         LoopBuilder loop_builder(builder(), block_coverage_builder_, stmt);
-        loop_builder.LoopHeader();
+        LoopScope loop_scope(this, &loop_builder);
 
         builder()->LoadTrue().StoreAccumulatorInRegister(done);
 
@@ -1927,8 +2068,6 @@ void BytecodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
         BuildAssignment(lhs_data, Token::ASSIGN, LookupHoistingMode::kNormal);
 
         VisitIterationBody(stmt, &loop_builder);
-
-        loop_builder.JumpToHeader(loop_depth_);
       },
       // Finally block.
       [&](Register iteration_continuation_token) {
@@ -2391,11 +2530,6 @@ void BytecodeGenerator::VisitNativeFunctionLiteral(
   native_function_literals_.push_back(std::make_pair(expr, entry));
 }
 
-void BytecodeGenerator::VisitDoExpression(DoExpression* expr) {
-  VisitBlock(expr->block());
-  VisitVariableProxy(expr->result());
-}
-
 void BytecodeGenerator::VisitConditional(Conditional* expr) {
   ConditionalControlFlowBuilder conditional_builder(
       builder(), block_coverage_builder_, expr);
@@ -2747,7 +2881,7 @@ void BytecodeGenerator::BuildFillArrayWithIterator(
   DCHECK(value.is_valid());
 
   LoopBuilder loop_builder(builder(), nullptr, nullptr);
-  loop_builder.LoopHeader();
+  LoopScope loop_scope(this, &loop_builder);
 
   // Call the iterator's .next() method. Break from the loop if the `done`
   // property is truthy, otherwise load the value from the iterator result and
@@ -2770,7 +2904,6 @@ void BytecodeGenerator::BuildFillArrayWithIterator(
       .UnaryOperation(Token::INC, feedback_index(index_slot))
       .StoreAccumulatorInRegister(index);
   loop_builder.BindContinueTarget();
-  loop_builder.JumpToHeader(loop_depth_);
 }
 
 void BytecodeGenerator::BuildCreateArrayLiteral(
@@ -2932,19 +3065,6 @@ void BytecodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   BuildCreateArrayLiteral(expr->values(), expr);
 }
 
-void BytecodeGenerator::VisitStoreInArrayLiteral(StoreInArrayLiteral* expr) {
-  builder()->SetExpressionAsStatementPosition(expr);
-  RegisterAllocationScope register_scope(this);
-  Register array = register_allocator()->NewRegister();
-  Register index = register_allocator()->NewRegister();
-  VisitForRegisterValue(expr->array(), array);
-  VisitForRegisterValue(expr->index(), index);
-  VisitForAccumulatorValue(expr->value());
-  builder()->StoreInArrayLiteral(
-      array, index,
-      feedback_index(feedback_spec()->AddStoreInArrayLiteralICSlot()));
-}
-
 void BytecodeGenerator::VisitVariableProxy(VariableProxy* proxy) {
   builder()->SetExpressionPosition(proxy);
   BuildVariableLoad(proxy->var(), proxy->hole_check_mode());
@@ -4247,8 +4367,8 @@ void BytecodeGenerator::VisitYieldStar(YieldStar* expr) {
       //   - One for awaiting the iterator result yielded by the delegated
       //     iterator
 
-      LoopBuilder loop(builder(), nullptr, nullptr);
-      loop.LoopHeader();
+      LoopBuilder loop_builder(builder(), nullptr, nullptr);
+      LoopScope loop_scope(this, &loop_builder);
 
       {
         BytecodeLabels after_switch(zone());
@@ -4329,7 +4449,7 @@ void BytecodeGenerator::VisitYieldStar(YieldStar* expr) {
           output, ast_string_constants()->done_string(),
           feedback_index(feedback_spec()->AddLoadICSlot()));
 
-      loop.BreakIfTrue(ToBooleanMode::kConvertToBoolean);
+      loop_builder.BreakIfTrue(ToBooleanMode::kConvertToBoolean);
 
       // Suspend the current generator.
       if (iterator_type == IteratorType::kNormal) {
@@ -4360,8 +4480,7 @@ void BytecodeGenerator::VisitYieldStar(YieldStar* expr) {
                         generator_object())
           .StoreAccumulatorInRegister(resume_mode);
 
-      loop.BindContinueTarget();
-      loop.JumpToHeader(loop_depth_);
+      loop_builder.BindContinueTarget();
     }
   }
 
@@ -4553,16 +4672,37 @@ void BytecodeGenerator::BuildPrivateBrandCheck(Property* property,
   DCHECK(IsPrivateMethodOrAccessorVariableMode(private_name->mode()));
   ClassScope* scope = private_name->scope()->AsClassScope();
   if (private_name->is_static()) {
-    DCHECK_NOT_NULL(scope->class_variable());
     // For static private methods, the only valid receiver is the class.
     // Load the class constructor.
-    BuildVariableLoadForAccumulatorValue(scope->class_variable(),
-                                         HoleCheckMode::kElided);
-    BytecodeLabel return_check;
-    builder()->CompareReference(object).JumpIfTrue(
-        ToBooleanMode::kAlreadyBoolean, &return_check);
-    BuildInvalidPropertyAccess(tmpl, property);
-    builder()->Bind(&return_check);
+    if (scope->class_variable() == nullptr) {
+      // If the static private method has not been used used in source
+      // code (either explicitly or through the presence of eval), but is
+      // accessed by the debugger at runtime, reference to the class variable
+      // is not available since it was not be context-allocated. Therefore we
+      // can't build a branch check, and throw an ReferenceError as if the
+      // method was optimized away.
+      // TODO(joyee): get a reference to the class constructor through
+      // something other than scope->class_variable() in this scenario.
+      RegisterAllocationScope register_scope(this);
+      RegisterList args = register_allocator()->NewRegisterList(2);
+      builder()
+          ->LoadLiteral(Smi::FromEnum(
+              MessageTemplate::
+                  kInvalidUnusedPrivateStaticMethodAccessedByDebugger))
+          .StoreAccumulatorInRegister(args[0])
+          .LoadLiteral(private_name->raw_name())
+          .StoreAccumulatorInRegister(args[1])
+          .CallRuntime(Runtime::kNewError, args)
+          .Throw();
+    } else {
+      BuildVariableLoadForAccumulatorValue(scope->class_variable(),
+                                           HoleCheckMode::kElided);
+      BytecodeLabel return_check;
+      builder()->CompareReference(object).JumpIfTrue(
+          ToBooleanMode::kAlreadyBoolean, &return_check);
+      BuildInvalidPropertyAccess(tmpl, property);
+      builder()->Bind(&return_check);
+    }
   } else {
     BuildVariableLoadForAccumulatorValue(scope->brand(),
                                          HoleCheckMode::kElided);
@@ -4901,7 +5041,7 @@ void BytecodeGenerator::VisitCallSuper(Call* expr) {
   Register instance = register_allocator()->NewRegister();
   builder()->StoreAccumulatorInRegister(instance);
 
-  if (info()->literal()->requires_brand_initialization()) {
+  if (info()->literal()->class_scope_has_private_brand()) {
     BuildPrivateBrandInitialization(instance);
   }
 
@@ -5999,37 +6139,23 @@ void BytecodeGenerator::BuildNewLocalActivationContext() {
   DCHECK_EQ(current_scope(), closure_scope());
 
   // Create the appropriate context.
-  if (scope->is_module_scope()) {
-    // We don't need to do anything for the outer script scope.
-    DCHECK(scope->outer_scope()->is_script_scope());
-
-    // A JSFunction representing a module is called with the module object as
-    // its sole argument.
-    RegisterList args = register_allocator()->NewRegisterList(2);
-    builder()
-        ->MoveRegister(builder()->Parameter(0), args[0])
-        .LoadLiteral(scope)
-        .StoreAccumulatorInRegister(args[1])
-        .CallRuntime(Runtime::kPushModuleContext, args);
-  } else {
-    DCHECK(scope->is_function_scope() || scope->is_eval_scope());
-    int slot_count = scope->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
-    if (slot_count <= ConstructorBuiltins::MaximumFunctionContextSlots()) {
-      switch (scope->scope_type()) {
-        case EVAL_SCOPE:
-          builder()->CreateEvalContext(scope, slot_count);
-          break;
-        case FUNCTION_SCOPE:
-          builder()->CreateFunctionContext(scope, slot_count);
-          break;
-        default:
-          UNREACHABLE();
-      }
-    } else {
-      Register arg = register_allocator()->NewRegister();
-      builder()->LoadLiteral(scope).StoreAccumulatorInRegister(arg).CallRuntime(
-          Runtime::kNewFunctionContext, arg);
+  DCHECK(scope->is_function_scope() || scope->is_eval_scope());
+  int slot_count = scope->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
+  if (slot_count <= ConstructorBuiltins::MaximumFunctionContextSlots()) {
+    switch (scope->scope_type()) {
+      case EVAL_SCOPE:
+        builder()->CreateEvalContext(scope, slot_count);
+        break;
+      case FUNCTION_SCOPE:
+        builder()->CreateFunctionContext(scope, slot_count);
+        break;
+      default:
+        UNREACHABLE();
     }
+  } else {
+    Register arg = register_allocator()->NewRegister();
+    builder()->LoadLiteral(scope).StoreAccumulatorInRegister(arg).CallRuntime(
+        Runtime::kNewFunctionContext, arg);
   }
 }
 
diff --git a/deps/v8/src/interpreter/bytecode-generator.h b/deps/v8/src/interpreter/bytecode-generator.h
index 15b33bcac3..aa461d523c 100644
--- a/deps/v8/src/interpreter/bytecode-generator.h
+++ b/deps/v8/src/interpreter/bytecode-generator.h
@@ -24,7 +24,7 @@ enum class SourceRangeKind;
 
 namespace interpreter {
 
-class GlobalDeclarationsBuilder;
+class TopLevelDeclarationsBuilder;
 class LoopBuilder;
 class BlockCoverageBuilder;
 class BytecodeJumpTable;
@@ -37,12 +37,14 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
       std::vector<FunctionLiteral*>* eager_inner_literals);
 
   void GenerateBytecode(uintptr_t stack_limit);
-  Handle<BytecodeArray> FinalizeBytecode(Isolate* isolate,
+  template <typename LocalIsolate>
+  Handle<BytecodeArray> FinalizeBytecode(LocalIsolate* isolate,
                                          Handle<Script> script);
-  Handle<ByteArray> FinalizeSourcePositionTable(Isolate* isolate);
+  template <typename LocalIsolate>
+  Handle<ByteArray> FinalizeSourcePositionTable(LocalIsolate* isolate);
 
 #ifdef DEBUG
-  int CheckBytecodeMatches(Handle<BytecodeArray> bytecode);
+  int CheckBytecodeMatches(BytecodeArray bytecode);
 #endif
 
 #define DECLARE_VISIT(type) void Visit##type(type* node);
@@ -50,11 +52,13 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 #undef DECLARE_VISIT
 
   // Visiting function for declarations list and statements are overridden.
+  void VisitModuleDeclarations(Declaration::List* declarations);
   void VisitGlobalDeclarations(Declaration::List* declarations);
   void VisitDeclarations(Declaration::List* declarations);
   void VisitStatements(const ZonePtrList<Statement>* statments);
 
  private:
+  class AccumulatorPreservingScope;
   class ContextScope;
   class ControlScope;
   class ControlScopeForBreakable;
@@ -63,17 +67,17 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   class ControlScopeForTryCatch;
   class ControlScopeForTryFinally;
   class CurrentScope;
-  class ExpressionResultScope;
   class EffectResultScope;
+  class ExpressionResultScope;
   class FeedbackSlotCache;
-  class GlobalDeclarationsBuilder;
   class IteratorRecord;
+  class LoopScope;
   class NaryCodeCoverageSlots;
+  class OptionalChainNullLabelScope;
   class RegisterAllocationScope;
-  class AccumulatorPreservingScope;
   class TestResultScope;
+  class TopLevelDeclarationsBuilder;
   class ValueResultScope;
-  class OptionalChainNullLabelScope;
 
   using ToBooleanMode = BytecodeArrayBuilder::ToBooleanMode;
 
@@ -160,7 +164,8 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   };
 
   void GenerateBytecodeBody();
-  void AllocateDeferredConstants(Isolate* isolate, Handle<Script> script);
+  template <typename LocalIsolate>
+  void AllocateDeferredConstants(LocalIsolate* isolate, Handle<Script> script);
 
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
 
@@ -221,6 +226,8 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   void BuildThisVariableLoad();
 
+  void BuildDeclareCall(Runtime::FunctionId id);
+
   Expression* GetDestructuringDefaultValue(Expression** target);
   void BuildDestructuringArrayAssignment(
       ArrayLiteral* pattern, Token::Value op,
@@ -462,9 +469,9 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
     return builder()->register_allocator();
   }
 
-  GlobalDeclarationsBuilder* globals_builder() {
-    DCHECK_NOT_NULL(globals_builder_);
-    return globals_builder_;
+  TopLevelDeclarationsBuilder* top_level_builder() {
+    DCHECK_NOT_NULL(top_level_builder_);
+    return top_level_builder_;
   }
   inline LanguageMode language_mode() const;
   inline FunctionKind function_kind() const;
@@ -482,6 +489,11 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
     catch_prediction_ = value;
   }
 
+  LoopScope* current_loop_scope() const { return current_loop_scope_; }
+  void set_current_loop_scope(LoopScope* loop_scope) {
+    current_loop_scope_ = loop_scope;
+  }
+
   Zone* zone_;
   BytecodeArrayBuilder builder_;
   UnoptimizedCompilationInfo* info_;
@@ -494,7 +506,7 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   FeedbackSlotCache* feedback_slot_cache_;
 
-  GlobalDeclarationsBuilder* globals_builder_;
+  TopLevelDeclarationsBuilder* top_level_builder_;
   BlockCoverageBuilder* block_coverage_builder_;
   ZoneVector<std::pair<FunctionLiteral*, size_t>> function_literals_;
   ZoneVector<std::pair<NativeFunctionLiteral*, size_t>>
@@ -518,8 +530,11 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   BytecodeJumpTable* generator_jump_table_;
   int suspend_count_;
+  // TODO(solanes): assess if we can move loop_depth_ into LoopScope.
   int loop_depth_;
 
+  LoopScope* current_loop_scope_;
+
   HandlerTable::CatchPrediction catch_prediction_;
 };
 
diff --git a/deps/v8/src/interpreter/bytecode-operands.h b/deps/v8/src/interpreter/bytecode-operands.h
index a5d2e6e50a..4f953341d4 100644
--- a/deps/v8/src/interpreter/bytecode-operands.h
+++ b/deps/v8/src/interpreter/bytecode-operands.h
@@ -37,7 +37,7 @@ namespace interpreter {
   V(Flag8, OperandTypeInfo::kFixedUnsignedByte)       \
   V(IntrinsicId, OperandTypeInfo::kFixedUnsignedByte) \
   V(RuntimeId, OperandTypeInfo::kFixedUnsignedShort)  \
-  V(NativeContextIndex, OperandTypeInfo::kScalableUnsignedByte)
+  V(NativeContextIndex, OperandTypeInfo::kFixedUnsignedByte)
 
 // Carefully ordered for operand type range checks below.
 #define NON_REGISTER_OPERAND_TYPE_LIST(V)       \
diff --git a/deps/v8/src/interpreter/bytecode-register-optimizer.cc b/deps/v8/src/interpreter/bytecode-register-optimizer.cc
index d75e45967b..ea6814db81 100644
--- a/deps/v8/src/interpreter/bytecode-register-optimizer.cc
+++ b/deps/v8/src/interpreter/bytecode-register-optimizer.cc
@@ -233,8 +233,13 @@ BytecodeRegisterOptimizer::BytecodeRegisterOptimizer(
   // a vector of register metadata.
   // There is at least one parameter, which is the JS receiver.
   DCHECK_NE(parameter_count, 0);
+#ifdef V8_REVERSE_JSARGS
+  int first_slot_index = parameter_count - 1;
+#else
+  int first_slot_index = 0;
+#endif
   register_info_table_offset_ =
-      -Register::FromParameterIndex(0, parameter_count).index();
+      -Register::FromParameterIndex(first_slot_index, parameter_count).index();
 
   // Initialize register map for parameters, locals, and the
   // accumulator.
diff --git a/deps/v8/src/interpreter/bytecode-register.cc b/deps/v8/src/interpreter/bytecode-register.cc
index 56f6297016..4e56c3b411 100644
--- a/deps/v8/src/interpreter/bytecode-register.cc
+++ b/deps/v8/src/interpreter/bytecode-register.cc
@@ -8,10 +8,17 @@ namespace v8 {
 namespace internal {
 namespace interpreter {
 
+#ifdef V8_REVERSE_JSARGS
+static const int kFirstParamRegisterIndex =
+    (InterpreterFrameConstants::kRegisterFileFromFp -
+     InterpreterFrameConstants::kFirstParamFromFp) /
+    kSystemPointerSize;
+#else
 static const int kLastParamRegisterIndex =
     (InterpreterFrameConstants::kRegisterFileFromFp -
      InterpreterFrameConstants::kLastParamFromFp) /
     kSystemPointerSize;
+#endif
 static const int kFunctionClosureRegisterIndex =
     (InterpreterFrameConstants::kRegisterFileFromFp -
      StandardFrameConstants::kFunctionOffset) /
@@ -36,14 +43,22 @@ static const int kCallerPCOffsetRegisterIndex =
 Register Register::FromParameterIndex(int index, int parameter_count) {
   DCHECK_GE(index, 0);
   DCHECK_LT(index, parameter_count);
+#ifdef V8_REVERSE_JSARGS
+  int register_index = kFirstParamRegisterIndex - index;
+#else
   int register_index = kLastParamRegisterIndex - parameter_count + index + 1;
+#endif
   DCHECK_LT(register_index, 0);
   return Register(register_index);
 }
 
 int Register::ToParameterIndex(int parameter_count) const {
   DCHECK(is_parameter());
+#ifdef V8_REVERSE_JSARGS
+  return kFirstParamRegisterIndex - index();
+#else
   return index() - kLastParamRegisterIndex + parameter_count - 1;
+#endif
 }
 
 Register Register::function_closure() {
diff --git a/deps/v8/src/interpreter/bytecodes.h b/deps/v8/src/interpreter/bytecodes.h
index 80f9e4d311..0b638418d1 100644
--- a/deps/v8/src/interpreter/bytecodes.h
+++ b/deps/v8/src/interpreter/bytecodes.h
@@ -333,9 +333,6 @@ namespace interpreter {
     OperandType::kRegPair, OperandType::kIdx)                                  \
   V(ForInStep, AccumulatorUse::kWrite, OperandType::kReg)                      \
                                                                                \
-  /* Perform a stack guard check */                                            \
-  V(StackCheck, AccumulatorUse::kNone)                                         \
-                                                                               \
   /* Update the pending message */                                             \
   V(SetPendingMessage, AccumulatorUse::kReadWrite)                             \
                                                                                \
@@ -644,10 +641,11 @@ class V8_EXPORT_PRIVATE Bytecodes final : public AllStatic {
   }
 
   // Return true if |bytecode| is a jump without effects,
-  // e.g.  any jump excluding those that include type coercion like
-  // JumpIfTrueToBoolean.
+  // e.g. any jump excluding those that include type coercion like
+  // JumpIfTrueToBoolean, and JumpLoop due to having an implicit StackCheck.
   static constexpr bool IsJumpWithoutEffects(Bytecode bytecode) {
-    return IsJump(bytecode) && !IsJumpIfToBoolean(bytecode);
+    return IsJump(bytecode) && !IsJumpIfToBoolean(bytecode) &&
+           bytecode != Bytecode::kJumpLoop;
   }
 
   // Returns true if the bytecode is a switch.
diff --git a/deps/v8/src/interpreter/constant-array-builder.cc b/deps/v8/src/interpreter/constant-array-builder.cc
index f36556f1d4..feb3abab95 100644
--- a/deps/v8/src/interpreter/constant-array-builder.cc
+++ b/deps/v8/src/interpreter/constant-array-builder.cc
@@ -13,6 +13,7 @@
 #include "src/ast/scopes.h"
 #include "src/base/functional.h"
 #include "src/execution/isolate.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/objects/objects-inl.h"
 
 namespace v8 {
@@ -64,8 +65,9 @@ const ConstantArrayBuilder::Entry& ConstantArrayBuilder::ConstantArraySlice::At(
 }
 
 #if DEBUG
+template <typename LocalIsolate>
 void ConstantArrayBuilder::ConstantArraySlice::CheckAllElementsAreUnique(
-    Isolate* isolate) const {
+    LocalIsolate* isolate) const {
   std::set<Smi> smis;
   std::set<double> heap_numbers;
   std::set<const AstRawString*> strings;
@@ -166,8 +168,9 @@ ConstantArrayBuilder::ConstantArraySlice* ConstantArrayBuilder::IndexToSlice(
   UNREACHABLE();
 }
 
+template <typename LocalIsolate>
 MaybeHandle<Object> ConstantArrayBuilder::At(size_t index,
-                                             Isolate* isolate) const {
+                                             LocalIsolate* isolate) const {
   const ConstantArraySlice* slice = IndexToSlice(index);
   DCHECK_LT(index, slice->capacity());
   if (index < slice->start_index() + slice->size()) {
@@ -177,7 +180,15 @@ MaybeHandle<Object> ConstantArrayBuilder::At(size_t index,
   return MaybeHandle<Object>();
 }
 
-Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(Isolate* isolate) {
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    MaybeHandle<Object> ConstantArrayBuilder::At(size_t index,
+                                                 Isolate* isolate) const;
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    MaybeHandle<Object> ConstantArrayBuilder::At(
+        size_t index, OffThreadIsolate* isolate) const;
+
+template <typename LocalIsolate>
+Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(LocalIsolate* isolate) {
   Handle<FixedArray> fixed_array = isolate->factory()->NewFixedArrayWithHoles(
       static_cast<int>(size()), AllocationType::kOld);
   int array_index = 0;
@@ -207,6 +218,12 @@ Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(Isolate* isolate) {
   return fixed_array;
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(Isolate* isolate);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<FixedArray> ConstantArrayBuilder::ToFixedArray(
+        OffThreadIsolate* isolate);
+
 size_t ConstantArrayBuilder::Insert(Smi smi) {
   auto entry = smi_map_.find(smi);
   if (entry == smi_map_.end()) {
@@ -362,7 +379,9 @@ void ConstantArrayBuilder::DiscardReservedEntry(OperandSize operand_size) {
   OperandSizeToSlice(operand_size)->Unreserve();
 }
 
-Handle<Object> ConstantArrayBuilder::Entry::ToHandle(Isolate* isolate) const {
+template <typename LocalIsolate>
+Handle<Object> ConstantArrayBuilder::Entry::ToHandle(
+    LocalIsolate* isolate) const {
   switch (tag_) {
     case Tag::kDeferred:
       // We shouldn't have any deferred entries by now.
@@ -376,9 +395,10 @@ Handle<Object> ConstantArrayBuilder::Entry::ToHandle(Isolate* isolate) const {
       // TODO(leszeks): There's probably a better value we could use here.
       return isolate->factory()->the_hole_value();
     case Tag::kRawString:
-      return raw_string_->string().get<Factory>();
+      return raw_string_->string();
     case Tag::kHeapNumber:
-      return isolate->factory()->NewNumber<AllocationType::kOld>(heap_number_);
+      return isolate->factory()->template NewNumber<AllocationType::kOld>(
+          heap_number_);
     case Tag::kBigInt:
       // This should never fail: the parser will never create a BigInt
       // literal that cannot be allocated.
@@ -394,6 +414,11 @@ Handle<Object> ConstantArrayBuilder::Entry::ToHandle(Isolate* isolate) const {
   UNREACHABLE();
 }
 
+template Handle<Object> ConstantArrayBuilder::Entry::ToHandle(
+    Isolate* isolate) const;
+template Handle<Object> ConstantArrayBuilder::Entry::ToHandle(
+    OffThreadIsolate* isolate) const;
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/interpreter/constant-array-builder.h b/deps/v8/src/interpreter/constant-array-builder.h
index 968a0cadd5..3376f9a2cc 100644
--- a/deps/v8/src/interpreter/constant-array-builder.h
+++ b/deps/v8/src/interpreter/constant-array-builder.h
@@ -7,6 +7,7 @@
 
 #include "src/ast/ast-value-factory.h"
 #include "src/common/globals.h"
+#include "src/handles/handles.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/objects/smi.h"
 #include "src/utils/identity-map.h"
@@ -52,12 +53,16 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
   explicit ConstantArrayBuilder(Zone* zone);
 
   // Generate a fixed array of constant handles based on inserted objects.
-  Handle<FixedArray> ToFixedArray(Isolate* isolate);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<FixedArray> ToFixedArray(LocalIsolate* isolate);
 
   // Returns the object, as a handle in |isolate|, that is in the constant pool
   // array at index |index|. Returns null if there is no handle at this index.
   // Only expected to be used in tests.
-  MaybeHandle<Object> At(size_t index, Isolate* isolate) const;
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  MaybeHandle<Object> At(size_t index, LocalIsolate* isolate) const;
 
   // Returns the number of elements in the array.
   size_t size() const;
@@ -150,7 +155,8 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
       smi_ = smi;
     }
 
-    Handle<Object> ToHandle(Isolate* isolate) const;
+    template <typename LocalIsolate>
+    Handle<Object> ToHandle(LocalIsolate* isolate) const;
 
    private:
     explicit Entry(Tag tag) : tag_(tag) {}
@@ -199,7 +205,8 @@ class V8_EXPORT_PRIVATE ConstantArrayBuilder final {
     const Entry& At(size_t index) const;
 
 #if DEBUG
-    void CheckAllElementsAreUnique(Isolate* isolate) const;
+    template <typename LocalIsolate>
+    void CheckAllElementsAreUnique(LocalIsolate* isolate) const;
 #endif
 
     inline size_t available() const { return capacity() - reserved() - size(); }
diff --git a/deps/v8/src/interpreter/control-flow-builders.cc b/deps/v8/src/interpreter/control-flow-builders.cc
index 3fa1274f82..7062550d30 100644
--- a/deps/v8/src/interpreter/control-flow-builders.cc
+++ b/deps/v8/src/interpreter/control-flow-builders.cc
@@ -47,6 +47,7 @@ void BreakableControlFlowBuilder::EmitJumpIfNull(BytecodeLabels* sites) {
 
 LoopBuilder::~LoopBuilder() {
   DCHECK(continue_labels_.empty() || continue_labels_.is_bound());
+  DCHECK(end_labels_.empty() || end_labels_.is_bound());
 }
 
 void LoopBuilder::LoopHeader() {
@@ -54,7 +55,8 @@ void LoopBuilder::LoopHeader() {
   // requirements of bytecode basic blocks. The only entry into a loop
   // must be the loop header. Surely breaks is okay? Not if nested
   // and misplaced between the headers.
-  DCHECK(break_labels_.empty() && continue_labels_.empty());
+  DCHECK(break_labels_.empty() && continue_labels_.empty() &&
+         end_labels_.empty());
   builder()->Bind(&loop_header_);
 }
 
@@ -64,17 +66,30 @@ void LoopBuilder::LoopBody() {
   }
 }
 
-void LoopBuilder::JumpToHeader(int loop_depth) {
-  // Pass the proper loop nesting level to the backwards branch, to trigger
-  // on-stack replacement when armed for the given loop nesting depth.
-  int level = Min(loop_depth, AbstractCode::kMaxLoopNestingMarker - 1);
-  // Loop must have closed form, i.e. all loop elements are within the loop,
-  // the loop header precedes the body and next elements in the loop.
-  builder()->JumpLoop(&loop_header_, level);
+void LoopBuilder::JumpToHeader(int loop_depth, LoopBuilder* const parent_loop) {
+  BindLoopEnd();
+  if (parent_loop &&
+      loop_header_.offset() == parent_loop->loop_header_.offset()) {
+    // TurboFan can't cope with multiple loops that have the same loop header
+    // bytecode offset. If we have an inner loop with the same header offset
+    // than its parent loop, we do not create a JumpLoop bytecode. Instead, we
+    // Jump to our parent's JumpToHeader which in turn can be a JumpLoop or, iff
+    // they are a nested inner loop too, a Jump to its parent's JumpToHeader.
+    parent_loop->JumpToLoopEnd();
+  } else {
+    // Pass the proper loop nesting level to the backwards branch, to trigger
+    // on-stack replacement when armed for the given loop nesting depth.
+    int level = Min(loop_depth, AbstractCode::kMaxLoopNestingMarker - 1);
+    // Loop must have closed form, i.e. all loop elements are within the loop,
+    // the loop header precedes the body and next elements in the loop.
+    builder()->JumpLoop(&loop_header_, level, source_position_);
+  }
 }
 
 void LoopBuilder::BindContinueTarget() { continue_labels_.Bind(builder()); }
 
+void LoopBuilder::BindLoopEnd() { end_labels_.Bind(builder()); }
+
 SwitchBuilder::~SwitchBuilder() {
 #ifdef DEBUG
   for (auto site : case_sites_) {
diff --git a/deps/v8/src/interpreter/control-flow-builders.h b/deps/v8/src/interpreter/control-flow-builders.h
index d4f2d11e7c..ac68947e1a 100644
--- a/deps/v8/src/interpreter/control-flow-builders.h
+++ b/deps/v8/src/interpreter/control-flow-builders.h
@@ -9,6 +9,7 @@
 
 #include "src/ast/ast-source-ranges.h"
 #include "src/interpreter/block-coverage-builder.h"
+#include "src/interpreter/bytecode-generator.h"
 #include "src/interpreter/bytecode-label.h"
 #include "src/zone/zone-containers.h"
 
@@ -79,7 +80,6 @@ class V8_EXPORT_PRIVATE BreakableControlFlowBuilder
   BlockCoverageBuilder* block_coverage_builder_;
 };
 
-
 // Class to track control flow for block statements (which can break in JS).
 class V8_EXPORT_PRIVATE BlockBuilder final
     : public BreakableControlFlowBuilder {
@@ -91,7 +91,6 @@ class V8_EXPORT_PRIVATE BlockBuilder final
                                     statement) {}
 };
 
-
 // A class to help with co-ordinating break and continue statements with
 // their loop.
 class V8_EXPORT_PRIVATE LoopBuilder final : public BreakableControlFlowBuilder {
@@ -99,18 +98,20 @@ class V8_EXPORT_PRIVATE LoopBuilder final : public BreakableControlFlowBuilder {
   LoopBuilder(BytecodeArrayBuilder* builder,
               BlockCoverageBuilder* block_coverage_builder, AstNode* node)
       : BreakableControlFlowBuilder(builder, block_coverage_builder, node),
-        continue_labels_(builder->zone()) {
+        continue_labels_(builder->zone()),
+        end_labels_(builder->zone()) {
     if (block_coverage_builder_ != nullptr) {
       block_coverage_body_slot_ =
           block_coverage_builder_->AllocateBlockCoverageSlot(
               node, SourceRangeKind::kBody);
     }
+    source_position_ = node ? node->position() : kNoSourcePosition;
   }
   ~LoopBuilder() override;
 
   void LoopHeader();
   void LoopBody();
-  void JumpToHeader(int loop_depth);
+  void JumpToHeader(int loop_depth, LoopBuilder* const parent_loop);
   void BindContinueTarget();
 
   // This method is called when visiting continue statements in the AST.
@@ -121,15 +122,28 @@ class V8_EXPORT_PRIVATE LoopBuilder final : public BreakableControlFlowBuilder {
   void ContinueIfNull() { EmitJumpIfNull(&continue_labels_); }
 
  private:
+  // Emit a Jump to our parent_loop_'s end label which could be a JumpLoop or,
+  // iff they are a nested inner loop with the same loop header bytecode offset
+  // as their parent's, a Jump to its parent's end label.
+  void JumpToLoopEnd() { EmitJump(&end_labels_); }
+  void BindLoopEnd();
+
   BytecodeLoopHeader loop_header_;
 
   // Unbound labels that identify jumps for continue statements in the code and
   // jumps from checking the loop condition to the header for do-while loops.
   BytecodeLabels continue_labels_;
 
+  // Unbound labels that identify jumps for nested inner loops which share the
+  // same header offset as this loop. Said inner loops will Jump to our end
+  // label, which could be a JumpLoop or, iff we are a nested inner loop too, a
+  // Jump to our parent's end label.
+  BytecodeLabels end_labels_;
+
   int block_coverage_body_slot_;
-};
 
+  int source_position_;
+};
 
 // A class to help with co-ordinating break statements with their switch.
 class V8_EXPORT_PRIVATE SwitchBuilder final
@@ -165,7 +179,6 @@ class V8_EXPORT_PRIVATE SwitchBuilder final
   ZoneVector<BytecodeLabel> case_sites_;
 };
 
-
 // A class to help with co-ordinating control flow in try-catch statements.
 class V8_EXPORT_PRIVATE TryCatchBuilder final : public ControlFlowBuilder {
  public:
@@ -194,7 +207,6 @@ class V8_EXPORT_PRIVATE TryCatchBuilder final : public ControlFlowBuilder {
   TryCatchStatement* statement_;
 };
 
-
 // A class to help with co-ordinating control flow in try-finally statements.
 class V8_EXPORT_PRIVATE TryFinallyBuilder final : public ControlFlowBuilder {
  public:
diff --git a/deps/v8/src/interpreter/handler-table-builder.cc b/deps/v8/src/interpreter/handler-table-builder.cc
index 831d31d09f..91c6e819c1 100644
--- a/deps/v8/src/interpreter/handler-table-builder.cc
+++ b/deps/v8/src/interpreter/handler-table-builder.cc
@@ -15,7 +15,8 @@ namespace interpreter {
 
 HandlerTableBuilder::HandlerTableBuilder(Zone* zone) : entries_(zone) {}
 
-Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(Isolate* isolate) {
+template <typename LocalIsolate>
+Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(LocalIsolate* isolate) {
   int handler_table_size = static_cast<int>(entries_.size());
   Handle<ByteArray> table_byte_array = isolate->factory()->NewByteArray(
       HandlerTable::LengthForRange(handler_table_size), AllocationType::kOld);
@@ -31,6 +32,10 @@ Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(Isolate* isolate) {
   return table_byte_array;
 }
 
+template Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(
+    Isolate* isolate);
+template Handle<ByteArray> HandlerTableBuilder::ToHandlerTable(
+    OffThreadIsolate* isolate);
 
 int HandlerTableBuilder::NewHandlerEntry() {
   int handler_id = static_cast<int>(entries_.size());
diff --git a/deps/v8/src/interpreter/handler-table-builder.h b/deps/v8/src/interpreter/handler-table-builder.h
index 66b8d1f937..9bf2b17258 100644
--- a/deps/v8/src/interpreter/handler-table-builder.h
+++ b/deps/v8/src/interpreter/handler-table-builder.h
@@ -28,7 +28,8 @@ class V8_EXPORT_PRIVATE HandlerTableBuilder final {
 
   // Builds the actual handler table by copying the current values into a heap
   // object. Any further mutations to the builder won't be reflected.
-  Handle<ByteArray> ToHandlerTable(Isolate* isolate);
+  template <typename LocalIsolate>
+  Handle<ByteArray> ToHandlerTable(LocalIsolate* isolate);
 
   // Creates a new handler table entry and returns a {hander_id} identifying the
   // entry, so that it can be referenced by below setter functions.
diff --git a/deps/v8/src/interpreter/interpreter-assembler.cc b/deps/v8/src/interpreter/interpreter-assembler.cc
index 971642344b..eaea1c91dd 100644
--- a/deps/v8/src/interpreter/interpreter-assembler.cc
+++ b/deps/v8/src/interpreter/interpreter-assembler.cc
@@ -122,8 +122,8 @@ void InterpreterAssembler::SaveBytecodeOffset() {
                         IntPtrConstant(payload_offset),
                         TruncateIntPtrToInt32(bytecode_offset));
   } else {
-    StoreNoWriteBarrier(MachineRepresentation::kTaggedSigned, base,
-                        IntPtrConstant(store_offset), SmiTag(bytecode_offset));
+    StoreFullTaggedNoWriteBarrier(base, IntPtrConstant(store_offset),
+                                  SmiTag(bytecode_offset));
   }
 }
 
@@ -265,11 +265,9 @@ TNode<IntPtrT> InterpreterAssembler::LoadAndUntagRegister(Register reg) {
 #if V8_TARGET_LITTLE_ENDIAN
     index += 4;
 #endif
-    return ChangeInt32ToIntPtr(
-        Load(MachineType::Int32(), base, IntPtrConstant(index)));
+    return ChangeInt32ToIntPtr(Load<Int32T>(base, IntPtrConstant(index)));
   } else {
-    return SmiToIntPtr(
-        Load(MachineType::TaggedSigned(), base, IntPtrConstant(index)));
+    return SmiToIntPtr(CAST(LoadFullTagged(base, IntPtrConstant(index))));
   }
 }
 
@@ -625,6 +623,13 @@ TNode<Smi> InterpreterAssembler::BytecodeOperandIdxSmi(int operand_index) {
   return SmiTag(Signed(BytecodeOperandIdx(operand_index)));
 }
 
+TNode<TaggedIndex> InterpreterAssembler::BytecodeOperandIdxTaggedIndex(
+    int operand_index) {
+  TNode<IntPtrT> index =
+      ChangeInt32ToIntPtr(Signed(BytecodeOperandIdxInt32(operand_index)));
+  return IntPtrToTaggedIndex(index);
+}
+
 TNode<UintPtrT> InterpreterAssembler::BytecodeOperandConstantPoolIdx(
     int operand_index, LoadSensitivity needs_poisoning) {
   DCHECK_EQ(OperandType::kIdx,
@@ -766,9 +771,15 @@ void InterpreterAssembler::CallJSAndDispatch(TNode<Object> function,
 
   if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
     // The first argument parameter (the receiver) is implied to be undefined.
+#ifdef V8_REVERSE_JSARGS
+    TailCallStubThenBytecodeDispatch(callable.descriptor(), code_target,
+                                     context, function, arg_count, args...,
+                                     UndefinedConstant());
+#else
     TailCallStubThenBytecodeDispatch(callable.descriptor(), code_target,
                                      context, function, arg_count,
                                      UndefinedConstant(), args...);
+#endif
   } else {
     TailCallStubThenBytecodeDispatch(callable.descriptor(), code_target,
                                      context, function, arg_count, args...);
@@ -1476,7 +1487,8 @@ bool InterpreterAssembler::TargetSupportsUnalignedAccess() {
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
   return false;
 #elif V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_S390 || \
-    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_PPC
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_PPC ||   \
+    V8_TARGET_ARCH_PPC64
   return true;
 #else
 #error "Unknown Architecture"
@@ -1523,9 +1535,14 @@ TNode<FixedArray> InterpreterAssembler::ExportParametersAndRegisterFile(
     // Iterate over parameters and write them into the array.
     Label loop(this, &var_index), done_loop(this);
 
+#ifdef V8_REVERSE_JSARGS
+    TNode<IntPtrT> reg_base =
+        IntPtrConstant(Register::FromParameterIndex(0, 1).ToOperand() + 1);
+#else
     TNode<IntPtrT> reg_base = IntPtrAdd(
         IntPtrConstant(Register::FromParameterIndex(0, 1).ToOperand() - 1),
         formal_parameter_count_intptr);
+#endif
 
     Goto(&loop);
     BIND(&loop);
@@ -1534,7 +1551,11 @@ TNode<FixedArray> InterpreterAssembler::ExportParametersAndRegisterFile(
       GotoIfNot(UintPtrLessThan(index, formal_parameter_count_intptr),
                 &done_loop);
 
+#ifdef V8_REVERSE_JSARGS
+      TNode<IntPtrT> reg_index = IntPtrAdd(reg_base, index);
+#else
       TNode<IntPtrT> reg_index = IntPtrSub(reg_base, index);
+#endif
       TNode<Object> value = LoadRegister(reg_index);
 
       StoreFixedArrayElement(array, index, value);
diff --git a/deps/v8/src/interpreter/interpreter-assembler.h b/deps/v8/src/interpreter/interpreter-assembler.h
index 006b247794..729e23c7a6 100644
--- a/deps/v8/src/interpreter/interpreter-assembler.h
+++ b/deps/v8/src/interpreter/interpreter-assembler.h
@@ -38,6 +38,9 @@ class V8_EXPORT_PRIVATE InterpreterAssembler : public CodeStubAssembler {
   // Returns the smi index immediate for bytecode operand |operand_index|
   // in the current bytecode.
   TNode<Smi> BytecodeOperandIdxSmi(int operand_index);
+  // Returns the TaggedIndex immediate for bytecode operand |operand_index|
+  // in the current bytecode.
+  TNode<TaggedIndex> BytecodeOperandIdxTaggedIndex(int operand_index);
   // Returns the 32-bit unsigned immediate for bytecode operand |operand_index|
   // in the current bytecode.
   TNode<Uint32T> BytecodeOperandUImm(int operand_index);
diff --git a/deps/v8/src/interpreter/interpreter-generator.cc b/deps/v8/src/interpreter/interpreter-generator.cc
index 50ceaf462f..6b8b7135e0 100644
--- a/deps/v8/src/interpreter/interpreter-generator.cc
+++ b/deps/v8/src/interpreter/interpreter-generator.cc
@@ -168,12 +168,8 @@ class InterpreterLoadGlobalAssembler : public InterpreterAssembler {
       Dispatch();
     });
 
-    LazyNode<Smi> lazy_smi_slot = [=] {
-      return SmiTag(Signed(BytecodeOperandIdx(slot_operand_index)));
-    };
-
-    LazyNode<UintPtrT> lazy_slot = [=] {
-      return BytecodeOperandIdx(slot_operand_index);
+    LazyNode<TaggedIndex> lazy_slot = [=] {
+      return BytecodeOperandIdxTaggedIndex(slot_operand_index);
     };
 
     LazyNode<Context> lazy_context = [=] { return GetContext(); };
@@ -184,9 +180,8 @@ class InterpreterLoadGlobalAssembler : public InterpreterAssembler {
       return name;
     };
 
-    accessor_asm.LoadGlobalIC(maybe_feedback_vector, lazy_smi_slot, lazy_slot,
-                              lazy_context, lazy_name, typeof_mode,
-                              &exit_point);
+    accessor_asm.LoadGlobalIC(maybe_feedback_vector, lazy_slot, lazy_context,
+                              lazy_name, typeof_mode, &exit_point);
   }
 };
 
@@ -222,14 +217,13 @@ IGNITION_HANDLER(StaGlobal, InterpreterAssembler) {
   // Store the global via the StoreGlobalIC.
   TNode<Name> name = CAST(LoadConstantPoolEntryAtOperandIndex(0));
   TNode<Object> value = GetAccumulator();
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(1));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<HeapObject> maybe_vector = LoadFeedbackVector();
 
   Label no_feedback(this, Label::kDeferred), end(this);
   GotoIf(IsUndefined(maybe_vector), &no_feedback);
 
-  CallBuiltin(Builtins::kStoreGlobalIC, context, name, value, smi_slot,
+  CallBuiltin(Builtins::kStoreGlobalIC, context, name, value, slot,
               maybe_vector);
   Goto(&end);
 
@@ -514,13 +508,14 @@ IGNITION_HANDLER(StaLookupSlot, InterpreterAssembler) {
 // constant pool entry <name_index>.
 IGNITION_HANDLER(LdaNamedProperty, InterpreterAssembler) {
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
-  TNode<UintPtrT> feedback_slot = BytecodeOperandIdx(2);
 
   // Load receiver.
   TNode<Object> recv = LoadRegisterAtOperandIndex(0);
 
   // Load the name and context lazily.
-  LazyNode<Smi> lazy_smi_slot = [=] { return SmiTag(Signed(feedback_slot)); };
+  LazyNode<TaggedIndex> lazy_slot = [=] {
+    return BytecodeOperandIdxTaggedIndex(2);
+  };
   LazyNode<Name> lazy_name = [=] {
     return CAST(LoadConstantPoolEntryAtOperandIndex(1));
   };
@@ -530,8 +525,8 @@ IGNITION_HANDLER(LdaNamedProperty, InterpreterAssembler) {
   TVARIABLE(Object, var_result);
   ExitPoint exit_point(this, &done, &var_result);
 
-  AccessorAssembler::LazyLoadICParameters params(
-      lazy_context, recv, lazy_name, lazy_smi_slot, feedback_vector);
+  AccessorAssembler::LazyLoadICParameters params(lazy_context, recv, lazy_name,
+                                                 lazy_slot, feedback_vector);
   AccessorAssembler accessor_asm(state());
   accessor_asm.LoadIC_BytecodeHandler(&params, &exit_point);
 
@@ -562,14 +557,13 @@ IGNITION_HANDLER(LdaNamedPropertyNoFeedback, InterpreterAssembler) {
 IGNITION_HANDLER(LdaKeyedProperty, InterpreterAssembler) {
   TNode<Object> object = LoadRegisterAtOperandIndex(0);
   TNode<Object> name = GetAccumulator();
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(1));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   TVARIABLE(Object, var_result);
-  var_result = CallBuiltin(Builtins::kKeyedLoadIC, context, object, name,
-                           smi_slot, feedback_vector);
+  var_result = CallBuiltin(Builtins::kKeyedLoadIC, context, object, name, slot,
+                           feedback_vector);
   SetAccumulator(var_result.value());
   Dispatch();
 }
@@ -586,14 +580,13 @@ class InterpreterStoreNamedPropertyAssembler : public InterpreterAssembler {
     TNode<Object> object = LoadRegisterAtOperandIndex(0);
     TNode<Name> name = CAST(LoadConstantPoolEntryAtOperandIndex(1));
     TNode<Object> value = GetAccumulator();
-    TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(2));
-    TNode<Smi> smi_slot = SmiTag(raw_slot);
+    TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(2);
     TNode<HeapObject> maybe_vector = LoadFeedbackVector();
     TNode<Context> context = GetContext();
 
     TVARIABLE(Object, var_result);
     var_result = CallStub(ic.descriptor(), code_target, context, object, name,
-                          value, smi_slot, maybe_vector);
+                          value, slot, maybe_vector);
     // To avoid special logic in the deoptimizer to re-materialize the value in
     // the accumulator, we overwrite the accumulator after the IC call. It
     // doesn't really matter what we write to the accumulator here, since we
@@ -649,14 +642,13 @@ IGNITION_HANDLER(StaKeyedProperty, InterpreterAssembler) {
   TNode<Object> object = LoadRegisterAtOperandIndex(0);
   TNode<Object> name = LoadRegisterAtOperandIndex(1);
   TNode<Object> value = GetAccumulator();
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(2));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(2);
   TNode<HeapObject> maybe_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   TVARIABLE(Object, var_result);
   var_result = CallBuiltin(Builtins::kKeyedStoreIC, context, object, name,
-                           value, smi_slot, maybe_vector);
+                           value, slot, maybe_vector);
   // To avoid special logic in the deoptimizer to re-materialize the value in
   // the accumulator, we overwrite the accumulator after the IC call. It
   // doesn't really matter what we write to the accumulator here, since we
@@ -674,14 +666,13 @@ IGNITION_HANDLER(StaInArrayLiteral, InterpreterAssembler) {
   TNode<Object> array = LoadRegisterAtOperandIndex(0);
   TNode<Object> index = LoadRegisterAtOperandIndex(1);
   TNode<Object> value = GetAccumulator();
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(2));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(2);
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   TVARIABLE(Object, var_result);
   var_result = CallBuiltin(Builtins::kStoreInArrayLiteralIC, context, array,
-                           index, value, smi_slot, feedback_vector);
+                           index, value, slot, feedback_vector);
   // To avoid special logic in the deoptimizer to re-materialize the value in
   // the accumulator, we overwrite the accumulator after the IC call. It
   // doesn't really matter what we write to the accumulator here, since we
@@ -705,13 +696,13 @@ IGNITION_HANDLER(StaDataPropertyInLiteral, InterpreterAssembler) {
   TNode<Object> value = GetAccumulator();
   TNode<Smi> flags =
       SmiFromInt32(UncheckedCast<Int32T>(BytecodeOperandFlag(2)));
-  TNode<Smi> vector_index = BytecodeOperandIdxSmi(3);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(3);
 
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   CallRuntime(Runtime::kDefineDataPropertyInLiteral, context, object, name,
-              value, flags, feedback_vector, vector_index);
+              value, flags, feedback_vector, slot);
   Dispatch();
 }
 
@@ -1586,17 +1577,32 @@ class InterpreterJSCallAssembler : public InterpreterAssembler {
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex));
         break;
       case 2:
+#ifdef V8_REVERSE_JSARGS
+        CallJSAndDispatch(
+            function, context, Int32Constant(arg_count), receiver_mode,
+            LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 1),
+            LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex));
+#else
         CallJSAndDispatch(
             function, context, Int32Constant(arg_count), receiver_mode,
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex),
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 1));
+#endif
         break;
       case 3:
+#ifdef V8_REVERSE_JSARGS
+        CallJSAndDispatch(
+            function, context, Int32Constant(arg_count), receiver_mode,
+            LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 2),
+            LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 1),
+            LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex));
+#else
         CallJSAndDispatch(
             function, context, Int32Constant(arg_count), receiver_mode,
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex),
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 1),
             LoadRegisterAtOperandIndex(kFirstArgumentOperandIndex + 2));
+#endif
         break;
       default:
         UNREACHABLE();
@@ -1874,14 +1880,13 @@ IGNITION_HANDLER(TestReferenceEqual, InterpreterAssembler) {
 IGNITION_HANDLER(TestIn, InterpreterAssembler) {
   TNode<Object> name = LoadRegisterAtOperandIndex(0);
   TNode<Object> object = GetAccumulator();
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(1));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   TVARIABLE(Object, var_result);
-  var_result = CallBuiltin(Builtins::kKeyedHasIC, context, object, name,
-                           smi_slot, feedback_vector);
+  var_result = CallBuiltin(Builtins::kKeyedHasIC, context, object, name, slot,
+                           feedback_vector);
   SetAccumulator(var_result.value());
   Dispatch();
 }
@@ -1902,7 +1907,8 @@ IGNITION_HANDLER(TestInstanceOf, InterpreterAssembler) {
 
   // Record feedback for the {callable} in the {feedback_vector}.
   CollectCallableFeedback(callable, context, CAST(maybe_feedback_vector),
-                          slot_id);
+                          slot_id,
+                          CallableFeedbackMode::kDontCollectFeedbackCell);
   Goto(&feedback_done);
 
   BIND(&feedback_done);
@@ -2361,12 +2367,15 @@ IGNITION_HANDLER(JumpIfJSReceiverConstant, InterpreterAssembler) {
 // JumpLoop <imm> <loop_depth>
 //
 // Jump by the number of bytes represented by the immediate operand |imm|. Also
-// performs a loop nesting check and potentially triggers OSR in case the
-// current OSR level matches (or exceeds) the specified |loop_depth|.
+// performs a loop nesting check, a stack check, and potentially triggers OSR in
+// case the current OSR level matches (or exceeds) the specified |loop_depth|.
 IGNITION_HANDLER(JumpLoop, InterpreterAssembler) {
   TNode<IntPtrT> relative_jump = Signed(BytecodeOperandUImmWord(0));
   TNode<Int32T> loop_depth = BytecodeOperandImm(1);
   TNode<Int8T> osr_level = LoadOsrNestingLevel();
+  TNode<Context> context = GetContext();
+
+  PerformStackCheck(context);
 
   // Check if OSR points at the given {loop_depth} are armed by comparing it to
   // the current {osr_level} loaded from the header of the BytecodeArray.
@@ -2381,7 +2390,6 @@ IGNITION_HANDLER(JumpLoop, InterpreterAssembler) {
   {
     Callable callable = CodeFactory::InterpreterOnStackReplacement(isolate());
     TNode<Code> target = HeapConstant(callable.code());
-    TNode<Context> context = GetContext();
     CallStub(callable.descriptor(), target, context);
     JumpBackward(relative_jump);
   }
@@ -2425,7 +2433,7 @@ IGNITION_HANDLER(SwitchOnSmiNoFeedback, InterpreterAssembler) {
 IGNITION_HANDLER(CreateRegExpLiteral, InterpreterAssembler) {
   TNode<Object> pattern = LoadConstantPoolEntryAtOperandIndex(0);
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
-  TNode<UintPtrT> slot_id = BytecodeOperandIdx(1);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<Smi> flags =
       SmiFromInt32(UncheckedCast<Int32T>(BytecodeOperandFlag(2)));
   TNode<Context> context = GetContext();
@@ -2434,7 +2442,7 @@ IGNITION_HANDLER(CreateRegExpLiteral, InterpreterAssembler) {
 
   ConstructorBuiltinsAssembler constructor_assembler(state());
   result = constructor_assembler.EmitCreateRegExpLiteral(
-      feedback_vector, slot_id, pattern, flags, context);
+      feedback_vector, slot, pattern, flags, context);
   SetAccumulator(result.value());
   Dispatch();
 }
@@ -2445,7 +2453,7 @@ IGNITION_HANDLER(CreateRegExpLiteral, InterpreterAssembler) {
 // CreateArrayLiteral flags <flags> and constant elements in <element_idx>.
 IGNITION_HANDLER(CreateArrayLiteral, InterpreterAssembler) {
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
-  TNode<UintPtrT> slot_id = BytecodeOperandIdx(1);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<Context> context = GetContext();
   TNode<Uint32T> bytecode_flags = BytecodeOperandFlag(2);
 
@@ -2461,7 +2469,7 @@ IGNITION_HANDLER(CreateArrayLiteral, InterpreterAssembler) {
   {
     ConstructorBuiltinsAssembler constructor_assembler(state());
     TNode<JSArray> result = constructor_assembler.EmitCreateShallowArrayLiteral(
-        CAST(feedback_vector), slot_id, context, &call_runtime,
+        CAST(feedback_vector), slot, context, &call_runtime,
         TRACK_ALLOCATION_SITE);
     SetAccumulator(result);
     Dispatch();
@@ -2476,7 +2484,7 @@ IGNITION_HANDLER(CreateArrayLiteral, InterpreterAssembler) {
     TNode<Object> constant_elements = LoadConstantPoolEntryAtOperandIndex(0);
     TNode<Object> result =
         CallRuntime(Runtime::kCreateArrayLiteral, context, feedback_vector,
-                    SmiTag(Signed(slot_id)), constant_elements, flags);
+                    slot, constant_elements, flags);
     SetAccumulator(result);
     Dispatch();
   }
@@ -2487,7 +2495,7 @@ IGNITION_HANDLER(CreateArrayLiteral, InterpreterAssembler) {
 // Creates an empty JSArray literal for literal index <literal_idx>.
 IGNITION_HANDLER(CreateEmptyArrayLiteral, InterpreterAssembler) {
   TNode<HeapObject> maybe_feedback_vector = LoadFeedbackVector();
-  TNode<UintPtrT> slot_id = BytecodeOperandIdx(0);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(0);
   TNode<Context> context = GetContext();
 
   Label no_feedback(this, Label::kDeferred), end(this);
@@ -2496,7 +2504,7 @@ IGNITION_HANDLER(CreateEmptyArrayLiteral, InterpreterAssembler) {
 
   ConstructorBuiltinsAssembler constructor_assembler(state());
   result = constructor_assembler.EmitCreateEmptyArrayLiteral(
-      CAST(maybe_feedback_vector), slot_id, context);
+      CAST(maybe_feedback_vector), slot, context);
   Goto(&end);
 
   BIND(&no_feedback);
@@ -2534,7 +2542,7 @@ IGNITION_HANDLER(CreateArrayFromIterable, InterpreterAssembler) {
 // CreateObjectLiteralFlags <flags> and constant elements in <element_idx>.
 IGNITION_HANDLER(CreateObjectLiteral, InterpreterAssembler) {
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
-  TNode<UintPtrT> slot_id = BytecodeOperandIdx(1);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(1);
   TNode<Uint32T> bytecode_flags = BytecodeOperandFlag(2);
 
   Label if_fast_clone(this), if_not_fast_clone(this, Label::kDeferred);
@@ -2552,7 +2560,7 @@ IGNITION_HANDLER(CreateObjectLiteral, InterpreterAssembler) {
     ConstructorBuiltinsAssembler constructor_assembler(state());
     TNode<HeapObject> result =
         constructor_assembler.EmitCreateShallowObjectLiteral(
-            CAST(feedback_vector), slot_id, &if_not_fast_clone);
+            CAST(feedback_vector), slot, &if_not_fast_clone);
     SetAccumulator(result);
     Dispatch();
   }
@@ -2569,9 +2577,9 @@ IGNITION_HANDLER(CreateObjectLiteral, InterpreterAssembler) {
             bytecode_flags);
     TNode<Smi> flags = SmiTag(Signed(flags_raw));
 
-    TNode<Object> result = CallRuntime(Runtime::kCreateObjectLiteral, context,
-                                       feedback_vector, SmiTag(Signed(slot_id)),
-                                       object_boilerplate_description, flags);
+    TNode<Object> result =
+        CallRuntime(Runtime::kCreateObjectLiteral, context, feedback_vector,
+                    slot, object_boilerplate_description, flags);
     SetAccumulator(result);
     // TODO(klaasb) build a single dispatch once the call is inlined
     Dispatch();
@@ -2600,14 +2608,13 @@ IGNITION_HANDLER(CloneObject, InterpreterAssembler) {
   TNode<UintPtrT> raw_flags =
       DecodeWordFromWord32<CreateObjectLiteralFlags::FlagsBits>(bytecode_flags);
   TNode<Smi> smi_flags = SmiTag(Signed(raw_flags));
-  TNode<IntPtrT> raw_slot = Signed(BytecodeOperandIdx(2));
-  TNode<Smi> smi_slot = SmiTag(raw_slot);
+  TNode<TaggedIndex> slot = BytecodeOperandIdxTaggedIndex(2);
   TNode<HeapObject> maybe_feedback_vector = LoadFeedbackVector();
   TNode<Context> context = GetContext();
 
   TVARIABLE(Object, var_result);
   var_result = CallBuiltin(Builtins::kCloneObjectIC, context, source, smi_flags,
-                           smi_slot, maybe_feedback_vector);
+                           slot, maybe_feedback_vector);
   SetAccumulator(var_result.value());
   Dispatch();
 }
@@ -2836,15 +2843,6 @@ IGNITION_HANDLER(CreateRestParameter, InterpreterAssembler) {
   Dispatch();
 }
 
-// StackCheck
-//
-// Performs a stack guard check.
-IGNITION_HANDLER(StackCheck, InterpreterAssembler) {
-  TNode<Context> context = GetContext();
-  PerformStackCheck(context);
-  Dispatch();
-}
-
 // SetPendingMessage
 //
 // Sets the pending message to the value in the accumulator, and returns the
@@ -2852,7 +2850,8 @@ IGNITION_HANDLER(StackCheck, InterpreterAssembler) {
 IGNITION_HANDLER(SetPendingMessage, InterpreterAssembler) {
   TNode<ExternalReference> pending_message = ExternalConstant(
       ExternalReference::address_of_pending_message_obj(isolate()));
-  TNode<HeapObject> previous_message = Load<HeapObject>(pending_message);
+  TNode<HeapObject> previous_message =
+      UncheckedCast<HeapObject>(LoadFullTagged(pending_message));
   TNode<Object> new_message = GetAccumulator();
   StoreFullTaggedNoWriteBarrier(pending_message, new_message);
   SetAccumulator(previous_message);
@@ -3009,7 +3008,7 @@ IGNITION_HANDLER(IncBlockCounter, InterpreterAssembler) {
 // map of the |receiver| if it has a usable enum cache or a fixed array
 // with the keys to enumerate in the accumulator.
 IGNITION_HANDLER(ForInEnumerate, InterpreterAssembler) {
-  TNode<HeapObject> receiver = CAST(LoadRegisterAtOperandIndex(0));
+  TNode<JSReceiver> receiver = CAST(LoadRegisterAtOperandIndex(0));
   TNode<Context> context = GetContext();
 
   Label if_empty(this), if_runtime(this, Label::kDeferred);
@@ -3188,14 +3187,12 @@ IGNITION_HANDLER(GetIterator, InterpreterAssembler) {
   TNode<Object> receiver = LoadRegisterAtOperandIndex(0);
   TNode<Context> context = GetContext();
   TNode<HeapObject> feedback_vector = LoadFeedbackVector();
-  TNode<IntPtrT> load_feedback_slot = Signed(BytecodeOperandIdx(1));
-  TNode<IntPtrT> call_feedback_slot = Signed(BytecodeOperandIdx(2));
-  TNode<Smi> load_slot_smi = SmiTag(load_feedback_slot);
-  TNode<Smi> call_slot_smi = SmiTag(call_feedback_slot);
+  TNode<TaggedIndex> load_slot = BytecodeOperandIdxTaggedIndex(1);
+  TNode<TaggedIndex> call_slot = BytecodeOperandIdxTaggedIndex(2);
 
   TNode<Object> iterator =
       CallBuiltin(Builtins::kGetIteratorWithFeedback, context, receiver,
-                  load_slot_smi, call_slot_smi, feedback_vector);
+                  load_slot, call_slot, feedback_vector);
   SetAccumulator(iterator);
   Dispatch();
 }
diff --git a/deps/v8/src/interpreter/interpreter.cc b/deps/v8/src/interpreter/interpreter.cc
index a7afb8263e..54f4a3caa3 100644
--- a/deps/v8/src/interpreter/interpreter.cc
+++ b/deps/v8/src/interpreter/interpreter.cc
@@ -12,6 +12,7 @@
 #include "src/ast/scopes.h"
 #include "src/codegen/compiler.h"
 #include "src/codegen/unoptimized-compilation-info.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/init/bootstrapper.h"
 #include "src/init/setup-isolate.h"
 #include "src/interpreter/bytecode-generator.h"
@@ -40,12 +41,20 @@ class InterpreterCompilationJob final : public UnoptimizedCompilationJob {
   Status ExecuteJobImpl() final;
   Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
                          Isolate* isolate) final;
+  Status FinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
+                         OffThreadIsolate* isolate) final;
 
  private:
   BytecodeGenerator* generator() { return &generator_; }
-  void CheckAndPrintBytecodeMismatch(Isolate* isolate, Handle<Script> script,
+  template <typename LocalIsolate>
+  void CheckAndPrintBytecodeMismatch(LocalIsolate* isolate,
+                                     Handle<Script> script,
                                      Handle<BytecodeArray> bytecode);
 
+  template <typename LocalIsolate>
+  Status DoFinalizeJobImpl(Handle<SharedFunctionInfo> shared_info,
+                           LocalIsolate* isolate);
+
   Zone zone_;
   UnoptimizedCompilationInfo compilation_info_;
   BytecodeGenerator generator_;
@@ -104,10 +113,6 @@ size_t Interpreter::GetDispatchTableIndex(Bytecode bytecode,
                      kEntriesPerOperandScale;
 }
 
-int Interpreter::InterruptBudget() {
-  return FLAG_interrupt_budget;
-}
-
 namespace {
 
 void MaybePrintAst(ParseInfo* parse_info,
@@ -171,11 +176,13 @@ InterpreterCompilationJob::Status InterpreterCompilationJob::ExecuteJobImpl() {
 }
 
 #ifdef DEBUG
+template <typename LocalIsolate>
 void InterpreterCompilationJob::CheckAndPrintBytecodeMismatch(
-    Isolate* isolate, Handle<Script> script, Handle<BytecodeArray> bytecode) {
-  int first_mismatch = generator()->CheckBytecodeMatches(bytecode);
+    LocalIsolate* isolate, Handle<Script> script,
+    Handle<BytecodeArray> bytecode) {
+  int first_mismatch = generator()->CheckBytecodeMatches(*bytecode);
   if (first_mismatch >= 0) {
-    parse_info()->ast_value_factory()->Internalize(isolate->factory());
+    parse_info()->ast_value_factory()->Internalize(isolate);
     DeclarationScope::AllocateScopeInfos(parse_info(), isolate);
 
     Handle<BytecodeArray> new_bytecode =
@@ -184,8 +191,7 @@ void InterpreterCompilationJob::CheckAndPrintBytecodeMismatch(
     std::cerr << "Bytecode mismatch";
 #ifdef OBJECT_PRINT
     std::cerr << " found for function: ";
-    Handle<String> name =
-        parse_info()->function_name()->string().get<Factory>();
+    Handle<String> name = parse_info()->function_name()->string();
     if (name->length() == 0) {
       std::cerr << "anonymous";
     } else {
@@ -214,7 +220,22 @@ InterpreterCompilationJob::Status InterpreterCompilationJob::FinalizeJobImpl(
       RuntimeCallCounterId::kCompileIgnitionFinalization);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
                "V8.CompileIgnitionFinalization");
+  return DoFinalizeJobImpl(shared_info, isolate);
+}
+
+InterpreterCompilationJob::Status InterpreterCompilationJob::FinalizeJobImpl(
+    Handle<SharedFunctionInfo> shared_info, OffThreadIsolate* isolate) {
+  RuntimeCallTimerScope runtimeTimerScope(
+      parse_info()->runtime_call_stats(),
+      RuntimeCallCounterId::kCompileBackgroundIgnitionFinalization);
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+               "V8.CompileIgnitionFinalization");
+  return DoFinalizeJobImpl(shared_info, isolate);
+}
 
+template <typename LocalIsolate>
+InterpreterCompilationJob::Status InterpreterCompilationJob::DoFinalizeJobImpl(
+    Handle<SharedFunctionInfo> shared_info, LocalIsolate* isolate) {
   Handle<BytecodeArray> bytecodes = compilation_info_.bytecode_array();
   if (bytecodes.is_null()) {
     bytecodes = generator()->FinalizeBytecode(
@@ -265,7 +286,7 @@ Interpreter::NewSourcePositionCollectionJob(
   auto job = std::make_unique<InterpreterCompilationJob>(parse_info, literal,
                                                          allocator, nullptr);
   job->compilation_info()->SetBytecodeArray(existing_bytecode);
-  return std::unique_ptr<UnoptimizedCompilationJob> { static_cast<UnoptimizedCompilationJob*>(job.release()) };
+  return job;
 }
 
 void Interpreter::ForEachBytecode(
@@ -361,9 +382,7 @@ Local<v8::Object> Interpreter::GetDispatchCountersObject() {
       if (counter > 0) {
         std::string to_name = Bytecodes::ToString(to_bytecode);
         Local<v8::String> to_name_object =
-            v8::String::NewFromUtf8(isolate, to_name.c_str(),
-                                    NewStringType::kNormal)
-                .ToLocalChecked();
+            v8::String::NewFromUtf8(isolate, to_name.c_str()).ToLocalChecked();
         Local<v8::Number> counter_object = v8::Number::New(isolate, counter);
         CHECK(counters_row
                   ->DefineOwnProperty(context, to_name_object, counter_object)
@@ -373,9 +392,7 @@ Local<v8::Object> Interpreter::GetDispatchCountersObject() {
 
     std::string from_name = Bytecodes::ToString(from_bytecode);
     Local<v8::String> from_name_object =
-        v8::String::NewFromUtf8(isolate, from_name.c_str(),
-                                NewStringType::kNormal)
-            .ToLocalChecked();
+        v8::String::NewFromUtf8(isolate, from_name.c_str()).ToLocalChecked();
 
     CHECK(
         counters_map->DefineOwnProperty(context, from_name_object, counters_row)
diff --git a/deps/v8/src/interpreter/interpreter.h b/deps/v8/src/interpreter/interpreter.h
index d85b872639..3ef28fdfbf 100644
--- a/deps/v8/src/interpreter/interpreter.h
+++ b/deps/v8/src/interpreter/interpreter.h
@@ -38,9 +38,6 @@ class Interpreter {
   explicit Interpreter(Isolate* isolate);
   virtual ~Interpreter() = default;
 
-  // Returns the interrupt budget which should be used for the profiler counter.
-  V8_EXPORT_PRIVATE static int InterruptBudget();
-
   // Creates a compilation job which will generate bytecode for |literal|.
   // Additionally, if |eager_inner_literals| is not null, adds any eagerly
   // compilable inner FunctionLiterals to this list.
diff --git a/deps/v8/src/json/json-parser.cc b/deps/v8/src/json/json-parser.cc
index 928bca4d52..becf21cd4e 100644
--- a/deps/v8/src/json/json-parser.cc
+++ b/deps/v8/src/json/json-parser.cc
@@ -267,7 +267,7 @@ void JsonParser<Char>::ReportUnexpectedToken(JsonToken token) {
 
   Handle<Script> script(factory->NewScript(original_source_));
   if (isolate()->NeedsSourcePositionsForProfiling()) {
-    Script::InitLineEnds(script);
+    Script::InitLineEnds(isolate(), script);
   }
   // We should sent compile error event because we compile JSON object in
   // separated source file.
diff --git a/deps/v8/src/libplatform/tracing/DEPS b/deps/v8/src/libplatform/tracing/DEPS
index 7a45bba55a..6d81016d6a 100644
--- a/deps/v8/src/libplatform/tracing/DEPS
+++ b/deps/v8/src/libplatform/tracing/DEPS
@@ -1,4 +1,5 @@
 include_rules = [
+  "+libplatform",
   "+perfetto",
   "+protos/perfetto",
 ]
diff --git a/deps/v8/src/libplatform/tracing/json-trace-event-listener.h b/deps/v8/src/libplatform/tracing/json-trace-event-listener.h
index d13332871f..a0ab31c981 100644
--- a/deps/v8/src/libplatform/tracing/json-trace-event-listener.h
+++ b/deps/v8/src/libplatform/tracing/json-trace-event-listener.h
@@ -7,6 +7,7 @@
 
 #include <ostream>
 
+#include "libplatform/libplatform-export.h"
 #include "src/libplatform/tracing/trace-event-listener.h"
 
 namespace perfetto {
@@ -21,7 +22,8 @@ namespace tracing {
 
 // A listener that converts the proto trace data to JSON and writes it to a
 // file.
-class JSONTraceEventListener final : public TraceEventListener {
+class V8_PLATFORM_EXPORT JSONTraceEventListener final
+    : public TraceEventListener {
  public:
   explicit JSONTraceEventListener(std::ostream* stream);
   ~JSONTraceEventListener() override;
diff --git a/deps/v8/src/libplatform/tracing/trace-event-listener.h b/deps/v8/src/libplatform/tracing/trace-event-listener.h
index 6a535c79c5..f8fa7932e8 100644
--- a/deps/v8/src/libplatform/tracing/trace-event-listener.h
+++ b/deps/v8/src/libplatform/tracing/trace-event-listener.h
@@ -7,6 +7,8 @@
 
 #include <vector>
 
+#include "libplatform/libplatform-export.h"
+
 namespace perfetto {
 namespace protos {
 class TracePacket;
@@ -22,7 +24,7 @@ namespace tracing {
 // the PerfettoConsumer class has to perform. Clients override ProcessPacket()
 // to respond to trace events, e.g. to write them to a file as JSON or for
 // testing purposes.
-class TraceEventListener {
+class V8_PLATFORM_EXPORT TraceEventListener {
  public:
   virtual ~TraceEventListener() = default;
   virtual void ProcessPacket(const ::perfetto::protos::TracePacket& packet) = 0;
diff --git a/deps/v8/src/libsampler/sampler.cc b/deps/v8/src/libsampler/sampler.cc
index 9677b58c19..e2091ceb32 100644
--- a/deps/v8/src/libsampler/sampler.cc
+++ b/deps/v8/src/libsampler/sampler.cc
@@ -372,7 +372,9 @@ void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
 void SignalHandler::FillRegisterState(void* context, RegisterState* state) {
   // Extracting the sample from the context is extremely machine dependent.
   ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
-#if !(V8_OS_OPENBSD || (V8_OS_LINUX && (V8_HOST_ARCH_PPC || V8_HOST_ARCH_S390)))
+#if !(V8_OS_OPENBSD || \
+      (V8_OS_LINUX &&  \
+       (V8_HOST_ARCH_PPC || V8_HOST_ARCH_S390 || V8_HOST_ARCH_PPC64)))
   mcontext_t& mcontext = ucontext->uc_mcontext;
 #endif
 #if V8_OS_LINUX
@@ -413,7 +415,7 @@ void SignalHandler::FillRegisterState(void* context, RegisterState* state) {
   state->pc = reinterpret_cast<void*>(mcontext.pc);
   state->sp = reinterpret_cast<void*>(mcontext.gregs[29]);
   state->fp = reinterpret_cast<void*>(mcontext.gregs[30]);
-#elif V8_HOST_ARCH_PPC
+#elif V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64
 #if V8_LIBC_GLIBC
   state->pc = reinterpret_cast<void*>(ucontext->uc_mcontext.regs->nip);
   state->sp =
diff --git a/deps/v8/src/logging/counters-definitions.h b/deps/v8/src/logging/counters-definitions.h
index 531d8c1411..32f7e3e652 100644
--- a/deps/v8/src/logging/counters-definitions.h
+++ b/deps/v8/src/logging/counters-definitions.h
@@ -55,19 +55,9 @@ namespace internal {
      51)                                                                       \
   HR(wasm_wasm_max_mem_pages_count, V8.WasmMaxMemPagesCount.wasm, 1, 2 << 16,  \
      51)                                                                       \
-  HR(wasm_decode_asm_module_peak_memory_bytes,                                 \
-     V8.WasmDecodeModulePeakMemoryBytes.asm, 1, GB, 51)                        \
-  HR(wasm_decode_wasm_module_peak_memory_bytes,                                \
-     V8.WasmDecodeModulePeakMemoryBytes.wasm, 1, GB, 51)                       \
-  HR(asm_wasm_translation_peak_memory_bytes,                                   \
-     V8.AsmWasmTranslationPeakMemoryBytes, 1, GB, 51)                          \
   HR(wasm_compile_function_peak_memory_bytes,                                  \
      V8.WasmCompileFunctionPeakMemoryBytes, 1, GB, 51)                         \
   HR(asm_module_size_bytes, V8.AsmModuleSizeBytes, 1, GB, 51)                  \
-  HR(asm_wasm_translation_throughput, V8.AsmWasmTranslationThroughput, 1, 100, \
-     20)                                                                       \
-  HR(wasm_lazy_compilation_throughput, V8.WasmLazyCompilationThroughput, 1,    \
-     10000, 50)                                                                \
   HR(compile_script_cache_behaviour, V8.CompileScript.CacheBehaviour, 0, 20,   \
      21)                                                                       \
   HR(wasm_memory_allocation_result, V8.WasmMemoryAllocationResult, 0, 3, 4)    \
@@ -81,8 +71,6 @@ namespace internal {
   /* code size per module after top-tier compilation */                        \
   HR(wasm_module_code_size_mb_after_top_tier, V8.WasmModuleCodeSizeTopTierMiB, \
      0, 1024, 64)                                                              \
-  /* freed code size per module, collected on GC */                            \
-  HR(wasm_module_freed_code_size_mb, V8.WasmModuleCodeSizeFreed, 0, 1024, 64)  \
   /* percent of freed code size per module, collected on GC */                 \
   HR(wasm_module_freed_code_size_percent, V8.WasmModuleCodeSizePercentFreed,   \
      0, 100, 32)                                                               \
@@ -124,12 +112,7 @@ namespace internal {
   /* Total compilation time incl. caching/parsing */                           \
   HT(compile_script, V8.CompileScriptMicroSeconds, 1000000, MICROSECOND)       \
   /* Total JavaScript execution time (including callbacks and runtime calls */ \
-  HT(execute, V8.Execute, 1000000, MICROSECOND)                                \
-  /* Asm/Wasm */                                                               \
-  HT(asm_wasm_translation_time, V8.AsmWasmTranslationMicroSeconds, 1000000,    \
-     MICROSECOND)                                                              \
-  HT(wasm_lazy_compilation_time, V8.WasmLazyCompilationMicroSeconds, 1000000,  \
-     MICROSECOND)
+  HT(execute, V8.Execute, 1000000, MICROSECOND)
 
 #define TIMED_HISTOGRAM_LIST(HT)                                               \
   /* Timer histograms, thread safe: HT(name, caption, max, unit) */            \
@@ -140,6 +123,8 @@ namespace internal {
   HT(gc_finalize, V8.GCFinalizeMC, 10000, MILLISECOND)                         \
   HT(gc_finalize_background, V8.GCFinalizeMCBackground, 10000, MILLISECOND)    \
   HT(gc_finalize_foreground, V8.GCFinalizeMCForeground, 10000, MILLISECOND)    \
+  HT(gc_finalize_measure_memory, V8.GCFinalizeMCMeasureMemory, 10000,          \
+     MILLISECOND)                                                              \
   HT(gc_finalize_reduce_memory, V8.GCFinalizeMCReduceMemory, 10000,            \
      MILLISECOND)                                                              \
   HT(gc_finalize_reduce_memory_background,                                     \
@@ -149,6 +134,8 @@ namespace internal {
   HT(gc_scavenger, V8.GCScavenger, 10000, MILLISECOND)                         \
   HT(gc_scavenger_background, V8.GCScavengerBackground, 10000, MILLISECOND)    \
   HT(gc_scavenger_foreground, V8.GCScavengerForeground, 10000, MILLISECOND)    \
+  HT(measure_memory_delay_ms, V8.MeasureMemoryDelayMilliseconds, 100000,       \
+     MILLISECOND)                                                              \
   /* TurboFan timers. */                                                       \
   HT(turbofan_optimize_prepare, V8.TurboFanOptimizePrepare, 1000000,           \
      MICROSECOND)                                                              \
@@ -175,14 +162,6 @@ namespace internal {
   HT(turbofan_osr_total_time,                                                  \
      V8.TurboFanOptimizeForOnStackReplacementTotalTime, 10000000, MICROSECOND) \
   /* Wasm timers. */                                                           \
-  HT(wasm_decode_asm_module_time, V8.WasmDecodeModuleMicroSeconds.asm,         \
-     1000000, MICROSECOND)                                                     \
-  HT(wasm_decode_wasm_module_time, V8.WasmDecodeModuleMicroSeconds.wasm,       \
-     1000000, MICROSECOND)                                                     \
-  HT(wasm_decode_asm_function_time, V8.WasmDecodeFunctionMicroSeconds.asm,     \
-     1000000, MICROSECOND)                                                     \
-  HT(wasm_decode_wasm_function_time, V8.WasmDecodeFunctionMicroSeconds.wasm,   \
-     1000000, MICROSECOND)                                                     \
   HT(wasm_compile_asm_module_time, V8.WasmCompileModuleMicroSeconds.asm,       \
      10000000, MICROSECOND)                                                    \
   HT(wasm_compile_wasm_module_time, V8.WasmCompileModuleMicroSeconds.wasm,     \
@@ -205,7 +184,6 @@ namespace internal {
      V8.WasmInstantiateModuleMicroSeconds.wasm, 10000000, MICROSECOND)         \
   HT(wasm_instantiate_asm_module_time,                                         \
      V8.WasmInstantiateModuleMicroSeconds.asm, 10000000, MICROSECOND)          \
-  HT(wasm_code_gc_time, V8.WasmCodeGCTime, 1000000, MICROSECOND)               \
   /* Total compilation time incl. caching/parsing for various cache states. */ \
   HT(compile_script_with_produce_cache,                                        \
      V8.CompileScriptMicroSeconds.ProduceCache, 1000000, MICROSECOND)          \
diff --git a/deps/v8/src/logging/counters.cc b/deps/v8/src/logging/counters.cc
index 03b210f4d3..21248389b2 100644
--- a/deps/v8/src/logging/counters.cc
+++ b/deps/v8/src/logging/counters.cc
@@ -319,6 +319,11 @@ void Counters::ResetCreateHistogramFunction(CreateHistogramCallback f) {
 base::TimeTicks (*RuntimeCallTimer::Now)() =
     &base::TimeTicks::HighResolutionNow;
 
+base::TimeTicks RuntimeCallTimer::NowCPUTime() {
+  base::ThreadTicks ticks = base::ThreadTicks::Now();
+  return base::TimeTicks::FromInternalValue(ticks.ToInternalValue());
+}
+
 class RuntimeCallStatEntries {
  public:
   void Print(std::ostream& os) {
@@ -454,6 +459,11 @@ RuntimeCallStats::RuntimeCallStats(ThreadType thread_type)
   for (int i = 0; i < kNumberOfCounters; i++) {
     this->counters_[i] = RuntimeCallCounter(kNames[i]);
   }
+  if (FLAG_rcs_cpu_time) {
+    CHECK(base::ThreadTicks::IsSupported());
+    base::ThreadTicks::WaitUntilInitialized();
+    RuntimeCallTimer::Now = &RuntimeCallTimer::NowCPUTime;
+  }
 }
 
 namespace {
diff --git a/deps/v8/src/logging/counters.h b/deps/v8/src/logging/counters.h
index a2c918e4c1..44d4278896 100644
--- a/deps/v8/src/logging/counters.h
+++ b/deps/v8/src/logging/counters.h
@@ -714,6 +714,9 @@ class RuntimeCallTimer final {
   // Make the time source configurable for testing purposes.
   V8_EXPORT_PRIVATE static base::TimeTicks (*Now)();
 
+  // Helper to switch over to CPU time.
+  static base::TimeTicks NowCPUTime();
+
  private:
   inline void Pause(base::TimeTicks now);
   inline void Resume(base::TimeTicks now);
@@ -735,6 +738,7 @@ class RuntimeCallTimer final {
   V(ArrayBuffer_Detach)                                    \
   V(ArrayBuffer_New)                                       \
   V(ArrayBuffer_NewBackingStore)                           \
+  V(ArrayBuffer_BackingStore_Reallocate)                   \
   V(Array_CloneElementAt)                                  \
   V(Array_New)                                             \
   V(BigInt64Array_New)                                     \
@@ -861,6 +865,7 @@ class RuntimeCallTimer final {
   V(String_NewFromOneByte)                                 \
   V(String_NewFromTwoByte)                                 \
   V(String_NewFromUtf8)                                    \
+  V(String_NewFromUtf8Literal)                             \
   V(StringObject_New)                                      \
   V(StringObject_StringValue)                              \
   V(String_Write)                                          \
@@ -903,6 +908,7 @@ class RuntimeCallTimer final {
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Eval)                         \
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Function)                     \
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Ignition)                     \
+  ADD_THREAD_SPECIFIC_COUNTER(V, Compile, IgnitionFinalization)         \
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, RewriteReturnResult)          \
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, ScopeAnalysis)                \
   ADD_THREAD_SPECIFIC_COUNTER(V, Compile, Script)                       \
@@ -982,12 +988,13 @@ class RuntimeCallTimer final {
   V(CompileFinalizeBackgroundCompileTask)      \
   V(CompileFinishNowOnDispatcher)              \
   V(CompileGetFromOptimizedCodeMap)            \
-  V(CompileIgnitionFinalization)               \
+  V(CompilePublishBackgroundFinalization)      \
   V(CompileSerialize)                          \
   V(CompileWaitForDispatcher)                  \
   V(DeoptimizeCode)                            \
   V(DeserializeContext)                        \
   V(DeserializeIsolate)                        \
+  V(FinalizationRegistryCleanupFromTask)       \
   V(FunctionCallback)                          \
   V(FunctionLengthGetter)                      \
   V(FunctionPrototypeGetter)                   \
diff --git a/deps/v8/src/logging/log.cc b/deps/v8/src/logging/log.cc
index 0343db987f..dc79ffda5e 100644
--- a/deps/v8/src/logging/log.cc
+++ b/deps/v8/src/logging/log.cc
@@ -238,11 +238,8 @@ void CodeEventLogger::CodeCreateEvent(LogEventsAndTags tag,
                                       const wasm::WasmCode* code,
                                       wasm::WasmName name) {
   name_buffer_->Init(tag);
-  if (name.empty()) {
-    name_buffer_->AppendBytes("<wasm-unnamed>");
-  } else {
-    name_buffer_->AppendBytes(name.begin(), name.length());
-  }
+  DCHECK(!name.empty());
+  name_buffer_->AppendBytes(name.begin(), name.length());
   name_buffer_->AppendByte('-');
   if (code->IsAnonymous()) {
     name_buffer_->AppendBytes("<anonymous>");
@@ -587,6 +584,8 @@ void LowLevelLogger::LogCodeInfo() {
   const char arch[] = "arm";
 #elif V8_TARGET_ARCH_PPC
   const char arch[] = "ppc";
+#elif V8_TARGET_ARCH_PPC64
+  const char arch[] = "ppc64";
 #elif V8_TARGET_ARCH_MIPS
   const char arch[] = "mips";
 #elif V8_TARGET_ARCH_ARM64
@@ -1303,11 +1302,9 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag, const wasm::WasmCode* code,
   AppendCodeCreateHeader(msg, tag, AbstractCode::Kind::WASM_FUNCTION,
                          code->instructions().begin(),
                          code->instructions().length(), &timer_);
-  if (name.empty()) {
-    msg << "<unknown wasm>";
-  } else {
-    msg.AppendString(name);
-  }
+  DCHECK(!name.empty());
+  msg.AppendString(name);
+
   // We have to add two extra fields that allow the tick processor to group
   // events for the same wasm function, even if it gets compiled again. For
   // normal JS functions, we use the shared function info. For wasm, the pointer
@@ -1355,8 +1352,8 @@ void Logger::RegExpCodeCreateEvent(Handle<AbstractCode> code,
 
 void Logger::CodeMoveEvent(AbstractCode from, AbstractCode to) {
   if (!is_listening_to_code_events()) return;
-  MoveEventInternal(CodeEventListener::CODE_MOVE_EVENT, from.address(),
-                    to.address());
+  MoveEventInternal(CodeEventListener::CODE_MOVE_EVENT, from.InstructionStart(),
+                    to.InstructionStart());
 }
 
 void Logger::SharedFunctionInfoMoveEvent(Address from, Address to) {
@@ -1641,9 +1638,9 @@ void Logger::TickEvent(TickSample* sample, bool overflow) {
   msg.WriteToLogFile();
 }
 
-void Logger::ICEvent(const char* type, bool keyed, Map map, Object key,
-                     char old_state, char new_state, const char* modifier,
-                     const char* slow_stub_reason) {
+void Logger::ICEvent(const char* type, bool keyed, Handle<Map> map,
+                     Handle<Object> key, char old_state, char new_state,
+                     const char* modifier, const char* slow_stub_reason) {
   if (!log_->IsEnabled() || !FLAG_trace_ic) return;
   Log::MessageBuilder msg(log_.get());
   if (keyed) msg << "Keyed";
@@ -1652,13 +1649,13 @@ void Logger::ICEvent(const char* type, bool keyed, Map map, Object key,
   Address pc = isolate_->GetAbstractPC(&line, &column);
   msg << type << kNext << reinterpret_cast<void*>(pc) << kNext << line << kNext
       << column << kNext << old_state << kNext << new_state << kNext
-      << AsHex::Address(map.ptr()) << kNext;
-  if (key.IsSmi()) {
-    msg << Smi::ToInt(key);
-  } else if (key.IsNumber()) {
-    msg << key.Number();
-  } else if (key.IsName()) {
-    msg << Name::cast(key);
+      << AsHex::Address(map.is_null() ? kNullAddress : map->ptr()) << kNext;
+  if (key->IsSmi()) {
+    msg << Smi::ToInt(*key);
+  } else if (key->IsNumber()) {
+    msg << key->Number();
+  } else if (key->IsName()) {
+    msg << Name::cast(*key);
   }
   msg << kNext << modifier << kNext;
   if (slow_stub_reason != nullptr) {
@@ -1667,11 +1664,10 @@ void Logger::ICEvent(const char* type, bool keyed, Map map, Object key,
   msg.WriteToLogFile();
 }
 
-void Logger::MapEvent(const char* type, Map from, Map to, const char* reason,
-                      HeapObject name_or_sfi) {
-  DisallowHeapAllocation no_gc;
+void Logger::MapEvent(const char* type, Handle<Map> from, Handle<Map> to,
+                      const char* reason, Handle<HeapObject> name_or_sfi) {
   if (!log_->IsEnabled() || !FLAG_trace_maps) return;
-  if (!to.is_null()) MapDetails(to);
+  if (!to.is_null()) MapDetails(*to);
   int line = -1;
   int column = -1;
   Address pc = 0;
@@ -1681,15 +1677,16 @@ void Logger::MapEvent(const char* type, Map from, Map to, const char* reason,
   }
   Log::MessageBuilder msg(log_.get());
   msg << "map" << kNext << type << kNext << timer_.Elapsed().InMicroseconds()
-      << kNext << AsHex::Address(from.ptr()) << kNext
-      << AsHex::Address(to.ptr()) << kNext << AsHex::Address(pc) << kNext
-      << line << kNext << column << kNext << reason << kNext;
+      << kNext << AsHex::Address(from.is_null() ? kNullAddress : from->ptr())
+      << kNext << AsHex::Address(to.is_null() ? kNullAddress : to->ptr())
+      << kNext << AsHex::Address(pc) << kNext << line << kNext << column
+      << kNext << reason << kNext;
 
   if (!name_or_sfi.is_null()) {
-    if (name_or_sfi.IsName()) {
-      msg << Name::cast(name_or_sfi);
-    } else if (name_or_sfi.IsSharedFunctionInfo()) {
-      SharedFunctionInfo sfi = SharedFunctionInfo::cast(name_or_sfi);
+    if (name_or_sfi->IsName()) {
+      msg << Name::cast(*name_or_sfi);
+    } else if (name_or_sfi->IsSharedFunctionInfo()) {
+      SharedFunctionInfo sfi = SharedFunctionInfo::cast(*name_or_sfi);
       msg << sfi.DebugName();
 #if V8_SFI_HAS_UNIQUE_ID
       msg << " " << sfi.unique_id();
diff --git a/deps/v8/src/logging/log.h b/deps/v8/src/logging/log.h
index 16f8f69e60..9e4dfeb28d 100644
--- a/deps/v8/src/logging/log.h
+++ b/deps/v8/src/logging/log.h
@@ -70,15 +70,15 @@ class Profiler;
 class Ticker;
 
 #undef LOG
-#define LOG(isolate, Call)                              \
-  do {                                                  \
-    v8::internal::Logger* logger = (isolate)->logger(); \
-    if (logger->is_logging()) logger->Call;             \
+#define LOG(isolate, Call)                  \
+  do {                                      \
+    auto* logger = (isolate)->logger();     \
+    if (logger->is_logging()) logger->Call; \
   } while (false)
 
 #define LOG_CODE_EVENT(isolate, Call)                        \
   do {                                                       \
-    v8::internal::Logger* logger = (isolate)->logger();      \
+    auto* logger = (isolate)->logger();                      \
     if (logger->is_listening_to_code_events()) logger->Call; \
   } while (false)
 
@@ -222,14 +222,13 @@ class Logger : public CodeEventListener {
 
   void CodeNameEvent(Address addr, int pos, const char* code_name);
 
+  void ICEvent(const char* type, bool keyed, Handle<Map> map,
+               Handle<Object> key, char old_state, char new_state,
+               const char* modifier, const char* slow_stub_reason);
 
-  void ICEvent(const char* type, bool keyed, Map map, Object key,
-               char old_state, char new_state, const char* modifier,
-               const char* slow_stub_reason);
-
-  void MapEvent(const char* type, Map from, Map to,
+  void MapEvent(const char* type, Handle<Map> from, Handle<Map> to,
                 const char* reason = nullptr,
-                HeapObject name_or_sfi = HeapObject());
+                Handle<HeapObject> name_or_sfi = Handle<HeapObject>());
   void MapCreate(Map map);
   void MapDetails(Map map);
 
diff --git a/deps/v8/src/logging/off-thread-logger.h b/deps/v8/src/logging/off-thread-logger.h
new file mode 100644
index 0000000000..fab58c311b
--- /dev/null
+++ b/deps/v8/src/logging/off-thread-logger.h
@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_LOGGING_OFF_THREAD_LOGGER_H_
+#define V8_LOGGING_OFF_THREAD_LOGGER_H_
+
+#include "src/base/logging.h"
+#include "src/logging/log.h"
+
+namespace v8 {
+namespace internal {
+
+// TODO(leszeks): Add support for logging from off-thread.
+class OffThreadLogger {
+ public:
+  bool is_logging() const { return false; }
+  bool is_listening_to_code_events() const { return false; }
+  void ScriptEvent(Logger::ScriptEventType type, int script_id) {
+    UNREACHABLE();
+  }
+  void CodeLinePosInfoRecordEvent(Address code_start,
+                                  ByteArray source_position_table) {
+    UNREACHABLE();
+  }
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_LOGGING_OFF_THREAD_LOGGER_H_
diff --git a/deps/v8/src/numbers/conversions-inl.h b/deps/v8/src/numbers/conversions-inl.h
index f9d5346ef3..42a30b3428 100644
--- a/deps/v8/src/numbers/conversions-inl.h
+++ b/deps/v8/src/numbers/conversions-inl.h
@@ -81,7 +81,9 @@ inline float DoubleToFloat32(double x) {
 
 inline double DoubleToInteger(double x) {
   if (std::isnan(x)) return 0;
-  if (!std::isfinite(x) || x == 0) return x;
+  if (!std::isfinite(x)) return x;
+  // ToInteger normalizes -0 to +0.
+  if (x == 0.0) return 0;
   return (x >= 0) ? std::floor(x) : std::ceil(x);
 }
 
diff --git a/deps/v8/src/numbers/conversions.cc b/deps/v8/src/numbers/conversions.cc
index faf3e33df3..dfbd1d03fe 100644
--- a/deps/v8/src/numbers/conversions.cc
+++ b/deps/v8/src/numbers/conversions.cc
@@ -9,6 +9,7 @@
 #include <cmath>
 
 #include "src/common/assert-scope.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/handles/handles.h"
 #include "src/heap/factory.h"
 #include "src/numbers/dtoa.h"
@@ -167,25 +168,35 @@ double InternalStringToIntDouble(Iterator current, EndMark end, bool negative,
   return std::ldexp(static_cast<double>(negative ? -number : number), exponent);
 }
 
+namespace {
+
+// Subclasses of StringToIntHelper get access to internal state:
+enum class State { kRunning, kError, kJunk, kEmpty, kZero, kDone };
+
+enum class Sign { kNegative, kPositive, kNone };
+
+}  // namespace
+
 // ES6 18.2.5 parseInt(string, radix) (with NumberParseIntHelper subclass);
 // and BigInt parsing cases from https://tc39.github.io/proposal-bigint/
 // (with StringToBigIntHelper subclass).
+template <typename LocalIsolate>
 class StringToIntHelper {
  public:
-  StringToIntHelper(Isolate* isolate, Handle<String> subject, int radix)
+  StringToIntHelper(LocalIsolate* isolate, Handle<String> subject, int radix)
       : isolate_(isolate), subject_(subject), radix_(radix) {
     DCHECK(subject->IsFlat());
   }
 
   // Used for the StringToBigInt operation.
-  StringToIntHelper(Isolate* isolate, Handle<String> subject)
+  StringToIntHelper(LocalIsolate* isolate, Handle<String> subject)
       : isolate_(isolate), subject_(subject) {
     DCHECK(subject->IsFlat());
   }
 
   // Used for parsing BigInt literals, where the input is a Zone-allocated
   // buffer of one-byte digits, along with an optional radix prefix.
-  StringToIntHelper(Isolate* isolate, const uint8_t* subject, int length)
+  StringToIntHelper(LocalIsolate* isolate, const uint8_t* subject, int length)
       : isolate_(isolate), raw_one_byte_subject_(subject), length_(length) {}
   virtual ~StringToIntHelper() = default;
 
@@ -225,12 +236,7 @@ class StringToIntHelper {
     return subject_->GetFlatContent(no_gc).ToUC16Vector();
   }
 
-  // Subclasses get access to internal state:
-  enum State { kRunning, kError, kJunk, kEmpty, kZero, kDone };
-
-  enum class Sign { kNegative, kPositive, kNone };
-
-  Isolate* isolate() { return isolate_; }
+  LocalIsolate* isolate() { return isolate_; }
   int radix() { return radix_; }
   int cursor() { return cursor_; }
   int length() { return length_; }
@@ -245,7 +251,7 @@ class StringToIntHelper {
   template <class Char>
   void ParseInternal(Char start);
 
-  Isolate* isolate_;
+  LocalIsolate* isolate_;
   Handle<String> subject_;
   const uint8_t* raw_one_byte_subject_ = nullptr;
   int radix_ = 0;
@@ -255,10 +261,11 @@ class StringToIntHelper {
   bool leading_zero_ = false;
   bool allow_binary_and_octal_prefixes_ = false;
   bool allow_trailing_junk_ = true;
-  State state_ = kRunning;
+  State state_ = State::kRunning;
 };
 
-void StringToIntHelper::ParseInt() {
+template <typename LocalIsolate>
+void StringToIntHelper<LocalIsolate>::ParseInt() {
   {
     DisallowHeapAllocation no_gc;
     if (IsOneByte()) {
@@ -269,10 +276,10 @@ void StringToIntHelper::ParseInt() {
       DetectRadixInternal(vector.begin(), vector.length());
     }
   }
-  if (state_ != kRunning) return;
+  if (state_ != State::kRunning) return;
   AllocateResult();
   HandleSpecialCases();
-  if (state_ != kRunning) return;
+  if (state_ != State::kRunning) return;
   {
     DisallowHeapAllocation no_gc;
     if (IsOneByte()) {
@@ -285,30 +292,32 @@ void StringToIntHelper::ParseInt() {
       ParseInternal(vector.begin());
     }
   }
-  DCHECK_NE(state_, kRunning);
+  DCHECK_NE(state_, State::kRunning);
 }
 
+template <typename LocalIsolate>
 template <class Char>
-void StringToIntHelper::DetectRadixInternal(Char current, int length) {
+void StringToIntHelper<LocalIsolate>::DetectRadixInternal(Char current,
+                                                          int length) {
   Char start = current;
   length_ = length;
   Char end = start + length;
 
   if (!AdvanceToNonspace(&current, end)) {
-    return set_state(kEmpty);
+    return set_state(State::kEmpty);
   }
 
   if (*current == '+') {
     // Ignore leading sign; skip following spaces.
     ++current;
     if (current == end) {
-      return set_state(kJunk);
+      return set_state(State::kJunk);
     }
     sign_ = Sign::kPositive;
   } else if (*current == '-') {
     ++current;
     if (current == end) {
-      return set_state(kJunk);
+      return set_state(State::kJunk);
     }
     sign_ = Sign::kNegative;
   }
@@ -318,21 +327,21 @@ void StringToIntHelper::DetectRadixInternal(Char current, int length) {
     radix_ = 10;
     if (*current == '0') {
       ++current;
-      if (current == end) return set_state(kZero);
+      if (current == end) return set_state(State::kZero);
       if (*current == 'x' || *current == 'X') {
         radix_ = 16;
         ++current;
-        if (current == end) return set_state(kJunk);
+        if (current == end) return set_state(State::kJunk);
       } else if (allow_binary_and_octal_prefixes_ &&
                  (*current == 'o' || *current == 'O')) {
         radix_ = 8;
         ++current;
-        if (current == end) return set_state(kJunk);
+        if (current == end) return set_state(State::kJunk);
       } else if (allow_binary_and_octal_prefixes_ &&
                  (*current == 'b' || *current == 'B')) {
         radix_ = 2;
         ++current;
-        if (current == end) return set_state(kJunk);
+        if (current == end) return set_state(State::kJunk);
       } else {
         leading_zero_ = true;
       }
@@ -341,10 +350,10 @@ void StringToIntHelper::DetectRadixInternal(Char current, int length) {
     if (*current == '0') {
       // Allow "0x" prefix.
       ++current;
-      if (current == end) return set_state(kZero);
+      if (current == end) return set_state(State::kZero);
       if (*current == 'x' || *current == 'X') {
         ++current;
-        if (current == end) return set_state(kJunk);
+        if (current == end) return set_state(State::kJunk);
       } else {
         leading_zero_ = true;
       }
@@ -354,11 +363,11 @@ void StringToIntHelper::DetectRadixInternal(Char current, int length) {
   while (*current == '0') {
     leading_zero_ = true;
     ++current;
-    if (current == end) return set_state(kZero);
+    if (current == end) return set_state(State::kZero);
   }
 
   if (!leading_zero_ && !isDigit(*current, radix_)) {
-    return set_state(kJunk);
+    return set_state(State::kJunk);
   }
 
   DCHECK(radix_ >= 2 && radix_ <= 36);
@@ -366,8 +375,9 @@ void StringToIntHelper::DetectRadixInternal(Char current, int length) {
   cursor_ = static_cast<int>(current - start);
 }
 
+template <typename LocalIsolate>
 template <class Char>
-void StringToIntHelper::ParseInternal(Char start) {
+void StringToIntHelper<LocalIsolate>::ParseInternal(Char start) {
   Char current = start + cursor_;
   Char end = start + length_;
 
@@ -426,13 +436,13 @@ void StringToIntHelper::ParseInternal(Char start) {
   } while (!done);
 
   if (!allow_trailing_junk_ && AdvanceToNonspace(&current, end)) {
-    return set_state(kJunk);
+    return set_state(State::kJunk);
   }
 
-  return set_state(kDone);
+  return set_state(State::kDone);
 }
 
-class NumberParseIntHelper : public StringToIntHelper {
+class NumberParseIntHelper : public StringToIntHelper<Isolate> {
  public:
   NumberParseIntHelper(Isolate* isolate, Handle<String> string, int radix)
       : StringToIntHelper(isolate, string, radix) {}
@@ -440,15 +450,15 @@ class NumberParseIntHelper : public StringToIntHelper {
   double GetResult() {
     ParseInt();
     switch (state()) {
-      case kJunk:
-      case kEmpty:
+      case State::kJunk:
+      case State::kEmpty:
         return JunkStringValue();
-      case kZero:
+      case State::kZero:
         return SignedZero(negative());
-      case kDone:
+      case State::kDone:
         return negative() ? -result_ : result_;
-      case kError:
-      case kRunning:
+      case State::kError:
+      case State::kRunning:
         break;
     }
     UNREACHABLE();
@@ -476,7 +486,7 @@ class NumberParseIntHelper : public StringToIntHelper {
       result_ = is_power_of_two ? HandlePowerOfTwoCase(vector.begin())
                                 : HandleBaseTenCase(vector.begin());
     }
-    set_state(kDone);
+    set_state(State::kDone);
   }
 
   template <class Char>
@@ -573,7 +583,7 @@ double InternalStringToDouble(Iterator current, EndMark end, int flags,
 
   // The longest form of simplified number is: "-<significant digits>'.1eXXX\0".
   const int kBufferSize = kMaxSignificantDigits + 10;
-  char buffer[kBufferSize];  // NOLINT: size is known at compile time.
+  char buffer[kBufferSize];
   int buffer_pos = 0;
 
   // Exponent will be adjusted if insignificant digits of the integer part
@@ -825,59 +835,50 @@ double StringToInt(Isolate* isolate, Handle<String> string, int radix) {
   return helper.GetResult();
 }
 
-class StringToBigIntHelper : public StringToIntHelper {
+template <typename LocalIsolate>
+class StringToBigIntHelper : public StringToIntHelper<LocalIsolate> {
  public:
   enum class Behavior { kStringToBigInt, kLiteral };
 
   // Used for StringToBigInt operation (BigInt constructor and == operator).
-  StringToBigIntHelper(Isolate* isolate, Handle<String> string)
-      : StringToIntHelper(isolate, string),
+  StringToBigIntHelper(LocalIsolate* isolate, Handle<String> string)
+      : StringToIntHelper<LocalIsolate>(isolate, string),
         behavior_(Behavior::kStringToBigInt) {
-    set_allow_binary_and_octal_prefixes();
-    set_disallow_trailing_junk();
+    this->set_allow_binary_and_octal_prefixes();
+    this->set_disallow_trailing_junk();
   }
 
   // Used for parsing BigInt literals, where the input is a buffer of
   // one-byte ASCII digits, along with an optional radix prefix.
-  StringToBigIntHelper(Isolate* isolate, const uint8_t* string, int length)
-      : StringToIntHelper(isolate, string, length),
+  StringToBigIntHelper(LocalIsolate* isolate, const uint8_t* string, int length)
+      : StringToIntHelper<LocalIsolate>(isolate, string, length),
         behavior_(Behavior::kLiteral) {
-    set_allow_binary_and_octal_prefixes();
+    this->set_allow_binary_and_octal_prefixes();
   }
 
   MaybeHandle<BigInt> GetResult() {
-    ParseInt();
-    if (behavior_ == Behavior::kStringToBigInt && sign() != Sign::kNone &&
-        radix() != 10) {
+    this->ParseInt();
+    if (behavior_ == Behavior::kStringToBigInt && this->sign() != Sign::kNone &&
+        this->radix() != 10) {
       return MaybeHandle<BigInt>();
     }
-    if (state() == kEmpty) {
+    if (this->state() == State::kEmpty) {
       if (behavior_ == Behavior::kStringToBigInt) {
-        set_state(kZero);
+        this->set_state(State::kZero);
       } else {
         UNREACHABLE();
       }
     }
-    switch (state()) {
-      case kJunk:
-        if (should_throw() == kThrowOnError) {
-          THROW_NEW_ERROR(isolate(),
-                          NewSyntaxError(MessageTemplate::kBigIntInvalidString),
-                          BigInt);
-        } else {
-          DCHECK_EQ(should_throw(), kDontThrow);
-          return MaybeHandle<BigInt>();
-        }
-      case kZero:
-        return BigInt::Zero(isolate());
-      case kError:
-        DCHECK_EQ(should_throw() == kThrowOnError,
-                  isolate()->has_pending_exception());
+    switch (this->state()) {
+      case State::kJunk:
+      case State::kError:
         return MaybeHandle<BigInt>();
-      case kDone:
-        return BigInt::Finalize(result_, negative());
-      case kEmpty:
-      case kRunning:
+      case State::kZero:
+        return BigInt::Zero(this->isolate(), allocation_type());
+      case State::kDone:
+        return BigInt::Finalize<Isolate>(result_, this->negative());
+      case State::kEmpty:
+      case State::kRunning:
         break;
     }
     UNREACHABLE();
@@ -889,42 +890,50 @@ class StringToBigIntHelper : public StringToIntHelper {
     // Conseratively assume that all remaining digits are significant.
     // Optimization opportunity: Would it makes sense to scan for trailing
     // junk before allocating the result?
-    int charcount = length() - cursor();
-    // For literals, we pretenure the allocated BigInt, since it's about
-    // to be stored in the interpreter's constants array.
-    AllocationType allocation = behavior_ == Behavior::kLiteral
-                                    ? AllocationType::kOld
-                                    : AllocationType::kYoung;
-    MaybeHandle<FreshlyAllocatedBigInt> maybe = BigInt::AllocateFor(
-        isolate(), radix(), charcount, should_throw(), allocation);
+    int charcount = this->length() - this->cursor();
+    MaybeHandle<FreshlyAllocatedBigInt> maybe =
+        BigInt::AllocateFor(this->isolate(), this->radix(), charcount,
+                            kDontThrow, allocation_type());
     if (!maybe.ToHandle(&result_)) {
-      set_state(kError);
+      this->set_state(State::kError);
     }
   }
 
   void ResultMultiplyAdd(uint32_t multiplier, uint32_t part) override {
-    BigInt::InplaceMultiplyAdd(result_, static_cast<uintptr_t>(multiplier),
+    BigInt::InplaceMultiplyAdd(*result_, static_cast<uintptr_t>(multiplier),
                                static_cast<uintptr_t>(part));
   }
 
- private:
-  ShouldThrow should_throw() const { return kDontThrow; }
+  AllocationType allocation_type() {
+    // For literals, we pretenure the allocated BigInt, since it's about
+    // to be stored in the interpreter's constants array.
+    return behavior_ == Behavior::kLiteral ? AllocationType::kOld
+                                           : AllocationType::kYoung;
+  }
 
+ private:
   Handle<FreshlyAllocatedBigInt> result_;
   Behavior behavior_;
 };
 
 MaybeHandle<BigInt> StringToBigInt(Isolate* isolate, Handle<String> string) {
   string = String::Flatten(isolate, string);
-  StringToBigIntHelper helper(isolate, string);
+  StringToBigIntHelper<Isolate> helper(isolate, string);
   return helper.GetResult();
 }
 
-MaybeHandle<BigInt> BigIntLiteral(Isolate* isolate, const char* string) {
-  StringToBigIntHelper helper(isolate, reinterpret_cast<const uint8_t*>(string),
-                              static_cast<int>(strlen(string)));
+template <typename LocalIsolate>
+MaybeHandle<BigInt> BigIntLiteral(LocalIsolate* isolate, const char* string) {
+  StringToBigIntHelper<LocalIsolate> helper(
+      isolate, reinterpret_cast<const uint8_t*>(string),
+      static_cast<int>(strlen(string)));
   return helper.GetResult();
 }
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    MaybeHandle<BigInt> BigIntLiteral(Isolate* isolate, const char* string);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    MaybeHandle<BigInt> BigIntLiteral(OffThreadIsolate* isolate,
+                                      const char* string);
 
 const char* DoubleToCString(double v, Vector<char> buffer) {
   switch (FPCLASSIFY_NAMESPACE::fpclassify(v)) {
diff --git a/deps/v8/src/numbers/conversions.h b/deps/v8/src/numbers/conversions.h
index e71f7ce5d0..fa90ee2a6e 100644
--- a/deps/v8/src/numbers/conversions.h
+++ b/deps/v8/src/numbers/conversions.h
@@ -5,6 +5,7 @@
 #ifndef V8_NUMBERS_CONVERSIONS_H_
 #define V8_NUMBERS_CONVERSIONS_H_
 
+#include "src/base/export-template.h"
 #include "src/base/logging.h"
 #include "src/common/globals.h"
 #include "src/utils/vector.h"
@@ -99,8 +100,9 @@ MaybeHandle<BigInt> StringToBigInt(Isolate* isolate, Handle<String> string);
 //   0x -> hex
 //   0o -> octal
 //   0b -> binary
-V8_EXPORT_PRIVATE MaybeHandle<BigInt> BigIntLiteral(Isolate* isolate,
-                                                    const char* string);
+template <typename LocalIsolate>
+EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+MaybeHandle<BigInt> BigIntLiteral(LocalIsolate* isolate, const char* string);
 
 const int kDoubleToCStringMinBufferSize = 100;
 
diff --git a/deps/v8/src/objects/allocation-site-inl.h b/deps/v8/src/objects/allocation-site-inl.h
index cf17371928..f0788b7ca1 100644
--- a/deps/v8/src/objects/allocation-site-inl.h
+++ b/deps/v8/src/objects/allocation-site-inl.h
@@ -225,7 +225,7 @@ bool AllocationSite::DigestTransitionFeedback(Handle<AllocationSite> site,
         }
         JSObject::TransitionElementsKind(boilerplate, to_kind);
         site->dependent_code().DeoptimizeDependentCodeGroup(
-            isolate, DependentCode::kAllocationSiteTransitionChangedGroup);
+            DependentCode::kAllocationSiteTransitionChangedGroup);
         result = true;
       }
     }
@@ -245,7 +245,7 @@ bool AllocationSite::DigestTransitionFeedback(Handle<AllocationSite> site,
       }
       site->SetElementsKind(to_kind);
       site->dependent_code().DeoptimizeDependentCodeGroup(
-          isolate, DependentCode::kAllocationSiteTransitionChangedGroup);
+          DependentCode::kAllocationSiteTransitionChangedGroup);
       result = true;
     }
   }
diff --git a/deps/v8/src/objects/api-callbacks-inl.h b/deps/v8/src/objects/api-callbacks-inl.h
index a069e29807..0bec61a7b8 100644
--- a/deps/v8/src/objects/api-callbacks-inl.h
+++ b/deps/v8/src/objects/api-callbacks-inl.h
@@ -96,7 +96,6 @@ bool AccessorInfo::HasExpectedReceiverType() {
   return expected_receiver_type().IsFunctionTemplateInfo();
 }
 
-TQ_SMI_ACCESSORS(InterceptorInfo, flags)
 BOOL_ACCESSORS(InterceptorInfo, flags, can_intercept_symbols,
                kCanInterceptSymbolsBit)
 BOOL_ACCESSORS(InterceptorInfo, flags, all_can_read, kAllCanReadBit)
diff --git a/deps/v8/src/objects/api-callbacks.h b/deps/v8/src/objects/api-callbacks.h
index 2bf1a26b9a..77ff26d659 100644
--- a/deps/v8/src/objects/api-callbacks.h
+++ b/deps/v8/src/objects/api-callbacks.h
@@ -5,8 +5,8 @@
 #ifndef V8_OBJECTS_API_CALLBACKS_H_
 #define V8_OBJECTS_API_CALLBACKS_H_
 
-#include "src/base/bit-field.h"
 #include "src/objects/struct.h"
+#include "torque-generated/bit-fields-tq.h"
 #include "torque-generated/class-definitions-tq.h"
 
 // Has to be the last include (doesn't have include guards):
@@ -85,20 +85,8 @@ class AccessorInfo : public Struct {
  private:
   inline bool HasExpectedReceiverType();
 
-// Bit positions in |flags|.
-#define ACCESSOR_INFO_FLAGS_BIT_FIELDS(V, _)                           \
-  V(AllCanReadBit, bool, 1, _)                                         \
-  V(AllCanWriteBit, bool, 1, _)                                        \
-  V(IsSpecialDataPropertyBit, bool, 1, _)                              \
-  V(IsSloppyBit, bool, 1, _)                                           \
-  V(ReplaceOnAccessBit, bool, 1, _)                                    \
-  V(GetterSideEffectTypeBits, SideEffectType, 2, _)                    \
-  /* We could save a bit from setter side-effect type, if necessary */ \
-  V(SetterSideEffectTypeBits, SideEffectType, 2, _)                    \
-  V(InitialAttributesBits, PropertyAttributes, 3, _)
-
-  DEFINE_BIT_FIELDS(ACCESSOR_INFO_FLAGS_BIT_FIELDS)
-#undef ACCESSOR_INFO_FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_ACCESSOR_INFO_FLAGS()
 
   OBJECT_CONSTRUCTORS(AccessorInfo, Struct);
 };
@@ -123,9 +111,6 @@ class InterceptorInfo
   DECL_BOOLEAN_ACCESSORS(is_named)
   DECL_BOOLEAN_ACCESSORS(has_no_side_effect)
 
-  inline int flags() const;
-  inline void set_flags(int flags);
-
   // Dispatched behavior.
   DECL_PRINTER(InterceptorInfo)
 
diff --git a/deps/v8/src/objects/api-callbacks.tq b/deps/v8/src/objects/api-callbacks.tq
index 751acd1def..47d25546f5 100644
--- a/deps/v8/src/objects/api-callbacks.tq
+++ b/deps/v8/src/objects/api-callbacks.tq
@@ -30,9 +30,23 @@ extern class AccessCheckInfo extends Struct {
   data: Object;
 }
 
+type PropertyAttributes extends int32 constexpr 'PropertyAttributes';
+type SideEffectType extends int32 constexpr 'SideEffectType';
+
+bitfield struct AccessorInfoFlags extends uint31 {
+  all_can_read: bool: 1 bit;
+  all_can_write: bool: 1 bit;
+  is_special_data_property: bool: 1 bit;
+  is_sloppy: bool: 1 bit;
+  replace_on_access: bool: 1 bit;
+  getter_side_effect_type: SideEffectType: 2 bit;
+  setter_side_effect_type: SideEffectType: 2 bit;
+  initial_attributes: PropertyAttributes: 3 bit;
+}
+
 extern class AccessorInfo extends Struct {
   name: Object;
-  flags: Smi;
+  flags: SmiTagged<AccessorInfoFlags>;
   expected_receiver_type: Object;
   setter: NonNullForeign|Zero;
   getter: NonNullForeign|Zero;
diff --git a/deps/v8/src/objects/arguments-inl.h b/deps/v8/src/objects/arguments-inl.h
index feeb9dd1a9..8c49d909d2 100644
--- a/deps/v8/src/objects/arguments-inl.h
+++ b/deps/v8/src/objects/arguments-inl.h
@@ -24,8 +24,6 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(AliasedArgumentsEntry)
 
 CAST_ACCESSOR(SloppyArgumentsElements)
 
-TQ_SMI_ACCESSORS(AliasedArgumentsEntry, aliased_context_slot)
-
 DEF_GETTER(SloppyArgumentsElements, context, Context) {
   return TaggedField<Context>::load(isolate, *this,
                                     OffsetOfElementAt(kContextIndex));
diff --git a/deps/v8/src/objects/arguments.h b/deps/v8/src/objects/arguments.h
index c69545bfda..52cfb810fb 100644
--- a/deps/v8/src/objects/arguments.h
+++ b/deps/v8/src/objects/arguments.h
@@ -113,9 +113,6 @@ class AliasedArgumentsEntry
     : public TorqueGeneratedAliasedArgumentsEntry<AliasedArgumentsEntry,
                                                   Struct> {
  public:
-  inline int aliased_context_slot() const;
-  inline void set_aliased_context_slot(int count);
-
   // Dispatched behavior.
   DECL_PRINTER(AliasedArgumentsEntry)
 
diff --git a/deps/v8/src/objects/backing-store.cc b/deps/v8/src/objects/backing-store.cc
index ce138c9461..52ab0085f7 100644
--- a/deps/v8/src/objects/backing-store.cc
+++ b/deps/v8/src/objects/backing-store.cc
@@ -9,6 +9,7 @@
 #include "src/execution/isolate.h"
 #include "src/handles/global-handles.h"
 #include "src/logging/counters.h"
+#include "src/wasm/wasm-constants.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-objects-inl.h"
@@ -126,12 +127,12 @@ inline void DebugCheckZero(void* start, size_t byte_length) {
 
 bool BackingStore::ReserveAddressSpace(uint64_t num_bytes) {
   uint64_t reservation_limit = kAddressSpaceLimit;
+  uint64_t old_count = reserved_address_space_.load(std::memory_order_relaxed);
   while (true) {
-    uint64_t old_count = reserved_address_space_.load();
     if (old_count > reservation_limit) return false;
     if (reservation_limit - old_count < num_bytes) return false;
-    if (reserved_address_space_.compare_exchange_weak(old_count,
-                                                      old_count + num_bytes)) {
+    if (reserved_address_space_.compare_exchange_weak(
+            old_count, old_count + num_bytes, std::memory_order_acq_rel)) {
       return true;
     }
   }
@@ -164,10 +165,7 @@ void BackingStore::Clear() {
 BackingStore::~BackingStore() {
   GlobalBackingStoreRegistry::Unregister(this);
 
-  if (buffer_start_ == nullptr) {
-    Clear();
-    return;
-  }
+  if (buffer_start_ == nullptr) return;  // nothing to deallocate
 
   if (is_wasm_memory_) {
     DCHECK(free_on_destruct_);
@@ -265,7 +263,8 @@ std::unique_ptr<BackingStore> BackingStore::Allocate(
                                  false,         // is_wasm_memory
                                  true,          // free_on_destruct
                                  false,         // has_guard_regions
-                                 false);        // custom_deleter
+                                 false,         // custom_deleter
+                                 false);        // empty_deleter
 
   TRACE_BS("BS:alloc  bs=%p mem=%p (length=%zu)\n", result,
            result->buffer_start(), byte_length);
@@ -316,9 +315,11 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
 
   // Compute size of reserved memory.
 
-  size_t engine_max_pages = wasm::max_mem_pages();
-  size_t byte_capacity =
-      std::min(engine_max_pages, maximum_pages) * wasm::kWasmPageSize;
+  size_t engine_max_pages = wasm::max_maximum_mem_pages();
+  maximum_pages = std::min(engine_max_pages, maximum_pages);
+  CHECK_LE(maximum_pages,
+           std::numeric_limits<size_t>::max() / wasm::kWasmPageSize);
+  size_t byte_capacity = maximum_pages * wasm::kWasmPageSize;
   size_t reservation_size = GetReservationSize(guards, byte_capacity);
 
   //--------------------------------------------------------------------------
@@ -388,7 +389,8 @@ std::unique_ptr<BackingStore> BackingStore::TryAllocateWasmMemory(
                                  true,           // is_wasm_memory
                                  true,           // free_on_destruct
                                  guards,         // has_guard_regions
-                                 false);         // custom_deleter
+                                 false,          // custom_deleter
+                                 false);         // empty_deleter
 
   TRACE_BS("BSw:alloc bs=%p mem=%p (length=%zu, capacity=%zu)\n", result,
            result->buffer_start(), byte_length, byte_capacity);
@@ -411,7 +413,15 @@ std::unique_ptr<BackingStore> BackingStore::AllocateWasmMemory(
   DCHECK_EQ(0, wasm::kWasmPageSize % AllocatePageSize());
 
   // Enforce engine limitation on the maximum number of pages.
-  if (initial_pages > wasm::max_mem_pages()) return nullptr;
+  if (initial_pages > wasm::kV8MaxWasmMemoryPages) return nullptr;
+
+  // Trying to allocate 4 GiB on a 32-bit platform is guaranteed to fail.
+  // We don't lower the official max_maximum_mem_pages() limit because that
+  // would be observable upon instantiation; this way the effective limit
+  // on 32-bit platforms is defined by the allocator.
+  constexpr size_t kPlatformMax =
+      std::numeric_limits<size_t>::max() / wasm::kWasmPageSize;
+  if (initial_pages > kPlatformMax) return nullptr;
 
   auto backing_store =
       TryAllocateWasmMemory(isolate, initial_pages, maximum_pages, shared);
@@ -425,7 +435,6 @@ std::unique_ptr<BackingStore> BackingStore::AllocateWasmMemory(
 
 std::unique_ptr<BackingStore> BackingStore::CopyWasmMemory(Isolate* isolate,
                                                            size_t new_pages) {
-  DCHECK_GE(new_pages * wasm::kWasmPageSize, byte_length_);
   // Note that we could allocate uninitialized to save initialization cost here,
   // but since Wasm memories are allocated by the page allocator, the zeroing
   // cost is already built-in.
@@ -440,6 +449,9 @@ std::unique_ptr<BackingStore> BackingStore::CopyWasmMemory(Isolate* isolate,
   }
 
   if (byte_length_ > 0) {
+    // If the allocation was successful, then the new buffer must be at least
+    // as big as the old one.
+    DCHECK_GE(new_pages * wasm::kWasmPageSize, byte_length_);
     memcpy(new_backing_store->buffer_start(), buffer_start_, byte_length_);
   }
 
@@ -460,10 +472,9 @@ bool BackingStore::GrowWasmMemoryInPlace(Isolate* isolate, size_t delta_pages,
   // permissions for the entire range (to be RW), so the operating system
   // should deal with that raciness. We know we succeeded when we can
   // compare/swap the old length with the new length.
-  size_t old_length = 0;
+  size_t old_length = byte_length_.load(std::memory_order_relaxed);
   size_t new_length = 0;
   while (true) {
-    old_length = byte_length_.load(std::memory_order_acquire);
     size_t current_pages = old_length / wasm::kWasmPageSize;
 
     // Check if we have exceed the supplied maximum.
@@ -483,7 +494,7 @@ bool BackingStore::GrowWasmMemoryInPlace(Isolate* isolate, size_t delta_pages,
     }
   }
 
-  if (!is_shared_) {
+  if (!is_shared_ && free_on_destruct_) {
     // Only do per-isolate accounting for non-shared backing stores.
     reinterpret_cast<v8::Isolate*>(isolate)
         ->AdjustAmountOfExternalAllocatedMemory(new_length - old_length);
@@ -525,7 +536,8 @@ std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
                                  false,              // is_wasm_memory
                                  free_on_destruct,   // free_on_destruct
                                  false,              // has_guard_regions
-                                 false);             // custom_deleter
+                                 false,              // custom_deleter
+                                 false);             // empty_deleter
   result->SetAllocatorFromIsolate(isolate);
   TRACE_BS("BS:wrap   bs=%p mem=%p (length=%zu)\n", result,
            result->buffer_start(), result->byte_length());
@@ -534,8 +546,9 @@ std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
 
 std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
     void* allocation_base, size_t allocation_length,
-    v8::BackingStoreDeleterCallback deleter, void* deleter_data,
+    v8::BackingStore::DeleterCallback deleter, void* deleter_data,
     SharedFlag shared) {
+  bool is_empty_deleter = (deleter == v8::BackingStore::EmptyDeleter);
   auto result = new BackingStore(allocation_base,    // start
                                  allocation_length,  // length
                                  allocation_length,  // capacity
@@ -543,7 +556,8 @@ std::unique_ptr<BackingStore> BackingStore::WrapAllocation(
                                  false,              // is_wasm_memory
                                  true,               // free_on_destruct
                                  false,              // has_guard_regions
-                                 true);              // custom_deleter
+                                 true,               // custom_deleter
+                                 is_empty_deleter);  // empty_deleter
   result->type_specific_data_.deleter = {deleter, deleter_data};
   TRACE_BS("BS:wrap   bs=%p mem=%p (length=%zu)\n", result,
            result->buffer_start(), result->byte_length());
@@ -559,11 +573,27 @@ std::unique_ptr<BackingStore> BackingStore::EmptyBackingStore(
                                  false,    // is_wasm_memory
                                  true,     // free_on_destruct
                                  false,    // has_guard_regions
-                                 false);   // custom_deleter
+                                 false,    // custom_deleter
+                                 false);   // empty_deleter
 
   return std::unique_ptr<BackingStore>(result);
 }
 
+bool BackingStore::Reallocate(Isolate* isolate, size_t new_byte_length) {
+  CHECK(!is_wasm_memory_ && !custom_deleter_ && !globally_registered_ &&
+        free_on_destruct_);
+  auto allocator = get_v8_api_array_buffer_allocator();
+  CHECK_EQ(isolate->array_buffer_allocator(), allocator);
+  CHECK_EQ(byte_length_, byte_capacity_);
+  void* new_start =
+      allocator->Reallocate(buffer_start_, byte_length_, new_byte_length);
+  if (!new_start) return false;
+  buffer_start_ = new_start;
+  byte_capacity_ = new_byte_length;
+  byte_length_ = new_byte_length;
+  return true;
+}
+
 v8::ArrayBuffer::Allocator* BackingStore::get_v8_api_array_buffer_allocator() {
   CHECK(!is_wasm_memory_);
   auto array_buffer_allocator =
@@ -605,7 +635,7 @@ void GlobalBackingStoreRegistry::Register(
     // BackingStore per buffer_start() because the destructor of
     // of the BackingStore will be a no-op in that case.
 
-    // All WASM memory has to be registered.
+    // All Wasm memory has to be registered.
     CHECK(!backing_store->is_wasm_memory());
     return;
   }
diff --git a/deps/v8/src/objects/backing-store.h b/deps/v8/src/objects/backing-store.h
index c9bbcf4ba0..e9a7c8ec15 100644
--- a/deps/v8/src/objects/backing-store.h
+++ b/deps/v8/src/objects/backing-store.h
@@ -66,7 +66,7 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
 
   static std::unique_ptr<BackingStore> WrapAllocation(
       void* allocation_base, size_t allocation_length,
-      v8::BackingStoreDeleterCallback deleter, void* deleter_data,
+      v8::BackingStore::DeleterCallback deleter, void* deleter_data,
       SharedFlag shared);
 
   // Create an empty backing store.
@@ -87,6 +87,9 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   bool GrowWasmMemoryInPlace(Isolate* isolate, size_t delta_pages,
                              size_t max_pages);
 
+  // Wrapper around ArrayBuffer::Allocator::Reallocate.
+  bool Reallocate(Isolate* isolate, size_t new_byte_length);
+
   // Allocate a new, larger, backing store for this Wasm memory and copy the
   // contents of this backing store into it.
   std::unique_ptr<BackingStore> CopyWasmMemory(Isolate* isolate,
@@ -117,12 +120,31 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   // Update all shared memory objects in this isolate (after a grow operation).
   static void UpdateSharedWasmMemoryObjects(Isolate* isolate);
 
+  // Returns the size of the external memory owned by this backing store.
+  // It is used for triggering GCs based on the external memory pressure.
+  size_t PerIsolateAccountingLength() {
+    if (is_shared_) {
+      // TODO(titzer): SharedArrayBuffers and shared WasmMemorys cause problems
+      // with accounting for per-isolate external memory. In particular, sharing
+      // the same array buffer or memory multiple times, which happens in stress
+      // tests, can cause overcounting, leading to GC thrashing. Fix with global
+      // accounting?
+      return 0;
+    }
+    if (empty_deleter_) {
+      // The backing store has an empty deleter. Even if the backing store is
+      // freed after GC, it would not free the memory block.
+      return 0;
+    }
+    return byte_length();
+  }
+
  private:
   friend class GlobalBackingStoreRegistry;
 
   BackingStore(void* buffer_start, size_t byte_length, size_t byte_capacity,
                SharedFlag shared, bool is_wasm_memory, bool free_on_destruct,
-               bool has_guard_regions, bool custom_deleter)
+               bool has_guard_regions, bool custom_deleter, bool empty_deleter)
       : buffer_start_(buffer_start),
         byte_length_(byte_length),
         byte_capacity_(byte_capacity),
@@ -132,7 +154,8 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
         free_on_destruct_(free_on_destruct),
         has_guard_regions_(has_guard_regions),
         globally_registered_(false),
-        custom_deleter_(custom_deleter) {}
+        custom_deleter_(custom_deleter),
+        empty_deleter_(empty_deleter) {}
   void SetAllocatorFromIsolate(Isolate* isolate);
 
   void* buffer_start_ = nullptr;
@@ -140,7 +163,7 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   size_t byte_capacity_ = 0;
 
   struct DeleterInfo {
-    v8::BackingStoreDeleterCallback callback;
+    v8::BackingStore::DeleterCallback callback;
     void* data;
   };
 
@@ -175,6 +198,7 @@ class V8_EXPORT_PRIVATE BackingStore : public BackingStoreBase {
   bool has_guard_regions_ : 1;
   bool globally_registered_ : 1;
   bool custom_deleter_ : 1;
+  bool empty_deleter_ : 1;
 
   // Accessors for type-specific data.
   v8::ArrayBuffer::Allocator* get_v8_api_array_buffer_allocator();
diff --git a/deps/v8/src/objects/bigint.cc b/deps/v8/src/objects/bigint.cc
index a84cf08f02..dfc302e77c 100644
--- a/deps/v8/src/objects/bigint.cc
+++ b/deps/v8/src/objects/bigint.cc
@@ -20,6 +20,7 @@
 #include "src/objects/bigint.h"
 
 #include "src/execution/isolate-inl.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/heap/factory.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/numbers/conversions.h"
@@ -44,22 +45,28 @@ class MutableBigInt : public FreshlyAllocatedBigInt {
  public:
   // Bottleneck for converting MutableBigInts to BigInts.
   static MaybeHandle<BigInt> MakeImmutable(MaybeHandle<MutableBigInt> maybe);
+  template <typename Isolate = v8::internal::Isolate>
   static Handle<BigInt> MakeImmutable(Handle<MutableBigInt> result);
 
   static void Canonicalize(MutableBigInt result);
 
   // Allocation helpers.
+  template <typename LocalIsolate>
   static MaybeHandle<MutableBigInt> New(
-      Isolate* isolate, int length,
+      LocalIsolate* isolate, int length,
       AllocationType allocation = AllocationType::kYoung);
   static Handle<BigInt> NewFromInt(Isolate* isolate, int value);
   static Handle<BigInt> NewFromDouble(Isolate* isolate, double value);
   void InitializeDigits(int length, byte value = 0);
   static Handle<MutableBigInt> Copy(Isolate* isolate,
                                     Handle<BigIntBase> source);
-  static Handle<BigInt> Zero(Isolate* isolate) {
+  template <typename LocalIsolate>
+  static Handle<BigInt> Zero(
+      LocalIsolate* isolate,
+      AllocationType allocation = AllocationType::kYoung) {
     // TODO(jkummerow): Consider caching a canonical zero-BigInt.
-    return MakeImmutable(New(isolate, 0)).ToHandleChecked();
+    return MakeImmutable<LocalIsolate>(
+        New(isolate, 0, allocation).ToHandleChecked());
   }
 
   static Handle<MutableBigInt> Cast(Handle<FreshlyAllocatedBigInt> bigint) {
@@ -236,7 +243,7 @@ NEVER_READ_ONLY_SPACE_IMPL(MutableBigInt)
 
 #include "src/objects/object-macros-undef.h"
 
-template <typename T>
+template <typename T, typename Isolate>
 MaybeHandle<T> ThrowBigIntTooBig(Isolate* isolate) {
   // If the result of a BigInt computation is truncated to 64 bit, Turbofan
   // can sometimes truncate intermediate results already, which can prevent
@@ -250,7 +257,8 @@ MaybeHandle<T> ThrowBigIntTooBig(Isolate* isolate) {
   THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kBigIntTooBig), T);
 }
 
-MaybeHandle<MutableBigInt> MutableBigInt::New(Isolate* isolate, int length,
+template <typename LocalIsolate>
+MaybeHandle<MutableBigInt> MutableBigInt::New(LocalIsolate* isolate, int length,
                                               AllocationType allocation) {
   if (length > BigInt::kMaxLength) {
     return ThrowBigIntTooBig<MutableBigInt>(isolate);
@@ -372,6 +380,7 @@ MaybeHandle<BigInt> MutableBigInt::MakeImmutable(
   return MakeImmutable(result);
 }
 
+template <typename LocalIsolate>
 Handle<BigInt> MutableBigInt::MakeImmutable(Handle<MutableBigInt> result) {
   MutableBigInt::Canonicalize(*result);
   return Handle<BigInt>::cast(result);
@@ -405,9 +414,14 @@ void MutableBigInt::Canonicalize(MutableBigInt result) {
                  result.digit(result.length() - 1) != 0);  // MSD is non-zero.
 }
 
-Handle<BigInt> BigInt::Zero(Isolate* isolate) {
-  return MutableBigInt::Zero(isolate);
+template <typename LocalIsolate>
+Handle<BigInt> BigInt::Zero(LocalIsolate* isolate, AllocationType allocation) {
+  return MutableBigInt::Zero(isolate, allocation);
 }
+template Handle<BigInt> BigInt::Zero<Isolate>(Isolate* isolate,
+                                              AllocationType allocation);
+template Handle<BigInt> BigInt::Zero<OffThreadIsolate>(
+    OffThreadIsolate* isolate, AllocationType allocation);
 
 Handle<BigInt> BigInt::UnaryMinus(Isolate* isolate, Handle<BigInt> x) {
   // Special case: There is no -0n.
@@ -1505,13 +1519,13 @@ void MutableBigInt::InternalMultiplyAdd(BigIntBase source, digit_t factor,
 }
 
 // Multiplies {x} with {factor} and then adds {summand} to it.
-void BigInt::InplaceMultiplyAdd(Handle<FreshlyAllocatedBigInt> x,
-                                uintptr_t factor, uintptr_t summand) {
+void BigInt::InplaceMultiplyAdd(FreshlyAllocatedBigInt x, uintptr_t factor,
+                                uintptr_t summand) {
   STATIC_ASSERT(sizeof(factor) == sizeof(digit_t));
   STATIC_ASSERT(sizeof(summand) == sizeof(digit_t));
-  Handle<MutableBigInt> bigint = MutableBigInt::Cast(x);
-  MutableBigInt::InternalMultiplyAdd(*bigint, factor, summand, bigint->length(),
-                                     *bigint);
+  MutableBigInt bigint = MutableBigInt::cast(x);
+  MutableBigInt::InternalMultiplyAdd(bigint, factor, summand, bigint.length(),
+                                     bigint);
 }
 
 // Divides {x} by {divisor}, returning the result in {quotient} and {remainder}.
@@ -1907,8 +1921,9 @@ constexpr uint8_t kMaxBitsPerChar[] = {
 static const int kBitsPerCharTableShift = 5;
 static const size_t kBitsPerCharTableMultiplier = 1u << kBitsPerCharTableShift;
 
+template <typename LocalIsolate>
 MaybeHandle<FreshlyAllocatedBigInt> BigInt::AllocateFor(
-    Isolate* isolate, int radix, int charcount, ShouldThrow should_throw,
+    LocalIsolate* isolate, int radix, int charcount, ShouldThrow should_throw,
     AllocationType allocation) {
   DCHECK(2 <= radix && radix <= 36);
   DCHECK_GE(charcount, 0);
@@ -1937,13 +1952,26 @@ MaybeHandle<FreshlyAllocatedBigInt> BigInt::AllocateFor(
     return MaybeHandle<FreshlyAllocatedBigInt>();
   }
 }
+template MaybeHandle<FreshlyAllocatedBigInt> BigInt::AllocateFor<Isolate>(
+    Isolate* isolate, int radix, int charcount, ShouldThrow should_throw,
+    AllocationType allocation);
+template MaybeHandle<FreshlyAllocatedBigInt>
+BigInt::AllocateFor<OffThreadIsolate>(OffThreadIsolate* isolate, int radix,
+                                      int charcount, ShouldThrow should_throw,
+                                      AllocationType allocation);
 
+template <typename LocalIsolate>
 Handle<BigInt> BigInt::Finalize(Handle<FreshlyAllocatedBigInt> x, bool sign) {
-  Handle<MutableBigInt> bigint = MutableBigInt::Cast(x);
+  Handle<MutableBigInt> bigint = Handle<MutableBigInt>::cast(x);
   bigint->set_sign(sign);
-  return MutableBigInt::MakeImmutable(bigint);
+  return MutableBigInt::MakeImmutable<Isolate>(bigint);
 }
 
+template Handle<BigInt> BigInt::Finalize<Isolate>(
+    Handle<FreshlyAllocatedBigInt>, bool);
+template Handle<BigInt> BigInt::Finalize<OffThreadIsolate>(
+    Handle<FreshlyAllocatedBigInt>, bool);
+
 // The serialization format MUST NOT CHANGE without updating the format
 // version in value-serializer.cc!
 uint32_t BigInt::GetBitfieldForSerialization() const {
diff --git a/deps/v8/src/objects/bigint.h b/deps/v8/src/objects/bigint.h
index 2247c157a8..ccdbf33f61 100644
--- a/deps/v8/src/objects/bigint.h
+++ b/deps/v8/src/objects/bigint.h
@@ -238,17 +238,22 @@ class BigInt : public BigIntBase {
   class BodyDescriptor;
 
  private:
+  template <typename LocalIsolate>
   friend class StringToBigIntHelper;
   friend class ValueDeserializer;
   friend class ValueSerializer;
 
   // Special functions for StringToBigIntHelper:
-  static Handle<BigInt> Zero(Isolate* isolate);
+  template <typename LocalIsolate>
+  static Handle<BigInt> Zero(LocalIsolate* isolate, AllocationType allocation =
+                                                        AllocationType::kYoung);
+  template <typename LocalIsolate>
   static MaybeHandle<FreshlyAllocatedBigInt> AllocateFor(
-      Isolate* isolate, int radix, int charcount, ShouldThrow should_throw,
+      LocalIsolate* isolate, int radix, int charcount, ShouldThrow should_throw,
       AllocationType allocation);
-  static void InplaceMultiplyAdd(Handle<FreshlyAllocatedBigInt> x,
-                                 uintptr_t factor, uintptr_t summand);
+  static void InplaceMultiplyAdd(FreshlyAllocatedBigInt x, uintptr_t factor,
+                                 uintptr_t summand);
+  template <typename LocalIsolate>
   static Handle<BigInt> Finalize(Handle<FreshlyAllocatedBigInt> x, bool sign);
 
   // Special functions for ValueSerializer/ValueDeserializer:
diff --git a/deps/v8/src/objects/code-inl.h b/deps/v8/src/objects/code-inl.h
index d02ead4bbe..81db1745c4 100644
--- a/deps/v8/src/objects/code-inl.h
+++ b/deps/v8/src/objects/code-inl.h
@@ -733,6 +733,7 @@ DEFINE_DEOPT_ELEMENT_ACCESSORS(OsrPcOffset, Smi)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(OptimizationId, Smi)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(InliningPositions, PodArray<InliningPosition>)
 DEFINE_DEOPT_ELEMENT_ACCESSORS(DeoptExitStart, Smi)
+DEFINE_DEOPT_ELEMENT_ACCESSORS(NonLazyDeoptCount, Smi)
 
 DEFINE_DEOPT_ENTRY_ACCESSORS(BytecodeOffsetRaw, Smi)
 DEFINE_DEOPT_ENTRY_ACCESSORS(TranslationIndex, Smi)
diff --git a/deps/v8/src/objects/code.cc b/deps/v8/src/objects/code.cc
index 7f650bebfb..4f272f1299 100644
--- a/deps/v8/src/objects/code.cc
+++ b/deps/v8/src/objects/code.cc
@@ -4,6 +4,7 @@
 
 #include <iomanip>
 
+#include "src/execution/isolate-utils.h"
 #include "src/objects/code.h"
 
 #include "src/codegen/assembler-inl.h"
@@ -159,10 +160,12 @@ int AbstractCode::SourcePosition(int offset) {
   if (maybe_table.IsException()) return kNoSourcePosition;
 
   ByteArray source_position_table = ByteArray::cast(maybe_table);
-  int position = 0;
   // Subtract one because the current PC is one instruction after the call site.
   if (IsCode()) offset--;
-  for (SourcePositionTableIterator iterator(source_position_table);
+  int position = 0;
+  for (SourcePositionTableIterator iterator(
+           source_position_table, SourcePositionTableIterator::kJavaScriptOnly,
+           SourcePositionTableIterator::kDontSkipFunctionEntry);
        !iterator.done() && iterator.code_offset() <= offset;
        iterator.Advance()) {
     position = iterator.source_position().ScriptOffset();
@@ -961,14 +964,14 @@ bool DependentCode::Compact() {
 }
 
 bool DependentCode::MarkCodeForDeoptimization(
-    Isolate* isolate, DependentCode::DependencyGroup group) {
+    DependentCode::DependencyGroup group) {
   if (this->length() == 0 || this->group() > group) {
     // There is no such group.
     return false;
   }
   if (this->group() < group) {
     // The group comes later in the list.
-    return next_link().MarkCodeForDeoptimization(isolate, group);
+    return next_link().MarkCodeForDeoptimization(group);
   }
   DCHECK_EQ(group, this->group());
   DisallowHeapAllocation no_allocation_scope;
@@ -992,12 +995,12 @@ bool DependentCode::MarkCodeForDeoptimization(
 }
 
 void DependentCode::DeoptimizeDependentCodeGroup(
-    Isolate* isolate, DependentCode::DependencyGroup group) {
+    DependentCode::DependencyGroup group) {
   DisallowHeapAllocation no_allocation_scope;
-  bool marked = MarkCodeForDeoptimization(isolate, group);
+  bool marked = MarkCodeForDeoptimization(group);
   if (marked) {
     DCHECK(AllowCodeDependencyChange::IsAllowed());
-    Deoptimizer::DeoptimizeMarkedCode(isolate);
+    Deoptimizer::DeoptimizeMarkedCode(GetIsolateFromWritableObject(*this));
   }
 }
 
diff --git a/deps/v8/src/objects/code.h b/deps/v8/src/objects/code.h
index 3e8de6877d..d80e72fa03 100644
--- a/deps/v8/src/objects/code.h
+++ b/deps/v8/src/objects/code.h
@@ -424,7 +424,7 @@ class Code : public HeapObject {
   static constexpr int kHeaderPaddingSize =
       FLAG_enable_embedded_constant_pool ? 28 : 0;
 #elif V8_TARGET_ARCH_S390X
-  static constexpr int kHeaderPaddingSize = 0;
+  static constexpr int kHeaderPaddingSize = COMPRESS_POINTERS_BOOL ? 20 : 0;
 #else
 #error Unknown architecture.
 #endif
@@ -659,9 +659,9 @@ class DependentCode : public WeakFixedArray {
                                                   Handle<HeapObject> object,
                                                   DependencyGroup group);
 
-  void DeoptimizeDependentCodeGroup(Isolate* isolate, DependencyGroup group);
+  void DeoptimizeDependentCodeGroup(DependencyGroup group);
 
-  bool MarkCodeForDeoptimization(Isolate* isolate, DependencyGroup group);
+  bool MarkCodeForDeoptimization(DependencyGroup group);
 
   // The following low-level accessors are exposed only for tests.
   inline DependencyGroup group();
@@ -864,7 +864,8 @@ class DeoptimizationData : public FixedArray {
   static const int kSharedFunctionInfoIndex = 6;
   static const int kInliningPositionsIndex = 7;
   static const int kDeoptExitStartIndex = 8;
-  static const int kFirstDeoptEntryIndex = 9;
+  static const int kNonLazyDeoptCountIndex = 9;
+  static const int kFirstDeoptEntryIndex = 10;
 
   // Offsets of deopt entry elements relative to the start of the entry.
   static const int kBytecodeOffsetRawOffset = 0;
@@ -886,6 +887,7 @@ class DeoptimizationData : public FixedArray {
   DECL_ELEMENT_ACCESSORS(SharedFunctionInfo, Object)
   DECL_ELEMENT_ACCESSORS(InliningPositions, PodArray<InliningPosition>)
   DECL_ELEMENT_ACCESSORS(DeoptExitStart, Smi)
+  DECL_ELEMENT_ACCESSORS(NonLazyDeoptCount, Smi)
 
 #undef DECL_ELEMENT_ACCESSORS
 
diff --git a/deps/v8/src/objects/compilation-cache.h b/deps/v8/src/objects/compilation-cache.h
index 2072339c5e..dd507f3c2d 100644
--- a/deps/v8/src/objects/compilation-cache.h
+++ b/deps/v8/src/objects/compilation-cache.h
@@ -23,7 +23,7 @@ class CompilationCacheShape : public BaseShape<HashTableKey*> {
     return key->IsMatch(value);
   }
 
-  static inline uint32_t Hash(Isolate* isolate, HashTableKey* key) {
+  static inline uint32_t Hash(ReadOnlyRoots roots, HashTableKey* key) {
     return key->Hash();
   }
 
@@ -70,6 +70,8 @@ class InfoCellPair {
   FeedbackCell feedback_cell_;
 };
 
+EXTERN_DECLARE_HASH_TABLE(CompilationCacheTable, CompilationCacheShape)
+
 // This cache is used in two different variants. For regexp caching, it simply
 // maps identifying info of the regexp to the cached regexp object. Scripts and
 // eval code only gets cached after a second probe for the code object. To do
diff --git a/deps/v8/src/objects/contexts.cc b/deps/v8/src/objects/contexts.cc
index 5aa8a78953..686a3c689e 100644
--- a/deps/v8/src/objects/contexts.cc
+++ b/deps/v8/src/objects/contexts.cc
@@ -36,6 +36,16 @@ Handle<ScriptContextTable> ScriptContextTable::Extend(
   return result;
 }
 
+void Context::Initialize(Isolate* isolate) {
+  ScopeInfo scope_info = this->scope_info();
+  int header = scope_info.ContextHeaderLength();
+  for (int var = 0; var < scope_info.ContextLocalCount(); var++) {
+    if (scope_info.ContextLocalInitFlag(var) == kNeedsInitialization) {
+      set(header + var, ReadOnlyRoots(isolate).the_hole_value());
+    }
+  }
+}
+
 bool ScriptContextTable::Lookup(Isolate* isolate, ScriptContextTable table,
                                 String name, LookupResult* result) {
   DisallowHeapAllocation no_gc;
diff --git a/deps/v8/src/objects/contexts.h b/deps/v8/src/objects/contexts.h
index 2289cd6210..a273549d96 100644
--- a/deps/v8/src/objects/contexts.h
+++ b/deps/v8/src/objects/contexts.h
@@ -63,6 +63,9 @@ enum ContextLookupFlags {
   /* it's already UBSan-fiendly and doesn't require a star... So declare */    \
   /* it as a HeapObject for now. */                                            \
   V(EMBEDDER_DATA_INDEX, HeapObject, embedder_data)                            \
+  V(CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX, HeapObject,                    \
+    continuation_preserved_embedder_data)                                      \
+  NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V)                                        \
   /* Below is alpha-sorted */                                                  \
   V(ACCESSOR_PROPERTY_DESCRIPTOR_MAP_INDEX, Map,                               \
     accessor_property_descriptor_map)                                          \
@@ -188,13 +191,13 @@ enum ContextLookupFlags {
   V(JS_SET_FUN_INDEX, JSFunction, js_set_fun)                                  \
   V(JS_SET_MAP_INDEX, Map, js_set_map)                                         \
   V(WEAK_CELL_MAP_INDEX, Map, weak_cell_map)                                   \
-  V(JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_MAP_INDEX, Map,                     \
-    js_finalization_group_cleanup_iterator_map)                                \
+  V(JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_MAP_INDEX, Map,                  \
+    js_finalization_registry_cleanup_iterator_map)                             \
   V(JS_WEAK_MAP_FUN_INDEX, JSFunction, js_weak_map_fun)                        \
   V(JS_WEAK_SET_FUN_INDEX, JSFunction, js_weak_set_fun)                        \
   V(JS_WEAK_REF_FUNCTION_INDEX, JSFunction, js_weak_ref_fun)                   \
-  V(JS_FINALIZATION_GROUP_FUNCTION_INDEX, JSFunction,                          \
-    js_finalization_group_fun)                                                 \
+  V(JS_FINALIZATION_REGISTRY_FUNCTION_INDEX, JSFunction,                       \
+    js_finalization_registry_fun)                                              \
   /* Context maps */                                                           \
   V(NATIVE_CONTEXT_MAP_INDEX, Map, native_context_map)                         \
   V(FUNCTION_CONTEXT_MAP_INDEX, Map, function_context_map)                     \
@@ -348,6 +351,7 @@ enum ContextLookupFlags {
   V(MAP_SET_INDEX, JSFunction, map_set)                                        \
   V(FUNCTION_HAS_INSTANCE_INDEX, JSFunction, function_has_instance)            \
   V(OBJECT_TO_STRING, JSFunction, object_to_string)                            \
+  V(OBJECT_VALUE_OF_FUNCTION_INDEX, JSFunction, object_value_of_function)      \
   V(PROMISE_ALL_INDEX, JSFunction, promise_all)                                \
   V(PROMISE_CATCH_INDEX, JSFunction, promise_catch)                            \
   V(PROMISE_FUNCTION_INDEX, JSFunction, promise_function)                      \
@@ -367,8 +371,7 @@ enum ContextLookupFlags {
   V(WEAKMAP_SET_INDEX, JSFunction, weakmap_set)                                \
   V(WEAKMAP_GET_INDEX, JSFunction, weakmap_get)                                \
   V(WEAKSET_ADD_INDEX, JSFunction, weakset_add)                                \
-  V(OSR_CODE_CACHE_INDEX, WeakFixedArray, osr_code_cache)                      \
-  NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V)
+  V(OSR_CODE_CACHE_INDEX, WeakFixedArray, osr_code_cache)
 
 // A table of all script contexts. Every loaded top-level script with top-level
 // lexical declarations contributes its ScriptContext into this table.
@@ -507,6 +510,10 @@ class Context : public HeapObject {
     return SizeFor(index) - kHeapObjectTag;
   }
 
+  // Initializes the variable slots of the context. Lexical variables that need
+  // initialization are filled with the hole.
+  void Initialize(Isolate* isolate);
+
   // TODO(ishell): eventually migrate to the offset based access instead of
   // index-based.
   // The default context slot layout; indices are FixedArray slot indices.
@@ -679,8 +686,6 @@ class Context : public HeapObject {
 #endif
 
   OBJECT_CONSTRUCTORS(Context, HeapObject);
-  DECL_INT_ACCESSORS(length_and_extension_flag)
-  DECL_SYNCHRONIZED_INT_ACCESSORS(length_and_extension_flag)
 };
 
 class NativeContext : public Context {
diff --git a/deps/v8/src/objects/contexts.tq b/deps/v8/src/objects/contexts.tq
index 5af3011d51..6def2320ff 100644
--- a/deps/v8/src/objects/contexts.tq
+++ b/deps/v8/src/objects/contexts.tq
@@ -59,6 +59,8 @@ extern enum NativeContextSlot extends intptr constexpr 'Context::Field' {
   PROMISE_THEN_FINALLY_SHARED_FUN,
   PROMISE_VALUE_THUNK_FINALLY_SHARED_FUN,
   STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX,
+
+  CONTINUATION_PRESERVED_EMBEDDER_DATA_INDEX,
   ...
 }
 
diff --git a/deps/v8/src/objects/debug-objects-inl.h b/deps/v8/src/objects/debug-objects-inl.h
index 6a0dc76f64..c5b024ed1d 100644
--- a/deps/v8/src/objects/debug-objects-inl.h
+++ b/deps/v8/src/objects/debug-objects-inl.h
@@ -20,16 +20,11 @@ namespace internal {
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(BreakPoint)
 TQ_OBJECT_CONSTRUCTORS_IMPL(BreakPointInfo)
-OBJECT_CONSTRUCTORS_IMPL(CoverageInfo, FixedArray)
+TQ_OBJECT_CONSTRUCTORS_IMPL(CoverageInfo)
 TQ_OBJECT_CONSTRUCTORS_IMPL(DebugInfo)
 
 NEVER_READ_ONLY_SPACE_IMPL(DebugInfo)
 
-CAST_ACCESSOR(CoverageInfo)
-
-TQ_SMI_ACCESSORS(DebugInfo, flags)
-TQ_SMI_ACCESSORS(DebugInfo, debugger_hints)
-
 BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, side_effect_state,
                     DebugInfo::SideEffectStateBits)
 BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, debug_is_blackboxed,
@@ -39,10 +34,6 @@ BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, computed_debug_is_blackboxed,
 BIT_FIELD_ACCESSORS(DebugInfo, debugger_hints, debugging_id,
                     DebugInfo::DebuggingIdBits)
 
-TQ_SMI_ACCESSORS(BreakPointInfo, source_position)
-
-TQ_SMI_ACCESSORS(BreakPoint, id)
-
 bool DebugInfo::HasInstrumentedBytecodeArray() {
   DCHECK_EQ(debug_bytecode_array().IsBytecodeArray(),
             original_bytecode_array().IsBytecodeArray());
diff --git a/deps/v8/src/objects/debug-objects.cc b/deps/v8/src/objects/debug-objects.cc
index 3f7f55f852..48dc2d5b8d 100644
--- a/deps/v8/src/objects/debug-objects.cc
+++ b/deps/v8/src/objects/debug-objects.cc
@@ -357,64 +357,56 @@ int BreakPointInfo::GetBreakPointCount(Isolate* isolate) {
   return FixedArray::cast(break_points()).length();
 }
 
-int CoverageInfo::SlotCount() const {
-  DCHECK_EQ(kFirstSlotIndex, length() % kSlotIndexCount);
-  return (length() - kFirstSlotIndex) / kSlotIndexCount;
+int CoverageInfo::SlotFieldOffset(int slot_index, int field_offset) const {
+  DCHECK_LT(field_offset, Slot::kSize);
+  DCHECK_LT(slot_index, slot_count());
+  return kSlotsOffset + slot_index * Slot::kSize + field_offset;
 }
 
 int CoverageInfo::StartSourcePosition(int slot_index) const {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  return Smi::ToInt(get(slot_start + kSlotStartSourcePositionIndex));
+  return ReadField<int32_t>(
+      SlotFieldOffset(slot_index, Slot::kStartSourcePositionOffset));
 }
 
 int CoverageInfo::EndSourcePosition(int slot_index) const {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  return Smi::ToInt(get(slot_start + kSlotEndSourcePositionIndex));
+  return ReadField<int32_t>(
+      SlotFieldOffset(slot_index, Slot::kEndSourcePositionOffset));
 }
 
 int CoverageInfo::BlockCount(int slot_index) const {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  return Smi::ToInt(get(slot_start + kSlotBlockCountIndex));
+  return ReadField<int32_t>(
+      SlotFieldOffset(slot_index, Slot::kBlockCountOffset));
 }
 
 void CoverageInfo::InitializeSlot(int slot_index, int from_pos, int to_pos) {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  set(slot_start + kSlotStartSourcePositionIndex, Smi::FromInt(from_pos));
-  set(slot_start + kSlotEndSourcePositionIndex, Smi::FromInt(to_pos));
-  set(slot_start + kSlotBlockCountIndex, Smi::zero());
-}
-
-void CoverageInfo::IncrementBlockCount(int slot_index) {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  const int old_count = BlockCount(slot_index);
-  set(slot_start + kSlotBlockCountIndex, Smi::FromInt(old_count + 1));
+  WriteField<int32_t>(
+      SlotFieldOffset(slot_index, Slot::kStartSourcePositionOffset), from_pos);
+  WriteField<int32_t>(
+      SlotFieldOffset(slot_index, Slot::kEndSourcePositionOffset), to_pos);
+  ResetBlockCount(slot_index);
+  WriteField<int32_t>(SlotFieldOffset(slot_index, Slot::kPaddingOffset), 0);
 }
 
 void CoverageInfo::ResetBlockCount(int slot_index) {
-  DCHECK_LT(slot_index, SlotCount());
-  const int slot_start = CoverageInfo::FirstIndexForSlot(slot_index);
-  set(slot_start + kSlotBlockCountIndex, Smi::zero());
+  WriteField<int32_t>(SlotFieldOffset(slot_index, Slot::kBlockCountOffset), 0);
 }
 
-void CoverageInfo::Print(std::unique_ptr<char[]> function_name) {
+void CoverageInfo::CoverageInfoPrint(std::ostream& os,
+                                     std::unique_ptr<char[]> function_name) {
   DCHECK(FLAG_trace_block_coverage);
   DisallowHeapAllocation no_gc;
 
-  StdoutStream os;
   os << "Coverage info (";
-  if (strlen(function_name.get()) > 0) {
+  if (function_name == nullptr) {
+    os << "{unknown}";
+  } else if (strlen(function_name.get()) > 0) {
     os << function_name.get();
   } else {
     os << "{anonymous}";
   }
   os << "):" << std::endl;
 
-  for (int i = 0; i < SlotCount(); i++) {
+  for (int i = 0; i < slot_count(); i++) {
     os << "{" << StartSourcePosition(i) << "," << EndSourcePosition(i) << "}"
        << std::endl;
   }
diff --git a/deps/v8/src/objects/debug-objects.h b/deps/v8/src/objects/debug-objects.h
index 321ac11cda..a7ce9ec367 100644
--- a/deps/v8/src/objects/debug-objects.h
+++ b/deps/v8/src/objects/debug-objects.h
@@ -11,6 +11,7 @@
 #include "src/objects/fixed-array.h"
 #include "src/objects/objects.h"
 #include "src/objects/struct.h"
+#include "torque-generated/bit-fields-tq.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -26,24 +27,9 @@ class BytecodeArray;
 class DebugInfo : public TorqueGeneratedDebugInfo<DebugInfo, Struct> {
  public:
   NEVER_READ_ONLY_SPACE
-  enum Flag {
-    kNone = 0,
-    kHasBreakInfo = 1 << 0,
-    kPreparedForDebugExecution = 1 << 1,
-    kHasCoverageInfo = 1 << 2,
-    kBreakAtEntry = 1 << 3,
-    kCanBreakAtEntry = 1 << 4,
-    kDebugExecutionMode = 1 << 5
-  };
-
+  DEFINE_TORQUE_GENERATED_DEBUG_INFO_FLAGS()
   using Flags = base::Flags<Flag>;
 
-  // A bitfield that lists uses of the current instance.
-  DECL_INT_ACCESSORS(flags)
-
-  // Bit field containing various information collected for debugging.
-  DECL_INT_ACCESSORS(debugger_hints)
-
   // DebugInfo can be detached from the SharedFunctionInfo iff it is empty.
   bool IsEmpty() const;
 
@@ -127,15 +113,8 @@ class DebugInfo : public TorqueGeneratedDebugInfo<DebugInfo, Struct> {
   // This could also be implemented as a weak hash table.
   DECL_INT_ACCESSORS(debugging_id)
 
-// Bit positions in |debugger_hints|.
-#define DEBUGGER_HINTS_BIT_FIELDS(V, _)       \
-  V(SideEffectStateBits, int, 2, _)           \
-  V(DebugIsBlackboxedBit, bool, 1, _)         \
-  V(ComputedDebugIsBlackboxedBit, bool, 1, _) \
-  V(DebuggingIdBits, int, 20, _)
-
-  DEFINE_BIT_FIELDS(DEBUGGER_HINTS_BIT_FIELDS)
-#undef DEBUGGER_HINTS_BIT_FIELDS
+  // Bit positions in |debugger_hints|.
+  DEFINE_TORQUE_GENERATED_DEBUGGER_HINTS()
 
   static const int kNoDebuggingId = 0;
 
@@ -165,9 +144,6 @@ class DebugInfo : public TorqueGeneratedDebugInfo<DebugInfo, Struct> {
 class BreakPointInfo
     : public TorqueGeneratedBreakPointInfo<BreakPointInfo, Struct> {
  public:
-  // The position in the source for the break position.
-  DECL_INT_ACCESSORS(source_position)
-
   // Removes a break point.
   static void ClearBreakPoint(Isolate* isolate, Handle<BreakPointInfo> info,
                               Handle<BreakPoint> break_point);
@@ -190,54 +166,39 @@ class BreakPointInfo
 };
 
 // Holds information related to block code coverage.
-class CoverageInfo : public FixedArray {
+class CoverageInfo
+    : public TorqueGeneratedCoverageInfo<CoverageInfo, HeapObject> {
  public:
-  int SlotCount() const;
-
   int StartSourcePosition(int slot_index) const;
   int EndSourcePosition(int slot_index) const;
   int BlockCount(int slot_index) const;
 
   void InitializeSlot(int slot_index, int start_pos, int end_pos);
-  void IncrementBlockCount(int slot_index);
   void ResetBlockCount(int slot_index);
 
-  static int FixedArrayLengthForSlotCount(int slot_count) {
-    return slot_count * kSlotIndexCount + kFirstSlotIndex;
+  // Computes the size for a CoverageInfo instance of a given length.
+  static int SizeFor(int slot_count) {
+    return OBJECT_POINTER_ALIGN(kHeaderSize + slot_count * Slot::kSize);
   }
 
-  DECL_CAST(CoverageInfo)
-
   // Print debug info.
-  void Print(std::unique_ptr<char[]> function_name);
-
-  static const int kFirstSlotIndex = 0;
+  void CoverageInfoPrint(std::ostream& os,
+                         std::unique_ptr<char[]> function_name = nullptr);
 
-  // Each slot is assigned a group of indices starting at kFirstSlotIndex.
-  // Within this group, semantics are as follows:
-  static const int kSlotStartSourcePositionIndex = 0;
-  static const int kSlotEndSourcePositionIndex = 1;
-  static const int kSlotBlockCountIndex = 2;
-  static const int kSlotPaddingIndex = 3;  // Padding to make the index count 4.
-  static const int kSlotIndexCount = 4;
+  class BodyDescriptor;  // GC visitor.
 
-  static const int kSlotIndexCountLog2 = 2;
-  static const int kSlotIndexCountMask = (kSlotIndexCount - 1);
-  STATIC_ASSERT(1 << kSlotIndexCountLog2 == kSlotIndexCount);
+  // Description of layout within each slot.
+  using Slot = TorqueGeneratedCoverageInfoSlotOffsets;
 
  private:
-  static int FirstIndexForSlot(int slot_index) {
-    return kFirstSlotIndex + slot_index * kSlotIndexCount;
-  }
+  int SlotFieldOffset(int slot_index, int field_offset) const;
 
-  OBJECT_CONSTRUCTORS(CoverageInfo, FixedArray);
+  TQ_OBJECT_CONSTRUCTORS(CoverageInfo)
 };
 
 // Holds breakpoint related information. This object is used by inspector.
 class BreakPoint : public TorqueGeneratedBreakPoint<BreakPoint, Struct> {
  public:
-  DECL_INT_ACCESSORS(id)
-
   TQ_OBJECT_CONSTRUCTORS(BreakPoint)
 };
 
diff --git a/deps/v8/src/objects/debug-objects.tq b/deps/v8/src/objects/debug-objects.tq
index fb52af5a51..d50d86c482 100644
--- a/deps/v8/src/objects/debug-objects.tq
+++ b/deps/v8/src/objects/debug-objects.tq
@@ -18,12 +18,27 @@ extern class BreakPointInfo extends Struct {
   break_points: FixedArray|BreakPoint|Undefined;
 }
 
-type CoverageInfo extends FixedArray;
+bitfield struct DebugInfoFlags extends uint31 {
+  has_break_info: bool: 1 bit;
+  prepared_for_debug_execution: bool: 1 bit;
+  has_coverage_info: bool: 1 bit;
+  break_at_entry: bool: 1 bit;
+  can_break_at_entry: bool: 1 bit;
+  debug_execution_mode: bool: 1 bit;
+}
+
+bitfield struct DebuggerHints extends uint31 {
+  side_effect_state: int32: 2 bit;
+  debug_is_blackboxed: bool: 1 bit;
+  computed_debug_is_blackboxed: bool: 1 bit;
+  debugging_id: int32: 20 bit;
+}
 
 @generateCppClass
 extern class DebugInfo extends Struct {
   shared: SharedFunctionInfo;
-  debugger_hints: Smi;
+  // Bit field containing various information collected for debugging.
+  debugger_hints: SmiTagged<DebuggerHints>;
   // Script field from shared function info.
   script: Undefined|Script;
   // The original uninstrumented bytecode array for functions with break
@@ -34,6 +49,23 @@ extern class DebugInfo extends Struct {
   debug_bytecode_array: Undefined|BytecodeArray;
   // Fixed array holding status information for each active break point.
   break_points: FixedArray;
-  flags: Smi;
+  // A bitfield that lists uses of the current instance.
+  flags: SmiTagged<DebugInfoFlags>;
   coverage_info: CoverageInfo|Undefined;
 }
+
+@export
+struct CoverageInfoSlot {
+  start_source_position: int32;
+  end_source_position: int32;
+  block_count: int32;
+  padding: int32;  // Padding to make the index count 4.
+}
+
+// CoverageInfo's visitor is included in DATA_ONLY_VISITOR_ID_LIST, so it must
+// not contain any HeapObject fields.
+@generateCppClass
+extern class CoverageInfo extends HeapObject {
+  const slot_count: int32;
+  slots[slot_count]: CoverageInfoSlot;
+}
diff --git a/deps/v8/src/objects/descriptor-array.h b/deps/v8/src/objects/descriptor-array.h
index 0085a1d78d..e24673d01c 100644
--- a/deps/v8/src/objects/descriptor-array.h
+++ b/deps/v8/src/objects/descriptor-array.h
@@ -5,6 +5,7 @@
 #ifndef V8_OBJECTS_DESCRIPTOR_ARRAY_H_
 #define V8_OBJECTS_DESCRIPTOR_ARRAY_H_
 
+#include "src/common/globals.h"
 #include "src/objects/fixed-array.h"
 // TODO(jkummerow): Consider forward-declaring instead.
 #include "src/base/bit-field.h"
@@ -126,9 +127,10 @@ class DescriptorArray : public HeapObject {
 
   // Allocates a DescriptorArray, but returns the singleton
   // empty descriptor array object if number_of_descriptors is 0.
-  V8_EXPORT_PRIVATE static Handle<DescriptorArray> Allocate(Isolate* isolate,
-                                                            int nof_descriptors,
-                                                            int slack);
+  template <typename LocalIsolate>
+  V8_EXPORT_PRIVATE static Handle<DescriptorArray> Allocate(
+      LocalIsolate* isolate, int nof_descriptors, int slack,
+      AllocationType allocation = AllocationType::kYoung);
 
   void Initialize(EnumCache enum_cache, HeapObject undefined_value,
                   int nof_descriptors, int slack);
diff --git a/deps/v8/src/objects/descriptor-array.tq b/deps/v8/src/objects/descriptor-array.tq
index ac512235c0..53c209e237 100644
--- a/deps/v8/src/objects/descriptor-array.tq
+++ b/deps/v8/src/objects/descriptor-array.tq
@@ -17,7 +17,7 @@ struct DescriptorEntry {
 }
 
 extern class DescriptorArray extends HeapObject {
-  number_of_all_descriptors: uint16;
+  const number_of_all_descriptors: uint16;
   number_of_descriptors: uint16;
   raw_number_of_marked_descriptors: uint16;
   filler16_bits: uint16;
diff --git a/deps/v8/src/objects/dictionary-inl.h b/deps/v8/src/objects/dictionary-inl.h
index 965fcb989c..10efd226af 100644
--- a/deps/v8/src/objects/dictionary-inl.h
+++ b/deps/v8/src/objects/dictionary-inl.h
@@ -54,10 +54,9 @@ PropertyDetails Dictionary<Derived, Shape>::DetailsAt(InternalIndex entry) {
 }
 
 template <typename Derived, typename Shape>
-void Dictionary<Derived, Shape>::DetailsAtPut(Isolate* isolate,
-                                              InternalIndex entry,
+void Dictionary<Derived, Shape>::DetailsAtPut(InternalIndex entry,
                                               PropertyDetails value) {
-  Shape::DetailsAtPut(isolate, Derived::cast(*this), entry, value);
+  Shape::DetailsAtPut(Derived::cast(*this), entry, value);
 }
 
 template <typename Derived, typename Shape>
@@ -128,16 +127,15 @@ void NumberDictionary::set_requires_slow_elements() {
 }
 
 template <typename Derived, typename Shape>
-void Dictionary<Derived, Shape>::ClearEntry(Isolate* isolate,
-                                            InternalIndex entry) {
+void Dictionary<Derived, Shape>::ClearEntry(InternalIndex entry) {
   Object the_hole = this->GetReadOnlyRoots().the_hole_value();
   PropertyDetails details = PropertyDetails::Empty();
-  Derived::cast(*this).SetEntry(isolate, entry, the_hole, the_hole, details);
+  Derived::cast(*this).SetEntry(entry, the_hole, the_hole, details);
 }
 
 template <typename Derived, typename Shape>
-void Dictionary<Derived, Shape>::SetEntry(Isolate* isolate, InternalIndex entry,
-                                          Object key, Object value,
+void Dictionary<Derived, Shape>::SetEntry(InternalIndex entry, Object key,
+                                          Object value,
                                           PropertyDetails details) {
   DCHECK(Dictionary::kEntrySize == 2 || Dictionary::kEntrySize == 3);
   DCHECK(!key.IsName() || details.dictionary_index() > 0);
@@ -146,7 +144,7 @@ void Dictionary<Derived, Shape>::SetEntry(Isolate* isolate, InternalIndex entry,
   WriteBarrierMode mode = this->GetWriteBarrierMode(no_gc);
   this->set(index + Derived::kEntryKeyIndex, key, mode);
   this->set(index + Derived::kEntryValueIndex, value, mode);
-  if (Shape::kHasDetails) DetailsAtPut(isolate, entry, details);
+  if (Shape::kHasDetails) DetailsAtPut(entry, details);
 }
 
 template <typename Derived, typename Shape>
@@ -167,7 +165,7 @@ PropertyDetails BaseDictionaryShape<Key>::DetailsAt(Dictionary dict,
 
 template <typename Key>
 template <typename Dictionary>
-void BaseDictionaryShape<Key>::DetailsAtPut(Isolate* isolate, Dictionary dict,
+void BaseDictionaryShape<Key>::DetailsAtPut(Dictionary dict,
                                             InternalIndex entry,
                                             PropertyDetails value) {
   STATIC_ASSERT(Dictionary::kEntrySize == 3);
@@ -179,8 +177,8 @@ Object GlobalDictionaryShape::Unwrap(Object object) {
   return PropertyCell::cast(object).name();
 }
 
-RootIndex GlobalDictionaryShape::GetMapRootIndex() {
-  return RootIndex::kGlobalDictionaryMap;
+Handle<Map> GlobalDictionaryShape::GetMap(ReadOnlyRoots roots) {
+  return roots.global_dictionary_map_handle();
 }
 
 Name NameDictionary::NameAt(InternalIndex entry) {
@@ -192,8 +190,8 @@ Name NameDictionary::NameAt(const Isolate* isolate, InternalIndex entry) {
   return Name::cast(KeyAt(isolate, entry));
 }
 
-RootIndex NameDictionaryShape::GetMapRootIndex() {
-  return RootIndex::kNameDictionaryMap;
+Handle<Map> NameDictionaryShape::GetMap(ReadOnlyRoots roots) {
+  return roots.name_dictionary_map_handle();
 }
 
 PropertyCell GlobalDictionary::CellAt(InternalIndex entry) {
@@ -234,12 +232,11 @@ Object GlobalDictionary::ValueAt(const Isolate* isolate, InternalIndex entry) {
   return CellAt(isolate, entry).value(isolate);
 }
 
-void GlobalDictionary::SetEntry(Isolate* isolate, InternalIndex entry,
-                                Object key, Object value,
+void GlobalDictionary::SetEntry(InternalIndex entry, Object key, Object value,
                                 PropertyDetails details) {
   DCHECK_EQ(key, PropertyCell::cast(value).name());
   set(EntryToIndex(entry) + kEntryKeyIndex, value);
-  DetailsAtPut(isolate, entry, details);
+  DetailsAtPut(entry, details);
 }
 
 void GlobalDictionary::ValueAtPut(InternalIndex entry, Object value) {
@@ -251,8 +248,8 @@ bool NumberDictionaryBaseShape::IsMatch(uint32_t key, Object other) {
   return key == static_cast<uint32_t>(other.Number());
 }
 
-uint32_t NumberDictionaryBaseShape::Hash(Isolate* isolate, uint32_t key) {
-  return ComputeSeededHash(key, HashSeed(isolate));
+uint32_t NumberDictionaryBaseShape::Hash(ReadOnlyRoots roots, uint32_t key) {
+  return ComputeSeededHash(key, HashSeed(roots));
 }
 
 uint32_t NumberDictionaryBaseShape::HashForObject(ReadOnlyRoots roots,
@@ -267,12 +264,17 @@ Handle<Object> NumberDictionaryBaseShape::AsHandle(Isolate* isolate,
   return isolate->factory()->NewNumberFromUint(key);
 }
 
-RootIndex NumberDictionaryShape::GetMapRootIndex() {
-  return RootIndex::kNumberDictionaryMap;
+Handle<Object> NumberDictionaryBaseShape::AsHandle(OffThreadIsolate* isolate,
+                                                   uint32_t key) {
+  return isolate->factory()->NewNumberFromUint<AllocationType::kOld>(key);
+}
+
+Handle<Map> NumberDictionaryShape::GetMap(ReadOnlyRoots roots) {
+  return roots.number_dictionary_map_handle();
 }
 
-RootIndex SimpleNumberDictionaryShape::GetMapRootIndex() {
-  return RootIndex::kSimpleNumberDictionaryMap;
+Handle<Map> SimpleNumberDictionaryShape::GetMap(ReadOnlyRoots roots) {
+  return roots.simple_number_dictionary_map_handle();
 }
 
 bool NameDictionaryShape::IsMatch(Handle<Name> key, Object other) {
@@ -281,7 +283,7 @@ bool NameDictionaryShape::IsMatch(Handle<Name> key, Object other) {
   return *key == other;
 }
 
-uint32_t NameDictionaryShape::Hash(Isolate* isolate, Handle<Name> key) {
+uint32_t NameDictionaryShape::Hash(ReadOnlyRoots roots, Handle<Name> key) {
   return key->Hash();
 }
 
@@ -305,6 +307,12 @@ Handle<Object> NameDictionaryShape::AsHandle(Isolate* isolate,
   return key;
 }
 
+Handle<Object> NameDictionaryShape::AsHandle(OffThreadIsolate* isolate,
+                                             Handle<Name> key) {
+  DCHECK(key->IsUniqueName());
+  return key;
+}
+
 template <typename Dictionary>
 PropertyDetails GlobalDictionaryShape::DetailsAt(Dictionary dict,
                                                  InternalIndex entry) {
@@ -313,14 +321,13 @@ PropertyDetails GlobalDictionaryShape::DetailsAt(Dictionary dict,
 }
 
 template <typename Dictionary>
-void GlobalDictionaryShape::DetailsAtPut(Isolate* isolate, Dictionary dict,
-                                         InternalIndex entry,
+void GlobalDictionaryShape::DetailsAtPut(Dictionary dict, InternalIndex entry,
                                          PropertyDetails value) {
   DCHECK(entry.is_found());
   PropertyCell cell = dict.CellAt(entry);
   if (cell.property_details().IsReadOnly() != value.IsReadOnly()) {
     cell.dependent_code().DeoptimizeDependentCodeGroup(
-        isolate, DependentCode::kPropertyCellChangedGroup);
+        DependentCode::kPropertyCellChangedGroup);
   }
   cell.set_property_details(value);
 }
diff --git a/deps/v8/src/objects/dictionary.h b/deps/v8/src/objects/dictionary.h
index 66b601dbca..04a06960c9 100644
--- a/deps/v8/src/objects/dictionary.h
+++ b/deps/v8/src/objects/dictionary.h
@@ -41,8 +41,7 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Dictionary
   inline PropertyDetails DetailsAt(InternalIndex entry);
 
   // Set the details for entry.
-  inline void DetailsAtPut(Isolate* isolate, InternalIndex entry,
-                           PropertyDetails value);
+  inline void DetailsAtPut(InternalIndex entry, PropertyDetails value);
 
   // Delete a property from the dictionary.
   V8_WARN_UNUSED_RESULT static Handle<Derived> DeleteEntry(
@@ -66,15 +65,16 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Dictionary
   Object SlowReverseLookup(Object value);
 
   // Sets the entry to (key, value) pair.
-  inline void ClearEntry(Isolate* isolate, InternalIndex entry);
-  inline void SetEntry(Isolate* isolate, InternalIndex entry, Object key,
-                       Object value, PropertyDetails details);
+  inline void ClearEntry(InternalIndex entry);
+  inline void SetEntry(InternalIndex entry, Object key, Object value,
+                       PropertyDetails details);
 
   // Garbage collection support.
   inline ObjectSlot RawFieldOfValueAt(InternalIndex entry);
 
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> Add(
-      Isolate* isolate, Handle<Derived> dictionary, Key key,
+      LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
       Handle<Object> value, PropertyDetails details,
       InternalIndex* entry_out = nullptr);
 
@@ -89,6 +89,11 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Dictionary
   OBJECT_CONSTRUCTORS(Dictionary, HashTable<Derived, Shape>);
 };
 
+#define EXTERN_DECLARE_DICTIONARY(DERIVED, SHAPE)                  \
+  EXTERN_DECLARE_HASH_TABLE(DERIVED, SHAPE)                        \
+  extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) \
+      Dictionary<DERIVED, SHAPE>;
+
 template <typename Key>
 class BaseDictionaryShape : public BaseShape<Key> {
  public:
@@ -97,17 +102,19 @@ class BaseDictionaryShape : public BaseShape<Key> {
   static inline PropertyDetails DetailsAt(Dictionary dict, InternalIndex entry);
 
   template <typename Dictionary>
-  static inline void DetailsAtPut(Isolate* isolate, Dictionary dict,
-                                  InternalIndex entry, PropertyDetails value);
+  static inline void DetailsAtPut(Dictionary dict, InternalIndex entry,
+                                  PropertyDetails value);
 };
 
 class NameDictionaryShape : public BaseDictionaryShape<Handle<Name>> {
  public:
   static inline bool IsMatch(Handle<Name> key, Object other);
-  static inline uint32_t Hash(Isolate* isolate, Handle<Name> key);
+  static inline uint32_t Hash(ReadOnlyRoots roots, Handle<Name> key);
   static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
   static inline Handle<Object> AsHandle(Isolate* isolate, Handle<Name> key);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Object> AsHandle(OffThreadIsolate* isolate,
+                                        Handle<Name> key);
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static const int kPrefixSize = 2;
   static const int kEntrySize = 3;
   static const int kEntryValueIndex = 1;
@@ -129,8 +136,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) BaseNameDictionary
   inline int Hash() const;
 
   // Creates a new dictionary.
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> New(
-      Isolate* isolate, int at_least_space_for,
+      LocalIsolate* isolate, int at_least_space_for,
       AllocationType allocation = AllocationType::kYoung,
       MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY);
 
@@ -157,8 +165,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) BaseNameDictionary
                              Handle<FixedArray> storage, KeyCollectionMode mode,
                              KeyAccumulator* accumulator);
 
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> AddNoUpdateNextEnumerationIndex(
-      Isolate* isolate, Handle<Derived> dictionary, Key key,
+      LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
       Handle<Object> value, PropertyDetails details,
       InternalIndex* entry_out = nullptr);
 
@@ -170,10 +179,12 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) BaseNameDictionary
   OBJECT_CONSTRUCTORS(BaseNameDictionary, Dictionary<Derived, Shape>);
 };
 
-class NameDictionary;
+#define EXTERN_DECLARE_BASE_NAME_DICTIONARY(DERIVED, SHAPE)        \
+  EXTERN_DECLARE_DICTIONARY(DERIVED, SHAPE)                        \
+  extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) \
+      BaseNameDictionary<DERIVED, SHAPE>;
 
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    BaseNameDictionary<NameDictionary, NameDictionaryShape>;
+EXTERN_DECLARE_BASE_NAME_DICTIONARY(NameDictionary, NameDictionaryShape)
 
 class V8_EXPORT_PRIVATE NameDictionary
     : public BaseNameDictionary<NameDictionary, NameDictionaryShape> {
@@ -205,19 +216,16 @@ class V8_EXPORT_PRIVATE GlobalDictionaryShape : public NameDictionaryShape {
   static inline PropertyDetails DetailsAt(Dictionary dict, InternalIndex entry);
 
   template <typename Dictionary>
-  static inline void DetailsAtPut(Isolate* isolate, Dictionary dict,
-                                  InternalIndex entry, PropertyDetails value);
+  static inline void DetailsAtPut(Dictionary dict, InternalIndex entry,
+                                  PropertyDetails value);
 
   static inline Object Unwrap(Object key);
   static inline bool IsKey(ReadOnlyRoots roots, Object k);
   static inline bool IsLive(ReadOnlyRoots roots, Object key);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 };
 
-class GlobalDictionary;
-
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    BaseNameDictionary<GlobalDictionary, GlobalDictionaryShape>;
+EXTERN_DECLARE_BASE_NAME_DICTIONARY(GlobalDictionary, GlobalDictionaryShape)
 
 class V8_EXPORT_PRIVATE GlobalDictionary
     : public BaseNameDictionary<GlobalDictionary, GlobalDictionaryShape> {
@@ -228,8 +236,8 @@ class V8_EXPORT_PRIVATE GlobalDictionary
   inline Object ValueAt(const Isolate* isolate, InternalIndex entry);
   inline PropertyCell CellAt(InternalIndex entry);
   inline PropertyCell CellAt(const Isolate* isolate, InternalIndex entry);
-  inline void SetEntry(Isolate* isolate, InternalIndex entry, Object key,
-                       Object value, PropertyDetails details);
+  inline void SetEntry(InternalIndex entry, Object key, Object value,
+                       PropertyDetails details);
   inline Name NameAt(InternalIndex entry);
   inline Name NameAt(const Isolate* isolate, InternalIndex entry);
   inline void ValueAtPut(InternalIndex entry, Object value);
@@ -243,8 +251,10 @@ class NumberDictionaryBaseShape : public BaseDictionaryShape<uint32_t> {
  public:
   static inline bool IsMatch(uint32_t key, Object other);
   static inline Handle<Object> AsHandle(Isolate* isolate, uint32_t key);
+  static inline Handle<Object> AsHandle(OffThreadIsolate* isolate,
+                                        uint32_t key);
 
-  static inline uint32_t Hash(Isolate* isolate, uint32_t key);
+  static inline uint32_t Hash(ReadOnlyRoots roots, uint32_t key);
   static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
 };
 
@@ -253,7 +263,7 @@ class NumberDictionaryShape : public NumberDictionaryBaseShape {
   static const int kPrefixSize = 1;
   static const int kEntrySize = 3;
 
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 };
 
 class SimpleNumberDictionaryShape : public NumberDictionaryBaseShape {
@@ -269,19 +279,15 @@ class SimpleNumberDictionaryShape : public NumberDictionaryBaseShape {
   }
 
   template <typename Dictionary>
-  static inline void DetailsAtPut(Isolate* isolate, Dictionary dict,
-                                  InternalIndex entry, PropertyDetails value) {
+  static inline void DetailsAtPut(Dictionary dict, InternalIndex entry,
+                                  PropertyDetails value) {
     UNREACHABLE();
   }
 
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 };
 
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    HashTable<SimpleNumberDictionary, SimpleNumberDictionaryShape>;
-
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    Dictionary<SimpleNumberDictionary, SimpleNumberDictionaryShape>;
+EXTERN_DECLARE_DICTIONARY(SimpleNumberDictionary, SimpleNumberDictionaryShape)
 
 // SimpleNumberDictionary is used to map number to an entry.
 class SimpleNumberDictionary
@@ -300,11 +306,7 @@ class SimpleNumberDictionary
       Dictionary<SimpleNumberDictionary, SimpleNumberDictionaryShape>);
 };
 
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) HashTable<NumberDictionary, NumberDictionaryShape>;
-
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    Dictionary<NumberDictionary, NumberDictionaryShape>;
+EXTERN_DECLARE_DICTIONARY(NumberDictionary, NumberDictionaryShape)
 
 // NumberDictionary is used as elements backing store and provides a bitfield
 // and stores property details for every entry.
diff --git a/deps/v8/src/objects/elements.cc b/deps/v8/src/objects/elements.cc
index 4be8e0f0bd..d0c680d287 100644
--- a/deps/v8/src/objects/elements.cc
+++ b/deps/v8/src/objects/elements.cc
@@ -645,22 +645,22 @@ class ElementsAccessorBase : public InternalElementsAccessor {
     UNREACHABLE();
   }
 
-  uint32_t Push(Handle<JSArray> receiver, Arguments* args,
+  uint32_t Push(Handle<JSArray> receiver, BuiltinArguments* args,
                 uint32_t push_size) final {
     return Subclass::PushImpl(receiver, args, push_size);
   }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t push_sized) {
     UNREACHABLE();
   }
 
-  uint32_t Unshift(Handle<JSArray> receiver, Arguments* args,
+  uint32_t Unshift(Handle<JSArray> receiver, BuiltinArguments* args,
                    uint32_t unshift_size) final {
     return Subclass::UnshiftImpl(receiver, args, unshift_size);
   }
 
-  static uint32_t UnshiftImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t UnshiftImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                               uint32_t unshift_size) {
     UNREACHABLE();
   }
@@ -1383,7 +1383,7 @@ class DictionaryElementsAccessor
             if (dict->IsKey(roots, index)) {
               uint32_t number = static_cast<uint32_t>(index.Number());
               if (length <= number && number < old_length) {
-                dict->ClearEntry(isolate, entry);
+                dict->ClearEntry(entry);
                 removed_entries++;
               }
             }
@@ -1460,7 +1460,7 @@ class DictionaryElementsAccessor
     details = PropertyDetails(kData, attributes, PropertyCellType::kNoCell,
                               details.dictionary_index());
 
-    dictionary.DetailsAtPut(object->GetIsolate(), entry, details);
+    dictionary.DetailsAtPut(entry, details);
   }
 
   static void AddImpl(Handle<JSObject> object, uint32_t index,
@@ -2091,7 +2091,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     return Subclass::RemoveElement(receiver, AT_START);
   }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t push_size) {
     Handle<FixedArrayBase> backing_store(receiver->elements(),
                                          receiver->GetIsolate());
@@ -2099,7 +2099,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
                                   AT_END);
   }
 
-  static uint32_t UnshiftImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t UnshiftImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                               uint32_t unshift_size) {
     Handle<FixedArrayBase> backing_store(receiver->elements(),
                                          receiver->GetIsolate());
@@ -2347,7 +2347,7 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
 
   static uint32_t AddArguments(Handle<JSArray> receiver,
                                Handle<FixedArrayBase> backing_store,
-                               Arguments* args, uint32_t add_size,
+                               BuiltinArguments* args, uint32_t add_size,
                                Where add_position) {
     uint32_t length = Smi::ToInt(receiver->length());
     DCHECK_LT(0, add_size);
@@ -2382,7 +2382,8 @@ class FastElementsAccessor : public ElementsAccessorBase<Subclass, KindTraits> {
     return new_length;
   }
 
-  static void CopyArguments(Arguments* args, Handle<FixedArrayBase> dst_store,
+  static void CopyArguments(BuiltinArguments* args,
+                            Handle<FixedArrayBase> dst_store,
                             uint32_t copy_size, uint32_t src_index,
                             uint32_t dst_index) {
     // Add the provided values.
@@ -2564,7 +2565,7 @@ class FastNonextensibleObjectElementsAccessor
  public:
   using BackingStore = typename KindTraits::BackingStore;
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t push_size) {
     UNREACHABLE();
   }
@@ -2659,7 +2660,7 @@ class FastSealedObjectElementsAccessor
 
   static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t push_size) {
     UNREACHABLE();
   }
@@ -2720,14 +2721,12 @@ class FastSealedObjectElementsAccessor
 class FastPackedSealedObjectElementsAccessor
     : public FastSealedObjectElementsAccessor<
           FastPackedSealedObjectElementsAccessor,
-          ElementsKindTraits<PACKED_SEALED_ELEMENTS>> {
-};
+          ElementsKindTraits<PACKED_SEALED_ELEMENTS>> {};
 
 class FastHoleySealedObjectElementsAccessor
     : public FastSealedObjectElementsAccessor<
           FastHoleySealedObjectElementsAccessor,
-          ElementsKindTraits<HOLEY_SEALED_ELEMENTS>> {
-};
+          ElementsKindTraits<HOLEY_SEALED_ELEMENTS>> {};
 
 template <typename Subclass, typename KindTraits>
 class FastFrozenObjectElementsAccessor
@@ -2771,7 +2770,7 @@ class FastFrozenObjectElementsAccessor
 
   static Handle<Object> PopImpl(Handle<JSArray> receiver) { UNREACHABLE(); }
 
-  static uint32_t PushImpl(Handle<JSArray> receiver, Arguments* args,
+  static uint32_t PushImpl(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t push_size) {
     UNREACHABLE();
   }
@@ -2799,14 +2798,12 @@ class FastFrozenObjectElementsAccessor
 class FastPackedFrozenObjectElementsAccessor
     : public FastFrozenObjectElementsAccessor<
           FastPackedFrozenObjectElementsAccessor,
-          ElementsKindTraits<PACKED_FROZEN_ELEMENTS>> {
-};
+          ElementsKindTraits<PACKED_FROZEN_ELEMENTS>> {};
 
 class FastHoleyFrozenObjectElementsAccessor
     : public FastFrozenObjectElementsAccessor<
           FastHoleyFrozenObjectElementsAccessor,
-          ElementsKindTraits<HOLEY_FROZEN_ELEMENTS>> {
-};
+          ElementsKindTraits<HOLEY_FROZEN_ELEMENTS>> {};
 
 class FastHoleyObjectElementsAccessor
     : public FastSmiOrObjectElementsAccessor<
@@ -4632,8 +4629,8 @@ class SlowStringWrapperElementsAccessor
 
 }  // namespace
 
-MaybeHandle<Object> ArrayConstructInitializeElements(Handle<JSArray> array,
-                                                     Arguments* args) {
+MaybeHandle<Object> ArrayConstructInitializeElements(
+    Handle<JSArray> array, JavaScriptArguments* args) {
   if (args->length() == 0) {
     // Optimize the case where there are no parameters passed.
     JSArray::Initialize(array, JSArray::kPreallocatedArrayElements);
@@ -4669,7 +4666,7 @@ MaybeHandle<Object> ArrayConstructInitializeElements(Handle<JSArray> array,
 
   // Set length and elements on the array.
   int number_of_elements = args->length();
-  JSObject::EnsureCanContainElements(array, args, 0, number_of_elements,
+  JSObject::EnsureCanContainElements(array, args, number_of_elements,
                                      ALLOW_CONVERTED_DOUBLE_ELEMENTS);
 
   // Allocate an appropriately typed elements array.
@@ -4792,7 +4789,8 @@ void ElementsAccessor::TearDown() {
   elements_accessors_ = nullptr;
 }
 
-Handle<JSArray> ElementsAccessor::Concat(Isolate* isolate, Arguments* args,
+Handle<JSArray> ElementsAccessor::Concat(Isolate* isolate,
+                                         BuiltinArguments* args,
                                          uint32_t concat_size,
                                          uint32_t result_len) {
   ElementsKind result_elements_kind = GetInitialFastElementsKind();
diff --git a/deps/v8/src/objects/elements.h b/deps/v8/src/objects/elements.h
index a5d8103e68..551183fe6d 100644
--- a/deps/v8/src/objects/elements.h
+++ b/deps/v8/src/objects/elements.h
@@ -5,6 +5,7 @@
 #ifndef V8_OBJECTS_ELEMENTS_H_
 #define V8_OBJECTS_ELEMENTS_H_
 
+#include "src/builtins/builtins-utils.h"
 #include "src/objects/elements-kind.h"
 #include "src/objects/internal-index.h"
 #include "src/objects/keys.h"
@@ -111,13 +112,13 @@ class ElementsAccessor {
                    Handle<Object> value, PropertyAttributes attributes,
                    uint32_t new_capacity) = 0;
 
-  static Handle<JSArray> Concat(Isolate* isolate, Arguments* args,
+  static Handle<JSArray> Concat(Isolate* isolate, BuiltinArguments* args,
                                 uint32_t concat_size, uint32_t result_length);
 
-  virtual uint32_t Push(Handle<JSArray> receiver, Arguments* args,
+  virtual uint32_t Push(Handle<JSArray> receiver, BuiltinArguments* args,
                         uint32_t push_size) = 0;
 
-  virtual uint32_t Unshift(Handle<JSArray> receiver, Arguments* args,
+  virtual uint32_t Unshift(Handle<JSArray> receiver, BuiltinArguments* args,
                            uint32_t unshift_size) = 0;
 
   virtual Handle<Object> Pop(Handle<JSArray> receiver) = 0;
@@ -206,7 +207,7 @@ class ElementsAccessor {
 };
 
 V8_WARN_UNUSED_RESULT MaybeHandle<Object> ArrayConstructInitializeElements(
-    Handle<JSArray> array, Arguments* args);
+    Handle<JSArray> array, JavaScriptArguments* args);
 
 // Called directly from CSA.
 // {raw_context}: Context pointer.
diff --git a/deps/v8/src/objects/embedder-data-array-inl.h b/deps/v8/src/objects/embedder-data-array-inl.h
index 6775fa8075..9c514aef89 100644
--- a/deps/v8/src/objects/embedder-data-array-inl.h
+++ b/deps/v8/src/objects/embedder-data-array-inl.h
@@ -16,7 +16,6 @@
 namespace v8 {
 namespace internal {
 
-TQ_SMI_ACCESSORS(EmbedderDataArray, length)
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(EmbedderDataArray)
 
diff --git a/deps/v8/src/objects/embedder-data-array.h b/deps/v8/src/objects/embedder-data-array.h
index 668d890817..4fdf64bfc8 100644
--- a/deps/v8/src/objects/embedder-data-array.h
+++ b/deps/v8/src/objects/embedder-data-array.h
@@ -23,10 +23,6 @@ namespace internal {
 class EmbedderDataArray
     : public TorqueGeneratedEmbedderDataArray<EmbedderDataArray, HeapObject> {
  public:
-  // [length]: length of the array in an embedder data slots.
-  V8_INLINE int length() const;
-  V8_INLINE void set_length(int value);
-
   // TODO(v8:8989): [torque] Support marker constants.
   static const int kHeaderSize = kSize;
 
diff --git a/deps/v8/src/objects/embedder-data-array.tq b/deps/v8/src/objects/embedder-data-array.tq
index c576a06868..a3c4b6868e 100644
--- a/deps/v8/src/objects/embedder-data-array.tq
+++ b/deps/v8/src/objects/embedder-data-array.tq
@@ -4,5 +4,6 @@
 
 @generateCppClass
 extern class EmbedderDataArray extends HeapObject {
+  // length of the array in an embedder data slots.
   length: Smi;
 }
diff --git a/deps/v8/src/objects/feedback-cell-inl.h b/deps/v8/src/objects/feedback-cell-inl.h
index 9a570092e8..36d9bc8569 100644
--- a/deps/v8/src/objects/feedback-cell-inl.h
+++ b/deps/v8/src/objects/feedback-cell-inl.h
@@ -30,7 +30,7 @@ void FeedbackCell::reset_feedback_vector(
     base::Optional<std::function<void(HeapObject object, ObjectSlot slot,
                                       HeapObject target)>>
         gc_notify_updated_slot) {
-  set_interrupt_budget(FeedbackCell::GetInitialInterruptBudget());
+  SetInitialInterruptBudget();
   if (value().IsUndefined() || value().IsClosureFeedbackCellArray()) return;
 
   CHECK(value().IsFeedbackVector());
@@ -43,6 +43,18 @@ void FeedbackCell::reset_feedback_vector(
   }
 }
 
+void FeedbackCell::SetInitialInterruptBudget() {
+  if (FLAG_lazy_feedback_allocation) {
+    set_interrupt_budget(FLAG_budget_for_feedback_vector_allocation);
+  } else {
+    set_interrupt_budget(FLAG_interrupt_budget);
+  }
+}
+
+void FeedbackCell::SetInterruptBudget() {
+  set_interrupt_budget(FLAG_interrupt_budget);
+}
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/feedback-cell.h b/deps/v8/src/objects/feedback-cell.h
index 29304f709d..9728f8e8c0 100644
--- a/deps/v8/src/objects/feedback-cell.h
+++ b/deps/v8/src/objects/feedback-cell.h
@@ -20,13 +20,6 @@ namespace internal {
 // a native context.
 class FeedbackCell : public TorqueGeneratedFeedbackCell<FeedbackCell, Struct> {
  public:
-  static int GetInitialInterruptBudget() {
-    if (FLAG_lazy_feedback_allocation) {
-      return FLAG_budget_for_feedback_vector_allocation;
-    }
-    return FLAG_interrupt_budget;
-  }
-
   // Dispatched behavior.
   DECL_PRINTER(FeedbackCell)
 
@@ -38,6 +31,8 @@ class FeedbackCell : public TorqueGeneratedFeedbackCell<FeedbackCell, Struct> {
       base::Optional<std::function<void(HeapObject object, ObjectSlot slot,
                                         HeapObject target)>>
           gc_notify_updated_slot = base::nullopt);
+  inline void SetInitialInterruptBudget();
+  inline void SetInterruptBudget();
 
   using BodyDescriptor =
       FixedBodyDescriptor<kValueOffset, kInterruptBudgetOffset, kAlignedSize>;
diff --git a/deps/v8/src/objects/feedback-vector-inl.h b/deps/v8/src/objects/feedback-vector-inl.h
index 79382bb4d1..72b6e14883 100644
--- a/deps/v8/src/objects/feedback-vector-inl.h
+++ b/deps/v8/src/objects/feedback-vector-inl.h
@@ -149,9 +149,10 @@ bool FeedbackVector::has_optimization_marker() const {
 
 // Conversion from an integer index to either a slot or an ic slot.
 // static
-FeedbackSlot FeedbackVector::ToSlot(int index) {
-  DCHECK_GE(index, 0);
-  return FeedbackSlot(index);
+FeedbackSlot FeedbackVector::ToSlot(intptr_t index) {
+  DCHECK_LE(static_cast<uintptr_t>(index),
+            static_cast<uintptr_t>(std::numeric_limits<int>::max()));
+  return FeedbackSlot(static_cast<int>(index));
 }
 
 MaybeObject FeedbackVector::Get(FeedbackSlot slot) const {
diff --git a/deps/v8/src/objects/feedback-vector.cc b/deps/v8/src/objects/feedback-vector.cc
index 7028d2b0df..929b312f22 100644
--- a/deps/v8/src/objects/feedback-vector.cc
+++ b/deps/v8/src/objects/feedback-vector.cc
@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #include "src/objects/feedback-vector.h"
+#include "src/diagnostics/code-tracer.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/ic/handler-configuration-inl.h"
 #include "src/ic/ic-inl.h"
 #include "src/objects/data-handler-inl.h"
@@ -73,9 +75,10 @@ void FeedbackMetadata::SetKind(FeedbackSlot slot, FeedbackSlotKind kind) {
 }
 
 // static
-Handle<FeedbackMetadata> FeedbackMetadata::New(Isolate* isolate,
+template <typename LocalIsolate>
+Handle<FeedbackMetadata> FeedbackMetadata::New(LocalIsolate* isolate,
                                                const FeedbackVectorSpec* spec) {
-  Factory* factory = isolate->factory();
+  auto* factory = isolate->factory();
 
   const int slot_count = spec == nullptr ? 0 : spec->slots();
   const int closure_feedback_cell_count =
@@ -111,6 +114,11 @@ Handle<FeedbackMetadata> FeedbackMetadata::New(Isolate* isolate,
   return metadata;
 }
 
+template Handle<FeedbackMetadata> FeedbackMetadata::New(
+    Isolate* isolate, const FeedbackVectorSpec* spec);
+template Handle<FeedbackMetadata> FeedbackMetadata::New(
+    OffThreadIsolate* isolate, const FeedbackVectorSpec* spec);
+
 bool FeedbackMetadata::SpecDiffersFrom(
     const FeedbackVectorSpec* other_spec) const {
   if (other_spec->slots() != slot_count()) {
@@ -360,10 +368,12 @@ void FeedbackVector::EvictOptimizedCodeMarkedForDeoptimization(
   Code code = Code::cast(slot->GetHeapObject());
   if (code.marked_for_deoptimization()) {
     if (FLAG_trace_deopt) {
-      PrintF("[evicting optimizing code marked for deoptimization (%s) for ",
+      CodeTracer::Scope scope(GetIsolate()->GetCodeTracer());
+      PrintF(scope.file(),
+             "[evicting optimizing code marked for deoptimization (%s) for ",
              reason);
-      shared.ShortPrint();
-      PrintF("]\n");
+      shared.ShortPrint(scope.file());
+      PrintF(scope.file(), "]\n");
     }
     if (!code.deopt_already_counted()) {
       code.set_deopt_already_counted(true);
@@ -631,9 +641,16 @@ InlineCacheState FeedbackNexus::ic_state() const {
       if (feedback == MaybeObject::FromObject(
                           *FeedbackVector::MegamorphicSentinel(isolate))) {
         return GENERIC;
-      } else if (feedback->IsWeakOrCleared() ||
-                 (feedback->GetHeapObjectIfStrong(&heap_object) &&
-                  heap_object.IsAllocationSite())) {
+      } else if (feedback->IsWeakOrCleared()) {
+        if (feedback->GetHeapObjectIfWeak(&heap_object)) {
+          if (heap_object.IsFeedbackCell()) {
+            return POLYMORPHIC;
+          }
+          CHECK(heap_object.IsJSFunction() || heap_object.IsJSBoundFunction());
+        }
+        return MONOMORPHIC;
+      } else if (feedback->GetHeapObjectIfStrong(&heap_object) &&
+                 heap_object.IsAllocationSite()) {
         return MONOMORPHIC;
       }
 
diff --git a/deps/v8/src/objects/feedback-vector.h b/deps/v8/src/objects/feedback-vector.h
index 730f6825f4..f1d2cc3029 100644
--- a/deps/v8/src/objects/feedback-vector.h
+++ b/deps/v8/src/objects/feedback-vector.h
@@ -234,7 +234,7 @@ class FeedbackVector : public HeapObject {
   static int GetIndex(FeedbackSlot slot) { return slot.ToInt(); }
 
   // Conversion from an integer index to the underlying array to a slot.
-  static inline FeedbackSlot ToSlot(int index);
+  static inline FeedbackSlot ToSlot(intptr_t index);
   inline MaybeObject Get(FeedbackSlot slot) const;
   inline MaybeObject Get(const Isolate* isolate, FeedbackSlot slot) const;
   inline MaybeObject get(int index) const;
@@ -512,8 +512,9 @@ class FeedbackMetadata : public HeapObject {
   V8_EXPORT_PRIVATE FeedbackSlotKind GetKind(FeedbackSlot slot) const;
 
   // If {spec} is null, then it is considered empty.
+  template <typename LocalIsolate>
   V8_EXPORT_PRIVATE static Handle<FeedbackMetadata> New(
-      Isolate* isolate, const FeedbackVectorSpec* spec = nullptr);
+      LocalIsolate* isolate, const FeedbackVectorSpec* spec = nullptr);
 
   DECL_PRINTER(FeedbackMetadata)
   DECL_VERIFIER(FeedbackMetadata)
@@ -565,7 +566,7 @@ class FeedbackMetadata : public HeapObject {
 // possibly be confused with a pointer.
 // NOLINTNEXTLINE(runtime/references) (false positive)
 STATIC_ASSERT((Name::kEmptyHashField & kHeapObjectTag) == kHeapObjectTag);
-STATIC_ASSERT(Name::kEmptyHashField == 0x7);
+STATIC_ASSERT(Name::kEmptyHashField == 0x3);
 // Verify that a set hash field will not look like a tagged object.
 STATIC_ASSERT(Name::kHashNotComputedMask == kHeapObjectTag);
 
diff --git a/deps/v8/src/objects/fixed-array.tq b/deps/v8/src/objects/fixed-array.tq
index a0cd748b41..0c57e0bc63 100644
--- a/deps/v8/src/objects/fixed-array.tq
+++ b/deps/v8/src/objects/fixed-array.tq
@@ -4,7 +4,7 @@
 
 @abstract
 extern class FixedArrayBase extends HeapObject {
-  length: Smi;
+  const length: Smi;
 }
 
 extern class FixedArray extends FixedArrayBase { objects[length]: Object; }
@@ -29,9 +29,9 @@ extern class TemplateList extends FixedArray {
 }
 
 extern class WeakArrayList extends HeapObject {
-  capacity: Smi;
+  const capacity: Smi;
   length: Smi;
-  objects[length]: MaybeObject;
+  objects[capacity]: MaybeObject;
 }
 
 extern operator '.length_intptr' macro LoadAndUntagFixedArrayBaseLength(
diff --git a/deps/v8/src/objects/free-space-inl.h b/deps/v8/src/objects/free-space-inl.h
index 848b8202ae..318272c340 100644
--- a/deps/v8/src/objects/free-space-inl.h
+++ b/deps/v8/src/objects/free-space-inl.h
@@ -37,7 +37,8 @@ void FreeSpace::set_next(FreeSpace next) {
 }
 
 FreeSpace FreeSpace::cast(HeapObject o) {
-  SLOW_DCHECK(!GetHeapFromWritableObject(o)->deserialization_complete() ||
+  SLOW_DCHECK((!Heap::InOffThreadSpace(o) &&
+               !GetHeapFromWritableObject(o)->deserialization_complete()) ||
               o.IsFreeSpace());
   return bit_cast<FreeSpace>(o);
 }
diff --git a/deps/v8/src/objects/hash-table-inl.h b/deps/v8/src/objects/hash-table-inl.h
index 6a30ee1425..f713098f5f 100644
--- a/deps/v8/src/objects/hash-table-inl.h
+++ b/deps/v8/src/objects/hash-table-inl.h
@@ -123,17 +123,23 @@ void HashTableBase::SetNumberOfDeletedElements(int nod) {
 }
 
 template <typename Key>
-RootIndex BaseShape<Key>::GetMapRootIndex() {
-  return RootIndex::kHashTableMap;
+Handle<Map> BaseShape<Key>::GetMap(ReadOnlyRoots roots) {
+  return roots.hash_table_map_handle();
 }
 
-RootIndex EphemeronHashTableShape::GetMapRootIndex() {
-  return RootIndex::kEphemeronHashTableMap;
+Handle<Map> EphemeronHashTableShape::GetMap(ReadOnlyRoots roots) {
+  return roots.ephemeron_hash_table_map_handle();
 }
 
 template <typename Derived, typename Shape>
 InternalIndex HashTable<Derived, Shape>::FindEntry(Isolate* isolate, Key key) {
-  return FindEntry(ReadOnlyRoots(isolate), key, Shape::Hash(isolate, key));
+  return FindEntry(ReadOnlyRoots(isolate), key);
+}
+
+template <typename Derived, typename Shape>
+InternalIndex HashTable<Derived, Shape>::FindEntry(ReadOnlyRoots roots,
+                                                   Key key) {
+  return FindEntry(roots, key, Shape::Hash(roots, key));
 }
 
 // Find entry for key otherwise return kNotFound.
@@ -237,7 +243,7 @@ bool ObjectHashTableShape::IsMatch(Handle<Object> key, Object other) {
   return key->SameValue(other);
 }
 
-uint32_t ObjectHashTableShape::Hash(Isolate* isolate, Handle<Object> key) {
+uint32_t ObjectHashTableShape::Hash(ReadOnlyRoots roots, Handle<Object> key) {
   return Smi::ToInt(key->GetHash());
 }
 
diff --git a/deps/v8/src/objects/hash-table.h b/deps/v8/src/objects/hash-table.h
index a2d3221719..d59b1ae4fc 100644
--- a/deps/v8/src/objects/hash-table.h
+++ b/deps/v8/src/objects/hash-table.h
@@ -38,7 +38,7 @@ namespace internal {
 //     // Tells whether key matches other.
 //     static bool IsMatch(Key key, Object other);
 //     // Returns the hash value for key.
-//     static uint32_t Hash(Isolate* isolate, Key key);
+//     static uint32_t Hash(ReadOnlyRoots roots, Key key);
 //     // Returns the hash value for object.
 //     static uint32_t HashForObject(ReadOnlyRoots roots, Object object);
 //     // Convert key to an object.
@@ -60,7 +60,7 @@ template <typename KeyT>
 class V8_EXPORT_PRIVATE BaseShape {
  public:
   using Key = KeyT;
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static const bool kNeedsHoleCheck = true;
   static Object Unwrap(Object key) { return key; }
   static inline bool IsKey(ReadOnlyRoots roots, Object key);
@@ -129,8 +129,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   using Key = typename Shape::Key;
 
   // Returns a new HashTable object.
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> New(
-      Isolate* isolate, int at_least_space_for,
+      LocalIsolate* isolate, int at_least_space_for,
       AllocationType allocation = AllocationType::kYoung,
       MinimumCapacity capacity_option = USE_DEFAULT_MINIMUM_CAPACITY);
 
@@ -140,6 +141,7 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
 
   // Find entry for key otherwise return kNotFound.
   inline InternalIndex FindEntry(ReadOnlyRoots roots, Key key, int32_t hash);
+  inline InternalIndex FindEntry(ReadOnlyRoots roots, Key key);
   inline InternalIndex FindEntry(Isolate* isolate, Key key);
 
   // Rehashes the table in-place.
@@ -191,8 +193,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   }
 
   // Ensure enough space for n additional elements.
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> EnsureCapacity(
-      Isolate* isolate, Handle<Derived> table, int n = 1,
+      LocalIsolate* isolate, Handle<Derived> table, int n = 1,
       AllocationType allocation = AllocationType::kYoung);
 
   // Returns true if this table has sufficient capacity for adding n elements.
@@ -201,8 +204,9 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
  protected:
   friend class ObjectHashTable;
 
+  template <typename LocalIsolate>
   V8_WARN_UNUSED_RESULT static Handle<Derived> NewInternal(
-      Isolate* isolate, int capacity, AllocationType allocation);
+      LocalIsolate* isolate, int capacity, AllocationType allocation);
 
   // Find the entry at which to insert element with the given key that
   // has the given hash value.
@@ -243,6 +247,24 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) HashTable
   OBJECT_CONSTRUCTORS(HashTable, HashTableBase);
 };
 
+#define EXTERN_DECLARE_HASH_TABLE(DERIVED, SHAPE)                            \
+  extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)           \
+      HashTable<class DERIVED, SHAPE>;                                       \
+                                                                             \
+  extern template EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Handle<DERIVED> \
+  HashTable<DERIVED, SHAPE>::New(Isolate*, int, AllocationType,              \
+                                 MinimumCapacity);                           \
+  extern template EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Handle<DERIVED> \
+  HashTable<DERIVED, SHAPE>::New(OffThreadIsolate*, int, AllocationType,     \
+                                 MinimumCapacity);                           \
+                                                                             \
+  extern template EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Handle<DERIVED> \
+  HashTable<DERIVED, SHAPE>::EnsureCapacity(Isolate*, Handle<DERIVED>, int,  \
+                                            AllocationType);                 \
+  extern template EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) Handle<DERIVED> \
+  HashTable<DERIVED, SHAPE>::EnsureCapacity(                                 \
+      OffThreadIsolate*, Handle<DERIVED>, int, AllocationType);
+
 // HashTableKey is an abstract superclass for virtual key behavior.
 class HashTableKey {
  public:
@@ -269,7 +291,7 @@ class HashTableKey {
 class ObjectHashTableShape : public BaseShape<Handle<Object>> {
  public:
   static inline bool IsMatch(Handle<Object> key, Object other);
-  static inline uint32_t Hash(Isolate* isolate, Handle<Object> key);
+  static inline uint32_t Hash(ReadOnlyRoots roots, Handle<Object> key);
   static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
   static inline Handle<Object> AsHandle(Handle<Object> key);
   static const int kPrefixSize = 0;
@@ -321,12 +343,12 @@ class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) ObjectHashTableBase
   OBJECT_CONSTRUCTORS(ObjectHashTableBase, HashTable<Derived, Shape>);
 };
 
-class ObjectHashTable;
+#define EXTERN_DECLARE_OBJECT_BASE_HASH_TABLE(DERIVED, SHAPE)      \
+  EXTERN_DECLARE_HASH_TABLE(DERIVED, SHAPE)                        \
+  extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE) \
+      ObjectHashTableBase<class DERIVED, SHAPE>;
 
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) HashTable<ObjectHashTable, ObjectHashTableShape>;
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    ObjectHashTableBase<ObjectHashTable, ObjectHashTableShape>;
+EXTERN_DECLARE_OBJECT_BASE_HASH_TABLE(ObjectHashTable, ObjectHashTableShape)
 
 // ObjectHashTable maps keys that are arbitrary objects to object values by
 // using the identity hash of the key for hashing purposes.
@@ -343,15 +365,11 @@ class V8_EXPORT_PRIVATE ObjectHashTable
 
 class EphemeronHashTableShape : public ObjectHashTableShape {
  public:
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 };
 
-class EphemeronHashTable;
-
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) HashTable<EphemeronHashTable, EphemeronHashTableShape>;
-extern template class EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
-    ObjectHashTableBase<EphemeronHashTable, EphemeronHashTableShape>;
+EXTERN_DECLARE_OBJECT_BASE_HASH_TABLE(EphemeronHashTable,
+                                      EphemeronHashTableShape)
 
 // EphemeronHashTable is similar to ObjectHashTable but gets special treatment
 // by the GC. The GC treats its entries as ephemerons: both key and value are
@@ -383,9 +401,7 @@ class ObjectHashSetShape : public ObjectHashTableShape {
   static const int kEntrySize = 1;
 };
 
-class ObjectHashSet;
-extern template class EXPORT_TEMPLATE_DECLARE(
-    V8_EXPORT_PRIVATE) HashTable<ObjectHashSet, ObjectHashSetShape>;
+EXTERN_DECLARE_HASH_TABLE(ObjectHashSet, ObjectHashSetShape)
 
 class V8_EXPORT_PRIVATE ObjectHashSet
     : public HashTable<ObjectHashSet, ObjectHashSetShape> {
diff --git a/deps/v8/src/objects/heap-object.h b/deps/v8/src/objects/heap-object.h
index fcbb0ce833..b19d429320 100644
--- a/deps/v8/src/objects/heap-object.h
+++ b/deps/v8/src/objects/heap-object.h
@@ -84,9 +84,10 @@ class HeapObject : public Object {
 
 // Oddball checks are faster when they are raw pointer comparisons, so the
 // isolate/read-only roots overloads should be preferred where possible.
-#define IS_TYPE_FUNCTION_DECL(Type, Value)            \
-  V8_INLINE bool Is##Type(Isolate* isolate) const;    \
-  V8_INLINE bool Is##Type(ReadOnlyRoots roots) const; \
+#define IS_TYPE_FUNCTION_DECL(Type, Value)                  \
+  V8_INLINE bool Is##Type(Isolate* isolate) const;          \
+  V8_INLINE bool Is##Type(OffThreadIsolate* isolate) const; \
+  V8_INLINE bool Is##Type(ReadOnlyRoots roots) const;       \
   V8_INLINE bool Is##Type() const;
   ODDBALL_LIST(IS_TYPE_FUNCTION_DECL)
   IS_TYPE_FUNCTION_DECL(NullOrUndefined, /* unused */)
diff --git a/deps/v8/src/objects/heap-object.tq b/deps/v8/src/objects/heap-object.tq
index da80d0f944..e2f1fe4240 100644
--- a/deps/v8/src/objects/heap-object.tq
+++ b/deps/v8/src/objects/heap-object.tq
@@ -4,5 +4,5 @@
 
 @abstract
 extern class HeapObject extends StrongTagged {
-  map: Map;
+  const map: Map;
 }
diff --git a/deps/v8/src/objects/instance-type.h b/deps/v8/src/objects/instance-type.h
index acfb8759bf..5de264b1de 100644
--- a/deps/v8/src/objects/instance-type.h
+++ b/deps/v8/src/objects/instance-type.h
@@ -214,7 +214,6 @@ V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
   TORQUE_INSTANCE_CHECKERS_SINGLE_FULLY_DEFINED(V) \
   TORQUE_INSTANCE_CHECKERS_SINGLE_ONLY_DECLARED(V) \
   V(BigInt, BIGINT_TYPE)                           \
-  V(CoverageInfo, FIXED_ARRAY_TYPE)                \
   V(FixedArrayExact, FIXED_ARRAY_TYPE)
 
 #define INSTANCE_TYPE_CHECKERS_RANGE(V)           \
diff --git a/deps/v8/src/objects/intl-objects.cc b/deps/v8/src/objects/intl-objects.cc
index b201f7fb1e..dee27016d7 100644
--- a/deps/v8/src/objects/intl-objects.cc
+++ b/deps/v8/src/objects/intl-objects.cc
@@ -213,8 +213,8 @@ icu::UnicodeString Intl::ToICUUnicodeString(Isolate* isolate,
   return icu::UnicodeString(uchar_buffer, length);
 }
 
-icu::StringPiece Intl::ToICUStringPiece(Isolate* isolate,
-                                        Handle<String> string) {
+namespace {
+icu::StringPiece ToICUStringPiece(Isolate* isolate, Handle<String> string) {
   DCHECK(string->IsFlat());
   DisallowHeapAllocation no_gc;
 
@@ -231,7 +231,6 @@ icu::StringPiece Intl::ToICUStringPiece(Isolate* isolate,
   return icu::StringPiece(char_buffer, length);
 }
 
-namespace {
 MaybeHandle<String> LocaleConvertCase(Isolate* isolate, Handle<String> s,
                                       bool is_to_upper, const char* lang) {
   auto case_converter = is_to_upper ? u_strToUpper : u_strToLower;
@@ -432,7 +431,9 @@ std::string Intl::GetNumberingSystem(const icu::Locale& icu_locale) {
   return "latn";
 }
 
-icu::Locale Intl::CreateICULocale(const std::string& bcp47_locale) {
+namespace {
+
+Maybe<icu::Locale> CreateICULocale(const std::string& bcp47_locale) {
   DisallowHeapAllocation no_gc;
 
   // Convert BCP47 into ICU locale format.
@@ -441,12 +442,14 @@ icu::Locale Intl::CreateICULocale(const std::string& bcp47_locale) {
   icu::Locale icu_locale = icu::Locale::forLanguageTag(bcp47_locale, status);
   CHECK(U_SUCCESS(status));
   if (icu_locale.isBogus()) {
-    FATAL("Failed to create ICU locale, are ICU data files missing?");
+    return Nothing<icu::Locale>();
   }
 
-  return icu_locale;
+  return Just(icu_locale);
 }
 
+}  // anonymous namespace
+
 // static
 
 MaybeHandle<String> Intl::ToString(Isolate* isolate,
@@ -762,41 +765,15 @@ bool IsGrandfatheredTagWithoutPreferredVaule(const std::string& locale) {
   return false;
 }
 
-}  // anonymous namespace
-
-Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
-                                                 Handle<Object> locale_in) {
-  Handle<String> locale_str;
-  // This does part of the validity checking spec'ed in CanonicalizeLocaleList:
-  // 7c ii. If Type(kValue) is not String or Object, throw a TypeError
-  // exception.
-  // 7c iii. Let tag be ? ToString(kValue).
-  // 7c iv. If IsStructurallyValidLanguageTag(tag) is false, throw a
-  // RangeError exception.
-
-  if (locale_in->IsString()) {
-    locale_str = Handle<String>::cast(locale_in);
-  } else if (locale_in->IsJSReceiver()) {
-    ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, locale_str,
-                                     Object::ToString(isolate, locale_in),
-                                     Nothing<std::string>());
-  } else {
-    THROW_NEW_ERROR_RETURN_VALUE(isolate,
-                                 NewTypeError(MessageTemplate::kLanguageID),
-                                 Nothing<std::string>());
-  }
-  std::string locale(locale_str->ToCString().get());
-
-  if (!IsStructurallyValidLanguageTag(locale)) {
-    THROW_NEW_ERROR_RETURN_VALUE(
-        isolate, NewRangeError(MessageTemplate::kLocaleBadParameters),
-        Nothing<std::string>());
-  }
-  return Intl::CanonicalizeLanguageTag(isolate, locale);
+bool IsStructurallyValidLanguageTag(const std::string& tag) {
+  return JSLocale::StartsWithUnicodeLanguageId(tag);
 }
 
-Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
-                                                 const std::string& locale_in) {
+// Canonicalize the locale.
+// https://tc39.github.io/ecma402/#sec-canonicalizelanguagetag,
+// including type check and structural validity check.
+Maybe<std::string> CanonicalizeLanguageTag(Isolate* isolate,
+                                           const std::string& locale_in) {
   std::string locale = locale_in;
 
   if (locale.length() == 0 ||
@@ -864,6 +841,39 @@ Maybe<std::string> Intl::CanonicalizeLanguageTag(Isolate* isolate,
   return maybe_to_language_tag;
 }
 
+Maybe<std::string> CanonicalizeLanguageTag(Isolate* isolate,
+                                           Handle<Object> locale_in) {
+  Handle<String> locale_str;
+  // This does part of the validity checking spec'ed in CanonicalizeLocaleList:
+  // 7c ii. If Type(kValue) is not String or Object, throw a TypeError
+  // exception.
+  // 7c iii. Let tag be ? ToString(kValue).
+  // 7c iv. If IsStructurallyValidLanguageTag(tag) is false, throw a
+  // RangeError exception.
+
+  if (locale_in->IsString()) {
+    locale_str = Handle<String>::cast(locale_in);
+  } else if (locale_in->IsJSReceiver()) {
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, locale_str,
+                                     Object::ToString(isolate, locale_in),
+                                     Nothing<std::string>());
+  } else {
+    THROW_NEW_ERROR_RETURN_VALUE(isolate,
+                                 NewTypeError(MessageTemplate::kLanguageID),
+                                 Nothing<std::string>());
+  }
+  std::string locale(locale_str->ToCString().get());
+
+  if (!IsStructurallyValidLanguageTag(locale)) {
+    THROW_NEW_ERROR_RETURN_VALUE(
+        isolate, NewRangeError(MessageTemplate::kLocaleBadParameters),
+        Nothing<std::string>());
+  }
+  return CanonicalizeLanguageTag(isolate, locale);
+}
+
+}  // anonymous namespace
+
 Maybe<std::vector<std::string>> Intl::CanonicalizeLocaleList(
     Isolate* isolate, Handle<Object> locales, bool only_return_one_result) {
   // 1. If locales is undefined, then
@@ -1069,9 +1079,9 @@ Handle<Object> Intl::CompareStrings(Isolate* isolate,
 
   UCollationResult result;
   UErrorCode status = U_ZERO_ERROR;
-  icu::StringPiece string_piece1 = Intl::ToICUStringPiece(isolate, string1);
+  icu::StringPiece string_piece1 = ToICUStringPiece(isolate, string1);
   if (!string_piece1.empty()) {
-    icu::StringPiece string_piece2 = Intl::ToICUStringPiece(isolate, string2);
+    icu::StringPiece string_piece2 = ToICUStringPiece(isolate, string2);
     if (!string_piece2.empty()) {
       result = icu_collator.compareUTF8(string_piece1, string_piece2, status);
       DCHECK(U_SUCCESS(status));
@@ -1857,7 +1867,7 @@ std::string LookupMatcher(Isolate* isolate,
 // this method perform such normalization.
 //
 // ecma402/#sec-resolvelocale
-Intl::ResolvedLocale Intl::ResolveLocale(
+Maybe<Intl::ResolvedLocale> Intl::ResolveLocale(
     Isolate* isolate, const std::set<std::string>& available_locales,
     const std::vector<std::string>& requested_locales, MatcherOption matcher,
     const std::set<std::string>& relevant_extension_keys) {
@@ -1868,7 +1878,9 @@ Intl::ResolvedLocale Intl::ResolveLocale(
     locale = LookupMatcher(isolate, available_locales, requested_locales);
   }
 
-  icu::Locale icu_locale = CreateICULocale(locale);
+  Maybe<icu::Locale> maybe_icu_locale = CreateICULocale(locale);
+  MAYBE_RETURN(maybe_icu_locale, Nothing<Intl::ResolvedLocale>());
+  icu::Locale icu_locale = maybe_icu_locale.FromJust();
   std::map<std::string, std::string> extensions =
       LookupAndValidateUnicodeExtensions(&icu_locale, relevant_extension_keys);
 
@@ -1876,7 +1888,8 @@ Intl::ResolvedLocale Intl::ResolveLocale(
 
   // TODO(gsathya): Remove privateuse subtags from extensions.
 
-  return Intl::ResolvedLocale{canonicalized_locale, icu_locale, extensions};
+  return Just(
+      Intl::ResolvedLocale{canonicalized_locale, icu_locale, extensions});
 }
 
 Handle<Managed<icu::UnicodeString>> Intl::SetTextToBreakIterator(
@@ -2062,26 +2075,6 @@ base::TimezoneCache* Intl::CreateTimeZoneCache() {
                                 : base::OS::CreateTimezoneCache();
 }
 
-Maybe<Intl::CaseFirst> Intl::GetCaseFirst(Isolate* isolate,
-                                          Handle<JSReceiver> options,
-                                          const char* method) {
-  return Intl::GetStringOption<Intl::CaseFirst>(
-      isolate, options, "caseFirst", method, {"upper", "lower", "false"},
-      {Intl::CaseFirst::kUpper, Intl::CaseFirst::kLower,
-       Intl::CaseFirst::kFalse},
-      Intl::CaseFirst::kUndefined);
-}
-
-Maybe<Intl::HourCycle> Intl::GetHourCycle(Isolate* isolate,
-                                          Handle<JSReceiver> options,
-                                          const char* method) {
-  return Intl::GetStringOption<Intl::HourCycle>(
-      isolate, options, "hourCycle", method, {"h11", "h12", "h23", "h24"},
-      {Intl::HourCycle::kH11, Intl::HourCycle::kH12, Intl::HourCycle::kH23,
-       Intl::HourCycle::kH24},
-      Intl::HourCycle::kUndefined);
-}
-
 Maybe<Intl::MatcherOption> Intl::GetLocaleMatcher(Isolate* isolate,
                                                   Handle<JSReceiver> options,
                                                   const char* method) {
@@ -2114,14 +2107,6 @@ Maybe<bool> Intl::GetNumberingSystem(Isolate* isolate,
   return Just(false);
 }
 
-Intl::HourCycle Intl::ToHourCycle(const std::string& hc) {
-  if (hc == "h11") return Intl::HourCycle::kH11;
-  if (hc == "h12") return Intl::HourCycle::kH12;
-  if (hc == "h23") return Intl::HourCycle::kH23;
-  if (hc == "h24") return Intl::HourCycle::kH24;
-  return Intl::HourCycle::kUndefined;
-}
-
 const std::set<std::string>& Intl::GetAvailableLocalesForLocale() {
   static base::LazyInstance<Intl::AvailableLocales<icu::Locale>>::type
       available_locales = LAZY_INSTANCE_INITIALIZER;
@@ -2217,9 +2202,6 @@ MaybeHandle<String> Intl::FormattedToString(
   return Intl::ToString(isolate, result);
 }
 
-bool Intl::IsStructurallyValidLanguageTag(const std::string& tag) {
-  return JSLocale::StartsWithUnicodeLanguageId(tag);
-}
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects/intl-objects.h b/deps/v8/src/objects/intl-objects.h
index 3ae098f661..0d8cab42e8 100644
--- a/deps/v8/src/objects/intl-objects.h
+++ b/deps/v8/src/objects/intl-objects.h
@@ -27,7 +27,6 @@ namespace U_ICU_NAMESPACE {
 class BreakIterator;
 class Collator;
 class FormattedValue;
-class SimpleDateFormat;
 class UnicodeString;
 }  // namespace U_ICU_NAMESPACE
 
@@ -132,15 +131,6 @@ class Intl {
       Isolate* isolate, Handle<JSReceiver> options, Handle<String> property,
       int min, int max, int fallback);
 
-  // Canonicalize the locale.
-  // https://tc39.github.io/ecma402/#sec-canonicalizelanguagetag,
-  // including type check and structural validity check.
-  static Maybe<std::string> CanonicalizeLanguageTag(Isolate* isolate,
-                                                    Handle<Object> locale_in);
-
-  static Maybe<std::string> CanonicalizeLanguageTag(Isolate* isolate,
-                                                    const std::string& locale);
-
   // https://tc39.github.io/ecma402/#sec-canonicalizelocalelist
   // {only_return_one_result} is an optimization for callers that only
   // care about the first result.
@@ -189,8 +179,6 @@ class Intl {
                               int mnfd_default, int mxfd_default,
                               bool notation_is_compact);
 
-  static icu::Locale CreateICULocale(const std::string& bcp47_locale);
-
   // Helper funciton to convert a UnicodeString to a Handle<String>
   V8_WARN_UNUSED_RESULT static MaybeHandle<String> ToString(
       Isolate* isolate, const icu::UnicodeString& string);
@@ -239,22 +227,6 @@ class Intl {
       Isolate* isolate, Handle<JSReceiver> receiver,
       Handle<JSFunction> constructor, bool has_initialized_slot);
 
-  // enum for "caseFirst" option: shared by Intl.Locale and Intl.Collator.
-  enum class CaseFirst { kUndefined, kUpper, kLower, kFalse };
-
-  // Shared function to read the "caseFirst" option.
-  V8_WARN_UNUSED_RESULT static Maybe<CaseFirst> GetCaseFirst(
-      Isolate* isolate, Handle<JSReceiver> options, const char* method);
-
-  // enum for "hourCycle" option: shared by Intl.Locale and Intl.DateTimeFormat.
-  enum class HourCycle { kUndefined, kH11, kH12, kH23, kH24 };
-
-  static HourCycle ToHourCycle(const std::string& str);
-
-  // Shared function to read the "hourCycle" option.
-  V8_WARN_UNUSED_RESULT static Maybe<HourCycle> GetHourCycle(
-      Isolate* isolate, Handle<JSReceiver> options, const char* method);
-
   // enum for "localeMatcher" option: shared by many Intl objects.
   enum class MatcherOption { kBestFit, kLookup };
 
@@ -286,7 +258,7 @@ class Intl {
     std::map<std::string, std::string> extensions;
   };
 
-  static ResolvedLocale ResolveLocale(
+  static Maybe<ResolvedLocale> ResolveLocale(
       Isolate* isolate, const std::set<std::string>& available_locales,
       const std::vector<std::string>& requested_locales, MatcherOption options,
       const std::set<std::string>& relevant_extension_keys);
@@ -335,10 +307,6 @@ class Intl {
   static icu::UnicodeString ToICUUnicodeString(Isolate* isolate,
                                                Handle<String> string);
 
-  // Convert a Handle<String> to icu::StringPiece
-  static icu::StringPiece ToICUStringPiece(Isolate* isolate,
-                                           Handle<String> string);
-
   static const uint8_t* ToLatin1LowerTable();
 
   static String ConvertOneByteToLower(String src, String dst);
@@ -346,8 +314,6 @@ class Intl {
   static const std::set<std::string>& GetAvailableLocalesForLocale();
 
   static const std::set<std::string>& GetAvailableLocalesForDateFormat();
-
-  static bool IsStructurallyValidLanguageTag(const std::string& tag);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/intl-objects.tq b/deps/v8/src/objects/intl-objects.tq
index f47c0f4adc..8f4f130a0d 100644
--- a/deps/v8/src/objects/intl-objects.tq
+++ b/deps/v8/src/objects/intl-objects.tq
@@ -15,64 +15,107 @@
 #include 'src/objects/js-segment-iterator.h'
 #include 'src/objects/js-segmenter.h'
 
+type DateTimeStyle extends int32 constexpr 'JSDateTimeFormat::DateTimeStyle';
+type HourCycle extends int32 constexpr 'JSDateTimeFormat::HourCycle';
+bitfield struct JSDateTimeFormatFlags extends uint31 {
+  hour_cycle: HourCycle: 3 bit;
+  date_style: DateTimeStyle: 3 bit;
+  time_style: DateTimeStyle: 3 bit;
+}
+
 extern class JSDateTimeFormat extends JSObject {
   locale: String;
   icu_locale: Foreign;                // Managed<icu::Locale>
   icu_simple_date_format: Foreign;    // Managed<icu::SimpleDateFormat>
   icu_date_interval_format: Foreign;  // Managed<icu::DateIntervalFormat>
   bound_format: JSFunction|Undefined;
-  flags: Smi;
+  flags: SmiTagged<JSDateTimeFormatFlags>;
+}
+
+type JSDisplayNamesStyle extends int32 constexpr 'JSDisplayNames::Style';
+type JSDisplayNamesFallback extends int32
+constexpr 'JSDisplayNames::Fallback';
+bitfield struct JSDisplayNamesFlags extends uint31 {
+  style: JSDisplayNamesStyle: 2 bit;
+  fallback: JSDisplayNamesFallback: 1 bit;
 }
 
 extern class JSDisplayNames extends JSObject {
   internal: Foreign;  // Managed<DisplayNamesInternal>
-  flags: Smi;
+  flags: SmiTagged<JSDisplayNamesFlags>;
+}
+
+type JSListFormatStyle extends int32 constexpr 'JSListFormat::Style';
+type JSListFormatType extends int32 constexpr 'JSListFormat::Type';
+bitfield struct JSListFormatFlags extends uint31 {
+  style: JSListFormatStyle: 2 bit;
+  Type: JSListFormatType: 2 bit;  // "type" is a reserved word.
 }
 
 extern class JSListFormat extends JSObject {
   locale: String;
   icu_formatter: Foreign;  // Managed<icu::ListFormatter>
-  flags: Smi;
+  flags: SmiTagged<JSListFormatFlags>;
 }
 
 extern class JSNumberFormat extends JSObject {
   locale: String;
-  numberingSystem: String;
   icu_number_formatter:
       Foreign;  // Managed<icu::number::LocalizedNumberFormatter>
   bound_format: JSFunction|Undefined;
-  flags: Smi;
+}
+
+type JSPluralRulesType extends int32 constexpr 'JSPluralRules::Type';
+bitfield struct JSPluralRulesFlags extends uint31 {
+  Type: JSPluralRulesType: 1 bit;  // "type" is a reserved word.
 }
 
 extern class JSPluralRules extends JSObject {
   locale: String;
-  flags: Smi;
+  flags: SmiTagged<JSPluralRulesFlags>;
   icu_plural_rules: Foreign;  // Managed<icu::PluralRules>
   icu_number_formatter:
       Foreign;  // Managed<icu::number::LocalizedNumberFormatter>
 }
 
+type JSRelativeTimeFormatNumeric extends int32
+constexpr 'JSRelativeTimeFormat::Numeric';
+bitfield struct JSRelativeTimeFormatFlags extends uint31 {
+  numeric: JSRelativeTimeFormatNumeric: 1 bit;
+}
+
 extern class JSRelativeTimeFormat extends JSObject {
   locale: String;
   numberingSystem: String;
   icu_formatter: Foreign;  // Managed<icu::RelativeDateTimeFormatter>
-  flags: Smi;
+  flags: SmiTagged<JSRelativeTimeFormatFlags>;
 }
 
 extern class JSLocale extends JSObject {
   icu_locale: Foreign;  // Managed<icu::Locale>
 }
 
+type JSSegmenterGranularity extends int32
+constexpr 'JSSegmenter::Granularity';
+bitfield struct JSSegmenterFlags extends uint31 {
+  granularity: JSSegmenterGranularity: 2 bit;
+}
+
 extern class JSSegmenter extends JSObject {
   locale: String;
   icu_break_iterator: Foreign;  // Managed<icu::BreakIterator>
-  flags: Smi;
+  flags: SmiTagged<JSSegmenterFlags>;
+}
+
+bitfield struct JSSegmentIteratorFlags extends uint31 {
+  granularity: JSSegmenterGranularity: 2 bit;
+  break_type_set: bool: 1 bit;
 }
 
 extern class JSSegmentIterator extends JSObject {
   icu_break_iterator: Foreign;  // Managed<icu::BreakIterator>
   unicode_string: Foreign;      // Managed<icu::UnicodeString>
-  flags: Smi;
+  flags: SmiTagged<JSSegmentIteratorFlags>;
 }
 
 extern class JSV8BreakIterator extends JSObject {
@@ -84,7 +127,6 @@ extern class JSV8BreakIterator extends JSObject {
   bound_next: Undefined|JSFunction;
   bound_current: Undefined|JSFunction;
   bound_break_type: Undefined|JSFunction;
-  break_iterator_type: Smi;
 }
 
 extern class JSCollator extends JSObject {
diff --git a/deps/v8/src/objects/js-array-buffer-inl.h b/deps/v8/src/objects/js-array-buffer-inl.h
index 45b9d8c8b0..b77f5580e2 100644
--- a/deps/v8/src/objects/js-array-buffer-inl.h
+++ b/deps/v8/src/objects/js-array-buffer-inl.h
@@ -46,26 +46,74 @@ void JSArrayBuffer::set_backing_store(void* value) {
 
 ArrayBufferExtension* JSArrayBuffer::extension() const {
   if (V8_ARRAY_BUFFER_EXTENSION_BOOL) {
+#if V8_COMPRESS_POINTERS
+    // With pointer compression the extension-field might not be
+    // pointer-aligned. However on ARM64 this field needs to be aligned to
+    // perform atomic operations on it. Therefore we split the pointer into two
+    // 32-bit words that we update atomically. We don't have an ABA problem here
+    // since there can never be an Attach() after Detach() (transitions only
+    // from NULL --> some ptr --> NULL).
+
+    // Synchronize with publishing release store of non-null extension
+    uint32_t lo = base::AsAtomic32::Acquire_Load(extension_lo());
+    if (lo & kUninitializedTagMask) return nullptr;
+
+    // Synchronize with release store of null extension
+    uint32_t hi = base::AsAtomic32::Acquire_Load(extension_hi());
+    uint32_t verify_lo = base::AsAtomic32::Relaxed_Load(extension_lo());
+    if (lo != verify_lo) return nullptr;
+
+    uintptr_t address = static_cast<uintptr_t>(lo);
+    address |= static_cast<uintptr_t>(hi) << 32;
+    return reinterpret_cast<ArrayBufferExtension*>(address);
+#else
     return base::AsAtomicPointer::Acquire_Load(extension_location());
+#endif
   } else {
     return nullptr;
   }
 }
 
+void JSArrayBuffer::set_extension(ArrayBufferExtension* extension) {
+  if (V8_ARRAY_BUFFER_EXTENSION_BOOL) {
+#if V8_COMPRESS_POINTERS
+    if (extension != nullptr) {
+      uintptr_t address = reinterpret_cast<uintptr_t>(extension);
+      base::AsAtomic32::Relaxed_Store(extension_hi(),
+                                      static_cast<uint32_t>(address >> 32));
+      base::AsAtomic32::Release_Store(extension_lo(),
+                                      static_cast<uint32_t>(address));
+    } else {
+      base::AsAtomic32::Relaxed_Store(extension_lo(),
+                                      0 | kUninitializedTagMask);
+      base::AsAtomic32::Release_Store(extension_hi(), 0);
+    }
+#else
+    base::AsAtomicPointer::Release_Store(extension_location(), extension);
+#endif
+    MarkingBarrierForArrayBufferExtension(*this, extension);
+  } else {
+    CHECK_EQ(extension, nullptr);
+  }
+}
+
 ArrayBufferExtension** JSArrayBuffer::extension_location() const {
   Address location = field_address(kExtensionOffset);
   return reinterpret_cast<ArrayBufferExtension**>(location);
 }
 
-void JSArrayBuffer::set_extension(ArrayBufferExtension* value) {
-  if (V8_ARRAY_BUFFER_EXTENSION_BOOL) {
-    base::AsAtomicPointer::Release_Store(extension_location(), value);
-    MarkingBarrierForArrayBufferExtension(*this, value);
-  } else {
-    CHECK_EQ(value, nullptr);
-  }
+#if V8_COMPRESS_POINTERS
+uint32_t* JSArrayBuffer::extension_lo() const {
+  Address location = field_address(kExtensionOffset);
+  return reinterpret_cast<uint32_t*>(location);
 }
 
+uint32_t* JSArrayBuffer::extension_hi() const {
+  Address location = field_address(kExtensionOffset) + sizeof(uint32_t);
+  return reinterpret_cast<uint32_t*>(location);
+}
+#endif
+
 size_t JSArrayBuffer::allocation_length() const {
   if (backing_store() == nullptr) {
     return 0;
@@ -108,6 +156,7 @@ BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_asmjs_memory,
 BIT_FIELD_ACCESSORS(JSArrayBuffer, bit_field, is_shared,
                     JSArrayBuffer::IsSharedBit)
 
+
 size_t JSArrayBufferView::byte_offset() const {
   return ReadField<size_t>(kByteOffsetOffset);
 }
diff --git a/deps/v8/src/objects/js-array-buffer.cc b/deps/v8/src/objects/js-array-buffer.cc
index f4f4320537..0c2aca6d71 100644
--- a/deps/v8/src/objects/js-array-buffer.cc
+++ b/deps/v8/src/objects/js-array-buffer.cc
@@ -59,14 +59,18 @@ void JSArrayBuffer::Setup(SharedFlag shared,
 void JSArrayBuffer::Attach(std::shared_ptr<BackingStore> backing_store) {
   DCHECK_NOT_NULL(backing_store);
   DCHECK_EQ(is_shared(), backing_store->is_shared());
+  DCHECK(!was_detached());
   set_backing_store(backing_store->buffer_start());
   set_byte_length(backing_store->byte_length());
   if (backing_store->is_wasm_memory()) set_is_detachable(false);
   if (!backing_store->free_on_destruct()) set_is_external(true);
   if (V8_ARRAY_BUFFER_EXTENSION_BOOL) {
     Heap* heap = GetIsolate()->heap();
-    EnsureExtension(heap);
-    extension()->set_backing_store(std::move(backing_store));
+    ArrayBufferExtension* extension = EnsureExtension();
+    size_t bytes = backing_store->PerIsolateAccountingLength();
+    extension->set_accounting_length(bytes);
+    extension->set_backing_store(std::move(backing_store));
+    heap->AppendArrayBufferExtension(*this, extension);
   } else {
     GetIsolate()->heap()->RegisterBackingStore(*this, std::move(backing_store));
   }
@@ -113,14 +117,13 @@ std::shared_ptr<BackingStore> JSArrayBuffer::GetBackingStore() {
   }
 }
 
-ArrayBufferExtension* JSArrayBuffer::EnsureExtension(Heap* heap) {
+ArrayBufferExtension* JSArrayBuffer::EnsureExtension() {
   DCHECK(V8_ARRAY_BUFFER_EXTENSION_BOOL);
-  if (extension() != nullptr) return extension();
+  ArrayBufferExtension* extension = this->extension();
+  if (extension != nullptr) return extension;
 
-  ArrayBufferExtension* extension =
-      new ArrayBufferExtension(std::shared_ptr<BackingStore>());
+  extension = new ArrayBufferExtension(std::shared_ptr<BackingStore>());
   set_extension(extension);
-  heap->AppendArrayBufferExtension(*this, extension);
   return extension;
 }
 
diff --git a/deps/v8/src/objects/js-array-buffer.h b/deps/v8/src/objects/js-array-buffer.h
index 1f3024ef6a..624b716713 100644
--- a/deps/v8/src/objects/js-array-buffer.h
+++ b/deps/v8/src/objects/js-array-buffer.h
@@ -5,9 +5,9 @@
 #ifndef V8_OBJECTS_JS_ARRAY_BUFFER_H_
 #define V8_OBJECTS_JS_ARRAY_BUFFER_H_
 
-#include "src/base/bit-field.h"
 #include "src/objects/backing-store.h"
 #include "src/objects/js-objects.h"
+#include "torque-generated/bit-fields-tq.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -51,14 +51,7 @@ class JSArrayBuffer : public JSObject {
   V8_INLINE void clear_padding();
 
 // Bit positions for [bit_field].
-#define JS_ARRAY_BUFFER_BIT_FIELD_FIELDS(V, _) \
-  V(IsExternalBit, bool, 1, _)                 \
-  V(IsDetachableBit, bool, 1, _)               \
-  V(WasDetachedBit, bool, 1, _)                \
-  V(IsAsmJsMemoryBit, bool, 1, _)              \
-  V(IsSharedBit, bool, 1, _)
-  DEFINE_BIT_FIELDS(JS_ARRAY_BUFFER_BIT_FIELD_FIELDS)
-#undef JS_ARRAY_BUFFER_BIT_FIELD_FIELDS
+  DEFINE_TORQUE_GENERATED_JS_ARRAY_BUFFER_FLAGS()
 
   // [is_external]: true indicates that the embedder is in charge of freeing the
   // backing_store, while is_external == false means that v8 will free the
@@ -107,7 +100,7 @@ class JSArrayBuffer : public JSObject {
 
   // Allocates an ArrayBufferExtension for this array buffer, unless it is
   // already associated with an extension.
-  ArrayBufferExtension* EnsureExtension(Heap* heap);
+  ArrayBufferExtension* EnsureExtension();
 
   // Frees the associated ArrayBufferExtension and returns its backing store.
   std::shared_ptr<BackingStore> RemoveExtension();
@@ -121,22 +114,10 @@ class JSArrayBuffer : public JSObject {
   DECL_PRINTER(JSArrayBuffer)
   DECL_VERIFIER(JSArrayBuffer)
 
-// Layout description.
-#define JS_ARRAY_BUFFER_FIELDS(V)                                           \
-  V(kEndOfTaggedFieldsOffset, 0)                                            \
-  /* Raw data fields. */                                                    \
-  V(kByteLengthOffset, kUIntptrSize)                                        \
-  V(kBackingStoreOffset, kSystemPointerSize)                                \
-  V(kExtensionOffset,                                                       \
-    (V8_ARRAY_BUFFER_EXTENSION_BOOL ? kSystemPointerSize : 0))              \
-  V(kBitFieldOffset, kInt32Size)                                            \
-  /* Pads header size to be a multiple of kTaggedSize. */                   \
-  V(kOptionalPaddingOffset, OBJECT_POINTER_PADDING(kOptionalPaddingOffset)) \
-  /* Header size. */                                                        \
-  V(kHeaderSize, 0)
-
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize, JS_ARRAY_BUFFER_FIELDS)
-#undef JS_ARRAY_BUFFER_FIELDS
+  // Layout description.
+  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
+                                TORQUE_GENERATED_JS_ARRAY_BUFFER_FIELDS)
+  static constexpr int kEndOfTaggedFieldsOffset = JSObject::kHeaderSize;
 
   static const int kSizeWithEmbedderFields =
       kHeaderSize +
@@ -148,6 +129,13 @@ class JSArrayBuffer : public JSObject {
 
  private:
   inline ArrayBufferExtension** extension_location() const;
+
+#if V8_COMPRESS_POINTERS
+  static const int kUninitializedTagMask = 1;
+
+  inline uint32_t* extension_lo() const;
+  inline uint32_t* extension_hi() const;
+#endif
 };
 
 // Each JSArrayBuffer (with a backing store) has a corresponding native-heap
@@ -163,6 +151,7 @@ class ArrayBufferExtension : public Malloced {
   std::atomic<GcState> young_gc_state_;
   std::shared_ptr<BackingStore> backing_store_;
   ArrayBufferExtension* next_;
+  std::size_t accounting_length_;
 
   GcState young_gc_state() {
     return young_gc_state_.load(std::memory_order_relaxed);
@@ -177,12 +166,14 @@ class ArrayBufferExtension : public Malloced {
       : marked_(false),
         young_gc_state_(GcState::Dead),
         backing_store_(std::shared_ptr<BackingStore>()),
-        next_(nullptr) {}
+        next_(nullptr),
+        accounting_length_(0) {}
   explicit ArrayBufferExtension(std::shared_ptr<BackingStore> backing_store)
       : marked_(false),
         young_gc_state_(GcState::Dead),
         backing_store_(backing_store),
-        next_(nullptr) {}
+        next_(nullptr),
+        accounting_length_(0) {}
 
   void Mark() { marked_.store(true, std::memory_order_relaxed); }
   void Unmark() { marked_.store(false, std::memory_order_relaxed); }
@@ -198,6 +189,12 @@ class ArrayBufferExtension : public Malloced {
   std::shared_ptr<BackingStore> backing_store() { return backing_store_; }
   BackingStore* backing_store_raw() { return backing_store_.get(); }
 
+  size_t accounting_length() { return accounting_length_; }
+
+  void set_accounting_length(size_t accounting_length) {
+    accounting_length_ = accounting_length;
+  }
+
   std::shared_ptr<BackingStore> RemoveBackingStore() {
     return std::move(backing_store_);
   }
diff --git a/deps/v8/src/objects/js-array-buffer.tq b/deps/v8/src/objects/js-array-buffer.tq
index 92c004d653..9f4f1ba377 100644
--- a/deps/v8/src/objects/js-array-buffer.tq
+++ b/deps/v8/src/objects/js-array-buffer.tq
@@ -2,9 +2,32 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+bitfield struct JSArrayBufferFlags extends uint32 {
+  is_external: bool: 1 bit;
+  is_detachable: bool: 1 bit;
+  was_detached: bool: 1 bit;
+  is_asm_js_memory: bool: 1 bit;
+  is_shared: bool: 1 bit;
+}
+
 extern class JSArrayBuffer extends JSObject {
   byte_length: uintptr;
   backing_store: RawPtr;
+  @if(V8_ARRAY_BUFFER_EXTENSION_BOOL) extension: RawPtr;
+  @ifnot(V8_ARRAY_BUFFER_EXTENSION_BOOL) extension: void;
+  bit_field: JSArrayBufferFlags;
+  // Pads header size to be a multiple of kTaggedSize.
+  @if(TAGGED_SIZE_8_BYTES) optional_padding: uint32;
+  @ifnot(TAGGED_SIZE_8_BYTES) optional_padding: void;
+}
+
+@export
+macro IsDetachedBuffer(buffer: JSArrayBuffer): bool {
+  return buffer.bit_field.was_detached;
+}
+
+macro IsSharedArrayBuffer(buffer: JSArrayBuffer): bool {
+  return buffer.bit_field.is_shared;
 }
 
 @abstract
diff --git a/deps/v8/src/objects/js-break-iterator-inl.h b/deps/v8/src/objects/js-break-iterator-inl.h
index 86e87ddb0d..0dd23edaa5 100644
--- a/deps/v8/src/objects/js-break-iterator-inl.h
+++ b/deps/v8/src/objects/js-break-iterator-inl.h
@@ -20,14 +20,6 @@ namespace internal {
 
 OBJECT_CONSTRUCTORS_IMPL(JSV8BreakIterator, JSObject)
 
-inline JSV8BreakIterator::Type JSV8BreakIterator::type() const {
-  return static_cast<JSV8BreakIterator::Type>(raw_type());
-}
-
-inline void JSV8BreakIterator::set_type(Type type) {
-  set_raw_type(static_cast<int>(type));
-}
-
 ACCESSORS(JSV8BreakIterator, locale, String, kLocaleOffset)
 ACCESSORS(JSV8BreakIterator, break_iterator, Managed<icu::BreakIterator>,
           kBreakIteratorOffset)
@@ -39,8 +31,6 @@ ACCESSORS(JSV8BreakIterator, bound_next, Object, kBoundNextOffset)
 ACCESSORS(JSV8BreakIterator, bound_current, Object, kBoundCurrentOffset)
 ACCESSORS(JSV8BreakIterator, bound_break_type, Object, kBoundBreakTypeOffset)
 
-SMI_ACCESSORS(JSV8BreakIterator, raw_type, kBreakIteratorTypeOffset)
-
 CAST_ACCESSOR(JSV8BreakIterator)
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/js-break-iterator.cc b/deps/v8/src/objects/js-break-iterator.cc
index 1a9d096411..28db1699f4 100644
--- a/deps/v8/src/objects/js-break-iterator.cc
+++ b/deps/v8/src/objects/js-break-iterator.cc
@@ -15,6 +15,10 @@
 namespace v8 {
 namespace internal {
 
+namespace {
+enum class Type { CHARACTER, WORD, SENTENCE, LINE };
+}  // anonymous namespace
+
 MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::New(
     Isolate* isolate, Handle<Map> map, Handle<Object> locales,
     Handle<Object> options_obj, const char* service) {
@@ -42,9 +46,14 @@ MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::New(
   MAYBE_RETURN(maybe_locale_matcher, MaybeHandle<JSV8BreakIterator>());
   Intl::MatcherOption matcher = maybe_locale_matcher.FromJust();
 
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSV8BreakIterator::GetAvailableLocales(),
                           requested_locales, matcher, {});
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSV8BreakIterator);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   // Extract type from options
   Maybe<Type> maybe_type = Intl::GetStringOption<Type>(
@@ -70,20 +79,24 @@ MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::New(
           icu::BreakIterator::createSentenceInstance(icu_locale, status));
       break;
     case Type::LINE:
+      isolate->CountUsage(
+          v8::Isolate::UseCounterFeature::kBreakIteratorTypeLine);
       break_iterator.reset(
           icu::BreakIterator::createLineInstance(icu_locale, status));
       break;
     default:
+      isolate->CountUsage(
+          v8::Isolate::UseCounterFeature::kBreakIteratorTypeWord);
       break_iterator.reset(
           icu::BreakIterator::createWordInstance(icu_locale, status));
       break;
   }
 
   // Error handling for break_iterator
-  if (U_FAILURE(status)) {
-    FATAL("Failed to create ICU break iterator, are ICU data files missing?");
+  if (U_FAILURE(status) || break_iterator.get() == nullptr) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSV8BreakIterator);
   }
-  CHECK_NOT_NULL(break_iterator.get());
   isolate->CountUsage(v8::Isolate::UseCounterFeature::kBreakIterator);
 
   // Construct managed objects from pointers
@@ -102,7 +115,6 @@ MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::New(
           isolate->factory()->NewFastOrSlowJSObjectFromMap(map));
   DisallowHeapAllocation no_gc;
   break_iterator_holder->set_locale(*locale_str);
-  break_iterator_holder->set_type(type_enum);
   break_iterator_holder->set_break_iterator(*managed_break_iterator);
   break_iterator_holder->set_unicode_string(*managed_unicode_string);
 
@@ -110,17 +122,68 @@ MaybeHandle<JSV8BreakIterator> JSV8BreakIterator::New(
   return break_iterator_holder;
 }
 
+namespace {
+
+Type GetType(icu::BreakIterator* break_iterator) {
+  // Since the developer calling the Intl.v8BreakIterator already know the type,
+  // we usually do not need to know the type unless the resolvedOptions() is
+  // called, we use the following trick to figure out the type instead of
+  // storing it with the JSV8BreakIterator object to save memory.
+  // This routine is not fast but should be seldomly used only.
+
+  // We need to clone a copy of break iteator because we need to setText to it.
+  std::unique_ptr<icu::BreakIterator> cloned_break_iterator(
+      break_iterator->clone());
+  // Use a magic string "He is." to call next().
+  //  character type: will return 1 for "H"
+  //  word type: will return 2 for "He"
+  //  line type: will return 3 for "He "
+  //  sentence type: will return 6 for "He is."
+  icu::UnicodeString data("He is.");
+  cloned_break_iterator->setText(data);
+  switch (cloned_break_iterator->next()) {
+    case 1:  // After "H"
+      return Type::CHARACTER;
+    case 2:  // After "He"
+      return Type::WORD;
+    case 3:  // After "He "
+      return Type::LINE;
+    case 6:  // After "He is."
+      return Type::SENTENCE;
+    default:
+      UNREACHABLE();
+  }
+}
+
+Handle<String> TypeAsString(Isolate* isolate, Type type) {
+  switch (type) {
+    case Type::CHARACTER:
+      return ReadOnlyRoots(isolate).character_string_handle();
+    case Type::WORD:
+      return ReadOnlyRoots(isolate).word_string_handle();
+    case Type::SENTENCE:
+      return ReadOnlyRoots(isolate).sentence_string_handle();
+    case Type::LINE:
+      return ReadOnlyRoots(isolate).line_string_handle();
+  }
+  UNREACHABLE();
+}
+
+}  // anonymous namespace
+
 Handle<JSObject> JSV8BreakIterator::ResolvedOptions(
     Isolate* isolate, Handle<JSV8BreakIterator> break_iterator) {
   Factory* factory = isolate->factory();
 
+  Type type = GetType(break_iterator->break_iterator().raw());
+
   Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
   Handle<String> locale(break_iterator->locale(), isolate);
 
   JSObject::AddProperty(isolate, result, factory->locale_string(), locale,
                         NONE);
   JSObject::AddProperty(isolate, result, factory->type_string(),
-                        break_iterator->TypeAsString(), NONE);
+                        TypeAsString(isolate, type), NONE);
   return result;
 }
 
@@ -135,20 +198,6 @@ void JSV8BreakIterator::AdoptText(
   break_iterator_holder->set_unicode_string(*unicode_string);
 }
 
-Handle<String> JSV8BreakIterator::TypeAsString() const {
-  switch (type()) {
-    case Type::CHARACTER:
-      return GetReadOnlyRoots().character_string_handle();
-    case Type::WORD:
-      return GetReadOnlyRoots().word_string_handle();
-    case Type::SENTENCE:
-      return GetReadOnlyRoots().sentence_string_handle();
-    case Type::LINE:
-      return GetReadOnlyRoots().line_string_handle();
-  }
-  UNREACHABLE();
-}
-
 Handle<Object> JSV8BreakIterator::Current(
     Isolate* isolate, Handle<JSV8BreakIterator> break_iterator) {
   return isolate->factory()->NewNumberFromInt(
diff --git a/deps/v8/src/objects/js-break-iterator.h b/deps/v8/src/objects/js-break-iterator.h
index ea66fe6732..e21fa9f0eb 100644
--- a/deps/v8/src/objects/js-break-iterator.h
+++ b/deps/v8/src/objects/js-break-iterator.h
@@ -51,12 +51,6 @@ class JSV8BreakIterator : public JSObject {
   static String BreakType(Isolate* isolate,
                           Handle<JSV8BreakIterator> break_iterator);
 
-  enum class Type { CHARACTER, WORD, SENTENCE, LINE };
-  inline void set_type(Type type);
-  inline Type type() const;
-
-  Handle<String> TypeAsString() const;
-
   DECL_CAST(JSV8BreakIterator)
   DECL_PRINTER(JSV8BreakIterator)
   DECL_VERIFIER(JSV8BreakIterator)
@@ -75,8 +69,6 @@ class JSV8BreakIterator : public JSObject {
                                 TORQUE_GENERATED_JS_V8_BREAK_ITERATOR_FIELDS)
 
  private:
-  DECL_INT_ACCESSORS(raw_type)
-
   OBJECT_CONSTRUCTORS(JSV8BreakIterator, JSObject);
 };
 
diff --git a/deps/v8/src/objects/js-collator.cc b/deps/v8/src/objects/js-collator.cc
index 39178b3acf..046fa25e3d 100644
--- a/deps/v8/src/objects/js-collator.cc
+++ b/deps/v8/src/objects/js-collator.cc
@@ -37,6 +37,17 @@ enum class Sensitivity {
   kUndefined,
 };
 
+// enum for "caseFirst" option.
+enum class CaseFirst { kUndefined, kUpper, kLower, kFalse };
+
+Maybe<CaseFirst> GetCaseFirst(Isolate* isolate, Handle<JSReceiver> options,
+                              const char* method) {
+  return Intl::GetStringOption<CaseFirst>(
+      isolate, options, "caseFirst", method, {"upper", "lower", "false"},
+      {CaseFirst::kUpper, CaseFirst::kLower, CaseFirst::kFalse},
+      CaseFirst::kUndefined);
+}
+
 // TODO(gsathya): Consider internalizing the value strings.
 void CreateDataPropertyForOptions(Isolate* isolate, Handle<JSObject> options,
                                   Handle<String> key, const char* value) {
@@ -202,21 +213,21 @@ Handle<JSObject> JSCollator::ResolvedOptions(Isolate* isolate,
 
 namespace {
 
-Intl::CaseFirst ToCaseFirst(const char* str) {
-  if (strcmp(str, "upper") == 0) return Intl::CaseFirst::kUpper;
-  if (strcmp(str, "lower") == 0) return Intl::CaseFirst::kLower;
-  if (strcmp(str, "false") == 0) return Intl::CaseFirst::kFalse;
-  return Intl::CaseFirst::kUndefined;
+CaseFirst ToCaseFirst(const char* str) {
+  if (strcmp(str, "upper") == 0) return CaseFirst::kUpper;
+  if (strcmp(str, "lower") == 0) return CaseFirst::kLower;
+  if (strcmp(str, "false") == 0) return CaseFirst::kFalse;
+  return CaseFirst::kUndefined;
 }
 
-UColAttributeValue ToUColAttributeValue(Intl::CaseFirst case_first) {
+UColAttributeValue ToUColAttributeValue(CaseFirst case_first) {
   switch (case_first) {
-    case Intl::CaseFirst::kUpper:
+    case CaseFirst::kUpper:
       return UCOL_UPPER_FIRST;
-    case Intl::CaseFirst::kLower:
+    case CaseFirst::kLower:
       return UCOL_LOWER_FIRST;
-    case Intl::CaseFirst::kFalse:
-    case Intl::CaseFirst::kUndefined:
+    case CaseFirst::kFalse:
+    case CaseFirst::kUndefined:
       return UCOL_OFF;
   }
 }
@@ -229,8 +240,7 @@ void SetNumericOption(icu::Collator* icu_collator, bool numeric) {
   CHECK(U_SUCCESS(status));
 }
 
-void SetCaseFirstOption(icu::Collator* icu_collator,
-                        Intl::CaseFirst case_first) {
+void SetCaseFirstOption(icu::Collator* icu_collator, CaseFirst case_first) {
   CHECK_NOT_NULL(icu_collator);
   UErrorCode status = U_ZERO_ERROR;
   icu_collator->setAttribute(UCOL_CASE_FIRST, ToUColAttributeValue(case_first),
@@ -300,10 +310,9 @@ MaybeHandle<JSCollator> JSCollator::New(Isolate* isolate, Handle<Map> map,
 
   // 14. Let caseFirst be ? GetOption(options, "caseFirst", "string",
   //     « "upper", "lower", "false" », undefined).
-  Maybe<Intl::CaseFirst> maybe_case_first =
-      Intl::GetCaseFirst(isolate, options, service);
+  Maybe<CaseFirst> maybe_case_first = GetCaseFirst(isolate, options, service);
   MAYBE_RETURN(maybe_case_first, MaybeHandle<JSCollator>());
-  Intl::CaseFirst case_first = maybe_case_first.FromJust();
+  CaseFirst case_first = maybe_case_first.FromJust();
 
   // The relevant unicode extensions accepted by Collator as specified here:
   // https://tc39.github.io/ecma402/#sec-intl-collator-internal-slots
@@ -314,9 +323,14 @@ MaybeHandle<JSCollator> JSCollator::New(Isolate* isolate, Handle<Map> map,
   // 17. Let r be ResolveLocale(%Collator%.[[AvailableLocales]],
   // requestedLocales, opt, %Collator%.[[RelevantExtensionKeys]],
   // localeData).
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSCollator::GetAvailableLocales(),
                           requested_locales, matcher, relevant_extension_keys);
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSCollator);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   // 18. Set collator.[[Locale]] to r.[[locale]].
   icu::Locale icu_locale = r.icu_locale;
@@ -364,11 +378,11 @@ MaybeHandle<JSCollator> JSCollator::New(Isolate* isolate, Handle<Map> map,
         icu::Collator::createInstance(no_extension_locale, status));
 
     if (U_FAILURE(status) || icu_collator.get() == nullptr) {
-      FATAL("Failed to create ICU collator, are ICU data files missing?");
+      THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                      JSCollator);
     }
   }
   DCHECK(U_SUCCESS(status));
-  CHECK_NOT_NULL(icu_collator.get());
 
   // 22. If relevantExtensionKeys contains "kn", then
   //     a. Set collator.[[Numeric]] to ! SameValue(r.[[kn]], "true").
@@ -392,7 +406,7 @@ MaybeHandle<JSCollator> JSCollator::New(Isolate* isolate, Handle<Map> map,
   // If the caseFirst value is passed in through the options object,
   // then we use it. Otherwise, we check if the caseFirst value is
   // passed in through the unicode extensions.
-  if (case_first != Intl::CaseFirst::kUndefined) {
+  if (case_first != CaseFirst::kUndefined) {
     SetCaseFirstOption(icu_collator.get(), case_first);
   } else {
     auto kf_extension_it = r.extensions.find("kf");
diff --git a/deps/v8/src/objects/js-date-time-format-inl.h b/deps/v8/src/objects/js-date-time-format-inl.h
index 3603a8ff4b..4ab9adb844 100644
--- a/deps/v8/src/objects/js-date-time-format-inl.h
+++ b/deps/v8/src/objects/js-date-time-format-inl.h
@@ -29,13 +29,13 @@ ACCESSORS(JSDateTimeFormat, icu_date_interval_format,
 ACCESSORS(JSDateTimeFormat, bound_format, Object, kBoundFormatOffset)
 SMI_ACCESSORS(JSDateTimeFormat, flags, kFlagsOffset)
 
-inline void JSDateTimeFormat::set_hour_cycle(Intl::HourCycle hour_cycle) {
+inline void JSDateTimeFormat::set_hour_cycle(HourCycle hour_cycle) {
   int hints = flags();
   hints = HourCycleBits::update(hints, hour_cycle);
   set_flags(hints);
 }
 
-inline Intl::HourCycle JSDateTimeFormat::hour_cycle() const {
+inline JSDateTimeFormat::HourCycle JSDateTimeFormat::hour_cycle() const {
   return HourCycleBits::decode(flags());
 }
 
diff --git a/deps/v8/src/objects/js-date-time-format.cc b/deps/v8/src/objects/js-date-time-format.cc
index 06925c68d2..5643ee57d5 100644
--- a/deps/v8/src/objects/js-date-time-format.cc
+++ b/deps/v8/src/objects/js-date-time-format.cc
@@ -34,6 +34,24 @@ namespace internal {
 
 namespace {
 
+JSDateTimeFormat::HourCycle ToHourCycle(const std::string& hc) {
+  if (hc == "h11") return JSDateTimeFormat::HourCycle::kH11;
+  if (hc == "h12") return JSDateTimeFormat::HourCycle::kH12;
+  if (hc == "h23") return JSDateTimeFormat::HourCycle::kH23;
+  if (hc == "h24") return JSDateTimeFormat::HourCycle::kH24;
+  return JSDateTimeFormat::HourCycle::kUndefined;
+}
+
+Maybe<JSDateTimeFormat::HourCycle> GetHourCycle(Isolate* isolate,
+                                                Handle<JSReceiver> options,
+                                                const char* method) {
+  return Intl::GetStringOption<JSDateTimeFormat::HourCycle>(
+      isolate, options, "hourCycle", method, {"h11", "h12", "h23", "h24"},
+      {JSDateTimeFormat::HourCycle::kH11, JSDateTimeFormat::HourCycle::kH12,
+       JSDateTimeFormat::HourCycle::kH23, JSDateTimeFormat::HourCycle::kH24},
+      JSDateTimeFormat::HourCycle::kUndefined);
+}
+
 class PatternMap {
  public:
   PatternMap(std::string pattern, std::string value)
@@ -210,29 +228,30 @@ DEFFINE_TRAIT(H24Trait, "kk", "k")
 DEFFINE_TRAIT(HDefaultTrait, "jj", "j")
 #undef DEFFINE_TRAIT
 
-const std::vector<PatternData>& GetPatternData(Intl::HourCycle hour_cycle) {
+const std::vector<PatternData>& GetPatternData(
+    JSDateTimeFormat::HourCycle hour_cycle) {
   switch (hour_cycle) {
-    case Intl::HourCycle::kH11: {
+    case JSDateTimeFormat::HourCycle::kH11: {
       static base::LazyInstance<Pattern, H11Trait>::type h11 =
           LAZY_INSTANCE_INITIALIZER;
       return h11.Pointer()->Get();
     }
-    case Intl::HourCycle::kH12: {
+    case JSDateTimeFormat::HourCycle::kH12: {
       static base::LazyInstance<Pattern, H12Trait>::type h12 =
           LAZY_INSTANCE_INITIALIZER;
       return h12.Pointer()->Get();
     }
-    case Intl::HourCycle::kH23: {
+    case JSDateTimeFormat::HourCycle::kH23: {
       static base::LazyInstance<Pattern, H23Trait>::type h23 =
           LAZY_INSTANCE_INITIALIZER;
       return h23.Pointer()->Get();
     }
-    case Intl::HourCycle::kH24: {
+    case JSDateTimeFormat::HourCycle::kH24: {
       static base::LazyInstance<Pattern, H24Trait>::type h24 =
           LAZY_INSTANCE_INITIALIZER;
       return h24.Pointer()->Get();
     }
-    case Intl::HourCycle::kUndefined: {
+    case JSDateTimeFormat::HourCycle::kUndefined: {
       static base::LazyInstance<Pattern, HDefaultTrait>::type hDefault =
           LAZY_INSTANCE_INITIALIZER;
       return hDefault.Pointer()->Get();
@@ -320,10 +339,9 @@ std::string ToTitleCaseTimezoneLocation(Isolate* isolate,
   return title_cased;
 }
 
-}  // namespace
-
-std::string JSDateTimeFormat::CanonicalizeTimeZoneID(Isolate* isolate,
-                                                     const std::string& input) {
+// Return the time zone id which match ICU's expectation of title casing
+// return empty string when error.
+std::string CanonicalizeTimeZoneID(Isolate* isolate, const std::string& input) {
   std::string upper = input;
   transform(upper.begin(), upper.end(), upper.begin(),
             LocaleIndependentAsciiToUpper);
@@ -344,8 +362,6 @@ std::string JSDateTimeFormat::CanonicalizeTimeZoneID(Isolate* isolate,
   return ToTitleCaseTimezoneLocation(isolate, input);
 }
 
-namespace {
-
 Handle<String> DateTimeStyleAsString(Isolate* isolate,
                                      JSDateTimeFormat::DateTimeStyle style) {
   switch (style) {
@@ -485,32 +501,32 @@ MaybeHandle<JSObject> JSDateTimeFormat::ResolvedOptions(
             .FromJust());
 
   // 5.b.i. Let hc be dtf.[[HourCycle]].
-  Intl::HourCycle hc = date_time_format->hour_cycle();
+  HourCycle hc = date_time_format->hour_cycle();
 
-  if (hc != Intl::HourCycle::kUndefined) {
+  if (hc != HourCycle::kUndefined) {
     CHECK(JSReceiver::CreateDataProperty(
               isolate, options, factory->hourCycle_string(),
               date_time_format->HourCycleAsString(), Just(kDontThrow))
               .FromJust());
     switch (hc) {
       //  ii. If hc is "h11" or "h12", let v be true.
-      case Intl::HourCycle::kH11:
-      case Intl::HourCycle::kH12:
+      case HourCycle::kH11:
+      case HourCycle::kH12:
         CHECK(JSReceiver::CreateDataProperty(
                   isolate, options, factory->hour12_string(),
                   factory->true_value(), Just(kDontThrow))
                   .FromJust());
         break;
       // iii. Else if, hc is "h23" or "h24", let v be false.
-      case Intl::HourCycle::kH23:
-      case Intl::HourCycle::kH24:
+      case HourCycle::kH23:
+      case HourCycle::kH24:
         CHECK(JSReceiver::CreateDataProperty(
                   isolate, options, factory->hour12_string(),
                   factory->false_value(), Just(kDontThrow))
                   .FromJust());
         break;
       // iv. Else, let v be undefined.
-      case Intl::HourCycle::kUndefined:
+      case HourCycle::kUndefined:
         break;
     }
   }
@@ -860,8 +876,7 @@ std::unique_ptr<icu::TimeZone> CreateTimeZone(Isolate* isolate,
     // 19.a. Else / Let timeZone be DefaultTimeZone().
     return std::unique_ptr<icu::TimeZone>(icu::TimeZone::createDefault());
   }
-  std::string canonicalized =
-      JSDateTimeFormat::CanonicalizeTimeZoneID(isolate, timezone);
+  std::string canonicalized = CanonicalizeTimeZoneID(isolate, timezone);
   if (canonicalized.empty()) return std::unique_ptr<icu::TimeZone>();
   std::unique_ptr<icu::TimeZone> tz(
       icu::TimeZone::createTimeZone(canonicalized.c_str()));
@@ -925,21 +940,21 @@ icu::Calendar* CreateCalendar(Isolate* isolate, const icu::Locale& icu_locale,
 }
 
 icu::UnicodeString ReplaceHourCycleInPattern(icu::UnicodeString pattern,
-                                             Intl::HourCycle hc) {
+                                             JSDateTimeFormat::HourCycle hc) {
   char16_t replacement;
   switch (hc) {
-    case Intl::HourCycle::kUndefined:
+    case JSDateTimeFormat::HourCycle::kUndefined:
       return pattern;
-    case Intl::HourCycle::kH11:
+    case JSDateTimeFormat::HourCycle::kH11:
       replacement = 'K';
       break;
-    case Intl::HourCycle::kH12:
+    case JSDateTimeFormat::HourCycle::kH12:
       replacement = 'h';
       break;
-    case Intl::HourCycle::kH23:
+    case JSDateTimeFormat::HourCycle::kH23:
       replacement = 'H';
       break;
-    case Intl::HourCycle::kH24:
+    case JSDateTimeFormat::HourCycle::kH24:
       replacement = 'k';
       break;
   }
@@ -971,7 +986,7 @@ icu::UnicodeString ReplaceHourCycleInPattern(icu::UnicodeString pattern,
 
 std::unique_ptr<icu::SimpleDateFormat> CreateICUDateFormat(
     const icu::Locale& icu_locale, const icu::UnicodeString& skeleton,
-    icu::DateTimePatternGenerator* generator, Intl::HourCycle hc) {
+    icu::DateTimePatternGenerator* generator, JSDateTimeFormat::HourCycle hc) {
   // See https://github.com/tc39/ecma402/issues/225 . The best pattern
   // generation needs to be done in the base locale according to the
   // current spec however odd it may be. See also crbug.com/826549 .
@@ -1005,7 +1020,7 @@ class DateFormatCache {
   icu::SimpleDateFormat* Create(const icu::Locale& icu_locale,
                                 const icu::UnicodeString& skeleton,
                                 icu::DateTimePatternGenerator* generator,
-                                Intl::HourCycle hc) {
+                                JSDateTimeFormat::HourCycle hc) {
     std::string key;
     skeleton.toUTF8String<std::string>(key);
     key += ":";
@@ -1034,7 +1049,7 @@ class DateFormatCache {
 
 std::unique_ptr<icu::SimpleDateFormat> CreateICUDateFormatFromCache(
     const icu::Locale& icu_locale, const icu::UnicodeString& skeleton,
-    icu::DateTimePatternGenerator* generator, Intl::HourCycle hc) {
+    icu::DateTimePatternGenerator* generator, JSDateTimeFormat::HourCycle hc) {
   static base::LazyInstance<DateFormatCache>::type cache =
       LAZY_INSTANCE_INITIALIZER;
   return std::unique_ptr<icu::SimpleDateFormat>(
@@ -1078,7 +1093,8 @@ icu::DateIntervalFormat* LazyCreateDateIntervalFormat(
   return (*managed_interval_format).raw();
 }
 
-Intl::HourCycle HourCycleFromPattern(const icu::UnicodeString pattern) {
+JSDateTimeFormat::HourCycle HourCycleFromPattern(
+    const icu::UnicodeString pattern) {
   bool in_quote = false;
   for (int32_t i = 0; i < pattern.length(); i++) {
     char16_t ch = pattern[i];
@@ -1087,20 +1103,20 @@ Intl::HourCycle HourCycleFromPattern(const icu::UnicodeString pattern) {
         in_quote = !in_quote;
         break;
       case 'K':
-        if (!in_quote) return Intl::HourCycle::kH11;
+        if (!in_quote) return JSDateTimeFormat::HourCycle::kH11;
         break;
       case 'h':
-        if (!in_quote) return Intl::HourCycle::kH12;
+        if (!in_quote) return JSDateTimeFormat::HourCycle::kH12;
         break;
       case 'H':
-        if (!in_quote) return Intl::HourCycle::kH23;
+        if (!in_quote) return JSDateTimeFormat::HourCycle::kH23;
         break;
       case 'k':
-        if (!in_quote) return Intl::HourCycle::kH24;
+        if (!in_quote) return JSDateTimeFormat::HourCycle::kH24;
         break;
     }
   }
-  return Intl::HourCycle::kUndefined;
+  return JSDateTimeFormat::HourCycle::kUndefined;
 }
 
 icu::DateFormat::EStyle DateTimeStyleToEStyle(
@@ -1120,23 +1136,23 @@ icu::DateFormat::EStyle DateTimeStyleToEStyle(
 }
 
 icu::UnicodeString ReplaceSkeleton(const icu::UnicodeString input,
-                                   Intl::HourCycle hc) {
+                                   JSDateTimeFormat::HourCycle hc) {
   icu::UnicodeString result;
   char16_t to;
   switch (hc) {
-    case Intl::HourCycle::kH11:
+    case JSDateTimeFormat::HourCycle::kH11:
       to = 'K';
       break;
-    case Intl::HourCycle::kH12:
+    case JSDateTimeFormat::HourCycle::kH12:
       to = 'h';
       break;
-    case Intl::HourCycle::kH23:
+    case JSDateTimeFormat::HourCycle::kH23:
       to = 'H';
       break;
-    case Intl::HourCycle::kH24:
+    case JSDateTimeFormat::HourCycle::kH24:
       to = 'k';
       break;
-    case Intl::HourCycle::kUndefined:
+    case JSDateTimeFormat::HourCycle::kUndefined:
       UNREACHABLE();
   }
   for (int32_t i = 0; i < input.length(); i++) {
@@ -1170,7 +1186,7 @@ icu::UnicodeString ReplaceSkeleton(const icu::UnicodeString input,
 std::unique_ptr<icu::SimpleDateFormat> DateTimeStylePattern(
     JSDateTimeFormat::DateTimeStyle date_style,
     JSDateTimeFormat::DateTimeStyle time_style, const icu::Locale& icu_locale,
-    Intl::HourCycle hc, icu::DateTimePatternGenerator* generator) {
+    JSDateTimeFormat::HourCycle hc, icu::DateTimePatternGenerator* generator) {
   std::unique_ptr<icu::SimpleDateFormat> result;
   if (date_style != JSDateTimeFormat::DateTimeStyle::kUndefined) {
     if (time_style != JSDateTimeFormat::DateTimeStyle::kUndefined) {
@@ -1340,15 +1356,14 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
 
   // 7. Let hourCycle be ? GetOption(options, "hourCycle", "string", « "h11",
   // "h12", "h23", "h24" », undefined).
-  Maybe<Intl::HourCycle> maybe_hour_cycle =
-      Intl::GetHourCycle(isolate, options, service);
+  Maybe<HourCycle> maybe_hour_cycle = GetHourCycle(isolate, options, service);
   MAYBE_RETURN(maybe_hour_cycle, MaybeHandle<JSDateTimeFormat>());
-  Intl::HourCycle hour_cycle = maybe_hour_cycle.FromJust();
+  HourCycle hour_cycle = maybe_hour_cycle.FromJust();
 
   // 8. If hour12 is not undefined, then
   if (maybe_get_hour12.FromJust()) {
     // a. Let hourCycle be null.
-    hour_cycle = Intl::HourCycle::kUndefined;
+    hour_cycle = HourCycle::kUndefined;
   }
   // 9. Set opt.[[hc]] to hourCycle.
 
@@ -1362,9 +1377,14 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
   //     requestedLocales, opt, %DateTimeFormat%.[[RelevantExtensionKeys]],
   //     localeData).
   //
-  Intl::ResolvedLocale r = Intl::ResolveLocale(
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale = Intl::ResolveLocale(
       isolate, JSDateTimeFormat::GetAvailableLocales(), requested_locales,
       locale_matcher, relevant_extension_keys);
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSDateTimeFormat);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   icu::Locale icu_locale = r.icu_locale;
   DCHECK(!icu_locale.isBogus());
@@ -1441,20 +1461,20 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
   // 15.Let hcDefault be dataLocaleData.[[hourCycle]].
   icu::UnicodeString hour_pattern = generator->getBestPattern("jjmm", status);
   CHECK(U_SUCCESS(status));
-  Intl::HourCycle hc_default = HourCycleFromPattern(hour_pattern);
+  HourCycle hc_default = HourCycleFromPattern(hour_pattern);
 
   // 16.Let hc be r.[[hc]].
-  Intl::HourCycle hc = Intl::HourCycle::kUndefined;
-  if (hour_cycle == Intl::HourCycle::kUndefined) {
+  HourCycle hc = HourCycle::kUndefined;
+  if (hour_cycle == HourCycle::kUndefined) {
     auto hc_extension_it = r.extensions.find("hc");
     if (hc_extension_it != r.extensions.end()) {
-      hc = Intl::ToHourCycle(hc_extension_it->second.c_str());
+      hc = ToHourCycle(hc_extension_it->second.c_str());
     }
   } else {
     hc = hour_cycle;
   }
   // 17. If hc is null, then
-  if (hc == Intl::HourCycle::kUndefined) {
+  if (hc == HourCycle::kUndefined) {
     // a. Set hc to hcDefault.
     hc = hc_default;
   }
@@ -1464,26 +1484,24 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
     // a. If hour12 is true, then
     if (hour12) {
       // i. If hcDefault is "h11" or "h23", then
-      if (hc_default == Intl::HourCycle::kH11 ||
-          hc_default == Intl::HourCycle::kH23) {
+      if (hc_default == HourCycle::kH11 || hc_default == HourCycle::kH23) {
         // 1. Set hc to "h11".
-        hc = Intl::HourCycle::kH11;
+        hc = HourCycle::kH11;
         // ii. Else,
       } else {
         // 1. Set hc to "h12".
-        hc = Intl::HourCycle::kH12;
+        hc = HourCycle::kH12;
       }
       // b. Else,
     } else {
       // ii. If hcDefault is "h11" or "h23", then
-      if (hc_default == Intl::HourCycle::kH11 ||
-          hc_default == Intl::HourCycle::kH23) {
+      if (hc_default == HourCycle::kH11 || hc_default == HourCycle::kH23) {
         // 1. Set hc to "h23".
-        hc = Intl::HourCycle::kH23;
+        hc = HourCycle::kH23;
         // iii. Else,
       } else {
         // 1. Set hc to "h24".
-        hc = Intl::HourCycle::kH24;
+        hc = HourCycle::kH24;
       }
     }
   }
@@ -1522,6 +1540,10 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
   // 32. If dateStyle or timeStyle are not undefined, then
   if (date_style != DateTimeStyle::kUndefined ||
       time_style != DateTimeStyle::kUndefined) {
+    // Track newer feature dateStyle/timeStyle option.
+    isolate->CountUsage(
+        v8::Isolate::UseCounterFeature::kDateTimeFormatDateTimeStyle);
+
     icu_date_format = DateTimeStylePattern(date_style, time_style, icu_locale,
                                            hc, generator.get());
   }
@@ -1583,14 +1605,15 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
       icu_date_format = CreateICUDateFormatFromCache(icu_locale, skeleton_ustr,
                                                      generator.get(), hc);
       if (icu_date_format.get() == nullptr) {
-        FATAL("Failed to create ICU date format, are ICU data files missing?");
+        THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                        JSDateTimeFormat);
       }
     }
 
     // g. If dateTimeFormat.[[Hour]] is not undefined, then
     if (!has_hour_option) {
       // h. Else, i. Set dateTimeFormat.[[HourCycle]] to undefined.
-      hc = Intl::HourCycle::kUndefined;
+      hc = HourCycle::kUndefined;
     }
   }
 
@@ -1613,10 +1636,10 @@ MaybeHandle<JSDateTimeFormat> JSDateTimeFormat::New(
   //
   // See details in https://github.com/tc39/test262/pull/2035
   if (maybe_get_hour12.FromJust() ||
-      maybe_hour_cycle.FromJust() != Intl::HourCycle::kUndefined) {
+      maybe_hour_cycle.FromJust() != HourCycle::kUndefined) {
     auto hc_extension_it = r.extensions.find("hc");
     if (hc_extension_it != r.extensions.end()) {
-      if (hc != Intl::ToHourCycle(hc_extension_it->second.c_str())) {
+      if (hc != ToHourCycle(hc_extension_it->second.c_str())) {
         // Remove -hc- if it does not agree with what we used.
         UErrorCode status = U_ZERO_ERROR;
         resolved_locale.setUnicodeKeywordValue("hc", nullptr, status);
@@ -1790,15 +1813,15 @@ const std::set<std::string>& JSDateTimeFormat::GetAvailableLocales() {
 
 Handle<String> JSDateTimeFormat::HourCycleAsString() const {
   switch (hour_cycle()) {
-    case Intl::HourCycle::kUndefined:
+    case HourCycle::kUndefined:
       return GetReadOnlyRoots().undefined_string_handle();
-    case Intl::HourCycle::kH11:
+    case HourCycle::kH11:
       return GetReadOnlyRoots().h11_string_handle();
-    case Intl::HourCycle::kH12:
+    case HourCycle::kH12:
       return GetReadOnlyRoots().h12_string_handle();
-    case Intl::HourCycle::kH23:
+    case HourCycle::kH23:
       return GetReadOnlyRoots().h23_string_handle();
-    case Intl::HourCycle::kH24:
+    case HourCycle::kH24:
       return GetReadOnlyRoots().h24_string_handle();
     default:
       UNREACHABLE();
@@ -1929,6 +1952,9 @@ MaybeHandle<T> FormatRangeCommon(
     Isolate* isolate, Handle<JSDateTimeFormat> date_time_format, double x,
     double y,
     MaybeHandle<T> (*formatToResult)(Isolate*, const icu::FormattedValue&)) {
+  // Track newer feature formateRange and formatRangeToParts
+  isolate->CountUsage(v8::Isolate::UseCounterFeature::kDateTimeFormatRange);
+
   // #sec-partitiondatetimerangepattern
   // 1. Let x be TimeClip(x).
   x = DateCache::TimeClip(x);
diff --git a/deps/v8/src/objects/js-date-time-format.h b/deps/v8/src/objects/js-date-time-format.h
index ae3783f246..ef50b71dc9 100644
--- a/deps/v8/src/objects/js-date-time-format.h
+++ b/deps/v8/src/objects/js-date-time-format.h
@@ -48,11 +48,6 @@ class JSDateTimeFormat : public JSObject {
   static Maybe<std::string> OptionsToSkeleton(Isolate* isolate,
                                               Handle<JSReceiver> options);
 
-  // Return the time zone id which match ICU's expectation of title casing
-  // return empty string when error.
-  static std::string CanonicalizeTimeZoneID(Isolate* isolate,
-                                            const std::string& input);
-
   // ecma402/#sec-datetime-format-functions
   // DateTime Format Functions
   V8_WARN_UNUSED_RESULT static MaybeHandle<String> DateTimeFormat(
@@ -98,8 +93,11 @@ class JSDateTimeFormat : public JSObject {
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
                                 TORQUE_GENERATED_JS_DATE_TIME_FORMAT_FIELDS)
 
-  inline void set_hour_cycle(Intl::HourCycle hour_cycle);
-  inline Intl::HourCycle hour_cycle() const;
+  // enum for "hourCycle" option.
+  enum class HourCycle { kUndefined, kH11, kH12, kH23, kH24 };
+
+  inline void set_hour_cycle(HourCycle hour_cycle);
+  inline HourCycle hour_cycle() const;
 
   inline void set_date_style(DateTimeStyle date_style);
   inline DateTimeStyle date_style() const;
@@ -107,20 +105,14 @@ class JSDateTimeFormat : public JSObject {
   inline void set_time_style(DateTimeStyle time_style);
   inline DateTimeStyle time_style() const;
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _)            \
-  V(HourCycleBits, Intl::HourCycle, 3, _) \
-  V(DateStyleBits, DateTimeStyle, 3, _)   \
-  V(TimeStyleBits, DateTimeStyle, 3, _)
-
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_DATE_TIME_FORMAT_FLAGS()
 
-  STATIC_ASSERT(Intl::HourCycle::kUndefined <= HourCycleBits::kMax);
-  STATIC_ASSERT(Intl::HourCycle::kH11 <= HourCycleBits::kMax);
-  STATIC_ASSERT(Intl::HourCycle::kH12 <= HourCycleBits::kMax);
-  STATIC_ASSERT(Intl::HourCycle::kH23 <= HourCycleBits::kMax);
-  STATIC_ASSERT(Intl::HourCycle::kH24 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::kUndefined <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::kH11 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::kH12 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::kH23 <= HourCycleBits::kMax);
+  STATIC_ASSERT(HourCycle::kH24 <= HourCycleBits::kMax);
 
   STATIC_ASSERT(DateTimeStyle::kUndefined <= DateStyleBits::kMax);
   STATIC_ASSERT(DateTimeStyle::kFull <= DateStyleBits::kMax);
diff --git a/deps/v8/src/objects/js-display-names-inl.h b/deps/v8/src/objects/js-display-names-inl.h
index 08ad7c0838..103f3b388c 100644
--- a/deps/v8/src/objects/js-display-names-inl.h
+++ b/deps/v8/src/objects/js-display-names-inl.h
@@ -37,14 +37,14 @@ inline JSDisplayNames::Style JSDisplayNames::style() const {
 }
 
 inline void JSDisplayNames::set_fallback(Fallback fallback) {
-  DCHECK_GE(FallbackBits::kMax, fallback);
+  DCHECK_GE(FallbackBit::kMax, fallback);
   int hints = flags();
-  hints = FallbackBits::update(hints, fallback);
+  hints = FallbackBit::update(hints, fallback);
   set_flags(hints);
 }
 
 inline JSDisplayNames::Fallback JSDisplayNames::fallback() const {
-  return FallbackBits::decode(flags());
+  return FallbackBit::decode(flags());
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/js-display-names.cc b/deps/v8/src/objects/js-display-names.cc
index 6350d5e98b..95f4641173 100644
--- a/deps/v8/src/objects/js-display-names.cc
+++ b/deps/v8/src/objects/js-display-names.cc
@@ -31,6 +31,7 @@
 namespace v8 {
 namespace internal {
 
+namespace {
 // Type: identifying the types of the display names.
 //
 // ecma402/#sec-properties-of-intl-displaynames-instances
@@ -70,6 +71,8 @@ UDisplayContext ToUDisplayContext(JSDisplayNames::Style style) {
   }
 }
 
+}  // anonymous namespace
+
 // Abstract class for all different types.
 class DisplayNamesInternal {
  public:
@@ -82,6 +85,8 @@ class DisplayNamesInternal {
   virtual const char* calendar() const { return nullptr; }
 };
 
+namespace {
+
 class LocaleDisplayNamesCommon : public DisplayNamesInternal {
  public:
   LocaleDisplayNamesCommon(const icu::Locale& locale,
@@ -474,6 +479,9 @@ DisplayNamesInternal* CreateInternal(const icu::Locale& locale,
       UNREACHABLE();
   }
 }
+
+}  // anonymous namespace
+
 // ecma402 #sec-Intl.DisplayNames
 MaybeHandle<JSDisplayNames> JSDisplayNames::New(Isolate* isolate,
                                                 Handle<Map> map,
@@ -548,11 +556,16 @@ MaybeHandle<JSDisplayNames> JSDisplayNames::New(Isolate* isolate,
   std::set<std::string> relevant_extension_keys = {};
   // 13. Let r be ResolveLocale(%DisplayNames%.[[AvailableLocales]],
   //     requestedLocales, opt, %DisplayNames%.[[RelevantExtensionKeys]]).
-  Intl::ResolvedLocale r = Intl::ResolveLocale(
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale = Intl::ResolveLocale(
       isolate, JSDisplayNames::GetAvailableLocales(), requested_locales,
       matcher,
       FLAG_harmony_intl_displaynames_date_types ? relevant_extension_keys_ca
                                                 : relevant_extension_keys);
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSDisplayNames);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   icu::Locale icu_locale = r.icu_locale;
   UErrorCode status = U_ZERO_ERROR;
diff --git a/deps/v8/src/objects/js-display-names.h b/deps/v8/src/objects/js-display-names.h
index f3fc9c9282..c656a25779 100644
--- a/deps/v8/src/objects/js-display-names.h
+++ b/deps/v8/src/objects/js-display-names.h
@@ -67,18 +67,14 @@ class JSDisplayNames : public JSObject {
 
   DECL_CAST(JSDisplayNames)
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) \
-  V(StyleBits, Style, 2, _)    \
-  V(FallbackBits, Fallback, 1, _)
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_DISPLAY_NAMES_FLAGS()
 
   STATIC_ASSERT(Style::kLong <= StyleBits::kMax);
   STATIC_ASSERT(Style::kShort <= StyleBits::kMax);
   STATIC_ASSERT(Style::kNarrow <= StyleBits::kMax);
-  STATIC_ASSERT(Fallback::kCode <= FallbackBits::kMax);
-  STATIC_ASSERT(Fallback::kNone <= FallbackBits::kMax);
+  STATIC_ASSERT(Fallback::kCode <= FallbackBit::kMax);
+  STATIC_ASSERT(Fallback::kNone <= FallbackBit::kMax);
 
   // [flags] Bit field containing various flags about the function.
   DECL_INT_ACCESSORS(flags)
diff --git a/deps/v8/src/objects/js-generator-inl.h b/deps/v8/src/objects/js-generator-inl.h
index e3c57198c4..2d5e9fe03e 100644
--- a/deps/v8/src/objects/js-generator-inl.h
+++ b/deps/v8/src/objects/js-generator-inl.h
@@ -21,11 +21,6 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(JSAsyncFunctionObject)
 TQ_OBJECT_CONSTRUCTORS_IMPL(JSAsyncGeneratorObject)
 TQ_OBJECT_CONSTRUCTORS_IMPL(AsyncGeneratorRequest)
 
-TQ_SMI_ACCESSORS(JSGeneratorObject, resume_mode)
-TQ_SMI_ACCESSORS(JSGeneratorObject, continuation)
-
-TQ_SMI_ACCESSORS(AsyncGeneratorRequest, resume_mode)
-
 bool JSGeneratorObject::is_suspended() const {
   DCHECK_LT(kGeneratorExecuting, 0);
   DCHECK_LT(kGeneratorClosed, 0);
@@ -40,8 +35,6 @@ bool JSGeneratorObject::is_executing() const {
   return continuation() == kGeneratorExecuting;
 }
 
-TQ_SMI_ACCESSORS(JSAsyncGeneratorObject, is_awaiting)
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/js-generator.h b/deps/v8/src/objects/js-generator.h
index 12063c7335..bf35595fdd 100644
--- a/deps/v8/src/objects/js-generator.h
+++ b/deps/v8/src/objects/js-generator.h
@@ -20,17 +20,8 @@ class JSPromise;
 class JSGeneratorObject
     : public TorqueGeneratedJSGeneratorObject<JSGeneratorObject, JSObject> {
  public:
-  // [resume_mode]: The most recent resume mode.
   enum ResumeMode { kNext, kReturn, kThrow };
-  DECL_INT_ACCESSORS(resume_mode)
-
-  // [continuation]
-  //
-  // A positive value indicates a suspended generator.  The special
-  // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
-  // cannot be resumed.
-  inline int continuation() const;
-  inline void set_continuation(int continuation);
+
   inline bool is_closed() const;
   inline bool is_executing() const;
   inline bool is_suspended() const;
@@ -68,10 +59,6 @@ class JSAsyncGeneratorObject
   DECL_VERIFIER(JSAsyncGeneratorObject)
   DECL_PRINTER(JSAsyncGeneratorObject)
 
-  // [is_awaiting]
-  // Whether or not the generator is currently awaiting.
-  DECL_INT_ACCESSORS(is_awaiting)
-
   TQ_OBJECT_CONSTRUCTORS(JSAsyncGeneratorObject)
 };
 
@@ -79,8 +66,6 @@ class AsyncGeneratorRequest
     : public TorqueGeneratedAsyncGeneratorRequest<AsyncGeneratorRequest,
                                                   Struct> {
  public:
-  DECL_INT_ACCESSORS(resume_mode)
-
   DECL_PRINTER(AsyncGeneratorRequest)
   DECL_VERIFIER(AsyncGeneratorRequest)
 
diff --git a/deps/v8/src/objects/js-generator.tq b/deps/v8/src/objects/js-generator.tq
index bb8df21f0a..51725dc964 100644
--- a/deps/v8/src/objects/js-generator.tq
+++ b/deps/v8/src/objects/js-generator.tq
@@ -14,7 +14,12 @@ extern class JSGeneratorObject extends JSObject {
   // suspended generator.
   input_or_debug_pos: Object;
 
+  // The most recent resume mode.
   resume_mode: Smi;
+
+  // A positive value indicates a suspended generator.  The special
+  // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
+  // cannot be resumed.
   continuation: Smi;
 
   // Saved interpreter register file.
@@ -31,6 +36,7 @@ extern class JSAsyncGeneratorObject extends JSGeneratorObject {
   // Pointer to the head of a singly linked list of AsyncGeneratorRequest, or
   // undefined.
   queue: HeapObject;
+  // Whether or not the generator is currently awaiting.
   is_awaiting: Smi;
 }
 
diff --git a/deps/v8/src/objects/js-list-format.cc b/deps/v8/src/objects/js-list-format.cc
index 90ab9ebc43..978f0ea38f 100644
--- a/deps/v8/src/objects/js-list-format.cc
+++ b/deps/v8/src/objects/js-list-format.cc
@@ -75,38 +75,6 @@ const char* GetIcuStyleString(JSListFormat::Style style,
 
 }  // namespace
 
-JSListFormat::Style get_style(const char* str) {
-  switch (str[0]) {
-    case 'n':
-      if (strcmp(&str[1], "arrow") == 0) return JSListFormat::Style::NARROW;
-      break;
-    case 'l':
-      if (strcmp(&str[1], "ong") == 0) return JSListFormat::Style::LONG;
-      break;
-    case 's':
-      if (strcmp(&str[1], "hort") == 0) return JSListFormat::Style::SHORT;
-      break;
-  }
-  UNREACHABLE();
-}
-
-JSListFormat::Type get_type(const char* str) {
-  switch (str[0]) {
-    case 'c':
-      if (strcmp(&str[1], "onjunction") == 0)
-        return JSListFormat::Type::CONJUNCTION;
-      break;
-    case 'd':
-      if (strcmp(&str[1], "isjunction") == 0)
-        return JSListFormat::Type::DISJUNCTION;
-      break;
-    case 'u':
-      if (strcmp(&str[1], "nit") == 0) return JSListFormat::Type::UNIT;
-      break;
-  }
-  UNREACHABLE();
-}
-
 MaybeHandle<JSListFormat> JSListFormat::New(Isolate* isolate, Handle<Map> map,
                                             Handle<Object> locales,
                                             Handle<Object> input_options) {
@@ -144,9 +112,14 @@ MaybeHandle<JSListFormat> JSListFormat::New(Isolate* isolate, Handle<Map> map,
 
   // 10. Let r be ResolveLocale(%ListFormat%.[[AvailableLocales]],
   // requestedLocales, opt, undefined, localeData).
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSListFormat::GetAvailableLocales(),
                           requested_locales, matcher, {});
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSListFormat);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
   Handle<String> locale_str =
       isolate->factory()->NewStringFromAsciiChecked(r.locale.c_str());
 
@@ -171,11 +144,11 @@ MaybeHandle<JSListFormat> JSListFormat::New(Isolate* isolate, Handle<Map> map,
   UErrorCode status = U_ZERO_ERROR;
   icu::ListFormatter* formatter = icu::ListFormatter::createInstance(
       icu_locale, GetIcuStyleString(style_enum, type_enum), status);
-  if (U_FAILURE(status)) {
+  if (U_FAILURE(status) || formatter == nullptr) {
     delete formatter;
-    FATAL("Failed to create ICU list formatter, are ICU data files missing?");
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSListFormat);
   }
-  CHECK_NOT_NULL(formatter);
 
   Handle<Managed<icu::ListFormatter>> managed_formatter =
       Managed<icu::ListFormatter>::FromRawPtr(isolate, 0, formatter);
diff --git a/deps/v8/src/objects/js-list-format.h b/deps/v8/src/objects/js-list-format.h
index c2392969d3..0040bccb97 100644
--- a/deps/v8/src/objects/js-list-format.h
+++ b/deps/v8/src/objects/js-list-format.h
@@ -83,12 +83,8 @@ class JSListFormat : public JSObject {
   inline void set_type(Type type);
   inline Type type() const;
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) \
-  V(StyleBits, Style, 2, _)    \
-  V(TypeBits, Type, 2, _)
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_LIST_FORMAT_FLAGS()
 
   STATIC_ASSERT(Style::LONG <= StyleBits::kMax);
   STATIC_ASSERT(Style::SHORT <= StyleBits::kMax);
diff --git a/deps/v8/src/objects/js-number-format-inl.h b/deps/v8/src/objects/js-number-format-inl.h
index f373013e61..9cd16c35ed 100644
--- a/deps/v8/src/objects/js-number-format-inl.h
+++ b/deps/v8/src/objects/js-number-format-inl.h
@@ -21,25 +21,11 @@ namespace internal {
 OBJECT_CONSTRUCTORS_IMPL(JSNumberFormat, JSObject)
 
 ACCESSORS(JSNumberFormat, locale, String, kLocaleOffset)
-ACCESSORS(JSNumberFormat, numberingSystem, String, kNumberingSystemOffset)
 ACCESSORS(JSNumberFormat, icu_number_formatter,
           Managed<icu::number::LocalizedNumberFormatter>,
           kIcuNumberFormatterOffset)
 ACCESSORS(JSNumberFormat, bound_format, Object, kBoundFormatOffset)
 
-SMI_ACCESSORS(JSNumberFormat, flags, kFlagsOffset)
-
-inline void JSNumberFormat::set_style(Style style) {
-  DCHECK_GE(StyleBits::kMax, style);
-  int hints = flags();
-  hints = StyleBits::update(hints, style);
-  set_flags(hints);
-}
-
-inline JSNumberFormat::Style JSNumberFormat::style() const {
-  return StyleBits::decode(flags());
-}
-
 CAST_ACCESSOR(JSNumberFormat)
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/js-number-format.cc b/deps/v8/src/objects/js-number-format.cc
index ced408aa17..7d50f947f7 100644
--- a/deps/v8/src/objects/js-number-format.cc
+++ b/deps/v8/src/objects/js-number-format.cc
@@ -21,6 +21,7 @@
 #include "unicode/nounit.h"
 #include "unicode/numberformatter.h"
 #include "unicode/numfmt.h"
+#include "unicode/numsys.h"
 #include "unicode/ucurr.h"
 #include "unicode/uloc.h"
 #include "unicode/unumberformatter.h"
@@ -31,6 +32,10 @@ namespace internal {
 
 namespace {
 
+// [[Style]] is one of the values "decimal", "percent", "currency",
+// or "unit" identifying the style of the number format.
+enum class Style { DECIMAL, PERCENT, CURRENCY, UNIT };
+
 // [[CurrencyDisplay]] is one of the values "code", "symbol", "name",
 // or "narrowSymbol" identifying the display of the currency number format.
 enum class CurrencyDisplay {
@@ -305,15 +310,15 @@ bool IsWellFormedCurrencyCode(const std::string& currency) {
 }
 
 // Return the style as a String.
-Handle<String> StyleAsString(Isolate* isolate, JSNumberFormat::Style style) {
+Handle<String> StyleAsString(Isolate* isolate, Style style) {
   switch (style) {
-    case JSNumberFormat::Style::PERCENT:
+    case Style::PERCENT:
       return ReadOnlyRoots(isolate).percent_string_handle();
-    case JSNumberFormat::Style::CURRENCY:
+    case Style::CURRENCY:
       return ReadOnlyRoots(isolate).currency_string_handle();
-    case JSNumberFormat::Style::UNIT:
+    case Style::UNIT:
       return ReadOnlyRoots(isolate).unit_string_handle();
-    case JSNumberFormat::Style::DECIMAL:
+    case Style::DECIMAL:
       return ReadOnlyRoots(isolate).decimal_string_handle();
   }
   UNREACHABLE();
@@ -348,13 +353,25 @@ bool UseGroupingFromSkeleton(const icu::UnicodeString& skeleton) {
 
 // Parse currency code from skeleton. For example, skeleton as
 // "currency/TWD .00 rounding-mode-half-up unit-width-full-name;"
-std::string CurrencyFromSkeleton(const icu::UnicodeString& skeleton) {
-  std::string str;
-  str = skeleton.toUTF8String<std::string>(str);
-  std::string search("currency/");
-  size_t index = str.find(search);
-  if (index == str.npos) return "";
-  return str.substr(index + search.size(), 3);
+const icu::UnicodeString CurrencyFromSkeleton(
+    const icu::UnicodeString& skeleton) {
+  const char currency[] = "currency/";
+  int32_t index = skeleton.indexOf(currency);
+  if (index < 0) return "";
+  index += static_cast<int32_t>(std::strlen(currency));
+  return skeleton.tempSubString(index, 3);
+}
+
+const icu::UnicodeString NumberingSystemFromSkeleton(
+    const icu::UnicodeString& skeleton) {
+  const char numbering_system[] = "numbering-system/";
+  int32_t index = skeleton.indexOf(numbering_system);
+  if (index < 0) return "latn";
+  index += static_cast<int32_t>(std::strlen(numbering_system));
+  const icu::UnicodeString res = skeleton.tempSubString(index);
+  index = res.indexOf(" ");
+  if (index < 0) return res;
+  return res.tempSubString(0, index);
 }
 
 // Return CurrencySign as string based on skeleton.
@@ -553,13 +570,13 @@ namespace {
 std::string UnitFromSkeleton(const icu::UnicodeString& skeleton) {
   std::string str;
   str = skeleton.toUTF8String<std::string>(str);
-  // Special case for "percent" first.
-  if (str.find("percent") != str.npos) {
-    return "percent";
-  }
   std::string search("measure-unit/");
   size_t begin = str.find(search);
   if (begin == str.npos) {
+    // Special case for "percent".
+    if (str.find("percent") != str.npos) {
+      return "percent";
+    }
     return "";
   }
   // Skip the type (ex: "length").
@@ -611,6 +628,19 @@ std::string UnitFromSkeleton(const icu::UnicodeString& skeleton) {
   return result + "-per-" + str.substr(begin, end - begin);
 }
 
+Style StyleFromSkeleton(const icu::UnicodeString& skeleton) {
+  if (skeleton.indexOf("currency/") >= 0) {
+    return Style::CURRENCY;
+  }
+  if (skeleton.indexOf("measure-unit/") >= 0) {
+    return Style::UNIT;
+  }
+  if (skeleton.indexOf("percent ") >= 0) {
+    return Style::PERCENT;
+  }
+  return Style::DECIMAL;
+}
+
 }  // anonymous namespace
 
 icu::number::LocalizedNumberFormatter
@@ -656,8 +686,8 @@ Handle<JSObject> JSNumberFormat::ResolvedOptions(
   Handle<JSObject> options = factory->NewJSObject(isolate->object_function());
 
   Handle<String> locale = Handle<String>(number_format->locale(), isolate);
-  Handle<String> numberingSystem =
-      Handle<String>(number_format->numberingSystem(), isolate);
+  const icu::UnicodeString numberingSystem_ustr =
+      NumberingSystemFromSkeleton(skeleton);
   // 5. For each row of Table 4, except the header row, in table order, do
   // Table 4: Resolved Options of NumberFormat Instances
   //  Internal Slot                    Property
@@ -676,21 +706,25 @@ Handle<JSObject> JSNumberFormat::ResolvedOptions(
                                        factory->locale_string(), locale,
                                        Just(kDontThrow))
             .FromJust());
+  Handle<String> numberingSystem_string;
+  CHECK(Intl::ToString(isolate, numberingSystem_ustr)
+            .ToHandle(&numberingSystem_string));
   CHECK(JSReceiver::CreateDataProperty(isolate, options,
                                        factory->numberingSystem_string(),
-                                       numberingSystem, Just(kDontThrow))
+                                       numberingSystem_string, Just(kDontThrow))
             .FromJust());
-  JSNumberFormat::Style style = number_format->style();
+  Style style = StyleFromSkeleton(skeleton);
   CHECK(JSReceiver::CreateDataProperty(
             isolate, options, factory->style_string(),
             StyleAsString(isolate, style), Just(kDontThrow))
             .FromJust());
-  std::string currency = CurrencyFromSkeleton(skeleton);
-  if (!currency.empty()) {
-    CHECK(JSReceiver::CreateDataProperty(
-              isolate, options, factory->currency_string(),
-              factory->NewStringFromAsciiChecked(currency.c_str()),
-              Just(kDontThrow))
+  const icu::UnicodeString currency_ustr = CurrencyFromSkeleton(skeleton);
+  if (!currency_ustr.isEmpty()) {
+    Handle<String> currency_string;
+    CHECK(Intl::ToString(isolate, currency_ustr).ToHandle(&currency_string));
+    CHECK(JSReceiver::CreateDataProperty(isolate, options,
+                                         factory->currency_string(),
+                                         currency_string, Just(kDontThrow))
               .FromJust());
 
     CHECK(JSReceiver::CreateDataProperty(
@@ -703,20 +737,20 @@ Handle<JSObject> JSNumberFormat::ResolvedOptions(
               .FromJust());
   }
 
-    if (style == JSNumberFormat::Style::UNIT) {
-      std::string unit = UnitFromSkeleton(skeleton);
-      if (!unit.empty()) {
-        CHECK(JSReceiver::CreateDataProperty(
-                  isolate, options, factory->unit_string(),
-                  isolate->factory()->NewStringFromAsciiChecked(unit.c_str()),
-                  Just(kDontThrow))
-                  .FromJust());
-      }
+  if (style == Style::UNIT) {
+    std::string unit = UnitFromSkeleton(skeleton);
+    if (!unit.empty()) {
       CHECK(JSReceiver::CreateDataProperty(
-                isolate, options, factory->unitDisplay_string(),
-                UnitDisplayString(isolate, skeleton), Just(kDontThrow))
+                isolate, options, factory->unit_string(),
+                isolate->factory()->NewStringFromAsciiChecked(unit.c_str()),
+                Just(kDontThrow))
                 .FromJust());
     }
+    CHECK(JSReceiver::CreateDataProperty(
+              isolate, options, factory->unitDisplay_string(),
+              UnitDisplayString(isolate, skeleton), Just(kDontThrow))
+              .FromJust());
+  }
 
   CHECK(
       JSReceiver::CreateDataProperty(
@@ -857,9 +891,14 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   // requestedLocales, opt,  %NumberFormat%.[[RelevantExtensionKeys]],
   // localeData).
   std::set<std::string> relevant_extension_keys{"nu"};
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSNumberFormat::GetAvailableLocales(),
                           requested_locales, matcher, relevant_extension_keys);
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSNumberFormat);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   icu::Locale icu_locale = r.icu_locale;
   UErrorCode status = U_ZERO_ERROR;
@@ -884,9 +923,7 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
     CHECK(U_SUCCESS(status));
   }
 
-  Handle<String> numberingSystem_str =
-      isolate->factory()->NewStringFromAsciiChecked(
-          Intl::GetNumberingSystem(icu_locale).c_str());
+  std::string numbering_system = Intl::GetNumberingSystem(icu_locale);
 
   // 11. Let dataLocale be r.[[dataLocale]].
 
@@ -894,22 +931,31 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
       icu::number::NumberFormatter::withLocale(icu_locale)
           .roundingMode(UNUM_ROUND_HALFUP);
 
-  // 12. Let style be ? GetOption(options, "style", "string",  « "decimal",
+  // For 'latn' numbering system, skip the adoptSymbols which would cause
+  // 10.1%-13.7% of regression of JSTests/Intl-NewIntlNumberFormat
+  // See crbug/1052751 so we skip calling adoptSymbols and depending on the
+  // default instead.
+  if (!numbering_system.empty() && numbering_system != "latn") {
+    icu_number_formatter = icu_number_formatter.adoptSymbols(
+        icu::NumberingSystem::createInstanceByName(numbering_system.c_str(),
+                                                   status));
+    CHECK(U_SUCCESS(status));
+  }
+
+  // 3. Let style be ? GetOption(options, "style", "string",  « "decimal",
   // "percent", "currency", "unit" », "decimal").
 
-  Maybe<JSNumberFormat::Style> maybe_style =
-      Intl::GetStringOption<JSNumberFormat::Style>(
-          isolate, options, "style", service,
-          {"decimal", "percent", "currency", "unit"},
-          {JSNumberFormat::Style::DECIMAL, JSNumberFormat::Style::PERCENT,
-           JSNumberFormat::Style::CURRENCY, JSNumberFormat::Style::UNIT},
-          JSNumberFormat::Style::DECIMAL);
+  Maybe<Style> maybe_style = Intl::GetStringOption<Style>(
+      isolate, options, "style", service,
+      {"decimal", "percent", "currency", "unit"},
+      {Style::DECIMAL, Style::PERCENT, Style::CURRENCY, Style::UNIT},
+      Style::DECIMAL);
   MAYBE_RETURN(maybe_style, MaybeHandle<JSNumberFormat>());
-  JSNumberFormat::Style style = maybe_style.FromJust();
+  Style style = maybe_style.FromJust();
 
-  // 13. Set numberFormat.[[Style]] to style.
+  // 4. Set intlObj.[[Style]] to style.
 
-  // 14. Let currency be ? GetOption(options, "currency", "string", undefined,
+  // 5. Let currency be ? GetOption(options, "currency", "string", undefined,
   // undefined).
   std::unique_ptr<char[]> currency_cstr;
   const std::vector<const char*> empty_values = {};
@@ -918,11 +964,11 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   MAYBE_RETURN(found_currency, MaybeHandle<JSNumberFormat>());
 
   std::string currency;
-  // 15. If currency is not undefined, then
+  // 6. If currency is not undefined, then
   if (found_currency.FromJust()) {
     DCHECK_NOT_NULL(currency_cstr.get());
     currency = currency_cstr.get();
-    // 15. a. If the result of IsWellFormedCurrencyCode(currency) is false,
+    // 6. a. If the result of IsWellFormedCurrencyCode(currency) is false,
     // throw a RangeError exception.
     if (!IsWellFormedCurrencyCode(currency)) {
       THROW_NEW_ERROR(
@@ -934,25 +980,7 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
     }
   }
 
-  // 16. If style is "currency" and currency is undefined, throw a TypeError
-  // exception.
-  if (style == JSNumberFormat::Style::CURRENCY && !found_currency.FromJust()) {
-    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kCurrencyCode),
-                    JSNumberFormat);
-  }
-  // 17. If style is "currency", then
-  int c_digits = 0;
-  icu::UnicodeString currency_ustr;
-  if (style == JSNumberFormat::Style::CURRENCY) {
-    // a. Let currency be the result of converting currency to upper case as
-    //    specified in 6.1
-    std::transform(currency.begin(), currency.end(), currency.begin(), toupper);
-    // c. Let cDigits be CurrencyDigits(currency).
-    currency_ustr = currency.c_str();
-    c_digits = CurrencyDigits(currency_ustr);
-  }
-
-  // 18. Let currencyDisplay be ? GetOption(options, "currencyDisplay",
+  // 7. Let currencyDisplay be ? GetOption(options, "currencyDisplay",
   // "string", « "code",  "symbol", "name", "narrowSymbol" », "symbol").
   Maybe<CurrencyDisplay> maybe_currency_display =
       Intl::GetStringOption<CurrencyDisplay>(
@@ -965,7 +993,7 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   CurrencyDisplay currency_display = maybe_currency_display.FromJust();
 
   CurrencySign currency_sign = CurrencySign::STANDARD;
-  // Let currencySign be ? GetOption(options, "currencySign", "string", «
+  // 8. Let currencySign be ? GetOption(options, "currencySign", "string", «
   // "standard",  "accounting" », "standard").
   Maybe<CurrencySign> maybe_currency_sign = Intl::GetStringOption<CurrencySign>(
       isolate, options, "currencySign", service, {"standard", "accounting"},
@@ -974,7 +1002,8 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   MAYBE_RETURN(maybe_currency_sign, MaybeHandle<JSNumberFormat>());
   currency_sign = maybe_currency_sign.FromJust();
 
-  // Let unit be ? GetOption(options, "unit", "string", undefined, undefined).
+  // 9. Let unit be ? GetOption(options, "unit", "string", undefined,
+  // undefined).
   std::unique_ptr<char[]> unit_cstr;
   Maybe<bool> found_unit = Intl::GetStringOption(
       isolate, options, "unit", empty_values, service, &unit_cstr);
@@ -985,8 +1014,21 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
     DCHECK_NOT_NULL(unit_cstr.get());
     unit = unit_cstr.get();
   }
-
-  // Let unitDisplay be ? GetOption(options, "unitDisplay", "string", «
+  // 10. If unit is not undefined, then
+  // 10.a If the result of IsWellFormedUnitIdentifier(unit) is false, throw a
+  // RangeError exception.
+  Maybe<std::pair<icu::MeasureUnit, icu::MeasureUnit>> maybe_wellformed_unit =
+      IsWellFormedUnitIdentifier(isolate, unit);
+  if (found_unit.FromJust() && maybe_wellformed_unit.IsNothing()) {
+    THROW_NEW_ERROR(
+        isolate,
+        NewRangeError(MessageTemplate::kInvalidUnit,
+                      factory->NewStringFromAsciiChecked(service),
+                      factory->NewStringFromAsciiChecked(unit.c_str())),
+        JSNumberFormat);
+  }
+
+  // 11. Let unitDisplay be ? GetOption(options, "unitDisplay", "string", «
   // "short", "narrow", "long" »,  "short").
   Maybe<UnitDisplay> maybe_unit_display = Intl::GetStringOption<UnitDisplay>(
       isolate, options, "unitDisplay", service, {"short", "narrow", "long"},
@@ -995,9 +1037,46 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   MAYBE_RETURN(maybe_unit_display, MaybeHandle<JSNumberFormat>());
   UnitDisplay unit_display = maybe_unit_display.FromJust();
 
-  // If style is "unit", then
-  if (style == JSNumberFormat::Style::UNIT) {
-    // If unit is undefined, throw a TypeError exception.
+  // 12. If style is "currency", then
+  icu::UnicodeString currency_ustr;
+  if (style == Style::CURRENCY) {
+    // 12.a. If currency is undefined, throw a TypeError exception.
+    if (!found_currency.FromJust()) {
+      THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kCurrencyCode),
+                      JSNumberFormat);
+    }
+    // 12.b. Let currency be the result of converting currency to upper case as
+    //    specified in 6.1
+    std::transform(currency.begin(), currency.end(), currency.begin(), toupper);
+    currency_ustr = currency.c_str();
+
+    // 12.c. Set numberFormat.[[Currency]] to currency.
+    if (!currency_ustr.isEmpty()) {
+      Handle<String> currency_string;
+      ASSIGN_RETURN_ON_EXCEPTION(isolate, currency_string,
+                                 Intl::ToString(isolate, currency_ustr),
+                                 JSNumberFormat);
+
+      icu_number_formatter = icu_number_formatter.unit(
+          icu::CurrencyUnit(currency_ustr.getBuffer(), status));
+      CHECK(U_SUCCESS(status));
+      // 12.d Set intlObj.[[CurrencyDisplay]] to currencyDisplay.
+      // The default unitWidth is SHORT in ICU and that mapped from
+      // Symbol so we can skip the setting for optimization.
+      if (currency_display != CurrencyDisplay::SYMBOL) {
+        icu_number_formatter = icu_number_formatter.unitWidth(
+            ToUNumberUnitWidth(currency_display));
+      }
+      CHECK(U_SUCCESS(status));
+    }
+  }
+
+  // 13. If style is "unit", then
+  if (style == Style::UNIT) {
+    // Track newer style "unit".
+    isolate->CountUsage(v8::Isolate::UseCounterFeature::kNumberFormatStyleUnit);
+
+    // 13.a If unit is undefined, throw a TypeError exception.
     if (unit == "") {
       THROW_NEW_ERROR(isolate,
                       NewTypeError(MessageTemplate::kInvalidUnit,
@@ -1006,22 +1085,10 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
                       JSNumberFormat);
     }
 
-    // If the result of IsWellFormedUnitIdentifier(unit) is false, throw a
-    // RangeError exception.
-    Maybe<std::pair<icu::MeasureUnit, icu::MeasureUnit>> maybe_wellformed =
-        IsWellFormedUnitIdentifier(isolate, unit);
-    if (maybe_wellformed.IsNothing()) {
-      THROW_NEW_ERROR(
-          isolate,
-          NewRangeError(MessageTemplate::kInvalidUnit,
-                        factory->NewStringFromAsciiChecked(service),
-                        factory->NewStringFromAsciiChecked(unit.c_str())),
-          JSNumberFormat);
-    }
     std::pair<icu::MeasureUnit, icu::MeasureUnit> unit_pair =
-        maybe_wellformed.FromJust();
+        maybe_wellformed_unit.FromJust();
 
-    // Set intlObj.[[Unit]] to unit.
+    // 13.b Set intlObj.[[Unit]] to unit.
     if (unit_pair.first != icu::NoUnit::base()) {
       icu_number_formatter = icu_number_formatter.unit(unit_pair.first);
     }
@@ -1037,40 +1104,18 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
     }
   }
 
-  if (style == JSNumberFormat::Style::PERCENT) {
+  if (style == Style::PERCENT) {
     icu_number_formatter = icu_number_formatter.unit(icu::NoUnit::percent())
                                .scale(icu::number::Scale::powerOfTen(2));
   }
 
-  if (style == JSNumberFormat::Style::CURRENCY) {
-    // 19. If style is "currency", set  numberFormat.[[CurrencyDisplay]] to
-    // currencyDisplay.
-
-    // 17.b. Set numberFormat.[[Currency]] to currency.
-    if (!currency_ustr.isEmpty()) {
-      Handle<String> currency_string;
-      ASSIGN_RETURN_ON_EXCEPTION(isolate, currency_string,
-                                 Intl::ToString(isolate, currency_ustr),
-                                 JSNumberFormat);
-
-      icu_number_formatter = icu_number_formatter.unit(
-          icu::CurrencyUnit(currency_ustr.getBuffer(), status));
-      CHECK(U_SUCCESS(status));
-      // The default unitWidth is SHORT in ICU and that mapped from
-      // Symbol so we can skip the setting for optimization.
-      if (currency_display != CurrencyDisplay::SYMBOL) {
-        icu_number_formatter = icu_number_formatter.unitWidth(
-            ToUNumberUnitWidth(currency_display));
-      }
-      CHECK(U_SUCCESS(status));
-    }
-  }
-
   // 23. If style is "currency", then
   int mnfd_default, mxfd_default;
-  if (style == JSNumberFormat::Style::CURRENCY) {
-    //  a. Let mnfdDefault be cDigits.
-    //  b. Let mxfdDefault be cDigits.
+  if (style == Style::CURRENCY) {
+    // b. Let cDigits be CurrencyDigits(currency).
+    int c_digits = CurrencyDigits(currency_ustr);
+    // c. Let mnfdDefault be cDigits.
+    // d. Let mxfdDefault be cDigits.
     mnfd_default = c_digits;
     mxfd_default = c_digits;
     // 24. Else,
@@ -1078,7 +1123,7 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
     // a. Let mnfdDefault be 0.
     mnfd_default = 0;
     // b. If style is "percent", then
-    if (style == JSNumberFormat::Style::PERCENT) {
+    if (style == Style::PERCENT) {
       // i. Let mxfdDefault be 0.
       mxfd_default = 0;
     } else {
@@ -1184,10 +1229,7 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
   Handle<JSNumberFormat> number_format = Handle<JSNumberFormat>::cast(
       isolate->factory()->NewFastOrSlowJSObjectFromMap(map));
   DisallowHeapAllocation no_gc;
-  number_format->set_flags(0);
-  number_format->set_style(style);
   number_format->set_locale(*locale_str);
-  number_format->set_numberingSystem(*numberingSystem_str);
 
   number_format->set_icu_number_formatter(*managed_number_formatter);
   number_format->set_bound_format(*factory->undefined_value());
@@ -1197,31 +1239,44 @@ MaybeHandle<JSNumberFormat> JSNumberFormat::New(Isolate* isolate,
 }
 
 namespace {
-Maybe<bool> IcuFormatNumber(
+Maybe<icu::UnicodeString> IcuFormatNumber(
     Isolate* isolate,
     const icu::number::LocalizedNumberFormatter& number_format,
-    Handle<Object> numeric_obj, icu::number::FormattedNumber* formatted) {
+    Handle<Object> numeric_obj, icu::FieldPositionIterator* fp_iter) {
   // If it is BigInt, handle it differently.
   UErrorCode status = U_ZERO_ERROR;
+  icu::number::FormattedNumber formatted;
   if (numeric_obj->IsBigInt()) {
     Handle<BigInt> big_int = Handle<BigInt>::cast(numeric_obj);
     Handle<String> big_int_string;
     ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, big_int_string,
                                      BigInt::ToString(isolate, big_int),
-                                     Nothing<bool>());
-    *formatted = number_format.formatDecimal(
+                                     Nothing<icu::UnicodeString>());
+    formatted = number_format.formatDecimal(
         {big_int_string->ToCString().get(), big_int_string->length()}, status);
   } else {
-    double number = numeric_obj->Number();
-    *formatted = number_format.formatDouble(number, status);
+    double number = numeric_obj->IsNaN()
+                        ? std::numeric_limits<double>::quiet_NaN()
+                        : numeric_obj->Number();
+    formatted = number_format.formatDouble(number, status);
   }
   if (U_FAILURE(status)) {
     // This happen because of icu data trimming trim out "unit".
     // See https://bugs.chromium.org/p/v8/issues/detail?id=8641
-    THROW_NEW_ERROR_RETURN_VALUE(
-        isolate, NewTypeError(MessageTemplate::kIcuError), Nothing<bool>());
+    THROW_NEW_ERROR_RETURN_VALUE(isolate,
+                                 NewTypeError(MessageTemplate::kIcuError),
+                                 Nothing<icu::UnicodeString>());
+  }
+  if (fp_iter) {
+    formatted.getAllFieldPositions(*fp_iter, status);
+  }
+  icu::UnicodeString result = formatted.toString(status);
+  if (U_FAILURE(status)) {
+    THROW_NEW_ERROR_RETURN_VALUE(isolate,
+                                 NewTypeError(MessageTemplate::kIcuError),
+                                 Nothing<icu::UnicodeString>());
   }
-  return Just(true);
+  return Just(result);
 }
 
 }  // namespace
@@ -1232,16 +1287,10 @@ MaybeHandle<String> JSNumberFormat::FormatNumeric(
     Handle<Object> numeric_obj) {
   DCHECK(numeric_obj->IsNumeric());
 
-  icu::number::FormattedNumber formatted;
-  Maybe<bool> maybe_format =
-      IcuFormatNumber(isolate, number_format, numeric_obj, &formatted);
+  Maybe<icu::UnicodeString> maybe_format =
+      IcuFormatNumber(isolate, number_format, numeric_obj, nullptr);
   MAYBE_RETURN(maybe_format, Handle<String>());
-  UErrorCode status = U_ZERO_ERROR;
-  icu::UnicodeString result = formatted.toString(status);
-  if (U_FAILURE(status)) {
-    THROW_NEW_ERROR(isolate, NewTypeError(MessageTemplate::kIcuError), String);
-  }
-  return Intl::ToString(isolate, result);
+  return Intl::ToString(isolate, maybe_format.FromJust());
 }
 
 namespace {
@@ -1354,18 +1403,12 @@ std::vector<NumberFormatSpan> FlattenRegionsToParts(
 }
 
 namespace {
-Maybe<int> ConstructParts(Isolate* isolate,
-                          icu::number::FormattedNumber* formatted,
+Maybe<int> ConstructParts(Isolate* isolate, const icu::UnicodeString& formatted,
+                          icu::FieldPositionIterator* fp_iter,
                           Handle<JSArray> result, int start_index,
                           Handle<Object> numeric_obj, bool style_is_unit) {
-  UErrorCode status = U_ZERO_ERROR;
-  icu::UnicodeString formatted_text = formatted->toString(status);
-  if (U_FAILURE(status)) {
-    THROW_NEW_ERROR_RETURN_VALUE(
-        isolate, NewTypeError(MessageTemplate::kIcuError), Nothing<int>());
-  }
   DCHECK(numeric_obj->IsNumeric());
-  int32_t length = formatted_text.length();
+  int32_t length = formatted.length();
   int index = start_index;
   if (length == 0) return Just(index);
 
@@ -1374,14 +1417,13 @@ Maybe<int> ConstructParts(Isolate* isolate,
   // other region covers some part of the formatted string. It's possible
   // there's another field with exactly the same begin and end as this backdrop,
   // in which case the backdrop's field_id of -1 will give it lower priority.
-  regions.push_back(NumberFormatSpan(-1, 0, formatted_text.length()));
+  regions.push_back(NumberFormatSpan(-1, 0, formatted.length()));
 
   {
-    icu::ConstrainedFieldPosition cfp;
-    cfp.constrainCategory(UFIELD_CATEGORY_NUMBER);
-    while (formatted->nextPosition(cfp, status)) {
-      regions.push_back(
-          NumberFormatSpan(cfp.getField(), cfp.getStart(), cfp.getLimit()));
+    icu::FieldPosition fp;
+    while (fp_iter->next(fp)) {
+      regions.push_back(NumberFormatSpan(fp.getField(), fp.getBeginIndex(),
+                                         fp.getEndIndex()));
     }
   }
 
@@ -1403,7 +1445,7 @@ Maybe<int> ConstructParts(Isolate* isolate,
     Handle<String> substring;
     ASSIGN_RETURN_ON_EXCEPTION_VALUE(
         isolate, substring,
-        Intl::ToString(isolate, formatted_text, part.begin_pos, part.end_pos),
+        Intl::ToString(isolate, formatted, part.begin_pos, part.end_pos),
         Nothing<int>());
     Intl::AddElement(isolate, result, index, field_type_string, substring);
     ++index;
@@ -1423,15 +1465,20 @@ MaybeHandle<JSArray> JSNumberFormat::FormatToParts(
       number_format->icu_number_formatter().raw();
   CHECK_NOT_NULL(fmt);
 
-  icu::number::FormattedNumber formatted;
-  Maybe<bool> maybe_format =
-      IcuFormatNumber(isolate, *fmt, numeric_obj, &formatted);
+  icu::FieldPositionIterator fp_iter;
+  Maybe<icu::UnicodeString> maybe_format =
+      IcuFormatNumber(isolate, *fmt, numeric_obj, &fp_iter);
   MAYBE_RETURN(maybe_format, Handle<JSArray>());
 
+  UErrorCode status = U_ZERO_ERROR;
+  bool style_is_unit =
+      Style::UNIT == StyleFromSkeleton(fmt->toSkeleton(status));
+  CHECK(U_SUCCESS(status));
+
   Handle<JSArray> result = factory->NewJSArray(0);
-  Maybe<int> maybe_format_to_parts = ConstructParts(
-      isolate, &formatted, result, 0, numeric_obj,
-      number_format->style() == JSNumberFormat::Style::UNIT);
+  Maybe<int> maybe_format_to_parts =
+      ConstructParts(isolate, maybe_format.FromJust(), &fp_iter, result, 0,
+                     numeric_obj, style_is_unit);
   MAYBE_RETURN(maybe_format_to_parts, Handle<JSArray>());
 
   return result;
diff --git a/deps/v8/src/objects/js-number-format.h b/deps/v8/src/objects/js-number-format.h
index dd11564188..471398eafa 100644
--- a/deps/v8/src/objects/js-number-format.h
+++ b/deps/v8/src/objects/js-number-format.h
@@ -73,32 +73,11 @@ class JSNumberFormat : public JSObject {
   DECL_PRINTER(JSNumberFormat)
   DECL_VERIFIER(JSNumberFormat)
 
-  // [[Style]] is one of the values "decimal", "percent", "currency",
-  // or "unit" identifying the style of the number format.
-  // Note: "unit" is added in proposal-unified-intl-numberformat
-  enum class Style { DECIMAL, PERCENT, CURRENCY, UNIT };
-
-  inline void set_style(Style style);
-  inline Style style() const;
-
   // Layout description.
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
                                 TORQUE_GENERATED_JS_NUMBER_FORMAT_FIELDS)
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _)            \
-  V(StyleBits, Style, 2, _)
-
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
-
-  STATIC_ASSERT(Style::DECIMAL <= StyleBits::kMax);
-  STATIC_ASSERT(Style::PERCENT <= StyleBits::kMax);
-  STATIC_ASSERT(Style::CURRENCY <= StyleBits::kMax);
-  STATIC_ASSERT(Style::UNIT <= StyleBits::kMax);
-
   DECL_ACCESSORS(locale, String)
-  DECL_ACCESSORS(numberingSystem, String)
   DECL_ACCESSORS(icu_number_formatter,
                  Managed<icu::number::LocalizedNumberFormatter>)
   DECL_ACCESSORS(bound_format, Object)
diff --git a/deps/v8/src/objects/js-objects-inl.h b/deps/v8/src/objects/js-objects-inl.h
index 849aae4dc9..dd5ac09904 100644
--- a/deps/v8/src/objects/js-objects-inl.h
+++ b/deps/v8/src/objects/js-objects-inl.h
@@ -7,6 +7,7 @@
 
 #include "src/objects/js-objects.h"
 
+#include "src/diagnostics/code-tracer.h"
 #include "src/heap/heap-write-barrier.h"
 #include "src/objects/elements.h"
 #include "src/objects/embedder-data-slot-inl.h"
@@ -573,10 +574,12 @@ void JSFunction::set_shared(SharedFunctionInfo value, WriteBarrierMode mode) {
 void JSFunction::ClearOptimizedCodeSlot(const char* reason) {
   if (has_feedback_vector() && feedback_vector().has_optimized_code()) {
     if (FLAG_trace_opt) {
-      PrintF("[evicting entry from optimizing code feedback slot (%s) for ",
+      CodeTracer::Scope scope(GetIsolate()->GetCodeTracer());
+      PrintF(scope.file(),
+             "[evicting entry from optimizing code feedback slot (%s) for ",
              reason);
-      ShortPrint();
-      PrintF("]\n");
+      ShortPrint(scope.file());
+      PrintF(scope.file(), "]\n");
     }
     feedback_vector().ClearOptimizedCode();
   }
@@ -1023,8 +1026,6 @@ inline int JSGlobalProxy::SizeWithEmbedderFields(int embedder_field_count) {
 ACCESSORS(JSIteratorResult, value, Object, kValueOffset)
 ACCESSORS(JSIteratorResult, done, Object, kDoneOffset)
 
-TQ_SMI_ACCESSORS(JSStringIterator, index)
-
 // If the fast-case backing storage takes up much more memory than a dictionary
 // backing storage would, the object should have slow elements.
 // static
diff --git a/deps/v8/src/objects/js-objects.cc b/deps/v8/src/objects/js-objects.cc
index e3ea252693..13741c4f62 100644
--- a/deps/v8/src/objects/js-objects.cc
+++ b/deps/v8/src/objects/js-objects.cc
@@ -12,6 +12,7 @@
 #include "src/execution/isolate.h"
 #include "src/handles/handles-inl.h"
 #include "src/handles/maybe-handles.h"
+#include "src/heap/factory-inl.h"
 #include "src/heap/heap-inl.h"
 #include "src/ic/ic.h"
 #include "src/init/bootstrapper.h"
@@ -2137,10 +2138,10 @@ int JSObject::GetHeaderSize(InstanceType type,
       return JSMapIterator::kHeaderSize;
     case JS_WEAK_REF_TYPE:
       return JSWeakRef::kHeaderSize;
-    case JS_FINALIZATION_GROUP_TYPE:
-      return JSFinalizationGroup::kHeaderSize;
-    case JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE:
-      return JSFinalizationGroupCleanupIterator::kHeaderSize;
+    case JS_FINALIZATION_REGISTRY_TYPE:
+      return JSFinalizationRegistry::kHeaderSize;
+    case JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE:
+      return JSFinalizationRegistryCleanupIterator::kHeaderSize;
     case JS_WEAK_MAP_TYPE:
       return JSWeakMap::kHeaderSize;
     case JS_WEAK_SET_TYPE:
@@ -2376,7 +2377,7 @@ void JSObject::SetNormalizedProperty(Handle<JSObject> object, Handle<Name> name,
       int enumeration_index = original_details.dictionary_index();
       DCHECK_GT(enumeration_index, 0);
       details = details.set_index(enumeration_index);
-      dictionary->SetEntry(isolate, entry, *name, *value, details);
+      dictionary->SetEntry(entry, *name, *value, details);
     }
   }
 }
@@ -3375,7 +3376,7 @@ void JSObject::MigrateSlowToFast(Handle<JSObject> object,
     // Check that it really works.
     DCHECK(object->HasFastProperties());
     if (FLAG_trace_maps) {
-      LOG(isolate, MapEvent("SlowToFast", *old_map, *new_map, reason));
+      LOG(isolate, MapEvent("SlowToFast", old_map, new_map, reason));
     }
     return;
   }
@@ -3465,7 +3466,7 @@ void JSObject::MigrateSlowToFast(Handle<JSObject> object,
   }
 
   if (FLAG_trace_maps) {
-    LOG(isolate, MapEvent("SlowToFast", *old_map, *new_map, reason));
+    LOG(isolate, MapEvent("SlowToFast", old_map, new_map, reason));
   }
   // Transform the object.
   object->synchronized_set_map(*new_map);
@@ -3796,7 +3797,7 @@ void JSObject::ApplyAttributesToDictionary(
       if (v.IsAccessorPair()) attrs &= ~READ_ONLY;
     }
     details = details.CopyAddAttributes(static_cast<PropertyAttributes>(attrs));
-    dictionary->DetailsAtPut(isolate, i, details);
+    dictionary->DetailsAtPut(i, details);
   }
 }
 
@@ -4563,14 +4564,10 @@ void JSObject::SetImmutableProto(Handle<JSObject> object) {
 }
 
 void JSObject::EnsureCanContainElements(Handle<JSObject> object,
-                                        Arguments* args, uint32_t first_arg,
+                                        JavaScriptArguments* args,
                                         uint32_t arg_count,
                                         EnsureElementsMode mode) {
-  // Elements in |Arguments| are ordered backwards (because they're on the
-  // stack), but the method that's called here iterates over them in forward
-  // direction.
-  return EnsureCanContainElements(
-      object, args->slot_at(first_arg + arg_count - 1), arg_count, mode);
+  return EnsureCanContainElements(object, args->first_slot(), arg_count, mode);
 }
 
 void JSObject::ValidateElements(JSObject object) {
@@ -5038,6 +5035,7 @@ void JSFunction::EnsureFeedbackVector(Handle<JSFunction> function) {
   DCHECK(function->raw_feedback_cell() !=
          isolate->heap()->many_closures_cell());
   function->raw_feedback_cell().set_value(*feedback_vector);
+  function->raw_feedback_cell().SetInterruptBudget();
 }
 
 // static
@@ -5105,7 +5103,7 @@ void SetInstancePrototype(Isolate* isolate, Handle<JSFunction> function,
 
     // Deoptimize all code that embeds the previous initial map.
     initial_map->dependent_code().DeoptimizeDependentCodeGroup(
-        isolate, DependentCode::kInitialMapChangedGroup);
+        DependentCode::kInitialMapChangedGroup);
   } else {
     // Put the value in the initial map field until an initial map is
     // needed.  At that point, a new initial map is created and the
@@ -5168,8 +5166,9 @@ void JSFunction::SetInitialMap(Handle<JSFunction> function, Handle<Map> map,
   function->set_prototype_or_initial_map(*map);
   map->SetConstructor(*function);
   if (FLAG_trace_maps) {
-    LOG(function->GetIsolate(), MapEvent("InitialMap", Map(), *map, "",
-                                         function->shared().DebugName()));
+    LOG(function->GetIsolate(), MapEvent("InitialMap", Handle<Map>(), map, "",
+                                         handle(function->shared().DebugName(),
+                                                function->GetIsolate())));
   }
 }
 
@@ -5250,7 +5249,7 @@ bool CanSubclassHaveInobjectProperties(InstanceType instance_type) {
     case JS_MESSAGE_OBJECT_TYPE:
     case JS_OBJECT_TYPE:
     case JS_ERROR_TYPE:
-    case JS_FINALIZATION_GROUP_TYPE:
+    case JS_FINALIZATION_REGISTRY_TYPE:
     case JS_ARGUMENTS_OBJECT_TYPE:
     case JS_PROMISE_TYPE:
     case JS_REG_EXP_TYPE:
@@ -5347,8 +5346,15 @@ bool FastInitializeDerivedMap(Isolate* isolate, Handle<JSFunction> new_target,
   int in_object_properties;
   int embedder_fields =
       JSObject::GetEmbedderFieldCount(*constructor_initial_map);
+  // Constructor expects certain number of in-object properties to be in the
+  // object. However, CalculateExpectedNofProperties() may return smaller value
+  // if 1) the constructor is not in the prototype chain of new_target, or
+  // 2) the prototype chain is modified during iteration, or 3) compilation
+  // failure occur during prototype chain iteration.
+  // So we take the maximum of two values.
   int expected_nof_properties =
-      JSFunction::CalculateExpectedNofProperties(isolate, new_target);
+      Max(static_cast<int>(constructor->shared().expected_nof_properties()),
+          JSFunction::CalculateExpectedNofProperties(isolate, new_target));
   JSFunction::CalculateInstanceSizeHelper(
       instance_type, true, embedder_fields, expected_nof_properties,
       &instance_size, &in_object_properties);
@@ -5596,9 +5602,10 @@ int JSFunction::CalculateExpectedNofProperties(Isolate* isolate,
         return JSObject::kMaxInObjectProperties;
       }
     } else {
-      // In case there was a compilation error for the constructor we will
-      // throw an error during instantiation.
-      break;
+      // In case there was a compilation error proceed iterating in case there
+      // will be a builtin function in the prototype chain that requires
+      // certain number of in-object properties.
+      continue;
     }
   }
   // Inobject slack tracking will reclaim redundant inobject space
@@ -5890,7 +5897,7 @@ void JSMessageObject::EnsureSourcePositionsAvailable(
     Isolate* isolate, Handle<JSMessageObject> message) {
   if (!message->DidEnsureSourcePositionsAvailable()) {
     DCHECK_EQ(message->start_position(), -1);
-    DCHECK_GE(message->bytecode_offset().value(), 0);
+    DCHECK_GE(message->bytecode_offset().value(), kFunctionEntryBytecodeOffset);
     Handle<SharedFunctionInfo> shared_info(
         SharedFunctionInfo::cast(message->shared_info()), isolate);
     SharedFunctionInfo::EnsureSourcePositionsAvailable(isolate, shared_info);
diff --git a/deps/v8/src/objects/js-objects.h b/deps/v8/src/objects/js-objects.h
index e59179cb67..418c12ac50 100644
--- a/deps/v8/src/objects/js-objects.h
+++ b/deps/v8/src/objects/js-objects.h
@@ -515,7 +515,7 @@ class JSObject : public TorqueGeneratedJSObject<JSObject, JSReceiver> {
                                               uint32_t length,
                                               EnsureElementsMode mode);
   static void EnsureCanContainElements(Handle<JSObject> object,
-                                       Arguments* arguments, uint32_t first_arg,
+                                       JavaScriptArguments* arguments,
                                        uint32_t arg_count,
                                        EnsureElementsMode mode);
 
@@ -1443,10 +1443,6 @@ class JSStringIterator
   DECL_PRINTER(JSStringIterator)
   DECL_VERIFIER(JSStringIterator)
 
-  // [index]: The [[StringIteratorNextIndex]] slot.
-  inline int index() const;
-  inline void set_index(int value);
-
   TQ_OBJECT_CONSTRUCTORS(JSStringIterator)
 };
 
diff --git a/deps/v8/src/objects/js-plural-rules-inl.h b/deps/v8/src/objects/js-plural-rules-inl.h
index b8fe7f50f0..40aae56b20 100644
--- a/deps/v8/src/objects/js-plural-rules-inl.h
+++ b/deps/v8/src/objects/js-plural-rules-inl.h
@@ -30,14 +30,14 @@ ACCESSORS(JSPluralRules, icu_number_formatter,
           kIcuNumberFormatterOffset)
 
 inline void JSPluralRules::set_type(Type type) {
-  DCHECK_LE(type, TypeBits::kMax);
+  DCHECK_LE(type, TypeBit::kMax);
   int hints = flags();
-  hints = TypeBits::update(hints, type);
+  hints = TypeBit::update(hints, type);
   set_flags(hints);
 }
 
 inline JSPluralRules::Type JSPluralRules::type() const {
-  return TypeBits::decode(flags());
+  return TypeBit::decode(flags());
 }
 
 CAST_ACCESSOR(JSPluralRules)
diff --git a/deps/v8/src/objects/js-plural-rules.cc b/deps/v8/src/objects/js-plural-rules.cc
index bf928416f4..ffbd53034e 100644
--- a/deps/v8/src/objects/js-plural-rules.cc
+++ b/deps/v8/src/objects/js-plural-rules.cc
@@ -111,9 +111,14 @@ MaybeHandle<JSPluralRules> JSPluralRules::New(Isolate* isolate, Handle<Map> map,
   // 11. Let r be ResolveLocale(%PluralRules%.[[AvailableLocales]],
   // requestedLocales, opt, %PluralRules%.[[RelevantExtensionKeys]],
   // localeData).
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSPluralRules::GetAvailableLocales(),
                           requested_locales, matcher, {});
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSPluralRules);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
   Handle<String> locale_str =
       isolate->factory()->NewStringFromAsciiChecked(r.locale.c_str());
 
@@ -124,7 +129,7 @@ MaybeHandle<JSPluralRules> JSPluralRules::New(Isolate* isolate, Handle<Map> map,
   std::unique_ptr<icu::PluralRules> icu_plural_rules;
   bool success =
       CreateICUPluralRules(isolate, r.icu_locale, type, &icu_plural_rules);
-  if (!success) {
+  if (!success || icu_plural_rules.get() == nullptr) {
     // Remove extensions and try again.
     icu::Locale no_extension_locale(r.icu_locale.getBaseName());
     success = CreateICUPluralRules(isolate, no_extension_locale, type,
@@ -133,13 +138,12 @@ MaybeHandle<JSPluralRules> JSPluralRules::New(Isolate* isolate, Handle<Map> map,
         icu::number::NumberFormatter::withLocale(no_extension_locale)
             .roundingMode(UNUM_ROUND_HALFUP);
 
-    if (!success) {
-      FATAL("Failed to create ICU PluralRules, are ICU data files missing?");
+    if (!success || icu_plural_rules.get() == nullptr) {
+      THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                      JSPluralRules);
     }
   }
 
-  CHECK_NOT_NULL(icu_plural_rules.get());
-
   // 9. Perform ? SetNumberFormatDigitOptions(pluralRules, options, 0, 3).
   Maybe<Intl::NumberFormatDigitOptions> maybe_digit_options =
       Intl::SetNumberFormatDigitOptions(isolate, options, 0, 3, false);
diff --git a/deps/v8/src/objects/js-plural-rules.h b/deps/v8/src/objects/js-plural-rules.h
index 0b2b91ef2b..c5df77b57b 100644
--- a/deps/v8/src/objects/js-plural-rules.h
+++ b/deps/v8/src/objects/js-plural-rules.h
@@ -58,16 +58,13 @@ class JSPluralRules : public JSObject {
   DECL_PRINTER(JSPluralRules)
   DECL_VERIFIER(JSPluralRules)
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) V(TypeBits, Type, 1, _)
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_PLURAL_RULES_FLAGS()
 
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  STATIC_ASSERT(Type::CARDINAL <= TypeBit::kMax);
+  STATIC_ASSERT(Type::ORDINAL <= TypeBit::kMax);
 
-  STATIC_ASSERT(Type::CARDINAL <= TypeBits::kMax);
-  STATIC_ASSERT(Type::ORDINAL <= TypeBits::kMax);
-
-// Layout description.
+  // Layout description.
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
                                 TORQUE_GENERATED_JS_PLURAL_RULES_FIELDS)
 
diff --git a/deps/v8/src/objects/js-promise-inl.h b/deps/v8/src/objects/js-promise-inl.h
index 8b7a11a151..cffd10b9f1 100644
--- a/deps/v8/src/objects/js-promise-inl.h
+++ b/deps/v8/src/objects/js-promise-inl.h
@@ -18,7 +18,6 @@ namespace internal {
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(JSPromise)
 
-TQ_SMI_ACCESSORS(JSPromise, flags)
 BOOL_ACCESSORS(JSPromise, flags, has_handler, kHasHandlerBit)
 BOOL_ACCESSORS(JSPromise, flags, handled_hint, kHandledHintBit)
 
diff --git a/deps/v8/src/objects/js-promise.h b/deps/v8/src/objects/js-promise.h
index 66413bb651..efb13dc015 100644
--- a/deps/v8/src/objects/js-promise.h
+++ b/deps/v8/src/objects/js-promise.h
@@ -32,8 +32,6 @@ class JSPromise : public TorqueGeneratedJSPromise<JSPromise, JSObject> {
   // [reactions]: Checks that the promise is pending and returns the reactions.
   inline Object reactions() const;
 
-  DECL_INT_ACCESSORS(flags)
-
   // [has_handler]: Whether this promise has a reject handler or not.
   DECL_BOOLEAN_ACCESSORS(has_handler)
 
diff --git a/deps/v8/src/objects/js-regexp-string-iterator-inl.h b/deps/v8/src/objects/js-regexp-string-iterator-inl.h
index b204619058..ea44aaae27 100644
--- a/deps/v8/src/objects/js-regexp-string-iterator-inl.h
+++ b/deps/v8/src/objects/js-regexp-string-iterator-inl.h
@@ -17,7 +17,6 @@ namespace internal {
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(JSRegExpStringIterator)
 
-TQ_SMI_ACCESSORS(JSRegExpStringIterator, flags)
 BOOL_ACCESSORS(JSRegExpStringIterator, flags, done, kDoneBit)
 BOOL_ACCESSORS(JSRegExpStringIterator, flags, global, kGlobalBit)
 BOOL_ACCESSORS(JSRegExpStringIterator, flags, unicode, kUnicodeBit)
diff --git a/deps/v8/src/objects/js-regexp-string-iterator.h b/deps/v8/src/objects/js-regexp-string-iterator.h
index ffd38fe211..e54aedbc2b 100644
--- a/deps/v8/src/objects/js-regexp-string-iterator.h
+++ b/deps/v8/src/objects/js-regexp-string-iterator.h
@@ -17,8 +17,6 @@ class JSRegExpStringIterator
     : public TorqueGeneratedJSRegExpStringIterator<JSRegExpStringIterator,
                                                    JSObject> {
  public:
-  DECL_INT_ACCESSORS(flags)
-
   // [boolean]: The [[Done]] internal property.
   DECL_BOOLEAN_ACCESSORS(done)
 
diff --git a/deps/v8/src/objects/js-relative-time-format-inl.h b/deps/v8/src/objects/js-relative-time-format-inl.h
index 1ac0e4733e..74da187246 100644
--- a/deps/v8/src/objects/js-relative-time-format-inl.h
+++ b/deps/v8/src/objects/js-relative-time-format-inl.h
@@ -27,26 +27,15 @@ ACCESSORS(JSRelativeTimeFormat, icu_formatter,
           Managed<icu::RelativeDateTimeFormatter>, kIcuFormatterOffset)
 SMI_ACCESSORS(JSRelativeTimeFormat, flags, kFlagsOffset)
 
-inline void JSRelativeTimeFormat::set_style(Style style) {
-  DCHECK_GE(StyleBits::kMax, style);
-  int hints = flags();
-  hints = StyleBits::update(hints, style);
-  set_flags(hints);
-}
-
-inline JSRelativeTimeFormat::Style JSRelativeTimeFormat::style() const {
-  return StyleBits::decode(flags());
-}
-
 inline void JSRelativeTimeFormat::set_numeric(Numeric numeric) {
-  DCHECK_GE(NumericBits::kMax, numeric);
+  DCHECK_GE(NumericBit::kMax, numeric);
   int hints = flags();
-  hints = NumericBits::update(hints, numeric);
+  hints = NumericBit::update(hints, numeric);
   set_flags(hints);
 }
 
 inline JSRelativeTimeFormat::Numeric JSRelativeTimeFormat::numeric() const {
-  return NumericBits::decode(flags());
+  return NumericBit::decode(flags());
 }
 
 CAST_ACCESSOR(JSRelativeTimeFormat)
diff --git a/deps/v8/src/objects/js-relative-time-format.cc b/deps/v8/src/objects/js-relative-time-format.cc
index 8768560c39..0cb6b117df 100644
--- a/deps/v8/src/objects/js-relative-time-format.cc
+++ b/deps/v8/src/objects/js-relative-time-format.cc
@@ -25,33 +25,42 @@ namespace v8 {
 namespace internal {
 
 namespace {
-UDateRelativeDateTimeFormatterStyle getIcuStyle(
-    JSRelativeTimeFormat::Style style) {
+// Style: identifying the relative time format style used.
+//
+// ecma402/#sec-properties-of-intl-relativetimeformat-instances
+
+enum class Style {
+  LONG,   // Everything spelled out.
+  SHORT,  // Abbreviations used when possible.
+  NARROW  // Use the shortest possible form.
+};
+
+UDateRelativeDateTimeFormatterStyle toIcuStyle(Style style) {
   switch (style) {
-    case JSRelativeTimeFormat::Style::LONG:
+    case Style::LONG:
       return UDAT_STYLE_LONG;
-    case JSRelativeTimeFormat::Style::SHORT:
+    case Style::SHORT:
       return UDAT_STYLE_SHORT;
-    case JSRelativeTimeFormat::Style::NARROW:
+    case Style::NARROW:
       return UDAT_STYLE_NARROW;
   }
   UNREACHABLE();
 }
-}  // namespace
-
-JSRelativeTimeFormat::Style JSRelativeTimeFormat::getStyle(const char* str) {
-  if (strcmp(str, "long") == 0) return JSRelativeTimeFormat::Style::LONG;
-  if (strcmp(str, "short") == 0) return JSRelativeTimeFormat::Style::SHORT;
-  if (strcmp(str, "narrow") == 0) return JSRelativeTimeFormat::Style::NARROW;
-  UNREACHABLE();
-}
 
-JSRelativeTimeFormat::Numeric JSRelativeTimeFormat::getNumeric(
-    const char* str) {
-  if (strcmp(str, "auto") == 0) return JSRelativeTimeFormat::Numeric::AUTO;
-  if (strcmp(str, "always") == 0) return JSRelativeTimeFormat::Numeric::ALWAYS;
+Style fromIcuStyle(UDateRelativeDateTimeFormatterStyle icu_style) {
+  switch (icu_style) {
+    case UDAT_STYLE_LONG:
+      return Style::LONG;
+    case UDAT_STYLE_SHORT:
+      return Style::SHORT;
+    case UDAT_STYLE_NARROW:
+      return Style::NARROW;
+    case UDAT_STYLE_COUNT:
+      UNREACHABLE();
+  }
   UNREACHABLE();
 }
+}  // namespace
 
 MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
     Isolate* isolate, Handle<Map> map, Handle<Object> locales,
@@ -103,9 +112,14 @@ MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
   // ResolveLocale(%RelativeTimeFormat%.[[AvailableLocales]],
   //               requestedLocales, opt,
   //               %RelativeTimeFormat%.[[RelevantExtensionKeys]], localeData).
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSRelativeTimeFormat::GetAvailableLocales(),
                           requested_locales, matcher, {"nu"});
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSRelativeTimeFormat);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
 
   UErrorCode status = U_ZERO_ERROR;
 
@@ -132,10 +146,6 @@ MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
     icu_locale.setUnicodeKeywordValue("nu", numbering_system_str.get(), status);
     CHECK(U_SUCCESS(status));
   }
-  Handle<String> numbering_system_string =
-      isolate->factory()->NewStringFromAsciiChecked(
-          Intl::GetNumberingSystem(icu_locale).c_str());
-
   // 15. Let dataLocale be r.[[DataLocale]].
 
   // 16. Let s be ? GetOption(options, "style", "string",
@@ -164,25 +174,41 @@ MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
   icu::NumberFormat* number_format =
       icu::NumberFormat::createInstance(icu_locale, UNUM_DECIMAL, status);
   if (U_FAILURE(status)) {
-    delete number_format;
-    FATAL("Failed to create ICU number format, are ICU data files missing?");
+    // Data build filter files excluded data in "rbnf_tree" since ECMA402 does
+    // not support "algorithmic" numbering systems. Therefore we may get the
+    // U_MISSING_RESOURCE_ERROR here. Fallback to locale without the numbering
+    // system and create the object again.
+    if (status == U_MISSING_RESOURCE_ERROR) {
+      delete number_format;
+      status = U_ZERO_ERROR;
+      icu_locale.setUnicodeKeywordValue("nu", nullptr, status);
+      CHECK(U_SUCCESS(status));
+      number_format =
+          icu::NumberFormat::createInstance(icu_locale, UNUM_DECIMAL, status);
+    }
+    if (U_FAILURE(status) || number_format == nullptr) {
+      delete number_format;
+      THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                      JSRelativeTimeFormat);
+    }
   }
-  CHECK_NOT_NULL(number_format);
 
   // Change UDISPCTX_CAPITALIZATION_NONE to other values if
   // ECMA402 later include option to change capitalization.
   // Ref: https://github.com/tc39/proposal-intl-relative-time/issues/11
   icu::RelativeDateTimeFormatter* icu_formatter =
       new icu::RelativeDateTimeFormatter(icu_locale, number_format,
-                                         getIcuStyle(style_enum),
+                                         toIcuStyle(style_enum),
                                          UDISPCTX_CAPITALIZATION_NONE, status);
-  if (U_FAILURE(status)) {
+  if (U_FAILURE(status) || icu_formatter == nullptr) {
     delete icu_formatter;
-    FATAL(
-        "Failed to create ICU relative date time formatter, are ICU data files "
-        "missing?");
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSRelativeTimeFormat);
   }
-  CHECK_NOT_NULL(icu_formatter);
+
+  Handle<String> numbering_system_string =
+      isolate->factory()->NewStringFromAsciiChecked(
+          Intl::GetNumberingSystem(icu_locale).c_str());
 
   Handle<Managed<icu::RelativeDateTimeFormatter>> managed_formatter =
       Managed<icu::RelativeDateTimeFormatter>::FromRawPtr(isolate, 0,
@@ -191,11 +217,11 @@ MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
   Handle<JSRelativeTimeFormat> relative_time_format_holder =
       Handle<JSRelativeTimeFormat>::cast(
           isolate->factory()->NewFastOrSlowJSObjectFromMap(map));
+
   DisallowHeapAllocation no_gc;
   relative_time_format_holder->set_flags(0);
   relative_time_format_holder->set_locale(*locale_str);
   relative_time_format_holder->set_numberingSystem(*numbering_system_string);
-  relative_time_format_holder->set_style(style_enum);
   relative_time_format_holder->set_numeric(numeric_enum);
   relative_time_format_holder->set_icu_formatter(*managed_formatter);
 
@@ -203,16 +229,36 @@ MaybeHandle<JSRelativeTimeFormat> JSRelativeTimeFormat::New(
   return relative_time_format_holder;
 }
 
+namespace {
+
+Handle<String> StyleAsString(Isolate* isolate, Style style) {
+  switch (style) {
+    case Style::LONG:
+      return ReadOnlyRoots(isolate).long_string_handle();
+    case Style::SHORT:
+      return ReadOnlyRoots(isolate).short_string_handle();
+    case Style::NARROW:
+      return ReadOnlyRoots(isolate).narrow_string_handle();
+  }
+  UNREACHABLE();
+}
+
+}  // namespace
+
 Handle<JSObject> JSRelativeTimeFormat::ResolvedOptions(
     Isolate* isolate, Handle<JSRelativeTimeFormat> format_holder) {
   Factory* factory = isolate->factory();
+  icu::RelativeDateTimeFormatter* formatter =
+      format_holder->icu_formatter().raw();
+  CHECK_NOT_NULL(formatter);
   Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
   Handle<String> locale(format_holder->locale(), isolate);
   Handle<String> numberingSystem(format_holder->numberingSystem(), isolate);
   JSObject::AddProperty(isolate, result, factory->locale_string(), locale,
                         NONE);
-  JSObject::AddProperty(isolate, result, factory->style_string(),
-                        format_holder->StyleAsString(), NONE);
+  JSObject::AddProperty(
+      isolate, result, factory->style_string(),
+      StyleAsString(isolate, fromIcuStyle(formatter->getFormatStyle())), NONE);
   JSObject::AddProperty(isolate, result, factory->numeric_string(),
                         format_holder->NumericAsString(), NONE);
   JSObject::AddProperty(isolate, result, factory->numberingSystem_string(),
@@ -220,18 +266,6 @@ Handle<JSObject> JSRelativeTimeFormat::ResolvedOptions(
   return result;
 }
 
-Handle<String> JSRelativeTimeFormat::StyleAsString() const {
-  switch (style()) {
-    case Style::LONG:
-      return GetReadOnlyRoots().long_string_handle();
-    case Style::SHORT:
-      return GetReadOnlyRoots().short_string_handle();
-    case Style::NARROW:
-      return GetReadOnlyRoots().narrow_string_handle();
-  }
-  UNREACHABLE();
-}
-
 Handle<String> JSRelativeTimeFormat::NumericAsString() const {
   switch (numeric()) {
     case Numeric::ALWAYS:
diff --git a/deps/v8/src/objects/js-relative-time-format.h b/deps/v8/src/objects/js-relative-time-format.h
index 99d09e5c3c..87aac9f060 100644
--- a/deps/v8/src/objects/js-relative-time-format.h
+++ b/deps/v8/src/objects/js-relative-time-format.h
@@ -40,7 +40,6 @@ class JSRelativeTimeFormat : public JSObject {
   V8_WARN_UNUSED_RESULT static Handle<JSObject> ResolvedOptions(
       Isolate* isolate, Handle<JSRelativeTimeFormat> format_holder);
 
-  Handle<String> StyleAsString() const;
   Handle<String> NumericAsString() const;
 
   // ecma402/#sec-Intl.RelativeTimeFormat.prototype.format
@@ -63,18 +62,6 @@ class JSRelativeTimeFormat : public JSObject {
 
   DECL_ACCESSORS(icu_formatter, Managed<icu::RelativeDateTimeFormatter>)
 
-  // Style: identifying the relative time format style used.
-  //
-  // ecma402/#sec-properties-of-intl-relativetimeformat-instances
-
-  enum class Style {
-    LONG,   // Everything spelled out.
-    SHORT,  // Abbreviations used when possible.
-    NARROW  // Use the shortest possible form.
-  };
-  inline void set_style(Style style);
-  inline Style style() const;
-
   // Numeric: identifying whether numerical descriptions are always used, or
   // used only when no more specific version is available (e.g., "1 day ago" vs
   // "yesterday").
@@ -88,18 +75,11 @@ class JSRelativeTimeFormat : public JSObject {
   inline void set_numeric(Numeric numeric);
   inline Numeric numeric() const;
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) \
-  V(StyleBits, Style, 2, _)    \
-  V(NumericBits, Numeric, 1, _)
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_RELATIVE_TIME_FORMAT_FLAGS()
 
-  STATIC_ASSERT(Style::LONG <= StyleBits::kMax);
-  STATIC_ASSERT(Style::SHORT <= StyleBits::kMax);
-  STATIC_ASSERT(Style::NARROW <= StyleBits::kMax);
-  STATIC_ASSERT(Numeric::AUTO <= NumericBits::kMax);
-  STATIC_ASSERT(Numeric::ALWAYS <= NumericBits::kMax);
+  STATIC_ASSERT(Numeric::AUTO <= NumericBit::kMax);
+  STATIC_ASSERT(Numeric::ALWAYS <= NumericBit::kMax);
 
   // [flags] Bit field containing various flags about the function.
   DECL_INT_ACCESSORS(flags)
@@ -112,9 +92,6 @@ class JSRelativeTimeFormat : public JSObject {
                                 TORQUE_GENERATED_JS_RELATIVE_TIME_FORMAT_FIELDS)
 
  private:
-  static Style getStyle(const char* str);
-  static Numeric getNumeric(const char* str);
-
   OBJECT_CONSTRUCTORS(JSRelativeTimeFormat, JSObject);
 };
 
diff --git a/deps/v8/src/objects/js-segment-iterator-inl.h b/deps/v8/src/objects/js-segment-iterator-inl.h
index b2d745179a..f312f7c91a 100644
--- a/deps/v8/src/objects/js-segment-iterator-inl.h
+++ b/deps/v8/src/objects/js-segment-iterator-inl.h
@@ -27,7 +27,7 @@ ACCESSORS(JSSegmentIterator, unicode_string, Managed<icu::UnicodeString>,
           kUnicodeStringOffset)
 
 BIT_FIELD_ACCESSORS(JSSegmentIterator, flags, is_break_type_set,
-                    JSSegmentIterator::BreakTypeSetBits)
+                    JSSegmentIterator::BreakTypeSetBit)
 
 SMI_ACCESSORS(JSSegmentIterator, flags, kFlagsOffset)
 
diff --git a/deps/v8/src/objects/js-segment-iterator.h b/deps/v8/src/objects/js-segment-iterator.h
index 01fc268298..81ebc4dbd2 100644
--- a/deps/v8/src/objects/js-segment-iterator.h
+++ b/deps/v8/src/objects/js-segment-iterator.h
@@ -76,12 +76,8 @@ class JSSegmentIterator : public JSObject {
   inline void set_granularity(JSSegmenter::Granularity granularity);
   inline JSSegmenter::Granularity granularity() const;
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _)                       \
-  V(GranularityBits, JSSegmenter::Granularity, 2, _) \
-  V(BreakTypeSetBits, bool, 1, _)
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_SEGMENT_ITERATOR_FLAGS()
 
   STATIC_ASSERT(JSSegmenter::Granularity::GRAPHEME <= GranularityBits::kMax);
   STATIC_ASSERT(JSSegmenter::Granularity::WORD <= GranularityBits::kMax);
diff --git a/deps/v8/src/objects/js-segmenter.cc b/deps/v8/src/objects/js-segmenter.cc
index 7985cf1c99..39cf15f628 100644
--- a/deps/v8/src/objects/js-segmenter.cc
+++ b/deps/v8/src/objects/js-segmenter.cc
@@ -23,13 +23,6 @@
 namespace v8 {
 namespace internal {
 
-JSSegmenter::Granularity JSSegmenter::GetGranularity(const char* str) {
-  if (strcmp(str, "grapheme") == 0) return JSSegmenter::Granularity::GRAPHEME;
-  if (strcmp(str, "word") == 0) return JSSegmenter::Granularity::WORD;
-  if (strcmp(str, "sentence") == 0) return JSSegmenter::Granularity::SENTENCE;
-  UNREACHABLE();
-}
-
 MaybeHandle<JSSegmenter> JSSegmenter::New(Isolate* isolate, Handle<Map> map,
                                           Handle<Object> locales,
                                           Handle<Object> input_options) {
@@ -64,9 +57,15 @@ MaybeHandle<JSSegmenter> JSSegmenter::New(Isolate* isolate, Handle<Map> map,
 
   // 9. Let r be ResolveLocale(%Segmenter%.[[AvailableLocales]],
   // requestedLocales, opt, %Segmenter%.[[RelevantExtensionKeys]]).
-  Intl::ResolvedLocale r =
+  Maybe<Intl::ResolvedLocale> maybe_resolve_locale =
       Intl::ResolveLocale(isolate, JSSegmenter::GetAvailableLocales(),
                           requested_locales, matcher, {});
+  if (maybe_resolve_locale.IsNothing()) {
+    THROW_NEW_ERROR(isolate, NewRangeError(MessageTemplate::kIcuError),
+                    JSSegmenter);
+  }
+  Intl::ResolvedLocale r = maybe_resolve_locale.FromJust();
+
   Handle<String> locale_str =
       isolate->factory()->NewStringFromAsciiChecked(r.locale.c_str());
 
diff --git a/deps/v8/src/objects/js-segmenter.h b/deps/v8/src/objects/js-segmenter.h
index b683e95bf1..b2cd1cac1b 100644
--- a/deps/v8/src/objects/js-segmenter.h
+++ b/deps/v8/src/objects/js-segmenter.h
@@ -62,10 +62,8 @@ class JSSegmenter : public JSObject {
   inline void set_granularity(Granularity granularity);
   inline Granularity granularity() const;
 
-// Bit positions in |flags|.
-#define FLAGS_BIT_FIELDS(V, _) V(GranularityBits, Granularity, 2, _)
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  // Bit positions in |flags|.
+  DEFINE_TORQUE_GENERATED_JS_SEGMENTER_FLAGS()
 
   STATIC_ASSERT(Granularity::GRAPHEME <= GranularityBits::kMax);
   STATIC_ASSERT(Granularity::WORD <= GranularityBits::kMax);
@@ -82,8 +80,6 @@ class JSSegmenter : public JSObject {
                                 TORQUE_GENERATED_JS_SEGMENTER_FIELDS)
 
  private:
-  static Granularity GetGranularity(const char* str);
-
   OBJECT_CONSTRUCTORS(JSSegmenter, JSObject);
 };
 
diff --git a/deps/v8/src/objects/js-weak-refs-inl.h b/deps/v8/src/objects/js-weak-refs-inl.h
index 477b88cdd1..939964b47e 100644
--- a/deps/v8/src/objects/js-weak-refs-inl.h
+++ b/deps/v8/src/objects/js-weak-refs-inl.h
@@ -19,25 +19,26 @@ namespace internal {
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(WeakCell)
 TQ_OBJECT_CONSTRUCTORS_IMPL(JSWeakRef)
-OBJECT_CONSTRUCTORS_IMPL(JSFinalizationGroup, JSObject)
-TQ_OBJECT_CONSTRUCTORS_IMPL(JSFinalizationGroupCleanupIterator)
+OBJECT_CONSTRUCTORS_IMPL(JSFinalizationRegistry, JSObject)
+TQ_OBJECT_CONSTRUCTORS_IMPL(JSFinalizationRegistryCleanupIterator)
 
-ACCESSORS(JSFinalizationGroup, native_context, NativeContext,
+ACCESSORS(JSFinalizationRegistry, native_context, NativeContext,
           kNativeContextOffset)
-ACCESSORS(JSFinalizationGroup, cleanup, Object, kCleanupOffset)
-ACCESSORS(JSFinalizationGroup, active_cells, HeapObject, kActiveCellsOffset)
-ACCESSORS(JSFinalizationGroup, cleared_cells, HeapObject, kClearedCellsOffset)
-ACCESSORS(JSFinalizationGroup, key_map, Object, kKeyMapOffset)
-SMI_ACCESSORS(JSFinalizationGroup, flags, kFlagsOffset)
-ACCESSORS(JSFinalizationGroup, next, Object, kNextOffset)
-CAST_ACCESSOR(JSFinalizationGroup)
-
-void JSFinalizationGroup::Register(
-    Handle<JSFinalizationGroup> finalization_group, Handle<JSReceiver> target,
-    Handle<Object> holdings, Handle<Object> unregister_token,
-    Isolate* isolate) {
+ACCESSORS(JSFinalizationRegistry, cleanup, Object, kCleanupOffset)
+ACCESSORS(JSFinalizationRegistry, active_cells, HeapObject, kActiveCellsOffset)
+ACCESSORS(JSFinalizationRegistry, cleared_cells, HeapObject,
+          kClearedCellsOffset)
+ACCESSORS(JSFinalizationRegistry, key_map, Object, kKeyMapOffset)
+SMI_ACCESSORS(JSFinalizationRegistry, flags, kFlagsOffset)
+ACCESSORS(JSFinalizationRegistry, next_dirty, Object, kNextDirtyOffset)
+CAST_ACCESSOR(JSFinalizationRegistry)
+
+void JSFinalizationRegistry::Register(
+    Handle<JSFinalizationRegistry> finalization_registry,
+    Handle<JSReceiver> target, Handle<Object> holdings,
+    Handle<Object> unregister_token, Isolate* isolate) {
   Handle<WeakCell> weak_cell = isolate->factory()->NewWeakCell();
-  weak_cell->set_finalization_group(*finalization_group);
+  weak_cell->set_finalization_registry(*finalization_registry);
   weak_cell->set_target(*target);
   weak_cell->set_holdings(*holdings);
   weak_cell->set_prev(ReadOnlyRoots(isolate).undefined_value());
@@ -47,19 +48,20 @@ void JSFinalizationGroup::Register(
   weak_cell->set_key_list_next(ReadOnlyRoots(isolate).undefined_value());
 
   // Add to active_cells.
-  weak_cell->set_next(finalization_group->active_cells());
-  if (finalization_group->active_cells().IsWeakCell()) {
-    WeakCell::cast(finalization_group->active_cells()).set_prev(*weak_cell);
+  weak_cell->set_next(finalization_registry->active_cells());
+  if (finalization_registry->active_cells().IsWeakCell()) {
+    WeakCell::cast(finalization_registry->active_cells()).set_prev(*weak_cell);
   }
-  finalization_group->set_active_cells(*weak_cell);
+  finalization_registry->set_active_cells(*weak_cell);
 
   if (!unregister_token->IsUndefined(isolate)) {
     Handle<SimpleNumberDictionary> key_map;
-    if (finalization_group->key_map().IsUndefined(isolate)) {
+    if (finalization_registry->key_map().IsUndefined(isolate)) {
       key_map = SimpleNumberDictionary::New(isolate, 1);
     } else {
-      key_map = handle(
-          SimpleNumberDictionary::cast(finalization_group->key_map()), isolate);
+      key_map =
+          handle(SimpleNumberDictionary::cast(finalization_registry->key_map()),
+                 isolate);
     }
 
     // Unregister tokens are held weakly as objects are often their own
@@ -74,29 +76,29 @@ void JSFinalizationGroup::Register(
       weak_cell->set_key_list_next(existing_weak_cell);
     }
     key_map = SimpleNumberDictionary::Set(isolate, key_map, key, weak_cell);
-    finalization_group->set_key_map(*key_map);
+    finalization_registry->set_key_map(*key_map);
   }
 }
 
-bool JSFinalizationGroup::Unregister(
-    Handle<JSFinalizationGroup> finalization_group,
+bool JSFinalizationRegistry::Unregister(
+    Handle<JSFinalizationRegistry> finalization_registry,
     Handle<JSReceiver> unregister_token, Isolate* isolate) {
   // Iterate through the doubly linked list of WeakCells associated with the
   // key. Each WeakCell will be in the "active_cells" or "cleared_cells" list of
-  // its FinalizationGroup; remove it from there.
-  return finalization_group->RemoveUnregisterToken(
+  // its FinalizationRegistry; remove it from there.
+  return finalization_registry->RemoveUnregisterToken(
       *unregister_token, isolate,
       [isolate](WeakCell matched_cell) {
-        matched_cell.RemoveFromFinalizationGroupCells(isolate);
+        matched_cell.RemoveFromFinalizationRegistryCells(isolate);
       },
       [](HeapObject, ObjectSlot, Object) {});
 }
 
 template <typename MatchCallback, typename GCNotifyUpdatedSlotCallback>
-bool JSFinalizationGroup::RemoveUnregisterToken(
+bool JSFinalizationRegistry::RemoveUnregisterToken(
     JSReceiver unregister_token, Isolate* isolate, MatchCallback match_callback,
     GCNotifyUpdatedSlotCallback gc_notify_updated_slot) {
-  // This method is called from both FinalizationGroup#unregister and for
+  // This method is called from both FinalizationRegistry#unregister and for
   // removing weakly-held dead unregister tokens. The latter is during GC so
   // this function cannot GC.
   DisallowHeapAllocation no_gc;
@@ -159,7 +161,7 @@ bool JSFinalizationGroup::RemoveUnregisterToken(
   }
   if (new_key_list_head.IsUndefined(isolate)) {
     DCHECK(was_present);
-    key_map.ClearEntry(isolate, entry);
+    key_map.ClearEntry(entry);
     key_map.ElementRemoved();
   } else {
     key_map.ValueAtPut(entry, new_key_list_head);
@@ -169,41 +171,42 @@ bool JSFinalizationGroup::RemoveUnregisterToken(
   return was_present;
 }
 
-bool JSFinalizationGroup::NeedsCleanup() const {
+bool JSFinalizationRegistry::NeedsCleanup() const {
   return cleared_cells().IsWeakCell();
 }
 
-bool JSFinalizationGroup::scheduled_for_cleanup() const {
+bool JSFinalizationRegistry::scheduled_for_cleanup() const {
   return ScheduledForCleanupField::decode(flags());
 }
 
-void JSFinalizationGroup::set_scheduled_for_cleanup(
+void JSFinalizationRegistry::set_scheduled_for_cleanup(
     bool scheduled_for_cleanup) {
   set_flags(ScheduledForCleanupField::update(flags(), scheduled_for_cleanup));
 }
 
-Object JSFinalizationGroup::PopClearedCellHoldings(
-    Handle<JSFinalizationGroup> finalization_group, Isolate* isolate) {
+Object JSFinalizationRegistry::PopClearedCellHoldings(
+    Handle<JSFinalizationRegistry> finalization_registry, Isolate* isolate) {
   Handle<WeakCell> weak_cell =
-      handle(WeakCell::cast(finalization_group->cleared_cells()), isolate);
+      handle(WeakCell::cast(finalization_registry->cleared_cells()), isolate);
   DCHECK(weak_cell->prev().IsUndefined(isolate));
-  finalization_group->set_cleared_cells(weak_cell->next());
+  finalization_registry->set_cleared_cells(weak_cell->next());
   weak_cell->set_next(ReadOnlyRoots(isolate).undefined_value());
 
-  if (finalization_group->cleared_cells().IsWeakCell()) {
+  if (finalization_registry->cleared_cells().IsWeakCell()) {
     WeakCell cleared_cells_head =
-        WeakCell::cast(finalization_group->cleared_cells());
+        WeakCell::cast(finalization_registry->cleared_cells());
     DCHECK_EQ(cleared_cells_head.prev(), *weak_cell);
     cleared_cells_head.set_prev(ReadOnlyRoots(isolate).undefined_value());
   } else {
-    DCHECK(finalization_group->cleared_cells().IsUndefined(isolate));
+    DCHECK(finalization_registry->cleared_cells().IsUndefined(isolate));
   }
 
   // Also remove the WeakCell from the key_map (if it's there).
   if (!weak_cell->unregister_token().IsUndefined(isolate)) {
     if (weak_cell->key_list_prev().IsUndefined(isolate)) {
-      Handle<SimpleNumberDictionary> key_map = handle(
-          SimpleNumberDictionary::cast(finalization_group->key_map()), isolate);
+      Handle<SimpleNumberDictionary> key_map =
+          handle(SimpleNumberDictionary::cast(finalization_registry->key_map()),
+                 isolate);
       Handle<Object> unregister_token =
           handle(weak_cell->unregister_token(), isolate);
       uint32_t key = Smi::ToInt(unregister_token->GetHash());
@@ -214,7 +217,7 @@ Object JSFinalizationGroup::PopClearedCellHoldings(
         // from the hash table.
         DCHECK(entry.is_found());
         key_map = SimpleNumberDictionary::DeleteEntry(isolate, key_map, entry);
-        finalization_group->set_key_map(*key_map);
+        finalization_registry->set_key_map(*key_map);
       } else {
         // weak_cell is the list head for its key; we need to change the value
         // of the key in the hash table.
@@ -224,7 +227,7 @@ Object JSFinalizationGroup::PopClearedCellHoldings(
         next->set_key_list_prev(ReadOnlyRoots(isolate).undefined_value());
         weak_cell->set_key_list_next(ReadOnlyRoots(isolate).undefined_value());
         key_map = SimpleNumberDictionary::Set(isolate, key_map, key, next);
-        finalization_group->set_key_map(*key_map);
+        finalization_registry->set_key_map(*key_map);
       }
     } else {
       // weak_cell is somewhere in the middle of its key list.
@@ -244,25 +247,26 @@ template <typename GCNotifyUpdatedSlotCallback>
 void WeakCell::Nullify(Isolate* isolate,
                        GCNotifyUpdatedSlotCallback gc_notify_updated_slot) {
   // Remove from the WeakCell from the "active_cells" list of its
-  // JSFinalizationGroup and insert it into the "cleared_cells" list. This is
+  // JSFinalizationRegistry and insert it into the "cleared_cells" list. This is
   // only called for WeakCells which haven't been unregistered yet, so they will
   // be in the active_cells list. (The caller must guard against calling this
   // for unregistered WeakCells by checking that the target is not undefined.)
   DCHECK(target().IsJSReceiver());
   set_target(ReadOnlyRoots(isolate).undefined_value());
 
-  JSFinalizationGroup fg = JSFinalizationGroup::cast(finalization_group());
+  JSFinalizationRegistry fr =
+      JSFinalizationRegistry::cast(finalization_registry());
   if (prev().IsWeakCell()) {
-    DCHECK_NE(fg.active_cells(), *this);
+    DCHECK_NE(fr.active_cells(), *this);
     WeakCell prev_cell = WeakCell::cast(prev());
     prev_cell.set_next(next());
     gc_notify_updated_slot(prev_cell, prev_cell.RawField(WeakCell::kNextOffset),
                            next());
   } else {
-    DCHECK_EQ(fg.active_cells(), *this);
-    fg.set_active_cells(next());
+    DCHECK_EQ(fr.active_cells(), *this);
+    fr.set_active_cells(next());
     gc_notify_updated_slot(
-        fg, fg.RawField(JSFinalizationGroup::kActiveCellsOffset), next());
+        fr, fr.RawField(JSFinalizationRegistry::kActiveCellsOffset), next());
   }
   if (next().IsWeakCell()) {
     WeakCell next_cell = WeakCell::cast(next());
@@ -272,7 +276,7 @@ void WeakCell::Nullify(Isolate* isolate,
   }
 
   set_prev(ReadOnlyRoots(isolate).undefined_value());
-  Object cleared_head = fg.cleared_cells();
+  Object cleared_head = fr.cleared_cells();
   if (cleared_head.IsWeakCell()) {
     WeakCell cleared_head_cell = WeakCell::cast(cleared_head);
     cleared_head_cell.set_prev(*this);
@@ -280,29 +284,30 @@ void WeakCell::Nullify(Isolate* isolate,
                            cleared_head_cell.RawField(WeakCell::kPrevOffset),
                            *this);
   }
-  set_next(fg.cleared_cells());
+  set_next(fr.cleared_cells());
   gc_notify_updated_slot(*this, RawField(WeakCell::kNextOffset), next());
-  fg.set_cleared_cells(*this);
+  fr.set_cleared_cells(*this);
   gc_notify_updated_slot(
-      fg, fg.RawField(JSFinalizationGroup::kClearedCellsOffset), *this);
+      fr, fr.RawField(JSFinalizationRegistry::kClearedCellsOffset), *this);
 }
 
-void WeakCell::RemoveFromFinalizationGroupCells(Isolate* isolate) {
+void WeakCell::RemoveFromFinalizationRegistryCells(Isolate* isolate) {
   // Remove the WeakCell from the list it's in (either "active_cells" or
-  // "cleared_cells" of its JSFinalizationGroup).
+  // "cleared_cells" of its JSFinalizationRegistry).
 
   // It's important to set_target to undefined here. This guards that we won't
   // call Nullify (which assumes that the WeakCell is in active_cells).
   DCHECK(target().IsUndefined() || target().IsJSReceiver());
   set_target(ReadOnlyRoots(isolate).undefined_value());
 
-  JSFinalizationGroup fg = JSFinalizationGroup::cast(finalization_group());
-  if (fg.active_cells() == *this) {
+  JSFinalizationRegistry fr =
+      JSFinalizationRegistry::cast(finalization_registry());
+  if (fr.active_cells() == *this) {
     DCHECK(prev().IsUndefined(isolate));
-    fg.set_active_cells(next());
-  } else if (fg.cleared_cells() == *this) {
+    fr.set_active_cells(next());
+  } else if (fr.cleared_cells() == *this) {
     DCHECK(!prev().IsWeakCell());
-    fg.set_cleared_cells(next());
+    fr.set_cleared_cells(next());
   } else {
     DCHECK(prev().IsWeakCell());
     WeakCell prev_cell = WeakCell::cast(prev());
diff --git a/deps/v8/src/objects/js-weak-refs.h b/deps/v8/src/objects/js-weak-refs.h
index 0b18240e70..ff5cad7ee3 100644
--- a/deps/v8/src/objects/js-weak-refs.h
+++ b/deps/v8/src/objects/js-weak-refs.h
@@ -6,7 +6,6 @@
 #define V8_OBJECTS_JS_WEAK_REFS_H_
 
 #include "src/objects/js-objects.h"
-#include "src/objects/microtask.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -17,13 +16,13 @@ namespace internal {
 class NativeContext;
 class WeakCell;
 
-// FinalizationGroup object from the JS Weak Refs spec proposal:
+// FinalizationRegistry object from the JS Weak Refs spec proposal:
 // https://github.com/tc39/proposal-weakrefs
-class JSFinalizationGroup : public JSObject {
+class JSFinalizationRegistry : public JSObject {
  public:
-  DECL_PRINTER(JSFinalizationGroup)
-  EXPORT_DECL_VERIFIER(JSFinalizationGroup)
-  DECL_CAST(JSFinalizationGroup)
+  DECL_PRINTER(JSFinalizationRegistry)
+  EXPORT_DECL_VERIFIER(JSFinalizationRegistry)
+  DECL_CAST(JSFinalizationRegistry)
 
   DECL_ACCESSORS(native_context, NativeContext)
   DECL_ACCESSORS(cleanup, Object)
@@ -32,18 +31,19 @@ class JSFinalizationGroup : public JSObject {
   DECL_ACCESSORS(cleared_cells, HeapObject)
   DECL_ACCESSORS(key_map, Object)
 
-  // For storing a list of JSFinalizationGroup objects in NativeContext.
-  DECL_ACCESSORS(next, Object)
+  DECL_ACCESSORS(next_dirty, Object)
 
   DECL_INT_ACCESSORS(flags)
 
-  inline static void Register(Handle<JSFinalizationGroup> finalization_group,
-                              Handle<JSReceiver> target,
-                              Handle<Object> holdings, Handle<Object> key,
-                              Isolate* isolate);
-  inline static bool Unregister(Handle<JSFinalizationGroup> finalization_group,
-                                Handle<JSReceiver> unregister_token,
-                                Isolate* isolate);
+  class BodyDescriptor;
+
+  inline static void Register(
+      Handle<JSFinalizationRegistry> finalization_registry,
+      Handle<JSReceiver> target, Handle<Object> holdings, Handle<Object> key,
+      Isolate* isolate);
+  inline static bool Unregister(
+      Handle<JSFinalizationRegistry> finalization_registry,
+      Handle<JSReceiver> unregister_token, Isolate* isolate);
 
   // RemoveUnregisterToken is called from both Unregister and during GC. Since
   // it modifies slots in key_map and WeakCells and the normal write barrier is
@@ -64,27 +64,27 @@ class JSFinalizationGroup : public JSObject {
   // Remove the first cleared WeakCell from the cleared_cells
   // list (assumes there is one) and return its holdings.
   inline static Object PopClearedCellHoldings(
-      Handle<JSFinalizationGroup> finalization_group, Isolate* isolate);
+      Handle<JSFinalizationRegistry> finalization_registry, Isolate* isolate);
 
   // Constructs an iterator for the WeakCells in the cleared_cells list and
   // calls the user's cleanup function.
   //
   // Returns Nothing<bool> if exception occurs, otherwise returns Just(true).
   static V8_WARN_UNUSED_RESULT Maybe<bool> Cleanup(
-      Isolate* isolate, Handle<JSFinalizationGroup> finalization_group,
+      Isolate* isolate, Handle<JSFinalizationRegistry> finalization_registry,
       Handle<Object> callback);
 
   // Layout description.
-  DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
-                                TORQUE_GENERATED_JS_FINALIZATION_GROUP_FIELDS)
+  DEFINE_FIELD_OFFSET_CONSTANTS(
+      JSObject::kHeaderSize, TORQUE_GENERATED_JS_FINALIZATION_REGISTRY_FIELDS)
 
   // Bitfields in flags.
   using ScheduledForCleanupField = base::BitField<bool, 0, 1>;
 
-  OBJECT_CONSTRUCTORS(JSFinalizationGroup, JSObject);
+  OBJECT_CONSTRUCTORS(JSFinalizationRegistry, JSObject);
 };
 
-// Internal object for storing weak references in JSFinalizationGroup.
+// Internal object for storing weak references in JSFinalizationRegistry.
 class WeakCell : public TorqueGeneratedWeakCell<WeakCell, HeapObject> {
  public:
   DECL_PRINTER(WeakCell)
@@ -93,14 +93,14 @@ class WeakCell : public TorqueGeneratedWeakCell<WeakCell, HeapObject> {
   class BodyDescriptor;
 
   // Nullify is called during GC and it modifies the pointers in WeakCell and
-  // JSFinalizationGroup. Thus we need to tell the GC about the modified slots
-  // via the gc_notify_updated_slot function. The normal write barrier is not
-  // enough, since it's disabled before GC.
+  // JSFinalizationRegistry. Thus we need to tell the GC about the modified
+  // slots via the gc_notify_updated_slot function. The normal write barrier is
+  // not enough, since it's disabled before GC.
   template <typename GCNotifyUpdatedSlotCallback>
   inline void Nullify(Isolate* isolate,
                       GCNotifyUpdatedSlotCallback gc_notify_updated_slot);
 
-  inline void RemoveFromFinalizationGroupCells(Isolate* isolate);
+  inline void RemoveFromFinalizationRegistryCells(Isolate* isolate);
 
   TQ_OBJECT_CONSTRUCTORS(WeakCell)
 };
@@ -115,14 +115,14 @@ class JSWeakRef : public TorqueGeneratedJSWeakRef<JSWeakRef, JSObject> {
   TQ_OBJECT_CONSTRUCTORS(JSWeakRef)
 };
 
-class JSFinalizationGroupCleanupIterator
-    : public TorqueGeneratedJSFinalizationGroupCleanupIterator<
-          JSFinalizationGroupCleanupIterator, JSObject> {
+class JSFinalizationRegistryCleanupIterator
+    : public TorqueGeneratedJSFinalizationRegistryCleanupIterator<
+          JSFinalizationRegistryCleanupIterator, JSObject> {
  public:
-  DECL_PRINTER(JSFinalizationGroupCleanupIterator)
-  DECL_VERIFIER(JSFinalizationGroupCleanupIterator)
+  DECL_PRINTER(JSFinalizationRegistryCleanupIterator)
+  DECL_VERIFIER(JSFinalizationRegistryCleanupIterator)
 
-  TQ_OBJECT_CONSTRUCTORS(JSFinalizationGroupCleanupIterator)
+  TQ_OBJECT_CONSTRUCTORS(JSFinalizationRegistryCleanupIterator)
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/js-weak-refs.tq b/deps/v8/src/objects/js-weak-refs.tq
index 879ee6024f..7adcb93d70 100644
--- a/deps/v8/src/objects/js-weak-refs.tq
+++ b/deps/v8/src/objects/js-weak-refs.tq
@@ -2,37 +2,39 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-extern class JSFinalizationGroup extends JSObject {
+extern class JSFinalizationRegistry extends JSObject {
   native_context: NativeContext;
   cleanup: Object;
   active_cells: Undefined|WeakCell;
   cleared_cells: Undefined|WeakCell;
   key_map: Object;
-  next: Undefined|JSFinalizationGroup;
+  // For the linked list of FinalizationRegistries that need cleanup. This
+  // link is weak.
+  next_dirty: Undefined|JSFinalizationRegistry;
   flags: Smi;
 }
 
 @generateCppClass
-extern class JSFinalizationGroupCleanupIterator extends JSObject {
-  finalization_group: JSFinalizationGroup;
+extern class JSFinalizationRegistryCleanupIterator extends JSObject {
+  finalization_registry: JSFinalizationRegistry;
 }
 
 @generateCppClass
 extern class WeakCell extends HeapObject {
-  finalization_group: Undefined|JSFinalizationGroup;
+  finalization_registry: Undefined|JSFinalizationRegistry;
   target: Undefined|JSReceiver;
   unregister_token: Object;
   holdings: Object;
 
-  // For storing doubly linked lists of WeakCells in JSFinalizationGroup's
+  // For storing doubly linked lists of WeakCells in JSFinalizationRegistry's
   // "active_cells" and "cleared_cells" lists.
   prev: Undefined|WeakCell;
   next: Undefined|WeakCell;
 
   // For storing doubly linked lists of WeakCells per key in
-  // JSFinalizationGroup's key-based hashmap. The key is the identity hash of
-  // unregister_token. WeakCell also needs to know its token, so that we can
-  // remove its corresponding key from the key_map when we remove the last
+  // JSFinalizationRegistry's key-based hashmap. The key is the identity hash
+  // of unregister_token. WeakCell also needs to know its token, so that we
+  // can remove its corresponding key from the key_map when we remove the last
   // WeakCell associated with it or when the unregister_token dies. The
   // unregister token is stored above, after target, as both are weak.
   key_list_prev: Undefined|WeakCell;
diff --git a/deps/v8/src/objects/keys.cc b/deps/v8/src/objects/keys.cc
index 99258e695c..16008e39d8 100644
--- a/deps/v8/src/objects/keys.cc
+++ b/deps/v8/src/objects/keys.cc
@@ -57,13 +57,14 @@ static int AddKey(Object key, Handle<FixedArray> combined_keys,
 static Handle<FixedArray> CombineKeys(Isolate* isolate,
                                       Handle<FixedArray> own_keys,
                                       Handle<FixedArray> prototype_chain_keys,
-                                      Handle<JSReceiver> receiver) {
+                                      Handle<JSReceiver> receiver,
+                                      bool may_have_elements) {
   int prototype_chain_keys_length = prototype_chain_keys->length();
   if (prototype_chain_keys_length == 0) return own_keys;
 
   Map map = receiver->map();
   int nof_descriptors = map.NumberOfOwnDescriptors();
-  if (nof_descriptors == 0) return prototype_chain_keys;
+  if (nof_descriptors == 0 && !may_have_elements) return prototype_chain_keys;
 
   Handle<DescriptorArray> descs(map.instance_descriptors(), isolate);
   int own_keys_length = own_keys.is_null() ? 0 : own_keys->length();
@@ -323,13 +324,18 @@ void FastKeyAccumulator::Prepare() {
   // Fully walk the prototype chain and find the last prototype with keys.
   is_receiver_simple_enum_ = false;
   has_empty_prototype_ = true;
+  only_own_has_simple_elements_ =
+      !receiver_->map().IsCustomElementsReceiverMap();
   JSReceiver last_prototype;
   may_have_elements_ = MayHaveElements(*receiver_);
   for (PrototypeIterator iter(isolate_, *receiver_); !iter.IsAtEnd();
        iter.Advance()) {
     JSReceiver current = iter.GetCurrent<JSReceiver>();
-    if (!may_have_elements_) {
-      may_have_elements_ = MayHaveElements(current);
+    if (!may_have_elements_ || only_own_has_simple_elements_) {
+      if (MayHaveElements(current)) {
+        may_have_elements_ = true;
+        only_own_has_simple_elements_ = false;
+      }
     }
     bool has_no_properties = CheckAndInitalizeEmptyEnumCache(current);
     if (has_no_properties) continue;
@@ -564,8 +570,23 @@ MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysSlow(
 
 MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysWithPrototypeInfoCache(
     GetKeysConversion keys_conversion) {
-  Handle<FixedArray> own_keys = KeyAccumulator::GetOwnEnumPropertyKeys(
-      isolate_, Handle<JSObject>::cast(receiver_));
+  Handle<FixedArray> own_keys;
+  if (may_have_elements_) {
+    MaybeHandle<FixedArray> maybe_own_keys;
+    if (receiver_->map().is_dictionary_map()) {
+      maybe_own_keys = GetOwnKeysWithElements<false>(
+          isolate_, Handle<JSObject>::cast(receiver_), keys_conversion,
+          skip_indices_);
+    } else {
+      maybe_own_keys = GetOwnKeysWithElements<true>(
+          isolate_, Handle<JSObject>::cast(receiver_), keys_conversion,
+          skip_indices_);
+    }
+    ASSIGN_RETURN_ON_EXCEPTION(isolate_, own_keys, maybe_own_keys, FixedArray);
+  } else {
+    own_keys = KeyAccumulator::GetOwnEnumPropertyKeys(
+        isolate_, Handle<JSObject>::cast(receiver_));
+  }
   Handle<FixedArray> prototype_chain_keys;
   if (has_prototype_info_cache_) {
     prototype_chain_keys =
@@ -587,7 +608,7 @@ MaybeHandle<FixedArray> FastKeyAccumulator::GetKeysWithPrototypeInfoCache(
     prototype_chain_keys = accumulator.GetKeys(keys_conversion);
   }
   Handle<FixedArray> result = CombineKeys(
-      isolate_, own_keys, prototype_chain_keys, receiver_);
+      isolate_, own_keys, prototype_chain_keys, receiver_, may_have_elements_);
   if (is_for_in_ && own_keys.is_identical_to(result)) {
     // Don't leak the enumeration cache without the receiver since it might get
     // trimmed otherwise.
@@ -605,7 +626,7 @@ bool FastKeyAccumulator::MayHaveElements(JSReceiver receiver) {
 }
 
 bool FastKeyAccumulator::TryPrototypeInfoCache(Handle<JSReceiver> receiver) {
-  if (may_have_elements_) return false;
+  if (may_have_elements_ && !only_own_has_simple_elements_) return false;
   Handle<JSObject> object = Handle<JSObject>::cast(receiver);
   if (!object->HasFastProperties()) return false;
   if (object->HasNamedInterceptor()) return false;
diff --git a/deps/v8/src/objects/keys.h b/deps/v8/src/objects/keys.h
index fd8b3937c8..d0c27b2a4d 100644
--- a/deps/v8/src/objects/keys.h
+++ b/deps/v8/src/objects/keys.h
@@ -192,6 +192,7 @@ class FastKeyAccumulator {
   bool may_have_elements_ = true;
   bool has_prototype_info_cache_ = false;
   bool try_prototype_info_cache_ = false;
+  bool only_own_has_simple_elements_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator);
 };
diff --git a/deps/v8/src/objects/literal-objects-inl.h b/deps/v8/src/objects/literal-objects-inl.h
index 7f0fb6d335..df04c827fe 100644
--- a/deps/v8/src/objects/literal-objects-inl.h
+++ b/deps/v8/src/objects/literal-objects-inl.h
@@ -128,8 +128,6 @@ ACCESSORS(ClassBoilerplate, instance_computed_properties, FixedArray,
 
 TQ_OBJECT_CONSTRUCTORS_IMPL(ArrayBoilerplateDescription)
 
-TQ_SMI_ACCESSORS(ArrayBoilerplateDescription, flags)
-
 ElementsKind ArrayBoilerplateDescription::elements_kind() const {
   return static_cast<ElementsKind>(flags());
 }
diff --git a/deps/v8/src/objects/literal-objects.cc b/deps/v8/src/objects/literal-objects.cc
index c441f05a52..623fbcbaf1 100644
--- a/deps/v8/src/objects/literal-objects.cc
+++ b/deps/v8/src/objects/literal-objects.cc
@@ -5,9 +5,13 @@
 #include "src/objects/literal-objects.h"
 
 #include "src/ast/ast.h"
+#include "src/base/logging.h"
 #include "src/builtins/accessors.h"
+#include "src/common/globals.h"
 #include "src/execution/isolate.h"
 #include "src/heap/factory.h"
+#include "src/heap/off-thread-factory-inl.h"
+#include "src/objects/dictionary.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/objects-inl.h"
@@ -27,8 +31,9 @@ inline int EncodeComputedEntry(ClassBoilerplate::ValueKind value_kind,
   return flags;
 }
 
+template <typename LocalIsolate>
 void AddToDescriptorArrayTemplate(
-    Isolate* isolate, Handle<DescriptorArray> descriptor_array_template,
+    LocalIsolate* isolate, Handle<DescriptorArray> descriptor_array_template,
     Handle<Name> name, ClassBoilerplate::ValueKind value_kind,
     Handle<Object> value) {
   InternalIndex entry = descriptor_array_template->Search(
@@ -79,17 +84,19 @@ void AddToDescriptorArrayTemplate(
   }
 }
 
+template <typename LocalIsolate>
 Handle<NameDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
-    Isolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
+    LocalIsolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
     Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out = nullptr) {
   return NameDictionary::AddNoUpdateNextEnumerationIndex(
       isolate, dictionary, name, value, details, entry_out);
 }
 
+template <typename LocalIsolate>
 Handle<NumberDictionary> DictionaryAddNoUpdateNextEnumerationIndex(
-    Isolate* isolate, Handle<NumberDictionary> dictionary, uint32_t element,
-    Handle<Object> value, PropertyDetails details,
+    LocalIsolate* isolate, Handle<NumberDictionary> dictionary,
+    uint32_t element, Handle<Object> value, PropertyDetails details,
     InternalIndex* entry_out = nullptr) {
   // NumberDictionary does not maintain the enumeration order, so it's
   // a normal Add().
@@ -120,12 +127,13 @@ inline int GetExistingValueIndex(Object value) {
   return value.IsSmi() ? Smi::ToInt(value) : -1;
 }
 
-template <typename Dictionary, typename Key>
-void AddToDictionaryTemplate(Isolate* isolate, Handle<Dictionary> dictionary,
-                             Key key, int key_index,
+template <typename LocalIsolate, typename Dictionary, typename Key>
+void AddToDictionaryTemplate(LocalIsolate* isolate,
+                             Handle<Dictionary> dictionary, Key key,
+                             int key_index,
                              ClassBoilerplate::ValueKind value_kind,
                              Smi value) {
-  InternalIndex entry = dictionary->FindEntry(isolate, key);
+  InternalIndex entry = dictionary->FindEntry(ReadOnlyRoots(isolate), key);
 
   if (entry.is_not_found()) {
     // Entry not found, add new one.
@@ -183,7 +191,7 @@ void AddToDictionaryTemplate(Isolate* isolate, Handle<Dictionary> dictionary,
           // was not defined yet, so overwrite property to kData.
           PropertyDetails details(kData, DONT_ENUM, PropertyCellType::kNoCell,
                                   enum_order);
-          dictionary->DetailsAtPut(isolate, entry, details);
+          dictionary->DetailsAtPut(entry, details);
           dictionary->ValueAtPut(entry, value);
 
         } else {
@@ -217,7 +225,7 @@ void AddToDictionaryTemplate(Isolate* isolate, Handle<Dictionary> dictionary,
         if (!existing_value.IsSmi() || Smi::ToInt(existing_value) < key_index) {
           PropertyDetails details(kData, DONT_ENUM, PropertyCellType::kNoCell,
                                   enum_order);
-          dictionary->DetailsAtPut(isolate, entry, details);
+          dictionary->DetailsAtPut(entry, details);
           dictionary->ValueAtPut(entry, value);
         }
       }
@@ -241,7 +249,7 @@ void AddToDictionaryTemplate(Isolate* isolate, Handle<Dictionary> dictionary,
         pair->set(component, value);
         PropertyDetails details(kAccessor, DONT_ENUM, PropertyCellType::kNoCell,
                                 enum_order);
-        dictionary->DetailsAtPut(isolate, entry, details);
+        dictionary->DetailsAtPut(entry, details);
         dictionary->ValueAtPut(entry, *pair);
       }
     }
@@ -252,6 +260,7 @@ void AddToDictionaryTemplate(Isolate* isolate, Handle<Dictionary> dictionary,
 
 // Helper class that eases building of a properties, elements and computed
 // properties templates.
+template <typename LocalIsolate>
 class ObjectDescriptor {
  public:
   void IncComputedCount() { ++computed_count_; }
@@ -280,35 +289,38 @@ class ObjectDescriptor {
     return computed_properties_;
   }
 
-  void CreateTemplates(Isolate* isolate) {
-    Factory* factory = isolate->factory();
+  void CreateTemplates(LocalIsolate* isolate) {
+    auto* factory = isolate->factory();
     descriptor_array_template_ = factory->empty_descriptor_array();
-    properties_dictionary_template_ = factory->empty_property_dictionary();
+    properties_dictionary_template_ =
+        Handle<NameDictionary>::cast(factory->empty_property_dictionary());
     if (property_count_ || computed_count_ || property_slack_) {
       if (HasDictionaryProperties()) {
         properties_dictionary_template_ = NameDictionary::New(
-            isolate, property_count_ + computed_count_ + property_slack_);
+            isolate, property_count_ + computed_count_ + property_slack_,
+            AllocationType::kOld);
       } else {
         descriptor_array_template_ = DescriptorArray::Allocate(
-            isolate, 0, property_count_ + property_slack_);
+            isolate, 0, property_count_ + property_slack_,
+            AllocationType::kOld);
       }
     }
     elements_dictionary_template_ =
         element_count_ || computed_count_
-            ? NumberDictionary::New(isolate, element_count_ + computed_count_)
+            ? NumberDictionary::New(isolate, element_count_ + computed_count_,
+                                    AllocationType::kOld)
             : factory->empty_slow_element_dictionary();
 
     computed_properties_ =
         computed_count_
-            ? factory->NewFixedArray(computed_count_ *
-                                     ClassBoilerplate::kFullComputedEntrySize)
+            ? factory->NewFixedArray(computed_count_, AllocationType::kOld)
             : factory->empty_fixed_array();
 
     temp_handle_ = handle(Smi::zero(), isolate);
   }
 
-  void AddConstant(Isolate* isolate, Handle<Name> name, Handle<Object> value,
-                   PropertyAttributes attribs) {
+  void AddConstant(LocalIsolate* isolate, Handle<Name> name,
+                   Handle<Object> value, PropertyAttributes attribs) {
     bool is_accessor = value->IsAccessorInfo();
     DCHECK(!value->IsAccessorPair());
     if (HasDictionaryProperties()) {
@@ -326,7 +338,7 @@ class ObjectDescriptor {
     }
   }
 
-  void AddNamedProperty(Isolate* isolate, Handle<Name> name,
+  void AddNamedProperty(LocalIsolate* isolate, Handle<Name> name,
                         ClassBoilerplate::ValueKind value_kind,
                         int value_index) {
     Smi value = Smi::FromInt(value_index);
@@ -341,7 +353,7 @@ class ObjectDescriptor {
     }
   }
 
-  void AddIndexedProperty(Isolate* isolate, uint32_t element,
+  void AddIndexedProperty(LocalIsolate* isolate, uint32_t element,
                           ClassBoilerplate::ValueKind value_kind,
                           int value_index) {
     Smi value = Smi::FromInt(value_index);
@@ -363,12 +375,11 @@ class ObjectDescriptor {
     next_enumeration_index_ = next_index;
   }
 
-  void Finalize(Isolate* isolate) {
+  void Finalize(LocalIsolate* isolate) {
     if (HasDictionaryProperties()) {
+      DCHECK_EQ(current_computed_index_, computed_properties_->length());
       properties_dictionary_template_->set_next_enumeration_index(
           next_enumeration_index_);
-      computed_properties_ = FixedArray::ShrinkOrEmpty(
-          isolate, computed_properties_, current_computed_index_);
     } else {
       DCHECK(descriptor_array_template_->IsSortedNoDuplicates());
     }
@@ -390,36 +401,56 @@ class ObjectDescriptor {
   Handle<Object> temp_handle_;
 };
 
+template <typename LocalIsolate>
 void ClassBoilerplate::AddToPropertiesTemplate(
-    Isolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
+    LocalIsolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value) {
   AddToDictionaryTemplate(isolate, dictionary, name, key_index, value_kind,
                           value);
 }
+template void ClassBoilerplate::AddToPropertiesTemplate(
+    Isolate* isolate, Handle<NameDictionary> dictionary, Handle<Name> name,
+    int key_index, ClassBoilerplate::ValueKind value_kind, Smi value);
+template void ClassBoilerplate::AddToPropertiesTemplate(
+    OffThreadIsolate* isolate, Handle<NameDictionary> dictionary,
+    Handle<Name> name, int key_index, ClassBoilerplate::ValueKind value_kind,
+    Smi value);
 
+template <typename LocalIsolate>
 void ClassBoilerplate::AddToElementsTemplate(
-    Isolate* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
+    LocalIsolate* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
     int key_index, ClassBoilerplate::ValueKind value_kind, Smi value) {
   AddToDictionaryTemplate(isolate, dictionary, key, key_index, value_kind,
                           value);
 }
+template void ClassBoilerplate::AddToElementsTemplate(
+    Isolate* isolate, Handle<NumberDictionary> dictionary, uint32_t key,
+    int key_index, ClassBoilerplate::ValueKind value_kind, Smi value);
+template void ClassBoilerplate::AddToElementsTemplate(
+    OffThreadIsolate* isolate, Handle<NumberDictionary> dictionary,
+    uint32_t key, int key_index, ClassBoilerplate::ValueKind value_kind,
+    Smi value);
 
+template <typename LocalIsolate>
 Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
-    Isolate* isolate, ClassLiteral* expr) {
+    LocalIsolate* isolate, ClassLiteral* expr) {
   // Create a non-caching handle scope to ensure that the temporary handle used
   // by ObjectDescriptor for passing Smis around does not corrupt handle cache
   // in CanonicalHandleScope.
-  HandleScope scope(isolate);
-  Factory* factory = isolate->factory();
-  ObjectDescriptor static_desc(kMinimumClassPropertiesCount);
-  ObjectDescriptor instance_desc(kMinimumPrototypePropertiesCount);
+  typename LocalIsolate::HandleScopeType scope(isolate);
+  auto* factory = isolate->factory();
+  ObjectDescriptor<LocalIsolate> static_desc(kMinimumClassPropertiesCount);
+  ObjectDescriptor<LocalIsolate> instance_desc(
+      kMinimumPrototypePropertiesCount);
 
   for (int i = 0; i < expr->public_members()->length(); i++) {
     ClassLiteral::Property* property = expr->public_members()->at(i);
-    ObjectDescriptor& desc =
+    ObjectDescriptor<LocalIsolate>& desc =
         property->is_static() ? static_desc : instance_desc;
     if (property->is_computed_name()) {
-      desc.IncComputedCount();
+      if (property->kind() != ClassLiteral::Property::FIELD) {
+        desc.IncComputedCount();
+      }
     } else {
       if (property->key()->AsLiteral()->IsPropertyName()) {
         desc.IncPropertiesCount();
@@ -500,7 +531,7 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
         continue;
     }
 
-    ObjectDescriptor& desc =
+    ObjectDescriptor<LocalIsolate>& desc =
         property->is_static() ? static_desc : instance_desc;
     if (property->is_computed_name()) {
       int computed_name_index = dynamic_argument_index;
@@ -516,8 +547,7 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
       desc.AddIndexedProperty(isolate, index, value_kind, value_index);
 
     } else {
-      Handle<String> name =
-          key_literal->AsRawPropertyName()->string().get<Factory>();
+      Handle<String> name = key_literal->AsRawPropertyName()->string();
       DCHECK(name->IsInternalizedString());
       desc.AddNamedProperty(isolate, name, value_kind, value_index);
     }
@@ -543,8 +573,8 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
   static_desc.Finalize(isolate);
   instance_desc.Finalize(isolate);
 
-  Handle<ClassBoilerplate> class_boilerplate =
-      Handle<ClassBoilerplate>::cast(factory->NewFixedArray(kBoileplateLength));
+  Handle<ClassBoilerplate> class_boilerplate = Handle<ClassBoilerplate>::cast(
+      factory->NewFixedArray(kBoileplateLength, AllocationType::kOld));
 
   class_boilerplate->set_flags(0);
   class_boilerplate->set_install_class_name_accessor(
@@ -568,5 +598,10 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
   return scope.CloseAndEscape(class_boilerplate);
 }
 
+template Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
+    Isolate* isolate, ClassLiteral* expr);
+template Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
+    OffThreadIsolate* isolate, ClassLiteral* expr);
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/objects/literal-objects.h b/deps/v8/src/objects/literal-objects.h
index c3b5c914e9..79ac4d2f6a 100644
--- a/deps/v8/src/objects/literal-objects.h
+++ b/deps/v8/src/objects/literal-objects.h
@@ -70,7 +70,6 @@ class ArrayBoilerplateDescription
   void BriefPrintDetails(std::ostream& os);
 
  private:
-  DECL_INT_ACCESSORS(flags)
   TQ_OBJECT_CONSTRUCTORS(ArrayBoilerplateDescription)
 };
 
@@ -117,17 +116,20 @@ class ClassBoilerplate : public FixedArray {
   DECL_ACCESSORS(instance_elements_template, Object)
   DECL_ACCESSORS(instance_computed_properties, FixedArray)
 
-  static void AddToPropertiesTemplate(Isolate* isolate,
+  template <typename LocalIsolate>
+  static void AddToPropertiesTemplate(LocalIsolate* isolate,
                                       Handle<NameDictionary> dictionary,
                                       Handle<Name> name, int key_index,
                                       ValueKind value_kind, Smi value);
 
-  static void AddToElementsTemplate(Isolate* isolate,
+  template <typename LocalIsolate>
+  static void AddToElementsTemplate(LocalIsolate* isolate,
                                     Handle<NumberDictionary> dictionary,
                                     uint32_t key, int key_index,
                                     ValueKind value_kind, Smi value);
 
-  static Handle<ClassBoilerplate> BuildClassBoilerplate(Isolate* isolate,
+  template <typename LocalIsolate>
+  static Handle<ClassBoilerplate> BuildClassBoilerplate(LocalIsolate* isolate,
                                                         ClassLiteral* expr);
 
   enum {
@@ -141,8 +143,6 @@ class ClassBoilerplate : public FixedArray {
     kBoileplateLength  // last element
   };
 
-  static const int kFullComputedEntrySize = 2;
-
  private:
   DECL_INT_ACCESSORS(flags)
 
diff --git a/deps/v8/src/objects/lookup.cc b/deps/v8/src/objects/lookup.cc
index 5fe8889779..f0f3a21baf 100644
--- a/deps/v8/src/objects/lookup.cc
+++ b/deps/v8/src/objects/lookup.cc
@@ -537,8 +537,7 @@ void LookupIterator::ReconfigureDataProperty(Handle<Object> value,
       int enumeration_index = original_details.dictionary_index();
       DCHECK_GT(enumeration_index, 0);
       details = details.set_index(enumeration_index);
-      dictionary->SetEntry(isolate(), dictionary_entry(), *name(), *value,
-                           details);
+      dictionary->SetEntry(dictionary_entry(), *name(), *value, details);
       property_details_ = details;
     }
     state_ = DATA;
diff --git a/deps/v8/src/objects/map-inl.h b/deps/v8/src/objects/map-inl.h
index ba37b98fbe..4317be20c6 100644
--- a/deps/v8/src/objects/map-inl.h
+++ b/deps/v8/src/objects/map-inl.h
@@ -574,7 +574,7 @@ void Map::NotifyLeafMapLayoutChange(Isolate* isolate) {
   if (is_stable()) {
     mark_unstable();
     dependent_code().DeoptimizeDependentCodeGroup(
-        isolate, DependentCode::kPrototypeCheckGroup);
+        DependentCode::kPrototypeCheckGroup);
   }
 }
 
diff --git a/deps/v8/src/objects/map.cc b/deps/v8/src/objects/map.cc
index d2adfd1060..2dc288628c 100644
--- a/deps/v8/src/objects/map.cc
+++ b/deps/v8/src/objects/map.cc
@@ -21,8 +21,10 @@
 #include "src/objects/oddball.h"
 #include "src/objects/property.h"
 #include "src/objects/transitions-inl.h"
+#include "src/roots/roots.h"
 #include "src/utils/ostreams.h"
 #include "src/zone/zone-containers.h"
+#include "torque-generated/field-offsets-tq.h"
 
 namespace v8 {
 namespace internal {
@@ -73,15 +75,21 @@ void Map::PrintReconfiguration(Isolate* isolate, FILE* file,
   os << "]\n";
 }
 
-Map Map::GetStructMap(Isolate* isolate, InstanceType type) {
+Map Map::GetInstanceTypeMap(ReadOnlyRoots roots, InstanceType type) {
   Map map;
   switch (type) {
-#define MAKE_CASE(TYPE, Name, name)            \
-  case TYPE:                                   \
-    map = ReadOnlyRoots(isolate).name##_map(); \
+#define MAKE_CASE(TYPE, Name, name) \
+  case TYPE:                        \
+    map = roots.name##_map();       \
     break;
     STRUCT_LIST(MAKE_CASE)
 #undef MAKE_CASE
+#define MAKE_CASE(_, TYPE, Name, name) \
+  case TYPE:                           \
+    map = roots.name##_map();          \
+    break;
+    TORQUE_INTERNAL_CLASS_LIST_GENERATOR(MAKE_CASE, _)
+#undef MAKE_CASE
     default:
       UNREACHABLE();
   }
@@ -259,6 +267,9 @@ VisitorId Map::GetVisitorId(Map map) {
     case UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE:
       return kVisitUncompiledDataWithPreparseData;
 
+    case COVERAGE_INFO_TYPE:
+      return kVisitCoverageInfo;
+
     case JS_OBJECT_TYPE:
     case JS_ERROR_TYPE:
     case JS_ARGUMENTS_OBJECT_TYPE:
@@ -284,8 +295,8 @@ VisitorId Map::GetVisitorId(Map map) {
     case JS_PROMISE_TYPE:
     case JS_REG_EXP_TYPE:
     case JS_REG_EXP_STRING_ITERATOR_TYPE:
-    case JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE:
-    case JS_FINALIZATION_GROUP_TYPE:
+    case JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE:
+    case JS_FINALIZATION_REGISTRY_TYPE:
 #ifdef V8_INTL_SUPPORT
     case JS_V8_BREAK_ITERATOR_TYPE:
     case JS_COLLATOR_TYPE:
@@ -356,6 +367,12 @@ VisitorId Map::GetVisitorId(Map map) {
     case SYNTHETIC_MODULE_TYPE:
       return kVisitSyntheticModule;
 
+#define MAKE_TQ_CASE(TYPE, Name) \
+  case TYPE:                     \
+    return kVisit##Name;
+      TORQUE_BODY_DESCRIPTOR_LIST(MAKE_TQ_CASE)
+#undef MAKE_TQ_CASE
+
     default:
       UNREACHABLE();
   }
@@ -594,10 +611,10 @@ void Map::DeprecateTransitionTree(Isolate* isolate) {
   DCHECK(!constructor_or_backpointer().IsFunctionTemplateInfo());
   set_is_deprecated(true);
   if (FLAG_trace_maps) {
-    LOG(isolate, MapEvent("Deprecate", *this, Map()));
+    LOG(isolate, MapEvent("Deprecate", handle(*this, isolate), Handle<Map>()));
   }
   dependent_code().DeoptimizeDependentCodeGroup(
-      isolate, DependentCode::kTransitionGroup);
+      DependentCode::kTransitionGroup);
   NotifyLeafMapLayoutChange(isolate);
 }
 
@@ -778,7 +795,7 @@ void Map::GeneralizeField(Isolate* isolate, Handle<Map> map,
   field_owner->UpdateFieldType(isolate, modify_index, name, new_constness,
                                new_representation, wrapped_type);
   field_owner->dependent_code().DeoptimizeDependentCodeGroup(
-      isolate, DependentCode::kFieldOwnerGroup);
+      DependentCode::kFieldOwnerGroup);
 
   if (FLAG_trace_generalization) {
     map->PrintGeneralization(
@@ -1511,7 +1528,7 @@ Handle<Map> Map::Normalize(Isolate* isolate, Handle<Map> fast_map,
     }
   }
   if (FLAG_trace_maps) {
-    LOG(isolate, MapEvent("Normalize", *fast_map, *new_map, reason));
+    LOG(isolate, MapEvent("Normalize", fast_map, new_map, reason));
   }
   fast_map->NotifyLeafMapLayoutChange(isolate);
   return new_map;
@@ -1697,12 +1714,12 @@ void Map::ConnectTransition(Isolate* isolate, Handle<Map> parent,
   if (parent->is_prototype_map()) {
     DCHECK(child->is_prototype_map());
     if (FLAG_trace_maps) {
-      LOG(isolate, MapEvent("Transition", *parent, *child, "prototype", *name));
+      LOG(isolate, MapEvent("Transition", parent, child, "prototype", name));
     }
   } else {
     TransitionsAccessor(isolate, parent).Insert(name, child, flag);
     if (FLAG_trace_maps) {
-      LOG(isolate, MapEvent("Transition", *parent, *child, "", *name));
+      LOG(isolate, MapEvent("Transition", parent, child, "", name));
     }
   }
 }
@@ -1748,8 +1765,8 @@ Handle<Map> Map::CopyReplaceDescriptors(
       (map->is_prototype_map() ||
        !(flag == INSERT_TRANSITION &&
          TransitionsAccessor(isolate, map).CanHaveMoreTransitions()))) {
-    LOG(isolate, MapEvent("ReplaceDescriptors", *map, *result, reason,
-                          maybe_name.is_null() ? Name() : *name));
+    LOG(isolate, MapEvent("ReplaceDescriptors", map, result, reason,
+                          maybe_name.is_null() ? Handle<HeapObject>() : name));
   }
   return result;
 }
@@ -2193,7 +2210,7 @@ Handle<Map> Map::TransitionToDataProperty(Isolate* isolate, Handle<Map> map,
 
       // Deoptimize all code that embeds the previous initial map.
       initial_map->dependent_code().DeoptimizeDependentCodeGroup(
-          isolate, DependentCode::kInitialMapChangedGroup);
+          DependentCode::kInitialMapChangedGroup);
       if (!result->EquivalentToForNormalization(*map,
                                                 CLEAR_INOBJECT_PROPERTIES)) {
         result =
diff --git a/deps/v8/src/objects/map.h b/deps/v8/src/objects/map.h
index 60f1fb6e9c..0b817e3bab 100644
--- a/deps/v8/src/objects/map.h
+++ b/deps/v8/src/objects/map.h
@@ -25,6 +25,7 @@ enum InstanceType : uint16_t;
 #define DATA_ONLY_VISITOR_ID_LIST(V) \
   V(BigInt)                          \
   V(ByteArray)                       \
+  V(CoverageInfo)                    \
   V(DataObject)                      \
   V(FeedbackMetadata)                \
   V(FixedDoubleArray)                \
@@ -83,6 +84,13 @@ enum InstanceType : uint16_t;
   V(WeakArray)                         \
   V(WeakCell)
 
+#define TORQUE_OBJECT_BODY_TO_VISITOR_ID_LIST_ADAPTER(V, TYPE, TypeName) \
+  V(TypeName)
+
+#define TORQUE_VISITOR_ID_LIST(V)        \
+  TORQUE_BODY_DESCRIPTOR_LIST_GENERATOR( \
+      TORQUE_OBJECT_BODY_TO_VISITOR_ID_LIST_ADAPTER, V)
+
 // Objects with the same visitor id are processed in the same way by
 // the heap visitors. The visitor ids for data only objects must precede
 // other visitor ids. We rely on kDataOnlyVisitorIdCount for quick check
@@ -91,8 +99,9 @@ enum VisitorId {
 #define VISITOR_ID_ENUM_DECL(id) kVisit##id,
   DATA_ONLY_VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL) kDataOnlyVisitorIdCount,
   POINTER_VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL)
+      TORQUE_VISITOR_ID_LIST(VISITOR_ID_ENUM_DECL)
 #undef VISITOR_ID_ENUM_DECL
-      kVisitorIdCount
+          kVisitorIdCount
 };
 
 enum class ObjectFields {
@@ -253,7 +262,9 @@ class Map : public HeapObject {
   DECL_PRIMITIVE_ACCESSORS(relaxed_bit_field, byte)
 
   // Bit positions for |bit_field|.
-  using Bits1 = TorqueGeneratedMapBitFields1Fields;
+  struct Bits1 {
+    DEFINE_TORQUE_GENERATED_MAP_BIT_FIELDS1()
+  };
 
   //
   // Bit field 2.
@@ -261,7 +272,9 @@ class Map : public HeapObject {
   DECL_PRIMITIVE_ACCESSORS(bit_field2, byte)
 
   // Bit positions for |bit_field2|.
-  using Bits2 = TorqueGeneratedMapBitFields2Fields;
+  struct Bits2 {
+    DEFINE_TORQUE_GENERATED_MAP_BIT_FIELDS2()
+  };
 
   //
   // Bit field 3.
@@ -273,7 +286,9 @@ class Map : public HeapObject {
   V8_INLINE void clear_padding();
 
   // Bit positions for |bit_field3|.
-  using Bits3 = TorqueGeneratedMapBitFields3Fields;
+  struct Bits3 {
+    DEFINE_TORQUE_GENERATED_MAP_BIT_FIELDS3()
+  };
 
   // Ensure that Torque-defined bit widths for |bit_field3| are as expected.
   STATIC_ASSERT(Bits3::EnumLengthBits::kSize == kDescriptorIndexBitCount);
@@ -787,7 +802,7 @@ class Map : public HeapObject {
 
   inline bool CanTransition() const;
 
-  static Map GetStructMap(Isolate* isolate, InstanceType type);
+  static Map GetInstanceTypeMap(ReadOnlyRoots roots, InstanceType type);
 
 #define DECL_TESTER(Type, ...) inline bool Is##Type##Map() const;
   INSTANCE_TYPE_CHECKERS(DECL_TESTER)
diff --git a/deps/v8/src/objects/module-inl.h b/deps/v8/src/objects/module-inl.h
index aaf790cc8a..ce03c39500 100644
--- a/deps/v8/src/objects/module-inl.h
+++ b/deps/v8/src/objects/module-inl.h
@@ -36,12 +36,8 @@ ACCESSORS(Module, exception, Object, kExceptionOffset)
 SMI_ACCESSORS(Module, status, kStatusOffset)
 SMI_ACCESSORS(Module, hash, kHashOffset)
 
-TQ_SMI_ACCESSORS(SourceTextModule, dfs_index)
-TQ_SMI_ACCESSORS(SourceTextModule, dfs_ancestor_index)
-TQ_SMI_ACCESSORS(SourceTextModule, flags)
 BOOL_ACCESSORS(SourceTextModule, flags, async, kAsyncBit)
 BOOL_ACCESSORS(SourceTextModule, flags, async_evaluating, kAsyncEvaluatingBit)
-TQ_SMI_ACCESSORS(SourceTextModule, pending_async_dependencies)
 ACCESSORS(SourceTextModule, async_parent_modules, ArrayList,
           kAsyncParentModulesOffset)
 ACCESSORS(SourceTextModule, top_level_capability, HeapObject,
@@ -53,11 +49,6 @@ SourceTextModuleInfo SourceTextModule::info() const {
              : GetSharedFunctionInfo().scope_info().ModuleDescriptorInfo();
 }
 
-TQ_SMI_ACCESSORS(SourceTextModuleInfoEntry, module_request)
-TQ_SMI_ACCESSORS(SourceTextModuleInfoEntry, cell_index)
-TQ_SMI_ACCESSORS(SourceTextModuleInfoEntry, beg_pos)
-TQ_SMI_ACCESSORS(SourceTextModuleInfoEntry, end_pos)
-
 OBJECT_CONSTRUCTORS_IMPL(SourceTextModuleInfo, FixedArray)
 CAST_ACCESSOR(SourceTextModuleInfo)
 
@@ -121,10 +112,13 @@ class UnorderedModuleSet
 };
 
 void SourceTextModule::AddAsyncParentModule(Isolate* isolate,
-                                            Handle<SourceTextModule> module) {
+                                            Handle<SourceTextModule> module,
+                                            Handle<SourceTextModule> parent) {
+  Handle<ArrayList> async_parent_modules(module->async_parent_modules(),
+                                         isolate);
   Handle<ArrayList> new_array_list =
-      ArrayList::Add(isolate, handle(async_parent_modules(), isolate), module);
-  set_async_parent_modules(*new_array_list);
+      ArrayList::Add(isolate, async_parent_modules, parent);
+  module->set_async_parent_modules(*new_array_list);
 }
 
 Handle<SourceTextModule> SourceTextModule::GetAsyncParentModule(
diff --git a/deps/v8/src/objects/name.h b/deps/v8/src/objects/name.h
index 783beb12a5..533d8b000e 100644
--- a/deps/v8/src/objects/name.h
+++ b/deps/v8/src/objects/name.h
@@ -69,14 +69,13 @@ class Name : public TorqueGeneratedName<Name, PrimitiveHeapObject> {
   int NameShortPrint(Vector<char> str);
 
   // Mask constant for checking if a name has a computed hash code
-  // and if it is a string that is an array index.  The least significant bit
+  // and if it is a string that is an integer index.  The least significant bit
   // indicates whether a hash code has been computed.  If the hash code has
   // been computed the 2nd bit tells whether the string can be used as an
-  // array index.
+  // integer index (up to MAX_SAFE_INTEGER).
   static const int kHashNotComputedMask = 1;
-  static const int kIsNotArrayIndexMask = 1 << 1;
-  static const int kIsNotIntegerIndexMask = 1 << 2;
-  static const int kNofHashBitFields = 3;
+  static const int kIsNotIntegerIndexMask = 1 << 1;
+  static const int kNofHashBitFields = 2;
 
   // Shift constant retrieving hash code from hash field.
   static const int kHashShift = kNofHashBitFields;
@@ -126,11 +125,11 @@ class Name : public TorqueGeneratedName<Name, PrimitiveHeapObject> {
   static const unsigned int kDoesNotContainCachedArrayIndexMask =
       (~static_cast<unsigned>(kMaxCachedArrayIndexLength)
        << ArrayIndexLengthBits::kShift) |
-      kIsNotArrayIndexMask;
+      kIsNotIntegerIndexMask;
 
   // Value of empty hash field indicating that the hash is not computed.
   static const int kEmptyHashField =
-      kIsNotIntegerIndexMask | kIsNotArrayIndexMask | kHashNotComputedMask;
+      kIsNotIntegerIndexMask | kHashNotComputedMask;
 
  protected:
   static inline bool IsHashFieldComputed(uint32_t field);
@@ -139,9 +138,10 @@ class Name : public TorqueGeneratedName<Name, PrimitiveHeapObject> {
 };
 
 // ES6 symbols.
-class Symbol : public TorqueGeneratedSymbol<Symbol, Name>,
-               public TorqueGeneratedSymbolFlagsFields {
+class Symbol : public TorqueGeneratedSymbol<Symbol, Name> {
  public:
+  DEFINE_TORQUE_GENERATED_SYMBOL_FLAGS()
+
   // [is_private]: Whether this is a private symbol.  Private symbols can only
   // be used to designate own properties of objects.
   DECL_BOOLEAN_ACCESSORS(is_private)
diff --git a/deps/v8/src/objects/object-list-macros.h b/deps/v8/src/objects/object-list-macros.h
index 2110ad772b..11b5c034c9 100644
--- a/deps/v8/src/objects/object-list-macros.h
+++ b/deps/v8/src/objects/object-list-macros.h
@@ -5,6 +5,10 @@
 #ifndef V8_OBJECTS_OBJECT_LIST_MACROS_H_
 #define V8_OBJECTS_OBJECT_LIST_MACROS_H_
 
+#include "torque-generated/instance-types-tq.h"
+
+#define TORQUE_INTERNAL_CLASS_NAMES_ADAPTER(V, NAME, Name, name) V(Name)
+
 namespace v8 {
 namespace internal {
 
@@ -140,8 +144,8 @@ class ZoneForwardList;
   V(JSDataView)                                \
   V(JSDate)                                    \
   V(JSError)                                   \
-  V(JSFinalizationGroup)                       \
-  V(JSFinalizationGroupCleanupIterator)        \
+  V(JSFinalizationRegistry)                    \
+  V(JSFinalizationRegistryCleanupIterator)     \
   V(JSFunction)                                \
   V(JSFunctionOrBoundFunction)                 \
   V(JSGeneratorObject)                         \
@@ -233,7 +237,8 @@ class ZoneForwardList;
   V(WasmTableObject)                           \
   V(WeakFixedArray)                            \
   V(WeakArrayList)                             \
-  V(WeakCell)
+  V(WeakCell)                                  \
+  TORQUE_INTERNAL_CLASS_LIST_GENERATOR(TORQUE_INTERNAL_CLASS_NAMES_ADAPTER, V)
 
 #ifdef V8_INTL_SUPPORT
 #define HEAP_OBJECT_ORDINARY_TYPE_LIST(V) \
diff --git a/deps/v8/src/objects/object-macros.h b/deps/v8/src/objects/object-macros.h
index 518f59507b..2c913c9bc5 100644
--- a/deps/v8/src/objects/object-macros.h
+++ b/deps/v8/src/objects/object-macros.h
@@ -229,14 +229,6 @@
     TaggedField<Smi, offset>::Relaxed_Store(*this, Smi::FromInt(value)); \
   }
 
-#define TQ_SMI_ACCESSORS(holder, name)                                       \
-  int holder::name() const {                                                 \
-    return TorqueGenerated##holder<holder, Super>::name().value();           \
-  }                                                                          \
-  void holder::set_##name(int value) {                                       \
-    TorqueGenerated##holder<holder, Super>::set_##name(Smi::FromInt(value)); \
-  }
-
 #define BOOL_GETTER(holder, field, name, offset) \
   bool holder::name() const { return BooleanBit::get(field(), offset); }
 
diff --git a/deps/v8/src/objects/objects-body-descriptors-inl.h b/deps/v8/src/objects/objects-body-descriptors-inl.h
index 872acdec22..60c508e336 100644
--- a/deps/v8/src/objects/objects-body-descriptors-inl.h
+++ b/deps/v8/src/objects/objects-body-descriptors-inl.h
@@ -248,6 +248,27 @@ class JSWeakRef::BodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
+class JSFinalizationRegistry::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map map, HeapObject obj, int offset) {
+    return IsValidJSObjectSlotImpl(map, obj, offset);
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map map, HeapObject obj, int object_size,
+                                 ObjectVisitor* v) {
+    IteratePointers(obj, JSObject::BodyDescriptor::kStartOffset,
+                    kNextDirtyOffset, v);
+    IterateCustomWeakPointer(obj, kNextDirtyOffset, v);
+    IterateJSObjectBodyImpl(map, obj, kNextDirtyOffset + kTaggedSize,
+                            object_size, v);
+  }
+
+  static inline int SizeOf(Map map, HeapObject object) {
+    return map.instance_size();
+  }
+};
+
 class SharedFunctionInfo::BodyDescriptor final : public BodyDescriptorBase {
  public:
   static bool IsValidSlot(Map map, HeapObject obj, int offset) {
@@ -402,7 +423,7 @@ class V8_EXPORT_PRIVATE SmallOrderedHashTable<Derived>::BodyDescriptor final
 
   static inline int SizeOf(Map map, HeapObject obj) {
     Derived table = Derived::cast(obj);
-    return table.SizeFor(table.Capacity());
+    return Derived::SizeFor(table.Capacity());
   }
 };
 
@@ -600,6 +621,20 @@ class ExternalTwoByteString::BodyDescriptor final : public BodyDescriptorBase {
   static inline int SizeOf(Map map, HeapObject object) { return kSize; }
 };
 
+class CoverageInfo::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map map, HeapObject obj, int offset) { return false; }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map map, HeapObject obj, int object_size,
+                                 ObjectVisitor* v) {}
+
+  static inline int SizeOf(Map map, HeapObject object) {
+    CoverageInfo info = CoverageInfo::cast(object);
+    return CoverageInfo::SizeFor(info.slot_count());
+  }
+};
+
 class Code::BodyDescriptor final : public BodyDescriptorBase {
  public:
   STATIC_ASSERT(kRelocationInfoOffset + kTaggedSize ==
@@ -656,7 +691,7 @@ class SeqOneByteString::BodyDescriptor final : public BodyDescriptorBase {
 
   static inline int SizeOf(Map map, HeapObject obj) {
     SeqOneByteString string = SeqOneByteString::cast(obj);
-    return string.SizeFor(string.synchronized_length());
+    return SeqOneByteString::SizeFor(string.synchronized_length());
   }
 };
 
@@ -670,7 +705,7 @@ class SeqTwoByteString::BodyDescriptor final : public BodyDescriptorBase {
 
   static inline int SizeOf(Map map, HeapObject obj) {
     SeqTwoByteString string = SeqTwoByteString::cast(obj);
-    return string.SizeFor(string.synchronized_length());
+    return SeqTwoByteString::SizeFor(string.synchronized_length());
   }
 };
 
@@ -912,6 +947,8 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
       return Op::template apply<FeedbackCell::BodyDescriptor>(p1, p2, p3, p4);
     case FEEDBACK_VECTOR_TYPE:
       return Op::template apply<FeedbackVector::BodyDescriptor>(p1, p2, p3, p4);
+    case COVERAGE_INFO_TYPE:
+      return Op::template apply<CoverageInfo::BodyDescriptor>(p1, p2, p3, p4);
     case JS_OBJECT_TYPE:
     case JS_ERROR_TYPE:
     case JS_ARGUMENTS_OBJECT_TYPE:
@@ -942,8 +979,8 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case JS_SPECIAL_API_OBJECT_TYPE:
     case JS_MESSAGE_OBJECT_TYPE:
     case JS_BOUND_FUNCTION_TYPE:
-    case JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE:
-    case JS_FINALIZATION_GROUP_TYPE:
+    case JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE:
+    case JS_FINALIZATION_REGISTRY_TYPE:
 #ifdef V8_INTL_SUPPORT
     case JS_V8_BREAK_ITERATOR_TYPE:
     case JS_COLLATOR_TYPE:
@@ -1063,6 +1100,12 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case SYNTHETIC_MODULE_TYPE:
       return Op::template apply<SyntheticModule::BodyDescriptor>(p1, p2, p3,
                                                                  p4);
+#define MAKE_TORQUE_BODY_DESCRIPTOR_APPLY(TYPE, TypeName) \
+  case TYPE:                                              \
+    return Op::template apply<TypeName::BodyDescriptor>(p1, p2, p3, p4);
+      TORQUE_BODY_DESCRIPTOR_LIST(MAKE_TORQUE_BODY_DESCRIPTOR_APPLY)
+#undef MAKE_TORQUE_BODY_DESCRIPTOR_APPLY
+
     default:
       PrintF("Unknown type: %d\n", type);
       UNREACHABLE();
diff --git a/deps/v8/src/objects/objects-body-descriptors.h b/deps/v8/src/objects/objects-body-descriptors.h
index 728708f436..13adf4c3db 100644
--- a/deps/v8/src/objects/objects-body-descriptors.h
+++ b/deps/v8/src/objects/objects-body-descriptors.h
@@ -180,6 +180,10 @@ class SubclassBodyDescriptor final : public BodyDescriptorBase {
   }
 };
 
+#define TORQUE_BODY_DESCRIPTOR_LIST_ADAPTER(V, TYPE, TypeName) V(TYPE, TypeName)
+#define TORQUE_BODY_DESCRIPTOR_LIST(V) \
+  TORQUE_BODY_DESCRIPTOR_LIST_GENERATOR(TORQUE_BODY_DESCRIPTOR_LIST_ADAPTER, V)
+
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/objects-definitions.h b/deps/v8/src/objects/objects-definitions.h
index 24176ac65c..a830e13ed1 100644
--- a/deps/v8/src/objects/objects-definitions.h
+++ b/deps/v8/src/objects/objects-definitions.h
@@ -159,9 +159,7 @@ namespace internal {
     wasm_indirect_function_table)                                             \
   V(_, WASM_JS_FUNCTION_DATA_TYPE, WasmJSFunctionData, wasm_js_function_data)
 
-#define STRUCT_LIST_GENERATOR(V, _) \
-  STRUCT_LIST_GENERATOR_BASE(V, _)  \
-  TORQUE_STRUCT_LIST_GENERATOR(V, _)
+#define STRUCT_LIST_GENERATOR(V, _) STRUCT_LIST_GENERATOR_BASE(V, _)
 
 // Adapts one STRUCT_LIST_GENERATOR entry to the STRUCT_LIST entry
 #define STRUCT_LIST_ADAPTER(V, NAME, Name, name) V(NAME, Name, name)
@@ -176,6 +174,15 @@ namespace internal {
 // Produces (Map, struct_name_map, StructNameMap) entries
 #define STRUCT_MAPS_LIST(V) STRUCT_LIST_GENERATOR(STRUCT_MAPS_LIST_ADAPTER, V)
 
+// Adapts one STRUCT_LIST_GENERATOR entry to the STRUCT_LIST entry
+#define TORQUE_INTERNAL_CLASS_LIST_MAPS_ADAPTER(V, NAME, Name, name) \
+  V(Map, name##_map, Name##Map)
+
+// Produces (NAME, Name, name) entries.
+#define TORQUE_INTERNAL_CLASS_MAPS_LIST(V) \
+  TORQUE_INTERNAL_CLASS_LIST_GENERATOR(    \
+      TORQUE_INTERNAL_CLASS_LIST_MAPS_ADAPTER, V)
+
 //
 // The following macros define list of allocation size objects and list of
 // their maps.
diff --git a/deps/v8/src/objects/objects-inl.h b/deps/v8/src/objects/objects-inl.h
index fdfb251823..9877b67c19 100644
--- a/deps/v8/src/objects/objects-inl.h
+++ b/deps/v8/src/objects/objects-inl.h
@@ -40,6 +40,7 @@
 #include "src/objects/smi-inl.h"
 #include "src/objects/tagged-field-inl.h"
 #include "src/objects/tagged-impl-inl.h"
+#include "src/objects/tagged-index.h"
 #include "src/objects/templates.h"
 #include "src/sanitizer/tsan.h"
 #include "torque-generated/class-definitions-tq-inl.h"
@@ -74,6 +75,10 @@ DEF_GETTER(HeapObject, IsClassBoilerplate, bool) {
   return IsFixedArrayExact(isolate);
 }
 
+bool Object::IsTaggedIndex() const {
+  return IsSmi() && TaggedIndex::IsValid(TaggedIndex(ptr()).value());
+}
+
 #define IS_TYPE_FUNCTION_DEF(type_)                                      \
   bool Object::Is##type_() const {                                       \
     return IsHeapObject() && HeapObject::cast(*this).Is##type_();        \
@@ -90,6 +95,9 @@ IS_TYPE_FUNCTION_DEF(SmallOrderedHashTable)
   bool Object::Is##Type(Isolate* isolate) const {                \
     return Is##Type(ReadOnlyRoots(isolate));                     \
   }                                                              \
+  bool Object::Is##Type(OffThreadIsolate* isolate) const {       \
+    return Is##Type(ReadOnlyRoots(isolate));                     \
+  }                                                              \
   bool Object::Is##Type(ReadOnlyRoots roots) const {             \
     return *this == roots.Value();                               \
   }                                                              \
@@ -99,6 +107,9 @@ IS_TYPE_FUNCTION_DEF(SmallOrderedHashTable)
   bool HeapObject::Is##Type(Isolate* isolate) const {            \
     return Object::Is##Type(isolate);                            \
   }                                                              \
+  bool HeapObject::Is##Type(OffThreadIsolate* isolate) const {   \
+    return Object::Is##Type(isolate);                            \
+  }                                                              \
   bool HeapObject::Is##Type(ReadOnlyRoots roots) const {         \
     return Object::Is##Type(roots);                              \
   }                                                              \
diff --git a/deps/v8/src/objects/objects.cc b/deps/v8/src/objects/objects.cc
index 9b53019297..c455629651 100644
--- a/deps/v8/src/objects/objects.cc
+++ b/deps/v8/src/objects/objects.cc
@@ -28,13 +28,17 @@
 #include "src/common/message-template.h"
 #include "src/date/date.h"
 #include "src/debug/debug.h"
+#include "src/diagnostics/code-tracer.h"
 #include "src/execution/arguments.h"
 #include "src/execution/execution.h"
 #include "src/execution/frames-inl.h"
 #include "src/execution/isolate-inl.h"
 #include "src/execution/microtask-queue.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/execution/protectors-inl.h"
+#include "src/heap/factory-inl.h"
 #include "src/heap/heap-inl.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/heap/read-only-heap.h"
 #include "src/ic/ic.h"
 #include "src/init/bootstrapper.h"
@@ -122,6 +126,7 @@
 
 #include "torque-generated/class-definitions-tq-inl.h"
 #include "torque-generated/internal-class-definitions-tq-inl.h"
+#include "torque-generated/objects-body-descriptors-tq-inl.h"
 
 namespace v8 {
 namespace internal {
@@ -581,7 +586,7 @@ MaybeHandle<Object> Object::ConvertToIndex(Isolate* isolate,
   if (input->IsUndefined(isolate)) return handle(Smi::zero(), isolate);
   ASSIGN_RETURN_ON_EXCEPTION(isolate, input, ToNumber(isolate, input), Object);
   if (input->IsSmi() && Smi::ToInt(*input) >= 0) return input;
-  double len = DoubleToInteger(input->Number()) + 0.0;
+  double len = DoubleToInteger(input->Number());
   auto js_len = isolate->factory()->NewNumber(len);
   if (len < 0.0 || len > kMaxSafeInteger) {
     THROW_NEW_ERROR(isolate, NewRangeError(error_index, js_len), Object);
@@ -1317,6 +1322,8 @@ FunctionTemplateRareData FunctionTemplateInfo::AllocateFunctionTemplateRareData(
       FUNCTION_TEMPLATE_RARE_DATA_TYPE, AllocationType::kOld);
   Handle<FunctionTemplateRareData> rare_data =
       i::Handle<FunctionTemplateRareData>::cast(struct_obj);
+  rare_data->set_c_function(Smi(0));
+  rare_data->set_c_signature(Smi(0));
   function_template_info->set_rare_data(*rare_data);
   return *rare_data;
 }
@@ -2152,7 +2159,8 @@ void ClassPositions::BriefPrintDetails(std::ostream& os) {
 }
 
 void ArrayBoilerplateDescription::BriefPrintDetails(std::ostream& os) {
-  os << " " << elements_kind() << ", " << Brief(constant_elements());
+  os << " " << ElementsKindToString(elements_kind()) << ", "
+     << Brief(constant_elements());
 }
 
 void CallableTask::BriefPrintDetails(std::ostream& os) {
@@ -2270,9 +2278,21 @@ int HeapObject::SizeFromMap(Map map) const {
     PreparseData data = PreparseData::unchecked_cast(*this);
     return PreparseData::SizeFor(data.data_length(), data.children_length());
   }
+#define MAKE_TORQUE_SIZE_FOR(TYPE, TypeName)             \
+  if (instance_type == TYPE) {                           \
+    TypeName instance = TypeName::unchecked_cast(*this); \
+    return TypeName::SizeFor(instance);                  \
+  }
+  TORQUE_BODY_DESCRIPTOR_LIST(MAKE_TORQUE_SIZE_FOR)
+#undef MAKE_TORQUE_SIZE_FOR
+
   if (instance_type == CODE_TYPE) {
     return Code::unchecked_cast(*this).CodeSize();
   }
+  if (instance_type == COVERAGE_INFO_TYPE) {
+    return CoverageInfo::SizeFor(
+        CoverageInfo::unchecked_cast(*this).slot_count());
+  }
   DCHECK_EQ(instance_type, EMBEDDER_DATA_ARRAY_TYPE);
   return EmbedderDataArray::SizeFor(
       EmbedderDataArray::unchecked_cast(*this).length());
@@ -4262,13 +4282,22 @@ Handle<FrameArray> FrameArray::EnsureSpace(Isolate* isolate,
       EnsureSpaceInFixedArray(isolate, array, length));
 }
 
-Handle<DescriptorArray> DescriptorArray::Allocate(Isolate* isolate,
+template <typename LocalIsolate>
+Handle<DescriptorArray> DescriptorArray::Allocate(LocalIsolate* isolate,
                                                   int nof_descriptors,
-                                                  int slack) {
+                                                  int slack,
+                                                  AllocationType allocation) {
   return nof_descriptors + slack == 0
              ? isolate->factory()->empty_descriptor_array()
-             : isolate->factory()->NewDescriptorArray(nof_descriptors, slack);
+             : isolate->factory()->NewDescriptorArray(nof_descriptors, slack,
+                                                      allocation);
 }
+template Handle<DescriptorArray> DescriptorArray::Allocate(
+    Isolate* isolate, int nof_descriptors, int slack,
+    AllocationType allocation);
+template Handle<DescriptorArray> DescriptorArray::Allocate(
+    OffThreadIsolate* isolate, int nof_descriptors, int slack,
+    AllocationType allocation);
 
 void DescriptorArray::Initialize(EnumCache enum_cache,
                                  HeapObject undefined_value,
@@ -4622,7 +4651,6 @@ uint32_t StringHasher::MakeArrayIndexHash(uint32_t value, int length) {
   value <<= String::ArrayIndexValueBits::kShift;
   value |= length << String::ArrayIndexLengthBits::kShift;
 
-  DCHECK_EQ(value & String::kIsNotArrayIndexMask, 0);
   DCHECK_EQ(value & String::kIsNotIntegerIndexMask, 0);
   DCHECK_EQ(length <= String::kMaxCachedArrayIndexLength,
             Name::ContainsCachedArrayIndex(value));
@@ -4700,8 +4728,9 @@ int Script::GetEvalPosition(Isolate* isolate, Handle<Script> script) {
   return position;
 }
 
-void Script::InitLineEnds(Handle<Script> script) {
-  Isolate* isolate = script->GetIsolate();
+template <typename LocalIsolate>
+// static
+void Script::InitLineEnds(LocalIsolate* isolate, Handle<Script> script) {
   if (!script->line_ends().IsUndefined(isolate)) return;
   DCHECK(script->type() != Script::TYPE_WASM ||
          script->source_mapping_url().IsString());
@@ -4720,11 +4749,17 @@ void Script::InitLineEnds(Handle<Script> script) {
   DCHECK(script->line_ends().IsFixedArray());
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void Script::InitLineEnds(
+    Isolate* isolate, Handle<Script> script);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void Script::InitLineEnds(
+    OffThreadIsolate* isolate, Handle<Script> script);
+
 bool Script::GetPositionInfo(Handle<Script> script, int position,
                              PositionInfo* info, OffsetFlag offset_flag) {
   // For wasm, we do not create an artificial line_ends array, but do the
   // translation directly.
-  if (script->type() != Script::TYPE_WASM) InitLineEnds(script);
+  if (script->type() != Script::TYPE_WASM)
+    InitLineEnds(script->GetIsolate(), script);
   return script->GetPositionInfo(position, info, offset_flag);
 }
 
@@ -4882,8 +4917,9 @@ Object Script::GetNameOrSourceURL() {
   return name();
 }
 
+template <typename LocalIsolate>
 MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
-    Isolate* isolate, const FunctionLiteral* fun) {
+    LocalIsolate* isolate, const FunctionLiteral* fun) {
   CHECK_NE(fun->function_literal_id(), kFunctionLiteralIdInvalid);
   // If this check fails, the problem is most probably the function id
   // renumbering done by AstFunctionLiteralIdReindexer; in particular, that
@@ -4898,6 +4934,10 @@ MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
   }
   return handle(SharedFunctionInfo::cast(heap_object), isolate);
 }
+template MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
+    Isolate* isolate, const FunctionLiteral* fun);
+template MaybeHandle<SharedFunctionInfo> Script::FindSharedFunctionInfo(
+    OffThreadIsolate* isolate, const FunctionLiteral* fun);
 
 Script::Iterator::Iterator(Isolate* isolate)
     : iterator_(isolate->heap()->script_list()) {}
@@ -4951,6 +4991,7 @@ void SharedFunctionInfo::Init(ReadOnlyRoots ro_roots, int unique_id) {
   // All flags default to false or 0, except ConstructAsBuiltinBit just because
   // we're using the kIllegal builtin.
   set_flags(ConstructAsBuiltinBit::encode(true));
+  set_flags2(0);
 
   UpdateFunctionMapIndex();
 
@@ -5316,15 +5357,17 @@ void SharedFunctionInfo::DisableOptimization(BailoutReason reason) {
           CodeDisableOptEvent(handle(abstract_code(), GetIsolate()),
                               handle(*this, GetIsolate())));
   if (FLAG_trace_opt) {
-    PrintF("[disabled optimization for ");
-    ShortPrint();
-    PrintF(", reason: %s]\n", GetBailoutReason(reason));
+    CodeTracer::Scope scope(GetIsolate()->GetCodeTracer());
+    PrintF(scope.file(), "[disabled optimization for ");
+    ShortPrint(scope.file());
+    PrintF(scope.file(), ", reason: %s]\n", GetBailoutReason(reason));
   }
 }
 
 // static
+template <typename LocalIsolate>
 void SharedFunctionInfo::InitFromFunctionLiteral(
-    Isolate* isolate, Handle<SharedFunctionInfo> shared_info,
+    LocalIsolate* isolate, Handle<SharedFunctionInfo> shared_info,
     FunctionLiteral* lit, bool is_toplevel) {
   DCHECK(!shared_info->name_or_scope_info().IsScopeInfo());
 
@@ -5344,6 +5387,14 @@ void SharedFunctionInfo::InitFromFunctionLiteral(
                  IsClassConstructor(lit->kind()));
   shared_info->set_requires_instance_members_initializer(
       lit->requires_instance_members_initializer());
+  DCHECK_IMPLIES(lit->class_scope_has_private_brand(),
+                 IsClassConstructor(lit->kind()));
+  shared_info->set_class_scope_has_private_brand(
+      lit->class_scope_has_private_brand());
+  DCHECK_IMPLIES(lit->has_static_private_methods_or_accessors(),
+                 IsClassConstructor(lit->kind()));
+  shared_info->set_has_static_private_methods_or_accessors(
+      lit->has_static_private_methods_or_accessors());
 
   shared_info->set_is_toplevel(is_toplevel);
   DCHECK(shared_info->outer_scope_info().IsTheHole());
@@ -5381,20 +5432,29 @@ void SharedFunctionInfo::InitFromFunctionLiteral(
 
   ProducedPreparseData* scope_data = lit->produced_preparse_data();
   if (scope_data != nullptr) {
-    Handle<PreparseData> preparse_data =
-        scope_data->Serialize(shared_info->GetIsolate());
+    Handle<PreparseData> preparse_data = scope_data->Serialize(isolate);
 
     data = isolate->factory()->NewUncompiledDataWithPreparseData(
-        lit->inferred_name(), lit->start_position(), lit->end_position(),
-        preparse_data);
+        lit->GetInferredName(isolate), lit->start_position(),
+        lit->end_position(), preparse_data);
   } else {
     data = isolate->factory()->NewUncompiledDataWithoutPreparseData(
-        lit->inferred_name(), lit->start_position(), lit->end_position());
+        lit->GetInferredName(isolate), lit->start_position(),
+        lit->end_position());
   }
 
   shared_info->set_uncompiled_data(*data);
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void SharedFunctionInfo::
+    InitFromFunctionLiteral<Isolate>(Isolate* isolate,
+                                     Handle<SharedFunctionInfo> shared_info,
+                                     FunctionLiteral* lit, bool is_toplevel);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void SharedFunctionInfo::
+    InitFromFunctionLiteral<OffThreadIsolate>(
+        OffThreadIsolate* isolate, Handle<SharedFunctionInfo> shared_info,
+        FunctionLiteral* lit, bool is_toplevel);
+
 uint16_t SharedFunctionInfo::get_property_estimate_from_literal(
     FunctionLiteral* literal) {
   int estimate = literal->expected_property_count();
@@ -5408,7 +5468,11 @@ uint16_t SharedFunctionInfo::get_property_estimate_from_literal(
 
 void SharedFunctionInfo::UpdateExpectedNofPropertiesFromEstimate(
     FunctionLiteral* literal) {
-  set_expected_nof_properties(get_property_estimate_from_literal(literal));
+  // Limit actual estimate to fit in a 8 bit field, we will never allocate
+  // more than this in any case.
+  STATIC_ASSERT(JSObject::kMaxInObjectProperties <= kMaxUInt8);
+  int estimate = get_property_estimate_from_literal(literal);
+  set_expected_nof_properties(std::min(estimate, kMaxUInt8));
 }
 
 void SharedFunctionInfo::UpdateAndFinalizeExpectedNofPropertiesFromEstimate(
@@ -5983,10 +6047,20 @@ MaybeHandle<Object> JSPromise::Resolve(Handle<JSPromise> promise,
 
   // 12. Perform EnqueueJob("PromiseJobs", PromiseResolveThenableJob,
   //                        «promise, resolution, thenAction»).
+
+  // According to HTML, we use the context of the then function (|thenAction|)
+  // as the context of the microtask. See step 3 of HTML's EnqueueJob:
+  // https://html.spec.whatwg.org/C/#enqueuejob(queuename,-job,-arguments)
+  Handle<NativeContext> then_context;
+  if (!JSReceiver::GetContextForMicrotask(Handle<JSReceiver>::cast(then_action))
+           .ToHandle(&then_context)) {
+    then_context = isolate->native_context();
+  }
+
   Handle<PromiseResolveThenableJobTask> task =
       isolate->factory()->NewPromiseResolveThenableJobTask(
           promise, Handle<JSReceiver>::cast(then_action),
-          Handle<JSReceiver>::cast(resolution), isolate->native_context());
+          Handle<JSReceiver>::cast(resolution), then_context);
   if (isolate->debug()->is_active() && resolution->IsJSPromise()) {
     // Mark the dependency of the new {promise} on the {resolution}.
     Object::SetProperty(isolate, resolution,
@@ -5994,8 +6068,7 @@ MaybeHandle<Object> JSPromise::Resolve(Handle<JSPromise> promise,
                         promise)
         .Check();
   }
-  MicrotaskQueue* microtask_queue =
-      isolate->native_context()->microtask_queue();
+  MicrotaskQueue* microtask_queue = then_context->microtask_queue();
   if (microtask_queue) microtask_queue->EnqueueMicrotask(*task);
 
   // 13. Return undefined.
@@ -6031,6 +6104,9 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
     Handle<PromiseReaction> reaction = Handle<PromiseReaction>::cast(task);
     reactions = handle(reaction->next(), isolate);
 
+    // According to HTML, we use the context of the appropriate handler as the
+    // context of the microtask. See step 3 of HTML's EnqueueJob:
+    // https://html.spec.whatwg.org/C/#enqueuejob(queuename,-job,-arguments)
     Handle<NativeContext> handler_context;
 
     Handle<HeapObject> primary_handler;
@@ -6043,17 +6119,18 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
       secondary_handler = handle(reaction->fulfill_handler(), isolate);
     }
 
+    bool has_handler_context = false;
     if (primary_handler->IsJSReceiver()) {
-      JSReceiver::GetContextForMicrotask(
-          Handle<JSReceiver>::cast(primary_handler))
-          .ToHandle(&handler_context);
+      has_handler_context = JSReceiver::GetContextForMicrotask(
+                                Handle<JSReceiver>::cast(primary_handler))
+                                .ToHandle(&handler_context);
     }
-    if (handler_context.is_null() && secondary_handler->IsJSReceiver()) {
-      JSReceiver::GetContextForMicrotask(
-          Handle<JSReceiver>::cast(secondary_handler))
-          .ToHandle(&handler_context);
+    if (!has_handler_context && secondary_handler->IsJSReceiver()) {
+      has_handler_context = JSReceiver::GetContextForMicrotask(
+                                Handle<JSReceiver>::cast(secondary_handler))
+                                .ToHandle(&handler_context);
     }
-    if (handler_context.is_null()) handler_context = isolate->native_context();
+    if (!has_handler_context) handler_context = isolate->native_context();
 
     STATIC_ASSERT(
         static_cast<int>(PromiseReaction::kSize) ==
@@ -6073,6 +6150,11 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
           static_cast<int>(PromiseReaction::kPromiseOrCapabilityOffset) ==
           static_cast<int>(
               PromiseFulfillReactionJobTask::kPromiseOrCapabilityOffset));
+      STATIC_ASSERT(
+          static_cast<int>(
+              PromiseReaction::kContinuationPreservedEmbedderDataOffset) ==
+          static_cast<int>(PromiseFulfillReactionJobTask::
+                               kContinuationPreservedEmbedderDataOffset));
     } else {
       DisallowHeapAllocation no_gc;
       task->synchronized_set_map(
@@ -6086,6 +6168,11 @@ Handle<Object> JSPromise::TriggerPromiseReactions(Isolate* isolate,
           static_cast<int>(PromiseReaction::kPromiseOrCapabilityOffset) ==
           static_cast<int>(
               PromiseRejectReactionJobTask::kPromiseOrCapabilityOffset));
+      STATIC_ASSERT(
+          static_cast<int>(
+              PromiseReaction::kContinuationPreservedEmbedderDataOffset) ==
+          static_cast<int>(PromiseRejectReactionJobTask::
+                               kContinuationPreservedEmbedderDataOffset));
     }
 
     MicrotaskQueue* microtask_queue = handler_context->microtask_queue();
@@ -6213,37 +6300,59 @@ void JSRegExp::MarkTierUpForNextExec() {
 
 namespace {
 
+bool IsLineTerminator(int c) {
+  // Expected to return true for '\n', '\r', 0x2028, and 0x2029.
+  return unibrow::IsLineTerminator(static_cast<unibrow::uchar>(c));
+}
+
+// TODO(jgruber): Consider merging CountAdditionalEscapeChars and
+// WriteEscapedRegExpSource into a single function to deduplicate dispatch logic
+// and move related code closer to each other.
 template <typename Char>
-int CountRequiredEscapes(Handle<String> source) {
+int CountAdditionalEscapeChars(Handle<String> source, bool* needs_escapes_out) {
   DisallowHeapAllocation no_gc;
   int escapes = 0;
+  bool needs_escapes = false;
   bool in_char_class = false;
   Vector<const Char> src = source->GetCharVector<Char>(no_gc);
   for (int i = 0; i < src.length(); i++) {
     const Char c = src[i];
     if (c == '\\') {
-      // Escape. Skip next character;
-      i++;
+      if (i + 1 < src.length() && IsLineTerminator(src[i + 1])) {
+        // This '\' is ignored since the next character itself will be escaped.
+        escapes--;
+      } else {
+        // Escape. Skip next character, which will be copied verbatim;
+        i++;
+      }
     } else if (c == '/' && !in_char_class) {
       // Not escaped forward-slash needs escape.
+      needs_escapes = true;
       escapes++;
     } else if (c == '[') {
       in_char_class = true;
     } else if (c == ']') {
       in_char_class = false;
     } else if (c == '\n') {
+      needs_escapes = true;
       escapes++;
     } else if (c == '\r') {
+      needs_escapes = true;
       escapes++;
     } else if (static_cast<int>(c) == 0x2028) {
+      needs_escapes = true;
       escapes += std::strlen("\\u2028") - 1;
     } else if (static_cast<int>(c) == 0x2029) {
+      needs_escapes = true;
       escapes += std::strlen("\\u2029") - 1;
     } else {
-      DCHECK(!unibrow::IsLineTerminator(static_cast<unibrow::uchar>(c)));
+      DCHECK(!IsLineTerminator(c));
     }
   }
   DCHECK(!in_char_class);
+  DCHECK_GE(escapes, 0);
+  DCHECK_IMPLIES(escapes != 0, needs_escapes);
+  *needs_escapes_out = needs_escapes;
   return escapes;
 }
 
@@ -6263,33 +6372,42 @@ Handle<StringType> WriteEscapedRegExpSource(Handle<String> source,
   int d = 0;
   bool in_char_class = false;
   while (s < src.length()) {
-    if (src[s] == '\\') {
-      // Escape. Copy this and next character.
-      dst[d++] = src[s++];
+    const Char c = src[s];
+    if (c == '\\') {
+      if (s + 1 < src.length() && IsLineTerminator(src[s + 1])) {
+        // This '\' is ignored since the next character itself will be escaped.
+        s++;
+        continue;
+      } else {
+        // Escape. Copy this and next character.
+        dst[d++] = src[s++];
+      }
       if (s == src.length()) break;
-    } else if (src[s] == '/' && !in_char_class) {
+    } else if (c == '/' && !in_char_class) {
       // Not escaped forward-slash needs escape.
       dst[d++] = '\\';
-    } else if (src[s] == '[') {
+    } else if (c == '[') {
       in_char_class = true;
-    } else if (src[s] == ']') {
+    } else if (c == ']') {
       in_char_class = false;
-    } else if (src[s] == '\n') {
+    } else if (c == '\n') {
       WriteStringToCharVector(dst, &d, "\\n");
       s++;
       continue;
-    } else if (src[s] == '\r') {
+    } else if (c == '\r') {
       WriteStringToCharVector(dst, &d, "\\r");
       s++;
       continue;
-    } else if (static_cast<int>(src[s]) == 0x2028) {
+    } else if (static_cast<int>(c) == 0x2028) {
       WriteStringToCharVector(dst, &d, "\\u2028");
       s++;
       continue;
-    } else if (static_cast<int>(src[s]) == 0x2029) {
+    } else if (static_cast<int>(c) == 0x2029) {
       WriteStringToCharVector(dst, &d, "\\u2029");
       s++;
       continue;
+    } else {
+      DCHECK(!IsLineTerminator(c));
     }
     dst[d++] = src[s++];
   }
@@ -6303,10 +6421,12 @@ MaybeHandle<String> EscapeRegExpSource(Isolate* isolate,
   DCHECK(source->IsFlat());
   if (source->length() == 0) return isolate->factory()->query_colon_string();
   bool one_byte = String::IsOneByteRepresentationUnderneath(*source);
-  int escapes = one_byte ? CountRequiredEscapes<uint8_t>(source)
-                         : CountRequiredEscapes<uc16>(source);
-  if (escapes == 0) return source;
-  int length = source->length() + escapes;
+  bool needs_escapes = false;
+  int additional_escape_chars =
+      one_byte ? CountAdditionalEscapeChars<uint8_t>(source, &needs_escapes)
+               : CountAdditionalEscapeChars<uc16>(source, &needs_escapes);
+  if (!needs_escapes) return source;
+  int length = source->length() + additional_escape_chars;
   if (one_byte) {
     Handle<SeqOneByteString> result;
     ASSIGN_RETURN_ON_EXCEPTION(isolate, result,
@@ -6461,8 +6581,9 @@ void HashTable<Derived, Shape>::IterateElements(ObjectVisitor* v) {
 }
 
 template <typename Derived, typename Shape>
+template <typename LocalIsolate>
 Handle<Derived> HashTable<Derived, Shape>::New(
-    Isolate* isolate, int at_least_space_for, AllocationType allocation,
+    LocalIsolate* isolate, int at_least_space_for, AllocationType allocation,
     MinimumCapacity capacity_option) {
   DCHECK_LE(0, at_least_space_for);
   DCHECK_IMPLIES(capacity_option == USE_CUSTOM_MINIMUM_CAPACITY,
@@ -6472,19 +6593,19 @@ Handle<Derived> HashTable<Derived, Shape>::New(
                      ? at_least_space_for
                      : ComputeCapacity(at_least_space_for);
   if (capacity > HashTable::kMaxCapacity) {
-    isolate->heap()->FatalProcessOutOfMemory("invalid table size");
+    isolate->FatalProcessOutOfHeapMemory("invalid table size");
   }
   return NewInternal(isolate, capacity, allocation);
 }
 
 template <typename Derived, typename Shape>
+template <typename LocalIsolate>
 Handle<Derived> HashTable<Derived, Shape>::NewInternal(
-    Isolate* isolate, int capacity, AllocationType allocation) {
-  Factory* factory = isolate->factory();
+    LocalIsolate* isolate, int capacity, AllocationType allocation) {
+  auto* factory = isolate->factory();
   int length = EntryToIndex(InternalIndex(capacity));
-  RootIndex map_root_index = Shape::GetMapRootIndex();
-  Handle<FixedArray> array =
-      factory->NewFixedArrayWithMap(map_root_index, length, allocation);
+  Handle<FixedArray> array = factory->NewFixedArrayWithMap(
+      Shape::GetMap(ReadOnlyRoots(isolate)), length, allocation);
   Handle<Derived> table = Handle<Derived>::cast(array);
 
   table->SetNumberOfElements(0);
@@ -6606,8 +6727,10 @@ void HashTable<Derived, Shape>::Rehash(ReadOnlyRoots roots) {
 }
 
 template <typename Derived, typename Shape>
+template <typename LocalIsolate>
 Handle<Derived> HashTable<Derived, Shape>::EnsureCapacity(
-    Isolate* isolate, Handle<Derived> table, int n, AllocationType allocation) {
+    LocalIsolate* isolate, Handle<Derived> table, int n,
+    AllocationType allocation) {
   if (table->HasSufficientCapacityToAdd(n)) return table;
 
   int capacity = table->Capacity();
@@ -6625,9 +6748,6 @@ Handle<Derived> HashTable<Derived, Shape>::EnsureCapacity(
   return new_table;
 }
 
-template bool
-HashTable<NameDictionary, NameDictionaryShape>::HasSufficientCapacityToAdd(int);
-
 template <typename Derived, typename Shape>
 bool HashTable<Derived, Shape>::HasSufficientCapacityToAdd(
     int number_of_additional_elements) {
@@ -6824,8 +6944,8 @@ Address LookupString(Isolate* isolate, String string, String source,
     return Smi::FromInt(String::ArrayIndexValueBits::decode(hash_field)).ptr();
   }
 
-  if ((hash_field & Name::kIsNotArrayIndexMask) == 0) {
-    // It is an indexed, but it's not cached.
+  if ((hash_field & Name::kIsNotIntegerIndexMask) == 0) {
+    // It is an index, but it's not cached.
     return Smi::FromInt(ResultSentinel::kUnsupported).ptr();
   }
 
@@ -6888,7 +7008,7 @@ Handle<StringSet> StringSet::Add(Isolate* isolate, Handle<StringSet> stringset,
                                  Handle<String> name) {
   if (!stringset->Has(isolate, name)) {
     stringset = EnsureCapacity(isolate, stringset);
-    uint32_t hash = ShapeT::Hash(isolate, *name);
+    uint32_t hash = ShapeT::Hash(ReadOnlyRoots(isolate), *name);
     InternalIndex entry = stringset->FindInsertionEntry(hash);
     stringset->set(EntryToIndex(entry), *name);
     stringset->ElementAdded();
@@ -7202,8 +7322,9 @@ void CompilationCacheTable::Remove(Object value) {
 }
 
 template <typename Derived, typename Shape>
+template <typename LocalIsolate>
 Handle<Derived> BaseNameDictionary<Derived, Shape>::New(
-    Isolate* isolate, int at_least_space_for, AllocationType allocation,
+    LocalIsolate* isolate, int at_least_space_for, AllocationType allocation,
     MinimumCapacity capacity_option) {
   DCHECK_LE(0, at_least_space_for);
   Handle<Derived> dict = Dictionary<Derived, Shape>::New(
@@ -7235,7 +7356,7 @@ int BaseNameDictionary<Derived, Shape>::NextEnumerationIndex(
 
       PropertyDetails details = dictionary->DetailsAt(index);
       PropertyDetails new_details = details.set_index(enum_index);
-      dictionary->DetailsAtPut(isolate, index, new_details);
+      dictionary->DetailsAtPut(index, new_details);
     }
 
     index = PropertyDetails::kInitialIndex + length;
@@ -7251,7 +7372,7 @@ Handle<Derived> Dictionary<Derived, Shape>::DeleteEntry(
     Isolate* isolate, Handle<Derived> dictionary, InternalIndex entry) {
   DCHECK(Shape::kEntrySize != 3 ||
          dictionary->DetailsAt(entry).IsConfigurable());
-  dictionary->ClearEntry(isolate, entry);
+  dictionary->ClearEntry(entry);
   dictionary->ElementRemoved();
   return Shrink(isolate, dictionary);
 }
@@ -7270,15 +7391,16 @@ Handle<Derived> Dictionary<Derived, Shape>::AtPut(Isolate* isolate,
 
   // We don't need to copy over the enumeration index.
   dictionary->ValueAtPut(entry, *value);
-  if (Shape::kEntrySize == 3) dictionary->DetailsAtPut(isolate, entry, details);
+  if (Shape::kEntrySize == 3) dictionary->DetailsAtPut(entry, details);
   return dictionary;
 }
 
 template <typename Derived, typename Shape>
+template <typename LocalIsolate>
 Handle<Derived>
 BaseNameDictionary<Derived, Shape>::AddNoUpdateNextEnumerationIndex(
-    Isolate* isolate, Handle<Derived> dictionary, Key key, Handle<Object> value,
-    PropertyDetails details, InternalIndex* entry_out) {
+    LocalIsolate* isolate, Handle<Derived> dictionary, Key key,
+    Handle<Object> value, PropertyDetails details, InternalIndex* entry_out) {
   // Insert element at empty or deleted entry.
   return Dictionary<Derived, Shape>::Add(isolate, dictionary, key, value,
                                          details, entry_out);
@@ -7303,14 +7425,16 @@ Handle<Derived> BaseNameDictionary<Derived, Shape>::Add(
 }
 
 template <typename Derived, typename Shape>
-Handle<Derived> Dictionary<Derived, Shape>::Add(Isolate* isolate,
+template <typename LocalIsolate>
+Handle<Derived> Dictionary<Derived, Shape>::Add(LocalIsolate* isolate,
                                                 Handle<Derived> dictionary,
                                                 Key key, Handle<Object> value,
                                                 PropertyDetails details,
                                                 InternalIndex* entry_out) {
-  uint32_t hash = Shape::Hash(isolate, key);
+  uint32_t hash = Shape::Hash(ReadOnlyRoots(isolate), key);
   // Validate that the key is absent.
-  SLOW_DCHECK(dictionary->FindEntry(isolate, key).is_not_found());
+  SLOW_DCHECK(
+      dictionary->FindEntry(ReadOnlyRoots(isolate), key).is_not_found());
   // Check whether the dictionary should be extended.
   dictionary = Derived::EnsureCapacity(isolate, dictionary);
 
@@ -7318,7 +7442,7 @@ Handle<Derived> Dictionary<Derived, Shape>::Add(Isolate* isolate,
   Handle<Object> k = Shape::AsHandle(isolate, key);
 
   InternalIndex entry = dictionary->FindInsertionEntry(hash);
-  dictionary->SetEntry(isolate, entry, *k, *value, details);
+  dictionary->SetEntry(entry, *k, *value, details);
   DCHECK(dictionary->KeyAt(entry).IsNumber() ||
          Shape::Unwrap(dictionary->KeyAt(entry)).IsUniqueName());
   dictionary->ElementAdded();
@@ -7853,7 +7977,7 @@ Handle<PropertyCell> PropertyCell::InvalidateEntry(
   details = details.set_cell_type(PropertyCellType::kInvalidated);
   cell->set_property_details(details);
   cell->dependent_code().DeoptimizeDependentCodeGroup(
-      isolate, DependentCode::kPropertyCellChangedGroup);
+      DependentCode::kPropertyCellChangedGroup);
   return new_cell;
 }
 
@@ -7954,7 +8078,7 @@ Handle<PropertyCell> PropertyCell::PrepareForValue(
   if (!invalidate && (old_type != new_type ||
                       original_details.IsReadOnly() != details.IsReadOnly())) {
     cell->dependent_code().DeoptimizeDependentCodeGroup(
-        isolate, DependentCode::kPropertyCellChangedGroup);
+        DependentCode::kPropertyCellChangedGroup);
   }
   return cell;
 }
@@ -7967,7 +8091,7 @@ void PropertyCell::SetValueWithInvalidation(Isolate* isolate,
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     cell->dependent_code().DeoptimizeDependentCodeGroup(
-        isolate, DependentCode::kPropertyCellChangedGroup);
+        DependentCode::kPropertyCellChangedGroup);
   }
 }
 
@@ -8109,92 +8233,112 @@ Address Smi::LexicographicCompare(Isolate* isolate, Smi x, Smi y) {
 // Please note this list is compiler dependent.
 // Keep this at the end of this file
 
-template class HashTable<StringTable, StringTableShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) HashTable<CompilationCacheTable, CompilationCacheShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) HashTable<ObjectHashTable, ObjectHashTableShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) HashTable<ObjectHashSet, ObjectHashSetShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    ObjectHashTableBase<ObjectHashTable, ObjectHashTableShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) HashTable<EphemeronHashTable, EphemeronHashTableShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    ObjectHashTableBase<EphemeronHashTable, EphemeronHashTableShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    BaseNameDictionary<NameDictionary, NameDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    BaseNameDictionary<GlobalDictionary, GlobalDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    Dictionary<NameDictionary, NameDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    Dictionary<GlobalDictionary, GlobalDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(
-    V8_EXPORT_PRIVATE) HashTable<NumberDictionary, NumberDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    Dictionary<NumberDictionary, NumberDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    HashTable<SimpleNumberDictionary, SimpleNumberDictionaryShape>;
-
-template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
-    Dictionary<SimpleNumberDictionary, SimpleNumberDictionaryShape>;
-
-template Handle<NameDictionary>
-HashTable<NameDictionary, NameDictionaryShape>::New(Isolate*, int,
-                                                    AllocationType,
-                                                    MinimumCapacity);
-
-template V8_EXPORT_PRIVATE Handle<NameDictionary>
-HashTable<NameDictionary, NameDictionaryShape>::Shrink(Isolate* isolate,
-                                                       Handle<NameDictionary>,
-                                                       int additionalCapacity);
-
-template void HashTable<GlobalDictionary, GlobalDictionaryShape>::Rehash(
-    ReadOnlyRoots roots);
-
-Maybe<bool> JSFinalizationGroup::Cleanup(
-    Isolate* isolate, Handle<JSFinalizationGroup> finalization_group,
+#define EXTERN_DEFINE_HASH_TABLE(DERIVED, SHAPE)                            \
+  template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)                  \
+      HashTable<DERIVED, SHAPE>;                                            \
+                                                                            \
+  template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) Handle<DERIVED>        \
+  HashTable<DERIVED, SHAPE>::New(Isolate*, int, AllocationType,             \
+                                 MinimumCapacity);                          \
+  template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) Handle<DERIVED>        \
+  HashTable<DERIVED, SHAPE>::New(OffThreadIsolate*, int, AllocationType,    \
+                                 MinimumCapacity);                          \
+                                                                            \
+  template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) Handle<DERIVED>        \
+  HashTable<DERIVED, SHAPE>::EnsureCapacity(Isolate*, Handle<DERIVED>, int, \
+                                            AllocationType);                \
+  template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) Handle<DERIVED>        \
+  HashTable<DERIVED, SHAPE>::EnsureCapacity(                                \
+      OffThreadIsolate*, Handle<DERIVED>, int, AllocationType);
+
+#define EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE(DERIVED, SHAPE) \
+  EXTERN_DEFINE_HASH_TABLE(DERIVED, SHAPE)                   \
+  template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)   \
+      ObjectHashTableBase<DERIVED, SHAPE>;
+
+#define EXTERN_DEFINE_DICTIONARY(DERIVED, SHAPE)                               \
+  EXTERN_DEFINE_HASH_TABLE(DERIVED, SHAPE)                                     \
+  template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)                     \
+      Dictionary<DERIVED, SHAPE>;                                              \
+                                                                               \
+  template V8_EXPORT_PRIVATE Handle<DERIVED> Dictionary<DERIVED, SHAPE>::Add(  \
+      Isolate* isolate, Handle<DERIVED>, Key, Handle<Object>, PropertyDetails, \
+      InternalIndex*);                                                         \
+  template V8_EXPORT_PRIVATE Handle<DERIVED> Dictionary<DERIVED, SHAPE>::Add(  \
+      OffThreadIsolate* isolate, Handle<DERIVED>, Key, Handle<Object>,         \
+      PropertyDetails, InternalIndex*);
+
+#define EXTERN_DEFINE_BASE_NAME_DICTIONARY(DERIVED, SHAPE)                     \
+  EXTERN_DEFINE_DICTIONARY(DERIVED, SHAPE)                                     \
+  template class EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)                     \
+      BaseNameDictionary<DERIVED, SHAPE>;                                      \
+                                                                               \
+  template V8_EXPORT_PRIVATE Handle<DERIVED>                                   \
+  BaseNameDictionary<DERIVED, SHAPE>::New(Isolate*, int, AllocationType,       \
+                                          MinimumCapacity);                    \
+  template V8_EXPORT_PRIVATE Handle<DERIVED>                                   \
+  BaseNameDictionary<DERIVED, SHAPE>::New(OffThreadIsolate*, int,              \
+                                          AllocationType, MinimumCapacity);    \
+                                                                               \
+  template Handle<DERIVED>                                                     \
+  BaseNameDictionary<DERIVED, SHAPE>::AddNoUpdateNextEnumerationIndex(         \
+      Isolate* isolate, Handle<DERIVED>, Key, Handle<Object>, PropertyDetails, \
+      InternalIndex*);                                                         \
+  template Handle<DERIVED>                                                     \
+  BaseNameDictionary<DERIVED, SHAPE>::AddNoUpdateNextEnumerationIndex(         \
+      OffThreadIsolate* isolate, Handle<DERIVED>, Key, Handle<Object>,         \
+      PropertyDetails, InternalIndex*);
+
+EXTERN_DEFINE_HASH_TABLE(StringTable, StringTableShape)
+EXTERN_DEFINE_HASH_TABLE(StringSet, StringSetShape)
+EXTERN_DEFINE_HASH_TABLE(CompilationCacheTable, CompilationCacheShape)
+EXTERN_DEFINE_HASH_TABLE(ObjectHashSet, ObjectHashSetShape)
+
+EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE(ObjectHashTable, ObjectHashTableShape)
+EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE(EphemeronHashTable,
+                                     EphemeronHashTableShape)
+
+EXTERN_DEFINE_DICTIONARY(SimpleNumberDictionary, SimpleNumberDictionaryShape)
+EXTERN_DEFINE_DICTIONARY(NumberDictionary, NumberDictionaryShape)
+
+EXTERN_DEFINE_BASE_NAME_DICTIONARY(NameDictionary, NameDictionaryShape)
+EXTERN_DEFINE_BASE_NAME_DICTIONARY(GlobalDictionary, GlobalDictionaryShape)
+
+#undef EXTERN_DEFINE_HASH_TABLE
+#undef EXTERN_DEFINE_OBJECT_BASE_HASH_TABLE
+#undef EXTERN_DEFINE_DICTIONARY
+#undef EXTERN_DEFINE_BASE_NAME_DICTIONARY
+
+Maybe<bool> JSFinalizationRegistry::Cleanup(
+    Isolate* isolate, Handle<JSFinalizationRegistry> finalization_registry,
     Handle<Object> cleanup) {
   DCHECK(cleanup->IsCallable());
   // Attempt to shrink key_map now, as unregister tokens are held weakly and the
   // map is not shrinkable when sweeping dead tokens during GC itself.
-  if (!finalization_group->key_map().IsUndefined(isolate)) {
-    Handle<SimpleNumberDictionary> key_map = handle(
-        SimpleNumberDictionary::cast(finalization_group->key_map()), isolate);
+  if (!finalization_registry->key_map().IsUndefined(isolate)) {
+    Handle<SimpleNumberDictionary> key_map =
+        handle(SimpleNumberDictionary::cast(finalization_registry->key_map()),
+               isolate);
     key_map = SimpleNumberDictionary::Shrink(isolate, key_map);
-    finalization_group->set_key_map(*key_map);
+    finalization_registry->set_key_map(*key_map);
   }
 
   // It's possible that the cleared_cells list is empty, since
-  // FinalizationGroup.unregister() removed all its elements before this task
+  // FinalizationRegistry.unregister() removed all its elements before this task
   // ran. In that case, don't call the cleanup function.
-  if (!finalization_group->cleared_cells().IsUndefined(isolate)) {
+  if (!finalization_registry->cleared_cells().IsUndefined(isolate)) {
     // Construct the iterator.
-    Handle<JSFinalizationGroupCleanupIterator> iterator;
+    Handle<JSFinalizationRegistryCleanupIterator> iterator;
     {
       Handle<Map> cleanup_iterator_map(
           isolate->native_context()
-              ->js_finalization_group_cleanup_iterator_map(),
+              ->js_finalization_registry_cleanup_iterator_map(),
           isolate);
-      iterator = Handle<JSFinalizationGroupCleanupIterator>::cast(
+      iterator = Handle<JSFinalizationRegistryCleanupIterator>::cast(
           isolate->factory()->NewJSObjectFromMap(
               cleanup_iterator_map, AllocationType::kYoung,
               Handle<AllocationSite>::null()));
-      iterator->set_finalization_group(*finalization_group);
+      iterator->set_finalization_registry(*finalization_registry);
     }
     Handle<Object> args[] = {iterator};
     if (Execution::Call(
diff --git a/deps/v8/src/objects/objects.h b/deps/v8/src/objects/objects.h
index 1fa1dde37a..ef437446fd 100644
--- a/deps/v8/src/objects/objects.h
+++ b/deps/v8/src/objects/objects.h
@@ -38,6 +38,7 @@
 // Inheritance hierarchy:
 // - Object
 //   - Smi          (immediate small integer)
+//   - TaggedIndex  (properly sign-extended immediate small integer)
 //   - HeapObject   (superclass for everything allocated in the heap)
 //     - JSReceiver  (suitable for property access)
 //       - JSObject
@@ -194,6 +195,7 @@
 namespace v8 {
 namespace internal {
 
+class OffThreadIsolate;
 struct InliningPosition;
 class PropertyDescriptorObject;
 
@@ -274,6 +276,8 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   constexpr Object() : TaggedImpl(kNullAddress) {}
   explicit constexpr Object(Address ptr) : TaggedImpl(ptr) {}
 
+  V8_INLINE bool IsTaggedIndex() const;
+
 #define IS_TYPE_FUNCTION_DECL(Type) \
   V8_INLINE bool Is##Type() const;  \
   V8_INLINE bool Is##Type(const Isolate* isolate) const;
@@ -282,12 +286,14 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   IS_TYPE_FUNCTION_DECL(HashTableBase)
   IS_TYPE_FUNCTION_DECL(SmallOrderedHashTable)
 #undef IS_TYPE_FUNCTION_DECL
+  V8_INLINE bool IsNumber(ReadOnlyRoots roots) const;
 
 // Oddball checks are faster when they are raw pointer comparisons, so the
 // isolate/read-only roots overloads should be preferred where possible.
-#define IS_TYPE_FUNCTION_DECL(Type, Value)            \
-  V8_INLINE bool Is##Type(Isolate* isolate) const;    \
-  V8_INLINE bool Is##Type(ReadOnlyRoots roots) const; \
+#define IS_TYPE_FUNCTION_DECL(Type, Value)                  \
+  V8_INLINE bool Is##Type(Isolate* isolate) const;          \
+  V8_INLINE bool Is##Type(OffThreadIsolate* isolate) const; \
+  V8_INLINE bool Is##Type(ReadOnlyRoots roots) const;       \
   V8_INLINE bool Is##Type() const;
   ODDBALL_LIST(IS_TYPE_FUNCTION_DECL)
   IS_TYPE_FUNCTION_DECL(NullOrUndefined, /* unused */)
@@ -696,16 +702,17 @@ class Object : public TaggedImpl<HeapObjectReferenceType::STRONG, Address> {
   ConvertToString(Isolate* isolate, Handle<Object> input);
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToNumberOrNumeric(
       Isolate* isolate, Handle<Object> input, Conversion mode);
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToInteger(
-      Isolate* isolate, Handle<Object> input);
+  V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  ConvertToInteger(Isolate* isolate, Handle<Object> input);
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToInt32(
       Isolate* isolate, Handle<Object> input);
   V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToUint32(
       Isolate* isolate, Handle<Object> input);
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToLength(
-      Isolate* isolate, Handle<Object> input);
-  V8_WARN_UNUSED_RESULT static MaybeHandle<Object> ConvertToIndex(
-      Isolate* isolate, Handle<Object> input, MessageTemplate error_index);
+  V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  ConvertToLength(Isolate* isolate, Handle<Object> input);
+  V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object>
+  ConvertToIndex(Isolate* isolate, Handle<Object> input,
+                 MessageTemplate error_index);
 };
 
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, const Object& obj);
diff --git a/deps/v8/src/objects/oddball-inl.h b/deps/v8/src/objects/oddball-inl.h
index bcca03ddca..4b274097b8 100644
--- a/deps/v8/src/objects/oddball-inl.h
+++ b/deps/v8/src/objects/oddball-inl.h
@@ -25,13 +25,9 @@ void Oddball::set_to_number_raw_as_bits(uint64_t bits) {
   base::WriteUnalignedValue<uint64_t>(field_address(kToNumberRawOffset), bits);
 }
 
-byte Oddball::kind() const {
-  return Smi::ToInt(TorqueGeneratedOddball::kind());
-}
+byte Oddball::kind() const { return TorqueGeneratedOddball::kind(); }
 
-void Oddball::set_kind(byte value) {
-  TorqueGeneratedOddball::set_kind(Smi::FromInt(value));
-}
+void Oddball::set_kind(byte value) { TorqueGeneratedOddball::set_kind(value); }
 
 // static
 Handle<Object> Oddball::ToNumber(Isolate* isolate, Handle<Oddball> input) {
diff --git a/deps/v8/src/objects/ordered-hash-table-inl.h b/deps/v8/src/objects/ordered-hash-table-inl.h
index f6b8f972a9..6edd5c3cda 100644
--- a/deps/v8/src/objects/ordered-hash-table-inl.h
+++ b/deps/v8/src/objects/ordered-hash-table-inl.h
@@ -73,28 +73,28 @@ OBJECT_CONSTRUCTORS_IMPL(SmallOrderedHashMap,
 OBJECT_CONSTRUCTORS_IMPL(SmallOrderedNameDictionary,
                          SmallOrderedHashTable<SmallOrderedNameDictionary>)
 
-RootIndex OrderedHashSet::GetMapRootIndex() {
-  return RootIndex::kOrderedHashSetMap;
+Handle<Map> OrderedHashSet::GetMap(ReadOnlyRoots roots) {
+  return roots.ordered_hash_set_map_handle();
 }
 
-RootIndex OrderedHashMap::GetMapRootIndex() {
-  return RootIndex::kOrderedHashMapMap;
+Handle<Map> OrderedHashMap::GetMap(ReadOnlyRoots roots) {
+  return roots.ordered_hash_map_map_handle();
 }
 
-RootIndex OrderedNameDictionary::GetMapRootIndex() {
-  return RootIndex::kOrderedNameDictionaryMap;
+Handle<Map> OrderedNameDictionary::GetMap(ReadOnlyRoots roots) {
+  return roots.ordered_name_dictionary_map_handle();
 }
 
-RootIndex SmallOrderedNameDictionary::GetMapRootIndex() {
-  return RootIndex::kSmallOrderedNameDictionaryMap;
+Handle<Map> SmallOrderedNameDictionary::GetMap(ReadOnlyRoots roots) {
+  return roots.small_ordered_name_dictionary_map_handle();
 }
 
-RootIndex SmallOrderedHashMap::GetMapRootIndex() {
-  return RootIndex::kSmallOrderedHashMapMap;
+Handle<Map> SmallOrderedHashMap::GetMap(ReadOnlyRoots roots) {
+  return roots.small_ordered_hash_map_map_handle();
 }
 
-RootIndex SmallOrderedHashSet::GetMapRootIndex() {
-  return RootIndex::kSmallOrderedHashSetMap;
+Handle<Map> SmallOrderedHashSet::GetMap(ReadOnlyRoots roots) {
+  return roots.small_ordered_hash_set_map_handle();
 }
 
 inline Object OrderedHashMap::ValueAt(int entry) {
diff --git a/deps/v8/src/objects/ordered-hash-table.cc b/deps/v8/src/objects/ordered-hash-table.cc
index 962224024e..cbf3ba373b 100644
--- a/deps/v8/src/objects/ordered-hash-table.cc
+++ b/deps/v8/src/objects/ordered-hash-table.cc
@@ -9,6 +9,7 @@
 #include "src/objects/js-collection-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/ordered-hash-table-inl.h"
+#include "src/roots/roots.h"
 
 namespace v8 {
 namespace internal {
@@ -27,7 +28,7 @@ MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Allocate(
   }
   int num_buckets = capacity / kLoadFactor;
   Handle<FixedArray> backing_store = isolate->factory()->NewFixedArrayWithMap(
-      Derived::GetMapRootIndex(),
+      Derived::GetMap(ReadOnlyRoots(isolate)),
       HashTableStartIndex() + num_buckets + (capacity * kEntrySize),
       allocation);
   Handle<Derived> table = Handle<Derived>::cast(backing_store);
@@ -397,10 +398,10 @@ MaybeHandle<OrderedNameDictionary> OrderedNameDictionary::Add(
   return table;
 }
 
-void OrderedNameDictionary::SetEntry(Isolate* isolate, int entry, Object key,
-                                     Object value, PropertyDetails details) {
+void OrderedNameDictionary::SetEntry(int entry, Object key, Object value,
+                                     PropertyDetails details) {
   DisallowHeapAllocation gc;
-  DCHECK_IMPLIES(!key.IsName(), key.IsTheHole(isolate));
+  DCHECK_IMPLIES(!key.IsName(), key.IsTheHole());
   DisallowHeapAllocation no_gc;
   int index = EntryToIndex(entry);
   this->set(index, key);
@@ -418,7 +419,7 @@ Handle<OrderedNameDictionary> OrderedNameDictionary::DeleteEntry(
 
   Object hole = ReadOnlyRoots(isolate).the_hole_value();
   PropertyDetails details = PropertyDetails::Empty();
-  table->SetEntry(isolate, entry, hole, hole, details);
+  table->SetEntry(entry, hole, hole, details);
 
   int nof = table->NumberOfElements();
   table->SetNumberOfElements(nof - 1);
@@ -717,10 +718,9 @@ MaybeHandle<SmallOrderedNameDictionary> SmallOrderedNameDictionary::Add(
   return table;
 }
 
-void SmallOrderedNameDictionary::SetEntry(Isolate* isolate, int entry,
-                                          Object key, Object value,
+void SmallOrderedNameDictionary::SetEntry(int entry, Object key, Object value,
                                           PropertyDetails details) {
-  DCHECK_IMPLIES(!key.IsName(), key.IsTheHole(isolate));
+  DCHECK_IMPLIES(!key.IsName(), key.IsTheHole());
   SetDataEntry(entry, SmallOrderedNameDictionary::kValueIndex, value);
   SetDataEntry(entry, SmallOrderedNameDictionary::kKeyIndex, key);
 
@@ -765,7 +765,7 @@ Handle<SmallOrderedNameDictionary> SmallOrderedNameDictionary::DeleteEntry(
     DisallowHeapAllocation no_gc;
     Object hole = ReadOnlyRoots(isolate).the_hole_value();
     PropertyDetails details = PropertyDetails::Empty();
-    table->SetEntry(isolate, entry, hole, hole, details);
+    table->SetEntry(entry, hole, hole, details);
 
     int nof = table->NumberOfElements();
     table->SetNumberOfElements(nof - 1);
@@ -1159,17 +1159,17 @@ MaybeHandle<HeapObject> OrderedNameDictionaryHandler::Add(
       isolate, Handle<OrderedNameDictionary>::cast(table), key, value, details);
 }
 
-void OrderedNameDictionaryHandler::SetEntry(Isolate* isolate, HeapObject table,
-                                            int entry, Object key, Object value,
+void OrderedNameDictionaryHandler::SetEntry(HeapObject table, int entry,
+                                            Object key, Object value,
                                             PropertyDetails details) {
   DisallowHeapAllocation no_gc;
   if (table.IsSmallOrderedNameDictionary()) {
-    return SmallOrderedNameDictionary::cast(table).SetEntry(isolate, entry, key,
-                                                            value, details);
+    return SmallOrderedNameDictionary::cast(table).SetEntry(entry, key, value,
+                                                            details);
   }
 
   DCHECK(table.IsOrderedNameDictionary());
-  return OrderedNameDictionary::cast(table).SetEntry(isolate, entry, key, value,
+  return OrderedNameDictionary::cast(table).SetEntry(entry, key, value,
                                                      details);
 }
 
diff --git a/deps/v8/src/objects/ordered-hash-table.h b/deps/v8/src/objects/ordered-hash-table.h
index 590846f130..b587960432 100644
--- a/deps/v8/src/objects/ordered-hash-table.h
+++ b/deps/v8/src/objects/ordered-hash-table.h
@@ -248,7 +248,7 @@ class V8_EXPORT_PRIVATE OrderedHashSet
       Isolate* isolate, int capacity,
       AllocationType allocation = AllocationType::kYoung);
   static HeapObject GetEmpty(ReadOnlyRoots ro_roots);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static inline bool Is(Handle<HeapObject> table);
   static const int kPrefixSize = 0;
 
@@ -280,7 +280,7 @@ class V8_EXPORT_PRIVATE OrderedHashMap
   static Address GetHash(Isolate* isolate, Address raw_key);
 
   static HeapObject GetEmpty(ReadOnlyRoots ro_roots);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static inline bool Is(Handle<HeapObject> table);
 
   static const int kValueOffset = 1;
@@ -602,7 +602,7 @@ class SmallOrderedHashSet : public SmallOrderedHashTable<SmallOrderedHashSet> {
   V8_EXPORT_PRIVATE bool HasKey(Isolate* isolate, Handle<Object> key);
 
   static inline bool Is(Handle<HeapObject> table);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static Handle<SmallOrderedHashSet> Rehash(Isolate* isolate,
                                             Handle<SmallOrderedHashSet> table,
                                             int new_capacity);
@@ -635,7 +635,7 @@ class SmallOrderedHashMap : public SmallOrderedHashTable<SmallOrderedHashMap> {
                                        SmallOrderedHashMap table, Object key);
   V8_EXPORT_PRIVATE bool HasKey(Isolate* isolate, Handle<Object> key);
   static inline bool Is(Handle<HeapObject> table);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 
   static Handle<SmallOrderedHashMap> Rehash(Isolate* isolate,
                                             Handle<SmallOrderedHashMap> table,
@@ -701,8 +701,8 @@ class OrderedNameDictionary
       Isolate* isolate, Handle<OrderedNameDictionary> table, Handle<Name> key,
       Handle<Object> value, PropertyDetails details);
 
-  V8_EXPORT_PRIVATE void SetEntry(Isolate* isolate, int entry, Object key,
-                                  Object value, PropertyDetails details);
+  V8_EXPORT_PRIVATE void SetEntry(int entry, Object key, Object value,
+                                  PropertyDetails details);
 
   V8_EXPORT_PRIVATE static Handle<OrderedNameDictionary> DeleteEntry(
       Isolate* isolate, Handle<OrderedNameDictionary> table, int entry);
@@ -730,7 +730,7 @@ class OrderedNameDictionary
   inline int Hash();
 
   static HeapObject GetEmpty(ReadOnlyRoots ro_roots);
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static inline bool Is(Handle<HeapObject> table);
 
   static const int kValueOffset = 1;
@@ -756,8 +756,8 @@ class V8_EXPORT_PRIVATE OrderedNameDictionaryHandler
   static Handle<HeapObject> DeleteEntry(Isolate* isolate,
                                         Handle<HeapObject> table, int entry);
   static int FindEntry(Isolate* isolate, HeapObject table, Name key);
-  static void SetEntry(Isolate* isolate, HeapObject table, int entry,
-                       Object key, Object value, PropertyDetails details);
+  static void SetEntry(HeapObject table, int entry, Object key, Object value,
+                       PropertyDetails details);
 
   // Returns the value for entry.
   static Object ValueAt(HeapObject table, int entry);
@@ -829,10 +829,10 @@ class SmallOrderedNameDictionary
       Isolate* isolate, Handle<SmallOrderedNameDictionary> table,
       Handle<Name> key, Handle<Object> value, PropertyDetails details);
 
-  V8_EXPORT_PRIVATE void SetEntry(Isolate* isolate, int entry, Object key,
-                                  Object value, PropertyDetails details);
+  V8_EXPORT_PRIVATE void SetEntry(int entry, Object key, Object value,
+                                  PropertyDetails details);
 
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
   static inline bool Is(Handle<HeapObject> table);
 
   OBJECT_CONSTRUCTORS(SmallOrderedNameDictionary,
diff --git a/deps/v8/src/objects/ordered-hash-table.tq b/deps/v8/src/objects/ordered-hash-table.tq
index 7c40cb204e..d1b58d93eb 100644
--- a/deps/v8/src/objects/ordered-hash-table.tq
+++ b/deps/v8/src/objects/ordered-hash-table.tq
@@ -27,7 +27,7 @@ const kSmallOrderedHashSetMap: Map = SmallOrderedHashSetMapConstant();
 extern class SmallOrderedHashSet extends SmallOrderedHashTable {
   number_of_elements: uint8;
   number_of_deleted_elements: uint8;
-  number_of_buckets: uint8;
+  const number_of_buckets: uint8;
   @if(TAGGED_SIZE_8_BYTES) padding[5]: uint8;
   @ifnot(TAGGED_SIZE_8_BYTES) padding[1]: uint8;
   data_table[Convert<intptr>(number_of_buckets) * kSmallOrderedHashTableLoadFactor]:
@@ -66,7 +66,7 @@ const kSmallOrderedHashMapMap: Map = SmallOrderedHashMapMapConstant();
 extern class SmallOrderedHashMap extends SmallOrderedHashTable {
   number_of_elements: uint8;
   number_of_deleted_elements: uint8;
-  number_of_buckets: uint8;
+  const number_of_buckets: uint8;
   @if(TAGGED_SIZE_8_BYTES) padding[5]: uint8;
   @ifnot(TAGGED_SIZE_8_BYTES) padding[1]: uint8;
   data_table[Convert<intptr>(number_of_buckets) * kSmallOrderedHashTableLoadFactor]:
@@ -104,7 +104,7 @@ extern class SmallOrderedNameDictionary extends SmallOrderedHashTable {
   hash: int32;
   number_of_elements: uint8;
   number_of_deleted_elements: uint8;
-  number_of_buckets: uint8;
+  const number_of_buckets: uint8;
   padding: uint8;
   data_table[Convert<intptr>(number_of_buckets) * kSmallOrderedHashTableLoadFactor]:
       NameDictionaryEntry;
diff --git a/deps/v8/src/objects/promise.tq b/deps/v8/src/objects/promise.tq
index a1638e221a..391f742e44 100644
--- a/deps/v8/src/objects/promise.tq
+++ b/deps/v8/src/objects/promise.tq
@@ -22,6 +22,8 @@ const kPromiseReactionFulfillHandlerOffset: constexpr int31
     generates 'PromiseReaction::kFulfillHandlerOffset';
 const kPromiseReactionPromiseOrCapabilityOffset: constexpr int31
     generates 'PromiseReaction::kPromiseOrCapabilityOffset';
+const kPromiseReactionContinuationPreservedEmbedderDataOffset: constexpr int31
+    generates 'PromiseReaction::kContinuationPreservedEmbedderDataOffset';
 
 @generateCppClass
 extern class PromiseReaction extends Struct {
@@ -31,6 +33,7 @@ extern class PromiseReaction extends Struct {
   // Either a JSPromise (in case of native promises), a PromiseCapability
   // (general case), or undefined (in case of await).
   promise_or_capability: JSPromise|PromiseCapability|Undefined;
+  continuation_preserved_embedder_data: Object|Undefined;
 }
 
 // PromiseReactionJobTask constants
@@ -40,6 +43,10 @@ const kPromiseReactionJobTaskHandlerOffset: constexpr int31
     generates 'PromiseReactionJobTask::kHandlerOffset';
 const kPromiseReactionJobTaskPromiseOrCapabilityOffset: constexpr int31
     generates 'PromiseReactionJobTask::kPromiseOrCapabilityOffset';
+const kPromiseReactionJobTaskContinuationPreservedEmbedderDataOffset:
+    constexpr int31
+    generates 'PromiseReactionJobTask::kContinuationPreservedEmbedderDataOffset'
+    ;
 
 @abstract
 @generateCppClass
@@ -50,6 +57,7 @@ extern class PromiseReactionJobTask extends Microtask {
   // Either a JSPromise (in case of native promises), a PromiseCapability
   // (general case), or undefined (in case of await).
   promise_or_capability: JSPromise|PromiseCapability|Undefined;
+  continuation_preserved_embedder_data: Object|Undefined;
 }
 
 @generateCppClass
diff --git a/deps/v8/src/objects/property-descriptor-object.h b/deps/v8/src/objects/property-descriptor-object.h
index 2172c0002e..a0cd895fe6 100644
--- a/deps/v8/src/objects/property-descriptor-object.h
+++ b/deps/v8/src/objects/property-descriptor-object.h
@@ -5,8 +5,8 @@
 #ifndef V8_OBJECTS_PROPERTY_DESCRIPTOR_OBJECT_H_
 #define V8_OBJECTS_PROPERTY_DESCRIPTOR_OBJECT_H_
 
-#include "src/base/bit-field.h"
 #include "src/objects/struct.h"
+#include "torque-generated/bit-fields-tq.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -18,19 +18,7 @@ class PropertyDescriptorObject
     : public TorqueGeneratedPropertyDescriptorObject<PropertyDescriptorObject,
                                                      Struct> {
  public:
-#define FLAGS_BIT_FIELDS(V, _)      \
-  V(IsEnumerableBit, bool, 1, _)    \
-  V(HasEnumerableBit, bool, 1, _)   \
-  V(IsConfigurableBit, bool, 1, _)  \
-  V(HasConfigurableBit, bool, 1, _) \
-  V(IsWritableBit, bool, 1, _)      \
-  V(HasWritableBit, bool, 1, _)     \
-  V(HasValueBit, bool, 1, _)        \
-  V(HasGetBit, bool, 1, _)          \
-  V(HasSetBit, bool, 1, _)
-
-  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
-#undef FLAGS_BIT_FIELDS
+  DEFINE_TORQUE_GENERATED_PROPERTY_DESCRIPTOR_OBJECT_FLAGS()
 
   static const int kRegularAccessorPropertyBits =
       HasEnumerableBit::kMask | HasConfigurableBit::kMask | HasGetBit::kMask |
diff --git a/deps/v8/src/objects/property-descriptor-object.tq b/deps/v8/src/objects/property-descriptor-object.tq
index b71a1e8878..726769f29a 100644
--- a/deps/v8/src/objects/property-descriptor-object.tq
+++ b/deps/v8/src/objects/property-descriptor-object.tq
@@ -4,10 +4,22 @@
 
 #include 'src/objects/property-descriptor-object.h'
 
+bitfield struct PropertyDescriptorObjectFlags extends uint31 {
+  is_enumerable: bool: 1 bit;
+  has_enumerable: bool: 1 bit;
+  is_configurable: bool: 1 bit;
+  has_configurable: bool: 1 bit;
+  is_writable: bool: 1 bit;
+  has_writable: bool: 1 bit;
+  has_value: bool: 1 bit;
+  has_get: bool: 1 bit;
+  has_set: bool: 1 bit;
+}
+
 @generateCppClass
 @generatePrint
 extern class PropertyDescriptorObject extends Struct {
-  flags: Smi;
+  flags: SmiTagged<PropertyDescriptorObjectFlags>;
   value: JSAny|TheHole;
   get: JSAny|TheHole;
   set: JSAny|TheHole;
diff --git a/deps/v8/src/objects/property-descriptor.cc b/deps/v8/src/objects/property-descriptor.cc
index 325de41c2b..9c9a71849f 100644
--- a/deps/v8/src/objects/property-descriptor.cc
+++ b/deps/v8/src/objects/property-descriptor.cc
@@ -60,7 +60,6 @@ bool ToPropertyDescriptorFastPath(Isolate* isolate, Handle<JSReceiver> obj,
       Handle<DescriptorArray>(map.instance_descriptors(), isolate);
   for (InternalIndex i : map.IterateOwnDescriptors()) {
     PropertyDetails details = descs->GetDetails(i);
-    Name key = descs->GetKey(i);
     Handle<Object> value;
     if (details.location() == kField) {
       if (details.kind() == kData) {
@@ -83,6 +82,7 @@ bool ToPropertyDescriptorFastPath(Isolate* isolate, Handle<JSReceiver> obj,
         return false;
       }
     }
+    Name key = descs->GetKey(i);
     ReadOnlyRoots roots(isolate);
     if (key == roots.enumerable_string()) {
       desc->set_enumerable(value->BooleanValue(isolate));
@@ -355,7 +355,7 @@ Handle<PropertyDescriptorObject> PropertyDescriptor::ToPropertyDescriptorObject(
       PropertyDescriptorObject::HasGetBit::encode(has_get()) |
       PropertyDescriptorObject::HasSetBit::encode(has_set());
 
-  obj->set_flags(Smi::FromInt(flags));
+  obj->set_flags(flags);
 
   if (has_value()) obj->set_value(*value_);
   if (has_get()) obj->set_get(*get_);
diff --git a/deps/v8/src/objects/scope-info.cc b/deps/v8/src/objects/scope-info.cc
index f1112332ad..4dcd67905c 100644
--- a/deps/v8/src/objects/scope-info.cc
+++ b/deps/v8/src/objects/scope-info.cc
@@ -12,6 +12,7 @@
 
 #include "src/objects/module-inl.h"
 #include "src/objects/objects-inl.h"
+#include "src/roots/roots.h"
 
 namespace v8 {
 namespace internal {
@@ -60,7 +61,9 @@ bool ScopeInfo::Equals(ScopeInfo other) const {
 #endif
 
 // static
-Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
+template <typename LocalIsolate>
+Handle<ScopeInfo> ScopeInfo::Create(LocalIsolate* isolate, Zone* zone,
+                                    Scope* scope,
                                     MaybeHandle<ScopeInfo> outer_scope) {
   // Collect variables.
   int context_local_count = 0;
@@ -376,6 +379,15 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
   return scope_info_handle;
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ScopeInfo> ScopeInfo::Create<Isolate>(
+        Isolate* isolate, Zone* zone, Scope* scope,
+        MaybeHandle<ScopeInfo> outer_scope);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<ScopeInfo> ScopeInfo::Create<OffThreadIsolate>(
+        OffThreadIsolate* isolate, Zone* zone, Scope* scope,
+        MaybeHandle<ScopeInfo> outer_scope);
+
 // static
 Handle<ScopeInfo> ScopeInfo::CreateForWithScope(
     Isolate* isolate, MaybeHandle<ScopeInfo> outer_scope) {
@@ -1031,8 +1043,9 @@ std::ostream& operator<<(std::ostream& os, VariableAllocationInfo var_info) {
   return os;
 }
 
+template <typename LocalIsolate>
 Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
-    Isolate* isolate, Handle<PrimitiveHeapObject> export_name,
+    LocalIsolate* isolate, Handle<PrimitiveHeapObject> export_name,
     Handle<PrimitiveHeapObject> local_name,
     Handle<PrimitiveHeapObject> import_name, int module_request, int cell_index,
     int beg_pos, int end_pos) {
@@ -1049,16 +1062,27 @@ Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
   return result;
 }
 
+template Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
+    Isolate* isolate, Handle<PrimitiveHeapObject> export_name,
+    Handle<PrimitiveHeapObject> local_name,
+    Handle<PrimitiveHeapObject> import_name, int module_request, int cell_index,
+    int beg_pos, int end_pos);
+template Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
+    OffThreadIsolate* isolate, Handle<PrimitiveHeapObject> export_name,
+    Handle<PrimitiveHeapObject> local_name,
+    Handle<PrimitiveHeapObject> import_name, int module_request, int cell_index,
+    int beg_pos, int end_pos);
+
+template <typename LocalIsolate>
 Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
-    Isolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr) {
+    LocalIsolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr) {
   // Serialize module requests.
   int size = static_cast<int>(descr->module_requests().size());
   Handle<FixedArray> module_requests = isolate->factory()->NewFixedArray(size);
   Handle<FixedArray> module_request_positions =
       isolate->factory()->NewFixedArray(size);
   for (const auto& elem : descr->module_requests()) {
-    module_requests->set(elem.second.index,
-                         *elem.first->string().get<Factory>());
+    module_requests->set(elem.second.index, *elem.first->string());
     module_request_positions->set(elem.second.index,
                                   Smi::FromInt(elem.second.position));
   }
@@ -1113,6 +1137,10 @@ Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
   result->set(kModuleRequestPositionsIndex, *module_request_positions);
   return result;
 }
+template Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
+    Isolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr);
+template Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
+    OffThreadIsolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr);
 
 int SourceTextModuleInfo::RegularExportCount() const {
   DCHECK_EQ(regular_exports().length() % kRegularExportLength, 0);
diff --git a/deps/v8/src/objects/scope-info.h b/deps/v8/src/objects/scope-info.h
index 1eff2c411f..2e7df22562 100644
--- a/deps/v8/src/objects/scope-info.h
+++ b/deps/v8/src/objects/scope-info.h
@@ -36,8 +36,10 @@ class Zone;
 
 // This object provides quick access to scope info details for runtime
 // routines.
-class ScopeInfo : public FixedArray, public TorqueGeneratedScopeFlagsFields {
+class ScopeInfo : public FixedArray {
  public:
+  DEFINE_TORQUE_GENERATED_SCOPE_FLAGS()
+
   DECL_CAST(ScopeInfo)
   DECL_PRINTER(ScopeInfo)
 
@@ -218,7 +220,9 @@ class ScopeInfo : public FixedArray, public TorqueGeneratedScopeFlagsFields {
   bool Equals(ScopeInfo other) const;
 #endif
 
-  static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope,
+  template <typename LocalIsolate>
+  static Handle<ScopeInfo> Create(LocalIsolate* isolate, Zone* zone,
+                                  Scope* scope,
                                   MaybeHandle<ScopeInfo> outer_scope);
   static Handle<ScopeInfo> CreateForWithScope(
       Isolate* isolate, MaybeHandle<ScopeInfo> outer_scope);
diff --git a/deps/v8/src/objects/script.h b/deps/v8/src/objects/script.h
index 3a038c1c38..b9fb7ea4f9 100644
--- a/deps/v8/src/objects/script.h
+++ b/deps/v8/src/objects/script.h
@@ -7,6 +7,7 @@
 
 #include <memory>
 
+#include "src/base/export-template.h"
 #include "src/objects/fixed-array.h"
 #include "src/objects/objects.h"
 #include "src/objects/struct.h"
@@ -154,7 +155,9 @@ class Script : public Struct {
   bool ContainsAsmModule();
 
   // Init line_ends array with source code positions of line ends.
-  V8_EXPORT_PRIVATE static void InitLineEnds(Handle<Script> script);
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  static void InitLineEnds(LocalIsolate* isolate, Handle<Script> script);
 
   // Carries information about a source position.
   struct PositionInfo {
@@ -192,8 +195,9 @@ class Script : public Struct {
 
   // Look through the list of existing shared function infos to find one
   // that matches the function literal.  Return empty handle if not found.
+  template <typename LocalIsolate>
   MaybeHandle<SharedFunctionInfo> FindSharedFunctionInfo(
-      Isolate* isolate, const FunctionLiteral* fun);
+      LocalIsolate* isolate, const FunctionLiteral* fun);
 
   // Iterate over all script objects on the heap.
   class V8_EXPORT_PRIVATE Iterator {
diff --git a/deps/v8/src/objects/shared-function-info-inl.h b/deps/v8/src/objects/shared-function-info-inl.h
index 9beba6d63b..af1b685ca8 100644
--- a/deps/v8/src/objects/shared-function-info-inl.h
+++ b/deps/v8/src/objects/shared-function-info-inl.h
@@ -110,11 +110,12 @@ INT_ACCESSORS(SharedFunctionInfo, unique_id, kUniqueIdOffset)
 UINT16_ACCESSORS(SharedFunctionInfo, length, kLengthOffset)
 UINT16_ACCESSORS(SharedFunctionInfo, internal_formal_parameter_count,
                  kFormalParameterCountOffset)
-UINT16_ACCESSORS(SharedFunctionInfo, expected_nof_properties,
-                 kExpectedNofPropertiesOffset)
+UINT8_ACCESSORS(SharedFunctionInfo, expected_nof_properties,
+                kExpectedNofPropertiesOffset)
 UINT16_ACCESSORS(SharedFunctionInfo, raw_function_token_offset,
                  kFunctionTokenOffsetOffset)
 RELAXED_INT32_ACCESSORS(SharedFunctionInfo, flags, kFlagsOffset)
+UINT8_ACCESSORS(SharedFunctionInfo, flags2, kFlags2Offset)
 
 bool SharedFunctionInfo::HasSharedName() const {
   Object value = name_or_scope_info();
@@ -184,6 +185,13 @@ int SharedFunctionInfo::function_token_position() const {
   }
 }
 
+BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags2, class_scope_has_private_brand,
+                    SharedFunctionInfo::ClassScopeHasPrivateBrandBit)
+
+BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags2,
+                    has_static_private_methods_or_accessors,
+                    SharedFunctionInfo::HasStaticPrivateMethodsOrAccessorsBit)
+
 BIT_FIELD_ACCESSORS(SharedFunctionInfo, flags, syntax_kind,
                     SharedFunctionInfo::FunctionSyntaxKindBits)
 
@@ -329,7 +337,7 @@ ScopeInfo SharedFunctionInfo::scope_info() const {
   if (maybe_scope_info.IsScopeInfo()) {
     return ScopeInfo::cast(maybe_scope_info);
   }
-  return ScopeInfo::Empty(GetIsolate());
+  return GetReadOnlyRoots().empty_scope_info();
 }
 
 void SharedFunctionInfo::set_scope_info(ScopeInfo scope_info,
@@ -432,7 +440,7 @@ bool SharedFunctionInfo::IsApiFunction() const {
   return function_data().IsFunctionTemplateInfo();
 }
 
-FunctionTemplateInfo SharedFunctionInfo::get_api_func_data() {
+FunctionTemplateInfo SharedFunctionInfo::get_api_func_data() const {
   DCHECK(IsApiFunction());
   return FunctionTemplateInfo::cast(function_data());
 }
@@ -619,7 +627,15 @@ void SharedFunctionInfo::ClearPreparseData() {
   DCHECK(HasUncompiledDataWithoutPreparseData());
 }
 
-void UncompiledData::Init(
+template <typename LocalIsolate>
+void UncompiledData::Init(LocalIsolate* isolate, String inferred_name,
+                          int start_position, int end_position) {
+  set_inferred_name(inferred_name);
+  set_start_position(start_position);
+  set_end_position(end_position);
+}
+
+void UncompiledData::InitAfterBytecodeFlush(
     String inferred_name, int start_position, int end_position,
     std::function<void(HeapObject object, ObjectSlot slot, HeapObject target)>
         gc_notify_updated_slot) {
@@ -630,17 +646,14 @@ void UncompiledData::Init(
   set_end_position(end_position);
 }
 
-void UncompiledDataWithPreparseData::Init(
-    String inferred_name, int start_position, int end_position,
-    PreparseData scope_data,
-    std::function<void(HeapObject object, ObjectSlot slot, HeapObject target)>
-        gc_notify_updated_slot) {
-  this->UncompiledData::Init(inferred_name, start_position, end_position,
-                             gc_notify_updated_slot);
+template <typename LocalIsolate>
+void UncompiledDataWithPreparseData::Init(LocalIsolate* isolate,
+                                          String inferred_name,
+                                          int start_position, int end_position,
+                                          PreparseData scope_data) {
+  this->UncompiledData::Init(isolate, inferred_name, start_position,
+                             end_position);
   set_preparse_data(scope_data);
-  gc_notify_updated_slot(
-      *this, RawField(UncompiledDataWithPreparseData::kPreparseDataOffset),
-      scope_data);
 }
 
 bool SharedFunctionInfo::HasWasmExportedFunctionData() const {
diff --git a/deps/v8/src/objects/shared-function-info.h b/deps/v8/src/objects/shared-function-info.h
index 0a0ed81f3f..fd8dbb6c89 100644
--- a/deps/v8/src/objects/shared-function-info.h
+++ b/deps/v8/src/objects/shared-function-info.h
@@ -99,11 +99,14 @@ class PreparseData
 class UncompiledData
     : public TorqueGeneratedUncompiledData<UncompiledData, HeapObject> {
  public:
-  inline void Init(
+  template <typename LocalIsolate>
+  inline void Init(LocalIsolate* isolate, String inferred_name,
+                   int start_position, int end_position);
+
+  inline void InitAfterBytecodeFlush(
       String inferred_name, int start_position, int end_position,
       std::function<void(HeapObject object, ObjectSlot slot, HeapObject target)>
-          gc_notify_updated_slot =
-              [](HeapObject object, ObjectSlot slot, HeapObject target) {});
+          gc_notify_updated_slot);
 
   using BodyDescriptor =
       FixedBodyDescriptor<kStartOfStrongFieldsOffset, kEndOfStrongFieldsOffset,
@@ -135,12 +138,10 @@ class UncompiledDataWithPreparseData
  public:
   DECL_PRINTER(UncompiledDataWithPreparseData)
 
-  inline void Init(
-      String inferred_name, int start_position, int end_position,
-      PreparseData scope_data,
-      std::function<void(HeapObject object, ObjectSlot slot, HeapObject target)>
-          gc_notify_updated_slot =
-              [](HeapObject object, ObjectSlot slot, HeapObject target) {});
+  template <typename LocalIsolate>
+  inline void Init(LocalIsolate* isolate, String inferred_name,
+                   int start_position, int end_position,
+                   PreparseData scope_data);
 
   using BodyDescriptor = SubclassBodyDescriptor<
       UncompiledData::BodyDescriptor,
@@ -167,10 +168,11 @@ class InterpreterData : public Struct {
 
 // SharedFunctionInfo describes the JSFunction information that can be
 // shared by multiple instances of the function.
-class SharedFunctionInfo : public HeapObject,
-                           public TorqueGeneratedSharedFunctionInfoFlagsFields {
+class SharedFunctionInfo : public HeapObject {
  public:
   NEVER_READ_ONLY_SPACE
+  DEFINE_TORQUE_GENERATED_SHARED_FUNCTION_INFO_FLAGS()
+  DEFINE_TORQUE_GENERATED_SHARED_FUNCTION_INFO_FLAGS2()
 
   // This initializes the SharedFunctionInfo after allocation. It must
   // initialize all fields, and leave the SharedFunctionInfo in a state where
@@ -278,7 +280,7 @@ class SharedFunctionInfo : public HeapObject,
 
   // [expected_nof_properties]: Expected number of properties for the
   // function. The value is only reliable when the function has been compiled.
-  DECL_UINT16_ACCESSORS(expected_nof_properties)
+  DECL_UINT8_ACCESSORS(expected_nof_properties)
 
   // [function_literal_id] - uniquely identifies the FunctionLiteral this
   // SharedFunctionInfo represents within its script, or -1 if this
@@ -308,7 +310,7 @@ class SharedFunctionInfo : public HeapObject,
 
   inline bool IsApiFunction() const;
   inline bool is_class_constructor() const;
-  inline FunctionTemplateInfo get_api_func_data();
+  inline FunctionTemplateInfo get_api_func_data() const;
   inline void set_api_func_data(FunctionTemplateInfo data);
   inline bool HasBytecodeArray() const;
   inline BytecodeArray GetBytecodeArray() const;
@@ -401,6 +403,12 @@ class SharedFunctionInfo : public HeapObject,
 
   // [flags] Bit field containing various flags about the function.
   DECL_INT32_ACCESSORS(flags)
+  DECL_UINT8_ACCESSORS(flags2)
+
+  // True if the outer class scope contains a private brand for
+  // private instance methdos.
+  DECL_BOOLEAN_ACCESSORS(class_scope_has_private_brand)
+  DECL_BOOLEAN_ACCESSORS(has_static_private_methods_or_accessors)
 
   // Is this function a top-level function (scripts, evals).
   DECL_BOOLEAN_ACCESSORS(is_toplevel)
@@ -553,7 +561,8 @@ class SharedFunctionInfo : public HeapObject,
   inline bool has_simple_parameters();
 
   // Initialize a SharedFunctionInfo from a parsed function literal.
-  static void InitFromFunctionLiteral(Isolate* isolate,
+  template <typename LocalIsolate>
+  static void InitFromFunctionLiteral(LocalIsolate* isolate,
                                       Handle<SharedFunctionInfo> shared_info,
                                       FunctionLiteral* lit, bool is_toplevel);
 
@@ -587,6 +596,7 @@ class SharedFunctionInfo : public HeapObject,
   // Dispatched behavior.
   DECL_PRINTER(SharedFunctionInfo)
   DECL_VERIFIER(SharedFunctionInfo)
+  void SharedFunctionInfoVerify(OffThreadIsolate* isolate);
 #ifdef OBJECT_PRINT
   void PrintSourceCode(std::ostream& os);
 #endif
@@ -611,8 +621,6 @@ class SharedFunctionInfo : public HeapObject,
   DECL_CAST(SharedFunctionInfo)
 
   // Constants.
-  static const uint16_t kDontAdaptArgumentsSentinel = static_cast<uint16_t>(-1);
-
   static const int kMaximumFunctionTokenOffset = kMaxUInt16 - 1;
   static const uint16_t kFunctionTokenOutOfRange = static_cast<uint16_t>(-1);
   STATIC_ASSERT(kMaximumFunctionTokenOffset + 1 == kFunctionTokenOutOfRange);
@@ -638,6 +646,8 @@ class SharedFunctionInfo : public HeapObject,
   inline bool needs_home_object() const;
 
  private:
+  void SharedFunctionInfoVerify(ReadOnlyRoots roots);
+
   // [name_or_scope_info]: Function name string, kNoSharedNameSentinel or
   // ScopeInfo.
   DECL_ACCESSORS(name_or_scope_info, Object)
@@ -660,7 +670,8 @@ class SharedFunctionInfo : public HeapObject,
 
   inline uint16_t get_property_estimate_from_literal(FunctionLiteral* literal);
 
-  friend class Factory;
+  template <typename Impl>
+  friend class FactoryBase;
   friend class V8HeapExplorer;
   FRIEND_TEST(PreParserTest, LazyFunctionLength);
 
diff --git a/deps/v8/src/objects/shared-function-info.tq b/deps/v8/src/objects/shared-function-info.tq
index 2eda70da5d..f37cc250bc 100644
--- a/deps/v8/src/objects/shared-function-info.tq
+++ b/deps/v8/src/objects/shared-function-info.tq
@@ -14,10 +14,9 @@ extern class InterpreterData extends Struct {
   interpreter_trampoline: Code;
 }
 
-type FunctionKind extends uint8 constexpr 'v8::internal::FunctionKind';
-type FunctionSyntaxKind extends uint8
-constexpr 'v8::internal::FunctionSyntaxKind';
-type BailoutReason extends uint8 constexpr 'v8::internal::BailoutReason';
+type FunctionKind extends uint8 constexpr 'FunctionKind';
+type FunctionSyntaxKind extends uint8 constexpr 'FunctionSyntaxKind';
+type BailoutReason extends uint8 constexpr 'BailoutReason';
 
 bitfield struct SharedFunctionInfoFlags extends uint32 {
   // Have FunctionKind first to make it cheaper to access.
@@ -42,6 +41,11 @@ bitfield struct SharedFunctionInfoFlags extends uint32 {
   private_name_lookup_skips_outer_class: bool: 1 bit;
 }
 
+bitfield struct SharedFunctionInfoFlags2 extends uint8 {
+  class_scope_has_private_brand: bool: 1 bit;
+  has_static_private_methods_or_accessors: bool: 1 bit;
+}
+
 extern class SharedFunctionInfo extends HeapObject {
   weak function_data: Object;
   name_or_scope_info: String|NoSharedNameSentinel|ScopeInfo;
@@ -49,9 +53,9 @@ extern class SharedFunctionInfo extends HeapObject {
   script_or_debug_info: Script|DebugInfo|Undefined;
   length: int16;
   formal_parameter_count: uint16;
-  // Currently set to uint16, can be set to uint8 to save space.
-  expected_nof_properties: uint16;
   function_token_offset: int16;
+  expected_nof_properties: uint8;
+  flags2: SharedFunctionInfoFlags2;
   flags: SharedFunctionInfoFlags;
   function_literal_id: int32;
   @if(V8_SFI_HAS_UNIQUE_ID) unique_id: int32;
diff --git a/deps/v8/src/objects/slots-inl.h b/deps/v8/src/objects/slots-inl.h
index 7e692b7948..4912831c09 100644
--- a/deps/v8/src/objects/slots-inl.h
+++ b/deps/v8/src/objects/slots-inl.h
@@ -49,6 +49,12 @@ void FullObjectSlot::Release_Store(Object value) const {
   base::AsAtomicPointer::Release_Store(location(), value.ptr());
 }
 
+Object FullObjectSlot::Relaxed_CompareAndSwap(Object old, Object target) const {
+  Address result = base::AsAtomicPointer::Relaxed_CompareAndSwap(
+      location(), old.ptr(), target.ptr());
+  return Object(result);
+}
+
 Object FullObjectSlot::Release_CompareAndSwap(Object old, Object target) const {
   Address result = base::AsAtomicPointer::Release_CompareAndSwap(
       location(), old.ptr(), target.ptr());
diff --git a/deps/v8/src/objects/slots.h b/deps/v8/src/objects/slots.h
index 85f6525399..875ed7f82a 100644
--- a/deps/v8/src/objects/slots.h
+++ b/deps/v8/src/objects/slots.h
@@ -116,6 +116,7 @@ class FullObjectSlot : public SlotBase<FullObjectSlot, Address> {
   inline Object Relaxed_Load() const;
   inline void Relaxed_Store(Object value) const;
   inline void Release_Store(Object value) const;
+  inline Object Relaxed_CompareAndSwap(Object old, Object target) const;
   inline Object Release_CompareAndSwap(Object old, Object target) const;
 };
 
diff --git a/deps/v8/src/objects/source-text-module.cc b/deps/v8/src/objects/source-text-module.cc
index 6ffdd06f45..f54df2b7ca 100644
--- a/deps/v8/src/objects/source-text-module.cc
+++ b/deps/v8/src/objects/source-text-module.cc
@@ -369,9 +369,14 @@ bool SourceTextModule::RunInitializationCode(Isolate* isolate,
   Handle<JSFunction> function(JSFunction::cast(module->code()), isolate);
   DCHECK_EQ(MODULE_SCOPE, function->shared().scope_info().scope_type());
   Handle<Object> receiver = isolate->factory()->undefined_value();
-  Handle<Object> argv[] = {module};
+
+  Handle<ScopeInfo> scope_info(function->shared().scope_info(), isolate);
+  Handle<Context> context = isolate->factory()->NewModuleContext(
+      module, isolate->native_context(), scope_info);
+  function->set_context(*context);
+
   MaybeHandle<Object> maybe_generator =
-      Execution::Call(isolate, function, receiver, arraysize(argv), argv);
+      Execution::Call(isolate, function, receiver, 0, {});
   Handle<Object> generator;
   if (!maybe_generator.ToHandle(&generator)) {
     DCHECK(isolate->has_pending_exception());
@@ -1054,7 +1059,7 @@ MaybeHandle<Object> SourceTextModule::InnerModuleEvaluation(
         module->IncrementPendingAsyncDependencies();
 
         //      2. Append module to requiredModule.[[AsyncParentModules]].
-        required_module->AddAsyncParentModule(isolate, module);
+        AddAsyncParentModule(isolate, required_module, module);
       }
     } else {
       RETURN_ON_EXCEPTION(isolate, Module::Evaluate(isolate, requested_module),
diff --git a/deps/v8/src/objects/source-text-module.h b/deps/v8/src/objects/source-text-module.h
index f1387635d0..57c84d833d 100644
--- a/deps/v8/src/objects/source-text-module.h
+++ b/deps/v8/src/objects/source-text-module.h
@@ -69,8 +69,9 @@ class SourceTextModule
 
   // Appends a tuple of module and generator to the async parent modules
   // ArrayList.
-  inline void AddAsyncParentModule(Isolate* isolate,
-                                   Handle<SourceTextModule> module);
+  inline static void AddAsyncParentModule(Isolate* isolate,
+                                          Handle<SourceTextModule> module,
+                                          Handle<SourceTextModule> parent);
 
   // Returns a SourceTextModule, the
   // ith parent in depth first traversal order of a given async child.
@@ -84,13 +85,6 @@ class SourceTextModule
   inline void IncrementPendingAsyncDependencies();
   inline void DecrementPendingAsyncDependencies();
 
-  // TODO(neis): Don't store those in the module object?
-  DECL_INT_ACCESSORS(dfs_index)
-  DECL_INT_ACCESSORS(dfs_ancestor_index)
-
-  // Storage for boolean flags.
-  DECL_INT_ACCESSORS(flags)
-
   // Bits for flags.
   static const int kAsyncBit = 0;
   static const int kAsyncEvaluatingBit = 1;
@@ -107,9 +101,6 @@ class SourceTextModule
   // for cycle roots.
   DECL_ACCESSORS(top_level_capability, HeapObject)
 
-  // The number of currently evaluating async dependencies of this module.
-  DECL_INT_ACCESSORS(pending_async_dependencies)
-
   // The parent modules of a given async dependency, use async_parent_modules()
   // to retrieve the ArrayList representation.
   DECL_ACCESSORS(async_parent_modules, ArrayList)
@@ -196,7 +187,8 @@ class SourceTextModuleInfo : public FixedArray {
  public:
   DECL_CAST(SourceTextModuleInfo)
 
-  static Handle<SourceTextModuleInfo> New(Isolate* isolate, Zone* zone,
+  template <typename LocalIsolate>
+  static Handle<SourceTextModuleInfo> New(LocalIsolate* isolate, Zone* zone,
                                           SourceTextModuleDescriptor* descr);
 
   inline FixedArray module_requests() const;
@@ -217,7 +209,8 @@ class SourceTextModuleInfo : public FixedArray {
 #endif
 
  private:
-  friend class Factory;
+  template <typename Impl>
+  friend class FactoryBase;
   friend class SourceTextModuleDescriptor;
   enum {
     kModuleRequestsIndex,
@@ -245,13 +238,9 @@ class SourceTextModuleInfoEntry
   DECL_PRINTER(SourceTextModuleInfoEntry)
   DECL_VERIFIER(SourceTextModuleInfoEntry)
 
-  DECL_INT_ACCESSORS(module_request)
-  DECL_INT_ACCESSORS(cell_index)
-  DECL_INT_ACCESSORS(beg_pos)
-  DECL_INT_ACCESSORS(end_pos)
-
+  template <typename LocalIsolate>
   static Handle<SourceTextModuleInfoEntry> New(
-      Isolate* isolate, Handle<PrimitiveHeapObject> export_name,
+      LocalIsolate* isolate, Handle<PrimitiveHeapObject> export_name,
       Handle<PrimitiveHeapObject> local_name,
       Handle<PrimitiveHeapObject> import_name, int module_request,
       int cell_index, int beg_pos, int end_pos);
diff --git a/deps/v8/src/objects/source-text-module.tq b/deps/v8/src/objects/source-text-module.tq
index 0f747976bb..fda0138695 100644
--- a/deps/v8/src/objects/source-text-module.tq
+++ b/deps/v8/src/objects/source-text-module.tq
@@ -28,11 +28,17 @@ extern class SourceTextModule extends Module {
   // Lazily initialized on first access. It's the hole before first access and
   // a JSObject afterwards.
   import_meta: TheHole|JSObject;
+
   async_parent_modules: ArrayList;
   top_level_capability: JSPromise|Undefined;
+
+  // TODO(neis): Don't store those in the module object?
   dfs_index: Smi;
   dfs_ancestor_index: Smi;
+
+  // The number of currently evaluating async dependencies of this module.
   pending_async_dependencies: Smi;
+
   flags: Smi;
 }
 
diff --git a/deps/v8/src/objects/stack-frame-info-inl.h b/deps/v8/src/objects/stack-frame-info-inl.h
index ee3b83c12f..36236f576b 100644
--- a/deps/v8/src/objects/stack-frame-info-inl.h
+++ b/deps/v8/src/objects/stack-frame-info-inl.h
@@ -53,9 +53,6 @@ BOOL_ACCESSORS(StackFrameInfo, flag, is_promise_all, kIsPromiseAllBit)
 TQ_OBJECT_CONSTRUCTORS_IMPL(StackTraceFrame)
 NEVER_READ_ONLY_SPACE_IMPL(StackTraceFrame)
 
-TQ_SMI_ACCESSORS(StackTraceFrame, frame_index)
-TQ_SMI_ACCESSORS(StackTraceFrame, id)
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/stack-frame-info.cc b/deps/v8/src/objects/stack-frame-info.cc
index ac2913ebed..c15ad1031c 100644
--- a/deps/v8/src/objects/stack-frame-info.cc
+++ b/deps/v8/src/objects/stack-frame-info.cc
@@ -71,8 +71,23 @@ Handle<Object> StackTraceFrame::GetFileName(Handle<StackTraceFrame> frame) {
 // static
 Handle<Object> StackTraceFrame::GetScriptNameOrSourceUrl(
     Handle<StackTraceFrame> frame) {
-  auto name = GetFrameInfo(frame)->script_name_or_source_url();
-  return handle(name, frame->GetIsolate());
+  Isolate* isolate = frame->GetIsolate();
+  // TODO(caseq, szuend): the logic below is a workaround for crbug.com/1057211.
+  // We should probably have a dedicated API for the scenario described in the
+  // bug above and make getters of this class behave consistently.
+  // See https://bit.ly/2wkbuIy for further discussion.
+  // Use FrameInfo if it's already there, but avoid initializing it for just
+  // the script name, as it is much more expensive than just getting this
+  // directly.
+  if (!frame->frame_info().IsUndefined()) {
+    auto name = GetFrameInfo(frame)->script_name_or_source_url();
+    return handle(name, isolate);
+  }
+  FrameArrayIterator it(isolate,
+                        handle(FrameArray::cast(frame->frame_array()), isolate),
+                        frame->frame_index());
+  DCHECK(it.HasFrame());
+  return it.Frame()->GetScriptNameOrSourceUrl();
 }
 
 // static
@@ -368,6 +383,16 @@ void SerializeAsmJsWasmStackFrame(Isolate* isolate,
   return;
 }
 
+bool IsAnonymousWasmScript(Isolate* isolate, Handle<StackTraceFrame> frame,
+                           Handle<Object> url) {
+  DCHECK(url->IsString());
+  Handle<String> anonymous_prefix =
+      isolate->factory()->InternalizeString(StaticCharVector("wasm://wasm/"));
+  return (StackTraceFrame::IsWasm(frame) &&
+          StringIndexOf(isolate, Handle<String>::cast(url), anonymous_prefix) >=
+              0);
+}
+
 void SerializeWasmStackFrame(Isolate* isolate, Handle<StackTraceFrame> frame,
                              IncrementalStringBuilder* builder) {
   Handle<Object> module_name = StackTraceFrame::GetWasmModuleName(frame);
@@ -386,8 +411,15 @@ void SerializeWasmStackFrame(Isolate* isolate, Handle<StackTraceFrame> frame,
     builder->AppendCString(" (");
   }
 
-  const int wasm_func_index = StackTraceFrame::GetWasmFunctionIndex(frame);
+  Handle<Object> url = StackTraceFrame::GetScriptNameOrSourceUrl(frame);
+  if (IsNonEmptyString(url) && !IsAnonymousWasmScript(isolate, frame, url)) {
+    builder->AppendString(Handle<String>::cast(url));
+  } else {
+    builder->AppendCString("<anonymous>");
+  }
+  builder->AppendCString(":");
 
+  const int wasm_func_index = StackTraceFrame::GetWasmFunctionIndex(frame);
   builder->AppendCString("wasm-function[");
   builder->AppendInt(wasm_func_index);
   builder->AppendCString("]:");
diff --git a/deps/v8/src/objects/stack-frame-info.h b/deps/v8/src/objects/stack-frame-info.h
index 2ede430f11..83a24c047a 100644
--- a/deps/v8/src/objects/stack-frame-info.h
+++ b/deps/v8/src/objects/stack-frame-info.h
@@ -76,8 +76,6 @@ class StackTraceFrame
     : public TorqueGeneratedStackTraceFrame<StackTraceFrame, Struct> {
  public:
   NEVER_READ_ONLY_SPACE
-  DECL_INT_ACCESSORS(frame_index)
-  DECL_INT_ACCESSORS(id)
 
   // Dispatched behavior.
   DECL_PRINTER(StackTraceFrame)
@@ -128,6 +126,7 @@ Handle<FrameArray> GetFrameArrayFromStackTrace(Isolate* isolate,
 class IncrementalStringBuilder;
 void SerializeStackTraceFrame(Isolate* isolate, Handle<StackTraceFrame> frame,
                               IncrementalStringBuilder* builder);
+V8_EXPORT_PRIVATE
 MaybeHandle<String> SerializeStackTraceFrame(Isolate* isolate,
                                              Handle<StackTraceFrame> frame);
 
diff --git a/deps/v8/src/objects/string-inl.h b/deps/v8/src/objects/string-inl.h
index 93453eee21..5dd460a959 100644
--- a/deps/v8/src/objects/string-inl.h
+++ b/deps/v8/src/objects/string-inl.h
@@ -397,6 +397,13 @@ Handle<String> String::Flatten(Isolate* isolate, Handle<String> string,
   return string;
 }
 
+Handle<String> String::Flatten(OffThreadIsolate* isolate, Handle<String> string,
+                               AllocationType allocation) {
+  // We should never pass non-flat strings to String::Flatten when off-thread.
+  DCHECK(string->IsFlat());
+  return string;
+}
+
 uint16_t String::Get(int index) {
   DCHECK(index >= 0 && index < length());
 
@@ -575,8 +582,6 @@ void SlicedString::set_parent(String parent, WriteBarrierMode mode) {
   TorqueGeneratedSlicedString<SlicedString, Super>::set_parent(parent, mode);
 }
 
-TQ_SMI_ACCESSORS(SlicedString, offset)
-
 Object ConsString::unchecked_first() {
   return TaggedField<Object, kFirstOffset>::load(*this);
 }
@@ -773,15 +778,11 @@ void StringCharacterStream::VisitTwoByteString(const uint16_t* chars,
 bool String::AsArrayIndex(uint32_t* index) {
   DisallowHeapAllocation no_gc;
   uint32_t field = hash_field();
-  // The {IsHashFieldComputed} check is not functionally necessary as the
-  // subsequent mask includes it; it's here to make the logic more obvious,
-  // and the compile will fold it away so it doesn't hurt performance.
-  if (IsHashFieldComputed(field) &&
-      (field & kDoesNotContainCachedArrayIndexMask) == 0) {
+  if (ContainsCachedArrayIndex(field)) {
     *index = ArrayIndexValueBits::decode(field);
     return true;
   }
-  if (IsHashFieldComputed(field) && (field & kIsNotArrayIndexMask)) {
+  if (IsHashFieldComputed(field) && (field & kIsNotIntegerIndexMask)) {
     return false;
   }
   return SlowAsArrayIndex(index);
@@ -789,11 +790,7 @@ bool String::AsArrayIndex(uint32_t* index) {
 
 bool String::AsIntegerIndex(size_t* index) {
   uint32_t field = hash_field();
-  // The {IsHashFieldComputed} check is not functionally necessary as the
-  // subsequent mask includes it; it's here to make the logic more obvious,
-  // and the compile will fold it away so it doesn't hurt performance.
-  if (IsHashFieldComputed(field) &&
-      (field & kDoesNotContainCachedArrayIndexMask) == 0) {
+  if (ContainsCachedArrayIndex(field)) {
     *index = ArrayIndexValueBits::decode(field);
     return true;
   }
diff --git a/deps/v8/src/objects/string-table-inl.h b/deps/v8/src/objects/string-table-inl.h
index 1b7b7d140c..c0bcd2083b 100644
--- a/deps/v8/src/objects/string-table-inl.h
+++ b/deps/v8/src/objects/string-table-inl.h
@@ -32,7 +32,7 @@ bool StringSetShape::IsMatch(String key, Object value) {
   return key.Equals(String::cast(value));
 }
 
-uint32_t StringSetShape::Hash(Isolate* isolate, String key) {
+uint32_t StringSetShape::Hash(ReadOnlyRoots roots, String key) {
   return key.Hash();
 }
 
@@ -59,7 +59,7 @@ uint32_t StringTableKey::hash() const {
 }
 
 // static
-uint32_t StringTableShape::Hash(Isolate* isolate, Key key) {
+uint32_t StringTableShape::Hash(ReadOnlyRoots roots, Key key) {
   return key->hash();
 }
 
@@ -72,8 +72,8 @@ uint32_t StringTableShape::HashForObject(ReadOnlyRoots roots, Object object) {
   return String::cast(object).Hash();
 }
 
-RootIndex StringTableShape::GetMapRootIndex() {
-  return RootIndex::kStringTableMap;
+Handle<Map> StringTableShape::GetMap(ReadOnlyRoots roots) {
+  return roots.string_table_map_handle();
 }
 
 }  // namespace internal
diff --git a/deps/v8/src/objects/string-table.h b/deps/v8/src/objects/string-table.h
index e6619db4ba..54af9a4452 100644
--- a/deps/v8/src/objects/string-table.h
+++ b/deps/v8/src/objects/string-table.h
@@ -41,13 +41,13 @@ class V8_EXPORT_PRIVATE StringTableShape : public BaseShape<StringTableKey*> {
  public:
   static inline bool IsMatch(Key key, Object value);
 
-  static inline uint32_t Hash(Isolate* isolate, Key key);
+  static inline uint32_t Hash(ReadOnlyRoots roots, Key key);
 
   static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
 
   static inline Handle<Object> AsHandle(Isolate* isolate, Key key);
 
-  static inline RootIndex GetMapRootIndex();
+  static inline Handle<Map> GetMap(ReadOnlyRoots roots);
 
   static const int kPrefixSize = 0;
   static const int kEntrySize = 1;
@@ -55,6 +55,8 @@ class V8_EXPORT_PRIVATE StringTableShape : public BaseShape<StringTableKey*> {
 
 class SeqOneByteString;
 
+EXTERN_DECLARE_HASH_TABLE(StringTable, StringTableShape)
+
 // StringTable.
 //
 // No special elements in the prefix and the element size is 1
@@ -98,13 +100,15 @@ class V8_EXPORT_PRIVATE StringTable
 class StringSetShape : public BaseShape<String> {
  public:
   static inline bool IsMatch(String key, Object value);
-  static inline uint32_t Hash(Isolate* isolate, String key);
+  static inline uint32_t Hash(ReadOnlyRoots roots, String key);
   static inline uint32_t HashForObject(ReadOnlyRoots roots, Object object);
 
   static const int kPrefixSize = 0;
   static const int kEntrySize = 1;
 };
 
+EXTERN_DECLARE_HASH_TABLE(StringSet, StringSetShape)
+
 class StringSet : public HashTable<StringSet, StringSetShape> {
  public:
   V8_EXPORT_PRIVATE static Handle<StringSet> New(Isolate* isolate);
diff --git a/deps/v8/src/objects/string.cc b/deps/v8/src/objects/string.cc
index cf91a10bd0..8c96900bbe 100644
--- a/deps/v8/src/objects/string.cc
+++ b/deps/v8/src/objects/string.cc
@@ -4,6 +4,7 @@
 
 #include "src/objects/string.h"
 
+#include "src/common/globals.h"
 #include "src/handles/handles-inl.h"
 #include "src/heap/heap-inl.h"  // For LooksValid implementation.
 #include "src/heap/read-only-heap.h"
@@ -688,7 +689,7 @@ void String::WriteToFlat(String src, sinkchar* sink, int f, int t) {
 }
 
 template <typename SourceChar>
-static void CalculateLineEndsImpl(Isolate* isolate, std::vector<int>* line_ends,
+static void CalculateLineEndsImpl(std::vector<int>* line_ends,
                                   Vector<const SourceChar> src,
                                   bool include_ending_line) {
   const int src_len = src.length();
@@ -708,7 +709,8 @@ static void CalculateLineEndsImpl(Isolate* isolate, std::vector<int>* line_ends,
   }
 }
 
-Handle<FixedArray> String::CalculateLineEnds(Isolate* isolate,
+template <typename LocalIsolate>
+Handle<FixedArray> String::CalculateLineEnds(LocalIsolate* isolate,
                                              Handle<String> src,
                                              bool include_ending_line) {
   src = Flatten(isolate, src);
@@ -723,21 +725,29 @@ Handle<FixedArray> String::CalculateLineEnds(Isolate* isolate,
     String::FlatContent content = src->GetFlatContent(no_allocation);
     DCHECK(content.IsFlat());
     if (content.IsOneByte()) {
-      CalculateLineEndsImpl(isolate, &line_ends, content.ToOneByteVector(),
+      CalculateLineEndsImpl(&line_ends, content.ToOneByteVector(),
                             include_ending_line);
     } else {
-      CalculateLineEndsImpl(isolate, &line_ends, content.ToUC16Vector(),
+      CalculateLineEndsImpl(&line_ends, content.ToUC16Vector(),
                             include_ending_line);
     }
   }
   int line_count = static_cast<int>(line_ends.size());
-  Handle<FixedArray> array = isolate->factory()->NewFixedArray(line_count);
+  Handle<FixedArray> array =
+      isolate->factory()->NewFixedArray(line_count, AllocationType::kOld);
   for (int i = 0; i < line_count; i++) {
     array->set(i, Smi::FromInt(line_ends[i]));
   }
   return array;
 }
 
+template Handle<FixedArray> String::CalculateLineEnds(Isolate* isolate,
+                                                      Handle<String> src,
+                                                      bool include_ending_line);
+template Handle<FixedArray> String::CalculateLineEnds(OffThreadIsolate* isolate,
+                                                      Handle<String> src,
+                                                      bool include_ending_line);
+
 bool String::SlowEquals(String other) {
   DisallowHeapAllocation no_gc;
   // Fast check: negative check with lengths.
@@ -1371,7 +1381,7 @@ bool String::SlowAsArrayIndex(uint32_t* index) {
   if (length <= kMaxCachedArrayIndexLength) {
     Hash();  // Force computation of hash code.
     uint32_t field = hash_field();
-    if ((field & kIsNotArrayIndexMask) != 0) return false;
+    if ((field & kIsNotIntegerIndexMask) != 0) return false;
     *index = ArrayIndexValueBits::decode(field);
     return true;
   }
@@ -1386,12 +1396,7 @@ bool String::SlowAsIntegerIndex(size_t* index) {
   if (length <= kMaxCachedArrayIndexLength) {
     Hash();  // Force computation of hash code.
     uint32_t field = hash_field();
-    if ((field & kIsNotArrayIndexMask) != 0) {
-      // If it was short but it's not an array index, then it can't be an
-      // integer index either.
-      DCHECK_NE(0, field & kIsNotIntegerIndexMask);
-      return false;
-    }
+    if ((field & kIsNotIntegerIndexMask) != 0) return false;
     *index = ArrayIndexValueBits::decode(field);
     return true;
   }
@@ -1652,6 +1657,37 @@ String ConsStringIterator::NextLeaf(bool* blew_stack) {
   UNREACHABLE();
 }
 
+const byte* String::AddressOfCharacterAt(int start_index,
+                                         const DisallowHeapAllocation& no_gc) {
+  DCHECK(IsFlat());
+  String subject = *this;
+  if (subject.IsConsString()) {
+    subject = ConsString::cast(subject).first();
+  } else if (subject.IsSlicedString()) {
+    start_index += SlicedString::cast(subject).offset();
+    subject = SlicedString::cast(subject).parent();
+  }
+  if (subject.IsThinString()) {
+    subject = ThinString::cast(subject).actual();
+  }
+  CHECK_LE(0, start_index);
+  CHECK_LE(start_index, subject.length());
+  if (subject.IsSeqOneByteString()) {
+    return reinterpret_cast<const byte*>(
+        SeqOneByteString::cast(subject).GetChars(no_gc) + start_index);
+  } else if (subject.IsSeqTwoByteString()) {
+    return reinterpret_cast<const byte*>(
+        SeqTwoByteString::cast(subject).GetChars(no_gc) + start_index);
+  } else if (subject.IsExternalOneByteString()) {
+    return reinterpret_cast<const byte*>(
+        ExternalOneByteString::cast(subject).GetChars() + start_index);
+  } else {
+    DCHECK(subject.IsExternalTwoByteString());
+    return reinterpret_cast<const byte*>(
+        ExternalTwoByteString::cast(subject).GetChars() + start_index);
+  }
+}
+
 template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE) void String::WriteToFlat(
     String source, uint16_t* sink, int from, int to);
 
diff --git a/deps/v8/src/objects/string.h b/deps/v8/src/objects/string.h
index 941d5f3c7c..616a4b967b 100644
--- a/deps/v8/src/objects/string.h
+++ b/deps/v8/src/objects/string.h
@@ -161,6 +161,11 @@ class String : public TorqueGeneratedString<String, Name> {
   template <typename Char>
   inline const Char* GetChars(const DisallowHeapAllocation& no_gc);
 
+  // Returns the address of the character at an offset into this string.
+  // Requires: this->IsFlat()
+  const byte* AddressOfCharacterAt(int start_index,
+                                   const DisallowHeapAllocation& no_gc);
+
   // Get and set the length of the string using acquire loads and release
   // stores.
   DECL_SYNCHRONIZED_INT_ACCESSORS(length)
@@ -203,6 +208,9 @@ class String : public TorqueGeneratedString<String, Name> {
   static inline Handle<String> Flatten(
       Isolate* isolate, Handle<String> string,
       AllocationType allocation = AllocationType::kYoung);
+  static inline Handle<String> Flatten(
+      OffThreadIsolate* isolate, Handle<String> string,
+      AllocationType allocation = AllocationType::kYoung);
 
   // Tries to return the content of a flat string as a structure holding either
   // a flat vector of char or of uc16.
@@ -454,7 +462,8 @@ class String : public TorqueGeneratedString<String, Name> {
   static inline ConsString VisitFlat(Visitor* visitor, String string,
                                      int offset = 0);
 
-  static Handle<FixedArray> CalculateLineEnds(Isolate* isolate,
+  template <typename LocalIsolate>
+  static Handle<FixedArray> CalculateLineEnds(LocalIsolate* isolate,
                                               Handle<String> string,
                                               bool include_ending_line);
 
@@ -673,7 +682,6 @@ class SlicedString : public TorqueGeneratedSlicedString<SlicedString, String> {
  public:
   inline void set_parent(String parent,
                          WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
-  DECL_INT_ACCESSORS(offset)
   // Dispatched behavior.
   V8_EXPORT_PRIVATE uint16_t Get(int index);
 
diff --git a/deps/v8/src/objects/string.tq b/deps/v8/src/objects/string.tq
index b7d297d9a1..b8d9714b36 100644
--- a/deps/v8/src/objects/string.tq
+++ b/deps/v8/src/objects/string.tq
@@ -6,7 +6,7 @@
 @generateCppClass
 @reserveBitsInInstanceType(6)
 extern class String extends Name {
-  length: int32;
+  const length: int32;
 }
 
 @generateCppClass
diff --git a/deps/v8/src/objects/struct-inl.h b/deps/v8/src/objects/struct-inl.h
index a7bbc77f55..fbbdd3038b 100644
--- a/deps/v8/src/objects/struct-inl.h
+++ b/deps/v8/src/objects/struct-inl.h
@@ -34,9 +34,6 @@ void Struct::InitializeBody(int object_size) {
   }
 }
 
-TQ_SMI_ACCESSORS(ClassPositions, start)
-TQ_SMI_ACCESSORS(ClassPositions, end)
-
 Object AccessorPair::get(AccessorComponent component) {
   return component == ACCESSOR_GETTER ? getter() : setter();
 }
diff --git a/deps/v8/src/objects/struct.h b/deps/v8/src/objects/struct.h
index 8ee84a59cc..e28785ce6e 100644
--- a/deps/v8/src/objects/struct.h
+++ b/deps/v8/src/objects/struct.h
@@ -68,9 +68,6 @@ class AccessorPair : public TorqueGeneratedAccessorPair<AccessorPair, Struct> {
 class ClassPositions
     : public TorqueGeneratedClassPositions<ClassPositions, Struct> {
  public:
-  DECL_INT_ACCESSORS(start)
-  DECL_INT_ACCESSORS(end)
-
   // Dispatched behavior.
   DECL_PRINTER(ClassPositions)
   void BriefPrintDetails(std::ostream& os);
diff --git a/deps/v8/src/objects/tagged-index.h b/deps/v8/src/objects/tagged-index.h
new file mode 100644
index 0000000000..c7d6a85a0d
--- /dev/null
+++ b/deps/v8/src/objects/tagged-index.h
@@ -0,0 +1,84 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_OBJECTS_TAGGED_INDEX_H_
+#define V8_OBJECTS_TAGGED_INDEX_H_
+
+#include "src/common/globals.h"
+#include "src/objects/heap-object.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+// TaggedIndex represents integer values that can be stored in 31 bits.
+// The on 32-bit architectures ptr_ value has the following format:
+//   [31 bit signed int] 0
+// The on 64-bit architectures ptr_ value has the following format:
+//   [32 bits of sign-extended lower part][31 bit signed int] 0
+// Thus, on 32-bit architectures TaggedIndex is exactly the same as Smi but
+// on 64-bit architectures TaggedIndex differs from Smi in the following
+// aspects:
+// 1) TaggedIndex payload is always 31 bit independent of the Smi payload size
+// 2) TaggedIndex is always properly sign-extended independent of whether
+//    pointer compression is enabled or not. In the former case, upper 32 bits
+//    of a Smi value may contain 0 or sign or isolate root value.
+//
+// Given the above constraints TaggedIndex has the following properties:
+// 1) it still looks like a Smi from GC point of view and therefore it's safe
+//   to pass TaggedIndex values to runtime functions or builtins on the stack
+// 2) since the TaggedIndex values are already properly sign-extended it's
+//   safe to use them as indices in offset-computation functions.
+class TaggedIndex : public Object {
+ public:
+  // This replaces the OBJECT_CONSTRUCTORS macro, because TaggedIndex are
+  // special in that we want them to be constexprs.
+  constexpr TaggedIndex() : Object() {}
+  explicit constexpr TaggedIndex(Address ptr) : Object(ptr) {
+#if V8_HAS_CXX14_CONSTEXPR
+    DCHECK(HAS_SMI_TAG(ptr));
+#endif
+  }
+
+  // Returns the integer value.
+  inline intptr_t value() const {
+    // Truncate and shift down (requires >> to be sign extending).
+    return static_cast<intptr_t>(ptr()) >> kSmiTagSize;
+  }
+
+  // Convert a value to a TaggedIndex object.
+  static inline TaggedIndex FromIntptr(intptr_t value) {
+#if V8_HAS_CXX14_CONSTEXPR
+    DCHECK(TaggedIndex::IsValid(value));
+#endif
+    return TaggedIndex((static_cast<Address>(value) << kSmiTagSize) | kSmiTag);
+  }
+
+  // Returns whether value can be represented in a TaggedIndex.
+  static inline bool constexpr IsValid(intptr_t value) {
+    return kMinValue <= value && value <= kMaxValue;
+  }
+
+  DECL_CAST(TaggedIndex)
+
+  // Dispatched behavior.
+  DECL_VERIFIER(TaggedIndex)
+
+  STATIC_ASSERT(kSmiTagSize == 1);
+  static constexpr int kTaggedValueSize = 31;
+  static constexpr intptr_t kMinValue =
+      static_cast<intptr_t>(kUintptrAllBitsSet << (kTaggedValueSize - 1));
+  static constexpr intptr_t kMaxValue = -(kMinValue + 1);
+};
+
+CAST_ACCESSOR(TaggedIndex)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_TAGGED_INDEX_H_
diff --git a/deps/v8/src/objects/template-objects-inl.h b/deps/v8/src/objects/template-objects-inl.h
index 3f84f53687..3718955fb7 100644
--- a/deps/v8/src/objects/template-objects-inl.h
+++ b/deps/v8/src/objects/template-objects-inl.h
@@ -18,8 +18,6 @@ namespace internal {
 TQ_OBJECT_CONSTRUCTORS_IMPL(TemplateObjectDescription)
 TQ_OBJECT_CONSTRUCTORS_IMPL(CachedTemplateObject)
 
-TQ_SMI_ACCESSORS(CachedTemplateObject, slot_id)
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/objects/template-objects.h b/deps/v8/src/objects/template-objects.h
index 085727ecb5..094485de50 100644
--- a/deps/v8/src/objects/template-objects.h
+++ b/deps/v8/src/objects/template-objects.h
@@ -20,8 +20,6 @@ namespace internal {
 class CachedTemplateObject final
     : public TorqueGeneratedCachedTemplateObject<CachedTemplateObject, Struct> {
  public:
-  DECL_INT_ACCESSORS(slot_id)
-
   static Handle<CachedTemplateObject> New(Isolate* isolate, int slot_id,
                                           Handle<JSArray> template_object,
                                           Handle<HeapObject> next);
diff --git a/deps/v8/src/objects/template.tq b/deps/v8/src/objects/template.tq
index 472d968855..d3e251aa16 100644
--- a/deps/v8/src/objects/template.tq
+++ b/deps/v8/src/objects/template.tq
@@ -23,6 +23,8 @@ extern class FunctionTemplateRareData extends Struct {
   instance_template: Object;
   instance_call_handler: Object;
   access_check_info: Object;
+  c_function: Foreign|Smi;
+  c_signature: Foreign|Smi;
 }
 
 @generateCppClass
@@ -41,7 +43,9 @@ extern class FunctionTemplateInfo extends TemplateInfo {
   // undefined.
   rare_data: HeapObject;
   shared_function_info: Object;
+  // Internal field to store a flag bitfield.
   flag: Smi;
+  // "length" property of the final JSFunction.
   length: Smi;
   // Either the_hole or a private symbol. Used to cache the result on
   // the receiver under the the cached_property_name when this
diff --git a/deps/v8/src/objects/templates-inl.h b/deps/v8/src/objects/templates-inl.h
index be58fc12bc..988230b7ae 100644
--- a/deps/v8/src/objects/templates-inl.h
+++ b/deps/v8/src/objects/templates-inl.h
@@ -24,9 +24,6 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(FunctionTemplateRareData)
 
 NEVER_READ_ONLY_SPACE_IMPL(TemplateInfo)
 
-TQ_SMI_ACCESSORS(TemplateInfo, number_of_properties)
-
-TQ_SMI_ACCESSORS(FunctionTemplateInfo, length)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, undetectable, kUndetectableBit)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, needs_access_check,
                kNeedsAccessCheckBit)
@@ -37,7 +34,6 @@ BOOL_ACCESSORS(FunctionTemplateInfo, flag, remove_prototype,
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, do_not_cache, kDoNotCacheBit)
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, accept_any_receiver,
                kAcceptAnyReceiver)
-TQ_SMI_ACCESSORS(FunctionTemplateInfo, flag)
 
 // static
 FunctionTemplateRareData FunctionTemplateInfo::EnsureFunctionTemplateRareData(
@@ -50,11 +46,11 @@ FunctionTemplateRareData FunctionTemplateInfo::EnsureFunctionTemplateRareData(
   }
 }
 
-#define RARE_ACCESSORS(Name, CamelName, Type)                                 \
+#define RARE_ACCESSORS(Name, CamelName, Type, Default)                        \
   DEF_GETTER(FunctionTemplateInfo, Get##CamelName, Type) {                    \
     HeapObject extra = rare_data(isolate);                                    \
     HeapObject undefined = GetReadOnlyRoots(isolate).undefined_value();       \
-    return extra == undefined ? undefined                                     \
+    return extra == undefined ? Default                                       \
                               : FunctionTemplateRareData::cast(extra).Name(); \
   }                                                                           \
   inline void FunctionTemplateInfo::Set##CamelName(                           \
@@ -65,14 +61,18 @@ FunctionTemplateRareData FunctionTemplateInfo::EnsureFunctionTemplateRareData(
     rare_data.set_##Name(*Name);                                              \
   }
 
-RARE_ACCESSORS(prototype_template, PrototypeTemplate, Object)
-RARE_ACCESSORS(prototype_provider_template, PrototypeProviderTemplate, Object)
-RARE_ACCESSORS(parent_template, ParentTemplate, Object)
-RARE_ACCESSORS(named_property_handler, NamedPropertyHandler, Object)
-RARE_ACCESSORS(indexed_property_handler, IndexedPropertyHandler, Object)
-RARE_ACCESSORS(instance_template, InstanceTemplate, Object)
-RARE_ACCESSORS(instance_call_handler, InstanceCallHandler, Object)
-RARE_ACCESSORS(access_check_info, AccessCheckInfo, Object)
+RARE_ACCESSORS(prototype_template, PrototypeTemplate, Object, undefined)
+RARE_ACCESSORS(prototype_provider_template, PrototypeProviderTemplate, Object,
+               undefined)
+RARE_ACCESSORS(parent_template, ParentTemplate, Object, undefined)
+RARE_ACCESSORS(named_property_handler, NamedPropertyHandler, Object, undefined)
+RARE_ACCESSORS(indexed_property_handler, IndexedPropertyHandler, Object,
+               undefined)
+RARE_ACCESSORS(instance_template, InstanceTemplate, Object, undefined)
+RARE_ACCESSORS(instance_call_handler, InstanceCallHandler, Object, undefined)
+RARE_ACCESSORS(access_check_info, AccessCheckInfo, Object, undefined)
+RARE_ACCESSORS(c_function, CFunction, Object, Smi(0))
+RARE_ACCESSORS(c_signature, CSignature, Object, Smi(0))
 #undef RARE_ACCESSORS
 
 bool FunctionTemplateInfo::instantiated() {
diff --git a/deps/v8/src/objects/templates.h b/deps/v8/src/objects/templates.h
index c2cc0855a7..01d40eb29a 100644
--- a/deps/v8/src/objects/templates.h
+++ b/deps/v8/src/objects/templates.h
@@ -16,7 +16,6 @@ namespace internal {
 class TemplateInfo : public TorqueGeneratedTemplateInfo<TemplateInfo, Struct> {
  public:
   NEVER_READ_ONLY_SPACE
-  DECL_INT_ACCESSORS(number_of_properties)
 
   static const int kFastTemplateInstantiationsCacheSize = 1 * KB;
 
@@ -82,13 +81,10 @@ class FunctionTemplateInfo
   DECL_RARE_ACCESSORS(instance_call_handler, InstanceCallHandler, Object)
 
   DECL_RARE_ACCESSORS(access_check_info, AccessCheckInfo, Object)
-#undef DECL_RARE_ACCESSORS
-
-  // Internal field to store a flag bitfield.
-  DECL_INT_ACCESSORS(flag)
 
-  // "length" property of the final JSFunction.
-  DECL_INT_ACCESSORS(length)
+  DECL_RARE_ACCESSORS(c_function, CFunction, Object)
+  DECL_RARE_ACCESSORS(c_signature, CSignature, Object)
+#undef DECL_RARE_ACCESSORS
 
   // Begin flag bits ---------------------
   DECL_BOOLEAN_ACCESSORS(undetectable)
@@ -120,6 +116,14 @@ class FunctionTemplateInfo
   static Handle<SharedFunctionInfo> GetOrCreateSharedFunctionInfo(
       Isolate* isolate, Handle<FunctionTemplateInfo> info,
       MaybeHandle<Name> maybe_name);
+
+  static Handle<SharedFunctionInfo> GetOrCreateSharedFunctionInfo(
+      OffThreadIsolate* isolate, Handle<FunctionTemplateInfo> info,
+      Handle<Name> maybe_name) {
+    // We don't support streaming compilation of scripts with natives, so we
+    // don't need an off-thread implementation of this.
+    UNREACHABLE();
+  }
   // Returns parent function template or a null FunctionTemplateInfo.
   inline FunctionTemplateInfo GetParent(Isolate* isolate);
   // Returns true if |object| is an instance of this function template.
diff --git a/deps/v8/src/parsing/func-name-inferrer.cc b/deps/v8/src/parsing/func-name-inferrer.cc
index 0b05176a77..b61224fbbb 100644
--- a/deps/v8/src/parsing/func-name-inferrer.cc
+++ b/deps/v8/src/parsing/func-name-inferrer.cc
@@ -45,7 +45,7 @@ void FuncNameInferrer::RemoveAsyncKeywordFromEnd() {
   }
 }
 
-const AstConsString* FuncNameInferrer::MakeNameFromStack() {
+AstConsString* FuncNameInferrer::MakeNameFromStack() {
   if (names_stack_.size() == 0) {
     return ast_value_factory_->empty_cons_string();
   }
@@ -70,7 +70,7 @@ const AstConsString* FuncNameInferrer::MakeNameFromStack() {
 }
 
 void FuncNameInferrer::InferFunctionsNames() {
-  const AstConsString* func_name = MakeNameFromStack();
+  AstConsString* func_name = MakeNameFromStack();
   for (FunctionLiteral* func : funcs_to_infer_) {
     func->set_raw_inferred_name(func_name);
   }
diff --git a/deps/v8/src/parsing/func-name-inferrer.h b/deps/v8/src/parsing/func-name-inferrer.h
index 66dd21f8cd..553e6fa512 100644
--- a/deps/v8/src/parsing/func-name-inferrer.h
+++ b/deps/v8/src/parsing/func-name-inferrer.h
@@ -110,7 +110,7 @@ class FuncNameInferrer {
   };
 
   // Constructs a full name in dotted notation from gathered names.
-  const AstConsString* MakeNameFromStack();
+  AstConsString* MakeNameFromStack();
 
   // Performs name inferring for added functions.
   void InferFunctionsNames();
diff --git a/deps/v8/src/parsing/literal-buffer.cc b/deps/v8/src/parsing/literal-buffer.cc
index 6400809a87..70b1903279 100644
--- a/deps/v8/src/parsing/literal-buffer.cc
+++ b/deps/v8/src/parsing/literal-buffer.cc
@@ -5,19 +5,25 @@
 #include "src/parsing/literal-buffer.h"
 
 #include "src/execution/isolate.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/heap/factory.h"
 #include "src/utils/memcopy.h"
 
 namespace v8 {
 namespace internal {
 
-Handle<String> LiteralBuffer::Internalize(Isolate* isolate) const {
+template <typename LocalIsolate>
+Handle<String> LiteralBuffer::Internalize(LocalIsolate* isolate) const {
   if (is_one_byte()) {
     return isolate->factory()->InternalizeString(one_byte_literal());
   }
   return isolate->factory()->InternalizeString(two_byte_literal());
 }
 
+template Handle<String> LiteralBuffer::Internalize(Isolate* isolate) const;
+template Handle<String> LiteralBuffer::Internalize(
+    OffThreadIsolate* isolate) const;
+
 int LiteralBuffer::NewCapacity(int min_capacity) {
   return min_capacity < (kMaxGrowth / (kGrowthFactor - 1))
              ? min_capacity * kGrowthFactor
diff --git a/deps/v8/src/parsing/literal-buffer.h b/deps/v8/src/parsing/literal-buffer.h
index 3d61a00393..56d5010b53 100644
--- a/deps/v8/src/parsing/literal-buffer.h
+++ b/deps/v8/src/parsing/literal-buffer.h
@@ -63,7 +63,8 @@ class LiteralBuffer final {
     is_one_byte_ = true;
   }
 
-  Handle<String> Internalize(Isolate* isolate) const;
+  template <typename LocalIsolate>
+  Handle<String> Internalize(LocalIsolate* isolate) const;
 
  private:
   static const int kInitialCapacity = 16;
diff --git a/deps/v8/src/parsing/parse-info.cc b/deps/v8/src/parsing/parse-info.cc
index 069696cef1..3723636804 100644
--- a/deps/v8/src/parsing/parse-info.cc
+++ b/deps/v8/src/parsing/parse-info.cc
@@ -7,6 +7,7 @@
 #include "src/ast/ast-source-ranges.h"
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/ast.h"
+#include "src/common/globals.h"
 #include "src/compiler-dispatcher/compiler-dispatcher.h"
 #include "src/heap/heap-inl.h"
 #include "src/logging/counters.h"
@@ -19,7 +20,7 @@
 namespace v8 {
 namespace internal {
 
-ParseInfo::ParseInfo(AccountingAllocator* zone_allocator)
+ParseInfo::ParseInfo(AccountingAllocator* zone_allocator, int script_id)
     : zone_(std::make_unique<Zone>(zone_allocator, ZONE_NAME)),
       flags_(0),
       extension_(nullptr),
@@ -28,7 +29,7 @@ ParseInfo::ParseInfo(AccountingAllocator* zone_allocator)
       hash_seed_(0),
       function_kind_(FunctionKind::kNormalFunction),
       function_syntax_kind_(FunctionSyntaxKind::kDeclaration),
-      script_id_(-1),
+      script_id_(script_id),
       start_position_(0),
       end_position_(0),
       parameters_end_pos_(kNoSourcePosition),
@@ -42,8 +43,9 @@ ParseInfo::ParseInfo(AccountingAllocator* zone_allocator)
       source_range_map_(nullptr),
       literal_(nullptr) {}
 
-ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
-    : ParseInfo(zone_allocator) {
+ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator,
+                     int script_id)
+    : ParseInfo(zone_allocator, script_id) {
   set_hash_seed(HashSeed(isolate));
   set_stack_limit(isolate->stack_guard()->real_climit());
   set_runtime_call_stats(isolate->counters()->runtime_call_stats());
@@ -69,9 +71,8 @@ ParseInfo::ParseInfo(Isolate* isolate, AccountingAllocator* zone_allocator)
 }
 
 ParseInfo::ParseInfo(Isolate* isolate)
-    : ParseInfo(isolate, isolate->allocator()) {
-  script_id_ = isolate->heap()->NextScriptId();
-  LOG(isolate, ScriptEvent(Logger::ScriptEventType::kReserveId, script_id_));
+    : ParseInfo(isolate, isolate->allocator(), isolate->GetNextScriptId()) {
+  LOG(isolate, ScriptEvent(Logger::ScriptEventType::kReserveId, script_id()));
 }
 
 template <typename T>
@@ -81,12 +82,16 @@ void ParseInfo::SetFunctionInfo(T function) {
   set_function_syntax_kind(function->syntax_kind());
   set_requires_instance_members_initializer(
       function->requires_instance_members_initializer());
+  set_class_scope_has_private_brand(function->class_scope_has_private_brand());
+  set_has_static_private_methods_or_accessors(
+      function->has_static_private_methods_or_accessors());
   set_toplevel(function->is_toplevel());
   set_is_oneshot_iife(function->is_oneshot_iife());
 }
 
 ParseInfo::ParseInfo(Isolate* isolate, SharedFunctionInfo shared)
-    : ParseInfo(isolate, isolate->allocator()) {
+    : ParseInfo(isolate, isolate->allocator(),
+                Script::cast(shared.script()).id()) {
   // Do not support re-parsing top-level function of a wrapped script.
   // TODO(yangguo): consider whether we need a top-level function in a
   //                wrapped script at all.
@@ -101,11 +106,7 @@ ParseInfo::ParseInfo(Isolate* isolate, SharedFunctionInfo shared)
   SetFunctionInfo(&shared);
 
   Script script = Script::cast(shared.script());
-  SetFlagsFromScript(isolate, script);
-
-  if (shared.HasOuterScopeInfo()) {
-    set_outer_scope_info(handle(shared.GetOuterScopeInfo(), isolate));
-  }
+  SetFlagsForFunctionFromScript(script);
 
   set_repl_mode(shared.is_repl_mode());
 
@@ -120,29 +121,27 @@ ParseInfo::ParseInfo(Isolate* isolate, SharedFunctionInfo shared)
 }
 
 ParseInfo::ParseInfo(Isolate* isolate, Script script)
-    : ParseInfo(isolate, isolate->allocator()) {
-  SetFlagsForToplevelCompileFromScript(isolate, script);
-  set_collect_type_profile(isolate->is_collecting_type_profile() &&
-                           script.IsUserJavaScript());
+    : ParseInfo(isolate, isolate->allocator(), script.id()) {
+  SetFlagsForToplevelCompileFromScript(isolate, script,
+                                       isolate->is_collecting_type_profile());
 }
 
 // static
 std::unique_ptr<ParseInfo> ParseInfo::FromParent(
     const ParseInfo* outer_parse_info, AccountingAllocator* zone_allocator,
     const FunctionLiteral* literal, const AstRawString* function_name) {
-  std::unique_ptr<ParseInfo> result =
-      std::make_unique<ParseInfo>(zone_allocator);
+  // Can't use make_unique because the constructor is private.
+  std::unique_ptr<ParseInfo> result(
+      new ParseInfo(zone_allocator, outer_parse_info->script_id_));
 
   // Replicate shared state of the outer_parse_info.
   result->flags_ = outer_parse_info->flags_;
-  result->script_id_ = outer_parse_info->script_id_;
   result->set_logger(outer_parse_info->logger());
   result->set_ast_string_constants(outer_parse_info->ast_string_constants());
   result->set_hash_seed(outer_parse_info->hash_seed());
 
   DCHECK_EQ(outer_parse_info->parameters_end_pos(), kNoSourcePosition);
   DCHECK_NULL(outer_parse_info->extension());
-  DCHECK(outer_parse_info->maybe_outer_scope_info().is_null());
 
   // Clone the function_name AstRawString into the ParseInfo's own
   // AstValueFactory.
@@ -165,19 +164,17 @@ ParseInfo::~ParseInfo() = default;
 
 DeclarationScope* ParseInfo::scope() const { return literal()->scope(); }
 
-Handle<Script> ParseInfo::CreateScript(Isolate* isolate, Handle<String> source,
+template <typename LocalIsolate>
+Handle<Script> ParseInfo::CreateScript(LocalIsolate* isolate,
+                                       Handle<String> source,
                                        ScriptOriginOptions origin_options,
-                                       REPLMode repl_mode,
                                        NativesFlag natives) {
   // Create a script object describing the script to be compiled.
-  Handle<Script> script;
-  if (script_id_ == -1) {
-    script = isolate->factory()->NewScript(source);
-  } else {
-    script = isolate->factory()->NewScriptWithId(source, script_id_);
-  }
+  DCHECK_GE(script_id_, 0);
+  Handle<Script> script =
+      isolate->factory()->NewScriptWithId(source, script_id_);
   if (isolate->NeedsSourcePositionsForProfiling()) {
-    Script::InitLineEnds(script);
+    Script::InitLineEnds(isolate, script);
   }
   switch (natives) {
     case EXTENSION_CODE:
@@ -190,12 +187,27 @@ Handle<Script> ParseInfo::CreateScript(Isolate* isolate, Handle<String> source,
       break;
   }
   script->set_origin_options(origin_options);
-  script->set_is_repl_mode(repl_mode == REPLMode::kYes);
+  script->set_is_repl_mode(is_repl_mode());
+  if (is_eval() && !is_wrapped_as_function()) {
+    script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
+  }
 
-  SetFlagsForToplevelCompileFromScript(isolate, *script);
+  CheckFlagsForToplevelCompileFromScript(*script,
+                                         isolate->is_collecting_type_profile());
   return script;
 }
 
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Script> ParseInfo::CreateScript(Isolate* isolate,
+                                           Handle<String> source,
+                                           ScriptOriginOptions origin_options,
+                                           NativesFlag natives);
+template EXPORT_TEMPLATE_DEFINE(V8_EXPORT_PRIVATE)
+    Handle<Script> ParseInfo::CreateScript(OffThreadIsolate* isolate,
+                                           Handle<String> source,
+                                           ScriptOriginOptions origin_options,
+                                           NativesFlag natives);
+
 AstValueFactory* ParseInfo::GetOrCreateAstValueFactory() {
   if (!ast_value_factory_.get()) {
     ast_value_factory_.reset(
@@ -206,6 +218,7 @@ AstValueFactory* ParseInfo::GetOrCreateAstValueFactory() {
 
 void ParseInfo::AllocateSourceRangeMap() {
   DCHECK(block_coverage_enabled());
+  DCHECK_NULL(source_range_map());
   set_source_range_map(new (zone()) SourceRangeMap(zone()));
 }
 
@@ -217,23 +230,51 @@ void ParseInfo::set_character_stream(
   character_stream_.swap(character_stream);
 }
 
-void ParseInfo::SetFlagsForToplevelCompileFromScript(Isolate* isolate,
-                                                     Script script) {
-  SetFlagsFromScript(isolate, script);
+void ParseInfo::SetFlagsForToplevelCompile(bool is_collecting_type_profile,
+                                           bool is_user_javascript,
+                                           LanguageMode language_mode,
+                                           REPLMode repl_mode) {
   set_allow_lazy_parsing();
   set_toplevel();
-  set_collect_type_profile(isolate->is_collecting_type_profile() &&
-                           script.IsUserJavaScript());
-  set_repl_mode(script.is_repl_mode());
+  set_collect_type_profile(is_user_javascript && is_collecting_type_profile);
+  set_language_mode(
+      stricter_language_mode(this->language_mode(), language_mode));
+  set_repl_mode(repl_mode == REPLMode::kYes);
+
+  if (V8_UNLIKELY(is_user_javascript && block_coverage_enabled())) {
+    AllocateSourceRangeMap();
+  }
+}
+
+template <typename LocalIsolate>
+void ParseInfo::SetFlagsForToplevelCompileFromScript(
+    LocalIsolate* isolate, Script script, bool is_collecting_type_profile) {
+  SetFlagsForFunctionFromScript(script);
+  SetFlagsForToplevelCompile(is_collecting_type_profile,
+                             script.IsUserJavaScript(), language_mode(),
+                             construct_repl_mode(script.is_repl_mode()));
 
   if (script.is_wrapped()) {
     set_function_syntax_kind(FunctionSyntaxKind::kWrapped);
   }
 }
 
-void ParseInfo::SetFlagsFromScript(Isolate* isolate, Script script) {
-  DCHECK(script_id_ == -1 || script_id_ == script.id());
-  script_id_ = script.id();
+void ParseInfo::CheckFlagsForToplevelCompileFromScript(
+    Script script, bool is_collecting_type_profile) {
+  CheckFlagsForFunctionFromScript(script);
+  DCHECK(allow_lazy_parsing());
+  DCHECK(is_toplevel());
+  DCHECK_EQ(collect_type_profile(),
+            is_collecting_type_profile && script.IsUserJavaScript());
+  DCHECK_EQ(is_repl_mode(), script.is_repl_mode());
+
+  if (script.is_wrapped()) {
+    DCHECK_EQ(function_syntax_kind(), FunctionSyntaxKind::kWrapped);
+  }
+}
+
+void ParseInfo::SetFlagsForFunctionFromScript(Script script) {
+  DCHECK_EQ(script_id_, script.id());
 
   set_eval(script.compilation_type() == Script::COMPILATION_TYPE_EVAL);
   set_module(script.origin_options().IsModule());
@@ -242,10 +283,17 @@ void ParseInfo::SetFlagsFromScript(Isolate* isolate, Script script) {
   if (block_coverage_enabled() && script.IsUserJavaScript()) {
     AllocateSourceRangeMap();
   }
+}
 
-  if (script.is_wrapped()) {
-    set_wrapped_arguments(handle(script.wrapped_arguments(), isolate));
-  }
+void ParseInfo::CheckFlagsForFunctionFromScript(Script script) {
+  DCHECK_EQ(script_id_, script.id());
+  // We set "is_eval" for wrapped functions to get an outer declaration scope.
+  // This is a bit hacky, but ok since we can't be both eval and wrapped.
+  DCHECK_EQ(is_eval() && !is_wrapped_as_function(),
+            script.compilation_type() == Script::COMPILATION_TYPE_EVAL);
+  DCHECK_EQ(is_module(), script.origin_options().IsModule());
+  DCHECK_IMPLIES(block_coverage_enabled() && script.IsUserJavaScript(),
+                 source_range_map() != nullptr);
 }
 
 void ParseInfo::ParallelTasks::Enqueue(ParseInfo* outer_parse_info,
diff --git a/deps/v8/src/parsing/parse-info.h b/deps/v8/src/parsing/parse-info.h
index 24f86e5bef..4430424eb9 100644
--- a/deps/v8/src/parsing/parse-info.h
+++ b/deps/v8/src/parsing/parse-info.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "include/v8.h"
+#include "src/base/export-template.h"
 #include "src/common/globals.h"
 #include "src/handles/handles.h"
 #include "src/objects/function-kind.h"
@@ -40,9 +41,7 @@ class Zone;
 // A container for the inputs, configuration options, and outputs of parsing.
 class V8_EXPORT_PRIVATE ParseInfo {
  public:
-  explicit ParseInfo(AccountingAllocator* zone_allocator);
   explicit ParseInfo(Isolate*);
-  ParseInfo(Isolate*, AccountingAllocator* zone_allocator);
   ParseInfo(Isolate* isolate, Script script);
   ParseInfo(Isolate* isolate, SharedFunctionInfo shared);
 
@@ -54,9 +53,10 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   ~ParseInfo();
 
-  Handle<Script> CreateScript(Isolate* isolate, Handle<String> source,
+  template <typename LocalIsolate>
+  EXPORT_TEMPLATE_DECLARE(V8_EXPORT_PRIVATE)
+  Handle<Script> CreateScript(LocalIsolate* isolate, Handle<String> source,
                               ScriptOriginOptions origin_options,
-                              REPLMode repl_mode = REPLMode::kNo,
                               NativesFlag natives = NOT_NATIVES_CODE);
 
   // Either returns the ast-value-factory associcated with this ParseInfo, or
@@ -90,6 +90,11 @@ class V8_EXPORT_PRIVATE ParseInfo {
   FLAG_ACCESSOR(kRequiresInstanceMembersInitializer,
                 requires_instance_members_initializer,
                 set_requires_instance_members_initializer)
+  FLAG_ACCESSOR(kClassScopeHasPrivateBrand, class_scope_has_private_brand,
+                set_class_scope_has_private_brand)
+  FLAG_ACCESSOR(kHasStaticPrivateMethodsOrAccessors,
+                has_static_private_methods_or_accessors,
+                set_has_static_private_methods_or_accessors)
   FLAG_ACCESSOR(kMightAlwaysOpt, might_always_opt, set_might_always_opt)
   FLAG_ACCESSOR(kAllowNativeSyntax, allow_natives_syntax,
                 set_allow_natives_syntax)
@@ -256,22 +261,12 @@ class V8_EXPORT_PRIVATE ParseInfo {
 
   ParallelTasks* parallel_tasks() { return parallel_tasks_.get(); }
 
-  void SetFlagsFromScript(Isolate* isolate, Script script);
+  void SetFlagsForToplevelCompile(bool is_collecting_type_profile,
+                                  bool is_user_javascript,
+                                  LanguageMode language_mode,
+                                  REPLMode repl_mode);
 
-  //--------------------------------------------------------------------------
-  // TODO(titzer): these should not be part of ParseInfo.
-  //--------------------------------------------------------------------------
-  Handle<FixedArray> wrapped_arguments() const { return wrapped_arguments_; }
-  void set_wrapped_arguments(Handle<FixedArray> wrapped_arguments) {
-    wrapped_arguments_ = wrapped_arguments;
-  }
-
-  MaybeHandle<ScopeInfo> maybe_outer_scope_info() const {
-    return maybe_outer_scope_info_;
-  }
-  void set_outer_scope_info(Handle<ScopeInfo> outer_scope_info) {
-    maybe_outer_scope_info_ = outer_scope_info;
-  }
+  void CheckFlagsForFunctionFromScript(Script script);
 
   int script_id() const { return script_id_; }
   //--------------------------------------------------------------------------
@@ -285,7 +280,17 @@ class V8_EXPORT_PRIVATE ParseInfo {
   }
 
  private:
-  void SetFlagsForToplevelCompileFromScript(Isolate* isolate, Script script);
+  ParseInfo(AccountingAllocator* zone_allocator, int script_id);
+  ParseInfo(Isolate*, AccountingAllocator* zone_allocator, int script_id);
+
+  void SetFlagsForFunctionFromScript(Script script);
+
+  template <typename LocalIsolate>
+  void SetFlagsForToplevelCompileFromScript(LocalIsolate* isolate,
+                                            Script script,
+                                            bool is_collecting_type_profile);
+  void CheckFlagsForToplevelCompileFromScript(Script script,
+                                              bool is_collecting_type_profile);
 
   // Set function info flags based on those in either FunctionLiteral or
   // SharedFunctionInfo |function|
@@ -319,13 +324,14 @@ class V8_EXPORT_PRIVATE ParseInfo {
     kAllowHarmonyDynamicImport = 1u << 21,
     kAllowHarmonyImportMeta = 1u << 22,
     kAllowHarmonyOptionalChaining = 1u << 23,
-    kAllowHarmonyPrivateFields = 1u << 24,
+    kHasStaticPrivateMethodsOrAccessors = 1u << 24,
     kAllowHarmonyPrivateMethods = 1u << 25,
     kIsOneshotIIFE = 1u << 26,
     kCollectSourcePositions = 1u << 27,
     kAllowHarmonyNullish = 1u << 28,
     kAllowHarmonyTopLevelAwait = 1u << 29,
     kREPLMode = 1u << 30,
+    kClassScopeHasPrivateBrand = 1u << 31,
   };
 
   //------------- Inputs to parsing and scope analysis -----------------------
@@ -344,10 +350,6 @@ class V8_EXPORT_PRIVATE ParseInfo {
   int function_literal_id_;
   int max_function_literal_id_;
 
-  // TODO(titzer): Move handles out of ParseInfo.
-  Handle<FixedArray> wrapped_arguments_;
-  MaybeHandle<ScopeInfo> maybe_outer_scope_info_;
-
   //----------- Inputs+Outputs of parsing and scope analysis -----------------
   std::unique_ptr<Utf16CharacterStream> character_stream_;
   std::unique_ptr<ConsumedPreparseData> consumed_preparse_data_;
diff --git a/deps/v8/src/parsing/parser-base.h b/deps/v8/src/parsing/parser-base.h
index 16129a4c00..29e527ce2c 100644
--- a/deps/v8/src/parsing/parser-base.h
+++ b/deps/v8/src/parsing/parser-base.h
@@ -232,8 +232,6 @@ class ParserBase {
   using FuncNameInferrerState = typename Types::FuncNameInferrer::State;
   using SourceRange = typename Types::SourceRange;
   using SourceRangeScope = typename Types::SourceRangeScope;
-  using TargetT = typename Types::Target;
-  using TargetScopeT = typename Types::TargetScope;
 
   // All implementation-specific methods must be called through this.
   Impl* impl() { return static_cast<Impl*>(this); }
@@ -320,7 +318,6 @@ class ParserBase {
   int loop_nesting_depth() const {
     return function_state_->loop_nesting_depth();
   }
-
   int GetNextFunctionLiteralId() { return ++function_literal_id_; }
   int GetLastFunctionLiteralId() const { return function_literal_id_; }
 
@@ -370,6 +367,93 @@ class ParserBase {
     Scope* const outer_scope_;
   };
 
+  // ---------------------------------------------------------------------------
+  // Target is a support class to facilitate manipulation of the
+  // Parser's target_stack_ (the stack of potential 'break' and
+  // 'continue' statement targets). Upon construction, a new target is
+  // added; it is removed upon destruction.
+
+  // |labels| is a list of all labels that can be used as a target for break.
+  // |own_labels| is a list of all labels that an iteration statement is
+  // directly prefixed with, i.e. all the labels that a continue statement in
+  // the body can use to continue this iteration statement. This is always a
+  // subset of |labels|.
+  //
+  // Example: "l1: { l2: if (b) l3: l4: for (;;) s }"
+  // labels() of the Block will be l1.
+  // labels() of the ForStatement will be l2, l3, l4.
+  // own_labels() of the ForStatement will be l3, l4.
+  class Target {
+   public:
+    enum TargetType { TARGET_FOR_ANONYMOUS, TARGET_FOR_NAMED_ONLY };
+
+    Target(ParserBase* parser, BreakableStatementT statement,
+           ZonePtrList<const AstRawString>* labels,
+           ZonePtrList<const AstRawString>* own_labels, TargetType target_type)
+        : stack_(parser->function_state_->target_stack_address()),
+          statement_(statement),
+          labels_(labels),
+          own_labels_(own_labels),
+          target_type_(target_type),
+          previous_(*stack_) {
+      DCHECK_IMPLIES(Impl::IsIterationStatement(statement_),
+                     target_type == Target::TARGET_FOR_ANONYMOUS);
+      DCHECK_IMPLIES(!Impl::IsIterationStatement(statement_),
+                     own_labels == nullptr);
+      *stack_ = this;
+    }
+
+    ~Target() { *stack_ = previous_; }
+
+    const Target* previous() const { return previous_; }
+    const BreakableStatementT statement() const { return statement_; }
+    const ZonePtrList<const AstRawString>* labels() const { return labels_; }
+    const ZonePtrList<const AstRawString>* own_labels() const {
+      return own_labels_;
+    }
+    bool is_iteration() const { return Impl::IsIterationStatement(statement_); }
+    bool is_target_for_anonymous() const {
+      return target_type_ == TARGET_FOR_ANONYMOUS;
+    }
+
+   private:
+    Target** const stack_;
+    const BreakableStatementT statement_;
+    const ZonePtrList<const AstRawString>* const labels_;
+    const ZonePtrList<const AstRawString>* const own_labels_;
+    const TargetType target_type_;
+    Target* const previous_;
+  };
+
+  Target* target_stack() { return *function_state_->target_stack_address(); }
+
+  BreakableStatementT LookupBreakTarget(IdentifierT label) {
+    bool anonymous = impl()->IsNull(label);
+    for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
+      if ((anonymous && t->is_target_for_anonymous()) ||
+          (!anonymous &&
+           ContainsLabel(t->labels(),
+                         impl()->GetRawNameFromIdentifier(label)))) {
+        return t->statement();
+      }
+    }
+    return impl()->NullStatement();
+  }
+
+  IterationStatementT LookupContinueTarget(IdentifierT label) {
+    bool anonymous = impl()->IsNull(label);
+    for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
+      if (!t->is_iteration()) continue;
+
+      DCHECK(t->is_target_for_anonymous());
+      if (anonymous || ContainsLabel(t->own_labels(),
+                                     impl()->GetRawNameFromIdentifier(label))) {
+        return impl()->AsIterationStatement(t->statement());
+      }
+    }
+    return impl()->NullStatement();
+  }
+
   class FunctionState final : public BlockState {
    public:
     FunctionState(FunctionState** function_state_stack, Scope** scope_stack,
@@ -427,7 +511,7 @@ class ParserBase {
       PointerWithPayload<FunctionState, bool, 1> state_and_prev_value_;
     };
 
-    class LoopScope {
+    class LoopScope final {
      public:
       explicit LoopScope(FunctionState* function_state)
           : function_state_(function_state) {
@@ -442,6 +526,8 @@ class ParserBase {
 
     int loop_nesting_depth() const { return loop_nesting_depth_; }
 
+    Target** target_stack_address() { return &target_stack_; }
+
    private:
     // Properties count estimation.
     int expected_property_count_;
@@ -455,6 +541,7 @@ class ParserBase {
     FunctionState** function_state_stack_;
     FunctionState* outer_function_state_;
     DeclarationScope* scope_;
+    Target* target_stack_ = nullptr;  // for break, continue statements
 
     // A reason, if any, why this function should not be optimized.
     BailoutReason dont_optimize_reason_;
@@ -539,6 +626,7 @@ class ParserBase {
           has_name_static_property(false),
           has_static_computed_names(false),
           has_static_class_fields(false),
+          has_static_private_methods(false),
           has_instance_members(false),
           requires_brand(false),
           is_anonymous(false),
@@ -557,6 +645,7 @@ class ParserBase {
     bool has_name_static_property;
     bool has_static_computed_names;
     bool has_static_class_fields;
+    bool has_static_private_methods;
     bool has_instance_members;
     bool requires_brand;
     bool is_anonymous;
@@ -623,6 +712,46 @@ class ParserBase {
     bool is_rest;
   };
 
+  void DeclareLabel(ZonePtrList<const AstRawString>** labels,
+                    ZonePtrList<const AstRawString>** own_labels,
+                    const AstRawString* label) {
+    if (ContainsLabel(*labels, label) || TargetStackContainsLabel(label)) {
+      ReportMessage(MessageTemplate::kLabelRedeclaration, label);
+      return;
+    }
+
+    // Add {label} to both {labels} and {own_labels}.
+    if (*labels == nullptr) {
+      DCHECK_NULL(*own_labels);
+      *labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
+      *own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
+    } else {
+      if (*own_labels == nullptr) {
+        *own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
+      }
+    }
+    (*labels)->Add(label, zone());
+    (*own_labels)->Add(label, zone());
+  }
+
+  bool ContainsLabel(const ZonePtrList<const AstRawString>* labels,
+                     const AstRawString* label) {
+    DCHECK_NOT_NULL(label);
+    if (labels != nullptr) {
+      for (int i = labels->length(); i-- > 0;) {
+        if (labels->at(i) == label) return true;
+      }
+    }
+    return false;
+  }
+
+  bool TargetStackContainsLabel(const AstRawString* label) {
+    for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
+      if (ContainsLabel(t->labels(), label)) return true;
+    }
+    return false;
+  }
+
   ClassLiteralProperty::Kind ClassPropertyKindFor(ParsePropertyKind kind) {
     switch (kind) {
       case ParsePropertyKind::kAccessorGetter:
@@ -2092,7 +2221,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseProperty(
 
     case Token::BIGINT: {
       Consume(Token::BIGINT);
-      prop_info->name = impl()->GetNumberAsSymbol();
+      prop_info->name = impl()->GetSymbol();
       is_array_index = impl()->IsArrayIndex(prop_info->name, &index);
       break;
     }
@@ -4436,8 +4565,9 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
     if (V8_UNLIKELY(prop_info.is_private)) {
       DCHECK(!is_constructor);
       class_info.requires_brand |= (!is_field && !prop_info.is_static);
-      class_info.has_private_methods |=
-          property_kind == ClassLiteralProperty::METHOD;
+      bool is_method = property_kind == ClassLiteralProperty::METHOD;
+      class_info.has_private_methods |= is_method;
+      class_info.has_static_private_methods |= is_method && prop_info.is_static;
       impl()->DeclarePrivateClassMember(class_scope, prop_info.name, property,
                                         property_kind, prop_info.is_static,
                                         &class_info);
@@ -4476,7 +4606,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   }
 
   if (class_info.requires_brand) {
-    // TODO(joyee): implement static brand checking
     class_scope->DeclareBrandVariable(
         ast_value_factory(), IsStaticFlag::kNotStatic, kNoSourcePosition);
   }
@@ -4809,10 +4938,6 @@ void ParserBase<Impl>::ParseStatementList(StatementListT* body,
     }
   }
 
-  // Allocate a target stack to use for this set of source elements. This way,
-  // all scripts and functions get their own target stack thus avoiding illegal
-  // breaks and continues across functions.
-  TargetScopeT target_scope(this);
   while (peek() != end_token) {
     StatementT stat = ParseStatementListItem();
     if (impl()->IsNull(stat)) return;
@@ -4932,8 +5057,9 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseStatement(
       // put the labels there.
       if (labels == nullptr) return ParseTryStatement();
       StatementListT statements(pointer_buffer());
-      BlockT result = factory()->NewBlock(false, labels);
-      TargetT target(this, result);
+      BlockT result = factory()->NewBlock(false, true);
+      Target target(this, result, labels, nullptr,
+                    Target::TARGET_FOR_NAMED_ONLY);
       StatementT statement = ParseTryStatement();
       statements.Add(statement);
       result->InitializeStatements(statements, zone());
@@ -4981,7 +5107,7 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
   //   '{' StatementList '}'
 
   // Parse the statements and collect escaping labels.
-  BlockT body = factory()->NewBlock(false, labels);
+  BlockT body = factory()->NewBlock(false, labels != nullptr);
   StatementListT statements(pointer_buffer());
 
   CheckStackOverflow();
@@ -4989,7 +5115,7 @@ typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
   {
     BlockState block_state(zone(), &scope_);
     scope()->set_start_position(peek_position());
-    TargetT target(this, body);
+    Target target(this, body, labels, nullptr, Target::TARGET_FOR_NAMED_ONLY);
 
     Expect(Token::LBRACE);
 
@@ -5214,11 +5340,11 @@ ParserBase<Impl>::ParseContinueStatement() {
     // ECMA allows "eval" or "arguments" as labels even in strict mode.
     label = ParseIdentifier();
   }
-  IterationStatementT target = impl()->LookupContinueTarget(label);
+  IterationStatementT target = LookupContinueTarget(label);
   if (impl()->IsNull(target)) {
     // Illegal continue statement.
     MessageTemplate message = MessageTemplate::kIllegalContinue;
-    BreakableStatementT breakable_target = impl()->LookupBreakTarget(label);
+    BreakableStatementT breakable_target = LookupBreakTarget(label);
     if (impl()->IsNull(label)) {
       message = MessageTemplate::kNoIterationStatement;
     } else if (impl()->IsNull(breakable_target)) {
@@ -5250,11 +5376,12 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseBreakStatement(
   }
   // Parse labeled break statements that target themselves into
   // empty statements, e.g. 'l1: l2: l3: break l2;'
-  if (!impl()->IsNull(label) && impl()->ContainsLabel(labels, label)) {
+  if (!impl()->IsNull(label) &&
+      impl()->ContainsLabel(labels, impl()->GetRawNameFromIdentifier(label))) {
     ExpectSemicolon();
     return factory()->EmptyStatement();
   }
-  BreakableStatementT target = impl()->LookupBreakTarget(label);
+  BreakableStatementT target = LookupBreakTarget(label);
   if (impl()->IsNull(target)) {
     // Illegal break statement.
     MessageTemplate message = MessageTemplate::kIllegalBreak;
@@ -5349,9 +5476,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseDoWhileStatement(
   //   'do' Statement 'while' '(' Expression ')' ';'
   typename FunctionState::LoopScope loop_scope(function_state_);
 
-  auto loop =
-      factory()->NewDoWhileStatement(labels, own_labels, peek_position());
-  TargetT target(this, loop);
+  auto loop = factory()->NewDoWhileStatement(peek_position());
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   SourceRange body_range;
   StatementT body = impl()->NullStatement();
@@ -5389,8 +5515,8 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWhileStatement(
   //   'while' '(' Expression ')' Statement
   typename FunctionState::LoopScope loop_scope(function_state_);
 
-  auto loop = factory()->NewWhileStatement(labels, own_labels, peek_position());
-  TargetT target(this, loop);
+  auto loop = factory()->NewWhileStatement(peek_position());
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   SourceRange body_range;
   StatementT body = impl()->NullStatement();
@@ -5438,7 +5564,6 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
   // CaseClause ::
   //   'case' Expression ':' StatementList
   //   'default' ':' StatementList
-
   int switch_pos = peek_position();
 
   Consume(Token::SWITCH);
@@ -5446,14 +5571,14 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
   ExpressionT tag = ParseExpression();
   Expect(Token::RPAREN);
 
-  auto switch_statement =
-      factory()->NewSwitchStatement(labels, tag, switch_pos);
+  auto switch_statement = factory()->NewSwitchStatement(tag, switch_pos);
 
   {
     BlockState cases_block_state(zone(), &scope_);
     scope()->set_start_position(switch_pos);
     scope()->SetNonlinear();
-    TargetT target(this, switch_statement);
+    Target target(this, switch_statement, labels, nullptr,
+                  Target::TARGET_FOR_ANONYMOUS);
 
     bool default_seen = false;
     Expect(Token::LBRACE);
@@ -5788,9 +5913,8 @@ ParserBase<Impl>::ParseForEachStatementWithDeclarations(
 
   BlockT init_block = impl()->RewriteForVarInLegacy(*for_info);
 
-  auto loop = factory()->NewForEachStatement(for_info->mode, labels, own_labels,
-                                             stmt_pos);
-  TargetT target(this, loop);
+  auto loop = factory()->NewForEachStatement(for_info->mode, stmt_pos);
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   ExpressionT enumerable = impl()->NullExpression();
   if (for_info->mode == ForEachStatement::ITERATE) {
@@ -5852,9 +5976,8 @@ ParserBase<Impl>::ParseForEachStatementWithoutDeclarations(
     int stmt_pos, ExpressionT expression, int lhs_beg_pos, int lhs_end_pos,
     ForInfo* for_info, ZonePtrList<const AstRawString>* labels,
     ZonePtrList<const AstRawString>* own_labels) {
-  auto loop = factory()->NewForEachStatement(for_info->mode, labels, own_labels,
-                                             stmt_pos);
-  TargetT target(this, loop);
+  auto loop = factory()->NewForEachStatement(for_info->mode, stmt_pos);
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   ExpressionT enumerable = impl()->NullExpression();
   if (for_info->mode == ForEachStatement::ITERATE) {
@@ -5943,8 +6066,8 @@ typename ParserBase<Impl>::ForStatementT ParserBase<Impl>::ParseStandardForLoop(
     ZonePtrList<const AstRawString>* own_labels, ExpressionT* cond,
     StatementT* next, StatementT* body) {
   CheckStackOverflow();
-  ForStatementT loop = factory()->NewForStatement(labels, own_labels, stmt_pos);
-  TargetT target(this, loop);
+  ForStatementT loop = factory()->NewForStatement(stmt_pos);
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   if (peek() != Token::SEMICOLON) {
     *cond = ParseExpression();
@@ -5988,13 +6111,12 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForAwaitStatement(
   scope()->set_start_position(scanner()->location().beg_pos);
   scope()->set_is_hidden();
 
-  auto loop = factory()->NewForOfStatement(labels, own_labels, stmt_pos,
-                                           IteratorType::kAsync);
+  auto loop = factory()->NewForOfStatement(stmt_pos, IteratorType::kAsync);
   // Two suspends: one for next() and one for return()
   function_state_->AddSuspend();
   function_state_->AddSuspend();
 
-  TargetT target(this, loop);
+  Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
 
   ExpressionT each_variable = impl()->NullExpression();
 
diff --git a/deps/v8/src/parsing/parser.cc b/deps/v8/src/parsing/parser.cc
index 21beff8790..2a1ad0e98b 100644
--- a/deps/v8/src/parsing/parser.cc
+++ b/deps/v8/src/parsing/parser.cc
@@ -356,6 +356,11 @@ Expression* Parser::NewV8Intrinsic(const AstRawString* name,
   const Runtime::Function* function =
       Runtime::FunctionForName(name->raw_data(), name->length());
 
+  // Be more premissive when fuzzing. Intrinsics are not supported.
+  if (FLAG_allow_natives_for_fuzzing) {
+    return NewV8RuntimeFunctionForFuzzing(function, args, pos);
+  }
+
   if (function != nullptr) {
     // Check for possible name clash.
     DCHECK_EQ(Context::kNotFound,
@@ -382,6 +387,34 @@ Expression* Parser::NewV8Intrinsic(const AstRawString* name,
   return factory()->NewCallRuntime(context_index, args, pos);
 }
 
+// More permissive runtime-function creation on fuzzers.
+Expression* Parser::NewV8RuntimeFunctionForFuzzing(
+    const Runtime::Function* function, const ScopedPtrList<Expression>& args,
+    int pos) {
+  CHECK(FLAG_allow_natives_for_fuzzing);
+
+  // Intrinsics are not supported for fuzzing. Only allow whitelisted runtime
+  // functions. Also prevent later errors due to too few arguments and just
+  // ignore this call.
+  if (function == nullptr ||
+      !Runtime::IsWhitelistedForFuzzing(function->function_id) ||
+      function->nargs > args.length()) {
+    return factory()->NewUndefinedLiteral(kNoSourcePosition);
+  }
+
+  // Flexible number of arguments permitted.
+  if (function->nargs == -1) {
+    return factory()->NewCallRuntime(function, args, pos);
+  }
+
+  // Otherwise ignore superfluous arguments.
+  ScopedPtrList<Expression> permissive_args(pointer_buffer());
+  for (int i = 0; i < function->nargs; i++) {
+    permissive_args.Add(args.at(i));
+  }
+  return factory()->NewCallRuntime(function, permissive_args, pos);
+}
+
 Parser::Parser(ParseInfo* info)
     : ParserBase<Parser>(info->zone(), &scanner_, info->stack_limit(),
                          info->extension(), info->GetOrCreateAstValueFactory(),
@@ -394,7 +427,6 @@ Parser::Parser(ParseInfo* info)
       reusable_preparser_(nullptr),
       mode_(PARSE_EAGERLY),  // Lazy mode must be set explicitly.
       source_range_map_(info->source_range_map()),
-      target_stack_(nullptr),
       total_preparse_skipped_(0),
       consumed_preparse_data_(info->consumed_preparse_data()),
       preparse_data_buffer_(),
@@ -483,8 +515,9 @@ void MaybeProcessSourceRanges(ParseInfo* parse_info, Expression* root,
 
 }  // namespace
 
-FunctionLiteral* Parser::ParseProgram(Isolate* isolate, Handle<Script> script,
-                                      ParseInfo* info) {
+FunctionLiteral* Parser::ParseProgram(
+    Isolate* isolate, Handle<Script> script, ParseInfo* info,
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info) {
   // TODO(bmeurer): We temporarily need to pass allow_nesting = true here,
   // see comment for HistogramTimerScope class.
   DCHECK_EQ(script->id(), script_id());
@@ -501,9 +534,14 @@ FunctionLiteral* Parser::ParseProgram(Isolate* isolate, Handle<Script> script,
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
 
   // Initialize parser state.
-  DeserializeScopeChain(isolate, info, info->maybe_outer_scope_info(),
+  DeserializeScopeChain(isolate, info, maybe_outer_scope_info,
                         Scope::DeserializationMode::kIncludingVariables);
 
+  DCHECK_EQ(script->is_wrapped(), info->is_wrapped_as_function());
+  if (script->is_wrapped()) {
+    maybe_wrapped_arguments_ = handle(script->wrapped_arguments(), isolate);
+  }
+
   scanner_.Initialize();
   FunctionLiteral* result = DoParseProgram(isolate, info);
   MaybeResetCharacterStream(info, result);
@@ -533,7 +571,6 @@ FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
   // isolate will be nullptr.
   DCHECK_EQ(parsing_on_main_thread_, isolate != nullptr);
   DCHECK_NULL(scope_);
-  DCHECK_NULL(target_stack_);
 
   ParsingModeScope mode(this, allow_lazy_ ? PARSE_LAZILY : PARSE_EAGERLY);
   ResetFunctionLiteralId();
@@ -559,18 +596,6 @@ FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
     int beg_pos = scanner()->location().beg_pos;
     if (parsing_module_) {
       DCHECK(info->is_module());
-      // Declare the special module parameter.
-      auto name = ast_value_factory()->empty_string();
-      bool is_rest = false;
-      bool is_optional = false;
-      VariableMode mode = VariableMode::kVar;
-      bool was_added;
-      scope->DeclareLocal(name, mode, PARAMETER_VARIABLE, &was_added,
-                          Variable::DefaultInitializationFlag(mode));
-      DCHECK(was_added);
-      auto var = scope->DeclareParameter(name, VariableMode::kVar, is_optional,
-                                         is_rest, ast_value_factory(), beg_pos);
-      var->AllocateTo(VariableLocation::PARAMETER, 0);
 
       PrepareGeneratorVariables();
       Expression* initial_yield =
@@ -638,7 +663,7 @@ FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
     // conflicting var declarations with outer scope-info-backed scopes.
     if (info->is_eval()) {
       DCHECK(parsing_on_main_thread_);
-      info->ast_value_factory()->Internalize(isolate->factory());
+      info->ast_value_factory()->Internalize(isolate);
     }
     CheckConflictingVarDeclarations(scope);
 
@@ -652,7 +677,7 @@ FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
       }
     }
 
-    int parameter_count = parsing_module_ ? 1 : 0;
+    int parameter_count = 0;
     result = factory()->NewScriptOrEvalFunctionLiteral(
         scope, body, function_state.expected_property_count(), parameter_count);
     result->set_suspend_count(function_state.suspend_count());
@@ -660,9 +685,6 @@ FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
 
   info->set_max_function_literal_id(GetLastFunctionLiteralId());
 
-  // Make sure the target stack is empty.
-  DCHECK_NULL(target_stack_);
-
   if (has_error()) return nullptr;
 
   RecordFunctionLiteralSourceRange(result);
@@ -674,7 +696,7 @@ ZonePtrList<const AstRawString>* Parser::PrepareWrappedArguments(
     Isolate* isolate, ParseInfo* info, Zone* zone) {
   DCHECK(parsing_on_main_thread_);
   DCHECK_NOT_NULL(isolate);
-  Handle<FixedArray> arguments = info->wrapped_arguments();
+  Handle<FixedArray> arguments = maybe_wrapped_arguments_.ToHandleChecked();
   int arguments_length = arguments->length();
   ZonePtrList<const AstRawString>* arguments_for_wrapped_function =
       new (zone) ZonePtrList<const AstRawString>(arguments_length, zone);
@@ -780,10 +802,19 @@ FunctionLiteral* Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
 
-  DeserializeScopeChain(isolate, info, info->maybe_outer_scope_info(),
+  MaybeHandle<ScopeInfo> maybe_outer_scope_info;
+  if (shared_info->HasOuterScopeInfo()) {
+    maybe_outer_scope_info = handle(shared_info->GetOuterScopeInfo(), isolate);
+  }
+  DeserializeScopeChain(isolate, info, maybe_outer_scope_info,
                         Scope::DeserializationMode::kIncludingVariables);
   DCHECK_EQ(factory()->zone(), info->zone());
 
+  if (shared_info->is_wrapped()) {
+    maybe_wrapped_arguments_ = handle(
+        Script::cast(shared_info->script()).wrapped_arguments(), isolate);
+  }
+
   // Initialize parser state.
   Handle<String> name(shared_info->Name(), isolate);
   info->set_function_name(ast_value_factory()->GetString(name));
@@ -810,7 +841,7 @@ FunctionLiteral* Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
   if (V8_UNLIKELY(FLAG_log_function_events) && result != nullptr) {
     double ms = timer.Elapsed().InMillisecondsF();
     // We need to make sure that the debug-name is available.
-    ast_value_factory()->Internalize(isolate->factory());
+    ast_value_factory()->Internalize(isolate);
     DeclarationScope* function_scope = result->scope();
     std::unique_ptr<char[]> function_name = result->GetDebugName();
     LOG(isolate,
@@ -827,7 +858,6 @@ FunctionLiteral* Parser::DoParseFunction(Isolate* isolate, ParseInfo* info,
   DCHECK_EQ(parsing_on_main_thread_, isolate != nullptr);
   DCHECK_NOT_NULL(raw_name);
   DCHECK_NULL(scope_);
-  DCHECK_NULL(target_stack_);
 
   DCHECK(ast_value_factory());
   fni_.PushEnclosingName(raw_name);
@@ -946,13 +976,15 @@ FunctionLiteral* Parser::DoParseFunction(Isolate* isolate, ParseInfo* info,
     if (has_error()) return nullptr;
     result->set_requires_instance_members_initializer(
         info->requires_instance_members_initializer());
+    result->set_class_scope_has_private_brand(
+        info->class_scope_has_private_brand());
+    result->set_has_static_private_methods_or_accessors(
+        info->has_static_private_methods_or_accessors());
     if (info->is_oneshot_iife()) {
       result->mark_as_oneshot_iife();
     }
   }
 
-  // Make sure the target stack is empty.
-  DCHECK_NULL(target_stack_);
   DCHECK_IMPLIES(result,
                  info->function_literal_id() == result->function_literal_id());
   return result;
@@ -1580,43 +1612,6 @@ Statement* Parser::DeclareNative(const AstRawString* name, int pos) {
       pos);
 }
 
-void Parser::DeclareLabel(ZonePtrList<const AstRawString>** labels,
-                          ZonePtrList<const AstRawString>** own_labels,
-                          const AstRawString* label) {
-  // TODO(1240780): We don't check for redeclaration of labels during preparsing
-  // since keeping track of the set of active labels requires nontrivial changes
-  // to the way scopes are structured.  However, these are probably changes we
-  // want to make later anyway so we should go back and fix this then.
-  if (ContainsLabel(*labels, label) || TargetStackContainsLabel(label)) {
-    ReportMessage(MessageTemplate::kLabelRedeclaration, label);
-    return;
-  }
-
-  // Add {label} to both {labels} and {own_labels}.
-  if (*labels == nullptr) {
-    DCHECK_NULL(*own_labels);
-    *labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
-    *own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
-  } else {
-    if (*own_labels == nullptr) {
-      *own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
-    }
-  }
-  (*labels)->Add(label, zone());
-  (*own_labels)->Add(label, zone());
-}
-
-bool Parser::ContainsLabel(ZonePtrList<const AstRawString>* labels,
-                           const AstRawString* label) {
-  DCHECK_NOT_NULL(label);
-  if (labels != nullptr) {
-    for (int i = labels->length(); i-- > 0;) {
-      if (labels->at(i) == label) return true;
-    }
-  }
-  return false;
-}
-
 Block* Parser::IgnoreCompletion(Statement* statement) {
   Block* block = factory()->NewBlock(1, true);
   block->statements()->Add(statement, zone());
@@ -1812,6 +1807,11 @@ void Parser::ParseAndRewriteAsyncGeneratorFunctionBody(
     statements.Add(
         factory()->NewExpressionStatement(initial_yield, kNoSourcePosition));
     ParseStatementList(&statements, Token::RBRACE);
+    // Since the whole body is wrapped in a try-catch, make the implicit
+    // end-of-function return explicit to ensure BytecodeGenerator's special
+    // handling for ReturnStatements in async generators applies.
+    statements.Add(factory()->NewSyntheticAsyncReturnStatement(
+        factory()->NewUndefinedLiteral(kNoSourcePosition), kNoSourcePosition));
 
     // Don't create iterator result for async generators, as the resume methods
     // will create it.
@@ -2052,8 +2052,7 @@ Statement* Parser::DesugarLexicalBindingsInForStatement(
   // explicit break target, instead handing it directly to those nodes that
   // need to know about it. This should be safe because we don't run any code
   // in this function that looks up break targets.
-  ForStatement* outer_loop =
-      factory()->NewForStatement(nullptr, nullptr, kNoSourcePosition);
+  ForStatement* outer_loop = factory()->NewForStatement(kNoSourcePosition);
   outer_block->statements()->Add(outer_loop, zone());
   outer_block->set_scope(scope());
 
@@ -2992,6 +2991,12 @@ Expression* Parser::RewriteClassLiteral(ClassScope* block_scope,
         class_info->instance_fields->length());
   }
 
+  if (class_info->requires_brand) {
+    class_info->constructor->set_class_scope_has_private_brand(true);
+  }
+  if (class_info->has_static_private_methods) {
+    class_info->constructor->set_has_static_private_methods_or_accessors(true);
+  }
   ClassLiteral* class_literal = factory()->NewClassLiteral(
       block_scope, class_info->extends, class_info->constructor,
       class_info->public_members, class_info->private_members,
@@ -3044,41 +3049,9 @@ void Parser::InsertSloppyBlockFunctionVarBindings(DeclarationScope* scope) {
 // ----------------------------------------------------------------------------
 // Parser support
 
-bool Parser::TargetStackContainsLabel(const AstRawString* label) {
-  for (ParserTarget* t = target_stack_; t != nullptr; t = t->previous()) {
-    if (ContainsLabel(t->statement()->labels(), label)) return true;
-  }
-  return false;
-}
-
-BreakableStatement* Parser::LookupBreakTarget(const AstRawString* label) {
-  bool anonymous = label == nullptr;
-  for (ParserTarget* t = target_stack_; t != nullptr; t = t->previous()) {
-    BreakableStatement* stat = t->statement();
-    if ((anonymous && stat->is_target_for_anonymous()) ||
-        (!anonymous && ContainsLabel(stat->labels(), label))) {
-      return stat;
-    }
-  }
-  return nullptr;
-}
-
-IterationStatement* Parser::LookupContinueTarget(const AstRawString* label) {
-  bool anonymous = label == nullptr;
-  for (ParserTarget* t = target_stack_; t != nullptr; t = t->previous()) {
-    IterationStatement* stat = t->statement()->AsIterationStatement();
-    if (stat == nullptr) continue;
-
-    DCHECK(stat->is_target_for_anonymous());
-    if (anonymous || ContainsLabel(stat->own_labels(), label)) {
-      return stat;
-    }
-    if (ContainsLabel(stat->labels(), label)) break;
-  }
-  return nullptr;
-}
-
-void Parser::HandleSourceURLComments(Isolate* isolate, Handle<Script> script) {
+template <typename LocalIsolate>
+void Parser::HandleSourceURLComments(LocalIsolate* isolate,
+                                     Handle<Script> script) {
   Handle<String> source_url = scanner_.SourceUrl(isolate);
   if (!source_url.is_null()) {
     script->set_source_url(*source_url);
@@ -3089,6 +3062,11 @@ void Parser::HandleSourceURLComments(Isolate* isolate, Handle<Script> script) {
   }
 }
 
+template void Parser::HandleSourceURLComments(Isolate* isolate,
+                                              Handle<Script> script);
+template void Parser::HandleSourceURLComments(OffThreadIsolate* isolate,
+                                              Handle<Script> script);
+
 void Parser::UpdateStatistics(Isolate* isolate, Handle<Script> script) {
   // Move statistics to Isolate.
   for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
@@ -3117,7 +3095,6 @@ void Parser::ParseOnBackground(ParseInfo* info) {
   FunctionLiteral* result = nullptr;
 
   scanner_.Initialize();
-  DCHECK(info->maybe_outer_scope_info().is_null());
 
   DCHECK(original_scope_);
 
@@ -3134,6 +3111,7 @@ void Parser::ParseOnBackground(ParseInfo* info) {
         DoParseFunction(/* isolate = */ nullptr, info, info->function_name());
   }
   MaybeResetCharacterStream(info, result);
+  MaybeProcessSourceRanges(info, result, stack_limit_);
 
   info->set_literal(result);
 
diff --git a/deps/v8/src/parsing/parser.h b/deps/v8/src/parsing/parser.h
index d53ccc7fbd..fd24ffb3e8 100644
--- a/deps/v8/src/parsing/parser.h
+++ b/deps/v8/src/parsing/parser.h
@@ -122,8 +122,6 @@ struct ParserTypes<Parser> {
   using FuncNameInferrer = v8::internal::FuncNameInferrer;
   using SourceRange = v8::internal::SourceRange;
   using SourceRangeScope = v8::internal::SourceRangeScope;
-  using Target = ParserTarget;
-  using TargetScope = ParserTargetScope;
 };
 
 class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
@@ -157,7 +155,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   // Move statistics to Isolate
   void UpdateStatistics(Isolate* isolate, Handle<Script> script);
-  void HandleSourceURLComments(Isolate* isolate, Handle<Script> script);
+  template <typename LocalIsolate>
+  void HandleSourceURLComments(LocalIsolate* isolate, Handle<Script> script);
 
  private:
   friend class ParserBase<Parser>;
@@ -167,8 +166,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   friend class i::ParameterDeclarationParsingScope<ParserTypes<Parser>>;
   friend class i::ArrowHeadParsingScope<ParserTypes<Parser>>;
   friend bool v8::internal::parsing::ParseProgram(
-      ParseInfo*, Handle<Script>, Isolate*,
-      parsing::ReportErrorsAndStatisticsMode stats_mode);
+      ParseInfo*, Handle<Script>, MaybeHandle<ScopeInfo> maybe_outer_scope_info,
+      Isolate*, parsing::ReportErrorsAndStatisticsMode stats_mode);
   friend bool v8::internal::parsing::ParseFunction(
       ParseInfo*, Handle<SharedFunctionInfo> shared_info, Isolate*,
       parsing::ReportErrorsAndStatisticsMode stats_mode);
@@ -210,7 +209,8 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   // Returns nullptr if parsing failed.
   FunctionLiteral* ParseProgram(Isolate* isolate, Handle<Script> script,
-                                ParseInfo* info);
+                                ParseInfo* info,
+                                MaybeHandle<ScopeInfo> maybe_outer_scope_info);
 
   FunctionLiteral* ParseFunction(Isolate* isolate, ParseInfo* info,
                                  Handle<SharedFunctionInfo> shared_info);
@@ -279,11 +279,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   };
   ZonePtrList<const NamedImport>* ParseNamedImports(int pos);
   Statement* BuildInitializationBlock(DeclarationParsingResult* parsing_result);
-  void DeclareLabel(ZonePtrList<const AstRawString>** labels,
-                    ZonePtrList<const AstRawString>** own_labels,
-                    const AstRawString* label);
-  bool ContainsLabel(ZonePtrList<const AstRawString>* labels,
-                     const AstRawString* label);
   Expression* RewriteReturn(Expression* return_value, int pos);
   Statement* RewriteSwitchStatement(SwitchStatement* switch_statement,
                                     Scope* scope);
@@ -407,10 +402,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
                Scope* declaration_scope, bool* was_added, int var_begin_pos,
                int var_end_pos = kNoSourcePosition);
 
-  bool TargetStackContainsLabel(const AstRawString* label);
-  BreakableStatement* LookupBreakTarget(const AstRawString* label);
-  IterationStatement* LookupContinueTarget(const AstRawString* label);
-
   // Factory methods.
   FunctionLiteral* DefaultConstructor(const AstRawString* name, bool call_super,
                                       int pos, int end_pos);
@@ -727,6 +718,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
     return arg;
   }
 
+  IterationStatement* AsIterationStatement(BreakableStatement* s) {
+    return s->AsIterationStatement();
+  }
+
   void ReportUnexpectedTokenAt(
       Scanner::Location location, Token::Value token,
       MessageTemplate message = MessageTemplate::kUnexpectedToken);
@@ -750,6 +745,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
     return subject == nullptr;
   }
 
+  V8_INLINE static bool IsIterationStatement(Statement* subject) {
+    return subject->AsIterationStatement() != nullptr;
+  }
+
   // Non-null empty string.
   V8_INLINE const AstRawString* EmptyIdentifierString() const {
     return ast_value_factory()->empty_string();
@@ -833,6 +832,10 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   Expression* NewV8Intrinsic(const AstRawString* name,
                              const ScopedPtrList<Expression>& args, int pos);
 
+  Expression* NewV8RuntimeFunctionForFuzzing(
+      const Runtime::Function* function, const ScopedPtrList<Expression>& args,
+      int pos);
+
   V8_INLINE Statement* NewThrowStatement(Expression* exception, int pos) {
     return factory()->NewExpressionStatement(
         factory()->NewThrow(exception, pos), pos);
@@ -1041,11 +1044,11 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   PreParser* reusable_preparser_;
   Mode mode_;
 
+  MaybeHandle<FixedArray> maybe_wrapped_arguments_;
+
   SourceRangeMap* source_range_map_ = nullptr;
 
-  friend class ParserTarget;
   friend class ParserTargetScope;
-  ParserTarget* target_stack_;  // for break, continue statements
 
   ScriptCompiler::CompileOptions compile_options_;
 
@@ -1068,47 +1071,6 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   int parameters_end_pos_;
 };
 
-// ----------------------------------------------------------------------------
-// Target is a support class to facilitate manipulation of the
-// Parser's target_stack_ (the stack of potential 'break' and
-// 'continue' statement targets). Upon construction, a new target is
-// added; it is removed upon destruction.
-
-class ParserTarget {
- public:
-  ParserTarget(ParserBase<Parser>* parser, BreakableStatement* statement)
-      : variable_(&parser->impl()->target_stack_),
-        statement_(statement),
-        previous_(parser->impl()->target_stack_) {
-    parser->impl()->target_stack_ = this;
-  }
-
-  ~ParserTarget() { *variable_ = previous_; }
-
-  ParserTarget* previous() { return previous_; }
-  BreakableStatement* statement() { return statement_; }
-
- private:
-  ParserTarget** variable_;
-  BreakableStatement* statement_;
-  ParserTarget* previous_;
-};
-
-class ParserTargetScope {
- public:
-  explicit ParserTargetScope(ParserBase<Parser>* parser)
-      : variable_(&parser->impl()->target_stack_),
-        previous_(parser->impl()->target_stack_) {
-    parser->impl()->target_stack_ = nullptr;
-  }
-
-  ~ParserTargetScope() { *variable_ = previous_; }
-
- private:
-  ParserTarget** variable_;
-  ParserTarget* previous_;
-};
-
 }  // namespace internal
 }  // namespace v8
 
diff --git a/deps/v8/src/parsing/parsing.cc b/deps/v8/src/parsing/parsing.cc
index cb8334bc51..8a960cdc29 100644
--- a/deps/v8/src/parsing/parsing.cc
+++ b/deps/v8/src/parsing/parsing.cc
@@ -8,6 +8,7 @@
 
 #include "src/ast/ast.h"
 #include "src/execution/vm-state-inl.h"
+#include "src/handles/maybe-handles.h"
 #include "src/objects/objects-inl.h"
 #include "src/parsing/parse-info.h"
 #include "src/parsing/parser.h"
@@ -18,8 +19,9 @@ namespace v8 {
 namespace internal {
 namespace parsing {
 
-bool ParseProgram(ParseInfo* info, Handle<Script> script, Isolate* isolate,
-                  ReportErrorsAndStatisticsMode mode) {
+bool ParseProgram(ParseInfo* info, Handle<Script> script,
+                  MaybeHandle<ScopeInfo> maybe_outer_scope_info,
+                  Isolate* isolate, ReportErrorsAndStatisticsMode mode) {
   DCHECK(info->is_toplevel());
   DCHECK_NULL(info->literal());
 
@@ -38,7 +40,7 @@ bool ParseProgram(ParseInfo* info, Handle<Script> script, Isolate* isolate,
   // Ok to use Isolate here; this function is only called in the main thread.
   DCHECK(parser.parsing_on_main_thread_);
 
-  result = parser.ParseProgram(isolate, script, info);
+  result = parser.ParseProgram(isolate, script, info, maybe_outer_scope_info);
   info->set_literal(result);
   if (result) {
     info->set_language_mode(info->literal()->language_mode());
@@ -57,6 +59,11 @@ bool ParseProgram(ParseInfo* info, Handle<Script> script, Isolate* isolate,
   return (result != nullptr);
 }
 
+bool ParseProgram(ParseInfo* info, Handle<Script> script, Isolate* isolate,
+                  ReportErrorsAndStatisticsMode mode) {
+  return ParseProgram(info, script, kNullMaybeHandle, isolate, mode);
+}
+
 bool ParseFunction(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
                    Isolate* isolate, ReportErrorsAndStatisticsMode mode) {
   DCHECK(!info->is_toplevel());
@@ -83,7 +90,7 @@ bool ParseFunction(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
   result = parser.ParseFunction(isolate, info, shared_info);
   info->set_literal(result);
   if (result) {
-    info->ast_value_factory()->Internalize(isolate->factory());
+    info->ast_value_factory()->Internalize(isolate);
     if (info->is_eval()) {
       info->set_allow_eval_cache(parser.allow_eval_cache());
     }
@@ -102,11 +109,17 @@ bool ParseFunction(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
 bool ParseAny(ParseInfo* info, Handle<SharedFunctionInfo> shared_info,
               Isolate* isolate, ReportErrorsAndStatisticsMode mode) {
   DCHECK(!shared_info.is_null());
-  return info->is_toplevel()
-             ? ParseProgram(
-                   info, handle(Script::cast(shared_info->script()), isolate),
-                   isolate, mode)
-             : ParseFunction(info, shared_info, isolate, mode);
+  if (info->is_toplevel()) {
+    MaybeHandle<ScopeInfo> maybe_outer_scope_info;
+    if (shared_info->HasOuterScopeInfo()) {
+      maybe_outer_scope_info =
+          handle(shared_info->GetOuterScopeInfo(), isolate);
+    }
+    return ParseProgram(info,
+                        handle(Script::cast(shared_info->script()), isolate),
+                        maybe_outer_scope_info, isolate, mode);
+  }
+  return ParseFunction(info, shared_info, isolate, mode);
 }
 
 }  // namespace parsing
diff --git a/deps/v8/src/parsing/parsing.h b/deps/v8/src/parsing/parsing.h
index 9bce504c1e..f235017139 100644
--- a/deps/v8/src/parsing/parsing.h
+++ b/deps/v8/src/parsing/parsing.h
@@ -18,12 +18,21 @@ namespace parsing {
 enum class ReportErrorsAndStatisticsMode { kYes, kNo };
 
 // Parses the top-level source code represented by the parse info and sets its
-// function literal.  Returns false (and deallocates any allocated AST
-// nodes) if parsing failed.
+// function literal. Returns false (and deallocates any allocated AST nodes) if
+// parsing failed.
 V8_EXPORT_PRIVATE bool ParseProgram(
     ParseInfo* info, Handle<Script> script, Isolate* isolate,
     ReportErrorsAndStatisticsMode mode = ReportErrorsAndStatisticsMode::kYes);
 
+// Parses the top-level source code represented by the parse info and sets its
+// function literal. Allows passing an |outer_scope| for programs that exist in
+// another scope (e.g. eval). Returns false (and deallocates any allocated AST
+// nodes) if parsing failed.
+V8_EXPORT_PRIVATE bool ParseProgram(
+    ParseInfo* info, Handle<Script> script, MaybeHandle<ScopeInfo> outer_scope,
+    Isolate* isolate,
+    ReportErrorsAndStatisticsMode mode = ReportErrorsAndStatisticsMode::kYes);
+
 // Like ParseProgram but for an individual function which already has a
 // allocated shared function info.
 V8_EXPORT_PRIVATE bool ParseFunction(
diff --git a/deps/v8/src/parsing/pending-compilation-error-handler.cc b/deps/v8/src/parsing/pending-compilation-error-handler.cc
index ce514235a0..80d201d13f 100644
--- a/deps/v8/src/parsing/pending-compilation-error-handler.cc
+++ b/deps/v8/src/parsing/pending-compilation-error-handler.cc
@@ -16,7 +16,7 @@ namespace internal {
 
 Handle<String> PendingCompilationErrorHandler::MessageDetails::ArgumentString(
     Isolate* isolate) const {
-  if (arg_ != nullptr) return arg_->string().get<Factory>();
+  if (arg_ != nullptr) return arg_->string();
   if (char_arg_ != nullptr) {
     return isolate->factory()
         ->NewStringFromUtf8(CStrVector(char_arg_))
@@ -75,6 +75,12 @@ void PendingCompilationErrorHandler::ReportWarnings(Isolate* isolate,
   }
 }
 
+void PendingCompilationErrorHandler::ReportWarnings(OffThreadIsolate* isolate,
+                                                    Handle<Script> script) {
+  // TODO(leszeks): Do nothing, re-report on the main thread.
+  UNREACHABLE();
+}
+
 void PendingCompilationErrorHandler::ReportErrors(
     Isolate* isolate, Handle<Script> script,
     AstValueFactory* ast_value_factory) {
@@ -83,7 +89,7 @@ void PendingCompilationErrorHandler::ReportErrors(
   } else {
     DCHECK(has_pending_error());
     // Internalize ast values for throwing the pending error.
-    ast_value_factory->Internalize(isolate->factory());
+    ast_value_factory->Internalize(isolate);
     ThrowPendingError(isolate, script);
   }
 }
diff --git a/deps/v8/src/parsing/pending-compilation-error-handler.h b/deps/v8/src/parsing/pending-compilation-error-handler.h
index cb2908eaf8..b854c3849e 100644
--- a/deps/v8/src/parsing/pending-compilation-error-handler.h
+++ b/deps/v8/src/parsing/pending-compilation-error-handler.h
@@ -52,6 +52,7 @@ class PendingCompilationErrorHandler {
 
   // Handle warnings detected during compilation.
   void ReportWarnings(Isolate* isolate, Handle<Script> script);
+  void ReportWarnings(OffThreadIsolate* isolate, Handle<Script> script);
 
   V8_EXPORT_PRIVATE Handle<String> FormatErrorMessageForTest(
       Isolate* isolate) const;
diff --git a/deps/v8/src/parsing/preparse-data-impl.h b/deps/v8/src/parsing/preparse-data-impl.h
index a993fdf93f..11165da5ed 100644
--- a/deps/v8/src/parsing/preparse-data-impl.h
+++ b/deps/v8/src/parsing/preparse-data-impl.h
@@ -199,6 +199,7 @@ class ZonePreparseData : public ZoneObject {
                                      int child_length);
 
   Handle<PreparseData> Serialize(Isolate* isolate);
+  Handle<PreparseData> Serialize(OffThreadIsolate* isolate);
 
   int children_length() const { return static_cast<int>(children_.size()); }
 
diff --git a/deps/v8/src/parsing/preparse-data.cc b/deps/v8/src/parsing/preparse-data.cc
index 53c6256a5f..7161861b76 100644
--- a/deps/v8/src/parsing/preparse-data.cc
+++ b/deps/v8/src/parsing/preparse-data.cc
@@ -9,11 +9,13 @@
 #include "src/ast/scopes.h"
 #include "src/ast/variables.h"
 #include "src/handles/handles.h"
+#include "src/heap/off-thread-factory.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/shared-function-info.h"
 #include "src/parsing/parser.h"
 #include "src/parsing/preparse-data-impl.h"
 #include "src/parsing/preparser.h"
+#include "src/roots/roots.h"
 #include "src/zone/zone-list-inl.h"  // crbug.com/v8/8816
 
 namespace v8 {
@@ -431,6 +433,16 @@ Handle<PreparseData> PreparseDataBuilder::ByteData::CopyToHeap(
   return data;
 }
 
+Handle<PreparseData> PreparseDataBuilder::ByteData::CopyToOffThreadHeap(
+    OffThreadIsolate* isolate, int children_length) {
+  DCHECK(is_finalized_);
+  int data_length = zone_byte_data_.length();
+  Handle<PreparseData> data =
+      isolate->factory()->NewPreparseData(data_length, children_length);
+  data->copy_in(0, zone_byte_data_.begin(), data_length);
+  return data;
+}
+
 Handle<PreparseData> PreparseDataBuilder::Serialize(Isolate* isolate) {
   DCHECK(HasData());
   DCHECK(!ThisOrParentBailedOut());
@@ -447,6 +459,22 @@ Handle<PreparseData> PreparseDataBuilder::Serialize(Isolate* isolate) {
   return data;
 }
 
+Handle<PreparseData> PreparseDataBuilder::Serialize(OffThreadIsolate* isolate) {
+  DCHECK(HasData());
+  DCHECK(!ThisOrParentBailedOut());
+  Handle<PreparseData> data =
+      byte_data_.CopyToOffThreadHeap(isolate, num_inner_with_data_);
+  int i = 0;
+  DCHECK(finalized_children_);
+  for (const auto& builder : children_) {
+    if (!builder->HasData()) continue;
+    Handle<PreparseData> child_data = builder->Serialize(isolate);
+    data->set_child(i++, *child_data);
+  }
+  DCHECK_EQ(i, data->children_length());
+  return data;
+}
+
 ZonePreparseData* PreparseDataBuilder::Serialize(Zone* zone) {
   DCHECK(HasData());
   DCHECK(!ThisOrParentBailedOut());
@@ -473,6 +501,10 @@ class BuilderProducedPreparseData final : public ProducedPreparseData {
     return builder_->Serialize(isolate);
   }
 
+  Handle<PreparseData> Serialize(OffThreadIsolate* isolate) final {
+    return builder_->Serialize(isolate);
+  }
+
   ZonePreparseData* Serialize(Zone* zone) final {
     return builder_->Serialize(zone);
   }
@@ -491,6 +523,11 @@ class OnHeapProducedPreparseData final : public ProducedPreparseData {
     return data_;
   }
 
+  Handle<PreparseData> Serialize(OffThreadIsolate* isolate) final {
+    // Not required.
+    UNREACHABLE();
+  }
+
   ZonePreparseData* Serialize(Zone* zone) final {
     // Not required.
     UNREACHABLE();
@@ -508,6 +545,10 @@ class ZoneProducedPreparseData final : public ProducedPreparseData {
     return data_->Serialize(isolate);
   }
 
+  Handle<PreparseData> Serialize(OffThreadIsolate* isolate) final {
+    return data_->Serialize(isolate);
+  }
+
   ZonePreparseData* Serialize(Zone* zone) final { return data_; }
 
  private:
@@ -750,6 +791,22 @@ Handle<PreparseData> ZonePreparseData::Serialize(Isolate* isolate) {
   return result;
 }
 
+Handle<PreparseData> ZonePreparseData::Serialize(OffThreadIsolate* isolate) {
+  int data_size = static_cast<int>(byte_data()->size());
+  int child_data_length = children_length();
+  Handle<PreparseData> result =
+      isolate->factory()->NewPreparseData(data_size, child_data_length);
+  result->copy_in(0, byte_data()->data(), data_size);
+
+  for (int i = 0; i < child_data_length; i++) {
+    ZonePreparseData* child = get_child(i);
+    DCHECK_NOT_NULL(child);
+    Handle<PreparseData> child_data = child->Serialize(isolate);
+    result->set_child(i, *child_data);
+  }
+  return result;
+}
+
 ZoneConsumedPreparseData::ZoneConsumedPreparseData(Zone* zone,
                                                    ZonePreparseData* data)
     : data_(data), scope_data_wrapper_(data_->byte_data()) {
diff --git a/deps/v8/src/parsing/preparse-data.h b/deps/v8/src/parsing/preparse-data.h
index 581adfa1d5..409942f8c3 100644
--- a/deps/v8/src/parsing/preparse-data.h
+++ b/deps/v8/src/parsing/preparse-data.h
@@ -140,6 +140,8 @@ class V8_EXPORT_PRIVATE PreparseDataBuilder : public ZoneObject,
     void Finalize(Zone* zone);
 
     Handle<PreparseData> CopyToHeap(Isolate* isolate, int children_length);
+    Handle<PreparseData> CopyToOffThreadHeap(OffThreadIsolate* isolate,
+                                             int children_length);
     inline ZonePreparseData* CopyToZone(Zone* zone, int children_length);
 
     void Reserve(size_t bytes);
@@ -208,6 +210,7 @@ class V8_EXPORT_PRIVATE PreparseDataBuilder : public ZoneObject,
   friend class BuilderProducedPreparseData;
 
   Handle<PreparseData> Serialize(Isolate* isolate);
+  Handle<PreparseData> Serialize(OffThreadIsolate* isolate);
   ZonePreparseData* Serialize(Zone* zone);
 
   void FinalizeChildren(Zone* zone);
@@ -250,6 +253,11 @@ class ProducedPreparseData : public ZoneObject {
   // MaybeHandle.
   virtual Handle<PreparseData> Serialize(Isolate* isolate) = 0;
 
+  // If there is data (if the Scope contains skippable inner functions), move
+  // the data into the heap and return a Handle to it; otherwise return a null
+  // MaybeHandle.
+  virtual Handle<PreparseData> Serialize(OffThreadIsolate* isolate) = 0;
+
   // If there is data (if the Scope contains skippable inner functions), return
   // an off-heap ZonePreparseData representing the data; otherwise
   // return nullptr.
diff --git a/deps/v8/src/parsing/preparser.h b/deps/v8/src/parsing/preparser.h
index 291abd0558..3c1122ef00 100644
--- a/deps/v8/src/parsing/preparser.h
+++ b/deps/v8/src/parsing/preparser.h
@@ -416,6 +416,10 @@ class PreParserStatement {
     return PreParserStatement(kUnknownStatement);
   }
 
+  static PreParserStatement Iteration() {
+    return PreParserStatement(kIterationStatement);
+  }
+
   static PreParserStatement Null() {
     return PreParserStatement(kNullStatement);
   }
@@ -450,6 +454,8 @@ class PreParserStatement {
 
   bool IsNull() { return code_ == kNullStatement; }
 
+  bool IsIterationStatement() { return code_ == kIterationStatement; }
+
   bool IsEmptyStatement() {
     DCHECK(!IsNull());
     return code_ == kEmptyStatement;
@@ -478,6 +484,7 @@ class PreParserStatement {
     kEmptyStatement,
     kUnknownStatement,
     kJumpStatement,
+    kIterationStatement,
     kStringLiteralExpressionStatement,
   };
 
@@ -691,8 +698,7 @@ class PreParserFactory {
     return PreParserBlock::Default();
   }
 
-  PreParserBlock NewBlock(bool ignore_completion_value,
-                          ZonePtrList<const AstRawString>* labels) {
+  PreParserBlock NewBlock(bool ignore_completion_value, bool is_breakable) {
     return PreParserBlock::Default();
   }
 
@@ -737,20 +743,15 @@ class PreParserFactory {
     return PreParserStatement::Default();
   }
 
-  PreParserStatement NewDoWhileStatement(
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos) {
-    return PreParserStatement::Default();
+  PreParserStatement NewDoWhileStatement(int pos) {
+    return PreParserStatement::Iteration();
   }
 
-  PreParserStatement NewWhileStatement(
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos) {
-    return PreParserStatement::Default();
+  PreParserStatement NewWhileStatement(int pos) {
+    return PreParserStatement::Iteration();
   }
 
-  PreParserStatement NewSwitchStatement(ZonePtrList<const AstRawString>* labels,
-                                        const PreParserExpression& tag,
+  PreParserStatement NewSwitchStatement(const PreParserExpression& tag,
                                         int pos) {
     return PreParserStatement::Default();
   }
@@ -761,23 +762,17 @@ class PreParserFactory {
     return PreParserStatement::Default();
   }
 
-  PreParserStatement NewForStatement(
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos) {
-    return PreParserStatement::Default();
+  PreParserStatement NewForStatement(int pos) {
+    return PreParserStatement::Iteration();
   }
 
-  PreParserStatement NewForEachStatement(
-      ForEachStatement::VisitMode visit_mode,
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos) {
-    return PreParserStatement::Default();
+  PreParserStatement NewForEachStatement(ForEachStatement::VisitMode visit_mode,
+                                         int pos) {
+    return PreParserStatement::Iteration();
   }
 
-  PreParserStatement NewForOfStatement(
-      ZonePtrList<const AstRawString>* labels,
-      ZonePtrList<const AstRawString>* own_labels, int pos, IteratorType type) {
-    return PreParserStatement::Default();
+  PreParserStatement NewForOfStatement(int pos, IteratorType type) {
+    return PreParserStatement::Iteration();
   }
 
   PreParserExpression NewCallRuntime(
@@ -819,17 +814,6 @@ class PreParserFormalParameters : public FormalParametersBase {
   bool strict_parameter_error_ = false;
 };
 
-class PreParserTarget {
- public:
-  PreParserTarget(ParserBase<PreParser>* preparser,
-                  PreParserStatement statement) {}
-};
-
-class PreParserTargetScope {
- public:
-  explicit PreParserTargetScope(ParserBase<PreParser>* preparser) {}
-};
-
 class PreParserFuncNameInferrer {
  public:
   explicit PreParserFuncNameInferrer(AstValueFactory* avf) {}
@@ -904,8 +888,6 @@ struct ParserTypes<PreParser> {
   using FuncNameInferrer = PreParserFuncNameInferrer;
   using SourceRange = PreParserSourceRange;
   using SourceRangeScope = PreParserSourceRangeScope;
-  using Target = PreParserTarget;
-  using TargetScope = PreParserTargetScope;
 };
 
 
@@ -1070,18 +1052,6 @@ class PreParser : public ParserBase<PreParser> {
       const PreParserScopedStatementList* body, PreParserStatement block,
       const PreParserExpression& return_value) {}
 
-  V8_INLINE void DeclareLabel(ZonePtrList<const AstRawString>** labels,
-                              ZonePtrList<const AstRawString>** own_labels,
-                              const AstRawString* label) {
-    DCHECK(!parsing_module_ || !label->IsOneByteEqualTo("await"));
-  }
-
-  // TODO(nikolaos): The preparser currently does not keep track of labels.
-  V8_INLINE bool ContainsLabel(ZonePtrList<const AstRawString>* labels,
-                               const PreParserIdentifier& label) {
-    return false;
-  }
-
   V8_INLINE PreParserExpression
   RewriteReturn(const PreParserExpression& return_value, int pos) {
     return return_value;
@@ -1186,17 +1156,6 @@ class PreParser : public ParserBase<PreParser> {
   bool IdentifierEquals(const PreParserIdentifier& identifier,
                         const AstRawString* other);
 
-  // TODO(nikolaos): The preparser currently does not keep track of labels
-  // and targets.
-  V8_INLINE PreParserStatement
-  LookupBreakTarget(const PreParserIdentifier& label) {
-    return PreParserStatement::Default();
-  }
-  V8_INLINE PreParserStatement
-  LookupContinueTarget(const PreParserIdentifier& label) {
-    return PreParserStatement::Default();
-  }
-
   V8_INLINE PreParserStatement DeclareFunction(
       const PreParserIdentifier& variable_name,
       const PreParserExpression& function, VariableMode mode, VariableKind kind,
@@ -1498,7 +1457,7 @@ class PreParser : public ParserBase<PreParser> {
   V8_INLINE void ReportMessageAt(Scanner::Location source_location,
                                  MessageTemplate message,
                                  const PreParserIdentifier& arg) {
-    UNREACHABLE();
+    ReportMessageAt(source_location, message, arg.string_);
   }
 
   void ReportMessageAt(Scanner::Location source_location,
@@ -1512,6 +1471,8 @@ class PreParser : public ParserBase<PreParser> {
     return arg.string_;
   }
 
+  PreParserStatement AsIterationStatement(PreParserStatement s) { return s; }
+
   // "null" return type creators.
   V8_INLINE static PreParserIdentifier NullIdentifier() {
     return PreParserIdentifier::Null();
@@ -1538,6 +1499,10 @@ class PreParser : public ParserBase<PreParser> {
     return subject.IsNull();
   }
 
+  V8_INLINE static bool IsIterationStatement(PreParserStatement subject) {
+    return subject.IsIterationStatement();
+  }
+
   V8_INLINE PreParserIdentifier EmptyIdentifierString() const {
     PreParserIdentifier result = PreParserIdentifier::Default();
     result.string_ = ast_value_factory()->empty_string();
diff --git a/deps/v8/src/parsing/rewriter.cc b/deps/v8/src/parsing/rewriter.cc
index 013ea68fac..75ec661d2d 100644
--- a/deps/v8/src/parsing/rewriter.cc
+++ b/deps/v8/src/parsing/rewriter.cc
@@ -146,7 +146,7 @@ void Processor::VisitBlock(Block* node) {
   // returns 'undefined'. To obtain the same behavior with v8, we need
   // to prevent rewriting in that case.
   if (!node->ignore_completion_value()) {
-    BreakableScope scope(this, node->labels() != nullptr);
+    BreakableScope scope(this, node->is_breakable());
     Process(node->statements());
   }
   replacement_ = node;
diff --git a/deps/v8/src/parsing/scanner-character-streams.cc b/deps/v8/src/parsing/scanner-character-streams.cc
index 49c7e1f793..1414b3490b 100644
--- a/deps/v8/src/parsing/scanner-character-streams.cc
+++ b/deps/v8/src/parsing/scanner-character-streams.cc
@@ -792,10 +792,35 @@ std::unique_ptr<Utf16CharacterStream> ScannerStream::ForTesting(
 
 std::unique_ptr<Utf16CharacterStream> ScannerStream::ForTesting(
     const char* data, size_t length) {
+  if (data == nullptr) {
+    DCHECK_EQ(length, 0);
+
+    // We don't want to pass in a null pointer into the the character stream,
+    // because then the one-past-the-end pointer is undefined, so instead pass
+    // through this static array.
+    static const char non_null_empty_string[1] = {0};
+    data = non_null_empty_string;
+  }
+
   return std::unique_ptr<Utf16CharacterStream>(
       new BufferedCharacterStream<TestingStream>(
-          static_cast<size_t>(0), reinterpret_cast<const uint8_t*>(data),
-          static_cast<size_t>(length)));
+          0, reinterpret_cast<const uint8_t*>(data), length));
+}
+
+std::unique_ptr<Utf16CharacterStream> ScannerStream::ForTesting(
+    const uint16_t* data, size_t length) {
+  if (data == nullptr) {
+    DCHECK_EQ(length, 0);
+
+    // We don't want to pass in a null pointer into the the character stream,
+    // because then the one-past-the-end pointer is undefined, so instead pass
+    // through this static array.
+    static const uint16_t non_null_empty_uint16_t_string[1] = {0};
+    data = non_null_empty_uint16_t_string;
+  }
+
+  return std::unique_ptr<Utf16CharacterStream>(
+      new UnbufferedCharacterStream<TestingStream>(0, data, length));
 }
 
 Utf16CharacterStream* ScannerStream::For(
diff --git a/deps/v8/src/parsing/scanner-character-streams.h b/deps/v8/src/parsing/scanner-character-streams.h
index c4c7064013..09181356f0 100644
--- a/deps/v8/src/parsing/scanner-character-streams.h
+++ b/deps/v8/src/parsing/scanner-character-streams.h
@@ -31,6 +31,8 @@ class V8_EXPORT_PRIVATE ScannerStream {
   static std::unique_ptr<Utf16CharacterStream> ForTesting(const char* data);
   static std::unique_ptr<Utf16CharacterStream> ForTesting(const char* data,
                                                           size_t length);
+  static std::unique_ptr<Utf16CharacterStream> ForTesting(const uint16_t* data,
+                                                          size_t length);
 };
 
 }  // namespace internal
diff --git a/deps/v8/src/parsing/scanner.cc b/deps/v8/src/parsing/scanner.cc
index 5d5fbdbab6..91e4183d53 100644
--- a/deps/v8/src/parsing/scanner.cc
+++ b/deps/v8/src/parsing/scanner.cc
@@ -576,7 +576,8 @@ Token::Value Scanner::ScanTemplateSpan() {
   return result;
 }
 
-Handle<String> Scanner::SourceUrl(Isolate* isolate) const {
+template <typename LocalIsolate>
+Handle<String> Scanner::SourceUrl(LocalIsolate* isolate) const {
   Handle<String> tmp;
   if (source_url_.length() > 0) {
     tmp = source_url_.Internalize(isolate);
@@ -584,7 +585,11 @@ Handle<String> Scanner::SourceUrl(Isolate* isolate) const {
   return tmp;
 }
 
-Handle<String> Scanner::SourceMappingUrl(Isolate* isolate) const {
+template Handle<String> Scanner::SourceUrl(Isolate* isolate) const;
+template Handle<String> Scanner::SourceUrl(OffThreadIsolate* isolate) const;
+
+template <typename LocalIsolate>
+Handle<String> Scanner::SourceMappingUrl(LocalIsolate* isolate) const {
   Handle<String> tmp;
   if (source_mapping_url_.length() > 0) {
     tmp = source_mapping_url_.Internalize(isolate);
@@ -592,6 +597,10 @@ Handle<String> Scanner::SourceMappingUrl(Isolate* isolate) const {
   return tmp;
 }
 
+template Handle<String> Scanner::SourceMappingUrl(Isolate* isolate) const;
+template Handle<String> Scanner::SourceMappingUrl(
+    OffThreadIsolate* isolate) const;
+
 bool Scanner::ScanDigitsWithNumericSeparators(bool (*predicate)(uc32 ch),
                                               bool is_check_first_digit) {
   // we must have at least one digit after 'x'/'b'/'o'
diff --git a/deps/v8/src/parsing/scanner.h b/deps/v8/src/parsing/scanner.h
index 2e953f6e6a..bed63c9d4e 100644
--- a/deps/v8/src/parsing/scanner.h
+++ b/deps/v8/src/parsing/scanner.h
@@ -403,8 +403,10 @@ class V8_EXPORT_PRIVATE Scanner {
     return ScanTemplateSpan();
   }
 
-  Handle<String> SourceUrl(Isolate* isolate) const;
-  Handle<String> SourceMappingUrl(Isolate* isolate) const;
+  template <typename LocalIsolate>
+  Handle<String> SourceUrl(LocalIsolate* isolate) const;
+  template <typename LocalIsolate>
+  Handle<String> SourceMappingUrl(LocalIsolate* isolate) const;
 
   bool FoundHtmlComment() const { return found_html_comment_; }
 
diff --git a/deps/v8/src/profiler/heap-snapshot-generator.cc b/deps/v8/src/profiler/heap-snapshot-generator.cc
index c4f2777e14..2ae2222419 100644
--- a/deps/v8/src/profiler/heap-snapshot-generator.cc
+++ b/deps/v8/src/profiler/heap-snapshot-generator.cc
@@ -978,7 +978,7 @@ void V8HeapExplorer::ExtractContextReferences(HeapEntry* entry,
     int context_locals = scope_info.ContextLocalCount();
     for (int i = 0; i < context_locals; ++i) {
       String local_name = scope_info.ContextLocalName(i);
-      int idx = Context::MIN_CONTEXT_SLOTS + i;
+      int idx = scope_info.ContextHeaderLength() + i;
       SetContextReference(entry, local_name, context.get(idx),
                           Context::OffsetOfElementAt(idx));
     }
diff --git a/deps/v8/src/profiler/profile-generator-inl.h b/deps/v8/src/profiler/profile-generator-inl.h
index 9a8fd20448..4c44b8b4a3 100644
--- a/deps/v8/src/profiler/profile-generator-inl.h
+++ b/deps/v8/src/profiler/profile-generator-inl.h
@@ -16,7 +16,7 @@ CodeEntry::CodeEntry(CodeEventListener::LogEventsAndTags tag, const char* name,
                      const char* resource_name, int line_number,
                      int column_number,
                      std::unique_ptr<SourcePositionTable> line_info,
-                     Address instruction_start, bool is_shared_cross_origin)
+                     bool is_shared_cross_origin)
     : bit_field_(TagField::encode(tag) |
                  BuiltinIdField::encode(Builtins::builtin_count) |
                  SharedCrossOriginField::encode(is_shared_cross_origin)),
@@ -26,11 +26,11 @@ CodeEntry::CodeEntry(CodeEventListener::LogEventsAndTags tag, const char* name,
       column_number_(column_number),
       script_id_(v8::UnboundScript::kNoScriptId),
       position_(0),
-      line_info_(std::move(line_info)),
-      instruction_start_(instruction_start) {}
+      line_info_(std::move(line_info)) {}
 
-inline CodeEntry* ProfileGenerator::FindEntry(Address address) {
-  CodeEntry* entry = code_map_->FindEntry(address);
+inline CodeEntry* ProfileGenerator::FindEntry(Address address,
+                                              Address* out_instruction_start) {
+  CodeEntry* entry = code_map_->FindEntry(address, out_instruction_start);
   if (entry) entry->mark_used();
   return entry;
 }
diff --git a/deps/v8/src/profiler/profile-generator.cc b/deps/v8/src/profiler/profile-generator.cc
index 11821035d5..b8389f4350 100644
--- a/deps/v8/src/profiler/profile-generator.cc
+++ b/deps/v8/src/profiler/profile-generator.cc
@@ -229,8 +229,6 @@ void CodeEntry::print() const {
   base::OS::Print(" - column_number: %d\n", column_number_);
   base::OS::Print(" - script_id: %d\n", script_id_);
   base::OS::Print(" - position: %d\n", position_);
-  base::OS::Print(" - instruction_start: %p\n",
-                  reinterpret_cast<void*>(instruction_start_));
 
   if (line_info_) {
     line_info_->print();
@@ -494,6 +492,11 @@ CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
       profiler_(profiler),
       streaming_next_sample_(0),
       id_(++last_id_) {
+  // The startTime timestamp is not converted to Perfetto's clock domain and
+  // will get out of sync with other timestamps Perfetto knows about, including
+  // the automatic trace event "ts" timestamp. startTime is included for
+  // backward compatibility with the tracing protocol but the value of "ts"
+  // should be used instead (it is recorded nearly immediately after).
   auto value = TracedValue::Create();
   value->SetDouble("startTime", start_time_.since_origin().InMicroseconds());
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
@@ -603,6 +606,16 @@ void CpuProfile::StreamPendingTraceEvents() {
     value->EndDictionary();
   }
   if (streaming_next_sample_ != samples_.size()) {
+    // timeDeltas are computed within CLOCK_MONOTONIC. However, trace event
+    // "ts" timestamps are converted to CLOCK_BOOTTIME by Perfetto. To get
+    // absolute timestamps in CLOCK_BOOTTIME from timeDeltas, add them to
+    // the "ts" timestamp from the initial "Profile" trace event sent by
+    // CpuProfile::CpuProfile().
+    //
+    // Note that if the system is suspended and resumed while samples_ is
+    // captured, timeDeltas derived after resume will not be convertible to
+    // correct CLOCK_BOOTTIME time values (for instance, producing
+    // CLOCK_BOOTTIME time values in the middle of the suspended period).
     value->BeginArray("timeDeltas");
     base::TimeTicks lastTimestamp =
         streaming_next_sample_ ? samples_[streaming_next_sample_ - 1].timestamp
@@ -636,6 +649,12 @@ void CpuProfile::FinishProfile() {
   context_filter_ = nullptr;
   StreamPendingTraceEvents();
   auto value = TracedValue::Create();
+  // The endTime timestamp is not converted to Perfetto's clock domain and will
+  // get out of sync with other timestamps Perfetto knows about, including the
+  // automatic trace event "ts" timestamp. endTime is included for backward
+  // compatibility with the tracing protocol: its presence in "data" is used by
+  // devtools to identify the last ProfileChunk but the value of "ts" should be
+  // used instead (it is recorded nearly immediately after).
   value->SetDouble("endTime", end_time_.since_origin().InMicroseconds());
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
                               "ProfileChunk", id_, "data", std::move(value));
@@ -664,8 +683,6 @@ void CodeMap::AddCode(Address addr, CodeEntry* entry, unsigned size) {
   ClearCodesInRange(addr, addr + size);
   unsigned index = AddCodeEntry(addr, entry);
   code_map_.emplace(addr, CodeEntryMapInfo{index, size});
-  DCHECK(entry->instruction_start() == kNullAddress ||
-         addr == entry->instruction_start());
 }
 
 void CodeMap::ClearCodesInRange(Address start, Address end) {
@@ -683,17 +700,15 @@ void CodeMap::ClearCodesInRange(Address start, Address end) {
   code_map_.erase(left, right);
 }
 
-CodeEntry* CodeMap::FindEntry(Address addr) {
+CodeEntry* CodeMap::FindEntry(Address addr, Address* out_instruction_start) {
   auto it = code_map_.upper_bound(addr);
   if (it == code_map_.begin()) return nullptr;
   --it;
   Address start_address = it->first;
   Address end_address = start_address + it->second.size;
   CodeEntry* ret = addr < end_address ? entry(it->second.index) : nullptr;
-  if (ret && ret->instruction_start() != kNullAddress) {
-    DCHECK_EQ(start_address, ret->instruction_start());
-    DCHECK(addr >= start_address && addr < end_address);
-  }
+  DCHECK(!ret || (addr >= start_address && addr < end_address));
+  if (ret && out_instruction_start) *out_instruction_start = start_address;
   return ret;
 }
 
@@ -706,9 +721,6 @@ void CodeMap::MoveCode(Address from, Address to) {
   DCHECK(from + info.size <= to || to + info.size <= from);
   ClearCodesInRange(to, to + info.size);
   code_map_.emplace(to, info);
-
-  CodeEntry* entry = code_entries_[info.index].entry;
-  entry->set_instruction_start(to);
 }
 
 unsigned CodeMap::AddCodeEntry(Address start, CodeEntry* entry) {
@@ -886,13 +898,15 @@ void ProfileGenerator::RecordTickSample(const TickSample& sample) {
                              true});
     } else {
       Address attributed_pc = reinterpret_cast<Address>(sample.pc);
-      CodeEntry* pc_entry = FindEntry(attributed_pc);
+      Address pc_entry_instruction_start = kNullAddress;
+      CodeEntry* pc_entry =
+          FindEntry(attributed_pc, &pc_entry_instruction_start);
       // If there is no pc_entry, we're likely in native code. Find out if the
       // top of the stack (the return address) was pointing inside a JS
       // function, meaning that we have encountered a frameless invocation.
       if (!pc_entry && !sample.has_external_callback) {
         attributed_pc = reinterpret_cast<Address>(sample.tos);
-        pc_entry = FindEntry(attributed_pc);
+        pc_entry = FindEntry(attributed_pc, &pc_entry_instruction_start);
       }
       // If pc is in the function code before it set up stack frame or after the
       // frame was destroyed, SafeStackFrameIterator incorrectly thinks that
@@ -900,7 +914,7 @@ void ProfileGenerator::RecordTickSample(const TickSample& sample) {
       // caller's frame. Check for this case and just skip such samples.
       if (pc_entry) {
         int pc_offset =
-            static_cast<int>(attributed_pc - pc_entry->instruction_start());
+            static_cast<int>(attributed_pc - pc_entry_instruction_start);
         // TODO(petermarshall): pc_offset can still be negative in some cases.
         src_line = pc_entry->GetSourceLine(pc_offset);
         if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) {
@@ -932,12 +946,12 @@ void ProfileGenerator::RecordTickSample(const TickSample& sample) {
     for (unsigned i = 0; i < sample.frames_count; ++i) {
       Address stack_pos = reinterpret_cast<Address>(sample.stack[i]);
       Address native_context = reinterpret_cast<Address>(sample.contexts[i]);
-      CodeEntry* entry = FindEntry(stack_pos);
+      Address instruction_start = kNullAddress;
+      CodeEntry* entry = FindEntry(stack_pos, &instruction_start);
       int line_number = no_line_info;
       if (entry) {
         // Find out if the entry has an inlining stack associated.
-        int pc_offset =
-            static_cast<int>(stack_pos - entry->instruction_start());
+        int pc_offset = static_cast<int>(stack_pos - instruction_start);
         // TODO(petermarshall): pc_offset can still be negative in some cases.
         const std::vector<CodeEntryAndLineNumber>* inline_stack =
             entry->GetInlineStack(pc_offset);
@@ -1014,6 +1028,7 @@ CodeEntry* ProfileGenerator::EntryForVMState(StateTag tag) {
     case PARSER:
     case COMPILER:
     case BYTECODE_COMPILER:
+    case ATOMICS_WAIT:
     // DOM events handlers are reported as OTHER / EXTERNAL entries.
     // To avoid confusing people, let's put all these entries into
     // one bucket.
diff --git a/deps/v8/src/profiler/profile-generator.h b/deps/v8/src/profiler/profile-generator.h
index 38e31c5596..9f7ef34d18 100644
--- a/deps/v8/src/profiler/profile-generator.h
+++ b/deps/v8/src/profiler/profile-generator.h
@@ -65,7 +65,6 @@ class CodeEntry {
                    int line_number = v8::CpuProfileNode::kNoLineNumberInfo,
                    int column_number = v8::CpuProfileNode::kNoColumnNumberInfo,
                    std::unique_ptr<SourcePositionTable> line_info = nullptr,
-                   Address instruction_start = kNullAddress,
                    bool is_shared_cross_origin = false);
 
   const char* name() const { return name_; }
@@ -136,9 +135,6 @@ class CodeEntry {
   const std::vector<CodeEntryAndLineNumber>* GetInlineStack(
       int pc_offset) const;
 
-  void set_instruction_start(Address start) { instruction_start_ = start; }
-  Address instruction_start() const { return instruction_start_; }
-
   CodeEventListener::LogEventsAndTags tag() const {
     return TagField::decode(bit_field_);
   }
@@ -223,7 +219,6 @@ class CodeEntry {
   int script_id_;
   int position_;
   std::unique_ptr<SourcePositionTable> line_info_;
-  Address instruction_start_;
   std::unique_ptr<RareData> rare_data_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeEntry);
@@ -449,7 +444,7 @@ class V8_EXPORT_PRIVATE CodeMap {
 
   void AddCode(Address addr, CodeEntry* entry, unsigned size);
   void MoveCode(Address from, Address to);
-  CodeEntry* FindEntry(Address addr);
+  CodeEntry* FindEntry(Address addr, Address* out_instruction_start = nullptr);
   void Print();
 
  private:
@@ -533,7 +528,8 @@ class V8_EXPORT_PRIVATE ProfileGenerator {
   CodeMap* code_map() { return code_map_; }
 
  private:
-  CodeEntry* FindEntry(Address address);
+  CodeEntry* FindEntry(Address address,
+                       Address* out_instruction_start = nullptr);
   CodeEntry* EntryForVMState(StateTag tag);
 
   CpuProfilesCollection* profiles_;
diff --git a/deps/v8/src/profiler/profiler-listener.cc b/deps/v8/src/profiler/profiler-listener.cc
index 29eea0f4ca..654b751a6c 100644
--- a/deps/v8/src/profiler/profiler-listener.cc
+++ b/deps/v8/src/profiler/profiler-listener.cc
@@ -38,8 +38,7 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
   rec->instruction_start = code->InstructionStart();
   rec->entry = new CodeEntry(tag, GetName(name), CodeEntry::kEmptyResourceName,
                              CpuProfileNode::kNoLineNumberInfo,
-                             CpuProfileNode::kNoColumnNumberInfo, nullptr,
-                             code->InstructionStart());
+                             CpuProfileNode::kNoColumnNumberInfo, nullptr);
   rec->instruction_size = code->InstructionSize();
   DispatchCodeEvent(evt_rec);
 }
@@ -52,8 +51,7 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
   rec->instruction_start = code->InstructionStart();
   rec->entry = new CodeEntry(tag, GetName(*name), CodeEntry::kEmptyResourceName,
                              CpuProfileNode::kNoLineNumberInfo,
-                             CpuProfileNode::kNoColumnNumberInfo, nullptr,
-                             code->InstructionStart());
+                             CpuProfileNode::kNoColumnNumberInfo, nullptr);
   rec->instruction_size = code->InstructionSize();
   DispatchCodeEvent(evt_rec);
 }
@@ -68,8 +66,7 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
   rec->entry = new CodeEntry(tag, GetName(shared->DebugName()),
                              GetName(InferScriptName(*script_name, *shared)),
                              CpuProfileNode::kNoLineNumberInfo,
-                             CpuProfileNode::kNoColumnNumberInfo, nullptr,
-                             code->InstructionStart());
+                             CpuProfileNode::kNoColumnNumberInfo, nullptr);
   DCHECK(!code->IsCode());
   rec->entry->FillFunctionInfo(*shared);
   rec->instruction_size = code->InstructionSize();
@@ -164,7 +161,7 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
           std::unique_ptr<CodeEntry> inline_entry = std::make_unique<CodeEntry>(
               tag, GetFunctionName(*pos_info.shared), resource_name,
               start_pos_info.line + 1, start_pos_info.column + 1, nullptr,
-              code->InstructionStart(), inline_is_shared_cross_origin);
+              inline_is_shared_cross_origin);
           inline_entry->FillFunctionInfo(*pos_info.shared);
 
           // Create a canonical CodeEntry for each inlined frame and then re-use
@@ -182,8 +179,7 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
   rec->entry =
       new CodeEntry(tag, GetFunctionName(*shared),
                     GetName(InferScriptName(*script_name, *shared)), line,
-                    column, std::move(line_table),
-                    abstract_code->InstructionStart(), is_shared_cross_origin);
+                    column, std::move(line_table), is_shared_cross_origin);
   if (!inline_stacks.empty()) {
     rec->entry->SetInlineStacks(std::move(cached_inline_entries),
                                 std::move(inline_stacks));
@@ -200,10 +196,10 @@ void ProfilerListener::CodeCreateEvent(LogEventsAndTags tag,
   CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
   CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
   rec->instruction_start = code->instruction_start();
-  rec->entry = new CodeEntry(
-      tag, GetName(name), CodeEntry::kWasmResourceNamePrefix,
-      CpuProfileNode::kNoLineNumberInfo, CpuProfileNode::kNoColumnNumberInfo,
-      nullptr, code->instruction_start(), true);
+  rec->entry =
+      new CodeEntry(tag, GetName(name), CodeEntry::kWasmResourceNamePrefix,
+                    CpuProfileNode::kNoLineNumberInfo,
+                    CpuProfileNode::kNoColumnNumberInfo, nullptr, true);
   rec->instruction_size = code->instructions().length();
   DispatchCodeEvent(evt_rec);
 }
@@ -247,7 +243,7 @@ void ProfilerListener::RegExpCodeCreateEvent(Handle<AbstractCode> code,
   rec->entry = new CodeEntry(
       CodeEventListener::REG_EXP_TAG, GetConsName("RegExp: ", *source),
       CodeEntry::kEmptyResourceName, CpuProfileNode::kNoLineNumberInfo,
-      CpuProfileNode::kNoColumnNumberInfo, nullptr, code->InstructionStart());
+      CpuProfileNode::kNoColumnNumberInfo, nullptr);
   rec->instruction_size = code->InstructionSize();
   DispatchCodeEvent(evt_rec);
 }
diff --git a/deps/v8/src/profiler/sampling-heap-profiler.cc b/deps/v8/src/profiler/sampling-heap-profiler.cc
index f5aa1dc3a0..e7d780e084 100644
--- a/deps/v8/src/profiler/sampling-heap-profiler.cc
+++ b/deps/v8/src/profiler/sampling-heap-profiler.cc
@@ -178,6 +178,9 @@ SamplingHeapProfiler::AllocationNode* SamplingHeapProfiler::AddStack() {
       case IDLE:
         name = "(IDLE)";
         break;
+      // Treat atomics wait as a normal JS event; we don't care about the
+      // difference for allocations.
+      case ATOMICS_WAIT:
       case JS:
         name = "(JS)";
         break;
diff --git a/deps/v8/src/profiler/strings-storage.cc b/deps/v8/src/profiler/strings-storage.cc
index eeb5261f2c..92143e1ce0 100644
--- a/deps/v8/src/profiler/strings-storage.cc
+++ b/deps/v8/src/profiler/strings-storage.cc
@@ -22,7 +22,7 @@ StringsStorage::StringsStorage() : names_(StringsMatch) {}
 StringsStorage::~StringsStorage() {
   for (base::HashMap::Entry* p = names_.Start(); p != nullptr;
        p = names_.Next(p)) {
-    DeleteArray(reinterpret_cast<const char*>(p->value));
+    DeleteArray(reinterpret_cast<const char*>(p->key));
   }
 }
 
@@ -34,9 +34,10 @@ const char* StringsStorage::GetCopy(const char* src) {
     StrNCpy(dst, src, len);
     dst[len] = '\0';
     entry->key = dst.begin();
-    entry->value = entry->key;
   }
-  return reinterpret_cast<const char*>(entry->value);
+  entry->value =
+      reinterpret_cast<void*>(reinterpret_cast<size_t>(entry->value) + 1);
+  return reinterpret_cast<const char*>(entry->key);
 }
 
 const char* StringsStorage::GetFormatted(const char* format, ...) {
@@ -52,11 +53,12 @@ const char* StringsStorage::AddOrDisposeString(char* str, int len) {
   if (entry->value == nullptr) {
     // New entry added.
     entry->key = str;
-    entry->value = str;
   } else {
     DeleteArray(str);
   }
-  return reinterpret_cast<const char*>(entry->value);
+  entry->value =
+      reinterpret_cast<void*>(reinterpret_cast<size_t>(entry->value) + 1);
+  return reinterpret_cast<const char*>(entry->key);
 }
 
 const char* StringsStorage::GetVFormatted(const char* format, va_list args) {
@@ -106,6 +108,30 @@ const char* StringsStorage::GetConsName(const char* prefix, Name name) {
   return "";
 }
 
+bool StringsStorage::Release(const char* str) {
+  int len = static_cast<int>(strlen(str));
+  uint32_t hash = StringHasher::HashSequentialString(str, len, kZeroHashSeed);
+  base::HashMap::Entry* entry = names_.Lookup(const_cast<char*>(str), hash);
+  DCHECK(entry);
+  if (!entry) {
+    return false;
+  }
+
+  DCHECK(entry->value);
+  entry->value =
+      reinterpret_cast<void*>(reinterpret_cast<size_t>(entry->value) - 1);
+
+  if (entry->value == 0) {
+    names_.Remove(const_cast<char*>(str), hash);
+    DeleteArray(str);
+  }
+  return true;
+}
+
+size_t StringsStorage::GetStringCountForTesting() const {
+  return names_.occupancy();
+}
+
 base::HashMap::Entry* StringsStorage::GetEntry(const char* str, int len) {
   uint32_t hash = StringHasher::HashSequentialString(str, len, kZeroHashSeed);
   return names_.LookupOrInsert(const_cast<char*>(str), hash);
diff --git a/deps/v8/src/profiler/strings-storage.h b/deps/v8/src/profiler/strings-storage.h
index 650ecac3e6..4948957f83 100644
--- a/deps/v8/src/profiler/strings-storage.h
+++ b/deps/v8/src/profiler/strings-storage.h
@@ -35,6 +35,13 @@ class V8_EXPORT_PRIVATE StringsStorage {
   // Appends string resulting from name to prefix, then returns the stored
   // result.
   const char* GetConsName(const char* prefix, Name name);
+  // Reduces the refcount of the given string, freeing it if no other
+  // references are made to it.
+  // Returns true if the string was successfully unref'd.
+  bool Release(const char* str);
+
+  // Returns the number of strings in the store.
+  size_t GetStringCountForTesting() const;
 
  private:
   static bool StringsMatch(void* key1, void* key2);
diff --git a/deps/v8/src/profiler/tick-sample.cc b/deps/v8/src/profiler/tick-sample.cc
index 6c1b8a9e90..00bff91cd0 100644
--- a/deps/v8/src/profiler/tick-sample.cc
+++ b/deps/v8/src/profiler/tick-sample.cc
@@ -110,7 +110,7 @@ bool SimulatorHelper::FillRegisters(Isolate* isolate,
   }
   state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
   state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
   if (!simulator->has_bad_pc()) {
     state->pc = reinterpret_cast<void*>(simulator->get_pc());
   }
diff --git a/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.cc b/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.cc
index 8f9da563a9..03dac337e0 100644
--- a/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.cc
+++ b/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.cc
@@ -110,6 +110,8 @@ RegExpMacroAssemblerARM::RegExpMacroAssemblerARM(Isolate* isolate, Zone* zone,
       success_label_(),
       backtrack_label_(),
       exit_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);   // We'll write the entry code later.
   __ bind(&start_label_);  // And then continue from here.
@@ -221,9 +223,8 @@ void RegExpMacroAssemblerARM::CheckGreedyLoop(Label* on_equal) {
   BranchOrBacktrack(eq, on_equal);
 }
 
-
 void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ ldr(r0, register_location(start_reg));  // Index of start of capture
   __ ldr(r1, register_location(start_reg + 1));  // Index of end of capture
@@ -315,7 +316,7 @@ void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
     //   r0: Address byte_offset1 - Address captured substring's start.
     //   r1: Address byte_offset2 - Address of current character position.
     //   r2: size_t byte_length - length of capture in bytes(!)
-    //   r3: Isolate* isolate or 0 if unicode flag.
+    //   r3: Isolate* isolate.
 
     // Address of start of capture.
     __ add(r0, r0, Operand(end_of_input_address()));
@@ -329,14 +330,7 @@ void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
       __ sub(r1, r1, r4);
     }
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ mov(r3, Operand(0));
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ mov(r3, Operand(ExternalReference::isolate_address(isolate())));
-    }
+    __ mov(r3, Operand(ExternalReference::isolate_address(isolate())));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -360,7 +354,6 @@ void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerARM::CheckNotBackReference(int start_reg,
                                                     bool read_backward,
                                                     Label* on_no_match) {
diff --git a/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.h b/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.h
index 6320913f4c..22628fb760 100644
--- a/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.h
+++ b/deps/v8/src/regexp/arm/regexp-macro-assembler-arm.h
@@ -37,7 +37,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerARM
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(unsigned c,
diff --git a/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc b/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
index 56658819b1..43a6bdf912 100644
--- a/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
+++ b/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.cc
@@ -120,10 +120,14 @@ RegExpMacroAssemblerARM64::RegExpMacroAssemblerARM64(Isolate* isolate,
       success_label_(),
       backtrack_label_(),
       exit_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
   // We can cache at most 16 W registers in x0-x7.
   STATIC_ASSERT(kNumCachedRegisters <= 16);
   STATIC_ASSERT((kNumCachedRegisters % 2) == 0);
+  __ CallTarget();
+
   __ B(&entry_label_);   // We'll write the entry code later.
   __ Bind(&start_label_);  // And then continue from here.
 }
@@ -212,6 +216,9 @@ void RegExpMacroAssemblerARM64::Bind(Label* label) {
   __ Bind(label);
 }
 
+void RegExpMacroAssemblerARM64::BindJumpTarget(Label* label) {
+  __ BindJumpTarget(label);
+}
 
 void RegExpMacroAssemblerARM64::CheckCharacter(uint32_t c, Label* on_equal) {
   CompareAndBranchOrBacktrack(current_character(), c, eq, on_equal);
@@ -286,9 +293,8 @@ void RegExpMacroAssemblerARM64::CheckGreedyLoop(Label* on_equal) {
   BranchOrBacktrack(eq, on_equal);
 }
 
-
 void RegExpMacroAssemblerARM64::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
 
   Register capture_start_offset = w10;
@@ -402,7 +408,7 @@ void RegExpMacroAssemblerARM64::CheckNotBackReferenceIgnoreCase(
     //   x0: Address byte_offset1 - Address captured substring's start.
     //   x1: Address byte_offset2 - Address of current character position.
     //   w2: size_t byte_length - length of capture in bytes(!)
-    //   x3: Isolate* isolate or 0 if unicode flag
+    //   x3: Isolate* isolate.
 
     // Address of start of capture.
     __ Add(x0, input_end(), Operand(capture_start_offset, SXTW));
@@ -414,14 +420,7 @@ void RegExpMacroAssemblerARM64::CheckNotBackReferenceIgnoreCase(
       __ Sub(x1, x1, Operand(capture_length, SXTW));
     }
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ Mov(x3, Operand(0));
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ Mov(x3, ExternalReference::isolate_address(isolate()));
-    }
+    __ Mov(x3, ExternalReference::isolate_address(isolate()));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -737,10 +736,11 @@ Handle<HeapObject> RegExpMacroAssemblerARM64::GetCode(Handle<String> source) {
   CPURegList argument_registers(x0, x5, x6, x7);
 
   CPURegList registers_to_retain = kCalleeSaved;
-  DCHECK_EQ(11, kCalleeSaved.Count());
+  registers_to_retain.Combine(fp);
   registers_to_retain.Combine(lr);
 
-  __ PushCPURegList(registers_to_retain);
+  DCHECK(registers_to_retain.IncludesAliasOf(lr));
+  __ PushCPURegList<TurboAssembler::kSignLR>(registers_to_retain);
   __ PushCPURegList(argument_registers);
 
   // Set frame pointer in place.
@@ -1035,7 +1035,7 @@ Handle<HeapObject> RegExpMacroAssemblerARM64::GetCode(Handle<String> source) {
   __ Mov(sp, fp);
 
   // Restore registers.
-  __ PopCPURegList(registers_to_retain);
+  __ PopCPURegList<TurboAssembler::kAuthLR>(registers_to_retain);
 
   __ Ret();
 
@@ -1585,14 +1585,14 @@ void RegExpMacroAssemblerARM64::CallIf(Label* to, Condition condition) {
 
 
 void RegExpMacroAssemblerARM64::RestoreLinkRegister() {
-  __ Pop(lr, xzr);
+  __ Pop<TurboAssembler::kAuthLR>(padreg, lr);
   __ Add(lr, lr, Operand(masm_->CodeObject()));
 }
 
 
 void RegExpMacroAssemblerARM64::SaveLinkRegister() {
   __ Sub(lr, lr, Operand(masm_->CodeObject()));
-  __ Push(xzr, lr);
+  __ Push<TurboAssembler::kSignLR>(lr, padreg);
 }
 
 
diff --git a/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.h b/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.h
index cee9e2c97e..91b5e90bf5 100644
--- a/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.h
+++ b/deps/v8/src/regexp/arm64/regexp-macro-assembler-arm64.h
@@ -42,7 +42,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerARM64
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(unsigned c,
@@ -65,6 +65,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerARM64
   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
   virtual bool CheckSpecialCharacterClass(uc16 type,
                                           Label* on_no_match);
+  virtual void BindJumpTarget(Label* label = nullptr);
   virtual void Fail();
   virtual Handle<HeapObject> GetCode(Handle<String> source);
   virtual void GoTo(Label* label);
diff --git a/deps/v8/src/regexp/gen-regexp-special-case.cc b/deps/v8/src/regexp/gen-regexp-special-case.cc
index 8aace6ab88..9606c5d70d 100644
--- a/deps/v8/src/regexp/gen-regexp-special-case.cc
+++ b/deps/v8/src/regexp/gen-regexp-special-case.cc
@@ -1,4 +1,4 @@
-// Copyright 2019 the V8 project authors. All rights reserved.
+// Copyright 2020 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -7,19 +7,19 @@
 #include <iostream>
 #include <sstream>
 
-#include "src/base/logging.h"
-#include "unicode/uchar.h"
-#include "unicode/uniset.h"
+#include "src/regexp/special-case.h"
 
 namespace v8 {
 namespace internal {
 
-// The following code generates BuildSpecialAddSet() and BuildIgnoreSet()
-// functions into "src/regexp/special-case.cc".
-// See more details in http://shorturl.at/adfO5
-void PrintSet(std::ofstream& out, const char* func_name,
+static const uc32 kSurrogateStart = 0xd800;
+static const uc32 kSurrogateEnd = 0xdfff;
+static const uc32 kNonBmpStart = 0x10000;
+
+// The following code generates "src/regexp/special-case.cc".
+void PrintSet(std::ofstream& out, const char* name,
               const icu::UnicodeSet& set) {
-  out << "icu::UnicodeSet " << func_name << "() {\n"
+  out << "icu::UnicodeSet Build" << name << "() {\n"
       << "  icu::UnicodeSet set;\n";
   for (int32_t i = 0; i < set.getRangeCount(); i++) {
     if (set.getRangeStart(i) == set.getRangeEnd(i)) {
@@ -31,73 +31,113 @@ void PrintSet(std::ofstream& out, const char* func_name,
   }
   out << "  set.freeze();\n"
       << "  return set;\n"
-      << "}\n";
+      << "}\n\n";
+
+  out << "struct " << name << "Data {\n"
+      << "  " << name << "Data() : set(Build" << name << "()) {}\n"
+      << "  const icu::UnicodeSet set;\n"
+      << "};\n\n";
+
+  out << "//static\n"
+      << "const icu::UnicodeSet& RegExpCaseFolding::" << name << "() {\n"
+      << "  static base::LazyInstance<" << name << "Data>::type set =\n"
+      << "      LAZY_INSTANCE_INITIALIZER;\n"
+      << "  return set.Pointer()->set;\n"
+      << "}\n\n";
 }
 
 void PrintSpecial(std::ofstream& out) {
   icu::UnicodeSet current;
-  icu::UnicodeSet processed(0xd800, 0xdbff);  // Ignore surrogate range.
   icu::UnicodeSet special_add;
   icu::UnicodeSet ignore;
   UErrorCode status = U_ZERO_ERROR;
   icu::UnicodeSet upper("[\\p{Lu}]", status);
   CHECK(U_SUCCESS(status));
-  // Iterate through all chars in BMP except ASCII and Surrogate.
-  for (UChar32 i = 0x80; i < 0x010000; i++) {
-    // Ignore those characters which is already processed.
-    if (!processed.contains(i)) {
-      current.set(i, i);
-      current.closeOver(USET_CASE_INSENSITIVE);
 
-      // Remember we already processed current.
-      processed.addAll(current);
-
-      // All uppercase characters in current.
-      icu::UnicodeSet keep_upper(current);
-      keep_upper.retainAll(upper);
-
-      // Check if we have more than one uppercase character in current.
-      // If there are more than one uppercase character, then it is a special
-      // set which need to be added into either "Special Add" set or "Ignore"
-      // set.
-      int32_t number_of_upper = 0;
-      for (int32_t i = 0; i < keep_upper.getRangeCount() && i <= 1; i++) {
-        number_of_upper +=
-            keep_upper.getRangeEnd(i) - keep_upper.getRangeStart(i) + 1;
+  // Iterate through all chars in BMP except surrogates.
+  for (UChar32 i = 0; i < kNonBmpStart; i++) {
+    if (i >= kSurrogateStart && i <= kSurrogateEnd) {
+      continue;  // Ignore surrogate range
+    }
+    current.set(i, i);
+    current.closeOver(USET_CASE_INSENSITIVE);
+
+    // Check to see if all characters in the case-folding equivalence
+    // class as defined by UnicodeSet::closeOver all map to the same
+    // canonical value.
+    UChar32 canonical = RegExpCaseFolding::Canonicalize(i);
+    bool class_has_matching_canonical_char = false;
+    bool class_has_non_matching_canonical_char = false;
+    for (int32_t j = 0; j < current.getRangeCount(); j++) {
+      for (UChar32 c = current.getRangeStart(j); c <= current.getRangeEnd(j);
+           c++) {
+        if (c == i) {
+          continue;
+        }
+        UChar32 other_canonical = RegExpCaseFolding::Canonicalize(c);
+        if (canonical == other_canonical) {
+          class_has_matching_canonical_char = true;
+        } else {
+          class_has_non_matching_canonical_char = true;
+        }
+      }
+    }
+    // If any other character in i's equivalence class has a
+    // different canonical value, then i needs special handling.  If
+    // no other character shares a canonical value with i, we can
+    // ignore i when adding alternatives for case-independent
+    // comparison.  If at least one other character shares a
+    // canonical value, then i needs special handling.
+    if (class_has_non_matching_canonical_char) {
+      if (class_has_matching_canonical_char) {
+        special_add.add(i);
+      } else {
+        ignore.add(i);
       }
-      if (number_of_upper > 1) {
-        // Add all non uppercase characters (could be Ll or Mn) to special add
-        // set.
-        current.removeAll(upper);
-        special_add.addAll(current);
-
-        // Add the uppercase characters of non uppercase character to
-        // special add set.
-        CHECK_GT(current.getRangeCount(), 0);
-        UChar32 main_upper = u_toupper(current.getRangeStart(0));
-        special_add.add(main_upper);
-
-        // Add all uppercase except the main upper to ignore set.
-        keep_upper.remove(main_upper);
-        ignore.addAll(keep_upper);
+    }
+  }
+
+  // Verify that no Unicode equivalence class contains two non-trivial
+  // JS equivalence classes. Every character in SpecialAddSet has the
+  // same canonical value as every other non-IgnoreSet character in
+  // its Unicode equivalence class. Therefore, if we call closeOver on
+  // a set containing no IgnoreSet characters, the only characters
+  // that must be removed from the result are in IgnoreSet. This fact
+  // is used in CharacterRange::AddCaseEquivalents.
+  for (int32_t i = 0; i < special_add.getRangeCount(); i++) {
+    for (UChar32 c = special_add.getRangeStart(i);
+         c <= special_add.getRangeEnd(i); c++) {
+      UChar32 canonical = RegExpCaseFolding::Canonicalize(c);
+      current.set(c, c);
+      current.closeOver(USET_CASE_INSENSITIVE);
+      current.removeAll(ignore);
+      for (int32_t j = 0; j < current.getRangeCount(); j++) {
+        for (UChar32 c2 = current.getRangeStart(j);
+             c2 <= current.getRangeEnd(j); c2++) {
+          CHECK_EQ(canonical, RegExpCaseFolding::Canonicalize(c2));
+        }
       }
     }
   }
 
-  // Remove any ASCII
-  special_add.remove(0x0000, 0x007f);
-  PrintSet(out, "BuildIgnoreSet", ignore);
-  PrintSet(out, "BuildSpecialAddSet", special_add);
+  PrintSet(out, "IgnoreSet", ignore);
+  PrintSet(out, "SpecialAddSet", special_add);
 }
 
 void WriteHeader(const char* header_filename) {
   std::ofstream out(header_filename);
   out << std::hex << std::setfill('0') << std::setw(4);
-
-  out << "// Automatically generated by regexp/gen-regexp-special-case.cc\n"
-      << "// The following functions are used to build icu::UnicodeSet\n"
-      << "// for specical cases different between Unicode and ECMA262.\n"
+  out << "// Copyright 2020 the V8 project authors. All rights reserved.\n"
+      << "// Use of this source code is governed by a BSD-style license that\n"
+      << "// can be found in the LICENSE file.\n\n"
+      << "// Automatically generated by regexp/gen-regexp-special-case.cc\n\n"
+      << "// The following functions are used to build UnicodeSets\n"
+      << "// for special cases where the case-folding algorithm used by\n"
+      << "// UnicodeSet::closeOver(USET_CASE_INSENSITIVE) does not match\n"
+      << "// the algorithm defined in ECMAScript 2020 21.2.2.8.2 (Runtime\n"
+      << "// Semantics: Canonicalize) step 3.\n\n"
       << "#ifdef V8_INTL_SUPPORT\n"
+      << "#include \"src/base/lazy-instance.h\"\n\n"
       << "#include \"src/regexp/special-case.h\"\n\n"
       << "#include \"unicode/uniset.h\"\n"
       << "namespace v8 {\n"
diff --git a/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.cc b/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.cc
index f9015287f9..7f6bd5e296 100644
--- a/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.cc
+++ b/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.cc
@@ -205,9 +205,8 @@ void RegExpMacroAssemblerIA32::CheckGreedyLoop(Label* on_equal) {
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ mov(edx, register_location(start_reg));  // Index of start of capture
   __ mov(ebx, register_location(start_reg + 1));  // Index of end of capture
@@ -314,18 +313,11 @@ void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
     //   Address byte_offset1 - Address captured substring's start.
     //   Address byte_offset2 - Address of current character position.
     //   size_t byte_length - length of capture in bytes(!)
-//   Isolate* isolate or 0 if unicode flag.
+    //   Isolate* isolate.
 
     // Set isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ mov(Operand(esp, 3 * kSystemPointerSize), Immediate(0));
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ mov(Operand(esp, 3 * kSystemPointerSize),
-             Immediate(ExternalReference::isolate_address(isolate())));
-    }
+    __ mov(Operand(esp, 3 * kSystemPointerSize),
+           Immediate(ExternalReference::isolate_address(isolate())));
     // Set byte_length.
     __ mov(Operand(esp, 2 * kSystemPointerSize), ebx);
     // Set byte_offset2.
@@ -366,7 +358,6 @@ void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerIA32::CheckNotBackReference(int start_reg,
                                                      bool read_backward,
                                                      Label* on_no_match) {
diff --git a/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.h b/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.h
index b2c6fab7b3..f68dd0b1b7 100644
--- a/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.h
+++ b/deps/v8/src/regexp/ia32/regexp-macro-assembler-ia32.h
@@ -37,7 +37,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerIA32
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(uint32_t c,
diff --git a/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.cc b/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.cc
index 1e7839c219..e3f2ea6292 100644
--- a/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.cc
+++ b/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.cc
@@ -106,6 +106,8 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);   // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
@@ -223,9 +225,8 @@ void RegExpMacroAssemblerMIPS::CheckGreedyLoop(Label* on_equal) {
   BranchOrBacktrack(on_equal, eq, current_input_offset(), Operand(a0));
 }
 
-
 void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ lw(a0, register_location(start_reg));  // Index of start of capture.
   __ lw(a1, register_location(start_reg + 1));  // Index of end of capture.
@@ -320,7 +321,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
     //   a0: Address byte_offset1 - Address captured substring's start.
     //   a1: Address byte_offset2 - Address of current character position.
     //   a2: size_t byte_length - length of capture in bytes(!).
-    //   a3: Isolate* isolate or 0 if unicode flag.
+    //   a3: Isolate* isolate.
 
     // Address of start of capture.
     __ Addu(a0, a0, Operand(end_of_input_address()));
@@ -334,14 +335,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
       __ Subu(a1, a1, Operand(s3));
     }
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ mov(a3, zero_reg);
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
-    }
+    __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -368,7 +362,6 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerMIPS::CheckNotBackReference(int start_reg,
                                                      bool read_backward,
                                                      Label* on_no_match) {
diff --git a/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.h b/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.h
index 9281b0174d..5733bbe046 100644
--- a/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.h
+++ b/deps/v8/src/regexp/mips/regexp-macro-assembler-mips.h
@@ -37,7 +37,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(uint32_t c,
diff --git a/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.cc b/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.cc
index 3dd1548685..fc3cad8b0e 100644
--- a/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.cc
+++ b/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.cc
@@ -142,6 +142,8 @@ RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
   __ jmp(&entry_label_);   // We'll write the entry code later.
   // If the code gets too big or corrupted, an internal exception will be
@@ -259,9 +261,8 @@ void RegExpMacroAssemblerMIPS::CheckGreedyLoop(Label* on_equal) {
   BranchOrBacktrack(on_equal, eq, current_input_offset(), Operand(a0));
 }
 
-
 void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ Ld(a0, register_location(start_reg));      // Index of start of capture.
   __ Ld(a1, register_location(start_reg + 1));  // Index of end of capture.
@@ -356,7 +357,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
     //   a0: Address byte_offset1 - Address captured substring's start.
     //   a1: Address byte_offset2 - Address of current character position.
     //   a2: size_t byte_length - length of capture in bytes(!).
-    //   a3: Isolate* isolate or 0 if unicode flag.
+    //   a3: Isolate* isolate.
 
     // Address of start of capture.
     __ Daddu(a0, a0, Operand(end_of_input_address()));
@@ -370,14 +371,7 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
       __ Dsubu(a1, a1, Operand(s3));
     }
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ mov(a3, zero_reg);
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
-    }
+    __ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -404,7 +398,6 @@ void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerMIPS::CheckNotBackReference(int start_reg,
                                                      bool read_backward,
                                                      Label* on_no_match) {
diff --git a/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.h b/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.h
index bc7f83e6e9..b267297c24 100644
--- a/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.h
+++ b/deps/v8/src/regexp/mips64/regexp-macro-assembler-mips64.h
@@ -37,7 +37,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerMIPS
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(uint32_t c,
diff --git a/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc b/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
index 50bf71e6d5..376103324a 100644
--- a/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
+++ b/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#if V8_TARGET_ARCH_PPC
+#if V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 
 #include "src/regexp/ppc/regexp-macro-assembler-ppc.h"
 
@@ -111,6 +111,8 @@ RegExpMacroAssemblerPPC::RegExpMacroAssemblerPPC(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
 
 
@@ -123,7 +125,6 @@ RegExpMacroAssemblerPPC::RegExpMacroAssemblerPPC(Isolate* isolate, Zone* zone,
   __ bind(&start_label_);  // And then continue from here.
 }
 
-
 RegExpMacroAssemblerPPC::~RegExpMacroAssemblerPPC() {
   delete masm_;
   // Unuse labels in case we throw away the assembler without calling GetCode.
@@ -241,7 +242,7 @@ void RegExpMacroAssemblerPPC::CheckGreedyLoop(Label* on_equal) {
 }
 
 void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ LoadP(r3, register_location(start_reg), r0);  // Index of start of capture
   __ LoadP(r4, register_location(start_reg + 1), r0);  // Index of end
@@ -336,7 +337,7 @@ void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
     //   r3: Address byte_offset1 - Address captured substring's start.
     //   r4: Address byte_offset2 - Address of current character position.
     //   r5: size_t byte_length - length of capture in bytes(!)
-    //   r6: Isolate* isolate or 0 if unicode flag.
+    //   r6: Isolate* isolate.
 
     // Address of start of capture.
     __ add(r3, r3, end_of_input_address());
@@ -350,14 +351,7 @@ void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
       __ sub(r4, r4, r25);
     }
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ li(r6, Operand::Zero());
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ mov(r6, Operand(ExternalReference::isolate_address(isolate())));
-    }
+    __ mov(r6, Operand(ExternalReference::isolate_address(isolate())));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
@@ -381,7 +375,6 @@ void RegExpMacroAssemblerPPC::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerPPC::CheckNotBackReference(int start_reg,
                                                     bool read_backward,
                                                     Label* on_no_match) {
@@ -1371,4 +1364,4 @@ void RegExpMacroAssemblerPPC::LoadCurrentCharacterUnchecked(int cp_offset,
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_TARGET_ARCH_PPC
+#endif  //  V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
diff --git a/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.h b/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.h
index c726a5f0d7..3e64f139a8 100644
--- a/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.h
+++ b/deps/v8/src/regexp/ppc/regexp-macro-assembler-ppc.h
@@ -36,7 +36,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerPPC
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(unsigned c, unsigned mask,
diff --git a/deps/v8/src/regexp/regexp-ast.h b/deps/v8/src/regexp/regexp-ast.h
index 3de29512ea..a9106d3d30 100644
--- a/deps/v8/src/regexp/regexp-ast.h
+++ b/deps/v8/src/regexp/regexp-ast.h
@@ -463,7 +463,11 @@ class RegExpQuantifier final : public RegExpTree {
 class RegExpCapture final : public RegExpTree {
  public:
   explicit RegExpCapture(int index)
-      : body_(nullptr), index_(index), name_(nullptr) {}
+      : body_(nullptr),
+        index_(index),
+        min_match_(0),
+        max_match_(0),
+        name_(nullptr) {}
   void* Accept(RegExpVisitor* visitor, void* data) override;
   RegExpNode* ToNode(RegExpCompiler* compiler, RegExpNode* on_success) override;
   static RegExpNode* ToNode(RegExpTree* body, int index,
@@ -473,10 +477,14 @@ class RegExpCapture final : public RegExpTree {
   bool IsAnchoredAtEnd() override;
   Interval CaptureRegisters() override;
   bool IsCapture() override;
-  int min_match() override { return body_->min_match(); }
-  int max_match() override { return body_->max_match(); }
+  int min_match() override { return min_match_; }
+  int max_match() override { return max_match_; }
   RegExpTree* body() { return body_; }
-  void set_body(RegExpTree* body) { body_ = body; }
+  void set_body(RegExpTree* body) {
+    body_ = body;
+    min_match_ = body->min_match();
+    max_match_ = body->max_match();
+  }
   int index() const { return index_; }
   const ZoneVector<uc16>* name() const { return name_; }
   void set_name(const ZoneVector<uc16>* name) { name_ = name; }
@@ -486,12 +494,17 @@ class RegExpCapture final : public RegExpTree {
  private:
   RegExpTree* body_;
   int index_;
+  int min_match_;
+  int max_match_;
   const ZoneVector<uc16>* name_;
 };
 
 class RegExpGroup final : public RegExpTree {
  public:
-  explicit RegExpGroup(RegExpTree* body) : body_(body) {}
+  explicit RegExpGroup(RegExpTree* body)
+      : body_(body),
+        min_match_(body->min_match()),
+        max_match_(body->max_match()) {}
   void* Accept(RegExpVisitor* visitor, void* data) override;
   RegExpNode* ToNode(RegExpCompiler* compiler,
                      RegExpNode* on_success) override {
@@ -501,13 +514,15 @@ class RegExpGroup final : public RegExpTree {
   bool IsAnchoredAtStart() override { return body_->IsAnchoredAtStart(); }
   bool IsAnchoredAtEnd() override { return body_->IsAnchoredAtEnd(); }
   bool IsGroup() override;
-  int min_match() override { return body_->min_match(); }
-  int max_match() override { return body_->max_match(); }
+  int min_match() override { return min_match_; }
+  int max_match() override { return max_match_; }
   Interval CaptureRegisters() override { return body_->CaptureRegisters(); }
   RegExpTree* body() { return body_; }
 
  private:
   RegExpTree* body_;
+  int min_match_;
+  int max_match_;
 };
 
 class RegExpLookaround final : public RegExpTree {
diff --git a/deps/v8/src/regexp/regexp-bytecode-generator.cc b/deps/v8/src/regexp/regexp-bytecode-generator.cc
index 0dcc288d3c..e82b67b530 100644
--- a/deps/v8/src/regexp/regexp-bytecode-generator.cc
+++ b/deps/v8/src/regexp/regexp-bytecode-generator.cc
@@ -329,13 +329,11 @@ void RegExpBytecodeGenerator::CheckNotBackReference(int start_reg,
 }
 
 void RegExpBytecodeGenerator::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_not_equal) {
+    int start_reg, bool read_backward, Label* on_not_equal) {
   DCHECK_LE(0, start_reg);
   DCHECK_GE(kMaxRegister, start_reg);
-  Emit(read_backward ? (unicode ? BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD
-                                : BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD)
-                     : (unicode ? BC_CHECK_NOT_BACK_REF_NO_CASE_UNICODE
-                                : BC_CHECK_NOT_BACK_REF_NO_CASE),
+  Emit(read_backward ? BC_CHECK_NOT_BACK_REF_NO_CASE_BACKWARD
+                     : BC_CHECK_NOT_BACK_REF_NO_CASE,
        start_reg);
   EmitOrLink(on_not_equal);
 }
diff --git a/deps/v8/src/regexp/regexp-bytecode-generator.h b/deps/v8/src/regexp/regexp-bytecode-generator.h
index dfcc2ca5f8..85073cc99d 100644
--- a/deps/v8/src/regexp/regexp-bytecode-generator.h
+++ b/deps/v8/src/regexp/regexp-bytecode-generator.h
@@ -69,7 +69,7 @@ class V8_EXPORT_PRIVATE RegExpBytecodeGenerator : public RegExpMacroAssembler {
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void IfRegisterLT(int register_index, int comparand, Label* if_lt);
   virtual void IfRegisterGE(int register_index, int comparand, Label* if_ge);
diff --git a/deps/v8/src/regexp/regexp-bytecode-peephole.cc b/deps/v8/src/regexp/regexp-bytecode-peephole.cc
index 8f1f1d95a9..f0957f0779 100644
--- a/deps/v8/src/regexp/regexp-bytecode-peephole.cc
+++ b/deps/v8/src/regexp/regexp-bytecode-peephole.cc
@@ -436,7 +436,6 @@ BytecodeArgumentMapping BytecodeSequenceNode::ArgumentMapping(
     size_t index) const {
   DCHECK(IsSequence());
   DCHECK(argument_mapping_ != nullptr);
-  DCHECK_GE(index, 0);
   DCHECK_LT(index, argument_mapping_->size());
 
   return argument_mapping_->at(index);
diff --git a/deps/v8/src/regexp/regexp-bytecodes.h b/deps/v8/src/regexp/regexp-bytecodes.h
index e25945d0a0..1664a476d2 100644
--- a/deps/v8/src/regexp/regexp-bytecodes.h
+++ b/deps/v8/src/regexp/regexp-bytecodes.h
@@ -101,12 +101,12 @@ STATIC_ASSERT(1 << BYTECODE_SHIFT > BYTECODE_MASK);
   V(CHECK_BIT_IN_TABLE, 34, 24) /* bc8 pad24 addr32 bits128           */       \
   V(CHECK_LT, 35, 8) /* bc8 pad8 uc16 addr32                       */          \
   V(CHECK_GT, 36, 8) /* bc8 pad8 uc16 addr32                       */          \
-  V(CHECK_NOT_BACK_REF, 37, 8)         /* bc8 reg_idx24 addr32 */              \
-  V(CHECK_NOT_BACK_REF_NO_CASE, 38, 8) /* bc8 reg_idx24 addr32 */              \
-  V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE, 39, 8)                                 \
+  V(CHECK_NOT_BACK_REF, 37, 8)                  /* bc8 reg_idx24 addr32 */     \
+  V(CHECK_NOT_BACK_REF_NO_CASE, 38, 8)          /* bc8 reg_idx24 addr32 */     \
+  V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE, 39, 8)  /* UNUSED */                   \
   V(CHECK_NOT_BACK_REF_BACKWARD, 40, 8)         /* bc8 reg_idx24 addr32 */     \
   V(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD, 41, 8) /* bc8 reg_idx24 addr32 */     \
-  V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD, 42, 8)                        \
+  V(CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD, 42, 8) /* UNUSED */           \
   V(CHECK_NOT_REGS_EQUAL, 43, 12) /* bc8 regidx24 reg_idx32 addr32 */          \
   V(CHECK_REGISTER_LT, 44, 12)    /* bc8 reg_idx24 value32 addr32 */           \
   V(CHECK_REGISTER_GE, 45, 12)    /* bc8 reg_idx24 value32 addr32 */           \
diff --git a/deps/v8/src/regexp/regexp-compiler-tonode.cc b/deps/v8/src/regexp/regexp-compiler-tonode.cc
index 2d86d3ea9e..40ecee0f91 100644
--- a/deps/v8/src/regexp/regexp-compiler-tonode.cc
+++ b/deps/v8/src/regexp/regexp-compiler-tonode.cc
@@ -1140,39 +1140,6 @@ Vector<const int> CharacterRange::GetWordBounds() {
   return Vector<const int>(kWordRanges, kWordRangeCount - 1);
 }
 
-#ifdef V8_INTL_SUPPORT
-struct IgnoreSet {
-  IgnoreSet() : set(BuildIgnoreSet()) {}
-  const icu::UnicodeSet set;
-};
-
-struct SpecialAddSet {
-  SpecialAddSet() : set(BuildSpecialAddSet()) {}
-  const icu::UnicodeSet set;
-};
-
-icu::UnicodeSet BuildAsciiAToZSet() {
-  icu::UnicodeSet set('a', 'z');
-  set.add('A', 'Z');
-  set.freeze();
-  return set;
-}
-
-struct AsciiAToZSet {
-  AsciiAToZSet() : set(BuildAsciiAToZSet()) {}
-  const icu::UnicodeSet set;
-};
-
-static base::LazyInstance<IgnoreSet>::type ignore_set =
-    LAZY_INSTANCE_INITIALIZER;
-
-static base::LazyInstance<SpecialAddSet>::type special_add_set =
-    LAZY_INSTANCE_INITIALIZER;
-
-static base::LazyInstance<AsciiAToZSet>::type ascii_a_to_z_set =
-    LAZY_INSTANCE_INITIALIZER;
-#endif  // V8_INTL_SUPPORT
-
 // static
 void CharacterRange::AddCaseEquivalents(Isolate* isolate, Zone* zone,
                                         ZoneList<CharacterRange>* ranges,
@@ -1195,75 +1162,22 @@ void CharacterRange::AddCaseEquivalents(Isolate* isolate, Zone* zone,
     others.add(from, to);
   }
 
-  // Set of characters already added to ranges that do not need to be added
-  // again.
+  // Compute the set of additional characters that should be added,
+  // using UnicodeSet::closeOver. ECMA 262 defines slightly different
+  // case-folding rules than Unicode, so some characters that are
+  // added by closeOver do not match anything other than themselves in
+  // JS. For example, 'ſ' (U+017F LATIN SMALL LETTER LONG S) is the
+  // same case-insensitive character as 's' or 'S' according to
+  // Unicode, but does not match any other character in JS. To handle
+  // this case, we add such characters to the IgnoreSet and filter
+  // them out. We filter twice: once before calling closeOver (to
+  // prevent 'ſ' from adding 's'), and once after calling closeOver
+  // (to prevent 's' from adding 'ſ'). See regexp/special-case.h for
+  // more information.
   icu::UnicodeSet already_added(others);
-
-  // Set of characters in ranges that are in the 52 ASCII characters [a-zA-Z].
-  icu::UnicodeSet in_ascii_a_to_z(others);
-  in_ascii_a_to_z.retainAll(ascii_a_to_z_set.Pointer()->set);
-
-  // Remove all chars in [a-zA-Z] from others.
-  others.removeAll(in_ascii_a_to_z);
-
-  // Set of characters in ranges that are overlapping with special add set.
-  icu::UnicodeSet in_special_add(others);
-  in_special_add.retainAll(special_add_set.Pointer()->set);
-
-  others.removeAll(in_special_add);
-
-  // Ignore all chars in ignore set.
-  others.removeAll(ignore_set.Pointer()->set);
-
-  // For most of the chars in ranges that is still in others, find the case
-  // equivlant set by calling closeOver(USET_CASE_INSENSITIVE).
+  others.removeAll(RegExpCaseFolding::IgnoreSet());
   others.closeOver(USET_CASE_INSENSITIVE);
-
-  // Because closeOver(USET_CASE_INSENSITIVE) may add ASCII [a-zA-Z] to others,
-  // but ECMA262 "i" mode won't consider that, remove them from others.
-  // Ex: U+017F add 'S' and 's' to others.
-  others.removeAll(ascii_a_to_z_set.Pointer()->set);
-
-  // Special handling for in_ascii_a_to_z.
-  for (int32_t i = 0; i < in_ascii_a_to_z.getRangeCount(); i++) {
-    UChar32 start = in_ascii_a_to_z.getRangeStart(i);
-    UChar32 end = in_ascii_a_to_z.getRangeEnd(i);
-    // Check if it is uppercase A-Z by checking bit 6.
-    if (start & 0x0020) {
-      // Add the lowercases
-      others.add(start & 0x005F, end & 0x005F);
-    } else {
-      // Add the uppercases
-      others.add(start | 0x0020, end | 0x0020);
-    }
-  }
-
-  // Special handling for chars in "Special Add" set.
-  for (int32_t i = 0; i < in_special_add.getRangeCount(); i++) {
-    UChar32 end = in_special_add.getRangeEnd(i);
-    for (UChar32 ch = in_special_add.getRangeStart(i); ch <= end; ch++) {
-      // Add the uppercase of this character if itself is not an uppercase
-      // character.
-      // Note: The if condiction cannot be u_islower(ch) because ch could be
-      // neither uppercase nor lowercase but Mn.
-      if (!u_isupper(ch)) {
-        others.add(u_toupper(ch));
-      }
-      icu::UnicodeSet candidates(ch, ch);
-      candidates.closeOver(USET_CASE_INSENSITIVE);
-      for (int32_t j = 0; j < candidates.getRangeCount(); j++) {
-        UChar32 end2 = candidates.getRangeEnd(j);
-        for (UChar32 ch2 = candidates.getRangeStart(j); ch2 <= end2; ch2++) {
-          // Add character that is not uppercase to others.
-          if (!u_isupper(ch2)) {
-            others.add(ch2);
-          }
-        }
-      }
-    }
-  }
-
-  // Remove all characters which already in the ranges.
+  others.removeAll(RegExpCaseFolding::IgnoreSet());
   others.removeAll(already_added);
 
   // Add others to the ranges
diff --git a/deps/v8/src/regexp/regexp-compiler.cc b/deps/v8/src/regexp/regexp-compiler.cc
index d141f3c490..a6c7cdbe2f 100644
--- a/deps/v8/src/regexp/regexp-compiler.cc
+++ b/deps/v8/src/regexp/regexp-compiler.cc
@@ -8,7 +8,9 @@
 #include "src/execution/isolate.h"
 #include "src/objects/objects-inl.h"
 #include "src/regexp/regexp-macro-assembler-arch.h"
-#include "src/regexp/regexp-macro-assembler-tracer.h"
+#ifdef V8_INTL_SUPPORT
+#include "src/regexp/special-case.h"
+#endif  // V8_INTL_SUPPORT
 #include "src/strings/unicode-inl.h"
 #include "src/zone/zone-list-inl.h"
 
@@ -242,20 +244,15 @@ RegExpCompiler::RegExpCompiler(Isolate* isolate, Zone* zone, int capture_count,
 RegExpCompiler::CompilationResult RegExpCompiler::Assemble(
     Isolate* isolate, RegExpMacroAssembler* macro_assembler, RegExpNode* start,
     int capture_count, Handle<String> pattern) {
-#ifdef DEBUG
-  if (FLAG_trace_regexp_assembler)
-    macro_assembler_ = new RegExpMacroAssemblerTracer(isolate, macro_assembler);
-  else
-#endif
-    macro_assembler_ = macro_assembler;
+  macro_assembler_ = macro_assembler;
 
-  std::vector<RegExpNode*> work_list;
+  ZoneVector<RegExpNode*> work_list(zone());
   work_list_ = &work_list;
   Label fail;
   macro_assembler_->PushBacktrack(&fail);
   Trace new_trace;
   start->Emit(this, &new_trace);
-  macro_assembler_->Bind(&fail);
+  macro_assembler_->BindJumpTarget(&fail);
   macro_assembler_->Fail();
   while (!work_list.empty()) {
     RegExpNode* node = work_list.back();
@@ -269,14 +266,9 @@ RegExpCompiler::CompilationResult RegExpCompiler::Assemble(
   }
 
   Handle<HeapObject> code = macro_assembler_->GetCode(pattern);
-  isolate->IncreaseTotalRegexpCodeGenerated(code->Size());
+  isolate->IncreaseTotalRegexpCodeGenerated(code);
   work_list_ = nullptr;
 
-#ifdef DEBUG
-  if (FLAG_trace_regexp_assembler) {
-    delete macro_assembler_;
-  }
-#endif
   return {*code, next_register_};
 }
 
@@ -562,7 +554,7 @@ void Trace::Flush(RegExpCompiler* compiler, RegExpNode* successor) {
   }
 
   // On backtrack we need to restore state.
-  assembler->Bind(&undo);
+  assembler->BindJumpTarget(&undo);
   RestoreAffectedRegisters(assembler, max_register, registers_to_pop,
                            registers_to_clear);
   if (backtrack() == nullptr) {
@@ -725,32 +717,34 @@ static int GetCaseIndependentLetters(Isolate* isolate, uc16 character,
                                      unibrow::uchar* letters,
                                      int letter_length) {
 #ifdef V8_INTL_SUPPORT
-  // Special case for U+017F which has upper case in ASCII range.
-  if (character == 0x017f) {
+  if (RegExpCaseFolding::IgnoreSet().contains(character)) {
     letters[0] = character;
     return 1;
   }
+  bool in_special_add_set =
+      RegExpCaseFolding::SpecialAddSet().contains(character);
+
   icu::UnicodeSet set;
   set.add(character);
   set = set.closeOver(USET_CASE_INSENSITIVE);
+
+  UChar32 canon = 0;
+  if (in_special_add_set) {
+    canon = RegExpCaseFolding::Canonicalize(character);
+  }
+
   int32_t range_count = set.getRangeCount();
   int items = 0;
   for (int32_t i = 0; i < range_count; i++) {
     UChar32 start = set.getRangeStart(i);
     UChar32 end = set.getRangeEnd(i);
     CHECK(end - start + items <= letter_length);
-    // Only add to the output if character is not in ASCII range
-    // or the case equivalent character is in ASCII range.
-    // #sec-runtime-semantics-canonicalize-ch
-    // 3.g If the numeric value of ch ≥ 128 and the numeric value of cu < 128,
-    //     return ch.
-    if (!((start >= 128) && (character < 128))) {
-      // No range have start and end span across code point 128.
-      DCHECK((start >= 128) == (end >= 128));
-      for (UChar32 cu = start; cu <= end; cu++) {
-        if (one_byte_subject && cu > String::kMaxOneByteCharCode) break;
-        letters[items++] = (unibrow::uchar)(cu);
+    for (UChar32 cu = start; cu <= end; cu++) {
+      if (one_byte_subject && cu > String::kMaxOneByteCharCode) break;
+      if (in_special_add_set && RegExpCaseFolding::Canonicalize(cu) != canon) {
+        continue;
       }
+      letters[items++] = (unibrow::uchar)(cu);
     }
   }
   return items;
@@ -857,10 +851,6 @@ static bool ShortCutEmitCharacterPair(RegExpMacroAssembler* macro_assembler,
   return false;
 }
 
-using EmitCharacterFunction = bool(Isolate* isolate, RegExpCompiler* compiler,
-                                   uc16 c, Label* on_failure, int cp_offset,
-                                   bool check, bool preloaded);
-
 // Only emits letters (things that have case).  Only used for case independent
 // matches.
 static inline bool EmitAtomLetter(Isolate* isolate, RegExpCompiler* compiler,
@@ -1848,13 +1838,13 @@ RegExpNode* TextNode::FilterOneByte(int depth) {
     if (elm.text_type() == TextElement::ATOM) {
       Vector<const uc16> quarks = elm.atom()->data();
       for (int j = 0; j < quarks.length(); j++) {
-        uint16_t c = quarks[j];
+        uc16 c = quarks[j];
         if (elm.atom()->ignore_case()) {
           c = unibrow::Latin1::TryConvertToLatin1(c);
         }
         if (c > unibrow::Latin1::kMaxChar) return set_replacement(nullptr);
         // Replace quark in case we converted to Latin-1.
-        uint16_t* writable_quarks = const_cast<uint16_t*>(quarks.begin());
+        uc16* writable_quarks = const_cast<uc16*>(quarks.begin());
         writable_quarks[j] = c;
       }
     } else {
@@ -2309,7 +2299,6 @@ void TextNode::TextEmitPass(RegExpCompiler* compiler, TextEmitPassType pass,
       for (int j = preloaded ? 0 : quarks.length() - 1; j >= 0; j--) {
         if (first_element_checked && i == 0 && j == 0) continue;
         if (DeterminedAlready(quick_check, elm.cp_offset() + j)) continue;
-        EmitCharacterFunction* emit_function = nullptr;
         uc16 quark = quarks[j];
         if (elm.atom()->ignore_case()) {
           // Everywhere else we assume that a non-Latin-1 character cannot match
@@ -2317,6 +2306,9 @@ void TextNode::TextEmitPass(RegExpCompiler* compiler, TextEmitPassType pass,
           // invalid by using the Latin1 equivalent instead.
           quark = unibrow::Latin1::TryConvertToLatin1(quark);
         }
+        bool needs_bounds_check =
+            *checked_up_to < cp_offset + j || read_backward();
+        bool bounds_checked = false;
         switch (pass) {
           case NON_LATIN1_MATCH:
             DCHECK(one_byte);
@@ -2326,24 +2318,24 @@ void TextNode::TextEmitPass(RegExpCompiler* compiler, TextEmitPassType pass,
             }
             break;
           case NON_LETTER_CHARACTER_MATCH:
-            emit_function = &EmitAtomNonLetter;
+            bounds_checked =
+                EmitAtomNonLetter(isolate, compiler, quark, backtrack,
+                                  cp_offset + j, needs_bounds_check, preloaded);
             break;
           case SIMPLE_CHARACTER_MATCH:
-            emit_function = &EmitSimpleCharacter;
+            bounds_checked = EmitSimpleCharacter(isolate, compiler, quark,
+                                                 backtrack, cp_offset + j,
+                                                 needs_bounds_check, preloaded);
             break;
           case CASE_CHARACTER_MATCH:
-            emit_function = &EmitAtomLetter;
+            bounds_checked =
+                EmitAtomLetter(isolate, compiler, quark, backtrack,
+                               cp_offset + j, needs_bounds_check, preloaded);
             break;
           default:
             break;
         }
-        if (emit_function != nullptr) {
-          bool bounds_check = *checked_up_to < cp_offset + j || read_backward();
-          bool bound_checked =
-              emit_function(isolate, compiler, quark, backtrack, cp_offset + j,
-                            bounds_check, preloaded);
-          if (bound_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to);
-        }
+        if (bounds_checked) UpdateBoundsCheck(cp_offset + j, checked_up_to);
       }
     } else {
       DCHECK_EQ(TextElement::CHAR_CLASS, elm.text_type());
@@ -3429,8 +3421,8 @@ void BackReferenceNode::Emit(RegExpCompiler* compiler, Trace* trace) {
 
   DCHECK_EQ(start_reg_ + 1, end_reg_);
   if (IgnoreCase(flags_)) {
-    assembler->CheckNotBackReferenceIgnoreCase(
-        start_reg_, read_backward(), IsUnicode(flags_), trace->backtrack());
+    assembler->CheckNotBackReferenceIgnoreCase(start_reg_, read_backward(),
+                                               trace->backtrack());
   } else {
     assembler->CheckNotBackReference(start_reg_, read_backward(),
                                      trace->backtrack());
@@ -3602,12 +3594,17 @@ template <typename... Propagators>
 class Analysis : public NodeVisitor {
  public:
   Analysis(Isolate* isolate, bool is_one_byte)
-      : isolate_(isolate), is_one_byte_(is_one_byte), error_message_(nullptr) {}
+      : isolate_(isolate),
+        is_one_byte_(is_one_byte),
+        error_(RegExpError::kNone) {}
 
   void EnsureAnalyzed(RegExpNode* that) {
     StackLimitCheck check(isolate());
     if (check.HasOverflowed()) {
-      fail("Stack overflow");
+      if (FLAG_correctness_fuzzer_suppressions) {
+        FATAL("Analysis: Aborting on stack overflow");
+      }
+      fail(RegExpError::kAnalysisStackOverflow);
       return;
     }
     if (that->info()->been_analyzed || that->info()->being_analyzed) return;
@@ -3617,12 +3614,12 @@ class Analysis : public NodeVisitor {
     that->info()->been_analyzed = true;
   }
 
-  bool has_failed() { return error_message_ != nullptr; }
-  const char* error_message() {
-    DCHECK(error_message_ != nullptr);
-    return error_message_;
+  bool has_failed() { return error_ != RegExpError::kNone; }
+  RegExpError error() {
+    DCHECK(error_ != RegExpError::kNone);
+    return error_;
   }
-  void fail(const char* error_message) { error_message_ = error_message; }
+  void fail(RegExpError error) { error_ = error; }
 
   Isolate* isolate() const { return isolate_; }
 
@@ -3707,19 +3704,19 @@ class Analysis : public NodeVisitor {
  private:
   Isolate* isolate_;
   bool is_one_byte_;
-  const char* error_message_;
+  RegExpError error_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Analysis);
 };
 
-const char* AnalyzeRegExp(Isolate* isolate, bool is_one_byte,
+RegExpError AnalyzeRegExp(Isolate* isolate, bool is_one_byte,
                           RegExpNode* node) {
   Analysis<AssertionPropagator, EatsAtLeastPropagator> analysis(isolate,
                                                                 is_one_byte);
   DCHECK_EQ(node->info()->been_analyzed, false);
   analysis.EnsureAnalyzed(node);
-  DCHECK_IMPLIES(analysis.has_failed(), analysis.error_message() != nullptr);
-  return analysis.has_failed() ? analysis.error_message() : nullptr;
+  DCHECK_IMPLIES(analysis.has_failed(), analysis.error() != RegExpError::kNone);
+  return analysis.has_failed() ? analysis.error() : RegExpError::kNone;
 }
 
 void BackReferenceNode::FillInBMInfo(Isolate* isolate, int offset, int budget,
diff --git a/deps/v8/src/regexp/regexp-compiler.h b/deps/v8/src/regexp/regexp-compiler.h
index 2de221f35d..d083d5d9dd 100644
--- a/deps/v8/src/regexp/regexp-compiler.h
+++ b/deps/v8/src/regexp/regexp-compiler.h
@@ -423,10 +423,7 @@ struct PreloadState {
 // Analysis performs assertion propagation and computes eats_at_least_ values.
 // See the comments on AssertionPropagator and EatsAtLeastPropagator for more
 // details.
-//
-// This method returns nullptr on success or a null-terminated failure message
-// on failure.
-const char* AnalyzeRegExp(Isolate* isolate, bool is_one_byte, RegExpNode* node);
+RegExpError AnalyzeRegExp(Isolate* isolate, bool is_one_byte, RegExpNode* node);
 
 class FrequencyCollator {
  public:
@@ -503,18 +500,17 @@ class RegExpCompiler {
   }
 
   struct CompilationResult final {
-    explicit CompilationResult(const char* error_message)
-        : error_message(error_message) {}
+    explicit CompilationResult(RegExpError err) : error(err) {}
     CompilationResult(Object code, int registers)
         : code(code), num_registers(registers) {}
 
     static CompilationResult RegExpTooBig() {
-      return CompilationResult("RegExp too big");
+      return CompilationResult(RegExpError::kTooLarge);
     }
 
-    bool Succeeded() const { return error_message == nullptr; }
+    bool Succeeded() const { return error == RegExpError::kNone; }
 
-    const char* const error_message = nullptr;
+    const RegExpError error = RegExpError::kNone;
     Object code;
     int num_registers = 0;
   };
@@ -576,7 +572,7 @@ class RegExpCompiler {
   int next_register_;
   int unicode_lookaround_stack_register_;
   int unicode_lookaround_position_register_;
-  std::vector<RegExpNode*>* work_list_;
+  ZoneVector<RegExpNode*>* work_list_;
   int recursion_depth_;
   RegExpMacroAssembler* macro_assembler_;
   bool one_byte_;
diff --git a/deps/v8/src/regexp/regexp-error.cc b/deps/v8/src/regexp/regexp-error.cc
new file mode 100644
index 0000000000..d7763c64f8
--- /dev/null
+++ b/deps/v8/src/regexp/regexp-error.cc
@@ -0,0 +1,22 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/regexp/regexp-error.h"
+
+namespace v8 {
+namespace internal {
+
+const char* const kRegExpErrorStrings[] = {
+#define TEMPLATE(NAME, STRING) STRING,
+    REGEXP_ERROR_MESSAGES(TEMPLATE)
+#undef TEMPLATE
+};
+
+const char* RegExpErrorString(RegExpError error) {
+  DCHECK_LT(error, RegExpError::NumErrors);
+  return kRegExpErrorStrings[static_cast<int>(error)];
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/regexp/regexp-error.h b/deps/v8/src/regexp/regexp-error.h
new file mode 100644
index 0000000000..6145b404ab
--- /dev/null
+++ b/deps/v8/src/regexp/regexp-error.h
@@ -0,0 +1,58 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_REGEXP_REGEXP_ERROR_H_
+#define V8_REGEXP_REGEXP_ERROR_H_
+
+#include "src/base/logging.h"
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace internal {
+
+#define REGEXP_ERROR_MESSAGES(T)                                          \
+  T(None, "")                                                             \
+  T(StackOverflow, "Maximum call stack size exceeded")                    \
+  T(AnalysisStackOverflow, "Stack overflow")                              \
+  T(TooLarge, "Regular expression too large")                             \
+  T(UnterminatedGroup, "Unterminated group")                              \
+  T(UnmatchedParen, "Unmatched ')'")                                      \
+  T(EscapeAtEndOfPattern, "\\ at end of pattern")                         \
+  T(InvalidPropertyName, "Invalid property name")                         \
+  T(InvalidEscape, "Invalid escape")                                      \
+  T(InvalidDecimalEscape, "Invalid decimal escape")                       \
+  T(InvalidUnicodeEscape, "Invalid Unicode escape")                       \
+  T(NothingToRepeat, "Nothing to repeat")                                 \
+  T(LoneQuantifierBrackets, "Lone quantifier brackets")                   \
+  T(RangeOutOfOrder, "numbers out of order in {} quantifier")             \
+  T(IncompleteQuantifier, "Incomplete quantifier")                        \
+  T(InvalidQuantifier, "Invalid quantifier")                              \
+  T(InvalidGroup, "Invalid group")                                        \
+  T(MultipleFlagDashes, "Multiple dashes in flag group")                  \
+  T(RepeatedFlag, "Repeated flag in flag group")                          \
+  T(InvalidFlagGroup, "Invalid flag group")                               \
+  T(TooManyCaptures, "Too many captures")                                 \
+  T(InvalidCaptureGroupName, "Invalid capture group name")                \
+  T(DuplicateCaptureGroupName, "Duplicate capture group name")            \
+  T(InvalidNamedReference, "Invalid named reference")                     \
+  T(InvalidNamedCaptureReference, "Invalid named capture referenced")     \
+  T(InvalidClassEscape, "Invalid class escape")                           \
+  T(InvalidClassPropertyName, "Invalid property name in character class") \
+  T(InvalidCharacterClass, "Invalid character class")                     \
+  T(UnterminatedCharacterClass, "Unterminated character class")           \
+  T(OutOfOrderCharacterClass, "Range out of order in character class")
+
+enum class RegExpError : uint32_t {
+#define TEMPLATE(NAME, STRING) k##NAME,
+  REGEXP_ERROR_MESSAGES(TEMPLATE)
+#undef TEMPLATE
+      NumErrors
+};
+
+V8_EXPORT_PRIVATE const char* RegExpErrorString(RegExpError error);
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_REGEXP_REGEXP_ERROR_H_
diff --git a/deps/v8/src/regexp/regexp-interpreter.cc b/deps/v8/src/regexp/regexp-interpreter.cc
index a74df90c1d..d3efa65bf1 100644
--- a/deps/v8/src/regexp/regexp-interpreter.cc
+++ b/deps/v8/src/regexp/regexp-interpreter.cc
@@ -35,18 +35,18 @@ namespace internal {
 namespace {
 
 bool BackRefMatchesNoCase(Isolate* isolate, int from, int current, int len,
-                          Vector<const uc16> subject, bool unicode) {
+                          Vector<const uc16> subject) {
   Address offset_a =
       reinterpret_cast<Address>(const_cast<uc16*>(&subject.at(from)));
   Address offset_b =
       reinterpret_cast<Address>(const_cast<uc16*>(&subject.at(current)));
   size_t length = len * kUC16Size;
-  return RegExpMacroAssembler::CaseInsensitiveCompareUC16(
-             offset_a, offset_b, length, unicode ? nullptr : isolate) == 1;
+  return RegExpMacroAssembler::CaseInsensitiveCompareUC16(offset_a, offset_b,
+                                                          length, isolate) == 1;
 }
 
 bool BackRefMatchesNoCase(Isolate* isolate, int from, int current, int len,
-                          Vector<const uint8_t> subject, bool unicode) {
+                          Vector<const uint8_t> subject) {
   // For Latin1 characters the unicode flag makes no difference.
   for (int i = 0; i < len; i++) {
     unsigned int old_char = subject[from++];
@@ -747,26 +747,14 @@ IrregexpInterpreter::Result RawMatch(Isolate* isolate, ByteArray code_array,
       DISPATCH();
     }
     BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE) {
-      int from = registers[insn >> BYTECODE_SHIFT];
-      int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
-      if (from >= 0 && len > 0) {
-        if (current + len > subject.length() ||
-            !BackRefMatchesNoCase(isolate, from, current, len, subject, true)) {
-          SET_PC_FROM_OFFSET(Load32Aligned(pc + 4));
-          DISPATCH();
-        }
-        current += len;
-      }
-      ADVANCE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE);
-      DISPATCH();
+      UNREACHABLE();  // TODO(jgruber): Remove this unused bytecode.
     }
     BYTECODE(CHECK_NOT_BACK_REF_NO_CASE) {
       int from = registers[insn >> BYTECODE_SHIFT];
       int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
       if (from >= 0 && len > 0) {
         if (current + len > subject.length() ||
-            !BackRefMatchesNoCase(isolate, from, current, len, subject,
-                                  false)) {
+            !BackRefMatchesNoCase(isolate, from, current, len, subject)) {
           SET_PC_FROM_OFFSET(Load32Aligned(pc + 4));
           DISPATCH();
         }
@@ -776,27 +764,14 @@ IrregexpInterpreter::Result RawMatch(Isolate* isolate, ByteArray code_array,
       DISPATCH();
     }
     BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD) {
-      int from = registers[insn >> BYTECODE_SHIFT];
-      int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
-      if (from >= 0 && len > 0) {
-        if (current - len < 0 ||
-            !BackRefMatchesNoCase(isolate, from, current - len, len, subject,
-                                  true)) {
-          SET_PC_FROM_OFFSET(Load32Aligned(pc + 4));
-          DISPATCH();
-        }
-        current -= len;
-      }
-      ADVANCE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE_BACKWARD);
-      DISPATCH();
+      UNREACHABLE();  // TODO(jgruber): Remove this unused bytecode.
     }
     BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_BACKWARD) {
       int from = registers[insn >> BYTECODE_SHIFT];
       int len = registers[(insn >> BYTECODE_SHIFT) + 1] - from;
       if (from >= 0 && len > 0) {
         if (current - len < 0 ||
-            !BackRefMatchesNoCase(isolate, from, current - len, len, subject,
-                                  false)) {
+            !BackRefMatchesNoCase(isolate, from, current - len, len, subject)) {
           SET_PC_FROM_OFFSET(Load32Aligned(pc + 4));
           DISPATCH();
         }
@@ -1029,6 +1004,8 @@ IrregexpInterpreter::Result IrregexpInterpreter::MatchInternal(
   }
 }
 
+#ifndef COMPILING_IRREGEXP_FOR_EXTERNAL_EMBEDDER
+
 // This method is called through an external reference from RegExpExecInternal
 // builtin.
 IrregexpInterpreter::Result IrregexpInterpreter::MatchForCallFromJs(
@@ -1076,6 +1053,8 @@ IrregexpInterpreter::Result IrregexpInterpreter::MatchForCallFromJs(
   return result;
 }
 
+#endif  // !COMPILING_IRREGEXP_FOR_EXTERNAL_EMBEDDER
+
 IrregexpInterpreter::Result IrregexpInterpreter::MatchForCallFromRuntime(
     Isolate* isolate, Handle<JSRegExp> regexp, Handle<String> subject_string,
     int* registers, int registers_length, int start_position) {
diff --git a/deps/v8/src/regexp/regexp-macro-assembler-arch.h b/deps/v8/src/regexp/regexp-macro-assembler-arch.h
index 2dc6739e42..8ec12a0ae6 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler-arch.h
+++ b/deps/v8/src/regexp/regexp-macro-assembler-arch.h
@@ -15,7 +15,7 @@
 #include "src/regexp/arm64/regexp-macro-assembler-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/regexp/arm/regexp-macro-assembler-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/regexp/ppc/regexp-macro-assembler-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/regexp/mips/regexp-macro-assembler-mips.h"
diff --git a/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc b/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
index 5dca04a18c..0a12201743 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
+++ b/deps/v8/src/regexp/regexp-macro-assembler-tracer.cc
@@ -351,17 +351,15 @@ void RegExpMacroAssemblerTracer::CheckNotBackReference(int start_reg,
   assembler_->CheckNotBackReference(start_reg, read_backward, on_no_match);
 }
 
-
 void RegExpMacroAssemblerTracer::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
-  PrintF(" CheckNotBackReferenceIgnoreCase(register=%d, %s %s, label[%08x]);\n",
+    int start_reg, bool read_backward, Label* on_no_match) {
+  PrintF(" CheckNotBackReferenceIgnoreCase(register=%d, %s, label[%08x]);\n",
          start_reg, read_backward ? "backward" : "forward",
-         unicode ? "unicode" : "non-unicode", LabelToInt(on_no_match));
-  assembler_->CheckNotBackReferenceIgnoreCase(start_reg, read_backward, unicode,
+         LabelToInt(on_no_match));
+  assembler_->CheckNotBackReferenceIgnoreCase(start_reg, read_backward,
                                               on_no_match);
 }
 
-
 void RegExpMacroAssemblerTracer::CheckPosition(int cp_offset,
                                                Label* on_outside_input) {
   PrintF(" CheckPosition(cp_offset=%d, label[%08x]);\n", cp_offset,
diff --git a/deps/v8/src/regexp/regexp-macro-assembler-tracer.h b/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
index 2a44146e73..b6ad63071f 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
+++ b/deps/v8/src/regexp/regexp-macro-assembler-tracer.h
@@ -33,7 +33,6 @@ class RegExpMacroAssemblerTracer: public RegExpMacroAssembler {
   void CheckNotBackReference(int start_reg, bool read_backward,
                              Label* on_no_match) override;
   void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
-                                       bool unicode,
                                        Label* on_no_match) override;
   void CheckNotCharacter(unsigned c, Label* on_not_equal) override;
   void CheckNotCharacterAfterAnd(unsigned c, unsigned and_with,
diff --git a/deps/v8/src/regexp/regexp-macro-assembler.cc b/deps/v8/src/regexp/regexp-macro-assembler.cc
index 30a9955dc3..3ac1bb7f57 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler.cc
+++ b/deps/v8/src/regexp/regexp-macro-assembler.cc
@@ -6,6 +6,7 @@
 
 #include "src/codegen/assembler.h"
 #include "src/execution/isolate-inl.h"
+#include "src/execution/pointer-authentication.h"
 #include "src/execution/simulator.h"
 #include "src/regexp/regexp-stack.h"
 #include "src/strings/unicode-inl.h"
@@ -114,34 +115,7 @@ bool NativeRegExpMacroAssembler::CanReadUnaligned() {
   return FLAG_enable_regexp_unaligned_accesses && !slow_safe();
 }
 
-const byte* NativeRegExpMacroAssembler::StringCharacterPosition(
-    String subject, int start_index, const DisallowHeapAllocation& no_gc) {
-  if (subject.IsConsString()) {
-    subject = ConsString::cast(subject).first();
-  } else if (subject.IsSlicedString()) {
-    start_index += SlicedString::cast(subject).offset();
-    subject = SlicedString::cast(subject).parent();
-  }
-  if (subject.IsThinString()) {
-    subject = ThinString::cast(subject).actual();
-  }
-  DCHECK_LE(0, start_index);
-  DCHECK_LE(start_index, subject.length());
-  if (subject.IsSeqOneByteString()) {
-    return reinterpret_cast<const byte*>(
-        SeqOneByteString::cast(subject).GetChars(no_gc) + start_index);
-  } else if (subject.IsSeqTwoByteString()) {
-    return reinterpret_cast<const byte*>(
-        SeqTwoByteString::cast(subject).GetChars(no_gc) + start_index);
-  } else if (subject.IsExternalOneByteString()) {
-    return reinterpret_cast<const byte*>(
-        ExternalOneByteString::cast(subject).GetChars() + start_index);
-  } else {
-    DCHECK(subject.IsExternalTwoByteString());
-    return reinterpret_cast<const byte*>(
-        ExternalTwoByteString::cast(subject).GetChars() + start_index);
-  }
-}
+#ifndef COMPILING_IRREGEXP_FOR_EXTERNAL_EMBEDDER
 
 // This method may only be called after an interrupt.
 int NativeRegExpMacroAssembler::CheckStackGuardState(
@@ -149,9 +123,10 @@ int NativeRegExpMacroAssembler::CheckStackGuardState(
     Address* return_address, Code re_code, Address* subject,
     const byte** input_start, const byte** input_end) {
   DisallowHeapAllocation no_gc;
+  Address old_pc = PointerAuthentication::AuthenticatePC(return_address, 0);
+  DCHECK_LE(re_code.raw_instruction_start(), old_pc);
+  DCHECK_LE(old_pc, re_code.raw_instruction_end());
 
-  DCHECK(re_code.raw_instruction_start() <= *return_address);
-  DCHECK(*return_address <= re_code.raw_instruction_end());
   StackLimitCheck check(isolate);
   bool js_has_overflowed = check.JsHasOverflowed();
 
@@ -193,9 +168,11 @@ int NativeRegExpMacroAssembler::CheckStackGuardState(
   }
 
   if (*code_handle != re_code) {  // Return address no longer valid
-    intptr_t delta = code_handle->address() - re_code.address();
     // Overwrite the return address on the stack.
-    *return_address += delta;
+    intptr_t delta = code_handle->address() - re_code.address();
+    Address new_pc = old_pc + delta;
+    // TODO(v8:10026): avoid replacing a signed pointer.
+    PointerAuthentication::ReplacePC(return_address, new_pc, 0);
   }
 
   // If we continue, we need to update the subject string addresses.
@@ -210,8 +187,7 @@ int NativeRegExpMacroAssembler::CheckStackGuardState(
     } else {
       *subject = subject_handle->ptr();
       intptr_t byte_length = *input_end - *input_start;
-      *input_start =
-          StringCharacterPosition(*subject_handle, start_index, no_gc);
+      *input_start = subject_handle->AddressOfCharacterAt(start_index, no_gc);
       *input_end = *input_start + byte_length;
     }
   }
@@ -259,7 +235,7 @@ int NativeRegExpMacroAssembler::Match(Handle<JSRegExp> regexp,
 
   DisallowHeapAllocation no_gc;
   const byte* input_start =
-      StringCharacterPosition(subject_ptr, start_offset + slice_offset, no_gc);
+      subject_ptr.AddressOfCharacterAt(start_offset + slice_offset, no_gc);
   int byte_length = char_length << char_size_shift;
   const byte* input_end = input_start + byte_length;
   return Execute(*subject, start_offset, input_start, input_end, offsets_vector,
@@ -305,6 +281,8 @@ int NativeRegExpMacroAssembler::Execute(
   return result;
 }
 
+#endif  // !COMPILING_IRREGEXP_FOR_EXTERNAL_EMBEDDER
+
 // clang-format off
 const byte NativeRegExpMacroAssembler::word_character_map[] = {
     0x00u, 0x00u, 0x00u, 0x00u, 0x00u, 0x00u, 0x00u, 0x00u,
diff --git a/deps/v8/src/regexp/regexp-macro-assembler.h b/deps/v8/src/regexp/regexp-macro-assembler.h
index bda7e5cce1..e83446cdc9 100644
--- a/deps/v8/src/regexp/regexp-macro-assembler.h
+++ b/deps/v8/src/regexp/regexp-macro-assembler.h
@@ -87,7 +87,7 @@ class RegExpMacroAssembler {
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match) = 0;
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match) = 0;
   // Check the current character for a match with a literal character.  If we
   // fail to match then goto the on_failure label.  End of input always
@@ -122,6 +122,11 @@ class RegExpMacroAssembler {
   // not have custom support.
   // May clobber the current loaded character.
   virtual bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match);
+
+  // Control-flow integrity:
+  // Define a jump target and bind a label.
+  virtual void BindJumpTarget(Label* label) { Bind(label); }
+
   virtual void Fail() = 0;
   virtual Handle<HeapObject> GetCode(Handle<String> source) = 0;
   virtual void GoTo(Label* label) = 0;
@@ -246,9 +251,6 @@ class NativeRegExpMacroAssembler: public RegExpMacroAssembler {
   static Address GrowStack(Address stack_pointer, Address* stack_top,
                            Isolate* isolate);
 
-  static const byte* StringCharacterPosition(
-      String subject, int start_index, const DisallowHeapAllocation& no_gc);
-
   static int CheckStackGuardState(Isolate* isolate, int start_index,
                                   RegExp::CallOrigin call_origin,
                                   Address* return_address, Code re_code,
diff --git a/deps/v8/src/regexp/regexp-parser.cc b/deps/v8/src/regexp/regexp-parser.cc
index 951f815374..3c1115414f 100644
--- a/deps/v8/src/regexp/regexp-parser.cc
+++ b/deps/v8/src/regexp/regexp-parser.cc
@@ -24,11 +24,10 @@
 namespace v8 {
 namespace internal {
 
-RegExpParser::RegExpParser(FlatStringReader* in, Handle<String>* error,
-                           JSRegExp::Flags flags, Isolate* isolate, Zone* zone)
+RegExpParser::RegExpParser(FlatStringReader* in, JSRegExp::Flags flags,
+                           Isolate* isolate, Zone* zone)
     : isolate_(isolate),
       zone_(zone),
-      error_(error),
       captures_(nullptr),
       named_captures_(nullptr),
       named_back_references_(nullptr),
@@ -81,13 +80,12 @@ void RegExpParser::Advance() {
       if (FLAG_correctness_fuzzer_suppressions) {
         FATAL("Aborting on stack overflow");
       }
-      ReportError(CStrVector(
-          MessageFormatter::TemplateString(MessageTemplate::kStackOverflow)));
+      ReportError(RegExpError::kStackOverflow);
     } else if (zone()->excess_allocation()) {
       if (FLAG_correctness_fuzzer_suppressions) {
         FATAL("Aborting on excess zone allocation");
       }
-      ReportError(CStrVector("Regular expression too large"));
+      ReportError(RegExpError::kTooLarge);
     } else {
       current_ = ReadNext<true>();
     }
@@ -139,15 +137,12 @@ bool RegExpParser::IsSyntaxCharacterOrSlash(uc32 c) {
   return false;
 }
 
-
-RegExpTree* RegExpParser::ReportError(Vector<const char> message) {
+RegExpTree* RegExpParser::ReportError(RegExpError error) {
   if (failed_) return nullptr;  // Do not overwrite any existing error.
   failed_ = true;
-  *error_ = isolate()
-                ->factory()
-                ->NewStringFromOneByte(Vector<const uint8_t>::cast(message))
-                .ToHandleChecked();
-  // Zip to the end to make sure the no more input is read.
+  error_ = error;
+  error_pos_ = position();
+  // Zip to the end to make sure no more input is read.
   current_ = kEndMarker;
   next_pos_ = in()->length();
   return nullptr;
@@ -194,14 +189,14 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       case kEndMarker:
         if (state->IsSubexpression()) {
           // Inside a parenthesized group when hitting end of input.
-          return ReportError(CStrVector("Unterminated group"));
+          return ReportError(RegExpError::kUnterminatedGroup);
         }
         DCHECK_EQ(INITIAL, state->group_type());
         // Parsing completed successfully.
         return builder->ToRegExp();
       case ')': {
         if (!state->IsSubexpression()) {
-          return ReportError(CStrVector("Unmatched ')'"));
+          return ReportError(RegExpError::kUnmatchedParen);
         }
         DCHECK_NE(INITIAL, state->group_type());
 
@@ -252,7 +247,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       case '*':
       case '+':
       case '?':
-        return ReportError(CStrVector("Nothing to repeat"));
+        return ReportError(RegExpError::kNothingToRepeat);
       case '^': {
         Advance();
         if (builder->multiline()) {
@@ -307,7 +302,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       case '\\':
         switch (Next()) {
           case kEndMarker:
-            return ReportError(CStrVector("\\ at end of pattern"));
+            return ReportError(RegExpError::kEscapeAtEndOfPattern);
           case 'b':
             Advance(2);
             builder->AddAssertion(new (zone()) RegExpAssertion(
@@ -347,7 +342,8 @@ RegExpTree* RegExpParser::ParseDisjunction() {
             if (unicode()) {
               ZoneList<CharacterRange>* ranges =
                   new (zone()) ZoneList<CharacterRange>(2, zone());
-              std::vector<char> name_1, name_2;
+              ZoneVector<char> name_1(zone());
+              ZoneVector<char> name_2(zone());
               if (ParsePropertyClassName(&name_1, &name_2)) {
                 if (AddPropertyClassRange(ranges, p == 'P', name_1, name_2)) {
                   RegExpCharacterClass* cc = new (zone())
@@ -363,7 +359,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
                   }
                 }
               }
-              return ReportError(CStrVector("Invalid property name"));
+              return ReportError(RegExpError::kInvalidPropertyName);
             } else {
               builder->AddCharacter(p);
             }
@@ -399,7 +395,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
             // With /u, no identity escapes except for syntax characters
             // are allowed. Otherwise, all identity escapes are allowed.
             if (unicode()) {
-              return ReportError(CStrVector("Invalid escape"));
+              return ReportError(RegExpError::kInvalidEscape);
             }
             uc32 first_digit = Next();
             if (first_digit == '8' || first_digit == '9') {
@@ -413,7 +409,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
             Advance();
             if (unicode() && Next() >= '0' && Next() <= '9') {
               // With /u, decimal escape with leading 0 are not parsed as octal.
-              return ReportError(CStrVector("Invalid decimal escape"));
+              return ReportError(RegExpError::kInvalidDecimalEscape);
             }
             uc32 octal = ParseOctalLiteral();
             builder->AddCharacter(octal);
@@ -454,7 +450,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
               // ES#prod-annexB-ExtendedPatternCharacter
               if (unicode()) {
                 // With /u, invalid escapes are not treated as identity escapes.
-                return ReportError(CStrVector("Invalid unicode escape"));
+                return ReportError(RegExpError::kInvalidUnicodeEscape);
               }
               builder->AddCharacter('\\');
             } else {
@@ -472,7 +468,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
               builder->AddCharacter('x');
             } else {
               // With /u, invalid escapes are not treated as identity escapes.
-              return ReportError(CStrVector("Invalid escape"));
+              return ReportError(RegExpError::kInvalidEscape);
             }
             break;
           }
@@ -485,7 +481,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
               builder->AddCharacter('u');
             } else {
               // With /u, invalid escapes are not treated as identity escapes.
-              return ReportError(CStrVector("Invalid Unicode escape"));
+              return ReportError(RegExpError::kInvalidUnicodeEscape);
             }
             break;
           }
@@ -509,7 +505,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
               builder->AddCharacter(current());
               Advance();
             } else {
-              return ReportError(CStrVector("Invalid escape"));
+              return ReportError(RegExpError::kInvalidEscape);
             }
             break;
         }
@@ -517,13 +513,13 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       case '{': {
         int dummy;
         bool parsed = ParseIntervalQuantifier(&dummy, &dummy CHECK_FAILED);
-        if (parsed) return ReportError(CStrVector("Nothing to repeat"));
+        if (parsed) return ReportError(RegExpError::kNothingToRepeat);
         V8_FALLTHROUGH;
       }
       case '}':
       case ']':
         if (unicode()) {
-          return ReportError(CStrVector("Lone quantifier brackets"));
+          return ReportError(RegExpError::kLoneQuantifierBrackets);
         }
         V8_FALLTHROUGH;
       default:
@@ -558,13 +554,12 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       case '{':
         if (ParseIntervalQuantifier(&min, &max)) {
           if (max < min) {
-            return ReportError(
-                CStrVector("numbers out of order in {} quantifier"));
+            return ReportError(RegExpError::kRangeOutOfOrder);
           }
           break;
         } else if (unicode()) {
           // With /u, incomplete quantifiers are not allowed.
-          return ReportError(CStrVector("Incomplete quantifier"));
+          return ReportError(RegExpError::kIncompleteQuantifier);
         }
         continue;
       default:
@@ -580,7 +575,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       Advance();
     }
     if (!builder->AddQuantifierToAtom(min, max, quantifier_type)) {
-      return ReportError(CStrVector("Invalid quantifier"));
+      return ReportError(RegExpError::kInvalidQuantifier);
     }
   }
 }
@@ -615,7 +610,7 @@ RegExpParser::RegExpParserState* RegExpParser::ParseOpenParenthesis(
       case 's':
       case 'm': {
         if (!FLAG_regexp_mode_modifiers) {
-          ReportError(CStrVector("Invalid group"));
+          ReportError(RegExpError::kInvalidGroup);
           return nullptr;
         }
         Advance();
@@ -624,7 +619,7 @@ RegExpParser::RegExpParserState* RegExpParser::ParseOpenParenthesis(
           switch (current()) {
             case '-':
               if (!flags_sense) {
-                ReportError(CStrVector("Multiple dashes in flag group"));
+                ReportError(RegExpError::kMultipleFlagDashes);
                 return nullptr;
               }
               flags_sense = false;
@@ -638,7 +633,7 @@ RegExpParser::RegExpParserState* RegExpParser::ParseOpenParenthesis(
               if (current() == 'm') bit = JSRegExp::kMultiline;
               if (current() == 's') bit = JSRegExp::kDotAll;
               if (((switch_on | switch_off) & bit) != 0) {
-                ReportError(CStrVector("Repeated flag in flag group"));
+                ReportError(RegExpError::kRepeatedFlag);
                 return nullptr;
               }
               if (flags_sense) {
@@ -666,7 +661,7 @@ RegExpParser::RegExpParserState* RegExpParser::ParseOpenParenthesis(
               subexpr_type = GROUPING;  // Will break us out of the outer loop.
               continue;
             default:
-              ReportError(CStrVector("Invalid flag group"));
+              ReportError(RegExpError::kInvalidFlagGroup);
               return nullptr;
           }
         }
@@ -690,13 +685,13 @@ RegExpParser::RegExpParserState* RegExpParser::ParseOpenParenthesis(
         Advance();
         break;
       default:
-        ReportError(CStrVector("Invalid group"));
+        ReportError(RegExpError::kInvalidGroup);
         return nullptr;
     }
   }
   if (subexpr_type == CAPTURE) {
     if (captures_started_ >= JSRegExp::kMaxCaptures) {
-      ReportError(CStrVector("Too many captures"));
+      ReportError(RegExpError::kTooManyCaptures);
       return nullptr;
     }
     captures_started_++;
@@ -845,20 +840,20 @@ const ZoneVector<uc16>* RegExpParser::ParseCaptureGroupName() {
     if (c == '\\' && current() == 'u') {
       Advance();
       if (!ParseUnicodeEscape(&c)) {
-        ReportError(CStrVector("Invalid Unicode escape sequence"));
+        ReportError(RegExpError::kInvalidUnicodeEscape);
         return nullptr;
       }
     }
 
     // The backslash char is misclassified as both ID_Start and ID_Continue.
     if (c == '\\') {
-      ReportError(CStrVector("Invalid capture group name"));
+      ReportError(RegExpError::kInvalidCaptureGroupName);
       return nullptr;
     }
 
     if (at_start) {
       if (!IsIdentifierStart(c)) {
-        ReportError(CStrVector("Invalid capture group name"));
+        ReportError(RegExpError::kInvalidCaptureGroupName);
         return nullptr;
       }
       push_code_unit(name, c);
@@ -869,7 +864,7 @@ const ZoneVector<uc16>* RegExpParser::ParseCaptureGroupName() {
       } else if (IsIdentifierPart(c)) {
         push_code_unit(name, c);
       } else {
-        ReportError(CStrVector("Invalid capture group name"));
+        ReportError(RegExpError::kInvalidCaptureGroupName);
         return nullptr;
       }
     }
@@ -896,7 +891,7 @@ bool RegExpParser::CreateNamedCaptureAtIndex(const ZoneVector<uc16>* name,
 
     const auto& named_capture_it = named_captures_->find(capture);
     if (named_capture_it != named_captures_->end()) {
-      ReportError(CStrVector("Duplicate capture group name"));
+      ReportError(RegExpError::kDuplicateCaptureGroupName);
       return false;
     }
   }
@@ -910,7 +905,7 @@ bool RegExpParser::ParseNamedBackReference(RegExpBuilder* builder,
                                            RegExpParserState* state) {
   // The parser is assumed to be on the '<' in \k<name>.
   if (current() != '<') {
-    ReportError(CStrVector("Invalid named reference"));
+    ReportError(RegExpError::kInvalidNamedReference);
     return false;
   }
 
@@ -943,7 +938,7 @@ void RegExpParser::PatchNamedBackReferences() {
   if (named_back_references_ == nullptr) return;
 
   if (named_captures_ == nullptr) {
-    ReportError(CStrVector("Invalid named capture referenced"));
+    ReportError(RegExpError::kInvalidNamedCaptureReference);
     return;
   }
 
@@ -964,7 +959,7 @@ void RegExpParser::PatchNamedBackReferences() {
     if (capture_it != named_captures_->end()) {
       index = (*capture_it)->index();
     } else {
-      ReportError(CStrVector("Invalid named capture referenced"));
+      ReportError(RegExpError::kInvalidNamedCaptureReference);
       return;
     }
 
@@ -1385,8 +1380,8 @@ bool IsUnicodePropertyValueCharacter(char c) {
 
 }  // anonymous namespace
 
-bool RegExpParser::ParsePropertyClassName(std::vector<char>* name_1,
-                                          std::vector<char>* name_2) {
+bool RegExpParser::ParsePropertyClassName(ZoneVector<char>* name_1,
+                                          ZoneVector<char>* name_2) {
   DCHECK(name_1->empty());
   DCHECK(name_2->empty());
   // Parse the property class as follows:
@@ -1425,8 +1420,8 @@ bool RegExpParser::ParsePropertyClassName(std::vector<char>* name_1,
 
 bool RegExpParser::AddPropertyClassRange(ZoneList<CharacterRange>* add_to,
                                          bool negate,
-                                         const std::vector<char>& name_1,
-                                         const std::vector<char>& name_2) {
+                                         const ZoneVector<char>& name_1,
+                                         const ZoneVector<char>& name_2) {
   if (name_2.empty()) {
     // First attempt to interpret as general category property value name.
     const char* name = name_1.data();
@@ -1463,7 +1458,7 @@ bool RegExpParser::AddPropertyClassRange(ZoneList<CharacterRange>* add_to,
   }
 }
 
-RegExpTree* RegExpParser::GetPropertySequence(const std::vector<char>& name_1) {
+RegExpTree* RegExpParser::GetPropertySequence(const ZoneVector<char>& name_1) {
   if (!FLAG_harmony_regexp_sequence) return nullptr;
   const char* name = name_1.data();
   const uc32* sequence_list = nullptr;
@@ -1529,19 +1524,19 @@ RegExpTree* RegExpParser::GetPropertySequence(const std::vector<char>& name_1) {
 
 #else  // V8_INTL_SUPPORT
 
-bool RegExpParser::ParsePropertyClassName(std::vector<char>* name_1,
-                                          std::vector<char>* name_2) {
+bool RegExpParser::ParsePropertyClassName(ZoneVector<char>* name_1,
+                                          ZoneVector<char>* name_2) {
   return false;
 }
 
 bool RegExpParser::AddPropertyClassRange(ZoneList<CharacterRange>* add_to,
                                          bool negate,
-                                         const std::vector<char>& name_1,
-                                         const std::vector<char>& name_2) {
+                                         const ZoneVector<char>& name_1,
+                                         const ZoneVector<char>& name_2) {
   return false;
 }
 
-RegExpTree* RegExpParser::GetPropertySequence(const std::vector<char>& name) {
+RegExpTree* RegExpParser::GetPropertySequence(const ZoneVector<char>& name) {
   return nullptr;
 }
 
@@ -1605,7 +1600,7 @@ uc32 RegExpParser::ParseClassCharacterEscape() {
       }
       if (unicode()) {
         // With /u, invalid escapes are not treated as identity escapes.
-        ReportError(CStrVector("Invalid class escape"));
+        ReportError(RegExpError::kInvalidClassEscape);
         return 0;
       }
       if ((controlLetter >= '0' && controlLetter <= '9') ||
@@ -1638,7 +1633,7 @@ uc32 RegExpParser::ParseClassCharacterEscape() {
       // ES#prod-annexB-LegacyOctalEscapeSequence
       if (unicode()) {
         // With /u, decimal escape is not interpreted as octal character code.
-        ReportError(CStrVector("Invalid class escape"));
+        ReportError(RegExpError::kInvalidClassEscape);
         return 0;
       }
       return ParseOctalLiteral();
@@ -1648,7 +1643,7 @@ uc32 RegExpParser::ParseClassCharacterEscape() {
       if (ParseHexEscape(2, &value)) return value;
       if (unicode()) {
         // With /u, invalid escapes are not treated as identity escapes.
-        ReportError(CStrVector("Invalid escape"));
+        ReportError(RegExpError::kInvalidEscape);
         return 0;
       }
       // If \x is not followed by a two-digit hexadecimal, treat it
@@ -1661,7 +1656,7 @@ uc32 RegExpParser::ParseClassCharacterEscape() {
       if (ParseUnicodeEscape(&value)) return value;
       if (unicode()) {
         // With /u, invalid escapes are not treated as identity escapes.
-        ReportError(CStrVector("Invalid unicode escape"));
+        ReportError(RegExpError::kInvalidUnicodeEscape);
         return 0;
       }
       // If \u is not followed by a two-digit hexadecimal, treat it
@@ -1676,11 +1671,11 @@ uc32 RegExpParser::ParseClassCharacterEscape() {
         Advance();
         return result;
       }
-      ReportError(CStrVector("Invalid escape"));
+      ReportError(RegExpError::kInvalidEscape);
       return 0;
     }
   }
-  return 0;
+  UNREACHABLE();
 }
 
 void RegExpParser::ParseClassEscape(ZoneList<CharacterRange>* ranges,
@@ -1703,17 +1698,18 @@ void RegExpParser::ParseClassEscape(ZoneList<CharacterRange>* ranges,
         return;
       }
       case kEndMarker:
-        ReportError(CStrVector("\\ at end of pattern"));
+        ReportError(RegExpError::kEscapeAtEndOfPattern);
         return;
       case 'p':
       case 'P':
         if (unicode()) {
           bool negate = Next() == 'P';
           Advance(2);
-          std::vector<char> name_1, name_2;
+          ZoneVector<char> name_1(zone);
+          ZoneVector<char> name_2(zone);
           if (!ParsePropertyClassName(&name_1, &name_2) ||
               !AddPropertyClassRange(ranges, negate, name_1, name_2)) {
-            ReportError(CStrVector("Invalid property name in character class"));
+            ReportError(RegExpError::kInvalidClassPropertyName);
           }
           *is_class_escape = true;
           return;
@@ -1732,10 +1728,6 @@ void RegExpParser::ParseClassEscape(ZoneList<CharacterRange>* ranges,
 }
 
 RegExpTree* RegExpParser::ParseCharacterClass(const RegExpBuilder* builder) {
-  static const char* kUnterminated = "Unterminated character class";
-  static const char* kRangeInvalid = "Invalid character class";
-  static const char* kRangeOutOfOrder = "Range out of order in character class";
-
   DCHECK_EQ(current(), '[');
   Advance();
   bool is_negated = false;
@@ -1768,7 +1760,7 @@ RegExpTree* RegExpParser::ParseCharacterClass(const RegExpBuilder* builder) {
         // Either end is an escaped character class. Treat the '-' verbatim.
         if (unicode()) {
           // ES2015 21.2.2.15.1 step 1.
-          return ReportError(CStrVector(kRangeInvalid));
+          return ReportError(RegExpError::kInvalidCharacterClass);
         }
         if (!is_class_1) ranges->Add(CharacterRange::Singleton(char_1), zone());
         ranges->Add(CharacterRange::Singleton('-'), zone());
@@ -1777,7 +1769,7 @@ RegExpTree* RegExpParser::ParseCharacterClass(const RegExpBuilder* builder) {
       }
       // ES2015 21.2.2.15.1 step 6.
       if (char_1 > char_2) {
-        return ReportError(CStrVector(kRangeOutOfOrder));
+        return ReportError(RegExpError::kOutOfOrderCharacterClass);
       }
       ranges->Add(CharacterRange::Range(char_1, char_2), zone());
     } else {
@@ -1785,7 +1777,7 @@ RegExpTree* RegExpParser::ParseCharacterClass(const RegExpBuilder* builder) {
     }
   }
   if (!has_more()) {
-    return ReportError(CStrVector(kUnterminated));
+    return ReportError(RegExpError::kUnterminatedCharacterClass);
   }
   Advance();
   RegExpCharacterClass::CharacterClassFlags character_class_flags;
@@ -1802,14 +1794,16 @@ bool RegExpParser::ParseRegExp(Isolate* isolate, Zone* zone,
                                FlatStringReader* input, JSRegExp::Flags flags,
                                RegExpCompileData* result) {
   DCHECK(result != nullptr);
-  RegExpParser parser(input, &result->error, flags, isolate, zone);
+  RegExpParser parser(input, flags, isolate, zone);
   RegExpTree* tree = parser.ParsePattern();
   if (parser.failed()) {
     DCHECK(tree == nullptr);
-    DCHECK(!result->error.is_null());
+    DCHECK(parser.error_ != RegExpError::kNone);
+    result->error = parser.error_;
+    result->error_pos = parser.error_pos_;
   } else {
     DCHECK(tree != nullptr);
-    DCHECK(result->error.is_null());
+    DCHECK(parser.error_ == RegExpError::kNone);
     if (FLAG_trace_regexp_parser) {
       StdoutStream os;
       tree->Print(os, zone);
diff --git a/deps/v8/src/regexp/regexp-parser.h b/deps/v8/src/regexp/regexp-parser.h
index cc1948b101..aff1746bc5 100644
--- a/deps/v8/src/regexp/regexp-parser.h
+++ b/deps/v8/src/regexp/regexp-parser.h
@@ -8,6 +8,7 @@
 #include "src/objects/js-regexp.h"
 #include "src/objects/objects.h"
 #include "src/regexp/regexp-ast.h"
+#include "src/regexp/regexp-error.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
@@ -153,8 +154,8 @@ class RegExpBuilder : public ZoneObject {
 
 class V8_EXPORT_PRIVATE RegExpParser {
  public:
-  RegExpParser(FlatStringReader* in, Handle<String>* error,
-               JSRegExp::Flags flags, Isolate* isolate, Zone* zone);
+  RegExpParser(FlatStringReader* in, JSRegExp::Flags flags, Isolate* isolate,
+               Zone* zone);
 
   static bool ParseRegExp(Isolate* isolate, Zone* zone, FlatStringReader* input,
                           JSRegExp::Flags flags, RegExpCompileData* result);
@@ -177,13 +178,13 @@ class V8_EXPORT_PRIVATE RegExpParser {
   bool ParseUnicodeEscape(uc32* value);
   bool ParseUnlimitedLengthHexNumber(int max_value, uc32* value);
 
-  bool ParsePropertyClassName(std::vector<char>* name_1,
-                              std::vector<char>* name_2);
+  bool ParsePropertyClassName(ZoneVector<char>* name_1,
+                              ZoneVector<char>* name_2);
   bool AddPropertyClassRange(ZoneList<CharacterRange>* add_to, bool negate,
-                             const std::vector<char>& name_1,
-                             const std::vector<char>& name_2);
+                             const ZoneVector<char>& name_1,
+                             const ZoneVector<char>& name_2);
 
-  RegExpTree* GetPropertySequence(const std::vector<char>& name_1);
+  RegExpTree* GetPropertySequence(const ZoneVector<char>& name_1);
   RegExpTree* ParseCharacterClass(const RegExpBuilder* state);
 
   uc32 ParseOctalLiteral();
@@ -202,7 +203,7 @@ class V8_EXPORT_PRIVATE RegExpParser {
 
   char ParseClassEscape();
 
-  RegExpTree* ReportError(Vector<const char> message);
+  RegExpTree* ReportError(RegExpError error);
   void Advance();
   void Advance(int dist);
   void Reset(int pos);
@@ -335,7 +336,8 @@ class V8_EXPORT_PRIVATE RegExpParser {
 
   Isolate* isolate_;
   Zone* zone_;
-  Handle<String>* error_;
+  RegExpError error_ = RegExpError::kNone;
+  int error_pos_ = 0;
   ZoneList<RegExpCapture*>* captures_;
   ZoneSet<RegExpCapture*, RegExpCaptureNameLess>* named_captures_;
   ZoneList<RegExpBackReference*>* named_back_references_;
diff --git a/deps/v8/src/regexp/regexp-stack.h b/deps/v8/src/regexp/regexp-stack.h
index cd199adfb2..9394398fcc 100644
--- a/deps/v8/src/regexp/regexp-stack.h
+++ b/deps/v8/src/regexp/regexp-stack.h
@@ -38,6 +38,9 @@ class RegExpStackScope {
 
 class RegExpStack {
  public:
+  RegExpStack();
+  ~RegExpStack();
+
   // Number of allocated locations on the stack below the limit.
   // No sequence of pushes must be longer that this without doing a stack-limit
   // check.
@@ -77,9 +80,6 @@ class RegExpStack {
   static constexpr size_t kMaximumStackSize = 64 * MB;
 
  private:
-  RegExpStack();
-  ~RegExpStack();
-
   // Artificial limit used when the thread-local state has been destroyed.
   static const Address kMemoryTop =
       static_cast<Address>(static_cast<uintptr_t>(-1));
diff --git a/deps/v8/src/regexp/regexp.cc b/deps/v8/src/regexp/regexp.cc
index 3632deaeb8..4319990a39 100644
--- a/deps/v8/src/regexp/regexp.cc
+++ b/deps/v8/src/regexp/regexp.cc
@@ -14,6 +14,7 @@
 #include "src/regexp/regexp-dotprinter.h"
 #include "src/regexp/regexp-interpreter.h"
 #include "src/regexp/regexp-macro-assembler-arch.h"
+#include "src/regexp/regexp-macro-assembler-tracer.h"
 #include "src/regexp/regexp-parser.h"
 #include "src/strings/string-search.h"
 #include "src/utils/ostreams.h"
@@ -91,9 +92,15 @@ class RegExpImpl final : public AllStatic {
 };
 
 V8_WARN_UNUSED_RESULT
-static inline MaybeHandle<Object> ThrowRegExpException(
-    Isolate* isolate, Handle<JSRegExp> re, Handle<String> pattern,
-    Handle<String> error_text) {
+static inline MaybeHandle<Object> ThrowRegExpException(Isolate* isolate,
+                                                       Handle<JSRegExp> re,
+                                                       Handle<String> pattern,
+                                                       RegExpError error) {
+  Vector<const char> error_data = CStrVector(RegExpErrorString(error));
+  Handle<String> error_text =
+      isolate->factory()
+          ->NewStringFromOneByte(Vector<const uint8_t>::cast(error_data))
+          .ToHandleChecked();
   THROW_NEW_ERROR(
       isolate,
       NewSyntaxError(MessageTemplate::kMalformedRegExp, pattern, error_text),
@@ -101,7 +108,7 @@ static inline MaybeHandle<Object> ThrowRegExpException(
 }
 
 inline void ThrowRegExpException(Isolate* isolate, Handle<JSRegExp> re,
-                                 Handle<String> error_text) {
+                                 RegExpError error_text) {
   USE(ThrowRegExpException(isolate, re, Handle<String>(re->Pattern(), isolate),
                            error_text));
 }
@@ -407,7 +414,7 @@ bool RegExpImpl::CompileIrregexp(Isolate* isolate, Handle<JSRegExp> re,
       Compile(isolate, &zone, &compile_data, flags, pattern, sample_subject,
               is_one_byte, re->BacktrackLimit());
   if (!compilation_succeeded) {
-    DCHECK(!compile_data.error.is_null());
+    DCHECK(compile_data.error != RegExpError::kNone);
     ThrowRegExpException(isolate, re, compile_data.error);
     return false;
   }
@@ -740,8 +747,7 @@ bool RegExpImpl::Compile(Isolate* isolate, Zone* zone, RegExpCompileData* data,
                          Handle<String> sample_subject, bool is_one_byte,
                          uint32_t backtrack_limit) {
   if ((data->capture_count + 1) * 2 - 1 > RegExpMacroAssembler::kMaxRegister) {
-    data->error =
-        isolate->factory()->NewStringFromAsciiChecked("RegExp too big");
+    data->error = RegExpError::kTooLarge;
     return false;
   }
 
@@ -809,8 +815,8 @@ bool RegExpImpl::Compile(Isolate* isolate, Zone* zone, RegExpCompileData* data,
 
   if (node == nullptr) node = new (zone) EndNode(EndNode::BACKTRACK, zone);
   data->node = node;
-  if (const char* error_message = AnalyzeRegExp(isolate, is_one_byte, node)) {
-    data->error = isolate->factory()->NewStringFromAsciiChecked(error_message);
+  data->error = AnalyzeRegExp(isolate, is_one_byte, node);
+  if (data->error != RegExpError::kNone) {
     return false;
   }
 
@@ -839,7 +845,7 @@ bool RegExpImpl::Compile(Isolate* isolate, Zone* zone, RegExpCompileData* data,
 #elif V8_TARGET_ARCH_S390
     macro_assembler.reset(new RegExpMacroAssemblerS390(
         isolate, zone, mode, (data->capture_count + 1) * 2));
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
     macro_assembler.reset(new RegExpMacroAssemblerPPC(
         isolate, zone, mode, (data->capture_count + 1) * 2));
 #elif V8_TARGET_ARCH_MIPS
@@ -878,8 +884,18 @@ bool RegExpImpl::Compile(Isolate* isolate, Zone* zone, RegExpCompileData* data,
     macro_assembler->set_global_mode(mode);
   }
 
+  RegExpMacroAssembler* macro_assembler_ptr = macro_assembler.get();
+#ifdef DEBUG
+  std::unique_ptr<RegExpMacroAssembler> tracer_macro_assembler;
+  if (FLAG_trace_regexp_assembler) {
+    tracer_macro_assembler.reset(
+        new RegExpMacroAssemblerTracer(isolate, macro_assembler_ptr));
+    macro_assembler_ptr = tracer_macro_assembler.get();
+  }
+#endif
+
   RegExpCompiler::CompilationResult result = compiler.Assemble(
-      isolate, macro_assembler.get(), node, data->capture_count, pattern);
+      isolate, macro_assembler_ptr, node, data->capture_count, pattern);
 
   // Code / bytecode printing.
   {
@@ -902,13 +918,12 @@ bool RegExpImpl::Compile(Isolate* isolate, Zone* zone, RegExpCompileData* data,
     }
   }
 
-  if (result.error_message != nullptr) {
+  if (result.error != RegExpError::kNone) {
     if (FLAG_correctness_fuzzer_suppressions &&
-        strncmp(result.error_message, "Stack overflow", 15) == 0) {
+        result.error == RegExpError::kStackOverflow) {
       FATAL("Aborting on stack overflow");
     }
-    data->error =
-        isolate->factory()->NewStringFromAsciiChecked(result.error_message);
+    data->error = result.error;
   }
 
   data->code = result.code;
diff --git a/deps/v8/src/regexp/regexp.h b/deps/v8/src/regexp/regexp.h
index 9f3581d18e..27ccbb47ba 100644
--- a/deps/v8/src/regexp/regexp.h
+++ b/deps/v8/src/regexp/regexp.h
@@ -6,6 +6,7 @@
 #define V8_REGEXP_REGEXP_H_
 
 #include "src/objects/js-regexp.h"
+#include "src/regexp/regexp-error.h"
 
 namespace v8 {
 namespace internal {
@@ -42,7 +43,11 @@ struct RegExpCompileData {
 
   // The error message. Only used if an error occurred during parsing or
   // compilation.
-  Handle<String> error;
+  RegExpError error = RegExpError::kNone;
+
+  // The position at which the error was detected. Only used if an
+  // error occurred.
+  int error_pos = 0;
 
   // The number of capture groups, without the global capture \0.
   int capture_count = 0;
diff --git a/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.cc b/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.cc
index bcef02369f..be4b85df4f 100644
--- a/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.cc
+++ b/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.cc
@@ -113,6 +113,8 @@ RegExpMacroAssemblerS390::RegExpMacroAssemblerS390(Isolate* isolate, Zone* zone,
       backtrack_label_(),
       exit_label_(),
       internal_failure_label_() {
+  masm_->set_root_array_available(false);
+
   DCHECK_EQ(0, registers_to_save % 2);
 
   __ b(&entry_label_);  // We'll write the entry code later.
@@ -228,7 +230,7 @@ void RegExpMacroAssemblerS390::CheckGreedyLoop(Label* on_equal) {
 }
 
 void RegExpMacroAssemblerS390::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   __ LoadP(r2, register_location(start_reg));      // Index of start of
                                                    // capture
@@ -325,7 +327,7 @@ void RegExpMacroAssemblerS390::CheckNotBackReferenceIgnoreCase(
     //   r2: Address byte_offset1 - Address captured substring's start.
     //   r3: Address byte_offset2 - Address of current character position.
     //   r4: size_t byte_length - length of capture in bytes(!)
-    //   r5: Isolate* isolate or 0 if unicode flag.
+    //   r5: Isolate* isolate.
 
     // Address of start of capture.
     __ AddP(r2, end_of_input_address());
@@ -339,14 +341,7 @@ void RegExpMacroAssemblerS390::CheckNotBackReferenceIgnoreCase(
       __ SubP(r3, r3, r6);
     }
 // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ LoadImmP(r5, Operand::Zero());
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
-    }
+    __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
 
     {
       AllowExternalCallThatCantCauseGC scope(masm_);
diff --git a/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.h b/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.h
index 4f79296d78..eced564d7f 100644
--- a/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.h
+++ b/deps/v8/src/regexp/s390/regexp-macro-assembler-s390.h
@@ -36,7 +36,7 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerS390
   virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                      Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
-                                               bool read_backward, bool unicode,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(unsigned c, unsigned mask,
diff --git a/deps/v8/src/regexp/special-case.h b/deps/v8/src/regexp/special-case.h
index 1ccec5d31a..753c9231ed 100644
--- a/deps/v8/src/regexp/special-case.h
+++ b/deps/v8/src/regexp/special-case.h
@@ -6,70 +6,109 @@
 #define V8_REGEXP_SPECIAL_CASE_H_
 
 #ifdef V8_INTL_SUPPORT
-#include "unicode/uversion.h"
-namespace U_ICU_NAMESPACE {
-class UnicodeSet;
-}  //  namespace U_ICU_NAMESPACE
+#include "src/base/logging.h"
+#include "src/common/globals.h"
+
+#include "unicode/uchar.h"
+#include "unicode/uniset.h"
+#include "unicode/unistr.h"
 
 namespace v8 {
 namespace internal {
 
-// Functions to build special sets of Unicode characters that need special
-// handling under "i" mode that cannot use closeOver(USET_CASE_INSENSITIVE).
+// Sets of Unicode characters that need special handling under "i" mode
+
+// For non-unicode ignoreCase matches (aka "i", not "iu"), ECMA 262
+// defines slightly different case-folding rules than Unicode. An
+// input character should match a pattern character if the result of
+// the Canonicalize algorithm is the same for both characters.
 //
-// For the characters in the "ignore set", the process should not treat other
-// characters in the result of closeOver(USET_CASE_INSENSITIVE) as case
-// equivlant under the ECMA262 RegExp "i" mode because these characters are
-// uppercase themselves that no other characters in the set uppercase to.
+// Roughly speaking, for "i" regexps, Canonicalize(c) is the same as
+// c.toUpperCase(), unless a) c.toUpperCase() is a multi-character
+// string, or b) c is non-ASCII, and c.toUpperCase() is ASCII. See
+// https://tc39.es/ecma262/#sec-runtime-semantics-canonicalize-ch for
+// the precise definition.
 //
-// For the characters in the "special add set", the proecess should add only
-// those characters in the result of closeOver(USET_CASE_INSENSITIVE) which is
-// not uppercase characters as case equivlant under the ECMA262 RegExp "i" mode
-// and also that ONE uppercase character that other non uppercase character
-// uppercase into to the set. Other uppercase characters in the result of
-// closeOver(USET_CASE_INSENSITIVE) should not be considered because ECMA262
-// RegExp "i" mode consider two characters as "case equivlant" if both
-// characters uppercase to the same character.
+// While compiling such regular expressions, we need to compute the
+// set of characters that should match a given input character. (See
+// GetCaseIndependentLetters and CharacterRange::AddCaseEquivalents.)
+// For almost all characters, this can be efficiently computed using
+// UnicodeSet::closeOver(USET_CASE_INSENSITIVE). These sets represent
+// the remaining special cases.
 //
-// For example, consider the following case equivalent set defined by Unicode
-// standard. Notice there are more than one uppercase characters in this set:
-//  U+212B Å Angstrom Sign - an uppercase character.
-//  U+00C5 Å Latin Capital Letter A with Ring Above - an uppercase character.
-//  U+00E5 å Latin Small Letter A with Ring Above - a lowercase character which
-//    uppercase to U+00C5.
-// In this case equivlant set is a special set and need special handling while
-// considering "case equivlant" under the ECMA262 RegExp "i" mode which is
-// different than Unicode Standard:
-//  * U+212B should be included into the "ignore" set because there are no other
-//    characters, under the ECMA262 "i" mode, are considered as "case equivlant"
-//    to it because U+212B is itself an uppercase but neither U+00C5 nor U+00E5
-//    uppercase to U+212B.
-//  * U+00C5 and U+00E5 will both be included into the "special add" set. While
-//    calculate the "equivlant set" under ECMA262 "i" mode, the process will
-//    add U+00E5, because it is not an uppercase character in the set. The
-//    process will also add U+00C5, because it is the uppercase character which
-//    other non uppercase character, U+00C5, uppercase into.
+// For a character c, the rules are as follows:
 //
-// For characters not included in "ignore set" and "special add set", the
-// process will just use closeOver(USET_CASE_INSENSITIVE) to calcualte, which is
-// much faster.
+// 1. If c is in neither IgnoreSet nor SpecialAddSet, then calling
+//    UnicodeSet::closeOver(USET_CASE_INSENSITIVE) on a UnicodeSet
+//    containing c will produce the set of characters that should
+//    match /c/i (or /[c]/i), and only those characters.
 //
-// Under Unicode 12.0, there are only 7 characters in the "special add set" and
-// 4 characters in "ignore set" so even the special add process is slower, it is
-// limited to a small set of cases only.
+// 2. If c is in IgnoreSet, then the only character it should match is
+//    itself. However, closeOver will add additional incorrect
+//    matches. For example, consider SHARP S: 'ß' (U+00DF) and 'ẞ'
+//    (U+1E9E). Although closeOver('ß') = "ßẞ", uppercase('ß') is
+//    "SS".  Step 3.e therefore requires that 'ß' canonicalizes to
+//    itself, and should not match 'ẞ'. In these cases, we can skip
+//    the closeOver entirely, because it will never add an equivalent
+//    character.
 //
-// The implementation of these two function will be generated by calling ICU
-// icu::UnicodeSet during the build time into gen/src/regexp/special-case.cc by
-// the code in src/regexp/gen-regexp-special-case.cc.
+// 3. If c is in SpecialAddSet, then it should match at least one
+//    character other than itself. However, closeOver will add at
+//    least one additional incorrect match. For example, consider the
+//    letter 'k'. Closing over 'k' gives "kKK" (lowercase k, uppercase
+//    K, U+212A KELVIN SIGN). However, because of step 3.g, KELVIN
+//    SIGN should not match either of the other two characters. As a
+//    result, "k" and "K" are in SpecialAddSet (and KELVIN SIGN is in
+//    IgnoreSet). To find the correct matches for characters in
+//    SpecialAddSet, we closeOver the original character, but filter
+//    out the results that do not have the same canonical value.
 //
-// These two function will be used with LazyInstance<> template to generate
-// global sharable set to reduce memory usage and speed up performance.
+// The contents of these sets are calculated at build time by
+// src/regexp/gen-regexp-special-case.cc, which generates
+// gen/src/regexp/special-case.cc. This is done by iterating over the
+// result of closeOver for each BMP character, and finding sets for
+// which at least one character has a different canonical value than
+// another character. Characters that match no other characters in
+// their equivalence class are added to IgnoreSet. Characters that
+// match at least one other character are added to SpecialAddSet.
+
+class RegExpCaseFolding final : public AllStatic {
+ public:
+  static const icu::UnicodeSet& IgnoreSet();
+  static const icu::UnicodeSet& SpecialAddSet();
+
+  // This implements ECMAScript 2020 21.2.2.8.2 (Runtime Semantics:
+  // Canonicalize) step 3, which is used to determine whether
+  // characters match when ignoreCase is true and unicode is false.
+  static UChar32 Canonicalize(UChar32 ch) {
+    // a. Assert: ch is a UTF-16 code unit.
+    CHECK_LE(ch, 0xffff);
+
+    // b. Let s be the String value consisting of the single code unit ch.
+    icu::UnicodeString s(ch);
+
+    // c. Let u be the same result produced as if by performing the algorithm
+    // for String.prototype.toUpperCase using s as the this value.
+    // d. Assert: Type(u) is String.
+    icu::UnicodeString& u = s.toUpper();
+
+    // e. If u does not consist of a single code unit, return ch.
+    if (u.length() != 1) {
+      return ch;
+    }
+
+    // f. Let cu be u's single code unit element.
+    UChar32 cu = u.char32At(0);
 
-// Function to build and return the Ignore set.
-icu::UnicodeSet BuildIgnoreSet();
+    // g. If the value of ch >= 128 and the value of cu < 128, return ch.
+    if (ch >= 128 && cu < 128) {
+      return ch;
+    }
 
-// Function to build and return the Special Add set.
-icu::UnicodeSet BuildSpecialAddSet();
+    // h. Return cu.
+    return cu;
+  }
+};
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.cc b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
index 5620c6b9ce..5edbf5e579 100644
--- a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
+++ b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.cc
@@ -214,9 +214,8 @@ void RegExpMacroAssemblerX64::CheckGreedyLoop(Label* on_equal) {
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
-    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+    int start_reg, bool read_backward, Label* on_no_match) {
   Label fallthrough;
   ReadPositionFromRegister(rdx, start_reg);  // Offset of start of capture
   ReadPositionFromRegister(rbx, start_reg + 1);  // Offset of end of capture
@@ -321,7 +320,7 @@ void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
     //   Address byte_offset1 - Address captured substring's start.
     //   Address byte_offset2 - Address of current character position.
     //   size_t byte_length - length of capture in bytes(!)
-//   Isolate* isolate or 0 if unicode flag.
+    //   Isolate* isolate.
 #ifdef V8_TARGET_OS_WIN
     DCHECK(rcx == arg_reg_1);
     DCHECK(rdx == arg_reg_2);
@@ -349,14 +348,7 @@ void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
     // Set byte_length.
     __ movq(arg_reg_3, rbx);
     // Isolate.
-#ifdef V8_INTL_SUPPORT
-    if (unicode) {
-      __ movq(arg_reg_4, Immediate(0));
-    } else  // NOLINT
-#endif      // V8_INTL_SUPPORT
-    {
-      __ LoadAddress(arg_reg_4, ExternalReference::isolate_address(isolate()));
-    }
+    __ LoadAddress(arg_reg_4, ExternalReference::isolate_address(isolate()));
 
     { // NOLINT: Can't find a way to open this scope without confusing the
       // linter.
@@ -388,7 +380,6 @@ void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
   __ bind(&fallthrough);
 }
 
-
 void RegExpMacroAssemblerX64::CheckNotBackReference(int start_reg,
                                                     bool read_backward,
                                                     Label* on_no_match) {
diff --git a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
index 0bf1c2e150..64614e228a 100644
--- a/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
+++ b/deps/v8/src/regexp/x64/regexp-macro-assembler-x64.h
@@ -37,7 +37,6 @@ class V8_EXPORT_PRIVATE RegExpMacroAssemblerX64
   void CheckNotBackReference(int start_reg, bool read_backward,
                              Label* on_no_match) override;
   void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
-                                       bool unicode,
                                        Label* on_no_match) override;
   void CheckNotCharacter(uint32_t c, Label* on_not_equal) override;
   void CheckNotCharacterAfterAnd(uint32_t c, uint32_t mask,
diff --git a/deps/v8/src/roots/roots-inl.h b/deps/v8/src/roots/roots-inl.h
index 65c0c4a324..2a5fabd216 100644
--- a/deps/v8/src/roots/roots-inl.h
+++ b/deps/v8/src/roots/roots-inl.h
@@ -8,8 +8,8 @@
 #include "src/roots/roots.h"
 
 #include "src/execution/isolate.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/handles/handles.h"
-#include "src/heap/off-thread-factory.h"
 #include "src/heap/read-only-heap.h"
 #include "src/objects/api-callbacks.h"
 #include "src/objects/descriptor-array.h"
@@ -66,8 +66,8 @@ ReadOnlyRoots::ReadOnlyRoots(Isolate* isolate)
     : read_only_roots_(reinterpret_cast<Address*>(
           isolate->roots_table().read_only_roots_begin().address())) {}
 
-ReadOnlyRoots::ReadOnlyRoots(OffThreadFactory* factory)
-    : ReadOnlyRoots(factory->read_only_roots()) {}
+ReadOnlyRoots::ReadOnlyRoots(OffThreadIsolate* isolate)
+    : ReadOnlyRoots(isolate->factory()->read_only_roots()) {}
 
 ReadOnlyRoots::ReadOnlyRoots(Address* ro_roots) : read_only_roots_(ro_roots) {}
 
diff --git a/deps/v8/src/roots/roots.h b/deps/v8/src/roots/roots.h
index 391c1facea..cf84ebf40b 100644
--- a/deps/v8/src/roots/roots.h
+++ b/deps/v8/src/roots/roots.h
@@ -7,6 +7,7 @@
 
 #include "src/builtins/accessors.h"
 #include "src/common/globals.h"
+#include "src/handles/handles.h"
 #include "src/init/heap-symbols.h"
 #include "src/objects/objects-definitions.h"
 #include "src/objects/objects.h"
@@ -17,7 +18,7 @@ namespace internal {
 
 // Forward declarations.
 enum ElementsKind : uint8_t;
-class OffThreadFactory;
+class OffThreadIsolate;
 template <typename T>
 class Handle;
 class Heap;
@@ -83,6 +84,7 @@ class Symbol;
   V(Map, object_boilerplate_description_map, ObjectBoilerplateDescriptionMap)  \
   V(Map, bytecode_array_map, BytecodeArrayMap)                                 \
   V(Map, code_data_container_map, CodeDataContainerMap)                        \
+  V(Map, coverage_info_map, CoverageInfoMap)                                   \
   V(Map, descriptor_array_map, DescriptorArrayMap)                             \
   V(Map, fixed_double_array_map, FixedDoubleArrayMap)                          \
   V(Map, global_dictionary_map, GlobalDictionaryMap)                           \
@@ -250,8 +252,6 @@ class Symbol;
   V(TemplateList, message_listeners, MessageListeners)                     \
   /* Support for async stack traces */                                     \
   V(HeapObject, current_microtask, CurrentMicrotask)                       \
-  /* JSFinalizationGroup objects which need cleanup */                     \
-  V(Object, dirty_js_finalization_groups, DirtyJSFinalizationGroups)       \
   /* KeepDuringJob set for JS WeakRefs */                                  \
   V(HeapObject, weak_refs_keep_during_job, WeakRefsKeepDuringJob)          \
   V(HeapObject, interpreter_entry_trampoline_for_profiling,                \
@@ -302,14 +302,15 @@ class Symbol;
 #define ACCESSOR_INFO_ROOT_LIST(V) \
   ACCESSOR_INFO_LIST_GENERATOR(ACCESSOR_INFO_ROOT_LIST_ADAPTER, V)
 
-#define READ_ONLY_ROOT_LIST(V)     \
-  STRONG_READ_ONLY_ROOT_LIST(V)    \
-  INTERNALIZED_STRING_ROOT_LIST(V) \
-  PRIVATE_SYMBOL_ROOT_LIST(V)      \
-  PUBLIC_SYMBOL_ROOT_LIST(V)       \
-  WELL_KNOWN_SYMBOL_ROOT_LIST(V)   \
-  STRUCT_MAPS_LIST(V)              \
-  ALLOCATION_SITE_MAPS_LIST(V)     \
+#define READ_ONLY_ROOT_LIST(V)       \
+  STRONG_READ_ONLY_ROOT_LIST(V)      \
+  INTERNALIZED_STRING_ROOT_LIST(V)   \
+  PRIVATE_SYMBOL_ROOT_LIST(V)        \
+  PUBLIC_SYMBOL_ROOT_LIST(V)         \
+  WELL_KNOWN_SYMBOL_ROOT_LIST(V)     \
+  STRUCT_MAPS_LIST(V)                \
+  TORQUE_INTERNAL_CLASS_MAPS_LIST(V) \
+  ALLOCATION_SITE_MAPS_LIST(V)       \
   DATA_HANDLER_MAPS_LIST(V)
 
 #define MUTABLE_ROOT_LIST(V)                \
@@ -480,7 +481,7 @@ class ReadOnlyRoots {
 
   V8_INLINE explicit ReadOnlyRoots(Heap* heap);
   V8_INLINE explicit ReadOnlyRoots(Isolate* isolate);
-  V8_INLINE explicit ReadOnlyRoots(OffThreadFactory* factory);
+  V8_INLINE explicit ReadOnlyRoots(OffThreadIsolate* isolate);
 
 #define ROOT_ACCESSOR(Type, name, CamelName) \
   V8_INLINE class Type name() const;         \
diff --git a/deps/v8/src/runtime/runtime-array.cc b/deps/v8/src/runtime/runtime-array.cc
index 52c9c3098b..3e72d5e816 100644
--- a/deps/v8/src/runtime/runtime-array.cc
+++ b/deps/v8/src/runtime/runtime-array.cc
@@ -46,9 +46,14 @@ RUNTIME_FUNCTION(Runtime_NewArray) {
   HandleScope scope(isolate);
   DCHECK_LE(3, args.length());
   int const argc = args.length() - 3;
-  // TODO(bmeurer): Remove this Arguments nonsense.
-  Arguments argv(argc, args.address_of_arg_at(1));
+  // argv points to the arguments constructed by the JavaScript call.
+#ifdef V8_REVERSE_JSARGS
+  JavaScriptArguments argv(argc, args.address_of_arg_at(0));
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, argc);
+#else
+  JavaScriptArguments argv(argc, args.address_of_arg_at(1));
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 0);
+#endif
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, new_target, argc + 1);
   CONVERT_ARG_HANDLE_CHECKED(HeapObject, type_info, argc + 2);
   // TODO(bmeurer): Use MaybeHandle to pass around the AllocationSite.
diff --git a/deps/v8/src/runtime/runtime-atomics.cc b/deps/v8/src/runtime/runtime-atomics.cc
index 7c7a8b6207..34259c6e67 100644
--- a/deps/v8/src/runtime/runtime-atomics.cc
+++ b/deps/v8/src/runtime/runtime-atomics.cc
@@ -345,7 +345,7 @@ struct Xor {
 // but also includes the ToInteger/ToBigInt conversion that's part of
 // https://tc39.github.io/ecma262/#sec-atomicreadmodifywrite
 template <template <typename> class Op>
-Object GetModifySetValueInBuffer(Arguments args, Isolate* isolate) {
+Object GetModifySetValueInBuffer(RuntimeArguments args, Isolate* isolate) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
diff --git a/deps/v8/src/runtime/runtime-classes.cc b/deps/v8/src/runtime/runtime-classes.cc
index 2aa1dafd0d..b6e0ebab96 100644
--- a/deps/v8/src/runtime/runtime-classes.cc
+++ b/deps/v8/src/runtime/runtime-classes.cc
@@ -157,7 +157,8 @@ inline void SetHomeObject(Isolate* isolate, JSFunction method,
 //    shared name.
 template <typename Dictionary>
 MaybeHandle<Object> GetMethodAndSetHomeObjectAndName(
-    Isolate* isolate, Arguments& args,  // NOLINT(runtime/references)
+    Isolate* isolate,
+    RuntimeArguments& args,  // NOLINT(runtime/references)
     Smi index, Handle<JSObject> home_object, Handle<String> name_prefix,
     Handle<Object> key) {
   int int_index = index.value();
@@ -195,7 +196,7 @@ MaybeHandle<Object> GetMethodAndSetHomeObjectAndName(
 // shared name.
 Object GetMethodWithSharedNameAndSetHomeObject(
     Isolate* isolate,
-    Arguments& args,  // NOLINT(runtime/references)
+    RuntimeArguments& args,  // NOLINT(runtime/references)
     Object index, JSObject home_object) {
   DisallowHeapAllocation no_gc;
   int int_index = Smi::ToInt(index);
@@ -235,7 +236,7 @@ Handle<Dictionary> ShallowCopyDictionaryTemplate(
 template <typename Dictionary>
 bool SubstituteValues(Isolate* isolate, Handle<Dictionary> dictionary,
                       Handle<JSObject> receiver,
-                      Arguments& args,  // NOLINT(runtime/references)
+                      RuntimeArguments& args,  // NOLINT(runtime/references)
                       bool* install_name_accessor = nullptr) {
   Handle<Name> name_string = isolate->factory()->name_string();
 
@@ -312,7 +313,8 @@ bool AddDescriptorsByTemplate(
     Isolate* isolate, Handle<Map> map,
     Handle<DescriptorArray> descriptors_template,
     Handle<NumberDictionary> elements_dictionary_template,
-    Handle<JSObject> receiver, Arguments& args) {  // NOLINT(runtime/references)
+    Handle<JSObject> receiver,
+    RuntimeArguments& args) {  // NOLINT(runtime/references)
   int nof_descriptors = descriptors_template->number_of_descriptors();
 
   Handle<DescriptorArray> descriptors =
@@ -423,7 +425,7 @@ bool AddDescriptorsByTemplate(
     Handle<NumberDictionary> elements_dictionary_template,
     Handle<FixedArray> computed_properties, Handle<JSObject> receiver,
     bool install_name_accessor,
-    Arguments& args) {  // NOLINT(runtime/references)
+    RuntimeArguments& args) {  // NOLINT(runtime/references)
   int computed_properties_length = computed_properties->length();
 
   // Shallow-copy properties template.
@@ -511,7 +513,7 @@ bool InitClassPrototype(Isolate* isolate,
                         Handle<JSObject> prototype,
                         Handle<HeapObject> prototype_parent,
                         Handle<JSFunction> constructor,
-                        Arguments& args) {  // NOLINT(runtime/references)
+                        RuntimeArguments& args) {  // NOLINT(runtime/references)
   Handle<Map> map(prototype->map(), isolate);
   map = Map::CopyDropDescriptors(isolate, map);
   map->set_is_prototype_map(true);
@@ -555,11 +557,10 @@ bool InitClassPrototype(Isolate* isolate,
   }
 }
 
-bool InitClassConstructor(Isolate* isolate,
-                          Handle<ClassBoilerplate> class_boilerplate,
-                          Handle<HeapObject> constructor_parent,
-                          Handle<JSFunction> constructor,
-                          Arguments& args) {  // NOLINT(runtime/references)
+bool InitClassConstructor(
+    Isolate* isolate, Handle<ClassBoilerplate> class_boilerplate,
+    Handle<HeapObject> constructor_parent, Handle<JSFunction> constructor,
+    RuntimeArguments& args) {  // NOLINT(runtime/references)
   Handle<Map> map(constructor->map(), isolate);
   map = Map::CopyDropDescriptors(isolate, map);
   DCHECK(map->is_prototype_map());
@@ -611,7 +612,7 @@ bool InitClassConstructor(Isolate* isolate,
 MaybeHandle<Object> DefineClass(
     Isolate* isolate, Handle<ClassBoilerplate> class_boilerplate,
     Handle<Object> super_class, Handle<JSFunction> constructor,
-    Arguments& args) {  // NOLINT(runtime/references)
+    RuntimeArguments& args) {  // NOLINT(runtime/references)
   Handle<Object> prototype_parent;
   Handle<HeapObject> constructor_parent;
 
@@ -661,11 +662,14 @@ MaybeHandle<Object> DefineClass(
     return MaybeHandle<Object>();
   }
   if (FLAG_trace_maps) {
+    Handle<Map> empty_map;
+    LOG(isolate,
+        MapEvent("InitialMap", empty_map, handle(constructor->map(), isolate),
+                 "init class constructor",
+                 handle(constructor->shared().DebugName(), isolate)));
     LOG(isolate,
-        MapEvent("InitialMap", Map(), constructor->map(),
-                 "init class constructor", constructor->shared().DebugName()));
-    LOG(isolate, MapEvent("InitialMap", Map(), prototype->map(),
-                          "init class prototype"));
+        MapEvent("InitialMap", empty_map, handle(prototype->map(), isolate),
+                 "init class prototype"));
   }
 
   return prototype;
diff --git a/deps/v8/src/runtime/runtime-compiler.cc b/deps/v8/src/runtime/runtime-compiler.cc
index 29ad7755b9..93733fe90f 100644
--- a/deps/v8/src/runtime/runtime-compiler.cc
+++ b/deps/v8/src/runtime/runtime-compiler.cc
@@ -142,6 +142,7 @@ RUNTIME_FUNCTION(Runtime_InstantiateAsmJs) {
   DCHECK(function->code() ==
          isolate->builtins()->builtin(Builtins::kInstantiateAsmJs));
   function->set_code(isolate->builtins()->builtin(Builtins::kCompileLazy));
+  DCHECK(!isolate->has_pending_exception());
   return Smi::zero();
 }
 
@@ -252,9 +253,10 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
   Handle<JSFunction> function(frame->function(), isolate);
   if (IsSuitableForOnStackReplacement(isolate, function)) {
     if (FLAG_trace_osr) {
-      PrintF("[OSR - Compiling: ");
-      function->PrintName();
-      PrintF(" at AST id %d]\n", ast_id.ToInt());
+      CodeTracer::Scope scope(isolate->GetCodeTracer());
+      PrintF(scope.file(), "[OSR - Compiling: ");
+      function->PrintName(scope.file());
+      PrintF(scope.file(), " at AST id %d]\n", ast_id.ToInt());
     }
     maybe_result = Compiler::GetOptimizedCodeForOSR(function, ast_id, frame);
   }
@@ -269,7 +271,9 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
     if (data.OsrPcOffset().value() >= 0) {
       DCHECK(BailoutId(data.OsrBytecodeOffset().value()) == ast_id);
       if (FLAG_trace_osr) {
-        PrintF("[OSR - Entry at AST id %d, offset %d in optimized code]\n",
+        CodeTracer::Scope scope(isolate->GetCodeTracer());
+        PrintF(scope.file(),
+               "[OSR - Entry at AST id %d, offset %d in optimized code]\n",
                ast_id.ToInt(), data.OsrPcOffset().value());
       }
 
@@ -298,9 +302,10 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
         // the next call, otherwise we'd run unoptimized once more and
         // potentially compile for OSR again.
         if (FLAG_trace_osr) {
-          PrintF("[OSR - Re-marking ");
-          function->PrintName();
-          PrintF(" for non-concurrent optimization]\n");
+          CodeTracer::Scope scope(isolate->GetCodeTracer());
+          PrintF(scope.file(), "[OSR - Re-marking ");
+          function->PrintName(scope.file());
+          PrintF(scope.file(), " for non-concurrent optimization]\n");
         }
         function->SetOptimizationMarker(OptimizationMarker::kCompileOptimized);
       }
@@ -310,9 +315,10 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
 
   // Failed.
   if (FLAG_trace_osr) {
-    PrintF("[OSR - Failed: ");
-    function->PrintName();
-    PrintF(" at AST id %d]\n", ast_id.ToInt());
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    PrintF(scope.file(), "[OSR - Failed: ");
+    function->PrintName(scope.file());
+    PrintF(scope.file(), " at AST id %d]\n", ast_id.ToInt());
   }
 
   if (!function->IsOptimized()) {
diff --git a/deps/v8/src/runtime/runtime-debug.cc b/deps/v8/src/runtime/runtime-debug.cc
index a7e6229ff9..0e1b8fd8fa 100644
--- a/deps/v8/src/runtime/runtime-debug.cc
+++ b/deps/v8/src/runtime/runtime-debug.cc
@@ -497,7 +497,7 @@ int ScriptLinePosition(Handle<Script> script, int line) {
     return GetWasmFunctionOffset(script->wasm_native_module()->module(), line);
   }
 
-  Script::InitLineEnds(script);
+  Script::InitLineEnds(script->GetIsolate(), script);
 
   FixedArray line_ends_array = FixedArray::cast(script->line_ends());
   const int line_count = line_ends_array.length();
diff --git a/deps/v8/src/runtime/runtime-internal.cc b/deps/v8/src/runtime/runtime-internal.cc
index 18e6f67c2f..b3d9f26ee5 100644
--- a/deps/v8/src/runtime/runtime-internal.cc
+++ b/deps/v8/src/runtime/runtime-internal.cc
@@ -198,6 +198,15 @@ RUNTIME_FUNCTION(Runtime_ThrowAccessedUninitializedVariable) {
       NewReferenceError(MessageTemplate::kAccessedUninitializedVariable, name));
 }
 
+RUNTIME_FUNCTION(Runtime_NewError) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_INT32_ARG_CHECKED(template_index, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, arg0, 1);
+  MessageTemplate message_template = MessageTemplateFromInt(template_index);
+  return *isolate->factory()->NewError(message_template, arg0);
+}
+
 RUNTIME_FUNCTION(Runtime_NewTypeError) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
@@ -400,6 +409,13 @@ RUNTIME_FUNCTION(Runtime_ThrowIteratorError) {
   return isolate->Throw(*ErrorUtils::NewIteratorError(isolate, object));
 }
 
+RUNTIME_FUNCTION(Runtime_ThrowSpreadArgIsNullOrUndefined) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  return ErrorUtils::ThrowSpreadArgIsNullOrUndefinedError(isolate, object);
+}
+
 RUNTIME_FUNCTION(Runtime_ThrowCalledNonCallable) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
diff --git a/deps/v8/src/runtime/runtime-literals.cc b/deps/v8/src/runtime/runtime-literals.cc
index a69f903c67..c38f6e1e4c 100644
--- a/deps/v8/src/runtime/runtime-literals.cc
+++ b/deps/v8/src/runtime/runtime-literals.cc
@@ -589,7 +589,7 @@ RUNTIME_FUNCTION(Runtime_CreateObjectLiteral) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(HeapObject, maybe_vector, 0);
-  CONVERT_SMI_ARG_CHECKED(literals_index, 1);
+  CONVERT_TAGGED_INDEX_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(ObjectBoilerplateDescription, description, 2);
   CONVERT_SMI_ARG_CHECKED(flags, 3);
   Handle<FeedbackVector> vector;
@@ -627,7 +627,7 @@ RUNTIME_FUNCTION(Runtime_CreateArrayLiteral) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(HeapObject, maybe_vector, 0);
-  CONVERT_SMI_ARG_CHECKED(literals_index, 1);
+  CONVERT_TAGGED_INDEX_ARG_CHECKED(literals_index, 1);
   CONVERT_ARG_HANDLE_CHECKED(ArrayBoilerplateDescription, elements, 2);
   CONVERT_SMI_ARG_CHECKED(flags, 3);
   Handle<FeedbackVector> vector;
@@ -645,7 +645,7 @@ RUNTIME_FUNCTION(Runtime_CreateRegExpLiteral) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(HeapObject, maybe_vector, 0);
-  CONVERT_SMI_ARG_CHECKED(index, 1);
+  CONVERT_TAGGED_INDEX_ARG_CHECKED(index, 1);
   CONVERT_ARG_HANDLE_CHECKED(String, pattern, 2);
   CONVERT_SMI_ARG_CHECKED(flags, 3);
 
diff --git a/deps/v8/src/runtime/runtime-object.cc b/deps/v8/src/runtime/runtime-object.cc
index 20f562defd..b93cdf349b 100644
--- a/deps/v8/src/runtime/runtime-object.cc
+++ b/deps/v8/src/runtime/runtime-object.cc
@@ -41,8 +41,19 @@ MaybeHandle<Object> Runtime::GetObjectProperty(Isolate* isolate,
 
   if (!it.IsFound() && key->IsSymbol() &&
       Symbol::cast(*key).is_private_name()) {
-    Handle<Object> name_string(Symbol::cast(*key).description(), isolate);
-    DCHECK(name_string->IsString());
+    Handle<Symbol> sym = Handle<Symbol>::cast(key);
+    Handle<Object> name(sym->description(), isolate);
+    DCHECK(name->IsString());
+    Handle<String> name_string = Handle<String>::cast(name);
+    if (sym->IsPrivateBrand()) {
+      Handle<String> class_name = (name_string->length() == 0)
+                                      ? isolate->factory()->anonymous_string()
+                                      : name_string;
+      THROW_NEW_ERROR(isolate,
+                      NewTypeError(MessageTemplate::kInvalidPrivateBrand,
+                                   class_name, object),
+                      Object);
+    }
     THROW_NEW_ERROR(isolate,
                     NewTypeError(MessageTemplate::kInvalidPrivateMemberRead,
                                  name_string, object),
@@ -885,7 +896,7 @@ RUNTIME_FUNCTION(Runtime_DefineDataPropertyInLiteral) {
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
   CONVERT_SMI_ARG_CHECKED(flag, 3);
   CONVERT_ARG_HANDLE_CHECKED(HeapObject, maybe_vector, 4);
-  CONVERT_SMI_ARG_CHECKED(index, 5);
+  CONVERT_TAGGED_INDEX_ARG_CHECKED(index, 5);
 
   if (!maybe_vector->IsUndefined()) {
     DCHECK(maybe_vector->IsFeedbackVector());
diff --git a/deps/v8/src/runtime/runtime-operators.cc b/deps/v8/src/runtime/runtime-operators.cc
index 272502b69f..fd5298077e 100644
--- a/deps/v8/src/runtime/runtime-operators.cc
+++ b/deps/v8/src/runtime/runtime-operators.cc
@@ -56,6 +56,14 @@ RUNTIME_FUNCTION(Runtime_StrictNotEqual) {
   return isolate->heap()->ToBoolean(!x.StrictEquals(y));
 }
 
+RUNTIME_FUNCTION(Runtime_ReferenceEqual) {
+  SealHandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_CHECKED(Object, x, 0);
+  CONVERT_ARG_CHECKED(Object, y, 1);
+  return isolate->heap()->ToBoolean(x == y);
+}
+
 RUNTIME_FUNCTION(Runtime_LessThan) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
diff --git a/deps/v8/src/runtime/runtime-proxy.cc b/deps/v8/src/runtime/runtime-proxy.cc
index afdfa98b0c..038aeb4369 100644
--- a/deps/v8/src/runtime/runtime-proxy.cc
+++ b/deps/v8/src/runtime/runtime-proxy.cc
@@ -15,6 +15,26 @@
 namespace v8 {
 namespace internal {
 
+RUNTIME_FUNCTION(Runtime_IsJSProxy) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj.IsJSProxy());
+}
+
+RUNTIME_FUNCTION(Runtime_JSProxyGetHandler) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
+  return proxy.handler();
+}
+
+RUNTIME_FUNCTION(Runtime_JSProxyGetTarget) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
+  return proxy.target();
+}
 
 RUNTIME_FUNCTION(Runtime_GetPropertyWithReceiver) {
   HandleScope scope(isolate);
diff --git a/deps/v8/src/runtime/runtime-scopes.cc b/deps/v8/src/runtime/runtime-scopes.cc
index 5a588cc917..52abeef583 100644
--- a/deps/v8/src/runtime/runtime-scopes.cc
+++ b/deps/v8/src/runtime/runtime-scopes.cc
@@ -45,11 +45,10 @@ Object ThrowRedeclarationError(Isolate* isolate, Handle<String> name,
 }
 
 // May throw a RedeclarationError.
-Object DeclareGlobal(
-    Isolate* isolate, Handle<JSGlobalObject> global, Handle<String> name,
-    Handle<Object> value, PropertyAttributes attr, bool is_var,
-    RedeclarationType redeclaration_type,
-    Handle<FeedbackVector> feedback_vector = Handle<FeedbackVector>()) {
+Object DeclareGlobal(Isolate* isolate, Handle<JSGlobalObject> global,
+                     Handle<String> name, Handle<Object> value,
+                     PropertyAttributes attr, bool is_var,
+                     RedeclarationType redeclaration_type) {
   Handle<ScriptContextTable> script_contexts(
       global->native_context().script_context_table(), isolate);
   ScriptContextTable::LookupResult lookup;
@@ -118,20 +117,70 @@ Object DeclareGlobal(
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-Object DeclareGlobals(Isolate* isolate, Handle<FixedArray> declarations,
-                      Handle<JSFunction> closure) {
+}  // namespace
+
+RUNTIME_FUNCTION(Runtime_DeclareModuleExports) {
   HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+
+  CONVERT_ARG_HANDLE_CHECKED(FixedArray, declarations, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, closure, 1);
+
+  Handle<ClosureFeedbackCellArray> closure_feedback_cell_array =
+      Handle<ClosureFeedbackCellArray>::null();
+  if (closure->has_feedback_vector()) {
+    closure_feedback_cell_array = Handle<ClosureFeedbackCellArray>(
+        closure->feedback_vector().closure_feedback_cell_array(), isolate);
+  } else {
+    closure_feedback_cell_array = Handle<ClosureFeedbackCellArray>(
+        closure->closure_feedback_cell_array(), isolate);
+  }
+
+  Handle<Context> context(isolate->context(), isolate);
+  DCHECK(context->IsModuleContext());
+  Handle<FixedArray> exports(
+      SourceTextModule::cast(context->extension()).regular_exports(), isolate);
+
+  int length = declarations->length();
+  FOR_WITH_HANDLE_SCOPE(isolate, int, i = 0, i, i < length, i++, {
+    Object decl = declarations->get(i);
+    int index;
+    Object value;
+    if (decl.IsSmi()) {
+      index = Smi::ToInt(decl);
+      value = ReadOnlyRoots(isolate).the_hole_value();
+    } else {
+      Handle<SharedFunctionInfo> sfi(
+          SharedFunctionInfo::cast(declarations->get(i)), isolate);
+      int feedback_index = Smi::ToInt(declarations->get(++i));
+      index = Smi::ToInt(declarations->get(++i));
+      Handle<FeedbackCell> feedback_cell =
+          closure_feedback_cell_array->GetFeedbackCell(feedback_index);
+      value = *isolate->factory()->NewFunctionFromSharedFunctionInfo(
+          sfi, context, feedback_cell, AllocationType::kOld);
+    }
+
+    Cell::cast(exports->get(index - 1)).set_value(value);
+  });
+
+  return ReadOnlyRoots(isolate).undefined_value();
+}
+
+RUNTIME_FUNCTION(Runtime_DeclareGlobals) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+
+  CONVERT_ARG_HANDLE_CHECKED(FixedArray, declarations, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, closure, 1);
+
   Handle<JSGlobalObject> global(isolate->global_object());
   Handle<Context> context(isolate->context(), isolate);
 
-  Handle<FeedbackVector> feedback_vector = Handle<FeedbackVector>::null();
   Handle<ClosureFeedbackCellArray> closure_feedback_cell_array =
       Handle<ClosureFeedbackCellArray>::null();
   if (closure->has_feedback_vector()) {
-    feedback_vector =
-        Handle<FeedbackVector>(closure->feedback_vector(), isolate);
     closure_feedback_cell_array = Handle<ClosureFeedbackCellArray>(
-        feedback_vector->closure_feedback_cell_array(), isolate);
+        closure->feedback_vector().closure_feedback_cell_array(), isolate);
   } else {
     closure_feedback_cell_array = Handle<ClosureFeedbackCellArray>(
         closure->closure_feedback_cell_array(), isolate);
@@ -168,27 +217,14 @@ Object DeclareGlobals(Isolate* isolate, Handle<FixedArray> declarations,
 
     // ES#sec-globaldeclarationinstantiation 5.d:
     // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-    Object result =
-        DeclareGlobal(isolate, global, name, value, attr, is_var,
-                      RedeclarationType::kSyntaxError, feedback_vector);
+    Object result = DeclareGlobal(isolate, global, name, value, attr, is_var,
+                                  RedeclarationType::kSyntaxError);
     if (isolate->has_pending_exception()) return result;
   });
 
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-}  // namespace
-
-RUNTIME_FUNCTION(Runtime_DeclareGlobals) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-
-  CONVERT_ARG_HANDLE_CHECKED(FixedArray, declarations, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, closure, 1);
-
-  return DeclareGlobals(isolate, declarations, closure);
-}
-
 namespace {
 
 Object DeclareEvalHelper(Isolate* isolate, Handle<String> name,
@@ -619,19 +655,6 @@ RUNTIME_FUNCTION(Runtime_PushWithContext) {
   return *context;
 }
 
-RUNTIME_FUNCTION(Runtime_PushModuleContext) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(2, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(SourceTextModule, module, 0);
-  CONVERT_ARG_HANDLE_CHECKED(ScopeInfo, scope_info, 1);
-
-  Handle<NativeContext> outer(NativeContext::cast(isolate->context()), isolate);
-  Handle<Context> context =
-      isolate->factory()->NewModuleContext(module, outer, scope_info);
-  isolate->set_context(*context);
-  return *context;
-}
-
 RUNTIME_FUNCTION(Runtime_PushCatchContext) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
diff --git a/deps/v8/src/runtime/runtime-test.cc b/deps/v8/src/runtime/runtime-test.cc
index fb06a8b8f9..220a4a473c 100644
--- a/deps/v8/src/runtime/runtime-test.cc
+++ b/deps/v8/src/runtime/runtime-test.cc
@@ -91,8 +91,7 @@ v8::Local<v8::Value> NewRangeException(v8::Isolate* isolate,
                                        const char* message) {
   return v8::Exception::RangeError(
       v8::String::NewFromOneByte(isolate,
-                                 reinterpret_cast<const uint8_t*>(message),
-                                 v8::NewStringType::kNormal)
+                                 reinterpret_cast<const uint8_t*>(message))
           .ToLocalChecked());
 }
 
@@ -449,9 +448,10 @@ RUNTIME_FUNCTION(Runtime_OptimizeOsr) {
   // Ensure that the function is marked for non-concurrent optimization, so that
   // subsequent runs don't also optimize.
   if (FLAG_trace_osr) {
-    PrintF("[OSR - OptimizeOsr marking ");
-    function->ShortPrint();
-    PrintF(" for non-concurrent optimization]\n");
+    CodeTracer::Scope scope(isolate->GetCodeTracer());
+    PrintF(scope.file(), "[OSR - OptimizeOsr marking ");
+    function->ShortPrint(scope.file());
+    PrintF(scope.file(), " for non-concurrent optimization]\n");
   }
   JSFunction::EnsureFeedbackVector(function);
   function->MarkForOptimization(ConcurrencyMode::kNotConcurrent);
@@ -730,7 +730,7 @@ RUNTIME_FUNCTION(Runtime_SimulateNewspaceFull) {
   HandleScope scope(isolate);
   Heap* heap = isolate->heap();
   NewSpace* space = heap->new_space();
-  AlwaysAllocateScope always_allocate(heap);
+  AlwaysAllocateScopeForTesting always_allocate(heap);
   do {
     FillUpOneNewSpacePage(isolate, heap);
   } while (space->AddFreshPage());
diff --git a/deps/v8/src/runtime/runtime-utils.h b/deps/v8/src/runtime/runtime-utils.h
index 2d6fbc585f..170c0bcdbc 100644
--- a/deps/v8/src/runtime/runtime-utils.h
+++ b/deps/v8/src/runtime/runtime-utils.h
@@ -36,9 +36,19 @@ namespace internal {
 
 // Cast the given argument to a Smi and store its value in an int variable
 // with the given name.  If the argument is not a Smi we crash safely.
-#define CONVERT_SMI_ARG_CHECKED(name, index) \
-  CHECK(args[index].IsSmi());                \
-  int name = args.smi_at(index);
+#define CONVERT_SMI_ARG_CHECKED(name, index)       \
+  CHECK(args[index].IsSmi());                      \
+  int name = args.smi_at(index);                   \
+  /* Ensure we have a Smi and not a TaggedIndex */ \
+  DCHECK_IMPLIES(args[index].IsTaggedIndex(),      \
+                 name == TaggedIndex(args[index].ptr()).value());
+
+// Cast the given argument to a TaggedIndex and store its value in an int
+// variable with the given name.  If the argument is not a TaggedIndex we crash
+// safely.
+#define CONVERT_TAGGED_INDEX_ARG_CHECKED(name, index) \
+  CHECK(args[index].IsTaggedIndex());                 \
+  int name = args.tagged_index_at(index);
 
 // Cast the given argument to a double and store it in a variable with
 // the given name.  If the argument is not a number (as opposed to
diff --git a/deps/v8/src/runtime/runtime-wasm.cc b/deps/v8/src/runtime/runtime-wasm.cc
index 3e0ab34591..f65922064f 100644
--- a/deps/v8/src/runtime/runtime-wasm.cc
+++ b/deps/v8/src/runtime/runtime-wasm.cc
@@ -19,6 +19,7 @@
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-constants.h"
+#include "src/wasm/wasm-debug.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-objects.h"
 #include "src/wasm/wasm-value.h"
@@ -28,15 +29,33 @@ namespace internal {
 
 namespace {
 
+template <typename FrameType, StackFrame::Type... skipped_frame_types>
+class FrameFinder {
+  static_assert(sizeof...(skipped_frame_types) > 0,
+                "Specify at least one frame to skip");
+
+ public:
+  explicit FrameFinder(Isolate* isolate)
+      : frame_iterator_(isolate, isolate->thread_local_top()) {
+    for (auto type : {skipped_frame_types...}) {
+      DCHECK_EQ(type, frame_iterator_.frame()->type());
+      USE(type);
+      frame_iterator_.Advance();
+    }
+    // Type check the frame where the iterator stopped now.
+    DCHECK_NOT_NULL(frame());
+  }
+
+  FrameType* frame() { return FrameType::cast(frame_iterator_.frame()); }
+
+ private:
+  StackFrameIterator frame_iterator_;
+};
+
 WasmInstanceObject GetWasmInstanceOnStackTop(Isolate* isolate) {
-  StackFrameIterator it(isolate, isolate->thread_local_top());
-  // On top: C entry stub.
-  DCHECK_EQ(StackFrame::EXIT, it.frame()->type());
-  it.Advance();
-  // Next: the wasm compiled frame.
-  DCHECK(it.frame()->is_wasm_compiled());
-  WasmCompiledFrame* frame = WasmCompiledFrame::cast(it.frame());
-  return frame->wasm_instance();
+  return FrameFinder<WasmCompiledFrame, StackFrame::EXIT>(isolate)
+      .frame()
+      ->wasm_instance();
 }
 
 Context GetNativeContextFromWasmInstanceOnStackTop(Isolate* isolate) {
@@ -58,7 +77,10 @@ class ClearThreadInWasmScope {
 
 Object ThrowWasmError(Isolate* isolate, MessageTemplate message) {
   HandleScope scope(isolate);
-  Handle<Object> error_obj = isolate->factory()->NewWasmRuntimeError(message);
+  Handle<JSObject> error_obj = isolate->factory()->NewWasmRuntimeError(message);
+  JSObject::AddProperty(isolate, error_obj,
+                        isolate->factory()->wasm_uncatchable_symbol(),
+                        isolate->factory()->true_value(), NONE);
   return isolate->Throw(*error_obj);
 }
 }  // namespace
@@ -194,20 +216,15 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
   Handle<WasmInstanceObject> instance;
   Address frame_pointer = 0;
   {
-    StackFrameIterator it(isolate, isolate->thread_local_top());
-    // On top: C entry stub.
-    DCHECK_EQ(StackFrame::EXIT, it.frame()->type());
-    it.Advance();
-    // Next: the wasm interpreter entry.
-    DCHECK_EQ(StackFrame::WASM_INTERPRETER_ENTRY, it.frame()->type());
-    instance = handle(
-        WasmInterpreterEntryFrame::cast(it.frame())->wasm_instance(), isolate);
-    frame_pointer = it.frame()->fp();
+    FrameFinder<WasmInterpreterEntryFrame, StackFrame::EXIT> frame_finder(
+        isolate);
+    instance = handle(frame_finder.frame()->wasm_instance(), isolate);
+    frame_pointer = frame_finder.frame()->fp();
   }
 
   // Reserve buffers for argument and return values.
   DCHECK_GE(instance->module()->functions.size(), func_index);
-  wasm::FunctionSig* sig = instance->module()->functions[func_index].sig;
+  const wasm::FunctionSig* sig = instance->module()->functions[func_index].sig;
   DCHECK_GE(kMaxInt, sig->parameter_count());
   int num_params = static_cast<int>(sig->parameter_count());
   ScopedVector<wasm::WasmValue> wasm_args(num_params);
@@ -221,33 +238,33 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
   Address arg_buf_ptr = arg_buffer;
   for (int i = 0; i < num_params; ++i) {
 #define CASE_ARG_TYPE(type, ctype)                                     \
-  case wasm::type:                                                     \
-    DCHECK_EQ(wasm::ValueTypes::ElementSizeInBytes(sig->GetParam(i)),  \
-              sizeof(ctype));                                          \
+  case wasm::ValueType::type:                                          \
+    DCHECK_EQ(sig->GetParam(i).element_size_bytes(), sizeof(ctype));   \
     wasm_args[i] =                                                     \
         wasm::WasmValue(base::ReadUnalignedValue<ctype>(arg_buf_ptr)); \
     arg_buf_ptr += sizeof(ctype);                                      \
     break;
-    switch (sig->GetParam(i)) {
-      CASE_ARG_TYPE(kWasmI32, uint32_t)
-      CASE_ARG_TYPE(kWasmI64, uint64_t)
-      CASE_ARG_TYPE(kWasmF32, float)
-      CASE_ARG_TYPE(kWasmF64, double)
+    switch (sig->GetParam(i).kind()) {
+      CASE_ARG_TYPE(kI32, uint32_t)
+      CASE_ARG_TYPE(kI64, uint64_t)
+      CASE_ARG_TYPE(kF32, float)
+      CASE_ARG_TYPE(kF64, double)
 #undef CASE_ARG_TYPE
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef: {
-        DCHECK_EQ(wasm::ValueTypes::ElementSizeInBytes(sig->GetParam(i)),
-                  kSystemPointerSize);
-        Handle<Object> ref(base::ReadUnalignedValue<Object>(arg_buf_ptr),
-                           isolate);
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef: {
+        DCHECK_EQ(sig->GetParam(i).element_size_bytes(), kSystemPointerSize);
+        Handle<Object> ref(
+            Object(base::ReadUnalignedValue<Address>(arg_buf_ptr)), isolate);
         DCHECK_IMPLIES(sig->GetParam(i) == wasm::kWasmNullRef, ref->IsNull());
         wasm_args[i] = wasm::WasmValue(ref);
         arg_buf_ptr += kSystemPointerSize;
         break;
       }
-      default:
+      case wasm::ValueType::kStmt:
+      case wasm::ValueType::kS128:
+      case wasm::ValueType::kBottom:
         UNREACHABLE();
     }
   }
@@ -275,24 +292,22 @@ RUNTIME_FUNCTION(Runtime_WasmRunInterpreter) {
   arg_buf_ptr = arg_buffer;
   for (int i = 0; i < num_returns; ++i) {
 #define CASE_RET_TYPE(type, ctype)                                           \
-  case wasm::type:                                                           \
-    DCHECK_EQ(wasm::ValueTypes::ElementSizeInBytes(sig->GetReturn(i)),       \
-              sizeof(ctype));                                                \
+  case wasm::ValueType::type:                                                \
+    DCHECK_EQ(sig->GetReturn(i).element_size_bytes(), sizeof(ctype));        \
     base::WriteUnalignedValue<ctype>(arg_buf_ptr, wasm_rets[i].to<ctype>()); \
     arg_buf_ptr += sizeof(ctype);                                            \
     break;
-    switch (sig->GetReturn(i)) {
-      CASE_RET_TYPE(kWasmI32, uint32_t)
-      CASE_RET_TYPE(kWasmI64, uint64_t)
-      CASE_RET_TYPE(kWasmF32, float)
-      CASE_RET_TYPE(kWasmF64, double)
+    switch (sig->GetReturn(i).kind()) {
+      CASE_RET_TYPE(kI32, uint32_t)
+      CASE_RET_TYPE(kI64, uint64_t)
+      CASE_RET_TYPE(kF32, float)
+      CASE_RET_TYPE(kF64, double)
 #undef CASE_RET_TYPE
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef: {
-        DCHECK_EQ(wasm::ValueTypes::ElementSizeInBytes(sig->GetReturn(i)),
-                  kSystemPointerSize);
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef: {
+        DCHECK_EQ(sig->GetReturn(i).element_size_bytes(), kSystemPointerSize);
         DCHECK_IMPLIES(sig->GetReturn(i) == wasm::kWasmNullRef,
                        wasm_rets[i].to_anyref()->IsNull());
         base::WriteUnalignedValue<Object>(arg_buf_ptr,
@@ -333,13 +348,8 @@ RUNTIME_FUNCTION(Runtime_WasmCompileLazy) {
   ClearThreadInWasmScope flag_scope;
 
 #ifdef DEBUG
-  StackFrameIterator it(isolate, isolate->thread_local_top());
-  // On top: C entry stub.
-  DCHECK_EQ(StackFrame::EXIT, it.frame()->type());
-  it.Advance();
-  // Next: the wasm lazy compile frame.
-  DCHECK_EQ(StackFrame::WASM_COMPILE_LAZY, it.frame()->type());
-  DCHECK_EQ(*instance, WasmCompileLazyFrame::cast(it.frame())->wasm_instance());
+  FrameFinder<WasmCompileLazyFrame, StackFrame::EXIT> frame_finder(isolate);
+  DCHECK_EQ(*instance, frame_finder.frame()->wasm_instance());
 #endif
 
   DCHECK(isolate->context().is_null());
@@ -372,6 +382,7 @@ Handle<JSArrayBuffer> getSharedArrayBuffer(Handle<WasmInstanceObject> instance,
 }
 
 RUNTIME_FUNCTION(Runtime_WasmAtomicNotify) {
+  ClearThreadInWasmScope clear_wasm_flag;
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
@@ -382,42 +393,35 @@ RUNTIME_FUNCTION(Runtime_WasmAtomicNotify) {
   return FutexEmulation::Wake(array_buffer, address, count);
 }
 
-double WaitTimeoutInMs(double timeout_ns) {
-  return timeout_ns < 0
-             ? V8_INFINITY
-             : timeout_ns / (base::Time::kNanosecondsPerMicrosecond *
-                             base::Time::kMicrosecondsPerMillisecond);
-}
-
 RUNTIME_FUNCTION(Runtime_WasmI32AtomicWait) {
+  ClearThreadInWasmScope clear_wasm_flag;
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
   CONVERT_NUMBER_CHECKED(uint32_t, address, Uint32, args[1]);
   CONVERT_NUMBER_CHECKED(int32_t, expected_value, Int32, args[2]);
-  CONVERT_DOUBLE_ARG_CHECKED(timeout_ns, 3);
-  double timeout_ms = WaitTimeoutInMs(timeout_ns);
+  CONVERT_ARG_HANDLE_CHECKED(BigInt, timeout_ns, 3);
+
   Handle<JSArrayBuffer> array_buffer =
       getSharedArrayBuffer(instance, isolate, address);
-  return FutexEmulation::Wait32(isolate, array_buffer, address, expected_value,
-                                timeout_ms);
+  return FutexEmulation::WaitWasm32(isolate, array_buffer, address,
+                                    expected_value, timeout_ns->AsInt64());
 }
 
 RUNTIME_FUNCTION(Runtime_WasmI64AtomicWait) {
+  ClearThreadInWasmScope clear_wasm_flag;
   HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
+  DCHECK_EQ(4, args.length());
   CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
   CONVERT_NUMBER_CHECKED(uint32_t, address, Uint32, args[1]);
-  CONVERT_NUMBER_CHECKED(uint32_t, expected_value_high, Uint32, args[2]);
-  CONVERT_NUMBER_CHECKED(uint32_t, expected_value_low, Uint32, args[3]);
-  CONVERT_DOUBLE_ARG_CHECKED(timeout_ns, 4);
-  int64_t expected_value = (static_cast<uint64_t>(expected_value_high) << 32) |
-                           static_cast<uint64_t>(expected_value_low);
-  double timeout_ms = WaitTimeoutInMs(timeout_ns);
+  CONVERT_ARG_HANDLE_CHECKED(BigInt, expected_value, 2);
+  CONVERT_ARG_HANDLE_CHECKED(BigInt, timeout_ns, 3);
+
   Handle<JSArrayBuffer> array_buffer =
       getSharedArrayBuffer(instance, isolate, address);
-  return FutexEmulation::Wait64(isolate, array_buffer, address, expected_value,
-                                timeout_ms);
+  return FutexEmulation::WaitWasm64(isolate, array_buffer, address,
+                                    expected_value->AsInt64(),
+                                    timeout_ns->AsInt64());
 }
 
 namespace {
@@ -497,17 +501,15 @@ RUNTIME_FUNCTION(Runtime_WasmFunctionTableSet) {
 
 RUNTIME_FUNCTION(Runtime_WasmTableInit) {
   HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
-  auto instance =
-      Handle<WasmInstanceObject>(GetWasmInstanceOnStackTop(isolate), isolate);
-  CONVERT_UINT32_ARG_CHECKED(table_index, 0);
-  CONVERT_UINT32_ARG_CHECKED(elem_segment_index, 1);
-  CONVERT_UINT32_ARG_CHECKED(dst, 2);
-  CONVERT_UINT32_ARG_CHECKED(src, 3);
-  CONVERT_UINT32_ARG_CHECKED(count, 4);
+  DCHECK_EQ(6, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
+  CONVERT_UINT32_ARG_CHECKED(table_index, 1);
+  CONVERT_UINT32_ARG_CHECKED(elem_segment_index, 2);
+  CONVERT_UINT32_ARG_CHECKED(dst, 3);
+  CONVERT_UINT32_ARG_CHECKED(src, 4);
+  CONVERT_UINT32_ARG_CHECKED(count, 5);
 
-  DCHECK(isolate->context().is_null());
-  isolate->set_context(instance->native_context());
+  DCHECK(!isolate->context().is_null());
 
   bool oob = !WasmInstanceObject::InitTableEntries(
       isolate, instance, table_index, elem_segment_index, dst, src, count);
@@ -517,16 +519,15 @@ RUNTIME_FUNCTION(Runtime_WasmTableInit) {
 
 RUNTIME_FUNCTION(Runtime_WasmTableCopy) {
   HandleScope scope(isolate);
-  DCHECK_EQ(5, args.length());
-  DCHECK(isolate->context().is_null());
-  isolate->set_context(GetNativeContextFromWasmInstanceOnStackTop(isolate));
-  auto instance =
-      Handle<WasmInstanceObject>(GetWasmInstanceOnStackTop(isolate), isolate);
-  CONVERT_UINT32_ARG_CHECKED(table_dst_index, 0);
-  CONVERT_UINT32_ARG_CHECKED(table_src_index, 1);
-  CONVERT_UINT32_ARG_CHECKED(dst, 2);
-  CONVERT_UINT32_ARG_CHECKED(src, 3);
-  CONVERT_UINT32_ARG_CHECKED(count, 4);
+  DCHECK_EQ(6, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(WasmInstanceObject, instance, 0);
+  CONVERT_UINT32_ARG_CHECKED(table_dst_index, 1);
+  CONVERT_UINT32_ARG_CHECKED(table_src_index, 2);
+  CONVERT_UINT32_ARG_CHECKED(dst, 3);
+  CONVERT_UINT32_ARG_CHECKED(src, 4);
+  CONVERT_UINT32_ARG_CHECKED(count, 5);
+
+  DCHECK(!isolate->context().is_null());
 
   bool oob = !WasmInstanceObject::CopyTableEntries(
       isolate, instance, table_dst_index, table_src_index, dst, src, count);
@@ -576,11 +577,11 @@ RUNTIME_FUNCTION(Runtime_WasmTableFill) {
   // Even when table.fill goes out-of-bounds, as many entries as possible are
   // put into the table. Only afterwards we trap.
   uint32_t fill_count = std::min(count, table_size - start);
-  WasmTableObject::Fill(isolate, table, start, value, fill_count);
-
   if (fill_count < count) {
     return ThrowTableOutOfBounds(isolate, instance);
   }
+  WasmTableObject::Fill(isolate, table, start, value, fill_count);
+
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
@@ -602,5 +603,55 @@ RUNTIME_FUNCTION(Runtime_WasmNewMultiReturnJSArray) {
       fixed_array_handle, PACKED_ELEMENTS);
   return *array;
 }
+
+RUNTIME_FUNCTION(Runtime_WasmDebugBreak) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(0, args.length());
+  FrameFinder<WasmCompiledFrame, StackFrame::EXIT, StackFrame::WASM_DEBUG_BREAK>
+      frame_finder(isolate);
+  auto instance = handle(frame_finder.frame()->wasm_instance(), isolate);
+  int position = frame_finder.frame()->position();
+  isolate->set_context(instance->native_context());
+
+  // Enter the debugger.
+  DebugScope debug_scope(isolate->debug());
+
+  const auto undefined = ReadOnlyRoots(isolate).undefined_value();
+  WasmCompiledFrame* frame = frame_finder.frame();
+  auto* debug_info = frame->native_module()->GetDebugInfo();
+  if (debug_info->IsStepping(frame)) {
+    debug_info->ClearStepping();
+    isolate->debug()->ClearStepping();
+    isolate->debug()->OnDebugBreak(isolate->factory()->empty_fixed_array());
+    return undefined;
+  }
+
+  // Check whether we hit a breakpoint.
+  Handle<Script> script(instance->module_object().script(), isolate);
+  Handle<FixedArray> breakpoints;
+  if (WasmScript::CheckBreakPoints(isolate, script, position)
+          .ToHandle(&breakpoints)) {
+    debug_info->ClearStepping();
+    isolate->debug()->ClearStepping();
+    if (isolate->debug()->break_points_active()) {
+      // We hit one or several breakpoints. Notify the debug listeners.
+      isolate->debug()->OnDebugBreak(breakpoints);
+    }
+  } else {
+    // Unused breakpoint. Possible scenarios:
+    // 1. We hit a breakpoint that was already removed,
+    // 2. We hit a stepping breakpoint after resuming,
+    // 3. We hit a stepping breakpoint during a stepOver on a recursive call.
+    // 4. The breakpoint was set in a different isolate.
+    // We can handle the first three cases by simply removing the breakpoint (if
+    // it exists), since this will also recompile the function without the
+    // stepping breakpoints.
+    // TODO(thibaudm/clemensb): handle case 4.
+    debug_info->RemoveBreakpoint(frame->function_index(), position, isolate);
+  }
+
+  return undefined;
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/runtime/runtime.cc b/deps/v8/src/runtime/runtime.cc
index 2bba57f910..e51338ba6d 100644
--- a/deps/v8/src/runtime/runtime.cc
+++ b/deps/v8/src/runtime/runtime.cc
@@ -192,6 +192,34 @@ bool Runtime::MayAllocate(FunctionId id) {
   }
 }
 
+bool Runtime::IsWhitelistedForFuzzing(FunctionId id) {
+  CHECK(FLAG_allow_natives_for_fuzzing);
+  switch (id) {
+    // Runtime functions whitelisted for all fuzzers. Only add functions that
+    // help increase coverage.
+    case Runtime::kArrayBufferDetach:
+    case Runtime::kDeoptimizeFunction:
+    case Runtime::kDeoptimizeNow:
+    case Runtime::kEnableCodeLoggingForTesting:
+    case Runtime::kGetUndetectable:
+    case Runtime::kNeverOptimizeFunction:
+    case Runtime::kOptimizeFunctionOnNextCall:
+    case Runtime::kOptimizeOsr:
+    case Runtime::kPrepareFunctionForOptimization:
+    case Runtime::kSetAllocationTimeout:
+    case Runtime::kSimulateNewspaceFull:
+      return true;
+    // Runtime functions only permitted for non-differential fuzzers.
+    // This list may contain functions performing extra checks or returning
+    // different values in the context of different flags passed to V8.
+    case Runtime::kHeapObjectVerify:
+    case Runtime::kIsBeingInterpreted:
+      return !FLAG_allow_natives_for_differential_fuzzing;
+    default:
+      return false;
+  }
+}
+
 const Runtime::Function* Runtime::FunctionForName(const unsigned char* name,
                                                   int length) {
   base::CallOnce(&initialize_function_name_map_once,
diff --git a/deps/v8/src/runtime/runtime.h b/deps/v8/src/runtime/runtime.h
index c9c4dd5931..57500be510 100644
--- a/deps/v8/src/runtime/runtime.h
+++ b/deps/v8/src/runtime/runtime.h
@@ -219,6 +219,7 @@ namespace internal {
   F(GetTemplateObject, 3, 1)                         \
   F(IncrementUseCounter, 1, 1)                       \
   F(BytecodeBudgetInterrupt, 1, 1)                   \
+  F(NewError, 2, 1)                                  \
   F(NewReferenceError, 2, 1)                         \
   F(NewSyntaxError, 2, 1)                            \
   F(NewTypeError, 2, 1)                              \
@@ -238,6 +239,7 @@ namespace internal {
   F(ThrowInvalidStringLength, 0, 1)                  \
   F(ThrowInvalidTypedArrayAlignment, 2, 1)           \
   F(ThrowIteratorError, 1, 1)                        \
+  F(ThrowSpreadArgIsNullOrUndefined, 1, 1)           \
   F(ThrowIteratorResultNotAnObject, 1, 1)            \
   F(ThrowNotConstructor, 1, 1)                       \
   F(ThrowPatternAssignmentNonCoercible, 1, 1)        \
@@ -348,7 +350,8 @@ namespace internal {
   F(LessThanOrEqual, 2, 1)                 \
   F(NotEqual, 2, 1)                        \
   F(StrictEqual, 2, 1)                     \
-  F(StrictNotEqual, 2, 1)
+  F(StrictNotEqual, 2, 1)                  \
+  F(ReferenceEqual, 2, 1)
 
 #define FOR_EACH_INTRINSIC_PROMISE(F, I) \
   F(EnqueueMicrotask, 1, 1)              \
@@ -371,6 +374,9 @@ namespace internal {
   F(CheckProxyHasTrapResult, 2, 1)     \
   F(CheckProxyDeleteTrapResult, 2, 1)  \
   F(GetPropertyWithReceiver, 3, 1)     \
+  F(IsJSProxy, 1, 1)                   \
+  F(JSProxyGetHandler, 1, 1)           \
+  F(JSProxyGetTarget, 1, 1)            \
   F(SetPropertyWithReceiver, 4, 1)
 
 #define FOR_EACH_INTRINSIC_REGEXP(F, I)             \
@@ -387,6 +393,7 @@ namespace internal {
   F(DeclareEvalFunction, 2, 1)              \
   F(DeclareEvalVar, 1, 1)                   \
   F(DeclareGlobals, 2, 1)                   \
+  F(DeclareModuleExports, 2, 1)             \
   F(DeleteLookupSlot, 1, 1)                 \
   F(LoadLookupSlot, 1, 1)                   \
   F(LoadLookupSlotInsideTypeof, 1, 1)       \
@@ -401,7 +408,6 @@ namespace internal {
   F(NewStrictArguments, 1, 1)               \
   F(PushBlockContext, 1, 1)                 \
   F(PushCatchContext, 2, 1)                 \
-  F(PushModuleContext, 2, 1)                \
   F(PushWithContext, 2, 1)                  \
   F(StoreGlobalNoHoleCheckForReplLet, 2, 1) \
   F(StoreLookupSlot_Sloppy, 2, 1)           \
@@ -563,14 +569,15 @@ namespace internal {
   F(WasmRefFunc, 1, 1)                  \
   F(WasmFunctionTableGet, 3, 1)         \
   F(WasmFunctionTableSet, 4, 1)         \
-  F(WasmTableInit, 5, 1)                \
-  F(WasmTableCopy, 5, 1)                \
+  F(WasmTableInit, 6, 1)                \
+  F(WasmTableCopy, 6, 1)                \
   F(WasmTableGrow, 3, 1)                \
   F(WasmTableFill, 4, 1)                \
   F(WasmIsValidFuncRefValue, 1, 1)      \
   F(WasmCompileLazy, 2, 1)              \
   F(WasmNewMultiReturnFixedArray, 1, 1) \
-  F(WasmNewMultiReturnJSArray, 1, 1)
+  F(WasmNewMultiReturnJSArray, 1, 1)    \
+  F(WasmDebugBreak, 0, 1)
 
 #define FOR_EACH_INTRINSIC_RETURN_PAIR_IMPL(F, I) \
   F(DebugBreakOnBytecode, 1, 2)                   \
@@ -709,10 +716,14 @@ class Runtime : public AllStatic {
   // sentinel, always.
   static bool IsNonReturning(FunctionId id);
 
-  // Check if a runtime function with the given {id}  may trigger a heap
+  // Check if a runtime function with the given {id} may trigger a heap
   // allocation.
   static bool MayAllocate(FunctionId id);
 
+  // Check if a runtime function with the given {id} is whitelisted for
+  // using it with fuzzers.
+  static bool IsWhitelistedForFuzzing(FunctionId id);
+
   // Get the intrinsic function with the given name.
   static const Function* FunctionForName(const unsigned char* name, int length);
 
diff --git a/deps/v8/src/snapshot/DEPS b/deps/v8/src/snapshot/DEPS
index 70ef55e340..93f17c9286 100644
--- a/deps/v8/src/snapshot/DEPS
+++ b/deps/v8/src/snapshot/DEPS
@@ -2,6 +2,9 @@ specific_include_rules = {
   "mksnapshot\.cc": [
     "+include/libplatform/libplatform.h",
   ],
+  "snapshot-compression.cc": [
+    "+third_party/zlib",
+  ],
   "serializer-common.cc": [
     "+third_party/zlib",
   ],
diff --git a/deps/v8/src/snapshot/code-serializer.cc b/deps/v8/src/snapshot/code-serializer.cc
index 30098bab46..d155313872 100644
--- a/deps/v8/src/snapshot/code-serializer.cc
+++ b/deps/v8/src/snapshot/code-serializer.cc
@@ -190,12 +190,12 @@ void CodeSerializer::SerializeObject(HeapObject obj) {
   // bytecode array stored within the InterpreterData, which is the important
   // information. On deserialization we'll create our code objects again, if
   // --interpreted-frames-native-stack is on. See v8:9122 for more context
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
   if (V8_UNLIKELY(FLAG_interpreted_frames_native_stack) &&
       obj.IsInterpreterData()) {
     obj = InterpreterData::cast(obj).bytecode_array();
   }
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
   // Past this point we should not see any (context-specific) maps anymore.
   CHECK(!obj.IsMap());
@@ -215,7 +215,7 @@ void CodeSerializer::SerializeGeneric(HeapObject heap_object) {
   serializer.Serialize();
 }
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
 // NOTE(mmarchini): when FLAG_interpreted_frames_native_stack is on, we want to
 // create duplicates of InterpreterEntryTrampoline for the deserialized
 // functions, otherwise we'll call the builtin IET for those functions (which
@@ -255,7 +255,7 @@ void CreateInterpreterDataForDeserializedCode(Isolate* isolate,
                             column_num));
   }
 }
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
 MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
     Isolate* isolate, ScriptData* cached_data, Handle<String> source,
@@ -301,11 +301,11 @@ MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
       isolate->is_profiling() ||
       isolate->code_event_dispatcher()->IsListeningToCodeEvents();
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
   if (V8_UNLIKELY(FLAG_interpreted_frames_native_stack))
     CreateInterpreterDataForDeserializedCode(isolate, result,
                                              log_code_creation);
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
   bool needs_source_positions = isolate->NeedsSourcePositionsForProfiling();
 
@@ -323,7 +323,7 @@ MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
                         result->StartPosition(), result->EndPosition(), *name));
     }
     if (log_code_creation) {
-      Script::InitLineEnds(script);
+      Script::InitLineEnds(isolate, script);
 
       SharedFunctionInfo::ScriptIterator iter(isolate, *script);
       for (SharedFunctionInfo info = iter.Next(); !info.is_null();
@@ -350,7 +350,7 @@ MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
 
   if (needs_source_positions) {
     Handle<Script> script(Script::cast(result->script()), isolate);
-    Script::InitLineEnds(script);
+    Script::InitLineEnds(isolate, script);
   }
   return scope.CloseAndEscape(result);
 }
diff --git a/deps/v8/src/snapshot/deserializer-allocator.cc b/deps/v8/src/snapshot/deserializer-allocator.cc
index ed179f6842..e58e7b66ac 100644
--- a/deps/v8/src/snapshot/deserializer-allocator.cc
+++ b/deps/v8/src/snapshot/deserializer-allocator.cc
@@ -45,10 +45,12 @@ Address DeserializerAllocator::AllocateRaw(SnapshotSpace space, int size) {
     int chunk_index = current_chunk_[space_number];
     DCHECK_LE(high_water_[space_number], reservation[chunk_index].end);
 #endif
+#ifndef V8_ENABLE_THIRD_PARTY_HEAP
     if (space == SnapshotSpace::kCode)
       MemoryChunk::FromAddress(address)
           ->GetCodeObjectRegistry()
           ->RegisterNewlyAllocatedCodeObject(address);
+#endif
     return address;
   }
 }
@@ -56,16 +58,22 @@ Address DeserializerAllocator::AllocateRaw(SnapshotSpace space, int size) {
 Address DeserializerAllocator::Allocate(SnapshotSpace space, int size) {
   Address address;
   HeapObject obj;
-  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) {
-    AllocationType type = (space == SnapshotSpace::kCode)
-                              ? AllocationType::kCode
-                              : AllocationType::kYoung;
-    return heap_->DeserializerAllocate(type, size);
-  }
-  // TODO(steveblackburn) The following logic and AllocateRaw() above should
-  // be lifted into Heap, pushing the logic to heap_->DeserializerAllocate().
-  // The implementation below and AllocateRaw() above leak heap abstractions
-  // such as particular structure of heap spaces.
+  // TODO(steveblackburn) Note that the third party heap allocates objects
+  // at reservation time, which means alignment must be acted on at
+  // reservation time, not here.   Since the current encoding does not
+  // inform the reservation of the alignment, it must be conservatively
+  // aligned.
+  //
+  // A more general approach will be to avoid reservation altogether, and
+  // instead of chunk index/offset encoding, simply encode backreferences
+  // by index (this can be optimized by applying something like register
+  // allocation to keep the metadata needed to record the in-flight
+  // backreferences minimal).   This has the significant advantage of
+  // abstracting away the details of the memory allocator from this code.
+  // At each allocation, the regular allocator performs allocation,
+  // and a fixed-sized table is used to track and fix all back references.
+  if (V8_ENABLE_THIRD_PARTY_HEAP_BOOL) return AllocateRaw(space, size);
+
   if (next_alignment_ != kWordAligned) {
     const int reserved = size + Heap::GetMaximumFillToAlign(next_alignment_);
     address = AllocateRaw(space, reserved);
diff --git a/deps/v8/src/snapshot/deserializer.cc b/deps/v8/src/snapshot/deserializer.cc
index 127cfae29e..fdb4babe07 100644
--- a/deps/v8/src/snapshot/deserializer.cc
+++ b/deps/v8/src/snapshot/deserializer.cc
@@ -301,8 +301,7 @@ HeapObject Deserializer::PostProcessNewObject(HeapObject obj,
     }
   } else if (obj.IsJSArrayBuffer()) {
     JSArrayBuffer buffer = JSArrayBuffer::cast(obj);
-    buffer.set_extension(nullptr);
-    // Only fixup for the off-heap case. This may trigger GC.
+    // Postpone allocation of backing store to avoid triggering the GC.
     if (buffer.backing_store() != nullptr) {
       new_off_heap_array_buffers_.push_back(handle(buffer, isolate_));
     }
@@ -668,6 +667,7 @@ bool Deserializer::ReadData(TSlot current, TSlot limit,
       }
 
       case kOffHeapBackingStore: {
+        AlwaysAllocateScope scope(isolate->heap());
         int byte_length = source_.GetInt();
         std::unique_ptr<BackingStore> backing_store =
             BackingStore::Allocate(isolate, byte_length, SharedFlag::kNotShared,
@@ -755,8 +755,36 @@ bool Deserializer::ReadData(TSlot current, TSlot limit,
       STATIC_ASSERT(kNumberOfFixedRawData == 32);
       SIXTEEN_CASES(kFixedRawData)
       SIXTEEN_CASES(kFixedRawData + 16) {
-        int size_in_tagged = data - kFixedRawDataStart;
-        source_.CopyRaw(current.ToVoidPtr(), size_in_tagged * kTaggedSize);
+        // This bytecode has become very confusing with recent changes due to
+        // pointer compression. From comments and variable names it implies that
+        // the length unit is words/kPointerSize, but the unit is actually
+        // kTaggedSize since https://chromium-review.googlesource.com/c/1388529.
+        //
+        // Also, contents can be (tagged) Smis or just a raw byte sequence. In
+        // the case of Smis we must be careful when deserializing into full
+        // object slots. It is not valid to deserialize a sequence of >1 Smis
+        // into full object slots in compressed pointer builds.
+        //
+        // Likewise one must pay attention to endianness when deserializing a
+        // smi into a full object slot. That is what the code below is trying to
+        // address.
+        //
+        // The solution below works because we currently never deserialize >1
+        // Smi into full object slots, or raw byte sequences into full object
+        // slots. But those assumptions are fragile.
+        //
+        const int size_in_tagged = data - kFixedRawDataStart;
+        const int size_in_bytes = size_in_tagged * kTaggedSize;
+        Address addr = current.address();
+        DCHECK_IMPLIES(kTaggedSize != TSlot::kSlotDataSize,
+                       size_in_tagged == 1);
+#ifdef V8_TARGET_BIG_ENDIAN
+        if (kTaggedSize != TSlot::kSlotDataSize) {
+          // Should only be reached when deserializing a Smi root.
+          addr += kTaggedSize;
+        }
+#endif
+        source_.CopyRaw(reinterpret_cast<void*>(addr), size_in_bytes);
         current += size_in_tagged;
         break;
       }
diff --git a/deps/v8/src/snapshot/deserializer.h b/deps/v8/src/snapshot/deserializer.h
index 871aa6b3a7..62814a881a 100644
--- a/deps/v8/src/snapshot/deserializer.h
+++ b/deps/v8/src/snapshot/deserializer.h
@@ -29,7 +29,7 @@ class Object;
 // of objects found in code.
 #if defined(V8_TARGET_ARCH_MIPS) || defined(V8_TARGET_ARCH_MIPS64) || \
     defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_S390) ||    \
-    V8_EMBEDDED_CONSTANT_POOL
+    defined(V8_TARGET_ARCH_PPC64) || V8_EMBEDDED_CONSTANT_POOL
 #define V8_CODE_EMBEDS_OBJECT_POINTER 1
 #else
 #define V8_CODE_EMBEDS_OBJECT_POINTER 0
diff --git a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-generic.cc b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-generic.cc
index c5e131e3fe..f1d6efc767 100644
--- a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-generic.cc
+++ b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-generic.cc
@@ -118,7 +118,9 @@ int PlatformEmbeddedFileWriterGeneric::HexLiteral(uint64_t value) {
   return fprintf(fp_, "0x%" PRIx64, value);
 }
 
-void PlatformEmbeddedFileWriterGeneric::FilePrologue() {}
+void PlatformEmbeddedFileWriterGeneric::FilePrologue() {
+  // TODO(v8:10026): Add ELF note required for BTI.
+}
 
 void PlatformEmbeddedFileWriterGeneric::DeclareExternalFilename(
     int fileid, const char* filename) {
diff --git a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.cc b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.cc
index 86ac01d6fb..f722ffe4ae 100644
--- a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.cc
+++ b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.cc
@@ -35,15 +35,6 @@ namespace internal {
 // http://infocenter.arm.com/help/topic/com.arm.doc.dui0802b/index.html
 // Microsoft ARM assembler and assembly language docs:
 // https://docs.microsoft.com/en-us/cpp/assembler/arm/arm-assembler-reference
-#if defined(V8_COMPILER_IS_MSVC)
-#if defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_ARM)
-#define V8_ASSEMBLER_IS_MARMASM
-#elif defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_X64)
-#define V8_ASSEMBLER_IS_MASM
-#else
-#error Unknown Windows assembler target architecture.
-#endif
-#endif
 
 // Name mangling.
 // Symbols are prefixed with an underscore on 32-bit architectures.
@@ -64,44 +55,6 @@ namespace internal {
 
 namespace {
 
-const char* DirectiveAsString(DataDirective directive) {
-#if defined(V8_ASSEMBLER_IS_MASM)
-  switch (directive) {
-    case kByte:
-      return "BYTE";
-    case kLong:
-      return "DWORD";
-    case kQuad:
-      return "QWORD";
-    default:
-      UNREACHABLE();
-  }
-#elif defined(V8_ASSEMBLER_IS_MARMASM)
-  switch (directive) {
-    case kByte:
-      return "DCB";
-    case kLong:
-      return "DCDU";
-    case kQuad:
-      return "DCQU";
-    default:
-      UNREACHABLE();
-  }
-#else
-  switch (directive) {
-    case kByte:
-      return ".byte";
-    case kLong:
-      return ".long";
-    case kQuad:
-      return ".quad";
-    case kOcta:
-      return ".octa";
-  }
-  UNREACHABLE();
-#endif
-}
-
 #if defined(V8_OS_WIN_X64)
 
 void WriteUnwindInfoEntry(PlatformEmbeddedFileWriterWin* w,
@@ -308,6 +261,47 @@ void EmitUnwindData(PlatformEmbeddedFileWriterWin* w,
 
 }  // namespace
 
+const char* PlatformEmbeddedFileWriterWin::DirectiveAsString(
+    DataDirective directive) {
+#if defined(V8_COMPILER_IS_MSVC)
+  if (target_arch_ != EmbeddedTargetArch::kArm64) {
+    switch (directive) {
+      case kByte:
+        return "BYTE";
+      case kLong:
+        return "DWORD";
+      case kQuad:
+        return "QWORD";
+      default:
+        UNREACHABLE();
+    }
+  } else {
+    switch (directive) {
+      case kByte:
+        return "DCB";
+      case kLong:
+        return "DCDU";
+      case kQuad:
+        return "DCQU";
+      default:
+        UNREACHABLE();
+    }
+  }
+#else
+  switch (directive) {
+    case kByte:
+      return ".byte";
+    case kLong:
+      return ".long";
+    case kQuad:
+      return ".quad";
+    case kOcta:
+      return ".octa";
+  }
+  UNREACHABLE();
+#endif
+}
+
 void PlatformEmbeddedFileWriterWin::MaybeEmitUnwindData(
     const char* unwind_info_symbol, const char* embedded_blob_data_symbol,
     const EmbeddedData* blob, const void* unwind_infos) {
@@ -328,20 +322,57 @@ void PlatformEmbeddedFileWriterWin::MaybeEmitUnwindData(
 #endif  // V8_OS_WIN64
 }
 
-// Windows, MSVC, not arm/arm64.
+// Windows, MSVC
 // -----------------------------------------------------------------------------
 
-#if defined(V8_ASSEMBLER_IS_MASM)
+#if defined(V8_COMPILER_IS_MSVC)
 
-// For MSVC builds we emit assembly in MASM syntax.
+// For x64 MSVC builds we emit assembly in MASM syntax.
 // See https://docs.microsoft.com/en-us/cpp/assembler/masm/directives-reference.
+// For Arm build, we emit assembly in MARMASM syntax.
+// Note that the same mksnapshot has to be used to compile the host and target.
 
-void PlatformEmbeddedFileWriterWin::SectionText() { fprintf(fp_, ".CODE\n"); }
+// The AARCH64 ABI requires instructions be 4-byte-aligned and Windows does
+// not have a stricter alignment requirement (see the TEXTAREA macro of
+// kxarm64.h in the Windows SDK), so code is 4-byte-aligned.
+// The data fields in the emitted assembly tend to be accessed with 8-byte
+// LDR instructions, so data is 8-byte-aligned.
+//
+// armasm64's warning A4228 states
+//     Alignment value exceeds AREA alignment; alignment not guaranteed
+// To ensure that ALIGN directives are honored, their values are defined as
+// equal to their corresponding AREA's ALIGN attributes.
 
-void PlatformEmbeddedFileWriterWin::SectionData() { fprintf(fp_, ".DATA\n"); }
+#define ARM64_DATA_ALIGNMENT_POWER (3)
+#define ARM64_DATA_ALIGNMENT (1 << ARM64_DATA_ALIGNMENT_POWER)
+#define ARM64_CODE_ALIGNMENT_POWER (2)
+#define ARM64_CODE_ALIGNMENT (1 << ARM64_CODE_ALIGNMENT_POWER)
+
+void PlatformEmbeddedFileWriterWin::SectionText() {
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  AREA |.text|, CODE, ALIGN=%d, READONLY\n",
+            ARM64_CODE_ALIGNMENT_POWER);
+  } else {
+    fprintf(fp_, ".CODE\n");
+  }
+}
+
+void PlatformEmbeddedFileWriterWin::SectionData() {
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  AREA |.data|, DATA, ALIGN=%d, READWRITE\n",
+            ARM64_DATA_ALIGNMENT_POWER);
+  } else {
+    fprintf(fp_, ".DATA\n");
+  }
+}
 
 void PlatformEmbeddedFileWriterWin::SectionRoData() {
-  fprintf(fp_, ".CONST\n");
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  AREA |.rodata|, DATA, ALIGN=%d, READONLY\n",
+            ARM64_DATA_ALIGNMENT_POWER);
+  } else {
+    fprintf(fp_, ".CONST\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareUint32(const char* name,
@@ -359,48 +390,93 @@ void PlatformEmbeddedFileWriterWin::DeclarePointerToSymbol(const char* name,
 }
 
 void PlatformEmbeddedFileWriterWin::StartPdataSection() {
-  fprintf(fp_, "OPTION DOTNAME\n");
-  fprintf(fp_, ".pdata SEGMENT DWORD READ ''\n");
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  AREA |.pdata|, DATA, ALIGN=%d, READONLY\n",
+            ARM64_DATA_ALIGNMENT_POWER);
+  } else {
+    fprintf(fp_, "OPTION DOTNAME\n");
+    fprintf(fp_, ".pdata SEGMENT DWORD READ ''\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::EndPdataSection() {
-  fprintf(fp_, ".pdata ENDS\n");
+  if (target_arch_ != EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, ".pdata ENDS\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::StartXdataSection() {
-  fprintf(fp_, "OPTION DOTNAME\n");
-  fprintf(fp_, ".xdata SEGMENT DWORD READ ''\n");
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  AREA |.xdata|, DATA, ALIGN=%d, READONLY\n",
+            ARM64_DATA_ALIGNMENT_POWER);
+  } else {
+    fprintf(fp_, "OPTION DOTNAME\n");
+    fprintf(fp_, ".xdata SEGMENT DWORD READ ''\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::EndXdataSection() {
-  fprintf(fp_, ".xdata ENDS\n");
+  if (target_arch_ != EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, ".xdata ENDS\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareExternalFunction(const char* name) {
-  fprintf(fp_, "EXTERN %s : PROC\n", name);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  EXTERN %s \n", name);
+  } else {
+    fprintf(fp_, "EXTERN %s : PROC\n", name);
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareRvaToSymbol(const char* name,
                                                        uint64_t offset) {
-  if (offset > 0) {
-    fprintf(fp_, "DD IMAGEREL %s+%llu\n", name, offset);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    if (offset > 0) {
+      fprintf(fp_, "  DCD  %s + %llu\n", name, offset);
+    } else {
+      fprintf(fp_, "  DCD  %s\n", name);
+    }
+    // The default relocation entry generated by MSVC armasm64.exe for DCD
+    // directive is IMAGE_REL_ARM64_ADDR64 which represents relocation for
+    // 64-bit pointer instead of 32-bit RVA. Append RELOC with
+    // IMAGE_REL_ARM64_ADDR32NB(2) to generate correct relocation entry for
+    // 32-bit RVA.
+    fprintf(fp_, "  RELOC 2\n");
   } else {
-    fprintf(fp_, "DD IMAGEREL %s\n", name);
+    if (offset > 0) {
+      fprintf(fp_, "DD IMAGEREL %s+%llu\n", name, offset);
+    } else {
+      fprintf(fp_, "DD IMAGEREL %s\n", name);
+    }
   }
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareSymbolGlobal(const char* name) {
-  fprintf(fp_, "PUBLIC %s%s\n", SYMBOL_PREFIX, name);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  EXPORT %s%s\n", SYMBOL_PREFIX, name);
+  } else {
+    fprintf(fp_, "PUBLIC %s%s\n", SYMBOL_PREFIX, name);
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::AlignToCodeAlignment() {
-  // Diverges from other platforms due to compile error
-  // 'invalid combination with segment alignment'.
-  fprintf(fp_, "ALIGN 4\n");
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  ALIGN %d\n", ARM64_CODE_ALIGNMENT);
+  } else {
+    // Diverges from other platforms due to compile error
+    // 'invalid combination with segment alignment'.
+    fprintf(fp_, "ALIGN 4\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::AlignToDataAlignment() {
-  fprintf(fp_, "ALIGN 4\n");
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  ALIGN %d\n", ARM64_DATA_ALIGNMENT);
+
+  } else {
+    fprintf(fp_, "ALIGN 4\n");
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::Comment(const char* string) {
@@ -408,8 +484,13 @@ void PlatformEmbeddedFileWriterWin::Comment(const char* string) {
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareLabel(const char* name) {
-  fprintf(fp_, "%s%s LABEL %s\n", SYMBOL_PREFIX, name,
-          DirectiveAsString(kByte));
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "%s%s\t", SYMBOL_PREFIX, name);
+
+  } else {
+    fprintf(fp_, "%s%s LABEL %s\n", SYMBOL_PREFIX, name,
+            DirectiveAsString(kByte));
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::SourceInfo(int fileid, const char* filename,
@@ -421,19 +502,36 @@ void PlatformEmbeddedFileWriterWin::SourceInfo(int fileid, const char* filename,
 // TODO(mmarchini): investigate emitting size annotations for Windows
 void PlatformEmbeddedFileWriterWin::DeclareFunctionBegin(const char* name,
                                                          uint32_t size) {
-  fprintf(fp_, "%s%s PROC\n", SYMBOL_PREFIX, name);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "%s%s FUNCTION\n", SYMBOL_PREFIX, name);
+
+  } else {
+    fprintf(fp_, "%s%s PROC\n", SYMBOL_PREFIX, name);
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::DeclareFunctionEnd(const char* name) {
-  fprintf(fp_, "%s%s ENDP\n", SYMBOL_PREFIX, name);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  ENDFUNC\n");
+
+  } else {
+    fprintf(fp_, "%s%s ENDP\n", SYMBOL_PREFIX, name);
+  }
 }
 
 int PlatformEmbeddedFileWriterWin::HexLiteral(uint64_t value) {
-  return fprintf(fp_, "0%" PRIx64 "h", value);
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    return fprintf(fp_, "0x%" PRIx64, value);
+
+  } else {
+    return fprintf(fp_, "0%" PRIx64 "h", value);
+  }
 }
 
 void PlatformEmbeddedFileWriterWin::FilePrologue() {
-  if (target_arch_ != EmbeddedTargetArch::kX64) {
+  if (target_arch_ != EmbeddedTargetArch::kArm64 &&
+      target_arch_ != EmbeddedTargetArch::kX64) {
+    // x86 falls into this case
     fprintf(fp_, ".MODEL FLAT\n");
   }
 }
@@ -441,110 +539,14 @@ void PlatformEmbeddedFileWriterWin::FilePrologue() {
 void PlatformEmbeddedFileWriterWin::DeclareExternalFilename(
     int fileid, const char* filename) {}
 
-void PlatformEmbeddedFileWriterWin::FileEpilogue() { fprintf(fp_, "END\n"); }
-
-int PlatformEmbeddedFileWriterWin::IndentedDataDirective(
-    DataDirective directive) {
-  return fprintf(fp_, "  %s ", DirectiveAsString(directive));
-}
-
-// Windows, MSVC, arm/arm64.
-// -----------------------------------------------------------------------------
-
-#elif defined(V8_ASSEMBLER_IS_MARMASM)
-
-// The AARCH64 ABI requires instructions be 4-byte-aligned and Windows does
-// not have a stricter alignment requirement (see the TEXTAREA macro of
-// kxarm64.h in the Windows SDK), so code is 4-byte-aligned.
-// The data fields in the emitted assembly tend to be accessed with 8-byte
-// LDR instructions, so data is 8-byte-aligned.
-//
-// armasm64's warning A4228 states
-//     Alignment value exceeds AREA alignment; alignment not guaranteed
-// To ensure that ALIGN directives are honored, their values are defined as
-// equal to their corresponding AREA's ALIGN attributes.
-
-#define ARM64_DATA_ALIGNMENT_POWER (3)
-#define ARM64_DATA_ALIGNMENT (1 << ARM64_DATA_ALIGNMENT_POWER)
-#define ARM64_CODE_ALIGNMENT_POWER (2)
-#define ARM64_CODE_ALIGNMENT (1 << ARM64_CODE_ALIGNMENT_POWER)
-
-void PlatformEmbeddedFileWriterWin::SectionText() {
-  fprintf(fp_, "  AREA |.text|, CODE, ALIGN=%d, READONLY\n",
-          ARM64_CODE_ALIGNMENT_POWER);
-}
-
-void PlatformEmbeddedFileWriterWin::SectionData() {
-  fprintf(fp_, "  AREA |.data|, DATA, ALIGN=%d, READWRITE\n",
-          ARM64_DATA_ALIGNMENT_POWER);
-}
-
-void PlatformEmbeddedFileWriterWin::SectionRoData() {
-  fprintf(fp_, "  AREA |.rodata|, DATA, ALIGN=%d, READONLY\n",
-          ARM64_DATA_ALIGNMENT_POWER);
-}
-
-void PlatformEmbeddedFileWriterWin::DeclareUint32(const char* name,
-                                                  uint32_t value) {
-  DeclareSymbolGlobal(name);
-  fprintf(fp_, "%s%s %s %d\n", SYMBOL_PREFIX, name, DirectiveAsString(kLong),
-          value);
-}
-
-void PlatformEmbeddedFileWriterWin::DeclarePointerToSymbol(const char* name,
-                                                           const char* target) {
-  DeclareSymbolGlobal(name);
-  fprintf(fp_, "%s%s %s %s%s\n", SYMBOL_PREFIX, name,
-          DirectiveAsString(PointerSizeDirective()), SYMBOL_PREFIX, target);
-}
-
-void PlatformEmbeddedFileWriterWin::DeclareSymbolGlobal(const char* name) {
-  fprintf(fp_, "  EXPORT %s%s\n", SYMBOL_PREFIX, name);
-}
-
-void PlatformEmbeddedFileWriterWin::AlignToCodeAlignment() {
-  fprintf(fp_, "  ALIGN %d\n", ARM64_CODE_ALIGNMENT);
-}
-
-void PlatformEmbeddedFileWriterWin::AlignToDataAlignment() {
-  fprintf(fp_, "  ALIGN %d\n", ARM64_DATA_ALIGNMENT);
-}
-
-void PlatformEmbeddedFileWriterWin::Comment(const char* string) {
-  fprintf(fp_, "; %s\n", string);
-}
-
-void PlatformEmbeddedFileWriterWin::DeclareLabel(const char* name) {
-  fprintf(fp_, "%s%s\n", SYMBOL_PREFIX, name);
-}
-
-void PlatformEmbeddedFileWriterWin::SourceInfo(int fileid, const char* filename,
-                                               int line) {
-  // TODO(mvstanton): output source information for MSVC.
-  // Its syntax is #line <line> "<filename>"
-}
-
-// TODO(mmarchini): investigate emitting size annotations for Windows
-void PlatformEmbeddedFileWriterWin::DeclareFunctionBegin(const char* name,
-                                                         uint32_t size) {
-  fprintf(fp_, "%s%s FUNCTION\n", SYMBOL_PREFIX, name);
-}
-
-void PlatformEmbeddedFileWriterWin::DeclareFunctionEnd(const char* name) {
-  fprintf(fp_, "  ENDFUNC\n");
-}
-
-int PlatformEmbeddedFileWriterWin::HexLiteral(uint64_t value) {
-  return fprintf(fp_, "0x%" PRIx64, value);
+void PlatformEmbeddedFileWriterWin::FileEpilogue() {
+  if (target_arch_ == EmbeddedTargetArch::kArm64) {
+    fprintf(fp_, "  END\n");
+  } else {
+    fprintf(fp_, "END\n");
+  }
 }
 
-void PlatformEmbeddedFileWriterWin::FilePrologue() {}
-
-void PlatformEmbeddedFileWriterWin::DeclareExternalFilename(
-    int fileid, const char* filename) {}
-
-void PlatformEmbeddedFileWriterWin::FileEpilogue() { fprintf(fp_, "  END\n"); }
-
 int PlatformEmbeddedFileWriterWin::IndentedDataDirective(
     DataDirective directive) {
   return fprintf(fp_, "  %s ", DirectiveAsString(directive));
diff --git a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.h b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.h
index 907cb84ac4..0fcb48dc30 100644
--- a/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.h
+++ b/deps/v8/src/snapshot/embedded/platform-embedded-file-writer-win.h
@@ -66,6 +66,7 @@ class PlatformEmbeddedFileWriterWin : public PlatformEmbeddedFileWriterBase {
 
  private:
   void DeclareSymbolGlobal(const char* name);
+  const char* DirectiveAsString(DataDirective directive);
 
  private:
   const EmbeddedTargetArch target_arch_;
diff --git a/deps/v8/src/snapshot/object-deserializer.cc b/deps/v8/src/snapshot/object-deserializer.cc
index ab6ddf1d0c..cca8d42240 100644
--- a/deps/v8/src/snapshot/object-deserializer.cc
+++ b/deps/v8/src/snapshot/object-deserializer.cc
@@ -33,7 +33,6 @@ ObjectDeserializer::DeserializeSharedFunctionInfo(
 
 MaybeHandle<HeapObject> ObjectDeserializer::Deserialize(Isolate* isolate) {
   Initialize(isolate);
-
   if (!allocator()->ReserveSpace()) return MaybeHandle<HeapObject>();
 
   DCHECK(deserializing_user_code());
@@ -82,7 +81,7 @@ void ObjectDeserializer::CommitPostProcessedObjects() {
   Factory* factory = isolate()->factory();
   for (Handle<Script> script : new_scripts()) {
     // Assign a new script id to avoid collision.
-    script->set_id(isolate()->heap()->NextScriptId());
+    script->set_id(isolate()->GetNextScriptId());
     LogScriptEvents(*script);
     // Add script to list.
     Handle<WeakArrayList> list = factory->script_list();
diff --git a/deps/v8/src/snapshot/partial-serializer.cc b/deps/v8/src/snapshot/partial-serializer.cc
index c362fdb0ce..56b29a2ac7 100644
--- a/deps/v8/src/snapshot/partial-serializer.cc
+++ b/deps/v8/src/snapshot/partial-serializer.cc
@@ -103,8 +103,7 @@ void PartialSerializer::SerializeObject(HeapObject obj) {
 
   // Clear InterruptBudget when serializing FeedbackCell.
   if (obj.IsFeedbackCell()) {
-    FeedbackCell::cast(obj).set_interrupt_budget(
-        FeedbackCell::GetInitialInterruptBudget());
+    FeedbackCell::cast(obj).SetInitialInterruptBudget();
   }
 
   if (SerializeJSObjectWithEmbedderFields(obj)) {
diff --git a/deps/v8/src/snapshot/read-only-serializer.cc b/deps/v8/src/snapshot/read-only-serializer.cc
index 4ddaf37773..41e6188154 100644
--- a/deps/v8/src/snapshot/read-only-serializer.cc
+++ b/deps/v8/src/snapshot/read-only-serializer.cc
@@ -19,6 +19,7 @@ namespace internal {
 ReadOnlySerializer::ReadOnlySerializer(Isolate* isolate)
     : RootsSerializer(isolate, RootIndex::kFirstReadOnlyRoot) {
   STATIC_ASSERT(RootIndex::kFirstReadOnlyRoot == RootIndex::kFirstRoot);
+  allocator()->UseCustomChunkSize(FLAG_serialization_chunk_size);
 }
 
 ReadOnlySerializer::~ReadOnlySerializer() {
diff --git a/deps/v8/src/snapshot/serializer-common.cc b/deps/v8/src/snapshot/serializer-common.cc
index 1703af7717..9218d4eaa9 100644
--- a/deps/v8/src/snapshot/serializer-common.cc
+++ b/deps/v8/src/snapshot/serializer-common.cc
@@ -100,7 +100,6 @@ void SerializedData::AllocateData(uint32_t size) {
   data_ = NewArray<byte>(size);
   size_ = size;
   owns_data_ = true;
-  DCHECK(IsAligned(reinterpret_cast<intptr_t>(data_), kPointerAlignment));
 }
 
 // static
@@ -146,7 +145,7 @@ void SerializerDeserializer::RestoreExternalReferenceRedirectors(
   }
 }
 
-V8_EXPORT_PRIVATE extern uint32_t Checksum(Vector<const byte> payload) {
+uint32_t Checksum(Vector<const byte> payload) {
 #ifdef MEMORY_SANITIZER
   // Computing the checksum includes padding bytes for objects like strings.
   // Mark every object as initialized in the code serializer.
diff --git a/deps/v8/src/snapshot/serializer.cc b/deps/v8/src/snapshot/serializer.cc
index fe7feb0bf0..9ad8d091cd 100644
--- a/deps/v8/src/snapshot/serializer.cc
+++ b/deps/v8/src/snapshot/serializer.cc
@@ -397,6 +397,7 @@ void Serializer::ObjectSerializer::SerializeJSArrayBuffer() {
   // We cannot store byte_length larger than Smi range in the snapshot.
   CHECK_LE(buffer.byte_length(), Smi::kMaxValue);
   int32_t byte_length = static_cast<int32_t>(buffer.byte_length());
+  ArrayBufferExtension* extension = buffer.extension();
 
   // The embedder-allocated backing store only exists for the off-heap case.
   if (backing_store != nullptr) {
@@ -405,9 +406,16 @@ void Serializer::ObjectSerializer::SerializeJSArrayBuffer() {
     // a backing store address. On deserialization we re-set data pointer
     // to proper value.
     buffer.set_backing_store(reinterpret_cast<void*>(static_cast<size_t>(ref)));
+
+    // Ensure deterministic output by setting extension to null during
+    // serialization.
+    buffer.set_extension(nullptr);
   }
+
   SerializeObject();
+
   buffer.set_backing_store(backing_store);
+  buffer.set_extension(extension);
 }
 
 void Serializer::ObjectSerializer::SerializeExternalString() {
diff --git a/deps/v8/src/snapshot/snapshot-common.cc b/deps/v8/src/snapshot/snapshot-common.cc
index 8e0c28c6d6..8e80b0b0b0 100644
--- a/deps/v8/src/snapshot/snapshot-common.cc
+++ b/deps/v8/src/snapshot/snapshot-common.cc
@@ -14,9 +14,21 @@
 #include "src/utils/memcopy.h"
 #include "src/utils/version.h"
 
+#ifdef V8_SNAPSHOT_COMPRESSION
+#include "src/snapshot/snapshot-compression.h"
+#endif
+
 namespace v8 {
 namespace internal {
 
+SnapshotData MaybeDecompress(const Vector<const byte>& snapshot_data) {
+#ifdef V8_SNAPSHOT_COMPRESSION
+  return SnapshotCompression::Decompress(snapshot_data);
+#else
+  return SnapshotData(snapshot_data);
+#endif
+}
+
 #ifdef DEBUG
 bool Snapshot::SnapshotIsValid(const v8::StartupData* snapshot_blob) {
   return Snapshot::ExtractNumContexts(snapshot_blob) > 0;
@@ -43,9 +55,11 @@ bool Snapshot::Initialize(Isolate* isolate) {
   CheckVersion(blob);
   CHECK(VerifyChecksum(blob));
   Vector<const byte> startup_data = ExtractStartupData(blob);
-  SnapshotData startup_snapshot_data(startup_data);
   Vector<const byte> read_only_data = ExtractReadOnlyData(blob);
-  SnapshotData read_only_snapshot_data(read_only_data);
+
+  SnapshotData startup_snapshot_data(MaybeDecompress(startup_data));
+  SnapshotData read_only_snapshot_data(MaybeDecompress(read_only_data));
+
   StartupDeserializer startup_deserializer(&startup_snapshot_data);
   ReadOnlyDeserializer read_only_deserializer(&read_only_snapshot_data);
   startup_deserializer.SetRehashability(ExtractRehashability(blob));
@@ -73,7 +87,7 @@ MaybeHandle<Context> Snapshot::NewContextFromSnapshot(
   bool can_rehash = ExtractRehashability(blob);
   Vector<const byte> context_data =
       ExtractContextData(blob, static_cast<uint32_t>(context_index));
-  SnapshotData snapshot_data(context_data);
+  SnapshotData snapshot_data(MaybeDecompress(context_data));
 
   MaybeHandle<Context> maybe_result = PartialDeserializer::DeserializeContext(
       isolate, &snapshot_data, can_rehash, global_proxy,
@@ -116,24 +130,49 @@ void ProfileDeserialization(
 }
 
 v8::StartupData Snapshot::CreateSnapshotBlob(
-    const SnapshotData* startup_snapshot,
-    const SnapshotData* read_only_snapshot,
-    const std::vector<SnapshotData*>& context_snapshots, bool can_be_rehashed) {
-  uint32_t num_contexts = static_cast<uint32_t>(context_snapshots.size());
+    const SnapshotData* startup_snapshot_in,
+    const SnapshotData* read_only_snapshot_in,
+    const std::vector<SnapshotData*>& context_snapshots_in,
+    bool can_be_rehashed) {
+  // Have these separate from snapshot_in for compression, since we need to
+  // access the compressed data as well as the uncompressed reservations.
+  const SnapshotData* startup_snapshot;
+  const SnapshotData* read_only_snapshot;
+  const std::vector<SnapshotData*>* context_snapshots;
+#ifdef V8_SNAPSHOT_COMPRESSION
+  SnapshotData startup_compressed(
+      SnapshotCompression::Compress(startup_snapshot_in));
+  SnapshotData read_only_compressed(
+      SnapshotCompression::Compress(read_only_snapshot_in));
+  startup_snapshot = &startup_compressed;
+  read_only_snapshot = &read_only_compressed;
+  std::vector<SnapshotData> context_snapshots_compressed;
+  context_snapshots_compressed.reserve(context_snapshots_in.size());
+  std::vector<SnapshotData*> context_snapshots_compressed_ptrs;
+  for (unsigned int i = 0; i < context_snapshots_in.size(); ++i) {
+    context_snapshots_compressed.push_back(
+        SnapshotCompression::Compress(context_snapshots_in[i]));
+    context_snapshots_compressed_ptrs.push_back(
+        &context_snapshots_compressed[i]);
+  }
+  context_snapshots = &context_snapshots_compressed_ptrs;
+#else
+  startup_snapshot = startup_snapshot_in;
+  read_only_snapshot = read_only_snapshot_in;
+  context_snapshots = &context_snapshots_in;
+#endif
+
+  uint32_t num_contexts = static_cast<uint32_t>(context_snapshots->size());
   uint32_t startup_snapshot_offset = StartupSnapshotOffset(num_contexts);
   uint32_t total_length = startup_snapshot_offset;
-  DCHECK(IsAligned(total_length, kPointerAlignment));
   total_length += static_cast<uint32_t>(startup_snapshot->RawData().length());
-  DCHECK(IsAligned(total_length, kPointerAlignment));
   total_length += static_cast<uint32_t>(read_only_snapshot->RawData().length());
-  DCHECK(IsAligned(total_length, kPointerAlignment));
-  for (const auto context_snapshot : context_snapshots) {
+  for (const auto context_snapshot : *context_snapshots) {
     total_length += static_cast<uint32_t>(context_snapshot->RawData().length());
-    DCHECK(IsAligned(total_length, kPointerAlignment));
   }
 
-  ProfileDeserialization(read_only_snapshot, startup_snapshot,
-                         context_snapshots);
+  ProfileDeserialization(read_only_snapshot_in, startup_snapshot_in,
+                         context_snapshots_in);
 
   char* data = new char[total_length];
   // Zero out pre-payload data. Part of that is only used for padding.
@@ -157,7 +196,7 @@ v8::StartupData Snapshot::CreateSnapshotBlob(
   if (FLAG_profile_deserialization) {
     PrintF("Snapshot blob consists of:\n%10d bytes in %d chunks for startup\n",
            payload_length,
-           static_cast<uint32_t>(startup_snapshot->Reservations().size()));
+           static_cast<uint32_t>(startup_snapshot_in->Reservations().size()));
   }
   payload_offset += payload_length;
 
@@ -176,15 +215,17 @@ v8::StartupData Snapshot::CreateSnapshotBlob(
   // Partial snapshots (context-specific data).
   for (uint32_t i = 0; i < num_contexts; i++) {
     SetHeaderValue(data, ContextSnapshotOffsetOffset(i), payload_offset);
-    SnapshotData* context_snapshot = context_snapshots[i];
+    SnapshotData* context_snapshot = (*context_snapshots)[i];
     payload_length = context_snapshot->RawData().length();
     CopyBytes(
         data + payload_offset,
         reinterpret_cast<const char*>(context_snapshot->RawData().begin()),
         payload_length);
     if (FLAG_profile_deserialization) {
-      PrintF("%10d bytes in %d chunks for context #%d\n", payload_length,
-             static_cast<uint32_t>(context_snapshot->Reservations().size()), i);
+      PrintF(
+          "%10d bytes in %d chunks for context #%d\n", payload_length,
+          static_cast<uint32_t>(context_snapshots_in[i]->Reservations().size()),
+          i);
     }
     payload_offset += payload_length;
   }
@@ -310,7 +351,6 @@ SnapshotData::SnapshotData(const Serializer* serializer) {
   uint32_t padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
   uint32_t size =
       padded_payload_offset + static_cast<uint32_t>(payload->size());
-  DCHECK(IsAligned(size, kPointerAlignment));
 
   // Allocate backing store and create result data.
   AllocateData(size);
@@ -358,13 +398,11 @@ bool RunExtraCode(v8::Isolate* isolate, v8::Local<v8::Context> context,
   v8::Context::Scope context_scope(context);
   v8::TryCatch try_catch(isolate);
   v8::Local<v8::String> source_string;
-  if (!v8::String::NewFromUtf8(isolate, utf8_source, v8::NewStringType::kNormal)
-           .ToLocal(&source_string)) {
+  if (!v8::String::NewFromUtf8(isolate, utf8_source).ToLocal(&source_string)) {
     return false;
   }
   v8::Local<v8::String> resource_name =
-      v8::String::NewFromUtf8(isolate, name, v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8(isolate, name).ToLocalChecked();
   v8::ScriptOrigin origin(resource_name);
   v8::ScriptCompiler::Source source(source_string, origin);
   v8::Local<v8::Script> script;
diff --git a/deps/v8/src/snapshot/snapshot-compression.cc b/deps/v8/src/snapshot/snapshot-compression.cc
new file mode 100644
index 0000000000..dea16bfa34
--- /dev/null
+++ b/deps/v8/src/snapshot/snapshot-compression.cc
@@ -0,0 +1,95 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/snapshot/snapshot-compression.h"
+
+#include "src/utils/memcopy.h"
+#include "third_party/zlib/google/compression_utils_portable.h"
+
+namespace v8 {
+namespace internal {
+
+uint32_t GetUncompressedSize(const Bytef* compressed_data) {
+  uint32_t size;
+  MemCopy(&size, compressed_data, sizeof(size));
+  return size;
+}
+
+SnapshotData SnapshotCompression::Compress(
+    const SnapshotData* uncompressed_data) {
+  SnapshotData snapshot_data;
+  base::ElapsedTimer timer;
+  if (FLAG_profile_deserialization) timer.Start();
+
+  static_assert(sizeof(Bytef) == 1, "");
+  const uLongf input_size =
+      static_cast<uLongf>(uncompressed_data->RawData().size());
+  uint32_t payload_length =
+      static_cast<uint32_t>(uncompressed_data->RawData().size());
+
+  uLongf compressed_data_size = compressBound(input_size);
+
+  // Allocating >= the final amount we will need.
+  snapshot_data.AllocateData(
+      static_cast<uint32_t>(sizeof(payload_length) + compressed_data_size));
+
+  byte* compressed_data = const_cast<byte*>(snapshot_data.RawData().begin());
+  // Since we are doing raw compression (no zlib or gzip headers), we need to
+  // manually store the uncompressed size.
+  MemCopy(compressed_data, &payload_length, sizeof(payload_length));
+
+  CHECK_EQ(zlib_internal::CompressHelper(
+               zlib_internal::ZRAW, compressed_data + sizeof(payload_length),
+               &compressed_data_size,
+               bit_cast<const Bytef*>(uncompressed_data->RawData().begin()),
+               input_size, Z_DEFAULT_COMPRESSION, nullptr, nullptr),
+           Z_OK);
+
+  // Reallocating to exactly the size we need.
+  snapshot_data.Resize(static_cast<uint32_t>(compressed_data_size) +
+                       sizeof(payload_length));
+  DCHECK_EQ(payload_length,
+            GetUncompressedSize(snapshot_data.RawData().begin()));
+
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    PrintF("[Compressing %d bytes took %0.3f ms]\n", payload_length, ms);
+  }
+  return snapshot_data;
+}
+
+SnapshotData SnapshotCompression::Decompress(
+    Vector<const byte> compressed_data) {
+  SnapshotData snapshot_data;
+  base::ElapsedTimer timer;
+  if (FLAG_profile_deserialization) timer.Start();
+
+  const Bytef* input_bytef = bit_cast<const Bytef*>(compressed_data.begin());
+
+  // Since we are doing raw compression (no zlib or gzip headers), we need to
+  // manually retrieve the uncompressed size.
+  uint32_t uncompressed_payload_length = GetUncompressedSize(input_bytef);
+  input_bytef += sizeof(uncompressed_payload_length);
+
+  snapshot_data.AllocateData(uncompressed_payload_length);
+
+  uLongf uncompressed_size = uncompressed_payload_length;
+  CHECK_EQ(zlib_internal::UncompressHelper(
+               zlib_internal::ZRAW,
+               bit_cast<Bytef*>(snapshot_data.RawData().begin()),
+               &uncompressed_size, input_bytef,
+               static_cast<uLong>(compressed_data.size() -
+                                  sizeof(uncompressed_payload_length))),
+           Z_OK);
+
+  if (FLAG_profile_deserialization) {
+    double ms = timer.Elapsed().InMillisecondsF();
+    PrintF("[Decompressing %d bytes took %0.3f ms]\n",
+           uncompressed_payload_length, ms);
+  }
+  return snapshot_data;
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/snapshot/snapshot-compression.h b/deps/v8/src/snapshot/snapshot-compression.h
new file mode 100644
index 0000000000..59c21feb74
--- /dev/null
+++ b/deps/v8/src/snapshot/snapshot-compression.h
@@ -0,0 +1,27 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_SNAPSHOT_SNAPSHOT_COMPRESSION_H_
+#define V8_SNAPSHOT_SNAPSHOT_COMPRESSION_H_
+
+#include "src/snapshot/serializer-common.h"
+#include "src/snapshot/serializer.h"
+#include "src/snapshot/snapshot.h"
+#include "src/utils/vector.h"
+
+namespace v8 {
+namespace internal {
+
+class SnapshotCompression : public AllStatic {
+ public:
+  V8_EXPORT_PRIVATE static SnapshotData Compress(
+      const SnapshotData* uncompressed_data);
+  V8_EXPORT_PRIVATE static SnapshotData Decompress(
+      Vector<const byte> compressed_data);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_SNAPSHOT_SNAPSHOT_COMPRESSION_H_
diff --git a/deps/v8/src/snapshot/snapshot.h b/deps/v8/src/snapshot/snapshot.h
index 156d873019..d9f05c59a8 100644
--- a/deps/v8/src/snapshot/snapshot.h
+++ b/deps/v8/src/snapshot/snapshot.h
@@ -16,6 +16,7 @@ namespace internal {
 // Forward declarations.
 class Isolate;
 class PartialSerializer;
+class SnapshotCompression;
 class StartupSerializer;
 
 // Wrapper around reservation sizes and the serialization payload.
@@ -37,6 +38,15 @@ class V8_EXPORT_PRIVATE SnapshotData : public SerializedData {
   }
 
  protected:
+  // Empty constructor used by SnapshotCompression so it can manually allocate
+  // memory.
+  SnapshotData() : SerializedData() {}
+  friend class SnapshotCompression;
+
+  // Resize used by SnapshotCompression so it can shrink the compressed
+  // SnapshotData.
+  void Resize(uint32_t size) { size_ = size; }
+
   // The data header consists of uint32_t-sized entries:
   // [0] magic number and (internal) external reference count
   // [1] number of reservation size entries
@@ -77,9 +87,9 @@ class Snapshot : public AllStatic {
   // ---------------- Serialization ----------------
 
   static v8::StartupData CreateSnapshotBlob(
-      const SnapshotData* startup_snapshot,
-      const SnapshotData* read_only_snapshot,
-      const std::vector<SnapshotData*>& context_snapshots,
+      const SnapshotData* startup_snapshot_in,
+      const SnapshotData* read_only_snapshot_in,
+      const std::vector<SnapshotData*>& context_snapshots_in,
       bool can_be_rehashed);
 
 #ifdef DEBUG
diff --git a/deps/v8/src/snapshot/startup-deserializer.cc b/deps/v8/src/snapshot/startup-deserializer.cc
index 8d99238d1e..7ef6ac6168 100644
--- a/deps/v8/src/snapshot/startup-deserializer.cc
+++ b/deps/v8/src/snapshot/startup-deserializer.cc
@@ -54,6 +54,10 @@ void StartupDeserializer::DeserializeInto(Isolate* isolate) {
     isolate->heap()->set_allocation_sites_list(
         ReadOnlyRoots(isolate).undefined_value());
   }
+  isolate->heap()->set_dirty_js_finalization_registries_list(
+      ReadOnlyRoots(isolate).undefined_value());
+  isolate->heap()->set_dirty_js_finalization_registries_list_tail(
+      ReadOnlyRoots(isolate).undefined_value());
 
   isolate->builtins()->MarkInitialized();
 
diff --git a/deps/v8/src/snapshot/startup-serializer.cc b/deps/v8/src/snapshot/startup-serializer.cc
index 4d6ce78b59..8b95ca6b6a 100644
--- a/deps/v8/src/snapshot/startup-serializer.cc
+++ b/deps/v8/src/snapshot/startup-serializer.cc
@@ -23,6 +23,7 @@ StartupSerializer::StartupSerializer(Isolate* isolate,
                                      ReadOnlySerializer* read_only_serializer)
     : RootsSerializer(isolate, RootIndex::kFirstStrongRoot),
       read_only_serializer_(read_only_serializer) {
+  allocator()->UseCustomChunkSize(FLAG_serialization_chunk_size);
   InitializeCodeAddressMap();
 }
 
@@ -169,6 +170,15 @@ void StartupSerializer::SerializeUsingPartialSnapshotCache(
   sink->PutInt(cache_index, "partial_snapshot_cache_index");
 }
 
+void StartupSerializer::CheckNoDirtyFinalizationRegistries() {
+  Isolate* isolate = this->isolate();
+  CHECK(isolate->heap()->dirty_js_finalization_registries_list().IsUndefined(
+      isolate));
+  CHECK(
+      isolate->heap()->dirty_js_finalization_registries_list_tail().IsUndefined(
+          isolate));
+}
+
 void SerializedHandleChecker::AddToSet(FixedArray serialized) {
   int length = serialized.length();
   for (int i = 0; i < length; i++) serialized_.insert(serialized.get(i));
diff --git a/deps/v8/src/snapshot/startup-serializer.h b/deps/v8/src/snapshot/startup-serializer.h
index 5ab98ed8ba..50c023852f 100644
--- a/deps/v8/src/snapshot/startup-serializer.h
+++ b/deps/v8/src/snapshot/startup-serializer.h
@@ -41,6 +41,10 @@ class V8_EXPORT_PRIVATE StartupSerializer : public RootsSerializer {
   void SerializeUsingPartialSnapshotCache(SnapshotByteSink* sink,
                                           HeapObject obj);
 
+  // The per-heap dirty FinalizationRegistry list is weak and not serialized. No
+  // JSFinalizationRegistries should be used during startup.
+  void CheckNoDirtyFinalizationRegistries();
+
  private:
   void SerializeObject(HeapObject o) override;
 
diff --git a/deps/v8/src/strings/string-hasher-inl.h b/deps/v8/src/strings/string-hasher-inl.h
index 2857b27731..cac574637b 100644
--- a/deps/v8/src/strings/string-hasher-inl.h
+++ b/deps/v8/src/strings/string-hasher-inl.h
@@ -35,18 +35,13 @@ uint32_t StringHasher::GetHashCore(uint32_t running_hash) {
 
 uint32_t StringHasher::GetTrivialHash(int length) {
   DCHECK_GT(length, String::kMaxHashCalcLength);
-  // The hash of a large string is simply computed from the length. We don't
-  // have quite enough bits, so we drop the least significant bit.
-  // TODO(9904): Free up one bit, so we don't have to drop anything here.
-  constexpr int kDroppedBits = 1;
-  // Ensure that the max length after dropping bits is small enough to be
-  // shifted without losing information.
-  STATIC_ASSERT(base::bits::CountLeadingZeros32(String::kMaxLength) +
-                    kDroppedBits >=
+  // The hash of a large string is simply computed from the length.
+  // Ensure that the max length is small enough to be shifted without losing
+  // information.
+  STATIC_ASSERT(base::bits::CountLeadingZeros32(String::kMaxLength) >=
                 String::kHashShift);
-  uint32_t hash = static_cast<uint32_t>(length) >> kDroppedBits;
-  return (hash << String::kHashShift) | String::kIsNotArrayIndexMask |
-         String::kIsNotIntegerIndexMask;
+  uint32_t hash = static_cast<uint32_t>(length);
+  return (hash << String::kHashShift) | String::kIsNotIntegerIndexMask;
 }
 
 template <typename char_t>
@@ -93,8 +88,17 @@ uint32_t StringHasher::HashSequentialString(const char_t* chars_raw, int length,
           }
           running_hash = AddCharacterCore(running_hash, *chars++);
         }
-        return (GetHashCore(running_hash) << String::kHashShift) |
-               String::kIsNotArrayIndexMask | is_integer_index;
+        uint32_t hash = (GetHashCore(running_hash) << String::kHashShift) |
+                        is_integer_index;
+        if (Name::ContainsCachedArrayIndex(hash)) {
+          // The hash accidentally looks like a cached index. Fix that by
+          // setting a bit that looks like a longer-than-cacheable string
+          // length.
+          hash |= (String::kMaxCachedArrayIndexLength + 1)
+                  << String::ArrayIndexLengthBits::kShift;
+        }
+        DCHECK(!Name::ContainsCachedArrayIndex(hash));
+        return hash;
       }
 #endif
     }
@@ -113,7 +117,7 @@ uint32_t StringHasher::HashSequentialString(const char_t* chars_raw, int length,
   }
 
   return (GetHashCore(running_hash) << String::kHashShift) |
-         String::kIsNotArrayIndexMask | String::kIsNotIntegerIndexMask;
+         String::kIsNotIntegerIndexMask;
 }
 
 std::size_t SeededStringHasher::operator()(const char* name) const {
diff --git a/deps/v8/src/torque/ast.h b/deps/v8/src/torque/ast.h
index 0b7cf7af9b..93e0622aee 100644
--- a/deps/v8/src/torque/ast.h
+++ b/deps/v8/src/torque/ast.h
@@ -629,6 +629,8 @@ struct BasicTypeExpression : TypeExpression {
         is_constexpr(IsConstexprName(name)),
         name(std::move(name)),
         generic_arguments(std::move(generic_arguments)) {}
+  BasicTypeExpression(SourcePosition pos, std::string name)
+      : BasicTypeExpression(pos, {}, std::move(name), {}) {}
   std::vector<std::string> namespace_qualification;
   bool is_constexpr;
   std::string name;
@@ -838,7 +840,7 @@ struct InstanceTypeConstraints {
 struct AbstractTypeDeclaration : TypeDeclaration {
   DEFINE_AST_NODE_LEAF_BOILERPLATE(AbstractTypeDeclaration)
   AbstractTypeDeclaration(SourcePosition pos, Identifier* name, bool transient,
-                          base::Optional<Identifier*> extends,
+                          base::Optional<TypeExpression*> extends,
                           base::Optional<std::string> generates)
       : TypeDeclaration(kKind, pos, name),
         is_constexpr(IsConstexprName(name->value)),
@@ -847,7 +849,7 @@ struct AbstractTypeDeclaration : TypeDeclaration {
         generates(std::move(generates)) {}
   bool is_constexpr;
   bool transient;
-  base::Optional<Identifier*> extends;
+  base::Optional<TypeExpression*> extends;
   base::Optional<std::string> generates;
 };
 
diff --git a/deps/v8/src/torque/cfg.cc b/deps/v8/src/torque/cfg.cc
index 9726cbfcb3..7ac1662cd4 100644
--- a/deps/v8/src/torque/cfg.cc
+++ b/deps/v8/src/torque/cfg.cc
@@ -209,6 +209,34 @@ void CfgAssembler::OptimizeCfg() {
       [&](Block* b) { return predecessor_count[b->id()] == 0; });
 }
 
+void CfgAssembler::ComputeInputDefinitions() {
+  Worklist<Block*> worklist;
+
+  // Setup start block.
+  Stack<DefinitionLocation> parameter_defs;
+  for (std::size_t i = 0; i < cfg_.ParameterCount(); ++i) {
+    parameter_defs.Push(DefinitionLocation::Parameter(i));
+  }
+  cfg_.start()->MergeInputDefinitions(parameter_defs, &worklist);
+
+  // Run fixpoint algorithm.
+  while (!worklist.IsEmpty()) {
+    Block* block = worklist.Dequeue();
+    Stack<DefinitionLocation> definitions = block->InputDefinitions();
+
+    // Propagate through block's instructions.
+    for (const auto& instruction : block->instructions()) {
+      instruction.RecomputeDefinitionLocations(&definitions, &worklist);
+    }
+  }
+
+  for (Block* block : cfg_.blocks()) {
+    DCHECK_IMPLIES(!block->IsDead(), block->InputDefinitions().Size() ==
+                                         block->InputTypes().Size());
+    USE(block);
+  }
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/torque/cfg.h b/deps/v8/src/torque/cfg.h
index e75172c1e0..e45cb75073 100644
--- a/deps/v8/src/torque/cfg.h
+++ b/deps/v8/src/torque/cfg.h
@@ -53,10 +53,42 @@ class Block {
   size_t id() const { return id_; }
   bool IsDeferred() const { return is_deferred_; }
 
+  void MergeInputDefinitions(const Stack<DefinitionLocation>& input_definitions,
+                             Worklist<Block*>* worklist) {
+    if (!input_definitions_) {
+      input_definitions_ = input_definitions;
+      if (worklist) worklist->Enqueue(this);
+      return;
+    }
+
+    DCHECK_EQ(input_definitions_->Size(), input_definitions.Size());
+    bool changed = false;
+    for (BottomOffset i = 0; i < input_definitions.AboveTop(); ++i) {
+      auto& current = input_definitions_->Peek(i);
+      auto& input = input_definitions.Peek(i);
+      if (current == input) continue;
+      if (current == DefinitionLocation::Phi(this, i.offset)) continue;
+      input_definitions_->Poke(i, DefinitionLocation::Phi(this, i.offset));
+      changed = true;
+    }
+
+    if (changed && worklist) worklist->Enqueue(this);
+  }
+  bool HasInputDefinitions() const {
+    return input_definitions_ != base::nullopt;
+  }
+  const Stack<DefinitionLocation>& InputDefinitions() const {
+    DCHECK(HasInputDefinitions());
+    return *input_definitions_;
+  }
+
+  bool IsDead() const { return !HasInputDefinitions(); }
+
  private:
   ControlFlowGraph* cfg_;
   std::vector<Instruction> instructions_;
   base::Optional<Stack<const Type*>> input_types_;
+  base::Optional<Stack<DefinitionLocation>> input_definitions_;
   const size_t id_;
   bool is_deferred_;
 };
@@ -95,6 +127,9 @@ class ControlFlowGraph {
   }
   const std::vector<Block*>& blocks() const { return placed_blocks_; }
   size_t NumberOfBlockIds() const { return next_block_id_; }
+  std::size_t ParameterCount() const {
+    return start_ ? start_->InputTypes().Size() : 0;
+  }
 
  private:
   std::list<Block> blocks_;
@@ -116,6 +151,7 @@ class CfgAssembler {
     }
     OptimizeCfg();
     DCHECK(CfgIsComplete());
+    ComputeInputDefinitions();
     return cfg_;
   }
 
@@ -167,6 +203,7 @@ class CfgAssembler {
 
   void PrintCurrentStack(std::ostream& s) { s << "stack: " << current_stack_; }
   void OptimizeCfg();
+  void ComputeInputDefinitions();
 
  private:
   friend class CfgAssemblerScopedTemporaryBlock;
diff --git a/deps/v8/src/torque/class-debug-reader-generator.cc b/deps/v8/src/torque/class-debug-reader-generator.cc
index e4f9ddcd60..52646dff26 100644
--- a/deps/v8/src/torque/class-debug-reader-generator.cc
+++ b/deps/v8/src/torque/class-debug-reader-generator.cc
@@ -44,14 +44,22 @@ class ValueTypeFieldIterator {
     int shift_bits;
   };
   const Result operator*() const {
-    if (const StructType* struct_type = StructType::DynamicCast(type_)) {
-      const auto& field = struct_type->fields()[index_];
+    if (auto struct_type = type_->StructSupertype()) {
+      const auto& field = (*struct_type)->fields()[index_];
       return {field.name_and_type, field.pos, *field.offset, 0, 0};
     }
+    const Type* type = type_;
+    int bitfield_start_offset = 0;
+    if (const auto type_wrapped_in_smi =
+            Type::MatchUnaryGeneric(type_, TypeOracle::GetSmiTaggedGeneric())) {
+      type = *type_wrapped_in_smi;
+      bitfield_start_offset = kSmiTagSize + kSmiShiftSize;
+    }
     if (const BitFieldStructType* bit_field_struct_type =
-            BitFieldStructType::DynamicCast(type_)) {
+            BitFieldStructType::DynamicCast(type)) {
       const auto& field = bit_field_struct_type->fields()[index_];
-      return {field.name_and_type, field.pos, 0, field.num_bits, field.offset};
+      return {field.name_and_type, field.pos, 0, field.num_bits,
+              field.offset + bitfield_start_offset};
     }
     UNREACHABLE();
   }
@@ -79,12 +87,17 @@ class ValueTypeFieldsRange {
   ValueTypeFieldIterator begin() { return {type_, 0}; }
   ValueTypeFieldIterator end() {
     size_t index = 0;
-    const StructType* struct_type = StructType::DynamicCast(type_);
-    if (struct_type && struct_type != TypeOracle::GetFloat64OrHoleType()) {
-      index = struct_type->fields().size();
+    base::Optional<const StructType*> struct_type = type_->StructSupertype();
+    if (struct_type && *struct_type != TypeOracle::GetFloat64OrHoleType()) {
+      index = (*struct_type)->fields().size();
+    }
+    const Type* type = type_;
+    if (const auto type_wrapped_in_smi =
+            Type::MatchUnaryGeneric(type_, TypeOracle::GetSmiTaggedGeneric())) {
+      type = *type_wrapped_in_smi;
     }
     if (const BitFieldStructType* bit_field_struct_type =
-            BitFieldStructType::DynamicCast(type_)) {
+            BitFieldStructType::DynamicCast(type)) {
       index = bit_field_struct_type->fields().size();
     }
     return {type_, index};
@@ -115,23 +128,21 @@ class DebugFieldType {
     if (IsTagged()) {
       return storage == kAsStoredInHeap ? "i::Tagged_t" : "uintptr_t";
     }
-    // Note that we need constexpr names to resolve correctly in the global
-    // namespace, because we're passing them as strings to a debugging
-    // extension. We can verify this during build of the debug helper, because
-    // we use this type for a local variable below, and generate this code in
-    // a disjoint namespace. However, we can't emit a useful error at this
-    // point. Instead we'll emit a comment that might be helpful.
+
+    // We can't emit a useful error at this point if the constexpr type name is
+    // wrong, but we can include a comment that might be helpful.
     return GetOriginalType(storage) +
-           " /*Failing? Ensure constexpr type name is fully qualified and "
-           "necessary #includes are in debug-helper-internal.h*/";
+           " /*Failing? Ensure constexpr type name is correct, and the "
+           "necessary #include is in any .tq file*/";
   }
 
   // Returns the type that should be used to represent a field's type to
   // debugging tools that have full V8 symbols. The types returned from this
-  // method are fully qualified and may refer to object types that are not
-  // included in the compilation of the debug helper library.
+  // method are resolveable in the v8::internal namespace and may refer to
+  // object types that are not included in the compilation of the debug helper
+  // library.
   std::string GetOriginalType(TypeStorage storage) const {
-    if (name_and_type_.type->IsStructType()) {
+    if (name_and_type_.type->StructSupertype()) {
       // There's no meaningful type we could use here, because the V8 symbols
       // don't have any definition of a C++ struct matching this struct type.
       return "";
@@ -151,6 +162,26 @@ class DebugFieldType {
     return name_and_type_.type->GetConstexprGeneratedTypeName();
   }
 
+  // Returns a C++ expression that evaluates to a string (type `const char*`)
+  // containing the name of the field's type. The types returned from this
+  // method are resolveable in the v8::internal namespace and may refer to
+  // object types that are not included in the compilation of the debug helper
+  // library.
+  std::string GetTypeString(TypeStorage storage) const {
+    if (IsTagged() || name_and_type_.type->IsStructType()) {
+      // Wrap up the original type in a string literal.
+      return "\"" + GetOriginalType(storage) + "\"";
+    }
+
+    // We require constexpr type names to be resolvable in the v8::internal
+    // namespace, according to the contract in debug-helper.h. In order to
+    // verify at compile time that constexpr type names are resolvable, we use
+    // the type name as a dummy template parameter to a function that just
+    // returns its parameter.
+    return "CheckTypeName<" + GetValueType(storage) + ">(\"" +
+           GetOriginalType(storage) + "\")";
+  }
+
   // Returns the field's size in bytes.
   size_t GetSize() const {
     auto opt_size = SizeOf(name_and_type_.type);
@@ -228,7 +259,7 @@ void GenerateFieldValueAccessor(const Field& field,
                                 std::ostream& h_contents,
                                 std::ostream& cc_contents) {
   // Currently not implemented for struct fields.
-  if (field.name_and_type.type->IsStructType()) return;
+  if (field.name_and_type.type->StructSupertype()) return;
 
   DebugFieldType debug_field_type(field);
 
@@ -243,25 +274,23 @@ void GenerateFieldValueAccessor(const Field& field,
     index_offset = " + offset * sizeof(value)";
   }
 
-  if (!field.name_and_type.type->IsStructType()) {
-    std::string field_value_type = debug_field_type.GetValueType(kUncompressed);
-    h_contents << "  Value<" << field_value_type << "> " << field_getter
-               << "(d::MemoryAccessor accessor " << index_param << ") const;\n";
-    cc_contents << "\nValue<" << field_value_type << "> Tq" << class_name
-                << "::" << field_getter << "(d::MemoryAccessor accessor"
-                << index_param << ") const {\n";
-    cc_contents << "  " << debug_field_type.GetValueType(kAsStoredInHeap)
-                << " value{};\n";
-    cc_contents << "  d::MemoryAccessResult validity = accessor("
-                << address_getter << "()" << index_offset
-                << ", reinterpret_cast<uint8_t*>(&value), sizeof(value));\n";
-    cc_contents << "  return {validity, "
-                << (debug_field_type.IsTagged()
-                        ? "EnsureDecompressed(value, address_)"
-                        : "value")
-                << "};\n";
-    cc_contents << "}\n";
-  }
+  std::string field_value_type = debug_field_type.GetValueType(kUncompressed);
+  h_contents << "  Value<" << field_value_type << "> " << field_getter
+             << "(d::MemoryAccessor accessor " << index_param << ") const;\n";
+  cc_contents << "\nValue<" << field_value_type << "> Tq" << class_name
+              << "::" << field_getter << "(d::MemoryAccessor accessor"
+              << index_param << ") const {\n";
+  cc_contents << "  " << debug_field_type.GetValueType(kAsStoredInHeap)
+              << " value{};\n";
+  cc_contents << "  d::MemoryAccessResult validity = accessor("
+              << address_getter << "()" << index_offset
+              << ", reinterpret_cast<uint8_t*>(&value), sizeof(value));\n";
+  cc_contents << "  return {validity, "
+              << (debug_field_type.IsTagged()
+                      ? "EnsureDecompressed(value, address_)"
+                      : "value")
+              << "};\n";
+  cc_contents << "}\n";
 }
 
 // Emits a portion of the member function GetProperties that is responsible for
@@ -333,10 +362,9 @@ void GenerateGetPropsChunkForField(const Field& field,
                                      struct_field.pos);
     get_props_impl << "  " << struct_field_list
                    << ".push_back(std::make_unique<StructProperty>(\""
-                   << struct_field.name_and_type.name << "\", \""
-                   << struct_field_type.GetOriginalType(kAsStoredInHeap)
-                   << "\", \""
-                   << struct_field_type.GetOriginalType(kUncompressed) << "\", "
+                   << struct_field.name_and_type.name << "\", "
+                   << struct_field_type.GetTypeString(kAsStoredInHeap) << ", "
+                   << struct_field_type.GetTypeString(kUncompressed) << ", "
                    << struct_field.offset_bytes << ", " << struct_field.num_bits
                    << ", " << struct_field.shift_bits << "));\n";
   }
@@ -370,11 +398,11 @@ void GenerateGetPropsChunkForField(const Field& field,
   }
 
   get_props_impl << "  result.push_back(std::make_unique<ObjectProperty>(\""
-                 << field.name_and_type.name << "\", \""
-                 << debug_field_type.GetOriginalType(kAsStoredInHeap)
-                 << "\", \"" << debug_field_type.GetOriginalType(kUncompressed)
-                 << "\", " << debug_field_type.GetAddressGetter() << "(), "
-                 << count_value << ", " << debug_field_type.GetSize() << ", "
+                 << field.name_and_type.name << "\", "
+                 << debug_field_type.GetTypeString(kAsStoredInHeap) << ", "
+                 << debug_field_type.GetTypeString(kUncompressed) << ", "
+                 << debug_field_type.GetAddressGetter() << "(), " << count_value
+                 << ", " << debug_field_type.GetSize() << ", "
                  << struct_field_list << ", " << property_kind << "));\n";
 }
 
@@ -524,12 +552,17 @@ void ImplementationVisitor::GenerateClassDebugReaders(
     h_contents << "#undef GetBValue\n";
     h_contents << "#endif\n\n";
 
+    for (const std::string& include_path : GlobalContext::CppIncludes()) {
+      cc_contents << "#include " << StringLiteralQuote(include_path) << "\n";
+    }
     cc_contents << "#include \"torque-generated/" << file_name << ".h\"\n";
     cc_contents << "#include \"include/v8-internal.h\"\n\n";
     cc_contents << "namespace i = v8::internal;\n\n";
 
-    NamespaceScope h_namespaces(h_contents, {"v8_debug_helper_internal"});
-    NamespaceScope cc_namespaces(cc_contents, {"v8_debug_helper_internal"});
+    NamespaceScope h_namespaces(h_contents,
+                                {"v8", "internal", "debug_helper_internal"});
+    NamespaceScope cc_namespaces(cc_contents,
+                                 {"v8", "internal", "debug_helper_internal"});
 
     std::stringstream visitor;
     visitor << "\nclass TqObjectVisitor {\n";
@@ -539,8 +572,7 @@ void ImplementationVisitor::GenerateClassDebugReaders(
     std::stringstream class_names;
 
     std::unordered_set<const ClassType*> done;
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       GenerateClassDebugReader(*type, h_contents, cc_contents, visitor,
                                class_names, &done);
     }
diff --git a/deps/v8/src/torque/constants.h b/deps/v8/src/torque/constants.h
index 3559daaccd..9eba568ac9 100644
--- a/deps/v8/src/torque/constants.h
+++ b/deps/v8/src/torque/constants.h
@@ -63,13 +63,16 @@ static const char* const CONST_INT31_TYPE_STRING = "constexpr int31";
 static const char* const CONST_INT32_TYPE_STRING = "constexpr int32";
 static const char* const CONST_FLOAT64_TYPE_STRING = "constexpr float64";
 static const char* const TORQUE_INTERNAL_NAMESPACE_STRING = "torque_internal";
-static const char* const REFERENCE_TYPE_STRING = "Reference";
+static const char* const MUTABLE_REFERENCE_TYPE_STRING = "MutableReference";
+static const char* const CONST_REFERENCE_TYPE_STRING = "ConstReference";
 static const char* const SLICE_TYPE_STRING = "Slice";
 static const char* const WEAK_TYPE_STRING = "Weak";
+static const char* const SMI_TAGGED_TYPE_STRING = "SmiTagged";
 static const char* const UNINITIALIZED_ITERATOR_TYPE_STRING =
     "UninitializedIterator";
 static const char* const GENERIC_TYPE_INSTANTIATION_NAMESPACE_STRING =
     "_generic_type_instantiation_namespace";
+static const char* const FIXED_ARRAY_BASE_TYPE_STRING = "FixedArrayBase";
 
 static const char* const ANNOTATION_GENERATE_PRINT = "@generatePrint";
 static const char* const ANNOTATION_NO_VERIFIER = "@noVerifier";
@@ -87,6 +90,9 @@ static const char* const ANNOTATION_INSTANCE_TYPE_VALUE =
     "@apiExposedInstanceTypeValue";
 static const char* const ANNOTATION_IF = "@if";
 static const char* const ANNOTATION_IFNOT = "@ifnot";
+static const char* const ANNOTATION_GENERATE_BODY_DESCRIPTOR =
+    "@generateBodyDescriptor";
+static const char* const ANNOTATION_EXPORT_CPP_CLASS = "@export";
 
 inline bool IsConstexprName(const std::string& name) {
   return name.substr(0, std::strlen(CONSTEXPR_TYPE_PREFIX)) ==
@@ -124,6 +130,8 @@ enum class ClassFlag {
   kHighestInstanceTypeWithinParent = 1 << 9,
   kLowestInstanceTypeWithinParent = 1 << 10,
   kUndefinedLayout = 1 << 11,
+  kGenerateBodyDescriptor = 1 << 12,
+  kExport = 1 << 13,
 };
 using ClassFlags = base::Flags<ClassFlag>;
 
diff --git a/deps/v8/src/torque/csa-generator.cc b/deps/v8/src/torque/csa-generator.cc
index 29e8e1dea2..9716ccbad4 100644
--- a/deps/v8/src/torque/csa-generator.cc
+++ b/deps/v8/src/torque/csa-generator.cc
@@ -6,6 +6,7 @@
 
 #include "src/common/globals.h"
 #include "src/torque/type-oracle.h"
+#include "src/torque/types.h"
 #include "src/torque/utils.h"
 
 namespace v8 {
@@ -14,24 +15,51 @@ namespace torque {
 
 base::Optional<Stack<std::string>> CSAGenerator::EmitGraph(
     Stack<std::string> parameters) {
+  for (BottomOffset i = 0; i < parameters.AboveTop(); ++i) {
+    SetDefinitionVariable(DefinitionLocation::Parameter(i.offset),
+                          parameters.Peek(i));
+  }
+
   for (Block* block : cfg_.blocks()) {
-    out_ << "  compiler::CodeAssemblerParameterizedLabel<";
-    PrintCommaSeparatedList(out_, block->InputTypes(), [](const Type* t) {
-      return t->GetGeneratedTNodeTypeName();
-    });
-    out_ << "> " << BlockName(block) << "(&ca_, compiler::CodeAssemblerLabel::"
-         << (block->IsDeferred() ? "kDeferred" : "kNonDeferred") << ");\n";
+    if (block->IsDead()) continue;
+
+    out() << "  compiler::CodeAssemblerParameterizedLabel<";
+    bool first = true;
+    DCHECK_EQ(block->InputTypes().Size(), block->InputDefinitions().Size());
+    for (BottomOffset i = 0; i < block->InputTypes().AboveTop(); ++i) {
+      if (block->InputDefinitions().Peek(i).IsPhiFromBlock(block)) {
+        if (!first) out() << ", ";
+        out() << block->InputTypes().Peek(i)->GetGeneratedTNodeTypeName();
+        first = false;
+      }
+    }
+    out() << "> " << BlockName(block) << "(&ca_, compiler::CodeAssemblerLabel::"
+          << (block->IsDeferred() ? "kDeferred" : "kNonDeferred") << ");\n";
   }
 
   EmitInstruction(GotoInstruction{cfg_.start()}, &parameters);
   for (Block* block : cfg_.blocks()) {
     if (cfg_.end() && *cfg_.end() == block) continue;
-    out_ << "\n  if (" << BlockName(block) << ".is_used()) {\n";
+    if (block->IsDead()) continue;
+    out() << "\n";
+
+    // Redirect the output of non-declarations into a buffer and only output
+    // declarations right away.
+    std::stringstream out_buffer;
+    std::ostream* old_out = out_;
+    out_ = &out_buffer;
+
+    out() << "  if (" << BlockName(block) << ".is_used()) {\n";
     EmitBlock(block);
-    out_ << "  }\n";
+    out() << "  }\n";
+
+    // All declarations have been printed now, so we can append the buffered
+    // output and redirect back to the original output stream.
+    out_ = old_out;
+    out() << out_buffer.str();
   }
   if (cfg_.end()) {
-    out_ << "\n";
+    out() << "\n";
     return EmitBlock(*cfg_.end());
   }
   return base::nullopt;
@@ -39,16 +67,20 @@ base::Optional<Stack<std::string>> CSAGenerator::EmitGraph(
 
 Stack<std::string> CSAGenerator::EmitBlock(const Block* block) {
   Stack<std::string> stack;
-  for (const Type* t : block->InputTypes()) {
-    stack.Push(FreshNodeName());
-    out_ << "    TNode<" << t->GetGeneratedTNodeTypeName() << "> "
-         << stack.Top() << ";\n";
-  }
-  out_ << "    ca_.Bind(&" << BlockName(block);
-  for (const std::string& name : stack) {
-    out_ << ", &" << name;
+  std::stringstream phi_names;
+
+  for (BottomOffset i = 0; i < block->InputTypes().AboveTop(); ++i) {
+    const auto& def = block->InputDefinitions().Peek(i);
+    stack.Push(DefinitionToVariable(def));
+    if (def.IsPhiFromBlock(block)) {
+      decls() << "  TNode<"
+              << block->InputTypes().Peek(i)->GetGeneratedTNodeTypeName()
+              << "> " << stack.Top() << ";\n";
+      phi_names << ", &" << stack.Top();
+    }
   }
-  out_ << ");\n";
+  out() << "    ca_.Bind(&" << BlockName(block) << phi_names.str() << ");\n";
+
   for (const Instruction& instruction : block->instructions()) {
     EmitInstruction(instruction, &stack);
   }
@@ -60,16 +92,32 @@ void CSAGenerator::EmitSourcePosition(SourcePosition pos, bool always_emit) {
   if (always_emit || !previous_position_.CompareStartIgnoreColumn(pos)) {
     // Lines in Torque SourcePositions are zero-based, while the
     // CodeStubAssembler and downwind systems are one-based.
-    out_ << "    ca_.SetSourcePosition(\"" << file << "\", "
-         << (pos.start.line + 1) << ");\n";
+    out() << "    ca_.SetSourcePosition(\"" << file << "\", "
+          << (pos.start.line + 1) << ");\n";
     previous_position_ = pos;
   }
 }
 
+bool CSAGenerator::IsEmptyInstruction(const Instruction& instruction) {
+  switch (instruction.kind()) {
+    case InstructionKind::kPeekInstruction:
+    case InstructionKind::kPokeInstruction:
+    case InstructionKind::kDeleteRangeInstruction:
+    case InstructionKind::kPushUninitializedInstruction:
+    case InstructionKind::kPushBuiltinPointerInstruction:
+    case InstructionKind::kUnsafeCastInstruction:
+      return true;
+    default:
+      return false;
+  }
+}
+
 void CSAGenerator::EmitInstruction(const Instruction& instruction,
                                    Stack<std::string>* stack) {
 #ifdef DEBUG
-  EmitSourcePosition(instruction->pos);
+  if (!IsEmptyInstruction(instruction)) {
+    EmitSourcePosition(instruction->pos);
+  }
 #endif
 
   switch (instruction.kind()) {
@@ -103,15 +151,20 @@ void CSAGenerator::EmitInstruction(
   // TODO(tebbi): This can trigger an error in CSA if it is used. Instead, we
   // should prevent usage of uninitialized in the type system. This
   // requires "if constexpr" being evaluated at Torque time.
-  stack->Push("ca_.Uninitialized<" +
-              instruction.type->GetGeneratedTNodeTypeName() + ">()");
+  const std::string str = "ca_.Uninitialized<" +
+                          instruction.type->GetGeneratedTNodeTypeName() + ">()";
+  stack->Push(str);
+  SetDefinitionVariable(instruction.GetValueDefinition(), str);
 }
 
 void CSAGenerator::EmitInstruction(
     const PushBuiltinPointerInstruction& instruction,
     Stack<std::string>* stack) {
-  stack->Push("ca_.UncheckedCast<BuiltinPtr>(ca_.SmiConstant(Builtins::k" +
-              instruction.external_name + "))");
+  const std::string str =
+      "ca_.UncheckedCast<BuiltinPtr>(ca_.SmiConstant(Builtins::k" +
+      instruction.external_name + "))";
+  stack->Push(str);
+  SetDefinitionVariable(instruction.GetValueDefinition(), str);
 }
 
 void CSAGenerator::EmitInstruction(
@@ -119,26 +172,28 @@ void CSAGenerator::EmitInstruction(
     Stack<std::string>* stack) {
   const Type* type = instruction.constant->type();
   std::vector<std::string> results;
-  for (const Type* lowered : LowerType(type)) {
-    results.push_back(FreshNodeName());
+
+  const auto lowered = LowerType(type);
+  for (std::size_t i = 0; i < lowered.size(); ++i) {
+    results.push_back(DefinitionToVariable(instruction.GetValueDefinition(i)));
     stack->Push(results.back());
-    out_ << "    TNode<" << lowered->GetGeneratedTNodeTypeName() << "> "
-         << stack->Top() << ";\n";
-    out_ << "    USE(" << stack->Top() << ");\n";
-  }
-  out_ << "    ";
-  if (type->IsStructType()) {
-    out_ << "std::tie(";
-    PrintCommaSeparatedList(out_, results);
-    out_ << ") = ";
+    decls() << "  TNode<" << lowered[i]->GetGeneratedTNodeTypeName() << "> "
+            << stack->Top() << ";\n";
+  }
+
+  out() << "    ";
+  if (type->StructSupertype()) {
+    out() << "std::tie(";
+    PrintCommaSeparatedList(out(), results);
+    out() << ") = ";
   } else if (results.size() == 1) {
-    out_ << results[0] << " = ";
+    out() << results[0] << " = ";
   }
-  out_ << instruction.constant->external_name() << "(state_)";
-  if (type->IsStructType()) {
-    out_ << ".Flatten();\n";
+  out() << instruction.constant->external_name() << "(state_)";
+  if (type->StructSupertype()) {
+    out() << ".Flatten();\n";
   } else {
-    out_ << ";\n";
+    out() << ";\n";
   }
 }
 
@@ -175,22 +230,23 @@ void CSAGenerator::EmitInstruction(const CallIntrinsicInstruction& instruction,
   Stack<std::string> pre_call_stack = *stack;
   const Type* return_type = instruction.intrinsic->signature().return_type;
   std::vector<std::string> results;
-  for (const Type* type : LowerType(return_type)) {
-    results.push_back(FreshNodeName());
+
+  const auto lowered = LowerType(return_type);
+  for (std::size_t i = 0; i < lowered.size(); ++i) {
+    results.push_back(DefinitionToVariable(instruction.GetValueDefinition(i)));
     stack->Push(results.back());
-    out_ << "    TNode<" << type->GetGeneratedTNodeTypeName() << "> "
-         << stack->Top() << ";\n";
-    out_ << "    USE(" << stack->Top() << ");\n";
+    decls() << "  TNode<" << lowered[i]->GetGeneratedTNodeTypeName() << "> "
+            << stack->Top() << ";\n";
   }
-  out_ << "    ";
 
-  if (return_type->IsStructType()) {
-    out_ << "std::tie(";
-    PrintCommaSeparatedList(out_, results);
-    out_ << ") = ";
+  out() << "    ";
+  if (return_type->StructSupertype()) {
+    out() << "std::tie(";
+    PrintCommaSeparatedList(out(), results);
+    out() << ") = ";
   } else {
     if (results.size() == 1) {
-      out_ << results[0] << " = ";
+      out() << results[0] << " = ";
     }
   }
 
@@ -207,13 +263,14 @@ void CSAGenerator::EmitInstruction(const CallIntrinsicInstruction& instruction,
       ReportError("%RawDownCast error: ", *return_type, " is not a subtype of ",
                   *original_type);
     }
-    if (return_type->GetGeneratedTNodeTypeName() !=
-        original_type->GetGeneratedTNodeTypeName()) {
+    if (!original_type->StructSupertype() &&
+        return_type->GetGeneratedTNodeTypeName() !=
+            original_type->GetGeneratedTNodeTypeName()) {
       if (return_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
-        out_ << "TORQUE_CAST";
+        out() << "TORQUE_CAST";
       } else {
-        out_ << "ca_.UncheckedCast<" << return_type->GetGeneratedTNodeTypeName()
-             << ">";
+        out() << "ca_.UncheckedCast<"
+              << return_type->GetGeneratedTNodeTypeName() << ">";
       }
     }
   } else if (instruction.intrinsic->ExternalName() == "%FromConstexpr") {
@@ -226,25 +283,25 @@ void CSAGenerator::EmitInstruction(const CallIntrinsicInstruction& instruction,
       ReportError("%FromConstexpr must return a non-constexpr type");
     }
     if (return_type->IsSubtypeOf(TypeOracle::GetSmiType())) {
-      out_ << "ca_.SmiConstant";
+      out() << "ca_.SmiConstant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetNumberType())) {
-      out_ << "ca_.NumberConstant";
+      out() << "ca_.NumberConstant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetStringType())) {
-      out_ << "ca_.StringConstant";
+      out() << "ca_.StringConstant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetObjectType())) {
       ReportError(
           "%FromConstexpr cannot cast to subclass of HeapObject unless it's a "
           "String or Number");
     } else if (return_type->IsSubtypeOf(TypeOracle::GetIntPtrType())) {
-      out_ << "ca_.IntPtrConstant";
+      out() << "ca_.IntPtrConstant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetUIntPtrType())) {
-      out_ << "ca_.UintPtrConstant";
+      out() << "ca_.UintPtrConstant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetInt32Type())) {
-      out_ << "ca_.Int32Constant";
+      out() << "ca_.Int32Constant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetUint32Type())) {
-      out_ << "ca_.Uint32Constant";
+      out() << "ca_.Uint32Constant";
     } else if (return_type->IsSubtypeOf(TypeOracle::GetBoolType())) {
-      out_ << "ca_.BoolConstant";
+      out() << "ca_.BoolConstant";
     } else {
       std::stringstream s;
       s << "%FromConstexpr does not support return type " << *return_type;
@@ -252,21 +309,21 @@ void CSAGenerator::EmitInstruction(const CallIntrinsicInstruction& instruction,
     }
     // Wrap the raw constexpr value in a static_cast to ensure that
     // enums get properly casted to their backing integral value.
-    out_ << "(CastToUnderlyingTypeIfEnum";
+    out() << "(CastToUnderlyingTypeIfEnum";
   } else {
     ReportError("no built in intrinsic with name " +
                 instruction.intrinsic->ExternalName());
   }
 
-  out_ << "(";
-  PrintCommaSeparatedList(out_, args);
+  out() << "(";
+  PrintCommaSeparatedList(out(), args);
   if (instruction.intrinsic->ExternalName() == "%FromConstexpr") {
-    out_ << ")";
+    out() << ")";
   }
-  if (return_type->IsStructType()) {
-    out_ << ").Flatten();\n";
+  if (return_type->StructSupertype()) {
+    out() << ").Flatten();\n";
   } else {
-    out_ << ");\n";
+    out() << ");\n";
   }
 }
 
@@ -282,42 +339,45 @@ void CSAGenerator::EmitInstruction(const CallCsaMacroInstruction& instruction,
   Stack<std::string> pre_call_stack = *stack;
   const Type* return_type = instruction.macro->signature().return_type;
   std::vector<std::string> results;
-  for (const Type* type : LowerType(return_type)) {
-    results.push_back(FreshNodeName());
+
+  const auto lowered = LowerType(return_type);
+  for (std::size_t i = 0; i < lowered.size(); ++i) {
+    results.push_back(DefinitionToVariable(instruction.GetValueDefinition(i)));
     stack->Push(results.back());
-    out_ << "    TNode<" << type->GetGeneratedTNodeTypeName() << "> "
-         << stack->Top() << ";\n";
-    out_ << "    USE(" << stack->Top() << ");\n";
+    decls() << "  TNode<" << lowered[i]->GetGeneratedTNodeTypeName() << "> "
+            << stack->Top() << ";\n";
   }
+
   std::string catch_name =
       PreCallableExceptionPreparation(instruction.catch_block);
-  out_ << "    ";
-  bool needs_flattening = return_type->IsStructType();
+  out() << "    ";
+  bool needs_flattening = return_type->StructSupertype().has_value();
   if (needs_flattening) {
-    out_ << "std::tie(";
-    PrintCommaSeparatedList(out_, results);
-    out_ << ") = ";
+    out() << "std::tie(";
+    PrintCommaSeparatedList(out(), results);
+    out() << ") = ";
   } else {
     if (results.size() == 1) {
-      out_ << results[0] << " = ";
+      out() << results[0] << " = ";
     } else {
       DCHECK_EQ(0, results.size());
     }
   }
   if (ExternMacro* extern_macro = ExternMacro::DynamicCast(instruction.macro)) {
-    out_ << extern_macro->external_assembler_name() << "(state_).";
+    out() << extern_macro->external_assembler_name() << "(state_).";
   } else {
     args.insert(args.begin(), "state_");
   }
-  out_ << instruction.macro->ExternalName() << "(";
-  PrintCommaSeparatedList(out_, args);
+  out() << instruction.macro->ExternalName() << "(";
+  PrintCommaSeparatedList(out(), args);
   if (needs_flattening) {
-    out_ << ").Flatten();\n";
+    out() << ").Flatten();\n";
   } else {
-    out_ << ");\n";
+    out() << ");\n";
   }
   PostCallableExceptionPreparation(catch_name, return_type,
-                                   instruction.catch_block, &pre_call_stack);
+                                   instruction.catch_block, &pre_call_stack,
+                                   instruction.GetExceptionObjectDefinition());
 }
 
 void CSAGenerator::EmitInstruction(
@@ -333,13 +393,14 @@ void CSAGenerator::EmitInstruction(
   Stack<std::string> pre_call_stack = *stack;
   std::vector<std::string> results;
   const Type* return_type = instruction.macro->signature().return_type;
+
   if (return_type != TypeOracle::GetNeverType()) {
-    for (const Type* type :
-         LowerType(instruction.macro->signature().return_type)) {
-      results.push_back(FreshNodeName());
-      out_ << "    TNode<" << type->GetGeneratedTNodeTypeName() << "> "
-           << results.back() << ";\n";
-      out_ << "    USE(" << results.back() << ");\n";
+    const auto lowered = LowerType(return_type);
+    for (std::size_t i = 0; i < lowered.size(); ++i) {
+      results.push_back(
+          DefinitionToVariable(instruction.GetValueDefinition(i)));
+      decls() << "  TNode<" << lowered[i]->GetGeneratedTNodeTypeName() << "> "
+              << results.back() << ";\n";
     }
   }
 
@@ -349,77 +410,97 @@ void CSAGenerator::EmitInstruction(
   DCHECK_EQ(labels.size(), instruction.label_blocks.size());
   for (size_t i = 0; i < labels.size(); ++i) {
     TypeVector label_parameters = labels[i].types;
-    label_names.push_back("label" + std::to_string(i));
+    label_names.push_back(FreshLabelName());
     var_names.push_back({});
     for (size_t j = 0; j < label_parameters.size(); ++j) {
-      var_names[i].push_back("result_" + std::to_string(i) + "_" +
-                             std::to_string(j));
-      out_ << "    compiler::TypedCodeAssemblerVariable<"
-           << label_parameters[j]->GetGeneratedTNodeTypeName() << "> "
-           << var_names[i][j] << "(&ca_);\n";
+      var_names[i].push_back(FreshNodeName());
+      const auto def = instruction.GetLabelValueDefinition(i, j);
+      SetDefinitionVariable(def, var_names[i].back() + ".value()");
+      decls() << "    compiler::TypedCodeAssemblerVariable<"
+              << label_parameters[j]->GetGeneratedTNodeTypeName() << "> "
+              << var_names[i][j] << "(&ca_);\n";
     }
-    out_ << "    compiler::CodeAssemblerLabel " << label_names[i]
-         << "(&ca_);\n";
+    out() << "    compiler::CodeAssemblerLabel " << label_names[i]
+          << "(&ca_);\n";
   }
 
   std::string catch_name =
       PreCallableExceptionPreparation(instruction.catch_block);
-  out_ << "    ";
+  out() << "    ";
   if (results.size() == 1) {
-    out_ << results[0] << " = ";
+    out() << results[0] << " = ";
   } else if (results.size() > 1) {
-    out_ << "std::tie(";
-    PrintCommaSeparatedList(out_, results);
-    out_ << ") = ";
+    out() << "std::tie(";
+    PrintCommaSeparatedList(out(), results);
+    out() << ") = ";
   }
   if (ExternMacro* extern_macro = ExternMacro::DynamicCast(instruction.macro)) {
-    out_ << extern_macro->external_assembler_name() << "(state_).";
+    out() << extern_macro->external_assembler_name() << "(state_).";
   } else {
     args.insert(args.begin(), "state_");
   }
-  out_ << instruction.macro->ExternalName() << "(";
-  PrintCommaSeparatedList(out_, args);
+  out() << instruction.macro->ExternalName() << "(";
+  PrintCommaSeparatedList(out(), args);
   bool first = args.empty();
   for (size_t i = 0; i < label_names.size(); ++i) {
-    if (!first) out_ << ", ";
-    out_ << "&" << label_names[i];
+    if (!first) out() << ", ";
+    out() << "&" << label_names[i];
     first = false;
     for (size_t j = 0; j < var_names[i].size(); ++j) {
-      out_ << ", &" << var_names[i][j];
+      out() << ", &" << var_names[i][j];
     }
   }
-  if (return_type->IsStructType()) {
-    out_ << ").Flatten();\n";
+  if (return_type->StructSupertype()) {
+    out() << ").Flatten();\n";
   } else {
-    out_ << ");\n";
+    out() << ");\n";
   }
 
   PostCallableExceptionPreparation(catch_name, return_type,
-                                   instruction.catch_block, &pre_call_stack);
+                                   instruction.catch_block, &pre_call_stack,
+                                   instruction.GetExceptionObjectDefinition());
 
   if (instruction.return_continuation) {
-    out_ << "    ca_.Goto(&" << BlockName(*instruction.return_continuation);
-    for (const std::string& value : *stack) {
-      out_ << ", " << value;
-    }
-    for (const std::string& result : results) {
-      out_ << ", " << result;
+    out() << "    ca_.Goto(&" << BlockName(*instruction.return_continuation);
+    DCHECK_EQ(stack->Size() + results.size(),
+              (*instruction.return_continuation)->InputDefinitions().Size());
+
+    const auto& input_definitions =
+        (*instruction.return_continuation)->InputDefinitions();
+    for (BottomOffset i = 0; i < input_definitions.AboveTop(); ++i) {
+      if (input_definitions.Peek(i).IsPhiFromBlock(
+              *instruction.return_continuation)) {
+        out() << ", "
+              << (i < stack->AboveTop() ? stack->Peek(i) : results[i.offset]);
+      }
     }
-    out_ << ");\n";
-  }
-  for (size_t i = 0; i < label_names.size(); ++i) {
-    out_ << "    if (" << label_names[i] << ".is_used()) {\n";
-    out_ << "      ca_.Bind(&" << label_names[i] << ");\n";
-    out_ << "      ca_.Goto(&" << BlockName(instruction.label_blocks[i]);
-    for (const std::string& value : *stack) {
-      out_ << ", " << value;
+    out() << ");\n";
+  }
+  for (size_t l = 0; l < label_names.size(); ++l) {
+    out() << "    if (" << label_names[l] << ".is_used()) {\n";
+    out() << "      ca_.Bind(&" << label_names[l] << ");\n";
+    out() << "      ca_.Goto(&" << BlockName(instruction.label_blocks[l]);
+    DCHECK_EQ(stack->Size() + var_names[l].size(),
+              instruction.label_blocks[l]->InputDefinitions().Size());
+
+    const auto& label_definitions =
+        instruction.label_blocks[l]->InputDefinitions();
+
+    BottomOffset i = 0;
+    for (; i < stack->AboveTop(); ++i) {
+      if (label_definitions.Peek(i).IsPhiFromBlock(
+              instruction.label_blocks[l])) {
+        out() << ", " << stack->Peek(i);
+      }
     }
-    for (const std::string& var : var_names[i]) {
-      out_ << ", " << var << ".value()";
+    for (std::size_t k = 0; k < var_names[l].size(); ++k, ++i) {
+      if (label_definitions.Peek(i).IsPhiFromBlock(
+              instruction.label_blocks[l])) {
+        out() << ", " << var_names[l][k] << ".value()";
+      }
     }
-    out_ << ");\n";
-
-    out_ << "    }\n";
+    out() << ");\n";
+    out() << "    }\n";
   }
 }
 
@@ -429,15 +510,16 @@ void CSAGenerator::EmitInstruction(const CallBuiltinInstruction& instruction,
   std::vector<const Type*> result_types =
       LowerType(instruction.builtin->signature().return_type);
   if (instruction.is_tailcall) {
-    out_ << "   CodeStubAssembler(state_).TailCallBuiltin(Builtins::k"
-         << instruction.builtin->ExternalName() << ", ";
-    PrintCommaSeparatedList(out_, arguments);
-    out_ << ");\n";
+    out() << "   CodeStubAssembler(state_).TailCallBuiltin(Builtins::k"
+          << instruction.builtin->ExternalName() << ", ";
+    PrintCommaSeparatedList(out(), arguments);
+    out() << ");\n";
   } else {
-    std::string result_name = FreshNodeName();
+    std::string result_name;
     if (result_types.size() == 1) {
-      out_ << "    TNode<" << result_types[0]->GetGeneratedTNodeTypeName()
-           << "> " << result_name << ";\n";
+      result_name = DefinitionToVariable(instruction.GetValueDefinition(0));
+      decls() << "  TNode<" << result_types[0]->GetGeneratedTNodeTypeName()
+              << "> " << result_name << ";\n";
     }
     std::string catch_name =
         PreCallableExceptionPreparation(instruction.catch_block);
@@ -445,27 +527,27 @@ void CSAGenerator::EmitInstruction(const CallBuiltinInstruction& instruction,
     if (result_types.size() == 1) {
       std::string generated_type = result_types[0]->GetGeneratedTNodeTypeName();
       stack->Push(result_name);
-      out_ << "    " << result_name << " = ";
-      if (generated_type != "Object") out_ << "TORQUE_CAST(";
-      out_ << "CodeStubAssembler(state_).CallBuiltin(Builtins::k"
-           << instruction.builtin->ExternalName() << ", ";
-      PrintCommaSeparatedList(out_, arguments);
-      if (generated_type != "Object") out_ << ")";
-      out_ << ");\n";
-      out_ << "    USE(" << result_name << ");\n";
+      out() << "    " << result_name << " = ";
+      if (generated_type != "Object") out() << "TORQUE_CAST(";
+      out() << "CodeStubAssembler(state_).CallBuiltin(Builtins::k"
+            << instruction.builtin->ExternalName() << ", ";
+      PrintCommaSeparatedList(out(), arguments);
+      if (generated_type != "Object") out() << ")";
+      out() << ");\n";
     } else {
       DCHECK_EQ(0, result_types.size());
       // TODO(tebbi): Actually, builtins have to return a value, so we should
       // not have to handle this case.
-      out_ << "    CodeStubAssembler(state_).CallBuiltin(Builtins::k"
-           << instruction.builtin->ExternalName() << ", ";
-      PrintCommaSeparatedList(out_, arguments);
-      out_ << ");\n";
+      out() << "    CodeStubAssembler(state_).CallBuiltin(Builtins::k"
+            << instruction.builtin->ExternalName() << ", ";
+      PrintCommaSeparatedList(out(), arguments);
+      out() << ");\n";
     }
     PostCallableExceptionPreparation(
         catch_name,
         result_types.size() == 0 ? TypeOracle::GetVoidType() : result_types[0],
-        instruction.catch_block, &pre_call_stack);
+        instruction.catch_block, &pre_call_stack,
+        instruction.GetExceptionObjectDefinition());
   }
 }
 
@@ -483,20 +565,21 @@ void CSAGenerator::EmitInstruction(
     ReportError("tail-calls to builtin pointers are not supported");
   }
 
-  stack->Push(FreshNodeName());
+  DCHECK_EQ(1, instruction.GetValueDefinitionCount());
+  stack->Push(DefinitionToVariable(instruction.GetValueDefinition(0)));
   std::string generated_type = result_types[0]->GetGeneratedTNodeTypeName();
-  out_ << "    TNode<" << generated_type << "> " << stack->Top() << " = ";
-  if (generated_type != "Object") out_ << "TORQUE_CAST(";
-  out_ << "CodeStubAssembler(state_).CallBuiltinPointer(Builtins::"
-          "CallableFor(ca_."
-          "isolate(),"
-          "ExampleBuiltinForTorqueFunctionPointerType("
-       << instruction.type->function_pointer_type_id() << ")).descriptor(), ";
-  PrintCommaSeparatedList(out_, function_and_arguments);
-  out_ << ")";
-  if (generated_type != "Object") out_ << ")";
-  out_ << "; \n";
-  out_ << "    USE(" << stack->Top() << ");\n";
+  decls() << "  TNode<" << generated_type << "> " << stack->Top() << ";\n";
+  out() << stack->Top() << " = ";
+  if (generated_type != "Object") out() << "TORQUE_CAST(";
+  out() << "CodeStubAssembler(state_).CallBuiltinPointer(Builtins::"
+           "CallableFor(ca_."
+           "isolate(),"
+           "ExampleBuiltinForTorqueFunctionPointerType("
+        << instruction.type->function_pointer_type_id() << ")).descriptor(), ";
+  PrintCommaSeparatedList(out(), function_and_arguments);
+  out() << ")";
+  if (generated_type != "Object") out() << ")";
+  out() << ";\n";
 }
 
 std::string CSAGenerator::PreCallableExceptionPreparation(
@@ -504,38 +587,52 @@ std::string CSAGenerator::PreCallableExceptionPreparation(
   std::string catch_name;
   if (catch_block) {
     catch_name = FreshCatchName();
-    out_ << "    compiler::CodeAssemblerExceptionHandlerLabel " << catch_name
-         << "__label(&ca_, compiler::CodeAssemblerLabel::kDeferred);\n";
-    out_ << "    { compiler::CodeAssemblerScopedExceptionHandler s(&ca_, &"
-         << catch_name << "__label);\n";
+    out() << "    compiler::CodeAssemblerExceptionHandlerLabel " << catch_name
+          << "__label(&ca_, compiler::CodeAssemblerLabel::kDeferred);\n";
+    out() << "    { compiler::ScopedExceptionHandler s(&ca_, &" << catch_name
+          << "__label);\n";
   }
   return catch_name;
 }
 
 void CSAGenerator::PostCallableExceptionPreparation(
     const std::string& catch_name, const Type* return_type,
-    base::Optional<Block*> catch_block, Stack<std::string>* stack) {
+    base::Optional<Block*> catch_block, Stack<std::string>* stack,
+    const base::Optional<DefinitionLocation>& exception_object_definition) {
   if (catch_block) {
+    DCHECK(exception_object_definition);
     std::string block_name = BlockName(*catch_block);
-    out_ << "    }\n";
-    out_ << "    if (" << catch_name << "__label.is_used()) {\n";
-    out_ << "      compiler::CodeAssemblerLabel " << catch_name
-         << "_skip(&ca_);\n";
+    out() << "    }\n";
+    out() << "    if (" << catch_name << "__label.is_used()) {\n";
+    out() << "      compiler::CodeAssemblerLabel " << catch_name
+          << "_skip(&ca_);\n";
     if (!return_type->IsNever()) {
-      out_ << "      ca_.Goto(&" << catch_name << "_skip);\n";
+      out() << "      ca_.Goto(&" << catch_name << "_skip);\n";
     }
-    out_ << "      TNode<Object> " << catch_name << "_exception_object;\n";
-    out_ << "      ca_.Bind(&" << catch_name << "__label, &" << catch_name
-         << "_exception_object);\n";
-    out_ << "      ca_.Goto(&" << block_name;
-    for (size_t i = 0; i < stack->Size(); ++i) {
-      out_ << ", " << stack->begin()[i];
+    decls() << "      TNode<Object> "
+            << DefinitionToVariable(*exception_object_definition) << ";\n";
+    out() << "      ca_.Bind(&" << catch_name << "__label, &"
+          << DefinitionToVariable(*exception_object_definition) << ");\n";
+    out() << "      ca_.Goto(&" << block_name;
+
+    DCHECK_EQ(stack->Size() + 1, (*catch_block)->InputDefinitions().Size());
+    const auto& input_definitions = (*catch_block)->InputDefinitions();
+    for (BottomOffset i = 0; i < input_definitions.AboveTop(); ++i) {
+      if (input_definitions.Peek(i).IsPhiFromBlock(*catch_block)) {
+        if (i < stack->AboveTop()) {
+          out() << ", " << stack->Peek(i);
+        } else {
+          DCHECK_EQ(i, stack->AboveTop());
+          out() << ", " << DefinitionToVariable(*exception_object_definition);
+        }
+      }
     }
-    out_ << ", " << catch_name << "_exception_object);\n";
+    out() << ");\n";
+
     if (!return_type->IsNever()) {
-      out_ << "      ca_.Bind(&" << catch_name << "_skip);\n";
+      out() << "      ca_.Bind(&" << catch_name << "_skip);\n";
     }
-    out_ << "    }\n";
+    out() << "    }\n";
   }
 }
 
@@ -552,15 +649,16 @@ void CSAGenerator::EmitInstruction(const CallRuntimeInstruction& instruction,
     ReportError("runtime function must have at most one result");
   }
   if (instruction.is_tailcall) {
-    out_ << "    CodeStubAssembler(state_).TailCallRuntime(Runtime::k"
-         << instruction.runtime_function->ExternalName() << ", ";
-    PrintCommaSeparatedList(out_, arguments);
-    out_ << ");\n";
+    out() << "    CodeStubAssembler(state_).TailCallRuntime(Runtime::k"
+          << instruction.runtime_function->ExternalName() << ", ";
+    PrintCommaSeparatedList(out(), arguments);
+    out() << ");\n";
   } else {
-    std::string result_name = FreshNodeName();
+    std::string result_name;
     if (result_types.size() == 1) {
-      out_ << "    TNode<" << result_types[0]->GetGeneratedTNodeTypeName()
-           << "> " << result_name << ";\n";
+      result_name = DefinitionToVariable(instruction.GetValueDefinition(0));
+      decls() << "  TNode<" << result_types[0]->GetGeneratedTNodeTypeName()
+              << "> " << result_name << ";\n";
     }
     std::string catch_name =
         PreCallableExceptionPreparation(instruction.catch_block);
@@ -568,94 +666,132 @@ void CSAGenerator::EmitInstruction(const CallRuntimeInstruction& instruction,
     if (result_types.size() == 1) {
       std::string generated_type = result_types[0]->GetGeneratedTNodeTypeName();
       stack->Push(result_name);
-      out_ << "    " << result_name << " = ";
-      if (generated_type != "Object") out_ << "TORQUE_CAST(";
-      out_ << "CodeStubAssembler(state_).CallRuntime(Runtime::k"
-           << instruction.runtime_function->ExternalName() << ", ";
-      PrintCommaSeparatedList(out_, arguments);
-      out_ << ")";
-      if (generated_type != "Object") out_ << ")";
-      out_ << "; \n";
-      out_ << "    USE(" << result_name << ");\n";
+      out() << "    " << result_name << " = ";
+      if (generated_type != "Object") out() << "TORQUE_CAST(";
+      out() << "CodeStubAssembler(state_).CallRuntime(Runtime::k"
+            << instruction.runtime_function->ExternalName() << ", ";
+      PrintCommaSeparatedList(out(), arguments);
+      out() << ")";
+      if (generated_type != "Object") out() << ")";
+      out() << "; \n";
     } else {
       DCHECK_EQ(0, result_types.size());
-      out_ << "    CodeStubAssembler(state_).CallRuntime(Runtime::k"
-           << instruction.runtime_function->ExternalName() << ", ";
-      PrintCommaSeparatedList(out_, arguments);
-      out_ << ");\n";
+      out() << "    CodeStubAssembler(state_).CallRuntime(Runtime::k"
+            << instruction.runtime_function->ExternalName() << ", ";
+      PrintCommaSeparatedList(out(), arguments);
+      out() << ");\n";
       if (return_type == TypeOracle::GetNeverType()) {
-        out_ << "    CodeStubAssembler(state_).Unreachable();\n";
+        out() << "    CodeStubAssembler(state_).Unreachable();\n";
       } else {
         DCHECK(return_type == TypeOracle::GetVoidType());
       }
     }
-    PostCallableExceptionPreparation(catch_name, return_type,
-                                     instruction.catch_block, &pre_call_stack);
+    PostCallableExceptionPreparation(
+        catch_name, return_type, instruction.catch_block, &pre_call_stack,
+        instruction.GetExceptionObjectDefinition());
   }
 }
 
 void CSAGenerator::EmitInstruction(const BranchInstruction& instruction,
                                    Stack<std::string>* stack) {
-  out_ << "    ca_.Branch(" << stack->Pop() << ", &"
-       << BlockName(instruction.if_true) << ", &"
-       << BlockName(instruction.if_false);
-  for (const std::string& value : *stack) {
-    out_ << ", " << value;
+  out() << "    ca_.Branch(" << stack->Pop() << ", &"
+        << BlockName(instruction.if_true) << ", std::vector<Node*>{";
+
+  const auto& true_definitions = instruction.if_true->InputDefinitions();
+  DCHECK_EQ(stack->Size(), true_definitions.Size());
+  bool first = true;
+  for (BottomOffset i = 0; i < stack->AboveTop(); ++i) {
+    if (true_definitions.Peek(i).IsPhiFromBlock(instruction.if_true)) {
+      if (!first) out() << ", ";
+      out() << stack->Peek(i);
+      first = false;
+    }
   }
-  out_ << ");\n";
+
+  out() << "}, &" << BlockName(instruction.if_false) << ", std::vector<Node*>{";
+
+  const auto& false_definitions = instruction.if_false->InputDefinitions();
+  DCHECK_EQ(stack->Size(), false_definitions.Size());
+  first = true;
+  for (BottomOffset i = 0; i < stack->AboveTop(); ++i) {
+    if (false_definitions.Peek(i).IsPhiFromBlock(instruction.if_false)) {
+      if (!first) out() << ", ";
+      out() << stack->Peek(i);
+      first = false;
+    }
+  }
+
+  out() << "});\n";
 }
 
 void CSAGenerator::EmitInstruction(
     const ConstexprBranchInstruction& instruction, Stack<std::string>* stack) {
-  out_ << "    if ((" << instruction.condition << ")) {\n";
-  out_ << "      ca_.Goto(&" << BlockName(instruction.if_true);
-  for (const std::string& value : *stack) {
-    out_ << ", " << value;
+  out() << "    if ((" << instruction.condition << ")) {\n";
+  out() << "      ca_.Goto(&" << BlockName(instruction.if_true);
+
+  const auto& true_definitions = instruction.if_true->InputDefinitions();
+  DCHECK_EQ(stack->Size(), true_definitions.Size());
+  for (BottomOffset i = 0; i < stack->AboveTop(); ++i) {
+    if (true_definitions.Peek(i).IsPhiFromBlock(instruction.if_true)) {
+      out() << ", " << stack->Peek(i);
+    }
   }
-  out_ << ");\n";
-  out_ << "    } else {\n";
-  out_ << "      ca_.Goto(&" << BlockName(instruction.if_false);
-  for (const std::string& value : *stack) {
-    out_ << ", " << value;
+
+  out() << ");\n";
+  out() << "    } else {\n";
+  out() << "      ca_.Goto(&" << BlockName(instruction.if_false);
+
+  const auto& false_definitions = instruction.if_false->InputDefinitions();
+  DCHECK_EQ(stack->Size(), false_definitions.Size());
+  for (BottomOffset i = 0; i < stack->AboveTop(); ++i) {
+    if (false_definitions.Peek(i).IsPhiFromBlock(instruction.if_false)) {
+      out() << ", " << stack->Peek(i);
+    }
   }
-  out_ << ");\n";
 
-  out_ << "    }\n";
+  out() << ");\n";
+  out() << "    }\n";
 }
 
 void CSAGenerator::EmitInstruction(const GotoInstruction& instruction,
                                    Stack<std::string>* stack) {
-  out_ << "    ca_.Goto(&" << BlockName(instruction.destination);
-  for (const std::string& value : *stack) {
-    out_ << ", " << value;
+  out() << "    ca_.Goto(&" << BlockName(instruction.destination);
+  const auto& destination_definitions =
+      instruction.destination->InputDefinitions();
+  DCHECK_EQ(stack->Size(), destination_definitions.Size());
+  for (BottomOffset i = 0; i < stack->AboveTop(); ++i) {
+    if (destination_definitions.Peek(i).IsPhiFromBlock(
+            instruction.destination)) {
+      out() << ", " << stack->Peek(i);
+    }
   }
-  out_ << ");\n";
+  out() << ");\n";
 }
 
 void CSAGenerator::EmitInstruction(const GotoExternalInstruction& instruction,
                                    Stack<std::string>* stack) {
   for (auto it = instruction.variable_names.rbegin();
        it != instruction.variable_names.rend(); ++it) {
-    out_ << "    *" << *it << " = " << stack->Pop() << ";\n";
+    out() << "    *" << *it << " = " << stack->Pop() << ";\n";
   }
-  out_ << "    ca_.Goto(" << instruction.destination << ");\n";
+  out() << "    ca_.Goto(" << instruction.destination << ");\n";
 }
 
 void CSAGenerator::EmitInstruction(const ReturnInstruction& instruction,
                                    Stack<std::string>* stack) {
   if (*linkage_ == Builtin::kVarArgsJavaScript) {
-    out_ << "    " << ARGUMENTS_VARIABLE_STRING << ".PopAndReturn(";
+    out() << "    " << ARGUMENTS_VARIABLE_STRING << ".PopAndReturn(";
   } else {
-    out_ << "    CodeStubAssembler(state_).Return(";
+    out() << "    CodeStubAssembler(state_).Return(";
   }
-  out_ << stack->Pop() << ");\n";
+  out() << stack->Pop() << ");\n";
 }
 
 void CSAGenerator::EmitInstruction(
     const PrintConstantStringInstruction& instruction,
     Stack<std::string>* stack) {
-  out_ << "    CodeStubAssembler(state_).Print("
-       << StringLiteralQuote(instruction.message) << ");\n";
+  out() << "    CodeStubAssembler(state_).Print("
+        << StringLiteralQuote(instruction.message) << ");\n";
 }
 
 void CSAGenerator::EmitInstruction(const AbortInstruction& instruction,
@@ -663,18 +799,18 @@ void CSAGenerator::EmitInstruction(const AbortInstruction& instruction,
   switch (instruction.kind) {
     case AbortInstruction::Kind::kUnreachable:
       DCHECK(instruction.message.empty());
-      out_ << "    CodeStubAssembler(state_).Unreachable();\n";
+      out() << "    CodeStubAssembler(state_).Unreachable();\n";
       break;
     case AbortInstruction::Kind::kDebugBreak:
       DCHECK(instruction.message.empty());
-      out_ << "    CodeStubAssembler(state_).DebugBreak();\n";
+      out() << "    CodeStubAssembler(state_).DebugBreak();\n";
       break;
     case AbortInstruction::Kind::kAssertionFailure: {
       std::string file = StringLiteralQuote(
           SourceFileMap::PathFromV8Root(instruction.pos.source));
-      out_ << "    CodeStubAssembler(state_).FailAssert("
-           << StringLiteralQuote(instruction.message) << ", " << file << ", "
-           << instruction.pos.start.line + 1 << ");\n";
+      out() << "    CodeStubAssembler(state_).FailAssert("
+            << StringLiteralQuote(instruction.message) << ", " << file << ", "
+            << instruction.pos.start.line + 1 << ");\n";
       break;
     }
   }
@@ -682,25 +818,30 @@ void CSAGenerator::EmitInstruction(const AbortInstruction& instruction,
 
 void CSAGenerator::EmitInstruction(const UnsafeCastInstruction& instruction,
                                    Stack<std::string>* stack) {
-  stack->Poke(stack->AboveTop() - 1,
-              "ca_.UncheckedCast<" +
-                  instruction.destination_type->GetGeneratedTNodeTypeName() +
-                  ">(" + stack->Top() + ")");
+  const std::string str =
+      "ca_.UncheckedCast<" +
+      instruction.destination_type->GetGeneratedTNodeTypeName() + ">(" +
+      stack->Top() + ")";
+  stack->Poke(stack->AboveTop() - 1, str);
+  SetDefinitionVariable(instruction.GetValueDefinition(), str);
 }
 
 void CSAGenerator::EmitInstruction(const LoadReferenceInstruction& instruction,
                                    Stack<std::string>* stack) {
-  std::string result_name = FreshNodeName();
+  std::string result_name =
+      DefinitionToVariable(instruction.GetValueDefinition());
 
   std::string offset = stack->Pop();
   std::string object = stack->Pop();
   stack->Push(result_name);
 
-  out_ << "    " << instruction.type->GetGeneratedTypeName() << result_name
-       << " = CodeStubAssembler(state_).LoadReference<"
-       << instruction.type->GetGeneratedTNodeTypeName()
-       << ">(CodeStubAssembler::Reference{" << object << ", " << offset
-       << "});\n";
+  decls() << "  " << instruction.type->GetGeneratedTypeName() << " "
+          << result_name << ";\n";
+  out() << "    " << result_name
+        << " = CodeStubAssembler(state_).LoadReference<"
+        << instruction.type->GetGeneratedTNodeTypeName()
+        << ">(CodeStubAssembler::Reference{" << object << ", " << offset
+        << "});\n";
 }
 
 void CSAGenerator::EmitInstruction(const StoreReferenceInstruction& instruction,
@@ -709,25 +850,29 @@ void CSAGenerator::EmitInstruction(const StoreReferenceInstruction& instruction,
   std::string offset = stack->Pop();
   std::string object = stack->Pop();
 
-  out_ << "    CodeStubAssembler(state_).StoreReference<"
-       << instruction.type->GetGeneratedTNodeTypeName()
-       << ">(CodeStubAssembler::"
-          "Reference{"
-       << object << ", " << offset << "}, " << value << ");\n";
+  out() << "    CodeStubAssembler(state_).StoreReference<"
+        << instruction.type->GetGeneratedTNodeTypeName()
+        << ">(CodeStubAssembler::"
+           "Reference{"
+        << object << ", " << offset << "}, " << value << ");\n";
 }
 
 namespace {
 std::string GetBitFieldSpecialization(const BitFieldStructType* container,
                                       const BitField& field) {
-  std::string suffix = field.num_bits == 1 ? "Bit" : "Bits";
-  return "TorqueGenerated" + container->name() +
-         "Fields::" + CamelifyString(field.name_and_type.name) + suffix;
+  std::stringstream stream;
+  stream << "base::BitField<"
+         << field.name_and_type.type->GetConstexprGeneratedTypeName() << ", "
+         << field.offset << ", " << field.num_bits << ", "
+         << container->GetConstexprGeneratedTypeName() << ">";
+  return stream.str();
 }
 }  // namespace
 
 void CSAGenerator::EmitInstruction(const LoadBitFieldInstruction& instruction,
                                    Stack<std::string>* stack) {
-  std::string result_name = FreshNodeName();
+  std::string result_name =
+      DefinitionToVariable(instruction.GetValueDefinition());
 
   std::string bit_field_struct = stack->Pop();
   stack->Push(result_name);
@@ -742,17 +887,20 @@ void CSAGenerator::EmitInstruction(const LoadBitFieldInstruction& instruction,
           ? (result_uintptr ? "DecodeWord" : "DecodeWord32FromWord")
           : (result_uintptr ? "DecodeWordFromWord32" : "DecodeWord32");
 
-  out_ << "    " << result_type->GetGeneratedTypeName() << result_name
-       << " = ca_.UncheckedCast<" << result_type->GetGeneratedTNodeTypeName()
-       << ">(CodeStubAssembler(state_)." << decoder << "<"
-       << GetBitFieldSpecialization(source_type, instruction.bit_field)
-       << ">(ca_.UncheckedCast<" << source_word_type << ">(" << bit_field_struct
-       << ")));\n";
+  decls() << "  " << result_type->GetGeneratedTypeName() << " " << result_name
+          << ";\n";
+  out() << "    " << result_name << " = ca_.UncheckedCast<"
+        << result_type->GetGeneratedTNodeTypeName()
+        << ">(CodeStubAssembler(state_)." << decoder << "<"
+        << GetBitFieldSpecialization(source_type, instruction.bit_field)
+        << ">(ca_.UncheckedCast<" << source_word_type << ">("
+        << bit_field_struct << ")));\n";
 }
 
 void CSAGenerator::EmitInstruction(const StoreBitFieldInstruction& instruction,
                                    Stack<std::string>* stack) {
-  std::string result_name = FreshNodeName();
+  std::string result_name =
+      DefinitionToVariable(instruction.GetValueDefinition());
 
   std::string value = stack->Pop();
   std::string bit_field_struct = stack->Pop();
@@ -768,13 +916,15 @@ void CSAGenerator::EmitInstruction(const StoreBitFieldInstruction& instruction,
       struct_uintptr ? (field_uintptr ? "UpdateWord" : "UpdateWord32InWord")
                      : (field_uintptr ? "UpdateWordInWord32" : "UpdateWord32");
 
-  out_ << "    " << struct_type->GetGeneratedTypeName() << result_name
-       << " = ca_.UncheckedCast<" << struct_type->GetGeneratedTNodeTypeName()
-       << ">(CodeStubAssembler(state_)." << encoder << "<"
-       << GetBitFieldSpecialization(struct_type, instruction.bit_field)
-       << ">(ca_.UncheckedCast<" << struct_word_type << ">(" << bit_field_struct
-       << "), ca_.UncheckedCast<" << field_word_type << ">(" << value
-       << ")));\n";
+  decls() << "  " << struct_type->GetGeneratedTypeName() << " " << result_name
+          << ";\n";
+  out() << "    " << result_name << " = ca_.UncheckedCast<"
+        << struct_type->GetGeneratedTNodeTypeName()
+        << ">(CodeStubAssembler(state_)." << encoder << "<"
+        << GetBitFieldSpecialization(struct_type, instruction.bit_field)
+        << ">(ca_.UncheckedCast<" << struct_word_type << ">("
+        << bit_field_struct << "), ca_.UncheckedCast<" << field_word_type
+        << ">(" << value << ")));\n";
 }
 
 // static
@@ -783,10 +933,10 @@ void CSAGenerator::EmitCSAValue(VisitResult result,
                                 std::ostream& out) {
   if (!result.IsOnStack()) {
     out << result.constexpr_value();
-  } else if (auto* struct_type = StructType::DynamicCast(result.type())) {
-    out << struct_type->GetGeneratedTypeName() << "{";
+  } else if (auto struct_type = result.type()->StructSupertype()) {
+    out << (*struct_type)->GetGeneratedTypeName() << "{";
     bool first = true;
-    for (auto& field : struct_type->fields()) {
+    for (auto& field : (*struct_type)->fields()) {
       if (!first) {
         out << ", ";
       }
diff --git a/deps/v8/src/torque/csa-generator.h b/deps/v8/src/torque/csa-generator.h
index 5790d9434c..83c4ec410a 100644
--- a/deps/v8/src/torque/csa-generator.h
+++ b/deps/v8/src/torque/csa-generator.h
@@ -19,7 +19,8 @@ class CSAGenerator {
   CSAGenerator(const ControlFlowGraph& cfg, std::ostream& out,
                base::Optional<Builtin::Kind> linkage = base::nullopt)
       : cfg_(cfg),
-        out_(out),
+        out_(&out),
+        out_decls_(&out),
         linkage_(linkage),
         previous_position_(SourcePosition::Invalid()) {}
   base::Optional<Stack<std::string>> EmitGraph(Stack<std::string> parameters);
@@ -31,22 +32,56 @@ class CSAGenerator {
 
  private:
   const ControlFlowGraph& cfg_;
-  std::ostream& out_;
+  std::ostream* out_;
+  std::ostream* out_decls_;
   size_t fresh_id_ = 0;
   base::Optional<Builtin::Kind> linkage_;
   SourcePosition previous_position_;
+  std::map<DefinitionLocation, std::string> location_map_;
 
+  std::string DefinitionToVariable(const DefinitionLocation& location) {
+    if (location.IsPhi()) {
+      std::stringstream stream;
+      stream << "phi_bb" << location.GetPhiBlock()->id() << "_"
+             << location.GetPhiIndex();
+      return stream.str();
+    } else if (location.IsParameter()) {
+      auto it = location_map_.find(location);
+      DCHECK_NE(it, location_map_.end());
+      return it->second;
+    } else {
+      DCHECK(location.IsInstruction());
+      auto it = location_map_.find(location);
+      if (it == location_map_.end()) {
+        it = location_map_.insert(std::make_pair(location, FreshNodeName()))
+                 .first;
+      }
+      return it->second;
+    }
+  }
+
+  void SetDefinitionVariable(const DefinitionLocation& definition,
+                             const std::string& str) {
+    DCHECK_EQ(location_map_.find(definition), location_map_.end());
+    location_map_.insert(std::make_pair(definition, str));
+  }
+
+  std::ostream& out() { return *out_; }
+  std::ostream& decls() { return *out_decls_; }
+
+  bool IsEmptyInstruction(const Instruction& instruction);
   void EmitSourcePosition(SourcePosition pos, bool always_emit = false);
 
   std::string PreCallableExceptionPreparation(
       base::Optional<Block*> catch_block);
-  void PostCallableExceptionPreparation(const std::string& catch_name,
-                                        const Type* return_type,
-                                        base::Optional<Block*> catch_block,
-                                        Stack<std::string>* stack);
+  void PostCallableExceptionPreparation(
+      const std::string& catch_name, const Type* return_type,
+      base::Optional<Block*> catch_block, Stack<std::string>* stack,
+      const base::Optional<DefinitionLocation>& exception_object_definition);
 
   std::string FreshNodeName() { return "tmp" + std::to_string(fresh_id_++); }
   std::string FreshCatchName() { return "catch" + std::to_string(fresh_id_++); }
+  std::string FreshLabelName() { return "label" + std::to_string(fresh_id_++); }
   std::string BlockName(const Block* block) {
     return "block" + std::to_string(block->id());
   }
diff --git a/deps/v8/src/torque/declarable.h b/deps/v8/src/torque/declarable.h
index fe9a522b18..b6fdef67b9 100644
--- a/deps/v8/src/torque/declarable.h
+++ b/deps/v8/src/torque/declarable.h
@@ -340,7 +340,7 @@ class Macro : public Callable {
   bool ShouldBeInlined() const override {
     for (const LabelDeclaration& label : signature().labels) {
       for (const Type* type : label.types) {
-        if (type->IsStructType()) return true;
+        if (type->StructSupertype()) return true;
       }
     }
     // Intrinsics that are used internally in Torque and implemented as torque
diff --git a/deps/v8/src/torque/declaration-visitor.cc b/deps/v8/src/torque/declaration-visitor.cc
index 32c566ce8a..5e3c8bbcb2 100644
--- a/deps/v8/src/torque/declaration-visitor.cc
+++ b/deps/v8/src/torque/declaration-visitor.cc
@@ -91,18 +91,16 @@ Builtin* DeclarationVisitor::CreateBuiltin(BuiltinDeclaration* decl,
   }
 
   for (size_t i = 0; i < signature.types().size(); ++i) {
-    if (const StructType* type =
-            StructType::DynamicCast(signature.types()[i])) {
-      Error("Builtin '", decl->name, "' uses the struct '", type->name(),
-            "' as argument '", signature.parameter_names[i],
-            "', which is not supported.");
+    if (signature.types()[i]->StructSupertype()) {
+      Error("Builtin do not support structs as arguments, but argument ",
+            signature.parameter_names[i], " has type ", *signature.types()[i],
+            ".");
     }
   }
 
-  if (const StructType* struct_type =
-          StructType::DynamicCast(signature.return_type)) {
-    Error("Builtins ", decl->name, " cannot return structs ",
-          struct_type->name());
+  if (signature.return_type->StructSupertype()) {
+    Error("Builtins cannot return structs, but the return type is ",
+          *signature.return_type, ".");
   }
 
   return Declarations::CreateBuiltin(std::move(external_name),
diff --git a/deps/v8/src/torque/global-context.h b/deps/v8/src/torque/global-context.h
index bb84f9bdf4..bbfbb686ef 100644
--- a/deps/v8/src/torque/global-context.h
+++ b/deps/v8/src/torque/global-context.h
@@ -35,15 +35,6 @@ class GlobalContext : public ContextualClass<GlobalContext> {
     return Get().declarables_;
   }
 
-  static void RegisterClass(const TypeAlias* alias) {
-    DCHECK(alias->ParentScope()->IsNamespace());
-    Get().classes_.push_back(alias);
-  }
-
-  using GlobalClassList = std::vector<const TypeAlias*>;
-
-  static const GlobalClassList& GetClasses() { return Get().classes_; }
-
   static void AddCppInclude(std::string include_path) {
     Get().cpp_includes_.insert(std::move(include_path));
   }
@@ -84,7 +75,6 @@ class GlobalContext : public ContextualClass<GlobalContext> {
   std::vector<std::unique_ptr<Declarable>> declarables_;
   std::set<std::string> cpp_includes_;
   std::map<SourceId, PerFileStreams> generated_per_file_;
-  GlobalClassList classes_;
   std::map<std::string, size_t> fresh_ids_;
 
   friend class LanguageServerData;
diff --git a/deps/v8/src/torque/implementation-visitor.cc b/deps/v8/src/torque/implementation-visitor.cc
index ae6ceb3ccf..820576e02a 100644
--- a/deps/v8/src/torque/implementation-visitor.cc
+++ b/deps/v8/src/torque/implementation-visitor.cc
@@ -3,15 +3,19 @@
 // found in the LICENSE file.
 
 #include <algorithm>
+#include <string>
 
+#include "src/base/optional.h"
 #include "src/common/globals.h"
 #include "src/torque/csa-generator.h"
 #include "src/torque/declaration-visitor.h"
+#include "src/torque/global-context.h"
 #include "src/torque/implementation-visitor.h"
 #include "src/torque/parameter-difference.h"
 #include "src/torque/server-data.h"
 #include "src/torque/type-inference.h"
 #include "src/torque/type-visitor.h"
+#include "src/torque/types.h"
 
 namespace v8 {
 namespace internal {
@@ -137,7 +141,7 @@ void ImplementationVisitor::Visit(NamespaceConstant* decl) {
 
   assembler_ = base::nullopt;
 
-  source_out() << "return ";
+  source_out() << "  return ";
   CSAGenerator::EmitCSAValue(return_result, values, source_out());
   source_out() << ";\n";
   source_out() << "}\n\n";
@@ -433,8 +437,9 @@ void ImplementationVisitor::Visit(Builtin* builtin) {
 
       source_out()
           << "  Node* argc = Parameter(Descriptor::kJSActualArgumentsCount);\n";
-      source_out()
-          << "  TNode<IntPtrT> arguments_length(ChangeInt32ToIntPtr(argc));\n";
+      source_out() << "  TNode<IntPtrT> "
+                      "arguments_length(ChangeInt32ToIntPtr(UncheckedCast<"
+                      "Int32T>(argc)));\n";
       source_out() << "  TNode<RawPtrT> arguments_frame = "
                       "UncheckedCast<RawPtrT>(LoadFramePointer());\n";
       source_out() << "  TorqueStructArguments "
@@ -1281,17 +1286,16 @@ LocationReference ImplementationVisitor::GenerateFieldReference(
     result_range.Extend(length.stack_range());
     const Type* slice_type = TypeOracle::GetSliceType(field.name_and_type.type);
     return LocationReference::HeapSlice(VisitResult(slice_type, result_range));
-
   } else {
-    VisitResult heap_reference(
-        TypeOracle::GetReferenceType(field.name_and_type.type), result_range);
-    return LocationReference::HeapReference(heap_reference);
+    const Type* type = TypeOracle::GetReferenceType(field.name_and_type.type,
+                                                    field.const_qualified);
+    return LocationReference::HeapReference(VisitResult(type, result_range));
   }
 }
 
 // This is used to generate field references during initialization, where we can
 // re-use the offsets used for computing the allocation size.
-LocationReference ImplementationVisitor::GenerateFieldReference(
+LocationReference ImplementationVisitor::GenerateFieldReferenceForInit(
     VisitResult object, const Field& field,
     const LayoutForInitialization& layout) {
   StackRange result_range = assembler().TopRange(0);
@@ -1306,8 +1310,10 @@ LocationReference ImplementationVisitor::GenerateFieldReference(
     const Type* slice_type = TypeOracle::GetSliceType(field.name_and_type.type);
     return LocationReference::HeapSlice(VisitResult(slice_type, result_range));
   } else {
+    // Const fields are writable during initialization.
     VisitResult heap_reference(
-        TypeOracle::GetReferenceType(field.name_and_type.type), result_range);
+        TypeOracle::GetMutableReferenceType(field.name_and_type.type),
+        result_range);
     return LocationReference::HeapReference(heap_reference);
   }
 }
@@ -1324,7 +1330,7 @@ void ImplementationVisitor::InitializeClass(
     VisitResult initializer_value =
         initializer_results.field_value_map.at(f.name_and_type.name);
     LocationReference field =
-        GenerateFieldReference(allocate_result, f, layout);
+        GenerateFieldReferenceForInit(allocate_result, f, layout);
     if (f.index) {
       DCHECK(field.IsHeapSlice());
       VisitResult slice = field.GetVisitResult();
@@ -1339,7 +1345,7 @@ void ImplementationVisitor::InitializeClass(
 
 VisitResult ImplementationVisitor::GenerateArrayLength(
     Expression* array_length, Namespace* nspace,
-    const std::map<std::string, LocationReference>& bindings) {
+    const std::map<std::string, LocalValue>& bindings) {
   StackScope stack_scope(this);
   CurrentSourcePosition::Scope pos_scope(array_length->pos);
   // Switch to the namespace where the class was declared.
@@ -1363,11 +1369,15 @@ VisitResult ImplementationVisitor::GenerateArrayLength(VisitResult object,
 
   StackScope stack_scope(this);
   const ClassType* class_type = *object.type()->ClassSupertype();
-  std::map<std::string, LocationReference> bindings;
+  std::map<std::string, LocalValue> bindings;
   for (Field f : class_type->ComputeAllFields()) {
     if (f.index) break;
     bindings.insert(
-        {f.name_and_type.name, GenerateFieldReference(object, f, class_type)});
+        {f.name_and_type.name,
+         f.const_qualified
+             ? LocalValue{GenerateFieldReference(object, f, class_type)}
+             : LocalValue(
+                   "Non-const fields cannot be used for array lengths.")});
   }
   return stack_scope.Yield(
       GenerateArrayLength(*field.index, class_type->nspace(), bindings));
@@ -1379,13 +1389,18 @@ VisitResult ImplementationVisitor::GenerateArrayLength(
   DCHECK(field.index);
 
   StackScope stack_scope(this);
-  std::map<std::string, LocationReference> bindings;
+  std::map<std::string, LocalValue> bindings;
   for (Field f : class_type->ComputeAllFields()) {
     if (f.index) break;
     const std::string& fieldname = f.name_and_type.name;
     VisitResult value = initializer_results.field_value_map.at(fieldname);
-    bindings.insert({fieldname, LocationReference::Temporary(
-                                    value, "initial field " + fieldname)});
+    bindings.insert(
+        {fieldname,
+         f.const_qualified
+             ? LocalValue{LocationReference::Temporary(
+                   value, "initial field " + fieldname)}
+             : LocalValue(
+                   "Non-const fields cannot be used for array lengths.")});
   }
   return stack_scope.Yield(
       GenerateArrayLength(*field.index, class_type->nspace(), bindings));
@@ -1481,7 +1496,7 @@ VisitResult ImplementationVisitor::Visit(NewExpression* expr) {
         VisitResult(TypeOracle::GetConstexprInstanceTypeType(),
                     CapifyStringWithUnderscores(class_type->name()) + "_TYPE"));
     object_map = GenerateCall(
-        QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING}, "GetStructMap"),
+        QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING}, "GetInstanceTypeMap"),
         get_struct_map_arguments, {}, false);
     CurrentSourcePosition::Scope current_pos(expr->pos);
     initializer_results.names.insert(initializer_results.names.begin(),
@@ -1653,7 +1668,7 @@ std::vector<std::string> ImplementationVisitor::GenerateFunctionDeclaration(
     size_t i = 0;
     for (const Type* type : label_info.types) {
       std::string generated_type_name;
-      if (type->IsStructType()) {
+      if (type->StructSupertype()) {
         generated_type_name = "\n#error no structs allowed in labels\n";
       } else {
         generated_type_name = "compiler::TypedCodeAssemblerVariable<";
@@ -1948,15 +1963,15 @@ LocationReference ImplementationVisitor::GetLocationReference(
 LocationReference ImplementationVisitor::GetLocationReference(
     FieldAccessExpression* expr) {
   return GenerateFieldAccess(GetLocationReference(expr->object),
-                             expr->field->value, expr->field->pos);
+                             expr->field->value, false, expr->field->pos);
 }
 
 LocationReference ImplementationVisitor::GenerateFieldAccess(
     LocationReference reference, const std::string& fieldname,
-    base::Optional<SourcePosition> pos) {
+    bool ignore_stuct_field_constness, base::Optional<SourcePosition> pos) {
   if (reference.IsVariableAccess() &&
-      reference.variable().type()->IsStructType()) {
-    const StructType* type = StructType::cast(reference.variable().type());
+      reference.variable().type()->StructSupertype()) {
+    const StructType* type = *reference.variable().type()->StructSupertype();
     const Field& field = type->LookupField(fieldname);
     if (GlobalContext::collect_language_server_data() && pos.has_value()) {
       LanguageServerData::AddDefinition(*pos, field.pos);
@@ -1970,9 +1985,10 @@ LocationReference ImplementationVisitor::GenerateFieldAccess(
           ProjectStructField(reference.variable(), fieldname));
     }
   }
-  if (reference.IsTemporary() && reference.temporary().type()->IsStructType()) {
+  if (reference.IsTemporary() &&
+      reference.temporary().type()->StructSupertype()) {
     if (GlobalContext::collect_language_server_data() && pos.has_value()) {
-      const StructType* type = StructType::cast(reference.temporary().type());
+      const StructType* type = *reference.temporary().type()->StructSupertype();
       const Field& field = type->LookupField(fieldname);
       LanguageServerData::AddDefinition(*pos, field.pos);
     }
@@ -1988,20 +2004,23 @@ LocationReference ImplementationVisitor::GenerateFieldAccess(
   }
   if (reference.IsHeapReference()) {
     VisitResult ref = reference.heap_reference();
-    auto generic_type = StructType::MatchUnaryGeneric(
-        ref.type(), TypeOracle::GetReferenceGeneric());
+    bool is_const;
+    auto generic_type =
+        TypeOracle::MatchReferenceGeneric(ref.type(), &is_const);
     if (!generic_type) {
       ReportError(
           "Left-hand side of field access expression is marked as a reference "
           "but is not of type Reference<...>. Found type: ",
           ref.type()->ToString());
     }
-    if (const StructType* struct_type =
-            StructType::DynamicCast(*generic_type)) {
-      const Field& field = struct_type->LookupField(fieldname);
+    if (auto struct_type = (*generic_type)->StructSupertype()) {
+      const Field& field = (*struct_type)->LookupField(fieldname);
       // Update the Reference's type to refer to the field type within the
       // struct.
-      ref.SetType(TypeOracle::GetReferenceType(field.name_and_type.type));
+      ref.SetType(TypeOracle::GetReferenceType(
+          field.name_and_type.type,
+          is_const ||
+              (field.const_qualified && !ignore_stuct_field_constness)));
       if (!field.offset.has_value()) {
         Error("accessing field with unknown offset").Throw();
       }
@@ -2075,12 +2094,7 @@ LocationReference ImplementationVisitor::GetLocationReference(
         ReportError("cannot have generic parameters on local name ",
                     expr->name);
       }
-      const LocationReference& ref = (*value)->value;
-      if (ref.IsVariableAccess()) {
-        // Attach the binding to enable the never-assigned-to lint check.
-        return LocationReference::VariableAccess(ref.GetVisitResult(), *value);
-      }
-      return ref;
+      return (*value)->GetLocationReference(*value);
     }
   }
 
@@ -2136,9 +2150,10 @@ LocationReference ImplementationVisitor::GetLocationReference(
 LocationReference ImplementationVisitor::GetLocationReference(
     DereferenceExpression* expr) {
   VisitResult ref = Visit(expr->reference);
-  if (!Type::MatchUnaryGeneric(ref.type(), TypeOracle::GetReferenceGeneric())) {
-    ReportError("Operator * expects a reference but found a value of type ",
-                *ref.type());
+  if (!TypeOracle::MatchReferenceGeneric(ref.type())) {
+    Error("Operator * expects a reference type but found a value of type ",
+          *ref.type())
+        .Throw();
   }
   return LocationReference::HeapReference(ref);
 }
@@ -2155,9 +2170,9 @@ VisitResult ImplementationVisitor::GenerateFetchFromLocation(
       return GenerateCall(QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING},
                                         "LoadFloat64OrHole"),
                           Arguments{{reference.heap_reference()}, {}});
-    } else if (auto* struct_type = StructType::DynamicCast(referenced_type)) {
+    } else if (auto struct_type = referenced_type->StructSupertype()) {
       StackRange result_range = assembler().TopRange(0);
-      for (const Field& field : struct_type->fields()) {
+      for (const Field& field : (*struct_type)->fields()) {
         StackScope scope(this);
         const std::string& fieldname = field.name_and_type.name;
         VisitResult field_value = scope.Yield(GenerateFetchFromLocation(
@@ -2212,20 +2227,27 @@ void ImplementationVisitor::GenerateAssignToLocation(
     ReportError("assigning a value directly to an indexed field isn't allowed");
   } else if (reference.IsHeapReference()) {
     const Type* referenced_type = reference.ReferencedType();
+    if (reference.IsConst()) {
+      Error("cannot assign to const value of type ", *referenced_type).Throw();
+    }
     if (referenced_type == TypeOracle::GetFloat64OrHoleType()) {
       GenerateCall(
           QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING},
                         "StoreFloat64OrHole"),
           Arguments{{reference.heap_reference(), assignment_value}, {}});
-    } else if (auto* struct_type = StructType::DynamicCast(referenced_type)) {
-      if (assignment_value.type() != referenced_type) {
+    } else if (auto struct_type = referenced_type->StructSupertype()) {
+      if (!assignment_value.type()->IsSubtypeOf(referenced_type)) {
         ReportError("Cannot assign to ", *referenced_type,
                     " with value of type ", *assignment_value.type());
       }
-      for (const Field& field : struct_type->fields()) {
+      for (const Field& field : (*struct_type)->fields()) {
         const std::string& fieldname = field.name_and_type.name;
+        // Allow assignment of structs even if they contain const fields.
+        // Const on struct fields just disallows direct writes to them.
+        bool ignore_stuct_field_constness = true;
         GenerateAssignToLocation(
-            GenerateFieldAccess(reference, fieldname),
+            GenerateFieldAccess(reference, fieldname,
+                                ignore_stuct_field_constness),
             ProjectStructField(assignment_value, fieldname));
       }
     } else {
@@ -2358,7 +2380,8 @@ VisitResult ImplementationVisitor::GenerateCall(
                   "' required for call to '", callable->ReadableName(),
                   "' is not defined");
     }
-    implicit_arguments.push_back(GenerateFetchFromLocation((*val)->value));
+    implicit_arguments.push_back(
+        GenerateFetchFromLocation((*val)->GetLocationReference(*val)));
   }
 
   std::vector<VisitResult> converted_arguments;
@@ -2758,9 +2781,9 @@ std::vector<Binding<LocalLabel>*> ImplementationVisitor::LabelsFromIdentifiers(
 StackRange ImplementationVisitor::LowerParameter(
     const Type* type, const std::string& parameter_name,
     Stack<std::string>* lowered_parameters) {
-  if (const StructType* struct_type = StructType::DynamicCast(type)) {
+  if (base::Optional<const StructType*> struct_type = type->StructSupertype()) {
     StackRange range = lowered_parameters->TopRange(0);
-    for (auto& field : struct_type->fields()) {
+    for (auto& field : (*struct_type)->fields()) {
       StackRange parameter_range = LowerParameter(
           field.name_and_type.type,
           parameter_name + "." + field.name_and_type.name, lowered_parameters);
@@ -2776,8 +2799,8 @@ StackRange ImplementationVisitor::LowerParameter(
 void ImplementationVisitor::LowerLabelParameter(
     const Type* type, const std::string& parameter_name,
     std::vector<std::string>* lowered_parameters) {
-  if (const StructType* struct_type = StructType::DynamicCast(type)) {
-    for (auto& field : struct_type->fields()) {
+  if (base::Optional<const StructType*> struct_type = type->StructSupertype()) {
+    for (auto& field : (*struct_type)->fields()) {
       LowerLabelParameter(
           field.name_and_type.type,
           "&((*" + parameter_name + ")." + field.name_and_type.name + ")",
@@ -2969,8 +2992,7 @@ void ImplementationVisitor::GenerateBuiltinDefinitionsAndInterfaceDescriptors(
       } else {
         builtin_definitions << "TFJ(" << builtin->ExternalName();
         if (builtin->IsVarArgsJavaScript()) {
-          builtin_definitions
-              << ", SharedFunctionInfo::kDontAdaptArgumentsSentinel";
+          builtin_definitions << ", kDontAdaptArgumentsSentinel";
         } else {
           DCHECK(builtin->IsFixedArgsJavaScript());
           // FixedArg javascript builtins need to offer the parameter
@@ -3061,9 +3083,9 @@ class FieldOffsetsGenerator {
     UpdateSection(f);
 
     // Emit kHeaderSize before any indexed field.
-    // TODO(tebbi): Generalize this code to work with multiple indexed fields.
-    if (f.index.has_value()) {
+    if (f.index.has_value() && !header_size_emitted_) {
       WriteMarker("kHeaderSize");
+      header_size_emitted_ = true;
     }
 
     // We don't know statically how much space an indexed field takes, so report
@@ -3103,14 +3125,28 @@ class FieldOffsetsGenerator {
 
  private:
   FieldSectionType GetSectionFor(const Field& f) {
-    if (f.name_and_type.type == TypeOracle::GetVoidType()) {
+    const Type* field_type = f.name_and_type.type;
+    if (field_type == TypeOracle::GetVoidType()) {
       // Allow void type for marker constants of size zero.
       return current_section_;
     }
+    StructType::Classification struct_contents =
+        StructType::ClassificationFlag::kEmpty;
+    if (auto field_as_struct = field_type->StructSupertype()) {
+      struct_contents = (*field_as_struct)->ClassifyContents();
+    }
+    if (struct_contents == StructType::ClassificationFlag::kMixed) {
+      // We can't declare what section a struct goes in if it has multiple
+      // categories of data within.
+      Error(
+          "Classes do not support fields which are structs containing both "
+          "tagged and untagged data.")
+          .Position(f.pos);
+    }
     // Currently struct-valued fields are only allowed to have tagged data; see
     // TypeVisitor::VisitClassFieldsAndMethods.
-    if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetTaggedType()) ||
-        f.name_and_type.type->IsStructType()) {
+    if (field_type->IsSubtypeOf(TypeOracle::GetTaggedType()) ||
+        struct_contents == StructType::ClassificationFlag::kTagged) {
       if (f.is_weak) {
         return FieldSectionType::kWeakSection;
       } else {
@@ -3150,6 +3186,7 @@ class FieldOffsetsGenerator {
   FieldSectionType current_section_ = FieldSectionType::kNoSection;
   FieldSections completed_sections_ = FieldSectionType::kNoSection;
   bool is_finished_ = false;
+  bool header_size_emitted_ = false;
 };
 
 class MacroFieldOffsetsGenerator : public FieldOffsetsGenerator {
@@ -3172,48 +3209,23 @@ class MacroFieldOffsetsGenerator : public FieldOffsetsGenerator {
   std::ostream& out_;
 };
 
-}  // namespace
-
-void ImplementationVisitor::GenerateCppForInternalClasses(
-    const std::string& output_directory) {
-  std::stringstream header;
-  std::stringstream inl;
-  std::string base_name = "internal-class-definitions-tq";
-  {
-    IncludeGuardScope header_guard(header, base_name + ".h");
-    header << "#include \"src/objects/objects.h\"\n";
-    header << "#include \"src/objects/struct.h\"\n";
-    header << "#include \"src/objects/js-objects.h\"\n";
-    header << "#include \"src/utils/utils.h\"\n";
-    header << "#include \"torque-generated/class-definitions-tq.h\"\n";
-    IncludeObjectMacrosScope header_macros(header);
-    NamespaceScope header_namespaces(header, {"v8", "internal"});
-
-    IncludeGuardScope inl_guard(inl, base_name + "-inl.h");
-    inl << "#include \"torque-generated/" << base_name << ".h\"\n";
-    inl << "#include \"torque-generated/class-definitions-tq-inl.h\"\n";
-    IncludeObjectMacrosScope inl_macros(inl);
-    NamespaceScope inl_namespaces(inl, {"v8", "internal"});
-
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
-      if (type->IsExtern()) continue;
-      const ClassType* super = type->GetSuperClass();
-      std::string parent = "TorqueGenerated" + type->name() + "<" +
-                           type->name() + ", " + super->name() + ">";
-      header << "class " << type->name() << ": public " << parent << " {\n";
-      header << " public:\n";
-      header << "   TQ_OBJECT_CONSTRUCTORS(" << type->name() << ")\n";
-      header << "};\n\n";
-
-      inl << "TQ_OBJECT_CONSTRUCTORS_IMPL(" << type->name() << ")\n";
-    }
-  }
-  std::string dir_basename = output_directory + "/" + base_name;
-  WriteFile(dir_basename + ".h", header.str());
-  WriteFile(dir_basename + "-inl.h", inl.str());
+void GenerateClassExport(const ClassType* type, std::ostream& header,
+                         std::ostream& inl_header) {
+  const ClassType* super = type->GetSuperClass();
+  std::string parent = "TorqueGenerated" + type->name() + "<" + type->name() +
+                       ", " + super->name() + ">";
+  header << "class " << type->name() << " : public " << parent << " {\n";
+  header << " public:\n";
+  if (type->ShouldGenerateBodyDescriptor()) {
+    header << "  class BodyDescriptor;\n";
+  }
+  header << "  TQ_OBJECT_CONSTRUCTORS(" << type->name() << ")\n";
+  header << "};\n\n";
+  inl_header << "TQ_OBJECT_CONSTRUCTORS_IMPL(" << type->name() << ")\n";
 }
 
+}  // namespace
+
 void ImplementationVisitor::GenerateClassFieldOffsets(
     const std::string& output_directory) {
   std::stringstream header;
@@ -3221,9 +3233,7 @@ void ImplementationVisitor::GenerateClassFieldOffsets(
   {
     IncludeGuardScope include_guard(header, file_name);
 
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
-
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       // TODO(danno): Remove this once all classes use ClassFieldOffsetGenerator
       // to generate field offsets without the use of macros.
       if (!type->GenerateCppClassDefinitions() && !type->HasUndefinedLayout()) {
@@ -3236,6 +3246,16 @@ void ImplementationVisitor::GenerateClassFieldOffsets(
         header << "\n";
       }
     }
+
+    header << "#define TORQUE_BODY_DESCRIPTOR_LIST_GENERATOR(V, _)\\\n";
+    for (const ClassType* type : TypeOracle::GetClasses()) {
+      if (type->ShouldGenerateBodyDescriptor()) {
+        std::string type_name =
+            CapifyStringWithUnderscores(type->name()) + "_TYPE";
+        header << "V(_, " << type_name << ", " << type->name() << ")\\\n";
+      }
+    }
+    header << "\n";
   }
   const std::string output_header_path = output_directory + "/" + file_name;
   WriteFile(output_header_path, header.str());
@@ -3250,29 +3270,35 @@ void ImplementationVisitor::GenerateBitFields(
     header << "#include \"src/base/bit-field.h\"\n\n";
     NamespaceScope namespaces(header, {"v8", "internal"});
 
-    // TODO(v8:7793): Once we can define enums in Torque, we should be able to
-    // do something nicer than hard-coding these predeclarations. Until then,
-    // any enum used as a bitfield must be included in this list.
-    header << R"(
-enum class FunctionSyntaxKind : uint8_t;
-enum class BailoutReason : uint8_t;
-enum FunctionKind : uint8_t;
-
-)";
-
     for (const auto& type : TypeOracle::GetBitFieldStructTypes()) {
-      header << "struct TorqueGenerated" << type->name() << "Fields {\n";
+      bool all_single_bits = true;  // Track whether every field is one bit.
+
+      header << "#define DEFINE_TORQUE_GENERATED_"
+             << CapifyStringWithUnderscores(type->name()) << "() \\\n";
       std::string type_name = type->GetConstexprGeneratedTypeName();
       for (const auto& field : type->fields()) {
         const char* suffix = field.num_bits == 1 ? "Bit" : "Bits";
+        all_single_bits = all_single_bits && field.num_bits == 1;
         std::string field_type_name =
             field.name_and_type.type->GetConstexprGeneratedTypeName();
         header << "  using " << CamelifyString(field.name_and_type.name)
                << suffix << " = base::BitField<" << field_type_name << ", "
                << field.offset << ", " << field.num_bits << ", " << type_name
-               << ">;\n";
+               << ">; \\\n";
+      }
+
+      // If every field is one bit, we can also generate a convenient enum.
+      if (all_single_bits) {
+        header << "  enum Flag { \\\n";
+        header << "    kNone = 0, \\\n";
+        for (const auto& field : type->fields()) {
+          header << "    k" << CamelifyString(field.name_and_type.name)
+                 << " = 1 << " << field.offset << ", \\\n";
+        }
+        header << "  }; \\\n";
       }
-      header << "};\n\n";
+
+      header << "\n";
     }
   }
   const std::string output_header_path = output_directory + "/" + file_name;
@@ -3345,6 +3371,29 @@ class CppClassGenerator {
   std::ostream& impl_;
 };
 
+base::Optional<std::vector<Field>> GetOrderedUniqueIndexFields(
+    const ClassType& type) {
+  std::vector<Field> result;
+  std::set<std::string> index_names;
+  for (const Field& field : type.ComputeAllFields()) {
+    if (field.index) {
+      auto name_and_type = ExtractSimpleFieldArraySize(type, *field.index);
+      if (!name_and_type) {
+        return base::nullopt;
+      }
+      index_names.insert(name_and_type->name);
+    }
+  }
+
+  for (const Field& field : type.ComputeAllFields()) {
+    if (index_names.count(field.name_and_type.name) != 0) {
+      result.push_back(field);
+    }
+  }
+
+  return result;
+}
+
 void CppClassGenerator::GenerateClass() {
   hdr_ << template_decl() << "\n";
   hdr_ << "class " << gen_name_ << " : public P {\n";
@@ -3354,10 +3403,16 @@ void CppClassGenerator::GenerateClass() {
        << "    \"Pass in " << super_->name()
        << " as second template parameter for " << gen_name_ << ".\");\n";
   hdr_ << " public: \n";
-  hdr_ << "  using Super = P;\n";
+  hdr_ << "  using Super = P;\n\n";
+  if (!type_->ShouldExport() && !type_->IsExtern()) {
+    hdr_ << " protected: // not extern or @export\n";
+  }
   for (const Field& f : type_->fields()) {
     GenerateFieldAccessor(f);
   }
+  if (!type_->ShouldExport() && !type_->IsExtern()) {
+    hdr_ << " public:\n";
+  }
 
   GenerateClassCasts();
 
@@ -3389,9 +3444,70 @@ void CppClassGenerator::GenerateClass() {
   g.Finish();
   hdr_ << "\n";
 
+  auto index_fields = GetOrderedUniqueIndexFields(*type_);
+
+  if (!index_fields.has_value()) {
+    hdr_ << "  // SizeFor implementations not generated due to complex array "
+            "lengths\n\n";
+  } else if (!type_->IsAbstract() &&
+             !type_->IsSubtypeOf(TypeOracle::GetJSObjectType())) {
+    hdr_ << "  V8_INLINE static constexpr int32_t SizeFor(";
+    bool first = true;
+    for (const Field& field : *index_fields) {
+      if (!first) hdr_ << ", ";
+      hdr_ << "int " << field.name_and_type.name;
+      first = false;
+    }
+    hdr_ << ") {\n";
+    if (index_fields->empty()) {
+      hdr_ << "    DCHECK(kHeaderSize == kSize && kHeaderSize == "
+           << *type_->size().SingleValue() << ");\n";
+    }
+    hdr_ << "    int32_t size = kHeaderSize;\n";
+    for (const Field& field : type_->ComputeAllFields()) {
+      if (field.index) {
+        auto index_name_and_type =
+            *ExtractSimpleFieldArraySize(*type_, *field.index);
+        size_t field_size = 0;
+        std::tie(field_size, std::ignore) = field.GetFieldSizeInformation();
+        hdr_ << "    size += " << index_name_and_type.name << " * "
+             << field_size << ";\n";
+      }
+    }
+    hdr_ << "    return size;\n";
+    hdr_ << "  }\n\n";
+    hdr_ << "  V8_INLINE static constexpr int32_t SizeFor(D o) {\n";
+    hdr_ << "    return SizeFor(";
+    first = true;
+    for (auto field : *index_fields) {
+      if (!first) hdr_ << ", ";
+      // Subclasses of FixedArrayBase need to use the synchronized length
+      // accessor to be consistent (theoretically, FixedArrayBase classes
+      // can concurrently change size e.g. through left-trimming, although
+      // in practice this won't happen for Torque-generated classes) as well as
+      // explicitly convert to a Smi, since the C++-side accessors are
+      // int-based.
+      if (field.aggregate == TypeOracle::GetFixedArrayBaseType() &&
+          field.name_and_type.name == "length") {
+        hdr_ << "o.synchronized_length()";
+      } else {
+        hdr_ << "o." << field.name_and_type.name << "()";
+      }
+      first = false;
+    }
+    hdr_ << ");\n  }\n";
+    hdr_ << "\n";
+  }
+
+  hdr_ << "  friend class Factory;\n\n";
+
   GenerateClassConstructors();
 
   hdr_ << "};\n\n";
+
+  if (!type_->IsExtern()) {
+    GenerateClassExport(type_, hdr_, inl_);
+  }
 }
 
 void CppClassGenerator::GenerateClassCasts() {
@@ -3427,7 +3543,11 @@ void CppClassGenerator::GenerateClassConstructors() {
 // TODO(sigurds): Keep in sync with DECL_ACCESSORS and ACCESSORS macro.
 void CppClassGenerator::GenerateFieldAccessor(const Field& f) {
   const Type* field_type = f.name_and_type.type;
-  if (field_type == TypeOracle::GetVoidType() || f.index.has_value()) return;
+  if (field_type == TypeOracle::GetVoidType()) return;
+
+  // TODO(danno): Support generation of struct accessors
+  if (f.name_and_type.type->IsStructType()) return;
+
   if (!f.name_and_type.type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
     return GenerateFieldAccessorForUntagged(f);
   }
@@ -3439,7 +3559,8 @@ void CppClassGenerator::GenerateFieldAccessor(const Field& f) {
   }
 
   Error("Generation of field accessor for ", type_->name(),
-        ":: ", f.name_and_type.name, " : ", *field_type, " is not supported.")
+        "::", f.name_and_type.name, " failed (type ", *field_type,
+        " is not supported).")
       .Position(f.pos);
 }
 
@@ -3458,48 +3579,101 @@ void CppClassGenerator::GenerateFieldAccessorForUntagged(const Field& f) {
   }
   const std::string& name = f.name_and_type.name;
   const std::string type = constexpr_version->GetGeneratedTypeName();
-  const std::string offset = "k" + CamelifyString(name) + "Offset";
+  std::string offset = "k" + CamelifyString(name) + "Offset";
 
   // Generate declarations in header.
-  hdr_ << "  inline " << type << " " << name << "() const;\n";
-  hdr_ << "  inline void set_" << name << "(" << type << " value);\n\n";
+  if (f.index) {
+    hdr_ << "  inline " << type << " " << name << "(int i) const;\n";
+    hdr_ << "  inline void set_" << name << "(int i, " << type
+         << " value);\n\n";
+  } else {
+    hdr_ << "  inline " << type << " " << name << "() const;\n";
+    hdr_ << "  inline void set_" << name << "(" << type << " value);\n\n";
+  }
 
   // Generate implementation in inline header.
   inl_ << "template <class D, class P>\n";
-  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "() const {\n";
-  inl_ << "  return this->template ReadField<" << type << ">(" << offset
-       << ");\n";
+  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "(";
+  if (f.index) {
+    inl_ << "int i";
+  }
+  inl_ << ") const {\n";
+  if (f.index) {
+    size_t field_size;
+    std::string size_string;
+    std::tie(field_size, size_string) = f.GetFieldSizeInformation();
+    inl_ << "  int offset = " << offset << " + i * " << field_size << ";\n";
+    inl_ << "  return this->template ReadField<" << type << ">(offset);\n";
+  } else {
+    inl_ << "  return this->template ReadField<" << type << ">(" << offset
+         << ");\n";
+  }
   inl_ << "}\n";
 
   inl_ << "template <class D, class P>\n";
-  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(" << type
-       << " value) {\n";
-  inl_ << "  this->template WriteField<" << type << ">(" << offset
-       << ", value);\n";
+  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(";
+  if (f.index) {
+    inl_ << "int i, ";
+  }
+  inl_ << type << " value) {\n";
+  if (f.index) {
+    size_t field_size;
+    std::string size_string;
+    std::tie(field_size, size_string) = f.GetFieldSizeInformation();
+    inl_ << "  int offset = " << offset << " + i * " << field_size << ";\n";
+    inl_ << "  this->template WriteField<" << type << ">(offset, value);\n";
+  } else {
+    inl_ << "  this->template WriteField<" << type << ">(" << offset
+         << ", value);\n";
+  }
   inl_ << "}\n\n";
 }
 
 void CppClassGenerator::GenerateFieldAccessorForSmi(const Field& f) {
   DCHECK(f.name_and_type.type->IsSubtypeOf(TypeOracle::GetSmiType()));
-  const std::string type = "Smi";
+  // Follow the convention to create Smi accessors with type int.
+  const std::string type = "int";
   const std::string& name = f.name_and_type.name;
   const std::string offset = "k" + CamelifyString(name) + "Offset";
 
   // Generate declarations in header.
+  if (f.index) {
+    hdr_ << "  inline " << type << " " << name << "(int i) const;\n";
+    hdr_ << "  inline void set_" << name << "(int i, " << type
+         << " value);\n\n";
+  }
   hdr_ << "  inline " << type << " " << name << "() const;\n";
   hdr_ << "  inline void set_" << name << "(" << type << " value);\n\n";
 
   // Generate implementation in inline header.
   inl_ << "template <class D, class P>\n";
-  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "() const {\n";
-  inl_ << "  return TaggedField<Smi, " << offset << ">::load(*this);\n";
-  inl_ << "}\n";
+  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "(";
+  if (f.index) {
+    inl_ << "int i";
+  }
+  inl_ << ") const {\n";
+  if (f.index) {
+    inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
+    inl_ << "  return this->template ReadField<Smi>(offset).value();\n";
+    inl_ << "}\n";
+  } else {
+    inl_ << "  return TaggedField<Smi, " << offset
+         << ">::load(*this).value();\n";
+    inl_ << "}\n";
+  }
 
   inl_ << "template <class D, class P>\n";
-  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(" << type
-       << " value) {\n";
-  inl_ << "  DCHECK(value.IsSmi());\n";
-  inl_ << "  WRITE_FIELD(*this, " << offset << ", value);\n";
+  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(";
+  if (f.index) {
+    inl_ << "int i, ";
+  }
+  inl_ << type << " value) {\n";
+  if (f.index) {
+    inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
+    inl_ << "  WRITE_FIELD(*this, offset, Smi::FromInt(value));\n";
+  } else {
+    inl_ << "  WRITE_FIELD(*this, " << offset << ", Smi::FromInt(value));\n";
+  }
   inl_ << "}\n\n";
 }
 
@@ -3517,11 +3691,13 @@ void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
   if (!class_type && field_type != TypeOracle::GetObjectType()) {
     hdr_ << "  // Torque type: " << field_type->ToString() << "\n";
   }
-  hdr_ << "  inline " << type << " " << name << "() const;\n";
-  hdr_ << "  inline " << type << " " << name
-       << "(const Isolate* isolate) const;\n";
-  hdr_ << "  inline void set_" << name << "(" << type
-       << " value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);\n\n";
+
+  hdr_ << "  inline " << type << " " << name << "(" << (f.index ? "int i" : "")
+       << ") const;\n";
+  hdr_ << "  inline " << type << " " << name << "(const Isolate* isolates"
+       << (f.index ? ", int i" : "") << ") const;\n";
+  hdr_ << "  inline void set_" << name << "(" << (f.index ? "int i, " : "")
+       << type << " value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);\n\n";
 
   std::string type_check;
   for (const RuntimeType& runtime_type : field_type->GetRuntimeTypes()) {
@@ -3531,66 +3707,170 @@ void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
 
   // Generate implementation in inline header.
   inl_ << "template <class D, class P>\n";
-  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "() const {\n";
+  inl_ << type << " " << gen_name_ << "<D, P>::" << name << "("
+       << (f.index ? "int i" : "") << ") const {\n";
   inl_ << "  const Isolate* isolate = GetIsolateForPtrCompr(*this);\n";
-  inl_ << "  return " << gen_name_ << "::" << name << "(isolate);\n";
+  inl_ << "  return " << gen_name_ << "::" << name << "(isolate"
+       << (f.index ? ", i" : "") << ");\n";
   inl_ << "}\n";
 
   inl_ << "template <class D, class P>\n";
   inl_ << type << " " << gen_name_ << "<D, P>::" << name
-       << "(const Isolate* isolate) const {\n";
+       << "(const Isolate* isolate" << (f.index ? ", int i" : "")
+       << ") const {\n";
+
   if (class_type) {
-    inl_ << "  return TaggedField<" << type << ", " << offset
-         << ">::load(isolate, *this);\n";
+    if (f.index) {
+      inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
+      inl_ << "  return " << type
+           << "::cast(RELAXED_READ_FIELD(*this, offset));\n";
+    } else {
+      inl_ << "  return TaggedField<" << type << ", " << offset
+           << ">::load(isolate, *this);\n";
+    }
   } else {
     // TODO(tebbi): load value as HeapObject when possible
-    inl_ << "  Object value = TaggedField<Object, " << offset
-         << ">::load(isolate, *this);\n";
+    if (f.index) {
+      inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
+      inl_ << "  Object value = Object::cast(RELAXED_READ_FIELD(*this, "
+              "offset));\n";
+    } else {
+      inl_ << "  Object value = TaggedField<Object, " << offset
+           << ">::load(isolate, *this);\n";
+    }
     inl_ << "  DCHECK(" << type_check << ");\n";
     inl_ << "  return value;\n";
   }
   inl_ << "}\n";
 
   inl_ << "template <class D, class P>\n";
-  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(" << type
-       << " value, WriteBarrierMode mode) {\n";
+  inl_ << "void " << gen_name_ << "<D, P>::set_" << name << "(";
+  if (f.index) {
+    inl_ << "int i, ";
+  }
+  inl_ << type << " value, WriteBarrierMode mode) {\n";
   inl_ << "  SLOW_DCHECK(" << type_check << ");\n";
-  inl_ << "  WRITE_FIELD(*this, " << offset << ", value);\n";
+  if (f.index) {
+    inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
+    inl_ << "  WRITE_FIELD(*this, offset, value);\n";
+  } else {
+    inl_ << "  WRITE_FIELD(*this, " << offset << ", value);\n";
+  }
   inl_ << "  CONDITIONAL_WRITE_BARRIER(*this, " << offset
        << ", value, mode);\n";
   inl_ << "}\n\n";
 }
 
+void EmitClassDefinitionHeadersIncludes(const std::string& basename,
+                                        std::stringstream& header,
+                                        std::stringstream& inline_header) {
+  header << "#include \"src/objects/fixed-array.h\"\n";
+  header << "#include \"src/objects/objects.h\"\n";
+  header << "#include \"src/objects/smi.h\"\n";
+  header << "#include \"torque-generated/field-offsets-tq.h\"\n";
+  header << "#include <type_traits>\n\n";
+
+  inline_header << "#include \"torque-generated/class-definitions-tq.h\"\n";
+  inline_header << "#include "
+                   "\"torque-generated/objects-body-descriptors-tq-inl.h\"\n\n";
+  inline_header << "#include \"src/objects/js-promise.h\"\n";
+  inline_header << "#include \"src/objects/js-weak-refs.h\"\n";
+  inline_header << "#include \"src/objects/module.h\"\n";
+  inline_header << "#include \"src/objects/objects-inl.h\"\n";
+  inline_header << "#include \"src/objects/script.h\"\n";
+  inline_header << "#include \"src/objects/shared-function-info.h\"\n";
+  inline_header << "#include \"src/objects/tagged-field.h\"\n\n";
+}
+
+void EmitClassDefinitionHeadersForwardDeclarations(std::stringstream& header) {
+  // Generate forward declarations for every class.
+  for (const ClassType* type : TypeOracle::GetClasses()) {
+    header << "class " << type->GetGeneratedTNodeTypeName() << ";\n";
+  }
+  header << "using BuiltinPtr = Smi;\n\n";
+}
+
+void GenerateStructLayoutDescription(std::ostream& header,
+                                     const StructType* type) {
+  header << "struct TorqueGenerated" << CamelifyString(type->name())
+         << "Offsets {\n";
+  for (const Field& field : type->fields()) {
+    header << "  static constexpr int k"
+           << CamelifyString(field.name_and_type.name)
+           << "Offset = " << *field.offset << ";\n";
+  }
+  header << "  static constexpr int kSize = " << type->PackedSize() << ";\n";
+  header << "};\n\n";
+}
+
 }  // namespace
 
 void ImplementationVisitor::GenerateClassDefinitions(
     const std::string& output_directory) {
-  std::stringstream header;
-  std::stringstream inline_header;
+  std::stringstream external_header;
+  std::stringstream inline_external_header;
+  std::stringstream internal_header;
+  std::stringstream inline_internal_header;
   std::stringstream implementation;
+  std::stringstream factory_header;
+  std::stringstream factory_impl;
   std::string basename = "class-definitions-tq";
+  std::string internal_basename = "internal-" + basename;
   std::string file_basename = output_directory + "/" + basename;
+  std::string internal_file_basename =
+      output_directory + "/" + internal_basename;
+  std::string factory_basename = "factory-tq";
+  std::string factory_file_basename = output_directory + "/" + factory_basename;
 
   {
-    IncludeGuardScope header_guard(header, basename + ".h");
-    header << "#include \"src/objects/objects.h\"\n";
-    header << "#include \"src/objects/smi.h\"\n";
-    header << "#include \"torque-generated/field-offsets-tq.h\"\n";
-    header << "#include <type_traits>\n\n";
-    IncludeObjectMacrosScope header_macros(header);
-    NamespaceScope header_namespaces(header, {"v8", "internal"});
-    header << "using BuiltinPtr = Smi;\n\n";
-
-    IncludeGuardScope inline_header_guard(inline_header, basename + "-inl.h");
-    inline_header << "#include \"torque-generated/class-definitions-tq.h\"\n\n";
-    inline_header << "#include \"src/objects/js-promise.h\"\n";
-    inline_header << "#include \"src/objects/js-weak-refs.h\"\n";
-    inline_header << "#include \"src/objects/module.h\"\n";
-    inline_header << "#include \"src/objects/objects-inl.h\"\n";
-    inline_header << "#include \"src/objects/script.h\"\n";
-    inline_header << "#include \"src/objects/shared-function-info.h\"\n\n";
-    IncludeObjectMacrosScope inline_header_macros(inline_header);
-    NamespaceScope inline_header_namespaces(inline_header, {"v8", "internal"});
+    IncludeGuardScope header_guard(external_header, basename + ".h");
+
+    IncludeGuardScope inline_header_guard(inline_external_header,
+                                          basename + "-inl.h");
+
+    IncludeGuardScope internal_header_guard(internal_header,
+                                            internal_basename + ".h");
+
+    IncludeGuardScope internal_inline_header_guard(
+        inline_internal_header, internal_basename + "-inl.h");
+
+    external_header
+        << "#include \"torque-generated/internal-class-definitions-tq.h\"\n";
+
+    EmitClassDefinitionHeadersIncludes(basename, external_header,
+                                       inline_external_header);
+
+    EmitClassDefinitionHeadersIncludes(internal_basename, internal_header,
+                                       inline_internal_header);
+
+    IncludeObjectMacrosScope header_macros(external_header);
+    IncludeObjectMacrosScope inline_header_macros(inline_external_header);
+
+    IncludeObjectMacrosScope internal_header_macros(internal_header);
+    IncludeObjectMacrosScope internal_inline_header_macros(
+        inline_internal_header);
+
+    NamespaceScope header_namespaces(external_header, {"v8", "internal"});
+    NamespaceScope inline_header_namespaces(inline_external_header,
+                                            {"v8", "internal"});
+    NamespaceScope internal_header_namespaces(internal_header,
+                                              {"v8", "internal"});
+    NamespaceScope internal_inline_header_namespaces(inline_internal_header,
+                                                     {"v8", "internal"});
+
+    EmitClassDefinitionHeadersForwardDeclarations(external_header);
+    EmitClassDefinitionHeadersForwardDeclarations(internal_header);
+
+    factory_impl << "#include \"src/heap/factory.h\"\n";
+    factory_impl << "#include \"src/heap/factory-inl.h\"\n";
+    factory_impl << "#include \"src/heap/heap.h\"\n";
+    factory_impl << "#include \"src/heap/heap-inl.h\"\n";
+    factory_impl << "#include \"src/execution/isolate.h\"\n\n";
+    factory_impl
+        << "#include "
+           "\"torque-generated/internal-class-definitions-tq-inl.h\"\n\n";
+    NamespaceScope factory_impl_namespaces(factory_impl, {"v8", "internal"});
+    factory_impl << "\n";
 
     implementation
         << "#include \"torque-generated/class-definitions-tq.h\"\n\n";
@@ -3618,23 +3898,112 @@ void ImplementationVisitor::GenerateClassDefinitions(
     NamespaceScope implementation_namespaces(implementation,
                                              {"v8", "internal"});
 
-    // Generate forward declarations for every class.
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
-      header << "class " << type->GetGeneratedTNodeTypeName() << ";\n";
-    }
+    std::set<const StructType*, TypeLess> structs_used_in_classes;
+
+    for (const ClassType* type : TypeOracle::GetClasses()) {
+      std::stringstream& header = (type->IsExtern() || type->ShouldExport())
+                                      ? external_header
+                                      : internal_header;
+      std::stringstream& inline_header =
+          (type->IsExtern() || type->ShouldExport()) ? inline_external_header
+                                                     : inline_internal_header;
 
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
       if (type->GenerateCppClassDefinitions()) {
         CppClassGenerator g(type, header, inline_header, implementation);
         g.GenerateClass();
       }
+      for (const Field& f : type->fields()) {
+        const Type* field_type = f.name_and_type.type;
+        if (auto field_as_struct = field_type->StructSupertype()) {
+          structs_used_in_classes.insert(*field_as_struct);
+        }
+      }
+      if (type->ShouldExport()) {
+        factory_header << type->HandlifiedCppTypeName() << " New"
+                       << type->name() << "(";
+        factory_impl << type->HandlifiedCppTypeName() << " Factory::New"
+                     << type->name() << "(";
+
+        for (const Field& f : type->ComputeAllFields()) {
+          if (f.name_and_type.name == "map") continue;
+          if (!f.index) {
+            std::string type_string =
+                f.name_and_type.type->HandlifiedCppTypeName();
+            factory_header << type_string << " " << f.name_and_type.name
+                           << ", ";
+            factory_impl << type_string << " " << f.name_and_type.name << ", ";
+          }
+        }
+
+        factory_header << "AllocationType allocation_type);\n";
+        factory_impl << "AllocationType allocation_type) {\n";
+
+        factory_impl << " int size = ";
+        const ClassType* super = type->GetSuperClass();
+        std::string gen_name = "TorqueGenerated" + type->name();
+        std::string gen_name_T =
+            gen_name + "<" + type->name() + ", " + super->name() + ">";
+        factory_impl << gen_name_T << "::SizeFor(";
+
+        bool first = true;
+        auto index_fields = GetOrderedUniqueIndexFields(*type);
+        CHECK(index_fields.has_value());
+        for (auto index_field : *index_fields) {
+          if (!first) {
+            factory_impl << ", ";
+          }
+          factory_impl << index_field.name_and_type.name;
+          first = false;
+        }
+
+        factory_impl << ");\n";
+        factory_impl << "  ReadOnlyRoots roots(isolate());\n";
+        factory_impl << "  HeapObject result =\n";
+        factory_impl << "    "
+                        "isolate()->heap()->AllocateRawWith<Heap::kRetryOrFail>"
+                        "(size, allocation_type);\n";
+        factory_impl << "  result.set_map_after_allocation(roots."
+                     << SnakeifyString(type->name())
+                     << "_map(), SKIP_WRITE_BARRIER);\n";
+        factory_impl << "  " << type->HandlifiedCppTypeName()
+                     << " result_handle(" << type->name()
+                     << "::cast(result), isolate());\n";
+
+        for (const Field& f : type->ComputeAllFields()) {
+          if (f.name_and_type.name == "map") continue;
+          if (!f.index) {
+            factory_impl << "  result_handle->set_"
+                         << SnakeifyString(f.name_and_type.name) << "(";
+            if (f.name_and_type.type->IsSubtypeOf(
+                    TypeOracle::GetTaggedType()) &&
+                !f.name_and_type.type->IsSubtypeOf(TypeOracle::GetSmiType())) {
+              factory_impl << "*" << f.name_and_type.name
+                           << ", SKIP_WRITE_BARRIER";
+            } else {
+              factory_impl << f.name_and_type.name;
+            }
+            factory_impl << ");\n";
+          }
+        }
+
+        factory_impl << "  return result_handle;\n";
+        factory_impl << "}\n\n";
+      }
+    }
+
+    for (const StructType* type : structs_used_in_classes) {
+      if (type != TypeOracle::GetFloat64OrHoleType()) {
+        GenerateStructLayoutDescription(external_header, type);
+      }
     }
   }
-  WriteFile(file_basename + ".h", header.str());
-  WriteFile(file_basename + "-inl.h", inline_header.str());
+  WriteFile(file_basename + ".h", external_header.str());
+  WriteFile(file_basename + "-inl.h", inline_external_header.str());
   WriteFile(file_basename + ".cc", implementation.str());
+  WriteFile(internal_file_basename + ".h", internal_header.str());
+  WriteFile(internal_file_basename + "-inl.h", inline_internal_header.str());
+  WriteFile(factory_file_basename + ".inc", factory_header.str());
+  WriteFile(factory_file_basename + ".cc", factory_impl.str());
 }
 
 namespace {
@@ -3651,11 +4020,24 @@ void GeneratePrintDefinitionsForClass(std::ostream& impl, const ClassType* type,
   for (const AggregateType* aggregate_type : hierarchy) {
     for (const Field& f : aggregate_type->fields()) {
       if (f.name_and_type.name == "map") continue;
-      impl << "  os << \"\\n - " << f.name_and_type.name << ": \" << "
-           << "Brief(this->" << f.name_and_type.name << "());\n";
+      if (!f.index.has_value()) {
+        if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetSmiType()) ||
+            !f.name_and_type.type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+          impl << "  os << \"\\n - " << f.name_and_type.name << ": \" << ";
+          if (f.name_and_type.type->StructSupertype()) {
+            // TODO(tebbi): Print struct fields too.
+            impl << "\" <struct field printing still unimplemented>\";\n";
+          } else {
+            impl << "this->" << f.name_and_type.name << "();\n";
+          }
+        } else {
+          impl << "  os << \"\\n - " << f.name_and_type.name << ": \" << "
+               << "Brief(this->" << f.name_and_type.name << "());\n";
+        }
+      }
     }
   }
-  impl << "  os << \"\\n\";\n";
+  impl << "  os << '\\n';\n";
   impl << "}\n\n";
 }
 }  // namespace
@@ -3676,8 +4058,7 @@ void ImplementationVisitor::GeneratePrintDefinitions(
 
     NamespaceScope impl_namespaces(impl, {"v8", "internal"});
 
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       if (!type->ShouldGeneratePrint()) continue;
 
       if (type->GenerateCppClassDefinitions()) {
@@ -3699,6 +4080,142 @@ void ImplementationVisitor::GeneratePrintDefinitions(
   WriteFile(output_directory + "/" + file_name, new_contents);
 }
 
+void ImplementationVisitor::GenerateBodyDescriptors(
+    const std::string& output_directory) {
+  std::string file_name = "objects-body-descriptors-tq-inl";
+  std::stringstream h_contents;
+  {
+    IncludeGuardScope include_guard(h_contents, file_name + ".h");
+
+    h_contents << "\n#include \"src/objects/objects-body-descriptors.h\"\n";
+    h_contents << "\n#include \"torque-generated/class-definitions-tq.h\"\n";
+    h_contents
+        << "\n#include \"torque-generated/internal-class-definitions-tq.h\"\n";
+    h_contents << "\n#include "
+                  "\"torque-generated/internal-class-definitions-tq-inl.h\"\n";
+
+    NamespaceScope h_namespaces(h_contents, {"v8", "internal"});
+
+    for (const ClassType* type : TypeOracle::GetClasses()) {
+      std::string name = type->name();
+      if (!type->ShouldGenerateBodyDescriptor()) continue;
+
+      const ClassType* super_class = type->GetSuperClass();
+      std::string super_name = super_class->name();
+      h_contents << "class " << name
+                 << "::BodyDescriptor final : public BodyDescriptorBase {\n";
+
+      h_contents << " public:\n";
+
+      h_contents << "  static bool IsValidSlot(Map map, HeapObject obj, int "
+                    "offset) {\n";
+
+      if (super_class == TypeOracle::GetHeapObjectType() ||
+          super_class == TypeOracle::GetFixedArrayBaseType()) {
+        h_contents << "    if (offset < " << super_name
+                   << "::kHeaderSize) return true;\n";
+      } else {
+        h_contents << "    if (" << super_name
+                   << "::BodyDescriptor::IsValidSlot(map, obj, offset)) return "
+                      "true;\n";
+      }
+
+      h_contents << "    return offset >= " << name
+                 << "::kStartOfStrongFieldsOffset"
+                 << " && offset < " << name << ""
+                 << "::kEndOfStrongFieldsOffset;\n";
+      h_contents << "  }\n\n";
+
+      h_contents << "  template <typename ObjectVisitor>\n";
+      h_contents << "  static inline void IterateBody(Map map, HeapObject obj, "
+                    "int object_size, ObjectVisitor* v) {\n";
+
+      // There may be MaybeObjects embedded in the strong pointer section, which
+      // are not suppored.
+      for (auto& f : type->fields()) {
+        for (const Type* t : LowerType(f.name_and_type.type)) {
+          if (t->IsSubtypeOf(TypeOracle::GetTaggedType()) &&
+              !t->IsSubtypeOf(TypeOracle::GetObjectType())) {
+            Error("Cannot generate body descriptor for field ",
+                  f.name_and_type.name, " of class ", name, " because ", *t,
+                  " can contain tagged weak pointers.");
+          }
+        }
+      }
+
+      if (super_class != TypeOracle::GetHeapObjectType() &&
+          super_class != TypeOracle::GetFixedArrayBaseType()) {
+        h_contents
+            << "    " << super_name
+            << "::BodyDescriptor::IterateBody(map, obj, object_size, v);\n";
+      }
+
+      h_contents << "    if (" << name
+                 << "::kStartOfStrongFieldsOffset != " << name
+                 << "::kEndOfStrongFieldsOffset) {\n";
+      h_contents << "      IteratePointers(obj, " << name
+                 << "::kStartOfStrongFieldsOffset, " << name
+                 << "::kEndOfStrongFieldsOffset, v);\n";
+      h_contents << "    }\n";
+
+      h_contents << "    if (" << name
+                 << "::kStartOfWeakFieldsOffset != " << name
+                 << "::kEndOfWeakFieldsOffset) {\n";
+      h_contents << "      IterateCustomWeakPointers(obj, " << name
+                 << "::kStartOfWeakFieldsOffset, " << name
+                 << "::kEndOfWeakFieldsOffset, v);\n";
+      h_contents << "    }\n";
+
+      // Since all of the index fields are at the end of the object and must
+      // only be Tagged values, emit only a single IteratePointers from the
+      // beginning of the first indexed field to the end of the object.
+      bool first_index_seen = false;
+      for (const Field& field : type->ComputeAllFields()) {
+        if (field.index && !first_index_seen) {
+          std::string indexed_field_name =
+              CamelifyString(field.name_and_type.name);
+          if (field.name_and_type.type->IsSubtypeOf(
+                  TypeOracle::GetObjectType())) {
+            h_contents << "    BodyDescriptorBase::IteratePointers(obj, "
+                       << name << "::k" << indexed_field_name << "Offset, "
+                       << name << "::SizeFor(" << name << "::cast(obj)), v);\n";
+          } else {
+            Error(
+                "generating body descriptors for indexed fields not subtype of "
+                "Object isn't (yet) supported");
+          }
+          first_index_seen = true;
+        }
+        if (first_index_seen) {
+          for (const Type* t : LowerType(field.name_and_type.type)) {
+            if (!t->IsSubtypeOf(TypeOracle::GetObjectType())) {
+              Error("cannot generate class body descriptor for \"",
+                    type->name(),
+                    "\", all fields of including and after the first indexed "
+                    "member must no comprised only of subtypes of Object "
+                    "(field \"",
+                    field.name_and_type.name, "\" is not)");
+            }
+          }
+        }
+      }
+
+      h_contents << "  }\n\n";
+
+      h_contents
+          << "  static inline int SizeOf(Map map, HeapObject raw_object) {\n";
+      h_contents << "    " << name << " object = " << name
+                 << "::cast(raw_object);\n";
+      h_contents << "    return " << name << "::SizeFor(object);\n";
+      h_contents << "  }\n\n";
+
+      h_contents << "};\n";
+    }
+  }
+
+  WriteFile(output_directory + "/" + file_name + ".h", h_contents.str());
+}
+
 namespace {
 
 // Generate verification code for a single piece of class data, which might be
@@ -3778,7 +4295,7 @@ void GenerateClassFieldVerifier(const std::string& class_name,
   // We only verify tagged types, not raw numbers or pointers. Structs
   // consisting of tagged types are also included.
   if (!field_type->IsSubtypeOf(TypeOracle::GetTaggedType()) &&
-      !field_type->IsStructType())
+      !field_type->StructSupertype())
     return;
   if (field_type == TypeOracle::GetFloat64OrHoleType()) return;
   // Do not verify if the field may be uninitialized.
@@ -3817,11 +4334,13 @@ void GenerateClassFieldVerifier(const std::string& class_name,
     cc_contents << "  {\n";
   }
 
-  if (const StructType* struct_type = StructType::DynamicCast(field_type)) {
-    for (const Field& field : struct_type->fields()) {
-      GenerateFieldValueVerifier(class_name, f, field, *field.offset,
-                                 std::to_string(struct_type->PackedSize()),
-                                 cc_contents);
+  if (auto struct_type = field_type->StructSupertype()) {
+    for (const Field& field : (*struct_type)->fields()) {
+      if (field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+        GenerateFieldValueVerifier(class_name, f, field, *field.offset,
+                                   std::to_string((*struct_type)->PackedSize()),
+                                   cc_contents);
+      }
     }
   } else {
     GenerateFieldValueVerifier(class_name, f, f, 0, "kTaggedSize", cc_contents);
@@ -3858,8 +4377,7 @@ void ImplementationVisitor::GenerateClassVerifiers(
 
     // Generate forward declarations to avoid including any headers.
     h_contents << "class Isolate;\n";
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       if (!type->ShouldGenerateVerify()) continue;
       h_contents << "class " << type->name() << ";\n";
     }
@@ -3869,8 +4387,7 @@ void ImplementationVisitor::GenerateClassVerifiers(
     h_contents << "class " << verifier_class << "{\n";
     h_contents << " public:\n";
 
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       std::string name = type->name();
       if (!type->ShouldGenerateVerify()) continue;
 
@@ -4072,7 +4589,7 @@ void ImplementationVisitor::GenerateCSATypes(
           h_contents << ", ";
         }
         first = false;
-        if (field.name_and_type.type->IsStructType()) {
+        if (field.name_and_type.type->StructSupertype()) {
           h_contents << field.name_and_type.name << ".Flatten()";
         } else {
           h_contents << "std::make_tuple(" << field.name_and_type.name << ")";
diff --git a/deps/v8/src/torque/implementation-visitor.h b/deps/v8/src/torque/implementation-visitor.h
index 0d58b19d46..0cd58aa922 100644
--- a/deps/v8/src/torque/implementation-visitor.h
+++ b/deps/v8/src/torque/implementation-visitor.h
@@ -23,7 +23,7 @@ namespace torque {
 
 template <typename T>
 class Binding;
-struct LocalValue;
+class LocalValue;
 class ImplementationVisitor;
 
 // LocationReference is the representation of an l-value, so a value that might
@@ -55,8 +55,7 @@ class LocationReference {
   // pointer.
   static LocationReference HeapReference(VisitResult heap_reference) {
     LocationReference result;
-    DCHECK(Type::MatchUnaryGeneric(heap_reference.type(),
-                                   TypeOracle::GetReferenceGeneric()));
+    DCHECK(TypeOracle::MatchReferenceGeneric(heap_reference.type()));
     result.heap_reference_ = std::move(heap_reference);
     return result;
   }
@@ -92,7 +91,17 @@ class LocationReference {
     return result;
   }
 
-  bool IsConst() const { return temporary_.has_value(); }
+  bool IsConst() const {
+    if (IsHeapReference()) {
+      bool is_const;
+      bool success =
+          TypeOracle::MatchReferenceGeneric(heap_reference().type(), &is_const)
+              .has_value();
+      CHECK(success);
+      return is_const;
+    }
+    return IsTemporary();
+  }
 
   bool IsVariableAccess() const { return variable_.has_value(); }
   const VisitResult& variable() const {
@@ -130,8 +139,7 @@ class LocationReference {
 
   const Type* ReferencedType() const {
     if (IsHeapReference()) {
-      return *Type::MatchUnaryGeneric(heap_reference().type(),
-                                      TypeOracle::GetReferenceGeneric());
+      return *TypeOracle::MatchReferenceGeneric(heap_reference().type());
     }
     if (IsHeapSlice()) {
       return *Type::MatchUnaryGeneric(heap_slice().type(),
@@ -337,8 +345,32 @@ class BlockBindings {
   std::vector<std::unique_ptr<Binding<T>>> bindings_;
 };
 
-struct LocalValue {
-  LocationReference value;
+class LocalValue {
+ public:
+  explicit LocalValue(LocationReference reference)
+      : value(std::move(reference)) {}
+  explicit LocalValue(std::string inaccessible_explanation)
+      : inaccessible_explanation(std::move(inaccessible_explanation)) {}
+
+  LocationReference GetLocationReference(Binding<LocalValue>* binding) {
+    if (value) {
+      const LocationReference& ref = *value;
+      if (ref.IsVariableAccess()) {
+        // Attach the binding to enable the never-assigned-to lint check.
+        return LocationReference::VariableAccess(ref.GetVisitResult(), binding);
+      }
+      return ref;
+    } else {
+      Error("Cannot access ", binding->name(), ": ", inaccessible_explanation)
+          .Throw();
+    }
+  }
+
+  bool IsAccessible() const { return value.has_value(); }
+
+ private:
+  base::Optional<LocationReference> value;
+  std::string inaccessible_explanation;
 };
 
 struct LocalLabel {
@@ -358,9 +390,10 @@ template <>
 inline bool Binding<LocalValue>::CheckWritten() const {
   // Do the check only for non-const variables and non struct types.
   auto binding = *manager_->current_bindings_[name_];
-  const LocationReference& ref = binding->value;
+  if (!binding->IsAccessible()) return false;
+  const LocationReference& ref = binding->GetLocationReference(binding);
   if (!ref.IsVariableAccess()) return false;
-  return !ref.GetVisitResult().type()->IsStructType();
+  return !ref.GetVisitResult().type()->StructSupertype();
 }
 template <>
 inline std::string Binding<LocalLabel>::BindingTypeString() const {
@@ -388,13 +421,13 @@ class ImplementationVisitor {
   void GenerateBitFields(const std::string& output_directory);
   void GeneratePrintDefinitions(const std::string& output_directory);
   void GenerateClassDefinitions(const std::string& output_directory);
+  void GenerateBodyDescriptors(const std::string& output_directory);
   void GenerateInstanceTypes(const std::string& output_directory);
   void GenerateClassVerifiers(const std::string& output_directory);
   void GenerateEnumVerifiers(const std::string& output_directory);
   void GenerateClassDebugReaders(const std::string& output_directory);
   void GenerateExportedMacrosAssembler(const std::string& output_directory);
   void GenerateCSATypes(const std::string& output_directory);
-  void GenerateCppForInternalClasses(const std::string& output_directory);
 
   VisitResult Visit(Expression* expr);
   const Type* Visit(Statement* stmt);
@@ -411,12 +444,12 @@ class ImplementationVisitor {
   LocationReference GenerateFieldReference(VisitResult object,
                                            const Field& field,
                                            const ClassType* class_type);
-  LocationReference GenerateFieldReference(
+  LocationReference GenerateFieldReferenceForInit(
       VisitResult object, const Field& field,
       const LayoutForInitialization& layout);
   VisitResult GenerateArrayLength(
       Expression* array_length, Namespace* nspace,
-      const std::map<std::string, LocationReference>& bindings);
+      const std::map<std::string, LocalValue>& bindings);
   VisitResult GenerateArrayLength(VisitResult object, const Field& field);
   VisitResult GenerateArrayLength(const ClassType* class_type,
                                   const InitializerResults& initializer_results,
@@ -432,11 +465,13 @@ class ImplementationVisitor {
   VisitResult Visit(StructExpression* decl);
 
   LocationReference GetLocationReference(Expression* location);
+  LocationReference LookupLocalValue(const std::string& name);
   LocationReference GetLocationReference(IdentifierExpression* expr);
   LocationReference GetLocationReference(DereferenceExpression* expr);
   LocationReference GetLocationReference(FieldAccessExpression* expr);
   LocationReference GenerateFieldAccess(
       LocationReference reference, const std::string& fieldname,
+      bool ignore_stuct_field_constness = false,
       base::Optional<SourcePosition> pos = {});
   LocationReference GetLocationReference(ElementAccessExpression* expr);
 
diff --git a/deps/v8/src/torque/instance-type-generator.cc b/deps/v8/src/torque/instance-type-generator.cc
index 3f1aec3777..a06c984629 100644
--- a/deps/v8/src/torque/instance-type-generator.cc
+++ b/deps/v8/src/torque/instance-type-generator.cc
@@ -289,6 +289,8 @@ std::unique_ptr<InstanceTypeTree> AssignInstanceTypes() {
 // - fully_defined_single_instance_types: This list is pairs of class name and
 //   instance type, for classes which have defined layouts and a single
 //   corresponding instance type.
+// - fully_defined_multiple_instance_types: This list is pairs of class name and
+//   instance type, for classes which have defined layouts and subclasses.
 // - only_declared_single_instance_types: This list is pairs of class name and
 //   instance type, for classes which have a single corresponding instance type
 //   and do not have layout definitions in Torque.
@@ -302,6 +304,7 @@ std::unique_ptr<InstanceTypeTree> AssignInstanceTypes() {
 void PrintInstanceTypes(InstanceTypeTree* root, std::ostream& definitions,
                         std::ostream& values,
                         std::ostream& fully_defined_single_instance_types,
+                        std::ostream& fully_defined_multiple_instance_types,
                         std::ostream& only_declared_single_instance_types,
                         std::ostream& fully_defined_range_instance_types,
                         std::ostream& only_declared_range_instance_types,
@@ -331,6 +334,7 @@ void PrintInstanceTypes(InstanceTypeTree* root, std::ostream& definitions,
   for (auto& child : root->children) {
     PrintInstanceTypes(
         child.get(), definitions, values, fully_defined_single_instance_types,
+        fully_defined_multiple_instance_types,
         only_declared_single_instance_types, fully_defined_range_instance_types,
         only_declared_range_instance_types, inner_indent);
   }
@@ -351,6 +355,11 @@ void PrintInstanceTypes(InstanceTypeTree* root, std::ostream& definitions,
                                            : fully_defined_range_instance_types;
       range_instance_types << "  V(" << root->type->name() << ", FIRST_"
                            << type_name << ", LAST_" << type_name << ") \\\n";
+      if (!root->type->IsExtern() && !root->type->IsAbstract() &&
+          !root->type->HasUndefinedLayout()) {
+        fully_defined_multiple_instance_types << "  V(" << root->type->name()
+                                              << ", " << type_name << ") \\\n";
+      }
     }
   }
 }
@@ -370,12 +379,14 @@ void ImplementationVisitor::GenerateInstanceTypes(
     std::unique_ptr<InstanceTypeTree> instance_types = AssignInstanceTypes();
     std::stringstream values_list;
     std::stringstream fully_defined_single_instance_types;
+    std::stringstream fully_defined_multiple_instance_types;
     std::stringstream only_declared_single_instance_types;
     std::stringstream fully_defined_range_instance_types;
     std::stringstream only_declared_range_instance_types;
     if (instance_types != nullptr) {
       PrintInstanceTypes(instance_types.get(), header, values_list,
                          fully_defined_single_instance_types,
+                         fully_defined_multiple_instance_types,
                          only_declared_single_instance_types,
                          fully_defined_range_instance_types,
                          only_declared_range_instance_types, "  ");
@@ -394,6 +405,12 @@ void ImplementationVisitor::GenerateInstanceTypes(
     header << fully_defined_single_instance_types.str();
     header << "\n";
 
+    header << "// Pairs of (ClassName, INSTANCE_TYPE) for classes that have\n";
+    header << "// full Torque definitions and subclasses.\n";
+    header << "#define TORQUE_INSTANCE_CHECKERS_MULTIPLE_FULLY_DEFINED(V) \\\n";
+    header << fully_defined_multiple_instance_types.str();
+    header << "\n";
+
     header << "// Pairs of (ClassName, INSTANCE_TYPE) for classes that are\n";
     header << "// declared but not defined in Torque. These classes may\n";
     header << "// correspond with actual C++ classes, but they are not\n";
@@ -416,10 +433,9 @@ void ImplementationVisitor::GenerateInstanceTypes(
     header << only_declared_range_instance_types.str();
     header << "\n";
 
-    header << "// Instance types for Torque-internal classes.\n";
-    header << "#define TORQUE_INTERNAL_INSTANCE_TYPES(V) \\\n";
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    header << "// Instance types for non-extern Torque classes.\n";
+    header << "#define TORQUE_INSTANCE_TYPES(V) \\\n";
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       if (type->IsExtern()) continue;
       std::string type_name =
           CapifyStringWithUnderscores(type->name()) + "_TYPE";
@@ -427,11 +443,11 @@ void ImplementationVisitor::GenerateInstanceTypes(
     }
     header << "\n";
 
-    header << "// Struct list entries for Torque-internal classes.\n";
-    header << "#define TORQUE_STRUCT_LIST_GENERATOR(V, _) \\\n";
-    for (const TypeAlias* alias : GlobalContext::GetClasses()) {
-      const ClassType* type = ClassType::DynamicCast(alias->type());
+    header << "// Map list macros for non-extern Torque classes.\n";
+    header << "#define TORQUE_INTERNAL_VARSIZE_CLASS_LIST_GENERATOR(V, _) \\\n";
+    for (const ClassType* type : TypeOracle::GetClasses()) {
       if (type->IsExtern()) continue;
+      if (!type->HasIndexedField()) continue;
       std::string type_name =
           CapifyStringWithUnderscores(type->name()) + "_TYPE";
       std::string variable_name = SnakeifyString(type->name());
@@ -439,6 +455,21 @@ void ImplementationVisitor::GenerateInstanceTypes(
              << variable_name << ") \\\n";
     }
     header << "\n";
+    header << "#define TORQUE_INTERNAL_FIXED_CLASS_LIST_GENERATOR(V, _) \\\n";
+    for (const ClassType* type : TypeOracle::GetClasses()) {
+      if (type->IsExtern()) continue;
+      if (type->HasIndexedField()) continue;
+      std::string type_name =
+          CapifyStringWithUnderscores(type->name()) + "_TYPE";
+      std::string variable_name = SnakeifyString(type->name());
+      header << "  V(_, " << type_name << ", " << type->name() << ", "
+             << variable_name << ") \\\n";
+    }
+    header << "\n";
+    header << "#define TORQUE_INTERNAL_CLASS_LIST_GENERATOR(V, _) \\\n";
+    header << "  TORQUE_INTERNAL_VARSIZE_CLASS_LIST_GENERATOR(V, _) \\\n";
+    header << "  TORQUE_INTERNAL_FIXED_CLASS_LIST_GENERATOR(V, _)\n";
+    header << "\n";
   }
   std::string output_header_path = output_directory + "/" + file_name;
   WriteFile(output_header_path, header.str());
diff --git a/deps/v8/src/torque/instructions.cc b/deps/v8/src/torque/instructions.cc
index 81f5c6184c..6acef3018c 100644
--- a/deps/v8/src/torque/instructions.cc
+++ b/deps/v8/src/torque/instructions.cc
@@ -48,6 +48,11 @@ void PeekInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->Push(type);
 }
 
+void PeekInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Push(locations->Peek(slot));
+}
+
 void PokeInstruction::TypeInstruction(Stack<const Type*>* stack,
                                       ControlFlowGraph* cfg) const {
   const Type* type = stack->Top();
@@ -59,26 +64,71 @@ void PokeInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->Pop();
 }
 
+void PokeInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Poke(slot, locations->Pop());
+}
+
 void DeleteRangeInstruction::TypeInstruction(Stack<const Type*>* stack,
                                              ControlFlowGraph* cfg) const {
   stack->DeleteRange(range);
 }
 
+void DeleteRangeInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->DeleteRange(range);
+}
+
 void PushUninitializedInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
   stack->Push(type);
 }
 
+void PushUninitializedInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Push(GetValueDefinition());
+}
+
+DefinitionLocation PushUninitializedInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 void PushBuiltinPointerInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
   stack->Push(type);
 }
 
+void PushBuiltinPointerInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Push(GetValueDefinition());
+}
+
+DefinitionLocation PushBuiltinPointerInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 void NamespaceConstantInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
   stack->PushMany(LowerType(constant->type()));
 }
 
+void NamespaceConstantInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+    locations->Push(GetValueDefinition(i));
+  }
+}
+
+std::size_t NamespaceConstantInstruction::GetValueDefinitionCount() const {
+  return LowerType(constant->type()).size();
+}
+
+DefinitionLocation NamespaceConstantInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
 void InstructionBase::InvalidateTransientTypes(
     Stack<const Type*>* stack) const {
   auto current = stack->begin();
@@ -113,6 +163,26 @@ void CallIntrinsicInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->PushMany(LowerType(intrinsic->signature().return_type));
 }
 
+void CallIntrinsicInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  auto parameter_types =
+      LowerParameterTypes(intrinsic->signature().parameter_types);
+  locations->PopMany(parameter_types.size());
+  for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+    locations->Push(DefinitionLocation::Instruction(this, i));
+  }
+}
+
+std::size_t CallIntrinsicInstruction::GetValueDefinitionCount() const {
+  return LowerType(intrinsic->signature().return_type).size();
+}
+
+DefinitionLocation CallIntrinsicInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
 void CallCsaMacroInstruction::TypeInstruction(Stack<const Type*>* stack,
                                               ControlFlowGraph* cfg) const {
   std::vector<const Type*> parameter_types =
@@ -140,6 +210,39 @@ void CallCsaMacroInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->PushMany(LowerType(macro->signature().return_type));
 }
 
+void CallCsaMacroInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  auto parameter_types =
+      LowerParameterTypes(macro->signature().parameter_types);
+  locations->PopMany(parameter_types.size());
+
+  if (catch_block) {
+    locations->Push(*GetExceptionObjectDefinition());
+    (*catch_block)->MergeInputDefinitions(*locations, worklist);
+    locations->Pop();
+  }
+
+  for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+    locations->Push(GetValueDefinition(i));
+  }
+}
+
+base::Optional<DefinitionLocation>
+CallCsaMacroInstruction::GetExceptionObjectDefinition() const {
+  if (!catch_block) return base::nullopt;
+  return DefinitionLocation::Instruction(this, GetValueDefinitionCount());
+}
+
+std::size_t CallCsaMacroInstruction::GetValueDefinitionCount() const {
+  return LowerType(macro->signature().return_type).size();
+}
+
+DefinitionLocation CallCsaMacroInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
 void CallCsaMacroAndBranchInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
   std::vector<const Type*> parameter_types =
@@ -188,6 +291,78 @@ void CallCsaMacroAndBranchInstruction::TypeInstruction(
   }
 }
 
+void CallCsaMacroAndBranchInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  auto parameter_types =
+      LowerParameterTypes(macro->signature().parameter_types);
+  locations->PopMany(parameter_types.size());
+
+  for (std::size_t label_index = 0; label_index < label_blocks.size();
+       ++label_index) {
+    const std::size_t count = GetLabelValueDefinitionCount(label_index);
+    for (std::size_t i = 0; i < count; ++i) {
+      locations->Push(GetLabelValueDefinition(label_index, i));
+    }
+    label_blocks[label_index]->MergeInputDefinitions(*locations, worklist);
+    locations->PopMany(count);
+  }
+
+  if (catch_block) {
+    locations->Push(*GetExceptionObjectDefinition());
+    (*catch_block)->MergeInputDefinitions(*locations, worklist);
+    locations->Pop();
+  }
+
+  if (macro->signature().return_type != TypeOracle::GetNeverType()) {
+    if (return_continuation) {
+      const std::size_t count = GetValueDefinitionCount();
+      for (std::size_t i = 0; i < count; ++i) {
+        locations->Push(GetValueDefinition(i));
+      }
+      (*return_continuation)->MergeInputDefinitions(*locations, worklist);
+      locations->PopMany(count);
+    }
+  }
+}
+
+std::size_t CallCsaMacroAndBranchInstruction::GetLabelCount() const {
+  return label_blocks.size();
+}
+
+std::size_t CallCsaMacroAndBranchInstruction::GetLabelValueDefinitionCount(
+    std::size_t label) const {
+  DCHECK_LT(label, GetLabelCount());
+  return LowerParameterTypes(macro->signature().labels[label].types).size();
+}
+
+DefinitionLocation CallCsaMacroAndBranchInstruction::GetLabelValueDefinition(
+    std::size_t label, std::size_t index) const {
+  DCHECK_LT(index, GetLabelValueDefinitionCount(label));
+  std::size_t offset = GetValueDefinitionCount() + (catch_block ? 1 : 0);
+  for (std::size_t label_index = 0; label_index < label; ++label_index) {
+    offset += GetLabelValueDefinitionCount(label_index);
+  }
+  return DefinitionLocation::Instruction(this, offset + index);
+}
+
+std::size_t CallCsaMacroAndBranchInstruction::GetValueDefinitionCount() const {
+  if (macro->signature().return_type == TypeOracle::GetNeverType()) return 0;
+  if (!return_continuation) return 0;
+  return LowerType(macro->signature().return_type).size();
+}
+
+DefinitionLocation CallCsaMacroAndBranchInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
+base::Optional<DefinitionLocation>
+CallCsaMacroAndBranchInstruction::GetExceptionObjectDefinition() const {
+  if (!catch_block) return base::nullopt;
+  return DefinitionLocation::Instruction(this, GetValueDefinitionCount());
+}
+
 void CallBuiltinInstruction::TypeInstruction(Stack<const Type*>* stack,
                                              ControlFlowGraph* cfg) const {
   std::vector<const Type*> argument_types = stack->PopMany(argc);
@@ -208,6 +383,37 @@ void CallBuiltinInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->PushMany(LowerType(builtin->signature().return_type));
 }
 
+void CallBuiltinInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->PopMany(argc);
+
+  if (catch_block) {
+    locations->Push(*GetExceptionObjectDefinition());
+    (*catch_block)->MergeInputDefinitions(*locations, worklist);
+    locations->Pop();
+  }
+
+  for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+    locations->Push(GetValueDefinition(i));
+  }
+}
+
+std::size_t CallBuiltinInstruction::GetValueDefinitionCount() const {
+  return LowerType(builtin->signature().return_type).size();
+}
+
+DefinitionLocation CallBuiltinInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
+base::Optional<DefinitionLocation>
+CallBuiltinInstruction::GetExceptionObjectDefinition() const {
+  if (!catch_block) return base::nullopt;
+  return DefinitionLocation::Instruction(this, GetValueDefinitionCount());
+}
+
 void CallBuiltinPointerInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
   std::vector<const Type*> argument_types = stack->PopMany(argc);
@@ -216,12 +422,31 @@ void CallBuiltinPointerInstruction::TypeInstruction(
   if (argument_types != LowerParameterTypes(f->parameter_types())) {
     ReportError("wrong argument types");
   }
+  DCHECK_EQ(type, f);
   // TODO(tebbi): Only invalidate transient types if the function pointer type
   // is transitioning.
   InvalidateTransientTypes(stack);
   stack->PushMany(LowerType(f->return_type()));
 }
 
+void CallBuiltinPointerInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->PopMany(argc + 1);
+  for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+    locations->Push(GetValueDefinition(i));
+  }
+}
+
+std::size_t CallBuiltinPointerInstruction::GetValueDefinitionCount() const {
+  return LowerType(type->return_type()).size();
+}
+
+DefinitionLocation CallBuiltinPointerInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
 void CallRuntimeInstruction::TypeInstruction(Stack<const Type*>* stack,
                                              ControlFlowGraph* cfg) const {
   std::vector<const Type*> argument_types = stack->PopMany(argc);
@@ -246,6 +471,42 @@ void CallRuntimeInstruction::TypeInstruction(Stack<const Type*>* stack,
   }
 }
 
+void CallRuntimeInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->PopMany(argc);
+
+  if (catch_block) {
+    locations->Push(*GetExceptionObjectDefinition());
+    (*catch_block)->MergeInputDefinitions(*locations, worklist);
+    locations->Pop();
+  }
+
+  const Type* return_type = runtime_function->signature().return_type;
+  if (return_type != TypeOracle::GetNeverType()) {
+    for (std::size_t i = 0; i < GetValueDefinitionCount(); ++i) {
+      locations->Push(GetValueDefinition(i));
+    }
+  }
+}
+
+std::size_t CallRuntimeInstruction::GetValueDefinitionCount() const {
+  const Type* return_type = runtime_function->signature().return_type;
+  if (return_type == TypeOracle::GetNeverType()) return 0;
+  return LowerType(return_type).size();
+}
+
+DefinitionLocation CallRuntimeInstruction::GetValueDefinition(
+    std::size_t index) const {
+  DCHECK_LT(index, GetValueDefinitionCount());
+  return DefinitionLocation::Instruction(this, index);
+}
+
+base::Optional<DefinitionLocation>
+CallRuntimeInstruction::GetExceptionObjectDefinition() const {
+  if (!catch_block) return base::nullopt;
+  return DefinitionLocation::Instruction(this, GetValueDefinitionCount());
+}
+
 void BranchInstruction::TypeInstruction(Stack<const Type*>* stack,
                                         ControlFlowGraph* cfg) const {
   const Type* condition_type = stack->Pop();
@@ -256,17 +517,35 @@ void BranchInstruction::TypeInstruction(Stack<const Type*>* stack,
   if_false->SetInputTypes(*stack);
 }
 
+void BranchInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+  if_true->MergeInputDefinitions(*locations, worklist);
+  if_false->MergeInputDefinitions(*locations, worklist);
+}
+
 void ConstexprBranchInstruction::TypeInstruction(Stack<const Type*>* stack,
                                                  ControlFlowGraph* cfg) const {
   if_true->SetInputTypes(*stack);
   if_false->SetInputTypes(*stack);
 }
 
+void ConstexprBranchInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  if_true->MergeInputDefinitions(*locations, worklist);
+  if_false->MergeInputDefinitions(*locations, worklist);
+}
+
 void GotoInstruction::TypeInstruction(Stack<const Type*>* stack,
                                       ControlFlowGraph* cfg) const {
   destination->SetInputTypes(*stack);
 }
 
+void GotoInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  destination->MergeInputDefinitions(*locations, worklist);
+}
+
 void GotoExternalInstruction::TypeInstruction(Stack<const Type*>* stack,
                                               ControlFlowGraph* cfg) const {
   if (variable_names.size() != stack->Size()) {
@@ -274,22 +553,45 @@ void GotoExternalInstruction::TypeInstruction(Stack<const Type*>* stack,
   }
 }
 
+void GotoExternalInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {}
+
 void ReturnInstruction::TypeInstruction(Stack<const Type*>* stack,
                                         ControlFlowGraph* cfg) const {
   cfg->SetReturnType(stack->Pop());
 }
 
+void ReturnInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+}
+
 void PrintConstantStringInstruction::TypeInstruction(
     Stack<const Type*>* stack, ControlFlowGraph* cfg) const {}
 
+void PrintConstantStringInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {}
+
 void AbortInstruction::TypeInstruction(Stack<const Type*>* stack,
                                        ControlFlowGraph* cfg) const {}
 
+void AbortInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {}
+
 void UnsafeCastInstruction::TypeInstruction(Stack<const Type*>* stack,
                                             ControlFlowGraph* cfg) const {
   stack->Poke(stack->AboveTop() - 1, destination_type);
 }
 
+void UnsafeCastInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Poke(locations->AboveTop() - 1, GetValueDefinition());
+}
+
+DefinitionLocation UnsafeCastInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 void LoadReferenceInstruction::TypeInstruction(Stack<const Type*>* stack,
                                                ControlFlowGraph* cfg) const {
   ExpectType(TypeOracle::GetIntPtrType(), stack->Pop());
@@ -298,6 +600,17 @@ void LoadReferenceInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->Push(type);
 }
 
+void LoadReferenceInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+  locations->Pop();
+  locations->Push(GetValueDefinition());
+}
+
+DefinitionLocation LoadReferenceInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 void StoreReferenceInstruction::TypeInstruction(Stack<const Type*>* stack,
                                                 ControlFlowGraph* cfg) const {
   ExpectSubtype(stack->Pop(), type);
@@ -305,12 +618,29 @@ void StoreReferenceInstruction::TypeInstruction(Stack<const Type*>* stack,
   ExpectSubtype(stack->Pop(), TypeOracle::GetHeapObjectType());
 }
 
+void StoreReferenceInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+  locations->Pop();
+  locations->Pop();
+}
+
 void LoadBitFieldInstruction::TypeInstruction(Stack<const Type*>* stack,
                                               ControlFlowGraph* cfg) const {
   ExpectType(bit_field_struct_type, stack->Pop());
   stack->Push(bit_field.name_and_type.type);
 }
 
+void LoadBitFieldInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+  locations->Push(GetValueDefinition());
+}
+
+DefinitionLocation LoadBitFieldInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 void StoreBitFieldInstruction::TypeInstruction(Stack<const Type*>* stack,
                                                ControlFlowGraph* cfg) const {
   ExpectSubtype(bit_field.name_and_type.type, stack->Pop());
@@ -318,6 +648,17 @@ void StoreBitFieldInstruction::TypeInstruction(Stack<const Type*>* stack,
   stack->Push(bit_field_struct_type);
 }
 
+void StoreBitFieldInstruction::RecomputeDefinitionLocations(
+    Stack<DefinitionLocation>* locations, Worklist<Block*>* worklist) const {
+  locations->Pop();
+  locations->Pop();
+  locations->Push(GetValueDefinition());
+}
+
+DefinitionLocation StoreBitFieldInstruction::GetValueDefinition() const {
+  return DefinitionLocation::Instruction(this, 0);
+}
+
 bool CallRuntimeInstruction::IsBlockTerminator() const {
   return is_tailcall || runtime_function->signature().return_type ==
                             TypeOracle::GetNeverType();
diff --git a/deps/v8/src/torque/instructions.h b/deps/v8/src/torque/instructions.h
index cb560274fe..2d5eff71da 100644
--- a/deps/v8/src/torque/instructions.h
+++ b/deps/v8/src/torque/instructions.h
@@ -50,11 +50,14 @@ class RuntimeFunction;
   V(AbortInstruction)                 \
   V(UnsafeCastInstruction)
 
-#define TORQUE_INSTRUCTION_BOILERPLATE()                                 \
-  static const InstructionKind kKind;                                    \
-  std::unique_ptr<InstructionBase> Clone() const override;               \
-  void Assign(const InstructionBase& other) override;                    \
-  void TypeInstruction(Stack<const Type*>* stack, ControlFlowGraph* cfg) \
+#define TORQUE_INSTRUCTION_BOILERPLATE()                                  \
+  static const InstructionKind kKind;                                     \
+  std::unique_ptr<InstructionBase> Clone() const override;                \
+  void Assign(const InstructionBase& other) override;                     \
+  void TypeInstruction(Stack<const Type*>* stack, ControlFlowGraph* cfg)  \
+      const override;                                                     \
+  void RecomputeDefinitionLocations(Stack<DefinitionLocation>* locations, \
+                                    Worklist<Block*>* worklist)           \
       const override;
 
 enum class InstructionKind {
@@ -63,6 +66,115 @@ enum class InstructionKind {
 #undef ENUM_ITEM
 };
 
+struct InstructionBase;
+
+class DefinitionLocation {
+ public:
+  enum class Kind {
+    kInvalid,
+    kParameter,
+    kPhi,
+    kInstruction,
+  };
+
+  DefinitionLocation() : kind_(Kind::kInvalid), location_(nullptr), index_(0) {}
+
+  static DefinitionLocation Parameter(std::size_t index) {
+    return DefinitionLocation(Kind::kParameter, nullptr, index);
+  }
+
+  static DefinitionLocation Phi(const Block* block, std::size_t index) {
+    return DefinitionLocation(Kind::kPhi, block, index);
+  }
+
+  static DefinitionLocation Instruction(const InstructionBase* instruction,
+                                        std::size_t index = 0) {
+    return DefinitionLocation(Kind::kInstruction, instruction, index);
+  }
+
+  Kind GetKind() const { return kind_; }
+  bool IsValid() const { return kind_ != Kind::kInvalid; }
+  bool IsParameter() const { return kind_ == Kind::kParameter; }
+  bool IsPhi() const { return kind_ == Kind::kPhi; }
+  bool IsInstruction() const { return kind_ == Kind::kInstruction; }
+
+  std::size_t GetParameterIndex() const {
+    DCHECK(IsParameter());
+    return index_;
+  }
+
+  const Block* GetPhiBlock() const {
+    DCHECK(IsPhi());
+    return reinterpret_cast<const Block*>(location_);
+  }
+
+  bool IsPhiFromBlock(const Block* block) const {
+    return IsPhi() && GetPhiBlock() == block;
+  }
+
+  std::size_t GetPhiIndex() const {
+    DCHECK(IsPhi());
+    return index_;
+  }
+
+  const InstructionBase* GetInstruction() const {
+    DCHECK(IsInstruction());
+    return reinterpret_cast<const InstructionBase*>(location_);
+  }
+
+  std::size_t GetInstructionIndex() const {
+    DCHECK(IsInstruction());
+    return index_;
+  }
+
+  bool operator==(const DefinitionLocation& other) const {
+    if (kind_ != other.kind_) return false;
+    if (location_ != other.location_) return false;
+    return index_ == other.index_;
+  }
+
+  bool operator!=(const DefinitionLocation& other) const {
+    return !operator==(other);
+  }
+
+  bool operator<(const DefinitionLocation& other) const {
+    if (kind_ != other.kind_) {
+      return static_cast<int>(kind_) < static_cast<int>(other.kind_);
+    }
+    if (location_ != other.location_) {
+      return location_ < other.location_;
+    }
+    return index_ < other.index_;
+  }
+
+ private:
+  DefinitionLocation(Kind kind, const void* location, std::size_t index)
+      : kind_(kind), location_(location), index_(index) {}
+
+  Kind kind_;
+  const void* location_;
+  std::size_t index_;
+};
+
+inline std::ostream& operator<<(std::ostream& stream,
+                                const DefinitionLocation& loc) {
+  switch (loc.GetKind()) {
+    case DefinitionLocation::Kind::kInvalid:
+      return stream << "DefinitionLocation::Invalid()";
+    case DefinitionLocation::Kind::kParameter:
+      return stream << "DefinitionLocation::Parameter("
+                    << loc.GetParameterIndex() << ")";
+    case DefinitionLocation::Kind::kPhi:
+      return stream << "DefinitionLocation::Phi(" << std::hex
+                    << (uint64_t)loc.GetPhiBlock() << std::dec << ", "
+                    << loc.GetPhiIndex() << ")";
+    case DefinitionLocation::Kind::kInstruction:
+      return stream << "DefinitionLocation::Instruction(" << std::hex
+                    << (uint64_t)loc.GetInstruction() << std::dec << ", "
+                    << loc.GetInstructionIndex() << ")";
+  }
+}
+
 struct InstructionBase {
   InstructionBase() : pos(CurrentSourcePosition::Get()) {}
   virtual std::unique_ptr<InstructionBase> Clone() const = 0;
@@ -71,6 +183,9 @@ struct InstructionBase {
 
   virtual void TypeInstruction(Stack<const Type*>* stack,
                                ControlFlowGraph* cfg) const = 0;
+  virtual void RecomputeDefinitionLocations(
+      Stack<DefinitionLocation>* locations,
+      Worklist<Block*>* worklist) const = 0;
   void InvalidateTransientTypes(Stack<const Type*>* stack) const;
   virtual bool IsBlockTerminator() const { return false; }
   virtual void AppendSuccessorBlocks(std::vector<Block*>* block_list) const {}
@@ -141,6 +256,10 @@ class Instruction {
   void TypeInstruction(Stack<const Type*>* stack, ControlFlowGraph* cfg) const {
     return instruction_->TypeInstruction(stack, cfg);
   }
+  void RecomputeDefinitionLocations(Stack<DefinitionLocation>* locations,
+                                    Worklist<Block*>* worklist) const {
+    instruction_->RecomputeDefinitionLocations(locations, worklist);
+  }
 
   InstructionBase* operator->() { return instruction_.get(); }
   const InstructionBase* operator->() const { return instruction_.get(); }
@@ -183,6 +302,8 @@ struct PushUninitializedInstruction : InstructionBase {
   TORQUE_INSTRUCTION_BOILERPLATE()
   explicit PushUninitializedInstruction(const Type* type) : type(type) {}
 
+  DefinitionLocation GetValueDefinition() const;
+
   const Type* type;
 };
 
@@ -193,6 +314,8 @@ struct PushBuiltinPointerInstruction : InstructionBase {
     DCHECK(type->IsBuiltinPointerType());
   }
 
+  DefinitionLocation GetValueDefinition() const;
+
   std::string external_name;
   const Type* type;
 };
@@ -202,12 +325,18 @@ struct NamespaceConstantInstruction : InstructionBase {
   explicit NamespaceConstantInstruction(NamespaceConstant* constant)
       : constant(constant) {}
 
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+
   NamespaceConstant* constant;
 };
 
 struct LoadReferenceInstruction : InstructionBase {
   TORQUE_INSTRUCTION_BOILERPLATE()
   explicit LoadReferenceInstruction(const Type* type) : type(type) {}
+
+  DefinitionLocation GetValueDefinition() const;
+
   const Type* type;
 };
 
@@ -224,6 +353,9 @@ struct LoadBitFieldInstruction : InstructionBase {
                           BitField bit_field)
       : bit_field_struct_type(bit_field_struct_type),
         bit_field(std::move(bit_field)) {}
+
+  DefinitionLocation GetValueDefinition() const;
+
   const BitFieldStructType* bit_field_struct_type;
   BitField bit_field;
 };
@@ -236,6 +368,9 @@ struct StoreBitFieldInstruction : InstructionBase {
                            BitField bit_field)
       : bit_field_struct_type(bit_field_struct_type),
         bit_field(std::move(bit_field)) {}
+
+  DefinitionLocation GetValueDefinition() const;
+
   const BitFieldStructType* bit_field_struct_type;
   BitField bit_field;
 };
@@ -249,6 +384,9 @@ struct CallIntrinsicInstruction : InstructionBase {
         specialization_types(std::move(specialization_types)),
         constexpr_arguments(constexpr_arguments) {}
 
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+
   Intrinsic* intrinsic;
   TypeVector specialization_types;
   std::vector<std::string> constexpr_arguments;
@@ -266,6 +404,10 @@ struct CallCsaMacroInstruction : InstructionBase {
     if (catch_block) block_list->push_back(*catch_block);
   }
 
+  base::Optional<DefinitionLocation> GetExceptionObjectDefinition() const;
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+
   Macro* macro;
   std::vector<std::string> constexpr_arguments;
   base::Optional<Block*> catch_block;
@@ -290,6 +432,14 @@ struct CallCsaMacroAndBranchInstruction : InstructionBase {
     for (Block* block : label_blocks) block_list->push_back(block);
   }
 
+  std::size_t GetLabelCount() const;
+  std::size_t GetLabelValueDefinitionCount(std::size_t label) const;
+  DefinitionLocation GetLabelValueDefinition(std::size_t label,
+                                             std::size_t index) const;
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+  base::Optional<DefinitionLocation> GetExceptionObjectDefinition() const;
+
   Macro* macro;
   std::vector<std::string> constexpr_arguments;
   base::Optional<Block*> return_continuation;
@@ -310,6 +460,10 @@ struct CallBuiltinInstruction : InstructionBase {
     if (catch_block) block_list->push_back(*catch_block);
   }
 
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+  base::Optional<DefinitionLocation> GetExceptionObjectDefinition() const;
+
   bool is_tailcall;
   Builtin* builtin;
   size_t argc;
@@ -323,6 +477,9 @@ struct CallBuiltinPointerInstruction : InstructionBase {
                                 const BuiltinPointerType* type, size_t argc)
       : is_tailcall(is_tailcall), type(type), argc(argc) {}
 
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+
   bool is_tailcall;
   const BuiltinPointerType* type;
   size_t argc;
@@ -342,6 +499,10 @@ struct CallRuntimeInstruction : InstructionBase {
     if (catch_block) block_list->push_back(*catch_block);
   }
 
+  std::size_t GetValueDefinitionCount() const;
+  DefinitionLocation GetValueDefinition(std::size_t index) const;
+  base::Optional<DefinitionLocation> GetExceptionObjectDefinition() const;
+
   bool is_tailcall;
   RuntimeFunction* runtime_function;
   size_t argc;
@@ -434,6 +595,8 @@ struct UnsafeCastInstruction : InstructionBase {
   explicit UnsafeCastInstruction(const Type* destination_type)
       : destination_type(destination_type) {}
 
+  DefinitionLocation GetValueDefinition() const;
+
   const Type* destination_type;
 };
 
diff --git a/deps/v8/src/torque/torque-compiler.cc b/deps/v8/src/torque/torque-compiler.cc
index cb41cff946..ad7d906d54 100644
--- a/deps/v8/src/torque/torque-compiler.cc
+++ b/deps/v8/src/torque/torque-compiler.cc
@@ -88,10 +88,10 @@ void CompileCurrentAst(TorqueCompilerOptions options) {
   implementation_visitor.GenerateClassVerifiers(output_directory);
   implementation_visitor.GenerateClassDebugReaders(output_directory);
   implementation_visitor.GenerateEnumVerifiers(output_directory);
+  implementation_visitor.GenerateBodyDescriptors(output_directory);
   implementation_visitor.GenerateExportedMacrosAssembler(output_directory);
   implementation_visitor.GenerateCSATypes(output_directory);
   implementation_visitor.GenerateInstanceTypes(output_directory);
-  implementation_visitor.GenerateCppForInternalClasses(output_directory);
 
   implementation_visitor.EndCSAFiles();
   implementation_visitor.GenerateImplementation(output_directory);
diff --git a/deps/v8/src/torque/torque-parser.cc b/deps/v8/src/torque/torque-parser.cc
index c6b63e2234..e63827db2c 100644
--- a/deps/v8/src/torque/torque-parser.cc
+++ b/deps/v8/src/torque/torque-parser.cc
@@ -8,7 +8,8 @@
 #include <stdexcept>
 #include <unordered_map>
 
-#include "src/common/globals.h"
+#include "src/flags/flags.h"
+#include "src/torque/ast.h"
 #include "src/torque/constants.h"
 #include "src/torque/declarations.h"
 #include "src/torque/earley-parser.h"
@@ -41,6 +42,8 @@ class BuildFlags : public ContextualClass<BuildFlags> {
     build_flags_["V8_SFI_HAS_UNIQUE_ID"] = V8_SFI_HAS_UNIQUE_ID;
     build_flags_["TAGGED_SIZE_8_BYTES"] = TAGGED_SIZE_8_BYTES;
     build_flags_["V8_DOUBLE_FIELDS_UNBOXING"] = V8_DOUBLE_FIELDS_UNBOXING;
+    build_flags_["V8_ARRAY_BUFFER_EXTENSION_BOOL"] =
+        V8_ARRAY_BUFFER_EXTENSION_BOOL;
     build_flags_["TRUE_FOR_TESTING"] = true;
     build_flags_["FALSE_FOR_TESTING"] = false;
   }
@@ -300,6 +303,14 @@ void CheckNotDeferredStatement(Statement* statement) {
   }
 }
 
+TypeExpression* AddConstexpr(TypeExpression* type) {
+  BasicTypeExpression* basic = BasicTypeExpression::DynamicCast(type);
+  if (!basic) Error("Unsupported extends clause.").Throw();
+  return MakeNode<BasicTypeExpression>(basic->namespace_qualification,
+                                       CONSTEXPR_TYPE_PREFIX + basic->name,
+                                       basic->generic_arguments);
+}
+
 Expression* MakeCall(IdentifierExpression* callee,
                      base::Optional<Expression*> target,
                      std::vector<Expression*> arguments,
@@ -547,9 +558,24 @@ base::Optional<ParseResult> MakeIntrinsicDeclaration(
   return ParseResult{result};
 }
 
+namespace {
+bool HasExportAnnotation(ParseResultIterator* child_results,
+                         const char* declaration) {
+  auto annotations = child_results->NextAs<std::vector<Annotation>>();
+  if (annotations.size()) {
+    if (annotations.size() > 1 || annotations[0].name->value != "@export") {
+      Error(declaration,
+            " declarations only support a single @export annotation");
+    }
+    return true;
+  }
+  return false;
+}
+}  // namespace
+
 base::Optional<ParseResult> MakeTorqueMacroDeclaration(
     ParseResultIterator* child_results) {
-  auto export_to_csa = child_results->NextAs<bool>();
+  bool export_to_csa = HasExportAnnotation(child_results, "macro");
   auto transitioning = child_results->NextAs<bool>();
   auto operator_name = child_results->NextAs<base::Optional<std::string>>();
   auto name = child_results->NextAs<Identifier*>();
@@ -644,7 +670,7 @@ base::Optional<ParseResult> MakeAbstractTypeDeclaration(
     NamingConventionError("Type", name, "UpperCamelCase");
   }
   auto generic_parameters = child_results->NextAs<GenericParameters>();
-  auto extends = child_results->NextAs<base::Optional<Identifier*>>();
+  auto extends = child_results->NextAs<base::Optional<TypeExpression*>>();
   auto generates = child_results->NextAs<base::Optional<std::string>>();
   TypeDeclaration* type_decl = MakeNode<AbstractTypeDeclaration>(
       name, transient, extends, std::move(generates));
@@ -663,11 +689,9 @@ base::Optional<ParseResult> MakeAbstractTypeDeclaration(
         MakeNode<Identifier>(CONSTEXPR_TYPE_PREFIX + name->value);
     constexpr_name->pos = name->pos;
 
-    base::Optional<Identifier*> constexpr_extends;
+    base::Optional<TypeExpression*> constexpr_extends;
     if (extends) {
-      constexpr_extends =
-          MakeNode<Identifier>(CONSTEXPR_TYPE_PREFIX + (*extends)->value);
-      (*constexpr_extends)->pos = name->pos;
+      constexpr_extends = AddConstexpr(*extends);
     }
     TypeDeclaration* constexpr_decl = MakeNode<AbstractTypeDeclaration>(
         constexpr_name, transient, constexpr_extends, constexpr_generates);
@@ -833,7 +857,8 @@ base::Optional<ParseResult> MakeClassDeclaration(
       child_results,
       {ANNOTATION_GENERATE_PRINT, ANNOTATION_NO_VERIFIER, ANNOTATION_ABSTRACT,
        ANNOTATION_HAS_SAME_INSTANCE_TYPE_AS_PARENT,
-       ANNOTATION_GENERATE_CPP_CLASS,
+       ANNOTATION_GENERATE_CPP_CLASS, ANNOTATION_GENERATE_BODY_DESCRIPTOR,
+       ANNOTATION_EXPORT_CPP_CLASS,
        ANNOTATION_HIGHEST_INSTANCE_TYPE_WITHIN_PARENT,
        ANNOTATION_LOWEST_INSTANCE_TYPE_WITHIN_PARENT},
       {ANNOTATION_RESERVE_BITS_IN_INSTANCE_TYPE,
@@ -852,6 +877,12 @@ base::Optional<ParseResult> MakeClassDeclaration(
   if (annotations.Contains(ANNOTATION_GENERATE_CPP_CLASS)) {
     flags |= ClassFlag::kGenerateCppClassDefinitions;
   }
+  if (annotations.Contains(ANNOTATION_GENERATE_BODY_DESCRIPTOR)) {
+    flags |= ClassFlag::kGenerateBodyDescriptor;
+  }
+  if (annotations.Contains(ANNOTATION_EXPORT_CPP_CLASS)) {
+    flags |= ClassFlag::kExport;
+  }
   if (annotations.Contains(ANNOTATION_HIGHEST_INSTANCE_TYPE_WITHIN_PARENT)) {
     flags |= ClassFlag::kHighestInstanceTypeWithinParent;
   }
@@ -943,7 +974,8 @@ base::Optional<ParseResult> MakeSpecializationDeclaration(
 
 base::Optional<ParseResult> MakeStructDeclaration(
     ParseResultIterator* child_results) {
-  bool is_export = child_results->NextAs<bool>();
+  bool is_export = HasExportAnnotation(child_results, "Struct");
+
   StructFlags flags = StructFlag::kNone;
   if (is_export) flags |= StructFlag::kExport;
 
@@ -1065,12 +1097,15 @@ base::Optional<ParseResult> MakeFunctionTypeExpression(
 
 base::Optional<ParseResult> MakeReferenceTypeExpression(
     ParseResultIterator* child_results) {
+  auto is_const = child_results->NextAs<bool>();
   auto referenced_type = child_results->NextAs<TypeExpression*>();
   std::vector<std::string> namespace_qualification{
       TORQUE_INTERNAL_NAMESPACE_STRING};
   std::vector<TypeExpression*> generic_arguments{referenced_type};
   TypeExpression* result = MakeNode<BasicTypeExpression>(
-      namespace_qualification, REFERENCE_TYPE_STRING, generic_arguments);
+      namespace_qualification,
+      is_const ? CONST_REFERENCE_TYPE_STRING : MUTABLE_REFERENCE_TYPE_STRING,
+      generic_arguments);
   return ParseResult{result};
 }
 
@@ -1124,7 +1159,8 @@ base::Optional<ParseResult> MakeEnumDeclaration(
   const bool is_extern = child_results->NextAs<bool>();
   auto name_identifier = child_results->NextAs<Identifier*>();
   auto name = name_identifier->value;
-  auto base_identifier = child_results->NextAs<base::Optional<Identifier*>>();
+  auto base_type_expression =
+      child_results->NextAs<base::Optional<TypeExpression*>>();
   auto constexpr_generates_opt =
       child_results->NextAs<base::Optional<std::string>>();
   auto entries = child_results->NextAs<std::vector<Identifier*>>();
@@ -1142,12 +1178,12 @@ base::Optional<ParseResult> MakeEnumDeclaration(
 
   auto constexpr_generates =
       constexpr_generates_opt ? *constexpr_generates_opt : name;
-  const bool generate_nonconstexpr = base_identifier.has_value();
+  const bool generate_nonconstexpr = base_type_expression.has_value();
 
   std::vector<Declaration*> result;
   // Build non-constexpr types.
   if (generate_nonconstexpr) {
-    DCHECK(base_identifier.has_value());
+    DCHECK(base_type_expression.has_value());
 
     if (is_open) {
       // For open enumerations, we define an abstract type and inherit all
@@ -1159,12 +1195,16 @@ base::Optional<ParseResult> MakeEnumDeclaration(
       //     type kEntryN extends Enum;
       //   }
       auto type_decl = MakeNode<AbstractTypeDeclaration>(
-          name_identifier, false, base_identifier, base::nullopt);
+          name_identifier, false, base_type_expression, base::nullopt);
+
+      TypeExpression* name_type_expression =
+          MakeNode<BasicTypeExpression>(name_identifier->value);
+      name_type_expression->pos = name_identifier->pos;
 
       std::vector<Declaration*> entry_decls;
       for (const auto& entry_name_identifier : entries) {
         entry_decls.push_back(MakeNode<AbstractTypeDeclaration>(
-            entry_name_identifier, false, name_identifier, base::nullopt));
+            entry_name_identifier, false, name_type_expression, base::nullopt));
       }
 
       result.push_back(type_decl);
@@ -1183,7 +1223,7 @@ base::Optional<ParseResult> MakeEnumDeclaration(
       std::vector<Declaration*> entry_decls;
       for (const auto& entry_name_identifier : entries) {
         entry_decls.push_back(MakeNode<AbstractTypeDeclaration>(
-            entry_name_identifier, false, base_identifier, base::nullopt));
+            entry_name_identifier, false, base_type_expression, base::nullopt));
 
         auto entry_type = MakeNode<BasicTypeExpression>(
             std::vector<std::string>{name}, entry_name_identifier->value,
@@ -1213,13 +1253,15 @@ base::Optional<ParseResult> MakeEnumDeclaration(
     //   }
     Identifier* constexpr_type_identifier =
         MakeNode<Identifier>(std::string(CONSTEXPR_TYPE_PREFIX) + name);
-    base::Optional<Identifier*> base_constexpr_type_identifier = base::nullopt;
-    if (base_identifier) {
-      base_constexpr_type_identifier = MakeNode<Identifier>(
-          std::string(CONSTEXPR_TYPE_PREFIX) + (*base_identifier)->value);
+    TypeExpression* constexpr_type_expression = MakeNode<BasicTypeExpression>(
+        std::string(CONSTEXPR_TYPE_PREFIX) + name);
+    base::Optional<TypeExpression*> base_constexpr_type_expression =
+        base::nullopt;
+    if (base_type_expression) {
+      base_constexpr_type_expression = AddConstexpr(*base_type_expression);
     }
     result.push_back(MakeNode<AbstractTypeDeclaration>(
-        constexpr_type_identifier, false, base_constexpr_type_identifier,
+        constexpr_type_identifier, false, base_constexpr_type_expression,
         constexpr_generates));
 
     TypeExpression* type_expr = nullptr;
@@ -1227,10 +1269,7 @@ base::Optional<ParseResult> MakeEnumDeclaration(
     Identifier* fromconstexpr_parameter_identifier = nullptr;
     Statement* fromconstexpr_body = nullptr;
     if (generate_nonconstexpr) {
-      DCHECK(base_identifier.has_value());
-      TypeExpression* base_type_expr = MakeNode<BasicTypeExpression>(
-          std::vector<std::string>{}, (*base_identifier)->value,
-          std::vector<TypeExpression*>{});
+      DCHECK(base_type_expression.has_value());
       type_expr = MakeNode<BasicTypeExpression>(
           std::vector<std::string>{}, name, std::vector<TypeExpression*>{});
 
@@ -1243,7 +1282,7 @@ base::Optional<ParseResult> MakeEnumDeclaration(
               std::vector<TypeExpression*>{type_expr},
               std::vector<Expression*>{MakeNode<IntrinsicCallExpression>(
                   MakeNode<Identifier>("%FromConstexpr"),
-                  std::vector<TypeExpression*>{base_type_expr},
+                  std::vector<TypeExpression*>{*base_type_expression},
                   std::vector<Expression*>{MakeNode<IdentifierExpression>(
                       std::vector<std::string>{},
                       fromconstexpr_parameter_identifier)})}));
@@ -1261,7 +1300,7 @@ base::Optional<ParseResult> MakeEnumDeclaration(
 
       entry_decls.push_back(MakeNode<AbstractTypeDeclaration>(
           MakeNode<Identifier>(entry_constexpr_type), false,
-          constexpr_type_identifier, constexpr_generates));
+          constexpr_type_expression, constexpr_generates));
 
       // namespace Enum {
       //   const kEntry0: constexpr kEntry0 constexpr 'Enum::kEntry0';
@@ -1947,7 +1986,8 @@ struct TorqueGrammar : Grammar {
       Rule({Token("builtin"), Token("("), typeList, Token(")"), Token("=>"),
             &simpleType},
            MakeFunctionTypeExpression),
-      Rule({Token("&"), &simpleType}, MakeReferenceTypeExpression)};
+      Rule({CheckIf(Token("const")), Token("&"), &simpleType},
+           MakeReferenceTypeExpression)};
 
   // Result: TypeExpression*
   Symbol type = {Rule({&simpleType}), Rule({&type, Token("|"), &simpleType},
@@ -2320,7 +2360,7 @@ struct TorqueGrammar : Grammar {
                 Sequence({Token("generates"), &externalString})),
             &optionalClassBody},
            AsSingletonVector<Declaration*, MakeClassDeclaration>()),
-      Rule({CheckIf(Token("@export")), Token("struct"), &name,
+      Rule({annotations, Token("struct"), &name,
             TryOrDefault<GenericParameters>(&genericParameters), Token("{"),
             List<Declaration*>(&method),
             List<StructFieldExpression>(&structField), Token("}")},
@@ -2331,7 +2371,7 @@ struct TorqueGrammar : Grammar {
            AsSingletonVector<Declaration*, MakeBitFieldStructDeclaration>()),
       Rule({CheckIf(Token("transient")), Token("type"), &name,
             TryOrDefault<GenericParameters>(&genericParameters),
-            Optional<Identifier*>(Sequence({Token("extends"), &name})),
+            Optional<TypeExpression*>(Sequence({Token("extends"), &type})),
             Optional<std::string>(
                 Sequence({Token("generates"), &externalString})),
             Optional<std::string>(
@@ -2361,7 +2401,7 @@ struct TorqueGrammar : Grammar {
       Rule({Token("extern"), CheckIf(Token("transitioning")), Token("runtime"),
             &name, &typeListMaybeVarArgs, &optionalReturnType, Token(";")},
            AsSingletonVector<Declaration*, MakeExternalRuntime>()),
-      Rule({CheckIf(Token("@export")), CheckIf(Token("transitioning")),
+      Rule({annotations, CheckIf(Token("transitioning")),
             Optional<std::string>(
                 Sequence({Token("operator"), &externalString})),
             Token("macro"), &name,
@@ -2381,7 +2421,7 @@ struct TorqueGrammar : Grammar {
       Rule({Token("#include"), &externalString},
            AsSingletonVector<Declaration*, MakeCppIncludeDeclaration>()),
       Rule({CheckIf(Token("extern")), Token("enum"), &name,
-            Optional<Identifier*>(Sequence({Token("extends"), &name})),
+            Optional<TypeExpression*>(Sequence({Token("extends"), &type})),
             Optional<std::string>(
                 Sequence({Token("constexpr"), &externalString})),
             Token("{"), NonemptyList<Identifier*>(&name, Token(",")),
diff --git a/deps/v8/src/torque/type-oracle.cc b/deps/v8/src/torque/type-oracle.cc
index 0e5a8a7b6b..acb998a7aa 100644
--- a/deps/v8/src/torque/type-oracle.cc
+++ b/deps/v8/src/torque/type-oracle.cc
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include "src/torque/type-oracle.h"
+#include "src/base/optional.h"
 #include "src/torque/type-visitor.h"
+#include "src/torque/types.h"
 
 namespace v8 {
 namespace internal {
@@ -68,6 +70,32 @@ Namespace* TypeOracle::CreateGenericTypeInstantiationNamespace() {
   return Get().generic_type_instantiation_namespaces_.back().get();
 }
 
+// static
+std::vector<const ClassType*> TypeOracle::GetClasses() {
+  std::vector<const ClassType*> result;
+  for (const std::unique_ptr<AggregateType>& t : Get().aggregate_types_) {
+    if (auto* class_type = ClassType::DynamicCast(t.get())) {
+      result.push_back(class_type);
+    }
+  }
+  return result;
+}
+
+base::Optional<const Type*> TypeOracle::MatchReferenceGeneric(
+    const Type* reference_type, bool* is_const) {
+  if (auto type = Type::MatchUnaryGeneric(reference_type,
+                                          GetMutableReferenceGeneric())) {
+    if (is_const) *is_const = false;
+    return type;
+  }
+  if (auto type =
+          Type::MatchUnaryGeneric(reference_type, GetConstReferenceGeneric())) {
+    if (is_const) *is_const = true;
+    return type;
+  }
+  return base::nullopt;
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/torque/type-oracle.h b/deps/v8/src/torque/type-oracle.h
index 04a78d872e..114bf043b5 100644
--- a/deps/v8/src/torque/type-oracle.h
+++ b/deps/v8/src/torque/type-oracle.h
@@ -81,11 +81,22 @@ class TypeOracle : public ContextualClass<TypeOracle> {
   static const Type* GetGenericTypeInstance(GenericType* generic_type,
                                             TypeVector arg_types);
 
-  static GenericType* GetReferenceGeneric() {
-    return Declarations::LookupUniqueGenericType(QualifiedName(
-        {TORQUE_INTERNAL_NAMESPACE_STRING}, REFERENCE_TYPE_STRING));
+  static GenericType* GetReferenceGeneric(bool is_const) {
+    return Declarations::LookupUniqueGenericType(
+        QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING},
+                      is_const ? CONST_REFERENCE_TYPE_STRING
+                               : MUTABLE_REFERENCE_TYPE_STRING));
+  }
+  static GenericType* GetConstReferenceGeneric() {
+    return GetReferenceGeneric(true);
+  }
+  static GenericType* GetMutableReferenceGeneric() {
+    return GetReferenceGeneric(false);
   }
 
+  static base::Optional<const Type*> MatchReferenceGeneric(
+      const Type* reference_type, bool* is_const = nullptr);
+
   static GenericType* GetSliceGeneric() {
     return Declarations::LookupUniqueGenericType(
         QualifiedName({TORQUE_INTERNAL_NAMESPACE_STRING}, SLICE_TYPE_STRING));
@@ -95,8 +106,20 @@ class TypeOracle : public ContextualClass<TypeOracle> {
     return Declarations::LookupGlobalUniqueGenericType(WEAK_TYPE_STRING);
   }
 
-  static const Type* GetReferenceType(const Type* referenced_type) {
-    return GetGenericTypeInstance(GetReferenceGeneric(), {referenced_type});
+  static GenericType* GetSmiTaggedGeneric() {
+    return Declarations::LookupGlobalUniqueGenericType(SMI_TAGGED_TYPE_STRING);
+  }
+
+  static const Type* GetReferenceType(const Type* referenced_type,
+                                      bool is_const) {
+    return GetGenericTypeInstance(GetReferenceGeneric(is_const),
+                                  {referenced_type});
+  }
+  static const Type* GetConstReferenceType(const Type* referenced_type) {
+    return GetReferenceType(referenced_type, true);
+  }
+  static const Type* GetMutableReferenceType(const Type* referenced_type) {
+    return GetReferenceType(referenced_type, false);
   }
 
   static const Type* GetSliceType(const Type* referenced_type) {
@@ -229,6 +252,10 @@ class TypeOracle : public ContextualClass<TypeOracle> {
     return Get().GetBuiltinType(UINT32_TYPE_STRING);
   }
 
+  static const Type* GetUint31Type() {
+    return Get().GetBuiltinType(UINT31_TYPE_STRING);
+  }
+
   static const Type* GetInt16Type() {
     return Get().GetBuiltinType(INT16_TYPE_STRING);
   }
@@ -285,6 +312,10 @@ class TypeOracle : public ContextualClass<TypeOracle> {
     return Get().GetBuiltinType(UNINITIALIZED_ITERATOR_TYPE_STRING);
   }
 
+  static const Type* GetFixedArrayBaseType() {
+    return Get().GetBuiltinType(FIXED_ARRAY_BASE_TYPE_STRING);
+  }
+
   static base::Optional<const Type*> ImplicitlyConvertableFrom(
       const Type* to, const Type* from) {
     while (from != nullptr) {
@@ -307,6 +338,10 @@ class TypeOracle : public ContextualClass<TypeOracle> {
   static const std::vector<std::unique_ptr<BitFieldStructType>>&
   GetBitFieldStructTypes();
 
+  // By construction, this list of all classes is topologically sorted w.r.t.
+  // inheritance.
+  static std::vector<const ClassType*> GetClasses();
+
   static void FinalizeAggregateTypes();
 
   static size_t FreshTypeId() { return Get().next_type_id_++; }
diff --git a/deps/v8/src/torque/type-visitor.cc b/deps/v8/src/torque/type-visitor.cc
index ce942365e7..10ed87d247 100644
--- a/deps/v8/src/torque/type-visitor.cc
+++ b/deps/v8/src/torque/type-visitor.cc
@@ -81,7 +81,7 @@ const AbstractType* TypeVisitor::ComputeType(
 
   const Type* parent_type = nullptr;
   if (decl->extends) {
-    parent_type = Declarations::LookupType(*decl->extends);
+    parent_type = TypeVisitor::ComputeType(*decl->extends);
     if (parent_type->IsUnionType()) {
       // UnionType::IsSupertypeOf requires that types can only extend from non-
       // union types in order to work correctly.
@@ -90,10 +90,6 @@ const AbstractType* TypeVisitor::ComputeType(
     }
   }
 
-  if (generates == "" && parent_type) {
-    generates = parent_type->GetGeneratedTNodeTypeName();
-  }
-
   if (decl->is_constexpr && decl->transient) {
     ReportError("cannot declare a transient type that is also constexpr");
   }
@@ -244,81 +240,83 @@ const StructType* TypeVisitor::ComputeType(
 
 const ClassType* TypeVisitor::ComputeType(
     ClassDeclaration* decl, MaybeSpecializationKey specialized_from) {
-  ClassType* new_class;
   // TODO(sigurds): Remove this hack by introducing a declarable for classes.
   const TypeAlias* alias =
       Declarations::LookupTypeAlias(QualifiedName(decl->name->value));
-  GlobalContext::RegisterClass(alias);
   DCHECK_EQ(*alias->delayed_, decl);
-  bool is_shape = decl->flags & ClassFlag::kIsShape;
-  if (is_shape && !(decl->flags & ClassFlag::kExtern)) {
-    ReportError("Shapes must be extern, add \"extern\" to the declaration.");
+  ClassFlags flags = decl->flags;
+  bool is_shape = flags & ClassFlag::kIsShape;
+  std::string generates = decl->name->value;
+  const Type* super_type = TypeVisitor::ComputeType(*decl->super);
+  if (is_shape) {
+    if (!(flags & ClassFlag::kExtern)) {
+      ReportError("Shapes must be extern, add \"extern\" to the declaration.");
+    }
+    if (flags & ClassFlag::kUndefinedLayout) {
+      ReportError("Shapes need to define their layout.");
+    }
+    const ClassType* super_class = ClassType::DynamicCast(super_type);
+    if (!super_class ||
+        !super_class->IsSubtypeOf(TypeOracle::GetJSObjectType())) {
+      Error("Shapes need to extend a subclass of ",
+            *TypeOracle::GetJSObjectType())
+          .Throw();
+    }
+    // Shapes use their super class in CSA code since they have incomplete
+    // support for type-checks on the C++ side.
+    generates = super_class->name();
   }
-  if (is_shape && decl->flags & ClassFlag::kUndefinedLayout) {
-    ReportError("Shapes need to define their layout.");
+  if (!decl->super) {
+    ReportError("Extern class must extend another type.");
   }
-  if (decl->flags & ClassFlag::kExtern) {
-    if (!decl->super) {
-      ReportError("Extern class must extend another type.");
+  if (super_type != TypeOracle::GetStrongTaggedType()) {
+    const ClassType* super_class = ClassType::DynamicCast(super_type);
+    if (!super_class) {
+      ReportError(
+          "class \"", decl->name->value,
+          "\" must extend either StrongTagged or an already declared class");
     }
-    const Type* super_type = TypeVisitor::ComputeType(*decl->super);
-    if (super_type != TypeOracle::GetStrongTaggedType()) {
-      const ClassType* super_class = ClassType::DynamicCast(super_type);
-      if (!super_class) {
-        ReportError(
-            "class \"", decl->name->value,
-            "\" must extend either StrongTagged or an already declared class");
-      }
-      if (super_class->HasUndefinedLayout() &&
-          !(decl->flags & ClassFlag::kUndefinedLayout)) {
-        Error("Class \"", decl->name->value,
-              "\" defines its layout but extends a class which does not")
-            .Position(decl->pos);
-      }
+    if (super_class->HasUndefinedLayout() &&
+        !(flags & ClassFlag::kUndefinedLayout)) {
+      Error("Class \"", decl->name->value,
+            "\" defines its layout but extends a class which does not")
+          .Position(decl->pos);
     }
-
-    std::string generates = decl->name->value;
-    if (is_shape) {
-      const ClassType* super_class = ClassType::DynamicCast(super_type);
-      if (!super_class ||
-          !super_class->IsSubtypeOf(TypeOracle::GetJSObjectType())) {
-        Error("Shapes need to extend a subclass of ",
-              *TypeOracle::GetJSObjectType())
-            .Throw();
-      }
-      // Shapes use their super class in CSA code since they have incomplete
-      // support for type-checks on the C++ side.
-      generates = super_class->name();
+    if ((flags & ClassFlag::kExport) &&
+        !(super_class->ShouldExport() || super_class->IsExtern())) {
+      Error("cannot export class ", decl->name,
+            " because superclass is neither @export or extern");
     }
+  }
+  if ((flags & ClassFlag::kGenerateBodyDescriptor ||
+       flags & ClassFlag::kExport) &&
+      flags & ClassFlag::kUndefinedLayout) {
+    Error("Class \"", decl->name->value,
+          "\" requires a layout but doesn't have one");
+  }
+  if (flags & ClassFlag::kExtern) {
     if (decl->generates) {
       bool enforce_tnode_type = true;
       generates = ComputeGeneratesType(decl->generates, enforce_tnode_type);
     }
-
-    new_class = TypeOracle::GetClassType(super_type, decl->name->value,
-                                         decl->flags, generates, decl, alias);
-  } else {
-    if (!decl->super) {
-      ReportError("Intern class ", decl->name->value,
-                  " must extend class Struct.");
-    }
-    const Type* super_type = TypeVisitor::ComputeType(*decl->super);
-    const ClassType* super_class = ClassType::DynamicCast(super_type);
-    const Type* struct_type =
-        Declarations::LookupGlobalType(QualifiedName("Struct"));
-    if (!super_class || super_class != struct_type) {
-      ReportError("Intern class ", decl->name->value,
-                  " must extend class Struct.");
+    if (flags & ClassFlag::kExport) {
+      Error("cannot export a class that is marked extern");
     }
+  } else {
     if (decl->generates) {
       ReportError("Only extern classes can specify a generated type.");
     }
-    new_class = TypeOracle::GetClassType(
-        super_type, decl->name->value,
-        decl->flags | ClassFlag::kGeneratePrint | ClassFlag::kGenerateVerify,
-        decl->name->value, decl, alias);
+    if (super_type != TypeOracle::GetStrongTaggedType()) {
+      if (flags & ClassFlag::kUndefinedLayout) {
+        Error("non-external classes must have defined layouts");
+      }
+    }
+    flags = flags | ClassFlag::kGeneratePrint | ClassFlag::kGenerateVerify |
+            ClassFlag::kGenerateBodyDescriptor;
   }
-  return new_class;
+
+  return TypeOracle::GetClassType(super_type, decl->name->value, flags,
+                                  generates, decl, alias);
 }
 
 const Type* TypeVisitor::ComputeType(TypeExpression* type_expression) {
@@ -406,33 +404,6 @@ void TypeVisitor::VisitClassFieldsAndMethods(
         ReportError("in-object properties cannot be weak");
       }
     }
-    if (!(class_declaration->flags & ClassFlag::kExtern)) {
-      if (!field_type->IsSubtypeOf(TypeOracle::GetObjectType())) {
-        ReportError(
-            "non-extern classes only support subtypes of type Object, but "
-            "found type ",
-            *field_type);
-      }
-      if (field_expression.weak) {
-        ReportError("non-extern classes do not support weak fields");
-      }
-    }
-    const StructType* struct_type = StructType::DynamicCast(field_type);
-    if (struct_type && struct_type != TypeOracle::GetFloat64OrHoleType()) {
-      for (const Field& struct_field : struct_type->fields()) {
-        if (!struct_field.name_and_type.type->IsSubtypeOf(
-                TypeOracle::GetTaggedType())) {
-          // If we ever actually need different sizes of struct fields, then we
-          // can define the packing and alignment rules. Until then, let's keep
-          // it simple. This restriction also helps keep the tagged and untagged
-          // regions separate in the class layout (see also
-          // FieldOffsetsGenerator::GetSectionFor).
-          Error(
-              "Classes do not support fields which are structs containing "
-              "untagged data.");
-        }
-      }
-    }
     base::Optional<Expression*> array_length = field_expression.index;
     const Field& field = class_type->RegisterField(
         {field_expression.name_and_type.name->pos,
@@ -445,6 +416,12 @@ void TypeVisitor::VisitClassFieldsAndMethods(
          field_expression.generate_verify});
     ResidueClass field_size = std::get<0>(field.GetFieldSizeInformation());
     if (field.index) {
+      // Validate that a value at any index in a packed array is aligned
+      // correctly, since it is possible to define a struct whose size is not a
+      // multiple of its alignment.
+      field.ValidateAlignment(class_offset +
+                              field_size * ResidueClass::Unknown());
+
       if (auto literal = NumberLiteralExpression::DynamicCast(*field.index)) {
         size_t value = static_cast<size_t>(literal->number);
         if (value != literal->number) {
diff --git a/deps/v8/src/torque/types.cc b/deps/v8/src/torque/types.cc
index a8e56ff5ee..e08716c98a 100644
--- a/deps/v8/src/torque/types.cc
+++ b/deps/v8/src/torque/types.cc
@@ -67,6 +67,20 @@ std::string Type::SimpleName() const {
   return *aliases_.begin();
 }
 
+// TODO(danno): HandlifiedCppTypeName should be used universally in Torque
+// where the C++ type of a Torque object is required.
+std::string Type::HandlifiedCppTypeName() const {
+  if (IsSubtypeOf(TypeOracle::GetSmiType())) return "int";
+  if (IsSubtypeOf(TypeOracle::GetTaggedType())) {
+    base::Optional<const ClassType*> class_type = ClassSupertype();
+    std::string type =
+        class_type ? (*class_type)->GetGeneratedTNodeTypeName() : "Object";
+    return "Handle<" + type + ">";
+  } else {
+    return ConstexprVersion()->GetGeneratedTypeName();
+  }
+}
+
 bool Type::IsSubtypeOf(const Type* supertype) const {
   if (supertype->IsTopType()) return true;
   if (IsNever()) return true;
@@ -99,6 +113,15 @@ base::Optional<const ClassType*> Type::ClassSupertype() const {
   return base::nullopt;
 }
 
+base::Optional<const StructType*> Type::StructSupertype() const {
+  for (const Type* t = this; t != nullptr; t = t->parent()) {
+    if (auto* struct_type = StructType::DynamicCast(t)) {
+      return struct_type;
+    }
+  }
+  return base::nullopt;
+}
+
 // static
 const Type* Type::CommonSupertype(const Type* a, const Type* b) {
   int diff = a->Depth() - b->Depth();
@@ -147,6 +170,7 @@ std::string Type::GetGeneratedTNodeTypeName() const {
 }
 
 std::string AbstractType::GetGeneratedTNodeTypeNameImpl() const {
+  if (generated_type_.empty()) return parent()->GetGeneratedTNodeTypeName();
   return generated_type_;
 }
 
@@ -371,10 +395,31 @@ size_t StructType::PackedSize() const {
   return result;
 }
 
+StructType::Classification StructType::ClassifyContents() const {
+  Classification result = ClassificationFlag::kEmpty;
+  for (const Field& struct_field : fields()) {
+    const Type* field_type = struct_field.name_and_type.type;
+    if (field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+      result |= ClassificationFlag::kTagged;
+    } else if (auto field_as_struct = field_type->StructSupertype()) {
+      result |= (*field_as_struct)->ClassifyContents();
+    } else {
+      result |= ClassificationFlag::kUntagged;
+    }
+  }
+  return result;
+}
+
 // static
 std::string Type::ComputeName(const std::string& basename,
                               MaybeSpecializationKey specialized_from) {
   if (!specialized_from) return basename;
+  if (specialized_from->generic == TypeOracle::GetConstReferenceGeneric()) {
+    return torque::ToString("const &", *specialized_from->specialized_types[0]);
+  }
+  if (specialized_from->generic == TypeOracle::GetMutableReferenceGeneric()) {
+    return torque::ToString("&", *specialized_from->specialized_types[0]);
+  }
   std::stringstream s;
   s << basename << "<";
   bool first = true;
@@ -501,47 +546,76 @@ void ClassType::GenerateAccessors() {
   // For each field, construct AST snippets that implement a CSA accessor
   // function. The implementation iterator will turn the snippets into code.
   for (auto& field : fields_) {
-    if (field.index || field.name_and_type.type == TypeOracle::GetVoidType()) {
+    if (field.name_and_type.type == TypeOracle::GetVoidType()) {
       continue;
     }
     CurrentSourcePosition::Scope position_activator(field.pos);
+
     IdentifierExpression* parameter =
         MakeNode<IdentifierExpression>(MakeNode<Identifier>(std::string{"o"}));
+    IdentifierExpression* index =
+        MakeNode<IdentifierExpression>(MakeNode<Identifier>(std::string{"i"}));
 
     // Load accessor
     std::string camel_field_name = CamelifyString(field.name_and_type.name);
     std::string load_macro_name = "Load" + this->name() + camel_field_name;
+
+    // For now, only generate indexed accessors for simple types
+    if (field.index.has_value() && field.name_and_type.type->IsStructType()) {
+      continue;
+    }
+
     Signature load_signature;
     load_signature.parameter_names.push_back(MakeNode<Identifier>("o"));
     load_signature.parameter_types.types.push_back(this);
+    if (field.index) {
+      load_signature.parameter_names.push_back(MakeNode<Identifier>("i"));
+      load_signature.parameter_types.types.push_back(
+          TypeOracle::GetIntPtrType());
+    }
     load_signature.parameter_types.var_args = false;
     load_signature.return_type = field.name_and_type.type;
-    Statement* load_body =
-        MakeNode<ReturnStatement>(MakeNode<FieldAccessExpression>(
-            parameter, MakeNode<Identifier>(field.name_and_type.name)));
+
+    Expression* load_expression = MakeNode<FieldAccessExpression>(
+        parameter, MakeNode<Identifier>(field.name_and_type.name));
+    if (field.index) {
+      load_expression =
+          MakeNode<ElementAccessExpression>(load_expression, index);
+    }
+    Statement* load_body = MakeNode<ReturnStatement>(load_expression);
     Declarations::DeclareMacro(load_macro_name, true, base::nullopt,
                                load_signature, load_body, base::nullopt);
 
     // Store accessor
-    IdentifierExpression* value = MakeNode<IdentifierExpression>(
-        std::vector<std::string>{}, MakeNode<Identifier>(std::string{"v"}));
-    std::string store_macro_name = "Store" + this->name() + camel_field_name;
-    Signature store_signature;
-    store_signature.parameter_names.push_back(MakeNode<Identifier>("o"));
-    store_signature.parameter_names.push_back(MakeNode<Identifier>("v"));
-    store_signature.parameter_types.types.push_back(this);
-    store_signature.parameter_types.types.push_back(field.name_and_type.type);
-    store_signature.parameter_types.var_args = false;
-    // TODO(danno): Store macros probably should return their value argument
-    store_signature.return_type = TypeOracle::GetVoidType();
-    Statement* store_body =
-        MakeNode<ExpressionStatement>(MakeNode<AssignmentExpression>(
-            MakeNode<FieldAccessExpression>(
-                parameter, MakeNode<Identifier>(field.name_and_type.name)),
-            value));
-    Declarations::DeclareMacro(store_macro_name, true, base::nullopt,
-                               store_signature, store_body, base::nullopt,
-                               false);
+    if (!field.const_qualified) {
+      IdentifierExpression* value = MakeNode<IdentifierExpression>(
+          std::vector<std::string>{}, MakeNode<Identifier>(std::string{"v"}));
+      std::string store_macro_name = "Store" + this->name() + camel_field_name;
+      Signature store_signature;
+      store_signature.parameter_names.push_back(MakeNode<Identifier>("o"));
+      store_signature.parameter_types.types.push_back(this);
+      if (field.index) {
+        store_signature.parameter_names.push_back(MakeNode<Identifier>("i"));
+        store_signature.parameter_types.types.push_back(
+            TypeOracle::GetIntPtrType());
+      }
+      store_signature.parameter_names.push_back(MakeNode<Identifier>("v"));
+      store_signature.parameter_types.types.push_back(field.name_and_type.type);
+      store_signature.parameter_types.var_args = false;
+      // TODO(danno): Store macros probably should return their value argument
+      store_signature.return_type = TypeOracle::GetVoidType();
+      Expression* store_expression = MakeNode<FieldAccessExpression>(
+          parameter, MakeNode<Identifier>(field.name_and_type.name));
+      if (field.index) {
+        store_expression =
+            MakeNode<ElementAccessExpression>(store_expression, index);
+      }
+      Statement* store_body = MakeNode<ExpressionStatement>(
+          MakeNode<AssignmentExpression>(store_expression, value));
+      Declarations::DeclareMacro(store_macro_name, true, base::nullopt,
+                                 store_signature, store_body, base::nullopt,
+                                 false);
+    }
   }
 }
 
@@ -658,7 +732,7 @@ VisitResult ProjectStructField(VisitResult structure,
   BottomOffset begin = structure.stack_range().begin();
 
   // Check constructor this super classes for fields.
-  const StructType* type = StructType::cast(structure.type());
+  const StructType* type = *structure.type()->StructSupertype();
   auto& fields = type->fields();
   for (auto& field : fields) {
     BottomOffset end = begin + LoweredSlotCount(field.name_and_type.type);
@@ -677,8 +751,8 @@ void AppendLoweredTypes(const Type* type, std::vector<const Type*>* result) {
   DCHECK_NE(type, TypeOracle::GetNeverType());
   if (type->IsConstexpr()) return;
   if (type == TypeOracle::GetVoidType()) return;
-  if (auto* s = StructType::DynamicCast(type)) {
-    for (const Field& field : s->fields()) {
+  if (base::Optional<const StructType*> s = type->StructSupertype()) {
+    for (const Field& field : (*s)->fields()) {
       AppendLoweredTypes(field.name_and_type.type, result);
     }
   } else {
@@ -781,9 +855,9 @@ size_t StructType::AlignmentLog2() const {
 
 void Field::ValidateAlignment(ResidueClass at_offset) const {
   const Type* type = name_and_type.type;
-  const StructType* struct_type = StructType::DynamicCast(type);
+  base::Optional<const StructType*> struct_type = type->StructSupertype();
   if (struct_type && struct_type != TypeOracle::GetFloat64OrHoleType()) {
-    for (const Field& field : struct_type->fields()) {
+    for (const Field& field : (*struct_type)->fields()) {
       field.ValidateAlignment(at_offset);
       size_t field_size = std::get<0>(field.GetFieldSizeInformation());
       at_offset += field_size;
@@ -837,12 +911,12 @@ base::Optional<std::tuple<size_t, std::string>> SizeOf(const Type* type) {
   } else if (type->IsSubtypeOf(TypeOracle::GetUIntPtrType())) {
     size = TargetArchitecture::RawPtrSize();
     size_string = "kIntptrSize";
-  } else if (const StructType* struct_type = StructType::DynamicCast(type)) {
+  } else if (auto struct_type = type->StructSupertype()) {
     if (type == TypeOracle::GetFloat64OrHoleType()) {
       size = kDoubleSize;
       size_string = "kDoubleSize";
     } else {
-      size = struct_type->PackedSize();
+      size = (*struct_type)->PackedSize();
       size_string = std::to_string(size);
     }
   } else {
@@ -853,6 +927,7 @@ base::Optional<std::tuple<size_t, std::string>> SizeOf(const Type* type) {
 
 bool IsAnyUnsignedInteger(const Type* type) {
   return type == TypeOracle::GetUint32Type() ||
+         type == TypeOracle::GetUint31Type() ||
          type == TypeOracle::GetUint16Type() ||
          type == TypeOracle::GetUint8Type() ||
          type == TypeOracle::GetUIntPtrType();
diff --git a/deps/v8/src/torque/types.h b/deps/v8/src/torque/types.h
index 19b5cdd635..b60879ce85 100644
--- a/deps/v8/src/torque/types.h
+++ b/deps/v8/src/torque/types.h
@@ -113,6 +113,8 @@ class V8_EXPORT_PRIVATE Type : public TypeBase {
   // Used for naming generated code.
   virtual std::string SimpleName() const;
 
+  std::string HandlifiedCppTypeName() const;
+
   const Type* parent() const { return parent_; }
   bool IsVoid() const { return IsAbstractName(VOID_TYPE_STRING); }
   bool IsNever() const { return IsAbstractName(NEVER_TYPE_STRING); }
@@ -131,6 +133,7 @@ class V8_EXPORT_PRIVATE Type : public TypeBase {
   virtual const Type* NonConstexprVersion() const { return this; }
   std::string GetConstexprGeneratedTypeName() const;
   base::Optional<const ClassType*> ClassSupertype() const;
+  base::Optional<const StructType*> StructSupertype() const;
   virtual std::vector<RuntimeType> GetRuntimeTypes() const { return {}; }
   static const Type* CommonSupertype(const Type* a, const Type* b);
   void AddAlias(std::string alias) const { aliases_.insert(std::move(alias)); }
@@ -256,6 +259,9 @@ class AbstractType final : public Type {
   const std::string& name() const { return name_; }
   std::string ToExplicitString() const override { return name(); }
   std::string GetGeneratedTypeNameImpl() const override {
+    if (generated_type_.empty()) {
+      return parent()->GetGeneratedTypeName();
+    }
     return IsConstexpr() ? generated_type_ : "TNode<" + generated_type_ + ">";
   }
   std::string GetGeneratedTNodeTypeNameImpl() const override;
@@ -575,6 +581,17 @@ class StructType final : public AggregateType {
 
   size_t AlignmentLog2() const override;
 
+  enum class ClassificationFlag {
+    kEmpty = 0,
+    kTagged = 1 << 0,
+    kUntagged = 1 << 1,
+    kMixed = kTagged | kUntagged,
+  };
+  using Classification = base::Flags<ClassificationFlag>;
+
+  // Classifies a struct as containing tagged data, untagged data, or both.
+  Classification ClassifyContents() const;
+
  private:
   friend class TypeOracle;
   StructType(Namespace* nspace, const StructDeclaration* decl,
@@ -600,12 +617,15 @@ class ClassType final : public AggregateType {
   std::string GetGeneratedTNodeTypeNameImpl() const override;
   bool IsExtern() const { return flags_ & ClassFlag::kExtern; }
   bool ShouldGeneratePrint() const {
-    return (flags_ & ClassFlag::kGeneratePrint || !IsExtern()) &&
-           !HasUndefinedLayout();
+    return !IsExtern() ||
+           ((flags_ & ClassFlag::kGeneratePrint) && !HasUndefinedLayout());
   }
   bool ShouldGenerateVerify() const {
-    return (flags_ & ClassFlag::kGenerateVerify || !IsExtern()) &&
-           !HasUndefinedLayout() && !IsShape();
+    return !IsExtern() || ((flags_ & ClassFlag::kGenerateVerify) &&
+                           (!HasUndefinedLayout() && !IsShape()));
+  }
+  bool ShouldGenerateBodyDescriptor() const {
+    return flags_ & ClassFlag::kGenerateBodyDescriptor || !IsExtern();
   }
   bool IsTransient() const override { return flags_ & ClassFlag::kTransient; }
   bool IsAbstract() const { return flags_ & ClassFlag::kAbstract; }
@@ -613,8 +633,10 @@ class ClassType final : public AggregateType {
     return flags_ & ClassFlag::kHasSameInstanceTypeAsParent;
   }
   bool GenerateCppClassDefinitions() const {
-    return flags_ & ClassFlag::kGenerateCppClassDefinitions || !IsExtern();
+    return flags_ & ClassFlag::kGenerateCppClassDefinitions || !IsExtern() ||
+           ShouldGenerateBodyDescriptor();
   }
+  bool ShouldExport() const { return flags_ & ClassFlag::kExport; }
   bool IsShape() const { return flags_ & ClassFlag::kIsShape; }
   bool HasStaticSize() const;
   bool HasIndexedField() const override;
diff --git a/deps/v8/src/torque/utils.cc b/deps/v8/src/torque/utils.cc
index 9c04d73d1b..312adcfb24 100644
--- a/deps/v8/src/torque/utils.cc
+++ b/deps/v8/src/torque/utils.cc
@@ -222,7 +222,7 @@ bool IsUpperCamelCase(const std::string& s) {
   if (s.empty()) return false;
   size_t start = 0;
   if (s[0] == '_') start = 1;
-  return isupper(s[start]) && !ContainsUnderscore(s.substr(1));
+  return isupper(s[start]);
 }
 
 bool IsSnakeCase(const std::string& s) {
diff --git a/deps/v8/src/torque/utils.h b/deps/v8/src/torque/utils.h
index 448e7da7fb..1c5b3079f5 100644
--- a/deps/v8/src/torque/utils.h
+++ b/deps/v8/src/torque/utils.h
@@ -6,10 +6,10 @@
 #define V8_TORQUE_UTILS_H_
 
 #include <ostream>
+#include <queue>
 #include <streambuf>
 #include <string>
 #include <unordered_set>
-#include <vector>
 
 #include "src/base/functional.h"
 #include "src/base/optional.h"
@@ -172,6 +172,13 @@ void PrintCommaSeparatedList(std::ostream& os, const T& list) {
 
 struct BottomOffset {
   size_t offset;
+  BottomOffset(std::nullptr_t zero = 0)  // NOLINT(runtime/explicit)
+      : offset(0) {}
+  explicit BottomOffset(std::size_t offset) : offset(offset) {}
+  BottomOffset& operator=(std::size_t offset) {
+    this->offset = offset;
+    return *this;
+  }
   BottomOffset& operator++() {
     ++offset;
     return *this;
@@ -488,6 +495,36 @@ class ResidueClass {
   static const size_t kMaxModulusLog2 = 8 * sizeof(size_t);
 };
 
+template <typename T>
+class Worklist {
+ public:
+  bool IsEmpty() const {
+    DCHECK_EQ(queue_.size(), contained_.size());
+    return queue_.empty();
+  }
+
+  bool Enqueue(T value) {
+    if (contained_.find(value) != contained_.end()) return false;
+    queue_.push(value);
+    contained_.insert(value);
+    DCHECK_EQ(queue_.size(), contained_.size());
+    return true;
+  }
+
+  T Dequeue() {
+    DCHECK(!IsEmpty());
+    T value = queue_.front();
+    queue_.pop();
+    contained_.erase(value);
+    DCHECK_EQ(queue_.size(), contained_.size());
+    return value;
+  }
+
+ private:
+  std::queue<T> queue_;
+  std::unordered_set<T> contained_;
+};
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/utils/vector.h b/deps/v8/src/utils/vector.h
index 5c106cc0c8..71dadc6c0e 100644
--- a/deps/v8/src/utils/vector.h
+++ b/deps/v8/src/utils/vector.h
@@ -9,6 +9,7 @@
 #include <cstring>
 #include <iterator>
 #include <memory>
+#include <type_traits>
 
 #include "src/common/checks.h"
 #include "src/common/globals.h"
@@ -71,6 +72,9 @@ class Vector {
   // Returns a pointer to the start of the data in the vector.
   constexpr T* begin() const { return start_; }
 
+  // For consistency with other containers, do also provide a {data} accessor.
+  constexpr T* data() const { return start_; }
+
   // Returns a pointer past the end of the data in the vector.
   constexpr T* end() const { return start_ + length_; }
 
@@ -113,6 +117,14 @@ class Vector {
 
   template <typename S>
   static constexpr Vector<T> cast(Vector<S> input) {
+    // Casting is potentially dangerous, so be really restrictive here. This
+    // might be lifted once we have use cases for that.
+    STATIC_ASSERT(std::is_pod<S>::value);
+    STATIC_ASSERT(std::is_pod<T>::value);
+#if V8_HAS_CXX14_CONSTEXPR
+    DCHECK_EQ(0, (input.length() * sizeof(S)) % sizeof(T));
+    DCHECK_EQ(0, reinterpret_cast<uintptr_t>(input.begin()) % alignof(T));
+#endif
     return Vector<T>(reinterpret_cast<T*>(input.begin()),
                      input.length() * sizeof(S) / sizeof(T));
   }
diff --git a/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h b/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
index 9b7f8696a1..fe921c6406 100644
--- a/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
+++ b/deps/v8/src/wasm/baseline/arm/liftoff-assembler-arm.h
@@ -264,7 +264,7 @@ void LiftoffAssembler::PatchPrepareStackFrame(int offset, int frame_size) {
     patching_assembler.PadWithNops();
 
     // Now generate the OOL code.
-    AllocateStackSpace(bytes);
+    AllocateStackSpace(frame_size);
     // Jump back to the start of the function (from {pc_offset()} to {offset +
     // liftoff::kPatchInstructionsRequired * kInstrSize}).
     int func_start_offset =
@@ -287,17 +287,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -307,11 +307,11 @@ bool LiftoffAssembler::NeedsAlignment(ValueType type) {
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       TurboAssembler::Move(reg.gp(), Operand(value.to_i32(), rmode));
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       DCHECK(RelocInfo::IsNone(rmode));
       int32_t low_word = value.to_i64();
       int32_t high_word = value.to_i64() >> 32;
@@ -319,10 +319,10 @@ void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
       TurboAssembler::Move(reg.high_gp(), Operand(high_word));
       break;
     }
-    case kWasmF32:
+    case ValueType::kF32:
       vmov(liftoff::GetFloatRegister(reg.fp()), value.to_f32_boxed());
       break;
-    case kWasmF64: {
+    case ValueType::kF64: {
       Register extra_scratch = GetUnusedRegister(kGpReg).gp();
       vmov(reg.fp(), Double(value.to_f64_boxed().get_scalar()), extra_scratch);
       break;
@@ -582,25 +582,47 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { dmb(ISH); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
   int32_t offset = (caller_slot_idx + 1) * kSystemPointerSize;
   MemOperand src(fp, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       ldr(dst.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       ldr(dst.low_gp(), src);
       ldr(dst.high_gp(), MemOperand(fp, offset + kSystemPointerSize));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       vldr(liftoff::GetFloatRegister(dst.fp()), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       vldr(dst.fp(), src);
       break;
+    case ValueType::kS128: {
+      UseScratchRegisterScope temps(this);
+      Register addr = liftoff::CalculateActualAddress(this, &temps, src.rn(),
+                                                      no_reg, src.offset());
+      vld1(Neon8, NeonListOperand(dst.low_fp(), 2), NeonMemOperand(addr));
+      break;
+    }
     default:
       UNREACHABLE();
   }
@@ -636,21 +658,21 @@ void LiftoffAssembler::Move(DoubleRegister dst, DoubleRegister src,
 void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
   RecordUsedSpillOffset(offset);
   MemOperand dst = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       str(reg.gp(), dst);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       str(reg.low_gp(), liftoff::GetHalfStackSlot(offset, kLowWord));
       str(reg.high_gp(), liftoff::GetHalfStackSlot(offset, kHighWord));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       vstr(liftoff::GetFloatRegister(reg.fp()), dst);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       vstr(reg.fp(), dst);
       break;
-    case kWasmS128: {
+    case ValueType::kS128: {
       UseScratchRegisterScope temps(this);
       Register addr = liftoff::CalculateActualAddress(this, &temps, dst.rn(),
                                                       no_reg, dst.offset());
@@ -674,12 +696,12 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
   } else {
     src = temps.Acquire();
   }
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       mov(src, Operand(value.to_i32()));
       str(src, dst);
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       int32_t low_word = value.to_i64();
       mov(src, Operand(low_word));
       str(src, liftoff::GetHalfStackSlot(offset, kLowWord));
@@ -695,21 +717,21 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
 }
 
 void LiftoffAssembler::Fill(LiftoffRegister reg, int offset, ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       ldr(reg.gp(), liftoff::GetStackSlot(offset));
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       ldr(reg.low_gp(), liftoff::GetHalfStackSlot(offset, kLowWord));
       ldr(reg.high_gp(), liftoff::GetHalfStackSlot(offset, kHighWord));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       vldr(liftoff::GetFloatRegister(reg.fp()), liftoff::GetStackSlot(offset));
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       vldr(reg.fp(), liftoff::GetStackSlot(offset));
       break;
-    case kWasmS128: {
+    case ValueType::kS128: {
       // Get memory address of slot to fill from.
       MemOperand slot = liftoff::GetStackSlot(offset);
       UseScratchRegisterScope temps(this);
@@ -1531,11 +1553,266 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   }
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  TurboAssembler::Move(dst.low_fp(), src.fp());
+  TurboAssembler::Move(dst.high_fp(), src.fp());
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  ExtractLane(dst.fp(), liftoff::GetSimd128Register(lhs.low_fp()),
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  ReplaceLane(liftoff::GetSimd128Register(dst.low_fp()),
+              liftoff::GetSimd128Register(src1.low_fp()), src2.fp(),
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(dst.low_fp(), lhs.low_fp(), rhs.low_fp());
+  vadd(dst.high_fp(), lhs.high_fp(), rhs.high_fp());
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(dst.low_fp(), lhs.low_fp(), rhs.low_fp());
+  vsub(dst.high_fp(), lhs.high_fp(), rhs.high_fp());
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "f64x2mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   vdup(Neon32, liftoff::GetSimd128Register(dst.low_fp()), src.fp(), 0);
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  ExtractLane(liftoff::GetFloatRegister(dst.fp()),
+              liftoff::GetSimd128Register(lhs.low_fp()), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  ReplaceLane(liftoff::GetSimd128Register(dst.low_fp()),
+              liftoff::GetSimd128Register(src1.low_fp()),
+              liftoff::GetFloatRegister(src2.fp()), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "f32x4mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Simd128Register dst_simd = liftoff::GetSimd128Register(dst.low_fp());
+  vdup(Neon32, dst_simd, src.low_gp());
+  ReplaceLane(dst_simd, dst_simd, src.high_gp(), NeonS32, 1);
+  ReplaceLane(dst_simd, dst_simd, src.high_gp(), NeonS32, 3);
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  ExtractLane(dst.low_gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonS32,
+              imm_lane_idx * 2);
+  ExtractLane(dst.high_gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonS32,
+              imm_lane_idx * 2 + 1);
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  Simd128Register dst_simd = liftoff::GetSimd128Register(dst.low_fp());
+  Simd128Register src1_simd = liftoff::GetSimd128Register(src1.low_fp());
+  ReplaceLane(dst_simd, src1_simd, src2.low_gp(), NeonS32, imm_lane_idx * 2);
+  ReplaceLane(dst_simd, dst_simd, src2.high_gp(), NeonS32,
+              imm_lane_idx * 2 + 1);
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(Neon64, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(Neon64, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i64x2mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  vdup(Neon32, liftoff::GetSimd128Register(dst.low_fp()), src.gp());
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  ExtractLane(dst.gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonS32,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  ReplaceLane(liftoff::GetSimd128Register(dst.low_fp()),
+              liftoff::GetSimd128Register(src1.low_fp()), src2.gp(), NeonS32,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(Neon32, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(Neon32, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i32x4mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  vdup(Neon16, liftoff::GetSimd128Register(dst.low_fp()), src.gp());
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(Neon16, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(Neon16, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i16x8mul");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  ExtractLane(dst.gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonU16,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  ExtractLane(dst.gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonS16,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  ReplaceLane(liftoff::GetSimd128Register(dst.low_fp()),
+              liftoff::GetSimd128Register(src1.low_fp()), src2.gp(), NeonS16,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  vdup(Neon8, liftoff::GetSimd128Register(dst.low_fp()), src.gp());
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  ExtractLane(dst.gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonU8,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  ExtractLane(dst.gp(), liftoff::GetSimd128Register(lhs.low_fp()), NeonS8,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  ReplaceLane(liftoff::GetSimd128Register(dst.low_fp()),
+              liftoff::GetSimd128Register(src1.low_fp()), src2.gp(), NeonS8,
+              imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vadd(Neon8, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  vsub(Neon8, liftoff::GetSimd128Register(dst.low_fp()),
+       liftoff::GetSimd128Register(lhs.low_fp()),
+       liftoff::GetSimd128Register(rhs.low_fp()));
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i8x16mul");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   ldr(limit_address, MemOperand(limit_address));
   cmp(sp, limit_address);
@@ -1603,7 +1880,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   Ret();
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1616,25 +1893,25 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
 
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
-    switch (param_type) {
-      case kWasmI32:
+    switch (param_type.kind()) {
+      case ValueType::kI32:
         str(args->gp(), MemOperand(sp, arg_bytes));
         break;
-      case kWasmI64:
+      case ValueType::kI64:
         str(args->low_gp(), MemOperand(sp, arg_bytes));
         str(args->high_gp(), MemOperand(sp, arg_bytes + kSystemPointerSize));
         break;
-      case kWasmF32:
+      case ValueType::kF32:
         vstr(liftoff::GetFloatRegister(args->fp()), MemOperand(sp, arg_bytes));
         break;
-      case kWasmF64:
+      case ValueType::kF64:
         vstr(args->fp(), MemOperand(sp, arg_bytes));
         break;
       default:
         UNREACHABLE();
     }
     args++;
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -1659,18 +1936,18 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
 
   // Load potential output value from the buffer on the stack.
   if (out_argument_type != kWasmStmt) {
-    switch (out_argument_type) {
-      case kWasmI32:
+    switch (out_argument_type.kind()) {
+      case ValueType::kI32:
         ldr(result_reg->gp(), MemOperand(sp));
         break;
-      case kWasmI64:
+      case ValueType::kI64:
         ldr(result_reg->low_gp(), MemOperand(sp));
         ldr(result_reg->high_gp(), MemOperand(sp, kSystemPointerSize));
         break;
-      case kWasmF32:
+      case ValueType::kF32:
         vldr(liftoff::GetFloatRegister(result_reg->fp()), MemOperand(sp));
         break;
-      case kWasmF64:
+      case ValueType::kF64:
         vldr(result_reg->fp(), MemOperand(sp));
         break;
       default:
@@ -1684,7 +1961,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   Call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   DCHECK(target != no_reg);
@@ -1706,52 +1983,63 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   add(sp, sp, Operand(size));
 }
 
-void LiftoffAssembler::DebugBreak() { stop(); }
-
 void LiftoffStackSlots::Construct() {
   for (auto& slot : slots_) {
     const LiftoffAssembler::VarState& src = slot.src_;
     switch (src.loc()) {
       case LiftoffAssembler::VarState::kStack: {
-        switch (src.type()) {
+        switch (src.type().kind()) {
           // i32 and i64 can be treated as similar cases, i64 being previously
           // split into two i32 registers
-          case kWasmI32:
-          case kWasmI64:
-          case kWasmF32: {
+          case ValueType::kI32:
+          case ValueType::kI64:
+          case ValueType::kF32: {
             UseScratchRegisterScope temps(asm_);
             Register scratch = temps.Acquire();
             asm_->ldr(scratch,
                       liftoff::GetHalfStackSlot(slot.src_offset_, slot.half_));
             asm_->Push(scratch);
           } break;
-          case kWasmF64: {
+          case ValueType::kF64: {
             UseScratchRegisterScope temps(asm_);
             DwVfpRegister scratch = temps.AcquireD();
             asm_->vldr(scratch, liftoff::GetStackSlot(slot.src_offset_));
             asm_->vpush(scratch);
           } break;
+          case ValueType::kS128: {
+            MemOperand mem_op = liftoff::GetStackSlot(slot.src_offset_);
+            UseScratchRegisterScope temps(asm_);
+            Register addr = liftoff::CalculateActualAddress(
+                asm_, &temps, mem_op.rn(), no_reg, mem_op.offset());
+            QwNeonRegister scratch = temps.AcquireQ();
+            asm_->vld1(Neon8, NeonListOperand(scratch), NeonMemOperand(addr));
+            asm_->vpush(scratch);
+            break;
+          }
           default:
             UNREACHABLE();
         }
         break;
       }
       case LiftoffAssembler::VarState::kRegister:
-        switch (src.type()) {
-          case kWasmI64: {
+        switch (src.type().kind()) {
+          case ValueType::kI64: {
             LiftoffRegister reg =
                 slot.half_ == kLowWord ? src.reg().low() : src.reg().high();
             asm_->push(reg.gp());
           } break;
-          case kWasmI32:
+          case ValueType::kI32:
             asm_->push(src.reg().gp());
             break;
-          case kWasmF32:
+          case ValueType::kF32:
             asm_->vpush(liftoff::GetFloatRegister(src.reg().fp()));
             break;
-          case kWasmF64:
+          case ValueType::kF64:
             asm_->vpush(src.reg().fp());
             break;
+          case ValueType::kS128:
+            asm_->vpush(liftoff::GetSimd128Register(src.reg().low_fp()));
+            break;
           default:
             UNREACHABLE();
         }
diff --git a/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h b/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
index 9697fabf9f..bcf78184b1 100644
--- a/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
+++ b/deps/v8/src/wasm/baseline/arm64/liftoff-assembler-arm64.h
@@ -46,16 +46,16 @@ inline MemOperand GetStackSlot(int offset) { return MemOperand(fp, -offset); }
 inline MemOperand GetInstanceOperand() { return GetStackSlot(kInstanceOffset); }
 
 inline CPURegister GetRegFromType(const LiftoffRegister& reg, ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       return reg.gp().W();
-    case kWasmI64:
+    case ValueType::kI64:
       return reg.gp().X();
-    case kWasmF32:
+    case ValueType::kF32:
       return reg.fp().S();
-    case kWasmF64:
+    case ValueType::kF64:
       return reg.fp().D();
-    case kWasmS128:
+    case ValueType::kS128:
       return reg.fp().Q();
     default:
       UNREACHABLE();
@@ -74,14 +74,14 @@ inline CPURegList PadVRegList(RegList list) {
 
 inline CPURegister AcquireByType(UseScratchRegisterScope* temps,
                                  ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       return temps->AcquireW();
-    case kWasmI64:
+    case ValueType::kI64:
       return temps->AcquireX();
-    case kWasmF32:
+    case ValueType::kF32:
       return temps->AcquireS();
-    case kWasmF64:
+    case ValueType::kF64:
       return temps->AcquireD();
     default:
       UNREACHABLE();
@@ -174,17 +174,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
   // TODO(zhin): Unaligned access typically take additional cycles, we should do
   // some performance testing to see how big an effect it will take.
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -194,17 +194,17 @@ bool LiftoffAssembler::NeedsAlignment(ValueType type) {
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       Mov(reg.gp().W(), Immediate(value.to_i32(), rmode));
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       Mov(reg.gp().X(), Immediate(value.to_i64(), rmode));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       Fmov(reg.fp().S(), value.to_f32_boxed().get_scalar());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       Fmov(reg.fp().D(), value.to_f64_boxed().get_scalar());
       break;
     default:
@@ -382,6 +382,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { Dmb(InnerShareable, BarrierAll); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -429,8 +444,8 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
   MemOperand dst = liftoff::GetStackSlot(offset);
   UseScratchRegisterScope temps(this);
   CPURegister src = CPURegister::no_reg();
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       if (value.to_i32() == 0) {
         src = wzr;
       } else {
@@ -438,7 +453,7 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
         Mov(src.W(), value.to_i32());
       }
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       if (value.to_i64() == 0) {
         src = xzr;
       } else {
@@ -1003,15 +1018,15 @@ void LiftoffAssembler::emit_jump(Register target) { Br(target); }
 void LiftoffAssembler::emit_cond_jump(Condition cond, Label* label,
                                       ValueType type, Register lhs,
                                       Register rhs) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       if (rhs.is_valid()) {
         Cmp(lhs.W(), rhs.W());
       } else {
         Cmp(lhs.W(), wzr);
       }
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       if (rhs.is_valid()) {
         Cmp(lhs.X(), rhs.X());
       } else {
@@ -1069,11 +1084,234 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   }
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Dup(dst.fp().V2D(), src.fp().D(), 0);
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Mov(dst.fp().D(), lhs.fp().V2D(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V2D(), src1.fp().V2D());
+  }
+  Mov(dst.fp().V2D(), imm_lane_idx, src2.fp().V2D(), 0);
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Fadd(dst.fp().V2D(), lhs.fp().V2D(), rhs.fp().V2D());
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Fsub(dst.fp().V2D(), lhs.fp().V2D(), rhs.fp().V2D());
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "f64x2mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   Dup(dst.fp().V4S(), src.fp().S(), 0);
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Mov(dst.fp().S(), lhs.fp().V4S(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V4S(), src1.fp().V4S());
+  }
+  Mov(dst.fp().V4S(), imm_lane_idx, src2.fp().V4S(), 0);
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Fadd(dst.fp().V4S(), lhs.fp().V4S(), rhs.fp().V4S());
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Fsub(dst.fp().V4S(), lhs.fp().V4S(), rhs.fp().V4S());
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "f32x4mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Dup(dst.fp().V2D(), src.gp().X());
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Mov(dst.gp().X(), lhs.fp().V2D(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V2D(), src1.fp().V2D());
+  }
+  Mov(dst.fp().V2D(), imm_lane_idx, src2.gp().X());
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Add(dst.fp().V2D(), lhs.fp().V2D(), rhs.fp().V2D());
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Sub(dst.fp().V2D(), lhs.fp().V2D(), rhs.fp().V2D());
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i64x2mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Dup(dst.fp().V4S(), src.gp().W());
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Mov(dst.gp().W(), lhs.fp().V4S(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V4S(), src1.fp().V4S());
+  }
+  Mov(dst.fp().V4S(), imm_lane_idx, src2.gp().W());
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Add(dst.fp().V4S(), lhs.fp().V4S(), rhs.fp().V4S());
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Sub(dst.fp().V4S(), lhs.fp().V4S(), rhs.fp().V4S());
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i32x4mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Dup(dst.fp().V8H(), src.gp().W());
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Umov(dst.gp().W(), lhs.fp().V8H(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Smov(dst.gp().W(), lhs.fp().V8H(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V8H(), src1.fp().V8H());
+  }
+  Mov(dst.fp().V8H(), imm_lane_idx, src2.gp().W());
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Add(dst.fp().V8H(), lhs.fp().V8H(), rhs.fp().V8H());
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Sub(dst.fp().V8H(), lhs.fp().V8H(), rhs.fp().V8H());
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i16x8mul");
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Dup(dst.fp().V16B(), src.gp().W());
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Umov(dst.gp().W(), lhs.fp().V16B(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Smov(dst.gp().W(), lhs.fp().V16B(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (dst != src1) {
+    Mov(dst.fp().V16B(), src1.fp().V16B());
+  }
+  Mov(dst.fp().V16B(), imm_lane_idx, src2.gp().W());
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Add(dst.fp().V16B(), lhs.fp().V16B(), rhs.fp().V16B());
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  Sub(dst.fp().V16B(), lhs.fp().V16B(), rhs.fp().V16B());
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kSimd, "i8x16mul");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   Ldr(limit_address, MemOperand(limit_address));
   Cmp(sp, limit_address);
@@ -1103,7 +1341,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   Ret();
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1116,7 +1354,7 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
     Poke(liftoff::GetRegFromType(*args++, param_type), arg_bytes);
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -1150,7 +1388,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   Call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   // For Arm64, we have more cache registers than wasm parameters. That means
@@ -1178,15 +1416,16 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   Drop(size, 1);
 }
 
-void LiftoffAssembler::DebugBreak() { debug("DebugBreak", 0, BREAK); }
-
 void LiftoffStackSlots::Construct() {
-  size_t slot_count = slots_.size();
+  size_t num_slots = 0;
+  for (auto& slot : slots_) {
+    num_slots += slot.src_.type() == kWasmS128 ? 2 : 1;
+  }
   // The stack pointer is required to be quadword aligned.
-  asm_->Claim(RoundUp(slot_count, 2));
-  size_t slot_index = 0;
+  asm_->Claim(RoundUp(num_slots, 2));
+  size_t poke_offset = num_slots * kXRegSize;
   for (auto& slot : slots_) {
-    size_t poke_offset = (slot_count - slot_index - 1) * kXRegSize;
+    poke_offset -= slot.src_.type() == kWasmS128 ? kXRegSize * 2 : kXRegSize;
     switch (slot.src_.loc()) {
       case LiftoffAssembler::VarState::kStack: {
         UseScratchRegisterScope temps(asm_);
@@ -1213,7 +1452,6 @@ void LiftoffStackSlots::Construct() {
         }
         break;
     }
-    slot_index++;
   }
 }
 
diff --git a/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h b/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
index 7e6356b833..0172b282dc 100644
--- a/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
+++ b/deps/v8/src/wasm/baseline/ia32/liftoff-assembler-ia32.h
@@ -40,20 +40,23 @@ static constexpr LiftoffRegList kByteRegs =
 inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,
                  int32_t offset, ValueType type) {
   Operand src(base, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->mov(dst.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->mov(dst.low_gp(), src);
       assm->mov(dst.high_gp(), Operand(base, offset + 4));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->movss(dst.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->movsd(dst.fp(), src);
       break;
+    case ValueType::kS128:
+      assm->movdqu(dst.fp(), src);
+      break;
     default:
       UNREACHABLE();
   }
@@ -62,18 +65,18 @@ inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,
 inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
                   LiftoffRegister src, ValueType type) {
   Operand dst(base, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->mov(dst, src.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->mov(dst, src.low_gp());
       assm->mov(Operand(base, offset + 4), src.high_gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->movss(dst, src.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->movsd(dst, src.fp());
       break;
     default:
@@ -82,22 +85,26 @@ inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
 }
 
 inline void push(LiftoffAssembler* assm, LiftoffRegister reg, ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->push(reg.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->push(reg.high_gp());
       assm->push(reg.low_gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->AllocateStackSpace(sizeof(float));
       assm->movss(Operand(esp, 0), reg.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->AllocateStackSpace(sizeof(double));
       assm->movsd(Operand(esp, 0), reg.fp());
       break;
+    case ValueType::kS128:
+      assm->AllocateStackSpace(sizeof(double) * 2);
+      assm->movdqu(Operand(esp, 0), reg.fp());
+      break;
     default:
       UNREACHABLE();
   }
@@ -195,18 +202,18 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  return ValueTypes::ElementSizeInBytes(type);
+  return type.element_size_bytes();
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) { return false; }
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       TurboAssembler::Move(reg.gp(), Immediate(value.to_i32(), rmode));
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       DCHECK(RelocInfo::IsNone(rmode));
       int32_t low_word = value.to_i64();
       int32_t high_word = value.to_i64() >> 32;
@@ -214,10 +221,10 @@ void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
       TurboAssembler::Move(reg.high_gp(), Immediate(high_word));
       break;
     }
-    case kWasmF32:
+    case ValueType::kF32:
       TurboAssembler::Move(reg.fp(), value.to_f32_boxed().get_bits());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Move(reg.fp(), value.to_f64_boxed().get_bits());
       break;
     default:
@@ -427,65 +434,56 @@ void LiftoffAssembler::AtomicStore(Register dst_addr, Register offset_reg,
   DCHECK_LE(offset_imm, std::numeric_limits<int32_t>::max());
   Operand dst_op = Operand(dst_addr, offset_reg, times_1, offset_imm);
 
+  // i64 store uses a totally different approach, hence implement it separately.
+  if (type.value() == StoreType::kI64Store) {
+    auto scratch2 = GetUnusedRegister(kFpReg, pinned).fp();
+    movd(liftoff::kScratchDoubleReg, src.low().gp());
+    movd(scratch2, src.high().gp());
+    Punpckldq(liftoff::kScratchDoubleReg, scratch2);
+    movsd(dst_op, liftoff::kScratchDoubleReg);
+    // This lock+or is needed to achieve sequential consistency.
+    lock();
+    or_(Operand(esp, 0), Immediate(0));
+    return;
+  }
+
+  // Other i64 stores actually only use the low word.
+  if (src.is_pair()) src = src.low();
+  Register src_gp = src.gp();
+
+  bool is_byte_store = type.size() == 1;
+  LiftoffRegList src_candidates =
+      is_byte_store ? liftoff::kByteRegs : kGpCacheRegList;
   pinned = pinned | LiftoffRegList::ForRegs(dst_addr, src, offset_reg);
-  Register src_reg = src.is_gp_pair() ? src.low().gp() : src.gp();
-  // If {src} is used after this operation, we are not allowed to overwrite it.
-  // {kI64Store} and {kI(32|64)Store8} need special treatment below, so we don't
-  // handle them here.
-  if (type.value() != StoreType::kI64Store &&
-      type.value() != StoreType::kI64Store8 &&
-      type.value() != StoreType::kI32Store8 && cache_state()->is_used(src)) {
-    Register old_src = src_reg;
-    src_reg = GetUnusedRegister(kGpReg, pinned).gp();
-    mov(src_reg, old_src);
+
+  // Ensure that {src} is a valid and otherwise unused register.
+  if (!src_candidates.has(src) || cache_state_.is_used(src)) {
+    // If there are no unused candidate registers, but {src} is a candidate,
+    // then spill other uses of {src}. Otherwise spill any candidate register
+    // and use that.
+    if (!cache_state_.has_unused_register(src_candidates, pinned) &&
+        src_candidates.has(src)) {
+      SpillRegister(src);
+    } else {
+      Register safe_src = GetUnusedRegister(src_candidates, pinned).gp();
+      mov(safe_src, src_gp);
+      src_gp = safe_src;
+    }
   }
 
   switch (type.value()) {
     case StoreType::kI64Store8:
     case StoreType::kI32Store8:
-      if (cache_state()->is_used(src)) {
-        // Only the lower 4 registers can be addressed as 8-bit registers.
-        if (cache_state()->has_unused_register(liftoff::kByteRegs, pinned)) {
-          Register byte_src =
-              GetUnusedRegister(liftoff::kByteRegs, pinned).gp();
-          mov(byte_src, src_reg);
-          xchg_b(byte_src, dst_op);
-        } else {  // (if !cache_state()->has_unused_register(...))
-          // No byte register is available, we have to spill {src}.
-          push(src_reg);
-          xchg_b(src_reg, dst_op);
-          pop(src_reg);
-        }
-      } else {  // if (!cache_state()->is_used(src)) {
-        if (src_reg.is_byte_register()) {
-          xchg_b(src_reg, dst_op);
-        } else {  // if (!src.gp().is_byte_register())
-          Register byte_src =
-              GetUnusedRegister(liftoff::kByteRegs, pinned).gp();
-          mov(byte_src, src_reg);
-          xchg_b(byte_src, dst_op);
-        }
-      }
+      xchg_b(src_gp, dst_op);
       return;
     case StoreType::kI64Store16:
     case StoreType::kI32Store16:
-      xchg_w(src_reg, dst_op);
+      xchg_w(src_gp, dst_op);
       return;
     case StoreType::kI64Store32:
     case StoreType::kI32Store:
-      xchg(src_reg, dst_op);
-      return;
-    case StoreType::kI64Store: {
-      auto scratch2 = GetUnusedRegister(kFpReg, pinned).fp();
-      movd(liftoff::kScratchDoubleReg, src.low().gp());
-      movd(scratch2, src.high().gp());
-      Punpckldq(liftoff::kScratchDoubleReg, scratch2);
-      movsd(dst_op, liftoff::kScratchDoubleReg);
-      // This lock+or is needed to achieve sequential consistency.
-      lock();
-      or_(Operand(esp, 0), Immediate(0));
+      xchg(src_gp, dst_op);
       return;
-    }
     default:
       UNREACHABLE();
   }
@@ -521,6 +519,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { mfence(); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -565,21 +578,21 @@ void LiftoffAssembler::Move(DoubleRegister dst, DoubleRegister src,
 void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
   RecordUsedSpillOffset(offset);
   Operand dst = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       mov(dst, reg.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       mov(liftoff::GetHalfStackSlot(offset, kLowWord), reg.low_gp());
       mov(liftoff::GetHalfStackSlot(offset, kHighWord), reg.high_gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       movss(dst, reg.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       movsd(dst, reg.fp());
       break;
-    case kWasmS128:
+    case ValueType::kS128:
       movdqu(dst, reg.fp());
       break;
     default:
@@ -590,11 +603,11 @@ void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
 void LiftoffAssembler::Spill(int offset, WasmValue value) {
   RecordUsedSpillOffset(offset);
   Operand dst = liftoff::GetStackSlot(offset);
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       mov(dst, Immediate(value.to_i32()));
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       int32_t low_word = value.to_i64();
       int32_t high_word = value.to_i64() >> 32;
       mov(liftoff::GetHalfStackSlot(offset, kLowWord), Immediate(low_word));
@@ -609,21 +622,21 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
 
 void LiftoffAssembler::Fill(LiftoffRegister reg, int offset, ValueType type) {
   Operand src = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       mov(reg.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       mov(reg.low_gp(), liftoff::GetHalfStackSlot(offset, kLowWord));
       mov(reg.high_gp(), liftoff::GetHalfStackSlot(offset, kHighWord));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       movss(reg.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       movsd(reg.fp(), src);
       break;
-    case kWasmS128:
+    case ValueType::kS128:
       movdqu(reg.fp(), src);
       break;
     default:
@@ -1770,8 +1783,8 @@ void LiftoffAssembler::emit_cond_jump(Condition cond, Label* label,
                                       ValueType type, Register lhs,
                                       Register rhs) {
   if (rhs != no_reg) {
-    switch (type) {
-      case kWasmI32:
+    switch (type.kind()) {
+      case ValueType::kI32:
         cmp(lhs, rhs);
         break;
       default:
@@ -1912,6 +1925,111 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   liftoff::EmitFloatSetCond<&Assembler::ucomisd>(this, cond, dst, lhs, rhs);
 }
 
+namespace liftoff {
+template <void (Assembler::*avx_op)(XMMRegister, XMMRegister, XMMRegister),
+          void (Assembler::*sse_op)(XMMRegister, XMMRegister)>
+void EmitSimdCommutativeBinOp(
+    LiftoffAssembler* assm, LiftoffRegister dst, LiftoffRegister lhs,
+    LiftoffRegister rhs, base::Optional<CpuFeature> feature = base::nullopt) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(assm, AVX);
+    (assm->*avx_op)(dst.fp(), lhs.fp(), rhs.fp());
+    return;
+  }
+
+  base::Optional<CpuFeatureScope> sse_scope;
+  if (feature.has_value()) sse_scope.emplace(assm, *feature);
+
+  if (dst.fp() == rhs.fp()) {
+    (assm->*sse_op)(dst.fp(), lhs.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) (assm->movaps)(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), rhs.fp());
+  }
+}
+
+template <void (Assembler::*avx_op)(XMMRegister, XMMRegister, XMMRegister),
+          void (Assembler::*sse_op)(XMMRegister, XMMRegister)>
+void EmitSimdSub(LiftoffAssembler* assm, LiftoffRegister dst,
+                 LiftoffRegister lhs, LiftoffRegister rhs) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(assm, AVX);
+    (assm->*avx_op)(dst.fp(), lhs.fp(), rhs.fp());
+  } else if (lhs.fp() == rhs.fp()) {
+    assm->pxor(dst.fp(), dst.fp());
+  } else if (dst.fp() == rhs.fp()) {
+    assm->movaps(kScratchDoubleReg, rhs.fp());
+    assm->movaps(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), kScratchDoubleReg);
+  } else {
+    if (dst.fp() != lhs.fp()) assm->movaps(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), rhs.fp());
+  }
+}
+}  // namespace liftoff
+
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movddup(dst.fp(), src.fp());
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vshufpd(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    if (imm_lane_idx != 0) shufpd(dst.fp(), dst.fp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(fanchenk): Use movlhps and blendpd
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    if (imm_lane_idx == 0) {
+      vinsertps(dst.fp(), src1.fp(), src2.fp(), 0b00000000);
+      vinsertps(dst.fp(), dst.fp(), src2.fp(), 0b01010000);
+    } else {
+      vinsertps(dst.fp(), src1.fp(), src2.fp(), 0b00100000);
+      vinsertps(dst.fp(), dst.fp(), src2.fp(), 0b01110000);
+    }
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    if (imm_lane_idx == 0) {
+      insertps(dst.fp(), src2.fp(), 0b00000000);
+      insertps(dst.fp(), src2.fp(), 0b01010000);
+    } else {
+      insertps(dst.fp(), src2.fp(), 0b00100000);
+      insertps(dst.fp(), src2.fp(), 0b01110000);
+    }
+  }
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vaddpd, &Assembler::addpd>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vsubpd, &Assembler::subpd>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vmulpd, &Assembler::mulpd>(
+      this, dst, lhs, rhs);
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   if (CpuFeatures::IsSupported(AVX)) {
@@ -1925,6 +2043,322 @@ void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
   }
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vshufps(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    if (imm_lane_idx != 0) shufps(dst.fp(), dst.fp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vinsertps(dst.fp(), src1.fp(), src2.fp(), (imm_lane_idx << 4) & 0x30);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    insertps(dst.fp(), src2.fp(), (imm_lane_idx << 4) & 0x30);
+  }
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vaddps, &Assembler::addps>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vsubps, &Assembler::subps>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vmulps, &Assembler::mulps>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Pinsrd(dst.fp(), src.low_gp(), 0);
+  Pinsrd(dst.fp(), src.high_gp(), 1);
+  Pshufd(dst.fp(), dst.fp(), 0x44);
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Pextrd(dst.low_gp(), lhs.fp(), imm_lane_idx * 2);
+  Pextrd(dst.high_gp(), lhs.fp(), imm_lane_idx * 2 + 1);
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrd(dst.fp(), src1.fp(), src2.low_gp(), imm_lane_idx * 2);
+    vpinsrd(dst.fp(), dst.fp(), src2.high_gp(), imm_lane_idx * 2 + 1);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrd(dst.fp(), src2.low_gp(), imm_lane_idx * 2);
+    pinsrd(dst.fp(), src2.high_gp(), imm_lane_idx * 2 + 1);
+  }
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddq, &Assembler::paddq>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubq, &Assembler::psubq>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  static constexpr RegClass tmp_rc = reg_class_for(ValueType::kS128);
+  LiftoffRegister tmp1 =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs));
+  LiftoffRegister tmp2 =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs, tmp1));
+  Movaps(tmp1.fp(), lhs.fp());
+  Movaps(tmp2.fp(), rhs.fp());
+  // Multiply high dword of each qword of left with right.
+  Psrlq(tmp1.fp(), 32);
+  Pmuludq(tmp1.fp(), tmp1.fp(), rhs.fp());
+  // Multiply high dword of each qword of right with left.
+  Psrlq(tmp2.fp(), 32);
+  Pmuludq(tmp2.fp(), tmp2.fp(), lhs.fp());
+  Paddq(tmp2.fp(), tmp2.fp(), tmp1.fp());
+  Psllq(tmp2.fp(), tmp2.fp(), 32);
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpmuludq(dst.fp(), lhs.fp(), rhs.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    pmuludq(dst.fp(), rhs.fp());
+  }
+  Paddq(dst.fp(), dst.fp(), tmp2.fp());
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pshufd(dst.fp(), dst.fp(), 0);
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Pextrd(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrd(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrd(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddd, &Assembler::paddd>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubd, &Assembler::psubd>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmulld, &Assembler::pmulld>(
+      this, dst, lhs, rhs, base::Optional<CpuFeature>(SSE4_1));
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pshuflw(dst.fp(), dst.fp(), 0);
+  Pshufd(dst.fp(), dst.fp(), 0);
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrw(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrw(dst.gp(), lhs.fp(), imm_lane_idx);
+  movsx_w(dst.gp(), dst.gp());
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrw(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrw(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddw, &Assembler::paddw>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubw, &Assembler::psubw>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmullw, &Assembler::pmullw>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pxor(liftoff::kScratchDoubleReg, liftoff::kScratchDoubleReg);
+  Pshufb(dst.fp(), liftoff::kScratchDoubleReg);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrb(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrb(dst.gp(), lhs.fp(), imm_lane_idx);
+  movsx_b(dst.gp(), dst.gp());
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrb(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrb(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddb, &Assembler::paddb>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubb, &Assembler::psubb>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  static constexpr RegClass tmp_rc = reg_class_for(ValueType::kS128);
+  LiftoffRegister tmp =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs));
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    // I16x8 view of I8x16
+    // left = AAaa AAaa ... AAaa AAaa
+    // right= BBbb BBbb ... BBbb BBbb
+    // t = 00AA 00AA ... 00AA 00AA
+    // s = 00BB 00BB ... 00BB 00BB
+    vpsrlw(tmp.fp(), lhs.fp(), 8);
+    vpsrlw(liftoff::kScratchDoubleReg, rhs.fp(), 8);
+    // t = I16x8Mul(t0, t1)
+    //    => __PP __PP ...  __PP  __PP
+    vpmullw(tmp.fp(), tmp.fp(), liftoff::kScratchDoubleReg);
+    // s = left * 256
+    vpsllw(liftoff::kScratchDoubleReg, lhs.fp(), 8);
+    // dst = I16x8Mul(left * 256, right)
+    //    => pp__ pp__ ...  pp__  pp__
+    vpmullw(dst.fp(), liftoff::kScratchDoubleReg, rhs.fp());
+    // dst = I16x8Shr(dst, 8)
+    //    => 00pp 00pp ...  00pp  00pp
+    vpsrlw(dst.fp(), dst.fp(), 8);
+    // t = I16x8Shl(t, 8)
+    //    => PP00 PP00 ...  PP00  PP00
+    vpsllw(tmp.fp(), tmp.fp(), 8);
+    // dst = I16x8Or(dst, t)
+    //    => PPpp PPpp ...  PPpp  PPpp
+    vpor(dst.fp(), dst.fp(), tmp.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    // I16x8 view of I8x16
+    // left = AAaa AAaa ... AAaa AAaa
+    // right= BBbb BBbb ... BBbb BBbb
+    // t = 00AA 00AA ... 00AA 00AA
+    // s = 00BB 00BB ... 00BB 00BB
+    movaps(tmp.fp(), dst.fp());
+    movaps(liftoff::kScratchDoubleReg, rhs.fp());
+    psrlw(tmp.fp(), 8);
+    psrlw(liftoff::kScratchDoubleReg, 8);
+    // dst = left * 256
+    psllw(dst.fp(), 8);
+    // t = I16x8Mul(t, s)
+    //    => __PP __PP ...  __PP  __PP
+    pmullw(tmp.fp(), liftoff::kScratchDoubleReg);
+    // dst = I16x8Mul(left * 256, right)
+    //    => pp__ pp__ ...  pp__  pp__
+    pmullw(dst.fp(), rhs.fp());
+    // t = I16x8Shl(t, 8)
+    //    => PP00 PP00 ...  PP00  PP00
+    psllw(tmp.fp(), 8);
+    // dst = I16x8Shr(dst, 8)
+    //    => 00pp 00pp ...  00pp  00pp
+    psrlw(dst.fp(), 8);
+    // dst = I16x8Or(dst, t)
+    //    => PPpp PPpp ...  PPpp  PPpp
+    por(dst.fp(), tmp.fp());
+  }
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   cmp(esp, Operand(limit_address, 0));
   j(below_equal, ool_code);
@@ -1985,7 +2419,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   ret(static_cast<int>(num_stack_slots * kSystemPointerSize));
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1995,7 +2429,7 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
     liftoff::Store(this, esp, arg_bytes, *args++, param_type);
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -2035,7 +2469,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   wasm_call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   // Since we have more cache registers than parameter registers, the
@@ -2063,13 +2497,20 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   add(esp, Immediate(size));
 }
 
-void LiftoffAssembler::DebugBreak() { int3(); }
-
 void LiftoffStackSlots::Construct() {
   for (auto& slot : slots_) {
     const LiftoffAssembler::VarState& src = slot.src_;
     switch (src.loc()) {
       case LiftoffAssembler::VarState::kStack:
+        // The combination of AllocateStackSpace and 2 movdqu is usually smaller
+        // in code size than doing 4 pushes.
+        if (src.type() == kWasmS128) {
+          asm_->AllocateStackSpace(sizeof(double) * 2);
+          asm_->movdqu(liftoff::kScratchDoubleReg,
+                       liftoff::GetStackSlot(slot.src_offset_));
+          asm_->movdqu(Operand(esp, 0), liftoff::kScratchDoubleReg);
+          break;
+        }
         if (src.type() == kWasmF64) {
           DCHECK_EQ(kLowWord, slot.half_);
           asm_->push(liftoff::GetHalfStackSlot(slot.src_offset_, kHighWord));
diff --git a/deps/v8/src/wasm/baseline/liftoff-assembler.cc b/deps/v8/src/wasm/baseline/liftoff-assembler.cc
index 68a8ad6e48..74df00590f 100644
--- a/deps/v8/src/wasm/baseline/liftoff-assembler.cc
+++ b/deps/v8/src/wasm/baseline/liftoff-assembler.cc
@@ -22,6 +22,8 @@ namespace wasm {
 
 using VarState = LiftoffAssembler::VarState;
 
+constexpr ValueType LiftoffAssembler::kWasmIntPtr;
+
 namespace {
 
 class StackTransferRecipe {
@@ -214,6 +216,10 @@ class StackTransferRecipe {
           RegisterLoad::HalfStack(stack_offset, kHighWord);
     } else if (dst.is_fp_pair()) {
       DCHECK_EQ(kWasmS128, type);
+      // load_dst_regs_.set above will set both low and high fp regs.
+      // But unlike gp_pair, we load a kWasm128 in one go in ExecuteLoads.
+      // So unset the top fp register to skip loading it.
+      load_dst_regs_.clear(dst.high());
       *register_load(dst.low()) = RegisterLoad::Stack(stack_offset, type);
     } else {
       *register_load(dst) = RegisterLoad::Stack(stack_offset, type);
@@ -353,7 +359,9 @@ class RegisterReuseMap {
 
   base::Optional<LiftoffRegister> Lookup(LiftoffRegister src) {
     for (auto it = map_.begin(), end = map_.end(); it != end; it += 2) {
-      if (it->is_gp_pair() == src.is_gp_pair() && *it == src) return *(it + 1);
+      if (it->is_gp_pair() == src.is_gp_pair() &&
+          it->is_fp_pair() == src.is_fp_pair() && *it == src)
+        return *(it + 1);
     }
     return {};
   }
@@ -499,10 +507,8 @@ LiftoffAssembler::~LiftoffAssembler() {
   }
 }
 
-LiftoffRegister LiftoffAssembler::PopToRegister(LiftoffRegList pinned) {
-  DCHECK(!cache_state_.stack_state.empty());
-  VarState slot = cache_state_.stack_state.back();
-  cache_state_.stack_state.pop_back();
+LiftoffRegister LiftoffAssembler::LoadToRegister(VarState slot,
+                                                 LiftoffRegList pinned) {
   switch (slot.loc()) {
     case VarState::kStack: {
       LiftoffRegister reg =
@@ -524,6 +530,24 @@ LiftoffRegister LiftoffAssembler::PopToRegister(LiftoffRegList pinned) {
   UNREACHABLE();
 }
 
+LiftoffRegister LiftoffAssembler::PopToRegister(LiftoffRegList pinned) {
+  DCHECK(!cache_state_.stack_state.empty());
+  VarState slot = cache_state_.stack_state.back();
+  cache_state_.stack_state.pop_back();
+  return LoadToRegister(slot, pinned);
+}
+
+LiftoffRegister LiftoffAssembler::PeekToRegister(int index,
+                                                 LiftoffRegList pinned) {
+  DCHECK_LT(index, cache_state_.stack_state.size());
+  VarState& slot = cache_state_.stack_state.end()[-1 - index];
+  LiftoffRegister reg = LoadToRegister(slot, pinned);
+  if (!slot.is_reg()) {
+    slot.MakeRegister(reg);
+  }
+  return reg;
+}
+
 void LiftoffAssembler::MergeFullStackWith(const CacheState& target,
                                           const CacheState& source) {
   DCHECK_EQ(source.stack_height(), target.stack_height());
@@ -590,55 +614,24 @@ void LiftoffAssembler::SpillAllRegisters() {
   cache_state_.reset_used_registers();
 }
 
-void LiftoffAssembler::PrepareCall(FunctionSig* sig,
-                                   compiler::CallDescriptor* call_descriptor,
-                                   Register* target,
-                                   Register* target_instance) {
-  uint32_t num_params = static_cast<uint32_t>(sig->parameter_count());
-  // Input 0 is the call target.
-  constexpr size_t kInputShift = 1;
-
-  // Spill all cache slots which are not being used as parameters.
-  // Don't update any register use counters, they will be reset later anyway.
-  for (uint32_t idx = 0, end = cache_state_.stack_height() - num_params;
-       idx < end; ++idx) {
-    VarState& slot = cache_state_.stack_state[idx];
-    if (!slot.is_reg()) continue;
-    Spill(slot.offset(), slot.reg(), slot.type());
-    slot.MakeStack();
-  }
-
-  LiftoffStackSlots stack_slots(this);
-  StackTransferRecipe stack_transfers(this);
-  LiftoffRegList param_regs;
-
-  // Move the target instance (if supplied) into the correct instance register.
-  compiler::LinkageLocation instance_loc =
-      call_descriptor->GetInputLocation(kInputShift);
-  DCHECK(instance_loc.IsRegister() && !instance_loc.IsAnyRegister());
-  Register instance_reg = Register::from_code(instance_loc.AsRegister());
-  param_regs.set(instance_reg);
-  if (target_instance && *target_instance != instance_reg) {
-    stack_transfers.MoveRegister(LiftoffRegister(instance_reg),
-                                 LiftoffRegister(*target_instance),
-                                 kWasmIntPtr);
-  }
-
-  // Now move all parameter values into the right slot for the call.
-  // Don't pop values yet, such that the stack height is still correct when
-  // executing the {stack_transfers}.
+namespace {
+void PrepareStackTransfers(const FunctionSig* sig,
+                           compiler::CallDescriptor* call_descriptor,
+                           const VarState* slots,
+                           LiftoffStackSlots* stack_slots,
+                           StackTransferRecipe* stack_transfers,
+                           LiftoffRegList* param_regs) {
   // Process parameters backwards, such that pushes of caller frame slots are
   // in the correct order.
-  uint32_t param_base = cache_state_.stack_height() - num_params;
   uint32_t call_desc_input_idx =
       static_cast<uint32_t>(call_descriptor->InputCount());
+  uint32_t num_params = static_cast<uint32_t>(sig->parameter_count());
   for (uint32_t i = num_params; i > 0; --i) {
     const uint32_t param = i - 1;
     ValueType type = sig->GetParam(param);
     const bool is_gp_pair = kNeedI64RegPair && type == kWasmI64;
     const int num_lowered_params = is_gp_pair ? 2 : 1;
-    const uint32_t stack_idx = param_base + param;
-    const VarState& slot = cache_state_.stack_state[stack_idx];
+    const VarState& slot = slots[param];
     const uint32_t stack_offset = slot.offset();
     // Process both halfs of a register pair separately, because they are passed
     // as separate parameters. One or both of them could end up on the stack.
@@ -671,21 +664,81 @@ void LiftoffAssembler::PrepareCall(FunctionSig* sig,
           reg = LiftoffRegister::from_code(rc, reg_code);
         }
 
-        param_regs.set(reg);
+        param_regs->set(reg);
         if (is_gp_pair) {
-          stack_transfers.LoadI64HalfIntoRegister(reg, slot, stack_offset,
-                                                  half);
+          stack_transfers->LoadI64HalfIntoRegister(reg, slot, stack_offset,
+                                                   half);
         } else {
-          stack_transfers.LoadIntoRegister(reg, slot, stack_offset);
+          stack_transfers->LoadIntoRegister(reg, slot, stack_offset);
         }
       } else {
         DCHECK(loc.IsCallerFrameSlot());
-        stack_slots.Add(slot, stack_offset, half);
+        stack_slots->Add(slot, stack_offset, half);
       }
     }
   }
-  // {call_desc_input_idx} should point after the instance parameter now.
-  DCHECK_EQ(call_desc_input_idx, kInputShift + 1);
+}
+
+}  // namespace
+
+void LiftoffAssembler::PrepareBuiltinCall(
+    const FunctionSig* sig, compiler::CallDescriptor* call_descriptor,
+    std::initializer_list<VarState> params) {
+  LiftoffStackSlots stack_slots(this);
+  StackTransferRecipe stack_transfers(this);
+  LiftoffRegList param_regs;
+  PrepareStackTransfers(sig, call_descriptor, params.begin(), &stack_slots,
+                        &stack_transfers, &param_regs);
+  // Create all the slots.
+  stack_slots.Construct();
+  // Execute the stack transfers before filling the instance register.
+  stack_transfers.Execute();
+
+  // Reset register use counters.
+  cache_state_.reset_used_registers();
+  SpillAllRegisters();
+}
+
+void LiftoffAssembler::PrepareCall(const FunctionSig* sig,
+                                   compiler::CallDescriptor* call_descriptor,
+                                   Register* target,
+                                   Register* target_instance) {
+  uint32_t num_params = static_cast<uint32_t>(sig->parameter_count());
+  // Input 0 is the call target.
+  constexpr size_t kInputShift = 1;
+
+  // Spill all cache slots which are not being used as parameters.
+  // Don't update any register use counters, they will be reset later anyway.
+  for (uint32_t idx = 0, end = cache_state_.stack_height() - num_params;
+       idx < end; ++idx) {
+    VarState& slot = cache_state_.stack_state[idx];
+    if (!slot.is_reg()) continue;
+    Spill(slot.offset(), slot.reg(), slot.type());
+    slot.MakeStack();
+  }
+
+  LiftoffStackSlots stack_slots(this);
+  StackTransferRecipe stack_transfers(this);
+  LiftoffRegList param_regs;
+
+  // Move the target instance (if supplied) into the correct instance register.
+  compiler::LinkageLocation instance_loc =
+      call_descriptor->GetInputLocation(kInputShift);
+  DCHECK(instance_loc.IsRegister() && !instance_loc.IsAnyRegister());
+  Register instance_reg = Register::from_code(instance_loc.AsRegister());
+  param_regs.set(instance_reg);
+  if (target_instance && *target_instance != instance_reg) {
+    stack_transfers.MoveRegister(LiftoffRegister(instance_reg),
+                                 LiftoffRegister(*target_instance),
+                                 kWasmIntPtr);
+  }
+
+  if (num_params) {
+    uint32_t param_base = cache_state_.stack_height() - num_params;
+    PrepareStackTransfers(sig, call_descriptor,
+                          &cache_state_.stack_state[param_base], &stack_slots,
+                          &stack_transfers, &param_regs);
+  }
 
   // If the target register overlaps with a parameter register, then move the
   // target to another free register, or spill to the stack.
@@ -721,7 +774,7 @@ void LiftoffAssembler::PrepareCall(FunctionSig* sig,
   }
 }
 
-void LiftoffAssembler::FinishCall(FunctionSig* sig,
+void LiftoffAssembler::FinishCall(const FunctionSig* sig,
                                   compiler::CallDescriptor* call_descriptor) {
   const size_t return_count = sig->return_count();
   if (return_count != 0) {
@@ -779,7 +832,7 @@ void LiftoffAssembler::ParallelRegisterMove(
   }
 }
 
-void LiftoffAssembler::MoveToReturnRegisters(FunctionSig* sig) {
+void LiftoffAssembler::MoveToReturnRegisters(const FunctionSig* sig) {
   // We do not support multi-value yet.
   DCHECK_EQ(1, sig->return_count());
   ValueType return_type = sig->GetReturn(0);
@@ -916,7 +969,7 @@ void LiftoffAssembler::set_num_locals(uint32_t num_locals) {
 }
 
 std::ostream& operator<<(std::ostream& os, VarState slot) {
-  os << ValueTypes::TypeName(slot.type()) << ":";
+  os << slot.type().type_name() << ":";
   switch (slot.loc()) {
     case VarState::kStack:
       return os << "s";
diff --git a/deps/v8/src/wasm/baseline/liftoff-assembler.h b/deps/v8/src/wasm/baseline/liftoff-assembler.h
index 868b9390d1..6573ff4aa4 100644
--- a/deps/v8/src/wasm/baseline/liftoff-assembler.h
+++ b/deps/v8/src/wasm/baseline/liftoff-assembler.h
@@ -103,6 +103,11 @@ class LiftoffAssembler : public TurboAssembler {
 
     void MakeStack() { loc_ = kStack; }
 
+    void MakeRegister(LiftoffRegister r) {
+      reg_ = r;
+      loc_ = kRegister;
+    }
+
     // Copy src to this, except for offset, since src and this could have been
     // from different stack states.
     void Copy(VarState src) {
@@ -282,6 +287,16 @@ class LiftoffAssembler : public TurboAssembler {
 
   LiftoffRegister PopToRegister(LiftoffRegList pinned = {});
 
+  // Returns the register which holds the value of stack slot {index}. If the
+  // value is not stored in a register yet, a register is allocated for it. The
+  // register is then assigned to the stack slot. The value stack height is not
+  // modified. The top of the stack is index 0, i.e. {PopToRegister()} and
+  // {PeekToRegister(0)} should result in the same register.
+  // {PeekToRegister} already decrements the used count of the register of the
+  // stack slot. Therefore the register must not be popped by {PopToRegister}
+  // but discarded with {stack_state.pop_back(count)}.
+  LiftoffRegister PeekToRegister(int index, LiftoffRegList pinned);
+
   int NextSpillOffset(ValueType type) {
     int offset = TopSpillOffset() + SlotSizeForType(type);
     if (NeedsAlignment(type)) {
@@ -374,13 +389,18 @@ class LiftoffAssembler : public TurboAssembler {
   }
 
   // Load parameters into the right registers / stack slots for the call.
+  void PrepareBuiltinCall(const FunctionSig* sig,
+                          compiler::CallDescriptor* call_descriptor,
+                          std::initializer_list<VarState> params);
+
+  // Load parameters into the right registers / stack slots for the call.
   // Move {*target} into another register if needed and update {*target} to that
   // register, or {no_reg} if target was spilled to the stack.
-  void PrepareCall(FunctionSig*, compiler::CallDescriptor*,
+  void PrepareCall(const FunctionSig*, compiler::CallDescriptor*,
                    Register* target = nullptr,
                    Register* target_instance = nullptr);
   // Process return values of the call.
-  void FinishCall(FunctionSig*, compiler::CallDescriptor*);
+  void FinishCall(const FunctionSig*, compiler::CallDescriptor*);
 
   // Move {src} into {dst}. {src} and {dst} must be different.
   void Move(LiftoffRegister dst, LiftoffRegister src, ValueType);
@@ -398,7 +418,7 @@ class LiftoffAssembler : public TurboAssembler {
   };
   void ParallelRegisterMove(Vector<ParallelRegisterMoveTuple>);
 
-  void MoveToReturnRegisters(FunctionSig*);
+  void MoveToReturnRegisters(const FunctionSig*);
 
 #ifdef ENABLE_SLOW_DCHECKS
   // Validate that the register use counts reflect the state of the cache.
@@ -465,6 +485,18 @@ class LiftoffAssembler : public TurboAssembler {
                         uint32_t offset_imm, LiftoffRegister result,
                         StoreType type);
 
+  inline void AtomicExchange(Register dst_addr, Register offset_reg,
+                             uint32_t offset_imm, LiftoffRegister result,
+                             StoreType type);
+
+  inline void AtomicCompareExchange(Register dst_addr, Register offset_reg,
+                                    uint32_t offset_imm,
+                                    LiftoffRegister expected,
+                                    LiftoffRegister new_value,
+                                    LiftoffRegister value, StoreType type);
+
+  inline void AtomicFence();
+
   inline void LoadCallerFrameSlot(LiftoffRegister, uint32_t caller_slot_idx,
                                   ValueType);
   inline void MoveStackValue(uint32_t dst_offset, uint32_t src_offset,
@@ -679,7 +711,86 @@ class LiftoffAssembler : public TurboAssembler {
   inline void emit_f64_set_cond(Condition condition, Register dst,
                                 DoubleRegister lhs, DoubleRegister rhs);
 
+  inline void emit_f64x2_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_f64x2_extract_lane(LiftoffRegister dst, LiftoffRegister lhs,
+                                      uint8_t imm_lane_idx);
+  inline void emit_f64x2_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
   inline void emit_f32x4_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_f32x4_extract_lane(LiftoffRegister dst, LiftoffRegister lhs,
+                                      uint8_t imm_lane_idx);
+  inline void emit_f32x4_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i64x2_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i64x2_extract_lane(LiftoffRegister dst, LiftoffRegister lhs,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i64x2_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i32x4_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i32x4_extract_lane(LiftoffRegister dst, LiftoffRegister lhs,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i32x4_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i16x8_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                        LiftoffRegister lhs,
+                                        uint8_t imm_lane_idx);
+  inline void emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                        LiftoffRegister lhs,
+                                        uint8_t imm_lane_idx);
+  inline void emit_i16x8_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i8x16_splat(LiftoffRegister dst, LiftoffRegister src);
+  inline void emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                        LiftoffRegister lhs,
+                                        uint8_t imm_lane_idx);
+  inline void emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                        LiftoffRegister lhs,
+                                        uint8_t imm_lane_idx);
+  inline void emit_i8x16_replace_lane(LiftoffRegister dst, LiftoffRegister src1,
+                                      LiftoffRegister src2,
+                                      uint8_t imm_lane_idx);
+  inline void emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
+  inline void emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                             LiftoffRegister rhs);
 
   inline void StackCheck(Label* ool_code, Register limit_address);
 
@@ -697,13 +808,13 @@ class LiftoffAssembler : public TurboAssembler {
   // this is the return value of the C function, stored in {rets[0]}. Further
   // outputs (specified in {sig->returns()}) are read from the buffer and stored
   // in the remaining {rets} registers.
-  inline void CallC(FunctionSig* sig, const LiftoffRegister* args,
+  inline void CallC(const FunctionSig* sig, const LiftoffRegister* args,
                     const LiftoffRegister* rets, ValueType out_argument_type,
                     int stack_bytes, ExternalReference ext_ref);
 
   inline void CallNativeWasmCode(Address addr);
   // Indirect call: If {target == no_reg}, then pop the target from the stack.
-  inline void CallIndirect(FunctionSig* sig,
+  inline void CallIndirect(const FunctionSig* sig,
                            compiler::CallDescriptor* call_descriptor,
                            Register target);
   inline void CallRuntimeStub(WasmCode::RuntimeStubId sid);
@@ -712,7 +823,6 @@ class LiftoffAssembler : public TurboAssembler {
   inline void AllocateStackSlot(Register addr, uint32_t size);
   inline void DeallocateStackSlot(uint32_t size);
 
-  inline void DebugBreak();
   ////////////////////////////////////
   // End of platform-specific part. //
   ////////////////////////////////////
@@ -756,6 +866,8 @@ class LiftoffAssembler : public TurboAssembler {
   }
 
  private:
+  LiftoffRegister LoadToRegister(VarState slot, LiftoffRegList pinned);
+
   uint32_t num_locals_ = 0;
   static constexpr uint32_t kInlineLocalTypes = 8;
   union {
@@ -927,7 +1039,7 @@ class LiftoffStackSlots {
 #include "src/wasm/baseline/arm64/liftoff-assembler-arm64.h"
 #elif V8_TARGET_ARCH_ARM
 #include "src/wasm/baseline/arm/liftoff-assembler-arm.h"
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 #include "src/wasm/baseline/ppc/liftoff-assembler-ppc.h"
 #elif V8_TARGET_ARCH_MIPS
 #include "src/wasm/baseline/mips/liftoff-assembler-mips.h"
diff --git a/deps/v8/src/wasm/baseline/liftoff-compiler.cc b/deps/v8/src/wasm/baseline/liftoff-compiler.cc
index f396b76244..377cd1b5a8 100644
--- a/deps/v8/src/wasm/baseline/liftoff-compiler.cc
+++ b/deps/v8/src/wasm/baseline/liftoff-compiler.cc
@@ -81,6 +81,9 @@ struct assert_field_size {
 constexpr LoadType::LoadTypeValue kPointerLoadType =
     kSystemPointerSize == 8 ? LoadType::kI64Load : LoadType::kI32Load;
 
+constexpr ValueType kPointerValueType =
+    kSystemPointerSize == 8 ? kWasmI64 : kWasmI32;
+
 #if V8_TARGET_ARCH_ARM64
 // On ARM64, the Assembler keeps track of pointers to Labels to resolve
 // branches to distant targets. Moving labels would confuse the Assembler,
@@ -155,21 +158,25 @@ constexpr Condition GetCompareCondition(WasmOpcode opcode) {
 // Builds a {DebugSideTable}.
 class DebugSideTableBuilder {
  public:
+  enum AssumeSpilling {
+    // All register values will be spilled before the pc covered by the debug
+    // side table entry. Register slots will be marked as stack slots in the
+    // generated debug side table entry.
+    kAssumeSpilling,
+    // Register slots will be written out as they are.
+    kAllowRegisters,
+    // Register slots cannot appear since we already spilled.
+    kDidSpill
+  };
+
   class EntryBuilder {
    public:
-    explicit EntryBuilder(
-        int pc_offset, std::vector<ValueType> stack_types,
-        std::vector<int> stack_offsets,
-        std::vector<DebugSideTable::Entry::Constant> constants)
-        : pc_offset_(pc_offset),
-          stack_types_(std::move(stack_types)),
-          stack_offsets_(std::move(stack_offsets)),
-          constants_(std::move(constants)) {}
+    explicit EntryBuilder(int pc_offset,
+                          std::vector<DebugSideTable::Entry::Value> values)
+        : pc_offset_(pc_offset), values_(std::move(values)) {}
 
-    DebugSideTable::Entry ToTableEntry() const {
-      return DebugSideTable::Entry{pc_offset_, std::move(stack_types_),
-                                   std::move(stack_offsets_),
-                                   std::move(constants_)};
+    DebugSideTable::Entry ToTableEntry() {
+      return DebugSideTable::Entry{pc_offset_, std::move(values_)};
     }
 
     int pc_offset() const { return pc_offset_; }
@@ -177,59 +184,65 @@ class DebugSideTableBuilder {
 
    private:
     int pc_offset_;
-    std::vector<ValueType> stack_types_;
-    std::vector<int> stack_offsets_;
-    std::vector<DebugSideTable::Entry::Constant> constants_;
+    std::vector<DebugSideTable::Entry::Value> values_;
   };
 
   // Adds a new entry, and returns a pointer to a builder for modifying that
   // entry ({stack_height} includes {num_locals}).
   EntryBuilder* NewEntry(int pc_offset, int num_locals, int stack_height,
-                         LiftoffAssembler::VarState* stack_state) {
+                         LiftoffAssembler::VarState* stack_state,
+                         AssumeSpilling assume_spilling) {
     DCHECK_LE(num_locals, stack_height);
     // Record stack types.
-    int stack_height_without_locals = stack_height - num_locals;
-    std::vector<ValueType> stack_types(stack_height_without_locals);
-    for (int i = 0; i < stack_height_without_locals; ++i) {
-      stack_types[i] = stack_state[num_locals + i].type();
-    }
-    // Record stack offsets.
-    std::vector<int> stack_offsets(stack_height_without_locals);
-    for (int i = 0; i < stack_height_without_locals; ++i) {
-      stack_offsets[i] = stack_state[num_locals + i].offset();
-    }
-    // Record all constants on the locals and stack.
-    std::vector<DebugSideTable::Entry::Constant> constants;
-    for (int idx = 0; idx < stack_height; ++idx) {
-      auto& slot = stack_state[idx];
-      if (slot.is_const()) constants.push_back({idx, slot.i32_const()});
-    }
-    entries_.emplace_back(pc_offset, std::move(stack_types),
-                          std::move(stack_offsets), std::move(constants));
+    std::vector<DebugSideTable::Entry::Value> values(stack_height);
+    for (int i = 0; i < stack_height; ++i) {
+      const auto& slot = stack_state[i];
+      values[i].type = slot.type();
+      values[i].stack_offset = slot.offset();
+      switch (slot.loc()) {
+        case kIntConst:
+          values[i].kind = DebugSideTable::Entry::kConstant;
+          values[i].i32_const = slot.i32_const();
+          break;
+        case kRegister:
+          DCHECK_NE(kDidSpill, assume_spilling);
+          if (assume_spilling == kAllowRegisters) {
+            values[i].kind = DebugSideTable::Entry::kRegister;
+            values[i].reg_code = slot.reg().liftoff_code();
+            break;
+          }
+          DCHECK_EQ(kAssumeSpilling, assume_spilling);
+          V8_FALLTHROUGH;
+        case kStack:
+          values[i].kind = DebugSideTable::Entry::kStack;
+          values[i].stack_offset = slot.offset();
+          break;
+      }
+    }
+    entries_.emplace_back(pc_offset, std::move(values));
     return &entries_.back();
   }
 
-  void AddLocalType(ValueType type, int stack_offset) {
-    local_types_.push_back(type);
-    local_stack_offsets_.push_back(stack_offset);
+  void SetNumLocals(int num_locals) {
+    DCHECK_EQ(-1, num_locals_);
+    DCHECK_LE(0, num_locals);
+    num_locals_ = num_locals;
   }
 
-  DebugSideTable GenerateDebugSideTable() {
-    std::vector<DebugSideTable::Entry> table_entries;
-    table_entries.reserve(entries_.size());
-    for (auto& entry : entries_) table_entries.push_back(entry.ToTableEntry());
-    std::sort(table_entries.begin(), table_entries.end(),
+  std::unique_ptr<DebugSideTable> GenerateDebugSideTable() {
+    DCHECK_LE(0, num_locals_);
+    std::vector<DebugSideTable::Entry> entries;
+    entries.reserve(entries_.size());
+    for (auto& entry : entries_) entries.push_back(entry.ToTableEntry());
+    std::sort(entries.begin(), entries.end(),
               [](DebugSideTable::Entry& a, DebugSideTable::Entry& b) {
                 return a.pc_offset() < b.pc_offset();
               });
-    return DebugSideTable{std::move(local_types_),
-                          std::move(local_stack_offsets_),
-                          std::move(table_entries)};
+    return std::make_unique<DebugSideTable>(num_locals_, std::move(entries));
   }
 
  private:
-  std::vector<ValueType> local_types_;
-  std::vector<int> local_stack_offsets_;
+  int num_locals_ = -1;
   std::list<EntryBuilder> entries_;
 };
 
@@ -287,7 +300,8 @@ class LiftoffCompiler {
                   CompilationEnv* env, Zone* compilation_zone,
                   std::unique_ptr<AssemblerBuffer> buffer,
                   DebugSideTableBuilder* debug_sidetable_builder,
-                  Vector<int> breakpoints = {})
+                  Vector<int> breakpoints = {},
+                  Vector<int> extra_source_pos = {})
       : asm_(std::move(buffer)),
         descriptor_(
             GetLoweredCallDescriptor(compilation_zone, call_descriptor)),
@@ -296,7 +310,16 @@ class LiftoffCompiler {
         compilation_zone_(compilation_zone),
         safepoint_table_builder_(compilation_zone_),
         next_breakpoint_ptr_(breakpoints.begin()),
-        next_breakpoint_end_(breakpoints.end()) {}
+        next_breakpoint_end_(breakpoints.end()),
+        next_extra_source_pos_ptr_(extra_source_pos.begin()),
+        next_extra_source_pos_end_(extra_source_pos.end()) {
+    if (breakpoints.empty()) {
+      next_breakpoint_ptr_ = next_breakpoint_end_ = nullptr;
+    }
+    if (extra_source_pos.empty()) {
+      next_extra_source_pos_ptr_ = next_extra_source_pos_end_ = nullptr;
+    }
+  }
 
   bool did_bailout() const { return bailout_reason_ != kSuccess; }
   LiftoffBailoutReason bailout_reason() const { return bailout_reason_; }
@@ -310,10 +333,9 @@ class LiftoffCompiler {
     return source_position_table_builder_.ToSourcePositionTableVector();
   }
 
-  OwnedVector<trap_handler::ProtectedInstructionData> GetProtectedInstructions()
-      const {
-    return OwnedVector<trap_handler::ProtectedInstructionData>::Of(
-        protected_instructions_);
+  OwnedVector<uint8_t> GetProtectedInstructionsData() const {
+    return OwnedVector<uint8_t>::Of(
+        Vector<const uint8_t>::cast(VectorOf(protected_instructions_)));
   }
 
   uint32_t GetTotalFrameSlotCount() const {
@@ -338,16 +360,16 @@ class LiftoffCompiler {
   }
 
   LiftoffBailoutReason BailoutReasonForType(ValueType type) {
-    switch (type) {
-      case kWasmS128:
+    switch (type.kind()) {
+      case ValueType::kS128:
         return kSimd;
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
+      case ValueType::kAnyRef:
+      case ValueType::kFuncRef:
+      case ValueType::kNullRef:
         return kAnyRef;
-      case kWasmExnRef:
+      case ValueType::kExnRef:
         return kExceptionHandling;
-      case kWasmBottom:
+      case ValueType::kBottom:
         return kMultiValue;
       default:
         return kOtherReason;
@@ -368,7 +390,7 @@ class LiftoffCompiler {
     }
     LiftoffBailoutReason bailout_reason = BailoutReasonForType(type);
     EmbeddedVector<char, 128> buffer;
-    SNPrintF(buffer, "%s %s", ValueTypes::TypeName(type), context);
+    SNPrintF(buffer, "%s %s", type.type_name(), context);
     unsupported(decoder, bailout_reason, buffer.begin());
     return false;
   }
@@ -476,10 +498,11 @@ class LiftoffCompiler {
   }
 
   void StackCheck(WasmCodePosition position) {
+    DEBUG_CODE_COMMENT("stack check");
     if (!FLAG_wasm_stack_checks || !env_->runtime_exception_support) return;
-    out_of_line_code_.push_back(
-        OutOfLineCode::StackCheck(position, __ cache_state()->used_registers,
-                                  RegisterDebugSideTableEntry()));
+    out_of_line_code_.push_back(OutOfLineCode::StackCheck(
+        position, __ cache_state()->used_registers,
+        RegisterDebugSideTableEntry(DebugSideTableBuilder::kAssumeSpilling)));
     OutOfLineCode& ool = out_of_line_code_.back();
     Register limit_address = __ GetUnusedRegister(kGpReg).gp();
     LOAD_INSTANCE_FIELD(limit_address, StackLimitAddress, kSystemPointerSize);
@@ -526,6 +549,9 @@ class LiftoffCompiler {
     uint32_t num_params =
         static_cast<uint32_t>(decoder->sig_->parameter_count());
 
+    __ CodeEntry();
+
+    DEBUG_CODE_COMMENT("enter frame");
     __ EnterFrame(StackFrame::WASM_COMPILED);
     __ set_has_frame(true);
     pc_offset_stack_frame_construction_ = __ PrepareStackFrame();
@@ -538,6 +564,7 @@ class LiftoffCompiler {
     if (DidAssemblerBailout(decoder)) return;
 
     // Process parameters.
+    if (num_params) DEBUG_CODE_COMMENT("process parameters");
     __ SpillInstance(instance_reg);
     // Input 0 is the code target, 1 is the instance. First parameter at 2.
     uint32_t input_idx = kInstanceParameterIndex + 1;
@@ -548,6 +575,7 @@ class LiftoffCompiler {
     DCHECK_EQ(input_idx, descriptor_->InputCount());
 
     // Initialize locals beyond parameters.
+    if (num_params < __ num_locals()) DEBUG_CODE_COMMENT("init locals");
     if (SpillLocalsInitially(decoder, num_params)) {
       for (uint32_t param_idx = num_params; param_idx < __ num_locals();
            ++param_idx) {
@@ -566,16 +594,37 @@ class LiftoffCompiler {
 
     DCHECK_EQ(__ num_locals(), __ cache_state()->stack_height());
 
-    // Register local types and stack offsets for the debug side table.
     if (V8_UNLIKELY(debug_sidetable_builder_)) {
-      for (uint32_t i = 0; i < __ num_locals(); ++i) {
-        debug_sidetable_builder_->AddLocalType(
-            __ local_type(i), __ cache_state()->stack_state[i].offset());
-      }
+      debug_sidetable_builder_->SetNumLocals(__ num_locals());
     }
+
     // The function-prologue stack check is associated with position 0, which
     // is never a position of any instruction in the function.
     StackCheck(0);
+
+    // If we are generating debug code, do check the "hook on function call"
+    // flag. If set, trigger a break.
+    if (V8_UNLIKELY(env_->debug)) {
+      // If there is a breakpoint set on the first instruction (== start of the
+      // function), then skip the check for "hook on function call", since we
+      // will unconditionally break there anyway.
+      bool has_breakpoint = next_breakpoint_ptr_ != nullptr &&
+                            (*next_breakpoint_ptr_ == 0 ||
+                             *next_breakpoint_ptr_ == decoder->position());
+      if (!has_breakpoint) {
+        DEBUG_CODE_COMMENT("check hook on function call");
+        Register flag = __ GetUnusedRegister(kGpReg).gp();
+        LOAD_INSTANCE_FIELD(flag, HookOnFunctionCallAddress,
+                            kSystemPointerSize);
+        Label no_break;
+        __ Load(LiftoffRegister{flag}, flag, no_reg, 0, LoadType::kI32Load8U,
+                {});
+        // Unary "equal" means "equals zero".
+        __ emit_cond_jump(kEqual, &no_break, kWasmI32, flag);
+        EmitBreakpoint(decoder);
+        __ bind(&no_break);
+      }
+    }
   }
 
   void GenerateOutOfLineCode(OutOfLineCode* ool) {
@@ -597,6 +646,7 @@ class LiftoffCompiler {
       // In this mode, we never generate stack checks.
       DCHECK(!is_stack_check);
       __ CallTrapCallbackForTesting();
+      DEBUG_CODE_COMMENT("leave frame");
       __ LeaveFrame(StackFrame::WASM_COMPILED);
       __ DropStackSlotsAndRet(
           static_cast<uint32_t>(descriptor_->StackParameterCount()));
@@ -606,7 +656,7 @@ class LiftoffCompiler {
     if (!ool->regs_to_save.is_empty()) __ PushRegisters(ool->regs_to_save);
 
     source_position_table_builder_.AddPosition(
-        __ pc_offset(), SourcePosition(ool->position), false);
+        __ pc_offset(), SourcePosition(ool->position), true);
     __ CallRuntimeStub(ool->stub);
     DCHECK_EQ(!debug_sidetable_builder_, !ool->debug_sidetable_entry_builder);
     if (V8_UNLIKELY(ool->debug_sidetable_entry_builder)) {
@@ -623,8 +673,6 @@ class LiftoffCompiler {
   }
 
   void FinishFunction(FullDecoder* decoder) {
-    // All breakpoints (if any) must be emitted by now.
-    DCHECK_NULL(next_breakpoint_ptr_);
     if (DidAssemblerBailout(decoder)) return;
     for (OutOfLineCode& ool : out_of_line_code_) {
       GenerateOutOfLineCode(&ool);
@@ -645,22 +693,52 @@ class LiftoffCompiler {
   }
 
   void NextInstruction(FullDecoder* decoder, WasmOpcode opcode) {
-    if (V8_UNLIKELY(next_breakpoint_ptr_) &&
-        *next_breakpoint_ptr_ == decoder->position()) {
-      ++next_breakpoint_ptr_;
-      if (next_breakpoint_ptr_ == next_breakpoint_end_) {
-        next_breakpoint_ptr_ = next_breakpoint_end_ = nullptr;
+    bool breakpoint = false;
+    if (V8_UNLIKELY(next_breakpoint_ptr_)) {
+      if (*next_breakpoint_ptr_ == 0) {
+        // A single breakpoint at offset 0 indicates stepping.
+        DCHECK_EQ(next_breakpoint_ptr_ + 1, next_breakpoint_end_);
+        if (WasmOpcodes::IsBreakable(opcode)) {
+          breakpoint = true;
+          EmitBreakpoint(decoder);
+        }
+      } else {
+        while (next_breakpoint_ptr_ != next_breakpoint_end_ &&
+               *next_breakpoint_ptr_ < decoder->position()) {
+          // Skip unreachable breakpoints.
+          ++next_breakpoint_ptr_;
+        }
+        if (next_breakpoint_ptr_ == next_breakpoint_end_) {
+          next_breakpoint_ptr_ = next_breakpoint_end_ = nullptr;
+        } else if (*next_breakpoint_ptr_ == decoder->position()) {
+          DCHECK(WasmOpcodes::IsBreakable(opcode));
+          breakpoint = true;
+          EmitBreakpoint(decoder);
+        }
       }
-      EmitBreakpoint();
     }
+    // Potentially generate the source position to OSR to this instruction.
+    MaybeGenerateExtraSourcePos(decoder, !breakpoint);
     TraceCacheState(decoder);
+#ifdef DEBUG
     SLOW_DCHECK(__ ValidateCacheState());
+    if (WasmOpcodes::IsPrefixOpcode(opcode) &&
+        decoder->pc() + 1 < decoder->end()) {
+      byte op_index = *(decoder->pc() + 1);
+      opcode = static_cast<WasmOpcode>(opcode << 8 | op_index);
+    }
     DEBUG_CODE_COMMENT(WasmOpcodes::OpcodeName(opcode));
+#endif
   }
 
-  void EmitBreakpoint() {
+  void EmitBreakpoint(FullDecoder* decoder) {
     DEBUG_CODE_COMMENT("breakpoint");
-    // TODO(clemensb): Actually emit a breakpoint.
+    DCHECK(env_->debug);
+    source_position_table_builder_.AddPosition(
+        __ pc_offset(), SourcePosition(decoder->position()), false);
+    __ CallRuntimeStub(WasmCode::kWasmDebugBreak);
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kAllowRegisters);
+    safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
   }
 
   void Block(FullDecoder* decoder, Control* block) {}
@@ -780,7 +858,7 @@ class LiftoffCompiler {
 
   enum CCallReturn : bool { kHasReturn = true, kNoReturn = false };
 
-  void GenerateCCall(const LiftoffRegister* result_regs, FunctionSig* sig,
+  void GenerateCCall(const LiftoffRegister* result_regs, const FunctionSig* sig,
                      ValueType out_argument_type,
                      const LiftoffRegister* arg_regs,
                      ExternalReference ext_ref) {
@@ -790,17 +868,17 @@ class LiftoffCompiler {
     // Store arguments on our stack, then align the stack for calling to C.
     int param_bytes = 0;
     for (ValueType param_type : sig->parameters()) {
-      param_bytes += ValueTypes::MemSize(param_type);
+      param_bytes += param_type.element_size_bytes();
     }
     int out_arg_bytes = out_argument_type == kWasmStmt
                             ? 0
-                            : ValueTypes::MemSize(out_argument_type);
+                            : out_argument_type.element_size_bytes();
     int stack_bytes = std::max(param_bytes, out_arg_bytes);
     __ CallC(sig, arg_regs, result_regs, out_argument_type, stack_bytes,
              ext_ref);
   }
 
-  template <ValueType src_type, ValueType result_type, class EmitFn>
+  template <ValueType::Kind src_type, ValueType::Kind result_type, class EmitFn>
   void EmitUnOp(EmitFn fn) {
     constexpr RegClass src_rc = reg_class_for(src_type);
     constexpr RegClass result_rc = reg_class_for(result_type);
@@ -809,25 +887,25 @@ class LiftoffCompiler {
                               ? __ GetUnusedRegister(result_rc, {src})
                               : __ GetUnusedRegister(result_rc);
     fn(dst, src);
-    __ PushRegister(result_type, dst);
+    __ PushRegister(ValueType(result_type), dst);
   }
 
-  template <ValueType type>
+  template <ValueType::Kind type>
   void EmitFloatUnOpWithCFallback(
       bool (LiftoffAssembler::*emit_fn)(DoubleRegister, DoubleRegister),
       ExternalReference (*fallback_fn)()) {
     auto emit_with_c_fallback = [=](LiftoffRegister dst, LiftoffRegister src) {
       if ((asm_.*emit_fn)(dst.fp(), src.fp())) return;
       ExternalReference ext_ref = fallback_fn();
-      ValueType sig_reps[] = {type};
+      ValueType sig_reps[] = {ValueType(type)};
       FunctionSig sig(0, 1, sig_reps);
-      GenerateCCall(&dst, &sig, type, &src, ext_ref);
+      GenerateCCall(&dst, &sig, ValueType(type), &src, ext_ref);
     };
     EmitUnOp<type, type>(emit_with_c_fallback);
   }
 
   enum TypeConversionTrapping : bool { kCanTrap = true, kNoTrap = false };
-  template <ValueType dst_type, ValueType src_type,
+  template <ValueType::Kind dst_type, ValueType::Kind src_type,
             TypeConversionTrapping can_trap>
   void EmitTypeConversion(WasmOpcode opcode, ExternalReference (*fallback_fn)(),
                           WasmCodePosition trap_position) {
@@ -846,54 +924,55 @@ class LiftoffCompiler {
       ExternalReference ext_ref = fallback_fn();
       if (can_trap) {
         // External references for potentially trapping conversions return int.
-        ValueType sig_reps[] = {kWasmI32, src_type};
+        ValueType sig_reps[] = {kWasmI32, ValueType(src_type)};
         FunctionSig sig(1, 1, sig_reps);
         LiftoffRegister ret_reg =
             __ GetUnusedRegister(kGpReg, LiftoffRegList::ForRegs(dst));
         LiftoffRegister dst_regs[] = {ret_reg, dst};
-        GenerateCCall(dst_regs, &sig, dst_type, &src, ext_ref);
+        GenerateCCall(dst_regs, &sig, ValueType(dst_type), &src, ext_ref);
         __ emit_cond_jump(kEqual, trap, kWasmI32, ret_reg.gp());
       } else {
-        ValueType sig_reps[] = {src_type};
+        ValueType sig_reps[] = {ValueType(src_type)};
         FunctionSig sig(0, 1, sig_reps);
-        GenerateCCall(&dst, &sig, dst_type, &src, ext_ref);
+        GenerateCCall(&dst, &sig, ValueType(dst_type), &src, ext_ref);
       }
     }
-    __ PushRegister(dst_type, dst);
+    __ PushRegister(ValueType(dst_type), dst);
   }
 
   void UnOp(FullDecoder* decoder, WasmOpcode opcode, const Value& value,
             Value* result) {
 #define CASE_I32_UNOP(opcode, fn)                       \
   case kExpr##opcode:                                   \
-    EmitUnOp<kWasmI32, kWasmI32>(                       \
+    EmitUnOp<ValueType::kI32, ValueType::kI32>(         \
         [=](LiftoffRegister dst, LiftoffRegister src) { \
           __ emit_##fn(dst.gp(), src.gp());             \
         });                                             \
     break;
 #define CASE_I64_UNOP(opcode, fn)                       \
   case kExpr##opcode:                                   \
-    EmitUnOp<kWasmI64, kWasmI64>(                       \
+    EmitUnOp<ValueType::kI64, ValueType::kI64>(         \
         [=](LiftoffRegister dst, LiftoffRegister src) { \
           __ emit_##fn(dst, src);                       \
         });                                             \
     break;
 #define CASE_FLOAT_UNOP(opcode, type, fn)               \
   case kExpr##opcode:                                   \
-    EmitUnOp<kWasm##type, kWasm##type>(                 \
+    EmitUnOp<ValueType::k##type, ValueType::k##type>(   \
         [=](LiftoffRegister dst, LiftoffRegister src) { \
           __ emit_##fn(dst.fp(), src.fp());             \
         });                                             \
     break;
-#define CASE_FLOAT_UNOP_WITH_CFALLBACK(opcode, type, fn)                    \
-  case kExpr##opcode:                                                       \
-    EmitFloatUnOpWithCFallback<kWasm##type>(&LiftoffAssembler::emit_##fn,   \
-                                            &ExternalReference::wasm_##fn); \
+#define CASE_FLOAT_UNOP_WITH_CFALLBACK(opcode, type, fn)              \
+  case kExpr##opcode:                                                 \
+    EmitFloatUnOpWithCFallback<ValueType::k##type>(                   \
+        &LiftoffAssembler::emit_##fn, &ExternalReference::wasm_##fn); \
     break;
 #define CASE_TYPE_CONVERSION(opcode, dst_type, src_type, ext_ref, can_trap) \
   case kExpr##opcode:                                                       \
-    EmitTypeConversion<kWasm##dst_type, kWasm##src_type, can_trap>(         \
-        kExpr##opcode, ext_ref, can_trap ? decoder->position() : 0);        \
+    EmitTypeConversion<ValueType::k##dst_type, ValueType::k##src_type,      \
+                       can_trap>(kExpr##opcode, ext_ref,                    \
+                                 can_trap ? decoder->position() : 0);       \
     break;
     switch (opcode) {
       CASE_I32_UNOP(I32Clz, i32_clz)
@@ -959,19 +1038,19 @@ class LiftoffCompiler {
           outstanding_op_ = kExprI32Eqz;
           break;
         }
-        EmitUnOp<kWasmI32, kWasmI32>(
+        EmitUnOp<ValueType::kI32, ValueType::kI32>(
             [=](LiftoffRegister dst, LiftoffRegister src) {
               __ emit_i32_eqz(dst.gp(), src.gp());
             });
         break;
       case kExprI64Eqz:
-        EmitUnOp<kWasmI64, kWasmI32>(
+        EmitUnOp<ValueType::kI64, ValueType::kI32>(
             [=](LiftoffRegister dst, LiftoffRegister src) {
               __ emit_i64_eqz(dst.gp(), src);
             });
         break;
       case kExprI32Popcnt:
-        EmitUnOp<kWasmI32, kWasmI32>(
+        EmitUnOp<ValueType::kI32, ValueType::kI32>(
             [=](LiftoffRegister dst, LiftoffRegister src) {
               if (__ emit_i32_popcnt(dst.gp(), src.gp())) return;
               ValueType sig_i_i_reps[] = {kWasmI32, kWasmI32};
@@ -981,7 +1060,7 @@ class LiftoffCompiler {
             });
         break;
       case kExprI64Popcnt:
-        EmitUnOp<kWasmI64, kWasmI64>(
+        EmitUnOp<ValueType::kI64, ValueType::kI64>(
             [=](LiftoffRegister dst, LiftoffRegister src) {
               if (__ emit_i64_popcnt(dst, src)) return;
               // The c function returns i32. We will zero-extend later.
@@ -1015,8 +1094,8 @@ class LiftoffCompiler {
 #undef CASE_TYPE_CONVERSION
   }
 
-  template <ValueType src_type, ValueType result_type, typename EmitFn,
-            typename EmitFnImm>
+  template <ValueType::Kind src_type, ValueType::Kind result_type,
+            typename EmitFn, typename EmitFnImm>
   void EmitBinOpImm(EmitFn fn, EmitFnImm fnImm) {
     static constexpr RegClass src_rc = reg_class_for(src_type);
     static constexpr RegClass result_rc = reg_class_for(result_type);
@@ -1033,7 +1112,7 @@ class LiftoffCompiler {
                                 : __ GetUnusedRegister(result_rc);
 
       fnImm(dst, lhs, imm);
-      __ PushRegister(result_type, dst);
+      __ PushRegister(ValueType(result_type), dst);
     } else {
       // The RHS was not an immediate.
       LiftoffRegister rhs = __ PopToRegister();
@@ -1042,11 +1121,12 @@ class LiftoffCompiler {
                                 ? __ GetUnusedRegister(result_rc, {lhs, rhs})
                                 : __ GetUnusedRegister(result_rc);
       fn(dst, lhs, rhs);
-      __ PushRegister(result_type, dst);
+      __ PushRegister(ValueType(result_type), dst);
     }
   }
 
-  template <ValueType src_type, ValueType result_type, typename EmitFn>
+  template <ValueType::Kind src_type, ValueType::Kind result_type,
+            typename EmitFn>
   void EmitBinOp(EmitFn fn) {
     static constexpr RegClass src_rc = reg_class_for(src_type);
     static constexpr RegClass result_rc = reg_class_for(result_type);
@@ -1056,7 +1136,7 @@ class LiftoffCompiler {
                               ? __ GetUnusedRegister(result_rc, {lhs, rhs})
                               : __ GetUnusedRegister(result_rc);
     fn(dst, lhs, rhs);
-    __ PushRegister(result_type, dst);
+    __ PushRegister(ValueType(result_type), dst);
   }
 
   void EmitDivOrRem64CCall(LiftoffRegister dst, LiftoffRegister lhs,
@@ -1087,13 +1167,13 @@ class LiftoffCompiler {
              const Value& rhs, Value* result) {
 #define CASE_I32_BINOP(opcode, fn)                                           \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasmI32, kWasmI32>(                                    \
+    return EmitBinOp<ValueType::kI32, ValueType::kI32>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_##fn(dst.gp(), lhs.gp(), rhs.gp());                        \
         });
 #define CASE_I32_BINOPI(opcode, fn)                                          \
   case kExpr##opcode:                                                        \
-    return EmitBinOpImm<kWasmI32, kWasmI32>(                                 \
+    return EmitBinOpImm<ValueType::kI32, ValueType::kI32>(                   \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_##fn(dst.gp(), lhs.gp(), rhs.gp());                        \
         },                                                                   \
@@ -1102,13 +1182,13 @@ class LiftoffCompiler {
         });
 #define CASE_I64_BINOP(opcode, fn)                                           \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasmI64, kWasmI64>(                                    \
+    return EmitBinOp<ValueType::kI64, ValueType::kI64>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_##fn(dst, lhs, rhs);                                       \
         });
 #define CASE_I64_BINOPI(opcode, fn)                                          \
   case kExpr##opcode:                                                        \
-    return EmitBinOpImm<kWasmI64, kWasmI64>(                                 \
+    return EmitBinOpImm<ValueType::kI64, ValueType::kI64>(                   \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_##fn(dst, lhs, rhs);                                       \
         },                                                                   \
@@ -1117,7 +1197,7 @@ class LiftoffCompiler {
         });
 #define CASE_FLOAT_BINOP(opcode, type, fn)                                   \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasm##type, kWasm##type>(                              \
+    return EmitBinOp<ValueType::k##type, ValueType::k##type>(                \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_##fn(dst.fp(), lhs.fp(), rhs.fp());                        \
         });
@@ -1129,32 +1209,32 @@ class LiftoffCompiler {
       outstanding_op_ = kExpr##opcode;                                       \
       break;                                                                 \
     }                                                                        \
-    return EmitBinOp<kWasmI32, kWasmI32>(                                    \
+    return EmitBinOp<ValueType::kI32, ValueType::kI32>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           constexpr Condition cond = GetCompareCondition(kExpr##opcode);     \
           __ emit_i32_set_cond(cond, dst.gp(), lhs.gp(), rhs.gp());          \
         });
 #define CASE_I64_CMPOP(opcode, cond)                                         \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasmI64, kWasmI32>(                                    \
+    return EmitBinOp<ValueType::kI64, ValueType::kI32>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_i64_set_cond(cond, dst.gp(), lhs, rhs);                    \
         });
 #define CASE_F32_CMPOP(opcode, cond)                                         \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasmF32, kWasmI32>(                                    \
+    return EmitBinOp<ValueType::kF32, ValueType::kI32>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_f32_set_cond(cond, dst.gp(), lhs.fp(), rhs.fp());          \
         });
 #define CASE_F64_CMPOP(opcode, cond)                                         \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasmF64, kWasmI32>(                                    \
+    return EmitBinOp<ValueType::kF64, ValueType::kI32>(                      \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           __ emit_f64_set_cond(cond, dst.gp(), lhs.fp(), rhs.fp());          \
         });
 #define CASE_I64_SHIFTOP(opcode, fn)                                         \
   case kExpr##opcode:                                                        \
-    return EmitBinOpImm<kWasmI64, kWasmI64>(                                 \
+    return EmitBinOpImm<ValueType::kI64, ValueType::kI64>(                   \
         [=](LiftoffRegister dst, LiftoffRegister src,                        \
             LiftoffRegister amount) {                                        \
           __ emit_##fn(dst, src,                                             \
@@ -1165,7 +1245,7 @@ class LiftoffCompiler {
         });
 #define CASE_CCALL_BINOP(opcode, type, ext_ref_fn)                           \
   case kExpr##opcode:                                                        \
-    return EmitBinOp<kWasm##type, kWasm##type>(                              \
+    return EmitBinOp<ValueType::k##type, ValueType::k##type>(                \
         [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) { \
           LiftoffRegister args[] = {lhs, rhs};                               \
           auto ext_ref = ExternalReference::ext_ref_fn();                    \
@@ -1245,9 +1325,10 @@ class LiftoffCompiler {
       CASE_FLOAT_BINOP(F64Max, F64, f64_max)
       CASE_FLOAT_BINOP(F64CopySign, F64, f64_copysign)
       case kExprI32DivS:
-        EmitBinOp<kWasmI32, kWasmI32>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
+        EmitBinOp<ValueType::kI32, ValueType::kI32>([this, decoder](
+                                                        LiftoffRegister dst,
+                                                        LiftoffRegister lhs,
+                                                        LiftoffRegister rhs) {
           WasmCodePosition position = decoder->position();
           AddOutOfLineTrap(position, WasmCode::kThrowWasmTrapDivByZero);
           // Adding the second trap might invalidate the pointer returned for
@@ -1261,36 +1342,37 @@ class LiftoffCompiler {
         });
         break;
       case kExprI32DivU:
-        EmitBinOp<kWasmI32, kWasmI32>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
-          Label* div_by_zero = AddOutOfLineTrap(
-              decoder->position(), WasmCode::kThrowWasmTrapDivByZero);
-          __ emit_i32_divu(dst.gp(), lhs.gp(), rhs.gp(), div_by_zero);
-        });
+        EmitBinOp<ValueType::kI32, ValueType::kI32>(
+            [this, decoder](LiftoffRegister dst, LiftoffRegister lhs,
+                            LiftoffRegister rhs) {
+              Label* div_by_zero = AddOutOfLineTrap(
+                  decoder->position(), WasmCode::kThrowWasmTrapDivByZero);
+              __ emit_i32_divu(dst.gp(), lhs.gp(), rhs.gp(), div_by_zero);
+            });
         break;
       case kExprI32RemS:
-        EmitBinOp<kWasmI32, kWasmI32>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
-          Label* rem_by_zero = AddOutOfLineTrap(
-              decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
-          __ emit_i32_rems(dst.gp(), lhs.gp(), rhs.gp(), rem_by_zero);
-        });
+        EmitBinOp<ValueType::kI32, ValueType::kI32>(
+            [this, decoder](LiftoffRegister dst, LiftoffRegister lhs,
+                            LiftoffRegister rhs) {
+              Label* rem_by_zero = AddOutOfLineTrap(
+                  decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
+              __ emit_i32_rems(dst.gp(), lhs.gp(), rhs.gp(), rem_by_zero);
+            });
         break;
       case kExprI32RemU:
-        EmitBinOp<kWasmI32, kWasmI32>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
-          Label* rem_by_zero = AddOutOfLineTrap(
-              decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
-          __ emit_i32_remu(dst.gp(), lhs.gp(), rhs.gp(), rem_by_zero);
-        });
+        EmitBinOp<ValueType::kI32, ValueType::kI32>(
+            [this, decoder](LiftoffRegister dst, LiftoffRegister lhs,
+                            LiftoffRegister rhs) {
+              Label* rem_by_zero = AddOutOfLineTrap(
+                  decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
+              __ emit_i32_remu(dst.gp(), lhs.gp(), rhs.gp(), rem_by_zero);
+            });
         break;
       case kExprI64DivS:
-        EmitBinOp<kWasmI64, kWasmI64>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
+        EmitBinOp<ValueType::kI64, ValueType::kI64>([this, decoder](
+                                                        LiftoffRegister dst,
+                                                        LiftoffRegister lhs,
+                                                        LiftoffRegister rhs) {
           WasmCodePosition position = decoder->position();
           AddOutOfLineTrap(position, WasmCode::kThrowWasmTrapDivByZero);
           // Adding the second trap might invalidate the pointer returned for
@@ -1308,9 +1390,10 @@ class LiftoffCompiler {
         });
         break;
       case kExprI64DivU:
-        EmitBinOp<kWasmI64, kWasmI64>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
+        EmitBinOp<ValueType::kI64, ValueType::kI64>([this, decoder](
+                                                        LiftoffRegister dst,
+                                                        LiftoffRegister lhs,
+                                                        LiftoffRegister rhs) {
           Label* div_by_zero = AddOutOfLineTrap(
               decoder->position(), WasmCode::kThrowWasmTrapDivByZero);
           if (!__ emit_i64_divu(dst, lhs, rhs, div_by_zero)) {
@@ -1320,21 +1403,22 @@ class LiftoffCompiler {
         });
         break;
       case kExprI64RemS:
-        EmitBinOp<kWasmI64, kWasmI64>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
-          Label* rem_by_zero = AddOutOfLineTrap(
-              decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
-          if (!__ emit_i64_rems(dst, lhs, rhs, rem_by_zero)) {
-            ExternalReference ext_ref = ExternalReference::wasm_int64_mod();
-            EmitDivOrRem64CCall(dst, lhs, rhs, ext_ref, rem_by_zero);
-          }
-        });
+        EmitBinOp<ValueType::kI64, ValueType::kI64>(
+            [this, decoder](LiftoffRegister dst, LiftoffRegister lhs,
+                            LiftoffRegister rhs) {
+              Label* rem_by_zero = AddOutOfLineTrap(
+                  decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
+              if (!__ emit_i64_rems(dst, lhs, rhs, rem_by_zero)) {
+                ExternalReference ext_ref = ExternalReference::wasm_int64_mod();
+                EmitDivOrRem64CCall(dst, lhs, rhs, ext_ref, rem_by_zero);
+              }
+            });
         break;
       case kExprI64RemU:
-        EmitBinOp<kWasmI64, kWasmI64>([this, decoder](LiftoffRegister dst,
-                                                      LiftoffRegister lhs,
-                                                      LiftoffRegister rhs) {
+        EmitBinOp<ValueType::kI64, ValueType::kI64>([this, decoder](
+                                                        LiftoffRegister dst,
+                                                        LiftoffRegister lhs,
+                                                        LiftoffRegister rhs) {
           Label* rem_by_zero = AddOutOfLineTrap(
               decoder->position(), WasmCode::kThrowWasmTrapRemByZero);
           if (!__ emit_i64_remu(dst, lhs, rhs, rem_by_zero)) {
@@ -1411,6 +1495,7 @@ class LiftoffCompiler {
       return unsupported(decoder, kMultiValue, "multi-return");
     }
     if (num_returns > 0) __ MoveToReturnRegisters(decoder->sig_);
+    DEBUG_CODE_COMMENT("leave frame");
     __ LeaveFrame(StackFrame::WASM_COMPILED);
     __ DropStackSlotsAndRet(
         static_cast<uint32_t>(descriptor_->StackParameterCount()));
@@ -1709,13 +1794,10 @@ class LiftoffCompiler {
   Label* AddOutOfLineTrap(WasmCodePosition position,
                           WasmCode::RuntimeStubId stub, uint32_t pc = 0) {
     DCHECK(FLAG_wasm_bounds_checks);
-    // The pc is needed for memory OOB trap with trap handler enabled. Other
-    // callers should not even compute it.
-    DCHECK_EQ(pc != 0, stub == WasmCode::kThrowWasmTrapMemOutOfBounds &&
-                           env_->use_trap_handler);
 
-    out_of_line_code_.push_back(
-        OutOfLineCode::Trap(stub, position, pc, RegisterDebugSideTableEntry()));
+    out_of_line_code_.push_back(OutOfLineCode::Trap(
+        stub, position, pc,
+        RegisterDebugSideTableEntry(DebugSideTableBuilder::kAssumeSpilling)));
     return out_of_line_code_.back().label.get();
   }
 
@@ -1847,7 +1929,7 @@ class LiftoffCompiler {
     }
 
     source_position_table_builder_.AddPosition(__ pc_offset(),
-                                               SourcePosition(position), false);
+                                               SourcePosition(position), true);
     __ CallRuntimeStub(WasmCode::kWasmTraceMemory);
     safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
 
@@ -1971,14 +2053,13 @@ class LiftoffCompiler {
     WasmMemoryGrowDescriptor descriptor;
     DCHECK_EQ(0, descriptor.GetStackParameterCount());
     DCHECK_EQ(1, descriptor.GetRegisterParameterCount());
-    DCHECK_EQ(ValueTypes::MachineTypeFor(kWasmI32),
-              descriptor.GetParameterType(0));
+    DCHECK_EQ(kWasmI32.machine_type(), descriptor.GetParameterType(0));
 
     Register param_reg = descriptor.GetRegisterParameter(0);
     if (input.gp() != param_reg) __ Move(param_reg, input.gp(), kWasmI32);
 
     __ CallRuntimeStub(WasmCode::kWasmMemoryGrow);
-    RegisterDebugSideTableEntry();
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
     safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
 
     if (kReturnRegister0 != result.gp()) {
@@ -1988,12 +2069,13 @@ class LiftoffCompiler {
     __ PushRegister(kWasmI32, result);
   }
 
-  DebugSideTableBuilder::EntryBuilder* RegisterDebugSideTableEntry() {
+  DebugSideTableBuilder::EntryBuilder* RegisterDebugSideTableEntry(
+      DebugSideTableBuilder::AssumeSpilling assume_spilling) {
     if (V8_LIKELY(!debug_sidetable_builder_)) return nullptr;
     int stack_height = static_cast<int>(__ cache_state()->stack_height());
     return debug_sidetable_builder_->NewEntry(
         __ pc_offset(), __ num_locals(), stack_height,
-        __ cache_state()->stack_state.begin());
+        __ cache_state()->stack_state.begin(), assume_spilling);
   }
 
   void CallDirect(FullDecoder* decoder,
@@ -2013,6 +2095,11 @@ class LiftoffCompiler {
     call_descriptor =
         GetLoweredCallDescriptor(compilation_zone_, call_descriptor);
 
+    // Place the source position before any stack manipulation, since this will
+    // be used for OSR in debugging.
+    source_position_table_builder_.AddPosition(
+        __ pc_offset(), SourcePosition(decoder->position()), true);
+
     if (imm.index < env_->module->num_imported_functions) {
       // A direct call to an imported function.
       LiftoffRegList pinned;
@@ -2035,25 +2122,21 @@ class LiftoffCompiler {
 
       Register* explicit_instance = &imported_function_ref;
       __ PrepareCall(imm.sig, call_descriptor, &target, explicit_instance);
-      source_position_table_builder_.AddPosition(
-          __ pc_offset(), SourcePosition(decoder->position()), false);
-
       __ CallIndirect(imm.sig, call_descriptor, target);
     } else {
       // A direct call within this module just gets the current instance.
       __ PrepareCall(imm.sig, call_descriptor);
 
-      source_position_table_builder_.AddPosition(
-          __ pc_offset(), SourcePosition(decoder->position()), false);
-
       // Just encode the function index. This will be patched at instantiation.
       Address addr = static_cast<Address>(imm.index);
       __ CallNativeWasmCode(addr);
     }
 
-    RegisterDebugSideTableEntry();
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
     safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
 
+    MaybeGenerateExtraSourcePos(decoder);
+
     __ FinishCall(imm.sig, call_descriptor);
   }
 
@@ -2072,6 +2155,11 @@ class LiftoffCompiler {
       return;
     }
 
+    // Place the source position before any stack manipulation, since this will
+    // be used for OSR in debugging.
+    source_position_table_builder_.AddPosition(
+        __ pc_offset(), SourcePosition(decoder->position()), true);
+
     // Pop the index.
     Register index = __ PopToRegister().gp();
     // If that register is still being used after popping, we move it to another
@@ -2172,9 +2260,6 @@ class LiftoffCompiler {
     __ Load(LiftoffRegister(scratch), table, index, 0, kPointerLoadType,
             pinned);
 
-    source_position_table_builder_.AddPosition(
-        __ pc_offset(), SourcePosition(decoder->position()), false);
-
     auto call_descriptor =
         compiler::GetWasmCallDescriptor(compilation_zone_, imm.sig);
     call_descriptor =
@@ -2184,9 +2269,11 @@ class LiftoffCompiler {
     __ PrepareCall(imm.sig, call_descriptor, &target, explicit_instance);
     __ CallIndirect(imm.sig, call_descriptor, target);
 
-    RegisterDebugSideTableEntry();
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
     safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
 
+    MaybeGenerateExtraSourcePos(decoder);
+
     __ FinishCall(imm.sig, call_descriptor);
   }
 
@@ -2207,22 +2294,240 @@ class LiftoffCompiler {
       return unsupported(decoder, kSimd, "simd");
     }
     switch (opcode) {
+      case wasm::kExprF64x2Splat:
+        EmitUnOp<ValueType::kF64, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister src) {
+              __ emit_f64x2_splat(dst, src);
+            });
+        break;
+      case wasm::kExprF64x2Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f64x2_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprF64x2Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f64x2_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprF64x2Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f64x2_mul(dst, lhs, rhs);
+            });
+        break;
       case wasm::kExprF32x4Splat:
-        EmitUnOp<kWasmF32, kWasmS128>(
+        EmitUnOp<ValueType::kF32, ValueType::kS128>(
             [=](LiftoffRegister dst, LiftoffRegister src) {
               __ emit_f32x4_splat(dst, src);
             });
         break;
+      case wasm::kExprF32x4Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f32x4_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprF32x4Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f32x4_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprF32x4Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_f32x4_mul(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI64x2Splat:
+        EmitUnOp<ValueType::kI64, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister src) {
+              __ emit_i64x2_splat(dst, src);
+            });
+        break;
+      case wasm::kExprI64x2Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i64x2_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI64x2Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i64x2_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI64x2Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i64x2_mul(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI32x4Splat:
+        EmitUnOp<ValueType::kI32, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister src) {
+              __ emit_i32x4_splat(dst, src);
+            });
+        break;
+      case wasm::kExprI32x4Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i32x4_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI32x4Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i32x4_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI32x4Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i32x4_mul(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI16x8Splat:
+        EmitUnOp<ValueType::kI32, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister src) {
+              __ emit_i16x8_splat(dst, src);
+            });
+        break;
+      case wasm::kExprI16x8Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i16x8_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI16x8Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i16x8_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI16x8Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i16x8_mul(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI8x16Splat:
+        EmitUnOp<ValueType::kI32, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister src) {
+              __ emit_i8x16_splat(dst, src);
+            });
+        break;
+      case wasm::kExprI8x16Add:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i8x16_add(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI8x16Sub:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i8x16_sub(dst, lhs, rhs);
+            });
+        break;
+      case wasm::kExprI8x16Mul:
+        EmitBinOp<ValueType::kS128, ValueType::kS128>(
+            [=](LiftoffRegister dst, LiftoffRegister lhs, LiftoffRegister rhs) {
+              __ emit_i8x16_mul(dst, lhs, rhs);
+            });
+        break;
       default:
         unsupported(decoder, kSimd, "simd");
     }
   }
 
+  template <ValueType::Kind src_type, ValueType::Kind result_type,
+            typename EmitFn>
+  void EmitSimdExtractLaneOp(EmitFn fn,
+                             const SimdLaneImmediate<validate>& imm) {
+    static constexpr RegClass src_rc = reg_class_for(src_type);
+    static constexpr RegClass result_rc = reg_class_for(result_type);
+    LiftoffRegister lhs = __ PopToRegister();
+    LiftoffRegister dst = src_rc == result_rc
+                              ? __ GetUnusedRegister(result_rc, {lhs})
+                              : __ GetUnusedRegister(result_rc);
+    fn(dst, lhs, imm.lane);
+    __ PushRegister(ValueType(result_type), dst);
+  }
+
+  template <ValueType::Kind src2_type, typename EmitFn>
+  void EmitSimdReplaceLaneOp(EmitFn fn,
+                             const SimdLaneImmediate<validate>& imm) {
+    static constexpr RegClass src1_rc = reg_class_for(ValueType::kS128);
+    static constexpr RegClass src2_rc = reg_class_for(src2_type);
+    static constexpr RegClass result_rc = reg_class_for(ValueType::kS128);
+    // On backends which need fp pair, src1_rc and result_rc end up being
+    // kFpRegPair, which is != kFpReg, but we still want to pin src2 when it is
+    // kFpReg, since it can overlap with those pairs.
+    static constexpr bool pin_src2 = kNeedS128RegPair && src2_rc == kFpReg;
+
+    // Does not work for arm
+    LiftoffRegister src2 = __ PopToRegister();
+    LiftoffRegister src1 = (src1_rc == src2_rc || pin_src2)
+                               ? __ PopToRegister(LiftoffRegList::ForRegs(src2))
+                               : __
+                                 PopToRegister();
+    LiftoffRegister dst =
+        (src2_rc == result_rc || pin_src2)
+            ? __ GetUnusedRegister(result_rc, {src1},
+                                   LiftoffRegList::ForRegs(src2))
+            : __ GetUnusedRegister(result_rc, {src1});
+    fn(dst, src1, src2, imm.lane);
+    __ PushRegister(kWasmS128, dst);
+  }
+
   void SimdLaneOp(FullDecoder* decoder, WasmOpcode opcode,
                   const SimdLaneImmediate<validate>& imm,
                   const Vector<Value> inputs, Value* result) {
-    unsupported(decoder, kSimd, "simd");
+    if (!CpuFeatures::SupportsWasmSimd128()) {
+      return unsupported(decoder, kSimd, "simd");
+    }
+    switch (opcode) {
+#define CASE_SIMD_EXTRACT_LANE_OP(opcode, type, fn)                           \
+  case wasm::kExpr##opcode:                                                   \
+    EmitSimdExtractLaneOp<ValueType::kS128, ValueType::k##type>(              \
+        [=](LiftoffRegister dst, LiftoffRegister lhs, uint8_t imm_lane_idx) { \
+          __ emit_##fn(dst, lhs, imm_lane_idx);                               \
+        },                                                                    \
+        imm);                                                                 \
+    break;
+      CASE_SIMD_EXTRACT_LANE_OP(F64x2ExtractLane, F64, f64x2_extract_lane)
+      CASE_SIMD_EXTRACT_LANE_OP(F32x4ExtractLane, F32, f32x4_extract_lane)
+      CASE_SIMD_EXTRACT_LANE_OP(I64x2ExtractLane, I64, i64x2_extract_lane)
+      CASE_SIMD_EXTRACT_LANE_OP(I32x4ExtractLane, I32, i32x4_extract_lane)
+      CASE_SIMD_EXTRACT_LANE_OP(I16x8ExtractLaneU, I32, i16x8_extract_lane_u)
+      CASE_SIMD_EXTRACT_LANE_OP(I16x8ExtractLaneS, I32, i16x8_extract_lane_s)
+      CASE_SIMD_EXTRACT_LANE_OP(I8x16ExtractLaneU, I32, i8x16_extract_lane_u)
+      CASE_SIMD_EXTRACT_LANE_OP(I8x16ExtractLaneS, I32, i8x16_extract_lane_s)
+#undef CASE_SIMD_EXTRACT_LANE_OP
+#define CASE_SIMD_REPLACE_LANE_OP(opcode, type, fn)                          \
+  case wasm::kExpr##opcode:                                                  \
+    EmitSimdReplaceLaneOp<ValueType::k##type>(                               \
+        [=](LiftoffRegister dst, LiftoffRegister src1, LiftoffRegister src2, \
+            uint8_t imm_lane_idx) {                                          \
+          __ emit_##fn(dst, src1, src2, imm_lane_idx);                       \
+        },                                                                   \
+        imm);                                                                \
+    break;
+      CASE_SIMD_REPLACE_LANE_OP(F64x2ReplaceLane, F64, f64x2_replace_lane)
+      CASE_SIMD_REPLACE_LANE_OP(F32x4ReplaceLane, F32, f32x4_replace_lane)
+      CASE_SIMD_REPLACE_LANE_OP(I64x2ReplaceLane, I64, i64x2_replace_lane)
+      CASE_SIMD_REPLACE_LANE_OP(I32x4ReplaceLane, I32, i32x4_replace_lane)
+      CASE_SIMD_REPLACE_LANE_OP(I16x8ReplaceLane, I32, i16x8_replace_lane)
+      CASE_SIMD_REPLACE_LANE_OP(I8x16ReplaceLane, I32, i8x16_replace_lane)
+#undef CASE_SIMD_REPLACE_LANE_OP
+      default:
+        unsupported(decoder, kSimd, "simd");
+    }
   }
+
   void Simd8x16ShuffleOp(FullDecoder* decoder,
                          const Simd8x16ShuffleImmediate<validate>& imm,
                          const Value& input0, const Value& input1,
@@ -2326,6 +2631,154 @@ class LiftoffCompiler {
     __ PushRegister(result_type, result);
   }
 
+  void AtomicCompareExchange(FullDecoder* decoder, StoreType type,
+                             const MemoryAccessImmediate<validate>& imm) {
+#ifdef V8_TARGET_ARCH_IA32
+    // With the current implementation we do not have enough registers on ia32
+    // to even get to the platform-specific code. Therefore we bailout early.
+    unsupported(decoder, kAtomics, "AtomicCompareExchange");
+    return;
+#else
+    ValueType result_type = type.value_type();
+    LiftoffRegList pinned;
+    LiftoffRegister new_value = pinned.set(__ PopToRegister());
+    LiftoffRegister expected = pinned.set(__ PopToRegister(pinned));
+    Register index = pinned.set(__ PopToRegister(pinned)).gp();
+    if (BoundsCheckMem(decoder, type.size(), imm.offset, index, pinned,
+                       kDoForceCheck)) {
+      return;
+    }
+    AlignmentCheckMem(decoder, type.size(), imm.offset, index, pinned);
+
+    uint32_t offset = imm.offset;
+    index = AddMemoryMasking(index, &offset, &pinned);
+    Register addr = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    LOAD_INSTANCE_FIELD(addr, MemoryStart, kSystemPointerSize);
+    LiftoffRegister result =
+        pinned.set(__ GetUnusedRegister(reg_class_for(result_type), pinned));
+
+    __ AtomicCompareExchange(addr, index, offset, expected, new_value, result,
+                             type);
+    __ PushRegister(result_type, result);
+#endif
+  }
+
+  template <typename BuiltinDescriptor>
+  compiler::CallDescriptor* GetBuiltinCallDescriptor(Zone* zone) {
+    BuiltinDescriptor interface_descriptor;
+    return compiler::Linkage::GetStubCallDescriptor(
+        zone,                                           // zone
+        interface_descriptor,                           // descriptor
+        interface_descriptor.GetStackParameterCount(),  // stack parameter count
+        compiler::CallDescriptor::kNoFlags,             // flags
+        compiler::Operator::kNoProperties,              // properties
+        StubCallMode::kCallWasmRuntimeStub);            // stub call mode
+  }
+
+  void AtomicWait(FullDecoder* decoder, ValueType type,
+                  const MemoryAccessImmediate<validate>& imm) {
+    LiftoffRegList pinned;
+    Register index_reg = pinned.set(__ PeekToRegister(2, pinned)).gp();
+    if (BoundsCheckMem(decoder, type.element_size_bytes(), imm.offset,
+                       index_reg, pinned, kDoForceCheck)) {
+      return;
+    }
+    AlignmentCheckMem(decoder, type.element_size_bytes(), imm.offset, index_reg,
+                      pinned);
+
+    uint32_t offset = imm.offset;
+    index_reg = AddMemoryMasking(index_reg, &offset, &pinned);
+    if (offset != 0) __ emit_i32_add(index_reg, index_reg, offset);
+
+    LiftoffAssembler::VarState timeout =
+        __ cache_state()->stack_state.end()[-1];
+    LiftoffAssembler::VarState expected_value =
+        __ cache_state()->stack_state.end()[-2];
+    LiftoffAssembler::VarState index = __ cache_state()->stack_state.end()[-3];
+
+    // We have to set the correct register for the index. It may have changed
+    // above in {AddMemoryMasking}.
+    index.MakeRegister(LiftoffRegister(index_reg));
+
+    WasmCode::RuntimeStubId target;
+    compiler::CallDescriptor* call_descriptor;
+    if (type == kWasmI32) {
+      if (kNeedI64RegPair) {
+        target = WasmCode::kWasmI32AtomicWait32;
+        call_descriptor =
+            GetBuiltinCallDescriptor<WasmI32AtomicWait32Descriptor>(
+                compilation_zone_);
+      } else {
+        target = WasmCode::kWasmI32AtomicWait64;
+        call_descriptor =
+            GetBuiltinCallDescriptor<WasmI32AtomicWait64Descriptor>(
+                compilation_zone_);
+      }
+    } else {
+      if (kNeedI64RegPair) {
+        target = WasmCode::kWasmI64AtomicWait32;
+        call_descriptor =
+            GetBuiltinCallDescriptor<WasmI64AtomicWait32Descriptor>(
+                compilation_zone_);
+      } else {
+        target = WasmCode::kWasmI64AtomicWait64;
+        call_descriptor =
+            GetBuiltinCallDescriptor<WasmI64AtomicWait64Descriptor>(
+                compilation_zone_);
+      }
+    }
+
+    ValueType sig_reps[] = {kWasmI32, type, kWasmI64};
+    FunctionSig sig(0, 3, sig_reps);
+
+    __ PrepareBuiltinCall(&sig, call_descriptor,
+                          {index, expected_value, timeout});
+    __ CallRuntimeStub(target);
+
+    // Pop parameters from the value stack.
+    __ cache_state()->stack_state.pop_back(3);
+
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
+    safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
+
+    __ PushRegister(kWasmI32, LiftoffRegister(kReturnRegister0));
+  }
+
+  void AtomicNotify(FullDecoder* decoder,
+                    const MemoryAccessImmediate<validate>& imm) {
+    LiftoffRegList pinned;
+    LiftoffRegister count = pinned.set(__ PopToRegister());
+    Register index = pinned.set(__ PopToRegister(pinned)).gp();
+    if (BoundsCheckMem(decoder, kWasmI32.element_size_bytes(), imm.offset,
+                       index, pinned, kDoForceCheck)) {
+      return;
+    }
+    AlignmentCheckMem(decoder, kWasmI32.element_size_bytes(), imm.offset, index,
+                      pinned);
+
+    uint32_t offset = imm.offset;
+    index = AddMemoryMasking(index, &offset, &pinned);
+    if (offset) __ emit_i32_add(index, index, offset);
+
+    // TODO(ahaas): Use PrepareCall to prepare parameters.
+    __ SpillAllRegisters();
+
+    WasmAtomicNotifyDescriptor descriptor;
+    DCHECK_EQ(0, descriptor.GetStackParameterCount());
+    DCHECK_EQ(2, descriptor.GetRegisterParameterCount());
+    LiftoffAssembler::ParallelRegisterMoveTuple reg_moves[]{
+        {LiftoffRegister(descriptor.GetRegisterParameter(0)),
+         LiftoffRegister(index), kWasmI32},
+        {LiftoffRegister(descriptor.GetRegisterParameter(1)), count, kWasmI32}};
+    __ ParallelRegisterMove(ArrayVector(reg_moves));
+
+    __ CallRuntimeStub(WasmCode::kWasmAtomicNotify);
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
+    safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
+
+    __ PushRegister(kWasmI32, LiftoffRegister(kReturnRegister0));
+  }
+
 #define ATOMIC_STORE_LIST(V)        \
   V(I32AtomicStore, kI32Store)      \
   V(I64AtomicStore, kI64Store)      \
@@ -2344,42 +2797,58 @@ class LiftoffCompiler {
   V(I64AtomicLoad16U, kI64Load16U) \
   V(I64AtomicLoad32U, kI64Load32U)
 
-#define ATOMIC_BINOP_INSTRUCTION_LIST(V) \
-  V(Add, I32AtomicAdd, kI32Store)        \
-  V(Add, I64AtomicAdd, kI64Store)        \
-  V(Add, I32AtomicAdd8U, kI32Store8)     \
-  V(Add, I32AtomicAdd16U, kI32Store16)   \
-  V(Add, I64AtomicAdd8U, kI64Store8)     \
-  V(Add, I64AtomicAdd16U, kI64Store16)   \
-  V(Add, I64AtomicAdd32U, kI64Store32)   \
-  V(Sub, I32AtomicSub, kI32Store)        \
-  V(Sub, I64AtomicSub, kI64Store)        \
-  V(Sub, I32AtomicSub8U, kI32Store8)     \
-  V(Sub, I32AtomicSub16U, kI32Store16)   \
-  V(Sub, I64AtomicSub8U, kI64Store8)     \
-  V(Sub, I64AtomicSub16U, kI64Store16)   \
-  V(Sub, I64AtomicSub32U, kI64Store32)   \
-  V(And, I32AtomicAnd, kI32Store)        \
-  V(And, I64AtomicAnd, kI64Store)        \
-  V(And, I32AtomicAnd8U, kI32Store8)     \
-  V(And, I32AtomicAnd16U, kI32Store16)   \
-  V(And, I64AtomicAnd8U, kI64Store8)     \
-  V(And, I64AtomicAnd16U, kI64Store16)   \
-  V(And, I64AtomicAnd32U, kI64Store32)   \
-  V(Or, I32AtomicOr, kI32Store)          \
-  V(Or, I64AtomicOr, kI64Store)          \
-  V(Or, I32AtomicOr8U, kI32Store8)       \
-  V(Or, I32AtomicOr16U, kI32Store16)     \
-  V(Or, I64AtomicOr8U, kI64Store8)       \
-  V(Or, I64AtomicOr16U, kI64Store16)     \
-  V(Or, I64AtomicOr32U, kI64Store32)     \
-  V(Xor, I32AtomicXor, kI32Store)        \
-  V(Xor, I64AtomicXor, kI64Store)        \
-  V(Xor, I32AtomicXor8U, kI32Store8)     \
-  V(Xor, I32AtomicXor16U, kI32Store16)   \
-  V(Xor, I64AtomicXor8U, kI64Store8)     \
-  V(Xor, I64AtomicXor16U, kI64Store16)   \
-  V(Xor, I64AtomicXor32U, kI64Store32)
+#define ATOMIC_BINOP_INSTRUCTION_LIST(V)         \
+  V(Add, I32AtomicAdd, kI32Store)                \
+  V(Add, I64AtomicAdd, kI64Store)                \
+  V(Add, I32AtomicAdd8U, kI32Store8)             \
+  V(Add, I32AtomicAdd16U, kI32Store16)           \
+  V(Add, I64AtomicAdd8U, kI64Store8)             \
+  V(Add, I64AtomicAdd16U, kI64Store16)           \
+  V(Add, I64AtomicAdd32U, kI64Store32)           \
+  V(Sub, I32AtomicSub, kI32Store)                \
+  V(Sub, I64AtomicSub, kI64Store)                \
+  V(Sub, I32AtomicSub8U, kI32Store8)             \
+  V(Sub, I32AtomicSub16U, kI32Store16)           \
+  V(Sub, I64AtomicSub8U, kI64Store8)             \
+  V(Sub, I64AtomicSub16U, kI64Store16)           \
+  V(Sub, I64AtomicSub32U, kI64Store32)           \
+  V(And, I32AtomicAnd, kI32Store)                \
+  V(And, I64AtomicAnd, kI64Store)                \
+  V(And, I32AtomicAnd8U, kI32Store8)             \
+  V(And, I32AtomicAnd16U, kI32Store16)           \
+  V(And, I64AtomicAnd8U, kI64Store8)             \
+  V(And, I64AtomicAnd16U, kI64Store16)           \
+  V(And, I64AtomicAnd32U, kI64Store32)           \
+  V(Or, I32AtomicOr, kI32Store)                  \
+  V(Or, I64AtomicOr, kI64Store)                  \
+  V(Or, I32AtomicOr8U, kI32Store8)               \
+  V(Or, I32AtomicOr16U, kI32Store16)             \
+  V(Or, I64AtomicOr8U, kI64Store8)               \
+  V(Or, I64AtomicOr16U, kI64Store16)             \
+  V(Or, I64AtomicOr32U, kI64Store32)             \
+  V(Xor, I32AtomicXor, kI32Store)                \
+  V(Xor, I64AtomicXor, kI64Store)                \
+  V(Xor, I32AtomicXor8U, kI32Store8)             \
+  V(Xor, I32AtomicXor16U, kI32Store16)           \
+  V(Xor, I64AtomicXor8U, kI64Store8)             \
+  V(Xor, I64AtomicXor16U, kI64Store16)           \
+  V(Xor, I64AtomicXor32U, kI64Store32)           \
+  V(Exchange, I32AtomicExchange, kI32Store)      \
+  V(Exchange, I64AtomicExchange, kI64Store)      \
+  V(Exchange, I32AtomicExchange8U, kI32Store8)   \
+  V(Exchange, I32AtomicExchange16U, kI32Store16) \
+  V(Exchange, I64AtomicExchange8U, kI64Store8)   \
+  V(Exchange, I64AtomicExchange16U, kI64Store16) \
+  V(Exchange, I64AtomicExchange32U, kI64Store32)
+
+#define ATOMIC_COMPARE_EXCHANGE_LIST(V)       \
+  V(I32AtomicCompareExchange, kI32Store)      \
+  V(I64AtomicCompareExchange, kI64Store)      \
+  V(I32AtomicCompareExchange8U, kI32Store8)   \
+  V(I32AtomicCompareExchange16U, kI32Store16) \
+  V(I64AtomicCompareExchange8U, kI64Store8)   \
+  V(I64AtomicCompareExchange16U, kI64Store16) \
+  V(I64AtomicCompareExchange32U, kI64Store32)
 
   void AtomicOp(FullDecoder* decoder, WasmOpcode opcode, Vector<Value> args,
                 const MemoryAccessImmediate<validate>& imm, Value* result) {
@@ -2407,6 +2876,24 @@ class LiftoffCompiler {
 
       ATOMIC_BINOP_INSTRUCTION_LIST(ATOMIC_BINOP_OP)
 #undef ATOMIC_BINOP_OP
+
+#define ATOMIC_COMPARE_EXCHANGE_OP(name, type)            \
+  case wasm::kExpr##name:                                 \
+    AtomicCompareExchange(decoder, StoreType::type, imm); \
+    break;
+
+      ATOMIC_COMPARE_EXCHANGE_LIST(ATOMIC_COMPARE_EXCHANGE_OP)
+#undef ATOMIC_COMPARE_EXCHANGE_OP
+
+      case kExprI32AtomicWait:
+        AtomicWait(decoder, kWasmI32, imm);
+        break;
+      case kExprI64AtomicWait:
+        AtomicWait(decoder, kWasmI64, imm);
+        break;
+      case kExprAtomicNotify:
+        AtomicNotify(decoder, imm);
+        break;
       default:
         unsupported(decoder, kAtomics, "atomicop");
     }
@@ -2415,53 +2902,284 @@ class LiftoffCompiler {
 #undef ATOMIC_STORE_LIST
 #undef ATOMIC_LOAD_LIST
 #undef ATOMIC_BINOP_INSTRUCTION_LIST
+#undef ATOMIC_COMPARE_EXCHANGE_LIST
+
+  void AtomicFence(FullDecoder* decoder) { __ AtomicFence(); }
 
-  void AtomicFence(FullDecoder* decoder) {
-    unsupported(decoder, kAtomics, "atomic.fence");
-  }
   void MemoryInit(FullDecoder* decoder,
-                  const MemoryInitImmediate<validate>& imm, const Value& dst,
-                  const Value& src, const Value& size) {
-    unsupported(decoder, kBulkMemory, "memory.init");
+                  const MemoryInitImmediate<validate>& imm, const Value&,
+                  const Value&, const Value&) {
+    LiftoffRegList pinned;
+    LiftoffRegister size = pinned.set(__ PopToRegister());
+    LiftoffRegister src = pinned.set(__ PopToRegister(pinned));
+    LiftoffRegister dst = pinned.set(__ PopToRegister(pinned));
+
+    Register instance = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    __ FillInstanceInto(instance);
+
+    LiftoffRegister segment_index =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(segment_index, WasmValue(imm.data_segment_index));
+
+    ExternalReference ext_ref = ExternalReference::wasm_memory_init();
+    ValueType sig_reps[] = {kWasmI32, kPointerValueType, kWasmI32,
+                            kWasmI32, kWasmI32,          kWasmI32};
+    FunctionSig sig(1, 5, sig_reps);
+    LiftoffRegister args[] = {LiftoffRegister(instance), dst, src,
+                              segment_index, size};
+    // We don't need the instance anymore after the call. We can use the
+    // register for the result.
+    LiftoffRegister result(instance);
+    GenerateCCall(&result, &sig, kWasmStmt, args, ext_ref);
+    Label* trap_label = AddOutOfLineTrap(
+        decoder->position(), WasmCode::kThrowWasmTrapMemOutOfBounds);
+    __ emit_cond_jump(kEqual, trap_label, kWasmI32, result.gp());
   }
+
   void DataDrop(FullDecoder* decoder, const DataDropImmediate<validate>& imm) {
-    unsupported(decoder, kBulkMemory, "data.drop");
+    LiftoffRegList pinned;
+
+    Register seg_size_array =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    LOAD_INSTANCE_FIELD(seg_size_array, DataSegmentSizes, kSystemPointerSize);
+
+    LiftoffRegister seg_index =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    // Scale the seg_index for the array access.
+    __ LoadConstant(seg_index,
+                    WasmValue(imm.index << kWasmI32.element_size_log2()));
+
+    // Set the length of the segment to '0' to drop it.
+    LiftoffRegister null_reg = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(null_reg, WasmValue(0));
+    __ Store(seg_size_array, seg_index.gp(), 0, null_reg, StoreType::kI32Store,
+             pinned);
   }
+
   void MemoryCopy(FullDecoder* decoder,
-                  const MemoryCopyImmediate<validate>& imm, const Value& dst,
-                  const Value& src, const Value& size) {
-    unsupported(decoder, kBulkMemory, "memory.copy");
+                  const MemoryCopyImmediate<validate>& imm, const Value&,
+                  const Value&, const Value&) {
+    LiftoffRegList pinned;
+    LiftoffRegister size = pinned.set(__ PopToRegister());
+    LiftoffRegister src = pinned.set(__ PopToRegister(pinned));
+    LiftoffRegister dst = pinned.set(__ PopToRegister(pinned));
+    Register instance = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    __ FillInstanceInto(instance);
+    ExternalReference ext_ref = ExternalReference::wasm_memory_copy();
+    ValueType sig_reps[] = {kWasmI32, kPointerValueType, kWasmI32, kWasmI32,
+                            kWasmI32};
+    FunctionSig sig(1, 4, sig_reps);
+    LiftoffRegister args[] = {LiftoffRegister(instance), dst, src, size};
+    // We don't need the instance anymore after the call. We can use the
+    // register for the result.
+    LiftoffRegister result(instance);
+    GenerateCCall(&result, &sig, kWasmStmt, args, ext_ref);
+    Label* trap_label = AddOutOfLineTrap(
+        decoder->position(), WasmCode::kThrowWasmTrapMemOutOfBounds);
+    __ emit_cond_jump(kEqual, trap_label, kWasmI32, result.gp());
   }
+
   void MemoryFill(FullDecoder* decoder,
-                  const MemoryIndexImmediate<validate>& imm, const Value& dst,
-                  const Value& value, const Value& size) {
-    unsupported(decoder, kBulkMemory, "memory.fill");
+                  const MemoryIndexImmediate<validate>& imm, const Value&,
+                  const Value&, const Value&) {
+    LiftoffRegList pinned;
+    LiftoffRegister size = pinned.set(__ PopToRegister());
+    LiftoffRegister value = pinned.set(__ PopToRegister(pinned));
+    LiftoffRegister dst = pinned.set(__ PopToRegister(pinned));
+    Register instance = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    __ FillInstanceInto(instance);
+    ExternalReference ext_ref = ExternalReference::wasm_memory_fill();
+    ValueType sig_reps[] = {kWasmI32, kPointerValueType, kWasmI32, kWasmI32,
+                            kWasmI32};
+    FunctionSig sig(1, 4, sig_reps);
+    LiftoffRegister args[] = {LiftoffRegister(instance), dst, value, size};
+    // We don't need the instance anymore after the call. We can use the
+    // register for the result.
+    LiftoffRegister result(instance);
+    GenerateCCall(&result, &sig, kWasmStmt, args, ext_ref);
+    Label* trap_label = AddOutOfLineTrap(
+        decoder->position(), WasmCode::kThrowWasmTrapMemOutOfBounds);
+    __ emit_cond_jump(kEqual, trap_label, kWasmI32, result.gp());
   }
+
   void TableInit(FullDecoder* decoder, const TableInitImmediate<validate>& imm,
                  Vector<Value> args) {
-    unsupported(decoder, kBulkMemory, "table.init");
+    LiftoffRegList pinned;
+    LiftoffRegister table_index_reg =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+
+#if V8_TARGET_ARCH_32_BIT || defined(V8_COMPRESS_POINTERS)
+    WasmValue table_index_val(
+        static_cast<uint32_t>(Smi::FromInt(imm.table.index).ptr()));
+    WasmValue segment_index_val(
+        static_cast<uint32_t>(Smi::FromInt(imm.elem_segment_index).ptr()));
+#else
+    WasmValue table_index_val(
+        static_cast<uint64_t>(Smi::FromInt(imm.table.index).ptr()));
+    WasmValue segment_index_val(
+        static_cast<uint64_t>(Smi::FromInt(imm.elem_segment_index).ptr()));
+#endif
+    __ LoadConstant(table_index_reg, table_index_val);
+    LiftoffAssembler::VarState table_index(kPointerValueType, table_index_reg,
+                                           0);
+
+    LiftoffRegister segment_index_reg =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(segment_index_reg, segment_index_val);
+    LiftoffAssembler::VarState segment_index(kPointerValueType,
+                                             segment_index_reg, 0);
+
+    LiftoffAssembler::VarState size = __ cache_state()->stack_state.end()[-1];
+    LiftoffAssembler::VarState src = __ cache_state()->stack_state.end()[-2];
+    LiftoffAssembler::VarState dst = __ cache_state()->stack_state.end()[-3];
+
+    WasmCode::RuntimeStubId target = WasmCode::kWasmTableInit;
+    compiler::CallDescriptor* call_descriptor =
+        GetBuiltinCallDescriptor<WasmTableInitDescriptor>(compilation_zone_);
+
+    ValueType sig_reps[] = {kWasmI32, kWasmI32, kWasmI32,
+                            table_index_val.type(), segment_index_val.type()};
+    FunctionSig sig(0, 5, sig_reps);
+
+    __ PrepareBuiltinCall(&sig, call_descriptor,
+                          {dst, src, size, table_index, segment_index});
+    __ CallRuntimeStub(target);
+
+    // Pop parameters from the value stack.
+    __ cache_state()->stack_state.pop_back(3);
+
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
+    safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
   }
+
   void ElemDrop(FullDecoder* decoder, const ElemDropImmediate<validate>& imm) {
-    unsupported(decoder, kBulkMemory, "elem.drop");
+    LiftoffRegList pinned;
+    Register seg_size_array =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
+    LOAD_INSTANCE_FIELD(seg_size_array, DroppedElemSegments,
+                        kSystemPointerSize);
+
+    LiftoffRegister seg_index =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(seg_index, WasmValue(imm.index));
+
+    // Set the length of the segment to '0' to drop it.
+    LiftoffRegister one_reg = pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(one_reg, WasmValue(1));
+    __ Store(seg_size_array, seg_index.gp(), 0, one_reg, StoreType::kI32Store,
+             pinned);
   }
+
   void TableCopy(FullDecoder* decoder, const TableCopyImmediate<validate>& imm,
                  Vector<Value> args) {
-    unsupported(decoder, kBulkMemory, "table.copy");
+    LiftoffRegList pinned;
+
+#if V8_TARGET_ARCH_32_BIT || defined(V8_COMPRESS_POINTERS)
+    WasmValue table_dst_index_val(
+        static_cast<uint32_t>(Smi::FromInt(imm.table_dst.index).ptr()));
+    WasmValue table_src_index_val(
+        static_cast<uint32_t>(Smi::FromInt(imm.table_src.index).ptr()));
+#else
+    WasmValue table_dst_index_val(
+        static_cast<uint64_t>(Smi::FromInt(imm.table_dst.index).ptr()));
+    WasmValue table_src_index_val(
+        static_cast<uint64_t>(Smi::FromInt(imm.table_src.index).ptr()));
+#endif
+
+    LiftoffRegister table_dst_index_reg =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(table_dst_index_reg, table_dst_index_val);
+    LiftoffAssembler::VarState table_dst_index(kPointerValueType,
+                                               table_dst_index_reg, 0);
+
+    LiftoffRegister table_src_index_reg =
+        pinned.set(__ GetUnusedRegister(kGpReg, pinned));
+    __ LoadConstant(table_src_index_reg, table_src_index_val);
+    LiftoffAssembler::VarState table_src_index(kPointerValueType,
+                                               table_src_index_reg, 0);
+
+    LiftoffAssembler::VarState size = __ cache_state()->stack_state.end()[-1];
+    LiftoffAssembler::VarState src = __ cache_state()->stack_state.end()[-2];
+    LiftoffAssembler::VarState dst = __ cache_state()->stack_state.end()[-3];
+
+    WasmCode::RuntimeStubId target = WasmCode::kWasmTableCopy;
+    compiler::CallDescriptor* call_descriptor =
+        GetBuiltinCallDescriptor<WasmTableCopyDescriptor>(compilation_zone_);
+
+    ValueType sig_reps[] = {kWasmI32, kWasmI32, kWasmI32,
+                            table_dst_index_val.type(),
+                            table_src_index_val.type()};
+    FunctionSig sig(0, 5, sig_reps);
+
+    __ PrepareBuiltinCall(&sig, call_descriptor,
+                          {dst, src, size, table_dst_index, table_src_index});
+    __ CallRuntimeStub(target);
+
+    // Pop parameters from the value stack.
+    __ cache_state()->stack_state.pop_back(3);
+
+    RegisterDebugSideTableEntry(DebugSideTableBuilder::kDidSpill);
+    safepoint_table_builder_.DefineSafepoint(&asm_, Safepoint::kNoLazyDeopt);
   }
+
   void TableGrow(FullDecoder* decoder, const TableIndexImmediate<validate>& imm,
                  const Value& value, const Value& delta, Value* result) {
     unsupported(decoder, kAnyRef, "table.grow");
   }
+
   void TableSize(FullDecoder* decoder, const TableIndexImmediate<validate>& imm,
                  Value* result) {
     unsupported(decoder, kAnyRef, "table.size");
   }
+
   void TableFill(FullDecoder* decoder, const TableIndexImmediate<validate>& imm,
                  const Value& start, const Value& value, const Value& count) {
     unsupported(decoder, kAnyRef, "table.fill");
   }
 
  private:
+  // Emit additional source positions for return addresses. Used by debugging to
+  // OSR frames with different sets of breakpoints.
+  void MaybeGenerateExtraSourcePos(Decoder* decoder,
+                                   bool emit_breakpoint_position = false) {
+    if (V8_LIKELY(next_extra_source_pos_ptr_ == nullptr)) return;
+    int position = static_cast<int>(decoder->position());
+    while (*next_extra_source_pos_ptr_ < position) {
+      ++next_extra_source_pos_ptr_;
+      if (next_extra_source_pos_ptr_ == next_extra_source_pos_end_) {
+        next_extra_source_pos_ptr_ = next_extra_source_pos_end_ = nullptr;
+        return;
+      }
+    }
+    if (*next_extra_source_pos_ptr_ != position) return;
+    if (emit_breakpoint_position) {
+      // Removing a breakpoint while paused on that breakpoint will OSR the
+      // return address as follows:
+      //   pos  instr
+      //   0    foo
+      //   1    call WasmDebugBreak
+      //   1    bar  // top frame return address
+      // becomes:
+      //   pos  instr
+      //   0    foo
+      //   1    nop  // top frame return address
+      //        bar
+      // {WasmCompiledFrame::position} would then return "0" as the source
+      // position of the top frame instead of "1".  This is fixed by explicitly
+      // emitting the missing position before the return address, with a nop so
+      // that code offsets do not collide.
+      source_position_table_builder_.AddPosition(
+          __ pc_offset(), SourcePosition(decoder->position()), false);
+      __ nop();
+    }
+    source_position_table_builder_.AddPosition(
+        __ pc_offset(), SourcePosition(decoder->position()), true);
+    // Add a nop here, such that following code has another
+    // PC and does not collide with the source position recorded above.
+    // TODO(thibaudm/clemens): Remove this.
+    __ nop();
+  }
+
   static constexpr WasmOpcode kNoOutstandingOp = kExprUnreachable;
 
   LiftoffAssembler asm_;
@@ -2487,8 +3205,13 @@ class LiftoffCompiler {
   uint32_t pc_offset_stack_frame_construction_ = 0;
   // For emitting breakpoint, we store a pointer to the position of the next
   // breakpoint, and a pointer after the list of breakpoints as end marker.
+  // A single breakpoint at offset 0 indicates that we should prepare the
+  // function for stepping by flooding it with breakpoints.
   int* next_breakpoint_ptr_ = nullptr;
   int* next_breakpoint_end_ = nullptr;
+  // Use a similar approach to generate additional source positions.
+  int* next_extra_source_pos_ptr_ = nullptr;
+  int* next_extra_source_pos_end_ = nullptr;
 
   bool has_outstanding_op() const {
     return outstanding_op_ != kNoOutstandingOp;
@@ -2517,7 +3240,9 @@ class LiftoffCompiler {
 WasmCompilationResult ExecuteLiftoffCompilation(
     AccountingAllocator* allocator, CompilationEnv* env,
     const FunctionBody& func_body, int func_index, Counters* counters,
-    WasmFeatures* detected, Vector<int> breakpoints) {
+    WasmFeatures* detected, Vector<int> breakpoints,
+    std::unique_ptr<DebugSideTable>* debug_sidetable,
+    Vector<int> extra_source_pos) {
   int func_body_size = static_cast<int>(func_body.end - func_body.start);
   TRACE_EVENT2(TRACE_DISABLED_BY_DEFAULT("v8.wasm"),
                "ExecuteLiftoffCompilation", "func_index", func_index,
@@ -2535,11 +3260,16 @@ WasmCompilationResult ExecuteLiftoffCompilation(
   // generation.
   std::unique_ptr<wasm::WasmInstructionBuffer> instruction_buffer =
       wasm::WasmInstructionBuffer::New(128 + code_size_estimate * 4 / 3);
-  DebugSideTableBuilder* const kNoDebugSideTable = nullptr;
+  std::unique_ptr<DebugSideTableBuilder> debug_sidetable_builder;
+  // If we are emitting breakpoints, we should also emit the debug side table.
+  DCHECK_IMPLIES(!breakpoints.empty(), debug_sidetable != nullptr);
+  if (debug_sidetable) {
+    debug_sidetable_builder = std::make_unique<DebugSideTableBuilder>();
+  }
   WasmFullDecoder<Decoder::kValidate, LiftoffCompiler> decoder(
       &zone, env->module, env->enabled_features, detected, func_body,
       call_descriptor, env, &zone, instruction_buffer->CreateView(),
-      kNoDebugSideTable, breakpoints);
+      debug_sidetable_builder.get(), breakpoints, extra_source_pos);
   decoder.Decode();
   liftoff_compile_time_scope.reset();
   LiftoffCompiler* compiler = &decoder.interface();
@@ -2556,30 +3286,34 @@ WasmCompilationResult ExecuteLiftoffCompilation(
     counters->liftoff_bailout_reasons()->AddSample(
         static_cast<int>(compiler->bailout_reason()));
     if (compiler->did_bailout()) {
-      // Liftoff compilation failed.
       counters->liftoff_unsupported_functions()->Increment();
-      return WasmCompilationResult{};
+    } else {
+      counters->liftoff_compiled_functions()->Increment();
     }
-
-    counters->liftoff_compiled_functions()->Increment();
   }
 
+  if (compiler->did_bailout()) return WasmCompilationResult{};
+
   WasmCompilationResult result;
   compiler->GetCode(&result.code_desc);
   result.instr_buffer = instruction_buffer->ReleaseBuffer();
   result.source_positions = compiler->GetSourcePositionTable();
-  result.protected_instructions = compiler->GetProtectedInstructions();
+  result.protected_instructions_data = compiler->GetProtectedInstructionsData();
   result.frame_slot_count = compiler->GetTotalFrameSlotCount();
   result.tagged_parameter_slots = call_descriptor->GetTaggedParameterSlots();
+  result.func_index = func_index;
   result.result_tier = ExecutionTier::kLiftoff;
+  if (debug_sidetable) {
+    *debug_sidetable = debug_sidetable_builder->GenerateDebugSideTable();
+  }
 
   DCHECK(result.succeeded());
   return result;
 }
 
-DebugSideTable GenerateLiftoffDebugSideTable(AccountingAllocator* allocator,
-                                             CompilationEnv* env,
-                                             const FunctionBody& func_body) {
+std::unique_ptr<DebugSideTable> GenerateLiftoffDebugSideTable(
+    AccountingAllocator* allocator, CompilationEnv* env,
+    const FunctionBody& func_body) {
   Zone zone(allocator, "LiftoffDebugSideTableZone");
   auto call_descriptor = compiler::GetWasmCallDescriptor(&zone, func_body.sig);
   DebugSideTableBuilder debug_sidetable_builder;
diff --git a/deps/v8/src/wasm/baseline/liftoff-compiler.h b/deps/v8/src/wasm/baseline/liftoff-compiler.h
index fba92146e1..863fa7ee07 100644
--- a/deps/v8/src/wasm/baseline/liftoff-compiler.h
+++ b/deps/v8/src/wasm/baseline/liftoff-compiler.h
@@ -54,9 +54,11 @@ enum LiftoffBailoutReason : int8_t {
 
 V8_EXPORT_PRIVATE WasmCompilationResult ExecuteLiftoffCompilation(
     AccountingAllocator*, CompilationEnv*, const FunctionBody&, int func_index,
-    Counters*, WasmFeatures* detected_features, Vector<int> breakpoints = {});
+    Counters*, WasmFeatures* detected_features, Vector<int> breakpoints = {},
+    std::unique_ptr<DebugSideTable>* = nullptr,
+    Vector<int> extra_source_pos = {});
 
-V8_EXPORT_PRIVATE DebugSideTable GenerateLiftoffDebugSideTable(
+V8_EXPORT_PRIVATE std::unique_ptr<DebugSideTable> GenerateLiftoffDebugSideTable(
     AccountingAllocator*, CompilationEnv*, const FunctionBody&);
 
 }  // namespace wasm
diff --git a/deps/v8/src/wasm/baseline/liftoff-register.h b/deps/v8/src/wasm/baseline/liftoff-register.h
index f2d42af7b1..16ad652ade 100644
--- a/deps/v8/src/wasm/baseline/liftoff-register.h
+++ b/deps/v8/src/wasm/baseline/liftoff-register.h
@@ -53,22 +53,26 @@ static inline constexpr bool needs_fp_reg_pair(ValueType type) {
   return kNeedS128RegPair && type == kWasmS128;
 }
 
-static inline constexpr RegClass reg_class_for(ValueType type) {
-  switch (type) {
-    case kWasmF32:
-    case kWasmF64:
+static inline constexpr RegClass reg_class_for(ValueType::Kind kind) {
+  switch (kind) {
+    case ValueType::kF32:
+    case ValueType::kF64:
       return kFpReg;
-    case kWasmI32:
+    case ValueType::kI32:
       return kGpReg;
-    case kWasmI64:
+    case ValueType::kI64:
       return kNeedI64RegPair ? kGpRegPair : kGpReg;
-    case kWasmS128:
+    case ValueType::kS128:
       return kNeedS128RegPair ? kFpRegPair : kFpReg;
     default:
       return kNoReg;  // unsupported type
   }
 }
 
+static inline constexpr RegClass reg_class_for(ValueType type) {
+  return reg_class_for(type.kind());
+}
+
 // Description of LiftoffRegister code encoding.
 // This example uses the ARM architecture, which as of writing has:
 // - 9 GP registers, requiring 4 bits
@@ -155,11 +159,17 @@ class LiftoffRegister {
     DCHECK_EQ(reg, fp());
   }
 
-  static LiftoffRegister from_liftoff_code(uint32_t code) {
-    DCHECK_LE(0, code);
-    DCHECK_GT(kAfterMaxLiftoffRegCode, code);
-    DCHECK_EQ(code, static_cast<storage_t>(code));
-    return LiftoffRegister(code);
+  static LiftoffRegister from_liftoff_code(int code) {
+    LiftoffRegister reg{static_cast<storage_t>(code)};
+    // Check that the code is correct by round-tripping through the
+    // reg-class-specific constructor.
+    DCHECK(
+        (reg.is_gp() && code == LiftoffRegister{reg.gp()}.liftoff_code()) ||
+        (reg.is_fp() && code == LiftoffRegister{reg.fp()}.liftoff_code()) ||
+        (reg.is_gp_pair() &&
+         code == ForPair(reg.low_gp(), reg.high_gp()).liftoff_code()) ||
+        (reg.is_fp_pair() && code == ForFpPair(reg.low_fp()).liftoff_code()));
+    return reg;
   }
 
   static LiftoffRegister from_code(RegClass rc, int code) {
@@ -253,8 +263,8 @@ class LiftoffRegister {
   }
 
   int liftoff_code() const {
-    DCHECK(is_gp() || is_fp());
-    return code_;
+    STATIC_ASSERT(sizeof(int) >= sizeof(storage_t));
+    return static_cast<int>(code_);
   }
 
   RegClass reg_class() const {
diff --git a/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h b/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
index 32215b3df5..8461e0435f 100644
--- a/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
+++ b/deps/v8/src/wasm/baseline/mips/liftoff-assembler-mips.h
@@ -59,20 +59,20 @@ inline MemOperand GetInstanceOperand() { return GetStackSlot(kInstanceOffset); }
 inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,
                  int32_t offset, ValueType type) {
   MemOperand src(base, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->lw(dst.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->lw(dst.low_gp(),
                MemOperand(base, offset + liftoff::kLowWordOffset));
       assm->lw(dst.high_gp(),
                MemOperand(base, offset + liftoff::kHighWordOffset));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->lwc1(dst.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Ldc1(dst.fp(), src);
       break;
     default:
@@ -83,20 +83,20 @@ inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,
 inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
                   LiftoffRegister src, ValueType type) {
   MemOperand dst(base, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->Usw(src.gp(), dst);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->Usw(src.low_gp(),
                 MemOperand(base, offset + liftoff::kLowWordOffset));
       assm->Usw(src.high_gp(),
                 MemOperand(base, offset + liftoff::kHighWordOffset));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->Uswc1(src.fp(), dst, t8);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Usdc1(src.fp(), dst, t8);
       break;
     default:
@@ -105,18 +105,18 @@ inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
 }
 
 inline void push(LiftoffAssembler* assm, LiftoffRegister reg, ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->push(reg.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->Push(reg.high_gp(), reg.low_gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->addiu(sp, sp, -sizeof(float));
       assm->swc1(reg.fp(), MemOperand(sp, 0));
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->addiu(sp, sp, -sizeof(double));
       assm->Sdc1(reg.fp(), MemOperand(sp, 0));
       break;
@@ -298,17 +298,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -318,11 +318,11 @@ bool LiftoffAssembler::NeedsAlignment(ValueType type) {
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       TurboAssembler::li(reg.gp(), Operand(value.to_i32(), rmode));
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       DCHECK(RelocInfo::IsNone(rmode));
       int32_t low_word = value.to_i64();
       int32_t high_word = value.to_i64() >> 32;
@@ -330,10 +330,10 @@ void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
       TurboAssembler::li(reg.high_gp(), Operand(high_word));
       break;
     }
-    case kWasmF32:
+    case ValueType::kF32:
       TurboAssembler::Move(reg.fp(), value.to_f32_boxed().get_bits());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Move(reg.fp(), value.to_f64_boxed().get_bits());
       break;
     default:
@@ -568,6 +568,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { sync(); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -597,18 +612,18 @@ void LiftoffAssembler::Move(DoubleRegister dst, DoubleRegister src,
 void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
   RecordUsedSpillOffset(offset);
   MemOperand dst = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       sw(reg.gp(), dst);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       sw(reg.low_gp(), liftoff::GetHalfStackSlot(offset, kLowWord));
       sw(reg.high_gp(), liftoff::GetHalfStackSlot(offset, kHighWord));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       swc1(reg.fp(), dst);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Sdc1(reg.fp(), dst);
       break;
     default:
@@ -619,14 +634,14 @@ void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
 void LiftoffAssembler::Spill(int offset, WasmValue value) {
   RecordUsedSpillOffset(offset);
   MemOperand dst = liftoff::GetStackSlot(offset);
-  switch (value.type()) {
-    case kWasmI32: {
+  switch (value.type().kind()) {
+    case ValueType::kI32: {
       LiftoffRegister tmp = GetUnusedRegister(kGpReg);
       TurboAssembler::li(tmp.gp(), Operand(value.to_i32()));
       sw(tmp.gp(), dst);
       break;
     }
-    case kWasmI64: {
+    case ValueType::kI64: {
       LiftoffRegister tmp = GetUnusedRegister(kGpRegPair);
 
       int32_t low_word = value.to_i64();
@@ -647,18 +662,18 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
 
 void LiftoffAssembler::Fill(LiftoffRegister reg, int offset, ValueType type) {
   MemOperand src = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       lw(reg.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       lw(reg.low_gp(), liftoff::GetHalfStackSlot(offset, kLowWord));
       lw(reg.high_gp(), liftoff::GetHalfStackSlot(offset, kHighWord));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       lwc1(reg.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Ldc1(reg.fp(), src);
       break;
     default:
@@ -1517,12 +1532,328 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bind(&cont);
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_splat");
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_extract_lane");
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_replace_lane");
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_add");
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_sub");
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
   // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
   // 3a4000 support MSA.
-  bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
+  bailout(kSimd, "emit_f32x4_splat");
+}
+
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_extract_lane");
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_replace_lane");
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_add");
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_sub");
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_splat");
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_extract_lane");
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_replace_lane");
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_add");
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_sub");
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_splat");
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_extract_lane");
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_replace_lane");
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_add");
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_sub");
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_splat");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_extract_lane_u");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_extract_lane_s");
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_replace_lane");
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_add");
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_sub");
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_mul");
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_splat");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_extract_lane_u");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_extract_lane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_replace_lane");
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_add");
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_sub");
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_mul");
 }
 
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
@@ -1595,7 +1926,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   TurboAssembler::DropAndRet(static_cast<int>(num_stack_slots));
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1605,7 +1936,7 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
     liftoff::Store(this, sp, arg_bytes, *args++, param_type);
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -1642,7 +1973,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   Call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   if (target == no_reg) {
@@ -1668,14 +1999,12 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   addiu(sp, sp, size);
 }
 
-void LiftoffAssembler::DebugBreak() { stop(); }
-
 void LiftoffStackSlots::Construct() {
   for (auto& slot : slots_) {
     const LiftoffAssembler::VarState& src = slot.src_;
     switch (src.loc()) {
       case LiftoffAssembler::VarState::kStack: {
-        if (src.type() == kWasmF64) {
+        if (src.type().kind() == ValueType::kF64) {
           DCHECK_EQ(kLowWord, slot.half_);
           asm_->lw(kScratchReg,
                    liftoff::GetHalfStackSlot(slot.src_offset_, kHighWord));
@@ -1687,7 +2016,7 @@ void LiftoffStackSlots::Construct() {
         break;
       }
       case LiftoffAssembler::VarState::kRegister:
-        if (src.type() == kWasmI64) {
+        if (src.type().kind() == ValueType::kI64) {
           liftoff::push(
               asm_, slot.half_ == kLowWord ? src.reg().low() : src.reg().high(),
               kWasmI32);
diff --git a/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h b/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
index 09dd5105bf..a3f8d60680 100644
--- a/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
+++ b/deps/v8/src/wasm/baseline/mips64/liftoff-assembler-mips64.h
@@ -48,17 +48,17 @@ inline MemOperand GetInstanceOperand() { return GetStackSlot(kInstanceOffset); }
 
 inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, MemOperand src,
                  ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->lw(dst.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->ld(dst.gp(), src);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->lwc1(dst.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Ldc1(dst.fp(), src);
       break;
     default:
@@ -69,17 +69,17 @@ inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, MemOperand src,
 inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
                   LiftoffRegister src, ValueType type) {
   MemOperand dst(base, offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->Usw(src.gp(), dst);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->Usd(src.gp(), dst);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->Uswc1(src.fp(), dst, t8);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Usdc1(src.fp(), dst, t8);
       break;
     default:
@@ -88,19 +88,19 @@ inline void Store(LiftoffAssembler* assm, Register base, int32_t offset,
 }
 
 inline void push(LiftoffAssembler* assm, LiftoffRegister reg, ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->daddiu(sp, sp, -kSystemPointerSize);
       assm->sw(reg.gp(), MemOperand(sp, 0));
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->push(reg.gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->daddiu(sp, sp, -kSystemPointerSize);
       assm->swc1(reg.fp(), MemOperand(sp, 0));
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->daddiu(sp, sp, -kSystemPointerSize);
       assm->Sdc1(reg.fp(), MemOperand(sp, 0));
       break;
@@ -256,17 +256,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -276,17 +276,17 @@ bool LiftoffAssembler::NeedsAlignment(ValueType type) {
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       TurboAssembler::li(reg.gp(), Operand(value.to_i32(), rmode));
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       TurboAssembler::li(reg.gp(), Operand(value.to_i64(), rmode));
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       TurboAssembler::Move(reg.fp(), value.to_f32_boxed().get_bits());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Move(reg.fp(), value.to_f64_boxed().get_bits());
       break;
     default:
@@ -484,6 +484,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { sync(); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -514,17 +529,17 @@ void LiftoffAssembler::Move(DoubleRegister dst, DoubleRegister src,
 void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
   RecordUsedSpillOffset(offset);
   MemOperand dst = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       Sw(reg.gp(), dst);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       Sd(reg.gp(), dst);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       Swc1(reg.fp(), dst);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Sdc1(reg.fp(), dst);
       break;
     default:
@@ -535,14 +550,14 @@ void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
 void LiftoffAssembler::Spill(int offset, WasmValue value) {
   RecordUsedSpillOffset(offset);
   MemOperand dst = liftoff::GetStackSlot(offset);
-  switch (value.type()) {
-    case kWasmI32: {
+  switch (value.type().kind()) {
+    case ValueType::kI32: {
       LiftoffRegister tmp = GetUnusedRegister(kGpReg);
       TurboAssembler::li(tmp.gp(), Operand(value.to_i32()));
       sw(tmp.gp(), dst);
       break;
     }
-    case kWasmI64: {
+    case ValueType::kI64: {
       LiftoffRegister tmp = GetUnusedRegister(kGpReg);
       TurboAssembler::li(tmp.gp(), value.to_i64());
       sd(tmp.gp(), dst);
@@ -557,17 +572,17 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
 
 void LiftoffAssembler::Fill(LiftoffRegister reg, int offset, ValueType type) {
   MemOperand src = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       Lw(reg.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       Ld(reg.gp(), src);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       Lwc1(reg.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Ldc1(reg.fp(), src);
       break;
     default:
@@ -1309,12 +1324,328 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bind(&cont);
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_splat");
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_exract_lane");
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_replace_lane");
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_add");
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_sub");
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f64x2_mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
   // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
   // 3a4000 support MSA.
-  bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
+  bailout(kSimd, "emit_f32x4_splat");
+}
+
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_exract_lane");
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_replace_lane");
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_add");
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_sub");
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_f32x4_mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_splat");
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_exract_lane");
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_replace_lane");
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_add");
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_sub");
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i64x2_mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_splat");
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_exract_lane");
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_replace_lane");
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_add");
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_sub");
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i32x4_mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_splat");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_exract_lane_u");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_exract_lane_s");
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_replace_lane");
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_add");
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_sub");
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i16x8_mul");
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_splat");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_exract_lane_u");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_exract_lane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_replace_lane");
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_add");
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_sub");
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  // TODO(mips): Support this on loongson 3a4000. Currently, the main MIPS
+  // CPU, Loongson 3a3000 does not support MSA(simd128), but the upcoming
+  // 3a4000 support MSA.
+  bailout(kSimd, "emit_i8x16_mul");
 }
 
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
@@ -1387,7 +1718,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   TurboAssembler::DropAndRet(static_cast<int>(num_stack_slots));
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1397,7 +1728,7 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
     liftoff::Store(this, sp, arg_bytes, *args++, param_type);
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -1434,7 +1765,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   Call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   if (target == no_reg) {
@@ -1460,8 +1791,6 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   daddiu(sp, sp, size);
 }
 
-void LiftoffAssembler::DebugBreak() { stop(); }
-
 void LiftoffStackSlots::Construct() {
   for (auto& slot : slots_) {
     const LiftoffAssembler::VarState& src = slot.src_;
diff --git a/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h b/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
index 89294877ff..3b5a5f3a40 100644
--- a/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
+++ b/deps/v8/src/wasm/baseline/ppc/liftoff-assembler-ppc.h
@@ -66,17 +66,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -170,6 +170,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { sync(); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -517,11 +532,216 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bailout(kUnsupportedArchitecture, "emit_f64_set_cond");
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2splat");
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2extractlane");
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2replacelane");
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2add");
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2sub");
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4extractlane");
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4replacelane");
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4add");
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4sub");
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2splat");
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2extractlane");
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2replacelane");
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2add");
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2sub");
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4_splat");
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4extractlane");
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4replacelane");
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4add");
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4sub");
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8splat");
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8add");
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8sub");
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8mul");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8extractlane_u");
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8replacelane");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8extractlane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16splat");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16extractlane_u");
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16replacelane");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16extractlane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16add");
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16sub");
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16mul");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }
@@ -546,7 +766,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   bailout(kUnsupportedArchitecture, "DropStackSlotsAndRet");
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -558,7 +778,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   bailout(kUnsupportedArchitecture, "CallNativeWasmCode");
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   bailout(kUnsupportedArchitecture, "CallIndirect");
@@ -576,8 +796,6 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   bailout(kUnsupportedArchitecture, "DeallocateStackSlot");
 }
 
-void LiftoffAssembler::DebugBreak() { stop(); }
-
 void LiftoffStackSlots::Construct() {
   asm_->bailout(kUnsupportedArchitecture, "LiftoffStackSlots::Construct");
 }
diff --git a/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h b/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
index f18c60a1fa..e311677e79 100644
--- a/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
+++ b/deps/v8/src/wasm/baseline/s390/liftoff-assembler-s390.h
@@ -65,17 +65,17 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  switch (type) {
-    case kWasmS128:
-      return ValueTypes::ElementSizeInBytes(type);
+  switch (type.kind()) {
+    case ValueType::kS128:
+      return type.element_size_bytes();
     default:
       return kStackSlotSize;
   }
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) {
-  switch (type) {
-    case kWasmS128:
+  switch (type.kind()) {
+    case ValueType::kS128:
       return true;
     default:
       // No alignment because all other types are kStackSlotSize.
@@ -169,6 +169,21 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
   bailout(kAtomics, "AtomicXor");
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  bailout(kAtomics, "AtomicExchange");
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  bailout(kAtomics, "AtomicCompareExchange");
+}
+
+void LiftoffAssembler::AtomicFence() { bailout(kAtomics, "AtomicFence"); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -521,11 +536,216 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bailout(kUnsupportedArchitecture, "emit_f64_set_cond");
 }
 
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2splat");
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2extractlane");
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2replacelane");
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2add");
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2sub");
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f64x2mul");
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4extractlane");
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4replacelane");
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4add");
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4sub");
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4mul");
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2splat");
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2extractlane");
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2replacelane");
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2add");
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2sub");
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i64x2mul");
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4_splat");
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4extractlane");
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4replacelane");
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4add");
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4sub");
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i32x4mul");
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8splat");
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8add");
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8sub");
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8mul");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8extractlane_u");
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8replacelane");
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i16x8extractlane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16splat");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16extractlane_u");
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16extractlane_s");
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16replacelane");
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16add");
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16sub");
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  bailout(kUnsupportedArchitecture, "emit_i8x16mul");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }
@@ -550,7 +770,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   bailout(kUnsupportedArchitecture, "DropStackSlotsAndRet");
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -562,7 +782,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   bailout(kUnsupportedArchitecture, "CallNativeWasmCode");
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   bailout(kUnsupportedArchitecture, "CallIndirect");
@@ -580,8 +800,6 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   bailout(kUnsupportedArchitecture, "DeallocateStackSlot");
 }
 
-void LiftoffAssembler::DebugBreak() { stop(); }
-
 void LiftoffStackSlots::Construct() {
   asm_->bailout(kUnsupportedArchitecture, "LiftoffStackSlots::Construct");
 }
diff --git a/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h b/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
index e760f275fb..6c58625536 100644
--- a/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
+++ b/deps/v8/src/wasm/baseline/x64/liftoff-assembler-x64.h
@@ -58,19 +58,22 @@ inline Operand GetMemOp(LiftoffAssembler* assm, Register addr, Register offset,
 
 inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Operand src,
                  ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->movl(dst.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->movq(dst.gp(), src);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->Movss(dst.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Movsd(dst.fp(), src);
       break;
+    case ValueType::kS128:
+      assm->Movdqu(dst.fp(), src);
+      break;
     default:
       UNREACHABLE();
   }
@@ -78,17 +81,17 @@ inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Operand src,
 
 inline void Store(LiftoffAssembler* assm, Operand dst, LiftoffRegister src,
                   ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       assm->movl(dst, src.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       assm->movq(dst, src.gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->Movss(dst, src.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->Movsd(dst, src.fp());
       break;
     default:
@@ -97,19 +100,23 @@ inline void Store(LiftoffAssembler* assm, Operand dst, LiftoffRegister src,
 }
 
 inline void push(LiftoffAssembler* assm, LiftoffRegister reg, ValueType type) {
-  switch (type) {
-    case kWasmI32:
-    case kWasmI64:
+  switch (type.kind()) {
+    case ValueType::kI32:
+    case ValueType::kI64:
       assm->pushq(reg.gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       assm->AllocateStackSpace(kSystemPointerSize);
       assm->Movss(Operand(rsp, 0), reg.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       assm->AllocateStackSpace(kSystemPointerSize);
       assm->Movsd(Operand(rsp, 0), reg.fp());
       break;
+    case ValueType::kS128:
+      assm->AllocateStackSpace(kSystemPointerSize * 2);
+      assm->Movdqu(Operand(rsp, 0), reg.fp());
+      break;
     default:
       UNREACHABLE();
   }
@@ -178,32 +185,32 @@ constexpr int LiftoffAssembler::StaticStackFrameSize() {
 }
 
 int LiftoffAssembler::SlotSizeForType(ValueType type) {
-  return ValueTypes::ElementSizeInBytes(type);
+  return type.element_size_bytes();
 }
 
 bool LiftoffAssembler::NeedsAlignment(ValueType type) { return false; }
 
 void LiftoffAssembler::LoadConstant(LiftoffRegister reg, WasmValue value,
                                     RelocInfo::Mode rmode) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       if (value.to_i32() == 0 && RelocInfo::IsNone(rmode)) {
         xorl(reg.gp(), reg.gp());
       } else {
         movl(reg.gp(), Immediate(value.to_i32(), rmode));
       }
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       if (RelocInfo::IsNone(rmode)) {
         TurboAssembler::Set(reg.gp(), value.to_i64());
       } else {
         movq(reg.gp(), Immediate64(value.to_i64(), rmode));
       }
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       TurboAssembler::Move(reg.fp(), value.to_f32_boxed().get_bits());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       TurboAssembler::Move(reg.fp(), value.to_f64_boxed().get_bits());
       break;
     default:
@@ -453,32 +460,41 @@ void LiftoffAssembler::AtomicSub(Register dst_addr, Register offset_reg,
 }
 
 namespace liftoff {
+#define __ lasm->
+// Checks if a register in {possible_uses} uses {reg}. If so, it allocates a
+// replacement register for that use, and moves the content of {reg} to {use}.
+// The replacement register is written into the pointer stored in
+// {possible_uses}.
+inline void ClearRegister(LiftoffAssembler* lasm, Register reg,
+                          std::initializer_list<Register*> possible_uses,
+                          LiftoffRegList pinned) {
+  liftoff::SpillRegisters(lasm, reg);
+  Register replacement = no_reg;
+  for (Register* use : possible_uses) {
+    if (reg != *use) continue;
+    if (replacement == no_reg) {
+      replacement = __ GetUnusedRegister(kGpReg, pinned).gp();
+      __ movq(replacement, reg);
+    }
+    // We cannot leave this loop early. There may be multiple uses of {reg}.
+    *use = replacement;
+  }
+}
+
 inline void AtomicBinop(LiftoffAssembler* lasm,
                         void (Assembler::*opl)(Register, Register),
                         void (Assembler::*opq)(Register, Register),
                         Register dst_addr, Register offset_reg,
                         uint32_t offset_imm, LiftoffRegister value,
                         StoreType type) {
-#define __ lasm->
   DCHECK(!__ cache_state()->is_used(value));
+  Register value_reg = value.gp();
   // The cmpxchg instruction uses rax to store the old value of the
   // compare-exchange primitive. Therefore we have to spill the register and
   // move any use to another register.
-  liftoff::SpillRegisters(lasm, rax);
-  Register value_reg = value.gp();
   LiftoffRegList pinned =
       LiftoffRegList::ForRegs(dst_addr, offset_reg, value_reg);
-  if (pinned.has(rax)) {
-    Register replacement =
-        pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
-    for (Register* reg : {&dst_addr, &offset_reg, &value_reg}) {
-      if (*reg == rax) {
-        *reg = replacement;
-      }
-    }
-    __ movq(replacement, rax);
-  }
-
+  ClearRegister(lasm, rax, {&dst_addr, &offset_reg, &value_reg}, pinned);
   if (__ emit_debug_code() && offset_reg != no_reg) {
     __ AssertZeroExtended(offset_reg);
   }
@@ -566,6 +582,99 @@ void LiftoffAssembler::AtomicXor(Register dst_addr, Register offset_reg,
                        offset_reg, offset_imm, value, type);
 }
 
+void LiftoffAssembler::AtomicExchange(Register dst_addr, Register offset_reg,
+                                      uint32_t offset_imm,
+                                      LiftoffRegister value, StoreType type) {
+  DCHECK(!cache_state()->is_used(value));
+  if (emit_debug_code() && offset_reg != no_reg) {
+    AssertZeroExtended(offset_reg);
+  }
+  Operand dst_op = liftoff::GetMemOp(this, dst_addr, offset_reg, offset_imm);
+  switch (type.value()) {
+    case StoreType::kI32Store8:
+    case StoreType::kI64Store8:
+      xchgb(value.gp(), dst_op);
+      movzxbq(value.gp(), value.gp());
+      break;
+    case StoreType::kI32Store16:
+    case StoreType::kI64Store16:
+      xchgw(value.gp(), dst_op);
+      movzxwq(value.gp(), value.gp());
+      break;
+    case StoreType::kI32Store:
+    case StoreType::kI64Store32:
+      xchgl(value.gp(), dst_op);
+      break;
+    case StoreType::kI64Store:
+      xchgq(value.gp(), dst_op);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+void LiftoffAssembler::AtomicCompareExchange(
+    Register dst_addr, Register offset_reg, uint32_t offset_imm,
+    LiftoffRegister expected, LiftoffRegister new_value, LiftoffRegister result,
+    StoreType type) {
+  Register value_reg = new_value.gp();
+  // The cmpxchg instruction uses rax to store the old value of the
+  // compare-exchange primitive. Therefore we have to spill the register and
+  // move any use to another register.
+  LiftoffRegList pinned =
+      LiftoffRegList::ForRegs(dst_addr, offset_reg, expected, value_reg);
+  liftoff::ClearRegister(this, rax, {&dst_addr, &offset_reg, &value_reg},
+                         pinned);
+  if (expected.gp() != rax) {
+    movq(rax, expected.gp());
+  }
+
+  if (emit_debug_code() && offset_reg != no_reg) {
+    AssertZeroExtended(offset_reg);
+  }
+  Operand dst_op = liftoff::GetMemOp(this, dst_addr, offset_reg, offset_imm);
+
+  lock();
+  switch (type.value()) {
+    case StoreType::kI32Store8:
+    case StoreType::kI64Store8: {
+      cmpxchgb(dst_op, value_reg);
+      movzxbq(result.gp(), rax);
+      break;
+    }
+    case StoreType::kI32Store16:
+    case StoreType::kI64Store16: {
+      cmpxchgw(dst_op, value_reg);
+      movzxwq(result.gp(), rax);
+      break;
+    }
+    case StoreType::kI32Store: {
+      cmpxchgl(dst_op, value_reg);
+      if (result.gp() != rax) {
+        movl(result.gp(), rax);
+      }
+      break;
+    }
+    case StoreType::kI64Store32: {
+      cmpxchgl(dst_op, value_reg);
+      // Zero extension.
+      movl(result.gp(), rax);
+      break;
+    }
+    case StoreType::kI64Store: {
+      cmpxchgq(dst_op, value_reg);
+      if (result.gp() != rax) {
+        movq(result.gp(), rax);
+      }
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+}
+
+void LiftoffAssembler::AtomicFence() { mfence(); }
+
 void LiftoffAssembler::LoadCallerFrameSlot(LiftoffRegister dst,
                                            uint32_t caller_slot_idx,
                                            ValueType type) {
@@ -578,11 +687,11 @@ void LiftoffAssembler::MoveStackValue(uint32_t dst_offset, uint32_t src_offset,
   DCHECK_NE(dst_offset, src_offset);
   Operand dst = liftoff::GetStackSlot(dst_offset);
   Operand src = liftoff::GetStackSlot(src_offset);
-  if (ValueTypes::ElementSizeLog2Of(type) == 2) {
+  if (type.element_size_log2() == 2) {
     movl(kScratchRegister, src);
     movl(dst, kScratchRegister);
   } else {
-    DCHECK_EQ(3, ValueTypes::ElementSizeLog2Of(type));
+    DCHECK_EQ(3, type.element_size_log2());
     movq(kScratchRegister, src);
     movq(dst, kScratchRegister);
   }
@@ -614,20 +723,20 @@ void LiftoffAssembler::Move(DoubleRegister dst, DoubleRegister src,
 void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
   RecordUsedSpillOffset(offset);
   Operand dst = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       movl(dst, reg.gp());
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       movq(dst, reg.gp());
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       Movss(dst, reg.fp());
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       Movsd(dst, reg.fp());
       break;
-    case kWasmS128:
+    case ValueType::kS128:
       Movdqu(dst, reg.fp());
       break;
     default:
@@ -638,11 +747,11 @@ void LiftoffAssembler::Spill(int offset, LiftoffRegister reg, ValueType type) {
 void LiftoffAssembler::Spill(int offset, WasmValue value) {
   RecordUsedSpillOffset(offset);
   Operand dst = liftoff::GetStackSlot(offset);
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       movl(dst, Immediate(value.to_i32()));
       break;
-    case kWasmI64: {
+    case ValueType::kI64: {
       if (is_int32(value.to_i64())) {
         // Sign extend low word.
         movq(dst, Immediate(static_cast<int32_t>(value.to_i64())));
@@ -664,20 +773,20 @@ void LiftoffAssembler::Spill(int offset, WasmValue value) {
 
 void LiftoffAssembler::Fill(LiftoffRegister reg, int offset, ValueType type) {
   Operand src = liftoff::GetStackSlot(offset);
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       movl(reg.gp(), src);
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       movq(reg.gp(), src);
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       Movss(reg.fp(), src);
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       Movsd(reg.fp(), src);
       break;
-    case kWasmS128:
+    case ValueType::kS128:
       Movdqu(reg.fp(), src);
       break;
     default:
@@ -923,16 +1032,16 @@ void LiftoffAssembler::emit_i32_xor(Register dst, Register lhs, int32_t imm) {
 }
 
 namespace liftoff {
-template <ValueType type>
+template <ValueType::Kind type>
 inline void EmitShiftOperation(LiftoffAssembler* assm, Register dst,
                                Register src, Register amount,
                                void (Assembler::*emit_shift)(Register)) {
   // If dst is rcx, compute into the scratch register first, then move to rcx.
   if (dst == rcx) {
-    assm->Move(kScratchRegister, src, type);
-    if (amount != rcx) assm->Move(rcx, amount, type);
+    assm->Move(kScratchRegister, src, ValueType(type));
+    if (amount != rcx) assm->Move(rcx, amount, ValueType(type));
     (assm->*emit_shift)(kScratchRegister);
-    assm->Move(rcx, kScratchRegister, type);
+    assm->Move(rcx, kScratchRegister, ValueType(type));
     return;
   }
 
@@ -944,11 +1053,11 @@ inline void EmitShiftOperation(LiftoffAssembler* assm, Register dst,
         src == rcx || assm->cache_state()->is_used(LiftoffRegister(rcx));
     if (use_scratch) assm->movq(kScratchRegister, rcx);
     if (src == rcx) src = kScratchRegister;
-    assm->Move(rcx, amount, type);
+    assm->Move(rcx, amount, ValueType(type));
   }
 
   // Do the actual shift.
-  if (dst != src) assm->Move(dst, src, type);
+  if (dst != src) assm->Move(dst, src, ValueType(type));
   (assm->*emit_shift)(dst);
 
   // Restore rcx if needed.
@@ -958,8 +1067,8 @@ inline void EmitShiftOperation(LiftoffAssembler* assm, Register dst,
 
 void LiftoffAssembler::emit_i32_shl(Register dst, Register src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI32>(this, dst, src, amount,
-                                        &Assembler::shll_cl);
+  liftoff::EmitShiftOperation<ValueType::kI32>(this, dst, src, amount,
+                                               &Assembler::shll_cl);
 }
 
 void LiftoffAssembler::emit_i32_shl(Register dst, Register src,
@@ -970,8 +1079,8 @@ void LiftoffAssembler::emit_i32_shl(Register dst, Register src,
 
 void LiftoffAssembler::emit_i32_sar(Register dst, Register src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI32>(this, dst, src, amount,
-                                        &Assembler::sarl_cl);
+  liftoff::EmitShiftOperation<ValueType::kI32>(this, dst, src, amount,
+                                               &Assembler::sarl_cl);
 }
 
 void LiftoffAssembler::emit_i32_sar(Register dst, Register src,
@@ -982,8 +1091,8 @@ void LiftoffAssembler::emit_i32_sar(Register dst, Register src,
 
 void LiftoffAssembler::emit_i32_shr(Register dst, Register src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI32>(this, dst, src, amount,
-                                        &Assembler::shrl_cl);
+  liftoff::EmitShiftOperation<ValueType::kI32>(this, dst, src, amount,
+                                               &Assembler::shrl_cl);
 }
 
 void LiftoffAssembler::emit_i32_shr(Register dst, Register src,
@@ -1114,8 +1223,8 @@ void LiftoffAssembler::emit_i64_xor(LiftoffRegister dst, LiftoffRegister lhs,
 
 void LiftoffAssembler::emit_i64_shl(LiftoffRegister dst, LiftoffRegister src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI64>(this, dst.gp(), src.gp(), amount,
-                                        &Assembler::shlq_cl);
+  liftoff::EmitShiftOperation<ValueType::kI64>(this, dst.gp(), src.gp(), amount,
+                                               &Assembler::shlq_cl);
 }
 
 void LiftoffAssembler::emit_i64_shl(LiftoffRegister dst, LiftoffRegister src,
@@ -1126,8 +1235,8 @@ void LiftoffAssembler::emit_i64_shl(LiftoffRegister dst, LiftoffRegister src,
 
 void LiftoffAssembler::emit_i64_sar(LiftoffRegister dst, LiftoffRegister src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI64>(this, dst.gp(), src.gp(), amount,
-                                        &Assembler::sarq_cl);
+  liftoff::EmitShiftOperation<ValueType::kI64>(this, dst.gp(), src.gp(), amount,
+                                               &Assembler::sarq_cl);
 }
 
 void LiftoffAssembler::emit_i64_sar(LiftoffRegister dst, LiftoffRegister src,
@@ -1138,8 +1247,8 @@ void LiftoffAssembler::emit_i64_sar(LiftoffRegister dst, LiftoffRegister src,
 
 void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
                                     Register amount) {
-  liftoff::EmitShiftOperation<kWasmI64>(this, dst.gp(), src.gp(), amount,
-                                        &Assembler::shrq_cl);
+  liftoff::EmitShiftOperation<ValueType::kI64>(this, dst.gp(), src.gp(), amount,
+                                               &Assembler::shrq_cl);
 }
 
 void LiftoffAssembler::emit_i64_shr(LiftoffRegister dst, LiftoffRegister src,
@@ -1681,11 +1790,11 @@ void LiftoffAssembler::emit_cond_jump(Condition cond, Label* label,
                                       ValueType type, Register lhs,
                                       Register rhs) {
   if (rhs != no_reg) {
-    switch (type) {
-      case kWasmI32:
+    switch (type.kind()) {
+      case ValueType::kI32:
         cmpl(lhs, rhs);
         break;
-      case kWasmI64:
+      case ValueType::kI64:
         cmpq(lhs, rhs);
         break;
       default:
@@ -1765,6 +1874,102 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
                                                       rhs);
 }
 
+// TODO(fanchenk): Distinguish mov* if data bypass delay matter.
+namespace liftoff {
+template <void (Assembler::*avx_op)(XMMRegister, XMMRegister, XMMRegister),
+          void (Assembler::*sse_op)(XMMRegister, XMMRegister)>
+void EmitSimdCommutativeBinOp(
+    LiftoffAssembler* assm, LiftoffRegister dst, LiftoffRegister lhs,
+    LiftoffRegister rhs, base::Optional<CpuFeature> feature = base::nullopt) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(assm, AVX);
+    (assm->*avx_op)(dst.fp(), lhs.fp(), rhs.fp());
+    return;
+  }
+
+  base::Optional<CpuFeatureScope> sse_scope;
+  if (feature.has_value()) sse_scope.emplace(assm, *feature);
+
+  if (dst.fp() == rhs.fp()) {
+    (assm->*sse_op)(dst.fp(), lhs.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) (assm->movaps)(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), rhs.fp());
+  }
+}
+
+template <void (Assembler::*avx_op)(XMMRegister, XMMRegister, XMMRegister),
+          void (Assembler::*sse_op)(XMMRegister, XMMRegister)>
+void EmitSimdSub(LiftoffAssembler* assm, LiftoffRegister dst,
+                 LiftoffRegister lhs, LiftoffRegister rhs) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(assm, AVX);
+    (assm->*avx_op)(dst.fp(), lhs.fp(), rhs.fp());
+  } else if (lhs.fp() == rhs.fp()) {
+    assm->pxor(dst.fp(), dst.fp());
+  } else if (dst.fp() == rhs.fp()) {
+    assm->movaps(kScratchDoubleReg, rhs.fp());
+    assm->movaps(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), kScratchDoubleReg);
+  } else {
+    if (dst.fp() != lhs.fp()) assm->movaps(dst.fp(), lhs.fp());
+    (assm->*sse_op)(dst.fp(), rhs.fp());
+  }
+}
+}  // namespace liftoff
+
+void LiftoffAssembler::emit_f64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movddup(dst.fp(), src.fp());
+}
+
+void LiftoffAssembler::emit_f64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Pextrq(kScratchRegister, lhs.fp(), static_cast<int8_t>(imm_lane_idx));
+  Movq(dst.fp(), kScratchRegister);
+}
+
+void LiftoffAssembler::emit_f64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    if (imm_lane_idx == 0) {
+      vpblendw(dst.fp(), src1.fp(), src2.fp(), 0b00001111);
+    } else {
+      vmovlhps(dst.fp(), src1.fp(), src2.fp());
+    }
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    if (imm_lane_idx == 0) {
+      pblendw(dst.fp(), src2.fp(), 0b00001111);
+    } else {
+      movlhps(dst.fp(), src2.fp());
+    }
+  }
+}
+
+void LiftoffAssembler::emit_f64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vaddpd, &Assembler::addpd>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_f64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vsubpd, &Assembler::subpd>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_f64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vmulpd, &Assembler::mulpd>(
+      this, dst, lhs, rhs);
+}
+
 void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
                                         LiftoffRegister src) {
   if (dst.fp() != src.fp()) {
@@ -1773,6 +1978,318 @@ void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
   Shufps(dst.fp(), src.fp(), static_cast<byte>(0));
 }
 
+void LiftoffAssembler::emit_f32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vshufps(dst.fp(), lhs.fp(), lhs.fp(), imm_lane_idx);
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    if (imm_lane_idx != 0) shufps(dst.fp(), dst.fp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_f32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vinsertps(dst.fp(), src1.fp(), src2.fp(), (imm_lane_idx << 4) & 0x30);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    insertps(dst.fp(), src2.fp(), (imm_lane_idx << 4) & 0x30);
+  }
+}
+
+void LiftoffAssembler::emit_f32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vaddps, &Assembler::addps>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_f32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vsubps, &Assembler::subps>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_f32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vmulps, &Assembler::mulps>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movq(dst.fp(), src.gp());
+  Movddup(dst.fp(), dst.fp());
+}
+
+void LiftoffAssembler::emit_i64x2_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Pextrq(dst.gp(), lhs.fp(), static_cast<int8_t>(imm_lane_idx));
+}
+
+void LiftoffAssembler::emit_i64x2_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrq(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrq(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i64x2_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddq, &Assembler::paddq>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubq, &Assembler::psubq>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i64x2_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  static constexpr RegClass tmp_rc = reg_class_for(ValueType::kS128);
+  LiftoffRegister tmp1 =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs));
+  LiftoffRegister tmp2 =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs, tmp1));
+  Movaps(tmp1.fp(), lhs.fp());
+  Movaps(tmp2.fp(), rhs.fp());
+  // Multiply high dword of each qword of left with right.
+  Psrlq(tmp1.fp(), 32);
+  Pmuludq(tmp1.fp(), rhs.fp());
+  // Multiply high dword of each qword of right with left.
+  Psrlq(tmp2.fp(), 32);
+  Pmuludq(tmp2.fp(), lhs.fp());
+  Paddq(tmp2.fp(), tmp1.fp());
+  Psllq(tmp2.fp(), 32);
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpmuludq(dst.fp(), lhs.fp(), rhs.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    pmuludq(dst.fp(), rhs.fp());
+  }
+  Paddq(dst.fp(), tmp2.fp());
+}
+
+void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pshufd(dst.fp(), dst.fp(), static_cast<uint8_t>(0));
+}
+
+void LiftoffAssembler::emit_i32x4_extract_lane(LiftoffRegister dst,
+                                               LiftoffRegister lhs,
+                                               uint8_t imm_lane_idx) {
+  Pextrd(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i32x4_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrd(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrd(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i32x4_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddd, &Assembler::paddd>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i32x4_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubd, &Assembler::psubd>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i32x4_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmulld, &Assembler::pmulld>(
+      this, dst, lhs, rhs, base::Optional<CpuFeature>(SSE4_1));
+}
+
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pshuflw(dst.fp(), dst.fp(), static_cast<uint8_t>(0));
+  Pshufd(dst.fp(), dst.fp(), static_cast<uint8_t>(0));
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrw(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i16x8_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrw(dst.gp(), lhs.fp(), imm_lane_idx);
+  movsxwl(dst.gp(), dst.gp());
+}
+
+void LiftoffAssembler::emit_i16x8_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrw(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrw(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i16x8_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddw, &Assembler::paddw>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i16x8_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubw, &Assembler::psubw>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i16x8_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpmullw, &Assembler::pmullw>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  Movd(dst.fp(), src.gp());
+  Pxor(kScratchDoubleReg, kScratchDoubleReg);
+  Pshufb(dst.fp(), kScratchDoubleReg);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_u(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrb(dst.gp(), lhs.fp(), imm_lane_idx);
+}
+
+void LiftoffAssembler::emit_i8x16_extract_lane_s(LiftoffRegister dst,
+                                                 LiftoffRegister lhs,
+                                                 uint8_t imm_lane_idx) {
+  Pextrb(dst.gp(), lhs.fp(), imm_lane_idx);
+  movsxbl(dst.gp(), dst.gp());
+}
+
+void LiftoffAssembler::emit_i8x16_replace_lane(LiftoffRegister dst,
+                                               LiftoffRegister src1,
+                                               LiftoffRegister src2,
+                                               uint8_t imm_lane_idx) {
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    vpinsrb(dst.fp(), src1.fp(), src2.gp(), imm_lane_idx);
+  } else {
+    CpuFeatureScope scope(this, SSE4_1);
+    if (dst.fp() != src1.fp()) movaps(dst.fp(), src1.fp());
+    pinsrb(dst.fp(), src2.gp(), imm_lane_idx);
+  }
+}
+
+void LiftoffAssembler::emit_i8x16_add(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdCommutativeBinOp<&Assembler::vpaddb, &Assembler::paddb>(
+      this, dst, lhs, rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_sub(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  liftoff::EmitSimdSub<&Assembler::vpsubb, &Assembler::psubb>(this, dst, lhs,
+                                                              rhs);
+}
+
+void LiftoffAssembler::emit_i8x16_mul(LiftoffRegister dst, LiftoffRegister lhs,
+                                      LiftoffRegister rhs) {
+  static constexpr RegClass tmp_rc = reg_class_for(ValueType::kS128);
+  LiftoffRegister tmp =
+      GetUnusedRegister(tmp_rc, LiftoffRegList::ForRegs(dst, lhs, rhs));
+  if (CpuFeatures::IsSupported(AVX)) {
+    CpuFeatureScope scope(this, AVX);
+    // I16x8 view of I8x16
+    // left = AAaa AAaa ... AAaa AAaa
+    // right= BBbb BBbb ... BBbb BBbb
+    // t = 00AA 00AA ... 00AA 00AA
+    // s = 00BB 00BB ... 00BB 00BB
+    vpsrlw(tmp.fp(), lhs.fp(), 8);
+    vpsrlw(kScratchDoubleReg, rhs.fp(), 8);
+    // t = I16x8Mul(t0, t1)
+    //    => __PP __PP ...  __PP  __PP
+    vpmullw(tmp.fp(), tmp.fp(), kScratchDoubleReg);
+    // s = left * 256
+    vpsllw(kScratchDoubleReg, lhs.fp(), 8);
+    // dst = I16x8Mul(left * 256, right)
+    //    => pp__ pp__ ...  pp__  pp__
+    vpmullw(dst.fp(), kScratchDoubleReg, rhs.fp());
+    // dst = I16x8Shr(dst, 8)
+    //    => 00pp 00pp ...  00pp  00pp
+    vpsrlw(dst.fp(), dst.fp(), 8);
+    // t = I16x8Shl(t, 8)
+    //    => PP00 PP00 ...  PP00  PP00
+    vpsllw(tmp.fp(), tmp.fp(), 8);
+    // dst = I16x8Or(dst, t)
+    //    => PPpp PPpp ...  PPpp  PPpp
+    vpor(dst.fp(), dst.fp(), tmp.fp());
+  } else {
+    if (dst.fp() != lhs.fp()) movaps(dst.fp(), lhs.fp());
+    // I16x8 view of I8x16
+    // left = AAaa AAaa ... AAaa AAaa
+    // right= BBbb BBbb ... BBbb BBbb
+    // t = 00AA 00AA ... 00AA 00AA
+    // s = 00BB 00BB ... 00BB 00BB
+    movaps(tmp.fp(), dst.fp());
+    movaps(kScratchDoubleReg, rhs.fp());
+    psrlw(tmp.fp(), 8);
+    psrlw(kScratchDoubleReg, 8);
+    // dst = left * 256
+    psllw(dst.fp(), 8);
+    // t = I16x8Mul(t, s)
+    //    => __PP __PP ...  __PP  __PP
+    pmullw(tmp.fp(), kScratchDoubleReg);
+    // dst = I16x8Mul(left * 256, right)
+    //    => pp__ pp__ ...  pp__  pp__
+    pmullw(dst.fp(), rhs.fp());
+    // t = I16x8Shl(t, 8)
+    //    => PP00 PP00 ...  PP00  PP00
+    psllw(tmp.fp(), 8);
+    // dst = I16x8Shr(dst, 8)
+    //    => 00pp 00pp ...  00pp  00pp
+    psrlw(dst.fp(), 8);
+    // dst = I16x8Or(dst, t)
+    //    => PPpp PPpp ...  PPpp  PPpp
+    por(dst.fp(), tmp.fp());
+  }
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   cmpq(rsp, Operand(limit_address, 0));
   j(below_equal, ool_code);
@@ -1833,7 +2350,7 @@ void LiftoffAssembler::DropStackSlotsAndRet(uint32_t num_stack_slots) {
   ret(static_cast<int>(num_stack_slots * kSystemPointerSize));
 }
 
-void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallC(const wasm::FunctionSig* sig,
                              const LiftoffRegister* args,
                              const LiftoffRegister* rets,
                              ValueType out_argument_type, int stack_bytes,
@@ -1843,7 +2360,7 @@ void LiftoffAssembler::CallC(wasm::FunctionSig* sig,
   int arg_bytes = 0;
   for (ValueType param_type : sig->parameters()) {
     liftoff::Store(this, Operand(rsp, arg_bytes), *args++, param_type);
-    arg_bytes += ValueTypes::MemSize(param_type);
+    arg_bytes += param_type.element_size_bytes();
   }
   DCHECK_LE(arg_bytes, stack_bytes);
 
@@ -1879,7 +2396,7 @@ void LiftoffAssembler::CallNativeWasmCode(Address addr) {
   near_call(addr, RelocInfo::WASM_CALL);
 }
 
-void LiftoffAssembler::CallIndirect(wasm::FunctionSig* sig,
+void LiftoffAssembler::CallIndirect(const wasm::FunctionSig* sig,
                                     compiler::CallDescriptor* call_descriptor,
                                     Register target) {
   if (target == no_reg) {
@@ -1908,8 +2425,6 @@ void LiftoffAssembler::DeallocateStackSlot(uint32_t size) {
   addq(rsp, Immediate(size));
 }
 
-void LiftoffAssembler::DebugBreak() { int3(); }
-
 void LiftoffStackSlots::Construct() {
   for (auto& slot : slots_) {
     const LiftoffAssembler::VarState& src = slot.src_;
@@ -1920,6 +2435,11 @@ void LiftoffStackSlots::Construct() {
           // extended.
           asm_->movl(kScratchRegister, liftoff::GetStackSlot(slot.src_offset_));
           asm_->pushq(kScratchRegister);
+        } else if (src.type() == kWasmS128) {
+          // Since offsets are subtracted from sp, we need a smaller offset to
+          // push the top of a s128 value.
+          asm_->pushq(liftoff::GetStackSlot(slot.src_offset_ - 8));
+          asm_->pushq(liftoff::GetStackSlot(slot.src_offset_));
         } else {
           // For all other types, just push the whole (8-byte) stack slot.
           // This is also ok for f32 values (even though we copy 4 uninitialized
diff --git a/deps/v8/src/wasm/c-api.cc b/deps/v8/src/wasm/c-api.cc
index 8fdf180182..d098a5f57f 100644
--- a/deps/v8/src/wasm/c-api.cc
+++ b/deps/v8/src/wasm/c-api.cc
@@ -62,18 +62,18 @@ auto ReadLebU64(const byte_t** pos) -> uint64_t {
 }
 
 ValKind V8ValueTypeToWasm(i::wasm::ValueType v8_valtype) {
-  switch (v8_valtype) {
-    case i::wasm::kWasmI32:
+  switch (v8_valtype.kind()) {
+    case i::wasm::ValueType::kI32:
       return I32;
-    case i::wasm::kWasmI64:
+    case i::wasm::ValueType::kI64:
       return I64;
-    case i::wasm::kWasmF32:
+    case i::wasm::ValueType::kF32:
       return F32;
-    case i::wasm::kWasmF64:
+    case i::wasm::ValueType::kF64:
       return F64;
-    case i::wasm::kWasmFuncRef:
+    case i::wasm::ValueType::kFuncRef:
       return FUNCREF;
-    case i::wasm::kWasmAnyRef:
+    case i::wasm::ValueType::kAnyRef:
       return ANYREF;
     default:
       // TODO(wasm+): support new value types
@@ -1212,7 +1212,7 @@ namespace {
 class SignatureHelper : public i::AllStatic {
  public:
   // Use an invalid type as a marker separating params and results.
-  static const i::wasm::ValueType kMarker = i::wasm::kWasmStmt;
+  static constexpr i::wasm::ValueType kMarker = i::wasm::kWasmStmt;
 
   static i::Handle<i::PodArray<i::wasm::ValueType>> Serialize(
       i::Isolate* isolate, FuncType* type) {
@@ -1271,6 +1271,10 @@ class SignatureHelper : public i::AllStatic {
   }
 };
 
+// Explicit instantiation makes the linker happy for component builds of
+// wasm_api_tests.
+constexpr i::wasm::ValueType SignatureHelper::kMarker;
+
 auto make_func(Store* store_abs, FuncData* data) -> own<Func> {
   auto store = impl(store_abs);
   i::Isolate* isolate = store->i_isolate();
@@ -1322,7 +1326,7 @@ auto Func::param_arity() const -> size_t {
   DCHECK(i::WasmExportedFunction::IsWasmExportedFunction(*func));
   i::Handle<i::WasmExportedFunction> function =
       i::Handle<i::WasmExportedFunction>::cast(func);
-  i::wasm::FunctionSig* sig =
+  const i::wasm::FunctionSig* sig =
       function->instance().module()->functions[function->function_index()].sig;
   return sig->parameter_count();
 }
@@ -1335,7 +1339,7 @@ auto Func::result_arity() const -> size_t {
   DCHECK(i::WasmExportedFunction::IsWasmExportedFunction(*func));
   i::Handle<i::WasmExportedFunction> function =
       i::Handle<i::WasmExportedFunction>::cast(func);
-  i::wasm::FunctionSig* sig =
+  const i::wasm::FunctionSig* sig =
       function->instance().module()->functions[function->function_index()].sig;
   return sig->return_count();
 }
@@ -1375,7 +1379,7 @@ i::Address CallTargetFromCache(i::Object cached_call_target) {
 
 void PrepareFunctionData(i::Isolate* isolate,
                          i::Handle<i::WasmExportedFunctionData> function_data,
-                         i::wasm::FunctionSig* sig) {
+                         const i::wasm::FunctionSig* sig) {
   // If the data is already populated, return immediately.
   if (!function_data->c_wrapper_code().IsSmi()) return;
   // Compile wrapper code.
@@ -1393,29 +1397,29 @@ void PrepareFunctionData(i::Isolate* isolate,
   function_data->set_wasm_call_target(*call_target);
 }
 
-void PushArgs(i::wasm::FunctionSig* sig, const Val args[],
+void PushArgs(const i::wasm::FunctionSig* sig, const Val args[],
               i::wasm::CWasmArgumentsPacker* packer, StoreImpl* store) {
   for (size_t i = 0; i < sig->parameter_count(); i++) {
     i::wasm::ValueType type = sig->GetParam(i);
-    switch (type) {
-      case i::wasm::kWasmI32:
+    switch (type.kind()) {
+      case i::wasm::ValueType::kI32:
         packer->Push(args[i].i32());
         break;
-      case i::wasm::kWasmI64:
+      case i::wasm::ValueType::kI64:
         packer->Push(args[i].i64());
         break;
-      case i::wasm::kWasmF32:
+      case i::wasm::ValueType::kF32:
         packer->Push(args[i].f32());
         break;
-      case i::wasm::kWasmF64:
+      case i::wasm::ValueType::kF64:
         packer->Push(args[i].f64());
         break;
-      case i::wasm::kWasmAnyRef:
-      case i::wasm::kWasmFuncRef:
-      case i::wasm::kWasmNullRef:
+      case i::wasm::ValueType::kAnyRef:
+      case i::wasm::ValueType::kFuncRef:
+      case i::wasm::ValueType::kNullRef:
         packer->Push(WasmRefToV8(store->i_isolate(), args[i].ref())->ptr());
         break;
-      case i::wasm::kWasmExnRef:
+      case i::wasm::ValueType::kExnRef:
         // TODO(jkummerow): Implement these.
         UNIMPLEMENTED();
         break;
@@ -1425,34 +1429,34 @@ void PushArgs(i::wasm::FunctionSig* sig, const Val args[],
   }
 }
 
-void PopArgs(i::wasm::FunctionSig* sig, Val results[],
+void PopArgs(const i::wasm::FunctionSig* sig, Val results[],
              i::wasm::CWasmArgumentsPacker* packer, StoreImpl* store) {
   packer->Reset();
   for (size_t i = 0; i < sig->return_count(); i++) {
     i::wasm::ValueType type = sig->GetReturn(i);
-    switch (type) {
-      case i::wasm::kWasmI32:
+    switch (type.kind()) {
+      case i::wasm::ValueType::kI32:
         results[i] = Val(packer->Pop<int32_t>());
         break;
-      case i::wasm::kWasmI64:
+      case i::wasm::ValueType::kI64:
         results[i] = Val(packer->Pop<int64_t>());
         break;
-      case i::wasm::kWasmF32:
+      case i::wasm::ValueType::kF32:
         results[i] = Val(packer->Pop<float>());
         break;
-      case i::wasm::kWasmF64:
+      case i::wasm::ValueType::kF64:
         results[i] = Val(packer->Pop<double>());
         break;
-      case i::wasm::kWasmAnyRef:
-      case i::wasm::kWasmFuncRef:
-      case i::wasm::kWasmNullRef: {
+      case i::wasm::ValueType::kAnyRef:
+      case i::wasm::ValueType::kFuncRef:
+      case i::wasm::ValueType::kNullRef: {
         i::Address raw = packer->Pop<i::Address>();
         i::Handle<i::Object> obj(i::Object(raw), store->i_isolate());
         DCHECK_IMPLIES(type == i::wasm::kWasmNullRef, obj->IsNull());
         results[i] = Val(V8RefValueToWasm(store, obj));
         break;
       }
-      case i::wasm::kWasmExnRef:
+      case i::wasm::ValueType::kExnRef:
         // TODO(jkummerow): Implement these.
         UNIMPLEMENTED();
         break;
@@ -1512,7 +1516,8 @@ auto Func::call(const Val args[], Val results[]) const -> own<Trap> {
   i::Handle<i::WasmInstanceObject> instance(function_data->instance(), isolate);
   int function_index = function_data->function_index();
   // Caching {sig} would give a ~10% reduction in overhead.
-  i::wasm::FunctionSig* sig = instance->module()->functions[function_index].sig;
+  const i::wasm::FunctionSig* sig =
+      instance->module()->functions[function_index].sig;
   PrepareFunctionData(isolate, function_data, sig);
   i::Handle<i::Code> wrapper_code = i::Handle<i::Code>(
       i::Code::cast(function_data->c_wrapper_code()), isolate);
@@ -1693,17 +1698,17 @@ auto Global::type() const -> own<GlobalType> {
 
 auto Global::get() const -> Val {
   i::Handle<i::WasmGlobalObject> v8_global = impl(this)->v8_object();
-  switch (v8_global->type()) {
-    case i::wasm::kWasmI32:
+  switch (v8_global->type().kind()) {
+    case i::wasm::ValueType::kI32:
       return Val(v8_global->GetI32());
-    case i::wasm::kWasmI64:
+    case i::wasm::ValueType::kI64:
       return Val(v8_global->GetI64());
-    case i::wasm::kWasmF32:
+    case i::wasm::ValueType::kF32:
       return Val(v8_global->GetF32());
-    case i::wasm::kWasmF64:
+    case i::wasm::ValueType::kF64:
       return Val(v8_global->GetF64());
-    case i::wasm::kWasmAnyRef:
-    case i::wasm::kWasmFuncRef: {
+    case i::wasm::ValueType::kAnyRef:
+    case i::wasm::ValueType::kFuncRef: {
       StoreImpl* store = impl(this)->store();
       i::HandleScope scope(store->i_isolate());
       return Val(V8RefValueToWasm(store, v8_global->GetRef()));
@@ -1810,11 +1815,11 @@ auto Table::type() const -> own<TableType> {
   uint32_t max;
   if (!table->maximum_length().ToUint32(&max)) max = 0xFFFFFFFFu;
   ValKind kind;
-  switch (table->type()) {
-    case i::wasm::kWasmFuncRef:
+  switch (table->type().kind()) {
+    case i::wasm::ValueType::kFuncRef:
       kind = FUNCREF;
       break;
-    case i::wasm::kWasmAnyRef:
+    case i::wasm::ValueType::kAnyRef:
       kind = ANYREF;
       break;
     default:
@@ -1879,11 +1884,13 @@ auto Memory::make(Store* store_abs, const MemoryType* type) -> own<Memory> {
 
   const Limits& limits = type->limits();
   uint32_t minimum = limits.min;
-  if (minimum > i::wasm::max_mem_pages()) return nullptr;
+  // The max_initial_mem_pages limit is only spec'ed for JS embeddings,
+  // so we'll directly use the maximum pages limit here.
+  if (minimum > i::wasm::kSpecMaxWasmMaximumMemoryPages) return nullptr;
   uint32_t maximum = limits.max;
   if (maximum != Limits(0).max) {
     if (maximum < minimum) return nullptr;
-    if (maximum > i::wasm::kSpecMaxWasmMemoryPages) return nullptr;
+    if (maximum > i::wasm::kSpecMaxWasmMaximumMemoryPages) return nullptr;
   }
   // TODO(wasm+): Support shared memory.
   i::SharedFlag shared = i::SharedFlag::kNotShared;
diff --git a/deps/v8/src/wasm/compilation-environment.h b/deps/v8/src/wasm/compilation-environment.h
index 629ebe913e..be60dfd519 100644
--- a/deps/v8/src/wasm/compilation-environment.h
+++ b/deps/v8/src/wasm/compilation-environment.h
@@ -60,11 +60,15 @@ struct CompilationEnv {
 
   const LowerSimd lower_simd;
 
+  // Whether the debugger is active.
+  const bool debug;
+
   constexpr CompilationEnv(const WasmModule* module,
                            UseTrapHandler use_trap_handler,
                            RuntimeExceptionSupport runtime_exception_support,
                            const WasmFeatures& enabled_features,
-                           LowerSimd lower_simd = kNoLowerSimd)
+                           LowerSimd lower_simd = kNoLowerSimd,
+                           bool debug = false)
       : module(module),
         use_trap_handler(use_trap_handler),
         runtime_exception_support(runtime_exception_support),
@@ -72,10 +76,11 @@ struct CompilationEnv {
                                : 0),
         max_memory_size((module && module->has_maximum_pages
                              ? module->maximum_pages
-                             : max_mem_pages()) *
+                             : max_initial_mem_pages()) *
                         uint64_t{kWasmPageSize}),
         enabled_features(enabled_features),
-        lower_simd(lower_simd) {}
+        lower_simd(lower_simd),
+        debug(debug) {}
 };
 
 // The wire bytes are either owned by the StreamingDecoder, or (after streaming)
diff --git a/deps/v8/src/wasm/decoder.h b/deps/v8/src/wasm/decoder.h
index f6c88d0416..3c0c0493b0 100644
--- a/deps/v8/src/wasm/decoder.h
+++ b/deps/v8/src/wasm/decoder.h
@@ -266,6 +266,7 @@ class Decoder {
     return offset - buffer_offset_;
   }
   const byte* end() const { return end_; }
+  void set_end(const byte* end) { end_ = end; }
 
   // Check if the byte at {offset} from the current pc equals {expected}.
   bool lookahead(int offset, byte expected) {
diff --git a/deps/v8/src/wasm/function-body-decoder-impl.h b/deps/v8/src/wasm/function-body-decoder-impl.h
index 496598b18f..9752d4ef0c 100644
--- a/deps/v8/src/wasm/function-body-decoder-impl.h
+++ b/deps/v8/src/wasm/function-body-decoder-impl.h
@@ -277,7 +277,7 @@ struct BlockTypeImmediate {
   uint32_t length = 1;
   ValueType type = kWasmStmt;
   uint32_t sig_index = 0;
-  FunctionSig* sig = nullptr;
+  const FunctionSig* sig = nullptr;
 
   inline BlockTypeImmediate(const WasmFeatures& enabled, Decoder* decoder,
                             const byte* pc) {
@@ -377,7 +377,7 @@ template <Decoder::ValidateFlag validate>
 struct CallIndirectImmediate {
   uint32_t table_index;
   uint32_t sig_index;
-  FunctionSig* sig = nullptr;
+  const FunctionSig* sig = nullptr;
   uint32_t length = 0;
   inline CallIndirectImmediate(const WasmFeatures enabled, Decoder* decoder,
                                const byte* pc) {
@@ -397,7 +397,7 @@ struct CallIndirectImmediate {
 template <Decoder::ValidateFlag validate>
 struct CallFunctionImmediate {
   uint32_t index;
-  FunctionSig* sig = nullptr;
+  const FunctionSig* sig = nullptr;
   uint32_t length;
   inline CallFunctionImmediate(Decoder* decoder, const byte* pc) {
     index = decoder->read_u32v<validate>(pc + 1, &length, "function index");
@@ -782,7 +782,7 @@ template <Decoder::ValidateFlag validate>
 class WasmDecoder : public Decoder {
  public:
   WasmDecoder(const WasmModule* module, const WasmFeatures& enabled,
-              WasmFeatures* detected, FunctionSig* sig, const byte* start,
+              WasmFeatures* detected, const FunctionSig* sig, const byte* start,
               const byte* end, uint32_t buffer_offset = 0)
       : Decoder(start, end, buffer_offset),
         module_(module),
@@ -793,7 +793,7 @@ class WasmDecoder : public Decoder {
   const WasmModule* module_;
   const WasmFeatures enabled_;
   WasmFeatures* detected_;
-  FunctionSig* sig_;
+  const FunctionSig* sig_;
 
   ZoneVector<ValueType>* local_types_;
 
@@ -989,7 +989,7 @@ class WasmDecoder : public Decoder {
     return true;
   }
 
-  inline bool CanReturnCall(FunctionSig* target_sig) {
+  inline bool CanReturnCall(const FunctionSig* target_sig) {
     if (target_sig == nullptr) return false;
     size_t num_returns = sig_->return_count();
     if (num_returns != target_sig->return_count()) return false;
@@ -1133,11 +1133,15 @@ class WasmDecoder : public Decoder {
   }
 
   inline bool Validate(const byte* pc, FunctionIndexImmediate<validate>& imm) {
-    if (!VALIDATE(module_ != nullptr &&
-                  imm.index < module_->functions.size())) {
+    if (!module_) return true;
+    if (!VALIDATE(imm.index < module_->functions.size())) {
       errorf(pc, "invalid function index: %u", imm.index);
       return false;
     }
+    if (!VALIDATE(module_->functions[imm.index].declared)) {
+      this->errorf(pc, "undeclared reference to function #%u", imm.index);
+      return false;
+    }
     return true;
   }
 
@@ -1191,8 +1195,16 @@ class WasmDecoder : public Decoder {
              imm.elem_segment_index);
       return false;
     }
-    if (!Validate(pc_ + imm.length - imm.table.length - 1, imm.table))
+    if (!Validate(pc_ + imm.length - imm.table.length - 1, imm.table)) {
+      return false;
+    }
+    ValueType elem_type = module_->elem_segments[imm.elem_segment_index].type;
+    if (!VALIDATE(
+            elem_type.IsSubTypeOf(module_->tables[imm.table.index].type))) {
+      errorf(pc_ + 2, "table %u is not a super-type of %s", imm.table.index,
+             elem_type.type_name());
       return false;
+    }
     return true;
   }
 
@@ -1208,6 +1220,13 @@ class WasmDecoder : public Decoder {
   inline bool Validate(TableCopyImmediate<validate>& imm) {
     if (!Validate(pc_ + 1, imm.table_src)) return false;
     if (!Validate(pc_ + 2, imm.table_dst)) return false;
+    ValueType src_type = module_->tables[imm.table_src.index].type;
+    if (!VALIDATE(
+            src_type.IsSubTypeOf(module_->tables[imm.table_dst.index].type))) {
+      errorf(pc_ + 2, "table %u is not a super-type of %s", imm.table_dst.index,
+             src_type.type_name());
+      return false;
+    }
     return true;
   }
 
@@ -1418,7 +1437,7 @@ class WasmDecoder : public Decoder {
   std::pair<uint32_t, uint32_t> StackEffect(const byte* pc) {
     WasmOpcode opcode = static_cast<WasmOpcode>(*pc);
     // Handle "simple" opcodes with a fixed signature first.
-    FunctionSig* sig = WasmOpcodes::Signature(opcode);
+    const FunctionSig* sig = WasmOpcodes::Signature(opcode);
     if (!sig) sig = WasmOpcodes::AsmjsSignature(opcode);
     if (sig) return {sig->parameter_count(), sig->return_count()};
 
@@ -1927,7 +1946,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           auto fval = Pop();
           auto tval = Pop(0, fval.type);
           ValueType type = tval.type == kWasmBottom ? fval.type : tval.type;
-          if (ValueTypes::IsSubType(type, kWasmAnyRef)) {
+          if (type.IsSubTypeOf(kWasmAnyRef)) {
             this->error(
                 "select without type is only valid for value type inputs");
             break;
@@ -2367,7 +2386,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
         default: {
           // Deal with special asmjs opcodes.
           if (this->module_ != nullptr && is_asmjs_module(this->module_)) {
-            FunctionSig* sig = WasmOpcodes::AsmjsSignature(opcode);
+            const FunctionSig* sig = WasmOpcodes::AsmjsSignature(opcode);
             if (sig) {
               BuildSimpleOperator(opcode, sig);
             }
@@ -2409,7 +2428,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           if (WasmOpcodes::IsPrefixOpcode(opcode)) {
             opcode = static_cast<WasmOpcode>(opcode << 8 | *(val.pc + 1));
           }
-          TRACE_PART(" %c@%d:%s", ValueTypes::ShortNameOf(val.type),
+          TRACE_PART(" %c@%d:%s", val.type.short_name(),
                      static_cast<int>(val.pc - this->start_),
                      WasmOpcodes::OpcodeName(opcode));
           // If the decoder failed, don't try to decode the immediates, as this
@@ -2479,7 +2498,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   }
 
   // Pops arguments as required by signature.
-  V8_INLINE ArgVector PopArgs(FunctionSig* sig) {
+  V8_INLINE ArgVector PopArgs(const FunctionSig* sig) {
     int count = sig ? static_cast<int>(sig->parameter_count()) : 0;
     ArgVector args(count);
     for (int i = count - 1; i >= 0; --i) {
@@ -2488,7 +2507,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return args;
   }
 
-  ValueType GetReturnType(FunctionSig* sig) {
+  ValueType GetReturnType(const FunctionSig* sig) {
     DCHECK_GE(1, sig->return_count());
     return sig->return_count() == 0 ? kWasmStmt : sig->GetReturn();
   }
@@ -2531,7 +2550,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     if (!CheckHasMemory()) return 0;
     MemoryAccessImmediate<validate> imm(this, this->pc_ + 1, type.size_log_2());
     auto index = Pop(0, kWasmI32);
-    auto* result = Push(ValueType::kWasmS128);
+    auto* result = Push(kWasmS128);
     CALL_INTERFACE_IF_REACHABLE(LoadTransform, type, transform, imm, index,
                                 result);
     return imm.length;
@@ -2583,15 +2602,15 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       if (this->enabled_.has_anyref()) {
         // The expected type is the biggest common sub type of all targets.
         (*result_types)[i] =
-            ValueTypes::CommonSubType((*result_types)[i], (*merge)[i].type);
+            ValueType::CommonSubType((*result_types)[i], (*merge)[i].type);
       } else {
         // All target must have the same signature.
         if ((*result_types)[i] != (*merge)[i].type) {
           this->errorf(pos,
                        "inconsistent type in br_table target %u (previous "
                        "was %s, this one is %s)",
-                       index, ValueTypes::TypeName((*result_types)[i]),
-                       ValueTypes::TypeName((*merge)[i].type));
+                       index, (*result_types)[i].type_name(),
+                       (*merge)[i].type.type_name());
           return false;
         }
       }
@@ -2601,7 +2620,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
 
   bool TypeCheckBrTable(const std::vector<ValueType>& result_types) {
     int br_arity = static_cast<int>(result_types.size());
-    if (V8_LIKELY(control_.back().reachable())) {
+    if (V8_LIKELY(!control_.back().unreachable())) {
       int available =
           static_cast<int>(stack_.size()) - control_.back().stack_depth;
       // There have to be enough values on the stack.
@@ -2616,11 +2635,10 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       // Type-check the topmost br_arity values on the stack.
       for (int i = 0; i < br_arity; ++i) {
         Value& val = stack_values[i];
-        if (!ValueTypes::IsSubType(val.type, result_types[i])) {
+        if (!val.type.IsSubTypeOf(result_types[i])) {
           this->errorf(this->pc_,
                        "type error in merge[%u] (expected %s, got %s)", i,
-                       ValueTypes::TypeName(result_types[i]),
-                       ValueTypes::TypeName(val.type));
+                       result_types[i].type_name(), val.type.type_name());
           return false;
         }
       }
@@ -2760,7 +2778,13 @@ class WasmFullDecoder : public WasmDecoder<validate> {
                                      LoadTransformationKind::kExtend);
         break;
       default: {
-        FunctionSig* sig = WasmOpcodes::Signature(opcode);
+        if (!FLAG_wasm_simd_post_mvp &&
+            WasmOpcodes::IsSimdPostMvpOpcode(opcode)) {
+          this->error(
+              "simd opcode not available, enable with --wasm-simd-post-mvp");
+          break;
+        }
+        const FunctionSig* sig = WasmOpcodes::Signature(opcode);
         if (!VALIDATE(sig != nullptr)) {
           this->error("invalid simd opcode");
           break;
@@ -2777,7 +2801,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
   uint32_t DecodeAtomicOpcode(WasmOpcode opcode) {
     uint32_t len = 0;
     ValueType ret_type;
-    FunctionSig* sig = WasmOpcodes::Signature(opcode);
+    const FunctionSig* sig = WasmOpcodes::Signature(opcode);
     if (!VALIDATE(sig != nullptr)) {
       this->error("invalid atomic opcode");
       return 0;
@@ -2825,7 +2849,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
 
   unsigned DecodeNumericOpcode(WasmOpcode opcode) {
     unsigned len = 0;
-    FunctionSig* sig = WasmOpcodes::Signature(opcode);
+    const FunctionSig* sig = WasmOpcodes::Signature(opcode);
     if (sig != nullptr) {
       switch (opcode) {
         case kExprI32SConvertSatF32:
@@ -2967,7 +2991,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     DCHECK_EQ(c->stack_depth + merge->arity, stack_.size());
   }
 
-  Value* PushReturns(FunctionSig* sig) {
+  Value* PushReturns(const FunctionSig* sig) {
     size_t return_count = sig->return_count();
     if (return_count == 0) return nullptr;
     size_t old_size = stack_.size();
@@ -2979,12 +3003,11 @@ class WasmFullDecoder : public WasmDecoder<validate> {
 
   V8_INLINE Value Pop(int index, ValueType expected) {
     auto val = Pop();
-    if (!VALIDATE(ValueTypes::IsSubType(val.type, expected) ||
-                  val.type == kWasmBottom || expected == kWasmBottom)) {
+    if (!VALIDATE(val.type.IsSubTypeOf(expected) || val.type == kWasmBottom ||
+                  expected == kWasmBottom)) {
       this->errorf(val.pc, "%s[%d] expected type %s, found %s of type %s",
-                   SafeOpcodeNameAt(this->pc_), index,
-                   ValueTypes::TypeName(expected), SafeOpcodeNameAt(val.pc),
-                   ValueTypes::TypeName(val.type));
+                   SafeOpcodeNameAt(this->pc_), index, expected.type_name(),
+                   SafeOpcodeNameAt(val.pc), val.type.type_name());
     }
     return val;
   }
@@ -3044,10 +3067,9 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     for (uint32_t i = 0; i < merge->arity; ++i) {
       Value& val = stack_values[i];
       Value& old = (*merge)[i];
-      if (!ValueTypes::IsSubType(val.type, old.type)) {
+      if (!val.type.IsSubTypeOf(old.type)) {
         this->errorf(this->pc_, "type error in merge[%u] (expected %s, got %s)",
-                     i, ValueTypes::TypeName(old.type),
-                     ValueTypes::TypeName(val.type));
+                     i, old.type.type_name(), val.type.type_name());
         return false;
       }
     }
@@ -3062,10 +3084,9 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     for (uint32_t i = 0; i < c->start_merge.arity; ++i) {
       Value& start = c->start_merge[i];
       Value& end = c->end_merge[i];
-      if (!ValueTypes::IsSubType(start.type, end.type)) {
+      if (!start.type.IsSubTypeOf(end.type)) {
         this->errorf(this->pc_, "type error in merge[%u] (expected %s, got %s)",
-                     i, ValueTypes::TypeName(end.type),
-                     ValueTypes::TypeName(start.type));
+                     i, end.type.type_name(), start.type.type_name());
         return false;
       }
     }
@@ -3167,11 +3188,10 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     for (int i = 0; i < num_returns; ++i) {
       auto& val = stack_values[i];
       ValueType expected_type = this->sig_->GetReturn(i);
-      if (!ValueTypes::IsSubType(val.type, expected_type)) {
+      if (!val.type.IsSubTypeOf(expected_type)) {
         this->errorf(this->pc_,
                      "type error in return[%u] (expected %s, got %s)", i,
-                     ValueTypes::TypeName(expected_type),
-                     ValueTypes::TypeName(val.type));
+                     expected_type.type_name(), val.type.type_name());
         return false;
       }
     }
@@ -3188,11 +3208,11 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     if (WasmOpcodes::IsAnyRefOpcode(opcode)) {
       RET_ON_PROTOTYPE_OPCODE(anyref);
     }
-    FunctionSig* sig = WasmOpcodes::Signature(opcode);
+    const FunctionSig* sig = WasmOpcodes::Signature(opcode);
     BuildSimpleOperator(opcode, sig);
   }
 
-  void BuildSimpleOperator(WasmOpcode opcode, FunctionSig* sig) {
+  void BuildSimpleOperator(WasmOpcode opcode, const FunctionSig* sig) {
     switch (sig->parameter_count()) {
       case 1: {
         auto val = Pop(0, sig->GetParam(0));
diff --git a/deps/v8/src/wasm/function-body-decoder.cc b/deps/v8/src/wasm/function-body-decoder.cc
index 3113d1665b..63788bcc8d 100644
--- a/deps/v8/src/wasm/function-body-decoder.cc
+++ b/deps/v8/src/wasm/function-body-decoder.cc
@@ -59,8 +59,8 @@ unsigned OpcodeLength(const byte* pc, const byte* end) {
 }
 
 std::pair<uint32_t, uint32_t> StackEffect(const WasmModule* module,
-                                          FunctionSig* sig, const byte* pc,
-                                          const byte* end) {
+                                          const FunctionSig* sig,
+                                          const byte* pc, const byte* end) {
   WasmFeatures unused_detected_features = WasmFeatures::None();
   WasmDecoder<Decoder::kNoValidate> decoder(
       module, WasmFeatures::All(), &unused_detected_features, sig, pc, end);
@@ -135,12 +135,12 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
         if (decls.type_list[pos] == type) {
           ++count;
         } else {
-          os << " " << count << " " << ValueTypes::TypeName(type);
+          os << " " << count << " " << type.type_name();
           type = decls.type_list[pos];
           count = 1;
         }
       }
-      os << " " << count << " " << ValueTypes::TypeName(type);
+      os << " " << count << " " << type.type_name();
     }
     os << std::endl;
     if (line_numbers) line_numbers->push_back(kNoByteCode);
@@ -210,10 +210,12 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
       }
     }
 
+    os << "  // " << WasmOpcodes::OpcodeName(opcode);
+
     switch (opcode) {
       case kExprElse:
       case kExprCatch:
-        os << "   // @" << i.pc_offset();
+        os << " @" << i.pc_offset();
         control_depth++;
         break;
       case kExprLoop:
@@ -222,38 +224,38 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
       case kExprTry: {
         BlockTypeImmediate<Decoder::kNoValidate> imm(WasmFeatures::All(), &i,
                                                      i.pc());
-        os << "   // @" << i.pc_offset();
+        os << " @" << i.pc_offset();
         if (decoder.Complete(imm)) {
           for (uint32_t i = 0; i < imm.out_arity(); i++) {
-            os << " " << ValueTypes::TypeName(imm.out_type(i));
+            os << " " << imm.out_type(i).type_name();
           }
         }
         control_depth++;
         break;
       }
       case kExprEnd:
-        os << "   // @" << i.pc_offset();
+        os << " @" << i.pc_offset();
         control_depth--;
         break;
       case kExprBr: {
         BranchDepthImmediate<Decoder::kNoValidate> imm(&i, i.pc());
-        os << "   // depth=" << imm.depth;
+        os << " depth=" << imm.depth;
         break;
       }
       case kExprBrIf: {
         BranchDepthImmediate<Decoder::kNoValidate> imm(&i, i.pc());
-        os << "   // depth=" << imm.depth;
+        os << " depth=" << imm.depth;
         break;
       }
       case kExprBrTable: {
         BranchTableImmediate<Decoder::kNoValidate> imm(&i, i.pc());
-        os << " // entries=" << imm.table_count;
+        os << " entries=" << imm.table_count;
         break;
       }
       case kExprCallIndirect: {
         CallIndirectImmediate<Decoder::kNoValidate> imm(WasmFeatures::All(), &i,
                                                         i.pc());
-        os << "   // sig #" << imm.sig_index;
+        os << " sig #" << imm.sig_index;
         if (decoder.Complete(i.pc(), imm)) {
           os << ": " << *imm.sig;
         }
@@ -261,7 +263,7 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
       }
       case kExprCallFunction: {
         CallFunctionImmediate<Decoder::kNoValidate> imm(&i, i.pc());
-        os << " // function #" << imm.index;
+        os << " function #" << imm.index;
         if (decoder.Complete(i.pc(), imm)) {
           os << ": " << *imm.sig;
         }
diff --git a/deps/v8/src/wasm/function-body-decoder.h b/deps/v8/src/wasm/function-body-decoder.h
index ef91d8a0e9..f542540233 100644
--- a/deps/v8/src/wasm/function-body-decoder.h
+++ b/deps/v8/src/wasm/function-body-decoder.h
@@ -24,12 +24,12 @@ struct WasmModule;  // forward declaration of module interface.
 
 // A wrapper around the signature and bytes of a function.
 struct FunctionBody {
-  FunctionSig* sig;   // function signature
-  uint32_t offset;    // offset in the module bytes, for error reporting
-  const byte* start;  // start of the function body
-  const byte* end;    // end of the function body
+  const FunctionSig* sig;  // function signature
+  uint32_t offset;         // offset in the module bytes, for error reporting
+  const byte* start;       // start of the function body
+  const byte* end;         // end of the function body
 
-  FunctionBody(FunctionSig* sig, uint32_t offset, const byte* start,
+  FunctionBody(const FunctionSig* sig, uint32_t offset, const byte* start,
                const byte* end)
       : sig(sig), offset(offset), start(start), end(end) {}
 };
@@ -81,8 +81,8 @@ V8_EXPORT_PRIVATE unsigned OpcodeLength(const byte* pc, const byte* end);
 // local stack effect (e.g. BrIf pops 1, Br pops 0). Those opcodes can have
 // non-local stack effect though, which are not covered here.
 std::pair<uint32_t, uint32_t> StackEffect(const WasmModule* module,
-                                          FunctionSig* sig, const byte* pc,
-                                          const byte* end);
+                                          const FunctionSig* sig,
+                                          const byte* pc, const byte* end);
 
 // A simple forward iterator for bytecodes.
 class V8_EXPORT_PRIVATE BytecodeIterator : public NON_EXPORTED_BASE(Decoder) {
diff --git a/deps/v8/src/wasm/function-compiler.cc b/deps/v8/src/wasm/function-compiler.cc
index f285deca1c..1b6b83a3b1 100644
--- a/deps/v8/src/wasm/function-compiler.cc
+++ b/deps/v8/src/wasm/function-compiler.cc
@@ -145,7 +145,7 @@ WasmCompilationResult WasmCompilationUnit::ExecuteCompilation(
 
 WasmCompilationResult WasmCompilationUnit::ExecuteImportWrapperCompilation(
     WasmEngine* engine, CompilationEnv* env) {
-  FunctionSig* sig = env->module->functions[func_index_].sig;
+  const FunctionSig* sig = env->module->functions[func_index_].sig;
   // Assume the wrapper is going to be a JS function with matching arity at
   // instantiation time.
   auto kind = compiler::kDefaultImportCallKind;
@@ -265,8 +265,8 @@ void WasmCompilationUnit::CompileWasmFunction(Isolate* isolate,
 }
 
 JSToWasmWrapperCompilationUnit::JSToWasmWrapperCompilationUnit(
-    Isolate* isolate, WasmEngine* wasm_engine, FunctionSig* sig, bool is_import,
-    const WasmFeatures& enabled_features)
+    Isolate* isolate, WasmEngine* wasm_engine, const FunctionSig* sig,
+    bool is_import, const WasmFeatures& enabled_features)
     : is_import_(is_import),
       sig_(sig),
       job_(compiler::NewJSToWasmCompilationJob(isolate, wasm_engine, sig,
@@ -293,7 +293,7 @@ Handle<Code> JSToWasmWrapperCompilationUnit::Finalize(Isolate* isolate) {
 
 // static
 Handle<Code> JSToWasmWrapperCompilationUnit::CompileJSToWasmWrapper(
-    Isolate* isolate, FunctionSig* sig, bool is_import) {
+    Isolate* isolate, const FunctionSig* sig, bool is_import) {
   // Run the compilation unit synchronously.
   WasmFeatures enabled_features = WasmFeatures::FromIsolate(isolate);
   JSToWasmWrapperCompilationUnit unit(isolate, isolate->wasm_engine(), sig,
diff --git a/deps/v8/src/wasm/function-compiler.h b/deps/v8/src/wasm/function-compiler.h
index 9d6d40e140..a511f19b76 100644
--- a/deps/v8/src/wasm/function-compiler.h
+++ b/deps/v8/src/wasm/function-compiler.h
@@ -67,8 +67,8 @@ struct WasmCompilationResult {
   uint32_t frame_slot_count = 0;
   uint32_t tagged_parameter_slots = 0;
   OwnedVector<byte> source_positions;
-  OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions;
-  int func_index = static_cast<int>(kAnonymousFuncIndex);
+  OwnedVector<byte> protected_instructions_data;
+  int func_index = kAnonymousFuncIndex;
   ExecutionTier requested_tier;
   ExecutionTier result_tier;
   Kind kind = kFunction;
@@ -113,7 +113,7 @@ STATIC_ASSERT(sizeof(WasmCompilationUnit) <= 2 * kSystemPointerSize);
 class V8_EXPORT_PRIVATE JSToWasmWrapperCompilationUnit final {
  public:
   JSToWasmWrapperCompilationUnit(Isolate* isolate, WasmEngine* wasm_engine,
-                                 FunctionSig* sig, bool is_import,
+                                 const FunctionSig* sig, bool is_import,
                                  const WasmFeatures& enabled_features);
   ~JSToWasmWrapperCompilationUnit();
 
@@ -121,15 +121,16 @@ class V8_EXPORT_PRIVATE JSToWasmWrapperCompilationUnit final {
   Handle<Code> Finalize(Isolate* isolate);
 
   bool is_import() const { return is_import_; }
-  FunctionSig* sig() const { return sig_; }
+  const FunctionSig* sig() const { return sig_; }
 
   // Run a compilation unit synchronously.
-  static Handle<Code> CompileJSToWasmWrapper(Isolate* isolate, FunctionSig* sig,
+  static Handle<Code> CompileJSToWasmWrapper(Isolate* isolate,
+                                             const FunctionSig* sig,
                                              bool is_import);
 
  private:
   bool is_import_;
-  FunctionSig* sig_;
+  const FunctionSig* sig_;
   std::unique_ptr<OptimizedCompilationJob> job_;
 };
 
diff --git a/deps/v8/src/wasm/graph-builder-interface.cc b/deps/v8/src/wasm/graph-builder-interface.cc
index e2ddafbf30..5f73f27200 100644
--- a/deps/v8/src/wasm/graph-builder-interface.cc
+++ b/deps/v8/src/wasm/graph-builder-interface.cc
@@ -397,8 +397,9 @@ class WasmGraphBuildingInterface {
                      LoadTransformationKind transform,
                      const MemoryAccessImmediate<validate>& imm,
                      const Value& index, Value* result) {
-    result->node = BUILD(LoadTransform, type.mem_type(), transform, index.node,
-                         imm.offset, imm.alignment, decoder->position());
+    result->node =
+        BUILD(LoadTransform, type.value_type(), type.mem_type(), transform,
+              index.node, imm.offset, imm.alignment, decoder->position());
   }
 
   void StoreMem(FullDecoder* decoder, StoreType type,
@@ -491,7 +492,8 @@ class WasmGraphBuildingInterface {
     TFNode* if_no_match = nullptr;
 
     // Get the exception tag and see if it matches the expected one.
-    TFNode* caught_tag = BUILD(GetExceptionTag, exception.node);
+    TFNode* caught_tag =
+        BUILD(GetExceptionTag, exception.node, decoder->position());
     TFNode* exception_tag = BUILD(LoadExceptionTagFromTable, imm.index);
     TFNode* compare = BUILD(ExceptionTagEqual, caught_tag, exception_tag);
     BUILD(BranchNoHint, compare, &if_match, &if_no_match);
@@ -694,21 +696,21 @@ class WasmGraphBuildingInterface {
   }
 
   TFNode* DefaultValue(ValueType type) {
-    switch (type) {
-      case kWasmI32:
+    switch (type.kind()) {
+      case ValueType::kI32:
         return builder_->Int32Constant(0);
-      case kWasmI64:
+      case ValueType::kI64:
         return builder_->Int64Constant(0);
-      case kWasmF32:
+      case ValueType::kF32:
         return builder_->Float32Constant(0);
-      case kWasmF64:
+      case ValueType::kF64:
         return builder_->Float64Constant(0);
-      case kWasmS128:
+      case ValueType::kS128:
         return builder_->S128Zero();
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
+      case ValueType::kAnyRef:
+      case ValueType::kFuncRef:
+      case ValueType::kNullRef:
+      case ValueType::kExnRef:
         return builder_->RefNull();
       default:
         UNREACHABLE();
@@ -729,13 +731,12 @@ class WasmGraphBuildingInterface {
       Value& val = values[i];
       Value& old = (*merge)[i];
       DCHECK_NOT_NULL(val.node);
-      DCHECK(val.type == kWasmBottom ||
-             ValueTypes::MachineRepresentationFor(val.type) ==
-                 ValueTypes::MachineRepresentationFor(old.type));
+      DCHECK(val.type == kWasmBottom || val.type.machine_representation() ==
+                                            old.type.machine_representation());
       old.node = first ? val.node
                        : builder_->CreateOrMergeIntoPhi(
-                             ValueTypes::MachineRepresentationFor(old.type),
-                             target->control, old.node, val.node);
+                             old.type.machine_representation(), target->control,
+                             old.node, val.node);
     }
   }
 
@@ -797,8 +798,8 @@ class WasmGraphBuildingInterface {
         // Merge locals.
         for (int i = decoder->num_locals() - 1; i >= 0; i--) {
           to->locals[i] = builder_->CreateOrMergeIntoPhi(
-              ValueTypes::MachineRepresentationFor(decoder->GetLocalType(i)),
-              merge, to->locals[i], ssa_env_->locals[i]);
+              decoder->GetLocalType(i).machine_representation(), merge,
+              to->locals[i], ssa_env_->locals[i]);
         }
         // Merge the instance caches.
         builder_->MergeInstanceCacheInto(&to->instance_cache,
@@ -910,7 +911,7 @@ class WasmGraphBuildingInterface {
   }
 
   void DoCall(FullDecoder* decoder, uint32_t table_index, TFNode* index_node,
-              FunctionSig* sig, uint32_t sig_index, const Value args[],
+              const FunctionSig* sig, uint32_t sig_index, const Value args[],
               Value returns[]) {
     size_t param_count = sig->parameter_count();
     size_t return_count = sig->return_count();
@@ -936,8 +937,8 @@ class WasmGraphBuildingInterface {
   }
 
   void DoReturnCall(FullDecoder* decoder, uint32_t table_index,
-                    TFNode* index_node, FunctionSig* sig, uint32_t sig_index,
-                    const Value args[]) {
+                    TFNode* index_node, const FunctionSig* sig,
+                    uint32_t sig_index, const Value args[]) {
     size_t arg_count = sig->parameter_count();
     base::SmallVector<TFNode*, 16> arg_nodes(arg_count + 1);
     arg_nodes[0] = index_node;
diff --git a/deps/v8/src/wasm/jump-table-assembler.cc b/deps/v8/src/wasm/jump-table-assembler.cc
index ad73562d26..90cdad4672 100644
--- a/deps/v8/src/wasm/jump-table-assembler.cc
+++ b/deps/v8/src/wasm/jump-table-assembler.cc
@@ -134,6 +134,7 @@ void JumpTableAssembler::NopBytes(int bytes) {
 void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
                                                  Address lazy_compile_target) {
   int start = pc_offset();
+  CodeEntry();                                             // 0-1 instr
   Mov(kWasmCompileLazyFuncIndexRegister.W(), func_index);  // 1-2 instr
   Jump(lazy_compile_target, RelocInfo::NONE);              // 1 instr
   int nop_bytes = start + kLazyCompileTableSlotSize - pc_offset();
@@ -147,6 +148,8 @@ bool JumpTableAssembler::EmitJumpSlot(Address target) {
     return false;
   }
 
+  CodeEntry();
+
   Jump(target, RelocInfo::NONE);
   return true;
 }
@@ -157,22 +160,31 @@ void JumpTableAssembler::EmitFarJumpSlot(Address target) {
   // will only be called for the very specific runtime slot table, and we want
   // to have maximum control over the generated code.
   // Do not reuse this code without validating that the same assumptions hold.
+  CodeEntry();  // 0-1 instructions
   constexpr Register kTmpReg = x16;
   DCHECK(TmpList()->IncludesAliasOf(kTmpReg));
-  // Load from [pc + 2 * kInstrSize] to {kTmpReg}, then branch there.
-  ldr_pcrel(kTmpReg, 2);  // 1 instruction
-  br(kTmpReg);            // 1 instruction
-  dq(target);             // 8 bytes (== 2 instructions)
+  int kOffset = ENABLE_CONTROL_FLOW_INTEGRITY_BOOL ? 3 : 2;
+  // Load from [pc + kOffset * kInstrSize] to {kTmpReg}, then branch there.
+  ldr_pcrel(kTmpReg, kOffset);  // 1 instruction
+  br(kTmpReg);                  // 1 instruction
+#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  nop();       // To keep the target below aligned to kSystemPointerSize.
+#endif
+  dq(target);  // 8 bytes (== 2 instructions)
   STATIC_ASSERT(2 * kInstrSize == kSystemPointerSize);
-  STATIC_ASSERT(kFarJumpTableSlotSize == 4 * kInstrSize);
+  const int kSlotCount = ENABLE_CONTROL_FLOW_INTEGRITY_BOOL ? 6 : 4;
+  STATIC_ASSERT(kFarJumpTableSlotSize == kSlotCount * kInstrSize);
 }
 
 // static
 void JumpTableAssembler::PatchFarJumpSlot(Address slot, Address target) {
+  // See {EmitFarJumpSlot} for the offset of the target (16 bytes with
+  // CFI enabled, 8 bytes otherwise).
+  int kTargetOffset =
+      ENABLE_CONTROL_FLOW_INTEGRITY_BOOL ? 4 * kInstrSize : 2 * kInstrSize;
   // The slot needs to be pointer-size aligned so we can atomically update it.
-  DCHECK(IsAligned(slot, kSystemPointerSize));
-  // Offset of the target is at 8 bytes, see {EmitFarJumpSlot}.
-  reinterpret_cast<std::atomic<Address>*>(slot + kSystemPointerSize)
+  DCHECK(IsAligned(slot + kTargetOffset, kSystemPointerSize));
+  reinterpret_cast<std::atomic<Address>*>(slot + kTargetOffset)
       ->store(target, std::memory_order_relaxed);
   // The data update is guaranteed to be atomic since it's a properly aligned
   // and stores a single machine word. This update will eventually be observed
diff --git a/deps/v8/src/wasm/jump-table-assembler.h b/deps/v8/src/wasm/jump-table-assembler.h
index 4aeee29e26..253f0bc018 100644
--- a/deps/v8/src/wasm/jump-table-assembler.h
+++ b/deps/v8/src/wasm/jump-table-assembler.h
@@ -20,9 +20,8 @@ namespace wasm {
 // other purposes:
 // - the far stub table contains one entry per wasm runtime stub (see
 //   {WasmCode::RuntimeStubId}, which jumps to the corresponding embedded
-//   builtin, plus (if {FLAG_wasm_far_jump_table} is enabled and not the full
-//   address space can be reached via the jump table) one entry per wasm
-//   function.
+//   builtin, plus (if not the full address space can be reached via the jump
+//   table) one entry per wasm function.
 // - the lazy compile table contains one entry per wasm function which jumps to
 //   the common {WasmCompileLazy} builtin and passes the function index that was
 //   invoked.
@@ -186,7 +185,12 @@ class V8_EXPORT_PRIVATE JumpTableAssembler : public MacroAssembler {
   static constexpr int kJumpTableSlotSize = 3 * kInstrSize;
   static constexpr int kFarJumpTableSlotSize = 2 * kInstrSize;
   static constexpr int kLazyCompileTableSlotSize = 5 * kInstrSize;
-#elif V8_TARGET_ARCH_ARM64
+#elif V8_TARGET_ARCH_ARM64 && V8_ENABLE_CONTROL_FLOW_INTEGRITY
+  static constexpr int kJumpTableLineSize = 2 * kInstrSize;
+  static constexpr int kJumpTableSlotSize = 2 * kInstrSize;
+  static constexpr int kFarJumpTableSlotSize = 6 * kInstrSize;
+  static constexpr int kLazyCompileTableSlotSize = 4 * kInstrSize;
+#elif V8_TARGET_ARCH_ARM64 && !V8_ENABLE_CONTROL_FLOW_INTEGRITY
   static constexpr int kJumpTableLineSize = 1 * kInstrSize;
   static constexpr int kJumpTableSlotSize = 1 * kInstrSize;
   static constexpr int kFarJumpTableSlotSize = 4 * kInstrSize;
diff --git a/deps/v8/src/wasm/local-decl-encoder.cc b/deps/v8/src/wasm/local-decl-encoder.cc
index ba1ebffe2c..37a210086b 100644
--- a/deps/v8/src/wasm/local-decl-encoder.cc
+++ b/deps/v8/src/wasm/local-decl-encoder.cc
@@ -29,7 +29,7 @@ size_t LocalDeclEncoder::Emit(byte* buffer) const {
   LEBHelper::write_u32v(&pos, static_cast<uint32_t>(local_decls.size()));
   for (auto& local_decl : local_decls) {
     LEBHelper::write_u32v(&pos, local_decl.first);
-    *pos = ValueTypes::ValueTypeCodeFor(local_decl.second);
+    *pos = local_decl.second.value_type_code();
     ++pos;
   }
   DCHECK_EQ(Size(), pos - buffer);
diff --git a/deps/v8/src/wasm/local-decl-encoder.h b/deps/v8/src/wasm/local-decl-encoder.h
index 6fd2314d2d..5bce05871c 100644
--- a/deps/v8/src/wasm/local-decl-encoder.h
+++ b/deps/v8/src/wasm/local-decl-encoder.h
@@ -14,11 +14,10 @@ namespace v8 {
 namespace internal {
 namespace wasm {
 
-// A helper for encoding local declarations prepended to the body of a
-// function.
+// A helper for encoding local declarations prepended to the body of a function.
 class V8_EXPORT_PRIVATE LocalDeclEncoder {
  public:
-  explicit LocalDeclEncoder(Zone* zone, FunctionSig* s = nullptr)
+  explicit LocalDeclEncoder(Zone* zone, const FunctionSig* s = nullptr)
       : sig(s), local_decls(zone), total(0) {}
 
   // Prepend local declarations by creating a new buffer and copying data
@@ -34,11 +33,11 @@ class V8_EXPORT_PRIVATE LocalDeclEncoder {
   size_t Size() const;
 
   bool has_sig() const { return sig != nullptr; }
-  FunctionSig* get_sig() const { return sig; }
-  void set_sig(FunctionSig* s) { sig = s; }
+  const FunctionSig* get_sig() const { return sig; }
+  void set_sig(const FunctionSig* s) { sig = s; }
 
  private:
-  FunctionSig* sig;
+  const FunctionSig* sig;
   ZoneVector<std::pair<uint32_t, ValueType>> local_decls;
   size_t total;
 };
diff --git a/deps/v8/src/wasm/module-compiler.cc b/deps/v8/src/wasm/module-compiler.cc
index ca5c785247..369dcfd9f7 100644
--- a/deps/v8/src/wasm/module-compiler.cc
+++ b/deps/v8/src/wasm/module-compiler.cc
@@ -381,8 +381,13 @@ class CompilationStateImpl {
   // is invoked which triggers background compilation.
   void InitializeCompilationProgress(bool lazy_module, int num_wrappers);
 
-  // Initialize compilation progress for recompilation of the whole module.
-  void InitializeRecompilationProgress(ExecutionTier tier);
+  // Initialize recompilation of the whole module: Setup compilation progress
+  // for recompilation and add the respective compilation units. The callback is
+  // called immediately if no recompilation is needed, or called later
+  // otherwise.
+  void InitializeRecompilation(
+      ExecutionTier tier,
+      CompilationState::callback_t recompilation_finished_callback);
 
   // Add the callback function to be called on compilation events. Needs to be
   // set before {AddCompilationUnits} is run to ensure that it receives all
@@ -404,11 +409,8 @@ class CompilationStateImpl {
   void FinalizeJSToWasmWrappers(Isolate* isolate, const WasmModule* module,
                                 Handle<FixedArray>* export_wrappers_out);
 
-  void OnFinishedUnits(Vector<WasmCode*>);
+  void OnFinishedUnits(Vector<WasmCode*>, Vector<WasmCompilationResult>);
   void OnFinishedJSToWasmWrapperUnits(int num);
-  void TriggerCallbacks(bool completes_baseline_compilation,
-                        bool completes_top_tier_compilation,
-                        bool completes_recompilation = false);
 
   void OnBackgroundTaskStopped(int task_id, const WasmFeatures& detected);
   void UpdateDetectedFeatures(const WasmFeatures& detected);
@@ -481,6 +483,11 @@ class CompilationStateImpl {
   }
 
  private:
+  // Trigger callbacks according to the internal counters below
+  // (outstanding_...), plus the given events.
+  // Hold the {callbacks_mutex_} when calling this method.
+  void TriggerCallbacks(base::EnumSet<CompilationEvent> additional_events = {});
+
   NativeModule* const native_module_;
   const std::shared_ptr<BackgroundCompileToken> background_compile_token_;
   const CompileMode compile_mode_;
@@ -541,11 +548,15 @@ class CompilationStateImpl {
   // Callback functions to be called on compilation events.
   std::vector<CompilationState::callback_t> callbacks_;
 
+  // Events that already happened.
+  base::EnumSet<CompilationEvent> finished_events_;
+
   int outstanding_baseline_units_ = 0;
   int outstanding_top_tier_functions_ = 0;
   std::vector<uint8_t> compilation_progress_;
 
   int outstanding_recompilation_functions_ = 0;
+  ExecutionTier recompilation_tier_;
   // End of fields protected by {callbacks_mutex_}.
   //////////////////////////////////////////////////////////////////////////////
 
@@ -553,6 +564,7 @@ class CompilationStateImpl {
   using RequiredBaselineTierField = base::BitField8<ExecutionTier, 0, 2>;
   using RequiredTopTierField = base::BitField8<ExecutionTier, 2, 2>;
   using ReachedTierField = base::BitField8<ExecutionTier, 4, 2>;
+  using ReachedRecompilationTierField = base::BitField8<ExecutionTier, 6, 2>;
 };
 
 CompilationStateImpl* Impl(CompilationState* compilation_state) {
@@ -761,8 +773,9 @@ class CompilationUnitBuilder {
     tiering_units_.emplace_back(func_index, tiers.top_tier);
   }
 
-  void AddBaselineUnit(int func_index) {
-    baseline_units_.emplace_back(func_index, ExecutionTier::kLiftoff);
+  void AddRecompilationUnit(int func_index, ExecutionTier tier) {
+    // For recompilation, just treat all units like baseline units.
+    baseline_units_.emplace_back(func_index, tier);
   }
 
   bool Commit() {
@@ -821,13 +834,8 @@ DecodeResult ValidateSingleFunction(const WasmModule* module, int func_index,
   FunctionBody body{func->sig, func->code.offset(), code.begin(), code.end()};
   DecodeResult result;
 
-  auto time_counter =
-      SELECT_WASM_COUNTER(counters, module->origin, wasm_decode, function_time);
-  TimedHistogramScope wasm_decode_function_time_scope(time_counter);
   WasmFeatures detected;
-  result = VerifyWasmCode(allocator, enabled_features, module, &detected, body);
-
-  return result;
+  return VerifyWasmCode(allocator, enabled_features, module, &detected, body);
 }
 
 enum OnlyLazyFunctions : bool {
@@ -879,12 +887,8 @@ bool CompileLazy(Isolate* isolate, NativeModule* native_module,
   Counters* counters = isolate->counters();
 
   DCHECK(!native_module->lazy_compile_frozen());
-  HistogramTimerScope lazy_time_scope(counters->wasm_lazy_compilation_time());
   NativeModuleModificationScope native_module_modification_scope(native_module);
 
-  base::ElapsedTimer compilation_timer;
-  compilation_timer.Start();
-
   TRACE_LAZY("Compiling wasm-function#%d.\n", func_index);
 
   CompilationStateImpl* compilation_state =
@@ -924,14 +928,8 @@ bool CompileLazy(Isolate* isolate, NativeModule* native_module,
 
   if (WasmCode::ShouldBeLogged(isolate)) code->LogCode(isolate);
 
-  double func_kb = 1e-3 * func->code.length();
-  double compilation_seconds = compilation_timer.Elapsed().InSecondsF();
-
   counters->wasm_lazily_compiled_functions()->Increment();
 
-  int throughput_sample = static_cast<int>(func_kb / compilation_seconds);
-  counters->wasm_lazy_compilation_throughput()->AddSample(throughput_sample);
-
   const bool lazy_module = IsLazyModule(module);
   if (GetCompileStrategy(module, enabled_features, func_index, lazy_module) ==
           CompileStrategy::kLazy &&
@@ -970,7 +968,7 @@ bool ExecuteJSToWasmWrapperCompilationUnits(
       ++num_processed_wrappers;
     }
   } while (wrapper_unit);
-  {
+  if (num_processed_wrappers > 0) {
     BackgroundCompileScope compile_scope(token);
     if (compile_scope.cancelled()) return false;
     compile_scope.compilation_state()->OnFinishedJSToWasmWrapperUnits(
@@ -991,7 +989,7 @@ bool ExecuteCompilationUnits(
   TRACE_COMPILE("Compiling (task %d)...\n", task_id);
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), "ExecuteCompilationUnits");
 
-  // Execute JS to WASM wrapper units first, so that they are ready to be
+  // Execute JS to Wasm wrapper units first, so that they are ready to be
   // finalized by the main thread when the kFinishedBaselineCompilation event is
   // triggered.
   if (!ExecuteJSToWasmWrapperCompilationUnits(token)) {
@@ -1069,7 +1067,8 @@ bool ExecuteCompilationUnits(
       DCHECK_LE(0, func_index);
       DCHECK_LT(func_index, native_module->num_functions());
       if (func_index < num_imported_functions) {
-        FunctionSig* sig = native_module->module()->functions[func_index].sig;
+        const FunctionSig* sig =
+            native_module->module()->functions[func_index].sig;
         WasmImportWrapperCache::CacheKey key(compiler::kDefaultImportCallKind,
                                              sig);
         // If two imported functions have the same key, only one of them should
@@ -1083,7 +1082,8 @@ bool ExecuteCompilationUnits(
 
     native_module->engine()->LogCode(VectorOf(code_vector));
 
-    compile_scope->compilation_state()->OnFinishedUnits(VectorOf(code_vector));
+    compile_scope->compilation_state()->OnFinishedUnits(
+        VectorOf(code_vector), VectorOf(results_to_publish));
     results_to_publish.clear();
   };
 
@@ -1165,7 +1165,7 @@ int AddImportWrapperUnits(NativeModule* native_module,
       keys;
   int num_imported_functions = native_module->num_imported_functions();
   for (int func_index = 0; func_index < num_imported_functions; func_index++) {
-    FunctionSig* sig = native_module->module()->functions[func_index].sig;
+    const FunctionSig* sig = native_module->module()->functions[func_index].sig;
     if (!IsJSCompatibleSignature(sig, native_module->enabled_features())) {
       continue;
     }
@@ -1188,10 +1188,15 @@ void InitializeCompilationUnits(Isolate* isolate, NativeModule* native_module) {
   ModuleWireBytes wire_bytes(native_module->wire_bytes());
   CompilationUnitBuilder builder(native_module);
   auto* module = native_module->module();
+  const bool prefer_liftoff = native_module->IsTieredDown();
 
   uint32_t start = module->num_imported_functions;
   uint32_t end = start + module->num_declared_functions;
   for (uint32_t func_index = start; func_index < end; func_index++) {
+    if (prefer_liftoff) {
+      builder.AddRecompilationUnit(func_index, ExecutionTier::kLiftoff);
+      continue;
+    }
     CompileStrategy strategy = GetCompileStrategy(
         module, native_module->enabled_features(), func_index, lazy_module);
     if (strategy == CompileStrategy::kLazy) {
@@ -1213,19 +1218,6 @@ void InitializeCompilationUnits(Isolate* isolate, NativeModule* native_module) {
   builder.Commit();
 }
 
-void AddBaselineCompilationUnits(NativeModule* native_module) {
-  CompilationUnitBuilder builder(native_module);
-  auto* module = native_module->module();
-
-  uint32_t start = module->num_imported_functions;
-  uint32_t end = start + module->num_declared_functions;
-  for (uint32_t func_index = start; func_index < end; func_index++) {
-    builder.AddBaselineUnit(func_index);
-  }
-
-  builder.Commit();
-}
-
 bool MayCompriseLazyFunctions(const WasmModule* module,
                               const WasmFeatures& enabled_features,
                               bool lazy_module) {
@@ -1377,8 +1369,8 @@ std::shared_ptr<NativeModule> CompileToNativeModule(
     Handle<FixedArray>* export_wrappers_out) {
   const WasmModule* wasm_module = module.get();
   std::shared_ptr<NativeModule> native_module =
-      isolate->wasm_engine()->MaybeGetNativeModule(wasm_module->origin,
-                                                   wire_bytes.module_bytes());
+      isolate->wasm_engine()->MaybeGetNativeModule(
+          wasm_module->origin, wire_bytes.module_bytes(), isolate);
   if (native_module) {
     // TODO(thibaudm): Look into sharing export wrappers.
     CompileJsToWasmWrappers(isolate, wasm_module, export_wrappers_out);
@@ -1401,14 +1393,18 @@ std::shared_ptr<NativeModule> CompileToNativeModule(
       wasm::WasmCodeManager::EstimateNativeModuleCodeSize(module.get(),
                                                           uses_liftoff);
   native_module = isolate->wasm_engine()->NewNativeModule(
-      isolate, enabled, std::move(module), code_size_estimate);
+      isolate, enabled, module, code_size_estimate);
   native_module->SetWireBytes(std::move(wire_bytes_copy));
 
   CompileNativeModule(isolate, thrower, wasm_module, native_module.get());
-  isolate->wasm_engine()->UpdateNativeModuleCache(native_module,
-                                                  thrower->error());
+  bool cache_hit = !isolate->wasm_engine()->UpdateNativeModuleCache(
+      thrower->error(), &native_module, isolate);
   if (thrower->error()) return {};
 
+  if (cache_hit) {
+    CompileJsToWasmWrappers(isolate, wasm_module, export_wrappers_out);
+    return native_module;
+  }
   Impl(native_module->compilation_state())
       ->FinalizeJSToWasmWrappers(isolate, native_module->module(),
                                  export_wrappers_out);
@@ -1424,33 +1420,33 @@ void RecompileNativeModule(Isolate* isolate, NativeModule* native_module,
   // Install a callback to notify us once background recompilation finished.
   auto recompilation_finished_semaphore = std::make_shared<base::Semaphore>(0);
   auto* compilation_state = Impl(native_module->compilation_state());
-  DCHECK_EQ(tier, ExecutionTier::kLiftoff);
+  DCHECK(tier == ExecutionTier::kTurbofan || tier == ExecutionTier::kLiftoff);
   // The callback captures a shared ptr to the semaphore.
-  compilation_state->AddCallback(
-      [recompilation_finished_semaphore](CompilationEvent event) {
+  // Initialize the compilation units and kick off background compile tasks.
+  compilation_state->InitializeRecompilation(
+      tier, [recompilation_finished_semaphore](CompilationEvent event) {
         if (event == CompilationEvent::kFinishedRecompilation) {
           recompilation_finished_semaphore->Signal();
         }
       });
 
-  // Initialize the compilation units and kick off background compile tasks.
-  compilation_state->InitializeRecompilationProgress(tier);
-  AddBaselineCompilationUnits(native_module);
-
-  // The main thread contributes to the compilation, except if we need
-  // deterministic compilation; in that case, the single background task will
-  // execute all compilation.
-  if (!NeedsDeterministicCompile()) {
-    while (ExecuteCompilationUnits(
-        compilation_state->background_compile_token(), isolate->counters(),
-        kMainThreadTaskId, kBaselineOnly)) {
-      // Continue executing compilation units.
+  // For tier down only.
+  if (tier == ExecutionTier::kLiftoff) {
+    // The main thread contributes to the compilation, except if we need
+    // deterministic compilation; in that case, the single background task will
+    // execute all compilation.
+    if (!NeedsDeterministicCompile()) {
+      while (ExecuteCompilationUnits(
+          compilation_state->background_compile_token(), isolate->counters(),
+          kMainThreadTaskId, kBaselineOnly)) {
+        // Continue executing compilation units.
+      }
     }
-  }
 
-  // Now wait until baseline recompilation finished.
-  recompilation_finished_semaphore->Wait();
-  DCHECK(!compilation_state->failed());
+    // Now wait until baseline recompilation finished.
+    recompilation_finished_semaphore->Wait();
+    DCHECK(!compilation_state->failed());
+  }
 }
 
 AsyncCompileJob::AsyncCompileJob(
@@ -1488,7 +1484,11 @@ void AsyncCompileJob::Abort() {
 
 class AsyncStreamingProcessor final : public StreamingProcessor {
  public:
-  explicit AsyncStreamingProcessor(AsyncCompileJob* job);
+  explicit AsyncStreamingProcessor(AsyncCompileJob* job,
+                                   std::shared_ptr<Counters> counters,
+                                   AccountingAllocator* allocator);
+
+  ~AsyncStreamingProcessor();
 
   bool ProcessModuleHeader(Vector<const uint8_t> bytes,
                            uint32_t offset) override;
@@ -1525,12 +1525,21 @@ class AsyncStreamingProcessor final : public StreamingProcessor {
   WasmEngine* wasm_engine_;
   std::unique_ptr<CompilationUnitBuilder> compilation_unit_builder_;
   int num_functions_ = 0;
+  bool prefix_cache_hit_ = false;
+  bool before_code_section_ = true;
+  std::shared_ptr<Counters> async_counters_;
+  AccountingAllocator* allocator_;
+
+  // Running hash of the wire bytes up to code section size, but excluding the
+  // code section itself. Used by the {NativeModuleCache} to detect potential
+  // duplicate modules.
+  size_t prefix_hash_;
 };
 
 std::shared_ptr<StreamingDecoder> AsyncCompileJob::CreateStreamingDecoder() {
   DCHECK_NULL(stream_);
-  stream_.reset(
-      new StreamingDecoder(std::make_unique<AsyncStreamingProcessor>(this)));
+  stream_.reset(new StreamingDecoder(std::make_unique<AsyncStreamingProcessor>(
+      this, isolate_->async_counters(), isolate_->allocator())));
   return stream_;
 }
 
@@ -1566,16 +1575,21 @@ void AsyncCompileJob::CreateNativeModule(
 
   // Create the module object and populate with compiled functions and
   // information needed at instantiation time.
-  // TODO(clemensb): For the same module (same bytes / same hash), we should
-  // only have one {WasmModuleObject}. Otherwise, we might only set
-  // breakpoints on a (potentially empty) subset of the instances.
-  // Create the module object.
 
   native_module_ = isolate_->wasm_engine()->NewNativeModule(
       isolate_, enabled_features_, std::move(module), code_size_estimate);
   native_module_->SetWireBytes({std::move(bytes_copy_), wire_bytes_.length()});
+}
 
-  if (stream_) stream_->NotifyNativeModuleCreated(native_module_);
+bool AsyncCompileJob::GetOrCreateNativeModule(
+    std::shared_ptr<const WasmModule> module, size_t code_size_estimate) {
+  native_module_ = isolate_->wasm_engine()->MaybeGetNativeModule(
+      module->origin, wire_bytes_.module_bytes(), isolate_);
+  if (native_module_ == nullptr) {
+    CreateNativeModule(std::move(module), code_size_estimate);
+    return false;
+  }
+  return true;
 }
 
 void AsyncCompileJob::PrepareRuntimeObjects() {
@@ -1584,9 +1598,9 @@ void AsyncCompileJob::PrepareRuntimeObjects() {
   DCHECK(module_object_.is_null());
   const WasmModule* module = native_module_->module();
   auto source_url = stream_ ? stream_->url() : Vector<const char>();
-  Handle<Script> script =
-      CreateWasmScript(isolate_, wire_bytes_, VectorOf(module->source_map_url),
-                       module->name, source_url);
+  Handle<Script> script = CreateWasmScript(
+      isolate_, native_module_->wire_bytes(), VectorOf(module->source_map_url),
+      module->name, source_url);
 
   Handle<WasmModuleObject> module_object =
       WasmModuleObject::New(isolate_, native_module_, script);
@@ -1596,11 +1610,15 @@ void AsyncCompileJob::PrepareRuntimeObjects() {
 
 // This function assumes that it is executed in a HandleScope, and that a
 // context is set on the isolate.
-void AsyncCompileJob::FinishCompile() {
+void AsyncCompileJob::FinishCompile(bool is_after_cache_hit) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"),
                "AsyncCompileJob::FinishCompile");
   bool is_after_deserialization = !module_object_.is_null();
+  auto compilation_state = Impl(native_module_->compilation_state());
   if (!is_after_deserialization) {
+    if (stream_) {
+      stream_->NotifyNativeModuleCreated(native_module_);
+    }
     PrepareRuntimeObjects();
   }
 
@@ -1627,14 +1645,18 @@ void AsyncCompileJob::FinishCompile() {
     isolate_->debug()->OnAfterCompile(script);
   }
 
-  auto compilation_state =
-      Impl(module_object_->native_module()->compilation_state());
   // TODO(bbudge) Allow deserialization without wrapper compilation, so we can
   // just compile wrappers here.
   if (!is_after_deserialization) {
     Handle<FixedArray> export_wrappers;
-    compilation_state->FinalizeJSToWasmWrappers(
-        isolate_, module_object_->module(), &export_wrappers);
+    if (is_after_cache_hit) {
+      // TODO(thibaudm): Look into sharing wrappers.
+      CompileJsToWasmWrappers(isolate_, module_object_->module(),
+                              &export_wrappers);
+    } else {
+      compilation_state->FinalizeJSToWasmWrappers(
+          isolate_, module_object_->module(), &export_wrappers);
+    }
     module_object_->set_export_wrappers(*export_wrappers);
   }
   // We can only update the feature counts once the entire compile is done.
@@ -1682,12 +1704,16 @@ class AsyncCompileJob::CompilationStateCallback {
       case CompilationEvent::kFinishedBaselineCompilation:
         DCHECK(!last_event_.has_value());
         if (job_->DecrementAndCheckFinisherCount()) {
-          // TODO(v8:6847): Also share streaming compilation result.
-          if (job_->stream_ == nullptr) {
-            job_->isolate_->wasm_engine()->UpdateNativeModuleCache(
-                job_->native_module_, false);
-          }
-          job_->DoSync<CompileFinished>();
+          // Install the native module in the cache, or reuse a conflicting one.
+          // If we get a conflicting module, wait until we are back in the
+          // main thread to update {job_->native_module_} to avoid a data race.
+          std::shared_ptr<NativeModule> native_module = job_->native_module_;
+          bool cache_hit =
+              !job_->isolate_->wasm_engine()->UpdateNativeModuleCache(
+                  false, &native_module, job_->isolate_);
+          DCHECK_EQ(cache_hit, native_module != job_->native_module_);
+          job_->DoSync<CompileFinished>(cache_hit ? std::move(native_module)
+                                                  : nullptr);
         }
         break;
       case CompilationEvent::kFinishedTopTierCompilation:
@@ -1698,11 +1724,8 @@ class AsyncCompileJob::CompilationStateCallback {
       case CompilationEvent::kFailedCompilation:
         DCHECK(!last_event_.has_value());
         if (job_->DecrementAndCheckFinisherCount()) {
-          // TODO(v8:6847): Also share streaming compilation result.
-          if (job_->stream_ == nullptr) {
-            job_->isolate_->wasm_engine()->UpdateNativeModuleCache(
-                job_->native_module_, true);
-          }
+          job_->isolate_->wasm_engine()->UpdateNativeModuleCache(
+              true, &job_->native_module_, job_->isolate_);
           job_->DoSync<CompileFailed>();
         }
         break;
@@ -1959,29 +1982,20 @@ class AsyncCompileJob::PrepareAndStartCompile : public CompileStep {
   void RunInForeground(AsyncCompileJob* job) override {
     TRACE_COMPILE("(2) Prepare and start compile...\n");
 
-    // TODO(v8:6847): Also share streaming compilation result.
-    if (job->stream_ == nullptr) {
-      auto cached_native_module =
-          job->isolate_->wasm_engine()->MaybeGetNativeModule(
-              module_->origin, job->wire_bytes_.module_bytes());
-      if (cached_native_module != nullptr) {
-        job->native_module_ = std::move(cached_native_module);
-        job->PrepareRuntimeObjects();
-        Handle<FixedArray> export_wrappers;
-        CompileJsToWasmWrappers(job->isolate_, job->native_module_->module(),
-                                &export_wrappers);
-        job->module_object_->set_export_wrappers(*export_wrappers);
-        job->FinishCompile();
-        return;
-      }
+    const bool streaming = job->wire_bytes_.length() == 0;
+    if (streaming) {
+      // Streaming compilation already checked for cache hits.
+      job->CreateNativeModule(module_, code_size_estimate_);
+    } else if (job->GetOrCreateNativeModule(std::move(module_),
+                                            code_size_estimate_)) {
+      job->FinishCompile(true);
+      return;
     }
 
     // Make sure all compilation tasks stopped running. Decoding (async step)
     // is done.
     job->background_task_manager_.CancelAndWait();
 
-    job->CreateNativeModule(module_, code_size_estimate_);
-
     CompilationStateImpl* compilation_state =
         Impl(job->native_module_->compilation_state());
     compilation_state->AddCallback(CompilationStateCallback{job});
@@ -2027,10 +2041,7 @@ class SampleTopTierCodeSizeCallback {
       : native_module_(std::move(native_module)) {}
 
   void operator()(CompilationEvent event) {
-    // This callback is registered after baseline compilation finished, so the
-    // only possible event to follow is {kFinishedTopTierCompilation}.
-    if (event == CompilationEvent::kFinishedRecompilation) return;
-    DCHECK_EQ(CompilationEvent::kFinishedTopTierCompilation, event);
+    if (event != CompilationEvent::kFinishedTopTierCompilation) return;
     if (std::shared_ptr<NativeModule> native_module = native_module_.lock()) {
       native_module->engine()->SampleTopTierCodeSizeInAllIsolates(
           native_module);
@@ -2046,20 +2057,30 @@ class SampleTopTierCodeSizeCallback {
 // Step 3b (sync): Compilation finished.
 //==========================================================================
 class AsyncCompileJob::CompileFinished : public CompileStep {
+ public:
+  explicit CompileFinished(std::shared_ptr<NativeModule> cached_native_module)
+      : cached_native_module_(std::move(cached_native_module)) {}
+
  private:
   void RunInForeground(AsyncCompileJob* job) override {
     TRACE_COMPILE("(3b) Compilation finished\n");
-    DCHECK(!job->native_module_->compilation_state()->failed());
-    // Sample the generated code size when baseline compilation finished.
-    job->native_module_->SampleCodeSize(job->isolate_->counters(),
-                                        NativeModule::kAfterBaseline);
-    // Also, set a callback to sample the code size after top-tier compilation
-    // finished. This callback will *not* keep the NativeModule alive.
-    job->native_module_->compilation_state()->AddCallback(
-        SampleTopTierCodeSizeCallback{job->native_module_});
+    if (cached_native_module_) {
+      job->native_module_ = cached_native_module_;
+    } else {
+      DCHECK(!job->native_module_->compilation_state()->failed());
+      // Sample the generated code size when baseline compilation finished.
+      job->native_module_->SampleCodeSize(job->isolate_->counters(),
+                                          NativeModule::kAfterBaseline);
+      // Also, set a callback to sample the code size after top-tier compilation
+      // finished. This callback will *not* keep the NativeModule alive.
+      job->native_module_->compilation_state()->AddCallback(
+          SampleTopTierCodeSizeCallback{job->native_module_});
+    }
     // Then finalize and publish the generated module.
-    job->FinishCompile();
+    job->FinishCompile(cached_native_module_ != nullptr);
   }
+
+  std::shared_ptr<NativeModule> cached_native_module_;
 };
 
 void AsyncCompileJob::FinishModule() {
@@ -2068,11 +2089,22 @@ void AsyncCompileJob::FinishModule() {
   isolate_->wasm_engine()->RemoveCompileJob(this);
 }
 
-AsyncStreamingProcessor::AsyncStreamingProcessor(AsyncCompileJob* job)
+AsyncStreamingProcessor::AsyncStreamingProcessor(
+    AsyncCompileJob* job, std::shared_ptr<Counters> async_counters,
+    AccountingAllocator* allocator)
     : decoder_(job->enabled_features_),
       job_(job),
       wasm_engine_(job_->isolate_->wasm_engine()),
-      compilation_unit_builder_(nullptr) {}
+      compilation_unit_builder_(nullptr),
+      async_counters_(async_counters),
+      allocator_(allocator) {}
+
+AsyncStreamingProcessor::~AsyncStreamingProcessor() {
+  if (job_->native_module_ && job_->native_module_->wire_bytes().empty()) {
+    // Clean up the temporary cache entry.
+    job_->isolate_->wasm_engine()->StreamingCompilationFailed(prefix_hash_);
+  }
+}
 
 void AsyncStreamingProcessor::FinishAsyncCompileJobWithError(
     const WasmError& error) {
@@ -2109,6 +2141,7 @@ bool AsyncStreamingProcessor::ProcessModuleHeader(Vector<const uint8_t> bytes,
     FinishAsyncCompileJobWithError(decoder_.FinishDecoding(false).error());
     return false;
   }
+  prefix_hash_ = NativeModuleCache::WireBytesHash(bytes);
   return true;
 }
 
@@ -2123,17 +2156,25 @@ bool AsyncStreamingProcessor::ProcessSection(SectionCode section_code,
     CommitCompilationUnits();
     compilation_unit_builder_.reset();
   }
+  if (before_code_section_) {
+    // Combine section hashes until code section.
+    prefix_hash_ = base::hash_combine(prefix_hash_,
+                                      NativeModuleCache::WireBytesHash(bytes));
+  }
   if (section_code == SectionCode::kUnknownSectionCode) {
-    Decoder decoder(bytes, offset);
-    section_code = ModuleDecoder::IdentifyUnknownSection(
-        &decoder, bytes.begin() + bytes.length());
+    size_t bytes_consumed = ModuleDecoder::IdentifyUnknownSection(
+        &decoder_, bytes, offset, &section_code);
+    if (!decoder_.ok()) {
+      FinishAsyncCompileJobWithError(decoder_.FinishDecoding(false).error());
+      return false;
+    }
     if (section_code == SectionCode::kUnknownSectionCode) {
       // Skip unknown sections that we do not know how to handle.
       return true;
     }
     // Remove the unknown section tag from the payload bytes.
-    offset += decoder.position();
-    bytes = bytes.SubVector(decoder.position(), bytes.size());
+    offset += bytes_consumed;
+    bytes = bytes.SubVector(bytes_consumed, bytes.size());
   }
   constexpr bool verify_functions = false;
   decoder_.DecodeSection(section_code, bytes, offset, verify_functions);
@@ -2149,6 +2190,8 @@ bool AsyncStreamingProcessor::ProcessCodeSectionHeader(
     int num_functions, uint32_t offset,
     std::shared_ptr<WireBytesStorage> wire_bytes_storage,
     int code_section_length) {
+  DCHECK_LE(0, code_section_length);
+  before_code_section_ = false;
   TRACE_STREAMING("Start the code section with %d functions...\n",
                   num_functions);
   if (!decoder_.CheckFunctionsCount(static_cast<uint32_t>(num_functions),
@@ -2156,6 +2199,15 @@ bool AsyncStreamingProcessor::ProcessCodeSectionHeader(
     FinishAsyncCompileJobWithError(decoder_.FinishDecoding(false).error());
     return false;
   }
+
+  prefix_hash_ = base::hash_combine(prefix_hash_,
+                                    static_cast<uint32_t>(code_section_length));
+  if (!wasm_engine_->GetStreamingCompilationOwnership(prefix_hash_)) {
+    // Known prefix, wait until the end of the stream and check the cache.
+    prefix_cache_hit_ = true;
+    return true;
+  }
+
   // Execute the PrepareAndStartCompile step immediately and not in a separate
   // task.
   int num_imported_functions =
@@ -2168,6 +2220,8 @@ bool AsyncStreamingProcessor::ProcessCodeSectionHeader(
           uses_liftoff);
   job_->DoImmediately<AsyncCompileJob::PrepareAndStartCompile>(
       decoder_.shared_module(), false, code_size_estimate);
+
+  decoder_.set_code_section(offset, static_cast<uint32_t>(code_section_length));
   auto* compilation_state = Impl(job_->native_module_->compilation_state());
   compilation_state->SetWireBytesStorage(std::move(wire_bytes_storage));
   DCHECK_EQ(job_->native_module_->module()->origin, kWasmOrigin);
@@ -2199,14 +2253,12 @@ bool AsyncStreamingProcessor::ProcessFunctionBody(Vector<const uint8_t> bytes,
   decoder_.DecodeFunctionBody(
       num_functions_, static_cast<uint32_t>(bytes.length()), offset, false);
 
-  NativeModule* native_module = job_->native_module_.get();
-  const WasmModule* module = native_module->module();
+  const WasmModule* module = decoder_.module();
   auto enabled_features = job_->enabled_features_;
   uint32_t func_index =
       num_functions_ + decoder_.module()->num_imported_functions;
   DCHECK_EQ(module->origin, kWasmOrigin);
   const bool lazy_module = job_->wasm_lazy_compilation_;
-
   CompileStrategy strategy =
       GetCompileStrategy(module, enabled_features, func_index, lazy_module);
   bool validate_lazily_compiled_function =
@@ -2214,13 +2266,11 @@ bool AsyncStreamingProcessor::ProcessFunctionBody(Vector<const uint8_t> bytes,
       (strategy == CompileStrategy::kLazy ||
        strategy == CompileStrategy::kLazyBaselineEagerTopTier);
   if (validate_lazily_compiled_function) {
-    Counters* counters = Impl(native_module->compilation_state())->counters();
-    AccountingAllocator* allocator = native_module->engine()->allocator();
-
     // The native module does not own the wire bytes until {SetWireBytes} is
     // called in {OnFinishedStream}. Validation must use {bytes} parameter.
-    DecodeResult result = ValidateSingleFunction(
-        module, func_index, bytes, counters, allocator, enabled_features);
+    DecodeResult result =
+        ValidateSingleFunction(module, func_index, bytes, async_counters_.get(),
+                               allocator_, enabled_features);
 
     if (result.failed()) {
       FinishAsyncCompileJobWithError(result.error());
@@ -2228,6 +2278,13 @@ bool AsyncStreamingProcessor::ProcessFunctionBody(Vector<const uint8_t> bytes,
     }
   }
 
+  // Don't compile yet if we might have a cache hit.
+  if (prefix_cache_hit_) {
+    num_functions_++;
+    return true;
+  }
+
+  NativeModule* native_module = job_->native_module_.get();
   if (strategy == CompileStrategy::kLazy) {
     native_module->UseLazyStub(func_index);
   } else if (strategy == CompileStrategy::kLazyBaselineEagerTopTier) {
@@ -2256,11 +2313,27 @@ void AsyncStreamingProcessor::OnFinishedChunk() {
 // Finish the processing of the stream.
 void AsyncStreamingProcessor::OnFinishedStream(OwnedVector<uint8_t> bytes) {
   TRACE_STREAMING("Finish stream...\n");
+  DCHECK_EQ(NativeModuleCache::PrefixHash(bytes.as_vector()), prefix_hash_);
   ModuleResult result = decoder_.FinishDecoding(false);
   if (result.failed()) {
     FinishAsyncCompileJobWithError(result.error());
     return;
   }
+
+  job_->wire_bytes_ = ModuleWireBytes(bytes.as_vector());
+  job_->bytes_copy_ = bytes.ReleaseData();
+
+  if (prefix_cache_hit_) {
+    // Restart as an asynchronous, non-streaming compilation. Most likely
+    // {PrepareAndStartCompile} will get the native module from the cache.
+    size_t code_size_estimate =
+        wasm::WasmCodeManager::EstimateNativeModuleCodeSize(
+            result.value().get(), FLAG_liftoff);
+    job_->DoSync<AsyncCompileJob::PrepareAndStartCompile>(
+        std::move(result).value(), true, code_size_estimate);
+    return;
+  }
+
   // We have to open a HandleScope and prepare the Context for
   // CreateNativeModule, PrepareRuntimeObjects and FinishCompile as this is a
   // callback from the embedder.
@@ -2270,23 +2343,33 @@ void AsyncStreamingProcessor::OnFinishedStream(OwnedVector<uint8_t> bytes) {
   // Record the size of the wire bytes. In synchronous and asynchronous
   // (non-streaming) compilation, this happens in {DecodeWasmModule}.
   auto* histogram = job_->isolate_->counters()->wasm_wasm_module_size_bytes();
-  histogram->AddSample(static_cast<int>(bytes.size()));
+  histogram->AddSample(job_->wire_bytes_.module_bytes().length());
 
-  bool needs_finish = job_->DecrementAndCheckFinisherCount();
-  if (job_->native_module_ == nullptr) {
+  const bool has_code_section = job_->native_module_ != nullptr;
+  bool cache_hit = false;
+  if (!has_code_section) {
     // We are processing a WebAssembly module without code section. Create the
-    // runtime objects now (would otherwise happen in {PrepareAndStartCompile}).
+    // native module now (would otherwise happen in {PrepareAndStartCompile} or
+    // {ProcessCodeSectionHeader}).
     constexpr size_t kCodeSizeEstimate = 0;
-    job_->CreateNativeModule(std::move(result).value(), kCodeSizeEstimate);
-    DCHECK(needs_finish);
+    cache_hit = job_->GetOrCreateNativeModule(std::move(result).value(),
+                                              kCodeSizeEstimate);
+  } else {
+    job_->native_module_->SetWireBytes(
+        {std::move(job_->bytes_copy_), job_->wire_bytes_.length()});
   }
-  job_->wire_bytes_ = ModuleWireBytes(bytes.as_vector());
-  job_->native_module_->SetWireBytes(std::move(bytes));
+  const bool needs_finish = job_->DecrementAndCheckFinisherCount();
+  DCHECK_IMPLIES(!has_code_section, needs_finish);
   if (needs_finish) {
-    if (job_->native_module_->compilation_state()->failed()) {
+    const bool failed = job_->native_module_->compilation_state()->failed();
+    if (!cache_hit) {
+      cache_hit = !job_->isolate_->wasm_engine()->UpdateNativeModuleCache(
+          failed, &job_->native_module_, job_->isolate_);
+    }
+    if (failed) {
       job_->AsyncCompileFailed();
     } else {
-      job_->FinishCompile();
+      job_->FinishCompile(cache_hit);
     }
   }
 }
@@ -2318,7 +2401,7 @@ bool AsyncStreamingProcessor::Deserialize(Vector<const uint8_t> module_bytes,
       job_->isolate_->global_handles()->Create(*result.ToHandleChecked());
   job_->native_module_ = job_->module_object_->shared_native_module();
   job_->wire_bytes_ = ModuleWireBytes(job_->native_module_->wire_bytes());
-  job_->FinishCompile();
+  job_->FinishCompile(false);
   return true;
 }
 
@@ -2368,7 +2451,21 @@ void CompilationStateImpl::InitializeCompilationProgress(bool lazy_module,
   compilation_progress_.reserve(module->num_declared_functions);
   int start = module->num_imported_functions;
   int end = start + module->num_declared_functions;
+
+  const bool prefer_liftoff = native_module_->IsTieredDown();
   for (int func_index = start; func_index < end; func_index++) {
+    if (prefer_liftoff) {
+      constexpr uint8_t kLiftoffOnlyFunctionProgress =
+          RequiredTopTierField::update(
+              RequiredBaselineTierField::update(
+                  ReachedTierField::encode(ExecutionTier::kNone),
+                  ExecutionTier::kLiftoff),
+              ExecutionTier::kLiftoff);
+      compilation_progress_.push_back(kLiftoffOnlyFunctionProgress);
+      outstanding_baseline_units_++;
+      outstanding_top_tier_functions_++;
+      continue;
+    }
     ExecutionTierPair requested_tiers = GetRequestedExecutionTiers(
         module, compile_mode(), enabled_features, func_index);
     CompileStrategy strategy =
@@ -2419,40 +2516,72 @@ void CompilationStateImpl::InitializeCompilationProgress(bool lazy_module,
   }
 }
 
-void CompilationStateImpl::InitializeRecompilationProgress(ExecutionTier tier) {
+void CompilationStateImpl::InitializeRecompilation(
+    ExecutionTier tier,
+    CompilationState::callback_t recompilation_finished_callback) {
   DCHECK(!failed());
-  auto* module = native_module_->module();
 
-  base::MutexGuard guard(&callbacks_mutex_);
-  // Ensure that we don't trigger recompilation if another recompilation is
-  // already happening.
-  DCHECK_EQ(0, outstanding_recompilation_functions_);
-  int start = module->num_imported_functions;
-  int end = start + module->num_declared_functions;
-  for (int function_index = start; function_index < end; function_index++) {
-    int slot_index = function_index - start;
-    DCHECK_LT(slot_index, compilation_progress_.size());
-    ExecutionTier reached_tier =
-        ReachedTierField::decode(compilation_progress_[slot_index]);
-    if (reached_tier != tier) {
-      outstanding_recompilation_functions_++;
+  // Generate necessary compilation units on the fly.
+  CompilationUnitBuilder builder(native_module_);
+
+  {
+    base::MutexGuard guard(&callbacks_mutex_);
+
+    // Restart recompilation if another recompilation is already happening.
+    outstanding_recompilation_functions_ = 0;
+    // If compilation hasn't started yet then code would be keep as tiered-down
+    // and don't need to recompile.
+    if (compilation_progress_.size() > 0) {
+      int start = native_module_->module()->num_imported_functions;
+      int end = start + native_module_->module()->num_declared_functions;
+      for (int function_index = start; function_index < end; function_index++) {
+        int slot_index = function_index - start;
+        DCHECK_LT(slot_index, compilation_progress_.size());
+        ExecutionTier reached_tier =
+            ReachedTierField::decode(compilation_progress_[slot_index]);
+        bool has_correct_tier =
+            reached_tier == tier &&
+            native_module_->HasCodeWithTier(function_index, tier);
+        compilation_progress_[slot_index] =
+            ReachedRecompilationTierField::update(
+                compilation_progress_[slot_index],
+                has_correct_tier ? tier : ExecutionTier::kNone);
+        if (!has_correct_tier) {
+          outstanding_recompilation_functions_++;
+          builder.AddRecompilationUnit(function_index, tier);
+        }
+      }
     }
-  }
-  DCHECK_LE(0, outstanding_recompilation_functions_);
-  DCHECK_LE(outstanding_recompilation_functions_,
-            module->num_declared_functions);
 
-  // Trigger callbacks if module needs no recompilation.
-  if (outstanding_recompilation_functions_ == 0) {
-    for (auto& callback : callbacks_) {
-      callback(CompilationEvent::kFinishedRecompilation);
+    // Trigger callback if module needs no recompilation. Add to the list of
+    // callbacks (to be called later) otherwise.
+    if (outstanding_recompilation_functions_ == 0) {
+      recompilation_finished_callback(CompilationEvent::kFinishedRecompilation);
+    } else {
+      callbacks_.emplace_back(std::move(recompilation_finished_callback));
+      recompilation_tier_ = tier;
     }
   }
+
+  builder.Commit();
 }
 
 void CompilationStateImpl::AddCallback(CompilationState::callback_t callback) {
   base::MutexGuard callbacks_guard(&callbacks_mutex_);
-  callbacks_.emplace_back(std::move(callback));
+  // Immediately trigger events that already happened.
+  for (auto event : {CompilationEvent::kFinishedBaselineCompilation,
+                     CompilationEvent::kFinishedTopTierCompilation,
+                     CompilationEvent::kFailedCompilation}) {
+    if (finished_events_.contains(event)) {
+      callback(event);
+    }
+  }
+  constexpr base::EnumSet<CompilationEvent> kFinalEvents{
+      CompilationEvent::kFinishedTopTierCompilation,
+      CompilationEvent::kFailedCompilation};
+  if (!finished_events_.contains_any(kFinalEvents)) {
+    callbacks_.emplace_back(std::move(callback));
+  }
 }
 
 void CompilationStateImpl::AddCompilationUnits(
@@ -2511,7 +2640,8 @@ CompilationStateImpl::GetNextCompilationUnit(
   return compilation_unit_queues_.GetNextUnit(task_id, baseline_only);
 }
 
-void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
+void CompilationStateImpl::OnFinishedUnits(
+    Vector<WasmCode*> code_vector, Vector<WasmCompilationResult> results) {
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), "OnFinishedUnits",
                "num_units", code_vector.size());
 
@@ -2536,11 +2666,10 @@ void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
   DCHECK_EQ(compilation_progress_.size(),
             native_module_->module()->num_declared_functions);
 
-  bool completes_baseline_compilation = false;
-  bool completes_top_tier_compilation = false;
-  bool completes_recompilation = false;
+  base::EnumSet<CompilationEvent> triggered_events;
 
-  for (WasmCode* code : code_vector) {
+  for (size_t i = 0; i < code_vector.size(); i++) {
+    WasmCode* code = code_vector[i];
     DCHECK_NOT_NULL(code);
     DCHECK_LT(code->index(), native_module_->num_functions());
 
@@ -2548,9 +2677,6 @@ void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
       // Import wrapper.
       DCHECK_EQ(code->tier(), ExecutionTier::kTurbofan);
       outstanding_baseline_units_--;
-      if (outstanding_baseline_units_ == 0) {
-        completes_baseline_compilation = true;
-      }
     } else {
       // Function.
       DCHECK_NE(code->tier(), ExecutionTier::kNone);
@@ -2573,17 +2699,11 @@ void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
           required_baseline_tier <= code->tier()) {
         DCHECK_GT(outstanding_baseline_units_, 0);
         outstanding_baseline_units_--;
-        if (outstanding_baseline_units_ == 0) {
-          completes_baseline_compilation = true;
-        }
       }
       if (reached_tier < required_top_tier &&
           required_top_tier <= code->tier()) {
         DCHECK_GT(outstanding_top_tier_functions_, 0);
         outstanding_top_tier_functions_--;
-        if (outstanding_top_tier_functions_ == 0) {
-          completes_top_tier_compilation = true;
-        }
       }
 
       // If there is recompilation in progress, we would only count the
@@ -2591,62 +2711,75 @@ void CompilationStateImpl::OnFinishedUnits(Vector<WasmCode*> code_vector) {
       // counter once a function reaches Liftoff.
       if (outstanding_recompilation_functions_ > 0) {
         // TODO(duongn): extend this logic for tier up.
-        if (code->tier() == ExecutionTier::kLiftoff &&
-            reached_tier != ExecutionTier::kLiftoff) {
+        ExecutionTier recompilation_tier =
+            ReachedRecompilationTierField::decode(function_progress);
+        if (results[i].requested_tier == recompilation_tier_ &&
+            recompilation_tier == ExecutionTier::kNone) {
+          DCHECK(code->tier() >= recompilation_tier_);
           outstanding_recompilation_functions_--;
-          // Update function's compilation progress.
-          compilation_progress_[slot_index] = ReachedTierField::update(
-              compilation_progress_[slot_index], code->tier());
+          // Update function's recompilation progress.
+          compilation_progress_[slot_index] =
+              ReachedRecompilationTierField::update(
+                  compilation_progress_[slot_index], code->tier());
           if (outstanding_recompilation_functions_ == 0) {
-            completes_recompilation = true;
+            triggered_events.Add(CompilationEvent::kFinishedRecompilation);
           }
         }
-      } else {
-        // Update function's compilation progress.
-        if (code->tier() > reached_tier) {
-          compilation_progress_[slot_index] = ReachedTierField::update(
-              compilation_progress_[slot_index], code->tier());
-        }
+      }
+
+      // Update function's compilation progress.
+      if (code->tier() > reached_tier) {
+        compilation_progress_[slot_index] = ReachedTierField::update(
+            compilation_progress_[slot_index], code->tier());
       }
       DCHECK_LE(0, outstanding_baseline_units_);
     }
   }
 
-  TriggerCallbacks(completes_baseline_compilation,
-                   completes_top_tier_compilation, completes_recompilation);
+  TriggerCallbacks(triggered_events);
 }
 
 void CompilationStateImpl::OnFinishedJSToWasmWrapperUnits(int num) {
   if (num == 0) return;
   base::MutexGuard guard(&callbacks_mutex_);
+  DCHECK_GE(outstanding_baseline_units_, num);
   outstanding_baseline_units_ -= num;
-  bool completes_baseline_compilation = outstanding_baseline_units_ == 0;
-  TriggerCallbacks(completes_baseline_compilation, false);
+  TriggerCallbacks();
 }
 
-void CompilationStateImpl::TriggerCallbacks(bool completes_baseline_compilation,
-                                            bool completes_top_tier_compilation,
-                                            bool completes_recompilation) {
-  if (completes_recompilation) {
-    for (auto& callback : callbacks_) {
-      callback(CompilationEvent::kFinishedRecompilation);
-    }
-  }
-  if (completes_baseline_compilation) {
-    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), "BaselineFinished");
-    for (auto& callback : callbacks_) {
-      callback(CompilationEvent::kFinishedBaselineCompilation);
-    }
+void CompilationStateImpl::TriggerCallbacks(
+    base::EnumSet<CompilationEvent> triggered_events) {
+  DCHECK(!callbacks_mutex_.TryLock());
+
+  if (outstanding_baseline_units_ == 0) {
+    triggered_events.Add(CompilationEvent::kFinishedBaselineCompilation);
     if (outstanding_top_tier_functions_ == 0) {
-      completes_top_tier_compilation = true;
+      triggered_events.Add(CompilationEvent::kFinishedTopTierCompilation);
     }
   }
-  if (outstanding_baseline_units_ == 0 && completes_top_tier_compilation) {
-    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), "TopTierFinished");
+
+  if (triggered_events.empty()) return;
+
+  // Don't trigger past events again.
+  triggered_events -= finished_events_;
+  // Recompilation can happen multiple times, thus do not store this.
+  finished_events_ |=
+      triggered_events - CompilationEvent::kFinishedRecompilation;
+
+  for (auto event :
+       {std::make_pair(CompilationEvent::kFinishedBaselineCompilation,
+                       "BaselineFinished"),
+        std::make_pair(CompilationEvent::kFinishedTopTierCompilation,
+                       "TopTierFinished"),
+        std::make_pair(CompilationEvent::kFinishedRecompilation,
+                       "RecompilationFinished")}) {
+    if (!triggered_events.contains(event.first)) continue;
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.wasm"), event.second);
     for (auto& callback : callbacks_) {
-      callback(CompilationEvent::kFinishedTopTierCompilation);
+      callback(event.first);
     }
   }
+
   if (outstanding_baseline_units_ == 0 &&
       outstanding_top_tier_functions_ == 0 &&
       outstanding_recompilation_functions_ == 0) {
@@ -2828,7 +2961,7 @@ void CompileJsToWasmWrappers(Isolate* isolate, const WasmModule* module,
 
 WasmCode* CompileImportWrapper(
     WasmEngine* wasm_engine, NativeModule* native_module, Counters* counters,
-    compiler::WasmImportCallKind kind, FunctionSig* sig,
+    compiler::WasmImportCallKind kind, const FunctionSig* sig,
     WasmImportWrapperCache::ModificationScope* cache_scope) {
   // Entry should exist, so that we don't insert a new one and invalidate
   // other threads' iterators/references, but it should not have been compiled
@@ -2843,8 +2976,9 @@ WasmCode* CompileImportWrapper(
       wasm_engine, &env, kind, sig, source_positions);
   std::unique_ptr<WasmCode> wasm_code = native_module->AddCode(
       result.func_index, result.code_desc, result.frame_slot_count,
-      result.tagged_parameter_slots, std::move(result.protected_instructions),
-      std::move(result.source_positions), GetCodeKind(result),
+      result.tagged_parameter_slots,
+      result.protected_instructions_data.as_vector(),
+      result.source_positions.as_vector(), GetCodeKind(result),
       ExecutionTier::kNone);
   WasmCode* published_code = native_module->PublishCode(std::move(wasm_code));
   (*cache_scope)[key] = published_code;
@@ -2856,7 +2990,7 @@ WasmCode* CompileImportWrapper(
 }
 
 Handle<Script> CreateWasmScript(Isolate* isolate,
-                                const ModuleWireBytes& wire_bytes,
+                                Vector<const uint8_t> wire_bytes,
                                 Vector<const char> source_map_url,
                                 WireBytesRef name,
                                 Vector<const char> source_url) {
@@ -2867,8 +3001,8 @@ Handle<Script> CreateWasmScript(Isolate* isolate,
   script->set_type(Script::TYPE_WASM);
 
   int hash = StringHasher::HashSequentialString(
-      reinterpret_cast<const char*>(wire_bytes.start()),
-      static_cast<int>(wire_bytes.length()), kZeroHashSeed);
+      reinterpret_cast<const char*>(wire_bytes.begin()), wire_bytes.length(),
+      kZeroHashSeed);
 
   const int kBufferSize = 32;
   char buffer[kBufferSize];
@@ -2887,7 +3021,7 @@ Handle<Script> CreateWasmScript(Isolate* isolate,
             .ToHandleChecked();
     Handle<String> module_name =
         WasmModuleObject::ExtractUtf8StringFromModuleBytes(
-            isolate, wire_bytes.module_bytes(), name, kNoInternalize);
+            isolate, wire_bytes, name, kNoInternalize);
     name_str = isolate->factory()
                    ->NewConsString(module_name, name_hash)
                    .ToHandleChecked();
diff --git a/deps/v8/src/wasm/module-compiler.h b/deps/v8/src/wasm/module-compiler.h
index b60c12702f..4c6acd9aa9 100644
--- a/deps/v8/src/wasm/module-compiler.h
+++ b/deps/v8/src/wasm/module-compiler.h
@@ -57,11 +57,11 @@ void CompileJsToWasmWrappers(Isolate* isolate, const WasmModule* module,
 V8_EXPORT_PRIVATE
 WasmCode* CompileImportWrapper(
     WasmEngine* wasm_engine, NativeModule* native_module, Counters* counters,
-    compiler::WasmImportCallKind kind, FunctionSig* sig,
+    compiler::WasmImportCallKind kind, const FunctionSig* sig,
     WasmImportWrapperCache::ModificationScope* cache_scope);
 
 V8_EXPORT_PRIVATE Handle<Script> CreateWasmScript(
-    Isolate* isolate, const ModuleWireBytes& wire_bytes,
+    Isolate* isolate, Vector<const uint8_t> wire_bytes,
     Vector<const char> source_map_url, WireBytesRef name,
     Vector<const char> source_url = {});
 
@@ -149,9 +149,12 @@ class AsyncCompileJob {
 
   void CreateNativeModule(std::shared_ptr<const WasmModule> module,
                           size_t code_size_estimate);
+  // Return true for cache hit, false for cache miss.
+  bool GetOrCreateNativeModule(std::shared_ptr<const WasmModule> module,
+                               size_t code_size_estimate);
   void PrepareRuntimeObjects();
 
-  void FinishCompile();
+  void FinishCompile(bool is_after_cache_hit);
 
   void DecodeFailed(const WasmError&);
   void AsyncCompileFailed();
diff --git a/deps/v8/src/wasm/module-decoder.cc b/deps/v8/src/wasm/module-decoder.cc
index bc8260cd9b..58be26f845 100644
--- a/deps/v8/src/wasm/module-decoder.cc
+++ b/deps/v8/src/wasm/module-decoder.cc
@@ -149,6 +149,42 @@ WireBytesRef consume_string(Decoder* decoder, bool validate_utf8,
   return {offset, decoder->failed() ? 0 : length};
 }
 
+namespace {
+SectionCode IdentifyUnknownSectionInternal(Decoder* decoder) {
+  WireBytesRef string = consume_string(decoder, true, "section name");
+  if (decoder->failed()) {
+    return kUnknownSectionCode;
+  }
+  const byte* section_name_start =
+      decoder->start() + decoder->GetBufferRelativeOffset(string.offset());
+
+  TRACE("  +%d  section name        : \"%.*s\"\n",
+        static_cast<int>(section_name_start - decoder->start()),
+        string.length() < 20 ? string.length() : 20, section_name_start);
+
+  if (string.length() == num_chars(kNameString) &&
+      strncmp(reinterpret_cast<const char*>(section_name_start), kNameString,
+              num_chars(kNameString)) == 0) {
+    return kNameSectionCode;
+  } else if (string.length() == num_chars(kSourceMappingURLString) &&
+             strncmp(reinterpret_cast<const char*>(section_name_start),
+                     kSourceMappingURLString,
+                     num_chars(kSourceMappingURLString)) == 0) {
+    return kSourceMappingURLSectionCode;
+  } else if (string.length() == num_chars(kCompilationHintsString) &&
+             strncmp(reinterpret_cast<const char*>(section_name_start),
+                     kCompilationHintsString,
+                     num_chars(kCompilationHintsString)) == 0) {
+    return kCompilationHintsSectionCode;
+  } else if (string.length() == num_chars(kDebugInfoString) &&
+             strncmp(reinterpret_cast<const char*>(section_name_start),
+                     kDebugInfoString, num_chars(kDebugInfoString)) == 0) {
+    return kDebugInfoSectionCode;
+  }
+  return kUnknownSectionCode;
+}
+}  // namespace
+
 // An iterator over the sections in a wasm binary module.
 // Automatically skips all unknown sections.
 class WasmSectionIterator {
@@ -232,8 +268,13 @@ class WasmSectionIterator {
     if (section_code == kUnknownSectionCode) {
       // Check for the known "name", "sourceMappingURL", or "compilationHints"
       // section.
-      section_code =
-          ModuleDecoder::IdentifyUnknownSection(decoder_, section_end_);
+      // To identify the unknown section we set the end of the decoder bytes to
+      // the end of the custom section, so that we do not read the section name
+      // beyond the end of the section.
+      const byte* module_end = decoder_->end();
+      decoder_->set_end(section_end_);
+      section_code = IdentifyUnknownSectionInternal(decoder_);
+      if (decoder_->ok()) decoder_->set_end(module_end);
       // As a side effect, the above function will forward the decoder to after
       // the identifier string.
       payload_start_ = decoder_->pc();
@@ -272,6 +313,8 @@ class ModuleDecoderImpl : public Decoder {
       error(start_, "end is less than start");
       end_ = start_;
     }
+    module_start_ = module_start;
+    module_end_ = module_end;
   }
 
   void onFirstError() override {
@@ -367,6 +410,7 @@ class ModuleDecoderImpl : public Decoder {
 
   void DecodeSection(SectionCode section_code, Vector<const uint8_t> bytes,
                      uint32_t offset, bool verify_functions = true) {
+    VerifyFunctionDeclarations(section_code);
     if (failed()) return;
     Reset(bytes, offset);
     TRACE("Section: %s\n", SectionName(section_code));
@@ -390,8 +434,8 @@ class ModuleDecoderImpl : public Decoder {
         break;
       case kExceptionSectionCode:
         if (!CheckUnorderedSection(section_code)) return;
-        if (!CheckSectionOrder(section_code, kGlobalSectionCode,
-                               kExportSectionCode))
+        if (!CheckSectionOrder(section_code, kMemorySectionCode,
+                               kGlobalSectionCode))
           return;
         break;
       case kNameSectionCode:
@@ -510,7 +554,7 @@ class ModuleDecoderImpl : public Decoder {
     for (uint32_t i = 0; ok() && i < signatures_count; ++i) {
       TRACE("DecodeSignature[%d] module+%d\n", i,
             static_cast<int>(pc_ - start_));
-      FunctionSig* s = consume_sig(module_->signature_zone.get());
+      const FunctionSig* s = consume_sig(module_->signature_zone.get());
       module_->signatures.push_back(s);
       uint32_t id = s ? module_->signature_map.FindOrInsert(*s) : 0;
       module_->signature_ids.push_back(id);
@@ -548,7 +592,8 @@ class ModuleDecoderImpl : public Decoder {
                                         0,              // sig_index
                                         {0, 0},         // code
                                         true,           // imported
-                                        false});        // exported
+                                        false,          // exported
+                                        false});        // declared
           WasmFunction* function = &module_->functions.back();
           function->sig_index =
               consume_sig_index(module_.get(), &function->sig);
@@ -582,9 +627,9 @@ class ModuleDecoderImpl : public Decoder {
           if (!AddMemory(module_.get())) break;
           uint8_t flags = validate_memory_flags(&module_->has_shared_memory);
           consume_resizable_limits(
-              "memory", "pages", kSpecMaxWasmMemoryPages,
+              "memory", "pages", max_initial_mem_pages(),
               &module_->initial_pages, &module_->has_maximum_pages,
-              kSpecMaxWasmMemoryPages, &module_->maximum_pages, flags);
+              max_maximum_mem_pages(), &module_->maximum_pages, flags);
           break;
         }
         case kExternalGlobal: {
@@ -607,7 +652,7 @@ class ModuleDecoderImpl : public Decoder {
             break;
           }
           import->index = static_cast<uint32_t>(module_->exceptions.size());
-          WasmExceptionSig* exception_sig = nullptr;
+          const WasmExceptionSig* exception_sig = nullptr;
           consume_exception_attribute();  // Attribute ignored for now.
           consume_exception_sig_index(module_.get(), &exception_sig);
           module_->exceptions.emplace_back(exception_sig);
@@ -638,7 +683,8 @@ class ModuleDecoderImpl : public Decoder {
                                     0,           // sig_index
                                     {0, 0},      // code
                                     false,       // imported
-                                    false});     // exported
+                                    false,       // exported
+                                    false});     // declared
       WasmFunction* function = &module_->functions.back();
       function->sig_index = consume_sig_index(module_.get(), &function->sig);
       if (!ok()) return;
@@ -673,8 +719,8 @@ class ModuleDecoderImpl : public Decoder {
       if (!AddMemory(module_.get())) break;
       uint8_t flags = validate_memory_flags(&module_->has_shared_memory);
       consume_resizable_limits(
-          "memory", "pages", kSpecMaxWasmMemoryPages, &module_->initial_pages,
-          &module_->has_maximum_pages, kSpecMaxWasmMemoryPages,
+          "memory", "pages", max_initial_mem_pages(), &module_->initial_pages,
+          &module_->has_maximum_pages, max_maximum_mem_pages(),
           &module_->maximum_pages, flags);
     }
   }
@@ -806,43 +852,43 @@ class ModuleDecoderImpl : public Decoder {
     uint32_t element_count =
         consume_count("element count", FLAG_wasm_max_table_size);
 
-    if (element_count > 0 && module_->tables.size() == 0) {
-      error(pc_, "The element section requires a table");
-    }
     for (uint32_t i = 0; ok() && i < element_count; ++i) {
       const byte* pos = pc();
 
-      bool is_active;
+      WasmElemSegment::Status status;
       bool functions_as_elements;
       uint32_t table_index;
       WasmInitExpr offset;
-      consume_element_segment_header(&is_active, &functions_as_elements,
+      ValueType type = kWasmBottom;
+      consume_element_segment_header(&status, &functions_as_elements, &type,
                                      &table_index, &offset);
       if (failed()) return;
+      DCHECK_NE(type, kWasmBottom);
 
-      if (is_active) {
+      if (status == WasmElemSegment::kStatusActive) {
         if (table_index >= module_->tables.size()) {
           errorf(pos, "out of bounds table index %u", table_index);
           break;
         }
-        if (!ValueTypes::IsSubType(kWasmFuncRef,
-                                   module_->tables[table_index].type)) {
+        if (!type.IsSubTypeOf(module_->tables[table_index].type)) {
           errorf(pos,
-                 "Invalid element segment. Table %u is not of type FuncRef",
-                 table_index);
+                 "Invalid element segment. Table %u is not a super-type of %s",
+                 table_index, type.type_name());
           break;
         }
       }
 
       uint32_t num_elem =
           consume_count("number of elements", max_table_init_entries());
-      if (is_active) {
+      if (status == WasmElemSegment::kStatusActive) {
         module_->elem_segments.emplace_back(table_index, offset);
       } else {
-        module_->elem_segments.emplace_back();
+        module_->elem_segments.emplace_back(
+            status == WasmElemSegment::kStatusDeclarative);
       }
 
       WasmElemSegment* init = &module_->elem_segments.back();
+      init->type = type;
       for (uint32_t j = 0; j < num_elem; j++) {
         uint32_t index = functions_as_elements ? consume_element_expr()
                                                : consume_element_func_index();
@@ -869,6 +915,8 @@ class ModuleDecoderImpl : public Decoder {
       if (failed()) break;
       DecodeFunctionBody(i, size, offset, verify_functions);
     }
+    DCHECK_GE(pc_offset(), pos);
+    set_code_section(pos, pc_offset() - pos);
   }
 
   bool CheckFunctionsCount(uint32_t functions_count, uint32_t offset) {
@@ -887,7 +935,7 @@ class ModuleDecoderImpl : public Decoder {
         &module_->functions[index + module_->num_imported_functions];
     function->code = {offset, length};
     if (verify_functions) {
-      ModuleWireBytes bytes(start_, end_);
+      ModuleWireBytes bytes(module_start_, module_end_);
       VerifyFunctionBody(module_->signature_zone->allocator(),
                          index + module_->num_imported_functions, bytes,
                          module_.get(), function);
@@ -912,10 +960,6 @@ class ModuleDecoderImpl : public Decoder {
     module_->data_segments.reserve(data_segments_count);
     for (uint32_t i = 0; ok() && i < data_segments_count; ++i) {
       const byte* pos = pc();
-      if (!module_->has_memory) {
-        error("cannot load data without memory");
-        break;
-      }
       TRACE("DecodeDataSegment[%d] module+%d\n", i,
             static_cast<int>(pc_ - start_));
 
@@ -925,9 +969,15 @@ class ModuleDecoderImpl : public Decoder {
       consume_data_segment_header(&is_active, &memory_index, &dest_addr);
       if (failed()) break;
 
-      if (is_active && memory_index != 0) {
-        errorf(pos, "illegal memory index %u != 0", memory_index);
-        break;
+      if (is_active) {
+        if (!module_->has_memory) {
+          error("cannot load data without memory");
+          break;
+        }
+        if (memory_index != 0) {
+          errorf(pos, "illegal memory index %u != 0", memory_index);
+          break;
+        }
       }
 
       uint32_t source_length = consume_u32v("source size");
@@ -1084,7 +1134,7 @@ class ModuleDecoderImpl : public Decoder {
     for (uint32_t i = 0; ok() && i < exception_count; ++i) {
       TRACE("DecodeException[%d] module+%d\n", i,
             static_cast<int>(pc_ - start_));
-      WasmExceptionSig* exception_sig = nullptr;
+      const WasmExceptionSig* exception_sig = nullptr;
       consume_exception_attribute();  // Attribute ignored for now.
       consume_exception_sig_index(module_.get(), &exception_sig);
       module_->exceptions.emplace_back(exception_sig);
@@ -1114,7 +1164,41 @@ class ModuleDecoderImpl : public Decoder {
     return true;
   }
 
+  void VerifyFunctionDeclarations(SectionCode section_code) {
+    // Since we will only know if a function was properly declared after all the
+    // element sections have been parsed, but we need to verify the proper use
+    // within global initialization, we are deferring those checks.
+    if (deferred_funcref_error_offsets_.empty()) {
+      // No verifications to do be done.
+      return;
+    }
+    if (!ok()) {
+      // Previous errors exist.
+      return;
+    }
+    // TODO(ecmziegler): Adjust logic if module order changes (e.g. event
+    // section).
+    if (section_code <= kElementSectionCode &&
+        section_code != kUnknownSectionCode) {
+      // Before the element section and not at end of decoding.
+      return;
+    }
+    for (auto& func_offset : deferred_funcref_error_offsets_) {
+      DCHECK_LT(func_offset.first, module_->functions.size());
+      if (!module_->functions[func_offset.first].declared) {
+        errorf(func_offset.second, "undeclared reference to function #%u",
+               func_offset.first);
+        break;
+      }
+    }
+    deferred_funcref_error_offsets_.clear();
+  }
+
   ModuleResult FinishDecoding(bool verify_functions = true) {
+    // Ensure that function verifications were done even if no section followed
+    // the global section.
+    VerifyFunctionDeclarations(kUnknownSectionCode);
+
     if (ok() && CheckMismatchedCounts()) {
       CalculateGlobalOffsets(module_.get());
     }
@@ -1126,6 +1210,10 @@ class ModuleDecoderImpl : public Decoder {
     return result;
   }
 
+  void set_code_section(uint32_t offset, uint32_t size) {
+    module_->code = {offset, size};
+  }
+
   // Decodes an entire module.
   ModuleResult DecodeModule(Counters* counters, AccountingAllocator* allocator,
                             bool verify_functions = true) {
@@ -1184,9 +1272,9 @@ class ModuleDecoderImpl : public Decoder {
   }
 
   // Decodes a single function signature at {start}.
-  FunctionSig* DecodeFunctionSignature(Zone* zone, const byte* start) {
+  const FunctionSig* DecodeFunctionSignature(Zone* zone, const byte* start) {
     pc_ = start;
-    FunctionSig* result = consume_sig(zone);
+    const FunctionSig* result = consume_sig(zone);
     return ok() ? result : nullptr;
   }
 
@@ -1210,6 +1298,8 @@ class ModuleDecoderImpl : public Decoder {
  private:
   const WasmFeatures enabled_features_;
   std::shared_ptr<WasmModule> module_;
+  const byte* module_start_;
+  const byte* module_end_;
   Counters* counters_ = nullptr;
   // The type section is the first section in a module.
   uint8_t next_ordered_section_ = kFirstSectionInModule;
@@ -1225,6 +1315,10 @@ class ModuleDecoderImpl : public Decoder {
                     kLastKnownModuleSection,
                 "not enough bits");
   WasmError intermediate_error_;
+  // Map from function index to wire byte offset of first funcref initialization
+  // in global section. Used for deferred checking and proper error reporting if
+  // these were not properly declared in the element section.
+  std::unordered_map<uint32_t, int> deferred_funcref_error_offsets_;
   ModuleOrigin origin_;
 
   bool has_seen_unordered_section(SectionCode section_code) {
@@ -1277,14 +1371,14 @@ class ModuleDecoderImpl : public Decoder {
         errorf(pos,
                "type mismatch in global initialization "
                "(from global #%u), expected %s, got %s",
-               other_index, ValueTypes::TypeName(global->type),
-               ValueTypes::TypeName(module->globals[other_index].type));
+               other_index, global->type.type_name(),
+               module->globals[other_index].type.type_name());
       }
     } else {
-      if (!ValueTypes::IsSubType(TypeOf(module, global->init), global->type)) {
+      if (!TypeOf(module, global->init).IsSubTypeOf(global->type)) {
         errorf(pos, "type error in global initialization, expected %s, got %s",
-               ValueTypes::TypeName(global->type),
-               ValueTypes::TypeName(TypeOf(module, global->init)));
+               global->type.type_name(),
+               TypeOf(module, global->init).type_name());
       }
     }
   }
@@ -1297,13 +1391,12 @@ class ModuleDecoderImpl : public Decoder {
     for (WasmGlobal& global : module->globals) {
       if (global.mutability && global.imported) {
         global.index = num_imported_mutable_globals++;
-      } else if (ValueTypes::IsReferenceType(global.type)) {
+      } else if (global.type.IsReferenceType()) {
         global.offset = tagged_offset;
         // All entries in the tagged_globals_buffer have size 1.
         tagged_offset++;
       } else {
-        byte size =
-            ValueTypes::MemSize(ValueTypes::MachineTypeFor(global.type));
+        int size = global.type.element_size_bytes();
         untagged_offset = (untagged_offset + size - 1) & ~(size - 1);  // align
         global.offset = untagged_offset;
         untagged_offset += size;
@@ -1327,16 +1420,9 @@ class ModuleDecoderImpl : public Decoder {
         start_ + GetBufferRelativeOffset(function->code.offset()),
         start_ + GetBufferRelativeOffset(function->code.end_offset())};
 
-    DecodeResult result;
-    {
-      auto time_counter = SELECT_WASM_COUNTER(GetCounters(), origin_,
-                                              wasm_decode, function_time);
-
-      TimedHistogramScope wasm_decode_function_time_scope(time_counter);
-      WasmFeatures unused_detected_features = WasmFeatures::None();
-      result = VerifyWasmCode(allocator, enabled_features_, module,
-                              &unused_detected_features, body);
-    }
+    WasmFeatures unused_detected_features = WasmFeatures::None();
+    DecodeResult result = VerifyWasmCode(allocator, enabled_features_, module,
+                                         &unused_detected_features, body);
 
     // If the decode failed and this is the first error, set error code and
     // location.
@@ -1349,7 +1435,7 @@ class ModuleDecoderImpl : public Decoder {
     }
   }
 
-  uint32_t consume_sig_index(WasmModule* module, FunctionSig** sig) {
+  uint32_t consume_sig_index(WasmModule* module, const FunctionSig** sig) {
     const byte* pos = pc_;
     uint32_t sig_index = consume_u32v("signature index");
     if (sig_index >= module->signatures.size()) {
@@ -1362,7 +1448,8 @@ class ModuleDecoderImpl : public Decoder {
     return sig_index;
   }
 
-  uint32_t consume_exception_sig_index(WasmModule* module, FunctionSig** sig) {
+  uint32_t consume_exception_sig_index(WasmModule* module,
+                                       const FunctionSig** sig) {
     const byte* pos = pc_;
     uint32_t sig_index = consume_sig_index(module, sig);
     if (*sig && (*sig)->return_count() != 0) {
@@ -1560,6 +1647,8 @@ class ModuleDecoderImpl : public Decoder {
             errorf(pc() - 1, "invalid function index: %u", imm.index);
             break;
           }
+          // Defer check for declaration of function reference.
+          deferred_funcref_error_offsets_.emplace(imm.index, pc_offset());
           expr.kind = WasmInitExpr::kRefFuncConst;
           expr.val.function_index = imm.index;
           len = imm.length;
@@ -1579,8 +1668,7 @@ class ModuleDecoderImpl : public Decoder {
     }
     if (expected != kWasmStmt && TypeOf(module, expr) != kWasmI32) {
       errorf(pos, "type error in init expression, expected %s, got %s",
-             ValueTypes::TypeName(expected),
-             ValueTypes::TypeName(TypeOf(module, expr)));
+             expected.type_name(), TypeOf(module, expr).type_name());
     }
     return expr;
   }
@@ -1665,7 +1753,7 @@ class ModuleDecoderImpl : public Decoder {
     return kWasmStmt;
   }
 
-  FunctionSig* consume_sig(Zone* zone) {
+  const FunctionSig* consume_sig(Zone* zone) {
     if (!expect_u8("type form", kWasmFunctionTypeCode)) return nullptr;
     // parse parameter types
     uint32_t param_count =
@@ -1710,9 +1798,9 @@ class ModuleDecoderImpl : public Decoder {
     return attribute;
   }
 
-  void consume_element_segment_header(bool* is_active,
+  void consume_element_segment_header(WasmElemSegment::Status* status,
                                       bool* functions_as_elements,
-                                      uint32_t* table_index,
+                                      ValueType* type, uint32_t* table_index,
                                       WasmInitExpr* offset) {
     const byte* pos = pc();
     uint8_t flag;
@@ -1743,11 +1831,28 @@ class ModuleDecoderImpl : public Decoder {
         kIsPassiveMask | kHasTableIndexMask | kFunctionsAsElementsMask;
 
     bool is_passive = flag & kIsPassiveMask;
-    *is_active = !is_passive;
+    if (!is_passive) {
+      *status = WasmElemSegment::kStatusActive;
+      if (module_->tables.size() == 0) {
+        error(pc_, "Active element sections require a table");
+      }
+    } else if ((flag & kHasTableIndexMask)) {  // Special bit combination for
+                                               // declarative segments.
+      *status = WasmElemSegment::kStatusDeclarative;
+    } else {
+      *status = WasmElemSegment::kStatusPassive;
+    }
     *functions_as_elements = flag & kFunctionsAsElementsMask;
-    bool has_table_index = flag & kHasTableIndexMask;
+    bool has_table_index = (flag & kHasTableIndexMask) &&
+                           *status == WasmElemSegment::kStatusActive;
 
-    if (is_passive && !enabled_features_.has_bulk_memory()) {
+    if (*status == WasmElemSegment::kStatusDeclarative &&
+        !enabled_features_.has_anyref()) {
+      error("Declarative element segments require --experimental-wasm-anyref");
+      return;
+    }
+    if (*status == WasmElemSegment::kStatusPassive &&
+        !enabled_features_.has_bulk_memory()) {
       error("Passive element segments require --experimental-wasm-bulk-memory");
       return;
     }
@@ -1764,8 +1869,8 @@ class ModuleDecoderImpl : public Decoder {
           "--experimental-wasm-bulk-memory or --experimental-wasm-anyref?");
       return;
     }
-    if ((flag & kFullMask) != flag || (!(*is_active) && has_table_index)) {
-      errorf(pos, "illegal flag value %u. Must be 0, 1, 2, 4, 5 or 6", flag);
+    if ((flag & kFullMask) != flag) {
+      errorf(pos, "illegal flag value %u. Must be between 0 and 7", flag);
     }
 
     if (has_table_index) {
@@ -1774,25 +1879,20 @@ class ModuleDecoderImpl : public Decoder {
       *table_index = 0;
     }
 
-    if (*is_active) {
+    if (*status == WasmElemSegment::kStatusActive) {
       *offset = consume_init_expr(module_.get(), kWasmI32);
     }
 
-    if (*is_active && !has_table_index) {
+    if (*status == WasmElemSegment::kStatusActive && !has_table_index) {
       // Active segments without table indices are a special case for backwards
       // compatibility. These cases have an implicit element kind or element
       // type, so we are done already with the segment header.
+      *type = kWasmFuncRef;
       return;
     }
 
     if (*functions_as_elements) {
-      // We have to check that there is an element type of type FuncRef. All
-      // other element types are not valid yet.
-      ValueType type = consume_reference_type();
-      if (!ValueTypes::IsSubType(kWasmFuncRef, type)) {
-        error(pc_ - 1, "invalid element segment type");
-        return;
-      }
+      *type = consume_reference_type();
     } else {
       // We have to check that there is an element kind of type Function. All
       // other element kinds are not valid yet.
@@ -1802,6 +1902,7 @@ class ModuleDecoderImpl : public Decoder {
         errorf(pos, "illegal element kind %x. Must be 0x00", val);
         return;
       }
+      *type = kWasmFuncRef;
     }
   }
 
@@ -1853,6 +1954,7 @@ class ModuleDecoderImpl : public Decoder {
     uint32_t index =
         consume_func_index(module_.get(), &func, "element function index");
     if (failed()) return index;
+    func->declared = true;
     DCHECK_NE(func, nullptr);
     DCHECK_EQ(index, func->func_index);
     DCHECK_NE(index, WasmElemSegment::kNullIndex);
@@ -1885,9 +1987,6 @@ ModuleResult DecodeWasmModule(const WasmFeatures& enabled,
                               bool verify_functions, ModuleOrigin origin,
                               Counters* counters,
                               AccountingAllocator* allocator) {
-  auto counter =
-      SELECT_WASM_COUNTER(counters, origin, wasm_decode, module_time);
-  TimedHistogramScope wasm_decode_module_time_scope(counter);
   size_t size = module_end - module_start;
   CHECK_LE(module_start, module_end);
   if (size >= kV8MaxWasmModuleSize) {
@@ -1901,19 +2000,7 @@ ModuleResult DecodeWasmModule(const WasmFeatures& enabled,
   // Signatures are stored in zone memory, which have the same lifetime
   // as the {module}.
   ModuleDecoderImpl decoder(enabled, module_start, module_end, origin);
-  ModuleResult result =
-      decoder.DecodeModule(counters, allocator, verify_functions);
-  // TODO(bradnelson): Improve histogram handling of size_t.
-  // TODO(titzer): this isn't accurate, since it doesn't count the data
-  // allocated on the C++ heap.
-  // https://bugs.chromium.org/p/chromium/issues/detail?id=657320
-  if (result.ok()) {
-    auto peak_counter = SELECT_WASM_COUNTER(counters, origin, wasm_decode,
-                                            module_peak_memory_bytes);
-    peak_counter->AddSample(
-        static_cast<int>(result.value()->signature_zone->allocation_size()));
-  }
-  return result;
+  return decoder.DecodeModule(counters, allocator, verify_functions);
 }
 
 ModuleDecoder::ModuleDecoder(const WasmFeatures& enabled)
@@ -1958,46 +2045,25 @@ ModuleResult ModuleDecoder::FinishDecoding(bool verify_functions) {
   return impl_->FinishDecoding(verify_functions);
 }
 
-SectionCode ModuleDecoder::IdentifyUnknownSection(Decoder* decoder,
-                                                  const byte* end) {
-  WireBytesRef string = consume_string(decoder, true, "section name");
-  if (decoder->failed() || decoder->pc() > end) {
-    return kUnknownSectionCode;
-  }
-  const byte* section_name_start =
-      decoder->start() + decoder->GetBufferRelativeOffset(string.offset());
-
-  TRACE("  +%d  section name        : \"%.*s\"\n",
-        static_cast<int>(section_name_start - decoder->start()),
-        string.length() < 20 ? string.length() : 20, section_name_start);
+void ModuleDecoder::set_code_section(uint32_t offset, uint32_t size) {
+  return impl_->set_code_section(offset, size);
+}
 
-  if (string.length() == num_chars(kNameString) &&
-      strncmp(reinterpret_cast<const char*>(section_name_start), kNameString,
-              num_chars(kNameString)) == 0) {
-    return kNameSectionCode;
-  } else if (string.length() == num_chars(kSourceMappingURLString) &&
-             strncmp(reinterpret_cast<const char*>(section_name_start),
-                     kSourceMappingURLString,
-                     num_chars(kSourceMappingURLString)) == 0) {
-    return kSourceMappingURLSectionCode;
-  } else if (string.length() == num_chars(kCompilationHintsString) &&
-             strncmp(reinterpret_cast<const char*>(section_name_start),
-                     kCompilationHintsString,
-                     num_chars(kCompilationHintsString)) == 0) {
-    return kCompilationHintsSectionCode;
-  } else if (string.length() == num_chars(kDebugInfoString) &&
-             strncmp(reinterpret_cast<const char*>(section_name_start),
-                     kDebugInfoString, num_chars(kDebugInfoString)) == 0) {
-    return kDebugInfoSectionCode;
-  }
-  return kUnknownSectionCode;
+size_t ModuleDecoder::IdentifyUnknownSection(ModuleDecoder* decoder,
+                                             Vector<const uint8_t> bytes,
+                                             uint32_t offset,
+                                             SectionCode* result) {
+  if (!decoder->ok()) return 0;
+  decoder->impl_->Reset(bytes, offset);
+  *result = IdentifyUnknownSectionInternal(decoder->impl_.get());
+  return decoder->impl_->pc() - bytes.begin();
 }
 
 bool ModuleDecoder::ok() { return impl_->ok(); }
 
-FunctionSig* DecodeWasmSignatureForTesting(const WasmFeatures& enabled,
-                                           Zone* zone, const byte* start,
-                                           const byte* end) {
+const FunctionSig* DecodeWasmSignatureForTesting(const WasmFeatures& enabled,
+                                                 Zone* zone, const byte* start,
+                                                 const byte* end) {
   ModuleDecoderImpl decoder(enabled, start, end, kWasmOrigin);
   return decoder.DecodeFunctionSignature(zone, start);
 }
@@ -2143,36 +2209,79 @@ bool FindNameSection(Decoder* decoder) {
 }  // namespace
 
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names) {
+                         std::unordered_map<uint32_t, WireBytesRef>* names,
+                         const Vector<const WasmExport> export_table) {
   DCHECK_NOT_NULL(names);
   DCHECK(names->empty());
 
   Decoder decoder(module_start, module_end);
-  if (!FindNameSection(&decoder)) return;
+  if (FindNameSection(&decoder)) {
+    while (decoder.ok() && decoder.more()) {
+      uint8_t name_type = decoder.consume_u8("name type");
+      if (name_type & 0x80) break;  // no varuint7
 
-  while (decoder.ok() && decoder.more()) {
-    uint8_t name_type = decoder.consume_u8("name type");
-    if (name_type & 0x80) break;  // no varuint7
+      uint32_t name_payload_len = decoder.consume_u32v("name payload length");
+      if (!decoder.checkAvailable(name_payload_len)) break;
 
-    uint32_t name_payload_len = decoder.consume_u32v("name payload length");
-    if (!decoder.checkAvailable(name_payload_len)) break;
+      if (name_type != NameSectionKindCode::kFunction) {
+        decoder.consume_bytes(name_payload_len, "name subsection payload");
+        continue;
+      }
+      uint32_t functions_count = decoder.consume_u32v("functions count");
 
-    if (name_type != NameSectionKindCode::kFunction) {
-      decoder.consume_bytes(name_payload_len, "name subsection payload");
-      continue;
+      for (; decoder.ok() && functions_count > 0; --functions_count) {
+        uint32_t function_index = decoder.consume_u32v("function index");
+        WireBytesRef name = consume_string(&decoder, false, "function name");
+
+        // Be lenient with errors in the name section: Ignore non-UTF8 names.
+        // You can even assign to the same function multiple times (last valid
+        // one wins).
+        if (decoder.ok() && validate_utf8(&decoder, name)) {
+          names->insert(std::make_pair(function_index, name));
+        }
+      }
+    }
+  }
+
+  // Extract from export table.
+  for (const WasmExport& exp : export_table) {
+    switch (exp.kind) {
+      case kExternalFunction:
+        if (names->count(exp.index) == 0) {
+          names->insert(std::make_pair(exp.index, exp.name));
+        }
+        break;
+      default:
+        break;
     }
-    uint32_t functions_count = decoder.consume_u32v("functions count");
+  }
+}
+
+void DecodeGlobalNames(
+    const Vector<const WasmImport> import_table,
+    const Vector<const WasmExport> export_table,
+    std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>*
+        names) {
+  DCHECK_NOT_NULL(names);
+  DCHECK(names->empty());
 
-    for (; decoder.ok() && functions_count > 0; --functions_count) {
-      uint32_t function_index = decoder.consume_u32v("function index");
-      WireBytesRef name = consume_string(&decoder, false, "function name");
+  // Extract from import table.
+  for (const WasmImport& imp : import_table) {
+    if (imp.kind != kExternalGlobal) continue;
+    if (!imp.module_name.is_set() || !imp.field_name.is_set()) continue;
+    if (names->count(imp.index) == 0) {
+      names->insert(std::make_pair(
+          imp.index, std::make_pair(imp.module_name, imp.field_name)));
+    }
+  }
 
-      // Be lenient with errors in the name section: Ignore non-UTF8 names. You
-      // can even assign to the same function multiple times (last valid one
-      // wins).
-      if (decoder.ok() && validate_utf8(&decoder, name)) {
-        names->insert(std::make_pair(function_index, name));
-      }
+  // Extract from export table.
+  for (const WasmExport& exp : export_table) {
+    if (exp.kind != kExternalGlobal) continue;
+    if (!exp.name.is_set()) continue;
+    if (names->count(exp.index) == 0) {
+      names->insert(
+          std::make_pair(exp.index, std::make_pair(WireBytesRef(), exp.name)));
     }
   }
 }
diff --git a/deps/v8/src/wasm/module-decoder.h b/deps/v8/src/wasm/module-decoder.h
index da35c0c4f5..6feeebb41d 100644
--- a/deps/v8/src/wasm/module-decoder.h
+++ b/deps/v8/src/wasm/module-decoder.h
@@ -133,7 +133,7 @@ V8_EXPORT_PRIVATE ModuleResult DecodeWasmModule(
 
 // Exposed for testing. Decodes a single function signature, allocating it
 // in the given zone. Returns {nullptr} upon failure.
-V8_EXPORT_PRIVATE FunctionSig* DecodeWasmSignatureForTesting(
+V8_EXPORT_PRIVATE const FunctionSig* DecodeWasmSignatureForTesting(
     const WasmFeatures& enabled, Zone* zone, const byte* start,
     const byte* end);
 
@@ -160,11 +160,20 @@ V8_EXPORT_PRIVATE std::vector<CustomSectionOffset> DecodeCustomSections(
 // function.
 AsmJsOffsetsResult DecodeAsmJsOffsets(Vector<const uint8_t> encoded_offsets);
 
-// Decode the function names from the name section.
-// Returns the result as an unordered map. Only names with valid utf8 encoding
-// are stored and conflicts are resolved by choosing the last name read.
+// Decode the function names from the name section and also look at export
+// table. Returns the result as an unordered map. Only names with valid utf8
+// encoding are stored and conflicts are resolved by choosing the last name
+// read.
 void DecodeFunctionNames(const byte* module_start, const byte* module_end,
-                         std::unordered_map<uint32_t, WireBytesRef>* names);
+                         std::unordered_map<uint32_t, WireBytesRef>* names,
+                         const Vector<const WasmExport> export_table);
+
+// Decode the global names from import table and export table. Returns the
+// result as an unordered map.
+void DecodeGlobalNames(
+    const Vector<const WasmImport> import_table,
+    const Vector<const WasmExport> export_table,
+    std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>* names);
 
 // Decode the local names assignment from the name section.
 // The result will be empty if no name section is present. On encountering an
@@ -194,6 +203,8 @@ class ModuleDecoder {
 
   ModuleResult FinishDecoding(bool verify_functions = true);
 
+  void set_code_section(uint32_t offset, uint32_t size);
+
   const std::shared_ptr<WasmModule>& shared_module() const;
   WasmModule* module() const { return shared_module().get(); }
 
@@ -203,10 +214,10 @@ class ModuleDecoder {
   // SectionCode if the unknown section is known to decoder.
   // The decoder is expected to point after the section length and just before
   // the identifier string of the unknown section.
-  // If a SectionCode other than kUnknownSectionCode is returned, the decoder
-  // will point right after the identifier string. Otherwise, the position is
-  // undefined.
-  static SectionCode IdentifyUnknownSection(Decoder* decoder, const byte* end);
+  // The return value is the number of bytes that were consumed.
+  static size_t IdentifyUnknownSection(ModuleDecoder* decoder,
+                                       Vector<const uint8_t> bytes,
+                                       uint32_t offset, SectionCode* result);
 
  private:
   const WasmFeatures enabled_features_;
diff --git a/deps/v8/src/wasm/module-instantiate.cc b/deps/v8/src/wasm/module-instantiate.cc
index 6d40e9ed5e..08bd8ff871 100644
--- a/deps/v8/src/wasm/module-instantiate.cc
+++ b/deps/v8/src/wasm/module-instantiate.cc
@@ -482,7 +482,7 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     // Check that indirect function table segments are within bounds.
     //--------------------------------------------------------------------------
     for (const WasmElemSegment& elem_segment : module_->elem_segments) {
-      if (!elem_segment.active) continue;
+      if (elem_segment.status != WasmElemSegment::kStatusActive) continue;
       DCHECK_LT(elem_segment.table_index, table_count);
       uint32_t base = EvalUint32InitExpr(instance, elem_segment.offset);
       // Because of imported tables, {table_size} has to come from the table
@@ -669,11 +669,8 @@ void InstanceBuilder::LoadDataSegments(Handle<WasmInstanceObject> instance) {
       }
       // No need to copy empty segments.
       if (size == 0) continue;
-      Address dest_addr =
-          reinterpret_cast<Address>(instance->memory_start()) + dest_offset;
-      Address src_addr = reinterpret_cast<Address>(wire_bytes.begin()) +
-                         segment.source.offset();
-      memory_copy_wrapper(dest_addr, src_addr, size);
+      std::memcpy(instance->memory_start() + dest_offset,
+                  wire_bytes.begin() + segment.source.offset(), size);
     } else {
       DCHECK(segment.active);
       // Segments of size == 0 are just nops.
@@ -691,22 +688,22 @@ void InstanceBuilder::LoadDataSegments(Handle<WasmInstanceObject> instance) {
 void InstanceBuilder::WriteGlobalValue(const WasmGlobal& global, double num) {
   TRACE("init [globals_start=%p + %u] = %lf, type = %s\n",
         raw_buffer_ptr(untagged_globals_, 0), global.offset, num,
-        ValueTypes::TypeName(global.type));
-  switch (global.type) {
-    case kWasmI32:
+        global.type.type_name());
+  switch (global.type.kind()) {
+    case ValueType::kI32:
       WriteLittleEndianValue<int32_t>(GetRawGlobalPtr<int32_t>(global),
                                       DoubleToInt32(num));
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       // The Wasm-BigInt proposal currently says that i64 globals may
       // only be initialized with BigInts. See:
       // https://github.com/WebAssembly/JS-BigInt-integration/issues/12
       UNREACHABLE();
-    case kWasmF32:
+    case ValueType::kF32:
       WriteLittleEndianValue<float>(GetRawGlobalPtr<float>(global),
                                     DoubleToFloat32(num));
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       WriteLittleEndianValue<double>(GetRawGlobalPtr<double>(global), num);
       break;
     default:
@@ -717,7 +714,7 @@ void InstanceBuilder::WriteGlobalValue(const WasmGlobal& global, double num) {
 void InstanceBuilder::WriteGlobalValue(const WasmGlobal& global, int64_t num) {
   TRACE("init [globals_start=%p + %u] = %" PRId64 ", type = %s\n",
         raw_buffer_ptr(untagged_globals_, 0), global.offset, num,
-        ValueTypes::TypeName(global.type));
+        global.type.type_name());
   DCHECK_EQ(kWasmI64, global.type);
   WriteLittleEndianValue<int64_t>(GetRawGlobalPtr<int64_t>(global), num);
 }
@@ -726,44 +723,45 @@ void InstanceBuilder::WriteGlobalValue(const WasmGlobal& global,
                                        Handle<WasmGlobalObject> value) {
   TRACE("init [globals_start=%p + %u] = ", raw_buffer_ptr(untagged_globals_, 0),
         global.offset);
-  switch (global.type) {
-    case kWasmI32: {
+  switch (global.type.kind()) {
+    case ValueType::kI32: {
       int32_t num = value->GetI32();
       WriteLittleEndianValue<int32_t>(GetRawGlobalPtr<int32_t>(global), num);
       TRACE("%d", num);
       break;
     }
-    case kWasmI64: {
+    case ValueType::kI64: {
       int64_t num = value->GetI64();
       WriteLittleEndianValue<int64_t>(GetRawGlobalPtr<int64_t>(global), num);
       TRACE("%" PRId64, num);
       break;
     }
-    case kWasmF32: {
+    case ValueType::kF32: {
       float num = value->GetF32();
       WriteLittleEndianValue<float>(GetRawGlobalPtr<float>(global), num);
       TRACE("%f", num);
       break;
     }
-    case kWasmF64: {
+    case ValueType::kF64: {
       double num = value->GetF64();
       WriteLittleEndianValue<double>(GetRawGlobalPtr<double>(global), num);
       TRACE("%lf", num);
       break;
     }
-    case kWasmAnyRef:
-    case kWasmFuncRef:
-    case kWasmNullRef:
-    case kWasmExnRef: {
+    case ValueType::kAnyRef:
+    case ValueType::kFuncRef:
+    case ValueType::kNullRef:
+    case ValueType::kExnRef: {
       DCHECK_IMPLIES(global.type == kWasmNullRef, value->GetRef()->IsNull());
       tagged_globals_->set(global.offset, *value->GetRef());
       break;
     }
-    default:
+    case ValueType::kStmt:
+    case ValueType::kS128:
+    case ValueType::kBottom:
       UNREACHABLE();
   }
-  TRACE(", type = %s (from WebAssembly.Global)\n",
-        ValueTypes::TypeName(global.type));
+  TRACE(", type = %s (from WebAssembly.Global)\n", global.type.type_name());
 }
 
 void InstanceBuilder::WriteGlobalAnyRef(const WasmGlobal& global,
@@ -835,7 +833,7 @@ bool InstanceBuilder::ProcessImportedFunction(
         Handle<WasmExternalFunction>::cast(value));
   }
   auto js_receiver = Handle<JSReceiver>::cast(value);
-  FunctionSig* expected_sig = module_->functions[func_index].sig;
+  const FunctionSig* expected_sig = module_->functions[func_index].sig;
   auto resolved =
       compiler::ResolveWasmImportCall(js_receiver, expected_sig, enabled_);
   compiler::WasmImportCallKind kind = resolved.first;
@@ -846,7 +844,7 @@ bool InstanceBuilder::ProcessImportedFunction(
                       import_index, module_name, import_name);
       return false;
     case compiler::WasmImportCallKind::kWasmToWasm: {
-      // The imported function is a WASM function from another instance.
+      // The imported function is a Wasm function from another instance.
       auto imported_function = Handle<WasmExportedFunction>::cast(js_receiver);
       Handle<WasmInstanceObject> imported_instance(
           imported_function->instance(), isolate_);
@@ -929,10 +927,10 @@ bool InstanceBuilder::InitializeImportedIndirectFunctionTable(
 
     Handle<WasmInstanceObject> target_instance =
         maybe_target_instance.ToHandleChecked();
-    FunctionSig* sig = target_instance->module_object()
-                           .module()
-                           ->functions[function_index]
-                           .sig;
+    const FunctionSig* sig = target_instance->module_object()
+                                 .module()
+                                 ->functions[function_index]
+                                 .sig;
 
     // Look up the signature's canonical id. If there is no canonical
     // id, then the signature does not appear at all in this module,
@@ -1065,7 +1063,7 @@ bool InstanceBuilder::ProcessImportedWasmGlobalObject(
     return false;
   }
 
-  bool is_sub_type = ValueTypes::IsSubType(global_object->type(), global.type);
+  bool is_sub_type = global_object->type().IsSubTypeOf(global.type);
   bool is_same_type = global_object->type() == global.type;
   bool valid_type = global.mutability ? is_same_type : is_sub_type;
 
@@ -1078,7 +1076,7 @@ bool InstanceBuilder::ProcessImportedWasmGlobalObject(
     DCHECK_LT(global.index, module_->num_imported_mutable_globals);
     Handle<Object> buffer;
     Address address_or_offset;
-    if (ValueTypes::IsReferenceType(global.type)) {
+    if (global.type.IsReferenceType()) {
       static_assert(sizeof(global_object->offset()) <= sizeof(Address),
                     "The offset into the globals buffer does not fit into "
                     "the imported_mutable_globals array");
@@ -1156,8 +1154,8 @@ bool InstanceBuilder::ProcessImportedGlobal(Handle<WasmInstanceObject> instance,
     return false;
   }
 
-  if (ValueTypes::IsReferenceType(global.type)) {
-    if (global.type == ValueType::kWasmFuncRef) {
+  if (global.type.IsReferenceType()) {
+    if (global.type == kWasmFuncRef) {
       if (!value->IsNull(isolate_) &&
           !WasmExportedFunction::IsWasmExportedFunction(*value)) {
         ReportLinkError(
@@ -1165,7 +1163,7 @@ bool InstanceBuilder::ProcessImportedGlobal(Handle<WasmInstanceObject> instance,
             import_index, module_name, import_name);
         return false;
       }
-    } else if (global.type == ValueType::kWasmNullRef) {
+    } else if (global.type == kWasmNullRef) {
       if (!value->IsNull(isolate_)) {
         ReportLinkError("imported nullref global must be null", import_index,
                         module_name, import_name);
@@ -1212,7 +1210,7 @@ void InstanceBuilder::CompileImportWrappers(
     }
     auto js_receiver = Handle<JSReceiver>::cast(value);
     uint32_t func_index = module_->import_table[index].index;
-    FunctionSig* sig = module_->functions[func_index].sig;
+    const FunctionSig* sig = module_->functions[func_index].sig;
     auto resolved = compiler::ResolveWasmImportCall(js_receiver, sig, enabled_);
     compiler::WasmImportCallKind kind = resolved.first;
     if (kind == compiler::WasmImportCallKind::kWasmToWasm ||
@@ -1378,7 +1376,7 @@ void InstanceBuilder::InitGlobals(Handle<WasmInstanceObject> instance) {
         uint32_t old_offset =
             module_->globals[global.init.val.global_index].offset;
         TRACE("init [globals+%u] = [globals+%d]\n", global.offset, old_offset);
-        if (ValueTypes::IsReferenceType(global.type)) {
+        if (global.type.IsReferenceType()) {
           DCHECK(enabled_.has_anyref() || enabled_.has_eh());
           tagged_globals_->set(new_offset, tagged_globals_->get(old_offset));
         } else {
@@ -1402,10 +1400,11 @@ void InstanceBuilder::InitGlobals(Handle<WasmInstanceObject> instance) {
 
 // Allocate memory for a module instance as a new JSArrayBuffer.
 bool InstanceBuilder::AllocateMemory() {
-  auto initial_pages = module_->initial_pages;
-  auto maximum_pages = module_->has_maximum_pages ? module_->maximum_pages
-                                                  : wasm::max_mem_pages();
-  if (initial_pages > max_mem_pages()) {
+  uint32_t initial_pages = module_->initial_pages;
+  uint32_t maximum_pages = module_->has_maximum_pages
+                               ? module_->maximum_pages
+                               : wasm::max_maximum_mem_pages();
+  if (initial_pages > max_initial_mem_pages()) {
     thrower_->RangeError("Out of memory: wasm memory too large");
     return false;
   }
@@ -1516,7 +1515,7 @@ void InstanceBuilder::ProcessExports(Handle<WasmInstanceObject> instance) {
         if (global.mutability && global.imported) {
           Handle<FixedArray> buffers_array(
               instance->imported_mutable_globals_buffers(), isolate_);
-          if (ValueTypes::IsReferenceType(global.type)) {
+          if (global.type.IsReferenceType()) {
             tagged_buffer = handle(
                 FixedArray::cast(buffers_array->get(global.index)), isolate_);
             // For anyref globals we store the relative offset in the
@@ -1540,7 +1539,7 @@ void InstanceBuilder::ProcessExports(Handle<WasmInstanceObject> instance) {
             offset = static_cast<uint32_t>(global_addr - backing_store);
           }
         } else {
-          if (ValueTypes::IsReferenceType(global.type)) {
+          if (global.type.IsReferenceType()) {
             tagged_buffer = handle(instance->tagged_globals_buffer(), isolate_);
           } else {
             untagged_buffer =
@@ -1685,7 +1684,7 @@ void InstanceBuilder::LoadTableSegments(Handle<WasmInstanceObject> instance) {
        segment_index < module_->elem_segments.size(); ++segment_index) {
     auto& elem_segment = instance->module()->elem_segments[segment_index];
     // Passive segments are not copied during instantiation.
-    if (!elem_segment.active) continue;
+    if (elem_segment.status != WasmElemSegment::kStatusActive) continue;
 
     uint32_t table_index = elem_segment.table_index;
     uint32_t dst = EvalUint32InitExpr(instance, elem_segment.offset);
diff --git a/deps/v8/src/wasm/value-type.h b/deps/v8/src/wasm/value-type.h
index 7a4c50303c..42230dfc06 100644
--- a/deps/v8/src/wasm/value-type.h
+++ b/deps/v8/src/wasm/value-type.h
@@ -29,31 +29,193 @@ class Simd128;
 // I32  I64  F32  F64    NullRef
 //   \    \    \    \    /
 //   ------------   Bottom
-enum ValueType : uint8_t {
-  kWasmStmt,
-  kWasmI32,
-  kWasmI64,
-  kWasmF32,
-  kWasmF64,
-  kWasmS128,
-  kWasmAnyRef,
-  kWasmFuncRef,
-  kWasmNullRef,
-  kWasmExnRef,
-  kWasmBottom,
+// Format: kind, log2Size, code, machineType, shortName, typeName
+#define FOREACH_VALUE_TYPE(V)                                                \
+  V(Stmt, -1, Void, None, 'v', "<stmt>")                                     \
+  V(I32, 2, I32, Int32, 'i', "i32")                                          \
+  V(I64, 3, I64, Int64, 'l', "i64")                                          \
+  V(F32, 2, F32, Float32, 'f', "f32")                                        \
+  V(F64, 3, F64, Float64, 'd', "f64")                                        \
+  V(S128, 4, S128, Simd128, 's', "s128")                                     \
+  V(AnyRef, kSystemPointerSizeLog2, AnyRef, TaggedPointer, 'r', "anyref")    \
+  V(FuncRef, kSystemPointerSizeLog2, FuncRef, TaggedPointer, 'a', "funcref") \
+  V(NullRef, kSystemPointerSizeLog2, NullRef, TaggedPointer, 'n', "nullref") \
+  V(ExnRef, kSystemPointerSizeLog2, ExnRef, TaggedPointer, 'e', "exn")       \
+  V(Bottom, -1, Void, None, '*', "<bot>")
+
+class ValueType {
+ public:
+  enum Kind : uint8_t {
+#define DEF_ENUM(kind, ...) k##kind,
+    FOREACH_VALUE_TYPE(DEF_ENUM)
+#undef DEF_ENUM
+  };
+
+  constexpr ValueType() : kind_(kStmt) {}
+  explicit constexpr ValueType(Kind kind) : kind_(kind) {}
+
+  constexpr Kind kind() const { return kind_; }
+
+  constexpr int element_size_log2() const {
+#if V8_HAS_CXX14_CONSTEXPR
+    DCHECK_NE(kStmt, kind_);
+    DCHECK_NE(kBottom, kind_);
+#endif
+
+    constexpr int kElementSizeLog2[] = {
+#define ELEM_SIZE_LOG2(kind, log2Size, ...) log2Size,
+        FOREACH_VALUE_TYPE(ELEM_SIZE_LOG2)
+#undef ELEM_SIZE_LOG2
+    };
+
+    return kElementSizeLog2[kind_];
+  }
+
+  constexpr int element_size_bytes() const { return 1 << element_size_log2(); }
+
+  constexpr bool operator==(ValueType other) const {
+    return kind_ == other.kind_;
+  }
+  constexpr bool operator!=(ValueType other) const {
+    return kind_ != other.kind_;
+  }
+
+  bool IsSubTypeOf(ValueType other) const {
+    return (*this == other) || (kind_ == kNullRef && other.kind_ == kAnyRef) ||
+           (kind_ == kFuncRef && other.kind_ == kAnyRef) ||
+           (kind_ == kExnRef && other.kind_ == kAnyRef) ||
+           (kind_ == kNullRef && other.kind_ == kFuncRef) ||
+           (kind_ == kNullRef && other.kind_ == kExnRef);
+  }
+
+  bool IsReferenceType() const {
+    return kind_ == kAnyRef || kind_ == kFuncRef || kind_ == kNullRef ||
+           kind_ == kExnRef;
+  }
+
+  static ValueType CommonSubType(ValueType a, ValueType b) {
+    if (a.kind() == b.kind()) return a;
+    // The only sub type of any value type is {bot}.
+    if (!a.IsReferenceType() || !b.IsReferenceType()) {
+      return ValueType(kBottom);
+    }
+    if (a.IsSubTypeOf(b)) return a;
+    if (b.IsSubTypeOf(a)) return b;
+    // {a} and {b} are not each other's subtype. The biggest sub-type of all
+    // reference types is {kWasmNullRef}.
+    return ValueType(kNullRef);
+  }
+
+  ValueTypeCode value_type_code() const {
+    DCHECK_NE(kBottom, kind_);
+
+    constexpr ValueTypeCode kValueTypeCode[] = {
+#define TYPE_CODE(kind, log2Size, code, ...) kLocal##code,
+        FOREACH_VALUE_TYPE(TYPE_CODE)
+#undef TYPE_CODE
+    };
+
+    return kValueTypeCode[kind_];
+  }
+
+  MachineType machine_type() const {
+    DCHECK_NE(kBottom, kind_);
+
+    constexpr MachineType kMachineType[] = {
+#define MACH_TYPE(kind, log2Size, code, machineType, ...) \
+  MachineType::machineType(),
+        FOREACH_VALUE_TYPE(MACH_TYPE)
+#undef MACH_TYPE
+    };
+
+    return kMachineType[kind_];
+  }
+
+  MachineRepresentation machine_representation() {
+    return machine_type().representation();
+  }
+
+  static ValueType For(MachineType type) {
+    switch (type.representation()) {
+      case MachineRepresentation::kWord8:
+      case MachineRepresentation::kWord16:
+      case MachineRepresentation::kWord32:
+        return ValueType(kI32);
+      case MachineRepresentation::kWord64:
+        return ValueType(kI64);
+      case MachineRepresentation::kFloat32:
+        return ValueType(kF32);
+      case MachineRepresentation::kFloat64:
+        return ValueType(kF64);
+      case MachineRepresentation::kTaggedPointer:
+        return ValueType(kAnyRef);
+      case MachineRepresentation::kSimd128:
+        return ValueType(kS128);
+      default:
+        UNREACHABLE();
+    }
+  }
+
+  constexpr char short_name() const {
+    constexpr char kShortName[] = {
+#define SHORT_NAME(kind, log2Size, code, machineType, shortName, ...) shortName,
+        FOREACH_VALUE_TYPE(SHORT_NAME)
+#undef SHORT_NAME
+    };
+
+    return kShortName[kind_];
+  }
+
+  constexpr const char* type_name() const {
+    constexpr const char* kTypeName[] = {
+#define TYPE_NAME(kind, log2Size, code, machineType, shortName, typeName, ...) \
+  typeName,
+        FOREACH_VALUE_TYPE(TYPE_NAME)
+#undef TYPE_NAME
+    };
+
+    return kTypeName[kind_];
+  }
+
+ private:
+  Kind kind_ : 8;
+  // TODO(jkummerow): Add and use the following for reference types:
+  // uint32_t ref_index_ : 24;
 };
 
+static_assert(sizeof(ValueType) <= kUInt32Size,
+              "ValueType is small and can be passed by value");
+
+inline size_t hash_value(ValueType type) {
+  return static_cast<size_t>(type.kind());
+}
+
+// Output operator, useful for DCHECKS and others.
+inline std::ostream& operator<<(std::ostream& oss, ValueType type) {
+  return oss << type.type_name();
+}
+
+constexpr ValueType kWasmI32 = ValueType(ValueType::kI32);
+constexpr ValueType kWasmI64 = ValueType(ValueType::kI64);
+constexpr ValueType kWasmF32 = ValueType(ValueType::kF32);
+constexpr ValueType kWasmF64 = ValueType(ValueType::kF64);
+constexpr ValueType kWasmAnyRef = ValueType(ValueType::kAnyRef);
+constexpr ValueType kWasmExnRef = ValueType(ValueType::kExnRef);
+constexpr ValueType kWasmFuncRef = ValueType(ValueType::kFuncRef);
+constexpr ValueType kWasmNullRef = ValueType(ValueType::kNullRef);
+constexpr ValueType kWasmS128 = ValueType(ValueType::kS128);
+constexpr ValueType kWasmStmt = ValueType(ValueType::kStmt);
+constexpr ValueType kWasmBottom = ValueType(ValueType::kBottom);
+
 #define FOREACH_WASMVALUE_CTYPES(V) \
-  V(kWasmI32, int32_t)              \
-  V(kWasmI64, int64_t)              \
-  V(kWasmF32, float)                \
-  V(kWasmF64, double)               \
-  V(kWasmS128, Simd128)
+  V(kI32, int32_t)                  \
+  V(kI64, int64_t)                  \
+  V(kF32, float)                    \
+  V(kF64, double)                   \
+  V(kS128, Simd128)
 
 using FunctionSig = Signature<ValueType>;
 
-inline size_t hash_value(ValueType type) { return static_cast<size_t>(type); }
-
 #define FOREACH_LOAD_TYPE(V) \
   V(I32, , Int32)            \
   V(I32, 8S, Int8)           \
@@ -79,7 +241,7 @@ class LoadType {
 #undef DEF_ENUM
   };
 
-  // Allow implicit convertion of the enum value to this wrapper.
+  // Allow implicit conversion of the enum value to this wrapper.
   constexpr LoadType(LoadTypeValue val)  // NOLINT(runtime/explicit)
       : val_(val) {}
 
@@ -90,16 +252,16 @@ class LoadType {
   constexpr MachineType mem_type() const { return kMemType[val_]; }
 
   static LoadType ForValueType(ValueType type) {
-    switch (type) {
-      case kWasmI32:
+    switch (type.kind()) {
+      case ValueType::kI32:
         return kI32Load;
-      case kWasmI64:
+      case ValueType::kI64:
         return kI64Load;
-      case kWasmF32:
+      case ValueType::kF32:
         return kF32Load;
-      case kWasmF64:
+      case ValueType::kF64:
         return kF64Load;
-      case kWasmS128:
+      case ValueType::kS128:
         return kS128Load;
       default:
         UNREACHABLE();
@@ -119,7 +281,7 @@ class LoadType {
   };
 
   static constexpr ValueType kValueType[] = {
-#define VALUE_TYPE(type, ...) kWasm##type,
+#define VALUE_TYPE(type, ...) ValueType(ValueType::k##type),
       FOREACH_LOAD_TYPE(VALUE_TYPE)
 #undef VALUE_TYPE
   };
@@ -162,16 +324,16 @@ class StoreType {
   constexpr MachineRepresentation mem_rep() const { return kMemRep[val_]; }
 
   static StoreType ForValueType(ValueType type) {
-    switch (type) {
-      case kWasmI32:
+    switch (type.kind()) {
+      case ValueType::kI32:
         return kI32Store;
-      case kWasmI64:
+      case ValueType::kI64:
         return kI64Store;
-      case kWasmF32:
+      case ValueType::kF32:
         return kF32Store;
-      case kWasmF64:
+      case ValueType::kF64:
         return kF64Store;
-      case kWasmS128:
+      case ValueType::kS128:
         return kS128Store;
       default:
         UNREACHABLE();
@@ -190,7 +352,7 @@ class StoreType {
   };
 
   static constexpr ValueType kValueType[] = {
-#define VALUE_TYPE(type, ...) kWasm##type,
+#define VALUE_TYPE(type, ...) ValueType(ValueType::k##type),
       FOREACH_STORE_TYPE(VALUE_TYPE)
 #undef VALUE_TYPE
   };
@@ -202,235 +364,6 @@ class StoreType {
   };
 };
 
-// A collection of ValueType-related static methods.
-class V8_EXPORT_PRIVATE ValueTypes {
- public:
-  static inline bool IsSubType(ValueType actual, ValueType expected) {
-    return (expected == actual) ||
-           (expected == kWasmAnyRef && actual == kWasmNullRef) ||
-           (expected == kWasmAnyRef && actual == kWasmFuncRef) ||
-           (expected == kWasmAnyRef && actual == kWasmExnRef) ||
-           (expected == kWasmFuncRef && actual == kWasmNullRef) ||
-           (expected == kWasmExnRef && actual == kWasmNullRef);
-  }
-
-  static inline bool IsReferenceType(ValueType type) {
-    return type == kWasmAnyRef || type == kWasmFuncRef ||
-           type == kWasmNullRef || type == kWasmExnRef;
-  }
-
-  static inline ValueType CommonSubType(ValueType a, ValueType b) {
-    if (a == b) return a;
-    // The only sub type of any value type is {bot}.
-    if (!IsReferenceType(a) || !IsReferenceType(b)) return kWasmBottom;
-    if (IsSubType(a, b)) return a;
-    if (IsSubType(b, a)) return b;
-    // {a} and {b} are not each other's subtype. The biggest sub-type of all
-    // reference types is {kWasmNullRef}.
-    return kWasmNullRef;
-  }
-
-  static byte MemSize(MachineType type) {
-    return 1 << i::ElementSizeLog2Of(type.representation());
-  }
-
-  static int ElementSizeInBytes(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-      case kWasmF32:
-        return 4;
-      case kWasmI64:
-      case kWasmF64:
-        return 8;
-      case kWasmS128:
-        return 16;
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
-        return kSystemPointerSize;
-      case kWasmStmt:
-      case kWasmBottom:
-        UNREACHABLE();
-    }
-  }
-
-  static int ElementSizeLog2Of(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-      case kWasmF32:
-        return 2;
-      case kWasmI64:
-      case kWasmF64:
-        return 3;
-      case kWasmS128:
-        return 4;
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
-        return kSystemPointerSizeLog2;
-      case kWasmStmt:
-      case kWasmBottom:
-        UNREACHABLE();
-    }
-  }
-
-  static byte MemSize(ValueType type) { return 1 << ElementSizeLog2Of(type); }
-
-  static ValueTypeCode ValueTypeCodeFor(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-        return kLocalI32;
-      case kWasmI64:
-        return kLocalI64;
-      case kWasmF32:
-        return kLocalF32;
-      case kWasmF64:
-        return kLocalF64;
-      case kWasmS128:
-        return kLocalS128;
-      case kWasmAnyRef:
-        return kLocalAnyRef;
-      case kWasmFuncRef:
-        return kLocalFuncRef;
-      case kWasmNullRef:
-        return kLocalNullRef;
-      case kWasmExnRef:
-        return kLocalExnRef;
-      case kWasmStmt:
-        return kLocalVoid;
-      case kWasmBottom:
-        UNREACHABLE();
-    }
-  }
-
-  static MachineType MachineTypeFor(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-        return MachineType::Int32();
-      case kWasmI64:
-        return MachineType::Int64();
-      case kWasmF32:
-        return MachineType::Float32();
-      case kWasmF64:
-        return MachineType::Float64();
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
-        return MachineType::TaggedPointer();
-      case kWasmS128:
-        return MachineType::Simd128();
-      case kWasmStmt:
-        return MachineType::None();
-      case kWasmBottom:
-        UNREACHABLE();
-    }
-  }
-
-  static MachineRepresentation MachineRepresentationFor(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-        return MachineRepresentation::kWord32;
-      case kWasmI64:
-        return MachineRepresentation::kWord64;
-      case kWasmF32:
-        return MachineRepresentation::kFloat32;
-      case kWasmF64:
-        return MachineRepresentation::kFloat64;
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
-        return MachineRepresentation::kTaggedPointer;
-      case kWasmS128:
-        return MachineRepresentation::kSimd128;
-      case kWasmStmt:
-        return MachineRepresentation::kNone;
-      case kWasmBottom:
-        UNREACHABLE();
-    }
-  }
-
-  static ValueType ValueTypeFor(MachineType type) {
-    switch (type.representation()) {
-      case MachineRepresentation::kWord8:
-      case MachineRepresentation::kWord16:
-      case MachineRepresentation::kWord32:
-        return kWasmI32;
-      case MachineRepresentation::kWord64:
-        return kWasmI64;
-      case MachineRepresentation::kFloat32:
-        return kWasmF32;
-      case MachineRepresentation::kFloat64:
-        return kWasmF64;
-      case MachineRepresentation::kTaggedPointer:
-        return kWasmAnyRef;
-      case MachineRepresentation::kSimd128:
-        return kWasmS128;
-      default:
-        UNREACHABLE();
-    }
-  }
-
-  static char ShortNameOf(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-        return 'i';
-      case kWasmI64:
-        return 'l';
-      case kWasmF32:
-        return 'f';
-      case kWasmF64:
-        return 'd';
-      case kWasmAnyRef:
-        return 'r';
-      case kWasmFuncRef:
-        return 'a';
-      case kWasmS128:
-        return 's';
-      case kWasmStmt:
-        return 'v';
-      case kWasmNullRef:
-        return 'n';
-      case kWasmExnRef:
-      case kWasmBottom:
-        return '*';
-    }
-  }
-
-  static const char* TypeName(ValueType type) {
-    switch (type) {
-      case kWasmI32:
-        return "i32";
-      case kWasmI64:
-        return "i64";
-      case kWasmF32:
-        return "f32";
-      case kWasmF64:
-        return "f64";
-      case kWasmAnyRef:
-        return "anyref";
-      case kWasmFuncRef:
-        return "funcref";
-      case kWasmNullRef:
-        return "nullref";
-      case kWasmExnRef:
-        return "exn";
-      case kWasmS128:
-        return "s128";
-      case kWasmStmt:
-        return "<stmt>";
-      case kWasmBottom:
-        return "<bot>";
-    }
-  }
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ValueTypes);
-};
-
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/wasm/wasm-arguments.h b/deps/v8/src/wasm/wasm-arguments.h
index 822f46addd..e6f212b2d9 100644
--- a/deps/v8/src/wasm/wasm-arguments.h
+++ b/deps/v8/src/wasm/wasm-arguments.h
@@ -45,14 +45,14 @@ class CWasmArgumentsPacker {
     return base::ReadUnalignedValue<T>(address);
   }
 
-  static int TotalSize(FunctionSig* sig) {
+  static int TotalSize(const FunctionSig* sig) {
     int return_size = 0;
     for (ValueType t : sig->returns()) {
-      return_size += ValueTypes::ElementSizeInBytes(t);
+      return_size += t.element_size_bytes();
     }
     int param_size = 0;
     for (ValueType t : sig->parameters()) {
-      param_size += ValueTypes::ElementSizeInBytes(t);
+      param_size += t.element_size_bytes();
     }
     return std::max(return_size, param_size);
   }
diff --git a/deps/v8/src/wasm/wasm-code-manager.cc b/deps/v8/src/wasm/wasm-code-manager.cc
index 8eb0f5d97f..99cf484b17 100644
--- a/deps/v8/src/wasm/wasm-code-manager.cc
+++ b/deps/v8/src/wasm/wasm-code-manager.cc
@@ -133,31 +133,47 @@ Address WasmCode::handler_table() const {
   return instruction_start() + handler_table_offset_;
 }
 
-uint32_t WasmCode::handler_table_size() const {
+int WasmCode::handler_table_size() const {
   DCHECK_GE(constant_pool_offset_, handler_table_offset_);
-  return static_cast<uint32_t>(constant_pool_offset_ - handler_table_offset_);
+  return static_cast<int>(constant_pool_offset_ - handler_table_offset_);
 }
 
 Address WasmCode::code_comments() const {
   return instruction_start() + code_comments_offset_;
 }
 
-uint32_t WasmCode::code_comments_size() const {
+int WasmCode::code_comments_size() const {
   DCHECK_GE(unpadded_binary_size_, code_comments_offset_);
-  return static_cast<uint32_t>(unpadded_binary_size_ - code_comments_offset_);
+  return static_cast<int>(unpadded_binary_size_ - code_comments_offset_);
+}
+
+std::unique_ptr<const byte[]> WasmCode::ConcatenateBytes(
+    std::initializer_list<Vector<const byte>> vectors) {
+  size_t total_size = 0;
+  for (auto& vec : vectors) total_size += vec.size();
+  // Use default-initialization (== no initialization).
+  std::unique_ptr<byte[]> result{new byte[total_size]};
+  byte* ptr = result.get();
+  for (auto& vec : vectors) {
+    if (vec.empty()) continue;  // Avoid nullptr in {memcpy}.
+    memcpy(ptr, vec.begin(), vec.size());
+    ptr += vec.size();
+  }
+  return result;
 }
 
 void WasmCode::RegisterTrapHandlerData() {
   DCHECK(!has_trap_handler_index());
   if (kind() != WasmCode::kFunction) return;
-  if (protected_instructions_.empty()) return;
+  if (protected_instructions_size_ == 0) return;
 
   Address base = instruction_start();
 
   size_t size = instructions().size();
+  auto protected_instruction_data = this->protected_instructions();
   const int index =
-      RegisterHandlerData(base, size, protected_instructions().size(),
-                          protected_instructions().begin());
+      RegisterHandlerData(base, size, protected_instruction_data.size(),
+                          protected_instruction_data.begin());
 
   // TODO(eholk): if index is negative, fail.
   CHECK_LE(0, index);
@@ -179,8 +195,8 @@ void WasmCode::LogCode(Isolate* isolate) const {
   if (IsAnonymous()) return;
 
   ModuleWireBytes wire_bytes(native_module()->wire_bytes());
-  WireBytesRef name_ref =
-      native_module()->module()->function_names.Lookup(wire_bytes, index());
+  WireBytesRef name_ref = native_module()->module()->function_names.Lookup(
+      wire_bytes, index(), VectorOf(native_module()->module()->export_table));
   WasmName name = wire_bytes.GetNameOrNull(name_ref);
 
   const std::string& source_map_url = native_module()->module()->source_map_url;
@@ -195,28 +211,28 @@ void WasmCode::LogCode(Isolate* isolate) const {
         std::make_unique<WasmModuleSourceMap>(v8_isolate, source_map_str));
   }
 
-  std::unique_ptr<char[]> name_buffer;
+  std::string name_buffer;
   if (kind_ == kWasmToJsWrapper) {
-    constexpr size_t kNameBufferLen = 128;
-    constexpr size_t kNamePrefixLen = 11;
-    name_buffer = std::make_unique<char[]>(kNameBufferLen);
-    memcpy(name_buffer.get(), "wasm-to-js:", kNamePrefixLen);
-    Vector<char> remaining_buf =
-        VectorOf(name_buffer.get(), kNameBufferLen) + kNamePrefixLen;
-    FunctionSig* sig = native_module()->module()->functions[index_].sig;
-    remaining_buf += PrintSignature(remaining_buf, sig);
+    name_buffer = "wasm-to-js:";
+    size_t prefix_len = name_buffer.size();
+    constexpr size_t kMaxSigLength = 128;
+    name_buffer.resize(prefix_len + kMaxSigLength);
+    const FunctionSig* sig = native_module()->module()->functions[index_].sig;
+    size_t sig_length =
+        PrintSignature(VectorOf(&name_buffer[prefix_len], kMaxSigLength), sig);
+    name_buffer.resize(prefix_len + sig_length);
     // If the import has a name, also append that (separated by "-").
-    if (!name.empty() && remaining_buf.length() > 1) {
-      remaining_buf[0] = '-';
-      remaining_buf += 1;
-      size_t suffix_len = std::min(name.size(), remaining_buf.size());
-      memcpy(remaining_buf.begin(), name.begin(), suffix_len);
-      remaining_buf += suffix_len;
+    if (!name.empty()) {
+      name_buffer += '-';
+      name_buffer.append(name.begin(), name.size());
     }
-    size_t name_len = remaining_buf.begin() - name_buffer.get();
-    name = VectorOf(name_buffer.get(), name_len);
+    name = VectorOf(name_buffer);
   } else if (name.empty()) {
-    name = CStrVector("<wasm-unnamed>");
+    name_buffer.resize(32);
+    name_buffer.resize(
+        SNPrintF(VectorOf(&name_buffer.front(), name_buffer.size()),
+                 "wasm-function[%d]", index()));
+    name = VectorOf(name_buffer);
   }
   PROFILE(isolate,
           CodeCreateEvent(CodeEventListener::FUNCTION_TAG, this, name));
@@ -296,7 +312,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
      << unpadded_binary_size_ << " + " << padding << " padding)\n";
 
 #ifdef ENABLE_DISASSEMBLER
-  size_t instruction_size = unpadded_binary_size_;
+  int instruction_size = unpadded_binary_size_;
   if (constant_pool_offset_ < instruction_size) {
     instruction_size = constant_pool_offset_;
   }
@@ -322,7 +338,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
     os << "\n";
   }
 
-  if (!protected_instructions_.empty()) {
+  if (protected_instructions_size_ > 0) {
     os << "Protected instructions:\n pc offset  land pad\n";
     for (auto& data : protected_instructions()) {
       os << std::setw(10) << std::hex << data.instr_offset << std::setw(10)
@@ -364,7 +380,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
     os << "\n";
   }
 
-  os << "RelocInfo (size = " << reloc_info_.size() << ")\n";
+  os << "RelocInfo (size = " << reloc_info().size() << ")\n";
   for (RelocIterator it(instructions(), reloc_info(), constant_pool());
        !it.done(); it.next()) {
     it.rinfo()->Print(nullptr, os);
@@ -440,13 +456,11 @@ void WasmCodeAllocator::OptionalLock::Lock(WasmCodeAllocator* allocator) {
 
 WasmCodeAllocator::WasmCodeAllocator(WasmCodeManager* code_manager,
                                      VirtualMemory code_space,
-                                     bool can_request_more,
                                      std::shared_ptr<Counters> async_counters)
     : code_manager_(code_manager),
       free_code_space_(code_space.region()),
-      can_request_more_memory_(can_request_more),
       async_counters_(std::move(async_counters)) {
-  owned_code_space_.reserve(can_request_more ? 4 : 1);
+  owned_code_space_.reserve(4);
   owned_code_space_.emplace_back(std::move(code_space));
   async_counters_->wasm_module_num_code_spaces()->AddSample(1);
 }
@@ -502,8 +516,7 @@ base::SmallVector<base::AddressRegion, 1> SplitRangeByReservationsIfNeeded(
 }
 
 int NumWasmFunctionsInFarJumpTable(uint32_t num_declared_functions) {
-  return NativeModule::kNeedsFarJumpsBetweenCodeSpaces &&
-                 FLAG_wasm_far_jump_table
+  return NativeModule::kNeedsFarJumpsBetweenCodeSpaces
              ? static_cast<int>(num_declared_functions)
              : 0;
 }
@@ -571,12 +584,8 @@ Vector<byte> WasmCodeAllocator::AllocateForCodeInRegion(
   base::AddressRegion code_space =
       free_code_space_.AllocateInRegion(size, region);
   if (code_space.is_empty()) {
-    const bool in_specific_region =
-        region.size() < std::numeric_limits<size_t>::max();
-    if (!can_request_more_memory_ || in_specific_region) {
-      auto error = in_specific_region ? "wasm code reservation in region"
-                                      : "wasm code reservation";
-      V8::FatalProcessOutOfMemory(nullptr, error);
+    if (region.size() < std::numeric_limits<size_t>::max()) {
+      V8::FatalProcessOutOfMemory(nullptr, "wasm code reservation in region");
       UNREACHABLE();
     }
 
@@ -649,26 +658,20 @@ bool WasmCodeAllocator::SetExecutable(bool executable) {
         executable ? PageAllocator::kReadExecute : PageAllocator::kReadWrite;
 #if V8_OS_WIN
     // On windows, we need to switch permissions per separate virtual memory
-    // reservation. This is really just a problem when the NativeModule is
-    // growable (meaning can_request_more_memory_). That's 32-bit in production,
-    // or unittests.
+    // reservation.
     // For now, in that case, we commit at reserved memory granularity.
     // Technically, that may be a waste, because we may reserve more than we
     // use. On 32-bit though, the scarce resource is the address space -
     // committed or not.
-    if (can_request_more_memory_) {
-      for (auto& vmem : owned_code_space_) {
-        if (!SetPermissions(page_allocator, vmem.address(), vmem.size(),
-                            permission)) {
-          return false;
-        }
-        TRACE_HEAP("Set %p:%p to executable:%d\n", vmem.address(), vmem.end(),
-                   executable);
+    for (auto& vmem : owned_code_space_) {
+      if (!SetPermissions(page_allocator, vmem.address(), vmem.size(),
+                          permission)) {
+        return false;
       }
-      is_executable_ = executable;
-      return true;
+      TRACE_HEAP("Set %p:%p to executable:%d\n", vmem.address(), vmem.end(),
+                 executable);
     }
-#endif
+#else   // V8_OS_WIN
     size_t commit_page_size = page_allocator->CommitPageSize();
     for (auto& region : allocated_code_space_.regions()) {
       // allocated_code_space_ is fine-grained, so we need to
@@ -681,6 +684,7 @@ bool WasmCodeAllocator::SetExecutable(bool executable) {
       TRACE_HEAP("Set 0x%" PRIxPTR ":0x%" PRIxPTR " to executable:%d\n",
                  region.begin(), region.end(), executable);
     }
+#endif  // V8_OS_WIN
   }
   is_executable_ = executable;
   return true;
@@ -730,12 +734,12 @@ size_t WasmCodeAllocator::GetNumCodeSpaces() const {
 }
 
 NativeModule::NativeModule(WasmEngine* engine, const WasmFeatures& enabled,
-                           bool can_request_more, VirtualMemory code_space,
+                           VirtualMemory code_space,
                            std::shared_ptr<const WasmModule> module,
                            std::shared_ptr<Counters> async_counters,
                            std::shared_ptr<NativeModule>* shared_this)
     : code_allocator_(engine->code_manager(), std::move(code_space),
-                      can_request_more, async_counters),
+                      async_counters),
       enabled_features_(enabled),
       module_(std::move(module)),
       import_wrapper_cache_(std::unique_ptr<WasmImportWrapperCache>(
@@ -796,8 +800,10 @@ void NativeModule::LogWasmCodes(Isolate* isolate) {
 }
 
 CompilationEnv NativeModule::CreateCompilationEnv() const {
-  return {module(), use_trap_handler_, kRuntimeExceptionSupport,
-          enabled_features_};
+  // Protect concurrent accesses to {tier_down_}.
+  base::MutexGuard guard(&allocation_mutex_);
+  return {module(),          use_trap_handler_, kRuntimeExceptionSupport,
+          enabled_features_, kNoLowerSimd,      tier_down_};
 }
 
 WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
@@ -822,20 +828,16 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   Vector<const byte> instructions(
       reinterpret_cast<byte*>(code->InstructionStart()),
       static_cast<size_t>(code->InstructionSize()));
-  const uint32_t stack_slots = static_cast<uint32_t>(
-      code->has_safepoint_info() ? code->stack_slots() : 0);
+  const int stack_slots = code->has_safepoint_info() ? code->stack_slots() : 0;
 
   // TODO(jgruber,v8:8758): Remove this translation. It exists only because
   // Code objects contains real offsets but WasmCode expects an offset of 0 to
   // mean 'empty'.
-  const size_t safepoint_table_offset = static_cast<size_t>(
-      code->has_safepoint_table() ? code->safepoint_table_offset() : 0);
-  const size_t handler_table_offset =
-      static_cast<size_t>(code->handler_table_offset());
-  const size_t constant_pool_offset =
-      static_cast<size_t>(code->constant_pool_offset());
-  const size_t code_comments_offset =
-      static_cast<size_t>(code->code_comments_offset());
+  const int safepoint_table_offset =
+      code->has_safepoint_table() ? code->safepoint_table_offset() : 0;
+  const int handler_table_offset = code->handler_table_offset();
+  const int constant_pool_offset = code->constant_pool_offset();
+  const int code_comments_offset = code->code_comments_offset();
 
   Vector<uint8_t> dst_code_bytes =
       code_allocator_.AllocateForCode(this, instructions.size());
@@ -844,10 +846,10 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   // Apply the relocation delta by iterating over the RelocInfo.
   intptr_t delta = reinterpret_cast<Address>(dst_code_bytes.begin()) -
                    code->InstructionStart();
-  int mode_mask = RelocInfo::kApplyMask |
-                  RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
+  int mode_mask =
+      RelocInfo::kApplyMask | RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
   auto jump_tables_ref =
-      FindJumpTablesForCode(reinterpret_cast<Address>(dst_code_bytes.begin()));
+      FindJumpTablesForRegion(base::AddressRegionOf(dst_code_bytes));
   Address dst_code_addr = reinterpret_cast<Address>(dst_code_bytes.begin());
   Address constant_pool_start = dst_code_addr + constant_pool_offset;
   RelocIterator orig_it(*code, mode_mask);
@@ -869,22 +871,22 @@ WasmCode* NativeModule::AddCodeForTesting(Handle<Code> code) {
   // Flush the i-cache after relocation.
   FlushInstructionCache(dst_code_bytes.begin(), dst_code_bytes.size());
 
-  std::unique_ptr<WasmCode> new_code{new WasmCode{
-      this,                                     // native_module
-      kAnonymousFuncIndex,                      // index
-      dst_code_bytes,                           // instructions
-      stack_slots,                              // stack_slots
-      0,                                        // tagged_parameter_slots
-      safepoint_table_offset,                   // safepoint_table_offset
-      handler_table_offset,                     // handler_table_offset
-      constant_pool_offset,                     // constant_pool_offset
-      code_comments_offset,                     // code_comments_offset
-      instructions.size(),                      // unpadded_binary_size
-      OwnedVector<ProtectedInstructionData>{},  // protected_instructions
-      std::move(reloc_info),                    // reloc_info
-      std::move(source_pos),                    // source positions
-      WasmCode::kFunction,                      // kind
-      ExecutionTier::kNone}};                   // tier
+  std::unique_ptr<WasmCode> new_code{
+      new WasmCode{this,                    // native_module
+                   kAnonymousFuncIndex,     // index
+                   dst_code_bytes,          // instructions
+                   stack_slots,             // stack_slots
+                   0,                       // tagged_parameter_slots
+                   safepoint_table_offset,  // safepoint_table_offset
+                   handler_table_offset,    // handler_table_offset
+                   constant_pool_offset,    // constant_pool_offset
+                   code_comments_offset,    // code_comments_offset
+                   instructions.length(),   // unpadded_binary_size
+                   {},                      // protected_instructions
+                   reloc_info.as_vector(),  // reloc_info
+                   source_pos.as_vector(),  // source positions
+                   WasmCode::kFunction,     // kind
+                   ExecutionTier::kNone}};  // tier
   new_code->MaybePrint(nullptr);
   new_code->Validate();
 
@@ -911,9 +913,9 @@ void NativeModule::UseLazyStub(uint32_t func_index) {
     JumpTableAssembler::GenerateLazyCompileTable(
         lazy_compile_table_->instruction_start(), num_slots,
         module_->num_imported_functions,
-        GetNearRuntimeStubEntry(
-            WasmCode::kWasmCompileLazy,
-            FindJumpTablesForCode(lazy_compile_table_->instruction_start())));
+        GetNearRuntimeStubEntry(WasmCode::kWasmCompileLazy,
+                                FindJumpTablesForRegion(base::AddressRegionOf(
+                                    lazy_compile_table_->instructions()))));
   }
 
   // Add jump table entry for jump to the lazy compile stub.
@@ -927,47 +929,38 @@ void NativeModule::UseLazyStub(uint32_t func_index) {
 }
 
 std::unique_ptr<WasmCode> NativeModule::AddCode(
-    uint32_t index, const CodeDesc& desc, uint32_t stack_slots,
-    uint32_t tagged_parameter_slots,
-    OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions,
-    OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
+    int index, const CodeDesc& desc, int stack_slots,
+    int tagged_parameter_slots, Vector<const byte> protected_instructions_data,
+    Vector<const byte> source_position_table, WasmCode::Kind kind,
     ExecutionTier tier) {
   Vector<byte> code_space =
       code_allocator_.AllocateForCode(this, desc.instr_size);
   auto jump_table_ref =
-      FindJumpTablesForCode(reinterpret_cast<Address>(code_space.begin()));
+      FindJumpTablesForRegion(base::AddressRegionOf(code_space));
   return AddCodeWithCodeSpace(index, desc, stack_slots, tagged_parameter_slots,
-                              std::move(protected_instructions),
-                              std::move(source_position_table), kind, tier,
-                              code_space, jump_table_ref);
+                              protected_instructions_data,
+                              source_position_table, kind, tier, code_space,
+                              jump_table_ref);
 }
 
 std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
-    uint32_t index, const CodeDesc& desc, uint32_t stack_slots,
-    uint32_t tagged_parameter_slots,
-    OwnedVector<ProtectedInstructionData> protected_instructions,
-    OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
+    int index, const CodeDesc& desc, int stack_slots,
+    int tagged_parameter_slots, Vector<const byte> protected_instructions_data,
+    Vector<const byte> source_position_table, WasmCode::Kind kind,
     ExecutionTier tier, Vector<uint8_t> dst_code_bytes,
-    const JumpTablesRef& jump_tables_ref) {
-  OwnedVector<byte> reloc_info;
-  if (desc.reloc_size > 0) {
-    reloc_info = OwnedVector<byte>::New(desc.reloc_size);
-    memcpy(reloc_info.start(), desc.buffer + desc.buffer_size - desc.reloc_size,
-           desc.reloc_size);
-  }
+    const JumpTablesRef& jump_tables) {
+  Vector<byte> reloc_info{desc.buffer + desc.buffer_size - desc.reloc_size,
+                          static_cast<size_t>(desc.reloc_size)};
 
   // TODO(jgruber,v8:8758): Remove this translation. It exists only because
   // CodeDesc contains real offsets but WasmCode expects an offset of 0 to mean
   // 'empty'.
-  const size_t safepoint_table_offset = static_cast<size_t>(
-      desc.safepoint_table_size == 0 ? 0 : desc.safepoint_table_offset);
-  const size_t handler_table_offset =
-      static_cast<size_t>(desc.handler_table_offset);
-  const size_t constant_pool_offset =
-      static_cast<size_t>(desc.constant_pool_offset);
-  const size_t code_comments_offset =
-      static_cast<size_t>(desc.code_comments_offset);
-  const size_t instr_size = static_cast<size_t>(desc.instr_size);
+  const int safepoint_table_offset =
+      desc.safepoint_table_size == 0 ? 0 : desc.safepoint_table_offset;
+  const int handler_table_offset = desc.handler_table_offset;
+  const int constant_pool_offset = desc.constant_pool_offset;
+  const int code_comments_offset = desc.code_comments_offset;
+  const int instr_size = desc.instr_size;
 
   memcpy(dst_code_bytes.begin(), desc.buffer,
          static_cast<size_t>(desc.instr_size));
@@ -979,19 +972,19 @@ std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
                   RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
   Address code_start = reinterpret_cast<Address>(dst_code_bytes.begin());
   Address constant_pool_start = code_start + constant_pool_offset;
-  for (RelocIterator it(dst_code_bytes, reloc_info.as_vector(),
-                        constant_pool_start, mode_mask);
+  for (RelocIterator it(dst_code_bytes, reloc_info, constant_pool_start,
+                        mode_mask);
        !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (RelocInfo::IsWasmCall(mode)) {
       uint32_t call_tag = it.rinfo()->wasm_call_tag();
-      Address target = GetNearCallTargetForFunction(call_tag, jump_tables_ref);
+      Address target = GetNearCallTargetForFunction(call_tag, jump_tables);
       it.rinfo()->set_wasm_call_address(target, SKIP_ICACHE_FLUSH);
     } else if (RelocInfo::IsWasmStubCall(mode)) {
       uint32_t stub_call_tag = it.rinfo()->wasm_call_tag();
       DCHECK_LT(stub_call_tag, WasmCode::kRuntimeStubCount);
       Address entry = GetNearRuntimeStubEntry(
-          static_cast<WasmCode::RuntimeStubId>(stub_call_tag), jump_tables_ref);
+          static_cast<WasmCode::RuntimeStubId>(stub_call_tag), jump_tables);
       it.rinfo()->set_wasm_stub_call_address(entry, SKIP_ICACHE_FLUSH);
     } else {
       it.rinfo()->apply(delta);
@@ -1004,8 +997,8 @@ std::unique_ptr<WasmCode> NativeModule::AddCodeWithCodeSpace(
   std::unique_ptr<WasmCode> code{new WasmCode{
       this, index, dst_code_bytes, stack_slots, tagged_parameter_slots,
       safepoint_table_offset, handler_table_offset, constant_pool_offset,
-      code_comments_offset, instr_size, std::move(protected_instructions),
-      std::move(reloc_info), std::move(source_position_table), kind, tier}};
+      code_comments_offset, instr_size, protected_instructions_data, reloc_info,
+      source_position_table, kind, tier}};
   code->MaybePrint();
   code->Validate();
 
@@ -1052,9 +1045,11 @@ WasmCode* NativeModule::PublishCodeLocked(std::unique_ptr<WasmCode> code) {
     // tier.
     uint32_t slot_idx = declared_function_index(module(), code->index());
     WasmCode* prior_code = code_table_[slot_idx];
-    bool update_code_table =
-        tier_down_ ? !prior_code || code->tier() == ExecutionTier::kLiftoff
-                   : !prior_code || prior_code->tier() < code->tier();
+    // TODO(clemensb): Revisit this logic once tier down is fully working.
+    const bool prefer_liftoff = tier_down_ || debug_info_;
+    const bool update_code_table =
+        prefer_liftoff ? !prior_code || code->tier() == ExecutionTier::kLiftoff
+                       : !prior_code || prior_code->tier() < code->tier();
     if (update_code_table) {
       code_table_[slot_idx] = code.get();
       if (prior_code) {
@@ -1088,14 +1083,13 @@ WasmCode* NativeModule::PublishCodeLocked(std::unique_ptr<WasmCode> code) {
 }
 
 WasmCode* NativeModule::AddDeserializedCode(
-    uint32_t index, Vector<const byte> instructions, uint32_t stack_slots,
-    uint32_t tagged_parameter_slots, size_t safepoint_table_offset,
-    size_t handler_table_offset, size_t constant_pool_offset,
-    size_t code_comments_offset, size_t unpadded_binary_size,
-    OwnedVector<ProtectedInstructionData> protected_instructions,
-    OwnedVector<const byte> reloc_info,
-    OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
-    ExecutionTier tier) {
+    int index, Vector<const byte> instructions, int stack_slots,
+    int tagged_parameter_slots, int safepoint_table_offset,
+    int handler_table_offset, int constant_pool_offset,
+    int code_comments_offset, int unpadded_binary_size,
+    Vector<const byte> protected_instructions_data,
+    Vector<const byte> reloc_info, Vector<const byte> source_position_table,
+    WasmCode::Kind kind, ExecutionTier tier) {
   Vector<uint8_t> dst_code_bytes =
       code_allocator_.AllocateForCode(this, instructions.size());
   memcpy(dst_code_bytes.begin(), instructions.begin(), instructions.size());
@@ -1103,9 +1097,8 @@ WasmCode* NativeModule::AddDeserializedCode(
   std::unique_ptr<WasmCode> code{new WasmCode{
       this, index, dst_code_bytes, stack_slots, tagged_parameter_slots,
       safepoint_table_offset, handler_table_offset, constant_pool_offset,
-      code_comments_offset, unpadded_binary_size,
-      std::move(protected_instructions), std::move(reloc_info),
-      std::move(source_position_table), kind, tier}};
+      code_comments_offset, unpadded_binary_size, protected_instructions_data,
+      reloc_info, source_position_table, kind, tier}};
 
   // Note: we do not flush the i-cache here, since the code needs to be
   // relocated anyway. The caller is responsible for flushing the i-cache later.
@@ -1132,6 +1125,12 @@ bool NativeModule::HasCode(uint32_t index) const {
   return code_table_[declared_function_index(module(), index)] != nullptr;
 }
 
+bool NativeModule::HasCodeWithTier(uint32_t index, ExecutionTier tier) const {
+  base::MutexGuard guard(&allocation_mutex_);
+  return code_table_[declared_function_index(module(), index)] != nullptr &&
+         code_table_[declared_function_index(module(), index)]->tier() == tier;
+}
+
 void NativeModule::SetWasmSourceMap(
     std::unique_ptr<WasmModuleSourceMap> source_map) {
   source_map_ = std::move(source_map);
@@ -1142,7 +1141,7 @@ WasmModuleSourceMap* NativeModule::GetWasmSourceMap() const {
 }
 
 WasmCode* NativeModule::CreateEmptyJumpTableInRegion(
-    uint32_t jump_table_size, base::AddressRegion region,
+    int jump_table_size, base::AddressRegion region,
     const WasmCodeAllocator::OptionalLock& allocator_lock) {
   // Only call this if we really need a jump table.
   DCHECK_LT(0, jump_table_size);
@@ -1150,22 +1149,22 @@ WasmCode* NativeModule::CreateEmptyJumpTableInRegion(
       this, jump_table_size, region, allocator_lock);
   DCHECK(!code_space.empty());
   ZapCode(reinterpret_cast<Address>(code_space.begin()), code_space.size());
-  std::unique_ptr<WasmCode> code{new WasmCode{
-      this,                                     // native_module
-      kAnonymousFuncIndex,                      // index
-      code_space,                               // instructions
-      0,                                        // stack_slots
-      0,                                        // tagged_parameter_slots
-      0,                                        // safepoint_table_offset
-      jump_table_size,                          // handler_table_offset
-      jump_table_size,                          // constant_pool_offset
-      jump_table_size,                          // code_comments_offset
-      jump_table_size,                          // unpadded_binary_size
-      OwnedVector<ProtectedInstructionData>{},  // protected_instructions
-      OwnedVector<const uint8_t>{},             // reloc_info
-      OwnedVector<const uint8_t>{},             // source_pos
-      WasmCode::kJumpTable,                     // kind
-      ExecutionTier::kNone}};                   // tier
+  std::unique_ptr<WasmCode> code{
+      new WasmCode{this,                    // native_module
+                   kAnonymousFuncIndex,     // index
+                   code_space,              // instructions
+                   0,                       // stack_slots
+                   0,                       // tagged_parameter_slots
+                   0,                       // safepoint_table_offset
+                   jump_table_size,         // handler_table_offset
+                   jump_table_size,         // constant_pool_offset
+                   jump_table_size,         // code_comments_offset
+                   jump_table_size,         // unpadded_binary_size
+                   {},                      // protected_instructions
+                   {},                      // reloc_info
+                   {},                      // source_pos
+                   WasmCode::kJumpTable,    // kind
+                   ExecutionTier::kNone}};  // tier
   return PublishCode(std::move(code));
 }
 
@@ -1238,12 +1237,10 @@ void NativeModule::AddCodeSpace(
   WasmCode* jump_table = nullptr;
   WasmCode* far_jump_table = nullptr;
   const uint32_t num_wasm_functions = module_->num_declared_functions;
-  const bool has_functions = num_wasm_functions > 0;
   const bool is_first_code_space = code_space_data_.empty();
-  // TODO(clemensb): Avoid additional jump table if the code space is close
-  // enough to another existing code space.
-  const bool needs_jump_table =
-      has_functions && (kNeedsFarJumpsBetweenCodeSpaces || is_first_code_space);
+  // We always need a far jump table, because it contains the runtime stubs.
+  const bool needs_far_jump_table = !FindJumpTablesForRegion(region).is_valid();
+  const bool needs_jump_table = num_wasm_functions > 0 && needs_far_jump_table;
 
   if (needs_jump_table) {
     jump_table = CreateEmptyJumpTableInRegion(
@@ -1252,32 +1249,39 @@ void NativeModule::AddCodeSpace(
     CHECK(region.contains(jump_table->instruction_start()));
   }
 
-  // Always allocate a far jump table, because it contains the runtime stubs.
-  int num_function_slots = NumWasmFunctionsInFarJumpTable(num_wasm_functions);
-  far_jump_table = CreateEmptyJumpTableInRegion(
-      JumpTableAssembler::SizeForNumberOfFarJumpSlots(
-          WasmCode::kRuntimeStubCount,
-          NumWasmFunctionsInFarJumpTable(num_function_slots)),
-      region, allocator_lock);
-  CHECK(region.contains(far_jump_table->instruction_start()));
-  EmbeddedData embedded_data = EmbeddedData::FromBlob();
+  if (needs_far_jump_table) {
+    int num_function_slots = NumWasmFunctionsInFarJumpTable(num_wasm_functions);
+    far_jump_table = CreateEmptyJumpTableInRegion(
+        JumpTableAssembler::SizeForNumberOfFarJumpSlots(
+            WasmCode::kRuntimeStubCount,
+            NumWasmFunctionsInFarJumpTable(num_function_slots)),
+        region, allocator_lock);
+    CHECK(region.contains(far_jump_table->instruction_start()));
+    EmbeddedData embedded_data = EmbeddedData::FromBlob();
 #define RUNTIME_STUB(Name) Builtins::k##Name,
 #define RUNTIME_STUB_TRAP(Name) RUNTIME_STUB(ThrowWasm##Name)
-  Builtins::Name stub_names[WasmCode::kRuntimeStubCount] = {
-      WASM_RUNTIME_STUB_LIST(RUNTIME_STUB, RUNTIME_STUB_TRAP)};
+    Builtins::Name stub_names[WasmCode::kRuntimeStubCount] = {
+        WASM_RUNTIME_STUB_LIST(RUNTIME_STUB, RUNTIME_STUB_TRAP)};
 #undef RUNTIME_STUB
 #undef RUNTIME_STUB_TRAP
-  Address builtin_addresses[WasmCode::kRuntimeStubCount];
-  for (int i = 0; i < WasmCode::kRuntimeStubCount; ++i) {
-    Builtins::Name builtin = stub_names[i];
-    CHECK(embedded_data.ContainsBuiltin(builtin));
-    builtin_addresses[i] = embedded_data.InstructionStartOfBuiltin(builtin);
+    Address builtin_addresses[WasmCode::kRuntimeStubCount];
+    for (int i = 0; i < WasmCode::kRuntimeStubCount; ++i) {
+      Builtins::Name builtin = stub_names[i];
+      CHECK(embedded_data.ContainsBuiltin(builtin));
+      builtin_addresses[i] = embedded_data.InstructionStartOfBuiltin(builtin);
+    }
+    JumpTableAssembler::GenerateFarJumpTable(
+        far_jump_table->instruction_start(), builtin_addresses,
+        WasmCode::kRuntimeStubCount, num_function_slots);
   }
-  JumpTableAssembler::GenerateFarJumpTable(
-      far_jump_table->instruction_start(), builtin_addresses,
-      WasmCode::kRuntimeStubCount, num_function_slots);
 
-  if (is_first_code_space) main_jump_table_ = jump_table;
+  if (is_first_code_space) {
+    // This can be updated and accessed without locks, since the addition of the
+    // first code space happens during initialization of the {NativeModule},
+    // where no concurrent accesses are possible.
+    main_jump_table_ = jump_table;
+    main_far_jump_table_ = far_jump_table;
+  }
 
   base::MutexGuard guard(&allocation_mutex_);
   code_space_data_.push_back(CodeSpaceData{region, jump_table, far_jump_table});
@@ -1354,32 +1358,60 @@ Address NativeModule::GetCallTargetForFunction(uint32_t func_index) const {
   return main_jump_table_->instruction_start() + slot_offset;
 }
 
-NativeModule::JumpTablesRef NativeModule::FindJumpTablesForCode(
-    Address code_addr) const {
+NativeModule::JumpTablesRef NativeModule::FindJumpTablesForRegion(
+    base::AddressRegion code_region) const {
+  auto jump_table_usable = [code_region](const WasmCode* jump_table) {
+    Address table_start = jump_table->instruction_start();
+    Address table_end = table_start + jump_table->instructions().size();
+    // Compute the maximum distance from anywhere in the code region to anywhere
+    // in the jump table, avoiding any underflow.
+    size_t max_distance = std::max(
+        code_region.end() > table_start ? code_region.end() - table_start : 0,
+        table_end > code_region.begin() ? table_end - code_region.begin() : 0);
+    return max_distance < kMaxWasmCodeSpaceSize;
+  };
+
+  // Fast path: Try to use {main_jump_table_} and {main_far_jump_table_}.
+  // Access to these fields is possible without locking, since these fields are
+  // initialized on construction of the {NativeModule}.
+  if (main_far_jump_table_ && jump_table_usable(main_far_jump_table_) &&
+      (main_jump_table_ == nullptr || jump_table_usable(main_jump_table_))) {
+    return {
+        main_jump_table_ ? main_jump_table_->instruction_start() : kNullAddress,
+        main_far_jump_table_->instruction_start()};
+  }
+
+  // Otherwise, take the mutex and look for another suitable jump table.
   base::MutexGuard guard(&allocation_mutex_);
   for (auto& code_space_data : code_space_data_) {
-    const bool jump_table_reachable =
-        !kNeedsFarJumpsBetweenCodeSpaces ||
-        code_space_data.region.contains(code_addr);
-    if (jump_table_reachable && code_space_data.far_jump_table) {
-      // We might not have a jump table if we have no functions.
-      return {code_space_data.jump_table
-                  ? code_space_data.jump_table->instruction_start()
-                  : kNullAddress,
-              code_space_data.far_jump_table->instruction_start()};
+    DCHECK_IMPLIES(code_space_data.jump_table, code_space_data.far_jump_table);
+    if (!code_space_data.far_jump_table) continue;
+    // Only return these jump tables if they are reachable from the whole
+    // {code_region}.
+    if (kNeedsFarJumpsBetweenCodeSpaces &&
+        (!jump_table_usable(code_space_data.far_jump_table) ||
+         (code_space_data.jump_table &&
+          !jump_table_usable(code_space_data.jump_table)))) {
+      continue;
     }
+    return {code_space_data.jump_table
+                ? code_space_data.jump_table->instruction_start()
+                : kNullAddress,
+            code_space_data.far_jump_table->instruction_start()};
   }
-  FATAL("code_addr is not part of a code space");
+  return {};
 }
 
 Address NativeModule::GetNearCallTargetForFunction(
     uint32_t func_index, const JumpTablesRef& jump_tables) const {
+  DCHECK(jump_tables.is_valid());
   uint32_t slot_offset = GetJumpTableOffset(func_index);
   return jump_tables.jump_table_start + slot_offset;
 }
 
 Address NativeModule::GetNearRuntimeStubEntry(
     WasmCode::RuntimeStubId index, const JumpTablesRef& jump_tables) const {
+  DCHECK(jump_tables.is_valid());
   auto offset = JumpTableAssembler::FarJumpSlotIndexToOffset(index);
   return jump_tables.far_jump_table_start + offset;
 }
@@ -1657,8 +1689,7 @@ size_t WasmCodeManager::EstimateNativeModuleMetaDataSize(
 
 std::shared_ptr<NativeModule> WasmCodeManager::NewNativeModule(
     WasmEngine* engine, Isolate* isolate, const WasmFeatures& enabled,
-    size_t code_size_estimate, bool can_request_more,
-    std::shared_ptr<const WasmModule> module) {
+    size_t code_size_estimate, std::shared_ptr<const WasmModule> module) {
   DCHECK_EQ(this, isolate->wasm_engine()->code_manager());
   if (total_committed_code_space_.load() >
       critical_committed_code_space_.load()) {
@@ -1672,9 +1703,7 @@ std::shared_ptr<NativeModule> WasmCodeManager::NewNativeModule(
 
   // If we cannot add code space later, reserve enough address space up front.
   size_t code_vmem_size =
-      can_request_more ? ReservationSize(code_size_estimate,
-                                         module->num_declared_functions, 0)
-                       : kMaxWasmCodeSpaceSize;
+      ReservationSize(code_size_estimate, module->num_declared_functions, 0);
 
   // The '--wasm-max-code-space-reservation' testing flag can be used to reduce
   // the maximum size of the initial code space reservation (in MB).
@@ -1705,8 +1734,8 @@ std::shared_ptr<NativeModule> WasmCodeManager::NewNativeModule(
   size_t size = code_space.size();
   Address end = code_space.end();
   std::shared_ptr<NativeModule> ret;
-  new NativeModule(engine, enabled, can_request_more, std::move(code_space),
-                   std::move(module), isolate->async_counters(), &ret);
+  new NativeModule(engine, enabled, std::move(code_space), std::move(module),
+                   isolate->async_counters(), &ret);
   // The constructor initialized the shared_ptr.
   DCHECK_NOT_NULL(ret);
   TRACE_HEAP("New NativeModule %p: Mem: %" PRIuPTR ",+%zu\n", ret.get(), start,
@@ -1740,8 +1769,6 @@ void NativeModule::SampleCodeSize(
       if (generated_size >= 2 * MB && module()->origin == kWasmOrigin) {
         size_t freed_size = code_allocator_.freed_code_size();
         DCHECK_LE(freed_size, generated_size);
-        int total_freed_mb = static_cast<int>(freed_size / MB);
-        counters->wasm_module_freed_code_size_mb()->AddSample(total_freed_mb);
         int freed_percent = static_cast<int>(100 * freed_size / generated_size);
         counters->wasm_module_freed_code_size_percent()->AddSample(
             freed_percent);
@@ -1768,8 +1795,7 @@ std::vector<WasmCode*> NativeModule::AddCompiledCode(
   Vector<byte> code_space =
       code_allocator_.AllocateForCode(this, total_code_space);
   // Lookup the jump tables to use once, then use for all code objects.
-  auto jump_tables_ref =
-      FindJumpTablesForCode(reinterpret_cast<Address>(code_space.begin()));
+  auto jump_tables = FindJumpTablesForRegion(base::AddressRegionOf(code_space));
 
   std::vector<std::unique_ptr<WasmCode>> generated_code;
   generated_code.reserve(results.size());
@@ -1782,9 +1808,10 @@ std::vector<WasmCode*> NativeModule::AddCompiledCode(
     code_space += code_size;
     generated_code.emplace_back(AddCodeWithCodeSpace(
         result.func_index, result.code_desc, result.frame_slot_count,
-        result.tagged_parameter_slots, std::move(result.protected_instructions),
-        std::move(result.source_positions), GetCodeKind(result),
-        result.result_tier, this_code_space, jump_tables_ref));
+        result.tagged_parameter_slots,
+        result.protected_instructions_data.as_vector(),
+        result.source_positions.as_vector(), GetCodeKind(result),
+        result.result_tier, this_code_space, jump_tables));
   }
   DCHECK_EQ(0, code_space.size());
 
@@ -1806,18 +1833,37 @@ bool NativeModule::IsRedirectedToInterpreter(uint32_t func_index) {
   return has_interpreter_redirection(func_index);
 }
 
+bool NativeModule::SetTieredDown() {
+  // Do not tier down asm.js.
+  if (module()->origin != kWasmOrigin) return false;
+
+  base::MutexGuard lock(&allocation_mutex_);
+  if (tier_down_) return true;
+  tier_down_ = true;
+  return false;
+}
+
+bool NativeModule::IsTieredDown() {
+  base::MutexGuard lock(&allocation_mutex_);
+  return tier_down_;
+}
+
 void NativeModule::TierDown(Isolate* isolate) {
-  // Set the flag.
-  {
-    base::MutexGuard lock(&allocation_mutex_);
-    tier_down_ = true;
-  }
+  // Do not tier down asm.js.
+  if (module()->origin != kWasmOrigin) return;
+
+  // Set the flag. Return if it is already set.
+  if (SetTieredDown()) return;
+
   // Tier down all functions.
   isolate->wasm_engine()->RecompileAllFunctions(isolate, this,
                                                 ExecutionTier::kLiftoff);
 }
 
 void NativeModule::TierUp(Isolate* isolate) {
+  // Do not tier up asm.js.
+  if (module()->origin != kWasmOrigin) return;
+
   // Set the flag.
   {
     base::MutexGuard lock(&allocation_mutex_);
@@ -1825,21 +1871,18 @@ void NativeModule::TierUp(Isolate* isolate) {
   }
 
   // Tier up all functions.
-  // TODO(duongn): parallelize this eventually.
-  for (uint32_t index = module_->num_imported_functions;
-       index < num_functions(); index++) {
-    isolate->wasm_engine()->CompileFunction(isolate, this, index,
-                                            ExecutionTier::kTurbofan);
-    DCHECK(!compilation_state()->failed());
-  }
+  isolate->wasm_engine()->RecompileAllFunctions(isolate, this,
+                                                ExecutionTier::kTurbofan);
 }
 
 void NativeModule::FreeCode(Vector<WasmCode* const> codes) {
   // Free the code space.
   code_allocator_.FreeCode(codes);
 
-  // Free the {WasmCode} objects. This will also unregister trap handler data.
   base::MutexGuard guard(&allocation_mutex_);
+  // Remove debug side tables for all removed code objects.
+  if (debug_info_) debug_info_->RemoveDebugSideTables(codes);
+  // Free the {WasmCode} objects. This will also unregister trap handler data.
   for (WasmCode* code : codes) {
     DCHECK_EQ(1, owned_code_.count(code->instruction_start()));
     owned_code_.erase(code->instruction_start());
diff --git a/deps/v8/src/wasm/wasm-code-manager.h b/deps/v8/src/wasm/wasm-code-manager.h
index 513426785f..4b176f3ba6 100644
--- a/deps/v8/src/wasm/wasm-code-manager.h
+++ b/deps/v8/src/wasm/wasm-code-manager.h
@@ -48,10 +48,15 @@ struct WasmModule;
 #define WASM_RUNTIME_STUB_LIST(V, VTRAP) \
   FOREACH_WASM_TRAPREASON(VTRAP)         \
   V(WasmCompileLazy)                     \
+  V(WasmDebugBreak)                      \
   V(WasmAtomicNotify)                    \
-  V(WasmI32AtomicWait)                   \
-  V(WasmI64AtomicWait)                   \
+  V(WasmI32AtomicWait32)                 \
+  V(WasmI32AtomicWait64)                 \
+  V(WasmI64AtomicWait32)                 \
+  V(WasmI64AtomicWait64)                 \
   V(WasmMemoryGrow)                      \
+  V(WasmTableInit)                       \
+  V(WasmTableCopy)                       \
   V(WasmTableGet)                        \
   V(WasmTableSet)                        \
   V(WasmStackGuard)                      \
@@ -124,13 +129,17 @@ class V8_EXPORT_PRIVATE WasmCode final {
   Address instruction_start() const {
     return reinterpret_cast<Address>(instructions_.begin());
   }
-  Vector<const byte> reloc_info() const { return reloc_info_.as_vector(); }
+  Vector<const byte> reloc_info() const {
+    return {protected_instructions_data().end(),
+            static_cast<size_t>(reloc_info_size_)};
+  }
   Vector<const byte> source_positions() const {
-    return source_position_table_.as_vector();
+    return {reloc_info().end(), static_cast<size_t>(source_positions_size_)};
   }
 
+  // TODO(clemensb): Make this return int.
   uint32_t index() const {
-    DCHECK(!IsAnonymous());
+    DCHECK_LE(0, index_);
     return index_;
   }
   // Anonymous functions are functions that don't carry an index.
@@ -140,25 +149,31 @@ class V8_EXPORT_PRIVATE WasmCode final {
   ExecutionTier tier() const { return tier_; }
   Address constant_pool() const;
   Address handler_table() const;
-  uint32_t handler_table_size() const;
+  int handler_table_size() const;
   Address code_comments() const;
-  uint32_t code_comments_size() const;
-  size_t constant_pool_offset() const { return constant_pool_offset_; }
-  size_t safepoint_table_offset() const { return safepoint_table_offset_; }
-  size_t handler_table_offset() const { return handler_table_offset_; }
-  size_t code_comments_offset() const { return code_comments_offset_; }
-  size_t unpadded_binary_size() const { return unpadded_binary_size_; }
-  uint32_t stack_slots() const { return stack_slots_; }
-  uint32_t tagged_parameter_slots() const { return tagged_parameter_slots_; }
+  int code_comments_size() const;
+  int constant_pool_offset() const { return constant_pool_offset_; }
+  int safepoint_table_offset() const { return safepoint_table_offset_; }
+  int handler_table_offset() const { return handler_table_offset_; }
+  int code_comments_offset() const { return code_comments_offset_; }
+  int unpadded_binary_size() const { return unpadded_binary_size_; }
+  int stack_slots() const { return stack_slots_; }
+  int tagged_parameter_slots() const { return tagged_parameter_slots_; }
   bool is_liftoff() const { return tier_ == ExecutionTier::kLiftoff; }
   bool contains(Address pc) const {
     return reinterpret_cast<Address>(instructions_.begin()) <= pc &&
            pc < reinterpret_cast<Address>(instructions_.end());
   }
 
-  Vector<trap_handler::ProtectedInstructionData> protected_instructions()
+  Vector<const uint8_t> protected_instructions_data() const {
+    return {meta_data_.get(),
+            static_cast<size_t>(protected_instructions_size_)};
+  }
+
+  Vector<const trap_handler::ProtectedInstructionData> protected_instructions()
       const {
-    return protected_instructions_.as_vector();
+    return Vector<const trap_handler::ProtectedInstructionData>::cast(
+        protected_instructions_data());
   }
 
   void Validate() const;
@@ -206,25 +221,25 @@ class V8_EXPORT_PRIVATE WasmCode final {
 
   enum FlushICache : bool { kFlushICache = true, kNoFlushICache = false };
 
-  STATIC_ASSERT(kAnonymousFuncIndex > kV8MaxWasmFunctions);
-
  private:
   friend class NativeModule;
 
-  WasmCode(NativeModule* native_module, uint32_t index,
-           Vector<byte> instructions, uint32_t stack_slots,
-           uint32_t tagged_parameter_slots, size_t safepoint_table_offset,
-           size_t handler_table_offset, size_t constant_pool_offset,
-           size_t code_comments_offset, size_t unpadded_binary_size,
-           OwnedVector<trap_handler::ProtectedInstructionData>
-               protected_instructions,
-           OwnedVector<const byte> reloc_info,
-           OwnedVector<const byte> source_position_table, Kind kind,
+  WasmCode(NativeModule* native_module, int index, Vector<byte> instructions,
+           int stack_slots, int tagged_parameter_slots,
+           int safepoint_table_offset, int handler_table_offset,
+           int constant_pool_offset, int code_comments_offset,
+           int unpadded_binary_size,
+           Vector<const byte> protected_instructions_data,
+           Vector<const byte> reloc_info,
+           Vector<const byte> source_position_table, Kind kind,
            ExecutionTier tier)
       : instructions_(instructions),
-        reloc_info_(std::move(reloc_info)),
-        source_position_table_(std::move(source_position_table)),
         native_module_(native_module),
+        meta_data_(ConcatenateBytes(
+            {protected_instructions_data, reloc_info, source_position_table})),
+        reloc_info_size_(reloc_info.length()),
+        source_positions_size_(source_position_table.length()),
+        protected_instructions_size_(protected_instructions_data.length()),
         index_(index),
         kind_(kind),
         constant_pool_offset_(constant_pool_offset),
@@ -234,7 +249,6 @@ class V8_EXPORT_PRIVATE WasmCode final {
         handler_table_offset_(handler_table_offset),
         code_comments_offset_(code_comments_offset),
         unpadded_binary_size_(unpadded_binary_size),
-        protected_instructions_(std::move(protected_instructions)),
         tier_(tier) {
     DCHECK_LE(safepoint_table_offset, unpadded_binary_size);
     DCHECK_LE(handler_table_offset, unpadded_binary_size);
@@ -242,6 +256,9 @@ class V8_EXPORT_PRIVATE WasmCode final {
     DCHECK_LE(constant_pool_offset, unpadded_binary_size);
   }
 
+  std::unique_ptr<const byte[]> ConcatenateBytes(
+      std::initializer_list<Vector<const byte>>);
+
   // Code objects that have been registered with the global trap handler within
   // this process, will have a {trap_handler_index} associated with them.
   int trap_handler_index() const {
@@ -263,25 +280,30 @@ class V8_EXPORT_PRIVATE WasmCode final {
   V8_NOINLINE bool DecRefOnPotentiallyDeadCode();
 
   Vector<byte> instructions_;
-  OwnedVector<const byte> reloc_info_;
-  OwnedVector<const byte> source_position_table_;
   NativeModule* native_module_ = nullptr;
-  uint32_t index_;
+  // {meta_data_} contains several byte vectors concatenated into one:
+  //  - protected instructions data of size {protected_instructions_size_}
+  //  - relocation info of size {reloc_info_size_}
+  //  - source positions of size {source_positions_size_}
+  // Note that the protected instructions come first to ensure alignment.
+  std::unique_ptr<const byte[]> meta_data_;
+  const int reloc_info_size_;
+  const int source_positions_size_;
+  const int protected_instructions_size_;
+  int index_;
   Kind kind_;
-  size_t constant_pool_offset_ = 0;
-  uint32_t stack_slots_ = 0;
+  int constant_pool_offset_ = 0;
+  int stack_slots_ = 0;
   // Number of tagged parameters passed to this function via the stack. This
   // value is used by the stack walker (e.g. GC) to find references.
-  uint32_t tagged_parameter_slots_ = 0;
-  // we care about safepoint data for wasm-to-js functions,
-  // since there may be stack/register tagged values for large number
-  // conversions.
-  size_t safepoint_table_offset_ = 0;
-  size_t handler_table_offset_ = 0;
-  size_t code_comments_offset_ = 0;
-  size_t unpadded_binary_size_ = 0;
+  int tagged_parameter_slots_ = 0;
+  // We care about safepoint data for wasm-to-js functions, since there may be
+  // stack/register tagged values for large number conversions.
+  int safepoint_table_offset_ = 0;
+  int handler_table_offset_ = 0;
+  int code_comments_offset_ = 0;
+  int unpadded_binary_size_ = 0;
   int trap_handler_index_ = -1;
-  OwnedVector<trap_handler::ProtectedInstructionData> protected_instructions_;
   ExecutionTier tier_;
 
   // WasmCode is ref counted. Counters are held by:
@@ -299,6 +321,12 @@ class V8_EXPORT_PRIVATE WasmCode final {
   DISALLOW_COPY_AND_ASSIGN(WasmCode);
 };
 
+// Check that {WasmCode} objects are sufficiently small. We create many of them,
+// often for rather small functions.
+// Increase the limit if needed, but first check if the size increase is
+// justified.
+STATIC_ASSERT(sizeof(WasmCode) <= 96);
+
 WasmCode::Kind GetCodeKind(const WasmCompilationResult& result);
 
 // Return a textual description of the kind.
@@ -327,7 +355,6 @@ class WasmCodeAllocator {
   };
 
   WasmCodeAllocator(WasmCodeManager*, VirtualMemory code_space,
-                    bool can_request_more,
                     std::shared_ptr<Counters> async_counters);
   ~WasmCodeAllocator();
 
@@ -391,10 +418,6 @@ class WasmCodeAllocator {
 
   bool is_executable_ = false;
 
-  // TODO(clemensb): Remove this field once multiple code spaces are supported
-  // everywhere.
-  const bool can_request_more_memory_;
-
   std::shared_ptr<Counters> async_counters_;
 };
 
@@ -409,13 +432,11 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // {AddCode} is thread safe w.r.t. other calls to {AddCode} or methods adding
   // code below, i.e. it can be called concurrently from background threads.
   // The returned code still needs to be published via {PublishCode}.
-  std::unique_ptr<WasmCode> AddCode(
-      uint32_t index, const CodeDesc& desc, uint32_t stack_slots,
-      uint32_t tagged_parameter_slots,
-      OwnedVector<trap_handler::ProtectedInstructionData>
-          protected_instructions,
-      OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
-      ExecutionTier tier);
+  std::unique_ptr<WasmCode> AddCode(int index, const CodeDesc& desc,
+                                    int stack_slots, int tagged_parameter_slots,
+                                    Vector<const byte> protected_instructions,
+                                    Vector<const byte> source_position_table,
+                                    WasmCode::Kind kind, ExecutionTier tier);
 
   // {PublishCode} makes the code available to the system by entering it into
   // the code table and patching the jump table. It returns a raw pointer to the
@@ -425,15 +446,13 @@ class V8_EXPORT_PRIVATE NativeModule final {
   WasmCode* PublishCodeLocked(std::unique_ptr<WasmCode>);
 
   WasmCode* AddDeserializedCode(
-      uint32_t index, Vector<const byte> instructions, uint32_t stack_slots,
-      uint32_t tagged_parameter_slots, size_t safepoint_table_offset,
-      size_t handler_table_offset, size_t constant_pool_offset,
-      size_t code_comments_offset, size_t unpadded_binary_size,
-      OwnedVector<trap_handler::ProtectedInstructionData>
-          protected_instructions,
-      OwnedVector<const byte> reloc_info,
-      OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
-      ExecutionTier tier);
+      int index, Vector<const byte> instructions, int stack_slots,
+      int tagged_parameter_slots, int safepoint_table_offset,
+      int handler_table_offset, int constant_pool_offset,
+      int code_comments_offset, int unpadded_binary_size,
+      Vector<const byte> protected_instructions_data,
+      Vector<const byte> reloc_info, Vector<const byte> source_position_table,
+      WasmCode::Kind kind, ExecutionTier tier);
 
   // Adds anonymous code for testing purposes.
   WasmCode* AddCodeForTesting(Handle<Code> code);
@@ -449,6 +468,7 @@ class V8_EXPORT_PRIVATE NativeModule final {
 
   WasmCode* GetCode(uint32_t index) const;
   bool HasCode(uint32_t index) const;
+  bool HasCodeWithTier(uint32_t index, ExecutionTier tier) const;
 
   void SetWasmSourceMap(std::unique_ptr<WasmModuleSourceMap> source_map);
   WasmModuleSourceMap* GetWasmSourceMap() const;
@@ -465,23 +485,25 @@ class V8_EXPORT_PRIVATE NativeModule final {
   Address GetCallTargetForFunction(uint32_t func_index) const;
 
   struct JumpTablesRef {
-    const Address jump_table_start;
-    const Address far_jump_table_start;
+    const Address jump_table_start = kNullAddress;
+    const Address far_jump_table_start = kNullAddress;
+
+    bool is_valid() const { return far_jump_table_start != kNullAddress; }
   };
 
-  // Finds the jump tables that should be used for the code at {code_addr}. This
+  // Finds the jump tables that should be used for given code region. This
   // information is then passed to {GetNearCallTargetForFunction} and
   // {GetNearRuntimeStubEntry} to avoid the overhead of looking this information
-  // up there.
-  JumpTablesRef FindJumpTablesForCode(Address code_addr) const;
+  // up there. Return an empty struct if no suitable jump tables exist.
+  JumpTablesRef FindJumpTablesForRegion(base::AddressRegion) const;
 
   // Similarly to {GetCallTargetForFunction}, but uses the jump table previously
-  // looked up via {FindJumpTablesForCode}.
+  // looked up via {FindJumpTablesForRegion}.
   Address GetNearCallTargetForFunction(uint32_t func_index,
                                        const JumpTablesRef&) const;
 
   // Get a runtime stub entry (which is a far jump table slot) in the jump table
-  // previously looked up via {FindJumpTablesForCode}.
+  // previously looked up via {FindJumpTablesForRegion}.
   Address GetNearRuntimeStubEntry(WasmCode::RuntimeStubId index,
                                   const JumpTablesRef&) const;
 
@@ -552,6 +574,10 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // by publishing an entry stub with the {Kind::kInterpreterEntry} code kind.
   bool IsRedirectedToInterpreter(uint32_t func_index);
 
+  // Set {tier_down_} flag. Return previous state.
+  bool SetTieredDown();
+  bool IsTieredDown();
+
   // Sets the flag, triggers recompilation of all methods to tier down or up,
   // waits for that to complete.
   void TierDown(Isolate* isolate);
@@ -584,22 +610,21 @@ class V8_EXPORT_PRIVATE NativeModule final {
 
   // Private constructor, called via {WasmCodeManager::NewNativeModule()}.
   NativeModule(WasmEngine* engine, const WasmFeatures& enabled_features,
-               bool can_request_more, VirtualMemory code_space,
+               VirtualMemory code_space,
                std::shared_ptr<const WasmModule> module,
                std::shared_ptr<Counters> async_counters,
                std::shared_ptr<NativeModule>* shared_this);
 
   std::unique_ptr<WasmCode> AddCodeWithCodeSpace(
-      uint32_t index, const CodeDesc& desc, uint32_t stack_slots,
-      uint32_t tagged_parameter_slots,
-      OwnedVector<trap_handler::ProtectedInstructionData>
-          protected_instructions,
-      OwnedVector<const byte> source_position_table, WasmCode::Kind kind,
+      int index, const CodeDesc& desc, int stack_slots,
+      int tagged_parameter_slots,
+      Vector<const byte> protected_instructions_data,
+      Vector<const byte> source_position_table, WasmCode::Kind kind,
       ExecutionTier tier, Vector<uint8_t> code_space,
       const JumpTablesRef& jump_tables_ref);
 
   WasmCode* CreateEmptyJumpTableInRegion(
-      uint32_t jump_table_size, base::AddressRegion,
+      int jump_table_size, base::AddressRegion,
       const WasmCodeAllocator::OptionalLock&);
 
   // Hold the {allocation_mutex_} when calling one of these methods.
@@ -656,10 +681,14 @@ class V8_EXPORT_PRIVATE NativeModule final {
   // {WireBytesStorage}, held by background compile tasks.
   std::shared_ptr<OwnedVector<const uint8_t>> wire_bytes_;
 
-  // Jump table used by external calls (from JS). Wasm calls use one of the jump
-  // tables stored in {code_space_data_}.
+  // The first allocated jump table. Always used by external calls (from JS).
+  // Wasm calls might use one of the other jump tables stored in
+  // {code_space_data_}.
   WasmCode* main_jump_table_ = nullptr;
 
+  // The first allocated far jump table.
+  WasmCode* main_far_jump_table_ = nullptr;
+
   // Lazy compile stub table, containing entries to jump to the
   // {WasmCompileLazy} builtin, passing the function index.
   WasmCode* lazy_compile_table_ = nullptr;
@@ -757,7 +786,7 @@ class V8_EXPORT_PRIVATE WasmCodeManager final {
   std::shared_ptr<NativeModule> NewNativeModule(
       WasmEngine* engine, Isolate* isolate,
       const WasmFeatures& enabled_features, size_t code_size_estimate,
-      bool can_request_more, std::shared_ptr<const WasmModule> module);
+      std::shared_ptr<const WasmModule> module);
 
   V8_WARN_UNUSED_RESULT VirtualMemory TryAllocate(size_t size,
                                                   void* hint = nullptr);
diff --git a/deps/v8/src/wasm/wasm-constants.h b/deps/v8/src/wasm/wasm-constants.h
index 956322f54a..acce1eef67 100644
--- a/deps/v8/src/wasm/wasm-constants.h
+++ b/deps/v8/src/wasm/wasm-constants.h
@@ -108,7 +108,7 @@ constexpr WasmCodePosition kNoCodePosition = -1;
 
 constexpr uint32_t kExceptionAttribute = 0;
 
-constexpr uint32_t kAnonymousFuncIndex = 0xffffffff;
+constexpr int kAnonymousFuncIndex = -1;
 
 }  // namespace wasm
 }  // namespace internal
diff --git a/deps/v8/src/wasm/wasm-debug-evaluate.cc b/deps/v8/src/wasm/wasm-debug-evaluate.cc
new file mode 100644
index 0000000000..80f0b04e0e
--- /dev/null
+++ b/deps/v8/src/wasm/wasm-debug-evaluate.cc
@@ -0,0 +1,274 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/wasm/wasm-debug-evaluate.h"
+
+#include <algorithm>
+
+#include "src/api/api-inl.h"
+#include "src/codegen/machine-type.h"
+#include "src/wasm/value-type.h"
+#include "src/wasm/wasm-arguments.h"
+#include "src/wasm/wasm-constants.h"
+#include "src/wasm/wasm-module.h"
+#include "src/wasm/wasm-objects.h"
+#include "src/wasm/wasm-result.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+namespace {
+
+static Handle<String> V8String(Isolate* isolate, const char* str) {
+  return isolate->factory()->NewStringFromAsciiChecked(str);
+}
+
+static bool CheckSignature(ValueType return_type,
+                           std::initializer_list<ValueType> argument_types,
+                           const FunctionSig* sig, ErrorThrower* thrower) {
+  if (sig->return_count() != 1 && return_type != kWasmBottom) {
+    thrower->CompileError("Invalid return type. Got none, expected %s",
+                          return_type.type_name());
+    return false;
+  }
+
+  if (sig->return_count() == 1) {
+    if (sig->GetReturn(0) != return_type) {
+      thrower->CompileError("Invalid return type. Got %s, expected %s",
+                            sig->GetReturn(0).type_name(),
+                            return_type.type_name());
+      return false;
+    }
+  }
+
+  if (sig->parameter_count() != argument_types.size()) {
+    thrower->CompileError("Invalid number of arguments. Expected %zu, got %zu",
+                          sig->parameter_count(), argument_types.size());
+    return false;
+  }
+  size_t p = 0;
+  for (ValueType argument_type : argument_types) {
+    if (sig->GetParam(p) != argument_type) {
+      thrower->CompileError(
+          "Invalid argument type for argument %zu. Got %s, expected %s", p,
+          sig->GetParam(p).type_name(), argument_type.type_name());
+      return false;
+    }
+    ++p;
+  }
+  return true;
+}
+
+static bool CheckRangeOutOfBounds(uint32_t offset, uint32_t size,
+                                  size_t allocation_size,
+                                  wasm::ErrorThrower* thrower) {
+  if (size > std::numeric_limits<uint32_t>::max() - offset) {
+    thrower->RuntimeError("Overflowing memory range\n");
+    return true;
+  }
+  if (offset + size > allocation_size) {
+    thrower->RuntimeError("Illegal access to out-of-bounds memory");
+    return true;
+  }
+  return false;
+}
+
+class DebugEvaluatorProxy {
+ public:
+  explicit DebugEvaluatorProxy(Isolate* isolate) : isolate_(isolate) {}
+
+  static void GetMemoryTrampoline(
+      const v8::FunctionCallbackInfo<v8::Value>& args) {
+    DebugEvaluatorProxy& proxy = GetProxy(args);
+
+    uint32_t offset = proxy.GetArgAsUInt32(args, 0);
+    uint32_t size = proxy.GetArgAsUInt32(args, 1);
+    uint32_t result = proxy.GetArgAsUInt32(args, 2);
+
+    proxy.GetMemory(offset, size, result);
+  }
+
+  void GetMemory(uint32_t offset, uint32_t size, uint32_t result) {
+    wasm::ScheduledErrorThrower thrower(isolate_, "debug evaluate proxy");
+    // Check all overflows.
+    if (CheckRangeOutOfBounds(result, size, debuggee_->memory_size(),
+                              &thrower) ||
+        CheckRangeOutOfBounds(offset, size, evaluator_->memory_size(),
+                              &thrower)) {
+      return;
+    }
+
+    std::memcpy(&evaluator_->memory_start()[result],
+                &debuggee_->memory_start()[offset], size);
+  }
+
+  template <typename CallableT>
+  Handle<JSReceiver> WrapAsV8Function(CallableT callback) {
+    v8::Isolate* api_isolate = reinterpret_cast<v8::Isolate*>(isolate_);
+    v8::Local<v8::Context> context = api_isolate->GetCurrentContext();
+    std::string data;
+    v8::Local<v8::Function> func =
+        v8::Function::New(context, callback,
+                          v8::External::New(api_isolate, this))
+            .ToLocalChecked();
+
+    return Utils::OpenHandle(*func);
+  }
+
+  Handle<JSObject> CreateImports() {
+    Handle<JSObject> imports_obj =
+        isolate_->factory()->NewJSObject(isolate_->object_function());
+    Handle<JSObject> import_module_obj =
+        isolate_->factory()->NewJSObject(isolate_->object_function());
+    Object::SetProperty(isolate_, imports_obj,
+                        isolate_->factory()->empty_string(), import_module_obj)
+        .Assert();
+
+    Object::SetProperty(
+        isolate_, import_module_obj, V8String(isolate_, "__getMemory"),
+        WrapAsV8Function(DebugEvaluatorProxy::GetMemoryTrampoline))
+        .Assert();
+    return imports_obj;
+  }
+
+  void SetInstances(Handle<WasmInstanceObject> evaluator,
+                    Handle<WasmInstanceObject> debuggee) {
+    evaluator_ = evaluator;
+    debuggee_ = debuggee;
+  }
+
+ private:
+  uint32_t GetArgAsUInt32(const v8::FunctionCallbackInfo<v8::Value>& args,
+                          int index) {
+    // No type/range checks needed on his because this is only called for {args}
+    // where we have performed a signature check via {VerifyEvaluatorInterface}
+    double number = Utils::OpenHandle(*args[index])->Number();
+    return static_cast<uint32_t>(number);
+  }
+
+  static DebugEvaluatorProxy& GetProxy(
+      const v8::FunctionCallbackInfo<v8::Value>& args) {
+    return *reinterpret_cast<DebugEvaluatorProxy*>(
+        args.Data().As<v8::External>()->Value());
+  }
+
+  Isolate* isolate_;
+  Handle<WasmInstanceObject> evaluator_;
+  Handle<WasmInstanceObject> debuggee_;
+};
+
+static bool VerifyEvaluatorInterface(const WasmModule* raw_module,
+                                     const ModuleWireBytes& bytes,
+                                     ErrorThrower* thrower) {
+  for (const WasmFunction& F : raw_module->functions) {
+    WireBytesRef name_ref = raw_module->function_names.Lookup(
+        bytes, F.func_index, VectorOf(raw_module->export_table));
+    std::string name(bytes.start() + name_ref.offset(),
+                     bytes.start() + name_ref.end_offset());
+    if (F.exported && name == "wasm_format") {
+      if (!CheckSignature(kWasmI32, {}, F.sig, thrower)) return false;
+    } else if (F.imported) {
+      if (name == "__getMemory") {
+        if (!CheckSignature(kWasmBottom, {kWasmI32, kWasmI32, kWasmI32}, F.sig,
+                            thrower)) {
+          return false;
+        }
+      }
+    }
+  }
+  return true;
+}
+
+}  // namespace
+
+Maybe<std::string> DebugEvaluateImpl(
+    Vector<const byte> snippet, Handle<WasmInstanceObject> debuggee_instance,
+    WasmInterpreter::FramePtr frame) {
+  Isolate* isolate = debuggee_instance->GetIsolate();
+  HandleScope handle_scope(isolate);
+  WasmEngine* engine = isolate->wasm_engine();
+  wasm::ErrorThrower thrower(isolate, "wasm debug evaluate");
+
+  // Create module object.
+  wasm::ModuleWireBytes bytes(snippet);
+  wasm::WasmFeatures features = wasm::WasmFeatures::FromIsolate(isolate);
+  Handle<WasmModuleObject> evaluator_module;
+  if (!engine->SyncCompile(isolate, features, &thrower, bytes)
+           .ToHandle(&evaluator_module)) {
+    return Nothing<std::string>();
+  }
+
+  // Verify interface.
+  const WasmModule* raw_module = evaluator_module->module();
+  if (!VerifyEvaluatorInterface(raw_module, bytes, &thrower)) {
+    return Nothing<std::string>();
+  }
+
+  // Set up imports.
+  DebugEvaluatorProxy proxy(isolate);
+  Handle<JSObject> imports = proxy.CreateImports();
+
+  // Instantiate Module.
+  Handle<WasmInstanceObject> evaluator_instance;
+  if (!engine->SyncInstantiate(isolate, &thrower, evaluator_module, imports, {})
+           .ToHandle(&evaluator_instance)) {
+    return Nothing<std::string>();
+  }
+
+  proxy.SetInstances(evaluator_instance, debuggee_instance);
+
+  Handle<JSObject> exports_obj(evaluator_instance->exports_object(), isolate);
+  Handle<Object> entry_point_obj;
+  bool get_property_success =
+      Object::GetProperty(isolate, exports_obj,
+                          V8String(isolate, "wasm_format"))
+          .ToHandle(&entry_point_obj);
+  if (!get_property_success ||
+      !WasmExportedFunction::IsWasmExportedFunction(*entry_point_obj)) {
+    thrower.LinkError("Missing export: \"wasm_format\"");
+    return Nothing<std::string>();
+  }
+  Handle<WasmExportedFunction> entry_point =
+      Handle<WasmExportedFunction>::cast(entry_point_obj);
+
+  Handle<WasmDebugInfo> debug_info =
+      WasmInstanceObject::GetOrCreateDebugInfo(evaluator_instance);
+  Handle<Code> wasm_entry =
+      WasmDebugInfo::GetCWasmEntry(debug_info, entry_point->sig());
+  CWasmArgumentsPacker packer(4 /* uint32_t return value, no parameters. */);
+  Execution::CallWasm(isolate, wasm_entry, entry_point->GetWasmCallTarget(),
+                      evaluator_instance, packer.argv());
+  if (isolate->has_pending_exception()) return Nothing<std::string>();
+
+  uint32_t offset = packer.Pop<uint32_t>();
+  if (CheckRangeOutOfBounds(offset, 0, evaluator_instance->memory_size(),
+                            &thrower)) {
+    return Nothing<std::string>();
+  }
+
+  // Copy the zero-terminated string result but don't overflow.
+  std::string result;
+  byte* heap = evaluator_instance->memory_start() + offset;
+  for (; offset < evaluator_instance->memory_size(); ++offset, ++heap) {
+    if (*heap == 0) return Just(result);
+    result.push_back(*heap);
+  }
+
+  thrower.RuntimeError("The evaluation returned an invalid result");
+  return Nothing<std::string>();
+}
+
+MaybeHandle<String> DebugEvaluate(Vector<const byte> snippet,
+                                  Handle<WasmInstanceObject> debuggee_instance,
+                                  WasmInterpreter::FramePtr frame) {
+  Maybe<std::string> result =
+      DebugEvaluateImpl(snippet, debuggee_instance, std::move(frame));
+  if (result.IsNothing()) return {};
+  std::string result_str = result.ToChecked();
+  return V8String(debuggee_instance->GetIsolate(), result_str.c_str());
+}
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/src/wasm/wasm-debug-evaluate.h b/deps/v8/src/wasm/wasm-debug-evaluate.h
new file mode 100644
index 0000000000..21543eb97a
--- /dev/null
+++ b/deps/v8/src/wasm/wasm-debug-evaluate.h
@@ -0,0 +1,25 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_WASM_WASM_DEBUG_EVALUATE_H_
+#define V8_WASM_WASM_DEBUG_EVALUATE_H_
+
+#include "src/base/macros.h"
+#include "src/handles/maybe-handles.h"
+#include "src/wasm/wasm-interpreter.h"
+#include "src/wasm/wasm-objects.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+MaybeHandle<String> V8_EXPORT_PRIVATE DebugEvaluate(
+    Vector<const byte> snippet, Handle<WasmInstanceObject> debuggee_instance,
+    WasmInterpreter::FramePtr frame);
+
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_WASM_WASM_DEBUG_EVALUATE_H_
diff --git a/deps/v8/src/wasm/wasm-debug.cc b/deps/v8/src/wasm/wasm-debug.cc
index 230427bed0..10a2e194a7 100644
--- a/deps/v8/src/wasm/wasm-debug.cc
+++ b/deps/v8/src/wasm/wasm-debug.cc
@@ -17,6 +17,7 @@
 #include "src/heap/factory.h"
 #include "src/utils/identity-map.h"
 #include "src/wasm/baseline/liftoff-compiler.h"
+#include "src/wasm/baseline/liftoff-register.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-interpreter.h"
@@ -48,23 +49,23 @@ Handle<String> PrintFToOneByteString(Isolate* isolate, const char* format,
 }
 
 Handle<Object> WasmValueToValueObject(Isolate* isolate, WasmValue value) {
-  switch (value.type()) {
-    case kWasmI32:
+  switch (value.type().kind()) {
+    case ValueType::kI32:
       if (Smi::IsValid(value.to<int32_t>()))
         return handle(Smi::FromInt(value.to<int32_t>()), isolate);
       return PrintFToOneByteString<false>(isolate, "%d", value.to<int32_t>());
-    case kWasmI64: {
+    case ValueType::kI64: {
       int64_t i64 = value.to<int64_t>();
       int32_t i32 = static_cast<int32_t>(i64);
       if (i32 == i64 && Smi::IsValid(i32))
         return handle(Smi::FromIntptr(i32), isolate);
       return PrintFToOneByteString<false>(isolate, "%" PRId64, i64);
     }
-    case kWasmF32:
+    case ValueType::kF32:
       return isolate->factory()->NewNumber(value.to<float>());
-    case kWasmF64:
+    case ValueType::kF64:
       return isolate->factory()->NewNumber(value.to<double>());
-    case kWasmAnyRef:
+    case ValueType::kAnyRef:
       return value.to_anyref();
     default:
       UNIMPLEMENTED();
@@ -164,7 +165,7 @@ class InterpreterHandle {
                Vector<WasmValue> argument_values,
                Vector<WasmValue> return_values) {
     DCHECK_GE(module()->functions.size(), func_index);
-    FunctionSig* sig = module()->functions[func_index].sig;
+    const FunctionSig* sig = module()->functions[func_index].sig;
     DCHECK_EQ(sig->parameter_count(), argument_values.size());
     DCHECK_EQ(sig->return_count(), return_values.size());
 
@@ -189,8 +190,11 @@ class InterpreterHandle {
         case WasmInterpreter::State::TRAPPED: {
           MessageTemplate message_id =
               WasmOpcodes::TrapReasonToMessageId(thread->GetTrapReason());
-          Handle<Object> exception =
+          Handle<JSObject> exception =
               isolate_->factory()->NewWasmRuntimeError(message_id);
+          JSObject::AddProperty(isolate_, exception,
+                                isolate_->factory()->wasm_uncatchable_symbol(),
+                                isolate_->factory()->true_value(), NONE);
           auto result = thread->RaiseException(isolate_, exception);
           if (result == WasmInterpreter::Thread::HANDLED) break;
           // If no local handler was found, we fall-thru to {STOPPED}.
@@ -383,9 +387,8 @@ class InterpreterHandle {
     Handle<JSObject> local_scope_object =
         isolate_->factory()->NewJSObjectWithNullProto();
     // Fill parameters and locals.
-    int num_params = frame->GetParameterCount();
     int num_locals = frame->GetLocalCount();
-    DCHECK_LE(num_params, num_locals);
+    DCHECK_LE(frame->GetParameterCount(), num_locals);
     if (num_locals > 0) {
       Handle<JSObject> locals_obj =
           isolate_->factory()->NewJSObjectWithNullProto();
@@ -400,10 +403,7 @@ class InterpreterHandle {
         if (!GetLocalNameString(isolate, native_module,
                                 frame->function()->func_index, i)
                  .ToHandle(&name)) {
-          // Parameters should come before locals in alphabetical ordering, so
-          // we name them "args" here.
-          const char* label = i < num_params ? "arg#%d" : "local#%d";
-          name = PrintFToOneByteString<true>(isolate_, label, i);
+          name = PrintFToOneByteString<true>(isolate_, "var%d", i);
         }
         WasmValue value = frame->GetLocalValue(i);
         Handle<Object> value_obj = WasmValueToValueObject(isolate_, value);
@@ -439,10 +439,92 @@ class InterpreterHandle {
     return local_scope_object;
   }
 
+  Handle<JSObject> GetStackScopeObject(InterpretedFrame* frame,
+                                       Handle<WasmDebugInfo> debug_info) {
+    // Fill stack values.
+    int stack_count = frame->GetStackHeight();
+    // Use an object without prototype instead of an Array, for nicer displaying
+    // in DevTools. For Arrays, the length field and prototype is displayed,
+    // which does not make too much sense here.
+    Handle<JSObject> stack_scope_obj =
+        isolate_->factory()->NewJSObjectWithNullProto();
+    for (int i = 0; i < stack_count; ++i) {
+      WasmValue value = frame->GetStackValue(i);
+      Handle<Object> value_obj = WasmValueToValueObject(isolate_, value);
+      JSObject::AddDataElement(stack_scope_obj, static_cast<uint32_t>(i),
+                               value_obj, NONE);
+    }
+    return stack_scope_obj;
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(InterpreterHandle);
 };
 
+int FindByteOffset(int pc_offset, WasmCode* wasm_code) {
+  int position = 0;
+  SourcePositionTableIterator iterator(wasm_code->source_positions());
+  for (SourcePositionTableIterator iterator(wasm_code->source_positions());
+       !iterator.done() && iterator.code_offset() < pc_offset;
+       iterator.Advance()) {
+    position = iterator.source_position().ScriptOffset();
+  }
+  return position;
+}
+
+// Generate a sorted and deduplicated list of byte offsets for this function's
+// current positions on the stack.
+std::vector<int> StackFramePositions(int func_index, Isolate* isolate) {
+  std::vector<int> byte_offsets;
+  WasmCodeRefScope code_ref_scope;
+  for (StackTraceFrameIterator it(isolate); !it.done(); it.Advance()) {
+    if (!it.is_wasm()) continue;
+    WasmCompiledFrame* frame = WasmCompiledFrame::cast(it.frame());
+    if (static_cast<int>(frame->function_index()) != func_index) continue;
+    WasmCode* wasm_code = frame->wasm_code();
+    if (!wasm_code->is_liftoff()) continue;
+    int pc_offset =
+        static_cast<int>(frame->pc() - wasm_code->instruction_start());
+    int byte_offset = FindByteOffset(pc_offset, wasm_code);
+    byte_offsets.push_back(byte_offset);
+  }
+  std::sort(byte_offsets.begin(), byte_offsets.end());
+  auto last = std::unique(byte_offsets.begin(), byte_offsets.end());
+  byte_offsets.erase(last, byte_offsets.end());
+  return byte_offsets;
+}
+
+enum ReturnLocation { kAfterBreakpoint, kAfterWasmCall };
+
+Address FindNewPC(WasmCode* wasm_code, int byte_offset,
+                  ReturnLocation return_location) {
+  Vector<const uint8_t> new_pos_table = wasm_code->source_positions();
+
+  DCHECK_LE(0, byte_offset);
+
+  // If {return_location == kAfterBreakpoint} we search for the first code
+  // offset which is marked as instruction (i.e. not the breakpoint).
+  // If {return_location == kAfterWasmCall} we return the last code offset
+  // associated with the byte offset.
+  SourcePositionTableIterator it(new_pos_table);
+  while (!it.done() && it.source_position().ScriptOffset() != byte_offset) {
+    it.Advance();
+  }
+  if (return_location == kAfterBreakpoint) {
+    while (!it.is_statement()) it.Advance();
+    DCHECK_EQ(byte_offset, it.source_position().ScriptOffset());
+    return wasm_code->instruction_start() + it.code_offset();
+  }
+
+  DCHECK_EQ(kAfterWasmCall, return_location);
+  int code_offset;
+  do {
+    code_offset = it.code_offset();
+    it.Advance();
+  } while (!it.done() && it.source_position().ScriptOffset() == byte_offset);
+  return wasm_code->instruction_start() + code_offset;
+}
+
 }  // namespace
 
 Handle<JSObject> GetGlobalScopeObject(Handle<WasmInstanceObject> instance) {
@@ -470,9 +552,13 @@ Handle<JSObject> GetGlobalScopeObject(Handle<WasmInstanceObject> instance) {
     JSObject::AddProperty(isolate, global_scope_object, globals_name,
                           globals_obj, NONE);
 
-    for (size_t i = 0; i < globals.size(); ++i) {
-      const char* label = "global#%d";
-      Handle<String> name = PrintFToOneByteString<true>(isolate, label, i);
+    for (uint32_t i = 0; i < globals.size(); ++i) {
+      Handle<String> name;
+      if (!WasmInstanceObject::GetGlobalNameOrNull(isolate, instance, i)
+               .ToHandle(&name)) {
+        const char* label = "global%d";
+        name = PrintFToOneByteString<true>(isolate, label, i);
+      }
       WasmValue value =
           WasmInstanceObject::GetGlobalValue(instance, globals[i]);
       Handle<Object> value_obj = WasmValueToValueObject(isolate, value);
@@ -488,8 +574,8 @@ class DebugInfoImpl {
   explicit DebugInfoImpl(NativeModule* native_module)
       : native_module_(native_module) {}
 
-  Handle<JSObject> GetLocalScopeObject(Isolate* isolate, Address pc,
-                                       Address fp) {
+  Handle<JSObject> GetLocalScopeObject(Isolate* isolate, Address pc, Address fp,
+                                       Address debug_break_fp) {
     Handle<JSObject> local_scope_object =
         isolate->factory()->NewJSObjectWithNullProto();
 
@@ -499,18 +585,16 @@ class DebugInfoImpl {
     // Only Liftoff code can be inspected.
     if (!code->is_liftoff()) return local_scope_object;
 
-    const WasmModule* module = native_module_->module();
-    const WasmFunction* function = &module->functions[code->index()];
-    DebugSideTable* debug_side_table =
-        GetDebugSideTable(isolate->allocator(), function->func_index);
+    auto* module = native_module_->module();
+    auto* function = &module->functions[code->index()];
+    auto* debug_side_table = GetDebugSideTable(code, isolate->allocator());
     int pc_offset = static_cast<int>(pc - code->instruction_start());
     auto* debug_side_table_entry = debug_side_table->GetEntry(pc_offset);
     DCHECK_NOT_NULL(debug_side_table_entry);
 
     // Fill parameters and locals.
-    int num_params = static_cast<int>(function->sig->parameter_count());
     int num_locals = static_cast<int>(debug_side_table->num_locals());
-    DCHECK_LE(num_params, num_locals);
+    DCHECK_LE(static_cast<int>(function->sig->parameter_count()), num_locals);
     if (num_locals > 0) {
       Handle<JSObject> locals_obj =
           isolate->factory()->NewJSObjectWithNullProto();
@@ -523,14 +607,10 @@ class DebugInfoImpl {
         if (!GetLocalNameString(isolate, native_module_, function->func_index,
                                 i)
                  .ToHandle(&name)) {
-          // Parameters should come before locals in alphabetical ordering, so
-          // we name them "args" here.
-          const char* label = i < num_params ? "arg#%d" : "local#%d";
-          name = PrintFToOneByteString<true>(isolate, label, i);
+          name = PrintFToOneByteString<true>(isolate, "var%d", i);
         }
         WasmValue value =
-            GetValue(debug_side_table_entry, debug_side_table->local_type(i), i,
-                     fp - debug_side_table->local_stack_offset(i));
+            GetValue(debug_side_table_entry, i, fp, debug_break_fp);
         Handle<Object> value_obj = WasmValueToValueObject(isolate, value);
         // {name} can be a string representation of an element index.
         LookupIterator::Key lookup_key{isolate, name};
@@ -545,7 +625,6 @@ class DebugInfoImpl {
     }
 
     // Fill stack values.
-    int stack_count = debug_side_table_entry->stack_height();
     // Use an object without prototype instead of an Array, for nicer displaying
     // in DevTools. For Arrays, the length field and prototype is displayed,
     // which does not make too much sense here.
@@ -554,17 +633,48 @@ class DebugInfoImpl {
         isolate->factory()->InternalizeString(StaticCharVector("stack"));
     JSObject::AddProperty(isolate, local_scope_object, stack_name, stack_obj,
                           NONE);
-    for (int i = 0; i < stack_count; ++i) {
-      ValueType type = debug_side_table_entry->stack_type(i);
-      WasmValue value = GetValue(debug_side_table_entry, type, num_locals + i,
-                                 fp - debug_side_table_entry->stack_offset(i));
+    int value_count = debug_side_table_entry->num_values();
+    for (int i = num_locals; i < value_count; ++i) {
+      WasmValue value = GetValue(debug_side_table_entry, i, fp, debug_break_fp);
       Handle<Object> value_obj = WasmValueToValueObject(isolate, value);
-      JSObject::AddDataElement(stack_obj, static_cast<uint32_t>(i), value_obj,
-                               NONE);
+      JSObject::AddDataElement(stack_obj, static_cast<uint32_t>(i - num_locals),
+                               value_obj, NONE);
     }
     return local_scope_object;
   }
 
+  Handle<JSObject> GetStackScopeObject(Isolate* isolate, Address pc, Address fp,
+                                       Address debug_break_fp) {
+    Handle<JSObject> stack_scope_obj =
+        isolate->factory()->NewJSObjectWithNullProto();
+    wasm::WasmCodeRefScope wasm_code_ref_scope;
+
+    wasm::WasmCode* code =
+        isolate->wasm_engine()->code_manager()->LookupCode(pc);
+    // Only Liftoff code can be inspected.
+    if (!code->is_liftoff()) return stack_scope_obj;
+
+    auto* debug_side_table = GetDebugSideTable(code, isolate->allocator());
+    int pc_offset = static_cast<int>(pc - code->instruction_start());
+    auto* debug_side_table_entry = debug_side_table->GetEntry(pc_offset);
+    DCHECK_NOT_NULL(debug_side_table_entry);
+
+    // Fill stack values.
+    // Use an object without prototype instead of an Array, for nicer displaying
+    // in DevTools. For Arrays, the length field and prototype is displayed,
+    // which does not make too much sense here.
+    int num_locals = static_cast<int>(debug_side_table->num_locals());
+    int value_count = debug_side_table_entry->num_values();
+    for (int i = num_locals; i < value_count; ++i) {
+      WasmValue value = GetValue(debug_side_table_entry, i, fp, debug_break_fp);
+      Handle<Object> value_obj = WasmValueToValueObject(isolate, value);
+      JSObject::AddDataElement(stack_scope_obj,
+                               static_cast<uint32_t>(i - num_locals), value_obj,
+                               NONE);
+    }
+    return stack_scope_obj;
+  }
+
   WireBytesRef GetLocalName(int func_index, int local_index) {
     base::MutexGuard guard(&mutex_);
     if (!local_names_) {
@@ -574,13 +684,56 @@ class DebugInfoImpl {
     return local_names_->GetName(func_index, local_index);
   }
 
-  void SetBreakpoint(int func_index, int offset) {
+  void RecompileLiftoffWithBreakpoints(int func_index, Vector<int> offsets,
+                                       Isolate* current_isolate) {
+    if (func_index == flooded_function_index_) {
+      // We should not be flooding a function that is already flooded.
+      DCHECK(!(offsets.size() == 1 && offsets[0] == 0));
+      flooded_function_index_ = -1;
+    }
+    // Recompile the function with Liftoff, setting the new breakpoints.
+    // Not thread-safe. The caller is responsible for locking {mutex_}.
+    CompilationEnv env = native_module_->CreateCompilationEnv();
+    auto* function = &native_module_->module()->functions[func_index];
+    Vector<const uint8_t> wire_bytes = native_module_->wire_bytes();
+    FunctionBody body{function->sig, function->code.offset(),
+                      wire_bytes.begin() + function->code.offset(),
+                      wire_bytes.begin() + function->code.end_offset()};
+    std::unique_ptr<DebugSideTable> debug_sidetable;
+
+    // Generate additional source positions for current stack frame positions.
+    // These source positions are used to find return addresses in the new code.
+    std::vector<int> stack_frame_positions =
+        StackFramePositions(func_index, current_isolate);
+
+    WasmCompilationResult result = ExecuteLiftoffCompilation(
+        native_module_->engine()->allocator(), &env, body, func_index, nullptr,
+        nullptr, offsets, &debug_sidetable, VectorOf(stack_frame_positions));
+    // Liftoff compilation failure is a FATAL error. We rely on complete Liftoff
+    // support for debugging.
+    if (!result.succeeded()) FATAL("Liftoff compilation failed");
+    DCHECK_NOT_NULL(debug_sidetable);
+
+    WasmCodeRefScope wasm_code_ref_scope;
+    WasmCode* new_code = native_module_->AddCompiledCode(std::move(result));
+    bool added =
+        debug_side_tables_.emplace(new_code, std::move(debug_sidetable)).second;
+    DCHECK(added);
+    USE(added);
+
+    UpdateReturnAddresses(current_isolate, new_code);
+  }
+
+  void SetBreakpoint(int func_index, int offset, Isolate* current_isolate) {
     // Hold the mutex while setting the breakpoint. This guards against multiple
     // isolates setting breakpoints at the same time. We don't really support
     // that scenario yet, but concurrently compiling and installing different
     // Liftoff variants of a function would be problematic.
     base::MutexGuard guard(&mutex_);
 
+    // offset == 0 indicates flooding and should not happen here.
+    DCHECK_NE(0, offset);
+
     std::vector<int>& breakpoints = breakpoints_per_function_[func_index];
     auto insertion_point =
         std::lower_bound(breakpoints.begin(), breakpoints.end(), offset);
@@ -590,87 +743,222 @@ class DebugInfoImpl {
     }
     breakpoints.insert(insertion_point, offset);
 
-    // Recompile the function with Liftoff, setting the new breakpoints.
-    CompilationEnv env = native_module_->CreateCompilationEnv();
-    auto* function = &native_module_->module()->functions[func_index];
-    Vector<const uint8_t> wire_bytes = native_module_->wire_bytes();
-    FunctionBody body{function->sig, function->code.offset(),
-                      wire_bytes.begin() + function->code.offset(),
-                      wire_bytes.begin() + function->code.end_offset()};
-    WasmCompilationResult result = ExecuteLiftoffCompilation(
-        native_module_->engine()->allocator(), &env, body, func_index, nullptr,
-        nullptr, VectorOf(breakpoints));
-    DCHECK(result.succeeded());
+    // No need to recompile if the function is already flooded.
+    if (func_index == flooded_function_index_) return;
 
-    WasmCodeRefScope wasm_code_ref_scope;
-    WasmCode* new_code = native_module_->AddCompiledCode(std::move(result));
+    RecompileLiftoffWithBreakpoints(func_index, VectorOf(breakpoints),
+                                    current_isolate);
+  }
 
-    // TODO(clemensb): OSR active frames on the stack (on all threads).
-    USE(new_code);
+  void FloodWithBreakpoints(int func_index, Isolate* current_isolate) {
+    base::MutexGuard guard(&mutex_);
+    // 0 is an invalid offset used to indicate flooding.
+    int offset = 0;
+    RecompileLiftoffWithBreakpoints(func_index, Vector<int>(&offset, 1),
+                                    current_isolate);
   }
 
- private:
-  DebugSideTable* GetDebugSideTable(AccountingAllocator* allocator,
-                                    int func_index) {
+  void PrepareStep(Isolate* isolate, StackFrameId break_frame_id) {
+    StackTraceFrameIterator it(isolate, break_frame_id);
+    DCHECK(!it.done());
+    DCHECK(it.frame()->is_wasm_compiled());
+    WasmCompiledFrame* frame = WasmCompiledFrame::cast(it.frame());
+    StepAction step_action = isolate->debug()->last_step_action();
+
+    // If we are at a return instruction, then any stepping action is equivalent
+    // to StepOut, and we need to flood the parent function.
+    if (IsAtReturn(frame) || step_action == StepOut) {
+      it.Advance();
+      if (it.done() || !it.frame()->is_wasm_compiled()) return;
+      frame = WasmCompiledFrame::cast(it.frame());
+    }
+
+    if (static_cast<int>(frame->function_index()) != flooded_function_index_) {
+      if (flooded_function_index_ != -1) {
+        std::vector<int>& breakpoints =
+            breakpoints_per_function_[flooded_function_index_];
+        RecompileLiftoffWithBreakpoints(flooded_function_index_,
+                                        VectorOf(breakpoints), isolate);
+      }
+      FloodWithBreakpoints(frame->function_index(), isolate);
+      flooded_function_index_ = frame->function_index();
+    }
+    stepping_frame_ = frame->id();
+  }
+
+  void ClearStepping() { stepping_frame_ = NO_ID; }
+
+  bool IsStepping(WasmCompiledFrame* frame) {
+    Isolate* isolate = frame->wasm_instance().GetIsolate();
+    StepAction last_step_action = isolate->debug()->last_step_action();
+    return stepping_frame_ == frame->id() || last_step_action == StepIn;
+  }
+
+  void RemoveBreakpoint(int func_index, int position,
+                        Isolate* current_isolate) {
     base::MutexGuard guard(&mutex_);
-    if (debug_side_tables_.empty()) {
-      debug_side_tables_.resize(native_module_->module()->functions.size());
+    const auto& function = native_module_->module()->functions[func_index];
+    int offset = position - function.code.offset();
+
+    std::vector<int>& breakpoints = breakpoints_per_function_[func_index];
+    DCHECK_LT(0, offset);
+    auto insertion_point =
+        std::lower_bound(breakpoints.begin(), breakpoints.end(), offset);
+    if (insertion_point != breakpoints.end() && *insertion_point == offset) {
+      breakpoints.erase(insertion_point);
     }
-    if (auto& existing_table = debug_side_tables_[func_index]) {
+    RecompileLiftoffWithBreakpoints(func_index, VectorOf(breakpoints),
+                                    current_isolate);
+  }
+
+  void RemoveDebugSideTables(Vector<WasmCode* const> codes) {
+    base::MutexGuard guard(&mutex_);
+    for (auto* code : codes) {
+      debug_side_tables_.erase(code);
+    }
+  }
+
+ private:
+  const DebugSideTable* GetDebugSideTable(WasmCode* code,
+                                          AccountingAllocator* allocator) {
+    base::MutexGuard guard(&mutex_);
+    if (auto& existing_table = debug_side_tables_[code]) {
       return existing_table.get();
     }
 
     // Otherwise create the debug side table now.
-    const WasmModule* module = native_module_->module();
-    const WasmFunction* function = &module->functions[func_index];
+    auto* module = native_module_->module();
+    auto* function = &module->functions[code->index()];
     ModuleWireBytes wire_bytes{native_module_->wire_bytes()};
     Vector<const byte> function_bytes = wire_bytes.GetFunctionBytes(function);
     CompilationEnv env = native_module_->CreateCompilationEnv();
     FunctionBody func_body{function->sig, 0, function_bytes.begin(),
                            function_bytes.end()};
-    DebugSideTable debug_side_table =
+    std::unique_ptr<DebugSideTable> debug_side_table =
         GenerateLiftoffDebugSideTable(allocator, &env, func_body);
+    DebugSideTable* ret = debug_side_table.get();
 
     // Install into cache and return.
-    debug_side_tables_[func_index] =
-        std::make_unique<DebugSideTable>(std::move(debug_side_table));
-    return debug_side_tables_[func_index].get();
+    debug_side_tables_[code] = std::move(debug_side_table);
+    return ret;
   }
 
   // Get the value of a local (including parameters) or stack value. Stack
   // values follow the locals in the same index space.
   WasmValue GetValue(const DebugSideTable::Entry* debug_side_table_entry,
-                     ValueType type, int index, Address stack_address) {
-    if (debug_side_table_entry->IsConstant(index)) {
+                     int index, Address stack_frame_base,
+                     Address debug_break_fp) const {
+    ValueType type = debug_side_table_entry->value_type(index);
+    if (debug_side_table_entry->is_constant(index)) {
       DCHECK(type == kWasmI32 || type == kWasmI64);
       return type == kWasmI32
-                 ? WasmValue(debug_side_table_entry->GetConstant(index))
+                 ? WasmValue(debug_side_table_entry->i32_constant(index))
                  : WasmValue(
-                       int64_t{debug_side_table_entry->GetConstant(index)});
+                       int64_t{debug_side_table_entry->i32_constant(index)});
+    }
+
+    if (debug_side_table_entry->is_register(index)) {
+      LiftoffRegister reg = LiftoffRegister::from_liftoff_code(
+          debug_side_table_entry->register_code(index));
+      auto gp_addr = [debug_break_fp](Register reg) {
+        return debug_break_fp +
+               WasmDebugBreakFrameConstants::GetPushedGpRegisterOffset(
+                   reg.code());
+      };
+      if (reg.is_gp_pair()) {
+        DCHECK_EQ(kWasmI64, type);
+        uint32_t low_word = ReadUnalignedValue<uint32_t>(gp_addr(reg.low_gp()));
+        uint32_t high_word =
+            ReadUnalignedValue<uint32_t>(gp_addr(reg.high_gp()));
+        return WasmValue((uint64_t{high_word} << 32) | low_word);
+      }
+      if (reg.is_gp()) {
+        return type == kWasmI32
+                   ? WasmValue(ReadUnalignedValue<uint32_t>(gp_addr(reg.gp())))
+                   : WasmValue(ReadUnalignedValue<uint64_t>(gp_addr(reg.gp())));
+      }
+      // TODO(clemensb/zhin): Fix this for SIMD.
+      DCHECK(reg.is_fp() || reg.is_fp_pair());
+      if (reg.is_fp_pair()) UNIMPLEMENTED();
+      Address spilled_addr =
+          debug_break_fp +
+          WasmDebugBreakFrameConstants::GetPushedFpRegisterOffset(
+              reg.fp().code());
+      return type == kWasmF32
+                 ? WasmValue(ReadUnalignedValue<float>(spilled_addr))
+                 : WasmValue(ReadUnalignedValue<double>(spilled_addr));
     }
 
     // Otherwise load the value from the stack.
-    switch (type) {
-      case kWasmI32:
+    Address stack_address =
+        stack_frame_base - debug_side_table_entry->stack_offset(index);
+    switch (type.kind()) {
+      case ValueType::kI32:
         return WasmValue(ReadUnalignedValue<int32_t>(stack_address));
-      case kWasmI64:
+      case ValueType::kI64:
         return WasmValue(ReadUnalignedValue<int64_t>(stack_address));
-      case kWasmF32:
+      case ValueType::kF32:
         return WasmValue(ReadUnalignedValue<float>(stack_address));
-      case kWasmF64:
+      case ValueType::kF64:
         return WasmValue(ReadUnalignedValue<double>(stack_address));
       default:
         UNIMPLEMENTED();
     }
   }
 
+  // After installing a Liftoff code object with a different set of breakpoints,
+  // update return addresses on the stack so that execution resumes in the new
+  // code. The frame layout itself should be independent of breakpoints.
+  // TODO(thibaudm): update other threads as well.
+  void UpdateReturnAddresses(Isolate* isolate, WasmCode* new_code) {
+    DCHECK(new_code->is_liftoff());
+    // The first return location is after the breakpoint, others are after wasm
+    // calls.
+    ReturnLocation return_location = kAfterBreakpoint;
+    for (StackTraceFrameIterator it(isolate); !it.done();
+         it.Advance(), return_location = kAfterWasmCall) {
+      // We still need the flooded function for stepping.
+      if (it.frame()->id() == stepping_frame_) continue;
+      if (!it.is_wasm()) continue;
+      WasmCompiledFrame* frame = WasmCompiledFrame::cast(it.frame());
+      if (frame->native_module() != new_code->native_module()) continue;
+      if (frame->function_index() != new_code->index()) continue;
+      WasmCode* old_code = frame->wasm_code();
+      if (!old_code->is_liftoff()) continue;
+      int pc_offset =
+          static_cast<int>(frame->pc() - old_code->instruction_start());
+      int position = frame->position();
+      int byte_offset = FindByteOffset(pc_offset, old_code);
+      Address new_pc = FindNewPC(new_code, byte_offset, return_location);
+      PointerAuthentication::ReplacePC(frame->pc_address(), new_pc,
+                                       kSystemPointerSize);
+      USE(position);
+      // The frame position should still be the same after OSR.
+      DCHECK_EQ(position, frame->position());
+    }
+  }
+
+  bool IsAtReturn(WasmCompiledFrame* frame) {
+    DisallowHeapAllocation no_gc;
+    int position = frame->position();
+    NativeModule* native_module =
+        frame->wasm_instance().module_object().native_module();
+    uint8_t opcode = native_module->wire_bytes()[position];
+    if (opcode == kExprReturn) return true;
+    // Another implicit return is at the last kExprEnd in the function body.
+    int func_index = frame->function_index();
+    WireBytesRef code = native_module->module()->functions[func_index].code;
+    return static_cast<size_t>(position) == code.end_offset() - 1;
+  }
+
   NativeModule* const native_module_;
 
   // {mutex_} protects all fields below.
-  base::Mutex mutex_;
+  mutable base::Mutex mutex_;
 
-  // DebugSideTable per function, lazily initialized.
-  std::vector<std::unique_ptr<DebugSideTable>> debug_side_tables_;
+  // DebugSideTable per code object, lazily initialized.
+  std::unordered_map<WasmCode*, std::unique_ptr<DebugSideTable>>
+      debug_side_tables_;
 
   // Names of locals, lazily decoded from the wire bytes.
   std::unique_ptr<LocalNames> local_names_;
@@ -679,6 +967,11 @@ class DebugInfoImpl {
   // function).
   std::unordered_map<int, std::vector<int>> breakpoints_per_function_;
 
+  // Store the frame ID when stepping, to avoid breaking in recursive calls of
+  // the same function.
+  StackFrameId stepping_frame_ = NO_ID;
+  int flooded_function_index_ = -1;
+
   DISALLOW_COPY_AND_ASSIGN(DebugInfoImpl);
 };
 
@@ -688,16 +981,43 @@ DebugInfo::DebugInfo(NativeModule* native_module)
 DebugInfo::~DebugInfo() = default;
 
 Handle<JSObject> DebugInfo::GetLocalScopeObject(Isolate* isolate, Address pc,
-                                                Address fp) {
-  return impl_->GetLocalScopeObject(isolate, pc, fp);
+                                                Address fp,
+                                                Address debug_break_fp) {
+  return impl_->GetLocalScopeObject(isolate, pc, fp, debug_break_fp);
+}
+
+Handle<JSObject> DebugInfo::GetStackScopeObject(Isolate* isolate, Address pc,
+                                                Address fp,
+                                                Address debug_break_fp) {
+  return impl_->GetStackScopeObject(isolate, pc, fp, debug_break_fp);
 }
 
 WireBytesRef DebugInfo::GetLocalName(int func_index, int local_index) {
   return impl_->GetLocalName(func_index, local_index);
 }
 
-void DebugInfo::SetBreakpoint(int func_index, int offset) {
-  impl_->SetBreakpoint(func_index, offset);
+void DebugInfo::SetBreakpoint(int func_index, int offset,
+                              Isolate* current_isolate) {
+  impl_->SetBreakpoint(func_index, offset, current_isolate);
+}
+
+void DebugInfo::PrepareStep(Isolate* isolate, StackFrameId break_frame_id) {
+  impl_->PrepareStep(isolate, break_frame_id);
+}
+
+void DebugInfo::ClearStepping() { impl_->ClearStepping(); }
+
+bool DebugInfo::IsStepping(WasmCompiledFrame* frame) {
+  return impl_->IsStepping(frame);
+}
+
+void DebugInfo::RemoveBreakpoint(int func_index, int offset,
+                                 Isolate* current_isolate) {
+  impl_->RemoveBreakpoint(func_index, offset, current_isolate);
+}
+
+void DebugInfo::RemoveDebugSideTables(Vector<WasmCode* const> code) {
+  impl_->RemoveDebugSideTables(code);
 }
 
 }  // namespace wasm
@@ -823,8 +1143,9 @@ void WasmDebugInfo::RedirectToInterpreter(Handle<WasmDebugInfo> debug_info,
         module->functions[func_index].sig);
     std::unique_ptr<wasm::WasmCode> wasm_code = native_module->AddCode(
         func_index, result.code_desc, result.frame_slot_count,
-        result.tagged_parameter_slots, std::move(result.protected_instructions),
-        std::move(result.source_positions), wasm::WasmCode::kInterpreterEntry,
+        result.tagged_parameter_slots,
+        result.protected_instructions_data.as_vector(),
+        result.source_positions.as_vector(), wasm::WasmCode::kInterpreterEntry,
         wasm::ExecutionTier::kInterpreter);
     native_module->PublishCode(std::move(wasm_code));
     DCHECK(native_module->IsRedirectedToInterpreter(func_index));
@@ -877,8 +1198,16 @@ Handle<JSObject> WasmDebugInfo::GetLocalScopeObject(
 }
 
 // static
+Handle<JSObject> WasmDebugInfo::GetStackScopeObject(
+    Handle<WasmDebugInfo> debug_info, Address frame_pointer, int frame_index) {
+  auto* interp_handle = GetInterpreterHandle(*debug_info);
+  auto frame = interp_handle->GetInterpretedFrame(frame_pointer, frame_index);
+  return interp_handle->GetStackScopeObject(frame.get(), debug_info);
+}
+
+// static
 Handle<Code> WasmDebugInfo::GetCWasmEntry(Handle<WasmDebugInfo> debug_info,
-                                          wasm::FunctionSig* sig) {
+                                          const wasm::FunctionSig* sig) {
   Isolate* isolate = debug_info->GetIsolate();
   DCHECK_EQ(debug_info->has_c_wasm_entries(),
             debug_info->has_c_wasm_entry_map());
@@ -909,7 +1238,7 @@ Handle<Code> WasmDebugInfo::GetCWasmEntry(Handle<WasmDebugInfo> debug_info,
 
 namespace {
 
-// Return the next breakable position after {offset_in_func} in function
+// Return the next breakable position at or after {offset_in_func} in function
 // {func_index}, or 0 if there is none.
 // Note that 0 is never a breakable position in wasm, since the first byte
 // contains the locals count for the function.
@@ -926,8 +1255,10 @@ int FindNextBreakablePosition(wasm::NativeModule* native_module, int func_index,
                                   &locals);
   DCHECK_LT(0, locals.encoded_size);
   if (offset_in_func < 0) return 0;
-  for (uint32_t offset : iterator.offsets()) {
-    if (offset >= static_cast<uint32_t>(offset_in_func)) return offset;
+  for (; iterator.has_next(); iterator.next()) {
+    if (iterator.pc_offset() < static_cast<uint32_t>(offset_in_func)) continue;
+    if (!wasm::WasmOpcodes::IsBreakable(iterator.current())) continue;
+    return static_cast<int>(iterator.pc_offset());
   }
   return 0;
 }
@@ -985,7 +1316,7 @@ bool WasmScript::SetBreakPointForFunction(Handle<Script> script, int func_index,
                                   break_point);
 
   if (FLAG_debug_in_liftoff) {
-    native_module->GetDebugInfo()->SetBreakpoint(func_index, offset);
+    native_module->GetDebugInfo()->SetBreakpoint(func_index, offset, isolate);
   } else {
     // Iterate over all instances and tell them to set this new breakpoint.
     // We do this using the weak list of all instances from the script.
@@ -1276,13 +1607,14 @@ bool WasmScript::GetPossibleBreakpoints(
                                     module_start + func.code.end_offset(),
                                     &locals);
     DCHECK_LT(0u, locals.encoded_size);
-    for (uint32_t offset : iterator.offsets()) {
-      uint32_t total_offset = func.code.offset() + offset;
+    for (; iterator.has_next(); iterator.next()) {
+      uint32_t total_offset = func.code.offset() + iterator.pc_offset();
       if (total_offset >= end_offset) {
         DCHECK_EQ(end_func_index, func_idx);
         break;
       }
       if (total_offset < start_offset) continue;
+      if (!wasm::WasmOpcodes::IsBreakable(iterator.current())) continue;
       locations->emplace_back(0, total_offset, debug::kCommonBreakLocation);
     }
   }
diff --git a/deps/v8/src/wasm/wasm-debug.h b/deps/v8/src/wasm/wasm-debug.h
index ca0ab76bf7..2611b7facc 100644
--- a/deps/v8/src/wasm/wasm-debug.h
+++ b/deps/v8/src/wasm/wasm-debug.h
@@ -21,6 +21,9 @@ namespace internal {
 template <typename T>
 class Handle;
 class JSObject;
+template <typename T>
+class Vector;
+class WasmCompiledFrame;
 class WasmInstanceObject;
 
 namespace wasm {
@@ -28,6 +31,7 @@ namespace wasm {
 class DebugInfoImpl;
 class LocalNames;
 class NativeModule;
+class WasmCode;
 class WireBytesRef;
 
 // Side table storing information used to inspect Liftoff frames at runtime.
@@ -37,71 +41,66 @@ class DebugSideTable {
  public:
   class Entry {
    public:
-    struct Constant {
-      int index;
-      int32_t i32_const;
+    enum ValueKind : int8_t { kConstant, kRegister, kStack };
+    struct Value {
+      ValueType type;
+      ValueKind kind;
+      union {
+        int32_t i32_const;  // if kind == kConstant
+        int reg_code;       // if kind == kRegister
+        int stack_offset;   // if kind == kStack
+      };
     };
 
-    Entry(int pc_offset, std::vector<ValueType> stack_types,
-          std::vector<int> stack_offsets, std::vector<Constant> constants)
-        : pc_offset_(pc_offset),
-          stack_types_(std::move(stack_types)),
-          stack_offsets_(std::move(stack_offsets)),
-          constants_(std::move(constants)) {
-      DCHECK(std::is_sorted(constants_.begin(), constants_.end(),
-                            ConstantIndexLess{}));
-      DCHECK_EQ(stack_types_.size(), stack_offsets_.size());
-    }
+    Entry(int pc_offset, std::vector<Value> values)
+        : pc_offset_(pc_offset), values_(std::move(values)) {}
 
     // Constructor for map lookups (only initializes the {pc_offset_}).
     explicit Entry(int pc_offset) : pc_offset_(pc_offset) {}
 
     int pc_offset() const { return pc_offset_; }
-    int stack_height() const { return static_cast<int>(stack_types_.size()); }
-    ValueType stack_type(int stack_index) const {
-      return stack_types_[stack_index];
+
+    int num_values() const { return static_cast<int>(values_.size()); }
+    ValueType value_type(int index) const { return values_[index].type; }
+
+    auto values() const {
+      return base::make_iterator_range(values_.begin(), values_.end());
     }
-    int stack_offset(int stack_index) const {
-      return stack_offsets_[stack_index];
+
+    int stack_offset(int index) const {
+      DCHECK_EQ(kStack, values_[index].kind);
+      return values_[index].stack_offset;
     }
-    // {index} can point to a local or operand stack value.
-    bool IsConstant(int index) const {
-      return std::binary_search(constants_.begin(), constants_.end(),
-                                Constant{index, 0}, ConstantIndexLess{});
+
+    bool is_constant(int index) const {
+      return values_[index].kind == kConstant;
     }
-    int32_t GetConstant(int index) const {
-      DCHECK(IsConstant(index));
-      auto it = std::lower_bound(constants_.begin(), constants_.end(),
-                                 Constant{index, 0}, ConstantIndexLess{});
-      DCHECK_NE(it, constants_.end());
-      DCHECK_EQ(it->index, index);
-      return it->i32_const;
+
+    bool is_register(int index) const {
+      return values_[index].kind == kRegister;
     }
 
-   private:
-    struct ConstantIndexLess {
-      bool operator()(const Constant& a, const Constant& b) const {
-        return a.index < b.index;
-      }
-    };
+    int32_t i32_constant(int index) const {
+      DCHECK_EQ(kConstant, values_[index].kind);
+      return values_[index].i32_const;
+    }
 
+    int32_t register_code(int index) const {
+      DCHECK_EQ(kRegister, values_[index].kind);
+      return values_[index].reg_code;
+    }
+
+   private:
     int pc_offset_;
-    // TODO(clemensb): Merge these vectors into one.
-    std::vector<ValueType> stack_types_;
-    std::vector<int> stack_offsets_;
-    std::vector<Constant> constants_;
+    std::vector<Value> values_;
   };
 
   // Technically it would be fine to copy this class, but there should not be a
   // reason to do so, hence mark it move only.
   MOVE_ONLY_NO_DEFAULT_CONSTRUCTOR(DebugSideTable);
 
-  explicit DebugSideTable(std::vector<ValueType> local_types,
-                          std::vector<int> local_stack_offsets,
-                          std::vector<Entry> entries)
-      : local_types_(std::move(local_types)),
-        local_stack_offsets_(std::move(local_stack_offsets)),
-        entries_(std::move(entries)) {
+  explicit DebugSideTable(int num_locals, std::vector<Entry> entries)
+      : num_locals_(num_locals), entries_(std::move(entries)) {
     DCHECK(
         std::is_sorted(entries_.begin(), entries_.end(), EntryPositionLess{}));
   }
@@ -110,6 +109,7 @@ class DebugSideTable {
     auto it = std::lower_bound(entries_.begin(), entries_.end(),
                                Entry{pc_offset}, EntryPositionLess{});
     if (it == entries_.end() || it->pc_offset() != pc_offset) return nullptr;
+    DCHECK_LE(num_locals_, it->num_values());
     return &*it;
   }
 
@@ -117,12 +117,7 @@ class DebugSideTable {
     return base::make_iterator_range(entries_.begin(), entries_.end());
   }
 
-  size_t num_entries() const { return entries_.size(); }
-  int num_locals() const { return static_cast<int>(local_types_.size()); }
-  ValueType local_type(int index) const { return local_types_[index]; }
-  int local_stack_offset(int index) const {
-    return local_stack_offsets_[index];
-  }
+  int num_locals() const { return num_locals_; }
 
  private:
   struct EntryPositionLess {
@@ -131,8 +126,7 @@ class DebugSideTable {
     }
   };
 
-  std::vector<ValueType> local_types_;
-  std::vector<int32_t> local_stack_offsets_;
+  int num_locals_;
   std::vector<Entry> entries_;
 };
 
@@ -147,11 +141,27 @@ class DebugInfo {
   explicit DebugInfo(NativeModule*);
   ~DebugInfo();
 
-  Handle<JSObject> GetLocalScopeObject(Isolate*, Address pc, Address fp);
+  // {fp} is the frame pointer of the Liftoff frame, {debug_break_fp} that of
+  // the {WasmDebugBreak} frame (if any).
+  Handle<JSObject> GetLocalScopeObject(Isolate*, Address pc, Address fp,
+                                       Address debug_break_fp);
+
+  Handle<JSObject> GetStackScopeObject(Isolate*, Address pc, Address fp,
+                                       Address debug_break_fp);
 
   WireBytesRef GetLocalName(int func_index, int local_index);
 
-  void SetBreakpoint(int func_index, int offset);
+  void SetBreakpoint(int func_index, int offset, Isolate* current_isolate);
+
+  void PrepareStep(Isolate*, StackFrameId);
+
+  void ClearStepping();
+
+  bool IsStepping(WasmCompiledFrame*);
+
+  void RemoveBreakpoint(int func_index, int offset, Isolate* current_isolate);
+
+  void RemoveDebugSideTables(Vector<WasmCode* const>);
 
  private:
   std::unique_ptr<DebugInfoImpl> impl_;
diff --git a/deps/v8/src/wasm/wasm-engine.cc b/deps/v8/src/wasm/wasm-engine.cc
index c1fceb8311..573812e8fa 100644
--- a/deps/v8/src/wasm/wasm-engine.cc
+++ b/deps/v8/src/wasm/wasm-engine.cc
@@ -4,7 +4,9 @@
 
 #include "src/wasm/wasm-engine.h"
 
+#include "src/base/functional.h"
 #include "src/base/platform/time.h"
+#include "src/common/globals.h"
 #include "src/diagnostics/code-tracer.h"
 #include "src/diagnostics/compilation-statistics.h"
 #include "src/execution/frames.h"
@@ -20,8 +22,13 @@
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/module-instantiate.h"
 #include "src/wasm/streaming-decoder.h"
+#include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-objects-inl.h"
 
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+#include "src/debug/wasm/gdb-server/gdb-server.h"
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
 namespace v8 {
 namespace internal {
 namespace wasm {
@@ -129,22 +136,29 @@ class WasmGCForegroundTask : public CancelableTask {
 std::shared_ptr<NativeModule> NativeModuleCache::MaybeGetNativeModule(
     ModuleOrigin origin, Vector<const uint8_t> wire_bytes) {
   if (origin != kWasmOrigin) return nullptr;
-  // Temporarily disabled to fix stability issue on M-81
-  // (https://crbug.com/1070199).
-  if (!FLAG_future) return nullptr;
   base::MutexGuard lock(&mutex_);
+  size_t prefix_hash = PrefixHash(wire_bytes);
+  NativeModuleCache::Key key{prefix_hash, wire_bytes};
   while (true) {
-    auto it = map_.find(wire_bytes);
+    auto it = map_.find(key);
     if (it == map_.end()) {
+      // Even though this exact key is not in the cache, there might be a
+      // matching prefix hash indicating that a streaming compilation is
+      // currently compiling a module with the same prefix. {OnFinishedStream}
+      // happens on the main thread too, so waiting for streaming compilation to
+      // finish would create a deadlock. Instead, compile the module twice and
+      // handle the conflict in {UpdateNativeModuleCache}.
+
       // Insert a {nullopt} entry to let other threads know that this
       // {NativeModule} is already being created on another thread.
-      map_.emplace(wire_bytes, base::nullopt);
+      auto p = map_.emplace(key, base::nullopt);
+      USE(p);
+      DCHECK(p.second);
       return nullptr;
     }
-    auto maybe_native_module = it->second;
-    if (maybe_native_module.has_value()) {
-      auto weak_ptr = maybe_native_module.value();
-      if (auto shared_native_module = weak_ptr.lock()) {
+    if (it->second.has_value()) {
+      if (auto shared_native_module = it->second.value().lock()) {
+        DCHECK_EQ(shared_native_module->wire_bytes(), wire_bytes);
         return shared_native_module;
       }
     }
@@ -152,50 +166,108 @@ std::shared_ptr<NativeModule> NativeModuleCache::MaybeGetNativeModule(
   }
 }
 
-void NativeModuleCache::Update(std::shared_ptr<NativeModule> native_module,
-                               bool error) {
+bool NativeModuleCache::GetStreamingCompilationOwnership(size_t prefix_hash) {
+  base::MutexGuard lock(&mutex_);
+  auto it = map_.lower_bound(Key{prefix_hash, {}});
+  if (it != map_.end() && it->first.prefix_hash == prefix_hash) {
+    DCHECK_IMPLIES(!it->first.bytes.empty(),
+                   PrefixHash(it->first.bytes) == prefix_hash);
+    return false;
+  }
+  Key key{prefix_hash, {}};
+  DCHECK_EQ(0, map_.count(key));
+  map_.emplace(key, base::nullopt);
+  return true;
+}
+
+void NativeModuleCache::StreamingCompilationFailed(size_t prefix_hash) {
+  base::MutexGuard lock(&mutex_);
+  Key key{prefix_hash, {}};
+  DCHECK_EQ(1, map_.count(key));
+  map_.erase(key);
+  cache_cv_.NotifyAll();
+}
+
+std::shared_ptr<NativeModule> NativeModuleCache::Update(
+    std::shared_ptr<NativeModule> native_module, bool error) {
   DCHECK_NOT_NULL(native_module);
-  if (native_module->module()->origin != kWasmOrigin) return;
-  // Temporarily disabled to fix stability issue on M-81
-  // (https://crbug.com/1070199).
-  if (!FLAG_future) return;
+  if (native_module->module()->origin != kWasmOrigin) return native_module;
   Vector<const uint8_t> wire_bytes = native_module->wire_bytes();
+  DCHECK(!wire_bytes.empty());
+  size_t prefix_hash = PrefixHash(native_module->wire_bytes());
   base::MutexGuard lock(&mutex_);
-  auto it = map_.find(wire_bytes);
-  DCHECK_NE(it, map_.end());
-  DCHECK(!it->second.has_value());
-  // The lifetime of the temporary entry's bytes is unknown. Use the new native
-  // module's owned copy of the bytes for the key instead.
-  map_.erase(it);
+  map_.erase(Key{prefix_hash, {}});
+  const Key key{prefix_hash, wire_bytes};
+  auto it = map_.find(key);
+  if (it != map_.end()) {
+    if (it->second.has_value()) {
+      auto conflicting_module = it->second.value().lock();
+      if (conflicting_module != nullptr) {
+        DCHECK_EQ(conflicting_module->wire_bytes(), wire_bytes);
+        return conflicting_module;
+      }
+    }
+    map_.erase(it);
+  }
   if (!error) {
-    map_.emplace(wire_bytes, base::Optional<std::weak_ptr<NativeModule>>(
-                                 std::move(native_module)));
+    // The key now points to the new native module's owned copy of the bytes,
+    // so that it stays valid until the native module is freed and erased from
+    // the map.
+    auto p = map_.emplace(
+        key, base::Optional<std::weak_ptr<NativeModule>>(native_module));
+    USE(p);
+    DCHECK(p.second);
   }
   cache_cv_.NotifyAll();
+  return native_module;
 }
 
 void NativeModuleCache::Erase(NativeModule* native_module) {
+  if (native_module->module()->origin != kWasmOrigin) return;
+  // Happens in some tests where bytes are set directly.
+  if (native_module->wire_bytes().empty()) return;
   base::MutexGuard lock(&mutex_);
-  auto cache_it = map_.find(native_module->wire_bytes());
-  // Not all native modules are stored in the cache currently. In particular
-  // streaming compilation and asmjs compilation results are not. So make
-  // sure that we only delete existing and expired entries.
-  // Do not erase {nullopt} values either, as they indicate that the
-  // {NativeModule} is currently being created in another thread.
-  if (cache_it != map_.end() && cache_it->second.has_value() &&
-      cache_it->second.value().expired()) {
-    map_.erase(cache_it);
-    cache_cv_.NotifyAll();
-  }
+  size_t prefix_hash = PrefixHash(native_module->wire_bytes());
+  map_.erase(Key{prefix_hash, native_module->wire_bytes()});
+  cache_cv_.NotifyAll();
 }
 
-size_t NativeModuleCache::WireBytesHasher::operator()(
-    const Vector<const uint8_t>& bytes) const {
+// static
+size_t NativeModuleCache::WireBytesHash(Vector<const uint8_t> bytes) {
   return StringHasher::HashSequentialString(
       reinterpret_cast<const char*>(bytes.begin()), bytes.length(),
       kZeroHashSeed);
 }
 
+// static
+size_t NativeModuleCache::PrefixHash(Vector<const uint8_t> wire_bytes) {
+  // Compute the hash as a combined hash of the sections up to the code section
+  // header, to mirror the way streaming compilation does it.
+  Decoder decoder(wire_bytes.begin(), wire_bytes.end());
+  decoder.consume_bytes(8, "module header");
+  size_t hash = NativeModuleCache::WireBytesHash(wire_bytes.SubVector(0, 8));
+  SectionCode section_id = SectionCode::kUnknownSectionCode;
+  while (decoder.ok() && decoder.more()) {
+    section_id = static_cast<SectionCode>(decoder.consume_u8());
+    uint32_t section_size = decoder.consume_u32v("section size");
+    if (section_id == SectionCode::kCodeSectionCode) {
+      uint32_t num_functions = decoder.consume_u32v("num functions");
+      // If {num_functions} is 0, the streaming decoder skips the section. Do
+      // the same here to ensure hashes are consistent.
+      if (num_functions != 0) {
+        hash = base::hash_combine(hash, section_size);
+      }
+      break;
+    }
+    const uint8_t* payload_start = decoder.pc();
+    decoder.consume_bytes(section_size, "section payload");
+    size_t section_hash = NativeModuleCache::WireBytesHash(
+        Vector<const uint8_t>(payload_start, section_size));
+    hash = base::hash_combine(hash, section_hash);
+  }
+  return hash;
+}
+
 struct WasmEngine::CurrentGCInfo {
   explicit CurrentGCInfo(int8_t gc_sequence_index)
       : gc_sequence_index(gc_sequence_index) {
@@ -261,6 +333,9 @@ struct WasmEngine::IsolateInfo {
   std::shared_ptr<v8::TaskRunner> foreground_task_runner;
 
   const std::shared_ptr<Counters> async_counters;
+
+  // Keep new modules in tiered down state.
+  bool keep_tiered_down = false;
 };
 
 struct WasmEngine::NativeModuleInfo {
@@ -285,6 +360,11 @@ struct WasmEngine::NativeModuleInfo {
 WasmEngine::WasmEngine() : code_manager_(FLAG_wasm_max_code_space * MB) {}
 
 WasmEngine::~WasmEngine() {
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+  // Synchronize on the GDB-remote thread, if running.
+  gdb_server_ = nullptr;
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
   // Synchronize on all background compile tasks.
   background_compile_task_manager_.CancelAndWait();
   // All AsyncCompileJobs have been canceled.
@@ -293,6 +373,8 @@ WasmEngine::~WasmEngine() {
   DCHECK(isolates_.empty());
   // All NativeModules did die.
   DCHECK(native_modules_.empty());
+  // Native module cache does not leak.
+  DCHECK(native_module_cache_.empty());
 }
 
 bool WasmEngine::SyncValidate(Isolate* isolate, const WasmFeatures& enabled,
@@ -368,9 +450,21 @@ MaybeHandle<WasmModuleObject> WasmEngine::SyncCompile(
                             std::move(result).value(), bytes, &export_wrappers);
   if (!native_module) return {};
 
-  Handle<Script> script = CreateWasmScript(
-      isolate, bytes, VectorOf(native_module->module()->source_map_url),
-      native_module->module()->name);
+#ifdef DEBUG
+  // Ensure that code GC will check this isolate for live code.
+  {
+    base::MutexGuard lock(&mutex_);
+    DCHECK_EQ(1, isolates_.count(isolate));
+    DCHECK_EQ(1, isolates_[isolate]->native_modules.count(native_module.get()));
+    DCHECK_EQ(1, native_modules_.count(native_module.get()));
+    DCHECK_EQ(1, native_modules_[native_module.get()]->isolates.count(isolate));
+  }
+#endif
+
+  Handle<Script> script =
+      CreateWasmScript(isolate, bytes.module_bytes(),
+                       VectorOf(native_module->module()->source_map_url),
+                       native_module->module()->name);
 
   // Create the compiled module object and populate with compiled functions
   // and information needed at instantiation time. This object needs to be
@@ -500,6 +594,35 @@ void WasmEngine::RecompileAllFunctions(Isolate* isolate,
   RecompileNativeModule(isolate, native_module, tier);
 }
 
+void WasmEngine::TierDownAllModulesPerIsolate(Isolate* isolate) {
+  std::vector<NativeModule*> native_modules;
+  {
+    base::MutexGuard lock(&mutex_);
+    if (isolates_[isolate]->keep_tiered_down) return;
+    isolates_[isolate]->keep_tiered_down = true;
+    for (auto* native_module : isolates_[isolate]->native_modules) {
+      native_modules.push_back(native_module);
+    }
+  }
+  for (auto* native_module : native_modules) {
+    native_module->TierDown(isolate);
+  }
+}
+
+void WasmEngine::TierUpAllModulesPerIsolate(Isolate* isolate) {
+  std::vector<NativeModule*> native_modules;
+  {
+    base::MutexGuard lock(&mutex_);
+    isolates_[isolate]->keep_tiered_down = false;
+    for (auto* native_module : isolates_[isolate]->native_modules) {
+      native_modules.push_back(native_module);
+    }
+  }
+  for (auto* native_module : native_modules) {
+    native_module->TierUp(isolate);
+  }
+}
+
 std::shared_ptr<NativeModule> WasmEngine::ExportNativeModule(
     Handle<WasmModuleObject> module_object) {
   return module_object->shared_native_module();
@@ -509,9 +632,10 @@ Handle<WasmModuleObject> WasmEngine::ImportNativeModule(
     Isolate* isolate, std::shared_ptr<NativeModule> shared_native_module) {
   NativeModule* native_module = shared_native_module.get();
   ModuleWireBytes wire_bytes(native_module->wire_bytes());
-  Handle<Script> script = CreateWasmScript(
-      isolate, wire_bytes, VectorOf(native_module->module()->source_map_url),
-      native_module->module()->name);
+  Handle<Script> script =
+      CreateWasmScript(isolate, wire_bytes.module_bytes(),
+                       VectorOf(native_module->module()->source_map_url),
+                       native_module->module()->name);
   Handle<FixedArray> export_wrappers;
   CompileJsToWasmWrappers(isolate, native_module->module(), &export_wrappers);
   Handle<WasmModuleObject> module_object = WasmModuleObject::New(
@@ -623,15 +747,6 @@ void WasmEngine::DeleteCompileJobsOnIsolate(Isolate* isolate) {
   }
 }
 
-namespace {
-int GetGCTimeMicros(base::TimeTicks start) {
-  DCHECK(!start.IsNull());
-  int64_t duration_us = (base::TimeTicks::Now() - start).InMicroseconds();
-  return static_cast<int>(
-      std::min(std::max(int64_t{0}, duration_us), int64_t{kMaxInt}));
-}
-}  // namespace
-
 void WasmEngine::AddIsolate(Isolate* isolate) {
   base::MutexGuard guard(&mutex_);
   DCHECK_EQ(0, isolates_.count(isolate));
@@ -651,13 +766,6 @@ void WasmEngine::AddIsolate(Isolate* isolate) {
     for (auto* native_module : engine->isolates_[isolate]->native_modules) {
       native_module->SampleCodeSize(counters, NativeModule::kSampling);
     }
-    // If there is an ongoing code GC, sample its time here. This will record
-    // samples for very long-running or never ending GCs.
-    if (engine->current_gc_info_ &&
-        !engine->current_gc_info_->start_time.IsNull()) {
-      isolate->counters()->wasm_code_gc_time()->AddSample(
-          GetGCTimeMicros(engine->current_gc_info_->start_time));
-    }
   };
   isolate->heap()->AddGCEpilogueCallback(callback, v8::kGCTypeMarkSweepCompact,
                                          nullptr);
@@ -746,30 +854,69 @@ void WasmEngine::LogOutstandingCodesForIsolate(Isolate* isolate) {
 std::shared_ptr<NativeModule> WasmEngine::NewNativeModule(
     Isolate* isolate, const WasmFeatures& enabled,
     std::shared_ptr<const WasmModule> module, size_t code_size_estimate) {
-  // TODO(clemensb): Remove --wasm-far-jump-table and {can_request_more}.
-  bool can_request_more =
-      !wasm::NativeModule::kNeedsFarJumpsBetweenCodeSpaces ||
-      FLAG_wasm_far_jump_table;
-  std::shared_ptr<NativeModule> native_module =
-      code_manager_.NewNativeModule(this, isolate, enabled, code_size_estimate,
-                                    can_request_more, std::move(module));
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+  if (FLAG_wasm_gdb_remote && !gdb_server_) {
+    gdb_server_ = std::make_unique<gdb_server::GdbServer>();
+  }
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
+  std::shared_ptr<NativeModule> native_module = code_manager_.NewNativeModule(
+      this, isolate, enabled, code_size_estimate, std::move(module));
   base::MutexGuard lock(&mutex_);
   auto pair = native_modules_.insert(std::make_pair(
       native_module.get(), std::make_unique<NativeModuleInfo>()));
   DCHECK(pair.second);  // inserted new entry.
   pair.first->second.get()->isolates.insert(isolate);
   isolates_[isolate]->native_modules.insert(native_module.get());
+  if (isolates_[isolate]->keep_tiered_down) {
+    native_module->SetTieredDown();
+  }
   return native_module;
 }
 
 std::shared_ptr<NativeModule> WasmEngine::MaybeGetNativeModule(
-    ModuleOrigin origin, Vector<const uint8_t> wire_bytes) {
-  return native_module_cache_.MaybeGetNativeModule(origin, wire_bytes);
+    ModuleOrigin origin, Vector<const uint8_t> wire_bytes, Isolate* isolate) {
+  std::shared_ptr<NativeModule> native_module =
+      native_module_cache_.MaybeGetNativeModule(origin, wire_bytes);
+  if (native_module) {
+    base::MutexGuard guard(&mutex_);
+    auto& native_module_info = native_modules_[native_module.get()];
+    if (!native_module_info) {
+      native_module_info = std::make_unique<NativeModuleInfo>();
+    }
+    native_module_info->isolates.insert(isolate);
+    isolates_[isolate]->native_modules.insert(native_module.get());
+  }
+  return native_module;
 }
 
-void WasmEngine::UpdateNativeModuleCache(
-    std::shared_ptr<NativeModule> native_module, bool error) {
-  native_module_cache_.Update(native_module, error);
+bool WasmEngine::UpdateNativeModuleCache(
+    bool error, std::shared_ptr<NativeModule>* native_module,
+    Isolate* isolate) {
+  // Pass {native_module} by value here to keep it alive until at least after
+  // we returned from {Update}. Otherwise, we might {Erase} it inside {Update}
+  // which would lock the mutex twice.
+  auto prev = native_module->get();
+  *native_module = native_module_cache_.Update(*native_module, error);
+
+  if (prev == native_module->get()) return true;
+
+  base::MutexGuard guard(&mutex_);
+  auto& native_module_info = native_modules_[native_module->get()];
+  if (!native_module_info) {
+    native_module_info = std::make_unique<NativeModuleInfo>();
+  }
+  native_module_info->isolates.insert(isolate);
+  isolates_[isolate]->native_modules.insert((*native_module).get());
+  return false;
+}
+
+bool WasmEngine::GetStreamingCompilationOwnership(size_t prefix_hash) {
+  return native_module_cache_.GetStreamingCompilationOwnership(prefix_hash);
+}
+
+void WasmEngine::StreamingCompilationFailed(size_t prefix_hash) {
+  native_module_cache_.StreamingCompilationFailed(prefix_hash);
 }
 
 void WasmEngine::FreeNativeModule(NativeModule* native_module) {
@@ -947,9 +1094,6 @@ void WasmEngine::TriggerGC(int8_t gc_sequence_index) {
   DCHECK(FLAG_wasm_code_gc);
   new_potentially_dead_code_size_ = 0;
   current_gc_info_.reset(new CurrentGCInfo(gc_sequence_index));
-  if (base::TimeTicks::IsHighResolution()) {
-    current_gc_info_->start_time = base::TimeTicks::Now();
-  }
   // Add all potentially dead code to this GC, and trigger a GC task in each
   // isolate.
   for (auto& entry : native_modules_) {
@@ -1011,16 +1155,8 @@ void WasmEngine::PotentiallyFinishCurrentGC() {
 
   FreeDeadCodeLocked(dead_code);
 
-  int duration_us = 0;
-  if (!current_gc_info_->start_time.IsNull()) {
-    duration_us = GetGCTimeMicros(current_gc_info_->start_time);
-    for (auto& entry : isolates_) {
-      entry.second->async_counters->wasm_code_gc_time()->AddSample(duration_us);
-    }
-  }
-
-  TRACE_CODE_GC("Took %d us; found %zu dead code objects, freed %zu.\n",
-                duration_us, current_gc_info_->dead_code.size(), num_freed);
+  TRACE_CODE_GC("Found %zu dead code objects, freed %zu.\n",
+                current_gc_info_->dead_code.size(), num_freed);
   USE(num_freed);
 
   int8_t next_gc_sequence_index = current_gc_info_->next_gc_sequence_index;
@@ -1050,12 +1186,18 @@ std::shared_ptr<WasmEngine> WasmEngine::GetWasmEngine() {
   return *GetSharedWasmEngine();
 }
 
-// {max_mem_pages} is declared in wasm-limits.h.
-uint32_t max_mem_pages() {
+// {max_initial_mem_pages} is declared in wasm-limits.h.
+uint32_t max_initial_mem_pages() {
   STATIC_ASSERT(kV8MaxWasmMemoryPages <= kMaxUInt32);
   return std::min(uint32_t{kV8MaxWasmMemoryPages}, FLAG_wasm_max_mem_pages);
 }
 
+uint32_t max_maximum_mem_pages() {
+  STATIC_ASSERT(kV8MaxWasmMemoryPages <= kMaxUInt32);
+  return std::min(uint32_t{kV8MaxWasmMemoryPages},
+                  FLAG_wasm_max_mem_pages_growth);
+}
+
 // {max_table_init_entries} is declared in wasm-limits.h.
 uint32_t max_table_init_entries() {
   return std::min(uint32_t{kV8MaxWasmTableInitEntries},
diff --git a/deps/v8/src/wasm/wasm-engine.h b/deps/v8/src/wasm/wasm-engine.h
index 073d617b31..7d14fef506 100644
--- a/deps/v8/src/wasm/wasm-engine.h
+++ b/deps/v8/src/wasm/wasm-engine.h
@@ -5,6 +5,8 @@
 #ifndef V8_WASM_WASM_ENGINE_H_
 #define V8_WASM_WASM_ENGINE_H_
 
+#include <algorithm>
+#include <map>
 #include <memory>
 #include <unordered_map>
 #include <unordered_set>
@@ -34,6 +36,10 @@ class ErrorThrower;
 struct ModuleWireBytes;
 class WasmFeatures;
 
+namespace gdb_server {
+class GdbServer;
+}
+
 class V8_EXPORT_PRIVATE CompilationResultResolver {
  public:
   virtual void OnCompilationSucceeded(Handle<WasmModuleObject> result) = 0;
@@ -51,15 +57,57 @@ class V8_EXPORT_PRIVATE InstantiationResultResolver {
 // Native modules cached by their wire bytes.
 class NativeModuleCache {
  public:
-  struct WireBytesHasher {
-    size_t operator()(const Vector<const uint8_t>& bytes) const;
+  struct Key {
+    // Store the prefix hash as part of the key for faster lookup, and to
+    // quickly check existing prefixes for streaming compilation.
+    size_t prefix_hash;
+    Vector<const uint8_t> bytes;
+
+    bool operator==(const Key& other) const {
+      bool eq = bytes == other.bytes;
+      DCHECK_IMPLIES(eq, prefix_hash == other.prefix_hash);
+      return eq;
+    }
+
+    bool operator<(const Key& other) const {
+      if (prefix_hash != other.prefix_hash) {
+        DCHECK_IMPLIES(!bytes.empty() && !other.bytes.empty(),
+                       bytes != other.bytes);
+        return prefix_hash < other.prefix_hash;
+      }
+      if (bytes.size() != other.bytes.size()) {
+        return bytes.size() < other.bytes.size();
+      }
+      // Fast path when the base pointers are the same.
+      // Also handles the {nullptr} case which would be UB for memcmp.
+      if (bytes.begin() == other.bytes.begin()) {
+        DCHECK_EQ(prefix_hash, other.prefix_hash);
+        return false;
+      }
+      DCHECK_NOT_NULL(bytes.begin());
+      DCHECK_NOT_NULL(other.bytes.begin());
+      return memcmp(bytes.begin(), other.bytes.begin(), bytes.size()) < 0;
+    }
   };
 
   std::shared_ptr<NativeModule> MaybeGetNativeModule(
       ModuleOrigin origin, Vector<const uint8_t> wire_bytes);
-  void Update(std::shared_ptr<NativeModule> native_module, bool error);
+  bool GetStreamingCompilationOwnership(size_t prefix_hash);
+  void StreamingCompilationFailed(size_t prefix_hash);
+  std::shared_ptr<NativeModule> Update(
+      std::shared_ptr<NativeModule> native_module, bool error);
   void Erase(NativeModule* native_module);
 
+  bool empty() { return map_.empty(); }
+
+  static size_t WireBytesHash(Vector<const uint8_t> bytes);
+
+  // Hash the wire bytes up to the code section header. Used as a heuristic to
+  // avoid streaming compilation of modules that are likely already in the
+  // cache. See {GetStreamingCompilationOwnership}. Assumes that the bytes have
+  // already been validated.
+  static size_t PrefixHash(Vector<const uint8_t> wire_bytes);
+
  private:
   // Each key points to the corresponding native module's wire bytes, so they
   // should always be valid as long as the native module is alive.  When
@@ -72,10 +120,7 @@ class NativeModuleCache {
   // before trying to get it from the cache.
   // By contrast, an expired {weak_ptr} indicates that the native module died
   // and will soon be cleaned up from the cache.
-  std::unordered_map<Vector<const uint8_t>,
-                     base::Optional<std::weak_ptr<NativeModule>>,
-                     WireBytesHasher>
-      map_;
+  std::map<Key, base::Optional<std::weak_ptr<NativeModule>>> map_;
 
   base::Mutex mutex_;
 
@@ -86,13 +131,13 @@ class NativeModuleCache {
 };
 
 // The central data structure that represents an engine instance capable of
-// loading, instantiating, and executing WASM code.
+// loading, instantiating, and executing Wasm code.
 class V8_EXPORT_PRIVATE WasmEngine {
  public:
   WasmEngine();
   ~WasmEngine();
 
-  // Synchronously validates the given bytes that represent an encoded WASM
+  // Synchronously validates the given bytes that represent an encoded Wasm
   // module.
   bool SyncValidate(Isolate* isolate, const WasmFeatures& enabled,
                     const ModuleWireBytes& bytes);
@@ -107,14 +152,14 @@ class V8_EXPORT_PRIVATE WasmEngine {
       Isolate* isolate, Handle<AsmWasmData> asm_wasm_data,
       Handle<Script> script);
 
-  // Synchronously compiles the given bytes that represent an encoded WASM
+  // Synchronously compiles the given bytes that represent an encoded Wasm
   // module.
   MaybeHandle<WasmModuleObject> SyncCompile(Isolate* isolate,
                                             const WasmFeatures& enabled,
                                             ErrorThrower* thrower,
                                             const ModuleWireBytes& bytes);
 
-  // Synchronously instantiate the given WASM module with the given imports.
+  // Synchronously instantiate the given Wasm module with the given imports.
   // If the module represents an asm.js module, then the supplied {memory}
   // should be used as the memory of the instance.
   MaybeHandle<WasmInstanceObject> SyncInstantiate(
@@ -123,7 +168,7 @@ class V8_EXPORT_PRIVATE WasmEngine {
       MaybeHandle<JSArrayBuffer> memory);
 
   // Begin an asynchronous compilation of the given bytes that represent an
-  // encoded WASM module.
+  // encoded Wasm module.
   // The {is_shared} flag indicates if the bytes backing the module could
   // be shared across threads, i.e. could be concurrently modified.
   void AsyncCompile(Isolate* isolate, const WasmFeatures& enabled,
@@ -131,7 +176,7 @@ class V8_EXPORT_PRIVATE WasmEngine {
                     const ModuleWireBytes& bytes, bool is_shared,
                     const char* api_method_name_for_errors);
 
-  // Begin an asynchronous instantiation of the given WASM module.
+  // Begin an asynchronous instantiation of the given Wasm module.
   void AsyncInstantiate(Isolate* isolate,
                         std::unique_ptr<InstantiationResultResolver> resolver,
                         Handle<WasmModuleObject> module_object,
@@ -152,6 +197,9 @@ class V8_EXPORT_PRIVATE WasmEngine {
   void RecompileAllFunctions(Isolate* isolate, NativeModule* native_module,
                              ExecutionTier tier);
 
+  void TierDownAllModulesPerIsolate(Isolate* isolate);
+  void TierUpAllModulesPerIsolate(Isolate* isolate);
+
   // Exports the sharable parts of the given module object so that they can be
   // transferred to a different Context/Isolate using the same engine.
   std::shared_ptr<NativeModule> ExportNativeModule(
@@ -226,21 +274,41 @@ class V8_EXPORT_PRIVATE WasmEngine {
       Isolate* isolate, const WasmFeatures& enabled_features,
       std::shared_ptr<const WasmModule> module, size_t code_size_estimate);
 
-  // Try getting a cached {NativeModule}. The {wire_bytes}' underlying array
-  // should be valid at least until the next call to {UpdateNativeModuleCache}.
-  // Return nullptr if no {NativeModule} exists for these bytes. In this case,
-  // an empty entry is added to let other threads know that a {NativeModule} for
-  // these bytes is currently being created. The caller should eventually call
-  // {UpdateNativeModuleCache} to update the entry and wake up other threads.
+  // Try getting a cached {NativeModule}, or get ownership for its creation.
+  // Return {nullptr} if no {NativeModule} exists for these bytes. In this case,
+  // a {nullopt} entry is added to let other threads know that a {NativeModule}
+  // for these bytes is currently being created. The caller should eventually
+  // call {UpdateNativeModuleCache} to update the entry and wake up other
+  // threads. The {wire_bytes}' underlying array should be valid at least until
+  // the call to {UpdateNativeModuleCache}.
   std::shared_ptr<NativeModule> MaybeGetNativeModule(
-      ModuleOrigin origin, Vector<const uint8_t> wire_bytes);
+      ModuleOrigin origin, Vector<const uint8_t> wire_bytes, Isolate* isolate);
 
-  // Update the temporary entry inserted by {MaybeGetNativeModule}.
-  // If {error} is true, the entry is erased. Otherwise the entry is updated to
-  // match the {native_module} argument. Wake up threads waiting for this native
+  // Replace the temporary {nullopt} with the new native module, or
+  // erase it if any error occurred. Wake up blocked threads waiting for this
   // module.
-  void UpdateNativeModuleCache(std::shared_ptr<NativeModule> native_module,
-                               bool error);
+  // To avoid a deadlock on the main thread between synchronous and streaming
+  // compilation, two compilation jobs might compile the same native module at
+  // the same time. In this case the first call to {UpdateNativeModuleCache}
+  // will insert the native module in the cache, and the last call will discard
+  // its {native_module} argument and replace it with the existing entry.
+  // Return true in the former case, and false in the latter.
+  bool UpdateNativeModuleCache(bool error,
+                               std::shared_ptr<NativeModule>* native_module,
+                               Isolate* isolate);
+
+  // Register this prefix hash for a streaming compilation job.
+  // If the hash is not in the cache yet, the function returns true and the
+  // caller owns the compilation of this module.
+  // Otherwise another compilation job is currently preparing or has already
+  // prepared a module with the same prefix hash. The caller should wait until
+  // the stream is finished and call {MaybeGetNativeModule} to either get the
+  // module from the cache or get ownership for the compilation of these bytes.
+  bool GetStreamingCompilationOwnership(size_t prefix_hash);
+
+  // Remove the prefix hash from the cache when compilation failed. If
+  // compilation succeeded, {UpdateNativeModuleCache} should be called instead.
+  void StreamingCompilationFailed(size_t prefix_hash);
 
   void FreeNativeModule(NativeModule*);
 
@@ -305,6 +373,11 @@ class V8_EXPORT_PRIVATE WasmEngine {
   // engine, they must all be finished because they access the allocator.
   CancelableTaskManager background_compile_task_manager_;
 
+#ifdef V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+  // Implements a GDB-remote stub for WebAssembly debugging.
+  std::unique_ptr<gdb_server::GdbServer> gdb_server_;
+#endif  // V8_ENABLE_WASM_GDB_REMOTE_DEBUGGING
+
   // This mutex protects all information which is mutated concurrently or
   // fields that are initialized lazily on the first access.
   base::Mutex mutex_;
diff --git a/deps/v8/src/wasm/wasm-external-refs.cc b/deps/v8/src/wasm/wasm-external-refs.cc
index 5c1058d788..6dbb939384 100644
--- a/deps/v8/src/wasm/wasm-external-refs.cc
+++ b/deps/v8/src/wasm/wasm-external-refs.cc
@@ -11,7 +11,9 @@
 
 #include "src/base/bits.h"
 #include "src/base/ieee754.h"
+#include "src/common/assert-scope.h"
 #include "src/utils/memcopy.h"
+#include "src/wasm/wasm-objects-inl.h"
 
 #if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
     defined(THREAD_SANITIZER) || defined(LEAK_SANITIZER) ||    \
@@ -323,60 +325,140 @@ void float64_pow_wrapper(Address data) {
   WriteUnalignedValue<double>(data, base::ieee754::pow(x, y));
 }
 
-// Asan on Windows triggers exceptions in this function to allocate
-// shadow memory lazily. When this function is called from WebAssembly,
-// these exceptions would be handled by the trap handler before they get
-// handled by Asan, and thereby confuse the thread-in-wasm flag.
-// Therefore we disable ASAN for this function. Alternatively we could
-// reset the thread-in-wasm flag before calling this function. However,
-// as this is only a problem with Asan on Windows, we did not consider
-// it worth the overhead.
-DISABLE_ASAN void memory_copy_wrapper(Address dst, Address src, uint32_t size) {
-  // Use explicit forward and backward copy to match the required semantics for
-  // the memory.copy instruction. It is assumed that the caller of this
-  // function has already performed bounds checks, so {src + size} and
-  // {dst + size} should not overflow.
-  DCHECK(src + size >= src && dst + size >= dst);
-  uint8_t* dst8 = reinterpret_cast<uint8_t*>(dst);
-  uint8_t* src8 = reinterpret_cast<uint8_t*>(src);
-  if (src < dst && src + size > dst && dst + size > src) {
-    dst8 += size - 1;
-    src8 += size - 1;
-    for (; size > 0; size--) {
-      *dst8-- = *src8--;
+namespace {
+class ThreadNotInWasmScope {
+// Asan on Windows triggers exceptions to allocate shadow memory lazily. When
+// this function is called from WebAssembly, these exceptions would be handled
+// by the trap handler before they get handled by Asan, and thereby confuse the
+// thread-in-wasm flag. Therefore we disable ASAN for this function.
+// Alternatively we could reset the thread-in-wasm flag before calling this
+// function. However, as this is only a problem with Asan on Windows, we did not
+// consider it worth the overhead.
+#if defined(RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS)
+
+ public:
+  ThreadNotInWasmScope() : thread_was_in_wasm_(trap_handler::IsThreadInWasm()) {
+    if (thread_was_in_wasm_) {
+      trap_handler::ClearThreadInWasm();
     }
-  } else {
-    for (; size > 0; size--) {
-      *dst8++ = *src8++;
+  }
+
+  ~ThreadNotInWasmScope() {
+    if (thread_was_in_wasm_) {
+      trap_handler::SetThreadInWasm();
     }
   }
-}
 
-// Asan on Windows triggers exceptions in this function that confuse the
-// WebAssembly trap handler, so Asan is disabled. See the comment on
-// memory_copy_wrapper above for more info.
-void memory_fill_wrapper(Address dst, uint32_t value, uint32_t size) {
-#if defined(RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS)
-  bool thread_was_in_wasm = trap_handler::IsThreadInWasm();
-  if (thread_was_in_wasm) {
-    trap_handler::ClearThreadInWasm();
+ private:
+  bool thread_was_in_wasm_;
+#else
+
+ public:
+  ThreadNotInWasmScope() {
+    // This is needed to avoid compilation errors (unused variable).
+    USE(this);
   }
 #endif
+};
 
-  // Use an explicit forward copy to match the required semantics for the
-  // memory.fill instruction. It is assumed that the caller of this function
-  // has already performed bounds checks, so {dst + size} should not overflow.
-  DCHECK(dst + size >= dst);
-  uint8_t* dst8 = reinterpret_cast<uint8_t*>(dst);
-  uint8_t value8 = static_cast<uint8_t>(value);
-  for (; size > 0; size--) {
-    *dst8++ = value8;
-  }
-#if defined(RESET_THREAD_IN_WASM_FLAG_FOR_ASAN_ON_WINDOWS)
-  if (thread_was_in_wasm) {
-    trap_handler::SetThreadInWasm();
-  }
+#ifdef DISABLE_UNTRUSTED_CODE_MITIGATIONS
+inline byte* EffectiveAddress(WasmInstanceObject instance, uint32_t index) {
+  return instance.memory_start() + index;
+}
+
+inline byte* EffectiveAddress(byte* base, size_t size, uint32_t index) {
+  return base + index;
+}
+
+#else
+inline byte* EffectiveAddress(WasmInstanceObject instance, uint32_t index) {
+  // Compute the effective address of the access, making sure to condition
+  // the index even in the in-bounds case.
+  return instance.memory_start() + (index & instance.memory_mask());
+}
+
+inline byte* EffectiveAddress(byte* base, size_t size, uint32_t index) {
+  size_t mem_mask = base::bits::RoundUpToPowerOfTwo(size) - 1;
+  return base + (index & mem_mask);
+}
 #endif
+
+template <typename V>
+V ReadAndIncrementOffset(Address data, size_t* offset) {
+  V result = ReadUnalignedValue<V>(data + *offset);
+  *offset += sizeof(V);
+  return result;
+}
+}  // namespace
+
+int32_t memory_init_wrapper(Address data) {
+  constexpr int32_t kSuccess = 1;
+  constexpr int32_t kOutOfBounds = 0;
+  ThreadNotInWasmScope thread_not_in_wasm_scope;
+  DisallowHeapAllocation disallow_heap_allocation;
+  size_t offset = 0;
+  Object raw_instance = ReadAndIncrementOffset<Object>(data, &offset);
+  WasmInstanceObject instance = WasmInstanceObject::cast(raw_instance);
+  uint32_t dst = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  uint32_t src = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  uint32_t seg_index = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  size_t size = ReadAndIncrementOffset<uint32_t>(data, &offset);
+
+  size_t mem_size = instance.memory_size();
+  if (!base::IsInBounds(dst, size, mem_size)) return kOutOfBounds;
+
+  size_t seg_size = instance.data_segment_sizes()[seg_index];
+  if (!base::IsInBounds(src, size, seg_size)) return kOutOfBounds;
+
+  byte* seg_start =
+      reinterpret_cast<byte*>(instance.data_segment_starts()[seg_index]);
+  std::memcpy(EffectiveAddress(instance, dst),
+              EffectiveAddress(seg_start, seg_size, src), size);
+  return kSuccess;
+}
+
+int32_t memory_copy_wrapper(Address data) {
+  constexpr int32_t kSuccess = 1;
+  constexpr int32_t kOutOfBounds = 0;
+  ThreadNotInWasmScope thread_not_in_wasm_scope;
+  DisallowHeapAllocation disallow_heap_allocation;
+  size_t offset = 0;
+  Object raw_instance = ReadAndIncrementOffset<Object>(data, &offset);
+  WasmInstanceObject instance = WasmInstanceObject::cast(raw_instance);
+  uint32_t dst = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  uint32_t src = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  size_t size = ReadAndIncrementOffset<uint32_t>(data, &offset);
+
+  size_t mem_size = instance.memory_size();
+  if (!base::IsInBounds(dst, size, mem_size)) return kOutOfBounds;
+  if (!base::IsInBounds(src, size, mem_size)) return kOutOfBounds;
+
+  // Use std::memmove, because the ranges can overlap.
+  std::memmove(EffectiveAddress(instance, dst), EffectiveAddress(instance, src),
+               size);
+  return kSuccess;
+}
+
+int32_t memory_fill_wrapper(Address data) {
+  constexpr int32_t kSuccess = 1;
+  constexpr int32_t kOutOfBounds = 0;
+
+  ThreadNotInWasmScope thread_not_in_wasm_scope;
+  DisallowHeapAllocation disallow_heap_allocation;
+
+  size_t offset = 0;
+  Object raw_instance = ReadAndIncrementOffset<Object>(data, &offset);
+  WasmInstanceObject instance = WasmInstanceObject::cast(raw_instance);
+  uint32_t dst = ReadAndIncrementOffset<uint32_t>(data, &offset);
+  uint8_t value =
+      static_cast<uint8_t>(ReadAndIncrementOffset<uint32_t>(data, &offset));
+  size_t size = ReadAndIncrementOffset<uint32_t>(data, &offset);
+
+  size_t mem_size = instance.memory_size();
+  if (!base::IsInBounds(dst, size, mem_size)) return kOutOfBounds;
+
+  std::memset(EffectiveAddress(instance, dst), value, size);
+  return kSuccess;
 }
 
 static WasmTrapCallbackForTesting wasm_trap_callback_for_testing = nullptr;
diff --git a/deps/v8/src/wasm/wasm-external-refs.h b/deps/v8/src/wasm/wasm-external-refs.h
index d102651702..0a2d5f3060 100644
--- a/deps/v8/src/wasm/wasm-external-refs.h
+++ b/deps/v8/src/wasm/wasm-external-refs.h
@@ -71,9 +71,17 @@ V8_EXPORT_PRIVATE void word64_ror_wrapper(Address data);
 
 V8_EXPORT_PRIVATE void float64_pow_wrapper(Address data);
 
-void memory_copy_wrapper(Address dst, Address src, uint32_t size);
+// The return type is {int32_t} instead of {bool} to enforce the compiler to
+// zero-extend the result in the return register.
+int32_t memory_init_wrapper(Address data);
 
-void memory_fill_wrapper(Address dst, uint32_t value, uint32_t size);
+// The return type is {int32_t} instead of {bool} to enforce the compiler to
+// zero-extend the result in the return register.
+int32_t memory_copy_wrapper(Address data);
+
+// The return type is {int32_t} instead of {bool} to enforce the compiler to
+// zero-extend the result in the return register.
+int32_t memory_fill_wrapper(Address data);
 
 using WasmTrapCallbackForTesting = void (*)();
 
diff --git a/deps/v8/src/wasm/wasm-import-wrapper-cache.cc b/deps/v8/src/wasm/wasm-import-wrapper-cache.cc
index 9469855ee5..a71152518a 100644
--- a/deps/v8/src/wasm/wasm-import-wrapper-cache.cc
+++ b/deps/v8/src/wasm/wasm-import-wrapper-cache.cc
@@ -24,7 +24,7 @@ WasmCode*& WasmImportWrapperCache::operator[](
 }
 
 WasmCode* WasmImportWrapperCache::Get(compiler::WasmImportCallKind kind,
-                                      FunctionSig* sig) const {
+                                      const FunctionSig* sig) const {
   base::MutexGuard lock(&mutex_);
   auto it = entry_map_.find({kind, sig});
   DCHECK(it != entry_map_.end());
diff --git a/deps/v8/src/wasm/wasm-import-wrapper-cache.h b/deps/v8/src/wasm/wasm-import-wrapper-cache.h
index 6172881dc7..39f57669cd 100644
--- a/deps/v8/src/wasm/wasm-import-wrapper-cache.h
+++ b/deps/v8/src/wasm/wasm-import-wrapper-cache.h
@@ -23,7 +23,7 @@ using FunctionSig = Signature<ValueType>;
 // Implements a cache for import wrappers.
 class WasmImportWrapperCache {
  public:
-  using CacheKey = std::pair<compiler::WasmImportCallKind, FunctionSig*>;
+  using CacheKey = std::pair<compiler::WasmImportCallKind, const FunctionSig*>;
 
   class CacheKeyHash {
    public:
@@ -51,7 +51,7 @@ class WasmImportWrapperCache {
 
   // Thread-safe. Assumes the key exists in the map.
   V8_EXPORT_PRIVATE WasmCode* Get(compiler::WasmImportCallKind kind,
-                                  FunctionSig* sig) const;
+                                  const FunctionSig* sig) const;
 
   ~WasmImportWrapperCache();
 
diff --git a/deps/v8/src/wasm/wasm-interpreter.cc b/deps/v8/src/wasm/wasm-interpreter.cc
index e8b073c2ce..b1dc8f22ef 100644
--- a/deps/v8/src/wasm/wasm-interpreter.cc
+++ b/deps/v8/src/wasm/wasm-interpreter.cc
@@ -26,6 +26,7 @@
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects-inl.h"
+#include "src/wasm/wasm-opcodes.h"
 #include "src/zone/accounting-allocator.h"
 #include "src/zone/zone-containers.h"
 
@@ -1301,12 +1302,14 @@ class ThreadImpl {
   WasmInterpreter::Thread::ExceptionHandlingResult HandleException(
       Isolate* isolate) {
     DCHECK(isolate->has_pending_exception());
+    bool catchable =
+        isolate->is_catchable_by_wasm(isolate->pending_exception());
     DCHECK_LT(0, activations_.size());
     Activation& act = activations_.back();
     while (frames_.size() > act.fp) {
       Frame& frame = frames_.back();
       InterpreterCode* code = frame.code;
-      if (code->side_table->HasEntryAt(frame.pc)) {
+      if (catchable && code->side_table->HasEntryAt(frame.pc)) {
         TRACE("----- HANDLE -----\n");
         Push(WasmValue(handle(isolate->pending_exception(), isolate)));
         isolate->clear_pending_exception();
@@ -1453,23 +1456,24 @@ class ThreadImpl {
   }
 
   pc_t InitLocals(InterpreterCode* code) {
-    for (auto p : code->locals.type_list) {
+    for (ValueType p : code->locals.type_list) {
       WasmValue val;
-      switch (p) {
+      switch (p.kind()) {
 #define CASE_TYPE(valuetype, ctype) \
-  case valuetype:                   \
+  case ValueType::valuetype:        \
     val = WasmValue(ctype{});       \
     break;
         FOREACH_WASMVALUE_CTYPES(CASE_TYPE)
 #undef CASE_TYPE
-        case kWasmAnyRef:
-        case kWasmFuncRef:
-        case kWasmNullRef:
-        case kWasmExnRef: {
+        case ValueType::kAnyRef:
+        case ValueType::kFuncRef:
+        case ValueType::kNullRef:
+        case ValueType::kExnRef: {
           val = WasmValue(isolate_->factory()->null_value());
           break;
         }
-        default:
+        case ValueType::kStmt:
+        case ValueType::kBottom:
           UNREACHABLE();
           break;
       }
@@ -1752,15 +1756,11 @@ class ThreadImpl {
   bool ExtractAtomicWaitNotifyParams(Decoder* decoder, InterpreterCode* code,
                                      pc_t pc, int* const len,
                                      uint32_t* buffer_offset, type* val,
-                                     double* timeout = nullptr) {
+                                     int64_t* timeout = nullptr) {
     MemoryAccessImmediate<Decoder::kValidate> imm(decoder, code->at(pc + 1),
                                                   sizeof(type));
     if (timeout) {
-      double timeout_ns = Pop().to<int64_t>();
-      *timeout = (timeout_ns < 0)
-                     ? V8_INFINITY
-                     : timeout_ns / (base::Time::kNanosecondsPerMicrosecond *
-                                     base::Time::kMicrosecondsPerMillisecond);
+      *timeout = Pop().to<int64_t>();
     }
     *val = Pop().to<type>();
     auto index = Pop().to<uint32_t>();
@@ -1828,7 +1828,8 @@ class ThreadImpl {
         Address src_addr =
             instance_object_->data_segment_starts()[imm.data_segment_index] +
             src;
-        memory_copy_wrapper(dst_addr, src_addr, size);
+        std::memmove(reinterpret_cast<void*>(dst_addr),
+                     reinterpret_cast<void*>(src_addr), size);
         return true;
       }
       case kExprDataDrop: {
@@ -1854,7 +1855,8 @@ class ThreadImpl {
           return false;
         }
 
-        memory_copy_wrapper(dst_addr, src_addr, size);
+        std::memmove(reinterpret_cast<void*>(dst_addr),
+                     reinterpret_cast<void*>(src_addr), size);
         return true;
       }
       case kExprMemoryFill: {
@@ -1870,7 +1872,7 @@ class ThreadImpl {
           DoTrap(kTrapMemOutOfBounds, pc);
           return false;
         }
-        memory_fill_wrapper(dst_addr, value, size);
+        std::memset(reinterpret_cast<void*>(dst_addr), value, size);
         return true;
       }
       case kExprTableInit: {
@@ -1951,12 +1953,12 @@ class ThreadImpl {
         // Even when table.fill goes out-of-bounds, as many entries as possible
         // are put into the table. Only afterwards we trap.
         uint32_t fill_count = std::min(count, table_size - start);
-        WasmTableObject::Fill(isolate_, table, start, value, fill_count);
-
         if (fill_count < count) {
           DoTrap(kTrapTableOutOfBounds, pc);
           return false;
         }
+        WasmTableObject::Fill(isolate_, table, start, value, fill_count);
+
         *len += imm.length;
         return true;
       }
@@ -2169,7 +2171,7 @@ class ThreadImpl {
         break;
       case kExprI32AtomicWait: {
         int32_t val;
-        double timeout;
+        int64_t timeout;
         uint32_t buffer_offset;
         if (!ExtractAtomicWaitNotifyParams<int32_t>(
                 decoder, code, pc, len, &buffer_offset, &val, &timeout)) {
@@ -2178,14 +2180,14 @@ class ThreadImpl {
         HandleScope handle_scope(isolate_);
         Handle<JSArrayBuffer> array_buffer(
             instance_object_->memory_object().array_buffer(), isolate_);
-        auto result = FutexEmulation::Wait32(isolate_, array_buffer,
-                                             buffer_offset, val, timeout);
+        auto result = FutexEmulation::WaitWasm32(isolate_, array_buffer,
+                                                 buffer_offset, val, timeout);
         Push(WasmValue(result.ToSmi().value()));
         break;
       }
       case kExprI64AtomicWait: {
         int64_t val;
-        double timeout;
+        int64_t timeout;
         uint32_t buffer_offset;
         if (!ExtractAtomicWaitNotifyParams<int64_t>(
                 decoder, code, pc, len, &buffer_offset, &val, &timeout)) {
@@ -2194,8 +2196,8 @@ class ThreadImpl {
         HandleScope handle_scope(isolate_);
         Handle<JSArrayBuffer> array_buffer(
             instance_object_->memory_object().array_buffer(), isolate_);
-        auto result = FutexEmulation::Wait64(isolate_, array_buffer,
-                                             buffer_offset, val, timeout);
+        auto result = FutexEmulation::WaitWasm64(isolate_, array_buffer,
+                                                 buffer_offset, val, timeout);
         Push(WasmValue(result.ToSmi().value()));
         break;
       }
@@ -2373,10 +2375,33 @@ class ThreadImpl {
       UNOP_CASE(F32x4RecipSqrtApprox, f32x4, float4, 4, base::RecipSqrt(a))
       UNOP_CASE(I64x2Neg, i64x2, int2, 2, base::NegateWithWraparound(a))
       UNOP_CASE(I32x4Neg, i32x4, int4, 4, base::NegateWithWraparound(a))
+      UNOP_CASE(I32x4Abs, i32x4, int4, 4, std::abs(a))
       UNOP_CASE(S128Not, i32x4, int4, 4, ~a)
       UNOP_CASE(I16x8Neg, i16x8, int8, 8, base::NegateWithWraparound(a))
+      UNOP_CASE(I16x8Abs, i16x8, int8, 8, std::abs(a))
       UNOP_CASE(I8x16Neg, i8x16, int16, 16, base::NegateWithWraparound(a))
+      UNOP_CASE(I8x16Abs, i8x16, int16, 16, std::abs(a))
 #undef UNOP_CASE
+
+// Cast to double in call to signbit is due to MSCV issue, see
+// https://github.com/microsoft/STL/issues/519.
+#define BITMASK_CASE(op, name, stype, count)                   \
+  case kExpr##op: {                                            \
+    WasmValue v = Pop();                                       \
+    stype s = v.to_s128().to_##name();                         \
+    int32_t res = 0;                                           \
+    for (size_t i = 0; i < count; ++i) {                       \
+      bool sign = std::signbit(static_cast<double>(s.val[i])); \
+      res |= (sign << i);                                      \
+    }                                                          \
+    Push(WasmValue(res));                                      \
+    return true;                                               \
+  }
+      BITMASK_CASE(I8x16BitMask, i8x16, int16, 16)
+      BITMASK_CASE(I16x8BitMask, i16x8, int8, 8)
+      BITMASK_CASE(I32x4BitMask, i32x4, int4, 4)
+#undef BITMASK_CASE
+
 #define CMPOP_CASE(op, name, stype, out_stype, count, expr) \
   case kExpr##op: {                                         \
     WasmValue v2 = Pop();                                   \
@@ -2827,28 +2852,28 @@ class ThreadImpl {
     sp_t base_index = StackHeight() - sig->parameter_count();
     for (size_t i = 0; i < sig->parameter_count(); ++i) {
       WasmValue value = GetStackValue(base_index + i);
-      switch (sig->GetParam(i)) {
-        case kWasmI32: {
+      switch (sig->GetParam(i).kind()) {
+        case ValueType::kI32: {
           uint32_t u32 = value.to_u32();
           EncodeI32ExceptionValue(encoded_values, &encoded_index, u32);
           break;
         }
-        case kWasmF32: {
+        case ValueType::kF32: {
           uint32_t f32 = value.to_f32_boxed().get_bits();
           EncodeI32ExceptionValue(encoded_values, &encoded_index, f32);
           break;
         }
-        case kWasmI64: {
+        case ValueType::kI64: {
           uint64_t u64 = value.to_u64();
           EncodeI64ExceptionValue(encoded_values, &encoded_index, u64);
           break;
         }
-        case kWasmF64: {
+        case ValueType::kF64: {
           uint64_t f64 = value.to_f64_boxed().get_bits();
           EncodeI64ExceptionValue(encoded_values, &encoded_index, f64);
           break;
         }
-        case kWasmS128: {
+        case ValueType::kS128: {
           int4 s128 = value.to_s128().to_i32x4();
           EncodeI32ExceptionValue(encoded_values, &encoded_index, s128.val[0]);
           EncodeI32ExceptionValue(encoded_values, &encoded_index, s128.val[1]);
@@ -2856,16 +2881,17 @@ class ThreadImpl {
           EncodeI32ExceptionValue(encoded_values, &encoded_index, s128.val[3]);
           break;
         }
-        case kWasmAnyRef:
-        case kWasmFuncRef:
-        case kWasmNullRef:
-        case kWasmExnRef: {
+        case ValueType::kAnyRef:
+        case ValueType::kFuncRef:
+        case ValueType::kNullRef:
+        case ValueType::kExnRef: {
           Handle<Object> anyref = value.to_anyref();
           DCHECK_IMPLIES(sig->GetParam(i) == kWasmNullRef, anyref->IsNull());
           encoded_values->set(encoded_index++, *anyref);
           break;
         }
-        default:
+        case ValueType::kStmt:
+        case ValueType::kBottom:
           UNREACHABLE();
       }
     }
@@ -2925,32 +2951,32 @@ class ThreadImpl {
     uint32_t encoded_index = 0;
     for (size_t i = 0; i < sig->parameter_count(); ++i) {
       WasmValue value;
-      switch (sig->GetParam(i)) {
-        case kWasmI32: {
+      switch (sig->GetParam(i).kind()) {
+        case ValueType::kI32: {
           uint32_t u32 = 0;
           DecodeI32ExceptionValue(encoded_values, &encoded_index, &u32);
           value = WasmValue(u32);
           break;
         }
-        case kWasmF32: {
+        case ValueType::kF32: {
           uint32_t f32_bits = 0;
           DecodeI32ExceptionValue(encoded_values, &encoded_index, &f32_bits);
           value = WasmValue(Float32::FromBits(f32_bits));
           break;
         }
-        case kWasmI64: {
+        case ValueType::kI64: {
           uint64_t u64 = 0;
           DecodeI64ExceptionValue(encoded_values, &encoded_index, &u64);
           value = WasmValue(u64);
           break;
         }
-        case kWasmF64: {
+        case ValueType::kF64: {
           uint64_t f64_bits = 0;
           DecodeI64ExceptionValue(encoded_values, &encoded_index, &f64_bits);
           value = WasmValue(Float64::FromBits(f64_bits));
           break;
         }
-        case kWasmS128: {
+        case ValueType::kS128: {
           int4 s128 = {0, 0, 0, 0};
           uint32_t* vals = reinterpret_cast<uint32_t*>(s128.val);
           DecodeI32ExceptionValue(encoded_values, &encoded_index, &vals[0]);
@@ -2960,16 +2986,17 @@ class ThreadImpl {
           value = WasmValue(Simd128(s128));
           break;
         }
-        case kWasmAnyRef:
-        case kWasmFuncRef:
-        case kWasmNullRef:
-        case kWasmExnRef: {
+        case ValueType::kAnyRef:
+        case ValueType::kFuncRef:
+        case ValueType::kNullRef:
+        case ValueType::kExnRef: {
           Handle<Object> anyref(encoded_values->get(encoded_index++), isolate_);
           DCHECK_IMPLIES(sig->GetParam(i) == kWasmNullRef, anyref->IsNull());
           value = WasmValue(anyref);
           break;
         }
-        default:
+        case ValueType::kStmt:
+        case ValueType::kBottom:
           UNREACHABLE();
       }
       Push(value);
@@ -3032,8 +3059,10 @@ class ThreadImpl {
       }
 
       // If max is 0, break. If max is positive (a limit is set), decrement it.
-      if (max == 0) break;
-      if (max > 0) --max;
+      if (max >= 0 && WasmOpcodes::IsBreakable(opcode)) {
+        if (max == 0) break;
+        --max;
+      }
 
       USE(skip);
       TRACE("@%-3zu: %s%-24s:", pc, skip, WasmOpcodes::OpcodeName(opcode));
@@ -3094,6 +3123,7 @@ class ThreadImpl {
         case kExprRethrow: {
           HandleScope handle_scope(isolate_);  // Avoid leaking handles.
           WasmValue ex = Pop();
+          if (ex.to_anyref()->IsNull()) return DoTrap(kTrapRethrowNullRef, pc);
           CommitPc(pc);  // Needed for local unwinding.
           if (!DoRethrowException(ex)) return;
           ReloadFromFrameOnException(&decoder, &code, &pc, &limit);
@@ -3105,6 +3135,7 @@ class ThreadImpl {
           HandleScope handle_scope(isolate_);  // Avoid leaking handles.
           WasmValue ex = Pop();
           Handle<Object> exception = ex.to_anyref();
+          if (exception->IsNull()) return DoTrap(kTrapBrOnExnNullRef, pc);
           if (MatchingExceptionTag(exception, imm.index.index)) {
             imm.index.exception = &module()->exceptions[imm.index.index];
             DoUnpackException(imm.index.exception, exception);
@@ -3408,9 +3439,9 @@ class ThreadImpl {
           GlobalIndexImmediate<Decoder::kNoValidate> imm(&decoder,
                                                          code->at(pc));
           auto& global = module()->globals[imm.index];
-          switch (global.type) {
+          switch (global.type.kind()) {
 #define CASE_TYPE(valuetype, ctype)                                     \
-  case valuetype: {                                                     \
+  case ValueType::valuetype: {                                          \
     uint8_t* ptr =                                                      \
         WasmInstanceObject::GetGlobalStorage(instance_object_, global); \
     WriteLittleEndianValue<ctype>(reinterpret_cast<Address>(ptr),       \
@@ -3419,10 +3450,10 @@ class ThreadImpl {
   }
             FOREACH_WASMVALUE_CTYPES(CASE_TYPE)
 #undef CASE_TYPE
-            case kWasmAnyRef:
-            case kWasmFuncRef:
-            case kWasmNullRef:
-            case kWasmExnRef: {
+            case ValueType::kAnyRef:
+            case ValueType::kFuncRef:
+            case ValueType::kNullRef:
+            case ValueType::kExnRef: {
               HandleScope handle_scope(isolate_);  // Avoid leaking handles.
               Handle<FixedArray> global_buffer;    // The buffer of the global.
               uint32_t global_index;               // The index into the buffer.
@@ -3434,7 +3465,8 @@ class ThreadImpl {
               global_buffer->set(global_index, *ref);
               break;
             }
-            default:
+            case ValueType::kStmt:
+            case ValueType::kBottom:
               UNREACHABLE();
           }
           len = 1 + imm.length;
@@ -3791,27 +3823,28 @@ class ThreadImpl {
     sp_t plimit = top ? top->plimit() : 0;
     sp_t llimit = top ? top->llimit() : 0;
     for (size_t i = sp; i < StackHeight(); ++i) {
-      if (i < plimit)
+      if (i < plimit) {
         PrintF(" p%zu:", i);
-      else if (i < llimit)
+      } else if (i < llimit) {
         PrintF(" l%zu:", i);
-      else
+      } else {
         PrintF(" s%zu:", i);
+      }
       WasmValue val = GetStackValue(i);
-      switch (val.type()) {
-        case kWasmI32:
+      switch (val.type().kind()) {
+        case ValueType::kI32:
           PrintF("i32:%d", val.to<int32_t>());
           break;
-        case kWasmI64:
+        case ValueType::kI64:
           PrintF("i64:%" PRId64 "", val.to<int64_t>());
           break;
-        case kWasmF32:
+        case ValueType::kF32:
           PrintF("f32:%f", val.to<float>());
           break;
-        case kWasmF64:
+        case ValueType::kF64:
           PrintF("f64:%lf", val.to<double>());
           break;
-        case kWasmS128: {
+        case ValueType::kS128: {
           // This defaults to tracing all S128 values as i32x4 values for now,
           // when there is more state to know what type of values are on the
           // stack, the right format should be printed here.
@@ -3819,7 +3852,7 @@ class ThreadImpl {
           PrintF("i32x4:%d,%d,%d,%d", s.val[0], s.val[1], s.val[2], s.val[3]);
           break;
         }
-        case kWasmAnyRef: {
+        case ValueType::kAnyRef: {
           Handle<Object> ref = val.to_anyref();
           if (ref->IsNull()) {
             PrintF("ref:null");
@@ -3828,10 +3861,15 @@ class ThreadImpl {
           }
           break;
         }
-        case kWasmStmt:
+        case ValueType::kStmt:
           PrintF("void");
           break;
-        default:
+        case ValueType::kFuncRef:
+        case ValueType::kExnRef:
+        case ValueType::kNullRef:
+          PrintF("(func|null|exn)ref:unimplemented");
+          break;
+        case ValueType::kBottom:
           UNREACHABLE();
           break;
       }
@@ -3850,7 +3888,7 @@ class ThreadImpl {
   ExternalCallResult CallExternalWasmFunction(Isolate* isolate,
                                               Handle<Object> object_ref,
                                               const WasmCode* code,
-                                              FunctionSig* sig) {
+                                              const FunctionSig* sig) {
     int num_args = static_cast<int>(sig->parameter_count());
     WasmFeatures enabled_features = WasmFeatures::FromIsolate(isolate);
 
@@ -3872,23 +3910,23 @@ class ThreadImpl {
     sp_t base_index = StackHeight() - num_args;
     for (int i = 0; i < num_args; ++i) {
       WasmValue arg = GetStackValue(base_index + i);
-      switch (sig->GetParam(i)) {
-        case kWasmI32:
+      switch (sig->GetParam(i).kind()) {
+        case ValueType::kI32:
           packer.Push(arg.to<uint32_t>());
           break;
-        case kWasmI64:
+        case ValueType::kI64:
           packer.Push(arg.to<uint64_t>());
           break;
-        case kWasmF32:
+        case ValueType::kF32:
           packer.Push(arg.to<float>());
           break;
-        case kWasmF64:
+        case ValueType::kF64:
           packer.Push(arg.to<double>());
           break;
-        case kWasmAnyRef:
-        case kWasmFuncRef:
-        case kWasmNullRef:
-        case kWasmExnRef:
+        case ValueType::kAnyRef:
+        case ValueType::kFuncRef:
+        case ValueType::kNullRef:
+        case ValueType::kExnRef:
           DCHECK_IMPLIES(sig->GetParam(i) == kWasmNullRef,
                          arg.to_anyref()->IsNull());
           packer.Push(arg.to_anyref()->ptr());
@@ -3914,23 +3952,23 @@ class ThreadImpl {
     // Push return values.
     packer.Reset();
     for (size_t i = 0; i < sig->return_count(); i++) {
-      switch (sig->GetReturn(i)) {
-        case kWasmI32:
+      switch (sig->GetReturn(i).kind()) {
+        case ValueType::kI32:
           Push(WasmValue(packer.Pop<uint32_t>()));
           break;
-        case kWasmI64:
+        case ValueType::kI64:
           Push(WasmValue(packer.Pop<uint64_t>()));
           break;
-        case kWasmF32:
+        case ValueType::kF32:
           Push(WasmValue(packer.Pop<float>()));
           break;
-        case kWasmF64:
+        case ValueType::kF64:
           Push(WasmValue(packer.Pop<double>()));
           break;
-        case kWasmAnyRef:
-        case kWasmFuncRef:
-        case kWasmNullRef:
-        case kWasmExnRef: {
+        case ValueType::kAnyRef:
+        case ValueType::kFuncRef:
+        case ValueType::kNullRef:
+        case ValueType::kExnRef: {
           Handle<Object> ref(Object(packer.Pop<Address>()), isolate);
           DCHECK_IMPLIES(sig->GetReturn(i) == kWasmNullRef, ref->IsNull());
           Push(WasmValue(ref));
@@ -3977,7 +4015,7 @@ class ThreadImpl {
     // and compiled we may get an exception.
     if (code == nullptr) return TryHandleException(isolate_);
 
-    FunctionSig* sig = module()->functions[function_index].sig;
+    const FunctionSig* sig = module()->functions[function_index].sig;
     return CallExternalWasmFunction(isolate_, object_ref, code, sig);
   }
 
@@ -4002,7 +4040,7 @@ class ThreadImpl {
       return {ExternalCallResult::SIGNATURE_MISMATCH};
     }
 
-    FunctionSig* signature = module()->signatures[sig_index];
+    const FunctionSig* signature = module()->signatures[sig_index];
     Handle<Object> object_ref = handle(entry.object_ref(), isolate_);
     WasmCode* code = GetTargetCode(isolate_, entry.target());
 
@@ -4319,7 +4357,13 @@ ControlTransferMap WasmInterpreter::ComputeControlTransfersForTesting(
   // Create some dummy structures, to avoid special-casing the implementation
   // just for testing.
   FunctionSig sig(0, 0, nullptr);
-  WasmFunction function{&sig, 0, 0, {0, 0}, false, false};
+  WasmFunction function{&sig,    // sig
+                        0,       // func_index
+                        0,       // sig_index
+                        {0, 0},  // code
+                        false,   // imported
+                        false,   // exported
+                        false};  // declared
   InterpreterCode code{
       &function, BodyLocalDecls(zone), start, end, nullptr, nullptr, nullptr};
 
diff --git a/deps/v8/src/wasm/wasm-js.cc b/deps/v8/src/wasm/wasm-js.cc
index cb1f24734f..fdc02771b4 100644
--- a/deps/v8/src/wasm/wasm-js.cc
+++ b/deps/v8/src/wasm/wasm-js.cc
@@ -24,12 +24,14 @@
 #include "src/tasks/task-utils.h"
 #include "src/trap-handler/trap-handler.h"
 #include "src/wasm/streaming-decoder.h"
+#include "src/wasm/value-type.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-limits.h"
 #include "src/wasm/wasm-objects-inl.h"
 #include "src/wasm/wasm-serialization.h"
 
 using v8::internal::wasm::ErrorThrower;
+using v8::internal::wasm::ScheduledErrorThrower;
 
 namespace v8 {
 
@@ -137,35 +139,6 @@ namespace {
     }                                                \
   } while (false)
 
-// Like an ErrorThrower, but turns all pending exceptions into scheduled
-// exceptions when going out of scope. Use this in API methods.
-// Note that pending exceptions are not necessarily created by the ErrorThrower,
-// but e.g. by the wasm start function. There might also be a scheduled
-// exception, created by another API call (e.g. v8::Object::Get). But there
-// should never be both pending and scheduled exceptions.
-class ScheduledErrorThrower : public ErrorThrower {
- public:
-  ScheduledErrorThrower(i::Isolate* isolate, const char* context)
-      : ErrorThrower(isolate, context) {}
-
-  ~ScheduledErrorThrower();
-};
-
-ScheduledErrorThrower::~ScheduledErrorThrower() {
-  // There should never be both a pending and a scheduled exception.
-  DCHECK(!isolate()->has_scheduled_exception() ||
-         !isolate()->has_pending_exception());
-  // Don't throw another error if there is already a scheduled error.
-  if (isolate()->has_scheduled_exception()) {
-    Reset();
-  } else if (isolate()->has_pending_exception()) {
-    Reset();
-    isolate()->OptionalRescheduleException(false);
-  } else if (error()) {
-    isolate()->ScheduleThrow(*Reify());
-  }
-}
-
 i::Handle<i::String> v8_str(i::Isolate* isolate, const char* str) {
   return isolate->factory()->NewStringFromAsciiChecked(str);
 }
@@ -1148,14 +1121,15 @@ void WebAssemblyMemory(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
   int64_t initial = 0;
   if (!GetInitialOrMinimumProperty(isolate, &thrower, context, descriptor,
-                                   &initial, 0, i::wasm::max_mem_pages())) {
+                                   &initial, 0,
+                                   i::wasm::max_initial_mem_pages())) {
     return;
   }
   // The descriptor's 'maximum'.
   int64_t maximum = -1;
   if (!GetOptionalIntegerProperty(isolate, &thrower, context, descriptor,
                                   v8_str(isolate, "maximum"), nullptr, &maximum,
-                                  initial, i::wasm::kSpecMaxWasmMemoryPages)) {
+                                  initial, i::wasm::max_maximum_mem_pages())) {
     return;
   }
 
@@ -1305,8 +1279,8 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
   // Convert value to a WebAssembly value, the default value is 0.
   Local<v8::Value> value = Local<Value>::Cast(args[1]);
-  switch (type) {
-    case i::wasm::kWasmI32: {
+  switch (type.kind()) {
+    case i::wasm::ValueType::kI32: {
       int32_t i32_value = 0;
       if (!value->IsUndefined()) {
         v8::Local<v8::Int32> int32_value;
@@ -1316,7 +1290,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       global_obj->SetI32(i32_value);
       break;
     }
-    case i::wasm::kWasmI64: {
+    case i::wasm::ValueType::kI64: {
       int64_t i64_value = 0;
       if (!value->IsUndefined()) {
         if (!enabled_features.has_bigint()) {
@@ -1331,7 +1305,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       global_obj->SetI64(i64_value);
       break;
     }
-    case i::wasm::kWasmF32: {
+    case i::wasm::ValueType::kF32: {
       float f32_value = 0;
       if (!value->IsUndefined()) {
         double f64_value = 0;
@@ -1343,7 +1317,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       global_obj->SetF32(f32_value);
       break;
     }
-    case i::wasm::kWasmF64: {
+    case i::wasm::ValueType::kF64: {
       double f64_value = 0;
       if (!value->IsUndefined()) {
         v8::Local<v8::Number> number_value;
@@ -1353,8 +1327,8 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       global_obj->SetF64(f64_value);
       break;
     }
-    case i::wasm::kWasmAnyRef:
-    case i::wasm::kWasmExnRef: {
+    case i::wasm::ValueType::kAnyRef:
+    case i::wasm::ValueType::kExnRef: {
       if (args.Length() < 2) {
         // When no initial value is provided, we have to use the WebAssembly
         // default value 'null', and not the JS default value 'undefined'.
@@ -1364,7 +1338,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       global_obj->SetAnyRef(Utils::OpenHandle(*value));
       break;
     }
-    case i::wasm::kWasmNullRef:
+    case i::wasm::ValueType::kNullRef:
       if (args.Length() < 2) {
         // When no initial value is provided, we have to use the WebAssembly
         // default value 'null', and not the JS default value 'undefined'.
@@ -1375,7 +1349,7 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
         thrower.TypeError("The value of nullref globals must be null");
       }
       break;
-    case i::wasm::kWasmFuncRef: {
+    case i::wasm::ValueType::kFuncRef: {
       if (args.Length() < 2) {
         // When no initial value is provided, we have to use the WebAssembly
         // default value 'null', and not the JS default value 'undefined'.
@@ -1390,7 +1364,9 @@ void WebAssemblyGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
       }
       break;
     }
-    default:
+    case i::wasm::ValueType::kStmt:
+    case i::wasm::ValueType::kS128:
+    case i::wasm::ValueType::kBottom:
       UNREACHABLE();
   }
 
@@ -1514,10 +1490,34 @@ void WebAssemblyFunction(const v8::FunctionCallbackInfo<v8::Value>& args) {
     thrower.TypeError("Argument 1 must be a function");
     return;
   }
+  const i::wasm::FunctionSig* sig = builder.Build();
 
-  i::wasm::FunctionSig* sig = builder.Build();
   i::Handle<i::JSReceiver> callable =
       Utils::OpenHandle(*args[1].As<Function>());
+  if (i::WasmExportedFunction::IsWasmExportedFunction(*callable)) {
+    if (*i::Handle<i::WasmExportedFunction>::cast(callable)->sig() == *sig) {
+      args.GetReturnValue().Set(Utils::ToLocal(callable));
+      return;
+    }
+
+    thrower.TypeError(
+        "The signature of Argument 1 (a WebAssembly function) does "
+        "not match the signature specified in Argument 0");
+    return;
+  }
+
+  if (i::WasmJSFunction::IsWasmJSFunction(*callable)) {
+    if (i::Handle<i::WasmJSFunction>::cast(callable)->MatchesSignature(sig)) {
+      args.GetReturnValue().Set(Utils::ToLocal(callable));
+      return;
+    }
+
+    thrower.TypeError(
+        "The signature of Argument 1 (a WebAssembly function) does "
+        "not match the signature specified in Argument 0");
+    return;
+  }
+
   i::Handle<i::JSFunction> result =
       i::WasmJSFunction::New(i_isolate, sig, callable);
   args.GetReturnValue().Set(Utils::ToLocal(result));
@@ -1530,7 +1530,7 @@ void WebAssemblyFunctionType(const v8::FunctionCallbackInfo<v8::Value>& args) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   ScheduledErrorThrower thrower(i_isolate, "WebAssembly.Function.type()");
 
-  i::wasm::FunctionSig* sig;
+  const i::wasm::FunctionSig* sig;
   i::Zone zone(i_isolate->allocator(), ZONE_NAME);
   i::Handle<i::Object> arg0 = Utils::OpenHandle(*args[0]);
   if (i::WasmExportedFunction::IsWasmExportedFunction(*arg0)) {
@@ -1697,8 +1697,8 @@ void WebAssemblyMemoryGrow(const v8::FunctionCallbackInfo<v8::Value>& args) {
   }
 
   uint64_t max_size64 = receiver->maximum_pages();
-  if (max_size64 > uint64_t{i::wasm::max_mem_pages()}) {
-    max_size64 = i::wasm::max_mem_pages();
+  if (max_size64 > uint64_t{i::wasm::max_maximum_mem_pages()}) {
+    max_size64 = i::wasm::max_maximum_mem_pages();
   }
   i::Handle<i::JSArrayBuffer> old_buffer(receiver->array_buffer(), i_isolate);
 
@@ -1783,11 +1783,11 @@ void WebAssemblyGlobalGetValueCommon(
 
   v8::ReturnValue<v8::Value> return_value = args.GetReturnValue();
 
-  switch (receiver->type()) {
-    case i::wasm::kWasmI32:
+  switch (receiver->type().kind()) {
+    case i::wasm::ValueType::kI32:
       return_value.Set(receiver->GetI32());
       break;
-    case i::wasm::kWasmI64: {
+    case i::wasm::ValueType::kI64: {
       auto enabled_features = i::wasm::WasmFeatures::FromIsolate(i_isolate);
       if (enabled_features.has_bigint()) {
         Local<BigInt> value = BigInt::New(isolate, receiver->GetI64());
@@ -1798,21 +1798,23 @@ void WebAssemblyGlobalGetValueCommon(
       }
       break;
     }
-    case i::wasm::kWasmF32:
+    case i::wasm::ValueType::kF32:
       return_value.Set(receiver->GetF32());
       break;
-    case i::wasm::kWasmF64:
+    case i::wasm::ValueType::kF64:
       return_value.Set(receiver->GetF64());
       break;
-    case i::wasm::kWasmAnyRef:
-    case i::wasm::kWasmFuncRef:
-    case i::wasm::kWasmNullRef:
-    case i::wasm::kWasmExnRef:
+    case i::wasm::ValueType::kAnyRef:
+    case i::wasm::ValueType::kFuncRef:
+    case i::wasm::ValueType::kNullRef:
+    case i::wasm::ValueType::kExnRef:
       DCHECK_IMPLIES(receiver->type() == i::wasm::kWasmNullRef,
                      receiver->GetRef()->IsNull());
       return_value.Set(Utils::ToLocal(receiver->GetRef()));
       break;
-    default:
+    case i::wasm::ValueType::kBottom:
+    case i::wasm::ValueType::kStmt:
+    case i::wasm::ValueType::kS128:
       UNREACHABLE();
   }
 }
@@ -1847,14 +1849,14 @@ void WebAssemblyGlobalSetValue(
     return;
   }
 
-  switch (receiver->type()) {
-    case i::wasm::kWasmI32: {
+  switch (receiver->type().kind()) {
+    case i::wasm::ValueType::kI32: {
       int32_t i32_value = 0;
       if (!args[0]->Int32Value(context).To(&i32_value)) return;
       receiver->SetI32(i32_value);
       break;
     }
-    case i::wasm::kWasmI64: {
+    case i::wasm::ValueType::kI64: {
       auto enabled_features = i::wasm::WasmFeatures::FromIsolate(i_isolate);
       if (enabled_features.has_bigint()) {
         v8::Local<v8::BigInt> bigint_value;
@@ -1865,29 +1867,29 @@ void WebAssemblyGlobalSetValue(
       }
       break;
     }
-    case i::wasm::kWasmF32: {
+    case i::wasm::ValueType::kF32: {
       double f64_value = 0;
       if (!args[0]->NumberValue(context).To(&f64_value)) return;
       receiver->SetF32(i::DoubleToFloat32(f64_value));
       break;
     }
-    case i::wasm::kWasmF64: {
+    case i::wasm::ValueType::kF64: {
       double f64_value = 0;
       if (!args[0]->NumberValue(context).To(&f64_value)) return;
       receiver->SetF64(f64_value);
       break;
     }
-    case i::wasm::kWasmAnyRef:
-    case i::wasm::kWasmExnRef: {
+    case i::wasm::ValueType::kAnyRef:
+    case i::wasm::ValueType::kExnRef: {
       receiver->SetAnyRef(Utils::OpenHandle(*args[0]));
       break;
     }
-    case i::wasm::kWasmNullRef:
+    case i::wasm::ValueType::kNullRef:
       if (!receiver->SetNullRef(Utils::OpenHandle(*args[0]))) {
         thrower.TypeError("The value of nullref must be null");
       }
       break;
-    case i::wasm::kWasmFuncRef: {
+    case i::wasm::ValueType::kFuncRef: {
       if (!receiver->SetFuncRef(i_isolate, Utils::OpenHandle(*args[0]))) {
         thrower.TypeError(
             "value of an anyfunc reference must be either null or an "
@@ -1895,7 +1897,9 @@ void WebAssemblyGlobalSetValue(
       }
       break;
     }
-    default:
+    case i::wasm::ValueType::kBottom:
+    case i::wasm::ValueType::kStmt:
+    case i::wasm::ValueType::kS128:
       UNREACHABLE();
   }
 }
diff --git a/deps/v8/src/wasm/wasm-limits.h b/deps/v8/src/wasm/wasm-limits.h
index 5206ad6212..02303fb69d 100644
--- a/deps/v8/src/wasm/wasm-limits.h
+++ b/deps/v8/src/wasm/wasm-limits.h
@@ -9,13 +9,17 @@
 #include <cstdint>
 #include <limits>
 
+#include "src/base/macros.h"
 #include "src/wasm/wasm-constants.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
-constexpr size_t kSpecMaxWasmMemoryPages = 65536;
+// These two constants are defined in the Wasm JS API spec and as such only
+// concern JS embeddings.
+constexpr size_t kSpecMaxWasmInitialMemoryPages = 32767;
+constexpr size_t kSpecMaxWasmMaximumMemoryPages = 65536;
 
 // The following limits are imposed by V8 on WebAssembly modules.
 // The limits are agreed upon with other engines for consistency.
@@ -27,7 +31,9 @@ constexpr size_t kV8MaxWasmGlobals = 1000000;
 constexpr size_t kV8MaxWasmExceptions = 1000000;
 constexpr size_t kV8MaxWasmExceptionTypes = 1000000;
 constexpr size_t kV8MaxWasmDataSegments = 100000;
-// Don't use this limit directly, but use the value of {max_mem_pages()}.
+// This indicates the maximum memory size our implementation supports.
+// Don't use this limit directly; use {max_initial_mem_pages()} instead
+// to take the spec'ed limit as well as command line flag into account.
 constexpr size_t kV8MaxWasmMemoryPages = 65536;  // = 4 GiB
 constexpr size_t kV8MaxWasmStringSize = 100000;
 constexpr size_t kV8MaxWasmModuleSize = 1024 * 1024 * 1024;  // = 1 GiB
@@ -43,8 +49,6 @@ constexpr size_t kV8MaxWasmTableInitEntries = 10000000;
 constexpr size_t kV8MaxWasmTables = 1;
 constexpr size_t kV8MaxWasmMemories = 1;
 
-static_assert(kV8MaxWasmMemoryPages <= kSpecMaxWasmMemoryPages,
-              "v8 should not be more permissive than the spec");
 static_assert(kV8MaxWasmTableSize <= 4294967295,  // 2^32 - 1
               "v8 should not exceed WebAssembly's non-web embedding limits");
 static_assert(kV8MaxWasmTableInitEntries <= kV8MaxWasmTableSize,
@@ -58,11 +62,12 @@ constexpr uint64_t kWasmMaxHeapOffset =
 // Defined in wasm-engine.cc.
 // TODO(wasm): Make this size_t for wasm64. Currently the --wasm-max-mem-pages
 // flag is only uint32_t.
-V8_EXPORT_PRIVATE uint32_t max_mem_pages();
+V8_EXPORT_PRIVATE uint32_t max_initial_mem_pages();
+V8_EXPORT_PRIVATE uint32_t max_maximum_mem_pages();
 uint32_t max_table_init_entries();
 
 inline uint64_t max_mem_bytes() {
-  return uint64_t{max_mem_pages()} * kWasmPageSize;
+  return uint64_t{max_maximum_mem_pages()} * kWasmPageSize;
 }
 
 }  // namespace wasm
diff --git a/deps/v8/src/wasm/wasm-linkage.h b/deps/v8/src/wasm/wasm-linkage.h
index 1bd32ef561..7e56ea6eae 100644
--- a/deps/v8/src/wasm/wasm-linkage.h
+++ b/deps/v8/src/wasm/wasm-linkage.h
@@ -15,7 +15,7 @@ namespace internal {
 namespace wasm {
 
 // TODO(wasm): optimize calling conventions to be both closer to C++ (to
-// reduce adapter costs for fast WASM <-> C++ calls) and to be more efficient
+// reduce adapter costs for fast Wasm <-> C++ calls) and to be more efficient
 // in general.
 
 #if V8_TARGET_ARCH_IA32
diff --git a/deps/v8/src/wasm/wasm-memory.cc b/deps/v8/src/wasm/wasm-memory.cc
deleted file mode 100644
index bbb0d67f9c..0000000000
--- a/deps/v8/src/wasm/wasm-memory.cc
+++ /dev/null
@@ -1,633 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <limits>
-
-#include "src/heap/heap-inl.h"
-#include "src/logging/counters.h"
-#include "src/objects/js-array-buffer-inl.h"
-#include "src/objects/objects-inl.h"
-#include "src/wasm/wasm-engine.h"
-#include "src/wasm/wasm-limits.h"
-#include "src/wasm/wasm-memory.h"
-#include "src/wasm/wasm-module.h"
-
-namespace v8 {
-namespace internal {
-namespace wasm {
-
-namespace {
-
-constexpr size_t kNegativeGuardSize = 1u << 31;  // 2GiB
-
-void AddAllocationStatusSample(Isolate* isolate,
-                               WasmMemoryTracker::AllocationStatus status) {
-  isolate->counters()->wasm_memory_allocation_result()->AddSample(
-      static_cast<int>(status));
-}
-
-bool RunWithGCAndRetry(const std::function<bool()>& fn, Heap* heap,
-                       bool* did_retry) {
-  // Try up to three times; getting rid of dead JSArrayBuffer allocations might
-  // require two GCs because the first GC maybe incremental and may have
-  // floating garbage.
-  static constexpr int kAllocationRetries = 2;
-
-  for (int trial = 0;; ++trial) {
-    if (fn()) return true;
-    // {fn} failed. If {kAllocationRetries} is reached, fail.
-    *did_retry = true;
-    if (trial == kAllocationRetries) return false;
-    // Otherwise, collect garbage and retry.
-    // TODO(wasm): Since reservation limits are engine-wide, we should do an
-    // engine-wide GC here (i.e. trigger a GC in each isolate using the engine,
-    // and wait for them all to finish). See https://crbug.com/v8/9405.
-    heap->MemoryPressureNotification(MemoryPressureLevel::kCritical, true);
-  }
-}
-
-void* TryAllocateBackingStore(WasmMemoryTracker* memory_tracker, Heap* heap,
-                              size_t size, size_t max_size,
-                              void** allocation_base,
-                              size_t* allocation_length) {
-  using AllocationStatus = WasmMemoryTracker::AllocationStatus;
-#if V8_TARGET_ARCH_64_BIT
-  constexpr bool kRequireFullGuardRegions = true;
-#else
-  constexpr bool kRequireFullGuardRegions = false;
-#endif
-  // Let the WasmMemoryTracker know we are going to reserve a bunch of
-  // address space.
-  size_t reservation_size = std::max(max_size, size);
-  bool did_retry = false;
-
-  auto reserve_memory_space = [&] {
-    // For guard regions, we always allocate the largest possible offset
-    // into the heap, so the addressable memory after the guard page can
-    // be made inaccessible.
-    //
-    // To protect against 32-bit integer overflow issues, we also
-    // protect the 2GiB before the valid part of the memory buffer.
-    *allocation_length =
-        kRequireFullGuardRegions
-            ? RoundUp(kWasmMaxHeapOffset + kNegativeGuardSize, CommitPageSize())
-            : RoundUp(base::bits::RoundUpToPowerOfTwo(reservation_size),
-                      kWasmPageSize);
-    DCHECK_GE(*allocation_length, size);
-    DCHECK_GE(*allocation_length, kWasmPageSize);
-
-    return memory_tracker->ReserveAddressSpace(*allocation_length);
-  };
-  if (!RunWithGCAndRetry(reserve_memory_space, heap, &did_retry)) {
-    // Reset reservation_size to initial size so that at least the initial size
-    // can be allocated if maximum size reservation is not possible.
-    reservation_size = size;
-
-    // We are over the address space limit. Fail.
-    //
-    // When running under the correctness fuzzer (i.e.
-    // --correctness-fuzzer-suppressions is preset), we crash
-    // instead so it is not incorrectly reported as a correctness
-    // violation. See https://crbug.com/828293#c4
-    if (FLAG_correctness_fuzzer_suppressions) {
-      FATAL("could not allocate wasm memory");
-    }
-    AddAllocationStatusSample(
-        heap->isolate(), AllocationStatus::kAddressSpaceLimitReachedFailure);
-    return nullptr;
-  }
-
-  // The Reserve makes the whole region inaccessible by default.
-  DCHECK_NULL(*allocation_base);
-  auto allocate_pages = [&] {
-    *allocation_base =
-        AllocatePages(GetPlatformPageAllocator(), nullptr, *allocation_length,
-                      kWasmPageSize, PageAllocator::kNoAccess);
-    return *allocation_base != nullptr;
-  };
-  if (!RunWithGCAndRetry(allocate_pages, heap, &did_retry)) {
-    memory_tracker->ReleaseReservation(*allocation_length);
-    AddAllocationStatusSample(heap->isolate(), AllocationStatus::kOtherFailure);
-    return nullptr;
-  }
-
-  byte* memory = reinterpret_cast<byte*>(*allocation_base);
-  if (kRequireFullGuardRegions) {
-    memory += kNegativeGuardSize;
-  }
-
-  // Make the part we care about accessible.
-  auto commit_memory = [&] {
-    return size == 0 || SetPermissions(GetPlatformPageAllocator(), memory,
-                                       RoundUp(size, kWasmPageSize),
-                                       PageAllocator::kReadWrite);
-  };
-  // SetPermissions commits the extra memory, which may put us over the
-  // process memory limit. If so, report this as an OOM.
-  if (!RunWithGCAndRetry(commit_memory, heap, &did_retry)) {
-    V8::FatalProcessOutOfMemory(nullptr, "TryAllocateBackingStore");
-  }
-
-  memory_tracker->RegisterAllocation(heap->isolate(), *allocation_base,
-                                     *allocation_length, memory, size);
-  AddAllocationStatusSample(heap->isolate(),
-                            did_retry ? AllocationStatus::kSuccessAfterRetry
-                                      : AllocationStatus::kSuccess);
-  return memory;
-}
-
-#if V8_TARGET_ARCH_MIPS64
-// MIPS64 has a user space of 2^40 bytes on most processors,
-// address space limits needs to be smaller.
-constexpr size_t kAddressSpaceLimit = 0x8000000000L;  // 512 GiB
-#elif V8_TARGET_ARCH_64_BIT
-constexpr size_t kAddressSpaceLimit = 0x10100000000L;  // 1 TiB + 4 GiB
-#else
-constexpr size_t kAddressSpaceLimit = 0xC0000000;  // 3 GiB
-#endif
-
-}  // namespace
-
-WasmMemoryTracker::~WasmMemoryTracker() {
-  // All reserved address space should be released before the allocation tracker
-  // is destroyed.
-  DCHECK_EQ(reserved_address_space_, 0u);
-  DCHECK_EQ(allocated_address_space_, 0u);
-  DCHECK(allocations_.empty());
-}
-
-void* WasmMemoryTracker::TryAllocateBackingStoreForTesting(
-    Heap* heap, size_t size, void** allocation_base,
-    size_t* allocation_length) {
-  return TryAllocateBackingStore(this, heap, size, size, allocation_base,
-                                 allocation_length);
-}
-
-void WasmMemoryTracker::FreeBackingStoreForTesting(base::AddressRegion memory,
-                                                   void* buffer_start) {
-  base::MutexGuard scope_lock(&mutex_);
-  ReleaseAllocation_Locked(nullptr, buffer_start);
-  CHECK(FreePages(GetPlatformPageAllocator(),
-                  reinterpret_cast<void*>(memory.begin()), memory.size()));
-}
-
-bool WasmMemoryTracker::ReserveAddressSpace(size_t num_bytes) {
-  size_t reservation_limit = kAddressSpaceLimit;
-  while (true) {
-    size_t old_count = reserved_address_space_.load();
-    if (old_count > reservation_limit) return false;
-    if (reservation_limit - old_count < num_bytes) return false;
-    if (reserved_address_space_.compare_exchange_weak(old_count,
-                                                      old_count + num_bytes)) {
-      return true;
-    }
-  }
-}
-
-void WasmMemoryTracker::ReleaseReservation(size_t num_bytes) {
-  size_t const old_reserved = reserved_address_space_.fetch_sub(num_bytes);
-  USE(old_reserved);
-  DCHECK_LE(num_bytes, old_reserved);
-}
-
-void WasmMemoryTracker::RegisterAllocation(Isolate* isolate,
-                                           void* allocation_base,
-                                           size_t allocation_length,
-                                           void* buffer_start,
-                                           size_t buffer_length) {
-  base::MutexGuard scope_lock(&mutex_);
-
-  allocated_address_space_ += allocation_length;
-  // Report address space usage in MiB so the full range fits in an int on all
-  // platforms.
-  isolate->counters()->wasm_address_space_usage_mb()->AddSample(
-      static_cast<int>(allocated_address_space_ / MB));
-
-  allocations_.emplace(buffer_start,
-                       AllocationData{allocation_base, allocation_length,
-                                      buffer_start, buffer_length});
-}
-
-WasmMemoryTracker::AllocationData WasmMemoryTracker::ReleaseAllocation_Locked(
-    Isolate* isolate, const void* buffer_start) {
-  auto find_result = allocations_.find(buffer_start);
-  CHECK_NE(find_result, allocations_.end());
-
-  size_t num_bytes = find_result->second.allocation_length;
-  DCHECK_LE(num_bytes, reserved_address_space_);
-  DCHECK_LE(num_bytes, allocated_address_space_);
-  reserved_address_space_ -= num_bytes;
-  allocated_address_space_ -= num_bytes;
-
-  AllocationData allocation_data = find_result->second;
-  allocations_.erase(find_result);
-  return allocation_data;
-}
-
-const WasmMemoryTracker::AllocationData* WasmMemoryTracker::FindAllocationData(
-    const void* buffer_start) {
-  base::MutexGuard scope_lock(&mutex_);
-  const auto& result = allocations_.find(buffer_start);
-  if (result != allocations_.end()) {
-    return &result->second;
-  }
-  return nullptr;
-}
-
-bool WasmMemoryTracker::IsWasmMemory(const void* buffer_start) {
-  base::MutexGuard scope_lock(&mutex_);
-  return allocations_.find(buffer_start) != allocations_.end();
-}
-
-bool WasmMemoryTracker::IsWasmSharedMemory(const void* buffer_start) {
-  base::MutexGuard scope_lock(&mutex_);
-  const auto& result = allocations_.find(buffer_start);
-  // Should be a wasm allocation, and registered as a shared allocation.
-  return (result != allocations_.end() && result->second.is_shared);
-}
-
-void WasmMemoryTracker::MarkWasmMemoryNotGrowable(
-    Handle<JSArrayBuffer> buffer) {
-  base::MutexGuard scope_lock(&mutex_);
-  const auto& allocation = allocations_.find(buffer->backing_store());
-  if (allocation == allocations_.end()) return;
-  allocation->second.is_growable = false;
-}
-
-bool WasmMemoryTracker::IsWasmMemoryGrowable(Handle<JSArrayBuffer> buffer) {
-  base::MutexGuard scope_lock(&mutex_);
-  if (buffer->backing_store() == nullptr) return true;
-  const auto& allocation = allocations_.find(buffer->backing_store());
-  if (allocation == allocations_.end()) return false;
-  return allocation->second.is_growable;
-}
-
-bool WasmMemoryTracker::FreeWasmMemory(Isolate* isolate,
-                                       const void* buffer_start) {
-  base::MutexGuard scope_lock(&mutex_);
-  const auto& result = allocations_.find(buffer_start);
-  if (result == allocations_.end()) return false;
-  if (result->second.is_shared) {
-    // This is a shared WebAssembly.Memory allocation
-    FreeMemoryIfNotShared_Locked(isolate, buffer_start);
-    return true;
-  }
-  // This is a WebAssembly.Memory allocation
-  const AllocationData allocation =
-      ReleaseAllocation_Locked(isolate, buffer_start);
-  CHECK(FreePages(GetPlatformPageAllocator(), allocation.allocation_base,
-                  allocation.allocation_length));
-  return true;
-}
-
-void WasmMemoryTracker::RegisterWasmMemoryAsShared(
-    Handle<WasmMemoryObject> object, Isolate* isolate) {
-  // Only register with the tracker if shared grow is enabled.
-  if (!FLAG_wasm_grow_shared_memory) return;
-  const void* backing_store = object->array_buffer().backing_store();
-  // TODO(V8:8810): This should be a DCHECK, currently some tests do not
-  // use a full WebAssembly.Memory, and fail on registering so return early.
-  if (!IsWasmMemory(backing_store)) return;
-  {
-    base::MutexGuard scope_lock(&mutex_);
-    // Register as shared allocation when it is post messaged. This happens only
-    // the first time a buffer is shared over Postmessage, and track all the
-    // memory objects that are associated with this backing store.
-    RegisterSharedWasmMemory_Locked(object, isolate);
-    // Add isolate to backing store mapping.
-    isolates_per_buffer_[backing_store].emplace(isolate);
-  }
-}
-
-void WasmMemoryTracker::SetPendingUpdateOnGrow(Handle<JSArrayBuffer> old_buffer,
-                                               size_t new_size) {
-  base::MutexGuard scope_lock(&mutex_);
-  // Keep track of the new size of the buffer associated with each backing
-  // store.
-  AddBufferToGrowMap_Locked(old_buffer, new_size);
-  // Request interrupt to GROW_SHARED_MEMORY to other isolates
-  TriggerSharedGrowInterruptOnAllIsolates_Locked(old_buffer);
-}
-
-void WasmMemoryTracker::UpdateSharedMemoryInstances(Isolate* isolate) {
-  base::MutexGuard scope_lock(&mutex_);
-  // For every buffer in the grow_entry_map_, update the size for all the
-  // memory objects associated with this isolate.
-  for (auto it = grow_update_map_.begin(); it != grow_update_map_.end();) {
-    UpdateSharedMemoryStateOnInterrupt_Locked(isolate, it->first, it->second);
-    // If all the isolates that share this buffer have hit a stack check, their
-    // memory objects are updated, and this grow entry can be erased.
-    if (AreAllIsolatesUpdated_Locked(it->first)) {
-      it = grow_update_map_.erase(it);
-    } else {
-      it++;
-    }
-  }
-}
-
-void WasmMemoryTracker::RegisterSharedWasmMemory_Locked(
-    Handle<WasmMemoryObject> object, Isolate* isolate) {
-  DCHECK(object->array_buffer().is_shared());
-
-  void* backing_store = object->array_buffer().backing_store();
-  // The allocation of a WasmMemoryObject should always be registered with the
-  // WasmMemoryTracker.
-  const auto& result = allocations_.find(backing_store);
-  if (result == allocations_.end()) return;
-
-  // Register the allocation as shared, if not alreadt marked as shared.
-  if (!result->second.is_shared) result->second.is_shared = true;
-
-  // Create persistent global handles for the memory objects that are shared
-  GlobalHandles* global_handles = isolate->global_handles();
-  object = global_handles->Create(*object);
-
-  // Add to memory_object_vector to track memory objects, instance objects
-  // that will need to be updated on a Grow call
-  result->second.memory_object_vector.push_back(
-      SharedMemoryObjectState(object, isolate));
-}
-
-void WasmMemoryTracker::AddBufferToGrowMap_Locked(
-    Handle<JSArrayBuffer> old_buffer, size_t new_size) {
-  void* backing_store = old_buffer->backing_store();
-  auto entry = grow_update_map_.find(old_buffer->backing_store());
-  if (entry == grow_update_map_.end()) {
-    // No pending grow for this backing store, add to map.
-    grow_update_map_.emplace(backing_store, new_size);
-    return;
-  }
-  // If grow on the same buffer is requested before the update is complete,
-  // the new_size should always be greater or equal to the old_size. Equal
-  // in the case that grow(0) is called, but new buffer handles are mandated
-  // by the Spec.
-  CHECK_LE(entry->second, new_size);
-  entry->second = new_size;
-  // Flush instances_updated everytime a new grow size needs to be updates
-  ClearUpdatedInstancesOnPendingGrow_Locked(backing_store);
-}
-
-void WasmMemoryTracker::TriggerSharedGrowInterruptOnAllIsolates_Locked(
-    Handle<JSArrayBuffer> old_buffer) {
-  // Request a GrowShareMemory interrupt on all the isolates that share
-  // the backing store.
-  const auto& isolates = isolates_per_buffer_.find(old_buffer->backing_store());
-  for (const auto& isolate : isolates->second) {
-    isolate->stack_guard()->RequestGrowSharedMemory();
-  }
-}
-
-void WasmMemoryTracker::UpdateSharedMemoryStateOnInterrupt_Locked(
-    Isolate* isolate, void* backing_store, size_t new_size) {
-  // Update objects only if there are memory objects that share this backing
-  // store, and this isolate is marked as one of the isolates that shares this
-  // buffer.
-  if (MemoryObjectsNeedUpdate_Locked(isolate, backing_store)) {
-    UpdateMemoryObjectsForIsolate_Locked(isolate, backing_store, new_size);
-    // As the memory objects are updated, add this isolate to a set of isolates
-    // that are updated on grow. This state is maintained to track if all the
-    // isolates that share the backing store have hit a StackCheck.
-    isolates_updated_on_grow_[backing_store].emplace(isolate);
-  }
-}
-
-bool WasmMemoryTracker::AreAllIsolatesUpdated_Locked(
-    const void* backing_store) {
-  const auto& buffer_isolates = isolates_per_buffer_.find(backing_store);
-  // No isolates share this buffer.
-  if (buffer_isolates == isolates_per_buffer_.end()) return true;
-  const auto& updated_isolates = isolates_updated_on_grow_.find(backing_store);
-  // Some isolates share the buffer, but no isolates have been updated yet.
-  if (updated_isolates == isolates_updated_on_grow_.end()) return false;
-  if (buffer_isolates->second == updated_isolates->second) {
-    // If all the isolates that share this backing_store have hit a stack check,
-    // and the memory objects have been updated, remove the entry from the
-    // updatemap, and return true.
-    isolates_updated_on_grow_.erase(backing_store);
-    return true;
-  }
-  return false;
-}
-
-void WasmMemoryTracker::ClearUpdatedInstancesOnPendingGrow_Locked(
-    const void* backing_store) {
-  // On multiple grows to the same buffer, the entries for that buffer should be
-  // flushed. This is done so that any consecutive grows to the same buffer will
-  // update all instances that share this buffer.
-  const auto& value = isolates_updated_on_grow_.find(backing_store);
-  if (value != isolates_updated_on_grow_.end()) {
-    value->second.clear();
-  }
-}
-
-void WasmMemoryTracker::UpdateMemoryObjectsForIsolate_Locked(
-    Isolate* isolate, void* backing_store, size_t new_size) {
-  const auto& result = allocations_.find(backing_store);
-  if (result == allocations_.end() || !result->second.is_shared) return;
-  for (const auto& memory_obj_state : result->second.memory_object_vector) {
-    DCHECK_NE(memory_obj_state.isolate, nullptr);
-    if (isolate == memory_obj_state.isolate) {
-      HandleScope scope(isolate);
-      Handle<WasmMemoryObject> memory_object = memory_obj_state.memory_object;
-      DCHECK(memory_object->IsWasmMemoryObject());
-      DCHECK(memory_object->array_buffer().is_shared());
-      // Permissions adjusted, but create a new buffer with new size
-      // and old attributes. Buffer has already been allocated,
-      // just create a new buffer with same backing store.
-      bool is_external = memory_object->array_buffer().is_external();
-      Handle<JSArrayBuffer> new_buffer = SetupArrayBuffer(
-          isolate, backing_store, new_size, is_external, SharedFlag::kShared);
-      memory_obj_state.memory_object->update_instances(isolate, new_buffer);
-    }
-  }
-}
-
-bool WasmMemoryTracker::MemoryObjectsNeedUpdate_Locked(
-    Isolate* isolate, const void* backing_store) {
-  // Return true if this buffer has memory_objects it needs to update.
-  const auto& result = allocations_.find(backing_store);
-  if (result == allocations_.end() || !result->second.is_shared) return false;
-  // Only update if the buffer has memory objects that need to be updated.
-  if (result->second.memory_object_vector.empty()) return false;
-  const auto& isolate_entry = isolates_per_buffer_.find(backing_store);
-  return (isolate_entry != isolates_per_buffer_.end() &&
-          isolate_entry->second.count(isolate) != 0);
-}
-
-void WasmMemoryTracker::FreeMemoryIfNotShared_Locked(
-    Isolate* isolate, const void* backing_store) {
-  RemoveSharedBufferState_Locked(isolate, backing_store);
-  if (CanFreeSharedMemory_Locked(backing_store)) {
-    const AllocationData allocation =
-        ReleaseAllocation_Locked(isolate, backing_store);
-    CHECK(FreePages(GetPlatformPageAllocator(), allocation.allocation_base,
-                    allocation.allocation_length));
-  }
-}
-
-bool WasmMemoryTracker::CanFreeSharedMemory_Locked(const void* backing_store) {
-  const auto& value = isolates_per_buffer_.find(backing_store);
-  // If no isolates share this buffer, backing store can be freed.
-  // Erase the buffer entry.
-  if (value == isolates_per_buffer_.end() || value->second.empty()) return true;
-  return false;
-}
-
-void WasmMemoryTracker::RemoveSharedBufferState_Locked(
-    Isolate* isolate, const void* backing_store) {
-  if (isolate != nullptr) {
-    DestroyMemoryObjectsAndRemoveIsolateEntry_Locked(isolate, backing_store);
-    RemoveIsolateFromBackingStore_Locked(isolate, backing_store);
-  } else {
-    // This happens for externalized contents cleanup shared memory state
-    // associated with this buffer across isolates.
-    DestroyMemoryObjectsAndRemoveIsolateEntry_Locked(backing_store);
-  }
-}
-
-void WasmMemoryTracker::DestroyMemoryObjectsAndRemoveIsolateEntry_Locked(
-    const void* backing_store) {
-  const auto& result = allocations_.find(backing_store);
-  CHECK(result != allocations_.end() && result->second.is_shared);
-  auto& object_vector = result->second.memory_object_vector;
-  if (object_vector.empty()) return;
-  for (const auto& mem_obj_state : object_vector) {
-    GlobalHandles::Destroy(mem_obj_state.memory_object.location());
-  }
-  object_vector.clear();
-  // Remove isolate from backing store map.
-  isolates_per_buffer_.erase(backing_store);
-}
-
-void WasmMemoryTracker::DestroyMemoryObjectsAndRemoveIsolateEntry_Locked(
-    Isolate* isolate, const void* backing_store) {
-  // This gets called when an internal handle to the ArrayBuffer should be
-  // freed, on heap tear down for that isolate, remove the memory objects
-  // that are associated with this buffer and isolate.
-  const auto& result = allocations_.find(backing_store);
-  CHECK(result != allocations_.end() && result->second.is_shared);
-  auto& object_vector = result->second.memory_object_vector;
-  if (object_vector.empty()) return;
-  for (auto it = object_vector.begin(); it != object_vector.end();) {
-    if (isolate == it->isolate) {
-      GlobalHandles::Destroy(it->memory_object.location());
-      it = object_vector.erase(it);
-    } else {
-      ++it;
-    }
-  }
-}
-
-void WasmMemoryTracker::RemoveIsolateFromBackingStore_Locked(
-    Isolate* isolate, const void* backing_store) {
-  const auto& isolates = isolates_per_buffer_.find(backing_store);
-  if (isolates == isolates_per_buffer_.end() || isolates->second.empty())
-    return;
-  isolates->second.erase(isolate);
-}
-
-void WasmMemoryTracker::DeleteSharedMemoryObjectsOnIsolate(Isolate* isolate) {
-  base::MutexGuard scope_lock(&mutex_);
-  // This is possible for buffers that are externalized, and their handles have
-  // been freed, the backing store wasn't released because externalized contents
-  // were using it.
-  if (isolates_per_buffer_.empty()) return;
-  for (auto& entry : isolates_per_buffer_) {
-    if (entry.second.find(isolate) == entry.second.end()) continue;
-    const void* backing_store = entry.first;
-    entry.second.erase(isolate);
-    DestroyMemoryObjectsAndRemoveIsolateEntry_Locked(isolate, backing_store);
-  }
-  for (auto& buffer_isolates : isolates_updated_on_grow_) {
-    auto& isolates = buffer_isolates.second;
-    isolates.erase(isolate);
-  }
-}
-
-Handle<JSArrayBuffer> SetupArrayBuffer(Isolate* isolate, void* backing_store,
-                                       size_t size, bool is_external,
-                                       SharedFlag shared) {
-  Handle<JSArrayBuffer> buffer =
-      isolate->factory()->NewJSArrayBuffer(shared, AllocationType::kOld);
-  constexpr bool is_wasm_memory = true;
-  JSArrayBuffer::Setup(buffer, isolate, is_external, backing_store, size,
-                       shared, is_wasm_memory);
-  buffer->set_is_detachable(false);
-  return buffer;
-}
-
-MaybeHandle<JSArrayBuffer> AllocateAndSetupArrayBuffer(Isolate* isolate,
-                                                       size_t size,
-                                                       size_t maximum_size,
-                                                       SharedFlag shared) {
-  // Enforce flag-limited maximum allocation size.
-  if (size > max_mem_bytes()) return {};
-
-  WasmMemoryTracker* memory_tracker = isolate->wasm_engine()->memory_tracker();
-
-  // Set by TryAllocateBackingStore.
-  void* allocation_base = nullptr;
-  size_t allocation_length = 0;
-
-  void* memory = TryAllocateBackingStore(memory_tracker, isolate->heap(), size,
-                                         maximum_size, &allocation_base,
-                                         &allocation_length);
-  if (memory == nullptr) return {};
-
-#if DEBUG
-  // Double check the API allocator actually zero-initialized the memory.
-  const byte* bytes = reinterpret_cast<const byte*>(memory);
-  for (size_t i = 0; i < size; ++i) {
-    DCHECK_EQ(0, bytes[i]);
-  }
-#endif
-
-  reinterpret_cast<v8::Isolate*>(isolate)
-      ->AdjustAmountOfExternalAllocatedMemory(size);
-
-  constexpr bool is_external = false;
-  return SetupArrayBuffer(isolate, memory, size, is_external, shared);
-}
-
-MaybeHandle<JSArrayBuffer> NewArrayBuffer(Isolate* isolate, size_t size) {
-  return AllocateAndSetupArrayBuffer(isolate, size, size,
-                                     SharedFlag::kNotShared);
-}
-
-MaybeHandle<JSArrayBuffer> NewSharedArrayBuffer(Isolate* isolate,
-                                                size_t initial_size,
-                                                size_t max_size) {
-  return AllocateAndSetupArrayBuffer(isolate, initial_size, max_size,
-                                     SharedFlag::kShared);
-}
-
-void DetachMemoryBuffer(Isolate* isolate, Handle<JSArrayBuffer> buffer,
-                        bool free_memory) {
-  if (buffer->is_shared()) return;  // Detaching shared buffers is impossible.
-  DCHECK(!buffer->is_detachable());
-
-  const bool is_external = buffer->is_external();
-  DCHECK(!buffer->is_detachable());
-  if (!is_external) {
-    buffer->set_is_external(true);
-    isolate->heap()->UnregisterArrayBuffer(*buffer);
-    if (free_memory) {
-      // We need to free the memory before detaching the buffer because
-      // FreeBackingStore reads buffer->allocation_base(), which is nulled out
-      // by Detach. This means there is a dangling pointer until we detach the
-      // buffer. Since there is no way for the user to directly call
-      // FreeBackingStore, we can ensure this is safe.
-      buffer->FreeBackingStoreFromMainThread();
-    }
-  }
-
-  DCHECK(buffer->is_external());
-  buffer->set_is_wasm_memory(false);
-  buffer->set_is_detachable(true);
-  buffer->Detach();
-}
-
-}  // namespace wasm
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/src/wasm/wasm-module-builder.cc b/deps/v8/src/wasm/wasm-module-builder.cc
index c8a65ba6a2..c11a69ad46 100644
--- a/deps/v8/src/wasm/wasm-module-builder.cc
+++ b/deps/v8/src/wasm/wasm-module-builder.cc
@@ -343,8 +343,7 @@ uint32_t WasmModuleBuilder::AddImport(Vector<const char> name,
 
 uint32_t WasmModuleBuilder::AddGlobalImport(Vector<const char> name,
                                             ValueType type, bool mutability) {
-  global_imports_.push_back(
-      {name, ValueTypes::ValueTypeCodeFor(type), mutability});
+  global_imports_.push_back({name, type.value_type_code(), mutability});
   return static_cast<uint32_t>(global_imports_.size() - 1);
 }
 
@@ -408,11 +407,11 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
       buffer->write_u8(kWasmFunctionTypeCode);
       buffer->write_size(sig->parameter_count());
       for (auto param : sig->parameters()) {
-        buffer->write_u8(ValueTypes::ValueTypeCodeFor(param));
+        buffer->write_u8(param.value_type_code());
       }
       buffer->write_size(sig->return_count());
       for (auto ret : sig->returns()) {
-        buffer->write_u8(ValueTypes::ValueTypeCodeFor(ret));
+        buffer->write_u8(ret.value_type_code());
       }
     }
     FixupSection(buffer, start);
@@ -455,7 +454,7 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
     size_t start = EmitSection(kTableSectionCode, buffer);
     buffer->write_size(tables_.size());
     for (const WasmTable& table : tables_) {
-      buffer->write_u8(ValueTypes::ValueTypeCodeFor(table.type));
+      buffer->write_u8(table.type.value_type_code());
       buffer->write_u8(table.has_maximum ? kHasMaximumFlag : kNoMaximumFlag);
       buffer->write_size(table.min_size);
       if (table.has_maximum) buffer->write_size(table.max_size);
@@ -486,8 +485,8 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
     size_t start = EmitSection(kGlobalSectionCode, buffer);
     buffer->write_size(globals_.size());
 
-    for (auto global : globals_) {
-      buffer->write_u8(ValueTypes::ValueTypeCodeFor(global.type));
+    for (const WasmGlobal& global : globals_) {
+      buffer->write_u8(global.type.value_type_code());
       buffer->write_u8(global.mutability ? 1 : 0);
       switch (global.init.kind) {
         case WasmInitExpr::kI32Const:
@@ -522,22 +521,22 @@ void WasmModuleBuilder::WriteTo(ZoneBuffer* buffer) const {
           break;
         case WasmInitExpr::kNone: {
           // No initializer, emit a default value.
-          switch (global.type) {
-            case kWasmI32:
+          switch (global.type.kind()) {
+            case ValueType::kI32:
               buffer->write_u8(kExprI32Const);
               // LEB encoding of 0.
               buffer->write_u8(0);
               break;
-            case kWasmI64:
+            case ValueType::kI64:
               buffer->write_u8(kExprI64Const);
               // LEB encoding of 0.
               buffer->write_u8(0);
               break;
-            case kWasmF32:
+            case ValueType::kF32:
               buffer->write_u8(kExprF32Const);
               buffer->write_f32(0.f);
               break;
-            case kWasmF64:
+            case ValueType::kF64:
               buffer->write_u8(kExprF64Const);
               buffer->write_f64(0.);
               break;
diff --git a/deps/v8/src/wasm/wasm-module-sourcemap.cc b/deps/v8/src/wasm/wasm-module-sourcemap.cc
index cfe54e7c37..85a171e5ac 100644
--- a/deps/v8/src/wasm/wasm-module-sourcemap.cc
+++ b/deps/v8/src/wasm/wasm-module-sourcemap.cc
@@ -27,8 +27,7 @@ WasmModuleSourceMap::WasmModuleSourceMap(v8::Isolate* v8_isolate,
   v8::Local<v8::Value> version_value, sources_value, mappings_value;
   bool has_valid_version =
       src_map_obj
-          ->Get(context,
-                v8::String::NewFromUtf8(v8_isolate, "version").ToLocalChecked())
+          ->Get(context, v8::String::NewFromUtf8Literal(v8_isolate, "version"))
           .ToLocal(&version_value) &&
       version_value->IsUint32();
   uint32_t version = 0;
@@ -38,8 +37,7 @@ WasmModuleSourceMap::WasmModuleSourceMap(v8::Isolate* v8_isolate,
 
   bool has_valid_sources =
       src_map_obj
-          ->Get(context,
-                v8::String::NewFromUtf8(v8_isolate, "sources").ToLocalChecked())
+          ->Get(context, v8::String::NewFromUtf8Literal(v8_isolate, "sources"))
           .ToLocal(&sources_value) &&
       sources_value->IsArray();
   if (!has_valid_sources) return;
@@ -48,8 +46,7 @@ WasmModuleSourceMap::WasmModuleSourceMap(v8::Isolate* v8_isolate,
       v8::Local<v8::Object>::Cast(sources_value);
   v8::Local<v8::Value> sources_len_value;
   if (!sources_arr
-           ->Get(context,
-                 v8::String::NewFromUtf8(v8_isolate, "length").ToLocalChecked())
+           ->Get(context, v8::String::NewFromUtf8Literal(v8_isolate, "length"))
            .ToLocal(&sources_len_value))
     return;
   uint32_t sources_len = 0;
@@ -71,9 +68,7 @@ WasmModuleSourceMap::WasmModuleSourceMap(v8::Isolate* v8_isolate,
 
   bool has_valid_mappings =
       src_map_obj
-          ->Get(
-              context,
-              v8::String::NewFromUtf8(v8_isolate, "mappings").ToLocalChecked())
+          ->Get(context, v8::String::NewFromUtf8Literal(v8_isolate, "mappings"))
           .ToLocal(&mappings_value) &&
       mappings_value->IsString();
   if (!has_valid_mappings) return;
diff --git a/deps/v8/src/wasm/wasm-module-sourcemap.h b/deps/v8/src/wasm/wasm-module-sourcemap.h
index 83293ae205..7d3116f3b3 100644
--- a/deps/v8/src/wasm/wasm-module-sourcemap.h
+++ b/deps/v8/src/wasm/wasm-module-sourcemap.h
@@ -18,7 +18,7 @@ namespace wasm {
 // toolchain (e.g. Emscripten). This implementation mostly complies with the
 // specification (https://sourcemaps.info/spec.html), with the following
 // accommodations:
-// 1. "names" field is an empty array in current source maps of WASM, hence it
+// 1. "names" field is an empty array in current source maps of Wasm, hence it
 // is not handled;
 // 2. The semicolons divides "mappings" field into groups, each of which
 // represents a line in the generated code. As *.wasm is in binary format, there
@@ -37,13 +37,13 @@ class V8_EXPORT_PRIVATE WasmModuleSourceMap {
   // and can be correctly decoded.
   bool IsValid() const { return valid_; }
 
-  // Given a function located at [start, end) in WASM Module, this function
+  // Given a function located at [start, end) in Wasm Module, this function
   // checks if this function has its corresponding source code.
   bool HasSource(size_t start, size_t end) const;
 
   // Given a function's base address start and an address addr within, this
   // function checks if the address can be mapped to an offset in this function.
-  // For example, we have the following memory layout for WASM functions, foo
+  // For example, we have the following memory layout for Wasm functions, foo
   // and bar, and O1, O2, O3 and O4 are the decoded offsets of source map:
   //
   // O1 --- O2 ----- O3 ----- O4
diff --git a/deps/v8/src/wasm/wasm-module.cc b/deps/v8/src/wasm/wasm-module.cc
index d75198d770..4a785c820d 100644
--- a/deps/v8/src/wasm/wasm-module.cc
+++ b/deps/v8/src/wasm/wasm-module.cc
@@ -30,19 +30,35 @@ namespace wasm {
 // static
 const uint32_t WasmElemSegment::kNullIndex;
 
-WireBytesRef DecodedFunctionNames::Lookup(const ModuleWireBytes& wire_bytes,
-                                          uint32_t function_index) const {
+WireBytesRef DecodedFunctionNames::Lookup(
+    const ModuleWireBytes& wire_bytes, uint32_t function_index,
+    Vector<const WasmExport> export_table) const {
   base::MutexGuard lock(&mutex_);
   if (!function_names_) {
     function_names_.reset(new std::unordered_map<uint32_t, WireBytesRef>());
     DecodeFunctionNames(wire_bytes.start(), wire_bytes.end(),
-                        function_names_.get());
+                        function_names_.get(), export_table);
   }
   auto it = function_names_->find(function_index);
   if (it == function_names_->end()) return WireBytesRef();
   return it->second;
 }
 
+std::pair<WireBytesRef, WireBytesRef> DecodedGlobalNames::Lookup(
+    uint32_t global_index, Vector<const WasmImport> import_table,
+    Vector<const WasmExport> export_table) const {
+  base::MutexGuard lock(&mutex_);
+  if (!global_names_) {
+    global_names_.reset(
+        new std::unordered_map<uint32_t,
+                               std::pair<WireBytesRef, WireBytesRef>>());
+    DecodeGlobalNames(import_table, export_table, global_names_.get());
+  }
+  auto it = global_names_->find(global_index);
+  if (it == global_names_->end()) return {};
+  return it->second;
+}
+
 // static
 int MaxNumExportWrappers(const WasmModule* module) {
   // For each signature there may exist a wrapper, both for imported and
@@ -113,7 +129,7 @@ void DecodedFunctionNames::AddForTesting(int function_index,
 
 AsmJsOffsetInformation::AsmJsOffsetInformation(
     Vector<const byte> encoded_offsets)
-    : encoded_offsets_(OwnedVector<uint8_t>::Of(encoded_offsets)) {}
+    : encoded_offsets_(OwnedVector<const uint8_t>::Of(encoded_offsets)) {}
 
 AsmJsOffsetInformation::~AsmJsOffsetInformation() = default;
 
@@ -176,8 +192,8 @@ WasmName ModuleWireBytes::GetNameOrNull(WireBytesRef ref) const {
 // Get a string stored in the module bytes representing a function name.
 WasmName ModuleWireBytes::GetNameOrNull(const WasmFunction* function,
                                         const WasmModule* module) const {
-  return GetNameOrNull(
-      module->function_names.Lookup(*this, function->func_index));
+  return GetNameOrNull(module->function_names.Lookup(
+      *this, function->func_index, VectorOf(module->export_table)));
 }
 
 std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name) {
@@ -218,38 +234,41 @@ namespace {
 // Converts the given {type} into a string representation that can be used in
 // reflective functions. Should be kept in sync with the {GetValueType} helper.
 Handle<String> ToValueTypeString(Isolate* isolate, ValueType type) {
+  // TODO(ahaas/jkummerow): This could be as simple as:
+  // return isolate->factory()->InternalizeUtf8String(type.type_name());
+  // if we clean up all occurrences of "anyfunc" in favor of "funcref".
   Factory* factory = isolate->factory();
   Handle<String> string;
-  switch (type) {
-    case i::wasm::kWasmI32: {
+  switch (type.kind()) {
+    case i::wasm::ValueType::kI32: {
       string = factory->InternalizeUtf8String("i32");
       break;
     }
-    case i::wasm::kWasmI64: {
+    case i::wasm::ValueType::kI64: {
       string = factory->InternalizeUtf8String("i64");
       break;
     }
-    case i::wasm::kWasmF32: {
+    case i::wasm::ValueType::kF32: {
       string = factory->InternalizeUtf8String("f32");
       break;
     }
-    case i::wasm::kWasmF64: {
+    case i::wasm::ValueType::kF64: {
       string = factory->InternalizeUtf8String("f64");
       break;
     }
-    case i::wasm::kWasmAnyRef: {
+    case i::wasm::ValueType::kAnyRef: {
       string = factory->InternalizeUtf8String("anyref");
       break;
     }
-    case i::wasm::kWasmFuncRef: {
+    case i::wasm::ValueType::kFuncRef: {
       string = factory->InternalizeUtf8String("anyfunc");
       break;
     }
-    case i::wasm::kWasmNullRef: {
+    case i::wasm::ValueType::kNullRef: {
       string = factory->InternalizeUtf8String("nullref");
       break;
     }
-    case i::wasm::kWasmExnRef: {
+    case i::wasm::ValueType::kExnRef: {
       string = factory->InternalizeUtf8String("exnref");
       break;
     }
@@ -261,7 +280,7 @@ Handle<String> ToValueTypeString(Isolate* isolate, ValueType type) {
 
 }  // namespace
 
-Handle<JSObject> GetTypeForFunction(Isolate* isolate, FunctionSig* sig) {
+Handle<JSObject> GetTypeForFunction(Isolate* isolate, const FunctionSig* sig) {
   Factory* factory = isolate->factory();
 
   // Extract values for the {ValueType[]} arrays.
@@ -333,13 +352,12 @@ Handle<JSObject> GetTypeForTable(Isolate* isolate, ValueType type,
   Factory* factory = isolate->factory();
 
   Handle<String> element;
-  if (type == ValueType::kWasmFuncRef) {
+  if (type == kWasmFuncRef) {
     // TODO(wasm): We should define the "anyfunc" string in one central place
     // and then use that constant everywhere.
     element = factory->InternalizeUtf8String("anyfunc");
   } else {
-    DCHECK(WasmFeatures::FromFlags().has_anyref() &&
-           type == ValueType::kWasmAnyRef);
+    DCHECK(WasmFeatures::FromFlags().has_anyref() && type == kWasmAnyRef);
     element = factory->InternalizeUtf8String("anyref");
   }
 
@@ -641,7 +659,7 @@ size_t EstimateStoredSize(const WasmModule* module) {
          VectorSize(module->elem_segments);
 }
 
-size_t PrintSignature(Vector<char> buffer, wasm::FunctionSig* sig) {
+size_t PrintSignature(Vector<char> buffer, const wasm::FunctionSig* sig) {
   if (buffer.empty()) return 0;
   size_t old_size = buffer.size();
   auto append_char = [&buffer](char c) {
@@ -650,11 +668,11 @@ size_t PrintSignature(Vector<char> buffer, wasm::FunctionSig* sig) {
     buffer += 1;
   };
   for (wasm::ValueType t : sig->parameters()) {
-    append_char(wasm::ValueTypes::ShortNameOf(t));
+    append_char(t.short_name());
   }
   append_char(':');
   for (wasm::ValueType t : sig->returns()) {
-    append_char(wasm::ValueTypes::ShortNameOf(t));
+    append_char(t.short_name());
   }
   buffer[0] = '\0';
   return old_size - buffer.size();
diff --git a/deps/v8/src/wasm/wasm-module.h b/deps/v8/src/wasm/wasm-module.h
index 9fb67a7c16..6c782607bb 100644
--- a/deps/v8/src/wasm/wasm-module.h
+++ b/deps/v8/src/wasm/wasm-module.h
@@ -51,12 +51,13 @@ class WireBytesRef {
 
 // Static representation of a wasm function.
 struct WasmFunction {
-  FunctionSig* sig;      // signature of the function.
-  uint32_t func_index;   // index into the function table.
-  uint32_t sig_index;    // index into the signature table.
-  WireBytesRef code;     // code of this function.
+  const FunctionSig* sig;  // signature of the function.
+  uint32_t func_index;     // index into the function table.
+  uint32_t sig_index;      // index into the signature table.
+  WireBytesRef code;       // code of this function.
   bool imported;
   bool exported;
+  bool declared;
 };
 
 // Static representation of a wasm global variable.
@@ -79,7 +80,7 @@ using WasmExceptionSig = FunctionSig;
 // Static representation of a wasm exception type.
 struct WasmException {
   explicit WasmException(const WasmExceptionSig* sig) : sig(sig) {}
-  FunctionSig* ToFunctionSig() const { return const_cast<FunctionSig*>(sig); }
+  const FunctionSig* ToFunctionSig() const { return sig; }
 
   const WasmExceptionSig* sig;  // type signature of the exception.
 };
@@ -115,19 +116,31 @@ struct WasmElemSegment {
 
   // Construct an active segment.
   WasmElemSegment(uint32_t table_index, WasmInitExpr offset)
-      : table_index(table_index), offset(offset), active(true) {}
-
-  // Construct a passive segment, which has no table index or offset.
-  WasmElemSegment() : table_index(0), active(false) {}
+      : type(kWasmFuncRef),
+        table_index(table_index),
+        offset(offset),
+        status(kStatusActive) {}
+
+  // Construct a passive or declarative segment, which has no table index or
+  // offset.
+  explicit WasmElemSegment(bool declarative)
+      : type(kWasmFuncRef),
+        table_index(0),
+        status(declarative ? kStatusDeclarative : kStatusPassive) {}
 
   // Used in the {entries} vector to represent a `ref.null` entry in a passive
   // segment.
   V8_EXPORT_PRIVATE static const uint32_t kNullIndex = ~0u;
 
+  ValueType type;
   uint32_t table_index;
   WasmInitExpr offset;
   std::vector<uint32_t> entries;
-  bool active;  // true if copied automatically during instantiation.
+  enum Status {
+    kStatusActive,      // copied automatically during instantiation.
+    kStatusPassive,     // copied explicitly after instantiation.
+    kStatusDeclarative  // purely declarative and never copied.
+  } status;
 };
 
 // Static representation of a wasm import.
@@ -181,7 +194,8 @@ struct ModuleWireBytes;
 class V8_EXPORT_PRIVATE DecodedFunctionNames {
  public:
   WireBytesRef Lookup(const ModuleWireBytes& wire_bytes,
-                      uint32_t function_index) const;
+                      uint32_t function_index,
+                      Vector<const WasmExport> export_table) const;
   void AddForTesting(int function_index, WireBytesRef name);
 
  private:
@@ -192,6 +206,21 @@ class V8_EXPORT_PRIVATE DecodedFunctionNames {
       function_names_;
 };
 
+class V8_EXPORT_PRIVATE DecodedGlobalNames {
+ public:
+  std::pair<WireBytesRef, WireBytesRef> Lookup(
+      uint32_t global_index, Vector<const WasmImport> import_table,
+      Vector<const WasmExport> export_table) const;
+
+ private:
+  // {global_names_} is populated lazily after decoding, and therefore needs a
+  // mutex to protect concurrent modifications from multiple {WasmModuleObject}.
+  mutable base::Mutex mutex_;
+  mutable std::unique_ptr<
+      std::unordered_map<uint32_t, std::pair<WireBytesRef, WireBytesRef>>>
+      global_names_;
+};
+
 class V8_EXPORT_PRIVATE AsmJsOffsetInformation {
  public:
   explicit AsmJsOffsetInformation(Vector<const byte> encoded_offsets);
@@ -242,8 +271,9 @@ struct V8_EXPORT_PRIVATE WasmModule {
   uint32_t num_declared_functions = 0;  // excluding imported
   uint32_t num_exported_functions = 0;
   uint32_t num_declared_data_segments = 0;  // From the DataCount section.
+  WireBytesRef code = {0, 0};
   WireBytesRef name = {0, 0};
-  std::vector<FunctionSig*> signatures;  // by signature index
+  std::vector<const FunctionSig*> signatures;  // by signature index
   std::vector<uint32_t> signature_ids;   // by signature index
   std::vector<WasmFunction> functions;
   std::vector<WasmDataSegment> data_segments;
@@ -257,6 +287,7 @@ struct V8_EXPORT_PRIVATE WasmModule {
 
   ModuleOrigin origin = kWasmOrigin;  // origin of the module
   DecodedFunctionNames function_names;
+  DecodedGlobalNames global_names;
   std::string source_map_url;
 
   // Asm.js source position information. Only available for modules compiled
@@ -350,7 +381,7 @@ std::ostream& operator<<(std::ostream& os, const WasmFunctionName& name);
 V8_EXPORT_PRIVATE bool IsWasmCodegenAllowed(Isolate* isolate,
                                             Handle<Context> context);
 
-Handle<JSObject> GetTypeForFunction(Isolate* isolate, FunctionSig* sig);
+Handle<JSObject> GetTypeForFunction(Isolate* isolate, const FunctionSig* sig);
 Handle<JSObject> GetTypeForGlobal(Isolate* isolate, bool is_mutable,
                                   ValueType type);
 Handle<JSObject> GetTypeForMemory(Isolate* isolate, uint32_t min_size,
@@ -417,7 +448,7 @@ class TruncatedUserString {
 // Print the signature into the given {buffer}. If {buffer} is non-empty, it
 // will be null-terminated, even if the signature is cut off. Returns the number
 // of characters written, excluding the terminating null-byte.
-size_t PrintSignature(Vector<char> buffer, wasm::FunctionSig*);
+size_t PrintSignature(Vector<char> buffer, const wasm::FunctionSig*);
 
 }  // namespace wasm
 }  // namespace internal
diff --git a/deps/v8/src/wasm/wasm-objects-inl.h b/deps/v8/src/wasm/wasm-objects-inl.h
index 211a27a749..2e75981ff1 100644
--- a/deps/v8/src/wasm/wasm-objects-inl.h
+++ b/deps/v8/src/wasm/wasm-objects-inl.h
@@ -123,13 +123,16 @@ ACCESSORS(WasmGlobalObject, untagged_buffer, JSArrayBuffer,
 ACCESSORS(WasmGlobalObject, tagged_buffer, FixedArray, kTaggedBufferOffset)
 SMI_ACCESSORS(WasmGlobalObject, offset, kOffsetOffset)
 SMI_ACCESSORS(WasmGlobalObject, flags, kFlagsOffset)
-BIT_FIELD_ACCESSORS(WasmGlobalObject, flags, type, WasmGlobalObject::TypeBits)
+wasm::ValueType WasmGlobalObject::type() const {
+  return wasm::ValueType(TypeBits::decode(flags()));
+}
+void WasmGlobalObject::set_type(wasm::ValueType value) {
+  set_flags(TypeBits::update(flags(), value.kind()));
+}
 BIT_FIELD_ACCESSORS(WasmGlobalObject, flags, is_mutable,
                     WasmGlobalObject::IsMutableBit)
 
-int WasmGlobalObject::type_size() const {
-  return wasm::ValueTypes::ElementSizeInBytes(type());
-}
+int WasmGlobalObject::type_size() const { return type().element_size_bytes(); }
 
 Address WasmGlobalObject::address() const {
   DCHECK_NE(type(), wasm::kWasmAnyRef);
@@ -155,7 +158,7 @@ double WasmGlobalObject::GetF64() {
 
 Handle<Object> WasmGlobalObject::GetRef() {
   // We use this getter for anyref, funcref, and exnref.
-  DCHECK(wasm::ValueTypes::IsReferenceType(type()));
+  DCHECK(type().IsReferenceType());
   return handle(tagged_buffer().get(offset()), GetIsolate());
 }
 
@@ -231,6 +234,8 @@ PRIMITIVE_ACCESSORS(WasmInstanceObject, data_segment_sizes, uint32_t*,
                     kDataSegmentSizesOffset)
 PRIMITIVE_ACCESSORS(WasmInstanceObject, dropped_elem_segments, byte*,
                     kDroppedElemSegmentsOffset)
+PRIMITIVE_ACCESSORS(WasmInstanceObject, hook_on_function_call_address, Address,
+                    kHookOnFunctionCallAddressOffset)
 
 ACCESSORS(WasmInstanceObject, module_object, WasmModuleObject,
           kModuleObjectOffset)
@@ -396,14 +401,11 @@ OPTIONAL_ACCESSORS(WasmDebugInfo, c_wasm_entry_map, Managed<wasm::SignatureMap>,
 #undef PRIMITIVE_ACCESSORS
 
 wasm::ValueType WasmTableObject::type() {
-  return static_cast<wasm::ValueType>(raw_type());
+  return wasm::ValueType(static_cast<wasm::ValueType::Kind>(raw_type()));
 }
 
 bool WasmMemoryObject::has_maximum_pages() { return maximum_pages() >= 0; }
 
-// WasmExceptionTag
-TQ_SMI_ACCESSORS(WasmExceptionTag, index)
-
 // AsmWasmData
 ACCESSORS(AsmWasmData, managed_native_module, Managed<wasm::NativeModule>,
           kManagedNativeModuleOffset)
diff --git a/deps/v8/src/wasm/wasm-objects.cc b/deps/v8/src/wasm/wasm-objects.cc
index 15fa129d2b..41b9d50312 100644
--- a/deps/v8/src/wasm/wasm-objects.cc
+++ b/deps/v8/src/wasm/wasm-objects.cc
@@ -243,7 +243,7 @@ MaybeHandle<String> WasmModuleObject::GetFunctionNameOrNull(
   DCHECK_LT(func_index, module_object->module()->functions.size());
   wasm::WireBytesRef name = module_object->module()->function_names.Lookup(
       wasm::ModuleWireBytes(module_object->native_module()->wire_bytes()),
-      func_index);
+      func_index, VectorOf(module_object->module()->export_table));
   if (!name.is_set()) return {};
   return ExtractUtf8StringFromModuleBytes(isolate, module_object, name,
                                           kNoInternalize);
@@ -256,7 +256,8 @@ Handle<String> WasmModuleObject::GetFunctionName(
       GetFunctionNameOrNull(isolate, module_object, func_index);
   if (!name.is_null()) return name.ToHandleChecked();
   EmbeddedVector<char, 32> buffer;
-  int length = SNPrintF(buffer, "wasm-function[%u]", func_index);
+  DCHECK_GE(func_index, module_object->module()->num_imported_functions);
+  int length = SNPrintF(buffer, "func%u", func_index);
   return isolate->factory()
       ->NewStringFromOneByte(Vector<uint8_t>::cast(buffer.SubVector(0, length)))
       .ToHandleChecked();
@@ -266,8 +267,8 @@ Vector<const uint8_t> WasmModuleObject::GetRawFunctionName(
     uint32_t func_index) {
   DCHECK_GT(module()->functions.size(), func_index);
   wasm::ModuleWireBytes wire_bytes(native_module()->wire_bytes());
-  wasm::WireBytesRef name_ref =
-      module()->function_names.Lookup(wire_bytes, func_index);
+  wasm::WireBytesRef name_ref = module()->function_names.Lookup(
+      wire_bytes, func_index, VectorOf(module()->export_table));
   wasm::WasmName name = wire_bytes.GetNameOrNull(name_ref);
   return Vector<const uint8_t>::cast(name);
 }
@@ -299,7 +300,7 @@ Handle<WasmTableObject> WasmTableObject::New(Isolate* isolate,
   table_obj->set_entries(*backing_store);
   table_obj->set_current_length(initial);
   table_obj->set_maximum_length(*max);
-  table_obj->set_raw_type(static_cast<int>(type));
+  table_obj->set_raw_type(static_cast<int>(type.kind()));
 
   table_obj->set_dispatch_tables(ReadOnlyRoots(isolate).empty_fixed_array());
   if (entries != nullptr) {
@@ -516,7 +517,7 @@ void WasmTableObject::Fill(Isolate* isolate, Handle<WasmTableObject> table,
 
 void WasmTableObject::UpdateDispatchTables(
     Isolate* isolate, Handle<WasmTableObject> table, int entry_index,
-    wasm::FunctionSig* sig, Handle<WasmInstanceObject> target_instance,
+    const wasm::FunctionSig* sig, Handle<WasmInstanceObject> target_instance,
     int target_func_index) {
   // We simply need to update the IFTs for each instance that imports
   // this table.
@@ -879,26 +880,22 @@ int32_t WasmMemoryObject::Grow(Isolate* isolate,
   if (old_buffer->is_asmjs_memory()) return -1;
 
   // Checks for maximum memory size.
-  uint32_t maximum_pages = wasm::max_mem_pages();
+  uint32_t maximum_pages = wasm::max_maximum_mem_pages();
   if (memory_object->has_maximum_pages()) {
     maximum_pages = std::min(
         maximum_pages, static_cast<uint32_t>(memory_object->maximum_pages()));
   }
-  CHECK_GE(wasm::max_mem_pages(), maximum_pages);
+  DCHECK_GE(wasm::max_maximum_mem_pages(), maximum_pages);
   size_t old_size = old_buffer->byte_length();
-  CHECK_EQ(0, old_size % wasm::kWasmPageSize);
+  DCHECK_EQ(0, old_size % wasm::kWasmPageSize);
   size_t old_pages = old_size / wasm::kWasmPageSize;
-  CHECK_GE(wasm::max_mem_pages(), old_pages);
-  if ((pages > maximum_pages - old_pages) ||          // exceeds remaining
-      (pages > wasm::max_mem_pages() - old_pages)) {  // exceeds limit
-    return -1;
-  }
+  CHECK_GE(wasm::max_maximum_mem_pages(), old_pages);
+  if (pages > maximum_pages - old_pages) return -1;
   std::shared_ptr<BackingStore> backing_store = old_buffer->GetBackingStore();
   if (!backing_store) return -1;
 
   // Compute new size.
   size_t new_pages = old_pages + pages;
-  size_t new_byte_length = new_pages * wasm::kWasmPageSize;
 
   // Try to handle shared memory first.
   if (old_buffer->is_shared()) {
@@ -909,6 +906,8 @@ int32_t WasmMemoryObject::Grow(Isolate* isolate,
                                                     new_pages);
         // Broadcasting the update should update this memory object too.
         CHECK_NE(*old_buffer, memory_object->array_buffer());
+        // If the allocation succeeded, then this can't possibly overflow:
+        size_t new_byte_length = new_pages * wasm::kWasmPageSize;
         // This is a less than check, as it is not guaranteed that the SAB
         // length here will be equal to the stashed length above as calls to
         // grow the same memory object can come in from different workers.
@@ -933,7 +932,13 @@ int32_t WasmMemoryObject::Grow(Isolate* isolate,
   // Try allocating a new backing store and copying.
   std::unique_ptr<BackingStore> new_backing_store =
       backing_store->CopyWasmMemory(isolate, new_pages);
-  if (!new_backing_store) return -1;
+  if (!new_backing_store) {
+    // Crash on out-of-memory if the correctness fuzzer is running.
+    if (FLAG_correctness_fuzzer_suppressions) {
+      FATAL("could not grow wasm memory");
+    }
+    return -1;
+  }
 
   // Detach old and create a new one with the new backing store.
   old_buffer->Detach(true);
@@ -962,7 +967,7 @@ MaybeHandle<WasmGlobalObject> WasmGlobalObject::New(
     global_obj->set_is_mutable(is_mutable);
   }
 
-  if (wasm::ValueTypes::IsReferenceType(type)) {
+  if (type.IsReferenceType()) {
     DCHECK(maybe_untagged_buffer.is_null());
     Handle<FixedArray> tagged_buffer;
     if (!maybe_tagged_buffer.ToHandle(&tagged_buffer)) {
@@ -974,7 +979,7 @@ MaybeHandle<WasmGlobalObject> WasmGlobalObject::New(
     global_obj->set_tagged_buffer(*tagged_buffer);
   } else {
     DCHECK(maybe_tagged_buffer.is_null());
-    uint32_t type_size = wasm::ValueTypes::ElementSizeInBytes(type);
+    uint32_t type_size = type.element_size_bytes();
 
     Handle<JSArrayBuffer> untagged_buffer;
     if (!maybe_untagged_buffer.ToHandle(&untagged_buffer)) {
@@ -1086,7 +1091,7 @@ void ImportedFunctionEntry::SetWasmToJs(
 
 void ImportedFunctionEntry::SetWasmToWasm(WasmInstanceObject instance,
                                           Address call_target) {
-  TRACE_IFT("Import WASM 0x%" PRIxPTR "[%d] = {instance=0x%" PRIxPTR
+  TRACE_IFT("Import Wasm 0x%" PRIxPTR "[%d] = {instance=0x%" PRIxPTR
             ", target=0x%" PRIxPTR "}\n",
             instance_->ptr(), index_, instance.ptr(), call_target);
   instance_->imported_function_refs().set(index_, instance);
@@ -1233,6 +1238,8 @@ Handle<WasmInstanceObject> WasmInstanceObject::New(
   instance->set_module_object(*module_object);
   instance->set_jump_table_start(
       module_object->native_module()->jump_table_start());
+  instance->set_hook_on_function_call_address(
+      isolate->debug()->hook_on_function_call_address());
 
   // Insert the new instance into the scripts weak list of instances. This list
   // is used for breakpoints affecting all instances belonging to the script.
@@ -1286,7 +1293,11 @@ void WasmInstanceObject::InitElemSegmentArrays(
   auto module = module_object->module();
   auto num_elem_segments = module->elem_segments.size();
   for (size_t i = 0; i < num_elem_segments; ++i) {
-    instance->dropped_elem_segments()[i] = 0;
+    instance->dropped_elem_segments()[i] =
+        module->elem_segments[i].status ==
+                wasm::WasmElemSegment::kStatusDeclarative
+            ? 1
+            : 0;
   }
 }
 
@@ -1437,7 +1448,7 @@ void WasmInstanceObject::ImportWasmJSFunctionIntoTable(
   // Note that {SignatureMap::Find} may return {-1} if the signature is
   // not found; it will simply never match any check.
   Zone zone(isolate->allocator(), ZONE_NAME);
-  wasm::FunctionSig* sig = js_function->GetSignature(&zone);
+  const wasm::FunctionSig* sig = js_function->GetSignature(&zone);
   auto sig_id = instance->module()->signature_map.Find(*sig);
 
   // Compile a wrapper for the target callable.
@@ -1458,8 +1469,9 @@ void WasmInstanceObject::ImportWasmJSFunctionIntoTable(
         isolate->wasm_engine(), &env, kind, sig, false);
     std::unique_ptr<wasm::WasmCode> wasm_code = native_module->AddCode(
         result.func_index, result.code_desc, result.frame_slot_count,
-        result.tagged_parameter_slots, std::move(result.protected_instructions),
-        std::move(result.source_positions), GetCodeKind(result),
+        result.tagged_parameter_slots,
+        result.protected_instructions_data.as_vector(),
+        result.source_positions.as_vector(), GetCodeKind(result),
         wasm::ExecutionTier::kNone);
     wasm::WasmCode* published_code =
         native_module->PublishCode(std::move(wasm_code));
@@ -1480,7 +1492,7 @@ void WasmInstanceObject::ImportWasmJSFunctionIntoTable(
 // static
 uint8_t* WasmInstanceObject::GetGlobalStorage(
     Handle<WasmInstanceObject> instance, const wasm::WasmGlobal& global) {
-  DCHECK(!wasm::ValueTypes::IsReferenceType(global.type));
+  DCHECK(!global.type.IsReferenceType());
   if (global.mutability && global.imported) {
     return reinterpret_cast<byte*>(
         instance->imported_mutable_globals()[global.index]);
@@ -1493,7 +1505,7 @@ uint8_t* WasmInstanceObject::GetGlobalStorage(
 std::pair<Handle<FixedArray>, uint32_t>
 WasmInstanceObject::GetGlobalBufferAndIndex(Handle<WasmInstanceObject> instance,
                                             const wasm::WasmGlobal& global) {
-  DCHECK(wasm::ValueTypes::IsReferenceType(global.type));
+  DCHECK(global.type.IsReferenceType());
   Isolate* isolate = instance->GetIsolate();
   if (global.mutability && global.imported) {
     Handle<FixedArray> buffer(
@@ -1508,10 +1520,37 @@ WasmInstanceObject::GetGlobalBufferAndIndex(Handle<WasmInstanceObject> instance,
 }
 
 // static
+MaybeHandle<String> WasmInstanceObject::GetGlobalNameOrNull(
+    Isolate* isolate, Handle<WasmInstanceObject> instance,
+    uint32_t global_index) {
+  wasm::ModuleWireBytes wire_bytes(
+      instance->module_object().native_module()->wire_bytes());
+
+  // This is pair of <module_name, field_name>.
+  // If field_name is not set then we don't generate a name. Else if module_name
+  // is set then it is imported global. Otherwise it is exported global.
+  std::pair<wasm::WireBytesRef, wasm::WireBytesRef> name_ref =
+      instance->module()->global_names.Lookup(
+          global_index, VectorOf(instance->module()->import_table),
+          VectorOf(instance->module()->export_table));
+  if (!name_ref.second.is_set()) return {};
+  Vector<const char> field_name = wire_bytes.GetNameOrNull(name_ref.second);
+  if (!name_ref.first.is_set()) {
+    return isolate->factory()->NewStringFromUtf8(VectorOf(field_name));
+  }
+  Vector<const char> module_name = wire_bytes.GetNameOrNull(name_ref.first);
+  std::string global_name;
+  global_name.append(module_name.begin(), module_name.end());
+  global_name.append(".");
+  global_name.append(field_name.begin(), field_name.end());
+  return isolate->factory()->NewStringFromUtf8(VectorOf(global_name));
+}
+
+// static
 wasm::WasmValue WasmInstanceObject::GetGlobalValue(
     Handle<WasmInstanceObject> instance, const wasm::WasmGlobal& global) {
   Isolate* isolate = instance->GetIsolate();
-  if (wasm::ValueTypes::IsReferenceType(global.type)) {
+  if (global.type.IsReferenceType()) {
     Handle<FixedArray> global_buffer;  // The buffer of the global.
     uint32_t global_index = 0;         // The index into the buffer.
     std::tie(global_buffer, global_index) =
@@ -1520,9 +1559,9 @@ wasm::WasmValue WasmInstanceObject::GetGlobalValue(
   }
   Address ptr = reinterpret_cast<Address>(GetGlobalStorage(instance, global));
   using wasm::Simd128;
-  switch (global.type) {
+  switch (global.type.kind()) {
 #define CASE_TYPE(valuetype, ctype) \
-  case wasm::valuetype:             \
+  case wasm::ValueType::valuetype:  \
     return wasm::WasmValue(base::ReadLittleEndianValue<ctype>(ptr));
     FOREACH_WASMVALUE_CTYPES(CASE_TYPE)
 #undef CASE_TYPE
@@ -1645,8 +1684,7 @@ namespace {
 constexpr uint32_t kBytesPerExceptionValuesArrayElement = 2;
 
 size_t ComputeEncodedElementSize(wasm::ValueType type) {
-  size_t byte_size =
-      static_cast<size_t>(wasm::ValueTypes::ElementSizeInBytes(type));
+  size_t byte_size = type.element_size_bytes();
   DCHECK_EQ(byte_size % kBytesPerExceptionValuesArrayElement, 0);
   DCHECK_LE(1, byte_size / kBytesPerExceptionValuesArrayElement);
   return byte_size / kBytesPerExceptionValuesArrayElement;
@@ -1662,28 +1700,29 @@ uint32_t WasmExceptionPackage::GetEncodedSize(
   const wasm::WasmExceptionSig* sig = exception->sig;
   uint32_t encoded_size = 0;
   for (size_t i = 0; i < sig->parameter_count(); ++i) {
-    switch (sig->GetParam(i)) {
-      case wasm::kWasmI32:
-      case wasm::kWasmF32:
+    switch (sig->GetParam(i).kind()) {
+      case wasm::ValueType::kI32:
+      case wasm::ValueType::kF32:
         DCHECK_EQ(2, ComputeEncodedElementSize(sig->GetParam(i)));
         encoded_size += 2;
         break;
-      case wasm::kWasmI64:
-      case wasm::kWasmF64:
+      case wasm::ValueType::kI64:
+      case wasm::ValueType::kF64:
         DCHECK_EQ(4, ComputeEncodedElementSize(sig->GetParam(i)));
         encoded_size += 4;
         break;
-      case wasm::kWasmS128:
+      case wasm::ValueType::kS128:
         DCHECK_EQ(8, ComputeEncodedElementSize(sig->GetParam(i)));
         encoded_size += 8;
         break;
-      case wasm::kWasmAnyRef:
-      case wasm::kWasmFuncRef:
-      case wasm::kWasmNullRef:
-      case wasm::kWasmExnRef:
+      case wasm::ValueType::kAnyRef:
+      case wasm::ValueType::kFuncRef:
+      case wasm::ValueType::kNullRef:
+      case wasm::ValueType::kExnRef:
         encoded_size += 1;
         break;
-      default:
+      case wasm::ValueType::kStmt:
+      case wasm::ValueType::kBottom:
         UNREACHABLE();
     }
   }
@@ -1808,7 +1847,7 @@ Address WasmExportedFunction::GetWasmCallTarget() {
   return instance().GetCallTarget(function_index());
 }
 
-wasm::FunctionSig* WasmExportedFunction::sig() {
+const wasm::FunctionSig* WasmExportedFunction::sig() {
   return instance().module()->functions[function_index()].sig;
 }
 
@@ -1820,7 +1859,7 @@ bool WasmJSFunction::IsWasmJSFunction(Object object) {
 }
 
 Handle<WasmJSFunction> WasmJSFunction::New(Isolate* isolate,
-                                           wasm::FunctionSig* sig,
+                                           const wasm::FunctionSig* sig,
                                            Handle<JSReceiver> callable) {
   DCHECK_LE(sig->all().size(), kMaxInt);
   int sig_size = static_cast<int>(sig->all().size());
@@ -1846,6 +1885,7 @@ Handle<WasmJSFunction> WasmJSFunction::New(Isolate* isolate,
   Handle<String> name = isolate->factory()->Function_string();
   if (callable->IsJSFunction()) {
     name = JSFunction::GetName(Handle<JSFunction>::cast(callable));
+    name = String::Flatten(isolate, name);
   }
   Handle<Map> function_map = isolate->wasm_exported_function_map();
   NewFunctionArgs args =
@@ -1859,7 +1899,7 @@ JSReceiver WasmJSFunction::GetCallable() const {
   return shared().wasm_js_function_data().callable();
 }
 
-wasm::FunctionSig* WasmJSFunction::GetSignature(Zone* zone) {
+const wasm::FunctionSig* WasmJSFunction::GetSignature(Zone* zone) {
   WasmJSFunctionData function_data = shared().wasm_js_function_data();
   int sig_size = function_data.serialized_signature().length();
   wasm::ValueType* types = zone->NewArray<wasm::ValueType>(sig_size);
@@ -1871,7 +1911,7 @@ wasm::FunctionSig* WasmJSFunction::GetSignature(Zone* zone) {
   return new (zone) wasm::FunctionSig(return_count, parameter_count, types);
 }
 
-bool WasmJSFunction::MatchesSignature(wasm::FunctionSig* sig) {
+bool WasmJSFunction::MatchesSignature(const wasm::FunctionSig* sig) {
   DCHECK_LE(sig->all().size(), kMaxInt);
   int sig_size = static_cast<int>(sig->all().size());
   int return_count = static_cast<int>(sig->return_count());
diff --git a/deps/v8/src/wasm/wasm-objects.h b/deps/v8/src/wasm/wasm-objects.h
index c0a7956e15..972e8d31cd 100644
--- a/deps/v8/src/wasm/wasm-objects.h
+++ b/deps/v8/src/wasm/wasm-objects.h
@@ -93,21 +93,21 @@ class IndirectFunctionTableEntry {
 // The underlying storage in the instance is used by generated code to
 // call imported functions at runtime.
 // Each entry is either:
-//   - WASM to JS, which has fields
+//   - Wasm to JS, which has fields
 //      - object = a Tuple2 of the importing instance and the callable
 //      - target = entrypoint to import wrapper code
-//   - WASM to WASM, which has fields
+//   - Wasm to Wasm, which has fields
 //      - object = target instance
 //      - target = entrypoint for the function
 class ImportedFunctionEntry {
  public:
   inline ImportedFunctionEntry(Handle<WasmInstanceObject>, int index);
 
-  // Initialize this entry as a WASM to JS call. This accepts the isolate as a
+  // Initialize this entry as a Wasm to JS call. This accepts the isolate as a
   // parameter, since it must allocate a tuple.
   V8_EXPORT_PRIVATE void SetWasmToJs(Isolate*, Handle<JSReceiver> callable,
                                      const wasm::WasmCode* wasm_to_js_wrapper);
-  // Initialize this entry as a WASM to WASM call.
+  // Initialize this entry as a Wasm to Wasm call.
   void SetWasmToWasm(WasmInstanceObject target_instance, Address call_target);
 
   WasmInstanceObject instance();
@@ -170,7 +170,7 @@ class WasmModuleObject : public JSObject {
                                                    uint32_t func_index);
 
   // Get the function name of the function identified by the given index.
-  // Returns "wasm-function[func_index]" if the function is unnamed or the
+  // Returns "func[func_index]" if the function is unnamed or the
   // name is not a valid UTF-8 string.
   static Handle<String> GetFunctionName(Isolate*, Handle<WasmModuleObject>,
                                         uint32_t func_index);
@@ -247,7 +247,8 @@ class V8_EXPORT_PRIVATE WasmTableObject : public JSObject {
   // TODO(wasm): Unify these three methods into one.
   static void UpdateDispatchTables(Isolate* isolate,
                                    Handle<WasmTableObject> table,
-                                   int entry_index, wasm::FunctionSig* sig,
+                                   int entry_index,
+                                   const wasm::FunctionSig* sig,
                                    Handle<WasmInstanceObject> target_instance,
                                    int target_func_index);
   static void UpdateDispatchTables(Isolate* isolate,
@@ -333,13 +334,7 @@ class WasmGlobalObject : public JSObject {
   DECL_PRINTER(WasmGlobalObject)
   DECL_VERIFIER(WasmGlobalObject)
 
-#define WASM_GLOBAL_OBJECT_FLAGS_BIT_FIELDS(V, _) \
-  V(TypeBits, wasm::ValueType, 8, _)              \
-  V(IsMutableBit, bool, 1, _)
-
-  DEFINE_BIT_FIELDS(WASM_GLOBAL_OBJECT_FLAGS_BIT_FIELDS)
-
-#undef WASM_GLOBAL_OBJECT_FLAGS_BIT_FIELDS
+  DEFINE_TORQUE_GENERATED_WASM_GLOBAL_OBJECT_FLAGS()
 
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
                                 TORQUE_GENERATED_WASM_GLOBAL_OBJECT_FIELDS)
@@ -410,6 +405,7 @@ class WasmInstanceObject : public JSObject {
   DECL_PRIMITIVE_ACCESSORS(data_segment_starts, Address*)
   DECL_PRIMITIVE_ACCESSORS(data_segment_sizes, uint32_t*)
   DECL_PRIMITIVE_ACCESSORS(dropped_elem_segments, byte*)
+  DECL_PRIMITIVE_ACCESSORS(hook_on_function_call_address, Address)
 
   // Clear uninitialized padding space. This ensures that the snapshot content
   // is deterministic. Depending on the V8 build mode there could be no padding.
@@ -456,6 +452,7 @@ class WasmInstanceObject : public JSObject {
   V(kDataSegmentStartsOffset, kSystemPointerSize)                         \
   V(kDataSegmentSizesOffset, kSystemPointerSize)                          \
   V(kDroppedElemSegmentsOffset, kSystemPointerSize)                       \
+  V(kHookOnFunctionCallAddressOffset, kSystemPointerSize)                 \
   V(kHeaderSize, 0)
 
   DEFINE_FIELD_OFFSET_CONSTANTS(JSObject::kHeaderSize,
@@ -570,6 +567,11 @@ class WasmInstanceObject : public JSObject {
   static wasm::WasmValue GetGlobalValue(Handle<WasmInstanceObject>,
                                         const wasm::WasmGlobal&);
 
+  // Get the name of a global in the given instance by index.
+  static MaybeHandle<String> GetGlobalNameOrNull(Isolate*,
+                                                 Handle<WasmInstanceObject>,
+                                                 uint32_t global_index);
+
   OBJECT_CONSTRUCTORS(WasmInstanceObject, JSObject);
 
  private:
@@ -641,7 +643,7 @@ class WasmExportedFunction : public JSFunction {
 
   Address GetWasmCallTarget();
 
-  wasm::FunctionSig* sig();
+  const wasm::FunctionSig* sig();
 
   DECL_CAST(WasmExportedFunction)
   OBJECT_CONSTRUCTORS(WasmExportedFunction, JSFunction);
@@ -653,14 +655,15 @@ class WasmJSFunction : public JSFunction {
  public:
   static bool IsWasmJSFunction(Object object);
 
-  static Handle<WasmJSFunction> New(Isolate* isolate, wasm::FunctionSig* sig,
+  static Handle<WasmJSFunction> New(Isolate* isolate,
+                                    const wasm::FunctionSig* sig,
                                     Handle<JSReceiver> callable);
 
   JSReceiver GetCallable() const;
   // Deserializes the signature of this function using the provided zone. Note
   // that lifetime of the signature is hence directly coupled to the zone.
-  wasm::FunctionSig* GetSignature(Zone* zone);
-  bool MatchesSignature(wasm::FunctionSig* sig);
+  const wasm::FunctionSig* GetSignature(Zone* zone);
+  bool MatchesSignature(const wasm::FunctionSig* sig);
 
   DECL_CAST(WasmJSFunction)
   OBJECT_CONSTRUCTORS(WasmJSFunction, JSFunction);
@@ -881,8 +884,14 @@ class WasmDebugInfo : public Struct {
                                               Address frame_pointer,
                                               int frame_index);
 
+  // Get stack scope details for a specific interpreted frame. It contains
+  // information about stack values.
+  static Handle<JSObject> GetStackScopeObject(Handle<WasmDebugInfo>,
+                                              Address frame_pointer,
+                                              int frame_index);
+
   V8_EXPORT_PRIVATE static Handle<Code> GetCWasmEntry(Handle<WasmDebugInfo>,
-                                                      wasm::FunctionSig*);
+                                                      const wasm::FunctionSig*);
 
   OBJECT_CONSTRUCTORS(WasmDebugInfo, Struct);
 };
@@ -953,11 +962,6 @@ class WasmExceptionTag
   V8_EXPORT_PRIVATE static Handle<WasmExceptionTag> New(Isolate* isolate,
                                                         int index);
 
-  // Note that this index is only useful for debugging purposes and it is not
-  // unique across modules. The GC however does not allow objects without at
-  // least one field, hence this also serves as a padding field for now.
-  DECL_INT_ACCESSORS(index)
-
   DECL_PRINTER(WasmExceptionTag)
 
   TQ_OBJECT_CONSTRUCTORS(WasmExceptionTag)
diff --git a/deps/v8/src/wasm/wasm-objects.tq b/deps/v8/src/wasm/wasm-objects.tq
index adb3c18cd5..8eda9aba2e 100644
--- a/deps/v8/src/wasm/wasm-objects.tq
+++ b/deps/v8/src/wasm/wasm-objects.tq
@@ -51,6 +51,9 @@ extern class WasmDebugInfo extends Struct {
 
 @generateCppClass
 extern class WasmExceptionTag extends Struct {
+  // Note that this index is only useful for debugging purposes and it is not
+  // unique across modules. The GC however does not allow objects without at
+  // least one field, hence this also serves as a padding field for now.
   index: Smi;
 }
 
@@ -74,11 +77,17 @@ extern class WasmMemoryObject extends JSObject {
   instances: WeakArrayList|Undefined;
 }
 
+type WasmValueType extends uint8 constexpr 'wasm::ValueType::Kind';
+bitfield struct WasmGlobalObjectFlags extends uint31 {
+  Type: WasmValueType: 8 bit;  // "type" is a reserved word.
+  is_mutable: bool: 1 bit;
+}
+
 extern class WasmGlobalObject extends JSObject {
   untagged_buffer: JSArrayBuffer|Undefined;
   tagged_buffer: FixedArray|Undefined;
   offset: Smi;
-  flags: Smi;
+  flags: SmiTagged<WasmGlobalObjectFlags>;
 }
 
 extern class WasmExceptionObject extends JSObject {
diff --git a/deps/v8/src/wasm/wasm-opcodes.cc b/deps/v8/src/wasm/wasm-opcodes.cc
index 7af21cf8a1..769eba35a1 100644
--- a/deps/v8/src/wasm/wasm-opcodes.cc
+++ b/deps/v8/src/wasm/wasm-opcodes.cc
@@ -43,8 +43,11 @@ namespace wasm {
 #define CASE_FLOAT_OP(name, str) CASE_F32_OP(name, str) CASE_F64_OP(name, str)
 #define CASE_ALL_OP(name, str) CASE_FLOAT_OP(name, str) CASE_INT_OP(name, str)
 #define CASE_SIMD_OP(name, str)                                              \
-  CASE_F32x4_OP(name, str) CASE_I32x4_OP(name, str) CASE_I16x8_OP(name, str) \
-      CASE_I8x16_OP(name, str)
+  CASE_F64x2_OP(name, str) CASE_I64x2_OP(name, str) CASE_F32x4_OP(name, str) \
+      CASE_I32x4_OP(name, str) CASE_I16x8_OP(name, str)                      \
+          CASE_I8x16_OP(name, str)
+#define CASE_SIMDF_OP(name, str) \
+  CASE_F32x4_OP(name, str) CASE_F64x2_OP(name, str)
 #define CASE_SIMDI_OP(name, str) \
   CASE_I32x4_OP(name, str) CASE_I16x8_OP(name, str) CASE_I8x16_OP(name, str)
 #define CASE_SIGN_OP(TYPE, name, str) \
@@ -222,45 +225,23 @@ const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     // SIMD opcodes.
     CASE_SIMD_OP(Splat, "splat")
     CASE_SIMD_OP(Neg, "neg")
-    CASE_F64x2_OP(Neg, "neg")
-    CASE_F64x2_OP(Sqrt, "sqrt")
-    CASE_F32x4_OP(Sqrt, "sqrt")
-    CASE_I64x2_OP(Neg, "neg")
+    CASE_SIMDF_OP(Sqrt, "sqrt")
     CASE_SIMD_OP(Eq, "eq")
-    CASE_F64x2_OP(Eq, "eq")
-    CASE_I64x2_OP(Eq, "eq")
     CASE_SIMD_OP(Ne, "ne")
-    CASE_F64x2_OP(Ne, "ne")
-    CASE_I64x2_OP(Ne, "ne")
     CASE_SIMD_OP(Add, "add")
-    CASE_F64x2_OP(Add, "add")
-    CASE_I64x2_OP(Add, "add")
     CASE_SIMD_OP(Sub, "sub")
-    CASE_F64x2_OP(Sub, "sub")
-    CASE_I64x2_OP(Sub, "sub")
     CASE_SIMD_OP(Mul, "mul")
-    CASE_F64x2_OP(Mul, "mul")
-    CASE_I64x2_OP(Mul, "mul")
-    CASE_F64x2_OP(Div, "div")
-    CASE_F32x4_OP(Div, "div")
-    CASE_F64x2_OP(Splat, "splat")
-    CASE_F64x2_OP(Lt, "lt")
-    CASE_F64x2_OP(Le, "le")
-    CASE_F64x2_OP(Gt, "gt")
-    CASE_F64x2_OP(Ge, "ge")
-    CASE_F64x2_OP(Abs, "abs")
-    CASE_F32x4_OP(Abs, "abs")
+    CASE_SIMDF_OP(Div, "div")
+    CASE_SIMDF_OP(Lt, "lt")
+    CASE_SIMDF_OP(Le, "le")
+    CASE_SIMDF_OP(Gt, "gt")
+    CASE_SIMDF_OP(Ge, "ge")
+    CASE_SIMDF_OP(Abs, "abs")
     CASE_F32x4_OP(AddHoriz, "add_horizontal")
     CASE_F32x4_OP(RecipApprox, "recip_approx")
     CASE_F32x4_OP(RecipSqrtApprox, "recip_sqrt_approx")
-    CASE_F64x2_OP(Min, "min")
-    CASE_F32x4_OP(Min, "min")
-    CASE_F64x2_OP(Max, "max")
-    CASE_F32x4_OP(Max, "max")
-    CASE_F32x4_OP(Lt, "lt")
-    CASE_F32x4_OP(Le, "le")
-    CASE_F32x4_OP(Gt, "gt")
-    CASE_F32x4_OP(Ge, "ge")
+    CASE_SIMDF_OP(Min, "min")
+    CASE_SIMDF_OP(Max, "max")
     CASE_CONVERT_OP(Convert, F32x4, I32x4, "i32", "convert")
     CASE_CONVERT_OP(Convert, I32x4, F32x4, "f32", "convert")
     CASE_CONVERT_OP(Convert, I32x4, I16x8Low, "i32", "convert")
@@ -269,10 +250,8 @@ const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_CONVERT_OP(Convert, I16x8, I8x16Low, "i32", "convert")
     CASE_CONVERT_OP(Convert, I16x8, I8x16High, "i32", "convert")
     CASE_CONVERT_OP(Convert, I8x16, I16x8, "i32", "convert")
-    CASE_F64x2_OP(ExtractLane, "extract_lane")
-    CASE_F64x2_OP(ReplaceLane, "replace_lane")
-    CASE_F32x4_OP(ExtractLane, "extract_lane")
-    CASE_F32x4_OP(ReplaceLane, "replace_lane")
+    CASE_SIMDF_OP(ExtractLane, "extract_lane")
+    CASE_SIMDF_OP(ReplaceLane, "replace_lane")
     CASE_I64x2_OP(ExtractLane, "extract_lane")
     CASE_I64x2_OP(ReplaceLane, "replace_lane")
     CASE_I32x4_OP(ExtractLane, "extract_lane")
@@ -295,7 +274,6 @@ const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_SIGN_OP(I64x2, Shr, "shr")
     CASE_SIMDI_OP(Shl, "shl")
     CASE_I64x2_OP(Shl, "shl")
-    CASE_I64x2_OP(Splat, "splat")
     CASE_I32x4_OP(AddHoriz, "add_horizontal")
     CASE_I16x8_OP(AddHoriz, "add_horizontal")
     CASE_SIGN_OP(I16x8, AddSaturate, "add_saturate")
@@ -318,10 +296,8 @@ const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_S1x8_OP(AllTrue, "all_true")
     CASE_S1x16_OP(AnyTrue, "any_true")
     CASE_S1x16_OP(AllTrue, "all_true")
-    CASE_F64x2_OP(Qfma, "qfma")
-    CASE_F64x2_OP(Qfms, "qfms")
-    CASE_F32x4_OP(Qfma, "qfma")
-    CASE_F32x4_OP(Qfms, "qfms")
+    CASE_SIMDF_OP(Qfma, "qfma")
+    CASE_SIMDF_OP(Qfms, "qfms")
 
     CASE_S8x16_OP(LoadSplat, "load_splat")
     CASE_S16x8_OP(LoadSplat, "load_splat")
@@ -337,6 +313,14 @@ const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_I8x16_OP(RoundingAverageU, "avgr_u")
     CASE_I16x8_OP(RoundingAverageU, "avgr_u")
 
+    CASE_I8x16_OP(Abs, "abs")
+    CASE_I16x8_OP(Abs, "abs")
+    CASE_I32x4_OP(Abs, "abs")
+
+    CASE_I8x16_OP(BitMask, "bitmask")
+    CASE_I16x8_OP(BitMask, "bitmask")
+    CASE_I32x4_OP(BitMask, "bitmask")
+
     // Atomic operations.
     CASE_OP(AtomicNotify, "atomic.notify")
     CASE_INT_OP(AtomicWait, "atomic.wait")
@@ -425,6 +409,19 @@ bool WasmOpcodes::IsUnconditionalJump(WasmOpcode opcode) {
   }
 }
 
+bool WasmOpcodes::IsBreakable(WasmOpcode opcode) {
+  switch (opcode) {
+    case kExprBlock:
+    case kExprTry:
+    case kExprCatch:
+    case kExprLoop:
+    case kExprElse:
+      return false;
+    default:
+      return true;
+  }
+}
+
 bool WasmOpcodes::IsAnyRefOpcode(WasmOpcode opcode) {
   switch (opcode) {
     case kExprRefNull:
@@ -449,15 +446,26 @@ bool WasmOpcodes::IsThrowingOpcode(WasmOpcode opcode) {
   }
 }
 
+bool WasmOpcodes::IsSimdPostMvpOpcode(WasmOpcode opcode) {
+  switch (opcode) {
+#define CHECK_OPCODE(name, opcode, _) case kExpr##name:
+    FOREACH_SIMD_POST_MVP_OPCODE(CHECK_OPCODE)
+#undef CHECK_OPCODE
+    return true;
+    default:
+      return false;
+  }
+}
+
 std::ostream& operator<<(std::ostream& os, const FunctionSig& sig) {
   if (sig.return_count() == 0) os << "v";
   for (auto ret : sig.returns()) {
-    os << ValueTypes::ShortNameOf(ret);
+    os << ret.short_name();
   }
   os << "_";
   if (sig.parameter_count() == 0) os << "v";
   for (auto param : sig.parameters()) {
-    os << ValueTypes::ShortNameOf(param);
+    os << param.short_name();
   }
   return os;
 }
@@ -545,29 +553,25 @@ constexpr std::array<WasmOpcodeSig, 256> kNumericExprSigTable =
 
 }  // namespace
 
-FunctionSig* WasmOpcodes::Signature(WasmOpcode opcode) {
+const FunctionSig* WasmOpcodes::Signature(WasmOpcode opcode) {
   switch (opcode >> 8) {
     case 0:
-      return const_cast<FunctionSig*>(kCachedSigs[kShortSigTable[opcode]]);
+      return kCachedSigs[kShortSigTable[opcode]];
     case kSimdPrefix:
-      return const_cast<FunctionSig*>(
-          kCachedSigs[kSimdExprSigTable[opcode & 0xFF]]);
+      return kCachedSigs[kSimdExprSigTable[opcode & 0xFF]];
     case kAtomicPrefix:
-      return const_cast<FunctionSig*>(
-          kCachedSigs[kAtomicExprSigTable[opcode & 0xFF]]);
+      return kCachedSigs[kAtomicExprSigTable[opcode & 0xFF]];
     case kNumericPrefix:
-      return const_cast<FunctionSig*>(
-          kCachedSigs[kNumericExprSigTable[opcode & 0xFF]]);
+      return kCachedSigs[kNumericExprSigTable[opcode & 0xFF]];
     default:
       UNREACHABLE();  // invalid prefix.
       return nullptr;
   }
 }
 
-FunctionSig* WasmOpcodes::AsmjsSignature(WasmOpcode opcode) {
+const FunctionSig* WasmOpcodes::AsmjsSignature(WasmOpcode opcode) {
   DCHECK_GT(kSimpleAsmjsExprSigTable.size(), opcode);
-  return const_cast<FunctionSig*>(
-      kCachedSigs[kSimpleAsmjsExprSigTable[opcode]]);
+  return kCachedSigs[kSimpleAsmjsExprSigTable[opcode]];
 }
 
 // Define constexpr arrays.
diff --git a/deps/v8/src/wasm/wasm-opcodes.h b/deps/v8/src/wasm/wasm-opcodes.h
index 53fe21f30f..d5c1644824 100644
--- a/deps/v8/src/wasm/wasm-opcodes.h
+++ b/deps/v8/src/wasm/wasm-opcodes.h
@@ -265,191 +265,199 @@ bool IsJSCompatibleSignature(const FunctionSig* sig, const WasmFeatures&);
 
 #define FOREACH_SIMD_MEM_OPCODE(V) \
   V(S128LoadMem, 0xfd00, s_i)      \
-  V(S128StoreMem, 0xfd01, v_is)
+  V(S128StoreMem, 0xfd01, v_is)    \
+  V(S8x16LoadSplat, 0xfdc2, s_i)   \
+  V(S16x8LoadSplat, 0xfdc3, s_i)   \
+  V(S32x4LoadSplat, 0xfdc4, s_i)   \
+  V(S64x2LoadSplat, 0xfdc5, s_i)   \
+  V(I16x8Load8x8S, 0xfdd2, s_i)    \
+  V(I16x8Load8x8U, 0xfdd3, s_i)    \
+  V(I32x4Load16x4S, 0xfdd4, s_i)   \
+  V(I32x4Load16x4U, 0xfdd5, s_i)   \
+  V(I64x2Load32x2S, 0xfdd6, s_i)   \
+  V(I64x2Load32x2U, 0xfdd7, s_i)
 
 #define FOREACH_SIMD_MASK_OPERAND_OPCODE(V) V(S8x16Shuffle, 0xfd03, s_ss)
 
-#define FOREACH_SIMD_0_OPERAND_OPCODE(V) \
-  V(I8x16Splat, 0xfd04, s_i)             \
-  V(I16x8Splat, 0xfd08, s_i)             \
-  V(I32x4Splat, 0xfd0c, s_i)             \
-  V(I64x2Splat, 0xfd0f, s_l)             \
-  V(F32x4Splat, 0xfd12, s_f)             \
-  V(F64x2Splat, 0xfd15, s_d)             \
-  V(I8x16Eq, 0xfd18, s_ss)               \
-  V(I8x16Ne, 0xfd19, s_ss)               \
-  V(I8x16LtS, 0xfd1a, s_ss)              \
-  V(I8x16LtU, 0xfd1b, s_ss)              \
-  V(I8x16GtS, 0xfd1c, s_ss)              \
-  V(I8x16GtU, 0xfd1d, s_ss)              \
-  V(I8x16LeS, 0xfd1e, s_ss)              \
-  V(I8x16LeU, 0xfd1f, s_ss)              \
-  V(I8x16GeS, 0xfd20, s_ss)              \
-  V(I8x16GeU, 0xfd21, s_ss)              \
-  V(I16x8Eq, 0xfd22, s_ss)               \
-  V(I16x8Ne, 0xfd23, s_ss)               \
-  V(I16x8LtS, 0xfd24, s_ss)              \
-  V(I16x8LtU, 0xfd25, s_ss)              \
-  V(I16x8GtS, 0xfd26, s_ss)              \
-  V(I16x8GtU, 0xfd27, s_ss)              \
-  V(I16x8LeS, 0xfd28, s_ss)              \
-  V(I16x8LeU, 0xfd29, s_ss)              \
-  V(I16x8GeS, 0xfd2a, s_ss)              \
-  V(I16x8GeU, 0xfd2b, s_ss)              \
-  V(I32x4Eq, 0xfd2c, s_ss)               \
-  V(I32x4Ne, 0xfd2d, s_ss)               \
-  V(I32x4LtS, 0xfd2e, s_ss)              \
-  V(I32x4LtU, 0xfd2f, s_ss)              \
-  V(I32x4GtS, 0xfd30, s_ss)              \
-  V(I32x4GtU, 0xfd31, s_ss)              \
-  V(I32x4LeS, 0xfd32, s_ss)              \
-  V(I32x4LeU, 0xfd33, s_ss)              \
-  V(I32x4GeS, 0xfd34, s_ss)              \
-  V(I32x4GeU, 0xfd35, s_ss)              \
-  V(I64x2Eq, 0xfd36, s_ss)               \
-  V(I64x2Ne, 0xfd37, s_ss)               \
-  V(I64x2LtS, 0xfd38, s_ss)              \
-  V(I64x2LtU, 0xfd39, s_ss)              \
-  V(I64x2GtS, 0xfd3a, s_ss)              \
-  V(I64x2GtU, 0xfd3b, s_ss)              \
-  V(I64x2LeS, 0xfd3c, s_ss)              \
-  V(I64x2LeU, 0xfd3d, s_ss)              \
-  V(I64x2GeS, 0xfd3e, s_ss)              \
-  V(I64x2GeU, 0xfd3f, s_ss)              \
-  V(F32x4Eq, 0xfd40, s_ss)               \
-  V(F32x4Ne, 0xfd41, s_ss)               \
-  V(F32x4Lt, 0xfd42, s_ss)               \
-  V(F32x4Gt, 0xfd43, s_ss)               \
-  V(F32x4Le, 0xfd44, s_ss)               \
-  V(F32x4Ge, 0xfd45, s_ss)               \
-  V(F64x2Eq, 0xfd46, s_ss)               \
-  V(F64x2Ne, 0xfd47, s_ss)               \
-  V(F64x2Lt, 0xfd48, s_ss)               \
-  V(F64x2Gt, 0xfd49, s_ss)               \
-  V(F64x2Le, 0xfd4a, s_ss)               \
-  V(F64x2Ge, 0xfd4b, s_ss)               \
-  V(S128Not, 0xfd4c, s_s)                \
-  V(S128And, 0xfd4d, s_ss)               \
-  V(S128Or, 0xfd4e, s_ss)                \
-  V(S128Xor, 0xfd4f, s_ss)               \
-  V(S128Select, 0xfd50, s_sss)           \
-  V(I8x16Neg, 0xfd51, s_s)               \
-  V(S1x16AnyTrue, 0xfd52, i_s)           \
-  V(S1x16AllTrue, 0xfd53, i_s)           \
-  V(I8x16Shl, 0xfd54, s_si)              \
-  V(I8x16ShrS, 0xfd55, s_si)             \
-  V(I8x16ShrU, 0xfd56, s_si)             \
-  V(I8x16Add, 0xfd57, s_ss)              \
-  V(I8x16AddSaturateS, 0xfd58, s_ss)     \
-  V(I8x16AddSaturateU, 0xfd59, s_ss)     \
-  V(I8x16Sub, 0xfd5a, s_ss)              \
-  V(I8x16SubSaturateS, 0xfd5b, s_ss)     \
-  V(I8x16SubSaturateU, 0xfd5c, s_ss)     \
-  V(I8x16Mul, 0xfd5d, s_ss)              \
-  V(I8x16MinS, 0xfd5e, s_ss)             \
-  V(I8x16MinU, 0xfd5f, s_ss)             \
-  V(I8x16MaxS, 0xfd60, s_ss)             \
-  V(I8x16MaxU, 0xfd61, s_ss)             \
-  V(I16x8Neg, 0xfd62, s_s)               \
-  V(S1x8AnyTrue, 0xfd63, i_s)            \
-  V(S1x8AllTrue, 0xfd64, i_s)            \
-  V(I16x8Shl, 0xfd65, s_si)              \
-  V(I16x8ShrS, 0xfd66, s_si)             \
-  V(I16x8ShrU, 0xfd67, s_si)             \
-  V(I16x8Add, 0xfd68, s_ss)              \
-  V(I16x8AddSaturateS, 0xfd69, s_ss)     \
-  V(I16x8AddSaturateU, 0xfd6a, s_ss)     \
-  V(I16x8Sub, 0xfd6b, s_ss)              \
-  V(I16x8SubSaturateS, 0xfd6c, s_ss)     \
-  V(I16x8SubSaturateU, 0xfd6d, s_ss)     \
-  V(I16x8Mul, 0xfd6e, s_ss)              \
-  V(I16x8MinS, 0xfd6f, s_ss)             \
-  V(I16x8MinU, 0xfd70, s_ss)             \
-  V(I16x8MaxS, 0xfd71, s_ss)             \
-  V(I16x8MaxU, 0xfd72, s_ss)             \
-  V(I32x4Neg, 0xfd73, s_s)               \
-  V(S1x4AnyTrue, 0xfd74, i_s)            \
-  V(S1x4AllTrue, 0xfd75, i_s)            \
-  V(I32x4Shl, 0xfd76, s_si)              \
-  V(I32x4ShrS, 0xfd77, s_si)             \
-  V(I32x4ShrU, 0xfd78, s_si)             \
-  V(I32x4Add, 0xfd79, s_ss)              \
-  V(I32x4Sub, 0xfd7c, s_ss)              \
-  V(I32x4Mul, 0xfd7f, s_ss)              \
-  V(I32x4MinS, 0xfd80, s_ss)             \
-  V(I32x4MinU, 0xfd81, s_ss)             \
-  V(I32x4MaxS, 0xfd82, s_ss)             \
-  V(I32x4MaxU, 0xfd83, s_ss)             \
-  V(I64x2Neg, 0xfd84, s_s)               \
-  V(S1x2AnyTrue, 0xfd85, i_s)            \
-  V(S1x2AllTrue, 0xfd86, i_s)            \
-  V(I64x2Shl, 0xfd87, s_si)              \
-  V(I64x2ShrS, 0xfd88, s_si)             \
-  V(I64x2ShrU, 0xfd89, s_si)             \
-  V(I64x2Add, 0xfd8a, s_ss)              \
-  V(I64x2Sub, 0xfd8d, s_ss)              \
-  V(I64x2Mul, 0xfd8c, s_ss)              \
-  V(I64x2MinS, 0xfd8e, s_ss)             \
-  V(I64x2MinU, 0xfd8f, s_ss)             \
-  V(I64x2MaxS, 0xfd90, s_ss)             \
-  V(I64x2MaxU, 0xfd91, s_ss)             \
-  V(F32x4Abs, 0xfd95, s_s)               \
-  V(F32x4Neg, 0xfd96, s_s)               \
-  V(F32x4Sqrt, 0xfd97, s_s)              \
-  V(F32x4Qfma, 0xfd98, s_sss)            \
-  V(F32x4Qfms, 0xfd99, s_sss)            \
-  V(F32x4Add, 0xfd9a, s_ss)              \
-  V(F32x4Sub, 0xfd9b, s_ss)              \
-  V(F32x4Mul, 0xfd9c, s_ss)              \
-  V(F32x4Div, 0xfd9d, s_ss)              \
-  V(F32x4Min, 0xfd9e, s_ss)              \
-  V(F32x4Max, 0xfd9f, s_ss)              \
-  V(F64x2Abs, 0xfda0, s_s)               \
-  V(F64x2Neg, 0xfda1, s_s)               \
-  V(F64x2Sqrt, 0xfda2, s_s)              \
-  V(F64x2Qfma, 0xfda3, s_sss)            \
-  V(F64x2Qfms, 0xfda4, s_sss)            \
-  V(F64x2Add, 0xfda5, s_ss)              \
-  V(F64x2Sub, 0xfda6, s_ss)              \
-  V(F64x2Mul, 0xfda7, s_ss)              \
-  V(F64x2Div, 0xfda8, s_ss)              \
-  V(F64x2Min, 0xfda9, s_ss)              \
-  V(F64x2Max, 0xfdaa, s_ss)              \
-  V(I32x4SConvertF32x4, 0xfdab, s_s)     \
-  V(I32x4UConvertF32x4, 0xfdac, s_s)     \
-  V(F32x4SConvertI32x4, 0xfdaf, s_s)     \
-  V(F32x4UConvertI32x4, 0xfdb0, s_s)     \
-  V(S8x16Swizzle, 0xfdc0, s_ss)          \
-  V(S8x16LoadSplat, 0xfdc2, s_i)         \
-  V(S16x8LoadSplat, 0xfdc3, s_i)         \
-  V(S32x4LoadSplat, 0xfdc4, s_i)         \
-  V(S64x2LoadSplat, 0xfdc5, s_i)         \
-  V(I8x16SConvertI16x8, 0xfdc6, s_ss)    \
-  V(I8x16UConvertI16x8, 0xfdc7, s_ss)    \
-  V(I16x8SConvertI32x4, 0xfdc8, s_ss)    \
-  V(I16x8UConvertI32x4, 0xfdc9, s_ss)    \
-  V(I16x8SConvertI8x16Low, 0xfdca, s_s)  \
-  V(I16x8SConvertI8x16High, 0xfdcb, s_s) \
-  V(I16x8UConvertI8x16Low, 0xfdcc, s_s)  \
-  V(I16x8UConvertI8x16High, 0xfdcd, s_s) \
-  V(I32x4SConvertI16x8Low, 0xfdce, s_s)  \
-  V(I32x4SConvertI16x8High, 0xfdcf, s_s) \
-  V(I32x4UConvertI16x8Low, 0xfdd0, s_s)  \
-  V(I32x4UConvertI16x8High, 0xfdd1, s_s) \
-  V(I16x8Load8x8S, 0xfdd2, s_s)          \
-  V(I16x8Load8x8U, 0xfdd3, s_s)          \
-  V(I32x4Load16x4S, 0xfdd4, s_s)         \
-  V(I32x4Load16x4U, 0xfdd5, s_s)         \
-  V(I64x2Load32x2S, 0xfdd6, s_s)         \
-  V(I64x2Load32x2U, 0xfdd7, s_s)         \
-  V(S128AndNot, 0xfdd8, s_ss)            \
-  V(I8x16RoundingAverageU, 0xfdd9, s_ss) \
-  V(I16x8RoundingAverageU, 0xfdda, s_ss) \
-  V(I16x8AddHoriz, 0xfdbd, s_ss)         \
-  V(I32x4AddHoriz, 0xfdbe, s_ss)         \
-  V(F32x4AddHoriz, 0xfdbf, s_ss)         \
-  V(F32x4RecipApprox, 0xfde0, s_s)       \
-  V(F32x4RecipSqrtApprox, 0xfde1, s_s)
+#define FOREACH_SIMD_MVP_0_OPERAND_OPCODE(V) \
+  V(I8x16Splat, 0xfd04, s_i)                 \
+  V(I16x8Splat, 0xfd08, s_i)                 \
+  V(I32x4Splat, 0xfd0c, s_i)                 \
+  V(I64x2Splat, 0xfd0f, s_l)                 \
+  V(F32x4Splat, 0xfd12, s_f)                 \
+  V(F64x2Splat, 0xfd15, s_d)                 \
+  V(I8x16Eq, 0xfd18, s_ss)                   \
+  V(I8x16Ne, 0xfd19, s_ss)                   \
+  V(I8x16LtS, 0xfd1a, s_ss)                  \
+  V(I8x16LtU, 0xfd1b, s_ss)                  \
+  V(I8x16GtS, 0xfd1c, s_ss)                  \
+  V(I8x16GtU, 0xfd1d, s_ss)                  \
+  V(I8x16LeS, 0xfd1e, s_ss)                  \
+  V(I8x16LeU, 0xfd1f, s_ss)                  \
+  V(I8x16GeS, 0xfd20, s_ss)                  \
+  V(I8x16GeU, 0xfd21, s_ss)                  \
+  V(I16x8Eq, 0xfd22, s_ss)                   \
+  V(I16x8Ne, 0xfd23, s_ss)                   \
+  V(I16x8LtS, 0xfd24, s_ss)                  \
+  V(I16x8LtU, 0xfd25, s_ss)                  \
+  V(I16x8GtS, 0xfd26, s_ss)                  \
+  V(I16x8GtU, 0xfd27, s_ss)                  \
+  V(I16x8LeS, 0xfd28, s_ss)                  \
+  V(I16x8LeU, 0xfd29, s_ss)                  \
+  V(I16x8GeS, 0xfd2a, s_ss)                  \
+  V(I16x8GeU, 0xfd2b, s_ss)                  \
+  V(I32x4Eq, 0xfd2c, s_ss)                   \
+  V(I32x4Ne, 0xfd2d, s_ss)                   \
+  V(I32x4LtS, 0xfd2e, s_ss)                  \
+  V(I32x4LtU, 0xfd2f, s_ss)                  \
+  V(I32x4GtS, 0xfd30, s_ss)                  \
+  V(I32x4GtU, 0xfd31, s_ss)                  \
+  V(I32x4LeS, 0xfd32, s_ss)                  \
+  V(I32x4LeU, 0xfd33, s_ss)                  \
+  V(I32x4GeS, 0xfd34, s_ss)                  \
+  V(I32x4GeU, 0xfd35, s_ss)                  \
+  V(F32x4Eq, 0xfd40, s_ss)                   \
+  V(F32x4Ne, 0xfd41, s_ss)                   \
+  V(F32x4Lt, 0xfd42, s_ss)                   \
+  V(F32x4Gt, 0xfd43, s_ss)                   \
+  V(F32x4Le, 0xfd44, s_ss)                   \
+  V(F32x4Ge, 0xfd45, s_ss)                   \
+  V(F64x2Eq, 0xfd46, s_ss)                   \
+  V(F64x2Ne, 0xfd47, s_ss)                   \
+  V(F64x2Lt, 0xfd48, s_ss)                   \
+  V(F64x2Gt, 0xfd49, s_ss)                   \
+  V(F64x2Le, 0xfd4a, s_ss)                   \
+  V(F64x2Ge, 0xfd4b, s_ss)                   \
+  V(S128Not, 0xfd4c, s_s)                    \
+  V(S128And, 0xfd4d, s_ss)                   \
+  V(S128Or, 0xfd4e, s_ss)                    \
+  V(S128Xor, 0xfd4f, s_ss)                   \
+  V(S128Select, 0xfd50, s_sss)               \
+  V(I8x16Neg, 0xfd51, s_s)                   \
+  V(S1x16AnyTrue, 0xfd52, i_s)               \
+  V(S1x16AllTrue, 0xfd53, i_s)               \
+  V(I8x16Shl, 0xfd54, s_si)                  \
+  V(I8x16ShrS, 0xfd55, s_si)                 \
+  V(I8x16ShrU, 0xfd56, s_si)                 \
+  V(I8x16Add, 0xfd57, s_ss)                  \
+  V(I8x16AddSaturateS, 0xfd58, s_ss)         \
+  V(I8x16AddSaturateU, 0xfd59, s_ss)         \
+  V(I8x16Sub, 0xfd5a, s_ss)                  \
+  V(I8x16SubSaturateS, 0xfd5b, s_ss)         \
+  V(I8x16SubSaturateU, 0xfd5c, s_ss)         \
+  V(I8x16Mul, 0xfd5d, s_ss)                  \
+  V(I8x16MinS, 0xfd5e, s_ss)                 \
+  V(I8x16MinU, 0xfd5f, s_ss)                 \
+  V(I8x16MaxS, 0xfd60, s_ss)                 \
+  V(I8x16MaxU, 0xfd61, s_ss)                 \
+  V(I16x8Neg, 0xfd62, s_s)                   \
+  V(S1x8AnyTrue, 0xfd63, i_s)                \
+  V(S1x8AllTrue, 0xfd64, i_s)                \
+  V(I16x8Shl, 0xfd65, s_si)                  \
+  V(I16x8ShrS, 0xfd66, s_si)                 \
+  V(I16x8ShrU, 0xfd67, s_si)                 \
+  V(I16x8Add, 0xfd68, s_ss)                  \
+  V(I16x8AddSaturateS, 0xfd69, s_ss)         \
+  V(I16x8AddSaturateU, 0xfd6a, s_ss)         \
+  V(I16x8Sub, 0xfd6b, s_ss)                  \
+  V(I16x8SubSaturateS, 0xfd6c, s_ss)         \
+  V(I16x8SubSaturateU, 0xfd6d, s_ss)         \
+  V(I16x8Mul, 0xfd6e, s_ss)                  \
+  V(I16x8MinS, 0xfd6f, s_ss)                 \
+  V(I16x8MinU, 0xfd70, s_ss)                 \
+  V(I16x8MaxS, 0xfd71, s_ss)                 \
+  V(I16x8MaxU, 0xfd72, s_ss)                 \
+  V(I32x4Neg, 0xfd73, s_s)                   \
+  V(S1x4AnyTrue, 0xfd74, i_s)                \
+  V(S1x4AllTrue, 0xfd75, i_s)                \
+  V(I32x4Shl, 0xfd76, s_si)                  \
+  V(I32x4ShrS, 0xfd77, s_si)                 \
+  V(I32x4ShrU, 0xfd78, s_si)                 \
+  V(I32x4Add, 0xfd79, s_ss)                  \
+  V(I32x4Sub, 0xfd7c, s_ss)                  \
+  V(I32x4Mul, 0xfd7f, s_ss)                  \
+  V(I32x4MinS, 0xfd80, s_ss)                 \
+  V(I32x4MinU, 0xfd81, s_ss)                 \
+  V(I32x4MaxS, 0xfd82, s_ss)                 \
+  V(I32x4MaxU, 0xfd83, s_ss)                 \
+  V(I64x2Neg, 0xfd84, s_s)                   \
+  V(I64x2Shl, 0xfd87, s_si)                  \
+  V(I64x2ShrS, 0xfd88, s_si)                 \
+  V(I64x2ShrU, 0xfd89, s_si)                 \
+  V(I64x2Add, 0xfd8a, s_ss)                  \
+  V(I64x2Sub, 0xfd8d, s_ss)                  \
+  V(I64x2Mul, 0xfd8c, s_ss)                  \
+  V(F32x4Abs, 0xfd95, s_s)                   \
+  V(F32x4Neg, 0xfd96, s_s)                   \
+  V(F32x4Sqrt, 0xfd97, s_s)                  \
+  V(F32x4Add, 0xfd9a, s_ss)                  \
+  V(F32x4Sub, 0xfd9b, s_ss)                  \
+  V(F32x4Mul, 0xfd9c, s_ss)                  \
+  V(F32x4Div, 0xfd9d, s_ss)                  \
+  V(F32x4Min, 0xfd9e, s_ss)                  \
+  V(F32x4Max, 0xfd9f, s_ss)                  \
+  V(F64x2Abs, 0xfda0, s_s)                   \
+  V(F64x2Neg, 0xfda1, s_s)                   \
+  V(F64x2Sqrt, 0xfda2, s_s)                  \
+  V(F64x2Add, 0xfda5, s_ss)                  \
+  V(F64x2Sub, 0xfda6, s_ss)                  \
+  V(F64x2Mul, 0xfda7, s_ss)                  \
+  V(F64x2Div, 0xfda8, s_ss)                  \
+  V(F64x2Min, 0xfda9, s_ss)                  \
+  V(F64x2Max, 0xfdaa, s_ss)                  \
+  V(I32x4SConvertF32x4, 0xfdab, s_s)         \
+  V(I32x4UConvertF32x4, 0xfdac, s_s)         \
+  V(F32x4SConvertI32x4, 0xfdaf, s_s)         \
+  V(F32x4UConvertI32x4, 0xfdb0, s_s)         \
+  V(S8x16Swizzle, 0xfdc0, s_ss)              \
+  V(I8x16SConvertI16x8, 0xfdc6, s_ss)        \
+  V(I8x16UConvertI16x8, 0xfdc7, s_ss)        \
+  V(I16x8SConvertI32x4, 0xfdc8, s_ss)        \
+  V(I16x8UConvertI32x4, 0xfdc9, s_ss)        \
+  V(I16x8SConvertI8x16Low, 0xfdca, s_s)      \
+  V(I16x8SConvertI8x16High, 0xfdcb, s_s)     \
+  V(I16x8UConvertI8x16Low, 0xfdcc, s_s)      \
+  V(I16x8UConvertI8x16High, 0xfdcd, s_s)     \
+  V(I32x4SConvertI16x8Low, 0xfdce, s_s)      \
+  V(I32x4SConvertI16x8High, 0xfdcf, s_s)     \
+  V(I32x4UConvertI16x8Low, 0xfdd0, s_s)      \
+  V(I32x4UConvertI16x8High, 0xfdd1, s_s)     \
+  V(S128AndNot, 0xfdd8, s_ss)                \
+  V(I8x16RoundingAverageU, 0xfdd9, s_ss)     \
+  V(I16x8RoundingAverageU, 0xfdda, s_ss)     \
+  V(I8x16Abs, 0xfde1, s_s)                   \
+  V(I16x8Abs, 0xfde2, s_s)                   \
+  V(I32x4Abs, 0xfde3, s_s)
+
+#define FOREACH_SIMD_POST_MVP_OPCODE(V) \
+  V(I64x2Eq, 0xfd36, s_ss)              \
+  V(I64x2Ne, 0xfd37, s_ss)              \
+  V(I64x2LtS, 0xfd38, s_ss)             \
+  V(I64x2LtU, 0xfd39, s_ss)             \
+  V(I64x2GtS, 0xfd3a, s_ss)             \
+  V(I64x2GtU, 0xfd3b, s_ss)             \
+  V(I64x2LeS, 0xfd3c, s_ss)             \
+  V(I64x2LeU, 0xfd3d, s_ss)             \
+  V(I64x2GeS, 0xfd3e, s_ss)             \
+  V(I64x2GeU, 0xfd3f, s_ss)             \
+  V(S1x2AnyTrue, 0xfd85, i_s)           \
+  V(S1x2AllTrue, 0xfd86, i_s)           \
+  V(I64x2MinS, 0xfd8e, s_ss)            \
+  V(I64x2MinU, 0xfd8f, s_ss)            \
+  V(I64x2MaxS, 0xfd90, s_ss)            \
+  V(I64x2MaxU, 0xfd91, s_ss)            \
+  V(F32x4Qfma, 0xfd98, s_sss)           \
+  V(F32x4Qfms, 0xfd99, s_sss)           \
+  V(F64x2Qfma, 0xfda3, s_sss)           \
+  V(F64x2Qfms, 0xfda4, s_sss)           \
+  V(I16x8AddHoriz, 0xfdbd, s_ss)        \
+  V(I32x4AddHoriz, 0xfdbe, s_ss)        \
+  V(F32x4AddHoriz, 0xfdbf, s_ss)        \
+  V(I8x16BitMask, 0xfde4, i_s)          \
+  V(I16x8BitMask, 0xfde5, i_s)          \
+  V(I32x4BitMask, 0xfde6, i_s)          \
+  V(F32x4RecipApprox, 0xfdee, s_s)      \
+  V(F32x4RecipSqrtApprox, 0xfdef, s_s)
 
 #define FOREACH_SIMD_1_OPERAND_1_PARAM_OPCODE(V) \
   V(I8x16ExtractLaneS, 0xfd05, _)                \
@@ -469,6 +477,10 @@ bool IsJSCompatibleSignature(const FunctionSig* sig, const WasmFeatures&);
   V(F32x4ReplaceLane, 0xfd14, _)                 \
   V(F64x2ReplaceLane, 0xfd17, _)
 
+#define FOREACH_SIMD_0_OPERAND_OPCODE(V) \
+  FOREACH_SIMD_MVP_0_OPERAND_OPCODE(V)   \
+  FOREACH_SIMD_POST_MVP_OPCODE(V)
+
 #define FOREACH_SIMD_1_OPERAND_OPCODE(V)   \
   FOREACH_SIMD_1_OPERAND_1_PARAM_OPCODE(V) \
   FOREACH_SIMD_1_OPERAND_2_PARAM_OPCODE(V)
@@ -664,19 +676,21 @@ enum TrapReason {
 // A collection of opcode-related static methods.
 class V8_EXPORT_PRIVATE WasmOpcodes {
  public:
-  static const char* OpcodeName(WasmOpcode opcode);
-  static FunctionSig* Signature(WasmOpcode opcode);
-  static FunctionSig* AsmjsSignature(WasmOpcode opcode);
-  static bool IsPrefixOpcode(WasmOpcode opcode);
-  static bool IsControlOpcode(WasmOpcode opcode);
-  static bool IsAnyRefOpcode(WasmOpcode opcode);
-  static bool IsThrowingOpcode(WasmOpcode opcode);
+  static const char* OpcodeName(WasmOpcode);
+  static const FunctionSig* Signature(WasmOpcode);
+  static const FunctionSig* AsmjsSignature(WasmOpcode);
+  static bool IsPrefixOpcode(WasmOpcode);
+  static bool IsControlOpcode(WasmOpcode);
+  static bool IsAnyRefOpcode(WasmOpcode);
+  static bool IsThrowingOpcode(WasmOpcode);
+  static bool IsSimdPostMvpOpcode(WasmOpcode);
   // Check whether the given opcode always jumps, i.e. all instructions after
   // this one in the current block are dead. Returns false for |end|.
-  static bool IsUnconditionalJump(WasmOpcode opcode);
+  static bool IsUnconditionalJump(WasmOpcode);
+  static bool IsBreakable(WasmOpcode);
 
-  static MessageTemplate TrapReasonToMessageId(TrapReason reason);
-  static const char* TrapReasonMessage(TrapReason reason);
+  static MessageTemplate TrapReasonToMessageId(TrapReason);
+  static const char* TrapReasonMessage(TrapReason);
 };
 
 // Representation of an initializer expression.
diff --git a/deps/v8/src/wasm/wasm-result.cc b/deps/v8/src/wasm/wasm-result.cc
index 42eee037d5..fc1104b8d0 100644
--- a/deps/v8/src/wasm/wasm-result.cc
+++ b/deps/v8/src/wasm/wasm-result.cc
@@ -155,6 +155,21 @@ ErrorThrower::~ErrorThrower() {
   }
 }
 
+ScheduledErrorThrower::~ScheduledErrorThrower() {
+  // There should never be both a pending and a scheduled exception.
+  DCHECK(!isolate()->has_scheduled_exception() ||
+         !isolate()->has_pending_exception());
+  // Don't throw another error if there is already a scheduled error.
+  if (isolate()->has_scheduled_exception()) {
+    Reset();
+  } else if (isolate()->has_pending_exception()) {
+    Reset();
+    isolate()->OptionalRescheduleException(false);
+  } else if (error()) {
+    isolate()->ScheduleThrow(*Reify());
+  }
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/src/wasm/wasm-result.h b/deps/v8/src/wasm/wasm-result.h
index 92049e6080..784dd0f615 100644
--- a/deps/v8/src/wasm/wasm-result.h
+++ b/deps/v8/src/wasm/wasm-result.h
@@ -168,6 +168,20 @@ class V8_EXPORT_PRIVATE ErrorThrower {
   DISALLOW_COPY_AND_ASSIGN(ErrorThrower);
 };
 
+// Like an ErrorThrower, but turns all pending exceptions into scheduled
+// exceptions when going out of scope. Use this in API methods.
+// Note that pending exceptions are not necessarily created by the ErrorThrower,
+// but e.g. by the wasm start function. There might also be a scheduled
+// exception, created by another API call (e.g. v8::Object::Get). But there
+// should never be both pending and scheduled exceptions.
+class V8_EXPORT_PRIVATE ScheduledErrorThrower : public ErrorThrower {
+ public:
+  ScheduledErrorThrower(i::Isolate* isolate, const char* context)
+      : ErrorThrower(isolate, context) {}
+
+  ~ScheduledErrorThrower();
+};
+
 // Use {nullptr_t} as data value to indicate that this only stores the error,
 // but no result value (the only valid value is {nullptr}).
 // [Storing {void} would require template specialization.]
diff --git a/deps/v8/src/wasm/wasm-serialization.cc b/deps/v8/src/wasm/wasm-serialization.cc
index c736a272b1..773a709721 100644
--- a/deps/v8/src/wasm/wasm-serialization.cc
+++ b/deps/v8/src/wasm/wasm-serialization.cc
@@ -30,7 +30,7 @@ namespace wasm {
 namespace {
 
 // TODO(bbudge) Try to unify the various implementations of readers and writers
-// in WASM, e.g. StreamProcessor and ZoneBuffer, with these.
+// in Wasm, e.g. StreamProcessor and ZoneBuffer, with these.
 class Writer {
  public:
   explicit Writer(Vector<byte> buffer)
@@ -99,16 +99,17 @@ class Reader {
     return value;
   }
 
-  void ReadVector(Vector<byte> v) {
-    if (v.size() > 0) {
-      DCHECK_GE(current_size(), v.size());
-      memcpy(v.begin(), current_location(), v.size());
-      pos_ += v.size();
-    }
+  template <typename T>
+  Vector<const T> ReadVector(size_t size) {
+    DCHECK_GE(current_size(), size);
+    Vector<const byte> bytes{pos_, size * sizeof(T)};
+    pos_ += size * sizeof(T);
     if (FLAG_trace_wasm_serialization) {
-      StdoutStream{} << "read vector of " << v.size() << " elements"
+      StdoutStream{} << "read vector of " << size << " elements of size "
+                     << sizeof(T) << " (total size " << size * sizeof(T) << ")"
                      << std::endl;
     }
+    return Vector<const T>::cast(bytes);
   }
 
   void Skip(size_t size) { pos_ += size; }
@@ -188,21 +189,20 @@ constexpr size_t kHeaderSize =
     sizeof(uint32_t) +  // total wasm function count
     sizeof(uint32_t);   // imported functions (index of first wasm function)
 
-constexpr size_t kCodeHeaderSize =
-    sizeof(size_t) +          // size of code section
-    sizeof(size_t) +          // offset of constant pool
-    sizeof(size_t) +          // offset of safepoint table
-    sizeof(size_t) +          // offset of handler table
-    sizeof(size_t) +          // offset of code comments
-    sizeof(size_t) +          // unpadded binary size
-    sizeof(uint32_t) +        // stack slots
-    sizeof(uint32_t) +        // tagged parameter slots
-    sizeof(size_t) +          // code size
-    sizeof(size_t) +          // reloc size
-    sizeof(size_t) +          // source positions size
-    sizeof(size_t) +          // protected instructions size
-    sizeof(WasmCode::Kind) +  // code kind
-    sizeof(ExecutionTier);    // tier
+constexpr size_t kCodeHeaderSize = sizeof(bool) +  // whether code is present
+                                   sizeof(int) +   // offset of constant pool
+                                   sizeof(int) +   // offset of safepoint table
+                                   sizeof(int) +   // offset of handler table
+                                   sizeof(int) +   // offset of code comments
+                                   sizeof(int) +   // unpadded binary size
+                                   sizeof(int) +   // stack slots
+                                   sizeof(int) +   // tagged parameter slots
+                                   sizeof(int) +   // code size
+                                   sizeof(int) +   // reloc size
+                                   sizeof(int) +   // source positions size
+                                   sizeof(int) +  // protected instructions size
+                                   sizeof(WasmCode::Kind) +  // code kind
+                                   sizeof(ExecutionTier);    // tier
 
 // A List of all isolate-independent external references. This is used to create
 // a tag from the Address of an external reference and vice versa.
@@ -300,13 +300,12 @@ NativeModuleSerializer::NativeModuleSerializer(
 }
 
 size_t NativeModuleSerializer::MeasureCode(const WasmCode* code) const {
-  if (code == nullptr) return sizeof(size_t);
+  if (code == nullptr) return sizeof(bool);
   DCHECK(code->kind() == WasmCode::kFunction ||
          code->kind() == WasmCode::kInterpreterEntry);
   return kCodeHeaderSize + code->instructions().size() +
          code->reloc_info().size() + code->source_positions().size() +
-         code->protected_instructions().size() *
-             sizeof(trap_handler::ProtectedInstructionData);
+         code->protected_instructions_data().size();
 }
 
 size_t NativeModuleSerializer::Measure() const {
@@ -327,13 +326,13 @@ void NativeModuleSerializer::WriteHeader(Writer* writer) {
 
 void NativeModuleSerializer::WriteCode(const WasmCode* code, Writer* writer) {
   if (code == nullptr) {
-    writer->Write(size_t{0});
+    writer->Write(false);
     return;
   }
+  writer->Write(true);
   DCHECK(code->kind() == WasmCode::kFunction ||
          code->kind() == WasmCode::kInterpreterEntry);
   // Write the size of the entire code section, followed by the code header.
-  writer->Write(MeasureCode(code));
   writer->Write(code->constant_pool_offset());
   writer->Write(code->safepoint_table_offset());
   writer->Write(code->handler_table_offset());
@@ -341,10 +340,10 @@ void NativeModuleSerializer::WriteCode(const WasmCode* code, Writer* writer) {
   writer->Write(code->unpadded_binary_size());
   writer->Write(code->stack_slots());
   writer->Write(code->tagged_parameter_slots());
-  writer->Write(code->instructions().size());
-  writer->Write(code->reloc_info().size());
-  writer->Write(code->source_positions().size());
-  writer->Write(code->protected_instructions().size());
+  writer->Write(code->instructions().length());
+  writer->Write(code->reloc_info().length());
+  writer->Write(code->source_positions().length());
+  writer->Write(code->protected_instructions_data().length());
   writer->Write(code->kind());
   writer->Write(code->tier());
 
@@ -356,14 +355,16 @@ void NativeModuleSerializer::WriteCode(const WasmCode* code, Writer* writer) {
   // Write the reloc info, source positions, and protected code.
   writer->WriteVector(code->reloc_info());
   writer->WriteVector(code->source_positions());
-  writer->WriteVector(Vector<byte>::cast(code->protected_instructions()));
+  writer->WriteVector(code->protected_instructions_data());
 #if V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_ARM || \
-    V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_S390X
+    V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_S390X
   // On platforms that don't support misaligned word stores, copy to an aligned
   // buffer if necessary so we can relocate the serialized code.
   std::unique_ptr<byte[]> aligned_buffer;
   if (!IsAligned(reinterpret_cast<Address>(serialized_code_start),
-                 kInt32Size)) {
+                 kSystemPointerSize)) {
+    // 'byte' does not guarantee an alignment but seems to work well enough in
+    // practice.
     aligned_buffer.reset(new byte[code_size]);
     code_start = aligned_buffer.get();
   }
@@ -462,7 +463,7 @@ class V8_EXPORT_PRIVATE NativeModuleDeserializer {
 
  private:
   bool ReadHeader(Reader* reader);
-  bool ReadCode(uint32_t fn_index, Reader* reader);
+  bool ReadCode(int fn_index, Reader* reader);
 
   NativeModule* const native_module_;
   bool read_called_;
@@ -480,6 +481,7 @@ bool NativeModuleDeserializer::Read(Reader* reader) {
   if (!ReadHeader(reader)) return false;
   uint32_t total_fns = native_module_->num_functions();
   uint32_t first_wasm_fn = native_module_->num_imported_functions();
+  WasmCodeRefScope wasm_code_ref_scope;
   for (uint32_t i = first_wasm_fn; i < total_fns; ++i) {
     if (!ReadCode(i, reader)) return false;
   }
@@ -493,46 +495,39 @@ bool NativeModuleDeserializer::ReadHeader(Reader* reader) {
          imports == native_module_->num_imported_functions();
 }
 
-bool NativeModuleDeserializer::ReadCode(uint32_t fn_index, Reader* reader) {
-  size_t code_section_size = reader->Read<size_t>();
-  if (code_section_size == 0) {
+bool NativeModuleDeserializer::ReadCode(int fn_index, Reader* reader) {
+  bool has_code = reader->Read<bool>();
+  if (!has_code) {
     DCHECK(FLAG_wasm_lazy_compilation ||
            native_module_->enabled_features().has_compilation_hints());
     native_module_->UseLazyStub(fn_index);
     return true;
   }
-  size_t constant_pool_offset = reader->Read<size_t>();
-  size_t safepoint_table_offset = reader->Read<size_t>();
-  size_t handler_table_offset = reader->Read<size_t>();
-  size_t code_comment_offset = reader->Read<size_t>();
-  size_t unpadded_binary_size = reader->Read<size_t>();
-  uint32_t stack_slot_count = reader->Read<uint32_t>();
-  uint32_t tagged_parameter_slots = reader->Read<uint32_t>();
-  size_t code_size = reader->Read<size_t>();
-  size_t reloc_size = reader->Read<size_t>();
-  size_t source_position_size = reader->Read<size_t>();
-  size_t protected_instructions_size = reader->Read<size_t>();
+  int constant_pool_offset = reader->Read<int>();
+  int safepoint_table_offset = reader->Read<int>();
+  int handler_table_offset = reader->Read<int>();
+  int code_comment_offset = reader->Read<int>();
+  int unpadded_binary_size = reader->Read<int>();
+  int stack_slot_count = reader->Read<int>();
+  int tagged_parameter_slots = reader->Read<int>();
+  int code_size = reader->Read<int>();
+  int reloc_size = reader->Read<int>();
+  int source_position_size = reader->Read<int>();
+  int protected_instructions_size = reader->Read<int>();
   WasmCode::Kind kind = reader->Read<WasmCode::Kind>();
   ExecutionTier tier = reader->Read<ExecutionTier>();
 
-  Vector<const byte> code_buffer = {reader->current_location(), code_size};
-  reader->Skip(code_size);
-
-  OwnedVector<byte> reloc_info = OwnedVector<byte>::New(reloc_size);
-  reader->ReadVector(reloc_info.as_vector());
-  OwnedVector<byte> source_pos = OwnedVector<byte>::New(source_position_size);
-  reader->ReadVector(source_pos.as_vector());
+  auto code_buffer = reader->ReadVector<byte>(code_size);
+  auto reloc_info = reader->ReadVector<byte>(reloc_size);
+  auto source_pos = reader->ReadVector<byte>(source_position_size);
   auto protected_instructions =
-      OwnedVector<trap_handler::ProtectedInstructionData>::New(
-          protected_instructions_size);
-  reader->ReadVector(Vector<byte>::cast(protected_instructions.as_vector()));
+      reader->ReadVector<byte>(protected_instructions_size);
 
   WasmCode* code = native_module_->AddDeserializedCode(
       fn_index, code_buffer, stack_slot_count, tagged_parameter_slots,
       safepoint_table_offset, handler_table_offset, constant_pool_offset,
-      code_comment_offset, unpadded_binary_size,
-      std::move(protected_instructions), std::move(reloc_info),
-      std::move(source_pos), kind, tier);
+      code_comment_offset, unpadded_binary_size, protected_instructions,
+      std::move(reloc_info), std::move(source_pos), kind, tier);
 
   // Relocate the code.
   int mask = RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
@@ -540,8 +535,8 @@ bool NativeModuleDeserializer::ReadCode(uint32_t fn_index, Reader* reader) {
              RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
              RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
              RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED);
-  auto jump_tables_ref =
-      native_module_->FindJumpTablesForCode(code->instruction_start());
+  auto jump_tables_ref = native_module_->FindJumpTablesForRegion(
+      base::AddressRegionOf(code->instructions()));
   for (RelocIterator iter(code->instructions(), code->reloc_info(),
                           code->constant_pool(), mask);
        !iter.done(); iter.next()) {
@@ -616,12 +611,12 @@ MaybeHandle<WasmModuleObject> DeserializeNativeModule(
   if (decode_result.failed()) return {};
   std::shared_ptr<WasmModule> module = std::move(decode_result.value());
   CHECK_NOT_NULL(module);
-  Handle<Script> script =
-      CreateWasmScript(isolate, wire_bytes, VectorOf(module->source_map_url),
-                       module->name, source_url);
+  Handle<Script> script = CreateWasmScript(isolate, wire_bytes_vec,
+                                           VectorOf(module->source_map_url),
+                                           module->name, source_url);
 
-  auto shared_native_module =
-      wasm_engine->MaybeGetNativeModule(module->origin, wire_bytes_vec);
+  auto shared_native_module = wasm_engine->MaybeGetNativeModule(
+      module->origin, wire_bytes_vec, isolate);
   if (shared_native_module == nullptr) {
     const bool kIncludeLiftoff = false;
     size_t code_size_estimate =
@@ -633,11 +628,9 @@ MaybeHandle<WasmModuleObject> DeserializeNativeModule(
         OwnedVector<uint8_t>::Of(wire_bytes_vec));
 
     NativeModuleDeserializer deserializer(shared_native_module.get());
-    WasmCodeRefScope wasm_code_ref_scope;
-
     Reader reader(data + WasmSerializer::kHeaderSize);
     bool error = !deserializer.Read(&reader);
-    wasm_engine->UpdateNativeModuleCache(shared_native_module, error);
+    wasm_engine->UpdateNativeModuleCache(error, &shared_native_module, isolate);
     if (error) return {};
   }
 
diff --git a/deps/v8/src/wasm/wasm-tier.h b/deps/v8/src/wasm/wasm-tier.h
index b649723479..8434a2e14b 100644
--- a/deps/v8/src/wasm/wasm-tier.h
+++ b/deps/v8/src/wasm/wasm-tier.h
@@ -11,7 +11,7 @@ namespace v8 {
 namespace internal {
 namespace wasm {
 
-// All the tiers of WASM execution.
+// All the tiers of Wasm execution.
 enum class ExecutionTier : int8_t {
   kNone,
   kInterpreter,
diff --git a/deps/v8/test/benchmarks/csuite/csuite.py b/deps/v8/test/benchmarks/csuite/csuite.py
index ce2ad84384..9b0a0e6436 100755
--- a/deps/v8/test/benchmarks/csuite/csuite.py
+++ b/deps/v8/test/benchmarks/csuite/csuite.py
@@ -124,7 +124,7 @@ if __name__ == '__main__':
   # Ensure output directory is setup
   output_path_base = os.path.abspath(os.getcwd())
   output_path = os.path.join(output_path_base, "_results")
-  output_file = os.path.join(output_path, "master")
+  output_file = os.path.join(output_path, "master_" + suite)
   if not os.path.exists(output_path):
     if opts.verbose:
       print("Creating directory %s." % output_path)
diff --git a/deps/v8/test/cctest/BUILD.gn b/deps/v8/test/cctest/BUILD.gn
index ee6407c74b..89fe36f65b 100644
--- a/deps/v8/test/cctest/BUILD.gn
+++ b/deps/v8/test/cctest/BUILD.gn
@@ -14,17 +14,11 @@ config("cctest_config") {
 v8_executable("cctest") {
   testonly = true
 
-  sources = [
-    "cctest.cc",
-  ]
+  sources = [ "cctest.cc" ]
 
-  deps = [
-    ":cctest_sources",
-  ]
+  deps = [ ":cctest_sources" ]
 
-  data_deps = [
-    "../../tools:v8_testrunner",
-  ]
+  data_deps = [ "../../tools:v8_testrunner" ]
 
   data = [
     "testcfg.py",
@@ -35,15 +29,12 @@ v8_executable("cctest") {
   configs = [
     "../..:external_config",
     "../..:internal_config_base",
+    "../..:v8_tracing_config",
     ":cctest_config",
   ]
 
   ldflags = []
 
-  if (v8_use_perfetto) {
-    deps += [ "//third_party/perfetto/include/perfetto/tracing" ]
-  }
-
   # TODO(machenbach): Translate from gyp.
   #["OS=="aix"", {
   #  "ldflags": [ "-Wl,-bbigtoc" ],
@@ -58,9 +49,7 @@ v8_header_set("cctest_headers") {
     "../..:internal_config_base",
   ]
 
-  sources = [
-    "cctest.h",
-  ]
+  sources = [ "cctest.h" ]
 }
 
 v8_source_set("cctest_sources") {
@@ -230,6 +219,7 @@ v8_source_set("cctest_sources") {
     "test-intl.cc",
     "test-js-weak-refs.cc",
     "test-liveedit.cc",
+    "test-local-handles.cc",
     "test-lockers.cc",
     "test-log.cc",
     "test-managed.cc",
@@ -293,6 +283,8 @@ v8_source_set("cctest_sources") {
     "wasm/test-streaming-compilation.cc",
     "wasm/test-wasm-breakpoints.cc",
     "wasm/test-wasm-codegen.cc",
+    "wasm/test-wasm-debug-evaluate.cc",
+    "wasm/test-wasm-debug-evaluate.h",
     "wasm/test-wasm-import-wrapper-cache.cc",
     "wasm/test-wasm-interpreter-entry.cc",
     "wasm/test-wasm-serialization.cc",
@@ -386,6 +378,7 @@ v8_source_set("cctest_sources") {
   configs = [
     "../..:external_config",
     "../..:internal_config_base",
+    "../..:v8_tracing_config",
   ]
 
   public_deps = [
@@ -400,9 +393,7 @@ v8_source_set("cctest_sources") {
   ]
 
   defines = []
-  deps = [
-    "../..:run_torque",
-  ]
+  deps = [ "../..:run_torque" ]
 
   if (v8_enable_i18n_support) {
     defines += [ "V8_INTL_SUPPORT" ]
@@ -432,6 +423,11 @@ v8_source_set("cctest_sources") {
 
     # MSVS wants this for gay-{precision,shortest}.cc.
     cflags += [ "/bigobj" ]
+
+    if (symbol_level == 2) {
+      sources += [ "test-v8windbg.cc" ]
+      deps += [ "../../tools/v8windbg:v8windbg_test" ]
+    }
   }
 
   if (v8_use_perfetto) {
@@ -439,6 +435,7 @@ v8_source_set("cctest_sources") {
       "//third_party/perfetto/include/perfetto/tracing",
       "//third_party/perfetto/protos/perfetto/trace/chrome:lite",
       "//third_party/perfetto/protos/perfetto/trace/chrome:zero",
+      "//third_party/perfetto/src/tracing:in_process_backend",
     ]
   }
 }
@@ -465,7 +462,5 @@ v8_executable("generate-bytecode-expectations") {
     "//build/win:default_exe_manifest",
   ]
 
-  data = [
-    "interpreter/bytecode_expectations/",
-  ]
+  data = [ "interpreter/bytecode_expectations/" ]
 }
diff --git a/deps/v8/test/cctest/cctest.h b/deps/v8/test/cctest/cctest.h
index 8a5a5a6d31..e503b51914 100644
--- a/deps/v8/test/cctest/cctest.h
+++ b/deps/v8/test/cctest/cctest.h
@@ -36,6 +36,7 @@
 #include "src/codegen/register-configuration.h"
 #include "src/debug/debug-interface.h"
 #include "src/execution/isolate.h"
+#include "src/execution/simulator.h"
 #include "src/flags/flags.h"
 #include "src/heap/factory.h"
 #include "src/init/v8.h"
@@ -358,16 +359,13 @@ static inline v8::Local<v8::Integer> v8_int(int32_t x) {
 }
 
 static inline v8::Local<v8::String> v8_str(const char* x) {
-  return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x,
-                                 v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x).ToLocalChecked();
 }
 
 
 static inline v8::Local<v8::String> v8_str(v8::Isolate* isolate,
                                            const char* x) {
-  return v8::String::NewFromUtf8(isolate, x, v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(isolate, x).ToLocalChecked();
 }
 
 
@@ -437,8 +435,7 @@ static inline v8::MaybeLocal<v8::Value> CompileRun(
 static inline v8::Local<v8::Value> CompileRunChecked(v8::Isolate* isolate,
                                                      const char* source) {
   v8::Local<v8::String> source_string =
-      v8::String::NewFromUtf8(isolate, source, v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8(isolate, source).ToLocalChecked();
   v8::Local<v8::Context> context = isolate->GetCurrentContext();
   v8::Local<v8::Script> script =
       v8::Script::Compile(context, source_string).ToLocalChecked();
@@ -735,4 +732,65 @@ class TestPlatform : public v8::Platform {
   DISALLOW_COPY_AND_ASSIGN(TestPlatform);
 };
 
+#if defined(USE_SIMULATOR)
+class SimulatorHelper {
+ public:
+  inline bool Init(v8::Isolate* isolate) {
+    simulator_ = reinterpret_cast<v8::internal::Isolate*>(isolate)
+                     ->thread_local_top()
+                     ->simulator_;
+    // Check if there is active simulator.
+    return simulator_ != nullptr;
+  }
+
+  inline void FillRegisters(v8::RegisterState* state) {
+#if V8_TARGET_ARCH_ARM
+    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
+    state->sp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::sp));
+    state->fp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::r11));
+    state->lr = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::lr));
+#elif V8_TARGET_ARCH_ARM64
+    if (simulator_->sp() == 0 || simulator_->fp() == 0) {
+      // It's possible that the simulator is interrupted while it is updating
+      // the sp or fp register. ARM64 simulator does this in two steps:
+      // first setting it to zero and then setting it to a new value.
+      // Bailout if sp/fp doesn't contain the new value.
+      return;
+    }
+    state->pc = reinterpret_cast<void*>(simulator_->pc());
+    state->sp = reinterpret_cast<void*>(simulator_->sp());
+    state->fp = reinterpret_cast<void*>(simulator_->fp());
+    state->lr = reinterpret_cast<void*>(simulator_->lr());
+#elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
+    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
+    state->sp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::sp));
+    state->fp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::fp));
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
+    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
+    state->sp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::sp));
+    state->fp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::fp));
+    state->lr = reinterpret_cast<void*>(simulator_->get_lr());
+#elif V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
+    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
+    state->sp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::sp));
+    state->fp = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::fp));
+    state->lr = reinterpret_cast<void*>(
+        simulator_->get_register(v8::internal::Simulator::ra));
+#endif
+  }
+
+ private:
+  v8::internal::Simulator* simulator_;
+};
+#endif  // USE_SIMULATOR
+
 #endif  // ifndef CCTEST_H_
diff --git a/deps/v8/test/cctest/cctest.status b/deps/v8/test/cctest/cctest.status
index 06583f6bd5..444ec9d8ec 100644
--- a/deps/v8/test/cctest/cctest.status
+++ b/deps/v8/test/cctest/cctest.status
@@ -140,8 +140,6 @@
 
 ##############################################################################
 ['arch == arm64', {
-  'test-api/Bug618': [PASS],
-
   # BUG(v8:3385).
   'test-serialize/StartupSerializerOnceRunScript': [PASS, FAIL],
   'test-serialize/StartupSerializerTwiceRunScript': [PASS, FAIL],
@@ -178,6 +176,12 @@
 }],  # variant == nooptimization and (arch == arm or arch == arm64) and simulator_run
 
 ##############################################################################
+['variant == no_lfa', {
+  # https://crbug.com/v8/10219
+  'test-compiler/DecideToPretenureDuringCompilation': [SKIP],
+}],  # variant == no_lfa
+
+##############################################################################
 ['asan == True', {
   # Skip tests not suitable for ASAN.
   'test-assembler-x64/AssemblerX64XchglOperations': [SKIP],
@@ -190,6 +194,10 @@
 ['msan == True', {
   # ICU upstream issues.
   'test-strings/CountBreakIterator': [SKIP],
+
+  # BUG(v8:10244): MSAN finding uninitialized bytes during memcmp
+  'test-code-stub-assembler/SmallOrderedHashSetAllocate': [SKIP],
+  'test-code-stub-assembler/SmallOrderedHashMapAllocate': [SKIP],
 }],  # 'msan == True'
 
 ##############################################################################
@@ -207,8 +215,8 @@
 
 ##############################################################################
 ['byteorder == big', {
-  # Skip WASM atomic tests on big-endian machines.
-  # There is no support to emulate atomic WASM operations on big-endian
+  # Skip Wasm atomic tests on big-endian machines.
+  # There is no support to emulate atomic Wasm operations on big-endian
   # platforms, since this would require bit swapping as a part of atomic
   # operations.
   'test-run-wasm-atomics/*': [SKIP],
@@ -455,7 +463,7 @@
   'test-api-wasm/WasmStreaming*': [SKIP],
   'test-backing-store/Run_WasmModule_Buffer_Externalized_Regression_UseAfterFree': [SKIP],
   'test-c-wasm-entry/*': [SKIP],
-  'test-compilation-cache/TestAsyncCache': [SKIP],
+  'test-compilation-cache/*': [SKIP],
   'test-jump-table-assembler/*': [SKIP],
   'test-grow-memory/*': [SKIP],
   'test-run-wasm-64/*': [SKIP],
@@ -474,6 +482,7 @@
   'test-streaming-compilation/*': [SKIP],
   'test-wasm-breakpoints/*': [SKIP],
   'test-wasm-codegen/*': [SKIP],
+  'test-wasm-debug-evaluate/*': [SKIP],
   'test-wasm-import-wrapper-cache/*': [SKIP],
   'test-wasm-interpreter-entry/*': [SKIP],
   'test-wasm-serialization/*': [SKIP],
@@ -484,6 +493,7 @@
 
   # Tests that generate code at runtime.
   'codegen-tester/*': [SKIP],
+  'serializer-tester/*': [SKIP],
   'test-accessor-assembler/*': [SKIP],
   'test-assembler-*': [SKIP],
   'test-basic-block-profiler/*': [SKIP],
@@ -492,7 +502,10 @@
   'test-code-generator/*': [SKIP],
   'test-code-pages/*': [SKIP],
   'test-code-stub-assembler/*': [SKIP],
+  'test-debug-helper/GetObjectProperties': [SKIP],
+  'test-disasm-x64/DisasmX64': [SKIP],
   'test-js-context-specialization/*': [SKIP],
+  'test-macro-assembler-x64/EmbeddedObj': [SKIP],
   'test-multiple-return/*': [SKIP],
   'test-regexp/MacroAssemblernativeAtStart': [SKIP],
   'test-regexp/MacroAssemblerNativeBackReferenceLATIN1': [SKIP],
@@ -523,8 +536,11 @@
   'test-run-tail-calls/*': [SKIP],
   'test-run-unwinding-info/*': [SKIP],
   'test-run-variables/*': [SKIP],
+  'test-serialize/*': [SKIP],
   'test-torque/*': [SKIP],
-  'test-macro-assembler-x64/EmbeddedObj': [SKIP],
+  'test-unwinder/PCIsInV8_InCodeOrEmbeddedRange': [SKIP],
+  'test-unwinder/PCIsInV8_LargeCodeObject': [SKIP],
+  'test-unwinder-code-pages/PCIsInV8_LargeCodeObject_CodePagesAPI': [SKIP],
 
   # Field representation tracking is disabled in jitless mode.
   'test-field-type-tracking/*': [SKIP],
@@ -600,11 +616,4 @@
   'test-cpu-profiler/DeoptUntrackedFunction': [SKIP],
 }],  # variant == turboprop
 
-##############################################################################
-['variant != future', {
-  # Wasm native module cache is temporarily disabled in non-future variant
-  # (https://crbug.com/1070199)
-  'test-compilation-cache/*': [SKIP]
-}],  # variant != future
-
 ]
diff --git a/deps/v8/test/cctest/compiler/test-code-assembler.cc b/deps/v8/test/cctest/compiler/test-code-assembler.cc
index e3db983488..9c9210f77e 100644
--- a/deps/v8/test/cctest/compiler/test-code-assembler.cc
+++ b/deps/v8/test/cctest/compiler/test-code-assembler.cc
@@ -34,12 +34,6 @@ Node* UndefinedConstant(CodeAssembler* m) {
   return m->LoadRoot(RootIndex::kUndefinedValue);
 }
 
-TNode<Smi> SmiFromInt32(CodeAssembler* m, Node* value) {
-  value = m->ChangeInt32ToIntPtr(value);
-  return m->BitcastWordToTaggedSigned(
-      m->WordShl(value, kSmiShiftSize + kSmiTagSize));
-}
-
 Node* LoadObjectField(CodeAssembler* m, Node* object, int offset,
                       MachineType type = MachineType::AnyTagged()) {
   return m->Load(type, object, m->IntPtrConstant(offset - kHeapObjectTag));
@@ -87,7 +81,7 @@ TEST(SimpleCallRuntime1Arg) {
   CodeAssembler m(asm_tester.state());
   TNode<Context> context =
       m.HeapConstant(Handle<Context>(isolate->native_context()));
-  Node* b = SmiTag(&m, m.Int32Constant(0));
+  TNode<Smi> b = SmiTag(&m, m.Int32Constant(0));
   m.Return(m.CallRuntime(Runtime::kIsSmi, context, b));
   FunctionTester ft(asm_tester.GenerateCode());
   CHECK(ft.CallChecked<Oddball>().is_identical_to(
@@ -100,7 +94,7 @@ TEST(SimpleTailCallRuntime1Arg) {
   CodeAssembler m(asm_tester.state());
   TNode<Context> context =
       m.HeapConstant(Handle<Context>(isolate->native_context()));
-  Node* b = SmiTag(&m, m.Int32Constant(0));
+  TNode<Smi> b = SmiTag(&m, m.Int32Constant(0));
   m.TailCallRuntime(Runtime::kIsSmi, context, b);
   FunctionTester ft(asm_tester.GenerateCode());
   CHECK(ft.CallChecked<Oddball>().is_identical_to(
@@ -113,8 +107,8 @@ TEST(SimpleCallRuntime2Arg) {
   CodeAssembler m(asm_tester.state());
   TNode<Context> context =
       m.HeapConstant(Handle<Context>(isolate->native_context()));
-  Node* a = SmiTag(&m, m.Int32Constant(2));
-  Node* b = SmiTag(&m, m.Int32Constant(4));
+  TNode<Smi> a = SmiTag(&m, m.Int32Constant(2));
+  TNode<Smi> b = SmiTag(&m, m.Int32Constant(4));
   m.Return(m.CallRuntime(Runtime::kAdd, context, a, b));
   FunctionTester ft(asm_tester.GenerateCode());
   CHECK_EQ(6, ft.CallChecked<Smi>()->value());
@@ -126,8 +120,8 @@ TEST(SimpleTailCallRuntime2Arg) {
   CodeAssembler m(asm_tester.state());
   TNode<Context> context =
       m.HeapConstant(Handle<Context>(isolate->native_context()));
-  Node* a = SmiTag(&m, m.Int32Constant(2));
-  Node* b = SmiTag(&m, m.Int32Constant(4));
+  TNode<Smi> a = SmiTag(&m, m.Int32Constant(2));
+  TNode<Smi> b = SmiTag(&m, m.Int32Constant(4));
   m.TailCallRuntime(Runtime::kAdd, context, a, b);
   FunctionTester ft(asm_tester.GenerateCode());
   CHECK_EQ(6, ft.CallChecked<Smi>()->value());
@@ -446,127 +440,6 @@ TEST(TestOutOfScopeVariable) {
   CHECK(!asm_tester.GenerateCode().is_null());
 }
 
-TEST(GotoIfException) {
-  Isolate* isolate(CcTest::InitIsolateOnce());
-
-  const int kNumParams = 1;
-  CodeAssemblerTester asm_tester(isolate, kNumParams);
-  CodeAssembler m(asm_tester.state());
-
-  TNode<Context> context =
-      m.HeapConstant(Handle<Context>(isolate->native_context()));
-  TNode<Symbol> to_string_tag =
-      m.HeapConstant(isolate->factory()->to_string_tag_symbol());
-  Variable exception(&m, MachineRepresentation::kTagged);
-
-  CodeAssemblerLabel exception_handler(&m);
-  Callable to_string = Builtins::CallableFor(isolate, Builtins::kToString);
-  TNode<Object> string = m.CallStub(to_string, context, to_string_tag);
-  m.GotoIfException(string, &exception_handler, &exception);
-  m.Return(string);
-
-  m.Bind(&exception_handler);
-  m.Return(m.UncheckedCast<Object>(exception.value()));
-
-  FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
-  Handle<Object> result = ft.Call().ToHandleChecked();
-
-  // Should be a TypeError.
-  CHECK(result->IsJSObject());
-
-  Handle<Object> constructor =
-      Object::GetPropertyOrElement(isolate, result,
-                                   isolate->factory()->constructor_string())
-          .ToHandleChecked();
-  CHECK(constructor->SameValue(*isolate->type_error_function()));
-}
-
-TEST(GotoIfExceptionMultiple) {
-  Isolate* isolate(CcTest::InitIsolateOnce());
-
-  const int kNumParams = 4;  // receiver, first, second, third
-  CodeAssemblerTester asm_tester(isolate, kNumParams);
-  CodeAssembler m(asm_tester.state());
-
-  TNode<Context> context =
-      m.HeapConstant(Handle<Context>(isolate->native_context()));
-  Node* first_value = m.Parameter(0);
-  Node* second_value = m.Parameter(1);
-  Node* third_value = m.Parameter(2);
-
-  CodeAssemblerLabel exception_handler1(&m);
-  CodeAssemblerLabel exception_handler2(&m);
-  CodeAssemblerLabel exception_handler3(&m);
-  Variable return_value(&m, MachineRepresentation::kWord32);
-  Variable error(&m, MachineRepresentation::kTagged);
-
-  return_value.Bind(m.Int32Constant(0));
-
-  // try { return ToString(param1) } catch (e) { ... }
-  Callable to_string = Builtins::CallableFor(isolate, Builtins::kToString);
-  TNode<Object> string = m.CallStub(to_string, context, first_value);
-  m.GotoIfException(string, &exception_handler1, &error);
-  m.Return(string);
-
-  // try { ToString(param2); return 7 } catch (e) { ... }
-  m.Bind(&exception_handler1);
-  return_value.Bind(m.Int32Constant(7));
-  error.Bind(UndefinedConstant(&m));
-  string = m.CallStub(to_string, context, second_value);
-  m.GotoIfException(string, &exception_handler2, &error);
-  m.Return(SmiFromInt32(&m, return_value.value()));
-
-  // try { ToString(param3); return 7 & ~2; } catch (e) { return e; }
-  m.Bind(&exception_handler2);
-  // Return returnValue & ~2
-  error.Bind(UndefinedConstant(&m));
-  string = m.CallStub(to_string, context, third_value);
-  m.GotoIfException(string, &exception_handler3, &error);
-  m.Return(SmiFromInt32(
-      &m, m.Word32And(return_value.value(),
-                      m.Word32Xor(m.Int32Constant(2), m.Int32Constant(-1)))));
-
-  m.Bind(&exception_handler3);
-  m.Return(m.UncheckedCast<Object>(error.value()));
-
-  FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
-
-  Handle<Object> result;
-  // First handler does not throw, returns result of first value.
-  result = ft.Call(isolate->factory()->undefined_value(),
-                   isolate->factory()->to_string_tag_symbol())
-               .ToHandleChecked();
-  CHECK(String::cast(*result).IsOneByteEqualTo(OneByteVector("undefined")));
-
-  // First handler returns a number.
-  result = ft.Call(isolate->factory()->to_string_tag_symbol(),
-                   isolate->factory()->undefined_value())
-               .ToHandleChecked();
-  CHECK_EQ(7, Smi::ToInt(*result));
-
-  // First handler throws, second handler returns a number.
-  result = ft.Call(isolate->factory()->to_string_tag_symbol(),
-                   isolate->factory()->to_primitive_symbol())
-               .ToHandleChecked();
-  CHECK_EQ(7 & ~2, Smi::ToInt(*result));
-
-  // First handler throws, second handler throws, third handler returns thrown
-  // value.
-  result = ft.Call(isolate->factory()->to_string_tag_symbol(),
-                   isolate->factory()->to_primitive_symbol(),
-                   isolate->factory()->unscopables_symbol())
-               .ToHandleChecked();
-
-  // Should be a TypeError.
-  CHECK(result->IsJSObject());
-
-  Handle<Object> constructor =
-      Object::GetPropertyOrElement(isolate, result,
-                                   isolate->factory()->constructor_string())
-          .ToHandleChecked();
-  CHECK(constructor->SameValue(*isolate->type_error_function()));
-}
-
 TEST(ExceptionHandler) {
   Isolate* isolate(CcTest::InitIsolateOnce());
   const int kNumParams = 0;
@@ -576,7 +449,7 @@ TEST(ExceptionHandler) {
   CodeAssembler::TVariable<Object> var(m.SmiConstant(0), &m);
   CodeAssemblerLabel exception(&m, {&var}, CodeAssemblerLabel::kDeferred);
   {
-    CodeAssemblerScopedExceptionHandler handler(&m, &exception, &var);
+    ScopedExceptionHandler handler(&m, &exception, &var);
     TNode<Context> context =
         m.HeapConstant(Handle<Context>(isolate->native_context()));
     m.CallRuntime(Runtime::kThrow, context, m.SmiConstant(2));
diff --git a/deps/v8/test/cctest/compiler/test-code-generator.cc b/deps/v8/test/cctest/compiler/test-code-generator.cc
index 3e66856189..16faf976b6 100644
--- a/deps/v8/test/cctest/compiler/test-code-generator.cc
+++ b/deps/v8/test/cctest/compiler/test-code-generator.cc
@@ -5,6 +5,7 @@
 #include "src/base/utils/random-number-generator.h"
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/code-stub-assembler.h"
+#include "src/codegen/macro-assembler-inl.h"
 #include "src/codegen/optimized-compilation-info.h"
 #include "src/compiler/backend/code-generator.h"
 #include "src/compiler/backend/instruction.h"
@@ -1002,6 +1003,8 @@ class CodeGeneratorTester {
         Builtins::kNoBuiltinId, kMaxUnoptimizedFrameHeight,
         kMaxPushedArgumentCount);
 
+    generator_->tasm()->CodeEntry();
+
     // Force a frame to be created.
     generator_->frame_access_state()->MarkHasFrame(true);
     generator_->AssembleConstructFrame();
@@ -1069,7 +1072,7 @@ class CodeGeneratorTester {
                                  CodeGeneratorTester::PushTypeFlag push_type) {
     generator_->AssembleTailCallBeforeGap(instr, first_unused_stack_slot);
 #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_S390) || \
-    defined(V8_TARGET_ARCH_PPC)
+    defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
     // Only folding register pushes is supported on ARM.
     bool supported = ((push_type & CodeGenerator::kRegisterPush) == push_type);
 #elif defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_IA32) || \
diff --git a/deps/v8/test/cctest/compiler/test-multiple-return.cc b/deps/v8/test/cctest/compiler/test-multiple-return.cc
index 156ea8074a..fe12950bba 100644
--- a/deps/v8/test/cctest/compiler/test-multiple-return.cc
+++ b/deps/v8/test/cctest/compiler/test-multiple-return.cc
@@ -34,11 +34,11 @@ CallDescriptor* CreateCallDescriptor(Zone* zone, int return_count,
   wasm::FunctionSig::Builder builder(zone, return_count, param_count);
 
   for (int i = 0; i < param_count; i++) {
-    builder.AddParam(wasm::ValueTypes::ValueTypeFor(type));
+    builder.AddParam(wasm::ValueType::For(type));
   }
 
   for (int i = 0; i < return_count; i++) {
-    builder.AddReturn(wasm::ValueTypes::ValueTypeFor(type));
+    builder.AddReturn(wasm::ValueType::For(type));
   }
   return compiler::GetWasmCallDescriptor(zone, builder.Build());
 }
diff --git a/deps/v8/test/cctest/compiler/test-run-jsobjects.cc b/deps/v8/test/cctest/compiler/test-run-jsobjects.cc
index 2ce6242e9e..724dc05ebb 100644
--- a/deps/v8/test/cctest/compiler/test-run-jsobjects.cc
+++ b/deps/v8/test/cctest/compiler/test-run-jsobjects.cc
@@ -14,8 +14,8 @@ namespace compiler {
 TEST(ArgumentsMapped) {
   FunctionTester T("(function(a) { return arguments; })");
 
-  Handle<Object> arguments;
-  T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandle(&arguments);
+  Handle<Object> arguments =
+      T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandleChecked();
   CHECK(arguments->IsJSObject() && !arguments->IsJSArray());
   CHECK(JSObject::cast(*arguments).HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
@@ -28,8 +28,8 @@ TEST(ArgumentsMapped) {
 TEST(ArgumentsUnmapped) {
   FunctionTester T("(function(a) { 'use strict'; return arguments; })");
 
-  Handle<Object> arguments;
-  T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandle(&arguments);
+  Handle<Object> arguments =
+      T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandleChecked();
   CHECK(arguments->IsJSObject() && !arguments->IsJSArray());
   CHECK(!JSObject::cast(*arguments).HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
@@ -42,8 +42,8 @@ TEST(ArgumentsUnmapped) {
 TEST(ArgumentsRest) {
   FunctionTester T("(function(a, ...args) { return args; })");
 
-  Handle<Object> arguments;
-  T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandle(&arguments);
+  Handle<Object> arguments =
+      T.Call(T.Val(19), T.Val(23), T.Val(42), T.Val(65)).ToHandleChecked();
   CHECK(arguments->IsJSObject() && arguments->IsJSArray());
   CHECK(!JSObject::cast(*arguments).HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
diff --git a/deps/v8/test/cctest/compiler/test-run-load-store.cc b/deps/v8/test/cctest/compiler/test-run-load-store.cc
index 6f52f339f3..2def65a79e 100644
--- a/deps/v8/test/cctest/compiler/test-run-load-store.cc
+++ b/deps/v8/test/cctest/compiler/test-run-load-store.cc
@@ -264,15 +264,17 @@ void RunLoadImmIndex(MachineType type, TestAlignment t) {
   for (int offset = -1; offset <= 200000; offset *= -5) {
     for (int i = 0; i < kNumElems; i++) {
       BufferedRawMachineAssemblerTester<CType> m;
-      void* base_pointer = ComputeOffset(&buffer[0], offset * sizeof(CType));
+      CType* base_pointer = reinterpret_cast<CType*>(
+          ComputeOffset(&buffer[0], offset * sizeof(CType)));
 #ifdef V8_COMPRESS_POINTERS
       if (type.IsTagged()) {
         // When pointer compression is enabled then we need to access only
         // the lower 32-bit of the tagged value while the buffer contains
         // full 64-bit values.
-        base_pointer = LSB(base_pointer, kTaggedSize);
+        base_pointer = reinterpret_cast<CType*>(LSB(base_pointer, kTaggedSize));
       }
 #endif
+
       Node* base = m.PointerConstant(base_pointer);
       Node* index = m.Int32Constant((offset + i) * sizeof(buffer[0]));
       if (t == TestAlignment::kAligned) {
@@ -300,15 +302,21 @@ void RunLoadStore(MachineType type, TestAlignment t) {
   MemCopy(&zap_value, &zap_data, sizeof(CType));
   InitBuffer(in_buffer, kNumElems, type);
 
+#ifdef V8_TARGET_BIG_ENDIAN
+  int offset = sizeof(CType) - ElementSizeInBytes(type.representation());
+#else
+  int offset = 0;
+#endif
+
   for (int32_t x = 0; x < kNumElems; x++) {
     int32_t y = kNumElems - x - 1;
 
     RawMachineAssemblerTester<int32_t> m;
     int32_t OK = 0x29000 + x;
     Node* in_base = m.PointerConstant(in_buffer);
-    Node* in_index = m.IntPtrConstant(x * sizeof(CType));
+    Node* in_index = m.IntPtrConstant(x * sizeof(CType) + offset);
     Node* out_base = m.PointerConstant(out_buffer);
-    Node* out_index = m.IntPtrConstant(y * sizeof(CType));
+    Node* out_index = m.IntPtrConstant(y * sizeof(CType) + offset);
     if (t == TestAlignment::kAligned) {
       Node* load = m.Load(type, in_base, in_index);
       m.Store(type.representation(), out_base, out_index, load,
diff --git a/deps/v8/test/cctest/heap/heap-utils.cc b/deps/v8/test/cctest/heap/heap-utils.cc
index 30ebfd0502..15f9c2d89f 100644
--- a/deps/v8/test/cctest/heap/heap-utils.cc
+++ b/deps/v8/test/cctest/heap/heap-utils.cc
@@ -173,8 +173,8 @@ void SimulateIncrementalMarking(i::Heap* heap, bool force_completion) {
   if (!force_completion) return;
 
   while (!marking->IsComplete()) {
-    marking->V8Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    i::StepOrigin::kV8);
+    marking->Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  i::StepOrigin::kV8);
     if (marking->IsReadyToOverApproximateWeakClosure()) {
       marking->FinalizeIncrementally();
     }
diff --git a/deps/v8/test/cctest/heap/test-alloc.cc b/deps/v8/test/cctest/heap/test-alloc.cc
index 684bda4411..d92375d362 100644
--- a/deps/v8/test/cctest/heap/test-alloc.cc
+++ b/deps/v8/test/cctest/heap/test-alloc.cc
@@ -46,8 +46,8 @@ Handle<Object> HeapTester::TestAllocateAfterFailures() {
   // we wrap the allocator function in an AlwaysAllocateScope.  Test that
   // all allocations succeed immediately without any retry.
   CcTest::CollectAllAvailableGarbage();
-  AlwaysAllocateScope scope(CcTest::i_isolate());
   Heap* heap = CcTest::heap();
+  AlwaysAllocateScopeForTesting scope(heap);
   int size = FixedArray::SizeFor(100);
   // Young generation.
   HeapObject obj =
@@ -159,17 +159,13 @@ TEST(StressJS) {
 
   // Add the Foo constructor the global object.
   CHECK(env->Global()
-            ->Set(env, v8::String::NewFromUtf8(CcTest::isolate(), "Foo",
-                                               v8::NewStringType::kNormal)
-                           .ToLocalChecked(),
+            ->Set(env, v8::String::NewFromUtf8Literal(CcTest::isolate(), "Foo"),
                   v8::Utils::CallableToLocal(function))
             .FromJust());
   // Call the accessor through JavaScript.
   v8::Local<v8::Value> result =
-      v8::Script::Compile(
-          env, v8::String::NewFromUtf8(CcTest::isolate(), "(new Foo).get",
-                                       v8::NewStringType::kNormal)
-                   .ToLocalChecked())
+      v8::Script::Compile(env, v8::String::NewFromUtf8Literal(CcTest::isolate(),
+                                                              "(new Foo).get"))
           .ToLocalChecked()
           ->Run(env)
           .ToLocalChecked();
diff --git a/deps/v8/test/cctest/heap/test-array-buffer-tracker.cc b/deps/v8/test/cctest/heap/test-array-buffer-tracker.cc
index 82cc6c84f3..56730e7b76 100644
--- a/deps/v8/test/cctest/heap/test-array-buffer-tracker.cc
+++ b/deps/v8/test/cctest/heap/test-array-buffer-tracker.cc
@@ -42,6 +42,11 @@ bool IsTracked(i::Heap* heap, i::ArrayBufferExtension* extension) {
   return in_young || in_old;
 }
 
+bool IsTracked(i::Heap* heap, i::JSArrayBuffer buffer) {
+  return V8_ARRAY_BUFFER_EXTENSION_BOOL ? IsTracked(heap, buffer.extension())
+                                        : IsTracked(buffer);
+}
+
 }  // namespace
 
 namespace v8 {
@@ -504,6 +509,7 @@ TEST(ArrayBuffer_ExternalBackingStoreSizeIncreases) {
 }
 
 TEST(ArrayBuffer_ExternalBackingStoreSizeDecreases) {
+  FLAG_concurrent_array_buffer_sweeping = false;
   CcTest::InitializeVM();
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -525,9 +531,10 @@ TEST(ArrayBuffer_ExternalBackingStoreSizeDecreases) {
 }
 
 TEST(ArrayBuffer_ExternalBackingStoreSizeIncreasesMarkCompact) {
-  if (FLAG_never_compact || V8_ARRAY_BUFFER_EXTENSION_BOOL) return;
+  if (FLAG_never_compact) return;
   ManualGCScope manual_gc_scope;
   FLAG_manual_evacuation_candidates_selection = true;
+  FLAG_concurrent_array_buffer_sweeping = false;
   CcTest::InitializeVM();
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -544,13 +551,13 @@ TEST(ArrayBuffer_ExternalBackingStoreSizeIncreasesMarkCompact) {
     Local<v8::ArrayBuffer> ab1 =
         v8::ArrayBuffer::New(isolate, kArraybufferSize);
     Handle<JSArrayBuffer> buf1 = v8::Utils::OpenHandle(*ab1);
-    CHECK(IsTracked(*buf1));
+    CHECK(IsTracked(heap, *buf1));
     heap::GcAndSweep(heap, NEW_SPACE);
     heap::GcAndSweep(heap, NEW_SPACE);
 
     Page* page_before_gc = Page::FromHeapObject(*buf1);
     heap::ForceEvacuationCandidate(page_before_gc);
-    CHECK(IsTracked(*buf1));
+    CHECK(IsTracked(heap, *buf1));
 
     CcTest::CollectAllGarbage();
 
diff --git a/deps/v8/test/cctest/heap/test-external-string-tracker.cc b/deps/v8/test/cctest/heap/test-external-string-tracker.cc
index 7eb03e10e2..d6cffd43ca 100644
--- a/deps/v8/test/cctest/heap/test-external-string-tracker.cc
+++ b/deps/v8/test/cctest/heap/test-external-string-tracker.cc
@@ -147,8 +147,7 @@ TEST(ExternalString_ExternalBackingStoreSizeIncreasesAfterExternalization) {
 
     // Allocate normal string in the new gen.
     v8::Local<v8::String> str =
-        v8::String::NewFromUtf8(isolate, TEST_STR, v8::NewStringType::kNormal)
-            .ToLocalChecked();
+        v8::String::NewFromUtf8Literal(isolate, TEST_STR);
 
     CHECK_EQ(0, heap->new_space()->ExternalBackingStoreBytes(type) -
                     new_backing_store_before);
@@ -199,8 +198,7 @@ TEST(ExternalString_PromotedThinString) {
     // New external string in the young space. This string has the same content
     // as the previous one (that was already internalized).
     v8::Local<v8::String> string2 =
-        v8::String::NewFromUtf8(isolate, TEST_STR, v8::NewStringType::kNormal)
-            .ToLocalChecked();
+        v8::String::NewFromUtf8Literal(isolate, TEST_STR);
     bool success =
         string2->MakeExternal(new TestOneByteResource(i::StrDup(TEST_STR)));
     CHECK(success);
diff --git a/deps/v8/test/cctest/heap/test-heap.cc b/deps/v8/test/cctest/heap/test-heap.cc
index 5eaa28404e..d181f764f8 100644
--- a/deps/v8/test/cctest/heap/test-heap.cc
+++ b/deps/v8/test/cctest/heap/test-heap.cc
@@ -1576,7 +1576,7 @@ HEAP_TEST(TestSizeOfObjects) {
     // Allocate objects on several different old-space pages so that
     // concurrent sweeper threads will be busy sweeping the old space on
     // subsequent GC runs.
-    AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     int filler_size = static_cast<int>(FixedArray::SizeFor(8192));
     for (int i = 1; i <= 100; i++) {
       isolate->factory()->NewFixedArray(8192, AllocationType::kOld);
@@ -2175,8 +2175,8 @@ TEST(InstanceOfStubWriteBarrier) {
   while (!marking_state->IsBlack(f->code()) && !marking->IsStopped()) {
     // Discard any pending GC requests otherwise we will get GC when we enter
     // code below.
-    marking->V8Step(kStepSizeInMs, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kStepSizeInMs, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
   }
 
   CHECK(marking->IsMarking());
@@ -2189,7 +2189,6 @@ TEST(InstanceOfStubWriteBarrier) {
     g->Call(ctx, global, 0, nullptr).ToLocalChecked();
   }
 
-  CcTest::heap()->incremental_marking()->set_should_hurry(true);
   CcTest::CollectGarbage(OLD_SPACE);
 }
 
@@ -2269,8 +2268,8 @@ TEST(IdleNotificationFinishMarking) {
 
   const double kStepSizeInMs = 100;
   do {
-    marking->V8Step(kStepSizeInMs, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kStepSizeInMs, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
   } while (!CcTest::heap()
                 ->mark_compact_collector()
                 ->marking_worklists()
@@ -2299,7 +2298,7 @@ TEST(OptimizedAllocationAlwaysInNewSpace) {
   v8::HandleScope scope(CcTest::isolate());
   v8::Local<v8::Context> ctx = CcTest::isolate()->GetCurrentContext();
   heap::SimulateFullSpace(CcTest::heap()->new_space());
-  AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+  AlwaysAllocateScopeForTesting always_allocate(CcTest::heap());
   v8::Local<v8::Value> res = CompileRun(
       "function c(x) {"
       "  this.x = x;"
@@ -2823,7 +2822,7 @@ TEST(Regress1465) {
 
   CompileRun("function F() {}");
   {
-    AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+    AlwaysAllocateScopeForTesting always_allocate(CcTest::i_isolate()->heap());
     for (int i = 0; i < transitions_count; i++) {
       EmbeddedVector<char, 64> buffer;
       SNPrintF(buffer, "var o = new F; o.prop%d = %d;", i, i);
@@ -2861,7 +2860,7 @@ static i::Handle<JSObject> GetByName(const char* name) {
 
 #ifdef DEBUG
 static void AddTransitions(int transitions_count) {
-  AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+  AlwaysAllocateScopeForTesting always_allocate(CcTest::i_isolate()->heap());
   for (int i = 0; i < transitions_count; i++) {
     EmbeddedVector<char, 64> buffer;
     SNPrintF(buffer, "var o = new F; o.prop%d = %d;", i, i);
@@ -3011,7 +3010,7 @@ TEST(ReleaseOverReservedPages) {
   const int initial_page_count = old_space->CountTotalPages();
   const int overall_page_count = number_of_test_pages + initial_page_count;
   for (int i = 0; i < number_of_test_pages; i++) {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     heap::SimulateFullSpace(old_space);
     factory->NewFixedArray(1, AllocationType::kOld);
   }
@@ -3507,8 +3506,13 @@ TEST(DetailedErrorStackTraceBuiltinExit) {
     FixedArray parameters = stack_trace->Parameters(0);
 
     CHECK_EQ(parameters.length(), 2);
+#ifdef V8_REVERSE_JSARGS
+    CHECK(parameters.get(1).IsSmi());
+    CHECK_EQ(Smi::ToInt(parameters.get(1)), 9999);
+#else
     CHECK(parameters.get(0).IsSmi());
     CHECK_EQ(Smi::ToInt(parameters.get(0)), 9999);
+#endif
   });
 }
 
@@ -3588,7 +3592,7 @@ TEST(Regress169928) {
 
   // This should crash with a protection violation if we are running a build
   // with the bug.
-  AlwaysAllocateScope aa_scope(isolate);
+  AlwaysAllocateScopeForTesting aa_scope(isolate->heap());
   v8::Script::Compile(env.local(), mote_code_string)
       .ToLocalChecked()
       ->Run(env.local())
@@ -4858,10 +4862,8 @@ TEST(Regress357137) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope hscope(isolate);
   v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
-  global->Set(
-      v8::String::NewFromUtf8(isolate, "interrupt", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
-      v8::FunctionTemplate::New(isolate, RequestInterrupt));
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "interrupt"),
+              v8::FunctionTemplate::New(isolate, RequestInterrupt));
   v8::Local<v8::Context> context = v8::Context::New(isolate, nullptr, global);
   CHECK(!context.IsEmpty());
   v8::Context::Scope cscope(context);
@@ -4985,7 +4987,6 @@ TEST(Regress3631) {
       "for (var i = 0; i < 50; i++) {"
       "  weak_map.set(future_keys[i], i);"
       "}");
-  heap->incremental_marking()->set_should_hurry(true);
   CcTest::CollectGarbage(OLD_SPACE);
 }
 
@@ -5131,7 +5132,7 @@ void AllocateInSpace(Isolate* isolate, size_t bytes, AllocationSpace space) {
   CHECK(IsAligned(bytes, kTaggedSize));
   Factory* factory = isolate->factory();
   HandleScope scope(isolate);
-  AlwaysAllocateScope always_allocate(isolate);
+  AlwaysAllocateScopeForTesting always_allocate(isolate->heap());
   int elements =
       static_cast<int>((bytes - FixedArray::kHeaderSize) / kTaggedSize);
   Handle<FixedArray> array = factory->NewFixedArray(
@@ -5217,10 +5218,8 @@ TEST(MessageObjectLeak) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
   v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate);
-  global->Set(
-      v8::String::NewFromUtf8(isolate, "check", v8::NewStringType::kNormal)
-          .ToLocalChecked(),
-      v8::FunctionTemplate::New(isolate, CheckLeak));
+  global->Set(v8::String::NewFromUtf8Literal(isolate, "check"),
+              v8::FunctionTemplate::New(isolate, CheckLeak));
   v8::Local<v8::Context> context = v8::Context::New(isolate, nullptr, global);
   v8::Context::Scope cscope(context);
 
@@ -5421,7 +5420,7 @@ HEAP_TEST(Regress589413) {
 
   {
     // Ensure that incremental marking is not started unexpectedly.
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(isolate->heap());
 
     // Make sure the byte arrays will be promoted on the next GC.
     CcTest::CollectGarbage(NEW_SPACE);
@@ -5553,9 +5552,9 @@ TEST(Regress598319) {
   // only partially marked the large object.
   const double kSmallStepSizeInMs = 0.1;
   while (!marking->IsComplete()) {
-    marking->V8Step(kSmallStepSizeInMs,
-                    i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kSmallStepSizeInMs,
+                  i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
     if (page->IsFlagSet(Page::HAS_PROGRESS_BAR) && page->ProgressBar() > 0) {
       CHECK_NE(page->ProgressBar(), arr.get().Size());
       {
@@ -5573,9 +5572,9 @@ TEST(Regress598319) {
   // Finish marking with bigger steps to speed up test.
   const double kLargeStepSizeInMs = 1000;
   while (!marking->IsComplete()) {
-    marking->V8Step(kLargeStepSizeInMs,
-                    i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kLargeStepSizeInMs,
+                  i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
     if (marking->IsReadyToOverApproximateWeakClosure()) {
       marking->FinalizeIncrementally();
     }
@@ -5651,14 +5650,14 @@ TEST(Regress615489) {
   CHECK(marking->IsMarking());
   marking->StartBlackAllocationForTesting();
   {
-    AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     v8::HandleScope inner(CcTest::isolate());
     isolate->factory()->NewFixedArray(500, AllocationType::kOld)->Size();
   }
   const double kStepSizeInMs = 100;
   while (!marking->IsComplete()) {
-    marking->V8Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
     if (marking->IsReadyToOverApproximateWeakClosure()) {
       marking->FinalizeIncrementally();
     }
@@ -5711,8 +5710,7 @@ TEST(Regress631969) {
 
   // Allocate a cons string and promote it to a fresh page in the old space.
   heap::SimulateFullSpace(heap->old_space());
-  Handle<String> s3;
-  factory->NewConsString(s1, s2).ToHandle(&s3);
+  Handle<String> s3 = factory->NewConsString(s1, s2).ToHandleChecked();
   CcTest::CollectGarbage(NEW_SPACE);
   CcTest::CollectGarbage(NEW_SPACE);
 
@@ -5720,8 +5718,8 @@ TEST(Regress631969) {
   const double kStepSizeInMs = 100;
   IncrementalMarking* marking = heap->incremental_marking();
   while (!marking->IsComplete()) {
-    marking->V8Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
-                    StepOrigin::kV8);
+    marking->Step(kStepSizeInMs, i::IncrementalMarking::NO_GC_VIA_STACK_GUARD,
+                  StepOrigin::kV8);
     if (marking->IsReadyToOverApproximateWeakClosure()) {
       marking->FinalizeIncrementally();
     }
@@ -6391,13 +6389,13 @@ HEAP_TEST(RegressMissingWriteBarrierInAllocate) {
   heap::SimulateIncrementalMarking(heap, false);
   Handle<Map> map;
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     map = isolate->factory()->NewMap(HEAP_NUMBER_TYPE, HeapNumber::kSize);
   }
   heap->incremental_marking()->StartBlackAllocationForTesting();
   Handle<HeapObject> object;
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     object = handle(isolate->factory()->NewForTest(map, AllocationType::kOld),
                     isolate);
   }
@@ -6893,6 +6891,48 @@ TEST(Regress9701) {
   CHECK_EQ(mark_sweep_count_before, mark_sweep_count_after);
 }
 
+#if defined(V8_TARGET_ARCH_64_BIT) && !defined(V8_OS_ANDROID)
+UNINITIALIZED_TEST(HugeHeapLimit) {
+  uint64_t kMemoryGB = 16;
+  v8::Isolate::CreateParams create_params;
+  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
+  create_params.constraints.ConfigureDefaults(kMemoryGB * GB, kMemoryGB * GB);
+  v8::Isolate* isolate = v8::Isolate::New(create_params);
+  Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+#ifdef V8_COMPRESS_POINTERS
+  size_t kExpectedHeapLimit = Heap::AllocatorLimitOnMaxOldGenerationSize();
+#else
+  size_t kExpectedHeapLimit = size_t{4} * GB;
+#endif
+  CHECK_EQ(kExpectedHeapLimit, i_isolate->heap()->MaxOldGenerationSize());
+  CHECK_LT(size_t{3} * GB, i_isolate->heap()->MaxOldGenerationSize());
+  isolate->Dispose();
+}
+#endif
+
+UNINITIALIZED_TEST(HeapLimit) {
+  uint64_t kMemoryGB = 15;
+  v8::Isolate::CreateParams create_params;
+  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
+  create_params.constraints.ConfigureDefaults(kMemoryGB * GB, kMemoryGB * GB);
+  v8::Isolate* isolate = v8::Isolate::New(create_params);
+  Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+#if defined(V8_TARGET_ARCH_64_BIT) && !defined(V8_OS_ANDROID)
+  size_t kExpectedHeapLimit = size_t{2} * GB;
+#else
+  size_t kExpectedHeapLimit = size_t{1} * GB;
+#endif
+  CHECK_EQ(kExpectedHeapLimit, i_isolate->heap()->MaxOldGenerationSize());
+  isolate->Dispose();
+}
+
+TEST(NoCodeRangeInJitlessMode) {
+  if (!FLAG_jitless) return;
+  CcTest::InitializeVM();
+  CHECK(
+      CcTest::i_isolate()->heap()->memory_allocator()->code_range().is_empty());
+}
+
 }  // namespace heap
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/heap/test-invalidated-slots.cc b/deps/v8/test/cctest/heap/test-invalidated-slots.cc
index 861c48d69d..67e5c0d48e 100644
--- a/deps/v8/test/cctest/heap/test-invalidated-slots.cc
+++ b/deps/v8/test/cctest/heap/test-invalidated-slots.cc
@@ -24,12 +24,11 @@ Page* HeapTester::AllocateByteArraysOnPage(
   const int kLength = 256 - ByteArray::kHeaderSize;
   const int kSize = ByteArray::SizeFor(kLength);
   CHECK_EQ(kSize, 256);
-  Isolate* isolate = heap->isolate();
   PagedSpace* old_space = heap->old_space();
   Page* page;
   // Fill a page with byte arrays.
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     heap::SimulateFullSpace(old_space);
     ByteArray byte_array;
     CHECK(AllocateByteArrayForTest(heap, kLength, AllocationType::kOld)
@@ -181,7 +180,7 @@ HEAP_TEST(InvalidatedSlotsResetObjectRegression) {
 
 Handle<FixedArray> AllocateArrayOnFreshPage(Isolate* isolate,
                                             PagedSpace* old_space, int length) {
-  AlwaysAllocateScope always_allocate(isolate);
+  AlwaysAllocateScopeForTesting always_allocate(isolate->heap());
   heap::SimulateFullSpace(old_space);
   return isolate->factory()->NewFixedArray(length, AllocationType::kOld);
 }
@@ -242,7 +241,7 @@ HEAP_TEST(InvalidatedSlotsRightTrimLargeFixedArray) {
       AllocateArrayOnEvacuationCandidate(isolate, old_space, 1);
   Handle<FixedArray> trimmed;
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     trimmed = factory->NewFixedArray(
         kMaxRegularHeapObjectSize / kTaggedSize + 100, AllocationType::kOld);
     DCHECK(MemoryChunk::FromHeapObject(*trimmed)->InLargeObjectSpace());
@@ -319,7 +318,7 @@ HEAP_TEST(InvalidatedSlotsFastToSlow) {
   AllocateArrayOnFreshPage(isolate, old_space, 1);
   Handle<JSObject> obj;
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     Handle<JSFunction> function = factory->NewFunctionForTest(name);
     function->shared().set_expected_nof_properties(3);
     obj = factory->NewJSObject(function, AllocationType::kOld);
diff --git a/deps/v8/test/cctest/heap/test-spaces.cc b/deps/v8/test/cctest/heap/test-spaces.cc
index 56649dd1dd..eb91a5e671 100644
--- a/deps/v8/test/cctest/heap/test-spaces.cc
+++ b/deps/v8/test/cctest/heap/test-spaces.cc
@@ -350,7 +350,7 @@ TEST(SizeOfInitialHeap) {
 // snapshot.
 // In PPC the page size is 64K, causing more internal fragmentation
 // hence requiring a larger limit.
-#if V8_OS_LINUX && V8_HOST_ARCH_PPC
+#if V8_OS_LINUX && (V8_HOST_ARCH_PPC || V8_HOST_ARCH_PPC64)
   const size_t kMaxInitialSizePerSpace = 3 * MB;
 #else
   const size_t kMaxInitialSizePerSpace = 2 * MB;
@@ -568,7 +568,7 @@ HEAP_TEST(Regress777177) {
 
   {
     // Ensure a new linear allocation area on a fresh page.
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     heap::SimulateFullSpace(old_space);
     AllocationResult result = old_space->AllocateRaw(filler_size, kWordAligned);
     HeapObject obj = result.ToObjectChecked();
diff --git a/deps/v8/test/cctest/interpreter/bytecode-expectations-printer.cc b/deps/v8/test/cctest/interpreter/bytecode-expectations-printer.cc
index 6d2e697472..7be26694ad 100644
--- a/deps/v8/test/cctest/interpreter/bytecode-expectations-printer.cc
+++ b/deps/v8/test/cctest/interpreter/bytecode-expectations-printer.cc
@@ -51,8 +51,7 @@ const char* const BytecodeExpectationsPrinter::kIndent = "  ";
 
 v8::Local<v8::String> BytecodeExpectationsPrinter::V8StringFromUTF8(
     const char* data) const {
-  return v8::String::NewFromUtf8(isolate_, data, v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(isolate_, data).ToLocalChecked();
 }
 
 std::string BytecodeExpectationsPrinter::WrapCodeInFunction(
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
index 067979d20d..98d2c6c61f 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ArrayLiterals.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
   /*   50 S> */ B(Return),
 ]
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
@@ -60,9 +58,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(4),
   /*   61 S> */ B(Return),
 ]
@@ -78,9 +75,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 66
+bytecode array length: 65
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(4),
@@ -123,9 +119,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(0),
   /*   52 S> */ B(CreateArrayFromIterable),
@@ -143,9 +138,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 75
+bytecode array length: 74
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(0),
   /*   52 S> */ B(CreateArrayLiteral), U8(1), U8(1), U8(37),
@@ -190,9 +184,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(0),
   /*   52 S> */ B(CreateArrayFromIterable),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/AssignmentsInBinaryExpression.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/AssignmentsInBinaryExpression.golden
index 07d2ea75ef..826018e952 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/AssignmentsInBinaryExpression.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/AssignmentsInBinaryExpression.golden
@@ -12,9 +12,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   49 S> */ B(LdaSmi), I8(1),
@@ -42,9 +41,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(55),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(100),
@@ -65,9 +63,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(55),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(100),
@@ -95,9 +92,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 27
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(55),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(56),
@@ -125,9 +121,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(55),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(1),
@@ -158,9 +153,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(55),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(1),
@@ -190,9 +184,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 73
+bytecode array length: 72
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   50 S> */ B(LdaSmi), I8(20),
@@ -238,9 +231,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 43
+bytecode array length: 42
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(17),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncGenerators.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncGenerators.golden
index 8691944b20..8701e50592 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncGenerators.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncGenerators.golden
@@ -14,13 +14,12 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 148
+bytecode array length: 144
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   17 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
                 B(Mov), R(context), R(4),
@@ -35,9 +34,12 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
                 B(Mov), R(5), R(2),
-                B(Jump), U8(53),
-                B(Ldar), R(5),
-                B(Jump), U8(36),
+                B(Jump), U8(50),
+                B(LdaUndefined),
+                B(Star), R(2),
+                B(LdaSmi), I8(1),
+                B(Star), R(1),
+                B(Jump), U8(41),
                 B(Star), R(5),
                 B(CreateCatchContext), R(5), U8(3),
                 B(Star), R(4),
@@ -53,10 +55,6 @@ bytecodes: [
                 B(Star), R(2),
                 B(LdaSmi), I8(2),
                 B(Star), R(1),
-                B(Jump), U8(15),
-                B(LdaSmi), I8(-1),
-                B(Star), R(2),
-                B(Star), R(1),
                 B(Jump), U8(7),
                 B(Star), R(2),
                 B(LdaZero),
@@ -93,8 +91,8 @@ constant pool: [
   Smi [23],
 ]
 handlers: [
-  [20, 94, 102],
-  [23, 56, 60],
+  [19, 98, 98],
+  [22, 64, 64],
 ]
 
 ---
@@ -104,13 +102,12 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 193
+bytecode array length: 189
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   17 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
                 B(Mov), R(context), R(4),
@@ -125,7 +122,7 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
                 B(Mov), R(5), R(2),
-                B(Jump), U8(98),
+                B(Jump), U8(95),
   /*   22 S> */ B(LdaSmi), I8(42),
                 B(Star), R(6),
                 B(LdaFalse),
@@ -142,9 +139,12 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
                 B(Mov), R(5), R(2),
-                B(Jump), U8(53),
-                B(Ldar), R(5),
-                B(Jump), U8(36),
+                B(Jump), U8(50),
+                B(LdaUndefined),
+                B(Star), R(2),
+                B(LdaSmi), I8(1),
+                B(Star), R(1),
+                B(Jump), U8(41),
                 B(Star), R(5),
                 B(CreateCatchContext), R(5), U8(6),
                 B(Star), R(4),
@@ -160,10 +160,6 @@ bytecodes: [
                 B(Star), R(2),
                 B(LdaSmi), I8(2),
                 B(Star), R(1),
-                B(Jump), U8(15),
-                B(LdaSmi), I8(-1),
-                B(Star), R(2),
-                B(Star), R(1),
                 B(Jump), U8(7),
                 B(Star), R(2),
                 B(LdaZero),
@@ -203,8 +199,8 @@ constant pool: [
   Smi [23],
 ]
 handlers: [
-  [20, 139, 147],
-  [23, 101, 105],
+  [19, 143, 143],
+  [22, 109, 109],
 ]
 
 ---
@@ -214,13 +210,12 @@ snippet: "
 "
 frame size: 19
 parameter count: 1
-bytecode array length: 364
+bytecode array length: 361
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+  /*   17 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(6),
                 B(Mov), R(context), R(7),
@@ -254,13 +249,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(14), U8(1),
                 B(LdaNamedProperty), R(14), U8(6), U8(9),
-                B(JumpIfToBooleanTrue), U8(67),
+                B(JumpIfToBooleanTrue), U8(66),
                 B(LdaNamedProperty), R(14), U8(7), U8(11),
                 B(Star), R(14),
                 B(LdaFalse),
                 B(Star), R(10),
                 B(Mov), R(14), R(1),
-  /*   22 E> */ B(StackCheck),
   /*   31 S> */ B(Mov), R(1), R(3),
   /*   42 S> */ B(LdaFalse),
                 B(Star), R(17),
@@ -279,7 +273,7 @@ bytecodes: [
                 B(Mov), R(15), R(12),
                 B(Jump), U8(20),
                 B(Ldar), R(15),
-                B(JumpLoop), U8(84), I8(0),
+  /*   22 E> */ B(JumpLoop), U8(83), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(12),
                 B(Star), R(11),
@@ -325,8 +319,12 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(4),
                 B(Mov), R(12), R(5),
-                B(Jump), U8(51),
-                B(Jump), U8(36),
+                B(Jump), U8(50),
+                B(LdaUndefined),
+                B(Star), R(5),
+                B(LdaSmi), I8(1),
+                B(Star), R(4),
+                B(Jump), U8(41),
                 B(Star), R(8),
                 B(CreateCatchContext), R(8), U8(14),
                 B(Star), R(7),
@@ -342,10 +340,6 @@ bytecodes: [
                 B(Star), R(5),
                 B(LdaSmi), I8(2),
                 B(Star), R(4),
-                B(Jump), U8(15),
-                B(LdaSmi), I8(-1),
-                B(Star), R(5),
-                B(Star), R(4),
                 B(Jump), U8(7),
                 B(Star), R(5),
                 B(LdaZero),
@@ -374,7 +368,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [29],
-  Smi [142],
+  Smi [141],
   Smi [16],
   Smi [7],
   ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
@@ -388,16 +382,16 @@ constant pool: [
   Smi [6],
   Smi [9],
   SCOPE_INFO_TYPE,
-  Smi [269],
+  Smi [267],
   Smi [6],
   Smi [9],
   Smi [23],
 ]
 handlers: [
-  [20, 310, 318],
-  [23, 274, 276],
-  [87, 174, 182],
-  [206, 239, 241],
+  [19, 315, 315],
+  [22, 281, 281],
+  [86, 172, 180],
+  [204, 237, 239],
 ]
 
 ---
@@ -408,13 +402,12 @@ snippet: "
 "
 frame size: 17
 parameter count: 1
-bytecode array length: 467
+bytecode array length: 463
 bytecodes: [
-  /*   44 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(5),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   44 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
                 B(Mov), R(context), R(4),
@@ -477,7 +470,7 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
                 B(Mov), R(10), R(2),
-                B(Jump), U8(241),
+                B(Jump), U8(238),
                 B(LdaNamedProperty), R(7), U8(14), U8(20),
                 B(JumpIfUndefinedOrNull), U8(11),
                 B(Star), R(12),
@@ -545,9 +538,12 @@ bytecodes: [
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
                 B(Mov), R(7), R(2),
-                B(Jump), U8(53),
-                B(Ldar), R(7),
-                B(Jump), U8(36),
+                B(Jump), U8(50),
+                B(LdaUndefined),
+                B(Star), R(2),
+                B(LdaSmi), I8(1),
+                B(Star), R(1),
+                B(Jump), U8(41),
                 B(Star), R(5),
                 B(CreateCatchContext), R(5), U8(17),
                 B(Star), R(4),
@@ -563,10 +559,6 @@ bytecodes: [
                 B(Star), R(2),
                 B(LdaSmi), I8(2),
                 B(Star), R(1),
-                B(Jump), U8(15),
-                B(LdaSmi), I8(-1),
-                B(Star), R(2),
-                B(Star), R(1),
                 B(Jump), U8(7),
                 B(Star), R(2),
                 B(LdaZero),
@@ -612,13 +604,13 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["done"],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["value"],
   SCOPE_INFO_TYPE,
-  Smi [372],
+  Smi [369],
   Smi [6],
   Smi [9],
   Smi [23],
 ]
 handlers: [
-  [20, 413, 421],
-  [23, 375, 379],
+  [19, 417, 417],
+  [22, 383, 383],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncModules.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncModules.golden
index 6d88ba285a..94d285aa15 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncModules.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/AsyncModules.golden
@@ -12,162 +12,148 @@ top level await: yes
 snippet: "
   await 42;
 "
-frame size: 8
-parameter count: 2
-bytecode array length: 142
+frame size: 7
+parameter count: 1
+bytecode array length: 127
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
-                B(LdaConstant), U8(2),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(3), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   10 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
-                B(Mov), R(context), R(3),
+                B(Mov), R(context), R(2),
   /*    0 S> */ B(LdaSmi), I8(42),
-                B(Star), R(5),
-                B(Mov), R(0), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(4), U8(2),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(1),
-                B(ResumeGenerator), R(0), R(0), U8(4),
                 B(Star), R(4),
+                B(Mov), R(0), R(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(3), U8(2),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(1),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(Star), R(5),
+                B(Star), R(4),
                 B(LdaZero),
-                B(TestReferenceEqual), R(5),
+                B(TestReferenceEqual), R(4),
                 B(JumpIfTrue), U8(5),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
                 B(ReThrow),
                 B(LdaUndefined),
-                B(Star), R(5),
+                B(Star), R(4),
                 B(LdaTrue),
-                B(Star), R(6),
-                B(Mov), R(0), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
+                B(Star), R(5),
+                B(Mov), R(0), R(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(3), U8(3),
   /*   10 S> */ B(Return),
-                B(Star), R(4),
-                B(CreateCatchContext), R(4), U8(5),
                 B(Star), R(3),
+                B(CreateCatchContext), R(3), U8(4),
+                B(Star), R(2),
                 B(LdaTheHole),
                 B(SetPendingMessage),
-                B(Ldar), R(3),
-                B(PushContext), R(4),
+                B(Ldar), R(2),
+                B(PushContext), R(3),
                 B(LdaImmutableCurrentContextSlot), U8(2),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaTrue),
-                B(Star), R(7),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(5), U8(3),
+                B(Star), R(6),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(4), U8(3),
   /*   10 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  Smi [79],
-  SCOPE_INFO_TYPE,
+  Smi [21],
+  Smi [65],
   Smi [10],
   Smi [7],
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [64, 114, 114],
+  [49, 99, 99],
 ]
 
 ---
 snippet: "
   await import(\"foo\");
 "
-frame size: 8
-parameter count: 2
-bytecode array length: 152
+frame size: 7
+parameter count: 1
+bytecode array length: 137
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
-                B(LdaConstant), U8(2),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(3), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   21 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
-                B(Mov), R(context), R(3),
-  /*    0 S> */ B(LdaConstant), U8(5),
-                B(Star), R(5),
-                B(Mov), R(closure), R(4),
-                B(CallRuntime), U16(Runtime::kDynamicImportCall), R(4), U8(2),
-                B(Star), R(5),
-                B(Mov), R(0), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(4), U8(2),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(1),
-                B(ResumeGenerator), R(0), R(0), U8(4),
+                B(Mov), R(context), R(2),
+  /*    0 S> */ B(LdaConstant), U8(4),
+                B(Star), R(4),
+                B(Mov), R(closure), R(3),
+                B(CallRuntime), U16(Runtime::kDynamicImportCall), R(3), U8(2),
                 B(Star), R(4),
+                B(Mov), R(0), R(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(3), U8(2),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(1),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(Star), R(5),
+                B(Star), R(4),
                 B(LdaZero),
-                B(TestReferenceEqual), R(5),
+                B(TestReferenceEqual), R(4),
                 B(JumpIfTrue), U8(5),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
                 B(ReThrow),
                 B(LdaUndefined),
-                B(Star), R(5),
+                B(Star), R(4),
                 B(LdaTrue),
-                B(Star), R(6),
-                B(Mov), R(0), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
+                B(Star), R(5),
+                B(Mov), R(0), R(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(3), U8(3),
   /*   21 S> */ B(Return),
-                B(Star), R(4),
-                B(CreateCatchContext), R(4), U8(6),
                 B(Star), R(3),
+                B(CreateCatchContext), R(3), U8(5),
+                B(Star), R(2),
                 B(LdaTheHole),
                 B(SetPendingMessage),
-                B(Ldar), R(3),
-                B(PushContext), R(4),
+                B(Ldar), R(2),
+                B(PushContext), R(3),
                 B(LdaImmutableCurrentContextSlot), U8(2),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaTrue),
-                B(Star), R(7),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(5), U8(3),
+                B(Star), R(6),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(4), U8(3),
   /*   21 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  Smi [89],
-  SCOPE_INFO_TYPE,
+  Smi [21],
+  Smi [75],
   Smi [10],
   Smi [7],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["foo"],
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [64, 124, 124],
+  [49, 109, 109],
 ]
 
 ---
@@ -178,84 +164,77 @@ snippet: "
   }
   foo();
 "
-frame size: 9
-parameter count: 2
-bytecode array length: 153
+frame size: 8
+parameter count: 1
+bytecode array length: 138
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
-                B(LdaConstant), U8(2),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
-                B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
                 B(Star), R(0),
-                B(CreateClosure), U8(3), U8(0), U8(0),
+                B(CreateClosure), U8(2), U8(0), U8(0),
                 B(Star), R(1),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(4), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(SwitchOnSmiNoFeedback), U8(3), U8(2), I8(0),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   54 S> */ B(Return),
-                B(Mov), R(4), R(2),
+                B(Mov), R(3), R(2),
                 B(Ldar), R(2),
-                B(Mov), R(context), R(4),
+                B(Mov), R(context), R(3),
   /*    0 S> */ B(LdaSmi), I8(42),
-                B(Star), R(6),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(5), U8(2),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(5), U8(1),
-                B(ResumeGenerator), R(0), R(0), U8(5),
                 B(Star), R(5),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(4), U8(2),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(1),
+                B(ResumeGenerator), R(0), R(0), U8(4),
+                B(Star), R(4),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaZero),
-                B(TestReferenceEqual), R(6),
+                B(TestReferenceEqual), R(5),
                 B(JumpIfTrue), U8(5),
-                B(Ldar), R(5),
+                B(Ldar), R(4),
                 B(ReThrow),
   /*   47 S> */ B(CallUndefinedReceiver0), R(1), U8(0),
                 B(LdaUndefined),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaTrue),
-                B(Star), R(7),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(5), U8(3),
+                B(Star), R(6),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
   /*   54 S> */ B(Return),
-                B(Star), R(5),
-                B(CreateCatchContext), R(5), U8(6),
                 B(Star), R(4),
+                B(CreateCatchContext), R(4), U8(5),
+                B(Star), R(3),
                 B(LdaTheHole),
                 B(SetPendingMessage),
-                B(Ldar), R(4),
-                B(PushContext), R(5),
+                B(Ldar), R(3),
+                B(PushContext), R(4),
                 B(LdaImmutableCurrentContextSlot), U8(2),
-                B(Star), R(7),
+                B(Star), R(6),
                 B(LdaTrue),
-                B(Star), R(8),
-                B(Mov), R(0), R(6),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(6), U8(3),
+                B(Star), R(7),
+                B(Mov), R(0), R(5),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(5), U8(3),
   /*   54 S> */ B(Return),
 ]
 constant pool: [
-  Smi [43],
-  Smi [87],
-  SCOPE_INFO_TYPE,
+  Smi [29],
+  Smi [73],
   SHARED_FUNCTION_INFO_TYPE,
   Smi [10],
   Smi [7],
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [72, 125, 125],
+  [57, 110, 110],
 ]
 
 ---
@@ -263,87 +242,80 @@ snippet: "
   import * as foo from \"bar\";
   await import(\"goo\");
 "
-frame size: 9
-parameter count: 2
-bytecode array length: 164
+frame size: 8
+parameter count: 1
+bytecode array length: 149
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
-                B(LdaConstant), U8(2),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
-                B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
                 B(Star), R(0),
                 B(LdaZero),
-                B(Star), R(4),
-                B(CallRuntime), U16(Runtime::kGetModuleNamespace), R(4), U8(1),
+                B(Star), R(3),
+                B(CallRuntime), U16(Runtime::kGetModuleNamespace), R(3), U8(1),
                 B(Star), R(1),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(3), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   49 S> */ B(Return),
-                B(Mov), R(4), R(2),
+                B(Mov), R(3), R(2),
                 B(Ldar), R(2),
-                B(Mov), R(context), R(4),
-  /*   28 S> */ B(LdaConstant), U8(5),
-                B(Star), R(6),
-                B(Mov), R(closure), R(5),
-                B(CallRuntime), U16(Runtime::kDynamicImportCall), R(5), U8(2),
-                B(Star), R(6),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(5), U8(2),
-  /*   28 E> */ B(SuspendGenerator), R(0), R(0), U8(5), U8(1),
-                B(ResumeGenerator), R(0), R(0), U8(5),
+                B(Mov), R(context), R(3),
+  /*   28 S> */ B(LdaConstant), U8(4),
+                B(Star), R(5),
+                B(Mov), R(closure), R(4),
+                B(CallRuntime), U16(Runtime::kDynamicImportCall), R(4), U8(2),
                 B(Star), R(5),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(4), U8(2),
+  /*   28 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(1),
+                B(ResumeGenerator), R(0), R(0), U8(4),
+                B(Star), R(4),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaZero),
-                B(TestReferenceEqual), R(6),
+                B(TestReferenceEqual), R(5),
                 B(JumpIfTrue), U8(5),
-                B(Ldar), R(5),
+                B(Ldar), R(4),
                 B(ReThrow),
                 B(LdaUndefined),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(LdaTrue),
-                B(Star), R(7),
-                B(Mov), R(0), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(5), U8(3),
+                B(Star), R(6),
+                B(Mov), R(0), R(4),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
   /*   49 S> */ B(Return),
-                B(Star), R(5),
-                B(CreateCatchContext), R(5), U8(6),
                 B(Star), R(4),
+                B(CreateCatchContext), R(4), U8(5),
+                B(Star), R(3),
                 B(LdaTheHole),
                 B(SetPendingMessage),
-                B(Ldar), R(4),
-                B(PushContext), R(5),
+                B(Ldar), R(3),
+                B(PushContext), R(4),
                 B(LdaImmutableCurrentContextSlot), U8(2),
-                B(Star), R(7),
+                B(Star), R(6),
                 B(LdaTrue),
-                B(Star), R(8),
-                B(Mov), R(0), R(6),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(6), U8(3),
+                B(Star), R(7),
+                B(Mov), R(0), R(5),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionReject), R(5), U8(3),
   /*   49 S> */ B(Return),
 ]
 constant pool: [
-  Smi [47],
-  Smi [101],
-  SCOPE_INFO_TYPE,
+  Smi [33],
+  Smi [87],
   Smi [10],
   Smi [7],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["goo"],
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [76, 136, 136],
+  [61, 121, 121],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicBlockToBoolean.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicBlockToBoolean.golden
index 8677bcd99b..61e3ff9e4f 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicBlockToBoolean.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicBlockToBoolean.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanTrue), U8(8),
@@ -36,9 +35,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(11),
@@ -61,9 +59,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanTrue), U8(8),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicLoops.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicLoops.golden
index a5f97d46c4..4d53c3afa5 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicLoops.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/BasicLoops.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   97 S> */ B(Return),
@@ -35,9 +34,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   86 S> */ B(Return),
@@ -61,17 +59,15 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 54
+bytecode array length: 52
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
   /*   65 S> */ B(LdaSmi), I8(10),
   /*   65 E> */ B(TestLessThan), R(0), U8(0),
-                B(JumpIfFalse), U8(38),
-  /*   56 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(37),
   /*   75 S> */ B(Ldar), R(1),
   /*   81 E> */ B(MulSmi), I8(12), U8(1),
                 B(Star), R(1),
@@ -86,7 +82,7 @@ bytecodes: [
   /*  132 E> */ B(TestEqual), R(0), U8(4),
                 B(JumpIfFalse), U8(4),
   /*  138 S> */ B(Jump), U8(5),
-                B(JumpLoop), U8(40), I8(0),
+  /*   56 E> */ B(JumpLoop), U8(39), I8(0),
   /*  147 S> */ B(Ldar), R(1),
   /*  156 S> */ B(Return),
 ]
@@ -110,12 +106,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 62
+bytecode array length: 60
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   45 E> */ B(StackCheck),
   /*   62 S> */ B(LdaZero),
   /*   68 E> */ B(TestLessThan), R(0), U8(0),
                 B(JumpIfFalse), U8(4),
@@ -139,7 +133,7 @@ bytecodes: [
   /*  173 S> */ B(Ldar), R(0),
   /*  179 E> */ B(AddSmi), I8(1), U8(5),
                 B(Star), R(0),
-                B(JumpLoop), U8(52), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(51), I8(0),
   /*  186 S> */ B(Ldar), R(0),
   /*  195 S> */ B(Return),
 ]
@@ -163,28 +157,26 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 44
+bytecode array length: 43
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   45 E> */ B(StackCheck),
   /*   71 S> */ B(LdaSmi), I8(3),
   /*   71 E> */ B(TestLessThan), R(0), U8(0),
-                B(JumpIfFalse), U8(22),
-  /*   62 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(20),
   /*   82 S> */ B(LdaSmi), I8(2),
   /*   88 E> */ B(TestEqual), R(0), U8(1),
                 B(JumpIfFalse), U8(4),
-  /*   94 S> */ B(Jump), U8(12),
+  /*   94 S> */ B(Jump), U8(11),
   /*  105 S> */ B(Ldar), R(0),
   /*  111 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(24), I8(1),
+                B(Jump), U8(11),
   /*  122 S> */ B(Ldar), R(0),
   /*  128 E> */ B(AddSmi), I8(1), U8(3),
                 B(Star), R(0),
-  /*  135 S> */ B(Jump), U8(2),
+  /*  135 S> */ B(Jump), U8(5),
+  /*   45 E> */ B(JumpLoop), U8(34), I8(0),
   /*  144 S> */ B(Ldar), R(0),
   /*  153 S> */ B(Return),
 ]
@@ -205,23 +197,21 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 32
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
   /*   64 S> */ B(Ldar), R(0),
-                B(JumpIfToBooleanFalse), U8(20),
-  /*   57 E> */ B(StackCheck),
+                B(JumpIfToBooleanFalse), U8(19),
   /*   71 S> */ B(Ldar), R(1),
   /*   77 E> */ B(MulSmi), I8(12), U8(0),
                 B(Star), R(1),
   /*   85 S> */ B(Ldar), R(0),
   /*   91 E> */ B(SubSmi), I8(1), U8(1),
                 B(Star), R(0),
-                B(JumpLoop), U8(19), I8(0),
+  /*   57 E> */ B(JumpLoop), U8(18), I8(0),
   /*   98 S> */ B(Ldar), R(1),
   /*  107 S> */ B(Return),
 ]
@@ -243,14 +233,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 54
+bytecode array length: 52
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   56 E> */ B(StackCheck),
   /*   63 S> */ B(Ldar), R(1),
   /*   69 E> */ B(MulSmi), I8(10), U8(0),
                 B(Star), R(1),
@@ -268,7 +256,7 @@ bytecodes: [
   /*  144 S> */ B(LdaSmi), I8(10),
   /*  144 E> */ B(TestLessThan), R(0), U8(4),
                 B(JumpIfFalse), U8(5),
-                B(JumpLoop), U8(40), I8(0),
+  /*   56 E> */ B(JumpLoop), U8(39), I8(0),
   /*  151 S> */ B(Ldar), R(1),
   /*  160 S> */ B(Return),
 ]
@@ -289,14 +277,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 30
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   57 E> */ B(StackCheck),
   /*   64 S> */ B(Ldar), R(1),
   /*   70 E> */ B(MulSmi), I8(12), U8(0),
                 B(Star), R(1),
@@ -304,7 +290,7 @@ bytecodes: [
   /*   84 E> */ B(SubSmi), I8(1), U8(1),
                 B(Star), R(0),
   /*   98 S> */ B(JumpIfToBooleanFalse), U8(5),
-                B(JumpLoop), U8(17), I8(0),
+  /*   57 E> */ B(JumpLoop), U8(16), I8(0),
   /*  102 S> */ B(Ldar), R(1),
   /*  111 S> */ B(Return),
 ]
@@ -326,14 +312,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 42
+bytecode array length: 40
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   56 E> */ B(StackCheck),
   /*   69 S> */ B(MulSmi), I8(10), U8(0),
                 B(Star), R(1),
   /*   77 S> */ B(LdaSmi), I8(5),
@@ -368,14 +352,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 47
+bytecode array length: 45
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   56 E> */ B(StackCheck),
   /*   63 S> */ B(Ldar), R(1),
   /*   69 E> */ B(MulSmi), I8(10), U8(0),
                 B(Star), R(1),
@@ -390,7 +372,7 @@ bytecodes: [
   /*  117 E> */ B(TestEqual), R(0), U8(3),
                 B(JumpIfFalse), U8(4),
   /*  123 S> */ B(Jump), U8(2),
-                B(JumpLoop), U8(33), I8(0),
+  /*   56 E> */ B(JumpLoop), U8(32), I8(0),
   /*  149 S> */ B(Ldar), R(1),
   /*  158 S> */ B(Return),
 ]
@@ -410,12 +392,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 35
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   45 E> */ B(StackCheck),
   /*   58 S> */ B(LdaSmi), I8(1),
   /*   64 E> */ B(TestEqual), R(0), U8(0),
                 B(JumpIfFalse), U8(4),
@@ -427,7 +407,7 @@ bytecodes: [
   /*  103 S> */ B(Ldar), R(0),
   /*  109 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(26), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(25), I8(0),
                 B(LdaUndefined),
   /*  116 S> */ B(Return),
 ]
@@ -446,12 +426,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 35
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   47 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   34 E> */ B(StackCheck),
   /*   56 S> */ B(LdaSmi), I8(1),
   /*   62 E> */ B(TestEqual), R(0), U8(0),
                 B(JumpIfFalse), U8(4),
@@ -463,7 +441,7 @@ bytecodes: [
   /*  101 S> */ B(Ldar), R(0),
   /*  107 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(26), I8(0),
+  /*   34 E> */ B(JumpLoop), U8(25), I8(0),
                 B(LdaUndefined),
   /*  114 S> */ B(Return),
 ]
@@ -482,12 +460,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 35
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   45 E> */ B(StackCheck),
   /*   68 S> */ B(LdaSmi), I8(1),
   /*   74 E> */ B(TestEqual), R(0), U8(0),
                 B(JumpIfFalse), U8(4),
@@ -499,7 +475,7 @@ bytecodes: [
   /*   55 S> */ B(Ldar), R(0),
   /*   59 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(26), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(25), I8(0),
                 B(LdaUndefined),
   /*  113 S> */ B(Return),
 ]
@@ -517,12 +493,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 35
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   47 S> */ B(LdaZero),
                 B(Star), R(0),
-  /*   34 E> */ B(StackCheck),
   /*   66 S> */ B(LdaSmi), I8(1),
   /*   72 E> */ B(TestEqual), R(0), U8(0),
                 B(JumpIfFalse), U8(4),
@@ -534,7 +508,7 @@ bytecodes: [
   /*   53 S> */ B(Ldar), R(0),
   /*   57 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(26), I8(0),
+  /*   34 E> */ B(JumpLoop), U8(25), I8(0),
                 B(LdaUndefined),
   /*  111 S> */ B(Return),
 ]
@@ -553,17 +527,15 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 34
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   58 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   63 S> */ B(LdaSmi), I8(100),
   /*   63 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(22),
-  /*   45 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(21),
   /*   85 S> */ B(Ldar), R(0),
   /*   91 E> */ B(AddSmi), I8(1), U8(1),
                 B(Star), R(0),
@@ -571,7 +543,7 @@ bytecodes: [
   /*   72 S> */ B(Ldar), R(1),
   /*   76 E> */ B(AddSmi), I8(1), U8(2),
                 B(Star), R(1),
-                B(JumpLoop), U8(24), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(23), I8(0),
                 B(LdaUndefined),
   /*  110 S> */ B(Return),
 ]
@@ -590,23 +562,21 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 33
+bytecode array length: 31
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   58 S> */ B(LdaSmi), I8(10),
                 B(Star), R(1),
   /*   62 S> */ B(Ldar), R(1),
-                B(JumpIfToBooleanFalse), U8(19),
-  /*   45 E> */ B(StackCheck),
+                B(JumpIfToBooleanFalse), U8(18),
   /*   74 S> */ B(Ldar), R(0),
   /*   80 E> */ B(MulSmi), I8(12), U8(0),
                 B(Star), R(0),
   /*   67 S> */ B(Ldar), R(1),
                 B(Dec), U8(1),
                 B(Star), R(1),
-                B(JumpLoop), U8(18), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(17), I8(0),
   /*   88 S> */ B(Ldar), R(0),
   /*   97 S> */ B(Return),
 ]
@@ -625,9 +595,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   58 S> */ B(LdaZero),
@@ -651,14 +620,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 34
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   58 S> */ B(LdaZero),
                 B(Star), R(1),
-  /*   45 E> */ B(StackCheck),
   /*   76 S> */ B(Ldar), R(0),
   /*   82 E> */ B(AddSmi), I8(1), U8(0),
                 B(Star), R(0),
@@ -669,7 +636,7 @@ bytecodes: [
   /*   69 S> */ B(Ldar), R(1),
                 B(Inc), U8(2),
                 B(Star), R(1),
-                B(JumpLoop), U8(23), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(22), I8(0),
   /*  112 S> */ B(Ldar), R(0),
   /*  121 S> */ B(Return),
 ]
@@ -692,14 +659,12 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 50
+bytecode array length: 48
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   52 S> */ B(Ldar), R(0),
-                B(JumpIfToBooleanFalse), U8(42),
-  /*   45 E> */ B(StackCheck),
+                B(JumpIfToBooleanFalse), U8(41),
                 B(CreateBlockContext), U8(0),
                 B(PushContext), R(3),
                 B(LdaTheHole),
@@ -717,7 +682,7 @@ bytecodes: [
                 B(Inc), U8(0),
   /*  127 E> */ B(StaCurrentContextSlot), U8(2),
                 B(PopContext), R(3),
-                B(JumpLoop), U8(41), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(40), I8(0),
                 B(LdaUndefined),
   /*  137 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/BreakableBlocks.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/BreakableBlocks.golden
index 18814169b9..e37a3ca0cf 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/BreakableBlocks.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/BreakableBlocks.golden
@@ -17,9 +17,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   62 S> */ B(AddSmi), I8(1), U8(0),
@@ -48,23 +47,20 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 69
+bytecode array length: 66
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   71 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   76 S> */ B(LdaSmi), I8(10),
   /*   76 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(54),
-  /*   58 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(52),
   /*  106 S> */ B(LdaZero),
                 B(Star), R(2),
   /*  111 S> */ B(LdaSmi), I8(3),
   /*  111 E> */ B(TestLessThan), R(2), U8(1),
-                B(JumpIfFalse), U8(34),
-  /*   93 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(33),
   /*  129 S> */ B(Ldar), R(0),
                 B(Inc), U8(2),
                 B(Star), R(0),
@@ -78,11 +74,11 @@ bytecodes: [
   /*  118 S> */ B(Ldar), R(2),
                 B(Inc), U8(5),
                 B(Star), R(2),
-                B(JumpLoop), U8(36), I8(1),
+  /*   93 E> */ B(JumpLoop), U8(35), I8(1),
   /*   84 S> */ B(Ldar), R(1),
                 B(Inc), U8(6),
                 B(Star), R(1),
-                B(JumpLoop), U8(56), I8(0),
+  /*   58 E> */ B(JumpLoop), U8(54), I8(0),
   /*  188 S> */ B(Ldar), R(0),
   /*  199 S> */ B(Return),
 ]
@@ -101,10 +97,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -141,10 +136,9 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 53
+bytecode array length: 52
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallAndSpread.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallAndSpread.golden
index 4d3d1eb7d6..293ad72957 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallAndSpread.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallAndSpread.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(1),
   /*   39 E> */ B(LdaNamedProperty), R(1), U8(1), U8(2),
@@ -38,9 +37,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 27
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(1),
   /*   39 E> */ B(LdaNamedProperty), R(1), U8(1), U8(2),
@@ -67,9 +65,8 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 101
+bytecode array length: 100
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaNamedProperty), R(0), U8(1), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallGlobal.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallGlobal.golden
index 5c5c0ac00c..2dfa6dc4c0 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallGlobal.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallGlobal.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   27 E> */ B(StackCheck),
   /*   32 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
   /*   39 E> */ B(CallUndefinedReceiver0), R(0), U8(2),
@@ -36,9 +35,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*   34 E> */ B(StackCheck),
   /*   39 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallLookupSlot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallLookupSlot.golden
index 4b48871fd2..1e5e0a2c8e 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallLookupSlot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallLookupSlot.golden
@@ -11,10 +11,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 75
+bytecode array length: 74
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallNew.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallNew.golden
index 4e7e6d3190..8674673d3d 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallNew.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallNew.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   45 E> */ B(StackCheck),
   /*   50 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
   /*   57 E> */ B(Construct), R(0), R(0), U8(0), U8(2),
@@ -36,9 +35,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   58 E> */ B(StackCheck),
   /*   63 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaSmi), I8(3),
@@ -66,9 +64,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
-  /*  100 E> */ B(StackCheck),
   /*  105 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaSmi), I8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallRuntime.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallRuntime.golden
index 761436decb..32a9a902ae 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CallRuntime.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CallRuntime.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(CallRuntime), U16(Runtime::kTheHole), R(0), U8(0),
                 B(LdaUndefined),
   /*   26 S> */ B(Return),
@@ -32,9 +31,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(CallRuntime), U16(Runtime::kIsArray), R(arg0), U8(1),
   /*   34 S> */ B(Return),
 ]
@@ -50,9 +48,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
                 B(LdaSmi), I8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassAndSuperClass.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassAndSuperClass.golden
index 7021630123..b4425f57fe 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassAndSuperClass.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassAndSuperClass.golden
@@ -22,9 +22,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 33
 bytecodes: [
-  /*   99 E> */ B(StackCheck),
                 B(Mov), R(closure), R(0),
   /*  104 S> */ B(LdaConstant), U8(0),
   /*  111 E> */ B(LdaKeyedProperty), R(closure), U8(1),
@@ -62,9 +61,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 47
+bytecode array length: 46
 bytecodes: [
-  /*  125 E> */ B(StackCheck),
                 B(Mov), R(closure), R(0),
   /*  130 S> */ B(LdaConstant), U8(0),
   /*  130 E> */ B(LdaKeyedProperty), R(closure), U8(0),
@@ -106,9 +104,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 40
+bytecode array length: 39
 bytecodes: [
-  /*  113 E> */ B(StackCheck),
                 B(Mov), R(closure), R(1),
   /*  118 S> */ B(Ldar), R(1),
                 B(GetSuperConstructor), R(3),
@@ -149,9 +146,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*  112 E> */ B(StackCheck),
                 B(Mov), R(closure), R(1),
   /*  117 S> */ B(Ldar), R(1),
                 B(GetSuperConstructor), R(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassDeclarations.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassDeclarations.golden
index d785701c0d..b16056a344 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassDeclarations.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ClassDeclarations.golden
@@ -14,10 +14,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 41
+bytecode array length: 40
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -53,10 +52,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 41
+bytecode array length: 40
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -94,10 +92,9 @@ snippet: "
 "
 frame size: 11
 parameter count: 1
-bytecode array length: 84
+bytecode array length: 83
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(2),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(2),
                 B(PushContext), R(1),
   /*   43 S> */ B(LdaConstant), U8(1),
   /*   43 E> */ B(StaCurrentContextSlot), U8(2),
@@ -153,10 +150,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 49
+bytecode array length: 48
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
   /*   46 S> */ B(LdaZero),
   /*   46 E> */ B(StaCurrentContextSlot), U8(2),
@@ -193,9 +189,8 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 70
+bytecode array length: 69
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareNil.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareNil.golden
index d9413a1866..848c420967 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareNil.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareNil.golden
@@ -12,9 +12,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(TestNull),
@@ -32,9 +31,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaUndefined),
                 B(Star), R(0),
   /*   53 S> */ B(TestUndefined),
@@ -52,9 +50,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaUndefined),
                 B(Star), R(0),
   /*   53 S> */ B(TestUndefined),
@@ -73,9 +70,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(2),
                 B(Star), R(0),
   /*   45 S> */ B(TestUndetectable),
@@ -94,9 +90,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaUndefined),
                 B(Star), R(0),
   /*   53 S> */ B(TestUndetectable),
@@ -114,9 +109,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaUndefined),
                 B(Star), R(0),
   /*   53 S> */ B(JumpIfNotUndefined), U8(6),
@@ -137,9 +131,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(TestUndetectable),
@@ -161,9 +154,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfUndefined), U8(6),
@@ -184,9 +176,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfNotNull), U8(6),
@@ -211,9 +202,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfNotNull), U8(5),
@@ -236,9 +226,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(TestUndetectable),
@@ -263,20 +252,18 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaUndefined),
                 B(Star), R(0),
   /*   61 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   73 S> */ B(Ldar), R(0),
-                B(JumpIfUndefined), U8(12),
-  /*   64 E> */ B(StackCheck),
+                B(JumpIfUndefined), U8(11),
   /*   92 S> */ B(Ldar), R(1),
                 B(Inc), U8(0),
                 B(Star), R(1),
-                B(JumpLoop), U8(11), I8(0),
+  /*   64 E> */ B(JumpLoop), U8(10), I8(0),
                 B(LdaUndefined),
   /*   99 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareTypeOf.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareTypeOf.golden
index 41108b12c8..9349f993dc 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareTypeOf.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompareTypeOf.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(1),
                 B(TestTypeOf), U8(0),
   /*   64 S> */ B(Return),
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaConstant), U8(0),
                 B(TestTypeOf), U8(1),
   /*   68 S> */ B(Return),
@@ -48,9 +46,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaTrue),
                 B(TestTypeOf), U8(3),
   /*   67 S> */ B(Return),
@@ -66,9 +63,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaUndefined),
                 B(TestTypeOf), U8(1),
   /*   72 S> */ B(Return),
@@ -84,9 +80,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaFalse),
   /*   73 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
index b8e9ebdb04..a040decf23 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CompoundExpressions.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(AddSmi), I8(2), U8(0),
@@ -32,9 +31,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(DivSmi), I8(2), U8(0),
@@ -53,9 +51,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   54 S> */ B(LdaNamedProperty), R(0), U8(1), U8(1),
@@ -77,9 +74,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   52 S> */ B(LdaSmi), I8(1),
@@ -102,10 +98,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   42 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Conditional.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Conditional.golden
index 2f82f7dda1..cd8f5de491 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Conditional.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Conditional.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(2),
   /*   51 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(3),
   /*   59 S> */ B(Return),
 ]
@@ -45,9 +43,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaZero),
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
@@ -70,9 +67,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(6),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariable.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariable.golden
index 0393f7407e..d5240602e1 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariable.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariable.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
                 B(LdaUndefined),
@@ -30,9 +29,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   57 S> */ B(Return),
@@ -48,9 +46,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 21
+bytecode array length: 20
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaTheHole),
                 B(Star), R(0),
   /*   44 S> */ B(LdaSmi), I8(20),
@@ -74,9 +71,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   48 S> */ B(LdaSmi), I8(20),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariableContextSlot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariableContextSlot.golden
index 3f07cbfd5f..8250d98b0f 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariableContextSlot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ConstVariableContextSlot.golden
@@ -11,10 +11,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -35,10 +34,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -59,10 +57,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -88,10 +85,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextParameters.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextParameters.golden
index c4fa209b33..d6a5199e52 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextParameters.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextParameters.golden
@@ -13,10 +13,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(2),
@@ -37,10 +36,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 2
-bytecode array length: 19
+bytecode array length: 18
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(2),
@@ -63,10 +61,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 5
-bytecode array length: 19
+bytecode array length: 18
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(2),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(2),
                 B(PushContext), R(0),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(3),
@@ -89,10 +86,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   26 S> */ B(Ldar), R(this),
   /*   26 E> */ B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextVariables.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextVariables.golden
index 88be31af43..73d710b2fa 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextVariables.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ContextVariables.golden
@@ -11,10 +11,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   41 S> */ B(CreateClosure), U8(1), U8(0), U8(2),
   /*   70 S> */ B(Return),
@@ -32,10 +31,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   42 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaCurrentContextSlot), U8(2),
@@ -55,10 +53,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 19
+bytecode array length: 18
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(2),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(2),
                 B(PushContext), R(0),
   /*   42 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaCurrentContextSlot), U8(2),
@@ -80,10 +77,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   41 S> */ B(CreateClosure), U8(1), U8(0), U8(2),
                 B(Star), R(1),
@@ -106,10 +102,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -393,10 +388,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 797
+bytecode array length: 796
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(Wide), B(CreateFunctionContext), U16(0), U16(256),
+  /*   30 E> */ B(Wide), B(CreateFunctionContext), U16(0), U16(256),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CountOperators.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CountOperators.golden
index 7a397e95af..0edc219769 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CountOperators.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CountOperators.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(Inc), U8(0),
@@ -31,9 +30,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(ToNumeric), U8(0),
@@ -54,9 +52,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(Dec), U8(0),
@@ -74,9 +71,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(ToNumeric), U8(0),
@@ -97,9 +93,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   54 S> */ B(LdaNamedProperty), R(0), U8(1), U8(1),
@@ -124,9 +119,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   54 S> */ B(LdaNamedProperty), R(0), U8(1), U8(1),
@@ -149,9 +143,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 31
+bytecode array length: 30
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   60 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
@@ -179,9 +172,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   60 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
@@ -207,10 +199,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
   /*   42 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaCurrentContextSlot), U8(2),
@@ -234,10 +225,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
   /*   42 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaCurrentContextSlot), U8(2),
@@ -264,9 +254,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   44 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   55 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateArguments.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateArguments.golden
index cc4909beff..3bb8f8ac2c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateArguments.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateArguments.golden
@@ -13,10 +13,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   10 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   32 S> */ B(Return),
 ]
@@ -32,10 +31,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   10 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   15 S> */ B(LdaZero),
   /*   31 E> */ B(LdaKeyedProperty), R(0), U8(0),
@@ -53,10 +51,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateUnmappedArguments),
+  /*   10 E> */ B(CreateUnmappedArguments),
                 B(Star), R(0),
   /*   46 S> */ B(Return),
 ]
@@ -72,10 +69,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 2
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(2),
@@ -98,10 +94,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 4
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(3),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(3),
                 B(PushContext), R(1),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(4),
@@ -126,10 +121,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 4
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateUnmappedArguments),
+  /*   10 E> */ B(CreateUnmappedArguments),
                 B(Star), R(0),
   /*   53 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateRestParameter.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateRestParameter.golden
index 14ce4e20a4..a0063ba5c4 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateRestParameter.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/CreateRestParameter.golden
@@ -13,10 +13,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*   10 E> */ B(CreateRestParameter),
                 B(Star), R(1),
                 B(Star), R(0),
   /*   42 S> */ B(Return),
@@ -33,10 +32,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 2
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*   10 E> */ B(CreateRestParameter),
                 B(Star), R(2),
                 B(Mov), R(arg0), R(0),
                 B(Mov), R(2), R(1),
@@ -55,10 +53,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 2
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*   10 E> */ B(CreateRestParameter),
                 B(Star), R(2),
                 B(Mov), R(arg0), R(0),
                 B(Mov), R(2), R(1),
@@ -78,10 +75,9 @@ snippet: "
 "
 frame size: 5
 parameter count: 2
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateUnmappedArguments),
+  /*   10 E> */ B(CreateUnmappedArguments),
                 B(Star), R(3),
                 B(CreateRestParameter),
                 B(Star), R(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeadCodeRemoval.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeadCodeRemoval.golden
index e164e29ab9..3d95c9c4f4 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeadCodeRemoval.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeadCodeRemoval.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaUndefined),
   /*   41 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   66 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
                 B(LdaUndefined),
@@ -47,9 +45,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(LdaSmi), I8(1),
   /*   55 S> */ B(Return),
 ]
@@ -64,9 +61,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(5),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeclareGlobals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeclareGlobals.golden
index fb36d01f98..27be2b47bd 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeclareGlobals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeclareGlobals.golden
@@ -12,13 +12,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
                 B(Mov), R(closure), R(2),
-                B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
+  /*    0 E> */ B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
   /*    8 S> */ B(LdaSmi), I8(1),
   /*    8 E> */ B(StaGlobal), U8(1), U8(0),
                 B(LdaUndefined),
@@ -37,13 +36,12 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(0),
                 B(Mov), R(closure), R(1),
-                B(CallRuntime), U16(Runtime::kDeclareGlobals), R(0), U8(2),
+  /*    0 E> */ B(CallRuntime), U16(Runtime::kDeclareGlobals), R(0), U8(2),
                 B(LdaUndefined),
   /*   16 S> */ B(Return),
 ]
@@ -60,13 +58,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
                 B(Mov), R(closure), R(2),
-                B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
+  /*    0 E> */ B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
   /*    8 S> */ B(LdaSmi), I8(1),
   /*    8 E> */ B(StaGlobal), U8(1), U8(0),
   /*   11 S> */ B(LdaSmi), I8(2),
@@ -88,13 +85,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
                 B(Mov), R(closure), R(2),
-                B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
+  /*    0 E> */ B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
   /*   16 S> */ B(LdaGlobal), U8(1), U8(0),
                 B(Star), R(1),
   /*   16 E> */ B(CallUndefinedReceiver0), R(1), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Delete.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Delete.golden
index 2d1ad15fe2..3af61115bd 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Delete.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Delete.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   56 S> */ B(LdaConstant), U8(1),
@@ -33,9 +32,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   56 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   70 S> */ B(LdaConstant), U8(1),
@@ -55,9 +53,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   56 S> */ B(LdaSmi), I8(2),
@@ -76,9 +73,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   46 S> */ B(LdaFalse),
@@ -98,10 +94,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
   /*   56 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
   /*   56 E> */ B(StaCurrentContextSlot), U8(2),
@@ -126,9 +121,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaTrue),
   /*   55 S> */ B(Return),
 ]
@@ -143,9 +137,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaTrue),
   /*   53 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeleteLookupSlotInEval.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeleteLookupSlotInEval.golden
index 587ed9b2ba..bff4c7a5da 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/DeleteLookupSlotInEval.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/DeleteLookupSlotInEval.golden
@@ -19,9 +19,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
                 B(CallRuntime), U16(Runtime::kDeleteLookupSlot), R(0), U8(1),
@@ -47,9 +46,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaFalse),
   /*   31 S> */ B(Return),
 ]
@@ -71,9 +69,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
                 B(CallRuntime), U16(Runtime::kDeleteLookupSlot), R(0), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/DestructuringAssignment.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/DestructuringAssignment.golden
index 8f23cff964..4bb89c6179 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/DestructuringAssignment.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/DestructuringAssignment.golden
@@ -12,9 +12,8 @@ snippet: "
 "
 frame size: 14
 parameter count: 1
-bytecode array length: 167
+bytecode array length: 166
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(1),
   /*   60 S> */ B(GetIterator), R(1), U8(1), U8(3),
@@ -99,8 +98,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [35, 77, 85],
-  [109, 142, 144],
+  [34, 76, 84],
+  [108, 141, 143],
 ]
 
 ---
@@ -110,9 +109,8 @@ snippet: "
 "
 frame size: 15
 parameter count: 1
-bytecode array length: 253
+bytecode array length: 252
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   48 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(2),
   /*   69 S> */ B(GetIterator), R(2), U8(1), U8(3),
@@ -231,8 +229,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [35, 163, 171],
-  [195, 228, 230],
+  [34, 162, 170],
+  [194, 227, 229],
 ]
 
 ---
@@ -242,9 +240,8 @@ snippet: "
 "
 frame size: 16
 parameter count: 1
-bytecode array length: 218
+bytecode array length: 217
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   40 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   51 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
@@ -351,8 +348,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [38, 128, 136],
-  [160, 193, 195],
+  [37, 127, 135],
+  [159, 192, 194],
 ]
 
 ---
@@ -362,9 +359,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(1),
   /*   54 S> */ B(LdaNamedProperty), R(1), U8(1), U8(1),
@@ -386,9 +382,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   40 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   48 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
@@ -413,9 +408,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 33
+bytecode array length: 32
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(1),
   /*   64 S> */ B(LdaConstant), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/DoDebugger.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/DoDebugger.golden
index 60e585f974..5bf3618bed 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/DoDebugger.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/DoDebugger.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(Debugger),
                 B(LdaUndefined),
   /*   44 S> */ B(Return),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Eval.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Eval.golden
index a8609261a7..bb695e0c35 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Eval.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Eval.golden
@@ -11,10 +11,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 59
+bytecode array length: 58
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForAwaitOf.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForAwaitOf.golden
index df9074524b..866694aa03 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForAwaitOf.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForAwaitOf.golden
@@ -16,13 +16,12 @@ snippet: "
 "
 frame size: 19
 parameter count: 1
-bytecode array length: 321
+bytecode array length: 319
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(4),
   /*   43 S> */ B(CreateArrayLiteral), U8(2), U8(0), U8(37),
@@ -65,16 +64,15 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(11), U8(1),
                 B(LdaNamedProperty), R(11), U8(6), U8(13),
-                B(JumpIfToBooleanTrue), U8(23),
+                B(JumpIfToBooleanTrue), U8(22),
                 B(LdaNamedProperty), R(11), U8(7), U8(15),
                 B(Star), R(11),
                 B(LdaFalse),
                 B(Star), R(7),
                 B(Mov), R(11), R(1),
-  /*   23 E> */ B(StackCheck),
   /*   38 S> */ B(Mov), R(1), R(3),
                 B(Ldar), R(11),
-                B(JumpLoop), U8(77), I8(0),
+  /*   23 E> */ B(JumpLoop), U8(76), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(9),
                 B(Star), R(8),
@@ -83,7 +81,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(8),
                 B(LdaTheHole),
-  /*   38 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(10),
                 B(Ldar), R(7),
                 B(JumpIfToBooleanTrue), U8(94),
@@ -155,7 +153,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [95],
-  Smi [224],
+  Smi [223],
   ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
   SYMBOL_TYPE,
   SYMBOL_TYPE,
@@ -167,9 +165,9 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [20, 293, 293],
-  [75, 155, 163],
-  [187, 256, 258],
+  [19, 291, 291],
+  [74, 153, 161],
+  [185, 254, 256],
 ]
 
 ---
@@ -181,13 +179,12 @@ snippet: "
 "
 frame size: 19
 parameter count: 1
-bytecode array length: 342
+bytecode array length: 340
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(4),
   /*   43 S> */ B(CreateArrayLiteral), U8(2), U8(0), U8(37),
@@ -230,13 +227,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(11), U8(1),
                 B(LdaNamedProperty), R(11), U8(6), U8(13),
-                B(JumpIfToBooleanTrue), U8(27),
+                B(JumpIfToBooleanTrue), U8(26),
                 B(LdaNamedProperty), R(11), U8(7), U8(15),
                 B(Star), R(11),
                 B(LdaFalse),
                 B(Star), R(7),
                 B(Mov), R(11), R(1),
-  /*   23 E> */ B(StackCheck),
   /*   38 S> */ B(Mov), R(1), R(3),
   /*   56 S> */ B(LdaSmi), I8(1),
                 B(Mov), R(11), R(9),
@@ -328,7 +324,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [95],
-  Smi [228],
+  Smi [227],
   ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
   SYMBOL_TYPE,
   SYMBOL_TYPE,
@@ -342,9 +338,9 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [20, 314, 314],
-  [75, 159, 167],
-  [191, 260, 262],
+  [19, 312, 312],
+  [74, 157, 165],
+  [189, 258, 260],
 ]
 
 ---
@@ -359,13 +355,12 @@ snippet: "
 "
 frame size: 19
 parameter count: 1
-bytecode array length: 337
+bytecode array length: 335
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(4),
   /*   43 S> */ B(CreateArrayLiteral), U8(2), U8(0), U8(37),
@@ -408,13 +403,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(11), U8(1),
                 B(LdaNamedProperty), R(11), U8(6), U8(13),
-                B(JumpIfToBooleanTrue), U8(39),
+                B(JumpIfToBooleanTrue), U8(38),
                 B(LdaNamedProperty), R(11), U8(7), U8(15),
                 B(Star), R(11),
                 B(LdaFalse),
                 B(Star), R(7),
                 B(Mov), R(11), R(1),
-  /*   23 E> */ B(StackCheck),
   /*   38 S> */ B(Mov), R(1), R(3),
   /*   63 S> */ B(LdaSmi), I8(10),
   /*   69 E> */ B(TestEqual), R(3), U8(17),
@@ -424,7 +418,7 @@ bytecodes: [
   /*   96 E> */ B(TestEqual), R(3), U8(18),
                 B(JumpIfFalse), U8(4),
   /*  103 S> */ B(Jump), U8(5),
-                B(JumpLoop), U8(93), I8(0),
+  /*   23 E> */ B(JumpLoop), U8(92), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(9),
                 B(Star), R(8),
@@ -505,7 +499,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [95],
-  Smi [240],
+  Smi [239],
   ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
   SYMBOL_TYPE,
   SYMBOL_TYPE,
@@ -517,9 +511,9 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [20, 309, 309],
-  [75, 171, 179],
-  [203, 272, 274],
+  [19, 307, 307],
+  [74, 169, 177],
+  [201, 270, 272],
 ]
 
 ---
@@ -532,12 +526,11 @@ snippet: "
 "
 frame size: 15
 parameter count: 1
-bytecode array length: 253
+bytecode array length: 251
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(Mov), R(closure), R(2),
                 B(Mov), R(this), R(3),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(2),
   /*   31 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
@@ -560,14 +553,13 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(9), U8(1),
                 B(LdaNamedProperty), R(9), U8(3), U8(10),
-                B(JumpIfToBooleanTrue), U8(33),
+                B(JumpIfToBooleanTrue), U8(32),
                 B(LdaNamedProperty), R(9), U8(4), U8(12),
                 B(Star), R(9),
                 B(LdaFalse),
                 B(Star), R(5),
                 B(Ldar), R(9),
   /*   58 E> */ B(StaNamedProperty), R(1), U8(5), U8(14),
-  /*   53 E> */ B(StackCheck),
   /*   87 S> */ B(LdaNamedProperty), R(1), U8(5), U8(16),
                 B(Star), R(7),
                 B(LdaSmi), I8(1),
@@ -658,8 +650,8 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [16, 225, 225],
-  [53, 106, 114],
-  [138, 171, 173],
+  [15, 223, 223],
+  [52, 104, 112],
+  [136, 169, 171],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForIn.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForIn.golden
index fe1defeefb..680e5ee5cf 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForIn.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForIn.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaUndefined),
   /*   57 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaUndefined),
   /*   62 S> */ B(Return),
 ]
@@ -45,9 +43,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaUndefined),
   /*   62 S> */ B(Return),
 ]
@@ -63,28 +60,26 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 44
+bytecode array length: 42
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
-  /*   68 S> */ B(JumpIfUndefinedOrNull), U8(37),
+  /*   68 S> */ B(JumpIfUndefinedOrNull), U8(36),
                 B(ToObject), R(3),
                 B(ForInEnumerate), R(3),
                 B(ForInPrepare), R(4), U8(0),
                 B(LdaZero),
                 B(Star), R(7),
   /*   63 S> */ B(ForInContinue), R(7), R(6),
-                B(JumpIfFalse), U8(22),
+                B(JumpIfFalse), U8(21),
                 B(ForInNext), R(3), R(7), R(4), U8(0),
-                B(JumpIfUndefined), U8(8),
+                B(JumpIfUndefined), U8(7),
                 B(Star), R(2),
-  /*   54 E> */ B(StackCheck),
   /*   63 S> */ B(Star), R(1),
   /*   82 S> */ B(Return),
                 B(ForInStep), R(7),
                 B(Star), R(7),
-                B(JumpLoop), U8(22), I8(0),
+  /*   54 E> */ B(JumpLoop), U8(21), I8(0),
                 B(LdaUndefined),
   /*   85 S> */ B(Return),
 ]
@@ -101,24 +96,22 @@ snippet: "
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 56
+bytecode array length: 54
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   59 S> */ B(CreateArrayLiteral), U8(0), U8(1), U8(37),
-                B(JumpIfUndefinedOrNull), U8(46),
+                B(JumpIfUndefinedOrNull), U8(45),
                 B(ToObject), R(3),
                 B(ForInEnumerate), R(3),
                 B(ForInPrepare), R(4), U8(0),
                 B(LdaZero),
                 B(Star), R(7),
   /*   54 S> */ B(ForInContinue), R(7), R(6),
-                B(JumpIfFalse), U8(31),
+                B(JumpIfFalse), U8(30),
                 B(ForInNext), R(3), R(7), R(4), U8(0),
-                B(JumpIfUndefined), U8(17),
+                B(JumpIfUndefined), U8(16),
                 B(Star), R(2),
-  /*   45 E> */ B(StackCheck),
   /*   54 S> */ B(Star), R(1),
   /*   70 S> */ B(Ldar), R(2),
   /*   75 E> */ B(Add), R(0), U8(2),
@@ -126,7 +119,7 @@ bytecodes: [
                 B(Star), R(0),
   /*   72 E> */ B(ForInStep), R(7),
                 B(Star), R(7),
-                B(JumpLoop), U8(31), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(30), I8(0),
                 B(LdaUndefined),
   /*   80 S> */ B(Return),
 ]
@@ -146,26 +139,24 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 83
+bytecode array length: 81
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   77 S> */ B(CreateArrayLiteral), U8(1), U8(2), U8(37),
-                B(JumpIfUndefinedOrNull), U8(70),
+                B(JumpIfUndefinedOrNull), U8(69),
                 B(ToObject), R(1),
                 B(ForInEnumerate), R(1),
                 B(ForInPrepare), R(2), U8(1),
                 B(LdaZero),
                 B(Star), R(5),
   /*   68 S> */ B(ForInContinue), R(5), R(4),
-                B(JumpIfFalse), U8(55),
+                B(JumpIfFalse), U8(54),
                 B(ForInNext), R(1), R(5), R(2), U8(1),
-                B(JumpIfUndefined), U8(41),
+                B(JumpIfUndefined), U8(40),
                 B(Star), R(6),
                 B(Ldar), R(6),
   /*   68 E> */ B(StaNamedProperty), R(0), U8(2), U8(3),
-  /*   62 E> */ B(StackCheck),
   /*  100 S> */ B(LdaNamedProperty), R(0), U8(2), U8(5),
                 B(Star), R(6),
                 B(LdaSmi), I8(10),
@@ -180,7 +171,7 @@ bytecodes: [
   /*  143 S> */ B(Jump), U8(9),
                 B(ForInStep), R(5),
                 B(Star), R(5),
-                B(JumpLoop), U8(55), I8(0),
+  /*   62 E> */ B(JumpLoop), U8(54), I8(0),
                 B(LdaUndefined),
   /*  152 S> */ B(Return),
 ]
@@ -199,34 +190,32 @@ snippet: "
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 62
+bytecode array length: 60
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(0),
   /*   72 S> */ B(CreateArrayLiteral), U8(1), U8(2), U8(37),
-                B(JumpIfUndefinedOrNull), U8(49),
+                B(JumpIfUndefinedOrNull), U8(48),
                 B(ToObject), R(1),
                 B(ForInEnumerate), R(1),
                 B(ForInPrepare), R(2), U8(1),
                 B(LdaZero),
                 B(Star), R(5),
   /*   65 S> */ B(ForInContinue), R(5), R(4),
-                B(JumpIfFalse), U8(34),
+                B(JumpIfFalse), U8(33),
                 B(ForInNext), R(1), R(5), R(2), U8(1),
-                B(JumpIfUndefined), U8(20),
+                B(JumpIfUndefined), U8(19),
                 B(Star), R(6),
                 B(LdaZero),
                 B(Star), R(8),
                 B(Ldar), R(6),
   /*   65 E> */ B(StaKeyedProperty), R(0), R(8), U8(3),
-  /*   59 E> */ B(StackCheck),
   /*   83 S> */ B(LdaSmi), I8(3),
   /*   91 E> */ B(LdaKeyedProperty), R(0), U8(5),
   /*   95 S> */ B(Return),
                 B(ForInStep), R(5),
                 B(Star), R(5),
-                B(JumpLoop), U8(34), I8(0),
+  /*   59 E> */ B(JumpLoop), U8(33), I8(0),
                 B(LdaUndefined),
   /*   98 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOf.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOf.golden
index 7be4c0bdea..681b4bc9f5 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOf.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOf.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 13
 parameter count: 1
-bytecode array length: 165
+bytecode array length: 163
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   48 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(4),
                 B(GetIterator), R(4), U8(1), U8(3),
@@ -32,16 +31,15 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(8), U8(1),
                 B(LdaNamedProperty), R(8), U8(2), U8(9),
-                B(JumpIfToBooleanTrue), U8(23),
+                B(JumpIfToBooleanTrue), U8(22),
                 B(LdaNamedProperty), R(8), U8(3), U8(11),
                 B(Star), R(8),
                 B(LdaFalse),
                 B(Star), R(4),
                 B(Mov), R(8), R(1),
-  /*   34 E> */ B(StackCheck),
   /*   43 S> */ B(Mov), R(1), R(0),
                 B(Ldar), R(8),
-                B(JumpLoop), U8(40), I8(0),
+  /*   34 E> */ B(JumpLoop), U8(39), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(6),
                 B(Star), R(5),
@@ -50,7 +48,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(5),
                 B(LdaTheHole),
-  /*   43 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(7),
                 B(Ldar), R(4),
                 B(JumpIfToBooleanTrue), U8(58),
@@ -96,8 +94,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [32, 75, 83],
-  [107, 140, 142],
+  [31, 73, 81],
+  [105, 138, 140],
 ]
 
 ---
@@ -107,9 +105,8 @@ snippet: "
 "
 frame size: 14
 parameter count: 1
-bytecode array length: 173
+bytecode array length: 171
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   68 S> */ B(GetIterator), R(0), U8(0), U8(2),
@@ -128,13 +125,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(9), U8(1),
                 B(LdaNamedProperty), R(9), U8(2), U8(8),
-                B(JumpIfToBooleanTrue), U8(27),
+                B(JumpIfToBooleanTrue), U8(26),
                 B(LdaNamedProperty), R(9), U8(3), U8(10),
                 B(Star), R(9),
                 B(LdaFalse),
                 B(Star), R(5),
                 B(Mov), R(9), R(2),
-  /*   54 E> */ B(StackCheck),
   /*   63 S> */ B(Mov), R(2), R(1),
   /*   73 S> */ B(LdaSmi), I8(1),
                 B(Mov), R(9), R(7),
@@ -198,8 +194,8 @@ constant pool: [
   Smi [9],
 ]
 handlers: [
-  [30, 77, 85],
-  [109, 142, 144],
+  [29, 75, 83],
+  [107, 140, 142],
 ]
 
 ---
@@ -211,9 +207,8 @@ snippet: "
 "
 frame size: 13
 parameter count: 1
-bytecode array length: 181
+bytecode array length: 179
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   48 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(37),
                 B(Star), R(4),
                 B(GetIterator), R(4), U8(1), U8(3),
@@ -232,13 +227,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(8), U8(1),
                 B(LdaNamedProperty), R(8), U8(2), U8(9),
-                B(JumpIfToBooleanTrue), U8(39),
+                B(JumpIfToBooleanTrue), U8(38),
                 B(LdaNamedProperty), R(8), U8(3), U8(11),
                 B(Star), R(8),
                 B(LdaFalse),
                 B(Star), R(4),
                 B(Mov), R(8), R(1),
-  /*   34 E> */ B(StackCheck),
   /*   43 S> */ B(Mov), R(1), R(0),
   /*   66 S> */ B(LdaSmi), I8(10),
   /*   72 E> */ B(TestEqual), R(0), U8(13),
@@ -248,7 +242,7 @@ bytecodes: [
   /*   97 E> */ B(TestEqual), R(0), U8(14),
                 B(JumpIfFalse), U8(4),
   /*  104 S> */ B(Jump), U8(5),
-                B(JumpLoop), U8(56), I8(0),
+  /*   34 E> */ B(JumpLoop), U8(55), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(6),
                 B(Star), R(5),
@@ -303,8 +297,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [32, 91, 99],
-  [123, 156, 158],
+  [31, 89, 97],
+  [121, 154, 156],
 ]
 
 ---
@@ -314,9 +308,8 @@ snippet: "
 "
 frame size: 13
 parameter count: 1
-bytecode array length: 187
+bytecode array length: 185
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   77 S> */ B(CreateArrayLiteral), U8(1), U8(1), U8(37),
@@ -337,14 +330,13 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(7), U8(1),
                 B(LdaNamedProperty), R(7), U8(3), U8(10),
-                B(JumpIfToBooleanTrue), U8(33),
+                B(JumpIfToBooleanTrue), U8(32),
                 B(LdaNamedProperty), R(7), U8(4), U8(12),
                 B(Star), R(7),
                 B(LdaFalse),
                 B(Star), R(3),
                 B(Ldar), R(7),
   /*   67 E> */ B(StaNamedProperty), R(0), U8(5), U8(14),
-  /*   62 E> */ B(StackCheck),
   /*   96 S> */ B(LdaNamedProperty), R(0), U8(5), U8(16),
                 B(Star), R(5),
                 B(LdaSmi), I8(1),
@@ -411,7 +403,7 @@ constant pool: [
   Smi [9],
 ]
 handlers: [
-  [38, 91, 99],
-  [123, 156, 158],
+  [37, 89, 97],
+  [121, 154, 156],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOfLoop.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOfLoop.golden
index 1f1cf6a332..a38d3d78dd 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOfLoop.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ForOfLoop.golden
@@ -15,9 +15,8 @@ snippet: "
 "
 frame size: 15
 parameter count: 2
-bytecode array length: 162
+bytecode array length: 160
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   34 S> */ B(GetIterator), R(arg0), U8(0), U8(2),
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowSymbolIteratorInvalid), R(0), U8(0),
@@ -34,17 +33,16 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(10), U8(1),
                 B(LdaNamedProperty), R(10), U8(1), U8(8),
-                B(JumpIfToBooleanTrue), U8(26),
+                B(JumpIfToBooleanTrue), U8(25),
                 B(LdaNamedProperty), R(10), U8(2), U8(10),
                 B(Star), R(10),
                 B(LdaFalse),
                 B(Star), R(6),
                 B(Mov), R(10), R(0),
-  /*   20 E> */ B(StackCheck),
   /*   29 S> */ B(Mov), R(0), R(2),
   /*   49 S> */ B(Mov), R(2), R(3),
                 B(Ldar), R(10),
-                B(JumpLoop), U8(43), I8(0),
+  /*   20 E> */ B(JumpLoop), U8(42), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(8),
                 B(Star), R(7),
@@ -53,7 +51,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(7),
                 B(LdaTheHole),
-  /*   49 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(9),
                 B(Ldar), R(6),
                 B(JumpIfToBooleanTrue), U8(58),
@@ -98,8 +96,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [26, 72, 80],
-  [104, 137, 139],
+  [25, 70, 78],
+  [102, 135, 137],
 ]
 
 ---
@@ -111,10 +109,9 @@ snippet: "
 "
 frame size: 20
 parameter count: 2
-bytecode array length: 246
+bytecode array length: 244
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(5),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(5),
                 B(PushContext), R(2),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(4),
@@ -146,13 +143,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(10), U8(1),
                 B(LdaNamedProperty), R(10), U8(3), U8(8),
-                B(JumpIfToBooleanTrue), U8(75),
+                B(JumpIfToBooleanTrue), U8(74),
                 B(LdaNamedProperty), R(10), U8(4), U8(10),
                 B(Star), R(10),
                 B(LdaFalse),
                 B(Star), R(6),
                 B(Mov), R(10), R(0),
-  /*   20 E> */ B(StackCheck),
                 B(CreateBlockContext), U8(5),
                 B(PushContext), R(11),
                 B(LdaTheHole),
@@ -177,7 +173,7 @@ bytecodes: [
   /*   41 E> */ B(CallUndefinedReceiver1), R(12), R(13), U8(14),
                 B(PopContext), R(11),
                 B(Mov), R(0), R(10),
-                B(JumpLoop), U8(92), I8(0),
+  /*   20 E> */ B(JumpLoop), U8(91), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(8),
                 B(Star), R(7),
@@ -237,8 +233,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [59, 154, 162],
-  [186, 219, 221],
+  [58, 152, 160],
+  [184, 217, 219],
 ]
 
 ---
@@ -250,9 +246,8 @@ snippet: "
 "
 frame size: 14
 parameter count: 2
-bytecode array length: 179
+bytecode array length: 177
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   34 S> */ B(GetIterator), R(arg0), U8(0), U8(2),
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowSymbolIteratorInvalid), R(0), U8(0),
@@ -269,13 +264,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(8), U8(1),
                 B(LdaNamedProperty), R(8), U8(1), U8(8),
-                B(JumpIfToBooleanTrue), U8(43),
+                B(JumpIfToBooleanTrue), U8(42),
                 B(LdaNamedProperty), R(8), U8(2), U8(10),
                 B(Star), R(8),
                 B(LdaFalse),
                 B(Star), R(4),
                 B(Mov), R(8), R(0),
-  /*   20 E> */ B(StackCheck),
                 B(CreateBlockContext), U8(3),
                 B(PushContext), R(9),
                 B(LdaTheHole),
@@ -287,7 +281,7 @@ bytecodes: [
   /*   67 E> */ B(CallUndefinedReceiver0), R(10), U8(12),
                 B(PopContext), R(9),
                 B(Mov), R(0), R(8),
-                B(JumpLoop), U8(60), I8(0),
+  /*   20 E> */ B(JumpLoop), U8(59), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(6),
                 B(Star), R(5),
@@ -343,8 +337,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [26, 89, 97],
-  [121, 154, 156],
+  [25, 87, 95],
+  [119, 152, 154],
 ]
 
 ---
@@ -356,9 +350,8 @@ snippet: "
 "
 frame size: 17
 parameter count: 2
-bytecode array length: 173
+bytecode array length: 171
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   41 S> */ B(GetIterator), R(arg0), U8(0), U8(2),
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowSymbolIteratorInvalid), R(0), U8(0),
@@ -375,13 +368,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(12), U8(1),
                 B(LdaNamedProperty), R(12), U8(1), U8(8),
-                B(JumpIfToBooleanTrue), U8(37),
+                B(JumpIfToBooleanTrue), U8(36),
                 B(LdaNamedProperty), R(12), U8(2), U8(10),
                 B(Star), R(12),
                 B(LdaFalse),
                 B(Star), R(8),
                 B(Mov), R(12), R(0),
-  /*   20 E> */ B(StackCheck),
   /*   31 S> */ B(LdaNamedProperty), R(0), U8(3), U8(12),
                 B(Star), R(3),
   /*   34 S> */ B(LdaNamedProperty), R(0), U8(4), U8(14),
@@ -389,7 +381,7 @@ bytecodes: [
   /*   56 S> */ B(Ldar), R(4),
   /*   58 E> */ B(Add), R(3), U8(16),
                 B(Star), R(5),
-                B(JumpLoop), U8(54), I8(0),
+  /*   20 E> */ B(JumpLoop), U8(53), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(10),
                 B(Star), R(9),
@@ -398,7 +390,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(9),
                 B(LdaTheHole),
-  /*   56 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(11),
                 B(Ldar), R(8),
                 B(JumpIfToBooleanTrue), U8(58),
@@ -445,8 +437,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [26, 83, 91],
-  [115, 148, 150],
+  [25, 81, 89],
+  [113, 146, 148],
 ]
 
 ---
@@ -458,13 +450,12 @@ snippet: "
 "
 frame size: 16
 parameter count: 2
-bytecode array length: 203
+bytecode array length: 201
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(5),
                 B(Mov), R(this), R(6),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(5), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(5), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(5), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(5),
@@ -491,17 +482,16 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(11), U8(1),
                 B(LdaNamedProperty), R(11), U8(4), U8(8),
-                B(JumpIfToBooleanTrue), U8(26),
+                B(JumpIfToBooleanTrue), U8(25),
                 B(LdaNamedProperty), R(11), U8(5), U8(10),
                 B(Star), R(11),
                 B(LdaFalse),
                 B(Star), R(7),
                 B(Mov), R(11), R(1),
-  /*   21 E> */ B(StackCheck),
   /*   30 S> */ B(Mov), R(1), R(3),
   /*   50 S> */ B(Mov), R(3), R(4),
                 B(Ldar), R(11),
-                B(JumpLoop), U8(43), I8(0),
+  /*   21 E> */ B(JumpLoop), U8(42), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(9),
                 B(Star), R(8),
@@ -510,7 +500,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(8),
                 B(LdaTheHole),
-  /*   50 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(10),
                 B(Ldar), R(7),
                 B(JumpIfToBooleanTrue), U8(58),
@@ -558,8 +548,8 @@ constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE [""],
 ]
 handlers: [
-  [67, 113, 121],
-  [145, 178, 180],
+  [66, 111, 119],
+  [143, 176, 178],
 ]
 
 ---
@@ -571,13 +561,12 @@ snippet: "
 "
 frame size: 15
 parameter count: 2
-bytecode array length: 247
+bytecode array length: 245
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(4),
@@ -604,13 +593,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(10), U8(1),
                 B(LdaNamedProperty), R(10), U8(5), U8(8),
-                B(JumpIfToBooleanTrue), U8(64),
+                B(JumpIfToBooleanTrue), U8(63),
                 B(LdaNamedProperty), R(10), U8(6), U8(10),
                 B(Star), R(10),
                 B(LdaFalse),
                 B(Star), R(6),
                 B(Mov), R(10), R(1),
-  /*   21 E> */ B(StackCheck),
   /*   30 S> */ B(Mov), R(1), R(3),
   /*   40 S> */ B(LdaFalse),
                 B(Star), R(12),
@@ -628,7 +616,7 @@ bytecodes: [
                 B(Mov), R(11), R(8),
                 B(Jump), U8(20),
                 B(Ldar), R(11),
-                B(JumpLoop), U8(81), I8(0),
+  /*   21 E> */ B(JumpLoop), U8(80), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(8),
                 B(Star), R(7),
@@ -678,7 +666,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [21],
-  Smi [119],
+  Smi [118],
   Smi [10],
   Smi [7],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["next"],
@@ -692,8 +680,8 @@ constant pool: [
   Smi [9],
 ]
 handlers: [
-  [67, 151, 159],
-  [183, 216, 218],
+  [66, 149, 157],
+  [181, 214, 216],
 ]
 
 ---
@@ -705,12 +693,11 @@ snippet: "
 "
 frame size: 17
 parameter count: 2
-bytecode array length: 217
+bytecode array length: 215
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(Mov), R(closure), R(5),
                 B(Mov), R(this), R(6),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(5), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(5), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(5),
   /*   40 S> */ B(GetIterator), R(arg0), U8(0), U8(2),
@@ -729,17 +716,16 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(12), U8(1),
                 B(LdaNamedProperty), R(12), U8(1), U8(8),
-                B(JumpIfToBooleanTrue), U8(26),
+                B(JumpIfToBooleanTrue), U8(25),
                 B(LdaNamedProperty), R(12), U8(2), U8(10),
                 B(Star), R(12),
                 B(LdaFalse),
                 B(Star), R(8),
                 B(Mov), R(12), R(1),
-  /*   26 E> */ B(StackCheck),
   /*   35 S> */ B(Mov), R(1), R(3),
   /*   55 S> */ B(Mov), R(3), R(4),
                 B(Ldar), R(12),
-                B(JumpLoop), U8(43), I8(0),
+  /*   26 E> */ B(JumpLoop), U8(42), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(10),
                 B(Star), R(9),
@@ -748,7 +734,7 @@ bytecodes: [
                 B(LdaZero),
                 B(Star), R(9),
                 B(LdaTheHole),
-  /*   55 E> */ B(SetPendingMessage),
+                B(SetPendingMessage),
                 B(Star), R(11),
                 B(Ldar), R(8),
                 B(JumpIfToBooleanTrue), U8(58),
@@ -813,9 +799,9 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [16, 189, 189],
-  [41, 87, 95],
-  [119, 152, 154],
+  [15, 187, 187],
+  [40, 85, 93],
+  [117, 150, 152],
 ]
 
 ---
@@ -827,13 +813,12 @@ snippet: "
 "
 frame size: 16
 parameter count: 2
-bytecode array length: 253
+bytecode array length: 251
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(4), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(4),
   /*   40 S> */ B(GetIterator), R(arg0), U8(0), U8(2),
@@ -852,13 +837,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(11), U8(1),
                 B(LdaNamedProperty), R(11), U8(2), U8(8),
-                B(JumpIfToBooleanTrue), U8(58),
+                B(JumpIfToBooleanTrue), U8(57),
                 B(LdaNamedProperty), R(11), U8(3), U8(10),
                 B(Star), R(11),
                 B(LdaFalse),
                 B(Star), R(7),
                 B(Mov), R(11), R(1),
-  /*   26 E> */ B(StackCheck),
   /*   35 S> */ B(Mov), R(1), R(3),
   /*   45 S> */ B(Mov), R(0), R(12),
                 B(Mov), R(3), R(13),
@@ -874,7 +858,7 @@ bytecodes: [
                 B(Ldar), R(12),
                 B(ReThrow),
                 B(Ldar), R(12),
-                B(JumpLoop), U8(75), I8(0),
+  /*   26 E> */ B(JumpLoop), U8(74), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(9),
                 B(Star), R(8),
@@ -940,7 +924,7 @@ bytecodes: [
   /*   54 S> */ B(Return),
 ]
 constant pool: [
-  Smi [97],
+  Smi [96],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["next"],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["done"],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["value"],
@@ -949,8 +933,8 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [20, 225, 225],
-  [45, 123, 131],
-  [155, 188, 190],
+  [19, 223, 223],
+  [44, 121, 129],
+  [153, 186, 188],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/FunctionLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/FunctionLiterals.golden
index 0416d1815a..d73ca7d69c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/FunctionLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/FunctionLiterals.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateClosure), U8(0), U8(0), U8(2),
   /*   54 S> */ B(Return),
 ]
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateClosure), U8(0), U8(0), U8(2),
                 B(Star), R(0),
   /*   56 E> */ B(CallUndefinedReceiver0), R(0), U8(0),
@@ -49,9 +47,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateClosure), U8(0), U8(0), U8(2),
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/GenerateTestUndetectable.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/GenerateTestUndetectable.golden
index 02f8f49ece..071b6ae8ff 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/GenerateTestUndetectable.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/GenerateTestUndetectable.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -44,9 +43,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -74,9 +72,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -104,9 +101,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -134,9 +130,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -163,9 +158,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -192,9 +186,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
@@ -221,9 +214,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   46 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   63 S> */ B(LdaSmi), I8(10),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Generators.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Generators.golden
index c84e6ec0eb..c3f8b980cf 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Generators.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Generators.golden
@@ -13,13 +13,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 44
+bytecode array length: 43
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(1), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(1),
@@ -48,13 +47,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 80
+bytecode array length: 79
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(1), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(1),
@@ -100,13 +98,12 @@ snippet: "
 "
 frame size: 15
 parameter count: 1
-bytecode array length: 253
+bytecode array length: 251
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(4),
                 B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(4),
@@ -135,13 +132,12 @@ bytecodes: [
                 B(JumpIfJSReceiver), U8(7),
                 B(CallRuntime), U16(Runtime::kThrowIteratorResultNotAnObject), R(10), U8(1),
                 B(LdaNamedProperty), R(10), U8(6), U8(9),
-                B(JumpIfToBooleanTrue), U8(64),
+                B(JumpIfToBooleanTrue), U8(63),
                 B(LdaNamedProperty), R(10), U8(7), U8(11),
                 B(Star), R(10),
                 B(LdaFalse),
                 B(Star), R(6),
                 B(Mov), R(10), R(1),
-  /*   16 E> */ B(StackCheck),
   /*   25 S> */ B(Mov), R(1), R(3),
   /*   36 S> */ B(LdaFalse),
                 B(Star), R(12),
@@ -159,7 +155,7 @@ bytecodes: [
                 B(Mov), R(11), R(8),
                 B(Jump), U8(20),
                 B(Ldar), R(11),
-                B(JumpLoop), U8(81), I8(0),
+  /*   16 E> */ B(JumpLoop), U8(80), I8(0),
                 B(LdaSmi), I8(-1),
                 B(Star), R(8),
                 B(Star), R(7),
@@ -209,7 +205,7 @@ bytecodes: [
 ]
 constant pool: [
   Smi [21],
-  Smi [125],
+  Smi [124],
   Smi [10],
   Smi [7],
   ARRAY_BOILERPLATE_DESCRIPTION_TYPE,
@@ -224,8 +220,8 @@ constant pool: [
   Smi [9],
 ]
 handlers: [
-  [73, 157, 165],
-  [189, 222, 224],
+  [72, 155, 163],
+  [187, 220, 222],
 ]
 
 ---
@@ -236,13 +232,12 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 205
+bytecode array length: 204
 bytecodes: [
-  /*   38 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(this), R(2),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
+  /*   38 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(1), U8(2),
                 B(Star), R(0),
   /*   38 E> */ B(SuspendGenerator), R(0), R(0), U8(1), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCompoundExpressions.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCompoundExpressions.golden
index b24e5d0aa1..808f608f25 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCompoundExpressions.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCompoundExpressions.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   26 E> */ B(StackCheck),
   /*   31 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(BitwiseAndSmi), I8(1), U8(2),
   /*   45 E> */ B(StaGlobal), U8(0), U8(3),
@@ -36,9 +35,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   27 E> */ B(StackCheck),
   /*   32 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(AddSmi), I8(1), U8(2),
   /*   51 E> */ B(StaGlobal), U8(0), U8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden
index f0479d594d..dd6f8ea9e7 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalCountOperators.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   26 E> */ B(StackCheck),
   /*   31 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Inc), U8(2),
   /*   40 E> */ B(StaGlobal), U8(0), U8(3),
@@ -36,9 +35,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   26 E> */ B(StackCheck),
   /*   31 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(ToNumeric), U8(2),
                 B(Star), R(0),
@@ -61,9 +59,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   27 E> */ B(StackCheck),
   /*   46 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Dec), U8(2),
   /*   55 E> */ B(StaGlobal), U8(0), U8(3),
@@ -83,9 +80,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   27 E> */ B(StackCheck),
   /*   32 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(ToNumeric), U8(2),
                 B(Star), R(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalDelete.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalDelete.golden
index e1994bcdd2..4167138f1f 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalDelete.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/GlobalDelete.golden
@@ -16,9 +16,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   32 E> */ B(StackCheck),
   /*   39 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaConstant), U8(1),
@@ -43,9 +42,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   28 E> */ B(StackCheck),
   /*   51 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
@@ -68,9 +66,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   32 E> */ B(StackCheck),
   /*   39 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
                 B(CallRuntime), U16(Runtime::kDeleteLookupSlot), R(0), U8(1),
@@ -92,9 +89,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   18 E> */ B(StackCheck),
   /*   25 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
                 B(CallRuntime), U16(Runtime::kDeleteLookupSlot), R(0), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/HeapNumberConstants.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/HeapNumberConstants.golden
index d6b6bb6c60..49a80d13c9 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/HeapNumberConstants.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/HeapNumberConstants.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaConstant), U8(0),
   /*   45 S> */ B(Return),
 ]
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   47 S> */ B(LdaConstant), U8(1),
@@ -50,9 +48,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   48 S> */ B(LdaConstant), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithOneshotOpt.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithOneshotOpt.golden
index 56b6e0afac..8f45fff2cb 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithOneshotOpt.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithOneshotOpt.golden
@@ -21,10 +21,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 40
+bytecode array length: 39
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateEmptyObjectLiteral),
   /*   31 E> */ B(StaGlobal), U8(0), U8(0),
@@ -65,10 +64,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 69
+bytecode array length: 67
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateEmptyObjectLiteral),
   /*   31 E> */ B(StaGlobal), U8(0), U8(0),
@@ -78,8 +76,7 @@ bytecodes: [
                 B(Star), R(1),
                 B(LdaSmi), I8(5),
   /*   59 E> */ B(TestLessThan), R(1), U8(6),
-                B(JumpIfFalse), U8(43),
-  /*   45 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(42),
   /*   81 S> */ B(LdaGlobal), U8(0), U8(7),
                 B(Star), R(1),
                 B(LdaSmi), I8(2),
@@ -93,7 +90,7 @@ bytecodes: [
   /*   66 S> */ B(LdaGlobal), U8(1), U8(4),
                 B(Inc), U8(15),
   /*   66 E> */ B(StaGlobal), U8(1), U8(2),
-                B(JumpLoop), U8(50), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(49), I8(0),
   /*  149 S> */ B(LdaNamedPropertyNoFeedback), R(0), U8(4),
   /*  156 S> */ B(Return),
 ]
@@ -124,10 +121,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 70
+bytecode array length: 68
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateEmptyObjectLiteral),
   /*   31 E> */ B(StaGlobal), U8(0), U8(0),
@@ -137,8 +133,7 @@ bytecodes: [
                 B(Star), R(1),
                 B(LdaSmi), I8(4),
   /*   68 E> */ B(TestGreaterThan), R(1), U8(6),
-                B(JumpIfFalse), U8(43),
-  /*   60 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(42),
   /*   85 S> */ B(LdaGlobal), U8(0), U8(7),
                 B(Star), R(1),
                 B(LdaSmi), I8(2),
@@ -152,7 +147,7 @@ bytecodes: [
   /*  128 S> */ B(LdaGlobal), U8(1), U8(4),
                 B(Dec), U8(15),
   /*  129 E> */ B(StaGlobal), U8(1), U8(2),
-                B(JumpLoop), U8(50), I8(0),
+  /*   60 E> */ B(JumpLoop), U8(49), I8(0),
   /*  168 S> */ B(LdaNamedPropertyNoFeedback), R(0), U8(4),
   /*  175 S> */ B(Return),
 ]
@@ -183,16 +178,14 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 70
+bytecode array length: 68
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateEmptyObjectLiteral),
   /*   31 E> */ B(StaGlobal), U8(0), U8(0),
   /*   45 S> */ B(LdaSmi), I8(4),
   /*   47 E> */ B(StaGlobal), U8(1), U8(2),
-  /*   60 E> */ B(StackCheck),
   /*   75 S> */ B(LdaGlobal), U8(0), U8(4),
                 B(Star), R(1),
                 B(LdaSmi), I8(2),
@@ -211,7 +204,7 @@ bytecodes: [
                 B(LdaSmi), I8(4),
   /*  141 E> */ B(TestGreaterThan), R(1), U8(15),
                 B(JumpIfFalse), U8(5),
-                B(JumpLoop), U8(50), I8(0),
+  /*   60 E> */ B(JumpLoop), U8(49), I8(0),
   /*  171 S> */ B(LdaNamedPropertyNoFeedback), R(0), U8(4),
   /*  178 S> */ B(Return),
 ]
@@ -244,10 +237,9 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 71
+bytecode array length: 70
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
@@ -297,10 +289,9 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(LdaConstant), U8(0),
                 B(Star), R(3),
@@ -330,10 +321,9 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(LdaConstant), U8(0),
                 B(Star), R(3),
@@ -374,10 +364,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 137
+bytecode array length: 136
 bytecodes: [
-  /*  237 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*  237 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*  255 S> */ B(LdaNamedPropertyNoFeedback), R(this), U8(0),
                 B(Star), R(1),
@@ -469,10 +458,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 140
+bytecode array length: 139
 bytecodes: [
-  /*  189 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*  189 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*  202 S> */ B(LdaUndefined),
                 B(Star), R(2),
@@ -567,10 +555,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 43
+bytecode array length: 42
 bytecodes: [
-  /*   79 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   79 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   93 S> */ B(CreateEmptyObjectLiteral),
   /*   95 E> */ B(StaGlobal), U8(0), U8(0),
@@ -616,10 +603,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 43
+bytecode array length: 42
 bytecodes: [
-  /*   76 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   76 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   92 S> */ B(CreateEmptyObjectLiteral),
   /*   94 E> */ B(StaGlobal), U8(0), U8(0),
@@ -657,9 +643,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   25 E> */ B(StackCheck),
   /*   32 S> */ B(LdaSmi), I8(3),
   /*   36 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   41 S> */ B(Ldar), R(arg0),
@@ -680,9 +665,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   26 E> */ B(StackCheck),
   /*   33 S> */ B(LdaSmi), I8(3),
   /*   37 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   42 S> */ B(Ldar), R(arg0),
@@ -703,9 +687,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   37 S> */ B(LdaSmi), I8(3),
   /*   41 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   46 S> */ B(Ldar), R(arg0),
@@ -727,9 +710,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   29 E> */ B(StackCheck),
   /*   36 S> */ B(LdaSmi), I8(3),
   /*   40 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   45 S> */ B(Ldar), R(arg0),
@@ -751,10 +733,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 2
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   46 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   46 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(2),
@@ -784,10 +765,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 2
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(1),
                 B(Ldar), R(arg0),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithoutOneshotOpt.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithoutOneshotOpt.golden
index c3b8dcc22f..c911947481 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithoutOneshotOpt.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/IIFEWithoutOneshotOpt.golden
@@ -20,10 +20,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 42
+bytecode array length: 41
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateEmptyObjectLiteral),
   /*   31 E> */ B(StaGlobal), U8(0), U8(0),
@@ -68,10 +67,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 65
+bytecode array length: 64
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*   16 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*   29 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
   /*   31 E> */ B(StaGlobal), U8(1), U8(1),
@@ -128,10 +126,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 144
+bytecode array length: 143
 bytecodes: [
-  /*  237 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*  237 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*  255 S> */ B(LdaNamedProperty), R(this), U8(0), U8(0),
                 B(Star), R(1),
@@ -221,10 +218,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 126
+bytecode array length: 125
 bytecodes: [
-  /*  189 E> */ B(StackCheck),
-                B(CreateMappedArguments),
+  /*  189 E> */ B(CreateMappedArguments),
                 B(Star), R(0),
   /*  202 S> */ B(LdaGlobal), U8(0), U8(0),
                 B(Star), R(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/IfConditions.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/IfConditions.golden
index 46d972af0c..de6b5e0844 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/IfConditions.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/IfConditions.golden
@@ -19,9 +19,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   55 S> */ B(LdaSmi), I8(-1),
   /*   65 S> */ B(Return),
 ]
@@ -43,9 +42,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   36 S> */ B(LdaSmi), I8(1),
   /*   45 S> */ B(Return),
 ]
@@ -67,9 +65,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   59 S> */ B(LdaSmi), I8(-1),
   /*   69 S> */ B(Return),
 ]
@@ -89,9 +86,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   17 S> */ B(LdaUndefined),
   /*   48 S> */ B(Return),
 ]
@@ -114,9 +110,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 21
+bytecode array length: 20
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   30 S> */ B(JumpIfToBooleanFalse), U8(11),
@@ -147,9 +142,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   18 S> */ B(LdaZero),
   /*   24 E> */ B(TestLessThanOrEqual), R(arg0), U8(0),
                 B(JumpIfFalse), U8(7),
@@ -169,9 +163,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(Ldar), R(arg1),
   /*   25 E> */ B(TestIn), R(arg0), U8(0),
                 B(JumpIfFalse), U8(7),
@@ -256,9 +249,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 2
-bytecode array length: 27
+bytecode array length: 26
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   24 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   35 S> */ B(LdaZero),
@@ -353,9 +345,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   36 S> */ B(LdaZero),
@@ -390,9 +381,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 83
+bytecode array length: 82
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   21 S> */ B(Ldar), R(arg1),
   /*   27 E> */ B(TestEqual), R(arg0), U8(0),
                 B(JumpIfFalse), U8(5),
@@ -455,9 +445,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   30 S> */ B(JumpIfToBooleanFalse), U8(5),
@@ -486,9 +475,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 34
+bytecode array length: 33
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   21 S> */ B(Ldar), R(arg1),
   /*   27 E> */ B(TestEqual), R(arg0), U8(0),
                 B(JumpIfTrue), U8(8),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/IntegerConstants.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/IntegerConstants.golden
index ea0f55d478..951b3543a8 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/IntegerConstants.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/IntegerConstants.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(ExtraWide), B(LdaSmi), I32(12345678),
   /*   50 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(Wide), B(LdaSmi), I16(1234),
                 B(Star), R(0),
   /*   48 S> */ B(Wide), B(LdaSmi), I16(5678),
@@ -47,9 +45,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(Wide), B(LdaSmi), I16(1234),
                 B(Star), R(0),
   /*   48 S> */ B(Wide), B(LdaSmi), I16(1234),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariable.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariable.golden
index a7900cf8eb..0ee86f4cea 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariable.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariable.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
                 B(LdaUndefined),
@@ -30,9 +29,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   55 S> */ B(Return),
@@ -48,9 +46,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaTheHole),
                 B(Star), R(0),
   /*   42 S> */ B(LdaSmi), I8(20),
@@ -73,9 +70,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(20),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariableContextSlot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariableContextSlot.golden
index 61f898d5d7..fe82887e3c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariableContextSlot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LetVariableContextSlot.golden
@@ -11,10 +11,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -35,10 +34,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 16
+bytecode array length: 15
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -59,10 +57,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -89,10 +86,9 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 19
+bytecode array length: 18
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   30 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LoadGlobal.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LoadGlobal.golden
index c34d6bd739..3199c09d94 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LoadGlobal.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LoadGlobal.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   21 E> */ B(StackCheck),
   /*   26 S> */ B(LdaGlobal), U8(0), U8(0),
   /*   35 S> */ B(Return),
 ]
@@ -34,9 +33,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   27 E> */ B(StackCheck),
   /*   32 S> */ B(LdaGlobal), U8(0), U8(0),
   /*   41 S> */ B(Return),
 ]
@@ -54,9 +52,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
   /*   22 S> */ B(LdaGlobal), U8(0), U8(0),
   /*   31 S> */ B(Return),
 ]
@@ -205,9 +202,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 523
+bytecode array length: 522
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
   /*   33 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   41 S> */ B(LdaNamedProperty), R(0), U8(0), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LogicalExpressions.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LogicalExpressions.golden
index 9f51448614..ddcf588467 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LogicalExpressions.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LogicalExpressions.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanTrue), U8(4),
@@ -31,9 +30,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
@@ -53,9 +51,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(4),
@@ -73,9 +70,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(LdaZero),
@@ -95,9 +91,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanTrue), U8(4),
@@ -115,9 +110,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 24
+bytecode array length: 23
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(2),
                 B(Star), R(0),
   /*   49 S> */ B(LdaSmi), I8(3),
@@ -174,9 +168,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 276
+bytecode array length: 275
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -360,9 +353,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 275
+bytecode array length: 274
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -546,9 +538,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 279
+bytecode array length: 278
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -733,9 +724,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 278
+bytecode array length: 277
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -888,9 +878,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaZero),
   /*   48 S> */ B(Return),
 ]
@@ -905,9 +894,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(1),
   /*   48 S> */ B(Return),
 ]
@@ -922,9 +910,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(4),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlot.golden
index f7da45c224..f7a4289e61 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlot.golden
@@ -12,10 +12,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 63
+bytecode array length: 62
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
@@ -57,10 +56,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 64
+bytecode array length: 63
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
@@ -103,10 +101,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 64
+bytecode array length: 63
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
@@ -154,10 +151,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 63
+bytecode array length: 62
 bytecodes: [
-  /*   38 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   38 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
@@ -204,10 +200,9 @@ snippet: "
 "
 frame size: 10
 parameter count: 1
-bytecode array length: 63
+bytecode array length: 62
 bytecodes: [
-  /*   34 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   34 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(1),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlotInEval.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlotInEval.golden
index 0ace6d1dc5..f8b66ce3d2 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlotInEval.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/LookupSlotInEval.golden
@@ -17,9 +17,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaLookupGlobalSlot), U8(0), U8(0), U8(1),
   /*   24 S> */ B(Return),
 ]
@@ -40,9 +39,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaSmi), I8(10),
   /*   17 E> */ B(StaLookupSlot), U8(0), U8(0),
                 B(LdaUndefined),
@@ -65,9 +63,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   29 S> */ B(LdaSmi), I8(10),
   /*   31 E> */ B(StaLookupSlot), U8(0), U8(1),
                 B(LdaUndefined),
@@ -90,9 +87,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(LdaLookupGlobalSlotInsideTypeof), U8(0), U8(0), U8(1),
                 B(TypeOf),
   /*   31 S> */ B(Return),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Modules.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Modules.golden
index b21dea1dcb..854a78c921 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Modules.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Modules.golden
@@ -11,37 +11,30 @@ top level: yes
 snippet: "
   import \"bar\";
 "
-frame size: 5
-parameter count: 2
-bytecode array length: 62
+frame size: 4
+parameter count: 1
+bytecode array length: 47
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   14 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
   /*   14 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
 ]
@@ -52,37 +45,30 @@ handlers: [
 snippet: "
   import {foo} from \"bar\";
 "
-frame size: 5
-parameter count: 2
-bytecode array length: 62
+frame size: 4
+parameter count: 1
+bytecode array length: 47
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   25 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
   /*   25 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
 ]
@@ -95,50 +81,43 @@ snippet: "
   goo(42);
   { let x; { goo(42) } };
 "
-frame size: 6
-parameter count: 2
-bytecode array length: 92
+frame size: 5
+parameter count: 1
+bytecode array length: 77
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
-                B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   65 S> */ B(Return),
   /*   32 S> */ B(LdaModuleVariable), I8(-1), U8(0),
-                B(ThrowReferenceErrorIfHole), U8(4),
-                B(Star), R(4),
+                B(ThrowReferenceErrorIfHole), U8(3),
+                B(Star), R(3),
                 B(LdaSmi), I8(42),
-                B(Star), R(5),
-  /*   32 E> */ B(CallUndefinedReceiver1), R(4), R(5), U8(0),
+                B(Star), R(4),
+  /*   32 E> */ B(CallUndefinedReceiver1), R(3), R(4), U8(0),
   /*   47 S> */ B(LdaUndefined),
                 B(Star), R(2),
   /*   52 S> */ B(LdaModuleVariable), I8(-1), U8(0),
-                B(ThrowReferenceErrorIfHole), U8(4),
-                B(Star), R(4),
+                B(ThrowReferenceErrorIfHole), U8(3),
+                B(Star), R(3),
                 B(LdaSmi), I8(42),
-                B(Star), R(5),
-  /*   52 E> */ B(CallUndefinedReceiver1), R(4), R(5), U8(2),
+                B(Star), R(4),
+  /*   52 E> */ B(CallUndefinedReceiver1), R(3), R(4), U8(2),
                 B(Star), R(1),
   /*   65 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["goo"],
@@ -152,29 +131,23 @@ snippet: "
   foo++;
   { let x; { foo++ } };
 "
-frame size: 6
-parameter count: 2
-bytecode array length: 90
+frame size: 5
+parameter count: 1
+bytecode array length: 75
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
-                B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   50 S> */ B(Return),
   /*   17 S> */ B(LdaSmi), I8(42),
   /*   17 E> */ B(StaModuleVariable), I8(1), U8(0),
@@ -185,16 +158,15 @@ bytecodes: [
                 B(Star), R(2),
   /*   39 S> */ B(LdaModuleVariable), I8(1), U8(0),
                 B(ToNumeric), U8(1),
-                B(Star), R(4),
+                B(Star), R(3),
                 B(Inc), U8(1),
   /*   42 E> */ B(StaModuleVariable), I8(1), U8(0),
-                B(Mov), R(4), R(1),
+                B(Mov), R(3), R(1),
                 B(Ldar), R(1),
   /*   50 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
 ]
@@ -207,32 +179,28 @@ snippet: "
   foo++;
   { let x; { foo++ } };
 "
-frame size: 6
-parameter count: 2
-bytecode array length: 96
+frame size: 5
+parameter count: 1
+bytecode array length: 89
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Star), R(0),
                 B(LdaConstant), U8(1),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
+                B(Star), R(3),
                 B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
-                B(Star), R(0),
-                B(LdaTheHole),
-                B(StaModuleVariable), I8(1), U8(0),
+                B(CallRuntime), U16(Runtime::kDeclareModuleExports), R(3), U8(2),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
                 B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   50 S> */ B(Return),
   /*   17 S> */ B(LdaSmi), I8(42),
   /*   17 E> */ B(StaModuleVariable), I8(1), U8(0),
@@ -243,16 +211,16 @@ bytecodes: [
                 B(Star), R(2),
   /*   39 S> */ B(LdaModuleVariable), I8(1), U8(0),
                 B(ToNumeric), U8(1),
-                B(Star), R(4),
+                B(Star), R(3),
                 B(Inc), U8(1),
   /*   42 E> */ B(StaModuleVariable), I8(1), U8(0),
-                B(Mov), R(4), R(1),
+                B(Mov), R(3), R(1),
                 B(Ldar), R(1),
   /*   50 S> */ B(Return),
 ]
 constant pool: [
-  Smi [41],
-  SCOPE_INFO_TYPE,
+  Smi [35],
+  FIXED_ARRAY_TYPE,
   Smi [10],
   Smi [7],
 ]
@@ -265,32 +233,28 @@ snippet: "
   foo++;
   { let x; { foo++ } };
 "
-frame size: 6
-parameter count: 2
-bytecode array length: 100
+frame size: 5
+parameter count: 1
+bytecode array length: 93
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Star), R(0),
                 B(LdaConstant), U8(1),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
+                B(Star), R(3),
                 B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
-                B(Star), R(0),
-                B(LdaTheHole),
-                B(StaModuleVariable), I8(1), U8(0),
+                B(CallRuntime), U16(Runtime::kDeclareModuleExports), R(3), U8(2),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
                 B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   52 S> */ B(Return),
   /*   19 S> */ B(LdaSmi), I8(42),
   /*   19 E> */ B(StaModuleVariable), I8(1), U8(0),
@@ -301,16 +265,16 @@ bytecodes: [
                 B(Star), R(2),
   /*   41 S> */ B(LdaModuleVariable), I8(1), U8(0),
                 B(ToNumeric), U8(1),
-                B(Star), R(4),
+                B(Star), R(3),
                 B(Inc), U8(1),
   /*   44 E> */ B(CallRuntime), U16(Runtime::kThrowConstAssignError), R(0), U8(0),
-                B(Mov), R(4), R(1),
+                B(Mov), R(3), R(1),
                 B(Ldar), R(1),
   /*   52 S> */ B(Return),
 ]
 constant pool: [
-  Smi [41],
-  SCOPE_INFO_TYPE,
+  Smi [35],
+  FIXED_ARRAY_TYPE,
   Smi [10],
   Smi [7],
 ]
@@ -321,42 +285,38 @@ handlers: [
 snippet: "
   export default (function () {});
 "
-frame size: 5
-parameter count: 2
-bytecode array length: 75
+frame size: 4
+parameter count: 1
+bytecode array length: 68
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
+                B(Star), R(0),
                 B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
+                B(Star), R(2),
                 B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
-                B(Star), R(0),
-                B(LdaTheHole),
-                B(StaModuleVariable), I8(1), U8(0),
+                B(CallRuntime), U16(Runtime::kDeclareModuleExports), R(2), U8(2),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
                 B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   33 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(CreateClosure), U8(4), U8(0), U8(0),
                 B(StaModuleVariable), I8(1), U8(0),
                 B(Ldar), R(1),
   /*   33 S> */ B(Return),
 ]
 constant pool: [
-  Smi [41],
-  SCOPE_INFO_TYPE,
+  Smi [35],
+  FIXED_ARRAY_TYPE,
   Smi [10],
   Smi [7],
   SHARED_FUNCTION_INFO_TYPE,
@@ -368,51 +328,47 @@ handlers: [
 snippet: "
   export default (class {});
 "
-frame size: 7
-parameter count: 2
-bytecode array length: 96
+frame size: 6
+parameter count: 1
+bytecode array length: 89
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
+                B(Star), R(0),
                 B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
+                B(Star), R(2),
                 B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
-                B(Star), R(0),
-                B(LdaTheHole),
-                B(StaModuleVariable), I8(1), U8(0),
+                B(CallRuntime), U16(Runtime::kDeclareModuleExports), R(2), U8(2),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
                 B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   27 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(LdaTheHole),
-                B(Star), R(6),
+                B(Star), R(5),
                 B(CreateClosure), U8(5), U8(0), U8(0),
-                B(Star), R(3),
+                B(Star), R(2),
                 B(LdaConstant), U8(4),
-                B(Star), R(4),
-                B(Mov), R(3), R(5),
-                B(CallRuntime), U16(Runtime::kDefineClass), R(4), U8(3),
-                B(Star), R(4),
-                B(Ldar), R(5),
+                B(Star), R(3),
+                B(Mov), R(2), R(4),
+                B(CallRuntime), U16(Runtime::kDefineClass), R(3), U8(3),
+                B(Star), R(3),
+                B(Ldar), R(4),
                 B(StaModuleVariable), I8(1), U8(0),
                 B(Ldar), R(1),
   /*   27 S> */ B(Return),
 ]
 constant pool: [
-  Smi [41],
-  SCOPE_INFO_TYPE,
+  Smi [35],
+  FIXED_ARRAY_TYPE,
   Smi [10],
   Smi [7],
   FIXED_ARRAY_TYPE,
@@ -425,37 +381,30 @@ handlers: [
 snippet: "
   export {foo as goo} from \"bar\"
 "
-frame size: 5
-parameter count: 2
-bytecode array length: 62
+frame size: 4
+parameter count: 1
+bytecode array length: 47
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   31 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
   /*   31 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
 ]
@@ -466,37 +415,30 @@ handlers: [
 snippet: "
   export * from \"bar\"
 "
-frame size: 5
-parameter count: 2
-bytecode array length: 62
+frame size: 4
+parameter count: 1
+bytecode array length: 47
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(3),
-                B(Mov), R(arg0), R(2),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(2), U8(2),
-                B(PushContext), R(2),
-                B(Mov), R(closure), R(3),
-                B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+                B(Mov), R(closure), R(2),
+                B(Mov), R(this), R(3),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
                 B(Star), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(3),
-                B(Star), R(3),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(2),
+                B(Star), R(2),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(3),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(2),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(3),
+                B(Ldar), R(2),
   /*   20 S> */ B(Return),
-                B(Mov), R(3), R(1),
+                B(Mov), R(2), R(1),
                 B(Ldar), R(1),
   /*   20 S> */ B(Return),
 ]
 constant pool: [
-  Smi [35],
-  SCOPE_INFO_TYPE,
+  Smi [21],
   Smi [10],
   Smi [7],
 ]
@@ -508,46 +450,39 @@ snippet: "
   import * as foo from \"bar\"
   foo.f(foo, foo.x);
 "
-frame size: 8
-parameter count: 2
-bytecode array length: 89
+frame size: 7
+parameter count: 1
+bytecode array length: 74
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
-                B(LdaConstant), U8(1),
-                B(Star), R(4),
-                B(Mov), R(arg0), R(3),
-                B(CallRuntime), U16(Runtime::kPushModuleContext), R(3), U8(2),
-                B(PushContext), R(3),
-                B(Mov), R(closure), R(4),
-                B(Mov), R(this), R(5),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(4), U8(2),
+                B(Mov), R(closure), R(3),
+                B(Mov), R(this), R(4),
+  /*    0 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
                 B(Star), R(0),
                 B(LdaZero),
-                B(Star), R(4),
-                B(CallRuntime), U16(Runtime::kGetModuleNamespace), R(4), U8(1),
+                B(Star), R(3),
+                B(CallRuntime), U16(Runtime::kGetModuleNamespace), R(3), U8(1),
                 B(Star), R(1),
                 B(Ldar), R(0),
-  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(4), U8(0),
-                B(ResumeGenerator), R(0), R(0), U8(4),
-                B(Star), R(4),
+  /*    0 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
+                B(ResumeGenerator), R(0), R(0), U8(3),
+                B(Star), R(3),
                 B(InvokeIntrinsic), U8(Runtime::k_GeneratorGetResumeMode), R(0), U8(1),
-                B(SwitchOnSmiNoFeedback), U8(2), U8(2), I8(0),
-                B(Ldar), R(4),
+                B(SwitchOnSmiNoFeedback), U8(1), U8(2), I8(0),
+                B(Ldar), R(3),
   /*    0 E> */ B(Throw),
-                B(Ldar), R(4),
+                B(Ldar), R(3),
   /*   46 S> */ B(Return),
-  /*   31 S> */ B(LdaNamedProperty), R(1), U8(4), U8(0),
-                B(Star), R(4),
-  /*   42 E> */ B(LdaNamedProperty), R(1), U8(5), U8(2),
-                B(Star), R(7),
-  /*   31 E> */ B(CallProperty2), R(4), R(1), R(1), R(7), U8(4),
+  /*   31 S> */ B(LdaNamedProperty), R(1), U8(3), U8(0),
+                B(Star), R(3),
+  /*   42 E> */ B(LdaNamedProperty), R(1), U8(4), U8(2),
+                B(Star), R(6),
+  /*   31 E> */ B(CallProperty2), R(3), R(1), R(1), R(6), U8(4),
                 B(Star), R(2),
   /*   46 S> */ B(Return),
 ]
 constant pool: [
-  Smi [47],
-  SCOPE_INFO_TYPE,
+  Smi [33],
   Smi [10],
   Smi [7],
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["f"],
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/NewAndSpread.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/NewAndSpread.golden
index 2d994ac100..d0ab8d1281 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/NewAndSpread.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/NewAndSpread.golden
@@ -12,10 +12,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 48
+bytecode array length: 47
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -51,10 +50,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 51
+bytecode array length: 50
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -92,10 +90,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 122
+bytecode array length: 121
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/NewTarget.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/NewTarget.golden
index 53ef573033..a7681926c9 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/NewTarget.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/NewTarget.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(Ldar), R(0),
   /*   52 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaUndefined),
   /*   46 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ObjectLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ObjectLiterals.golden
index 82c47ff88d..a5256793a0 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ObjectLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ObjectLiterals.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateEmptyObjectLiteral),
   /*   45 S> */ B(Return),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
   /*   70 S> */ B(Return),
 ]
@@ -46,9 +44,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
@@ -71,9 +68,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
@@ -97,9 +93,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   49 E> */ B(CreateClosure), U8(1), U8(0), U8(2),
@@ -121,9 +116,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 18
+bytecode array length: 17
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
   /*   43 E> */ B(CreateClosure), U8(1), U8(0), U8(2),
@@ -145,9 +139,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
                 B(LdaConstant), U8(1),
@@ -177,9 +170,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 37
+bytecode array length: 36
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
                 B(LdaConstant), U8(1),
@@ -210,9 +202,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 33
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(0),
                 B(LdaConstant), U8(1),
@@ -242,9 +233,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
@@ -269,9 +259,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(57),
   /*   61 S> */ B(Return),
 ]
@@ -287,9 +276,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 24
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   50 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
@@ -314,9 +302,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 31
+bytecode array length: 30
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   50 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
@@ -344,9 +331,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   50 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
@@ -375,9 +361,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 64
+bytecode array length: 63
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   50 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/OuterContextVariables.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/OuterContextVariables.golden
index 146715e03a..bb4aac932e 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/OuterContextVariables.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/OuterContextVariables.golden
@@ -20,9 +20,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   97 E> */ B(StackCheck),
   /*  102 S> */ B(LdaImmutableContextSlot), R(context), U8(2), U8(1),
                 B(Star), R(0),
                 B(LdaImmutableCurrentContextSlot), U8(2),
@@ -48,9 +47,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   97 E> */ B(StackCheck),
   /*  102 S> */ B(LdaImmutableCurrentContextSlot), U8(2),
   /*  111 E> */ B(StaContextSlot), R(context), U8(2), U8(1),
                 B(LdaUndefined),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Parameters.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Parameters.golden
index 81d6408e14..d52e3016b4 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Parameters.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Parameters.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   15 S> */ B(Ldar), R(this),
   /*   27 S> */ B(Return),
 ]
@@ -31,9 +30,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(Ldar), R(arg0),
   /*   31 S> */ B(Return),
 ]
@@ -49,9 +47,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(Ldar), R(this),
   /*   31 S> */ B(Return),
 ]
@@ -67,9 +64,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 8
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   55 S> */ B(Ldar), R(arg3),
   /*   67 S> */ B(Return),
 ]
@@ -85,9 +81,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 8
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   55 S> */ B(Ldar), R(this),
   /*   67 S> */ B(Return),
 ]
@@ -103,9 +98,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(LdaSmi), I8(1),
                 B(Star), R(arg0),
                 B(LdaUndefined),
@@ -123,9 +117,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 5
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   37 S> */ B(LdaSmi), I8(1),
                 B(Star), R(arg1),
                 B(LdaUndefined),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveExpressions.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveExpressions.golden
index 4b0d05f8b0..daf96cdd44 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveExpressions.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveExpressions.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 5
+bytecode array length: 4
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   54 S> */ B(Return),
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   54 S> */ B(AddSmi), I8(3), U8(0),
@@ -48,9 +46,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(3),
@@ -70,9 +67,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   54 S> */ B(SubSmi), I8(3), U8(0),
@@ -89,9 +85,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(3),
@@ -111,9 +106,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   54 S> */ B(MulSmi), I8(3), U8(0),
@@ -130,9 +124,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   54 S> */ B(MulSmi), I8(3), U8(0),
@@ -149,9 +142,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   54 S> */ B(DivSmi), I8(3), U8(0),
@@ -168,9 +160,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(3),
@@ -190,9 +181,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   54 S> */ B(ModSmi), I8(3), U8(0),
@@ -209,9 +199,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(4),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(3),
@@ -231,9 +220,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseOrSmi), I8(2), U8(0),
@@ -250,9 +238,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseOrSmi), I8(2), U8(0),
@@ -269,9 +256,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseXorSmi), I8(2), U8(0),
@@ -288,9 +274,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseXorSmi), I8(2), U8(0),
@@ -307,9 +292,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseAndSmi), I8(2), U8(0),
@@ -326,9 +310,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   54 S> */ B(BitwiseAndSmi), I8(2), U8(0),
@@ -345,9 +328,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   55 S> */ B(ShiftLeftSmi), I8(3), U8(0),
@@ -364,9 +346,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(3),
@@ -386,9 +367,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   55 S> */ B(ShiftRightSmi), I8(3), U8(0),
@@ -405,9 +385,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(3),
@@ -427,9 +406,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   55 S> */ B(ShiftRightLogicalSmi), I8(3), U8(0),
@@ -446,9 +424,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(10),
                 B(Star), R(0),
   /*   46 S> */ B(LdaSmi), I8(3),
@@ -468,9 +445,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveReturnStatements.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveReturnStatements.golden
index e31ab85708..77f55145cc 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveReturnStatements.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrimitiveReturnStatements.golden
@@ -10,9 +10,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(LdaUndefined),
   /*   34 S> */ B(Return),
 ]
@@ -27,9 +26,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaUndefined),
   /*   41 S> */ B(Return),
 ]
@@ -44,9 +42,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaNull),
   /*   46 S> */ B(Return),
 ]
@@ -61,9 +58,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaTrue),
   /*   46 S> */ B(Return),
 ]
@@ -78,9 +74,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaFalse),
   /*   47 S> */ B(Return),
 ]
@@ -95,9 +90,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaZero),
   /*   43 S> */ B(Return),
 ]
@@ -112,9 +106,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(1),
   /*   44 S> */ B(Return),
 ]
@@ -129,9 +122,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(-1),
   /*   44 S> */ B(Return),
 ]
@@ -146,9 +138,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(127),
   /*   46 S> */ B(Return),
 ]
@@ -163,9 +154,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(-128),
   /*   46 S> */ B(Return),
 ]
@@ -180,9 +170,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(2),
   /*   45 S> */ B(Return),
 ]
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorAccess.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorAccess.golden
index ff4c255949..7ac886945c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorAccess.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorAccess.golden
@@ -24,14 +24,13 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 98
+bytecode array length: 97
 bytecodes: [
-  /*   67 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   67 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
   /*   76 S> */ B(LdaCurrentContextSlot), U8(2),
                 B(Star), R(4),
                 B(LdaCurrentContextSlot), U8(3),
@@ -78,15 +77,14 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   48 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   53 S> */ B(Wide), B(LdaSmi), I16(265),
+  /*   48 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   53 S> */ B(Wide), B(LdaSmi), I16(266),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -110,15 +108,14 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   41 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   46 S> */ B(Wide), B(LdaSmi), I16(264),
+  /*   41 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   46 S> */ B(Wide), B(LdaSmi), I16(265),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -142,15 +139,14 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   48 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   53 S> */ B(Wide), B(LdaSmi), I16(265),
+  /*   48 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   53 S> */ B(Wide), B(LdaSmi), I16(266),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -174,15 +170,14 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   41 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   46 S> */ B(Wide), B(LdaSmi), I16(264),
+  /*   41 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   46 S> */ B(Wide), B(LdaSmi), I16(265),
                 B(Star), R(4),
                 B(LdaConstant), U8(0),
                 B(Star), R(5),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorDeclaration.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorDeclaration.golden
index cf12be82ba..085e38d7db 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorDeclaration.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateAccessorDeclaration.golden
@@ -17,10 +17,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 65
+bytecode array length: 64
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaConstant), U8(2),
                 B(Star), R(3),
@@ -67,10 +66,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 62
+bytecode array length: 61
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaConstant), U8(2),
                 B(Star), R(3),
@@ -116,10 +114,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 62
+bytecode array length: 61
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaConstant), U8(2),
                 B(Star), R(3),
@@ -171,10 +168,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 127
+bytecode array length: 126
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaConstant), U8(2),
                 B(Star), R(4),
@@ -251,10 +247,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 113
+bytecode array length: 112
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(Star), R(6),
@@ -325,10 +320,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 113
+bytecode array length: 112
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(Star), R(6),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateClassFields.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateClassFields.golden
index 90ae0a6688..5e00600435 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateClassFields.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateClassFields.golden
@@ -24,10 +24,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 131
+bytecode array length: 130
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaConstant), U8(2),
                 B(Star), R(4),
@@ -130,10 +129,9 @@ snippet: "
 "
 frame size: 12
 parameter count: 1
-bytecode array length: 268
+bytecode array length: 267
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(3),
                 B(LdaConstant), U8(2),
                 B(Star), R(5),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodAccess.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodAccess.golden
index d413b43af8..cd5dd6f5a6 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodAccess.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodAccess.golden
@@ -19,14 +19,13 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 31
+bytecode array length: 30
 bytecodes: [
-  /*   44 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   44 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
   /*   49 S> */ B(LdaCurrentContextSlot), U8(3),
   /*   61 E> */ B(LdaKeyedProperty), R(this), U8(0),
                 B(LdaCurrentContextSlot), U8(2),
@@ -51,15 +50,14 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   44 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   49 S> */ B(Wide), B(LdaSmi), I16(263),
+  /*   44 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   49 S> */ B(Wide), B(LdaSmi), I16(264),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -84,15 +82,14 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   44 E> */ B(StackCheck),
                 B(LdaCurrentContextSlot), U8(3),
                 B(Star), R(1),
                 B(Mov), R(this), R(0),
                 B(Mov), R(context), R(2),
-                B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
-  /*   49 S> */ B(Wide), B(LdaSmi), I16(263),
+  /*   44 E> */ B(CallRuntime), U16(Runtime::kAddPrivateBrand), R(0), U8(3),
+  /*   49 S> */ B(Wide), B(LdaSmi), I16(264),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -117,10 +114,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 58
+bytecode array length: 57
 bytecodes: [
-  /*   44 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(1),
+  /*   44 E> */ B(CreateFunctionContext), U8(0), U8(1),
                 B(PushContext), R(0),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodDeclaration.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodDeclaration.golden
index ef7c245d46..9643de4f23 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodDeclaration.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PrivateMethodDeclaration.golden
@@ -16,10 +16,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 52
+bytecode array length: 51
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaConstant), U8(2),
                 B(Star), R(3),
@@ -64,10 +63,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 101
+bytecode array length: 100
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaConstant), U8(2),
                 B(Star), R(4),
@@ -133,10 +131,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 98
+bytecode array length: 97
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(Star), R(6),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyCall.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyCall.golden
index 9d55cd6cb8..2e067b6f53 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyCall.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyCall.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
                 B(Star), R(0),
   /*   25 E> */ B(CallProperty0), R(0), R(arg0), U8(2),
@@ -34,9 +33,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 4
-bytecode array length: 14
+bytecode array length: 13
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   31 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
                 B(Star), R(0),
   /*   31 E> */ B(CallProperty2), R(0), R(arg0), R(arg1), R(arg2), U8(2),
@@ -55,9 +53,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 3
-bytecode array length: 21
+bytecode array length: 20
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   28 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
                 B(Star), R(0),
                 B(Ldar), R(arg1),
@@ -210,9 +207,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 2
-bytecode array length: 543
+bytecode array length: 542
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   26 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   34 S> */ B(LdaNamedProperty), R(0), U8(0), U8(0),
@@ -490,9 +486,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 2
-bytecode array length: 51
+bytecode array length: 50
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreOneShot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreOneShot.golden
index e6eacf6fd6..6fd6116f0c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreOneShot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreOneShot.golden
@@ -22,9 +22,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 77
+bytecode array length: 76
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(41),
@@ -80,9 +79,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 120
+bytecode array length: 118
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(41),
@@ -97,8 +95,7 @@ bytecodes: [
                 B(Star), R(1),
                 B(LdaSmi), I8(5),
   /*   77 E> */ B(TestLessThan), R(1), U8(6),
-                B(JumpIfFalse), U8(83),
-  /*   63 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(82),
   /*   97 S> */ B(LdaGlobal), U8(1), U8(7),
                 B(Star), R(1),
   /*  106 E> */ B(LdaGlobal), U8(1), U8(7),
@@ -126,7 +123,7 @@ bytecodes: [
   /*   84 S> */ B(LdaGlobal), U8(2), U8(4),
                 B(Inc), U8(19),
   /*   84 E> */ B(StaGlobal), U8(2), U8(2),
-                B(JumpLoop), U8(90), I8(0),
+  /*   63 E> */ B(JumpLoop), U8(89), I8(0),
                 B(Ldar), R(0),
   /*  171 S> */ B(Return),
 ]
@@ -155,9 +152,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 109
+bytecode array length: 107
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(41),
@@ -170,8 +166,7 @@ bytecodes: [
                 B(Star), R(1),
                 B(LdaZero),
   /*   72 E> */ B(TestGreaterThan), R(1), U8(4),
-                B(JumpIfFalse), U8(77),
-  /*   63 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(76),
   /*   87 S> */ B(LdaGlobal), U8(1), U8(5),
                 B(Star), R(1),
   /*   97 E> */ B(LdaGlobal), U8(1), U8(5),
@@ -197,7 +192,7 @@ bytecodes: [
   /*  130 E> */ B(StaNamedProperty), R(1), U8(4), U8(15),
                 B(Mov), R(2), R(0),
                 B(Ldar), R(2),
-                B(JumpLoop), U8(83), I8(0),
+  /*   63 E> */ B(JumpLoop), U8(82), I8(0),
                 B(Ldar), R(0),
   /*  163 S> */ B(Return),
 ]
@@ -226,9 +221,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 81
+bytecode array length: 79
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(41),
@@ -239,7 +233,6 @@ bytecodes: [
   /*   65 E> */ B(StaGlobal), U8(2), U8(2),
                 B(LdaUndefined),
                 B(Star), R(0),
-  /*   77 E> */ B(StackCheck),
   /*   90 S> */ B(LdaGlobal), U8(1), U8(4),
                 B(Star), R(1),
   /*   99 E> */ B(LdaGlobal), U8(1), U8(4),
@@ -258,7 +251,7 @@ bytecodes: [
                 B(LdaSmi), I8(10),
   /*  133 E> */ B(TestLessThan), R(1), U8(15),
                 B(JumpIfFalse), U8(5),
-                B(JumpLoop), U8(50), I8(0),
+  /*   77 E> */ B(JumpLoop), U8(49), I8(0),
                 B(Ldar), R(0),
   /*  146 S> */ B(Return),
 ]
@@ -288,9 +281,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 75
+bytecode array length: 74
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(2),
                 B(LdaSmi), I8(41),
@@ -339,9 +331,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(3),
                 B(LdaSmi), I8(4),
@@ -366,9 +357,8 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 20
+bytecode array length: 19
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(LdaConstant), U8(0),
                 B(Star), R(3),
                 B(LdaSmi), I8(37),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreWithoutOneShot.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreWithoutOneShot.golden
index fe75e8a344..ef630cfa6f 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreWithoutOneShot.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoadStoreWithoutOneShot.golden
@@ -21,9 +21,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 71
+bytecode array length: 70
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
   /*    9 E> */ B(StaGlobal), U8(1), U8(1),
   /*   66 S> */ B(LdaGlobal), U8(1), U8(4),
@@ -76,9 +75,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 67
+bytecode array length: 66
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
   /*    7 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
   /*    9 E> */ B(StaGlobal), U8(1), U8(1),
   /*   65 S> */ B(LdaGlobal), U8(1), U8(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoads.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoads.golden
index 4b1a1c03a9..e28ded8006 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoads.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyLoads.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   25 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
   /*   30 S> */ B(Return),
 ]
@@ -32,9 +31,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   24 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
   /*   32 S> */ B(Return),
 ]
@@ -51,9 +49,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(LdaSmi), I8(100),
   /*   24 E> */ B(LdaKeyedProperty), R(arg0), U8(0),
   /*   30 S> */ B(Return),
@@ -70,9 +67,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(Ldar), R(arg1),
   /*   27 E> */ B(LdaKeyedProperty), R(arg0), U8(0),
   /*   31 S> */ B(Return),
@@ -89,9 +85,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   26 S> */ B(LdaNamedProperty), R(arg0), U8(0), U8(0),
                 B(Star), R(0),
   /*   32 S> */ B(LdaSmi), I8(-124),
@@ -242,9 +237,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 525
+bytecode array length: 524
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   26 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   34 S> */ B(LdaNamedProperty), R(0), U8(0), U8(0),
@@ -650,9 +644,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 3
-bytecode array length: 906
+bytecode array length: 905
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   30 S> */ B(Ldar), R(arg1),
   /*   35 E> */ B(LdaKeyedProperty), R(arg0), U8(0),
                 B(Star), R(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyStores.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyStores.golden
index 2bb062b707..32e4e31848 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyStores.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PropertyStores.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(LdaConstant), U8(0),
   /*   23 E> */ B(StaNamedProperty), R(arg0), U8(1), U8(0),
                 B(LdaUndefined),
@@ -35,9 +34,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(LdaConstant), U8(0),
   /*   25 E> */ B(StaNamedProperty), R(arg0), U8(1), U8(0),
                 B(LdaUndefined),
@@ -57,9 +55,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 2
-bytecode array length: 13
+bytecode array length: 12
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(LdaSmi), I8(100),
                 B(Star), R(1),
                 B(LdaConstant), U8(0),
@@ -80,9 +77,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   19 S> */ B(LdaConstant), U8(0),
   /*   24 E> */ B(StaKeyedProperty), R(arg0), R(arg1), U8(0),
                 B(LdaUndefined),
@@ -101,9 +97,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   16 S> */ B(LdaSmi), I8(-124),
   /*   26 E> */ B(LdaKeyedProperty), R(arg0), U8(0),
   /*   23 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(2),
@@ -123,9 +118,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   30 S> */ B(LdaConstant), U8(0),
   /*   37 E> */ B(StaNamedProperty), R(arg0), U8(1), U8(0),
                 B(LdaUndefined),
@@ -145,9 +139,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 9
+bytecode array length: 8
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   33 S> */ B(LdaConstant), U8(0),
   /*   38 E> */ B(StaKeyedProperty), R(arg0), R(arg1), U8(0),
                 B(LdaUndefined),
@@ -298,9 +291,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 534
+bytecode array length: 533
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   18 S> */ B(LdaSmi), I8(1),
   /*   25 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   40 S> */ B(CreateEmptyObjectLiteral),
@@ -712,9 +704,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 534
+bytecode array length: 533
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   33 S> */ B(LdaSmi), I8(1),
   /*   40 E> */ B(StaNamedProperty), R(arg0), U8(0), U8(0),
   /*   55 S> */ B(CreateEmptyObjectLiteral),
@@ -1123,9 +1114,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 781
+bytecode array length: 780
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   21 S> */ B(LdaSmi), I8(1),
   /*   26 E> */ B(StaKeyedProperty), R(arg0), R(arg1), U8(0),
   /*   33 S> */ B(LdaSmi), I8(1),
@@ -1530,9 +1520,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 3
-bytecode array length: 781
+bytecode array length: 780
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   37 S> */ B(LdaSmi), I8(1),
   /*   42 E> */ B(StaKeyedProperty), R(arg0), R(arg1), U8(0),
   /*   49 S> */ B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/PublicClassFields.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/PublicClassFields.golden
index ab5fcf5c4c..a841e05375 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/PublicClassFields.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/PublicClassFields.golden
@@ -23,10 +23,9 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 119
+bytecode array length: 118
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -122,10 +121,9 @@ snippet: "
 "
 frame size: 12
 parameter count: 1
-bytecode array length: 229
+bytecode array length: 228
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(3),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/RegExpLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/RegExpLiterals.golden
index 69f63eb8b4..8f43e97280 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/RegExpLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/RegExpLiterals.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateRegExpLiteral), U8(0), U8(0), U8(0),
   /*   48 S> */ B(Return),
 ]
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateRegExpLiteral), U8(0), U8(0), U8(2),
   /*   57 S> */ B(Return),
 ]
@@ -47,9 +45,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateRegExpLiteral), U8(0), U8(0), U8(0),
                 B(Star), R(1),
   /*   48 E> */ B(LdaNamedProperty), R(1), U8(1), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/RemoveRedundantLdar.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/RemoveRedundantLdar.golden
index 7896ffc3ce..22831a3ff3 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/RemoveRedundantLdar.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/RemoveRedundantLdar.golden
@@ -16,12 +16,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 26
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
-  /*   48 E> */ B(StackCheck),
   /*   64 S> */ B(Ldar), R(0),
   /*   76 E> */ B(Add), R(0), U8(0),
                 B(Star), R(0),
@@ -29,7 +27,7 @@ bytecodes: [
   /*   95 E> */ B(TestGreaterThan), R(0), U8(1),
                 B(JumpIfFalse), U8(4),
   /*  101 S> */ B(Jump), U8(5),
-                B(JumpLoop), U8(17), I8(0),
+  /*   48 E> */ B(JumpLoop), U8(16), I8(0),
   /*  110 S> */ B(Ldar), R(0),
   /*  122 S> */ B(Return),
 ]
@@ -49,12 +47,10 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
-  /*   48 E> */ B(StackCheck),
   /*   67 S> */ B(Add), R(0), U8(0),
                 B(Star), R(0),
   /*   77 S> */ B(LdaSmi), I8(10),
@@ -77,9 +73,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 11
+bytecode array length: 10
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   45 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   62 S> */ B(Add), R(0), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StandardForLoop.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StandardForLoop.golden
index 82a43ae36c..7d7a8d39b3 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StandardForLoop.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StandardForLoop.golden
@@ -15,20 +15,18 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 24
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   30 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   35 S> */ B(LdaSmi), I8(10),
   /*   35 E> */ B(TestLessThan), R(0), U8(0),
-                B(JumpIfFalse), U8(15),
-  /*   17 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(14),
   /*   56 S> */ B(Mov), R(0), R(1),
   /*   43 S> */ B(Ldar), R(1),
                 B(Inc), U8(1),
                 B(Star), R(0),
-                B(JumpLoop), U8(17), I8(0),
+  /*   17 E> */ B(JumpLoop), U8(16), I8(0),
                 B(LdaUndefined),
   /*   61 S> */ B(Return),
 ]
@@ -46,10 +44,9 @@ snippet: "
 "
 frame size: 15
 parameter count: 1
-bytecode array length: 165
+bytecode array length: 162
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
-                B(CreateFunctionContext), U8(0), U8(4),
+  /*   10 E> */ B(CreateFunctionContext), U8(0), U8(4),
                 B(PushContext), R(4),
                 B(Ldar), R(this),
                 B(StaCurrentContextSlot), U8(3),
@@ -67,8 +64,7 @@ bytecodes: [
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   59 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(2),
+  /*   59 E> */ B(CreateBlockContext), U8(2),
                 B(PushContext), R(6),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -92,11 +88,10 @@ bytecodes: [
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(6),
                 B(PopContext), R(6),
-                B(Jump), U8(77),
+                B(Jump), U8(76),
                 B(LdaSmi), I8(1),
                 B(TestEqual), R(2), U8(3),
-                B(JumpIfFalse), U8(54),
-  /*   17 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(53),
   /*   48 S> */ B(LdaLookupGlobalSlot), U8(3), U8(4), U8(3),
                 B(Star), R(7),
                 B(LdaConstant), U8(4),
@@ -117,14 +112,14 @@ bytecodes: [
                 B(Star), R(2),
                 B(LdaCurrentContextSlot), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(56), I8(1),
+  /*   17 E> */ B(JumpLoop), U8(55), I8(1),
                 B(LdaSmi), I8(1),
-  /*   59 E> */ B(TestEqual), R(2), U8(8),
+                B(TestEqual), R(2), U8(8),
                 B(JumpIfFalse), U8(6),
                 B(PopContext), R(6),
                 B(Jump), U8(7),
                 B(PopContext), R(6),
-                B(JumpLoop), U8(123), I8(0),
+                B(JumpLoop), U8(121), I8(0),
                 B(PopContext), R(5),
                 B(LdaUndefined),
   /*   61 S> */ B(Return),
@@ -148,16 +143,14 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 106
+bytecode array length: 103
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   30 S> */ B(LdaZero),
                 B(Star), R(3),
                 B(Star), R(0),
                 B(LdaSmi), I8(1),
                 B(Star), R(1),
-  /*   78 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   78 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(4),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -181,11 +174,10 @@ bytecodes: [
                 B(JumpIfFalse), U8(4),
                 B(Jump), U8(6),
                 B(PopContext), R(4),
-                B(Jump), U8(45),
+                B(Jump), U8(44),
                 B(LdaSmi), I8(1),
                 B(TestEqual), R(2), U8(3),
-                B(JumpIfFalse), U8(22),
-  /*   17 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(21),
   /*   48 S> */ B(CreateClosure), U8(1), U8(0), U8(2),
                 B(Star), R(5),
   /*   74 E> */ B(CallUndefinedReceiver0), R(5), U8(4),
@@ -193,14 +185,14 @@ bytecodes: [
                 B(Star), R(2),
                 B(LdaCurrentContextSlot), U8(2),
                 B(Star), R(0),
-                B(JumpLoop), U8(24), I8(1),
+  /*   17 E> */ B(JumpLoop), U8(23), I8(1),
                 B(LdaSmi), I8(1),
-  /*   78 E> */ B(TestEqual), R(2), U8(6),
+                B(TestEqual), R(2), U8(6),
                 B(JumpIfFalse), U8(6),
                 B(PopContext), R(4),
                 B(Jump), U8(7),
                 B(PopContext), R(4),
-                B(JumpLoop), U8(91), I8(0),
+                B(JumpLoop), U8(89), I8(0),
                 B(LdaUndefined),
   /*   80 S> */ B(Return),
 ]
@@ -220,9 +212,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 44
+bytecode array length: 42
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   37 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(Star), R(3),
   /*   28 S> */ B(LdaNamedProperty), R(3), U8(1), U8(1),
@@ -231,15 +222,14 @@ bytecodes: [
                 B(Star), R(1),
   /*   55 S> */ B(LdaZero),
   /*   55 E> */ B(TestGreaterThan), R(1), U8(5),
-                B(JumpIfFalse), U8(19),
-  /*   17 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(18),
   /*   75 S> */ B(Ldar), R(1),
   /*   77 E> */ B(Add), R(0), U8(6),
                 B(Star), R(2),
   /*   62 S> */ B(Ldar), R(1),
                 B(Dec), U8(7),
                 B(Star), R(1),
-                B(JumpLoop), U8(20), I8(0),
+  /*   17 E> */ B(JumpLoop), U8(19), I8(0),
                 B(LdaUndefined),
   /*   84 S> */ B(Return),
 ]
@@ -260,13 +250,12 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 67
+bytecode array length: 65
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(3),
                 B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(3), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(3), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(3),
@@ -281,13 +270,12 @@ bytecodes: [
                 B(Star), R(1),
   /*   36 S> */ B(LdaSmi), I8(10),
   /*   36 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(15),
-  /*   18 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(14),
   /*   57 S> */ B(Mov), R(1), R(2),
   /*   44 S> */ B(Ldar), R(2),
                 B(Inc), U8(1),
                 B(Star), R(1),
-                B(JumpLoop), U8(17), I8(0),
+  /*   18 E> */ B(JumpLoop), U8(16), I8(0),
                 B(LdaUndefined),
   /*   62 S> */ B(Return),
 ]
@@ -308,13 +296,12 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 99
+bytecode array length: 97
 bytecodes: [
-  /*   11 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(2),
                 B(Mov), R(closure), R(2),
                 B(Mov), R(this), R(3),
-                B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
+  /*   11 E> */ B(InvokeIntrinsic), U8(Runtime::k_CreateJSGeneratorObject), R(2), U8(2),
                 B(Star), R(0),
   /*   11 E> */ B(SuspendGenerator), R(0), R(0), U8(2), U8(0),
                 B(ResumeGenerator), R(0), R(0), U8(2),
@@ -329,8 +316,7 @@ bytecodes: [
                 B(Star), R(1),
   /*   36 S> */ B(LdaSmi), I8(10),
   /*   36 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(47),
-  /*   18 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(46),
   /*   47 S> */ B(LdaFalse),
                 B(Star), R(3),
                 B(Mov), R(1), R(2),
@@ -347,13 +333,13 @@ bytecodes: [
   /*   44 S> */ B(Ldar), R(1),
                 B(Inc), U8(1),
                 B(Star), R(1),
-                B(JumpLoop), U8(49), I8(0),
+  /*   18 E> */ B(JumpLoop), U8(48), I8(0),
                 B(LdaUndefined),
   /*   56 S> */ B(Return),
 ]
 constant pool: [
   Smi [21],
-  Smi [67],
+  Smi [66],
   Smi [10],
   Smi [7],
   Smi [10],
@@ -371,31 +357,29 @@ snippet: "
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 81
+bytecode array length: 79
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(Mov), R(closure), R(3),
                 B(Mov), R(this), R(4),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(3), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
   /*   36 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   41 S> */ B(LdaSmi), I8(10),
   /*   41 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(15),
-  /*   23 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(14),
   /*   62 S> */ B(Mov), R(1), R(2),
   /*   49 S> */ B(Ldar), R(2),
                 B(Inc), U8(1),
                 B(Star), R(1),
-                B(JumpLoop), U8(17), I8(0),
+  /*   23 E> */ B(JumpLoop), U8(16), I8(0),
                 B(LdaUndefined),
                 B(Star), R(5),
                 B(LdaFalse),
                 B(Star), R(6),
                 B(Mov), R(0), R(4),
-  /*   49 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(4), U8(3),
   /*   67 S> */ B(Return),
                 B(Star), R(4),
                 B(CreateCatchContext), R(4), U8(0),
@@ -416,7 +400,7 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [16, 53, 53],
+  [15, 51, 51],
 ]
 
 ---
@@ -428,21 +412,19 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 117
+bytecode array length: 115
 bytecodes: [
-  /*   16 E> */ B(StackCheck),
                 B(SwitchOnGeneratorState), R(0), U8(0), U8(1),
                 B(Mov), R(closure), R(2),
                 B(Mov), R(this), R(3),
-                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
+  /*   16 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionEnter), R(2), U8(2),
                 B(Star), R(0),
                 B(Mov), R(context), R(2),
   /*   36 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   41 S> */ B(LdaSmi), I8(10),
   /*   41 E> */ B(TestLessThan), R(1), U8(0),
-                B(JumpIfFalse), U8(47),
-  /*   23 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(46),
   /*   52 S> */ B(Mov), R(0), R(3),
                 B(Mov), R(1), R(4),
                 B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionAwaitUncaught), R(3), U8(2),
@@ -459,13 +441,13 @@ bytecodes: [
   /*   49 S> */ B(Ldar), R(1),
                 B(Inc), U8(1),
                 B(Star), R(1),
-                B(JumpLoop), U8(49), I8(0),
+  /*   23 E> */ B(JumpLoop), U8(48), I8(0),
                 B(LdaUndefined),
                 B(Star), R(4),
                 B(LdaTrue),
                 B(Star), R(5),
                 B(Mov), R(0), R(3),
-  /*   49 E> */ B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(3), U8(3),
+                B(InvokeIntrinsic), U8(Runtime::k_AsyncFunctionResolve), R(3), U8(3),
   /*   61 S> */ B(Return),
                 B(Star), R(3),
                 B(CreateCatchContext), R(3), U8(1),
@@ -483,10 +465,10 @@ bytecodes: [
   /*   61 S> */ B(Return),
 ]
 constant pool: [
-  Smi [45],
+  Smi [44],
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [20, 89, 89],
+  [19, 87, 87],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticClassFields.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticClassFields.golden
index e456906b2b..2b7639a885 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticClassFields.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticClassFields.golden
@@ -27,10 +27,9 @@ snippet: "
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 185
+bytecode array length: 184
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(2),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
@@ -162,10 +161,9 @@ snippet: "
 "
 frame size: 12
 parameter count: 1
-bytecode array length: 334
+bytecode array length: 333
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(3),
                 B(LdaTheHole),
                 B(StaCurrentContextSlot), U8(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodAccess.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodAccess.golden
index 70628162df..352ec83961 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodAccess.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodAccess.golden
@@ -19,14 +19,13 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   51 E> */ B(StackCheck),
   /*   56 S> */ B(LdaCurrentContextSlot), U8(3),
                 B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(1),
                 B(JumpIfTrue), U8(18),
-                B(Wide), B(LdaSmi), I16(261),
+                B(Wide), B(LdaSmi), I16(262),
                 B(Star), R(2),
                 B(LdaConstant), U8(0),
                 B(Star), R(3),
@@ -55,10 +54,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   51 E> */ B(StackCheck),
-  /*   56 S> */ B(Wide), B(LdaSmi), I16(263),
+  /*   56 S> */ B(Wide), B(LdaSmi), I16(264),
                 B(Star), R(0),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -83,10 +81,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   51 E> */ B(StackCheck),
-  /*   56 S> */ B(Wide), B(LdaSmi), I16(263),
+  /*   56 S> */ B(Wide), B(LdaSmi), I16(264),
                 B(Star), R(0),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -117,16 +114,15 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 143
+bytecode array length: 142
 bytecodes: [
-  /*   81 E> */ B(StackCheck),
   /*   90 S> */ B(LdaCurrentContextSlot), U8(2),
                 B(Star), R(1),
                 B(LdaCurrentContextSlot), U8(3),
   /*   94 E> */ B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(18),
-                B(Wide), B(LdaSmi), I16(261),
+                B(Wide), B(LdaSmi), I16(262),
                 B(Star), R(2),
                 B(LdaConstant), U8(0),
                 B(Star), R(3),
@@ -148,7 +144,7 @@ bytecodes: [
   /*  109 E> */ B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(1),
                 B(JumpIfTrue), U8(18),
-                B(Wide), B(LdaSmi), I16(262),
+                B(Wide), B(LdaSmi), I16(263),
                 B(Star), R(3),
                 B(LdaConstant), U8(0),
                 B(Star), R(4),
@@ -163,7 +159,7 @@ bytecodes: [
   /*  133 E> */ B(TestReferenceEqual), R(this),
                 B(Mov), R(this), R(0),
                 B(JumpIfTrue), U8(18),
-                B(Wide), B(LdaSmi), I16(261),
+                B(Wide), B(LdaSmi), I16(262),
                 B(Star), R(2),
                 B(LdaConstant), U8(0),
                 B(Star), R(3),
@@ -191,10 +187,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   55 E> */ B(StackCheck),
-  /*   60 S> */ B(Wide), B(LdaSmi), I16(265),
+  /*   60 S> */ B(Wide), B(LdaSmi), I16(266),
                 B(Star), R(0),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -218,10 +213,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   48 E> */ B(StackCheck),
-  /*   53 S> */ B(Wide), B(LdaSmi), I16(264),
+  /*   53 S> */ B(Wide), B(LdaSmi), I16(265),
                 B(Star), R(0),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -245,10 +239,9 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   55 E> */ B(StackCheck),
-  /*   60 S> */ B(Wide), B(LdaSmi), I16(265),
+  /*   60 S> */ B(Wide), B(LdaSmi), I16(266),
                 B(Star), R(0),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
@@ -272,10 +265,9 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   41 E> */ B(StackCheck),
-  /*   46 S> */ B(Wide), B(LdaSmi), I16(264),
+  /*   46 S> */ B(Wide), B(LdaSmi), I16(265),
                 B(Star), R(1),
                 B(LdaConstant), U8(0),
                 B(Star), R(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodDeclaration.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodDeclaration.golden
index b074e54243..1af4690aa5 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodDeclaration.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StaticPrivateMethodDeclaration.golden
@@ -16,10 +16,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 41
+bytecode array length: 40
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -56,10 +55,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 51
+bytecode array length: 50
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -100,10 +98,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 51
+bytecode array length: 50
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -145,10 +142,9 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 54
+bytecode array length: 53
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaTheHole),
                 B(Star), R(5),
@@ -191,10 +187,9 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 58
+bytecode array length: 57
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateBlockContext), U8(0),
+  /*   30 E> */ B(CreateBlockContext), U8(0),
                 B(PushContext), R(1),
                 B(LdaConstant), U8(2),
                 B(Star), R(3),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StoreGlobal.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StoreGlobal.golden
index eed4f0467c..0a2c2995e6 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StoreGlobal.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StoreGlobal.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   21 E> */ B(StackCheck),
   /*   26 S> */ B(LdaSmi), I8(2),
   /*   28 E> */ B(StaGlobal), U8(0), U8(0),
                 B(LdaUndefined),
@@ -35,9 +34,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 2
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   26 E> */ B(StackCheck),
   /*   32 S> */ B(Ldar), R(arg0),
   /*   34 E> */ B(StaGlobal), U8(0), U8(0),
                 B(LdaUndefined),
@@ -57,9 +55,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   35 E> */ B(StackCheck),
   /*   40 S> */ B(LdaSmi), I8(2),
   /*   42 E> */ B(StaGlobal), U8(0), U8(0),
                 B(LdaUndefined),
@@ -79,9 +76,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
   /*   22 S> */ B(LdaSmi), I8(2),
   /*   24 E> */ B(StaGlobal), U8(0), U8(0),
                 B(LdaUndefined),
@@ -232,9 +228,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 526
+bytecode array length: 525
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
   /*   33 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   41 S> */ B(LdaNamedProperty), R(0), U8(0), U8(0),
@@ -644,9 +639,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 2
-bytecode array length: 526
+bytecode array length: 525
 bytecodes: [
-  /*   17 E> */ B(StackCheck),
   /*   49 S> */ B(CreateEmptyObjectLiteral),
                 B(Star), R(0),
   /*   57 S> */ B(LdaNamedProperty), R(0), U8(0), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConcat.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConcat.golden
index 3fa52040a8..9e94fe593d 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConcat.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConcat.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -41,9 +40,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 26
+bytecode array length: 25
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -71,9 +69,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 21
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -99,9 +96,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 43
+bytecode array length: 42
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -138,9 +134,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 29
+bytecode array length: 28
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -170,10 +165,9 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 42
+bytecode array length: 41
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateClosure), U8(0), U8(0), U8(2),
+  /*   30 E> */ B(CreateClosure), U8(0), U8(0), U8(2),
                 B(Star), R(2),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConstants.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConstants.golden
index 0f4b595c8e..385c3089c1 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConstants.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/StringConstants.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaConstant), U8(0),
   /*   60 S> */ B(Return),
 ]
@@ -29,9 +28,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   58 S> */ B(LdaConstant), U8(1),
@@ -50,9 +48,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(0),
   /*   57 S> */ B(LdaConstant), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/SuperCallAndSpread.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/SuperCallAndSpread.golden
index 2fd27fcce1..4124d91274 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/SuperCallAndSpread.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/SuperCallAndSpread.golden
@@ -19,10 +19,9 @@ snippet: "
 "
 frame size: 5
 parameter count: 1
-bytecode array length: 19
+bytecode array length: 18
 bytecodes: [
-  /*   93 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*   93 E> */ B(CreateRestParameter),
                 B(Star), R(2),
                 B(Mov), R(closure), R(1),
   /*   93 S> */ B(Ldar), R(1),
@@ -51,10 +50,9 @@ snippet: "
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 40
+bytecode array length: 39
 bytecodes: [
-  /*  128 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*  128 E> */ B(CreateRestParameter),
                 B(Star), R(3),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(3), R(2),
@@ -93,10 +91,9 @@ snippet: "
 "
 frame size: 11
 parameter count: 1
-bytecode array length: 119
+bytecode array length: 118
 bytecodes: [
-  /*  128 E> */ B(StackCheck),
-                B(CreateRestParameter),
+  /*  128 E> */ B(CreateRestParameter),
                 B(Star), R(3),
                 B(Mov), R(closure), R(1),
                 B(Mov), R(3), R(2),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Switch.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Switch.golden
index ca596e7a5e..5b12e3fc79 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Switch.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Switch.golden
@@ -15,9 +15,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 32
+bytecode array length: 31
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
@@ -50,9 +49,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 38
+bytecode array length: 37
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
@@ -87,9 +85,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
@@ -124,9 +121,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 36
+bytecode array length: 35
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(2),
@@ -161,9 +157,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 44
+bytecode array length: 43
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(TypeOf),
@@ -202,9 +197,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 30
+bytecode array length: 29
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(TypeOf),
@@ -303,9 +297,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 290
+bytecode array length: 289
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
@@ -472,9 +465,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 58
+bytecode array length: 57
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(LdaSmi), I8(1),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/TemplateLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/TemplateLiterals.golden
index c85f155947..b7821fa66c 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/TemplateLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/TemplateLiterals.golden
@@ -13,9 +13,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 27
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -45,9 +44,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 27
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -77,9 +75,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 28
+bytecode array length: 27
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -109,9 +106,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 50
+bytecode array length: 49
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -153,9 +149,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 35
+bytecode array length: 34
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   53 S> */ B(LdaSmi), I8(2),
@@ -189,10 +184,9 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 45
+bytecode array length: 44
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
-                B(CreateClosure), U8(0), U8(0), U8(2),
+  /*   30 E> */ B(CreateClosure), U8(0), U8(0), U8(2),
                 B(Star), R(2),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/ThisFunction.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/ThisFunction.golden
index 6c65fda872..557d0b4487 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/ThisFunction.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/ThisFunction.golden
@@ -14,9 +14,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 3
+bytecode array length: 2
 bytecodes: [
-  /*   21 E> */ B(StackCheck),
                 B(LdaUndefined),
   /*   25 S> */ B(Return),
 ]
@@ -33,9 +32,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   21 E> */ B(StackCheck),
                 B(Mov), R(closure), R(0),
   /*   26 S> */ B(Ldar), R(0),
   /*   35 S> */ B(Return),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Throw.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Throw.golden
index 73e203a60b..35926e7711 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Throw.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Throw.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaSmi), I8(1),
   /*   34 E> */ B(Throw),
 ]
@@ -28,9 +27,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 4
+bytecode array length: 3
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(LdaConstant), U8(0),
   /*   34 E> */ B(Throw),
 ]
@@ -46,9 +44,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 12
+bytecode array length: 11
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(5),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/TopLevelObjectLiterals.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/TopLevelObjectLiterals.golden
index c3e04111aa..f080925637 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/TopLevelObjectLiterals.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/TopLevelObjectLiterals.golden
@@ -12,13 +12,12 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 34
+bytecode array length: 33
 bytecodes: [
-  /*    0 E> */ B(StackCheck),
                 B(LdaConstant), U8(0),
                 B(Star), R(1),
                 B(Mov), R(closure), R(2),
-                B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
+  /*    0 E> */ B(CallRuntime), U16(Runtime::kDeclareGlobals), R(1), U8(2),
   /*    8 S> */ B(CreateObjectLiteral), U8(1), U8(0), U8(41),
                 B(Star), R(1),
   /*   16 E> */ B(CreateClosure), U8(2), U8(0), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/TryCatch.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/TryCatch.golden
index ec70270dae..5a299760ab 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/TryCatch.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/TryCatch.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 23
+bytecode array length: 22
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(Mov), R(context), R(0),
   /*   40 S> */ B(LdaSmi), I8(1),
   /*   49 S> */ B(Return),
@@ -31,7 +30,7 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [4, 7, 7],
+  [3, 6, 6],
 ]
 
 ---
@@ -42,9 +41,8 @@ snippet: "
 "
 frame size: 3
 parameter count: 1
-bytecode array length: 55
+bytecode array length: 54
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(Mov), R(context), R(1),
   /*   47 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
@@ -79,7 +77,7 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [4, 8, 10],
-  [28, 32, 34],
+  [3, 7, 9],
+  [27, 31, 33],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/TryFinally.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/TryFinally.golden
index 22d4e0c154..d06342c1b8 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/TryFinally.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/TryFinally.golden
@@ -12,9 +12,8 @@ snippet: "
 "
 frame size: 4
 parameter count: 1
-bytecode array length: 46
+bytecode array length: 45
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
@@ -45,7 +44,7 @@ bytecodes: [
 constant pool: [
 ]
 handlers: [
-  [8, 12, 20],
+  [7, 11, 19],
 ]
 
 ---
@@ -55,9 +54,8 @@ snippet: "
 "
 frame size: 6
 parameter count: 1
-bytecode array length: 70
+bytecode array length: 69
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
                 B(Mov), R(context), R(3),
@@ -101,8 +99,8 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [8, 36, 44],
-  [11, 15, 17],
+  [7, 35, 43],
+  [10, 14, 16],
 ]
 
 ---
@@ -113,9 +111,8 @@ snippet: "
 "
 frame size: 7
 parameter count: 1
-bytecode array length: 90
+bytecode array length: 89
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
                 B(Mov), R(context), R(3),
                 B(Mov), R(context), R(4),
                 B(Mov), R(context), R(5),
@@ -170,8 +167,8 @@ constant pool: [
   SCOPE_INFO_TYPE,
 ]
 handlers: [
-  [4, 56, 64],
-  [7, 35, 37],
-  [10, 14, 16],
+  [3, 55, 63],
+  [6, 34, 36],
+  [9, 13, 15],
 ]
 
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/Typeof.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/Typeof.golden
index bd73b4acdb..ea335954e0 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/Typeof.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/Typeof.golden
@@ -16,9 +16,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 7
+bytecode array length: 6
 bytecodes: [
-  /*   10 E> */ B(StackCheck),
   /*   24 S> */ B(LdaSmi), I8(13),
                 B(Star), R(0),
   /*   29 S> */ B(TypeOf),
@@ -39,9 +38,8 @@ snippet: "
 "
 frame size: 0
 parameter count: 1
-bytecode array length: 6
+bytecode array length: 5
 bytecodes: [
-  /*   22 E> */ B(StackCheck),
   /*   28 S> */ B(LdaGlobalInsideTypeof), U8(0), U8(0),
                 B(TypeOf),
   /*   45 S> */ B(Return),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/UnaryOperators.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/UnaryOperators.golden
index b8b4c4bde8..b564000c3b 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/UnaryOperators.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/UnaryOperators.golden
@@ -15,19 +15,17 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 25
+bytecode array length: 23
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   54 S> */ B(LdaSmi), I8(10),
   /*   54 E> */ B(TestEqual), R(0), U8(0),
-                B(JumpIfTrue), U8(13),
-  /*   45 E> */ B(StackCheck),
+                B(JumpIfTrue), U8(12),
   /*   65 S> */ B(Ldar), R(0),
   /*   71 E> */ B(AddSmi), I8(10), U8(1),
                 B(Star), R(0),
-                B(JumpLoop), U8(15), I8(0),
+  /*   45 E> */ B(JumpLoop), U8(14), I8(0),
   /*   79 S> */ B(Ldar), R(0),
   /*   88 S> */ B(Return),
 ]
@@ -46,19 +44,17 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 22
+bytecode array length: 20
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaFalse),
                 B(Star), R(0),
-  /*   49 E> */ B(StackCheck),
   /*   56 S> */ B(Ldar), R(0),
                 B(ToBooleanLogicalNot),
                 B(Star), R(0),
   /*   74 S> */ B(LdaFalse),
   /*   74 E> */ B(TestEqual), R(0), U8(0),
                 B(JumpIfFalse), U8(5),
-                B(JumpLoop), U8(12), I8(0),
+  /*   49 E> */ B(JumpLoop), U8(11), I8(0),
   /*   85 S> */ B(Ldar), R(0),
   /*   94 S> */ B(Return),
 ]
@@ -74,9 +70,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 10
+bytecode array length: 9
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(101),
                 B(Star), R(0),
   /*   61 S> */ B(MulSmi), I8(3), U8(0),
@@ -96,9 +91,8 @@ snippet: "
 "
 frame size: 2
 parameter count: 1
-bytecode array length: 17
+bytecode array length: 16
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(Wide), B(LdaSmi), I16(1234),
                 B(Star), R(0),
   /*   64 S> */ B(Mul), R(0), U8(1),
@@ -119,9 +113,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(13),
                 B(Star), R(0),
   /*   53 S> */ B(BitwiseNot), U8(0),
@@ -139,9 +132,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(13),
                 B(Star), R(0),
   /*   53 S> */ B(ToNumber), U8(0),
@@ -159,9 +151,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 8
+bytecode array length: 7
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaSmi), I8(13),
                 B(Star), R(0),
   /*   53 S> */ B(Negate), U8(0),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/WideRegisters.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/WideRegisters.golden
index 066d6e9f03..afbe8e89a4 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/WideRegisters.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/WideRegisters.golden
@@ -169,9 +169,8 @@ snippet: "
 "
 frame size: 157
 parameter count: 1
-bytecode array length: 547
+bytecode array length: 546
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -659,9 +658,8 @@ snippet: "
 "
 frame size: 157
 parameter count: 1
-bytecode array length: 549
+bytecode array length: 548
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -1149,9 +1147,8 @@ snippet: "
 "
 frame size: 157
 parameter count: 1
-bytecode array length: 555
+bytecode array length: 554
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -1645,9 +1642,8 @@ snippet: "
 "
 frame size: 157
 parameter count: 1
-bytecode array length: 576
+bytecode array length: 575
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -2147,9 +2143,8 @@ snippet: "
 "
 frame size: 158
 parameter count: 1
-bytecode array length: 593
+bytecode array length: 591
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -2472,8 +2467,7 @@ bytecodes: [
                 B(Wide), B(Star), R16(128),
   /* 2166 S> */ B(LdaSmi), I8(64),
   /* 2166 E> */ B(Wide), B(TestLessThan), R16(128), U16(0),
-                B(JumpIfFalse), U8(31),
-  /* 2146 E> */ B(StackCheck),
+                B(JumpIfFalse), U8(30),
   /* 2183 S> */ B(Wide), B(Ldar), R16(128),
   /* 2189 E> */ B(Add), R(1), U8(1),
                 B(Wide), B(Mov), R16(1), R16(157),
@@ -2481,7 +2475,7 @@ bytecodes: [
   /* 2176 S> */ B(Wide), B(Ldar), R16(128),
                 B(Inc), U8(2),
                 B(Wide), B(Star), R16(128),
-                B(JumpLoop), U8(36), I8(0),
+  /* 2146 E> */ B(JumpLoop), U8(35), I8(0),
   /* 2195 S> */ B(Wide), B(Ldar), R16(128),
   /* 2207 S> */ B(Return),
 ]
@@ -2655,9 +2649,8 @@ snippet: "
 "
 frame size: 163
 parameter count: 1
-bytecode array length: 624
+bytecode array length: 622
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
@@ -2977,25 +2970,24 @@ bytecodes: [
   /* 2146 S> */ B(LdaZero),
                 B(Star), R(1),
   /* 2162 S> */ B(Ldar), R(0),
-                B(JumpIfUndefinedOrNull), U8(72),
+                B(JumpIfUndefinedOrNull), U8(71),
                 B(Wide), B(ToObject), R16(157),
                 B(Wide), B(ForInEnumerate), R16(157),
                 B(Wide), B(ForInPrepare), R16(158), U16(0),
                 B(LdaZero),
                 B(Wide), B(Star), R16(161),
   /* 2154 S> */ B(Wide), B(ForInContinue), R16(161), R16(160),
-                B(JumpIfFalse), U8(45),
+                B(JumpIfFalse), U8(44),
                 B(Wide), B(ForInNext), R16(157), R16(161), R16(158), U16(0),
-                B(JumpIfUndefined), U8(22),
+                B(JumpIfUndefined), U8(21),
                 B(Wide), B(Star), R16(128),
-  /* 2149 E> */ B(StackCheck),
   /* 2169 S> */ B(Wide), B(Ldar), R16(128),
   /* 2175 E> */ B(Add), R(1), U8(1),
                 B(Wide), B(Mov), R16(1), R16(162),
                 B(Star), R(1),
   /* 2172 E> */ B(Wide), B(ForInStep), R16(161),
                 B(Wide), B(Star), R16(161),
-                B(JumpLoop), U8(48), I8(0),
+  /* 2149 E> */ B(JumpLoop), U8(47), I8(0),
   /* 2181 S> */ B(Ldar), R(1),
   /* 2191 S> */ B(Return),
 ]
@@ -3170,9 +3162,8 @@ snippet: "
 "
 frame size: 159
 parameter count: 1
-bytecode array length: 590
+bytecode array length: 589
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   43 S> */ B(LdaZero),
                 B(Star), R(0),
   /*   55 S> */ B(LdaZero),
diff --git a/deps/v8/test/cctest/interpreter/bytecode_expectations/WithStatement.golden b/deps/v8/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
index 0b44c07300..0ffcdab0da 100644
--- a/deps/v8/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
+++ b/deps/v8/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
@@ -11,9 +11,8 @@ snippet: "
 "
 frame size: 1
 parameter count: 1
-bytecode array length: 15
+bytecode array length: 14
 bytecodes: [
-  /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(41),
                 B(ToObject), R(0),
                 B(CreateWithContext), R(0), U8(1),
diff --git a/deps/v8/test/cctest/interpreter/interpreter-tester.h b/deps/v8/test/cctest/interpreter/interpreter-tester.h
index fbc2666c10..64c9a90ca4 100644
--- a/deps/v8/test/cctest/interpreter/interpreter-tester.h
+++ b/deps/v8/test/cctest/interpreter/interpreter-tester.h
@@ -20,34 +20,54 @@ namespace v8 {
 namespace internal {
 namespace interpreter {
 
-MaybeHandle<Object> CallInterpreter(Isolate* isolate,
-                                    Handle<JSFunction> function);
 template <class... A>
 static MaybeHandle<Object> CallInterpreter(Isolate* isolate,
                                            Handle<JSFunction> function,
-                                           A... args) {
-  Handle<Object> argv[] = {args...};
-  return Execution::Call(isolate, function,
-                         isolate->factory()->undefined_value(), sizeof...(args),
-                         argv);
+                                           Handle<Object> receiver, A... args) {
+  // Pad the array with an empty handle to ensure that argv size is at least 1.
+  // It avoids MSVC error C2466.
+  Handle<Object> argv[] = {args..., Handle<Object>()};
+  return Execution::Call(isolate, function, receiver, sizeof...(args), argv);
 }
 
 template <class... A>
 class InterpreterCallable {
  public:
+  virtual ~InterpreterCallable() = default;
+
+  FeedbackVector vector() const { return function_->feedback_vector(); }
+
+ protected:
   InterpreterCallable(Isolate* isolate, Handle<JSFunction> function)
       : isolate_(isolate), function_(function) {}
-  virtual ~InterpreterCallable() = default;
+
+  Isolate* isolate_;
+  Handle<JSFunction> function_;
+};
+
+template <class... A>
+class InterpreterCallableUndefinedReceiver : public InterpreterCallable<A...> {
+ public:
+  InterpreterCallableUndefinedReceiver(Isolate* isolate,
+                                       Handle<JSFunction> function)
+      : InterpreterCallable<A...>(isolate, function) {}
 
   MaybeHandle<Object> operator()(A... args) {
-    return CallInterpreter(isolate_, function_, args...);
+    return CallInterpreter(this->isolate_, this->function_,
+                           this->isolate_->factory()->undefined_value(),
+                           args...);
   }
+};
 
-  FeedbackVector vector() const { return function_->feedback_vector(); }
+template <class... A>
+class InterpreterCallableWithReceiver : public InterpreterCallable<A...> {
+ public:
+  InterpreterCallableWithReceiver(Isolate* isolate, Handle<JSFunction> function)
+      : InterpreterCallable<A...>(isolate, function) {}
 
- private:
-  Isolate* isolate_;
-  Handle<JSFunction> function_;
+  MaybeHandle<Object> operator()(Handle<Object> receiver, A... args) {
+    return CallInterpreter(this->isolate_, this->function_, receiver, args...);
+  }
 };
 
 class InterpreterTester {
@@ -68,8 +88,15 @@ class InterpreterTester {
   virtual ~InterpreterTester();
 
   template <class... A>
-  InterpreterCallable<A...> GetCallable() {
-    return InterpreterCallable<A...>(isolate_, GetBytecodeFunction<A...>());
+  InterpreterCallableUndefinedReceiver<A...> GetCallable() {
+    return InterpreterCallableUndefinedReceiver<A...>(
+        isolate_, GetBytecodeFunction<A...>());
+  }
+
+  template <class... A>
+  InterpreterCallableWithReceiver<A...> GetCallableWithReceiver() {
+    return InterpreterCallableWithReceiver<A...>(isolate_,
+                                                 GetBytecodeFunction<A...>());
   }
 
   Local<Message> CheckThrowsReturnMessage();
diff --git a/deps/v8/test/cctest/interpreter/test-interpreter-intrinsics.cc b/deps/v8/test/cctest/interpreter/test-interpreter-intrinsics.cc
index 3e1c006f20..6889747e17 100644
--- a/deps/v8/test/cctest/interpreter/test-interpreter-intrinsics.cc
+++ b/deps/v8/test/cctest/interpreter/test-interpreter-intrinsics.cc
@@ -28,9 +28,23 @@ class InvokeIntrinsicHelper {
   template <class... A>
   Handle<Object> Invoke(A... args) {
     CHECK(IntrinsicsHelper::IsSupported(function_id_));
-    BytecodeArrayBuilder builder(zone_, sizeof...(args), 0, nullptr);
+    int parameter_count = sizeof...(args);
+#ifdef V8_REVERSE_JSARGS
+    // Move the parameter to locals, since the order of the
+    // arguments in the stack is reversed.
+    BytecodeArrayBuilder builder(zone_, parameter_count + 1, parameter_count,
+                                 nullptr);
+    for (int i = 0; i < parameter_count; i++) {
+      builder.MoveRegister(builder.Parameter(i), builder.Local(i));
+    }
+    RegisterList reg_list =
+        InterpreterTester::NewRegisterList(0, parameter_count);
+#else
+    // Add the receiver in the parameter count.
+    BytecodeArrayBuilder builder(zone_, parameter_count + 1, 0, nullptr);
     RegisterList reg_list = InterpreterTester::NewRegisterList(
-        builder.Receiver().index(), sizeof...(args));
+        builder.Parameter(0).index(), parameter_count);
+#endif
     builder.CallRuntime(function_id_, reg_list).Return();
     InterpreterTester tester(isolate_, builder.ToBytecodeArray(isolate_));
     auto callable = tester.GetCallable<A...>();
diff --git a/deps/v8/test/cctest/interpreter/test-interpreter.cc b/deps/v8/test/cctest/interpreter/test-interpreter.cc
index 8f687fdc8b..33daf581c7 100644
--- a/deps/v8/test/cctest/interpreter/test-interpreter.cc
+++ b/deps/v8/test/cctest/interpreter/test-interpreter.cc
@@ -170,7 +170,7 @@ TEST(InterpreterLoadLiteral) {
 
     builder.LoadLiteral(-2.1e19).Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array);
@@ -189,14 +189,13 @@ TEST(InterpreterLoadLiteral) {
     const AstRawString* raw_string = ast_factory.GetOneByteString("String");
     builder.LoadLiteral(raw_string).Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array);
     auto callable = tester.GetCallable<>();
     Handle<Object> return_val = callable().ToHandleChecked();
-    CHECK(i::String::cast(*return_val)
-              .Equals(*raw_string->string().get<Factory>()));
+    CHECK(i::String::cast(*return_val).Equals(*raw_string->string()));
   }
 }
 
@@ -535,7 +534,7 @@ TEST(InterpreterStringAdd) {
     builder.LoadLiteral(test_cases[i].lhs).StoreAccumulatorInRegister(reg);
     LoadLiteralForTest(&builder, test_cases[i].rhs);
     builder.BinaryOperation(Token::Value::ADD, reg, GetIndex(slot)).Return();
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
@@ -551,7 +550,7 @@ TEST(InterpreterStringAdd) {
   }
 }
 
-TEST(InterpreterParameter1) {
+TEST(InterpreterReceiverParameter) {
   HandleAndZoneScope handles;
   Isolate* isolate = handles.main_isolate();
   Zone* zone = handles.main_zone();
@@ -560,6 +559,24 @@ TEST(InterpreterParameter1) {
   builder.LoadAccumulatorWithRegister(builder.Receiver()).Return();
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
+  Handle<Object> object = InterpreterTester::NewObject("({ val : 123 })");
+
+  InterpreterTester tester(isolate, bytecode_array);
+  auto callable = tester.GetCallableWithReceiver<>();
+  Handle<Object> return_val = callable(object).ToHandleChecked();
+
+  CHECK(return_val.is_identical_to(object));
+}
+
+TEST(InterpreterParameter0) {
+  HandleAndZoneScope handles;
+  Isolate* isolate = handles.main_isolate();
+  Zone* zone = handles.main_zone();
+  BytecodeArrayBuilder builder(zone, 2, 0);
+
+  builder.LoadAccumulatorWithRegister(builder.Parameter(0)).Return();
+  Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
+
   InterpreterTester tester(isolate, bytecode_array);
   auto callable = tester.GetCallable<Handle<Object>>();
 
@@ -603,12 +620,12 @@ TEST(InterpreterParameter8) {
       .BinaryOperation(Token::Value::ADD, builder.Parameter(5), GetIndex(slot5))
       .BinaryOperation(Token::Value::ADD, builder.Parameter(6), GetIndex(slot6))
       .Return();
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array, metadata);
   using H = Handle<Object>;
-  auto callable = tester.GetCallable<H, H, H, H, H, H, H, H>();
+  auto callable = tester.GetCallableWithReceiver<H, H, H, H, H, H, H>();
 
   Handle<Smi> arg1 = Handle<Smi>(Smi::FromInt(1), handles.main_isolate());
   Handle<Smi> arg2 = Handle<Smi>(Smi::FromInt(2), handles.main_isolate());
@@ -743,7 +760,7 @@ TEST(InterpreterBinaryOpTypeFeedback) {
     LoadLiteralForTest(&builder, test_case.arg2);
     builder.BinaryOperation(test_case.op, reg, GetIndex(slot0)).Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
@@ -849,7 +866,7 @@ TEST(InterpreterBinaryOpSmiTypeFeedback) {
         .BinaryOperation(test_case.op, reg, GetIndex(slot0))
         .Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
@@ -891,7 +908,7 @@ TEST(InterpreterUnaryOpFeedback) {
       {Token::Value::DEC, smi_one, smi_min, number, bigint, str}};
   for (TestCase const& test_case : kTestCases) {
     i::FeedbackVectorSpec feedback_spec(zone);
-    BytecodeArrayBuilder builder(zone, 5, 0, &feedback_spec);
+    BytecodeArrayBuilder builder(zone, 6, 0, &feedback_spec);
 
     i::FeedbackSlot slot0 = feedback_spec.AddBinaryOpICSlot();
     i::FeedbackSlot slot1 = feedback_spec.AddBinaryOpICSlot();
@@ -902,15 +919,15 @@ TEST(InterpreterUnaryOpFeedback) {
     Handle<i::FeedbackMetadata> metadata =
         i::NewFeedbackMetadata(isolate, &feedback_spec);
 
-    builder.LoadAccumulatorWithRegister(builder.Receiver())
+    builder.LoadAccumulatorWithRegister(builder.Parameter(0))
         .UnaryOperation(test_case.op, GetIndex(slot0))
-        .LoadAccumulatorWithRegister(builder.Parameter(0))
-        .UnaryOperation(test_case.op, GetIndex(slot1))
         .LoadAccumulatorWithRegister(builder.Parameter(1))
-        .UnaryOperation(test_case.op, GetIndex(slot2))
+        .UnaryOperation(test_case.op, GetIndex(slot1))
         .LoadAccumulatorWithRegister(builder.Parameter(2))
-        .UnaryOperation(test_case.op, GetIndex(slot3))
+        .UnaryOperation(test_case.op, GetIndex(slot2))
         .LoadAccumulatorWithRegister(builder.Parameter(3))
+        .UnaryOperation(test_case.op, GetIndex(slot3))
+        .LoadAccumulatorWithRegister(builder.Parameter(4))
         .UnaryOperation(test_case.op, GetIndex(slot4))
         .Return();
 
@@ -959,7 +976,7 @@ TEST(InterpreterBitwiseTypeFeedback) {
 
   for (Token::Value op : kBitwiseBinaryOperators) {
     i::FeedbackVectorSpec feedback_spec(zone);
-    BytecodeArrayBuilder builder(zone, 4, 0, &feedback_spec);
+    BytecodeArrayBuilder builder(zone, 5, 0, &feedback_spec);
 
     i::FeedbackSlot slot0 = feedback_spec.AddBinaryOpICSlot();
     i::FeedbackSlot slot1 = feedback_spec.AddBinaryOpICSlot();
@@ -968,10 +985,10 @@ TEST(InterpreterBitwiseTypeFeedback) {
     Handle<i::FeedbackMetadata> metadata =
         i::NewFeedbackMetadata(isolate, &feedback_spec);
 
-    builder.LoadAccumulatorWithRegister(builder.Receiver())
-        .BinaryOperation(op, builder.Parameter(0), GetIndex(slot0))
-        .BinaryOperation(op, builder.Parameter(1), GetIndex(slot1))
-        .BinaryOperation(op, builder.Parameter(2), GetIndex(slot2))
+    builder.LoadAccumulatorWithRegister(builder.Parameter(0))
+        .BinaryOperation(op, builder.Parameter(1), GetIndex(slot0))
+        .BinaryOperation(op, builder.Parameter(2), GetIndex(slot1))
+        .BinaryOperation(op, builder.Parameter(3), GetIndex(slot2))
         .Return();
 
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
@@ -1015,7 +1032,7 @@ TEST(InterpreterParameter1Assign) {
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array);
-  auto callable = tester.GetCallable<Handle<Object>>();
+  auto callable = tester.GetCallableWithReceiver<>();
 
   Handle<Object> return_val =
       callable(Handle<Smi>(Smi::FromInt(3), handles.main_isolate()))
@@ -1146,11 +1163,11 @@ TEST(InterpreterLoadNamedProperty) {
   BytecodeArrayBuilder builder(zone, 1, 0, &feedback_spec);
 
   builder.LoadNamedProperty(builder.Receiver(), name, GetIndex(slot)).Return();
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array, metadata);
-  auto callable = tester.GetCallable<Handle<Object>>();
+  auto callable = tester.GetCallableWithReceiver<>();
 
   Handle<Object> object = InterpreterTester::NewObject("({ val : 123 })");
   // Test IC miss.
@@ -1200,11 +1217,11 @@ TEST(InterpreterLoadKeyedProperty) {
   builder.LoadLiteral(key)
       .LoadKeyedProperty(builder.Receiver(), GetIndex(slot))
       .Return();
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array, metadata);
-  auto callable = tester.GetCallable<Handle<Object>>();
+  auto callable = tester.GetCallableWithReceiver<>();
 
   Handle<Object> object = InterpreterTester::NewObject("({ key : 123 })");
   // Test IC miss.
@@ -1243,11 +1260,11 @@ TEST(InterpreterStoreNamedProperty) {
       .StoreNamedProperty(builder.Receiver(), name, GetIndex(slot),
                           LanguageMode::kStrict)
       .Return();
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array, metadata);
-  auto callable = tester.GetCallable<Handle<Object>>();
+  auto callable = tester.GetCallableWithReceiver<>();
   Handle<Object> object = InterpreterTester::NewObject("({ val : 123 })");
   // Test IC miss.
   Handle<Object> result;
@@ -1308,11 +1325,11 @@ TEST(InterpreterStoreKeyedProperty) {
       .StoreKeyedProperty(builder.Receiver(), Register(0), GetIndex(slot),
                           i::LanguageMode::kSloppy)
       .Return();
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   InterpreterTester tester(isolate, bytecode_array, metadata);
-  auto callable = tester.GetCallable<Handle<Object>>();
+  auto callable = tester.GetCallableWithReceiver<>();
   Handle<Object> object = InterpreterTester::NewObject("({ val : 123 })");
   // Test IC miss.
   Handle<Object> result;
@@ -1368,11 +1385,11 @@ TEST(InterpreterCall) {
     builder.CallProperty(reg, args, call_slot_index);
 
     builder.Return();
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
-    auto callable = tester.GetCallable<Handle<Object>>();
+    auto callable = tester.GetCallableWithReceiver<>();
 
     Handle<Object> object = InterpreterTester::NewObject(
         "new (function Obj() { this.func = function() { return 0x265; }})()");
@@ -1390,11 +1407,11 @@ TEST(InterpreterCall) {
         .MoveRegister(builder.Receiver(), args[0]);
     builder.CallProperty(reg, args, call_slot_index);
     builder.Return();
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
-    auto callable = tester.GetCallable<Handle<Object>>();
+    auto callable = tester.GetCallableWithReceiver<>();
 
     Handle<Object> object = InterpreterTester::NewObject(
         "new (function Obj() {"
@@ -1424,11 +1441,11 @@ TEST(InterpreterCall) {
 
     builder.Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
-    auto callable = tester.GetCallable<Handle<Object>>();
+    auto callable = tester.GetCallableWithReceiver<>();
 
     Handle<Object> object = InterpreterTester::NewObject(
         "new (function Obj() { "
@@ -1473,11 +1490,11 @@ TEST(InterpreterCall) {
 
     builder.Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
     InterpreterTester tester(isolate, bytecode_array, metadata);
-    auto callable = tester.GetCallable<Handle<Object>>();
+    auto callable = tester.GetCallableWithReceiver<>();
 
     Handle<Object> object = InterpreterTester::NewObject(
         "new (function Obj() { "
@@ -1538,7 +1555,7 @@ TEST(InterpreterJumps) {
   IncrementRegister(&builder, reg, 1, scratch, GetIndex(slot)).Jump(&label[1]);
   SetRegister(&builder, reg, 2048, scratch).Bind(&label[0]);
   IncrementRegister(&builder, reg, 2, scratch, GetIndex(slot1))
-      .JumpLoop(&loop_header, 0);
+      .JumpLoop(&loop_header, 0, 0);
   SetRegister(&builder, reg, 4096, scratch).Bind(&label[1]);
   IncrementRegister(&builder, reg, 4, scratch, GetIndex(slot2))
       .LoadAccumulatorWithRegister(reg)
@@ -1691,7 +1708,7 @@ TEST(InterpreterJumpConstantWith16BitOperand) {
   builder.LoadAccumulatorWithRegister(reg);
   builder.Return();
 
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
   BytecodeArrayIterator iterator(bytecode_array);
 
@@ -1735,7 +1752,7 @@ TEST(InterpreterJumpWith32BitOperand) {
   builder.Bind(&done);
   builder.Return();
 
-  ast_factory.Internalize(isolate->factory());
+  ast_factory.Internalize(isolate);
   Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
 
   BytecodeArrayIterator iterator(bytecode_array);
@@ -1873,7 +1890,7 @@ TEST(InterpreterHeapNumberComparisons) {
             .CompareOperation(comparison, r0, GetIndex(slot))
             .Return();
 
-        ast_factory.Internalize(isolate->factory());
+        ast_factory.Internalize(isolate);
         Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
         InterpreterTester tester(isolate, bytecode_array, metadata);
         auto callable = tester.GetCallable<>();
@@ -1920,7 +1937,7 @@ TEST(InterpreterBigIntComparisons) {
             .CompareOperation(comparison, r0, GetIndex(slot))
             .Return();
 
-        ast_factory.Internalize(isolate->factory());
+        ast_factory.Internalize(isolate);
         Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
         InterpreterTester tester(isolate, bytecode_array, metadata);
         auto callable = tester.GetCallable<>();
@@ -1968,7 +1985,7 @@ TEST(InterpreterStringComparisons) {
             .CompareOperation(comparison, r0, GetIndex(slot))
             .Return();
 
-        ast_factory.Internalize(isolate->factory());
+        ast_factory.Internalize(isolate);
         Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
         InterpreterTester tester(isolate, bytecode_array, metadata);
         auto callable = tester.GetCallable<>();
@@ -2080,7 +2097,7 @@ TEST(InterpreterMixedComparisons) {
             builder.CompareOperation(comparison, lhs_reg, GetIndex(slot))
                 .Return();
 
-            ast_factory.Internalize(isolate->factory());
+            ast_factory.Internalize(isolate);
             Handle<BytecodeArray> bytecode_array =
                 builder.ToBytecodeArray(isolate);
             InterpreterTester tester(isolate, bytecode_array, metadata);
@@ -2208,8 +2225,8 @@ TEST(InterpreterCompareTypeOf) {
     LiteralFlag literal_flag = kLiterals[l];
     if (literal_flag == LiteralFlag::kOther) continue;
 
-    BytecodeArrayBuilder builder(zone, 1, 0);
-    builder.LoadAccumulatorWithRegister(builder.Receiver())
+    BytecodeArrayBuilder builder(zone, 2, 0);
+    builder.LoadAccumulatorWithRegister(builder.Parameter(0))
         .CompareTypeOf(kLiterals[l])
         .Return();
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
@@ -2295,7 +2312,7 @@ TEST(InterpreterTestIn) {
         .CompareOperation(Token::Value::IN, r0, GetIndex(slot))
         .Return();
 
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
     InterpreterTester tester(isolate, bytecode_array, metadata);
     auto callable = tester.GetCallable<>();
@@ -2353,7 +2370,7 @@ TEST(InterpreterUnaryNotNonBoolean) {
     Register r0(0);
     LoadLiteralForTest(&builder, object_type_tuples[i].first);
     builder.LogicalNot(ToBooleanMode::kConvertToBoolean).Return();
-    ast_factory.Internalize(isolate->factory());
+    ast_factory.Internalize(isolate);
     Handle<BytecodeArray> bytecode_array = builder.ToBytecodeArray(isolate);
     InterpreterTester tester(isolate, bytecode_array);
     auto callable = tester.GetCallable<>();
@@ -5012,7 +5029,7 @@ TEST(InterpreterGenerators) {
   }
 }
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
 TEST(InterpreterWithNativeStack) {
   i::FLAG_interpreted_frames_native_stack = true;
 
@@ -5034,7 +5051,7 @@ TEST(InterpreterWithNativeStack) {
   CHECK(code.is_interpreter_trampoline_builtin());
   CHECK_NE(code.address(), interpreter_entry_trampoline->address());
 }
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
 TEST(InterpreterGetBytecodeHandler) {
   HandleAndZoneScope handles;
diff --git a/deps/v8/test/cctest/parsing/test-scanner-streams.cc b/deps/v8/test/cctest/parsing/test-scanner-streams.cc
index 28687cef5b..35b7048bb0 100644
--- a/deps/v8/test/cctest/parsing/test-scanner-streams.cc
+++ b/deps/v8/test/cctest/parsing/test-scanner-streams.cc
@@ -331,8 +331,8 @@ TEST(Utf8AdvanceUntilOverChunkBoundaries) {
   for (size_t i = 1; i < len; i++) {
     // Copy source string into buffer, splitting it at i.
     // Then add three chunks, 0..i-1, i..strlen-1, empty.
-    memcpy(buffer, unicode_utf8, i);
-    memcpy(buffer + i + 1, unicode_utf8 + i, len - i);
+    strncpy(buffer, unicode_utf8, i);
+    strncpy(buffer + i + 1, unicode_utf8 + i, len - i);
     buffer[i] = '\0';
     buffer[len + 1] = '\n';
     buffer[len + 2] = '\0';
@@ -360,8 +360,8 @@ TEST(Utf8ChunkBoundaries) {
   for (size_t i = 1; i < len; i++) {
     // Copy source string into buffer, splitting it at i.
     // Then add three chunks, 0..i-1, i..strlen-1, empty.
-    memcpy(buffer, unicode_utf8, i);
-    memcpy(buffer + i + 1, unicode_utf8 + i, len - i);
+    strncpy(buffer, unicode_utf8, i);
+    strncpy(buffer + i + 1, unicode_utf8 + i, len - i);
     buffer[i] = '\0';
     buffer[len + 1] = '\0';
     buffer[len + 2] = '\0';
diff --git a/deps/v8/test/cctest/test-accessors.cc b/deps/v8/test/cctest/test-accessors.cc
index e0c93501c2..ec14e8d0c2 100644
--- a/deps/v8/test/cctest/test-accessors.cc
+++ b/deps/v8/test/cctest/test-accessors.cc
@@ -298,13 +298,10 @@ static void HandleAllocatingGetter(
     const v8::PropertyCallbackInfo<v8::Value>& info) {
   ApiTestFuzzer::Fuzz();
   for (int i = 0; i < C; i++) {
-    v8::String::NewFromUtf8(info.GetIsolate(), "foo",
-                            v8::NewStringType::kNormal)
-        .ToLocalChecked();
+    USE(v8::String::NewFromUtf8Literal(info.GetIsolate(), "foo"));
   }
-  info.GetReturnValue().Set(v8::String::NewFromUtf8(info.GetIsolate(), "foo",
-                                                    v8::NewStringType::kNormal)
-                                .ToLocalChecked());
+  info.GetReturnValue().Set(
+      v8::String::NewFromUtf8Literal(info.GetIsolate(), "foo"));
 }
 
 
diff --git a/deps/v8/test/cctest/test-api-array-buffer.cc b/deps/v8/test/cctest/test-api-array-buffer.cc
index 9ce26323d8..b15fe80151 100644
--- a/deps/v8/test/cctest/test-api-array-buffer.cc
+++ b/deps/v8/test/cctest/test-api-array-buffer.cc
@@ -636,6 +636,43 @@ TEST(SharedArrayBuffer_NewBackingStore_CustomDeleter) {
   CHECK(backing_store_custom_called);
 }
 
+TEST(ArrayBuffer_NewBackingStore_EmptyDeleter) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope handle_scope(isolate);
+  char static_buffer[100];
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::ArrayBuffer::NewBackingStore(static_buffer, sizeof(static_buffer),
+                                       v8::BackingStore::EmptyDeleter, nullptr);
+  uint64_t external_memory_before =
+      isolate->AdjustAmountOfExternalAllocatedMemory(0);
+  v8::ArrayBuffer::New(isolate, std::move(backing_store));
+  uint64_t external_memory_after =
+      isolate->AdjustAmountOfExternalAllocatedMemory(0);
+  // The ArrayBuffer constructor does not increase the external memory counter.
+  // The counter may decrease however if the allocation triggers GC.
+  CHECK_GE(external_memory_before, external_memory_after);
+}
+
+TEST(SharedArrayBuffer_NewBackingStore_EmptyDeleter) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope handle_scope(isolate);
+  char static_buffer[100];
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::SharedArrayBuffer::NewBackingStore(
+          static_buffer, sizeof(static_buffer), v8::BackingStore::EmptyDeleter,
+          nullptr);
+  uint64_t external_memory_before =
+      isolate->AdjustAmountOfExternalAllocatedMemory(0);
+  v8::SharedArrayBuffer::New(isolate, std::move(backing_store));
+  uint64_t external_memory_after =
+      isolate->AdjustAmountOfExternalAllocatedMemory(0);
+  // The SharedArrayBuffer constructor does not increase the external memory
+  // counter. The counter may decrease however if the allocation triggers GC.
+  CHECK_GE(external_memory_before, external_memory_after);
+}
+
 THREADED_TEST(BackingStore_NotShared) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -729,46 +766,6 @@ TEST(BackingStore_HoldAllocatorAlive_UntilIsolateShutdown) {
   CHECK(allocator_weak.expired());
 }
 
-class NullptrAllocator final : public v8::ArrayBuffer::Allocator {
- public:
-  void* Allocate(size_t length) override {
-    CHECK_EQ(length, 0);
-    return nullptr;
-  }
-  void* AllocateUninitialized(size_t length) override {
-    CHECK_EQ(length, 0);
-    return nullptr;
-  }
-  void Free(void* data, size_t length) override { CHECK_EQ(data, nullptr); }
-};
-
-TEST(BackingStore_ReleaseAllocator_NullptrBackingStore) {
-  std::shared_ptr<NullptrAllocator> allocator =
-      std::make_shared<NullptrAllocator>();
-  std::weak_ptr<NullptrAllocator> allocator_weak(allocator);
-
-  v8::Isolate::CreateParams create_params;
-  create_params.array_buffer_allocator_shared = allocator;
-  v8::Isolate* isolate = v8::Isolate::New(create_params);
-  isolate->Enter();
-
-  allocator.reset();
-  create_params.array_buffer_allocator_shared.reset();
-  CHECK(!allocator_weak.expired());
-
-  {
-    std::shared_ptr<v8::BackingStore> backing_store =
-        v8::ArrayBuffer::NewBackingStore(isolate, 0);
-    // This should release a reference to the allocator, even though the
-    // buffer is empty/nullptr.
-    backing_store.reset();
-  }
-
-  isolate->Exit();
-  isolate->Dispose();
-  CHECK(allocator_weak.expired());
-}
-
 TEST(BackingStore_HoldAllocatorAlive_AfterIsolateShutdown) {
   std::shared_ptr<DummyAllocator> allocator =
       std::make_shared<DummyAllocator>();
@@ -801,3 +798,74 @@ TEST(BackingStore_HoldAllocatorAlive_AfterIsolateShutdown) {
   backing_store.reset();
   CHECK(allocator_weak.expired());
 }
+
+TEST(BackingStore_ReallocateExpand) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::ArrayBuffer::NewBackingStore(isolate, 10);
+  {
+    uint8_t* data = reinterpret_cast<uint8_t*>(
+        reinterpret_cast<uintptr_t>(backing_store->Data()));
+    for (uint8_t i = 0; i < 10; i++) {
+      data[i] = i;
+    }
+  }
+  std::unique_ptr<v8::BackingStore> new_backing_store =
+      v8::BackingStore::Reallocate(isolate, std::move(backing_store), 20);
+  CHECK_EQ(new_backing_store->ByteLength(), 20);
+  CHECK(!new_backing_store->IsShared());
+  {
+    uint8_t* data = reinterpret_cast<uint8_t*>(
+        reinterpret_cast<uintptr_t>(new_backing_store->Data()));
+    for (uint8_t i = 0; i < 10; i++) {
+      CHECK_EQ(data[i], i);
+    }
+    for (uint8_t i = 10; i < 20; i++) {
+      CHECK_EQ(data[i], 0);
+    }
+  }
+}
+
+TEST(BackingStore_ReallocateShrink) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::ArrayBuffer::NewBackingStore(isolate, 20);
+  {
+    uint8_t* data = reinterpret_cast<uint8_t*>(backing_store->Data());
+    for (uint8_t i = 0; i < 20; i++) {
+      data[i] = i;
+    }
+  }
+  std::unique_ptr<v8::BackingStore> new_backing_store =
+      v8::BackingStore::Reallocate(isolate, std::move(backing_store), 10);
+  CHECK_EQ(new_backing_store->ByteLength(), 10);
+  CHECK(!new_backing_store->IsShared());
+  {
+    uint8_t* data = reinterpret_cast<uint8_t*>(new_backing_store->Data());
+    for (uint8_t i = 0; i < 10; i++) {
+      CHECK_EQ(data[i], i);
+    }
+  }
+}
+
+TEST(BackingStore_ReallocateNotShared) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::ArrayBuffer::NewBackingStore(isolate, 20);
+  std::unique_ptr<v8::BackingStore> new_backing_store =
+      v8::BackingStore::Reallocate(isolate, std::move(backing_store), 10);
+  CHECK(!new_backing_store->IsShared());
+}
+
+TEST(BackingStore_ReallocateShared) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  std::unique_ptr<v8::BackingStore> backing_store =
+      v8::SharedArrayBuffer::NewBackingStore(isolate, 20);
+  std::unique_ptr<v8::BackingStore> new_backing_store =
+      v8::BackingStore::Reallocate(isolate, std::move(backing_store), 10);
+  CHECK(new_backing_store->IsShared());
+}
diff --git a/deps/v8/test/cctest/test-api-stack-traces.cc b/deps/v8/test/cctest/test-api-stack-traces.cc
index bceba18c4a..cc6795ba51 100644
--- a/deps/v8/test/cctest/test-api-stack-traces.cc
+++ b/deps/v8/test/cctest/test-api-stack-traces.cc
@@ -339,7 +339,7 @@ TEST(CaptureStackTrace) {
   CHECK(detailed_result->IsObject());
 
   // Test using function.name and function.displayName in stack trace
-  const char* function_name_source =
+  const char function_name_source[] =
       "function bar(function_name, display_name, testGroup) {\n"
       "  var f = new Function(`AnalyzeStackInNativeCode(${testGroup});`);\n"
       "  if (function_name) {\n"
@@ -356,9 +356,7 @@ TEST(CaptureStackTrace) {
       "bar('function.name', 239, 6);\n"
       "bar(239, undefined, 7);\n";
   v8::Local<v8::String> function_name_src =
-      v8::String::NewFromUtf8(isolate, function_name_source,
-                              v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8Literal(isolate, function_name_source);
   v8::ScriptCompiler::Source script_source3(function_name_src,
                                             v8::ScriptOrigin(origin));
   v8::Local<Value> function_name_result(
diff --git a/deps/v8/test/cctest/test-api.cc b/deps/v8/test/cctest/test-api.cc
index 5f84bfffcd..7f4b300203 100644
--- a/deps/v8/test/cctest/test-api.cc
+++ b/deps/v8/test/cctest/test-api.cc
@@ -37,6 +37,7 @@
 #include <unistd.h>  // NOLINT
 #endif
 
+#include "include/v8-fast-api-calls.h"
 #include "include/v8-util.h"
 #include "src/api/api-inl.h"
 #include "src/base/overflowing-math.h"
@@ -561,8 +562,7 @@ THREADED_TEST(ScriptMakingExternalString) {
     LocalContext env;
     v8::HandleScope scope(env->GetIsolate());
     Local<String> source =
-        String::NewFromTwoByte(env->GetIsolate(), two_byte_source,
-                               v8::NewStringType::kNormal)
+        String::NewFromTwoByte(env->GetIsolate(), two_byte_source)
             .ToLocalChecked();
     // Trigger GCs so that the newly allocated string moves to old gen.
     CcTest::CollectGarbage(i::NEW_SPACE);  // in survivor space now
@@ -624,15 +624,13 @@ TEST(MakingExternalStringConditions) {
 
   uint16_t* two_byte_string = AsciiToTwoByteString("s1");
   Local<String> tiny_local_string =
-      String::NewFromTwoByte(env->GetIsolate(), two_byte_string,
-                             v8::NewStringType::kNormal)
+      String::NewFromTwoByte(env->GetIsolate(), two_byte_string)
           .ToLocalChecked();
   i::DeleteArray(two_byte_string);
 
   two_byte_string = AsciiToTwoByteString("s1234");
   Local<String> local_string =
-      String::NewFromTwoByte(env->GetIsolate(), two_byte_string,
-                             v8::NewStringType::kNormal)
+      String::NewFromTwoByte(env->GetIsolate(), two_byte_string)
           .ToLocalChecked();
   i::DeleteArray(two_byte_string);
 
@@ -942,8 +940,7 @@ THREADED_TEST(StringConcat) {
 
     uint16_t* two_byte_source = AsciiToTwoByteString(two_byte_string_1);
     Local<String> right =
-        String::NewFromTwoByte(env->GetIsolate(), two_byte_source,
-                               v8::NewStringType::kNormal)
+        String::NewFromTwoByte(env->GetIsolate(), two_byte_source)
             .ToLocalChecked();
     i::DeleteArray(two_byte_source);
 
@@ -962,8 +959,7 @@ THREADED_TEST(StringConcat) {
     source = String::Concat(isolate, source, right);
 
     two_byte_source = AsciiToTwoByteString(two_byte_string_2);
-    right = String::NewFromTwoByte(env->GetIsolate(), two_byte_source,
-                                   v8::NewStringType::kNormal)
+    right = String::NewFromTwoByte(env->GetIsolate(), two_byte_source)
                 .ToLocalChecked();
     i::DeleteArray(two_byte_source);
 
@@ -3380,9 +3376,7 @@ THREADED_TEST(PrivatePropertiesOnProxies) {
 
   CHECK(priv2->Name()
             ->Equals(env.local(),
-                     v8::String::NewFromUtf8(isolate, "my-private",
-                                             v8::NewStringType::kNormal)
-                         .ToLocalChecked())
+                     v8::String::NewFromUtf8Literal(isolate, "my-private"))
             .FromJust());
 
   // Make sure delete of a non-existent private symbol property works.
@@ -3408,10 +3402,9 @@ THREADED_TEST(PrivatePropertiesOnProxies) {
            proxy->GetOwnPropertyNames(env.local()).ToLocalChecked()->Length());
   unsigned num_props =
       proxy->GetPropertyNames(env.local()).ToLocalChecked()->Length();
-  CHECK(proxy->Set(env.local(), v8::String::NewFromUtf8(
-                                    isolate, "bla", v8::NewStringType::kNormal)
-                                    .ToLocalChecked(),
-                   v8::Integer::New(isolate, 20))
+  CHECK(proxy
+            ->Set(env.local(), v8::String::NewFromUtf8Literal(isolate, "bla"),
+                  v8::Integer::New(isolate, 20))
             .FromJust());
   CHECK_EQ(1u,
            proxy->GetOwnPropertyNames(env.local()).ToLocalChecked()->Length());
@@ -3474,9 +3467,7 @@ THREADED_TEST(PrivateProperties) {
 
   CHECK(priv2->Name()
             ->Equals(env.local(),
-                     v8::String::NewFromUtf8(isolate, "my-private",
-                                             v8::NewStringType::kNormal)
-                         .ToLocalChecked())
+                     v8::String::NewFromUtf8Literal(isolate, "my-private"))
             .FromJust());
 
   // Make sure delete of a non-existent private symbol property works.
@@ -3502,9 +3493,7 @@ THREADED_TEST(PrivateProperties) {
            obj->GetOwnPropertyNames(env.local()).ToLocalChecked()->Length());
   unsigned num_props =
       obj->GetPropertyNames(env.local()).ToLocalChecked()->Length();
-  CHECK(obj->Set(env.local(), v8::String::NewFromUtf8(
-                                  isolate, "bla", v8::NewStringType::kNormal)
-                                  .ToLocalChecked(),
+  CHECK(obj->Set(env.local(), v8::String::NewFromUtf8Literal(isolate, "bla"),
                  v8::Integer::New(isolate, 20))
             .FromJust());
   CHECK_EQ(1u,
@@ -3999,9 +3988,8 @@ class TwoPassCallbackData {
     HandleScope scope(isolate);
     i::ScopedVector<char> buffer(40);
     i::SNPrintF(buffer, "%p", static_cast<void*>(this));
-    auto string = v8::String::NewFromUtf8(isolate, buffer.begin(),
-                                          v8::NewStringType::kNormal)
-                      .ToLocalChecked();
+    auto string =
+        v8::String::NewFromUtf8(isolate, buffer.begin()).ToLocalChecked();
     cell_.Reset(isolate, string);
     metadata_->instance_counter++;
   }
@@ -6841,6 +6829,9 @@ THREADED_TEST(UndetectableObject) {
                               .ToLocalChecked()
                               ->NewInstance(env.local())
                               .ToLocalChecked();
+
+  CHECK(obj->IsUndetectable());
+
   CHECK(
       env->Global()->Set(env.local(), v8_str("undetectable"), obj).FromJust());
 
@@ -8077,9 +8068,7 @@ THREADED_TEST(StringWrite) {
   // abc<Icelandic eth><Unicode snowman>.
   v8::Local<String> str2 = v8_str("abc\xC3\xB0\xE2\x98\x83");
   v8::Local<String> str3 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "abc\0def",
-                              v8::NewStringType::kNormal, 7)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8Literal(context->GetIsolate(), "abc\0def");
   // "ab" + lead surrogate + "wx" + trail surrogate + "yz"
   uint16_t orphans[8] = {0x61, 0x62, 0xD800, 0x77, 0x78, 0xDC00, 0x79, 0x7A};
   v8::Local<String> orphans_str =
@@ -8535,14 +8524,10 @@ THREADED_TEST(Utf16Symbol) {
   LocalContext context;
   v8::HandleScope scope(context->GetIsolate());
 
-  Local<String> symbol1 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "abc",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
-  Local<String> symbol2 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "abc",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+  Local<String> symbol1 = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "abc", v8::NewStringType::kInternalized);
+  Local<String> symbol2 = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "abc", v8::NewStringType::kInternalized);
   CHECK(SameSymbol(symbol1, symbol2));
 
   CompileRun(
@@ -8560,30 +8545,22 @@ THREADED_TEST(Utf16Symbol) {
       "if (sym3.charCodeAt(2) != 0xDC07) throw sym1.charCodeAt(2);"
       "if (sym4.length != 3) throw sym4;"
       "if (sym4.charCodeAt(2) != 0xDC08) throw sym2.charCodeAt(2);");
-  Local<String> sym0 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "benedictus",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
-  Local<String> sym0b =
-      v8::String::NewFromUtf8(context->GetIsolate(), "S\xC3\xB8ren",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
-  Local<String> sym1 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "\xED\xA0\x81\xED\xB0\x87",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+  Local<String> sym0 = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "benedictus", v8::NewStringType::kInternalized);
+  Local<String> sym0b = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "S\xC3\xB8ren", v8::NewStringType::kInternalized);
+  Local<String> sym1 = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "\xED\xA0\x81\xED\xB0\x87",
+      v8::NewStringType::kInternalized);
   Local<String> sym2 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "\xF0\x90\x90\x88",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
-  Local<String> sym3 = v8::String::NewFromUtf8(context->GetIsolate(),
-                                               "x\xED\xA0\x81\xED\xB0\x87",
-                                               v8::NewStringType::kInternalized)
-                           .ToLocalChecked();
+      v8::String::NewFromUtf8Literal(context->GetIsolate(), "\xF0\x90\x90\x88",
+                                     v8::NewStringType::kInternalized);
+  Local<String> sym3 = v8::String::NewFromUtf8Literal(
+      context->GetIsolate(), "x\xED\xA0\x81\xED\xB0\x87",
+      v8::NewStringType::kInternalized);
   Local<String> sym4 =
-      v8::String::NewFromUtf8(context->GetIsolate(), "x\xF0\x90\x90\x88",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8Literal(context->GetIsolate(), "x\xF0\x90\x90\x88",
+                                     v8::NewStringType::kInternalized);
   v8::Local<v8::Object> global = context->Global();
   Local<Value> s0 =
       global->Get(context.local(), v8_str("sym0")).ToLocalChecked();
@@ -13747,7 +13724,7 @@ UNINITIALIZED_TEST(SetJitCodeEventHandler) {
     const int kIterations = 10;
     for (int i = 0; i < kIterations; ++i) {
       LocalContext env(isolate);
-      i::AlwaysAllocateScope always_allocate(i_isolate);
+      i::AlwaysAllocateScopeForTesting always_allocate(heap);
       CompileRun(script);
 
       // Keep a strong reference to the code object in the handle scope.
@@ -15320,19 +15297,15 @@ THREADED_TEST(ReplaceConstantFunction) {
 THREADED_TEST(ScriptContextDependence) {
   LocalContext c1;
   v8::HandleScope scope(c1->GetIsolate());
-  const char *source = "foo";
+  const char source[] = "foo";
   v8::Local<v8::Script> dep = v8_compile(source);
   v8::ScriptCompiler::Source script_source(
-      v8::String::NewFromUtf8(c1->GetIsolate(), source,
-                              v8::NewStringType::kNormal)
-          .ToLocalChecked());
+      v8::String::NewFromUtf8Literal(c1->GetIsolate(), source));
   v8::Local<v8::UnboundScript> indep =
       v8::ScriptCompiler::CompileUnboundScript(c1->GetIsolate(), &script_source)
           .ToLocalChecked();
   c1->Global()
-      ->Set(c1.local(), v8::String::NewFromUtf8(c1->GetIsolate(), "foo",
-                                                v8::NewStringType::kNormal)
-                            .ToLocalChecked(),
+      ->Set(c1.local(), v8::String::NewFromUtf8Literal(c1->GetIsolate(), "foo"),
             v8::Integer::New(c1->GetIsolate(), 100))
       .FromJust();
   CHECK_EQ(
@@ -15346,9 +15319,7 @@ THREADED_TEST(ScriptContextDependence) {
            100);
   LocalContext c2;
   c2->Global()
-      ->Set(c2.local(), v8::String::NewFromUtf8(c2->GetIsolate(), "foo",
-                                                v8::NewStringType::kNormal)
-                            .ToLocalChecked(),
+      ->Set(c2.local(), v8::String::NewFromUtf8Literal(c2->GetIsolate(), "foo"),
             v8::Integer::New(c2->GetIsolate(), 101))
       .FromJust();
   CHECK_EQ(
@@ -16444,7 +16415,7 @@ TEST(RecursionWithSourceURLInMessageScriptResourceNameOrSourceURL) {
 static void CreateGarbageInOldSpace() {
   i::Factory* factory = CcTest::i_isolate()->factory();
   v8::HandleScope scope(CcTest::isolate());
-  i::AlwaysAllocateScope always_allocate(CcTest::i_isolate());
+  i::AlwaysAllocateScopeForTesting always_allocate(CcTest::i_isolate()->heap());
   for (int i = 0; i < 1000; i++) {
     factory->NewFixedArray(1000, i::AllocationType::kOld);
   }
@@ -16764,7 +16735,7 @@ TEST(VisitExternalStrings) {
   v8::Isolate* isolate = CcTest::isolate();
   LocalContext env;
   v8::HandleScope scope(isolate);
-  const char* string = "Some string";
+  const char string[] = "Some string";
   uint16_t* two_byte_string = AsciiToTwoByteString(string);
   TestResource* resource[4];
   resource[0] = new TestResource(two_byte_string);
@@ -16778,10 +16749,8 @@ TEST(VisitExternalStrings) {
 
   // Externalized symbol.
   resource[2] = new TestResource(two_byte_string, nullptr, false);
-  v8::Local<v8::String> string2 =
-      v8::String::NewFromUtf8(env->GetIsolate(), string,
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+  v8::Local<v8::String> string2 = v8::String::NewFromUtf8Literal(
+      env->GetIsolate(), string, v8::NewStringType::kInternalized);
   CHECK(string2->MakeExternal(resource[2]));
 
   // Symbolized External.
@@ -17282,8 +17251,7 @@ THREADED_TEST(FunctionGetDebugName) {
     v8::Local<v8::Function> f = v8::Local<v8::Function>::Cast(
         env->Global()
             ->Get(env.local(),
-                  v8::String::NewFromUtf8(isolate, functions[i * 2],
-                                          v8::NewStringType::kNormal)
+                  v8::String::NewFromUtf8(isolate, functions[i * 2])
                       .ToLocalChecked())
             .ToLocalChecked());
     CHECK_EQ(0, strcmp(functions[i * 2 + 1],
@@ -18021,9 +17989,7 @@ TEST(ContainsOnlyOneByte) {
           .ToLocalChecked();
   CHECK(!string->IsOneByte() && string->ContainsOnlyOneByte());
   // Counter example.
-  string = String::NewFromTwoByte(isolate, string_contents,
-                                  v8::NewStringType::kNormal)
-               .ToLocalChecked();
+  string = String::NewFromTwoByte(isolate, string_contents).ToLocalChecked();
   CHECK(string->IsOneByte() && string->ContainsOnlyOneByte());
   // Test left right and balanced cons strings.
   Local<String> base = v8_str("a");
@@ -19319,9 +19285,7 @@ v8::ModifyCodeGenerationFromStringsResult ModifyCodeGeneration(
     if (*i == '2') *i = '3';
   }
   return {/* codegen_allowed= */ true,
-          String::NewFromUtf8(context->GetIsolate(), *utf8,
-                              v8::NewStringType::kNormal)
-              .ToLocalChecked()};
+          String::NewFromUtf8(context->GetIsolate(), *utf8).ToLocalChecked()};
 }
 
 THREADED_TEST(AllowCodeGenFromStrings) {
@@ -19911,7 +19875,7 @@ TEST(RunMicrotasksIgnoresThrownExceptionsFromApi) {
     CHECK(!isolate->IsExecutionTerminating());
     isolate->EnqueueMicrotask(ThrowExceptionMicrotask);
     isolate->EnqueueMicrotask(IncrementCounterMicrotask);
-    isolate->RunMicrotasks();
+    isolate->PerformMicrotaskCheckpoint();
     CHECK_EQ(1, microtask_callback_count);
     CHECK(!try_catch.HasCaught());
   }
@@ -19928,21 +19892,25 @@ TEST(SetAutorunMicrotasks) {
   v8::HandleScope scope(env->GetIsolate());
   env->GetIsolate()->AddMicrotasksCompletedCallback(
       &MicrotasksCompletedCallback);
+
+  // If the policy is auto, there's a microtask checkpoint at the end of every
+  // zero-depth API call.
   CompileRun(
       "var ext1Calls = 0;"
       "var ext2Calls = 0;");
   CompileRun("1+1;");
   CHECK_EQ(0, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(0, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(0u, microtasks_completed_callback_count);
+  CHECK_EQ(4u, microtasks_completed_callback_count);
 
   env->GetIsolate()->EnqueueMicrotask(
       Function::New(env.local(), MicrotaskOne).ToLocalChecked());
   CompileRun("1+1;");
   CHECK_EQ(1, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(0, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(1u, microtasks_completed_callback_count);
+  CHECK_EQ(7u, microtasks_completed_callback_count);
 
+  // If the policy is explicit, microtask checkpoints are explicitly invoked.
   env->GetIsolate()->SetMicrotasksPolicy(v8::MicrotasksPolicy::kExplicit);
   env->GetIsolate()->EnqueueMicrotask(
       Function::New(env.local(), MicrotaskOne).ToLocalChecked());
@@ -19951,24 +19919,24 @@ TEST(SetAutorunMicrotasks) {
   CompileRun("1+1;");
   CHECK_EQ(1, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(0, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(1u, microtasks_completed_callback_count);
+  CHECK_EQ(7u, microtasks_completed_callback_count);
 
-  env->GetIsolate()->RunMicrotasks();
+  env->GetIsolate()->PerformMicrotaskCheckpoint();
   CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(1, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(2u, microtasks_completed_callback_count);
+  CHECK_EQ(8u, microtasks_completed_callback_count);
 
   env->GetIsolate()->EnqueueMicrotask(
       Function::New(env.local(), MicrotaskTwo).ToLocalChecked());
   CompileRun("1+1;");
   CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(1, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(2u, microtasks_completed_callback_count);
+  CHECK_EQ(8u, microtasks_completed_callback_count);
 
-  env->GetIsolate()->RunMicrotasks();
+  env->GetIsolate()->PerformMicrotaskCheckpoint();
   CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(2, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(3u, microtasks_completed_callback_count);
+  CHECK_EQ(9u, microtasks_completed_callback_count);
 
   env->GetIsolate()->SetMicrotasksPolicy(v8::MicrotasksPolicy::kAuto);
   env->GetIsolate()->EnqueueMicrotask(
@@ -19976,7 +19944,7 @@ TEST(SetAutorunMicrotasks) {
   CompileRun("1+1;");
   CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(3, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(4u, microtasks_completed_callback_count);
+  CHECK_EQ(12u, microtasks_completed_callback_count);
 
   env->GetIsolate()->EnqueueMicrotask(
       Function::New(env.local(), MicrotaskTwo).ToLocalChecked());
@@ -19985,13 +19953,13 @@ TEST(SetAutorunMicrotasks) {
     CompileRun("1+1;");
     CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
     CHECK_EQ(3, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-    CHECK_EQ(4u, microtasks_completed_callback_count);
+    CHECK_EQ(12u, microtasks_completed_callback_count);
   }
 
   CompileRun("1+1;");
   CHECK_EQ(2, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(4, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(5u, microtasks_completed_callback_count);
+  CHECK_EQ(15u, microtasks_completed_callback_count);
 
   env->GetIsolate()->RemoveMicrotasksCompletedCallback(
       &MicrotasksCompletedCallback);
@@ -20000,7 +19968,7 @@ TEST(SetAutorunMicrotasks) {
   CompileRun("1+1;");
   CHECK_EQ(3, CompileRun("ext1Calls")->Int32Value(env.local()).FromJust());
   CHECK_EQ(4, CompileRun("ext2Calls")->Int32Value(env.local()).FromJust());
-  CHECK_EQ(5u, microtasks_completed_callback_count);
+  CHECK_EQ(15u, microtasks_completed_callback_count);
 }
 
 
@@ -20015,7 +19983,7 @@ TEST(RunMicrotasksWithoutEnteringContext) {
     isolate->EnqueueMicrotask(
         Function::New(context, MicrotaskOne).ToLocalChecked());
   }
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   {
     Context::Scope context_scope(context);
     CHECK_EQ(1, CompileRun("ext1Calls")->Int32Value(context).FromJust());
@@ -20039,7 +20007,7 @@ static void Regress808911_CurrentContextWrapper(
   CHECK(isolate->GetCurrentContext() !=
         isolate->GetEnteredOrMicrotaskContext());
   isolate->EnqueueMicrotask(Regress808911_MicrotaskCallback, isolate);
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
 }
 
 THREADED_TEST(Regress808911) {
@@ -22507,7 +22475,7 @@ TEST(PromiseThen) {
                   .ToLocalChecked()
                   ->Int32Value(context.local())
                   .FromJust());
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(1, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22533,7 +22501,7 @@ TEST(PromiseThen) {
                   .ToLocalChecked()
                   ->Int32Value(context.local())
                   .FromJust());
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(0, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22553,7 +22521,7 @@ TEST(PromiseThen) {
                   .ToLocalChecked()
                   ->Int32Value(context.local())
                   .FromJust());
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(3, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22602,7 +22570,7 @@ TEST(PromiseThen2) {
                   .ToLocalChecked()
                   ->Int32Value(context.local())
                   .FromJust());
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(1, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22613,7 +22581,7 @@ TEST(PromiseThen2) {
                   .FromJust());
 
   Local<v8::Promise> b = a->Then(context.local(), f3, f2).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(1, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22624,7 +22592,7 @@ TEST(PromiseThen2) {
                   .FromJust());
 
   Local<v8::Promise> c = b->Then(context.local(), f1, f2).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(1, global->Get(context.local(), v8_str("x1"))
                   .ToLocalChecked()
                   ->Int32Value(context.local())
@@ -22635,7 +22603,7 @@ TEST(PromiseThen2) {
                     .FromJust());
 
   v8::Local<v8::Promise> d = c->Then(context.local(), f1, f2).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(103, global->Get(context.local(), v8_str("x1"))
                     .ToLocalChecked()
                     ->Int32Value(context.local())
@@ -22646,7 +22614,7 @@ TEST(PromiseThen2) {
                     .FromJust());
 
   v8::Local<v8::Promise> e = d->Then(context.local(), f3, f2).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(103, global->Get(context.local(), v8_str("x1"))
                     .ToLocalChecked()
                     ->Int32Value(context.local())
@@ -22657,7 +22625,7 @@ TEST(PromiseThen2) {
                     .FromJust());
 
   v8::Local<v8::Promise> f = e->Then(context.local(), f1, f3).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(103, global->Get(context.local(), v8_str("x1"))
                     .ToLocalChecked()
                     ->Int32Value(context.local())
@@ -22668,7 +22636,7 @@ TEST(PromiseThen2) {
                     .FromJust());
 
   f->Then(context.local(), f1, f2).ToLocalChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK_EQ(103, global->Get(context.local(), v8_str("x1"))
                     .ToLocalChecked()
                     ->Int32Value(context.local())
@@ -22703,12 +22671,8 @@ TEST(ResolvedPromiseReFulfill) {
   LocalContext context;
   v8::Isolate* isolate = context->GetIsolate();
   v8::HandleScope scope(isolate);
-  v8::Local<v8::String> value1 =
-      v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
-          .ToLocalChecked();
-  v8::Local<v8::String> value2 =
-      v8::String::NewFromUtf8(isolate, "bar", v8::NewStringType::kNormal)
-          .ToLocalChecked();
+  v8::Local<v8::String> value1 = v8::String::NewFromUtf8Literal(isolate, "foo");
+  v8::Local<v8::String> value2 = v8::String::NewFromUtf8Literal(isolate, "bar");
 
   v8::Local<v8::Promise::Resolver> resolver =
       v8::Promise::Resolver::New(context.local()).ToLocalChecked();
@@ -22734,12 +22698,8 @@ TEST(RejectedPromiseReFulfill) {
   LocalContext context;
   v8::Isolate* isolate = context->GetIsolate();
   v8::HandleScope scope(isolate);
-  v8::Local<v8::String> value1 =
-      v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
-          .ToLocalChecked();
-  v8::Local<v8::String> value2 =
-      v8::String::NewFromUtf8(isolate, "bar", v8::NewStringType::kNormal)
-          .ToLocalChecked();
+  v8::Local<v8::String> value1 = v8::String::NewFromUtf8Literal(isolate, "foo");
+  v8::Local<v8::String> value2 = v8::String::NewFromUtf8Literal(isolate, "bar");
 
   v8::Local<v8::Promise::Resolver> resolver =
       v8::Promise::Resolver::New(context.local()).ToLocalChecked();
@@ -22988,7 +22948,7 @@ TEST(ScriptPositionInfo) {
     // Fail when position is larger than script size.
     CHECK(!script1->GetPositionInfo(220384, &info, script1->NO_OFFSET));
 
-    i::Script::InitLineEnds(script1);
+    i::Script::InitLineEnds(i_isolate, script1);
   }
 }
 
@@ -25577,8 +25537,8 @@ THREADED_TEST(GlobalAccessorInfo) {
   v8::HandleScope scope(isolate);
   Local<v8::ObjectTemplate> global_template = v8::ObjectTemplate::New(isolate);
   global_template->SetAccessor(
-      v8::String::NewFromUtf8(isolate, "prop", v8::NewStringType::kInternalized)
-          .ToLocalChecked(),
+      v8::String::NewFromUtf8Literal(isolate, "prop",
+                                     v8::NewStringType::kInternalized),
       &ensure_receiver_is_global_proxy);
   LocalContext env(nullptr, global_template);
   CompileRun("for (var i = 0; i < 10; i++) this.prop");
@@ -25735,7 +25695,7 @@ TEST(DynamicImport) {
   i::MaybeHandle<i::JSPromise> maybe_promise =
       i_isolate->RunHostImportModuleDynamicallyCallback(referrer, specifier);
   i::Handle<i::JSPromise> promise = maybe_promise.ToHandleChecked();
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   CHECK(result->Equals(i::String::cast(promise->result())));
 }
 
@@ -25884,9 +25844,8 @@ TEST(PrimitiveArray) {
   array->Set(isolate, 0, symbol);
   CHECK(array->Get(isolate, 0)->IsSymbol());
 
-  Local<v8::String> string =
-      v8::String::NewFromUtf8(isolate, "test", v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+  Local<v8::String> string = v8::String::NewFromUtf8Literal(
+      isolate, "test", v8::NewStringType::kInternalized);
   array->Set(isolate, 1, string);
   CHECK(array->Get(isolate, 0)->IsSymbol());
   CHECK(array->Get(isolate, 1)->IsString());
@@ -25922,10 +25881,8 @@ TEST(PersistentValueMap) {
       std::string, v8::Value,
       v8::DefaultPersistentValueMapTraits<std::string, v8::Value>>
       map(isolate);
-  v8::Local<v8::Value> value =
-      v8::String::NewFromUtf8(isolate, "value",
-                              v8::NewStringType::kInternalized)
-          .ToLocalChecked();
+  v8::Local<v8::Value> value = v8::String::NewFromUtf8Literal(
+      isolate, "value", v8::NewStringType::kInternalized);
   map.Set("key", value);
 }
 
@@ -25979,6 +25936,8 @@ void AtomicsWaitCallbackForTesting(
   CHECK_EQ(timeout_in_ms, info->expected_timeout);
   CHECK_EQ(value, info->expected_value);
   CHECK_EQ(offset_in_bytes, info->expected_offset);
+  CHECK_EQ(v8::StateTag::ATOMICS_WAIT,
+           reinterpret_cast<i::Isolate*>(info->isolate)->current_vm_state());
 
   auto ThrowSomething = [&]() {
     info->isolate->ThrowException(v8::Integer::New(info->isolate, 42));
@@ -26435,7 +26394,7 @@ TEST(MicrotaskContextShouldBeNativeContext) {
       "  await 42;"
       "})().then(callback);}");
 
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
 }
 
 TEST(PreviewSetKeysIteratorEntriesWithDeleted) {
@@ -27007,3 +26966,329 @@ UNINITIALIZED_TEST(NestedIsolates) {
 }
 
 #undef THREADED_PROFILED_TEST
+
+#ifndef V8_LITE_MODE
+namespace {
+// The following should correspond to Chromium's kV8DOMWrapperObjectIndex.
+static const int kV8WrapperTypeIndex = 0;
+static const int kV8WrapperObjectIndex = 1;
+
+template <typename T>
+struct GetDeoptValue {
+  static Maybe<T> Get(v8::Local<v8::Value> value,
+                      v8::Local<v8::Context> context);
+};
+
+template <>
+struct GetDeoptValue<int32_t> {
+  static Maybe<int32_t> Get(v8::Local<v8::Value> value,
+                            v8::Local<v8::Context> context) {
+    return value->Int32Value(context);
+  }
+};
+
+template <>
+struct GetDeoptValue<uint32_t> {
+  static Maybe<uint32_t> Get(v8::Local<v8::Value> value,
+                             v8::Local<v8::Context> context) {
+    return value->Uint32Value(context);
+  }
+};
+
+template <>
+struct GetDeoptValue<int64_t> {
+  static Maybe<int64_t> Get(v8::Local<v8::Value> value,
+                            v8::Local<v8::Context> context) {
+    return value->IntegerValue(context);
+  }
+};
+
+template <>
+struct GetDeoptValue<bool> {
+  static Maybe<bool> Get(v8::Local<v8::Value> value,
+                         v8::Local<v8::Context> context) {
+    return v8::Just<bool>(value->BooleanValue(CcTest::isolate()));
+  }
+};
+
+template <typename T>
+struct ApiNumberChecker {
+  enum Result {
+    kNotCalled,
+    kSlowCalled,
+    kFastCalled,
+  };
+
+  explicit ApiNumberChecker(T value) {}
+
+  static void CheckArgFast(ApiNumberChecker<T>* receiver, T argument) {
+    CHECK_NE(receiver, nullptr);
+    receiver->result = kFastCalled;
+    receiver->fast_value = argument;
+  }
+
+  static void CheckArgSlow(const v8::FunctionCallbackInfo<v8::Value>& info) {
+    CHECK_EQ(info.Length(), 1);
+
+    v8::Object* receiver = v8::Object::Cast(*info.Holder());
+    ApiNumberChecker<T>* checker = static_cast<ApiNumberChecker<T>*>(
+        receiver->GetAlignedPointerFromInternalField(kV8WrapperObjectIndex));
+
+    CHECK_NOT_NULL(checker);
+    if (checker->result == kSlowCalled) return;
+    checker->result = kSlowCalled;
+
+    LocalContext env;
+    checker->slow_value = GetDeoptValue<T>::Get(info[0], env.local());
+  }
+
+  T fast_value = T();
+  Maybe<T> slow_value = v8::Nothing<T>();
+  Result result = kNotCalled;
+};
+
+enum class Behavior {
+  kSuccess,  // The callback function should be called with the expected value,
+             // which == initial.
+  kThrow,    // An exception should be thrown by the callback function.
+};
+
+enum class PathTaken {
+  kFast,  // The fast path is taken after optimization.
+  kSlow,  // The slow path is taken always.
+};
+
+template <typename T>
+void SetupTest(v8::Local<v8::Value> initial_value, LocalContext* env,
+               ApiNumberChecker<T>* checker) {
+  v8::Isolate* isolate = CcTest::isolate();
+
+  v8::CFunction c_func = v8::CFunction::Make(ApiNumberChecker<T>::CheckArgFast);
+
+  Local<v8::FunctionTemplate> checker_templ = v8::FunctionTemplate::New(
+      isolate, ApiNumberChecker<T>::CheckArgSlow, v8::Local<v8::Value>(),
+      v8::Local<v8::Signature>(), 1, v8::ConstructorBehavior::kAllow,
+      v8::SideEffectType::kHasSideEffect, &c_func);
+
+  v8::Local<v8::ObjectTemplate> object_template =
+      v8::ObjectTemplate::New(isolate);
+  object_template->SetInternalFieldCount(kV8WrapperObjectIndex + 1);
+  object_template->Set(v8_str("api_func"), checker_templ);
+
+  v8::Local<v8::Object> object =
+      object_template->NewInstance(env->local()).ToLocalChecked();
+  object->SetAlignedPointerInInternalField(kV8WrapperObjectIndex,
+                                           reinterpret_cast<void*>(checker));
+
+  CHECK((*env)
+            ->Global()
+            ->Set(env->local(), v8_str("receiver"), object)
+            .FromJust());
+  CHECK((*env)
+            ->Global()
+            ->Set(env->local(), v8_str("value"), initial_value)
+            .FromJust());
+  CompileRun(
+      "function func(arg) { receiver.api_func(arg); }"
+      "%PrepareFunctionForOptimization(func);"
+      "func(value);"
+      "%OptimizeFunctionOnNextCall(func);"
+      "func(value);");
+}
+
+template <typename T>
+void CallAndCheck(T expected_value, Behavior expected_behavior,
+                  PathTaken expected_path, v8::Local<v8::Value> initial_value) {
+  LocalContext env;
+  v8::TryCatch try_catch(CcTest::isolate());
+  ApiNumberChecker<T> checker(expected_value);
+
+  SetupTest<T>(initial_value, &env, &checker);
+
+  if (expected_behavior == Behavior::kThrow) {
+    CHECK(try_catch.HasCaught());
+    CHECK_NE(checker.result, ApiNumberChecker<T>::kFastCalled);
+  } else {
+    CHECK_EQ(try_catch.HasCaught(), false);
+  }
+
+  if (expected_path == PathTaken::kSlow) {
+    // The slow version callback should have been called twice.
+    CHECK_EQ(checker.result, ApiNumberChecker<T>::kSlowCalled);
+
+    if (expected_behavior != Behavior::kThrow) {
+      T slow_value_typed = checker.slow_value.ToChecked();
+      CHECK_EQ(slow_value_typed, expected_value);
+    }
+  } else if (expected_path == PathTaken::kFast) {
+    CHECK_EQ(checker.result, ApiNumberChecker<T>::kFastCalled);
+    CHECK_EQ(checker.fast_value, expected_value);
+  }
+}
+
+void CallAndDeopt() {
+  LocalContext env;
+  v8::Local<v8::Value> initial_value(v8_num(42));
+  ApiNumberChecker<int32_t> checker(42);
+  SetupTest(initial_value, &env, &checker);
+
+  v8::Local<v8::Value> function = CompileRun(
+      "try { func(BigInt(42)); } catch(e) {}"
+      "%PrepareFunctionForOptimization(func);"
+      "%OptimizeFunctionOnNextCall(func);"
+      "func(value);"
+      "func;");
+  CHECK(function->IsFunction());
+  i::Handle<i::JSFunction> ifunction =
+      i::Handle<i::JSFunction>::cast(v8::Utils::OpenHandle(*function));
+  CHECK(ifunction->IsOptimized());
+}
+
+void CallWithLessArguments() {
+  LocalContext env;
+  v8::Local<v8::Value> initial_value(v8_num(42));
+  ApiNumberChecker<int32_t> checker(42);
+  SetupTest(initial_value, &env, &checker);
+
+  CompileRun("func();");
+
+  // Passing not enough arguments should go through the slow path.
+  CHECK_EQ(checker.result, ApiNumberChecker<int32_t>::kSlowCalled);
+}
+
+void CallWithMoreArguments() {
+  LocalContext env;
+  v8::Local<v8::Value> initial_value(v8_num(42));
+  ApiNumberChecker<int32_t> checker(42);
+  SetupTest(initial_value, &env, &checker);
+
+  CompileRun(
+      "%PrepareFunctionForOptimization(func);"
+      "%OptimizeFunctionOnNextCall(func);"
+      "func(value, value);");
+
+  // Passing too many arguments should just ignore the extra ones.
+  CHECK_EQ(checker.result, ApiNumberChecker<int32_t>::kFastCalled);
+}
+}  // namespace
+
+namespace v8 {
+template <typename T>
+class WrapperTraits<ApiNumberChecker<T>> {
+ public:
+  static const void* GetTypeInfo() {
+    static const int tag = 0;
+    return reinterpret_cast<const void*>(&tag);
+  }
+};
+}  // namespace v8
+#endif  // V8_LITE_MODE
+
+TEST(FastApiCalls) {
+#ifndef V8_LITE_MODE
+  if (i::FLAG_jitless) return;
+
+  i::FLAG_turbo_fast_api_calls = true;
+  i::FLAG_opt = true;
+  i::FLAG_allow_natives_syntax = true;
+  // Disable --always_opt, otherwise we haven't generated the necessary
+  // feedback to go down the "best optimization" path for the fast call.
+  i::FLAG_always_opt = false;
+
+  v8::Isolate* isolate = CcTest::isolate();
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
+  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
+
+  v8::HandleScope scope(isolate);
+  LocalContext env;
+
+  // Main cases (the value fits in the type)
+  CallAndCheck<int32_t>(-42, Behavior::kSuccess, PathTaken::kFast, v8_num(-42));
+  CallAndCheck<uint32_t>(i::Smi::kMaxValue, Behavior::kSuccess,
+                         PathTaken::kFast, v8_num(i::Smi::kMaxValue));
+#ifdef V8_TARGET_ARCH_X64
+  CallAndCheck<int64_t>(static_cast<int64_t>(i::Smi::kMaxValue) + 1,
+                        Behavior::kSuccess, PathTaken::kFast,
+                        v8_num(static_cast<int64_t>(i::Smi::kMaxValue) + 1));
+#endif  // V8_TARGET_ARCH_X64
+
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Boolean::New(isolate, false));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Boolean::New(isolate, true));
+
+  // Corner cases (the value is out of bounds or of different type) - int32_t
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kFast, v8_num(-0.0));
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kFast,
+                        v8_num(std::numeric_limits<double>::quiet_NaN()));
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kFast,
+                        v8_num(std::numeric_limits<double>::infinity()));
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                        v8_str("some_string"));
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                        v8::Object::New(isolate));
+  CallAndCheck<int32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                        v8::Array::New(isolate));
+  CallAndCheck<int32_t>(0, Behavior::kThrow, PathTaken::kSlow,
+                        v8::BigInt::New(isolate, 42));
+  CallAndCheck<int32_t>(std::numeric_limits<int32_t>::min(), Behavior::kSuccess,
+                        PathTaken::kFast,
+                        v8_num(std::numeric_limits<int32_t>::min()));
+  CallAndCheck<int32_t>(
+      std::numeric_limits<int32_t>::min(), Behavior::kSuccess, PathTaken::kFast,
+      v8_num(static_cast<double>(std::numeric_limits<int32_t>::max()) + 1));
+
+  CallAndCheck<int32_t>(3, Behavior::kSuccess, PathTaken::kFast, v8_num(3.14));
+
+  // Corner cases - uint32_t
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kFast, v8_num(-0.0));
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kFast,
+                         v8_num(std::numeric_limits<double>::quiet_NaN()));
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kFast,
+                         v8_num(std::numeric_limits<double>::infinity()));
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                         v8_str("some_string"));
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                         v8::Object::New(isolate));
+  CallAndCheck<uint32_t>(0, Behavior::kSuccess, PathTaken::kSlow,
+                         v8::Array::New(isolate));
+  CallAndCheck<uint32_t>(0, Behavior::kThrow, PathTaken::kSlow,
+                         v8::BigInt::New(isolate, 42));
+  CallAndCheck<uint32_t>(std::numeric_limits<uint32_t>::min(),
+                         Behavior::kSuccess, PathTaken::kFast,
+                         v8_num(std::numeric_limits<uint32_t>::max() + 1));
+  CallAndCheck<uint32_t>(3, Behavior::kSuccess, PathTaken::kFast, v8_num(3.14));
+
+  // Corner cases - bool
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Undefined(isolate));
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Null(isolate));
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast, v8_num(0));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast, v8_num(42));
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast, v8_str(""));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast,
+                     v8_str("some_string"));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Symbol::New(isolate));
+  CallAndCheck<bool>(false, Behavior::kSuccess, PathTaken::kFast,
+                     v8::BigInt::New(isolate, 0));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast,
+                     v8::BigInt::New(isolate, 42));
+  CallAndCheck<bool>(true, Behavior::kSuccess, PathTaken::kFast,
+                     v8::Object::New(isolate));
+
+  // Check for the deopt loop protection
+  CallAndDeopt();
+
+  // Wrong number of arguments
+  CallWithLessArguments();
+  CallWithMoreArguments();
+
+  // TODO(mslekova): Add corner cases for 64-bit values.
+  // TODO(mslekova): Add main cases for float and double.
+  // TODO(mslekova): Restructure the tests so that the fast optimized calls
+  // are compared against the slow optimized calls.
+#endif  // V8_LITE_MODE
+}
diff --git a/deps/v8/test/cctest/test-assembler-arm64.cc b/deps/v8/test/cctest/test-assembler-arm64.cc
index 8813815317..7b9a3ee842 100644
--- a/deps/v8/test/cctest/test-assembler-arm64.cc
+++ b/deps/v8/test/cctest/test-assembler-arm64.cc
@@ -186,6 +186,7 @@ static void InitializeVM() {
 #define RESET()                                                \
   owned_buf->MakeWritable();                                   \
   __ Reset();                                                  \
+  __ CodeEntry();                                              \
   /* Reset the machine state (like simulator.ResetState()). */ \
   __ Msr(NZCV, xzr);                                           \
   __ Msr(FPCR, xzr);
@@ -193,8 +194,8 @@ static void InitializeVM() {
 #define START_AFTER_RESET()                                                    \
   __ PushCalleeSavedRegisters();
 
-#define START()                                                                \
-  RESET();                                                                     \
+#define START() \
+  RESET();      \
   START_AFTER_RESET();
 
 #define RUN()                                      \
@@ -1649,27 +1650,27 @@ TEST(adr) {
   __ Adr(x3, &label_1);
   __ Adr(x4, &label_1);
 
-  __ Bind(&label_2);
+  __ Bind(&label_2, BranchTargetIdentifier::kBtiJump);
   __ Eor(x5, x2, Operand(x3));  // Ensure that x2,x3 and x4 are identical.
   __ Eor(x6, x2, Operand(x4));
   __ Orr(x0, x0, Operand(x5));
   __ Orr(x0, x0, Operand(x6));
   __ Br(x2);  // label_1, label_3
 
-  __ Bind(&label_3);
+  __ Bind(&label_3, BranchTargetIdentifier::kBtiJump);
   __ Adr(x2, &label_3);   // Self-reference (offset 0).
   __ Eor(x1, x1, Operand(x2));
   __ Adr(x2, &label_4);   // Simple forward reference.
   __ Br(x2);  // label_4
 
-  __ Bind(&label_1);
+  __ Bind(&label_1, BranchTargetIdentifier::kBtiJump);
   __ Adr(x2, &label_3);   // Multiple reverse references to the same label.
   __ Adr(x3, &label_3);
   __ Adr(x4, &label_3);
   __ Adr(x5, &label_2);   // Simple reverse reference.
   __ Br(x5);  // label_2
 
-  __ Bind(&label_4);
+  __ Bind(&label_4, BranchTargetIdentifier::kBtiJump);
   END();
 
   RUN();
@@ -1695,11 +1696,11 @@ TEST(adr_far) {
   __ Adr(x10, &near_forward, MacroAssembler::kAdrFar);
   __ Br(x10);
   __ B(&fail);
-  __ Bind(&near_backward);
+  __ Bind(&near_backward, BranchTargetIdentifier::kBtiJump);
   __ Orr(x0, x0, 1 << 1);
   __ B(&test_far);
 
-  __ Bind(&near_forward);
+  __ Bind(&near_forward, BranchTargetIdentifier::kBtiJump);
   __ Orr(x0, x0, 1 << 0);
   __ Adr(x10, &near_backward, MacroAssembler::kAdrFar);
   __ Br(x10);
@@ -1708,7 +1709,7 @@ TEST(adr_far) {
   __ Adr(x10, &far_forward, MacroAssembler::kAdrFar);
   __ Br(x10);
   __ B(&fail);
-  __ Bind(&far_backward);
+  __ Bind(&far_backward, BranchTargetIdentifier::kBtiJump);
   __ Orr(x0, x0, 1 << 3);
   __ B(&done);
 
@@ -1722,8 +1723,7 @@ TEST(adr_far) {
     }
   }
 
-
-  __ Bind(&far_forward);
+  __ Bind(&far_forward, BranchTargetIdentifier::kBtiJump);
   __ Orr(x0, x0, 1 << 2);
   __ Adr(x10, &far_backward, MacroAssembler::kAdrFar);
   __ Br(x10);
@@ -1832,7 +1832,7 @@ TEST(branch_to_reg) {
   SETUP();
 
   // Test br.
-  Label fn1, after_fn1;
+  Label fn1, after_fn1, after_bl1;
 
   START();
   __ Mov(x29, lr);
@@ -1847,9 +1847,10 @@ TEST(branch_to_reg) {
 
   __ Bind(&after_fn1);
   __ Bl(&fn1);
+  __ Bind(&after_bl1, BranchTargetIdentifier::kBtiJump);  // For Br(x0) in fn1.
 
   // Test blr.
-  Label fn2, after_fn2;
+  Label fn2, after_fn2, after_bl2;
 
   __ Mov(x2, 0);
   __ B(&after_fn2);
@@ -1861,6 +1862,7 @@ TEST(branch_to_reg) {
 
   __ Bind(&after_fn2);
   __ Bl(&fn2);
+  __ Bind(&after_bl2, BranchTargetIdentifier::kBtiCall);  // For Blr(x0) in fn2.
   __ Mov(x3, lr);
 
   __ Mov(lr, x29);
@@ -1873,6 +1875,76 @@ TEST(branch_to_reg) {
   CHECK_EQUAL_64(84, x2);
 }
 
+static void BtiHelper(Register ipreg) {
+  SETUP();
+
+  Label jump_target, jump_call_target, call_target, done;
+  START();
+  UseScratchRegisterScope temps(&masm);
+  temps.Exclude(ipreg);
+  __ Adr(x0, &jump_target);
+  __ Br(x0);
+  __ Nop();
+  __ Bind(&jump_target, BranchTargetIdentifier::kBtiJump);
+  __ Adr(x0, &call_target);
+  __ Blr(x0);
+  __ Adr(ipreg, &jump_call_target);
+  __ Blr(ipreg);
+  __ Adr(lr, &done);  // Make Ret return to done label.
+  __ Br(ipreg);
+  __ Bind(&call_target, BranchTargetIdentifier::kBtiCall);
+  __ Ret();
+  __ Bind(&jump_call_target, BranchTargetIdentifier::kBtiJumpCall);
+  __ Ret();
+  __ Bind(&done);
+  END();
+
+#ifdef USE_SIMULATOR
+  simulator.SetGuardedPages(true);
+  RUN();
+#endif  // USE_SIMULATOR
+}
+
+TEST(bti) {
+  BtiHelper(x16);
+  BtiHelper(x17);
+}
+
+TEST(unguarded_bti_is_nop) {
+  SETUP();
+
+  Label start, none, c, j, jc;
+  START();
+  __ B(&start);
+  __ Bind(&none, BranchTargetIdentifier::kBti);
+  __ Bind(&c, BranchTargetIdentifier::kBtiCall);
+  __ Bind(&j, BranchTargetIdentifier::kBtiJump);
+  __ Bind(&jc, BranchTargetIdentifier::kBtiJumpCall);
+  CHECK(__ SizeOfCodeGeneratedSince(&none) == 4 * kInstrSize);
+  __ Ret();
+
+  Label jump_to_c, call_to_j;
+  __ Bind(&start);
+  __ Adr(x0, &none);
+  __ Adr(lr, &jump_to_c);
+  __ Br(x0);
+
+  __ Bind(&jump_to_c);
+  __ Adr(x0, &c);
+  __ Adr(lr, &call_to_j);
+  __ Br(x0);
+
+  __ Bind(&call_to_j);
+  __ Adr(x0, &j);
+  __ Blr(x0);
+  END();
+
+#ifdef USE_SIMULATOR
+  simulator.SetGuardedPages(false);
+  RUN();
+#endif  // USE_SIMULATOR
+}
+
 TEST(compare_branch) {
   INIT_V8();
   SETUP();
@@ -6631,11 +6703,7 @@ static void LdrLiteralRangeHelper(
 
   size_t expected_pool_size = 0;
 
-#if defined(_M_ARM64) && !defined(__clang__)
-  auto PoolSizeAt = [pool_entries, kEntrySize](int pc_offset) {
-#else
-  auto PoolSizeAt = [unaligned_emission](int pc_offset) {
-#endif
+  auto PoolSizeAt = [&](int pc_offset) {
     // To determine padding, consider the size of the prologue of the pool,
     // and the jump around the pool, which we always need.
     size_t prologue_size = 2 * kInstrSize + kInstrSize;
@@ -12121,9 +12189,10 @@ static void PushPopSimpleHelper(int reg_count, int reg_size,
   // Registers in the TmpList can be used by the macro assembler for debug code
   // (for example in 'Pop'), so we can't use them here.
   // x18 is reserved for the platform register.
-  // Disallow x31 / xzr, to ensure this list has an even number of elements, to
-  // ensure alignment.
-  RegList allowed = ~(masm.TmpList()->list() | x18.bit() | x31.bit());
+  // For simplicity, exclude LR as well, as we would need to sign it when
+  // pushing it. This also ensures that the list has an even number of elements,
+  // which is needed for alignment.
+  RegList allowed = ~(masm.TmpList()->list() | x18.bit() | lr.bit());
   if (reg_count == kPushPopMaxRegCount) {
     reg_count = CountSetBits(allowed, kNumberOfRegisters);
   }
@@ -12157,7 +12226,8 @@ static void PushPopSimpleHelper(int reg_count, int reg_size,
       case PushPopByFour:
         // Push high-numbered registers first (to the highest addresses).
         for (i = reg_count; i >= 4; i -= 4) {
-          __ Push(r[i-1], r[i-2], r[i-3], r[i-4]);
+          __ Push<TurboAssembler::kDontStoreLR>(r[i - 1], r[i - 2], r[i - 3],
+                                                r[i - 4]);
         }
         // Finish off the leftovers.
         switch (i) {
@@ -12170,7 +12240,7 @@ static void PushPopSimpleHelper(int reg_count, int reg_size,
         }
         break;
       case PushPopRegList:
-        __ PushSizeRegList(list, reg_size);
+        __ PushSizeRegList<TurboAssembler::kDontStoreLR>(list, reg_size);
         break;
     }
 
@@ -12181,7 +12251,8 @@ static void PushPopSimpleHelper(int reg_count, int reg_size,
       case PushPopByFour:
         // Pop low-numbered registers first (from the lowest addresses).
         for (i = 0; i <= (reg_count-4); i += 4) {
-          __ Pop(r[i], r[i+1], r[i+2], r[i+3]);
+          __ Pop<TurboAssembler::kDontLoadLR>(r[i], r[i + 1], r[i + 2],
+                                              r[i + 3]);
         }
         // Finish off the leftovers.
         switch (reg_count - i) {
@@ -12194,7 +12265,7 @@ static void PushPopSimpleHelper(int reg_count, int reg_size,
         }
         break;
       case PushPopRegList:
-        __ PopSizeRegList(list, reg_size);
+        __ PopSizeRegList<TurboAssembler::kDontLoadLR>(list, reg_size);
         break;
     }
   }
@@ -12525,10 +12596,10 @@ TEST(push_pop) {
   __ Claim(2);
   __ PushXRegList(0);
   __ PopXRegList(0);
-  // Don't push/pop x18 (platform register) or xzr (for alignment)
-  RegList all_regs = 0xFFFFFFFF & ~(x18.bit() | x31.bit());
-  __ PushXRegList(all_regs);
-  __ PopXRegList(all_regs);
+  // Don't push/pop x18 (platform register) or lr
+  RegList all_regs = 0xFFFFFFFF & ~(x18.bit() | lr.bit());
+  __ PushXRegList<TurboAssembler::kDontStoreLR>(all_regs);
+  __ PopXRegList<TurboAssembler::kDontLoadLR>(all_regs);
   __ Drop(12);
 
   END();
@@ -13909,7 +13980,7 @@ TEST(blr_lr) {
   __ Mov(x0, 0xDEADBEEF);
   __ B(&end);
 
-  __ Bind(&target);
+  __ Bind(&target, BranchTargetIdentifier::kBtiCall);
   __ Mov(x0, 0xC001C0DE);
 
   __ Bind(&end);
@@ -14527,13 +14598,11 @@ TEST(near_call_no_relocation) {
 
   __ Bind(&test);
   __ Mov(x0, 0x0);
-  __ Push(lr, xzr);
   {
     Assembler::BlockConstPoolScope scope(&masm);
     int offset = (function.pos() - __ pc_offset()) / kInstrSize;
     __ near_call(offset, RelocInfo::NONE);
   }
-  __ Pop(xzr, lr);
   END();
 
   RUN();
@@ -14753,7 +14822,7 @@ TEST(jump_tables_forward) {
   }
 
   for (int i = 0; i < kNumCases; ++i) {
-    __ Bind(&labels[i]);
+    __ Bind(&labels[i], BranchTargetIdentifier::kBtiJump);
     __ Mov(value, values[i]);
     __ B(&done);
   }
@@ -14801,7 +14870,7 @@ TEST(jump_tables_backward) {
   __ B(&loop);
 
   for (int i = 0; i < kNumCases; ++i) {
-    __ Bind(&labels[i]);
+    __ Bind(&labels[i], BranchTargetIdentifier::kBtiJump);
     __ Mov(value, values[i]);
     __ B(&done);
   }
@@ -14863,7 +14932,7 @@ TEST(internal_reference_linked) {
   __ dcptr(&done);
   __ Tbz(x0, 1, &done);
 
-  __ Bind(&done);
+  __ Bind(&done, BranchTargetIdentifier::kBtiJump);
   __ Mov(x0, 1);
 
   END();
diff --git a/deps/v8/test/cctest/test-code-pages.cc b/deps/v8/test/cctest/test-code-pages.cc
index 93eddb0a4c..7fafe62629 100644
--- a/deps/v8/test/cctest/test-code-pages.cc
+++ b/deps/v8/test/cctest/test-code-pages.cc
@@ -21,10 +21,8 @@ namespace test_code_pages {
 // 2 - Have code pages. ARM32 only
 // 3 - Nothing - This feature does not work on other platforms.
 #if defined(V8_TARGET_ARCH_ARM)
-static const bool kHaveCodeRange = false;
 static const bool kHaveCodePages = true;
 #else
-static const bool kHaveCodeRange = kRequiresCodeRange;
 static const bool kHaveCodePages = false;
 #endif  // defined(V8_TARGET_ARCH_ARM)
 
@@ -86,11 +84,10 @@ bool PagesContainsAddress(std::vector<MemoryRange>* pages,
 }  // namespace
 
 TEST(CodeRangeCorrectContents) {
-  if (!kHaveCodeRange) return;
-
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+  if (!i_isolate->RequiresCodeRange()) return;
 
   std::vector<MemoryRange>* pages = i_isolate->GetCodePages();
 
@@ -128,12 +125,12 @@ TEST(CodePagesCorrectContents) {
 }
 
 TEST(OptimizedCodeWithCodeRange) {
-  if (!kHaveCodeRange) return;
-
   FLAG_allow_natives_syntax = true;
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+  if (!i_isolate->RequiresCodeRange()) return;
+
   HandleScope scope(i_isolate);
 
   std::string foo_str = getFooCode(1);
@@ -255,7 +252,6 @@ TEST(OptimizedCodeWithCodePages) {
 }
 
 TEST(LargeCodeObject) {
-  if (!kHaveCodeRange && !kHaveCodePages) return;
   // We don't want incremental marking to start which could cause the code to
   // not be collected on the CollectGarbage() call.
   ManualGCScope manual_gc_scope;
@@ -263,6 +259,7 @@ TEST(LargeCodeObject) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+  if (!i_isolate->RequiresCodeRange() && !kHaveCodePages) return;
 
   // Create a big function that ends up in CODE_LO_SPACE.
   const int instruction_size = Page::kPageSize + 1;
@@ -290,7 +287,7 @@ TEST(LargeCodeObject) {
 
     std::vector<MemoryRange>* pages = i_isolate->GetCodePages();
 
-    if (kHaveCodeRange) {
+    if (i_isolate->RequiresCodeRange()) {
       CHECK(PagesContainsAddress(pages, foo_code->address()));
     } else {
       CHECK(PagesHasExactPage(pages, foo_code->address()));
@@ -371,7 +368,6 @@ class SamplingThread : public base::Thread {
 };
 
 TEST(LargeCodeObjectWithSignalHandler) {
-  if (!kHaveCodeRange && !kHaveCodePages) return;
   // We don't want incremental marking to start which could cause the code to
   // not be collected on the CollectGarbage() call.
   ManualGCScope manual_gc_scope;
@@ -379,6 +375,7 @@ TEST(LargeCodeObjectWithSignalHandler) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+  if (!i_isolate->RequiresCodeRange() && !kHaveCodePages) return;
 
   // Create a big function that ends up in CODE_LO_SPACE.
   const int instruction_size = Page::kPageSize + 1;
@@ -421,7 +418,7 @@ TEST(LargeCodeObjectWithSignalHandler) {
     // Check that the page was added.
     std::vector<MemoryRange> pages =
         SamplingThread::DoSynchronousSample(isolate);
-    if (kHaveCodeRange) {
+    if (i_isolate->RequiresCodeRange()) {
       CHECK(PagesContainsAddress(&pages, foo_code->address()));
     } else {
       CHECK(PagesHasExactPage(&pages, foo_code->address()));
@@ -447,7 +444,6 @@ TEST(LargeCodeObjectWithSignalHandler) {
 }
 
 TEST(Sorted) {
-  if (!kHaveCodeRange && !kHaveCodePages) return;
   // We don't want incremental marking to start which could cause the code to
   // not be collected on the CollectGarbage() call.
   ManualGCScope manual_gc_scope;
@@ -455,6 +451,7 @@ TEST(Sorted) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
+  if (!i_isolate->RequiresCodeRange() && !kHaveCodePages) return;
 
   // Create a big function that ends up in CODE_LO_SPACE.
   const int instruction_size = Page::kPageSize + 1;
@@ -507,7 +504,7 @@ TEST(Sorted) {
       // Check that the pages were added.
       std::vector<MemoryRange> pages =
           SamplingThread::DoSynchronousSample(isolate);
-      if (kHaveCodeRange) {
+      if (i_isolate->RequiresCodeRange()) {
         CHECK_EQ(pages.size(), initial_num_pages);
       } else {
         CHECK_EQ(pages.size(), initial_num_pages + 3);
@@ -528,7 +525,7 @@ TEST(Sorted) {
 
     std::vector<MemoryRange> pages =
         SamplingThread::DoSynchronousSample(isolate);
-    if (kHaveCodeRange) {
+    if (i_isolate->RequiresCodeRange()) {
       CHECK_EQ(pages.size(), initial_num_pages);
     } else {
       CHECK_EQ(pages.size(), initial_num_pages + 2);
diff --git a/deps/v8/test/cctest/test-code-stub-assembler.cc b/deps/v8/test/cctest/test-code-stub-assembler.cc
index 623ff0d0f3..755041e0fb 100644
--- a/deps/v8/test/cctest/test-code-stub-assembler.cc
+++ b/deps/v8/test/cctest/test-code-stub-assembler.cc
@@ -728,10 +728,16 @@ TEST(TryToName) {
 
   {
     // TryToName(<internalized uncacheable number string greater than
-    // array index>) => is_keyisunique: <internalized string>.
+    // array index but less than MAX_SAFE_INTEGER>) => 32-bit platforms
+    // take the if_keyisunique path, 64-bit platforms bail out because they
+    // let the runtime handle the string-to-size_t parsing.
     Handle<Object> key =
         isolate->factory()->InternalizeUtf8String("4294967296");
+#if V8_TARGET_ARCH_64_BIT
+    ft.CheckTrue(key, expect_bailout);
+#else
     ft.CheckTrue(key, expect_unique, key);
+#endif
   }
 
   {
@@ -1203,8 +1209,8 @@ TEST(TryHasOwnProperty) {
 
   enum Result { kFound, kNotFound, kBailout };
   {
-    Node* object = m.Parameter(0);
-    Node* unique_name = m.Parameter(1);
+    TNode<HeapObject> object = m.CAST(m.Parameter(0));
+    TNode<Name> unique_name = m.CAST(m.Parameter(1));
     TNode<MaybeObject> expected_result =
         m.UncheckedCast<MaybeObject>(m.Parameter(2));
 
@@ -2292,7 +2298,8 @@ class AppendJSArrayCodeStubAssembler : public CodeStubAssembler {
       : CodeStubAssembler(state), kind_(kind) {}
 
   void TestAppendJSArrayImpl(Isolate* isolate, CodeAssemblerTester* csa_tester,
-                             Object o1, Object o2, Object o3, Object o4,
+                             Handle<Object> o1, Handle<Object> o2,
+                             Handle<Object> o3, Handle<Object> o4,
                              int initial_size, int result_size) {
     Handle<JSArray> array = isolate->factory()->NewJSArray(
         kind_, 2, initial_size, INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE);
@@ -2315,23 +2322,22 @@ class AppendJSArrayCodeStubAssembler : public CodeStubAssembler {
 
     FunctionTester ft(csa_tester->GenerateCode(), kNumParams);
 
-    Handle<Object> result =
-        ft.Call(Handle<Object>(o1, isolate), Handle<Object>(o2, isolate),
-                Handle<Object>(o3, isolate), Handle<Object>(o4, isolate))
-            .ToHandleChecked();
+    Handle<Object> result = ft.Call(o1, o2, o3, o4).ToHandleChecked();
 
     CHECK_EQ(kind_, array->GetElementsKind());
     CHECK_EQ(result_size, Handle<Smi>::cast(result)->value());
     CHECK_EQ(result_size, Smi::ToInt(array->length()));
-    Object obj = *JSObject::GetElement(isolate, array, 2).ToHandleChecked();
-    HeapObject undefined_value = ReadOnlyRoots(isolate).undefined_value();
-    CHECK_EQ(result_size < 3 ? undefined_value : o1, obj);
-    obj = *JSObject::GetElement(isolate, array, 3).ToHandleChecked();
-    CHECK_EQ(result_size < 4 ? undefined_value : o2, obj);
-    obj = *JSObject::GetElement(isolate, array, 4).ToHandleChecked();
-    CHECK_EQ(result_size < 5 ? undefined_value : o3, obj);
-    obj = *JSObject::GetElement(isolate, array, 5).ToHandleChecked();
-    CHECK_EQ(result_size < 6 ? undefined_value : o4, obj);
+    Handle<Object> obj =
+        JSObject::GetElement(isolate, array, 2).ToHandleChecked();
+    Handle<HeapObject> undefined_value =
+        Handle<HeapObject>(ReadOnlyRoots(isolate).undefined_value(), isolate);
+    CHECK_EQ(result_size < 3 ? *undefined_value : *o1, *obj);
+    obj = JSObject::GetElement(isolate, array, 3).ToHandleChecked();
+    CHECK_EQ(result_size < 4 ? *undefined_value : *o2, *obj);
+    obj = JSObject::GetElement(isolate, array, 4).ToHandleChecked();
+    CHECK_EQ(result_size < 5 ? *undefined_value : *o3, *obj);
+    obj = JSObject::GetElement(isolate, array, 5).ToHandleChecked();
+    CHECK_EQ(result_size < 6 ? *undefined_value : *o4, *obj);
   }
 
   static void TestAppendJSArray(Isolate* isolate, ElementsKind kind, Object o1,
@@ -2339,8 +2345,10 @@ class AppendJSArrayCodeStubAssembler : public CodeStubAssembler {
                                 int initial_size, int result_size) {
     CodeAssemblerTester asm_tester(isolate, kNumParams);
     AppendJSArrayCodeStubAssembler m(asm_tester.state(), kind);
-    m.TestAppendJSArrayImpl(isolate, &asm_tester, o1, o2, o3, o4, initial_size,
-                            result_size);
+    m.TestAppendJSArrayImpl(
+        isolate, &asm_tester, Handle<Object>(o1, isolate),
+        Handle<Object>(o2, isolate), Handle<Object>(o3, isolate),
+        Handle<Object>(o4, isolate), initial_size, result_size);
   }
 
  private:
@@ -3305,8 +3313,8 @@ TEST(ExtractFixedArrayCOWForceCopy) {
     CodeStubAssembler m(asm_tester.state());
     CodeStubAssembler::ExtractFixedArrayFlags flags;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kAllFixedArrays;
-    m.Return(m.ExtractFixedArray(m.Parameter(0), m.SmiConstant(0), nullptr,
-                                 nullptr, flags,
+    m.Return(m.ExtractFixedArray(m.CAST(m.Parameter(0)), m.SmiConstant(0),
+                                 nullptr, nullptr, flags,
                                  CodeStubAssembler::SMI_PARAMETERS));
   }
   FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
@@ -3334,8 +3342,8 @@ TEST(ExtractFixedArraySimple) {
     CodeStubAssembler::ExtractFixedArrayFlags flags;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kAllFixedArrays;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kDontCopyCOW;
-    m.Return(m.ExtractFixedArray(m.Parameter(0), m.Parameter(1), m.Parameter(2),
-                                 nullptr, flags,
+    m.Return(m.ExtractFixedArray(m.CAST(m.Parameter(0)), m.Parameter(1),
+                                 m.Parameter(2), nullptr, flags,
                                  CodeStubAssembler::SMI_PARAMETERS));
   }
   FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
@@ -3361,7 +3369,7 @@ TEST(ExtractFixedArraySimpleSmiConstant) {
     CodeStubAssembler::ExtractFixedArrayFlags flags;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kAllFixedArrays;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kDontCopyCOW;
-    m.Return(m.ExtractFixedArray(m.Parameter(0), m.SmiConstant(1),
+    m.Return(m.ExtractFixedArray(m.CAST(m.Parameter(0)), m.SmiConstant(1),
                                  m.SmiConstant(2), nullptr, flags,
                                  CodeStubAssembler::SMI_PARAMETERS));
   }
@@ -3385,7 +3393,7 @@ TEST(ExtractFixedArraySimpleIntPtrConstant) {
     CodeStubAssembler::ExtractFixedArrayFlags flags;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kAllFixedArrays;
     flags |= CodeStubAssembler::ExtractFixedArrayFlag::kDontCopyCOW;
-    m.Return(m.ExtractFixedArray(m.Parameter(0), m.IntPtrConstant(1),
+    m.Return(m.ExtractFixedArray(m.CAST(m.Parameter(0)), m.IntPtrConstant(1),
                                  m.IntPtrConstant(2), nullptr, flags,
                                  CodeStubAssembler::INTPTR_PARAMETERS));
   }
@@ -3407,8 +3415,8 @@ TEST(ExtractFixedArraySimpleIntPtrConstantNoDoubles) {
   {
     CodeStubAssembler m(asm_tester.state());
     m.Return(m.ExtractFixedArray(
-        m.Parameter(0), m.IntPtrConstant(1), m.IntPtrConstant(2), nullptr,
-        CodeStubAssembler::ExtractFixedArrayFlag::kFixedArrays,
+        m.CAST(m.Parameter(0)), m.IntPtrConstant(1), m.IntPtrConstant(2),
+        nullptr, CodeStubAssembler::ExtractFixedArrayFlag::kFixedArrays,
         CodeStubAssembler::INTPTR_PARAMETERS));
   }
   FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
@@ -3430,7 +3438,8 @@ TEST(ExtractFixedArraySimpleIntPtrParameters) {
     CodeStubAssembler m(asm_tester.state());
     TNode<IntPtrT> p1_untagged = m.SmiUntag(m.Parameter(1));
     TNode<IntPtrT> p2_untagged = m.SmiUntag(m.Parameter(2));
-    m.Return(m.ExtractFixedArray(m.Parameter(0), p1_untagged, p2_untagged));
+    m.Return(
+        m.ExtractFixedArray(m.CAST(m.Parameter(0)), p1_untagged, p2_untagged));
   }
   FunctionTester ft(asm_tester.GenerateCode(), kNumParams);
 
@@ -3622,7 +3631,7 @@ TEST(TestCallBuiltinInlineTrampoline) {
 
   const int kContextOffset = 2;
   Node* str = m.Parameter(0);
-  Node* context = m.Parameter(kNumParams + kContextOffset);
+  TNode<Context> context = m.CAST(m.Parameter(kNumParams + kContextOffset));
 
   TNode<Smi> index = m.SmiConstant(2);
 
@@ -3648,7 +3657,7 @@ DISABLED_TEST(TestCallBuiltinIndirectLoad) {
 
   const int kContextOffset = 2;
   Node* str = m.Parameter(0);
-  Node* context = m.Parameter(kNumParams + kContextOffset);
+  TNode<Context> context = m.CAST(m.Parameter(kNumParams + kContextOffset));
 
   TNode<Smi> index = m.SmiConstant(2);
 
diff --git a/deps/v8/test/cctest/test-constantpool.cc b/deps/v8/test/cctest/test-constantpool.cc
index a861655adc..3d063ac770 100644
--- a/deps/v8/test/cctest/test-constantpool.cc
+++ b/deps/v8/test/cctest/test-constantpool.cc
@@ -12,7 +12,7 @@
 namespace v8 {
 namespace internal {
 
-#if defined(V8_TARGET_ARCH_PPC)
+#if defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 const ConstantPoolEntry::Type kPtrType = ConstantPoolEntry::INTPTR;
 const ConstantPoolEntry::Type kDblType = ConstantPoolEntry::DOUBLE;
@@ -249,7 +249,7 @@ TEST(ConstantPoolNoSharing) {
   CHECK_EQ(access, kOvflAccess);
 }
 
-#endif  // defined(V8_TARGET_ARCH_PPC)
+#endif  // defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/test-debug-helper.cc b/deps/v8/test/cctest/test-debug-helper.cc
index 513b9ac1b9..a8b1ecb7a9 100644
--- a/deps/v8/test/cctest/test-debug-helper.cc
+++ b/deps/v8/test/cctest/test-debug-helper.cc
@@ -122,6 +122,7 @@ class StringResource : public v8::String::ExternalStringResource {
 TEST(GetObjectProperties) {
   CcTest::InitializeVM();
   v8::Isolate* isolate = CcTest::isolate();
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   v8::HandleScope scope(isolate);
   LocalContext context;
   // Claim we don't know anything about the heap layout.
@@ -180,11 +181,8 @@ TEST(GetObjectProperties) {
               : Contains(props->brief, "maybe EmptyFixedArray"));
 
     // Provide a heap first page so the API can be more sure.
-    heap_addresses.read_only_space_first_page =
-        reinterpret_cast<uintptr_t>(reinterpret_cast<i::Isolate*>(isolate)
-                                        ->heap()
-                                        ->read_only_space()
-                                        ->first_page());
+    heap_addresses.read_only_space_first_page = reinterpret_cast<uintptr_t>(
+        i_isolate->heap()->read_only_space()->first_page());
     props =
         d::GetObjectProperties(properties_or_hash, &ReadMemory, heap_addresses);
     CHECK(props->type_check_result ==
@@ -373,10 +371,25 @@ TEST(GetObjectProperties) {
       ReadProp<i::Tagged_t>(*props, "shared_function_info"), &ReadMemory,
       heap_addresses);
   const d::ObjectProperty& flags = FindProp(*props, "flags");
-  CheckStructProp(*flags.struct_fields[0], "v8::internal::FunctionKind",
-                  "function_kind", 0, 5, 0);
+  CHECK_GE(flags.num_struct_fields, 3);
+  CheckStructProp(*flags.struct_fields[0], "FunctionKind", "function_kind", 0,
+                  5, 0);
   CheckStructProp(*flags.struct_fields[1], "bool", "is_native", 0, 1, 5);
   CheckStructProp(*flags.struct_fields[2], "bool", "is_strict", 0, 1, 6);
+
+  // Get data about a different bitfield struct which is contained within a smi.
+  Handle<i::JSFunction> function = Handle<i::JSFunction>::cast(o);
+  Handle<i::SharedFunctionInfo> shared(function->shared(), i_isolate);
+  Handle<i::DebugInfo> debug_info =
+      i_isolate->debug()->GetOrCreateDebugInfo(shared);
+  props =
+      d::GetObjectProperties(debug_info->ptr(), &ReadMemory, heap_addresses);
+  const d::ObjectProperty& debug_flags = FindProp(*props, "flags");
+  CHECK_GE(debug_flags.num_struct_fields, 5);
+  CheckStructProp(*debug_flags.struct_fields[0], "bool", "has_break_info", 0, 1,
+                  i::kSmiTagSize + i::kSmiShiftSize);
+  CheckStructProp(*debug_flags.struct_fields[4], "bool", "can_break_at_entry",
+                  0, 1, i::kSmiTagSize + i::kSmiShiftSize + 4);
 }
 
 TEST(ListObjectClasses) {
diff --git a/deps/v8/test/cctest/test-debug.cc b/deps/v8/test/cctest/test-debug.cc
index 4aae4294da..ed669db806 100644
--- a/deps/v8/test/cctest/test-debug.cc
+++ b/deps/v8/test/cctest/test-debug.cc
@@ -35,6 +35,7 @@
 #include "src/debug/debug.h"
 #include "src/deoptimizer/deoptimizer.h"
 #include "src/execution/frames.h"
+#include "src/execution/microtask-queue.h"
 #include "src/objects/objects-inl.h"
 #include "src/snapshot/snapshot.h"
 #include "src/utils/utils.h"
@@ -2932,9 +2933,11 @@ TEST(DebugBreak) {
 
 class DebugScopingListener : public v8::debug::DebugDelegate {
  public:
-  void BreakProgramRequested(
-      v8::Local<v8::Context>,
-      const std::vector<v8::debug::BreakpointId>&) override {
+  void ExceptionThrown(v8::Local<v8::Context> paused_context,
+                       v8::Local<v8::Value> exception,
+                       v8::Local<v8::Value> promise, bool is_uncaught,
+                       v8::debug::ExceptionType exception_type) override {
+    break_count_++;
     auto stack_traces =
         v8::debug::StackTraceIterator::Create(CcTest::isolate());
     v8::debug::Location location = stack_traces->GetSourceLocation();
@@ -2957,6 +2960,10 @@ class DebugScopingListener : public v8::debug::DebugDelegate {
     scopes->Advance();
     CHECK(scopes->Done());
   }
+  unsigned break_count() const { return break_count_; }
+
+ private:
+  unsigned break_count_ = 0;
 };
 
 TEST(DebugBreakInWrappedScript) {
@@ -2996,6 +3003,7 @@ TEST(DebugBreakInWrappedScript) {
 
   // Get rid of the debug event listener.
   v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CHECK_EQ(1, delegate.break_count());
   CheckDebuggerUnloaded();
 }
 
@@ -3234,7 +3242,7 @@ TEST(DebugScriptLineEndsAreAscending) {
     Handle<v8::internal::Script> script = Handle<v8::internal::Script>(
         v8::internal::Script::cast(instances->get(i)), CcTest::i_isolate());
 
-    v8::internal::Script::InitLineEnds(script);
+    v8::internal::Script::InitLineEnds(CcTest::i_isolate(), script);
     v8::internal::FixedArray ends =
         v8::internal::FixedArray::cast(script->line_ends());
     CHECK_GT(ends.length(), 0);
@@ -3545,10 +3553,8 @@ TEST(AfterCompileEventOnBindToContext) {
   ScriptCompiledDelegate delegate;
   v8::debug::SetDebugDelegate(isolate, &delegate);
 
-  const char* source = "var a=1";
   v8::ScriptCompiler::Source script_source(
-      v8::String::NewFromUtf8(isolate, source, v8::NewStringType::kNormal)
-          .ToLocalChecked());
+      v8::String::NewFromUtf8Literal(isolate, "var a=1"));
 
   v8::Local<v8::UnboundScript> unbound =
       v8::ScriptCompiler::CompileUnboundScript(isolate, &script_source)
@@ -4955,3 +4961,639 @@ TEST(GetPrivateMethodsAndAccessors) {
     }
   }
 }
+
+TEST(GetPrivateStaticMethodsAndAccessors) {
+  i::FLAG_harmony_private_methods = true;
+  LocalContext env;
+  v8::Isolate* v8_isolate = CcTest::isolate();
+  v8::HandleScope scope(v8_isolate);
+  v8::Local<v8::Context> context = env.local();
+
+  v8::Local<v8::String> source = v8_str(
+      "var X = class {\n"
+      "  static #staticMethod() { }\n"
+      "  static get #staticAccessor() { }\n"
+      "  static set #staticAccessor(val) { }\n"
+      "  static get #staticReadOnly() { }\n"
+      "  static set #staticWriteOnly(val) { }\n"
+      "}\n");
+  CompileRun(source);
+  v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(
+      env->Global()
+          ->Get(context, v8_str(env->GetIsolate(), "X"))
+          .ToLocalChecked());
+  std::vector<v8::Local<v8::Value>> names;
+  std::vector<v8::Local<v8::Value>> values;
+  CHECK(v8::debug::GetPrivateMembers(context, object, &names, &values));
+
+  CHECK_EQ(names.size(), 4);
+  for (int i = 0; i < 4; i++) {
+    v8::Local<v8::Value> name = names[i];
+    v8::Local<v8::Value> value = values[i];
+    CHECK(name->IsString());
+    std::string name_str = FromString(v8_isolate, name.As<v8::String>());
+    if (name_str == "#staticMethod") {
+      CHECK(value->IsFunction());
+    } else {
+      CHECK(v8::debug::AccessorPair::IsAccessorPair(value));
+      v8::Local<v8::debug::AccessorPair> accessors =
+          value.As<v8::debug::AccessorPair>();
+      if (name_str == "#staticAccessor") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsFunction());
+      } else if (name_str == "#staticReadOnly") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsNull());
+      } else {
+        CHECK_EQ(name_str, "#staticWriteOnly");
+        CHECK(accessors->getter()->IsNull());
+        CHECK(accessors->setter()->IsFunction());
+      }
+    }
+  }
+}
+
+TEST(GetPrivateStaticAndInstanceMethodsAndAccessors) {
+  i::FLAG_harmony_private_methods = true;
+  LocalContext env;
+  v8::Isolate* v8_isolate = CcTest::isolate();
+  v8::HandleScope scope(v8_isolate);
+  v8::Local<v8::Context> context = env.local();
+
+  v8::Local<v8::String> source = v8_str(
+      "var X = class {\n"
+      "  static #staticMethod() { }\n"
+      "  static get #staticAccessor() { }\n"
+      "  static set #staticAccessor(val) { }\n"
+      "  static get #staticReadOnly() { }\n"
+      "  static set #staticWriteOnly(val) { }\n"
+      "  #method() { }\n"
+      "  get #accessor() { }\n"
+      "  set #accessor(val) { }\n"
+      "  get #readOnly() { }\n"
+      "  set #writeOnly(val) { }\n"
+      "}\n"
+      "var x = new X()\n");
+  CompileRun(source);
+  v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(
+      env->Global()
+          ->Get(context, v8_str(env->GetIsolate(), "X"))
+          .ToLocalChecked());
+  std::vector<v8::Local<v8::Value>> names;
+  std::vector<v8::Local<v8::Value>> values;
+  CHECK(v8::debug::GetPrivateMembers(context, object, &names, &values));
+
+  CHECK_EQ(names.size(), 4);
+  for (int i = 0; i < 4; i++) {
+    v8::Local<v8::Value> name = names[i];
+    v8::Local<v8::Value> value = values[i];
+    CHECK(name->IsString());
+    std::string name_str = FromString(v8_isolate, name.As<v8::String>());
+    if (name_str == "#staticMethod") {
+      CHECK(value->IsFunction());
+    } else {
+      CHECK(v8::debug::AccessorPair::IsAccessorPair(value));
+      v8::Local<v8::debug::AccessorPair> accessors =
+          value.As<v8::debug::AccessorPair>();
+      if (name_str == "#staticAccessor") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsFunction());
+      } else if (name_str == "#staticReadOnly") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsNull());
+      } else {
+        CHECK_EQ(name_str, "#staticWriteOnly");
+        CHECK(accessors->getter()->IsNull());
+        CHECK(accessors->setter()->IsFunction());
+      }
+    }
+  }
+
+  names.clear();
+  values.clear();
+  object = v8::Local<v8::Object>::Cast(
+      env->Global()
+          ->Get(context, v8_str(env->GetIsolate(), "x"))
+          .ToLocalChecked());
+  CHECK(v8::debug::GetPrivateMembers(context, object, &names, &values));
+
+  CHECK_EQ(names.size(), 4);
+  for (int i = 0; i < 4; i++) {
+    v8::Local<v8::Value> name = names[i];
+    v8::Local<v8::Value> value = values[i];
+    CHECK(name->IsString());
+    std::string name_str = FromString(v8_isolate, name.As<v8::String>());
+    if (name_str == "#method") {
+      CHECK(value->IsFunction());
+    } else {
+      CHECK(v8::debug::AccessorPair::IsAccessorPair(value));
+      v8::Local<v8::debug::AccessorPair> accessors =
+          value.As<v8::debug::AccessorPair>();
+      if (name_str == "#accessor") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsFunction());
+      } else if (name_str == "#readOnly") {
+        CHECK(accessors->getter()->IsFunction());
+        CHECK(accessors->setter()->IsNull());
+      } else {
+        CHECK_EQ(name_str, "#writeOnly");
+        CHECK(accessors->getter()->IsNull());
+        CHECK(accessors->setter()->IsFunction());
+      }
+    }
+  }
+}
+
+namespace {
+class SetTerminateOnResumeDelegate : public v8::debug::DebugDelegate {
+ public:
+  enum Options {
+    kNone,
+    kPerformMicrotaskCheckpointAtBreakpoint,
+    kRunJavaScriptAtBreakpoint
+  };
+  explicit SetTerminateOnResumeDelegate(Options options = kNone)
+      : options_(options) {}
+  void BreakProgramRequested(v8::Local<v8::Context> paused_context,
+                             const std::vector<v8::debug::BreakpointId>&
+                                 inspector_break_points_hit) override {
+    break_count_++;
+    v8::Isolate* isolate = paused_context->GetIsolate();
+    v8::debug::SetTerminateOnResume(isolate);
+    if (options_ == kPerformMicrotaskCheckpointAtBreakpoint) {
+      v8::MicrotasksScope::PerformCheckpoint(isolate);
+    }
+    if (options_ == kRunJavaScriptAtBreakpoint) {
+      CompileRun("globalVariable = globalVariable + 1");
+    }
+  }
+
+  void ExceptionThrown(v8::Local<v8::Context> paused_context,
+                       v8::Local<v8::Value> exception,
+                       v8::Local<v8::Value> promise, bool is_uncaught,
+                       v8::debug::ExceptionType exception_type) override {
+    exception_thrown_count_++;
+    v8::debug::SetTerminateOnResume(paused_context->GetIsolate());
+  }
+
+  int break_count() const { return break_count_; }
+  int exception_thrown_count() const { return exception_thrown_count_; }
+
+ private:
+  int break_count_ = 0;
+  int exception_thrown_count_ = 0;
+  Options options_;
+};
+}  // anonymous namespace
+
+TEST(TerminateOnResumeAtBreakpoint) {
+  break_point_hit_count = 0;
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    // If the delegate doesn't request termination on resume from breakpoint,
+    // foo diverges.
+    v8::Script::Compile(
+        context,
+        v8_str(env->GetIsolate(), "function foo(){debugger; while(true){}}"))
+        .ToLocalChecked()
+        ->Run(context)
+        .ToLocalChecked();
+    v8::Local<v8::Function> foo = v8::Local<v8::Function>::Cast(
+        env->Global()
+            ->Get(context, v8_str(env->GetIsolate(), "foo"))
+            .ToLocalChecked());
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+namespace {
+bool microtask_one_ran = false;
+static void MicrotaskOne(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  CHECK(v8::MicrotasksScope::IsRunningMicrotasks(info.GetIsolate()));
+  v8::HandleScope scope(info.GetIsolate());
+  v8::MicrotasksScope microtasks(info.GetIsolate(),
+                                 v8::MicrotasksScope::kDoNotRunMicrotasks);
+  ExpectInt32("1 + 1", 2);
+  microtask_one_ran = true;
+}
+}  // namespace
+
+TEST(TerminateOnResumeRunMicrotaskAtBreakpoint) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  SetTerminateOnResumeDelegate delegate(
+      SetTerminateOnResumeDelegate::kPerformMicrotaskCheckpointAtBreakpoint);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    // Enqueue a microtask that gets run while we are paused at the breakpoint.
+    env->GetIsolate()->EnqueueMicrotask(
+        v8::Function::New(env.local(), MicrotaskOne).ToLocalChecked());
+
+    // If the delegate doesn't request termination on resume from breakpoint,
+    // foo diverges.
+    v8::Script::Compile(
+        context,
+        v8_str(env->GetIsolate(), "function foo(){debugger; while(true){}}"))
+        .ToLocalChecked()
+        ->Run(context)
+        .ToLocalChecked();
+    v8::Local<v8::Function> foo = v8::Local<v8::Function>::Cast(
+        env->Global()
+            ->Get(context, v8_str(env->GetIsolate(), "foo"))
+            .ToLocalChecked());
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 1);
+    CHECK(microtask_one_ran);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+TEST(TerminateOnResumeRunJavaScriptAtBreakpoint) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  CompileRun("var globalVariable = 0;");
+  SetTerminateOnResumeDelegate delegate(
+      SetTerminateOnResumeDelegate::kRunJavaScriptAtBreakpoint);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    // If the delegate doesn't request termination on resume from breakpoint,
+    // foo diverges.
+    v8::Script::Compile(
+        context,
+        v8_str(env->GetIsolate(), "function foo(){debugger; while(true){}}"))
+        .ToLocalChecked()
+        ->Run(context)
+        .ToLocalChecked();
+    v8::Local<v8::Function> foo = v8::Local<v8::Function>::Cast(
+        env->Global()
+            ->Get(context, v8_str(env->GetIsolate(), "foo"))
+            .ToLocalChecked());
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  ExpectInt32("globalVariable", 1);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+TEST(TerminateOnResumeAtException) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  ChangeBreakOnException(true, true);
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    const char* source = "throw new Error(); while(true){};";
+
+    v8::ScriptCompiler::Source script_source(v8_str(source));
+    v8::Local<v8::Function> foo =
+        v8::ScriptCompiler::CompileFunctionInContext(
+            env.local(), &script_source, 0, nullptr, 0, nullptr)
+            .ToLocalChecked();
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 0);
+    CHECK_EQ(delegate.exception_thrown_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+TEST(TerminateOnResumeAtBreakOnEntry) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    v8::Local<v8::Function> builtin =
+        CompileRun("String.prototype.repeat").As<v8::Function>();
+    SetBreakPoint(builtin, 0);
+    v8::Local<v8::Value> val = CompileRun("'b'.repeat(10)");
+    CHECK_EQ(delegate.break_count(), 1);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.exception_thrown_count(), 0);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+TEST(TerminateOnResumeAtBreakOnEntryUserDefinedFunction) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    v8::Local<v8::Function> foo =
+        CompileFunction(&env, "function foo(b) { while (b > 0) {} }", "foo");
+
+    // Run without breakpoints to compile source to bytecode.
+    CompileRun("foo(-1)");
+    CHECK_EQ(delegate.break_count(), 0);
+
+    SetBreakPoint(foo, 0);
+    v8::Local<v8::Value> val = CompileRun("foo(1)");
+    CHECK_EQ(delegate.break_count(), 1);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.exception_thrown_count(), 0);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+TEST(TerminateOnResumeAtUnhandledRejection) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  ChangeBreakOnException(true, true);
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    v8::Local<v8::Function> foo = CompileFunction(
+        &env, "async function foo() { Promise.reject(); while(true) {} }",
+        "foo");
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 0);
+    CHECK_EQ(delegate.exception_thrown_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+namespace {
+void RejectPromiseThroughCpp(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  auto data = reinterpret_cast<std::pair<v8::Isolate*, LocalContext*>*>(
+      info.Data().As<v8::External>()->Value());
+
+  v8::Local<v8::String> value1 =
+      v8::String::NewFromUtf8Literal(data->first, "foo");
+
+  v8::Local<v8::Promise::Resolver> resolver =
+      v8::Promise::Resolver::New(data->second->local()).ToLocalChecked();
+  v8::Local<v8::Promise> promise = resolver->GetPromise();
+  CHECK_EQ(promise->State(), v8::Promise::PromiseState::kPending);
+
+  resolver->Reject(data->second->local(), value1).ToChecked();
+  CHECK_EQ(promise->State(), v8::Promise::PromiseState::kRejected);
+  // CHECK_EQ(*v8::Utils::OpenHandle(*promise->Result()),
+  //         i::ReadOnlyRoots(CcTest::i_isolate()).exception());
+}
+}  // namespace
+
+TEST(TerminateOnResumeAtUnhandledRejectionCppImpl) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope scope(env->GetIsolate());
+  ChangeBreakOnException(true, true);
+  SetTerminateOnResumeDelegate delegate;
+  auto data = std::make_pair(isolate, &env);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  {
+    // We want to trigger a breapoint upon Promise rejection, but we will only
+    // get the callback if there is at least one JavaScript frame in the stack.
+    v8::Local<v8::Function> func =
+        v8::Function::New(env.local(), RejectPromiseThroughCpp,
+                          v8::External::New(isolate, &data))
+            .ToLocalChecked();
+    CHECK(env->Global()
+              ->Set(env.local(), v8_str("RejectPromiseThroughCpp"), func)
+              .FromJust());
+
+    CompileRun("RejectPromiseThroughCpp(); while (true) {}");
+    CHECK_EQ(delegate.break_count(), 0);
+    CHECK_EQ(delegate.exception_thrown_count(), 1);
+  }
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+namespace {
+static void UnreachableMicrotask(
+    const v8::FunctionCallbackInfo<v8::Value>& info) {
+  UNREACHABLE();
+}
+}  // namespace
+
+TEST(TerminateOnResumeFromMicrotask) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  SetTerminateOnResumeDelegate delegate(
+      SetTerminateOnResumeDelegate::kPerformMicrotaskCheckpointAtBreakpoint);
+  ChangeBreakOnException(true, true);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    // Enqueue a microtask that gets run while we are paused at the breakpoint.
+    v8::Local<v8::Function> foo = CompileFunction(
+        &env, "function foo(){ Promise.reject(); while (true) {} }", "foo");
+    env->GetIsolate()->EnqueueMicrotask(foo);
+    env->GetIsolate()->EnqueueMicrotask(
+        v8::Function::New(env.local(), UnreachableMicrotask).ToLocalChecked());
+
+    CHECK_EQ(2,
+             CcTest::i_isolate()->native_context()->microtask_queue()->size());
+
+    v8::MicrotasksScope::PerformCheckpoint(env->GetIsolate());
+
+    CHECK_EQ(0,
+             CcTest::i_isolate()->native_context()->microtask_queue()->size());
+
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 0);
+    CHECK_EQ(delegate.exception_thrown_count(), 1);
+  }
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+class FutexInterruptionThread : public v8::base::Thread {
+ public:
+  FutexInterruptionThread(v8::Isolate* isolate, v8::base::Semaphore* sem)
+      : Thread(Options("FutexInterruptionThread")),
+        isolate_(isolate),
+        sem_(sem) {}
+
+  void Run() override {
+    // Wait a bit before terminating.
+    v8::base::OS::Sleep(v8::base::TimeDelta::FromMilliseconds(100));
+    sem_->Wait();
+    v8::debug::SetTerminateOnResume(isolate_);
+  }
+
+ private:
+  v8::Isolate* isolate_;
+  v8::base::Semaphore* sem_;
+};
+
+namespace {
+class SemaphoreTriggerOnBreak : public v8::debug::DebugDelegate {
+ public:
+  SemaphoreTriggerOnBreak() : sem_(0) {}
+  void BreakProgramRequested(v8::Local<v8::Context> paused_context,
+                             const std::vector<v8::debug::BreakpointId>&
+                                 inspector_break_points_hit) override {
+    break_count_++;
+    sem_.Signal();
+  }
+
+  v8::base::Semaphore* semaphore() { return &sem_; }
+  int break_count() const { return break_count_; }
+
+ private:
+  v8::base::Semaphore sem_;
+  int break_count_ = 0;
+};
+}  // anonymous namespace
+
+TEST(TerminateOnResumeFromOtherThread) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  ChangeBreakOnException(true, true);
+
+  SemaphoreTriggerOnBreak delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+
+  FutexInterruptionThread timeout_thread(env->GetIsolate(),
+                                         delegate.semaphore());
+  CHECK(timeout_thread.Start());
+
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    const char* source = "debugger; while(true){};";
+
+    v8::ScriptCompiler::Source script_source(v8_str(source));
+    v8::Local<v8::Function> foo =
+        v8::ScriptCompiler::CompileFunctionInContext(
+            env.local(), &script_source, 0, nullptr, 0, nullptr)
+            .ToLocalChecked();
+
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
+
+namespace {
+class InterruptionBreakRightNow : public v8::base::Thread {
+ public:
+  explicit InterruptionBreakRightNow(v8::Isolate* isolate)
+      : Thread(Options("FutexInterruptionThread")), isolate_(isolate) {}
+
+  void Run() override {
+    // Wait a bit before terminating.
+    v8::base::OS::Sleep(v8::base::TimeDelta::FromMilliseconds(100));
+    isolate_->RequestInterrupt(BreakRightNow, nullptr);
+  }
+
+ private:
+  static void BreakRightNow(v8::Isolate* isolate, void* data) {
+    v8::debug::BreakRightNow(isolate);
+  }
+  v8::Isolate* isolate_;
+};
+
+}  // anonymous namespace
+
+TEST(TerminateOnResumeAtInterruptFromOtherThread) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  ChangeBreakOnException(true, true);
+
+  SetTerminateOnResumeDelegate delegate;
+  v8::debug::SetDebugDelegate(env->GetIsolate(), &delegate);
+
+  InterruptionBreakRightNow timeout_thread(env->GetIsolate());
+
+  v8::Local<v8::Context> context = env.local();
+  {
+    v8::TryCatch try_catch(env->GetIsolate());
+    const char* source = "while(true){}";
+
+    v8::ScriptCompiler::Source script_source(v8_str(source));
+    v8::Local<v8::Function> foo =
+        v8::ScriptCompiler::CompileFunctionInContext(
+            env.local(), &script_source, 0, nullptr, 0, nullptr)
+            .ToLocalChecked();
+
+    CHECK(timeout_thread.Start());
+    v8::MaybeLocal<v8::Value> val =
+        foo->Call(context, env->Global(), 0, nullptr);
+    CHECK(val.IsEmpty());
+    CHECK(try_catch.HasTerminated());
+    CHECK_EQ(delegate.break_count(), 1);
+  }
+  // Exiting the TryCatch brought the isolate back to a state where JavaScript
+  // can be executed.
+  ExpectInt32("1 + 1", 2);
+  v8::debug::SetDebugDelegate(env->GetIsolate(), nullptr);
+  CheckDebuggerUnloaded();
+}
diff --git a/deps/v8/test/cctest/test-decls.cc b/deps/v8/test/cctest/test-decls.cc
index 14c30cd362..e2b5772654 100644
--- a/deps/v8/test/cctest/test-decls.cc
+++ b/deps/v8/test/cctest/test-decls.cc
@@ -147,9 +147,7 @@ void DeclarationContext::Check(const char* source, int get, int set, int query,
   catcher.SetVerbose(true);
   Local<Context> context = CcTest::isolate()->GetCurrentContext();
   MaybeLocal<Script> script = Script::Compile(
-      context,
-      String::NewFromUtf8(CcTest::isolate(), source, v8::NewStringType::kNormal)
-          .ToLocalChecked());
+      context, String::NewFromUtf8(CcTest::isolate(), source).ToLocalChecked());
   if (expectations == EXPECT_ERROR) {
     CHECK(script.IsEmpty());
     return;
@@ -445,9 +443,8 @@ class SimpleContext {
     TryCatch catcher(context_->GetIsolate());
     catcher.SetVerbose(true);
     MaybeLocal<Script> script = Script::Compile(
-        context_, String::NewFromUtf8(context_->GetIsolate(), source,
-                                      v8::NewStringType::kNormal)
-                      .ToLocalChecked());
+        context_,
+        String::NewFromUtf8(context_->GetIsolate(), source).ToLocalChecked());
     if (expectations == EXPECT_ERROR) {
       CHECK(script.IsEmpty());
       return;
@@ -748,14 +745,10 @@ TEST(CrossScriptDynamicLookup) {
 
   {
     SimpleContext context;
-    Local<String> undefined_string =
-        String::NewFromUtf8(CcTest::isolate(), "undefined",
-                            v8::NewStringType::kInternalized)
-            .ToLocalChecked();
-    Local<String> number_string =
-        String::NewFromUtf8(CcTest::isolate(), "number",
-                            v8::NewStringType::kInternalized)
-            .ToLocalChecked();
+    Local<String> undefined_string = String::NewFromUtf8Literal(
+        CcTest::isolate(), "undefined", v8::NewStringType::kInternalized);
+    Local<String> number_string = String::NewFromUtf8Literal(
+        CcTest::isolate(), "number", v8::NewStringType::kInternalized);
 
     context.Check(
         "function f(o) { with(o) { return x; } }"
@@ -825,14 +818,10 @@ TEST(CrossScriptStaticLookupUndeclared) {
 
   {
     SimpleContext context;
-    Local<String> undefined_string =
-        String::NewFromUtf8(CcTest::isolate(), "undefined",
-                            v8::NewStringType::kInternalized)
-            .ToLocalChecked();
-    Local<String> number_string =
-        String::NewFromUtf8(CcTest::isolate(), "number",
-                            v8::NewStringType::kInternalized)
-            .ToLocalChecked();
+    Local<String> undefined_string = String::NewFromUtf8Literal(
+        CcTest::isolate(), "undefined", v8::NewStringType::kInternalized);
+    Local<String> number_string = String::NewFromUtf8Literal(
+        CcTest::isolate(), "number", v8::NewStringType::kInternalized);
 
     context.Check(
         "function f(o) { return x; }"
diff --git a/deps/v8/test/cctest/test-disasm-arm64.cc b/deps/v8/test/cctest/test-disasm-arm64.cc
index 2b46d7ed11..93a0c9a807 100644
--- a/deps/v8/test/cctest/test-disasm-arm64.cc
+++ b/deps/v8/test/cctest/test-disasm-arm64.cc
@@ -1874,11 +1874,45 @@ TEST_(system_msr) {
 
 
 TEST_(system_nop) {
-  SET_UP_ASM();
+  {
+    SET_UP_ASM();
+    COMPARE(nop(), "nop");
+    CLEANUP();
+  }
+  {
+    SET_UP_MASM();
+    COMPARE(Nop(), "nop");
+    CLEANUP();
+  }
+}
 
-  COMPARE(nop(), "nop");
+TEST_(bti) {
+  {
+    SET_UP_ASM();
 
-  CLEANUP();
+    COMPARE(bti(BranchTargetIdentifier::kBti), "bti");
+    COMPARE(bti(BranchTargetIdentifier::kBtiCall), "bti c");
+    COMPARE(bti(BranchTargetIdentifier::kBtiJump), "bti j");
+    COMPARE(bti(BranchTargetIdentifier::kBtiJumpCall), "bti jc");
+    COMPARE(hint(BTI), "bti");
+    COMPARE(hint(BTI_c), "bti c");
+    COMPARE(hint(BTI_j), "bti j");
+    COMPARE(hint(BTI_jc), "bti jc");
+
+    CLEANUP();
+  }
+
+  {
+    SET_UP_MASM();
+
+    Label dummy1, dummy2, dummy3, dummy4;
+    COMPARE(Bind(&dummy1, BranchTargetIdentifier::kBti), "bti");
+    COMPARE(Bind(&dummy2, BranchTargetIdentifier::kBtiCall), "bti c");
+    COMPARE(Bind(&dummy3, BranchTargetIdentifier::kBtiJump), "bti j");
+    COMPARE(Bind(&dummy4, BranchTargetIdentifier::kBtiJumpCall), "bti jc");
+
+    CLEANUP();
+  }
 }
 
 TEST(system_pauth) {
diff --git a/deps/v8/test/cctest/test-disasm-ia32.cc b/deps/v8/test/cctest/test-disasm-ia32.cc
index 686b1e122e..cc4f5cc296 100644
--- a/deps/v8/test/cctest/test-disasm-ia32.cc
+++ b/deps/v8/test/cctest/test-disasm-ia32.cc
@@ -592,6 +592,7 @@ TEST(DisasmIa320) {
     if (CpuFeatures::IsSupported(SSSE3)) {
       CpuFeatureScope scope(&assm, SSSE3);
       SSSE3_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
+      SSSE3_UNOP_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
       __ palignr(xmm5, xmm1, 5);
       __ palignr(xmm5, Operand(edx, 4), 5);
     }
@@ -802,6 +803,7 @@ TEST(DisasmIa320) {
   __ v##instruction(xmm5, xmm1);                                         \
   __ v##instruction(xmm5, Operand(edx, 4));
 
+      SSSE3_UNOP_INSTRUCTION_LIST(EMIT_SSE4_RM_AVXINSTR)
       SSE4_RM_INSTRUCTION_LIST(EMIT_SSE4_RM_AVXINSTR)
 #undef EMIT_SSE4_RM_AVXINSTR
     }
diff --git a/deps/v8/test/cctest/test-disasm-x64.cc b/deps/v8/test/cctest/test-disasm-x64.cc
index 5e85cb5a08..b9cf05bcc9 100644
--- a/deps/v8/test/cctest/test-disasm-x64.cc
+++ b/deps/v8/test/cctest/test-disasm-x64.cc
@@ -391,8 +391,6 @@ TEST(DisasmX64) {
     // Move operation
     __ cvttss2si(rdx, Operand(rbx, rcx, times_4, 10000));
     __ cvttss2si(rdx, xmm1);
-    __ cvtsd2ss(xmm0, xmm1);
-    __ cvtsd2ss(xmm0, Operand(rbx, rcx, times_4, 10000));
     __ cvttps2dq(xmm0, xmm1);
     __ cvttps2dq(xmm0, Operand(rbx, rcx, times_4, 10000));
     __ movaps(xmm0, xmm1);
@@ -437,13 +435,6 @@ TEST(DisasmX64) {
 
     __ ucomisd(xmm0, xmm1);
 
-    __ andpd(xmm0, xmm1);
-    __ andpd(xmm0, Operand(rbx, rcx, times_4, 10000));
-    __ orpd(xmm0, xmm1);
-    __ orpd(xmm0, Operand(rbx, rcx, times_4, 10000));
-    __ xorpd(xmm0, xmm1);
-    __ xorpd(xmm0, Operand(rbx, rcx, times_4, 10000));
-
     __ pcmpeqd(xmm1, xmm0);
 
     __ punpckldq(xmm1, xmm11);
@@ -458,6 +449,7 @@ TEST(DisasmX64) {
   __ instruction(xmm5, Operand(rdx, 4));
 
     SSE2_INSTRUCTION_LIST(EMIT_SSE2_INSTR)
+    SSE2_UNOP_INSTRUCTION_LIST(EMIT_SSE2_INSTR)
     SSE2_INSTRUCTION_LIST_SD(EMIT_SSE2_INSTR)
 #undef EMIT_SSE2_INSTR
 
@@ -514,6 +506,7 @@ TEST(DisasmX64) {
       __ palignr(xmm5, xmm1, 5);
       __ palignr(xmm5, Operand(rdx, 4), 5);
       SSSE3_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
+      SSSE3_UNOP_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
     }
   }
 
@@ -579,7 +572,7 @@ TEST(DisasmX64) {
       __ blendvpd(xmm5, Operand(rdx, 4));
 
       SSE4_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
-      SSE4_PMOV_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
+      SSE4_UNOP_INSTRUCTION_LIST(EMIT_SSE34_INSTR)
       SSE4_EXTRACT_INSTRUCTION_LIST(EMIT_SSE34_IMM_INSTR)
     }
   }
@@ -635,29 +628,14 @@ TEST(DisasmX64) {
       __ vmovdqu(xmm9, Operand(rbx, rcx, times_4, 10000));
       __ vmovdqu(Operand(rbx, rcx, times_4, 10000), xmm0);
 
-      __ vaddsd(xmm0, xmm1, xmm2);
-      __ vaddsd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
-      __ vmulsd(xmm0, xmm1, xmm2);
-      __ vmulsd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
-      __ vsubsd(xmm0, xmm1, xmm2);
-      __ vsubsd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
-      __ vdivsd(xmm0, xmm1, xmm2);
-      __ vdivsd(xmm0, xmm1, Operand(rbx, rcx, times_2, 10000));
-      __ vminsd(xmm8, xmm1, xmm2);
-      __ vminsd(xmm9, xmm1, Operand(rbx, rcx, times_8, 10000));
-      __ vmaxsd(xmm8, xmm1, xmm2);
-      __ vmaxsd(xmm9, xmm1, Operand(rbx, rcx, times_1, 10000));
       __ vroundss(xmm9, xmm1, xmm2, kRoundDown);
       __ vroundsd(xmm8, xmm3, xmm0, kRoundDown);
-      __ vsqrtsd(xmm8, xmm1, xmm2);
-      __ vsqrtsd(xmm9, xmm1, Operand(rbx, rcx, times_1, 10000));
       __ vucomisd(xmm9, xmm1);
       __ vucomisd(xmm8, Operand(rbx, rdx, times_2, 10981));
 
       __ vcvtss2sd(xmm4, xmm9, xmm11);
-      __ vcvtsd2ss(xmm9, xmm3, xmm2);
       __ vcvtss2sd(xmm4, xmm9, Operand(rbx, rcx, times_1, 10000));
-      __ vcvtsd2ss(xmm9, xmm3, Operand(rbx, rcx, times_1, 10000));
+      __ vcvttps2dq(xmm4, xmm11);
       __ vcvtlsi2sd(xmm5, xmm9, rcx);
       __ vcvtlsi2sd(xmm9, xmm3, Operand(rbx, r9, times_4, 10000));
       __ vcvtqsi2sd(xmm5, xmm9, r11);
@@ -687,13 +665,6 @@ TEST(DisasmX64) {
       __ vhaddps(xmm0, xmm1, xmm9);
       __ vhaddps(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
 
-      __ vandpd(xmm0, xmm9, xmm2);
-      __ vandpd(xmm9, xmm1, Operand(rbx, rcx, times_4, 10000));
-      __ vorpd(xmm0, xmm1, xmm9);
-      __ vorpd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
-      __ vxorpd(xmm0, xmm1, xmm9);
-      __ vxorpd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
-
       __ vpcmpeqd(xmm0, xmm15, xmm5);
       __ vpcmpeqd(xmm15, xmm0, Operand(rbx, rcx, times_4, 10000));
 
@@ -744,23 +715,44 @@ TEST(DisasmX64) {
   __ v##instruction(xmm10, xmm5, xmm1);                               \
   __ v##instruction(xmm10, xmm5, Operand(rdx, 4));
 
+      SSE2_INSTRUCTION_LIST(EMIT_SSE2_AVXINSTR)
+#undef EMIT_SSE2_AVXINSTR
+
+#define EMIT_SSE2_UNOP_AVXINSTR(instruction, notUsed1, notUsed2, notUsed3) \
+  __ v##instruction(xmm10, xmm1);                                          \
+  __ v##instruction(xmm10, Operand(rdx, 4));
+
+      SSE2_UNOP_INSTRUCTION_LIST(EMIT_SSE2_UNOP_AVXINSTR)
+#undef EMIT_SSE2_AVXINSTR
+
+#define EMIT_SSE2_SD_AVXINSTR(instruction, notUsed1, notUsed2, notUsed3) \
+  __ v##instruction(xmm10, xmm5, xmm1);                                  \
+  __ v##instruction(xmm10, xmm5, Operand(rbx, rcx, times_4, 10000));
+      SSE2_INSTRUCTION_LIST_SD(EMIT_SSE2_SD_AVXINSTR)
+#undef EMIT_SSE2_SD_AVXINSTR
+
 #define EMIT_SSE34_AVXINSTR(instruction, notUsed1, notUsed2, notUsed3, \
                             notUsed4)                                  \
   __ v##instruction(xmm10, xmm5, xmm1);                                \
   __ v##instruction(xmm10, xmm5, Operand(rdx, 4));
 
-      SSE2_INSTRUCTION_LIST(EMIT_SSE2_AVXINSTR)
       SSSE3_INSTRUCTION_LIST(EMIT_SSE34_AVXINSTR)
       SSE4_INSTRUCTION_LIST(EMIT_SSE34_AVXINSTR)
       SSE4_2_INSTRUCTION_LIST(EMIT_SSE34_AVXINSTR)
-#undef EMIT_SSE2_AVXINSTR
 #undef EMIT_SSE34_AVXINSTR
 
+#define EMIT_SSSE3_UNOP_AVXINSTR(instruction, notUsed1, notUsed2, notUsed3, \
+                                 notUsed4)                                  \
+  __ v##instruction(xmm9, xmm3);                                            \
+  __ v##instruction(xmm9, Operand(rdx, 5));
+      SSSE3_UNOP_INSTRUCTION_LIST(EMIT_SSSE3_UNOP_AVXINSTR)
+#undef EMIT_SSSE3_UNOP_AVXINSTR
+
 #define EMIT_SSE4_PMOV_AVXINSTR(instruction, notUsed1, notUsed2, notUsed3, \
                                 notUsed4)                                  \
   __ v##instruction(xmm10, xmm1);                                          \
   __ v##instruction(xmm10, Operand(rdx, 4));
-      SSE4_PMOV_INSTRUCTION_LIST(EMIT_SSE4_PMOV_AVXINSTR)
+      SSE4_UNOP_INSTRUCTION_LIST(EMIT_SSE4_PMOV_AVXINSTR)
 #undef EMIT_SSE4_PMOV_AVXINSTR
 
 #define EMIT_SSE2_SHIFT_IMM_AVX(instruction, notUsed1, notUsed2, notUsed3, \
@@ -791,8 +783,11 @@ TEST(DisasmX64) {
       __ vpinsrq(xmm1, xmm2, rax, 9);
       __ vpinsrq(xmm1, xmm2, Operand(rbx, rcx, times_4, 10000), 9);
       __ vpshufd(xmm1, xmm2, 85);
+      __ vpshufd(xmm1, Operand(rbx, rcx, times_4, 10000), 85);
       __ vpshuflw(xmm1, xmm2, 85);
       __ vpshuflw(xmm1, Operand(rbx, rcx, times_4, 10000), 85);
+      __ vpshufhw(xmm1, xmm2, 85);
+      __ vpshufhw(xmm1, Operand(rbx, rcx, times_4, 10000), 85);
       __ vshufps(xmm3, xmm2, xmm3, 3);
       __ vpblendw(xmm1, xmm2, xmm3, 23);
       __ vpblendw(xmm1, xmm2, Operand(rbx, rcx, times_4, 10000), 23);
diff --git a/deps/v8/test/cctest/test-factory.cc b/deps/v8/test/cctest/test-factory.cc
index 4ed7cb7bca..98823f1ec9 100644
--- a/deps/v8/test/cctest/test-factory.cc
+++ b/deps/v8/test/cctest/test-factory.cc
@@ -20,7 +20,8 @@ namespace {
 // This needs to be large enough to create a new nosnap Isolate, but smaller
 // than kMaximalCodeRangeSize so we can recover from the OOM.
 constexpr int kInstructionSize = 100 * MB;
-STATIC_ASSERT(kInstructionSize < kMaximalCodeRangeSize || !kRequiresCodeRange);
+STATIC_ASSERT(kInstructionSize < kMaximalCodeRangeSize ||
+              !kPlatformRequiresCodeRange);
 
 size_t NearHeapLimitCallback(void* raw_bool, size_t current_heap_limit,
                              size_t initial_heap_limit) {
diff --git a/deps/v8/test/cctest/test-feedback-vector.cc b/deps/v8/test/cctest/test-feedback-vector.cc
index 91db7e51a5..a15eeff133 100644
--- a/deps/v8/test/cctest/test-feedback-vector.cc
+++ b/deps/v8/test/cctest/test-feedback-vector.cc
@@ -216,6 +216,39 @@ TEST(VectorCallFeedback) {
   CHECK_EQ(MONOMORPHIC, nexus.ic_state());
 }
 
+TEST(VectorPolymorphicCallFeedback) {
+  if (!i::FLAG_use_ic) return;
+  if (i::FLAG_always_opt) return;
+  FLAG_allow_natives_syntax = true;
+  FLAG_lazy_feedback_allocation = false;
+
+  CcTest::InitializeVM();
+  LocalContext context;
+  v8::HandleScope scope(context->GetIsolate());
+  Isolate* isolate = CcTest::i_isolate();
+  // Make sure the call feedback of a() in f() becomes polymorphic.
+  CompileRun(
+      "function foo_maker() { return () => { return 17; } }"
+      "a_foo = foo_maker();"
+      "function f(a) { a(); } f(foo_maker());"
+      "f(foo_maker());");
+  Handle<JSFunction> f = GetFunction("f");
+  Handle<JSFunction> a_foo = GetFunction("a_foo");
+  // There should be one IC.
+  Handle<FeedbackVector> feedback_vector =
+      Handle<FeedbackVector>(f->feedback_vector(), isolate);
+  FeedbackSlot slot(0);
+  FeedbackNexus nexus(feedback_vector, slot);
+
+  CHECK_EQ(POLYMORPHIC, nexus.ic_state());
+  HeapObject heap_object;
+  CHECK(nexus.GetFeedback()->GetHeapObjectIfWeak(&heap_object));
+  CHECK(heap_object.IsFeedbackCell(isolate));
+  // Ensure this is the feedback cell for the closure returned by
+  // foo_maker.
+  CHECK_EQ(heap_object, a_foo->raw_feedback_cell());
+}
+
 TEST(VectorCallFeedbackForArray) {
   if (!i::FLAG_use_ic) return;
   if (i::FLAG_always_opt) return;
diff --git a/deps/v8/test/cctest/test-field-type-tracking.cc b/deps/v8/test/cctest/test-field-type-tracking.cc
index 9deb1ff70c..840478a520 100644
--- a/deps/v8/test/cctest/test-field-type-tracking.cc
+++ b/deps/v8/test/cctest/test-field-type-tracking.cc
@@ -11,7 +11,7 @@
 
 #include "src/execution/execution.h"
 #include "src/handles/global-handles.h"
-#include "src/heap/factory.h"
+#include "src/heap/factory-inl.h"
 #include "src/ic/stub-cache.h"
 #include "src/objects/field-type.h"
 #include "src/objects/heap-number-inl.h"
diff --git a/deps/v8/test/cctest/test-func-name-inference.cc b/deps/v8/test/cctest/test-func-name-inference.cc
index 73f302f691..ab210ae162 100644
--- a/deps/v8/test/cctest/test-func-name-inference.cc
+++ b/deps/v8/test/cctest/test-func-name-inference.cc
@@ -94,8 +94,7 @@ static void CheckFunctionName(v8::Local<v8::Script> script,
 static v8::Local<v8::Script> Compile(v8::Isolate* isolate, const char* src) {
   return v8::Script::Compile(
              isolate->GetCurrentContext(),
-             v8::String::NewFromUtf8(isolate, src, v8::NewStringType::kNormal)
-                 .ToLocalChecked())
+             v8::String::NewFromUtf8(isolate, src).ToLocalChecked())
       .ToLocalChecked();
 }
 
diff --git a/deps/v8/test/cctest/test-global-handles.cc b/deps/v8/test/cctest/test-global-handles.cc
index a3c8fb7bde..b4da8ce544 100644
--- a/deps/v8/test/cctest/test-global-handles.cc
+++ b/deps/v8/test/cctest/test-global-handles.cc
@@ -98,6 +98,15 @@ void ConstructJSObject(v8::Isolate* isolate, v8::Global<v8::Object>* global) {
   CHECK(!global->IsEmpty());
 }
 
+void ConstructJSObject(v8::Isolate* isolate,
+                       v8::TracedGlobal<v8::Object>* traced) {
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::Object> object(v8::Object::New(isolate));
+  CHECK(!object.IsEmpty());
+  *traced = v8::TracedGlobal<v8::Object>(isolate, object);
+  CHECK(!traced->IsEmpty());
+}
+
 template <typename HandleContainer>
 void ConstructJSApiObject(v8::Isolate* isolate, v8::Local<v8::Context> context,
                           HandleContainer* flag_and_persistent) {
@@ -437,10 +446,8 @@ TEST(TracedGlobalToJSApiObjectWithModifiedMapSurvivesScavenge) {
     // Create an API object which does not have the same map as constructor.
     auto function_template = FunctionTemplate::New(isolate);
     auto instance_t = function_template->InstanceTemplate();
-    instance_t->Set(
-        v8::String::NewFromUtf8(isolate, "a", NewStringType::kNormal)
-            .ToLocalChecked(),
-        v8::Number::New(isolate, 10));
+    instance_t->Set(v8::String::NewFromUtf8Literal(isolate, "a"),
+                    v8::Number::New(isolate, 10));
     auto function =
         function_template->GetFunction(context.local()).ToLocalChecked();
     auto i = function->NewInstance(context.local()).ToLocalChecked();
@@ -462,14 +469,10 @@ TEST(TracedGlobalTOJsApiObjectWithElementsSurvivesScavenge) {
     // Create an API object which has elements.
     auto function_template = FunctionTemplate::New(isolate);
     auto instance_t = function_template->InstanceTemplate();
-    instance_t->Set(
-        v8::String::NewFromUtf8(isolate, "1", NewStringType::kNormal)
-            .ToLocalChecked(),
-        v8::Number::New(isolate, 10));
-    instance_t->Set(
-        v8::String::NewFromUtf8(isolate, "2", NewStringType::kNormal)
-            .ToLocalChecked(),
-        v8::Number::New(isolate, 10));
+    instance_t->Set(v8::String::NewFromUtf8Literal(isolate, "1"),
+                    v8::Number::New(isolate, 10));
+    instance_t->Set(v8::String::NewFromUtf8Literal(isolate, "2"),
+                    v8::Number::New(isolate, 10));
     auto function =
         function_template->GetFunction(context.local()).ToLocalChecked();
     auto i = function->NewInstance(context.local()).ToLocalChecked();
@@ -667,5 +670,39 @@ TEST(MoveWeakGlobal) {
   InvokeMarkSweep();
 }
 
+TEST(TotalSizeRegularNode) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+  Isolate* i_isolate = CcTest::i_isolate();
+  v8::HandleScope scope(isolate);
+
+  v8::Global<v8::Object>* global = new Global<v8::Object>();
+  CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
+  ConstructJSObject(isolate, global);
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_GT(i_isolate->global_handles()->UsedSize(), 0);
+  delete global;
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
+}
+
+TEST(TotalSizeTracedNode) {
+  CcTest::InitializeVM();
+  v8::Isolate* isolate = CcTest::isolate();
+  Isolate* i_isolate = CcTest::i_isolate();
+  v8::HandleScope scope(isolate);
+
+  v8::TracedGlobal<v8::Object>* global = new TracedGlobal<v8::Object>();
+  CHECK_EQ(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
+  ConstructJSObject(isolate, global);
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_GT(i_isolate->global_handles()->UsedSize(), 0);
+  delete global;
+  CHECK_GT(i_isolate->global_handles()->TotalSize(), 0);
+  CHECK_EQ(i_isolate->global_handles()->UsedSize(), 0);
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/test-heap-profiler.cc b/deps/v8/test/cctest/test-heap-profiler.cc
index 4d70d66724..63c88ae9b2 100644
--- a/deps/v8/test/cctest/test-heap-profiler.cc
+++ b/deps/v8/test/cctest/test-heap-profiler.cc
@@ -4053,10 +4053,9 @@ TEST(WeakReference) {
 
   // Create a FeedbackVector.
   v8::Local<v8::Script> script =
-      v8::Script::Compile(isolate->GetCurrentContext(),
-                          v8::String::NewFromUtf8(isolate, "function foo() {}",
-                                                  v8::NewStringType::kNormal)
-                              .ToLocalChecked())
+      v8::Script::Compile(
+          isolate->GetCurrentContext(),
+          v8::String::NewFromUtf8Literal(isolate, "function foo() {}"))
           .ToLocalChecked();
   v8::MaybeLocal<v8::Value> value = script->Run(isolate->GetCurrentContext());
   CHECK(!value.IsEmpty());
diff --git a/deps/v8/test/cctest/test-icache.cc b/deps/v8/test/cctest/test-icache.cc
index 95cc3c7824..e8c89b7232 100644
--- a/deps/v8/test/cctest/test-icache.cc
+++ b/deps/v8/test/cctest/test-icache.cc
@@ -34,6 +34,7 @@ static void FloodWithInc(Isolate* isolate, TestingAssemblerBuffer* buffer) {
     __ addl(rax, Immediate(1));
   }
 #elif V8_TARGET_ARCH_ARM64
+  __ CodeEntry();
   for (int i = 0; i < kNumInstr; ++i) {
     __ Add(x0, x0, Operand(1));
   }
@@ -51,7 +52,7 @@ static void FloodWithInc(Isolate* isolate, TestingAssemblerBuffer* buffer) {
   for (int i = 0; i < kNumInstr; ++i) {
     __ Addu(v0, v0, Operand(1));
   }
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
   for (int i = 0; i < kNumInstr; ++i) {
     __ addi(r3, r3, Operand(1));
   }
@@ -73,6 +74,8 @@ static void FloodWithNop(Isolate* isolate, TestingAssemblerBuffer* buffer) {
   __ mov(eax, Operand(esp, kSystemPointerSize));
 #elif V8_TARGET_ARCH_X64
   __ movl(rax, arg_reg_1);
+#elif V8_TARGET_ARCH_ARM64
+  __ CodeEntry();
 #elif V8_TARGET_ARCH_MIPS
   __ mov(v0, a0);
 #elif V8_TARGET_ARCH_MIPS64
diff --git a/deps/v8/test/cctest/test-inspector.cc b/deps/v8/test/cctest/test-inspector.cc
index 2f7e8b1ea1..6dd2aefb9e 100644
--- a/deps/v8/test/cctest/test-inspector.cc
+++ b/deps/v8/test/cctest/test-inspector.cc
@@ -9,9 +9,7 @@
 #include "include/v8-inspector.h"
 #include "include/v8.h"
 #include "src/inspector/protocol/Runtime.h"
-#include "src/inspector/string-16.h"
 
-using v8_inspector::String16;
 using v8_inspector::StringBuffer;
 using v8_inspector::StringView;
 using v8_inspector::V8ContextInfo;
@@ -65,16 +63,3 @@ TEST(WrapInsideWrapOnInterrupt) {
   isolate->RequestInterrupt(&WrapOnInterrupt, session.get());
   session->wrapObject(env.local(), v8::Null(isolate), object_group_view, false);
 }
-
-TEST(String16EndianTest) {
-  const v8_inspector::UChar* expected =
-      reinterpret_cast<const v8_inspector::UChar*>(u"Hello, \U0001F30E.");
-  const uint16_t* utf16le = reinterpret_cast<const uint16_t*>(
-      "H\0e\0l\0l\0o\0,\0 \0\x3c\xd8\x0e\xdf.\0");  // Same text in UTF16LE
-                                                    // encoding
-
-  String16 utf16_str = String16::fromUTF16LE(utf16le, 10);
-  String16 expected_str = expected;
-
-  CHECK_EQ(utf16_str, expected_str);
-}
diff --git a/deps/v8/test/cctest/test-js-weak-refs.cc b/deps/v8/test/cctest/test-js-weak-refs.cc
index db43f46e71..6759c37128 100644
--- a/deps/v8/test/cctest/test-js-weak-refs.cc
+++ b/deps/v8/test/cctest/test-js-weak-refs.cc
@@ -16,23 +16,24 @@ namespace internal {
 
 namespace {
 
-Handle<JSFinalizationGroup> ConstructJSFinalizationGroup(Isolate* isolate) {
+Handle<JSFinalizationRegistry> ConstructJSFinalizationRegistry(
+    Isolate* isolate) {
   Factory* factory = isolate->factory();
-  Handle<String> finalization_group_name =
-      factory->NewStringFromStaticChars("FinalizationGroup");
+  Handle<String> finalization_registry_name =
+      factory->NewStringFromStaticChars("FinalizationRegistry");
   Handle<Object> global =
       handle(isolate->native_context()->global_object(), isolate);
-  Handle<JSFunction> finalization_group_fun = Handle<JSFunction>::cast(
-      Object::GetProperty(isolate, global, finalization_group_name)
+  Handle<JSFunction> finalization_registry_fun = Handle<JSFunction>::cast(
+      Object::GetProperty(isolate, global, finalization_registry_name)
           .ToHandleChecked());
-  auto finalization_group = Handle<JSFinalizationGroup>::cast(
-      JSObject::New(finalization_group_fun, finalization_group_fun,
+  auto finalization_registry = Handle<JSFinalizationRegistry>::cast(
+      JSObject::New(finalization_registry_fun, finalization_registry_fun,
                     Handle<AllocationSite>::null())
           .ToHandleChecked());
 #ifdef VERIFY_HEAP
-  finalization_group->JSFinalizationGroupVerify(isolate);
+  finalization_registry->JSFinalizationRegistryVerify(isolate);
 #endif  // VERIFY_HEAP
-  return finalization_group;
+  return finalization_registry;
 }
 
 Handle<JSWeakRef> ConstructJSWeakRef(Handle<JSReceiver> target,
@@ -64,27 +65,28 @@ Handle<JSObject> CreateKey(const char* key_prop_value, Isolate* isolate) {
   return key;
 }
 
-Handle<WeakCell> FinalizationGroupRegister(
-    Handle<JSFinalizationGroup> finalization_group, Handle<JSObject> target,
-    Handle<Object> holdings, Handle<Object> key, Isolate* isolate) {
-  JSFinalizationGroup::Register(finalization_group, target, holdings, key,
-                                isolate);
-  CHECK(finalization_group->active_cells().IsWeakCell());
+Handle<WeakCell> FinalizationRegistryRegister(
+    Handle<JSFinalizationRegistry> finalization_registry,
+    Handle<JSObject> target, Handle<Object> holdings, Handle<Object> key,
+    Isolate* isolate) {
+  JSFinalizationRegistry::Register(finalization_registry, target, holdings, key,
+                                   isolate);
+  CHECK(finalization_registry->active_cells().IsWeakCell());
   Handle<WeakCell> weak_cell =
-      handle(WeakCell::cast(finalization_group->active_cells()), isolate);
+      handle(WeakCell::cast(finalization_registry->active_cells()), isolate);
 #ifdef VERIFY_HEAP
   weak_cell->WeakCellVerify(isolate);
 #endif  // VERIFY_HEAP
   return weak_cell;
 }
 
-Handle<WeakCell> FinalizationGroupRegister(
-    Handle<JSFinalizationGroup> finalization_group, Handle<JSObject> target,
-    Isolate* isolate) {
+Handle<WeakCell> FinalizationRegistryRegister(
+    Handle<JSFinalizationRegistry> finalization_registry,
+    Handle<JSObject> target, Isolate* isolate) {
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
-  return FinalizationGroupRegister(finalization_group, target, undefined,
-                                   undefined, isolate);
+  return FinalizationRegistryRegister(finalization_registry, target, undefined,
+                                      undefined, isolate);
 }
 
 void NullifyWeakCell(Handle<WeakCell> weak_cell, Isolate* isolate) {
@@ -158,6 +160,17 @@ void VerifyWeakCellKeyChain(Isolate* isolate, SimpleNumberDictionary key_map,
   va_end(args);
 }
 
+Handle<JSWeakRef> MakeWeakRefAndKeepDuringJob(Isolate* isolate) {
+  HandleScope inner_scope(isolate);
+
+  Handle<JSObject> js_object =
+      isolate->factory()->NewJSObject(isolate->object_function());
+  Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(js_object, isolate);
+  isolate->heap()->KeepDuringJob(js_object);
+
+  return inner_scope.CloseAndEscape(inner_weak_ref);
+}
+
 }  // namespace
 
 TEST(TestRegister) {
@@ -166,36 +179,36 @@ TEST(TestRegister) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   // Register a weak reference and verify internal data structures.
   Handle<WeakCell> weak_cell1 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 1,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 1,
                       *weak_cell1);
   CHECK(weak_cell1->key_list_prev().IsUndefined(isolate));
   CHECK(weak_cell1->key_list_next().IsUndefined(isolate));
 
-  CHECK(finalization_group->cleared_cells().IsUndefined(isolate));
+  CHECK(finalization_registry->cleared_cells().IsUndefined(isolate));
 
   // No key was used during registration, key-based map stays uninitialized.
-  CHECK(finalization_group->key_map().IsUndefined(isolate));
+  CHECK(finalization_registry->key_map().IsUndefined(isolate));
 
   // Register another weak reference and verify internal data structures.
   Handle<WeakCell> weak_cell2 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 2,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 2,
                       *weak_cell2, *weak_cell1);
   CHECK(weak_cell2->key_list_prev().IsUndefined(isolate));
   CHECK(weak_cell2->key_list_next().IsUndefined(isolate));
 
-  CHECK(finalization_group->cleared_cells().IsUndefined(isolate));
-  CHECK(finalization_group->key_map().IsUndefined(isolate));
+  CHECK(finalization_registry->cleared_cells().IsUndefined(isolate));
+  CHECK(finalization_registry->key_map().IsUndefined(isolate));
 }
 
 TEST(TestRegisterWithKey) {
@@ -204,8 +217,8 @@ TEST(TestRegisterWithKey) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
@@ -215,36 +228,36 @@ TEST(TestRegisterWithKey) {
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
   // Register a weak reference with a key and verify internal data structures.
-  Handle<WeakCell> weak_cell1 = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1 = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 1, *weak_cell1);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 0);
   }
 
   // Register another weak reference with a different key and verify internal
   // data structures.
-  Handle<WeakCell> weak_cell2 = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2 = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
 
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 1, *weak_cell1);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 1, *weak_cell2);
   }
 
   // Register another weak reference with token1 and verify internal data
   // structures.
-  Handle<WeakCell> weak_cell3 = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell3 = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell3,
                            *weak_cell1);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 1, *weak_cell2);
@@ -257,29 +270,29 @@ TEST(TestWeakCellNullify1) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   Handle<WeakCell> weak_cell1 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
   Handle<WeakCell> weak_cell2 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
 
   // Nullify the first WeakCell and verify internal data structures.
   NullifyWeakCell(weak_cell1, isolate);
-  CHECK_EQ(finalization_group->active_cells(), *weak_cell2);
+  CHECK_EQ(finalization_registry->active_cells(), *weak_cell2);
   CHECK(weak_cell2->prev().IsUndefined(isolate));
   CHECK(weak_cell2->next().IsUndefined(isolate));
-  CHECK_EQ(finalization_group->cleared_cells(), *weak_cell1);
+  CHECK_EQ(finalization_registry->cleared_cells(), *weak_cell1);
   CHECK(weak_cell1->prev().IsUndefined(isolate));
   CHECK(weak_cell1->next().IsUndefined(isolate));
 
   // Nullify the second WeakCell and verify internal data structures.
   NullifyWeakCell(weak_cell2, isolate);
-  CHECK(finalization_group->active_cells().IsUndefined(isolate));
-  CHECK_EQ(finalization_group->cleared_cells(), *weak_cell2);
+  CHECK(finalization_registry->active_cells().IsUndefined(isolate));
+  CHECK_EQ(finalization_registry->cleared_cells(), *weak_cell2);
   CHECK_EQ(weak_cell2->next(), *weak_cell1);
   CHECK(weak_cell2->prev().IsUndefined(isolate));
   CHECK_EQ(weak_cell1->prev(), *weak_cell2);
@@ -292,92 +305,92 @@ TEST(TestWeakCellNullify2) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
   Handle<WeakCell> weak_cell1 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
   Handle<WeakCell> weak_cell2 =
-      FinalizationGroupRegister(finalization_group, js_object, isolate);
+      FinalizationRegistryRegister(finalization_registry, js_object, isolate);
 
   // Like TestWeakCellNullify1 but nullify the WeakCells in opposite order.
   NullifyWeakCell(weak_cell2, isolate);
-  CHECK_EQ(finalization_group->active_cells(), *weak_cell1);
+  CHECK_EQ(finalization_registry->active_cells(), *weak_cell1);
   CHECK(weak_cell1->prev().IsUndefined(isolate));
   CHECK(weak_cell1->next().IsUndefined(isolate));
-  CHECK_EQ(finalization_group->cleared_cells(), *weak_cell2);
+  CHECK_EQ(finalization_registry->cleared_cells(), *weak_cell2);
   CHECK(weak_cell2->prev().IsUndefined(isolate));
   CHECK(weak_cell2->next().IsUndefined(isolate));
 
   NullifyWeakCell(weak_cell1, isolate);
-  CHECK(finalization_group->active_cells().IsUndefined(isolate));
-  CHECK_EQ(finalization_group->cleared_cells(), *weak_cell1);
+  CHECK(finalization_registry->active_cells().IsUndefined(isolate));
+  CHECK_EQ(finalization_registry->cleared_cells(), *weak_cell1);
   CHECK_EQ(weak_cell1->next(), *weak_cell2);
   CHECK(weak_cell1->prev().IsUndefined(isolate));
   CHECK_EQ(weak_cell2->prev(), *weak_cell1);
   CHECK(weak_cell2->next().IsUndefined(isolate));
 }
 
-TEST(TestJSFinalizationGroupPopClearedCellHoldings1) {
+TEST(TestJSFinalizationRegistryPopClearedCellHoldings1) {
   FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   Factory* factory = isolate->factory();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
   Handle<Object> holdings1 = factory->NewStringFromAsciiChecked("holdings1");
-  Handle<WeakCell> weak_cell1 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings1, undefined, isolate);
+  Handle<WeakCell> weak_cell1 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings1, undefined, isolate);
   Handle<Object> holdings2 = factory->NewStringFromAsciiChecked("holdings2");
-  Handle<WeakCell> weak_cell2 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings2, undefined, isolate);
+  Handle<WeakCell> weak_cell2 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings2, undefined, isolate);
   Handle<Object> holdings3 = factory->NewStringFromAsciiChecked("holdings3");
-  Handle<WeakCell> weak_cell3 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings3, undefined, isolate);
+  Handle<WeakCell> weak_cell3 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings3, undefined, isolate);
 
   NullifyWeakCell(weak_cell2, isolate);
   NullifyWeakCell(weak_cell3, isolate);
 
-  CHECK(finalization_group->NeedsCleanup());
-  Object cleared1 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  CHECK(finalization_registry->NeedsCleanup());
+  Object cleared1 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared1, *holdings3);
   CHECK(weak_cell3->prev().IsUndefined(isolate));
   CHECK(weak_cell3->next().IsUndefined(isolate));
 
-  CHECK(finalization_group->NeedsCleanup());
-  Object cleared2 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  CHECK(finalization_registry->NeedsCleanup());
+  Object cleared2 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared2, *holdings2);
   CHECK(weak_cell2->prev().IsUndefined(isolate));
   CHECK(weak_cell2->next().IsUndefined(isolate));
 
-  CHECK(!finalization_group->NeedsCleanup());
+  CHECK(!finalization_registry->NeedsCleanup());
 
   NullifyWeakCell(weak_cell1, isolate);
 
-  CHECK(finalization_group->NeedsCleanup());
-  Object cleared3 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  CHECK(finalization_registry->NeedsCleanup());
+  Object cleared3 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared3, *holdings1);
   CHECK(weak_cell1->prev().IsUndefined(isolate));
   CHECK(weak_cell1->next().IsUndefined(isolate));
 
-  CHECK(!finalization_group->NeedsCleanup());
-  CHECK(finalization_group->active_cells().IsUndefined(isolate));
-  CHECK(finalization_group->cleared_cells().IsUndefined(isolate));
+  CHECK(!finalization_registry->NeedsCleanup());
+  CHECK(finalization_registry->active_cells().IsUndefined(isolate));
+  CHECK(finalization_registry->cleared_cells().IsUndefined(isolate));
 }
 
-TEST(TestJSFinalizationGroupPopClearedCellHoldings2) {
+TEST(TestJSFinalizationRegistryPopClearedCellHoldings2) {
   // Test that when all WeakCells for a key are popped, the key is removed from
   // the key map.
   FLAG_harmony_weak_refs = true;
@@ -386,18 +399,18 @@ TEST(TestJSFinalizationGroupPopClearedCellHoldings2) {
   Isolate* isolate = CcTest::i_isolate();
   Factory* factory = isolate->factory();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
   Handle<JSObject> token1 = CreateKey("token1", isolate);
 
   Handle<Object> holdings1 = factory->NewStringFromAsciiChecked("holdings1");
-  Handle<WeakCell> weak_cell1 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings1, token1, isolate);
+  Handle<WeakCell> weak_cell1 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings1, token1, isolate);
   Handle<Object> holdings2 = factory->NewStringFromAsciiChecked("holdings2");
-  Handle<WeakCell> weak_cell2 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings2, token1, isolate);
+  Handle<WeakCell> weak_cell2 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings2, token1, isolate);
 
   NullifyWeakCell(weak_cell1, isolate);
   NullifyWeakCell(weak_cell2, isolate);
@@ -406,28 +419,28 @@ TEST(TestJSFinalizationGroupPopClearedCellHoldings2) {
   // active_cells to cleared_cells).
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell2,
                            *weak_cell1);
   }
 
-  Object cleared1 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  Object cleared1 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared1, *holdings2);
 
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 1, *weak_cell1);
   }
 
-  Object cleared2 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  Object cleared2 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared2, *holdings1);
 
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
   }
 }
@@ -438,8 +451,8 @@ TEST(TestUnregisterActiveCells) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
@@ -448,41 +461,41 @@ TEST(TestUnregisterActiveCells) {
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
-  Handle<WeakCell> weak_cell1a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
-  Handle<WeakCell> weak_cell1b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
-  Handle<WeakCell> weak_cell2a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
-  Handle<WeakCell> weak_cell2b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 4,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 4,
                       *weak_cell2b, *weak_cell2a, *weak_cell1b, *weak_cell1a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell1b,
                            *weak_cell1a);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 2, *weak_cell2b,
                            *weak_cell2a);
   }
 
-  JSFinalizationGroup::Unregister(finalization_group, token1, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token1, isolate);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 2, *weak_cell2b,
                            *weak_cell2a);
   }
 
   // Both weak_cell1a and weak_cell1b removed from active_cells.
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 2,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 2,
                       *weak_cell2b, *weak_cell2a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
 }
 
 TEST(TestUnregisterActiveAndClearedCells) {
@@ -491,8 +504,8 @@ TEST(TestUnregisterActiveAndClearedCells) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
@@ -501,40 +514,40 @@ TEST(TestUnregisterActiveAndClearedCells) {
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
-  Handle<WeakCell> weak_cell1a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
-  Handle<WeakCell> weak_cell1b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
-  Handle<WeakCell> weak_cell2a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
-  Handle<WeakCell> weak_cell2b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
 
   NullifyWeakCell(weak_cell2a, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 3,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 3,
                       *weak_cell2b, *weak_cell1b, *weak_cell1a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 1,
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 1,
                       *weak_cell2a);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell1b,
                            *weak_cell1a);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 2, *weak_cell2b,
                            *weak_cell2a);
   }
 
-  JSFinalizationGroup::Unregister(finalization_group, token2, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token2, isolate);
 
   // Both weak_cell2a and weak_cell2b removed.
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 2,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 2,
                       *weak_cell1b, *weak_cell1a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell1b,
                            *weak_cell1a);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 0);
@@ -547,8 +560,8 @@ TEST(TestWeakCellUnregisterTwice) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
@@ -556,35 +569,35 @@ TEST(TestWeakCellUnregisterTwice) {
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
-  Handle<WeakCell> weak_cell1 = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1 = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 1,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 1,
                       *weak_cell1);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 1, *weak_cell1);
   }
 
-  JSFinalizationGroup::Unregister(finalization_group, token1, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token1, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 0);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
   }
 
-  JSFinalizationGroup::Unregister(finalization_group, token1, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token1, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 0);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
   }
 }
@@ -596,37 +609,37 @@ TEST(TestWeakCellUnregisterPopped) {
   Isolate* isolate = CcTest::i_isolate();
   Factory* factory = isolate->factory();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
   Handle<JSObject> token1 = CreateKey("token1", isolate);
   Handle<Object> holdings1 = factory->NewStringFromAsciiChecked("holdings1");
-  Handle<WeakCell> weak_cell1 = FinalizationGroupRegister(
-      finalization_group, js_object, holdings1, token1, isolate);
+  Handle<WeakCell> weak_cell1 = FinalizationRegistryRegister(
+      finalization_registry, js_object, holdings1, token1, isolate);
 
   NullifyWeakCell(weak_cell1, isolate);
 
-  CHECK(finalization_group->NeedsCleanup());
-  Object cleared1 =
-      JSFinalizationGroup::PopClearedCellHoldings(finalization_group, isolate);
+  CHECK(finalization_registry->NeedsCleanup());
+  Object cleared1 = JSFinalizationRegistry::PopClearedCellHoldings(
+      finalization_registry, isolate);
   CHECK_EQ(cleared1, *holdings1);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 0);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
   }
 
-  JSFinalizationGroup::Unregister(finalization_group, token1, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token1, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 0);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 0);
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 0);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 0);
   }
 }
@@ -637,11 +650,11 @@ TEST(TestWeakCellUnregisterNonexistentKey) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> token1 = CreateKey("token1", isolate);
 
-  JSFinalizationGroup::Unregister(finalization_group, token1, isolate);
+  JSFinalizationRegistry::Unregister(finalization_registry, token1, isolate);
 }
 
 TEST(TestJSWeakRef) {
@@ -715,30 +728,35 @@ TEST(TestJSWeakRefKeepDuringJob) {
   LocalContext context;
 
   Isolate* isolate = CcTest::i_isolate();
-  Heap* heap = isolate->heap();
   HandleScope outer_scope(isolate);
-  Handle<JSWeakRef> weak_ref;
-  {
-    HandleScope inner_scope(isolate);
-
-    Handle<JSObject> js_object =
-        isolate->factory()->NewJSObject(isolate->object_function());
-    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(js_object, isolate);
-    heap->KeepDuringJob(js_object);
+  Handle<JSWeakRef> weak_ref = MakeWeakRefAndKeepDuringJob(isolate);
+  CHECK(!weak_ref->target().IsUndefined(isolate));
+  CcTest::CollectAllGarbage();
+  CHECK(!weak_ref->target().IsUndefined(isolate));
 
-    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
-  }
+  // Clears the KeepDuringJob set.
+  context->GetIsolate()->ClearKeptObjects();
+  CcTest::CollectAllGarbage();
+  CHECK(weak_ref->target().IsUndefined(isolate));
 
+  weak_ref = MakeWeakRefAndKeepDuringJob(isolate);
+  CHECK(!weak_ref->target().IsUndefined(isolate));
+  CcTest::CollectAllGarbage();
   CHECK(!weak_ref->target().IsUndefined(isolate));
 
+  // ClearKeptObjects should be called by PerformMicrotasksCheckpoint.
+  CcTest::isolate()->PerformMicrotaskCheckpoint();
   CcTest::CollectAllGarbage();
+  CHECK(weak_ref->target().IsUndefined(isolate));
 
+  weak_ref = MakeWeakRefAndKeepDuringJob(isolate);
   CHECK(!weak_ref->target().IsUndefined(isolate));
-
-  // Clears the KeepDuringJob set.
-  context->GetIsolate()->ClearKeptObjects();
   CcTest::CollectAllGarbage();
+  CHECK(!weak_ref->target().IsUndefined(isolate));
 
+  // ClearKeptObjects should be called by MicrotasksScope::PerformCheckpoint.
+  v8::MicrotasksScope::PerformCheckpoint(CcTest::isolate());
+  CcTest::CollectAllGarbage();
   CHECK(weak_ref->target().IsUndefined(isolate));
 }
 
@@ -754,17 +772,7 @@ TEST(TestJSWeakRefKeepDuringJobIncrementalMarking) {
   Isolate* isolate = CcTest::i_isolate();
   Heap* heap = isolate->heap();
   HandleScope outer_scope(isolate);
-  Handle<JSWeakRef> weak_ref;
-  {
-    HandleScope inner_scope(isolate);
-
-    Handle<JSObject> js_object =
-        isolate->factory()->NewJSObject(isolate->object_function());
-    Handle<JSWeakRef> inner_weak_ref = ConstructJSWeakRef(js_object, isolate);
-    heap->KeepDuringJob(js_object);
-
-    weak_ref = inner_scope.CloseAndEscape(inner_weak_ref);
-  }
+  Handle<JSWeakRef> weak_ref = MakeWeakRefAndKeepDuringJob(isolate);
 
   CHECK(!weak_ref->target().IsUndefined(isolate));
 
@@ -787,8 +795,8 @@ TEST(TestRemoveUnregisterToken) {
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
   HandleScope outer_scope(isolate);
-  Handle<JSFinalizationGroup> finalization_group =
-      ConstructJSFinalizationGroup(isolate);
+  Handle<JSFinalizationRegistry> finalization_registry =
+      ConstructJSFinalizationRegistry(isolate);
   Handle<JSObject> js_object =
       isolate->factory()->NewJSObject(isolate->object_function());
 
@@ -797,32 +805,32 @@ TEST(TestRemoveUnregisterToken) {
   Handle<Object> undefined =
       handle(ReadOnlyRoots(isolate).undefined_value(), isolate);
 
-  Handle<WeakCell> weak_cell1a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
-  Handle<WeakCell> weak_cell1b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
+  Handle<WeakCell> weak_cell1b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token1, isolate);
 
-  Handle<WeakCell> weak_cell2a = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
-  Handle<WeakCell> weak_cell2b = FinalizationGroupRegister(
-      finalization_group, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2a = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
+  Handle<WeakCell> weak_cell2b = FinalizationRegistryRegister(
+      finalization_registry, js_object, undefined, token2, isolate);
 
   NullifyWeakCell(weak_cell2a, isolate);
 
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 3,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 3,
                       *weak_cell2b, *weak_cell1b, *weak_cell1a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 1,
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 1,
                       *weak_cell2a);
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell1b,
                            *weak_cell1a);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 2, *weak_cell2b,
                            *weak_cell2a);
   }
 
-  finalization_group->RemoveUnregisterToken(
+  finalization_registry->RemoveUnregisterToken(
       JSReceiver::cast(*token2), isolate,
       [undefined](WeakCell matched_cell) {
         matched_cell.set_unregister_token(*undefined);
@@ -830,15 +838,15 @@ TEST(TestRemoveUnregisterToken) {
       [](HeapObject, ObjectSlot, Object) {});
 
   // Both weak_cell2a and weak_cell2b remain on the weak cell chains.
-  VerifyWeakCellChain(isolate, finalization_group->active_cells(), 3,
+  VerifyWeakCellChain(isolate, finalization_registry->active_cells(), 3,
                       *weak_cell2b, *weak_cell1b, *weak_cell1a);
-  VerifyWeakCellChain(isolate, finalization_group->cleared_cells(), 1,
+  VerifyWeakCellChain(isolate, finalization_registry->cleared_cells(), 1,
                       *weak_cell2a);
 
   // But both weak_cell2a and weak_cell2b are removed from the key chain.
   {
     SimpleNumberDictionary key_map =
-        SimpleNumberDictionary::cast(finalization_group->key_map());
+        SimpleNumberDictionary::cast(finalization_registry->key_map());
     VerifyWeakCellKeyChain(isolate, key_map, *token1, 2, *weak_cell1b,
                            *weak_cell1a);
     VerifyWeakCellKeyChain(isolate, key_map, *token2, 0);
diff --git a/deps/v8/test/cctest/test-local-handles.cc b/deps/v8/test/cctest/test-local-handles.cc
new file mode 100644
index 0000000000..0e4fc5c7d1
--- /dev/null
+++ b/deps/v8/test/cctest/test-local-handles.cc
@@ -0,0 +1,96 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <memory>
+
+#include "src/api/api.h"
+#include "src/base/platform/condition-variable.h"
+#include "src/base/platform/mutex.h"
+#include "src/base/platform/semaphore.h"
+#include "src/handles/handles-inl.h"
+#include "src/handles/local-handles-inl.h"
+#include "src/heap/heap.h"
+#include "src/heap/local-heap.h"
+#include "src/heap/safepoint.h"
+#include "src/objects/heap-number.h"
+#include "test/cctest/cctest.h"
+#include "test/cctest/heap/heap-utils.h"
+
+namespace v8 {
+namespace internal {
+
+class LocalHandlesThread final : public v8::base::Thread {
+ public:
+  LocalHandlesThread(Heap* heap, Address object, base::Semaphore* sema_started,
+                     base::Semaphore* sema_gc_finished)
+      : v8::base::Thread(base::Thread::Options("ThreadWithLocalHeap")),
+        heap_(heap),
+        object_(object),
+        sema_started_(sema_started),
+        sema_gc_finished_(sema_gc_finished) {}
+
+  void Run() override {
+    LocalHeap local_heap(heap_);
+    LocalHandleScope scope(&local_heap);
+
+    static constexpr int kNumHandles =
+        kHandleBlockSize * 2 + kHandleBlockSize / 2;
+
+    std::vector<Handle<HeapNumber>> handles;
+    handles.reserve(kNumHandles);
+
+    for (int i = 0; i < kNumHandles; i++) {
+      Handle<HeapNumber> number = handle(
+          HeapNumber::cast(HeapObject::FromAddress(object_)), &local_heap);
+      handles.push_back(number);
+    }
+
+    sema_started_->Signal();
+
+    {
+      ParkedScope scope(&local_heap);
+      sema_gc_finished_->Wait();
+    }
+
+    for (Handle<HeapNumber> handle : handles) {
+      CHECK_EQ(42.0, handle->value());
+    }
+  }
+
+  Heap* heap_;
+  Address object_;
+  base::Semaphore* sema_started_;
+  base::Semaphore* sema_gc_finished_;
+};
+
+TEST(CreateLocalHandles) {
+  CcTest::InitializeVM();
+  FLAG_local_heaps = true;
+  Isolate* isolate = CcTest::i_isolate();
+
+  Address object = kNullAddress;
+
+  {
+    HandleScope handle_scope(isolate);
+    Handle<HeapNumber> number = isolate->factory()->NewHeapNumber(42.0);
+    object = (*number).address();
+  }
+
+  base::Semaphore sema_started(0);
+  base::Semaphore sema_gc_finished(0);
+
+  std::unique_ptr<LocalHandlesThread> thread(new LocalHandlesThread(
+      isolate->heap(), object, &sema_started, &sema_gc_finished));
+  CHECK(thread->Start());
+
+  sema_started.Wait();
+
+  CcTest::CollectAllGarbage();
+  sema_gc_finished.Signal();
+
+  thread->Join();
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/test/cctest/test-log.cc b/deps/v8/test/cctest/test-log.cc
index 80a6530dd7..5531b7ec95 100644
--- a/deps/v8/test/cctest/test-log.cc
+++ b/deps/v8/test/cctest/test-log.cc
@@ -306,9 +306,7 @@ TEST(Issue23768) {
           .ToLocalChecked();
   // Script needs to have a name in order to trigger InitLineEnds execution.
   v8::Local<v8::String> origin =
-      v8::String::NewFromUtf8(CcTest::isolate(), "issue-23768-test",
-                              v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromUtf8Literal(CcTest::isolate(), "issue-23768-test");
   v8::Local<v8::Script> evil_script =
       CompileWithOrigin(source, origin, v8_bool(false));
   CHECK(!evil_script.IsEmpty());
@@ -567,7 +565,7 @@ UNINITIALIZED_TEST(LogAll) {
   isolate->Dispose();
 }
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
 UNINITIALIZED_TEST(LogInterpretedFramesNativeStack) {
   SETUP_FLAGS();
   i::FLAG_interpreted_frames_native_stack = true;
@@ -652,7 +650,7 @@ UNINITIALIZED_TEST(LogInterpretedFramesNativeStackWithSerialization) {
   } while (!has_cache);
   delete cache;
 }
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
 UNINITIALIZED_TEST(ExternalCodeEventListener) {
   i::FLAG_log = false;
@@ -755,7 +753,7 @@ UNINITIALIZED_TEST(ExternalCodeEventListenerInnerFunctions) {
   isolate2->Dispose();
 }
 
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
 UNINITIALIZED_TEST(ExternalCodeEventListenerWithInterpretedFramesNativeStack) {
   i::FLAG_log = false;
   i::FLAG_prof = false;
@@ -805,7 +803,7 @@ UNINITIALIZED_TEST(ExternalCodeEventListenerWithInterpretedFramesNativeStack) {
   }
   isolate->Dispose();
 }
-#endif  // V8_TARGET_ARCH_ARM
+#endif  // !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_S390X
 
 UNINITIALIZED_TEST(TraceMaps) {
   SETUP_FLAGS();
diff --git a/deps/v8/test/cctest/test-modules.cc b/deps/v8/test/cctest/test-modules.cc
index 3d668360bd..13c6a3b7a8 100644
--- a/deps/v8/test/cctest/test-modules.cc
+++ b/deps/v8/test/cctest/test-modules.cc
@@ -45,147 +45,160 @@ MaybeLocal<Module> ResolveCallback(Local<Context> context,
 }
 
 TEST(ModuleInstantiationFailures1) {
-  Isolate* isolate = CcTest::isolate();
-  HandleScope scope(isolate);
-  LocalContext env;
-  v8::TryCatch try_catch(isolate);
+  bool prev_top_level_await = i::FLAG_harmony_top_level_await;
+  for (auto top_level_await : {true, false}) {
+    i::FLAG_harmony_top_level_await = top_level_await;
+    Isolate* isolate = CcTest::isolate();
+    HandleScope scope(isolate);
+    LocalContext env;
+    v8::TryCatch try_catch(isolate);
 
-  Local<Module> module;
-  {
-    Local<String> source_text = v8_str(
-        "import './foo.js';\n"
-        "export {} from './bar.js';");
-    ScriptOrigin origin = ModuleOrigin(v8_str("file.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    module = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-    CHECK_EQ(Module::kUninstantiated, module->GetStatus());
-    CHECK_EQ(2, module->GetModuleRequestsLength());
-    CHECK(v8_str("./foo.js")->StrictEquals(module->GetModuleRequest(0)));
-    v8::Location loc = module->GetModuleRequestLocation(0);
-    CHECK_EQ(0, loc.GetLineNumber());
-    CHECK_EQ(7, loc.GetColumnNumber());
-    CHECK(v8_str("./bar.js")->StrictEquals(module->GetModuleRequest(1)));
-    loc = module->GetModuleRequestLocation(1);
-    CHECK_EQ(1, loc.GetLineNumber());
-    CHECK_EQ(15, loc.GetColumnNumber());
-  }
+    Local<Module> module;
+    {
+      Local<String> source_text = v8_str(
+          "import './foo.js';\n"
+          "export {} from './bar.js';");
+      ScriptOrigin origin = ModuleOrigin(v8_str("file.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      module = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+      CHECK_EQ(Module::kUninstantiated, module->GetStatus());
+      CHECK_EQ(2, module->GetModuleRequestsLength());
+      CHECK(v8_str("./foo.js")->StrictEquals(module->GetModuleRequest(0)));
+      v8::Location loc = module->GetModuleRequestLocation(0);
+      CHECK_EQ(0, loc.GetLineNumber());
+      CHECK_EQ(7, loc.GetColumnNumber());
+      CHECK(v8_str("./bar.js")->StrictEquals(module->GetModuleRequest(1)));
+      loc = module->GetModuleRequestLocation(1);
+      CHECK_EQ(1, loc.GetLineNumber());
+      CHECK_EQ(15, loc.GetColumnNumber());
+    }
 
-  // Instantiation should fail.
-  {
-    v8::TryCatch inner_try_catch(isolate);
-    CHECK(module->InstantiateModule(env.local(), ResolveCallback).IsNothing());
-    CHECK(inner_try_catch.HasCaught());
-    CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
-    CHECK_EQ(Module::kUninstantiated, module->GetStatus());
-  }
+    // Instantiation should fail.
+    {
+      v8::TryCatch inner_try_catch(isolate);
+      CHECK(
+          module->InstantiateModule(env.local(), ResolveCallback).IsNothing());
+      CHECK(inner_try_catch.HasCaught());
+      CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
+      CHECK_EQ(Module::kUninstantiated, module->GetStatus());
+    }
 
-  // Start over again...
-  {
-    Local<String> source_text = v8_str(
-        "import './dep1.js';\n"
-        "export {} from './bar.js';");
-    ScriptOrigin origin = ModuleOrigin(v8_str("file.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    module = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    // Start over again...
+    {
+      Local<String> source_text = v8_str(
+          "import './dep1.js';\n"
+          "export {} from './bar.js';");
+      ScriptOrigin origin = ModuleOrigin(v8_str("file.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      module = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  // dep1.js
-  {
-    Local<String> source_text = v8_str("");
-    ScriptOrigin origin = ModuleOrigin(v8_str("dep1.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    dep1 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    // dep1.js
+    {
+      Local<String> source_text = v8_str("");
+      ScriptOrigin origin = ModuleOrigin(v8_str("dep1.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      dep1 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  // Instantiation should fail because a sub-module fails to resolve.
-  {
-    v8::TryCatch inner_try_catch(isolate);
-    CHECK(module->InstantiateModule(env.local(), ResolveCallback).IsNothing());
-    CHECK(inner_try_catch.HasCaught());
-    CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
-    CHECK_EQ(Module::kUninstantiated, module->GetStatus());
-  }
+    // Instantiation should fail because a sub-module fails to resolve.
+    {
+      v8::TryCatch inner_try_catch(isolate);
+      CHECK(
+          module->InstantiateModule(env.local(), ResolveCallback).IsNothing());
+      CHECK(inner_try_catch.HasCaught());
+      CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
+      CHECK_EQ(Module::kUninstantiated, module->GetStatus());
+    }
 
-  CHECK(!try_catch.HasCaught());
+    CHECK(!try_catch.HasCaught());
+  }
+  i::FLAG_harmony_top_level_await = prev_top_level_await;
 }
 
 TEST(ModuleInstantiationFailures2) {
-  Isolate* isolate = CcTest::isolate();
-  HandleScope scope(isolate);
-  LocalContext env;
-  v8::TryCatch try_catch(isolate);
+  bool prev_top_level_await = i::FLAG_harmony_top_level_await;
+  for (auto top_level_await : {true, false}) {
+    i::FLAG_harmony_top_level_await = top_level_await;
 
-  // root1.js
-  Local<Module> root;
-  {
-    Local<String> source_text =
-        v8_str("import './dep1.js'; import './dep2.js'");
-    ScriptOrigin origin = ModuleOrigin(v8_str("root1.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    root = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    Isolate* isolate = CcTest::isolate();
+    HandleScope scope(isolate);
+    LocalContext env;
+    v8::TryCatch try_catch(isolate);
 
-  // dep1.js
-  {
-    Local<String> source_text = v8_str("export let x = 42");
-    ScriptOrigin origin = ModuleOrigin(v8_str("dep1.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    dep1 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    // root1.js
+    Local<Module> root;
+    {
+      Local<String> source_text =
+          v8_str("import './dep1.js'; import './dep2.js'");
+      ScriptOrigin origin = ModuleOrigin(v8_str("root1.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      root = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  // dep2.js
-  {
-    Local<String> source_text = v8_str("import {foo} from './dep3.js'");
-    ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    // dep1.js
+    {
+      Local<String> source_text = v8_str("export let x = 42");
+      ScriptOrigin origin = ModuleOrigin(v8_str("dep1.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      dep1 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  {
-    v8::TryCatch inner_try_catch(isolate);
-    CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
-    CHECK(inner_try_catch.HasCaught());
-    CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
-    CHECK_EQ(Module::kUninstantiated, root->GetStatus());
-    CHECK_EQ(Module::kUninstantiated, dep1->GetStatus());
-    CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
-  }
+    // dep2.js
+    {
+      Local<String> source_text = v8_str("import {foo} from './dep3.js'");
+      ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  // Change dep2.js
-  {
-    Local<String> source_text = v8_str("import {foo} from './dep2.js'");
-    ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    {
+      v8::TryCatch inner_try_catch(isolate);
+      CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
+      CHECK(inner_try_catch.HasCaught());
+      CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
+      CHECK_EQ(Module::kUninstantiated, root->GetStatus());
+      CHECK_EQ(Module::kUninstantiated, dep1->GetStatus());
+      CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
+    }
 
-  {
-    v8::TryCatch inner_try_catch(isolate);
-    CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
-    CHECK(inner_try_catch.HasCaught());
-    CHECK(!inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
-    CHECK_EQ(Module::kUninstantiated, root->GetStatus());
-    CHECK_EQ(Module::kInstantiated, dep1->GetStatus());
-    CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
-  }
+    // Change dep2.js
+    {
+      Local<String> source_text = v8_str("import {foo} from './dep2.js'");
+      ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
 
-  // Change dep2.js again
-  {
-    Local<String> source_text = v8_str("import {foo} from './dep3.js'");
-    ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
-    ScriptCompiler::Source source(source_text, origin);
-    dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
-  }
+    {
+      v8::TryCatch inner_try_catch(isolate);
+      CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
+      CHECK(inner_try_catch.HasCaught());
+      CHECK(!inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
+      CHECK_EQ(Module::kUninstantiated, root->GetStatus());
+      CHECK_EQ(Module::kInstantiated, dep1->GetStatus());
+      CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
+    }
 
-  {
-    v8::TryCatch inner_try_catch(isolate);
-    CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
-    CHECK(inner_try_catch.HasCaught());
-    CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
-    CHECK_EQ(Module::kUninstantiated, root->GetStatus());
-    CHECK_EQ(Module::kInstantiated, dep1->GetStatus());
-    CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
+    // Change dep2.js again
+    {
+      Local<String> source_text = v8_str("import {foo} from './dep3.js'");
+      ScriptOrigin origin = ModuleOrigin(v8_str("dep2.js"), CcTest::isolate());
+      ScriptCompiler::Source source(source_text, origin);
+      dep2 = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+    }
+
+    {
+      v8::TryCatch inner_try_catch(isolate);
+      CHECK(root->InstantiateModule(env.local(), ResolveCallback).IsNothing());
+      CHECK(inner_try_catch.HasCaught());
+      CHECK(inner_try_catch.Exception()->StrictEquals(v8_str("boom")));
+      CHECK_EQ(Module::kUninstantiated, root->GetStatus());
+      CHECK_EQ(Module::kInstantiated, dep1->GetStatus());
+      CHECK_EQ(Module::kUninstantiated, dep2->GetStatus());
+    }
   }
+  i::FLAG_harmony_top_level_await = prev_top_level_await;
 }
 
 static MaybeLocal<Module> CompileSpecifierAsModuleResolveCallback(
@@ -726,7 +739,7 @@ TEST(ModuleEvaluationTopLevelAwaitError) {
     CHECK(promise->Result()->StrictEquals(v8_str("boom")));
     CHECK(module->GetException()->StrictEquals(v8_str("boom")));
 
-    // TODO(joshualitt) I am not sure, but this might not be supposed to throw
+    // TODO(cbruni) I am not sure, but this might not be supposed to throw
     // because it is async.
     CHECK(!try_catch.HasCaught());
   }
@@ -830,7 +843,7 @@ TEST(ModuleEvaluationTopLevelAwaitDynamicImport) {
     CHECK_EQ(promise->State(), v8::Promise::kPending);
     CHECK(!try_catch.HasCaught());
 
-    isolate->RunMicrotasks();
+    isolate->PerformMicrotaskCheckpoint();
     CHECK_EQ(promise->State(), v8::Promise::kFulfilled);
   }
   i::FLAG_harmony_top_level_await = previous_top_level_await_flag_value;
@@ -874,7 +887,7 @@ TEST(ModuleEvaluationTopLevelAwaitDynamicImportError) {
     CHECK_EQ(promise->State(), v8::Promise::kPending);
     CHECK(!try_catch.HasCaught());
 
-    isolate->RunMicrotasks();
+    isolate->PerformMicrotaskCheckpoint();
     CHECK_EQ(Module::kErrored, module->GetStatus());
     CHECK_EQ(promise->State(), v8::Promise::kRejected);
     CHECK(promise->Result()->StrictEquals(v8_str("boom")));
diff --git a/deps/v8/test/cctest/test-object.cc b/deps/v8/test/cctest/test-object.cc
index 9104e850db..04e47eb7bd 100644
--- a/deps/v8/test/cctest/test-object.cc
+++ b/deps/v8/test/cctest/test-object.cc
@@ -255,6 +255,29 @@ TEST(EnumCache) {
   }
 }
 
+TEST(ObjectMethodsThatTruncateMinusZero) {
+  LocalContext env;
+  Isolate* isolate = CcTest::i_isolate();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(env->GetIsolate());
+
+  Handle<Object> minus_zero = factory->NewNumber(-1.0 * 0.0);
+  CHECK(minus_zero->IsMinusZero());
+
+  Handle<Object> result =
+      Object::ToInteger(isolate, minus_zero).ToHandleChecked();
+  CHECK(result->IsZero());
+
+  result = Object::ToLength(isolate, minus_zero).ToHandleChecked();
+  CHECK(result->IsZero());
+
+  // Choose an error message template, doesn't matter which.
+  result = Object::ToIndex(isolate, minus_zero,
+                           MessageTemplate::kInvalidAtomicAccessIndex)
+               .ToHandleChecked();
+  CHECK(result->IsZero());
+}
+
 #define TEST_FUNCTION_KIND(Name)                                \
   TEST(Name) {                                                  \
     for (int i = 0; i < FunctionKind::kLastFunctionKind; i++) { \
diff --git a/deps/v8/test/cctest/test-orderedhashtable.cc b/deps/v8/test/cctest/test-orderedhashtable.cc
index 189f950b2e..f3887bdacd 100644
--- a/deps/v8/test/cctest/test-orderedhashtable.cc
+++ b/deps/v8/test/cctest/test-orderedhashtable.cc
@@ -1950,7 +1950,7 @@ TEST(OrderedNameDictionarySetEntry) {
   Handle<String> other_value = isolate->factory()->InternalizeUtf8String("baz");
   PropertyDetails other_details =
       PropertyDetails(kAccessor, READ_ONLY, PropertyCellType::kNoCell);
-  dict->SetEntry(isolate, entry, *key, *other_value, other_details);
+  dict->SetEntry(entry, *key, *other_value, other_details);
 
   entry = dict->FindEntry(isolate, *key);
   CHECK_EQ(0, entry);
@@ -1995,7 +1995,7 @@ TEST(SmallOrderedNameDictionarySetEntry) {
   Handle<String> other_value = factory->InternalizeUtf8String("baz");
   PropertyDetails other_details =
       PropertyDetails(kAccessor, READ_ONLY, PropertyCellType::kNoCell);
-  dict->SetEntry(isolate, entry, *key, *other_value, other_details);
+  dict->SetEntry(entry, *key, *other_value, other_details);
 
   entry = dict->FindEntry(isolate, *key);
   CHECK_EQ(0, entry);
diff --git a/deps/v8/test/cctest/test-parsing.cc b/deps/v8/test/cctest/test-parsing.cc
index 2decf108ac..fd75f263ca 100644
--- a/deps/v8/test/cctest/test-parsing.cc
+++ b/deps/v8/test/cctest/test-parsing.cc
@@ -907,7 +907,7 @@ void TestScanRegExp(const char* re_source, const char* expected) {
       HashSeed(CcTest::i_isolate()));
   const i::AstRawString* current_symbol =
       scanner.CurrentSymbol(&ast_value_factory);
-  ast_value_factory.Internalize(CcTest::i_isolate()->factory());
+  ast_value_factory.Internalize(CcTest::i_isolate());
   i::Handle<i::String> val = current_symbol->string();
   i::DisallowHeapAllocation no_alloc;
   i::String::FlatContent content = val->GetFlatContent(no_alloc);
@@ -1061,7 +1061,7 @@ TEST(ScopeUsesArgumentsSuperThis) {
       info.set_allow_lazy_parsing(false);
       CHECK(i::parsing::ParseProgram(&info, script, isolate));
       CHECK(i::Rewriter::Rewrite(&info));
-      info.ast_value_factory()->Internalize(isolate->factory());
+      info.ast_value_factory()->Internalize(isolate);
       CHECK(i::DeclarationScope::Analyze(&info));
       i::DeclarationScope::AllocateScopeInfos(&info, isolate);
       CHECK_NOT_NULL(info.literal());
@@ -3214,15 +3214,11 @@ TEST(FuncNameInferrerTwoByte) {
   // Make it really non-Latin1 (replace the Xs with a non-Latin1 character).
   two_byte_source[14] = two_byte_source[78] = two_byte_name[6] = 0x010D;
   v8::Local<v8::String> source =
-      v8::String::NewFromTwoByte(isolate, two_byte_source,
-                                 v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromTwoByte(isolate, two_byte_source).ToLocalChecked();
   v8::Local<v8::Value> result = CompileRun(source);
   CHECK(result->IsString());
   v8::Local<v8::String> expected_name =
-      v8::String::NewFromTwoByte(isolate, two_byte_name,
-                                 v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromTwoByte(isolate, two_byte_name).ToLocalChecked();
   CHECK(result->Equals(isolate->GetCurrentContext(), expected_name).FromJust());
   i::DeleteArray(two_byte_source);
   i::DeleteArray(two_byte_name);
@@ -3243,40 +3239,17 @@ TEST(FuncNameInferrerEscaped) {
   // Fix to correspond to the non-ASCII name in two_byte_source.
   two_byte_name[6] = 0x010D;
   v8::Local<v8::String> source =
-      v8::String::NewFromTwoByte(isolate, two_byte_source,
-                                 v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromTwoByte(isolate, two_byte_source).ToLocalChecked();
   v8::Local<v8::Value> result = CompileRun(source);
   CHECK(result->IsString());
   v8::Local<v8::String> expected_name =
-      v8::String::NewFromTwoByte(isolate, two_byte_name,
-                                 v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromTwoByte(isolate, two_byte_name).ToLocalChecked();
   CHECK(result->Equals(isolate->GetCurrentContext(), expected_name).FromJust());
   i::DeleteArray(two_byte_source);
   i::DeleteArray(two_byte_name);
 }
 
 
-TEST(RegressionLazyFunctionWithErrorWithArg) {
-  // Test only applies when lazy parsing.
-  if (!i::FLAG_lazy) return;
-
-  // The bug occurred when a lazy function had an error which requires a
-  // parameter (such as "unknown label" here). The error message was processed
-  // before the AstValueFactory containing the error message string was
-  // internalized.
-  v8::Isolate* isolate = CcTest::isolate();
-  v8::HandleScope scope(isolate);
-  LocalContext env;
-  i::FLAG_lazy = true;
-  CompileRun("function this_is_lazy() {\n"
-             "  break p;\n"
-             "}\n"
-             "this_is_lazy();\n");
-}
-
-
 TEST(SerializationOfMaybeAssignmentFlag) {
   i::Isolate* isolate = CcTest::i_isolate();
   i::Factory* factory = isolate->factory();
@@ -3312,7 +3285,7 @@ TEST(SerializationOfMaybeAssignmentFlag) {
   i::AstValueFactory avf(&zone, isolate->ast_string_constants(),
                          HashSeed(isolate));
   const i::AstRawString* name = avf.GetOneByteString("result");
-  avf.Internalize(isolate->factory());
+  avf.Internalize(isolate);
   i::Handle<i::String> str = name->string();
   CHECK(str->IsInternalizedString());
   i::DeclarationScope* script_scope =
@@ -3362,7 +3335,7 @@ TEST(IfArgumentsArrayAccessedThenParametersMaybeAssigned) {
   i::AstValueFactory avf(&zone, isolate->ast_string_constants(),
                          HashSeed(isolate));
   const i::AstRawString* name_x = avf.GetOneByteString("x");
-  avf.Internalize(isolate->factory());
+  avf.Internalize(isolate);
 
   i::DeclarationScope* script_scope =
       new (&zone) i::DeclarationScope(&zone, &avf);
diff --git a/deps/v8/test/cctest/test-regexp.cc b/deps/v8/test/cctest/test-regexp.cc
index 907c89fa0c..ce916c9c7a 100644
--- a/deps/v8/test/cctest/test-regexp.cc
+++ b/deps/v8/test/cctest/test-regexp.cc
@@ -76,7 +76,7 @@ static void CheckParseEq(const char* input, const char* expected,
   CHECK(v8::internal::RegExpParser::ParseRegExp(CcTest::i_isolate(), &zone,
                                                 &reader, flags, &result));
   CHECK_NOT_NULL(result.tree);
-  CHECK(result.error.is_null());
+  CHECK(result.error == RegExpError::kNone);
   std::ostringstream os;
   result.tree->Print(os, &zone);
   if (strcmp(expected, os.str().c_str()) != 0) {
@@ -94,7 +94,7 @@ static bool CheckSimple(const char* input) {
   CHECK(v8::internal::RegExpParser::ParseRegExp(
       CcTest::i_isolate(), &zone, &reader, JSRegExp::kNone, &result));
   CHECK_NOT_NULL(result.tree);
-  CHECK(result.error.is_null());
+  CHECK(result.error == RegExpError::kNone);
   return result.simple;
 }
 
@@ -112,7 +112,7 @@ static MinMaxPair CheckMinMaxMatch(const char* input) {
   CHECK(v8::internal::RegExpParser::ParseRegExp(
       CcTest::i_isolate(), &zone, &reader, JSRegExp::kNone, &result));
   CHECK_NOT_NULL(result.tree);
-  CHECK(result.error.is_null());
+  CHECK(result.error == RegExpError::kNone);
   int min_match = result.tree->min_match();
   int max_match = result.tree->max_match();
   MinMaxPair pair = { min_match, max_match };
@@ -428,9 +428,8 @@ static void ExpectError(const char* input, const char* expected,
   CHECK(!v8::internal::RegExpParser::ParseRegExp(isolate, &zone, &reader, flags,
                                                  &result));
   CHECK_NULL(result.tree);
-  CHECK(!result.error.is_null());
-  std::unique_ptr<char[]> str = result.error->ToCString(ALLOW_NULLS);
-  CHECK_EQ(0, strcmp(expected, str.get()));
+  CHECK(result.error != RegExpError::kNone);
+  CHECK_EQ(0, strcmp(expected, RegExpErrorString(result.error)));
 }
 
 
@@ -468,7 +467,7 @@ TEST(Errors) {
   ExpectError("\\k<a", kInvalidCaptureName, true);
   const char* kDuplicateCaptureName = "Duplicate capture group name";
   ExpectError("(?<a>.)(?<a>.)", kDuplicateCaptureName, true);
-  const char* kInvalidUnicodeEscape = "Invalid Unicode escape sequence";
+  const char* kInvalidUnicodeEscape = "Invalid Unicode escape";
   ExpectError("(?<\\u{FISK}", kInvalidUnicodeEscape, true);
   const char* kInvalidCaptureReferenced = "Invalid named capture referenced";
   ExpectError("\\k<a>", kInvalidCaptureReferenced, true);
@@ -607,7 +606,7 @@ using ArchRegExpMacroAssembler = RegExpMacroAssemblerARM;
 using ArchRegExpMacroAssembler = RegExpMacroAssemblerARM64;
 #elif V8_TARGET_ARCH_S390
 using ArchRegExpMacroAssembler = RegExpMacroAssemblerS390;
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
 using ArchRegExpMacroAssembler = RegExpMacroAssemblerPPC;
 #elif V8_TARGET_ARCH_MIPS
 using ArchRegExpMacroAssembler = RegExpMacroAssemblerMIPS;
@@ -721,9 +720,9 @@ TEST(MacroAssemblerNativeSimple) {
   m.AdvanceCurrentPosition(3);
   m.PushBacktrack(&backtrack);
   m.Succeed();
-  m.Bind(&backtrack);
+  m.BindJumpTarget(&backtrack);
   m.Backtrack();
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.Fail();
 
   Handle<String> source = factory->NewStringFromStaticChars("^foo");
@@ -780,9 +779,9 @@ TEST(MacroAssemblerNativeSimpleUC16) {
   m.AdvanceCurrentPosition(3);
   m.PushBacktrack(&backtrack);
   m.Succeed();
-  m.Bind(&backtrack);
+  m.BindJumpTarget(&backtrack);
   m.Backtrack();
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.Fail();
 
   Handle<String> source = factory->NewStringFromStaticChars("^foo");
@@ -835,11 +834,11 @@ TEST(MacroAssemblerNativeBacktrack) {
   Label backtrack;
   m.LoadCurrentCharacter(10, &fail);
   m.Succeed();
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.PushBacktrack(&backtrack);
   m.LoadCurrentCharacter(10, nullptr);
   m.Succeed();
-  m.Bind(&backtrack);
+  m.BindJumpTarget(&backtrack);
   m.Fail();
 
   Handle<String> source = factory->NewStringFromStaticChars("..........");
@@ -967,7 +966,7 @@ TEST(MacroAssemblernativeAtStart) {
   m.CheckNotAtStart(0, &not_at_start);
   // Check that prevchar = '\n' and current = 'f'.
   m.CheckCharacter('\n', &newline);
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.Fail();
   m.Bind(&newline);
   m.LoadCurrentCharacter(0, &fail);
@@ -1021,16 +1020,16 @@ TEST(MacroAssemblerNativeBackRefNoCase) {
   m.WriteCurrentPositionToRegister(2, 0);
   m.AdvanceCurrentPosition(3);
   m.WriteCurrentPositionToRegister(3, 0);
-  m.CheckNotBackReferenceIgnoreCase(2, false, false, &fail);  // Match "AbC".
-  m.CheckNotBackReferenceIgnoreCase(2, false, false, &fail);  // Match "ABC".
+  m.CheckNotBackReferenceIgnoreCase(2, false, &fail);  // Match "AbC".
+  m.CheckNotBackReferenceIgnoreCase(2, false, &fail);  // Match "ABC".
   Label expected_fail;
-  m.CheckNotBackReferenceIgnoreCase(2, false, false, &expected_fail);
-  m.Bind(&fail);
+  m.CheckNotBackReferenceIgnoreCase(2, false, &expected_fail);
+  m.BindJumpTarget(&fail);
   m.Fail();
 
   m.Bind(&expected_fail);
   m.AdvanceCurrentPosition(3);  // Skip "xYz"
-  m.CheckNotBackReferenceIgnoreCase(2, false, false, &succ);
+  m.CheckNotBackReferenceIgnoreCase(2, false, &succ);
   m.Fail();
 
   m.Bind(&succ);
@@ -1094,7 +1093,7 @@ TEST(MacroAssemblerNativeRegisters) {
   m.AdvanceCurrentPosition(2);
   m.PopCurrentPosition();
 
-  m.Bind(&backtrack);
+  m.BindJumpTarget(&backtrack);
   m.PopRegister(out1);
   m.ReadCurrentPositionFromRegister(out1);
   m.AdvanceCurrentPosition(3);
@@ -1131,7 +1130,7 @@ TEST(MacroAssemblerNativeRegisters) {
 
   m.Succeed();
 
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.Fail();
 
   Handle<String> source = factory->NewStringFromStaticChars("<loop test>");
@@ -1265,10 +1264,10 @@ TEST(MacroAssembler) {
   m.AdvanceCurrentPosition(3);
   m.PushBacktrack(&backtrack);
   m.Succeed();
-  m.Bind(&backtrack);
+  m.BindJumpTarget(&backtrack);
   m.ClearRegisters(2, 3);
   m.Backtrack();
-  m.Bind(&fail);
+  m.BindJumpTarget(&fail);
   m.PopRegister(0);
   m.Fail();
 
diff --git a/deps/v8/test/cctest/test-roots.cc b/deps/v8/test/cctest/test-roots.cc
index f3d1a56543..26002621b6 100644
--- a/deps/v8/test/cctest/test-roots.cc
+++ b/deps/v8/test/cctest/test-roots.cc
@@ -44,7 +44,6 @@ bool IsInitiallyMutable(Factory* factory, Address object_address) {
   V(builtins_constants_table)             \
   V(current_microtask)                    \
   V(detached_contexts)                    \
-  V(dirty_js_finalization_groups)         \
   V(feedback_vectors_for_profiling_tools) \
   V(shared_wasm_memories)                 \
   V(materialized_objects)                 \
diff --git a/deps/v8/test/cctest/test-sampler-api.cc b/deps/v8/test/cctest/test-sampler-api.cc
index 3c8f352551..7197101d41 100644
--- a/deps/v8/test/cctest/test-sampler-api.cc
+++ b/deps/v8/test/cctest/test-sampler-api.cc
@@ -7,7 +7,6 @@
 #include <map>
 #include <string>
 #include "include/v8.h"
-#include "src/execution/simulator.h"
 #include "src/flags/flags.h"
 #include "test/cctest/cctest.h"
 
@@ -31,68 +30,6 @@ class Sample {
 };
 
 
-#if defined(USE_SIMULATOR)
-class SimulatorHelper {
- public:
-  inline bool Init(v8::Isolate* isolate) {
-    simulator_ = reinterpret_cast<v8::internal::Isolate*>(isolate)
-                     ->thread_local_top()
-                     ->simulator_;
-    // Check if there is active simulator.
-    return simulator_ != nullptr;
-  }
-
-  inline void FillRegisters(v8::RegisterState* state) {
-#if V8_TARGET_ARCH_ARM
-    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
-    state->sp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::sp));
-    state->fp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::r11));
-    state->lr = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::lr));
-#elif V8_TARGET_ARCH_ARM64
-    if (simulator_->sp() == 0 || simulator_->fp() == 0) {
-      // It's possible that the simulator is interrupted while it is updating
-      // the sp or fp register. ARM64 simulator does this in two steps:
-      // first setting it to zero and then setting it to a new value.
-      // Bailout if sp/fp doesn't contain the new value.
-      return;
-    }
-    state->pc = reinterpret_cast<void*>(simulator_->pc());
-    state->sp = reinterpret_cast<void*>(simulator_->sp());
-    state->fp = reinterpret_cast<void*>(simulator_->fp());
-    state->lr = reinterpret_cast<void*>(simulator_->lr());
-#elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
-    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
-    state->sp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::sp));
-    state->fp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::fp));
-#elif V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64
-    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
-    state->sp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::sp));
-    state->fp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::fp));
-    state->lr = reinterpret_cast<void*>(simulator_->get_lr());
-#elif V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
-    state->pc = reinterpret_cast<void*>(simulator_->get_pc());
-    state->sp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::sp));
-    state->fp = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::fp));
-    state->lr = reinterpret_cast<void*>(
-        simulator_->get_register(v8::internal::Simulator::ra));
-#endif
-  }
-
- private:
-  v8::internal::Simulator* simulator_;
-};
-#endif  // USE_SIMULATOR
-
-
 class SamplingTestHelper {
  public:
   struct CodeEventEntry {
diff --git a/deps/v8/test/cctest/test-serialize.cc b/deps/v8/test/cctest/test-serialize.cc
index f37b623504..7ce8ef7152 100644
--- a/deps/v8/test/cctest/test-serialize.cc
+++ b/deps/v8/test/cctest/test-serialize.cc
@@ -53,6 +53,7 @@
 #include "src/snapshot/partial-serializer.h"
 #include "src/snapshot/read-only-deserializer.h"
 #include "src/snapshot/read-only-serializer.h"
+#include "src/snapshot/snapshot-compression.h"
 #include "src/snapshot/snapshot.h"
 #include "src/snapshot/startup-deserializer.h"
 #include "src/snapshot/startup-serializer.h"
@@ -414,6 +415,24 @@ static void PartiallySerializeContext(Vector<const byte>* startup_blob_out,
   ReadOnlyHeap::ClearSharedHeapForTest();
 }
 
+UNINITIALIZED_TEST(SnapshotCompression) {
+  DisableAlwaysOpt();
+  Vector<const byte> startup_blob;
+  Vector<const byte> read_only_blob;
+  Vector<const byte> partial_blob;
+  PartiallySerializeContext(&startup_blob, &read_only_blob, &partial_blob);
+  SnapshotData original_snapshot_data(partial_blob);
+  SnapshotData compressed =
+      i::SnapshotCompression::Compress(&original_snapshot_data);
+  SnapshotData decompressed =
+      i::SnapshotCompression::Decompress(compressed.RawData());
+  CHECK_EQ(partial_blob, decompressed.RawData());
+
+  startup_blob.Dispose();
+  read_only_blob.Dispose();
+  partial_blob.Dispose();
+}
+
 UNINITIALIZED_TEST(PartialSerializerContext) {
   DisableAlwaysOpt();
   Vector<const byte> startup_blob;
@@ -888,7 +907,8 @@ void TestInt32Expectations(const Int32Expectations& expectations) {
 void TypedArrayTestHelper(
     const char* code, const Int32Expectations& expectations,
     const char* code_to_run_after_restore = nullptr,
-    const Int32Expectations& after_restore_expectations = Int32Expectations()) {
+    const Int32Expectations& after_restore_expectations = Int32Expectations(),
+    v8::ArrayBuffer::Allocator* allocator = nullptr) {
   DisableAlwaysOpt();
   i::FLAG_allow_natives_syntax = true;
   DisableEmbeddedBlobRefcounting();
@@ -914,7 +934,8 @@ void TypedArrayTestHelper(
   ReadOnlyHeap::ClearSharedHeapForTest();
   v8::Isolate::CreateParams create_params;
   create_params.snapshot_blob = &blob;
-  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
+  create_params.array_buffer_allocator =
+      allocator != nullptr ? allocator : CcTest::array_buffer_allocator();
   v8::Isolate* isolate = TestSerializer::NewIsolate(create_params);
   {
     v8::Isolate::Scope i_scope(isolate);
@@ -1010,6 +1031,46 @@ UNINITIALIZED_TEST(CustomSnapshotDataBlobDataView) {
   TypedArrayTestHelper(code, expectations);
 }
 
+namespace {
+class AlternatingArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
+ public:
+  AlternatingArrayBufferAllocator()
+      : allocation_fails_(false),
+        allocator_(v8::ArrayBuffer::Allocator::NewDefaultAllocator()) {}
+  ~AlternatingArrayBufferAllocator() { delete allocator_; }
+  void* Allocate(size_t length) override {
+    allocation_fails_ = !allocation_fails_;
+    if (allocation_fails_) return nullptr;
+    return allocator_->Allocate(length);
+  }
+
+  void* AllocateUninitialized(size_t length) override {
+    return this->Allocate(length);
+  }
+
+  void Free(void* data, size_t size) override { allocator_->Free(data, size); }
+
+  void* Reallocate(void* data, size_t old_length, size_t new_length) override {
+    return allocator_->Reallocate(data, old_length, new_length);
+  }
+
+ private:
+  bool allocation_fails_;
+  v8::ArrayBuffer::Allocator* allocator_;
+};
+}  // anonymous namespace
+
+UNINITIALIZED_TEST(CustomSnapshotManyArrayBuffers) {
+  const char* code =
+      "var buffers = [];"
+      "for (let i = 0; i < 70; i++) buffers.push(new Uint8Array(1000));";
+  Int32Expectations expectations = {std::make_tuple("buffers.length", 70)};
+  std::unique_ptr<v8::ArrayBuffer::Allocator> allocator(
+      new AlternatingArrayBufferAllocator());
+  TypedArrayTestHelper(code, expectations, nullptr, Int32Expectations(),
+                       allocator.get());
+}
+
 UNINITIALIZED_TEST(CustomSnapshotDataBlobDetachedArrayBuffer) {
   const char* code =
       "var x = new Int16Array([12, 24, 48]);"
@@ -1611,7 +1672,7 @@ void TestCodeSerializerOnePlusOneImpl(bool verify_builtins_count = true) {
 TEST(CodeSerializerOnePlusOne) { TestCodeSerializerOnePlusOneImpl(); }
 
 // See bug v8:9122
-#ifndef V8_TARGET_ARCH_ARM
+#if !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_S390X)
 TEST(CodeSerializerOnePlusOneWithInterpretedFramesNativeStack) {
   FLAG_interpreted_frames_native_stack = true;
   // We pass false because this test will create IET copies (which are
@@ -1810,7 +1871,7 @@ TEST(CodeSerializerLargeCodeObjectWithIncrementalMarking) {
   Handle<String> moving_object;
   Page* ec_page;
   {
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(heap);
     heap::SimulateFullSpace(heap->old_space());
     moving_object = isolate->factory()->InternalizeString(
         isolate->factory()->NewStringFromAsciiChecked("happy_hippo"));
@@ -2455,8 +2516,10 @@ TEST(CodeSerializerBitFlip) {
   const char* source = "function f() { return 'abc'; }; f() + 'def'";
   v8::ScriptCompiler::CachedData* cache = CompileRunAndProduceCache(source);
 
-  // Random bit flip.
-  const_cast<uint8_t*>(cache->data)[337] ^= 0x40;
+  // Arbitrary bit flip.
+  int arbitrary_spot = 337;
+  CHECK_LT(arbitrary_spot, cache->length);
+  const_cast<uint8_t*>(cache->data)[arbitrary_spot] ^= 0x40;
 
   v8::Isolate::CreateParams create_params;
   create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
diff --git a/deps/v8/test/cctest/test-strings.cc b/deps/v8/test/cctest/test-strings.cc
index a3f3b89347..2a6843b892 100644
--- a/deps/v8/test/cctest/test-strings.cc
+++ b/deps/v8/test/cctest/test-strings.cc
@@ -686,7 +686,7 @@ void TestStringCharacterStream(BuildString build, int test_cases) {
   for (int i = 0; i < test_cases; i++) {
     printf("%d\n", i);
     HandleScope inner_scope(isolate);
-    AlwaysAllocateScope always_allocate(isolate);
+    AlwaysAllocateScopeForTesting always_allocate(isolate->heap());
     // Build flat version of cons string.
     Handle<String> flat_string = build(i, &data);
     ConsStringStats flat_string_stats;
@@ -1347,10 +1347,9 @@ TEST(CachedHashOverflow) {
     const char* line = lines[i];
     printf("%s\n", line);
     v8::Local<v8::Value> result =
-        v8::Script::Compile(context,
-                            v8::String::NewFromUtf8(CcTest::isolate(), line,
-                                                    v8::NewStringType::kNormal)
-                                .ToLocalChecked())
+        v8::Script::Compile(
+            context,
+            v8::String::NewFromUtf8(CcTest::isolate(), line).ToLocalChecked())
             .ToLocalChecked()
             ->Run(context)
             .ToLocalChecked();
@@ -1873,11 +1872,6 @@ void TestString(i::Isolate* isolate, const IndexData& data) {
     uint32_t index;
     CHECK(s->AsArrayIndex(&index));
     CHECK_EQ(data.array_index, index);
-    // AsArrayIndex only forces hash computation for cacheable indices;
-    // so trigger hash computation for longer strings manually.
-    if (s->length() > String::kMaxCachedArrayIndexLength) s->Hash();
-    CHECK_EQ(0, s->hash_field() & String::kIsNotArrayIndexMask);
-    CHECK(s->HasHashCode());
   }
   if (data.is_integer_index) {
     size_t index;
@@ -1889,9 +1883,6 @@ void TestString(i::Isolate* isolate, const IndexData& data) {
   }
   if (!s->HasHashCode()) s->Hash();
   CHECK(s->HasHashCode());
-  if (!data.is_array_index) {
-    CHECK_NE(0, s->hash_field() & String::kIsNotArrayIndexMask);
-  }
   if (!data.is_integer_index) {
     CHECK_NE(0, s->hash_field() & String::kIsNotIntegerIndexMask);
   }
@@ -1942,21 +1933,13 @@ TEST(StringEquals) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
 
-  auto foo_str =
-      v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
-          .ToLocalChecked();
-  auto bar_str =
-      v8::String::NewFromUtf8(isolate, "bar", v8::NewStringType::kNormal)
-          .ToLocalChecked();
-  auto foo_str2 =
-      v8::String::NewFromUtf8(isolate, "foo", v8::NewStringType::kNormal)
-          .ToLocalChecked();
+  auto foo_str = v8::String::NewFromUtf8Literal(isolate, "foo");
+  auto bar_str = v8::String::NewFromUtf8Literal(isolate, "bar");
+  auto foo_str2 = v8::String::NewFromUtf8Literal(isolate, "foo");
 
   uint16_t* two_byte_source = AsciiToTwoByteString("foo");
   auto foo_two_byte_str =
-      v8::String::NewFromTwoByte(isolate, two_byte_source,
-                                 v8::NewStringType::kNormal)
-          .ToLocalChecked();
+      v8::String::NewFromTwoByte(isolate, two_byte_source).ToLocalChecked();
   i::DeleteArray(two_byte_source);
 
   CHECK(foo_str->StringEquals(foo_str));
diff --git a/deps/v8/test/cctest/test-sync-primitives-arm64.cc b/deps/v8/test/cctest/test-sync-primitives-arm64.cc
index f5f19f0687..c6f0d2c2f5 100644
--- a/deps/v8/test/cctest/test-sync-primitives-arm64.cc
+++ b/deps/v8/test/cctest/test-sync-primitives-arm64.cc
@@ -200,7 +200,7 @@ void TestInvalidateExclusiveAccess(TestData initial_data, MemoryAccess access1,
   AssembleLoadExcl(&masm, access1, w1, x1);
   AssembleMemoryAccess(&masm, access2, w3, w2, x1);
   AssembleStoreExcl(&masm, access3, w0, w3, x1);
-  __ br(lr);
+  __ Ret();
 
   CodeDesc desc;
   masm.GetCode(isolate, &desc);
@@ -271,7 +271,7 @@ int ExecuteMemoryAccess(Isolate* isolate, TestData* test_data,
   HandleScope scope(isolate);
   MacroAssembler masm(isolate, v8::internal::CodeObjectRequired::kYes);
   AssembleMemoryAccess(&masm, access, w0, w2, x1);
-  __ br(lr);
+  __ Ret();
 
   CodeDesc desc;
   masm.GetCode(isolate, &desc);
diff --git a/deps/v8/test/cctest/test-thread-termination.cc b/deps/v8/test/cctest/test-thread-termination.cc
index f7cd09848e..b371cd8d3c 100644
--- a/deps/v8/test/cctest/test-thread-termination.cc
+++ b/deps/v8/test/cctest/test-thread-termination.cc
@@ -492,10 +492,11 @@ TEST(TerminateFromOtherThreadWhileMicrotaskRunning) {
   isolate->EnqueueMicrotask(
       v8::Function::New(isolate->GetCurrentContext(), MicrotaskShouldNotRun)
           .ToLocalChecked());
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
 
   isolate->CancelTerminateExecution();
-  isolate->RunMicrotasks();  // should not run MicrotaskShouldNotRun
+  // Should not run MicrotaskShouldNotRun.
+  isolate->PerformMicrotaskCheckpoint();
 
   thread.Join();
   delete semaphore;
@@ -913,7 +914,7 @@ TEST(TerminateInMicrotask) {
       CHECK(context2 == isolate->GetCurrentContext());
       CHECK(context2 == isolate->GetEnteredOrMicrotaskContext());
       CHECK(!isolate->IsExecutionTerminating());
-      isolate->RunMicrotasks();
+      isolate->PerformMicrotaskCheckpoint();
       CHECK(context2 == isolate->GetCurrentContext());
       CHECK(context2 == isolate->GetEnteredOrMicrotaskContext());
       CHECK(try_catch.HasCaught());
@@ -948,7 +949,7 @@ TEST(TerminateInApiMicrotask) {
     CHECK(!isolate->IsExecutionTerminating());
     isolate->EnqueueMicrotask(TerminationMicrotask);
     isolate->EnqueueMicrotask(UnreachableMicrotask);
-    isolate->RunMicrotasks();
+    isolate->PerformMicrotaskCheckpoint();
     CHECK(try_catch.HasCaught());
     CHECK(try_catch.HasTerminated());
     CHECK(isolate->IsExecutionTerminating());
diff --git a/deps/v8/test/cctest/test-types.cc b/deps/v8/test/cctest/test-types.cc
index fc213b5bf9..0b05dff6b8 100644
--- a/deps/v8/test/cctest/test-types.cc
+++ b/deps/v8/test/cctest/test-types.cc
@@ -180,20 +180,22 @@ struct Tests {
     // Constructor
     for (ValueIterator vt = T.values.begin(); vt != T.values.end(); ++vt) {
       Handle<i::Object> value = *vt;
-      Type type = T.NewConstant(value);
-      CHECK(type.IsHeapConstant() || type.IsOtherNumberConstant() ||
-            type.IsRange());
+      Type type = T.Constant(value);
+      CHECK(type.IsBitset() || type.IsHeapConstant() ||
+            type.IsOtherNumberConstant() || type.IsRange());
     }
 
     // Value attribute
     for (ValueIterator vt = T.values.begin(); vt != T.values.end(); ++vt) {
       Handle<i::Object> value = *vt;
-      Type type = T.NewConstant(value);
+      Type type = T.Constant(value);
       if (type.IsHeapConstant()) {
         CHECK(value.address() == type.AsHeapConstant()->Value().address());
       } else if (type.IsOtherNumberConstant()) {
         CHECK(value->IsHeapNumber());
         CHECK(value->Number() == type.AsOtherNumberConstant()->Value());
+      } else if (type.IsBitset()) {
+        CHECK(type.IsSingleton());
       } else {
         CHECK(type.IsRange());
         double v = value->Number();
@@ -206,8 +208,8 @@ struct Tests {
       for (ValueIterator vt2 = T.values.begin(); vt2 != T.values.end(); ++vt2) {
         Handle<i::Object> value1 = *vt1;
         Handle<i::Object> value2 = *vt2;
-        Type type1 = T.NewConstant(value1);
-        Type type2 = T.NewConstant(value2);
+        Type type1 = T.Constant(value1);
+        Type type2 = T.Constant(value2);
         if (type1.IsOtherNumberConstant() && type2.IsOtherNumberConstant()) {
           CHECK(Equal(type1, type2) ==
                 (type1.AsOtherNumberConstant()->Value() ==
@@ -224,62 +226,70 @@ struct Tests {
 
     // Typing of numbers
     Factory* fac = isolate->factory();
-    CHECK(T.NewConstant(fac->NewNumber(0)).Is(T.UnsignedSmall));
-    CHECK(T.NewConstant(fac->NewNumber(1)).Is(T.UnsignedSmall));
-    CHECK(T.NewConstant(fac->NewNumber(0x3FFFFFFF)).Is(T.UnsignedSmall));
-    CHECK(T.NewConstant(fac->NewNumber(-1)).Is(T.Negative31));
-    CHECK(T.NewConstant(fac->NewNumber(-0x3FFFFFFF)).Is(T.Negative31));
-    CHECK(T.NewConstant(fac->NewNumber(-0x40000000)).Is(T.Negative31));
-    CHECK(T.NewConstant(fac->NewNumber(0x40000000)).Is(T.Unsigned31));
-    CHECK(!T.NewConstant(fac->NewNumber(0x40000000)).Is(T.Unsigned30));
-    CHECK(T.NewConstant(fac->NewNumber(0x7FFFFFFF)).Is(T.Unsigned31));
-    CHECK(!T.NewConstant(fac->NewNumber(0x7FFFFFFF)).Is(T.Unsigned30));
-    CHECK(T.NewConstant(fac->NewNumber(-0x40000001)).Is(T.Negative32));
-    CHECK(!T.NewConstant(fac->NewNumber(-0x40000001)).Is(T.Negative31));
-    CHECK(T.NewConstant(fac->NewNumber(-0x7FFFFFFF)).Is(T.Negative32));
-    CHECK(!T.NewConstant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.Negative31));
+    CHECK(T.Constant(fac->NewNumber(0)).Is(T.UnsignedSmall));
+    CHECK(T.Constant(fac->NewNumber(1)).Is(T.UnsignedSmall));
+    CHECK(T.Constant(fac->NewNumber(42)).Equals(T.Range(42, 42)));
+    CHECK(T.Constant(fac->NewNumber(0x3FFFFFFF)).Is(T.UnsignedSmall));
+    CHECK(T.Constant(fac->NewNumber(-1)).Is(T.Negative31));
+    CHECK(T.Constant(fac->NewNumber(-0x3FFFFFFF)).Is(T.Negative31));
+    CHECK(T.Constant(fac->NewNumber(-0x40000000)).Is(T.Negative31));
+    CHECK(T.Constant(fac->NewNumber(0x40000000)).Is(T.Unsigned31));
+    CHECK(!T.Constant(fac->NewNumber(0x40000000)).Is(T.Unsigned30));
+    CHECK(T.Constant(fac->NewNumber(0x7FFFFFFF)).Is(T.Unsigned31));
+    CHECK(!T.Constant(fac->NewNumber(0x7FFFFFFF)).Is(T.Unsigned30));
+    CHECK(T.Constant(fac->NewNumber(-0x40000001)).Is(T.Negative32));
+    CHECK(!T.Constant(fac->NewNumber(-0x40000001)).Is(T.Negative31));
+    CHECK(T.Constant(fac->NewNumber(-0x7FFFFFFF)).Is(T.Negative32));
+    CHECK(!T.Constant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.Negative31));
     if (SmiValuesAre31Bits()) {
-      CHECK(!T.NewConstant(fac->NewNumber(0x40000000)).Is(T.UnsignedSmall));
-      CHECK(!T.NewConstant(fac->NewNumber(0x7FFFFFFF)).Is(T.UnsignedSmall));
-      CHECK(!T.NewConstant(fac->NewNumber(-0x40000001)).Is(T.SignedSmall));
-      CHECK(!T.NewConstant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.SignedSmall));
+      CHECK(!T.Constant(fac->NewNumber(0x40000000)).Is(T.UnsignedSmall));
+      CHECK(!T.Constant(fac->NewNumber(0x7FFFFFFF)).Is(T.UnsignedSmall));
+      CHECK(!T.Constant(fac->NewNumber(-0x40000001)).Is(T.SignedSmall));
+      CHECK(!T.Constant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.SignedSmall));
     } else {
       CHECK(SmiValuesAre32Bits());
-      CHECK(T.NewConstant(fac->NewNumber(0x40000000)).Is(T.UnsignedSmall));
-      CHECK(T.NewConstant(fac->NewNumber(0x7FFFFFFF)).Is(T.UnsignedSmall));
-      CHECK(T.NewConstant(fac->NewNumber(-0x40000001)).Is(T.SignedSmall));
-      CHECK(T.NewConstant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.SignedSmall));
-    }
-    CHECK(T.NewConstant(fac->NewNumber(0x80000000u)).Is(T.Unsigned32));
-    CHECK(!T.NewConstant(fac->NewNumber(0x80000000u)).Is(T.Unsigned31));
-    CHECK(T.NewConstant(fac->NewNumber(0xFFFFFFFFu)).Is(T.Unsigned32));
-    CHECK(!T.NewConstant(fac->NewNumber(0xFFFFFFFFu)).Is(T.Unsigned31));
-    CHECK(T.NewConstant(fac->NewNumber(0xFFFFFFFFu + 1.0)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(0xFFFFFFFFu + 1.0)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(-0x7FFFFFFF - 2.0)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(-0x7FFFFFFF - 2.0)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(0.1)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(0.1)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(-10.1)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(-10.1)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(10e60)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(10e60)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(-1.0 * 0.0)).Is(T.MinusZero));
-    CHECK(
-        T.NewConstant(fac->NewNumber(std::numeric_limits<double>::quiet_NaN()))
-            .Is(T.NaN));
-    CHECK(T.NewConstant(fac->NewNumber(V8_INFINITY)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(V8_INFINITY)).Is(T.Integral32));
-    CHECK(T.NewConstant(fac->NewNumber(-V8_INFINITY)).Is(T.PlainNumber));
-    CHECK(!T.NewConstant(fac->NewNumber(-V8_INFINITY)).Is(T.Integral32));
+      CHECK(T.Constant(fac->NewNumber(0x40000000)).Is(T.UnsignedSmall));
+      CHECK(T.Constant(fac->NewNumber(0x7FFFFFFF)).Is(T.UnsignedSmall));
+      CHECK(T.Constant(fac->NewNumber(-0x40000001)).Is(T.SignedSmall));
+      CHECK(T.Constant(fac->NewNumber(-0x7FFFFFFF - 1)).Is(T.SignedSmall));
+    }
+    CHECK(T.Constant(fac->NewNumber(0x80000000u)).Is(T.Unsigned32));
+    CHECK(!T.Constant(fac->NewNumber(0x80000000u)).Is(T.Unsigned31));
+    CHECK(T.Constant(fac->NewNumber(0xFFFFFFFFu)).Is(T.Unsigned32));
+    CHECK(!T.Constant(fac->NewNumber(0xFFFFFFFFu)).Is(T.Unsigned31));
+    CHECK(T.Constant(fac->NewNumber(0xFFFFFFFFu + 1.0)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(0xFFFFFFFFu + 1.0)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(-0x7FFFFFFF - 2.0)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(-0x7FFFFFFF - 2.0)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(0.1)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(0.1)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(-10.1)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(-10.1)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(10e60)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(10e60)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(-1.0 * 0.0)).Is(T.MinusZero));
+    CHECK(T.Constant(fac->NewNumber(V8_INFINITY)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(V8_INFINITY)).Is(T.Integral32));
+    CHECK(T.Constant(fac->NewNumber(-V8_INFINITY)).Is(T.PlainNumber));
+    CHECK(!T.Constant(fac->NewNumber(-V8_INFINITY)).Is(T.Integral32));
 
     // Typing of Strings
     Handle<String> s1 = fac->NewStringFromAsciiChecked("a");
-    CHECK(T.NewConstant(s1).Is(T.InternalizedString));
+    CHECK(T.Constant(s1).Is(T.InternalizedString));
     const uc16 two_byte[1] = {0x2603};
     Handle<String> s2 =
         fac->NewTwoByteInternalizedString(Vector<const uc16>(two_byte, 1), 1);
-    CHECK(T.NewConstant(s2).Is(T.InternalizedString));
+    CHECK(T.Constant(s2).Is(T.InternalizedString));
+
+    // Typing of special constants
+    CHECK(T.Constant(fac->the_hole_value()).Equals(T.Hole));
+    CHECK(T.Constant(fac->null_value()).Equals(T.Null));
+    CHECK(T.Constant(fac->undefined_value()).Equals(T.Undefined));
+    CHECK(T.Constant(fac->minus_zero_value()).Equals(T.MinusZero));
+    CHECK(T.Constant(fac->NewNumber(-0.0)).Equals(T.MinusZero));
+    CHECK(T.Constant(fac->nan_value()).Equals(T.NaN));
+    CHECK(T.Constant(fac->NewNumber(std::numeric_limits<double>::quiet_NaN()))
+              .Equals(T.NaN));
   }
 
   void Range() {
@@ -545,8 +555,8 @@ struct Tests {
       for (ValueIterator vt2 = T.values.begin(); vt2 != T.values.end(); ++vt2) {
         Handle<i::Object> value1 = *vt1;
         Handle<i::Object> value2 = *vt2;
-        Type const_type1 = T.NewConstant(value1);
-        Type const_type2 = T.NewConstant(value2);
+        Type const_type1 = T.Constant(value1);
+        Type const_type2 = T.Constant(value2);
         if (const_type1.IsOtherNumberConstant() &&
             const_type2.IsOtherNumberConstant()) {
           CHECK(const_type1.Is(const_type2) ==
@@ -686,8 +696,8 @@ struct Tests {
       for (ValueIterator vt2 = T.values.begin(); vt2 != T.values.end(); ++vt2) {
         Handle<i::Object> value1 = *vt1;
         Handle<i::Object> value2 = *vt2;
-        Type const_type1 = T.NewConstant(value1);
-        Type const_type2 = T.NewConstant(value2);
+        Type const_type1 = T.Constant(value1);
+        Type const_type2 = T.Constant(value2);
         if (const_type1.IsOtherNumberConstant() &&
             const_type2.IsOtherNumberConstant()) {
           CHECK(const_type1.Maybe(const_type2) ==
@@ -1045,37 +1055,21 @@ struct Tests {
 }  // namespace
 
 TEST(IsSomeType) { Tests().IsSomeType(); }
-
 TEST(BitsetType) { Tests().Bitset(); }
-
 TEST(ConstantType) { Tests().Constant(); }
-
 TEST(RangeType) { Tests().Range(); }
-
 TEST(MinMax) { Tests().MinMax(); }
-
 TEST(BitsetGlb) { Tests().BitsetGlb(); }
-
 TEST(BitsetLub) { Tests().BitsetLub(); }
-
 TEST(Is1) { Tests().Is1(); }
-
 TEST(Is2) { Tests().Is2(); }
-
 TEST(Maybe) { Tests().Maybe(); }
-
 TEST(Union1) { Tests().Union1(); }
-
 TEST(Union2) { Tests().Union2(); }
-
 TEST(Union3) { Tests().Union3(); }
-
 TEST(Union4) { Tests().Union4(); }
-
 TEST(Intersect) { Tests().Intersect(); }
-
 TEST(Distributivity) { Tests().Distributivity(); }
-
 TEST(GetRange) { Tests().GetRange(); }
 
 }  // namespace compiler
diff --git a/deps/v8/test/cctest/test-unwinder-code-pages.cc b/deps/v8/test/cctest/test-unwinder-code-pages.cc
index 6177be6de8..fc023e4145 100644
--- a/deps/v8/test/cctest/test-unwinder-code-pages.cc
+++ b/deps/v8/test/cctest/test-unwinder-code-pages.cc
@@ -591,6 +591,80 @@ TEST(PCIsInV8_LargeCodeObject_CodePagesAPI) {
   CHECK(v8::Unwinder::PCIsInV8(pages_length, code_pages, pc));
 }
 
+#ifdef USE_SIMULATOR
+// TODO(v8:10026): Make this also work without the simulator. The part that
+// needs modifications is getting the RegisterState.
+class UnwinderTestHelper {
+ public:
+  explicit UnwinderTestHelper(const std::string& test_function)
+      : isolate_(CcTest::isolate()) {
+    CHECK(!instance_);
+    instance_ = this;
+    v8::HandleScope scope(isolate_);
+    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate_);
+    global->Set(v8_str("TryUnwind"),
+                v8::FunctionTemplate::New(isolate_, TryUnwind));
+    LocalContext env(isolate_, nullptr, global);
+    CompileRun(v8_str(test_function.c_str()));
+  }
+
+  ~UnwinderTestHelper() { instance_ = nullptr; }
+
+ private:
+  static void TryUnwind(const v8::FunctionCallbackInfo<v8::Value>& args) {
+    instance_->DoTryUnwind();
+  }
+
+  void DoTryUnwind() {
+    // Set up RegisterState.
+    v8::RegisterState register_state;
+    SimulatorHelper simulator_helper;
+    if (!simulator_helper.Init(isolate_)) return;
+    simulator_helper.FillRegisters(&register_state);
+    // At this point, the PC will point to a Redirection object, which is not
+    // in V8 as far as the unwinder is concerned. To make this work, point to
+    // the return address, which is in V8, instead.
+    register_state.pc = register_state.lr;
+
+    JSEntryStubs entry_stubs = isolate_->GetJSEntryStubs();
+    MemoryRange code_pages[v8::Isolate::kMinCodePagesBufferSize];
+    size_t pages_length =
+        isolate_->CopyCodePages(arraysize(code_pages), code_pages);
+    CHECK_LE(pages_length, arraysize(code_pages));
+
+    void* stack_base = reinterpret_cast<void*>(0xffffffffffffffffL);
+    bool unwound = v8::Unwinder::TryUnwindV8Frames(
+        entry_stubs, pages_length, code_pages, &register_state, stack_base);
+    // Check that we have successfully unwound past js_entry_sp.
+    CHECK(unwound);
+    CHECK_GT(register_state.sp,
+             reinterpret_cast<void*>(CcTest::i_isolate()->js_entry_sp()));
+  }
+
+  v8::Isolate* isolate_;
+
+  static UnwinderTestHelper* instance_;
+};
+
+UnwinderTestHelper* UnwinderTestHelper::instance_;
+
+TEST(Unwind_TwoNestedFunctions_CodePagesAPI) {
+  i::FLAG_allow_natives_syntax = true;
+  const char* test_script =
+      "function test_unwinder_api_inner() {"
+      "  TryUnwind();"
+      "  return 0;"
+      "}"
+      "function test_unwinder_api_outer() {"
+      "  return test_unwinder_api_inner();"
+      "}"
+      "%NeverOptimizeFunction(test_unwinder_api_inner);"
+      "%NeverOptimizeFunction(test_unwinder_api_outer);"
+      "test_unwinder_api_outer();";
+
+  UnwinderTestHelper helper(test_script);
+}
+#endif
 }  // namespace test_unwinder_code_pages
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/test-unwinder.cc b/deps/v8/test/cctest/test-unwinder.cc
index ffe46f4ca2..59c8708767 100644
--- a/deps/v8/test/cctest/test-unwinder.cc
+++ b/deps/v8/test/cctest/test-unwinder.cc
@@ -7,6 +7,7 @@
 #include "src/api/api-inl.h"
 #include "src/builtins/builtins.h"
 #include "src/execution/isolate.h"
+#include "src/execution/pointer-authentication.h"
 #include "src/heap/spaces.h"
 #include "src/objects/code-inl.h"
 #include "test/cctest/cctest.h"
@@ -38,6 +39,11 @@ TEST(Unwind_BadState_Fail) {
   CHECK_NULL(register_state.pc);
 }
 
+void StorePc(uintptr_t stack[], int index, uintptr_t pc) {
+  Address sp = reinterpret_cast<Address>(&stack[index]) + kSystemPointerSize;
+  stack[index] = PointerAuthentication::SignPCWithSP(pc, sp);
+}
+
 TEST(Unwind_BuiltinPCInMiddle_Success) {
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -49,7 +55,7 @@ TEST(Unwind_BuiltinPCInMiddle_Success) {
   uintptr_t stack[3];
   void* stack_base = stack + arraysize(stack);
   stack[0] = reinterpret_cast<uintptr_t>(stack + 2);  // saved FP (rbp).
-  stack[1] = 202;  // Return address into C++ code.
+  StorePc(stack, 1, 202);  // Return address into C++ code.
   stack[2] = 303;  // The SP points here in the caller's frame.
 
   register_state.sp = stack;
@@ -93,9 +99,9 @@ TEST(Unwind_BuiltinPCAtStart_Success) {
   stack[0] = 101;
   // Return address into JS code. It doesn't matter that this is not actually in
   // JSEntry, because we only check that for the top frame.
-  stack[1] = reinterpret_cast<uintptr_t>(code + 10);
+  StorePc(stack, 1, reinterpret_cast<uintptr_t>(code + 10));
   stack[2] = reinterpret_cast<uintptr_t>(stack + 5);  // saved FP (rbp).
-  stack[3] = 303;  // Return address into C++ code.
+  StorePc(stack, 3, 303);  // Return address into C++ code.
   stack[4] = 404;
   stack[5] = 505;
 
@@ -145,7 +151,7 @@ TEST(Unwind_CodeObjectPCInMiddle_Success) {
   uintptr_t stack[3];
   void* stack_base = stack + arraysize(stack);
   stack[0] = reinterpret_cast<uintptr_t>(stack + 2);  // saved FP (rbp).
-  stack[1] = 202;  // Return address into C++ code.
+  StorePc(stack, 1, 202);  // Return address into C++ code.
   stack[2] = 303;  // The SP points here in the caller's frame.
 
   register_state.sp = stack;
@@ -213,7 +219,7 @@ TEST(Unwind_JSEntryBeforeFrame_Fail) {
   stack[3] = 131;
   stack[4] = 141;
   stack[5] = 151;
-  stack[6] = 100;  // Return address into C++ code.
+  StorePc(stack, 6, 100);  // Return address into C++ code.
   stack[7] = 303;  // The SP points here in the caller's frame.
   stack[8] = 404;
   stack[9] = 505;
@@ -267,7 +273,7 @@ TEST(Unwind_OneJSFrame_Success) {
   stack[3] = 131;
   stack[4] = 141;
   stack[5] = reinterpret_cast<uintptr_t>(stack + 9);  // saved FP (rbp).
-  stack[6] = 100;  // Return address into C++ code.
+  StorePc(stack, 6, 100);  // Return address into C++ code.
   stack[7] = 303;  // The SP points here in the caller's frame.
   stack[8] = 404;
   stack[9] = 505;
@@ -311,10 +317,10 @@ TEST(Unwind_TwoJSFrames_Success) {
   stack[1] = 111;
   stack[2] = reinterpret_cast<uintptr_t>(stack + 5);  // saved FP (rbp).
   // The fake return address is in the JS code range.
-  stack[3] = reinterpret_cast<uintptr_t>(code + 10);
+  StorePc(stack, 3, reinterpret_cast<uintptr_t>(code + 10));
   stack[4] = 141;
   stack[5] = reinterpret_cast<uintptr_t>(stack + 9);  // saved FP (rbp).
-  stack[6] = 100;  // Return address into C++ code.
+  StorePc(stack, 6, 100);  // Return address into C++ code.
   stack[7] = 303;  // The SP points here in the caller's frame.
   stack[8] = 404;
   stack[9] = 505;
@@ -371,7 +377,7 @@ TEST(Unwind_StackBounds_Basic) {
 
   uintptr_t stack[3];
   stack[0] = reinterpret_cast<uintptr_t>(stack + 2);  // saved FP (rbp).
-  stack[1] = 202;  // Return address into C++ code.
+  StorePc(stack, 1, 202);  // Return address into C++ code.
   stack[2] = 303;  // The SP points here in the caller's frame.
 
   register_state.sp = stack;
@@ -414,12 +420,12 @@ TEST(Unwind_StackBounds_WithUnwinding) {
   stack[3] = 131;
   stack[4] = 141;
   stack[5] = reinterpret_cast<uintptr_t>(stack + 9);  // saved FP (rbp).
-  stack[6] = reinterpret_cast<uintptr_t>(code + 20);  // JS code.
+  StorePc(stack, 6, reinterpret_cast<uintptr_t>(code + 20));  // JS code.
   stack[7] = 303;  // The SP points here in the caller's frame.
   stack[8] = 404;
   stack[9] = reinterpret_cast<uintptr_t>(stack) +
              (12 * sizeof(uintptr_t));                 // saved FP (OOB).
-  stack[10] = reinterpret_cast<uintptr_t>(code + 20);  // JS code.
+  StorePc(stack, 10, reinterpret_cast<uintptr_t>(code + 20));  // JS code.
 
   register_state.sp = stack;
   register_state.fp = stack + 5;
@@ -435,7 +441,7 @@ TEST(Unwind_StackBounds_WithUnwinding) {
   // Change the return address so that it is not in range. We will not range
   // check the stack[9] FP value because we have finished unwinding and the
   // contents of rbp does not necessarily have to be the FP in this case.
-  stack[10] = 202;
+  StorePc(stack, 10, 202);
   unwound = v8::Unwinder::TryUnwindV8Frames(unwind_state, &register_state,
                                             stack_base);
   CHECK(unwound);
@@ -549,6 +555,76 @@ TEST(PCIsInV8_LargeCodeObject) {
   CHECK(v8::Unwinder::PCIsInV8(unwind_state, pc));
 }
 
+#ifdef USE_SIMULATOR
+// TODO(v8:10026): Make this also work without the simulator. The part that
+// needs modifications is getting the RegisterState.
+class UnwinderTestHelper {
+ public:
+  explicit UnwinderTestHelper(const std::string& test_function)
+      : isolate_(CcTest::isolate()) {
+    CHECK(!instance_);
+    instance_ = this;
+    v8::HandleScope scope(isolate_);
+    v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate_);
+    global->Set(v8_str("TryUnwind"),
+                v8::FunctionTemplate::New(isolate_, TryUnwind));
+    LocalContext env(isolate_, nullptr, global);
+    CompileRun(v8_str(test_function.c_str()));
+  }
+
+  ~UnwinderTestHelper() { instance_ = nullptr; }
+
+ private:
+  static void TryUnwind(const v8::FunctionCallbackInfo<v8::Value>& args) {
+    instance_->DoTryUnwind();
+  }
+
+  void DoTryUnwind() {
+    // Set up RegisterState.
+    v8::RegisterState register_state;
+    SimulatorHelper simulator_helper;
+    if (!simulator_helper.Init(isolate_)) return;
+    simulator_helper.FillRegisters(&register_state);
+    // At this point, the PC will point to a Redirection object, which is not
+    // in V8 as far as the unwinder is concerned. To make this work, point to
+    // the return address, which is in V8, instead.
+    register_state.pc = register_state.lr;
+
+    UnwindState unwind_state = isolate_->GetUnwindState();
+    void* stack_base = reinterpret_cast<void*>(0xffffffffffffffffL);
+    bool unwound = v8::Unwinder::TryUnwindV8Frames(unwind_state,
+                                                   &register_state, stack_base);
+    // Check that we have successfully unwound past js_entry_sp.
+    CHECK(unwound);
+    CHECK_GT(register_state.sp,
+             reinterpret_cast<void*>(CcTest::i_isolate()->js_entry_sp()));
+  }
+
+  v8::Isolate* isolate_;
+
+  static UnwinderTestHelper* instance_;
+};
+
+UnwinderTestHelper* UnwinderTestHelper::instance_;
+
+TEST(Unwind_TwoNestedFunctions) {
+  i::FLAG_allow_natives_syntax = true;
+  const char* test_script =
+      "function test_unwinder_api_inner() {"
+      "  TryUnwind();"
+      "  return 0;"
+      "}"
+      "function test_unwinder_api_outer() {"
+      "  return test_unwinder_api_inner();"
+      "}"
+      "%NeverOptimizeFunction(test_unwinder_api_inner);"
+      "%NeverOptimizeFunction(test_unwinder_api_outer);"
+      "test_unwinder_api_outer();";
+
+  UnwinderTestHelper helper(test_script);
+}
+#endif
+
 #if __clang__
 #pragma clang diagnostic pop
 #endif
diff --git a/deps/v8/test/cctest/test-usecounters.cc b/deps/v8/test/cctest/test-usecounters.cc
index 2c4d007c4b..589a90c245 100644
--- a/deps/v8/test/cctest/test-usecounters.cc
+++ b/deps/v8/test/cctest/test-usecounters.cc
@@ -115,6 +115,42 @@ TEST(RegExpMatchIsFalseishOnJSRegExp) {
   CHECK_EQ(1, use_counts[v8::Isolate::kRegExpMatchIsFalseishOnJSRegExp]);
 }
 
+TEST(ObjectPrototypeHasElements) {
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope scope(isolate);
+  LocalContext env;
+  int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
+  global_use_counts = use_counts;
+  CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
+
+  CompileRun("var o = {}; o[1] = 2;");
+  CHECK_EQ(0, use_counts[v8::Isolate::kObjectPrototypeHasElements]);
+
+  CompileRun("var o = {}; var p = {}; o.__proto__ = p; p[1] = 2;");
+  CHECK_EQ(0, use_counts[v8::Isolate::kObjectPrototypeHasElements]);
+
+  CompileRun("Object.prototype[1] = 2;");
+  CHECK_EQ(1, use_counts[v8::Isolate::kObjectPrototypeHasElements]);
+}
+
+TEST(ArrayPrototypeHasElements) {
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope scope(isolate);
+  LocalContext env;
+  int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
+  global_use_counts = use_counts;
+  CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
+
+  CompileRun("var a = []; a[1] = 2;");
+  CHECK_EQ(0, use_counts[v8::Isolate::kArrayPrototypeHasElements]);
+
+  CompileRun("var a = []; var p = []; a.__proto__ = p; p[1] = 2;");
+  CHECK_EQ(0, use_counts[v8::Isolate::kArrayPrototypeHasElements]);
+
+  CompileRun("Array.prototype[1] = 2;");
+  CHECK_EQ(1, use_counts[v8::Isolate::kArrayPrototypeHasElements]);
+}
+
 }  // namespace test_usecounters
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/test-v8windbg.cc b/deps/v8/test/cctest/test-v8windbg.cc
new file mode 100644
index 0000000000..57f259a377
--- /dev/null
+++ b/deps/v8/test/cctest/test-v8windbg.cc
@@ -0,0 +1,14 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/cctest/cctest.h"
+#include "tools/v8windbg/test/v8windbg-test.h"
+
+namespace v8 {
+namespace internal {
+
+UNINITIALIZED_TEST(V8windbg) { v8windbg_test::RunTests(); }
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/test/cctest/torque/test-torque.cc b/deps/v8/test/cctest/torque/test-torque.cc
index 4e94fe21f0..9442dab6f5 100644
--- a/deps/v8/test/cctest/torque/test-torque.cc
+++ b/deps/v8/test/cctest/torque/test-torque.cc
@@ -736,6 +736,35 @@ TEST(TestTestParentFrameArguments) {
   asm_tester.GenerateCode();
 }
 
+TEST(TestFullyGeneratedClassFromCpp) {
+  CcTest::InitializeVM();
+  Isolate* isolate(CcTest::i_isolate());
+  i::HandleScope scope(isolate);
+  CodeAssemblerTester asm_tester(isolate, 1);
+  TestTorqueAssembler m(asm_tester.state());
+  { m.Return(m.TestFullyGeneratedClassFromCpp()); }
+  FunctionTester ft(asm_tester.GenerateCode(), 0);
+  Handle<ExportedSubClass> result =
+      Handle<ExportedSubClass>::cast(ft.Call().ToHandleChecked());
+  CHECK_EQ(result->c_field(), 7);
+  CHECK_EQ(result->d_field(), 8);
+  CHECK_EQ(result->e_field(), 9);
+}
+
+TEST(TestFullyGeneratedClassWithElements) {
+  CcTest::InitializeVM();
+  Isolate* isolate(CcTest::i_isolate());
+  i::HandleScope scope(isolate);
+  CodeAssemblerTester asm_tester(isolate, 1);
+  TestTorqueAssembler m(asm_tester.state());
+  {
+    m.TestFullyGeneratedClassWithElements();
+    m.Return(m.UndefinedConstant());
+  }
+  FunctionTester ft(asm_tester.GenerateCode(), 0);
+  ft.Call();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/trace-extension.cc b/deps/v8/test/cctest/trace-extension.cc
index df24e83f39..9aa2f380f6 100644
--- a/deps/v8/test/cctest/trace-extension.cc
+++ b/deps/v8/test/cctest/trace-extension.cc
@@ -45,24 +45,16 @@ const char* TraceExtension::kSource =
 
 v8::Local<v8::FunctionTemplate> TraceExtension::GetNativeFunctionTemplate(
     v8::Isolate* isolate, v8::Local<v8::String> name) {
-  if (name->StrictEquals(
-          v8::String::NewFromUtf8(isolate, "trace", v8::NewStringType::kNormal)
-              .ToLocalChecked())) {
+  if (name->StrictEquals(v8::String::NewFromUtf8Literal(isolate, "trace"))) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::Trace);
   } else if (name->StrictEquals(
-                 v8::String::NewFromUtf8(isolate, "js_trace",
-                                         v8::NewStringType::kNormal)
-                     .ToLocalChecked())) {
+                 v8::String::NewFromUtf8Literal(isolate, "js_trace"))) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSTrace);
   } else if (name->StrictEquals(
-                 v8::String::NewFromUtf8(isolate, "js_entry_sp",
-                                         v8::NewStringType::kNormal)
-                     .ToLocalChecked())) {
+                 v8::String::NewFromUtf8Literal(isolate, "js_entry_sp"))) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSEntrySP);
-  } else if (name->StrictEquals(
-                 v8::String::NewFromUtf8(isolate, "js_entry_sp_level2",
-                                         v8::NewStringType::kNormal)
-                     .ToLocalChecked())) {
+  } else if (name->StrictEquals(v8::String::NewFromUtf8Literal(
+                 isolate, "js_entry_sp_level2"))) {
     return v8::FunctionTemplate::New(isolate, TraceExtension::JSEntrySPLevel2);
   }
   UNREACHABLE();
diff --git a/deps/v8/test/cctest/wasm/test-c-wasm-entry.cc b/deps/v8/test/cctest/wasm/test-c-wasm-entry.cc
index ab8545bf5d..2ac9151684 100644
--- a/deps/v8/test/cctest/wasm/test-c-wasm-entry.cc
+++ b/deps/v8/test/cctest/wasm/test-c-wasm-entry.cc
@@ -81,7 +81,7 @@ class CWasmEntryArgTester {
   WasmRunner<ReturnType, Args...> runner_;
   Isolate* isolate_;
   std::function<ReturnType(Args...)> expected_fn_;
-  FunctionSig* sig_;
+  const FunctionSig* sig_;
   Handle<Code> c_wasm_entry_;
   WasmCode* wasm_code_;
 };
diff --git a/deps/v8/test/cctest/wasm/test-compilation-cache.cc b/deps/v8/test/cctest/wasm/test-compilation-cache.cc
index 416b4e9df2..f4831fa8d1 100644
--- a/deps/v8/test/cctest/wasm/test-compilation-cache.cc
+++ b/deps/v8/test/cctest/wasm/test-compilation-cache.cc
@@ -5,6 +5,7 @@
 #include "src/api/api-inl.h"
 #include "src/init/v8.h"
 
+#include "src/wasm/streaming-decoder.h"
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-module-builder.h"
@@ -43,6 +44,35 @@ class TestResolver : public CompilationResultResolver {
   std::atomic<int>* pending_;
 };
 
+class StreamTester {
+ public:
+  explicit StreamTester(std::shared_ptr<TestResolver> test_resolver)
+      : internal_scope_(CcTest::i_isolate()), test_resolver_(test_resolver) {
+    i::Isolate* i_isolate = CcTest::i_isolate();
+
+    Handle<Context> context = i_isolate->native_context();
+
+    stream_ = i_isolate->wasm_engine()->StartStreamingCompilation(
+        i_isolate, WasmFeatures::All(), context,
+        "WebAssembly.compileStreaming()", test_resolver_);
+  }
+
+  void OnBytesReceived(const uint8_t* start, size_t length) {
+    stream_->OnBytesReceived(Vector<const uint8_t>(start, length));
+  }
+
+  void FinishStream() { stream_->Finish(); }
+
+  void SetCompiledModuleBytes(const uint8_t* start, size_t length) {
+    stream_->SetCompiledModuleBytes(Vector<const uint8_t>(start, length));
+  }
+
+ private:
+  i::HandleScope internal_scope_;
+  std::shared_ptr<StreamingDecoder> stream_;
+  std::shared_ptr<TestResolver> test_resolver_;
+};
+
 // Create a valid module such that the bytes depend on {n}.
 ZoneBuffer GetValidModuleBytes(Zone* zone, int n) {
   ZoneBuffer buffer(zone);
@@ -57,11 +87,51 @@ ZoneBuffer GetValidModuleBytes(Zone* zone, int n) {
   return buffer;
 }
 
+std::shared_ptr<NativeModule> SyncCompile(Vector<const uint8_t> bytes) {
+  ErrorThrower thrower(CcTest::i_isolate(), "Test");
+  auto enabled_features = WasmFeatures::FromIsolate(CcTest::i_isolate());
+  auto wire_bytes = ModuleWireBytes(bytes.begin(), bytes.end());
+  Handle<WasmModuleObject> module =
+      CcTest::i_isolate()
+          ->wasm_engine()
+          ->SyncCompile(CcTest::i_isolate(), enabled_features, &thrower,
+                        wire_bytes)
+          .ToHandleChecked();
+  return module->shared_native_module();
+}
+
+// Shared prefix.
+constexpr uint8_t kPrefix[] = {
+    WASM_MODULE_HEADER,                // module header
+    kTypeSectionCode,                  // section code
+    U32V_1(1 + SIZEOF_SIG_ENTRY_v_v),  // section size
+    U32V_1(1),                         // type count
+    SIG_ENTRY_v_v,                     // signature entry
+    kFunctionSectionCode,              // section code
+    U32V_1(2),                         // section size
+    U32V_1(1),                         // functions count
+    0,                                 // signature index
+    kCodeSectionCode,                  // section code
+    U32V_1(7),                         // section size
+    U32V_1(1),                         // functions count
+    5,                                 // body size
+};
+
+constexpr uint8_t kFunctionA[] = {
+    U32V_1(0), kExprI32Const, U32V_1(0), kExprDrop, kExprEnd,
+};
+constexpr uint8_t kFunctionB[] = {
+    U32V_1(0), kExprI32Const, U32V_1(1), kExprDrop, kExprEnd,
+};
+
+constexpr size_t kPrefixSize = arraysize(kPrefix);
+constexpr size_t kFunctionSize = arraysize(kFunctionA);
+
 }  // namespace
 
 TEST(TestAsyncCache) {
   CcTest::InitializeVM();
-  i::HandleScope internal_scope_(CcTest::i_isolate());
+  i::HandleScope internal_scope(CcTest::i_isolate());
   AccountingAllocator allocator;
   Zone zone(&allocator, "CompilationCacheTester");
 
@@ -95,6 +165,74 @@ TEST(TestAsyncCache) {
   CHECK_NE(resolverA1->native_module(), resolverB->native_module());
 }
 
+TEST(TestStreamingCache) {
+  CcTest::InitializeVM();
+
+  std::atomic<int> pending(3);
+  auto resolverA1 = std::make_shared<TestResolver>(&pending);
+  auto resolverA2 = std::make_shared<TestResolver>(&pending);
+  auto resolverB = std::make_shared<TestResolver>(&pending);
+
+  StreamTester testerA1(resolverA1);
+  StreamTester testerA2(resolverA2);
+  StreamTester testerB(resolverB);
+
+  // Start receiving kPrefix bytes.
+  testerA1.OnBytesReceived(kPrefix, kPrefixSize);
+  testerA2.OnBytesReceived(kPrefix, kPrefixSize);
+  testerB.OnBytesReceived(kPrefix, kPrefixSize);
+
+  // Receive function bytes and start streaming compilation.
+  testerA1.OnBytesReceived(kFunctionA, kFunctionSize);
+  testerA1.FinishStream();
+  testerA2.OnBytesReceived(kFunctionA, kFunctionSize);
+  testerA2.FinishStream();
+  testerB.OnBytesReceived(kFunctionB, kFunctionSize);
+  testerB.FinishStream();
+
+  while (pending > 0) {
+    v8::platform::PumpMessageLoop(i::V8::GetCurrentPlatform(),
+                                  CcTest::isolate());
+  }
+
+  std::shared_ptr<NativeModule> native_module_A1 = resolverA1->native_module();
+  std::shared_ptr<NativeModule> native_module_A2 = resolverA2->native_module();
+  std::shared_ptr<NativeModule> native_module_B = resolverB->native_module();
+  CHECK_EQ(native_module_A1, native_module_A2);
+  CHECK_NE(native_module_A1, native_module_B);
+}
+
+TEST(TestStreamingAndSyncCache) {
+  CcTest::InitializeVM();
+
+  std::atomic<int> pending(1);
+  auto resolver = std::make_shared<TestResolver>(&pending);
+  StreamTester tester(resolver);
+
+  tester.OnBytesReceived(kPrefix, kPrefixSize);
+
+  // Compile the same module synchronously to make sure we don't deadlock
+  // waiting for streaming compilation to finish.
+  auto full_bytes = OwnedVector<uint8_t>::New(kPrefixSize + kFunctionSize);
+  memcpy(full_bytes.begin(), kPrefix, kPrefixSize);
+  memcpy(full_bytes.begin() + kPrefixSize, kFunctionA, kFunctionSize);
+  auto native_module_sync = SyncCompile(full_bytes.as_vector());
+
+  // Streaming compilation should just discard its native module now and use the
+  // one inserted in the cache by sync compilation.
+  tester.OnBytesReceived(kFunctionA, kFunctionSize);
+  tester.FinishStream();
+
+  while (pending > 0) {
+    v8::platform::PumpMessageLoop(i::V8::GetCurrentPlatform(),
+                                  CcTest::isolate());
+  }
+
+  std::shared_ptr<NativeModule> native_module_streaming =
+      resolver->native_module();
+  CHECK_EQ(native_module_streaming, native_module_sync);
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/cctest/wasm/test-grow-memory.cc b/deps/v8/test/cctest/wasm/test-grow-memory.cc
index a188707cae..0bf85c2b40 100644
--- a/deps/v8/test/cctest/wasm/test-grow-memory.cc
+++ b/deps/v8/test/cctest/wasm/test-grow-memory.cc
@@ -113,7 +113,7 @@ TEST(Run_WasmModule_Buffer_Externalized_GrowMem) {
     ManuallyExternalizedBuffer external2(
         handle(memory_object->array_buffer(), isolate));
 
-    // Grow using an internal WASM bytecode.
+    // Grow using an internal Wasm bytecode.
     result = testing::RunWasmModuleForTesting(isolate, instance, 0, nullptr);
     CHECK_EQ(26, result);
     CHECK(external2.buffer_->was_detached());  // growing always detaches
diff --git a/deps/v8/test/cctest/wasm/test-liftoff-inspection.cc b/deps/v8/test/cctest/wasm/test-liftoff-inspection.cc
index 3bbc639ca5..4984bf4524 100644
--- a/deps/v8/test/cctest/wasm/test-liftoff-inspection.cc
+++ b/deps/v8/test/cctest/wasm/test-liftoff-inspection.cc
@@ -61,18 +61,69 @@ class LiftoffCompileEnvironment {
     CHECK_EQ(detected1, detected2);
   }
 
-  DebugSideTable GenerateDebugSideTable(
+  std::unique_ptr<DebugSideTable> GenerateDebugSideTable(
       std::initializer_list<ValueType> return_types,
       std::initializer_list<ValueType> param_types,
-      std::initializer_list<uint8_t> raw_function_bytes) {
+      std::initializer_list<uint8_t> raw_function_bytes,
+      std::vector<int> breakpoints = {}) {
     auto test_func = AddFunction(return_types, param_types, raw_function_bytes);
 
-    CompilationEnv env = module_builder_.CreateCompilationEnv();
-    return GenerateLiftoffDebugSideTable(CcTest::i_isolate()->allocator(), &env,
-                                         test_func.body);
+    CompilationEnv env = module_builder_.CreateCompilationEnv(
+        breakpoints.empty() ? TestingModuleBuilder::kNoDebug
+                            : TestingModuleBuilder::kDebug);
+    WasmFeatures detected;
+    std::unique_ptr<DebugSideTable> debug_side_table_via_compilation;
+    ExecuteLiftoffCompilation(
+        CcTest::i_isolate()->allocator(), &env, test_func.body, 0, nullptr,
+        &detected, VectorOf(breakpoints), &debug_side_table_via_compilation);
+
+    // If there are no breakpoint, then {ExecuteLiftoffCompilation} should
+    // provide the same debug side table.
+    if (breakpoints.empty()) {
+      std::unique_ptr<DebugSideTable> debug_side_table =
+          GenerateLiftoffDebugSideTable(CcTest::i_isolate()->allocator(), &env,
+                                        test_func.body);
+      CheckTableEquals(*debug_side_table, *debug_side_table_via_compilation);
+    }
+
+    return debug_side_table_via_compilation;
   }
 
  private:
+  static void CheckTableEquals(const DebugSideTable& a,
+                               const DebugSideTable& b) {
+    CHECK_EQ(a.num_locals(), b.num_locals());
+    CHECK(std::equal(a.entries().begin(), a.entries().end(),
+                     b.entries().begin(), b.entries().end(),
+                     &CheckEntryEquals));
+  }
+
+  static bool CheckEntryEquals(const DebugSideTable::Entry& a,
+                               const DebugSideTable::Entry& b) {
+    CHECK_EQ(a.pc_offset(), b.pc_offset());
+    CHECK(std::equal(a.values().begin(), a.values().end(), b.values().begin(),
+                     b.values().end(), &CheckValueEquals));
+    return true;
+  }
+
+  static bool CheckValueEquals(const DebugSideTable::Entry::Value& a,
+                               const DebugSideTable::Entry::Value& b) {
+    CHECK_EQ(a.type, b.type);
+    CHECK_EQ(a.kind, b.kind);
+    switch (a.kind) {
+      case DebugSideTable::Entry::kConstant:
+        CHECK_EQ(a.i32_const, b.i32_const);
+        break;
+      case DebugSideTable::Entry::kRegister:
+        CHECK_EQ(a.reg_code, b.reg_code);
+        break;
+      case DebugSideTable::Entry::kStack:
+        CHECK_EQ(a.stack_offset, b.stack_offset);
+        break;
+    }
+    return true;
+  }
+
   OwnedVector<uint8_t> GenerateFunctionBody(
       std::initializer_list<uint8_t> raw_function_bytes) {
     // Build the function bytes by prepending the locals decl and appending an
@@ -122,30 +173,52 @@ class LiftoffCompileEnvironment {
 };
 
 struct DebugSideTableEntry {
-  std::vector<ValueType> stack_types;
-  std::vector<std::pair<int, int>> constants;
+  std::vector<DebugSideTable::Entry::Value> values;
+
+  // Construct via vector or implicitly via initializer list.
+  explicit DebugSideTableEntry(std::vector<DebugSideTable::Entry::Value> values)
+      : values(std::move(values)) {}
+  DebugSideTableEntry(
+      std::initializer_list<DebugSideTable::Entry::Value> values)
+      : values(values) {}
 
   bool operator==(const DebugSideTableEntry& other) const {
-    return stack_types == other.stack_types && constants == other.constants;
+    if (values.size() != other.values.size()) return false;
+    for (size_t i = 0; i < values.size(); ++i) {
+      if (values[i].type != other.values[i].type) return false;
+      if (values[i].kind != other.values[i].kind) return false;
+      // Stack offsets and register codes are platform dependent, so only check
+      // constants here.
+      if (values[i].kind == DebugSideTable::Entry::kConstant &&
+          values[i].i32_const != other.values[i].i32_const) {
+        return false;
+      }
+    }
+    return true;
   }
 };
 
 // Debug builds will print the vector of DebugSideTableEntry.
 #ifdef DEBUG
 std::ostream& operator<<(std::ostream& out, const DebugSideTableEntry& entry) {
-  out << "{stack types [";
+  out << "{";
   const char* comma = "";
-  for (ValueType type : entry.stack_types) {
-    out << comma << ValueTypes::TypeName(type);
-    comma = ", ";
-  }
-  comma = "";
-  out << "], constants: [";
-  for (auto& c : entry.constants) {
-    out << comma << "<" << c.first << ", " << c.second << ">";
+  for (auto& v : entry.values) {
+    out << comma << v.type.type_name() << " ";
+    switch (v.kind) {
+      case DebugSideTable::Entry::kConstant:
+        out << "const:" << v.i32_const;
+        break;
+      case DebugSideTable::Entry::kRegister:
+        out << "reg";
+        break;
+      case DebugSideTable::Entry::kStack:
+        out << "stack";
+        break;
+    }
     comma = ", ";
   }
-  return out << "]}";
+  return out << "}";
 }
 
 std::ostream& operator<<(std::ostream& out,
@@ -154,28 +227,36 @@ std::ostream& operator<<(std::ostream& out,
 }
 #endif  // DEBUG
 
-void CheckDebugSideTable(std::vector<ValueType> expected_local_types,
-                         std::vector<DebugSideTableEntry> expected_entries,
-                         const wasm::DebugSideTable& debug_side_table) {
-  std::vector<ValueType> local_types;
-  for (int i = 0; i < debug_side_table.num_locals(); ++i) {
-    local_types.push_back(debug_side_table.local_type(i));
-  }
+// Named constructors to make the tests more readable.
+DebugSideTable::Entry::Value Constant(ValueType type, int32_t constant) {
+  DebugSideTable::Entry::Value value;
+  value.type = type;
+  value.kind = DebugSideTable::Entry::kConstant;
+  value.i32_const = constant;
+  return value;
+}
+DebugSideTable::Entry::Value Register(ValueType type) {
+  DebugSideTable::Entry::Value value;
+  value.type = type;
+  value.kind = DebugSideTable::Entry::kRegister;
+  return value;
+}
+DebugSideTable::Entry::Value Stack(ValueType type) {
+  DebugSideTable::Entry::Value value;
+  value.type = type;
+  value.kind = DebugSideTable::Entry::kStack;
+  return value;
+}
+
+void CheckDebugSideTable(std::vector<DebugSideTableEntry> expected_entries,
+                         const wasm::DebugSideTable* debug_side_table) {
   std::vector<DebugSideTableEntry> entries;
-  for (auto& entry : debug_side_table.entries()) {
-    std::vector<ValueType> stack_types;
-    for (int i = 0; i < entry.stack_height(); ++i) {
-      stack_types.push_back(entry.stack_type(i));
-    }
-    std::vector<std::pair<int, int>> constants;
-    int locals_plus_stack =
-        debug_side_table.num_locals() + entry.stack_height();
-    for (int i = 0; i < locals_plus_stack; ++i) {
-      if (entry.IsConstant(i)) constants.emplace_back(i, entry.GetConstant(i));
-    }
-    entries.push_back({std::move(stack_types), std::move(constants)});
+  for (auto& entry : debug_side_table->entries()) {
+    auto values = entry.values();
+    entries.push_back(
+        DebugSideTableEntry{std::vector<DebugSideTable::Entry::Value>{
+            values.begin(), values.end()}});
   }
-  CHECK_EQ(expected_local_types, local_types);
   CHECK_EQ(expected_entries, entries);
 }
 
@@ -223,12 +304,12 @@ TEST(Liftoff_debug_side_table_simple) {
   auto debug_side_table = env.GenerateDebugSideTable(
       {kWasmI32}, {kWasmI32, kWasmI32},
       {WASM_I32_ADD(WASM_GET_LOCAL(0), WASM_GET_LOCAL(1))});
-  CheckDebugSideTable({kWasmI32, kWasmI32},
-                      {
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // OOL stack check, locals spilled, stack empty.
+          {Stack(kWasmI32), Stack(kWasmI32)},
+      },
+      debug_side_table.get());
 }
 
 TEST(Liftoff_debug_side_table_call) {
@@ -237,14 +318,14 @@ TEST(Liftoff_debug_side_table_call) {
       {kWasmI32}, {kWasmI32},
       {WASM_I32_ADD(WASM_CALL_FUNCTION(0, WASM_GET_LOCAL(0)),
                     WASM_GET_LOCAL(0))});
-  CheckDebugSideTable({kWasmI32},
-                      {
-                          // call, stack: {}
-                          {{}, {}},
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // call, local spilled, stack empty.
+          {Stack(kWasmI32)},
+          // OOL stack check, local spilled, stack empty.
+          {Stack(kWasmI32)},
+      },
+      debug_side_table.get());
 }
 
 TEST(Liftoff_debug_side_table_call_const) {
@@ -255,14 +336,14 @@ TEST(Liftoff_debug_side_table_call_const) {
       {WASM_SET_LOCAL(0, WASM_I32V_1(kConst)),
        WASM_I32_ADD(WASM_CALL_FUNCTION(0, WASM_GET_LOCAL(0)),
                     WASM_GET_LOCAL(0))});
-  CheckDebugSideTable({kWasmI32},
-                      {
-                          // call, stack: {}, local0 is kConst
-                          {{}, {{0, kConst}}},
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // call, local is kConst.
+          {Constant(kWasmI32, kConst)},
+          // OOL stack check, local spilled.
+          {Stack(kWasmI32)},
+      },
+      debug_side_table.get());
 }
 
 TEST(Liftoff_debug_side_table_indirect_call) {
@@ -272,18 +353,18 @@ TEST(Liftoff_debug_side_table_indirect_call) {
       {kWasmI32}, {kWasmI32},
       {WASM_I32_ADD(WASM_CALL_INDIRECT(0, WASM_I32V_1(47), WASM_GET_LOCAL(0)),
                     WASM_GET_LOCAL(0))});
-  CheckDebugSideTable({kWasmI32},
-                      {
-                          // indirect call, stack: {}
-                          {{}, {}},
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                          // OOL trap (invalid index), stack: {kConst}
-                          {{kWasmI32}, {{1, kConst}}},
-                          // OOL trap (sig mismatch), stack: {kConst}
-                          {{kWasmI32}, {{1, kConst}}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // indirect call, local spilled, stack empty.
+          {Stack(kWasmI32)},
+          // OOL stack check, local spilled, stack empty.
+          {Stack(kWasmI32)},
+          // OOL trap (invalid index), local spilled, stack has {kConst}.
+          {Stack(kWasmI32), Constant(kWasmI32, kConst)},
+          // OOL trap (sig mismatch), local spilled, stack has {kConst}.
+          {Stack(kWasmI32), Constant(kWasmI32, kConst)},
+      },
+      debug_side_table.get());
 }
 
 TEST(Liftoff_debug_side_table_loop) {
@@ -292,14 +373,14 @@ TEST(Liftoff_debug_side_table_loop) {
   auto debug_side_table = env.GenerateDebugSideTable(
       {kWasmI32}, {kWasmI32},
       {WASM_I32V_1(kConst), WASM_LOOP(WASM_BR_IF(0, WASM_GET_LOCAL(0)))});
-  CheckDebugSideTable({kWasmI32},
-                      {
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                          // OOL loop stack check, stack: {kConst}
-                          {{kWasmI32}, {{1, kConst}}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // OOL stack check, local spilled, stack empty.
+          {Stack(kWasmI32)},
+          // OOL loop stack check, local spilled, stack has {kConst}.
+          {Stack(kWasmI32), Constant(kWasmI32, kConst)},
+      },
+      debug_side_table.get());
 }
 
 TEST(Liftoff_debug_side_table_trap) {
@@ -307,16 +388,39 @@ TEST(Liftoff_debug_side_table_trap) {
   auto debug_side_table = env.GenerateDebugSideTable(
       {kWasmI32}, {kWasmI32, kWasmI32},
       {WASM_I32_DIVS(WASM_GET_LOCAL(0), WASM_GET_LOCAL(1))});
-  CheckDebugSideTable({kWasmI32, kWasmI32},
-                      {
-                          // OOL stack check, stack: {}
-                          {{}, {}},
-                          // OOL trap (div by zero), stack: {}
-                          {{}, {}},
-                          // OOL trap (result unrepresentable), stack: {}
-                          {{}, {}},
-                      },
-                      debug_side_table);
+  CheckDebugSideTable(
+      {
+          // OOL stack check, local spilled, stack empty.
+          {Stack(kWasmI32), Stack(kWasmI32)},
+          // OOL trap (div by zero), locals spilled, stack empty.
+          {Stack(kWasmI32), Stack(kWasmI32)},
+          // OOL trap (result unrepresentable), locals spilled, stack empty.
+          {Stack(kWasmI32), Stack(kWasmI32)},
+      },
+      debug_side_table.get());
+}
+
+TEST(Liftoff_breakpoint_simple) {
+  LiftoffCompileEnvironment env;
+  // Set two breakpoints. At both locations, values are live in registers.
+  auto debug_side_table = env.GenerateDebugSideTable(
+      {kWasmI32}, {kWasmI32, kWasmI32},
+      {WASM_I32_ADD(WASM_GET_LOCAL(0), WASM_GET_LOCAL(1))},
+      {
+          1,  // break at beginning of function (first local.get)
+          5   // break at i32.add
+      });
+  CheckDebugSideTable(
+      {
+          // First break point, locals in registers.
+          {Register(kWasmI32), Register(kWasmI32)},
+          // Second break point, locals and two stack values in registers.
+          {Register(kWasmI32), Register(kWasmI32), Register(kWasmI32),
+           Register(kWasmI32)},
+          // OOL stack check, locals spilled, stack empty.
+          {Stack(kWasmI32), Stack(kWasmI32)},
+      },
+      debug_side_table.get());
 }
 
 }  // namespace wasm
diff --git a/deps/v8/test/cctest/wasm/test-run-wasm-64.cc b/deps/v8/test/cctest/wasm/test-run-wasm-64.cc
index 94fa0a31b2..f6cdff61ba 100644
--- a/deps/v8/test/cctest/wasm/test-run-wasm-64.cc
+++ b/deps/v8/test/cctest/wasm/test-run-wasm-64.cc
@@ -1419,7 +1419,7 @@ WASM_EXEC_TEST(StoreMem_offset_oob_i64) {
                                    WASM_LOAD_MEM(machineTypes[m], WASM_ZERO)),
           WASM_ZERO);
 
-    byte memsize = ValueTypes::MemSize(machineTypes[m]);
+    byte memsize = machineTypes[m].MemSize();
     uint32_t boundary = num_bytes - 8 - memsize;
     CHECK_EQ(0, r.Call(boundary));  // in bounds.
     CHECK_EQ(0, memcmp(&memory[0], &memory[8 + boundary], memsize));
@@ -1536,9 +1536,9 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
     // Build the selector function.
     // =========================================================================
     FunctionSig::Builder b(&zone, 1, num_params);
-    b.AddReturn(ValueTypes::ValueTypeFor(result));
+    b.AddReturn(ValueType::For(result));
     for (int i = 0; i < num_params; i++) {
-      b.AddParam(ValueTypes::ValueTypeFor(memtypes[i]));
+      b.AddParam(ValueType::For(memtypes[i]));
     }
     WasmFunctionCompiler& t = r.NewFunction(b.Build());
     BUILD(t, WASM_GET_LOCAL(which));
@@ -1558,7 +1558,7 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
     ADD_CODE(code, WASM_CALL_FUNCTION0(t.function_index()));
 
     // Store the result in a local.
-    byte local_index = r.AllocateLocal(ValueTypes::ValueTypeFor(result));
+    byte local_index = r.AllocateLocal(ValueType::For(result));
     ADD_CODE(code, kExprLocalSet, local_index);
 
     // Store the result in memory.
@@ -1575,7 +1575,7 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
       r.builder().RandomizeMemory();
       CHECK_EQ(kExpected, r.Call());
 
-      int size = ValueTypes::MemSize(result);
+      int size = result.MemSize();
       for (int i = 0; i < size; i++) {
         int base = (which + 1) * kElemSize;
         byte expected = r.builder().raw_mem_at<byte>(base + i);
diff --git a/deps/v8/test/cctest/wasm/test-run-wasm-atomics64.cc b/deps/v8/test/cctest/wasm/test-run-wasm-atomics64.cc
index 082c5d07c9..178f86bac9 100644
--- a/deps/v8/test/cctest/wasm/test-run-wasm-atomics64.cc
+++ b/deps/v8/test/cctest/wasm/test-run-wasm-atomics64.cc
@@ -752,6 +752,52 @@ WASM_EXEC_TEST(I64AtomicAddUseOnlyHighWord) {
   CHECK_EQ(0x12345678, r.Call());
 }
 
+WASM_EXEC_TEST(I64AtomicCompareExchangeUseOnlyLowWord) {
+  EXPERIMENTAL_FLAG_SCOPE(threads);
+  WasmRunner<uint32_t> r(execution_tier);
+  uint64_t* memory =
+      r.builder().AddMemoryElems<uint64_t>(kWasmPageSize / sizeof(uint64_t));
+  memory[1] = 0x1234567890abcdeful;
+  r.builder().SetHasSharedMemory();
+  // Test that we can use just the low word of an I64AtomicLoad.
+  BUILD(r, WASM_I32_CONVERT_I64(WASM_ATOMICS_TERNARY_OP(
+               kExprI64AtomicCompareExchange, WASM_I32V(8), WASM_I64V(1),
+               WASM_I64V(memory[1]), MachineRepresentation::kWord64)));
+  CHECK_EQ(0x90abcdef, r.Call());
+}
+
+WASM_EXEC_TEST(I64AtomicCompareExchangeUseOnlyHighWord) {
+  EXPERIMENTAL_FLAG_SCOPE(threads);
+  WasmRunner<uint32_t> r(execution_tier);
+  uint64_t* memory =
+      r.builder().AddMemoryElems<uint64_t>(kWasmPageSize / sizeof(uint64_t));
+  memory[1] = 0x1234567890abcdeful;
+  r.builder().SetHasSharedMemory();
+  // Test that we can use just the high word of an I64AtomicLoad.
+  BUILD(r, WASM_I32_CONVERT_I64(WASM_I64_ROR(
+               WASM_ATOMICS_TERNARY_OP(
+                   kExprI64AtomicCompareExchange, WASM_I32V(8), WASM_I64V(1),
+                   WASM_I64V(memory[1]), MachineRepresentation::kWord64),
+               WASM_I64V(32))));
+  CHECK_EQ(0x12345678, r.Call());
+}
+
+WASM_EXEC_TEST(I64AtomicCompareExchange32UZeroExtended) {
+  EXPERIMENTAL_FLAG_SCOPE(threads);
+  WasmRunner<uint32_t> r(execution_tier);
+  uint64_t* memory =
+      r.builder().AddMemoryElems<uint64_t>(kWasmPageSize / sizeof(uint64_t));
+  memory[1] = 0;
+  r.builder().SetHasSharedMemory();
+  // Test that the high word of the expected value is cleared in the return
+  // value.
+  BUILD(r, WASM_I64_EQZ(WASM_ATOMICS_TERNARY_OP(
+               kExprI64AtomicCompareExchange32U, WASM_I32V(8),
+               WASM_I64V(0x1234567800000000), WASM_I64V(0),
+               MachineRepresentation::kWord32)));
+  CHECK_EQ(1, r.Call());
+}
+
 }  // namespace test_run_wasm_atomics_64
 }  // namespace wasm
 }  // namespace internal
diff --git a/deps/v8/test/cctest/wasm/test-run-wasm-exceptions.cc b/deps/v8/test/cctest/wasm/test-run-wasm-exceptions.cc
index 745196210a..cddc6f7468 100644
--- a/deps/v8/test/cctest/wasm/test-run-wasm-exceptions.cc
+++ b/deps/v8/test/cctest/wasm/test-run-wasm-exceptions.cc
@@ -160,17 +160,15 @@ WASM_EXEC_TEST(TryCatchTrapTypeError) {
 
 namespace {
 
-// TODO(8729): The semantics of this are not yet specified and might change,
-// this test aims at keeping semantics of various execution tiers consistent.
-void TestTryCatchTrap(byte* code, size_t code_size,
-                      ExecutionTier execution_tier) {
+void TestTrapNotCaught(byte* code, size_t code_size,
+                       ExecutionTier execution_tier) {
   TestSignatures sigs;
   EXPERIMENTAL_FLAG_SCOPE(eh);
-  WasmRunner<uint32_t, uint32_t> r(execution_tier, nullptr, "main",
-                                   kRuntimeExceptionSupport);
+  WasmRunner<uint32_t> r(execution_tier, nullptr, "main",
+                         kRuntimeExceptionSupport);
   r.builder().AddMemory(kWasmPageSize);
-  constexpr uint32_t kResult0 = 23;
-  constexpr uint32_t kResult1 = 42;
+  constexpr uint32_t kResultSuccess = 23;
+  constexpr uint32_t kResultCaught = 47;
 
   // Build a trapping helper function.
   WasmFunctionCompiler& trap_func = r.NewFunction(sigs.i_ii());
@@ -179,39 +177,36 @@ void TestTryCatchTrap(byte* code, size_t code_size,
   // Build the main test function.
   BUILD(r, WASM_TRY_CATCH_T(
                kWasmI32,
-               WASM_STMTS(WASM_I32V(kResult1),
-                          WASM_IF(WASM_I32_EQZ(WASM_GET_LOCAL(0)),
-                                  WASM_STMTS(WASM_CALL_FUNCTION(
-                                                 trap_func.function_index(),
-                                                 WASM_I32V(7), WASM_I32V(9)),
-                                             WASM_DROP))),
-               WASM_STMTS(WASM_DROP, WASM_I32V(kResult0))));
+               WASM_STMTS(WASM_I32V(kResultSuccess),
+                          WASM_CALL_FUNCTION(trap_func.function_index(),
+                                             WASM_I32V(7), WASM_I32V(9)),
+                          WASM_DROP),
+               WASM_STMTS(WASM_DROP, WASM_I32V(kResultCaught))));
 
   // Need to call through JS to allow for creation of stack traces.
-  r.CheckCallViaJS(kResult0, 0);
-  r.CheckCallViaJS(kResult1, 1);
+  r.CheckCallViaJSTraps();
 }
 
 }  // namespace
 
 WASM_EXEC_TEST(TryCatchTrapUnreachable) {
   byte code[] = {WASM_UNREACHABLE};
-  TestTryCatchTrap(code, arraysize(code), execution_tier);
+  TestTrapNotCaught(code, arraysize(code), execution_tier);
 }
 
 WASM_EXEC_TEST(TryCatchTrapMemOutOfBounds) {
   byte code[] = {WASM_LOAD_MEM(MachineType::Int32(), WASM_I32V_1(-1))};
-  TestTryCatchTrap(code, arraysize(code), execution_tier);
+  TestTrapNotCaught(code, arraysize(code), execution_tier);
 }
 
 WASM_EXEC_TEST(TryCatchTrapDivByZero) {
   byte code[] = {WASM_I32_DIVS(WASM_GET_LOCAL(0), WASM_I32V_1(0))};
-  TestTryCatchTrap(code, arraysize(code), execution_tier);
+  TestTrapNotCaught(code, arraysize(code), execution_tier);
 }
 
 WASM_EXEC_TEST(TryCatchTrapRemByZero) {
   byte code[] = {WASM_I32_REMS(WASM_GET_LOCAL(0), WASM_I32V_1(0))};
-  TestTryCatchTrap(code, arraysize(code), execution_tier);
+  TestTrapNotCaught(code, arraysize(code), execution_tier);
 }
 
 }  // namespace test_run_wasm_exceptions
diff --git a/deps/v8/test/cctest/wasm/test-run-wasm-simd.cc b/deps/v8/test/cctest/wasm/test-run-wasm-simd.cc
index c8cc836b87..23ab076e4a 100644
--- a/deps/v8/test/cctest/wasm/test-run-wasm-simd.cc
+++ b/deps/v8/test/cctest/wasm/test-run-wasm-simd.cc
@@ -48,23 +48,6 @@ using Int8ShiftOp = int8_t (*)(int8_t, int);
     EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
     RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kTurbofan);    \
   }                                                                   \
-  TEST(RunWasm_##name##_interpreter) {                                \
-    EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
-    RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kInterpreter); \
-  }                                                                   \
-  TEST(RunWasm_##name##_simd_lowered) {                               \
-    EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
-    RunWasm_##name##_Impl(kLowerSimd, ExecutionTier::kTurbofan);      \
-  }                                                                   \
-  void RunWasm_##name##_Impl(LowerSimd lower_simd, ExecutionTier execution_tier)
-
-#define WASM_SIMD_TEST_WITH_LIFTOFF(name)                             \
-  void RunWasm_##name##_Impl(LowerSimd lower_simd,                    \
-                             ExecutionTier execution_tier);           \
-  TEST(RunWasm_##name##_turbofan) {                                   \
-    EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
-    RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kTurbofan);    \
-  }                                                                   \
   TEST(RunWasm_##name##_liftoff) {                                    \
     EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
     RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kLiftoff);     \
@@ -305,6 +288,11 @@ T AndNot(T a, T b) {
   return a & ~b;
 }
 
+template <typename T>
+T Abs(T a) {
+  return std::abs(a);
+}
+
 // only used for F64x2 tests below
 int64_t Equal(double a, double b) { return a == b ? -1 : 0; }
 
@@ -318,7 +306,7 @@ int64_t Less(double a, double b) { return a < b ? -1 : 0; }
 
 int64_t LessEqual(double a, double b) { return a <= b ? -1 : 0; }
 
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 // Only used for qfma and qfms tests below.
 
 // FMOperation holds the params (a, b, c) for a Multiply-Add or
@@ -393,15 +381,17 @@ static constexpr Vector<const FMOperation<T>> qfms_vector() {
   return ArrayVector(qfms_array<T>);
 }
 
-// Fused results only when fma3 feature is enabled, and running on TurboFan.
+// Fused results only when fma3 feature is enabled, and running on TurboFan or
+// Liftoff (which can fall back to TurboFan if FMA is not implemented).
 bool ExpectFused(ExecutionTier tier) {
 #ifdef V8_TARGET_ARCH_X64
-  return CpuFeatures::IsSupported(FMA3) && (tier == ExecutionTier::kTurbofan);
+  return CpuFeatures::IsSupported(FMA3) &&
+         (tier == ExecutionTier::kTurbofan || tier == ExecutionTier::kLiftoff);
 #else
-  return (tier == ExecutionTier::kTurbofan);
+  return (tier == ExecutionTier::kTurbofan || tier == ExecutionTier::kLiftoff);
 #endif
 }
-#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 
 }  // namespace
 
@@ -419,6 +409,9 @@ bool ExpectFused(ExecutionTier tier) {
           WASM_RETURN1(WASM_ZERO))
 
 #define TO_BYTE(val) static_cast<byte>(val)
+// TODO(v8:10258): We have support for emitting multi-byte opcodes now, so this
+// can change to simply, op, once the decoder is fixed to decode multi byte
+// opcodes.
 #define WASM_SIMD_OP(op) kSimdPrefix, TO_BYTE(op)
 #define WASM_SIMD_SPLAT(Type, ...) __VA_ARGS__, WASM_SIMD_OP(kExpr##Type##Splat)
 #define WASM_SIMD_UNOP(op, x) x, WASM_SIMD_OP(op)
@@ -519,6 +512,11 @@ bool ExpectFused(ExecutionTier tier) {
     EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
     RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kTurbofan);    \
   }                                                                   \
+  TEST(RunWasm_##name##_liftoff) {                                    \
+    if (!CpuFeatures::SupportsWasmSimd128()) return;                  \
+    EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
+    RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kLiftoff);     \
+  }                                                                   \
   TEST(RunWasm_##name##_interpreter) {                                \
     EXPERIMENTAL_FLAG_SCOPE(simd);                                    \
     RunWasm_##name##_Impl(kNoLowerSimd, ExecutionTier::kInterpreter); \
@@ -550,7 +548,7 @@ WASM_SIMD_TEST(S128Globals) {
   // Set up a global to hold input and output vectors.
   int32_t* g0 = r.builder().AddGlobal<int32_t>(kWasmS128);
   int32_t* g1 = r.builder().AddGlobal<int32_t>(kWasmS128);
-  BUILD(r, WASM_SET_GLOBAL(1, WASM_GET_GLOBAL(0)), WASM_ONE);
+  BUILD_V(r, WASM_SET_GLOBAL(1, WASM_GET_GLOBAL(0)), WASM_ONE);
 
   FOR_INT32_INPUTS(x) {
     for (int i = 0; i < 4; i++) {
@@ -565,7 +563,7 @@ WASM_SIMD_TEST(S128Globals) {
   }
 }
 
-WASM_SIMD_TEST_WITH_LIFTOFF(F32x4Splat) {
+WASM_SIMD_TEST(F32x4Splat) {
   WasmRunner<int32_t, float> r(execution_tier, lower_simd);
   // Set up a global to hold output vector.
   float* g = r.builder().AddGlobal<float>(kWasmS128);
@@ -753,11 +751,13 @@ WASM_SIMD_TEST(F32x4Sqrt) {
 }
 
 WASM_SIMD_TEST(F32x4RecipApprox) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   RunF32x4UnOpTest(execution_tier, lower_simd, kExprF32x4RecipApprox,
                    base::Recip, false /* !exact */);
 }
 
 WASM_SIMD_TEST(F32x4RecipSqrtApprox) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   RunF32x4UnOpTest(execution_tier, lower_simd, kExprF32x4RecipSqrtApprox,
                    base::RecipSqrt, false /* !exact */);
 }
@@ -883,8 +883,9 @@ WASM_SIMD_TEST(F32x4Le) {
   RunF32x4CompareOpTest(execution_tier, lower_simd, kExprF32x4Le, LessEqual);
 }
 
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 WASM_SIMD_TEST_NO_LOWERING(F32x4Qfma) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   WasmRunner<int32_t, float, float, float> r(execution_tier, lower_simd);
   // Set up global to hold mask output.
   float* g = r.builder().AddGlobal<float>(kWasmS128);
@@ -909,6 +910,7 @@ WASM_SIMD_TEST_NO_LOWERING(F32x4Qfma) {
 }
 
 WASM_SIMD_TEST_NO_LOWERING(F32x4Qfms) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   WasmRunner<int32_t, float, float, float> r(execution_tier, lower_simd);
   // Set up global to hold mask output.
   float* g = r.builder().AddGlobal<float>(kWasmS128);
@@ -931,15 +933,15 @@ WASM_SIMD_TEST_NO_LOWERING(F32x4Qfms) {
     }
   }
 }
-#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 
 WASM_SIMD_TEST_NO_LOWERING(I64x2Splat) {
   WasmRunner<int32_t, int64_t> r(execution_tier, lower_simd);
   // Set up a global to hold output vector.
   int64_t* g = r.builder().AddGlobal<int64_t>(kWasmS128);
   byte param1 = 0;
-  BUILD(r, WASM_SET_GLOBAL(0, WASM_SIMD_I64x2_SPLAT(WASM_GET_LOCAL(param1))),
-        WASM_ONE);
+  BUILD_V(r, WASM_SET_GLOBAL(0, WASM_SIMD_I64x2_SPLAT(WASM_GET_LOCAL(param1))),
+          WASM_ONE);
 
   FOR_INT64_INPUTS(x) {
     r.Call(x);
@@ -1014,22 +1016,28 @@ void RunI64x2ShiftOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   // Intentionally shift by 64, should be no-op.
   for (int shift = 1; shift <= 64; shift++) {
     WasmRunner<int32_t, int64_t> r(execution_tier, lower_simd);
-    int64_t* g = r.builder().AddGlobal<int64_t>(kWasmS128);
+    int32_t* memory = r.builder().AddMemoryElems<int32_t>(1);
+    int64_t* g_imm = r.builder().AddGlobal<int64_t>(kWasmS128);
+    int64_t* g_mem = r.builder().AddGlobal<int64_t>(kWasmS128);
     byte value = 0;
-    byte shift_index = r.AllocateLocal(kWasmI32);
-    byte simd1 = r.AllocateLocal(kWasmS128);
-    BUILD(r,
-          WASM_SET_LOCAL(simd1, WASM_SIMD_I64x2_SPLAT(WASM_GET_LOCAL(value))),
-          WASM_SET_LOCAL(shift_index, WASM_I32V(shift)),
-          WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd1),
-                                                WASM_GET_LOCAL(shift_index))),
-          WASM_ONE);
+    byte simd = r.AllocateLocal(kWasmS128);
+    // Shift using an immediate, and shift using a value loaded from memory.
+    BUILD(
+        r, WASM_SET_LOCAL(simd, WASM_SIMD_I64x2_SPLAT(WASM_GET_LOCAL(value))),
+        WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd),
+                                              WASM_I32V(shift))),
+        WASM_SET_GLOBAL(1, WASM_SIMD_SHIFT_OP(
+                               opcode, WASM_GET_LOCAL(simd),
+                               WASM_LOAD_MEM(MachineType::Int32(), WASM_ZERO))),
+        WASM_ONE);
 
+    r.builder().WriteMemory(&memory[0], shift);
     FOR_INT64_INPUTS(x) {
       r.Call(x);
       int64_t expected = expected_op(x, shift);
       for (int i = 0; i < 2; i++) {
-        CHECK_EQ(expected, ReadLittleEndianValue<int64_t>(&g[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int64_t>(&g_imm[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int64_t>(&g_mem[i]));
       }
     }
   }
@@ -1052,6 +1060,7 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2ShrU) {
 
 void RunI64x2BinOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
                        WasmOpcode opcode, Int64BinOp expected_op) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   WasmRunner<int32_t, int64_t, int64_t> r(execution_tier, lower_simd);
   // Global to hold output.
   int64_t* g = r.builder().AddGlobal<int64_t>(kWasmS128);
@@ -1086,7 +1095,7 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2Sub) {
                     base::SubWithWraparound);
 }
 
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 WASM_SIMD_TEST_NO_LOWERING(I64x2Eq) {
   RunI64x2BinOpTest(execution_tier, lower_simd, kExprI64x2Eq, Equal);
 }
@@ -1128,7 +1137,7 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2GeU) {
   RunI64x2BinOpTest(execution_tier, lower_simd, kExprI64x2GeU,
                     UnsignedGreaterEqual);
 }
-#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 
 WASM_SIMD_TEST_NO_LOWERING(F64x2Splat) {
   WasmRunner<int32_t, double> r(execution_tier, lower_simd);
@@ -1197,7 +1206,7 @@ WASM_SIMD_TEST_NO_LOWERING(F64x2ReplaceLane) {
   CHECK_EQ(1., ReadLittleEndianValue<double>(&g1[1]));
 }
 
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 WASM_SIMD_TEST_NO_LOWERING(F64x2ExtractLaneWithI64x2) {
   WasmRunner<int64_t> r(execution_tier, lower_simd);
   BUILD(r, WASM_IF_ELSE_L(
@@ -1217,7 +1226,7 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2ExtractWithF64x2) {
                WASM_I64V(1), WASM_I64V(0)));
   CHECK_EQ(1, r.Call());
 }
-#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 
 bool IsExtreme(double x) {
   double abs_x = std::fabs(x);
@@ -1480,7 +1489,7 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2Mul) {
                     base::MulWithWraparound);
 }
 
-#if V8_TARGET_ARCH_X64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_S390X
 WASM_SIMD_TEST_NO_LOWERING(I64x2MinS) {
   RunI64x2BinOpTest(execution_tier, lower_simd, kExprI64x2MinS, Minimum);
 }
@@ -1498,10 +1507,11 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2MaxU) {
   RunI64x2BinOpTest(execution_tier, lower_simd, kExprI64x2MaxU,
                     UnsignedMaximum);
 }
-#endif  // V8_TARGET_ARCH_X64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_S390X
 
-#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 WASM_SIMD_TEST_NO_LOWERING(F64x2Qfma) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   WasmRunner<int32_t, double, double, double> r(execution_tier, lower_simd);
   // Set up global to hold mask output.
   double* g = r.builder().AddGlobal<double>(kWasmS128);
@@ -1526,6 +1536,7 @@ WASM_SIMD_TEST_NO_LOWERING(F64x2Qfma) {
 }
 
 WASM_SIMD_TEST_NO_LOWERING(F64x2Qfms) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   WasmRunner<int32_t, double, double, double> r(execution_tier, lower_simd);
   // Set up global to hold mask output.
   double* g = r.builder().AddGlobal<double>(kWasmS128);
@@ -1548,7 +1559,7 @@ WASM_SIMD_TEST_NO_LOWERING(F64x2Qfms) {
     }
   }
 }
-#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
+#endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_S390X
 
 WASM_SIMD_TEST(I32x4Splat) {
   WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
@@ -1650,6 +1661,68 @@ WASM_SIMD_TEST(I16x8ReplaceLane) {
   }
 }
 
+#if V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_ARM
+WASM_SIMD_TEST_NO_LOWERING(I8x16BitMask) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
+  WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
+  byte value1 = r.AllocateLocal(kWasmS128);
+
+  BUILD(r, WASM_SET_LOCAL(value1, WASM_SIMD_I8x16_SPLAT(WASM_GET_LOCAL(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I8x16_REPLACE_LANE(
+                                   0, WASM_GET_LOCAL(value1), WASM_I32V(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I8x16_REPLACE_LANE(
+                                   1, WASM_GET_LOCAL(value1), WASM_I32V(-1))),
+        WASM_SIMD_UNOP(kExprI8x16BitMask, WASM_GET_LOCAL(value1)));
+
+  FOR_INT8_INPUTS(x) {
+    int32_t actual = r.Call(x);
+    // Lane 0 is always 0 (positive), lane 1 is always -1.
+    int32_t expected = std::signbit(static_cast<double>(x)) ? 0xFFFE : 0x0002;
+    CHECK_EQ(actual, expected);
+  }
+}
+
+WASM_SIMD_TEST_NO_LOWERING(I16x8BitMask) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
+  WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
+  byte value1 = r.AllocateLocal(kWasmS128);
+
+  BUILD(r, WASM_SET_LOCAL(value1, WASM_SIMD_I16x8_SPLAT(WASM_GET_LOCAL(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I16x8_REPLACE_LANE(
+                                   0, WASM_GET_LOCAL(value1), WASM_I32V(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I16x8_REPLACE_LANE(
+                                   1, WASM_GET_LOCAL(value1), WASM_I32V(-1))),
+        WASM_SIMD_UNOP(kExprI16x8BitMask, WASM_GET_LOCAL(value1)));
+
+  FOR_INT16_INPUTS(x) {
+    int32_t actual = r.Call(x);
+    // Lane 0 is always 0 (positive), lane 1 is always -1.
+    int32_t expected = std::signbit(static_cast<double>(x)) ? 0xFE : 2;
+    CHECK_EQ(actual, expected);
+  }
+}
+
+WASM_SIMD_TEST_NO_LOWERING(I32x4BitMask) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
+  WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
+  byte value1 = r.AllocateLocal(kWasmS128);
+
+  BUILD(r, WASM_SET_LOCAL(value1, WASM_SIMD_I32x4_SPLAT(WASM_GET_LOCAL(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I32x4_REPLACE_LANE(
+                                   0, WASM_GET_LOCAL(value1), WASM_I32V(0))),
+        WASM_SET_LOCAL(value1, WASM_SIMD_I32x4_REPLACE_LANE(
+                                   1, WASM_GET_LOCAL(value1), WASM_I32V(-1))),
+        WASM_SIMD_UNOP(kExprI32x4BitMask, WASM_GET_LOCAL(value1)));
+
+  FOR_INT32_INPUTS(x) {
+    int32_t actual = r.Call(x);
+    // Lane 0 is always 0 (positive), lane 1 is always -1.
+    int32_t expected = std::signbit(static_cast<double>(x)) ? 0xE : 2;
+    CHECK_EQ(actual, expected);
+  }
+}
+#endif  // V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_ARM
+
 WASM_SIMD_TEST(I8x16Splat) {
   WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
   // Set up a global to hold output vector.
@@ -1828,6 +1901,10 @@ WASM_SIMD_TEST(I32x4Neg) {
                    base::NegateWithWraparound);
 }
 
+WASM_SIMD_TEST(I32x4Abs) {
+  RunI32x4UnOpTest(execution_tier, lower_simd, kExprI32x4Abs, Abs);
+}
+
 WASM_SIMD_TEST(S128Not) {
   RunI32x4UnOpTest(execution_tier, lower_simd, kExprS128Not, Not);
 }
@@ -1955,21 +2032,28 @@ void RunI32x4ShiftOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   // Intentionally shift by 32, should be no-op.
   for (int shift = 1; shift <= 32; shift++) {
     WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
-    int32_t* g = r.builder().AddGlobal<int32_t>(kWasmS128);
+    int32_t* memory = r.builder().AddMemoryElems<int32_t>(1);
+    int32_t* g_imm = r.builder().AddGlobal<int32_t>(kWasmS128);
+    int32_t* g_mem = r.builder().AddGlobal<int32_t>(kWasmS128);
     byte value = 0;
-    byte shift_index = r.AllocateLocal(kWasmI32);
-    byte simd1 = r.AllocateLocal(kWasmS128);
-    BUILD(r, WASM_SET_LOCAL(shift_index, WASM_I32V(shift)),
-          WASM_SET_LOCAL(simd1, WASM_SIMD_I32x4_SPLAT(WASM_GET_LOCAL(value))),
-          WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd1),
-                                                WASM_GET_LOCAL(shift_index))),
-          WASM_ONE);
+    byte simd = r.AllocateLocal(kWasmS128);
+    // Shift using an immediate, and shift using a value loaded from memory.
+    BUILD(
+        r, WASM_SET_LOCAL(simd, WASM_SIMD_I32x4_SPLAT(WASM_GET_LOCAL(value))),
+        WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd),
+                                              WASM_I32V(shift))),
+        WASM_SET_GLOBAL(1, WASM_SIMD_SHIFT_OP(
+                               opcode, WASM_GET_LOCAL(simd),
+                               WASM_LOAD_MEM(MachineType::Int32(), WASM_ZERO))),
+        WASM_ONE);
 
+    r.builder().WriteMemory(&memory[0], shift);
     FOR_INT32_INPUTS(x) {
       r.Call(x);
       int32_t expected = expected_op(x, shift);
       for (int i = 0; i < 4; i++) {
-        CHECK_EQ(expected, ReadLittleEndianValue<int32_t>(&g[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int32_t>(&g_imm[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int32_t>(&g_mem[i]));
       }
     }
   }
@@ -2080,6 +2164,10 @@ WASM_SIMD_TEST(I16x8Neg) {
                    base::NegateWithWraparound);
 }
 
+WASM_SIMD_TEST(I16x8Abs) {
+  RunI16x8UnOpTest(execution_tier, lower_simd, kExprI16x8Abs, Abs);
+}
+
 template <typename T = int16_t, typename OpType = T (*)(T, T)>
 void RunI16x8BinOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
                        WasmOpcode opcode, OpType expected_op) {
@@ -2202,7 +2290,7 @@ WASM_SIMD_TEST(I16x8LeU) {
                     UnsignedLessEqual);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(I16x8RoundingAverageU) {
+WASM_SIMD_TEST(I16x8RoundingAverageU) {
   RunI16x8BinOpTest<uint16_t>(execution_tier, lower_simd,
                               kExprI16x8RoundingAverageU,
                               base::RoundingAverageUnsigned);
@@ -2213,22 +2301,28 @@ void RunI16x8ShiftOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   // Intentionally shift by 16, should be no-op.
   for (int shift = 1; shift <= 16; shift++) {
     WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
-    int16_t* g = r.builder().AddGlobal<int16_t>(kWasmS128);
+    int32_t* memory = r.builder().AddMemoryElems<int32_t>(1);
+    int16_t* g_imm = r.builder().AddGlobal<int16_t>(kWasmS128);
+    int16_t* g_mem = r.builder().AddGlobal<int16_t>(kWasmS128);
     byte value = 0;
-    byte simd1 = r.AllocateLocal(kWasmS128);
-    byte shift_index = r.AllocateLocal(kWasmI32);
-    BUILD(r,
-          WASM_SET_LOCAL(simd1, WASM_SIMD_I16x8_SPLAT(WASM_GET_LOCAL(value))),
-          WASM_SET_LOCAL(shift_index, WASM_I32V(shift)),
-          WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd1),
-                                                WASM_GET_LOCAL(shift_index))),
-          WASM_ONE);
+    byte simd = r.AllocateLocal(kWasmS128);
+    // Shift using an immediate, and shift using a value loaded from memory.
+    BUILD(
+        r, WASM_SET_LOCAL(simd, WASM_SIMD_I16x8_SPLAT(WASM_GET_LOCAL(value))),
+        WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd),
+                                              WASM_I32V(shift))),
+        WASM_SET_GLOBAL(1, WASM_SIMD_SHIFT_OP(
+                               opcode, WASM_GET_LOCAL(simd),
+                               WASM_LOAD_MEM(MachineType::Int32(), WASM_ZERO))),
+        WASM_ONE);
 
+    r.builder().WriteMemory(&memory[0], shift);
     FOR_INT16_INPUTS(x) {
       r.Call(x);
       int16_t expected = expected_op(x, shift);
       for (int i = 0; i < 8; i++) {
-        CHECK_EQ(expected, ReadLittleEndianValue<int16_t>(&g[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int16_t>(&g_imm[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int16_t>(&g_mem[i]));
       }
     }
   }
@@ -2275,6 +2369,10 @@ WASM_SIMD_TEST(I8x16Neg) {
                    base::NegateWithWraparound);
 }
 
+WASM_SIMD_TEST(I8x16Abs) {
+  RunI8x16UnOpTest(execution_tier, lower_simd, kExprI8x16Abs, Abs);
+}
+
 // Tests both signed and unsigned conversion from I16x8 (packing).
 WASM_SIMD_TEST(I8x16ConvertI16x8) {
   WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
@@ -2426,7 +2524,7 @@ WASM_SIMD_TEST(I8x16Mul) {
                     base::MulWithWraparound);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(I8x16RoundingAverageU) {
+WASM_SIMD_TEST(I8x16RoundingAverageU) {
   RunI8x16BinOpTest<uint8_t>(execution_tier, lower_simd,
                              kExprI8x16RoundingAverageU,
                              base::RoundingAverageUnsigned);
@@ -2437,22 +2535,28 @@ void RunI8x16ShiftOpTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   // Intentionally shift by 8, should be no-op.
   for (int shift = 1; shift <= 8; shift++) {
     WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
-    int8_t* g = r.builder().AddGlobal<int8_t>(kWasmS128);
+    int32_t* memory = r.builder().AddMemoryElems<int32_t>(1);
+    int8_t* g_imm = r.builder().AddGlobal<int8_t>(kWasmS128);
+    int8_t* g_mem = r.builder().AddGlobal<int8_t>(kWasmS128);
     byte value = 0;
-    byte simd1 = r.AllocateLocal(kWasmS128);
-    byte shift_index = r.AllocateLocal(kWasmI32);
-    BUILD(r,
-          WASM_SET_LOCAL(simd1, WASM_SIMD_I8x16_SPLAT(WASM_GET_LOCAL(value))),
-          WASM_SET_LOCAL(shift_index, WASM_I32V(shift)),
-          WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd1),
-                                                WASM_GET_LOCAL(shift_index))),
-          WASM_ONE);
+    byte simd = r.AllocateLocal(kWasmS128);
+    // Shift using an immediate, and shift using a value loaded from memory.
+    BUILD(
+        r, WASM_SET_LOCAL(simd, WASM_SIMD_I8x16_SPLAT(WASM_GET_LOCAL(value))),
+        WASM_SET_GLOBAL(0, WASM_SIMD_SHIFT_OP(opcode, WASM_GET_LOCAL(simd),
+                                              WASM_I32V(shift))),
+        WASM_SET_GLOBAL(1, WASM_SIMD_SHIFT_OP(
+                               opcode, WASM_GET_LOCAL(simd),
+                               WASM_LOAD_MEM(MachineType::Int32(), WASM_ZERO))),
+        WASM_ONE);
 
+    r.builder().WriteMemory(&memory[0], shift);
     FOR_INT8_INPUTS(x) {
       r.Call(x);
       int8_t expected = expected_op(x, shift);
       for (int i = 0; i < 16; i++) {
-        CHECK_EQ(expected, ReadLittleEndianValue<int8_t>(&g[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int8_t>(&g_imm[i]));
+        CHECK_EQ(expected, ReadLittleEndianValue<int8_t>(&g_mem[i]));
       }
     }
   }
@@ -2585,18 +2689,21 @@ void RunBinaryLaneOpTest(
 }
 
 WASM_SIMD_TEST(I32x4AddHoriz) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   // Inputs are [0 1 2 3] and [4 5 6 7].
   RunBinaryLaneOpTest<int32_t>(execution_tier, lower_simd, kExprI32x4AddHoriz,
                                {{1, 5, 9, 13}});
 }
 
 WASM_SIMD_TEST(I16x8AddHoriz) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   // Inputs are [0 1 2 3 4 5 6 7] and [8 9 10 11 12 13 14 15].
   RunBinaryLaneOpTest<int16_t>(execution_tier, lower_simd, kExprI16x8AddHoriz,
                                {{1, 5, 9, 13, 17, 21, 25, 29}});
 }
 
 WASM_SIMD_TEST(F32x4AddHoriz) {
+  FLAG_SCOPE(wasm_simd_post_mvp);
   // Inputs are [0.0f 1.0f 2.0f 3.0f] and [4.0f 5.0f 6.0f 7.0f].
   RunBinaryLaneOpTest<float>(execution_tier, lower_simd, kExprF32x4AddHoriz,
                              {{1.0f, 5.0f, 9.0f, 13.0f}});
@@ -2932,6 +3039,7 @@ WASM_SIMD_COMPILED_TEST(S8x16MultiShuffleFuzz) {
 // test inputs. Test inputs with all true, all false, one true, and one false.
 #define WASM_SIMD_BOOL_REDUCTION_TEST(format, lanes, int_type)                 \
   WASM_SIMD_TEST(ReductionTest##lanes) {                                       \
+    FLAG_SCOPE(wasm_simd_post_mvp); \
     WasmRunner<int32_t> r(execution_tier, lower_simd);                         \
     if (lanes == 2 && lower_simd == kLowerSimd) return;                        \
     byte zero = r.AllocateLocal(kWasmS128);                                    \
@@ -3320,15 +3428,15 @@ void RunLoadSplatTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   }
 }
 
-WASM_SIMD_TEST_NO_LOWERING(S8x16LoadSplat) {
+WASM_SIMD_TEST(S8x16LoadSplat) {
   RunLoadSplatTest<int8_t>(execution_tier, lower_simd, kExprS8x16LoadSplat);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(S16x8LoadSplat) {
+WASM_SIMD_TEST(S16x8LoadSplat) {
   RunLoadSplatTest<int16_t>(execution_tier, lower_simd, kExprS16x8LoadSplat);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(S32x4LoadSplat) {
+WASM_SIMD_TEST(S32x4LoadSplat) {
   RunLoadSplatTest<int32_t>(execution_tier, lower_simd, kExprS32x4LoadSplat);
 }
 
@@ -3360,21 +3468,21 @@ void RunLoadExtendTest(ExecutionTier execution_tier, LowerSimd lower_simd,
   }
 }
 
-WASM_SIMD_TEST_NO_LOWERING(I16x8Load8x8U) {
+WASM_SIMD_TEST(I16x8Load8x8U) {
   RunLoadExtendTest<uint8_t, uint16_t>(execution_tier, lower_simd,
                                        kExprI16x8Load8x8U);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(I16x8Load8x8S) {
+WASM_SIMD_TEST(I16x8Load8x8S) {
   RunLoadExtendTest<int8_t, int16_t>(execution_tier, lower_simd,
                                      kExprI16x8Load8x8S);
 }
-WASM_SIMD_TEST_NO_LOWERING(I32x4Load16x4U) {
+WASM_SIMD_TEST(I32x4Load16x4U) {
   RunLoadExtendTest<uint16_t, uint32_t>(execution_tier, lower_simd,
                                         kExprI32x4Load16x4U);
 }
 
-WASM_SIMD_TEST_NO_LOWERING(I32x4Load16x4S) {
+WASM_SIMD_TEST(I32x4Load16x4S) {
   RunLoadExtendTest<int16_t, int32_t>(execution_tier, lower_simd,
                                       kExprI32x4Load16x4S);
 }
@@ -3390,9 +3498,10 @@ WASM_SIMD_TEST_NO_LOWERING(I64x2Load32x2S) {
 }
 
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM64 || \
-    V8_TARGET_ARCH_ARM
+    V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_S390X
 #define WASM_SIMD_ANYTRUE_TEST(format, lanes, max, param_type)                \
   WASM_SIMD_TEST(S##format##AnyTrue) {                                        \
+    FLAG_SCOPE(wasm_simd_post_mvp); \
     WasmRunner<int32_t, param_type> r(execution_tier, lower_simd);            \
     if (lanes == 2 && lower_simd == kLowerSimd) return;                       \
     byte simd = r.AllocateLocal(kWasmS128);                                   \
@@ -3413,6 +3522,7 @@ WASM_SIMD_ANYTRUE_TEST(8x16, 16, 0xff, int32_t)
 
 #define WASM_SIMD_ALLTRUE_TEST(format, lanes, max, param_type)                \
   WASM_SIMD_TEST(S##format##AllTrue) {                                        \
+    FLAG_SCOPE(wasm_simd_post_mvp); \
     WasmRunner<int32_t, param_type> r(execution_tier, lower_simd);            \
     if (lanes == 2 && lower_simd == kLowerSimd) return;                       \
     byte simd = r.AllocateLocal(kWasmS128);                                   \
@@ -3431,7 +3541,7 @@ WASM_SIMD_ALLTRUE_TEST(32x4, 4, 0xffffffff, int32_t)
 WASM_SIMD_ALLTRUE_TEST(16x8, 8, 0xffff, int32_t)
 WASM_SIMD_ALLTRUE_TEST(8x16, 16, 0xff, int32_t)
 #endif  // V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM64 ||
-        // V8_TARGET_ARCH_ARM
+        // V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_S390X
 
 WASM_SIMD_TEST(BitSelect) {
   WasmRunner<int32_t, int32_t> r(execution_tier, lower_simd);
@@ -3564,7 +3674,6 @@ WASM_EXTRACT_I16x8_TEST(S, UINT16) WASM_EXTRACT_I16x8_TEST(I, INT16)
 #undef WASM_EXTRACT_I8x16_TEST
 
 #undef WASM_SIMD_TEST
-#undef WASM_SIMD_TEST_WITH_LIFTOFF
 #undef WASM_SIMD_CHECK_LANE_S
 #undef WASM_SIMD_CHECK_LANE_U
 #undef TO_BYTE
diff --git a/deps/v8/test/cctest/wasm/test-run-wasm.cc b/deps/v8/test/cctest/wasm/test-run-wasm.cc
index b84322f190..1aebac3c76 100644
--- a/deps/v8/test/cctest/wasm/test-run-wasm.cc
+++ b/deps/v8/test/cctest/wasm/test-run-wasm.cc
@@ -1571,8 +1571,7 @@ WASM_EXEC_TEST(LoadMem_offset_oob) {
     r.builder().RandomizeMemory(1116 + static_cast<int>(m));
 
     constexpr byte offset = 8;
-    uint32_t boundary =
-        num_bytes - offset - ValueTypes::MemSize(machineTypes[m]);
+    uint32_t boundary = num_bytes - offset - machineTypes[m].MemSize();
 
     BUILD(r, WASM_LOAD_MEM_OFFSET(machineTypes[m], offset, WASM_GET_LOCAL(0)),
           WASM_DROP, WASM_ZERO);
@@ -1718,7 +1717,7 @@ WASM_EXEC_TEST(StoreMem_offset_oob) {
                                    WASM_LOAD_MEM(machineTypes[m], WASM_ZERO)),
           WASM_ZERO);
 
-    byte memsize = ValueTypes::MemSize(machineTypes[m]);
+    byte memsize = machineTypes[m].MemSize();
     uint32_t boundary = num_bytes - 8 - memsize;
     CHECK_EQ(0, r.Call(boundary));  // in bounds.
     CHECK_EQ(0, memcmp(&memory[0], &memory[8 + boundary], memsize));
@@ -2009,7 +2008,7 @@ static void TestBuildGraphForSimpleExpression(WasmOpcode opcode) {
   compiler::Graph graph(&zone);
   compiler::JSGraph jsgraph(isolate, &graph, &common, nullptr, nullptr,
                             &machine);
-  FunctionSig* sig = WasmOpcodes::Signature(opcode);
+  const FunctionSig* sig = WasmOpcodes::Signature(opcode);
 
   if (sig->parameter_count() == 1) {
     byte code[] = {WASM_NO_LOCALS, kExprLocalGet, 0, static_cast<byte>(opcode),
@@ -2643,9 +2642,9 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
     // Build the selector function.
     // =========================================================================
     FunctionSig::Builder b(&zone, 1, num_params);
-    b.AddReturn(ValueTypes::ValueTypeFor(result));
+    b.AddReturn(ValueType::For(result));
     for (int i = 0; i < num_params; ++i) {
-      b.AddParam(ValueTypes::ValueTypeFor(memtypes[i]));
+      b.AddParam(ValueType::For(memtypes[i]));
     }
     WasmFunctionCompiler& t = r.NewFunction(b.Build());
     BUILD(t, WASM_GET_LOCAL(which));
@@ -2665,7 +2664,7 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
     ADD_CODE(code, WASM_CALL_FUNCTION0(t.function_index()));
 
     // Store the result in a local.
-    byte local_index = r.AllocateLocal(ValueTypes::ValueTypeFor(result));
+    byte local_index = r.AllocateLocal(ValueType::For(result));
     ADD_CODE(code, kExprLocalSet, local_index);
 
     // Store the result in memory.
@@ -2682,7 +2681,7 @@ static void Run_WasmMixedCall_N(ExecutionTier execution_tier, int start) {
       r.builder().RandomizeMemory();
       CHECK_EQ(kExpected, r.Call());
 
-      int size = ValueTypes::MemSize(result);
+      int size = result.MemSize();
       for (int i = 0; i < size; ++i) {
         int base = (which + 1) * kElemSize;
         byte expected = r.builder().raw_mem_at<byte>(base + i);
@@ -2740,7 +2739,7 @@ WASM_EXEC_TEST(MultiReturnSub) {
 template <typename T>
 void RunMultiReturnSelect(ExecutionTier execution_tier, const T* inputs) {
   EXPERIMENTAL_FLAG_SCOPE(mv);
-  ValueType type = ValueTypes::ValueTypeFor(MachineTypeForC<T>());
+  ValueType type = ValueType::For(MachineTypeForC<T>());
   ValueType storage[] = {type, type, type, type, type, type};
   const size_t kNumReturns = 2;
   const size_t kNumParams = arraysize(storage) - kNumReturns;
@@ -3498,7 +3497,7 @@ void BinOpOnDifferentRegisters(
     for (int i = 0; i < num_locals; ++i) {
       ADD_CODE(
           init_locals_code,
-          WASM_SET_LOCAL(i, WASM_LOAD_MEM(ValueTypes::MachineTypeFor(type),
+          WASM_SET_LOCAL(i, WASM_LOAD_MEM(type.machine_type(),
                                           WASM_I32V_2(sizeof(ctype) * i))));
     }
     // {write_locals_code} is shared by all code generated in the loop below.
@@ -3506,7 +3505,7 @@ void BinOpOnDifferentRegisters(
     // Write locals back into memory, shifted by one element to the right.
     for (int i = 0; i < num_locals; ++i) {
       ADD_CODE(write_locals_code,
-               WASM_STORE_MEM(ValueTypes::MachineTypeFor(type),
+               WASM_STORE_MEM(type.machine_type(),
                               WASM_I32V_2(sizeof(ctype) * (i + 1)),
                               WASM_GET_LOCAL(i)));
     }
@@ -3521,7 +3520,7 @@ void BinOpOnDifferentRegisters(
         std::vector<byte> code(init_locals_code);
         ADD_CODE(code,
                  // Store the result of the binary operation at memory[0].
-                 WASM_STORE_MEM(ValueTypes::MachineTypeFor(type), WASM_ZERO,
+                 WASM_STORE_MEM(type.machine_type(), WASM_ZERO,
                                 WASM_BINOP(opcode, WASM_GET_LOCAL(lhs),
                                            WASM_GET_LOCAL(rhs))),
                  // Return 0.
@@ -3753,9 +3752,9 @@ TEST(Liftoff_tier_up) {
     memcpy(buffer.get(), sub_code->instructions().begin(), sub_size);
     desc.buffer = buffer.get();
     desc.instr_size = static_cast<int>(sub_size);
-    std::unique_ptr<WasmCode> new_code = native_module->AddCode(
-        add.function_index(), desc, 0, 0, {}, OwnedVector<byte>(),
-        WasmCode::kFunction, ExecutionTier::kTurbofan);
+    std::unique_ptr<WasmCode> new_code =
+        native_module->AddCode(add.function_index(), desc, 0, 0, {}, {},
+                               WasmCode::kFunction, ExecutionTier::kTurbofan);
     native_module->PublishCode(std::move(new_code));
 
     // Second run should now execute {sub}.
diff --git a/deps/v8/test/cctest/wasm/test-streaming-compilation.cc b/deps/v8/test/cctest/wasm/test-streaming-compilation.cc
index 08c0c1dd46..4d3f83daff 100644
--- a/deps/v8/test/cctest/wasm/test-streaming-compilation.cc
+++ b/deps/v8/test/cctest/wasm/test-streaming-compilation.cc
@@ -1215,6 +1215,39 @@ STREAM_TEST(TestCompileErrorFunctionName) {
   }
 }
 
+STREAM_TEST(TestSetModuleCodeSection) {
+  StreamTester tester;
+
+  uint8_t code[] = {
+      U32V_1(1),                  // functions count
+      U32V_1(4),                  // body size
+      U32V_1(0),                  // locals count
+      kExprLocalGet, 0, kExprEnd  // body
+  };
+
+  const uint8_t bytes[] = {
+      WASM_MODULE_HEADER,                   // module header
+      kTypeSectionCode,                     // section code
+      U32V_1(1 + SIZEOF_SIG_ENTRY_x_x),     // section size
+      U32V_1(1),                            // type count
+      SIG_ENTRY_x_x(kLocalI32, kLocalI32),  // signature entry
+      kFunctionSectionCode,                 // section code
+      U32V_1(1 + 1),                        // section size
+      U32V_1(1),                            // functions count
+      0,                                    // signature index
+      kCodeSectionCode,                     // section code
+      U32V_1(arraysize(code)),              // section size
+  };
+
+  tester.OnBytesReceived(bytes, arraysize(bytes));
+  tester.OnBytesReceived(code, arraysize(code));
+  tester.FinishStream();
+  tester.RunCompilerTasks();
+  CHECK_EQ(tester.native_module()->module()->code.offset(), arraysize(bytes));
+  CHECK_EQ(tester.native_module()->module()->code.length(), arraysize(code));
+  CHECK(tester.IsPromiseFulfilled());
+}
+
 #undef STREAM_TEST
 
 }  // namespace wasm
diff --git a/deps/v8/test/cctest/wasm/test-wasm-breakpoints.cc b/deps/v8/test/cctest/wasm/test-wasm-breakpoints.cc
index 79c4c8eaec..9f011ecf38 100644
--- a/deps/v8/test/cctest/wasm/test-wasm-breakpoints.cc
+++ b/deps/v8/test/cctest/wasm/test-wasm-breakpoints.cc
@@ -139,6 +139,7 @@ class BreakHandler : public debug::DebugDelegate {
 Handle<BreakPoint> SetBreakpoint(WasmRunnerBase* runner, int function_index,
                                  int byte_offset,
                                  int expected_set_byte_offset = -1) {
+  runner->TierDown();
   int func_offset =
       runner->builder().GetFunctionAt(function_index)->code.offset();
   int code_offset = func_offset + byte_offset;
@@ -190,17 +191,17 @@ struct WasmValWrapper {
 // Only needed in debug builds. Avoid unused warning otherwise.
 #ifdef DEBUG
 std::ostream& operator<<(std::ostream& out, const WasmValWrapper& wrapper) {
-  switch (wrapper.val.type()) {
-    case kWasmI32:
+  switch (wrapper.val.type().kind()) {
+    case ValueType::kI32:
       out << "i32: " << wrapper.val.to<int32_t>();
       break;
-    case kWasmI64:
+    case ValueType::kI64:
       out << "i64: " << wrapper.val.to<int64_t>();
       break;
-    case kWasmF32:
+    case ValueType::kF32:
       out << "f32: " << wrapper.val.to<float>();
       break;
-    case kWasmF64:
+    case ValueType::kF64:
       out << "f64: " << wrapper.val.to<double>();
       break;
     default:
diff --git a/deps/v8/test/cctest/wasm/test-wasm-debug-evaluate.cc b/deps/v8/test/cctest/wasm/test-wasm-debug-evaluate.cc
new file mode 100644
index 0000000000..5a7b2bc201
--- /dev/null
+++ b/deps/v8/test/cctest/wasm/test-wasm-debug-evaluate.cc
@@ -0,0 +1,315 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <initializer_list>
+
+#include "src/api/api-inl.h"
+#include "src/base/macros.h"
+#include "src/codegen/assembler-inl.h"
+#include "src/compiler/heap-refs.h"
+#include "src/debug/debug-evaluate.h"
+#include "src/debug/debug-interface.h"
+#include "src/diagnostics/disassembler.h"
+#include "src/execution/frames-inl.h"
+#include "src/execution/frames.h"
+#include "src/objects/js-objects.h"
+#include "src/objects/property-descriptor.h"
+#include "src/utils/utils.h"
+#include "src/utils/vector.h"
+#include "src/wasm/compilation-environment.h"
+#include "src/wasm/module-decoder.h"
+#include "src/wasm/value-type.h"
+#include "src/wasm/wasm-constants.h"
+#include "src/wasm/wasm-debug-evaluate.h"
+#include "src/wasm/wasm-debug.h"
+#include "src/wasm/wasm-interpreter.h"
+#include "src/wasm/wasm-module-builder.h"
+#include "src/wasm/wasm-module.h"
+#include "src/wasm/wasm-objects-inl.h"
+#include "src/wasm/wasm-opcodes.h"
+#include "src/wasm/wasm-tier.h"
+#include "test/cctest/cctest.h"
+#include "test/cctest/compiler/value-helper.h"
+#include "test/cctest/wasm/wasm-run-utils.h"
+#include "test/common/wasm/test-signatures.h"
+#include "test/common/wasm/wasm-macro-gen.h"
+
+namespace v8 {
+namespace internal {
+namespace wasm {
+
+namespace {
+template <typename... FunctionArgsT>
+class TestCode {
+ public:
+  TestCode(WasmRunnerBase* runner, std::initializer_list<byte> code)
+      : compiler_(&runner->NewFunction<FunctionArgsT...>()), code_(code) {
+    compiler_->Build(code.begin(), code.end());
+  }
+
+  Handle<BreakPoint> BreakOnReturn(WasmRunnerBase* runner) {
+    runner->TierDown();
+    uint32_t return_offset_in_function = FindReturn();
+
+    int function_index = compiler_->function_index();
+    int function_offset =
+        runner->builder().GetFunctionAt(function_index)->code.offset();
+    int return_offset_in_module = function_offset + return_offset_in_function;
+
+    Handle<WasmInstanceObject> instance = runner->builder().instance_object();
+    Handle<Script> script(instance->module_object().script(),
+                          runner->main_isolate());
+    static int break_index = 0;
+    Handle<BreakPoint> break_point =
+        runner->main_isolate()->factory()->NewBreakPoint(
+            break_index++, runner->main_isolate()->factory()->empty_string());
+    CHECK(WasmScript::SetBreakPoint(script, &return_offset_in_module,
+                                    break_point));
+    int set_breakpoint_offset = return_offset_in_module - function_offset;
+    // Also set breakpoint on the debug info of the instance directly, since
+    // the instance chain is not set up properly in tests.
+    Handle<WasmDebugInfo> debug_info =
+        WasmInstanceObject::GetOrCreateDebugInfo(instance);
+    WasmDebugInfo::SetBreakpoint(debug_info, function_index,
+                                 set_breakpoint_offset);
+
+    return break_point;
+  }
+
+  MaybeHandle<Object> Run(WasmRunnerBase* runner) {
+    Isolate* isolate = runner->main_isolate();
+    Handle<JSFunction> fun_wrapper =
+        runner->builder().WrapCode(compiler_->function_index());
+    Handle<Object> global(isolate->context().global_object(), isolate);
+    return Execution::Call(isolate, fun_wrapper, global, 0, nullptr);
+  }
+
+ private:
+  uint32_t FindReturn() const {
+    for (auto i = code_.begin(); i != code_.end();
+         i += OpcodeLength(&*i, &*code_.end())) {
+      if (*i == kExprReturn) {
+        return static_cast<uint32_t>(std::distance(code_.begin(), i));
+      }
+    }
+    UNREACHABLE();
+  }
+
+  WasmFunctionCompiler* compiler_;
+  std::vector<byte> code_;
+};
+
+class WasmEvaluatorBuilder {
+ public:
+  explicit WasmEvaluatorBuilder(ExecutionTier execution_tier,
+                                uint32_t min_memory = 1,
+                                uint32_t max_memory = 1)
+      : zone_(&allocator_, ZONE_NAME), builder_(&zone_) {
+    get_memory_function_index = AddImport<void, uint32_t, uint32_t, uint32_t>(
+        CStrVector("__getMemory"));
+    wasm_format_function =
+        builder_.AddFunction(WasmRunnerBase::CreateSig<uint32_t>(&zone_));
+    wasm_format_function->SetName(CStrVector("wasm_format"));
+    builder_.AddExport(CStrVector("wasm_format"), wasm_format_function);
+    builder_.SetMinMemorySize(min_memory);
+    builder_.SetMaxMemorySize(max_memory);
+  }
+
+  template <typename ReturnT, typename... ArgTs>
+  uint32_t AddImport(Vector<const char> name) {
+    return builder_.AddImport(
+        name, WasmRunnerBase::CreateSig<ReturnT, ArgTs...>(&zone_));
+  }
+
+  void push_back(std::initializer_list<byte> code) {
+    wasm_format_function->EmitCode(code.begin(),
+                                   static_cast<uint32_t>(code.size()));
+  }
+
+  void CallGetMemory(std::initializer_list<byte> args) {
+    push_back(args);
+    push_back({WASM_CALL_FUNCTION0(wasm_format_function->func_index())});
+  }
+
+  ZoneBuffer bytes() {
+    ZoneBuffer bytes(&zone_);
+    builder_.WriteTo(&bytes);
+    return bytes;
+  }
+
+ private:
+  v8::internal::AccountingAllocator allocator_;
+  Zone zone_;
+  WasmModuleBuilder builder_;
+  uint32_t get_memory_function_index = 0;
+  WasmFunctionBuilder* wasm_format_function = nullptr;
+};
+
+class WasmBreakHandler : public debug::DebugDelegate {
+ public:
+  struct EvaluationResult {
+    Maybe<std::string> result = Nothing<std::string>();
+    Maybe<std::string> error = Nothing<std::string>();
+  };
+
+  WasmBreakHandler(Isolate* isolate, ZoneBuffer evaluator_bytes)
+      : isolate_(isolate),
+        evaluator_bytes_(std::move(evaluator_bytes)),
+        result_(Nothing<EvaluationResult>()) {
+    v8::debug::SetDebugDelegate(reinterpret_cast<v8::Isolate*>(isolate_), this);
+  }
+
+  ~WasmBreakHandler() override {
+    v8::debug::SetDebugDelegate(reinterpret_cast<v8::Isolate*>(isolate_),
+                                nullptr);
+  }
+
+  const Maybe<EvaluationResult>& result() const { return result_; }
+
+ private:
+  Isolate* isolate_;
+  ZoneBuffer evaluator_bytes_;
+  Maybe<EvaluationResult> result_;
+
+  Maybe<std::string> GetPendingExceptionAsString() {
+    if (!isolate_->has_pending_exception()) return Nothing<std::string>();
+    Handle<Object> exception(isolate_->pending_exception(), isolate_);
+    isolate_->clear_pending_exception();
+
+    Handle<String> exception_string;
+    if (!Object::ToString(isolate_, exception).ToHandle(&exception_string)) {
+      return Just<std::string>("");
+    }
+    return Just<std::string>(exception_string->ToCString().get());
+  }
+
+  void BreakProgramRequested(v8::Local<v8::Context> paused_context,
+                             const std::vector<int>&) override {
+    // Check the current position.
+    StackTraceFrameIterator frame_it(isolate_);
+
+    FrameSummary::WasmInterpretedFrameSummary summary =
+        FrameSummary::GetTop(frame_it.frame()).AsWasmInterpreted();
+    Handle<WasmInstanceObject> instance = summary.wasm_instance();
+    WasmInterpreter::FramePtr frame =
+        instance->debug_info().GetInterpretedFrame(frame_it.frame()->fp(), 0);
+
+    MaybeHandle<String> result_handle = v8::internal::wasm::DebugEvaluate(
+        {evaluator_bytes_.begin(), evaluator_bytes_.size()}, instance,
+        std::move(frame));
+
+    Maybe<std::string> error_message = GetPendingExceptionAsString();
+    Maybe<std::string> result_message =
+        result_handle.is_null()
+            ? Nothing<std::string>()
+            : Just<std::string>(
+                  result_handle.ToHandleChecked()->ToCString().get());
+
+    isolate_->clear_pending_exception();
+    result_ = Just<EvaluationResult>({result_message, error_message});
+  }
+};
+
+WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_CompileFailed) {
+  WasmRunner<int> runner(execution_tier);
+
+  TestCode<int> code(&runner, {WASM_RETURN1(WASM_I32V_1(32))});
+  code.BreakOnReturn(&runner);
+
+  WasmEvaluatorBuilder evaluator(execution_tier);
+  // Create a module that doesn't compile by missing the END bytecode
+  evaluator.push_back({WASM_RETURN1(WASM_I32V_1(33))});
+
+  Isolate* isolate = runner.main_isolate();
+  WasmBreakHandler break_handler(isolate, evaluator.bytes());
+  CHECK(!code.Run(&runner).is_null());
+
+  WasmBreakHandler::EvaluationResult result =
+      break_handler.result().ToChecked();
+  CHECK(result.result.IsNothing());
+  CHECK_NE(result.error.ToChecked().find(
+               "function body must end with \"end\" opcode"),
+           std::string::npos);
+}
+
+WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_MissingEntrypoint) {
+  WasmRunner<int> runner(execution_tier);
+
+  TestCode<int> code(&runner, {WASM_RETURN1(WASM_I32V_1(32))});
+  code.BreakOnReturn(&runner);
+
+  v8::internal::AccountingAllocator allocator;
+  Zone zone(&allocator, ZONE_NAME);
+  WasmModuleBuilder evaluator(&zone);
+  ZoneBuffer evaluator_bytes(&zone);
+  evaluator.WriteTo(&evaluator_bytes);
+
+  Isolate* isolate = runner.main_isolate();
+  WasmBreakHandler break_handler(isolate, std::move(evaluator_bytes));
+  CHECK(!code.Run(&runner).is_null());
+
+  WasmBreakHandler::EvaluationResult result =
+      break_handler.result().ToChecked();
+  CHECK(result.result.IsNothing());
+  CHECK_NE(result.error.ToChecked().find("Missing export: \"wasm_format\""),
+           std::string::npos);
+}
+
+WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_ExecuteFailed_SEGV) {
+  WasmRunner<int> runner(execution_tier);
+  runner.builder().AddMemoryElems<int32_t>(64);
+
+  TestCode<int> code(&runner, {WASM_RETURN1(WASM_I32V_1(32))});
+
+  // Create a module that doesn't compile by missing the END bytecode
+  WasmEvaluatorBuilder evaluator(execution_tier);
+  code.BreakOnReturn(&runner);
+
+  // Load 1 byte from an address that's too high
+  evaluator.CallGetMemory(
+      {WASM_I32V_1(32), WASM_I32V_1(1), WASM_I32V_3((1 << 16) + 1)});
+  evaluator.push_back({WASM_RETURN1(WASM_I32V_1(33)), WASM_END});
+
+  Isolate* isolate = runner.main_isolate();
+  WasmBreakHandler break_handler(isolate, evaluator.bytes());
+  CHECK(!code.Run(&runner).is_null());
+
+  WasmBreakHandler::EvaluationResult result =
+      break_handler.result().ToChecked();
+  CHECK(result.result.IsNothing());
+  CHECK_NE(
+      result.error.ToChecked().find("Illegal access to out-of-bounds memory"),
+      std::string::npos);
+}
+
+WASM_COMPILED_EXEC_TEST(WasmDebugEvaluate_LinearMemory) {
+  WasmRunner<int> runner(execution_tier);
+  runner.builder().AddMemoryElems<int32_t>(64);
+
+  TestCode<int> code(
+      &runner,
+      {WASM_STORE_MEM(MachineType::Int32(), WASM_I32V_1(32), WASM_I32V_2('A')),
+       WASM_RETURN1(WASM_LOAD_MEM(MachineType::Int32(), WASM_I32V_1(32)))});
+  code.BreakOnReturn(&runner);
+
+  WasmEvaluatorBuilder evaluator(execution_tier);
+  // Load 4 bytes from debuggee memory at address 32, and store at the offset 33
+  // of the linear memory.
+  evaluator.CallGetMemory({WASM_I32V_1(32), WASM_I32V_1(4), WASM_I32V_1(33)});
+  evaluator.push_back({WASM_RETURN1(WASM_I32V_1(33)), WASM_END});
+
+  Isolate* isolate = runner.main_isolate();
+  WasmBreakHandler break_handler(isolate, evaluator.bytes());
+  CHECK(!code.Run(&runner).is_null());
+
+  WasmBreakHandler::EvaluationResult result =
+      break_handler.result().ToChecked();
+  CHECK(result.error.IsNothing());
+  CHECK_EQ(result.result.ToChecked(), "A");
+}
+
+}  // namespace
+}  // namespace wasm
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/test/cctest/wasm/test-wasm-stack.cc b/deps/v8/test/cctest/wasm/test-wasm-stack.cc
index 1ee1b3dfc6..864b8885a2 100644
--- a/deps/v8/test/cctest/wasm/test-wasm-stack.cc
+++ b/deps/v8/test/cctest/wasm/test-wasm-stack.cc
@@ -4,6 +4,7 @@
 
 #include "src/api/api-inl.h"
 #include "src/codegen/assembler-inl.h"
+#include "src/objects/stack-frame-info-inl.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/compiler/value-helper.h"
 #include "test/cctest/wasm/wasm-run-utils.h"
@@ -151,6 +152,63 @@ WASM_EXEC_TEST(CollectDetailedWasmStack_ExplicitThrowFromJs) {
                       expected_exceptions);
 }
 
+// Trigger a trap in wasm, stack should contain a source url.
+WASM_EXEC_TEST(CollectDetailedWasmStack_WasmUrl) {
+  // Create a WasmRunner with stack checks and traps enabled.
+  WasmRunner<int> r(execution_tier, nullptr, "main", kRuntimeExceptionSupport);
+
+  std::vector<byte> code(1, kExprUnreachable);
+  r.Build(code.data(), code.data() + code.size());
+
+  WasmFunctionCompiler& f = r.NewFunction<int>("call_main");
+  BUILD(f, WASM_CALL_FUNCTION0(0));
+  uint32_t wasm_index = f.function_index();
+
+  Handle<JSFunction> js_wasm_wrapper = r.builder().WrapCode(wasm_index);
+
+  Handle<JSFunction> js_trampoline = Handle<JSFunction>::cast(
+      v8::Utils::OpenHandle(*v8::Local<v8::Function>::Cast(
+          CompileRun("(function callFn(fn) { fn(); })"))));
+
+  Isolate* isolate = js_wasm_wrapper->GetIsolate();
+  isolate->SetCaptureStackTraceForUncaughtExceptions(true, 10,
+                                                     v8::StackTrace::kOverview);
+
+  // Set the wasm script source url.
+  const char* url = "http://example.com/example.wasm";
+  const Handle<String> source_url =
+      isolate->factory()->InternalizeUtf8String(url);
+  r.builder().instance_object()->module_object().script().set_source_url(
+      *source_url);
+
+  // Run the js wrapper.
+  Handle<Object> global(isolate->context().global_object(), isolate);
+  MaybeHandle<Object> maybe_exc;
+  Handle<Object> args[] = {js_wasm_wrapper};
+  MaybeHandle<Object> maybe_return_obj =
+      Execution::TryCall(isolate, js_trampoline, global, 1, args,
+                         Execution::MessageHandling::kReport, &maybe_exc);
+
+  CHECK(maybe_return_obj.is_null());
+  Handle<Object> exception = maybe_exc.ToHandleChecked();
+
+  // Extract stack trace from the exception.
+  Handle<FixedArray> stack_trace_object =
+      isolate->GetDetailedStackTrace(Handle<JSObject>::cast(exception));
+  CHECK(!stack_trace_object.is_null());
+  Handle<StackTraceFrame> stack_frame = Handle<StackTraceFrame>::cast(
+      handle(stack_trace_object->get(0), isolate));
+
+  MaybeHandle<String> maybe_stack_trace_str =
+      SerializeStackTraceFrame(isolate, stack_frame);
+  CHECK(!maybe_stack_trace_str.is_null());
+  Handle<String> stack_trace_str = maybe_stack_trace_str.ToHandleChecked();
+
+  // Check if the source_url is part of the stack trace.
+  CHECK_NE(std::string(stack_trace_str->ToCString().get()).find(url),
+           std::string::npos);
+}
+
 // Trigger a trap in wasm, stack should be JS -> wasm -> wasm.
 WASM_EXEC_TEST(CollectDetailedWasmStack_WasmError) {
   for (int pos_shift = 0; pos_shift < 3; ++pos_shift) {
diff --git a/deps/v8/test/cctest/wasm/wasm-run-utils.cc b/deps/v8/test/cctest/wasm/wasm-run-utils.cc
index e2e6458da8..96980e6df7 100644
--- a/deps/v8/test/cctest/wasm/wasm-run-utils.cc
+++ b/deps/v8/test/cctest/wasm/wasm-run-utils.cc
@@ -8,14 +8,45 @@
 #include "src/diagnostics/code-tracer.h"
 #include "src/heap/heap-inl.h"
 #include "src/wasm/graph-builder-interface.h"
+#include "src/wasm/leb-helper.h"
 #include "src/wasm/module-compiler.h"
 #include "src/wasm/wasm-import-wrapper-cache.h"
 #include "src/wasm/wasm-objects-inl.h"
+#include "src/wasm/wasm-opcodes.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
+template <>
+void AppendSingle(std::vector<byte>* code, WasmOpcode op) {
+  // We do not yet have opcodes that take up more than 2 byte (decoded). But if
+  // that changes, this will need to be updated.
+  DCHECK_EQ(0, op >> 16);
+  byte prefix = (op >> 8) & 0xff;
+  byte opcode = op & 0xff;
+
+  if (!prefix) {
+    code->push_back(opcode);
+    return;
+  }
+
+  // Ensure the prefix is really one of the supported prefixed opcodes.
+  DCHECK(WasmOpcodes::IsPrefixOpcode(static_cast<WasmOpcode>(prefix)));
+  code->push_back(prefix);
+
+  // Decoded opcodes fit in a byte (0x00-0xff).
+  DCHECK_LE(LEBHelper::sizeof_u32v(opcode), 2);
+  // Therefore, the encoding needs max 2 bytes.
+  uint8_t encoded[2];
+  uint8_t* d = encoded;
+  // d is updated to after the last uint8_t written.
+  LEBHelper::write_u32v(&d, opcode);
+  for (uint8_t* p = encoded; p < d; p++) {
+    code->push_back(*p);
+  }
+}
+
 TestingModuleBuilder::TestingModuleBuilder(
     Zone* zone, ManuallyImportedJSFunction* maybe_import, ExecutionTier tier,
     RuntimeExceptionSupport exception_support, LowerSimd lower_simd)
@@ -69,6 +100,12 @@ TestingModuleBuilder::TestingModuleBuilder(
   }
 }
 
+TestingModuleBuilder::~TestingModuleBuilder() {
+  // When the native module dies and is erased from the cache, it is expected to
+  // have either valid bytes or no bytes at all.
+  native_module_->SetWireBytes({});
+}
+
 byte* TestingModuleBuilder::AddMemory(uint32_t size, SharedFlag shared) {
   CHECK(!test_module_->has_memory);
   CHECK_NULL(mem_start_);
@@ -99,7 +136,8 @@ byte* TestingModuleBuilder::AddMemory(uint32_t size, SharedFlag shared) {
   return mem_start_;
 }
 
-uint32_t TestingModuleBuilder::AddFunction(FunctionSig* sig, const char* name,
+uint32_t TestingModuleBuilder::AddFunction(const FunctionSig* sig,
+                                           const char* name,
                                            FunctionType type) {
   if (test_module_->functions.size() == 0) {
     // TODO(titzer): Reserving space here to avoid the underlying WasmFunction
@@ -107,7 +145,13 @@ uint32_t TestingModuleBuilder::AddFunction(FunctionSig* sig, const char* name,
     test_module_->functions.reserve(kMaxFunctions);
   }
   uint32_t index = static_cast<uint32_t>(test_module_->functions.size());
-  test_module_->functions.push_back({sig, index, 0, {0, 0}, false, false});
+  test_module_->functions.push_back({sig,      // sig
+                                     index,    // func_index
+                                     0,        // sig_index
+                                     {0, 0},   // code
+                                     false,    // imported
+                                     false,    // exported
+                                     false});  // declared
   if (type == kImport) {
     DCHECK_EQ(0, test_module_->num_declared_functions);
     ++test_module_->num_imported_functions;
@@ -131,8 +175,9 @@ uint32_t TestingModuleBuilder::AddFunction(FunctionSig* sig, const char* name,
         sig);
     std::unique_ptr<wasm::WasmCode> code = native_module_->AddCode(
         index, result.code_desc, result.frame_slot_count,
-        result.tagged_parameter_slots, std::move(result.protected_instructions),
-        std::move(result.source_positions), wasm::WasmCode::kInterpreterEntry,
+        result.tagged_parameter_slots,
+        result.protected_instructions_data.as_vector(),
+        result.source_positions.as_vector(), wasm::WasmCode::kInterpreterEntry,
         wasm::ExecutionTier::kInterpreter);
     native_module_->PublishCode(std::move(code));
   }
@@ -228,7 +273,7 @@ uint32_t TestingModuleBuilder::AddBytes(Vector<const byte> bytes) {
   return bytes_offset;
 }
 
-uint32_t TestingModuleBuilder::AddException(FunctionSig* sig) {
+uint32_t TestingModuleBuilder::AddException(const FunctionSig* sig) {
   DCHECK_EQ(0, sig->return_count());
   uint32_t index = static_cast<uint32_t>(test_module_->exceptions.size());
   test_module_->exceptions.push_back(WasmException{sig});
@@ -283,7 +328,7 @@ uint32_t TestingModuleBuilder::AddPassiveElementSegment(
   uint32_t index = static_cast<uint32_t>(test_module_->elem_segments.size());
   DCHECK_EQ(index, dropped_elem_segments_.size());
 
-  test_module_->elem_segments.emplace_back();
+  test_module_->elem_segments.emplace_back(false);
   auto& elem_segment = test_module_->elem_segments.back();
   elem_segment.entries = entries;
 
@@ -293,18 +338,22 @@ uint32_t TestingModuleBuilder::AddPassiveElementSegment(
   return index;
 }
 
-CompilationEnv TestingModuleBuilder::CreateCompilationEnv() {
+CompilationEnv TestingModuleBuilder::CreateCompilationEnv(
+    AssumeDebugging debug) {
   // This is a hack so we don't need to call
   // trap_handler::IsTrapHandlerEnabled().
   const bool is_trap_handler_enabled =
       V8_TRAP_HANDLER_SUPPORTED && i::FLAG_wasm_trap_handler;
   return {test_module_ptr_,
           is_trap_handler_enabled ? kUseTrapHandler : kNoTrapHandler,
-          runtime_exception_support_, enabled_features_, lower_simd()};
+          runtime_exception_support_,
+          enabled_features_,
+          lower_simd(),
+          debug};
 }
 
 const WasmGlobal* TestingModuleBuilder::AddGlobal(ValueType type) {
-  byte size = ValueTypes::MemSize(ValueTypes::MachineTypeFor(type));
+  byte size = type.element_size_bytes();
   global_offset = (global_offset + size - 1) & ~(size - 1);  // align
   test_module_->globals.push_back(
       {type, true, WasmInitExpr(), {global_offset}, false, false});
@@ -342,7 +391,7 @@ Handle<WasmInstanceObject> TestingModuleBuilder::InitInstanceObject() {
 }
 
 void TestBuildingGraphWithBuilder(compiler::WasmGraphBuilder* builder,
-                                  Zone* zone, FunctionSig* sig,
+                                  Zone* zone, const FunctionSig* sig,
                                   const byte* start, const byte* end) {
   WasmFeatures unused_detected_features;
   FunctionBody body(sig, 0, start, end);
@@ -369,7 +418,7 @@ void TestBuildingGraphWithBuilder(compiler::WasmGraphBuilder* builder,
 }
 
 void TestBuildingGraph(Zone* zone, compiler::JSGraph* jsgraph,
-                       CompilationEnv* module, FunctionSig* sig,
+                       CompilationEnv* module, const FunctionSig* sig,
                        compiler::SourcePositionTable* source_position_table,
                        const byte* start, const byte* end) {
   compiler::WasmGraphBuilder builder(module, zone, jsgraph, sig,
@@ -542,7 +591,7 @@ void WasmFunctionCompiler::Build(const byte* start, const byte* end) {
   if (WasmCode::ShouldBeLogged(isolate())) code->LogCode(isolate());
 }
 
-WasmFunctionCompiler::WasmFunctionCompiler(Zone* zone, FunctionSig* sig,
+WasmFunctionCompiler::WasmFunctionCompiler(Zone* zone, const FunctionSig* sig,
                                            TestingModuleBuilder* builder,
                                            const char* name)
     : GraphAndBuilders(zone),
@@ -561,23 +610,24 @@ WasmFunctionCompiler::WasmFunctionCompiler(Zone* zone, FunctionSig* sig,
 
 WasmFunctionCompiler::~WasmFunctionCompiler() = default;
 
-FunctionSig* WasmRunnerBase::CreateSig(MachineType return_type,
+/* static */
+FunctionSig* WasmRunnerBase::CreateSig(Zone* zone, MachineType return_type,
                                        Vector<MachineType> param_types) {
   int return_count = return_type.IsNone() ? 0 : 1;
   int param_count = param_types.length();
 
   // Allocate storage array in zone.
-  ValueType* sig_types = zone_.NewArray<ValueType>(return_count + param_count);
+  ValueType* sig_types = zone->NewArray<ValueType>(return_count + param_count);
 
   // Convert machine types to local types, and check that there are no
   // MachineType::None()'s in the parameters.
   int idx = 0;
-  if (return_count) sig_types[idx++] = ValueTypes::ValueTypeFor(return_type);
+  if (return_count) sig_types[idx++] = ValueType::For(return_type);
   for (MachineType param : param_types) {
     CHECK_NE(MachineType::None(), param);
-    sig_types[idx++] = ValueTypes::ValueTypeFor(param);
+    sig_types[idx++] = ValueType::For(param);
   }
-  return new (&zone_) FunctionSig(return_count, param_count, sig_types);
+  return new (zone) FunctionSig(return_count, param_count, sig_types);
 }
 
 // static
diff --git a/deps/v8/test/cctest/wasm/wasm-run-utils.h b/deps/v8/test/cctest/wasm/wasm-run-utils.h
index b66f6ffa36..d1bc9293b6 100644
--- a/deps/v8/test/cctest/wasm/wasm-run-utils.h
+++ b/deps/v8/test/cctest/wasm/wasm-run-utils.h
@@ -75,9 +75,45 @@ using compiler::Node;
     r.Build(code, code + arraysize(code)); \
   } while (false)
 
+template <typename T>
+void AppendSingle(std::vector<byte>* code, T t) {
+  static_assert(std::is_integral<T>::value,
+                "Special types need specializations");
+  code->push_back(t);
+}
+
+// Specialized for WasmOpcode.
+template <>
+void AppendSingle<WasmOpcode>(std::vector<byte>* code, WasmOpcode op);
+
+template <typename... T>
+void Append(std::vector<byte>* code, T... ts) {
+  static_assert(sizeof...(ts) == 0, "Base case for appending bytes to code.");
+}
+
+template <typename First, typename... Rest>
+void Append(std::vector<byte>* code, First first, Rest... rest) {
+  AppendSingle(code, first);
+  Append(code, rest...);
+}
+
+// Like BUILD but pushes code bytes into a std::vector instead of an array
+// initializer. This is useful for opcodes (like SIMD), that are LEB128
+// (variable-sized). We use recursive template instantiations with variadic
+// template arguments, so that the Append calls can handle either bytes or
+// opcodes. AppendSingle is specialized for WasmOpcode, and appends multiple
+// bytes. This allows existing callers to swap out the BUILD macro for BUILD_V
+// macro without changes. Also see https://crbug.com/v8/10258.
+#define BUILD_V(r, ...)                              \
+  do {                                               \
+    std::vector<byte> code;                          \
+    Append(&code, __VA_ARGS__);                      \
+    r.Build(code.data(), code.data() + code.size()); \
+  } while (false)
+
 // For tests that must manually import a JSFunction with source code.
 struct ManuallyImportedJSFunction {
-  FunctionSig* sig;
+  const FunctionSig* sig;
   Handle<JSFunction> js_function;
 };
 
@@ -89,6 +125,7 @@ class TestingModuleBuilder {
  public:
   TestingModuleBuilder(Zone*, ManuallyImportedJSFunction*, ExecutionTier,
                        RuntimeExceptionSupport, LowerSimd);
+  ~TestingModuleBuilder();
 
   void ChangeOriginToAsmjs() { test_module_->origin = kAsmJsSloppyOrigin; }
 
@@ -103,13 +140,12 @@ class TestingModuleBuilder {
   }
 
   template <typename T>
-  T* AddGlobal(
-      ValueType type = ValueTypes::ValueTypeFor(MachineTypeForC<T>())) {
+  T* AddGlobal(ValueType type = ValueType::For(MachineTypeForC<T>())) {
     const WasmGlobal* global = AddGlobal(type);
     return reinterpret_cast<T*>(globals_data_ + global->offset);
   }
 
-  byte AddSignature(FunctionSig* sig) {
+  byte AddSignature(const FunctionSig* sig) {
     DCHECK_EQ(test_module_->signatures.size(),
               test_module_->signature_ids.size());
     test_module_->signatures.push_back(sig);
@@ -180,7 +216,8 @@ class TestingModuleBuilder {
   void SetHasSharedMemory() { test_module_->has_shared_memory = true; }
 
   enum FunctionType { kImport, kWasm };
-  uint32_t AddFunction(FunctionSig* sig, const char* name, FunctionType type);
+  uint32_t AddFunction(const FunctionSig* sig, const char* name,
+                       FunctionType type);
 
   // Freezes the signature map of the module and allocates the storage for
   // export wrappers.
@@ -196,7 +233,7 @@ class TestingModuleBuilder {
 
   uint32_t AddBytes(Vector<const byte> bytes);
 
-  uint32_t AddException(FunctionSig* sig);
+  uint32_t AddException(const FunctionSig* sig);
 
   uint32_t AddPassiveDataSegment(Vector<const byte> bytes);
   uint32_t AddPassiveElementSegment(const std::vector<uint32_t>& entries);
@@ -221,7 +258,10 @@ class TestingModuleBuilder {
 
   void SetExecutable() { native_module_->SetExecutable(true); }
 
-  CompilationEnv CreateCompilationEnv();
+  void TierDown() { native_module_->TierDown(isolate_); }
+
+  enum AssumeDebugging : bool { kDebug = true, kNoDebug = false };
+  CompilationEnv CreateCompilationEnv(AssumeDebugging = kNoDebug);
 
   ExecutionTier execution_tier() const { return execution_tier_; }
 
@@ -257,7 +297,7 @@ class TestingModuleBuilder {
 };
 
 void TestBuildingGraph(Zone* zone, compiler::JSGraph* jsgraph,
-                       CompilationEnv* module, FunctionSig* sig,
+                       CompilationEnv* module, const FunctionSig* sig,
                        compiler::SourcePositionTable* source_position_table,
                        const byte* start, const byte* end);
 
@@ -336,11 +376,11 @@ class WasmFunctionCompiler : public compiler::GraphAndBuilders {
  private:
   friend class WasmRunnerBase;
 
-  WasmFunctionCompiler(Zone* zone, FunctionSig* sig,
+  WasmFunctionCompiler(Zone* zone, const FunctionSig* sig,
                        TestingModuleBuilder* builder, const char* name);
 
   compiler::JSGraph jsgraph;
-  FunctionSig* sig;
+  const FunctionSig* sig;
   // The call descriptor is initialized when the function is compiled.
   CallDescriptor* descriptor_;
   TestingModuleBuilder* builder_;
@@ -382,7 +422,7 @@ class WasmRunnerBase : public HandleAndZoneScope {
   // Resets the state for building the next function.
   // The main function called will be the last generated function.
   // Returns the index of the previously built function.
-  WasmFunctionCompiler& NewFunction(FunctionSig* sig,
+  WasmFunctionCompiler& NewFunction(const FunctionSig* sig,
                                     const char* name = nullptr) {
     functions_.emplace_back(
         new WasmFunctionCompiler(&zone_, sig, &builder_, name));
@@ -406,18 +446,25 @@ class WasmRunnerBase : public HandleAndZoneScope {
 
   bool interpret() { return builder_.interpret(); }
 
+  void TierDown() { builder_.TierDown(); }
+
   template <typename ReturnType, typename... ParamTypes>
   FunctionSig* CreateSig() {
+    return WasmRunnerBase::CreateSig<ReturnType, ParamTypes...>(&zone_);
+  }
+
+  template <typename ReturnType, typename... ParamTypes>
+  static FunctionSig* CreateSig(Zone* zone) {
     std::array<MachineType, sizeof...(ParamTypes)> param_machine_types{
         {MachineTypeForC<ParamTypes>()...}};
     Vector<MachineType> param_vec(param_machine_types.data(),
                                   param_machine_types.size());
-    return CreateSig(MachineTypeForC<ReturnType>(), param_vec);
+    return CreateSig(zone, MachineTypeForC<ReturnType>(), param_vec);
   }
 
  private:
-  FunctionSig* CreateSig(MachineType return_type,
-                         Vector<MachineType> param_types);
+  static FunctionSig* CreateSig(Zone* zone, MachineType return_type,
+                                Vector<MachineType> param_types);
 
  protected:
   v8::internal::AccountingAllocator allocator_;
@@ -559,6 +606,10 @@ class WasmRunner : public WasmRunnerBase {
     CheckCallApplyViaJS(expected, function()->func_index, buffer, sizeof...(p));
   }
 
+  void CheckCallViaJSTraps(ParamTypes... p) {
+    CheckCallViaJS(static_cast<double>(0xDEADBEEF), p...);
+  }
+
   void CheckUsedExecutionTier(ExecutionTier expected_tier) {
     // Liftoff can fail and fallback to Turbofan, so check that the function
     // gets compiled by the tier requested, to guard against accidental success.
diff --git a/deps/v8/test/common/types-fuzz.h b/deps/v8/test/common/types-fuzz.h
index 21a7b7cafc..eacedd376a 100644
--- a/deps/v8/test/common/types-fuzz.h
+++ b/deps/v8/test/common/types-fuzz.h
@@ -53,29 +53,34 @@ class Types {
     SignedSmall = Type::SignedSmall();
     UnsignedSmall = Type::UnsignedSmall();
 
-    object_map =
+    Handle<i::Map> object_map =
         isolate->factory()->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
-
-    smi = handle(Smi::FromInt(666), isolate);
-    boxed_smi = isolate->factory()->NewHeapNumber(666);
-    signed32 = isolate->factory()->NewHeapNumber(0x40000000);
-    float1 = isolate->factory()->NewHeapNumber(1.53);
-    float2 = isolate->factory()->NewHeapNumber(0.53);
+    Handle<i::Smi> smi = handle(Smi::FromInt(666), isolate);
+    Handle<i::HeapNumber> boxed_smi = isolate->factory()->NewHeapNumber(666);
+    Handle<i::HeapNumber> signed32 =
+        isolate->factory()->NewHeapNumber(0x40000000);
+    Handle<i::HeapNumber> float1 = isolate->factory()->NewHeapNumber(1.53);
+    Handle<i::HeapNumber> float2 = isolate->factory()->NewHeapNumber(0.53);
     // float3 is identical to float1 in order to test that OtherNumberConstant
     // types are equal by double value and not by handle pointer value.
-    float3 = isolate->factory()->NewHeapNumber(1.53);
-    object1 = isolate->factory()->NewJSObjectFromMap(object_map);
-    object2 = isolate->factory()->NewJSObjectFromMap(object_map);
-    array = isolate->factory()->NewJSArray(20);
-    uninitialized = isolate->factory()->uninitialized_value();
-    SmiConstant = Type::NewConstant(js_heap_broker(), smi, zone);
-    Signed32Constant = Type::NewConstant(js_heap_broker(), signed32, zone);
-
-    ObjectConstant1 = Type::HeapConstant(js_heap_broker(), object1, zone);
-    ObjectConstant2 = Type::HeapConstant(js_heap_broker(), object2, zone);
-    ArrayConstant = Type::HeapConstant(js_heap_broker(), array, zone);
+    Handle<i::HeapNumber> float3 = isolate->factory()->NewHeapNumber(1.53);
+    Handle<i::JSObject> object1 =
+        isolate->factory()->NewJSObjectFromMap(object_map);
+    Handle<i::JSObject> object2 =
+        isolate->factory()->NewJSObjectFromMap(object_map);
+    Handle<i::JSArray> array = isolate->factory()->NewJSArray(20);
+    Handle<i::Oddball> uninitialized =
+        isolate->factory()->uninitialized_value();
+    Handle<i::Oddball> undefined = isolate->factory()->undefined_value();
+    Handle<i::HeapNumber> nan = isolate->factory()->nan_value();
+
+    SmiConstant = Type::Constant(js_heap_broker(), smi, zone);
+    Signed32Constant = Type::Constant(js_heap_broker(), signed32, zone);
+    ObjectConstant1 = Type::Constant(js_heap_broker(), object1, zone);
+    ObjectConstant2 = Type::Constant(js_heap_broker(), object2, zone);
+    ArrayConstant = Type::Constant(js_heap_broker(), array, zone);
     UninitializedConstant =
-        Type::HeapConstant(js_heap_broker(), uninitialized, zone);
+        Type::Constant(js_heap_broker(), uninitialized, zone);
 
     values.push_back(smi);
     values.push_back(boxed_smi);
@@ -84,11 +89,13 @@ class Types {
     values.push_back(object2);
     values.push_back(array);
     values.push_back(uninitialized);
+    values.push_back(undefined);
+    values.push_back(nan);
     values.push_back(float1);
     values.push_back(float2);
     values.push_back(float3);
     for (ValueVector::iterator it = values.begin(); it != values.end(); ++it) {
-      types.push_back(Type::NewConstant(js_heap_broker(), *it, zone));
+      types.push_back(Type::Constant(js_heap_broker(), *it, zone));
     }
 
     integers.push_back(isolate->factory()->NewNumber(-V8_INFINITY));
@@ -109,19 +116,6 @@ class Types {
     }
   }
 
-  Handle<i::Map> object_map;
-
-  Handle<i::Smi> smi;
-  Handle<i::HeapNumber> boxed_smi;
-  Handle<i::HeapNumber> signed32;
-  Handle<i::HeapNumber> float1;
-  Handle<i::HeapNumber> float2;
-  Handle<i::HeapNumber> float3;
-  Handle<i::JSObject> object1;
-  Handle<i::JSObject> object2;
-  Handle<i::JSArray> array;
-  Handle<i::Oddball> uninitialized;
-
 #define DECLARE_TYPE(name, value) Type name;
   PROPER_BITSET_TYPE_LIST(DECLARE_TYPE)
 #undef DECLARE_TYPE
@@ -145,12 +139,12 @@ class Types {
   ValueVector values;
   ValueVector integers;  // "Integer" values used for range limits.
 
-  Type NewConstant(Handle<i::Object> value) {
-    return Type::NewConstant(js_heap_broker(), value, zone_);
+  Type Constant(Handle<i::Object> value) {
+    return Type::Constant(js_heap_broker(), value, zone_);
   }
 
   Type HeapConstant(Handle<i::HeapObject> value) {
-    return Type::HeapConstant(js_heap_broker(), value, zone_);
+    return Type::Constant(js_heap_broker(), value, zone_);
   }
 
   Type Range(double min, double max) { return Type::Range(min, max, zone_); }
@@ -188,7 +182,7 @@ class Types {
       }
       case 1: {  // constant
         int i = rng_->NextInt(static_cast<int>(values.size()));
-        return Type::NewConstant(js_heap_broker(), values[i], zone_);
+        return Type::Constant(js_heap_broker(), values[i], zone_);
       }
       case 2: {  // range
         int i = rng_->NextInt(static_cast<int>(integers.size()));
diff --git a/deps/v8/test/common/wasm/wasm-macro-gen.h b/deps/v8/test/common/wasm/wasm-macro-gen.h
index 5a914c79a2..1da88a406a 100644
--- a/deps/v8/test/common/wasm/wasm-macro-gen.h
+++ b/deps/v8/test/common/wasm/wasm-macro-gen.h
@@ -27,8 +27,10 @@
 #define ACTIVE_NO_INDEX 0
 #define PASSIVE 1
 #define ACTIVE_WITH_INDEX 2
+#define DECLARATIVE 3
 #define PASSIVE_WITH_ELEMENTS 5
 #define ACTIVE_WITH_ELEMENTS 6
+#define DECLARATIVE_WITH_ELEMENTS 7
 
 // The table index field in an element segment was repurposed as a flags field.
 // To specify a table index, we have to set the flag value to 2, followed by
@@ -87,9 +89,8 @@
 #define WASM_BLOCK_F(...) kExprBlock, kLocalF32, __VA_ARGS__, kExprEnd
 #define WASM_BLOCK_D(...) kExprBlock, kLocalF64, __VA_ARGS__, kExprEnd
 
-#define WASM_BLOCK_T(t, ...)                                                   \
-  kExprBlock, static_cast<byte>(ValueTypes::ValueTypeCodeFor(t)), __VA_ARGS__, \
-      kExprEnd
+#define WASM_BLOCK_T(t, ...) \
+  kExprBlock, static_cast<byte>((t).value_type_code()), __VA_ARGS__, kExprEnd
 
 #define WASM_BLOCK_X(index, ...)                                  \
   kExprBlock, static_cast<byte>(index), __VA_ARGS__, kExprEnd
@@ -102,18 +103,16 @@
 #define WASM_LOOP_F(...) kExprLoop, kLocalF32, __VA_ARGS__, kExprEnd
 #define WASM_LOOP_D(...) kExprLoop, kLocalF64, __VA_ARGS__, kExprEnd
 
-#define WASM_LOOP_T(t, ...)                                                   \
-  kExprLoop, static_cast<byte>(ValueTypes::ValueTypeCodeFor(t)), __VA_ARGS__, \
-      kExprEnd
+#define WASM_LOOP_T(t, ...) \
+  kExprLoop, static_cast<byte>((t).value_type_code()), __VA_ARGS__, kExprEnd
 
 #define WASM_LOOP_X(index, ...)                                   \
   kExprLoop, static_cast<byte>(index), __VA_ARGS__, kExprEnd
 
 #define WASM_IF(cond, ...) cond, kExprIf, kLocalVoid, __VA_ARGS__, kExprEnd
 
-#define WASM_IF_T(t, cond, ...)                                      \
-  cond, kExprIf, static_cast<byte>(ValueTypes::ValueTypeCodeFor(t)), \
-      __VA_ARGS__, kExprEnd
+#define WASM_IF_T(t, cond, ...) \
+  cond, kExprIf, static_cast<byte>((t).value_type_code()), __VA_ARGS__, kExprEnd
 
 #define WASM_IF_X(index, cond, ...)                                   \
   cond, kExprIf, static_cast<byte>(index), __VA_ARGS__, kExprEnd
@@ -130,16 +129,16 @@
 #define WASM_IF_ELSE_D(cond, tstmt, fstmt) \
   cond, kExprIf, kLocalF64, tstmt, kExprElse, fstmt, kExprEnd
 
-#define WASM_IF_ELSE_T(t, cond, tstmt, fstmt)                               \
-  cond, kExprIf, static_cast<byte>(ValueTypes::ValueTypeCodeFor(t)), tstmt, \
-      kExprElse, fstmt, kExprEnd
+#define WASM_IF_ELSE_T(t, cond, tstmt, fstmt)                                \
+  cond, kExprIf, static_cast<byte>((t).value_type_code()), tstmt, kExprElse, \
+      fstmt, kExprEnd
 
 #define WASM_IF_ELSE_X(index, cond, tstmt, fstmt)                            \
   cond, kExprIf, static_cast<byte>(index), tstmt, kExprElse, fstmt, kExprEnd
 
-#define WASM_TRY_CATCH_T(t, trystmt, catchstmt)                          \
-  kExprTry, static_cast<byte>(ValueTypes::ValueTypeCodeFor(t)), trystmt, \
-      kExprCatch, catchstmt, kExprEnd
+#define WASM_TRY_CATCH_T(t, trystmt, catchstmt)                            \
+  kExprTry, static_cast<byte>((t).value_type_code()), trystmt, kExprCatch, \
+      catchstmt, kExprEnd
 
 #define WASM_SELECT(tval, fval, cond) tval, fval, cond, kExprSelect
 #define WASM_SELECT_I(tval, fval, cond) \
diff --git a/deps/v8/test/common/wasm/wasm-module-runner.cc b/deps/v8/test/common/wasm/wasm-module-runner.cc
index 5495f9330a..067188bba0 100644
--- a/deps/v8/test/common/wasm/wasm-module-runner.cc
+++ b/deps/v8/test/common/wasm/wasm-module-runner.cc
@@ -77,7 +77,8 @@ bool InterpretWasmModuleForTesting(Isolate* isolate,
     return false;
   }
   int function_index = function->function_index();
-  FunctionSig* signature = instance->module()->functions[function_index].sig;
+  const FunctionSig* signature =
+      instance->module()->functions[function_index].sig;
   size_t param_count = signature->parameter_count();
   std::unique_ptr<WasmValue[]> arguments(new WasmValue[param_count]);
 
@@ -88,29 +89,29 @@ bool InterpretWasmModuleForTesting(Isolate* isolate,
 
   // Fill the parameters up with default values.
   for (size_t i = argc; i < param_count; ++i) {
-    switch (signature->GetParam(i)) {
-      case kWasmI32:
+    switch (signature->GetParam(i).kind()) {
+      case ValueType::kI32:
         arguments[i] = WasmValue(int32_t{0});
         break;
-      case kWasmI64:
+      case ValueType::kI64:
         arguments[i] = WasmValue(int64_t{0});
         break;
-      case kWasmF32:
+      case ValueType::kF32:
         arguments[i] = WasmValue(0.0f);
         break;
-      case kWasmF64:
+      case ValueType::kF64:
         arguments[i] = WasmValue(0.0);
         break;
-      case kWasmAnyRef:
-      case kWasmFuncRef:
-      case kWasmNullRef:
-      case kWasmExnRef:
+      case ValueType::kAnyRef:
+      case ValueType::kFuncRef:
+      case ValueType::kNullRef:
+      case ValueType::kExnRef:
         arguments[i] =
             WasmValue(Handle<Object>::cast(isolate->factory()->null_value()));
         break;
-      case kWasmStmt:
-      case kWasmBottom:
-      case kWasmS128:
+      case ValueType::kStmt:
+      case ValueType::kBottom:
+      case ValueType::kS128:
         UNREACHABLE();
     }
   }
diff --git a/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff.js b/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff.js
new file mode 100644
index 0000000000..e7ba10349c
--- /dev/null
+++ b/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff.js
@@ -0,0 +1,42 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --experimental-wasm-anyref
+
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+// Create a simple Wasm module.
+function create_builder(i) {
+  const builder = new WasmModuleBuilder();
+  builder.addFunction('main', kSig_i_r)
+  .addBody([
+    kExprLocalGet, 0, kExprRefIsNull,
+    ...wasmI32Const(i),
+    kExprI32Add])
+  .exportFunc();
+  return builder;
+}
+
+const instance = create_builder(0).instantiate();
+
+// Test recompilation.
+const Debug = new DebugWrapper();
+Debug.enable();
+assertFalse(%IsLiftoffFunction(instance.exports.main));
+const newInstance = create_builder(1).instantiate();
+assertFalse(%IsLiftoffFunction(newInstance.exports.main));
+
+// Async.
+async function testTierDownToLiftoffAsync() {
+  Debug.disable();
+  const asyncInstance = await create_builder(2).asyncInstantiate();
+
+  // Test recompilation.
+  Debug.enable();
+  assertFalse(%IsLiftoffFunction(asyncInstance.exports.main));
+  const newAsyncInstance = await create_builder(3).asyncInstantiate();
+  assertFalse(%IsLiftoffFunction(newAsyncInstance.exports.main));
+}
+
+assertPromiseResult(testTierDownToLiftoffAsync());
diff --git a/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm.js b/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm.js
new file mode 100644
index 0000000000..20dc1e1c5e
--- /dev/null
+++ b/deps/v8/test/debugger/debug/wasm/debug-enabled-tier-down-wasm.js
@@ -0,0 +1,62 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+const num_functions = 200;
+
+// Create a simple Wasm script.
+function create_builder(delta = 0) {
+  const builder = new WasmModuleBuilder();
+  for (let i = 0; i < num_functions; ++i) {
+    builder.addFunction('f' + i, kSig_i_v)
+        .addBody(wasmI32Const(i + delta))
+        .exportFunc();
+  }
+  return builder;
+}
+
+function checkTieredDown(instance) {
+  for (let i = 0; i < num_functions; ++i) {
+    assertTrue(%IsLiftoffFunction(instance.exports['f' + i]));
+  }
+}
+
+function checkTieredUp(instance) {
+  // Busy waiting until all functions are tiered up.
+  let num_liftoff_functions = 0;
+  while (true) {
+    num_liftoff_functions = 0;
+    for (let i = 0; i < num_functions; ++i) {
+      if (%IsLiftoffFunction(instance.exports['f' + i])) {
+        num_liftoff_functions++;
+      }
+    }
+    if (num_liftoff_functions == 0) return;
+  }
+}
+
+const instance = create_builder().instantiate();
+const Debug = new DebugWrapper();
+Debug.enable();
+checkTieredDown(instance);
+const newInstance = create_builder(num_functions*2).instantiate();
+checkTieredDown(newInstance);
+Debug.disable();
+checkTieredUp(instance);
+checkTieredUp(newInstance);
+
+// Async.
+async function testTierDownToLiftoffAsync() {
+  const asyncInstance = await create_builder(num_functions).asyncInstantiate();
+  Debug.enable();
+  checkTieredDown(asyncInstance);
+  const newAsyncInstance = await create_builder(num_functions*3).asyncInstantiate();
+  checkTieredDown(newAsyncInstance);
+  Debug.disable();
+  checkTieredUp(asyncInstance);
+  checkTieredUp(newAsyncInstance);
+}
+
+assertPromiseResult(testTierDownToLiftoffAsync());
diff --git a/deps/v8/test/debugger/debugger.status b/deps/v8/test/debugger/debugger.status
index d74b55dc6d..a10c503d74 100644
--- a/deps/v8/test/debugger/debugger.status
+++ b/deps/v8/test/debugger/debugger.status
@@ -143,9 +143,21 @@
 ['arch in (s390, s390x, ppc, ppc64)', {
   'regress/regress-crbug-1032042': [SKIP],
   'regress/regress-crbug-840288': [SKIP],
-  'debug/wasm/debug-step-into-wasm': [SKIP],
   'debug/wasm/asm-debug': [SKIP],
+  'debug/wasm/debug-enabled-tier-down-wasm': [SKIP],
+  'debug/wasm/debug-step-into-wasm': [SKIP],
   'debug/wasm/frame-inspection': [SKIP],
 }],
 
+##############################################################################
+['isolates', {
+  # WebAssembly debugging does not work reliably when multiple isolates are
+  # involved (https://crbug.com/v8/10359).
+  # (this list might need to be extended by more debugging tests as they
+  # start flaking)
+  'debug/wasm/debug-enabled-tier-down-wasm': [SKIP],
+  'debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff': [SKIP],
+  'regress/regress-crbug-1032042': [SKIP],
+}],  # 'isolates'
+
 ]
diff --git a/deps/v8/test/debugging/debugging.status b/deps/v8/test/debugging/debugging.status
new file mode 100644
index 0000000000..b5ebc84474
--- /dev/null
+++ b/deps/v8/test/debugging/debugging.status
@@ -0,0 +1,5 @@
+# Copyright 2019 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+[]
diff --git a/deps/v8/test/debugging/testcfg.py b/deps/v8/test/debugging/testcfg.py
new file mode 100644
index 0000000000..6f7fedb25b
--- /dev/null
+++ b/deps/v8/test/debugging/testcfg.py
@@ -0,0 +1,99 @@
+# Copyright 2019 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import re
+import shlex
+import sys
+
+from testrunner.local import testsuite
+from testrunner.local import utils
+from testrunner.objects import testcase
+from testrunner.outproc import message
+
+PY_FLAGS_PATTERN = re.compile(r"#\s+Flags:(.*)")
+
+class PYTestCase(testcase.TestCase):
+
+  def get_shell(self):
+    return os.path.splitext(sys.executable)[0]
+
+  def get_command(self):
+    return super(PYTestCase, self).get_command()
+
+  def _get_cmd_params(self):
+    return self._get_files_params() + ['--', os.path.join(self._test_config.shell_dir, 'd8')] + self._get_source_flags()
+
+  def _get_shell_flags(self):
+    return []
+
+
+class TestCase(PYTestCase):
+
+  def __init__(self, *args, **kwargs):
+    super(TestCase, self).__init__(*args, **kwargs)
+
+    source = self.get_source()
+    self._source_files = self._parse_source_files(source)
+    self._source_flags = self._parse_source_flags(source)
+
+  def _parse_source_files(self, source):
+    files = []
+    files.append(self._get_source_path())
+    return files
+
+  def _parse_source_flags(self, source=None):
+    source = source or self.get_source()
+    flags = []
+    for match in re.findall(PY_FLAGS_PATTERN, source):
+      flags += shlex.split(match.strip())
+    return flags
+
+  def _expected_fail(self):
+    path = self.path
+    while path:
+      head, tail = os.path.split(path)
+      if tail == 'fail':
+        return True
+      path = head
+    return False
+
+  def _get_files_params(self):
+    return self._source_files
+
+  def _get_source_flags(self):
+    return self._source_flags
+
+  def _get_source_path(self):
+    base_path = os.path.join(self.suite.root, self.path)
+    if os.path.exists(base_path + self._get_suffix()):
+      return base_path + self._get_suffix()
+    return base_path + '.py'
+
+  def skip_predictable(self):
+    return super(TestCase, self).skip_predictable() or self._expected_fail()
+
+
+class PYTestLoader(testsuite.GenericTestLoader):
+
+  @property
+  def excluded_files(self):
+    return {'gdb_rsp.py', 'testcfg.py', '__init__.py'}
+
+  @property
+  def extensions(self):
+    return ['.py']
+
+
+class TestSuite(testsuite.TestSuite):
+
+  def _test_loader_class(self):
+    return PYTestLoader
+
+  def _test_class(self):
+    return TestCase
+
+
+def GetSuite(*args, **kwargs):
+  return TestSuite(*args, **kwargs)
diff --git a/deps/v8/test/debugging/wasm/gdb-server/connect.py b/deps/v8/test/debugging/wasm/gdb-server/connect.py
new file mode 100644
index 0000000000..f2bac29425
--- /dev/null
+++ b/deps/v8/test/debugging/wasm/gdb-server/connect.py
@@ -0,0 +1,41 @@
+# Copyright 2019 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Flags: -expose-wasm --wasm_gdb_remote --wasm-pause-waiting-for-debugger --wasm-interpret-all test/debugging/wasm/gdb-server/test_files/test.js
+
+import os
+import subprocess
+import unittest
+import sys
+import gdb_rsp
+
+# These are set up by Main().
+COMMAND = None
+
+
+class Tests(unittest.TestCase):
+  def test_disconnect(self):
+    process = gdb_rsp.PopenDebugStub(COMMAND)
+    try:
+      # Connect and record the instruction pointer.
+      connection = gdb_rsp.GdbRspConnection()
+      connection.Close()
+      # Reconnect 3 times.
+      for _ in range(3):
+        connection = gdb_rsp.GdbRspConnection()
+        connection.Close()
+    finally:
+      gdb_rsp.KillProcess(process)
+
+
+def Main():
+  index = sys.argv.index('--')
+  args = sys.argv[index + 1:]
+  # The remaining arguments go to unittest.main().
+  global COMMAND
+  COMMAND = args
+  unittest.main(argv=sys.argv[:index])
+
+if __name__ == '__main__':
+  Main()
diff --git a/deps/v8/test/debugging/wasm/gdb-server/gdb_rsp.py b/deps/v8/test/debugging/wasm/gdb-server/gdb_rsp.py
new file mode 100644
index 0000000000..131725f83d
--- /dev/null
+++ b/deps/v8/test/debugging/wasm/gdb-server/gdb_rsp.py
@@ -0,0 +1,73 @@
+# Copyright 2019 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import socket
+import subprocess
+import time
+
+SOCKET_ADDR = ('localhost', 8765)
+
+
+def EnsurePortIsAvailable(addr=SOCKET_ADDR):
+  # As a sanity check, check that the TCP port is available by binding to it
+  # ourselves (and then unbinding).  Otherwise, we could end up talking to an
+  # old instance of the GDB stub that is still hanging around, or to some
+  # unrelated service that uses the same port number. Of course, there is still
+  # a race condition because an unrelated process could bind the port after we
+  # unbind.
+  sock = socket.socket()
+  sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
+  sock.bind(addr)
+  sock.close()
+
+
+class GdbRspConnection(object):
+
+  def __init__(self, addr=SOCKET_ADDR):
+    self._socket = self._Connect(addr)
+
+  def _Connect(self, addr):
+    # We have to poll because we do not know when the GDB stub has successfully
+    # done bind() on the TCP port. This is inherently unreliable.
+    timeout_in_seconds = 10
+    poll_time_in_seconds = 0.1
+    for i in xrange(int(timeout_in_seconds / poll_time_in_seconds)):
+      # On Mac OS X, we have to create a new socket FD for each retry.
+      sock = socket.socket()
+      # Do not delay sending small packets. This significantly speeds up debug
+      # stub tests.
+      sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, True)
+      try:
+        sock.connect(addr)
+      except socket.error:
+        # Retry after a delay.
+        time.sleep(poll_time_in_seconds)
+      else:
+        return sock
+    raise Exception('Could not connect to the debug stub in %i seconds'
+                    % timeout_in_seconds)
+
+  def Close(self):
+    self._socket.close()
+
+
+def PopenDebugStub(command):
+  EnsurePortIsAvailable()
+  return subprocess.Popen(command)
+
+
+def KillProcess(process):
+  if process.returncode is not None:
+    # kill() won't work if we've already wait()'ed on the process.
+    return
+  try:
+    process.kill()
+  except OSError:
+    if sys.platform == 'win32':
+      # If process is already terminated, kill() throws
+      # "WindowsError: [Error 5] Access is denied" on Windows.
+      pass
+    else:
+      raise
+  process.wait()
diff --git a/deps/v8/test/debugging/wasm/gdb-server/test_files/test.js b/deps/v8/test/debugging/wasm/gdb-server/test_files/test.js
new file mode 100644
index 0000000000..0959edca30
--- /dev/null
+++ b/deps/v8/test/debugging/wasm/gdb-server/test_files/test.js
@@ -0,0 +1,33 @@
+
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+var builder = new WasmModuleBuilder();
+builder.addFunction('mul', kSig_i_ii)
+// input is 2 args of type int and output is int
+.addBody([
+  kExprLocalGet, 0, // local.get i0
+  kExprLocalGet, 1, // local.get i1
+  kExprI32Mul]) // i32.sub i0 i1
+.exportFunc();
+
+const instance = builder.instantiate();
+const wasm_f = instance.exports.mul;
+
+function f() {
+  var result = wasm_f(21, 2);
+  return result;
+}
+
+try {
+    let val = 0;
+    while (true) {
+        val += f();
+    }
+}
+catch (e) {
+    print('*exception:* ' + e);
+}
diff --git a/deps/v8/test/fuzzer/multi-return.cc b/deps/v8/test/fuzzer/multi-return.cc
index da151e7115..6e4b099fcd 100644
--- a/deps/v8/test/fuzzer/multi-return.cc
+++ b/deps/v8/test/fuzzer/multi-return.cc
@@ -121,14 +121,14 @@ CallDescriptor* CreateRandomCallDescriptor(Zone* zone, size_t return_count,
   wasm::FunctionSig::Builder builder(zone, return_count, param_count);
   for (size_t i = 0; i < param_count; i++) {
     MachineType type = RandomType(input);
-    builder.AddParam(wasm::ValueTypes::ValueTypeFor(type));
+    builder.AddParam(wasm::ValueType::For(type));
   }
   // Read the end byte of the parameters.
   input->NextInt8(1);
 
   for (size_t i = 0; i < return_count; i++) {
     MachineType type = RandomType(input);
-    builder.AddReturn(wasm::ValueTypes::ValueTypeFor(type));
+    builder.AddReturn(wasm::ValueType::For(type));
   }
 
   return compiler::GetWasmCallDescriptor(zone, builder.Build());
diff --git a/deps/v8/test/fuzzer/regexp-builtins.cc b/deps/v8/test/fuzzer/regexp-builtins.cc
index 6dafe950fb..61149f134e 100644
--- a/deps/v8/test/fuzzer/regexp-builtins.cc
+++ b/deps/v8/test/fuzzer/regexp-builtins.cc
@@ -62,8 +62,7 @@ REGEXP_BUILTINS(CASE)
 #undef CASE
 
 v8::Local<v8::String> v8_str(v8::Isolate* isolate, const char* s) {
-  return v8::String::NewFromUtf8(isolate, s, v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(isolate, s).ToLocalChecked();
 }
 
 v8::MaybeLocal<v8::Value> CompileRun(v8::Local<v8::Context> context,
diff --git a/deps/v8/test/fuzzer/wasm-async.cc b/deps/v8/test/fuzzer/wasm-async.cc
index e52b418784..3e121298e0 100644
--- a/deps/v8/test/fuzzer/wasm-async.cc
+++ b/deps/v8/test/fuzzer/wasm-async.cc
@@ -78,7 +78,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   // Wait for the promise to resolve.
   while (!done) {
     support->PumpMessageLoop(platform::MessageLoopBehavior::kWaitForWork);
-    isolate->RunMicrotasks();
+    isolate->PerformMicrotaskCheckpoint();
   }
   return 0;
 }
diff --git a/deps/v8/test/fuzzer/wasm-compile.cc b/deps/v8/test/fuzzer/wasm-compile.cc
index 3ffaa89203..1241061a7b 100644
--- a/deps/v8/test/fuzzer/wasm-compile.cc
+++ b/deps/v8/test/fuzzer/wasm-compile.cc
@@ -16,6 +16,7 @@
 #include "src/wasm/wasm-interpreter.h"
 #include "src/wasm/wasm-module-builder.h"
 #include "src/wasm/wasm-module.h"
+#include "src/wasm/wasm-opcodes.h"
 #include "test/common/wasm/flag-utils.h"
 #include "test/common/wasm/test-signatures.h"
 #include "test/common/wasm/wasm-module-runner.h"
@@ -79,6 +80,9 @@ class DataRange {
 };
 
 ValueType GetValueType(DataRange* data) {
+  // TODO(v8:8460): We do not add kWasmS128 here yet because this method is used
+  // to generate globals, and since we do not have v128.const yet, there is no
+  // way to specify an initial value a global of this type.
   switch (data->get<uint8_t>() % 4) {
     case 0:
       return kWasmI32;
@@ -93,7 +97,7 @@ ValueType GetValueType(DataRange* data) {
 }
 
 class WasmGenerator {
-  template <WasmOpcode Op, ValueType... Args>
+  template <WasmOpcode Op, ValueType::Kind... Args>
   void op(DataRange* data) {
     Generate<Args...>(data);
     builder_->Emit(Op);
@@ -105,8 +109,7 @@ class WasmGenerator {
                ValueType br_type)
         : gen_(gen) {
       gen->blocks_.push_back(br_type);
-      gen->builder_->EmitWithU8(block_type,
-                                ValueTypes::ValueTypeCodeFor(result_type));
+      gen->builder_->EmitWithU8(block_type, result_type.value_type_code());
     }
 
     ~BlockScope() {
@@ -118,28 +121,28 @@ class WasmGenerator {
     WasmGenerator* const gen_;
   };
 
-  template <ValueType T>
+  template <ValueType::Kind T>
   void block(DataRange* data) {
-    BlockScope block_scope(this, kExprBlock, T, T);
+    BlockScope block_scope(this, kExprBlock, ValueType(T), ValueType(T));
     Generate<T>(data);
   }
 
-  template <ValueType T>
+  template <ValueType::Kind T>
   void loop(DataRange* data) {
     // When breaking to a loop header, don't provide any input value (hence
     // kWasmStmt).
-    BlockScope block_scope(this, kExprLoop, T, kWasmStmt);
+    BlockScope block_scope(this, kExprLoop, ValueType(T), kWasmStmt);
     Generate<T>(data);
   }
 
   enum IfType { kIf, kIfElse };
 
-  template <ValueType T, IfType type>
+  template <ValueType::Kind T, IfType type>
   void if_(DataRange* data) {
-    static_assert(T == kWasmStmt || type == kIfElse,
+    static_assert(T == ValueType::kStmt || type == kIfElse,
                   "if without else cannot produce a value");
-    Generate<kWasmI32>(data);
-    BlockScope block_scope(this, kExprIf, T, T);
+    Generate<ValueType::kI32>(data);
+    BlockScope block_scope(this, kExprIf, ValueType(T), ValueType(T));
     Generate<T>(data);
     if (type == kIfElse) {
       builder_->Emit(kExprElse);
@@ -158,7 +161,7 @@ class WasmGenerator {
         kExprBr, static_cast<uint32_t>(blocks_.size()) - 1 - target_block);
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void br_if(DataRange* data) {
     // There is always at least the block representing the function body.
     DCHECK(!blocks_.empty());
@@ -169,12 +172,15 @@ class WasmGenerator {
     Generate(kWasmI32, data);
     builder_->EmitWithI32V(
         kExprBrIf, static_cast<uint32_t>(blocks_.size()) - 1 - target_block);
-    ConvertOrGenerate(break_type, wanted_type, data);
+    ConvertOrGenerate(break_type, ValueType(wanted_type), data);
   }
 
   // TODO(eholk): make this function constexpr once gcc supports it
   static uint8_t max_alignment(WasmOpcode memop) {
     switch (memop) {
+      case kExprS128LoadMem:
+      case kExprS128StoreMem:
+        return 4;
       case kExprI64LoadMem:
       case kExprF64LoadMem:
       case kExprI64StoreMem:
@@ -186,6 +192,8 @@ class WasmGenerator {
       case kExprI64AtomicAnd:
       case kExprI64AtomicOr:
       case kExprI64AtomicXor:
+      case kExprI64AtomicExchange:
+      case kExprI64AtomicCompareExchange:
         return 3;
       case kExprI32LoadMem:
       case kExprI64LoadMem32S:
@@ -203,11 +211,15 @@ class WasmGenerator {
       case kExprI32AtomicAnd:
       case kExprI32AtomicOr:
       case kExprI32AtomicXor:
+      case kExprI32AtomicExchange:
+      case kExprI32AtomicCompareExchange:
       case kExprI64AtomicAdd32U:
       case kExprI64AtomicSub32U:
       case kExprI64AtomicAnd32U:
       case kExprI64AtomicOr32U:
       case kExprI64AtomicXor32U:
+      case kExprI64AtomicExchange32U:
+      case kExprI64AtomicCompareExchange32U:
         return 2;
       case kExprI32LoadMem16S:
       case kExprI32LoadMem16U:
@@ -224,11 +236,15 @@ class WasmGenerator {
       case kExprI32AtomicAnd16U:
       case kExprI32AtomicOr16U:
       case kExprI32AtomicXor16U:
+      case kExprI32AtomicExchange16U:
+      case kExprI32AtomicCompareExchange16U:
       case kExprI64AtomicAdd16U:
       case kExprI64AtomicSub16U:
       case kExprI64AtomicAnd16U:
       case kExprI64AtomicOr16U:
       case kExprI64AtomicXor16U:
+      case kExprI64AtomicExchange16U:
+      case kExprI64AtomicCompareExchange16U:
         return 1;
       case kExprI32LoadMem8S:
       case kExprI32LoadMem8U:
@@ -245,27 +261,31 @@ class WasmGenerator {
       case kExprI32AtomicAnd8U:
       case kExprI32AtomicOr8U:
       case kExprI32AtomicXor8U:
+      case kExprI32AtomicExchange8U:
+      case kExprI32AtomicCompareExchange8U:
       case kExprI64AtomicAdd8U:
       case kExprI64AtomicSub8U:
       case kExprI64AtomicAnd8U:
       case kExprI64AtomicOr8U:
       case kExprI64AtomicXor8U:
+      case kExprI64AtomicExchange8U:
+      case kExprI64AtomicCompareExchange8U:
         return 0;
       default:
         return 0;
     }
   }
 
-  template <WasmOpcode memory_op, ValueType... arg_types>
+  template <WasmOpcode memory_op, ValueType::Kind... arg_types>
   void memop(DataRange* data) {
     const uint8_t align = data->get<uint8_t>() % (max_alignment(memory_op) + 1);
     const uint32_t offset = data->get<uint32_t>();
 
     // Generate the index and the arguments, if any.
-    Generate<kWasmI32, arg_types...>(data);
+    Generate<ValueType::kI32, arg_types...>(data);
 
-    if ((memory_op & 0xfe00) == 0xfe00) {
-      // This is an atomic-load or atomic-store.
+    if (WasmOpcodes::IsPrefixOpcode(static_cast<WasmOpcode>(memory_op >> 8))) {
+      DCHECK(memory_op >> 8 == kAtomicPrefix || memory_op >> 8 == kSimdPrefix);
       builder_->EmitWithPrefix(memory_op);
     } else {
       builder_->Emit(memory_op);
@@ -274,7 +294,7 @@ class WasmGenerator {
     builder_->EmitU32V(offset);
   }
 
-  template <WasmOpcode Op, ValueType... Args>
+  template <WasmOpcode Op, ValueType::Kind... Args>
   void atomic_op(DataRange* data) {
     const uint8_t align = data->get<uint8_t>() % (max_alignment(Op) + 1);
     const uint32_t offset = data->get<uint32_t>();
@@ -286,26 +306,32 @@ class WasmGenerator {
     builder_->EmitU32V(offset);
   }
 
+  template <WasmOpcode Op, ValueType::Kind... Args>
+  void simd_op(DataRange* data) {
+    Generate<Args...>(data);
+    builder_->EmitWithPrefix(Op);
+  }
+
   void drop(DataRange* data) {
     Generate(GetValueType(data), data);
     builder_->Emit(kExprDrop);
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void call(DataRange* data) {
-    call(data, wanted_type);
+    call(data, ValueType(wanted_type));
   }
 
   void Convert(ValueType src, ValueType dst) {
     auto idx = [](ValueType t) -> int {
-      switch (t) {
-        case kWasmI32:
+      switch (t.kind()) {
+        case ValueType::kI32:
           return 0;
-        case kWasmI64:
+        case ValueType::kI64:
           return 1;
-        case kWasmF32:
+        case ValueType::kF32:
           return 2;
-        case kWasmF64:
+        case ValueType::kF64:
           return 3;
         default:
           UNREACHABLE();
@@ -378,32 +404,34 @@ class WasmGenerator {
     return {index, type};
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void local_op(DataRange* data, WasmOpcode opcode) {
     Var local = GetRandomLocal(data);
     // If there are no locals and no parameters, just generate any value (if a
     // value is needed), or do nothing.
     if (!local.is_valid()) {
-      if (wanted_type == kWasmStmt) return;
+      if (wanted_type == ValueType::kStmt) return;
       return Generate<wanted_type>(data);
     }
 
     if (opcode != kExprLocalGet) Generate(local.type, data);
     builder_->EmitWithU32V(opcode, local.index);
-    if (wanted_type != kWasmStmt && local.type != wanted_type) {
-      Convert(local.type, wanted_type);
+    if (wanted_type != ValueType::kStmt && local.type.kind() != wanted_type) {
+      Convert(local.type, ValueType(wanted_type));
     }
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void get_local(DataRange* data) {
-    static_assert(wanted_type != kWasmStmt, "illegal type");
+    static_assert(wanted_type != ValueType::kStmt, "illegal type");
     local_op<wanted_type>(data, kExprLocalGet);
   }
 
-  void set_local(DataRange* data) { local_op<kWasmStmt>(data, kExprLocalSet); }
+  void set_local(DataRange* data) {
+    local_op<ValueType::kStmt>(data, kExprLocalSet);
+  }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void tee_local(DataRange* data) {
     local_op<wanted_type>(data, kExprLocalTee);
   }
@@ -431,44 +459,44 @@ class WasmGenerator {
     return {index, type};
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void global_op(DataRange* data) {
-    constexpr bool is_set = wanted_type == kWasmStmt;
+    constexpr bool is_set = wanted_type == ValueType::kStmt;
     Var global = GetRandomGlobal(data, is_set);
     // If there are no globals, just generate any value (if a value is needed),
     // or do nothing.
     if (!global.is_valid()) {
-      if (wanted_type == kWasmStmt) return;
+      if (wanted_type == ValueType::kStmt) return;
       return Generate<wanted_type>(data);
     }
 
     if (is_set) Generate(global.type, data);
     builder_->EmitWithU32V(is_set ? kExprGlobalSet : kExprGlobalGet,
                            global.index);
-    if (!is_set && global.type != wanted_type) {
-      Convert(global.type, wanted_type);
+    if (!is_set && global.type.kind() != wanted_type) {
+      Convert(global.type, ValueType(wanted_type));
     }
   }
 
-  template <ValueType wanted_type>
+  template <ValueType::Kind wanted_type>
   void get_global(DataRange* data) {
-    static_assert(wanted_type != kWasmStmt, "illegal type");
+    static_assert(wanted_type != ValueType::kStmt, "illegal type");
     global_op<wanted_type>(data);
   }
 
-  template <ValueType select_type>
+  template <ValueType::Kind select_type>
   void select_with_type(DataRange* data) {
-    static_assert(select_type != kWasmStmt, "illegal type for select");
-    Generate<select_type, select_type, kWasmI32>(data);
+    static_assert(select_type != ValueType::kStmt, "illegal type for select");
+    Generate<select_type, select_type, ValueType::kI32>(data);
     // num_types is always 1.
     uint8_t num_types = 1;
     builder_->EmitWithU8U8(kExprSelectWithType, num_types,
-                           ValueTypes::ValueTypeCodeFor(select_type));
+                           ValueType(select_type).value_type_code());
   }
 
-  void set_global(DataRange* data) { global_op<kWasmStmt>(data); }
+  void set_global(DataRange* data) { global_op<ValueType::kStmt>(data); }
 
-  template <ValueType... Types>
+  template <ValueType::Kind... Types>
   void sequence(DataRange* data) {
     Generate<Types...>(data);
   }
@@ -526,10 +554,10 @@ class WasmGenerator {
 
   void Generate(ValueType type, DataRange* data);
 
-  template <ValueType T>
+  template <ValueType::Kind T>
   void Generate(DataRange* data);
 
-  template <ValueType T1, ValueType T2, ValueType... Ts>
+  template <ValueType::Kind T1, ValueType::Kind T2, ValueType::Kind... Ts>
   void Generate(DataRange* data) {
     // TODO(clemensb): Implement a more even split.
     auto first_data = data->split();
@@ -554,42 +582,46 @@ class WasmGenerator {
 };
 
 template <>
-void WasmGenerator::Generate<kWasmStmt>(DataRange* data) {
+void WasmGenerator::Generate<ValueType::kStmt>(DataRange* data) {
   GeneratorRecursionScope rec_scope(this);
   if (recursion_limit_reached() || data->size() == 0) return;
 
   constexpr GenerateFn alternatives[] = {
-      &WasmGenerator::sequence<kWasmStmt, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmStmt, kWasmStmt, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmStmt, kWasmStmt, kWasmStmt,
-                               kWasmStmt, kWasmStmt, kWasmStmt, kWasmStmt>,
-      &WasmGenerator::block<kWasmStmt>,
-      &WasmGenerator::loop<kWasmStmt>,
-      &WasmGenerator::if_<kWasmStmt, kIf>,
-      &WasmGenerator::if_<kWasmStmt, kIfElse>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kStmt,
+                               ValueType::kStmt, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kStmt,
+                               ValueType::kStmt, ValueType::kStmt,
+                               ValueType::kStmt, ValueType::kStmt,
+                               ValueType::kStmt, ValueType::kStmt>,
+      &WasmGenerator::block<ValueType::kStmt>,
+      &WasmGenerator::loop<ValueType::kStmt>,
+      &WasmGenerator::if_<ValueType::kStmt, kIf>,
+      &WasmGenerator::if_<ValueType::kStmt, kIfElse>,
       &WasmGenerator::br,
-      &WasmGenerator::br_if<kWasmStmt>,
-
-      &WasmGenerator::memop<kExprI32StoreMem, kWasmI32>,
-      &WasmGenerator::memop<kExprI32StoreMem8, kWasmI32>,
-      &WasmGenerator::memop<kExprI32StoreMem16, kWasmI32>,
-      &WasmGenerator::memop<kExprI64StoreMem, kWasmI64>,
-      &WasmGenerator::memop<kExprI64StoreMem8, kWasmI64>,
-      &WasmGenerator::memop<kExprI64StoreMem16, kWasmI64>,
-      &WasmGenerator::memop<kExprI64StoreMem32, kWasmI64>,
-      &WasmGenerator::memop<kExprF32StoreMem, kWasmF32>,
-      &WasmGenerator::memop<kExprF64StoreMem, kWasmF64>,
-      &WasmGenerator::memop<kExprI32AtomicStore, kWasmI32>,
-      &WasmGenerator::memop<kExprI32AtomicStore8U, kWasmI32>,
-      &WasmGenerator::memop<kExprI32AtomicStore16U, kWasmI32>,
-      &WasmGenerator::memop<kExprI64AtomicStore, kWasmI64>,
-      &WasmGenerator::memop<kExprI64AtomicStore8U, kWasmI64>,
-      &WasmGenerator::memop<kExprI64AtomicStore16U, kWasmI64>,
-      &WasmGenerator::memop<kExprI64AtomicStore32U, kWasmI64>,
+      &WasmGenerator::br_if<ValueType::kStmt>,
+
+      &WasmGenerator::memop<kExprI32StoreMem, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI32StoreMem8, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI32StoreMem16, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI64StoreMem, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64StoreMem8, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64StoreMem16, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64StoreMem32, ValueType::kI64>,
+      &WasmGenerator::memop<kExprF32StoreMem, ValueType::kF32>,
+      &WasmGenerator::memop<kExprF64StoreMem, ValueType::kF64>,
+      &WasmGenerator::memop<kExprI32AtomicStore, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI32AtomicStore8U, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI32AtomicStore16U, ValueType::kI32>,
+      &WasmGenerator::memop<kExprI64AtomicStore, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64AtomicStore8U, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64AtomicStore16U, ValueType::kI64>,
+      &WasmGenerator::memop<kExprI64AtomicStore32U, ValueType::kI64>,
+      &WasmGenerator::memop<kExprS128StoreMem, ValueType::kS128>,
 
       &WasmGenerator::drop,
 
-      &WasmGenerator::call<kWasmStmt>,
+      &WasmGenerator::call<ValueType::kStmt>,
 
       &WasmGenerator::set_local,
       &WasmGenerator::set_global};
@@ -598,7 +630,7 @@ void WasmGenerator::Generate<kWasmStmt>(DataRange* data) {
 }
 
 template <>
-void WasmGenerator::Generate<kWasmI32>(DataRange* data) {
+void WasmGenerator::Generate<ValueType::kI32>(DataRange* data) {
   GeneratorRecursionScope rec_scope(this);
   if (recursion_limit_reached() || data->size() <= 1) {
     builder_->EmitI32Const(data->get<uint32_t>());
@@ -611,69 +643,70 @@ void WasmGenerator::Generate<kWasmI32>(DataRange* data) {
       &WasmGenerator::i32_const<3>,
       &WasmGenerator::i32_const<4>,
 
-      &WasmGenerator::sequence<kWasmI32, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmI32>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmI32, kWasmStmt>,
-
-      &WasmGenerator::op<kExprI32Eqz, kWasmI32>,
-      &WasmGenerator::op<kExprI32Eq, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Ne, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32LtS, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32LtU, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32GeS, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32GeU, kWasmI32, kWasmI32>,
-
-      &WasmGenerator::op<kExprI64Eqz, kWasmI64>,
-      &WasmGenerator::op<kExprI64Eq, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Ne, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64LtS, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64LtU, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64GeS, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64GeU, kWasmI64, kWasmI64>,
-
-      &WasmGenerator::op<kExprF32Eq, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Ne, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Lt, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Ge, kWasmF32, kWasmF32>,
-
-      &WasmGenerator::op<kExprF64Eq, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Ne, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Lt, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Ge, kWasmF64, kWasmF64>,
-
-      &WasmGenerator::op<kExprI32Add, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Sub, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Mul, kWasmI32, kWasmI32>,
-
-      &WasmGenerator::op<kExprI32DivS, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32DivU, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32RemS, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32RemU, kWasmI32, kWasmI32>,
-
-      &WasmGenerator::op<kExprI32And, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Ior, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Xor, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Shl, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32ShrU, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32ShrS, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Ror, kWasmI32, kWasmI32>,
-      &WasmGenerator::op<kExprI32Rol, kWasmI32, kWasmI32>,
-
-      &WasmGenerator::op<kExprI32Clz, kWasmI32>,
-      &WasmGenerator::op<kExprI32Ctz, kWasmI32>,
-      &WasmGenerator::op<kExprI32Popcnt, kWasmI32>,
-
-      &WasmGenerator::op<kExprI32ConvertI64, kWasmI64>,
-      &WasmGenerator::op<kExprI32SConvertF32, kWasmF32>,
-      &WasmGenerator::op<kExprI32UConvertF32, kWasmF32>,
-      &WasmGenerator::op<kExprI32SConvertF64, kWasmF64>,
-      &WasmGenerator::op<kExprI32UConvertF64, kWasmF64>,
-      &WasmGenerator::op<kExprI32ReinterpretF32, kWasmF32>,
-
-      &WasmGenerator::block<kWasmI32>,
-      &WasmGenerator::loop<kWasmI32>,
-      &WasmGenerator::if_<kWasmI32, kIfElse>,
-      &WasmGenerator::br_if<kWasmI32>,
+      &WasmGenerator::sequence<ValueType::kI32, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kI32>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kI32,
+                               ValueType::kStmt>,
+
+      &WasmGenerator::op<kExprI32Eqz, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Eq, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Ne, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32LtS, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32LtU, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32GeS, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32GeU, ValueType::kI32, ValueType::kI32>,
+
+      &WasmGenerator::op<kExprI64Eqz, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Eq, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Ne, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64LtS, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64LtU, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64GeS, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64GeU, ValueType::kI64, ValueType::kI64>,
+
+      &WasmGenerator::op<kExprF32Eq, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Ne, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Lt, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Ge, ValueType::kF32, ValueType::kF32>,
+
+      &WasmGenerator::op<kExprF64Eq, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Ne, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Lt, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Ge, ValueType::kF64, ValueType::kF64>,
+
+      &WasmGenerator::op<kExprI32Add, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Sub, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Mul, ValueType::kI32, ValueType::kI32>,
+
+      &WasmGenerator::op<kExprI32DivS, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32DivU, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32RemS, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32RemU, ValueType::kI32, ValueType::kI32>,
+
+      &WasmGenerator::op<kExprI32And, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Ior, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Xor, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Shl, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32ShrU, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32ShrS, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Ror, ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Rol, ValueType::kI32, ValueType::kI32>,
+
+      &WasmGenerator::op<kExprI32Clz, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Ctz, ValueType::kI32>,
+      &WasmGenerator::op<kExprI32Popcnt, ValueType::kI32>,
+
+      &WasmGenerator::op<kExprI32ConvertI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI32SConvertF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprI32UConvertF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprI32SConvertF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprI32UConvertF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprI32ReinterpretF32, ValueType::kF32>,
+
+      &WasmGenerator::block<ValueType::kI32>,
+      &WasmGenerator::loop<ValueType::kI32>,
+      &WasmGenerator::if_<ValueType::kI32, kIfElse>,
+      &WasmGenerator::br_if<ValueType::kI32>,
 
       &WasmGenerator::memop<kExprI32LoadMem>,
       &WasmGenerator::memop<kExprI32LoadMem8S>,
@@ -684,38 +717,72 @@ void WasmGenerator::Generate<kWasmI32>(DataRange* data) {
       &WasmGenerator::memop<kExprI32AtomicLoad8U>,
       &WasmGenerator::memop<kExprI32AtomicLoad16U>,
 
-      &WasmGenerator::atomic_op<kExprI32AtomicAdd, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicSub, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicAnd, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicOr, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicXor, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicAdd8U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicSub8U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicAnd8U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicOr8U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicXor8U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicAdd16U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicSub16U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicAnd16U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicOr16U, kWasmI32, kWasmI32>,
-      &WasmGenerator::atomic_op<kExprI32AtomicXor16U, kWasmI32, kWasmI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAdd, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicSub, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAnd, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicOr, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicXor, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicExchange, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicCompareExchange, ValueType::kI32,
+                                ValueType::kI32, ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAdd8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicSub8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAnd8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicOr8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicXor8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicExchange8U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicCompareExchange8U,
+                                ValueType::kI32, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAdd16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicSub16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicAnd16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicOr16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicXor16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicExchange16U, ValueType::kI32,
+                                ValueType::kI32>,
+      &WasmGenerator::atomic_op<kExprI32AtomicCompareExchange16U,
+                                ValueType::kI32, ValueType::kI32,
+                                ValueType::kI32>,
+
+      &WasmGenerator::simd_op<kExprS1x16AnyTrue, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprS1x8AnyTrue, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprS1x4AnyTrue, ValueType::kS128>,
 
       &WasmGenerator::current_memory,
       &WasmGenerator::grow_memory,
 
-      &WasmGenerator::get_local<kWasmI32>,
-      &WasmGenerator::tee_local<kWasmI32>,
-      &WasmGenerator::get_global<kWasmI32>,
-      &WasmGenerator::op<kExprSelect, kWasmI32, kWasmI32, kWasmI32>,
-      &WasmGenerator::select_with_type<kWasmI32>,
+      &WasmGenerator::get_local<ValueType::kI32>,
+      &WasmGenerator::tee_local<ValueType::kI32>,
+      &WasmGenerator::get_global<ValueType::kI32>,
+      &WasmGenerator::op<kExprSelect, ValueType::kI32, ValueType::kI32,
+                         ValueType::kI32>,
+      &WasmGenerator::select_with_type<ValueType::kI32>,
 
-      &WasmGenerator::call<kWasmI32>};
+      &WasmGenerator::call<ValueType::kI32>};
 
   GenerateOneOf(alternatives, data);
 }
 
 template <>
-void WasmGenerator::Generate<kWasmI64>(DataRange* data) {
+void WasmGenerator::Generate<ValueType::kI64>(DataRange* data) {
   GeneratorRecursionScope rec_scope(this);
   if (recursion_limit_reached() || data->size() <= 1) {
     builder_->EmitI64Const(data->get<int64_t>());
@@ -732,36 +799,37 @@ void WasmGenerator::Generate<kWasmI64>(DataRange* data) {
       &WasmGenerator::i64_const<7>,
       &WasmGenerator::i64_const<8>,
 
-      &WasmGenerator::sequence<kWasmI64, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmI64>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmI64, kWasmStmt>,
-
-      &WasmGenerator::op<kExprI64Add, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Sub, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Mul, kWasmI64, kWasmI64>,
-
-      &WasmGenerator::op<kExprI64DivS, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64DivU, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64RemS, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64RemU, kWasmI64, kWasmI64>,
-
-      &WasmGenerator::op<kExprI64And, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Ior, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Xor, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Shl, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64ShrU, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64ShrS, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Ror, kWasmI64, kWasmI64>,
-      &WasmGenerator::op<kExprI64Rol, kWasmI64, kWasmI64>,
-
-      &WasmGenerator::op<kExprI64Clz, kWasmI64>,
-      &WasmGenerator::op<kExprI64Ctz, kWasmI64>,
-      &WasmGenerator::op<kExprI64Popcnt, kWasmI64>,
-
-      &WasmGenerator::block<kWasmI64>,
-      &WasmGenerator::loop<kWasmI64>,
-      &WasmGenerator::if_<kWasmI64, kIfElse>,
-      &WasmGenerator::br_if<kWasmI64>,
+      &WasmGenerator::sequence<ValueType::kI64, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kI64>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kI64,
+                               ValueType::kStmt>,
+
+      &WasmGenerator::op<kExprI64Add, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Sub, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Mul, ValueType::kI64, ValueType::kI64>,
+
+      &WasmGenerator::op<kExprI64DivS, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64DivU, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64RemS, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64RemU, ValueType::kI64, ValueType::kI64>,
+
+      &WasmGenerator::op<kExprI64And, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Ior, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Xor, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Shl, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64ShrU, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64ShrS, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Ror, ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Rol, ValueType::kI64, ValueType::kI64>,
+
+      &WasmGenerator::op<kExprI64Clz, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Ctz, ValueType::kI64>,
+      &WasmGenerator::op<kExprI64Popcnt, ValueType::kI64>,
+
+      &WasmGenerator::block<ValueType::kI64>,
+      &WasmGenerator::loop<ValueType::kI64>,
+      &WasmGenerator::if_<ValueType::kI64, kIfElse>,
+      &WasmGenerator::br_if<ValueType::kI64>,
 
       &WasmGenerator::memop<kExprI64LoadMem>,
       &WasmGenerator::memop<kExprI64LoadMem8S>,
@@ -775,40 +843,80 @@ void WasmGenerator::Generate<kWasmI64>(DataRange* data) {
       &WasmGenerator::memop<kExprI64AtomicLoad16U>,
       &WasmGenerator::memop<kExprI64AtomicLoad32U>,
 
-      &WasmGenerator::atomic_op<kExprI64AtomicAdd, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicSub, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAnd, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicOr, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicXor, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAdd8U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicSub8U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAnd8U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicOr8U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicXor8U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAdd16U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicSub16U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAnd16U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicOr16U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicXor16U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAdd32U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicSub32U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicAnd32U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicOr32U, kWasmI32, kWasmI64>,
-      &WasmGenerator::atomic_op<kExprI64AtomicXor32U, kWasmI32, kWasmI64>,
-
-      &WasmGenerator::get_local<kWasmI64>,
-      &WasmGenerator::tee_local<kWasmI64>,
-      &WasmGenerator::get_global<kWasmI64>,
-      &WasmGenerator::op<kExprSelect, kWasmI64, kWasmI64, kWasmI32>,
-      &WasmGenerator::select_with_type<kWasmI64>,
-
-      &WasmGenerator::call<kWasmI64>};
+      &WasmGenerator::atomic_op<kExprI64AtomicAdd, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicSub, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAnd, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicOr, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicXor, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicExchange, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicCompareExchange, ValueType::kI32,
+                                ValueType::kI64, ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAdd8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicSub8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAnd8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicOr8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicXor8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicExchange8U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicCompareExchange8U,
+                                ValueType::kI32, ValueType::kI64,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAdd16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicSub16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAnd16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicOr16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicXor16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicExchange16U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicCompareExchange16U,
+                                ValueType::kI32, ValueType::kI64,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAdd32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicSub32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicAnd32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicOr32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicXor32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicExchange32U, ValueType::kI32,
+                                ValueType::kI64>,
+      &WasmGenerator::atomic_op<kExprI64AtomicCompareExchange32U,
+                                ValueType::kI32, ValueType::kI64,
+                                ValueType::kI64>,
+
+      &WasmGenerator::get_local<ValueType::kI64>,
+      &WasmGenerator::tee_local<ValueType::kI64>,
+      &WasmGenerator::get_global<ValueType::kI64>,
+      &WasmGenerator::op<kExprSelect, ValueType::kI64, ValueType::kI64,
+                         ValueType::kI32>,
+      &WasmGenerator::select_with_type<ValueType::kI64>,
+
+      &WasmGenerator::call<ValueType::kI64>};
 
   GenerateOneOf(alternatives, data);
 }
 
 template <>
-void WasmGenerator::Generate<kWasmF32>(DataRange* data) {
+void WasmGenerator::Generate<ValueType::kF32>(DataRange* data) {
   GeneratorRecursionScope rec_scope(this);
   if (recursion_limit_reached() || data->size() <= sizeof(float)) {
     builder_->EmitF32Const(data->get<float>());
@@ -816,52 +924,54 @@ void WasmGenerator::Generate<kWasmF32>(DataRange* data) {
   }
 
   constexpr GenerateFn alternatives[] = {
-      &WasmGenerator::sequence<kWasmF32, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmF32>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmF32, kWasmStmt>,
-
-      &WasmGenerator::op<kExprF32Abs, kWasmF32>,
-      &WasmGenerator::op<kExprF32Neg, kWasmF32>,
-      &WasmGenerator::op<kExprF32Ceil, kWasmF32>,
-      &WasmGenerator::op<kExprF32Floor, kWasmF32>,
-      &WasmGenerator::op<kExprF32Trunc, kWasmF32>,
-      &WasmGenerator::op<kExprF32NearestInt, kWasmF32>,
-      &WasmGenerator::op<kExprF32Sqrt, kWasmF32>,
-      &WasmGenerator::op<kExprF32Add, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Sub, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Mul, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Div, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Min, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32Max, kWasmF32, kWasmF32>,
-      &WasmGenerator::op<kExprF32CopySign, kWasmF32, kWasmF32>,
-
-      &WasmGenerator::op<kExprF32SConvertI32, kWasmI32>,
-      &WasmGenerator::op<kExprF32UConvertI32, kWasmI32>,
-      &WasmGenerator::op<kExprF32SConvertI64, kWasmI64>,
-      &WasmGenerator::op<kExprF32UConvertI64, kWasmI64>,
-      &WasmGenerator::op<kExprF32ConvertF64, kWasmF64>,
-      &WasmGenerator::op<kExprF32ReinterpretI32, kWasmI32>,
-
-      &WasmGenerator::block<kWasmF32>,
-      &WasmGenerator::loop<kWasmF32>,
-      &WasmGenerator::if_<kWasmF32, kIfElse>,
-      &WasmGenerator::br_if<kWasmF32>,
+      &WasmGenerator::sequence<ValueType::kF32, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kF32>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kF32,
+                               ValueType::kStmt>,
+
+      &WasmGenerator::op<kExprF32Abs, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Neg, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Ceil, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Floor, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Trunc, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32NearestInt, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Sqrt, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Add, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Sub, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Mul, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Div, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Min, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32Max, ValueType::kF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF32CopySign, ValueType::kF32, ValueType::kF32>,
+
+      &WasmGenerator::op<kExprF32SConvertI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprF32UConvertI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprF32SConvertI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprF32UConvertI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprF32ConvertF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF32ReinterpretI32, ValueType::kI32>,
+
+      &WasmGenerator::block<ValueType::kF32>,
+      &WasmGenerator::loop<ValueType::kF32>,
+      &WasmGenerator::if_<ValueType::kF32, kIfElse>,
+      &WasmGenerator::br_if<ValueType::kF32>,
 
       &WasmGenerator::memop<kExprF32LoadMem>,
 
-      &WasmGenerator::get_local<kWasmF32>,
-      &WasmGenerator::tee_local<kWasmF32>,
-      &WasmGenerator::get_global<kWasmF32>,
-      &WasmGenerator::op<kExprSelect, kWasmF32, kWasmF32, kWasmI32>,
-      &WasmGenerator::select_with_type<kWasmF32>,
+      &WasmGenerator::get_local<ValueType::kF32>,
+      &WasmGenerator::tee_local<ValueType::kF32>,
+      &WasmGenerator::get_global<ValueType::kF32>,
+      &WasmGenerator::op<kExprSelect, ValueType::kF32, ValueType::kF32,
+                         ValueType::kI32>,
+      &WasmGenerator::select_with_type<ValueType::kF32>,
 
-      &WasmGenerator::call<kWasmF32>};
+      &WasmGenerator::call<ValueType::kF32>};
 
   GenerateOneOf(alternatives, data);
 }
 
 template <>
-void WasmGenerator::Generate<kWasmF64>(DataRange* data) {
+void WasmGenerator::Generate<ValueType::kF64>(DataRange* data) {
   GeneratorRecursionScope rec_scope(this);
   if (recursion_limit_reached() || data->size() <= sizeof(double)) {
     builder_->EmitF64Const(data->get<double>());
@@ -869,67 +979,216 @@ void WasmGenerator::Generate<kWasmF64>(DataRange* data) {
   }
 
   constexpr GenerateFn alternatives[] = {
-      &WasmGenerator::sequence<kWasmF64, kWasmStmt>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmF64>,
-      &WasmGenerator::sequence<kWasmStmt, kWasmF64, kWasmStmt>,
-
-      &WasmGenerator::op<kExprF64Abs, kWasmF64>,
-      &WasmGenerator::op<kExprF64Neg, kWasmF64>,
-      &WasmGenerator::op<kExprF64Ceil, kWasmF64>,
-      &WasmGenerator::op<kExprF64Floor, kWasmF64>,
-      &WasmGenerator::op<kExprF64Trunc, kWasmF64>,
-      &WasmGenerator::op<kExprF64NearestInt, kWasmF64>,
-      &WasmGenerator::op<kExprF64Sqrt, kWasmF64>,
-      &WasmGenerator::op<kExprF64Add, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Sub, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Mul, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Div, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Min, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64Max, kWasmF64, kWasmF64>,
-      &WasmGenerator::op<kExprF64CopySign, kWasmF64, kWasmF64>,
-
-      &WasmGenerator::op<kExprF64SConvertI32, kWasmI32>,
-      &WasmGenerator::op<kExprF64UConvertI32, kWasmI32>,
-      &WasmGenerator::op<kExprF64SConvertI64, kWasmI64>,
-      &WasmGenerator::op<kExprF64UConvertI64, kWasmI64>,
-      &WasmGenerator::op<kExprF64ConvertF32, kWasmF32>,
-      &WasmGenerator::op<kExprF64ReinterpretI64, kWasmI64>,
-
-      &WasmGenerator::block<kWasmF64>,
-      &WasmGenerator::loop<kWasmF64>,
-      &WasmGenerator::if_<kWasmF64, kIfElse>,
-      &WasmGenerator::br_if<kWasmF64>,
+      &WasmGenerator::sequence<ValueType::kF64, ValueType::kStmt>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kF64>,
+      &WasmGenerator::sequence<ValueType::kStmt, ValueType::kF64,
+                               ValueType::kStmt>,
+
+      &WasmGenerator::op<kExprF64Abs, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Neg, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Ceil, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Floor, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Trunc, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64NearestInt, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Sqrt, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Add, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Sub, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Mul, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Div, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Min, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64Max, ValueType::kF64, ValueType::kF64>,
+      &WasmGenerator::op<kExprF64CopySign, ValueType::kF64, ValueType::kF64>,
+
+      &WasmGenerator::op<kExprF64SConvertI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprF64UConvertI32, ValueType::kI32>,
+      &WasmGenerator::op<kExprF64SConvertI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprF64UConvertI64, ValueType::kI64>,
+      &WasmGenerator::op<kExprF64ConvertF32, ValueType::kF32>,
+      &WasmGenerator::op<kExprF64ReinterpretI64, ValueType::kI64>,
+
+      &WasmGenerator::block<ValueType::kF64>,
+      &WasmGenerator::loop<ValueType::kF64>,
+      &WasmGenerator::if_<ValueType::kF64, kIfElse>,
+      &WasmGenerator::br_if<ValueType::kF64>,
 
       &WasmGenerator::memop<kExprF64LoadMem>,
 
-      &WasmGenerator::get_local<kWasmF64>,
-      &WasmGenerator::tee_local<kWasmF64>,
-      &WasmGenerator::get_global<kWasmF64>,
-      &WasmGenerator::op<kExprSelect, kWasmF64, kWasmF64, kWasmI32>,
-      &WasmGenerator::select_with_type<kWasmF64>,
+      &WasmGenerator::get_local<ValueType::kF64>,
+      &WasmGenerator::tee_local<ValueType::kF64>,
+      &WasmGenerator::get_global<ValueType::kF64>,
+      &WasmGenerator::op<kExprSelect, ValueType::kF64, ValueType::kF64,
+                         ValueType::kI32>,
+      &WasmGenerator::select_with_type<ValueType::kF64>,
+
+      &WasmGenerator::call<ValueType::kF64>};
 
-      &WasmGenerator::call<kWasmF64>};
+  GenerateOneOf(alternatives, data);
+}
+
+template <>
+void WasmGenerator::Generate<ValueType::kS128>(DataRange* data) {
+  GeneratorRecursionScope rec_scope(this);
+  if (recursion_limit_reached() || data->size() <= sizeof(int32_t)) {
+    // TODO(v8:8460): v128.const is not implemented yet, and we need a way to
+    // "bottom-out", so use a splat to generate this.
+    builder_->EmitI32Const(data->get<int32_t>());
+    builder_->EmitWithPrefix(kExprI8x16Splat);
+    return;
+  }
+
+  constexpr GenerateFn alternatives[] = {
+      &WasmGenerator::simd_op<kExprI8x16Splat, ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI8x16Eq, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16Ne, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16LtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16LtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16GtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16GtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16LeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16LeU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16GeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16GeU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16Neg, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16Shl, ValueType::kS128, ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI8x16ShrS, ValueType::kS128,
+                              ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI8x16ShrU, ValueType::kS128,
+                              ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI8x16Add, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16AddSaturateS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16AddSaturateU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16Sub, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16SubSaturateS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16SubSaturateU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16MinS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16MinU, ValueType::kS128,
+                              ValueType::kS128>,
+      // I8x16Mul is prototyped but not in the proposal, thus omitted here.
+      &WasmGenerator::simd_op<kExprI8x16MaxS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI8x16MaxU, ValueType::kS128,
+                              ValueType::kS128>,
+
+      &WasmGenerator::simd_op<kExprI16x8Splat, ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI16x8Eq, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8Ne, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8LtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8LtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8GtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8GtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8LeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8LeU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8GeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8GeU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8Neg, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8Shl, ValueType::kS128, ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI16x8ShrS, ValueType::kS128,
+                              ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI16x8ShrU, ValueType::kS128,
+                              ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI16x8Add, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8AddSaturateS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8AddSaturateU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8Sub, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8SubSaturateS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8SubSaturateU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8Mul, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8MinS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8MinU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8MaxS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI16x8MaxU, ValueType::kS128,
+                              ValueType::kS128>,
+
+      &WasmGenerator::simd_op<kExprI32x4Splat, ValueType::kI32>,
+      &WasmGenerator::simd_op<kExprI32x4Eq, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4Ne, ValueType::kS128, ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4LtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4LtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4GtS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4GtU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4LeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4LeU, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4GeS, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI32x4GeU, ValueType::kS128,
+                              ValueType::kS128>,
+
+      &WasmGenerator::simd_op<kExprI64x2Splat, ValueType::kI64>,
+      &WasmGenerator::simd_op<kExprF32x4Splat, ValueType::kF32>,
+      &WasmGenerator::simd_op<kExprF64x2Splat, ValueType::kF64>,
+
+      &WasmGenerator::simd_op<kExprI32x4Add, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprI64x2Add, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprF32x4Add, ValueType::kS128,
+                              ValueType::kS128>,
+      &WasmGenerator::simd_op<kExprF64x2Add, ValueType::kS128,
+                              ValueType::kS128>,
+
+      &WasmGenerator::memop<kExprS128LoadMem>};
 
   GenerateOneOf(alternatives, data);
 }
 
 void WasmGenerator::grow_memory(DataRange* data) {
-  Generate<kWasmI32>(data);
+  Generate<ValueType::kI32>(data);
   builder_->EmitWithU8(kExprMemoryGrow, 0);
 }
 
 void WasmGenerator::Generate(ValueType type, DataRange* data) {
-  switch (type) {
-    case kWasmStmt:
-      return Generate<kWasmStmt>(data);
-    case kWasmI32:
-      return Generate<kWasmI32>(data);
-    case kWasmI64:
-      return Generate<kWasmI64>(data);
-    case kWasmF32:
-      return Generate<kWasmF32>(data);
-    case kWasmF64:
-      return Generate<kWasmF64>(data);
+  switch (type.kind()) {
+    case ValueType::kStmt:
+      return Generate<ValueType::kStmt>(data);
+    case ValueType::kI32:
+      return Generate<ValueType::kI32>(data);
+    case ValueType::kI64:
+      return Generate<ValueType::kI64>(data);
+    case ValueType::kF32:
+      return Generate<ValueType::kF32>(data);
+    case ValueType::kF64:
+      return Generate<ValueType::kF64>(data);
+    case ValueType::kS128:
+      return Generate<ValueType::kS128>(data);
     default:
       UNREACHABLE();
   }
diff --git a/deps/v8/test/fuzzer/wasm-fuzzer-common.cc b/deps/v8/test/fuzzer/wasm-fuzzer-common.cc
index 9fbfa0b3c3..590bc1bc17 100644
--- a/deps/v8/test/fuzzer/wasm-fuzzer-common.cc
+++ b/deps/v8/test/fuzzer/wasm-fuzzer-common.cc
@@ -80,20 +80,20 @@ PrintSig PrintReturns(const FunctionSig* sig) {
   return {sig->return_count(), [=](size_t i) { return sig->GetReturn(i); }};
 }
 const char* ValueTypeToConstantName(ValueType type) {
-  switch (type) {
-    case kWasmI32:
+  switch (type.kind()) {
+    case ValueType::kI32:
       return "kWasmI32";
-    case kWasmI64:
+    case ValueType::kI64:
       return "kWasmI64";
-    case kWasmF32:
+    case ValueType::kF32:
       return "kWasmF32";
-    case kWasmF64:
+    case ValueType::kF64:
       return "kWasmF64";
-    case kWasmAnyRef:
+    case ValueType::kAnyRef:
       return "kWasmAnyRef";
-    case kWasmFuncRef:
+    case ValueType::kFuncRef:
       return "kWasmFuncRef";
-    case kWasmExnRef:
+    case ValueType::kExnRef:
       return "kWasmExnRef";
     default:
       UNREACHABLE();
@@ -151,11 +151,10 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
         "\n"
         "load('test/mjsunit/wasm/wasm-module-builder.js');\n"
         "\n"
-        "(function() {\n"
-        "  const builder = new WasmModuleBuilder();\n";
+        "const builder = new WasmModuleBuilder();\n";
 
   if (module->has_memory) {
-    os << "  builder.addMemory(" << module->initial_pages;
+    os << "builder.addMemory(" << module->initial_pages;
     if (module->has_maximum_pages) {
       os << ", " << module->maximum_pages;
     } else {
@@ -169,12 +168,12 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
   }
 
   for (WasmGlobal& glob : module->globals) {
-    os << "  builder.addGlobal(" << ValueTypeToConstantName(glob.type) << ", "
+    os << "builder.addGlobal(" << ValueTypeToConstantName(glob.type) << ", "
        << glob.mutability << ");\n";
   }
 
   for (const FunctionSig* sig : module->signatures) {
-    os << "  builder.addType(makeSig(" << PrintParameters(sig) << ", "
+    os << "builder.addType(makeSig(" << PrintParameters(sig) << ", "
        << PrintReturns(sig) << "));\n";
   }
 
@@ -183,7 +182,7 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
   // There currently cannot be more than one table.
   DCHECK_GE(1, module->tables.size());
   for (const WasmTable& table : module->tables) {
-    os << "  builder.setTableBounds(" << table.initial_size << ", ";
+    os << "builder.setTableBounds(" << table.initial_size << ", ";
     if (table.has_maximum_size) {
       os << table.maximum_size << ");\n";
     } else {
@@ -191,7 +190,7 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
     }
   }
   for (const WasmElemSegment& elem_segment : module->elem_segments) {
-    os << "  builder.addElementSegment(";
+    os << "builder.addElementSegment(";
     switch (elem_segment.offset.kind) {
       case WasmInitExpr::kGlobalIndex:
         os << elem_segment.offset.val.global_index << ", true";
@@ -207,11 +206,11 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
 
   for (const WasmFunction& func : module->functions) {
     Vector<const uint8_t> func_code = wire_bytes.GetFunctionBytes(&func);
-    os << "  // Generate function " << (func.func_index + 1) << " (out of "
+    os << "// Generate function " << (func.func_index + 1) << " (out of "
        << module->functions.size() << ").\n";
 
     // Add function.
-    os << "  builder.addFunction(undefined, " << func.sig_index
+    os << "builder.addFunction(undefined, " << func.sig_index
        << " /* sig */)\n";
 
     // Add locals.
@@ -219,41 +218,40 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
     DecodeLocalDecls(enabled_features, &decls, func_code.begin(),
                      func_code.end());
     if (!decls.type_list.empty()) {
-      os << "    ";
+      os << "  ";
       for (size_t pos = 0, count = 1, locals = decls.type_list.size();
            pos < locals; pos += count, count = 1) {
         ValueType type = decls.type_list[pos];
         while (pos + count < locals && decls.type_list[pos + count] == type)
           ++count;
-        os << ".addLocals({" << ValueTypes::TypeName(type)
-           << "_count: " << count << "})";
+        os << ".addLocals({" << type.type_name() << "_count: " << count << "})";
       }
       os << "\n";
     }
 
     // Add body.
-    os << "    .addBodyWithEnd([\n";
+    os << "  .addBodyWithEnd([\n";
 
     FunctionBody func_body(func.sig, func.code.offset(), func_code.begin(),
                            func_code.end());
     PrintRawWasmCode(isolate->allocator(), func_body, module, kOmitLocals);
-    os << "            ]);\n";
+    os << "]);\n";
   }
 
   for (WasmExport& exp : module->export_table) {
     if (exp.kind != kExternalFunction) continue;
-    os << "  builder.addExport('" << PrintName(wire_bytes, exp.name) << "', "
+    os << "builder.addExport('" << PrintName(wire_bytes, exp.name) << "', "
        << exp.index << ");\n";
   }
 
   if (compiles) {
-    os << "  const instance = builder.instantiate();\n"
-          "  print(instance.exports.main(1, 2, 3));\n";
+    os << "const instance = builder.instantiate();\n"
+          "print(instance.exports.main(1, 2, 3));\n";
   } else {
-    os << "  assertThrows(function() { builder.instantiate(); }, "
+    os << "assertThrows(function() { builder.instantiate(); }, "
           "WebAssembly.CompileError);\n";
   }
-  os << "})();\n";
+  os << "\n";
 }
 
 void WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data,
@@ -265,6 +263,8 @@ void WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data,
   FlagScope<bool> enable_##feat(&FLAG_experimental_wasm_##feat, true);
   FOREACH_WASM_STAGING_FEATURE_FLAG(ENABLE_STAGED_FEATURES)
 #undef ENABLE_STAGED_FEATURES
+  // SIMD is not included in staging yet, so we enable it here for fuzzing.
+  EXPERIMENTAL_FLAG_SCOPE(simd);
 
   // Strictly enforce the input size limit. Note that setting "max_len" on the
   // fuzzer target is not enough, since different fuzzers are used and not all
diff --git a/deps/v8/test/fuzzer/wasm.cc b/deps/v8/test/fuzzer/wasm.cc
index 5c68030408..1230a7d46d 100644
--- a/deps/v8/test/fuzzer/wasm.cc
+++ b/deps/v8/test/fuzzer/wasm.cc
@@ -32,6 +32,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   // We reduce the maximum memory size and table size of WebAssembly instances
   // to avoid OOMs in the fuzzer.
   i::FlagScope<uint32_t> max_mem_flag_scope(&i::FLAG_wasm_max_mem_pages, 32);
+  i::FlagScope<uint32_t> max_mem_growth_flag_scope(
+      &i::FLAG_wasm_max_mem_pages_growth, 32);
   i::FlagScope<uint32_t> max_table_size_scope(&i::FLAG_wasm_max_table_size,
                                               100);
   v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
@@ -69,6 +71,6 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
 
   // Pump the message loop and run micro tasks, e.g. GC finalization tasks.
   support->PumpMessageLoop(v8::platform::MessageLoopBehavior::kDoNotWait);
-  isolate->RunMicrotasks();
+  isolate->PerformMicrotaskCheckpoint();
   return 0;
 }
diff --git a/deps/v8/test/inspector/cpu-profiler/console-profile-wasm-expected.txt b/deps/v8/test/inspector/cpu-profiler/console-profile-wasm-expected.txt
index ad1d9db168..c5b427f475 100644
--- a/deps/v8/test/inspector/cpu-profiler/console-profile-wasm-expected.txt
+++ b/deps/v8/test/inspector/cpu-profiler/console-profile-wasm-expected.txt
@@ -1,4 +1,4 @@
 Test that console profiles contain wasm function names.
 Compiling wasm.
 Running fib with increasing input until it shows up in the profile.
-Found fib in profile.
+Found expected functions in profile.
diff --git a/deps/v8/test/inspector/cpu-profiler/console-profile-wasm.js b/deps/v8/test/inspector/cpu-profiler/console-profile-wasm.js
index 0541ce02bb..dea818a351 100644
--- a/deps/v8/test/inspector/cpu-profiler/console-profile-wasm.js
+++ b/deps/v8/test/inspector/cpu-profiler/console-profile-wasm.js
@@ -2,13 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(v8:10266): Figure out why this fails on tsan with --always-opt.
+// Flags: --no-always-opt
+
 let {session, contextGroup, Protocol} = InspectorTest.start(
     'Test that console profiles contain wasm function names.');
 
 utils.load('test/mjsunit/wasm/wasm-module-builder.js');
 
-// Add fibonacci function.
+// Add fibonacci function, calling back and forth between JS and Wasm to also
+// check for the occurrence of the wrappers.
 var builder = new WasmModuleBuilder();
+const imp_index = builder.addImport('q', 'f', kSig_i_i);
 builder.addFunction('fib', kSig_i_i)
     .addBody([
       kExprLocalGet, 0,
@@ -17,9 +22,9 @@ builder.addFunction('fib', kSig_i_i)
       kExprI32LeS,  // i < 2 ?
       kExprBrIf, 0, // --> return i
       kExprI32Const, 1, kExprI32Sub,  // i - 1
-      kExprCallFunction, 0, // fib(i - 1)
+      kExprCallFunction, imp_index, // imp(i - 1)
       kExprLocalGet, 0, kExprI32Const, 2, kExprI32Sub,  // i - 2
-      kExprCallFunction, 0, // fib(i - 2)
+      kExprCallFunction, imp_index, // imp(i - 2)
       kExprI32Add
     ])
     .exportFunc();
@@ -32,28 +37,38 @@ function compile(bytes) {
     view[i] = bytes[i] | 0;
   }
   let module = new WebAssembly.Module(buffer);
-  let instance = new WebAssembly.Instance(module);
+  let fib = undefined;
+  function imp(i) { return fib(i); }
+  let instance = new WebAssembly.Instance(module, {q: {f: imp}});
+  fib = instance.exports.fib;
   return instance;
 }
 
-function checkError(message)
-{
-  if (message.error) {
-    InspectorTest.log("Error: ");
-    InspectorTest.logMessage(message);
-    InspectorTest.completeTest();
-  }
+function checkError(message) {
+  if (!message.error) return;
+  InspectorTest.log('Error: ');
+  InspectorTest.logMessage(message);
+  InspectorTest.completeTest();
 }
 
 (async function test() {
   Protocol.Profiler.enable();
   checkError(await Protocol.Profiler.start());
-  let found_fib_in_profile = false;
+  let found_good_profile = false;
   let finished_profiles = 0;
   Protocol.Profiler.onConsoleProfileFinished(e => {
     ++finished_profiles;
-    if (e.params.profile.nodes.some(n => n.callFrame.functionName === 'fib'))
-      found_fib_in_profile = true;
+    let function_names =
+        e.params.profile.nodes.map(n => n.callFrame.functionName);
+    // InspectorTest.log(function_names.join(', '));
+    // Check for at least one full cycle of
+    // fib -> wasm-to-js -> imp -> js-to-wasm -> fib.
+    const expected = ['fib', 'wasm-to-js:i:i', 'imp', 'js-to-wasm:i:i', 'fib'];
+    for (let i = 0; i <= function_names.length - expected.length; ++i) {
+      if (expected.every((val, idx) => val == function_names[i + idx])) {
+        found_good_profile = true;
+      }
+    }
   });
   InspectorTest.log('Compiling wasm.');
   checkError(await Protocol.Runtime.evaluate({
@@ -62,7 +77,7 @@ function checkError(message)
   }));
   InspectorTest.log(
       'Running fib with increasing input until it shows up in the profile.');
-  for (let i = 1; !found_fib_in_profile; ++i) {
+  for (let i = 1; !found_good_profile; ++i) {
     checkError(await Protocol.Runtime.evaluate(
         {expression: 'console.profile(\'profile\');'}));
     checkError(await Protocol.Runtime.evaluate(
@@ -75,6 +90,6 @@ function checkError(message)
           finished_profiles + ')');
     }
   }
-  InspectorTest.log('Found fib in profile.');
+  InspectorTest.log('Found expected functions in profile.');
   InspectorTest.completeTest();
 })().catch(e => InspectorTest.log('caught: ' + e));
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-empty-inner-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-empty-inner-expected.txt
new file mode 100644
index 0000000000..cb77ef1343
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-empty-inner-expected.txt
@@ -0,0 +1,4 @@
+Test empty inner classes with private instance methods in the outer class
+
+Running test: testScopesPaused
+undefined
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-empty-inner.js b/deps/v8/test/inspector/debugger/class-private-methods-empty-inner.js
new file mode 100644
index 0000000000..01ad459b8c
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-empty-inner.js
@@ -0,0 +1,44 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+let {session, contextGroup, Protocol} = InspectorTest.start(
+    'Test empty inner classes with private instance methods in the outer class');
+
+contextGroup.addScript(`
+function run() {
+  class Outer {
+    #method() {}
+
+    factory() {
+      return class Inner {
+        fn() {
+          debugger;
+        }
+      };
+    }
+  };
+
+  const a = new Outer();
+  const Inner = a.factory();
+  (new Inner).fn();
+}`);
+
+InspectorTest.runAsyncTestSuite([async function testScopesPaused() {
+  Protocol.Debugger.enable();
+  Protocol.Runtime.evaluate({expression: 'run()'});
+
+  let {params: {callFrames}} =
+      await Protocol.Debugger.oncePaused();  // inside fn()
+  let frame = callFrames[0];
+
+  let {result} =
+      await Protocol.Runtime.getProperties({objectId: frame.this.objectId});
+
+  InspectorTest.logObject(result.privateProperties);
+
+  Protocol.Debugger.resume();
+  Protocol.Debugger.disable();
+}]);
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-expected.txt
index d54076b6d5..19a944eebd 100644
--- a/deps/v8/test/inspector/debugger/class-private-methods-expected.txt
+++ b/deps/v8/test/inspector/debugger/class-private-methods-expected.txt
@@ -171,7 +171,7 @@ Evaluating private methods in the base class from the subclass
         columnNumber : 4
         exception : {
             className : SyntaxError
-            description : SyntaxError: Private field '#subclassMethod' must be declared in an enclosing class     at B.fn (<anonymous>:16:7)     at run (<anonymous>:30:5)     at <anonymous>:1:1
+            description : SyntaxError: Private field '#subclassMethod' must be declared in an enclosing class     at B.fn (<anonymous>:20:7)     at run (<anonymous>:34:5)     at <anonymous>:1:1
             objectId : <objectId>
             subtype : error
             type : object
@@ -183,7 +183,7 @@ Evaluating private methods in the base class from the subclass
     }
     result : {
         className : SyntaxError
-        description : SyntaxError: Private field '#subclassMethod' must be declared in an enclosing class     at B.fn (<anonymous>:16:7)     at run (<anonymous>:30:5)     at <anonymous>:1:1
+        description : SyntaxError: Private field '#subclassMethod' must be declared in an enclosing class     at B.fn (<anonymous>:20:7)     at run (<anonymous>:34:5)     at <anonymous>:1:1
         objectId : <objectId>
         subtype : error
         type : object
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-static-expected.txt
new file mode 100644
index 0000000000..c129a40cf6
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static-expected.txt
@@ -0,0 +1,148 @@
+Test static private class methods
+
+Running test: testScopesPaused
+privateProperties on the base class
+[
+    [0] : {
+        name : #writeOnly
+        set : {
+            className : Function
+            description : set #writeOnly(val) { this.#field = val; }
+            objectId : <objectId>
+            type : function
+        }
+    }
+    [1] : {
+        get : {
+            className : Function
+            description : get #readOnly() { return this.#field; }
+            objectId : <objectId>
+            type : function
+        }
+        name : #readOnly
+    }
+    [2] : {
+        get : {
+            className : Function
+            description : get #accessor() { return this.#field; }
+            objectId : <objectId>
+            type : function
+        }
+        name : #accessor
+        set : {
+            className : Function
+            description : set #accessor(val) { this.#field = val; }
+            objectId : <objectId>
+            type : function
+        }
+    }
+    [3] : {
+        name : #inc
+        value : {
+            className : Function
+            description : #inc() { return ++A.#accessor; }
+            objectId : <objectId>
+            type : function
+        }
+    }
+    [4] : {
+        name : #field
+        value : {
+            description : 2
+            type : number
+            value : 2
+        }
+    }
+]
+Evaluating A.#inc();
+{
+    result : {
+        description : 3
+        type : number
+        value : 3
+    }
+}
+Evaluating this.#inc();
+{
+    result : {
+        description : 4
+        type : number
+        value : 4
+    }
+}
+Evaluating ++this.#accessor;
+{
+    result : {
+        description : 5
+        type : number
+        value : 5
+    }
+}
+Evaluating this.#readOnly;
+{
+    result : {
+        description : 5
+        type : number
+        value : 5
+    }
+}
+Evaluating this.#writeOnly = 0; this.#field;
+{
+    result : {
+        description : 0
+        type : number
+        value : 0
+    }
+}
+privateProperties on the subclass
+[
+    [0] : {
+        get : {
+            className : Function
+            description : get #accessor() { return 'subclassAccessor'; }
+            objectId : <objectId>
+            type : function
+        }
+        name : #accessor
+    }
+    [1] : {
+        name : #subclassMethod
+        value : {
+            className : Function
+            description : #subclassMethod() { return B.#accessor; }
+            objectId : <objectId>
+            type : function
+        }
+    }
+]
+Evaluating this.#inc(); from the base class
+{
+    exceptionDetails : {
+        columnNumber : 4
+        exception : {
+            className : SyntaxError
+            description : SyntaxError: Private field '#inc' must be declared in an enclosing class     at Function.test (<anonymous>:24:7)     at run (<anonymous>:28:5)     at <anonymous>:1:1
+            objectId : <objectId>
+            subtype : error
+            type : object
+        }
+        exceptionId : <exceptionId>
+        lineNumber : 0
+        scriptId : <scriptId>
+        text : Uncaught
+    }
+    result : {
+        className : SyntaxError
+        description : SyntaxError: Private field '#inc' must be declared in an enclosing class     at Function.test (<anonymous>:24:7)     at run (<anonymous>:28:5)     at <anonymous>:1:1
+        objectId : <objectId>
+        subtype : error
+        type : object
+    }
+}
+Evaluating this.#subclassMethod();
+{
+    result : {
+        type : string
+        value : subclassAccessor
+    }
+}
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static-nested-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-static-nested-expected.txt
new file mode 100644
index 0000000000..7c9e6b2e1b
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static-nested-expected.txt
@@ -0,0 +1,17 @@
+Test static private class methods
+
+Running test: testScopesPaused
+privateProperties on class A
+[
+    [0] : {
+        name : #method
+        value : {
+            className : Function
+            description : #method() {       debugger;     }
+            objectId : {"injectedScriptId":1,"id":39}
+            type : function
+        }
+    }
+]
+privateProperties on class B
+undefined
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static-nested.js b/deps/v8/test/inspector/debugger/class-private-methods-static-nested.js
new file mode 100644
index 0000000000..b26fa13b84
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static-nested.js
@@ -0,0 +1,61 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+let { session, contextGroup, Protocol } = InspectorTest.start(
+  "Test static private class methods"
+);
+
+const script = `
+function run() {
+  class A {
+    static #method() {
+      debugger;
+    }
+    static test() {
+      class B {
+        static test() { debugger; }
+      }
+      A.#method();  // reference #method so it shows up
+      B.test();
+    }
+  }
+  A.test();
+}`;
+
+contextGroup.addScript(script);
+
+InspectorTest.runAsyncTestSuite([
+  async function testScopesPaused() {
+    Protocol.Debugger.enable();
+
+    // Do not await here, instead oncePaused should be awaited.
+    Protocol.Runtime.evaluate({ expression: 'run()' });
+
+    InspectorTest.log('privateProperties on class A');
+    let {
+      params: { callFrames }
+    } = await Protocol.Debugger.oncePaused(); // inside A.#method()
+
+    let frame = callFrames[0];
+    let { result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    });
+    InspectorTest.logObject(result.privateProperties);
+    Protocol.Debugger.resume();
+
+    ({ params: { callFrames } } = await Protocol.Debugger.oncePaused());  // B.test();
+    frame = callFrames[0];
+
+    InspectorTest.log('privateProperties on class B');
+    ({ result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    }));
+    InspectorTest.logObject(result.privateProperties);
+
+    Protocol.Debugger.resume();
+    Protocol.Debugger.disable();
+  }
+]);
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static-preview-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-static-preview-expected.txt
new file mode 100644
index 0000000000..96f7b01f23
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static-preview-expected.txt
@@ -0,0 +1,28 @@
+Check static private methods in object preview.
+
+Running test: testPrivateMethods
+expression: class { static get #readOnly() { return 1; } }
+{
+    type : string
+    value : class { static get #readOnly() { return 1; } }
+}
+expression: class { static set #writeOnly(val) { } }
+{
+    type : string
+    value : class { static set #writeOnly(val) { } }
+}
+expression: class { static #method() { return 1; } static get #accessor() { } static set #accessor(val) { } }
+{
+    type : string
+    value : class { static #method() { return 1; } static get #accessor() { } static set #accessor(val) { } }
+}
+expression: class extends class { } { static #method() { return 1; } }
+{
+    type : string
+    value : class extends class { } { static #method() { return 1; } }
+}
+expression: class extends class { static #method() { return 1; } } { get #accessor() { } set #accessor(val) { } }
+{
+    type : string
+    value : class extends class { static #method() { return 1; } } { get #accessor() { } set #accessor(val) { } }
+}
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static-preview.js b/deps/v8/test/inspector/debugger/class-private-methods-static-preview.js
new file mode 100644
index 0000000000..3a64ddec77
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static-preview.js
@@ -0,0 +1,41 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Flags: --harmony-private-methods
+
+let {session, contextGroup, Protocol} = InspectorTest.start("Check static private methods in object preview.");
+
+Protocol.Debugger.enable();
+Protocol.Runtime.enable();
+Protocol.Runtime.onConsoleAPICalled(dumpInternalProperties);
+
+contextGroup.setupInjectedScriptEnvironment();
+
+InspectorTest.runAsyncTestSuite([
+  async function testPrivateMethods() {
+    const expressions = [
+        "class { static get #readOnly() { return 1; } }",
+        "class { static set #writeOnly(val) { } }",
+        "class { static #method() { return 1; } static get #accessor() { } static set #accessor(val) { } }",
+        "class extends class { } { static #method() { return 1; } }",
+        "class extends class { static #method() { return 1; } } { get #accessor() { } set #accessor(val) { } }",
+    ];
+    for (const expression of expressions) {
+      InspectorTest.log(`expression: ${expression}`);
+      // Currently the previews are strings of the source code of the classes
+      await Protocol.Runtime.evaluate({
+        expression: `console.table(${expression})`,
+        generatePreview: true
+      });
+    }
+  }
+]);
+
+function dumpInternalProperties(message) {
+  try {
+    InspectorTest.logMessage(message.params.args[0]);
+  } catch {
+    InspectorTest.logMessage(message);
+  }
+}
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-static.js b/deps/v8/test/inspector/debugger/class-private-methods-static.js
new file mode 100644
index 0000000000..1d493116ef
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-static.js
@@ -0,0 +1,122 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+let { session, contextGroup, Protocol } = InspectorTest.start(
+  "Test static private class methods"
+);
+
+const script = `
+function run() {
+  class A {
+    static test() {
+      debugger;
+    }
+    static #field = 2;
+    #instanceMethod() { }  // should not show up
+    get #instanceAccessor() { return this.#field; }  // should not show up
+    set #instanceAccessor(val) { this.#field = val; }  // should not show up
+
+    static set #writeOnly(val) { this.#field = val; }
+    static get #readOnly() { return this.#field; }
+    static get #accessor() { return this.#field; }
+    static set #accessor(val) { this.#field = val; }
+    static #inc() { return ++A.#accessor; }
+  };
+  A.test();
+
+  class B extends A {
+    static get #accessor() { return 'subclassAccessor'; }
+    static #subclassMethod() { return B.#accessor; }
+    static test() {
+      debugger;
+    }
+  }
+
+  B.test();
+}`;
+
+contextGroup.addScript(script);
+
+InspectorTest.runAsyncTestSuite([
+  async function testScopesPaused() {
+    Protocol.Debugger.enable();
+
+    // Do not await here, instead oncePaused should be awaited.
+    Protocol.Runtime.evaluate({ expression: 'run()' });
+
+    InspectorTest.log('privateProperties on the base class');
+    let {
+      params: { callFrames }
+    } = await Protocol.Debugger.oncePaused(); // inside A.test()
+    let frame = callFrames[0];
+    let { result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    });
+    InspectorTest.logMessage(result.privateProperties);
+
+    InspectorTest.log('Evaluating A.#inc();');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'A.#inc();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    InspectorTest.log('Evaluating this.#inc();');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#inc();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    InspectorTest.log('Evaluating ++this.#accessor;');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: '++this.#accessor;',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    InspectorTest.log('Evaluating this.#readOnly;');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#readOnly;',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    InspectorTest.log('Evaluating this.#writeOnly = 0; this.#field;');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#writeOnly = 0; this.#field;',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    Protocol.Debugger.resume();
+    ({ params: { callFrames } } = await Protocol.Debugger.oncePaused());  // B.test();
+    frame = callFrames[0];
+
+    InspectorTest.log('privateProperties on the subclass');
+    ({ result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    }));
+    InspectorTest.logMessage(result.privateProperties);
+
+    InspectorTest.log('Evaluating this.#inc(); from the base class');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#inc();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logMessage(result);
+
+    InspectorTest.log('Evaluating this.#subclassMethod();');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#subclassMethod();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logMessage(result);
+
+    Protocol.Debugger.resume();
+    Protocol.Debugger.disable();
+  }
+]);
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-unused-expected.txt b/deps/v8/test/inspector/debugger/class-private-methods-unused-expected.txt
new file mode 100644
index 0000000000..4f33b3156e
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-unused-expected.txt
@@ -0,0 +1,83 @@
+Test accessing unused private methods at runtime
+
+Running test: testScopesPaused
+Get privateProperties of A in testStatic()
+[
+    [0] : {
+        name : #staticMethod
+        value : {
+            className : Function
+            description : #staticMethod() { return 1; }
+            objectId : {"injectedScriptId":1,"id":34}
+            type : function
+        }
+    }
+]
+Access A.#staticMethod() in testStatic()
+{
+    exceptionDetails : {
+        columnNumber : 0
+        exception : {
+            className : ReferenceError
+            description : ReferenceError: A is not defined     at eval (eval at testStatic (:1:1), <anonymous>:1:1)     at Function.testStatic (<anonymous>:6:29)     at run (<anonymous>:9:7)     at <anonymous>:1:1
+            objectId : {"injectedScriptId":1,"id":36}
+            subtype : error
+            type : object
+        }
+        exceptionId : 1
+        lineNumber : 0
+        scriptId : 5
+        text : Uncaught
+    }
+    result : {
+        className : ReferenceError
+        description : ReferenceError: A is not defined     at eval (eval at testStatic (:1:1), <anonymous>:1:1)     at Function.testStatic (<anonymous>:6:29)     at run (<anonymous>:9:7)     at <anonymous>:1:1
+        objectId : {"injectedScriptId":1,"id":35}
+        subtype : error
+        type : object
+    }
+}
+Access this.#staticMethod() in testStatic()
+{
+    exceptionDetails : {
+        columnNumber : 0
+        exception : {
+            className : Error
+            description : Error: Unused static private method '#staticMethod' cannot be accessed at debug time     at eval (eval at testStatic (:1:1), <anonymous>:1:1)     at Function.testStatic (<anonymous>:6:29)     at run (<anonymous>:9:7)     at <anonymous>:1:1
+            objectId : {"injectedScriptId":1,"id":38}
+            subtype : error
+            type : object
+        }
+        exceptionId : 2
+        lineNumber : 0
+        scriptId : 6
+        text : Uncaught
+    }
+    result : {
+        className : Error
+        description : Error: Unused static private method '#staticMethod' cannot be accessed at debug time     at eval (eval at testStatic (:1:1), <anonymous>:1:1)     at Function.testStatic (<anonymous>:6:29)     at run (<anonymous>:9:7)     at <anonymous>:1:1
+        objectId : {"injectedScriptId":1,"id":37}
+        subtype : error
+        type : object
+    }
+}
+get privateProperties of a in testInstance()
+[
+    [0] : {
+        name : #instanceMethod
+        value : {
+            className : Function
+            description : #instanceMethod() { return 2; }
+            objectId : {"injectedScriptId":1,"id":61}
+            type : function
+        }
+    }
+]
+Evaluating this.#instanceMethod() in testInstance()
+{
+    result : {
+        description : 2
+        type : number
+        value : 2
+    }
+}
diff --git a/deps/v8/test/inspector/debugger/class-private-methods-unused.js b/deps/v8/test/inspector/debugger/class-private-methods-unused.js
new file mode 100644
index 0000000000..a868735401
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/class-private-methods-unused.js
@@ -0,0 +1,79 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+let { session, contextGroup, Protocol } = InspectorTest.start(
+  "Test accessing unused private methods at runtime"
+);
+
+const script = `
+  function run() {
+    class A {
+      #instanceMethod() { return 2; }
+      static #staticMethod() { return 1; }
+      static testStatic() { debugger; }
+      testInstance() { debugger; }
+    };
+    A.testStatic();
+    const a = new A;
+    a.testInstance();
+  }`;
+
+contextGroup.addScript(script);
+
+InspectorTest.runAsyncTestSuite([
+  async function testScopesPaused() {
+    Protocol.Debugger.enable();
+
+    // Do not await here, instead oncePaused should be awaited.
+    Protocol.Runtime.evaluate({ expression: 'run()' });
+
+    InspectorTest.log('Get privateProperties of A in testStatic()');
+    let {
+      params: { callFrames }
+    } = await Protocol.Debugger.oncePaused(); // inside A.testStatic()
+    let frame = callFrames[0];
+    let { result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    });
+    InspectorTest.logObject(result.privateProperties);
+
+    // Variables not referenced in the source code are currently
+    // considered "optimized away".
+    InspectorTest.log('Access A.#staticMethod() in testStatic()');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'A.#staticMethod();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    InspectorTest.log('Access this.#staticMethod() in testStatic()');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#staticMethod();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    Protocol.Debugger.resume();
+    ({ params: { callFrames } } = await Protocol.Debugger.oncePaused());  // a.testInstatnce();
+    frame = callFrames[0];
+
+    InspectorTest.log('get privateProperties of a in testInstance()');
+    ({ result } = await Protocol.Runtime.getProperties({
+      objectId: frame.this.objectId
+    }));
+    InspectorTest.logObject(result.privateProperties);
+
+    InspectorTest.log('Evaluating this.#instanceMethod() in testInstance()');
+    ({ result } = await Protocol.Debugger.evaluateOnCallFrame({
+      expression: 'this.#instanceMethod();',
+      callFrameId: callFrames[0].callFrameId
+    }));
+    InspectorTest.logObject(result);
+
+    Protocol.Debugger.resume();
+    Protocol.Debugger.disable();
+  }
+]);
diff --git a/deps/v8/test/inspector/debugger/class-private-methods.js b/deps/v8/test/inspector/debugger/class-private-methods.js
index 7aa5f7a61f..f92916b254 100644
--- a/deps/v8/test/inspector/debugger/class-private-methods.js
+++ b/deps/v8/test/inspector/debugger/class-private-methods.js
@@ -13,6 +13,10 @@ function run() {
   class A {
     #field = 2;
 
+    static #staticMethod() {}  // should not show up
+    static get #staticAccessor() { }  // should not show up
+    static set #staticAccessor(val) { }  // should not show up
+
     #inc() { this.#field++; return this.#field; }
 
     set #writeOnly(val) { this.#field = val; }
diff --git a/deps/v8/test/inspector/debugger/es6-module-script-parsed-expected.txt b/deps/v8/test/inspector/debugger/es6-module-script-parsed-expected.txt
index b8d920692f..f91ce03b90 100644
--- a/deps/v8/test/inspector/debugger/es6-module-script-parsed-expected.txt
+++ b/deps/v8/test/inspector/debugger/es6-module-script-parsed-expected.txt
@@ -13,6 +13,7 @@ Running test: testLoadedModulesOnDebuggerEnable
         isModule : true
         length : 39
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -33,6 +34,7 @@ Running test: testScriptEventsWhenDebuggerIsEnabled
         isModule : true
         length : 39
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -50,6 +52,7 @@ Running test: testScriptEventsWhenDebuggerIsEnabled
         isModule : true
         length : 1
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
diff --git a/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error-expected.txt b/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error-expected.txt
index 22ef7aae92..374507cbea 100644
--- a/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error-expected.txt
+++ b/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error-expected.txt
@@ -1,40 +1,22 @@
 getPossibleBreakpoints should not crash during lazy compilation (crbug.com/715334)
 {
-    method : Debugger.scriptParsed
-    params : {
-        endColumn : 21
-        endLine : 2
-        executionContextId : <executionContextId>
-        hasSourceURL : true
-        hash : 124cb0278e3aa9f250651d433cdefeb5618c7202
-        isLiveEdit : false
-        isModule : false
-        length : 52
-        scriptId : <scriptId>
-        sourceMapURL : 
-        startColumn : 0
-        startLine : 0
-        url : test.js
-    }
-}
-{
     method : Debugger.scriptFailedToParse
     params : {
-        endColumn : 21
+        endColumn : 23
         endLine : 2
         executionContextId : <executionContextId>
         hasSourceURL : true
-        hash : 124cb0278e3aa9f250651d433cdefeb5618c7202
+        hash : 1bce5d0c4da4d13a3ea6e6f35ea0f34705c26ba4
         isModule : false
-        length : 52
+        length : 56
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
         url : test.js
     }
 }
-One script is reported twice
 {
     id : <messageId>
     result : {
diff --git a/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error.js b/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error.js
index d1326e967f..3ee7adf578 100644
--- a/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error.js
+++ b/deps/v8/test/inspector/debugger/get-possible-breakpoints-lazy-error.js
@@ -3,26 +3,16 @@
 // found in the LICENSE file.
 
 let {session, contextGroup, Protocol} = InspectorTest.start('getPossibleBreakpoints should not crash during lazy compilation (crbug.com/715334)');
-
-contextGroup.addScript(`
-function test() { continue; }
-//# sourceURL=test.js`);
-
-(async function test() {
-  Protocol.Debugger.enable();
-  let script = await Protocol.Debugger.onceScriptParsed();
-  InspectorTest.logMessage(script);
-  let scriptId = script.params.scriptId;
-  Protocol.Debugger.onScriptFailedToParse(msg => {
-    InspectorTest.logMessage(msg);
-    if (msg.params.scriptId !== script.params.scriptId) {
-      InspectorTest.log('Failed script to parse event has different scriptId');
-    } else {
-      InspectorTest.log('One script is reported twice');
-    }
-  });
-  let response = await Protocol.Debugger.getPossibleBreakpoints({
-    start: {scriptId, lineNumber: 0, columnNumber: 0}});
-  InspectorTest.logMessage(response);
-  InspectorTest.completeTest();
+  (async function test() {
+    Protocol.Debugger.enable();
+    Protocol.Debugger.onScriptFailedToParse(async msg => {
+      InspectorTest.logMessage(msg);
+      const response = await Protocol.Debugger.getPossibleBreakpoints({
+        start: {scriptId: msg.params.scriptId, lineNumber: 0, columnNumber: 0}});
+      InspectorTest.logMessage(response);
+      InspectorTest.completeTest();
+    });
+    contextGroup.addScript(`
+  function test() { continue; }
+  //# sourceURL=test.js`);
 })();
diff --git a/deps/v8/test/inspector/debugger/pause-on-oom-extrawide-expected.txt b/deps/v8/test/inspector/debugger/pause-on-oom-extrawide-expected.txt
new file mode 100644
index 0000000000..4ca988deca
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/pause-on-oom-extrawide-expected.txt
@@ -0,0 +1,2 @@
+Check pause on OOM
+reason: OOM
diff --git a/deps/v8/test/inspector/debugger/pause-on-oom-extrawide.js b/deps/v8/test/inspector/debugger/pause-on-oom-extrawide.js
new file mode 100644
index 0000000000..748ad2094e
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/pause-on-oom-extrawide.js
@@ -0,0 +1,39 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --max-old-space-size=16
+
+let { session, contextGroup, Protocol } = InspectorTest.start('Check pause on OOM');
+
+var script = `
+var arr = [];
+var stop = false;
+function generateGarbage() {
+  while(!stop) {`
+
+  // Force the JumpLoop to be ExtraWide.
+for (i = 0; i < 110; ++i) {
+  for (j = 0; j < 75; ++j) {
+    script += `arr.push(new Array(1000));`
+    script += `if (stop) { break; }`
+  }
+}
+
+script += `
+    }
+  }
+  //# sourceURL=test.js"`
+
+contextGroup.addScript(script, 10, 26);
+
+Protocol.Debugger.onPaused((message) => {
+  InspectorTest.log(`reason: ${message.params.reason}`);
+  Protocol.Debugger.evaluateOnCallFrame({
+    callFrameId: message.params.callFrames[0].callFrameId,
+    expression: 'arr = []; stop = true;'
+  }).then(() => Protocol.Debugger.resume());
+});
+Protocol.Debugger.enable();
+Protocol.Runtime.evaluate({ expression: 'generateGarbage()' })
+  .then(InspectorTest.completeTest);
diff --git a/deps/v8/test/inspector/debugger/pause-on-oom-wide-expected.txt b/deps/v8/test/inspector/debugger/pause-on-oom-wide-expected.txt
new file mode 100644
index 0000000000..4ca988deca
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/pause-on-oom-wide-expected.txt
@@ -0,0 +1,2 @@
+Check pause on OOM
+reason: OOM
diff --git a/deps/v8/test/inspector/debugger/pause-on-oom-wide.js b/deps/v8/test/inspector/debugger/pause-on-oom-wide.js
new file mode 100644
index 0000000000..56f3f6f0e4
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/pause-on-oom-wide.js
@@ -0,0 +1,37 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --max-old-space-size=16
+
+let { session, contextGroup, Protocol } = InspectorTest.start('Check pause on OOM');
+
+var script = `
+var arr = [];
+var stop = false;
+function generateGarbage() {
+  while(!stop) {`
+
+  // Force the JumpLoop to be Wide.
+for (i = 0; i < 37; ++i) {
+  script += `arr.push(new Array(1000));`
+  script += `if (stop) { break; }`
+}
+
+script += `
+    }
+  }
+  //# sourceURL=test.js"`
+
+contextGroup.addScript(script, 10, 26);
+
+Protocol.Debugger.onPaused((message) => {
+  InspectorTest.log(`reason: ${message.params.reason}`);
+  Protocol.Debugger.evaluateOnCallFrame({
+    callFrameId: message.params.callFrames[0].callFrameId,
+    expression: 'arr = []; stop = true;'
+  }).then(() => Protocol.Debugger.resume());
+});
+Protocol.Debugger.enable();
+Protocol.Runtime.evaluate({ expression: 'generateGarbage()' })
+  .then(InspectorTest.completeTest);
diff --git a/deps/v8/test/inspector/debugger/resource-name-to-url-expected.txt b/deps/v8/test/inspector/debugger/resource-name-to-url-expected.txt
index 6f18b7b3e3..a4ff85895e 100644
--- a/deps/v8/test/inspector/debugger/resource-name-to-url-expected.txt
+++ b/deps/v8/test/inspector/debugger/resource-name-to-url-expected.txt
@@ -12,6 +12,7 @@ Check script with url:
         isModule : false
         length : 16
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -31,6 +32,7 @@ Check script with sourceURL comment:
         isModule : false
         length : 37
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -49,6 +51,7 @@ Check script failed to parse:
         isModule : false
         length : 15
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -67,6 +70,7 @@ Check script failed to parse with sourceURL comment:
         isModule : false
         length : 36
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
diff --git a/deps/v8/test/inspector/debugger/script-on-after-compile-expected.txt b/deps/v8/test/inspector/debugger/script-on-after-compile-expected.txt
index 2079518424..789221a27f 100644
--- a/deps/v8/test/inspector/debugger/script-on-after-compile-expected.txt
+++ b/deps/v8/test/inspector/debugger/script-on-after-compile-expected.txt
@@ -13,6 +13,7 @@ scriptParsed
     isModule : false
     length : 42
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -32,6 +33,7 @@ scriptParsed
     isModule : false
     length : 52
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -51,6 +53,7 @@ scriptParsed
     isModule : false
     length : 43
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -70,6 +73,7 @@ scriptParsed
     isModule : false
     length : 46
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -89,6 +93,7 @@ scriptParsed
     isModule : false
     length : 50
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : oneline-map
     startColumn : 0
     startLine : 0
@@ -108,6 +113,7 @@ scriptParsed
     isModule : false
     length : 60
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : oneline-without-nl-map
     startColumn : 0
     startLine : 0
@@ -127,6 +133,7 @@ scriptParsed
     isModule : false
     length : 51
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : twoline-map
     startColumn : 0
     startLine : 0
@@ -146,6 +153,7 @@ scriptParsed
     isModule : false
     length : 54
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : threeline-map
     startColumn : 0
     startLine : 0
@@ -165,6 +173,7 @@ scriptParsed
     isModule : false
     length : 88
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : source-mapping-url-map
     startColumn : 0
     startLine : 0
@@ -184,6 +193,7 @@ scriptParsed
     isModule : false
     length : 89
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : source-mapping-url-map
     startColumn : 0
     startLine : 0
@@ -203,6 +213,7 @@ scriptParsed
     isModule : false
     length : 40
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -222,6 +233,7 @@ scriptParsed
     isModule : false
     length : 41
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -241,6 +253,7 @@ scriptParsed
     isModule : false
     length : 18
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -260,6 +273,7 @@ scriptParsed
     isModule : false
     length : 96
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -279,6 +293,7 @@ scriptParsed
     isModule : false
     length : 39
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -298,6 +313,7 @@ scriptParsed
     isModule : false
     length : 19
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -317,6 +333,7 @@ scriptParsed
     isModule : false
     length : 20
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -336,6 +353,7 @@ scriptParsed
     isModule : false
     length : 21
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -355,6 +373,7 @@ scriptParsed
     isModule : false
     length : 22
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -374,6 +393,7 @@ scriptParsed
     isModule : false
     length : 42
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -393,6 +413,7 @@ scriptParsed
     isModule : false
     length : 52
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -412,6 +433,7 @@ scriptParsed
     isModule : false
     length : 43
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -431,6 +453,7 @@ scriptParsed
     isModule : false
     length : 46
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -450,6 +473,7 @@ scriptParsed
     isModule : false
     length : 50
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : oneline-map
     startColumn : 0
     startLine : 0
@@ -469,6 +493,7 @@ scriptParsed
     isModule : false
     length : 60
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : oneline-without-nl-map
     startColumn : 0
     startLine : 0
@@ -488,6 +513,7 @@ scriptParsed
     isModule : false
     length : 51
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : twoline-map
     startColumn : 0
     startLine : 0
@@ -507,6 +533,7 @@ scriptParsed
     isModule : false
     length : 54
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : threeline-map
     startColumn : 0
     startLine : 0
@@ -526,6 +553,7 @@ scriptParsed
     isModule : false
     length : 88
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : source-mapping-url-map
     startColumn : 0
     startLine : 0
@@ -545,6 +573,7 @@ scriptParsed
     isModule : false
     length : 89
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : source-mapping-url-map
     startColumn : 0
     startLine : 0
@@ -564,6 +593,7 @@ scriptParsed
     isModule : false
     length : 40
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -583,6 +613,7 @@ scriptParsed
     isModule : false
     length : 41
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -602,6 +633,7 @@ scriptParsed
     isModule : false
     length : 18
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -621,6 +653,7 @@ scriptParsed
     isModule : false
     length : 96
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -640,6 +673,7 @@ scriptParsed
     isModule : false
     length : 39
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     stackTrace : {
         callFrames : [
@@ -669,6 +703,7 @@ scriptFailedToParse
     isModule : false
     length : 31
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -687,6 +722,7 @@ scriptFailedToParse
     isModule : false
     length : 56
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : failed-map
     startColumn : 0
     startLine : 0
@@ -706,6 +742,7 @@ scriptParsed
     isModule : false
     length : 19
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -725,6 +762,7 @@ scriptParsed
     isModule : false
     length : 20
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -744,6 +782,7 @@ scriptParsed
     isModule : false
     length : 21
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -763,6 +802,7 @@ scriptParsed
     isModule : false
     length : 22
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
diff --git a/deps/v8/test/inspector/debugger/script-origin-stack-expected.txt b/deps/v8/test/inspector/debugger/script-origin-stack-expected.txt
index 40c7c7d856..f03a2ee524 100644
--- a/deps/v8/test/inspector/debugger/script-origin-stack-expected.txt
+++ b/deps/v8/test/inspector/debugger/script-origin-stack-expected.txt
@@ -11,6 +11,7 @@ Debugger.scriptParsed.stackTrace should contain only one frame
         isModule : false
         length : 0
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         stackTrace : {
             callFrames : [
diff --git a/deps/v8/test/inspector/debugger/script-parsed-for-runtime-evaluate-expected.txt b/deps/v8/test/inspector/debugger/script-parsed-for-runtime-evaluate-expected.txt
index bec2c8354c..9fa4fd4f6f 100644
--- a/deps/v8/test/inspector/debugger/script-parsed-for-runtime-evaluate-expected.txt
+++ b/deps/v8/test/inspector/debugger/script-parsed-for-runtime-evaluate-expected.txt
@@ -12,6 +12,7 @@ Runtime.evaluate with valid expression
         isModule : false
         length : 29
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -30,6 +31,7 @@ Runtime.evaluate with syntax error
         isModule : false
         length : 39
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -49,6 +51,7 @@ Runtime.callFunctionOn with valid functionDeclaration
         isModule : false
         length : 18
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -67,6 +70,7 @@ Runtime.callFunctionOn with syntax error
         isModule : false
         length : 3
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -86,6 +90,7 @@ Runtime.compileScript with valid expression
         isModule : false
         length : 4
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -104,6 +109,7 @@ Runtime.compileScript with syntax error
         isModule : false
         length : 1
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -124,6 +130,7 @@ Runtime.evaluate compiled script with stack trace
         isModule : false
         length : 8
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -142,6 +149,7 @@ Runtime.evaluate compiled script with stack trace
         isModule : false
         length : 86
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         stackTrace : {
             callFrames : [
@@ -171,6 +179,7 @@ Runtime.evaluate compiled script with stack trace
         isModule : false
         length : 4
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         stackTrace : {
             callFrames : [
@@ -201,6 +210,7 @@ Runtime.evaluate compile script error with stack trace
         isModule : false
         length : 12
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -219,6 +229,7 @@ Runtime.evaluate compile script error with stack trace
         isModule : false
         length : 98
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         stackTrace : {
             callFrames : [
@@ -247,6 +258,7 @@ Runtime.evaluate compile script error with stack trace
         isModule : false
         length : 3
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         stackTrace : {
             callFrames : [
diff --git a/deps/v8/test/inspector/debugger/script-parsed-hash-expected.txt b/deps/v8/test/inspector/debugger/script-parsed-hash-expected.txt
index 2149d834f8..a4c012d368 100644
--- a/deps/v8/test/inspector/debugger/script-parsed-hash-expected.txt
+++ b/deps/v8/test/inspector/debugger/script-parsed-hash-expected.txt
@@ -9,6 +9,7 @@ Tests scripts hasing
     isModule : false
     length : 1
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -24,6 +25,7 @@ Tests scripts hasing
     isModule : false
     length : 3
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
@@ -39,6 +41,7 @@ Tests scripts hasing
     isModule : false
     length : 8106
     scriptId : <scriptId>
+    scriptLanguage : JavaScript
     sourceMapURL : 
     startColumn : 0
     startLine : 0
diff --git a/deps/v8/test/inspector/debugger/wasm-anyref-global-expected.txt b/deps/v8/test/inspector/debugger/wasm-anyref-global-expected.txt
index d7b67a93de..c0b889121b 100644
--- a/deps/v8/test/inspector/debugger/wasm-anyref-global-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-anyref-global-expected.txt
@@ -3,5 +3,5 @@ Waiting for wasm script to be parsed.
 Setting breakpoint in wasm.
 Running main.
 Paused in debugger.
-   globals: {"global#0": hello, world}
+   globals: {"m.global": hello, world}
 Finished.
diff --git a/deps/v8/test/inspector/debugger/wasm-clone-module-expected.txt b/deps/v8/test/inspector/debugger/wasm-clone-module-expected.txt
index b437d1b253..9b22d614e8 100644
--- a/deps/v8/test/inspector/debugger/wasm-clone-module-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-clone-module-expected.txt
@@ -1,5 +1,5 @@
 Tests that cloning a module notifies the debugger
-Got URL: wasm://wasm/95d1e44e
-Got URL: wasm://wasm/95d1e44e
-Got URL: wasm://wasm/95d1e44e
+Got URL: wasm://wasm/cae8f226
+Got URL: wasm://wasm/cae8f226
+Got URL: wasm://wasm/cae8f226
 Done!
diff --git a/deps/v8/test/inspector/debugger/wasm-debug-command-expected.txt b/deps/v8/test/inspector/debugger/wasm-debug-command-expected.txt
index eadcb7d671..cd4c9fbd4a 100644
--- a/deps/v8/test/inspector/debugger/wasm-debug-command-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-debug-command-expected.txt
@@ -3,9 +3,9 @@ Installing code and global variable.
 Calling instantiate function.
 Waiting for wasm scripts to be parsed.
 Ignoring script with url v8://test/callInstantiate
-Got wasm script: wasm://wasm/fa045c1e
+Got wasm script: wasm://wasm/7d022e0e
 paused No 1
-Script wasm://wasm/fa045c1e byte offset 35: Wasm opcode 0x20
+Script wasm://wasm/7d022e0e byte offset 35: Wasm opcode 0x20
 Debugger.resume
 exports.main returned!
 Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-get-breakable-locations-byte-offsets-expected.txt b/deps/v8/test/inspector/debugger/wasm-get-breakable-locations-byte-offsets-expected.txt
index a0ff4a04a9..7a970415a0 100644
--- a/deps/v8/test/inspector/debugger/wasm-get-breakable-locations-byte-offsets-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-get-breakable-locations-byte-offsets-expected.txt
@@ -2,82 +2,76 @@ Tests breakable locations in wasm
 Running testFunction...
 Script nr 0 parsed. URL: v8://test/setup
 Script nr 1 parsed. URL: v8://test/runTestFunction
-Script nr 2 parsed. URL: wasm://wasm/6a95b41e
+Script nr 2 parsed. URL: wasm://wasm/354ada0e
 This is a wasm script (nr 0).
 Querying breakable locations for all wasm scripts now...
 Requesting all breakable locations in wasm script 0
 Bytecode matches!
-11 breakable location(s):
+10 breakable location(s):
 [0] 0:40 || byte=1
 [1] 0:41 || byte=65
 [2] 0:43 || byte=33
 [3] 0:45 || byte=11
 [4] 0:48 || byte=32
 [5] 0:50 || byte=4
-[6] 0:52 || byte=2
-[7] 0:54 || byte=16
-[8] 0:56 || byte=11
-[9] 0:57 || byte=11
-[10] 0:58 || byte=11
+[6] 0:54 || byte=16
+[7] 0:56 || byte=11
+[8] 0:57 || byte=11
+[9] 0:58 || byte=11
 Requesting breakable locations in offsets [0,45)
 3 breakable location(s):
 [0] 0:40 || byte=1
 [1] 0:41 || byte=65
 [2] 0:43 || byte=33
 Requesting breakable locations in offsets [50,60)
-6 breakable location(s):
+5 breakable location(s):
 [0] 0:50 || byte=4
-[1] 0:52 || byte=2
-[2] 0:54 || byte=16
-[3] 0:56 || byte=11
-[4] 0:57 || byte=11
-[5] 0:58 || byte=11
+[1] 0:54 || byte=16
+[2] 0:56 || byte=11
+[3] 0:57 || byte=11
+[4] 0:58 || byte=11
 Setting a breakpoint on each breakable location...
-Setting at wasm://wasm/6a95b41e:0:40
+Setting at wasm://wasm/354ada0e:0:40
 Success!
-Setting at wasm://wasm/6a95b41e:0:41
+Setting at wasm://wasm/354ada0e:0:41
 Success!
-Setting at wasm://wasm/6a95b41e:0:43
+Setting at wasm://wasm/354ada0e:0:43
 Success!
-Setting at wasm://wasm/6a95b41e:0:45
+Setting at wasm://wasm/354ada0e:0:45
 Success!
-Setting at wasm://wasm/6a95b41e:0:48
+Setting at wasm://wasm/354ada0e:0:48
 Success!
-Setting at wasm://wasm/6a95b41e:0:50
+Setting at wasm://wasm/354ada0e:0:50
 Success!
-Setting at wasm://wasm/6a95b41e:0:52
+Setting at wasm://wasm/354ada0e:0:54
 Success!
-Setting at wasm://wasm/6a95b41e:0:54
+Setting at wasm://wasm/354ada0e:0:56
 Success!
-Setting at wasm://wasm/6a95b41e:0:56
+Setting at wasm://wasm/354ada0e:0:57
 Success!
-Setting at wasm://wasm/6a95b41e:0:57
-Success!
-Setting at wasm://wasm/6a95b41e:0:58
+Setting at wasm://wasm/354ada0e:0:58
 Success!
 Running wasm code...
-Missing breakpoints: 11
-Script nr 3 parsed. URL: v8://test/runWasm
-Stopped at wasm://wasm/6a95b41e:0:48
 Missing breakpoints: 10
-Stopped at wasm://wasm/6a95b41e:0:50
+Script nr 3 parsed. URL: v8://test/runWasm
+Stopped at wasm://wasm/354ada0e:0:48
 Missing breakpoints: 9
-Stopped at wasm://wasm/6a95b41e:0:52
+Stopped at wasm://wasm/354ada0e:0:50
 Missing breakpoints: 8
-Stopped at wasm://wasm/6a95b41e:0:54
+Stopped at wasm://wasm/354ada0e:0:54
 Missing breakpoints: 7
-Stopped at wasm://wasm/6a95b41e:0:40
+Stopped at wasm://wasm/354ada0e:0:40
 Missing breakpoints: 6
-Stopped at wasm://wasm/6a95b41e:0:41
+Stopped at wasm://wasm/354ada0e:0:41
 Missing breakpoints: 5
-Stopped at wasm://wasm/6a95b41e:0:43
+Stopped at wasm://wasm/354ada0e:0:43
 Missing breakpoints: 4
-Stopped at wasm://wasm/6a95b41e:0:45
+Stopped at wasm://wasm/354ada0e:0:45
 Missing breakpoints: 3
-Stopped at wasm://wasm/6a95b41e:0:56
+Stopped at wasm://wasm/354ada0e:0:56
 Missing breakpoints: 2
-Stopped at wasm://wasm/6a95b41e:0:57
+Stopped at wasm://wasm/354ada0e:0:57
 Missing breakpoints: 1
-Stopped at wasm://wasm/6a95b41e:0:58
+Stopped at wasm://wasm/354ada0e:0:58
 Missing breakpoints: 0
 Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-global-names-expected.txt b/deps/v8/test/inspector/debugger/wasm-global-names-expected.txt
new file mode 100644
index 0000000000..912dbc85e1
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-global-names-expected.txt
@@ -0,0 +1,7 @@
+Test wasm global names
+Waiting for wasm script to be parsed.
+Setting breakpoint in wasm.
+Running main.
+Paused in debugger.
+   globals: {"module_name.imported_global", "exported_global", "global2"}
+Finished.
diff --git a/deps/v8/test/inspector/debugger/wasm-global-names.js b/deps/v8/test/inspector/debugger/wasm-global-names.js
new file mode 100644
index 0000000000..22d0eb30ea
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-global-names.js
@@ -0,0 +1,82 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+let {session, contextGroup, Protocol} =
+    InspectorTest.start('Test wasm global names');
+
+utils.load('test/mjsunit/wasm/wasm-module-builder.js');
+
+let builder = new WasmModuleBuilder();
+builder.addImportedGlobal('module_name', 'imported_global', kWasmI32, false);
+let func = builder.addFunction('func', kSig_v_i)
+               .addBody([
+                 kExprGlobalGet, 0,  //
+                 kExprDrop,          //
+               ])
+               .exportAs('main');
+var o = builder.addGlobal(kWasmI32, func).exportAs('exported_global');
+builder.addGlobal(kWasmI32);  // global2
+let moduleBytes = JSON.stringify(builder.toArray());
+
+function test(moduleBytes) {
+  let module = new WebAssembly.Module((new Uint8Array(moduleBytes)).buffer);
+  let imported_global_value = 123;
+  instance = new WebAssembly.Instance(
+      module, {module_name: {imported_global: imported_global_value}});
+}
+
+(async function() {
+  try {
+    Protocol.Debugger.enable();
+    Protocol.Runtime.evaluate({
+      expression: `
+      let instance;
+      ${test.toString()}
+      test(${moduleBytes});`
+    });
+
+    InspectorTest.log('Waiting for wasm script to be parsed.');
+    let scriptId;
+    while (true) {
+      let msg = await Protocol.Debugger.onceScriptParsed();
+      if (msg.params.url.startsWith('wasm://')) {
+        scriptId = msg.params.scriptId;
+        break;
+      }
+    }
+
+    InspectorTest.log('Setting breakpoint in wasm.');
+    await Protocol.Debugger.setBreakpoint(
+        {location: {scriptId, lineNumber: 0, columnNumber: func.body_offset}});
+
+    InspectorTest.log('Running main.');
+    Protocol.Runtime.evaluate({expression: 'instance.exports.main()'});
+
+    let msg = await Protocol.Debugger.oncePaused();
+    let callFrames = msg.params.callFrames;
+    InspectorTest.log('Paused in debugger.');
+    let scopeChain = callFrames[0].scopeChain;
+    for (let scope of scopeChain) {
+      if (scope.type != 'global') continue;
+
+      let globalObjectProps = (await Protocol.Runtime.getProperties({
+                                'objectId': scope.object.objectId
+                              })).result.result;
+
+      for (let prop of globalObjectProps) {
+        let subProps = (await Protocol.Runtime.getProperties({
+                         objectId: prop.value.objectId
+                       })).result.result;
+        let values = subProps.map((value) => `"${value.name}"`).join(', ');
+        InspectorTest.log(`   ${prop.name}: {${values}}`);
+      }
+    }
+
+    InspectorTest.log('Finished.');
+  } catch (exc) {
+    InspectorTest.log(`Failed with exception: ${exc}.`);
+  } finally {
+    InspectorTest.completeTest();
+  }
+})();
diff --git a/deps/v8/test/inspector/debugger/wasm-imports-expected.txt b/deps/v8/test/inspector/debugger/wasm-imports-expected.txt
index eb6b119dc3..fffaba9017 100644
--- a/deps/v8/test/inspector/debugger/wasm-imports-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-imports-expected.txt
@@ -4,16 +4,16 @@ Calling instantiate function for module A.
 Waiting for wasm script to be parsed.
 Got wasm script!
 Setting breakpoint in line 1:
-Script wasm://wasm/1871020e byte offset 33: Wasm opcode 0x1
+Script wasm://wasm/8c388106 byte offset 33: Wasm opcode 0x01
 Calling instantiate function for module B.
 Calling main function on module B.
 Paused at 0:33.
-Script wasm://wasm/1871020e byte offset 33: Wasm opcode 0x1
+Script wasm://wasm/8c388106 byte offset 33: Wasm opcode 0x01
 Getting current stack trace via "new Error().stack".
 Error
     at v8://test/getStack:1:1
-    at func (wasm-function[0]:0x21)
-    at main (wasm-function[1]:0x2f)
+    at func (<anonymous>:wasm-function[0]:0x21)
+    at main (<anonymous>:wasm-function[1]:0x2f)
     at v8://test/runWasm:1:22
 exports.main returned.
 Finished.
diff --git a/deps/v8/test/inspector/debugger/wasm-inspect-many-registers-expected.txt b/deps/v8/test/inspector/debugger/wasm-inspect-many-registers-expected.txt
new file mode 100644
index 0000000000..04c48c92f6
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-inspect-many-registers-expected.txt
@@ -0,0 +1,103 @@
+Test inspecting register values in Liftoff.
+Installing instantiate function.
+Testing i32.
+Waiting for wasm script.
+Setting 20 breakpoints.
+Calling main.
+Paused at offset 48; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : []
+Paused at offset 50; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0]
+Paused at offset 52; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1]
+Paused at offset 54; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2]
+Paused at offset 56; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3]
+Paused at offset 58; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4]
+Paused at offset 60; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5]
+Paused at offset 62; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6]
+Paused at offset 64; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7]
+Paused at offset 66; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8]
+Paused at offset 68; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+Paused at offset 69; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 17]
+Paused at offset 70; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 24]
+Paused at offset 71; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 30]
+Paused at offset 72; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 35]
+Paused at offset 73; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 39]
+Paused at offset 74; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 42]
+Paused at offset 75; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 44]
+Paused at offset 76; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 45]
+Paused at offset 77; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [45]
+main returned.
+Testing i64.
+Waiting for wasm script.
+Setting 20 breakpoints.
+Calling main.
+Paused at offset 48; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : []
+Paused at offset 50; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0]
+Paused at offset 52; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1]
+Paused at offset 54; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2]
+Paused at offset 56; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3]
+Paused at offset 58; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4]
+Paused at offset 60; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5]
+Paused at offset 62; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6]
+Paused at offset 64; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7]
+Paused at offset 66; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8]
+Paused at offset 68; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+Paused at offset 69; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 17]
+Paused at offset 70; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 24]
+Paused at offset 71; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 30]
+Paused at offset 72; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 35]
+Paused at offset 73; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 39]
+Paused at offset 74; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 42]
+Paused at offset 75; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 44]
+Paused at offset 76; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 45]
+Paused at offset 77; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [45]
+main returned.
+Testing f32.
+Waiting for wasm script.
+Setting 20 breakpoints.
+Calling main.
+Paused at offset 48; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : []
+Paused at offset 50; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0]
+Paused at offset 52; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1]
+Paused at offset 54; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2]
+Paused at offset 56; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3]
+Paused at offset 58; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4]
+Paused at offset 60; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5]
+Paused at offset 62; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6]
+Paused at offset 64; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7]
+Paused at offset 66; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8]
+Paused at offset 68; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+Paused at offset 69; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 17]
+Paused at offset 70; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 24]
+Paused at offset 71; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 30]
+Paused at offset 72; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 35]
+Paused at offset 73; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 39]
+Paused at offset 74; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 42]
+Paused at offset 75; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 44]
+Paused at offset 76; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 45]
+Paused at offset 77; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [45]
+main returned.
+Testing f64.
+Waiting for wasm script.
+Setting 20 breakpoints.
+Calling main.
+Paused at offset 48; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : []
+Paused at offset 50; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0]
+Paused at offset 52; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1]
+Paused at offset 54; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2]
+Paused at offset 56; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3]
+Paused at offset 58; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4]
+Paused at offset 60; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5]
+Paused at offset 62; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6]
+Paused at offset 64; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7]
+Paused at offset 66; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8]
+Paused at offset 68; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+Paused at offset 69; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 7, 17]
+Paused at offset 70; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 6, 24]
+Paused at offset 71; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 5, 30]
+Paused at offset 72; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 4, 35]
+Paused at offset 73; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 3, 39]
+Paused at offset 74; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 2, 42]
+Paused at offset 75; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 1, 44]
+Paused at offset 76; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [0, 45]
+Paused at offset 77; locals : [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; stack : [45]
+main returned.
+Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-inspect-many-registers.js b/deps/v8/test/inspector/debugger/wasm-inspect-many-registers.js
new file mode 100644
index 0000000000..a8f8b65586
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-inspect-many-registers.js
@@ -0,0 +1,122 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --debug-in-liftoff
+
+const {session, contextGroup, Protocol} =
+    InspectorTest.start('Test inspecting register values in Liftoff.');
+
+utils.load('test/mjsunit/wasm/wasm-module-builder.js');
+
+const num_locals = 10;
+const configs = {
+  i32: {type: kWasmI32, add: kExprI32Add, from_i32: kExprNop},
+  i64: {type: kWasmI64, add: kExprI64Add, from_i32: kExprI64SConvertI32},
+  f32: {type: kWasmF32, add: kExprF32Add, from_i32: kExprF32SConvertI32},
+  f64: {type: kWasmF64, add: kExprF64Add, from_i32: kExprF64SConvertI32}
+};
+
+function instantiate(bytes) {
+  let buffer = new ArrayBuffer(bytes.length);
+  let view = new Uint8Array(buffer);
+  for (let i = 0; i < bytes.length; ++i) {
+    view[i] = bytes[i] | 0;
+  }
+
+  let module = new WebAssembly.Module(buffer);
+  return new WebAssembly.Instance(module);
+}
+
+const evalWithUrl = (code, url) => Protocol.Runtime.evaluate(
+    {'expression': code + '\n//# sourceURL=v8://test/' + url});
+
+Protocol.Debugger.onPaused(async msg => {
+  let loc = msg.params.callFrames[0].location;
+  let line = [`Paused at offset ${loc.columnNumber}`];
+  // Inspect only the top wasm frame.
+  var frame = msg.params.callFrames[0];
+  for (var scope of frame.scopeChain) {
+    if (scope.type != 'local') continue;
+    var scope_properties =
+        await Protocol.Runtime.getProperties({objectId: scope.object.objectId});
+    for (var value of scope_properties.result.result) {
+      let msg = await Protocol.Runtime.getProperties(
+          {objectId: value.value.objectId});
+      let str = msg.result.result.map(elem => elem.value.value).join(', ');
+      line.push(`${value.name} : [${str}]`);
+    }
+    InspectorTest.log(line.join('; '));
+  }
+
+  Protocol.Debugger.resume();
+});
+
+// Build a function which receives a lot of arguments. It loads them all and
+// adds them together.
+// In Liftoff, this will hold many values in registers at the break sites.
+function buildModuleBytes(config) {
+  const sig = makeSig(
+      new Array(num_locals).fill(configs[config].type), [configs[config].type]);
+  const body = [];
+  for (let i = 0; i < num_locals; ++i) body.push(kExprLocalGet, i);
+  for (let i = 0; i < num_locals - 1; ++i) body.push(configs[config].add);
+  body.push(kExprReturn);
+  const builder = new WasmModuleBuilder();
+  const test_func = builder.addFunction('test_' + config, sig).addBody(body);
+  const main_body = [];
+  for (let i = 0; i < num_locals; ++i)
+    main_body.push(kExprI32Const, i, configs[config].from_i32);
+  main_body.push(kExprCallFunction, test_func.index, kExprDrop);
+  const main =
+      builder.addFunction('main', kSig_v_v).addBody(main_body).exportAs('main');
+
+  const module_bytes = builder.toArray();
+
+  // Break at every {kExprLocalGet} and at every addition.
+  const interesting_opcodes = [kExprLocalGet, kExprReturn, configs[config].add];
+  const breakpoints = [];
+  for (let idx = 0; idx < body.length; ++idx) {
+    if (interesting_opcodes.find(elem => elem == body[idx])) {
+      breakpoints.push(test_func.body_offset + idx);
+    }
+  }
+
+  return [module_bytes, breakpoints];
+}
+
+async function testConfig(config) {
+  InspectorTest.log(`Testing ${config}.`);
+  const [module_bytes, breakpoints] = buildModuleBytes(config);
+  const instance_name = `instance_${config}`;
+  // Spawn asynchronously:
+  let instantiate_code = evalWithUrl(
+      `const ${instance_name} = instantiate(${JSON.stringify(module_bytes)});`,
+      'instantiate');
+  InspectorTest.log('Waiting for wasm script.');
+  const [, {params: wasm_script}] = await Protocol.Debugger.onceScriptParsed(2);
+  InspectorTest.log(`Setting ${breakpoints.length} breakpoints.`);
+  for (let offset of breakpoints) {
+    await Protocol.Debugger.setBreakpoint({
+      'location': {
+        'scriptId': wasm_script.scriptId,
+        'lineNumber': 0,
+        'columnNumber': offset
+      }
+    });
+  }
+  InspectorTest.log('Calling main.');
+  await evalWithUrl(`${instance_name}.exports.main()`, `run_${config}`);
+  InspectorTest.log('main returned.');
+}
+
+(async function test() {
+  await Protocol.Debugger.enable();
+  InspectorTest.log('Installing instantiate function.');
+  await evalWithUrl(instantiate, 'install_instantiate');
+  for (let config in configs) {
+    await testConfig(config);
+  }
+  InspectorTest.log('Finished!');
+  InspectorTest.completeTest();
+})();
diff --git a/deps/v8/test/inspector/debugger/wasm-remove-breakpoint-expected.txt b/deps/v8/test/inspector/debugger/wasm-remove-breakpoint-expected.txt
index 1554054e46..42e0535d22 100644
--- a/deps/v8/test/inspector/debugger/wasm-remove-breakpoint-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-remove-breakpoint-expected.txt
@@ -3,7 +3,7 @@ Installing code and global variable.
 Calling instantiate function.
 Waiting for wasm scripts to be parsed.
 Ignoring script with url v8://test/callInstantiate
-Got wasm script: wasm://wasm/fa045c1e
+Got wasm script: wasm://wasm/7d022e0e
 Setting breakpoint on line 3 of wasm function
 {
     columnNumber : 39
@@ -12,7 +12,7 @@ Setting breakpoint on line 3 of wasm function
 }
 BreakpointId: 4:0:39:6
 paused No 1
-Script wasm://wasm/fa045c1e byte offset 39: Wasm opcode 0x6b
+Script wasm://wasm/7d022e0e byte offset 39: Wasm opcode 0x6b
 Remove breakpoint with breakpointId: 4:0:39:6
 Debugger.resume
 exports.main returned!
diff --git a/deps/v8/test/inspector/debugger/wasm-scope-info-expected.txt b/deps/v8/test/inspector/debugger/wasm-scope-info-expected.txt
index 1ab0977e1f..45bff036b7 100644
--- a/deps/v8/test/inspector/debugger/wasm-scope-info-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-scope-info-expected.txt
@@ -9,290 +9,384 @@ Setting breakpoint on first instruction of second function
     scriptId : <scriptId>
 }
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 69: Wasm opcode 0x41
+Script wasm://wasm/d374ef0a byte offset 69: Wasm opcode 0x41
 Scope:
 at func (0:69):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 4 (number), "local#1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 4 (number), "var1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 71: Wasm opcode 0x21
+Script wasm://wasm/d374ef0a byte offset 71: Wasm opcode 0x21
 Scope:
 at func (0:71):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 4 (number), "local#1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 4 (number), "var1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: "0": 11 (number)
+ - scope (wasm-expression-stack):
+   0: 11 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 73: Wasm opcode 0x41
+Script wasm://wasm/d374ef0a byte offset 73: Wasm opcode 0x41
 Scope:
 at func (0:73):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 75: Wasm opcode 0x21
+Script wasm://wasm/d374ef0a byte offset 75: Wasm opcode 0x21
 Scope:
 at func (0:75):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 0 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: "0": 47 (number)
+ - scope (wasm-expression-stack):
+   0: 47 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 77: Wasm opcode 0x42
+Script wasm://wasm/d374ef0a byte offset 77: Wasm opcode 0x42
 Scope:
 at func (0:77):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 88: Wasm opcode 0x21
+Script wasm://wasm/d374ef0a byte offset 88: Wasm opcode 0x21
 Scope:
 at func (0:88):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": 0 (number), "unicode☼f64": 0 (number)
    stack: "0": 9223372036854775807 (string)
+ - scope (wasm-expression-stack):
+   0: 9223372036854775807 (string)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 90: Wasm opcode 0x42
+Script wasm://wasm/d374ef0a byte offset 90: Wasm opcode 0x42
 Scope:
 at func (0:90):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": 9223372036854775807 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": 9223372036854775807 (string), "unicode☼f64": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 101: Wasm opcode 0x21
+Script wasm://wasm/d374ef0a byte offset 101: Wasm opcode 0x21
 Scope:
 at func (0:101):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": 9223372036854775807 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": 9223372036854775807 (string), "unicode☼f64": 0 (number)
    stack: "0": -9223372036854775808 (string)
+ - scope (wasm-expression-stack):
+   0: -9223372036854775808 (string)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 103: Wasm opcode 0x41
+Script wasm://wasm/d374ef0a byte offset 103: Wasm opcode 0x41
 Scope:
 at func (0:103):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 105: Wasm opcode 0xb8
+Script wasm://wasm/d374ef0a byte offset 105: Wasm opcode 0xb8
 Scope:
 at func (0:105):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: "0": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 106: Wasm opcode 0x41
+Script wasm://wasm/d374ef0a byte offset 106: Wasm opcode 0x41
 Scope:
 at func (0:106):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: "0": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 108: Wasm opcode 0xb8
+Script wasm://wasm/d374ef0a byte offset 108: Wasm opcode 0xb8
 Scope:
 at func (0:108):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: "0": 1 (number), "1": 7 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+   1: 7 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 109: Wasm opcode 0xa3
+Script wasm://wasm/d374ef0a byte offset 109: Wasm opcode 0xa3
 Scope:
 at func (0:109):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: "0": 1 (number), "1": 7 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+   1: 7 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 110: Wasm opcode 0x21
+Script wasm://wasm/d374ef0a byte offset 110: Wasm opcode 0x21
 Scope:
 at func (0:110):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0 (number)
    stack: "0": 0.14285714285714285 (number)
+ - scope (wasm-expression-stack):
+   0: 0.14285714285714285 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 112: Wasm opcode 0x41
+Script wasm://wasm/d374ef0a byte offset 112: Wasm opcode 0x41
 Scope:
 at func (0:112):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 114: Wasm opcode 0x24
+Script wasm://wasm/d374ef0a byte offset 114: Wasm opcode 0x24
 Scope:
 at func (0:114):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
    stack: "0": 15 (number)
+ - scope (wasm-expression-stack):
+   0: 15 (number)
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/a6e9de16 byte offset 116: Wasm opcode 0xb
+Script wasm://wasm/d374ef0a byte offset 116: Wasm opcode 0x0b
 Scope:
 at func (0:116):
  - scope (global):
-   globals: "global#0": 15 (number)
+   globals: "global0": 15 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32Arg": 11 (number), "local#1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
+   locals: "0": 0 (number), "i32Arg": 11 (number), "var1": 47 (number), "i64_local": -9223372036854775808 (string), "unicode☼f64": 0.14285714285714285 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at call_func (0:58):
  - scope (global):
-   globals: "global#0": 15 (number)
+   globals: "global0": 15 (number)
  - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+ - scope (global):
+   -- skipped globals
+
+Paused:
+Script wasm://wasm/d374ef0a byte offset 60: Wasm opcode 0x0b
+Scope:
+at call_func (0:60):
+ - scope (global):
+   globals: "global0": 15 (number)
+ - scope (local):
+   locals: "var0": 4 (number), "var1": 7.199999809265137 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
diff --git a/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff-expected.txt b/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff-expected.txt
index 4d6139e425..292f0074a3 100644
--- a/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff-expected.txt
@@ -10,126 +10,233 @@ Setting breakpoint on line 2 (first instruction) of third function
     scriptId : <scriptId>
 }
 Paused:
-Script wasm://wasm/89d60696 byte offset 85: Wasm opcode 0x20
+Script wasm://wasm/c4eb034a byte offset 85: Wasm opcode 0x20
 Scope:
 at C (interpreted) (0:85):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
    locals: "i32_arg": 42 (number), "i32_local": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at B (liftoff) (0:76):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "local#5": 0 (number)
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
    stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
 at A (liftoff) (0:54):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "arg#0": 42 (number)
+   locals: "var0": 42 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/89d60696 byte offset 87: Wasm opcode 0x24
+Script wasm://wasm/c4eb034a byte offset 87: Wasm opcode 0x24
 Scope:
 at C (interpreted) (0:87):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
    locals: "i32_arg": 42 (number), "i32_local": 0 (number)
    stack: "0": 42 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
 at B (liftoff) (0:76):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "local#5": 0 (number)
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
    stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
 at A (liftoff) (0:54):
  - scope (global):
-   globals: "global#0": 0 (number)
+   globals: "global0": 0 (number)
  - scope (local):
-   locals: "arg#0": 42 (number)
+   locals: "var0": 42 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/89d60696 byte offset 89: Wasm opcode 0x41
+Script wasm://wasm/c4eb034a byte offset 89: Wasm opcode 0x41
 Scope:
 at C (interpreted) (0:89):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
    locals: "i32_arg": 42 (number), "i32_local": 0 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at B (liftoff) (0:76):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "local#5": 0 (number)
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
    stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
 at A (liftoff) (0:54):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "arg#0": 42 (number)
+   locals: "var0": 42 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/89d60696 byte offset 91: Wasm opcode 0x21
+Script wasm://wasm/c4eb034a byte offset 91: Wasm opcode 0x21
 Scope:
 at C (interpreted) (0:91):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
    locals: "i32_arg": 42 (number), "i32_local": 0 (number)
    stack: "0": 47 (number)
+ - scope (wasm-expression-stack):
+   0: 47 (number)
 at B (liftoff) (0:76):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "local#5": 0 (number)
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
    stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
 at A (liftoff) (0:54):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "arg#0": 42 (number)
+   locals: "var0": 42 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
 
 Paused:
-Script wasm://wasm/89d60696 byte offset 93: Wasm opcode 0xb
+Script wasm://wasm/c4eb034a byte offset 93: Wasm opcode 0x0b
 Scope:
 at C (interpreted) (0:93):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
    locals: "i32_arg": 42 (number), "i32_local": 47 (number)
    stack: 
+ - scope (wasm-expression-stack):
 at B (liftoff) (0:76):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "local#5": 0 (number)
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
    stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
 at A (liftoff) (0:54):
  - scope (global):
-   globals: "global#0": 42 (number)
+   globals: "global0": 42 (number)
  - scope (local):
-   locals: "arg#0": 42 (number)
+   locals: "var0": 42 (number)
    stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+ - scope (global):
+   -- skipped globals
+
+Paused:
+Script wasm://wasm/c4eb034a byte offset 78: Wasm opcode 0x1a
+Scope:
+at B (liftoff) (0:78):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
+   stack: "0": 42 (number), "1": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+   1: 3 (number)
+at A (liftoff) (0:54):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "var0": 42 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+ - scope (global):
+   -- skipped globals
+
+Paused:
+Script wasm://wasm/c4eb034a byte offset 79: Wasm opcode 0x1a
+Scope:
+at B (liftoff) (0:79):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
+   stack: "0": 42 (number)
+ - scope (wasm-expression-stack):
+   0: 42 (number)
+at A (liftoff) (0:54):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "var0": 42 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+ - scope (global):
+   -- skipped globals
+
+Paused:
+Script wasm://wasm/c4eb034a byte offset 80: Wasm opcode 0x0b
+Scope:
+at B (liftoff) (0:80):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "0": 0 (number), "i32_arg": 42 (number), "i32_local": 0 (number), "f32_local": 7.199999809265137 (number), "var5": 0 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at A (liftoff) (0:54):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "var0": 42 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+ - scope (global):
+   -- skipped globals
+
+Paused:
+Script wasm://wasm/c4eb034a byte offset 56: Wasm opcode 0x0b
+Scope:
+at A (liftoff) (0:56):
+ - scope (global):
+   globals: "global0": 42 (number)
+ - scope (local):
+   locals: "var0": 42 (number)
+   stack: 
+ - scope (wasm-expression-stack):
 at (anonymous) (0:17):
  - scope (global):
    -- skipped globals
diff --git a/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff.js b/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff.js
index a945d77626..ef7ec63b03 100644
--- a/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff.js
+++ b/deps/v8/test/inspector/debugger/wasm-scope-info-liftoff.js
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(clemensb): In the long term this test should also work without any
-// flags, once we tier down to Liftoff when the debugger is enabled.
-// Flags: --liftoff --no-wasm-tier-up
+// Flags: --debug-in-liftoff
 
 let {session, contextGroup, Protocol} = InspectorTest.start(
     'Test retrieving scope information from compiled Liftoff frames');
@@ -149,17 +147,15 @@ async function waitForWasmScripts() {
 }
 
 async function getScopeValues(value) {
-  if (value.type != 'object') {
-    InspectorTest.log('Expected object. Found:');
-    InspectorTest.logObject(value);
-    return;
+  if (value.type == 'object') {
+    let msg = await Protocol.Runtime.getProperties({objectId: value.objectId});
+    printIfFailure(msg);
+    const printProperty = function(elem) {
+      return `"${elem.name}": ${elem.value.value} (${elem.value.type})`;
+    }
+    return msg.result.result.map(printProperty).join(', ');
   }
-
-  let msg = await Protocol.Runtime.getProperties({objectId: value.objectId});
-  printIfFailure(msg);
-  let printProperty = elem => '"' + elem.name + '"' +
-      ': ' + elem.value.value + ' (' + elem.value.type + ')';
-  return msg.result.result.map(printProperty).join(', ');
+  return value.value + ' (' + value.type + ')';
 }
 
 async function dumpScopeProperties(message) {
diff --git a/deps/v8/test/inspector/debugger/wasm-scope-info.js b/deps/v8/test/inspector/debugger/wasm-scope-info.js
index 693fb00277..413aa69ce1 100644
--- a/deps/v8/test/inspector/debugger/wasm-scope-info.js
+++ b/deps/v8/test/inspector/debugger/wasm-scope-info.js
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Disable Liftoff to get deterministic (non-existing) scope information for
-// compiled frames.
-// Flags: --no-liftoff
+// Flags: --debug-in-liftoff
 
 let {session, contextGroup, Protocol} = InspectorTest.start(
     'Test retrieving scope information when pausing in wasm functions');
@@ -147,17 +145,15 @@ async function waitForWasmScripts() {
 }
 
 async function getScopeValues(value) {
-  if (value.type != 'object') {
-    InspectorTest.log('Expected object. Found:');
-    InspectorTest.logObject(value);
-    return;
+  if (value.type == 'object') {
+    let msg = await Protocol.Runtime.getProperties({objectId: value.objectId});
+    printIfFailure(msg);
+    const printProperty = function(elem) {
+      return `"${elem.name}": ${elem.value.value} (${elem.value.type})`;
+    }
+    return msg.result.result.map(printProperty).join(', ');
   }
-
-  let msg = await Protocol.Runtime.getProperties({objectId: value.objectId});
-  printIfFailure(msg);
-  let printProperty = elem => '"' + elem.name + '"' +
-      ': ' + elem.value.value + ' (' + elem.value.type + ')';
-  return msg.result.result.map(printProperty).join(', ');
+  return value.value + ' (' + value.type + ')';
 }
 
 async function dumpScopeProperties(message) {
diff --git a/deps/v8/test/inspector/debugger/wasm-scripts-expected.txt b/deps/v8/test/inspector/debugger/wasm-scripts-expected.txt
index 3918e210a3..7b76eab18b 100644
--- a/deps/v8/test/inspector/debugger/wasm-scripts-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-scripts-expected.txt
@@ -1,52 +1,52 @@
 Tests how wasm scripts are reported
 Check that each inspector gets a wasm script at module creation time.
-Session #1: Script #0 parsed. URL: wasm://wasm/f608ae1e. Source map URL:
-Session #2: Script #0 parsed. URL: wasm://wasm/f608ae1e. Source map URL:
-Session #1: Script #1 parsed. URL: wasm://wasm/74f86b7e. Source map URL: wasm://dwarf
-Session #2: Script #1 parsed. URL: wasm://wasm/74f86b7e. Source map URL: wasm://dwarf
-Session #1: Script #2 parsed. URL: wasm://wasm/3754e3fe. Source map URL: abc
-Session #2: Script #2 parsed. URL: wasm://wasm/3754e3fe. Source map URL: abc
-Session #1: Script #3 parsed. URL: wasm://wasm/2bd2e40e. Source map URL: abc
-Session #2: Script #3 parsed. URL: wasm://wasm/2bd2e40e. Source map URL: abc
-Session #1: Script #4 parsed. URL: wasm://wasm/f568e726. Source map URL: abc
-Session #2: Script #4 parsed. URL: wasm://wasm/f568e726. Source map URL: abc
-Session #1: Source for wasm://wasm/f608ae1e:
+Session #1: Script #0 parsed. URL: wasm://wasm/7b04570e. Source map URL: , module begin: 0, module end: 0, code offset: 34
+Session #2: Script #0 parsed. URL: wasm://wasm/7b04570e. Source map URL: , module begin: 0, module end: 0, code offset: 34
+Session #1: Script #1 parsed. URL: wasm://wasm/ba7c35be. Source map URL: wasm://dwarf, module begin: 0, module end: 0, code offset: 34
+Session #2: Script #1 parsed. URL: wasm://wasm/ba7c35be. Source map URL: wasm://dwarf, module begin: 0, module end: 0, code offset: 34
+Session #1: Script #2 parsed. URL: wasm://wasm/1baa71fe. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #2: Script #2 parsed. URL: wasm://wasm/1baa71fe. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #1: Script #3 parsed. URL: wasm://wasm/95e97206. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #2: Script #3 parsed. URL: wasm://wasm/95e97206. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #1: Script #4 parsed. URL: wasm://wasm/7ab47392. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #2: Script #4 parsed. URL: wasm://wasm/7ab47392. Source map URL: abc, module begin: 0, module end: 0, code offset: 34
+Session #1: Source for wasm://wasm/7b04570e:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #2: Source for wasm://wasm/f608ae1e:
+Session #2: Source for wasm://wasm/7b04570e:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #1: Source for wasm://wasm/74f86b7e:
+Session #1: Source for wasm://wasm/ba7c35be:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #2: Source for wasm://wasm/74f86b7e:
+Session #2: Source for wasm://wasm/ba7c35be:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #1: Source for wasm://wasm/3754e3fe:
+Session #1: Source for wasm://wasm/1baa71fe:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #2: Source for wasm://wasm/3754e3fe:
+Session #2: Source for wasm://wasm/1baa71fe:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #1: Source for wasm://wasm/2bd2e40e:
+Session #1: Source for wasm://wasm/95e97206:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #2: Source for wasm://wasm/2bd2e40e:
+Session #2: Source for wasm://wasm/95e97206:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #1: Source for wasm://wasm/f568e726:
+Session #1: Source for wasm://wasm/7ab47392:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
-Session #2: Source for wasm://wasm/f568e726:
+Session #2: Source for wasm://wasm/7ab47392:
 Raw: 00 61 73 6d 01 00 00 00 01 07 02 60 00 00 60 00 00 03 03 02 00 01 07 08 01 04 6d 61 69 6e 00 01 0a 0e 02 03 00 01 0b 08 00 02 40 41 02 1a 0b 0b 00 15 10 73 6f 75 72 63 65 4d 61 70 70 69 6e 67 55 52 4c 03 61 62 63 00 11 0b 2e 64 65 62 75 67 5f 69 6e 66 6f 01 02 03 04 05 00 1b 04 6e 61 6d 65 01 14 02 00 0b 6e 6f 70 46 75 6e 63 74 69 6f 6e 01 04 6d 61 69 6e
 Imports: []
 Exports: [main: function]
diff --git a/deps/v8/test/inspector/debugger/wasm-scripts-with-name-expected.txt b/deps/v8/test/inspector/debugger/wasm-scripts-with-name-expected.txt
index f655ff17e7..a5d8c16ad9 100644
--- a/deps/v8/test/inspector/debugger/wasm-scripts-with-name-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-scripts-with-name-expected.txt
@@ -1,7 +1,7 @@
 Tests how wasm scripts are reported with name
 Check that the inspector gets four wasm scripts at module creation time.
-Session #1: Script #0 parsed. URL: wasm://wasm/49a8663e.
-Session #1: Script #1 parsed. URL: wasm://wasm/moduleName-aea4a206.
-Session #1: Source for wasm://wasm/49a8663e:
+Session #1: Script #0 parsed. URL: wasm://wasm/a4d4331e.
+Session #1: Script #1 parsed. URL: wasm://wasm/moduleName-d7525102.
+Session #1: Source for wasm://wasm/a4d4331e:
 
-Session #1: Source for wasm://wasm/moduleName-aea4a206:
+Session #1: Source for wasm://wasm/moduleName-d7525102:
diff --git a/deps/v8/test/inspector/debugger/wasm-scripts.js b/deps/v8/test/inspector/debugger/wasm-scripts.js
index 6a342922a8..5ad5ff09de 100644
--- a/deps/v8/test/inspector/debugger/wasm-scripts.js
+++ b/deps/v8/test/inspector/debugger/wasm-scripts.js
@@ -85,9 +85,13 @@ function trackScripts(debuggerParams) {
   Protocol.Debugger.enable(debuggerParams);
   Protocol.Debugger.onScriptParsed(handleScriptParsed);
 
-  async function loadScript({url, scriptId, sourceMapURL}) {
-    InspectorTest.log(`Session #${sessionId}: Script #${scripts.length} parsed. URL: ${url}. Source map URL: ${sourceMapURL}`);
-    let {result: {scriptSource, bytecode}} = await Protocol.Debugger.getScriptSource({scriptId});
+  async function loadScript(
+      {url, scriptId, sourceMapURL, startColumn, endColumn, codeOffset}) {
+    InspectorTest.log(`Session #${sessionId}: Script #${
+        scripts.length} parsed. URL: ${url}. Source map URL: ${
+        sourceMapURL}, module begin: ${startColumn}, module end: ${endColumn}, code offset: ${codeOffset}`);
+    let {result: {scriptSource, bytecode}} =
+        await Protocol.Debugger.getScriptSource({scriptId});
     if (bytecode) {
       if (scriptSource) {
         InspectorTest.log('Unexpected scriptSource with bytecode: ');
diff --git a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-expected.txt b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-expected.txt
index b53a17610b..bb65e4f47d 100644
--- a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-expected.txt
@@ -1,12 +1,12 @@
 Tests stepping through wasm scripts.
 Instantiating.
 Waiting for wasm script (ignoring first non-wasm script).
-Setting breakpoint at offset 54 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 53 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 51 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 49 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 45 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 47 on script wasm://wasm/18214bfe
+Setting breakpoint at offset 54 on script wasm://wasm/0c10a5fe
+Setting breakpoint at offset 53 on script wasm://wasm/0c10a5fe
+Setting breakpoint at offset 51 on script wasm://wasm/0c10a5fe
+Setting breakpoint at offset 49 on script wasm://wasm/0c10a5fe
+Setting breakpoint at offset 45 on script wasm://wasm/0c10a5fe
+Setting breakpoint at offset 47 on script wasm://wasm/0c10a5fe
 Calling main(4)
 Breaking on byte offset 45
 Breaking on byte offset 47
diff --git a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff-expected.txt b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff-expected.txt
index 735fc49f44..43827fef3b 100644
--- a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff-expected.txt
@@ -1,12 +1,391 @@
 Tests stepping through wasm scripts.
 Instantiating.
 Waiting for wasm script (ignoring first non-wasm script).
-Setting breakpoint at offset 54 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 53 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 51 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 49 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 45 on script wasm://wasm/18214bfe
-Setting breakpoint at offset 47 on script wasm://wasm/18214bfe
+Setting breakpoint at offset 38 on script wasm://wasm/0c10a5fe
 Calling main(4)
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 38: Wasm opcode 0x01
+Scope:
+at wasm_A (0:38):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Setting breakpoint at offset 39 on script v8://test/runWasm
+Setting breakpoint at offset 61 on script v8://test/runWasm
+Setting breakpoint at offset 60 on script v8://test/runWasm
+Setting breakpoint at offset 54 on script v8://test/runWasm
+Setting breakpoint at offset 53 on script v8://test/runWasm
+Setting breakpoint at offset 51 on script v8://test/runWasm
+Setting breakpoint at offset 49 on script v8://test/runWasm
+Setting breakpoint at offset 45 on script v8://test/runWasm
+Setting breakpoint at offset 47 on script v8://test/runWasm
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 39: Wasm opcode 0x01
+Scope:
+at wasm_A (0:39):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 45: Wasm opcode 0x20
+Scope:
+at wasm_B (0:45):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 47: Wasm opcode 0x04
+Scope:
+at wasm_B (0:47):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: "0": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 3 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 49: Wasm opcode 0x20
+Scope:
+at wasm_B (0:49):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 51: Wasm opcode 0x41
+Scope:
+at wasm_B (0:51):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: "0": 3 (number)
+ - scope (wasm-expression-stack):
+   0: 3 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 53: Wasm opcode 0x6b
+Scope:
+at wasm_B (0:53):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: "0": 3 (number), "1": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 3 (number)
+   1: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 54: Wasm opcode 0x21
+Scope:
+at wasm_B (0:54):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 3 (number)
+   stack: "0": 2 (number)
+ - scope (wasm-expression-stack):
+   0: 2 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 38: Wasm opcode 0x01
+Scope:
+at wasm_A (0:38):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 39: Wasm opcode 0x01
+Scope:
+at wasm_A (0:39):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 45: Wasm opcode 0x20
+Scope:
+at wasm_B (0:45):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 47: Wasm opcode 0x04
+Scope:
+at wasm_B (0:47):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: "0": 2 (number)
+ - scope (wasm-expression-stack):
+   0: 2 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 49: Wasm opcode 0x20
+Scope:
+at wasm_B (0:49):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 51: Wasm opcode 0x41
+Scope:
+at wasm_B (0:51):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: "0": 2 (number)
+ - scope (wasm-expression-stack):
+   0: 2 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 53: Wasm opcode 0x6b
+Scope:
+at wasm_B (0:53):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: "0": 2 (number), "1": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 2 (number)
+   1: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 54: Wasm opcode 0x21
+Scope:
+at wasm_B (0:54):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 2 (number)
+   stack: "0": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 38: Wasm opcode 0x01
+Scope:
+at wasm_A (0:38):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 39: Wasm opcode 0x01
+Scope:
+at wasm_A (0:39):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 45: Wasm opcode 0x20
+Scope:
+at wasm_B (0:45):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 47: Wasm opcode 0x04
+Scope:
+at wasm_B (0:47):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: "0": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 49: Wasm opcode 0x20
+Scope:
+at wasm_B (0:49):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 51: Wasm opcode 0x41
+Scope:
+at wasm_B (0:51):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: "0": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 53: Wasm opcode 0x6b
+Scope:
+at wasm_B (0:53):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: "0": 1 (number), "1": 1 (number)
+ - scope (wasm-expression-stack):
+   0: 1 (number)
+   1: 1 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 54: Wasm opcode 0x21
+Scope:
+at wasm_B (0:54):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 1 (number)
+   stack: "0": 0 (number)
+ - scope (wasm-expression-stack):
+   0: 0 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 38: Wasm opcode 0x01
+Scope:
+at wasm_A (0:38):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 0 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 39: Wasm opcode 0x01
+Scope:
+at wasm_A (0:39):
+ - scope (global):
+ - scope (local):
+   stack: 
+ - scope (wasm-expression-stack):
+at wasm_B (0:56):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 0 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 45: Wasm opcode 0x20
+Scope:
+at wasm_B (0:45):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 0 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 47: Wasm opcode 0x04
+Scope:
+at wasm_B (0:47):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 0 (number)
+   stack: "0": 0 (number)
+ - scope (wasm-expression-stack):
+   0: 0 (number)
+at (anonymous) (0:17):
+   -- skipped
+Paused:
+Script wasm://wasm/0c10a5fe byte offset 61: Wasm opcode 0x0b
+Scope:
+at wasm_B (0:61):
+ - scope (global):
+ - scope (local):
+   locals: "var0": 0 (number)
+   stack: 
+ - scope (wasm-expression-stack):
+at (anonymous) (0:17):
+   -- skipped
 exports.main returned!
 Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff.js b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff.js
index ce70f91921..3e8d783af6 100644
--- a/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff.js
+++ b/deps/v8/test/inspector/debugger/wasm-set-breakpoint-liftoff.js
@@ -6,29 +6,30 @@
 
 const {session, contextGroup, Protocol} =
     InspectorTest.start('Tests stepping through wasm scripts.');
+session.setupScriptMap();
 
 utils.load('test/mjsunit/wasm/wasm-module-builder.js');
 
 const builder = new WasmModuleBuilder();
 
-const func_a_idx =
-    builder.addFunction('wasm_A', kSig_v_v).addBody([kExprNop, kExprNop]).index;
+const func_a =
+    builder.addFunction('wasm_A', kSig_v_v).addBody([kExprNop, kExprNop]);
 
 // wasm_B calls wasm_A <param0> times.
 const func_b = builder.addFunction('wasm_B', kSig_v_i)
     .addBody([
       // clang-format off
-      kExprLoop, kWasmStmt,               // while
-        kExprLocalGet, 0,                 // -
-        kExprIf, kWasmStmt,               // if <param0> != 0
-          kExprLocalGet, 0,               // -
-          kExprI32Const, 1,               // -
-          kExprI32Sub,                    // -
-          kExprLocalSet, 0,               // decrease <param0>
-          kExprCallFunction, func_a_idx,  // -
-          kExprBr, 1,                     // continue
-          kExprEnd,                       // -
-        kExprEnd,                         // break
+      kExprLoop, kWasmStmt,                // while
+        kExprLocalGet, 0,                  // -
+        kExprIf, kWasmStmt,                // if <param0> != 0
+          kExprLocalGet, 0,                // -
+          kExprI32Const, 1,                // -
+          kExprI32Sub,                     // -
+          kExprLocalSet, 0,                // decrease <param0>
+          kExprCallFunction, func_a.index, // -
+          kExprBr, 1,                      // continue
+          kExprEnd,                        // -
+        kExprEnd,                          // break
       // clang-format on
     ])
     .exportAs('main');
@@ -53,24 +54,68 @@ const evalWithUrl = (code, url) =>
         .evaluate({'expression': code + '\n//# sourceURL=v8://test/' + url})
         .then(getResult);
 
-function setBreakpoint(offset, script) {
+function setBreakpoint(offset, scriptId, scriptUrl) {
   InspectorTest.log(
-      'Setting breakpoint at offset ' + offset + ' on script ' + script.url);
+      'Setting breakpoint at offset ' + offset + ' on script ' + scriptUrl);
   return Protocol.Debugger
       .setBreakpoint(
-          {'location': {'scriptId': script.scriptId, 'lineNumber': 0, 'columnNumber': offset}})
+          {'location': {'scriptId': scriptId, 'lineNumber': 0, 'columnNumber': offset}})
       .then(getResult);
 }
 
-Protocol.Debugger.onPaused(pause_msg => {
-  let loc = pause_msg.params.callFrames[0].location;
-  if (loc.lineNumber != 0) {
-    InspectorTest.log('Unexpected line number: ' + loc.lineNumber);
+// Only set breakpoints during the first loop iteration.
+var first_iteration = true;
+
+Protocol.Debugger.onPaused(async msg => {
+  let loc = msg.params.callFrames[0].location;
+  InspectorTest.log('Paused:');
+  await session.logSourceLocation(loc);
+  InspectorTest.log('Scope:');
+  for (var frame of msg.params.callFrames) {
+    var functionName = frame.functionName || '(anonymous)';
+    var lineNumber = frame.location.lineNumber;
+    var columnNumber = frame.location.columnNumber;
+    InspectorTest.log(`at ${functionName} (${lineNumber}:${columnNumber}):`);
+    if (!/^wasm/.test(frame.url)) {
+      InspectorTest.log('   -- skipped');
+      continue;
+    }
+    for (var scope of frame.scopeChain) {
+      InspectorTest.logObject(' - scope (' + scope.type + '):');
+      var properties = await Protocol.Runtime.getProperties(
+          {'objectId': scope.object.objectId});
+      for (var value of properties.result.result) {
+        var value_str = await getScopeValues(value.value);
+        InspectorTest.log('   ' + value.name + ': ' + value_str);
+      }
+    }
+  }
+
+  if (first_iteration && loc.columnNumber == func_a.body_offset) {
+    // Check that setting breakpoints on active instances of A and B takes
+    // effect immediately.
+    setBreakpoint(func_a.body_offset + 1, loc.scriptId, frame.url);
+    // All of the following breakpoints are in reachable code, except offset 17.
+    for (offset of [18, 17, 11, 10, 8, 6, 2, 4]) {
+      setBreakpoint(func_b.body_offset + offset, loc.scriptId, frame.url);
+    }
+    first_iteration = false;
   }
-  InspectorTest.log('Breaking on byte offset ' + loc.columnNumber);
+
   Protocol.Debugger.resume();
 });
 
+async function getScopeValues(value) {
+  if (value.type == 'object') {
+    let msg = await Protocol.Runtime.getProperties({objectId: value.objectId});
+    const printProperty = function(elem) {
+      return `"${elem.name}": ${elem.value.value} (${elem.value.type})`;
+    }
+    return msg.result.result.map(printProperty).join(', ');
+  }
+  return value.value + ' (' + value.type + ')';
+}
+
 (async function test() {
   await Protocol.Debugger.enable();
   InspectorTest.log('Instantiating.');
@@ -82,9 +127,9 @@ Protocol.Debugger.onPaused(pause_msg => {
       'Waiting for wasm script (ignoring first non-wasm script).');
   // Ignore javascript and full module wasm script, get scripts for functions.
   const [, {params: wasm_script}] = await Protocol.Debugger.onceScriptParsed(2);
-  for (offset of [11, 10, 8, 6, 2, 4]) {
-    await setBreakpoint(func_b.body_offset + offset, wasm_script);
-  }
+  // Set a breakpoint in function A at offset 0. When the debugger hits this
+  // breakpoint, new ones will be added.
+  await setBreakpoint(func_a.body_offset, wasm_script.scriptId, wasm_script.url);
   InspectorTest.log('Calling main(4)');
   await evalWithUrl('instance.exports.main(4)', 'runWasm');
   InspectorTest.log('exports.main returned!');
diff --git a/deps/v8/test/inspector/debugger/wasm-stack-expected.txt b/deps/v8/test/inspector/debugger/wasm-stack-expected.txt
index 364a319b93..1ff78f3543 100644
--- a/deps/v8/test/inspector/debugger/wasm-stack-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-stack-expected.txt
@@ -12,8 +12,8 @@ Result of evaluate (string):
 Error: this is your stack trace:
     -- skipped --
     at call_debugger (<anonymous>:3:5)
-    at call_func (wasm-function[1]:0x37)
-    at main (wasm-function[2]:0x3e)
+    at call_func (<anonymous>:wasm-function[1]:0x37)
+    at main (<anonymous>:wasm-function[2]:0x3e)
     at testFunction (<anonymous>:15:20)
     at <anonymous>:1:1
 Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets-expected.txt b/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets-expected.txt
index 409e7cc002..54e567e65b 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets-expected.txt
@@ -1,297 +1,342 @@
 Tests stepping through wasm scripts by byte offsets
 Setting up global instance variable.
-Got wasm script: wasm://wasm/7dfc8356
-Setting breakpoint on offset 59 (should be propagated to 60, the offset of the call), url wasm://wasm/7dfc8356
+Got wasm script: wasm://wasm/befe41aa
+Setting breakpoint on offset 59 (should be propagated to 60, the offset of the call), url wasm://wasm/befe41aa
 {
     columnNumber : 60
     lineNumber : 0
     scriptId : <scriptId>
 }
-Paused at wasm://wasm/7dfc8356:0:60
+Script wasm://wasm/befe41aa byte offset 60: Wasm opcode 0x10
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {"0":1024}
+ - scope (wasm-expression-stack):
+   {"0":1024}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:39
+Script wasm://wasm/befe41aa byte offset 39: Wasm opcode 0x01
 at wasm_A (0:39):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOver called
-Paused at wasm://wasm/7dfc8356:0:40
+Script wasm://wasm/befe41aa byte offset 40: Wasm opcode 0x01
 at wasm_A (0:40):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/7dfc8356:0:62
+Script wasm://wasm/befe41aa byte offset 62: Wasm opcode 0x0c
 at wasm_B (0:62):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/7dfc8356:0:60
+Script wasm://wasm/befe41aa byte offset 60: Wasm opcode 0x10
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {"0":1024}
+ - scope (wasm-expression-stack):
+   {"0":1024}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOver called
-Paused at wasm://wasm/7dfc8356:0:62
+Script wasm://wasm/befe41aa byte offset 62: Wasm opcode 0x0c
 at wasm_B (0:62):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:44
-at wasm_B (0:44):
+Script wasm://wasm/befe41aa byte offset 46: Wasm opcode 0x20
+at wasm_B (0:46):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.resume called
-Paused at wasm://wasm/7dfc8356:0:60
+Script wasm://wasm/befe41aa byte offset 60: Wasm opcode 0x10
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1024}
+ - scope (wasm-expression-stack):
+   {"0":1024}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:39
+Script wasm://wasm/befe41aa byte offset 39: Wasm opcode 0x01
 at wasm_A (0:39):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/7dfc8356:0:62
+Script wasm://wasm/befe41aa byte offset 62: Wasm opcode 0x0c
 at wasm_B (0:62):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
-   stack: {}
-at (anonymous) (0:17):
- - scope (global):
-   -- skipped
-Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:44
-at wasm_B (0:44):
- - scope (global):
-   -- skipped
- - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:46
+Script wasm://wasm/befe41aa byte offset 46: Wasm opcode 0x20
 at wasm_B (0:46):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:48
+Script wasm://wasm/befe41aa byte offset 48: Wasm opcode 0x04
 at wasm_B (0:48):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1}
+ - scope (wasm-expression-stack):
+   {"0":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:50
+Script wasm://wasm/befe41aa byte offset 50: Wasm opcode 0x20
 at wasm_B (0:50):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:52
+Script wasm://wasm/befe41aa byte offset 52: Wasm opcode 0x41
 at wasm_B (0:52):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1}
+ - scope (wasm-expression-stack):
+   {"0":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:54
+Script wasm://wasm/befe41aa byte offset 54: Wasm opcode 0x6b
 at wasm_B (0:54):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1,"1":1}
+ - scope (wasm-expression-stack):
+   {"0":1,"1":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:55
+Script wasm://wasm/befe41aa byte offset 55: Wasm opcode 0x21
 at wasm_B (0:55):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":0}
+ - scope (wasm-expression-stack):
+   {"0":0}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:57
+Script wasm://wasm/befe41aa byte offset 57: Wasm opcode 0x41
 at wasm_B (0:57):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:60
+Script wasm://wasm/befe41aa byte offset 60: Wasm opcode 0x10
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {"0":1024}
+ - scope (wasm-expression-stack):
+   {"0":1024}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:39
+Script wasm://wasm/befe41aa byte offset 39: Wasm opcode 0x01
 at wasm_A (0:39):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:40
+Script wasm://wasm/befe41aa byte offset 40: Wasm opcode 0x01
 at wasm_A (0:40):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:41
+Script wasm://wasm/befe41aa byte offset 41: Wasm opcode 0x0b
 at wasm_A (0:41):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1024}
+   locals: {"var0":1024}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:60):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/7dfc8356:0:62
+Script wasm://wasm/befe41aa byte offset 62: Wasm opcode 0x0c
 at wasm_B (0:62):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets.js b/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets.js
index 738544d418..d3c1932973 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets.js
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-byte-offsets.js
@@ -4,6 +4,7 @@
 
 let {session, contextGroup, Protocol} =
     InspectorTest.start('Tests stepping through wasm scripts by byte offsets');
+session.setupScriptMap();
 
 utils.load('test/mjsunit/wasm/wasm-module-builder.js');
 
@@ -82,8 +83,8 @@ function instantiate(bytes) {
   await waitForPauseAndStep('resume');    // to next breakpoint (3rd iteration)
   await waitForPauseAndStep('stepInto');  // into wasm_A
   await waitForPauseAndStep('stepOut');   // out to wasm_B
-  // Now step 10 times, until we are in wasm_A again.
-  for (let i = 0; i < 10; ++i) await waitForPauseAndStep('stepInto');
+  // Now step 9 times, until we are in wasm_A again.
+  for (let i = 0; i < 9; ++i) await waitForPauseAndStep('stepInto');
   // 3 more times, back to wasm_B.
   for (let i = 0; i < 3; ++i) await waitForPauseAndStep('stepInto');
   // Then just resume.
@@ -95,9 +96,7 @@ function instantiate(bytes) {
 
 async function waitForPauseAndStep(stepAction) {
   const {params: {callFrames}} = await Protocol.Debugger.oncePaused();
-  const topFrame = callFrames[0];
-  InspectorTest.log(
-      `Paused at ${topFrame.url}:${topFrame.location.lineNumber}:${topFrame.location.columnNumber}`);
+  await session.logSourceLocation(callFrames[0].location);
   for (var frame of callFrames) {
     const functionName = frame.functionName || '(anonymous)';
     const lineNumber = frame.location.lineNumber;
@@ -114,9 +113,13 @@ async function waitForPauseAndStep(stepAction) {
             functionDeclaration: 'function() { return this; }',
             returnByValue: true
           });
-        if (value.locals)
-          InspectorTest.log(`   locals: ${JSON.stringify(value.locals)}`);
-        InspectorTest.log(`   stack: ${JSON.stringify(value.stack)}`);
+        if (scope.type === 'local') {
+          if (value.locals)
+            InspectorTest.log(`   locals: ${JSON.stringify(value.locals)}`);
+          InspectorTest.log(`   stack: ${JSON.stringify(value.stack)}`);
+        } else {
+          InspectorTest.log(`   ${JSON.stringify(value)}`);
+        }
       }
     }
   }
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js-expected.txt b/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js-expected.txt
index 422aa8b9f3..89d64b9513 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js-expected.txt
@@ -3,8 +3,8 @@ Installing code and global variable.
 Calling instantiate function.
 Waiting for wasm scripts to be parsed.
 Ignoring script with url v8://test/callInstantiate
-Got wasm script: wasm://wasm/fa045c1e
-Setting breakpoint on line 3 of wasm function
+Got wasm script: wasm://wasm/7d022e0e
+Setting breakpoint on i32.const
 {
     columnNumber : 37
     lineNumber : 0
@@ -23,10 +23,10 @@ paused
 
 Debugger.stepInto
 paused
-Script wasm://wasm/fa045c1e byte offset 35: Wasm opcode 0x20
+Script wasm://wasm/7d022e0e byte offset 35: Wasm opcode 0x20
 Debugger.resume
 paused
-Script wasm://wasm/fa045c1e byte offset 37: Wasm opcode 0x41
+Script wasm://wasm/7d022e0e byte offset 37: Wasm opcode 0x41
 Debugger.resume
 exports.main returned!
 Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js.js b/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js.js
index f8c0b9dbbb..510c1c0073 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js.js
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-in-from-js.js
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-let {session, contextGroup, Protocol} = InspectorTest.start('Tests stepping from javascript into wasm');
+let {session, contextGroup, Protocol} =
+    InspectorTest.start('Tests stepping from javascript into wasm');
 session.setupScriptMap();
 
 utils.load('test/mjsunit/wasm/wasm-module-builder.js');
@@ -11,14 +12,12 @@ let builder = new WasmModuleBuilder();
 
 // wasm_A
 let func = builder.addFunction('wasm_A', kSig_i_i)
-    .addBody([
-      // clang-format off
-      kExprLocalGet, 0,              // Line 1: get input
-      kExprI32Const, 1,              // Line 2: get constant 1
-      kExprI32Sub                    // Line 3: decrease
-      // clang-format on
-    ])
-    .exportAs('main');
+               .addBody([
+                 kExprLocalGet, 0,  // push param 0
+                 kExprI32Const, 1,  // push constant 1
+                 kExprI32Sub        // subtract
+               ])
+               .exportAs('main');
 
 let module_bytes = builder.toArray();
 
@@ -38,7 +37,7 @@ let evalWithUrl = (code, url) => Protocol.Runtime.evaluate(
     {'expression': code + '\n//# sourceURL=v8://test/' + url});
 
 Protocol.Debugger.onPaused(async message => {
-  InspectorTest.log("paused");
+  InspectorTest.log('paused');
   var frames = message.params.callFrames;
   await session.logSourceLocation(frames[0].location);
   let action = step_actions.shift() || 'resume';
@@ -50,8 +49,7 @@ let step_actions = [
   'stepInto',  // # debugger
   'stepInto',  // step into instance.exports.main(1)
   'resume',    // move to breakpoint
-  // then just resume.
-  'resume',
+  'resume',    // then just resume.
 ];
 
 contextGroup.addScript(`
@@ -69,13 +67,17 @@ function test() {
   evalWithUrl(
       'instantiate(' + JSON.stringify(module_bytes) + ')', 'callInstantiate');
   const scriptId = await waitForWasmScript();
-  InspectorTest.log(
-      'Setting breakpoint on line 3 of wasm function');
-  let msg = await Protocol.Debugger.setBreakpoint(
-      {'location': {'scriptId': scriptId, 'lineNumber': 0, 'columnNumber': 2 + func.body_offset}});
+  InspectorTest.log('Setting breakpoint on i32.const');
+  let msg = await Protocol.Debugger.setBreakpoint({
+    'location': {
+      'scriptId': scriptId,
+      'lineNumber': 0,
+      'columnNumber': 2 + func.body_offset
+    }
+  });
   printFailure(msg);
   InspectorTest.logMessage(msg.result.actualLocation);
-  await Protocol.Runtime.evaluate({ expression: 'test()' });
+  await Protocol.Runtime.evaluate({expression: 'test()'});
   InspectorTest.log('exports.main returned!');
   InspectorTest.log('Finished!');
   InspectorTest.completeTest();
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-liftoff-expected.txt b/deps/v8/test/inspector/debugger/wasm-stepping-liftoff-expected.txt
new file mode 100644
index 0000000000..2f4194cd53
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-liftoff-expected.txt
@@ -0,0 +1,69 @@
+Tests stepping through wasm scripts by byte offsets
+Setting up global instance variable.
+Got wasm script: wasm://wasm/42af3c82
+Setting breakpoint on offset 72 (should be propagated to 73, the offset of the call), url wasm://wasm/42af3c82
+{
+    columnNumber : 73
+    lineNumber : 0
+    scriptId : <scriptId>
+}
+Script wasm://wasm/42af3c82 byte offset 73: Wasm opcode 0x10
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 52: Wasm opcode 0x01
+Debugger.stepOver called
+Script wasm://wasm/42af3c82 byte offset 53: Wasm opcode 0x01
+Debugger.stepOut called
+Script wasm://wasm/42af3c82 byte offset 75: Wasm opcode 0x0c
+Debugger.stepOut called
+Script wasm://wasm/42af3c82 byte offset 73: Wasm opcode 0x10
+Debugger.stepOver called
+Script wasm://wasm/42af3c82 byte offset 75: Wasm opcode 0x0c
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 59: Wasm opcode 0x20
+Debugger.resume called
+Script wasm://wasm/42af3c82 byte offset 73: Wasm opcode 0x10
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 52: Wasm opcode 0x01
+Debugger.stepOut called
+Script wasm://wasm/42af3c82 byte offset 75: Wasm opcode 0x0c
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 59: Wasm opcode 0x20
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 61: Wasm opcode 0x04
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 63: Wasm opcode 0x20
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 65: Wasm opcode 0x41
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 67: Wasm opcode 0x6b
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 68: Wasm opcode 0x21
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 70: Wasm opcode 0x41
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 73: Wasm opcode 0x10
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 52: Wasm opcode 0x01
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 53: Wasm opcode 0x01
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 54: Wasm opcode 0x0b
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 75: Wasm opcode 0x0c
+Debugger.stepInto called
+Script wasm://wasm/42af3c82 byte offset 59: Wasm opcode 0x20
+Debugger.resume called
+exports.main returned!
+Test stepping over a recursive call
+Setting breakpoint on the recursive call instruction @+93, url wasm://wasm/42af3c82
+{
+    columnNumber : 93
+    lineNumber : 0
+    scriptId : <scriptId>
+}
+Script wasm://wasm/42af3c82 byte offset 93: Wasm opcode 0x10
+Removing breakpoint
+Debugger.stepOver called
+Script wasm://wasm/42af3c82 byte offset 95: Wasm opcode 0x20
+Debugger.resume called
+Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-liftoff.js b/deps/v8/test/inspector/debugger/wasm-stepping-liftoff.js
new file mode 100644
index 0000000000..78c65e01f1
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-liftoff.js
@@ -0,0 +1,146 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --debug-in-liftoff
+
+let {session, contextGroup, Protocol} =
+    InspectorTest.start('Tests stepping through wasm scripts by byte offsets');
+session.setupScriptMap();
+
+utils.load('test/mjsunit/wasm/wasm-module-builder.js');
+
+var builder = new WasmModuleBuilder();
+
+var func_a_idx =
+    builder.addFunction('wasm_A', kSig_v_i).addBody([kExprNop, kExprNop]).index;
+
+// wasm_B calls wasm_A <param0> times.
+var func_b = builder.addFunction('wasm_B', kSig_v_i)
+    .addBody([
+      // clang-format off
+      kExprLoop, kWasmStmt,               // while
+        kExprLocalGet, 0,                 // -
+        kExprIf, kWasmStmt,               // if <param0> != 0
+          kExprLocalGet, 0,               // -
+          kExprI32Const, 1,               // -
+          kExprI32Sub,                    // -
+          kExprLocalSet, 0,               // decrease <param0>
+          ...wasmI32Const(1024),          // some longer i32 const (2 byte imm)
+          kExprCallFunction, func_a_idx,  // -
+          kExprBr, 1,                     // continue
+          kExprEnd,                       // -
+        kExprEnd,                         // break
+      // clang-format on
+    ])
+    .exportAs('main');
+
+let fact = builder.addFunction('fact', kSig_i_i)
+    .addLocals({i32_count: 1})
+    .addBody([
+    // clang-format off
+    kExprLocalGet, 0,
+    kExprIf, kWasmI32,               // if <param0> != 0
+      kExprLocalGet, 0,
+      kExprI32Const, 1,
+      kExprI32Sub,
+      kExprCallFunction, 2,
+      kExprLocalGet, 0,
+      kExprI32Mul,                   //   return fact(<param0> - 1) * <param0>
+    kExprElse,                       // else
+      kExprI32Const, 1,              //   return 1
+    kExprEnd,
+    // clang-format on
+  ])
+  .exportAs('fact');
+
+var module_bytes = builder.toArray();
+
+function instantiate(bytes) {
+  var buffer = new ArrayBuffer(bytes.length);
+  var view = new Uint8Array(buffer);
+  for (var i = 0; i < bytes.length; ++i) {
+    view[i] = bytes[i] | 0;
+  }
+
+  var module = new WebAssembly.Module(buffer);
+  // Set global variable.
+  instance = new WebAssembly.Instance(module);
+}
+
+(async function test() {
+  for (const action of ['stepInto', 'stepOver', 'stepOut', 'resume'])
+    InspectorTest.logProtocolCommandCalls('Debugger.' + action);
+
+  await Protocol.Debugger.enable();
+  InspectorTest.log('Setting up global instance variable.');
+  Protocol.Runtime.evaluate({
+    expression: `var instance;` +
+        `(${instantiate.toString()})(${JSON.stringify(module_bytes)})`
+  });
+  const [, {params: wasmScript}] = await Protocol.Debugger.onceScriptParsed(2);
+
+  InspectorTest.log('Got wasm script: ' + wasmScript.url);
+
+  // Set the breakpoint on a non-breakable position. This should resolve to the
+  // next instruction.
+  var offset = func_b.body_offset + 15;
+  InspectorTest.log(
+      `Setting breakpoint on offset ` + offset + ` (should be propagated to ` +
+        (offset + 1) + `, the offset of the call), url ${wasmScript.url}`);
+  let bpmsg = await Protocol.Debugger.setBreakpoint({
+    location: {scriptId: wasmScript.scriptId, lineNumber: 0, columnNumber: offset}
+  });
+
+  InspectorTest.logMessage(bpmsg.result.actualLocation);
+  Protocol.Runtime.evaluate({ expression: 'instance.exports.main(4)' });
+  await waitForPauseAndStep('stepInto');  // into call to wasm_A
+  await waitForPauseAndStep('stepOver');  // over first nop
+  await waitForPauseAndStep('stepOut');   // out of wasm_A
+  await waitForPauseAndStep('stepOut');   // out of wasm_B, stop on breakpoint
+  await waitForPauseAndStep('stepOver');  // over call
+  await waitForPauseAndStep('stepInto');  // == stepOver br
+  await waitForPauseAndStep('resume');    // to next breakpoint (3rd iteration)
+  await waitForPauseAndStep('stepInto');  // into wasm_A
+  await waitForPauseAndStep('stepOut');   // out to wasm_B
+  // Now step 10 times, until we are in wasm_A again.
+  for (let i = 0; i < 10; ++i) await waitForPauseAndStep('stepInto');
+  // 3 more times, back to wasm_B.
+  for (let i = 0; i < 3; ++i) await waitForPauseAndStep('stepInto');
+  // Then just resume.
+  await waitForPauseAndStep('resume');
+  InspectorTest.log('exports.main returned!');
+
+  InspectorTest.log('Test stepping over a recursive call');
+  // Set a breakpoint at the recursive call and run.
+  offset = fact.body_offset + 9; // Offset of the recursive call instruction.
+  InspectorTest.log(
+      `Setting breakpoint on the recursive call instruction @+` + offset +
+      `, url ${wasmScript.url}`);
+  bpmsg = await Protocol.Debugger.setBreakpoint({
+    location: {scriptId: wasmScript.scriptId, lineNumber: 0, columnNumber: offset}
+  });
+  actualLocation = bpmsg.result.actualLocation;
+  InspectorTest.logMessage(actualLocation);
+  Protocol.Runtime.evaluate({ expression: 'instance.exports.fact(4)' });
+  await waitForPause();
+
+  // Remove the breakpoint before stepping over.
+  InspectorTest.log('Removing breakpoint');
+  let breakpointId = bpmsg.result.breakpointId;
+  await Protocol.Debugger.removeBreakpoint({breakpointId});
+  await Protocol.Debugger.stepOver();
+  await waitForPauseAndStep('resume');
+  InspectorTest.log('Finished!');
+})().catch(reason => InspectorTest.log(`Failed: ${reason}`))
+    .finally(InspectorTest.completeTest);
+
+async function waitForPauseAndStep(stepAction) {
+  await waitForPause();
+  Protocol.Debugger[stepAction]();
+}
+
+async function waitForPause() {
+  const {params: {callFrames}} = await Protocol.Debugger.oncePaused();
+  await session.logSourceLocation(callFrames[0].location);
+}
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-to-js-expected.txt b/deps/v8/test/inspector/debugger/wasm-stepping-to-js-expected.txt
index 962456cabf..29ea23e14e 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-to-js-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-to-js-expected.txt
@@ -3,7 +3,7 @@ Installing code and global variable.
 Calling instantiate function.
 Waiting for wasm scripts to be parsed.
 Ignoring script with url v8://test/callInstantiate
-Got wasm script: wasm://wasm/485e942e
+Got wasm script: wasm://wasm/242f4a16
 Setting breakpoint at start of wasm function
 {
     columnNumber : 33
@@ -18,7 +18,7 @@ function test() {
 
 Debugger.resume
 paused
-Script wasm://wasm/485e942e byte offset 33: Wasm opcode 0x1
+Script wasm://wasm/242f4a16 byte offset 33: Wasm opcode 0x01
 Debugger.stepOut
 paused
   instance.exports.main();
@@ -37,10 +37,10 @@ function test() {
 
 Debugger.resume
 paused
-Script wasm://wasm/485e942e byte offset 33: Wasm opcode 0x1
+Script wasm://wasm/242f4a16 byte offset 33: Wasm opcode 0x01
 Debugger.stepOver
 paused
-Script wasm://wasm/485e942e byte offset 34: Wasm opcode 0xb
+Script wasm://wasm/242f4a16 byte offset 34: Wasm opcode 0x0b
 Debugger.resume
 exports.main returned!
 Finished run 2!
@@ -53,10 +53,11 @@ function test() {
 
 Debugger.resume
 paused
-Script wasm://wasm/485e942e byte offset 33: Wasm opcode 0x1
+Script wasm://wasm/242f4a16 byte offset 33: Wasm opcode 0x01
 Debugger.stepInto
 paused
-Script wasm://wasm/485e942e byte offset 34: Wasm opcode 0xb
+Script wasm://wasm/242f4a16 byte offset 34: Wasm opcode 0x0b
 Debugger.resume
 exports.main returned!
 Finished run 3!
+
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map-expected.txt b/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map-expected.txt
index 7d4f3a71ed..6e4f8ffc6a 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map-expected.txt
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map-expected.txt
@@ -1,305 +1,352 @@
 Tests stepping through wasm scripts with source maps
 Installing code an global variable and instantiate.
-Got wasm script: wasm://wasm/3697f0fe
+Got wasm script: wasm://wasm/9b4bf87e
 Script sourceMapURL: abc
-Requesting source for wasm://wasm/3697f0fe...
+Requesting source for wasm://wasm/9b4bf87e...
 Source retrieved without error: true
-Setting breakpoint on offset 54 (on the setlocal before the call), url wasm://wasm/3697f0fe
+Setting breakpoint on offset 54 (on the setlocal before the call), url wasm://wasm/9b4bf87e
 {
     columnNumber : 54
     lineNumber : 0
     scriptId : <scriptId>
 }
-Paused at wasm://wasm/3697f0fe:0:54
+Script wasm://wasm/9b4bf87e byte offset 54: Wasm opcode 0x21
 at wasm_B (0:54):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":4}
+   locals: {"var0":4}
    stack: {"0":3}
+ - scope (wasm-expression-stack):
+   {"0":3}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:56
+Script wasm://wasm/9b4bf87e byte offset 56: Wasm opcode 0x10
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:38
+Script wasm://wasm/9b4bf87e byte offset 38: Wasm opcode 0x01
 at wasm_A (0:38):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOver called
-Paused at wasm://wasm/3697f0fe:0:39
+Script wasm://wasm/9b4bf87e byte offset 39: Wasm opcode 0x01
 at wasm_A (0:39):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/3697f0fe:0:58
+Script wasm://wasm/9b4bf87e byte offset 58: Wasm opcode 0x0c
 at wasm_B (0:58):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/3697f0fe:0:54
+Script wasm://wasm/9b4bf87e byte offset 54: Wasm opcode 0x21
 at wasm_B (0:54):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":3}
+   locals: {"var0":3}
    stack: {"0":2}
+ - scope (wasm-expression-stack):
+   {"0":2}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOver called
-Paused at wasm://wasm/3697f0fe:0:56
+Script wasm://wasm/9b4bf87e byte offset 56: Wasm opcode 0x10
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOver called
-Paused at wasm://wasm/3697f0fe:0:58
+Script wasm://wasm/9b4bf87e byte offset 58: Wasm opcode 0x0c
 at wasm_B (0:58):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.resume called
-Paused at wasm://wasm/3697f0fe:0:54
+Script wasm://wasm/9b4bf87e byte offset 54: Wasm opcode 0x21
 at wasm_B (0:54):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":2}
+   locals: {"var0":2}
    stack: {"0":1}
+ - scope (wasm-expression-stack):
+   {"0":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:56
+Script wasm://wasm/9b4bf87e byte offset 56: Wasm opcode 0x10
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:38
+Script wasm://wasm/9b4bf87e byte offset 38: Wasm opcode 0x01
 at wasm_A (0:38):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepOut called
-Paused at wasm://wasm/3697f0fe:0:58
+Script wasm://wasm/9b4bf87e byte offset 58: Wasm opcode 0x0c
 at wasm_B (0:58):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:43
-at wasm_B (0:43):
- - scope (global):
-   -- skipped
- - scope (local):
-   locals: {"arg#0":1}
-   stack: {}
-at (anonymous) (0:17):
- - scope (global):
-   -- skipped
-Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:45
+Script wasm://wasm/9b4bf87e byte offset 45: Wasm opcode 0x20
 at wasm_B (0:45):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:47
+Script wasm://wasm/9b4bf87e byte offset 47: Wasm opcode 0x04
 at wasm_B (0:47):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1}
+ - scope (wasm-expression-stack):
+   {"0":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:49
+Script wasm://wasm/9b4bf87e byte offset 49: Wasm opcode 0x20
 at wasm_B (0:49):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:51
+Script wasm://wasm/9b4bf87e byte offset 51: Wasm opcode 0x41
 at wasm_B (0:51):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1}
+ - scope (wasm-expression-stack):
+   {"0":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:53
+Script wasm://wasm/9b4bf87e byte offset 53: Wasm opcode 0x6b
 at wasm_B (0:53):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":1,"1":1}
+ - scope (wasm-expression-stack):
+   {"0":1,"1":1}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:54
+Script wasm://wasm/9b4bf87e byte offset 54: Wasm opcode 0x21
 at wasm_B (0:54):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":1}
+   locals: {"var0":1}
    stack: {"0":0}
+ - scope (wasm-expression-stack):
+   {"0":0}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:56
+Script wasm://wasm/9b4bf87e byte offset 56: Wasm opcode 0x10
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:38
+Script wasm://wasm/9b4bf87e byte offset 38: Wasm opcode 0x01
 at wasm_A (0:38):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:39
+Script wasm://wasm/9b4bf87e byte offset 39: Wasm opcode 0x01
 at wasm_A (0:39):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:40
+Script wasm://wasm/9b4bf87e byte offset 40: Wasm opcode 0x0b
 at wasm_A (0:40):
  - scope (global):
    -- skipped
  - scope (local):
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at wasm_B (0:56):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
 Debugger.stepInto called
-Paused at wasm://wasm/3697f0fe:0:58
+Script wasm://wasm/9b4bf87e byte offset 58: Wasm opcode 0x0c
 at wasm_B (0:58):
  - scope (global):
    -- skipped
  - scope (local):
-   locals: {"arg#0":0}
+   locals: {"var0":0}
    stack: {}
+ - scope (wasm-expression-stack):
+   {}
 at (anonymous) (0:17):
  - scope (global):
    -- skipped
diff --git a/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map.js b/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map.js
index 57b2fd581c..17b1d05153 100644
--- a/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map.js
+++ b/deps/v8/test/inspector/debugger/wasm-stepping-with-source-map.js
@@ -4,6 +4,7 @@
 
 let {session, contextGroup, Protocol} =
     InspectorTest.start('Tests stepping through wasm scripts with source maps');
+session.setupScriptMap();
 
 utils.load('test/mjsunit/wasm/wasm-module-builder.js');
 
@@ -80,8 +81,8 @@ function instantiate(bytes) {
   await waitForPauseAndStep('stepInto');  // to call
   await waitForPauseAndStep('stepInto');  // into wasm_A
   await waitForPauseAndStep('stepOut');   // out to wasm_B
-  // now step 9 times, until we are in wasm_A again.
-  for (let i = 0; i < 9; ++i) await waitForPauseAndStep('stepInto');
+  // Now step 8 times, until we are in wasm_A again.
+  for (let i = 0; i < 8; ++i) await waitForPauseAndStep('stepInto');
   // 3 more times, back to wasm_B.
   for (let i = 0; i < 3; ++i) await waitForPauseAndStep('stepInto');
   // then just resume.
@@ -93,9 +94,7 @@ function instantiate(bytes) {
 
 async function waitForPauseAndStep(stepAction) {
   const {params: {callFrames}} = await Protocol.Debugger.oncePaused();
-  const topFrame = callFrames[0];
-  InspectorTest.log(
-      `Paused at ${topFrame.url}:${topFrame.location.lineNumber}:${topFrame.location.columnNumber}`);
+  await session.logSourceLocation(callFrames[0].location);
   for (var frame of callFrames) {
     const functionName = frame.functionName || '(anonymous)';
     const lineNumber = frame.location.lineNumber;
@@ -112,9 +111,14 @@ async function waitForPauseAndStep(stepAction) {
               functionDeclaration: 'function() { return this; }',
               returnByValue: true
             });
-        if (value.locals)
-          InspectorTest.log(`   locals: ${JSON.stringify(value.locals)}`);
-        InspectorTest.log(`   stack: ${JSON.stringify(value.stack)}`);
+
+        if (scope.type === 'local') {
+          if (value.locals)
+            InspectorTest.log(`   locals: ${JSON.stringify(value.locals)}`);
+          InspectorTest.log(`   stack: ${JSON.stringify(value.stack)}`);
+        } else {
+          InspectorTest.log(`   ${JSON.stringify(value)}`);
+        }
       }
     }
   }
diff --git a/deps/v8/test/inspector/debugger/wasm-unnamed-function-names-expected.txt b/deps/v8/test/inspector/debugger/wasm-unnamed-function-names-expected.txt
new file mode 100644
index 0000000000..d7819588a5
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-unnamed-function-names-expected.txt
@@ -0,0 +1,10 @@
+Tests unnamed function in wasm scripts
+Running testFunction with generated wasm bytes...
+Paused on 'debugger;'
+Number of frames: 5
+  - [0] call_debugger
+  - [1] func1
+  - [2] main
+  - [3] testFunction
+  - [4] 
+Finished!
diff --git a/deps/v8/test/inspector/debugger/wasm-unnamed-function-names.js b/deps/v8/test/inspector/debugger/wasm-unnamed-function-names.js
new file mode 100644
index 0000000000..fae8d66abc
--- /dev/null
+++ b/deps/v8/test/inspector/debugger/wasm-unnamed-function-names.js
@@ -0,0 +1,69 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+let {session, contextGroup, Protocol} =
+    InspectorTest.start('Tests unnamed function in wasm scripts');
+
+utils.load('test/mjsunit/wasm/wasm-module-builder.js');
+
+var builder = new WasmModuleBuilder();
+
+var imported_idx = builder.addImport('mode', 'import_func', kSig_v_v);
+
+// Unnamed non export function.
+var function_idx = builder.addFunction(undefined, kSig_v_v)
+                       .addBody([kExprCallFunction, imported_idx])
+                       .index;
+
+// Unnamed export function.
+builder.addFunction(undefined, kSig_v_v)
+    .addBody([kExprCallFunction, function_idx])
+    .exportAs('main');
+
+var module_bytes = builder.toArray();
+
+function testFunction(bytes) {
+  function call_debugger() {
+    debugger;
+  }
+
+  var buffer = new ArrayBuffer(bytes.length);
+  var view = new Uint8Array(buffer);
+  for (var i = 0; i < bytes.length; i++) {
+    view[i] = bytes[i] | 0;
+  }
+
+  var module = new WebAssembly.Module(buffer);
+  var instance =
+      new WebAssembly.Instance(module, {mode: {import_func: call_debugger}});
+
+  instance.exports.main();
+}
+
+contextGroup.addScript(testFunction.toString());
+
+(async function test() {
+  await Protocol.Debugger.enable();
+  Protocol.Debugger.onPaused(handleDebuggerPaused);
+  InspectorTest.log('Running testFunction with generated wasm bytes...');
+  await Protocol.Runtime.evaluate(
+      {'expression': 'testFunction(' + JSON.stringify(module_bytes) + ')'});
+
+  InspectorTest.log('Finished!');
+  InspectorTest.completeTest();
+})();
+
+function logStackTrace(messageObject) {
+  var frames = messageObject.params.callFrames;
+  InspectorTest.log('Number of frames: ' + frames.length);
+  for (var i = 0; i < frames.length; ++i) {
+    InspectorTest.log('  - [' + i + '] ' + frames[i].functionName);
+  }
+}
+
+function handleDebuggerPaused(messageObject) {
+  InspectorTest.log('Paused on \'debugger;\'');
+  logStackTrace(messageObject);
+  Protocol.Debugger.resume();
+}
diff --git a/deps/v8/test/inspector/inspector-test.cc b/deps/v8/test/inspector/inspector-test.cc
index 075744a40e..4837f3caea 100644
--- a/deps/v8/test/inspector/inspector-test.cc
+++ b/deps/v8/test/inspector/inspector-test.cc
@@ -70,8 +70,7 @@ std::vector<uint8_t> ToBytes(v8::Isolate* isolate, v8::Local<v8::String> str) {
 }
 
 v8::Local<v8::String> ToV8String(v8::Isolate* isolate, const char* str) {
-  return v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(isolate, str).ToLocalChecked();
 }
 
 v8::Local<v8::String> ToV8String(v8::Isolate* isolate,
diff --git a/deps/v8/test/inspector/inspector.status b/deps/v8/test/inspector/inspector.status
index 0b6d8abda2..ba06c9df3c 100644
--- a/deps/v8/test/inspector/inspector.status
+++ b/deps/v8/test/inspector/inspector.status
@@ -17,6 +17,14 @@
 }],  # ALWAYS
 
 ##############################################################################
+['variant == future', {
+  # https://crbug.com/v8/10356
+  # This test worked in the wasm interpreter, but fails when using Liftoff for
+  # debugging.
+  'debugger/wasm-anyref-global': [FAIL],
+}],
+
+##############################################################################
 ['system == android', {
   # https://crbug.com/v8/8197
   'debugger/get-possible-breakpoints-class-fields': [SKIP],
@@ -70,8 +78,11 @@
 ##############################################################################
 ['arch == ppc or arch == ppc64', {
   # Liftoff needs to be enabled before running these tests.
+  'debugger/wasm-scope-info': [SKIP],
   'debugger/wasm-scope-info-liftoff': [SKIP],
   'debugger/wasm-set-breakpoint-liftoff': [SKIP],
+  'debugger/wasm-stepping-liftoff': [SKIP],
+  'debugger/wasm-inspect-many-registers': [SKIP],
 }],  # 'arch == ppc or arch == ppc64'
 
 ##############################################################################
@@ -79,16 +90,13 @@
   # Stack manipulations in LiveEdit is not implemented for this arch.
   'debugger/set-script-source-stack-padding': [SKIP],
   # Liftoff needs to be enabled before running these tests.
+  'debugger/wasm-scope-info': [SKIP],
   'debugger/wasm-scope-info-liftoff': [SKIP],
   'debugger/wasm-set-breakpoint-liftoff': [SKIP],
+  'debugger/wasm-stepping-liftoff': [SKIP],
+  'debugger/wasm-inspect-many-registers': [SKIP],
 }],  # 'arch == s390 or arch == s390x'
 
 ##############################################################################
-['variant != future', {
-  # Wasm native module cache is temporarily disabled in non-future variant
-  # (https://crbug.com/1070199)
-  'debugger/wasm-scripts': [SKIP],
-}],  # variant != future
-
 
 ]
diff --git a/deps/v8/test/inspector/isolate-data.cc b/deps/v8/test/inspector/isolate-data.cc
index 8011007e34..2d69ba4a43 100644
--- a/deps/v8/test/inspector/isolate-data.cc
+++ b/deps/v8/test/inspector/isolate-data.cc
@@ -76,10 +76,9 @@ IsolateData::IsolateData(TaskRunner* task_runner,
   v8::HandleScope handle_scope(isolate_.get());
   not_inspectable_private_.Reset(
       isolate_.get(),
-      v8::Private::ForApi(isolate_.get(), v8::String::NewFromUtf8(
-                                              isolate_.get(), "notInspectable",
-                                              v8::NewStringType::kNormal)
-                                              .ToLocalChecked()));
+      v8::Private::ForApi(
+          isolate_.get(),
+          v8::String::NewFromUtf8Literal(isolate_.get(), "notInspectable")));
 }
 
 IsolateData* IsolateData::FromContext(v8::Local<v8::Context> context) {
@@ -310,9 +309,7 @@ void IsolateData::PromiseRejectHandler(v8::PromiseRejectMessage data) {
   if (context.IsEmpty()) return;
   v8::Local<v8::Promise> promise = data.GetPromise();
   v8::Local<v8::Private> id_private = v8::Private::ForApi(
-      isolate,
-      v8::String::NewFromUtf8(isolate, "id", v8::NewStringType::kNormal)
-          .ToLocalChecked());
+      isolate, v8::String::NewFromUtf8Literal(isolate, "id"));
 
   if (data.GetEvent() == v8::kPromiseHandlerAddedAfterReject) {
     v8::Local<v8::Value> id;
@@ -373,9 +370,8 @@ std::vector<int> IsolateData::GetSessionIds(int context_group_id) {
 bool IsolateData::formatAccessorsAsProperties(v8::Local<v8::Value> object) {
   v8::Local<v8::Context> context = isolate()->GetCurrentContext();
   v8::Local<v8::Private> shouldFormatAccessorsPrivate = v8::Private::ForApi(
-      isolate(), v8::String::NewFromUtf8(isolate(), "allowAccessorFormatting",
-                                         v8::NewStringType::kNormal)
-                     .ToLocalChecked());
+      isolate(),
+      v8::String::NewFromUtf8Literal(isolate(), "allowAccessorFormatting"));
   CHECK(object->IsObject());
   return object.As<v8::Object>()
       ->HasPrivate(context, shouldFormatAccessorsPrivate)
@@ -461,13 +457,14 @@ namespace {
 class StringBufferImpl : public v8_inspector::StringBuffer {
  public:
   StringBufferImpl(v8::Isolate* isolate, v8::Local<v8::String> string)
-      : data_(ToVector(isolate, string)),
-        view_(data_.begin(), data_.length()) {}
-  const v8_inspector::StringView& string() override { return view_; }
+      : data_(ToVector(isolate, string)) {}
+
+  v8_inspector::StringView string() const override {
+    return v8_inspector::StringView(data_.begin(), data_.length());
+  }
 
  private:
   v8::internal::Vector<uint16_t> data_;
-  v8_inspector::StringView view_;
 };
 }  // anonymous namespace
 
diff --git a/deps/v8/test/inspector/protocol-test.js b/deps/v8/test/inspector/protocol-test.js
index 71e32f2f4e..3b514ab538 100644
--- a/deps/v8/test/inspector/protocol-test.js
+++ b/deps/v8/test/inspector/protocol-test.js
@@ -287,7 +287,9 @@ InspectorTest.Session = class {
       if (location.lineNumber != 0) {
         InspectorTest.log('Unexpected wasm line number: ' + location.lineNumber);
       }
-      InspectorTest.log(`Script ${script.url} byte offset ${location.columnNumber}: Wasm opcode 0x${script.bytecode[location.columnNumber].toString(16)}`);
+      let wasm_opcode = script.bytecode[location.columnNumber].toString(16);
+      if (wasm_opcode.length % 2) wasm_opcode = '0' + wasm_opcode;
+      InspectorTest.log(`Script ${script.url} byte offset ${location.columnNumber}: Wasm opcode 0x${wasm_opcode}`);
     } else {
       var lines = script.scriptSource.split('\n');
       var line = lines[location.lineNumber];
diff --git a/deps/v8/test/inspector/runtime/es6-module-expected.txt b/deps/v8/test/inspector/runtime/es6-module-expected.txt
index 65c543e45f..63d6696cf8 100644
--- a/deps/v8/test/inspector/runtime/es6-module-expected.txt
+++ b/deps/v8/test/inspector/runtime/es6-module-expected.txt
@@ -11,6 +11,7 @@ Checks basic ES6 modules support.
         isModule : true
         length : 83
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -29,6 +30,7 @@ Checks basic ES6 modules support.
         isModule : true
         length : 84
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -47,6 +49,7 @@ Checks basic ES6 modules support.
         isModule : true
         length : 286
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
@@ -206,6 +209,7 @@ console.log(239)
         isModule : true
         length : 1
         scriptId : <scriptId>
+        scriptLanguage : JavaScript
         sourceMapURL : 
         startColumn : 0
         startLine : 0
diff --git a/deps/v8/test/inspector/testcfg.py b/deps/v8/test/inspector/testcfg.py
index e07aa9e616..512bf54eb6 100644
--- a/deps/v8/test/inspector/testcfg.py
+++ b/deps/v8/test/inspector/testcfg.py
@@ -62,7 +62,8 @@ class TestCase(testcase.TestCase):
   def output_proc(self):
     return outproc.ExpectedOutProc(
         self.expected_outcomes,
-        os.path.join(self.suite.root, self.path) + EXPECTED_SUFFIX)
+        os.path.join(self.suite.root, self.path) + EXPECTED_SUFFIX,
+        self.suite.test_config.regenerate_expected_files)
 
 
 def GetSuite(*args, **kwargs):
diff --git a/deps/v8/test/intl/regress-10248.js b/deps/v8/test/intl/regress-10248.js
new file mode 100644
index 0000000000..c1cdc7b42a
--- /dev/null
+++ b/deps/v8/test/intl/regress-10248.js
@@ -0,0 +1,70 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// See https://tc39.es/ecma262/#sec-runtime-semantics-canonicalize-ch
+function Canonicalize(ch) {
+  var u = ch.toUpperCase();
+  if (u.length > 1) return ch;
+  var cu = u.charCodeAt(0);
+  if (ch.charCodeAt(0) >= 128 && cu < 128) return ch;
+  return cu;
+}
+
+function TestEquivalenceClass(eclass) {
+  for (var i = 0; i < eclass.length; i++) {
+    for (var j = 0; j < eclass.length; j++) {
+      if (i == j) continue;
+      var c1 = eclass[i];
+      var c2 = eclass[j];
+      var shouldMatch = Canonicalize(c1) === Canonicalize(c2);
+
+      var re1 = new RegExp(c1, 'i');
+      var re2 = new RegExp('[' + c1 + ']', 'i');
+
+      assertEquals(re1.test(c2), shouldMatch);
+      assertEquals(re2.test(c2), shouldMatch);
+    }
+  }
+}
+
+function TestAll() {
+  for (var eclass of equivalence_classes) {
+    TestEquivalenceClass(eclass);
+  }
+}
+
+// Interesting case-folding equivalence classes (as determined by
+// ICU's UnicodeSet::closeOver). A class is interesting if it contains
+// more than two characters, or if it contains any characters in
+// IgnoreSet or SpecialAddSet as defined in src/regexp/special-case.h.
+var equivalence_classes = [
+  '\u0041\u0061',              // Aa (sanity check)
+  '\u004b\u006b\u212a',        // KkK
+  '\u0053\u0073\u017f',        // Ssſ
+  '\u00b5\u039c\u03bc',        // µΜμ
+  '\u00c5\u00e5\u212b',        // ÅåÅ
+  '\u00df\u1e9e',              // ßẞ
+  '\u03a9\u03c9\u2126',        // ΩωΩ
+  '\u0390\u1fd3',              // ΐΐ
+  '\u0398\u03b8\u03d1\u03f4',  // Θθϑϴ
+  '\u03b0\u1fe3',              // ΰΰ
+  '\u1f80\u1f88',              // ᾀᾈ
+  '\u1fb3\u1fbc',              // ᾳᾼ
+  '\u1fc3\u1fcc',              // ῃῌ
+  '\u1ff3\u1ffc',              // ῳῼ
+  '\ufb05\ufb06',              // ſtst
+
+  // Everything below this line is a well-behaved case-folding
+  // equivalence class with more than two characters but only one
+  // canonical case-folded character
+  '\u01c4\u01c5\u01c6', '\u01c7\u01c8\u01c9', '\u01ca\u01cb\u01cc',
+  '\u01f1\u01f2\u01f3', '\u0345\u0399\u03b9\u1fbe', '\u0392\u03b2\u03d0',
+  '\u0395\u03b5\u03f5', '\u039a\u03ba\u03f0', '\u03a0\u03c0\u03d6',
+  '\u03a1\u03c1\u03f1', '\u03a3\u03c2\u03c3', '\u03a6\u03c6\u03d5',
+  '\u0412\u0432\u1c80', '\u0414\u0434\u1c81', '\u041e\u043e\u1c82',
+  '\u0421\u0441\u1c83', '\u0422\u0442\u1c84\u1c85', '\u042a\u044a\u1c86',
+  '\u0462\u0463\u1c87', '\u1c88\ua64a\ua64b', '\u1e60\u1e61\u1e9b'
+];
+
+TestAll();
diff --git a/deps/v8/test/intl/regress-1030160.js b/deps/v8/test/intl/regress-1030160.js
new file mode 100644
index 0000000000..0f04677db2
--- /dev/null
+++ b/deps/v8/test/intl/regress-1030160.js
@@ -0,0 +1,5 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+assertEquals("NaN", (null/null).toLocaleString());
diff --git a/deps/v8/test/intl/regress-1041319.js b/deps/v8/test/intl/regress-1041319.js
new file mode 100644
index 0000000000..7092194876
--- /dev/null
+++ b/deps/v8/test/intl/regress-1041319.js
@@ -0,0 +1,46 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Test to check "algorithmic" numbering systems stated in UTS35 but not
+// mandated by ECMA402 won't crash.
+// The entries which type is "algorithmic" in
+// https://github.com/unicode-org/cldr/blob/master/common/supplemental/numberingSystems.xml
+// These are numbering systems which is not supported in ECMA402 but we should
+// not crash.
+let algorithmicNumberingSystems = [
+    "armn",
+    "armnlow",
+    "cyrl",
+    "ethi",
+    "geor",
+    "grek",
+    "greklow",
+    "hanidays",
+    "hans",
+    "hansfin",
+    "hant",
+    "hantfin",
+    "hebr",
+    "jpan",
+    "jpanfin",
+    "jpanyear",
+    "roman",
+    "romanlow",
+    "taml",
+];
+
+for (numberingSystem of algorithmicNumberingSystems) {
+  let baseLocale = "en";
+  let locale = baseLocale + "-u-nu-" + numberingSystem;
+
+  // Ensure the creation won't crash
+  let rtf = new Intl.RelativeTimeFormat(locale);
+  let rtf2 = new Intl.RelativeTimeFormat(baseLocale, {numberingSystem});
+
+  let dtf = new Intl.DateTimeFormat(locale);
+  let dtf2 = new Intl.DateTimeFormat(baseLocale, {numberingSystem});
+
+  let nf = new Intl.NumberFormat(locale);
+  let nf2 = new Intl.NumberFormat(baseLocale, {numberingSystem});
+}
diff --git a/deps/v8/test/js-perf-test/Scope/with.js b/deps/v8/test/js-perf-test/Scope/with.js
index 8ec2d30cf0..b4c1893c6e 100644
--- a/deps/v8/test/js-perf-test/Scope/with.js
+++ b/deps/v8/test/js-perf-test/Scope/with.js
@@ -2,18 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-new BenchmarkSuite( 'With', [1000], [
-  new Benchmark('AccessOnSameLevel', false, false, 0,
-                AccessOnSameLevel, AccessOnSameLevelSetup,
-                AccessOnSameLevelTearDown),
-  new Benchmark('SetOnSameLevel', false, false, 0,
-                SetOnSameLevel, SetOnSameLevelSetup,
-                SetOnSameLevelTearDown),
-  new Benchmark('AccessOverPrototypeChain', false, false, 0,
-                AccessOverPrototypeChainSetup, AccessOverPrototypeChainSetup,
-                AccessOverPrototypeChainTearDown),
-  new Benchmark('CompetingScope', false, false, 0,
-                CompetingScope, CompetingScopeSetup, CompetingScopeTearDown)
+new BenchmarkSuite('With', [1000], [
+  new Benchmark(
+      'AccessOnSameLevel', false, false, 0, AccessOnSameLevel,
+      AccessOnSameLevelSetup, AccessOnSameLevelTearDown),
+  new Benchmark(
+      'SetOnSameLevel', false, false, 0, SetOnSameLevel, SetOnSameLevelSetup,
+      SetOnSameLevelTearDown),
+  new Benchmark(
+      'AccessOverPrototypeChain', false, false, 0, AccessOverPrototypeChain,
+      AccessOverPrototypeChainSetup, AccessOverPrototypeChainTearDown),
+  new Benchmark(
+      'CompetingScope', false, false, 0, CompetingScope, CompetingScopeSetup,
+      CompetingScopeTearDown)
 ]);
 
 var objectUnderTest;
diff --git a/deps/v8/test/message/fail/class-accessors-private-undefined-getter-nested.out b/deps/v8/test/message/fail/class-accessors-private-undefined-getter-nested.out
index ca3154a26b..66429501f6 100644
--- a/deps/v8/test/message/fail/class-accessors-private-undefined-getter-nested.out
+++ b/deps/v8/test/message/fail/class-accessors-private-undefined-getter-nested.out
@@ -1,10 +1,10 @@
 # Copyright 2019 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-*%(basename)s:9: TypeError: Cannot read private member C from an object whose class did not declare it
+*%(basename)s:9: TypeError: Object must be an instance of class C
   setA(obj, val) { obj.#a = val; }
                        ^
-TypeError: Cannot read private member C from an object whose class did not declare it
+TypeError: Object must be an instance of class C
     at C.setA (*%(basename)s:9:24)
     at new C (*%(basename)s:15:10)
     at *%(basename)s:19:1
\ No newline at end of file
diff --git a/deps/v8/test/message/fail/class-accessors-private-undefined-setter-nested.out b/deps/v8/test/message/fail/class-accessors-private-undefined-setter-nested.out
index 5f22848692..ffdc328a95 100644
--- a/deps/v8/test/message/fail/class-accessors-private-undefined-setter-nested.out
+++ b/deps/v8/test/message/fail/class-accessors-private-undefined-setter-nested.out
@@ -1,10 +1,10 @@
 # Copyright 2019 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
-*%(basename)s:9: TypeError: Cannot read private member C from an object whose class did not declare it
+*%(basename)s:9: TypeError: Object must be an instance of class C
   getA(obj) { return obj.#a; }
                          ^
-TypeError: Cannot read private member C from an object whose class did not declare it
+TypeError: Object must be an instance of class C
     at C.getA (*%(basename)s:9:26)
     at new C (*%(basename)s:15:10)
     at *%(basename)s:19:1
diff --git a/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.js b/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.js
new file mode 100644
index 0000000000..4f012e1b93
--- /dev/null
+++ b/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.js
@@ -0,0 +1,11 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+const C = class {
+  #a() {}
+  test(obj) { obj.#a(); }
+};
+(new C).test({});
diff --git a/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.out b/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.out
new file mode 100644
index 0000000000..e5efede21c
--- /dev/null
+++ b/deps/v8/test/message/fail/class-methods-private-brand-check-anonymous.out
@@ -0,0 +1,9 @@
+# Copyright 2020 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+*%(basename)s:9: TypeError: Object must be an instance of class anonymous
+  test(obj) { obj.#a(); }
+                  ^
+TypeError: Object must be an instance of class anonymous
+    at C.test (*%(basename)s:9:19)
+    at *%(basename)s:11:9
diff --git a/deps/v8/test/message/fail/class-methods-private-brand-check.js b/deps/v8/test/message/fail/class-methods-private-brand-check.js
new file mode 100644
index 0000000000..7d044b884e
--- /dev/null
+++ b/deps/v8/test/message/fail/class-methods-private-brand-check.js
@@ -0,0 +1,11 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+
+class C {
+  #a() {}
+  test(obj) { obj.#a(); }
+}
+(new C).test({});
diff --git a/deps/v8/test/message/fail/class-methods-private-brand-check.out b/deps/v8/test/message/fail/class-methods-private-brand-check.out
new file mode 100644
index 0000000000..fe166fa359
--- /dev/null
+++ b/deps/v8/test/message/fail/class-methods-private-brand-check.out
@@ -0,0 +1,9 @@
+# Copyright 2020 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+*%(basename)s:9: TypeError: Object must be an instance of class C
+  test(obj) { obj.#a(); }
+                  ^
+TypeError: Object must be an instance of class C
+    at C.test (*%(basename)s:9:19)
+    at *%(basename)s:11:9 
\ No newline at end of file
diff --git a/deps/v8/test/message/fail/spread-call-2.js b/deps/v8/test/message/fail/spread-call-2.js
new file mode 100644
index 0000000000..c66c93c75b
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call-2.js
@@ -0,0 +1,5 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+x = undefined;
+console.log(1, ...x);
diff --git a/deps/v8/test/message/fail/spread-call-2.out b/deps/v8/test/message/fail/spread-call-2.out
new file mode 100644
index 0000000000..7d1a4a8177
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call-2.out
@@ -0,0 +1,5 @@
+*%(basename)s:5: TypeError: x is not iterable (cannot read property undefined)
+console.log(1, ...x);
+                  ^
+TypeError: x is not iterable (cannot read property undefined)
+    at *%(basename)s:5:9
diff --git a/deps/v8/test/message/fail/spread-call-3.js b/deps/v8/test/message/fail/spread-call-3.js
new file mode 100644
index 0000000000..4068528771
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call-3.js
@@ -0,0 +1,6 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+p = undefined;
+f = () => 3;
+var [x] = f(...p);
diff --git a/deps/v8/test/message/fail/spread-call-3.out b/deps/v8/test/message/fail/spread-call-3.out
new file mode 100644
index 0000000000..ad87ac0410
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call-3.out
@@ -0,0 +1,5 @@
+*%(basename)s:6: TypeError: p is not iterable (cannot read property undefined)
+var [x] = f(...p);
+               ^
+TypeError: p is not iterable (cannot read property undefined)
+    at *%(basename)s:6:11
diff --git a/deps/v8/test/message/fail/spread-call.js b/deps/v8/test/message/fail/spread-call.js
new file mode 100644
index 0000000000..8642d5c32f
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call.js
@@ -0,0 +1,5 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+x = null;
+console.log(1, ...x);
diff --git a/deps/v8/test/message/fail/spread-call.out b/deps/v8/test/message/fail/spread-call.out
new file mode 100644
index 0000000000..3f1515ab01
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-call.out
@@ -0,0 +1,5 @@
+*%(basename)s:5: TypeError: x is not iterable (cannot read property null)
+console.log(1, ...x);
+                  ^
+TypeError: x is not iterable (cannot read property null)
+    at *%(basename)s:5:9
diff --git a/deps/v8/test/message/fail/spread-construct-2.js b/deps/v8/test/message/fail/spread-construct-2.js
new file mode 100644
index 0000000000..fd68a58b17
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct-2.js
@@ -0,0 +1,6 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+x = undefined;
+function p() {};
+p(1, ...x);
diff --git a/deps/v8/test/message/fail/spread-construct-2.out b/deps/v8/test/message/fail/spread-construct-2.out
new file mode 100644
index 0000000000..018d5b46af
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct-2.out
@@ -0,0 +1,5 @@
+*%(basename)s:6: TypeError: x is not iterable (cannot read property undefined)
+p(1, ...x);
+        ^
+TypeError: x is not iterable (cannot read property undefined)
+    at *%(basename)s:6:1
diff --git a/deps/v8/test/message/fail/spread-construct-3.js b/deps/v8/test/message/fail/spread-construct-3.js
new file mode 100644
index 0000000000..ef2e25bd7e
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct-3.js
@@ -0,0 +1,7 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+p = undefined;
+f = () => 3;
+function t() {};
+var [x] = new t(...p);
diff --git a/deps/v8/test/message/fail/spread-construct-3.out b/deps/v8/test/message/fail/spread-construct-3.out
new file mode 100644
index 0000000000..64d4bfcdce
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct-3.out
@@ -0,0 +1,5 @@
+*%(basename)s:7: TypeError: p is not iterable (cannot read property undefined)
+var [x] = new t(...p);
+                   ^
+TypeError: p is not iterable (cannot read property undefined)
+    at *%(basename)s:7:11
diff --git a/deps/v8/test/message/fail/spread-construct.js b/deps/v8/test/message/fail/spread-construct.js
new file mode 100644
index 0000000000..e45847d69c
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct.js
@@ -0,0 +1,6 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+x = null;
+function p() {};
+new p(1, ...x);
diff --git a/deps/v8/test/message/fail/spread-construct.out b/deps/v8/test/message/fail/spread-construct.out
new file mode 100644
index 0000000000..b8aa31de30
--- /dev/null
+++ b/deps/v8/test/message/fail/spread-construct.out
@@ -0,0 +1,5 @@
+*%(basename)s:6: TypeError: x is not iterable (cannot read property null)
+new p(1, ...x);
+            ^
+TypeError: x is not iterable (cannot read property null)
+    at *%(basename)s:6:1
diff --git a/deps/v8/test/message/fail/wasm-exception-rethrow.out b/deps/v8/test/message/fail/wasm-exception-rethrow.out
index c4c68e5b71..28fd825866 100644
--- a/deps/v8/test/message/fail/wasm-exception-rethrow.out
+++ b/deps/v8/test/message/fail/wasm-exception-rethrow.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x32: RuntimeError: wasm exception
 RuntimeError: wasm exception
-    at rethrow0 (wasm-function[0]:0x32)
+    at rethrow0 (<anonymous>:wasm-function[0]:0x32)
     at *%(basename)s:21:18
diff --git a/deps/v8/test/message/fail/wasm-exception-throw.out b/deps/v8/test/message/fail/wasm-exception-throw.out
index c94ae248c0..af45212f3f 100644
--- a/deps/v8/test/message/fail/wasm-exception-throw.out
+++ b/deps/v8/test/message/fail/wasm-exception-throw.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x2e: RuntimeError: wasm exception
 RuntimeError: wasm exception
-    at throw0 (wasm-function[0]:0x2e)
+    at throw0 (<anonymous>:wasm-function[0]:0x2e)
     at *%(basename)s:17:18
diff --git a/deps/v8/test/message/fail/wasm-function-name.out b/deps/v8/test/message/fail/wasm-function-name.out
index 3f4956a26e..182b15dc87 100644
--- a/deps/v8/test/message/fail/wasm-function-name.out
+++ b/deps/v8/test/message/fail/wasm-function-name.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x22: RuntimeError: unreachable
 RuntimeError: unreachable
-    at main (wasm-function[0]:0x22)
+    at main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:31
diff --git a/deps/v8/test/message/fail/wasm-module-and-function-name.out b/deps/v8/test/message/fail/wasm-module-and-function-name.out
index 1f25c57271..969ac55cbb 100644
--- a/deps/v8/test/message/fail/wasm-module-and-function-name.out
+++ b/deps/v8/test/message/fail/wasm-module-and-function-name.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x22: RuntimeError: unreachable
 RuntimeError: unreachable
-    at test-module.main (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:31
diff --git a/deps/v8/test/message/fail/wasm-module-name.out b/deps/v8/test/message/fail/wasm-module-name.out
index 763bec5592..969ac55cbb 100644
--- a/deps/v8/test/message/fail/wasm-module-name.out
+++ b/deps/v8/test/message/fail/wasm-module-name.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x22: RuntimeError: unreachable
 RuntimeError: unreachable
-    at test-module (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:31
diff --git a/deps/v8/test/message/fail/wasm-no-name.out b/deps/v8/test/message/fail/wasm-no-name.out
index 37836cc495..182b15dc87 100644
--- a/deps/v8/test/message/fail/wasm-no-name.out
+++ b/deps/v8/test/message/fail/wasm-no-name.out
@@ -1,4 +1,4 @@
 wasm-function[0]:0x22: RuntimeError: unreachable
 RuntimeError: unreachable
-    at wasm-function[0]:0x22
+    at main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:31
diff --git a/deps/v8/test/message/fail/wasm-trap.out b/deps/v8/test/message/fail/wasm-trap.out
index 66048388e4..85eb9845b4 100644
--- a/deps/v8/test/message/fail/wasm-trap.out
+++ b/deps/v8/test/message/fail/wasm-trap.out
@@ -1,4 +1,4 @@
 wasm-function[1]:0x30: RuntimeError: divide by zero
 RuntimeError: divide by zero
-    at main (wasm-function[1]:0x30)
+    at main (<anonymous>:wasm-function[1]:0x30)
     at *%(basename)s:{NUMBER}:16
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationgroup1.out b/deps/v8/test/message/fail/weak-refs-finalizationgroup1.out
deleted file mode 100644
index ddaa32328f..0000000000
--- a/deps/v8/test/message/fail/weak-refs-finalizationgroup1.out
+++ /dev/null
@@ -1,6 +0,0 @@
-*%(basename)s:7: TypeError: FinalizationGroup: cleanup must be callable
-let fg = new FinalizationGroup();
-         ^
-TypeError: FinalizationGroup: cleanup must be callable
-    at new FinalizationGroup (<anonymous>)
-    at *%(basename)s:7:10
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationgroup2.out b/deps/v8/test/message/fail/weak-refs-finalizationgroup2.out
deleted file mode 100644
index 799199aff8..0000000000
--- a/deps/v8/test/message/fail/weak-refs-finalizationgroup2.out
+++ /dev/null
@@ -1,6 +0,0 @@
-*%(basename)s:7: TypeError: FinalizationGroup: cleanup must be callable
-let fg = new FinalizationGroup({});
-         ^
-TypeError: FinalizationGroup: cleanup must be callable
-    at new FinalizationGroup (<anonymous>)
-    at *%(basename)s:7:10
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationgroup2.js b/deps/v8/test/message/fail/weak-refs-finalizationregistry1.js
index 87a6183de9..f23cfa3a51 100644
--- a/deps/v8/test/message/fail/weak-refs-finalizationgroup2.js
+++ b/deps/v8/test/message/fail/weak-refs-finalizationregistry1.js
@@ -4,4 +4,4 @@
 
 // Flags: --harmony-weak-refs
 
-let fg = new FinalizationGroup({});
+let fg = new FinalizationRegistry();
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationregistry1.out b/deps/v8/test/message/fail/weak-refs-finalizationregistry1.out
new file mode 100644
index 0000000000..7775052c91
--- /dev/null
+++ b/deps/v8/test/message/fail/weak-refs-finalizationregistry1.out
@@ -0,0 +1,6 @@
+*%(basename)s:7: TypeError: FinalizationRegistry: cleanup must be callable
+let fg = new FinalizationRegistry();
+         ^
+TypeError: FinalizationRegistry: cleanup must be callable
+    at new FinalizationRegistry (<anonymous>)
+    at *%(basename)s:7:10
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationgroup1.js b/deps/v8/test/message/fail/weak-refs-finalizationregistry2.js
index a97abb3f8b..599bfc6d05 100644
--- a/deps/v8/test/message/fail/weak-refs-finalizationgroup1.js
+++ b/deps/v8/test/message/fail/weak-refs-finalizationregistry2.js
@@ -4,4 +4,4 @@
 
 // Flags: --harmony-weak-refs
 
-let fg = new FinalizationGroup();
+let fg = new FinalizationRegistry({});
diff --git a/deps/v8/test/message/fail/weak-refs-finalizationregistry2.out b/deps/v8/test/message/fail/weak-refs-finalizationregistry2.out
new file mode 100644
index 0000000000..278c3506bf
--- /dev/null
+++ b/deps/v8/test/message/fail/weak-refs-finalizationregistry2.out
@@ -0,0 +1,6 @@
+*%(basename)s:7: TypeError: FinalizationRegistry: cleanup must be callable
+let fg = new FinalizationRegistry({});
+         ^
+TypeError: FinalizationRegistry: cleanup must be callable
+    at new FinalizationRegistry (<anonymous>)
+    at *%(basename)s:7:10
diff --git a/deps/v8/test/message/fail/weak-refs-register1.js b/deps/v8/test/message/fail/weak-refs-register1.js
index a90e4aa47c..7110a25e6c 100644
--- a/deps/v8/test/message/fail/weak-refs-register1.js
+++ b/deps/v8/test/message/fail/weak-refs-register1.js
@@ -4,5 +4,5 @@
 
 // Flags: --harmony-weak-refs
 
-let fg = new FinalizationGroup(() => {});
+let fg = new FinalizationRegistry(() => {});
 fg.register(1);
diff --git a/deps/v8/test/message/fail/weak-refs-register1.out b/deps/v8/test/message/fail/weak-refs-register1.out
index 96983664c2..6a9b23ecf8 100644
--- a/deps/v8/test/message/fail/weak-refs-register1.out
+++ b/deps/v8/test/message/fail/weak-refs-register1.out
@@ -1,6 +1,6 @@
-*%(basename)s:8: TypeError: FinalizationGroup.prototype.register: target must be an object
+*%(basename)s:8: TypeError: FinalizationRegistry.prototype.register: target must be an object
 fg.register(1);
    ^
-TypeError: FinalizationGroup.prototype.register: target must be an object
-    at FinalizationGroup.register (<anonymous>)
+TypeError: FinalizationRegistry.prototype.register: target must be an object
+    at FinalizationRegistry.register (<anonymous>)
     at *%(basename)s:8:4
diff --git a/deps/v8/test/message/fail/weak-refs-register2.js b/deps/v8/test/message/fail/weak-refs-register2.js
index 8934a46511..31df874585 100644
--- a/deps/v8/test/message/fail/weak-refs-register2.js
+++ b/deps/v8/test/message/fail/weak-refs-register2.js
@@ -4,6 +4,6 @@
 
 // Flags: --harmony-weak-refs
 
-let fg = new FinalizationGroup(() => {});
+let fg = new FinalizationRegistry(() => {});
 let o = {};
 fg.register(o, o);
diff --git a/deps/v8/test/message/fail/weak-refs-register2.out b/deps/v8/test/message/fail/weak-refs-register2.out
index c7b9e10909..0f2c2f1ee2 100644
--- a/deps/v8/test/message/fail/weak-refs-register2.out
+++ b/deps/v8/test/message/fail/weak-refs-register2.out
@@ -1,6 +1,6 @@
-*%(basename)s:9: TypeError: FinalizationGroup.prototype.register: target and holdings must not be same
+*%(basename)s:9: TypeError: FinalizationRegistry.prototype.register: target and holdings must not be same
 fg.register(o, o);
    ^
-TypeError: FinalizationGroup.prototype.register: target and holdings must not be same
-    at FinalizationGroup.register (<anonymous>)
+TypeError: FinalizationRegistry.prototype.register: target and holdings must not be same
+    at FinalizationRegistry.register (<anonymous>)
     at *%(basename)s:9:4
diff --git a/deps/v8/test/message/fail/weak-refs-unregister.js b/deps/v8/test/message/fail/weak-refs-unregister.js
index e0cf0282d2..0f41263cba 100644
--- a/deps/v8/test/message/fail/weak-refs-unregister.js
+++ b/deps/v8/test/message/fail/weak-refs-unregister.js
@@ -4,5 +4,5 @@
 
 // Flags: --harmony-weak-refs
 
-let fg = new FinalizationGroup(() => {});
+let fg = new FinalizationRegistry(() => {});
 fg.unregister(1);
diff --git a/deps/v8/test/message/fail/weak-refs-unregister.out b/deps/v8/test/message/fail/weak-refs-unregister.out
index 938665157d..766d04349f 100644
--- a/deps/v8/test/message/fail/weak-refs-unregister.out
+++ b/deps/v8/test/message/fail/weak-refs-unregister.out
@@ -2,5 +2,5 @@
 fg.unregister(1);
    ^
 TypeError: unregisterToken ('1') must be an object
-    at FinalizationGroup.unregister (<anonymous>)
+    at FinalizationRegistry.unregister (<anonymous>)
     at *%(basename)s:8:4
diff --git a/deps/v8/test/message/wasm-function-name-async.out b/deps/v8/test/message/wasm-function-name-async.out
index a298b07414..ad003ef227 100644
--- a/deps/v8/test/message/wasm-function-name-async.out
+++ b/deps/v8/test/message/wasm-function-name-async.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at main (wasm-function[0]:0x22)
+    at main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-function-name-streaming.out b/deps/v8/test/message/wasm-function-name-streaming.out
index e880c3c322..4e8b7d5a5a 100644
--- a/deps/v8/test/message/wasm-function-name-streaming.out
+++ b/deps/v8/test/message/wasm-function-name-streaming.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at main (wasm-function[0]:0x22)
+    at main (<anonymous>:wasm-function[0]:0x22)
     at test/message/wasm-function-name-async.js:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-module-and-function-name-async.out b/deps/v8/test/message/wasm-module-and-function-name-async.out
index 0cb61c4a6e..f2d044245b 100644
--- a/deps/v8/test/message/wasm-module-and-function-name-async.out
+++ b/deps/v8/test/message/wasm-module-and-function-name-async.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at test-module.main (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-module-and-function-name-streaming.out b/deps/v8/test/message/wasm-module-and-function-name-streaming.out
index 2367c6f3cf..8e6eebad7f 100644
--- a/deps/v8/test/message/wasm-module-and-function-name-streaming.out
+++ b/deps/v8/test/message/wasm-module-and-function-name-streaming.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at test-module.main (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at test/message/wasm-module-and-function-name-async.js:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-module-name-async.out b/deps/v8/test/message/wasm-module-name-async.out
index a1c9f69b2b..f2d044245b 100644
--- a/deps/v8/test/message/wasm-module-name-async.out
+++ b/deps/v8/test/message/wasm-module-name-async.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at test-module (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-module-name-streaming.out b/deps/v8/test/message/wasm-module-name-streaming.out
index c9e029c250..e7435267e9 100644
--- a/deps/v8/test/message/wasm-module-name-streaming.out
+++ b/deps/v8/test/message/wasm-module-name-streaming.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at test-module (wasm-function[0]:0x22)
+    at test-module.main (<anonymous>:wasm-function[0]:0x22)
     at test/message/wasm-module-name-async.js:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-no-name-async.out b/deps/v8/test/message/wasm-no-name-async.out
index 55a722dcb1..ad003ef227 100644
--- a/deps/v8/test/message/wasm-no-name-async.out
+++ b/deps/v8/test/message/wasm-no-name-async.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at wasm-function[0]:0x22
+    at main (<anonymous>:wasm-function[0]:0x22)
     at *%(basename)s:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-no-name-streaming.out b/deps/v8/test/message/wasm-no-name-streaming.out
index b117074f78..987952db8b 100644
--- a/deps/v8/test/message/wasm-no-name-streaming.out
+++ b/deps/v8/test/message/wasm-no-name-streaming.out
@@ -1,4 +1,4 @@
 RuntimeError: unreachable
-    at wasm-function[0]:0x22
+    at main (<anonymous>:wasm-function[0]:0x22)
     at test/message/wasm-no-name-async.js:{NUMBER}:27
     at test/mjsunit/mjsunit.js:*
diff --git a/deps/v8/test/message/wasm-trace-memory-interpreted.out b/deps/v8/test/message/wasm-trace-memory-interpreted.out
index e390f10fe3..e04e6964ca 100644
--- a/deps/v8/test/message/wasm-trace-memory-interpreted.out
+++ b/deps/v8/test/message/wasm-trace-memory-interpreted.out
@@ -9,3 +9,6 @@ interpreter func:     0+0x3     load from 00000002 val: i32:1454047232 / 56ab000
 interpreter func:     2+0x3     load from 00000002 val: f32:94008244174848.000000 / 56ab0000
 interpreter func:     6+0x7      store to 00000004 val: s128:48879 48879 48879 48879 / 0000beef 0000beef 0000beef 0000beef
 interpreter func:     5+0x3     load from 00000002 val: s128:-1091633152 -1091633152 -1091633152 -1091633152 / beef0000 beef0000 beef0000 beef0000
+interpreter func:     7+0x3     load from 00000004 val: i16:48879 / beef
+interpreter func:     8+0x3     load from 00000002 val: i64:-4688528683866062848 / beef0000beef0000
+interpreter func:     9+0x3     load from 00000002 val: f64:-0.000015 / beef0000beef0000
diff --git a/deps/v8/test/message/wasm-trace-memory-liftoff.out b/deps/v8/test/message/wasm-trace-memory-liftoff.out
index 76364cdfaf..5682bca57a 100644
--- a/deps/v8/test/message/wasm-trace-memory-liftoff.out
+++ b/deps/v8/test/message/wasm-trace-memory-liftoff.out
@@ -7,5 +7,8 @@ liftoff     func:     2+0x3     load from 00000002 val: f32:68169720922112.00000
 liftoff     func:     4+0x5      store to 00000004 val:  i8:171 / ab
 liftoff     func:     0+0x3     load from 00000002 val: i32:1454047232 / 56ab0000
 liftoff     func:     2+0x3     load from 00000002 val: f32:94008244174848.000000 / 56ab0000
-turbofan    func:     6+0x7      store to 00000004 val: s128:48879 48879 48879 48879 / 0000beef 0000beef 0000beef 0000beef
+liftoff     func:     6+0x7      store to 00000004 val: s128:48879 48879 48879 48879 / 0000beef 0000beef 0000beef 0000beef
 liftoff     func:     5+0x3     load from 00000002 val: s128:-1091633152 -1091633152 -1091633152 -1091633152 / beef0000 beef0000 beef0000 beef0000
+liftoff     func:     7+0x3     load from 00000004 val: i16:48879 / beef
+liftoff     func:     8+0x3     load from 00000002 val: i64:-4688528683866062848 / beef0000beef0000
+liftoff     func:     9+0x3     load from 00000002 val: f64:-0.000015 / beef0000beef0000
diff --git a/deps/v8/test/message/wasm-trace-memory.js b/deps/v8/test/message/wasm-trace-memory.js
index 4102dad6f0..b268c63106 100644
--- a/deps/v8/test/message/wasm-trace-memory.js
+++ b/deps/v8/test/message/wasm-trace-memory.js
@@ -31,6 +31,17 @@ builder.addFunction('load128', kSig_v_i)
 builder.addFunction('store128', kSig_v_ii)
     .addBody([kExprLocalGet, 0, kExprLocalGet, 1, kSimdPrefix, kExprI32x4Splat, kSimdPrefix, kExprS128StoreMem, 0, 0])
     .exportFunc();
+// We add functions after, rather than sorting in some order, so as to keep
+// the .out changes small (due to function index).
+builder.addFunction('load16', kSig_v_i)
+    .addBody([kExprLocalGet, 0, kExprI32LoadMem16U, 0, 0, kExprDrop])
+    .exportFunc();
+builder.addFunction('load64', kSig_v_i)
+    .addBody([kExprLocalGet, 0, kExprI64LoadMem, 0, 0, kExprDrop])
+    .exportFunc();
+builder.addFunction('loadf64', kSig_v_i)
+    .addBody([kExprLocalGet, 0, kExprF64LoadMem, 0, 0, kExprDrop])
+    .exportFunc();
 var module = builder.instantiate();
 
 module.exports.load(4);
@@ -44,3 +55,6 @@ module.exports.load(2);
 module.exports.loadf(2);
 module.exports.store128(4, 0xbeef);
 module.exports.load128(2);
+module.exports.load16(4);
+module.exports.load64(2);
+module.exports.loadf64(2);
diff --git a/deps/v8/test/message/wasm-trace-memory.out b/deps/v8/test/message/wasm-trace-memory.out
index f41bc30fee..cfb707b543 100644
--- a/deps/v8/test/message/wasm-trace-memory.out
+++ b/deps/v8/test/message/wasm-trace-memory.out
@@ -9,3 +9,6 @@ turbofan    func:     0+0x3     load from 00000002 val: i32:1454047232 / 56ab000
 turbofan    func:     2+0x3     load from 00000002 val: f32:94008244174848.000000 / 56ab0000
 turbofan    func:     6+0x7      store to 00000004 val: s128:48879 48879 48879 48879 / 0000beef 0000beef 0000beef 0000beef
 turbofan    func:     5+0x3     load from 00000002 val: s128:-1091633152 -1091633152 -1091633152 -1091633152 / beef0000 beef0000 beef0000 beef0000
+turbofan    func:     7+0x3     load from 00000004 val: i16:48879 / beef
+turbofan    func:     8+0x3     load from 00000002 val: i64:-4688528683866062848 / beef0000beef0000
+turbofan    func:     9+0x3     load from 00000002 val: f64:-0.000015 / beef0000beef0000
diff --git a/deps/v8/test/message/weakref-finalizationregistry-error.js b/deps/v8/test/message/weakref-finalizationregistry-error.js
new file mode 100644
index 0000000000..1db6bfeccd
--- /dev/null
+++ b/deps/v8/test/message/weakref-finalizationregistry-error.js
@@ -0,0 +1,26 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --no-stress-opt
+
+// Since cleanup tasks are top-level tasks, errors thrown from them don't stop
+// future cleanup tasks from running.
+
+function callback(iter) {
+  [...iter];
+  throw new Error('callback');
+};
+
+const fg1 = new FinalizationRegistry(callback);
+const fg2 = new FinalizationRegistry(callback);
+
+(function() {
+let x = {};
+fg1.register(x, {});
+fg2.register(x, {});
+x = null;
+})();
+
+gc();
diff --git a/deps/v8/test/message/weakref-finalizationregistry-error.out b/deps/v8/test/message/weakref-finalizationregistry-error.out
new file mode 100644
index 0000000000..4682b63f23
--- /dev/null
+++ b/deps/v8/test/message/weakref-finalizationregistry-error.out
@@ -0,0 +1,12 @@
+*%(basename)s:{NUMBER}: Error: callback
+  throw new Error('callback');
+  ^
+Error: callback
+    at callback (*%(basename)s:{NUMBER}:{NUMBER})
+
+*%(basename)s:{NUMBER}: Error: callback
+  throw new Error('callback');
+  ^
+Error: callback
+    at callback (*%(basename)s:{NUMBER}:{NUMBER})
+
diff --git a/deps/v8/test/mjsunit/BUILD.gn b/deps/v8/test/mjsunit/BUILD.gn
index 847565f91a..f48c0bba5e 100644
--- a/deps/v8/test/mjsunit/BUILD.gn
+++ b/deps/v8/test/mjsunit/BUILD.gn
@@ -12,6 +12,9 @@ group("v8_mjsunit") {
 
   data = [
     "./",
+    "../../tools/clusterfuzz/v8_mock.js",
+    "../../tools/clusterfuzz/v8_mock_archs.js",
+    "../../tools/clusterfuzz/v8_mock_webassembly.js",
     "../../tools/codemap.js",
     "../../tools/consarray.js",
     "../../tools/csvparser.js",
diff --git a/deps/v8/test/mjsunit/array-reduce.js b/deps/v8/test/mjsunit/array-reduce.js
index 5d431b024d..b525406ad7 100644
--- a/deps/v8/test/mjsunit/array-reduce.js
+++ b/deps/v8/test/mjsunit/array-reduce.js
@@ -25,11 +25,11 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --opt --no-lazy-feedback-allocation
 
-/**
- * @fileoverview Test reduce and reduceRight
- */
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 function clone(v) {
   // Shallow-copies arrays, returns everything else verbatim.
diff --git a/deps/v8/test/mjsunit/asm/regress-674089.js b/deps/v8/test/mjsunit/asm/regress-674089.js
index edba023dec..7c0e89d3ee 100644
--- a/deps/v8/test/mjsunit/asm/regress-674089.js
+++ b/deps/v8/test/mjsunit/asm/regress-674089.js
@@ -7,10 +7,7 @@
 function outer() {
   "use asm";
   function inner() {
-    switch (1) {
-      case 0:
-        break foo;
-    }
+    /f(/
   }
 }
 outer();
diff --git a/deps/v8/test/mjsunit/call-intrinsic-differential-fuzzing.js b/deps/v8/test/mjsunit/call-intrinsic-differential-fuzzing.js
new file mode 100644
index 0000000000..867f5f7cee
--- /dev/null
+++ b/deps/v8/test/mjsunit/call-intrinsic-differential-fuzzing.js
@@ -0,0 +1,8 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-for-differential-fuzzing
+
+// Test blacklisted intrinsics in the context of differential fuzzing.
+assertEquals(undefined, %IsBeingInterpreted());
diff --git a/deps/v8/test/mjsunit/call-intrinsic-fuzzing.js b/deps/v8/test/mjsunit/call-intrinsic-fuzzing.js
new file mode 100644
index 0000000000..3945c8d49d
--- /dev/null
+++ b/deps/v8/test/mjsunit/call-intrinsic-fuzzing.js
@@ -0,0 +1,26 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-for-fuzzing
+
+// Test whitelisted/blacklisted intrinsics in the context of fuzzing.
+
+// Blacklisted intrinsics are replaced with undefined.
+assertEquals(undefined, %GetOptimizationStatus(function (){}));
+
+// Blacklisted intrinsics can have wrong arguments.
+assertEquals(undefined, %GetOptimizationStatus(1, 2, 3, 4));
+
+// We don't care if an intrinsic actually exists.
+assertEquals(undefined, %FooBar());
+
+// Check whitelisted intrinsic.
+assertNotEquals(undefined, %IsBeingInterpreted());
+
+// Whitelisted runtime functions with too few args are ignored.
+assertEquals(undefined, %DeoptimizeFunction());
+
+// Superfluous arguments are ignored.
+%DeoptimizeFunction(function() {}, undefined);
+assertNotEquals(undefined, %IsBeingInterpreted(1, 2, 3));
diff --git a/deps/v8/test/mjsunit/compiler/inlined-call-polymorphic.js b/deps/v8/test/mjsunit/compiler/inlined-call-polymorphic.js
new file mode 100644
index 0000000000..f56cae9c4e
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/inlined-call-polymorphic.js
@@ -0,0 +1,24 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Flags: --allow-natives-syntax --opt
+
+function make_closure() { return () => { return 42; } }
+%PrepareFunctionForOptimization(make_closure);
+%PrepareFunctionForOptimization(make_closure());
+
+function inline_polymorphic(f) {
+  let answer = f();
+  %TurbofanStaticAssert(answer == 42);
+}
+
+%PrepareFunctionForOptimization(inline_polymorphic);
+inline_polymorphic(make_closure());
+inline_polymorphic(make_closure());
+%OptimizeFunctionOnNextCall(inline_polymorphic);
+inline_polymorphic(make_closure());
+
+try {
+  inline_polymorphic(3);
+} catch(e) {}
diff --git a/deps/v8/test/mjsunit/compiler/osr-block-scope-id.js b/deps/v8/test/mjsunit/compiler/osr-block-scope-id.js
index 2d7f558c0d..25649b3bbb 100644
--- a/deps/v8/test/mjsunit/compiler/osr-block-scope-id.js
+++ b/deps/v8/test/mjsunit/compiler/osr-block-scope-id.js
@@ -36,6 +36,7 @@ function check() {
   }
   assertEquals(0, r.length);
 }
+%PrepareFunctionForOptimization(check);
 
 check();
 check();
diff --git a/deps/v8/test/mjsunit/compiler/regress-1061678.js b/deps/v8/test/mjsunit/compiler/regress-1061678.js
new file mode 100644
index 0000000000..fac2326a0a
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1061678.js
@@ -0,0 +1,20 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+Array.prototype[10] = 2;
+
+function foo() {
+  try {
+    [].forEach();
+  } catch (e) {
+  }
+};
+
+%PrepareFunctionForOptimization(foo);
+foo();
+foo();
+%OptimizeFunctionOnNextCall(foo);
+foo();
diff --git a/deps/v8/test/mjsunit/compiler/regress-1061803.js b/deps/v8/test/mjsunit/compiler/regress-1061803.js
new file mode 100644
index 0000000000..b951ab70e9
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1061803.js
@@ -0,0 +1,15 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+function foo() {
+  return arguments[1][0] === arguments[0];
+}
+
+%PrepareFunctionForOptimization(foo);
+assertFalse(foo(0, 0));
+assertFalse(foo(0, 0));
+%OptimizeFunctionOnNextCall(foo);
+assertThrows(foo, TypeError);
diff --git a/deps/v8/test/mjsunit/compiler/regress-1062916.js b/deps/v8/test/mjsunit/compiler/regress-1062916.js
new file mode 100644
index 0000000000..f7064571ea
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1062916.js
@@ -0,0 +1,20 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --no-analyze-environment-liveness --no-use-ic
+
+function foo(x) {
+  var a = [];
+  for (var k1 in x) {
+    for (var k2 in x) {
+      a.k2;
+    }
+  }
+  return a.join();
+}
+
+%PrepareFunctionForOptimization(foo);
+foo({p: 42});
+%OptimizeFunctionOnNextCall(foo);
+foo();
diff --git a/deps/v8/test/mjsunit/compiler/regress-1063661.js b/deps/v8/test/mjsunit/compiler/regress-1063661.js
new file mode 100644
index 0000000000..e2ff2cb0de
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1063661.js
@@ -0,0 +1,18 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --interrupt-budget=1024
+
+function main() {
+  const v1 = [];
+  for (let v11 = 0; v11 < 7; v11++) {
+    for (let v16 = 0; v16 != 100; v16++) {}
+    for (let v18 = -0.0; v18 < 7; v18 = v18 || 13.37) {
+      const v21 = Math.max(-339,v18);
+      v1.fill();
+      undefined % v21;
+    }
+  }
+}
+main();
diff --git a/deps/v8/test/mjsunit/compiler/regress-1072171.js b/deps/v8/test/mjsunit/compiler/regress-1072171.js
new file mode 100644
index 0000000000..6f6d063c8c
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1072171.js
@@ -0,0 +1,45 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+function testMax1(b) {
+  const max = Math.max(-1, b ? -0 : 1);
+  return Object.is(max, -0);
+}
+%PrepareFunctionForOptimization(testMax1);
+assertTrue(testMax1(true));
+assertTrue(testMax1(true));
+%OptimizeFunctionOnNextCall(testMax1);
+assertTrue(testMax1(true));
+
+function testMax2(b) {
+  const max = Math.max(b ? -0 : 1, -1);
+  return Object.is(max, -0);
+}
+%PrepareFunctionForOptimization(testMax2);
+assertTrue(testMax2(true));
+assertTrue(testMax2(true));
+%OptimizeFunctionOnNextCall(testMax2);
+assertTrue(testMax2(true));
+
+function testMin1(b) {
+  const min = Math.min(1, b ? -0 : -1);
+  return Object.is(min, -0);
+}
+%PrepareFunctionForOptimization(testMin1);
+assertTrue(testMin1(true));
+assertTrue(testMin1(true));
+%OptimizeFunctionOnNextCall(testMin1);
+assertTrue(testMin1(true));
+
+function testMin2(b) {
+  const min = Math.min(b ? -0 : -1, 1);
+  return Object.is(min, -0);
+}
+%PrepareFunctionForOptimization(testMin2);
+assertTrue(testMin2(true));
+assertTrue(testMin2(true));
+%OptimizeFunctionOnNextCall(testMin2);
+assertTrue(testMin2(true));
diff --git a/deps/v8/test/mjsunit/es6/unicode-regexp-ignore-case-noi18n.js b/deps/v8/test/mjsunit/es6/unicode-regexp-ignore-case-noi18n.js
index a99894234a..8f110e1d21 100644
--- a/deps/v8/test/mjsunit/es6/unicode-regexp-ignore-case-noi18n.js
+++ b/deps/v8/test/mjsunit/es6/unicode-regexp-ignore-case-noi18n.js
@@ -29,11 +29,24 @@ assertFalse(/\u{10400}/ui.test("\u{10428}"));
 assertFalse(/\ud801\udc00/ui.test("\u{10428}"));
 assertFalse(/[\u{10428}]/ui.test("\u{10400}"));
 assertFalse(/[\ud801\udc28]/ui.test("\u{10400}"));
-assertEquals(["\uff21\u{10400}"],
-             /[\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc"));
-assertEquals(["abc"], /[^\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc\uff23"));
-assertEquals(["\uff53\u24bb"],
-             /[\u24d5-\uff33]+/ui.exec("\uff54\uff53\u24bb\u24ba"));
+
+// TODO(v8:10120): Investigate why these don't behave as expected.
+{
+  // assertEquals(["\uff21\u{10400}"],
+  //              /[\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc"));
+  assertEquals(["\u{10400}"],
+               /[\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc"));
+}
+{
+  // assertEquals(["abc"], /[^\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc\uff23"));
+  assertEquals(["\u{ff21}"], /[^\uff40-\u{10428}]+/ui.exec("\uff21\u{10400}abc\uff23"));
+}
+{
+  // assertEquals(["\uff53\u24bb"],
+  //              /[\u24d5-\uff33]+/ui.exec("\uff54\uff53\u24bb\u24ba"));
+  assertEquals(null,
+               /[\u24d5-\uff33]+/ui.exec("\uff54\uff53\u24bb\u24ba"));
+}
 
 // Full mappings are ignored.
 assertFalse(/\u00df/ui.test("SS"));
diff --git a/deps/v8/test/mjsunit/for-in-special-cases.js b/deps/v8/test/mjsunit/for-in-special-cases.js
index 744c948b94..5470985947 100644
--- a/deps/v8/test/mjsunit/for-in-special-cases.js
+++ b/deps/v8/test/mjsunit/for-in-special-cases.js
@@ -179,7 +179,7 @@ for_in_string_prototype();
   }
 })();
 
-(function for_in_prototype_change_element() {
+(function for_in_prototype_change_element1() {
   let prototype1 = {prop: 0, prop1: 1};
   let derived1 = {prop2: 2, prop3: 3};
 
@@ -199,6 +199,74 @@ for_in_string_prototype();
   }
 })();
 
+(function for_in_prototype_change_element2() {
+  Array.prototype.__proto__ = {'A': 1};
+  let array = ['a', 'b', 'c', 'd', 'e'];
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['0', '1', '2', '3', '4', 'A'], Accumulate(array));
+  }
+  Array.prototype[10] = 'b';
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['0', '1', '2', '3', '4', '10', 'A'], Accumulate(array));
+  }
+})();
+
+(function for_in_prototype_change_element3() {
+  let prototype = {prop: 0};
+  let holey_array = {
+    1: 'a',
+    get 3() {
+      delete this[5];
+      return 'b';
+    },
+    5: 'c'
+  };
+  Object.setPrototypeOf(holey_array, prototype);
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['1', '3', '5', 'prop'], Accumulate(holey_array));
+  }
+  prototype[10] = 'b';
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['1', '3', '5', '10', 'prop'], Accumulate(holey_array));
+  }
+  for (let i = 0; i < 3; i++) {
+    var accumulator = [];
+    for (var j in holey_array) {
+      accumulator.push(j);
+      holey_array[j];
+    }
+    assertEquals(['1', '3', '10', 'prop'], accumulator);
+  }
+})();
+
+(function for_in_prototype_change_element4() {
+  let prototype = {
+    1: 'a',
+    get 3() {
+      delete this[5];
+      return 'b';
+    },
+    5: 'c',
+  };
+  let holey_array = {7: 'd', 9: 'e'};
+  Object.setPrototypeOf(holey_array, prototype);
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['7', '9', '1', '3', '5'], Accumulate(holey_array));
+  }
+  prototype.prop = 0;
+  for (let i = 0; i < 3; i++) {
+    assertEquals(['7', '9', '1', '3', '5', 'prop'], Accumulate(holey_array));
+  }
+  for (let i = 0; i < 3; i++) {
+    var accumulator = [];
+    for (var j in holey_array) {
+      accumulator.push(j);
+      prototype[j];
+    }
+    assertEquals(['7', '9', '1', '3', 'prop'], accumulator);
+  }
+})();
+
 (function for_in_non_enumerable1() {
   let prototype1 = {prop: 0};
   let derived1 = Object.create(prototype1, {
diff --git a/deps/v8/test/mjsunit/frozen-array-reduce.js b/deps/v8/test/mjsunit/frozen-array-reduce.js
index 6f121ae5fe..217dade6f1 100644
--- a/deps/v8/test/mjsunit/frozen-array-reduce.js
+++ b/deps/v8/test/mjsunit/frozen-array-reduce.js
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --allow-natives-syntax --opt --no-always-opt --no-lazy-feedback-allocation
 
-/**
- * @fileoverview Test reduce and reduceRight
- */
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 function clone(v) {
   // Shallow-copies arrays, returns everything else verbatim.
diff --git a/deps/v8/test/mjsunit/harmony/async-generators-throw-caught.js b/deps/v8/test/mjsunit/harmony/async-generators-throw-caught.js
new file mode 100644
index 0000000000..152a87cce1
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/async-generators-throw-caught.js
@@ -0,0 +1,24 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+let caught_in_gen = false;
+async function* catch_gen() {
+  try {
+    yield 42;
+  } catch (e) {
+    caught_in_gen = true;
+  }
+}
+
+(async () => {
+  const g = catch_gen();
+  await g.next();
+  try {
+    await g.throw(new Error()); // Should be caught in catch_gen, then catch_gen
+                                // completes normally.
+  } catch (e) {
+    assertUnreachable();
+  }
+  assertTrue(caught_in_gen);
+})();
diff --git a/deps/v8/test/mjsunit/harmony/bigint/property-names.js b/deps/v8/test/mjsunit/harmony/bigint/property-names.js
index 8c1763053c..ac65e1041d 100644
--- a/deps/v8/test/mjsunit/harmony/bigint/property-names.js
+++ b/deps/v8/test/mjsunit/harmony/bigint/property-names.js
@@ -3,5 +3,7 @@
 // found in the LICENSE file.
 
 var { 9007199254740991n: it } = { 9007199254740991n: 1 };
+assertEquals(it, 1);
 
+var { 999999999999999999n: it } = { 999999999999999999n: 1 }; // greater than max safe integer
 assertEquals(it, 1);
diff --git a/deps/v8/test/mjsunit/harmony/private-methods-empty-inner.js b/deps/v8/test/mjsunit/harmony/private-methods-empty-inner.js
new file mode 100644
index 0000000000..20fb575694
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/private-methods-empty-inner.js
@@ -0,0 +1,30 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-private-methods
+// This tests that empty inner classes don't assign private brands of outer
+// classes in their instances after scope chain deserialization.
+
+'use strict';
+
+class Outer {
+  constructor() {}
+#method(){}
+  factory() {
+    class Inner {
+      constructor() {}
+    }
+    return Inner;
+  }
+  run(obj) {
+    obj.#method();
+  }
+}
+
+const instance = new Outer();
+const Inner = instance.factory();
+// It should not pass the brand check.
+assertThrows(() => instance.run(new Inner()), TypeError);
+// It should pass the brand check.
+instance.run(new Outer());
diff --git a/deps/v8/test/mjsunit/harmony/private-methods.js b/deps/v8/test/mjsunit/harmony/private-methods.js
index b42e4f658c..7147c6d255 100644
--- a/deps/v8/test/mjsunit/harmony/private-methods.js
+++ b/deps/v8/test/mjsunit/harmony/private-methods.js
@@ -266,8 +266,10 @@
 }
 
 {
-  // TODO(v8:9177): test extending a class expression that does not have
-  // a private method.
+  class A extends class { } {
+    #a() {}
+  }
+
   class D extends class {
     #c() {}
   } {
@@ -278,6 +280,7 @@
     #e() {}
   }
 
+  new A;
   new D;
   new E;
 }
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/basics.js b/deps/v8/test/mjsunit/harmony/weakrefs/basics.js
index df599ebd40..9a1a99efe4 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/basics.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/basics.js
@@ -4,52 +4,52 @@
 
 // Flags: --harmony-weak-refs
 
-(function TestConstructFinalizationGroup() {
-  let fg = new FinalizationGroup(() => {});
-  assertEquals(fg.toString(), "[object FinalizationGroup]");
+(function TestConstructFinalizationRegistry() {
+  let fg = new FinalizationRegistry(() => {});
+  assertEquals(fg.toString(), "[object FinalizationRegistry]");
   assertNotSame(fg.__proto__, Object.prototype);
   assertSame(fg.__proto__.__proto__, Object.prototype);
 })();
 
-(function TestFinalizationGroupConstructorCallAsFunction() {
+(function TestFinalizationRegistryConstructorCallAsFunction() {
   let caught = false;
   let message = "";
   try {
-    let f = FinalizationGroup(() => {});
+    let f = FinalizationRegistry(() => {});
   } catch (e) {
     message = e.message;
     caught = true;
   } finally {
     assertTrue(caught);
-    assertEquals(message, "Constructor FinalizationGroup requires 'new'");
+    assertEquals(message, "Constructor FinalizationRegistry requires 'new'");
   }
 })();
 
-(function TestConstructFinalizationGroupCleanupNotCallable() {
-  let message = "FinalizationGroup: cleanup must be callable";
-  assertThrows(() => { let fg = new FinalizationGroup(); }, TypeError, message);
-  assertThrows(() => { let fg = new FinalizationGroup(1); }, TypeError, message);
-  assertThrows(() => { let fg = new FinalizationGroup(null); }, TypeError, message);
+(function TestConstructFinalizationRegistryCleanupNotCallable() {
+  let message = "FinalizationRegistry: cleanup must be callable";
+  assertThrows(() => { let fg = new FinalizationRegistry(); }, TypeError, message);
+  assertThrows(() => { let fg = new FinalizationRegistry(1); }, TypeError, message);
+  assertThrows(() => { let fg = new FinalizationRegistry(null); }, TypeError, message);
 })();
 
-(function TestConstructFinalizationGroupWithCallableProxyAsCleanup() {
+(function TestConstructFinalizationRegistryWithCallableProxyAsCleanup() {
   let handler = {};
   let obj = () => {};
   let proxy = new Proxy(obj, handler);
-  let fg = new FinalizationGroup(proxy);
+  let fg = new FinalizationRegistry(proxy);
 })();
 
-(function TestConstructFinalizationGroupWithNonCallableProxyAsCleanup() {
-  let message = "FinalizationGroup: cleanup must be callable";
+(function TestConstructFinalizationRegistryWithNonCallableProxyAsCleanup() {
+  let message = "FinalizationRegistry: cleanup must be callable";
   let handler = {};
   let obj = {};
   let proxy = new Proxy(obj, handler);
-  assertThrows(() => { let fg = new FinalizationGroup(proxy); }, TypeError, message);
+  assertThrows(() => { let fg = new FinalizationRegistry(proxy); }, TypeError, message);
 })();
 
 (function TestRegisterWithNonObjectTarget() {
-  let fg = new FinalizationGroup(() => {});
-  let message = "FinalizationGroup.prototype.register: target must be an object";
+  let fg = new FinalizationRegistry(() => {});
+  let message = "FinalizationRegistry.prototype.register: target must be an object";
   assertThrows(() => fg.register(1, "holdings"), TypeError, message);
   assertThrows(() => fg.register(false, "holdings"), TypeError, message);
   assertThrows(() => fg.register("foo", "holdings"), TypeError, message);
@@ -62,40 +62,40 @@
   let handler = {};
   let obj = {};
   let proxy = new Proxy(obj, handler);
-  let fg = new FinalizationGroup(() => {});
+  let fg = new FinalizationRegistry(() => {});
   fg.register(proxy);
 })();
 
 (function TestRegisterTargetAndHoldingsSameValue() {
-  let fg = new FinalizationGroup(() => {});
+  let fg = new FinalizationRegistry(() => {});
   let obj = {a: 1};
   // SameValue(target, holdings) not ok
   assertThrows(() => fg.register(obj, obj), TypeError,
-               "FinalizationGroup.prototype.register: target and holdings must not be same");
+               "FinalizationRegistry.prototype.register: target and holdings must not be same");
   let holdings = {a: 1};
   fg.register(obj, holdings);
 })();
 
-(function TestRegisterWithoutFinalizationGroup() {
-  assertThrows(() => FinalizationGroup.prototype.register.call({}, {}, "holdings"), TypeError);
+(function TestRegisterWithoutFinalizationRegistry() {
+  assertThrows(() => FinalizationRegistry.prototype.register.call({}, {}, "holdings"), TypeError);
   // Does not throw:
-  let fg = new FinalizationGroup(() => {});
-  FinalizationGroup.prototype.register.call(fg, {}, "holdings");
+  let fg = new FinalizationRegistry(() => {});
+  FinalizationRegistry.prototype.register.call(fg, {}, "holdings");
 })();
 
 (function TestUnregisterWithNonExistentKey() {
-  let fg = new FinalizationGroup(() => {});
+  let fg = new FinalizationRegistry(() => {});
   let success = fg.unregister({"k": "whatever"});
   assertFalse(success);
 })();
 
-(function TestUnregisterWithNonFinalizationGroup() {
-  assertThrows(() => FinalizationGroup.prototype.unregister.call({}, {}),
+(function TestUnregisterWithNonFinalizationRegistry() {
+  assertThrows(() => FinalizationRegistry.prototype.unregister.call({}, {}),
                TypeError);
 })();
 
 (function TestUnregisterWithNonObjectUnregisterToken() {
-  let fg = new FinalizationGroup(() => {});
+  let fg = new FinalizationRegistry(() => {});
   assertThrows(() => fg.unregister(1), TypeError);
   assertThrows(() => fg.unregister(1n), TypeError);
   assertThrows(() => fg.unregister('one'), TypeError);
@@ -149,16 +149,16 @@
   let wr = new WeakRef(proxy);
 })();
 
-(function TestCleanupSomeWithoutFinalizationGroup() {
-  assertThrows(() => FinalizationGroup.prototype.cleanupSome.call({}), TypeError);
+(function TestCleanupSomeWithoutFinalizationRegistry() {
+  assertThrows(() => FinalizationRegistry.prototype.cleanupSome.call({}), TypeError);
   // Does not throw:
-  let fg = new FinalizationGroup(() => {});
-  let rv = FinalizationGroup.prototype.cleanupSome.call(fg);
+  let fg = new FinalizationRegistry(() => {});
+  let rv = FinalizationRegistry.prototype.cleanupSome.call(fg);
   assertEquals(undefined, rv);
 })();
 
 (function TestCleanupSomeWithNonCallableCallback() {
-  let fg = new FinalizationGroup(() => {});
+  let fg = new FinalizationRegistry(() => {});
   assertThrows(() => fg.cleanupSome(1), TypeError);
   assertThrows(() => fg.cleanupSome(1n), TypeError);
   assertThrows(() => fg.cleanupSome(Symbol()), TypeError);
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-doesnt-iterate-all-holdings.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-doesnt-iterate-all-holdings.js
index ebc4ebf933..3f5133a87c 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-doesnt-iterate-all-holdings.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-doesnt-iterate-all-holdings.js
@@ -39,8 +39,8 @@ let cleanup = function(iter) {
   }
 }
 
-let fg = new FinalizationGroup(cleanup);
-// Create 3 objects and register them in the FinalizationGroup. The objects need
+let fg = new FinalizationRegistry(cleanup);
+// Create 3 objects and register them in the FinalizationRegistry. The objects need
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-from-different-realm.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-from-different-realm.js
index 97ab1dbd80..eac92486a0 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-from-different-realm.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-from-different-realm.js
@@ -9,9 +9,9 @@ let r = Realm.create();
 let cleanup = Realm.eval(r, "var stored_global; function cleanup() { stored_global = globalThis; } cleanup");
 let realm_global_this = Realm.eval(r, "globalThis");
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 
-// Create an object and a register it in the FinalizationGroup. The object needs
+// Create an object and a register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 let weak_cell;
 
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-is-not-a-microtask.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-is-not-a-microtask.js
index 077bc21e82..12282f7486 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-is-not-a-microtask.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-is-not-a-microtask.js
@@ -24,7 +24,7 @@ let cleanup = (iter) => {
   for (holdings of iter) { }
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let o = null;
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-on-detached-realm.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-on-detached-realm.js
index 9cc548920c..3513c8f211 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-on-detached-realm.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-on-detached-realm.js
@@ -6,18 +6,31 @@
 
 let cleanedUp = false;
 let r = Realm.create();
-let FG = Realm.eval(r, "FinalizationGroup");
+let FG = Realm.eval(r, "FinalizationRegistry");
 Realm.detachGlobal(r);
 
+let fg_not_run = new FG(() => {
+  assertUnreachable();
+});
+(() => {
+  fg_not_run.register({});
+})();
+
+gc();
+
+// Disposing the realm cancels the already scheduled fg_not_run's finalizer.
+Realm.dispose(r);
+
 let fg = new FG(()=> {
   cleanedUp = true;
 });
 
+// FGs that are alive after disposal can still schedule tasks.
 (() => {
   let object = {};
   fg.register(object, {});
 
-  // object goes out of scope.
+  // object becomes unreachable.
 })();
 
 gc();
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-proxy-from-different-realm.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-proxy-from-different-realm.js
index 1d275a19aa..f2374efc88 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-proxy-from-different-realm.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanup-proxy-from-different-realm.js
@@ -9,9 +9,9 @@ let r = Realm.create();
 let cleanup = Realm.eval(r, "var stored_global; let cleanup = new Proxy(function() { stored_global = globalThis;}, {}); cleanup");
 let realm_global_this = Realm.eval(r, "globalThis");
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 
-// Create an object and register it in the FinalizationGroup. The object needs
+// Create an object and register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 let weak_cell;
 
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-2.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-2.js
index 67ed64e85a..8e40fd6bbd 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-2.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-2.js
@@ -13,7 +13,7 @@ let cleanup = function(iter) {
   ++cleanup_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 (function() {
   let o = {};
   fg.register(o, "holdings");
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-after-unregister.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-after-unregister.js
index 363fc4a524..697c926a82 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-after-unregister.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome-after-unregister.js
@@ -13,7 +13,7 @@ let cleanup = function(iter) {
   ++cleanup_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "this is the key"};
 (function() {
   let o = {};
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome.js b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome.js
index 06eb292dac..f757bdbf7e 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/cleanupsome.js
@@ -17,7 +17,7 @@ let cleanup2 = function(iter) {
   ++cleanup_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 (function() {
   let o = {};
   fg.register(o, "holdings");
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/finalizationgroup-and-weakref.js b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-and-weakref
index 83de3a838b..144b56fce7 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/finalizationgroup-and-weakref.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-and-weakref
@@ -16,7 +16,7 @@ let cleanup = function(iter) {
   cleanup_called = true;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let weak_ref;
 (function() {
   let o = {};
@@ -25,7 +25,7 @@ let weak_ref;
 })();
 
 // Since the WeakRef was created during this turn, it is not cleared by GC. The
-// pointer inside the FinalizationGroup is not cleared either, since the WeakRef
+// pointer inside the FinalizationRegistry is not cleared either, since the WeakRef
 // keeps the target object alive.
 gc();
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-independent-lifetime.js b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-independent-lifetime.js
new file mode 100644
index 0000000000..732740f293
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-independent-lifetime.js
@@ -0,0 +1,26 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+
+let cleanup_called = false;
+function cleanup(iter) {
+  [...iter];
+  cleanup_called = true;
+};
+(function() {
+  let fg = new FinalizationRegistry(cleanup);
+  (function() {
+    let x = {};
+    fg.register(x, {});
+    x = null;
+  })();
+  // Schedule fg for cleanup.
+  gc();
+})();
+
+// Collect fg, which should result in cleanup not called.
+gc();
+
+setTimeout(function() { assertFalse(cleanup_called); }, 0);
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/finalization-group-keeps-holdings-alive.js b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-keeps-holdings-alive.js
index ea35a2e63f..d8c00fcff8 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/finalization-group-keeps-holdings-alive.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-keeps-holdings-alive.js
@@ -16,18 +16,23 @@ let cleanup = function(iter) {
   cleanup_called = true;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let o1 = {};
 let holdings = {'a': 'this is the holdings object'};
-fg.register(o1, holdings);
+
+// Ignition holds references to objects in temporary registers. These will be
+// released when the function exits. So only access o inside a function to
+// prevent any references to objects in temporary registers when a gc is
+// triggered.
+(() => {fg.register(o1, holdings);})()
 
 gc();
 assertFalse(cleanup_called);
 
 // Drop the last references to o1.
-o1 = null;
+(() => {o1 = null;})()
 
-// Drop the last reference to the holdings. The FinalizationGroup keeps it
+// Drop the last reference to the holdings. The FinalizationRegistry keeps it
 // alive, so the cleanup function will be called as normal.
 holdings = null;
 gc();
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/finalizationgroup-scheduled-for-cleanup-multiple-times.js b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-scheduled-for-cleanup-multiple-times.js
index a1cff3aaa0..de25bbe425 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/finalizationgroup-scheduled-for-cleanup-multiple-times.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/finalizationregistry-scheduled-for-cleanup-multiple-times.js
@@ -25,10 +25,10 @@ let cleanup1 = function(iter) {
   ++cleanup1_call_count;
 }
 
-let fg0 = new FinalizationGroup(cleanup0);
-let fg1 = new FinalizationGroup(cleanup1);
+let fg0 = new FinalizationRegistry(cleanup0);
+let fg1 = new FinalizationRegistry(cleanup1);
 
-// Register 1 weak reference for each FinalizationGroup and kill the objects they point to.
+// Register 1 weak reference for each FinalizationRegistry and kill the objects they point to.
 (function() {
   // The objects need to be inside a closure so that we can reliably kill them.
   let objects = [];
@@ -40,13 +40,13 @@ let fg1 = new FinalizationGroup(cleanup1);
 
   // Drop the references to the objects.
   objects = [];
-
-  // Will schedule both fg0 and fg1 for cleanup.
-  gc();
 })();
 
+// Will schedule both fg0 and fg1 for cleanup.
+gc();
+
 // Before the cleanup task has a chance to run, do the same thing again, so both
-// FinalizationGroups are (again) scheduled for cleanup. This has to be a IIFE function
+// FinalizationRegistries are (again) scheduled for cleanup. This has to be a IIFE function
 // (so that we can reliably kill the objects) so we cannot use the same function
 // as before.
 (function() {
@@ -56,9 +56,10 @@ let fg1 = new FinalizationGroup(cleanup1);
   fg0.register(objects[0], "holdings0-1");
   fg1.register(objects[1], "holdings1-1");
   objects = [];
-  gc();
 })();
 
+gc();
+
 let timeout_func = function() {
   assertEquals(1, cleanup0_call_count);
   assertEquals(2, cleanup0_holdings_count);
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/iterating-in-cleanup.js b/deps/v8/test/mjsunit/harmony/weakrefs/iterating-in-cleanup.js
index 73aac76378..c591b44a54 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/iterating-in-cleanup.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/iterating-in-cleanup.js
@@ -21,18 +21,27 @@ let cleanup = function(iter) {
   cleanup_called = true;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let o1 = {};
 let o2 = {};
-fg.register(o1, 1);
-fg.register(o2, 2);
+
+// Ignition holds references to objects in temporary registers. These will be
+// released when the function exits. So only access o inside a function to
+// prevent any references to objects in temporary registers when a gc is
+(function() {
+  fg.register(o1, 1);
+  fg.register(o2, 2);
+})();
 
 gc();
 assertFalse(cleanup_called);
 
 // Drop the last references to o1 and o2.
-o1 = null;
-o2 = null;
+(function() {
+  o1 = null;
+  o2 = null;
+})();
+
 // GC will reclaim the target objects; the cleanup function will be called the
 // next time we enter the event loop.
 gc();
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/multiple-dirty-finalization-groups.js b/deps/v8/test/mjsunit/harmony/weakrefs/multiple-dirty-finalization-groups.js
index 51e721401a..fec0ab5b57 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/multiple-dirty-finalization-groups.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/multiple-dirty-finalization-groups.js
@@ -13,10 +13,10 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg1 = new FinalizationGroup(cleanup);
-let fg2 = new FinalizationGroup(cleanup);
+let fg1 = new FinalizationRegistry(cleanup);
+let fg2 = new FinalizationRegistry(cleanup);
 
-// Create two objects and register them in FinalizationGroups. The objects need
+// Create two objects and register them in FinalizationRegistries. The objects need
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/reentrant-gc-from-cleanup.js b/deps/v8/test/mjsunit/harmony/weakrefs/reentrant-gc-from-cleanup.js
new file mode 100644
index 0000000000..09854f0556
--- /dev/null
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/reentrant-gc-from-cleanup.js
@@ -0,0 +1,25 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+
+let call_count = 0;
+let reentrant_gc =
+    function(iter) {
+  [...iter];
+  gc();
+  call_count++;
+}
+
+let fg = new FinalizationRegistry(reentrant_gc);
+
+(function() {
+fg.register({}, 42);
+})();
+
+gc();
+
+setTimeout(function() {
+  assertEquals(1, call_count);
+}, 0);
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/undefined-holdings.js b/deps/v8/test/mjsunit/harmony/weakrefs/undefined-holdings.js
index ac3dc6041a..7c09cf5985 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/undefined-holdings.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/undefined-holdings.js
@@ -14,9 +14,9 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 
-// Create an object and register it in the FinalizationGroup. The object needs to be inside
+// Create an object and register it in the FinalizationRegistry. The object needs to be inside
 // a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-after-cleanup.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-after-cleanup.js
index 3db18e016e..e8a7843c71 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-after-cleanup.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-after-cleanup.js
@@ -14,9 +14,9 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "this is the key"};
-// Create an object and register it in the FinalizationGroup. The object needs
+// Create an object and register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-before-cleanup.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-before-cleanup.js
index c54dbb25de..ff576b4dfe 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-before-cleanup.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-before-cleanup.js
@@ -9,9 +9,9 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "this is the key"};
-// Create an object and register it in the FinalizationGroup. The object needs
+// Create an object and register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-called-twice.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-called-twice.js
index d1dd8f8b75..e7604eecec 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-called-twice.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-called-twice.js
@@ -9,9 +9,9 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "this is the key"};
-// Create an object and register it in the FinalizationGroup. The object needs
+// Create an object and register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup1.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup1.js
index 80ca85f619..a62e6ed923 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup1.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup1.js
@@ -17,9 +17,9 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "the key"};
-// Create an object and register it in the FinalizationGroup. The object needs
+// Create an object and register it in the FinalizationRegistry. The object needs
 // to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup2.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup2.js
index 038f5093e1..e26d9a1921 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup2.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup2.js
@@ -17,8 +17,8 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
-// Create an object and register it in the FinalizationGroup. The object needs to be inside
+let fg = new FinalizationRegistry(cleanup);
+// Create an object and register it in the FinalizationRegistry. The object needs to be inside
 // a closure so that we can reliably kill them!
 let key = {"k": "this is the key"};
 
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup3.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup3.js
index af6b5c13ed..8f28673205 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup3.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup3.js
@@ -17,10 +17,10 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key = {"k": "this is the key"};
 
-// Create an object and register it in the FinalizationGroup. The object needs to be inside
+// Create an object and register it in the FinalizationRegistry. The object needs to be inside
 // a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup4.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup4.js
index 8a0a5d5707..a7ab9d18df 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup4.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup4.js
@@ -22,10 +22,10 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key1 = {"k": "first key"};
 let key2 = {"k": "second key"};
-// Create two objects and register them in the FinalizationGroup. The objects
+// Create two objects and register them in the FinalizationRegistry. The objects
 // need to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup5.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup5.js
index 974485e9cb..30926d1d56 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup5.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-inside-cleanup5.js
@@ -21,8 +21,8 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
-// Create an object and register it in the FinalizationGroup. The object needs to be inside
+let fg = new FinalizationRegistry(cleanup);
+// Create an object and register it in the FinalizationRegistry. The object needs to be inside
 // a closure so that we can reliably kill them!
 let key = {"k": "this is the key"};
 
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-many.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-many.js
index 8be0db1444..3512fc9217 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-many.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-many.js
@@ -14,10 +14,10 @@ let cleanup = function(iter) {
   ++cleanup_call_count;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let key1 = {"k": "key1"};
 let key2 = {"k": "key2"};
-// Create three objects and register them in the FinalizationGroup. The objects
+// Create three objects and register them in the FinalizationRegistry. The objects
 // need to be inside a closure so that we can reliably kill them!
 
 (function() {
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-when-cleanup-already-scheduled.js b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-when-cleanup-already-scheduled.js
index 4ad4425a4c..5117997965 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/unregister-when-cleanup-already-scheduled.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/unregister-when-cleanup-already-scheduled.js
@@ -10,8 +10,8 @@ let cleanup = function(iter) {
 }
 
 let key = {"k": "this is my key"};
-let fg = new FinalizationGroup(cleanup);
-// Create an object and register it in the FinalizationGroup. The object needs to be inside
+let fg = new FinalizationRegistry(cleanup);
+// Create an object and register it in the FinalizationRegistry. The object needs to be inside
 // a closure so that we can reliably kill them!
 
 (function() {
@@ -25,7 +25,7 @@ let fg = new FinalizationGroup(cleanup);
 gc();
 assertEquals(0, cleanup_call_count);
 
-// Unregister the object from the FinalizationGroup before cleanup has ran.
+// Unregister the object from the FinalizationRegistry before cleanup has ran.
 let success = fg.unregister(key);
 assertTrue(success);
 
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/weak-cell-basics.js b/deps/v8/test/mjsunit/harmony/weakrefs/weak-cell-basics.js
index 170a52df10..f3480f78d1 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/weak-cell-basics.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/weak-cell-basics.js
@@ -15,16 +15,22 @@ let cleanup = function(iter) {
   cleanup_called = true;
 }
 
-let fg = new FinalizationGroup(cleanup);
+let fg = new FinalizationRegistry(cleanup);
 let o = {};
 let holdings = {'h': 55};
-fg.register(o, holdings);
+
+// Ignition holds references to objects in temporary registers. These will be
+// released when the function exits. So only access o inside a function to
+// prevent any references to objects in temporary registers when a gc is
+// triggered.
+(() => { fg.register(o, holdings); })()
 
 gc();
 assertFalse(cleanup_called);
 
 // Drop the last reference to o.
-o = null;
+(() => { o = null; })()
+
 // GC will clear the WeakCell; the cleanup function will be called the next time
 // we enter the event loop.
 gc();
diff --git a/deps/v8/test/mjsunit/harmony/weakrefs/weak-unregistertoken.js b/deps/v8/test/mjsunit/harmony/weakrefs/weak-unregistertoken.js
index 8fdc803c56..94f5ce6a90 100644
--- a/deps/v8/test/mjsunit/harmony/weakrefs/weak-unregistertoken.js
+++ b/deps/v8/test/mjsunit/harmony/weakrefs/weak-unregistertoken.js
@@ -4,7 +4,7 @@
 
 // Flags: --harmony-weak-refs --expose-gc --noincremental-marking
 
-var FG = new FinalizationGroup (function (iter) { globalThis.FGRan = true; });
+var FG = new FinalizationRegistry (function (iter) { globalThis.FRRan = true; });
 {
   let obj = {};
   // obj is its own unregister token and becomes unreachable after this
@@ -14,7 +14,7 @@ var FG = new FinalizationGroup (function (iter) { globalThis.FGRan = true; });
 }
 function tryAgain() {
   gc();
-  if (globalThis.FGRan || FG.cleanupSome()) {
+  if (globalThis.FRRan || FG.cleanupSome()) {
     return;
   }
   setTimeout(tryAgain, 0);
diff --git a/deps/v8/test/mjsunit/mjsunit.js b/deps/v8/test/mjsunit/mjsunit.js
index fd45ebacbd..58dcd6c9ed 100644
--- a/deps/v8/test/mjsunit/mjsunit.js
+++ b/deps/v8/test/mjsunit/mjsunit.js
@@ -548,13 +548,14 @@ var prettyPrinted;
   assertInstanceof = function assertInstanceof(obj, type) {
     if (!(obj instanceof type)) {
       var actualTypeName = null;
-      var actualConstructor = Object.getPrototypeOf(obj).constructor;
-      if (typeof actualConstructor === "function") {
+      var actualConstructor = obj && Object.getPrototypeOf(obj).constructor;
+      if (typeof actualConstructor === 'function') {
         actualTypeName = actualConstructor.name || String(actualConstructor);
       }
-      failWithMessage("Object <" + prettyPrinted(obj) + "> is not an instance of <" +
-               (type.name || type) + ">" +
-               (actualTypeName ? " but of <" + actualTypeName + ">" : ""));
+      failWithMessage(
+          'Object <' + prettyPrinted(obj) + '> is not an instance of <' +
+          (type.name || type) + '>' +
+          (actualTypeName ? ' but of <' + actualTypeName + '>' : ''));
     }
   };
 
diff --git a/deps/v8/test/mjsunit/mjsunit.status b/deps/v8/test/mjsunit/mjsunit.status
index dd3b2dcb87..989c097908 100644
--- a/deps/v8/test/mjsunit/mjsunit.status
+++ b/deps/v8/test/mjsunit/mjsunit.status
@@ -62,11 +62,8 @@
   # Issue 9380: Memory leaks of shared WebAssembly.Memory objects
   'wasm/shared-memory-worker-gc': [SKIP],
 
-  # crbug.com/v8/10120: This test is meant to pass (only) in no_i18n builds,
-  # but currently doesn't:
-  'es6/unicode-regexp-ignore-case-noi18n': [FAIL],
-  # Once the bug is fixed, the expectations should be:
-  # 'es6/unicode-regexp-ignore-case-noi18n': [PASS, ['no_i18n == False', FAIL]],
+  # BUG(v8:10197)
+  'regress/regress-748069': [SKIP],
 
   ##############################################################################
   # Tests where variants make no sense.
@@ -158,6 +155,10 @@
   # Predictable tests fail due to race between postMessage and GrowMemory
   'regress/wasm/regress-1010272': [PASS, NO_VARIANTS, ['system == android', SKIP], ['predictable', SKIP]],
 
+  # Only makes sense in the no_i18n variant.
+  'es6/unicode-regexp-ignore-case-noi18n':
+      [['no_i18n == True', PASS], ['no_i18n == False', FAIL]],
+
   # Needs to be adapted after changes to Function constructor. chromium:1065094
   'cross-realm-filtering': [SKIP],
 }],  # ALWAYS
@@ -309,6 +310,7 @@
   'regress/regress-crbug-772056': [SKIP],
   'regress/regress-crbug-816961': [SKIP],
   'regress/regress-crbug-969498': [SKIP],
+  'regress/regress-crbug-1047368': [SKIP],
   'regress/wasm/*': [SKIP],
   'regress/regress-8947': [SKIP],
   'regress/regress-9165': [SKIP],
@@ -382,16 +384,17 @@
 
 ##############################################################################
 ['no_i18n', {
-  # case-insensitive unicode regexp relies on case mapping provided by ICU.
+  # Case-insensitive unicode regexp relies on case mapping provided by ICU.
   'es6/unicode-regexp-ignore-case': [FAIL],
   'regress/regress-5036': [FAIL],
   'es7/regexp-ui-word': [FAIL],
   'regexp-modifiers-i18n': [FAIL],
   'regexp-modifiers-autogenerated-i18n': [FAIL],
-  # desugaring regexp property class relies on ICU.
-  'harmony/regexp-property-*': [FAIL],
-  'harmony/regexp-property-invalid': [PASS],
-  'regress/regress-793588': [FAIL],
+
+  # Desugaring regexp property class relies on ICU. Anything goes as long as we
+  # don't crash.
+  'harmony/regexp-property-*': [PASS,FAIL],
+  'regress/regress-793588': [PASS,FAIL],
 
   # noi18n build cannot parse characters in supplementary plane.
   'harmony/regexp-named-captures': [FAIL],
@@ -431,6 +434,7 @@
 # 32-bit platforms
 ['arch in (ia32, arm, mips, mipsel)', {
   # Needs >2GB of available contiguous memory.
+  'wasm/grow-huge-memory': [SKIP],
   'wasm/huge-memory': [SKIP],
   'wasm/huge-typedarray': [SKIP],
 }],  # 'arch in (ia32, arm, mips, mipsel)'
@@ -796,6 +800,7 @@
   # OOM:
   'regress/regress-752764': [FAIL],
   # Flaky OOM:
+  'regress/regress-748069': [SKIP],
   'regress/regress-779407': [SKIP],
   'regress/regress-852258': [SKIP],
 }],  # 'system == android'
@@ -848,6 +853,8 @@
   'compiler/serializer-dead-after-jump': [SKIP],
   'compiler/serializer-dead-after-return': [SKIP],
   'compiler/serializer-transition-propagation': [SKIP],
+  'regress/regress-1049982-1': [SKIP],
+  'regress/regress-1049982-2': [SKIP],
 
   # Bounds check triggers forced deopt for array constructors.
   'array-constructor-feedback': [SKIP],
@@ -858,9 +865,6 @@
   # Forced optimisation path tests.
   'shared-function-tier-up-turbo': [SKIP],
 
-  # Fails deopt_fuzzer due to --deopt_every_n_times
-  'es6/array-iterator-turbo': [SKIP],
-
   # Too slow tests.
   'regress/regress-740784': [SKIP],
 
@@ -983,7 +987,6 @@
 ['variant == stress', {
   # Slow tests.
   'array-natives-elements': [SKIP],
-  'es6/array-iterator-turbo': [SKIP],
   'ignition/regress-599001-verifyheap': [SKIP],
   'unicode-test': [SKIP],
 
@@ -1127,9 +1130,13 @@
   'compiler/serializer-transition-propagation': [SKIP],
 
   # Some tests rely on inlining.
+  'compiler/inlined-call-polymorphic': [SKIP],
   'compiler/opt-higher-order-functions': [SKIP],
   'regress/regress-1049982-1': [SKIP],
   'regress/regress-1049982-2': [SKIP],
+
+  # interrupt_budget overrides don't work with TurboProp.
+  'interrupt-budget-override': [SKIP],
 }],  # variant == turboprop
 
 ##############################################################################
@@ -1145,4 +1152,12 @@
   'wasm/many-modules': [SKIP],
 }],  # variant == stress_js_bg_compile_wasm_code_gc
 
+##############################################################################
+['variant == assert_types', {
+  # Type assertions can lead to differences in representation selection,
+  # which in turn can lead to different deopt behavior.
+  'compiler/number-abs': [SKIP],
+  'compiler/number-toboolean': [SKIP],
+}],  # variant == assert_types
+
 ]
diff --git a/deps/v8/test/mjsunit/non-extensible-array-reduce.js b/deps/v8/test/mjsunit/non-extensible-array-reduce.js
index 1bc87b7add..c90407fa4c 100644
--- a/deps/v8/test/mjsunit/non-extensible-array-reduce.js
+++ b/deps/v8/test/mjsunit/non-extensible-array-reduce.js
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --allow-natives-syntax --opt --no-always-opt --no-lazy-feedback-allocation
 
-/**
- * @fileoverview Test reduce and reduceRight
- */
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 function clone(v) {
   // Shallow-copies arrays, returns everything else verbatim.
diff --git a/deps/v8/test/mjsunit/optimized-array-every.js b/deps/v8/test/mjsunit/optimized-array-every.js
index 30578c55f0..57f2fa6f19 100644
--- a/deps/v8/test/mjsunit/optimized-array-every.js
+++ b/deps/v8/test/mjsunit/optimized-array-every.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --turbo-inline-array-builtins --opt
-// Flags: --no-always-opt
+// Flags: --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 // Early exit from every functions properly.
 (() => {
diff --git a/deps/v8/test/mjsunit/optimized-array-find.js b/deps/v8/test/mjsunit/optimized-array-find.js
index b8f3baa28c..9ca2f09b22 100644
--- a/deps/v8/test/mjsunit/optimized-array-find.js
+++ b/deps/v8/test/mjsunit/optimized-array-find.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --turbo-inline-array-builtins --opt
-// Flags: --no-always-opt
+// Flags: --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 // Unknown field access leads to soft-deopt unrelated to find, should still
 // lead to correct result.
diff --git a/deps/v8/test/mjsunit/optimized-array-findindex.js b/deps/v8/test/mjsunit/optimized-array-findindex.js
index 299ae0a2bf..d0b69e646e 100644
--- a/deps/v8/test/mjsunit/optimized-array-findindex.js
+++ b/deps/v8/test/mjsunit/optimized-array-findindex.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --turbo-inline-array-builtins --opt
-// Flags: --no-always-opt
+// Flags: --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 // Unknown field access leads to soft-deopt unrelated to findIndex, should still
 // lead to correct result.
diff --git a/deps/v8/test/mjsunit/optimized-array-some.js b/deps/v8/test/mjsunit/optimized-array-some.js
index 73862702a2..ede0449244 100644
--- a/deps/v8/test/mjsunit/optimized-array-some.js
+++ b/deps/v8/test/mjsunit/optimized-array-some.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --turbo-inline-array-builtins --opt
-// Flags: --no-always-opt
+// Flags: --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 // Early exit from some functions properly.
 (() => {
diff --git a/deps/v8/test/mjsunit/optimized-filter.js b/deps/v8/test/mjsunit/optimized-filter.js
index 97eb1f2378..e14ed69e6f 100644
--- a/deps/v8/test/mjsunit/optimized-filter.js
+++ b/deps/v8/test/mjsunit/optimized-filter.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --expose-gc --turbo-inline-array-builtins
-// Flags: --opt --no-always-opt
+// Flags: --opt --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 // Unknown field access leads to soft-deopt unrelated to filter, should still
 // lead to correct result.
diff --git a/deps/v8/test/mjsunit/optimized-foreach.js b/deps/v8/test/mjsunit/optimized-foreach.js
index 3f39d3cd2e..c114f54f55 100644
--- a/deps/v8/test/mjsunit/optimized-foreach.js
+++ b/deps/v8/test/mjsunit/optimized-foreach.js
@@ -3,6 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --expose-gc --turbo-inline-array-builtins
+// Flags: --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 var a = [
   0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13,
diff --git a/deps/v8/test/mjsunit/optimized-map.js b/deps/v8/test/mjsunit/optimized-map.js
index 1095f7baf2..9893428576 100644
--- a/deps/v8/test/mjsunit/optimized-map.js
+++ b/deps/v8/test/mjsunit/optimized-map.js
@@ -3,7 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --expose-gc --turbo-inline-array-builtins
-// Flags: --opt --no-always-opt
+// Flags: --opt --no-always-opt --no-lazy-feedback-allocation
+
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 var a = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,0,0];
 var b = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25];
diff --git a/deps/v8/test/mjsunit/prepare-missing-label-syntax-error.js b/deps/v8/test/mjsunit/prepare-missing-label-syntax-error.js
new file mode 100644
index 0000000000..9aa13aa8fe
--- /dev/null
+++ b/deps/v8/test/mjsunit/prepare-missing-label-syntax-error.js
@@ -0,0 +1,8 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+assertThrows("function f() { break }", SyntaxError);
+assertThrows("function f() { break a }", SyntaxError);
+assertThrows("function f() { continue }", SyntaxError);
+assertThrows("function f() { continue a }", SyntaxError);
diff --git a/deps/v8/test/mjsunit/regexp.js b/deps/v8/test/mjsunit/regexp.js
index 0cad7e7164..e652525914 100644
--- a/deps/v8/test/mjsunit/regexp.js
+++ b/deps/v8/test/mjsunit/regexp.js
@@ -25,6 +25,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// Flags: --allow-natives-syntax
+
 function testEscape(str, regex) {
   assertEquals("foo:bar:baz", str.split(regex).join(":"));
 }
@@ -835,3 +837,13 @@ assertEquals("[/]]", /[/]]/.source);
 assertEquals("[[/]]", /[[/]]/.source);
 assertEquals("[[\\/]", /[[\/]/.source);
 assertEquals("[[\\/]]", /[[\/]]/.source);
+assertEquals("\\n", new RegExp("\\\n").source);
+assertEquals("\\r", new RegExp("\\\r").source);
+assertEquals("\\u2028", new RegExp("\\\u2028").source);
+assertEquals("\\u2029", new RegExp("\\\u2029").source);
+
+{
+  // No escapes needed, the original string should be reused as `.source`.
+  const pattern = "\\n";
+  assertTrue(%ReferenceEqual(pattern, new RegExp(pattern).source));
+}
diff --git a/deps/v8/test/mjsunit/regress/regress-1049982-1.js b/deps/v8/test/mjsunit/regress/regress-1049982-1.js
index dd170386db..8400646ecb 100644
--- a/deps/v8/test/mjsunit/regress/regress-1049982-1.js
+++ b/deps/v8/test/mjsunit/regress/regress-1049982-1.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --opt
 
 const xs = [1,2,3,4,5,6,7,8,9];
 let deopt = false;
diff --git a/deps/v8/test/mjsunit/regress/regress-1049982-2.js b/deps/v8/test/mjsunit/regress/regress-1049982-2.js
index 90e96b8d5b..d7fe4a5f3a 100644
--- a/deps/v8/test/mjsunit/regress/regress-1049982-2.js
+++ b/deps/v8/test/mjsunit/regress/regress-1049982-2.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --opt
 
 const xs = [1,2,3,4,5,6,7,8,9];
 let deopt = false;
diff --git a/deps/v8/test/mjsunit/regress-906893.js b/deps/v8/test/mjsunit/regress/regress-906893.js
index 981b5824cb..981b5824cb 100644
--- a/deps/v8/test/mjsunit/regress-906893.js
+++ b/deps/v8/test/mjsunit/regress/regress-906893.js
diff --git a/deps/v8/test/mjsunit/regress-918763.js b/deps/v8/test/mjsunit/regress/regress-918763.js
index 2e70536a18..2e70536a18 100644
--- a/deps/v8/test/mjsunit/regress-918763.js
+++ b/deps/v8/test/mjsunit/regress/regress-918763.js
diff --git a/deps/v8/test/mjsunit/regress-930045.js b/deps/v8/test/mjsunit/regress/regress-930045.js
index 8983c2014a..8983c2014a 100644
--- a/deps/v8/test/mjsunit/regress-930045.js
+++ b/deps/v8/test/mjsunit/regress/regress-930045.js
diff --git a/deps/v8/test/mjsunit/regress-932101.js b/deps/v8/test/mjsunit/regress/regress-932101.js
index 720ee11fef..720ee11fef 100644
--- a/deps/v8/test/mjsunit/regress-932101.js
+++ b/deps/v8/test/mjsunit/regress/regress-932101.js
diff --git a/deps/v8/test/mjsunit/regress-952682.js b/deps/v8/test/mjsunit/regress/regress-952682.js
index dd0e687bf0..dd0e687bf0 100644
--- a/deps/v8/test/mjsunit/regress-952682.js
+++ b/deps/v8/test/mjsunit/regress/regress-952682.js
diff --git a/deps/v8/test/mjsunit/regress-956426.js b/deps/v8/test/mjsunit/regress/regress-956426.js
index 93ccd7d36d..93ccd7d36d 100644
--- a/deps/v8/test/mjsunit/regress-956426.js
+++ b/deps/v8/test/mjsunit/regress/regress-956426.js
diff --git a/deps/v8/test/mjsunit/regress-958725.js b/deps/v8/test/mjsunit/regress/regress-958725.js
index bb0bd11055..bb0bd11055 100644
--- a/deps/v8/test/mjsunit/regress-958725.js
+++ b/deps/v8/test/mjsunit/regress/regress-958725.js
diff --git a/deps/v8/test/mjsunit/regress-963346.js b/deps/v8/test/mjsunit/regress/regress-963346.js
index 8f29556210..8f29556210 100644
--- a/deps/v8/test/mjsunit/regress-963346.js
+++ b/deps/v8/test/mjsunit/regress/regress-963346.js
diff --git a/deps/v8/test/mjsunit/regress-966460.js b/deps/v8/test/mjsunit/regress/regress-966460.js
index 8acf49b5a5..8acf49b5a5 100644
--- a/deps/v8/test/mjsunit/regress-966460.js
+++ b/deps/v8/test/mjsunit/regress/regress-966460.js
diff --git a/deps/v8/test/mjsunit/regress-crbug-1025468.js b/deps/v8/test/mjsunit/regress/regress-crbug-1025468.js
index bbfe72c4c0..bbfe72c4c0 100644
--- a/deps/v8/test/mjsunit/regress-crbug-1025468.js
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-1025468.js
diff --git a/deps/v8/test/mjsunit/regress/regress-crbug-1047368.js b/deps/v8/test/mjsunit/regress/regress-crbug-1047368.js
new file mode 100644
index 0000000000..800cf61879
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-1047368.js
@@ -0,0 +1,14 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Flags: --wasm-staging
+
+new WebAssembly.Function({
+    parameters: [],
+    results: []
+  }, x => x);
+const long_variable = {
+  toString: () => {
+  }
+};
diff --git a/deps/v8/test/mjsunit/regress/regress-crbug-1057653.js b/deps/v8/test/mjsunit/regress/regress-crbug-1057653.js
new file mode 100644
index 0000000000..343e72367a
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-1057653.js
@@ -0,0 +1,8 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+Object.prototype.length = 3642395160;
+const array = new Float32Array(2**27);
+
+assertThrows(() => {for (const key in array) {}}, RangeError);
diff --git a/deps/v8/test/mjsunit/regress/regress-crbug-1059738.js b/deps/v8/test/mjsunit/regress/regress-crbug-1059738.js
new file mode 100644
index 0000000000..1b10bb4213
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-1059738.js
@@ -0,0 +1,5 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+var o = {4294967295: ({4294967295: NaN}) + "foo"};
diff --git a/deps/v8/test/mjsunit/regress/regress-crbug-1072947.js b/deps/v8/test/mjsunit/regress/regress-crbug-1072947.js
new file mode 100644
index 0000000000..6a7518a46c
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-crbug-1072947.js
@@ -0,0 +1,31 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(function() {
+  class reg extends RegExp {}
+
+  let r;
+  function trigger() {
+    try {
+      trigger();
+    } catch {
+      Reflect.construct(RegExp,[],reg);
+    }
+  }
+  trigger();
+})();
+
+(function() {
+  class reg extends Function {}
+
+  let r;
+  function trigger() {
+    try {
+      trigger();
+    } catch {
+      Reflect.construct(RegExp,[],reg);
+    }
+  }
+  trigger();
+})();
diff --git a/deps/v8/test/mjsunit/regress-regexp-functional-replace-slow.js b/deps/v8/test/mjsunit/regress/regress-regexp-functional-replace-slow.js
index 033bcee1ef..033bcee1ef 100644
--- a/deps/v8/test/mjsunit/regress-regexp-functional-replace-slow.js
+++ b/deps/v8/test/mjsunit/regress/regress-regexp-functional-replace-slow.js
diff --git a/deps/v8/test/mjsunit/regress-v8-8445-2.js b/deps/v8/test/mjsunit/regress/regress-v8-8445-2.js
index a6145805d3..a6145805d3 100644
--- a/deps/v8/test/mjsunit/regress-v8-8445-2.js
+++ b/deps/v8/test/mjsunit/regress/regress-v8-8445-2.js
diff --git a/deps/v8/test/mjsunit/regress-v8-8445.js b/deps/v8/test/mjsunit/regress/regress-v8-8445.js
index 1bed026d42..1bed026d42 100644
--- a/deps/v8/test/mjsunit/regress-v8-8445.js
+++ b/deps/v8/test/mjsunit/regress/regress-v8-8445.js
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-10126-streaming.js b/deps/v8/test/mjsunit/regress/wasm/regress-10126-streaming.js
new file mode 100644
index 0000000000..bb6df82f55
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-10126-streaming.js
@@ -0,0 +1,7 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --wasm-test-streaming
+
+load('test/mjsunit/regress/wasm/regress-10126.js')
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-10126.js b/deps/v8/test/mjsunit/regress/wasm/regress-10126.js
new file mode 100644
index 0000000000..4985dfedb7
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-10126.js
@@ -0,0 +1,32 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load('test/mjsunit/wasm/wasm-module-builder.js')
+
+let binary = new Binary;
+binary.emit_bytes([
+  kWasmH0,              //  0 header
+  kWasmH1,              //  1 -
+  kWasmH2,              //  2 -
+  kWasmH3,              //  3 -
+  kWasmV0,              //  4 version
+  kWasmV1,              //  5 -
+  kWasmV2,              //  6 -
+  kWasmV3,              //  7 -
+  kUnknownSectionCode,  //  8 custom section
+  0x5,                  //  9 length
+  0x6,                  // 10 invalid name length
+  'a',                  // 11 payload
+  'b',                  // 12 -
+  'c',                  // 13 -
+  'd',                  // 14 -
+  kCodeSectionCode,     // 15 code section start
+  0x1,                  // 16 code section length
+  19,                   // 17 invalid number of functions
+]);
+
+const buffer = binary.trunc_buffer();
+assertThrowsAsync(
+    WebAssembly.compile(buffer), WebAssembly.CompileError,
+    'WebAssembly.compile(): expected 6 bytes, fell off end @+11');
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-10309.js b/deps/v8/test/mjsunit/regress/wasm/regress-10309.js
new file mode 100644
index 0000000000..ce73b783ef
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-10309.js
@@ -0,0 +1,64 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --experimental-wasm-simd
+
+let registry = {};
+
+function module(bytes, valid = true) {
+  let buffer = new ArrayBuffer(bytes.length);
+  let view = new Uint8Array(buffer);
+  for (let i = 0; i < bytes.length; ++i) {
+    view[i] = bytes.charCodeAt(i);
+  }
+  let validated;
+  try {
+    validated = WebAssembly.validate(buffer);
+  } catch (e) {
+    throw new Error("Wasm validate throws");
+  }
+  if (validated !== valid) {
+    throw new Error("Wasm validate failure" + (valid ? "" : " expected"));
+  }
+  return new WebAssembly.Module(buffer);
+}
+
+function instance(bytes, imports = registry) {
+  return new WebAssembly.Instance(module(bytes), imports);
+}
+
+function call(instance, name, args) {
+  return instance.exports[name](...args);
+}
+
+function exports(name, instance) {
+  return {[name]: instance.exports};
+}
+
+function assert_return(action, expected) {
+  let actual = action();
+  if (!Object.is(actual, expected)) {
+    throw new Error("Wasm return value " + expected + " expected, got " + actual);
+  };
+}
+
+let f32 = Math.fround;
+
+// simple.wast:1
+let $1 = instance("\x00\x61\x73\x6d\x01\x00\x00\x00\x01\x09\x02\x60\x00\x00\x60\x01\x7f\x01\x7d\x03\x04\x03\x00\x00\x01\x05\x03\x01\x00\x01\x07\x1c\x02\x11\x72\x65\x70\x6c\x61\x63\x65\x5f\x6c\x61\x6e\x65\x5f\x74\x65\x73\x74\x00\x01\x04\x72\x65\x61\x64\x00\x02\x08\x01\x00\x0a\x6e\x03\x2a\x00\x41\x10\x43\x00\x00\x80\x3f\x38\x02\x00\x41\x14\x43\x00\x00\x00\x40\x38\x02\x00\x41\x18\x43\x00\x00\x40\x40\x38\x02\x00\x41\x1c\x43\x00\x00\x80\x40\x38\x02\x00\x0b\x39\x01\x01\x7b\x41\x10\x2a\x02\x00\xfd\x12\x21\x00\x20\x00\x41\x10\x2a\x01\x04\xfd\x14\x01\x21\x00\x20\x00\x41\x10\x2a\x01\x08\xfd\x14\x02\x21\x00\x20\x00\x41\x10\x2a\x01\x0c\xfd\x14\x03\x21\x00\x41\x00\x20\x00\xfd\x01\x02\x00\x0b\x07\x00\x20\x00\x2a\x02\x00\x0b");
+
+// simple.wast:49
+call($1, "replace_lane_test", []);
+
+// simple.wast:50
+assert_return(() => call($1, "read", [0]), f32(1.0));
+
+// simple.wast:51
+assert_return(() => call($1, "read", [4]), f32(2.0));
+
+// simple.wast:52
+assert_return(() => call($1, "read", [8]), f32(3.0));
+
+// simple.wast:53
+assert_return(() => call($1, "read", [12]), f32(4.0));
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1045225.js b/deps/v8/test/mjsunit/regress/wasm/regress-1045225.js
new file mode 100644
index 0000000000..3ac81f5485
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1045225.js
@@ -0,0 +1,28 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --wasm-staging
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+(function() {
+  const builder = new WasmModuleBuilder();
+  builder.addMemory(16, 32, false, true);
+  builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
+  // Generate function 1 (out of 1).
+  builder.addFunction(undefined, 0 /* sig */)
+    .addBodyWithEnd([
+// signature: i_iii
+// body:
+kExprI32Const, 0x80, 0x01,
+kExprI32Clz,
+kExprI32Const, 0x00,
+kExprI64Const, 0x00,
+kAtomicPrefix, kExprI64AtomicStore8U, 0x00, 0x00,
+kExprEnd,   // @13
+            ]);
+  builder.addExport('main', 0);
+  const instance = builder.instantiate();
+  print(instance.exports.main(1, 2, 3));
+})();
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1046472.js b/deps/v8/test/mjsunit/regress/wasm/regress-1046472.js
new file mode 100644
index 0000000000..056006b926
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1046472.js
@@ -0,0 +1,33 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --liftoff --no-wasm-tier-up --wasm-staging
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+(function() {
+  const builder = new WasmModuleBuilder();
+  builder.addMemory(16, 32, false);
+  builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
+  // Generate function 1 (out of 1).
+  builder.addFunction(undefined, 0 /* sig */)
+    .addBodyWithEnd([
+// signature: i_iii
+// body:
+kExprI32Const, 0x20,
+kExprI64LoadMem, 0x00, 0xce, 0xf2, 0xff, 0x01,
+kExprBlock, kWasmF32,   // @9 f32
+  kExprI32Const, 0x04,
+  kExprI32Const, 0x01,
+  kExprBrTable, 0x01, 0x01, 0x00, // entries=1
+  kExprEnd,   // @19
+kExprUnreachable,
+kExprEnd,   // @21
+            ]);
+  builder.addExport('main', 0);
+  assertThrows(
+      () => {builder.toModule()}, WebAssembly.CompileError,
+      'WebAssembly.Module(): Compiling function #0:\"main\" failed: type ' +
+      'error in merge[0] (expected <bot>, got i32) @+57');
+})();
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1048241.js b/deps/v8/test/mjsunit/regress/wasm/regress-1048241.js
new file mode 100644
index 0000000000..5e0e43c9ea
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1048241.js
@@ -0,0 +1,19 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --wasm-staging
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+const builder = new WasmModuleBuilder();
+builder.addMemory(16, 32, false, true);
+const sig = makeSig([kWasmF64, kWasmI64, kWasmI32, kWasmF64], []);
+builder.addFunction(undefined, sig).addBody([
+  kExprI32Const, 0x00,                               // -
+  kExprI32Const, 0x00,                               // -
+  kExprI32Const, 0x00,                               // -
+  kAtomicPrefix, kExprI32AtomicXor16U, 0x01, 0x00,   // -
+  kAtomicPrefix, kExprI32AtomicStore8U, 0x00, 0x00,  // -
+]);
+builder.instantiate();
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1051912.js b/deps/v8/test/mjsunit/regress/wasm/regress-1051912.js
new file mode 100644
index 0000000000..49ffa8cf8e
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1051912.js
@@ -0,0 +1,17 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load('test/mjsunit/wasm/wasm-module-builder.js')
+
+let binary = new Binary();
+binary.emit_header();
+binary.emit_bytes([kTypeSectionCode, 4, 1, kWasmFunctionTypeForm, 0, 0]);
+binary.emit_bytes([kFunctionSectionCode, 2, 1, 0]);
+binary.emit_bytes([kCodeSectionCode, 6, 1, 4]);
+binary.emit_bytes([kUnknownSectionCode, 2, 1, 0]);
+binary.emit_bytes([kUnknownSectionCode, 2, 1, 0]);
+binary.emit_bytes([kUnknownSectionCode, 2, 1, 0]);
+binary.emit_bytes([ kExprEnd]);
+let buffer = binary.trunc_buffer();
+WebAssembly.compile(buffer);
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1054466.js b/deps/v8/test/mjsunit/regress/wasm/regress-1054466.js
new file mode 100644
index 0000000000..85ee43732b
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1054466.js
@@ -0,0 +1,52 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --experimental-wasm-simd
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+const builder = new WasmModuleBuilder();
+builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
+// Generate function 1 (out of 1).
+builder.addFunction(undefined, 0 /* sig */)
+  .addLocals({i32_count: 2}).addLocals({f32_count: 2})
+  .addBodyWithEnd([
+// signature: i_iii
+// body:
+kExprI32Const, 0x00,  // i32.const
+kExprI32Const, 0x00,  // i32.const
+kExprI32Const, 0xf9, 0x00,  // i32.const
+kExprI32Ior,  // i32.or
+kExprI32Eqz,  // i32.eqz
+kExprI32Add,  // i32.Add
+kSimdPrefix, kExprI32x4Splat,  // i32x4.splat
+kExprF32Const, 0x46, 0x5d, 0x00, 0x00,  // f32.const
+kExprI32Const, 0x83, 0x01,  // i32.const
+kExprI32Const, 0x83, 0x01,  // i32.const
+kExprI32Const, 0x83, 0x01,  // i32.const
+kExprI32Add,  // i32.Add
+kExprI32Add,  // i32.Add
+kExprIf, kWasmI32,  // if @33 i32
+  kExprI32Const, 0x00,  // i32.const
+kExprElse,  // else @37
+  kExprI32Const, 0x00,  // i32.const
+  kExprEnd,  // end @40
+kExprIf, kWasmI32,  // if @41 i32
+  kExprI32Const, 0x00,  // i32.const
+kExprElse,  // else @45
+  kExprI32Const, 0x00,  // i32.const
+  kExprEnd,  // end @48
+kExprF32ReinterpretI32,  // f32.reinterpret_i32
+kExprF32Max,  // f32.max
+kSimdPrefix, kExprF32x4Splat,  // f32x4.splat
+kExprI32Const, 0x83, 0x01,  // i32.const
+kSimdPrefix, kExprI32x4Splat,  // i32x4.splat
+kSimdPrefix, kExprI32x4Add,  // i32x4.add
+kSimdPrefix, kExprI32x4Add,  // i32x4.add
+kSimdPrefix, kExprS1x8AnyTrue,  // s1x8.any_true
+kExprEnd,  // end @64
+]);
+builder.addExport('main', 0);
+const instance = builder.instantiate();
+print(instance.exports.main(1, 2, 3));
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-1055692.js b/deps/v8/test/mjsunit/regress/wasm/regress-1055692.js
new file mode 100644
index 0000000000..a16180ab5c
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-1055692.js
@@ -0,0 +1,35 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --wasm-staging --wasm-interpret-all --experimental-wasm-simd
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+const builder = new WasmModuleBuilder();
+builder.addMemory(16, 32, false);
+builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
+// Generate function 1 (out of 1).
+builder.addFunction(undefined, 0 /* sig */)
+  .addBodyWithEnd([
+// signature: i_iii
+// body:
+kExprI32Const, 0x75,  // i32.const
+kExprI32Const, 0x74,  // i32.const
+kExprI32Const, 0x18,  // i32.const
+kSimdPrefix, kExprS8x16LoadSplat,  // s8x16.load_splat
+kExprUnreachable,  // unreachable
+kExprUnreachable,  // unreachable
+kExprI32Const, 0x6f,  // i32.const
+kExprI32Const, 0x7f,  // i32.const
+kExprI32Const, 0x6f,  // i32.const
+kExprDrop,
+kExprDrop,
+kExprDrop,
+kExprDrop,
+kExprDrop,
+kExprEnd,  // end @18
+]);
+builder.addExport('main', 0);
+const instance = builder.instantiate();
+print(instance.exports.main(1, 2, 3));
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-724846.js b/deps/v8/test/mjsunit/regress/wasm/regress-724846.js
index 93220a1c9c..62235bf517 100644
--- a/deps/v8/test/mjsunit/regress/wasm/regress-724846.js
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-724846.js
@@ -10,4 +10,4 @@ let builder = new WasmModuleBuilder();
 const num_pages = 49152;
 builder.addMemory(num_pages, num_pages);
 // num_pages * 64k (page size) > kMaxInt.
-assertThrows(() => builder.instantiate(), RangeError);
+assertThrows(() => builder.instantiate(), WebAssembly.CompileError);
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-789952.js b/deps/v8/test/mjsunit/regress/wasm/regress-789952.js
deleted file mode 100644
index f73d8dc471..0000000000
--- a/deps/v8/test/mjsunit/regress/wasm/regress-789952.js
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-let module_size = 19;
-let string_len = 0x00fffff0 - module_size;
-
-print("Allocating backing store: " + (string_len + module_size));
-let backing = new ArrayBuffer(string_len + module_size);
-
-print("Allocating typed array buffer");
-let buffer = new Uint8Array(backing);
-
-print("Filling...");
-buffer.fill(0x41);
-
-print("Setting up array buffer");
-// Magic
-buffer.set([0x00, 0x61, 0x73, 0x6D], 0);
-// Version
-buffer.set([0x01, 0x00, 0x00, 0x00], 4);
-// kUnknownSection (0)
-buffer.set([0], 8);
-// Section length
-buffer.set([0x80, 0x80, 0x80, 0x80, 0x00],  9);
-// Name length
-let x = string_len + 1;
-let b1 = ((x >> 0) & 0x7F) | 0x80;
-let b2 = ((x >> 7) & 0x7F) | 0x80;
-let b3 = ((x >> 14) & 0x7F) | 0x80;
-let b4 = ((x >> 21) & 0x7F);
-//buffer.set([0xDE, 0xFF, 0xFF, 0x7F], 14);
- buffer.set([b1, b2, b3, b4], 14);
-
-print("Parsing module...");
-let m = new WebAssembly.Module(buffer);
-
-print("Triggering!");
-let c = WebAssembly.Module.customSections(m, "A".repeat(string_len + 1));
-assertEquals(0, c.length);
diff --git a/deps/v8/test/mjsunit/regress/wasm/regress-crbug-1057094.js b/deps/v8/test/mjsunit/regress/wasm/regress-crbug-1057094.js
new file mode 100644
index 0000000000..dc1703178c
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/wasm/regress-crbug-1057094.js
@@ -0,0 +1,14 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --wasm-max-mem-pages=65536
+
+try {
+  var __v_50189 = new WebAssembly.Memory({
+    initial: 65536
+  });
+} catch (e) {
+  // 32-bit builds will throw a RangeError, that's okay.
+  assertTrue(e instanceof RangeError);
+}
diff --git a/deps/v8/test/mjsunit/sealed-array-reduce.js b/deps/v8/test/mjsunit/sealed-array-reduce.js
index a572aa2cc4..2b59c44028 100644
--- a/deps/v8/test/mjsunit/sealed-array-reduce.js
+++ b/deps/v8/test/mjsunit/sealed-array-reduce.js
@@ -3,10 +3,11 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --opt --no-always-opt
+// Flags: --no-lazy-feedback-allocation
 
-/**
- * @fileoverview Test reduce and reduceRight
- */
+// TODO(v8:10195): Fix these tests s.t. we assert deoptimization occurs when
+// expected (e.g. in a %DeoptimizeNow call), then remove
+// --no-lazy-feedback-allocation.
 
 function clone(v) {
   // Shallow-copies arrays, returns everything else verbatim.
diff --git a/deps/v8/test/mjsunit/tools/foozzie.js b/deps/v8/test/mjsunit/tools/foozzie.js
new file mode 100644
index 0000000000..30faf46116
--- /dev/null
+++ b/deps/v8/test/mjsunit/tools/foozzie.js
@@ -0,0 +1,79 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+// Files: tools/clusterfuzz/v8_mock.js
+
+// Test foozzie mocks for differential fuzzing.
+
+// Deterministic Math.random.
+assertEquals(0.1, Math.random());
+assertEquals(0.2, Math.random());
+assertEquals(0.3, Math.random());
+
+// Deterministic date.
+assertEquals(1477662728698, Date.now());
+assertEquals(1477662728701, Date.now());
+assertEquals(1477662728705, new Date().getTime());
+assertEquals(710, new Date.prototype.constructor().getUTCMilliseconds());
+
+// Deterministic arguments in constructor keep working.
+assertEquals(819134640000,
+             new Date('December 17, 1995 03:24:00 GMT+1000').getTime());
+
+// Dummy performance methods.
+assertEquals(1.2, performance.now());
+assertEquals([], performance.measureMemory());
+
+// Worker messages follow a predefined deterministic pattern.
+const worker = new Worker(``, {type: 'string'});
+assertEquals(0, worker.getMessage());
+assertEquals(-1, worker.getMessage());
+
+// NaN patterns in typed arrays are mocked out. Test that we get no
+// difference between unoptimized and optimized code.
+function testSameOptimized(pattern, create_fun) {
+  const expected = new Uint32Array(pattern);
+  %PrepareFunctionForOptimization(create_fun);
+  assertEquals(expected, create_fun());
+  %OptimizeFunctionOnNextCall(create_fun);
+  assertEquals(expected, create_fun());
+}
+
+function testArrayType(arrayType, pattern) {
+  // Test passing NaNs to constructor with array.
+  let create = function() {
+    return new Uint32Array(new arrayType([-NaN]).buffer);
+  };
+  testSameOptimized(pattern, create);
+  // Test passing NaNs to constructor with iterator.
+  create = function() {
+    const iter = function*(){ yield* [-NaN]; }();
+    return new Uint32Array(new arrayType(iter).buffer);
+  };
+  testSameOptimized(pattern, create);
+  // Test setting NaN property.
+  create = function() {
+    const arr = new arrayType(1);
+    arr[0] = -NaN;
+    return new Uint32Array(arr.buffer);
+  };
+  // Test passing NaN using set.
+  testSameOptimized(pattern, create);
+  create = function() {
+    const arr = new arrayType(1);
+    arr.set([-NaN], 0);
+    return new Uint32Array(arr.buffer);
+  };
+  testSameOptimized(pattern, create);
+}
+
+var isBigEndian = new Uint8Array(new Uint16Array([0xABCD]).buffer)[0] === 0xAB;
+testArrayType(Float32Array, [1065353216]);
+if (isBigEndian){
+  testArrayType(Float64Array, [1072693248, 0]);
+}
+else {
+  testArrayType(Float64Array, [0, 1072693248]);
+}
diff --git a/deps/v8/test/mjsunit/tools/foozzie_archs.js b/deps/v8/test/mjsunit/tools/foozzie_archs.js
new file mode 100644
index 0000000000..9023428324
--- /dev/null
+++ b/deps/v8/test/mjsunit/tools/foozzie_archs.js
@@ -0,0 +1,84 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+// Files: tools/clusterfuzz/v8_mock.js
+// Files: tools/clusterfuzz/v8_mock_archs.js
+
+// Test foozzie architecture-specific mocks for differential fuzzing.
+
+// Max typed array length is mocked and restricted to 1MiB buffer.
+const maxBytes = 1048576;
+
+// The maximum also holds for array buffer and shared array buffer.
+assertEquals(maxBytes, new ArrayBuffer(maxBytes + 1).byteLength);
+assertEquals(maxBytes, new SharedArrayBuffer(maxBytes + 1).byteLength);
+
+function testArrayType(type) {
+  const name = type.name;
+  const bytesPerElem = type.BYTES_PER_ELEMENT;
+  const maxElem = maxBytes / bytesPerElem;
+
+  function testLength(expectedLength, arr) {
+    const expectedBytes = expectedLength * bytesPerElem;
+    assertEquals(expectedBytes, arr.byteLength, name);
+    assertEquals(expectedLength, arr.length, name);
+  }
+
+  // Test length argument in constructor.
+  testLength(maxElem - 1, new type(maxElem - 1));
+  testLength(maxElem, new type(maxElem));
+  testLength(maxElem, new type(maxElem + 1));
+
+  // Test buffer argument in constructor.
+  // Unaligned offsets don't throw.
+  const buffer = new ArrayBuffer(maxBytes);
+  new type(buffer, 1);
+  new type(buffer, 3);
+
+  // Offsets work or are capped.
+  function bytes(elements) {
+    return elements * bytesPerElem;
+  }
+  testLength(maxElem, new type(buffer, 0));
+  testLength(maxElem - 1, new type(buffer, bytes(1)));
+  testLength(1, new type(buffer, bytes(maxElem - 1)));
+  testLength(0, new type(buffer, bytes(maxElem)));
+  testLength(0, new type(buffer, bytes(maxElem + 1)));
+
+  // Offset and length work or are capped.
+  testLength(1, new type(buffer, 0, 1));
+  testLength(1, new type(buffer, bytesPerElem, 1));
+  testLength(maxElem - 2, new type(buffer, bytes(1), maxElem - 2));
+  testLength(maxElem - 1, new type(buffer, bytes(1), maxElem - 1));
+  testLength(maxElem - 1, new type(buffer, bytes(1), maxElem));
+  testLength(0, new type(buffer, bytes(maxElem - 1), 0));
+  testLength(1, new type(buffer, bytes(maxElem - 1), 1));
+  testLength(1, new type(buffer, bytes(maxElem - 1), 2));
+
+  // Insertion with "set" works or is capped.
+  let set0 = 0;
+  let set1 = 1;
+  if (name.startsWith("Big")) {
+    set0 = 0n;
+    set1 = 1n;
+  }
+  arr = new type(4);
+  arr.set([set1], 1);
+  assertEquals(new type([set0, set1, set0, set0]), arr, name);
+  arr.set([set1, set1], 3);  // Capped to 2.
+  assertEquals(new type([set0, set1, set1, set1]), arr, name);
+}
+
+testArrayType(Int8Array);
+testArrayType(Uint8Array);
+testArrayType(Uint8ClampedArray);
+testArrayType(Int16Array);
+testArrayType(Uint16Array);
+testArrayType(Int32Array);
+testArrayType(Uint32Array);
+testArrayType(BigInt64Array);
+testArrayType(BigUint64Array);
+testArrayType(Float32Array);
+testArrayType(Float64Array);
diff --git a/deps/v8/test/mjsunit/tools/foozzie_webassembly.js b/deps/v8/test/mjsunit/tools/foozzie_webassembly.js
new file mode 100644
index 0000000000..d5130a393b
--- /dev/null
+++ b/deps/v8/test/mjsunit/tools/foozzie_webassembly.js
@@ -0,0 +1,18 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+// Files: tools/clusterfuzz/v8_mock.js
+// Files: tools/clusterfuzz/v8_mock_webassembly.js
+
+// Test foozzie webassembly-specfific mocks for differential fuzzing.
+
+// No reference errors when accessing WebAssembly.
+WebAssembly[0];
+WebAssembly[" "];
+WebAssembly.foo;
+WebAssembly.foo();
+WebAssembly.foo().bar;
+WebAssembly.foo().bar();
+WebAssembly.foo().bar[0];
diff --git a/deps/v8/test/mjsunit/wasm/anyfunc.js b/deps/v8/test/mjsunit/wasm/anyfunc.js
index 4a53a04468..6f6384cd61 100644
--- a/deps/v8/test/mjsunit/wasm/anyfunc.js
+++ b/deps/v8/test/mjsunit/wasm/anyfunc.js
@@ -222,6 +222,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
   const function_index = builder.addFunction('hidden', kSig_i_v)
                              .addBody([kExprI32Const, expected])
                              .index;
+  builder.addDeclarativeElementSegment([function_index]);
   builder.addFunction('main', kSig_a_v)
       .addBody([kExprRefFunc, function_index])
       .exportFunc();
@@ -237,6 +238,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
   const foo = builder.addFunction('foo', kSig_i_v)
                   .addBody([kExprI32Const, expected])
                   .exportFunc();
+  builder.addDeclarativeElementSegment([foo.index]);
   builder.addFunction('main', kSig_a_v)
       .addBody([kExprRefFunc, foo.index])
       .exportFunc();
diff --git a/deps/v8/test/mjsunit/wasm/anyref-globals.js b/deps/v8/test/mjsunit/wasm/anyref-globals.js
index d243e37486..ae99044a9c 100644
--- a/deps/v8/test/mjsunit/wasm/anyref-globals.js
+++ b/deps/v8/test/mjsunit/wasm/anyref-globals.js
@@ -568,7 +568,7 @@ function dummy_func() {
   const f_func = builder.addFunction('get_anyfunc_global', kSig_a_v)
                      .addBody([kExprGlobalGet, g_func.index])
                      .exportAs('get_anyfunc_global');
-
+  builder.addDeclarativeElementSegment([f_ref.index, f_func.index]);
   g_ref.function_index = f_ref.index;
   g_func.function_index = f_func.index;
 
@@ -580,6 +580,18 @@ function dummy_func() {
       instance.exports.get_anyfunc_global());
 })();
 
+(function TestRefFuncGlobalInitUndeclared() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  const global_func = builder.addGlobal(kWasmAnyFunc, true);
+  const func = builder.addFunction('get_anyfunc_global', kSig_v_v).addBody([]);
+  global_func.function_index = func.index;
+
+  assertThrows(
+      () => builder.toModule(), WebAssembly.CompileError,
+      /undeclared reference to function/);
+})();
+
 (function TestRefFuncGlobalInitWithImport() {
   print(arguments.callee.name);
   let builder = new WasmModuleBuilder();
@@ -588,6 +600,7 @@ function dummy_func() {
   const import_js = builder.addImport('m', 'js', sig_index);
   const g_wasm = builder.addGlobal(kWasmAnyFunc, true);
   const g_js = builder.addGlobal(kWasmAnyFunc, true);
+  builder.addDeclarativeElementSegment([import_wasm, import_js]);
   g_wasm.function_index = import_wasm;
   g_js.function_index = import_js;
   builder.addFunction('get_global_wasm', kSig_a_v)
diff --git a/deps/v8/test/mjsunit/wasm/anyref-table.js b/deps/v8/test/mjsunit/wasm/anyref-table.js
index de35dc8fb8..a7a82099d6 100644
--- a/deps/v8/test/mjsunit/wasm/anyref-table.js
+++ b/deps/v8/test/mjsunit/wasm/anyref-table.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --experimental-wasm-anyref
+// Flags: --experimental-wasm-anyref --experimental-wasm-bulk-memory
 
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
@@ -45,3 +45,35 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   assertThrows(() => builder.instantiate({ imp: { table: table_func } }),
     WebAssembly.LinkError, /imported table does not match the expected type/);
 })();
+
+(function TestAnyRefDropDeclarativeElementSegment() {
+  print(arguments.callee.name);
+
+  const builder = new WasmModuleBuilder();
+  builder.addDeclarativeElementSegment([null]);
+  builder.addFunction('drop', kSig_v_v)
+      .addBody([kNumericPrefix, kExprElemDrop, 0])
+      .exportFunc();
+  const instance = builder.instantiate();
+
+  // Counts as double-drop because declarative segments are dropped on
+  // initialization and is therefore not expected to throw.
+  instance.exports.drop();
+})();
+
+(function TestAnyRefTableInitFromDeclarativeElementSegment() {
+  print(arguments.callee.name);
+
+  const builder = new WasmModuleBuilder();
+  const table = builder.addTable(kWasmAnyFunc, 10);
+  builder.addDeclarativeElementSegment([null]);
+  builder.addFunction('init', kSig_v_v)
+      .addBody([
+        kExprI32Const, 0, kExprI32Const, 0, kExprI32Const, 1, kNumericPrefix,
+        kExprTableInit, table.index, 0
+      ])
+      .exportFunc();
+  const instance = builder.instantiate();
+
+  assertTraps(kTrapTableOutOfBounds, () => instance.exports.init());
+})();
diff --git a/deps/v8/test/mjsunit/wasm/asm-wasm-f32.js b/deps/v8/test/mjsunit/wasm/asm-wasm-f32.js
index 1a89c3ef1a..6f4fa06dff 100644
--- a/deps/v8/test/mjsunit/wasm/asm-wasm-f32.js
+++ b/deps/v8/test/mjsunit/wasm/asm-wasm-f32.js
@@ -166,36 +166,24 @@ function f32_neg(a) {
 
 
 var inputs = [
-  0, 1, 2, 3, 4,
+  0, 1,
   NaN,
   Infinity,
   -Infinity,
-  10, 20, 30, 31, 32, 33, 100, 2000,
-  30000, 400000, 5000000,
-  100000000, 2000000000,
   2147483646,
   2147483647,
   2147483648,
   2147483649,
-  0x273a798e, 0x187937a3, 0xece3af83, 0x5495a16b, 0x0b668ecc, 0x11223344,
-  0x0000af73, 0x0000116b, 0x00658ecc, 0x002b3b4c,
-  0x88776655, 0x70000000, 0x07200000, 0x7fffffff, 0x56123761, 0x7fffff00,
-  0xeeeeeeee, 0xfffffffd, 0xf0000000, 0x007fffff, 0x003fffff, 0x001fffff,
-  -0,
-  -1, -2, -3, -4,
-  -10, -20, -30, -31, -32, -33, -100, -2000,
-  -30000, -400000, -5000000,
-  -100000000, -2000000000,
+  4026531840, // 0xf0000000
+  4294967293, // 0xfffffffd
+  4294967295, // 0xffffffff
+  -0, -1,
   -2147483646,
   -2147483647,
   -2147483648,
   -2147483649,
   0.1,
   1.1e-2,
-  1.2e-4,
-  1.3e-8,
-  1.4e-11,
-  1.5e-12,
   1.6e-13
 ];
 
diff --git a/deps/v8/test/mjsunit/wasm/asm-wasm-f64.js b/deps/v8/test/mjsunit/wasm/asm-wasm-f64.js
index a07de98558..55b4cc4dda 100644
--- a/deps/v8/test/mjsunit/wasm/asm-wasm-f64.js
+++ b/deps/v8/test/mjsunit/wasm/asm-wasm-f64.js
@@ -228,36 +228,24 @@ function f64_neg(a) {
 
 
 var inputs = [
-  0, 1, 2, 3, 4,
+  0, 1,
   NaN,
   Infinity,
   -Infinity,
-  10, 20, 30, 31, 32, 33, 100, 2000,
-  30000, 400000, 5000000,
-  100000000, 2000000000,
   2147483646,
   2147483647,
   2147483648,
   2147483649,
-  0x273a798e, 0x187937a3, 0xece3af83, 0x5495a16b, 0x0b668ecc, 0x11223344,
-  0x0000af73, 0x0000116b, 0x00658ecc, 0x002b3b4c,
-  0x88776655, 0x70000000, 0x07200000, 0x7fffffff, 0x56123761, 0x7fffff00,
-  0xeeeeeeee, 0xfffffffd, 0xf0000000, 0x007fffff, 0x003fffff, 0x001fffff,
-  -0,
-  -1, -2, -3, -4,
-  -10, -20, -30, -31, -32, -33, -100, -2000,
-  -30000, -400000, -5000000,
-  -100000000, -2000000000,
+  4026531840, // 0xf0000000
+  4294967293, // 0xfffffffd
+  4294967295, // 0xffffffff
+  -0, -1,
   -2147483646,
   -2147483647,
   -2147483648,
   -2147483649,
   0.1,
   1.1e-2,
-  1.2e-4,
-  1.3e-8,
-  1.4e-11,
-  1.5e-12,
   1.6e-13
 ];
 
diff --git a/deps/v8/test/mjsunit/wasm/bulk-memory.js b/deps/v8/test/mjsunit/wasm/bulk-memory.js
index 065cbfd22f..2e41fa9ee0 100644
--- a/deps/v8/test/mjsunit/wasm/bulk-memory.js
+++ b/deps/v8/test/mjsunit/wasm/bulk-memory.js
@@ -214,3 +214,20 @@ function getMemoryFill(mem) {
 
   assertEquals(0, view[0]);
 })();
+
+(function TestPassiveDataSegmentNoMemory() {
+  const builder = new WasmModuleBuilder();
+  builder.addPassiveDataSegment([0, 1, 2]);
+
+  // Should not throw.
+  builder.instantiate();
+})();
+
+(function TestPassiveElementSegmentNoMemory() {
+  const builder = new WasmModuleBuilder();
+  builder.addFunction('f', kSig_v_v).addBody([]);
+  builder.addPassiveElementSegment([0, 0, 0]);
+
+  // Should not throw.
+  builder.instantiate();
+})();
diff --git a/deps/v8/test/mjsunit/wasm/exceptions-anyref.js b/deps/v8/test/mjsunit/wasm/exceptions-anyref.js
index b18b11aac0..93bb68d6f6 100644
--- a/deps/v8/test/mjsunit/wasm/exceptions-anyref.js
+++ b/deps/v8/test/mjsunit/wasm/exceptions-anyref.js
@@ -146,6 +146,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
 
 // Test storing and loading to/from an exception type table.
 (function TestTableExnRef() {
+  print(arguments.callee.name);
   let kSig_e_i = makeSig([kWasmI32], [kWasmExnRef]);
   let kSig_v_ie = makeSig([kWasmI32, kWasmExnRef], []);
   let builder = new WasmModuleBuilder();
@@ -182,3 +183,97 @@ load("test/mjsunit/wasm/exceptions-utils.js");
   assertSame(e0, instance.exports.table.get(0));
   assertSame(e1, instance.exports.table.get(1));
 })();
+
+// 'br_on_exn' on a null-ref value should trap.
+(function TestBrOnExnNullRefSimple() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let except = builder.addException(kSig_v_r);
+  builder.addFunction('br_on_exn_nullref', kSig_v_v)
+      .addBody([
+        kExprRefNull,
+        kExprBrOnExn, 0, except,
+        kExprDrop
+      ]).exportFunc();
+  let instance = builder.instantiate();
+
+  assertTraps(kTrapBrOnExnNullRef, () => instance.exports.br_on_exn_nullref());
+})();
+
+(function TestBrOnExnNullRefFromJS() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let except = builder.addException(kSig_v_i);
+  let imp = builder.addImport('imp', 'ort', kSig_i_i);
+  let kConstant0 = 11;
+  let kNoMatch = 13;
+  builder.addFunction('call_import', kSig_i_i)
+      .addBody([
+        kExprTry, kWasmI32,
+          kExprLocalGet, 0,
+          kExprCallFunction, imp,
+        kExprCatch,
+          kExprBrOnExn, 0, except,
+          kExprDrop,
+          kExprI32Const, kNoMatch,
+        kExprEnd
+      ]).exportFunc();
+  let instance;
+  function js_import(i) {
+    if (i == 0) return kConstant0;     // Will return kConstant0.
+    if (i == 1) throw new Error('1');  // Will not match.
+    if (i == 2) throw null;            // Will trap.
+    throw undefined;                   // Will not match.
+  }
+  instance = builder.instantiate({imp: {ort: js_import}});
+
+  assertEquals(kConstant0, instance.exports.call_import(0));
+  assertEquals(kNoMatch, instance.exports.call_import(1));
+  assertTraps(kTrapBrOnExnNullRef, () => instance.exports.call_import(2));
+  assertEquals(kNoMatch, instance.exports.call_import(3));
+})();
+
+// 'rethrow' on a null-ref value should trap.
+(function TestRethrowNullRefSimple() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let except = builder.addException(kSig_v_r);
+  builder.addFunction('rethrow_nullref', kSig_v_v)
+      .addBody([
+        kExprRefNull,
+        kExprRethrow
+      ]).exportFunc();
+  let instance = builder.instantiate();
+
+  assertTraps(kTrapRethrowNullRef, () => instance.exports.rethrow_nullref());
+})();
+
+(function TestRethrowNullRefFromJS() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let except = builder.addException(kSig_v_i);
+  let imp = builder.addImport('imp', 'ort', kSig_i_i);
+  let kSuccess = 11;
+  builder.addFunction('call_import', kSig_i_i)
+      .addBody([
+        kExprTry, kWasmI32,
+          kExprLocalGet, 0,
+          kExprCallFunction, imp,
+        kExprCatch,
+          kExprRethrow,
+        kExprEnd
+      ]).exportFunc();
+  let instance;
+  function js_import(i) {
+    if (i == 0) return kSuccess;       // Will return kSuccess.
+    if (i == 1) throw new Error('1');  // Will rethrow.
+    if (i == 2) throw null;            // Will trap.
+    throw undefined;                   // Will rethrow.
+  }
+  instance = builder.instantiate({imp: {ort: js_import}});
+
+  assertEquals(kSuccess, instance.exports.call_import(0));
+  assertThrows(() => instance.exports.call_import(1), Error, '1');
+  assertTraps(kTrapRethrowNullRef, () => instance.exports.call_import(2));
+  assertThrowsEquals(() => instance.exports.call_import(3), undefined);
+})();
diff --git a/deps/v8/test/mjsunit/wasm/exceptions.js b/deps/v8/test/mjsunit/wasm/exceptions.js
index ecaf0d06c9..fc82455ca8 100644
--- a/deps/v8/test/mjsunit/wasm/exceptions.js
+++ b/deps/v8/test/mjsunit/wasm/exceptions.js
@@ -85,6 +85,110 @@ load("test/mjsunit/wasm/exceptions-utils.js");
   assertEquals(42, instance.exports.simple_throw_catch_to_0_1(1));
 })();
 
+(function TestTrapNotCaught() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  builder.addFunction('unreachable_in_try', kSig_v_v)
+      .addBody([
+        kExprTry, kWasmStmt,
+          kExprUnreachable,
+        kExprCatch,
+          kExprDrop,
+        kExprEnd
+      ]).exportFunc();
+  let instance = builder.instantiate();
+
+  assertTraps(kTrapUnreachable, () => instance.exports.unreachable_in_try());
+})();
+
+(function TestTrapInCalleeNotCaught() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let func_div = builder.addFunction('div', kSig_i_ii).addBody([
+    kExprLocalGet, 0,
+    kExprLocalGet, 1,
+    kExprI32DivU
+  ]);
+  builder.addFunction('trap_in_callee', kSig_i_ii)
+      .addBody([
+        kExprTry, kWasmI32,
+          kExprLocalGet, 0,
+          kExprLocalGet, 1,
+          kExprCallFunction, func_div.index,
+        kExprCatch,
+          kExprDrop,
+          kExprI32Const, 11,
+        kExprEnd
+      ]).exportFunc();
+  let instance = builder.instantiate();
+
+  assertEquals(3, instance.exports.trap_in_callee(7, 2));
+  assertTraps(kTrapDivByZero, () => instance.exports.trap_in_callee(1, 0));
+})();
+
+(function TestTrapViaJSNotCaught() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let imp = builder.addImport('imp', 'ort', kSig_i_v);
+  builder.addFunction('div', kSig_i_ii)
+      .addBody([
+        kExprLocalGet, 0,
+        kExprLocalGet, 1,
+        kExprI32DivU
+      ]).exportFunc();
+  builder.addFunction('call_import', kSig_i_v)
+      .addBody([
+        kExprTry, kWasmI32,
+          kExprCallFunction, imp,
+        kExprCatch,
+          kExprDrop,
+          kExprI32Const, 11,
+        kExprEnd
+      ]).exportFunc();
+  let exception = undefined;
+  let instance;
+  function js_import() {
+    try {
+      instance.exports.div(1, 0);
+    } catch (e) {
+      exception = e;
+    }
+    throw exception;
+  }
+  instance = builder.instantiate({imp: {ort: js_import}});
+  let caught = undefined;
+  try {
+    let res = instance.exports.call_import();
+    assertUnreachable('call_import should trap, but returned with ' + res);
+  } catch (e) {
+    caught = e;
+  }
+  assertSame(exception, caught);
+  assertInstanceof(exception, WebAssembly.RuntimeError);
+  assertEquals(exception.message, kTrapMsgs[kTrapDivByZero]);
+})();
+
+(function TestManuallyThrownRuntimeErrorCaught() {
+  print(arguments.callee.name);
+  let builder = new WasmModuleBuilder();
+  let imp = builder.addImport('imp', 'ort', kSig_i_v);
+  builder.addFunction('call_import', kSig_i_v)
+      .addBody([
+        kExprTry, kWasmI32,
+          kExprCallFunction, imp,
+        kExprCatch,
+          kExprDrop,
+          kExprI32Const, 11,
+        kExprEnd
+      ]).exportFunc();
+  function throw_exc() {
+    throw exception = new WebAssembly.RuntimeError('My user text');
+  }
+  let instance = builder.instantiate({imp: {ort: throw_exc}});
+
+  assertEquals(11, instance.exports.call_import());
+})();
+
 // Test that we can distinguish which exception was thrown by using a cascaded
 // sequence of nested try blocks with a single handler in each catch block.
 (function TestCatchComplex1() {
diff --git a/deps/v8/test/mjsunit/wasm/grow-huge-memory.js b/deps/v8/test/mjsunit/wasm/grow-huge-memory.js
new file mode 100644
index 0000000000..5fe8f5dccf
--- /dev/null
+++ b/deps/v8/test/mjsunit/wasm/grow-huge-memory.js
@@ -0,0 +1,35 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Save some memory on Linux; other platforms ignore this flag.
+// Flags: --multi-mapped-mock-allocator
+
+// Test that we can grow memories to sizes beyond 2GB.
+
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+function GetMemoryPages(memory) {
+  return memory.buffer.byteLength >>> 16;
+}
+
+(function TestGrowFromJS() {
+  let mem = new WebAssembly.Memory({initial: 200});
+  mem.grow(40000);
+  assertEquals(40200, GetMemoryPages(mem));
+})();
+
+(function TestGrowFromWasm() {
+  let builder = new WasmModuleBuilder();
+  builder.addMemory(200, 50000, true);
+  builder.addFunction("grow", kSig_i_v)
+    .addBody([
+      ...wasmI32Const(40000),        // Number of pages to grow by.
+      kExprMemoryGrow, kMemoryZero,  // Grow memory.
+      kExprDrop,                     // Drop result of grow (old pages).
+      kExprMemorySize, kMemoryZero   // Get the memory size.
+      ]).exportFunc();
+  let instance = builder.instantiate();
+  assertEquals(40200, instance.exports.grow());
+  assertEquals(40200, GetMemoryPages(instance.exports.memory));
+})();
diff --git a/deps/v8/test/mjsunit/wasm/grow-memory.js b/deps/v8/test/mjsunit/wasm/grow-memory.js
index 6d0e7e5c5f..2984b1a6b6 100644
--- a/deps/v8/test/mjsunit/wasm/grow-memory.js
+++ b/deps/v8/test/mjsunit/wasm/grow-memory.js
@@ -37,151 +37,86 @@ function genMemoryGrowBuilder() {
 }
 
 // V8 internal memory size limit.
-var kV8MaxPages = 32767;
+var kV8MaxPages = 65536;
 
 
-// TODO(gdeepti): Generate tests programatically for all the sizes instead of
-// current implementation.
-function testMemoryGrowReadWrite32() {
+function testMemoryGrowReadWriteBase(size, load_fn, store_fn) {
+  // size is the number of bytes for load and stores.
   var builder = genMemoryGrowBuilder();
   builder.addMemory(1, undefined, false);
   var module = builder.instantiate();
   var offset;
-  function peek() { return module.exports.load(offset); }
-  function poke(value) { return module.exports.store(offset, value); }
+  var load = module.exports[load_fn];
+  var store = module.exports[store_fn];
+  function peek() { return load(offset); }
+  function poke(value) { return store(offset, value); }
   function growMem(pages) { return module.exports.grow_memory(pages); }
 
-  for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
+  // Instead of checking every n-th offset, check the first 5.
+  for(offset = 0; offset <= (4*size); offset+=size) {
     poke(20);
     assertEquals(20, peek());
   }
-  for (offset = kPageSize - 3; offset < kPageSize + 4; offset++) {
+  for (offset = kPageSize - (size - 1); offset < kPageSize + size; offset++) {
     assertTraps(kTrapMemOutOfBounds, poke);
     assertTraps(kTrapMemOutOfBounds, peek);
   }
 
   assertEquals(1, growMem(3));
 
-  for (offset = kPageSize; offset <= 4*kPageSize -4; offset+=4) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 4*kPageSize - 3; offset < 4*kPageSize + 4; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
+  for (let n = 1; n <= 3; n++) {
+    for (offset = n * kPageSize - 5 * size; offset <= n * kPageSize + 4 * size;
+         offset += size) {
+      // Check the 5 offsets to the before and after the n-th page.
+      //    page n-1              page n          page n+1
+      //    +---- ... ------------+---------- ... +------ ...
+      //    | | | ... | | | | | | | | | | | | ... | | | | ...
+      //      <+>       ^                 ^
+      //       |        first offset      last offset
+      //       +-> size bytes
+      poke(20);
+      assertEquals(20, peek());
+    }
   }
 
-  assertEquals(4, growMem(15));
-
-  for (offset = 4*kPageSize - 3; offset <= 4*kPageSize + 4; offset+=4) {
+  // Check the last 5 valid offsets of the last page.
+  for (offset = 4*kPageSize-size-(4*size); offset <= 4*kPageSize -size; offset+=size) {
     poke(20);
     assertEquals(20, peek());
   }
-  for (offset = 19*kPageSize - 10; offset <= 19*kPageSize - 4; offset+=4) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 19*kPageSize - 3; offset < 19*kPageSize + 5; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-}
-
-testMemoryGrowReadWrite32();
 
-function testMemoryGrowReadWrite16() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(1, undefined, false);
-  var module = builder.instantiate();
-  var offset;
-  function peek() { return module.exports.load16(offset); }
-  function poke(value) { return module.exports.store16(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
-
-  for(offset = 0; offset <= (kPageSize - 2); offset+=2) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = kPageSize - 1; offset < kPageSize + 4; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-
-  assertEquals(1, growMem(3));
-
-  for (offset = kPageSize; offset <= 4*kPageSize -2; offset+=2) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 4*kPageSize - 1; offset < 4*kPageSize + 4; offset++) {
+  for (offset = 4*kPageSize - (size-1); offset < 4*kPageSize + size; offset++) {
     assertTraps(kTrapMemOutOfBounds, poke);
     assertTraps(kTrapMemOutOfBounds, peek);
   }
 
   assertEquals(4, growMem(15));
 
-  for (offset = 4*kPageSize - 2; offset <= 4*kPageSize + 4; offset+=2) {
+  for (offset = 4*kPageSize - (size-1); offset <= 4*kPageSize + size; offset+=size) {
     poke(20);
     assertEquals(20, peek());
   }
-  for (offset = 19*kPageSize - 10; offset <= 19*kPageSize - 2; offset+=2) {
+  for (offset = 19*kPageSize - 10; offset <= 19*kPageSize - size; offset+=size) {
     poke(20);
     assertEquals(20, peek());
   }
-  for (offset = 19*kPageSize - 1; offset < 19*kPageSize + 5; offset++) {
+  for (offset = 19*kPageSize - (size-1); offset < 19*kPageSize + 5; offset++) {
     assertTraps(kTrapMemOutOfBounds, poke);
     assertTraps(kTrapMemOutOfBounds, peek);
   }
 }
 
-testMemoryGrowReadWrite16();
-
-function testMemoryGrowReadWrite8() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(1, undefined, false);
-  var module = builder.instantiate();
-  var offset;
-  function peek() { return module.exports.load8(offset); }
-  function poke(value) { return module.exports.store8(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
-
-  for(offset = 0; offset <= kPageSize - 1; offset++) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = kPageSize; offset < kPageSize + 4; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
+(function testMemoryGrowReadWrite32() {
+  testMemoryGrowReadWriteBase(4, "load", "store");
+})();
 
-  assertEquals(1, growMem(3));
+(function testMemoryGrowReadWrite16() {
+  testMemoryGrowReadWriteBase(2, "load16", "store16");
+})();
 
-  for (offset = kPageSize; offset <= 4*kPageSize -1; offset++) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 4*kPageSize; offset < 4*kPageSize + 4; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-
-  assertEquals(4, growMem(15));
-
-  for (offset = 4*kPageSize; offset <= 4*kPageSize + 4; offset++) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 19*kPageSize - 10; offset <= 19*kPageSize - 1; offset++) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-  for (offset = 19*kPageSize; offset < 19*kPageSize + 5; offset++) {
-    assertTraps(kTrapMemOutOfBounds, poke);
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-}
-
-testMemoryGrowReadWrite8();
+(function testMemoryGrowReadWrite8() {
+  testMemoryGrowReadWriteBase(1, "load8", "store8");
+})();
 
 function testMemoryGrowZeroInitialSize() {
   var builder = genMemoryGrowBuilder();
@@ -197,7 +132,14 @@ function testMemoryGrowZeroInitialSize() {
 
   assertEquals(0, growMem(1));
 
-  for(offset = 0; offset <= kPageSize - 4; offset++) {
+  // Check first 5 offsets.
+  for(offset = 0; offset <= 5; offset++) {
+    poke(20);
+    assertEquals(20, peek());
+  }
+
+  // Check last 5 offsets.
+  for(offset = kPageSize - 5*4; offset <= kPageSize - 4; offset++) {
     poke(20);
     assertEquals(20, peek());
   }
@@ -217,13 +159,15 @@ function testMemoryGrowZeroInitialSize() {
 
 testMemoryGrowZeroInitialSize();
 
-function testMemoryGrowZeroInitialSize32() {
+function testMemoryGrowZeroInitialSizeBase(size, load_fn, store_fn) {
   var builder = genMemoryGrowBuilder();
   builder.addMemory(0, undefined, false);
   var module = builder.instantiate();
   var offset;
-  function peek() { return module.exports.load(offset); }
-  function poke(value) { return module.exports.store(offset, value); }
+  var load = module.exports[load_fn];
+  var store = module.exports[store_fn];
+  function peek() { return load(offset); }
+  function poke(value) { return store(offset, value); }
   function growMem(pages) { return module.exports.grow_memory(pages); }
 
   assertTraps(kTrapMemOutOfBounds, peek);
@@ -231,69 +175,34 @@ function testMemoryGrowZeroInitialSize32() {
 
   assertEquals(0, growMem(1));
 
-  for(offset = 0; offset <= kPageSize - 4; offset++) {
+  // Instead of checking every offset, check the first 5.
+  for(offset = 0; offset <= 4; offset++) {
     poke(20);
     assertEquals(20, peek());
   }
 
-  for(offset = kPageSize - 3; offset <= kPageSize + 5; offset++) {
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-}
-
-testMemoryGrowZeroInitialSize32();
-
-function testMemoryGrowZeroInitialSize16() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(0, undefined, false);
-  var module = builder.instantiate();
-  var offset;
-  function peek() { return module.exports.load16(offset); }
-  function poke(value) { return module.exports.store16(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
-
-  assertTraps(kTrapMemOutOfBounds, peek);
-  assertTraps(kTrapMemOutOfBounds, poke);
-
-  assertEquals(0, growMem(1));
-
-  for(offset = 0; offset <= kPageSize - 2; offset++) {
+  // Check the last 5 valid ones.
+  for(offset = kPageSize - (size * 4); offset <= kPageSize - size; offset++) {
     poke(20);
     assertEquals(20, peek());
   }
 
-  for(offset = kPageSize - 1; offset <= kPageSize + 5; offset++) {
+  for(offset = kPageSize - (size - 1); offset <= kPageSize + 5; offset++) {
     assertTraps(kTrapMemOutOfBounds, peek);
   }
 }
 
-testMemoryGrowZeroInitialSize16();
+(function testMemoryGrowZeroInitialSize32() {
+  testMemoryGrowZeroInitialSizeBase(4, "load", "store");
+})();
 
-function testMemoryGrowZeroInitialSize8() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(0, undefined, false);
-  var module = builder.instantiate();
-  var offset;
-  function peek() { return module.exports.load8(offset); }
-  function poke(value) { return module.exports.store8(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
+(function testMemoryGrowZeroInitialSize16() {
+  testMemoryGrowZeroInitialSizeBase(2, "load16", "store16");
+})();
 
-  assertTraps(kTrapMemOutOfBounds, peek);
-  assertTraps(kTrapMemOutOfBounds, poke);
-
-  assertEquals(0, growMem(1));
-
-  for(offset = 0; offset <= kPageSize - 1; offset++) {
-    poke(20);
-    assertEquals(20, peek());
-  }
-
-  for(offset = kPageSize; offset <= kPageSize + 5; offset++) {
-    assertTraps(kTrapMemOutOfBounds, peek);
-  }
-}
-
-testMemoryGrowZeroInitialSize8();
+(function testMemoryGrowZeroInitialSize8() {
+  testMemoryGrowZeroInitialSizeBase(1, "load8", "store8");
+})();
 
 function testMemoryGrowTrapMaxPagesZeroInitialMemory() {
   var builder = genMemoryGrowBuilder();
@@ -343,78 +252,55 @@ function testMemoryGrowCurrentMemory() {
 
 testMemoryGrowCurrentMemory();
 
-function testMemoryGrowPreservesDataMemOp32() {
+function testMemoryGrowPreservesDataMemOpBase(size, load_fn, store_fn) {
   var builder = genMemoryGrowBuilder();
   builder.addMemory(1, undefined, false);
   var module = builder.instantiate();
-  var offset, val;
-  function peek() { return module.exports.load(offset); }
-  function poke(value) { return module.exports.store(offset, value); }
+  var offset;
+  var load = module.exports[load_fn];
+  var store = module.exports[store_fn];
+  function peek() { return load(offset); }
+  function poke(value) { return store(offset, value); }
   function growMem(pages) { return module.exports.grow_memory(pages); }
+  // Maximum unsigned integer of size bits.
+  const max = Math.pow(2, (size * 8)) - 1;
 
-  for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
-    poke(100000 - offset);
-    assertEquals(100000 - offset, peek());
-  }
-
-  assertEquals(1, growMem(3));
-
-  for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
-    assertEquals(100000 - offset, peek());
+  // Check the first 5 offsets.
+  for(offset = 0; offset <= (4*size); offset+=size) {
+    poke(offset % max);
+    assertEquals(offset % max, peek());
   }
-}
 
-testMemoryGrowPreservesDataMemOp32();
-
-function testMemoryGrowPreservesDataMemOp16() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(1, undefined, false);
-  var module = builder.instantiate();
-  var offset, val;
-  function peek() { return module.exports.load16(offset); }
-  function poke(value) { return module.exports.store16(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
-
-  for(offset = 0; offset <= (kPageSize - 2); offset+=2) {
-    poke(65535 - offset);
-    assertEquals(65535 - offset, peek());
+  // Check the last 5 valid offsets.
+  for(offset = kPageSize - 5*size; offset <= (kPageSize - size); offset+=size) {
+    poke(offset % max);
+    assertEquals(offset % max, peek());
   }
 
   assertEquals(1, growMem(3));
 
-  for(offset = 0; offset <= (kPageSize - 2); offset+=2) {
-    assertEquals(65535 - offset, peek());
+  // Check the first 5 offsets are preserved by growMem.
+  for(offset = 0; offset <= (4*size); offset+=size) {
+    assertEquals(offset % max, peek());
   }
-}
-
-testMemoryGrowPreservesDataMemOp16();
 
-function testMemoryGrowPreservesDataMemOp8() {
-  var builder = genMemoryGrowBuilder();
-  builder.addMemory(1, undefined, false);
-  var module = builder.instantiate();
-  var offset, val = 0;
-  function peek() { return module.exports.load8(offset); }
-  function poke(value) { return module.exports.store8(offset, value); }
-  function growMem(pages) { return module.exports.grow_memory(pages); }
-
-  for(offset = 0; offset <= (kPageSize - 1); offset++, val++) {
-    poke(val);
-    assertEquals(val, peek());
-    if (val == 255) val = 0;
+  // Check the last 5 valid offsets are preserved by growMem.
+  for(offset = kPageSize - 5*size; offset <= (kPageSize - size); offset+=size) {
+    assertEquals(offset % max, peek());
   }
+}
 
-  assertEquals(1, growMem(3));
-
-  val = 0;
+(function testMemoryGrowPreservesDataMemOp32() {
+  testMemoryGrowPreservesDataMemOpBase(4, "load", "store");
+})();
 
-  for(offset = 0; offset <= (kPageSize - 1); offset++, val++) {
-    assertEquals(val, peek());
-    if (val == 255) val = 0;
-  }
-}
+(function testMemoryGrowPreservesDataMemOp16() {
+  testMemoryGrowPreservesDataMemOpBase(2, "load16", "store16");
+})();
 
-testMemoryGrowPreservesDataMemOp8();
+(function testMemoryGrowPreservesDataMemOp8() {
+  testMemoryGrowPreservesDataMemOpBase(1, "load8", "store8");
+})();
 
 function testMemoryGrowOutOfBoundsOffset() {
   var builder = genMemoryGrowBuilder();
@@ -436,7 +322,12 @@ function testMemoryGrowOutOfBoundsOffset() {
 
   assertEquals(3, growMem(1));
 
-  for (offset = 3*kPageSize; offset <= 4*kPageSize - 4; offset++) {
+  for (offset = 3*kPageSize; offset <= 3*kPageSize + 4; offset++) {
+    poke(0xaced);
+    assertEquals(0xaced, peek());
+  }
+
+  for (offset = 4*kPageSize-8; offset <= 4*kPageSize - 4; offset++) {
     poke(0xaced);
     assertEquals(0xaced, peek());
   }
@@ -477,23 +368,18 @@ function testMemoryGrowDeclaredMaxTraps() {
 
 testMemoryGrowDeclaredMaxTraps();
 
-function testMemoryGrowDeclaredSpecMaxTraps() {
-  // The spec maximum is higher than the internal V8 maximum. This test only
-  // checks that grow_memory does not grow past the internally defined maximum
-  // to reflect the current implementation.
+(function testMemoryGrowInternalMaxTraps() {
+  // This test checks that grow_memory does not grow past the internally
+  // defined maximum memory size.
   var builder = genMemoryGrowBuilder();
   builder.addMemory(1, kSpecMaxPages, false);
   var module = builder.instantiate();
-  function poke(value) { return module.exports.store(offset, value); }
   function growMem(pages) { return module.exports.grow_memory(pages); }
   assertEquals(1, growMem(20));
   assertEquals(-1, growMem(kV8MaxPages - 20));
-}
-
-testMemoryGrowDeclaredSpecMaxTraps();
+})();
 
-function testMemoryGrow2Gb() {
-  print("testMemoryGrow2Gb");
+(function testMemoryGrow4Gb() {
   var builder = genMemoryGrowBuilder();
   builder.addMemory(1, undefined, false);
   var module = builder.instantiate();
@@ -502,36 +388,46 @@ function testMemoryGrow2Gb() {
   function poke(value) { return module.exports.store(offset, value); }
   function growMem(pages) { return module.exports.grow_memory(pages); }
 
-  for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
+  // Check first 5 offsets.
+  for (offset = 0; offset <= 4 * 4; offset += 4) {
+    poke(100000 - offset);
+    assertEquals(100000 - offset, peek());
+  }
+
+  // Check last 5 offsets.
+  for (offset = (kPageSize - 5 * 4); offset <= (kPageSize - 4); offset += 4) {
     poke(100000 - offset);
     assertEquals(100000 - offset, peek());
   }
 
   let result = growMem(kV8MaxPages - 1);
-  if (result == 1 ){
-    for(offset = 0; offset <= (kPageSize - 4); offset+=4) {
+  if (result == 1) {
+    // Check first 5 offsets.
+    for (offset = 0; offset <= 4 * 4; offset += 4) {
+      assertEquals(100000 - offset, peek());
+    }
+
+    // Check last 5 offsets.
+    for (offset = (kPageSize - 5 * 4); offset <= (kPageSize - 4); offset += 4) {
       assertEquals(100000 - offset, peek());
     }
 
-    // Bounds check for large mem size
-    for(offset = (kV8MaxPages - 1) * kPageSize;
-        offset <= (kV8MaxPages * kPageSize - 4); offset+=4) {
+    // Bounds check for large mem size.
+    let kMemSize = (kV8MaxPages * kPageSize);
+    let kLastValidOffset = kMemSize - 4;  // Accommodate a 4-byte read/write.
+    // Check first 5 offsets of last page.
+    for (offset = kMemSize - kPageSize; offset <= kMemSize - kPageSize + 4 * 4;
+         offset += 4) {
       poke(0xaced);
       assertEquals(0xaced, peek());
     }
-
-    for (offset = kV8MaxPages * kPageSize - 3;
-        offset <= kV8MaxPages * kPageSize + 4; offset++) {
-      assertTraps(kTrapMemOutOfBounds, poke);
+    for (offset = kLastValidOffset - 5 * 4; offset <= kLastValidOffset;
+         offset += 4) {
+      poke(0xaced);
+      assertEquals(0xaced, peek());
     }
 
-    // Check traps around 3GB/4GB boundaries
-    let offset_3gb = 49152 * kPageSize;
-    let offset_4gb = 2 * kV8MaxPages * kPageSize;
-    for (offset = offset_3gb - 5; offset < offset_3gb + 4; offset++) {
-      assertTraps(kTrapMemOutOfBounds, poke);
-    }
-    for (offset = offset_4gb - 5; offset < offset_4gb; offset++) {
+    for (offset = kLastValidOffset + 1; offset < kMemSize; offset++) {
       assertTraps(kTrapMemOutOfBounds, poke);
     }
   } else {
@@ -539,6 +435,4 @@ function testMemoryGrow2Gb() {
     // bit platforms. When grow_memory fails, expected result is -1.
     assertEquals(-1, result);
   }
-}
-
-testMemoryGrow2Gb();
+})();
diff --git a/deps/v8/test/mjsunit/wasm/import-memory.js b/deps/v8/test/mjsunit/wasm/import-memory.js
index 08100efabd..bac6d8f624 100644
--- a/deps/v8/test/mjsunit/wasm/import-memory.js
+++ b/deps/v8/test/mjsunit/wasm/import-memory.js
@@ -7,7 +7,7 @@
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 // V8 internal memory size limit.
-var kV8MaxPages = 32767;
+var kV8MaxPages = 65536;
 
 (function TestOne() {
   print("TestOne");
diff --git a/deps/v8/test/mjsunit/wasm/interpreter-mixed.js b/deps/v8/test/mjsunit/wasm/interpreter-mixed.js
index 2d15e03c79..2e72a88839 100644
--- a/deps/v8/test/mjsunit/wasm/interpreter-mixed.js
+++ b/deps/v8/test/mjsunit/wasm/interpreter-mixed.js
@@ -186,11 +186,11 @@ function redirectToInterpreter(
       assertUnreachable('should trap because of unreachable instruction');
     } catch (e) {
       checkStack(stripPath(e.stack), [
-        'Error: i=8',                                                // -
-        /^    at imp \(file:\d+:29\)$/,                              // -
-        '    at plus_one (wasm-function[1]:0x3b)',                   // -
-        '    at plus_two (wasm-function[1]:0x3e)',                   // -
-        /^    at testStackTraceThroughCWasmEntry \(file:\d+:25\)$/,  // -
+        'Error: i=8',                                                   // -
+        /^    at imp \(file:\d+:29\)$/,                                 // -
+        '    at plus_one (<anonymous>:wasm-function[1]:0x3b)',          // -
+        '    at plus_two (<anonymous>:wasm-function[1]:0x3e)',          // -
+        /^    at testStackTraceThroughCWasmEntry \(file:\d+:25\)$/,     // -
         /^    at file:\d+:3$/
       ]);
     }
diff --git a/deps/v8/test/mjsunit/wasm/interpreter.js b/deps/v8/test/mjsunit/wasm/interpreter.js
index 43ecc4a33a..99debff846 100644
--- a/deps/v8/test/mjsunit/wasm/interpreter.js
+++ b/deps/v8/test/mjsunit/wasm/interpreter.js
@@ -37,10 +37,10 @@ function checkStack(stack, expected_lines) {
     instance.exports.main();
     assertEquals(interpreted_before + 1, %WasmNumInterpretedCalls(instance));
     checkStack(stripPath(stack), [
-      'Error: test imported stack',                           // -
-      /^    at func \(interpreter.js:\d+:28\)$/,              // -
-      '    at main (wasm-function[1]:0x32)',                  // -
-      /^    at testCallImported \(interpreter.js:\d+:22\)$/,  // -
+      'Error: test imported stack',                          // -
+      /^    at func \(interpreter.js:\d+:28\)$/,             // -
+      '    at main (<anonymous>:wasm-function[1]:0x32)',     // -
+      /^    at testCallImported \(interpreter.js:\d+:22\)$/, // -
       /^    at interpreter.js:\d+:3$/
     ]);
   }
@@ -102,10 +102,10 @@ function checkStack(stack, expected_lines) {
     }
     assertEquals(interpreted_before + 2, %WasmNumInterpretedCalls(instance));
     checkStack(stripPath(stack), [
-      'RuntimeError: unreachable',                    // -
-      '    at foo (wasm-function[0]:0x27)',           // -
-      '    at main (wasm-function[1]:0x2c)',          // -
-      /^    at testTrap \(interpreter.js:\d+:24\)$/,  // -
+      'RuntimeError: unreachable',                       // -
+      '    at foo (<anonymous>:wasm-function[0]:0x27)',  // -
+      '    at main (<anonymous>:wasm-function[1]:0x2c)', // -
+      /^    at testTrap \(interpreter.js:\d+:24\)$/,     // -
       /^    at interpreter.js:\d+:3$/
     ]);
   }
@@ -134,10 +134,10 @@ function checkStack(stack, expected_lines) {
     }
     assertEquals(interpreted_before + 1, %WasmNumInterpretedCalls(instance));
     checkStack(stripPath(stack), [
-      'Error: thrown from imported function',                    // -
-      /^    at func \(interpreter.js:\d+:11\)$/,                 // -
-      '    at main (wasm-function[1]:0x32)',                     // -
-      /^    at testThrowFromImport \(interpreter.js:\d+:24\)$/,  // -
+      'Error: thrown from imported function',                   // -
+      /^    at func \(interpreter.js:\d+:11\)$/,                // -
+      '    at main (<anonymous>:wasm-function[1]:0x32)',        // -
+      /^    at testThrowFromImport \(interpreter.js:\d+:24\)$/, // -
       /^    at interpreter.js:\d+:3$/
     ]);
   }
@@ -218,10 +218,10 @@ function checkStack(stack, expected_lines) {
     for (var e = 0; e < stacks.length; ++e) {
       expected = ['Error: reentrant interpreter test #' + e];
       expected.push(/^    at func \(interpreter.js:\d+:17\)$/);
-      expected.push('    at main (wasm-function[1]:0x36)');
+      expected.push('    at main (<anonymous>:wasm-function[1]:0x36)');
       for (var k = e; k > 0; --k) {
         expected.push(/^    at func \(interpreter.js:\d+:33\)$/);
-        expected.push('    at main (wasm-function[1]:0x36)');
+        expected.push('    at main (<anonymous>:wasm-function[1]:0x36)');
       }
       expected.push(
           /^    at testReentrantInterpreter \(interpreter.js:\d+:22\)$/);
@@ -295,10 +295,10 @@ function checkStack(stack, expected_lines) {
   } catch (e) {
     if (!(e instanceof TypeError)) throw e;
     checkStack(stripPath(e.stack), [
-      'TypeError: ' + kTrapMsgs[kTrapTypeError],                // -
-      '    at direct (wasm-function[1]:0x55)',                  // -
-      '    at main (wasm-function[3]:0x64)',                    // -
-      /^    at testIllegalImports \(interpreter.js:\d+:22\)$/,  // -
+      'TypeError: ' + kTrapMsgs[kTrapTypeError],               // -
+      '    at direct (<anonymous>:wasm-function[1]:0x55)',     // -
+      '    at main (<anonymous>:wasm-function[3]:0x64)',       // -
+      /^    at testIllegalImports \(interpreter.js:\d+:22\)$/, // -
       /^    at interpreter.js:\d+:3$/
     ]);
   }
@@ -308,10 +308,10 @@ function checkStack(stack, expected_lines) {
   } catch (e) {
     if (!(e instanceof TypeError)) throw e;
     checkStack(stripPath(e.stack), [
-      'TypeError: ' + kTrapMsgs[kTrapTypeError],                // -
-      '    at indirect (wasm-function[2]:0x5c)',                // -
-      '    at main (wasm-function[3]:0x64)',                    // -
-      /^    at testIllegalImports \(interpreter.js:\d+:22\)$/,  // -
+      'TypeError: ' + kTrapMsgs[kTrapTypeError],               // -
+      '    at indirect (<anonymous>:wasm-function[2]:0x5c)',   // -
+      '    at main (<anonymous>:wasm-function[3]:0x64)',       // -
+      /^    at testIllegalImports \(interpreter.js:\d+:22\)$/, // -
       /^    at interpreter.js:\d+:3$/
     ]);
   }
@@ -358,8 +358,8 @@ function checkStack(stack, expected_lines) {
     if (!(e instanceof RangeError)) throw e;
     checkStack(stripPath(e.stack), [
       'RangeError: Maximum call stack size exceeded',
-      '    at main (wasm-function[0]:0x20)'
-    ].concat(Array(9).fill('    at main (wasm-function[0]:0x22)')));
+      '    at main (<anonymous>:wasm-function[0]:0x20)'
+    ].concat(Array(9).fill('    at main (<anonymous>:wasm-function[0]:0x22)')));
   }
 })();
 
diff --git a/deps/v8/test/mjsunit/wasm/liftoff-simd-params.js b/deps/v8/test/mjsunit/wasm/liftoff-simd-params.js
new file mode 100644
index 0000000000..1ee7f74a32
--- /dev/null
+++ b/deps/v8/test/mjsunit/wasm/liftoff-simd-params.js
@@ -0,0 +1,77 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --experimental-wasm-simd
+
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+// This test case tries to exercise SIMD stack to stack movements by creating
+// a function that has many parameters.
+(function() {
+const builder = new WasmModuleBuilder();
+// At this point we have limited support for SIMD operations, but we can load
+// and store s128 values. So this memory will be used for reading and writing
+// s128 values and we will assert expected values from JS.
+builder.addImportedMemory('m', 'imported_mem', 1, 2);
+builder.addType(makeSig(new Array(18).fill(kWasmS128), []));
+
+builder.addFunction(undefined, makeSig([], []))
+    .addLocals({s128_count: 9})
+    .addBodyWithEnd([
+      // These will all be args to the callee.
+      // Load first arg from memory, this was written with values from JS.
+      kExprI32Const, 0,                     // i32.const
+      kSimdPrefix, kExprS128LoadMem, 0, 0,  // s128.load
+      kExprLocalGet, 0,                     // local.get
+      kExprLocalGet, 1,                     // local.get
+      kExprLocalGet, 2,                     // local.get
+      kExprLocalGet, 3,                     // local.get
+      kExprLocalGet, 4,                     // local.get
+      kExprLocalGet, 5,                     // local.get
+      kExprLocalGet, 6,                     // local.get
+      kExprLocalGet, 7,                     // local.get
+      kExprLocalGet, 8,                     // local.get
+      kExprLocalGet, 0,                     // local.get
+      kExprLocalGet, 1,                     // local.get
+      kExprLocalGet, 2,                     // local.get
+      kExprLocalGet, 3,                     // local.get
+      kExprLocalGet, 4,                     // local.get
+      kExprLocalGet, 5,                     // local.get
+      kExprLocalGet, 6,                     // local.get
+      // Load last s128 from memory, this was written with values from JS.
+      kExprI32Const, 16,                    // i32.const
+      kSimdPrefix, kExprS128LoadMem, 0, 0,  // s128.load
+      kExprCallFunction, 0x01,              // call
+      kExprEnd,                             // end
+    ]);
+
+builder.addFunction(undefined, 0 /* sig */).addBodyWithEnd([
+  kExprI32Const, 32,                     // i32.const
+  kExprLocalGet, 0,                      // local.get
+  kSimdPrefix, kExprS128StoreMem, 0, 0,  // s128.store
+  kExprI32Const, 48,                     // i32.const
+  kExprLocalGet, 17,                     // local.get
+  kSimdPrefix, kExprS128StoreMem, 0, 0,  // s128.store
+  kExprEnd,                              // end
+]);
+
+builder.addExport('main', 0);
+var memory = new WebAssembly.Memory({initial: 1, maximum: 2});
+const instance = builder.instantiate({m: {imported_mem: memory}});
+
+// We write sentinel values to two s128 values at the start of the memory.
+// Function 1 will read these values from memory, and pass them as the first
+// and last arg to function 2. Function 2 then write these values to memory
+// after these two s128 values.
+const arr = new Uint32Array(memory.buffer);
+for (let i = 0; i < 8; i++) {
+  arr[0] = i * 2;
+}
+
+instance.exports.main();
+
+for (let i = 0; i < 8; i++) {
+  assertEquals(arr[i], arr[i + 8]);
+}
+})();
diff --git a/deps/v8/test/mjsunit/wasm/many-modules.js b/deps/v8/test/mjsunit/wasm/many-modules.js
index 66db04237a..be235778b6 100644
--- a/deps/v8/test/mjsunit/wasm/many-modules.js
+++ b/deps/v8/test/mjsunit/wasm/many-modules.js
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // No reason to stress-opt this; save some time.
-// Flags: --wasm-far-jump-table --no-stress-opt
+// Flags: --no-stress-opt
 
 load('test/mjsunit/wasm/wasm-module-builder.js');
 
diff --git a/deps/v8/test/mjsunit/wasm/memory-external-call.js b/deps/v8/test/mjsunit/wasm/memory-external-call.js
index 1bb4bb1ecc..fed47b61fd 100644
--- a/deps/v8/test/mjsunit/wasm/memory-external-call.js
+++ b/deps/v8/test/mjsunit/wasm/memory-external-call.js
@@ -302,7 +302,7 @@ function assertMemoryIndependence(load_a, store_a, load_b, store_b) {
   assertMemoryIndependence(a.exports.load, table.get(1),
                            b.exports.load, table.get(0));
 
-  // Check that calling (from WASM) through the table maintains independence.
+  // Check that calling (from Wasm) through the table maintains independence.
   builder = new WasmModuleBuilder();
   builder.addImportedTable("m", "table", kTableSize, kTableSize);
   var sig_index = builder.addType(kSig_v_ii);
diff --git a/deps/v8/test/mjsunit/wasm/multiple-code-spaces.js b/deps/v8/test/mjsunit/wasm/multiple-code-spaces.js
index f180cf6234..2c1a1bd08e 100644
--- a/deps/v8/test/mjsunit/wasm/multiple-code-spaces.js
+++ b/deps/v8/test/mjsunit/wasm/multiple-code-spaces.js
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax --randomize-all-allocations
-// Flags: --wasm-far-jump-table --wasm-max-initial-code-space-reservation=1
+// Flags: --wasm-max-initial-code-space-reservation=1
 
 load('test/mjsunit/wasm/wasm-module-builder.js');
 
diff --git a/deps/v8/test/mjsunit/wasm/stack.js b/deps/v8/test/mjsunit/wasm/stack.js
index d6ae8541a6..1f3b8146da 100644
--- a/deps/v8/test/mjsunit/wasm/stack.js
+++ b/deps/v8/test/mjsunit/wasm/stack.js
@@ -23,7 +23,7 @@ function verifyStack(frames, expected) {
     assertContains(exp[4], frames[i].getFileName(), "["+i+"].getFileName()");
     var toString;
     if (exp[0]) {
-      toString = "wasm-function[" + exp[6] + "]:" + exp[5];
+      toString = "<anonymous>:wasm-function[" + exp[6] + "]:" + exp[5];
       if (exp[1] !== null) toString = exp[1] + " (" + toString + ")";
     } else {
       toString = exp[4] + ":" + exp[2] + ":";
@@ -69,10 +69,10 @@ var module = builder.instantiate({mod: {func: STACK}});
 (function testSimpleStack() {
   var expected_string = 'Error\n' +
       // The line numbers below will change as this test gains / loses lines..
-      '    at STACK (stack.js:38:11)\n' +            // --
-      '    at main (wasm-function[1]:0x86)\n' +      // --
-      '    at testSimpleStack (stack.js:77:18)\n' +  // --
-      '    at stack.js:79:3';                        // --
+      '    at STACK (stack.js:38:11)\n' +                   // --
+      '    at main (<anonymous>:wasm-function[1]:0x86)\n' + // --
+      '    at testSimpleStack (stack.js:77:18)\n' +         // --
+      '    at stack.js:79:3';                               // --
 
   module.exports.main();
   assertEquals(expected_string, stripPath(stack));
@@ -119,7 +119,7 @@ Error.prepareStackTrace = function(error, frames) {
     assertContains("out of bounds", e.message);
     verifyStack(e.stack, [
         // isWasm                  function   line  pos        file  offset funcIndex
-        [    true,                     null,     0,   3,       null, '0x91',        3],
+        [    true,      "mem_out_of_bounds",     0,   3,       null, '0x91',        3],
         [    true, "call_mem_out_of_bounds",     0,   1,       null, '0x97',        4],
         [   false, "testWasmMemOutOfBounds",   116,   0, "stack.js"],
         [   false,                     null,   128,   0, "stack.js"]
diff --git a/deps/v8/test/mjsunit/wasm/table-access.js b/deps/v8/test/mjsunit/wasm/table-access.js
index 3e718cf06c..7c1bf1eb19 100644
--- a/deps/v8/test/mjsunit/wasm/table-access.js
+++ b/deps/v8/test/mjsunit/wasm/table-access.js
@@ -138,6 +138,7 @@ const dummy_func = exports.set_table_func1;
   const function_index = builder.addFunction('hidden', sig_index)
                              .addBody([kExprI32Const, expected])
                              .index;
+  builder.addDeclarativeElementSegment([function_index]);
 
   builder.addFunction('main', kSig_i_v)
       .addBody([
diff --git a/deps/v8/test/mjsunit/wasm/table-fill.js b/deps/v8/test/mjsunit/wasm/table-fill.js
index 64c4d7732d..760c662c7f 100644
--- a/deps/v8/test/mjsunit/wasm/table-fill.js
+++ b/deps/v8/test/mjsunit/wasm/table-fill.js
@@ -93,8 +93,7 @@ function checkAnyRefTable(getter, start, count, value) {
 
 (function testAnyRefTableFillOOB() {
   print(arguments.callee.name);
-  // Fill table out-of-bounds, check if the table got filled as much as
-  // possible.
+  // Fill table out-of-bounds, check if the table wasn't altered.
   let start = 7;
   let value = {foo: 27};
   // {maximum + 4} elements definitely don't fit into the table.
@@ -103,14 +102,14 @@ function checkAnyRefTable(getter, start, count, value) {
       kTrapTableOutOfBounds,
       () => instance.exports[`fill${import_ref}`](start, value, count));
   checkAnyRefTable(
-      instance.exports[`get${import_ref}`], start, size - start, value);
+      instance.exports[`get${import_ref}`], start, size - start, null);
 
   value = 45;
   assertTraps(
       kTrapTableOutOfBounds,
       () => instance.exports[`fill${internal_ref}`](start, value, count));
   checkAnyRefTable(
-      instance.exports[`get${internal_ref}`], start, size - start, value);
+      instance.exports[`get${internal_ref}`], start, size - start, null);
 })();
 
 (function testAnyRefTableFillOOBCountZero() {
@@ -160,8 +159,7 @@ function checkAnyFuncTable(call, start, count, value) {
 
 (function testAnyFuncTableFillOOB() {
   print(arguments.callee.name);
-  // Fill table out-of-bounds, check if the table got filled as much as
-  // possible.
+  // Fill table out-of-bounds, check if the table wasn't altered.
   let start = 7;
   let value = 38;
   // {maximum + 4} elements definitely don't fit into the table.
@@ -171,7 +169,7 @@ function checkAnyFuncTable(call, start, count, value) {
       () => instance.exports[`fill${import_func}`](
           start, dummy_func(value), count));
   checkAnyFuncTable(
-      instance.exports[`call${import_func}`], start, size - start, value);
+      instance.exports[`call${import_func}`], start, size - start, null);
 
   value = 46;
   assertTraps(
@@ -179,7 +177,7 @@ function checkAnyFuncTable(call, start, count, value) {
       () => instance.exports[`fill${internal_func}`](
           start, dummy_func(value), count));
   checkAnyFuncTable(
-      instance.exports[`call${internal_func}`], start, size - start, value);
+      instance.exports[`call${internal_func}`], start, size - start, null);
 })();
 
 (function testAnyFuncTableFillOOBCountZero() {
diff --git a/deps/v8/test/mjsunit/wasm/tier-down-to-liftoff.js b/deps/v8/test/mjsunit/wasm/tier-down-to-liftoff.js
index bfd973c607..cbd763ddcd 100644
--- a/deps/v8/test/mjsunit/wasm/tier-down-to-liftoff.js
+++ b/deps/v8/test/mjsunit/wasm/tier-down-to-liftoff.js
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --liftoff --wasm-tier-up --no-stress-opt
+// Flags: --allow-natives-syntax
 
 load('test/mjsunit/wasm/wasm-module-builder.js');
 
-const num_functions = 2;
+const num_functions = 200;
 
 function create_builder(delta = 0) {
   const builder = new WasmModuleBuilder();
@@ -18,21 +18,37 @@ function create_builder(delta = 0) {
   return builder;
 }
 
-function check(instance) {
-  %WasmTierDownModule(instance);
+function checkTieredDown(instance) {
   for (let i = 0; i < num_functions; ++i) {
     assertTrue(%IsLiftoffFunction(instance.exports['f' + i]));
   }
+}
+
+function checkTieredUp(instance) {
+  // Busy waiting until all functions are tiered up.
+  let num_liftoff_functions;
+  while (true) {
+    num_liftoff_functions = 0;
+    for (let i = 0; i < num_functions; ++i) {
+      if (%IsLiftoffFunction(instance.exports['f' + i])) {
+        num_liftoff_functions++;
+      }
+    }
+    if (num_liftoff_functions == 0) return;
+  }
+}
+
+function check(instance) {
+  %WasmTierDownModule(instance);
+  checkTieredDown(instance);
 
   for (let i = 0; i < num_functions; ++i) {
     %WasmTierUpFunction(instance, i);
-    assertTrue(%IsLiftoffFunction(instance.exports['f' + i]));
   }
+  checkTieredDown(instance);
 
   %WasmTierUpModule(instance);
-  for (let i = 0; i < num_functions; ++i) {
-    assertFalse(%IsLiftoffFunction(instance.exports['f' + i]));
-  }
+  checkTieredUp(instance);
 }
 
 (function testTierDownToLiftoff() {
diff --git a/deps/v8/test/mjsunit/wasm/type-reflection.js b/deps/v8/test/mjsunit/wasm/type-reflection.js
index bac877d187..c0dfd8b26b 100644
--- a/deps/v8/test/mjsunit/wasm/type-reflection.js
+++ b/deps/v8/test/mjsunit/wasm/type-reflection.js
@@ -343,6 +343,39 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
     () => new WebAssembly.Function({parameters:[], results:[]}, _ => 0));
 })();
 
+(function TestFunctionConstructorWithWasmExportedFunction() {
+  let builder = new WasmModuleBuilder();
+
+  builder.addFunction('func1', kSig_v_i).addBody([]).exportFunc();
+  builder.addFunction('func2', kSig_v_v).addBody([]).exportFunc();
+
+  const instance = builder.instantiate();
+  assertThrows(
+      () => new WebAssembly.Function(
+          {parameters: [], results: []}, instance.exports.func1),
+      TypeError,
+      'WebAssembly.Function(): The signature of Argument 1 (a ' +
+      'WebAssembly function) does not match the signature specified in ' +
+      'Argument 0');
+
+  assertDoesNotThrow(
+      () => new WebAssembly.Function(
+          {parameters: [], results: []}, instance.exports.func2));
+})();
+
+(function TestFunctionConstructorWithWasmJSFunction() {
+  const func = new WebAssembly.Function({parameters: [], results: []}, _ => 0);
+
+  assertDoesNotThrow(
+      () => new WebAssembly.Function({parameters: [], results: []}, func));
+  assertThrows(
+      () => new WebAssembly.Function({parameters: ['i32'], results: []}, func),
+      TypeError,
+      'WebAssembly.Function(): The signature of Argument 1 (a ' +
+          'WebAssembly function) does not match the signature specified in ' +
+          'Argument 0');
+})();
+
 (function TestFunctionConstructorNonArray1() {
   let log = [];  // Populated with a log of accesses.
   let two = { toString: () => "2" };  // Just a fancy "2".
diff --git a/deps/v8/test/mjsunit/wasm/user-properties-exported.js b/deps/v8/test/mjsunit/wasm/user-properties-exported.js
index 0b2f249e05..ed71e37281 100644
--- a/deps/v8/test/mjsunit/wasm/user-properties-exported.js
+++ b/deps/v8/test/mjsunit/wasm/user-properties-exported.js
@@ -22,7 +22,7 @@ load("test/mjsunit/wasm/user-properties-common.js");
 
   testProperties(g);
 
-  // The WASM-internal fields of {g} are only inspected when {g} is
+  // The Wasm-internal fields of {g} are only inspected when {g} is
   // used as an import into another instance.
   print("  instance 2, importing");
   var builder = new WasmModuleBuilder();
diff --git a/deps/v8/test/mjsunit/wasm/user-properties-module.js b/deps/v8/test/mjsunit/wasm/user-properties-module.js
index 84727e1b53..e7a547df17 100644
--- a/deps/v8/test/mjsunit/wasm/user-properties-module.js
+++ b/deps/v8/test/mjsunit/wasm/user-properties-module.js
@@ -45,7 +45,7 @@ load("test/mjsunit/wasm/user-properties-common.js");
         assertEquals(f(j), g(j));
       }
       verifyHeap();
-      // The WASM-internal fields of {g} are only inspected when {g} is
+      // The Wasm-internal fields of {g} are only inspected when {g} is
       // used as an import into another instance. Use {g} as the import
       // the next time through the loop.
       f = g;
diff --git a/deps/v8/test/mjsunit/wasm/user-properties-reexport.js b/deps/v8/test/mjsunit/wasm/user-properties-reexport.js
index e4f155df5a..0f278b65c5 100644
--- a/deps/v8/test/mjsunit/wasm/user-properties-reexport.js
+++ b/deps/v8/test/mjsunit/wasm/user-properties-reexport.js
@@ -23,7 +23,7 @@ load("test/mjsunit/wasm/user-properties-common.js");
     testProperties(g);
     printName(" after", g);
 
-    // The WASM-internal fields of {g} are only inspected when {g} is
+    // The Wasm-internal fields of {g} are only inspected when {g} is
     // used as an import into another instance. Use {g} as the import
     // the next time through the loop.
     f = g;
diff --git a/deps/v8/test/mjsunit/wasm/wasm-module-builder.js b/deps/v8/test/mjsunit/wasm/wasm-module-builder.js
index 432353239d..845236cf2e 100644
--- a/deps/v8/test/mjsunit/wasm/wasm-module-builder.js
+++ b/deps/v8/test/mjsunit/wasm/wasm-module-builder.js
@@ -45,7 +45,7 @@ var kWasmV3 = 0;
 
 var kHeaderSize = 8;
 var kPageSize = 65536;
-var kSpecMaxPages = 65535;
+var kSpecMaxPages = 65536;
 var kMaxVarInt32Size = 5;
 var kMaxVarInt64Size = 10;
 
@@ -65,7 +65,7 @@ let kElementSectionCode = 9;     // Elements section
 let kCodeSectionCode = 10;       // Function code
 let kDataSectionCode = 11;       // Data segments
 let kDataCountSectionCode = 12;  // Data segment count (between Element & Code)
-let kExceptionSectionCode = 13;  // Exception section (between Global & Export)
+let kExceptionSectionCode = 13;  // Exception section (between Memory & Global)
 
 // Name section types
 let kModuleNameCode = 0;
@@ -82,7 +82,9 @@ let kSharedHasMaximumFlag = 3;
 let kActiveNoIndex = 0;
 let kPassive = 1;
 let kActiveWithIndex = 2;
+let kDeclarative = 3;
 let kPassiveWithElements = 5;
+let kDeclarativeWithElements = 7;
 
 // Function declaration flags
 let kDeclFunctionName   = 0x01;
@@ -468,9 +470,13 @@ let kExprI64AtomicCompareExchange32U = 0x4e;
 let kExprS128LoadMem = 0x00;
 let kExprS128StoreMem = 0x01;
 let kExprI32x4Splat = 0x0c;
+let kExprF32x4Splat = 0x12;
 let kExprI32x4Eq = 0x2c;
+let kExprS1x8AnyTrue = 0x63;
 let kExprS1x4AllTrue = 0x75;
+let kExprI32x4Add = 0x79;
 let kExprF32x4Min = 0x9e;
+let kExprS8x16LoadSplat = 0xc2;
 
 // Compilation hint constants.
 let kCompilationHintStrategyDefault = 0x00;
@@ -495,6 +501,8 @@ let kTrapUnalignedAccess      = 9;
 let kTrapDataSegmentDropped   = 10;
 let kTrapElemSegmentDropped   = 11;
 let kTrapTableOutOfBounds     = 12;
+let kTrapBrOnExnNullRef       = 13;
+let kTrapRethrowNullRef       = 14;
 
 let kTrapMsgs = [
   "unreachable",
@@ -509,7 +517,9 @@ let kTrapMsgs = [
   "operation does not support unaligned accesses",
   "data segment has been dropped",
   "element segment has been dropped",
-  "table access out of bounds"
+  "table access out of bounds",
+  "br_on_exn on nullref value",
+  "rethrowing nullref value"
 ];
 
 function assertTraps(trap, code) {
@@ -906,13 +916,26 @@ class WasmModuleBuilder {
   }
 
   addElementSegment(table, base, is_global, array) {
-    this.element_segments.push({table: table, base: base, is_global: is_global,
-                                    array: array, is_active: true});
+    this.element_segments.push({
+      table: table,
+      base: base,
+      is_global: is_global,
+      array: array,
+      is_active: true,
+      is_declarative: false
+    });
     return this;
   }
 
   addPassiveElementSegment(array, is_import = false) {
-    this.element_segments.push({array: array, is_active: false});
+    this.element_segments.push(
+        {array: array, is_active: false, is_declarative: false});
+    return this;
+  }
+
+  addDeclarativeElementSegment(array, is_import = false) {
+    this.element_segments.push(
+        {array: array, is_active: false, is_declarative: true});
     return this;
   }
 
@@ -1057,6 +1080,18 @@ class WasmModuleBuilder {
       });
     }
 
+    // Add event section.
+    if (wasm.exceptions.length > 0) {
+      if (debug) print("emitting events @ " + binary.length);
+      binary.emit_section(kExceptionSectionCode, section => {
+        section.emit_u32v(wasm.exceptions.length);
+        for (let type of wasm.exceptions) {
+          section.emit_u32v(kExceptionAttribute);
+          section.emit_u32v(type);
+        }
+      });
+    }
+
     // Add global section.
     if (wasm.globals.length > 0) {
       if (debug) print ("emitting globals @ " + binary.length);
@@ -1110,18 +1145,6 @@ class WasmModuleBuilder {
       });
     }
 
-    // Add exceptions.
-    if (wasm.exceptions.length > 0) {
-      if (debug) print("emitting exceptions @ " + binary.length);
-      binary.emit_section(kExceptionSectionCode, section => {
-        section.emit_u32v(wasm.exceptions.length);
-        for (let type of wasm.exceptions) {
-          section.emit_u32v(kExceptionAttribute);
-          section.emit_u32v(type);
-        }
-      });
-    }
-
     // Add export table.
     var mem_export = (wasm.memory !== undefined && wasm.memory.exp);
     var exports_count = wasm.exports.length + (mem_export ? 1 : 0);
@@ -1180,9 +1203,20 @@ class WasmModuleBuilder {
             for (let index of init.array) {
               section.emit_u32v(index);
             }
+          } else if (
+              init.is_declarative &&
+              init.array.every(index => index !== null)) {
+            section.emit_u8(kDeclarative);
+            section.emit_u8(kExternalFunction);
+            section.emit_u32v(init.array.length);
+            for (let index of init.array) {
+              section.emit_u32v(index);
+            }
           } else {
-            // Passive segment.
-            section.emit_u8(kPassiveWithElements);  // flags
+            // Passive or declarative segment with elements.
+            section.emit_u8(
+                init.is_declarative ? kDeclarativeWithElements :
+                                      kPassiveWithElements);  // flags
             section.emit_u8(kWasmAnyFunc);
             section.emit_u32v(init.array.length);
             for (let index of init.array) {
diff --git a/deps/v8/test/test262/test262.status b/deps/v8/test/test262/test262.status
index 99478a6dbf..c8603bd4fb 100644
--- a/deps/v8/test/test262/test262.status
+++ b/deps/v8/test/test262/test262.status
@@ -150,6 +150,12 @@
   'built-ins/TypedArray/prototype/copyWithin/coerced-values-end-detached-prototype': [FAIL],
   'built-ins/TypedArray/prototype/copyWithin/coerced-values-start-detached': [FAIL],
   'built-ins/TypedArray/prototype/copyWithin/coerced-values-end-detached': [FAIL],
+  # fill should also throw on detached buffers
+  'built-ins/TypedArray/prototype/fill/coerced-value-detach': [FAIL],
+  'built-ins/TypedArray/prototype/fill/coerced-end-detach': [FAIL],
+  'built-ins/TypedArray/prototype/fill/coerced-start-detach': [FAIL],
+  # includes should also throw on detached buffers
+  'built-ins/TypedArray/prototype/includes/detached-buffer-tointeger': [FAIL],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=4951
   'language/expressions/assignment/destructuring/iterator-destructuring-property-reference-target-evaluation-order': [FAIL],
@@ -496,17 +502,12 @@
   'language/comments/hashbang/use-strict': [SKIP],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=8179
-  # Temporarily removed pending https://github.com/tc39/test262/issues/2339
-  #
-  # These tests require exception handling support which is currently
-  #  blocked on landing https://chromium-review.googlesource.com/c/v8/v8/+/1655655
-  'built-ins/FinalizationGroup/FinalizationGroupCleanupIteratorPrototype/next-job-not-active-throws': [FAIL],
-  'built-ins/FinalizationGroup/prototype/cleanupSome/cleanup-throws-in-callback': [FAIL],
-  'built-ins/FinalizationGroup/prototype/cleanupSome/poisoned-callback-throws': [FAIL],
-  # 'built-ins/FinalizationGroup/prototype/cleanupSome/poisoned-cleanup-callback-throws': [FAIL],
+  'built-ins/FinalizationRegistry/FinalizationRegistryCleanupIteratorPrototype/next-job-not-active-throws': [FAIL],
+  'built-ins/FinalizationRegistry/prototype/cleanupSome/cleanup-throws-in-callback': [FAIL],
+  'built-ins/FinalizationRegistry/prototype/cleanupSome/poisoned-callback-throws': [FAIL],
 
-  # https://bugs.chromium.org/p/v8/issues/detail?id=9612
-  'intl402/DateTimeFormat/prototype/formatRange/fractionalSecondDigits': [FAIL],
+  # https://bugs.chromium.org/p/v8/issues/detail?id=10313
+  'built-ins/Date/parse/without-utc-offset': [SKIP],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=9613
   'intl402/Intl/getCanonicalLocales/canonicalized-tags': [FAIL],
@@ -535,7 +536,7 @@
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=10111
   # super() should evaluate arguments before checking IsConstructable
-  'language/expressions/class/super-evaluation-order': [FAIL],
+  'language/expressions/super/call-proto-not-ctor': [FAIL],
 
   # Intl.NumberFormat(..., {signDisplay:'exceptZero'}).format(0.0001)
   # produce +0 due to rounding
@@ -552,10 +553,9 @@
   'intl402/NumberFormat/prototype/formatToParts/signDisplay-ko-KR': [FAIL],
   'intl402/NumberFormat/prototype/formatToParts/signDisplay-zh-TW': [FAIL],
 
-  # Intl.NumberFormat constructor should throw RangeError
-  # https://bugs.chromium.org/p/v8/issues/detail?id=10112
-  'intl402/NumberFormat/constructor-order': [FAIL],
-  'intl402/NumberFormat/constructor-unit': [FAIL],
+  # https://bugs.chromium.org/p/v8/issues/detail?id=10272
+  'intl402/DateTimeFormat/invalid-numbering-system-calendar-options': [FAIL],
+  'intl402/NumberFormat/invalid-numbering-system-options': [FAIL],
 
   ######################## NEEDS INVESTIGATION ###########################
 
diff --git a/deps/v8/test/test262/testcfg.py b/deps/v8/test/test262/testcfg.py
index b971a22e5a..e1f1956392 100644
--- a/deps/v8/test/test262/testcfg.py
+++ b/deps/v8/test/test262/testcfg.py
@@ -53,7 +53,7 @@ FEATURE_FLAGS = {
   'Symbol.prototype.description': '--harmony-symbol-description',
   'export-star-as-namespace-from-module': '--harmony-namespace-exports',
   'Promise.allSettled': '--harmony-promise-all-settled',
-  'FinalizationGroup': '--harmony-weak-refs',
+  'FinalizationRegistry': '--harmony-weak-refs',
   'WeakRef': '--harmony-weak-refs',
   'host-gc-required': '--expose-gc-as=v8GC',
   'optional-chaining': '--harmony-optional-chaining',
diff --git a/deps/v8/test/torque/test-torque.tq b/deps/v8/test/torque/test-torque.tq
index 8948fd0eb0..0693878cce 100644
--- a/deps/v8/test/torque/test-torque.tq
+++ b/deps/v8/test/torque/test-torque.tq
@@ -767,7 +767,7 @@ namespace test {
     check(a.b.GetX() == 2);
   }
 
-  class InternalClass extends Struct {
+  class InternalClass extends HeapObject {
     macro Flip() labels NotASmi {
       const tmp = Cast<Smi>(this.b) otherwise NotASmi;
       this.b = this.a;
@@ -833,7 +833,7 @@ namespace test {
     return new FixedArray{map: kFixedArrayMap, length: 5, objects: ...i};
   }
 
-  class SmiPair extends Struct {
+  class SmiPair extends HeapObject {
     macro GetA():&Smi {
       return & this.a;
     }
@@ -920,7 +920,7 @@ namespace test {
     StaticAssert(1 + 2 == 3);
   }
 
-  class SmiBox extends Struct {
+  class SmiBox extends HeapObject {
     value: Smi;
     unrelated: Smi;
   }
@@ -1120,4 +1120,108 @@ namespace test {
     check(val3.d == 99);
     check(val3.e == 1234);
   }
+
+  @export
+  class ExportedSubClass extends ExportedSubClassBase {
+    c_field: int32;
+    d_field: int32;
+    e_field: Smi;
+  }
+
+  @export
+  class ExportedSubClassBase extends HeapObject {
+    a: HeapObject;
+    b: HeapObject;
+  }
+
+  class InternalClassWithSmiElements extends FixedArrayBase {
+    data: Smi;
+    object: Oddball;
+    entries[length]: Smi;
+  }
+
+  struct InternalClassStructElement {
+    a: Smi;
+    b: Smi;
+  }
+
+  class InternalClassWithStructElements extends HeapObject {
+    dummy1: int32;
+    dummy2: int32;
+    const count: Smi;
+    data: Smi;
+    object: Object;
+    entries[count]: Smi;
+    more_entries[count]: InternalClassStructElement;
+  }
+
+  struct SmiGeneratorIterator {
+    macro Next(): Smi labels _NoMore {
+      return this.value++;
+    }
+    value: Smi;
+  }
+
+  struct InternalClassStructElementGeneratorIterator {
+    macro Next(): InternalClassStructElement labels _NoMore {
+      return InternalClassStructElement{a: this.value++, b: this.value++};
+    }
+    value: Smi;
+  }
+
+  @export
+  macro TestFullyGeneratedClassWithElements() {
+    // Test creation, initialization and access of a fully generated class with
+    // simple (Smi) elements
+    const length: Smi = Convert<Smi>(3);
+    const object1 = new InternalClassWithSmiElements{
+      length,
+      data: 0,
+      object: Undefined,
+      entries: ...SmiGeneratorIterator {
+        value: 11
+      }
+    };
+    assert(object1.length == 3);
+    assert(object1.data == 0);
+    assert(object1.object == Undefined);
+    assert(object1.entries[0] == 11);
+    assert(object1.entries[1] == 12);
+    assert(object1.entries[2] == 13);
+
+    // Test creation, initialization and access of a fully generated class
+    // with elements that are a struct.
+    const object2 = new InternalClassWithStructElements{
+      dummy1: 44,
+      dummy2: 45,
+      count: length,
+      data: 55,
+      object: Undefined,
+      entries: ...SmiGeneratorIterator{value: 3},
+      more_entries: ...InternalClassStructElementGeneratorIterator {
+        value: 1
+      }
+    };
+
+    assert(object2.dummy1 == 44);
+    assert(object2.dummy2 == 45);
+    assert(object2.count == 3);
+    assert(object2.data == 55);
+    assert(object2.object == Undefined);
+    assert(object2.entries[0] == 3);
+    assert(object2.entries[1] == 4);
+    assert(object2.entries[2] == 5);
+    assert(object2.more_entries[0].a == 1);
+    assert(object2.more_entries[0].b == 2);
+    assert(object2.more_entries[1].a == 3);
+    assert(object2.more_entries[1].b == 4);
+    assert(object2.more_entries[2].a == 5);
+    assert(object2.more_entries[2].b == 6);
+  }
+
+  @export
+  macro TestFullyGeneratedClassFromCpp(): ExportedSubClass {
+    return new
+    ExportedSubClass{a: Null, b: Null, c_field: 7, d_field: 8, e_field: 9};
+  }
 }
diff --git a/deps/v8/test/unittests/BUILD.gn b/deps/v8/test/unittests/BUILD.gn
index ab407c2fe6..f3b060e5da 100644
--- a/deps/v8/test/unittests/BUILD.gn
+++ b/deps/v8/test/unittests/BUILD.gn
@@ -7,7 +7,7 @@ import("../../gni/v8.gni")
 if (is_fuchsia) {
   import("//build/config/fuchsia/rules.gni")
 
-  fuchsia_package("v8_unittests_pkg") {
+  cr_fuchsia_package("v8_unittests_pkg") {
     testonly = true
     binary = ":unittests"
     package_name_override = "v8_unittests"
@@ -20,6 +20,52 @@ if (is_fuchsia) {
   }
 }
 
+# Stand-alone target for C++ GC unittests. This is used to ensure that it
+# builds without V8 as well. They are also included in the regular unittests
+# target for simplicity.
+v8_executable("cppgc_unittests") {
+  testonly = true
+
+  configs = [
+    "../..:external_config",
+    "../..:internal_config_base",
+  ]
+
+  sources = [ "heap/cppgc/run-all-unittests.cc" ]
+
+  deps = [
+    ":cppgc_unittests_sources",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
+}
+
+v8_source_set("cppgc_unittests_sources") {
+  testonly = true
+
+  sources = [
+    "heap/cppgc/allocation_unittest.cc",
+    "heap/cppgc/finalizer-trait_unittest.cc",
+    "heap/cppgc/garbage-collected_unittest.cc",
+    "heap/cppgc/gc-info_unittest.cc",
+    "heap/cppgc/heap-object-header_unittest.cc",
+    "heap/cppgc/stack_unittest.cc",
+    "heap/cppgc/tests.cc",
+    "heap/cppgc/tests.h",
+  ]
+
+  configs = [
+    "../..:external_config",
+    "../..:internal_config_base",
+  ]
+
+  deps = [
+    "../..:cppgc_for_testing",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
+}
+
 v8_executable("unittests") {
   testonly = true
 
@@ -29,6 +75,7 @@ v8_executable("unittests") {
   #}],
 
   deps = [
+    ":cppgc_unittests_sources",
     ":unittests_sources",
     "../..:v8_for_testing",
     "../..:v8_libbase",
@@ -170,12 +217,13 @@ v8_source_set("unittests_sources") {
     "heap/heap-controller-unittest.cc",
     "heap/heap-unittest.cc",
     "heap/item-parallel-job-unittest.cc",
+    "heap/local-heap-unittest.cc",
     "heap/marking-unittest.cc",
     "heap/marking-worklist-unittest.cc",
     "heap/memory-reducer-unittest.cc",
     "heap/object-stats-unittest.cc",
     "heap/off-thread-factory-unittest.cc",
-    "heap/scavenge-job-unittest.cc",
+    "heap/safepoint-unittest.cc",
     "heap/slot-set-unittest.cc",
     "heap/spaces-unittest.cc",
     "heap/unmapper-unittest.cc",
diff --git a/deps/v8/test/unittests/api/access-check-unittest.cc b/deps/v8/test/unittests/api/access-check-unittest.cc
index 3b63666f4b..cdcce68efd 100644
--- a/deps/v8/test/unittests/api/access-check-unittest.cc
+++ b/deps/v8/test/unittests/api/access-check-unittest.cc
@@ -19,8 +19,7 @@ bool AccessCheck(Local<Context> accessing_context,
 
 MaybeLocal<Value> CompileRun(Isolate* isolate, const char* source) {
   Local<String> source_string =
-      String::NewFromUtf8(isolate, source, NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8(isolate, source).ToLocalChecked();
   Local<Context> context = isolate->GetCurrentContext();
   Local<Script> script =
       Script::Compile(context, source_string).ToLocalChecked();
@@ -28,9 +27,7 @@ MaybeLocal<Value> CompileRun(Isolate* isolate, const char* source) {
 }
 
 v8::Local<v8::String> v8_str(const char* x) {
-  return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x,
-                                 v8::NewStringType::kNormal)
-      .ToLocalChecked();
+  return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), x).ToLocalChecked();
 }
 
 }  // namespace
diff --git a/deps/v8/test/unittests/api/isolate-unittest.cc b/deps/v8/test/unittests/api/isolate-unittest.cc
index cda251f775..429d70617a 100644
--- a/deps/v8/test/unittests/api/isolate-unittest.cc
+++ b/deps/v8/test/unittests/api/isolate-unittest.cc
@@ -75,8 +75,7 @@ using IncumbentContextTest = TestWithIsolate;
 // scenarios.
 TEST_F(IncumbentContextTest, Basic) {
   auto Str = [&](const char* s) {
-    return String::NewFromUtf8(isolate(), s, NewStringType::kNormal)
-        .ToLocalChecked();
+    return String::NewFromUtf8(isolate(), s).ToLocalChecked();
   };
   auto Run = [&](Local<Context> context, const char* script) {
     Context::Scope scope(context);
diff --git a/deps/v8/test/unittests/api/remote-object-unittest.cc b/deps/v8/test/unittests/api/remote-object-unittest.cc
index 39434a8f9a..5fcc78bbe1 100644
--- a/deps/v8/test/unittests/api/remote-object-unittest.cc
+++ b/deps/v8/test/unittests/api/remote-object-unittest.cc
@@ -105,8 +105,7 @@ TEST_F(RemoteObjectTest, ClassOf) {
       AccessCheck, NamedPropertyHandlerConfiguration(NamedGetter),
       IndexedPropertyHandlerConfiguration());
   constructor_template->SetClassName(
-      String::NewFromUtf8(isolate(), "test_class", NewStringType::kNormal)
-          .ToLocalChecked());
+      String::NewFromUtf8Literal(isolate(), "test_class"));
 
   Local<Object> remote_object =
       constructor_template->NewRemoteInstance().ToLocalChecked();
diff --git a/deps/v8/test/unittests/api/v8-object-unittest.cc b/deps/v8/test/unittests/api/v8-object-unittest.cc
index eb72d45263..a3c0c2574c 100644
--- a/deps/v8/test/unittests/api/v8-object-unittest.cc
+++ b/deps/v8/test/unittests/api/v8-object-unittest.cc
@@ -20,9 +20,7 @@ TEST_F(ObjectTest, SetAccessorWhenUnconfigurablePropAlreadyDefined) {
   TryCatch try_catch(isolate());
 
   Local<Object> global = context()->Global();
-  Local<String> property_name =
-      String::NewFromUtf8(isolate(), "foo", NewStringType::kNormal)
-          .ToLocalChecked();
+  Local<String> property_name = String::NewFromUtf8Literal(isolate(), "foo");
 
   PropertyDescriptor prop_desc;
   prop_desc.set_configurable(false);
@@ -51,8 +49,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPrototype) {
   Local<FunctionTemplate> function_template = FunctionTemplate::New(isolate());
   Local<Signature> signature = Signature::New(isolate(), function_template);
   Local<String> property_key =
-      String::NewFromUtf8(isolate(), "property", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(isolate(), "property");
   Local<FunctionTemplate> get_or_set = FunctionTemplate::New(
       isolate(),
       [](const FunctionCallbackInfo<Value>& info) {
@@ -72,8 +69,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPrototype) {
   Local<Function> interface_for_prototype =
       function_template->GetFunction(prototype_context).ToLocalChecked();
   Local<String> prototype_key =
-      String::NewFromUtf8(isolate(), "prototype", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(isolate(), "prototype");
   Local<Object> prototype =
       interface_for_prototype->Get(caller_context, prototype_key)
           .ToLocalChecked()
@@ -91,9 +87,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPrototype) {
   EXPECT_EQ(2, call_count);
 
   // Test with a compiled version.
-  Local<String> object_key =
-      String::NewFromUtf8(isolate(), "object", NewStringType::kNormal)
-          .ToLocalChecked();
+  Local<String> object_key = String::NewFromUtf8Literal(isolate(), "object");
   caller_context->Global()->Set(caller_context, object_key, object).ToChecked();
   const char script[] =
       "function f() { object.property; object.property = 0; } "
@@ -103,10 +97,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPrototype) {
       "f();";
   Context::Scope scope(caller_context);
   internal::FLAG_allow_natives_syntax = true;
-  Script::Compile(
-      caller_context,
-      String::NewFromUtf8(isolate(), script, v8::NewStringType::kNormal)
-          .ToLocalChecked())
+  Script::Compile(caller_context, String::NewFromUtf8Literal(isolate(), script))
       .ToLocalChecked()
       ->Run(caller_context)
       .ToLocalChecked();
@@ -123,8 +114,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPlatformObject) {
   Local<FunctionTemplate> function_template = FunctionTemplate::New(isolate());
   Local<Signature> signature = Signature::New(isolate(), function_template);
   Local<String> property_key =
-      String::NewFromUtf8(isolate(), "property", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(isolate(), "property");
   Local<FunctionTemplate> get_or_set = FunctionTemplate::New(
       isolate(),
       [](const FunctionCallbackInfo<Value>& info) {
@@ -149,9 +139,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPlatformObject) {
   EXPECT_EQ(2, call_count);
 
   // Test with a compiled version.
-  Local<String> object_key =
-      String::NewFromUtf8(isolate(), "object", NewStringType::kNormal)
-          .ToLocalChecked();
+  Local<String> object_key = String::NewFromUtf8Literal(isolate(), "object");
   caller_context->Global()->Set(caller_context, object_key, object).ToChecked();
   const char script[] =
       "function f() { object.property; object.property = 0; } "
@@ -161,10 +149,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnPlatformObject) {
       "f();";
   Context::Scope scope(caller_context);
   internal::FLAG_allow_natives_syntax = true;
-  Script::Compile(
-      caller_context,
-      String::NewFromUtf8(isolate(), script, v8::NewStringType::kNormal)
-          .ToLocalChecked())
+  Script::Compile(caller_context, String::NewFromUtf8Literal(isolate(), script))
       .ToLocalChecked()
       ->Run(caller_context)
       .ToLocalChecked();
@@ -180,8 +165,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnInterface) {
 
   Local<FunctionTemplate> function_template = FunctionTemplate::New(isolate());
   Local<String> property_key =
-      String::NewFromUtf8(isolate(), "property", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(isolate(), "property");
   Local<FunctionTemplate> get_or_set = FunctionTemplate::New(
       isolate(),
       [](const FunctionCallbackInfo<Value>& info) {
@@ -204,8 +188,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnInterface) {
 
   // Test with a compiled version.
   Local<String> interface_key =
-      String::NewFromUtf8(isolate(), "Interface", NewStringType::kNormal)
-          .ToLocalChecked();
+      String::NewFromUtf8Literal(isolate(), "Interface");
   caller_context->Global()
       ->Set(caller_context, interface_key, interface)
       .ToChecked();
@@ -217,10 +200,7 @@ TEST_F(LapContextTest, CurrentContextInLazyAccessorOnInterface) {
       "f();";
   Context::Scope scope(caller_context);
   internal::FLAG_allow_natives_syntax = true;
-  Script::Compile(
-      caller_context,
-      String::NewFromUtf8(isolate(), script, v8::NewStringType::kNormal)
-          .ToLocalChecked())
+  Script::Compile(caller_context, String::NewFromUtf8Literal(isolate(), script))
       .ToLocalChecked()
       ->Run(caller_context)
       .ToLocalChecked();
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-arm-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-arm-unittest.cc
index 76dd04d77c..2c0c01701c 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-arm-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-arm-unittest.cc
@@ -32,14 +32,15 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -49,8 +50,9 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter is 17.
@@ -60,7 +62,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-arm64-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-arm64-unittest.cc
index 02a6a8e763..0a9ac748c0 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-arm64-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-arm64-unittest.cc
@@ -32,14 +32,17 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
+  __ CodeEntry();
+
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -49,10 +52,13 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
+  __ CodeEntry();
+
   // Fail if the first parameter is 17.
   __ Mov(w1, Immediate(17));
   __ Cmp(w0, w1);  // 1st parameter is in {w0}.
@@ -60,7 +66,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
@@ -113,6 +119,7 @@ TEST_P(TurboAssemblerTestMoveObjectAndSlot, MoveObjectAndSlot) {
     TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
                         buffer->CreateView());
 
+    __ CodeEntry();
     __ Push(x0, padreg);
     __ Mov(test_case.object, x1);
 
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-ia32-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-ia32-unittest.cc
index 548cb34fc7..f0cb96d47d 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-ia32-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-ia32-unittest.cc
@@ -5,6 +5,7 @@
 #include "src/codegen/macro-assembler.h"
 #include "src/execution/simulator.h"
 #include "test/common/assembler-tester.h"
+#include "test/unittests/test-utils.h"
 #include "testing/gtest-support.h"
 
 namespace v8 {
@@ -16,26 +17,30 @@ namespace internal {
 // a buffer and executing them.  These tests do not initialize the
 // V8 library, create a context, or use any V8 objects.
 
-TEST(TurboAssemblerTest, TestHardAbort) {
+class TurboAssemblerTest : public TestWithIsolate {};
+
+TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
-  auto f = GeneratedCode<void>::FromBuffer(nullptr, buffer->start());
+  auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
 
   ASSERT_DEATH_IF_SUPPORTED({ f.Call(); }, "abort: no reason");
 }
 
-TEST(TurboAssemblerTest, TestCheck) {
+TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter is 17.
@@ -45,9 +50,9 @@ TEST(TurboAssemblerTest, TestCheck) {
   __ ret(0);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
-  auto f = GeneratedCode<void, int>::FromBuffer(nullptr, buffer->start());
+  auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
 
   f.Call(0);
   f.Call(18);
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-mips-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-mips-unittest.cc
index 5ea6b2f3f8..b8a645e6a7 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-mips-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-mips-unittest.cc
@@ -22,14 +22,15 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -39,8 +40,9 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter (in {a0}) is 17.
@@ -48,7 +50,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-mips64-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-mips64-unittest.cc
index fe9e815981..c954ffcc65 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-mips64-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-mips64-unittest.cc
@@ -22,14 +22,15 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -39,8 +40,9 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter (in {a0}) is 17.
@@ -48,7 +50,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-ppc-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-ppc-unittest.cc
index 51744bd92d..08c205c2ea 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-ppc-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-ppc-unittest.cc
@@ -22,15 +22,15 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
-
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -40,9 +40,9 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
-
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter is 17.
@@ -52,7 +52,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-s390-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-s390-unittest.cc
index 959ec03157..b0c398f571 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-s390-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-s390-unittest.cc
@@ -22,14 +22,15 @@ class TurboAssemblerTest : public TestWithIsolate {};
 
 TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
@@ -39,8 +40,9 @@ TEST_F(TurboAssemblerTest, TestHardAbort) {
 
 TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter is 17.
@@ -50,7 +52,7 @@ TEST_F(TurboAssemblerTest, TestCheck) {
   __ Ret();
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
   // We need an isolate here to execute in the simulator.
   auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
diff --git a/deps/v8/test/unittests/assembler/turbo-assembler-x64-unittest.cc b/deps/v8/test/unittests/assembler/turbo-assembler-x64-unittest.cc
index 621f598f75..43dd6b79d6 100644
--- a/deps/v8/test/unittests/assembler/turbo-assembler-x64-unittest.cc
+++ b/deps/v8/test/unittests/assembler/turbo-assembler-x64-unittest.cc
@@ -5,6 +5,7 @@
 #include "src/codegen/macro-assembler.h"
 #include "src/execution/simulator.h"
 #include "test/common/assembler-tester.h"
+#include "test/unittests/test-utils.h"
 #include "testing/gtest-support.h"
 
 namespace v8 {
@@ -16,26 +17,30 @@ namespace internal {
 // a buffer and executing them.  These tests do not initialize the
 // V8 library, create a context, or use any V8 objects.
 
-TEST(TurboAssemblerTest, TestHardAbort) {
+class TurboAssemblerTest : public TestWithIsolate {};
+
+TEST_F(TurboAssemblerTest, TestHardAbort) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   __ Abort(AbortReason::kNoReason);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
-  auto f = GeneratedCode<void>::FromBuffer(nullptr, buffer->start());
+  auto f = GeneratedCode<void>::FromBuffer(isolate(), buffer->start());
 
   ASSERT_DEATH_IF_SUPPORTED({ f.Call(); }, "abort: no reason");
 }
 
-TEST(TurboAssemblerTest, TestCheck) {
+TEST_F(TurboAssemblerTest, TestCheck) {
   auto buffer = AllocateAssemblerBuffer();
-  TurboAssembler tasm(nullptr, AssemblerOptions{}, CodeObjectRequired::kNo,
+  TurboAssembler tasm(isolate(), AssemblerOptions{}, CodeObjectRequired::kNo,
                       buffer->CreateView());
+  __ set_root_array_available(false);
   __ set_abort_hard(true);
 
   // Fail if the first parameter is 17.
@@ -45,9 +50,9 @@ TEST(TurboAssemblerTest, TestCheck) {
   __ ret(0);
 
   CodeDesc desc;
-  tasm.GetCode(nullptr, &desc);
+  tasm.GetCode(isolate(), &desc);
   buffer->MakeExecutable();
-  auto f = GeneratedCode<void, int>::FromBuffer(nullptr, buffer->start());
+  auto f = GeneratedCode<void, int>::FromBuffer(isolate(), buffer->start());
 
   f.Call(0);
   f.Call(18);
diff --git a/deps/v8/test/unittests/base/platform/platform-unittest.cc b/deps/v8/test/unittests/base/platform/platform-unittest.cc
index 27154b3c24..b447778b49 100644
--- a/deps/v8/test/unittests/base/platform/platform-unittest.cc
+++ b/deps/v8/test/unittests/base/platform/platform-unittest.cc
@@ -83,5 +83,18 @@ TEST_F(ThreadLocalStorageTest, DoTest) {
   Join();
 }
 
+TEST(StackTest, GetStackStart) { EXPECT_NE(nullptr, Stack::GetStackStart()); }
+
+TEST(StackTest, GetCurrentStackPosition) {
+  EXPECT_NE(nullptr, Stack::GetCurrentStackPosition());
+}
+
+TEST(StackTest, StackVariableInBounds) {
+  void* dummy;
+  ASSERT_GT(Stack::GetStackStart(), Stack::GetCurrentStackPosition());
+  EXPECT_GT(Stack::GetStackStart(), Stack::GetStackSlot(&dummy));
+  EXPECT_LT(Stack::GetCurrentStackPosition(), Stack::GetStackSlot(&dummy));
+}
+
 }  // namespace base
 }  // namespace v8
diff --git a/deps/v8/test/unittests/base/region-allocator-unittest.cc b/deps/v8/test/unittests/base/region-allocator-unittest.cc
index caec4894c9..df154ff4f3 100644
--- a/deps/v8/test/unittests/base/region-allocator-unittest.cc
+++ b/deps/v8/test/unittests/base/region-allocator-unittest.cc
@@ -14,9 +14,7 @@ using Address = RegionAllocator::Address;
 using v8::internal::KB;
 using v8::internal::MB;
 
-class RegionAllocatorTest : public ::testing::TestWithParam<int> {};
-
-TEST_P(RegionAllocatorTest, SimpleAllocateRegionAt) {
+TEST(RegionAllocatorTest, SimpleAllocateRegionAt) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCount = 16;
   const size_t kSize = kPageSize * kPageCount;
@@ -50,7 +48,7 @@ TEST_P(RegionAllocatorTest, SimpleAllocateRegionAt) {
   CHECK_EQ(ra.AllocateRegion(kSize), kBegin);
 }
 
-TEST_P(RegionAllocatorTest, SimpleAllocateRegion) {
+TEST(RegionAllocatorTest, SimpleAllocateRegion) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCount = 16;
   const size_t kSize = kPageSize * kPageCount;
@@ -79,7 +77,7 @@ TEST_P(RegionAllocatorTest, SimpleAllocateRegion) {
   CHECK_EQ(ra.free_size(), 0);
 }
 
-TEST_P(RegionAllocatorTest, AllocateRegionRandom) {
+TEST(RegionAllocatorTest, AllocateRegionRandom) {
   const size_t kPageSize = 8 * KB;
   const size_t kPageCountLog = 16;
   const size_t kPageCount = (size_t{1} << kPageCountLog);
@@ -87,7 +85,7 @@ TEST_P(RegionAllocatorTest, AllocateRegionRandom) {
   const Address kBegin = static_cast<Address>(153 * MB);
   const Address kEnd = kBegin + kSize;
 
-  base::RandomNumberGenerator rng(GetParam());
+  base::RandomNumberGenerator rng(::testing::FLAGS_gtest_random_seed);
   RegionAllocator ra(kBegin, kSize, kPageSize);
 
   std::set<Address> allocated_pages;
@@ -123,7 +121,7 @@ TEST_P(RegionAllocatorTest, AllocateRegionRandom) {
   CHECK_EQ(ra.AllocateRegion(kPageSize), RegionAllocator::kAllocationFailure);
 }
 
-TEST_P(RegionAllocatorTest, AllocateBigRegions) {
+TEST(RegionAllocatorTest, AllocateBigRegions) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCountLog = 10;
   const size_t kPageCount = (size_t{1} << kPageCountLog) - 1;
@@ -153,7 +151,7 @@ TEST_P(RegionAllocatorTest, AllocateBigRegions) {
   CHECK_EQ(ra.free_size(), 0);
 }
 
-TEST_P(RegionAllocatorTest, MergeLeftToRightCoalecsingRegions) {
+TEST(RegionAllocatorTest, MergeLeftToRightCoalecsingRegions) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCountLog = 10;
   const size_t kPageCount = (size_t{1} << kPageCountLog);
@@ -187,8 +185,8 @@ TEST_P(RegionAllocatorTest, MergeLeftToRightCoalecsingRegions) {
   CHECK_EQ(ra.free_size(), 0);
 }
 
-TEST_P(RegionAllocatorTest, MergeRightToLeftCoalecsingRegions) {
-  base::RandomNumberGenerator rng(GetParam());
+TEST(RegionAllocatorTest, MergeRightToLeftCoalecsingRegions) {
+  base::RandomNumberGenerator rng(::testing::FLAGS_gtest_random_seed);
   const size_t kPageSize = 4 * KB;
   const size_t kPageCountLog = 10;
   const size_t kPageCount = (size_t{1} << kPageCountLog);
@@ -236,7 +234,7 @@ TEST_P(RegionAllocatorTest, MergeRightToLeftCoalecsingRegions) {
   CHECK_EQ(ra.AllocateRegion(kSize), kBegin);
 }
 
-TEST_P(RegionAllocatorTest, Fragmentation) {
+TEST(RegionAllocatorTest, Fragmentation) {
   const size_t kPageSize = 64 * KB;
   const size_t kPageCount = 9;
   const size_t kSize = kPageSize * kPageCount;
@@ -283,7 +281,7 @@ TEST_P(RegionAllocatorTest, Fragmentation) {
   CHECK_EQ(ra.AllocateRegion(kSize), kBegin);
 }
 
-TEST_P(RegionAllocatorTest, FindRegion) {
+TEST(RegionAllocatorTest, FindRegion) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCount = 16;
   const size_t kSize = kPageSize * kPageCount;
@@ -322,7 +320,7 @@ TEST_P(RegionAllocatorTest, FindRegion) {
   }
 }
 
-TEST_P(RegionAllocatorTest, TrimRegion) {
+TEST(RegionAllocatorTest, TrimRegion) {
   const size_t kPageSize = 4 * KB;
   const size_t kPageCount = 64;
   const size_t kSize = kPageSize * kPageCount;
@@ -352,7 +350,5 @@ TEST_P(RegionAllocatorTest, TrimRegion) {
   CHECK_EQ(ra.AllocateRegion(kSize), kBegin);
 }
 
-INSTANTIATE_TEST_SUITE_P(RegionAllocatorTest, RegionAllocatorTest,
-                         testing::Values(123));
 }  // namespace base
 }  // namespace v8
diff --git a/deps/v8/test/unittests/compiler/backend/instruction-selector-unittest.cc b/deps/v8/test/unittests/compiler/backend/instruction-selector-unittest.cc
index 95191819a8..9607aa94a9 100644
--- a/deps/v8/test/unittests/compiler/backend/instruction-selector-unittest.cc
+++ b/deps/v8/test/unittests/compiler/backend/instruction-selector-unittest.cc
@@ -338,7 +338,8 @@ TARGET_TEST_F(InstructionSelectorTest, CallJSFunctionWithDeopt) {
   Node* context = m.Parameter(2);
 
   ZoneVector<MachineType> int32_type(1, MachineType::Int32(), zone());
-  ZoneVector<MachineType> empty_types(zone());
+  ZoneVector<MachineType> tagged_type(1, MachineType::AnyTagged(), zone());
+  ZoneVector<MachineType> empty_type(zone());
 
   auto call_descriptor = Linkage::GetJSCallDescriptor(
       zone(), false, 1,
@@ -349,9 +350,10 @@ TARGET_TEST_F(InstructionSelectorTest, CallJSFunctionWithDeopt) {
       m.common()->TypedStateValues(&int32_type, SparseInputMask::Dense()),
       m.Int32Constant(1));
   Node* locals = m.AddNode(
-      m.common()->TypedStateValues(&empty_types, SparseInputMask::Dense()));
+      m.common()->TypedStateValues(&empty_type, SparseInputMask::Dense()));
   Node* stack = m.AddNode(
-      m.common()->TypedStateValues(&empty_types, SparseInputMask::Dense()));
+      m.common()->TypedStateValues(&tagged_type, SparseInputMask::Dense()),
+      m.UndefinedConstant());
   Node* context_sentinel = m.Int32Constant(0);
   Node* state_node = m.AddNode(
       m.common()->FrameState(bailout_id, OutputFrameStateCombine::PokeAt(0),
@@ -487,7 +489,6 @@ TARGET_TEST_F(InstructionSelectorTest, CallStubWithDeoptRecursiveFrameState) {
   Node* context2 = m.Int32Constant(46);
 
   ZoneVector<MachineType> int32_type(1, MachineType::Int32(), zone());
-  ZoneVector<MachineType> int32x2_type(2, MachineType::Int32(), zone());
   ZoneVector<MachineType> float64_type(1, MachineType::Float64(), zone());
 
   Callable callable = Builtins::CallableFor(isolate(), Builtins::kToObject);
@@ -518,8 +519,8 @@ TARGET_TEST_F(InstructionSelectorTest, CallStubWithDeoptRecursiveFrameState) {
       m.common()->TypedStateValues(&float64_type, SparseInputMask::Dense()),
       m.Float64Constant(0.25));
   Node* stack2 = m.AddNode(
-      m.common()->TypedStateValues(&int32x2_type, SparseInputMask::Dense()),
-      m.Int32Constant(44), m.Int32Constant(45));
+      m.common()->TypedStateValues(&int32_type, SparseInputMask::Dense()),
+      m.Int32Constant(44));
   Node* state_node =
       m.AddNode(m.common()->FrameState(bailout_id_before,
                                        OutputFrameStateCombine::PokeAt(0),
@@ -550,7 +551,7 @@ TARGET_TEST_F(InstructionSelectorTest, CallStubWithDeoptRecursiveFrameState) {
       1 +  // Code object.
       1 +  // Poison index.
       1 +  // Frame state deopt id
-      6 +  // One input for each value in frame state + context.
+      5 +  // One input for each value in frame state + context.
       5 +  // One input for each value in the parent frame state + context.
       1 +  // Function.
       1;   // Context.
@@ -576,17 +577,16 @@ TARGET_TEST_F(InstructionSelectorTest, CallStubWithDeoptRecursiveFrameState) {
   // Values from the nested frame.
   EXPECT_EQ(1u, desc_before->parameters_count());
   EXPECT_EQ(1u, desc_before->locals_count());
-  EXPECT_EQ(2u, desc_before->stack_count());
+  EXPECT_EQ(1u, desc_before->stack_count());
   EXPECT_EQ(43, s.ToInt32(call_instr->InputAt(9)));
   EXPECT_EQ(46, s.ToInt32(call_instr->InputAt(10)));
   EXPECT_EQ(0.25, s.ToFloat64(call_instr->InputAt(11)));
   EXPECT_EQ(44, s.ToInt32(call_instr->InputAt(12)));
-  EXPECT_EQ(45, s.ToInt32(call_instr->InputAt(13)));
 
   // Function.
-  EXPECT_EQ(s.ToVreg(function_node), s.ToVreg(call_instr->InputAt(14)));
+  EXPECT_EQ(s.ToVreg(function_node), s.ToVreg(call_instr->InputAt(13)));
   // Context.
-  EXPECT_EQ(s.ToVreg(context2), s.ToVreg(call_instr->InputAt(15)));
+  EXPECT_EQ(s.ToVreg(context2), s.ToVreg(call_instr->InputAt(14)));
   // Continuation.
 
   EXPECT_EQ(kArchRet, s[index++]->arch_opcode());
diff --git a/deps/v8/test/unittests/compiler/bytecode-analysis-unittest.cc b/deps/v8/test/unittests/compiler/bytecode-analysis-unittest.cc
index d3c81344f2..c6fe8948bc 100644
--- a/deps/v8/test/unittests/compiler/bytecode-analysis-unittest.cc
+++ b/deps/v8/test/unittests/compiler/bytecode-analysis-unittest.cc
@@ -256,7 +256,7 @@ TEST_F(BytecodeAnalysisTest, SimpleLoop) {
     expected_liveness.emplace_back("L..L", "L.L.");
 
     loop_builder.BindContinueTarget();
-    loop_builder.JumpToHeader(0);
+    loop_builder.JumpToHeader(0, nullptr);
     expected_liveness.emplace_back("L.L.", "L.L.");
   }
 
@@ -361,7 +361,7 @@ TEST_F(BytecodeAnalysisTest, DiamondInLoop) {
     builder.Bind(&end_label);
 
     loop_builder.BindContinueTarget();
-    loop_builder.JumpToHeader(0);
+    loop_builder.JumpToHeader(0, nullptr);
     expected_liveness.emplace_back("L...", "L...");
   }
 
@@ -433,12 +433,12 @@ TEST_F(BytecodeAnalysisTest, KillingLoopInsideLoop) {
       expected_liveness.emplace_back("LL.L", "LL..");
 
       inner_loop_builder.BindContinueTarget();
-      inner_loop_builder.JumpToHeader(1);
+      inner_loop_builder.JumpToHeader(1, &loop_builder);
       expected_liveness.emplace_back(".L..", ".L..");
     }
 
     loop_builder.BindContinueTarget();
-    loop_builder.JumpToHeader(0);
+    loop_builder.JumpToHeader(0, nullptr);
     expected_liveness.emplace_back("LL..", "LL..");
   }
 
diff --git a/deps/v8/test/unittests/compiler/constant-folding-reducer-unittest.cc b/deps/v8/test/unittests/compiler/constant-folding-reducer-unittest.cc
index dee5c56e82..4f3d05173d 100644
--- a/deps/v8/test/unittests/compiler/constant-folding-reducer-unittest.cc
+++ b/deps/v8/test/unittests/compiler/constant-folding-reducer-unittest.cc
@@ -80,6 +80,12 @@ class ConstantFoldingReducerTest : public TypedGraphTest {
     return reducer.Reduce(node);
   }
 
+  Node* UseValue(Node* node) {
+    Node* start = graph()->NewNode(common()->Start(1));
+    Node* zero = graph()->NewNode(common()->NumberConstant(0));
+    return graph()->NewNode(common()->Return(), zero, node, start, start);
+  }
+
   SimplifiedOperatorBuilder* simplified() { return &simplified_; }
   JSHeapBroker* broker() { return &broker_; }
 
@@ -91,20 +97,26 @@ class ConstantFoldingReducerTest : public TypedGraphTest {
 
 TEST_F(ConstantFoldingReducerTest, ParameterWithMinusZero) {
   {
-    Reduction r = Reduce(Parameter(
-        Type::NewConstant(broker(), factory()->minus_zero_value(), zone())));
+    Node* node = Parameter(
+        Type::Constant(broker(), factory()->minus_zero_value(), zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(-0.0));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(-0.0));
   }
   {
-    Reduction r = Reduce(Parameter(Type::MinusZero()));
+    Node* node = Parameter(Type::MinusZero());
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(-0.0));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(-0.0));
   }
   {
-    Reduction r = Reduce(Parameter(Type::Union(
+    Node* node = Parameter(Type::Union(
         Type::MinusZero(),
-        Type::NewConstant(broker(), factory()->NewNumber(0), zone()), zone())));
+        Type::Constant(broker(), factory()->NewNumber(0), zone()), zone()));
+    UseValue(node);
+    Reduction r = Reduce(node);
     EXPECT_FALSE(r.Changed());
   }
 }
@@ -112,14 +124,18 @@ TEST_F(ConstantFoldingReducerTest, ParameterWithMinusZero) {
 TEST_F(ConstantFoldingReducerTest, ParameterWithNull) {
   Handle<HeapObject> null = factory()->null_value();
   {
-    Reduction r = Reduce(Parameter(Type::NewConstant(broker(), null, zone())));
+    Node* node = Parameter(Type::Constant(broker(), null, zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsHeapConstant(null));
+    EXPECT_THAT(use_value->InputAt(1), IsHeapConstant(null));
   }
   {
-    Reduction r = Reduce(Parameter(Type::Null()));
+    Node* node = Parameter(Type::Null());
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsHeapConstant(null));
+    EXPECT_THAT(use_value->InputAt(1), IsHeapConstant(null));
   }
 }
 
@@ -129,51 +145,62 @@ TEST_F(ConstantFoldingReducerTest, ParameterWithNaN) {
                           std::numeric_limits<double>::signaling_NaN()};
   TRACED_FOREACH(double, nan, kNaNs) {
     Handle<Object> constant = factory()->NewNumber(nan);
-    Reduction r =
-        Reduce(Parameter(Type::NewConstant(broker(), constant, zone())));
+    Node* node = Parameter(Type::Constant(broker(), constant, zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(IsNaN()));
   }
   {
-    Reduction r = Reduce(
-        Parameter(Type::NewConstant(broker(), factory()->nan_value(), zone())));
+    Node* node =
+        Parameter(Type::Constant(broker(), factory()->nan_value(), zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(IsNaN()));
   }
   {
-    Reduction r = Reduce(Parameter(Type::NaN()));
+    Node* node = Parameter(Type::NaN());
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(IsNaN()));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(IsNaN()));
   }
 }
 
 TEST_F(ConstantFoldingReducerTest, ParameterWithPlainNumber) {
   TRACED_FOREACH(double, value, kFloat64Values) {
     Handle<Object> constant = factory()->NewNumber(value);
-    Reduction r =
-        Reduce(Parameter(Type::NewConstant(broker(), constant, zone())));
+    Node* node = Parameter(Type::Constant(broker(), constant, zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(value));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(value));
   }
   TRACED_FOREACH(double, value, kIntegerValues) {
-    Reduction r = Reduce(Parameter(Type::Range(value, value, zone())));
+    Node* node = Parameter(Type::Range(value, value, zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsNumberConstant(value));
+    EXPECT_THAT(use_value->InputAt(1), IsNumberConstant(value));
   }
 }
 
 TEST_F(ConstantFoldingReducerTest, ParameterWithUndefined) {
   Handle<HeapObject> undefined = factory()->undefined_value();
   {
-    Reduction r = Reduce(Parameter(Type::Undefined()));
+    Node* node = Parameter(Type::Undefined());
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsHeapConstant(undefined));
+    EXPECT_THAT(use_value->InputAt(1), IsUndefinedConstant());
   }
   {
-    Reduction r =
-        Reduce(Parameter(Type::NewConstant(broker(), undefined, zone())));
+    Node* node = Parameter(Type::Constant(broker(), undefined, zone()));
+    Node* use_value = UseValue(node);
+    Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsHeapConstant(undefined));
+    EXPECT_THAT(use_value->InputAt(1), IsUndefinedConstant());
   }
 }
 
@@ -193,8 +220,8 @@ TEST_F(ConstantFoldingReducerTest, ToBooleanWithFalsish) {
                       Type::Union(
                           Type::Undetectable(),
                           Type::Union(
-                              Type::NewConstant(
-                                  broker(), factory()->false_value(), zone()),
+                              Type::Constant(broker(), factory()->false_value(),
+                                             zone()),
                               Type::Range(0.0, 0.0, zone()), zone()),
                           zone()),
                       zone()),
@@ -202,28 +229,34 @@ TEST_F(ConstantFoldingReducerTest, ToBooleanWithFalsish) {
               zone()),
           zone()),
       0);
-  Reduction r = Reduce(graph()->NewNode(simplified()->ToBoolean(), input));
+  Node* node = graph()->NewNode(simplified()->ToBoolean(), input);
+  Node* use_value = UseValue(node);
+  Reduction r = Reduce(node);
   ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(r.replacement(), IsFalseConstant());
+  EXPECT_THAT(use_value->InputAt(1), IsFalseConstant());
 }
 
 TEST_F(ConstantFoldingReducerTest, ToBooleanWithTruish) {
   Node* input = Parameter(
       Type::Union(
-          Type::NewConstant(broker(), factory()->true_value(), zone()),
+          Type::Constant(broker(), factory()->true_value(), zone()),
           Type::Union(Type::DetectableReceiver(), Type::Symbol(), zone()),
           zone()),
       0);
-  Reduction r = Reduce(graph()->NewNode(simplified()->ToBoolean(), input));
+  Node* node = graph()->NewNode(simplified()->ToBoolean(), input);
+  Node* use_value = UseValue(node);
+  Reduction r = Reduce(node);
   ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(r.replacement(), IsTrueConstant());
+  EXPECT_THAT(use_value->InputAt(1), IsTrueConstant());
 }
 
 TEST_F(ConstantFoldingReducerTest, ToBooleanWithNonZeroPlainNumber) {
   Node* input = Parameter(Type::Range(1, V8_INFINITY, zone()), 0);
-  Reduction r = Reduce(graph()->NewNode(simplified()->ToBoolean(), input));
+  Node* node = graph()->NewNode(simplified()->ToBoolean(), input);
+  Node* use_value = UseValue(node);
+  Reduction r = Reduce(node);
   ASSERT_TRUE(r.Changed());
-  EXPECT_THAT(r.replacement(), IsTrueConstant());
+  EXPECT_THAT(use_value->InputAt(1), IsTrueConstant());
 }
 
 }  // namespace constant_folding_reducer_unittest
diff --git a/deps/v8/test/unittests/compiler/graph-unittest.cc b/deps/v8/test/unittests/compiler/graph-unittest.cc
index 0008eadaf9..0d825dc60b 100644
--- a/deps/v8/test/unittests/compiler/graph-unittest.cc
+++ b/deps/v8/test/unittests/compiler/graph-unittest.cc
@@ -66,7 +66,7 @@ Node* GraphTest::NumberConstant(volatile double value) {
 
 Node* GraphTest::HeapConstant(const Handle<HeapObject>& value) {
   Node* node = graph()->NewNode(common()->HeapConstant(value));
-  Type type = Type::NewConstant(broker(), value, zone());
+  Type type = Type::Constant(broker(), value, zone());
   NodeProperties::SetType(node, type);
   return node;
 }
diff --git a/deps/v8/test/unittests/compiler/int64-lowering-unittest.cc b/deps/v8/test/unittests/compiler/int64-lowering-unittest.cc
index 7e927ea078..30e24b0aa4 100644
--- a/deps/v8/test/unittests/compiler/int64-lowering-unittest.cc
+++ b/deps/v8/test/unittests/compiler/int64-lowering-unittest.cc
@@ -1016,10 +1016,8 @@ TEST_F(Int64LoweringTest, WasmBigIntSpecialCaseBigIntToI64) {
           StubCallMode::kCallCodeObject);  // stub call mode
 
   auto lowering_special_case = std::make_unique<Int64LoweringSpecialCase>();
-  lowering_special_case->bigint_to_i64_call_descriptor =
-      bigint_to_i64_call_descriptor;
-  lowering_special_case->bigint_to_i32_pair_call_descriptor =
-      bigint_to_i32_pair_call_descriptor;
+  lowering_special_case->replacements.insert(
+      {bigint_to_i64_call_descriptor, bigint_to_i32_pair_call_descriptor});
 
   Node* call_node =
       graph()->NewNode(common()->Call(bigint_to_i64_call_descriptor), target,
@@ -1064,10 +1062,8 @@ TEST_F(Int64LoweringTest, WasmBigIntSpecialCaseI64ToBigInt) {
           StubCallMode::kCallCodeObject);  // stub call mode
 
   auto lowering_special_case = std::make_unique<Int64LoweringSpecialCase>();
-  lowering_special_case->i64_to_bigint_call_descriptor =
-      i64_to_bigint_call_descriptor;
-  lowering_special_case->i32_pair_to_bigint_call_descriptor =
-      i32_pair_to_bigint_call_descriptor;
+  lowering_special_case->replacements.insert(
+      {i64_to_bigint_call_descriptor, i32_pair_to_bigint_call_descriptor});
 
   Node* call = graph()->NewNode(common()->Call(i64_to_bigint_call_descriptor),
                                 target, i64, start(), start());
diff --git a/deps/v8/test/unittests/compiler/js-typed-lowering-unittest.cc b/deps/v8/test/unittests/compiler/js-typed-lowering-unittest.cc
index eed74f6181..fe5a02e3f2 100644
--- a/deps/v8/test/unittests/compiler/js-typed-lowering-unittest.cc
+++ b/deps/v8/test/unittests/compiler/js-typed-lowering-unittest.cc
@@ -174,8 +174,7 @@ TEST_F(JSTypedLoweringTest, JSStrictEqualWithTheHole) {
     Reduction r = Reduce(
         graph()->NewNode(javascript()->StrictEqual(CompareOperationHint::kAny),
                          lhs, the_hole, context, effect, control));
-    ASSERT_TRUE(r.Changed());
-    EXPECT_THAT(r.replacement(), IsFalseConstant());
+    ASSERT_FALSE(r.Changed());
   }
 }
 
diff --git a/deps/v8/test/unittests/compiler/machine-operator-reducer-unittest.cc b/deps/v8/test/unittests/compiler/machine-operator-reducer-unittest.cc
index bcf0a7101c..c3659032cf 100644
--- a/deps/v8/test/unittests/compiler/machine-operator-reducer-unittest.cc
+++ b/deps/v8/test/unittests/compiler/machine-operator-reducer-unittest.cc
@@ -1058,6 +1058,76 @@ TEST_F(MachineOperatorReducerTest, Word32ShlWithWord32Shr) {
   }
 }
 
+// -----------------------------------------------------------------------------
+// Word32Equal
+
+TEST_F(MachineOperatorReducerTest,
+       Word32EqualWithShiftedMaskedValueAndConstant) {
+  // ((x >> K1) & K2) == K3 => (x & (K2 << K1)) == (K3 << K1)
+  Node* const p0 = Parameter(0);
+  TRACED_FOREACH(uint32_t, mask, kUint32Values) {
+    TRACED_FOREACH(uint32_t, rhs, kUint32Values) {
+      TRACED_FORRANGE(uint32_t, shift_bits, 1, 31) {
+        Node* node = graph()->NewNode(
+            machine()->Word32Equal(),
+            graph()->NewNode(machine()->Word32And(),
+                             graph()->NewNode(machine()->Word32Shr(), p0,
+                                              Uint32Constant(shift_bits)),
+                             Uint32Constant(mask)),
+            Uint32Constant(rhs));
+        Reduction r = Reduce(node);
+        uint32_t new_mask = mask << shift_bits;
+        uint32_t new_rhs = rhs << shift_bits;
+        if (new_mask >> shift_bits == mask && new_rhs >> shift_bits == rhs) {
+          ASSERT_TRUE(r.Changed());
+          // The left-hand side of the equality is now a Word32And operation,
+          // unless the mask is zero in which case the newly-created Word32And
+          // is immediately reduced away.
+          Matcher<Node*> lhs = mask == 0
+                                   ? IsInt32Constant(0)
+                                   : IsWord32And(p0, IsInt32Constant(new_mask));
+          EXPECT_THAT(r.replacement(),
+                      IsWord32Equal(lhs, IsInt32Constant(new_rhs)));
+        } else {
+          ASSERT_FALSE(r.Changed());
+        }
+      }
+    }
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Branch
+
+TEST_F(MachineOperatorReducerTest, BranchWithShiftedMaskedValue) {
+  // Branch condition (x >> K1) & K2 => x & (K2 << K1)
+  Node* const p0 = Parameter(0);
+  TRACED_FOREACH(uint32_t, mask, kUint32Values) {
+    TRACED_FORRANGE(uint32_t, shift_bits, 1, 31) {
+      Node* node = graph()->NewNode(
+          common()->Branch(),
+          graph()->NewNode(machine()->Word32And(),
+                           graph()->NewNode(machine()->Word32Shr(), p0,
+                                            Uint32Constant(shift_bits)),
+                           Uint32Constant(mask)),
+          graph()->start());
+      Reduction r = Reduce(node);
+      uint32_t new_mask = mask << shift_bits;
+      if (new_mask >> shift_bits == mask) {
+        ASSERT_TRUE(r.Changed());
+        // The branch condition is now a Word32And operation, unless the mask is
+        // zero in which case the newly-created Word32And is immediately reduced
+        // away.
+        Matcher<Node*> lhs = mask == 0
+                                 ? IsInt32Constant(0)
+                                 : IsWord32And(p0, IsInt32Constant(new_mask));
+        EXPECT_THAT(r.replacement(), IsBranch(lhs, graph()->start()));
+      } else {
+        ASSERT_FALSE(r.Changed());
+      }
+    }
+  }
+}
 
 // -----------------------------------------------------------------------------
 // Int32Sub
diff --git a/deps/v8/test/unittests/compiler/node-cache-unittest.cc b/deps/v8/test/unittests/compiler/node-cache-unittest.cc
index 10118c3a41..777652db1b 100644
--- a/deps/v8/test/unittests/compiler/node-cache-unittest.cc
+++ b/deps/v8/test/unittests/compiler/node-cache-unittest.cc
@@ -17,13 +17,13 @@ namespace node_cache_unittest {
 using NodeCacheTest = GraphTest;
 
 TEST_F(NodeCacheTest, Int32Constant_back_to_back) {
-  Int32NodeCache cache;
+  Int32NodeCache cache(zone());
 
   for (int i = -2000000000; i < 2000000000; i += 3315177) {
-    Node** pos = cache.Find(zone(), i);
+    Node** pos = cache.Find(i);
     ASSERT_TRUE(pos != nullptr);
     for (int j = 0; j < 3; j++) {
-      Node** npos = cache.Find(zone(), i);
+      Node** npos = cache.Find(i);
       EXPECT_EQ(pos, npos);
     }
   }
@@ -31,38 +31,38 @@ TEST_F(NodeCacheTest, Int32Constant_back_to_back) {
 
 
 TEST_F(NodeCacheTest, Int32Constant_five) {
-  Int32NodeCache cache;
+  Int32NodeCache cache(zone());
   int32_t constants[] = {static_cast<int32_t>(0x80000000), -77, 0, 1, -1};
   Node* nodes[arraysize(constants)];
 
   for (size_t i = 0; i < arraysize(constants); i++) {
     int32_t k = constants[i];
     Node* node = graph()->NewNode(common()->Int32Constant(k));
-    *cache.Find(zone(), k) = nodes[i] = node;
+    *cache.Find(k) = nodes[i] = node;
   }
 
   for (size_t i = 0; i < arraysize(constants); i++) {
     int32_t k = constants[i];
-    EXPECT_EQ(nodes[i], *cache.Find(zone(), k));
+    EXPECT_EQ(nodes[i], *cache.Find(k));
   }
 }
 
 
 TEST_F(NodeCacheTest, Int32Constant_hits) {
-  Int32NodeCache cache;
+  Int32NodeCache cache(zone());
   const int32_t kSize = 1500;
   Node** nodes = zone()->NewArray<Node*>(kSize);
 
   for (int i = 0; i < kSize; i++) {
     int32_t v = i * -55;
     nodes[i] = graph()->NewNode(common()->Int32Constant(v));
-    *cache.Find(zone(), v) = nodes[i];
+    *cache.Find(v) = nodes[i];
   }
 
   int hits = 0;
   for (int i = 0; i < kSize; i++) {
     int32_t v = i * -55;
-    Node** pos = cache.Find(zone(), v);
+    Node** pos = cache.Find(v);
     if (*pos != nullptr) {
       EXPECT_EQ(nodes[i], *pos);
       hits++;
@@ -73,13 +73,13 @@ TEST_F(NodeCacheTest, Int32Constant_hits) {
 
 
 TEST_F(NodeCacheTest, Int64Constant_back_to_back) {
-  Int64NodeCache cache;
+  Int64NodeCache cache(zone());
 
   for (int64_t i = -2000000000; i < 2000000000; i += 3315177) {
-    Node** pos = cache.Find(zone(), i);
+    Node** pos = cache.Find(i);
     ASSERT_TRUE(pos != nullptr);
     for (int j = 0; j < 3; j++) {
-      Node** npos = cache.Find(zone(), i);
+      Node** npos = cache.Find(i);
       EXPECT_EQ(pos, npos);
     }
   }
@@ -87,20 +87,20 @@ TEST_F(NodeCacheTest, Int64Constant_back_to_back) {
 
 
 TEST_F(NodeCacheTest, Int64Constant_hits) {
-  Int64NodeCache cache;
+  Int64NodeCache cache(zone());
   const int32_t kSize = 1500;
   Node** nodes = zone()->NewArray<Node*>(kSize);
 
   for (int i = 0; i < kSize; i++) {
     int64_t v = static_cast<int64_t>(i) * static_cast<int64_t>(5003001);
     nodes[i] = graph()->NewNode(common()->Int32Constant(i));
-    *cache.Find(zone(), v) = nodes[i];
+    *cache.Find(v) = nodes[i];
   }
 
   int hits = 0;
   for (int i = 0; i < kSize; i++) {
     int64_t v = static_cast<int64_t>(i) * static_cast<int64_t>(5003001);
-    Node** pos = cache.Find(zone(), v);
+    Node** pos = cache.Find(v);
     if (*pos != nullptr) {
       EXPECT_EQ(nodes[i], *pos);
       hits++;
@@ -111,13 +111,13 @@ TEST_F(NodeCacheTest, Int64Constant_hits) {
 
 
 TEST_F(NodeCacheTest, GetCachedNodes_int32) {
-  Int32NodeCache cache;
+  Int32NodeCache cache(zone());
   int32_t constants[] = {0, 311, 12,  13,  14,  555, -555, -44, -33, -22, -11,
                          0, 311, 311, 412, 412, 11,  11,   -33, -33, -22, -11};
 
   for (size_t i = 0; i < arraysize(constants); i++) {
     int32_t k = constants[i];
-    Node** pos = cache.Find(zone(), k);
+    Node** pos = cache.Find(k);
     if (*pos != nullptr) {
       ZoneVector<Node*> nodes(zone());
       cache.GetCachedNodes(&nodes);
@@ -134,13 +134,13 @@ TEST_F(NodeCacheTest, GetCachedNodes_int32) {
 
 
 TEST_F(NodeCacheTest, GetCachedNodes_int64) {
-  Int64NodeCache cache;
+  Int64NodeCache cache(zone());
   int64_t constants[] = {0, 311, 12,  13,  14,  555, -555, -44, -33, -22, -11,
                          0, 311, 311, 412, 412, 11,  11,   -33, -33, -22, -11};
 
   for (size_t i = 0; i < arraysize(constants); i++) {
     int64_t k = constants[i];
-    Node** pos = cache.Find(zone(), k);
+    Node** pos = cache.Find(k);
     if (*pos != nullptr) {
       ZoneVector<Node*> nodes(zone());
       cache.GetCachedNodes(&nodes);
diff --git a/deps/v8/test/unittests/compiler/redundancy-elimination-unittest.cc b/deps/v8/test/unittests/compiler/redundancy-elimination-unittest.cc
index 62135dddce..9dda52ed8e 100644
--- a/deps/v8/test/unittests/compiler/redundancy-elimination-unittest.cc
+++ b/deps/v8/test/unittests/compiler/redundancy-elimination-unittest.cc
@@ -754,16 +754,18 @@ TEST_F(RedundancyEliminationTest, CheckedUint64Bounds) {
       Node* effect = graph()->start();
       Node* control = graph()->start();
 
-      Node* check1 = effect =
-          graph()->NewNode(simplified()->CheckedUint64Bounds(feedback1), index,
-                           length, effect, control);
+      Node* check1 = effect = graph()->NewNode(
+          simplified()->CheckedUint64Bounds(
+              feedback1, CheckBoundsParameters::kDeoptOnOutOfBounds),
+          index, length, effect, control);
       Reduction r1 = Reduce(check1);
       ASSERT_TRUE(r1.Changed());
       EXPECT_EQ(r1.replacement(), check1);
 
-      Node* check2 = effect =
-          graph()->NewNode(simplified()->CheckedUint64Bounds(feedback2), index,
-                           length, effect, control);
+      Node* check2 = effect = graph()->NewNode(
+          simplified()->CheckedUint64Bounds(
+              feedback2, CheckBoundsParameters::kDeoptOnOutOfBounds),
+          index, length, effect, control);
       Reduction r2 = Reduce(check2);
       ASSERT_TRUE(r2.Changed());
       EXPECT_EQ(r2.replacement(), check1);
diff --git a/deps/v8/test/unittests/compiler/state-values-utils-unittest.cc b/deps/v8/test/unittests/compiler/state-values-utils-unittest.cc
index e6ba7696c5..c24b2f2d97 100644
--- a/deps/v8/test/unittests/compiler/state-values-utils-unittest.cc
+++ b/deps/v8/test/unittests/compiler/state-values-utils-unittest.cc
@@ -153,11 +153,13 @@ TEST_F(StateValuesIteratorTest, TreeFromVectorWithLiveness) {
 
     // Check the tree contents with vector.
     int i = 0;
-    for (StateValuesAccess::TypedNode node : StateValuesAccess(values_node)) {
+    for (StateValuesAccess::iterator it =
+             StateValuesAccess(values_node).begin();
+         !it.done(); ++it) {
       if (liveness.Contains(i)) {
-        EXPECT_THAT(node.node, IsInt32Constant(i));
+        EXPECT_THAT(it.node(), IsInt32Constant(i));
       } else {
-        EXPECT_EQ(node.node, nullptr);
+        EXPECT_EQ(it.node(), nullptr);
       }
       i++;
     }
diff --git a/deps/v8/test/unittests/compiler/typer-unittest.cc b/deps/v8/test/unittests/compiler/typer-unittest.cc
index bfb65e7c5f..8ecee3f8a1 100644
--- a/deps/v8/test/unittests/compiler/typer-unittest.cc
+++ b/deps/v8/test/unittests/compiler/typer-unittest.cc
@@ -175,7 +175,7 @@ class TyperTest : public TypedGraphTest {
           for (int x1 = lmin; x1 < lmin + width; x1++) {
             for (int x2 = rmin; x2 < rmin + width; x2++) {
               double result_value = opfun(x1, x2);
-              Type result_type = Type::NewConstant(
+              Type result_type = Type::Constant(
                   &broker_, isolate()->factory()->NewNumber(result_value),
                   zone());
               EXPECT_TRUE(result_type.Is(expected_type));
@@ -197,7 +197,7 @@ class TyperTest : public TypedGraphTest {
         double x1 = RandomInt(r1.AsRange());
         double x2 = RandomInt(r2.AsRange());
         double result_value = opfun(x1, x2);
-        Type result_type = Type::NewConstant(
+        Type result_type = Type::Constant(
             &broker_, isolate()->factory()->NewNumber(result_value), zone());
         EXPECT_TRUE(result_type.Is(expected_type));
       }
@@ -205,13 +205,13 @@ class TyperTest : public TypedGraphTest {
     // Test extreme cases.
     double x1 = +1e-308;
     double x2 = -1e-308;
-    Type r1 = Type::NewConstant(&broker_, isolate()->factory()->NewNumber(x1),
-                                zone());
-    Type r2 = Type::NewConstant(&broker_, isolate()->factory()->NewNumber(x2),
-                                zone());
+    Type r1 =
+        Type::Constant(&broker_, isolate()->factory()->NewNumber(x1), zone());
+    Type r2 =
+        Type::Constant(&broker_, isolate()->factory()->NewNumber(x2), zone());
     Type expected_type = TypeBinaryOp(op, r1, r2);
     double result_value = opfun(x1, x2);
-    Type result_type = Type::NewConstant(
+    Type result_type = Type::Constant(
         &broker_, isolate()->factory()->NewNumber(result_value), zone());
     EXPECT_TRUE(result_type.Is(expected_type));
   }
@@ -226,11 +226,11 @@ class TyperTest : public TypedGraphTest {
         double x1 = RandomInt(r1.AsRange());
         double x2 = RandomInt(r2.AsRange());
         bool result_value = opfun(x1, x2);
-        Type result_type = Type::NewConstant(
-            &broker_,
-            result_value ? isolate()->factory()->true_value()
-                         : isolate()->factory()->false_value(),
-            zone());
+        Type result_type =
+            Type::Constant(&broker_,
+                           result_value ? isolate()->factory()->true_value()
+                                        : isolate()->factory()->false_value(),
+                           zone());
         EXPECT_TRUE(result_type.Is(expected_type));
       }
     }
@@ -246,7 +246,7 @@ class TyperTest : public TypedGraphTest {
         int32_t x1 = static_cast<int32_t>(RandomInt(r1.AsRange()));
         int32_t x2 = static_cast<int32_t>(RandomInt(r2.AsRange()));
         double result_value = opfun(x1, x2);
-        Type result_type = Type::NewConstant(
+        Type result_type = Type::Constant(
             &broker_, isolate()->factory()->NewNumber(result_value), zone());
         EXPECT_TRUE(result_type.Is(expected_type));
       }
@@ -585,6 +585,96 @@ SIMPLIFIED_NUMBER_BINOP_LIST(TEST_MONOTONICITY)
 SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(TEST_MONOTONICITY)
 #undef TEST_MONOTONICITY
 
+TEST_F(TyperTest, Manual_Operation_NumberMax) {
+  BinaryTyper t = [&](Type type1, Type type2) {
+    return operation_typer_.NumberMax(type1, type2);
+  };
+
+  Type zero = Type::Constant(0, zone());
+  Type zero_or_minuszero = Type::Union(zero, Type::MinusZero(), zone());
+  Type dot_five = Type::Constant(0.5, zone());
+
+  Type a = t(Type::MinusZero(), Type::MinusZero());
+  CHECK(Type::MinusZero().Is(a));
+
+  Type b = t(Type::MinusZero(), zero_or_minuszero);
+  CHECK(Type::MinusZero().Is(b));
+  CHECK(zero.Is(b));
+  CHECK(a.Is(b));
+
+  Type c = t(zero_or_minuszero, Type::MinusZero());
+  CHECK(Type::MinusZero().Is(c));
+  CHECK(zero.Is(c));
+  CHECK(a.Is(c));
+
+  Type d = t(zero_or_minuszero, zero_or_minuszero);
+  CHECK(Type::MinusZero().Is(d));
+  CHECK(zero.Is(d));
+  CHECK(b.Is(d));
+  CHECK(c.Is(d));
+
+  Type e =
+      t(Type::MinusZero(), Type::Union(Type::MinusZero(), dot_five, zone()));
+  CHECK(Type::MinusZero().Is(e));
+  CHECK(dot_five.Is(e));
+  CHECK(a.Is(e));
+
+  Type f = t(Type::MinusZero(), zero);
+  CHECK(zero.Is(f));
+  CHECK(f.Is(b));
+
+  Type g = t(zero, Type::MinusZero());
+  CHECK(zero.Is(g));
+  CHECK(g.Is(c));
+}
+
+TEST_F(TyperTest, Manual_Operation_NumberMin) {
+  BinaryTyper t = [&](Type type1, Type type2) {
+    return operation_typer_.NumberMin(type1, type2);
+  };
+
+  Type zero = Type::Constant(0, zone());
+  Type zero_or_minuszero = Type::Union(zero, Type::MinusZero(), zone());
+  Type one = Type::Constant(1, zone());
+  Type minus_dot_five = Type::Constant(-0.5, zone());
+
+  Type a = t(Type::MinusZero(), Type::MinusZero());
+  CHECK(Type::MinusZero().Is(a));
+
+  Type b = t(Type::MinusZero(), zero_or_minuszero);
+  CHECK(Type::MinusZero().Is(b));
+  CHECK(zero.Is(b));
+  CHECK(a.Is(b));
+
+  Type c = t(zero_or_minuszero, Type::MinusZero());
+  CHECK(Type::MinusZero().Is(c));
+  CHECK(zero.Is(c));
+  CHECK(a.Is(c));
+
+  Type d = t(zero_or_minuszero, zero_or_minuszero);
+  CHECK(Type::MinusZero().Is(d));
+  CHECK(zero.Is(d));
+  CHECK(b.Is(d));
+  CHECK(c.Is(d));
+
+  Type e = t(Type::MinusZero(),
+             Type::Union(Type::MinusZero(), minus_dot_five, zone()));
+  CHECK(Type::MinusZero().Is(e));
+  CHECK(minus_dot_five.Is(e));
+  CHECK(a.Is(e));
+
+  Type f = t(Type::MinusZero(), zero);
+  CHECK(Type::MinusZero().Is(f));
+  CHECK(f.Is(b));
+
+  Type g = t(zero, Type::MinusZero());
+  CHECK(Type::MinusZero().Is(g));
+  CHECK(g.Is(c));
+
+  Type h = t(one, Type::MinusZero());
+  CHECK(Type::MinusZero().Is(h));
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/unittests/execution/microtask-queue-unittest.cc b/deps/v8/test/unittests/execution/microtask-queue-unittest.cc
index 6cb9df0895..3b59b7cf35 100644
--- a/deps/v8/test/unittests/execution/microtask-queue-unittest.cc
+++ b/deps/v8/test/unittests/execution/microtask-queue-unittest.cc
@@ -30,10 +30,10 @@ void RunStdFunction(void* data) {
 }
 
 template <typename TMixin>
-class WithFinalizationGroupMixin : public TMixin {
+class WithFinalizationRegistryMixin : public TMixin {
  public:
-  WithFinalizationGroupMixin() = default;
-  ~WithFinalizationGroupMixin() override = default;
+  WithFinalizationRegistryMixin() = default;
+  ~WithFinalizationRegistryMixin() override = default;
 
   static void SetUpTestCase() {
     CHECK_NULL(save_flags_);
@@ -54,21 +54,29 @@ class WithFinalizationGroupMixin : public TMixin {
  private:
   static SaveFlags* save_flags_;
 
-  DISALLOW_COPY_AND_ASSIGN(WithFinalizationGroupMixin);
+  DISALLOW_COPY_AND_ASSIGN(WithFinalizationRegistryMixin);
 };
 
 template <typename TMixin>
-SaveFlags* WithFinalizationGroupMixin<TMixin>::save_flags_ = nullptr;
-
-using TestWithNativeContextAndFinalizationGroup =  //
-    WithInternalIsolateMixin<                      //
-        WithContextMixin<                          //
-            WithFinalizationGroupMixin<            //
-                WithIsolateScopeMixin<             //
-                    WithSharedIsolateMixin<        //
+SaveFlags* WithFinalizationRegistryMixin<TMixin>::save_flags_ = nullptr;
+
+using TestWithNativeContextAndFinalizationRegistry =  //
+    WithInternalIsolateMixin<                         //
+        WithContextMixin<                             //
+            WithFinalizationRegistryMixin<            //
+                WithIsolateScopeMixin<                //
+                    WithSharedIsolateMixin<           //
                         ::testing::Test>>>>>;
 
-class MicrotaskQueueTest : public TestWithNativeContextAndFinalizationGroup {
+namespace {
+
+void DummyPromiseHook(PromiseHookType type, Local<Promise> promise,
+                      Local<Value> parent) {}
+
+}  // namespace
+
+class MicrotaskQueueTest : public TestWithNativeContextAndFinalizationRegistry,
+                           public ::testing::WithParamInterface<bool> {
  public:
   template <typename F>
   Handle<Microtask> NewMicrotask(F&& f) {
@@ -82,6 +90,12 @@ class MicrotaskQueueTest : public TestWithNativeContextAndFinalizationGroup {
   void SetUp() override {
     microtask_queue_ = MicrotaskQueue::New(isolate());
     native_context()->set_microtask_queue(microtask_queue());
+
+    if (GetParam()) {
+      // Use a PromiseHook to switch the implementation to ResolvePromise
+      // runtime, instead of ResolvePromise builtin.
+      v8_isolate()->SetPromiseHook(&DummyPromiseHook);
+    }
   }
 
   void TearDown() override {
@@ -126,7 +140,7 @@ class RecordingVisitor : public RootVisitor {
 };
 
 // Sanity check. Ensure a microtask is stored in a queue and run.
-TEST_F(MicrotaskQueueTest, EnqueueAndRun) {
+TEST_P(MicrotaskQueueTest, EnqueueAndRun) {
   bool ran = false;
   EXPECT_EQ(0, microtask_queue()->capacity());
   EXPECT_EQ(0, microtask_queue()->size());
@@ -142,7 +156,7 @@ TEST_F(MicrotaskQueueTest, EnqueueAndRun) {
 }
 
 // Check for a buffer growth.
-TEST_F(MicrotaskQueueTest, BufferGrowth) {
+TEST_P(MicrotaskQueueTest, BufferGrowth) {
   int count = 0;
 
   // Enqueue and flush the queue first to have non-zero |start_|.
@@ -176,7 +190,7 @@ TEST_F(MicrotaskQueueTest, BufferGrowth) {
 }
 
 // MicrotaskQueue instances form a doubly linked list.
-TEST_F(MicrotaskQueueTest, InstanceChain) {
+TEST_P(MicrotaskQueueTest, InstanceChain) {
   ClearTestMicrotaskQueue();
 
   MicrotaskQueue* default_mtq = isolate()->default_microtask_queue();
@@ -207,7 +221,7 @@ TEST_F(MicrotaskQueueTest, InstanceChain) {
 
 // Pending Microtasks in MicrotaskQueues are strong roots. Ensure they are
 // visited exactly once.
-TEST_F(MicrotaskQueueTest, VisitRoot) {
+TEST_P(MicrotaskQueueTest, VisitRoot) {
   // Ensure that the ring buffer has separate in-use region.
   for (int i = 0; i < MicrotaskQueue::kMinimumCapacity / 2 + 1; ++i) {
     microtask_queue()->EnqueueMicrotask(*NewMicrotask([] {}));
@@ -233,7 +247,7 @@ TEST_F(MicrotaskQueueTest, VisitRoot) {
   EXPECT_EQ(expected, actual);
 }
 
-TEST_F(MicrotaskQueueTest, PromiseHandlerContext) {
+TEST_P(MicrotaskQueueTest, PromiseHandlerContext) {
   Local<v8::Context> v8_context2 = v8::Context::New(v8_isolate());
   Local<v8::Context> v8_context3 = v8::Context::New(v8_isolate());
   Local<v8::Context> v8_context4 = v8::Context::New(v8_isolate());
@@ -327,7 +341,7 @@ TEST_F(MicrotaskQueueTest, PromiseHandlerContext) {
   v8_context2->DetachGlobal();
 }
 
-TEST_F(MicrotaskQueueTest, DetachGlobal_Enqueue) {
+TEST_P(MicrotaskQueueTest, DetachGlobal_Enqueue) {
   EXPECT_EQ(0, microtask_queue()->size());
 
   // Detach MicrotaskQueue from the current context.
@@ -339,7 +353,7 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_Enqueue) {
   EXPECT_EQ(0, microtask_queue()->size());
 }
 
-TEST_F(MicrotaskQueueTest, DetachGlobal_Run) {
+TEST_P(MicrotaskQueueTest, DetachGlobal_Run) {
   EXPECT_EQ(0, microtask_queue()->size());
 
   // Enqueue microtasks to the current context.
@@ -377,18 +391,7 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_Run) {
   }
 }
 
-namespace {
-
-void DummyPromiseHook(PromiseHookType type, Local<Promise> promise,
-                      Local<Value> parent) {}
-
-}  // namespace
-
-TEST_F(MicrotaskQueueTest, DetachGlobal_PromiseResolveThenableJobTask) {
-  // Use a PromiseHook to switch the implementation to ResolvePromise runtime,
-  // instead of ResolvePromise builtin.
-  v8_isolate()->SetPromiseHook(&DummyPromiseHook);
-
+TEST_P(MicrotaskQueueTest, DetachGlobal_PromiseResolveThenableJobTask) {
   RunJS(
       "var resolve;"
       "var promise = new Promise(r => { resolve = r; });"
@@ -410,7 +413,71 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_PromiseResolveThenableJobTask) {
   EXPECT_EQ(0, microtask_queue()->size());
 }
 
-TEST_F(MicrotaskQueueTest, DetachGlobal_HandlerContext) {
+TEST_P(MicrotaskQueueTest, DetachGlobal_ResolveThenableForeignThen) {
+  Handle<JSArray> result = RunJS<JSArray>(
+      "let result = [false];"
+      "result");
+  Handle<JSFunction> then = RunJS<JSFunction>("() => { result[0] = true; }");
+
+  Handle<JSPromise> stale_promise;
+
+  {
+    // Create a context with its own microtask queue.
+    std::unique_ptr<MicrotaskQueue> sub_microtask_queue =
+        MicrotaskQueue::New(isolate());
+    Local<v8::Context> sub_context = v8::Context::New(
+        v8_isolate(),
+        /* extensions= */ nullptr,
+        /* global_template= */ MaybeLocal<ObjectTemplate>(),
+        /* global_object= */ MaybeLocal<Value>(),
+        /* internal_fields_deserializer= */ DeserializeInternalFieldsCallback(),
+        sub_microtask_queue.get());
+
+    {
+      v8::Context::Scope scope(sub_context);
+      CHECK(sub_context->Global()
+                ->Set(sub_context, NewString("then"),
+                      Utils::ToLocal(Handle<JSReceiver>::cast(then)))
+                .FromJust());
+
+      ASSERT_EQ(0, microtask_queue()->size());
+      ASSERT_EQ(0, sub_microtask_queue->size());
+      ASSERT_TRUE(Object::GetElement(isolate(), result, 0)
+                      .ToHandleChecked()
+                      ->IsFalse());
+
+      // With a regular thenable, a microtask is queued on the sub-context.
+      RunJS<JSPromise>("Promise.resolve({ then: cb => cb(1) })");
+      EXPECT_EQ(0, microtask_queue()->size());
+      EXPECT_EQ(1, sub_microtask_queue->size());
+      EXPECT_TRUE(Object::GetElement(isolate(), result, 0)
+                      .ToHandleChecked()
+                      ->IsFalse());
+
+      // But when the `then` method comes from another context, a microtask is
+      // instead queued on the main context.
+      stale_promise = RunJS<JSPromise>("Promise.resolve({ then })");
+      EXPECT_EQ(1, microtask_queue()->size());
+      EXPECT_EQ(1, sub_microtask_queue->size());
+      EXPECT_TRUE(Object::GetElement(isolate(), result, 0)
+                      .ToHandleChecked()
+                      ->IsFalse());
+    }
+
+    sub_context->DetachGlobal();
+  }
+
+  EXPECT_EQ(1, microtask_queue()->size());
+  EXPECT_TRUE(
+      Object::GetElement(isolate(), result, 0).ToHandleChecked()->IsFalse());
+
+  EXPECT_EQ(1, microtask_queue()->RunMicrotasks(isolate()));
+  EXPECT_EQ(0, microtask_queue()->size());
+  EXPECT_TRUE(
+      Object::GetElement(isolate(), result, 0).ToHandleChecked()->IsTrue());
+}
+
+TEST_P(MicrotaskQueueTest, DetachGlobal_HandlerContext) {
   // EnqueueMicrotask should use the context associated to the handler instead
   // of the current context. E.g.
   //   // At Context A.
@@ -489,7 +556,7 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_HandlerContext) {
           .FromJust());
 }
 
-TEST_F(MicrotaskQueueTest, DetachGlobal_Chain) {
+TEST_P(MicrotaskQueueTest, DetachGlobal_Chain) {
   Handle<JSPromise> stale_rejected_promise;
 
   Local<v8::Context> sub_context = v8::Context::New(v8_isolate());
@@ -516,7 +583,7 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_Chain) {
       Object::GetElement(isolate(), result, 0).ToHandleChecked()->IsTrue());
 }
 
-TEST_F(MicrotaskQueueTest, DetachGlobal_InactiveHandler) {
+TEST_P(MicrotaskQueueTest, DetachGlobal_InactiveHandler) {
   Local<v8::Context> sub_context = v8::Context::New(v8_isolate());
   Utils::OpenHandle(*sub_context)
       ->native_context()
@@ -558,7 +625,7 @@ TEST_F(MicrotaskQueueTest, DetachGlobal_InactiveHandler) {
       Object::GetElement(isolate(), result, 1).ToHandleChecked()->IsFalse());
 }
 
-TEST_F(MicrotaskQueueTest, MicrotasksScope) {
+TEST_P(MicrotaskQueueTest, MicrotasksScope) {
   ASSERT_NE(isolate()->default_microtask_queue(), microtask_queue());
   microtask_queue()->set_microtasks_policy(MicrotasksPolicy::kScoped);
 
@@ -574,5 +641,11 @@ TEST_F(MicrotaskQueueTest, MicrotasksScope) {
   EXPECT_TRUE(ran);
 }
 
+INSTANTIATE_TEST_SUITE_P(
+    , MicrotaskQueueTest, ::testing::Values(false, true),
+    [](const ::testing::TestParamInfo<MicrotaskQueueTest::ParamType>& info) {
+      return info.param ? "runtime" : "builtin";
+    });
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/unittests/heap/cppgc/allocation_unittest.cc b/deps/v8/test/unittests/heap/cppgc/allocation_unittest.cc
new file mode 100644
index 0000000000..3a02ae1721
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/allocation_unittest.cc
@@ -0,0 +1,42 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/allocation.h"
+
+#include <memory>
+
+#include "src/heap/cppgc/heap.h"
+#include "test/unittests/heap/cppgc/tests.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+
+TEST(GCBasicHeapTest, CreateAndDestroyHeap) {
+  std::unique_ptr<Heap> heap{Heap::Create()};
+}
+
+namespace {
+
+class Foo : public GarbageCollected<Foo> {
+ public:
+  static size_t destructor_callcount;
+
+  Foo() { destructor_callcount = 0; }
+  ~Foo() { destructor_callcount++; }
+};
+
+size_t Foo::destructor_callcount;
+
+class GCAllocationTest : public testing::TestWithHeap {};
+
+}  // namespace
+
+TEST_F(GCAllocationTest, MakeGarbageCollectedAndReclaim) {
+  MakeGarbageCollected<Foo>(GetHeap());
+  EXPECT_EQ(0u, Foo::destructor_callcount);
+  internal::Heap::From(GetHeap())->CollectGarbage();
+  EXPECT_EQ(1u, Foo::destructor_callcount);
+}
+
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/finalizer-trait_unittest.cc b/deps/v8/test/unittests/heap/cppgc/finalizer-trait_unittest.cc
new file mode 100644
index 0000000000..91a255e727
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/finalizer-trait_unittest.cc
@@ -0,0 +1,118 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/finalizer-trait.h"
+#include <type_traits>
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+namespace internal {
+
+namespace {
+
+// Trivially destructible types.
+class TypeWithoutDestructor final {};
+class TypeWithPrimitive final {
+ public:
+  int foo = 0;
+};
+
+class InvokeCounter {
+ public:
+  static size_t kCallcount;
+  static void Reset() { kCallcount = 0; }
+  static void Invoke() { kCallcount++; }
+};
+
+size_t InvokeCounter::kCallcount = 0;
+
+// Regular C++ use cases.
+
+class TypeWithDestructor final : public InvokeCounter {
+ public:
+  ~TypeWithDestructor() { Invoke(); }
+};
+
+class TypeWithVirtualDestructorBase {
+ public:
+  virtual ~TypeWithVirtualDestructorBase() = default;
+};
+
+class TypeWithVirtualDestructorChild final
+    : public TypeWithVirtualDestructorBase,
+      public InvokeCounter {
+ public:
+  ~TypeWithVirtualDestructorChild() final { Invoke(); }
+};
+
+// Manual dispatch to avoid vtables.
+
+class TypeWithCustomFinalizationMethod final : public InvokeCounter {
+ public:
+  void FinalizeGarbageCollectedObject() { Invoke(); }
+};
+
+class TypeWithCustomFinalizationMethodAtBase {
+ public:
+  void FinalizeGarbageCollectedObject();
+};
+
+class TypeWithCustomFinalizationMethodAtBaseChild
+    : public TypeWithCustomFinalizationMethodAtBase,
+      public InvokeCounter {
+ public:
+  ~TypeWithCustomFinalizationMethodAtBaseChild() { Invoke(); }
+};
+
+void TypeWithCustomFinalizationMethodAtBase::FinalizeGarbageCollectedObject() {
+  // The test knows that base is only inherited by a single child. In practice
+  // users can maintain a map of valid types in already existing storage.
+  static_cast<TypeWithCustomFinalizationMethodAtBaseChild*>(this)
+      ->~TypeWithCustomFinalizationMethodAtBaseChild();
+}
+
+template <typename Type>
+void ExpectFinalizerIsInvoked(Type* object) {
+  InvokeCounter::Reset();
+  EXPECT_NE(nullptr, FinalizerTrait<Type>::kCallback);
+  FinalizerTrait<Type>::kCallback(object);
+  EXPECT_EQ(1u, InvokeCounter::kCallcount);
+  operator delete(object);
+}
+
+}  // namespace
+
+TEST(FinalizerTrait, TypeWithoutDestructorHasNoFinalizer) {
+  static_assert(std::is_trivially_destructible<TypeWithoutDestructor>::value,
+                "trivially destructible");
+  EXPECT_EQ(nullptr, FinalizerTrait<TypeWithoutDestructor>::kCallback);
+}
+
+TEST(FinalizerTrait, TypeWithPrimitiveHasNoFinalizer) {
+  static_assert(std::is_trivially_destructible<TypeWithPrimitive>::value,
+                "trivially destructible");
+  EXPECT_EQ(nullptr, FinalizerTrait<TypeWithPrimitive>::kCallback);
+}
+
+TEST(FinalizerTrait, FinalizerForTypeWithDestructor) {
+  ExpectFinalizerIsInvoked(new TypeWithDestructor());
+}
+
+TEST(FinalizerTrait, FinalizerForTypeWithVirtualBaseDtor) {
+  TypeWithVirtualDestructorBase* base = new TypeWithVirtualDestructorChild();
+  ExpectFinalizerIsInvoked(base);
+}
+
+TEST(FinalizerTrait, FinalizerForCustomFinalizationMethod) {
+  ExpectFinalizerIsInvoked(new TypeWithCustomFinalizationMethod());
+}
+
+TEST(FinalizerTrait, FinalizerForCustomFinalizationMethodInBase) {
+  TypeWithCustomFinalizationMethodAtBase* base =
+      new TypeWithCustomFinalizationMethodAtBaseChild();
+  ExpectFinalizerIsInvoked(base);
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/garbage-collected_unittest.cc b/deps/v8/test/unittests/heap/cppgc/garbage-collected_unittest.cc
new file mode 100644
index 0000000000..5098bdf48e
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/garbage-collected_unittest.cc
@@ -0,0 +1,26 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/garbage-collected.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+namespace internal {
+
+namespace {
+
+class GCed : public GarbageCollected<GCed> {};
+class NotGCed {};
+
+}  // namespace
+
+TEST(GarbageCollectedTest, GarbageCollectedTrait) {
+  EXPECT_FALSE(IsGarbageCollectedType<int>::value);
+  EXPECT_FALSE(IsGarbageCollectedType<NotGCed>::value);
+  EXPECT_TRUE(IsGarbageCollectedType<GCed>::value);
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/gc-info_unittest.cc b/deps/v8/test/unittests/heap/cppgc/gc-info_unittest.cc
new file mode 100644
index 0000000000..e7bfb5a7fe
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/gc-info_unittest.cc
@@ -0,0 +1,153 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "include/cppgc/gc-info.h"
+
+#include "include/cppgc/platform.h"
+#include "src/base/page-allocator.h"
+#include "src/base/platform/platform.h"
+#include "src/heap/cppgc/gc-info-table.h"
+#include "test/unittests/heap/cppgc/tests.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+namespace internal {
+
+TEST(GCInfoTableTest, InitialEmpty) {
+  v8::base::PageAllocator page_allocator;
+  GCInfoTable table(&page_allocator);
+  EXPECT_EQ(GCInfoTable::kMinIndex, table.NumberOfGCInfosForTesting());
+}
+
+TEST(GCInfoTableTest, ResizeToMaxIndex) {
+  v8::base::PageAllocator page_allocator;
+  GCInfoTable table(&page_allocator);
+  GCInfo info = {nullptr, false};
+  for (GCInfoIndex i = GCInfoTable::kMinIndex; i < GCInfoTable::kMaxIndex;
+       i++) {
+    GCInfoIndex index = table.RegisterNewGCInfo(info);
+    EXPECT_EQ(i, index);
+  }
+}
+
+TEST(GCInfoTableDeathTest, MoreThanMaxIndexInfos) {
+  v8::base::PageAllocator page_allocator;
+  GCInfoTable table(&page_allocator);
+  GCInfo info = {nullptr, false};
+  // Create GCInfoTable::kMaxIndex entries.
+  for (GCInfoIndex i = GCInfoTable::kMinIndex; i < GCInfoTable::kMaxIndex;
+       i++) {
+    table.RegisterNewGCInfo(info);
+  }
+  EXPECT_DEATH_IF_SUPPORTED(table.RegisterNewGCInfo(info), "");
+}
+
+TEST(GCInfoTableDeathTest, OldTableAreaIsReadOnly) {
+  v8::base::PageAllocator page_allocator;
+  GCInfoTable table(&page_allocator);
+  GCInfo info = {nullptr, false};
+  // Use up all slots until limit.
+  GCInfoIndex limit = table.LimitForTesting();
+  // Bail out if initial limit is already the maximum because of large committed
+  // pages. In this case, nothing can be comitted as read-only.
+  if (limit == GCInfoTable::kMaxIndex) {
+    return;
+  }
+  for (GCInfoIndex i = GCInfoTable::kMinIndex; i < limit; i++) {
+    table.RegisterNewGCInfo(info);
+  }
+  EXPECT_EQ(limit, table.LimitForTesting());
+  table.RegisterNewGCInfo(info);
+  EXPECT_NE(limit, table.LimitForTesting());
+  // Old area is now read-only.
+  auto& first_slot = table.TableSlotForTesting(GCInfoTable::kMinIndex);
+  EXPECT_DEATH_IF_SUPPORTED(first_slot.finalize = nullptr, "");
+}
+
+namespace {
+
+class ThreadRegisteringGCInfoObjects final : public v8::base::Thread {
+ public:
+  ThreadRegisteringGCInfoObjects(GCInfoTable* table,
+                                 GCInfoIndex num_registrations)
+      : v8::base::Thread(Options("Thread registering GCInfo objects.")),
+        table_(table),
+        num_registrations_(num_registrations) {}
+
+  void Run() final {
+    GCInfo info = {nullptr, false};
+    for (GCInfoIndex i = 0; i < num_registrations_; i++) {
+      table_->RegisterNewGCInfo(info);
+    }
+  }
+
+ private:
+  GCInfoTable* table_;
+  GCInfoIndex num_registrations_;
+};
+
+}  // namespace
+
+TEST(GCInfoTableTest, MultiThreadedResizeToMaxIndex) {
+  constexpr size_t num_threads = 4;
+  constexpr size_t main_thread_initialized = 2;
+  constexpr size_t gc_infos_to_register =
+      (GCInfoTable::kMaxIndex - 1) -
+      (GCInfoTable::kMinIndex + main_thread_initialized);
+  static_assert(gc_infos_to_register % num_threads == 0,
+                "must sum up to kMaxIndex");
+  constexpr size_t gc_infos_per_thread = gc_infos_to_register / num_threads;
+
+  v8::base::PageAllocator page_allocator;
+  GCInfoTable table(&page_allocator);
+  GCInfo info = {nullptr, false};
+  for (size_t i = 0; i < main_thread_initialized; i++) {
+    table.RegisterNewGCInfo(info);
+  }
+
+  v8::base::Thread* threads[num_threads];
+  for (size_t i = 0; i < num_threads; i++) {
+    threads[i] =
+        new ThreadRegisteringGCInfoObjects(&table, gc_infos_per_thread);
+  }
+  for (size_t i = 0; i < num_threads; i++) {
+    CHECK(threads[i]->Start());
+  }
+  for (size_t i = 0; i < num_threads; i++) {
+    threads[i]->Join();
+    delete threads[i];
+  }
+}
+
+// Tests using the global table and GCInfoTrait.
+
+namespace {
+
+class GCInfoTraitTest : public testing::TestWithPlatform {};
+
+class BasicType final {};
+class OtherBasicType final {};
+
+}  // namespace
+
+TEST_F(GCInfoTraitTest, IndexInBounds) {
+  const GCInfoIndex index = GCInfoTrait<BasicType>::Index();
+  EXPECT_GT(GCInfoTable::kMaxIndex, index);
+  EXPECT_LE(GCInfoTable::kMinIndex, index);
+}
+
+TEST_F(GCInfoTraitTest, TraitReturnsSameIndexForSameType) {
+  const GCInfoIndex index1 = GCInfoTrait<BasicType>::Index();
+  const GCInfoIndex index2 = GCInfoTrait<BasicType>::Index();
+  EXPECT_EQ(index1, index2);
+}
+
+TEST_F(GCInfoTraitTest, TraitReturnsDifferentIndexForDifferentTypes) {
+  const GCInfoIndex index1 = GCInfoTrait<BasicType>::Index();
+  const GCInfoIndex index2 = GCInfoTrait<OtherBasicType>::Index();
+  EXPECT_NE(index1, index2);
+}
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/heap-object-header_unittest.cc b/deps/v8/test/unittests/heap/cppgc/heap-object-header_unittest.cc
new file mode 100644
index 0000000000..b062489cb3
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/heap-object-header_unittest.cc
@@ -0,0 +1,181 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/heap-object-header.h"
+
+#include <atomic>
+#include <memory>
+
+#include "include/cppgc/allocation.h"
+#include "src/base/atomic-utils.h"
+#include "src/base/macros.h"
+#include "src/base/platform/platform.h"
+#include "src/heap/cppgc/globals.h"
+#include "src/heap/cppgc/heap-object-header-inl.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+namespace internal {
+
+TEST(HeapObjectHeaderTest, Constructor) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_EQ(kSize, header.GetSize());
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_TRUE(header.IsInConstruction());
+  EXPECT_FALSE(header.IsMarked());
+}
+
+TEST(HeapObjectHeaderTest, Payload) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_EQ(reinterpret_cast<ConstAddress>(&header) + sizeof(HeapObjectHeader),
+            header.Payload());
+}
+
+TEST(HeapObjectHeaderTest, GetGCInfoIndex) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_EQ(kGCInfoIndex,
+            header.GetGCInfoIndex<HeapObjectHeader::AccessMode::kAtomic>());
+}
+
+TEST(HeapObjectHeaderTest, GetSize) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity * 23;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_EQ(kSize, header.GetSize());
+  EXPECT_EQ(kSize, header.GetSize<HeapObjectHeader::AccessMode::kAtomic>());
+}
+
+TEST(HeapObjectHeaderTest, IsLargeObject) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity * 23;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_EQ(false, header.IsLargeObject());
+  EXPECT_EQ(false,
+            header.IsLargeObject<HeapObjectHeader::AccessMode::kAtomic>());
+  HeapObjectHeader large_header(0, kGCInfoIndex + 1);
+  EXPECT_EQ(true, large_header.IsLargeObject());
+  EXPECT_EQ(
+      true,
+      large_header.IsLargeObject<HeapObjectHeader::AccessMode::kAtomic>());
+}
+
+TEST(HeapObjectHeaderTest, MarkObjectAsFullyConstructed) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_TRUE(header.IsInConstruction());
+  header.MarkAsFullyConstructed();
+  EXPECT_FALSE(header.IsInConstruction());
+  // Size shares the same bitfield and should be unaffected by
+  // MarkObjectAsFullyConstructed.
+  EXPECT_EQ(kSize, header.GetSize());
+}
+
+TEST(HeapObjectHeaderTest, TryMark) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity * 7;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_FALSE(header.IsMarked());
+  EXPECT_TRUE(header.TryMarkAtomic());
+  // GCInfoIndex shares the same bitfield and should be unaffected by
+  // TryMarkAtomic.
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_FALSE(header.TryMarkAtomic());
+  // GCInfoIndex shares the same bitfield and should be unaffected by
+  // TryMarkAtomic.
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_TRUE(header.IsMarked());
+}
+
+TEST(HeapObjectHeaderTest, Unmark) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = kAllocationGranularity * 7;
+  HeapObjectHeader header(kSize, kGCInfoIndex);
+  EXPECT_FALSE(header.IsMarked());
+  EXPECT_TRUE(header.TryMarkAtomic());
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_TRUE(header.IsMarked());
+  header.Unmark();
+  // GCInfoIndex shares the same bitfield and should be unaffected by Unmark.
+  EXPECT_EQ(kGCInfoIndex, header.GetGCInfoIndex());
+  EXPECT_FALSE(header.IsMarked());
+  HeapObjectHeader header2(kSize, kGCInfoIndex);
+  EXPECT_FALSE(header2.IsMarked());
+  EXPECT_TRUE(header2.TryMarkAtomic());
+  EXPECT_TRUE(header2.IsMarked());
+  header2.Unmark<HeapObjectHeader::AccessMode::kAtomic>();
+  // GCInfoIndex shares the same bitfield and should be unaffected by Unmark.
+  EXPECT_EQ(kGCInfoIndex, header2.GetGCInfoIndex());
+  EXPECT_FALSE(header2.IsMarked());
+}
+
+namespace {
+
+struct Payload {
+  volatile size_t value{5};
+};
+
+class ConcurrentGCThread final : public v8::base::Thread {
+ public:
+  explicit ConcurrentGCThread(HeapObjectHeader* header, Payload* payload)
+      : v8::base::Thread(Options("Thread accessing object.")),
+        header_(header),
+        payload_(payload) {}
+
+  void Run() final {
+    while (header_->IsInConstruction<HeapObjectHeader::AccessMode::kAtomic>()) {
+    }
+    USE(v8::base::AsAtomicPtr(const_cast<size_t*>(&payload_->value))
+            ->load(std::memory_order_relaxed));
+  }
+
+ private:
+  HeapObjectHeader* header_;
+  Payload* payload_;
+};
+
+}  // namespace
+
+TEST(HeapObjectHeaderTest, ConstructionBitProtectsNonAtomicWrites) {
+  // Object publishing: Test checks that non-atomic stores in the payload can be
+  // guarded using MarkObjectAsFullyConstructed/IsInConstruction. The test
+  // relies on TSAN to find data races.
+  constexpr size_t kSize =
+      (sizeof(HeapObjectHeader) + sizeof(Payload) + kAllocationMask) &
+      ~kAllocationMask;
+  typename std::aligned_storage<kSize, kAllocationGranularity>::type data;
+  HeapObjectHeader* header = new (&data) HeapObjectHeader(kSize, 1);
+  ConcurrentGCThread gc_thread(header,
+                               reinterpret_cast<Payload*>(header->Payload()));
+  CHECK(gc_thread.Start());
+  new (header->Payload()) Payload();
+  header->MarkAsFullyConstructed();
+  gc_thread.Join();
+}
+
+#ifdef DEBUG
+
+TEST(HeapObjectHeaderDeathTest, ConstructorTooLargeSize) {
+  constexpr GCInfoIndex kGCInfoIndex = 17;
+  constexpr size_t kSize = HeapObjectHeader::kMaxSize + 1;
+  EXPECT_DEATH_IF_SUPPORTED(HeapObjectHeader header(kSize, kGCInfoIndex), "");
+}
+
+TEST(HeapObjectHeaderDeathTest, ConstructorTooLargeGCInfoIndex) {
+  constexpr GCInfoIndex kGCInfoIndex = GCInfoTable::kMaxIndex + 1;
+  constexpr size_t kSize = kAllocationGranularity;
+  EXPECT_DEATH_IF_SUPPORTED(HeapObjectHeader header(kSize, kGCInfoIndex), "");
+}
+
+#endif  // DEBUG
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/run-all-unittests.cc b/deps/v8/test/unittests/heap/cppgc/run-all-unittests.cc
new file mode 100644
index 0000000000..cdc862e309
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/run-all-unittests.cc
@@ -0,0 +1,17 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/gmock/include/gmock/gmock.h"
+
+int main(int argc, char** argv) {
+  // Don't catch SEH exceptions and continue as the following tests might hang
+  // in an broken environment on windows.
+  testing::GTEST_FLAG(catch_exceptions) = false;
+
+  // Most unit-tests are multi-threaded, so enable thread-safe death-tests.
+  testing::FLAGS_gtest_death_test_style = "threadsafe";
+
+  testing::InitGoogleMock(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/deps/v8/test/unittests/heap/cppgc/stack_unittest.cc b/deps/v8/test/unittests/heap/cppgc/stack_unittest.cc
new file mode 100644
index 0000000000..435c06f83f
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/stack_unittest.cc
@@ -0,0 +1,256 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/cppgc/stack.h"
+
+#include <memory>
+#include <ostream>
+
+#include "include/v8config.h"
+#include "src/base/platform/platform.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+#if V8_OS_LINUX && (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
+#include <xmmintrin.h>
+#endif
+
+namespace cppgc {
+namespace internal {
+
+namespace {
+
+class GCStackTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    stack_.reset(new Stack(v8::base::Stack::GetStackStart()));
+  }
+
+  void TearDown() override { stack_.reset(); }
+
+  Stack* GetStack() const { return stack_.get(); }
+
+ private:
+  std::unique_ptr<Stack> stack_;
+};
+
+}  // namespace
+
+TEST_F(GCStackTest, IsOnStackForStackValue) {
+  void* dummy;
+  EXPECT_TRUE(GetStack()->IsOnStack(&dummy));
+}
+
+TEST_F(GCStackTest, IsOnStackForHeapValue) {
+  auto dummy = std::make_unique<int>();
+  EXPECT_FALSE(GetStack()->IsOnStack(dummy.get()));
+}
+
+#ifdef CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+namespace {
+
+class StackScanner final : public StackVisitor {
+ public:
+  struct Container {
+    std::unique_ptr<int> value;
+  };
+
+  StackScanner() : container_(new Container{}) {
+    container_->value = std::make_unique<int>();
+  }
+
+  void VisitPointer(const void* address) final {
+    if (address == container_->value.get()) found_ = true;
+  }
+
+  void Reset() { found_ = false; }
+  bool found() const { return found_; }
+  int* needle() const { return container_->value.get(); }
+
+ private:
+  std::unique_ptr<Container> container_;
+  bool found_ = false;
+};
+
+}  // namespace
+
+TEST_F(GCStackTest, IteratePointersFindsOnStackValue) {
+  auto scanner = std::make_unique<StackScanner>();
+
+  // No check that the needle is initially not found as on some platforms it
+  // may be part of the redzone or temporaries after setting it up throuhg
+  // StackScanner.
+  {
+    int* volatile tmp = scanner->needle();
+    USE(tmp);
+    GetStack()->IteratePointers(scanner.get());
+    EXPECT_TRUE(scanner->found());
+  }
+}
+
+TEST_F(GCStackTest, IteratePointersFindsOnStackValuePotentiallyUnaligned) {
+  auto scanner = std::make_unique<StackScanner>();
+
+  // No check that the needle is initially not found as on some platforms it
+  // may be part of the redzone or temporaries after setting it up throuhg
+  // StackScanner.
+  {
+    char a = 'c';
+    USE(a);
+    int* volatile tmp = scanner->needle();
+    USE(tmp);
+    GetStack()->IteratePointers(scanner.get());
+    EXPECT_TRUE(scanner->found());
+  }
+}
+
+namespace {
+
+void RecursivelyPassOnParameter(int* volatile p1, int* volatile p2,
+                                int* volatile p3, int* volatile p4,
+                                int* volatile p5, int* volatile p6,
+                                int* volatile p7, int* volatile p8,
+                                Stack* stack, StackVisitor* visitor) {
+  if (p1) {
+    RecursivelyPassOnParameter(nullptr, p1, nullptr, nullptr, nullptr, nullptr,
+                               nullptr, nullptr, stack, visitor);
+  } else if (p2) {
+    RecursivelyPassOnParameter(nullptr, nullptr, p2, nullptr, nullptr, nullptr,
+                               nullptr, nullptr, stack, visitor);
+  } else if (p3) {
+    RecursivelyPassOnParameter(nullptr, nullptr, nullptr, p3, nullptr, nullptr,
+                               nullptr, nullptr, stack, visitor);
+  } else if (p4) {
+    RecursivelyPassOnParameter(nullptr, nullptr, nullptr, nullptr, p4, nullptr,
+                               nullptr, nullptr, stack, visitor);
+  } else if (p5) {
+    RecursivelyPassOnParameter(nullptr, nullptr, nullptr, nullptr, nullptr, p5,
+                               nullptr, nullptr, stack, visitor);
+  } else if (p6) {
+    RecursivelyPassOnParameter(nullptr, nullptr, nullptr, nullptr, nullptr,
+                               nullptr, p6, nullptr, stack, visitor);
+  } else if (p7) {
+    RecursivelyPassOnParameter(nullptr, nullptr, nullptr, nullptr, nullptr,
+                               nullptr, nullptr, p7, stack, visitor);
+  } else if (p8) {
+    stack->IteratePointers(visitor);
+  }
+}
+
+}  // namespace
+
+TEST_F(GCStackTest, IteratePointersFindsParameter) {
+  auto scanner = std::make_unique<StackScanner>();
+  // No check that the needle is initially not found as on some platforms it
+  // may be part of the redzone or temporaries after setting it up throuhg
+  // StackScanner.
+  RecursivelyPassOnParameter(nullptr, nullptr, nullptr, nullptr, nullptr,
+                             nullptr, nullptr, scanner->needle(), GetStack(),
+                             scanner.get());
+  EXPECT_TRUE(scanner->found());
+}
+
+TEST_F(GCStackTest, IteratePointersFindsParameterInNestedFunction) {
+  auto scanner = std::make_unique<StackScanner>();
+  // No check that the needle is initially not found as on some platforms it
+  // may be part of the redzone or temporaries after setting it up throuhg
+  // StackScanner.
+  RecursivelyPassOnParameter(scanner->needle(), nullptr, nullptr, nullptr,
+                             nullptr, nullptr, nullptr, nullptr, GetStack(),
+                             scanner.get());
+  EXPECT_TRUE(scanner->found());
+}
+
+// The following test uses inline assembly and has been checked to work on clang
+// to verify that the stack-scanning trampoline pushes callee-saved registers.
+//
+// The test uses a macro loop as asm() can only be passed string literals.
+#ifdef __clang__
+#ifdef V8_TARGET_ARCH_X64
+#ifdef V8_OS_WIN
+
+// Excluded from test: rbp
+#define FOR_ALL_CALLEE_SAVED_REGS(V) \
+  V("rdi")                           \
+  V("rsi")                           \
+  V("rbx")                           \
+  V("r12")                           \
+  V("r13")                           \
+  V("r14")                           \
+  V("r15")
+
+#else  // !V8_OS_WIN
+
+// Excluded from test: rbp
+#define FOR_ALL_CALLEE_SAVED_REGS(V) \
+  V("rbx")                           \
+  V("r12")                           \
+  V("r13")                           \
+  V("r14")                           \
+  V("r15")
+
+#endif  // !V8_OS_WIN
+#endif  // V8_TARGET_ARCH_X64
+#endif  // __clang__
+
+#ifdef FOR_ALL_CALLEE_SAVED_REGS
+
+TEST_F(GCStackTest, IteratePointersFindsCalleeSavedRegisters) {
+  auto scanner = std::make_unique<StackScanner>();
+
+  // No check that the needle is initially not found as on some platforms it
+  // may be part of the redzone or temporaries after setting it up throuhg
+  // StackScanner.
+
+// First, clear all callee-saved registers.
+#define CLEAR_REGISTER(reg) asm("mov $0, %%" reg : : : reg);
+
+  FOR_ALL_CALLEE_SAVED_REGS(CLEAR_REGISTER)
+#undef CLEAR_REGISTER
+
+  // Keep local raw pointers to keep instruction sequences small below.
+  auto* local_stack = GetStack();
+  auto* local_scanner = scanner.get();
+
+// Moves |local_scanner->needle()| into a callee-saved register, leaving the
+// callee-saved register as the only register referencing the needle.
+// (Ignoring implementation-dependent dirty registers/stack.)
+#define KEEP_ALIVE_FROM_CALLEE_SAVED(reg)                                \
+  local_scanner->Reset();                                                \
+  /* This moves the temporary into the calee-saved register. */          \
+  asm("mov %0, %%" reg : : "r"(local_scanner->needle()) : reg);          \
+  /* Register is unprotected from here till the actual invocation. */    \
+  local_stack->IteratePointers(local_scanner);                           \
+  EXPECT_TRUE(local_scanner->found())                                    \
+      << "pointer in callee-saved register not found. register: " << reg \
+      << std::endl;                                                      \
+  /* Clear out the register again */                                     \
+  asm("mov $0, %%" reg : : : reg);
+
+  FOR_ALL_CALLEE_SAVED_REGS(KEEP_ALIVE_FROM_CALLEE_SAVED)
+#undef KEEP_ALIVE_FROM_CALLEE_SAVED
+#undef FOR_ALL_CALLEE_SAVED_REGS
+}
+#endif  // FOR_ALL_CALLEE_SAVED_REGS
+
+#if V8_OS_LINUX && (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
+class CheckStackAlignmentVisitor final : public StackVisitor {
+ public:
+  void VisitPointer(const void*) final {
+    float f[4] = {0.};
+    volatile auto xmm = ::_mm_load_ps(f);
+    USE(xmm);
+  }
+};
+
+TEST_F(GCStackTest, StackAlignment) {
+  auto checker = std::make_unique<CheckStackAlignmentVisitor>();
+  GetStack()->IteratePointers(checker.get());
+}
+#endif  // V8_OS_LINUX && (V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64)
+
+#endif  // CPPGC_SUPPORTS_CONSERVATIVE_STACK_SCAN
+
+}  // namespace internal
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/tests.cc b/deps/v8/test/unittests/heap/cppgc/tests.cc
new file mode 100644
index 0000000000..e67ac730d6
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/tests.cc
@@ -0,0 +1,36 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "test/unittests/heap/cppgc/tests.h"
+
+namespace cppgc {
+namespace testing {
+
+// static
+std::unique_ptr<cppgc::PageAllocator> TestWithPlatform::page_allocator_;
+
+// static
+void TestWithPlatform::SetUpTestSuite() {
+  page_allocator_.reset(new v8::base::PageAllocator());
+  cppgc::InitializePlatform(page_allocator_.get());
+}
+
+// static
+void TestWithPlatform::TearDownTestSuite() {
+  cppgc::ShutdownPlatform();
+  page_allocator_.reset();
+}
+
+void TestWithHeap::SetUp() {
+  heap_ = Heap::Create();
+  TestWithPlatform::SetUp();
+}
+
+void TestWithHeap::TearDown() {
+  heap_.reset();
+  TestWithPlatform::TearDown();
+}
+
+}  // namespace testing
+}  // namespace cppgc
diff --git a/deps/v8/test/unittests/heap/cppgc/tests.h b/deps/v8/test/unittests/heap/cppgc/tests.h
new file mode 100644
index 0000000000..d21f256444
--- /dev/null
+++ b/deps/v8/test/unittests/heap/cppgc/tests.h
@@ -0,0 +1,39 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_UNITTESTS_HEAP_CPPGC_TESTS_H_
+#define V8_UNITTESTS_HEAP_CPPGC_TESTS_H_
+
+#include "include/cppgc/heap.h"
+#include "include/cppgc/platform.h"
+#include "src/base/page-allocator.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cppgc {
+namespace testing {
+
+class TestWithPlatform : public ::testing::Test {
+ protected:
+  static void SetUpTestSuite();
+  static void TearDownTestSuite();
+
+ private:
+  static std::unique_ptr<cppgc::PageAllocator> page_allocator_;
+};
+
+class TestWithHeap : public TestWithPlatform {
+ protected:
+  void SetUp() override;
+  void TearDown() override;
+
+  Heap* GetHeap() const { return heap_.get(); }
+
+ private:
+  std::unique_ptr<cppgc::Heap> heap_;
+};
+
+}  // namespace testing
+}  // namespace cppgc
+
+#endif  // V8_UNITTESTS_HEAP_CPPGC_TESTS_H_
diff --git a/deps/v8/test/unittests/heap/gc-idle-time-handler-unittest.cc b/deps/v8/test/unittests/heap/gc-idle-time-handler-unittest.cc
index b3901d74b0..c46ee35095 100644
--- a/deps/v8/test/unittests/heap/gc-idle-time-handler-unittest.cc
+++ b/deps/v8/test/unittests/heap/gc-idle-time-handler-unittest.cc
@@ -30,7 +30,6 @@ class GCIdleTimeHandlerTest : public ::testing::Test {
 
   static const size_t kSizeOfObjects = 100 * MB;
   static const size_t kMarkCompactSpeed = 200 * KB;
-  static const size_t kMarkingSpeed = 200 * KB;
 
  private:
   GCIdleTimeHandler handler_;
@@ -74,20 +73,6 @@ TEST(GCIdleTimeHandler, EstimateMarkingStepSizeOverflow2) {
 }
 
 
-TEST_F(GCIdleTimeHandlerTest, ShouldDoFinalIncrementalMarkCompact) {
-  size_t idle_time_ms = 16;
-  EXPECT_TRUE(GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
-      idle_time_ms, 0, 0));
-}
-
-
-TEST_F(GCIdleTimeHandlerTest, DontDoFinalIncrementalMarkCompact) {
-  size_t idle_time_ms = 1;
-  EXPECT_FALSE(GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
-      idle_time_ms, kSizeOfObjects, kMarkingSpeed));
-}
-
-
 TEST_F(GCIdleTimeHandlerTest, ContextDisposeLowRate) {
   if (!handler()->Enabled()) return;
   GCIdleTimeHeapState heap_state = DefaultHeapState();
diff --git a/deps/v8/test/unittests/heap/local-heap-unittest.cc b/deps/v8/test/unittests/heap/local-heap-unittest.cc
new file mode 100644
index 0000000000..bf6aad6efc
--- /dev/null
+++ b/deps/v8/test/unittests/heap/local-heap-unittest.cc
@@ -0,0 +1,38 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/local-heap.h"
+#include "src/heap/heap.h"
+#include "src/heap/safepoint.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace internal {
+
+using LocalHeapTest = TestWithIsolate;
+
+TEST_F(LocalHeapTest, Initialize) {
+  Heap* heap = i_isolate()->heap();
+
+  {
+    LocalHeap lh1(heap);
+    CHECK(heap->safepoint()->ContainsLocalHeap(&lh1));
+    LocalHeap lh2(heap);
+    CHECK(heap->safepoint()->ContainsLocalHeap(&lh2));
+
+    {
+      LocalHeap lh3(heap);
+      CHECK(heap->safepoint()->ContainsLocalHeap(&lh3));
+    }
+
+    CHECK(heap->safepoint()->ContainsLocalHeap(&lh1));
+    CHECK(heap->safepoint()->ContainsLocalHeap(&lh2));
+  }
+
+  CHECK(!heap->safepoint()->ContainsAnyLocalHeap());
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/test/unittests/heap/off-thread-factory-unittest.cc b/deps/v8/test/unittests/heap/off-thread-factory-unittest.cc
index 2c7bd639a8..0592d7b2db 100644
--- a/deps/v8/test/unittests/heap/off-thread-factory-unittest.cc
+++ b/deps/v8/test/unittests/heap/off-thread-factory-unittest.cc
@@ -8,65 +8,139 @@
 #include <memory>
 
 #include "src/ast/ast-value-factory.h"
+#include "src/ast/ast.h"
+#include "src/ast/scopes.h"
+#include "src/common/assert-scope.h"
+#include "src/common/globals.h"
+#include "src/execution/off-thread-isolate.h"
 #include "src/handles/handles-inl.h"
 #include "src/handles/handles.h"
-#include "src/heap/off-thread-factory.h"
+#include "src/heap/off-thread-factory-inl.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/script.h"
+#include "src/objects/shared-function-info.h"
 #include "src/objects/string.h"
+#include "src/parsing/parse-info.h"
+#include "src/parsing/parser.h"
+#include "src/parsing/rewriter.h"
+#include "src/parsing/scanner-character-streams.h"
+#include "src/parsing/scanner.h"
+#include "src/strings/unicode-inl.h"
+#include "src/utils/utils.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 
+class OffThreadIsolate;
+
+namespace {
+
+std::vector<uint16_t> DecodeUtf8(const std::string& string) {
+  if (string.empty()) return {};
+
+  auto utf8_data =
+      Vector<const uint8_t>::cast(VectorOf(string.data(), string.length()));
+  Utf8Decoder decoder(utf8_data);
+
+  std::vector<uint16_t> utf16(decoder.utf16_length());
+  decoder.Decode(&utf16[0], utf8_data);
+
+  return utf16;
+}
+
+}  // namespace
+
 class OffThreadFactoryTest : public TestWithIsolateAndZone {
  public:
   OffThreadFactoryTest()
-      : TestWithIsolateAndZone(), off_thread_factory_(isolate()) {}
+      : TestWithIsolateAndZone(),
+        parse_info_(isolate()),
+        off_thread_isolate_(isolate(), parse_info_.zone()) {}
+
+  FunctionLiteral* ParseProgram(const char* source) {
+    auto utf16_source = DecodeUtf8(source);
 
-  OffThreadFactory* off_thread_factory() { return &off_thread_factory_; }
+    // Normally this would be an external string or whatever, we don't have to
+    // worry about it for now.
+    source_string_ =
+        factory()->NewStringFromUtf8(CStrVector(source)).ToHandleChecked();
+
+    parse_info_.set_character_stream(
+        ScannerStream::ForTesting(utf16_source.data(), utf16_source.size()));
+    parse_info_.set_toplevel();
+    parse_info_.set_allow_lazy_parsing();
+
+    {
+      DisallowHeapAllocation no_allocation;
+      DisallowHandleAllocation no_handles;
+      DisallowHeapAccess no_heap_access;
+
+      Parser parser(parse_info());
+      parser.InitializeEmptyScopeChain(parse_info());
+      parser.ParseOnBackground(parse_info());
+
+      CHECK(DeclarationScope::Analyze(parse_info()));
+    }
+
+    parse_info()->ast_value_factory()->Internalize(off_thread_isolate());
+    DeclarationScope::AllocateScopeInfos(parse_info(), off_thread_isolate());
+
+    script_ = parse_info_.CreateScript(off_thread_isolate(),
+                                       off_thread_factory()->empty_string(),
+                                       ScriptOriginOptions());
+
+    // Create the SFI list on the script so that SFI SetScript works.
+    Handle<WeakFixedArray> infos = off_thread_factory()->NewWeakFixedArray(
+        parse_info()->max_function_literal_id() + 1, AllocationType::kOld);
+    script_->set_shared_function_infos(*infos);
+
+    return parse_info()->literal();
+  }
+
+  ParseInfo* parse_info() { return &parse_info_; }
+
+  Handle<Script> script() { return script_; }
+
+  OffThreadIsolate* off_thread_isolate() { return &off_thread_isolate_; }
+  OffThreadFactory* off_thread_factory() {
+    return off_thread_isolate()->factory();
+  }
 
   // We only internalize strings which are referred to in other slots, so create
   // a wrapper pointing at the off_thread_string.
-  OffThreadHandle<FixedArray> WrapString(OffThreadHandle<String> string) {
+  Handle<FixedArray> WrapString(Handle<String> string) {
     // TODO(leszeks): Replace with a different factory method (e.g. FixedArray)
     // once OffThreadFactory supports it.
     return off_thread_factory()->StringWrapperForTest(string);
   }
 
  private:
-  OffThreadFactory off_thread_factory_;
+  ParseInfo parse_info_;
+  OffThreadIsolate off_thread_isolate_;
+  Handle<String> source_string_;
+  Handle<Script> script_;
 };
 
-TEST_F(OffThreadFactoryTest, HandleOrOffThreadHandle_IsNullWhenConstructed) {
-  // Default constructed HandleOrOffThreadHandles should be considered both null
-  // and uninitialized.
-  EXPECT_TRUE(HandleOrOffThreadHandle<HeapObject>().is_null());
-#ifdef DEBUG
-  EXPECT_TRUE(!HandleOrOffThreadHandle<HeapObject>().is_initialized());
-#endif
-
-  // Default constructed HandleOrOffThreadHandles should work as both null
-  // handles and null off-thread handles.
-  EXPECT_TRUE(HandleOrOffThreadHandle<HeapObject>().get<Factory>().is_null());
-  EXPECT_TRUE(
-      HandleOrOffThreadHandle<HeapObject>().get<OffThreadFactory>().is_null());
-}
-
 TEST_F(OffThreadFactoryTest, OneByteInternalizedString_IsAddedToStringTable) {
   Vector<const uint8_t> string_vector = StaticCharVector("foo");
   uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>(
       string_vector.begin(), string_vector.length(), HashSeed(isolate()));
 
-  OffThreadHandle<String> off_thread_string =
-      off_thread_factory()->NewOneByteInternalizedString(string_vector,
-                                                         hash_field);
+  FixedArray off_thread_wrapper;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
 
-  OffThreadHandle<FixedArray> off_thread_wrapper =
-      off_thread_factory()->StringWrapperForTest(off_thread_string);
+    Handle<String> off_thread_string =
+        off_thread_factory()->NewOneByteInternalizedString(string_vector,
+                                                           hash_field);
 
-  off_thread_factory()->FinishOffThread();
+    off_thread_wrapper =
+        *off_thread_factory()->StringWrapperForTest(off_thread_string);
+    off_thread_factory()->FinishOffThread();
+  }
 
-  Handle<FixedArray> wrapper = handle(*off_thread_wrapper, isolate());
+  Handle<FixedArray> wrapper = handle(off_thread_wrapper, isolate());
   off_thread_factory()->Publish(isolate());
 
   Handle<String> string = handle(String::cast(wrapper->get(0)), isolate());
@@ -92,22 +166,25 @@ TEST_F(OffThreadFactoryTest,
   uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>(
       string_vector.begin(), string_vector.length(), HashSeed(isolate()));
 
-  OffThreadHandle<String> off_thread_string_1 =
-      off_thread_factory()->NewOneByteInternalizedString(string_vector,
-                                                         hash_field);
-  OffThreadHandle<String> off_thread_string_2 =
-      off_thread_factory()->NewOneByteInternalizedString(string_vector,
-                                                         hash_field);
-
-  OffThreadHandle<FixedArray> off_thread_wrapper_1 =
-      WrapString(off_thread_string_1);
-  OffThreadHandle<FixedArray> off_thread_wrapper_2 =
-      WrapString(off_thread_string_2);
-
-  off_thread_factory()->FinishOffThread();
+  FixedArray off_thread_wrapper_1;
+  FixedArray off_thread_wrapper_2;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
+
+    Handle<String> off_thread_string_1 =
+        off_thread_factory()->NewOneByteInternalizedString(string_vector,
+                                                           hash_field);
+    Handle<String> off_thread_string_2 =
+        off_thread_factory()->NewOneByteInternalizedString(string_vector,
+                                                           hash_field);
+
+    off_thread_wrapper_1 = *WrapString(off_thread_string_1);
+    off_thread_wrapper_2 = *WrapString(off_thread_string_2);
+    off_thread_factory()->FinishOffThread();
+  }
 
-  Handle<FixedArray> wrapper_1 = handle(*off_thread_wrapper_1, isolate());
-  Handle<FixedArray> wrapper_2 = handle(*off_thread_wrapper_2, isolate());
+  Handle<FixedArray> wrapper_1 = handle(off_thread_wrapper_1, isolate());
+  Handle<FixedArray> wrapper_2 = handle(off_thread_wrapper_2, isolate());
   off_thread_factory()->Publish(isolate());
 
   Handle<String> string_1 = handle(String::cast(wrapper_1->get(0)), isolate());
@@ -124,14 +201,17 @@ TEST_F(OffThreadFactoryTest, AstRawString_IsInternalized) {
 
   const AstRawString* raw_string = ast_value_factory.GetOneByteString("foo");
 
-  ast_value_factory.Internalize(off_thread_factory());
+  FixedArray off_thread_wrapper;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
 
-  OffThreadHandle<FixedArray> off_thread_wrapper =
-      WrapString(raw_string->string().get<OffThreadFactory>());
+    ast_value_factory.Internalize(off_thread_isolate());
 
-  off_thread_factory()->FinishOffThread();
+    off_thread_wrapper = *WrapString(raw_string->string());
+    off_thread_factory()->FinishOffThread();
+  }
 
-  Handle<FixedArray> wrapper = handle(*off_thread_wrapper, isolate());
+  Handle<FixedArray> wrapper = handle(off_thread_wrapper, isolate());
   off_thread_factory()->Publish(isolate());
 
   Handle<String> string = handle(String::cast(wrapper->get(0)), isolate());
@@ -144,20 +224,24 @@ TEST_F(OffThreadFactoryTest, AstConsString_CreatesConsString) {
   AstValueFactory ast_value_factory(zone(), isolate()->ast_string_constants(),
                                     HashSeed(isolate()));
 
-  const AstRawString* foo_string = ast_value_factory.GetOneByteString("foo");
-  const AstRawString* bar_string =
-      ast_value_factory.GetOneByteString("bar-plus-padding-for-length");
-  const AstConsString* foobar_string =
-      ast_value_factory.NewConsString(foo_string, bar_string);
+  FixedArray off_thread_wrapper;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
 
-  ast_value_factory.Internalize(off_thread_factory());
+    const AstRawString* foo_string = ast_value_factory.GetOneByteString("foo");
+    const AstRawString* bar_string =
+        ast_value_factory.GetOneByteString("bar-plus-padding-for-length");
+    AstConsString* foobar_string =
+        ast_value_factory.NewConsString(foo_string, bar_string);
 
-  OffThreadHandle<FixedArray> off_thread_wrapper =
-      WrapString(foobar_string->string().get<OffThreadFactory>());
+    ast_value_factory.Internalize(off_thread_isolate());
 
-  off_thread_factory()->FinishOffThread();
+    off_thread_wrapper =
+        *WrapString(foobar_string->GetString(off_thread_isolate()));
+    off_thread_factory()->FinishOffThread();
+  }
 
-  Handle<FixedArray> wrapper = handle(*off_thread_wrapper, isolate());
+  Handle<FixedArray> wrapper = handle(off_thread_wrapper, isolate());
   off_thread_factory()->Publish(isolate());
 
   Handle<String> string = handle(String::cast(wrapper->get(0)), isolate());
@@ -167,5 +251,111 @@ TEST_F(OffThreadFactoryTest, AstConsString_CreatesConsString) {
       "foobar-plus-padding-for-length")));
 }
 
+TEST_F(OffThreadFactoryTest, EmptyScript) {
+  FunctionLiteral* program = ParseProgram("");
+
+  SharedFunctionInfo shared;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
+
+    shared = *off_thread_factory()->NewSharedFunctionInfoForLiteral(
+        program, script(), true);
+
+    off_thread_factory()->FinishOffThread();
+  }
+
+  Handle<SharedFunctionInfo> root_sfi = handle(shared, isolate());
+  off_thread_factory()->Publish(isolate());
+
+  EXPECT_EQ(root_sfi->function_literal_id(), 0);
+}
+
+TEST_F(OffThreadFactoryTest, LazyFunction) {
+  FunctionLiteral* program = ParseProgram("function lazy() {}");
+  FunctionLiteral* lazy = program->scope()
+                              ->declarations()
+                              ->AtForTest(0)
+                              ->AsFunctionDeclaration()
+                              ->fun();
+
+  SharedFunctionInfo shared;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
+
+    shared = *off_thread_factory()->NewSharedFunctionInfoForLiteral(
+        lazy, script(), true);
+
+    off_thread_factory()->FinishOffThread();
+  }
+
+  Handle<SharedFunctionInfo> lazy_sfi = handle(shared, isolate());
+  off_thread_factory()->Publish(isolate());
+
+  EXPECT_EQ(lazy_sfi->function_literal_id(), 1);
+  EXPECT_TRUE(lazy_sfi->Name().IsOneByteEqualTo(CStrVector("lazy")));
+  EXPECT_FALSE(lazy_sfi->is_compiled());
+  EXPECT_TRUE(lazy_sfi->HasUncompiledDataWithoutPreparseData());
+}
+
+TEST_F(OffThreadFactoryTest, EagerFunction) {
+  FunctionLiteral* program = ParseProgram("(function eager() {})");
+  FunctionLiteral* eager = program->body()
+                               ->at(0)
+                               ->AsExpressionStatement()
+                               ->expression()
+                               ->AsFunctionLiteral();
+
+  SharedFunctionInfo shared;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
+
+    shared = *off_thread_factory()->NewSharedFunctionInfoForLiteral(
+        eager, script(), true);
+
+    off_thread_factory()->FinishOffThread();
+  }
+
+  Handle<SharedFunctionInfo> eager_sfi = handle(shared, isolate());
+  off_thread_factory()->Publish(isolate());
+
+  EXPECT_EQ(eager_sfi->function_literal_id(), 1);
+  EXPECT_TRUE(eager_sfi->Name().IsOneByteEqualTo(CStrVector("eager")));
+  EXPECT_FALSE(eager_sfi->HasUncompiledData());
+  // TODO(leszeks): Allocate bytecode and enable these checks.
+  // EXPECT_TRUE(eager_sfi->is_compiled());
+  // EXPECT_TRUE(eager_sfi->HasBytecodeArray());
+}
+
+TEST_F(OffThreadFactoryTest, ImplicitNameFunction) {
+  FunctionLiteral* program = ParseProgram("let implicit_name = function() {}");
+  FunctionLiteral* implicit_name = program->body()
+                                       ->at(0)
+                                       ->AsBlock()
+                                       ->statements()
+                                       ->at(0)
+                                       ->AsExpressionStatement()
+                                       ->expression()
+                                       ->AsAssignment()
+                                       ->value()
+                                       ->AsFunctionLiteral();
+
+  SharedFunctionInfo shared;
+  {
+    OffThreadHandleScope handle_scope(off_thread_isolate());
+
+    shared = *off_thread_factory()->NewSharedFunctionInfoForLiteral(
+        implicit_name, script(), true);
+
+    off_thread_factory()->FinishOffThread();
+  }
+
+  Handle<SharedFunctionInfo> implicit_name_sfi = handle(shared, isolate());
+  off_thread_factory()->Publish(isolate());
+
+  EXPECT_EQ(implicit_name_sfi->function_literal_id(), 1);
+  EXPECT_TRUE(
+      implicit_name_sfi->Name().IsOneByteEqualTo(CStrVector("implicit_name")));
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/unittests/heap/safepoint-unittest.cc b/deps/v8/test/unittests/heap/safepoint-unittest.cc
new file mode 100644
index 0000000000..462992f5fd
--- /dev/null
+++ b/deps/v8/test/unittests/heap/safepoint-unittest.cc
@@ -0,0 +1,139 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/heap/safepoint.h"
+#include "src/base/platform/mutex.h"
+#include "src/base/platform/platform.h"
+#include "src/heap/heap.h"
+#include "src/heap/local-heap.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace internal {
+
+using SafepointTest = TestWithIsolate;
+
+TEST_F(SafepointTest, ReachSafepointWithoutLocalHeaps) {
+  Heap* heap = i_isolate()->heap();
+  bool run = false;
+  {
+    SafepointScope scope(heap);
+    run = true;
+  }
+  CHECK(run);
+}
+
+class ParkedThread final : public v8::base::Thread {
+ public:
+  ParkedThread(Heap* heap, base::Mutex* mutex)
+      : v8::base::Thread(base::Thread::Options("ThreadWithLocalHeap")),
+        heap_(heap),
+        mutex_(mutex) {}
+
+  void Run() override {
+    LocalHeap local_heap(heap_);
+
+    if (mutex_) {
+      ParkedScope scope(&local_heap);
+      base::MutexGuard guard(mutex_);
+    }
+  }
+
+  Heap* heap_;
+  base::Mutex* mutex_;
+};
+
+TEST_F(SafepointTest, StopParkedThreads) {
+  Heap* heap = i_isolate()->heap();
+
+  int safepoints = 0;
+
+  const int kThreads = 10;
+  const int kRuns = 5;
+
+  for (int run = 0; run < kRuns; run++) {
+    base::Mutex mutex;
+    std::vector<ParkedThread*> threads;
+
+    mutex.Lock();
+
+    for (int i = 0; i < kThreads; i++) {
+      ParkedThread* thread =
+          new ParkedThread(heap, i % 2 == 0 ? &mutex : nullptr);
+      CHECK(thread->Start());
+      threads.push_back(thread);
+    }
+
+    {
+      SafepointScope scope(heap);
+      safepoints++;
+    }
+    mutex.Unlock();
+
+    for (ParkedThread* thread : threads) {
+      thread->Join();
+      delete thread;
+    }
+  }
+
+  CHECK_EQ(safepoints, kRuns);
+}
+
+static const int kRuns = 10000;
+
+class RunningThread final : public v8::base::Thread {
+ public:
+  RunningThread(Heap* heap, std::atomic<int>* counter)
+      : v8::base::Thread(base::Thread::Options("ThreadWithLocalHeap")),
+        heap_(heap),
+        counter_(counter) {}
+
+  void Run() override {
+    LocalHeap local_heap(heap_);
+
+    for (int i = 0; i < kRuns; i++) {
+      counter_->fetch_add(1);
+      if (i % 100 == 0) local_heap.Safepoint();
+    }
+  }
+
+  Heap* heap_;
+  std::atomic<int>* counter_;
+};
+
+TEST_F(SafepointTest, StopRunningThreads) {
+  Heap* heap = i_isolate()->heap();
+
+  const int kThreads = 10;
+  const int kRuns = 5;
+  const int kSafepoints = 3;
+  int safepoint_count = 0;
+
+  for (int run = 0; run < kRuns; run++) {
+    std::atomic<int> counter(0);
+    std::vector<RunningThread*> threads;
+
+    for (int i = 0; i < kThreads; i++) {
+      RunningThread* thread = new RunningThread(heap, &counter);
+      CHECK(thread->Start());
+      threads.push_back(thread);
+    }
+
+    for (int i = 0; i < kSafepoints; i++) {
+      SafepointScope scope(heap);
+      safepoint_count++;
+    }
+
+    for (RunningThread* thread : threads) {
+      thread->Join();
+      delete thread;
+    }
+  }
+
+  CHECK_EQ(safepoint_count, kRuns * kSafepoints);
+}
+
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/test/unittests/heap/scavenge-job-unittest.cc b/deps/v8/test/unittests/heap/scavenge-job-unittest.cc
deleted file mode 100644
index 36d089f03b..0000000000
--- a/deps/v8/test/unittests/heap/scavenge-job-unittest.cc
+++ /dev/null
@@ -1,114 +0,0 @@
-// Copyright 2014 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <limits>
-
-#include "src/common/globals.h"
-#include "src/heap/scavenge-job.h"
-#include "src/utils/utils.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace v8 {
-namespace internal {
-
-const size_t kScavengeSpeedInBytesPerMs = 500 * KB;
-const size_t kNewSpaceCapacity = 8 * MB;
-
-
-TEST(ScavengeJob, AllocationLimitEmptyNewSpace) {
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(
-      kScavengeSpeedInBytesPerMs, 0, kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, AllocationLimitFullNewSpace) {
-  EXPECT_TRUE(ScavengeJob::ReachedIdleAllocationLimit(
-      kScavengeSpeedInBytesPerMs, kNewSpaceCapacity, kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, AllocationLimitUnknownScavengeSpeed) {
-  size_t expected_size = ScavengeJob::kInitialScavengeSpeedInBytesPerMs *
-                             ScavengeJob::kAverageIdleTimeMs -
-                         ScavengeJob::kBytesAllocatedBeforeNextIdleTask;
-  expected_size = Max(expected_size, ScavengeJob::kMinAllocationLimit);
-
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(0, expected_size - 1,
-                                                       kNewSpaceCapacity));
-  EXPECT_TRUE(ScavengeJob::ReachedIdleAllocationLimit(0, expected_size,
-                                                      kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, AllocationLimitLowScavengeSpeed) {
-  size_t scavenge_speed = 1 * KB;
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(
-      scavenge_speed, ScavengeJob::kMinAllocationLimit - 1, kNewSpaceCapacity));
-  EXPECT_TRUE(ScavengeJob::ReachedIdleAllocationLimit(
-      scavenge_speed, ScavengeJob::kMinAllocationLimit, kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, AllocationLimitAverageScavengeSpeed) {
-  size_t expected_size =
-      kScavengeSpeedInBytesPerMs * ScavengeJob::kAverageIdleTimeMs -
-      ScavengeJob::kBytesAllocatedBeforeNextIdleTask;
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(
-      kScavengeSpeedInBytesPerMs, ScavengeJob::kMinAllocationLimit,
-      kNewSpaceCapacity));
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(
-      kScavengeSpeedInBytesPerMs, expected_size - 1, kNewSpaceCapacity));
-  EXPECT_TRUE(ScavengeJob::ReachedIdleAllocationLimit(
-      kScavengeSpeedInBytesPerMs, expected_size, kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, AllocationLimitHighScavengeSpeed) {
-  size_t scavenge_speed = kNewSpaceCapacity;
-  size_t expected_size =
-      static_cast<size_t>(
-          kNewSpaceCapacity *
-          ScavengeJob::kMaxAllocationLimitAsFractionOfNewSpace) -
-      ScavengeJob::kBytesAllocatedBeforeNextIdleTask;
-  EXPECT_FALSE(ScavengeJob::ReachedIdleAllocationLimit(
-      scavenge_speed, expected_size - 1, kNewSpaceCapacity));
-  EXPECT_TRUE(ScavengeJob::ReachedIdleAllocationLimit(
-      scavenge_speed, expected_size + 1, kNewSpaceCapacity));
-}
-
-
-TEST(ScavengeJob, EnoughIdleTimeForScavengeUnknownScavengeSpeed) {
-  size_t scavenge_speed = ScavengeJob::kInitialScavengeSpeedInBytesPerMs;
-  size_t new_space_size = 1 * MB;
-  size_t expected_time = (new_space_size + scavenge_speed - 1) / scavenge_speed;
-  EXPECT_TRUE(
-      ScavengeJob::EnoughIdleTimeForScavenge(expected_time, 0, new_space_size));
-  EXPECT_FALSE(ScavengeJob::EnoughIdleTimeForScavenge(expected_time - 1, 0,
-                                                      new_space_size));
-}
-
-
-TEST(ScavengeJob, EnoughIdleTimeForScavengeLowScavengeSpeed) {
-  size_t scavenge_speed = 1 * KB;
-  size_t new_space_size = 1 * MB;
-  size_t expected_time = (new_space_size + scavenge_speed - 1) / scavenge_speed;
-  EXPECT_TRUE(ScavengeJob::EnoughIdleTimeForScavenge(
-      expected_time, scavenge_speed, new_space_size));
-  EXPECT_FALSE(ScavengeJob::EnoughIdleTimeForScavenge(
-      expected_time - 1, scavenge_speed, new_space_size));
-}
-
-
-TEST(ScavengeJob, EnoughIdleTimeForScavengeHighScavengeSpeed) {
-  size_t scavenge_speed = kNewSpaceCapacity;
-  size_t new_space_size = 1 * MB;
-  size_t expected_time = (new_space_size + scavenge_speed - 1) / scavenge_speed;
-  EXPECT_TRUE(ScavengeJob::EnoughIdleTimeForScavenge(
-      expected_time, scavenge_speed, new_space_size));
-  EXPECT_FALSE(ScavengeJob::EnoughIdleTimeForScavenge(
-      expected_time - 1, scavenge_speed, new_space_size));
-}
-
-}  // namespace internal
-}  // namespace v8
diff --git a/deps/v8/test/unittests/heap/worklist-unittest.cc b/deps/v8/test/unittests/heap/worklist-unittest.cc
index b7e1231424..a12dcb0cee 100644
--- a/deps/v8/test/unittests/heap/worklist-unittest.cc
+++ b/deps/v8/test/unittests/heap/worklist-unittest.cc
@@ -148,13 +148,16 @@ TEST(WorkListTest, LocalPushStaysPrivate) {
   SomeObject dummy;
   SomeObject* retrieved = nullptr;
   EXPECT_TRUE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
   EXPECT_TRUE(worklist_view1.Push(&dummy));
   EXPECT_FALSE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
   EXPECT_FALSE(worklist_view2.Pop(&retrieved));
   EXPECT_EQ(nullptr, retrieved);
   EXPECT_TRUE(worklist_view1.Pop(&retrieved));
   EXPECT_EQ(&dummy, retrieved);
   EXPECT_TRUE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
 }
 
 TEST(WorkListTest, GlobalUpdateNull) {
@@ -168,6 +171,7 @@ TEST(WorkListTest, GlobalUpdateNull) {
   EXPECT_TRUE(worklist_view.Push(object));
   worklist.Update([](SomeObject* object, SomeObject** out) { return false; });
   EXPECT_TRUE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
 }
 
 TEST(WorkListTest, GlobalUpdate) {
@@ -209,6 +213,7 @@ TEST(WorkListTest, FlushToGlobalPushSegment) {
   objectA = reinterpret_cast<SomeObject*>(&objectA);
   EXPECT_TRUE(worklist_view0.Push(objectA));
   worklist.FlushToGlobal(0);
+  EXPECT_EQ(1U, worklist.GlobalPoolSize());
   EXPECT_TRUE(worklist_view1.Pop(&object));
 }
 
@@ -223,6 +228,7 @@ TEST(WorkListTest, FlushToGlobalPopSegment) {
   EXPECT_TRUE(worklist_view0.Push(objectA));
   EXPECT_TRUE(worklist_view0.Pop(&object));
   worklist.FlushToGlobal(0);
+  EXPECT_EQ(1U, worklist.GlobalPoolSize());
   EXPECT_TRUE(worklist_view1.Pop(&object));
 }
 
@@ -235,8 +241,10 @@ TEST(WorkListTest, Clear) {
     EXPECT_TRUE(worklist_view.Push(object));
   }
   EXPECT_TRUE(worklist_view.Push(object));
+  EXPECT_EQ(1U, worklist.GlobalPoolSize());
   worklist.Clear();
   EXPECT_TRUE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
 }
 
 TEST(WorkListTest, SingleSegmentSteal) {
@@ -252,6 +260,7 @@ TEST(WorkListTest, SingleSegmentSteal) {
   EXPECT_TRUE(worklist_view1.Push(nullptr));
   EXPECT_TRUE(worklist_view1.Pop(&retrieved));
   EXPECT_EQ(nullptr, retrieved);
+  EXPECT_EQ(1U, worklist.GlobalPoolSize());
   // Stealing.
   for (size_t i = 0; i < TestWorklist::kSegmentCapacity; i++) {
     EXPECT_TRUE(worklist_view2.Pop(&retrieved));
@@ -259,6 +268,7 @@ TEST(WorkListTest, SingleSegmentSteal) {
     EXPECT_FALSE(worklist_view1.Pop(&retrieved));
   }
   EXPECT_TRUE(worklist.IsEmpty());
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
 }
 
 TEST(WorkListTest, MultipleSegmentsStolen) {
@@ -280,11 +290,13 @@ TEST(WorkListTest, MultipleSegmentsStolen) {
   EXPECT_TRUE(worklist_view1.Push(&dummy3));
   EXPECT_TRUE(worklist_view1.Pop(&retrieved));
   EXPECT_EQ(&dummy3, retrieved);
+  EXPECT_EQ(2U, worklist.GlobalPoolSize());
   // Stealing.
   EXPECT_TRUE(worklist_view2.Pop(&retrieved));
   SomeObject* const expect_bag2 = retrieved;
   EXPECT_TRUE(worklist_view3.Pop(&retrieved));
   SomeObject* const expect_bag3 = retrieved;
+  EXPECT_EQ(0U, worklist.GlobalPoolSize());
   EXPECT_NE(expect_bag2, expect_bag3);
   EXPECT_TRUE(expect_bag2 == &dummy1 || expect_bag2 == &dummy2);
   EXPECT_TRUE(expect_bag3 == &dummy1 || expect_bag3 == &dummy2);
@@ -313,10 +325,13 @@ TEST(WorkListTest, MergeGlobalPool) {
   EXPECT_TRUE(worklist_view1.Push(nullptr));
   EXPECT_TRUE(worklist_view1.Pop(&retrieved));
   EXPECT_EQ(nullptr, retrieved);
+  EXPECT_EQ(1U, worklist1.GlobalPoolSize());
   // Merging global pool into a new Worklist.
   TestWorklist worklist2;
   TestWorklist::View worklist_view2(&worklist2, 0);
+  EXPECT_EQ(0U, worklist2.GlobalPoolSize());
   worklist2.MergeGlobalPool(&worklist1);
+  EXPECT_EQ(1U, worklist2.GlobalPoolSize());
   EXPECT_FALSE(worklist2.IsEmpty());
   for (size_t i = 0; i < TestWorklist::kSegmentCapacity; i++) {
     EXPECT_TRUE(worklist_view2.Pop(&retrieved));
diff --git a/deps/v8/test/unittests/interpreter/bytecode-array-builder-unittest.cc b/deps/v8/test/unittests/interpreter/bytecode-array-builder-unittest.cc
index 7591a30f6b..cc7ca63061 100644
--- a/deps/v8/test/unittests/interpreter/bytecode-array-builder-unittest.cc
+++ b/deps/v8/test/unittests/interpreter/bytecode-array-builder-unittest.cc
@@ -79,8 +79,7 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
       .StoreAccumulatorInRegister(wide);
 
   // Emit Ldar and Star taking care to foil the register optimizer.
-  builder.StackCheck(0)
-      .LoadAccumulatorWithRegister(other)
+  builder.LoadAccumulatorWithRegister(other)
       .BinaryOperation(Token::ADD, reg, 1)
       .StoreAccumulatorInRegister(reg)
       .LoadNull();
@@ -312,7 +311,7 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
         .Bind(&after_jump10)
         .JumpIfFalse(ToBooleanMode::kAlreadyBoolean, &after_jump11)
         .Bind(&after_jump11)
-        .JumpLoop(&loop_header, 0)
+        .JumpLoop(&loop_header, 0, 0)
         .Bind(&after_loop);
   }
 
@@ -343,9 +342,6 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
   // Emit set pending message bytecode.
   builder.SetPendingMessage();
 
-  // Emit stack check bytecode.
-  builder.StackCheck(0);
-
   // Emit throw and re-throw in it's own basic block so that the rest of the
   // code isn't omitted due to being dead.
   BytecodeLabel after_throw, after_rethrow;
@@ -447,7 +443,7 @@ TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
 
   // Generate BytecodeArray.
   scope.SetScriptScopeInfo(factory->NewScopeInfo(1));
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> the_array = builder.ToBytecodeArray(isolate());
   CHECK_EQ(the_array->frame_size(),
            builder.total_register_count() * kSystemPointerSize);
@@ -535,7 +531,11 @@ TEST_F(BytecodeArrayBuilderTest, Parameters) {
 
   Register receiver(builder.Receiver());
   Register param8(builder.Parameter(8));
+#ifdef V8_REVERSE_JSARGS
+  CHECK_EQ(receiver.index() - param8.index(), 9);
+#else
   CHECK_EQ(param8.index() - receiver.index(), 9);
+#endif
 }
 
 TEST_F(BytecodeArrayBuilderTest, Constants) {
@@ -560,7 +560,7 @@ TEST_F(BytecodeArrayBuilderTest, Constants) {
       .LoadLiteral(nan)
       .Return();
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> array = builder.ToBytecodeArray(isolate());
   // Should only have one entry for each identical constant.
   EXPECT_EQ(4, array->constant_pool().length());
@@ -706,12 +706,14 @@ TEST_F(BytecodeArrayBuilderTest, BackwardJumps) {
   BytecodeLoopHeader loop_header;
   builder.JumpIfNull(&after_loop)
       .Bind(&loop_header)
-      .JumpLoop(&loop_header, 0)
+      .JumpLoop(&loop_header, 0, 0)
       .Bind(&after_loop);
   for (int i = 0; i < 42; i++) {
     BytecodeLabel after_loop;
     // Conditional jump to force the code after the JumpLoop to be live.
-    builder.JumpIfNull(&after_loop).JumpLoop(&loop_header, 0).Bind(&after_loop);
+    builder.JumpIfNull(&after_loop)
+        .JumpLoop(&loop_header, 0, 0)
+        .Bind(&after_loop);
   }
 
   // Add padding to force wide backwards jumps.
@@ -719,7 +721,7 @@ TEST_F(BytecodeArrayBuilderTest, BackwardJumps) {
     builder.Debugger();
   }
 
-  builder.JumpLoop(&loop_header, 0);
+  builder.JumpLoop(&loop_header, 0, 0);
   builder.Bind(&end);
   builder.Return();
 
diff --git a/deps/v8/test/unittests/interpreter/bytecode-array-iterator-unittest.cc b/deps/v8/test/unittests/interpreter/bytecode-array-iterator-unittest.cc
index 23f0d08c1c..5772b802c0 100644
--- a/deps/v8/test/unittests/interpreter/bytecode-array-iterator-unittest.cc
+++ b/deps/v8/test/unittests/interpreter/bytecode-array-iterator-unittest.cc
@@ -53,10 +53,8 @@ TEST_F(BytecodeArrayIteratorTest, IteratesBytecodeArray) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -73,7 +71,7 @@ TEST_F(BytecodeArrayIteratorTest, IteratesBytecodeArray) {
       .Return();
 
   // Test iterator sees the expected output from the builder.
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   BytecodeArrayIterator iterator(builder.ToBytecodeArray(isolate()));
   const int kPrefixByteSize = 1;
   int offset = 0;
@@ -138,14 +136,6 @@ TEST_F(BytecodeArrayIteratorTest, IteratesBytecodeArray) {
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
   iterator.Advance();
 
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  CHECK(!iterator.done());
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  iterator.Advance();
-
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
@@ -164,14 +154,6 @@ TEST_F(BytecodeArrayIteratorTest, IteratesBytecodeArray) {
             kPrefixByteSize;
   iterator.Advance();
 
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  CHECK(!iterator.done());
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  iterator.Advance();
-
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
diff --git a/deps/v8/test/unittests/interpreter/bytecode-array-random-iterator-unittest.cc b/deps/v8/test/unittests/interpreter/bytecode-array-random-iterator-unittest.cc
index 9553058d8d..ecdf6757fb 100644
--- a/deps/v8/test/unittests/interpreter/bytecode-array-random-iterator-unittest.cc
+++ b/deps/v8/test/unittests/interpreter/bytecode-array-random-iterator-unittest.cc
@@ -49,10 +49,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, InvalidBeforeStart) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -66,7 +64,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, InvalidBeforeStart) {
       .Debugger()
       .Return();
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
   BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
 
@@ -103,10 +101,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, InvalidAfterEnd) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -120,7 +116,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, InvalidAfterEnd) {
       .Debugger()
       .Return();
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
   BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
 
@@ -157,10 +153,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, AccessesFirst) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -174,7 +168,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, AccessesFirst) {
       .Debugger()
       .Return();
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
   BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
 
@@ -216,10 +210,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, AccessesLast) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -233,7 +225,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, AccessesLast) {
       .Debugger()
       .Return();
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
   BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
 
@@ -242,7 +234,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, AccessesLast) {
   int offset = bytecodeArray->length() -
                Bytecodes::Size(Bytecode::kReturn, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kReturn);
-  EXPECT_EQ(iterator.current_index(), 22);
+  EXPECT_EQ(iterator.current_index(), 20);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
@@ -276,10 +268,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -294,13 +284,13 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
       .Return();
 
   // Test iterator sees the expected output from the builder.
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   BytecodeArrayRandomIterator iterator(builder.ToBytecodeArray(isolate()),
                                        zone());
   const int kPrefixByteSize = 1;
   int offset = 0;
 
-  iterator.GoToIndex(13);
+  iterator.GoToIndex(11);
   offset = Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
@@ -308,16 +298,14 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kLdaZero, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kQuadruple) +
             kPrefixByteSize;
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kAdd);
-  EXPECT_EQ(iterator.current_index(), 13);
+  EXPECT_EQ(iterator.current_index(), 11);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -336,7 +324,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
             heap_num_1);
   ASSERT_TRUE(iterator.IsValid());
 
-  iterator.GoToIndex(18);
+  iterator.GoToIndex(16);
   offset = Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
@@ -344,11 +332,9 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kLdaZero, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kQuadruple) +
             kPrefixByteSize;
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
@@ -358,7 +344,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kCallRuntimeForPair);
-  EXPECT_EQ(iterator.current_index(), 18);
+  EXPECT_EQ(iterator.current_index(), 16);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadLookupSlotForCall);
@@ -375,7 +361,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset -= Bytecodes::Size(Bytecode::kLdaNamedProperty, OperandScale::kSingle);
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaNamedProperty);
-  EXPECT_EQ(iterator.current_index(), 15);
+  EXPECT_EQ(iterator.current_index(), 13);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -388,14 +374,14 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 17);
+  EXPECT_EQ(iterator.current_index(), 15);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), param.index());
   EXPECT_EQ(iterator.GetRegisterOperandRange(0), 1);
   ASSERT_TRUE(iterator.IsValid());
 
-  iterator.GoToIndex(22);
+  iterator.GoToIndex(20);
   offset = Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaConstant, OperandScale::kSingle);
@@ -403,11 +389,9 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kLdaZero, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kQuadruple) +
             kPrefixByteSize;
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
   offset += Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
@@ -422,12 +406,12 @@ TEST_F(BytecodeArrayRandomIteratorTest, RandomAccessValid) {
   offset += Bytecodes::Size(Bytecode::kDebugger, OperandScale::kSingle);
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kReturn);
-  EXPECT_EQ(iterator.current_index(), 22);
+  EXPECT_EQ(iterator.current_index(), 20);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
 
-  iterator.GoToIndex(24);
+  iterator.GoToIndex(22);
   EXPECT_FALSE(iterator.IsValid());
 
   iterator.GoToIndex(-5);
@@ -462,10 +446,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -480,7 +462,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
       .Return();
 
   // Test iterator sees the expected output from the builder.
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   BytecodeArrayRandomIterator iterator(builder.ToBytecodeArray(isolate()),
                                        zone());
   const int kPrefixByteSize = 1;
@@ -553,17 +535,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   offset += Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
   ++iterator;
 
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_index(), 7);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  ASSERT_TRUE(iterator.IsValid());
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  ++iterator;
-
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 8);
+  EXPECT_EQ(iterator.current_index(), 7);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -573,7 +546,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaSmi);
-  EXPECT_EQ(iterator.current_index(), 9);
+  EXPECT_EQ(iterator.current_index(), 8);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kQuadruple);
   EXPECT_EQ(Smi::FromInt(iterator.GetImmediateOperand(0)), smi_1);
@@ -582,17 +555,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
             kPrefixByteSize;
   ++iterator;
 
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_index(), 10);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  ASSERT_TRUE(iterator.IsValid());
-  offset += Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  ++iterator;
-
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 11);
+  EXPECT_EQ(iterator.current_index(), 9);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -602,7 +566,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdar);
-  EXPECT_EQ(iterator.current_index(), 12);
+  EXPECT_EQ(iterator.current_index(), 10);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -611,7 +575,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kAdd);
-  EXPECT_EQ(iterator.current_index(), 13);
+  EXPECT_EQ(iterator.current_index(), 11);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -621,7 +585,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 14);
+  EXPECT_EQ(iterator.current_index(), 12);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -631,7 +595,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaNamedProperty);
-  EXPECT_EQ(iterator.current_index(), 15);
+  EXPECT_EQ(iterator.current_index(), 13);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -642,7 +606,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kAdd);
-  EXPECT_EQ(iterator.current_index(), 16);
+  EXPECT_EQ(iterator.current_index(), 14);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -652,7 +616,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 17);
+  EXPECT_EQ(iterator.current_index(), 15);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), param.index());
@@ -662,7 +626,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kCallRuntimeForPair);
-  EXPECT_EQ(iterator.current_index(), 18);
+  EXPECT_EQ(iterator.current_index(), 16);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadLookupSlotForCall);
@@ -677,7 +641,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kForInPrepare);
-  EXPECT_EQ(iterator.current_index(), 19);
+  EXPECT_EQ(iterator.current_index(), 17);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -688,7 +652,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kCallRuntime);
-  EXPECT_EQ(iterator.current_index(), 20);
+  EXPECT_EQ(iterator.current_index(), 18);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadIC_Miss);
@@ -699,7 +663,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kDebugger);
-  EXPECT_EQ(iterator.current_index(), 21);
+  EXPECT_EQ(iterator.current_index(), 19);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
@@ -707,7 +671,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArray) {
   ++iterator;
 
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kReturn);
-  EXPECT_EQ(iterator.current_index(), 22);
+  EXPECT_EQ(iterator.current_index(), 20);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
@@ -743,10 +707,8 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
-      .StackCheck(0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
-      .StackCheck(1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
       .BinaryOperation(Token::Value::ADD, reg_0, 2)
@@ -761,7 +723,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
       .Return();
 
   // Test iterator sees the expected output from the builder.
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<BytecodeArray> bytecodeArray = builder.ToBytecodeArray(isolate());
   BytecodeArrayRandomIterator iterator(bytecodeArray, zone());
   const int kPrefixByteSize = 1;
@@ -771,7 +733,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kReturn, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kReturn);
-  EXPECT_EQ(iterator.current_index(), 22);
+  EXPECT_EQ(iterator.current_index(), 20);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
@@ -779,7 +741,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kDebugger, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kDebugger);
-  EXPECT_EQ(iterator.current_index(), 21);
+  EXPECT_EQ(iterator.current_index(), 19);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   ASSERT_TRUE(iterator.IsValid());
@@ -787,7 +749,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kCallRuntime, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kCallRuntime);
-  EXPECT_EQ(iterator.current_index(), 20);
+  EXPECT_EQ(iterator.current_index(), 18);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadIC_Miss);
@@ -798,7 +760,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kForInPrepare, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kForInPrepare);
-  EXPECT_EQ(iterator.current_index(), 19);
+  EXPECT_EQ(iterator.current_index(), 17);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -810,7 +772,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
   offset -=
       Bytecodes::Size(Bytecode::kCallRuntimeForPair, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kCallRuntimeForPair);
-  EXPECT_EQ(iterator.current_index(), 18);
+  EXPECT_EQ(iterator.current_index(), 16);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRuntimeIdOperand(0), Runtime::kLoadLookupSlotForCall);
@@ -824,7 +786,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 17);
+  EXPECT_EQ(iterator.current_index(), 15);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), param.index());
@@ -834,7 +796,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kAdd);
-  EXPECT_EQ(iterator.current_index(), 16);
+  EXPECT_EQ(iterator.current_index(), 14);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -844,7 +806,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kLdaNamedProperty, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaNamedProperty);
-  EXPECT_EQ(iterator.current_index(), 15);
+  EXPECT_EQ(iterator.current_index(), 13);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -855,7 +817,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 14);
+  EXPECT_EQ(iterator.current_index(), 12);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -865,7 +827,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kAdd, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kAdd);
-  EXPECT_EQ(iterator.current_index(), 13);
+  EXPECT_EQ(iterator.current_index(), 11);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -875,7 +837,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdar);
-  EXPECT_EQ(iterator.current_index(), 12);
+  EXPECT_EQ(iterator.current_index(), 10);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -884,7 +846,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 11);
+  EXPECT_EQ(iterator.current_index(), 9);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
@@ -892,19 +854,10 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
   ASSERT_TRUE(iterator.IsValid());
   --iterator;
 
-  offset -= Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_index(), 10);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  ASSERT_TRUE(iterator.IsValid());
-  --iterator;
-
   offset -= Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kQuadruple) +
             kPrefixByteSize;
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaSmi);
-  EXPECT_EQ(iterator.current_index(), 9);
+  EXPECT_EQ(iterator.current_index(), 8);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kQuadruple);
   EXPECT_EQ(Smi::FromInt(iterator.GetImmediateOperand(0)), smi_1);
@@ -913,7 +866,7 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
 
   offset -= Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStar);
-  EXPECT_EQ(iterator.current_index(), 8);
+  EXPECT_EQ(iterator.current_index(), 7);
   EXPECT_EQ(iterator.current_offset(), offset);
   EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   EXPECT_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
@@ -921,15 +874,6 @@ TEST_F(BytecodeArrayRandomIteratorTest, IteratesBytecodeArrayBackwards) {
   ASSERT_TRUE(iterator.IsValid());
   --iterator;
 
-  offset -= Bytecodes::Size(Bytecode::kStackCheck, OperandScale::kSingle);
-  EXPECT_EQ(iterator.current_bytecode(), Bytecode::kStackCheck);
-  EXPECT_EQ(iterator.current_index(), 7);
-  EXPECT_EQ(iterator.current_offset(), offset);
-  EXPECT_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
-  EXPECT_EQ(Bytecodes::NumberOfOperands(iterator.current_bytecode()), 0);
-  ASSERT_TRUE(iterator.IsValid());
-  --iterator;
-
   offset -= Bytecodes::Size(Bytecode::kLdaSmi, OperandScale::kSingle);
   EXPECT_EQ(iterator.current_bytecode(), Bytecode::kLdaSmi);
   EXPECT_EQ(iterator.current_index(), 6);
diff --git a/deps/v8/test/unittests/interpreter/bytecode-array-writer-unittest.cc b/deps/v8/test/unittests/interpreter/bytecode-array-writer-unittest.cc
index 339fc33178..0bf431eaae 100644
--- a/deps/v8/test/unittests/interpreter/bytecode-array-writer-unittest.cc
+++ b/deps/v8/test/unittests/interpreter/bytecode-array-writer-unittest.cc
@@ -115,28 +115,24 @@ void BytecodeArrayWriterUnittest::WriteJumpLoop(Bytecode bytecode,
 TEST_F(BytecodeArrayWriterUnittest, SimpleExample) {
   CHECK_EQ(bytecodes()->size(), 0u);
 
-  Write(Bytecode::kStackCheck, {10, false});
-  CHECK_EQ(bytecodes()->size(), 1u);
-
   Write(Bytecode::kLdaSmi, 127, {55, true});
-  CHECK_EQ(bytecodes()->size(), 3u);
+  CHECK_EQ(bytecodes()->size(), 2u);
 
   Write(Bytecode::kStar, Register(20).ToOperand());
-  CHECK_EQ(bytecodes()->size(), 5u);
+  CHECK_EQ(bytecodes()->size(), 4u);
 
   Write(Bytecode::kLdar, Register(200).ToOperand());
-  CHECK_EQ(bytecodes()->size(), 9u);
+  CHECK_EQ(bytecodes()->size(), 8u);
 
   Write(Bytecode::kReturn, {70, true});
-  CHECK_EQ(bytecodes()->size(), 10u);
+  CHECK_EQ(bytecodes()->size(), 9u);
 
   static const uint8_t expected_bytes[] = {
       // clang-format off
-      /*  0 10 E> */ B(StackCheck),
-      /*  1 55 S> */ B(LdaSmi), U8(127),
-      /*  3       */ B(Star), R8(20),
-      /*  5       */ B(Wide), B(Ldar), R16(200),
-      /*  9 70 S> */ B(Return),
+      /*  0 55 S> */ B(LdaSmi), U8(127),
+      /*  2       */ B(Star), R8(20),
+      /*  4       */ B(Wide), B(Ldar), R16(200),
+      /*  8 70 S> */ B(Return),
       // clang-format on
   };
   CHECK_EQ(bytecodes()->size(), arraysize(expected_bytes));
@@ -150,8 +146,7 @@ TEST_F(BytecodeArrayWriterUnittest, SimpleExample) {
       *writer()->ToSourcePositionTable(isolate()));
   CHECK_EQ(bytecodes()->size(), arraysize(expected_bytes));
 
-  PositionTableEntry expected_positions[] = {
-      {0, 10, false}, {1, 55, true}, {9, 70, true}};
+  PositionTableEntry expected_positions[] = {{0, 55, true}, {8, 70, true}};
   SourcePositionTableIterator source_iterator(
       bytecode_array->SourcePositionTable());
   for (size_t i = 0; i < arraysize(expected_positions); ++i) {
@@ -168,40 +163,37 @@ TEST_F(BytecodeArrayWriterUnittest, SimpleExample) {
 TEST_F(BytecodeArrayWriterUnittest, ComplexExample) {
   static const uint8_t expected_bytes[] = {
       // clang-format off
-      /*  0 30 E> */ B(StackCheck),
-      /*  1 42 S> */ B(LdaConstant), U8(0),
-      /*  3 42 E> */ B(Add), R8(1), U8(1),
-      /*  5 68 S> */ B(JumpIfUndefined), U8(39),
-      /*  7       */ B(JumpIfNull), U8(37),
-      /*  9       */ B(ToObject), R8(3),
-      /* 11       */ B(ForInPrepare), R8(3), U8(4),
-      /* 14       */ B(LdaZero),
-      /* 15       */ B(Star), R8(7),
-      /* 17 63 S> */ B(ForInContinue), R8(7), R8(6),
-      /* 20       */ B(JumpIfFalse), U8(24),
-      /* 22       */ B(ForInNext), R8(3), R8(7), R8(4), U8(1),
-      /* 27       */ B(JumpIfUndefined), U8(10),
-      /* 29       */ B(Star), R8(0),
-      /* 31 54 E> */ B(StackCheck),
-      /* 32       */ B(Ldar), R8(0),
-      /* 34       */ B(Star), R8(2),
-      /* 36 85 S> */ B(Return),
-      /* 37       */ B(ForInStep), R8(7),
-      /* 39       */ B(Star), R8(7),
-      /* 41       */ B(JumpLoop), U8(24), U8(0),
-      /* 44       */ B(LdaUndefined),
-      /* 45 85 S> */ B(Return),
+      /*  0 42 S> */ B(LdaConstant), U8(0),
+      /*  2 42 E> */ B(Add), R8(1), U8(1),
+      /*  4 68 S> */ B(JumpIfUndefined), U8(38),
+      /*  6       */ B(JumpIfNull), U8(36),
+      /*  8       */ B(ToObject), R8(3),
+      /* 10       */ B(ForInPrepare), R8(3), U8(4),
+      /* 13       */ B(LdaZero),
+      /* 14       */ B(Star), R8(7),
+      /* 16 63 S> */ B(ForInContinue), R8(7), R8(6),
+      /* 19       */ B(JumpIfFalse), U8(23),
+      /* 21       */ B(ForInNext), R8(3), R8(7), R8(4), U8(1),
+      /* 26       */ B(JumpIfUndefined), U8(9),
+      /* 28       */ B(Star), R8(0),
+      /* 30       */ B(Ldar), R8(0),
+      /* 32       */ B(Star), R8(2),
+      /* 34 85 S> */ B(Return),
+      /* 35       */ B(ForInStep), R8(7),
+      /* 37       */ B(Star), R8(7),
+      /* 39       */ B(JumpLoop), U8(23), U8(0),
+      /* 42       */ B(LdaUndefined),
+      /* 43 85 S> */ B(Return),
       // clang-format on
   };
 
   static const PositionTableEntry expected_positions[] = {
-      {0, 30, false}, {1, 42, true},   {3, 42, false}, {6, 68, true},
-      {18, 63, true}, {32, 54, false}, {37, 85, true}, {46, 85, true}};
+      {0, 42, true},  {2, 42, false}, {5, 68, true},
+      {17, 63, true}, {35, 85, true}, {44, 85, true}};
 
   BytecodeLoopHeader loop_header;
   BytecodeLabel jump_for_in, jump_end_1, jump_end_2, jump_end_3;
 
-  Write(Bytecode::kStackCheck, {30, false});
   Write(Bytecode::kLdaConstant, U8(0), {42, true});
   Write(Bytecode::kAdd, R(1), U8(1), {42, false});
   WriteJump(Bytecode::kJumpIfUndefined, &jump_end_1, {68, true});
@@ -216,7 +208,6 @@ TEST_F(BytecodeArrayWriterUnittest, ComplexExample) {
   Write(Bytecode::kForInNext, R(3), R(7), R(4), U8(1));
   WriteJump(Bytecode::kJumpIfUndefined, &jump_for_in);
   Write(Bytecode::kStar, R(0));
-  Write(Bytecode::kStackCheck, {54, false});
   Write(Bytecode::kLdar, R(0));
   Write(Bytecode::kStar, R(2));
   Write(Bytecode::kReturn, {85, true});
@@ -258,23 +249,18 @@ TEST_F(BytecodeArrayWriterUnittest, ElideNoneffectfulBytecodes) {
 
   static const uint8_t expected_bytes[] = {
       // clang-format off
-      /*  0  10 E> */ B(StackCheck),
-      /*  1  55 S> */ B(Ldar), R8(20),
-      /*  3        */ B(Star), R8(20),
-      /*  5        */ B(CreateMappedArguments),
-      /*  6  60 S> */ B(LdaSmi), U8(127),
-      /*  8  70 S> */ B(Ldar), R8(20),
-      /*  10 75 S> */ B(Return),
+      /*  0  55 S> */ B(Ldar), R8(20),
+      /*  2        */ B(Star), R8(20),
+      /*  4        */ B(CreateMappedArguments),
+      /*  5  60 S> */ B(LdaSmi), U8(127),
+      /*  7  70 S> */ B(Ldar), R8(20),
+      /*  9 75 S> */ B(Return),
       // clang-format on
   };
 
-  static const PositionTableEntry expected_positions[] = {{0, 10, false},
-                                                          {1, 55, true},
-                                                          {6, 60, false},
-                                                          {8, 70, true},
-                                                          {10, 75, true}};
+  static const PositionTableEntry expected_positions[] = {
+      {0, 55, true}, {5, 60, false}, {7, 70, true}, {9, 75, true}};
 
-  Write(Bytecode::kStackCheck, {10, false});
   Write(Bytecode::kLdaSmi, 127, {55, true});  // Should be elided.
   Write(Bytecode::kLdar, Register(20).ToOperand());
   Write(Bytecode::kStar, Register(20).ToOperand());
@@ -310,27 +296,25 @@ TEST_F(BytecodeArrayWriterUnittest, ElideNoneffectfulBytecodes) {
 TEST_F(BytecodeArrayWriterUnittest, DeadcodeElimination) {
   static const uint8_t expected_bytes[] = {
       // clang-format off
-      /*  0  10 E> */ B(StackCheck),
-      /*  1  55 S> */ B(LdaSmi), U8(127),
-      /*  3        */ B(Jump), U8(2),
-      /*  5  65 S> */ B(LdaSmi), U8(127),
-      /*  7        */ B(JumpIfFalse), U8(3),
-      /*  9  75 S> */ B(Return),
-      /*  10       */ B(JumpIfFalse), U8(3),
-      /*  12       */ B(Throw),
-      /*  13       */ B(JumpIfFalse), U8(3),
-      /*  15       */ B(ReThrow),
-      /*  16       */ B(Return),
+      /*  0  55 S> */ B(LdaSmi), U8(127),
+      /*  2        */ B(Jump), U8(2),
+      /*  4  65 S> */ B(LdaSmi), U8(127),
+      /*  6        */ B(JumpIfFalse), U8(3),
+      /*  8  75 S> */ B(Return),
+      /*  9       */ B(JumpIfFalse), U8(3),
+      /*  11       */ B(Throw),
+      /*  12       */ B(JumpIfFalse), U8(3),
+      /*  14       */ B(ReThrow),
+      /*  15       */ B(Return),
       // clang-format on
   };
 
   static const PositionTableEntry expected_positions[] = {
-      {0, 10, false}, {1, 55, true}, {5, 65, true}, {9, 75, true}};
+      {0, 55, true}, {4, 65, true}, {8, 75, true}};
 
   BytecodeLabel after_jump, after_conditional_jump, after_return, after_throw,
       after_rethrow;
 
-  Write(Bytecode::kStackCheck, {10, false});
   Write(Bytecode::kLdaSmi, 127, {55, true});
   WriteJump(Bytecode::kJump, &after_jump);
   Write(Bytecode::kLdaSmi, 127);                               // Dead code.
diff --git a/deps/v8/test/unittests/interpreter/constant-array-builder-unittest.cc b/deps/v8/test/unittests/interpreter/constant-array-builder-unittest.cc
index 680479754a..bfe83b03ca 100644
--- a/deps/v8/test/unittests/interpreter/constant-array-builder-unittest.cc
+++ b/deps/v8/test/unittests/interpreter/constant-array-builder-unittest.cc
@@ -40,7 +40,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateAllEntries) {
     builder.Insert(i + 0.5);
   }
   CHECK_EQ(builder.size(), k16BitCapacity);
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   for (size_t i = 0; i < k16BitCapacity; i++) {
     CHECK_EQ(
         Handle<HeapNumber>::cast(builder.At(i, isolate()).ToHandleChecked())
@@ -90,7 +90,7 @@ TEST_F(ConstantArrayBuilderTest, ToLargeFixedArrayWithReservations) {
   for (int i = 0; i < kNumberOfElements; i++) {
     builder.CommitReservedEntry(builder.CreateReservedEntry(), Smi::FromInt(i));
   }
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
   ASSERT_EQ(kNumberOfElements, constant_array->length());
   for (int i = 0; i < kNumberOfElements; i++) {
@@ -149,7 +149,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithIdx8Reservations) {
       builder.DiscardReservedEntry(OperandSize::kByte);
     }
 
-    ast_factory.Internalize(isolate()->factory());
+    ast_factory.Internalize(isolate());
     Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
     CHECK_EQ(constant_array->length(),
              static_cast<int>(2 * k8BitCapacity + reserved));
@@ -203,7 +203,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithWideReservations) {
       CHECK_EQ(builder.size(), i + 1);
     }
 
-    ast_factory.Internalize(isolate()->factory());
+    ast_factory.Internalize(isolate());
     Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
     CHECK_EQ(constant_array->length(),
              static_cast<int>(k8BitCapacity + reserved));
@@ -234,7 +234,7 @@ TEST_F(ConstantArrayBuilderTest, GapFilledWhenLowReservationCommitted) {
                                 Smi::FromInt(static_cast<int>(i)));
     CHECK_EQ(builder.size(), 2 * k8BitCapacity);
   }
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
   CHECK_EQ(constant_array->length(), static_cast<int>(2 * k8BitCapacity));
   for (size_t i = 0; i < k8BitCapacity; i++) {
@@ -300,7 +300,7 @@ TEST_F(ConstantArrayBuilderTest, HolesWithUnusedReservations) {
     builder.DiscardReservedEntry(OperandSize::kByte);
   }
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
   CHECK_EQ(constant_array->length(), k8BitCapacity + 1);
   for (int i = kNumberOfHoles; i < k8BitCapacity; i++) {
@@ -343,7 +343,7 @@ TEST_F(ConstantArrayBuilderTest, ReservationsAtAllScales) {
     builder.DiscardReservedEntry(OperandSize::kQuad);
   }
 
-  ast_factory.Internalize(isolate()->factory());
+  ast_factory.Internalize(isolate());
   Handle<FixedArray> constant_array = builder.ToFixedArray(isolate());
   CHECK_EQ(constant_array->length(), 65537);
   int count = 1;
diff --git a/deps/v8/test/unittests/objects/value-serializer-unittest.cc b/deps/v8/test/unittests/objects/value-serializer-unittest.cc
index fac266d3f9..59d9b4df78 100644
--- a/deps/v8/test/unittests/objects/value-serializer-unittest.cc
+++ b/deps/v8/test/unittests/objects/value-serializer-unittest.cc
@@ -235,8 +235,7 @@ class ValueSerializerTest : public TestWithIsolate {
   }
 
   Local<String> StringFromUtf8(const char* source) {
-    return String::NewFromUtf8(isolate(), source, NewStringType::kNormal)
-        .ToLocalChecked();
+    return String::NewFromUtf8(isolate(), source).ToLocalChecked();
   }
 
   std::string Utf8Value(Local<Value> value) {
@@ -2500,10 +2499,8 @@ class ValueSerializerTestWithWasm : public ValueSerializerTest {
     Maybe<uint32_t> GetWasmModuleTransferId(
         Isolate* isolate, Local<WasmModuleObject> module) override {
       isolate->ThrowException(Exception::Error(
-          String::NewFromOneByte(
-              isolate,
-              reinterpret_cast<const uint8_t*>(kUnsupportedSerialization),
-              NewStringType::kNormal)
+          String::NewFromOneByte(isolate, reinterpret_cast<const uint8_t*>(
+                                              kUnsupportedSerialization))
               .ToLocalChecked()));
       return Nothing<uint32_t>();
     }
diff --git a/deps/v8/test/unittests/profiler/strings-storage-unittest.cc b/deps/v8/test/unittests/profiler/strings-storage-unittest.cc
index 31225f46c2..087a7bf735 100644
--- a/deps/v8/test/unittests/profiler/strings-storage-unittest.cc
+++ b/deps/v8/test/unittests/profiler/strings-storage-unittest.cc
@@ -108,5 +108,54 @@ TEST_F(StringsStorageWithIsolate, FormatAndGetShareStorage) {
   CHECK_EQ(stored_str, formatted_str);
 }
 
+TEST_F(StringsStorageWithIsolate, Refcounting) {
+  StringsStorage storage;
+
+  const char* a = storage.GetCopy("12");
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+
+  const char* b = storage.GetCopy("12");
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+
+  // Ensure that we deduplicate the string.
+  CHECK_EQ(a, b);
+
+  CHECK(storage.Release(a));
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+  CHECK(storage.Release(b));
+  CHECK_EQ(storage.GetStringCountForTesting(), 0);
+#if !DEBUG
+  CHECK(!storage.Release("12"));
+#endif  // !DEBUG
+
+  // Verify that other constructors refcount as intended.
+  const char* c = storage.GetFormatted("%d", 12);
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+
+  const char* d = storage.GetName(12);
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+
+  CHECK_EQ(c, d);
+
+  CHECK(storage.Release(c));
+  CHECK_EQ(storage.GetStringCountForTesting(), 1);
+  CHECK(storage.Release(d));
+  CHECK_EQ(storage.GetStringCountForTesting(), 0);
+#if !DEBUG
+  CHECK(!storage.Release("12"));
+#endif  // !DEBUG
+}
+
+TEST_F(StringsStorageWithIsolate, InvalidRelease) {
+  StringsStorage storage;
+
+  // If a refcount becomes invalid, throw in debug builds.
+#ifdef DEBUG
+  ASSERT_DEATH_IF_SUPPORTED(storage.Release("12"), "check failed");
+#else
+  CHECK(!storage.Release("12"));
+#endif  // DEBUG
+}
+
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/unittests/test-utils.h b/deps/v8/test/unittests/test-utils.h
index 3746ee267e..c2ffbf1561 100644
--- a/deps/v8/test/unittests/test-utils.h
+++ b/deps/v8/test/unittests/test-utils.h
@@ -181,9 +181,8 @@ class WithContextMixin : public TMixin {
   const Local<Context>& v8_context() const { return context_; }
 
   Local<Value> RunJS(const char* source) {
-    return RunJS(v8::String::NewFromUtf8(v8_isolate(), source,
-                                         v8::NewStringType::kNormal)
-                     .ToLocalChecked());
+    return RunJS(
+        v8::String::NewFromUtf8(v8_isolate(), source).ToLocalChecked());
   }
 
   Local<Value> RunJS(v8::String::ExternalOneByteStringResource* source) {
@@ -192,9 +191,7 @@ class WithContextMixin : public TMixin {
   }
 
   v8::Local<v8::String> NewString(const char* string) {
-    return v8::String::NewFromUtf8(v8_isolate(), string,
-                                   v8::NewStringType::kNormal)
-        .ToLocalChecked();
+    return v8::String::NewFromUtf8(v8_isolate(), string).ToLocalChecked();
   }
 
   void SetGlobalProperty(const char* name, v8::Local<v8::Value> value) {
diff --git a/deps/v8/test/unittests/torque/torque-unittest.cc b/deps/v8/test/unittests/torque/torque-unittest.cc
index 5180e301cc..778efc7641 100644
--- a/deps/v8/test/unittests/torque/torque-unittest.cc
+++ b/deps/v8/test/unittests/torque/torque-unittest.cc
@@ -25,6 +25,9 @@ namespace torque_internal {
     const object: HeapObject;
     const offset: intptr;
   }
+  type ConstReference<T : type> extends Reference<T>;
+  type MutableReference<T : type> extends ConstReference<T>;
+
   type UninitializedHeapObject extends HeapObject;
 }
 
@@ -42,6 +45,7 @@ extern class HeapObject extends StrongTagged {
 }
 type Map extends HeapObject generates 'TNode<Map>';
 type Object = Smi | HeapObject;
+type Number = Smi|HeapNumber;
 type JSReceiver extends HeapObject generates 'TNode<JSReceiver>';
 type JSObject extends JSReceiver generates 'TNode<JSObject>';
 type int32 generates 'TNode<Int32T>' constexpr 'int32_t';
@@ -70,12 +74,18 @@ type Code extends HeapObject generates 'TNode<Code>';
 type BuiltinPtr extends Smi generates 'TNode<BuiltinPtr>';
 type Context extends HeapObject generates 'TNode<Context>';
 type NativeContext extends Context;
+type SmiTagged<T : type extends uint31> extends Smi;
+type String extends HeapObject;
+type HeapNumber extends HeapObject;
+type FixedArrayBase extends HeapObject;
 
 struct float64_or_hole {
   is_hole: bool;
   value: float64;
 }
 
+extern operator '+' macro IntPtrAdd(intptr, intptr): intptr;
+
 intrinsic %FromConstexpr<To: type, From: type>(b: From): To;
 intrinsic %RawDownCast<To: type, From: type>(x: From): To;
 intrinsic %RawConstexprCast<To: type, From: type>(f: From): To;
@@ -84,6 +94,7 @@ extern macro TaggedToSmi(Object): Smi
     labels CastError;
 extern macro TaggedToHeapObject(Object): HeapObject
     labels CastError;
+extern macro Float64SilenceNaN(float64): float64;
 
 extern macro IntPtrConstant(constexpr int31): intptr;
 
@@ -97,6 +108,9 @@ FromConstexpr<Smi, constexpr int31>(s: constexpr int31): Smi {
 FromConstexpr<intptr, constexpr int31>(i: constexpr int31): intptr {
   return IntPtrConstant(i);
 }
+FromConstexpr<intptr, constexpr intptr>(i: constexpr intptr): intptr {
+  return %FromConstexpr<intptr>(i);
+}
 
 macro Cast<A : type extends Object>(implicit context: Context)(o: Object): A
     labels CastError {
@@ -613,6 +627,134 @@ TEST(Torque, EnumInTypeswitch) {
   )");
 }
 
+TEST(Torque, ConstClassFields) {
+  ExpectSuccessfulCompilation(R"(
+    class Foo extends HeapObject {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      const _x: int32 = o.x;
+      o.y = n;
+    }
+  )");
+
+  ExpectFailingCompilation(R"(
+    class Foo extends HeapObject {
+      const x: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      o.x = n;
+    }
+  )",
+                           HasSubstr("cannot assign to const value"));
+
+  ExpectSuccessfulCompilation(R"(
+    class Foo extends HeapObject {
+      s: Bar;
+    }
+    struct Bar {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      const _x: int32 = o.s.x;
+      // Assigning a struct as a value is OK, even when the struct contains
+      // const fields.
+      o.s = Bar{x: n, y: n};
+      o.s.y = n;
+    }
+  )");
+
+  ExpectFailingCompilation(R"(
+    class Foo extends HeapObject {
+      const s: Bar;
+    }
+    struct Bar {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      o.s.y = n;
+    }
+  )",
+                           HasSubstr("cannot assign to const value"));
+
+  ExpectFailingCompilation(R"(
+    class Foo extends HeapObject {
+      s: Bar;
+    }
+    struct Bar {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      o.s.x = n;
+    }
+  )",
+                           HasSubstr("cannot assign to const value"));
+}
+
+TEST(Torque, References) {
+  ExpectSuccessfulCompilation(R"(
+    class Foo extends HeapObject {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      const constRefX: const &int32 = &o.x;
+      const refY: &int32 = &o.y;
+      const constRefY: const &int32 = refY;
+      const _x: int32 = *constRefX;
+      const _y1: int32 = *refY;
+      const _y2: int32 = *constRefY;
+      *refY = n;
+      let r: const &int32 = constRefX;
+      r = constRefY;
+    }
+  )");
+
+  ExpectFailingCompilation(R"(
+    class Foo extends HeapObject {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo) {
+      const _refX: &int32 = &o.x;
+    }
+  )",
+                           HasSubstr("cannot use expression of type const "
+                                     "&int32 as a value of type &int32"));
+
+  ExpectFailingCompilation(R"(
+    class Foo extends HeapObject {
+      const x: int32;
+      y: int32;
+    }
+
+    @export
+    macro Test(implicit context: Context)(o: Foo, n: int32) {
+      const constRefX: const &int32 = &o.x;
+      *constRefX = n;
+    }
+  )",
+                           HasSubstr("cannot assign to const value"));
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8
diff --git a/deps/v8/test/unittests/wasm/function-body-decoder-unittest.cc b/deps/v8/test/unittests/wasm/function-body-decoder-unittest.cc
index de3f825335..e242132a14 100644
--- a/deps/v8/test/unittests/wasm/function-body-decoder-unittest.cc
+++ b/deps/v8/test/unittests/wasm/function-body-decoder-unittest.cc
@@ -109,7 +109,7 @@ class FunctionBodyDecoderTest : public TestWithZone {
   // Prepends local variable declarations and renders nice error messages for
   // verification failures.
   template <typename Code = std::initializer_list<const byte>>
-  void Validate(bool expected_success, FunctionSig* sig, Code&& raw_code,
+  void Validate(bool expected_success, const FunctionSig* sig, Code&& raw_code,
                 AppendEnd append_end = kAppendEnd,
                 const char* message = nullptr) {
     Vector<const byte> code =
@@ -136,20 +136,20 @@ class FunctionBodyDecoderTest : public TestWithZone {
   }
 
   template <typename Code = std::initializer_list<const byte>>
-  void ExpectValidates(FunctionSig* sig, Code&& raw_code,
+  void ExpectValidates(const FunctionSig* sig, Code&& raw_code,
                        AppendEnd append_end = kAppendEnd,
                        const char* message = nullptr) {
     Validate(true, sig, std::forward<Code>(raw_code), append_end, message);
   }
 
   template <typename Code = std::initializer_list<const byte>>
-  void ExpectFailure(FunctionSig* sig, Code&& raw_code,
+  void ExpectFailure(const FunctionSig* sig, Code&& raw_code,
                      AppendEnd append_end = kAppendEnd,
                      const char* message = nullptr) {
     Validate(false, sig, std::forward<Code>(raw_code), append_end, message);
   }
 
-  void TestBinop(WasmOpcode opcode, FunctionSig* success) {
+  void TestBinop(WasmOpcode opcode, const FunctionSig* success) {
     // op(local[0], local[1])
     byte code[] = {WASM_BINOP(opcode, WASM_GET_LOCAL(0), WASM_GET_LOCAL(1))};
     ExpectValidates(success, code);
@@ -171,7 +171,7 @@ class FunctionBodyDecoderTest : public TestWithZone {
     }
   }
 
-  void TestUnop(WasmOpcode opcode, FunctionSig* success) {
+  void TestUnop(WasmOpcode opcode, const FunctionSig* success) {
     TestUnop(opcode, success->GetReturn(), success->GetParam(0));
   }
 
@@ -215,22 +215,23 @@ class TestModuleBuilder {
     CHECK_LE(mod.globals.size(), kMaxByteSizedLeb128);
     return static_cast<byte>(mod.globals.size() - 1);
   }
-  byte AddSignature(FunctionSig* sig) {
+  byte AddSignature(const FunctionSig* sig) {
     mod.signatures.push_back(sig);
     CHECK_LE(mod.signatures.size(), kMaxByteSizedLeb128);
     return static_cast<byte>(mod.signatures.size() - 1);
   }
-  byte AddFunction(FunctionSig* sig) {
-    mod.functions.push_back({sig,      // sig
-                             0,        // func_index
-                             0,        // sig_index
-                             {0, 0},   // code
-                             false,    // import
-                             false});  // export
+  byte AddFunction(const FunctionSig* sig, bool declared = true) {
+    mod.functions.push_back({sig,         // sig
+                             0,           // func_index
+                             0,           // sig_index
+                             {0, 0},      // code
+                             false,       // import
+                             false,       // export
+                             declared});  // declared
     CHECK_LE(mod.functions.size(), kMaxByteSizedLeb128);
     return static_cast<byte>(mod.functions.size() - 1);
   }
-  byte AddImport(FunctionSig* sig) {
+  byte AddImport(const FunctionSig* sig) {
     byte result = AddFunction(sig);
     mod.functions[result].imported = true;
     return result;
@@ -259,11 +260,16 @@ class TestModuleBuilder {
     mod.maximum_pages = 100;
   }
 
-  void InitializeTable() { mod.tables.emplace_back(); }
+  byte InitializeTable(wasm::ValueType type) {
+    mod.tables.emplace_back();
+    mod.tables.back().type = type;
+    return static_cast<byte>(mod.tables.size() - 1);
+  }
 
-  byte AddPassiveElementSegment() {
-    mod.elem_segments.emplace_back();
+  byte AddPassiveElementSegment(wasm::ValueType type) {
+    mod.elem_segments.emplace_back(false);
     auto& init = mod.elem_segments.back();
+    init.type = type;
     // Add 5 empty elements.
     for (uint32_t j = 0; j < 5; j++) {
       init.entries.push_back(WasmElemSegment::kNullIndex);
@@ -271,6 +277,12 @@ class TestModuleBuilder {
     return static_cast<byte>(mod.elem_segments.size() - 1);
   }
 
+  byte AddDeclarativeElementSegment() {
+    mod.elem_segments.emplace_back(true);
+    mod.elem_segments.back().entries.push_back(WasmElemSegment::kNullIndex);
+    return static_cast<byte>(mod.elem_segments.size() - 1);
+  }
+
   // Set the number of data segments as declared by the DataCount section.
   void SetDataSegmentCount(uint32_t data_segment_count) {
     // The Data section occurs after the Code section, so we don't need to
@@ -387,10 +399,8 @@ TEST_F(FunctionBodyDecoderTest, TooManyLocals) {
 }
 
 TEST_F(FunctionBodyDecoderTest, GetLocal0_param_n) {
-  FunctionSig* array[] = {sigs.i_i(), sigs.i_ii(), sigs.i_iii()};
-
-  for (size_t i = 0; i < arraysize(array); i++) {
-    ExpectValidates(array[i], kCodeGetLocal0);
+  for (const FunctionSig* sig : {sigs.i_i(), sigs.i_ii(), sigs.i_iii()}) {
+    ExpectValidates(sig, kCodeGetLocal0);
   }
 }
 
@@ -1350,14 +1360,14 @@ TEST_F(FunctionBodyDecoderTest, MacrosInt64) {
 TEST_F(FunctionBodyDecoderTest, AllSimpleExpressions) {
   WASM_FEATURE_SCOPE(anyref);
 // Test all simple expressions which are described by a signature.
-#define DECODE_TEST(name, opcode, sig)                      \
-  {                                                         \
-    FunctionSig* sig = WasmOpcodes::Signature(kExpr##name); \
-    if (sig->parameter_count() == 1) {                      \
-      TestUnop(kExpr##name, sig);                           \
-    } else {                                                \
-      TestBinop(kExpr##name, sig);                          \
-    }                                                       \
+#define DECODE_TEST(name, opcode, sig)                            \
+  {                                                               \
+    const FunctionSig* sig = WasmOpcodes::Signature(kExpr##name); \
+    if (sig->parameter_count() == 1) {                            \
+      TestUnop(kExpr##name, sig);                                 \
+    } else {                                                      \
+      TestBinop(kExpr##name, sig);                                \
+    }                                                             \
   }
 
   FOREACH_SIMPLE_OPCODE(DECODE_TEST);
@@ -1475,7 +1485,7 @@ TEST_F(FunctionBodyDecoderTest, AllLoadMemCombinations) {
       MachineType mem_type = machineTypes[j];
       byte code[] = {WASM_LOAD_MEM(mem_type, WASM_ZERO)};
       FunctionSig sig(1, 0, &local_type);
-      Validate(local_type == ValueTypes::ValueTypeFor(mem_type), &sig, code);
+      Validate(local_type == ValueType::For(mem_type), &sig, code);
     }
   }
 }
@@ -1490,13 +1500,13 @@ TEST_F(FunctionBodyDecoderTest, AllStoreMemCombinations) {
       MachineType mem_type = machineTypes[j];
       byte code[] = {WASM_STORE_MEM(mem_type, WASM_ZERO, WASM_GET_LOCAL(0))};
       FunctionSig sig(0, 1, &local_type);
-      Validate(local_type == ValueTypes::ValueTypeFor(mem_type), &sig, code);
+      Validate(local_type == ValueType::For(mem_type), &sig, code);
     }
   }
 }
 
 TEST_F(FunctionBodyDecoderTest, SimpleCalls) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1511,7 +1521,7 @@ TEST_F(FunctionBodyDecoderTest, SimpleCalls) {
 }
 
 TEST_F(FunctionBodyDecoderTest, CallsWithTooFewArguments) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1525,7 +1535,7 @@ TEST_F(FunctionBodyDecoderTest, CallsWithTooFewArguments) {
 }
 
 TEST_F(FunctionBodyDecoderTest, CallsWithMismatchedSigs2) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1537,7 +1547,7 @@ TEST_F(FunctionBodyDecoderTest, CallsWithMismatchedSigs2) {
 }
 
 TEST_F(FunctionBodyDecoderTest, CallsWithMismatchedSigs3) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1557,7 +1567,7 @@ TEST_F(FunctionBodyDecoderTest, CallsWithMismatchedSigs3) {
 TEST_F(FunctionBodyDecoderTest, SimpleReturnCalls) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1574,7 +1584,7 @@ TEST_F(FunctionBodyDecoderTest, SimpleReturnCalls) {
 TEST_F(FunctionBodyDecoderTest, ReturnCallsWithTooFewArguments) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1590,7 +1600,7 @@ TEST_F(FunctionBodyDecoderTest, ReturnCallsWithTooFewArguments) {
 TEST_F(FunctionBodyDecoderTest, ReturnCallsWithMismatchedSigs) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1609,7 +1619,7 @@ TEST_F(FunctionBodyDecoderTest, ReturnCallsWithMismatchedSigs) {
 TEST_F(FunctionBodyDecoderTest, SimpleIndirectReturnCalls) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.AddTable(kWasmFuncRef, 20, true, 30);
   module = builder.module();
@@ -1628,7 +1638,7 @@ TEST_F(FunctionBodyDecoderTest, SimpleIndirectReturnCalls) {
 TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsOutOfBounds) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.AddTable(kWasmFuncRef, 20, false, 20);
   module = builder.module();
@@ -1650,9 +1660,9 @@ TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsOutOfBounds) {
 TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsWithMismatchedSigs3) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   byte sig0 = builder.AddSignature(sigs.i_f());
@@ -1681,7 +1691,7 @@ TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsWithMismatchedSigs3) {
 TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsWithoutTableCrash) {
   WASM_FEATURE_SCOPE(return_call);
 
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1697,9 +1707,9 @@ TEST_F(FunctionBodyDecoderTest, IndirectReturnCallsWithoutTableCrash) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IncompleteIndirectReturnCall) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   static byte code[] = {kExprReturnCallIndirect};
@@ -1739,8 +1749,8 @@ TEST_F(FunctionBodyDecoderTest, MultiReturnType) {
 
           ExpectValidates(&sig_cd_v, {WASM_CALL_FUNCTION0(0)});
 
-          if (ValueTypes::IsSubType(kValueTypes[c], kValueTypes[a]) &&
-              ValueTypes::IsSubType(kValueTypes[d], kValueTypes[b])) {
+          if (kValueTypes[c].IsSubTypeOf(kValueTypes[a]) &&
+              kValueTypes[d].IsSubTypeOf(kValueTypes[b])) {
             ExpectValidates(&sig_ab_v, {WASM_CALL_FUNCTION0(0)});
           } else {
             ExpectFailure(&sig_ab_v, {WASM_CALL_FUNCTION0(0)});
@@ -1752,7 +1762,7 @@ TEST_F(FunctionBodyDecoderTest, MultiReturnType) {
 }
 
 TEST_F(FunctionBodyDecoderTest, SimpleIndirectCalls) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.AddTable(kWasmFuncRef, 20, false, 20);
   module = builder.module();
@@ -1768,7 +1778,7 @@ TEST_F(FunctionBodyDecoderTest, SimpleIndirectCalls) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IndirectCallsOutOfBounds) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.AddTable(kWasmFuncRef, 20, false, 20);
   module = builder.module();
@@ -1785,9 +1795,9 @@ TEST_F(FunctionBodyDecoderTest, IndirectCallsOutOfBounds) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IndirectCallsWithMismatchedSigs3) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   byte sig0 = builder.AddSignature(sigs.i_f());
@@ -1808,7 +1818,7 @@ TEST_F(FunctionBodyDecoderTest, IndirectCallsWithMismatchedSigs3) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IndirectCallsWithoutTableCrash) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1823,9 +1833,9 @@ TEST_F(FunctionBodyDecoderTest, IndirectCallsWithoutTableCrash) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IncompleteIndirectCall) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   static byte code[] = {kExprCallIndirect};
@@ -1833,10 +1843,10 @@ TEST_F(FunctionBodyDecoderTest, IncompleteIndirectCall) {
 }
 
 TEST_F(FunctionBodyDecoderTest, IncompleteStore) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.InitializeMemory();
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   static byte code[] = {kExprI32StoreMem};
@@ -1845,10 +1855,10 @@ TEST_F(FunctionBodyDecoderTest, IncompleteStore) {
 
 TEST_F(FunctionBodyDecoderTest, IncompleteS8x16Shuffle) {
   WASM_FEATURE_SCOPE(simd);
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   builder.InitializeMemory();
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   static byte code[] = {kSimdPrefix,
@@ -1857,7 +1867,7 @@ TEST_F(FunctionBodyDecoderTest, IncompleteS8x16Shuffle) {
 }
 
 TEST_F(FunctionBodyDecoderTest, SimpleImportCalls) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1872,7 +1882,7 @@ TEST_F(FunctionBodyDecoderTest, SimpleImportCalls) {
 }
 
 TEST_F(FunctionBodyDecoderTest, ImportCallsWithMismatchedSigs3) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1892,7 +1902,7 @@ TEST_F(FunctionBodyDecoderTest, ImportCallsWithMismatchedSigs3) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Int32Globals) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1904,7 +1914,7 @@ TEST_F(FunctionBodyDecoderTest, Int32Globals) {
 }
 
 TEST_F(FunctionBodyDecoderTest, ImmutableGlobal) {
-  FunctionSig* sig = sigs.v_v();
+  const FunctionSig* sig = sigs.v_v();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1916,7 +1926,7 @@ TEST_F(FunctionBodyDecoderTest, ImmutableGlobal) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Int32Globals_fail) {
-  FunctionSig* sig = sigs.i_i();
+  const FunctionSig* sig = sigs.i_i();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1937,7 +1947,7 @@ TEST_F(FunctionBodyDecoderTest, Int32Globals_fail) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Int64Globals) {
-  FunctionSig* sig = sigs.l_l();
+  const FunctionSig* sig = sigs.l_l();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1954,7 +1964,7 @@ TEST_F(FunctionBodyDecoderTest, Int64Globals) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Float32Globals) {
-  FunctionSig* sig = sigs.f_ff();
+  const FunctionSig* sig = sigs.f_ff();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1966,7 +1976,7 @@ TEST_F(FunctionBodyDecoderTest, Float32Globals) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Float64Globals) {
-  FunctionSig* sig = sigs.d_dd();
+  const FunctionSig* sig = sigs.d_dd();
   TestModuleBuilder builder;
   module = builder.module();
 
@@ -1986,8 +1996,7 @@ TEST_F(FunctionBodyDecoderTest, AllGetGlobalCombinations) {
       TestModuleBuilder builder;
       module = builder.module();
       builder.AddGlobal(global_type);
-      Validate(ValueTypes::IsSubType(global_type, local_type), &sig,
-               {WASM_GET_GLOBAL(0)});
+      Validate(global_type.IsSubTypeOf(local_type), &sig, {WASM_GET_GLOBAL(0)});
     }
   }
 }
@@ -2001,7 +2010,7 @@ TEST_F(FunctionBodyDecoderTest, AllSetGlobalCombinations) {
       TestModuleBuilder builder;
       module = builder.module();
       builder.AddGlobal(global_type);
-      Validate(ValueTypes::IsSubType(local_type, global_type), &sig,
+      Validate(local_type.IsSubTypeOf(global_type), &sig,
                {WASM_SET_GLOBAL(0, WASM_GET_LOCAL(0))});
     }
   }
@@ -2181,7 +2190,7 @@ TEST_F(FunctionBodyDecoderTest, AsmJsBinOpsCheckOrigin) {
   FunctionSig sig_d_id(1, 2, float64int32float64);
   struct {
     WasmOpcode op;
-    FunctionSig* sig;
+    const FunctionSig* sig;
   } AsmJsBinOps[] = {
       {kExprF64Atan2, sigs.d_dd()},
       {kExprF64Pow, sigs.d_dd()},
@@ -2225,7 +2234,7 @@ TEST_F(FunctionBodyDecoderTest, AsmJsUnOpsCheckOrigin) {
   FunctionSig sig_d_i(1, 1, float64int32);
   struct {
     WasmOpcode op;
-    FunctionSig* sig;
+    const FunctionSig* sig;
   } AsmJsUnOps[] = {{kExprF64Acos, sigs.d_d()},
                     {kExprF64Asin, sigs.d_d()},
                     {kExprF64Atan, sigs.d_d()},
@@ -2367,9 +2376,8 @@ TEST_F(FunctionBodyDecoderTest, BreakNesting_6_levels) {
 }
 
 TEST_F(FunctionBodyDecoderTest, Break_TypeCheck) {
-  FunctionSig* sigarray[] = {sigs.i_i(), sigs.l_l(), sigs.f_ff(), sigs.d_dd()};
-  for (size_t i = 0; i < arraysize(sigarray); i++) {
-    FunctionSig* sig = sigarray[i];
+  for (const FunctionSig* sig :
+       {sigs.i_i(), sigs.l_l(), sigs.f_ff(), sigs.d_dd()}) {
     // unify X and X => OK
     byte code[] = {WASM_BLOCK_T(
         sig->GetReturn(), WASM_IF(WASM_ZERO, WASM_BRV(0, WASM_GET_LOCAL(0))),
@@ -2398,8 +2406,7 @@ TEST_F(FunctionBodyDecoderTest, Break_TypeCheckAll1) {
           sig.GetReturn(), WASM_IF(WASM_ZERO, WASM_BRV(0, WASM_GET_LOCAL(0))),
           WASM_GET_LOCAL(1))};
 
-      Validate(ValueTypes::IsSubType(kValueTypes[j], kValueTypes[i]), &sig,
-               code);
+      Validate(kValueTypes[j].IsSubTypeOf(kValueTypes[i]), &sig, code);
     }
   }
 }
@@ -2413,8 +2420,7 @@ TEST_F(FunctionBodyDecoderTest, Break_TypeCheckAll2) {
                                     WASM_BRV_IF_ZERO(0, WASM_GET_LOCAL(0)),
                                     WASM_GET_LOCAL(1))};
 
-      Validate(ValueTypes::IsSubType(kValueTypes[j], kValueTypes[i]), &sig,
-               code);
+      Validate(kValueTypes[j].IsSubTypeOf(kValueTypes[i]), &sig, code);
     }
   }
 }
@@ -2428,8 +2434,7 @@ TEST_F(FunctionBodyDecoderTest, Break_TypeCheckAll3) {
                                     WASM_GET_LOCAL(1),
                                     WASM_BRV_IF_ZERO(0, WASM_GET_LOCAL(0)))};
 
-      Validate(ValueTypes::IsSubType(kValueTypes[j], kValueTypes[i]), &sig,
-               code);
+      Validate(kValueTypes[j].IsSubTypeOf(kValueTypes[i]), &sig, code);
     }
   }
 }
@@ -2473,8 +2478,7 @@ TEST_F(FunctionBodyDecoderTest, BreakIf_val_type) {
           types[1], WASM_BRV_IF(0, WASM_GET_LOCAL(1), WASM_GET_LOCAL(2)),
           WASM_DROP, WASM_GET_LOCAL(0))};
 
-      Validate(ValueTypes::IsSubType(kValueTypes[j], kValueTypes[i]), &sig,
-               code);
+      Validate(kValueTypes[j].IsSubTypeOf(kValueTypes[i]), &sig, code);
     }
   }
 }
@@ -3203,8 +3207,8 @@ TEST_F(FunctionBodyDecoderTest, BulkMemoryOpsWithoutMemory) {
 
 TEST_F(FunctionBodyDecoderTest, TableInit) {
   TestModuleBuilder builder;
-  builder.InitializeTable();
-  builder.AddPassiveElementSegment();
+  builder.InitializeTable(wasm::kWasmFuncRef);
+  builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
   module = builder.module();
 
   ExpectFailure(sigs.v_v(),
@@ -3216,10 +3220,22 @@ TEST_F(FunctionBodyDecoderTest, TableInit) {
                 {WASM_TABLE_INIT(0, 1, WASM_ZERO, WASM_ZERO, WASM_ZERO)});
 }
 
+TEST_F(FunctionBodyDecoderTest, TableInitWrongType) {
+  TestModuleBuilder builder;
+  uint32_t table_index = builder.InitializeTable(wasm::kWasmFuncRef);
+  uint32_t element_index = builder.AddPassiveElementSegment(wasm::kWasmAnyRef);
+  module = builder.module();
+
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  ExpectFailure(sigs.v_v(), {WASM_TABLE_INIT(table_index, element_index,
+                                             WASM_ZERO, WASM_ZERO, WASM_ZERO)});
+}
+
 TEST_F(FunctionBodyDecoderTest, TableInitInvalid) {
   TestModuleBuilder builder;
-  builder.InitializeTable();
-  builder.AddPassiveElementSegment();
+  builder.InitializeTable(wasm::kWasmFuncRef);
+  builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
   module = builder.module();
 
   WASM_FEATURE_SCOPE(bulk_memory);
@@ -3232,8 +3248,8 @@ TEST_F(FunctionBodyDecoderTest, TableInitInvalid) {
 
 TEST_F(FunctionBodyDecoderTest, ElemDrop) {
   TestModuleBuilder builder;
-  builder.InitializeTable();
-  builder.AddPassiveElementSegment();
+  builder.InitializeTable(wasm::kWasmFuncRef);
+  builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
   module = builder.module();
 
   ExpectFailure(sigs.v_v(), {WASM_ELEM_DROP(0)});
@@ -3242,11 +3258,62 @@ TEST_F(FunctionBodyDecoderTest, ElemDrop) {
   ExpectFailure(sigs.v_v(), {WASM_ELEM_DROP(1)});
 }
 
+TEST_F(FunctionBodyDecoderTest, TableInitDeclarativeElem) {
+  TestModuleBuilder builder;
+  builder.InitializeTable(wasm::kWasmFuncRef);
+  builder.AddDeclarativeElementSegment();
+  module = builder.module();
+
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  byte code[] = {WASM_TABLE_INIT(0, 0, WASM_ZERO, WASM_ZERO, WASM_ZERO),
+                 WASM_END};
+  for (size_t i = 0; i <= arraysize(code); ++i) {
+    Validate(i == arraysize(code), sigs.v_v(), VectorOf(code, i), kOmitEnd);
+  }
+}
+
+TEST_F(FunctionBodyDecoderTest, DeclarativeElemDrop) {
+  TestModuleBuilder builder;
+  builder.InitializeTable(wasm::kWasmFuncRef);
+  builder.AddDeclarativeElementSegment();
+  module = builder.module();
+
+  ExpectFailure(sigs.v_v(), {WASM_ELEM_DROP(0)});
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  ExpectValidates(sigs.v_v(), {WASM_ELEM_DROP(0)});
+  ExpectFailure(sigs.v_v(), {WASM_ELEM_DROP(1)});
+}
+
+TEST_F(FunctionBodyDecoderTest, RefFuncDeclared) {
+  TestModuleBuilder builder;
+  builder.InitializeTable(wasm::kWasmStmt);
+  byte function_index = builder.AddFunction(sigs.v_i());
+  module = builder.module();
+
+  ExpectFailure(sigs.a_v(), {WASM_REF_FUNC(function_index)});
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  ExpectValidates(sigs.a_v(), {WASM_REF_FUNC(function_index)});
+}
+
+TEST_F(FunctionBodyDecoderTest, RefFuncUndeclared) {
+  TestModuleBuilder builder;
+  builder.InitializeTable(wasm::kWasmStmt);
+  byte function_index = builder.AddFunction(sigs.v_i(), false);
+  module = builder.module();
+
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  ExpectFailure(sigs.a_v(), {WASM_REF_FUNC(function_index)});
+}
+
 TEST_F(FunctionBodyDecoderTest, ElemSegmentIndexUnsigned) {
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmFuncRef);
   for (int i = 0; i < 65; ++i) {
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
   }
   module = builder.module();
 
@@ -3260,7 +3327,7 @@ TEST_F(FunctionBodyDecoderTest, ElemSegmentIndexUnsigned) {
 
 TEST_F(FunctionBodyDecoderTest, TableCopy) {
   TestModuleBuilder builder;
-  builder.InitializeTable();
+  builder.InitializeTable(wasm::kWasmStmt);
   module = builder.module();
 
   ExpectFailure(sigs.v_v(),
@@ -3270,6 +3337,18 @@ TEST_F(FunctionBodyDecoderTest, TableCopy) {
                   {WASM_TABLE_COPY(0, 0, WASM_ZERO, WASM_ZERO, WASM_ZERO)});
 }
 
+TEST_F(FunctionBodyDecoderTest, TableCopyWrongType) {
+  TestModuleBuilder builder;
+  uint32_t dst_table_index = builder.InitializeTable(wasm::kWasmFuncRef);
+  uint32_t src_table_index = builder.InitializeTable(wasm::kWasmAnyRef);
+  module = builder.module();
+
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  ExpectFailure(sigs.v_v(), {WASM_TABLE_COPY(dst_table_index, src_table_index,
+                                             WASM_ZERO, WASM_ZERO, WASM_ZERO)});
+}
+
 TEST_F(FunctionBodyDecoderTest, TableGrow) {
   TestModuleBuilder builder;
   byte tab_func = builder.AddTable(kWasmFuncRef, 10, true, 20);
@@ -3369,7 +3448,7 @@ TEST_F(FunctionBodyDecoderTest, TableOpsWithoutTable) {
   }
   {
     WASM_FEATURE_SCOPE(bulk_memory);
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
     ExpectFailure(sigs.v_v(),
                   {WASM_TABLE_INIT(0, 0, WASM_ZERO, WASM_ZERO, WASM_ZERO)});
     ExpectFailure(sigs.v_v(),
@@ -3383,7 +3462,7 @@ TEST_F(FunctionBodyDecoderTest, TableCopyMultiTable) {
   {
     TestModuleBuilder builder;
     builder.AddTable(kWasmAnyRef, 10, true, 20);
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
     module = builder.module();
     // We added one table, therefore table.copy on table 0 should work.
     int table_src = 0;
@@ -3405,7 +3484,7 @@ TEST_F(FunctionBodyDecoderTest, TableCopyMultiTable) {
     TestModuleBuilder builder;
     builder.AddTable(kWasmAnyRef, 10, true, 20);
     builder.AddTable(kWasmAnyRef, 10, true, 20);
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
     module = builder.module();
     // We added two tables, therefore table.copy on table 0 should work.
     int table_src = 0;
@@ -3433,7 +3512,7 @@ TEST_F(FunctionBodyDecoderTest, TableInitMultiTable) {
   {
     TestModuleBuilder builder;
     builder.AddTable(kWasmAnyRef, 10, true, 20);
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
     module = builder.module();
     // We added one table, therefore table.init on table 0 should work.
     int table_index = 0;
@@ -3448,7 +3527,7 @@ TEST_F(FunctionBodyDecoderTest, TableInitMultiTable) {
     TestModuleBuilder builder;
     builder.AddTable(kWasmAnyRef, 10, true, 20);
     builder.AddTable(kWasmAnyRef, 10, true, 20);
-    builder.AddPassiveElementSegment();
+    builder.AddPassiveElementSegment(wasm::kWasmFuncRef);
     module = builder.module();
     // We added two tables, therefore table.init on table 0 should work.
     int table_index = 0;
@@ -3727,8 +3806,7 @@ TEST_F(LocalDeclDecoderTest, OneLocal) {
   WASM_FEATURE_SCOPE(anyref);
   for (size_t i = 0; i < arraysize(kValueTypes); i++) {
     ValueType type = kValueTypes[i];
-    const byte data[] = {1, 1,
-                         static_cast<byte>(ValueTypes::ValueTypeCodeFor(type))};
+    const byte data[] = {1, 1, static_cast<byte>(type.value_type_code())};
     BodyLocalDecls decls(zone());
     bool result = DecodeLocalDecls(&decls, data, data + sizeof(data));
     EXPECT_TRUE(result);
@@ -3743,8 +3821,7 @@ TEST_F(LocalDeclDecoderTest, FiveLocals) {
   WASM_FEATURE_SCOPE(anyref);
   for (size_t i = 0; i < arraysize(kValueTypes); i++) {
     ValueType type = kValueTypes[i];
-    const byte data[] = {1, 5,
-                         static_cast<byte>(ValueTypes::ValueTypeCodeFor(type))};
+    const byte data[] = {1, 5, static_cast<byte>(type.value_type_code())};
     BodyLocalDecls decls(zone());
     bool result = DecodeLocalDecls(&decls, data, data + sizeof(data));
     EXPECT_TRUE(result);
@@ -3809,8 +3886,7 @@ TEST_F(LocalDeclDecoderTest, UseEncoder) {
 TEST_F(LocalDeclDecoderTest, ExnRef) {
   WASM_FEATURE_SCOPE(eh);
   ValueType type = kWasmExnRef;
-  const byte data[] = {1, 1,
-                       static_cast<byte>(ValueTypes::ValueTypeCodeFor(type))};
+  const byte data[] = {1, 1, static_cast<byte>(type.value_type_code())};
   BodyLocalDecls decls(zone());
   bool result = DecodeLocalDecls(&decls, data, data + sizeof(data));
   EXPECT_TRUE(result);
diff --git a/deps/v8/test/unittests/wasm/module-decoder-unittest.cc b/deps/v8/test/unittests/wasm/module-decoder-unittest.cc
index f88beef794..68a2bb6ff1 100644
--- a/deps/v8/test/unittests/wasm/module-decoder-unittest.cc
+++ b/deps/v8/test/unittests/wasm/module-decoder-unittest.cc
@@ -130,6 +130,13 @@ struct CheckLEB1 : std::integral_constant<size_t, num> {
 
 #define EXPECT_FAILURE(data) EXPECT_FAILURE_LEN(data, sizeof(data))
 
+#define EXPECT_FAILURE_WITH_MSG(data, msg)                         \
+  do {                                                             \
+    ModuleResult result = DecodeModule(data, data + sizeof(data)); \
+    EXPECT_FALSE(result.ok());                                     \
+    EXPECT_THAT(result.error().message(), HasSubstr(msg));         \
+  } while (false)
+
 #define EXPECT_OFF_END_FAILURE(data, min)                           \
   do {                                                              \
     STATIC_ASSERT(min < arraysize(data));                           \
@@ -252,6 +259,7 @@ TEST_F(WasmModuleVerifyTest, OneGlobal) {
 
 TEST_F(WasmModuleVerifyTest, AnyRefGlobal) {
   WASM_FEATURE_SCOPE(anyref);
+  WASM_FEATURE_SCOPE(bulk_memory);
   static const byte data[] = {
       // sig#0 ---------------------------------------------------------------
       SIGNATURES_SECTION_VOID_VOID,
@@ -265,6 +273,16 @@ TEST_F(WasmModuleVerifyTest, AnyRefGlobal) {
               kLocalAnyRef,                 // local type
               0,                            // immutable
               WASM_INIT_EXPR_REF_FUNC(1)),  // init
+      SECTION(Element,                      // section name
+              ENTRY_COUNT(2),               // entry count
+              DECLARATIVE,                  // flags 0
+              kExternalFunction,            // type
+              ENTRY_COUNT(1),               // func entry count
+              FUNC_INDEX(0),                // func index
+              DECLARATIVE_WITH_ELEMENTS,    // flags 1
+              kLocalFuncRef,                // local type
+              ENTRY_COUNT(1),               // func ref count
+              REF_FUNC_ELEMENT(1)),         // func ref
       TWO_EMPTY_BODIES};
 
   {
@@ -290,6 +308,7 @@ TEST_F(WasmModuleVerifyTest, AnyRefGlobal) {
 
 TEST_F(WasmModuleVerifyTest, FuncRefGlobal) {
   WASM_FEATURE_SCOPE(anyref);
+  WASM_FEATURE_SCOPE(bulk_memory);
   static const byte data[] = {
       // sig#0 ---------------------------------------------------------------
       SIGNATURES_SECTION_VOID_VOID,
@@ -303,6 +322,16 @@ TEST_F(WasmModuleVerifyTest, FuncRefGlobal) {
               kLocalFuncRef,                // local type
               0,                            // immutable
               WASM_INIT_EXPR_REF_FUNC(1)),  // init
+      SECTION(Element,                      // section name
+              ENTRY_COUNT(2),               // entry count
+              DECLARATIVE,                  // flags 0
+              kExternalFunction,            // type
+              ENTRY_COUNT(1),               // func entry count
+              FUNC_INDEX(0),                // func index
+              DECLARATIVE_WITH_ELEMENTS,    // flags 1
+              kLocalFuncRef,                // local type
+              ENTRY_COUNT(1),               // func ref count
+              REF_FUNC_ELEMENT(1)),         // func ref
       TWO_EMPTY_BODIES};
   {
     // Should decode to two globals.
@@ -695,9 +724,9 @@ TEST_F(WasmModuleVerifyTest, Exception_invalid_attribute) {
 }
 
 TEST_F(WasmModuleVerifyTest, ExceptionSectionCorrectPlacement) {
-  static const byte data[] = {SECTION(Import, ENTRY_COUNT(0)),
+  static const byte data[] = {SECTION(Memory, ENTRY_COUNT(0)),
                               SECTION(Exception, ENTRY_COUNT(0)),
-                              SECTION(Export, ENTRY_COUNT(0))};
+                              SECTION(Global, ENTRY_COUNT(0))};
   FAIL_IF_NO_EXPERIMENTAL_EH(data);
 
   WASM_FEATURE_SCOPE(eh);
@@ -705,37 +734,37 @@ TEST_F(WasmModuleVerifyTest, ExceptionSectionCorrectPlacement) {
   EXPECT_OK(result);
 }
 
-TEST_F(WasmModuleVerifyTest, ExceptionSectionAfterExport) {
-  static const byte data[] = {SECTION(Export, ENTRY_COUNT(0)),
+TEST_F(WasmModuleVerifyTest, ExceptionSectionAfterGlobal) {
+  static const byte data[] = {SECTION(Global, ENTRY_COUNT(0)),
                               SECTION(Exception, ENTRY_COUNT(0))};
   FAIL_IF_NO_EXPERIMENTAL_EH(data);
 
   WASM_FEATURE_SCOPE(eh);
   ModuleResult result = DecodeModule(data, data + sizeof(data));
   EXPECT_NOT_OK(result,
-                "The Exception section must appear before the Export section");
+                "The Exception section must appear before the Global section");
 }
 
-TEST_F(WasmModuleVerifyTest, ExceptionSectionBeforeGlobal) {
+TEST_F(WasmModuleVerifyTest, ExceptionSectionBeforeMemory) {
   static const byte data[] = {SECTION(Exception, ENTRY_COUNT(0)),
-                              SECTION(Global, ENTRY_COUNT(0))};
+                              SECTION(Memory, ENTRY_COUNT(0))};
   FAIL_IF_NO_EXPERIMENTAL_EH(data);
 
   WASM_FEATURE_SCOPE(eh);
   ModuleResult result = DecodeModule(data, data + sizeof(data));
-  EXPECT_NOT_OK(result, "unexpected section <Global>");
+  EXPECT_NOT_OK(result, "unexpected section <Memory>");
 }
 
-TEST_F(WasmModuleVerifyTest, ExceptionSectionAfterMemoryBeforeGlobal) {
+TEST_F(WasmModuleVerifyTest, ExceptionSectionAfterTableBeforeMemory) {
   STATIC_ASSERT(kMemorySectionCode + 1 == kGlobalSectionCode);
-  static const byte data[] = {SECTION(Memory, ENTRY_COUNT(0)),
+  static const byte data[] = {SECTION(Table, ENTRY_COUNT(0)),
                               SECTION(Exception, ENTRY_COUNT(0)),
-                              SECTION(Global, ENTRY_COUNT(0))};
+                              SECTION(Memory, ENTRY_COUNT(0))};
   FAIL_IF_NO_EXPERIMENTAL_EH(data);
 
   WASM_FEATURE_SCOPE(eh);
   ModuleResult result = DecodeModule(data, data + sizeof(data));
-  EXPECT_NOT_OK(result, "unexpected section <Global>");
+  EXPECT_NOT_OK(result, "unexpected section <Memory>");
 }
 
 TEST_F(WasmModuleVerifyTest, ExceptionImport) {
@@ -1493,7 +1522,7 @@ class WasmSignatureDecodeTest : public TestWithZone {
  public:
   WasmFeatures enabled_features_ = WasmFeatures::None();
 
-  FunctionSig* DecodeSig(const byte* start, const byte* end) {
+  const FunctionSig* DecodeSig(const byte* start, const byte* end) {
     return DecodeWasmSignatureForTesting(enabled_features_, zone(), start, end);
   }
 };
@@ -1502,7 +1531,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_v_v) {
   static const byte data[] = {SIG_ENTRY_v_v};
   v8::internal::AccountingAllocator allocator;
   Zone zone(&allocator, ZONE_NAME);
-  FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+  const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
   EXPECT_TRUE(sig != nullptr);
   EXPECT_EQ(0u, sig->parameter_count());
@@ -1514,7 +1543,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_t_v) {
   for (size_t i = 0; i < arraysize(kValueTypes); i++) {
     ValueTypePair ret_type = kValueTypes[i];
     const byte data[] = {SIG_ENTRY_x(ret_type.code)};
-    FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+    const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
     EXPECT_TRUE(sig != nullptr);
     EXPECT_EQ(0u, sig->parameter_count());
@@ -1528,7 +1557,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_v_t) {
   for (size_t i = 0; i < arraysize(kValueTypes); i++) {
     ValueTypePair param_type = kValueTypes[i];
     const byte data[] = {SIG_ENTRY_v_x(param_type.code)};
-    FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+    const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
     EXPECT_TRUE(sig != nullptr);
     EXPECT_EQ(1u, sig->parameter_count());
@@ -1544,7 +1573,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_t_t) {
     for (size_t j = 0; j < arraysize(kValueTypes); j++) {
       ValueTypePair param_type = kValueTypes[j];
       const byte data[] = {SIG_ENTRY_x_x(ret_type.code, param_type.code)};
-      FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+      const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
       EXPECT_TRUE(sig != nullptr);
       EXPECT_EQ(1u, sig->parameter_count());
@@ -1564,7 +1593,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_i_tt) {
       ValueTypePair p1_type = kValueTypes[j];
       const byte data[] = {
           SIG_ENTRY_x_xx(kLocalI32, p0_type.code, p1_type.code)};
-      FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+      const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
       EXPECT_TRUE(sig != nullptr);
       EXPECT_EQ(2u, sig->parameter_count());
@@ -1584,7 +1613,7 @@ TEST_F(WasmSignatureDecodeTest, Ok_tt_tt) {
       ValueTypePair p1_type = kValueTypes[j];
       const byte data[] = {SIG_ENTRY_xx_xx(p0_type.code, p1_type.code,
                                            p0_type.code, p1_type.code)};
-      FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+      const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
 
       EXPECT_TRUE(sig != nullptr);
       EXPECT_EQ(2u, sig->parameter_count());
@@ -1601,7 +1630,7 @@ TEST_F(WasmSignatureDecodeTest, TooManyParams) {
   static const byte data[] = {kWasmFunctionTypeCode,
                               WASM_I32V_3(kV8MaxWasmFunctionParams + 1),
                               kLocalI32, 0};
-  FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+  const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
   EXPECT_FALSE(sig != nullptr);
 }
 
@@ -1613,7 +1642,7 @@ TEST_F(WasmSignatureDecodeTest, TooManyReturns) {
         enable_mv ? kV8MaxWasmFunctionMultiReturns : kV8MaxWasmFunctionReturns);
     byte data[] = {kWasmFunctionTypeCode, 0, WASM_I32V_3(max_return_count + 1),
                    kLocalI32};
-    FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+    const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
     EXPECT_EQ(nullptr, sig);
   }
 }
@@ -1626,7 +1655,7 @@ TEST_F(WasmSignatureDecodeTest, Fail_off_end) {
 
     for (int i = 0; i < p + 1; i++) {
       // Should fall off the end for all signatures.
-      FunctionSig* sig = DecodeSig(data, data + i);
+      const FunctionSig* sig = DecodeSig(data, data + i);
       EXPECT_EQ(nullptr, sig);
     }
   }
@@ -1641,7 +1670,7 @@ TEST_F(WasmSignatureDecodeTest, Fail_anyref_without_flag) {
       byte data[] = {SIG_ENTRY_x_xx(kLocalI32, kLocalI32, kLocalI32)};
       if (i >= arraysize(data)) break;
       data[i] = invalid_type;
-      FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+      const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
       EXPECT_EQ(nullptr, sig);
     }
   }
@@ -1653,26 +1682,26 @@ TEST_F(WasmSignatureDecodeTest, Fail_invalid_type) {
     byte data[] = {SIG_ENTRY_x_xx(kLocalI32, kLocalI32, kLocalI32)};
     if (i >= arraysize(data)) break;
     data[i] = kInvalidType;
-    FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+    const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
     EXPECT_EQ(nullptr, sig);
   }
 }
 
 TEST_F(WasmSignatureDecodeTest, Fail_invalid_ret_type1) {
   static const byte data[] = {SIG_ENTRY_x_x(kLocalVoid, kLocalI32)};
-  FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+  const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
   EXPECT_EQ(nullptr, sig);
 }
 
 TEST_F(WasmSignatureDecodeTest, Fail_invalid_param_type1) {
   static const byte data[] = {SIG_ENTRY_x_x(kLocalI32, kLocalVoid)};
-  FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+  const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
   EXPECT_EQ(nullptr, sig);
 }
 
 TEST_F(WasmSignatureDecodeTest, Fail_invalid_param_type2) {
   static const byte data[] = {SIG_ENTRY_x_xx(kLocalI32, kLocalI32, kLocalVoid)};
-  FunctionSig* sig = DecodeSig(data, data + sizeof(data));
+  const FunctionSig* sig = DecodeSig(data, data + sizeof(data));
   EXPECT_EQ(nullptr, sig);
 }
 
@@ -1724,12 +1753,22 @@ TEST_F(WasmModuleVerifyTest, SectionWithoutNameLength) {
   EXPECT_FAILURE(data);
 }
 
+TEST_F(WasmModuleVerifyTest, EmptyCustomSectionIsInvalid) {
+  // An empty custom section is invalid, because at least one byte for the
+  // length of the custom section name is required.
+  const byte data[] = {
+      0,  // unknown section code.
+      0   // section length.
+  };
+  EXPECT_FAILURE(data);
+}
+
 TEST_F(WasmModuleVerifyTest, TheLoneliestOfValidModulesTheTrulyEmptyOne) {
   const byte data[] = {
       0,  // unknown section code.
-      0,  // Empty section name.
-          // No section name, no content, nothing but sadness.
-      0,  // No section content.
+      1,  // section length, only one byte for the name length.
+      0,  // string length of 0.
+          // Empty section name, no content, nothing but sadness.
   };
   EXPECT_VERIFIES(data);
 }
@@ -2507,7 +2546,7 @@ TEST_F(WasmModuleVerifyTest, PassiveElementSegmentWithIndices) {
       ONE_EMPTY_FUNCTION(SIG_INDEX(0)),
       // table declaration -----------------------------------------------------
       SECTION(Table, ENTRY_COUNT(1), kLocalFuncRef, 0, 1),
-      // element segments  -----------------------------------------------------
+      // element segments ------------------------------------------------------
       SECTION(Element, ENTRY_COUNT(1), PASSIVE, kExternalFunction,
               ENTRY_COUNT(3), U32V_1(0), U32V_1(0), U32V_1(0)),
       // code ------------------------------------------------------------------
@@ -2518,6 +2557,67 @@ TEST_F(WasmModuleVerifyTest, PassiveElementSegmentWithIndices) {
   EXPECT_OFF_END_FAILURE(data, arraysize(data) - 5);
 }
 
+TEST_F(WasmModuleVerifyTest, DeclarativeElementSegmentFuncRef) {
+  static const byte data[] = {
+      // sig#0 -----------------------------------------------------------------
+      SIGNATURES_SECTION_VOID_VOID,
+      // funcs -----------------------------------------------------------------
+      ONE_EMPTY_FUNCTION(SIG_INDEX(0)),
+      // element segments  -----------------------------------------------------
+      SECTION(Element,                    // section name
+              ENTRY_COUNT(1),             // entry count
+              DECLARATIVE_WITH_ELEMENTS,  // flags
+              kLocalFuncRef,              // local type
+              U32V_1(0)),                 // func ref count
+      // code ------------------------------------------------------------------
+      ONE_EMPTY_BODY};
+  EXPECT_FAILURE(data);
+  WASM_FEATURE_SCOPE(bulk_memory);
+  EXPECT_FAILURE(data);
+  WASM_FEATURE_SCOPE(anyref);
+  EXPECT_VERIFIES(data);
+}
+
+TEST_F(WasmModuleVerifyTest, DeclarativeElementSegmentWithInvalidIndex) {
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  static const byte data[] = {
+      // sig#0 -----------------------------------------------------------------
+      SIGNATURES_SECTION_VOID_VOID,
+      // funcs -----------------------------------------------------------------
+      ONE_EMPTY_FUNCTION(SIG_INDEX(0)),
+      // element segments  -----------------------------------------------------
+      SECTION(Element,            // section name
+              ENTRY_COUNT(1),     // entry count
+              DECLARATIVE,        // flags
+              kExternalFunction,  // type
+              ENTRY_COUNT(2),     // func index count
+              U32V_1(0),          // func index
+              U32V_1(1)),         // func index
+      // code ------------------------------------------------------------------
+      ONE_EMPTY_BODY};
+  EXPECT_FAILURE_WITH_MSG(data, "element function index 1 out of bounds");
+}
+
+TEST_F(WasmModuleVerifyTest, DeclarativeElementSegmentMissingForGlobal) {
+  WASM_FEATURE_SCOPE(bulk_memory);
+  WASM_FEATURE_SCOPE(anyref);
+  static const byte data[] = {
+      // sig#0 -----------------------------------------------------------------
+      SIGNATURES_SECTION_VOID_VOID,
+      // funcs -----------------------------------------------------------------
+      ONE_EMPTY_FUNCTION(SIG_INDEX(0)),
+      // global definitions ----------------------------------------------------
+      SECTION(Global,                       // section name
+              ENTRY_COUNT(1),               // entry count
+              kLocalAnyRef,                 // local type
+              0,                            // immutable
+              WASM_INIT_EXPR_REF_FUNC(0)),  // init
+      // code ------------------------------------------------------------------
+      ONE_EMPTY_BODY};
+  EXPECT_FAILURE_WITH_MSG(data, "undeclared reference to function");
+}
+
 TEST_F(WasmModuleVerifyTest, DataCountSectionCorrectPlacement) {
   static const byte data[] = {SECTION(Element, ENTRY_COUNT(0)),
                               SECTION(DataCount, ENTRY_COUNT(0)),
diff --git a/deps/v8/test/unittests/wasm/wasm-compiler-unittest.cc b/deps/v8/test/unittests/wasm/wasm-compiler-unittest.cc
index 4b9f78dfdc..0b8cf6d11d 100644
--- a/deps/v8/test/unittests/wasm/wasm-compiler-unittest.cc
+++ b/deps/v8/test/unittests/wasm/wasm-compiler-unittest.cc
@@ -21,9 +21,9 @@ TEST_F(WasmCallDescriptorTest, TestAnyRefIsGrouped) {
   ValueType params[kMaxCount];
 
   for (size_t i = 0; i < kMaxCount; i += 2) {
-    params[i] = ValueType::kWasmAnyRef;
+    params[i] = kWasmAnyRef;
     CHECK_LT(i + 1, kMaxCount);
-    params[i + 1] = ValueType::kWasmI32;
+    params[i + 1] = kWasmI32;
   }
 
   for (size_t count = 1; count <= kMaxCount; ++count) {
diff --git a/deps/v8/test/wasm-js/tests.tar.gz.sha1 b/deps/v8/test/wasm-js/tests.tar.gz.sha1
index b65f0c924f..a1ad6de73f 100644
--- a/deps/v8/test/wasm-js/tests.tar.gz.sha1
+++ b/deps/v8/test/wasm-js/tests.tar.gz.sha1
@@ -1 +1 @@
-998b2870df79bf5ae83eb80aa6adb4ec3110d197
\ No newline at end of file
+6e091ed0e8ef57cdbfa46265b0001f19e3bb0f20
\ No newline at end of file
diff --git a/deps/v8/test/wasm-js/wasm-js.status b/deps/v8/test/wasm-js/wasm-js.status
index af13e5a1b3..b8fe4c068a 100644
--- a/deps/v8/test/wasm-js/wasm-js.status
+++ b/deps/v8/test/wasm-js/wasm-js.status
@@ -4,9 +4,12 @@
 
 [
 [ALWAYS, {
-  # https://bugs.chromium.org/p/v8/issues/detail?id=8633
-  'limits': [SKIP],
+  # These are slow, and not useful to run for the proposals:
   'proposals/reference-types/limits': [SKIP],
+  'proposals/multi-value/limits': [SKIP],
+  'proposals/bulk-memory-operations/limits': [SKIP],
+  'proposals/JS-BigInt-integration/limits': [SKIP],
+  'proposals/js-types/limits': [SKIP],
   # TODO(v8:9673): Enable these spec tests once they exist, and the out-dated
   # tests have been removed.
   'proposals/JS-BigInt-integration/module/params-long': [FAIL],
@@ -18,6 +21,12 @@
   'constructor/instantiate': [SKIP],
 }],  # 'arch == s390 or arch == s390x or system == aix'
 
+['mode == debug or simulator_run or variant != default or arch == arm', {
+  # Slow, and we always have the same limits anyway.
+  # ODroid bots don't have enough memory to run the test.
+  'limits': [SKIP],
+}],  # mode == debug or simulator_run or variant != default or arch == arm
+
 ##############################################################################
 ['lite_mode or variant == jitless', {
   # TODO(v8:7777): Re-enable once wasm is supported in jitless mode.
diff --git a/deps/v8/test/wasm-spec-tests/tests.tar.gz.sha1 b/deps/v8/test/wasm-spec-tests/tests.tar.gz.sha1
index b905b5674e..9f6ff04f64 100644
--- a/deps/v8/test/wasm-spec-tests/tests.tar.gz.sha1
+++ b/deps/v8/test/wasm-spec-tests/tests.tar.gz.sha1
@@ -1 +1 @@
-61d66d9a4019b8799d4be29b82424c5e5a4fb8b2
\ No newline at end of file
+acdfb34955e3b0e5031890aebaf552782f38f0f3
\ No newline at end of file
diff --git a/deps/v8/test/wasm-spec-tests/wasm-spec-tests.status b/deps/v8/test/wasm-spec-tests/wasm-spec-tests.status
index ccf27ed6a7..84daefc36d 100644
--- a/deps/v8/test/wasm-spec-tests/wasm-spec-tests.status
+++ b/deps/v8/test/wasm-spec-tests/wasm-spec-tests.status
@@ -24,15 +24,6 @@
   'proposals/multi-value/call': [FAIL],
   'proposals/multi-value/if': [FAIL],
   'proposals/multi-value/func': [FAIL],
-
-  # TODO(v8:10156): Spec tests are failing after rebasing the reference-types
-  # proposal on the bulk-operations proposal.
-  'proposals/reference-types/elem': [FAIL],
-  'proposals/reference-types/ref_func': [FAIL],
-  'proposals/reference-types/table_fill': [FAIL],
-  'proposals/reference-types/table_grow': [FAIL],
-  'proposals/reference-types/select': [FAIL],
-  'proposals/reference-types/br_table': [FAIL],
 }],  # ALWAYS
 
 ['arch == mipsel or arch == mips64el or arch == mips or arch == mips64', {
diff --git a/deps/v8/third_party/inspector_protocol/BUILD.gn b/deps/v8/third_party/inspector_protocol/BUILD.gn
index 9fcba22e04..33ef78c24b 100644
--- a/deps/v8/third_party/inspector_protocol/BUILD.gn
+++ b/deps/v8/third_party/inspector_protocol/BUILD.gn
@@ -14,7 +14,12 @@ v8_source_set("crdtp") {
   sources = [
     "crdtp/cbor.cc",
     "crdtp/cbor.h",
+    "crdtp/dispatch.cc",
+    "crdtp/dispatch.h",
+    "crdtp/error_support.cc",
+    "crdtp/error_support.h",
     "crdtp/export.h",
+    "crdtp/find_by_first.h",
     "crdtp/glue.h",
     "crdtp/json.cc",
     "crdtp/json.h",
@@ -22,14 +27,13 @@ v8_source_set("crdtp") {
     "crdtp/serializable.cc",
     "crdtp/serializable.h",
     "crdtp/serializer_traits.h",
+    "crdtp/span.cc",
     "crdtp/span.h",
     "crdtp/status.cc",
     "crdtp/status.h",
   ]
   configs = [ ":crdtp_config" ]
-  deps = [
-    ":crdtp_platform",
-  ]
+  deps = [ ":crdtp_platform" ]
 }
 
 # A small adapter library which only :crdtp may depend on.
@@ -39,9 +43,7 @@ v8_source_set("crdtp_platform") {
     "crdtp/json_platform.h",
     "crdtp/json_platform_v8.cc",
   ]
-  public_deps = [
-    "../..:v8_libbase",
-  ]
+  public_deps = [ "../..:v8_libbase" ]
   configs = [ ":crdtp_config" ]
 }
 
@@ -49,6 +51,9 @@ v8_source_set("crdtp_platform") {
 v8_source_set("crdtp_test") {
   sources = [
     "crdtp/cbor_test.cc",
+    "crdtp/dispatch_test.cc",
+    "crdtp/error_support_test.cc",
+    "crdtp/find_by_first_test.cc",
     "crdtp/glue_test.cc",
     "crdtp/json_test.cc",
     "crdtp/serializable_test.cc",
@@ -59,9 +64,7 @@ v8_source_set("crdtp_test") {
     "crdtp/status_test_support.h",
   ]
   configs = [ ":crdtp_config" ]
-  deps = [
-    ":crdtp_test_platform",
-  ]
+  deps = [ ":crdtp_test_platform" ]
   testonly = true
 }
 
diff --git a/deps/v8/third_party/inspector_protocol/README.v8 b/deps/v8/third_party/inspector_protocol/README.v8
index d9b68c0b17..d2d558ad3e 100644
--- a/deps/v8/third_party/inspector_protocol/README.v8
+++ b/deps/v8/third_party/inspector_protocol/README.v8
@@ -2,7 +2,7 @@ Name: inspector protocol
 Short Name: inspector_protocol
 URL: https://chromium.googlesource.com/deps/inspector_protocol/
 Version: 0
-Revision: 0213a8545f6362cd1cd5091cedf29747736552e8
+Revision: b7cda08cd6e522df2159413ba5f29d2a953cc1c4
 License: BSD
 License File: LICENSE
 Security Critical: no
diff --git a/deps/v8/third_party/inspector_protocol/code_generator.py b/deps/v8/third_party/inspector_protocol/code_generator.py
index 4260dbe5a4..92207b9159 100755
--- a/deps/v8/third_party/inspector_protocol/code_generator.py
+++ b/deps/v8/third_party/inspector_protocol/code_generator.py
@@ -655,26 +655,19 @@ def main():
     # Note these should be sorted in the right order.
     # TODO(dgozman): sort them programmatically based on commented includes.
     protocol_h_templates = [
-      "ErrorSupport_h.template",
       "Values_h.template",
       "Object_h.template",
       "ValueConversions_h.template",
-      "DispatcherBase_h.template",
-      "Parser_h.template",
     ]
 
     protocol_cpp_templates = [
       "Protocol_cpp.template",
-      "ErrorSupport_cpp.template",
       "Values_cpp.template",
       "Object_cpp.template",
-      "DispatcherBase_cpp.template",
-      "Parser_cpp.template",
     ]
 
     forward_h_templates = [
       "Forward_h.template",
-      "FrontendChannel_h.template",
     ]
 
     base_string_adapter_h_templates = [
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/dispatch.cc b/deps/v8/third_party/inspector_protocol/crdtp/dispatch.cc
new file mode 100644
index 0000000000..eb2b2d4fdc
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/dispatch.cc
@@ -0,0 +1,576 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "dispatch.h"
+
+#include <cassert>
+#include "cbor.h"
+#include "error_support.h"
+#include "find_by_first.h"
+#include "frontend_channel.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// DispatchResponse - Error status and chaining / fall through
+// =============================================================================
+
+// static
+DispatchResponse DispatchResponse::Success() {
+  DispatchResponse result;
+  result.code_ = DispatchCode::SUCCESS;
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::FallThrough() {
+  DispatchResponse result;
+  result.code_ = DispatchCode::FALL_THROUGH;
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::ParseError(std::string message) {
+  DispatchResponse result;
+  result.code_ = DispatchCode::PARSE_ERROR;
+  result.message_ = std::move(message);
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::InvalidRequest(std::string message) {
+  DispatchResponse result;
+  result.code_ = DispatchCode::INVALID_REQUEST;
+  result.message_ = std::move(message);
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::MethodNotFound(std::string message) {
+  DispatchResponse result;
+  result.code_ = DispatchCode::METHOD_NOT_FOUND;
+  result.message_ = std::move(message);
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::InvalidParams(std::string message) {
+  DispatchResponse result;
+  result.code_ = DispatchCode::INVALID_PARAMS;
+  result.message_ = std::move(message);
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::InternalError() {
+  DispatchResponse result;
+  result.code_ = DispatchCode::INTERNAL_ERROR;
+  result.message_ = "Internal error";
+  return result;
+}
+
+// static
+DispatchResponse DispatchResponse::ServerError(std::string message) {
+  DispatchResponse result;
+  result.code_ = DispatchCode::SERVER_ERROR;
+  result.message_ = std::move(message);
+  return result;
+}
+
+// =============================================================================
+// Dispatchable - a shallow parser for CBOR encoded DevTools messages
+// =============================================================================
+namespace {
+constexpr size_t kEncodedEnvelopeHeaderSize = 1 + 1 + sizeof(uint32_t);
+}  // namespace
+
+Dispatchable::Dispatchable(span<uint8_t> serialized) : serialized_(serialized) {
+  Status s = cbor::CheckCBORMessage(serialized);
+  if (!s.ok()) {
+    status_ = {Error::MESSAGE_MUST_BE_AN_OBJECT, s.pos};
+    return;
+  }
+  cbor::CBORTokenizer tokenizer(serialized);
+  if (tokenizer.TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) {
+    status_ = tokenizer.Status();
+    return;
+  }
+
+  // We checked for the envelope start byte above, so the tokenizer
+  // must agree here, since it's not an error.
+  assert(tokenizer.TokenTag() == cbor::CBORTokenTag::ENVELOPE);
+
+  // Before we enter the envelope, we save the position that we
+  // expect to see after we're done parsing the envelope contents.
+  // This way we can compare and produce an error if the contents
+  // didn't fit exactly into the envelope length.
+  const size_t pos_past_envelope = tokenizer.Status().pos +
+                                   kEncodedEnvelopeHeaderSize +
+                                   tokenizer.GetEnvelopeContents().size();
+  tokenizer.EnterEnvelope();
+  if (tokenizer.TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) {
+    status_ = tokenizer.Status();
+    return;
+  }
+  if (tokenizer.TokenTag() != cbor::CBORTokenTag::MAP_START) {
+    status_ = {Error::MESSAGE_MUST_BE_AN_OBJECT, tokenizer.Status().pos};
+    return;
+  }
+  assert(tokenizer.TokenTag() == cbor::CBORTokenTag::MAP_START);
+  tokenizer.Next();  // Now we should be pointed at the map key.
+  while (tokenizer.TokenTag() != cbor::CBORTokenTag::STOP) {
+    switch (tokenizer.TokenTag()) {
+      case cbor::CBORTokenTag::DONE:
+        status_ =
+            Status{Error::CBOR_UNEXPECTED_EOF_IN_MAP, tokenizer.Status().pos};
+        return;
+      case cbor::CBORTokenTag::ERROR_VALUE:
+        status_ = tokenizer.Status();
+        return;
+      case cbor::CBORTokenTag::STRING8:
+        if (!MaybeParseProperty(&tokenizer))
+          return;
+        break;
+      default:
+        // We require the top-level keys to be UTF8 (US-ASCII in practice).
+        status_ = Status{Error::CBOR_INVALID_MAP_KEY, tokenizer.Status().pos};
+        return;
+    }
+  }
+  tokenizer.Next();
+  if (!has_call_id_) {
+    status_ = Status{Error::MESSAGE_MUST_HAVE_INTEGER_ID_PROPERTY,
+                     tokenizer.Status().pos};
+    return;
+  }
+  if (method_.empty()) {
+    status_ = Status{Error::MESSAGE_MUST_HAVE_STRING_METHOD_PROPERTY,
+                     tokenizer.Status().pos};
+    return;
+  }
+  // The contents of the envelope parsed OK, now check that we're at
+  // the expected position.
+  if (pos_past_envelope != tokenizer.Status().pos) {
+    status_ = Status{Error::CBOR_ENVELOPE_CONTENTS_LENGTH_MISMATCH,
+                     tokenizer.Status().pos};
+    return;
+  }
+  if (tokenizer.TokenTag() != cbor::CBORTokenTag::DONE) {
+    status_ = Status{Error::CBOR_TRAILING_JUNK, tokenizer.Status().pos};
+    return;
+  }
+}
+
+bool Dispatchable::ok() const {
+  return status_.ok();
+}
+
+DispatchResponse Dispatchable::DispatchError() const {
+  // TODO(johannes): Replace with DCHECK / similar?
+  if (status_.ok())
+    return DispatchResponse::Success();
+
+  if (status_.IsMessageError())
+    return DispatchResponse::InvalidRequest(status_.Message());
+  return DispatchResponse::ParseError(status_.ToASCIIString());
+}
+
+bool Dispatchable::MaybeParseProperty(cbor::CBORTokenizer* tokenizer) {
+  span<uint8_t> property_name = tokenizer->GetString8();
+  if (SpanEquals(SpanFrom("id"), property_name))
+    return MaybeParseCallId(tokenizer);
+  if (SpanEquals(SpanFrom("method"), property_name))
+    return MaybeParseMethod(tokenizer);
+  if (SpanEquals(SpanFrom("params"), property_name))
+    return MaybeParseParams(tokenizer);
+  if (SpanEquals(SpanFrom("sessionId"), property_name))
+    return MaybeParseSessionId(tokenizer);
+  status_ =
+      Status{Error::MESSAGE_HAS_UNKNOWN_PROPERTY, tokenizer->Status().pos};
+  return false;
+}
+
+bool Dispatchable::MaybeParseCallId(cbor::CBORTokenizer* tokenizer) {
+  if (has_call_id_) {
+    status_ = Status{Error::CBOR_DUPLICATE_MAP_KEY, tokenizer->Status().pos};
+    return false;
+  }
+  tokenizer->Next();
+  if (tokenizer->TokenTag() != cbor::CBORTokenTag::INT32) {
+    status_ = Status{Error::MESSAGE_MUST_HAVE_INTEGER_ID_PROPERTY,
+                     tokenizer->Status().pos};
+    return false;
+  }
+  call_id_ = tokenizer->GetInt32();
+  has_call_id_ = true;
+  tokenizer->Next();
+  return true;
+}
+
+bool Dispatchable::MaybeParseMethod(cbor::CBORTokenizer* tokenizer) {
+  if (!method_.empty()) {
+    status_ = Status{Error::CBOR_DUPLICATE_MAP_KEY, tokenizer->Status().pos};
+    return false;
+  }
+  tokenizer->Next();
+  if (tokenizer->TokenTag() != cbor::CBORTokenTag::STRING8) {
+    status_ = Status{Error::MESSAGE_MUST_HAVE_STRING_METHOD_PROPERTY,
+                     tokenizer->Status().pos};
+    return false;
+  }
+  method_ = tokenizer->GetString8();
+  tokenizer->Next();
+  return true;
+}
+
+bool Dispatchable::MaybeParseParams(cbor::CBORTokenizer* tokenizer) {
+  if (params_seen_) {
+    status_ = Status{Error::CBOR_DUPLICATE_MAP_KEY, tokenizer->Status().pos};
+    return false;
+  }
+  params_seen_ = true;
+  tokenizer->Next();
+  if (tokenizer->TokenTag() == cbor::CBORTokenTag::NULL_VALUE) {
+    tokenizer->Next();
+    return true;
+  }
+  if (tokenizer->TokenTag() != cbor::CBORTokenTag::ENVELOPE) {
+    status_ = Status{Error::MESSAGE_MAY_HAVE_OBJECT_PARAMS_PROPERTY,
+                     tokenizer->Status().pos};
+    return false;
+  }
+  params_ = tokenizer->GetEnvelope();
+  tokenizer->Next();
+  return true;
+}
+
+bool Dispatchable::MaybeParseSessionId(cbor::CBORTokenizer* tokenizer) {
+  if (!session_id_.empty()) {
+    status_ = Status{Error::CBOR_DUPLICATE_MAP_KEY, tokenizer->Status().pos};
+    return false;
+  }
+  tokenizer->Next();
+  if (tokenizer->TokenTag() != cbor::CBORTokenTag::STRING8) {
+    status_ = Status{Error::MESSAGE_MAY_HAVE_STRING_SESSION_ID_PROPERTY,
+                     tokenizer->Status().pos};
+    return false;
+  }
+  session_id_ = tokenizer->GetString8();
+  tokenizer->Next();
+  return true;
+}
+
+namespace {
+class ProtocolError : public Serializable {
+ public:
+  explicit ProtocolError(DispatchResponse dispatch_response)
+      : dispatch_response_(std::move(dispatch_response)) {}
+
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    Status status;
+    std::unique_ptr<ParserHandler> encoder = cbor::NewCBOREncoder(out, &status);
+    encoder->HandleMapBegin();
+    if (has_call_id_) {
+      encoder->HandleString8(SpanFrom("id"));
+      encoder->HandleInt32(call_id_);
+    }
+    encoder->HandleString8(SpanFrom("error"));
+    encoder->HandleMapBegin();
+    encoder->HandleString8(SpanFrom("code"));
+    encoder->HandleInt32(static_cast<int32_t>(dispatch_response_.Code()));
+    encoder->HandleString8(SpanFrom("message"));
+    encoder->HandleString8(SpanFrom(dispatch_response_.Message()));
+    if (!data_.empty()) {
+      encoder->HandleString8(SpanFrom("data"));
+      encoder->HandleString8(SpanFrom(data_));
+    }
+    encoder->HandleMapEnd();
+    encoder->HandleMapEnd();
+    assert(status.ok());
+  }
+
+  void SetCallId(int call_id) {
+    has_call_id_ = true;
+    call_id_ = call_id;
+  }
+  void SetData(std::string data) { data_ = std::move(data); }
+
+ private:
+  const DispatchResponse dispatch_response_;
+  std::string data_;
+  int call_id_ = 0;
+  bool has_call_id_ = false;
+};
+}  // namespace
+
+// =============================================================================
+// Helpers for creating protocol cresponses and notifications.
+// =============================================================================
+
+std::unique_ptr<Serializable> CreateErrorResponse(
+    int call_id,
+    DispatchResponse dispatch_response,
+    const ErrorSupport* errors) {
+  auto protocol_error =
+      std::make_unique<ProtocolError>(std::move(dispatch_response));
+  protocol_error->SetCallId(call_id);
+  if (errors && !errors->Errors().empty()) {
+    protocol_error->SetData(
+        std::string(errors->Errors().begin(), errors->Errors().end()));
+  }
+  return protocol_error;
+}
+
+std::unique_ptr<Serializable> CreateErrorNotification(
+    DispatchResponse dispatch_response) {
+  return std::make_unique<ProtocolError>(std::move(dispatch_response));
+}
+
+namespace {
+class Response : public Serializable {
+ public:
+  Response(int call_id, std::unique_ptr<Serializable> params)
+      : call_id_(call_id), params_(std::move(params)) {}
+
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    Status status;
+    std::unique_ptr<ParserHandler> encoder = cbor::NewCBOREncoder(out, &status);
+    encoder->HandleMapBegin();
+    encoder->HandleString8(SpanFrom("id"));
+    encoder->HandleInt32(call_id_);
+    encoder->HandleString8(SpanFrom("result"));
+    if (params_) {
+      params_->AppendSerialized(out);
+    } else {
+      encoder->HandleMapBegin();
+      encoder->HandleMapEnd();
+    }
+    encoder->HandleMapEnd();
+    assert(status.ok());
+  }
+
+ private:
+  const int call_id_;
+  std::unique_ptr<Serializable> params_;
+};
+
+class Notification : public Serializable {
+ public:
+  Notification(const char* method, std::unique_ptr<Serializable> params)
+      : method_(method), params_(std::move(params)) {}
+
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    Status status;
+    std::unique_ptr<ParserHandler> encoder = cbor::NewCBOREncoder(out, &status);
+    encoder->HandleMapBegin();
+    encoder->HandleString8(SpanFrom("method"));
+    encoder->HandleString8(SpanFrom(method_));
+    encoder->HandleString8(SpanFrom("params"));
+    if (params_) {
+      params_->AppendSerialized(out);
+    } else {
+      encoder->HandleMapBegin();
+      encoder->HandleMapEnd();
+    }
+    encoder->HandleMapEnd();
+    assert(status.ok());
+  }
+
+ private:
+  const char* method_;
+  std::unique_ptr<Serializable> params_;
+};
+}  // namespace
+
+std::unique_ptr<Serializable> CreateResponse(
+    int call_id,
+    std::unique_ptr<Serializable> params) {
+  return std::make_unique<Response>(call_id, std::move(params));
+}
+
+std::unique_ptr<Serializable> CreateNotification(
+    const char* method,
+    std::unique_ptr<Serializable> params) {
+  return std::make_unique<Notification>(method, std::move(params));
+}
+
+// =============================================================================
+// DomainDispatcher - Dispatching betwen protocol methods within a domain.
+// =============================================================================
+DomainDispatcher::WeakPtr::WeakPtr(DomainDispatcher* dispatcher)
+    : dispatcher_(dispatcher) {}
+
+DomainDispatcher::WeakPtr::~WeakPtr() {
+  if (dispatcher_)
+    dispatcher_->weak_ptrs_.erase(this);
+}
+
+DomainDispatcher::Callback::~Callback() = default;
+
+void DomainDispatcher::Callback::dispose() {
+  backend_impl_ = nullptr;
+}
+
+DomainDispatcher::Callback::Callback(
+    std::unique_ptr<DomainDispatcher::WeakPtr> backend_impl,
+    int call_id,
+    span<uint8_t> method,
+    span<uint8_t> message)
+    : backend_impl_(std::move(backend_impl)),
+      call_id_(call_id),
+      method_(method),
+      message_(message.begin(), message.end()) {}
+
+void DomainDispatcher::Callback::sendIfActive(
+    std::unique_ptr<Serializable> partialMessage,
+    const DispatchResponse& response) {
+  if (!backend_impl_ || !backend_impl_->get())
+    return;
+  backend_impl_->get()->sendResponse(call_id_, response,
+                                     std::move(partialMessage));
+  backend_impl_ = nullptr;
+}
+
+void DomainDispatcher::Callback::fallThroughIfActive() {
+  if (!backend_impl_ || !backend_impl_->get())
+    return;
+  backend_impl_->get()->channel()->FallThrough(call_id_, method_,
+                                               SpanFrom(message_));
+  backend_impl_ = nullptr;
+}
+
+DomainDispatcher::DomainDispatcher(FrontendChannel* frontendChannel)
+    : frontend_channel_(frontendChannel) {}
+
+DomainDispatcher::~DomainDispatcher() {
+  clearFrontend();
+}
+
+void DomainDispatcher::sendResponse(int call_id,
+                                    const DispatchResponse& response,
+                                    std::unique_ptr<Serializable> result) {
+  if (!frontend_channel_)
+    return;
+  std::unique_ptr<Serializable> serializable;
+  if (response.IsError()) {
+    serializable = CreateErrorResponse(call_id, response);
+  } else {
+    serializable = CreateResponse(call_id, std::move(result));
+  }
+  frontend_channel_->SendProtocolResponse(call_id, std::move(serializable));
+}
+
+bool DomainDispatcher::MaybeReportInvalidParams(
+    const Dispatchable& dispatchable,
+    const ErrorSupport& errors) {
+  if (errors.Errors().empty())
+    return false;
+  if (frontend_channel_) {
+    frontend_channel_->SendProtocolResponse(
+        dispatchable.CallId(),
+        CreateErrorResponse(
+            dispatchable.CallId(),
+            DispatchResponse::InvalidParams("Invalid parameters"), &errors));
+  }
+  return true;
+}
+
+void DomainDispatcher::clearFrontend() {
+  frontend_channel_ = nullptr;
+  for (auto& weak : weak_ptrs_)
+    weak->dispose();
+  weak_ptrs_.clear();
+}
+
+std::unique_ptr<DomainDispatcher::WeakPtr> DomainDispatcher::weakPtr() {
+  auto weak = std::make_unique<DomainDispatcher::WeakPtr>(this);
+  weak_ptrs_.insert(weak.get());
+  return weak;
+}
+
+// =============================================================================
+// UberDispatcher - dispatches between domains (backends).
+// =============================================================================
+UberDispatcher::DispatchResult::DispatchResult(bool method_found,
+                                               std::function<void()> runnable)
+    : method_found_(method_found), runnable_(runnable) {}
+
+void UberDispatcher::DispatchResult::Run() {
+  if (!runnable_)
+    return;
+  runnable_();
+  runnable_ = nullptr;
+}
+
+UberDispatcher::UberDispatcher(FrontendChannel* frontend_channel)
+    : frontend_channel_(frontend_channel) {
+  assert(frontend_channel);
+}
+
+UberDispatcher::~UberDispatcher() = default;
+
+constexpr size_t kNotFound = std::numeric_limits<size_t>::max();
+
+namespace {
+size_t DotIdx(span<uint8_t> method) {
+  const void* p = memchr(method.data(), '.', method.size());
+  return p ? reinterpret_cast<const uint8_t*>(p) - method.data() : kNotFound;
+}
+}  // namespace
+
+UberDispatcher::DispatchResult UberDispatcher::Dispatch(
+    const Dispatchable& dispatchable) const {
+  span<uint8_t> method = FindByFirst(redirects_, dispatchable.Method(),
+                                     /*default_value=*/dispatchable.Method());
+  size_t dot_idx = DotIdx(method);
+  if (dot_idx != kNotFound) {
+    span<uint8_t> domain = method.subspan(0, dot_idx);
+    span<uint8_t> command = method.subspan(dot_idx + 1);
+    DomainDispatcher* dispatcher = FindByFirst(dispatchers_, domain);
+    if (dispatcher) {
+      std::function<void(const Dispatchable&)> dispatched =
+          dispatcher->Dispatch(command);
+      if (dispatched) {
+        return DispatchResult(
+            true, [dispatchable, dispatched = std::move(dispatched)]() {
+              dispatched(dispatchable);
+            });
+      }
+    }
+  }
+  return DispatchResult(false, [this, dispatchable]() {
+    frontend_channel_->SendProtocolResponse(
+        dispatchable.CallId(),
+        CreateErrorResponse(dispatchable.CallId(),
+                            DispatchResponse::MethodNotFound(
+                                "'" +
+                                std::string(dispatchable.Method().begin(),
+                                            dispatchable.Method().end()) +
+                                "' wasn't found")));
+  });
+}
+
+template <typename T>
+struct FirstLessThan {
+  bool operator()(const std::pair<span<uint8_t>, T>& left,
+                  const std::pair<span<uint8_t>, T>& right) {
+    return SpanLessThan(left.first, right.first);
+  }
+};
+
+void UberDispatcher::WireBackend(
+    span<uint8_t> domain,
+    const std::vector<std::pair<span<uint8_t>, span<uint8_t>>>&
+        sorted_redirects,
+    std::unique_ptr<DomainDispatcher> dispatcher) {
+  auto it = redirects_.insert(redirects_.end(), sorted_redirects.begin(),
+                              sorted_redirects.end());
+  std::inplace_merge(redirects_.begin(), it, redirects_.end(),
+                     FirstLessThan<span<uint8_t>>());
+  auto jt = dispatchers_.insert(dispatchers_.end(),
+                                std::make_pair(domain, std::move(dispatcher)));
+  std::inplace_merge(dispatchers_.begin(), jt, dispatchers_.end(),
+                     FirstLessThan<std::unique_ptr<DomainDispatcher>>());
+}
+
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/dispatch.h b/deps/v8/third_party/inspector_protocol/crdtp/dispatch.h
new file mode 100644
index 0000000000..5253cd87ed
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/dispatch.h
@@ -0,0 +1,311 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CRDTP_DISPATCH_H_
+#define V8_CRDTP_DISPATCH_H_
+
+#include <cassert>
+#include <cstdint>
+#include <functional>
+#include <string>
+#include <unordered_set>
+#include "export.h"
+#include "serializable.h"
+#include "span.h"
+#include "status.h"
+
+namespace v8_crdtp {
+class FrontendChannel;
+class ErrorSupport;
+namespace cbor {
+class CBORTokenizer;
+}  // namespace cbor
+
+// =============================================================================
+// DispatchResponse - Error status and chaining / fall through
+// =============================================================================
+enum class DispatchCode {
+  SUCCESS = 1,
+  FALL_THROUGH = 2,
+  // For historical reasons, these error codes correspond to commonly used
+  // XMLRPC codes (e.g. see METHOD_NOT_FOUND in
+  // https://github.com/python/cpython/blob/master/Lib/xmlrpc/client.py).
+  PARSE_ERROR = -32700,
+  INVALID_REQUEST = -32600,
+  METHOD_NOT_FOUND = -32601,
+  INVALID_PARAMS = -32602,
+  INTERNAL_ERROR = -32603,
+  SERVER_ERROR = -32000,
+};
+
+// Information returned by command handlers. Usually returned after command
+// execution attempts.
+class DispatchResponse {
+ public:
+  const std::string& Message() const { return message_; }
+
+  DispatchCode Code() const { return code_; }
+
+  bool IsSuccess() const { return code_ == DispatchCode::SUCCESS; }
+  bool IsFallThrough() const { return code_ == DispatchCode::FALL_THROUGH; }
+  bool IsError() const { return code_ < DispatchCode::SUCCESS; }
+
+  static DispatchResponse Success();
+  static DispatchResponse FallThrough();
+
+  // Indicates that a message could not be parsed. E.g., malformed JSON.
+  static DispatchResponse ParseError(std::string message);
+
+  // Indicates that a request is lacking required top-level properties
+  // ('id', 'method'), has top-level properties of the wrong type, or has
+  // unknown top-level properties.
+  static DispatchResponse InvalidRequest(std::string message);
+
+  // Indicates that a protocol method such as "Page.bringToFront" could not be
+  // dispatched because it's not known to the (domain) dispatcher.
+  static DispatchResponse MethodNotFound(std::string message);
+
+  // Indicates that the params sent to a domain handler are invalid.
+  static DispatchResponse InvalidParams(std::string message);
+
+  // Used for application level errors, e.g. within protocol agents.
+  static DispatchResponse InternalError();
+
+  // Used for application level errors, e.g. within protocol agents.
+  static DispatchResponse ServerError(std::string message);
+
+ private:
+  DispatchResponse() = default;
+  DispatchCode code_;
+  std::string message_;
+};
+
+// =============================================================================
+// Dispatchable - a shallow parser for CBOR encoded DevTools messages
+// =============================================================================
+
+// This parser extracts only the known top-level fields from a CBOR encoded map;
+// method, id, sessionId, and params.
+class Dispatchable {
+ public:
+  // This constructor parses the |serialized| message. If successful,
+  // |ok()| will yield |true|, and |Method()|, |SessionId()|, |CallId()|,
+  // |Params()| can be used to access, the extracted contents. Otherwise,
+  // |ok()| will yield |false|, and |DispatchError()| can be
+  // used to send a response or notification to the client.
+  explicit Dispatchable(span<uint8_t> serialized);
+
+  // The serialized message that we just parsed.
+  span<uint8_t> Serialized() const { return serialized_; }
+
+  // Yields true if parsing was successful. This is cheaper than calling
+  // ::DispatchError().
+  bool ok() const;
+
+  // If !ok(), returns a DispatchResponse with appropriate code and error
+  // which can be sent to the client as a response or notification.
+  DispatchResponse DispatchError() const;
+
+  // Top level field: the command to be executed, fully qualified by
+  // domain. E.g. "Page.createIsolatedWorld".
+  span<uint8_t> Method() const { return method_; }
+  // Used to identify protocol connections attached to a specific
+  // target. See Target.attachToTarget, Target.setAutoAttach.
+  span<uint8_t> SessionId() const { return session_id_; }
+  // The call id, a sequence number that's used in responses to indicate
+  // the request to which the response belongs.
+  int32_t CallId() const { return call_id_; }
+  bool HasCallId() const { return has_call_id_; }
+  // The payload of the request in CBOR format. The |Dispatchable| parser does
+  // not parse into this; it only provides access to its raw contents here.
+  span<uint8_t> Params() const { return params_; }
+
+ private:
+  bool MaybeParseProperty(cbor::CBORTokenizer* tokenizer);
+  bool MaybeParseCallId(cbor::CBORTokenizer* tokenizer);
+  bool MaybeParseMethod(cbor::CBORTokenizer* tokenizer);
+  bool MaybeParseParams(cbor::CBORTokenizer* tokenizer);
+  bool MaybeParseSessionId(cbor::CBORTokenizer* tokenizer);
+
+  span<uint8_t> serialized_;
+
+  Status status_;
+
+  bool has_call_id_ = false;
+  int32_t call_id_;
+  span<uint8_t> method_;
+  bool params_seen_ = false;
+  span<uint8_t> params_;
+  span<uint8_t> session_id_;
+};
+
+// =============================================================================
+// Helpers for creating protocol cresponses and notifications.
+// =============================================================================
+
+// The resulting notifications can be sent to a protocol client,
+// usually via a FrontendChannel (see frontend_channel.h).
+
+std::unique_ptr<Serializable> CreateErrorResponse(
+    int callId,
+    DispatchResponse dispatch_response,
+    const ErrorSupport* errors = nullptr);
+
+std::unique_ptr<Serializable> CreateErrorNotification(
+    DispatchResponse dispatch_response);
+
+std::unique_ptr<Serializable> CreateResponse(
+    int callId,
+    std::unique_ptr<Serializable> params);
+
+std::unique_ptr<Serializable> CreateNotification(
+    const char* method,
+    std::unique_ptr<Serializable> params = nullptr);
+
+// =============================================================================
+// DomainDispatcher - Dispatching betwen protocol methods within a domain.
+// =============================================================================
+
+// This class is subclassed by |DomainDispatcherImpl|, which we generate per
+// DevTools domain. It contains routines called from the generated code,
+// e.g. ::MaybeReportInvalidParams, which are optimized for small code size.
+// The most important method is ::Dispatch, which implements method dispatch
+// by command name lookup.
+class DomainDispatcher {
+ public:
+  class WeakPtr {
+   public:
+    explicit WeakPtr(DomainDispatcher*);
+    ~WeakPtr();
+    DomainDispatcher* get() { return dispatcher_; }
+    void dispose() { dispatcher_ = nullptr; }
+
+   private:
+    DomainDispatcher* dispatcher_;
+  };
+
+  class Callback {
+   public:
+    virtual ~Callback();
+    void dispose();
+
+   protected:
+    // |method| must point at static storage (a C++ string literal in practice).
+    Callback(std::unique_ptr<WeakPtr> backend_impl,
+             int call_id,
+             span<uint8_t> method,
+             span<uint8_t> message);
+
+    void sendIfActive(std::unique_ptr<Serializable> partialMessage,
+                      const DispatchResponse& response);
+    void fallThroughIfActive();
+
+   private:
+    std::unique_ptr<WeakPtr> backend_impl_;
+    int call_id_;
+    // Subclasses of this class are instantiated from generated code which
+    // passes a string literal for the method name to the constructor. So the
+    // storage for |method| is the binary of the running process.
+    span<uint8_t> method_;
+    std::vector<uint8_t> message_;
+  };
+
+  explicit DomainDispatcher(FrontendChannel*);
+  virtual ~DomainDispatcher();
+
+  // Given a |command_name| without domain qualification, looks up the
+  // corresponding method. If the method is not found, returns nullptr.
+  // Otherwise, Returns a closure that will parse the provided
+  // Dispatchable.params() to a protocol object and execute the
+  // apprpropriate method. If the parsing fails it will issue an
+  // error response on the frontend channel, otherwise it will execute the
+  // command.
+  virtual std::function<void(const Dispatchable&)> Dispatch(
+      span<uint8_t> command_name) = 0;
+
+  // Sends a response to the client via the channel.
+  void sendResponse(int call_id,
+                    const DispatchResponse&,
+                    std::unique_ptr<Serializable> result = nullptr);
+
+  // Returns true if |errors| contains errors *and* reports these errors
+  // as a response on the frontend channel. Called from generated code,
+  // optimized for code size of the callee.
+  bool MaybeReportInvalidParams(const Dispatchable& dispatchable,
+                                const ErrorSupport& errors);
+
+  FrontendChannel* channel() { return frontend_channel_; }
+
+  void clearFrontend();
+
+  std::unique_ptr<WeakPtr> weakPtr();
+
+ private:
+  FrontendChannel* frontend_channel_;
+  std::unordered_set<WeakPtr*> weak_ptrs_;
+};
+
+// =============================================================================
+// UberDispatcher - dispatches between domains (backends).
+// =============================================================================
+class UberDispatcher {
+ public:
+  // Return type for ::Dispatch.
+  class DispatchResult {
+   public:
+    DispatchResult(bool method_found, std::function<void()> runnable);
+
+    // Indicates whether the method was found, that is, it could be dispatched
+    // to a backend registered with this dispatcher.
+    bool MethodFound() const { return method_found_; }
+
+    // Runs the dispatched result. This will send the appropriate error
+    // responses if the method wasn't found or if something went wrong during
+    // parameter parsing.
+    void Run();
+
+   private:
+    bool method_found_;
+    std::function<void()> runnable_;
+  };
+
+  // |frontend_hannel| can't be nullptr.
+  explicit UberDispatcher(FrontendChannel* frontend_channel);
+  virtual ~UberDispatcher();
+
+  // Dispatches the provided |dispatchable| considering all redirects and domain
+  // handlers registered with this uber dispatcher. Also see |DispatchResult|.
+  // |dispatchable.ok()| must hold - callers must check this separately and
+  // deal with errors.
+  DispatchResult Dispatch(const Dispatchable& dispatchable) const;
+
+  // Invoked from generated code for wiring domain backends; that is,
+  // connecting domain handlers to an uber dispatcher.
+  // See <domain-namespace>::Dispatcher::Wire(UberDispatcher*,Backend*).
+  FrontendChannel* channel() const {
+    assert(frontend_channel_);
+    return frontend_channel_;
+  }
+
+  // Invoked from generated code for wiring domain backends; that is,
+  // connecting domain handlers to an uber dispatcher.
+  // See <domain-namespace>::Dispatcher::Wire(UberDispatcher*,Backend*).
+  void WireBackend(span<uint8_t> domain,
+                   const std::vector<std::pair<span<uint8_t>, span<uint8_t>>>&,
+                   std::unique_ptr<DomainDispatcher> dispatcher);
+
+ private:
+  DomainDispatcher* findDispatcher(span<uint8_t> method);
+  FrontendChannel* const frontend_channel_;
+  // Pairs of ascii strings of the form ("Domain1.method1","Domain2.method2")
+  // indicating that the first element of each pair redirects to the second.
+  // Sorted by first element.
+  std::vector<std::pair<span<uint8_t>, span<uint8_t>>> redirects_;
+  // Domain dispatcher instances, sorted by their domain name.
+  std::vector<std::pair<span<uint8_t>, std::unique_ptr<DomainDispatcher>>>
+      dispatchers_;
+};
+}  // namespace v8_crdtp
+
+#endif  // V8_CRDTP_DISPATCH_H_
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/dispatch_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/dispatch_test.cc
new file mode 100644
index 0000000000..846ec08c0d
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/dispatch_test.cc
@@ -0,0 +1,445 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <vector>
+
+#include "cbor.h"
+#include "dispatch.h"
+#include "error_support.h"
+#include "frontend_channel.h"
+#include "json.h"
+#include "test_platform.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// DispatchResponse - Error status and chaining / fall through
+// =============================================================================
+TEST(DispatchResponseTest, OK) {
+  EXPECT_EQ(DispatchCode::SUCCESS, DispatchResponse::Success().Code());
+  EXPECT_TRUE(DispatchResponse::Success().IsSuccess());
+}
+
+TEST(DispatchResponseTest, ServerError) {
+  DispatchResponse error = DispatchResponse::ServerError("Oops!");
+  EXPECT_FALSE(error.IsSuccess());
+  EXPECT_EQ(DispatchCode::SERVER_ERROR, error.Code());
+  EXPECT_EQ("Oops!", error.Message());
+}
+
+TEST(DispatchResponseTest, InternalError) {
+  DispatchResponse error = DispatchResponse::InternalError();
+  EXPECT_FALSE(error.IsSuccess());
+  EXPECT_EQ(DispatchCode::INTERNAL_ERROR, error.Code());
+  EXPECT_EQ("Internal error", error.Message());
+}
+
+TEST(DispatchResponseTest, InvalidParams) {
+  DispatchResponse error = DispatchResponse::InvalidParams("too cool");
+  EXPECT_FALSE(error.IsSuccess());
+  EXPECT_EQ(DispatchCode::INVALID_PARAMS, error.Code());
+  EXPECT_EQ("too cool", error.Message());
+}
+
+TEST(DispatchResponseTest, FallThrough) {
+  DispatchResponse error = DispatchResponse::FallThrough();
+  EXPECT_FALSE(error.IsSuccess());
+  EXPECT_TRUE(error.IsFallThrough());
+  EXPECT_EQ(DispatchCode::FALL_THROUGH, error.Code());
+}
+
+// =============================================================================
+// Dispatchable - a shallow parser for CBOR encoded DevTools messages
+// =============================================================================
+TEST(DispatchableTest, MessageMustBeAnObject) {
+  // Provide no input whatsoever.
+  span<uint8_t> empty_span;
+  Dispatchable empty(empty_span);
+  EXPECT_FALSE(empty.ok());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, empty.DispatchError().Code());
+  EXPECT_EQ("Message must be an object", empty.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMustHaveIntegerIdProperty) {
+  // Construct an empty map inside of an envelope.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom("{}"), &cbor).ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_FALSE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message must have integer 'id' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMustHaveIntegerIdProperty_IncorrectType) {
+  // This time we set the id property, but fail to make it an int32.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(
+      json::ConvertJSONToCBOR(SpanFrom("{\"id\":\"foo\"}"), &cbor).ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_FALSE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message must have integer 'id' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMustHaveStringMethodProperty) {
+  // This time we set the id property, but not the method property.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom("{\"id\":42}"), &cbor).ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message must have string 'method' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMustHaveStringMethodProperty_IncorrectType) {
+  // This time we set the method property, but fail to make it a string.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(
+      json::ConvertJSONToCBOR(SpanFrom("{\"id\":42,\"method\":42}"), &cbor)
+          .ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message must have string 'method' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMayHaveStringSessionIdProperty) {
+  // This time, the session id is an int but it should be a string. Method and
+  // call id are present.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(json::ConvertJSONToCBOR(
+                  SpanFrom("{\"id\":42,\"method\":\"Foo.executeBar\","
+                           "\"sessionId\":42"  // int32 is wrong type
+                           "}"),
+                  &cbor)
+                  .ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message may have string 'sessionId' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageMayHaveObjectParamsProperty) {
+  // This time, we fail to use the correct type for the params property.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(json::ConvertJSONToCBOR(
+                  SpanFrom("{\"id\":42,\"method\":\"Foo.executeBar\","
+                           "\"params\":42"  // int32 is wrong type
+                           "}"),
+                  &cbor)
+                  .ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ("Message may have object 'params' property",
+            dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, MessageWithUnknownProperty) {
+  // This time we set the 'unknown' property, so we are told what's allowed.
+  std::vector<uint8_t> cbor;
+  ASSERT_TRUE(
+      json::ConvertJSONToCBOR(SpanFrom("{\"id\":42,\"unknown\":42}"), &cbor)
+          .ok());
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(DispatchCode::INVALID_REQUEST, dispatchable.DispatchError().Code());
+  EXPECT_EQ(
+      "Message has property other than 'id', 'method', 'sessionId', 'params'",
+      dispatchable.DispatchError().Message());
+}
+
+TEST(DispatchableTest, DuplicateMapKey) {
+  for (const std::string& json :
+       {"{\"id\":42,\"id\":42}", "{\"params\":null,\"params\":null}",
+        "{\"method\":\"foo\",\"method\":\"foo\"}",
+        "{\"sessionId\":\"42\",\"sessionId\":\"42\"}"}) {
+    SCOPED_TRACE("json = " + json);
+    std::vector<uint8_t> cbor;
+    ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom(json), &cbor).ok());
+    Dispatchable dispatchable(SpanFrom(cbor));
+    EXPECT_FALSE(dispatchable.ok());
+    EXPECT_EQ(DispatchCode::PARSE_ERROR, dispatchable.DispatchError().Code());
+    EXPECT_THAT(dispatchable.DispatchError().Message(),
+                testing::StartsWith("CBOR: duplicate map key at position "));
+  }
+}
+
+TEST(DispatchableTest, ValidMessageParsesOK_NoParams) {
+  for (const std::string& json :
+       {"{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":"
+        "\"f421ssvaz4\"}",
+        "{\"id\":42,\"method\":\"Foo.executeBar\",\"sessionId\":\"f421ssvaz4\","
+        "\"params\":null}"}) {
+    SCOPED_TRACE("json = " + json);
+    std::vector<uint8_t> cbor;
+    ASSERT_TRUE(json::ConvertJSONToCBOR(SpanFrom(json), &cbor).ok());
+    Dispatchable dispatchable(SpanFrom(cbor));
+    EXPECT_TRUE(dispatchable.ok());
+    EXPECT_TRUE(dispatchable.HasCallId());
+    EXPECT_EQ(42, dispatchable.CallId());
+    EXPECT_EQ("Foo.executeBar", std::string(dispatchable.Method().begin(),
+                                            dispatchable.Method().end()));
+    EXPECT_EQ("f421ssvaz4", std::string(dispatchable.SessionId().begin(),
+                                        dispatchable.SessionId().end()));
+    EXPECT_TRUE(dispatchable.Params().empty());
+  }
+}
+
+TEST(DispatchableTest, ValidMessageParsesOK_WithParams) {
+  std::vector<uint8_t> cbor;
+  cbor::EnvelopeEncoder envelope;
+  envelope.EncodeStart(&cbor);
+  cbor.push_back(cbor::EncodeIndefiniteLengthMapStart());
+  cbor::EncodeString8(SpanFrom("id"), &cbor);
+  cbor::EncodeInt32(42, &cbor);
+  cbor::EncodeString8(SpanFrom("method"), &cbor);
+  cbor::EncodeString8(SpanFrom("Foo.executeBar"), &cbor);
+  cbor::EncodeString8(SpanFrom("params"), &cbor);
+  cbor::EnvelopeEncoder params_envelope;
+  params_envelope.EncodeStart(&cbor);
+  // The |Dispatchable| class does not parse into the "params" envelope,
+  // so we can stick anything into there for the purpose of this test.
+  // For convenience, we use a String8.
+  cbor::EncodeString8(SpanFrom("params payload"), &cbor);
+  params_envelope.EncodeStop(&cbor);
+  cbor::EncodeString8(SpanFrom("sessionId"), &cbor);
+  cbor::EncodeString8(SpanFrom("f421ssvaz4"), &cbor);
+  cbor.push_back(cbor::EncodeStop());
+  envelope.EncodeStop(&cbor);
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_TRUE(dispatchable.ok());
+  EXPECT_TRUE(dispatchable.HasCallId());
+  EXPECT_EQ(42, dispatchable.CallId());
+  EXPECT_EQ("Foo.executeBar", std::string(dispatchable.Method().begin(),
+                                          dispatchable.Method().end()));
+  EXPECT_EQ("f421ssvaz4", std::string(dispatchable.SessionId().begin(),
+                                      dispatchable.SessionId().end()));
+  cbor::CBORTokenizer params_tokenizer(dispatchable.Params());
+  ASSERT_EQ(cbor::CBORTokenTag::ENVELOPE, params_tokenizer.TokenTag());
+  params_tokenizer.EnterEnvelope();
+  ASSERT_EQ(cbor::CBORTokenTag::STRING8, params_tokenizer.TokenTag());
+  EXPECT_EQ("params payload", std::string(params_tokenizer.GetString8().begin(),
+                                          params_tokenizer.GetString8().end()));
+}
+
+TEST(DispatchableTest, FaultyCBORTrailingJunk) {
+  // In addition to the higher level parsing errors, we also catch CBOR
+  // structural corruption. E.g., in this case, the message would be
+  // OK but has some extra trailing bytes.
+  std::vector<uint8_t> cbor;
+  cbor::EnvelopeEncoder envelope;
+  envelope.EncodeStart(&cbor);
+  cbor.push_back(cbor::EncodeIndefiniteLengthMapStart());
+  cbor::EncodeString8(SpanFrom("id"), &cbor);
+  cbor::EncodeInt32(42, &cbor);
+  cbor::EncodeString8(SpanFrom("method"), &cbor);
+  cbor::EncodeString8(SpanFrom("Foo.executeBar"), &cbor);
+  cbor::EncodeString8(SpanFrom("sessionId"), &cbor);
+  cbor::EncodeString8(SpanFrom("f421ssvaz4"), &cbor);
+  cbor.push_back(cbor::EncodeStop());
+  envelope.EncodeStop(&cbor);
+  size_t trailing_junk_pos = cbor.size();
+  cbor.push_back('t');
+  cbor.push_back('r');
+  cbor.push_back('a');
+  cbor.push_back('i');
+  cbor.push_back('l');
+  Dispatchable dispatchable(SpanFrom(cbor));
+  EXPECT_FALSE(dispatchable.ok());
+  EXPECT_EQ(DispatchCode::PARSE_ERROR, dispatchable.DispatchError().Code());
+  EXPECT_EQ(56u, trailing_junk_pos);
+  EXPECT_EQ("CBOR: trailing junk at position 56",
+            dispatchable.DispatchError().Message());
+}
+
+// =============================================================================
+// Helpers for creating protocol cresponses and notifications.
+// =============================================================================
+TEST(CreateErrorResponseTest, SmokeTest) {
+  ErrorSupport errors;
+  errors.Push();
+  errors.SetName("foo");
+  errors.Push();
+  errors.SetName("bar");
+  errors.AddError("expected a string");
+  errors.SetName("baz");
+  errors.AddError("expected a surprise");
+  auto serializable = CreateErrorResponse(
+      42, DispatchResponse::InvalidParams("invalid params message"), &errors);
+  std::string json;
+  auto status =
+      json::ConvertCBORToJSON(SpanFrom(serializable->Serialize()), &json);
+  ASSERT_TRUE(status.ok());
+  EXPECT_EQ(
+      "{\"id\":42,\"error\":"
+      "{\"code\":-32602,"
+      "\"message\":\"invalid params message\","
+      "\"data\":\"foo.bar: expected a string; "
+      "foo.baz: expected a surprise\"}}",
+      json);
+}
+
+TEST(CreateErrorNotificationTest, SmokeTest) {
+  auto serializable =
+      CreateErrorNotification(DispatchResponse::InvalidRequest("oops!"));
+  std::string json;
+  auto status =
+      json::ConvertCBORToJSON(SpanFrom(serializable->Serialize()), &json);
+  ASSERT_TRUE(status.ok());
+  EXPECT_EQ("{\"error\":{\"code\":-32600,\"message\":\"oops!\"}}", json);
+}
+
+TEST(CreateResponseTest, SmokeTest) {
+  auto serializable = CreateResponse(42, nullptr);
+  std::string json;
+  auto status =
+      json::ConvertCBORToJSON(SpanFrom(serializable->Serialize()), &json);
+  ASSERT_TRUE(status.ok());
+  EXPECT_EQ("{\"id\":42,\"result\":{}}", json);
+}
+
+TEST(CreateNotificationTest, SmokeTest) {
+  auto serializable = CreateNotification("Foo.bar");
+  std::string json;
+  auto status =
+      json::ConvertCBORToJSON(SpanFrom(serializable->Serialize()), &json);
+  ASSERT_TRUE(status.ok());
+  EXPECT_EQ("{\"method\":\"Foo.bar\",\"params\":{}}", json);
+}
+
+// =============================================================================
+// UberDispatcher - dispatches between domains (backends).
+// =============================================================================
+class TestChannel : public FrontendChannel {
+ public:
+  std::string JSON() const {
+    std::string json;
+    json::ConvertCBORToJSON(SpanFrom(cbor_), &json);
+    return json;
+  }
+
+ private:
+  void SendProtocolResponse(int call_id,
+                            std::unique_ptr<Serializable> message) override {
+    cbor_ = message->Serialize();
+  }
+
+  void SendProtocolNotification(
+      std::unique_ptr<Serializable> message) override {
+    cbor_ = message->Serialize();
+  }
+
+  void FallThrough(int call_id,
+                   span<uint8_t> method,
+                   span<uint8_t> message) override {}
+
+  void FlushProtocolNotifications() override {}
+
+  std::vector<uint8_t> cbor_;
+};
+
+TEST(UberDispatcherTest, MethodNotFound) {
+  // No domain dispatchers are registered, so unsuprisingly, we'll get a method
+  // not found error and can see that DispatchResult::MethodFound() yields
+  // false.
+  TestChannel channel;
+  UberDispatcher dispatcher(&channel);
+  std::vector<uint8_t> message;
+  json::ConvertJSONToCBOR(SpanFrom("{\"id\":42,\"method\":\"Foo.bar\"}"),
+                          &message);
+  Dispatchable dispatchable(SpanFrom(message));
+  ASSERT_TRUE(dispatchable.ok());
+  UberDispatcher::DispatchResult dispatched = dispatcher.Dispatch(dispatchable);
+  EXPECT_FALSE(dispatched.MethodFound());
+  dispatched.Run();
+  EXPECT_EQ(
+      "{\"id\":42,\"error\":"
+      "{\"code\":-32601,\"message\":\"'Foo.bar' wasn't found\"}}",
+      channel.JSON());
+}
+
+// A domain dispatcher which captured dispatched and executed commands in fields
+// for testing.
+class TestDomain : public DomainDispatcher {
+ public:
+  explicit TestDomain(FrontendChannel* channel) : DomainDispatcher(channel) {}
+
+  std::function<void(const Dispatchable&)> Dispatch(
+      span<uint8_t> command_name) override {
+    dispatched_commands_.push_back(
+        std::string(command_name.begin(), command_name.end()));
+    return [this](const Dispatchable& dispatchable) {
+      executed_commands_.push_back(dispatchable.CallId());
+    };
+  }
+
+  // Command names of the dispatched commands.
+  std::vector<std::string> DispatchedCommands() const {
+    return dispatched_commands_;
+  }
+
+  // Call ids of the executed commands.
+  std::vector<int32_t> ExecutedCommands() const { return executed_commands_; }
+
+ private:
+  std::vector<std::string> dispatched_commands_;
+  std::vector<int32_t> executed_commands_;
+};
+
+TEST(UberDispatcherTest, DispatchingToDomainWithRedirects) {
+  // This time, we register two domain dispatchers (Foo and Bar) and issue one
+  // command 'Foo.execute' which executes on Foo and one command 'Foo.redirect'
+  // which executes as 'Bar.redirected'.
+  TestChannel channel;
+  UberDispatcher dispatcher(&channel);
+  auto foo_dispatcher = std::make_unique<TestDomain>(&channel);
+  TestDomain* foo = foo_dispatcher.get();
+  auto bar_dispatcher = std::make_unique<TestDomain>(&channel);
+  TestDomain* bar = bar_dispatcher.get();
+
+  dispatcher.WireBackend(
+      SpanFrom("Foo"), {{SpanFrom("Foo.redirect"), SpanFrom("Bar.redirected")}},
+      std::move(foo_dispatcher));
+  dispatcher.WireBackend(SpanFrom("Bar"), {}, std::move(bar_dispatcher));
+
+  {
+    std::vector<uint8_t> message;
+    json::ConvertJSONToCBOR(SpanFrom("{\"id\":42,\"method\":\"Foo.execute\"}"),
+                            &message);
+    Dispatchable dispatchable(SpanFrom(message));
+    ASSERT_TRUE(dispatchable.ok());
+    UberDispatcher::DispatchResult dispatched =
+        dispatcher.Dispatch(dispatchable);
+    EXPECT_TRUE(dispatched.MethodFound());
+    dispatched.Run();
+  }
+  {
+    std::vector<uint8_t> message;
+    json::ConvertJSONToCBOR(SpanFrom("{\"id\":43,\"method\":\"Foo.redirect\"}"),
+                            &message);
+    Dispatchable dispatchable(SpanFrom(message));
+    ASSERT_TRUE(dispatchable.ok());
+    UberDispatcher::DispatchResult dispatched =
+        dispatcher.Dispatch(dispatchable);
+    EXPECT_TRUE(dispatched.MethodFound());
+    dispatched.Run();
+  }
+  EXPECT_THAT(foo->DispatchedCommands(), testing::ElementsAre("execute"));
+  EXPECT_THAT(foo->ExecutedCommands(), testing::ElementsAre(42));
+  EXPECT_THAT(bar->DispatchedCommands(), testing::ElementsAre("redirected"));
+  EXPECT_THAT(bar->ExecutedCommands(), testing::ElementsAre(43));
+}
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/error_support.cc b/deps/v8/third_party/inspector_protocol/crdtp/error_support.cc
new file mode 100644
index 0000000000..6fc6a033d5
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/error_support.cc
@@ -0,0 +1,59 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "error_support.h"
+
+#include <cassert>
+
+namespace v8_crdtp {
+
+void ErrorSupport::Push() {
+  stack_.emplace_back();
+}
+
+void ErrorSupport::Pop() {
+  stack_.pop_back();
+}
+
+void ErrorSupport::SetName(const char* name) {
+  assert(!stack_.empty());
+  stack_.back().type = NAME;
+  stack_.back().name = name;
+}
+
+void ErrorSupport::SetIndex(size_t index) {
+  assert(!stack_.empty());
+  stack_.back().type = INDEX;
+  stack_.back().index = index;
+}
+
+void ErrorSupport::AddError(const char* error) {
+  assert(!stack_.empty());
+  if (!errors_.empty())
+    errors_ += "; ";
+  for (size_t ii = 0; ii < stack_.size(); ++ii) {
+    if (ii)
+      errors_ += ".";
+    const Segment& s = stack_[ii];
+    switch (s.type) {
+      case NAME:
+        errors_ += s.name;
+        continue;
+      case INDEX:
+        errors_ += std::to_string(s.index);
+        continue;
+      default:
+        assert(s.type != EMPTY);
+        continue;
+    }
+  }
+  errors_ += ": ";
+  errors_ += error;
+}
+
+span<uint8_t> ErrorSupport::Errors() const {
+  return SpanFrom(errors_);
+}
+
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/error_support.h b/deps/v8/third_party/inspector_protocol/crdtp/error_support.h
new file mode 100644
index 0000000000..34e2ce2118
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/error_support.h
@@ -0,0 +1,62 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CRDTP_ERROR_SUPPORT_H_
+#define V8_CRDTP_ERROR_SUPPORT_H_
+
+#include <cstdint>
+#include <string>
+#include <vector>
+#include "export.h"
+#include "span.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// ErrorSupport - For tracking errors in tree structures.
+// =============================================================================
+
+// This abstraction is used when converting between Values and inspector
+// objects, e.g. in lib/ValueConversions_{h,cc}.template. As the processing
+// enters and exits a branch, we call Push / Pop. Within the branch,
+// we either set the name or an index (in case we're processing the element of a
+// list/vector). Only once an error is seen, the path which is now on the
+// stack is materialized and prefixes the error message. E.g.,
+// "foo.bar.2: some error". After error collection, ::Errors() is used to
+// access the message.
+class ErrorSupport {
+ public:
+  // Push / Pop operations for the path segments; after Push, either SetName or
+  // SetIndex must be called exactly once.
+  void Push();
+  void Pop();
+
+  // Sets the name of the current segment on the stack; e.g. a field name.
+  // |name| must be a C++ string literal in 7 bit US-ASCII.
+  void SetName(const char* name);
+  // Sets the index of the current segment on the stack; e.g. an array index.
+  void SetIndex(size_t index);
+
+  // Materializes the error internally. |error| must be a C++ string literal
+  // in 7 bit US-ASCII.
+  void AddError(const char* error);
+
+  // Returns the semicolon-separated list of errors as in 7 bit ASCII.
+  span<uint8_t> Errors() const;
+
+ private:
+  enum SegmentType { EMPTY, NAME, INDEX };
+  struct Segment {
+    SegmentType type = EMPTY;
+    union {
+      const char* name;
+      size_t index;
+    };
+  };
+  std::vector<Segment> stack_;
+  std::string errors_;
+};
+
+}  // namespace v8_crdtp
+
+#endif  // V8_CRDTP_ERROR_SUPPORT_H_
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/error_support_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/error_support_test.cc
new file mode 100644
index 0000000000..f7c075d6e7
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/error_support_test.cc
@@ -0,0 +1,45 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "error_support.h"
+
+#include <string>
+#include <vector>
+
+#include "test_platform.h"
+
+namespace v8_crdtp {
+TEST(ErrorSupportTest, Empty) {
+  ErrorSupport errors;
+  EXPECT_TRUE(errors.Errors().empty());
+}
+
+TEST(ErrorSupportTest, Nesting) {
+  ErrorSupport errors;
+  // Enter field foo, inter element at index 42, enter field bar, and encounter
+  // an error there ("something wrong").
+  errors.Push();
+  errors.SetName("foo");
+  errors.Push();
+  errors.SetIndex(42);
+  errors.Push();
+  errors.SetName("bar_sibling");
+  errors.SetName("bar");
+  errors.AddError("something wrong");
+  errors.Pop();  // bar
+  errors.Pop();  // 42
+  // The common case is actually that we'll enter some field, set the name
+  // or index, and leave without ever producing an error.
+  errors.Push();
+  errors.SetName("no_error_here");
+  errors.Pop();  // no_error_here
+  errors.Push();
+  errors.SetName("bang");
+  errors.AddError("one last error");
+  errors.Pop();  // bang
+  errors.Pop();  // foo
+  std::string out(errors.Errors().begin(), errors.Errors().end());
+  EXPECT_EQ("foo.42.bar: something wrong; foo.bang: one last error", out);
+}
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/find_by_first.h b/deps/v8/third_party/inspector_protocol/crdtp/find_by_first.h
new file mode 100644
index 0000000000..ae42241413
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/find_by_first.h
@@ -0,0 +1,58 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CRDTP_FIND_BY_FIRST_H_
+#define V8_CRDTP_FIND_BY_FIRST_H_
+
+#include <algorithm>
+#include <cstdint>
+#include <memory>
+#include <vector>
+
+#include "export.h"
+#include "span.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// FindByFirst - Retrieval from a sorted vector that's keyed by span<uint8_t>.
+// =============================================================================
+
+// Given a vector of pairs sorted by the first element of each pair, find
+// the corresponding value given a key to be compared to the first element.
+// Together with std::inplace_merge and pre-sorting or std::sort, this can
+// be used to implement a minimalistic equivalent of Chromium's flat_map.
+
+// In this variant, the template parameter |T| is a value type and a
+// |default_value| is provided.
+template <typename T>
+T FindByFirst(const std::vector<std::pair<span<uint8_t>, T>>& sorted_by_first,
+              span<uint8_t> key,
+              T default_value) {
+  auto it = std::lower_bound(
+      sorted_by_first.begin(), sorted_by_first.end(), key,
+      [](const std::pair<span<uint8_t>, T>& left, span<uint8_t> right) {
+        return SpanLessThan(left.first, right);
+      });
+  return (it != sorted_by_first.end() && SpanEquals(it->first, key))
+             ? it->second
+             : default_value;
+}
+
+// In this variant, the template parameter |T| is a class or struct that's
+// instantiated in std::unique_ptr, and we return either a T* or a nullptr.
+template <typename T>
+T* FindByFirst(const std::vector<std::pair<span<uint8_t>, std::unique_ptr<T>>>&
+                   sorted_by_first,
+               span<uint8_t> key) {
+  auto it = std::lower_bound(
+      sorted_by_first.begin(), sorted_by_first.end(), key,
+      [](const std::pair<span<uint8_t>, std::unique_ptr<T>>& left,
+         span<uint8_t> right) { return SpanLessThan(left.first, right); });
+  return (it != sorted_by_first.end() && SpanEquals(it->first, key))
+             ? it->second.get()
+             : nullptr;
+}
+}  // namespace v8_crdtp
+
+#endif  // V8_CRDTP_FIND_BY_FIRST_H_
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/find_by_first_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/find_by_first_test.cc
new file mode 100644
index 0000000000..67d5114869
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/find_by_first_test.cc
@@ -0,0 +1,76 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <string>
+
+#include "find_by_first.h"
+#include "test_platform.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// FindByFirst - Efficient retrieval from a sorted vector.
+// =============================================================================
+TEST(FindByFirst, SpanBySpan) {
+  std::vector<std::pair<span<uint8_t>, span<uint8_t>>> sorted_span_by_span = {
+      {SpanFrom("foo1"), SpanFrom("bar1")},
+      {SpanFrom("foo2"), SpanFrom("bar2")},
+      {SpanFrom("foo3"), SpanFrom("bar3")},
+  };
+  {
+    auto result = FindByFirst(sorted_span_by_span, SpanFrom("foo1"),
+                              SpanFrom("not_found"));
+    EXPECT_EQ("bar1", std::string(result.begin(), result.end()));
+  }
+  {
+    auto result = FindByFirst(sorted_span_by_span, SpanFrom("foo3"),
+                              SpanFrom("not_found"));
+    EXPECT_EQ("bar3", std::string(result.begin(), result.end()));
+  }
+  {
+    auto result = FindByFirst(sorted_span_by_span, SpanFrom("baz"),
+                              SpanFrom("not_found"));
+    EXPECT_EQ("not_found", std::string(result.begin(), result.end()));
+  }
+}
+
+namespace {
+class TestObject {
+ public:
+  explicit TestObject(const std::string& message) : message_(message) {}
+
+  const std::string& message() const { return message_; }
+
+ private:
+  std::string message_;
+};
+}  // namespace
+
+TEST(FindByFirst, ObjectBySpan) {
+  std::vector<std::pair<span<uint8_t>, std::unique_ptr<TestObject>>>
+      sorted_object_by_span;
+  sorted_object_by_span.push_back(
+      std::make_pair(SpanFrom("foo1"), std::make_unique<TestObject>("bar1")));
+  sorted_object_by_span.push_back(
+      std::make_pair(SpanFrom("foo2"), std::make_unique<TestObject>("bar2")));
+  sorted_object_by_span.push_back(
+      std::make_pair(SpanFrom("foo3"), std::make_unique<TestObject>("bar3")));
+  {
+    TestObject* result =
+        FindByFirst<TestObject>(sorted_object_by_span, SpanFrom("foo1"));
+    ASSERT_TRUE(result);
+    ASSERT_EQ("bar1", result->message());
+  }
+  {
+    TestObject* result =
+        FindByFirst<TestObject>(sorted_object_by_span, SpanFrom("foo3"));
+    ASSERT_TRUE(result);
+    ASSERT_EQ("bar3", result->message());
+  }
+  {
+    TestObject* result =
+        FindByFirst<TestObject>(sorted_object_by_span, SpanFrom("baz"));
+    ASSERT_FALSE(result);
+  }
+}
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/frontend_channel.h b/deps/v8/third_party/inspector_protocol/crdtp/frontend_channel.h
new file mode 100644
index 0000000000..eba8b2acbd
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/frontend_channel.h
@@ -0,0 +1,47 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_CRDTP_FRONTEND_CHANNEL_H_
+#define V8_CRDTP_FRONTEND_CHANNEL_H_
+
+#include <cstdint>
+#include <memory>
+#include "export.h"
+#include "serializable.h"
+#include "span.h"
+
+namespace v8_crdtp {
+// =============================================================================
+// FrontendChannel - For sending notifications and responses to protocol clients
+// =============================================================================
+class FrontendChannel {
+ public:
+  virtual ~FrontendChannel() = default;
+
+  // Sends protocol responses and notifications. The |call_id| parameter is
+  // seemingly redundant because it's also included in the message, but
+  // responses may be sent from an untrusted source to a trusted process (e.g.
+  // from Chromium's renderer (blink) to the browser process), which needs
+  // to be able to match the response to an earlier request without parsing the
+  // messsage.
+  virtual void SendProtocolResponse(int call_id,
+                                    std::unique_ptr<Serializable> message) = 0;
+  virtual void SendProtocolNotification(
+      std::unique_ptr<Serializable> message) = 0;
+
+  // FallThrough indicates that |message| should be handled in another layer.
+  // Usually this means the layer responding to the message didn't handle it,
+  // but in some cases messages are handled by multiple layers (e.g. both
+  // the embedder and the content layer in Chromium).
+  virtual void FallThrough(int call_id,
+                           span<uint8_t> method,
+                           span<uint8_t> message) = 0;
+
+  // Session implementations may queue notifications for performance or
+  // other considerations; this is a hook for domain handlers to manually flush.
+  virtual void FlushProtocolNotifications() = 0;
+};
+}  // namespace v8_crdtp
+
+#endif  // V8_CRDTP_FRONTEND_CHANNEL_H_
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/json.cc b/deps/v8/third_party/inspector_protocol/crdtp/json.cc
index 6701951881..0cf46aeda5 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/json.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/json.cc
@@ -285,7 +285,22 @@ class JSONEncoder : public ParserHandler {
       Emit("null");
       return;
     }
+    // If |value| is a scalar, emit it as an int. Taken from json_writer.cc in
+    // Chromium.
+    if (value <= std::numeric_limits<int64_t>::max() &&
+        value >= std::numeric_limits<int64_t>::min() &&
+        std::floor(value) == value) {
+      Emit(std::to_string(static_cast<int64_t>(value)));
+      return;
+    }
     std::string str_value = json::platform::DToStr(value);
+    // The following is somewhat paranoid, but also taken from json_writer.cc
+    // in Chromium:
+    // Ensure that the number has a .0 if there's no decimal or 'e'.  This
+    // makes sure that when we read the JSON back, it's interpreted as a
+    // real rather than an int.
+    if (str_value.find_first_of(".eE") == std::string::npos)
+      str_value.append(".0");
 
     // DToStr may fail to emit a 0 before the decimal dot. E.g. this is
     // the case in base::NumberToString in Chromium (which is based on
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/json.h b/deps/v8/third_party/inspector_protocol/crdtp/json.h
index fa8522771f..63fce408bd 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/json.h
+++ b/deps/v8/third_party/inspector_protocol/crdtp/json.h
@@ -6,6 +6,7 @@
 #define V8_CRDTP_JSON_H_
 
 #include <memory>
+#include <vector>
 #include "export.h"
 #include "parser_handler.h"
 
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/json_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/json_test.cc
index d8742463de..eb6c3579aa 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/json_test.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/json_test.cc
@@ -184,6 +184,32 @@ TEST(JsonStdStringWriterTest, HelloWorld) {
       out);
 }
 
+TEST(JsonStdStringWriterTest, ScalarsAreRenderedAsInt) {
+  // Test that Number.MIN_SAFE_INTEGER / Number.MAX_SAFE_INTEGER from Javascript
+  // are rendered as integers (no decimal point / rounding), even when we
+  // encode them from double. Javascript's Number is an IEE754 double, so
+  // it has 53 bits to represent integers.
+  std::string out;
+  Status status;
+  std::unique_ptr<ParserHandler> writer = NewJSONEncoder(&out, &status);
+  writer->HandleMapBegin();
+
+  writer->HandleString8(SpanFrom("Number.MIN_SAFE_INTEGER"));
+  EXPECT_EQ(-0x1fffffffffffff, -9007199254740991);  // 53 bits for integers.
+  writer->HandleDouble(-9007199254740991);          // Note HandleDouble here.
+
+  writer->HandleString8(SpanFrom("Number.MAX_SAFE_INTEGER"));
+  EXPECT_EQ(0x1fffffffffffff, 9007199254740991);  // 53 bits for integers.
+  writer->HandleDouble(9007199254740991);         // Note HandleDouble here.
+
+  writer->HandleMapEnd();
+  EXPECT_TRUE(status.ok());
+  EXPECT_EQ(
+      "{\"Number.MIN_SAFE_INTEGER\":-9007199254740991,"
+      "\"Number.MAX_SAFE_INTEGER\":9007199254740991}",
+      out);
+}
+
 TEST(JsonStdStringWriterTest, RepresentingNonFiniteValuesAsNull) {
   // JSON can't represent +Infinity, -Infinity, or NaN.
   // So in practice it's mapped to null.
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/serializable.cc b/deps/v8/third_party/inspector_protocol/crdtp/serializable.cc
index 1df9eb291d..20de53ecc0 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/serializable.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/serializable.cc
@@ -9,9 +9,28 @@ namespace v8_crdtp {
 // Serializable - An object to be emitted as a sequence of bytes.
 // =============================================================================
 
-std::vector<uint8_t> Serializable::TakeSerialized() && {
+std::vector<uint8_t> Serializable::Serialize() const {
   std::vector<uint8_t> out;
   AppendSerialized(&out);
   return out;
 }
+
+namespace {
+class PreSerialized : public Serializable {
+ public:
+  explicit PreSerialized(std::vector<uint8_t> bytes) : bytes_(bytes) {}
+
+  void AppendSerialized(std::vector<uint8_t>* out) const override {
+    out->insert(out->end(), bytes_.begin(), bytes_.end());
+  }
+
+ private:
+  std::vector<uint8_t> bytes_;
+};
+}  // namespace
+
+// static
+std::unique_ptr<Serializable> Serializable::From(std::vector<uint8_t> bytes) {
+  return std::make_unique<PreSerialized>(std::move(bytes));
+}
 }  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/serializable.h b/deps/v8/third_party/inspector_protocol/crdtp/serializable.h
index 57faf42316..66386711b0 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/serializable.h
+++ b/deps/v8/third_party/inspector_protocol/crdtp/serializable.h
@@ -6,6 +6,7 @@
 #define V8_CRDTP_SERIALIZABLE_H_
 
 #include <cstdint>
+#include <memory>
 #include <vector>
 #include "export.h"
 
@@ -13,17 +14,18 @@ namespace v8_crdtp {
 // =============================================================================
 // Serializable - An object to be emitted as a sequence of bytes.
 // =============================================================================
-
 class Serializable {
  public:
-  // The default implementation invokes AppendSerialized with an empty vector
-  // and returns it; some subclasses may override and move out internal state
-  // instead to avoid copying.
-  virtual std::vector<uint8_t> TakeSerialized() &&;
+  // Convenience: Invokes |AppendSerialized| on an empty vector.
+  std::vector<uint8_t> Serialize() const;
 
   virtual void AppendSerialized(std::vector<uint8_t>* out) const = 0;
 
   virtual ~Serializable() = default;
+
+  // Wraps a vector of |bytes| into a Serializable for situations in which we
+  // eagerly serialize a structure.
+  static std::unique_ptr<Serializable> From(std::vector<uint8_t> bytes);
 };
 }  // namespace v8_crdtp
 
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/serializable_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/serializable_test.cc
index da49f17517..d28ca69edd 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/serializable_test.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/serializable_test.cc
@@ -14,8 +14,7 @@ namespace v8_crdtp {
 // =============================================================================
 
 namespace {
-// Tests the default behavior for ::TakeSerialized (to invoke
-// ::AppendSerialized).
+// Tests ::Serialize (which invokes ::AppendSerialized).
 class SimpleExample : public Serializable {
  public:
   explicit SimpleExample(const std::vector<uint8_t>& contents)
@@ -36,6 +35,6 @@ TEST(SerializableTest, YieldsContents) {
   foo.AppendSerialized(&contents);  // Yields contents by appending.
   EXPECT_THAT(contents, testing::ElementsAre(1, 2, 3, 1, 2, 3));
   // Yields contents by returning.
-  EXPECT_THAT(std::move(foo).TakeSerialized(), testing::ElementsAre(1, 2, 3));
+  EXPECT_THAT(foo.Serialize(), testing::ElementsAre(1, 2, 3));
 }
 }  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/span.cc b/deps/v8/third_party/inspector_protocol/crdtp/span.cc
new file mode 100644
index 0000000000..af30bb4fd9
--- /dev/null
+++ b/deps/v8/third_party/inspector_protocol/crdtp/span.cc
@@ -0,0 +1,24 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "span.h"
+
+#include <algorithm>
+
+namespace v8_crdtp {
+
+bool SpanLessThan(span<uint8_t> x, span<uint8_t> y) noexcept {
+  auto min_size = std::min(x.size(), y.size());
+  const int r = min_size == 0 ? 0 : memcmp(x.data(), y.data(), min_size);
+  return (r < 0) || (r == 0 && x.size() < y.size());
+}
+
+bool SpanEquals(span<uint8_t> x, span<uint8_t> y) noexcept {
+  auto len = x.size();
+  if (len != y.size())
+    return false;
+  return x.data() == y.data() || len == 0 ||
+         std::memcmp(x.data(), y.data(), len) == 0;
+}
+}  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/span.h b/deps/v8/third_party/inspector_protocol/crdtp/span.h
index cb94319d5f..ace5b511f6 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/span.h
+++ b/deps/v8/third_party/inspector_protocol/crdtp/span.h
@@ -5,11 +5,11 @@
 #ifndef V8_CRDTP_SPAN_H_
 #define V8_CRDTP_SPAN_H_
 
-#include <algorithm>
 #include <cstdint>
 #include <cstring>
 #include <string>
-#include <vector>
+
+#include "export.h"
 
 namespace v8_crdtp {
 // =============================================================================
@@ -76,19 +76,15 @@ inline span<typename C::value_type> SpanFrom(const C& v) {
 
 // Less than / equality comparison functions for sorting / searching for byte
 // spans. These are similar to absl::string_view's < and == operators.
-constexpr inline bool SpanLessThan(span<uint8_t> x, span<uint8_t> y) noexcept {
-  auto min_size = std::min(x.size(), y.size());
-  const int r = min_size == 0 ? 0 : memcmp(x.data(), y.data(), min_size);
-  return (r < 0) || (r == 0 && x.size() < y.size());
-}
+bool SpanLessThan(span<uint8_t> x, span<uint8_t> y) noexcept;
 
-constexpr inline bool SpanEquals(span<uint8_t> x, span<uint8_t> y) noexcept {
-  auto len = x.size();
-  if (len != y.size())
-    return false;
-  return x.data() == y.data() || len == 0 ||
-         std::memcmp(x.data(), y.data(), len) == 0;
-}
+bool SpanEquals(span<uint8_t> x, span<uint8_t> y) noexcept;
+
+struct SpanLt {
+  bool operator()(span<uint8_t> l, span<uint8_t> r) const {
+    return SpanLessThan(l, r);
+  }
+};
 }  // namespace v8_crdtp
 
 #endif  // V8_CRDTP_SPAN_H_
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/span_test.cc b/deps/v8/third_party/inspector_protocol/crdtp/span_test.cc
index 718f03f885..0f31e5a6ba 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/span_test.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/span_test.cc
@@ -4,7 +4,6 @@
 
 #include <cstdlib>
 #include <string>
-#include <unordered_map>
 
 #include "span.h"
 #include "test_platform.h"
@@ -13,7 +12,6 @@ namespace v8_crdtp {
 // =============================================================================
 // span - sequence of bytes
 // =============================================================================
-
 template <typename T>
 class SpanTest : public ::testing::Test {};
 
@@ -108,41 +106,4 @@ TEST(SpanComparisons, ByteWiseLexicographicalOrder) {
   EXPECT_FALSE(SpanLessThan(SpanFrom(msg), SpanFrom(lesser_msg)));
   EXPECT_FALSE(SpanEquals(SpanFrom(msg), SpanFrom(lesser_msg)));
 }
-
-// TODO(johannes): The following shows how the span can be used in an
-// std::unordered_map as a key. Once we have a production usage, we'll move
-// SpanHash, SpanEq, SpanHasher into the header.
-
-// A simple hash code, inspired by http://stackoverflow.com/q/1646807.
-constexpr inline size_t SpanHash(span<uint8_t> s) noexcept {
-  size_t hash = 17;
-  for (uint8_t c : s)
-    hash = 31 * hash + c;
-  return hash;
-}
-
-// Structs for making std::unordered_map with std::span<uint8_t> keys.
-struct SpanEq {
-  constexpr inline bool operator()(span<uint8_t> l, span<uint8_t> r) const {
-    return SpanEquals(l, r);
-  }
-};
-
-struct SpanHasher {
-  constexpr inline size_t operator()(span<uint8_t> s) const {
-    return SpanHash(s);
-  }
-};
-
-TEST(SpanHasherAndSpanEq, SpanAsKeyInUnorderedMap) {
-  // A very simple smoke test for unordered_map, storing three key/value pairs.
-  std::unordered_map<span<uint8_t>, int32_t, SpanHasher, SpanEq> a_map;
-  a_map[SpanFrom("foo")] = 1;
-  a_map[SpanFrom("bar")] = 2;
-  a_map[SpanFrom("baz")] = 3;
-  EXPECT_EQ(3u, a_map.size());
-  EXPECT_EQ(1, a_map[SpanFrom("foo")]);
-  EXPECT_EQ(2, a_map[SpanFrom("bar")]);
-  EXPECT_EQ(3, a_map[SpanFrom("baz")]);
-}
 }  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/status.cc b/deps/v8/third_party/inspector_protocol/crdtp/status.cc
index 57cb795985..4a8e03d389 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/status.cc
+++ b/deps/v8/third_party/inspector_protocol/crdtp/status.cc
@@ -9,100 +9,118 @@ namespace v8_crdtp {
 // Status and Error codes
 // =============================================================================
 
-std::string Status::ToASCIIString() const {
+std::string Status::Message() const {
   switch (error) {
     case Error::OK:
       return "OK";
     case Error::JSON_PARSER_UNPROCESSED_INPUT_REMAINS:
-      return ToASCIIString("JSON: unprocessed input remains");
+      return "JSON: unprocessed input remains";
     case Error::JSON_PARSER_STACK_LIMIT_EXCEEDED:
-      return ToASCIIString("JSON: stack limit exceeded");
+      return "JSON: stack limit exceeded";
     case Error::JSON_PARSER_NO_INPUT:
-      return ToASCIIString("JSON: no input");
+      return "JSON: no input";
     case Error::JSON_PARSER_INVALID_TOKEN:
-      return ToASCIIString("JSON: invalid token");
+      return "JSON: invalid token";
     case Error::JSON_PARSER_INVALID_NUMBER:
-      return ToASCIIString("JSON: invalid number");
+      return "JSON: invalid number";
     case Error::JSON_PARSER_INVALID_STRING:
-      return ToASCIIString("JSON: invalid string");
+      return "JSON: invalid string";
     case Error::JSON_PARSER_UNEXPECTED_ARRAY_END:
-      return ToASCIIString("JSON: unexpected array end");
+      return "JSON: unexpected array end";
     case Error::JSON_PARSER_COMMA_OR_ARRAY_END_EXPECTED:
-      return ToASCIIString("JSON: comma or array end expected");
+      return "JSON: comma or array end expected";
     case Error::JSON_PARSER_STRING_LITERAL_EXPECTED:
-      return ToASCIIString("JSON: string literal expected");
+      return "JSON: string literal expected";
     case Error::JSON_PARSER_COLON_EXPECTED:
-      return ToASCIIString("JSON: colon expected");
+      return "JSON: colon expected";
     case Error::JSON_PARSER_UNEXPECTED_MAP_END:
-      return ToASCIIString("JSON: unexpected map end");
+      return "JSON: unexpected map end";
     case Error::JSON_PARSER_COMMA_OR_MAP_END_EXPECTED:
-      return ToASCIIString("JSON: comma or map end expected");
+      return "JSON: comma or map end expected";
     case Error::JSON_PARSER_VALUE_EXPECTED:
-      return ToASCIIString("JSON: value expected");
+      return "JSON: value expected";
 
     case Error::CBOR_INVALID_INT32:
-      return ToASCIIString("CBOR: invalid int32");
+      return "CBOR: invalid int32";
     case Error::CBOR_INVALID_DOUBLE:
-      return ToASCIIString("CBOR: invalid double");
+      return "CBOR: invalid double";
     case Error::CBOR_INVALID_ENVELOPE:
-      return ToASCIIString("CBOR: invalid envelope");
+      return "CBOR: invalid envelope";
     case Error::CBOR_ENVELOPE_CONTENTS_LENGTH_MISMATCH:
-      return ToASCIIString("CBOR: envelope contents length mismatch");
+      return "CBOR: envelope contents length mismatch";
     case Error::CBOR_MAP_OR_ARRAY_EXPECTED_IN_ENVELOPE:
-      return ToASCIIString("CBOR: map or array expected in envelope");
+      return "CBOR: map or array expected in envelope";
     case Error::CBOR_INVALID_STRING8:
-      return ToASCIIString("CBOR: invalid string8");
+      return "CBOR: invalid string8";
     case Error::CBOR_INVALID_STRING16:
-      return ToASCIIString("CBOR: invalid string16");
+      return "CBOR: invalid string16";
     case Error::CBOR_INVALID_BINARY:
-      return ToASCIIString("CBOR: invalid binary");
+      return "CBOR: invalid binary";
     case Error::CBOR_UNSUPPORTED_VALUE:
-      return ToASCIIString("CBOR: unsupported value");
+      return "CBOR: unsupported value";
     case Error::CBOR_NO_INPUT:
-      return ToASCIIString("CBOR: no input");
+      return "CBOR: no input";
     case Error::CBOR_INVALID_START_BYTE:
-      return ToASCIIString("CBOR: invalid start byte");
+      return "CBOR: invalid start byte";
     case Error::CBOR_UNEXPECTED_EOF_EXPECTED_VALUE:
-      return ToASCIIString("CBOR: unexpected eof expected value");
+      return "CBOR: unexpected eof expected value";
     case Error::CBOR_UNEXPECTED_EOF_IN_ARRAY:
-      return ToASCIIString("CBOR: unexpected eof in array");
+      return "CBOR: unexpected eof in array";
     case Error::CBOR_UNEXPECTED_EOF_IN_MAP:
-      return ToASCIIString("CBOR: unexpected eof in map");
+      return "CBOR: unexpected eof in map";
     case Error::CBOR_INVALID_MAP_KEY:
-      return ToASCIIString("CBOR: invalid map key");
+      return "CBOR: invalid map key";
+    case Error::CBOR_DUPLICATE_MAP_KEY:
+      return "CBOR: duplicate map key";
     case Error::CBOR_STACK_LIMIT_EXCEEDED:
-      return ToASCIIString("CBOR: stack limit exceeded");
+      return "CBOR: stack limit exceeded";
     case Error::CBOR_TRAILING_JUNK:
-      return ToASCIIString("CBOR: trailing junk");
+      return "CBOR: trailing junk";
     case Error::CBOR_MAP_START_EXPECTED:
-      return ToASCIIString("CBOR: map start expected");
+      return "CBOR: map start expected";
     case Error::CBOR_MAP_STOP_EXPECTED:
-      return ToASCIIString("CBOR: map stop expected");
+      return "CBOR: map stop expected";
     case Error::CBOR_ARRAY_START_EXPECTED:
-      return ToASCIIString("CBOR: array start expected");
+      return "CBOR: array start expected";
     case Error::CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED:
-      return ToASCIIString("CBOR: envelope size limit exceeded");
+      return "CBOR: envelope size limit exceeded";
+
+    case Error::MESSAGE_MUST_BE_AN_OBJECT:
+      return "Message must be an object";
+    case Error::MESSAGE_MUST_HAVE_INTEGER_ID_PROPERTY:
+      return "Message must have integer 'id' property";
+    case Error::MESSAGE_MUST_HAVE_STRING_METHOD_PROPERTY:
+      return "Message must have string 'method' property";
+    case Error::MESSAGE_MAY_HAVE_STRING_SESSION_ID_PROPERTY:
+      return "Message may have string 'sessionId' property";
+    case Error::MESSAGE_MAY_HAVE_OBJECT_PARAMS_PROPERTY:
+      return "Message may have object 'params' property";
+    case Error::MESSAGE_HAS_UNKNOWN_PROPERTY:
+      return "Message has property other than "
+             "'id', 'method', 'sessionId', 'params'";
 
     case Error::BINDINGS_MANDATORY_FIELD_MISSING:
-      return ToASCIIString("BINDINGS: mandatory field missing");
+      return "BINDINGS: mandatory field missing";
     case Error::BINDINGS_BOOL_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: bool value expected");
+      return "BINDINGS: bool value expected";
     case Error::BINDINGS_INT32_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: int32 value expected");
+      return "BINDINGS: int32 value expected";
     case Error::BINDINGS_DOUBLE_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: double value expected");
+      return "BINDINGS: double value expected";
     case Error::BINDINGS_STRING_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: string value expected");
+      return "BINDINGS: string value expected";
     case Error::BINDINGS_STRING8_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: string8 value expected");
+      return "BINDINGS: string8 value expected";
     case Error::BINDINGS_BINARY_VALUE_EXPECTED:
-      return ToASCIIString("BINDINGS: binary value expected");
+      return "BINDINGS: binary value expected";
   }
   // Some compilers can't figure out that we can't get here.
   return "INVALID ERROR CODE";
 }
 
-std::string Status::ToASCIIString(const char* msg) const {
-  return std::string(msg) + " at position " + std::to_string(pos);
+std::string Status::ToASCIIString() const {
+  if (ok())
+    return "OK";
+  return Message() + " at position " + std::to_string(pos);
 }
 }  // namespace v8_crdtp
diff --git a/deps/v8/third_party/inspector_protocol/crdtp/status.h b/deps/v8/third_party/inspector_protocol/crdtp/status.h
index bf75615c09..ebb8ec98c0 100644
--- a/deps/v8/third_party/inspector_protocol/crdtp/status.h
+++ b/deps/v8/third_party/inspector_protocol/crdtp/status.h
@@ -18,7 +18,9 @@ namespace v8_crdtp {
 
 enum class Error {
   OK = 0,
-  // JSON parsing errors - json_parser.{h,cc}.
+
+  // JSON parsing errors; checked when parsing / converting from JSON.
+  // See json.{h,cc}.
   JSON_PARSER_UNPROCESSED_INPUT_REMAINS = 0x01,
   JSON_PARSER_STACK_LIMIT_EXCEEDED = 0x02,
   JSON_PARSER_NO_INPUT = 0x03,
@@ -33,6 +35,7 @@ enum class Error {
   JSON_PARSER_COMMA_OR_MAP_END_EXPECTED = 0x0c,
   JSON_PARSER_VALUE_EXPECTED = 0x0d,
 
+  // CBOR parsing errors; checked when parsing / converting from CBOR.
   CBOR_INVALID_INT32 = 0x0e,
   CBOR_INVALID_DOUBLE = 0x0f,
   CBOR_INVALID_ENVELOPE = 0x10,
@@ -48,20 +51,31 @@ enum class Error {
   CBOR_UNEXPECTED_EOF_IN_ARRAY = 0x1a,
   CBOR_UNEXPECTED_EOF_IN_MAP = 0x1b,
   CBOR_INVALID_MAP_KEY = 0x1c,
-  CBOR_STACK_LIMIT_EXCEEDED = 0x1d,
-  CBOR_TRAILING_JUNK = 0x1e,
-  CBOR_MAP_START_EXPECTED = 0x1f,
-  CBOR_MAP_STOP_EXPECTED = 0x20,
-  CBOR_ARRAY_START_EXPECTED = 0x21,
-  CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED = 0x22,
-
-  BINDINGS_MANDATORY_FIELD_MISSING = 0x23,
-  BINDINGS_BOOL_VALUE_EXPECTED = 0x24,
-  BINDINGS_INT32_VALUE_EXPECTED = 0x25,
-  BINDINGS_DOUBLE_VALUE_EXPECTED = 0x26,
-  BINDINGS_STRING_VALUE_EXPECTED = 0x27,
-  BINDINGS_STRING8_VALUE_EXPECTED = 0x28,
-  BINDINGS_BINARY_VALUE_EXPECTED = 0x29,
+  CBOR_DUPLICATE_MAP_KEY = 0x1d,
+  CBOR_STACK_LIMIT_EXCEEDED = 0x1e,
+  CBOR_TRAILING_JUNK = 0x1f,
+  CBOR_MAP_START_EXPECTED = 0x20,
+  CBOR_MAP_STOP_EXPECTED = 0x21,
+  CBOR_ARRAY_START_EXPECTED = 0x22,
+  CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED = 0x23,
+
+  // Message errors are constraints we place on protocol messages coming
+  // from a protocol client; these are checked in crdtp::Dispatchable
+  // (see dispatch.h) as it performs a shallow parse.
+  MESSAGE_MUST_BE_AN_OBJECT = 0x24,
+  MESSAGE_MUST_HAVE_INTEGER_ID_PROPERTY = 0x25,
+  MESSAGE_MUST_HAVE_STRING_METHOD_PROPERTY = 0x26,
+  MESSAGE_MAY_HAVE_STRING_SESSION_ID_PROPERTY = 0x27,
+  MESSAGE_MAY_HAVE_OBJECT_PARAMS_PROPERTY = 0x28,
+  MESSAGE_HAS_UNKNOWN_PROPERTY = 0x29,
+
+  BINDINGS_MANDATORY_FIELD_MISSING = 0x30,
+  BINDINGS_BOOL_VALUE_EXPECTED = 0x31,
+  BINDINGS_INT32_VALUE_EXPECTED = 0x32,
+  BINDINGS_DOUBLE_VALUE_EXPECTED = 0x33,
+  BINDINGS_STRING_VALUE_EXPECTED = 0x34,
+  BINDINGS_STRING8_VALUE_EXPECTED = 0x35,
+  BINDINGS_BINARY_VALUE_EXPECTED = 0x36,
 };
 
 // A status value with position that can be copied. The default status
@@ -76,12 +90,18 @@ struct Status {
   Status(Error error, size_t pos) : error(error), pos(pos) {}
   Status() = default;
 
-  // Returns a 7 bit US-ASCII string, either "OK" or an error message
-  // that includes the position.
-  std::string ToASCIIString() const;
+  bool IsMessageError() const {
+    return error >= Error::MESSAGE_MUST_BE_AN_OBJECT &&
+           error <= Error::MESSAGE_HAS_UNKNOWN_PROPERTY;
+  }
+
+  // Returns 7 bit US-ASCII string, either "OK" or an error message without
+  // position.
+  std::string Message() const;
 
- private:
-  std::string ToASCIIString(const char* msg) const;
+  // Returns a 7 bit US-ASCII string, either "OK" or an error message that
+  // includes the position.
+  std::string ToASCIIString() const;
 };
 }  // namespace v8_crdtp
 
diff --git a/deps/v8/third_party/inspector_protocol/inspector_protocol.gni b/deps/v8/third_party/inspector_protocol/inspector_protocol.gni
index 6e83e87d2a..f4823847df 100644
--- a/deps/v8/third_party/inspector_protocol/inspector_protocol.gni
+++ b/deps/v8/third_party/inspector_protocol/inspector_protocol.gni
@@ -33,16 +33,9 @@ template("inspector_protocol_generate") {
       invoker.config_file,
       "$inspector_protocol_dir/lib/base_string_adapter_cc.template",
       "$inspector_protocol_dir/lib/base_string_adapter_h.template",
-      "$inspector_protocol_dir/lib/DispatcherBase_cpp.template",
-      "$inspector_protocol_dir/lib/DispatcherBase_h.template",
-      "$inspector_protocol_dir/lib/ErrorSupport_cpp.template",
-      "$inspector_protocol_dir/lib/ErrorSupport_h.template",
       "$inspector_protocol_dir/lib/Forward_h.template",
-      "$inspector_protocol_dir/lib/FrontendChannel_h.template",
       "$inspector_protocol_dir/lib/Object_cpp.template",
       "$inspector_protocol_dir/lib/Object_h.template",
-      "$inspector_protocol_dir/lib/Parser_cpp.template",
-      "$inspector_protocol_dir/lib/Parser_h.template",
       "$inspector_protocol_dir/lib/Protocol_cpp.template",
       "$inspector_protocol_dir/lib/ValueConversions_h.template",
       "$inspector_protocol_dir/lib/Values_cpp.template",
@@ -58,7 +51,9 @@ template("inspector_protocol_generate") {
 
     args = [
       "--jinja_dir",
-      rebase_path("//third_party/", root_build_dir),  # jinja is in chromium's third_party
+      rebase_path("//third_party/", root_build_dir),  # jinja is in chromium's
+                                                      # third_party
+
       "--output_base",
       rebase_path(invoker.out_dir, root_build_dir),
       "--config",
diff --git a/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_cpp.template b/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_cpp.template
deleted file mode 100644
index 52aa4977a9..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_cpp.template
+++ /dev/null
@@ -1,355 +0,0 @@
-// This file is generated by DispatcherBase_cpp.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-//#include "DispatcherBase.h"
-//#include "Parser.h"
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-// static
-DispatchResponse DispatchResponse::OK()
-{
-    DispatchResponse result;
-    result.m_status = kSuccess;
-    result.m_errorCode = kParseError;
-    return result;
-}
-
-// static
-DispatchResponse DispatchResponse::Error(const String& error)
-{
-    DispatchResponse result;
-    result.m_status = kError;
-    result.m_errorCode = kServerError;
-    result.m_errorMessage = error;
-    return result;
-}
-
-// static
-DispatchResponse DispatchResponse::InternalError()
-{
-    DispatchResponse result;
-    result.m_status = kError;
-    result.m_errorCode = kInternalError;
-    result.m_errorMessage = "Internal error";
-    return result;
-}
-
-// static
-DispatchResponse DispatchResponse::InvalidParams(const String& error)
-{
-    DispatchResponse result;
-    result.m_status = kError;
-    result.m_errorCode = kInvalidParams;
-    result.m_errorMessage = error;
-    return result;
-}
-
-// static
-DispatchResponse DispatchResponse::FallThrough()
-{
-    DispatchResponse result;
-    result.m_status = kFallThrough;
-    result.m_errorCode = kParseError;
-    return result;
-}
-
-// static
-const char DispatcherBase::kInvalidParamsString[] = "Invalid parameters";
-
-DispatcherBase::WeakPtr::WeakPtr(DispatcherBase* dispatcher) : m_dispatcher(dispatcher) { }
-
-DispatcherBase::WeakPtr::~WeakPtr()
-{
-    if (m_dispatcher)
-        m_dispatcher->m_weakPtrs.erase(this);
-}
-
-DispatcherBase::Callback::Callback(std::unique_ptr<DispatcherBase::WeakPtr> backendImpl, int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message)
-    : m_backendImpl(std::move(backendImpl))
-    , m_callId(callId)
-    , m_method(method)
-    , m_message(message.begin(), message.end()) { }
-
-DispatcherBase::Callback::~Callback() = default;
-
-void DispatcherBase::Callback::dispose()
-{
-    m_backendImpl = nullptr;
-}
-
-void DispatcherBase::Callback::sendIfActive(std::unique_ptr<protocol::DictionaryValue> partialMessage, const DispatchResponse& response)
-{
-    if (!m_backendImpl || !m_backendImpl->get())
-        return;
-    m_backendImpl->get()->sendResponse(m_callId, response, std::move(partialMessage));
-    m_backendImpl = nullptr;
-}
-
-void DispatcherBase::Callback::fallThroughIfActive()
-{
-    if (!m_backendImpl || !m_backendImpl->get())
-        return;
-    m_backendImpl->get()->channel()->fallThrough(m_callId, m_method, {{config.crdtp.namespace}}::SpanFrom(m_message));
-    m_backendImpl = nullptr;
-}
-
-DispatcherBase::DispatcherBase(FrontendChannel* frontendChannel)
-    : m_frontendChannel(frontendChannel) { }
-
-DispatcherBase::~DispatcherBase()
-{
-    clearFrontend();
-}
-
-void DispatcherBase::sendResponse(int callId, const DispatchResponse& response, std::unique_ptr<protocol::DictionaryValue> result)
-{
-    if (!m_frontendChannel)
-        return;
-    if (response.status() == DispatchResponse::kError) {
-        reportProtocolError(callId, response.errorCode(), response.errorMessage(), nullptr);
-        return;
-    }
-    m_frontendChannel->sendProtocolResponse(callId, InternalResponse::createResponse(callId, std::move(result)));
-}
-
-void DispatcherBase::sendResponse(int callId, const DispatchResponse& response)
-{
-    sendResponse(callId, response, DictionaryValue::create());
-}
-
-namespace {
-
-class ProtocolError : public Serializable {
-public:
-    static std::unique_ptr<ProtocolError> createErrorResponse(int callId, DispatchResponse::ErrorCode code, const String& errorMessage, ErrorSupport* errors)
-    {
-        std::unique_ptr<ProtocolError> protocolError(new ProtocolError(code, errorMessage));
-        protocolError->m_callId = callId;
-        protocolError->m_hasCallId = true;
-        if (errors && errors->hasErrors())
-            protocolError->m_data = errors->errors();
-        return protocolError;
-    }
-
-    static std::unique_ptr<ProtocolError> createErrorNotification(DispatchResponse::ErrorCode code, const String& errorMessage)
-    {
-        return std::unique_ptr<ProtocolError>(new ProtocolError(code, errorMessage));
-    }
-
-    void AppendSerialized(std::vector<uint8_t>* out) const override
-    {
-        toDictionary()->AppendSerialized(out);
-    }
-
-    ~ProtocolError() override {}
-
-private:
-    ProtocolError(DispatchResponse::ErrorCode code, const String& errorMessage)
-        : m_code(code)
-        , m_errorMessage(errorMessage)
-    {
-    }
-
-    std::unique_ptr<DictionaryValue> toDictionary() const {
-        std::unique_ptr<protocol::DictionaryValue> error = DictionaryValue::create();
-        error->setInteger("code", m_code);
-        error->setString("message", m_errorMessage);
-        if (m_data.length())
-            error->setString("data", m_data);
-        std::unique_ptr<protocol::DictionaryValue> message = DictionaryValue::create();
-        message->setObject("error", std::move(error));
-        if (m_hasCallId)
-            message->setInteger("id", m_callId);
-        return message;
-    }
-
-    DispatchResponse::ErrorCode m_code;
-    String m_errorMessage;
-    String m_data;
-    int m_callId = 0;
-    bool m_hasCallId = false;
-};
-
-} // namespace
-
-static void reportProtocolErrorTo(FrontendChannel* frontendChannel, int callId, DispatchResponse::ErrorCode code, const String& errorMessage, ErrorSupport* errors)
-{
-    if (frontendChannel)
-        frontendChannel->sendProtocolResponse(callId, ProtocolError::createErrorResponse(callId, code, errorMessage, errors));
-}
-
-static void reportProtocolErrorTo(FrontendChannel* frontendChannel, DispatchResponse::ErrorCode code, const String& errorMessage)
-{
-    if (frontendChannel)
-        frontendChannel->sendProtocolNotification(ProtocolError::createErrorNotification(code, errorMessage));
-}
-
-void DispatcherBase::reportProtocolError(int callId, DispatchResponse::ErrorCode code, const String& errorMessage, ErrorSupport* errors)
-{
-    reportProtocolErrorTo(m_frontendChannel, callId, code, errorMessage, errors);
-}
-
-void DispatcherBase::clearFrontend()
-{
-    m_frontendChannel = nullptr;
-    for (auto& weak : m_weakPtrs)
-        weak->dispose();
-    m_weakPtrs.clear();
-}
-
-std::unique_ptr<DispatcherBase::WeakPtr> DispatcherBase::weakPtr()
-{
-    std::unique_ptr<DispatcherBase::WeakPtr> weak(new DispatcherBase::WeakPtr(this));
-    m_weakPtrs.insert(weak.get());
-    return weak;
-}
-
-UberDispatcher::UberDispatcher(FrontendChannel* frontendChannel)
-    : m_frontendChannel(frontendChannel) { }
-
-void UberDispatcher::registerBackend(const String& name, std::unique_ptr<protocol::DispatcherBase> dispatcher)
-{
-    m_dispatchers[name] = std::move(dispatcher);
-}
-
-void UberDispatcher::setupRedirects(const std::unordered_map<String, String>& redirects)
-{
-    for (const auto& pair : redirects)
-        m_redirects[pair.first] = pair.second;
-}
-
-bool UberDispatcher::parseCommand(Value* parsedMessage, int* outCallId, String* outMethod) {
-    if (!parsedMessage) {
-        reportProtocolErrorTo(m_frontendChannel, DispatchResponse::kParseError, "Message must be a valid JSON");
-        return false;
-    }
-    protocol::DictionaryValue* messageObject = DictionaryValue::cast(parsedMessage);
-    if (!messageObject) {
-        reportProtocolErrorTo(m_frontendChannel, DispatchResponse::kInvalidRequest, "Message must be an object");
-        return false;
-    }
-
-    int callId = 0;
-    protocol::Value* callIdValue = messageObject->get("id");
-    bool success = callIdValue && callIdValue->asInteger(&callId);
-    if (!success) {
-        reportProtocolErrorTo(m_frontendChannel, DispatchResponse::kInvalidRequest, "Message must have integer 'id' property");
-        return false;
-    }
-    if (outCallId)
-      *outCallId = callId;
-
-    protocol::Value* methodValue = messageObject->get("method");
-    String method;
-    success = methodValue && methodValue->asString(&method);
-    if (!success) {
-        reportProtocolErrorTo(m_frontendChannel, callId, DispatchResponse::kInvalidRequest, "Message must have string 'method' property", nullptr);
-        return false;
-    }
-    if (outMethod)
-      *outMethod = method;
-    return true;
-}
-
-protocol::DispatcherBase* UberDispatcher::findDispatcher(const String& method) {
-    size_t dotIndex = StringUtil::find(method, ".");
-    if (dotIndex == StringUtil::kNotFound)
-        return nullptr;
-    String domain = StringUtil::substring(method, 0, dotIndex);
-    auto it = m_dispatchers.find(domain);
-    if (it == m_dispatchers.end())
-        return nullptr;
-    if (!it->second->canDispatch(method))
-        return nullptr;
-    return it->second.get();
-}
-
-bool UberDispatcher::canDispatch(const String& in_method)
-{
-    String method = in_method;
-    auto redirectIt = m_redirects.find(method);
-    if (redirectIt != m_redirects.end())
-        method = redirectIt->second;
-    return !!findDispatcher(method);
-}
-
-void UberDispatcher::dispatch(int callId, const String& in_method, std::unique_ptr<Value> parsedMessage, {{config.crdtp.namespace}}::span<uint8_t> rawMessage)
-{
-    String method = in_method;
-    auto redirectIt = m_redirects.find(method);
-    if (redirectIt != m_redirects.end())
-        method = redirectIt->second;
-    protocol::DispatcherBase* dispatcher = findDispatcher(method);
-    if (!dispatcher) {
-        reportProtocolErrorTo(m_frontendChannel, callId, DispatchResponse::kMethodNotFound, "'" + method + "' wasn't found", nullptr);
-        return;
-    }
-    std::unique_ptr<protocol::DictionaryValue> messageObject = DictionaryValue::cast(std::move(parsedMessage));
-    dispatcher->dispatch(callId, method, rawMessage, std::move(messageObject));
-}
-
-UberDispatcher::~UberDispatcher() = default;
-
-// static
-std::unique_ptr<Serializable> InternalResponse::createResponse(int callId, std::unique_ptr<Serializable> params)
-{
-    return std::unique_ptr<Serializable>(new InternalResponse(callId, nullptr, std::move(params)));
-}
-
-// static
-std::unique_ptr<Serializable> InternalResponse::createNotification(const char* method, std::unique_ptr<Serializable> params)
-{
-    return std::unique_ptr<Serializable>(new InternalResponse(0, method, std::move(params)));
-}
-
-// static
-std::unique_ptr<Serializable> InternalResponse::createErrorResponse(int callId, DispatchResponse::ErrorCode code, const String& message)
-{
-    return ProtocolError::createErrorResponse(callId, code, message, nullptr);
-}
-
-void InternalResponse::AppendSerialized(std::vector<uint8_t>* out) const
-{
-    using {{config.crdtp.namespace}}::cbor::NewCBOREncoder;
-    using {{config.crdtp.namespace}}::ParserHandler;
-    using {{config.crdtp.namespace}}::Status;
-    using {{config.crdtp.namespace}}::SpanFrom;
-
-    Status status;
-    std::unique_ptr<ParserHandler> encoder = NewCBOREncoder(out, &status);
-    encoder->HandleMapBegin();
-    if (m_method) {
-        encoder->HandleString8(SpanFrom("method"));
-        encoder->HandleString8(SpanFrom(m_method));
-        encoder->HandleString8(SpanFrom("params"));
-    } else {
-        encoder->HandleString8(SpanFrom("id"));
-        encoder->HandleInt32(m_callId);
-        encoder->HandleString8(SpanFrom("result"));
-    }
-    if (m_params) {
-        m_params->AppendSerialized(out);
-    } else {
-        encoder->HandleMapBegin();
-        encoder->HandleMapEnd();
-    }
-    encoder->HandleMapEnd();
-    DCHECK(status.ok());
-}
-
-InternalResponse::InternalResponse(int callId, const char* method, std::unique_ptr<Serializable> params)
-    : m_callId(callId)
-    , m_method(method)
-    , m_params(params ? std::move(params) : nullptr)
-{
-}
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
diff --git a/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_h.template b/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_h.template
deleted file mode 100644
index 5231123afc..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/DispatcherBase_h.template
+++ /dev/null
@@ -1,178 +0,0 @@
-// This file is generated by DispatcherBase_h.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef {{"_".join(config.protocol.namespace)}}_DispatcherBase_h
-#define {{"_".join(config.protocol.namespace)}}_DispatcherBase_h
-
-//#include "Forward.h"
-//#include "ErrorSupport.h"
-//#include "Values.h"
-
-#include "{{config.crdtp.dir}}/span.h"
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-class WeakPtr;
-
-class {{config.lib.export_macro}} DispatchResponse {
-public:
-    enum Status {
-        kSuccess = 0,
-        kError = 1,
-        kFallThrough = 2,
-    };
-
-    // For historical reasons, these error codes correspond to commonly used
-    // XMLRPC codes (e.g. see METHOD_NOT_FOUND in
-    // https://github.com/python/cpython/blob/master/Lib/xmlrpc/client.py).
-    enum ErrorCode {
-        kParseError = -32700,
-        kInvalidRequest = -32600,
-        kMethodNotFound = -32601,
-        kInvalidParams = -32602,
-        kInternalError = -32603,
-        kServerError = -32000,
-    };
-
-    Status status() const { return m_status; }
-    const String& errorMessage() const { return m_errorMessage; }
-    ErrorCode errorCode() const { return m_errorCode; }
-    bool isSuccess() const { return m_status == kSuccess; }
-
-    static DispatchResponse OK();
-    static DispatchResponse Error(const String&);
-    static DispatchResponse InternalError();
-    static DispatchResponse InvalidParams(const String&);
-    static DispatchResponse FallThrough();
-
-private:
-    Status m_status;
-    String m_errorMessage;
-    ErrorCode m_errorCode;
-};
-
-class {{config.lib.export_macro}} DispatcherBase {
-    PROTOCOL_DISALLOW_COPY(DispatcherBase);
-public:
-    static const char kInvalidParamsString[];
-    class {{config.lib.export_macro}} WeakPtr {
-    public:
-        explicit WeakPtr(DispatcherBase*);
-        ~WeakPtr();
-        DispatcherBase* get() { return m_dispatcher; }
-        void dispose() { m_dispatcher = nullptr; }
-
-    private:
-        DispatcherBase* m_dispatcher;
-    };
-
-    class {{config.lib.export_macro}} Callback {
-    public:
-        Callback(std::unique_ptr<WeakPtr> backendImpl, int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message);
-        virtual ~Callback();
-        void dispose();
-
-    protected:
-        void sendIfActive(std::unique_ptr<protocol::DictionaryValue> partialMessage, const DispatchResponse& response);
-        void fallThroughIfActive();
-
-    private:
-        std::unique_ptr<WeakPtr> m_backendImpl;
-        int m_callId;
-        String m_method;
-        std::vector<uint8_t> m_message;
-    };
-
-    explicit DispatcherBase(FrontendChannel*);
-    virtual ~DispatcherBase();
-
-    virtual bool canDispatch(const String& method) = 0;
-    virtual void dispatch(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> rawMessage, std::unique_ptr<protocol::DictionaryValue> messageObject) = 0;
-    FrontendChannel* channel() { return m_frontendChannel; }
-
-    void sendResponse(int callId, const DispatchResponse&, std::unique_ptr<protocol::DictionaryValue> result);
-    void sendResponse(int callId, const DispatchResponse&);
-
-    void reportProtocolError(int callId, DispatchResponse::ErrorCode, const String& errorMessage, ErrorSupport* errors);
-    void clearFrontend();
-
-    std::unique_ptr<WeakPtr> weakPtr();
-
-private:
-    FrontendChannel* m_frontendChannel;
-    std::unordered_set<WeakPtr*> m_weakPtrs;
-};
-
-class {{config.lib.export_macro}} UberDispatcher {
-    PROTOCOL_DISALLOW_COPY(UberDispatcher);
-public:
-    explicit UberDispatcher(FrontendChannel*);
-    void registerBackend(const String& name, std::unique_ptr<protocol::DispatcherBase>);
-    void setupRedirects(const std::unordered_map<String, String>&);
-    bool parseCommand(Value* message, int* callId, String* method);
-    bool canDispatch(const String& method);
-    void dispatch(int callId, const String& method, std::unique_ptr<Value> message, {{config.crdtp.namespace}}::span<uint8_t> rawMessage);
-    FrontendChannel* channel() { return m_frontendChannel; }
-    virtual ~UberDispatcher();
-
-private:
-    protocol::DispatcherBase* findDispatcher(const String& method);
-    FrontendChannel* m_frontendChannel;
-    std::unordered_map<String, String> m_redirects;
-    std::unordered_map<String, std::unique_ptr<protocol::DispatcherBase>> m_dispatchers;
-};
-
-class InternalResponse : public Serializable {
-    PROTOCOL_DISALLOW_COPY(InternalResponse);
-public:
-    static std::unique_ptr<Serializable> createResponse(int callId, std::unique_ptr<Serializable> params);
-    static std::unique_ptr<Serializable> createNotification(const char* method, std::unique_ptr<Serializable> params = nullptr);
-    static std::unique_ptr<Serializable> createErrorResponse(int callId, DispatchResponse::ErrorCode code, const String& message);
-
-    void AppendSerialized(std::vector<uint8_t>* out) const override;
-
-    ~InternalResponse() override {}
-
-private:
-    InternalResponse(int callId, const char* method, std::unique_ptr<Serializable> params);
-
-    int m_callId;
-    const char* m_method = nullptr;
-    std::unique_ptr<Serializable> m_params;
-};
-
-class InternalRawNotification : public Serializable {
-public:
-    static std::unique_ptr<InternalRawNotification> fromBinary(std::vector<uint8_t> notification)
-    {
-        return std::unique_ptr<InternalRawNotification>(new InternalRawNotification(std::move(notification)));
-    }
-
-    ~InternalRawNotification() override {}
-
-    std::vector<uint8_t> TakeSerialized() && override {
-        return std::move(m_binaryNotification);
-    }
-
-    void AppendSerialized(std::vector<uint8_t>* out) const override
-    {
-        out->insert(out->end(), m_binaryNotification.begin(), m_binaryNotification.end());
-    }
-
-private:
-  explicit InternalRawNotification(std::vector<uint8_t> notification)
-    : m_binaryNotification(std::move(notification)) { }
-
-  std::vector<uint8_t> m_binaryNotification;
-};
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
-
-#endif // !defined({{"_".join(config.protocol.namespace)}}_DispatcherBase_h)
diff --git a/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_cpp.template b/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_cpp.template
deleted file mode 100644
index a5c2a79bbd..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_cpp.template
+++ /dev/null
@@ -1,73 +0,0 @@
-// This file is generated by ErrorSupport_cpp.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-//#include "ErrorSupport.h"
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-ErrorSupport::ErrorSupport() { }
-ErrorSupport::~ErrorSupport() { }
-
-void ErrorSupport::setName(const char* name)
-{
-    setName(String(name));
-}
-
-void ErrorSupport::setName(const String& name)
-{
-    DCHECK(m_path.size());
-    m_path[m_path.size() - 1] = name;
-}
-
-void ErrorSupport::push()
-{
-    m_path.push_back(String());
-}
-
-void ErrorSupport::pop()
-{
-    m_path.pop_back();
-}
-
-void ErrorSupport::addError(const char* error)
-{
-    addError(String(error));
-}
-
-void ErrorSupport::addError(const String& error)
-{
-    StringBuilder builder;
-    for (size_t i = 0; i < m_path.size(); ++i) {
-        if (i)
-            StringUtil::builderAppend(builder, '.');
-        StringUtil::builderAppend(builder, m_path[i]);
-    }
-    StringUtil::builderAppend(builder, ": ");
-    StringUtil::builderAppend(builder, error);
-    m_errors.push_back(StringUtil::builderToString(builder));
-}
-
-bool ErrorSupport::hasErrors()
-{
-    return !!m_errors.size();
-}
-
-String ErrorSupport::errors()
-{
-    StringBuilder builder;
-    for (size_t i = 0; i < m_errors.size(); ++i) {
-        if (i)
-            StringUtil::builderAppend(builder, "; ");
-        StringUtil::builderAppend(builder, m_errors[i]);
-    }
-    return StringUtil::builderToString(builder);
-}
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
diff --git a/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_h.template b/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_h.template
deleted file mode 100644
index f317a3cfb4..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/ErrorSupport_h.template
+++ /dev/null
@@ -1,39 +0,0 @@
-// This file is generated by ErrorSupport_h.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef {{"_".join(config.protocol.namespace)}}_ErrorSupport_h
-#define {{"_".join(config.protocol.namespace)}}_ErrorSupport_h
-
-#include {{format_include(config.protocol.package, "Forward")}}
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-class {{config.lib.export_macro}} ErrorSupport {
-public:
-    ErrorSupport();
-    ~ErrorSupport();
-
-    void push();
-    void setName(const char*);
-    void setName(const String&);
-    void pop();
-    void addError(const char*);
-    void addError(const String&);
-    bool hasErrors();
-    String errors();
-
-private:
-    std::vector<String> m_path;
-    std::vector<String> m_errors;
-};
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
-
-#endif // !defined({{"_".join(config.protocol.namespace)}}_ErrorSupport_h)
diff --git a/deps/v8/third_party/inspector_protocol/lib/Forward_h.template b/deps/v8/third_party/inspector_protocol/lib/Forward_h.template
index aefc1a16e8..e2eef3042f 100644
--- a/deps/v8/third_party/inspector_protocol/lib/Forward_h.template
+++ b/deps/v8/third_party/inspector_protocol/lib/Forward_h.template
@@ -18,6 +18,9 @@
 #include <unordered_map>
 #include <unordered_set>
 
+#include "{{config.crdtp.dir}}/error_support.h"
+#include "{{config.crdtp.dir}}/dispatch.h"
+#include "{{config.crdtp.dir}}/frontend_channel.h"
 #include "{{config.crdtp.dir}}/glue.h"
 
 {% for namespace in config.protocol.namespace %}
@@ -25,15 +28,18 @@ namespace {{namespace}} {
 {% endfor %}
 
 class DictionaryValue;
-class DispatchResponse;
-class ErrorSupport;
+using DispatchResponse = {{config.crdtp.namespace}}::DispatchResponse;
+using ErrorSupport = {{config.crdtp.namespace}}::ErrorSupport;
+using Serializable = {{config.crdtp.namespace}}::Serializable;
+using FrontendChannel = {{config.crdtp.namespace}}::FrontendChannel;
+using DomainDispatcher = {{config.crdtp.namespace}}::DomainDispatcher;
+using UberDispatcher = {{config.crdtp.namespace}}::UberDispatcher;
 class FundamentalValue;
 class ListValue;
 class Object;
 using Response = DispatchResponse;
 class SerializedValue;
 class StringValue;
-class UberDispatcher;
 class Value;
 
 namespace detail {
diff --git a/deps/v8/third_party/inspector_protocol/lib/FrontendChannel_h.template b/deps/v8/third_party/inspector_protocol/lib/FrontendChannel_h.template
deleted file mode 100644
index b677ecdd48..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/FrontendChannel_h.template
+++ /dev/null
@@ -1,33 +0,0 @@
-// This file is generated by FrontendChannel_h.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef {{"_".join(config.protocol.namespace)}}_FrontendChannel_h
-#define {{"_".join(config.protocol.namespace)}}_FrontendChannel_h
-
-#include "{{config.crdtp.dir}}/serializable.h"
-#include "{{config.crdtp.dir}}/span.h"
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-using {{config.crdtp.namespace}}::Serializable;
-
-class {{config.lib.export_macro}} FrontendChannel {
-public:
-    virtual ~FrontendChannel() { }
-    virtual void sendProtocolResponse(int callId, std::unique_ptr<Serializable> message) = 0;
-    virtual void sendProtocolNotification(std::unique_ptr<Serializable> message) = 0;
-
-    virtual void fallThrough(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message) = 0;
-    virtual void flushProtocolNotifications() = 0;
-};
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
-
-#endif // !defined({{"_".join(config.protocol.namespace)}}_FrontendChannel_h)
diff --git a/deps/v8/third_party/inspector_protocol/lib/Object_cpp.template b/deps/v8/third_party/inspector_protocol/lib/Object_cpp.template
index 3fc36b9ee3..b639b1bb77 100644
--- a/deps/v8/third_party/inspector_protocol/lib/Object_cpp.template
+++ b/deps/v8/third_party/inspector_protocol/lib/Object_cpp.template
@@ -14,7 +14,7 @@ std::unique_ptr<Object> Object::fromValue(protocol::Value* value, ErrorSupport*
 {
     protocol::DictionaryValue* dictionary = DictionaryValue::cast(value);
     if (!dictionary) {
-        errors->addError("object expected");
+        errors->AddError("object expected");
         return nullptr;
     }
     dictionary = static_cast<protocol::DictionaryValue*>(dictionary->clone().release());
diff --git a/deps/v8/third_party/inspector_protocol/lib/Parser_cpp.template b/deps/v8/third_party/inspector_protocol/lib/Parser_cpp.template
deleted file mode 100644
index ea7ecc5a1a..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/Parser_cpp.template
+++ /dev/null
@@ -1,548 +0,0 @@
-// This file is generated by Parser_cpp.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-namespace {
-
-const int stackLimit = 1000;
-
-enum Token {
-    ObjectBegin,
-    ObjectEnd,
-    ArrayBegin,
-    ArrayEnd,
-    StringLiteral,
-    Number,
-    BoolTrue,
-    BoolFalse,
-    NullToken,
-    ListSeparator,
-    ObjectPairSeparator,
-    InvalidToken,
-};
-
-const char* const nullString = "null";
-const char* const trueString = "true";
-const char* const falseString = "false";
-
-bool isASCII(uint16_t c)
-{
-    return !(c & ~0x7F);
-}
-
-bool isSpaceOrNewLine(uint16_t c)
-{
-    return isASCII(c) && c <= ' ' && (c == ' ' || (c <= 0xD && c >= 0x9));
-}
-
-double charactersToDouble(const uint16_t* characters, size_t length, bool* ok)
-{
-    std::vector<char> buffer;
-    buffer.reserve(length + 1);
-    for (size_t i = 0; i < length; ++i) {
-        if (!isASCII(characters[i])) {
-            *ok = false;
-            return 0;
-        }
-        buffer.push_back(static_cast<char>(characters[i]));
-    }
-    buffer.push_back('\0');
-    return StringUtil::toDouble(buffer.data(), length, ok);
-}
-
-double charactersToDouble(const uint8_t* characters, size_t length, bool* ok)
-{
-    std::string buffer(reinterpret_cast<const char*>(characters), length);
-    return StringUtil::toDouble(buffer.data(), length, ok);
-}
-
-template<typename Char>
-bool parseConstToken(const Char* start, const Char* end, const Char** tokenEnd, const char* token)
-{
-    while (start < end && *token != '\0' && *start++ == *token++) { }
-    if (*token != '\0')
-        return false;
-    *tokenEnd = start;
-    return true;
-}
-
-template<typename Char>
-bool readInt(const Char* start, const Char* end, const Char** tokenEnd, bool canHaveLeadingZeros)
-{
-    if (start == end)
-        return false;
-    bool haveLeadingZero = '0' == *start;
-    int length = 0;
-    while (start < end && '0' <= *start && *start <= '9') {
-        ++start;
-        ++length;
-    }
-    if (!length)
-        return false;
-    if (!canHaveLeadingZeros && length > 1 && haveLeadingZero)
-        return false;
-    *tokenEnd = start;
-    return true;
-}
-
-template<typename Char>
-bool parseNumberToken(const Char* start, const Char* end, const Char** tokenEnd)
-{
-    // We just grab the number here. We validate the size in DecodeNumber.
-    // According to RFC4627, a valid number is: [minus] int [frac] [exp]
-    if (start == end)
-        return false;
-    Char c = *start;
-    if ('-' == c)
-        ++start;
-
-    if (!readInt(start, end, &start, false))
-        return false;
-    if (start == end) {
-        *tokenEnd = start;
-        return true;
-    }
-
-    // Optional fraction part
-    c = *start;
-    if ('.' == c) {
-        ++start;
-        if (!readInt(start, end, &start, true))
-            return false;
-        if (start == end) {
-            *tokenEnd = start;
-            return true;
-        }
-        c = *start;
-    }
-
-    // Optional exponent part
-    if ('e' == c || 'E' == c) {
-        ++start;
-        if (start == end)
-            return false;
-        c = *start;
-        if ('-' == c || '+' == c) {
-            ++start;
-            if (start == end)
-                return false;
-        }
-        if (!readInt(start, end, &start, true))
-            return false;
-    }
-
-    *tokenEnd = start;
-    return true;
-}
-
-template<typename Char>
-bool readHexDigits(const Char* start, const Char* end, const Char** tokenEnd, int digits)
-{
-    if (end - start < digits)
-        return false;
-    for (int i = 0; i < digits; ++i) {
-        Char c = *start++;
-        if (!(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')))
-            return false;
-    }
-    *tokenEnd = start;
-    return true;
-}
-
-template<typename Char>
-bool parseStringToken(const Char* start, const Char* end, const Char** tokenEnd)
-{
-    while (start < end) {
-        Char c = *start++;
-        if ('\\' == c) {
-	    if (start == end)
-	        return false;
-            c = *start++;
-            // Make sure the escaped char is valid.
-            switch (c) {
-            case 'x':
-                if (!readHexDigits(start, end, &start, 2))
-                    return false;
-                break;
-            case 'u':
-                if (!readHexDigits(start, end, &start, 4))
-                    return false;
-                break;
-            case '\\':
-            case '/':
-            case 'b':
-            case 'f':
-            case 'n':
-            case 'r':
-            case 't':
-            case 'v':
-            case '"':
-                break;
-            default:
-                return false;
-            }
-        } else if ('"' == c) {
-            *tokenEnd = start;
-            return true;
-        }
-    }
-    return false;
-}
-
-template<typename Char>
-bool skipComment(const Char* start, const Char* end, const Char** commentEnd)
-{
-    if (start == end)
-        return false;
-
-    if (*start != '/' || start + 1 >= end)
-        return false;
-    ++start;
-
-    if (*start == '/') {
-        // Single line comment, read to newline.
-        for (++start; start < end; ++start) {
-            if (*start == '\n' || *start == '\r') {
-                *commentEnd = start + 1;
-                return true;
-            }
-        }
-        *commentEnd = end;
-        // Comment reaches end-of-input, which is fine.
-        return true;
-    }
-
-    if (*start == '*') {
-        Char previous = '\0';
-        // Block comment, read until end marker.
-        for (++start; start < end; previous = *start++) {
-            if (previous == '*' && *start == '/') {
-                *commentEnd = start + 1;
-                return true;
-            }
-        }
-        // Block comment must close before end-of-input.
-        return false;
-    }
-
-    return false;
-}
-
-template<typename Char>
-void skipWhitespaceAndComments(const Char* start, const Char* end, const Char** whitespaceEnd)
-{
-    while (start < end) {
-        if (isSpaceOrNewLine(*start)) {
-            ++start;
-        } else if (*start == '/') {
-            const Char* commentEnd;
-            if (!skipComment(start, end, &commentEnd))
-                break;
-            start = commentEnd;
-        } else {
-            break;
-        }
-    }
-    *whitespaceEnd = start;
-}
-
-template<typename Char>
-Token parseToken(const Char* start, const Char* end, const Char** tokenStart, const Char** tokenEnd)
-{
-    skipWhitespaceAndComments(start, end, tokenStart);
-    start = *tokenStart;
-
-    if (start == end)
-        return InvalidToken;
-
-    switch (*start) {
-    case 'n':
-        if (parseConstToken(start, end, tokenEnd, nullString))
-            return NullToken;
-        break;
-    case 't':
-        if (parseConstToken(start, end, tokenEnd, trueString))
-            return BoolTrue;
-        break;
-    case 'f':
-        if (parseConstToken(start, end, tokenEnd, falseString))
-            return BoolFalse;
-        break;
-    case '[':
-        *tokenEnd = start + 1;
-        return ArrayBegin;
-    case ']':
-        *tokenEnd = start + 1;
-        return ArrayEnd;
-    case ',':
-        *tokenEnd = start + 1;
-        return ListSeparator;
-    case '{':
-        *tokenEnd = start + 1;
-        return ObjectBegin;
-    case '}':
-        *tokenEnd = start + 1;
-        return ObjectEnd;
-    case ':':
-        *tokenEnd = start + 1;
-        return ObjectPairSeparator;
-    case '0':
-    case '1':
-    case '2':
-    case '3':
-    case '4':
-    case '5':
-    case '6':
-    case '7':
-    case '8':
-    case '9':
-    case '-':
-        if (parseNumberToken(start, end, tokenEnd))
-            return Number;
-        break;
-    case '"':
-        if (parseStringToken(start + 1, end, tokenEnd))
-            return StringLiteral;
-        break;
-    }
-    return InvalidToken;
-}
-
-template<typename Char>
-int hexToInt(Char c)
-{
-    if ('0' <= c && c <= '9')
-        return c - '0';
-    if ('A' <= c && c <= 'F')
-        return c - 'A' + 10;
-    if ('a' <= c && c <= 'f')
-        return c - 'a' + 10;
-    DCHECK(false);
-    return 0;
-}
-
-template<typename Char>
-bool decodeString(const Char* start, const Char* end, StringBuilder* output)
-{
-    while (start < end) {
-        uint16_t c = *start++;
-        if ('\\' != c) {
-            StringUtil::builderAppend(*output, c);
-            continue;
-        }
-	if (start == end)
-	    return false;
-        c = *start++;
-
-        if (c == 'x') {
-            // \x is not supported.
-            return false;
-        }
-
-        switch (c) {
-        case '"':
-        case '/':
-        case '\\':
-            break;
-        case 'b':
-            c = '\b';
-            break;
-        case 'f':
-            c = '\f';
-            break;
-        case 'n':
-            c = '\n';
-            break;
-        case 'r':
-            c = '\r';
-            break;
-        case 't':
-            c = '\t';
-            break;
-        case 'v':
-            c = '\v';
-            break;
-        case 'u':
-            c = (hexToInt(*start) << 12) +
-                (hexToInt(*(start + 1)) << 8) +
-                (hexToInt(*(start + 2)) << 4) +
-                hexToInt(*(start + 3));
-            start += 4;
-            break;
-        default:
-            return false;
-        }
-        StringUtil::builderAppend(*output, c);
-    }
-    return true;
-}
-
-template<typename Char>
-bool decodeString(const Char* start, const Char* end, String* output)
-{
-    if (start == end) {
-        *output = "";
-        return true;
-    }
-    if (start > end)
-        return false;
-    StringBuilder buffer;
-    StringUtil::builderReserve(buffer, end - start);
-    if (!decodeString(start, end, &buffer))
-        return false;
-    *output = StringUtil::builderToString(buffer);
-    return true;
-}
-
-template<typename Char>
-std::unique_ptr<Value> buildValue(const Char* start, const Char* end, const Char** valueTokenEnd, int depth)
-{
-    if (depth > stackLimit)
-        return nullptr;
-
-    std::unique_ptr<Value> result;
-    const Char* tokenStart;
-    const Char* tokenEnd;
-    Token token = parseToken(start, end, &tokenStart, &tokenEnd);
-    switch (token) {
-    case InvalidToken:
-        return nullptr;
-    case NullToken:
-        result = Value::null();
-        break;
-    case BoolTrue:
-        result = FundamentalValue::create(true);
-        break;
-    case BoolFalse:
-        result = FundamentalValue::create(false);
-        break;
-    case Number: {
-        bool ok;
-        double value = charactersToDouble(tokenStart, tokenEnd - tokenStart, &ok);
-        if (!ok)
-            return nullptr;
-        if (value >= INT_MIN && value <= INT_MAX && static_cast<int>(value) == value)
-            result = FundamentalValue::create(static_cast<int>(value));
-        else
-            result = FundamentalValue::create(value);
-        break;
-    }
-    case StringLiteral: {
-        String value;
-        bool ok = decodeString(tokenStart + 1, tokenEnd - 1, &value);
-        if (!ok)
-            return nullptr;
-        result = StringValue::create(value);
-        break;
-    }
-    case ArrayBegin: {
-        std::unique_ptr<ListValue> array = ListValue::create();
-        start = tokenEnd;
-        token = parseToken(start, end, &tokenStart, &tokenEnd);
-        while (token != ArrayEnd) {
-            std::unique_ptr<Value> arrayNode = buildValue(start, end, &tokenEnd, depth + 1);
-            if (!arrayNode)
-                return nullptr;
-            array->pushValue(std::move(arrayNode));
-
-            // After a list value, we expect a comma or the end of the list.
-            start = tokenEnd;
-            token = parseToken(start, end, &tokenStart, &tokenEnd);
-            if (token == ListSeparator) {
-                start = tokenEnd;
-                token = parseToken(start, end, &tokenStart, &tokenEnd);
-                if (token == ArrayEnd)
-                    return nullptr;
-            } else if (token != ArrayEnd) {
-                // Unexpected value after list value. Bail out.
-                return nullptr;
-            }
-        }
-        if (token != ArrayEnd)
-            return nullptr;
-        result = std::move(array);
-        break;
-    }
-    case ObjectBegin: {
-        std::unique_ptr<DictionaryValue> object = DictionaryValue::create();
-        start = tokenEnd;
-        token = parseToken(start, end, &tokenStart, &tokenEnd);
-        while (token != ObjectEnd) {
-            if (token != StringLiteral)
-                return nullptr;
-            String key;
-            if (!decodeString(tokenStart + 1, tokenEnd - 1, &key))
-                return nullptr;
-            start = tokenEnd;
-
-            token = parseToken(start, end, &tokenStart, &tokenEnd);
-            if (token != ObjectPairSeparator)
-                return nullptr;
-            start = tokenEnd;
-
-            std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, depth + 1);
-            if (!value)
-                return nullptr;
-            object->setValue(key, std::move(value));
-            start = tokenEnd;
-
-            // After a key/value pair, we expect a comma or the end of the
-            // object.
-            token = parseToken(start, end, &tokenStart, &tokenEnd);
-            if (token == ListSeparator) {
-                start = tokenEnd;
-                token = parseToken(start, end, &tokenStart, &tokenEnd);
-                if (token == ObjectEnd)
-                    return nullptr;
-            } else if (token != ObjectEnd) {
-                // Unexpected value after last object value. Bail out.
-                return nullptr;
-            }
-        }
-        if (token != ObjectEnd)
-            return nullptr;
-        result = std::move(object);
-        break;
-    }
-
-    default:
-        // We got a token that's not a value.
-        return nullptr;
-    }
-
-    skipWhitespaceAndComments(tokenEnd, end, valueTokenEnd);
-    return result;
-}
-
-template<typename Char>
-std::unique_ptr<Value> parseJSONInternal(const Char* start, unsigned length)
-{
-    const Char* end = start + length;
-    const Char *tokenEnd;
-    std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, 0);
-    if (!value || tokenEnd != end)
-        return nullptr;
-    return value;
-}
-
-} // anonymous namespace
-
-std::unique_ptr<Value> parseJSONCharacters(const uint16_t* characters, unsigned length)
-{
-    return parseJSONInternal<uint16_t>(characters, length);
-}
-
-std::unique_ptr<Value> parseJSONCharacters(const uint8_t* characters, unsigned length)
-{
-    return parseJSONInternal<uint8_t>(characters, length);
-}
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
diff --git a/deps/v8/third_party/inspector_protocol/lib/Parser_h.template b/deps/v8/third_party/inspector_protocol/lib/Parser_h.template
deleted file mode 100644
index 1832c2e972..0000000000
--- a/deps/v8/third_party/inspector_protocol/lib/Parser_h.template
+++ /dev/null
@@ -1,24 +0,0 @@
-// This file is generated by Parser_h.template.
-
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef {{"_".join(config.protocol.namespace)}}_Parser_h
-#define {{"_".join(config.protocol.namespace)}}_Parser_h
-
-//#include "Forward.h"
-//#include "Values.h"
-
-{% for namespace in config.protocol.namespace %}
-namespace {{namespace}} {
-{% endfor %}
-
-{{config.lib.export_macro}} std::unique_ptr<Value> parseJSONCharacters(const uint8_t*, unsigned);
-{{config.lib.export_macro}} std::unique_ptr<Value> parseJSONCharacters(const uint16_t*, unsigned);
-
-{% for namespace in config.protocol.namespace %}
-} // namespace {{namespace}}
-{% endfor %}
-
-#endif // !defined({{"_".join(config.protocol.namespace)}}_Parser_h)
diff --git a/deps/v8/third_party/inspector_protocol/lib/ValueConversions_h.template b/deps/v8/third_party/inspector_protocol/lib/ValueConversions_h.template
index 63baf689c6..15961a6321 100644
--- a/deps/v8/third_party/inspector_protocol/lib/ValueConversions_h.template
+++ b/deps/v8/third_party/inspector_protocol/lib/ValueConversions_h.template
@@ -40,7 +40,7 @@ struct ValueConversions<bool> {
         bool result = false;
         bool success = value ? value->asBoolean(&result) : false;
         if (!success)
-            errors->addError("boolean value expected");
+            errors->AddError("boolean value expected");
         return result;
     }
 
@@ -57,7 +57,7 @@ struct ValueConversions<int> {
         int result = 0;
         bool success = value ? value->asInteger(&result) : false;
         if (!success)
-            errors->addError("integer value expected");
+            errors->AddError("integer value expected");
         return result;
     }
 
@@ -74,7 +74,7 @@ struct ValueConversions<double> {
         double result = 0;
         bool success = value ? value->asDouble(&result) : false;
         if (!success)
-            errors->addError("double value expected");
+            errors->AddError("double value expected");
         return result;
     }
 
@@ -91,7 +91,7 @@ struct ValueConversions<String> {
         String result;
         bool success = value ? value->asString(&result) : false;
         if (!success)
-            errors->addError("string value expected");
+            errors->AddError("string value expected");
         return result;
     }
 
@@ -107,7 +107,7 @@ struct ValueConversions<Binary> {
     {
         if (!value ||
             (value->type() != Value::TypeBinary && value->type() != Value::TypeString)) {
-            errors->addError("Either string base64 or binary value expected");
+            errors->AddError("Either string base64 or binary value expected");
             return Binary();
         }
         Binary binary;
@@ -118,7 +118,7 @@ struct ValueConversions<Binary> {
         bool success;
         Binary out = Binary::fromBase64(result, &success);
         if (!success)
-          errors->addError("base64 decoding error");
+          errors->AddError("base64 decoding error");
         return out;
     }
 
@@ -133,20 +133,20 @@ struct ValueConversions<std::vector<std::unique_ptr<T>>> {
     static std::unique_ptr<std::vector<std::unique_ptr<T>>> fromValue(protocol::Value* value, ErrorSupport* errors) {
         protocol::ListValue* array = ListValue::cast(value);
         if (!array) {
-            errors->addError("array expected");
+            errors->AddError("array expected");
             return nullptr;
         }
-        errors->push();
+        errors->Push();
         std::unique_ptr<std::vector<std::unique_ptr<T>>> result(
             new std::vector<std::unique_ptr<T>>());
         result->reserve(array->size());
         for (size_t i = 0; i < array->size(); ++i) {
-            errors->setName(StringUtil::fromInteger(i));
+            errors->SetIndex(i);
             auto item = ValueConversions<T>::fromValue(array->at(i), errors);
             result->emplace_back(std::move(item));
         }
-        errors->pop();
-        if (errors->hasErrors())
+        errors->Pop();
+        if (!errors->Errors().empty())
             return nullptr;
         return result;
     }
@@ -167,19 +167,19 @@ struct ValueConversions<std::vector<T>> {
     static std::unique_ptr<std::vector<T>> fromValue(protocol::Value* value, ErrorSupport* errors) {
         protocol::ListValue* array = ListValue::cast(value);
         if (!array) {
-            errors->addError("array expected");
+            errors->AddError("array expected");
             return nullptr;
         }
-        errors->push();
+        errors->Push();
         std::unique_ptr<std::vector<T>> result(new std::vector<T>());
         result->reserve(array->size());
         for (size_t i = 0; i < array->size(); ++i) {
-            errors->setName(StringUtil::fromInteger(i));
+            errors->SetIndex(i);
             auto item = ValueConversions<T>::fromValue(array->at(i), errors);
             result->emplace_back(std::move(item));
         }
-        errors->pop();
-        if (errors->hasErrors())
+        errors->Pop();
+        if (!errors->Errors().empty())
             return nullptr;
         return result;
     }
@@ -200,7 +200,7 @@ struct ValueConversions<Value> {
     {
         bool success = !!value;
         if (!success) {
-            errors->addError("value expected");
+            errors->AddError("value expected");
             return nullptr;
         }
         return value->clone();
@@ -223,7 +223,7 @@ struct ValueConversions<DictionaryValue> {
     {
         bool success = value && value->type() == protocol::Value::TypeObject;
         if (!success)
-            errors->addError("object expected");
+            errors->AddError("object expected");
         return DictionaryValue::cast(value->clone());
     }
 
@@ -244,7 +244,7 @@ struct ValueConversions<ListValue> {
     {
         bool success = value && value->type() == protocol::Value::TypeArray;
         if (!success)
-            errors->addError("list expected");
+            errors->AddError("list expected");
         return ListValue::cast(value->clone());
     }
 
diff --git a/deps/v8/third_party/inspector_protocol/lib/Values_cpp.template b/deps/v8/third_party/inspector_protocol/lib/Values_cpp.template
index 91cd471983..09f3bed136 100644
--- a/deps/v8/third_party/inspector_protocol/lib/Values_cpp.template
+++ b/deps/v8/third_party/inspector_protocol/lib/Values_cpp.template
@@ -13,16 +13,11 @@ namespace {{namespace}} {
 {% endfor %}
 
 namespace {
-// When parsing CBOR, we limit recursion depth for objects and arrays
-// to this constant.
-static constexpr int kStackLimitValues = 1000;
-
-using {{config.crdtp.namespace}}::Error;
 using {{config.crdtp.namespace}}::Status;
+using {{config.crdtp.namespace}}::ParserHandler;
 using {{config.crdtp.namespace}}::span;
 namespace cbor {
-using {{config.crdtp.namespace}}::cbor::CBORTokenTag;
-using {{config.crdtp.namespace}}::cbor::CBORTokenizer;
+using {{config.crdtp.namespace}}::cbor::ParseCBOR;
 using {{config.crdtp.namespace}}::cbor::EncodeBinary;
 using {{config.crdtp.namespace}}::cbor::EncodeDouble;
 using {{config.crdtp.namespace}}::cbor::EncodeFalse;
@@ -39,165 +34,161 @@ using {{config.crdtp.namespace}}::cbor::EnvelopeEncoder;
 using {{config.crdtp.namespace}}::cbor::InitialByteForEnvelope;
 }  // namespace cbor
 
-// Below are three parsing routines for CBOR, which cover enough
-// to roundtrip JSON messages.
-std::unique_ptr<DictionaryValue> parseMap(int32_t stack_depth, cbor::CBORTokenizer* tokenizer);
-std::unique_ptr<ListValue> parseArray(int32_t stack_depth, cbor::CBORTokenizer* tokenizer);
-std::unique_ptr<Value> parseValue(int32_t stack_depth, cbor::CBORTokenizer* tokenizer);
-
-// |bytes| must start with the indefinite length array byte, so basically,
-// ParseArray may only be called after an indefinite length array has been
-// detected.
-std::unique_ptr<ListValue> parseArray(int32_t stack_depth, cbor::CBORTokenizer* tokenizer) {
-  DCHECK(tokenizer->TokenTag() == cbor::CBORTokenTag::ARRAY_START);
-  tokenizer->Next();
-  auto list = ListValue::create();
-  while (tokenizer->TokenTag() != cbor::CBORTokenTag::STOP) {
-    // Error::CBOR_UNEXPECTED_EOF_IN_ARRAY
-    if (tokenizer->TokenTag() == cbor::CBORTokenTag::DONE) return nullptr;
-    if (tokenizer->TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) return nullptr;
-    // Parse value.
-    auto value = parseValue(stack_depth, tokenizer);
-    if (!value) return nullptr;
-    list->pushValue(std::move(value));
+// Uses the parsing events received from driver of |ParserHandler|
+// (e.g. cbor::ParseCBOR) into a protocol::Value instance.
+class ValueParserHandler : public ParserHandler {
+ public:
+   // Provides the parsed protocol::Value.
+   std::unique_ptr<Value> ReleaseRoot() { return std::move(root_); }
+
+   // The first parsing error encountered; |status().ok()| is the default.
+   Status status() const { return status_; }
+
+ private:
+  //
+  // Implementation of  ParserHandler.
+  //
+  void HandleMapBegin() override {
+    if (!status_.ok()) return;
+    std::unique_ptr<DictionaryValue> dict = DictionaryValue::create();
+    DictionaryValue* dict_ptr = dict.get();
+    AddValueToParent(std::move(dict));
+    stack_.emplace_back(dict_ptr);
   }
-  tokenizer->Next();
-  return list;
-}
-
-std::unique_ptr<Value> parseValue(
-    int32_t stack_depth, cbor::CBORTokenizer* tokenizer) {
-  // Error::CBOR_STACK_LIMIT_EXCEEDED
-  if (stack_depth > kStackLimitValues) return nullptr;
-  // Skip past the envelope to get to what's inside.
-  if (tokenizer->TokenTag() == cbor::CBORTokenTag::ENVELOPE)
-    tokenizer->EnterEnvelope();
-  switch (tokenizer->TokenTag()) {
-    case cbor::CBORTokenTag::ERROR_VALUE:
-      return nullptr;
-    case cbor::CBORTokenTag::DONE:
-      // Error::CBOR_UNEXPECTED_EOF_EXPECTED_VALUE
-      return nullptr;
-    case cbor::CBORTokenTag::TRUE_VALUE: {
-      std::unique_ptr<Value> value = FundamentalValue::create(true);
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::FALSE_VALUE: {
-      std::unique_ptr<Value> value = FundamentalValue::create(false);
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::NULL_VALUE: {
-      std::unique_ptr<Value> value = FundamentalValue::null();
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::INT32: {
-      std::unique_ptr<Value> value = FundamentalValue::create(tokenizer->GetInt32());
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::DOUBLE: {
-      std::unique_ptr<Value> value = FundamentalValue::create(tokenizer->GetDouble());
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::STRING8: {
-      span<uint8_t> str = tokenizer->GetString8();
-      std::unique_ptr<Value> value =
-          StringValue::create(StringUtil::fromUTF8(str.data(), str.size()));
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::STRING16: {
-      span<uint8_t> wire = tokenizer->GetString16WireRep();
-      DCHECK_EQ(wire.size() & 1, 0u);
-      std::unique_ptr<Value> value = StringValue::create(StringUtil::fromUTF16LE(
-          reinterpret_cast<const uint16_t*>(wire.data()), wire.size() / 2));
-      tokenizer->Next();
-      return value;
-    }
-    case cbor::CBORTokenTag::BINARY: {
-      span<uint8_t> payload = tokenizer->GetBinary();
-      tokenizer->Next();
-      return BinaryValue::create(Binary::fromSpan(payload.data(), payload.size()));
-    }
-    case cbor::CBORTokenTag::MAP_START:
-      return parseMap(stack_depth + 1, tokenizer);
-    case cbor::CBORTokenTag::ARRAY_START:
-      return parseArray(stack_depth + 1, tokenizer);
-    default:
-      // Error::CBOR_UNSUPPORTED_VALUE
-      return nullptr;
+
+  void HandleMapEnd() override {
+    if (!status_.ok()) return;
+    DCHECK(!stack_.empty());
+    DCHECK(stack_.back().is_dict);
+    stack_.pop_back();
+  }
+  
+  void HandleArrayBegin() override {
+    if (!status_.ok()) return;
+    std::unique_ptr<ListValue> list = ListValue::create();
+    ListValue* list_ptr = list.get();
+    AddValueToParent(std::move(list));
+    stack_.emplace_back(list_ptr);
+  }
+
+  void HandleArrayEnd() override {
+    if (!status_.ok()) return;
+    DCHECK(!stack_.empty());
+    DCHECK(!stack_.back().is_dict);
+    stack_.pop_back();
+  }
+
+  void HandleString8(span<uint8_t> chars) override {
+    AddStringToParent(StringUtil::fromUTF8(chars.data(), chars.size()));
+  }
+
+  void HandleString16(span<uint16_t> chars) override {
+    AddStringToParent(
+        StringUtil::fromUTF16LE(chars.data(), chars.size()));
+  }
+
+  void HandleBinary(span<uint8_t> bytes) override {
+    AddValueToParent(
+        BinaryValue::create(Binary::fromSpan(bytes.data(), bytes.size())));
+  }
+   
+  void HandleDouble(double value) override {
+    AddValueToParent(FundamentalValue::create(value));
+  }
+   
+  void HandleInt32(int32_t value) override {
+    AddValueToParent(FundamentalValue::create(value));
+  }
+   
+  void HandleBool(bool value) override {
+    AddValueToParent(FundamentalValue::create(value));
+  }
+   
+  void HandleNull() override {
+    AddValueToParent(Value::null());
+  }
+
+  void HandleError(Status error) override {
+    status_ = error;
   }
-}
 
-// |bytes| must start with the indefinite length array byte, so basically,
-// ParseArray may only be called after an indefinite length array has been
-// detected.
-std::unique_ptr<DictionaryValue> parseMap(
-    int32_t stack_depth, cbor::CBORTokenizer* tokenizer) {
-  auto dict = DictionaryValue::create();
-  tokenizer->Next();
-  while (tokenizer->TokenTag() != cbor::CBORTokenTag::STOP) {
-    if (tokenizer->TokenTag() == cbor::CBORTokenTag::DONE) {
-      // Error::CBOR_UNEXPECTED_EOF_IN_MAP
-      return nullptr;
+  //
+  // Adding strings and values to the parent value.
+  // Strings are handled separately because they can be keys for
+  // dictionary values.
+  //
+  void AddStringToParent(String str) {
+    if (!status_.ok()) return;
+    if (!root_) {
+      DCHECK(!key_is_pending_);
+      root_ = StringValue::create(str);
+    } else if (stack_.back().is_dict) {
+      // If we already have a pending key, then this is the value of the
+      // key/value pair. Otherwise, it's the new pending key.
+      if (key_is_pending_) {
+        stack_.back().dict->setString(pending_key_, str);
+        key_is_pending_ = false;
+      } else {
+        pending_key_ = std::move(str);
+        key_is_pending_ = true;
+      }
+    } else {  // Top of the stack is a list.
+      DCHECK(!key_is_pending_);
+      stack_.back().list->pushValue(StringValue::create(str));
     }
-    if (tokenizer->TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) return nullptr;
-    // Parse key.
-    String key;
-    if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING8) {
-      span<uint8_t> key_span = tokenizer->GetString8();
-      key = StringUtil::fromUTF8(key_span.data(), key_span.size());
-      tokenizer->Next();
-    } else if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING16) {
-      span<uint8_t> key_span = tokenizer->GetString16WireRep();
-      if (key_span.size() & 1) return nullptr;  // UTF16 is 2 byte multiple.
-      key = StringUtil::fromUTF16LE(
-          reinterpret_cast<const uint16_t*>(key_span.data()),
-          key_span.size() / 2);
-      tokenizer->Next();
-    } else {
-      // Error::CBOR_INVALID_MAP_KEY
-      return nullptr;
+  }
+
+  void AddValueToParent(std::unique_ptr<Value> value) {
+    if (!status_.ok()) return;
+    if (!root_) {
+      DCHECK(!key_is_pending_);
+      root_ = std::move(value);
+    } else if (stack_.back().is_dict) {
+      DCHECK(key_is_pending_);
+      stack_.back().dict->setValue(pending_key_, std::move(value));
+      key_is_pending_ = false;
+    } else {  // Top of the stack is a list.
+      DCHECK(!key_is_pending_);
+      stack_.back().list->pushValue(std::move(value));
     }
-    // Parse value.
-    auto value = parseValue(stack_depth, tokenizer);
-    if (!value) return nullptr;
-    dict->setValue(key, std::move(value));
   }
-  tokenizer->Next();
-  return dict;
-}
 
+  // |status_.ok()| is the default; if we receive an error event
+  // we keep the first one and stop modifying any other state.
+  Status status_;
+
+  // The root of the parsed protocol::Value tree.
+  std::unique_ptr<Value> root_;
+
+  // If root_ is a list or a dictionary, this stack keeps track of
+  // the container we're currently parsing as well as its ancestors.
+  struct ContainerState {
+    ContainerState(DictionaryValue* dict) : is_dict(true), dict(dict) {}
+    ContainerState(ListValue* list) : is_dict(false), list(list) {}
+
+    bool is_dict;
+    union {
+      DictionaryValue* dict;
+      ListValue* list;
+    };
+  };
+  std::vector<ContainerState> stack_;
+
+  // For maps, keys and values are alternating events, so we keep the
+  // key around and process it when the value arrives.
+  bool key_is_pending_ = false;
+  String pending_key_;
+};
 } // anonymous namespace
 
 // static
 std::unique_ptr<Value> Value::parseBinary(const uint8_t* data, size_t size) {
-  span<uint8_t> bytes(data, size);
-
-  // Error::CBOR_NO_INPUT
-  if (bytes.empty()) return nullptr;
-
-  // Error::CBOR_INVALID_START_BYTE
-  if (bytes[0] != cbor::InitialByteForEnvelope()) return nullptr;
-
-  cbor::CBORTokenizer tokenizer(bytes);
-  if (tokenizer.TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) return nullptr;
-
-  // We checked for the envelope start byte above, so the tokenizer
-  // must agree here, since it's not an error.
-  DCHECK(tokenizer.TokenTag() == cbor::CBORTokenTag::ENVELOPE);
-  tokenizer.EnterEnvelope();
-  // Error::MAP_START_EXPECTED
-  if (tokenizer.TokenTag() != cbor::CBORTokenTag::MAP_START) return nullptr;
-  std::unique_ptr<Value> result = parseMap(/*stack_depth=*/1, &tokenizer);
-  if (!result) return nullptr;
-  if (tokenizer.TokenTag() == cbor::CBORTokenTag::DONE) return result;
-  if (tokenizer.TokenTag() == cbor::CBORTokenTag::ERROR_VALUE) return nullptr;
-  // Error::CBOR_TRAILING_JUNK
+  ValueParserHandler handler;
+  cbor::ParseCBOR(span<uint8_t>(data, size), &handler);
+  // TODO(johannes): We have decent error info in handler.status(); provide
+  // a richer interface that makes this available to client code.
+  if (handler.status().ok())
+    return handler.ReleaseRoot();
   return nullptr;
 }
 
@@ -500,7 +491,7 @@ std::unique_ptr<Value> DictionaryValue::clone() const
         DCHECK(value != m_data.cend() && value->second);
         result->setValue(key, value->second->clone());
     }
-    return std::move(result);
+    return result;
 }
 
 DictionaryValue::DictionaryValue()
@@ -528,7 +519,7 @@ std::unique_ptr<Value> ListValue::clone() const
     std::unique_ptr<ListValue> result = ListValue::create();
     for (const std::unique_ptr<protocol::Value>& value : m_data)
         result->pushValue(value->clone());
-    return std::move(result);
+    return result;
 }
 
 ListValue::ListValue()
diff --git a/deps/v8/third_party/inspector_protocol/lib/Values_h.template b/deps/v8/third_party/inspector_protocol/lib/Values_h.template
index 41d326e71e..8514123fb8 100644
--- a/deps/v8/third_party/inspector_protocol/lib/Values_h.template
+++ b/deps/v8/third_party/inspector_protocol/lib/Values_h.template
@@ -10,6 +10,8 @@
 //#include "Allocator.h"
 //#include "Forward.h"
 
+#include {{format_include(config.protocol.package, "Forward")}}
+
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
diff --git a/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template b/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
index edd3da99a9..b1ec1e475c 100644
--- a/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
+++ b/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_cc.template
@@ -1,4 +1,4 @@
-// This file is generated by DispatcherBase_cpp.template.
+// This file is generated by base_string_adapter_cc.template.
 
 // Copyright 2019 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
@@ -59,7 +59,7 @@ std::unique_ptr<protocol::Value> toProtocolValue(
       if (converted)
         result->pushValue(std::move(converted));
     }
-    return std::move(result);
+    return result;
   }
   if (value->is_dict()) {
     const base::DictionaryValue* dictionary = nullptr;
@@ -73,7 +73,7 @@ std::unique_ptr<protocol::Value> toProtocolValue(
       if (converted)
         result->setValue(it.key(), std::move(converted));
     }
-    return std::move(result);
+    return result;
   }
   return nullptr;
 }
@@ -112,7 +112,7 @@ std::unique_ptr<base::Value> toBaseValue(Value* value, int depth) {
       if (converted)
         result->Append(std::move(converted));
     }
-    return std::move(result);
+    return result;
   }
   if (value->type() == Value::TypeObject) {
     DictionaryValue* dict = DictionaryValue::cast(value);
@@ -124,35 +124,11 @@ std::unique_ptr<base::Value> toBaseValue(Value* value, int depth) {
       if (converted)
         result->SetWithoutPathExpansion(entry.first, std::move(converted));
     }
-    return std::move(result);
+    return result;
   }
   return nullptr;
 }
 
-StringBuilder::StringBuilder() {}
-
-StringBuilder::~StringBuilder() {}
-
-void StringBuilder::append(const std::string& s) {
-  string_ += s;
-}
-
-void StringBuilder::append(char c) {
-  string_ += c;
-}
-
-void StringBuilder::append(const char* characters, size_t length) {
-  string_.append(characters, length);
-}
-
-std::string StringBuilder::toString() {
-  return string_;
-}
-
-void StringBuilder::reserveCapacity(size_t capacity) {
-  string_.reserve(capacity);
-}
-
 // In Chromium, we do not support big endian architectures, so no conversion is needed
 // to interpret UTF16LE.
 // static
diff --git a/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_h.template b/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_h.template
index 32bd7ea233..ff40aba363 100644
--- a/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_h.template
+++ b/deps/v8/third_party/inspector_protocol/lib/base_string_adapter_h.template
@@ -1,4 +1,4 @@
-// This file is generated by Parser_h.template.
+// This file is generated by base_string_adapter_h.template.
 
 // Copyright 2019 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
@@ -14,7 +14,6 @@
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted_memory.h"
-#include "base/strings/string_number_conversions.h"
 #include "{{config.crdtp.dir}}/serializable.h"
 
 {% if config.lib.export_header %}
@@ -33,64 +32,8 @@ class Value;
 
 using String = std::string;
 
-class {{config.lib.export_macro}} StringBuilder {
- public:
-  StringBuilder();
-  ~StringBuilder();
-  void append(const String&);
-  void append(char);
-  void append(const char*, size_t);
-  String toString();
-  void reserveCapacity(size_t);
-
- private:
-  std::string string_;
-};
-
 class {{config.lib.export_macro}} StringUtil {
  public:
-  static String substring(const String& s, unsigned pos, unsigned len) {
-    return s.substr(pos, len);
-  }
-  static String fromInteger(int number) { return base::NumberToString(number); }
-  static String fromDouble(double number) {
-    String s = base::NumberToString(number);
-    if (!s.empty()) {  // .123 -> 0.123; -.123 -> -0.123 for valid JSON.
-      if (s[0] == '.')
-        s.insert(/*index=*/ 0, /*count=*/ 1, /*ch=*/ '0');
-      else if (s[0] == '-' && s.size() >= 2 && s[1] == '.')
-        s.insert(/*index=*/ 1, /*count=*/ 1, /*ch=*/ '0');
-    }
-    return s;
-  }
-  static double toDouble(const char* s, size_t len, bool* ok) {
-    double v = 0.0;
-    *ok = base::StringToDouble(std::string(s, len), &v);
-    return *ok ? v : 0.0;
-  }
-  static size_t find(const String& s, const char* needle) {
-    return s.find(needle);
-  }
-  static size_t find(const String& s, const String& needle) {
-    return s.find(needle);
-  }
-  static const size_t kNotFound = static_cast<size_t>(-1);
-  static void builderAppend(StringBuilder& builder, const String& s) {
-    builder.append(s);
-  }
-  static void builderAppend(StringBuilder& builder, char c) {
-    builder.append(c);
-  }
-  static void builderAppend(StringBuilder& builder, const char* s, size_t len) {
-    builder.append(s, len);
-  }
-  static void builderReserve(StringBuilder& builder, unsigned capacity) {
-    builder.reserveCapacity(capacity);
-  }
-  static String builderToString(StringBuilder& builder) {
-    return builder.toString();
-  }
-
   static String fromUTF8(const uint8_t* data, size_t length) {
     return std::string(reinterpret_cast<const char*>(data), length);
   }
diff --git a/deps/v8/third_party/inspector_protocol/roll.py b/deps/v8/third_party/inspector_protocol/roll.py
index ccf887a4d3..85765d4350 100755
--- a/deps/v8/third_party/inspector_protocol/roll.py
+++ b/deps/v8/third_party/inspector_protocol/roll.py
@@ -21,6 +21,16 @@ FILES_TO_SYNC = [
     'crdtp/cbor.cc',
     'crdtp/cbor.h',
     'crdtp/cbor_test.cc',
+    'crdtp/dispatch.h',
+    'crdtp/dispatch.cc',
+    'crdtp/dispatch_test.cc',
+    'crdtp/error_support.cc',
+    'crdtp/error_support.h',
+    'crdtp/error_support_test.cc',
+    'crdtp/export_template.h',
+    'crdtp/find_by_first.h',
+    'crdtp/find_by_first_test.cc',
+    'crdtp/frontend_channel.h',
     'crdtp/glue.h',
     'crdtp/glue_test.cc',
     'crdtp/json.cc',
@@ -33,6 +43,7 @@ FILES_TO_SYNC = [
     'crdtp/serializable_test.cc',
     'crdtp/serializer_traits.h',
     'crdtp/serializer_traits_test.cc',
+    'crdtp/span.cc',
     'crdtp/span.h',
     'crdtp/span_test.cc',
     'crdtp/status.cc',
diff --git a/deps/v8/third_party/inspector_protocol/templates/Imported_h.template b/deps/v8/third_party/inspector_protocol/templates/Imported_h.template
index b549388c8a..bb1dcf4a20 100644
--- a/deps/v8/third_party/inspector_protocol/templates/Imported_h.template
+++ b/deps/v8/third_party/inspector_protocol/templates/Imported_h.template
@@ -52,7 +52,7 @@ struct ValueConversions<{{"::".join(config.imported.namespace)}}::{{domain.domai
     static std::unique_ptr<{{"::".join(config.imported.namespace)}}::{{domain.domain}}::API::{{type.id}}> fromValue(protocol::Value* value, ErrorSupport* errors)
     {
         if (!value) {
-            errors->addError("value expected");
+            errors->AddError("value expected");
             return nullptr;
         }
 
@@ -60,7 +60,7 @@ struct ValueConversions<{{"::".join(config.imported.namespace)}}::{{domain.domai
         value->AppendSerialized(&binary);
         auto result = {{"::".join(config.imported.namespace)}}::{{domain.domain}}::API::{{type.id}}::fromBinary(binary.data(), binary.size());
         if (!result)
-            errors->addError("cannot parse");
+            errors->AddError("cannot parse");
         return result;
     }
 
diff --git a/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_cpp.template b/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_cpp.template
index eabafba755..f0a3d3ccaf 100644
--- a/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_cpp.template
+++ b/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_cpp.template
@@ -9,7 +9,9 @@
 #include {{format_include(config.protocol.package, "Protocol")}}
 
 #include "{{config.crdtp.dir}}/cbor.h"
+#include "{{config.crdtp.dir}}/find_by_first.h"
 #include "{{config.crdtp.dir}}/serializer_traits.h"
+#include "{{config.crdtp.dir}}/span.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
@@ -54,27 +56,27 @@ const char* {{type.id}}::{{property.name | to_title_case}}Enum::{{literal | dash
 std::unique_ptr<{{type.id}}> {{type.id}}::fromValue(protocol::Value* value, ErrorSupport* errors)
 {
     if (!value || value->type() != protocol::Value::TypeObject) {
-        errors->addError("object expected");
+        errors->AddError("object expected");
         return nullptr;
     }
 
     std::unique_ptr<{{type.id}}> result(new {{type.id}}());
     protocol::DictionaryValue* object = DictionaryValue::cast(value);
-    errors->push();
+    errors->Push();
     {% for property in type.properties %}
     protocol::Value* {{property.name}}Value = object->get("{{property.name}}");
       {% if property.optional %}
     if ({{property.name}}Value) {
-        errors->setName("{{property.name}}");
+        errors->SetName("{{property.name}}");
         result->m_{{property.name}} = ValueConversions<{{protocol.resolve_type(property).raw_type}}>::fromValue({{property.name}}Value, errors);
     }
       {% else %}
-    errors->setName("{{property.name}}");
+    errors->SetName("{{property.name}}");
     result->m_{{property.name}} = ValueConversions<{{protocol.resolve_type(property).raw_type}}>::fromValue({{property.name}}Value, errors);
       {% endif %}
     {% endfor %}
-    errors->pop();
-    if (errors->hasErrors())
+    errors->Pop();
+    if (!errors->Errors().empty())
         return nullptr;
     return result;
 }
@@ -169,7 +171,7 @@ void Frontend::{{event.name | to_method_case}}(
       {%- endif %} {{parameter.name}}{%- if not loop.last -%}, {% endif -%}
     {% endfor -%})
 {
-    if (!m_frontendChannel)
+    if (!frontend_channel_)
         return;
       {% if event.parameters %}
     std::unique_ptr<{{event.name | to_title_case}}Notification> messageData = {{event.name | to_title_case}}Notification::{{"create" | to_method_case}}()
@@ -185,69 +187,79 @@ void Frontend::{{event.name | to_method_case}}(
         messageData->{{"set" | to_method_case}}{{parameter.name | to_title_case}}(std::move({{parameter.name}}).takeJust());
           {% endif %}
         {% endfor %}
-    m_frontendChannel->sendProtocolNotification(InternalResponse::createNotification("{{domain.domain}}.{{event.name}}", std::move(messageData)));
+    frontend_channel_->SendProtocolNotification({{config.crdtp.namespace}}::CreateNotification("{{domain.domain}}.{{event.name}}", std::move(messageData)));
       {% else %}
-    m_frontendChannel->sendProtocolNotification(InternalResponse::createNotification("{{domain.domain}}.{{event.name}}"));
+    frontend_channel_->SendProtocolNotification({{config.crdtp.namespace}}::CreateNotification("{{domain.domain}}.{{event.name}}"));
       {% endif %}
 }
   {% endfor %}
 
 void Frontend::flush()
 {
-    m_frontendChannel->flushProtocolNotifications();
+    frontend_channel_->FlushProtocolNotifications();
 }
 
-void Frontend::sendRawCBORNotification(std::vector<uint8_t> notification)
+void Frontend::sendRawNotification(std::unique_ptr<Serializable> notification)
 {
-    m_frontendChannel->sendProtocolNotification(InternalRawNotification::fromBinary(std::move(notification)));
+    frontend_channel_->SendProtocolNotification(std::move(notification));
 }
 
 // --------------------- Dispatcher.
 
-class DispatcherImpl : public protocol::DispatcherBase {
+class DomainDispatcherImpl : public protocol::DomainDispatcher {
 public:
-    DispatcherImpl(FrontendChannel* frontendChannel, Backend* backend)
-        : DispatcherBase(frontendChannel)
-        , m_backend(backend) {
-  {% for command in domain.commands %}
-    {% if "redirect" in command %}
-      m_redirects["{{domain.domain}}.{{command.name}}"] = "{{command.redirect}}.{{command.name}}";
-      {% continue %}
-    {% endif %}
-    {% if not protocol.generate_command(domain.domain, command.name) %}{% continue %}{% endif %}
-        m_dispatchMap["{{domain.domain}}.{{command.name}}"] = &DispatcherImpl::{{command.name}};
-  {% endfor %}
-    }
-    ~DispatcherImpl() override { }
-    bool canDispatch(const String& method) override;
-    void dispatch(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message, std::unique_ptr<protocol::DictionaryValue> messageObject) override;
-    std::unordered_map<String, String>& redirects() { return m_redirects; }
+    DomainDispatcherImpl(FrontendChannel* frontendChannel, Backend* backend)
+        : DomainDispatcher(frontendChannel)
+        , m_backend(backend) {}
+    ~DomainDispatcherImpl() override { }
+
+    using CallHandler = void (DomainDispatcherImpl::*)(const {{config.crdtp.namespace}}::Dispatchable& dispatchable, DictionaryValue* params, ErrorSupport* errors);
 
-protected:
-    using CallHandler = void (DispatcherImpl::*)(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message, std::unique_ptr<DictionaryValue> messageObject, ErrorSupport* errors);
-    using DispatchMap = std::unordered_map<String, CallHandler>;
-    DispatchMap m_dispatchMap;
-    std::unordered_map<String, String> m_redirects;
+    std::function<void(const {{config.crdtp.namespace}}::Dispatchable&)> Dispatch({{config.crdtp.namespace}}::span<uint8_t> command_name) override;
 
   {% for command in domain.commands %}
     {% if "redirect" in command %}{% continue %}{% endif %}
     {% if not protocol.generate_command(domain.domain, command.name) %}{% continue %}{% endif %}
-    void {{command.name}}(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message, std::unique_ptr<DictionaryValue> requestMessageObject, ErrorSupport*);
+    void {{command.name}}(const {{config.crdtp.namespace}}::Dispatchable& dispatchable, DictionaryValue* params, ErrorSupport* errors);
   {% endfor %}
-
+ protected:
     Backend* m_backend;
 };
 
-bool DispatcherImpl::canDispatch(const String& method) {
-    return m_dispatchMap.find(method) != m_dispatchMap.end();
+namespace {
+// This helper method with a static map of command methods (instance methods
+// of DomainDispatcherImpl declared just above) by their name is used immediately below,
+// in the DomainDispatcherImpl::Dispatch method.
+DomainDispatcherImpl::CallHandler CommandByName({{config.crdtp.namespace}}::span<uint8_t> command_name) {
+  static auto* commands = [](){
+    auto* commands = new std::vector<std::pair<{{config.crdtp.namespace}}::span<uint8_t>,
+                              DomainDispatcherImpl::CallHandler>>{
+      {% for command in domain.commands|sort(attribute="name",case_sensitive=True) %}
+        {% if "redirect" in command %}{% continue %}{% endif %}
+        {% if not protocol.generate_command(domain.domain, command.name) %}{% continue %}{% endif %}
+    {
+          {{config.crdtp.namespace}}::SpanFrom("{{command.name}}"),
+          &DomainDispatcherImpl::{{command.name}}
+    },
+      {% endfor %}
+    };
+    return commands;
+  }();
+  return {{config.crdtp.namespace}}::FindByFirst<DomainDispatcherImpl::CallHandler>(*commands, command_name, nullptr);
 }
-
-void DispatcherImpl::dispatch(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message, std::unique_ptr<protocol::DictionaryValue> messageObject)
-{
-    std::unordered_map<String, CallHandler>::iterator it = m_dispatchMap.find(method);
-    DCHECK(it != m_dispatchMap.end());
-    protocol::ErrorSupport errors;
-    (this->*(it->second))(callId, method, message, std::move(messageObject), &errors);
+}  // namespace
+
+std::function<void(const {{config.crdtp.namespace}}::Dispatchable&)> DomainDispatcherImpl::Dispatch({{config.crdtp.namespace}}::span<uint8_t> command_name) {
+  CallHandler handler = CommandByName(command_name);
+  if (!handler) return nullptr;
+  return [this, handler](const {{config.crdtp.namespace}}::Dispatchable& dispatchable){
+    std::unique_ptr<DictionaryValue> params =
+        DictionaryValue::cast(protocol::Value::parseBinary(dispatchable.Params().data(),
+        dispatchable.Params().size()));
+    ErrorSupport errors;
+    errors.Push();
+    (this->*handler)(dispatchable, params.get(), &errors);
+  };
 }
 
   {% for command in domain.commands %}
@@ -256,10 +268,11 @@ void DispatcherImpl::dispatch(int callId, const String& method, {{config.crdtp.n
     {% if not protocol.generate_command(domain.domain, command.name) %}{% continue %}{% endif %}
     {% if protocol.is_async_command(domain.domain, command.name) %}
 
-class {{command_name_title}}CallbackImpl : public Backend::{{command_name_title}}Callback, public DispatcherBase::Callback {
+class {{command_name_title}}CallbackImpl : public Backend::{{command_name_title}}Callback, public DomainDispatcher::Callback {
 public:
-    {{command_name_title}}CallbackImpl(std::unique_ptr<DispatcherBase::WeakPtr> backendImpl, int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message)
-        : DispatcherBase::Callback(std::move(backendImpl), callId, method, message) { }
+    {{command_name_title}}CallbackImpl(std::unique_ptr<DomainDispatcher::WeakPtr> backendImpl, int callId, {{config.crdtp.namespace}}::span<uint8_t> message)
+        : DomainDispatcher::Callback(std::move(backendImpl), callId,
+{{config.crdtp.namespace}}::SpanFrom("{{domain.domain}}.{{command.name}}"), message) { }
 
     void sendSuccess(
       {%- for parameter in command.returns -%}
@@ -271,16 +284,16 @@ public:
         {%- if not loop.last -%}, {% endif -%}
       {%- endfor -%}) override
     {
-        std::unique_ptr<protocol::DictionaryValue> resultObject = DictionaryValue::create();
-          {% for parameter in command.returns %}
-            {% if "optional" in parameter %}
-        if ({{parameter.name}}.isJust())
-            resultObject->setValue("{{parameter.name}}", ValueConversions<{{protocol.resolve_type(parameter).raw_type}}>::toValue({{parameter.name}}.fromJust()));
-           {% else %}
-        resultObject->setValue("{{parameter.name}}", ValueConversions<{{protocol.resolve_type(parameter).raw_type}}>::toValue({{protocol.resolve_type(parameter).to_raw_type % parameter.name}}));
-            {% endif %}
-          {% endfor %}
-        sendIfActive(std::move(resultObject), DispatchResponse::OK());
+        std::vector<uint8_t> result_buffer;
+        {{config.crdtp.namespace}}::cbor::EnvelopeEncoder envelope_encoder;
+        envelope_encoder.EncodeStart(&result_buffer);
+        result_buffer.push_back({{config.crdtp.namespace}}::cbor::EncodeIndefiniteLengthMapStart());
+        {% for parameter in command.returns %}
+          {{config.crdtp.namespace}}::SerializeField({{config.crdtp.namespace}}::SpanFrom("{{parameter.name}}"), {{parameter.name}}, &result_buffer);
+        {% endfor %}
+        result_buffer.push_back({{config.crdtp.namespace}}::cbor::EncodeStop());
+        envelope_encoder.EncodeStop(&result_buffer);
+        sendIfActive({{config.crdtp.namespace}}::Serializable::From(std::move(result_buffer)), DispatchResponse::Success());
     }
 
     void fallThrough() override
@@ -290,37 +303,31 @@ public:
 
     void sendFailure(const DispatchResponse& response) override
     {
-        DCHECK(response.status() == DispatchResponse::kError);
+        DCHECK(response.IsError());
         sendIfActive(nullptr, response);
     }
 };
     {% endif %}
 
-void DispatcherImpl::{{command.name}}(int callId, const String& method, {{config.crdtp.namespace}}::span<uint8_t> message, std::unique_ptr<DictionaryValue> requestMessageObject, ErrorSupport* errors)
+void DomainDispatcherImpl::{{command.name}}(const {{config.crdtp.namespace}}::Dispatchable& dispatchable, DictionaryValue* params, ErrorSupport* errors)
 {
     {% if "parameters" in command %}
     // Prepare input parameters.
-    protocol::DictionaryValue* object = DictionaryValue::cast(requestMessageObject->get("params"));
-    errors->push();
       {% for parameter in command.parameters %}
         {% set parameter_type = protocol.resolve_type(parameter) %}
-    protocol::Value* {{parameter.name}}Value = object ? object->get("{{parameter.name}}") : nullptr;
+    protocol::Value* {{parameter.name}}Value = params ? params->get("{{parameter.name}}") : nullptr;
         {% if parameter.optional %}
     Maybe<{{parameter_type.raw_type}}> in_{{parameter.name}};
     if ({{parameter.name}}Value) {
-        errors->setName("{{parameter.name}}");
+        errors->SetName("{{parameter.name}}");
         in_{{parameter.name}} = ValueConversions<{{parameter_type.raw_type}}>::fromValue({{parameter.name}}Value, errors);
     }
         {% else %}
-    errors->setName("{{parameter.name}}");
+    errors->SetName("{{parameter.name}}");
     {{parameter_type.type}} in_{{parameter.name}} = ValueConversions<{{parameter_type.raw_type}}>::fromValue({{parameter.name}}Value, errors);
         {% endif %}
       {% endfor %}
-    errors->pop();
-    if (errors->hasErrors()) {
-        reportProtocolError(callId, DispatchResponse::kInvalidParams, kInvalidParamsString, errors);
-        return;
-    }
+    if (MaybeReportInvalidParams(dispatchable, *errors)) return;
     {% endif %}
     {% if "returns" in command and not protocol.is_async_command(domain.domain, command.name) %}
     // Declare output parameters.
@@ -334,7 +341,7 @@ void DispatcherImpl::{{command.name}}(int callId, const String& method, {{config
     {% endif %}
 
     {% if not protocol.is_async_command(domain.domain, command.name) %}
-    std::unique_ptr<DispatcherBase::WeakPtr> weak = weakPtr();
+    std::unique_ptr<DomainDispatcher::WeakPtr> weak = weakPtr();
     DispatchResponse response = m_backend->{{command.name | to_method_case}}(
       {%- for parameter in command.parameters -%}
         {%- if not loop.first -%}, {% endif -%}
@@ -350,31 +357,31 @@ void DispatcherImpl::{{command.name}}(int callId, const String& method, {{config
           &out_{{parameter.name}}
         {%- endfor %}
       {% endif %});
-    if (response.status() == DispatchResponse::kFallThrough) {
-        channel()->fallThrough(callId, method, message);
+    if (response.IsFallThrough()) {
+        channel()->FallThrough(dispatchable.CallId(), {{config.crdtp.namespace}}::SpanFrom("{{domain.domain}}.{{command.name}}"), dispatchable.Serialized());
         return;
     }
       {% if "returns" in command %}
-    std::unique_ptr<protocol::DictionaryValue> result = DictionaryValue::create();
-    if (response.status() == DispatchResponse::kSuccess) {
-        {% for parameter in command.returns %}
-          {% if "optional" in parameter %}
-        if (out_{{parameter.name}}.isJust())
-            result->setValue("{{parameter.name}}", ValueConversions<{{protocol.resolve_type(parameter).raw_type}}>::toValue(out_{{parameter.name}}.fromJust()));
-          {% else %}
-        result->setValue("{{parameter.name}}", ValueConversions<{{protocol.resolve_type(parameter).raw_type}}>::toValue({{protocol.resolve_type(parameter).to_raw_type % ("out_" + parameter.name)}}));
-          {% endif %}
-        {% endfor %}
-    }
-    if (weak->get())
-        weak->get()->sendResponse(callId, response, std::move(result));
+      if (weak->get()) {
+        std::vector<uint8_t> result;
+        if (response.IsSuccess()) {
+          {{config.crdtp.namespace}}::cbor::EnvelopeEncoder envelope_encoder;
+          envelope_encoder.EncodeStart(&result);
+          result.push_back({{config.crdtp.namespace}}::cbor::EncodeIndefiniteLengthMapStart());
+          {% for parameter in command.returns %}
+            {{config.crdtp.namespace}}::SerializeField({{config.crdtp.namespace}}::SpanFrom("{{parameter.name}}"), out_{{parameter.name}}, &result);
+          {% endfor %}
+          result.push_back({{config.crdtp.namespace}}::cbor::EncodeStop());
+          envelope_encoder.EncodeStop(&result);
+        }
+        weak->get()->sendResponse(dispatchable.CallId(), response, {{config.crdtp.namespace}}::Serializable::From(std::move(result)));
+      }
       {% else %}
     if (weak->get())
-        weak->get()->sendResponse(callId, response);
+        weak->get()->sendResponse(dispatchable.CallId(), response);
       {% endif %}
     return;
     {% else %}
-    std::unique_ptr<{{command_name_title}}CallbackImpl> callback(new {{command.name | to_title_case}}CallbackImpl(weakPtr(), callId, method, message));
     m_backend->{{command.name | to_method_case}}(
       {%- for property in command.parameters -%}
         {%- if not loop.first -%}, {% endif -%}
@@ -385,18 +392,34 @@ void DispatcherImpl::{{command.name}}(int callId, const String& method, {{config
         {%- endif -%}
       {%- endfor -%}
         {%- if command.parameters -%}, {% endif -%}
-        std::move(callback));
-    return;
+        std::make_unique<{{command_name_title}}CallbackImpl>(weakPtr(), dispatchable.CallId(), dispatchable.Serialized()));
     {% endif %}
 }
   {% endfor %}
 
+namespace {
+// This helper method (with a static map of redirects) is used from Dispatcher::wire
+// immediately below.
+const std::vector<std::pair<{{config.crdtp.namespace}}::span<uint8_t>, {{config.crdtp.namespace}}::span<uint8_t>>>& SortedRedirects() {
+  static auto* redirects = [](){
+    auto* redirects = new std::vector<std::pair<{{config.crdtp.namespace}}::span<uint8_t>, {{config.crdtp.namespace}}::span<uint8_t>>>{
+      {% for command in domain.commands|sort(attribute="name",case_sensitive=True) %}
+        {% if "redirect" in command %}
+          { {{config.crdtp.namespace}}::SpanFrom("{{domain.domain}}.{{command.name}}"), {{config.crdtp.namespace}}::SpanFrom("{{command.redirect}}.{{command.name}}") },
+        {% endif %}
+      {% endfor %}
+    };
+    return redirects;
+  }();
+  return *redirects;
+}
+}  // namespace
+
 // static
 void Dispatcher::wire(UberDispatcher* uber, Backend* backend)
 {
-    std::unique_ptr<DispatcherImpl> dispatcher(new DispatcherImpl(uber->channel(), backend));
-    uber->setupRedirects(dispatcher->redirects());
-    uber->registerBackend("{{domain.domain}}", std::move(dispatcher));
+    auto dispatcher = std::make_unique<DomainDispatcherImpl>(uber->channel(), backend);
+    uber->WireBackend({{config.crdtp.namespace}}::SpanFrom("{{domain.domain}}"), SortedRedirects(), std::move(dispatcher));
 }
 
 } // {{domain.domain}}
diff --git a/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_h.template b/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_h.template
index 08615f8828..bc3998e4a2 100644
--- a/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_h.template
+++ b/deps/v8/third_party/inspector_protocol/templates/TypeBuilder_h.template
@@ -239,7 +239,7 @@ public:
   {% if protocol.generate_disable(domain) %}
     virtual DispatchResponse {{"disable" | to_method_case}}()
     {
-        return DispatchResponse::OK();
+        return DispatchResponse::Success();
     }
   {% endif %}
 };
@@ -248,7 +248,7 @@ public:
 
 class {{config.protocol.export_macro}} Frontend {
 public:
-    explicit Frontend(FrontendChannel* frontendChannel) : m_frontendChannel(frontendChannel) { }
+  explicit Frontend(FrontendChannel* frontend_channel) : frontend_channel_(frontend_channel) {}
   {% for event in domain.events %}
     {% if not protocol.generate_event(domain.domain, event.name) %}{% continue %}{% endif %}
     void {{event.name | to_method_case}}(
@@ -262,10 +262,10 @@ public:
     );
   {% endfor %}
 
-    void flush();
-    void sendRawCBORNotification(std::vector<uint8_t>);
-private:
-    FrontendChannel* m_frontendChannel;
+  void flush();
+  void sendRawNotification(std::unique_ptr<Serializable>);
+ private:
+  FrontendChannel* frontend_channel_;
 };
 
 // ------------- Dispatcher.
diff --git a/deps/v8/third_party/v8/builtins/array-sort.tq b/deps/v8/third_party/v8/builtins/array-sort.tq
index d920599e6e..2d9f33a312 100644
--- a/deps/v8/third_party/v8/builtins/array-sort.tq
+++ b/deps/v8/third_party/v8/builtins/array-sort.tq
@@ -14,7 +14,7 @@
 // https://github.com/python/cpython/blob/master/Objects/listsort.txt
 
 namespace array {
-  class SortState extends Struct {
+  class SortState extends HeapObject {
     macro Compare(implicit context: Context)(x: JSAny, y: JSAny): Number {
       const sortCompare: CompareBuiltinFn = this.sortComparePtr;
       return sortCompare(context, this.userCmpFn, x, y);
diff --git a/deps/v8/third_party/zlib/BUILD.gn b/deps/v8/third_party/zlib/BUILD.gn
index 2414c8826f..1f572378e0 100644
--- a/deps/v8/third_party/zlib/BUILD.gn
+++ b/deps/v8/third_party/zlib/BUILD.gn
@@ -17,7 +17,10 @@ config("zlib_internal_config") {
 }
 
 use_arm_neon_optimizations = false
-if (current_cpu == "arm" || current_cpu == "arm64") {
+if ((current_cpu == "arm" || current_cpu == "arm64") &&
+    !(is_win && !is_clang)) {
+  # TODO(richard.townsend@arm.com): Optimizations temporarily disabled for
+  # Windows on Arm MSVC builds, see http://crbug.com/v8/10012.
   if (arm_use_neon) {
     use_arm_neon_optimizations = true
   }
diff --git a/deps/v8/third_party/zlib/contrib/minizip/iowin32.c b/deps/v8/third_party/zlib/contrib/minizip/iowin32.c
index 246ceb91a1..c6bc314b3c 100644
--- a/deps/v8/third_party/zlib/contrib/minizip/iowin32.c
+++ b/deps/v8/third_party/zlib/contrib/minizip/iowin32.c
@@ -31,14 +31,12 @@
 #define _WIN32_WINNT 0x601
 #endif
 
-#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
-// see Include/shared/winapifamily.h in the Windows Kit
-#if defined(WINAPI_FAMILY_PARTITION) && (!(defined(IOWIN32_USING_WINRT_API)))
-#if WINAPI_FAMILY_ONE_PARTITION(WINAPI_FAMILY, WINAPI_PARTITION_APP)
+#if !defined(IOWIN32_USING_WINRT_API)
+#if defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP)
+// Windows Store or Universal Windows Platform
 #define IOWIN32_USING_WINRT_API 1
 #endif
 #endif
-#endif
 
 voidpf  ZCALLBACK win32_open_file_func  OF((voidpf opaque, const char* filename, int mode));
 uLong   ZCALLBACK win32_read_file_func  OF((voidpf opaque, voidpf stream, void* buf, uLong size));
diff --git a/deps/v8/third_party/zlib/cpu_features.c b/deps/v8/third_party/zlib/cpu_features.c
index 8a25dd29c8..ceed98822a 100644
--- a/deps/v8/third_party/zlib/cpu_features.c
+++ b/deps/v8/third_party/zlib/cpu_features.c
@@ -22,6 +22,8 @@ int ZLIB_INTERNAL arm_cpu_enable_pmull = 0;
 int ZLIB_INTERNAL x86_cpu_enable_ssse3 = 0;
 int ZLIB_INTERNAL x86_cpu_enable_simd = 0;
 
+#ifndef CPU_NO_SIMD
+
 #if defined(ARMV8_OS_ANDROID) || defined(ARMV8_OS_LINUX) || defined(ARMV8_OS_FUCHSIA)
 #include <pthread.h>
 #endif
@@ -143,3 +145,4 @@ static void _cpu_check_features(void)
 }
 #endif
 #endif
+#endif
\ No newline at end of file
diff --git a/deps/v8/third_party/zlib/crc32_simd.h b/deps/v8/third_party/zlib/crc32_simd.h
index 315c2a45f4..68bc235cbe 100644
--- a/deps/v8/third_party/zlib/crc32_simd.h
+++ b/deps/v8/third_party/zlib/crc32_simd.h
@@ -33,3 +33,4 @@ uint32_t ZLIB_INTERNAL crc32_sse42_simd_(
 uint32_t ZLIB_INTERNAL armv8_crc32_little(unsigned long crc,
                                           const unsigned char* buf,
                                           z_size_t len);
+
diff --git a/deps/v8/third_party/zlib/deflate.c b/deps/v8/third_party/zlib/deflate.c
index a20c42af7a..744d8558e2 100644
--- a/deps/v8/third_party/zlib/deflate.c
+++ b/deps/v8/third_party/zlib/deflate.c
@@ -1213,7 +1213,7 @@ ZLIB_INTERNAL unsigned deflate_read_buf(strm, buf, size)
 #ifdef GZIP
     if (strm->state->wrap == 2)
         copy_with_crc(strm, buf, len);
-    else
+    else 
 #endif
     {
         zmemcpy(buf, strm->next_in, len);
diff --git a/deps/v8/third_party/zlib/patches/0000-build.patch b/deps/v8/third_party/zlib/patches/0000-build.patch
index 1e005375f5..b7c5996482 100644
--- a/deps/v8/third_party/zlib/patches/0000-build.patch
+++ b/deps/v8/third_party/zlib/patches/0000-build.patch
@@ -3,12 +3,12 @@ index 8dcbdb06e35a..c1b7a54847f5 100644
 --- a/contrib/minizip/ioapi.h
 +++ b/contrib/minizip/ioapi.h
 @@ -43,7 +43,7 @@
-
+ 
  #include <stdio.h>
  #include <stdlib.h>
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
-
+ 
  #if defined(USE_FILE32API)
  #define fopen64 fopen
 diff --git a/contrib/minizip/iowin32.c b/contrib/minizip/iowin32.c
@@ -17,8 +17,8 @@ index 274f39eb1dd2..246ceb91a139 100644
 +++ b/contrib/minizip/iowin32.c
 @@ -26,12 +26,19 @@
  #endif
-
-
+ 
+ 
 +#ifdef _WIN32_WINNT
 +#undef _WIN32_WINNT
 +#define _WIN32_WINNT 0x601
@@ -32,7 +32,7 @@ index 274f39eb1dd2..246ceb91a139 100644
  #endif
  #endif
 +#endif
-
+ 
  voidpf  ZCALLBACK win32_open_file_func  OF((voidpf opaque, const char* filename, int mode));
  uLong   ZCALLBACK win32_read_file_func  OF((voidpf opaque, voidpf stream, void* buf, uLong size));
 diff --git a/contrib/minizip/mztools.c b/contrib/minizip/mztools.c
@@ -46,7 +46,7 @@ index 96891c2e0b71..8bf9cca32633 100644
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #include "unzip.h"
-
+ 
  #define READ_8(adr)  ((unsigned char)*(adr))
 diff --git a/contrib/minizip/mztools.h b/contrib/minizip/mztools.h
 index a49a426ec2fc..f295ffeda6af 100644
@@ -54,12 +54,12 @@ index a49a426ec2fc..f295ffeda6af 100644
 +++ b/contrib/minizip/mztools.h
 @@ -12,7 +12,7 @@ extern "C" {
  #endif
-
+ 
  #ifndef _ZLIB_H
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #endif
-
+ 
  #include "unzip.h"
 diff --git a/contrib/minizip/unzip.c b/contrib/minizip/unzip.c
 index bcfb9416ec35..199b4723fcfc 100644
@@ -68,16 +68,16 @@ index bcfb9416ec35..199b4723fcfc 100644
 @@ -72,7 +72,7 @@
          #define NOUNCRYPT
  #endif
-
+ 
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #include "unzip.h"
-
+ 
  #ifdef STDC
 @@ -1705,11 +1705,6 @@ extern int ZEXPORT unzReadCurrentFile  (unzFile file, voidp buf, unsigned len)
-
+ 
      pfile_in_zip_read_info->stream.avail_out = (uInt)len;
-
+ 
 -    if ((len>pfile_in_zip_read_info->rest_read_uncompressed) &&
 -        (!(pfile_in_zip_read_info->raw)))
 -        pfile_in_zip_read_info->stream.avail_out =
@@ -92,12 +92,12 @@ index 2104e3915074..3c0143529b91 100644
 +++ b/contrib/minizip/unzip.h
 @@ -48,7 +48,7 @@ extern "C" {
  #endif
-
+ 
  #ifndef _ZLIB_H
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #endif
-
+ 
  #ifndef  _ZLIBIOAPI_H
 diff --git a/contrib/minizip/zip.c b/contrib/minizip/zip.c
 index 44e88a9cb989..65c0c7251843 100644
@@ -110,7 +110,7 @@ index 44e88a9cb989..65c0c7251843 100644
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #include "zip.h"
-
+ 
  #ifdef STDC
 diff --git a/contrib/minizip/zip.h b/contrib/minizip/zip.h
 index 8aaebb623430..8c06c0aa7bb0 100644
@@ -118,12 +118,12 @@ index 8aaebb623430..8c06c0aa7bb0 100644
 +++ b/contrib/minizip/zip.h
 @@ -47,7 +47,7 @@ extern "C" {
  //#define HAVE_BZIP2
-
+ 
  #ifndef _ZLIB_H
 -#include "zlib.h"
 +#include "third_party/zlib/zlib.h"
  #endif
-
+ 
  #ifndef _ZLIBIOAPI_H
 diff --git a/gzread.c b/gzread.c
 index 956b91ea7d9e..832d3ef98c59 100644
@@ -148,7 +148,7 @@ index 5e1d68a004e9..a7a815f575a7 100644
 @@ -8,6 +8,10 @@
  #ifndef ZCONF_H
  #define ZCONF_H
-
+ 
 +/*
 + * This library is also built as a part of AOSP, which does not need to include
 + * chromeconf.h. This config does not want chromeconf.h, so it can set this
@@ -167,12 +167,12 @@ index 5e1d68a004e9..a7a815f575a7 100644
 @@ -431,7 +434,7 @@ typedef uLong FAR uLongf;
     typedef unsigned long z_crc_t;
  #endif
-
+ 
 -#ifdef HAVE_UNISTD_H    /* may be set to #if 1 by ./configure */
 +#if !defined(_WIN32)
  #  define Z_HAVE_UNISTD_H
  #endif
-
+ 
 diff --git a/zlib.h b/zlib.h
 index f09cdaf1e054..99fd467f6b1a 100644
 --- a/zlib.h
@@ -242,6 +242,6 @@ index b079ea6a80f5..80375b8b6109 100644
 +#    include <errno.h>
 +#  endif
 +#endif
-
+ 
  #ifdef Z_SOLO
     typedef long ptrdiff_t;  /* guess -- will be caught if guess is wrong */
diff --git a/deps/v8/third_party/zlib/patches/0001-simd.patch b/deps/v8/third_party/zlib/patches/0001-simd.patch
index 5e88c46bb8..9434ca0cc4 100644
--- a/deps/v8/third_party/zlib/patches/0001-simd.patch
+++ b/deps/v8/third_party/zlib/patches/0001-simd.patch
@@ -5,11 +5,11 @@ index 9580440c0e6b..9162429cc7b4 100644
 @@ -28,6 +28,8 @@
  #  endif /* !DYNAMIC_CRC_TABLE */
  #endif /* MAKECRCH */
-
+ 
 +#include "deflate.h"
 +#include "x86.h"
  #include "zutil.h"      /* for STDC and FAR definitions */
-
+ 
  /* Definitions for doing the crc four data bytes at a time. */
 @@ -440,3 +442,28 @@ uLong ZEXPORT crc32_combine64(crc1, crc2, len2)
  {
@@ -545,13 +545,13 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 +++ b/deflate.c
 @@ -48,8 +48,9 @@
   */
-
+ 
  /* @(#) $Id$ */
 -
 +#include <assert.h>
  #include "deflate.h"
 +#include "x86.h"
-
+ 
  const char deflate_copyright[] =
     " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
 @@ -86,7 +87,7 @@ local block_state deflate_huff   OF((deflate_state *s, int flush));
@@ -566,7 +566,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 @@ -100,6 +101,20 @@ local  void check_match OF((deflate_state *s, IPos start, IPos match,
                              int length));
  #endif
-
+ 
 +/* From crc32.c */
 +extern void ZLIB_INTERNAL crc_reset(deflate_state *const s);
 +extern void ZLIB_INTERNAL crc_finalize(deflate_state *const s);
@@ -587,7 +587,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 @@ -162,7 +177,6 @@ local const config configuration_table[10] = {
   */
  #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
-
+ 
 -
  /* ===========================================================================
   * Insert string str in the dictionary and set match_head to the previous head
@@ -626,7 +626,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 +    return insert_string_c(s, str);
 +}
 +
-
+ 
  /* ===========================================================================
   * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
 @@ -248,6 +273,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
@@ -640,7 +640,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 @@ -257,6 +283,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
       * output size for (length,distance) codes is <= 24 bits.
       */
-
+ 
 +    x86_check_features();
 +
      if (version == Z_NULL || version[0] != my_version[0] ||
@@ -649,7 +649,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 @@ -313,12 +341,19 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
      s->w_size = 1 << s->w_bits;
      s->w_mask = s->w_size - 1;
-
+ 
 -    s->hash_bits = (uInt)memLevel + 7;
 +    if (x86_cpu_enable_simd) {
 +        s->hash_bits = 15;
@@ -660,14 +660,14 @@ index 1ec761448de9..aa0c9c67a6dc 100644
      s->hash_size = 1 << s->hash_bits;
      s->hash_mask = s->hash_size - 1;
      s->hash_shift =  ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
-
+ 
 -    s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
 +    s->window = (Bytef *) ZALLOC(strm,
 +                                 s->w_size + window_padding,
 +                                 2*sizeof(Byte));
      s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
      s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
-
+ 
 @@ -418,11 +453,7 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
          str = s->strstart;
          n = s->lookahead - (MIN_MATCH-1);
@@ -708,9 +708,9 @@ index 1ec761448de9..aa0c9c67a6dc 100644
      Bytef *buf;
      unsigned size;
 @@ -1173,15 +1205,16 @@ local unsigned read_buf(strm, buf, size)
-
+ 
      strm->avail_in  -= len;
-
+ 
 -    zmemcpy(buf, strm->next_in, len);
 -    if (strm->state->wrap == 1) {
 -        strm->adler = adler32(strm->adler, buf, len);
@@ -721,7 +721,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 -    }
 +    if (strm->state->wrap == 2)
 +        copy_with_crc(strm, buf, len);
-+    else
++    else 
  #endif
 +    {
 +        zmemcpy(buf, strm->next_in, len);
@@ -730,7 +730,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 +    }
      strm->next_in  += len;
      strm->total_in += len;
-
+ 
 @@ -1479,7 +1512,19 @@ local void check_match(s, start, match, length)
   *    performed for at least two bytes (required for the zip translate_eol
   *    option -- not supported here).
@@ -759,7 +759,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 -            INSERT_STRING(s, s->strstart, hash_head);
 +            hash_head = insert_string(s, s->strstart);
          }
-
+ 
          /* Find the longest match, discarding those <= prev_length.
 @@ -1878,7 +1923,7 @@ local block_state deflate_fast(s, flush)
                  s->match_length--; /* string at strstart already in table */
@@ -777,7 +777,7 @@ index 1ec761448de9..aa0c9c67a6dc 100644
 -            INSERT_STRING(s, s->strstart, hash_head);
 +            hash_head = insert_string(s, s->strstart);
          }
-
+ 
          /* Find the longest match, discarding those <= prev_length.
 @@ -2001,7 +2046,7 @@ local block_state deflate_slow(s, flush)
              s->prev_length -= 2;
@@ -837,12 +837,12 @@ index 23ecdd312bc0..ab56df7663b6 100644
 -
 +    unsigned zalign(16) crc0[4 * 5];
                  /* used by deflate.c: */
-
+ 
      uInt  w_size;        /* LZ77 window size (32K by default) */
 @@ -346,4 +346,14 @@ void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf,
                flush = _tr_tally(s, distance, length)
  #endif
-
+ 
 +/* Functions that are SIMD optimised on x86 */
 +void ZLIB_INTERNAL crc_fold_init(deflate_state* const s);
 +void ZLIB_INTERNAL crc_fold_copy(deflate_state* const s,
@@ -1090,7 +1090,7 @@ index 000000000000..e56fe8b85a39
 + * Copyright (C) 2013 Intel Corporation. All rights reserved.
 + * Author:
 + *  Jim Kukunas
-+ *
++ * 
 + * For conditions of distribution and use, see copyright notice in zlib.h
 + */
 +
@@ -1204,7 +1204,7 @@ index 80375b8b6109..4425bcf75eb3 100644
 @@ -283,4 +283,10 @@ extern z_const char * const z_errmsg[10]; /* indexed by 2-zlib_error */
  #define ZSWAP32(q) ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
                      (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
-
+ 
 +#ifdef _MSC_VER
 +#define zalign(x) __declspec(align(x))
 +#else
diff --git a/deps/v8/third_party/zlib/patches/0003-uninitializedjump.patch b/deps/v8/third_party/zlib/patches/0003-uninitializedjump.patch
index 5208319f70..7aae3238a5 100644
--- a/deps/v8/third_party/zlib/patches/0003-uninitializedjump.patch
+++ b/deps/v8/third_party/zlib/patches/0003-uninitializedjump.patch
@@ -11,5 +11,5 @@ index a39e62787862..c6053fd1c7ea 100644
 +     */
 +    zmemzero(s->prev, s->w_size * sizeof(Pos));
      s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
-
+ 
      s->high_water = 0;      /* nothing written to s->window yet */
diff --git a/deps/v8/third_party/zlib/patches/0004-fix-uwp.patch b/deps/v8/third_party/zlib/patches/0004-fix-uwp.patch
new file mode 100644
index 0000000000..23145a7ae5
--- /dev/null
+++ b/deps/v8/third_party/zlib/patches/0004-fix-uwp.patch
@@ -0,0 +1,22 @@
+diff --git a/third_party/zlib/contrib/minizip/iowin32.c b/third_party/zlib/contrib/minizip/iowin32.c
+index 246ceb91a139..c6bc314b3c28 100644
+--- a/third_party/zlib/contrib/minizip/iowin32.c
++++ b/third_party/zlib/contrib/minizip/iowin32.c
+@@ -31,14 +31,12 @@
+ #define _WIN32_WINNT 0x601
+ #endif
+ 
+-#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+-// see Include/shared/winapifamily.h in the Windows Kit
+-#if defined(WINAPI_FAMILY_PARTITION) && (!(defined(IOWIN32_USING_WINRT_API)))
+-#if WINAPI_FAMILY_ONE_PARTITION(WINAPI_FAMILY, WINAPI_PARTITION_APP)
++#if !defined(IOWIN32_USING_WINRT_API)
++#if defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP)
++// Windows Store or Universal Windows Platform
+ #define IOWIN32_USING_WINRT_API 1
+ #endif
+ #endif
+-#endif
+ 
+ voidpf  ZCALLBACK win32_open_file_func  OF((voidpf opaque, const char* filename, int mode));
+ uLong   ZCALLBACK win32_read_file_func  OF((voidpf opaque, voidpf stream, void* buf, uLong size));
diff --git a/deps/v8/third_party/zlib/trees.h b/deps/v8/third_party/zlib/trees.h
index 45a749f0cc..d35639d82a 100644
--- a/deps/v8/third_party/zlib/trees.h
+++ b/deps/v8/third_party/zlib/trees.h
@@ -125,3 +125,4 @@ local const int base_dist[D_CODES] = {
    32,    48,    64,    96,   128,   192,   256,   384,   512,   768,
  1024,  1536,  2048,  3072,  4096,  6144,  8192, 12288, 16384, 24576
 };
+
diff --git a/deps/v8/tools/BUILD.gn b/deps/v8/tools/BUILD.gn
index 8d18f4df75..2f8197dd36 100644
--- a/deps/v8/tools/BUILD.gn
+++ b/deps/v8/tools/BUILD.gn
@@ -14,25 +14,23 @@ group("gn_all") {
     "gcmole:v8_run_gcmole",
     "jsfunfuzz:v8_jsfunfuzz",
   ]
+
+  if (is_win) {
+    data_deps += [ "v8windbg" ]
+  }
 }
 
 group("v8_check_static_initializers") {
-  data_deps = [
-    "..:d8",
-  ]
+  data_deps = [ "..:d8" ]
 
-  data = [
-    "check-static-initializers.sh",
-  ]
+  data = [ "check-static-initializers.sh" ]
 }
 
 group("v8_android_test_runner_deps") {
   testonly = true
 
   if (is_android && !build_with_chromium) {
-    data_deps = [
-      "//build/android:test_runner_py",
-    ]
+    data_deps = [ "//build/android:test_runner_py" ]
     data = [
       # This is used by android.py, but not included by test_runner_py above.
       "//third_party/catapult/devil/devil/android/perf/",
@@ -44,9 +42,9 @@ group("v8_testrunner") {
   testonly = true
 
   data_deps = [
-    "..:v8_python_base",
-    "..:v8_dump_build_config",
     ":v8_android_test_runner_deps",
+    "..:v8_dump_build_config",
+    "..:v8_python_base",
   ]
 
   data = [
diff --git a/deps/v8/tools/callstats.html b/deps/v8/tools/callstats.html
index a7580c9319..97a6638215 100644
--- a/deps/v8/tools/callstats.html
+++ b/deps/v8/tools/callstats.html
@@ -1101,13 +1101,13 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       var reader = new FileReader();
 
       reader.onload = function(evt) {
-        handleLoadText(this.result, append);
+        handleLoadText(this.result, append, file.name);
       }
       reader.readAsText(file);
     }
 
-    function handleLoadText(text, append) {
-      handleLoadJSON(JSON.parse(text), append);
+    function handleLoadText(text, append, fileName) {
+      handleLoadJSON(JSON.parse(text), append, fileName);
     }
 
     function getStateFromParams() {
@@ -1121,10 +1121,10 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       return result;
     }
 
-    function handleLoadJSON(json, append) {
+    function handleLoadJSON(json, append, fileName) {
       let isFirstLoad = pages === undefined;
       json = fixClusterTelemetryResults(json);
-      json = fixSinglePageJSON(json);
+      json = fixSinglePageJSON(json, fileName);
       if (append && !isFirstLoad) {
         json = createUniqueVersions(json)
       }
@@ -1144,7 +1144,7 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
     function fixClusterTelemetryResults(json) {
       // Convert CT results to callstats compatible JSON
       // Input:
-      // { PATH: { "pairs": { METRIC: { "count": XX, "time": XX }.. }}.. }
+      // { VERSION_NAME: { PAGE: { METRIC: { "count": {XX}, "duration": {XX} }.. }}.. }
       let firstEntry;
       for (let key in json) {
         firstEntry = json[key];
@@ -1171,19 +1171,28 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       return {__proto__:null, ClusterTelemetry: result};
     }
 
-    function fixSinglePageJSON(json) {
+    function fixSinglePageJSON(json, name) {
       // Try to detect the single-version case, where we're missing the toplevel
       // version object. The incoming JSON is of the form:
-      //    {"Page 1": [... data points ... ], "Page 2": [...], ...}
+        //   { PAGE: ... , PAGE_2:  }
       // Instead of the default multi-page JSON:
       //    {"Version 1": { "Page 1": ..., ...}, "Version 2": {...}, ...}
       // In this case insert a single "Default" version as top-level entry.
-      var firstProperty = (object) => {
-        for (var key in object) return key;
+      let firstProperty = (object) => {
+        for (let key in object) return object[key];
       };
-      var maybePage = json[firstProperty(json)];
-      if (!Array.isArray(maybePage)) return json;
-      return {"Default": json}
+      let maybePage = firstProperty(json);
+      let maybeMetrics = firstProperty(maybePage);
+      let tempName = name ? name : new Date().toISOString();
+      if ('count' in maybeMetrics && 'duration' in maybeMetrics) {
+        return {[tempName]: json}
+      }
+      // Legacy fallback where the metrics are encoded as arrays:
+      //  { PAGE: [[metric_name, ...], [...], ]}
+      if (Array.isArray(maybeMetrics)) {
+        return {[tempName]: json}
+      }
+      return json
     }
 
     var appendIndex = 0;
@@ -1603,9 +1612,19 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       }
     }
     PageVersion.fromJSON = function(version, name, data) {
-      var page = new PageVersion(version, pages.get(name));
-      for (var i = 0; i < data.length; i++) {
-        page.add(Entry.fromJSON(i, data[data.length - i - 1]));
+      let page = new PageVersion(version, pages.get(name));
+      // Distinguish between the legacy format which just uses Arrays,
+      // or the new object style.
+      if (Array.isArray(data)) {
+        for (let i = 0; i < data.length; i++) {
+          page.add(Entry.fromLegacyJSON(i, data[data.length - i - 1]));
+        }
+      } else {
+        let position = 0;
+        for (let metric_name in data) {
+          page.add(Entry.fromJSON(position, metric_name, data[metric_name]));
+          position++;
+        }
       }
       page.sort();
       return page
@@ -1698,9 +1717,15 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
         return this._timeVariancePercent
       }
     }
-    Entry.fromJSON = function(position, data) {
+    Entry.fromLegacyJSON = function(position, data) {
       return new Entry(position, ...data);
     }
+    Entry.fromJSON = function(position, name, data) {
+      let time = data.duration;
+      let count = data.count;
+      return new Entry(position, name, time.average, time.stddev, 
+                       count.average, count.stddev);
+    }
 
     class Group {
       constructor(name, regexp, color) {
diff --git a/deps/v8/tools/callstats.py b/deps/v8/tools/callstats.py
index 248970e81a..f756757a9a 100755
--- a/deps/v8/tools/callstats.py
+++ b/deps/v8/tools/callstats.py
@@ -32,8 +32,6 @@ import operator
 from callstats_groups import RUNTIME_CALL_STATS_GROUPS
 
 import numpy
-import scipy
-import scipy.stats
 from math import sqrt
 
 
@@ -328,6 +326,10 @@ def do_run_replay_server(args):
 # Calculate statistics.
 
 def statistics(data):
+  # NOTE(V8:10269): imports moved here to mitigate the outage.
+  import scipy
+  import scipy.stats
+
   N = len(data)
   average = numpy.average(data)
   median = numpy.median(data)
diff --git a/deps/v8/tools/clusterfuzz/BUILD.gn b/deps/v8/tools/clusterfuzz/BUILD.gn
index e0c4531555..d75e6f9687 100644
--- a/deps/v8/tools/clusterfuzz/BUILD.gn
+++ b/deps/v8/tools/clusterfuzz/BUILD.gn
@@ -11,8 +11,11 @@ if (v8_correctness_fuzzer) {
       "v8_foozzie.py",
       "v8_foozzie_harness_adjust.js",
       "v8_fuzz_config.py",
+      "v8_fuzz_experiments.json",
+      "v8_fuzz_flags.json",
       "v8_mock.js",
       "v8_mock_archs.js",
+      "v8_mock_webassembly.js",
       "v8_sanity_checks.js",
       "v8_suppressions.js",
       "v8_suppressions.py",
diff --git a/deps/v8/tools/clusterfuzz/testdata/failure_output.txt b/deps/v8/tools/clusterfuzz/testdata/failure_output.txt
index de3c15eab2..73db1cb0c3 100644
--- a/deps/v8/tools/clusterfuzz/testdata/failure_output.txt
+++ b/deps/v8/tools/clusterfuzz/testdata/failure_output.txt
@@ -9,9 +9,9 @@
 # Compared x64,ignition with x64,ignition_turbo
 #
 # Flags of x64,ignition:
---correctness-fuzzer-suppressions --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --turbo-filter=~ --noopt --liftoff --no-wasm-tier-up --flag1 --flag2=0
+--correctness-fuzzer-suppressions --expose-gc --allow-natives-for-differential-fuzzing --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --turbo-filter=~ --noopt --liftoff --no-wasm-tier-up --flag1 --flag2=0
 # Flags of x64,ignition_turbo:
---correctness-fuzzer-suppressions --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --flag3
+--correctness-fuzzer-suppressions --expose-gc --allow-natives-for-differential-fuzzing --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --flag3
 #
 # Difference:
 - unknown
diff --git a/deps/v8/tools/clusterfuzz/testdata/sanity_check_output.txt b/deps/v8/tools/clusterfuzz/testdata/sanity_check_output.txt
index 1443c61f2b..3c105ef1b4 100644
--- a/deps/v8/tools/clusterfuzz/testdata/sanity_check_output.txt
+++ b/deps/v8/tools/clusterfuzz/testdata/sanity_check_output.txt
@@ -9,9 +9,9 @@
 # Compared x64,ignition with x64,ignition_turbo
 #
 # Flags of x64,ignition:
---correctness-fuzzer-suppressions --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --turbo-filter=~ --noopt --liftoff --no-wasm-tier-up
+--correctness-fuzzer-suppressions --expose-gc --allow-natives-for-differential-fuzzing --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345 --turbo-filter=~ --noopt --liftoff --no-wasm-tier-up
 # Flags of x64,ignition_turbo:
---correctness-fuzzer-suppressions --expose-gc --allow-natives-syntax --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345
+--correctness-fuzzer-suppressions --expose-gc --allow-natives-for-differential-fuzzing --invoke-weak-callbacks --omit-quit --es-staging --wasm-staging --no-wasm-async-compilation --suppress-asm-messages --random-seed 12345
 #
 # Difference:
 - unknown
diff --git a/deps/v8/tools/clusterfuzz/v8_commands.py b/deps/v8/tools/clusterfuzz/v8_commands.py
index e35ae1a871..e84cd915e3 100644
--- a/deps/v8/tools/clusterfuzz/v8_commands.py
+++ b/deps/v8/tools/clusterfuzz/v8_commands.py
@@ -12,11 +12,13 @@ from threading import Event, Timer
 
 import v8_fuzz_config
 
+PYTHON3 = sys.version_info >= (3, 0)
+
 # List of default flags passed to each d8 run.
 DEFAULT_FLAGS = [
   '--correctness-fuzzer-suppressions',
   '--expose-gc',
-  '--allow-natives-syntax',
+  '--allow-natives-for-differential-fuzzing',
   '--invoke-weak-callbacks',
   '--omit-quit',
   '--es-staging',
@@ -28,23 +30,29 @@ DEFAULT_FLAGS = [
 BASE_PATH = os.path.dirname(os.path.abspath(__file__))
 
 # List of files passed to each d8 run before the testcase.
-DEFAULT_FILES = [
-  os.path.join(BASE_PATH, 'v8_mock.js'),
-  os.path.join(BASE_PATH, 'v8_suppressions.js'),
-]
+DEFAULT_MOCK = os.path.join(BASE_PATH, 'v8_mock.js')
+
+# Suppressions on JavaScript level for known issues.
+JS_SUPPRESSIONS = os.path.join(BASE_PATH, 'v8_suppressions.js')
 
-# Architecture-specific mock file
+# Config-specific mock files.
 ARCH_MOCKS = os.path.join(BASE_PATH, 'v8_mock_archs.js')
+WEBASSEMBLY_MOCKS = os.path.join(BASE_PATH, 'v8_mock_webassembly.js')
 
 # Timeout in seconds for one d8 run.
 TIMEOUT = 3
 
 
 def _startup_files(options):
-  """Default files and optional architecture-specific mock file."""
-  files = DEFAULT_FILES[:]
+  """Default files and optional config-specific mock files."""
+  files = [DEFAULT_MOCK]
+  if not options.skip_suppressions:
+    files.append(JS_SUPPRESSIONS)
   if options.first.arch != options.second.arch:
     files.append(ARCH_MOCKS)
+  # Mock out WebAssembly when comparing with jitless mode.
+  if '--jitless' in options.first.flags + options.second.flags:
+    files.append(WEBASSEMBLY_MOCKS)
   return files
 
 
@@ -101,12 +109,16 @@ class Output(object):
 
 def Execute(args, cwd, timeout=None):
   popen_args = [c for c in args if c != ""]
+  kwargs = {}
+  if PYTHON3:
+    kwargs['encoding'] = 'utf-8'
   try:
     process = subprocess.Popen(
       args=popen_args,
       stdout=subprocess.PIPE,
-      stderr=subprocess.STDOUT,
-      cwd=cwd
+      stderr=subprocess.PIPE,
+      cwd=cwd,
+      **kwargs
     )
   except Exception as e:
     sys.stderr.write("Error executing: %s\n" % popen_args)
@@ -129,6 +141,6 @@ def Execute(args, cwd, timeout=None):
   return Output(
       process.returncode,
       timeout_event.is_set(),
-      stdout.decode('utf-8', 'replace').encode('utf-8'),
+      stdout,
       process.pid,
   )
diff --git a/deps/v8/tools/clusterfuzz/v8_foozzie.py b/deps/v8/tools/clusterfuzz/v8_foozzie.py
index bf3d568cd6..b6638cc377 100755
--- a/deps/v8/tools/clusterfuzz/v8_foozzie.py
+++ b/deps/v8/tools/clusterfuzz/v8_foozzie.py
@@ -25,6 +25,8 @@ from collections import namedtuple
 import v8_commands
 import v8_suppressions
 
+PYTHON3 = sys.version_info >= (3, 0)
+
 CONFIGS = dict(
   default=[],
   ignition=[
@@ -60,13 +62,11 @@ CONFIGS = dict(
   ignition_turbo_opt=[
     '--always-opt',
     '--no-liftoff',
-    '--no-lazy-feedback-allocation'
   ],
   ignition_turbo_opt_eager=[
     '--always-opt',
     '--no-lazy',
     '--no-lazy-inner-functions',
-    '--no-lazy-feedback-allocation',
   ],
   jitless=[
     '--jitless',
@@ -77,7 +77,6 @@ CONFIGS = dict(
   slow_path_opt=[
     '--always-opt',
     '--force-slow-path',
-    '--no-lazy-feedback-allocation',
   ],
   trusted=[
     '--no-untrusted-code-mitigations',
@@ -85,7 +84,6 @@ CONFIGS = dict(
   trusted_opt=[
     '--always-opt',
     '--no-untrusted-code-mitigations',
-    '--no-lazy-feedback-allocation',
   ],
 )
 
@@ -212,6 +210,9 @@ def parse_args():
   parser.add_argument(
       '--skip-sanity-checks', default=False, action='store_true',
       help='skip sanity checks for testing purposes')
+  parser.add_argument(
+      '--skip-suppressions', default=False, action='store_true',
+      help='skip suppressions to reproduce known issues')
 
   # Add arguments for each run configuration.
   first_config_arguments.add_arguments(parser, 'ignition')
@@ -256,16 +257,13 @@ def content_bailout(content, ignore_fun):
   return False
 
 
-def pass_bailout(output, step_number):
-  """Print info and return if in timeout or crash pass states."""
+def timeout_bailout(output, step_number):
+  """Print info and return if in timeout pass state."""
   if output.HasTimedOut():
     # Dashed output, so that no other clusterfuzz tools can match the
     # words timeout or crash.
     print('# V8 correctness - T-I-M-E-O-U-T %d' % step_number)
     return True
-  if output.HasCrashed():
-    print('# V8 correctness - C-R-A-S-H %d' % step_number)
-    return True
   return False
 
 
@@ -287,7 +285,15 @@ def print_difference(
   first_config_label = '%s,%s' % (options.first.arch, options.first.config)
   second_config_label = '%s,%s' % (options.second.arch, options.second.config)
   source_file_text = SOURCE_FILE_TEMPLATE % source if source else ''
-  print((FAILURE_TEMPLATE % dict(
+
+  if PYTHON3:
+    first_stdout = first_config_output.stdout
+    second_stdout = second_config_output.stdout
+  else:
+    first_stdout = first_config_output.stdout.decode('utf-8', 'replace')
+    second_stdout = second_config_output.stdout.decode('utf-8', 'replace')
+
+  text = (FAILURE_TEMPLATE % dict(
       configs='%s:%s' % (first_config_label, second_config_label),
       source_file_text=source_file_text,
       source_key=source_key,
@@ -296,13 +302,15 @@ def print_difference(
       second_config_label=second_config_label,
       first_config_flags=' '.join(first_command.flags),
       second_config_flags=' '.join(second_command.flags),
-      first_config_output=
-          first_config_output.stdout.decode('utf-8', 'replace'),
-      second_config_output=
-          second_config_output.stdout.decode('utf-8', 'replace'),
+      first_config_output=first_stdout,
+      second_config_output=second_stdout,
       source=source,
-      difference=difference.decode('utf-8', 'replace'),
-  )).encode('utf-8', 'replace'))
+      difference=difference,
+  ))
+  if PYTHON3:
+    print(text)
+  else:
+    print(text.encode('utf-8', 'replace'))
 
 
 def main():
@@ -312,10 +320,14 @@ def main():
   suppress = v8_suppressions.get_suppression(
       options.first.arch, options.first.config,
       options.second.arch, options.second.config,
+      options.skip_suppressions,
   )
 
   # Static bailout based on test case content or metadata.
-  with open(options.testcase) as f:
+  kwargs = {}
+  if PYTHON3:
+    kwargs['encoding'] = 'utf-8'
+  with open(options.testcase, 'r', **kwargs) as f:
     content = f.read()
   if content_bailout(get_meta_data(content), suppress.ignore_by_metadata):
     return RETURN_FAIL
@@ -332,8 +344,7 @@ def main():
   if not options.skip_sanity_checks:
     first_config_output = first_cmd.run(SANITY_CHECKS)
     second_config_output = second_cmd.run(SANITY_CHECKS)
-    difference, _ = suppress.diff(
-        first_config_output.stdout, second_config_output.stdout)
+    difference, _ = suppress.diff(first_config_output, second_config_output)
     if difference:
       # Special source key for sanity checks so that clusterfuzz dedupes all
       # cases on this in case it's hit.
@@ -345,21 +356,21 @@ def main():
 
   first_config_output = first_cmd.run(options.testcase, verbose=True)
 
-  # Early bailout based on first run's output.
-  if pass_bailout(first_config_output, 1):
+  # Early bailout if first run was a timeout.
+  if timeout_bailout(first_config_output, 1):
     return RETURN_PASS
 
   second_config_output = second_cmd.run(options.testcase, verbose=True)
 
-  # Bailout based on second run's output.
-  if pass_bailout(second_config_output, 2):
+  # Bailout if second run was a timeout.
+  if timeout_bailout(second_config_output, 2):
     return RETURN_PASS
 
-  difference, source = suppress.diff(
-      first_config_output.stdout, second_config_output.stdout)
+  difference, source = suppress.diff(first_config_output, second_config_output)
 
   if source:
-    source_key = hashlib.sha1(source).hexdigest()[:ORIGINAL_SOURCE_HASH_LENGTH]
+    long_key = hashlib.sha1(source.encode('utf-8')).hexdigest()
+    source_key = long_key[:ORIGINAL_SOURCE_HASH_LENGTH]
   else:
     source_key = ORIGINAL_SOURCE_DEFAULT
 
@@ -377,11 +388,18 @@ def main():
         first_config_output, second_config_output, difference, source)
     return RETURN_FAIL
 
-  # TODO(machenbach): Figure out if we could also return a bug in case there's
-  # no difference, but one of the line suppressions has matched - and without
-  # the match there would be a difference.
+  # Show if a crash has happened in one of the runs and no difference was
+  # detected.
+  if first_config_output.HasCrashed():
+    print('# V8 correctness - C-R-A-S-H 1')
+  elif second_config_output.HasCrashed():
+    print('# V8 correctness - C-R-A-S-H 2')
+  else:
+    # TODO(machenbach): Figure out if we could also return a bug in case
+    # there's no difference, but one of the line suppressions has matched -
+    # and without the match there would be a difference.
+    print('# V8 correctness - pass')
 
-  print('# V8 correctness - pass')
   return RETURN_PASS
 
 
diff --git a/deps/v8/tools/clusterfuzz/v8_foozzie_test.py b/deps/v8/tools/clusterfuzz/v8_foozzie_test.py
index 6fb3345bc3..f82afc9e20 100755
--- a/deps/v8/tools/clusterfuzz/v8_foozzie_test.py
+++ b/deps/v8/tools/clusterfuzz/v8_foozzie_test.py
@@ -9,60 +9,113 @@ import subprocess
 import sys
 import unittest
 
+import v8_commands
 import v8_foozzie
 import v8_fuzz_config
 import v8_suppressions
 
+try:
+  basestring
+except NameError:
+  basestring = str
+
+PYTHON3 = sys.version_info >= (3, 0)
+
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 FOOZZIE = os.path.join(BASE_DIR, 'v8_foozzie.py')
 TEST_DATA = os.path.join(BASE_DIR, 'testdata')
 
+KNOWN_BUILDS = [
+  'd8',
+  'clang_x86/d8',
+  'clang_x86_v8_arm/d8',
+  'clang_x64_v8_arm64/d8',
+  'clang_x64_pointer_compression/d8',
+]
+
 
 class ConfigTest(unittest.TestCase):
   def testExperiments(self):
-    """Test that probabilities add up to 100 and that all config names exist.
-    """
-    EXPERIMENTS = v8_fuzz_config.FOOZZIE_EXPERIMENTS
+    """Test integrity of probabilities and configs."""
     CONFIGS = v8_foozzie.CONFIGS
+    EXPERIMENTS = v8_fuzz_config.FOOZZIE_EXPERIMENTS
+    FLAGS = v8_fuzz_config.ADDITIONAL_FLAGS
+    # Probabilities add up to 100%.
+    first_is_int = lambda x: type(x[0]) == int
+    assert all(map(first_is_int, EXPERIMENTS))
     assert sum(x[0] for x in EXPERIMENTS) == 100
+    # Configs used in experiments are defined.
     assert all(map(lambda x: x[1] in CONFIGS, EXPERIMENTS))
     assert all(map(lambda x: x[2] in CONFIGS, EXPERIMENTS))
-    assert all(map(lambda x: x[3].endswith('d8'), EXPERIMENTS))
+    # The last config item points to a known build configuration.
+    assert all(map(lambda x: x[3] in KNOWN_BUILDS, EXPERIMENTS))
+    # Ensure we compare different configs and same d8, or same config
+    # to different d8.
+    is_sane_comparison = lambda x: (x[1] == x[2]) == ('d8' != x[3])
+    assert all(map(is_sane_comparison, EXPERIMENTS))
+    # All flags have a probability.
+    first_is_float = lambda x: type(x[0]) == float
+    assert all(map(first_is_float, FLAGS))
+    first_between_0_and_1 = lambda x: x[0] > 0 and x[0] < 1
+    assert all(map(first_between_0_and_1, FLAGS))
+    # Test consistent flags.
+    second_is_string = lambda x: isinstance(x[1], basestring)
+    assert all(map(second_is_string, FLAGS))
+    # We allow spaces to separate more flags. We don't allow spaces in the flag
+    # value.
+    is_flag = lambda x: x.startswith('--')
+    all_parts_are_flags = lambda x: all(map(is_flag, x[1].split()))
+    assert all(map(all_parts_are_flags, FLAGS))
 
   def testConfig(self):
-    """Smoke test how to choose experiments.
-
-    When experiment distribution changes this test might change, too.
-    """
+    """Smoke test how to choose experiments."""
+    config = v8_fuzz_config.Config('foo', random.Random(42))
+    experiments = [
+      [25, 'ignition', 'jitless', 'd8'],
+      [75, 'ignition', 'ignition', 'clang_x86/d8'],
+    ]
+    flags = [
+      [0.1, '--flag'],
+      [0.3, '--baz'],
+      [0.3, '--foo --bar'],
+    ]
     self.assertEqual(
         [
           '--first-config=ignition',
-          '--second-config=ignition_turbo_opt',
+          '--second-config=jitless',
           '--second-d8=d8',
-          '--second-config-extra-flags=--stress-scavenge=100',
-          '--second-config-extra-flags=--no-regexp-tier-up',
-          '--second-config-extra-flags=--no-enable-ssse3',
-          '--second-config-extra-flags=--no-enable-bmi2',
-          '--second-config-extra-flags=--no-enable-lzcnt',
+          '--second-config-extra-flags=--baz',
+          '--second-config-extra-flags=--foo',
+          '--second-config-extra-flags=--bar',
         ],
-        v8_fuzz_config.Config('foo', random.Random(42)).choose_foozzie_flags(),
+        config.choose_foozzie_flags(experiments, flags),
+    )
+    self.assertEqual(
+        [
+          '--first-config=ignition',
+          '--second-config=jitless',
+          '--second-d8=d8',
+        ],
+        config.choose_foozzie_flags(experiments, flags),
     )
 
 
 class UnitTest(unittest.TestCase):
   def testDiff(self):
-    # TODO(machenbach): Mock out suppression configuration.
-    suppress = v8_suppressions.get_suppression(
-        'x64', 'ignition', 'x64', 'ignition_turbo')
+    def diff_fun(one, two, skip=False):
+      suppress = v8_suppressions.get_suppression(
+          'x64', 'ignition', 'x64', 'ignition_turbo', skip)
+      return suppress.diff_lines(one.splitlines(), two.splitlines())
+
     one = ''
     two = ''
     diff = None, None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
 
     one = 'a \n  b\nc();'
     two = 'a \n  b\nc();'
     diff = None, None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
 
     # Ignore line before caret, caret position and error message.
     one = """
@@ -80,7 +133,7 @@ somefile.js: TypeError: baz is not a function
   undefined
 """
     diff = None, None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
 
     one = """
 Still equal
@@ -90,7 +143,7 @@ Extra line
 Still equal
 """
     diff = '- Extra line', None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
 
     one = """
 Still equal
@@ -100,7 +153,7 @@ Still equal
 Extra line
 """
     diff = '+ Extra line', None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
 
     one = """
 undefined
@@ -112,7 +165,61 @@ otherfile.js: TypeError: undefined is not a constructor
 """
     diff = """- somefile.js: TypeError: undefined is not a constructor
 + otherfile.js: TypeError: undefined is not a constructor""", None
-    self.assertEquals(diff, suppress.diff(one, two))
+    self.assertEqual(diff, diff_fun(one, two))
+
+    # Test that skipping suppressions works.
+    one = """
+v8-foozzie source: foo
+23:TypeError: bar is not a function
+"""
+    two = """
+v8-foozzie source: foo
+42:TypeError: baz is not a function
+"""
+    self.assertEqual((None, 'foo'), diff_fun(one, two))
+    diff = """- 23:TypeError: bar is not a function
++ 42:TypeError: baz is not a function""", 'foo'
+    self.assertEqual(diff, diff_fun(one, two, skip=True))
+
+  def testOutputCapping(self):
+    def output(stdout, is_crash):
+      exit_code = -1 if is_crash else 0
+      return v8_commands.Output(
+          exit_code=exit_code, timed_out=False, stdout=stdout, pid=0)
+
+    def check(stdout1, stdout2, is_crash1, is_crash2, capped_lines1,
+              capped_lines2):
+      output1 = output(stdout1, is_crash1)
+      output2 = output(stdout2, is_crash2)
+      self.assertEqual(
+          (capped_lines1, capped_lines2),
+          v8_suppressions.get_output_capped(output1, output2))
+
+    # No capping, already equal.
+    check('1\n2', '1\n2', True, True, '1\n2', '1\n2')
+    # No crash, no capping.
+    check('1\n2', '1\n2\n3', False, False, '1\n2', '1\n2\n3')
+    check('1\n2\n3', '1\n2', False, False, '1\n2\n3', '1\n2')
+    # Cap smallest if all runs crash.
+    check('1\n2', '1\n2\n3', True, True, '1\n2', '1\n2')
+    check('1\n2\n3', '1\n2', True, True, '1\n2', '1\n2')
+    check('1\n2', '1\n23', True, True, '1\n2', '1\n2')
+    check('1\n23', '1\n2', True, True, '1\n2', '1\n2')
+    # Cap the non-crashy run.
+    check('1\n2\n3', '1\n2', False, True, '1\n2', '1\n2')
+    check('1\n2', '1\n2\n3', True, False, '1\n2', '1\n2')
+    check('1\n23', '1\n2', False, True, '1\n2', '1\n2')
+    check('1\n2', '1\n23', True, False, '1\n2', '1\n2')
+    # The crashy run has more output.
+    check('1\n2\n3', '1\n2', True, False, '1\n2\n3', '1\n2')
+    check('1\n2', '1\n2\n3', False, True, '1\n2', '1\n2\n3')
+    check('1\n23', '1\n2', True, False, '1\n23', '1\n2')
+    check('1\n2', '1\n23', False, True, '1\n2', '1\n23')
+    # Keep output difference when capping.
+    check('1\n2', '3\n4\n5', True, True, '1\n2', '3\n4')
+    check('1\n2\n3', '4\n5', True, True, '1\n2', '4\n5')
+    check('12', '345', True, True, '12', '34')
+    check('123', '45', True, True, '12', '45')
 
 
 def cut_verbose_output(stdout):
@@ -120,17 +227,22 @@ def cut_verbose_output(stdout):
   return '\n'.join(stdout.split('\n')[4:])
 
 
-def run_foozzie(second_d8_dir, *extra_flags):
+def run_foozzie(second_d8_dir, *extra_flags, **kwargs):
+  second_config = 'ignition_turbo'
+  if 'second_config' in kwargs:
+    second_config = 'jitless'
+  kwargs = {}
+  if PYTHON3:
+    kwargs['text'] = True
   return subprocess.check_output([
     sys.executable, FOOZZIE,
     '--random-seed', '12345',
     '--first-d8', os.path.join(TEST_DATA, 'baseline', 'd8.py'),
     '--second-d8', os.path.join(TEST_DATA, second_d8_dir, 'd8.py'),
     '--first-config', 'ignition',
-    '--second-config', 'ignition_turbo',
+    '--second-config', second_config,
     os.path.join(TEST_DATA, 'fuzz-123.js'),
-  ] + list(extra_flags))
-
+  ] + list(extra_flags), **kwargs)
 
 class SystemTest(unittest.TestCase):
   """This tests the whole correctness-fuzzing harness with fake build
@@ -146,7 +258,12 @@ class SystemTest(unittest.TestCase):
   """
   def testSyntaxErrorDiffPass(self):
     stdout = run_foozzie('build1', '--skip-sanity-checks')
-    self.assertEquals('# V8 correctness - pass\n', cut_verbose_output(stdout))
+    self.assertEqual('# V8 correctness - pass\n', cut_verbose_output(stdout))
+    # Default comparison includes suppressions.
+    self.assertIn('v8_suppressions.js', stdout)
+    # Default comparison doesn't include any specific mock files.
+    self.assertNotIn('v8_mock_archs.js', stdout)
+    self.assertNotIn('v8_mock_webassembly.js', stdout)
 
   def testDifferentOutputFail(self):
     with open(os.path.join(TEST_DATA, 'failure_output.txt')) as f:
@@ -157,8 +274,8 @@ class SystemTest(unittest.TestCase):
                   '--first-config-extra-flags=--flag2=0',
                   '--second-config-extra-flags=--flag3')
     e = ctx.exception
-    self.assertEquals(v8_foozzie.RETURN_FAIL, e.returncode)
-    self.assertEquals(expected_output, cut_verbose_output(e.output))
+    self.assertEqual(v8_foozzie.RETURN_FAIL, e.returncode)
+    self.assertEqual(expected_output, cut_verbose_output(e.output))
 
   def testSanityCheck(self):
     with open(os.path.join(TEST_DATA, 'sanity_check_output.txt')) as f:
@@ -166,8 +283,8 @@ class SystemTest(unittest.TestCase):
     with self.assertRaises(subprocess.CalledProcessError) as ctx:
       run_foozzie('build2')
     e = ctx.exception
-    self.assertEquals(v8_foozzie.RETURN_FAIL, e.returncode)
-    self.assertEquals(expected_output, e.output)
+    self.assertEqual(v8_foozzie.RETURN_FAIL, e.returncode)
+    self.assertEqual(expected_output, e.output)
 
   def testDifferentArch(self):
     """Test that the architecture-specific mocks are passed to both runs when
@@ -181,6 +298,34 @@ class SystemTest(unittest.TestCase):
     self.assertIn('v8_mock_archs.js', lines[1])
     self.assertIn('v8_mock_archs.js', lines[3])
 
+  def testJitless(self):
+    """Test that webassembly is mocked out when comparing with jitless."""
+    stdout = run_foozzie(
+        'build1', '--skip-sanity-checks', second_config='jitless')
+    lines = stdout.split('\n')
+    # TODO(machenbach): Don't depend on the command-lines being printed in
+    # particular lines.
+    self.assertIn('v8_mock_webassembly.js', lines[1])
+    self.assertIn('v8_mock_webassembly.js', lines[3])
+
+  def testSkipSuppressions(self):
+    """Test that the suppressions file is not passed when skipping
+    suppressions.
+    """
+    # Compare baseline with baseline. This passes as there is no difference.
+    stdout = run_foozzie(
+        'baseline', '--skip-sanity-checks', '--skip-suppressions')
+    self.assertNotIn('v8_suppressions.js', stdout)
+
+    # Compare with a build that usually suppresses a difference. Now we fail
+    # since we skip suppressions.
+    with self.assertRaises(subprocess.CalledProcessError) as ctx:
+      run_foozzie(
+          'build1', '--skip-sanity-checks', '--skip-suppressions')
+    e = ctx.exception
+    self.assertEqual(v8_foozzie.RETURN_FAIL, e.returncode)
+    self.assertNotIn('v8_suppressions.js', e.output)
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/deps/v8/tools/clusterfuzz/v8_fuzz_config.py b/deps/v8/tools/clusterfuzz/v8_fuzz_config.py
index cc68a7dd4c..99439a9d66 100644
--- a/deps/v8/tools/clusterfuzz/v8_fuzz_config.py
+++ b/deps/v8/tools/clusterfuzz/v8_fuzz_config.py
@@ -2,62 +2,23 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import json
+import os
 import random
 
+THIS_DIR = os.path.dirname(os.path.abspath(__file__))
+
 # List of configuration experiments for correctness fuzzing.
 # List of <probability>, <1st config name>, <2nd config name>, <2nd d8>.
 # Probabilities must add up to 100.
-FOOZZIE_EXPERIMENTS = [
-  [10, 'ignition', 'jitless', 'd8'],
-  [10, 'ignition', 'slow_path', 'd8'],
-  [5, 'ignition', 'slow_path_opt', 'd8'],
-  [25, 'ignition', 'ignition_turbo', 'd8'],
-  [2, 'ignition_no_ic', 'ignition_turbo', 'd8'],
-  [2, 'ignition', 'ignition_turbo_no_ic', 'd8'],
-  [15, 'ignition', 'ignition_turbo_opt', 'd8'],
-  [2, 'ignition_no_ic', 'ignition_turbo_opt', 'd8'],
-  [4, 'ignition_turbo_opt', 'ignition_turbo_opt', 'clang_x64_pointer_compression/d8'],
-  [5, 'ignition_turbo', 'ignition_turbo', 'clang_x64_pointer_compression/d8'],
-  [4, 'ignition_turbo_opt', 'ignition_turbo_opt', 'clang_x86/d8'],
-  [4, 'ignition_turbo', 'ignition_turbo', 'clang_x86/d8'],
-  [4, 'ignition', 'ignition', 'clang_x86/d8'],
-  [4, 'ignition', 'ignition', 'clang_x64_v8_arm64/d8'],
-  [4, 'ignition', 'ignition', 'clang_x86_v8_arm/d8'],
-]
+with open(os.path.join(THIS_DIR, 'v8_fuzz_experiments.json')) as f:
+  FOOZZIE_EXPERIMENTS = json.load(f)
 
 # Additional flag experiments. List of tuples like
 # (<likelihood to use flags in [0,1)>, <flag>).
-ADDITIONAL_FLAGS = [
-  (0.1, '--stress-marking=100'),
-  (0.1, '--stress-scavenge=100'),
-  (0.1, '--stress-compaction-random'),
-  (0.1, '--random-gc-interval=2000'),
-  (0.2, '--noanalyze-environment-liveness'),
-  (0.1, '--stress-delay-tasks'),
-  (0.01, '--thread-pool-size=1'),
-  (0.01, '--thread-pool-size=2'),
-  (0.01, '--thread-pool-size=4'),
-  (0.01, '--thread-pool-size=8'),
-  (0.1, '--interrupt-budget=1000'),
-  (0.25, '--future'),
-  (0.2, '--no-regexp-tier-up'),
-  (0.1, '--regexp-interpret-all'),
-  (0.1, '--regexp-tier-up-ticks=10'),
-  (0.1, '--regexp-tier-up-ticks=100'),
-  (0.1, '--turbo-instruction-scheduling'),
-  (0.1, '--turbo-stress-instruction-scheduling'),
-  (0.1, '--no-enable-sse3'),
-  (0.1, '--no-enable-ssse3'),
-  (0.1, '--no-enable-sse4_1'),
-  (0.1, '--no-enable-sse4_2'),
-  (0.1, '--no-enable-sahf'),
-  (0.1, '--no-enable-avx'),
-  (0.1, '--no-enable-fma3'),
-  (0.1, '--no-enable-bmi1'),
-  (0.1, '--no-enable-bmi2'),
-  (0.1, '--no-enable-lzcnt'),
-  (0.1, '--no-enable-popcnt'),
-]
+with open(os.path.join(THIS_DIR, 'v8_fuzz_flags.json')) as f:
+  ADDITIONAL_FLAGS = json.load(f)
+
 
 class Config(object):
   def __init__(self, name, rng=None):
@@ -70,22 +31,29 @@ class Config(object):
     self.name = name
     self.rng = rng or random.Random()
 
-  def choose_foozzie_flags(self):
+  def choose_foozzie_flags(self, foozzie_experiments=None, additional_flags=None):
     """Randomly chooses a configuration from FOOZZIE_EXPERIMENTS.
 
+    Args:
+      foozzie_experiments: Override experiment config for testing.
+      additional_flags: Override additional flags for testing.
+
     Returns: List of flags to pass to v8_foozzie.py fuzz harness.
     """
+    foozzie_experiments = foozzie_experiments or FOOZZIE_EXPERIMENTS
+    additional_flags = additional_flags or ADDITIONAL_FLAGS
 
     # Add additional flags to second config based on experiment percentages.
     extra_flags = []
-    for p, flag in ADDITIONAL_FLAGS:
+    for p, flags in additional_flags:
       if self.rng.random() < p:
-        extra_flags.append('--second-config-extra-flags=%s' % flag)
+        for flag in flags.split():
+          extra_flags.append('--second-config-extra-flags=%s' % flag)
 
     # Calculate flags determining the experiment.
     acc = 0
     threshold = self.rng.random() * 100
-    for prob, first_config, second_config, second_d8 in FOOZZIE_EXPERIMENTS:
+    for prob, first_config, second_config, second_d8 in foozzie_experiments:
       acc += prob
       if acc > threshold:
         return [
diff --git a/deps/v8/tools/clusterfuzz/v8_fuzz_experiments.json b/deps/v8/tools/clusterfuzz/v8_fuzz_experiments.json
new file mode 100644
index 0000000000..e8a6f7a8da
--- /dev/null
+++ b/deps/v8/tools/clusterfuzz/v8_fuzz_experiments.json
@@ -0,0 +1,17 @@
+[
+  [10, "ignition", "jitless", "d8"],
+  [10, "ignition", "slow_path", "d8"],
+  [5, "ignition", "slow_path_opt", "d8"],
+  [25, "ignition", "ignition_turbo", "d8"],
+  [2, "ignition_no_ic", "ignition_turbo", "d8"],
+  [2, "ignition", "ignition_turbo_no_ic", "d8"],
+  [15, "ignition", "ignition_turbo_opt", "d8"],
+  [5, "ignition_no_ic", "ignition_turbo_opt", "d8"],
+  [3, "ignition_turbo_opt", "ignition_turbo_opt", "clang_x64_pointer_compression/d8"],
+  [3, "ignition_turbo", "ignition_turbo", "clang_x64_pointer_compression/d8"],
+  [4, "ignition", "ignition", "clang_x86/d8"],
+  [4, "ignition_turbo", "ignition_turbo", "clang_x86/d8"],
+  [4, "ignition_turbo_opt", "ignition_turbo_opt", "clang_x86/d8"],
+  [4, "ignition_turbo", "ignition_turbo", "clang_x64_v8_arm64/d8"],
+  [4, "ignition_turbo", "ignition_turbo", "clang_x86_v8_arm/d8"]
+]
\ No newline at end of file
diff --git a/deps/v8/tools/clusterfuzz/v8_fuzz_flags.json b/deps/v8/tools/clusterfuzz/v8_fuzz_flags.json
new file mode 100644
index 0000000000..832a7c35b9
--- /dev/null
+++ b/deps/v8/tools/clusterfuzz/v8_fuzz_flags.json
@@ -0,0 +1,34 @@
+[
+  [0.1, "--stress-marking=100"],
+  [0.1, "--stress-scavenge=100"],
+  [0.1, "--stress-compaction-random"],
+  [0.1, "--random-gc-interval=2000"],
+  [0.2, "--noanalyze-environment-liveness"],
+  [0.1, "--stress-delay-tasks"],
+  [0.01, "--thread-pool-size=1"],
+  [0.01, "--thread-pool-size=2"],
+  [0.01, "--thread-pool-size=4"],
+  [0.01, "--thread-pool-size=8"],
+  [0.1, "--interrupt-budget=1000"],
+  [0.25, "--future"],
+  [0.2, "--no-regexp-tier-up"],
+  [0.1, "--regexp-interpret-all"],
+  [0.1, "--regexp-tier-up-ticks=10"],
+  [0.1, "--regexp-tier-up-ticks=100"],
+  [0.1, "--turbo-instruction-scheduling"],
+  [0.1, "--turbo-stress-instruction-scheduling"],
+  [0.1, "--no-enable-sse3"],
+  [0.1, "--no-enable-ssse3"],
+  [0.1, "--no-enable-sse4_1"],
+  [0.1, "--no-enable-sse4_2"],
+  [0.1, "--no-enable-sahf"],
+  [0.1, "--no-enable-avx"],
+  [0.1, "--no-enable-fma3"],
+  [0.1, "--no-enable-bmi1"],
+  [0.1, "--no-enable-bmi2"],
+  [0.1, "--no-enable-lzcnt"],
+  [0.1, "--no-enable-popcnt"],
+  [0.25, "--no-lazy-feedback-allocation"],
+  [0.1, "--no-lazy-feedback-allocation --interrupt-budget=100"],
+  [0.05, "--budget-for-feedback-vector-allocation=0"]
+]
\ No newline at end of file
diff --git a/deps/v8/tools/clusterfuzz/v8_mock.js b/deps/v8/tools/clusterfuzz/v8_mock.js
index b805ccf772..618e14c784 100644
--- a/deps/v8/tools/clusterfuzz/v8_mock.js
+++ b/deps/v8/tools/clusterfuzz/v8_mock.js
@@ -13,8 +13,8 @@
 var prettyPrinted = function prettyPrinted(msg) { return msg; };
 
 // Mock Math.random.
-(function () {
-  var index = 0
+(function() {
+  let index = 0
   Math.random = function() {
     index = (index + 1) % 10;
     return index / 10.0;
@@ -22,55 +22,47 @@ var prettyPrinted = function prettyPrinted(msg) { return msg; };
 })();
 
 // Mock Date.
-(function () {
-  var index = 0
-  var mockDate = 1477662728696
-  var mockDateNow = function() {
-    index = (index + 1) % 10
-    mockDate = mockDate + index + 1
-    return mockDate
+(function() {
+  let index = 0;
+  let mockDate = 1477662728696;
+  const mockDateNow = function() {
+    index = (index + 1) % 10;
+    mockDate = mockDate + index + 1;
+    return mockDate;
   }
 
-  var origDate = Date;
-  var constructDate = function(args) {
-    if (args.length == 1) {
-      var result = new origDate(args[0]);
-    } else if (args.length == 2) {
-      var result = new origDate(args[0], args[1]);
-    } else if (args.length == 3) {
-      var result = new origDate(args[0], args[1], args[2]);
-    } else if (args.length == 4) {
-      var result = new origDate(args[0], args[1], args[2], args[3]);
-    } else if (args.length == 5) {
-      var result = new origDate(args[0], args[1], args[2], args[3], args[4]);
-    } else if (args.length == 6) {
-      var result = new origDate(
-          args[0], args[1], args[2], args[3], args[4], args[5]);
-    } else if (args.length >= 7) {
-      var result = new origDate(
-          args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
+  const origDate = Date;
+  const construct = Reflect.construct;
+  const constructDate = function(args) {
+    let result;
+    if (args.length) {
+      result = construct(origDate, args);
     } else {
-      var result = new origDate(mockDateNow());
+      result = new origDate(mockDateNow());
     }
     result.constructor = function(...args) { return constructDate(args); }
     Object.defineProperty(
         result, "constructor", { configurable: false, writable: false });
-    return result
+    return result;
   }
 
+  origDate.prototype.constructor = function(...args) {
+    return constructDate(args);
+  };
+
   var handler = {
-    apply: function (target, thisArg, args) {
-      return constructDate(args)
+    apply: function(target, thisArg, args) {
+      return constructDate(args);
     },
-    construct: function (target, args, newTarget) {
-      return constructDate(args)
+    construct: function(target, args, newTarget) {
+      return constructDate(args);
     },
     get: function(target, property, receiver) {
       if (property == "now") {
         return mockDateNow;
       }
       if (property == "prototype") {
-        return origDate.prototype
+        return origDate.prototype;
       }
     },
   }
@@ -79,37 +71,65 @@ var prettyPrinted = function prettyPrinted(msg) { return msg; };
 })();
 
 // Mock performance methods.
-performance.now = function () { return 1.2; }
-performance.measureMemory = function () { return []; }
+performance.now = function() { return 1.2; };
+performance.measureMemory = function() { return []; };
 
 // Mock readline so that test cases don't hang.
-readline = function () { return "foo"; }
+readline = function() { return "foo"; };
 
 // Mock stack traces.
-Error.prepareStackTrace = function (error, structuredStackTrace) {
+Error.prepareStackTrace = function(error, structuredStackTrace) {
   return "";
 };
 Object.defineProperty(
     Error, 'prepareStackTrace', { configurable: false, writable: false });
 
 // Mock buffer access in float typed arrays because of varying NaN patterns.
-// Note, for now we just use noop forwarding proxies, because they already
-// turn off optimizations.
-(function () {
-  var mock = function(arrayType) {
-    var handler = {
+(function() {
+  const origIsNaN = isNaN;
+  const deNaNify = function(value) { return origIsNaN(value) ? 1 : value; };
+  const mock = function(type) {
+
+    // Remove NaN values from parameters to "set" function.
+    const set = type.prototype.set;
+    type.prototype.set = function(array, offset) {
+      if (Array.isArray(array)) {
+        array = array.map(deNaNify);
+      }
+      set.apply(this, [array, offset]);
+    };
+
+    const handler = {
+      // Remove NaN values from parameters to constructor.
       construct: function(target, args) {
-        var obj = new (Function.prototype.bind.apply(arrayType, [null].concat(args)));
+        for (let i = 0; i < args.length; i++) {
+          if (args[i] != null &&
+              typeof args[i][Symbol.iterator] === 'function') {
+            // Consume iterators.
+            args[i] = Array.from(args[i]);
+          }
+          if (Array.isArray(args[i])) {
+            args[i] = args[i].map(deNaNify);
+          }
+        }
+
+        const obj = new (
+            Function.prototype.bind.call(type, null, ...args));
         return new Proxy(obj, {
           get: function(x, prop) {
             if (typeof x[prop] == "function")
-              return x[prop].bind(obj)
+              return x[prop].bind(obj);
             return x[prop];
           },
+          // Remove NaN values that get assigned.
+          set: function(target, prop, value, receiver) {
+            target[prop] = deNaNify(value);
+            return value;
+          }
         });
       },
     };
-    return new Proxy(arrayType, handler);
+    return new Proxy(type, handler);
   }
 
   Float32Array = mock(Float32Array);
@@ -117,11 +137,11 @@ Object.defineProperty(
 })();
 
 // Mock Worker.
-(function () {
-  var index = 0;
+(function() {
+  let index = 0;
   // TODO(machenbach): Randomize this for each test case, but keep stable
   // during comparison. Also data and random above.
-  var workerMessages = [
+  const workerMessages = [
     undefined, 0, -1, "", "foo", 42, [], {}, [0], {"x": 0}
   ];
   Worker = function(code){
diff --git a/deps/v8/tools/clusterfuzz/v8_mock_archs.js b/deps/v8/tools/clusterfuzz/v8_mock_archs.js
index 33883775f5..3482e8c4c6 100644
--- a/deps/v8/tools/clusterfuzz/v8_mock_archs.js
+++ b/deps/v8/tools/clusterfuzz/v8_mock_archs.js
@@ -10,23 +10,40 @@
 // This file is loaded before each correctness test cases and won't get
 // minimized.
 
-// Mock maximum typed-array length and limit to 1MiB.
-(function () {
+// Mock maximum typed-array buffer and limit to 1MiB. Otherwise we might
+// get range errors. We ignore those by crashing, but that reduces coverage,
+// hence, let's reduce the range-error rate.
+(function() {
   // Math.min might be manipulated in test cases.
-  let min = Math.min;
-  let mock = function(arrayType) {
-    let handler = {
+  const min = Math.min;
+  const maxBytes = 1048576;
+  const mock = function(type) {
+    const maxLength = maxBytes / (type.BYTES_PER_ELEMENT || 1);
+    const handler = {
       construct: function(target, args) {
-        for (let i = 0; i < args.length; i++) {
-          if (typeof args[i] != "object") {
-            args[i] = min(1048576, args[i]);
+        if (args[0] && typeof args[0] != "object") {
+          // Length used as first argument.
+          args[0] = min(maxLength, Number(args[0]));
+        } else if (args[0] instanceof ArrayBuffer && args.length > 1) {
+          // Buffer used as first argument.
+          const buffer = args[0];
+          args[1] = Number(args[1]);
+          // Ensure offset is multiple of bytes per element.
+          args[1] = args[1] - (args[1] % type.BYTES_PER_ELEMENT);
+          // Limit offset to length of buffer.
+          args[1] = min(args[1], buffer.byteLength || 0);
+          if (args.length > 2) {
+            // If also length is given, limit it to the maximum that's possible
+            // given buffer and offset.
+            const maxBytesLeft = buffer.byteLength - args[1];
+            const maxLengthLeft = maxBytesLeft / type.BYTES_PER_ELEMENT;
+            args[2] = min(Number(args[2]), maxLengthLeft);
           }
         }
-        return new (
-            Function.prototype.bind.apply(arrayType, [null].concat(args)));
+        return new (Function.prototype.bind.apply(type, [null].concat(args)));
       },
     };
-    return new Proxy(arrayType, handler);
+    return new Proxy(type, handler);
   }
 
   ArrayBuffer = mock(ArrayBuffer);
@@ -44,9 +61,11 @@
   Float64Array = mock(Float64Array);
 })();
 
-// Mock typed array set function and limit maximum offset to 1MiB.
-(function () {
-  let typedArrayTypes = [
+// Mock typed array set function and cap offset to not throw a range error.
+(function() {
+  // Math.min might be manipulated in test cases.
+  const min = Math.min;
+  const types = [
     Int8Array,
     Uint8Array,
     Uint8ClampedArray,
@@ -59,10 +78,14 @@
     Float32Array,
     Float64Array,
   ];
-  for (let typedArrayType of typedArrayTypes) {
-    let set = typedArrayType.prototype.set
-    typedArrayType.prototype.set = function(array, offset) {
-      set.apply(this, [array, offset > 1048576 ? 1048576 : offset])
+  for (const type of types) {
+    const set = type.prototype.set;
+    type.prototype.set = function(array, offset) {
+      if (Array.isArray(array)) {
+        offset = Number(offset);
+        offset = min(offset, this.length - array.length);
+      }
+      set.call(this, array, offset);
     };
   }
 })();
diff --git a/deps/v8/tools/clusterfuzz/v8_mock_webassembly.js b/deps/v8/tools/clusterfuzz/v8_mock_webassembly.js
new file mode 100644
index 0000000000..594e6e7004
--- /dev/null
+++ b/deps/v8/tools/clusterfuzz/v8_mock_webassembly.js
@@ -0,0 +1,18 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This mocks out the WebAssembly object with a permissive dummy.
+
+(function() {
+  const handler = {
+    get: function(x, prop) {
+      if (prop == Symbol.toPrimitive) {
+        return function() { return undefined; };
+      }
+      return dummy;
+    },
+  };
+  const dummy = new Proxy(function() { return dummy; }, handler);
+  WebAssembly = dummy;
+})();
diff --git a/deps/v8/tools/clusterfuzz/v8_suppressions.js b/deps/v8/tools/clusterfuzz/v8_suppressions.js
index 011e7272ba..d73ce04d45 100644
--- a/deps/v8/tools/clusterfuzz/v8_suppressions.js
+++ b/deps/v8/tools/clusterfuzz/v8_suppressions.js
@@ -6,28 +6,3 @@
 // You can temporarily change JS behavior here to silence known problems.
 // Please refer to a bug in a comment and remove the suppression once the
 // problem is fixed.
-
-// Suppress http://crbug.com/662429
-(function () {
-  var oldMathPow = Math.pow
-  Math.pow = function(a, b){
-    if (b < 0) {
-      return 0.000017;
-    } else {
-      return oldMathPow(a, b);
-    }
-  }
-})();
-
-// Suppress http://crbug.com/693426
-(function () {
-  var oldMathPow = Math.pow
-  Math.pow = function(a, b){
-    var s = "" + oldMathPow(a, b)
-    // Low tech precision mock. Limit digits in string representation.
-    // The phrases Infinity and NaN don't match the split("e").
-    s = s.split("e");
-    s[0] = s[0].substr(0, 17);
-    return parseFloat(s.join("e"));
-  }
-})();
diff --git a/deps/v8/tools/clusterfuzz/v8_suppressions.py b/deps/v8/tools/clusterfuzz/v8_suppressions.py
index f1aaa6448a..a3fa351f68 100644
--- a/deps/v8/tools/clusterfuzz/v8_suppressions.py
+++ b/deps/v8/tools/clusterfuzz/v8_suppressions.py
@@ -27,6 +27,13 @@ to silence a particular class of problems.
 import itertools
 import re
 
+try:
+  # Python 3
+  from itertools import zip_longest
+except ImportError:
+  # Python 2
+  from itertools import izip_longest as zip_longest
+
 # Max line length for regular experessions checking for lines to ignore.
 MAX_LINE_LENGTH = 512
 
@@ -37,32 +44,6 @@ CARET_RE = re.compile(r'^\s*\^\s*$')
 # V8, e.g. '/v8/test/mjsunit/d8-performance-now.js' including /v8/. A test will
 # be suppressed if one of the files below was used to mutate the test.
 IGNORE_SOURCES = {
-  # This contains a usage of f.arguments that often fires.
-  'crbug.com/662424': [
-    '/v8/test/mjsunit/bugs/bug-222.js',
-    '/v8/test/mjsunit/bugs/bug-941049.js',
-    '/v8/test/mjsunit/regress/regress-crbug-668795.js',
-    '/v8/test/mjsunit/regress/regress-1079.js',
-    '/v8/test/mjsunit/regress/regress-2989.js',
-  ],
-
-  'crbug.com/688159': [
-    '/v8/test/mjsunit/es7/exponentiation-operator.js',
-  ],
-
-  # TODO(machenbach): Implement blacklisting files for particular configs only,
-  # here ignition_eager.
-  'crbug.com/691589': [
-    '/v8/test/mjsunit/regress/regress-1200351.js',
-  ],
-
-  'crbug.com/691587': [
-    '/v8/test/mjsunit/asm/regress-674089.js',
-  ],
-
-  'crbug.com/774805': [
-    '/v8/test/mjsunit/console.js',
-  ],
 }
 
 # Ignore by test case pattern. Map from config->bug->regexp. Config '' is used
@@ -81,10 +62,6 @@ IGNORE_TEST_CASES = {
 # Regular expressions are assumed to be compiled. We use regexp.search.
 IGNORE_OUTPUT = {
   '': {
-    'crbug.com/664068':
-        re.compile(r'RangeError(?!: byte length)', re.S),
-    'crbug.com/667678':
-        re.compile(r'\[native code\]', re.S),
     'crbug.com/689877':
         re.compile(r'^.*SyntaxError: .*Stack overflow$', re.M),
   },
@@ -116,9 +93,6 @@ ALLOWED_LINE_DIFFS = [
 
   # crbug.com/680064. This subsumes one of the above expressions.
   r'^(.*)TypeError: .* function$',
-
-  # crbug.com/664068
-  r'^(.*)(?:Array buffer allocation failed|Invalid array buffer length)(.*)$',
 ]
 
 # Lines matching any of the following regular expressions will be ignored.
@@ -142,8 +116,33 @@ IGNORE_LINES = [re.compile(exp) for exp in IGNORE_LINES]
 
 ORIGINAL_SOURCE_PREFIX = 'v8-foozzie source: '
 
+
+def get_output_capped(output1, output2):
+  """Returns a pair of stdout strings.
+
+  The strings are safely capped if at least one run has crashed.
+  """
+
+  # No length difference or no crash -> no capping.
+  if (len(output1.stdout) == len(output2.stdout) or
+      (not output1.HasCrashed() and not output2.HasCrashed())):
+    return output1.stdout, output2.stdout
+
+  # Both runs have crashed, cap by the shorter output.
+  if output1.HasCrashed() and output2.HasCrashed():
+    cap = min(len(output1.stdout), len(output2.stdout))
+  # Only the first run has crashed, cap by its output length.
+  elif output1.HasCrashed():
+    cap = len(output1.stdout)
+  # Similar if only the second run has crashed.
+  else:
+    cap = len(output2.stdout)
+
+  return output1.stdout[0:cap], output2.stdout[0:cap]
+
+
 def line_pairs(lines):
-  return itertools.izip_longest(
+  return zip_longest(
       lines, itertools.islice(lines, 1, None), fillvalue=None)
 
 
@@ -191,14 +190,14 @@ def diff_output(output1, output2, allowed, ignore1, ignore2):
       return all(not e.match(line) for e in ignore)
     return fun
 
-  lines1 = filter(useful_line(ignore1), output1)
-  lines2 = filter(useful_line(ignore2), output2)
+  lines1 = list(filter(useful_line(ignore1), output1))
+  lines2 = list(filter(useful_line(ignore2), output2))
 
   # This keeps track where we are in the original source file of the fuzz
   # test case.
   source = None
 
-  for ((line1, lookahead1), (line2, lookahead2)) in itertools.izip_longest(
+  for ((line1, lookahead1), (line2, lookahead2)) in zip_longest(
       line_pairs(lines1), line_pairs(lines2), fillvalue=(None, None)):
 
     # Only one of the two iterators should run out.
@@ -237,8 +236,8 @@ def diff_output(output1, output2, allowed, ignore1, ignore2):
   return None, source
 
 
-def get_suppression(arch1, config1, arch2, config2):
-  return V8Suppression(arch1, config1, arch2, config2)
+def get_suppression(arch1, config1, arch2, config2, skip=False):
+  return V8Suppression(arch1, config1, arch2, config2, skip)
 
 
 class Suppression(object):
@@ -259,17 +258,30 @@ class Suppression(object):
 
 
 class V8Suppression(Suppression):
-  def __init__(self, arch1, config1, arch2, config2):
+  def __init__(self, arch1, config1, arch2, config2, skip):
     self.arch1 = arch1
     self.config1 = config1
     self.arch2 = arch2
     self.config2 = config2
+    if skip:
+      self.allowed_line_diffs = []
+      self.ignore_output = {}
+      self.ignore_sources = {}
+    else:
+      self.allowed_line_diffs = ALLOWED_LINE_DIFFS
+      self.ignore_output = IGNORE_OUTPUT
+      self.ignore_sources = IGNORE_SOURCES
 
   def diff(self, output1, output2):
+    # Diff capped lines in the presence of crashes.
+    return self.diff_lines(
+        *map(str.splitlines, get_output_capped(output1, output2)))
+
+  def diff_lines(self, output1_lines, output2_lines):
     return diff_output(
-        output1.splitlines(),
-        output2.splitlines(),
-        ALLOWED_LINE_DIFFS,
+        output1_lines,
+        output2_lines,
+        self.allowed_line_diffs,
         IGNORE_LINES,
         IGNORE_LINES,
     )
@@ -286,13 +298,13 @@ class V8Suppression(Suppression):
       # already minimized test cases might have dropped the delimiter line.
       content = testcase
     for key in ['', self.arch1, self.arch2, self.config1, self.config2]:
-      for bug, exp in IGNORE_TEST_CASES.get(key, {}).iteritems():
+      for bug, exp in IGNORE_TEST_CASES.get(key, {}).items():
         if exp.search(content):
           return bug
     return None
 
   def ignore_by_metadata(self, metadata):
-    for bug, sources in IGNORE_SOURCES.iteritems():
+    for bug, sources in self.ignore_sources.items():
       for source in sources:
         if source in metadata['sources']:
           return bug
@@ -306,12 +318,12 @@ class V8Suppression(Suppression):
 
   def ignore_by_output(self, output, arch, config):
     def check(mapping):
-      for bug, exp in mapping.iteritems():
+      for bug, exp in mapping.items():
         if exp.search(output):
           return bug
       return None
     for key in ['', arch, config]:
-      bug = check(IGNORE_OUTPUT.get(key, {}))
+      bug = check(self.ignore_output.get(key, {}))
       if bug:
         return bug
     return None
diff --git a/deps/v8/tools/codemap.js b/deps/v8/tools/codemap.js
index df6770f9a8..71e3e6a5d8 100644
--- a/deps/v8/tools/codemap.js
+++ b/deps/v8/tools/codemap.js
@@ -140,7 +140,7 @@ CodeMap.prototype.addStaticCode = function(
 CodeMap.prototype.markPages_ = function(start, end) {
   for (var addr = start; addr <= end;
        addr += CodeMap.PAGE_SIZE) {
-    this.pages_[addr >>> CodeMap.PAGE_ALIGNMENT] = 1;
+    this.pages_[(addr / CodeMap.PAGE_SIZE)|0] = 1;
   }
 };
 
@@ -187,7 +187,7 @@ CodeMap.prototype.findInTree_ = function(tree, addr) {
  * @param {number} addr Address.
  */
 CodeMap.prototype.findAddress = function(addr) {
-  var pageAddr = addr >>> CodeMap.PAGE_ALIGNMENT;
+  var pageAddr = (addr / CodeMap.PAGE_SIZE)|0;
   if (pageAddr in this.pages_) {
     // Static code entries can contain "holes" of unnamed code.
     // In this case, the whole library is assigned to this address.
diff --git a/deps/v8/tools/debug_helper/BUILD.gn b/deps/v8/tools/debug_helper/BUILD.gn
index 10b94a5295..b151e12918 100644
--- a/deps/v8/tools/debug_helper/BUILD.gn
+++ b/deps/v8/tools/debug_helper/BUILD.gn
@@ -32,15 +32,11 @@ action("run_mkgrokdump") {
   testonly = true
   visibility = [ ":*" ]
 
-  deps = [
-    "../../test/mkgrokdump:mkgrokdump($v8_generator_toolchain)",
-  ]
+  deps = [ "../../test/mkgrokdump:mkgrokdump($v8_generator_toolchain)" ]
 
   script = "../run.py"
 
-  outputs = [
-    "$target_gen_dir/v8heapconst.py",
-  ]
+  outputs = [ "$target_gen_dir/v8heapconst.py" ]
 
   args = [
     "./" + rebase_path(
@@ -56,13 +52,9 @@ action("run_mkgrokdump") {
 action("gen_heap_constants") {
   testonly = true
   visibility = [ ":*" ]
-  deps = [
-    ":run_mkgrokdump",
-  ]
+  deps = [ ":run_mkgrokdump" ]
   script = "gen-heap-constants.py"
-  outputs = [
-    "$target_gen_dir/heap-constants-gen.cc",
-  ]
+  outputs = [ "$target_gen_dir/heap-constants-gen.cc" ]
   args = [
     rebase_path(target_gen_dir, root_build_dir),
     rebase_path("$target_gen_dir/heap-constants-gen.cc", root_build_dir),
@@ -72,13 +64,12 @@ action("gen_heap_constants") {
 v8_component("v8_debug_helper") {
   testonly = true
 
-  public = [
-    "debug-helper.h",
-  ]
+  public = [ "debug-helper.h" ]
 
   sources = [
     "$target_gen_dir/../../torque-generated/class-debug-readers-tq.cc",
     "$target_gen_dir/../../torque-generated/class-debug-readers-tq.h",
+    "$target_gen_dir/../../torque-generated/instance-types-tq.h",
     "$target_gen_dir/heap-constants-gen.cc",
     "debug-helper-internal.cc",
     "debug-helper-internal.h",
@@ -91,6 +82,7 @@ v8_component("v8_debug_helper") {
 
   deps = [
     ":gen_heap_constants",
+    "../..:generate_bytecode_builtins_list",
     "../..:run_torque",
     "../..:v8_headers",
     "../..:v8_libbase",
diff --git a/deps/v8/tools/debug_helper/debug-helper-internal.cc b/deps/v8/tools/debug_helper/debug-helper-internal.cc
index 597ea7a639..c64d0ad58c 100644
--- a/deps/v8/tools/debug_helper/debug-helper-internal.cc
+++ b/deps/v8/tools/debug_helper/debug-helper-internal.cc
@@ -8,7 +8,9 @@
 
 namespace i = v8::internal;
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 
 bool IsPointerCompressed(uintptr_t address) {
 #if COMPRESS_POINTERS_BOOL
@@ -58,4 +60,6 @@ bool TqObject::IsSuperclassOf(const TqObject* other) const {
   return GetName() != other->GetName();
 }
 
-}  // namespace v8_debug_helper_internal
+}  // namespace debug_helper_internal
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/tools/debug_helper/debug-helper-internal.h b/deps/v8/tools/debug_helper/debug-helper-internal.h
index 9c498cd5d6..c9812b7635 100644
--- a/deps/v8/tools/debug_helper/debug-helper-internal.h
+++ b/deps/v8/tools/debug_helper/debug-helper-internal.h
@@ -19,7 +19,9 @@
 
 namespace d = v8::debug_helper;
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 
 // A value that was read from the debuggee's memory.
 template <typename TValue>
@@ -119,7 +121,7 @@ class ObjectProperty : public PropertyBase {
 class ObjectPropertiesResult;
 struct ObjectPropertiesResultExtended : public d::ObjectPropertiesResult {
   // Back reference for cleanup.
-  v8_debug_helper_internal::ObjectPropertiesResult* base;
+  debug_helper_internal::ObjectPropertiesResult* base;
 };
 
 // Internal version of API class v8::debug_helper::ObjectPropertiesResult.
@@ -189,6 +191,14 @@ class TqObject {
   uintptr_t address_;
 };
 
+// A helpful template so that generated code can be sure that a string type name
+// actually resolves to a type, by repeating the name as the template parameter
+// and the value.
+template <typename T>
+const char* CheckTypeName(const char* name) {
+  return name;
+}
+
 // In ptr-compr builds, returns whether the address looks like a compressed
 // pointer (zero-extended from 32 bits). Otherwise returns false because no
 // pointers can be compressed.
@@ -207,6 +217,8 @@ d::PropertyKind GetArrayKind(d::MemoryAccessResult mem_result);
 // Torque class definitions.
 extern const d::ClassList kObjectClassList;
 
-}  // namespace v8_debug_helper_internal
+}  // namespace debug_helper_internal
+}  // namespace internal
+}  // namespace v8
 
 #endif
diff --git a/deps/v8/tools/debug_helper/debug-helper.h b/deps/v8/tools/debug_helper/debug-helper.h
index cbdd6ff881..df850e81ed 100644
--- a/deps/v8/tools/debug_helper/debug-helper.h
+++ b/deps/v8/tools/debug_helper/debug-helper.h
@@ -71,7 +71,12 @@ struct PropertyBase {
 
   // Statically-determined type, such as from .tq definition. Can be an empty
   // string if this property is itself a Torque-defined struct; in that case use
-  // |struct_fields| instead.
+  // |struct_fields| instead. This type should be treated as if it were used in
+  // the v8::internal namespace; that is, type "X::Y" can mean any of the
+  // following, in order of decreasing preference:
+  // - v8::internal::X::Y
+  // - v8::X::Y
+  // - X::Y
   const char* type;
 
   // In some cases, |type| may be a simple type representing a compressed
diff --git a/deps/v8/tools/debug_helper/gen-heap-constants.py b/deps/v8/tools/debug_helper/gen-heap-constants.py
index 1d81f2e510..6eb7f3743c 100644
--- a/deps/v8/tools/debug_helper/gen-heap-constants.py
+++ b/deps/v8/tools/debug_helper/gen-heap-constants.py
@@ -19,7 +19,9 @@ out = """
 #include "src/common/ptr-compr-inl.h"
 #include "tools/debug_helper/debug-helper-internal.h"
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 """
 
 def iterate_objects(target_space, camel_space_name):
@@ -70,7 +72,7 @@ if (hasattr(v8heapconst, 'HEAP_FIRST_PAGES')):  # Only exists in ptr-compr build
       out = out + '  }\n'
 out = out + '}\n'
 
-out = out + '\n}\n'
+out = out + '\n}\n}\n}\n'
 
 try:
   with open(sys.argv[2], "r") as out_file:
diff --git a/deps/v8/tools/debug_helper/get-object-properties.cc b/deps/v8/tools/debug_helper/get-object-properties.cc
index f3bd4811f2..9146dd4633 100644
--- a/deps/v8/tools/debug_helper/get-object-properties.cc
+++ b/deps/v8/tools/debug_helper/get-object-properties.cc
@@ -14,7 +14,9 @@
 
 namespace i = v8::internal;
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 
 constexpr char kObject[] = "v8::internal::Object";
 constexpr char kTaggedValue[] = "v8::internal::TaggedValue";
@@ -104,6 +106,7 @@ TypedObject GetTypedObjectByInstanceType(uintptr_t address,
   case i::INSTANCE_TYPE:                             \
     return {type_source, std::make_unique<Tq##ClassName>(address)};
     TORQUE_INSTANCE_CHECKERS_SINGLE_FULLY_DEFINED(INSTANCE_TYPE_CASE)
+    TORQUE_INSTANCE_CHECKERS_MULTIPLE_FULLY_DEFINED(INSTANCE_TYPE_CASE)
 #undef INSTANCE_TYPE_CASE
 
     default:
@@ -590,9 +593,11 @@ std::unique_ptr<ObjectPropertiesResult> GetObjectProperties(
                                                   stream.str(), kSmi);
 }
 
-}  // namespace v8_debug_helper_internal
+}  // namespace debug_helper_internal
+}  // namespace internal
+}  // namespace v8
 
-namespace di = v8_debug_helper_internal;
+namespace di = v8::internal::debug_helper_internal;
 
 extern "C" {
 V8_DEBUG_HELPER_EXPORT d::ObjectPropertiesResult*
diff --git a/deps/v8/tools/debug_helper/heap-constants.cc b/deps/v8/tools/debug_helper/heap-constants.cc
index edb47c80b1..f62dd9b697 100644
--- a/deps/v8/tools/debug_helper/heap-constants.cc
+++ b/deps/v8/tools/debug_helper/heap-constants.cc
@@ -7,7 +7,9 @@
 
 namespace d = v8::debug_helper;
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 
 std::string FindKnownObject(uintptr_t address,
                             const d::HeapAddresses& heap_addresses) {
@@ -82,4 +84,6 @@ KnownInstanceType FindKnownMapInstanceTypes(
   return result;
 }
 
-}  // namespace v8_debug_helper_internal
+}  // namespace debug_helper_internal
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/tools/debug_helper/heap-constants.h b/deps/v8/tools/debug_helper/heap-constants.h
index fb2d20df12..89620479ec 100644
--- a/deps/v8/tools/debug_helper/heap-constants.h
+++ b/deps/v8/tools/debug_helper/heap-constants.h
@@ -14,7 +14,9 @@
 
 namespace d = v8::debug_helper;
 
-namespace v8_debug_helper_internal {
+namespace v8 {
+namespace internal {
+namespace debug_helper_internal {
 
 // ===== Functions generated by gen-heap-constants.py: =========================
 
@@ -62,6 +64,8 @@ struct KnownInstanceType {
 KnownInstanceType FindKnownMapInstanceTypes(
     uintptr_t address, const d::HeapAddresses& heap_addresses);
 
-}  // namespace v8_debug_helper_internal
+}  // namespace debug_helper_internal
+}  // namespace internal
+}  // namespace v8
 
 #endif
diff --git a/deps/v8/tools/debug_helper/list-object-classes.cc b/deps/v8/tools/debug_helper/list-object-classes.cc
index 6285aeb2f5..2d723e9218 100644
--- a/deps/v8/tools/debug_helper/list-object-classes.cc
+++ b/deps/v8/tools/debug_helper/list-object-classes.cc
@@ -5,7 +5,7 @@
 #include "debug-helper-internal.h"
 #include "torque-generated/class-debug-readers-tq.h"
 
-namespace di = v8_debug_helper_internal;
+namespace di = v8::internal::debug_helper_internal;
 
 extern "C" {
 V8_DEBUG_HELPER_EXPORT const d::ClassList*
diff --git a/deps/v8/tools/dev/gm.py b/deps/v8/tools/dev/gm.py
index 67118368b4..9d5cbf056a 100755
--- a/deps/v8/tools/dev/gm.py
+++ b/deps/v8/tools/dev/gm.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 # Copyright 2017 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -18,6 +18,9 @@ All arguments are optional. Most combinations should work, e.g.:
     gm.py x64 mjsunit/foo cctest/test-bar/*
 """
 # See HELP below for additional documentation.
+# Note on Python3 compatibility: gm.py itself is Python3 compatible, but
+# run-tests.py, which will be executed by the same binary, is not; hence
+# the hashbang line at the top of this file explicitly requires Python2.
 
 from __future__ import print_function
 import errno
@@ -174,7 +177,7 @@ def _CallWithOutput(cmd):
   try:
     while True:
       try:
-        data = os.read(master, 512)
+        data = os.read(master, 512).decode('utf-8')
       except OSError as e:
         if e.errno != errno.EIO: raise
         break # EIO means EOF on some systems
diff --git a/deps/v8/tools/gdb-v8-support.py b/deps/v8/tools/gdb-v8-support.py
index f8442bf462..23c6c17cc1 100644
--- a/deps/v8/tools/gdb-v8-support.py
+++ b/deps/v8/tools/gdb-v8-support.py
@@ -209,14 +209,15 @@ GDB_EXTERNAL_EDITOR environment variable.
     super(Redirect, self).__init__("redirect", gdb.COMMAND_USER)
 
   def invoke(self, subcommand, from_tty):
-    old_stdout = gdb.execute("p dup(1)", to_string=True).split("=")[-1].strip()
+    old_stdout = gdb.execute(
+            "p (int)dup(1)", to_string=True).split("=")[-1].strip()
     try:
       time_suffix = time.strftime("%Y%m%d-%H%M%S")
       fd, file = tempfile.mkstemp(suffix="-%s.gdbout" % time_suffix)
       try:
         # Temporaily redirect stdout to the created tmp file for the
         # duration of the subcommand.
-        gdb.execute('p dup2(open("%s", 1), 1)' % file, to_string=True)
+        gdb.execute('p (int)dup2(open("%s", 1), 1)' % file, to_string=True)
         # Execute subcommand non interactively.
         result = gdb.execute(subcommand, from_tty=False, to_string=True)
         # Write returned string results to the temporary file as well.
@@ -231,11 +232,11 @@ GDB_EXTERNAL_EDITOR environment variable.
           print("Open output:\n  %s '%s'" % (os.environ['EDITOR'], file))
       finally:
         # Restore original stdout.
-        gdb.execute("p dup2(%s, 1)" % old_stdout, to_string=True)
+        gdb.execute("p (int)dup2(%s, 1)" % old_stdout, to_string=True)
         # Close the temporary file.
         os.close(fd)
     finally:
       # Close the originally duplicated stdout descriptor.
-      gdb.execute("p close(%s)" % old_stdout, to_string=True)
+      gdb.execute("p (int)close(%s)" % old_stdout, to_string=True)
 
 Redirect()
diff --git a/deps/v8/tools/gen-postmortem-metadata.py b/deps/v8/tools/gen-postmortem-metadata.py
index 1fddfcf83d..b36cd20221 100644
--- a/deps/v8/tools/gen-postmortem-metadata.py
+++ b/deps/v8/tools/gen-postmortem-metadata.py
@@ -263,7 +263,6 @@ extras_accessors = [
     'ExternalString, resource, Object, kResourceOffset',
     'SeqOneByteString, chars, char, kHeaderSize',
     'SeqTwoByteString, chars, char, kHeaderSize',
-    'UncompiledData, inferred_name, String, kInferredNameOffset',
     'UncompiledData, start_position, int32_t, kStartPositionOffset',
     'UncompiledData, end_position, int32_t, kEndPositionOffset',
     'SharedFunctionInfo, raw_function_token_offset, int16_t, kFunctionTokenOffsetOffset',
diff --git a/deps/v8/tools/generate-runtime-call-stats.py b/deps/v8/tools/generate-runtime-call-stats.py
index 2f9ba17871..ba10b799a1 100755
--- a/deps/v8/tools/generate-runtime-call-stats.py
+++ b/deps/v8/tools/generate-runtime-call-stats.py
@@ -9,6 +9,7 @@
 import argparse
 import csv
 import json
+import glob
 import os
 import pathlib
 import re
@@ -18,11 +19,12 @@ import statistics
 import subprocess
 import sys
 import tempfile
-import gzip
 
 from callstats_groups import RUNTIME_CALL_STATS_GROUPS
 
 
+JSON_FILE_EXTENSION=".pb_converted.json"
+
 def parse_args():
   parser = argparse.ArgumentParser(
       description="Run story and collect runtime call stats.")
@@ -375,23 +377,19 @@ def collect_buckets(story, group=True, repeats=1, output_dir="."):
     story_dir = f"{story.replace(':', '_')}_{i + 1}"
     trace_dir = os.path.join(output_dir, "artifacts", story_dir, "trace",
                              "traceEvents")
-    trace_file = os.path.join(trace_dir, "results.json")
-
-    # this script always unzips the json file and stores the output in
-    # results.json so just re-use that if it already exists, otherwise unzip the
-    # one file found in the traceEvents directory.
-    if not os.path.isfile(trace_file):
-      trace_files = os.listdir(trace_dir)
-      if len(trace_files) != 1:
-        print("Expecting just one file but got: %s" % trace_files)
-        sys.exit(1)
 
-      gz_trace_file = os.path.join(trace_dir, trace_files[0])
-      trace_file = os.path.join(trace_dir, "results.json")
+    # run_benchmark now dumps two files: a .pb.gz file and a .pb_converted.json
+    # file. We only need the latter.
+    trace_file_glob = os.path.join(trace_dir, "*" + JSON_FILE_EXTENSION)
+    trace_files = glob.glob(trace_file_glob)
+    if not trace_files:
+      print("Could not find *%s file in %s" % (JSON_FILE_EXTENSION, trace_dir))
+      sys.exit(1)
+    if len(trace_files) > 1:
+      print("Expecting one file but got: %s" % trace_files)
+      sys.exit(1)
 
-      with gzip.open(gz_trace_file, "rb") as f_in:
-        with open(trace_file, "wb") as f_out:
-          shutil.copyfileobj(f_in, f_out)
+    trace_file = trace_files[0]
 
     output = process_trace(trace_file)
     for name in output:
@@ -474,12 +472,12 @@ def main():
     if retain == "none":
       shutil.rmtree(output_dir)
     elif retain == "json":
-      # Delete all files bottom up except .json.gz files and attempt to delete
-      # subdirectories (ignoring errors).
+      # Delete all files bottom up except ones ending in JSON_FILE_EXTENSION and
+      # attempt to delete subdirectories (ignoring errors).
       for dir_name, subdir_list, file_list in os.walk(
           output_dir, topdown=False):
         for file_name in file_list:
-          if not file_name.endswith(".json.gz"):
+          if not file_name.endswith(JSON_FILE_EXTENSION):
             os.remove(os.path.join(dir_name, file_name))
         for subdir in subdir_list:
           try:
diff --git a/deps/v8/tools/heap-stats/categories.js b/deps/v8/tools/heap-stats/categories.js
index 765d8f3a31..9837acce3d 100644
--- a/deps/v8/tools/heap-stats/categories.js
+++ b/deps/v8/tools/heap-stats/categories.js
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // Categories for instance types.
-const CATEGORIES = new Map([
+export const CATEGORIES = new Map([
   [
     'user', new Set([
       'CONS_ONE_BYTE_STRING_TYPE',
@@ -204,7 +204,7 @@ const CATEGORIES = new Map([
 ]);
 
 // Maps category to description text that is shown in html.
-const CATEGORY_NAMES = new Map([
+export const CATEGORY_NAMES = new Map([
   ['user', 'JS'],
   ['system', 'Metadata'],
   ['code', 'Code'],
diff --git a/deps/v8/tools/heap-stats/details-selection.html b/deps/v8/tools/heap-stats/details-selection-template.html
index 04b274a8d1..cd429bf1a5 100644
--- a/deps/v8/tools/heap-stats/details-selection.html
+++ b/deps/v8/tools/heap-stats/details-selection-template.html
@@ -1,7 +1,6 @@
 <!-- Copyright 2018 the V8 project authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file. -->
-<template id="details-selection-template">
 <style>
 #dataSelectionSection {
   display: none;
@@ -139,7 +138,3 @@ found in the LICENSE file. -->
 
   <div id="categories"></div>
 </section>
-</template>
-
-<script type="text/javascript" src="categories.js"></script>
-<script type="text/javascript" src="details-selection.js"></script>
diff --git a/deps/v8/tools/heap-stats/details-selection.js b/deps/v8/tools/heap-stats/details-selection.js
index 1e9cc83cff..f7e32733d9 100644
--- a/deps/v8/tools/heap-stats/details-selection.js
+++ b/deps/v8/tools/heap-stats/details-selection.js
@@ -4,19 +4,18 @@
 
 'use strict';
 
-const details_selection_template =
-    document.currentScript.ownerDocument.querySelector(
-        '#details-selection-template');
+import {CATEGORIES, CATEGORY_NAMES} from './categories.js';
 
-const VIEW_BY_INSTANCE_TYPE = 'by-instance-type';
-const VIEW_BY_INSTANCE_CATEGORY = 'by-instance-category';
-const VIEW_BY_FIELD_TYPE = 'by-field-type';
+export const VIEW_BY_INSTANCE_TYPE = 'by-instance-type';
+export const VIEW_BY_INSTANCE_CATEGORY = 'by-instance-category';
+export const VIEW_BY_FIELD_TYPE = 'by-field-type';
 
-class DetailsSelection extends HTMLElement {
+defineCustomElement('details-selection', (templateText) =>
+ class DetailsSelection extends HTMLElement {
   constructor() {
     super();
     const shadowRoot = this.attachShadow({mode: 'open'});
-    shadowRoot.appendChild(details_selection_template.content.cloneNode(true));
+    shadowRoot.innerHTML = templateText;
     this.isolateSelect.addEventListener(
         'change', e => this.handleIsolateChange(e));
     this.dataViewSelect.addEventListener(
@@ -403,6 +402,4 @@ class DetailsSelection extends HTMLElement {
     link.click();
     this.shadowRoot.removeChild(link);
   }
-}
-
-customElements.define('details-selection', DetailsSelection);
+});
diff --git a/deps/v8/tools/heap-stats/global-timeline.html b/deps/v8/tools/heap-stats/global-timeline-template.html
index 788f966735..bb11b44961 100644
--- a/deps/v8/tools/heap-stats/global-timeline.html
+++ b/deps/v8/tools/heap-stats/global-timeline-template.html
@@ -1,7 +1,6 @@
 <!-- Copyright 2018 the V8 project authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file. -->
-<template id="global-timeline-template">
 <style>
 #chart {
   width: 100%;
@@ -12,5 +11,3 @@ found in the LICENSE file. -->
   <h2>Timeline</h2>
   <div id="chart"></div>
 </div>
-</template>
-<script type="text/javascript" src="global-timeline.js"></script>
\ No newline at end of file
diff --git a/deps/v8/tools/heap-stats/global-timeline.js b/deps/v8/tools/heap-stats/global-timeline.js
index c34ba2b913..2f16b1bdfb 100644
--- a/deps/v8/tools/heap-stats/global-timeline.js
+++ b/deps/v8/tools/heap-stats/global-timeline.js
@@ -4,15 +4,18 @@
 
 'use strict';
 
-const global_timeline_template =
-    document.currentScript.ownerDocument.querySelector(
-        '#global-timeline-template');
-
-class GlobalTimeline extends HTMLElement {
+import {
+  VIEW_BY_INSTANCE_TYPE,
+  VIEW_BY_INSTANCE_CATEGORY,
+  VIEW_BY_FIELD_TYPE
+} from './details-selection.js';
+
+defineCustomElement('global-timeline', (templateText) =>
+ class GlobalTimeline extends HTMLElement {
   constructor() {
     super();
     const shadowRoot = this.attachShadow({mode: 'open'});
-    shadowRoot.appendChild(global_timeline_template.content.cloneNode(true));
+    shadowRoot.innerHTML = templateText;
   }
 
   $(id) {
@@ -217,6 +220,4 @@ class GlobalTimeline extends HTMLElement {
     this.show();
     chart.draw(data, google.charts.Line.convertOptions(options));
   }
-}
-
-customElements.define('global-timeline', GlobalTimeline);
+});
diff --git a/deps/v8/tools/heap-stats/helper.js b/deps/v8/tools/heap-stats/helper.js
index 00f68f9d62..8416407ecc 100644
--- a/deps/v8/tools/heap-stats/helper.js
+++ b/deps/v8/tools/heap-stats/helper.js
@@ -21,3 +21,10 @@ function formatBytes(bytes) {
 function formatSeconds(millis) {
   return (millis * kMillis2Seconds).toFixed(2) + 's';
 }
+
+function defineCustomElement(name, generator) {
+  let htmlTemplatePath = name + '-template.html';
+  fetch(htmlTemplatePath)
+    .then(stream => stream.text())
+    .then(templateText => customElements.define(name, generator(templateText)));
+}
diff --git a/deps/v8/tools/heap-stats/histogram-viewer.html b/deps/v8/tools/heap-stats/histogram-viewer-template.html
index 93fe980978..42c8e706af 100644
--- a/deps/v8/tools/heap-stats/histogram-viewer.html
+++ b/deps/v8/tools/heap-stats/histogram-viewer-template.html
@@ -1,7 +1,6 @@
 <!-- Copyright 2018 the V8 project authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file. -->
-<template id="histogram-viewer-template">
 <style>
 #chart {
   width: 100%;
@@ -15,5 +14,3 @@ found in the LICENSE file. -->
   </ul>
   <div id="chart"></div>
 </div>
-</template>
-<script type="text/javascript"  src="histogram-viewer.js"></script>
\ No newline at end of file
diff --git a/deps/v8/tools/heap-stats/histogram-viewer.js b/deps/v8/tools/heap-stats/histogram-viewer.js
index 240c6cbc7e..4f1e02f8c6 100644
--- a/deps/v8/tools/heap-stats/histogram-viewer.js
+++ b/deps/v8/tools/heap-stats/histogram-viewer.js
@@ -4,15 +4,18 @@
 
 'use strict';
 
-const histogram_viewer_template =
-    document.currentScript.ownerDocument.querySelector(
-        '#histogram-viewer-template');
-
-class HistogramViewer extends HTMLElement {
+import {
+  VIEW_BY_INSTANCE_TYPE,
+  VIEW_BY_INSTANCE_CATEGORY,
+  VIEW_BY_FIELD_TYPE
+} from './details-selection.js';
+
+defineCustomElement('histogram-viewer', (templateText) =>
+ class HistogramViewer extends HTMLElement {
   constructor() {
     super();
     const shadowRoot = this.attachShadow({mode: 'open'});
-    shadowRoot.appendChild(histogram_viewer_template.content.cloneNode(true));
+    shadowRoot.innerHTML = templateText;
   }
 
   $(id) {
@@ -185,6 +188,4 @@ class HistogramViewer extends HTMLElement {
     this.show();
     chart.draw(data, options);
   }
-}
-
-customElements.define('histogram-viewer', HistogramViewer);
+});
diff --git a/deps/v8/tools/heap-stats/index.html b/deps/v8/tools/heap-stats/index.html
index 11fac21a3d..efb74af011 100644
--- a/deps/v8/tools/heap-stats/index.html
+++ b/deps/v8/tools/heap-stats/index.html
@@ -16,12 +16,14 @@ found in the LICENSE file. -->
           integrity="sha256-N1z6ddQzX83fjw8v7uSNe7/MgOmMKdwFUv1+AJMDqNM="
           crossorigin="anonymous"></script>
 
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/oboe.js/2.1.5/oboe-browser.min.js"
+          crossorigin="anonymous"></script>
   <script src="helper.js"></script>
 
-  <link rel="import" href="details-selection.html">
-  <link rel="import" href="global-timeline.html">
-  <link rel="import" href="histogram-viewer.html">
-  <link rel="import" href="trace-file-reader.html">
+  <script type="module" src="details-selection.js"></script>
+  <script type="module" src="global-timeline.js"></script>
+  <script type="module" src="histogram-viewer.js"></script>
+  <script type="module" src="trace-file-reader.js"></script>
 
   <style>
 body {
diff --git a/deps/v8/tools/heap-stats/model.js b/deps/v8/tools/heap-stats/model.js
index cd6e1e514e..d284d9b213 100644
--- a/deps/v8/tools/heap-stats/model.js
+++ b/deps/v8/tools/heap-stats/model.js
@@ -4,7 +4,7 @@
 
 'use strict';
 
-class Isolate {
+export class Isolate {
   constructor(address) {
     this.address = address;
     this.start = null;
diff --git a/deps/v8/tools/heap-stats/trace-file-reader.html b/deps/v8/tools/heap-stats/trace-file-reader-template.html
index c5e5c6f04a..c0fadbf1a1 100644
--- a/deps/v8/tools/heap-stats/trace-file-reader.html
+++ b/deps/v8/tools/heap-stats/trace-file-reader-template.html
@@ -1,7 +1,6 @@
 <!-- Copyright 2018 the V8 project authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file. -->
-<template id="trace-file-reader-template">
 <style>
 #fileReader {
   width: 100%;
@@ -80,7 +79,3 @@ found in the LICENSE file. -->
     <div id="spinner"></div>
   </div>
 </section>
-</template>
-<script type="text/javascript" src="model.js"></script>
-
-<script src="trace-file-reader.js"></script>
diff --git a/deps/v8/tools/heap-stats/trace-file-reader.js b/deps/v8/tools/heap-stats/trace-file-reader.js
index 86d9d7d551..e297723e6f 100644
--- a/deps/v8/tools/heap-stats/trace-file-reader.js
+++ b/deps/v8/tools/heap-stats/trace-file-reader.js
@@ -4,15 +4,14 @@
 
 'use strict';
 
-const trace_file_reader_template =
-    document.currentScript.ownerDocument.querySelector(
-        '#trace-file-reader-template');
+import {Isolate} from './model.js';
 
-class TraceFileReader extends HTMLElement {
+defineCustomElement('trace-file-reader', (templateText) =>
+ class TraceFileReader extends HTMLElement {
   constructor() {
     super();
     const shadowRoot = this.attachShadow({mode: 'open'});
-    shadowRoot.appendChild(trace_file_reader_template.content.cloneNode(true));
+    shadowRoot.innerHTML = templateText;
     this.addEventListener('click', e => this.handleClick(e));
     this.addEventListener('dragover', e => this.handleDragOver(e));
     this.addEventListener('drop', e => this.handleChange(e));
@@ -96,10 +95,13 @@ class TraceFileReader extends HTMLElement {
   }
 
   processRawText(file, result) {
-    let contents = result.split('\n');
-    const return_data = (result.includes('V8.GC_Objects_Stats')) ?
-        this.createModelFromChromeTraceFile(contents) :
-        this.createModelFromV8TraceFile(contents);
+    let return_data;
+    if (result.includes('V8.GC_Objects_Stats')) {
+      return_data = this.createModelFromChromeTraceFile(result);
+    } else {
+      let contents = result.split('\n');
+      return_data = this.createModelFromV8TraceFile(contents);
+    }
     this.extendAndSanitizeModel(return_data);
     this.updateLabel('Finished loading \'' + file.name + '\'.');
     this.dispatchEvent(new CustomEvent(
@@ -176,74 +178,62 @@ class TraceFileReader extends HTMLElement {
   }
 
   createModelFromChromeTraceFile(contents) {
-    // Trace files support two formats.
-    // {traceEvents: [ data ]}
-    const kObjectTraceFile = {
-      name: 'object',
-      endToken: ']}',
-      getDataArray: o => o.traceEvents
-    };
-    // [ data ]
-    const kArrayTraceFile = {
-      name: 'array',
-      endToken: ']',
-      getDataArray: o => o
-    };
-    const handler =
-        (contents[0][0] === '{') ? kObjectTraceFile : kArrayTraceFile;
-    console.log(`Processing log as chrome trace file (${handler.name}).`);
+    const data = Object.create(null);  // Final data container.
+    const parseOneGCEvent = (actual_data) => {
+      Object.keys(actual_data).forEach(data_set => {
+        const string_entry = actual_data[data_set];
+        try {
+          const entry = JSON.parse(string_entry);
+          this.createOrUpdateEntryIfNeeded(data, entry);
+          this.createDatasetIfNeeded(data, entry, data_set);
+          const isolate = entry.isolate;
+          const time = entry.time;
+          const gc_id = entry.id;
+          data[isolate].gcs[gc_id].time = time;
 
-    // Pop last line in log as it might be broken.
-    contents.pop();
-    // Remove trailing comma.
-    contents[contents.length - 1] = contents[contents.length - 1].slice(0, -1);
-    // Terminate JSON.
-    const sanitized_contents = [...contents, handler.endToken].join('');
+          const field_data = entry.field_data;
+          this.addFieldTypeData(data, isolate, gc_id, data_set,
+            field_data.tagged_fields,
+            field_data.inobject_smi_fields,
+            field_data.embedder_fields,
+            field_data.unboxed_double_fields,
+            field_data.boxed_double_fields,
+            field_data.string_data,
+            field_data.other_raw_fields);
 
-    const data = Object.create(null);  // Final data container.
+          data[isolate].gcs[gc_id][data_set].bucket_sizes =
+              entry.bucket_sizes;
+          for (let [instance_type, value] of Object.entries(
+                   entry.type_data)) {
+            // Trace file format uses markers that do not have actual
+            // properties.
+            if (!('overall' in value)) continue;
+            this.addInstanceTypeData(
+                data, isolate, gc_id, data_set, instance_type, value);
+          }
+        } catch (e) {
+          console.error('Unable to parse data set entry', e);
+        }
+      });
+    };
+    console.log(`Processing log as chrome trace file.`);
     try {
-      const raw_data = JSON.parse(sanitized_contents);
-      const raw_array_data = handler.getDataArray(raw_data);
-      raw_array_data.filter(e => e.name === 'V8.GC_Objects_Stats')
-          .forEach(trace_data => {
-            const actual_data = trace_data.args;
-            const data_sets = new Set(Object.keys(actual_data));
-            Object.keys(actual_data).forEach(data_set => {
-              const string_entry = actual_data[data_set];
-              try {
-                const entry = JSON.parse(string_entry);
-                this.createOrUpdateEntryIfNeeded(data, entry);
-                this.createDatasetIfNeeded(data, entry, data_set);
-                const isolate = entry.isolate;
-                const time = entry.time;
-                const gc_id = entry.id;
-                data[isolate].gcs[gc_id].time = time;
-
-                const field_data = entry.field_data;
-                this.addFieldTypeData(data, isolate, gc_id, data_set,
-                  field_data.tagged_fields,
-                  field_data.inobject_smi_fields,
-                  field_data.embedder_fields,
-                  field_data.unboxed_double_fields,
-                  field_data.boxed_double_fields,
-                  field_data.string_data,
-                  field_data.other_raw_fields);
+      let gc_events_filter = (event) => {
+        if (event.name == 'V8.GC_Objects_Stats') {
+          parseOneGCEvent(event.args);
+        }
+        return oboe.drop;
+      };
 
-                data[isolate].gcs[gc_id][data_set].bucket_sizes =
-                    entry.bucket_sizes;
-                for (let [instance_type, value] of Object.entries(
-                         entry.type_data)) {
-                  // Trace file format uses markers that do not have actual
-                  // properties.
-                  if (!('overall' in value)) continue;
-                  this.addInstanceTypeData(
-                      data, isolate, gc_id, data_set, instance_type, value);
-                }
-              } catch (e) {
-                console.log('Unable to parse data set entry', e);
-              }
-            });
-          });
+      let oboe_stream = oboe();
+      // Trace files support two formats.
+      oboe_stream
+          // 1) {traceEvents: [ data ]}
+          .node('traceEvents.*', gc_events_filter)
+          // 2) [ data ]
+          .node('!.*', gc_events_filter)
+          .fail(() => { throw new Error("Trace data parse failed!"); });
+      oboe_stream.emit('data', contents);
     } catch (e) {
       console.error('Unable to parse chrome trace file.', e);
     }
@@ -314,6 +304,4 @@ class TraceFileReader extends HTMLElement {
     }
     return data;
   }
-}
-
-customElements.define('trace-file-reader', TraceFileReader);
+});
diff --git a/deps/v8/tools/map-processor.html b/deps/v8/tools/map-processor.html
index 70c205c771..a453c9a189 100644
--- a/deps/v8/tools/map-processor.html
+++ b/deps/v8/tools/map-processor.html
@@ -113,6 +113,17 @@ h1, h2, h3, section {
   max-height: 200px;
   overflow-y: scroll;
 }
+
+#stats .transitionType {
+  text-align: right;
+}
+#stats .transitionType tr td:nth-child(2) {
+  text-align: left;
+}
+#stats .transitionType tr:nth-child(1) td {
+  border-bottom: 1px black dotted;
+}
+
 #timeline {
   position: relative;
   height: 300px;
@@ -436,9 +447,9 @@ function td(textOrNode) {
   return node;
 }
 
+
 function tr() {
-  let node = document.createElement("tr");
-  return node;
+  return document.createElement("tr");
 }
 
 function define(prototype, name, fn) {
@@ -1103,7 +1114,7 @@ class StatsView {
     ];
 
     let text = "";
-    let tableNode = table();
+    let tableNode = table("transitionType");
     let name, filter;
     let total = this.timeline.size();
     pairs.forEach(([name, color, filter]) => {
@@ -1120,7 +1131,7 @@ class StatsView {
       let count = this.timeline.count(filter);
       row.appendChild(td(count));
       let percent = Math.round(count / total * 1000) / 10;
-      row.appendChild(td(percent + "%"));
+      row.appendChild(td(percent.toFixed(1) + "%"));
       tableNode.appendChild(row);
     });
     this.node.appendChild(tableNode);
@@ -1204,7 +1215,7 @@ function transitionTypeToColor(type) {
 
   <h2>Instructions</h2>
   <section>
-    <p>Visualize Map trees that have been gathere using <code>--trace-maps</code>.</p>
+    <p>Visualize Map trees that have been gathered using <code>--trace-maps</code>.</p>
   </section>
 
   <div id="tooltip">
diff --git a/deps/v8/tools/mb/mb.py b/deps/v8/tools/mb/mb.py
index cd638bda27..f3e46158b9 100755
--- a/deps/v8/tools/mb/mb.py
+++ b/deps/v8/tools/mb/mb.py
@@ -64,6 +64,8 @@ class MetaBuildWrapper(object):
     self.luci_tryservers = {}
     self.masters = {}
     self.mixins = {}
+    self.isolate_exe = 'isolate.exe' if self.platform.startswith(
+        'win') else 'isolate'
 
   def Main(self, args):
     self.ParseArgs(args)
@@ -360,19 +362,39 @@ class MetaBuildWrapper(object):
     for k, v in self._DefaultDimensions() + self.args.dimensions:
       dimensions += ['-d', k, v]
 
+    archive_json_path = self.ToSrcRelPath(
+        '%s/%s.archive.json' % (build_dir, target))
     cmd = [
-        self.executable,
-        self.PathJoin('tools', 'swarming_client', 'isolate.py'),
+        self.PathJoin(self.chromium_src_dir, 'tools', 'luci-go',
+                      self.isolate_exe),
         'archive',
+        '-i',
+        self.ToSrcRelPath('%s/%s.isolate' % (build_dir, target)),
         '-s',
         self.ToSrcRelPath('%s/%s.isolated' % (build_dir, target)),
         '-I', 'isolateserver.appspot.com',
+        '-dump-json',
+        archive_json_path,
       ]
-    ret, out, _ = self.Run(cmd, force_verbose=False)
+    ret, _, _ = self.Run(cmd, force_verbose=False)
     if ret:
       return ret
 
-    isolated_hash = out.splitlines()[0].split()[0]
+    try:
+      archive_hashes = json.loads(self.ReadFile(archive_json_path))
+    except Exception:
+      self.Print(
+          'Failed to read JSON file "%s"' % archive_json_path, file=sys.stderr)
+      return 1
+    try:
+      isolated_hash = archive_hashes[target]
+    except Exception:
+      self.Print(
+          'Cannot find hash for "%s" in "%s", file content: %s' %
+          (target, archive_json_path, archive_hashes),
+          file=sys.stderr)
+      return 1
+
     cmd = [
         self.executable,
         self.PathJoin('tools', 'swarming_client', 'swarming.py'),
@@ -388,11 +410,11 @@ class MetaBuildWrapper(object):
 
   def _RunLocallyIsolated(self, build_dir, target):
     cmd = [
-        self.executable,
-        self.PathJoin('tools', 'swarming_client', 'isolate.py'),
+        self.PathJoin(self.chromium_src_dir, 'tools', 'luci-go',
+                      self.isolate_exe),
         'run',
-        '-s',
-        self.ToSrcRelPath('%s/%s.isolated' % (build_dir, target)),
+        '-i',
+        self.ToSrcRelPath('%s/%s.isolate' % (build_dir, target)),
       ]
     if self.args.extra_args:
       cmd += ['--'] + self.args.extra_args
@@ -789,13 +811,11 @@ class MetaBuildWrapper(object):
     self.WriteIsolateFiles(build_dir, target, runtime_deps)
 
     ret, _, _ = self.Run([
-        self.executable,
-        self.PathJoin('tools', 'swarming_client', 'isolate.py'),
+        self.PathJoin(self.chromium_src_dir, 'tools', 'luci-go',
+                      self.isolate_exe),
         'check',
         '-i',
-        self.ToSrcRelPath('%s/%s.isolate' % (build_dir, target)),
-        '-s',
-        self.ToSrcRelPath('%s/%s.isolated' % (build_dir, target))],
+        self.ToSrcRelPath('%s/%s.isolate' % (build_dir, target))],
         buffer_output=False)
 
     return ret
diff --git a/deps/v8/tools/mb/mb_unittest.py b/deps/v8/tools/mb/mb_unittest.py
index a22686a5ee..3a0b89b29d 100755
--- a/deps/v8/tools/mb/mb_unittest.py
+++ b/deps/v8/tools/mb/mb_unittest.py
@@ -533,16 +533,11 @@ class UnitTest(unittest.TestCase):
       '/fake_src/out/Default/base_unittests.runtime_deps': (
           "base_unittests\n"
       ),
+      'out/Default/base_unittests.archive.json':
+        ("{\"base_unittests\":\"fake_hash\"}"),
     }
 
-    def run_stub(cmd, **_kwargs):
-      if 'isolate.py' in cmd[1]:
-        return 0, 'fake_hash base_unittests', ''
-      else:
-        return 0, '', ''
-
     mbw = self.fake_mbw(files=files)
-    mbw.Run = run_stub
     self.check(['run', '-s', '-c', 'debug_goma', '//out/Default',
                 'base_unittests'], mbw=mbw, ret=0)
     self.check(['run', '-s', '-c', 'debug_goma', '-d', 'os', 'Win7',
diff --git a/deps/v8/tools/profile.js b/deps/v8/tools/profile.js
index ef362712fe..f8829679db 100644
--- a/deps/v8/tools/profile.js
+++ b/deps/v8/tools/profile.js
@@ -169,8 +169,12 @@ Profile.prototype.addFuncCode = function(
     if (entry.size === size && entry.func === func) {
       // Entry state has changed.
       entry.state = state;
+    } else {
+      this.codeMap_.deleteCode(start);
+      entry = null;
     }
-  } else {
+  }
+  if (!entry) {
     entry = new Profile.DynamicFuncCodeEntry(size, type, func, state);
     this.codeMap_.addCode(start, entry);
   }
@@ -935,14 +939,16 @@ JsonProfile.prototype.addFuncCode = function(
   // TODO(jarin): Insert the code object into the SFI's code list.
   var entry = this.codeMap_.findDynamicEntryByStartAddress(start);
   if (entry) {
-    // TODO(jarin) This does not look correct, we should really
-    // update the code object (remove the old one and insert this one).
     if (entry.size === size && entry.func === func) {
       // Entry state has changed.
       entry.state = state;
+    } else {
+      this.codeMap_.deleteCode(start);
+      entry = null;
     }
-  } else {
-    var entry = new CodeMap.CodeEntry(size, name, 'JS');
+  }
+  if (!entry) {
+    entry = new CodeMap.CodeEntry(size, name, 'JS');
     this.codeMap_.addCode(start, entry);
 
     entry.codeId = this.codeEntries_.length;
diff --git a/deps/v8/tools/release/git_recipes.py b/deps/v8/tools/release/git_recipes.py
index 0997e0bb89..716d146136 100644
--- a/deps/v8/tools/release/git_recipes.py
+++ b/deps/v8/tools/release/git_recipes.py
@@ -227,7 +227,6 @@ class GitRecipesMixin(object):
       args += ["--cc", Quoted(cc)]
     if message_file:
       args += ["--message-file", Quoted(message_file)]
-    args += ["--gerrit"]
     # TODO(machenbach): Check output in forced mode. Verify that all required
     # base files were uploaded, if not retry.
     self.Git(MakeArgs(args), pipe=False, **kwargs)
diff --git a/deps/v8/tools/release/test_scripts.py b/deps/v8/tools/release/test_scripts.py
index 36ee6c1d44..44376b1dc3 100755
--- a/deps/v8/tools/release/test_scripts.py
+++ b/deps/v8/tools/release/test_scripts.py
@@ -470,7 +470,7 @@ TBR=reviewer@chromium.org"""
           cb=CheckVersionCommit),
       Cmd("git cl upload --send-mail "
           "-f --bypass-hooks --no-autocc --message-file "
-          "\"%s\" --gerrit" % TEST_CONFIG["COMMITMSG_FILE"], ""),
+          "\"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], ""),
       Cmd("git cl land --bypass-hooks -f", ""),
       Cmd("git fetch", ""),
       Cmd("git log -1 --format=%H --grep="
@@ -621,7 +621,7 @@ deps = {
            self.ROLL_COMMIT_MSG),
           "", cwd=chrome_dir),
       Cmd("git cl upload --send-mail -f "
-          "--cq-dry-run --bypass-hooks --gerrit", "",
+          "--cq-dry-run --bypass-hooks", "",
           cwd=chrome_dir),
       Cmd("git checkout -f master", "", cwd=chrome_dir),
       Cmd("git branch -D work-branch", "", cwd=chrome_dir),
@@ -773,7 +773,7 @@ BUG=123,234,345,456,567,v8:123
       Cmd("git commit -aF \"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], ""),
       RL("reviewer@chromium.org"),  # V8 reviewer.
       Cmd("git cl upload --send-mail -r \"reviewer@chromium.org\" "
-          "--bypass-hooks --cc \"ulan@chromium.org\" --gerrit", ""),
+          "--bypass-hooks --cc \"ulan@chromium.org\"", ""),
       Cmd("git checkout -f %s" % TEST_CONFIG["BRANCHNAME"], ""),
       RL("LGTM"),  # Enter LGTM for V8 CL.
       Cmd("git cl presubmit", "Presubmit successfull\n"),
@@ -909,7 +909,7 @@ NOTREECHECKS=true
       Cmd("git commit -aF \"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], ""),
       RL("reviewer@chromium.org"),  # V8 reviewer.
       Cmd("git cl upload --send-mail -r \"reviewer@chromium.org\" "
-          "--bypass-hooks --cc \"ulan@chromium.org\" --gerrit", ""),
+          "--bypass-hooks --cc \"ulan@chromium.org\"", ""),
       Cmd("git checkout -f %s" % TEST_CONFIG["BRANCHNAME"], ""),
       RL("LGTM"),  # Enter LGTM for V8 CL.
       Cmd("git cl presubmit", "Presubmit successfull\n"),
diff --git a/deps/v8/tools/testrunner/base_runner.py b/deps/v8/tools/testrunner/base_runner.py
index c09b7cef39..43cb639c83 100644
--- a/deps/v8/tools/testrunner/base_runner.py
+++ b/deps/v8/tools/testrunner/base_runner.py
@@ -123,9 +123,8 @@ class ModeConfig(object):
     self.execution_mode = execution_mode
 
 
-DEBUG_FLAGS = ["--nohard-abort", "--enable-slow-asserts", "--verify-heap",
-               "--testing-d8-test-runner"]
-RELEASE_FLAGS = ["--nohard-abort", "--testing-d8-test-runner"]
+DEBUG_FLAGS = ["--nohard-abort", "--enable-slow-asserts", "--verify-heap"]
+RELEASE_FLAGS = ["--nohard-abort"]
 MODES = {
   "debug": ModeConfig(
     flags=DEBUG_FLAGS,
@@ -345,9 +344,8 @@ class BaseTestRunner(object):
                            "color, mono)")
     parser.add_option("--json-test-results",
                       help="Path to a file for storing json results.")
-    parser.add_option("--junitout", help="File name of the JUnit output")
-    parser.add_option("--junittestsuite", default="v8tests",
-                      help="The testsuite name in the JUnit output file")
+    parser.add_option('--slow-tests-cutoff', type="int", default=100,
+                      help='Collect N slowest tests')
     parser.add_option("--exit-after-n-failures", type="int", default=100,
                       help="Exit after the first N failures instead of "
                            "running all tests. Pass 0 to disable this feature.")
@@ -381,6 +379,8 @@ class BaseTestRunner(object):
                       help="Timeout for single test in seconds")
     parser.add_option("-v", "--verbose", default=False, action="store_true",
                       help="Verbose output")
+    parser.add_option('--regenerate-expected-files', default=False, action='store_true',
+                      help='Regenerate expected files')
 
     # TODO(machenbach): Temporary options for rolling out new test runner
     # features.
@@ -705,13 +705,17 @@ class BaseTestRunner(object):
       "pointer_compression": self.build_config.pointer_compression,
     }
 
+  def _runner_flags(self):
+    """Extra default flags specific to the test runner implementation."""
+    return []
+
   def _create_test_config(self, options):
     timeout = options.timeout * self._timeout_scalefactor(options)
     return TestConfig(
         command_prefix=options.command_prefix,
         extra_flags=options.extra_flags,
         isolates=options.isolates,
-        mode_flags=self.mode_options.flags,
+        mode_flags=self.mode_options.flags + self._runner_flags(),
         no_harness=options.no_harness,
         noi18n=self.build_config.no_i18n,
         random_seed=options.random_seed,
@@ -719,6 +723,7 @@ class BaseTestRunner(object):
         shell_dir=self.outdir,
         timeout=timeout,
         verbose=options.verbose,
+        regenerate_expected_files=options.regenerate_expected_files,
     )
 
   def _timeout_scalefactor(self, options):
@@ -792,13 +797,9 @@ class BaseTestRunner(object):
 
   def _create_progress_indicators(self, test_count, options):
     procs = [PROGRESS_INDICATORS[options.progress]()]
-    if options.junitout:
-      procs.append(progress.JUnitTestProgressIndicator(options.junitout,
-                                                       options.junittestsuite))
     if options.json_test_results:
       procs.append(progress.JsonTestProgressIndicator(
         self.framework_name,
-        options.json_test_results,
         self.build_config.arch,
         self.mode_options.execution_mode))
 
diff --git a/deps/v8/tools/testrunner/local/junit_output.py b/deps/v8/tools/testrunner/local/junit_output.py
deleted file mode 100644
index 52f31ec422..0000000000
--- a/deps/v8/tools/testrunner/local/junit_output.py
+++ /dev/null
@@ -1,49 +0,0 @@
-# Copyright 2013 the V8 project authors. All rights reserved.
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-#       notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-#       copyright notice, this list of conditions and the following
-#       disclaimer in the documentation and/or other materials provided
-#       with the distribution.
-#     * Neither the name of Google Inc. nor the names of its
-#       contributors may be used to endorse or promote products derived
-#       from this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-import xml.etree.ElementTree as xml
-
-
-class JUnitTestOutput:
-  def __init__(self, test_suite_name):
-    self.root = xml.Element("testsuite")
-    self.root.attrib["name"] = test_suite_name
-
-  def HasRunTest(self, test_name, test_cmd, test_duration, test_failure):
-    testCaseElement = xml.Element("testcase")
-    testCaseElement.attrib["name"] = test_name
-    testCaseElement.attrib["cmd"] = test_cmd
-    testCaseElement.attrib["time"] = str(round(test_duration, 3))
-    if len(test_failure):
-      failureElement = xml.Element("failure")
-      failureElement.text = test_failure
-      testCaseElement.append(failureElement)
-    self.root.append(testCaseElement)
-
-  def FinishAndWrite(self, f):
-    xml.ElementTree(self.root).write(f, "UTF-8")
diff --git a/deps/v8/tools/testrunner/local/pool.py b/deps/v8/tools/testrunner/local/pool.py
index a6fb91f912..f3f2e9dadc 100644
--- a/deps/v8/tools/testrunner/local/pool.py
+++ b/deps/v8/tools/testrunner/local/pool.py
@@ -196,10 +196,10 @@ class Pool():
             # gracefully, e.g. missing test files.
             internal_error = True
             continue
-
-          if self.abort_now:
-            # SIGINT, SIGTERM or internal hard timeout.
-            return
+          finally:
+            if self.abort_now:
+              # SIGINT, SIGTERM or internal hard timeout.
+              return
 
           yield result
           break
diff --git a/deps/v8/tools/testrunner/local/variants.py b/deps/v8/tools/testrunner/local/variants.py
index c363c2a5ec..7464978eb2 100644
--- a/deps/v8/tools/testrunner/local/variants.py
+++ b/deps/v8/tools/testrunner/local/variants.py
@@ -14,6 +14,7 @@ ALL_VARIANT_FLAGS = {
   "interpreted_regexp": [["--regexp-interpret-all"]],
   "jitless": [["--jitless"]],
   "minor_mc": [["--minor-mc"]],
+  "no_lfa": [["--no-lazy-feedback-allocation"]],
   # No optimization means disable all optimizations. OptimizeFunctionOnNextCall
   # would not force optimization too. It turns into a Nop. Please see
   # https://chromium-review.googlesource.com/c/452620/ for more discussion.
diff --git a/deps/v8/tools/testrunner/outproc/base.py b/deps/v8/tools/testrunner/outproc/base.py
index 39efb60fe9..9b65ca564a 100644
--- a/deps/v8/tools/testrunner/outproc/base.py
+++ b/deps/v8/tools/testrunner/outproc/base.py
@@ -19,8 +19,13 @@ OUTCOMES_FAIL_OR_TIMEOUT = [statusfile.FAIL, statusfile.TIMEOUT]
 class BaseOutProc(object):
   def process(self, output, reduction=None):
     has_unexpected_output = self.has_unexpected_output(output)
+    if has_unexpected_output:
+      self.regenerate_expected_files(output)
     return self._create_result(has_unexpected_output, output, reduction)
 
+  def regenerate_expected_files(self, output):
+    return
+
   def has_unexpected_output(self, output):
     return self.get_outcome(output) not in self.expected_outcomes
 
@@ -125,9 +130,11 @@ class ExpectedOutProc(OutProc):
   """Output processor that has is_failure_output depending on comparing the
   output with the expected output.
   """
-  def __init__(self, expected_outcomes, expected_filename):
+  def __init__(self, expected_outcomes, expected_filename,
+                regenerate_expected_files=False):
     super(ExpectedOutProc, self).__init__(expected_outcomes)
     self._expected_filename = expected_filename
+    self._regenerate_expected_files = regenerate_expected_files
 
   def _is_failure_output(self, output):
     with open(self._expected_filename, 'r') as f:
@@ -143,6 +150,14 @@ class ExpectedOutProc(OutProc):
           return True
       return False
 
+  def regenerate_expected_files(self, output):
+    if not self._regenerate_expected_files:
+      return
+    lines = output.stdout.splitlines()
+    with open(self._expected_filename, 'w') as f:
+      for _, line in enumerate(lines):
+        f.write(line+'\n')
+
   def _act_block_iterator(self, output):
     """Iterates over blocks of actual output lines."""
     lines = output.stdout.splitlines()
diff --git a/deps/v8/tools/testrunner/standard_runner.py b/deps/v8/tools/testrunner/standard_runner.py
index 0ca387000c..1b7acc41b7 100755
--- a/deps/v8/tools/testrunner/standard_runner.py
+++ b/deps/v8/tools/testrunner/standard_runner.py
@@ -50,6 +50,9 @@ VARIANT_ALIASES = {
             'instruction_scheduling'],
 }
 
+# Extra flags passed to all tests using the standard test runner.
+EXTRA_DEFAULT_FLAGS = ['--testing-d8-test-runner']
+
 GC_STRESS_FLAGS = ['--gc-interval=500', '--stress-compaction',
                    '--concurrent-recompilation-queue-length=64',
                    '--concurrent-recompilation-delay=500',
@@ -239,6 +242,9 @@ class StandardTestRunner(base_runner.BaseTestRunner):
           prefix="v8-test-runner-")
       options.json_test_results = self._temporary_json_output_file.name
 
+  def _runner_flags(self):
+    return EXTRA_DEFAULT_FLAGS
+
   def _parse_variants(self, aliases_str):
     # Use developer defaults if no variant was specified.
     aliases_str = aliases_str or 'dev'
diff --git a/deps/v8/tools/testrunner/test_config.py b/deps/v8/tools/testrunner/test_config.py
index 27ac72bf6c..fed6006069 100644
--- a/deps/v8/tools/testrunner/test_config.py
+++ b/deps/v8/tools/testrunner/test_config.py
@@ -19,7 +19,8 @@ class TestConfig(object):
                run_skipped,
                shell_dir,
                timeout,
-               verbose):
+               verbose,
+               regenerate_expected_files=False):
     self.command_prefix = command_prefix
     self.extra_flags = extra_flags
     self.isolates = isolates
@@ -32,3 +33,4 @@ class TestConfig(object):
     self.shell_dir = shell_dir
     self.timeout = timeout
     self.verbose = verbose
+    self.regenerate_expected_files = regenerate_expected_files
diff --git a/deps/v8/tools/testrunner/testproc/fuzzer.py b/deps/v8/tools/testrunner/testproc/fuzzer.py
index 271737897a..b802368183 100644
--- a/deps/v8/tools/testrunner/testproc/fuzzer.py
+++ b/deps/v8/tools/testrunner/testproc/fuzzer.py
@@ -13,9 +13,12 @@ from . import base
 EXTRA_FLAGS = [
   (0.1, '--always-opt'),
   (0.1, '--assert-types'),
+  # TODO(mythria): https://crbug.com/v8/10243
+  # (0.1, '--budget-for-feedback-vector-allocation=0'),
   (0.1, '--cache=code'),
   (0.1, '--force-slow-path'),
   (0.2, '--future'),
+  (0.1, '--interrupt-budget=100'),
   (0.1, '--liftoff'),
   (0.2, '--no-analyze-environment-liveness'),
   (0.1, '--no-enable-sse3'),
@@ -29,6 +32,7 @@ EXTRA_FLAGS = [
   (0.1, '--no-enable-bmi2'),
   (0.1, '--no-enable-lzcnt'),
   (0.1, '--no-enable-popcnt'),
+  (0.3, '--no-lazy-feedback-allocation'),
   (0.1, '--no-liftoff'),
   (0.1, '--no-opt'),
   (0.2, '--no-regexp-tier-up'),
diff --git a/deps/v8/tools/testrunner/testproc/progress.py b/deps/v8/tools/testrunner/testproc/progress.py
index 9ae589dee0..3357eef76c 100644
--- a/deps/v8/tools/testrunner/testproc/progress.py
+++ b/deps/v8/tools/testrunner/testproc/progress.py
@@ -14,7 +14,6 @@ import sys
 import time
 
 from . import base
-from ..local import junit_output
 
 
 # Base dir of the build products for Release and Debug.
@@ -317,47 +316,8 @@ class MonochromeProgressIndicator(CompactProgressIndicator):
     print(("\r" + (" " * last_length) + "\r"), end='')
 
 
-class JUnitTestProgressIndicator(ProgressIndicator):
-  def __init__(self, junitout, junittestsuite):
-    super(JUnitTestProgressIndicator, self).__init__()
-    self._requirement = base.DROP_PASS_STDOUT
-
-    self.outputter = junit_output.JUnitTestOutput(junittestsuite)
-    if junitout:
-      self.outfile = open(junitout, "w")
-    else:
-      self.outfile = sys.stdout
-
-  def _on_result_for(self, test, result):
-    # TODO(majeski): Support for dummy/grouped results
-    fail_text = ""
-    output = result.output
-    if result.has_unexpected_output:
-      stdout = output.stdout.strip()
-      if len(stdout):
-        fail_text += "stdout:\n%s\n" % stdout
-      stderr = output.stderr.strip()
-      if len(stderr):
-        fail_text += "stderr:\n%s\n" % stderr
-      fail_text += "Command: %s" % result.cmd.to_string()
-      if output.HasCrashed():
-        fail_text += "exit code: %d\n--- CRASHED ---" % output.exit_code
-      if output.HasTimedOut():
-        fail_text += "--- TIMEOUT ---"
-    self.outputter.HasRunTest(
-        test_name=str(test),
-        test_cmd=result.cmd.to_string(relative=True),
-        test_duration=output.duration,
-        test_failure=fail_text)
-
-  def finished(self):
-    self.outputter.FinishAndWrite(self.outfile)
-    if self.outfile != sys.stdout:
-      self.outfile.close()
-
-
 class JsonTestProgressIndicator(ProgressIndicator):
-  def __init__(self, framework_name, json_test_results, arch, mode):
+  def __init__(self, framework_name, arch, mode):
     super(JsonTestProgressIndicator, self).__init__()
     # We want to drop stdout/err for all passed tests on the first try, but we
     # need to get outputs for all runs after the first one. To accommodate that,
@@ -366,7 +326,6 @@ class JsonTestProgressIndicator(ProgressIndicator):
     self._requirement = base.DROP_PASS_STDOUT
 
     self.framework_name = framework_name
-    self.json_test_results = json_test_results
     self.arch = arch
     self.mode = mode
     self.results = []
@@ -412,8 +371,8 @@ class JsonTestProgressIndicator(ProgressIndicator):
 
   def finished(self):
     complete_results = []
-    if os.path.exists(self.json_test_results):
-      with open(self.json_test_results, "r") as f:
+    if os.path.exists(self.options.json_test_results):
+      with open(self.options.json_test_results, "r") as f:
         # On bots we might start out with an empty file.
         complete_results = json.loads(f.read() or "[]")
 
@@ -426,15 +385,8 @@ class JsonTestProgressIndicator(ProgressIndicator):
 
     # Sort tests by duration.
     self.tests.sort(key=lambda __duration_cmd: __duration_cmd[1], reverse=True)
-    slowest_tests = [
-      {
-        "name": str(test),
-        "flags": cmd.args,
-        "command": cmd.to_string(relative=True),
-        "duration": duration,
-        "marked_slow": test.is_slow,
-      } for (test, duration, cmd) in self.tests[:20]
-    ]
+    cutoff = self.options.slow_tests_cutoff
+    slowest_tests = self._test_records(self.tests[:cutoff])
 
     complete_results.append({
       "arch": self.arch,
@@ -445,5 +397,16 @@ class JsonTestProgressIndicator(ProgressIndicator):
       "test_total": len(self.tests),
     })
 
-    with open(self.json_test_results, "w") as f:
+    with open(self.options.json_test_results, "w") as f:
       f.write(json.dumps(complete_results))
+
+  def _test_records(self, tests):
+    return [
+      {
+        "name": str(test),
+        "flags": cmd.args,
+        "command": cmd.to_string(relative=True),
+        "duration": duration,
+        "marked_slow": test.is_slow,
+      } for (test, duration, cmd) in tests
+    ]
diff --git a/deps/v8/tools/tickprocessor-driver.js b/deps/v8/tools/tickprocessor-driver.js
index 93331cfa2d..d0e21785ce 100644
--- a/deps/v8/tools/tickprocessor-driver.js
+++ b/deps/v8/tools/tickprocessor-driver.js
@@ -62,7 +62,7 @@ if (params.sourceMap) {
   sourceMap = SourceMap.load(params.sourceMap);
 }
 var tickProcessor = new TickProcessor(
-  new (entriesProviders[params.platform])(params.nm, params.targetRootFS,
+  new (entriesProviders[params.platform])(params.nm, params.objdump, params.targetRootFS,
                                           params.apkEmbeddedLibrary),
   params.separateIc,
   params.separateBytecodes,
diff --git a/deps/v8/tools/tickprocessor.js b/deps/v8/tools/tickprocessor.js
index 34c2249fcc..2a5b9af83c 100644
--- a/deps/v8/tools/tickprocessor.js
+++ b/deps/v8/tools/tickprocessor.js
@@ -706,10 +706,14 @@ CppEntriesProvider.prototype.parseNextLine = function() {
 };
 
 
-function UnixCppEntriesProvider(nmExec, targetRootFS, apkEmbeddedLibrary) {
+function UnixCppEntriesProvider(nmExec, objdumpExec, targetRootFS, apkEmbeddedLibrary) {
   this.symbols = [];
+  // File offset of a symbol minus the virtual address of a symbol found in
+  // the symbol table.
+  this.fileOffsetMinusVma = 0;
   this.parsePos = 0;
   this.nmExec = nmExec;
+  this.objdumpExec = objdumpExec;
   this.targetRootFS = targetRootFS;
   this.apkEmbeddedLibrary = apkEmbeddedLibrary;
   this.FUNC_RE = /^([0-9a-fA-F]{8,16}) ([0-9a-fA-F]{8,16} )?[tTwW] (.*)$/;
@@ -731,6 +735,14 @@ UnixCppEntriesProvider.prototype.loadSymbols = function(libName) {
       os.system(this.nmExec, ['-C', '-n', '-S', libName], -1, -1),
       os.system(this.nmExec, ['-C', '-n', '-S', '-D', libName], -1, -1)
     ];
+
+    const objdumpOutput = os.system(this.objdumpExec, ['-h', libName], -1, -1);
+    for (const line of objdumpOutput.split('\n')) {
+      const [,sectionName,,vma,,fileOffset] = line.trim().split(/\s+/);
+      if (sectionName === ".text") {
+        this.fileOffsetMinusVma = parseInt(fileOffset, 16) - parseInt(vma, 16);
+      }
+    }
   } catch (e) {
     // If the library cannot be found on this system let's not panic.
     this.symbols = ['', ''];
@@ -754,7 +766,7 @@ UnixCppEntriesProvider.prototype.parseNextLine = function() {
   var fields = line.match(this.FUNC_RE);
   var funcInfo = null;
   if (fields) {
-    funcInfo = { name: fields[3], start: parseInt(fields[1], 16) };
+    funcInfo = { name: fields[3], start: parseInt(fields[1], 16) + this.fileOffsetMinusVma };
     if (fields[2]) {
       funcInfo.size = parseInt(fields[2], 16);
     }
@@ -763,8 +775,8 @@ UnixCppEntriesProvider.prototype.parseNextLine = function() {
 };
 
 
-function MacCppEntriesProvider(nmExec, targetRootFS, apkEmbeddedLibrary) {
-  UnixCppEntriesProvider.call(this, nmExec, targetRootFS, apkEmbeddedLibrary);
+function MacCppEntriesProvider(nmExec, objdumpExec, targetRootFS, apkEmbeddedLibrary) {
+  UnixCppEntriesProvider.call(this, nmExec, objdumpExec, targetRootFS, apkEmbeddedLibrary);
   // Note an empty group. It is required, as UnixCppEntriesProvider expects 3 groups.
   this.FUNC_RE = /^([0-9a-fA-F]{8,16})() (.*)$/;
 };
@@ -786,7 +798,7 @@ MacCppEntriesProvider.prototype.loadSymbols = function(libName) {
 };
 
 
-function WindowsCppEntriesProvider(_ignored_nmExec, targetRootFS,
+function WindowsCppEntriesProvider(_ignored_nmExec, _ignored_objdumpExec, targetRootFS,
                                    _ignored_apkEmbeddedLibrary) {
   this.targetRootFS = targetRootFS;
   this.symbols = '';
@@ -909,6 +921,8 @@ class ArgumentsProcessor extends BaseArgumentsProcessor {
           'Specify that we are running on Mac OS X platform'],
       '--nm': ['nm', 'nm',
           'Specify the \'nm\' executable to use (e.g. --nm=/my_dir/nm)'],
+      '--objdump': ['objdump', 'objdump',
+          'Specify the \'objdump\' executable to use (e.g. --objdump=/my_dir/objdump)'],
       '--target': ['targetRootFS', '',
           'Specify the target root directory for cross environment'],
       '--apk-embedded-library': ['apkEmbeddedLibrary', '',
@@ -951,6 +965,7 @@ class ArgumentsProcessor extends BaseArgumentsProcessor {
       preprocessJson: null,
       targetRootFS: '',
       nm: 'nm',
+      objdump: 'objdump',
       range: 'auto,auto',
       distortion: 0,
       timedRange: false,
diff --git a/deps/v8/tools/unittests/run_tests_test.py b/deps/v8/tools/unittests/run_tests_test.py
index 116266ca42..14d999b5f4 100755
--- a/deps/v8/tools/unittests/run_tests_test.py
+++ b/deps/v8/tools/unittests/run_tests_test.py
@@ -665,6 +665,24 @@ class SystemTest(unittest.TestCase):
 
       self.assertEqual(0, result.returncode, result)
 
+  def testRunnerFlags(self):
+    """Test that runner-specific flags are passed to tests."""
+    with temp_base() as basedir:
+      result = run_tests(
+          basedir,
+          '--mode=Release',
+          '--progress=verbose',
+          '--variants=default',
+          '--random-seed=42',
+          'sweet/bananas',
+          '-v',
+      )
+
+      self.assertIn(
+          '--test bananas --random-seed=42 --nohard-abort --testing-d8-test-runner',
+          result.stdout, result)
+      self.assertEqual(0, result.returncode, result)
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/deps/v8/tools/v8_presubmit.py b/deps/v8/tools/v8_presubmit.py
index f2f9546bdb..40677b3a0a 100755
--- a/deps/v8/tools/v8_presubmit.py
+++ b/deps/v8/tools/v8_presubmit.py
@@ -325,7 +325,13 @@ class CppLintProcessor(CacheableSourceFileProcessor):
     return (super(CppLintProcessor, self).IgnoreDir(name)
             or (name == 'third_party'))
 
-  IGNORE_LINT = ['export-template.h', 'flag-definitions.h']
+  IGNORE_LINT = [
+    'export-template.h',
+    'flag-definitions.h',
+    'gay-fixed.cc',
+    'gay-precision.cc',
+    'gay-shortest.cc',
+  ]
 
   def IgnoreFile(self, name):
     return (super(CppLintProcessor, self).IgnoreFile(name)
diff --git a/deps/v8/tools/v8heapconst.py b/deps/v8/tools/v8heapconst.py
index ccd02e67bf..07c4ebf8cb 100644
--- a/deps/v8/tools/v8heapconst.py
+++ b/deps/v8/tools/v8heapconst.py
@@ -29,8 +29,8 @@ INSTANCE_TYPES = {
   65: "BIG_INT_BASE_TYPE",
   66: "HEAP_NUMBER_TYPE",
   67: "ODDBALL_TYPE",
-  68: "SOURCE_TEXT_MODULE_TYPE",
-  69: "SYNTHETIC_MODULE_TYPE",
+  68: "EXPORTED_SUB_CLASS_BASE_TYPE",
+  69: "EXPORTED_SUB_CLASS_TYPE",
   70: "FOREIGN_TYPE",
   71: "PROMISE_FULFILL_REACTION_JOB_TASK_TYPE",
   72: "PROMISE_REJECT_REACTION_JOB_TASK_TYPE",
@@ -60,83 +60,88 @@ INSTANCE_TYPES = {
   96: "FEEDBACK_CELL_TYPE",
   97: "FUNCTION_TEMPLATE_RARE_DATA_TYPE",
   98: "INTERCEPTOR_INFO_TYPE",
-  99: "INTERNAL_CLASS_TYPE",
-  100: "INTERPRETER_DATA_TYPE",
-  101: "PROMISE_CAPABILITY_TYPE",
-  102: "PROMISE_REACTION_TYPE",
-  103: "PROPERTY_DESCRIPTOR_OBJECT_TYPE",
-  104: "PROTOTYPE_INFO_TYPE",
-  105: "SCRIPT_TYPE",
-  106: "SMI_BOX_TYPE",
-  107: "SMI_PAIR_TYPE",
-  108: "SORT_STATE_TYPE",
-  109: "SOURCE_TEXT_MODULE_INFO_ENTRY_TYPE",
-  110: "STACK_FRAME_INFO_TYPE",
-  111: "STACK_TRACE_FRAME_TYPE",
-  112: "TEMPLATE_OBJECT_DESCRIPTION_TYPE",
-  113: "TUPLE2_TYPE",
-  114: "WASM_CAPI_FUNCTION_DATA_TYPE",
-  115: "WASM_DEBUG_INFO_TYPE",
-  116: "WASM_EXCEPTION_TAG_TYPE",
-  117: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
-  118: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
-  119: "WASM_JS_FUNCTION_DATA_TYPE",
-  120: "FIXED_ARRAY_TYPE",
-  121: "HASH_TABLE_TYPE",
-  122: "EPHEMERON_HASH_TABLE_TYPE",
-  123: "GLOBAL_DICTIONARY_TYPE",
-  124: "NAME_DICTIONARY_TYPE",
-  125: "NUMBER_DICTIONARY_TYPE",
-  126: "ORDERED_HASH_MAP_TYPE",
-  127: "ORDERED_HASH_SET_TYPE",
-  128: "ORDERED_NAME_DICTIONARY_TYPE",
-  129: "SIMPLE_NUMBER_DICTIONARY_TYPE",
-  130: "STRING_TABLE_TYPE",
-  131: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
-  132: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
-  133: "SCOPE_INFO_TYPE",
-  134: "SCRIPT_CONTEXT_TABLE_TYPE",
-  135: "BYTE_ARRAY_TYPE",
-  136: "BYTECODE_ARRAY_TYPE",
-  137: "FIXED_DOUBLE_ARRAY_TYPE",
-  138: "AWAIT_CONTEXT_TYPE",
-  139: "BLOCK_CONTEXT_TYPE",
-  140: "CATCH_CONTEXT_TYPE",
-  141: "DEBUG_EVALUATE_CONTEXT_TYPE",
-  142: "EVAL_CONTEXT_TYPE",
-  143: "FUNCTION_CONTEXT_TYPE",
-  144: "MODULE_CONTEXT_TYPE",
-  145: "NATIVE_CONTEXT_TYPE",
-  146: "SCRIPT_CONTEXT_TYPE",
-  147: "WITH_CONTEXT_TYPE",
-  148: "SMALL_ORDERED_HASH_MAP_TYPE",
-  149: "SMALL_ORDERED_HASH_SET_TYPE",
-  150: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
-  151: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
-  152: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
-  153: "WEAK_FIXED_ARRAY_TYPE",
-  154: "TRANSITION_ARRAY_TYPE",
-  155: "CELL_TYPE",
-  156: "CODE_TYPE",
-  157: "CODE_DATA_CONTAINER_TYPE",
+  99: "INTERPRETER_DATA_TYPE",
+  100: "PROMISE_CAPABILITY_TYPE",
+  101: "PROMISE_REACTION_TYPE",
+  102: "PROPERTY_DESCRIPTOR_OBJECT_TYPE",
+  103: "PROTOTYPE_INFO_TYPE",
+  104: "SCRIPT_TYPE",
+  105: "SOURCE_TEXT_MODULE_INFO_ENTRY_TYPE",
+  106: "STACK_FRAME_INFO_TYPE",
+  107: "STACK_TRACE_FRAME_TYPE",
+  108: "TEMPLATE_OBJECT_DESCRIPTION_TYPE",
+  109: "TUPLE2_TYPE",
+  110: "WASM_CAPI_FUNCTION_DATA_TYPE",
+  111: "WASM_DEBUG_INFO_TYPE",
+  112: "WASM_EXCEPTION_TAG_TYPE",
+  113: "WASM_EXPORTED_FUNCTION_DATA_TYPE",
+  114: "WASM_INDIRECT_FUNCTION_TABLE_TYPE",
+  115: "WASM_JS_FUNCTION_DATA_TYPE",
+  116: "FIXED_ARRAY_TYPE",
+  117: "HASH_TABLE_TYPE",
+  118: "EPHEMERON_HASH_TABLE_TYPE",
+  119: "GLOBAL_DICTIONARY_TYPE",
+  120: "NAME_DICTIONARY_TYPE",
+  121: "NUMBER_DICTIONARY_TYPE",
+  122: "ORDERED_HASH_MAP_TYPE",
+  123: "ORDERED_HASH_SET_TYPE",
+  124: "ORDERED_NAME_DICTIONARY_TYPE",
+  125: "SIMPLE_NUMBER_DICTIONARY_TYPE",
+  126: "STRING_TABLE_TYPE",
+  127: "CLOSURE_FEEDBACK_CELL_ARRAY_TYPE",
+  128: "OBJECT_BOILERPLATE_DESCRIPTION_TYPE",
+  129: "SCOPE_INFO_TYPE",
+  130: "SCRIPT_CONTEXT_TABLE_TYPE",
+  131: "BYTE_ARRAY_TYPE",
+  132: "BYTECODE_ARRAY_TYPE",
+  133: "FIXED_DOUBLE_ARRAY_TYPE",
+  134: "INTERNAL_CLASS_WITH_SMI_ELEMENTS_TYPE",
+  135: "AWAIT_CONTEXT_TYPE",
+  136: "BLOCK_CONTEXT_TYPE",
+  137: "CATCH_CONTEXT_TYPE",
+  138: "DEBUG_EVALUATE_CONTEXT_TYPE",
+  139: "EVAL_CONTEXT_TYPE",
+  140: "FUNCTION_CONTEXT_TYPE",
+  141: "MODULE_CONTEXT_TYPE",
+  142: "NATIVE_CONTEXT_TYPE",
+  143: "SCRIPT_CONTEXT_TYPE",
+  144: "WITH_CONTEXT_TYPE",
+  145: "SMALL_ORDERED_HASH_MAP_TYPE",
+  146: "SMALL_ORDERED_HASH_SET_TYPE",
+  147: "SMALL_ORDERED_NAME_DICTIONARY_TYPE",
+  148: "SOURCE_TEXT_MODULE_TYPE",
+  149: "SYNTHETIC_MODULE_TYPE",
+  150: "UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE",
+  151: "UNCOMPILED_DATA_WITHOUT_PREPARSE_DATA_TYPE",
+  152: "WEAK_FIXED_ARRAY_TYPE",
+  153: "TRANSITION_ARRAY_TYPE",
+  154: "CELL_TYPE",
+  155: "CODE_TYPE",
+  156: "CODE_DATA_CONTAINER_TYPE",
+  157: "COVERAGE_INFO_TYPE",
   158: "DESCRIPTOR_ARRAY_TYPE",
   159: "EMBEDDER_DATA_ARRAY_TYPE",
   160: "FEEDBACK_METADATA_TYPE",
   161: "FEEDBACK_VECTOR_TYPE",
   162: "FILLER_TYPE",
   163: "FREE_SPACE_TYPE",
-  164: "MAP_TYPE",
-  165: "PREPARSE_DATA_TYPE",
-  166: "PROPERTY_ARRAY_TYPE",
-  167: "PROPERTY_CELL_TYPE",
-  168: "SHARED_FUNCTION_INFO_TYPE",
-  169: "WEAK_ARRAY_LIST_TYPE",
-  170: "WEAK_CELL_TYPE",
-  171: "JS_PROXY_TYPE",
+  164: "INTERNAL_CLASS_TYPE",
+  165: "INTERNAL_CLASS_WITH_STRUCT_ELEMENTS_TYPE",
+  166: "MAP_TYPE",
+  167: "PREPARSE_DATA_TYPE",
+  168: "PROPERTY_ARRAY_TYPE",
+  169: "PROPERTY_CELL_TYPE",
+  170: "SHARED_FUNCTION_INFO_TYPE",
+  171: "SMI_BOX_TYPE",
+  172: "SMI_PAIR_TYPE",
+  173: "SORT_STATE_TYPE",
+  174: "WEAK_ARRAY_LIST_TYPE",
+  175: "WEAK_CELL_TYPE",
+  176: "JS_PROXY_TYPE",
   1057: "JS_OBJECT_TYPE",
-  172: "JS_GLOBAL_OBJECT_TYPE",
-  173: "JS_GLOBAL_PROXY_TYPE",
-  174: "JS_MODULE_NAMESPACE_TYPE",
+  177: "JS_GLOBAL_OBJECT_TYPE",
+  178: "JS_GLOBAL_PROXY_TYPE",
+  179: "JS_MODULE_NAMESPACE_TYPE",
   1040: "JS_SPECIAL_API_OBJECT_TYPE",
   1041: "JS_PRIMITIVE_WRAPPER_TYPE",
   1042: "JS_MAP_KEY_ITERATOR_TYPE",
@@ -165,8 +170,8 @@ INSTANCE_TYPES = {
   1066: "JS_DATE_TIME_FORMAT_TYPE",
   1067: "JS_DISPLAY_NAMES_TYPE",
   1068: "JS_ERROR_TYPE",
-  1069: "JS_FINALIZATION_GROUP_TYPE",
-  1070: "JS_FINALIZATION_GROUP_CLEANUP_ITERATOR_TYPE",
+  1069: "JS_FINALIZATION_REGISTRY_TYPE",
+  1070: "JS_FINALIZATION_REGISTRY_CLEANUP_ITERATOR_TYPE",
   1071: "JS_LIST_FORMAT_TYPE",
   1072: "JS_LOCALE_TYPE",
   1073: "JS_MESSAGE_OBJECT_TYPE",
@@ -194,10 +199,10 @@ INSTANCE_TYPES = {
 # List of known V8 maps.
 KNOWN_MAPS = {
   ("read_only_space", 0x00121): (163, "FreeSpaceMap"),
-  ("read_only_space", 0x00149): (164, "MetaMap"),
+  ("read_only_space", 0x00149): (166, "MetaMap"),
   ("read_only_space", 0x0018d): (67, "NullMap"),
   ("read_only_space", 0x001c5): (158, "DescriptorArrayMap"),
-  ("read_only_space", 0x001f5): (153, "WeakFixedArrayMap"),
+  ("read_only_space", 0x001f5): (152, "WeakFixedArrayMap"),
   ("read_only_space", 0x0021d): (162, "OnePointerFillerMap"),
   ("read_only_space", 0x00245): (162, "TwoPointerFillerMap"),
   ("read_only_space", 0x00289): (67, "UninitializedMap"),
@@ -206,19 +211,19 @@ KNOWN_MAPS = {
   ("read_only_space", 0x0035d): (66, "HeapNumberMap"),
   ("read_only_space", 0x003a1): (67, "TheHoleMap"),
   ("read_only_space", 0x00401): (67, "BooleanMap"),
-  ("read_only_space", 0x00489): (135, "ByteArrayMap"),
-  ("read_only_space", 0x004b1): (120, "FixedArrayMap"),
-  ("read_only_space", 0x004d9): (120, "FixedCOWArrayMap"),
-  ("read_only_space", 0x00501): (121, "HashTableMap"),
+  ("read_only_space", 0x00489): (131, "ByteArrayMap"),
+  ("read_only_space", 0x004b1): (116, "FixedArrayMap"),
+  ("read_only_space", 0x004d9): (116, "FixedCOWArrayMap"),
+  ("read_only_space", 0x00501): (117, "HashTableMap"),
   ("read_only_space", 0x00529): (64, "SymbolMap"),
   ("read_only_space", 0x00551): (40, "OneByteStringMap"),
-  ("read_only_space", 0x00579): (133, "ScopeInfoMap"),
-  ("read_only_space", 0x005a1): (168, "SharedFunctionInfoMap"),
-  ("read_only_space", 0x005c9): (156, "CodeMap"),
-  ("read_only_space", 0x005f1): (155, "CellMap"),
-  ("read_only_space", 0x00619): (167, "GlobalPropertyCellMap"),
+  ("read_only_space", 0x00579): (129, "ScopeInfoMap"),
+  ("read_only_space", 0x005a1): (170, "SharedFunctionInfoMap"),
+  ("read_only_space", 0x005c9): (155, "CodeMap"),
+  ("read_only_space", 0x005f1): (154, "CellMap"),
+  ("read_only_space", 0x00619): (169, "GlobalPropertyCellMap"),
   ("read_only_space", 0x00641): (70, "ForeignMap"),
-  ("read_only_space", 0x00669): (154, "TransitionArrayMap"),
+  ("read_only_space", 0x00669): (153, "TransitionArrayMap"),
   ("read_only_space", 0x00691): (45, "ThinOneByteStringMap"),
   ("read_only_space", 0x006b9): (161, "FeedbackVectorMap"),
   ("read_only_space", 0x0070d): (67, "ArgumentsMarkerMap"),
@@ -226,113 +231,118 @@ KNOWN_MAPS = {
   ("read_only_space", 0x007c9): (67, "TerminationExceptionMap"),
   ("read_only_space", 0x00831): (67, "OptimizedOutMap"),
   ("read_only_space", 0x00891): (67, "StaleRegisterMap"),
-  ("read_only_space", 0x008d5): (134, "ScriptContextTableMap"),
-  ("read_only_space", 0x008fd): (131, "ClosureFeedbackCellArrayMap"),
+  ("read_only_space", 0x008d5): (130, "ScriptContextTableMap"),
+  ("read_only_space", 0x008fd): (127, "ClosureFeedbackCellArrayMap"),
   ("read_only_space", 0x00925): (160, "FeedbackMetadataArrayMap"),
-  ("read_only_space", 0x0094d): (120, "ArrayListMap"),
+  ("read_only_space", 0x0094d): (116, "ArrayListMap"),
   ("read_only_space", 0x00975): (65, "BigIntMap"),
-  ("read_only_space", 0x0099d): (132, "ObjectBoilerplateDescriptionMap"),
-  ("read_only_space", 0x009c5): (136, "BytecodeArrayMap"),
-  ("read_only_space", 0x009ed): (157, "CodeDataContainerMap"),
-  ("read_only_space", 0x00a15): (137, "FixedDoubleArrayMap"),
-  ("read_only_space", 0x00a3d): (123, "GlobalDictionaryMap"),
-  ("read_only_space", 0x00a65): (96, "ManyClosuresCellMap"),
-  ("read_only_space", 0x00a8d): (120, "ModuleInfoMap"),
-  ("read_only_space", 0x00ab5): (124, "NameDictionaryMap"),
-  ("read_only_space", 0x00add): (96, "NoClosuresCellMap"),
-  ("read_only_space", 0x00b05): (125, "NumberDictionaryMap"),
-  ("read_only_space", 0x00b2d): (96, "OneClosureCellMap"),
-  ("read_only_space", 0x00b55): (126, "OrderedHashMapMap"),
-  ("read_only_space", 0x00b7d): (127, "OrderedHashSetMap"),
-  ("read_only_space", 0x00ba5): (128, "OrderedNameDictionaryMap"),
-  ("read_only_space", 0x00bcd): (165, "PreparseDataMap"),
-  ("read_only_space", 0x00bf5): (166, "PropertyArrayMap"),
-  ("read_only_space", 0x00c1d): (92, "SideEffectCallHandlerInfoMap"),
-  ("read_only_space", 0x00c45): (92, "SideEffectFreeCallHandlerInfoMap"),
-  ("read_only_space", 0x00c6d): (92, "NextCallSideEffectFreeCallHandlerInfoMap"),
-  ("read_only_space", 0x00c95): (129, "SimpleNumberDictionaryMap"),
-  ("read_only_space", 0x00cbd): (120, "SloppyArgumentsElementsMap"),
-  ("read_only_space", 0x00ce5): (148, "SmallOrderedHashMapMap"),
-  ("read_only_space", 0x00d0d): (149, "SmallOrderedHashSetMap"),
-  ("read_only_space", 0x00d35): (150, "SmallOrderedNameDictionaryMap"),
-  ("read_only_space", 0x00d5d): (68, "SourceTextModuleMap"),
-  ("read_only_space", 0x00d85): (130, "StringTableMap"),
-  ("read_only_space", 0x00dad): (69, "SyntheticModuleMap"),
-  ("read_only_space", 0x00dd5): (152, "UncompiledDataWithoutPreparseDataMap"),
-  ("read_only_space", 0x00dfd): (151, "UncompiledDataWithPreparseDataMap"),
-  ("read_only_space", 0x00e25): (169, "WeakArrayListMap"),
-  ("read_only_space", 0x00e4d): (122, "EphemeronHashTableMap"),
-  ("read_only_space", 0x00e75): (159, "EmbedderDataArrayMap"),
-  ("read_only_space", 0x00e9d): (170, "WeakCellMap"),
-  ("read_only_space", 0x00ec5): (32, "StringMap"),
-  ("read_only_space", 0x00eed): (41, "ConsOneByteStringMap"),
-  ("read_only_space", 0x00f15): (33, "ConsStringMap"),
-  ("read_only_space", 0x00f3d): (37, "ThinStringMap"),
-  ("read_only_space", 0x00f65): (35, "SlicedStringMap"),
-  ("read_only_space", 0x00f8d): (43, "SlicedOneByteStringMap"),
-  ("read_only_space", 0x00fb5): (34, "ExternalStringMap"),
-  ("read_only_space", 0x00fdd): (42, "ExternalOneByteStringMap"),
-  ("read_only_space", 0x01005): (50, "UncachedExternalStringMap"),
-  ("read_only_space", 0x0102d): (0, "InternalizedStringMap"),
-  ("read_only_space", 0x01055): (2, "ExternalInternalizedStringMap"),
-  ("read_only_space", 0x0107d): (10, "ExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x010a5): (18, "UncachedExternalInternalizedStringMap"),
-  ("read_only_space", 0x010cd): (26, "UncachedExternalOneByteInternalizedStringMap"),
-  ("read_only_space", 0x010f5): (58, "UncachedExternalOneByteStringMap"),
-  ("read_only_space", 0x0111d): (67, "SelfReferenceMarkerMap"),
-  ("read_only_space", 0x01151): (95, "EnumCacheMap"),
-  ("read_only_space", 0x011a1): (86, "ArrayBoilerplateDescriptionMap"),
-  ("read_only_space", 0x0129d): (98, "InterceptorInfoMap"),
-  ("read_only_space", 0x032ad): (71, "PromiseFulfillReactionJobTaskMap"),
-  ("read_only_space", 0x032d5): (72, "PromiseRejectReactionJobTaskMap"),
-  ("read_only_space", 0x032fd): (73, "CallableTaskMap"),
-  ("read_only_space", 0x03325): (74, "CallbackTaskMap"),
-  ("read_only_space", 0x0334d): (75, "PromiseResolveThenableJobTaskMap"),
-  ("read_only_space", 0x03375): (78, "FunctionTemplateInfoMap"),
-  ("read_only_space", 0x0339d): (79, "ObjectTemplateInfoMap"),
-  ("read_only_space", 0x033c5): (80, "AccessCheckInfoMap"),
-  ("read_only_space", 0x033ed): (81, "AccessorInfoMap"),
-  ("read_only_space", 0x03415): (82, "AccessorPairMap"),
-  ("read_only_space", 0x0343d): (83, "AliasedArgumentsEntryMap"),
-  ("read_only_space", 0x03465): (84, "AllocationMementoMap"),
-  ("read_only_space", 0x0348d): (87, "AsmWasmDataMap"),
-  ("read_only_space", 0x034b5): (88, "AsyncGeneratorRequestMap"),
-  ("read_only_space", 0x034dd): (89, "BreakPointMap"),
-  ("read_only_space", 0x03505): (90, "BreakPointInfoMap"),
-  ("read_only_space", 0x0352d): (91, "CachedTemplateObjectMap"),
-  ("read_only_space", 0x03555): (93, "ClassPositionsMap"),
-  ("read_only_space", 0x0357d): (94, "DebugInfoMap"),
-  ("read_only_space", 0x035a5): (97, "FunctionTemplateRareDataMap"),
-  ("read_only_space", 0x035cd): (100, "InterpreterDataMap"),
-  ("read_only_space", 0x035f5): (101, "PromiseCapabilityMap"),
-  ("read_only_space", 0x0361d): (102, "PromiseReactionMap"),
-  ("read_only_space", 0x03645): (103, "PropertyDescriptorObjectMap"),
-  ("read_only_space", 0x0366d): (104, "PrototypeInfoMap"),
-  ("read_only_space", 0x03695): (105, "ScriptMap"),
-  ("read_only_space", 0x036bd): (109, "SourceTextModuleInfoEntryMap"),
-  ("read_only_space", 0x036e5): (110, "StackFrameInfoMap"),
-  ("read_only_space", 0x0370d): (111, "StackTraceFrameMap"),
-  ("read_only_space", 0x03735): (112, "TemplateObjectDescriptionMap"),
-  ("read_only_space", 0x0375d): (113, "Tuple2Map"),
-  ("read_only_space", 0x03785): (114, "WasmCapiFunctionDataMap"),
-  ("read_only_space", 0x037ad): (115, "WasmDebugInfoMap"),
-  ("read_only_space", 0x037d5): (116, "WasmExceptionTagMap"),
-  ("read_only_space", 0x037fd): (117, "WasmExportedFunctionDataMap"),
-  ("read_only_space", 0x03825): (118, "WasmIndirectFunctionTableMap"),
-  ("read_only_space", 0x0384d): (119, "WasmJSFunctionDataMap"),
-  ("read_only_space", 0x03875): (99, "InternalClassMap"),
-  ("read_only_space", 0x0389d): (107, "SmiPairMap"),
-  ("read_only_space", 0x038c5): (106, "SmiBoxMap"),
-  ("read_only_space", 0x038ed): (108, "SortStateMap"),
-  ("read_only_space", 0x03915): (85, "AllocationSiteWithWeakNextMap"),
-  ("read_only_space", 0x0393d): (85, "AllocationSiteWithoutWeakNextMap"),
-  ("read_only_space", 0x03965): (76, "LoadHandler1Map"),
-  ("read_only_space", 0x0398d): (76, "LoadHandler2Map"),
-  ("read_only_space", 0x039b5): (76, "LoadHandler3Map"),
-  ("read_only_space", 0x039dd): (77, "StoreHandler0Map"),
-  ("read_only_space", 0x03a05): (77, "StoreHandler1Map"),
-  ("read_only_space", 0x03a2d): (77, "StoreHandler2Map"),
-  ("read_only_space", 0x03a55): (77, "StoreHandler3Map"),
+  ("read_only_space", 0x0099d): (128, "ObjectBoilerplateDescriptionMap"),
+  ("read_only_space", 0x009c5): (132, "BytecodeArrayMap"),
+  ("read_only_space", 0x009ed): (156, "CodeDataContainerMap"),
+  ("read_only_space", 0x00a15): (157, "CoverageInfoMap"),
+  ("read_only_space", 0x00a3d): (133, "FixedDoubleArrayMap"),
+  ("read_only_space", 0x00a65): (119, "GlobalDictionaryMap"),
+  ("read_only_space", 0x00a8d): (96, "ManyClosuresCellMap"),
+  ("read_only_space", 0x00ab5): (116, "ModuleInfoMap"),
+  ("read_only_space", 0x00add): (120, "NameDictionaryMap"),
+  ("read_only_space", 0x00b05): (96, "NoClosuresCellMap"),
+  ("read_only_space", 0x00b2d): (121, "NumberDictionaryMap"),
+  ("read_only_space", 0x00b55): (96, "OneClosureCellMap"),
+  ("read_only_space", 0x00b7d): (122, "OrderedHashMapMap"),
+  ("read_only_space", 0x00ba5): (123, "OrderedHashSetMap"),
+  ("read_only_space", 0x00bcd): (124, "OrderedNameDictionaryMap"),
+  ("read_only_space", 0x00bf5): (167, "PreparseDataMap"),
+  ("read_only_space", 0x00c1d): (168, "PropertyArrayMap"),
+  ("read_only_space", 0x00c45): (92, "SideEffectCallHandlerInfoMap"),
+  ("read_only_space", 0x00c6d): (92, "SideEffectFreeCallHandlerInfoMap"),
+  ("read_only_space", 0x00c95): (92, "NextCallSideEffectFreeCallHandlerInfoMap"),
+  ("read_only_space", 0x00cbd): (125, "SimpleNumberDictionaryMap"),
+  ("read_only_space", 0x00ce5): (116, "SloppyArgumentsElementsMap"),
+  ("read_only_space", 0x00d0d): (145, "SmallOrderedHashMapMap"),
+  ("read_only_space", 0x00d35): (146, "SmallOrderedHashSetMap"),
+  ("read_only_space", 0x00d5d): (147, "SmallOrderedNameDictionaryMap"),
+  ("read_only_space", 0x00d85): (148, "SourceTextModuleMap"),
+  ("read_only_space", 0x00dad): (126, "StringTableMap"),
+  ("read_only_space", 0x00dd5): (149, "SyntheticModuleMap"),
+  ("read_only_space", 0x00dfd): (151, "UncompiledDataWithoutPreparseDataMap"),
+  ("read_only_space", 0x00e25): (150, "UncompiledDataWithPreparseDataMap"),
+  ("read_only_space", 0x00e4d): (174, "WeakArrayListMap"),
+  ("read_only_space", 0x00e75): (118, "EphemeronHashTableMap"),
+  ("read_only_space", 0x00e9d): (159, "EmbedderDataArrayMap"),
+  ("read_only_space", 0x00ec5): (175, "WeakCellMap"),
+  ("read_only_space", 0x00eed): (32, "StringMap"),
+  ("read_only_space", 0x00f15): (41, "ConsOneByteStringMap"),
+  ("read_only_space", 0x00f3d): (33, "ConsStringMap"),
+  ("read_only_space", 0x00f65): (37, "ThinStringMap"),
+  ("read_only_space", 0x00f8d): (35, "SlicedStringMap"),
+  ("read_only_space", 0x00fb5): (43, "SlicedOneByteStringMap"),
+  ("read_only_space", 0x00fdd): (34, "ExternalStringMap"),
+  ("read_only_space", 0x01005): (42, "ExternalOneByteStringMap"),
+  ("read_only_space", 0x0102d): (50, "UncachedExternalStringMap"),
+  ("read_only_space", 0x01055): (0, "InternalizedStringMap"),
+  ("read_only_space", 0x0107d): (2, "ExternalInternalizedStringMap"),
+  ("read_only_space", 0x010a5): (10, "ExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x010cd): (18, "UncachedExternalInternalizedStringMap"),
+  ("read_only_space", 0x010f5): (26, "UncachedExternalOneByteInternalizedStringMap"),
+  ("read_only_space", 0x0111d): (58, "UncachedExternalOneByteStringMap"),
+  ("read_only_space", 0x01145): (67, "SelfReferenceMarkerMap"),
+  ("read_only_space", 0x01179): (95, "EnumCacheMap"),
+  ("read_only_space", 0x011c9): (86, "ArrayBoilerplateDescriptionMap"),
+  ("read_only_space", 0x012c5): (98, "InterceptorInfoMap"),
+  ("read_only_space", 0x032e5): (71, "PromiseFulfillReactionJobTaskMap"),
+  ("read_only_space", 0x0330d): (72, "PromiseRejectReactionJobTaskMap"),
+  ("read_only_space", 0x03335): (73, "CallableTaskMap"),
+  ("read_only_space", 0x0335d): (74, "CallbackTaskMap"),
+  ("read_only_space", 0x03385): (75, "PromiseResolveThenableJobTaskMap"),
+  ("read_only_space", 0x033ad): (78, "FunctionTemplateInfoMap"),
+  ("read_only_space", 0x033d5): (79, "ObjectTemplateInfoMap"),
+  ("read_only_space", 0x033fd): (80, "AccessCheckInfoMap"),
+  ("read_only_space", 0x03425): (81, "AccessorInfoMap"),
+  ("read_only_space", 0x0344d): (82, "AccessorPairMap"),
+  ("read_only_space", 0x03475): (83, "AliasedArgumentsEntryMap"),
+  ("read_only_space", 0x0349d): (84, "AllocationMementoMap"),
+  ("read_only_space", 0x034c5): (87, "AsmWasmDataMap"),
+  ("read_only_space", 0x034ed): (88, "AsyncGeneratorRequestMap"),
+  ("read_only_space", 0x03515): (89, "BreakPointMap"),
+  ("read_only_space", 0x0353d): (90, "BreakPointInfoMap"),
+  ("read_only_space", 0x03565): (91, "CachedTemplateObjectMap"),
+  ("read_only_space", 0x0358d): (93, "ClassPositionsMap"),
+  ("read_only_space", 0x035b5): (94, "DebugInfoMap"),
+  ("read_only_space", 0x035dd): (97, "FunctionTemplateRareDataMap"),
+  ("read_only_space", 0x03605): (99, "InterpreterDataMap"),
+  ("read_only_space", 0x0362d): (100, "PromiseCapabilityMap"),
+  ("read_only_space", 0x03655): (101, "PromiseReactionMap"),
+  ("read_only_space", 0x0367d): (102, "PropertyDescriptorObjectMap"),
+  ("read_only_space", 0x036a5): (103, "PrototypeInfoMap"),
+  ("read_only_space", 0x036cd): (104, "ScriptMap"),
+  ("read_only_space", 0x036f5): (105, "SourceTextModuleInfoEntryMap"),
+  ("read_only_space", 0x0371d): (106, "StackFrameInfoMap"),
+  ("read_only_space", 0x03745): (107, "StackTraceFrameMap"),
+  ("read_only_space", 0x0376d): (108, "TemplateObjectDescriptionMap"),
+  ("read_only_space", 0x03795): (109, "Tuple2Map"),
+  ("read_only_space", 0x037bd): (110, "WasmCapiFunctionDataMap"),
+  ("read_only_space", 0x037e5): (111, "WasmDebugInfoMap"),
+  ("read_only_space", 0x0380d): (112, "WasmExceptionTagMap"),
+  ("read_only_space", 0x03835): (113, "WasmExportedFunctionDataMap"),
+  ("read_only_space", 0x0385d): (114, "WasmIndirectFunctionTableMap"),
+  ("read_only_space", 0x03885): (115, "WasmJSFunctionDataMap"),
+  ("read_only_space", 0x038ad): (134, "InternalClassWithSmiElementsMap"),
+  ("read_only_space", 0x038d5): (165, "InternalClassWithStructElementsMap"),
+  ("read_only_space", 0x038fd): (164, "InternalClassMap"),
+  ("read_only_space", 0x03925): (172, "SmiPairMap"),
+  ("read_only_space", 0x0394d): (171, "SmiBoxMap"),
+  ("read_only_space", 0x03975): (68, "ExportedSubClassBaseMap"),
+  ("read_only_space", 0x0399d): (69, "ExportedSubClassMap"),
+  ("read_only_space", 0x039c5): (173, "SortStateMap"),
+  ("read_only_space", 0x039ed): (85, "AllocationSiteWithWeakNextMap"),
+  ("read_only_space", 0x03a15): (85, "AllocationSiteWithoutWeakNextMap"),
+  ("read_only_space", 0x03a3d): (76, "LoadHandler1Map"),
+  ("read_only_space", 0x03a65): (76, "LoadHandler2Map"),
+  ("read_only_space", 0x03a8d): (76, "LoadHandler3Map"),
+  ("read_only_space", 0x03ab5): (77, "StoreHandler0Map"),
+  ("read_only_space", 0x03add): (77, "StoreHandler1Map"),
+  ("read_only_space", 0x03b05): (77, "StoreHandler2Map"),
+  ("read_only_space", 0x03b2d): (77, "StoreHandler3Map"),
   ("map_space", 0x00121): (1057, "ExternalMap"),
   ("map_space", 0x00149): (1073, "JSMessageObjectMap"),
 }
@@ -357,32 +367,32 @@ KNOWN_OBJECTS = {
   ("read_only_space", 0x007ad): "TerminationException",
   ("read_only_space", 0x00815): "OptimizedOut",
   ("read_only_space", 0x00875): "StaleRegister",
-  ("read_only_space", 0x01145): "EmptyEnumCache",
-  ("read_only_space", 0x01179): "EmptyPropertyArray",
-  ("read_only_space", 0x01181): "EmptyByteArray",
-  ("read_only_space", 0x01189): "EmptyObjectBoilerplateDescription",
-  ("read_only_space", 0x01195): "EmptyArrayBoilerplateDescription",
-  ("read_only_space", 0x011c9): "EmptyClosureFeedbackCellArray",
-  ("read_only_space", 0x011d1): "EmptySloppyArgumentsElements",
-  ("read_only_space", 0x011e1): "EmptySlowElementDictionary",
-  ("read_only_space", 0x01205): "EmptyOrderedHashMap",
-  ("read_only_space", 0x01219): "EmptyOrderedHashSet",
-  ("read_only_space", 0x0122d): "EmptyFeedbackMetadata",
-  ("read_only_space", 0x01239): "EmptyPropertyCell",
-  ("read_only_space", 0x0124d): "EmptyPropertyDictionary",
-  ("read_only_space", 0x01275): "NoOpInterceptorInfo",
-  ("read_only_space", 0x012c5): "EmptyWeakArrayList",
-  ("read_only_space", 0x012d1): "InfinityValue",
-  ("read_only_space", 0x012dd): "MinusZeroValue",
-  ("read_only_space", 0x012e9): "MinusInfinityValue",
-  ("read_only_space", 0x012f5): "SelfReferenceMarker",
-  ("read_only_space", 0x01335): "OffHeapTrampolineRelocationInfo",
-  ("read_only_space", 0x01341): "TrampolineTrivialCodeDataContainer",
-  ("read_only_space", 0x0134d): "TrampolinePromiseRejectionCodeDataContainer",
-  ("read_only_space", 0x01359): "GlobalThisBindingScopeInfo",
-  ("read_only_space", 0x01391): "EmptyFunctionScopeInfo",
-  ("read_only_space", 0x013b9): "NativeScopeInfo",
-  ("read_only_space", 0x013d5): "HashSeed",
+  ("read_only_space", 0x0116d): "EmptyEnumCache",
+  ("read_only_space", 0x011a1): "EmptyPropertyArray",
+  ("read_only_space", 0x011a9): "EmptyByteArray",
+  ("read_only_space", 0x011b1): "EmptyObjectBoilerplateDescription",
+  ("read_only_space", 0x011bd): "EmptyArrayBoilerplateDescription",
+  ("read_only_space", 0x011f1): "EmptyClosureFeedbackCellArray",
+  ("read_only_space", 0x011f9): "EmptySloppyArgumentsElements",
+  ("read_only_space", 0x01209): "EmptySlowElementDictionary",
+  ("read_only_space", 0x0122d): "EmptyOrderedHashMap",
+  ("read_only_space", 0x01241): "EmptyOrderedHashSet",
+  ("read_only_space", 0x01255): "EmptyFeedbackMetadata",
+  ("read_only_space", 0x01261): "EmptyPropertyCell",
+  ("read_only_space", 0x01275): "EmptyPropertyDictionary",
+  ("read_only_space", 0x0129d): "NoOpInterceptorInfo",
+  ("read_only_space", 0x012ed): "EmptyWeakArrayList",
+  ("read_only_space", 0x012f9): "InfinityValue",
+  ("read_only_space", 0x01305): "MinusZeroValue",
+  ("read_only_space", 0x01311): "MinusInfinityValue",
+  ("read_only_space", 0x0131d): "SelfReferenceMarker",
+  ("read_only_space", 0x0135d): "OffHeapTrampolineRelocationInfo",
+  ("read_only_space", 0x01369): "TrampolineTrivialCodeDataContainer",
+  ("read_only_space", 0x01375): "TrampolinePromiseRejectionCodeDataContainer",
+  ("read_only_space", 0x01381): "GlobalThisBindingScopeInfo",
+  ("read_only_space", 0x013b9): "EmptyFunctionScopeInfo",
+  ("read_only_space", 0x013e1): "NativeScopeInfo",
+  ("read_only_space", 0x013fd): "HashSeed",
   ("old_space", 0x00121): "ArgumentsIteratorAccessor",
   ("old_space", 0x00165): "ArrayLengthAccessor",
   ("old_space", 0x001a9): "BoundFunctionLengthAccessor",
@@ -436,6 +446,7 @@ FRAME_MARKERS = (
   "WASM_TO_JS",
   "JS_TO_WASM",
   "WASM_INTERPRETER_ENTRY",
+  "WASM_DEBUG_BREAK",
   "C_WASM_ENTRY",
   "WASM_EXIT",
   "WASM_COMPILE_LAZY",
diff --git a/deps/v8/tools/v8windbg/BUILD.gn b/deps/v8/tools/v8windbg/BUILD.gn
new file mode 100644
index 0000000000..10d06a127f
--- /dev/null
+++ b/deps/v8/tools/v8windbg/BUILD.gn
@@ -0,0 +1,116 @@
+# Copyright 2020 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("../../gni/v8.gni")
+
+config("v8windbg_config") {
+  # Required for successful compilation of SDK header file DbgModel.h.
+  cflags_cc = [ "/Zc:twoPhase-" ]
+
+  include_dirs = [ "../.." ]
+}
+
+# Basic support for WinDbg extensions, with nothing specific to V8.
+source_set("v8windbg_base") {
+  testonly = true
+
+  sources = [
+    "base/dbgext.cc",
+    "base/dbgext.h",
+    "base/utilities.cc",
+    "base/utilities.h",
+  ]
+
+  libs = [
+    "DbgEng.lib",
+    "DbgModel.lib",
+    "RuntimeObject.lib",
+    "comsuppwd.lib",
+  ]
+
+  public_configs = [ ":v8windbg_config" ]
+}
+
+# An extension DLL that can be loaded into WinDbg with `.load v8windbg`.
+v8_shared_library("v8windbg") {
+  testonly = true
+
+  sources = [
+    "base/dbgext.def",
+    "src/cur-isolate.cc",
+    "src/cur-isolate.h",
+    "src/list-chunks.cc",
+    "src/list-chunks.h",
+    "src/local-variables.cc",
+    "src/local-variables.h",
+    "src/object-inspection.cc",
+    "src/object-inspection.h",
+    "src/v8-debug-helper-interop.cc",
+    "src/v8-debug-helper-interop.h",
+    "src/v8windbg-extension.cc",
+    "src/v8windbg-extension.h",
+  ]
+
+  deps = [
+    ":v8windbg_base",
+    "../debug_helper:v8_debug_helper",
+  ]
+}
+
+# Copies Windows SDK files that v8windbg_test needs.
+action("copy_prereqs") {
+  testonly = true
+
+  script = "copy-prereqs.py"
+
+  inputs = [
+    script,
+    "//build/vs_toolchain.py",
+  ]
+
+  outputs = [ "$root_out_dir/dbgeng.dll" ]
+
+  args = [
+    rebase_path("//build"),
+    rebase_path(root_out_dir),
+    target_cpu,
+  ]
+}
+
+# A test that launches a separate d8 process and debugs it using v8windbg.
+v8_source_set("v8windbg_test") {
+  testonly = true
+
+  sources = [
+    "test/debug-callbacks.cc",
+    "test/debug-callbacks.h",
+    "test/v8windbg-test.cc",
+    "test/v8windbg-test.h",
+  ]
+
+  deps = [ "../..:v8_libbase" ]  # For CHECK macro.
+
+  data_deps = [
+    ":copy_prereqs",
+    ":v8windbg",
+    ":v8windbg_test_script",
+    "../..:d8",
+  ]
+
+  libs = [
+    "DbgEng.lib",
+    "DbgModel.lib",
+    "Pathcch.lib",
+    "RuntimeObject.lib",
+  ]
+
+  configs = [ ":v8windbg_config" ]
+}
+
+# Copies the JavaScript file used by v8windbg_test.
+copy("v8windbg_test_script") {
+  testonly = true
+  sources = [ "test/script.js" ]
+  outputs = [ "$target_out_dir/v8windbg-test-script.js" ]
+}
diff --git a/deps/v8/tools/v8windbg/README.md b/deps/v8/tools/v8windbg/README.md
new file mode 100644
index 0000000000..dc0c4e1040
--- /dev/null
+++ b/deps/v8/tools/v8windbg/README.md
@@ -0,0 +1,151 @@
+# v8windbg
+
+V8windbg is a WinDbg extension for the V8 engine. It adjusts the behavior of the
+Locals pane and corresponding `dx` commands to display useful data when
+inspecting V8 object types. It is intended to be as robust as possible in dumps
+with limited memory, and should work equally well in live sessions, crash dumps,
+and time travel debugging.
+
+## Building
+
+Run `autoninja v8windbg` in your output directory.
+
+## Using
+
+In WinDbgX, run `.load path\to\your\output\dir\v8windbg.dll` to load the
+extension. To inspect V8 objects, use the Locals window or the `dx` command as
+usual.
+
+**Important notes:**
+
+- The version of v8windbg must exactly match the version and build configuration
+  of the process you're debugging. (To find the version number of a module in a
+  crash dump, enter `lm` and click the module name, or run `lmDvm modulename`.)
+- V8windbg relies on detailed symbols (symbol_level = 2).
+- Ensure also that WinDbg can load the symbols (.pdb file) for the module
+  containing V8.
+- Cross-architecture debugging is possible in some cases:
+  - To debug an x86 process on x64, load the x86 build of v8windbg.
+  - To debug an ARM64 process on x64, load the ARM64 simulator build of v8windbg
+    (built with target_cpu="x64" and v8_target_cpu="arm64").
+
+As well as improving the Locals pane behavior, v8windbg also provides a few
+functions that can be called from within `dx` commands:
+
+- `@$v8object()` returns information about the fields of a tagged V8 value,
+  passed in as a plain number like `dx @$v8object(0x34f49880471)`. This invokes
+  the same logic that is used for the locals pane. You may also pass a type hint
+  as an optional second parameter if you find that v8windbg is not inferring the
+  correct type (which can happen when the memory for the object's Map wasn't
+  collected in a crash dump). The type hint is a fully-qualified C++ class name,
+  like `dx @$v8object(0x34f49880471, "v8::internal::JSArray")`.
+- `@$curisolate()` gets the Isolate pointer for the current thread, if the
+  current thread has a JavaScript Isolate associated.
+- `@$listchunks()` returns a list of the memory chunks in the Heap for the
+  current Isolate.
+
+*Tip:*: to see what objects are present in a chunk of heap memory, you can cast
+it to an array of `TaggedValue`, like this:
+
+`dx (v8::internal::TaggedValue(*)[64])0x34f49880450`
+
+## Architecture
+
+V8windbg uses the [DataModel] as much as possible as opposed to the older
+[DbgEng] APIs. It uses the [WRL COM] APIs due to limitations in Clang's support
+for [C++/WinRT COM].
+
+Where possible, v8windbg uses the cross-platform v8_debug_helper library to
+avoid depending on V8 internals.
+
+The source in `./base` is a generic starting point for implementing a WinDbg
+extension. The V8-specific implementation under `./src` then implements the two
+functions declared in `dbgext.h` to create and destroy the extension instance.
+
+`./src` file index:
+
+- `cur-isolate.{cc,h}` implements the `IModelMethod` for `@$curisolate()`.
+- `list-chunks.{cc,h}` implements the `IModelMethod` for `@$listchunks()`. Its
+  result is a custom object that supports iteration and indexing.
+- `local-variables.{cc,h}` implements the `IModelPropertyAccessor` that provides
+  content to show in the Locals pane for stack frames corresponding to builtins
+  or runtime-generated code.
+- `object-inspection.{cc,h}` contains various classes that allow the debugger to
+  show fields within V8 objects.
+- `v8-debug-helper-interop.{cc,h}` makes requests to the V8 postmortem debugging
+  API, and converts the results into simple C++ structs.
+- `v8windbg-extension.{cc,h}` is responsible for initializing the extension and
+  cleaning up when the extension is unloaded.
+
+When the extension is initialized (`Extension::Initialize()`):
+
+- It registers a "parent model" for all known V8 object types, such as
+  `v8::internal::HeapObject` and `v8::internal::Symbol`. Any time WinDbg needs
+  to represent a value with one of these types, it creates an `IModelObject`
+  representing the value and attaches the parent model. This particular parent
+  model supports `IStringDisplayableConcept` and `IDynamicKeyProviderConcept`,
+  meaning the debugger will call a custom method every time it wants to get a
+  description string or a list of fields for any of these objects.
+- It registers a different parent model, with a single property getter named
+  "Value", for handle types such as `v8::internal::Handle<*>`. The "Value"
+  getter returns the correctly-typed tagged pointer contained by the handle.
+- It overrides the getter functions for "LocalVariables" and "Parameters" on the
+  parent model for stack frames. When the user selects a stack frame, WinDbg
+  calls these getter functions to determine what it should show in the Locals
+  pane.
+- It registers the function aliases such as `@$curisolate()`.
+
+The `./test` directory contains a test function that exercises v8windbg. It does
+not require WinDbg, but uses DbgEng.dll and DbgModel.dll from the Windows SDK
+(these are slightly older versions of the same modules used by WinDbg). The test
+function launches a separate d8 process, attaches to that process as a debugger,
+lets d8 run until it hits a breakpoint, and then checks the output of a few `dx`
+commands.
+
+## Debugging the extension
+
+To debug the extension, launch a WinDbgx instance to debug with an active
+target, e.g.
+
+`windbgx \src\github\v8\out\x64.debug\d8.exe -e "console.log('hello');"`
+
+or
+
+`windbgx \src\github\v8\out\x64.debug\d8.exe c:\temp\test.js`
+
+The WinDbgx process itself does not host the extensions, but uses a helper
+process. Attach another instance of WinDbgx to the `enghost.exe` helper process,
+e.g.
+
+`windbgx -pn enghost.exe`
+
+Set a breakpoint in this second session for when the extension initializes, e.g.
+
+`bm v8windbg!DebugExtensionInitialize`
+
+..and/or whenever a function of interest is invoked, e.g.
+
+ - `bp v8windbg!CurrIsolateAlias::Call` for the invocation of `@$curisolate()`
+ - `bp v8windbg!GetHeapObject` for the interpretation of V8 objects.
+
+Load the extension in the target debugger (the first WinDbg session), which
+should trigger the breakpoint.
+
+`.load "C:\\src\\github\\v8windbg\\x64\\v8windbg.dll"`
+
+Note: For D8, the below is a good breakpoint to set just before any script is
+run:
+
+`bp d8_exe!v8::Shell::ExecuteString`
+
+..or the below for once the V8 engine is entered (for component builds):
+
+`bp v8!v8::Script::Run`
+
+Then trigger the extension code of interest via something like `dx source` or
+`dx @$curisolate()`.
+
+[DataModel]: https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/data-model-cpp-overview
+[DbgEng]: https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/writing-dbgeng-extension-code
+[C++/WinRT COM]: https://docs.microsoft.com/en-us/windows/uwp/cpp-and-winrt-apis/consume-com
+[WRL COM]: https://docs.microsoft.com/en-us/cpp/cppcx/wrl/windows-runtime-cpp-template-library-wrl?view=vs-2019
diff --git a/deps/v8/tools/v8windbg/base/dbgext.cc b/deps/v8/tools/v8windbg/base/dbgext.cc
new file mode 100644
index 0000000000..e3f00951b4
--- /dev/null
+++ b/deps/v8/tools/v8windbg/base/dbgext.cc
@@ -0,0 +1,75 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/base/dbgext.h"
+
+#include <crtdbg.h>
+#include <wrl/module.h>
+
+#include "tools/v8windbg/base/utilities.h"
+
+// See
+// https://docs.microsoft.com/en-us/visualstudio/debugger/crt-debugging-techniques
+// for the memory leak and debugger reporting macros used from <crtdbg.h>
+_CrtMemState mem_old, mem_new, mem_diff;
+int original_crt_dbg_flag = 0;
+
+WRL::ComPtr<IDataModelManager> sp_data_model_manager;
+WRL::ComPtr<IDebugHost> sp_debug_host;
+WRL::ComPtr<IDebugControl5> sp_debug_control;
+WRL::ComPtr<IDebugHostMemory2> sp_debug_host_memory;
+WRL::ComPtr<IDebugHostSymbols> sp_debug_host_symbols;
+WRL::ComPtr<IDebugHostExtensibility> sp_debug_host_extensibility;
+
+extern "C" {
+
+HRESULT
+__stdcall DebugExtensionInitialize(PULONG /*pVersion*/, PULONG /*pFlags*/) {
+  original_crt_dbg_flag = _CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF);
+  _CrtMemCheckpoint(&mem_old);
+
+  WRL::ComPtr<IDebugClient> sp_debug_client;
+  WRL::ComPtr<IHostDataModelAccess> sp_data_model_access;
+
+  RETURN_IF_FAIL(DebugCreate(__uuidof(IDebugClient), &sp_debug_client));
+
+  RETURN_IF_FAIL(sp_debug_client.As(&sp_data_model_access));
+  RETURN_IF_FAIL(sp_debug_client.As(&sp_debug_control));
+
+  RETURN_IF_FAIL(sp_data_model_access->GetDataModel(&sp_data_model_manager,
+                                                    &sp_debug_host));
+
+  RETURN_IF_FAIL(sp_debug_host.As(&sp_debug_host_memory));
+  RETURN_IF_FAIL(sp_debug_host.As(&sp_debug_host_symbols));
+  RETURN_IF_FAIL(sp_debug_host.As(&sp_debug_host_extensibility));
+
+  return CreateExtension();
+}
+
+void __stdcall DebugExtensionUninitialize() {
+  DestroyExtension();
+  sp_debug_host = nullptr;
+  sp_data_model_manager = nullptr;
+  sp_debug_host_memory = nullptr;
+  sp_debug_host_symbols = nullptr;
+  sp_debug_host_extensibility = nullptr;
+
+  _CrtMemCheckpoint(&mem_new);
+  if (_CrtMemDifference(&mem_diff, &mem_old, &mem_new)) {
+    _CrtMemDumpStatistics(&mem_diff);
+  }
+  _CrtSetDbgFlag(original_crt_dbg_flag);
+}
+
+HRESULT __stdcall DebugExtensionCanUnload(void) {
+  if (!WRL::Module<WRL::InProc>::GetModule().Terminate()) {
+    _RPTF0(_CRT_WARN, "Failed to unload WRL\n");
+    return S_FALSE;
+  }
+  return S_OK;
+}
+
+void __stdcall DebugExtensionUnload() { return; }
+
+}  // extern "C"
diff --git a/deps/v8/tools/v8windbg/base/dbgext.def b/deps/v8/tools/v8windbg/base/dbgext.def
new file mode 100644
index 0000000000..7f32756c35
--- /dev/null
+++ b/deps/v8/tools/v8windbg/base/dbgext.def
@@ -0,0 +1,5 @@
+EXPORTS
+  DebugExtensionInitialize
+  DebugExtensionUninitialize
+  DebugExtensionCanUnload
+  DebugExtensionUnload
diff --git a/deps/v8/tools/v8windbg/base/dbgext.h b/deps/v8/tools/v8windbg/base/dbgext.h
new file mode 100644
index 0000000000..8b36a8f361
--- /dev/null
+++ b/deps/v8/tools/v8windbg/base/dbgext.h
@@ -0,0 +1,34 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_BASE_DBGEXT_H_
+#define V8_TOOLS_V8WINDBG_BASE_DBGEXT_H_
+
+#if !defined(UNICODE) || !defined(_UNICODE)
+#error Unicode not defined
+#endif
+
+#include <DbgEng.h>
+#include <DbgModel.h>
+#include <Windows.h>
+#include <crtdbg.h>
+#include <wrl/client.h>
+
+#include <string>
+
+namespace WRL = Microsoft::WRL;
+
+// Globals for use throughout the extension. (Populated on load).
+extern WRL::ComPtr<IDataModelManager> sp_data_model_manager;
+extern WRL::ComPtr<IDebugHost> sp_debug_host;
+extern WRL::ComPtr<IDebugControl5> sp_debug_control;
+extern WRL::ComPtr<IDebugHostMemory2> sp_debug_host_memory;
+extern WRL::ComPtr<IDebugHostSymbols> sp_debug_host_symbols;
+extern WRL::ComPtr<IDebugHostExtensibility> sp_debug_host_extensibility;
+
+// To be implemented by the custom extension code. (Called on load).
+HRESULT CreateExtension();
+void DestroyExtension();
+
+#endif  // V8_TOOLS_V8WINDBG_BASE_DBGEXT_H_
diff --git a/deps/v8/tools/v8windbg/base/utilities.cc b/deps/v8/tools/v8windbg/base/utilities.cc
new file mode 100644
index 0000000000..a59e95f46f
--- /dev/null
+++ b/deps/v8/tools/v8windbg/base/utilities.cc
@@ -0,0 +1,246 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/base/utilities.h"
+
+#include <comutil.h>
+#include <oleauto.h>
+
+#include <vector>
+
+namespace {
+
+HRESULT BoxObject(IDataModelManager* p_manager, IUnknown* p_object,
+                  ModelObjectKind kind, IModelObject** pp_model_object) {
+  *pp_model_object = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_UNKNOWN;
+  vt_val.punkVal = p_object;
+
+  HRESULT hr = p_manager->CreateIntrinsicObject(kind, &vt_val, pp_model_object);
+  return hr;
+}
+
+}  // namespace
+
+HRESULT CreateProperty(IDataModelManager* p_manager,
+                       IModelPropertyAccessor* p_property,
+                       IModelObject** pp_property_object) {
+  return BoxObject(p_manager, p_property, ObjectPropertyAccessor,
+                   pp_property_object);
+}
+
+HRESULT CreateMethod(IDataModelManager* p_manager, IModelMethod* p_method,
+                     IModelObject** pp_method_object) {
+  return BoxObject(p_manager, p_method, ObjectMethod, pp_method_object);
+}
+
+HRESULT UnboxProperty(IModelObject* object, IModelPropertyAccessor** result) {
+  ModelObjectKind kind = (ModelObjectKind)-1;
+  RETURN_IF_FAIL(object->GetKind(&kind));
+  if (kind != ObjectPropertyAccessor) return E_FAIL;
+  _variant_t variant;
+  RETURN_IF_FAIL(object->GetIntrinsicValue(&variant));
+  if (variant.vt != VT_UNKNOWN) return E_FAIL;
+  WRL::ComPtr<IModelPropertyAccessor> accessor;
+  RETURN_IF_FAIL(WRL::ComPtr<IUnknown>(variant.punkVal).As(&accessor));
+  *result = accessor.Detach();
+  return S_OK;
+}
+
+HRESULT CreateTypedIntrinsic(uint64_t value, IDebugHostType* type,
+                             IModelObject** result) {
+  // Figure out what kind of VARIANT we need to make.
+  IntrinsicKind kind;
+  VARTYPE carrier;
+  RETURN_IF_FAIL(type->GetIntrinsicType(&kind, &carrier));
+
+  VARIANT vt_val;
+  switch (carrier) {
+    case VT_BOOL:
+      vt_val.boolVal = value ? VARIANT_TRUE : VARIANT_FALSE;
+      break;
+    case VT_I1:
+      vt_val.cVal = static_cast<int8_t>(value);
+      break;
+    case VT_UI1:
+      vt_val.bVal = static_cast<uint8_t>(value);
+      break;
+    case VT_I2:
+      vt_val.iVal = static_cast<int16_t>(value);
+      break;
+    case VT_UI2:
+      vt_val.uiVal = static_cast<uint16_t>(value);
+      break;
+    case VT_INT:
+      vt_val.intVal = static_cast<int>(value);
+      break;
+    case VT_UINT:
+      vt_val.uintVal = static_cast<unsigned int>(value);
+      break;
+    case VT_I4:
+      vt_val.lVal = static_cast<int32_t>(value);
+      break;
+    case VT_UI4:
+      vt_val.ulVal = static_cast<uint32_t>(value);
+      break;
+    case VT_INT_PTR:
+      vt_val.llVal = static_cast<intptr_t>(value);
+      break;
+    case VT_UINT_PTR:
+      vt_val.ullVal = static_cast<uintptr_t>(value);
+      break;
+    case VT_I8:
+      vt_val.llVal = static_cast<int64_t>(value);
+      break;
+    case VT_UI8:
+      vt_val.ullVal = static_cast<uint64_t>(value);
+      break;
+    default:
+      return E_FAIL;
+  }
+  vt_val.vt = carrier;
+  return sp_data_model_manager->CreateTypedIntrinsicObject(&vt_val, type,
+                                                           result);
+}
+
+HRESULT CreateULong64(ULONG64 value, IModelObject** pp_int) {
+  HRESULT hr = S_OK;
+  *pp_int = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_UI8;
+  vt_val.ullVal = value;
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_int);
+  return hr;
+}
+
+HRESULT UnboxULong64(IModelObject* object, ULONG64* value, bool convert) {
+  ModelObjectKind kind = (ModelObjectKind)-1;
+  RETURN_IF_FAIL(object->GetKind(&kind));
+  if (kind != ObjectIntrinsic) return E_FAIL;
+  _variant_t variant;
+  RETURN_IF_FAIL(object->GetIntrinsicValue(&variant));
+  if (convert) {
+    RETURN_IF_FAIL(VariantChangeType(&variant, &variant, 0, VT_UI8));
+  }
+  if (variant.vt != VT_UI8) return E_FAIL;
+  *value = variant.ullVal;
+  return S_OK;
+}
+
+HRESULT CreateInt32(int value, IModelObject** pp_int) {
+  HRESULT hr = S_OK;
+  *pp_int = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_I4;
+  vt_val.intVal = value;
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_int);
+  return hr;
+}
+
+HRESULT CreateUInt32(uint32_t value, IModelObject** pp_int) {
+  HRESULT hr = S_OK;
+  *pp_int = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_UI4;
+  vt_val.uintVal = value;
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_int);
+  return hr;
+}
+
+HRESULT CreateBool(bool value, IModelObject** pp_val) {
+  HRESULT hr = S_OK;
+  *pp_val = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_BOOL;
+  vt_val.boolVal = value;
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_val);
+  return hr;
+}
+
+HRESULT CreateNumber(double value, IModelObject** pp_val) {
+  HRESULT hr = S_OK;
+  *pp_val = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_R8;
+  vt_val.dblVal = value;
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_val);
+  return hr;
+}
+
+HRESULT CreateString(std::u16string value, IModelObject** pp_val) {
+  HRESULT hr = S_OK;
+  *pp_val = nullptr;
+
+  VARIANT vt_val;
+  vt_val.vt = VT_BSTR;
+  vt_val.bstrVal =
+      ::SysAllocString(reinterpret_cast<const OLECHAR*>(value.c_str()));
+
+  hr = sp_data_model_manager->CreateIntrinsicObject(ObjectIntrinsic, &vt_val,
+                                                    pp_val);
+  return hr;
+}
+
+HRESULT UnboxString(IModelObject* object, BSTR* value) {
+  ModelObjectKind kind = (ModelObjectKind)-1;
+  RETURN_IF_FAIL(object->GetKind(&kind));
+  if (kind != ObjectIntrinsic) return E_FAIL;
+  _variant_t variant;
+  RETURN_IF_FAIL(object->GetIntrinsicValue(&variant));
+  if (variant.vt != VT_BSTR) return E_FAIL;
+  *value = variant.Detach().bstrVal;
+  return S_OK;
+}
+
+HRESULT GetModelAtIndex(WRL::ComPtr<IModelObject>& sp_parent,
+                        WRL::ComPtr<IModelObject>& sp_index,
+                        IModelObject** p_result) {
+  WRL::ComPtr<IIndexableConcept> sp_indexable_concept;
+  RETURN_IF_FAIL(sp_parent->GetConcept(__uuidof(IIndexableConcept),
+                                       &sp_indexable_concept, nullptr));
+
+  std::vector<IModelObject*> p_indexers{sp_index.Get()};
+  return sp_indexable_concept->GetAt(sp_parent.Get(), 1, p_indexers.data(),
+                                     p_result, nullptr);
+}
+
+HRESULT GetCurrentThread(WRL::ComPtr<IDebugHostContext>& sp_host_context,
+                         IModelObject** p_current_thread) {
+  WRL::ComPtr<IModelObject> sp_boxed_context, sp_root_namespace;
+  WRL::ComPtr<IModelObject> sp_debugger, sp_sessions, sp_processes, sp_threads;
+  WRL::ComPtr<IModelObject> sp_curr_session, sp_curr_process;
+
+  RETURN_IF_FAIL(BoxObject(sp_data_model_manager.Get(), sp_host_context.Get(),
+                           ObjectContext, &sp_boxed_context));
+  RETURN_IF_FAIL(sp_data_model_manager->GetRootNamespace(&sp_root_namespace));
+  RETURN_IF_FAIL(
+      sp_root_namespace->GetKeyValue(L"Debugger", &sp_debugger, nullptr));
+  RETURN_IF_FAIL(sp_debugger->GetKeyValue(L"Sessions", &sp_sessions, nullptr));
+  RETURN_IF_FAIL(
+      GetModelAtIndex(sp_sessions, sp_boxed_context, &sp_curr_session));
+  RETURN_IF_FAIL(
+      sp_curr_session->GetKeyValue(L"Processes", &sp_processes, nullptr));
+  RETURN_IF_FAIL(
+      GetModelAtIndex(sp_processes, sp_boxed_context, &sp_curr_process));
+  RETURN_IF_FAIL(
+      sp_curr_process->GetKeyValue(L"Threads", &sp_threads, nullptr));
+  return GetModelAtIndex(sp_threads, sp_boxed_context, p_current_thread);
+}
diff --git a/deps/v8/tools/v8windbg/base/utilities.h b/deps/v8/tools/v8windbg/base/utilities.h
new file mode 100644
index 0000000000..e26bb28780
--- /dev/null
+++ b/deps/v8/tools/v8windbg/base/utilities.h
@@ -0,0 +1,85 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_BASE_UTILITIES_H_
+#define V8_TOOLS_V8WINDBG_BASE_UTILITIES_H_
+
+#include "tools/v8windbg/base/dbgext.h"
+
+inline const wchar_t* U16ToWChar(const char16_t* p_u16) {
+  static_assert(sizeof(wchar_t) == sizeof(char16_t), "wrong wchar size");
+  return reinterpret_cast<const wchar_t*>(p_u16);
+}
+
+inline const wchar_t* U16ToWChar(std::u16string& str) {
+  return U16ToWChar(str.data());
+}
+
+#if defined(WIN32)
+inline std::u16string ConvertToU16String(std::string utf8_string) {
+  int len_chars =
+      ::MultiByteToWideChar(CP_UTF8, 0, utf8_string.c_str(), -1, nullptr, 0);
+
+  char16_t* p_buff =
+      static_cast<char16_t*>(malloc(len_chars * sizeof(char16_t)));
+
+  // On Windows wchar_t is the same a char16_t
+  static_assert(sizeof(wchar_t) == sizeof(char16_t), "wrong wchar size");
+  len_chars =
+      ::MultiByteToWideChar(CP_UTF8, 0, utf8_string.c_str(), -1,
+                            reinterpret_cast<wchar_t*>(p_buff), len_chars);
+  std::u16string result{p_buff};
+  free(p_buff);
+
+  return result;
+}
+#else
+#error String encoding conversion must be provided for the target platform.
+#endif
+
+HRESULT CreateProperty(IDataModelManager* p_manager,
+                       IModelPropertyAccessor* p_property,
+                       IModelObject** pp_property_object);
+
+HRESULT CreateMethod(IDataModelManager* p_manager, IModelMethod* p_method,
+                     IModelObject** pp_method_object);
+
+HRESULT UnboxProperty(IModelObject* object, IModelPropertyAccessor** result);
+
+HRESULT CreateTypedIntrinsic(uint64_t value, IDebugHostType* type,
+                             IModelObject** result);
+
+HRESULT CreateULong64(ULONG64 value, IModelObject** pp_int);
+
+HRESULT UnboxULong64(IModelObject* object, ULONG64* value,
+                     bool convert = false);
+
+HRESULT CreateInt32(int value, IModelObject** pp_int);
+
+HRESULT CreateUInt32(uint32_t value, IModelObject** pp_int);
+
+HRESULT CreateBool(bool value, IModelObject** pp_val);
+
+HRESULT CreateNumber(double value, IModelObject** pp_val);
+
+HRESULT CreateString(std::u16string value, IModelObject** pp_val);
+
+HRESULT UnboxString(IModelObject* object, BSTR* value);
+
+HRESULT GetModelAtIndex(WRL::ComPtr<IModelObject>& sp_parent,
+                        WRL::ComPtr<IModelObject>& sp_index,
+                        IModelObject** p_result);
+
+HRESULT GetCurrentThread(WRL::ComPtr<IDebugHostContext>& sp_host_context,
+                         IModelObject** p_current_thread);
+
+#define RETURN_IF_FAIL(expression) \
+  do {                             \
+    HRESULT hr = expression;       \
+    if (FAILED(hr)) {              \
+      return hr;                   \
+    }                              \
+  } while (false)
+
+#endif  // V8_TOOLS_V8WINDBG_BASE_UTILITIES_H_
diff --git a/deps/v8/tools/v8windbg/copy-prereqs.py b/deps/v8/tools/v8windbg/copy-prereqs.py
new file mode 100644
index 0000000000..c13efe6582
--- /dev/null
+++ b/deps/v8/tools/v8windbg/copy-prereqs.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+# Copyright 2020 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""This program copies dbgeng.dll from the Windows SDK to the output directory,
+so that we can test v8windbg. (The version of dbgeng.dll in system32, which
+would be loaded otherwise, is insufficient.)
+Arguments:
+1. The directory that contains vs_toolchain.py
+2. The directory to copy to
+3. The cpu type for this build
+"""
+
+import sys
+import os
+
+vs_toolchain_dir, target_dir, target_cpu = sys.argv[1:]
+
+sys.path.insert(0, vs_toolchain_dir)
+import vs_toolchain
+
+def CopyDebuggerFile(debug_file):
+  win_sdk_dir = vs_toolchain.SetEnvironmentAndGetSDKDir()
+  if not win_sdk_dir:
+    return
+
+  full_path = os.path.join(win_sdk_dir, 'Debuggers', target_cpu, debug_file)
+  if not os.path.exists(full_path):
+    return
+
+  target_path = os.path.join(target_dir, debug_file)
+  vs_toolchain._CopyRuntimeImpl(target_path, full_path, verbose=False)
+
+  # Ninja expects the file's timestamp to be newer than this script.
+  os.utime(target_path, None)
+
+CopyDebuggerFile('dbgeng.dll')
diff --git a/deps/v8/tools/v8windbg/src/cur-isolate.cc b/deps/v8/tools/v8windbg/src/cur-isolate.cc
new file mode 100644
index 0000000000..f39098f686
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/cur-isolate.cc
@@ -0,0 +1,94 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/cur-isolate.h"
+
+HRESULT GetIsolateKey(WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                      int* isolate_key) {
+  auto sp_v8_module = Extension::Current()->GetV8Module(sp_ctx);
+  if (sp_v8_module == nullptr) return E_FAIL;
+
+  WRL::ComPtr<IDebugHostSymbol> sp_isolate_sym;
+  RETURN_IF_FAIL(sp_v8_module->FindSymbolByName(kIsolateKey, &sp_isolate_sym));
+  SymbolKind kind;
+  RETURN_IF_FAIL(sp_isolate_sym->GetSymbolKind(&kind));
+  if (kind != SymbolData) return E_FAIL;
+  WRL::ComPtr<IDebugHostData> sp_isolate_key_data;
+  RETURN_IF_FAIL(sp_isolate_sym.As(&sp_isolate_key_data));
+  Location loc;
+  RETURN_IF_FAIL(sp_isolate_key_data->GetLocation(&loc));
+  ULONG64 bytes_read;
+  RETURN_IF_FAIL(sp_debug_host_memory->ReadBytes(
+      sp_ctx.Get(), loc, isolate_key, sizeof(isolate_key), &bytes_read));
+  return S_OK;
+}
+
+HRESULT GetCurrentIsolate(WRL::ComPtr<IModelObject>& sp_result) {
+  sp_result = nullptr;
+
+  // Get the current context
+  WRL::ComPtr<IDebugHostContext> sp_host_context;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_host_context));
+
+  WRL::ComPtr<IModelObject> sp_curr_thread;
+  RETURN_IF_FAIL(GetCurrentThread(sp_host_context, &sp_curr_thread));
+
+  WRL::ComPtr<IModelObject> sp_environment, sp_environment_block;
+  WRL::ComPtr<IModelObject> sp_tls_slots, sp_slot_index, sp_isolate_ptr;
+  RETURN_IF_FAIL(
+      sp_curr_thread->GetKeyValue(L"Environment", &sp_environment, nullptr));
+
+  RETURN_IF_FAIL(sp_environment->GetKeyValue(L"EnvironmentBlock",
+                                             &sp_environment_block, nullptr));
+
+  // EnvironmentBlock and TlsSlots are native types (TypeUDT) and thus
+  // GetRawValue rather than GetKeyValue should be used to get field (member)
+  // values.
+  ModelObjectKind kind;
+  RETURN_IF_FAIL(sp_environment_block->GetKind(&kind));
+  if (kind != ModelObjectKind::ObjectTargetObject) return E_FAIL;
+
+  RETURN_IF_FAIL(sp_environment_block->GetRawValue(SymbolField, L"TlsSlots", 0,
+                                                   &sp_tls_slots));
+
+  int isolate_key = -1;
+  RETURN_IF_FAIL(GetIsolateKey(sp_host_context, &isolate_key));
+  RETURN_IF_FAIL(CreateInt32(isolate_key, &sp_slot_index));
+
+  RETURN_IF_FAIL(GetModelAtIndex(sp_tls_slots, sp_slot_index, &sp_isolate_ptr));
+
+  // Need to dereference the slot and then get the address held in it
+  WRL::ComPtr<IModelObject> sp_dereferenced_slot;
+  RETURN_IF_FAIL(sp_isolate_ptr->Dereference(&sp_dereferenced_slot));
+
+  uint64_t isolate_ptr;
+  RETURN_IF_FAIL(UnboxULong64(sp_dereferenced_slot.Get(), &isolate_ptr));
+  Location isolate_addr{isolate_ptr};
+
+  // If we got the isolate_key OK, then must have the V8 module loaded
+  // Get the internal Isolate type from it
+  WRL::ComPtr<IDebugHostType> sp_isolate_type, sp_isolate_ptr_type;
+  RETURN_IF_FAIL(Extension::Current()
+                     ->GetV8Module(sp_host_context)
+                     ->FindTypeByName(kIsolate, &sp_isolate_type));
+  RETURN_IF_FAIL(
+      sp_isolate_type->CreatePointerTo(PointerStandard, &sp_isolate_ptr_type));
+
+  RETURN_IF_FAIL(sp_data_model_manager->CreateTypedObject(
+      sp_host_context.Get(), isolate_addr, sp_isolate_type.Get(), &sp_result));
+
+  return S_OK;
+}
+
+IFACEMETHODIMP CurrIsolateAlias::Call(IModelObject* p_context_object,
+                                      ULONG64 arg_count,
+                                      IModelObject** pp_arguments,
+                                      IModelObject** pp_result,
+                                      IKeyStore** pp_metadata) noexcept {
+  *pp_result = nullptr;
+  WRL::ComPtr<IModelObject> sp_result;
+  RETURN_IF_FAIL(GetCurrentIsolate(sp_result));
+  *pp_result = sp_result.Detach();
+  return S_OK;
+}
diff --git a/deps/v8/tools/v8windbg/src/cur-isolate.h b/deps/v8/tools/v8windbg/src/cur-isolate.h
new file mode 100644
index 0000000000..2be24ce7fd
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/cur-isolate.h
@@ -0,0 +1,34 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_CUR_ISOLATE_H_
+#define V8_TOOLS_V8WINDBG_SRC_CUR_ISOLATE_H_
+
+#include <crtdbg.h>
+#include <wrl/implements.h>
+
+#include <string>
+#include <vector>
+
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+HRESULT GetCurrentIsolate(WRL::ComPtr<IModelObject>& sp_result);
+
+constexpr wchar_t kIsolateKey[] = L"isolate_key_";
+constexpr wchar_t kIsolate[] = L"v8::internal::Isolate";
+
+class CurrIsolateAlias
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelMethod> {
+ public:
+  IFACEMETHOD(Call)
+  (IModelObject* p_context_object, ULONG64 arg_count,
+   _In_reads_(arg_count) IModelObject** pp_arguments, IModelObject** pp_result,
+   IKeyStore** pp_metadata);
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_CUR_ISOLATE_H_
diff --git a/deps/v8/tools/v8windbg/src/list-chunks.cc b/deps/v8/tools/v8windbg/src/list-chunks.cc
new file mode 100644
index 0000000000..90b3ff6af6
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/list-chunks.cc
@@ -0,0 +1,238 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/list-chunks.h"
+
+#include "tools/v8windbg/src/cur-isolate.h"
+
+// v8windbg!ListChunksAlias::Call
+IFACEMETHODIMP ListChunksAlias::Call(IModelObject* p_context_object,
+                                     ULONG64 arg_count,
+                                     _In_reads_(arg_count)
+                                         IModelObject** pp_arguments,
+                                     IModelObject** pp_result,
+                                     IKeyStore** pp_metadata) noexcept {
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_ctx));
+
+  WRL::ComPtr<IModelObject> result;
+  RETURN_IF_FAIL(
+      sp_data_model_manager->CreateSyntheticObject(sp_ctx.Get(), &result));
+
+  auto sp_iterator{WRL::Make<MemoryChunks>()};
+
+  RETURN_IF_FAIL(result->SetConcept(
+      __uuidof(IIndexableConcept),
+      static_cast<IIndexableConcept*>(sp_iterator.Get()), nullptr));
+  RETURN_IF_FAIL(result->SetConcept(
+      __uuidof(IIterableConcept),
+      static_cast<IIterableConcept*>(sp_iterator.Get()), nullptr));
+
+  *pp_result = result.Detach();
+  if (pp_metadata) {
+    *pp_metadata = nullptr;
+  }
+  return S_OK;
+}
+
+ChunkData::ChunkData() = default;
+ChunkData::~ChunkData() = default;
+ChunkData::ChunkData(const ChunkData&) = default;
+ChunkData::ChunkData(ChunkData&&) = default;
+ChunkData& ChunkData::operator=(const ChunkData&) = default;
+ChunkData& ChunkData::operator=(ChunkData&&) = default;
+
+MemoryChunkIterator::MemoryChunkIterator(
+    WRL::ComPtr<IDebugHostContext>& host_context)
+    : sp_ctx_(host_context) {}
+MemoryChunkIterator::~MemoryChunkIterator() = default;
+
+HRESULT MemoryChunkIterator::PopulateChunkData() {
+  WRL::ComPtr<IModelObject> sp_isolate, sp_heap, sp_space;
+  chunks_.clear();
+
+  RETURN_IF_FAIL(GetCurrentIsolate(sp_isolate));
+
+  RETURN_IF_FAIL(
+      sp_isolate->GetRawValue(SymbolField, L"heap_", RawSearchNone, &sp_heap));
+  RETURN_IF_FAIL(
+      sp_heap->GetRawValue(SymbolField, L"space_", RawSearchNone, &sp_space));
+
+  WRL::ComPtr<IDebugHostType> sp_space_type;
+  RETURN_IF_FAIL(sp_space->GetTypeInfo(&sp_space_type));
+
+  // Iterate over the array of Space pointers
+  WRL::ComPtr<IIterableConcept> sp_iterable;
+  RETURN_IF_FAIL(
+      sp_space->GetConcept(__uuidof(IIterableConcept), &sp_iterable, nullptr));
+
+  WRL::ComPtr<IModelIterator> sp_space_iterator;
+  RETURN_IF_FAIL(sp_iterable->GetIterator(sp_space.Get(), &sp_space_iterator));
+
+  // Loop through all the spaces in the array
+  WRL::ComPtr<IModelObject> sp_space_ptr;
+  while (sp_space_iterator->GetNext(&sp_space_ptr, 0, nullptr, nullptr) !=
+         E_BOUNDS) {
+    // Should have gotten a "v8::internal::Space *". Dereference, then get field
+    // "memory_chunk_list_" [Type: v8::base::List<v8::internal::MemoryChunk>]
+    WRL::ComPtr<IModelObject> sp_space, sp_chunk_list, sp_mem_chunk_ptr,
+        sp_mem_chunk;
+    RETURN_IF_FAIL(sp_space_ptr->Dereference(&sp_space));
+    RETURN_IF_FAIL(sp_space->GetRawValue(SymbolField, L"memory_chunk_list_",
+                                         RawSearchNone, &sp_chunk_list));
+
+    // Then get field "front_" [Type: v8::internal::MemoryChunk *]
+    RETURN_IF_FAIL(sp_chunk_list->GetRawValue(
+        SymbolField, L"front_", RawSearchNone, &sp_mem_chunk_ptr));
+
+    // Loop here on the list of MemoryChunks for the space
+    while (true) {
+      // See if it is a nullptr (i.e. no chunks in this space)
+      uint64_t front_val;
+      RETURN_IF_FAIL(
+          UnboxULong64(sp_mem_chunk_ptr.Get(), &front_val, true /*convert*/));
+      if (front_val == 0) {
+        break;
+      }
+
+      // Dereference and get fields "area_start_" and "area_end_" (both uint64)
+      RETURN_IF_FAIL(sp_mem_chunk_ptr->Dereference(&sp_mem_chunk));
+
+      WRL::ComPtr<IModelObject> sp_start, sp_end;
+      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"area_start_",
+                                               RawSearchNone, &sp_start));
+      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"area_end_",
+                                               RawSearchNone, &sp_end));
+
+      ChunkData chunk_entry;
+      chunk_entry.area_start = sp_start;
+      chunk_entry.area_end = sp_end;
+      chunk_entry.space = sp_space;
+      chunks_.push_back(chunk_entry);
+
+      // Follow the list_node_.next_ to the next memory chunk
+      WRL::ComPtr<IModelObject> sp_list_node;
+      RETURN_IF_FAIL(sp_mem_chunk->GetRawValue(SymbolField, L"list_node_",
+                                               RawSearchNone, &sp_list_node));
+
+      sp_mem_chunk_ptr = nullptr;
+      sp_mem_chunk = nullptr;
+      RETURN_IF_FAIL(sp_list_node->GetRawValue(
+          SymbolField, L"next_", RawSearchNone, &sp_mem_chunk_ptr));
+      // Top of the loop will check if this is a nullptr and exit if so
+    }
+    sp_space_ptr = nullptr;
+  }
+
+  return S_OK;
+}
+
+IFACEMETHODIMP MemoryChunkIterator::Reset() noexcept {
+  position_ = 0;
+  return S_OK;
+}
+
+IFACEMETHODIMP MemoryChunkIterator::GetNext(IModelObject** object,
+                                            ULONG64 dimensions,
+                                            IModelObject** indexers,
+                                            IKeyStore** metadata) noexcept {
+  if (dimensions > 1) return E_INVALIDARG;
+
+  if (position_ == 0) {
+    RETURN_IF_FAIL(PopulateChunkData());
+  }
+
+  if (metadata != nullptr) *metadata = nullptr;
+
+  WRL::ComPtr<IModelObject> sp_index, sp_value;
+
+  if (dimensions == 1) {
+    RETURN_IF_FAIL(CreateULong64(position_, &sp_index));
+  }
+
+  RETURN_IF_FAIL(GetAt(position_, &sp_value));
+
+  // Now update counter and transfer ownership of results, because nothing can
+  // fail from this point onward.
+  ++position_;
+  if (dimensions == 1) {
+    *indexers = sp_index.Detach();
+  }
+  *object = sp_value.Detach();
+  return S_OK;
+}
+
+HRESULT MemoryChunkIterator::GetAt(uint64_t index,
+                                   IModelObject** result) const {
+  if (index >= chunks_.size()) return E_BOUNDS;
+
+  // Create the synthetic object representing the chunk here
+  const ChunkData& curr_chunk = chunks_.at(index);
+  WRL::ComPtr<IModelObject> sp_value;
+  RETURN_IF_FAIL(
+      sp_data_model_manager->CreateSyntheticObject(sp_ctx_.Get(), &sp_value));
+  RETURN_IF_FAIL(
+      sp_value->SetKey(L"area_start", curr_chunk.area_start.Get(), nullptr));
+  RETURN_IF_FAIL(
+      sp_value->SetKey(L"area_end", curr_chunk.area_end.Get(), nullptr));
+  RETURN_IF_FAIL(sp_value->SetKey(L"space", curr_chunk.space.Get(), nullptr));
+
+  *result = sp_value.Detach();
+  return S_OK;
+}
+
+MemoryChunks::MemoryChunks() = default;
+MemoryChunks::~MemoryChunks() = default;
+
+IFACEMETHODIMP MemoryChunks::GetDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP MemoryChunks::GetAt(IModelObject* context_object,
+                                   ULONG64 indexer_count,
+                                   IModelObject** indexers,
+                                   IModelObject** object,
+                                   IKeyStore** metadata) noexcept {
+  if (indexer_count != 1) return E_INVALIDARG;
+  if (metadata != nullptr) *metadata = nullptr;
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+
+  // This should be instantiated once for each synthetic object returned,
+  // so should be able to cache/reuse an iterator
+  if (opt_chunks_ == nullptr) {
+    opt_chunks_ = WRL::Make<MemoryChunkIterator>(sp_ctx);
+    _ASSERT(opt_chunks_ != nullptr);
+    RETURN_IF_FAIL(opt_chunks_->PopulateChunkData());
+  }
+
+  uint64_t index;
+  RETURN_IF_FAIL(UnboxULong64(indexers[0], &index, true /*convert*/));
+
+  return opt_chunks_->GetAt(index, object);
+}
+
+IFACEMETHODIMP MemoryChunks::SetAt(IModelObject* context_object,
+                                   ULONG64 indexer_count,
+                                   IModelObject** indexers,
+                                   IModelObject* value) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP MemoryChunks::GetDefaultIndexDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP MemoryChunks::GetIterator(IModelObject* context_object,
+                                         IModelIterator** iterator) noexcept {
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+  auto sp_memory_iterator{WRL::Make<MemoryChunkIterator>(sp_ctx)};
+  *iterator = sp_memory_iterator.Detach();
+  return S_OK;
+}
diff --git a/deps/v8/tools/v8windbg/src/list-chunks.h b/deps/v8/tools/v8windbg/src/list-chunks.h
new file mode 100644
index 0000000000..10eec100d1
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/list-chunks.h
@@ -0,0 +1,100 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
+#define V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
+
+#include <crtdbg.h>
+#include <wrl/implements.h>
+
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "src/base/optional.h"
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+class ListChunksAlias
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelMethod> {
+ public:
+  IFACEMETHOD(Call)
+  (IModelObject* p_context_object, ULONG64 arg_count,
+   _In_reads_(arg_count) IModelObject** pp_arguments, IModelObject** pp_result,
+   IKeyStore** pp_metadata);
+};
+
+struct ChunkData {
+  ChunkData();
+  ~ChunkData();
+  ChunkData(const ChunkData&);
+  ChunkData(ChunkData&&);
+  ChunkData& operator=(const ChunkData&);
+  ChunkData& operator=(ChunkData&&);
+  WRL::ComPtr<IModelObject> area_start;
+  WRL::ComPtr<IModelObject> area_end;
+  WRL::ComPtr<IModelObject> space;
+};
+
+class MemoryChunkIterator
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelIterator> {
+ public:
+  MemoryChunkIterator(WRL::ComPtr<IDebugHostContext>& host_context);
+  ~MemoryChunkIterator() override;
+
+  HRESULT PopulateChunkData();
+
+  IFACEMETHOD(Reset)();
+
+  IFACEMETHOD(GetNext)
+  (IModelObject** object, ULONG64 dimensions, IModelObject** indexers,
+   IKeyStore** metadata);
+
+  const std::vector<ChunkData>& GetChunks() const { return chunks_; }
+
+  HRESULT GetAt(uint64_t index, IModelObject** result) const;
+
+ private:
+  ULONG position_ = 0;
+  std::vector<ChunkData> chunks_;
+  WRL::ComPtr<IDebugHostContext> sp_ctx_;
+};
+
+class MemoryChunks
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IIndexableConcept, IIterableConcept> {
+ public:
+  MemoryChunks();
+  ~MemoryChunks() override;
+
+  // IIndexableConcept members
+  IFACEMETHOD(GetDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  IFACEMETHOD(GetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   IModelObject** object, IKeyStore** metadata);
+
+  IFACEMETHOD(SetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   IModelObject* value);
+
+  // IIterableConcept
+  IFACEMETHOD(GetDefaultIndexDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  IFACEMETHOD(GetIterator)
+  (IModelObject* context_object, IModelIterator** iterator);
+
+ private:
+  WRL::ComPtr<MemoryChunkIterator> opt_chunks_;
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_LIST_CHUNKS_H_
diff --git a/deps/v8/tools/v8windbg/src/local-variables.cc b/deps/v8/tools/v8windbg/src/local-variables.cc
new file mode 100644
index 0000000000..20814cf28a
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/local-variables.cc
@@ -0,0 +1,120 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/local-variables.h"
+
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+V8LocalVariables::V8LocalVariables(WRL::ComPtr<IModelPropertyAccessor> original,
+                                   bool is_parameters)
+    : original_(original), is_parameters_(is_parameters) {}
+V8LocalVariables::~V8LocalVariables() = default;
+
+IFACEMETHODIMP V8LocalVariables::GetValue(PCWSTR key, IModelObject* context,
+                                          IModelObject** value) noexcept {
+  // See if the frame can fetch locals based on symbols. If so, it's a normal
+  // C++ frame, so we can be done.
+  HRESULT original_hr = original_->GetValue(key, context, value);
+  if (SUCCEEDED(original_hr)) return original_hr;
+
+  // Next, try to find out about the instruction pointer. If it is within the V8
+  // module, or points to unknown space outside a module (generated code), then
+  // we're interested. Otherwise, we have nothing useful to do.
+  WRL::ComPtr<IModelObject> attributes;
+  RETURN_IF_FAIL(context->GetKeyValue(L"Attributes", &attributes, nullptr));
+  WRL::ComPtr<IModelObject> boxed_instruction_offset;
+  RETURN_IF_FAIL(attributes->GetKeyValue(L"InstructionOffset",
+                                         &boxed_instruction_offset, nullptr));
+  ULONG64 instruction_offset{};
+  RETURN_IF_FAIL(
+      UnboxULong64(boxed_instruction_offset.Get(), &instruction_offset));
+  WRL::ComPtr<IDebugHostSymbols> symbols;
+  RETURN_IF_FAIL(sp_debug_host.As(&symbols));
+  WRL::ComPtr<IDebugHostContext> host_context;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&host_context));
+  WRL::ComPtr<IDebugHostModule> module;
+  if (SUCCEEDED(symbols->FindModuleByLocation(host_context.Get(),
+                                              instruction_offset, &module))) {
+    Location module_base;
+    RETURN_IF_FAIL(module->GetBaseLocation(&module_base));
+    WRL::ComPtr<IDebugHostModule> v8_module =
+        Extension::Current()->GetV8Module(host_context);
+    if (v8_module == nullptr) {
+      // Anything in a module must not be in the V8 module if the V8 module
+      // doesn't exist.
+      return original_hr;
+    }
+    Location v8_base;
+    RETURN_IF_FAIL(v8_module->GetBaseLocation(&v8_base));
+    if (module_base != v8_base) {
+      // It's in a module, but not the one that contains V8.
+      return original_hr;
+    }
+  }
+
+  // Initialize an empty result object.
+  WRL::ComPtr<IModelObject> result;
+  RETURN_IF_FAIL(sp_data_model_manager->CreateSyntheticObject(
+      host_context.Get(), &result));
+  WRL::ComPtr<IModelObject> parent_model;
+  RETURN_IF_FAIL(sp_data_model_manager->AcquireNamedModel(
+      is_parameters_ ? L"Debugger.Models.Parameters"
+                     : L"Debugger.Models.LocalVariables",
+      &parent_model));
+  RETURN_IF_FAIL(result->AddParentModel(parent_model.Get(), /*context=*/nullptr,
+                                        /*override=*/false));
+
+  if (is_parameters_) {
+    // We're not actually adding any parameters data yet; we just need it to not
+    // fail so that the locals pane displays the LocalVariables. The locals pane
+    // displays nothing if getting either LocalVariables or Parameters fails.
+    *value = result.Detach();
+    return S_OK;
+  }
+
+  // Get the stack and frame pointers for the current frame.
+  WRL::ComPtr<IModelObject> boxed_stack_offset;
+  RETURN_IF_FAIL(
+      attributes->GetKeyValue(L"StackOffset", &boxed_stack_offset, nullptr));
+  ULONG64 stack_offset{};
+  RETURN_IF_FAIL(UnboxULong64(boxed_stack_offset.Get(), &stack_offset));
+  WRL::ComPtr<IModelObject> boxed_frame_offset;
+  RETURN_IF_FAIL(
+      attributes->GetKeyValue(L"FrameOffset", &boxed_frame_offset, nullptr));
+  ULONG64 frame_offset{};
+  RETURN_IF_FAIL(UnboxULong64(boxed_frame_offset.Get(), &frame_offset));
+
+  // Eventually v8_debug_helper will provide some help here, but for now, just
+  // provide the option to view the whole stack frame as tagged data. It can
+  // be somewhat useful.
+  WRL::ComPtr<IDebugHostType> object_type =
+      Extension::Current()->GetV8ObjectType(host_context);
+  if (object_type == nullptr) {
+    // There's nothing useful to do if we can't find the symbol for
+    // v8::internal::Object.
+    return original_hr;
+  }
+  ULONG64 object_size{};
+  RETURN_IF_FAIL(object_type->GetSize(&object_size));
+  ULONG64 num_objects = (frame_offset - stack_offset) / object_size;
+  ArrayDimension dimensions[] = {
+      {/*start=*/0, /*length=*/num_objects, /*stride=*/object_size}};
+  WRL::ComPtr<IDebugHostType> object_array_type;
+  RETURN_IF_FAIL(object_type->CreateArrayOf(/*dimensions=*/1, dimensions,
+                                            &object_array_type));
+  WRL::ComPtr<IModelObject> array;
+  RETURN_IF_FAIL(sp_data_model_manager->CreateTypedObject(
+      host_context.Get(), stack_offset, object_array_type.Get(), &array));
+  RETURN_IF_FAIL(
+      result->SetKey(L"memory interpreted as Objects", array.Get(), nullptr));
+
+  *value = result.Detach();
+  return S_OK;
+}
+
+IFACEMETHODIMP V8LocalVariables::SetValue(PCWSTR key, IModelObject* context,
+                                          IModelObject* value) noexcept {
+  return E_NOTIMPL;
+}
diff --git a/deps/v8/tools/v8windbg/src/local-variables.h b/deps/v8/tools/v8windbg/src/local-variables.h
new file mode 100644
index 0000000000..169a93a578
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/local-variables.h
@@ -0,0 +1,36 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_LOCAL_VARIABLES_H_
+#define V8_TOOLS_V8WINDBG_SRC_LOCAL_VARIABLES_H_
+
+#include <comutil.h>
+#include <wrl/implements.h>
+
+#include "tools/v8windbg/base/dbgext.h"
+
+// An implementation of the property accessor for the "LocalVariables" or
+// "Parameters" property on Debugger.Models.StackFrame. This allows us to modify
+// the variables shown in each frame.
+class V8LocalVariables
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelPropertyAccessor> {
+ public:
+  V8LocalVariables(WRL::ComPtr<IModelPropertyAccessor> original,
+                   bool is_parameters);
+  ~V8LocalVariables() override;
+
+  IFACEMETHOD(GetValue)
+  (PCWSTR key, IModelObject* context, IModelObject** value);
+  IFACEMETHOD(SetValue)(PCWSTR key, IModelObject* context, IModelObject* value);
+
+ private:
+  // The built-in accessor which we are overriding.
+  WRL::ComPtr<IModelPropertyAccessor> original_;
+  // Whether this is for Parameters rather than LocalVariables.
+  bool is_parameters_;
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_LOCAL_VARIABLES_H_
diff --git a/deps/v8/tools/v8windbg/src/object-inspection.cc b/deps/v8/tools/v8windbg/src/object-inspection.cc
new file mode 100644
index 0000000000..ce0370a697
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/object-inspection.cc
@@ -0,0 +1,622 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/object-inspection.h"
+
+#include "src/flags/flags.h"
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+V8CachedObject::V8CachedObject(Location location,
+                               std::string uncompressed_type_name,
+                               WRL::ComPtr<IDebugHostContext> context,
+                               bool is_compressed)
+    : location_(std::move(location)),
+      uncompressed_type_name_(std::move(uncompressed_type_name)),
+      context_(std::move(context)),
+      is_compressed_(is_compressed) {}
+HRESULT V8CachedObject::Create(IModelObject* p_v8_object_instance,
+                               IV8CachedObject** result) {
+  Location location;
+  RETURN_IF_FAIL(p_v8_object_instance->GetLocation(&location));
+
+  WRL::ComPtr<IDebugHostContext> context;
+  RETURN_IF_FAIL(p_v8_object_instance->GetContext(&context));
+
+  // If the object is of type v8::internal::TaggedValue, and this build uses
+  // compressed pointers, then the value is compressed. Other types such as
+  // v8::internal::Object represent uncompressed tagged values.
+  WRL::ComPtr<IDebugHostType> sp_type;
+  _bstr_t type_name;
+  bool is_compressed =
+      COMPRESS_POINTERS_BOOL &&
+      SUCCEEDED(p_v8_object_instance->GetTypeInfo(&sp_type)) &&
+      SUCCEEDED(sp_type->GetName(type_name.GetAddress())) &&
+      static_cast<const char*>(type_name) == std::string(kTaggedValue);
+
+  const char* uncompressed_type_name =
+      is_compressed ? kObject : static_cast<const char*>(type_name);
+
+  *result = WRL::Make<V8CachedObject>(location, uncompressed_type_name, context,
+                                      is_compressed)
+                .Detach();
+  return S_OK;
+}
+V8CachedObject::V8CachedObject(V8HeapObject heap_object)
+    : heap_object_(std::move(heap_object)), heap_object_initialized_(true) {}
+
+V8CachedObject::~V8CachedObject() = default;
+
+IFACEMETHODIMP V8CachedObject::GetCachedV8HeapObject(
+    V8HeapObject** pp_heap_object) noexcept {
+  if (!heap_object_initialized_) {
+    heap_object_initialized_ = true;
+    uint64_t tagged_ptr = 0;
+    uint64_t bytes_read;
+    HRESULT hr = sp_debug_host_memory->ReadBytes(
+        context_.Get(), location_, reinterpret_cast<void*>(&tagged_ptr),
+        is_compressed_ ? i::kTaggedSize : sizeof(void*), &bytes_read);
+    // S_FALSE can be returned if fewer bytes were read than were requested. We
+    // need all of the bytes, so check for S_OK.
+    if (hr != S_OK) {
+      std::stringstream message;
+      message << "Unable to read memory";
+      if (location_.IsVirtualAddress()) {
+        message << " at 0x" << std::hex << location_.GetOffset();
+      }
+      heap_object_.friendly_name = ConvertToU16String(message.str());
+    } else {
+      if (is_compressed_)
+        tagged_ptr = ExpandCompressedPointer(static_cast<uint32_t>(tagged_ptr));
+      heap_object_ =
+          ::GetHeapObject(context_, tagged_ptr, location_.GetOffset(),
+                          uncompressed_type_name_.c_str(), is_compressed_);
+    }
+  }
+  *pp_heap_object = &this->heap_object_;
+  return S_OK;
+}
+
+IndexedFieldData::IndexedFieldData(Property property)
+    : property_(std::move(property)) {}
+
+IndexedFieldData::~IndexedFieldData() = default;
+
+IFACEMETHODIMP IndexedFieldData::GetProperty(Property** property) noexcept {
+  if (!property) return E_POINTER;
+  *property = &this->property_;
+  return S_OK;
+}
+
+V8ObjectKeyEnumerator::V8ObjectKeyEnumerator(
+    WRL::ComPtr<IV8CachedObject>& v8_cached_object)
+    : sp_v8_cached_object_{v8_cached_object} {}
+V8ObjectKeyEnumerator::~V8ObjectKeyEnumerator() = default;
+
+IFACEMETHODIMP V8ObjectKeyEnumerator::Reset() noexcept {
+  index_ = 0;
+  return S_OK;
+}
+
+IFACEMETHODIMP V8ObjectKeyEnumerator::GetNext(BSTR* key, IModelObject** value,
+                                              IKeyStore** metadata) noexcept {
+  V8HeapObject* p_v8_heap_object;
+  sp_v8_cached_object_->GetCachedV8HeapObject(&p_v8_heap_object);
+
+  if (static_cast<size_t>(index_) >= p_v8_heap_object->properties.size())
+    return E_BOUNDS;
+
+  auto* name_ptr = p_v8_heap_object->properties[index_].name.c_str();
+  *key = ::SysAllocString(U16ToWChar(name_ptr));
+  ++index_;
+  return S_OK;
+}
+
+IFACEMETHODIMP V8LocalDataModel::InitializeObject(
+    IModelObject* model_object,
+    IDebugHostTypeSignature* matching_type_signature,
+    IDebugHostSymbolEnumerator* wildcard_matches) noexcept {
+  return S_OK;
+}
+
+IFACEMETHODIMP V8LocalDataModel::GetName(BSTR* model_name) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::InitializeObject(
+    IModelObject* model_object,
+    IDebugHostTypeSignature* matching_type_signature,
+    IDebugHostSymbolEnumerator* wildcard_matches) noexcept {
+  return S_OK;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::GetName(BSTR* model_name) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::ToDisplayString(
+    IModelObject* context_object, IKeyStore* metadata,
+    BSTR* display_string) noexcept {
+  WRL::ComPtr<IV8CachedObject> sp_v8_cached_object;
+  RETURN_IF_FAIL(GetCachedObject(context_object, &sp_v8_cached_object));
+  V8HeapObject* p_v8_heap_object;
+  RETURN_IF_FAIL(sp_v8_cached_object->GetCachedV8HeapObject(&p_v8_heap_object));
+  *display_string = ::SysAllocString(
+      reinterpret_cast<const wchar_t*>(p_v8_heap_object->friendly_name.data()));
+  return S_OK;
+}
+
+namespace {
+
+// Creates a synthetic object, attaches a parent model, and sets the context
+// object for that parent data model. Caller is responsible for ensuring that
+// the parent model's Concepts have been initialized correctly and that the
+// data model context is of an appropriate type for the parent model.
+HRESULT CreateSyntheticObjectWithParentAndDataContext(
+    IDebugHostContext* ctx, IModelObject* parent_model, IUnknown* data_context,
+    IModelObject** result) {
+  WRL::ComPtr<IModelObject> value;
+  RETURN_IF_FAIL(sp_data_model_manager->CreateSyntheticObject(ctx, &value));
+  RETURN_IF_FAIL(
+      value->AddParentModel(parent_model, nullptr, true /*override*/));
+  RETURN_IF_FAIL(value->SetContextForDataModel(parent_model, data_context));
+  *result = value.Detach();
+  return S_OK;
+}
+
+// Creates an IModelObject for a V8 object whose value is represented by the
+// data in cached_object. This is an alternative to  CreateTypedObject for
+// particularly complex cases (compressed values and those that don't exist
+// anywhere in memory).
+HRESULT CreateSyntheticObjectForV8Object(IDebugHostContext* ctx,
+                                         V8CachedObject* cached_object,
+                                         IModelObject** result) {
+  // Explicitly add the parent model and data context. On a plain typed object,
+  // the parent model would be attached automatically because we registered for
+  // a matching type signature, and the data context would be set during
+  // V8ObjectDataModel::GetCachedObject.
+  return CreateSyntheticObjectWithParentAndDataContext(
+      ctx, Extension::Current()->GetObjectDataModel(), cached_object, result);
+}
+
+// Creates an IModelObject to represent a field that is not a struct or array.
+HRESULT GetModelForBasicField(const uint64_t address,
+                              const std::u16string& type_name,
+                              const std::string& uncompressed_type_name,
+                              WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                              IModelObject** result) {
+  if (type_name == ConvertToU16String(uncompressed_type_name)) {
+    // For untagged and uncompressed tagged fields, create an IModelObject
+    // representing a normal native data type.
+    WRL::ComPtr<IDebugHostType> type =
+        Extension::Current()->GetTypeFromV8Module(sp_ctx, type_name.c_str());
+    if (type == nullptr) return E_FAIL;
+    return sp_data_model_manager->CreateTypedObject(
+        sp_ctx.Get(), Location{address}, type.Get(), result);
+  }
+
+  // For compressed tagged fields, we need to do something a little more
+  // complicated. We could just use CreateTypedObject with the type
+  // v8::internal::TaggedValue, but then we'd sacrifice any other data
+  // that we've learned about the field's specific type. So instead we
+  // create a synthetic object.
+  WRL::ComPtr<V8CachedObject> cached_object = WRL::Make<V8CachedObject>(
+      Location(address), uncompressed_type_name, sp_ctx,
+      /*is_compressed=*/true);
+  return CreateSyntheticObjectForV8Object(sp_ctx.Get(), cached_object.Get(),
+                                          result);
+}
+
+// Creates an IModelObject representing the value of a bitfield.
+HRESULT GetModelForBitField(uint64_t address, const uint8_t num_bits,
+                            uint8_t shift_bits, const std::u16string& type_name,
+                            WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                            IModelObject** result) {
+  // Look up the type by name.
+  WRL::ComPtr<IDebugHostType> type =
+      Extension::Current()->GetTypeFromV8Module(sp_ctx, type_name.c_str());
+  if (type == nullptr) return E_FAIL;
+
+  // Figure out exactly which bytes contain the bitfield's data. This depends on
+  // platform byte order (little-endian for Windows).
+  constexpr int kBitsPerByte = 8;
+  uint8_t shift_bytes = shift_bits / kBitsPerByte;
+  address += shift_bytes;
+  shift_bits -= shift_bytes * kBitsPerByte;
+  size_t bits_to_read = shift_bits + num_bits;
+  size_t bytes_to_read = (bits_to_read + kBitsPerByte - 1) / kBitsPerByte;
+
+  uintptr_t value = 0;
+
+  // V8 guarantees that bitfield structs are no bigger than a single pointer.
+  if (bytes_to_read > sizeof(value)) {
+    std::stringstream message;
+    message << "Fatal v8windbg error: found bitfield struct of "
+            << bytes_to_read << "bytes, which exceeds the supported size of "
+            << sizeof(value);
+    return CreateString(ConvertToU16String(message.str()), result);
+  }
+
+  uint64_t bytes_read;
+  HRESULT hr = sp_debug_host_memory->ReadBytes(sp_ctx.Get(), address,
+                                               reinterpret_cast<void*>(&value),
+                                               bytes_to_read, &bytes_read);
+
+  // S_FALSE can be returned if fewer bytes were read than were requested. We
+  // need all of the bytes, so check for S_OK.
+  if (hr != S_OK) {
+    std::stringstream message;
+    message << "Unable to read memory at 0x" << std::hex << address;
+    return CreateString(ConvertToU16String(message.str()), result);
+  }
+
+  // Decode the bitfield.
+  value = (value >> shift_bits) & ((1 << num_bits) - 1);
+
+  return CreateTypedIntrinsic(value, type.Get(), result);
+}
+
+// Creates an IModelObject to represent the packed fields in a Torque struct.
+// Note that Torque structs are not C++ structs and do not have any type
+// definitions in the V8 symbols.
+HRESULT GetModelForStruct(const uint64_t address,
+                          const std::vector<StructField>& fields,
+                          WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                          IModelObject** result) {
+  WRL::ComPtr<IModelObject> sp_value;
+  RETURN_IF_FAIL(
+      sp_data_model_manager->CreateSyntheticObject(sp_ctx.Get(), &sp_value));
+
+  // There's no need for any fancy Concepts here; just add key-value pairs for
+  // each field.
+  for (const StructField& field : fields) {
+    WRL::ComPtr<IModelObject> field_model;
+    if (field.num_bits == 0) {
+      RETURN_IF_FAIL(GetModelForBasicField(
+          address + field.offset, field.type_name, field.uncompressed_type_name,
+          sp_ctx, &field_model));
+    } else {
+      RETURN_IF_FAIL(GetModelForBitField(address + field.offset, field.num_bits,
+                                         field.shift_bits, field.type_name,
+                                         sp_ctx, &field_model));
+    }
+    RETURN_IF_FAIL(
+        sp_value->SetKey(reinterpret_cast<const wchar_t*>(field.name.c_str()),
+                         field_model.Get(), nullptr));
+  }
+
+  *result = sp_value.Detach();
+  return S_OK;
+}
+
+// Creates an IModelObject representing an array of some type that we expect to
+// be defined in the V8 symbols.
+HRESULT GetModelForNativeArray(const uint64_t address,
+                               const std::u16string& type_name, size_t count,
+                               WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                               IModelObject** result) {
+  WRL::ComPtr<IDebugHostType> type =
+      Extension::Current()->GetTypeFromV8Module(sp_ctx, type_name.c_str());
+  if (type == nullptr) return E_FAIL;
+
+  ULONG64 object_size{};
+  RETURN_IF_FAIL(type->GetSize(&object_size));
+
+  ArrayDimension dimensions[] = {
+      {/*start=*/0, /*length=*/count, /*stride=*/object_size}};
+  WRL::ComPtr<IDebugHostType> array_type;
+  RETURN_IF_FAIL(
+      type->CreateArrayOf(/*dimensions=*/1, dimensions, &array_type));
+
+  return sp_data_model_manager->CreateTypedObject(
+      sp_ctx.Get(), Location{address}, array_type.Get(), result);
+}
+
+// Creates an IModelObject that represents an array of structs or compressed
+// tagged values.
+HRESULT GetModelForCustomArray(const Property& prop,
+                               WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                               IModelObject** result) {
+  // Create the context which should be provided to the indexing and iterating
+  // functionality provided by the parent model. This is instance-specific data,
+  // whereas the parent model object could be shared among many custom arrays.
+  WRL::ComPtr<IndexedFieldData> context_data =
+      WRL::Make<IndexedFieldData>(prop);
+
+  return CreateSyntheticObjectWithParentAndDataContext(
+      sp_ctx.Get(), Extension::Current()->GetIndexedFieldDataModel(),
+      context_data.Get(), result);
+}
+
+// Creates an IModelObject representing the data in the given property.
+HRESULT GetModelForProperty(const Property& prop,
+                            WRL::ComPtr<IDebugHostContext>& sp_ctx,
+                            IModelObject** result) {
+  switch (prop.type) {
+    case PropertyType::kPointer:
+      return GetModelForBasicField(prop.addr_value, prop.type_name,
+                                   prop.uncompressed_type_name, sp_ctx, result);
+    case PropertyType::kStruct:
+      return GetModelForStruct(prop.addr_value, prop.fields, sp_ctx, result);
+    case PropertyType::kArray:
+    case PropertyType::kStructArray:
+      if (prop.type == PropertyType::kArray &&
+          prop.type_name == ConvertToU16String(prop.uncompressed_type_name)) {
+        // An array of things that are not structs or compressed tagged values
+        // is most cleanly represented by a native array.
+        return GetModelForNativeArray(prop.addr_value, prop.type_name,
+                                      prop.length, sp_ctx, result);
+      }
+      // Otherwise, we must construct a custom iterable object.
+      return GetModelForCustomArray(prop, sp_ctx, result);
+    default:
+      return E_FAIL;
+  }
+}
+
+// Creates an IModelObject representing the data in an array at the given index.
+// context_object is expected to be an object of the form created by
+// GetModelForCustomArray, meaning its context for the IndexedFieldParent data
+// model is an IIndexedFieldData containing the description of the array.
+HRESULT GetModelForCustomArrayElement(IModelObject* context_object,
+                                      size_t index, IModelObject** object) {
+  // Open a few layers of wrapper objects to get to the Property object that
+  // describes the array.
+  WRL::ComPtr<IUnknown> data_model_context;
+  RETURN_IF_FAIL(context_object->GetContextForDataModel(
+      Extension::Current()->GetIndexedFieldDataModel(), &data_model_context));
+  WRL::ComPtr<IIndexedFieldData> indexed_field_data;
+  RETURN_IF_FAIL(data_model_context.As(&indexed_field_data));
+  Property* prop;
+  RETURN_IF_FAIL(indexed_field_data->GetProperty(&prop));
+
+  if (index >= prop->length) {
+    return E_BOUNDS;
+  }
+
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+
+  ULONG64 address = prop->addr_value + index * prop->item_size;
+
+  switch (prop->type) {
+    case PropertyType::kArray:
+      return GetModelForBasicField(address, prop->type_name,
+                                   prop->uncompressed_type_name, sp_ctx,
+                                   object);
+    case PropertyType::kStructArray:
+      return GetModelForStruct(address, prop->fields, sp_ctx, object);
+    default:
+      return E_FAIL;  // Only array properties should be possible here.
+  }
+}
+
+}  // namespace
+
+IFACEMETHODIMP IndexedFieldParent::InitializeObject(
+    IModelObject* model_object,
+    IDebugHostTypeSignature* matching_type_signature,
+    IDebugHostSymbolEnumerator* wildcard_matches) noexcept {
+  return S_OK;
+}
+
+IFACEMETHODIMP IndexedFieldParent::GetName(BSTR* model_name) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP IndexedFieldParent::GetDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP IndexedFieldParent::GetAt(IModelObject* context_object,
+                                         ULONG64 indexer_count,
+                                         IModelObject** indexers,
+                                         IModelObject** object,
+                                         IKeyStore** metadata) noexcept {
+  if (indexer_count != 1) return E_INVALIDARG;
+  if (metadata != nullptr) *metadata = nullptr;
+
+  ULONG64 index;
+  RETURN_IF_FAIL(UnboxULong64(indexers[0], &index, /*convert=*/true));
+
+  return GetModelForCustomArrayElement(context_object, index, object);
+}
+
+IFACEMETHODIMP IndexedFieldParent::SetAt(IModelObject* context_object,
+                                         ULONG64 indexer_count,
+                                         IModelObject** indexers,
+                                         IModelObject* value) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP IndexedFieldParent::GetDefaultIndexDimensionality(
+    IModelObject* context_object, ULONG64* dimensionality) noexcept {
+  *dimensionality = 1;
+  return S_OK;
+}
+
+IFACEMETHODIMP IndexedFieldParent::GetIterator(
+    IModelObject* context_object, IModelIterator** iterator) noexcept {
+  auto indexed_field_iterator{WRL::Make<IndexedFieldIterator>(context_object)};
+  *iterator = indexed_field_iterator.Detach();
+  return S_OK;
+}
+
+IndexedFieldIterator::IndexedFieldIterator(IModelObject* context_object)
+    : context_object_(context_object) {}
+IndexedFieldIterator::~IndexedFieldIterator() = default;
+
+IFACEMETHODIMP IndexedFieldIterator::Reset() noexcept {
+  next_ = 0;
+  return S_OK;
+}
+
+IFACEMETHODIMP IndexedFieldIterator::GetNext(IModelObject** object,
+                                             ULONG64 dimensions,
+                                             IModelObject** indexers,
+                                             IKeyStore** metadata) noexcept {
+  if (dimensions > 1) return E_INVALIDARG;
+
+  WRL::ComPtr<IModelObject> sp_index, sp_value;
+  RETURN_IF_FAIL(
+      GetModelForCustomArrayElement(context_object_.Get(), next_, &sp_value));
+  RETURN_IF_FAIL(CreateULong64(next_, &sp_index));
+
+  // Everything that could fail (including the bounds check) has succeeded, so
+  // increment the index.
+  ++next_;
+
+  // Write results (none of these steps can fail, which is important because we
+  // transfer ownership of two separate objects).
+  if (dimensions == 1) {
+    indexers[0] = sp_index.Detach();
+  }
+  *object = sp_value.Detach();
+  if (metadata != nullptr) *metadata = nullptr;
+  return S_OK;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::GetKey(IModelObject* context_object,
+                                         PCWSTR key, IModelObject** key_value,
+                                         IKeyStore** metadata,
+                                         bool* has_key) noexcept {
+  if (metadata != nullptr) *metadata = nullptr;
+
+  WRL::ComPtr<IV8CachedObject> sp_v8_cached_object;
+  RETURN_IF_FAIL(GetCachedObject(context_object, &sp_v8_cached_object));
+  V8HeapObject* p_v8_heap_object;
+  RETURN_IF_FAIL(sp_v8_cached_object->GetCachedV8HeapObject(&p_v8_heap_object));
+
+  *has_key = false;
+  for (const auto& prop : p_v8_heap_object->properties) {
+    const char16_t* p_key = reinterpret_cast<const char16_t*>(key);
+    if (prop.name.compare(p_key) == 0) {
+      *has_key = true;
+      if (key_value != nullptr) {
+        WRL::ComPtr<IDebugHostContext> sp_ctx;
+        RETURN_IF_FAIL(context_object->GetContext(&sp_ctx));
+        RETURN_IF_FAIL(GetModelForProperty(prop, sp_ctx, key_value));
+      }
+      return S_OK;
+    }
+  }
+
+  return S_OK;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::SetKey(IModelObject* context_object,
+                                         PCWSTR key, IModelObject* key_value,
+                                         IKeyStore* metadata) noexcept {
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP V8ObjectDataModel::EnumerateKeys(
+    IModelObject* context_object, IKeyEnumerator** pp_enumerator) noexcept {
+  WRL::ComPtr<IV8CachedObject> sp_v8_cached_object;
+  RETURN_IF_FAIL(GetCachedObject(context_object, &sp_v8_cached_object));
+
+  auto enumerator{WRL::Make<V8ObjectKeyEnumerator>(sp_v8_cached_object)};
+  *pp_enumerator = enumerator.Detach();
+  return S_OK;
+}
+
+IFACEMETHODIMP V8LocalValueProperty::GetValue(
+    PCWSTR pwsz_key, IModelObject* p_v8_local_instance,
+    IModelObject** pp_value) noexcept {
+  // Get the parametric type within v8::Local<*>
+  // Set value to a pointer to an instance of this type.
+
+  WRL::ComPtr<IDebugHostType> sp_type;
+  RETURN_IF_FAIL(p_v8_local_instance->GetTypeInfo(&sp_type));
+
+  bool is_generic;
+  RETURN_IF_FAIL(sp_type->IsGeneric(&is_generic));
+  if (!is_generic) return E_FAIL;
+
+  WRL::ComPtr<IDebugHostSymbol> sp_generic_arg;
+  RETURN_IF_FAIL(sp_type->GetGenericArgumentAt(0, &sp_generic_arg));
+
+  _bstr_t generic_name;
+  RETURN_IF_FAIL(sp_generic_arg->GetName(generic_name.GetAddress()));
+
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(p_v8_local_instance->GetContext(&sp_ctx));
+
+  WRL::ComPtr<IDebugHostType> sp_value_type =
+      Extension::Current()->GetTypeFromV8Module(
+          sp_ctx, reinterpret_cast<const char16_t*>(
+                      static_cast<const wchar_t*>(generic_name)));
+  if (sp_value_type == nullptr ||
+      !Extension::Current()->DoesTypeDeriveFromObject(sp_value_type)) {
+    // The value type doesn't derive from v8::internal::Object (probably a
+    // public API type), so just use plain v8::internal::Object. We could
+    // consider mapping some public API types to their corresponding internal
+    // types here, at the possible cost of increased maintenance.
+    sp_value_type = Extension::Current()->GetV8ObjectType(sp_ctx);
+  }
+
+  Location loc;
+  RETURN_IF_FAIL(p_v8_local_instance->GetLocation(&loc));
+
+  // Read the pointer at the Object location
+  ULONG64 obj_address;
+  RETURN_IF_FAIL(
+      sp_debug_host_memory->ReadPointers(sp_ctx.Get(), loc, 1, &obj_address));
+
+  // If the val_ is a nullptr, then there is no value in the Local.
+  if (obj_address == 0) {
+    RETURN_IF_FAIL(CreateString(std::u16string{u"<empty>"}, pp_value));
+  } else {
+    // Should be a v8::internal::Object at the address
+    RETURN_IF_FAIL(sp_data_model_manager->CreateTypedObject(
+        sp_ctx.Get(), obj_address, sp_value_type.Get(), pp_value));
+  }
+
+  return S_OK;
+}
+
+IFACEMETHODIMP V8LocalValueProperty::SetValue(
+    PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+    IModelObject* /*p_value*/) noexcept {
+  return E_NOTIMPL;
+}
+
+constexpr wchar_t usage[] =
+    LR"(Invalid arguments.
+First argument should be a uint64 representing the tagged value to investigate.
+Second argument is optional, and may be a fully-qualified type name such as
+v8::internal::String.)";
+
+IFACEMETHODIMP InspectV8ObjectMethod::Call(IModelObject* p_context_object,
+                                           ULONG64 arg_count,
+                                           _In_reads_(arg_count)
+                                               IModelObject** pp_arguments,
+                                           IModelObject** pp_result,
+                                           IKeyStore** pp_metadata) noexcept {
+  // Read the arguments.
+  ULONG64 tagged_value;
+  _bstr_t type_name;
+  if (arg_count < 1 ||
+      FAILED(UnboxULong64(pp_arguments[0], &tagged_value, /*convert=*/true)) ||
+      (arg_count >= 2 &&
+       FAILED(UnboxString(pp_arguments[1], type_name.GetAddress())))) {
+    sp_data_model_manager->CreateErrorObject(E_INVALIDARG, usage, pp_result);
+    return E_INVALIDARG;
+  }
+
+  WRL::ComPtr<IDebugHostContext> sp_ctx;
+  RETURN_IF_FAIL(sp_debug_host->GetCurrentContext(&sp_ctx));
+
+  // We can't use CreateTypedObject for a value which may not actually reside
+  // anywhere in memory, so create a synthetic object.
+  WRL::ComPtr<V8CachedObject> cached_object =
+      WRL::Make<V8CachedObject>(::GetHeapObject(
+          sp_ctx, tagged_value, 0, static_cast<const char*>(type_name),
+          /*is_compressed=*/false));
+  return CreateSyntheticObjectForV8Object(sp_ctx.Get(), cached_object.Get(),
+                                          pp_result);
+}
diff --git a/deps/v8/tools/v8windbg/src/object-inspection.h b/deps/v8/tools/v8windbg/src/object-inspection.h
new file mode 100644
index 0000000000..27283ca556
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/object-inspection.h
@@ -0,0 +1,261 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_OBJECT_INSPECTION_H_
+#define V8_TOOLS_V8WINDBG_SRC_OBJECT_INSPECTION_H_
+
+#include <comutil.h>
+#include <wrl/implements.h>
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "tools/v8windbg/base/dbgext.h"
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+// The representation of the underlying V8 object that will be cached on the
+// DataModel representation. (Needs to implement IUnknown).
+class __declspec(uuid("6392E072-37BB-4220-A5FF-114098923A02")) IV8CachedObject
+    : public IUnknown {
+ public:
+  virtual HRESULT __stdcall GetCachedV8HeapObject(
+      V8HeapObject** pp_heap_object) = 0;
+};
+
+class V8CachedObject
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IV8CachedObject> {
+ public:
+  V8CachedObject(Location location, std::string uncompressed_type_name,
+                 WRL::ComPtr<IDebugHostContext> context, bool is_compressed);
+  V8CachedObject(V8HeapObject heap_object);
+  ~V8CachedObject() override;
+
+  static HRESULT Create(IModelObject* p_v8_object_instance,
+                        IV8CachedObject** result);
+
+  IFACEMETHOD(GetCachedV8HeapObject)(V8HeapObject** pp_heap_object);
+
+ private:
+  // The properties and description of the object, if already read.
+  V8HeapObject heap_object_;
+  bool heap_object_initialized_ = false;
+
+  // Data that is necessary for reading the object.
+  Location location_;
+  std::string uncompressed_type_name_;
+  WRL::ComPtr<IDebugHostContext> context_;
+  bool is_compressed_ = false;
+};
+
+// A simple COM wrapper class to hold data required for IndexedFieldParent.
+// (Needs to implement IUnknown).
+class __declspec(uuid("6392E072-37BB-4220-A5FF-114098923A03")) IIndexedFieldData
+    : public IUnknown {
+ public:
+  // Get a pointer to the Property object held by this IIndexedFieldData. The
+  // pointer returned in this way is valid only while the containing
+  // IIndexedFieldData is alive.
+  virtual HRESULT __stdcall GetProperty(Property** property) = 0;
+};
+
+class IndexedFieldData
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IIndexedFieldData> {
+ public:
+  IndexedFieldData(Property property);
+  ~IndexedFieldData() override;
+
+  // Get a pointer to the Property object held by this IndexedFieldData. The
+  // pointer returned in this way is valid only while the containing
+  // IndexedFieldData is alive.
+  IFACEMETHOD(GetProperty)(Property** property);
+
+ private:
+  Property property_;
+};
+
+// A parent model that provides indexing support for fields that contain arrays
+// of something more complicated than basic native types.
+class IndexedFieldParent
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IDataModelConcept, IIterableConcept, IIndexableConcept> {
+ public:
+  // IDataModelConcept
+  IFACEMETHOD(InitializeObject)
+  (IModelObject* model_object, IDebugHostTypeSignature* matching_type_signature,
+   IDebugHostSymbolEnumerator* wildcard_matches);
+
+  // IDataModelConcept
+  IFACEMETHOD(GetName)(BSTR* model_name);
+
+  // IIndexableConcept
+  IFACEMETHOD(GetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   _COM_Errorptr_ IModelObject** object, IKeyStore** metadata);
+
+  // IIndexableConcept
+  IFACEMETHOD(GetDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  // IIndexableConcept
+  IFACEMETHOD(SetAt)
+  (IModelObject* context_object, ULONG64 indexer_count, IModelObject** indexers,
+   IModelObject* value);
+
+  // IIterableConcept
+  IFACEMETHOD(GetDefaultIndexDimensionality)
+  (IModelObject* context_object, ULONG64* dimensionality);
+
+  // IIterableConcept
+  IFACEMETHOD(GetIterator)
+  (IModelObject* context_object, IModelIterator** iterator);
+};
+
+// An iterator for the values within an array field.
+class IndexedFieldIterator
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelIterator> {
+ public:
+  IndexedFieldIterator(IModelObject* context_object);
+  ~IndexedFieldIterator() override;
+
+  IFACEMETHOD(Reset)();
+
+  IFACEMETHOD(GetNext)
+  (IModelObject** object, ULONG64 dimensions, IModelObject** indexers,
+   IKeyStore** metadata);
+
+ private:
+  size_t next_ = 0;
+  WRL::ComPtr<IModelObject> context_object_;
+};
+
+// Enumerates the names of fields on V8 objects.
+class V8ObjectKeyEnumerator
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IKeyEnumerator> {
+ public:
+  V8ObjectKeyEnumerator(WRL::ComPtr<IV8CachedObject>& v8_cached_object);
+  ~V8ObjectKeyEnumerator() override;
+
+  IFACEMETHOD(Reset)();
+
+  // This method will be called with a nullptr 'value' for each key if returned
+  // from an IDynamicKeyProviderConcept. It will call GetKey on the
+  // IDynamicKeyProviderConcept interface after each key returned.
+  IFACEMETHOD(GetNext)(BSTR* key, IModelObject** value, IKeyStore** metadata);
+
+ private:
+  int index_ = 0;
+  WRL::ComPtr<IV8CachedObject> sp_v8_cached_object_;
+};
+
+// A parent model for V8 handle types such as v8::internal::Handle<*>.
+class V8LocalDataModel
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IDataModelConcept> {
+ public:
+  IFACEMETHOD(InitializeObject)
+  (IModelObject* model_object, IDebugHostTypeSignature* matching_type_signature,
+   IDebugHostSymbolEnumerator* wildcard_matches);
+
+  IFACEMETHOD(GetName)(BSTR* model_name);
+};
+
+// A parent model for V8 object types such as v8::internal::Object.
+class V8ObjectDataModel
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IDataModelConcept, IStringDisplayableConcept,
+          IDynamicKeyProviderConcept> {
+ public:
+  HRESULT GetCachedObject(IModelObject* context_object,
+                          IV8CachedObject** result) {
+    // Get the IModelObject for this parent object. As it is a dynamic provider,
+    // there is only one parent directly on the object.
+    WRL::ComPtr<IModelObject> sp_parent_model, sp_context_adjuster;
+    RETURN_IF_FAIL(context_object->GetParentModel(0, &sp_parent_model,
+                                                  &sp_context_adjuster));
+
+    // See if the cached object is already present
+    WRL::ComPtr<IUnknown> sp_context;
+    HRESULT hr = context_object->GetContextForDataModel(sp_parent_model.Get(),
+                                                        &sp_context);
+
+    WRL::ComPtr<IV8CachedObject> sp_v8_cached_object;
+
+    if (SUCCEEDED(hr)) {
+      RETURN_IF_FAIL(sp_context.As(&sp_v8_cached_object));
+    } else {
+      RETURN_IF_FAIL(
+          V8CachedObject::Create(context_object, &sp_v8_cached_object));
+      RETURN_IF_FAIL(sp_v8_cached_object.As(&sp_context));
+      RETURN_IF_FAIL(context_object->SetContextForDataModel(
+          sp_parent_model.Get(), sp_context.Get()));
+    }
+
+    *result = sp_v8_cached_object.Detach();
+    return S_OK;
+  }
+
+  IFACEMETHOD(InitializeObject)
+  (IModelObject* model_object, IDebugHostTypeSignature* matching_type_signature,
+   IDebugHostSymbolEnumerator* wildcard_matches);
+
+  IFACEMETHOD(GetName)(BSTR* model_name);
+
+  IFACEMETHOD(ToDisplayString)
+  (IModelObject* context_object, IKeyStore* metadata, BSTR* display_string);
+
+  // IDynamicKeyProviderConcept
+  IFACEMETHOD(GetKey)
+  (IModelObject* context_object, PCWSTR key, IModelObject** key_value,
+   IKeyStore** metadata, bool* has_key);
+
+  IFACEMETHOD(SetKey)
+  (IModelObject* context_object, PCWSTR key, IModelObject* key_value,
+   IKeyStore* metadata);
+
+  IFACEMETHOD(EnumerateKeys)
+  (IModelObject* context_object, IKeyEnumerator** pp_enumerator);
+};
+
+// The implemention of the "Value" getter for V8 handle types.
+class V8LocalValueProperty
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelPropertyAccessor> {
+ public:
+  IFACEMETHOD(GetValue)
+  (PCWSTR pwsz_key, IModelObject* p_v8_object_instance,
+   IModelObject** pp_value);
+
+  IFACEMETHOD(SetValue)
+  (PCWSTR /*pwsz_key*/, IModelObject* /*p_process_instance*/,
+   IModelObject* /*p_value*/);
+};
+
+// A way that someone can directly inspect a tagged value, even if that value
+// isn't in memory (from a register, or the user's imagination, etc.).
+class InspectV8ObjectMethod
+    : public WRL::RuntimeClass<
+          WRL::RuntimeClassFlags<WRL::RuntimeClassType::ClassicCom>,
+          IModelMethod> {
+ public:
+  IFACEMETHOD(Call)
+  (IModelObject* p_context_object, ULONG64 arg_count,
+   _In_reads_(arg_count) IModelObject** pp_arguments, IModelObject** pp_result,
+   IKeyStore** pp_metadata);
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_OBJECT_INSPECTION_H_
diff --git a/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.cc b/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.cc
new file mode 100644
index 0000000000..4a8dcc9add
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.cc
@@ -0,0 +1,157 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/v8-debug-helper-interop.h"
+
+#include <Windows.h>
+#include <crtdbg.h>
+
+#include "src/common/globals.h"
+#include "tools/debug_helper/debug-helper.h"
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+namespace d = v8::debug_helper;
+
+// We need a plain C function pointer for interop with v8_debug_helper. We can
+// use this to get one as long as we never need two at once.
+class MemReaderScope {
+ public:
+  explicit MemReaderScope(WRL::ComPtr<IDebugHostContext> sp_context)
+      : sp_context_(sp_context) {
+    _ASSERTE(!context_);
+    context_ = sp_context_.Get();
+  }
+  ~MemReaderScope() { context_ = nullptr; }
+  d::MemoryAccessor GetReader() { return &MemReaderScope::Read; }
+
+ private:
+  MemReaderScope(const MemReaderScope&) = delete;
+  MemReaderScope& operator=(const MemReaderScope&) = delete;
+  static d::MemoryAccessResult Read(uintptr_t address, uint8_t* destination,
+                                    size_t byte_count) {
+    ULONG64 bytes_read;
+    Location loc{address};
+    HRESULT hr = sp_debug_host_memory->ReadBytes(context_, loc, destination,
+                                                 byte_count, &bytes_read);
+    // TODO determine when an address is valid but inaccessible
+    return SUCCEEDED(hr) ? d::MemoryAccessResult::kOk
+                         : d::MemoryAccessResult::kAddressNotValid;
+  }
+  WRL::ComPtr<IDebugHostContext> sp_context_;
+  static IDebugHostContext* context_;
+};
+IDebugHostContext* MemReaderScope::context_;
+
+StructField::StructField(std::u16string field_name, std::u16string type_name,
+                         std::string uncompressed_type_name, uint64_t offset,
+                         uint8_t num_bits, uint8_t shift_bits)
+    : name(field_name),
+      type_name(type_name),
+      uncompressed_type_name(uncompressed_type_name),
+      offset(offset),
+      num_bits(num_bits),
+      shift_bits(shift_bits) {}
+StructField::~StructField() = default;
+StructField::StructField(const StructField&) = default;
+StructField::StructField(StructField&&) = default;
+StructField& StructField::operator=(const StructField&) = default;
+StructField& StructField::operator=(StructField&&) = default;
+
+Property::Property(std::u16string property_name, std::u16string type_name,
+                   std::string uncompressed_type_name, uint64_t address,
+                   size_t item_size)
+    : name(property_name),
+      type(PropertyType::kPointer),
+      type_name(type_name),
+      uncompressed_type_name(uncompressed_type_name),
+      addr_value(address),
+      item_size(item_size) {}
+Property::~Property() = default;
+Property::Property(const Property&) = default;
+Property::Property(Property&&) = default;
+Property& Property::operator=(const Property&) = default;
+Property& Property::operator=(Property&&) = default;
+
+V8HeapObject::V8HeapObject() = default;
+V8HeapObject::~V8HeapObject() = default;
+V8HeapObject::V8HeapObject(const V8HeapObject&) = default;
+V8HeapObject::V8HeapObject(V8HeapObject&&) = default;
+V8HeapObject& V8HeapObject::operator=(const V8HeapObject&) = default;
+V8HeapObject& V8HeapObject::operator=(V8HeapObject&&) = default;
+
+V8HeapObject GetHeapObject(WRL::ComPtr<IDebugHostContext> sp_context,
+                           uint64_t tagged_ptr, uint64_t referring_pointer,
+                           const char* type_name, bool is_compressed) {
+  // Read the value at the address, and see if it is a tagged pointer
+
+  V8HeapObject obj;
+  MemReaderScope reader_scope(sp_context);
+
+  d::HeapAddresses heap_addresses = {0, 0, 0, 0};
+  // TODO ideally we'd provide real heap page pointers. For now, just testing
+  // decompression based on the pointer to wherever we found this value,
+  // which is likely (though not guaranteed) to be a heap pointer itself.
+  heap_addresses.any_heap_pointer = referring_pointer;
+
+  auto props = d::GetObjectProperties(tagged_ptr, reader_scope.GetReader(),
+                                      heap_addresses, type_name);
+  obj.friendly_name = ConvertToU16String(props->brief);
+  for (size_t property_index = 0; property_index < props->num_properties;
+       ++property_index) {
+    const auto& source_prop = *props->properties[property_index];
+    Property dest_prop(ConvertToU16String(source_prop.name),
+                       ConvertToU16String(source_prop.type),
+                       source_prop.decompressed_type, source_prop.address,
+                       source_prop.size);
+    if (source_prop.kind != d::PropertyKind::kSingle) {
+      dest_prop.type = PropertyType::kArray;
+      dest_prop.length = source_prop.num_values;
+    }
+    if (dest_prop.type_name.empty() || source_prop.num_struct_fields > 0) {
+      // If the helper library didn't provide a type, then it should have
+      // provided struct fields instead. Set the struct type flag and copy the
+      // fields into the result.
+      dest_prop.type =
+          static_cast<PropertyType>(static_cast<int>(dest_prop.type) |
+                                    static_cast<int>(PropertyType::kStruct));
+      for (size_t field_index = 0; field_index < source_prop.num_struct_fields;
+           ++field_index) {
+        const auto& struct_field = *source_prop.struct_fields[field_index];
+        dest_prop.fields.push_back({ConvertToU16String(struct_field.name),
+                                    ConvertToU16String(struct_field.type),
+                                    struct_field.decompressed_type,
+                                    struct_field.offset, struct_field.num_bits,
+                                    struct_field.shift_bits});
+      }
+    }
+    obj.properties.push_back(dest_prop);
+  }
+
+  // For each guessed type, create a synthetic property that will request data
+  // about the same object again but with a more specific type hint.
+  if (referring_pointer != 0) {
+    for (size_t type_index = 0; type_index < props->num_guessed_types;
+         ++type_index) {
+      const std::string& type_name = props->guessed_types[type_index];
+      Property dest_prop(
+          ConvertToU16String(("guessed type " + type_name).c_str()),
+          ConvertToU16String(is_compressed ? kTaggedValue : type_name),
+          type_name, referring_pointer,
+          is_compressed ? i::kTaggedSize : sizeof(void*));
+      obj.properties.push_back(dest_prop);
+    }
+  }
+
+  return obj;
+}
+
+std::vector<std::u16string> ListObjectClasses() {
+  const d::ClassList* class_list = d::ListObjectClasses();
+  std::vector<std::u16string> result;
+  for (size_t i = 0; i < class_list->num_class_names; ++i) {
+    result.push_back(ConvertToU16String(class_list->class_names[i]));
+  }
+  return result;
+}
diff --git a/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.h b/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.h
new file mode 100644
index 0000000000..96bd59b30e
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/v8-debug-helper-interop.h
@@ -0,0 +1,138 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_
+#define V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_
+
+#include <wrl/client.h>
+
+#include <DbgModel.h>
+
+#include <cstdint>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace WRL = Microsoft::WRL;
+
+constexpr char kObject[] = "v8::internal::Object";
+constexpr char16_t kObjectU[] = u"v8::internal::Object";
+constexpr char kTaggedValue[] = "v8::internal::TaggedValue";
+constexpr char16_t kTaggedValueU[] = u"v8::internal::TaggedValue";
+
+enum class PropertyType {
+  kPointer = 0,
+  kArray = 1,
+  kStruct = 2,
+  kStructArray = kArray | kStruct,
+};
+
+struct StructField {
+  StructField(std::u16string field_name, std::u16string type_name,
+              std::string uncompressed_type_name, uint64_t address,
+              uint8_t num_bits, uint8_t shift_bits);
+  ~StructField();
+  StructField(const StructField&);
+  StructField(StructField&&);
+  StructField& operator=(const StructField&);
+  StructField& operator=(StructField&&);
+
+  std::u16string name;
+
+  // Statically-determined type, such as from .tq definition. This type should
+  // be treated as if it were used in the v8::internal namespace; that is, type
+  // "X::Y" can mean any of the following, in order of decreasing preference:
+  // - v8::internal::X::Y
+  // - v8::X::Y
+  // - X::Y
+  std::u16string type_name;
+
+  // In some cases, |type_name| may be a simple type representing a compressed
+  // pointer such as v8::internal::TaggedValue. In those cases,
+  // |uncompressed_type_name| will contain the type of the object when
+  // decompressed. Otherwise, |uncompressed_type_name| will match |type_name|.
+  // In any case, it is safe to pass the |uncompressed_type_name| value as the
+  // type_hint on a subsequent call to GetObjectProperties.
+  std::string uncompressed_type_name;
+
+  // Offset, in bytes, from beginning of struct.
+  uint64_t offset;
+
+  // The number of bits that are present, if this value is a bitfield. Zero
+  // indicates that this value is not a bitfield (the full value is stored).
+  uint8_t num_bits;
+
+  // The number of bits by which this value has been left-shifted for storage as
+  // a bitfield.
+  uint8_t shift_bits;
+};
+
+struct Property {
+  Property(std::u16string property_name, std::u16string type_name,
+           std::string uncompressed_type_name, uint64_t address,
+           size_t item_size);
+  ~Property();
+  Property(const Property&);
+  Property(Property&&);
+  Property& operator=(const Property&);
+  Property& operator=(Property&&);
+
+  std::u16string name;
+  PropertyType type;
+
+  // Statically-determined type, such as from .tq definition. Can be an empty
+  // string if this property is itself a Torque-defined struct; in that case use
+  // |fields| instead. This type should be treated as if it were used in the
+  // v8::internal namespace; that is, type "X::Y" can mean any of the following,
+  // in order of decreasing preference:
+  // - v8::internal::X::Y
+  // - v8::X::Y
+  // - X::Y
+  std::u16string type_name;
+
+  // In some cases, |type_name| may be a simple type representing a compressed
+  // pointer such as v8::internal::TaggedValue. In those cases,
+  // |uncompressed_type_name| will contain the type of the object when
+  // decompressed. Otherwise, |uncompressed_type_name| will match |type_name|.
+  // In any case, it is safe to pass the |uncompressed_type_name| value as the
+  // type_hint on a subsequent call to GetObjectProperties.
+  std::string uncompressed_type_name;
+
+  // The address where the property value can be found in the debuggee's address
+  // space, or the address of the first value for an array.
+  uint64_t addr_value;
+
+  // Size of each array item, if this property is an array.
+  size_t item_size;
+
+  // Number of array items, if this property is an array.
+  size_t length = 0;
+
+  // Fields within this property, if this property is a struct, or fields within
+  // each array element, if this property is a struct array.
+  std::vector<StructField> fields;
+};
+
+struct V8HeapObject {
+  V8HeapObject();
+  ~V8HeapObject();
+  V8HeapObject(const V8HeapObject&);
+  V8HeapObject(V8HeapObject&&);
+  V8HeapObject& operator=(const V8HeapObject&);
+  V8HeapObject& operator=(V8HeapObject&&);
+  std::u16string friendly_name;  // String to print in single-line description.
+  std::vector<Property> properties;
+};
+
+V8HeapObject GetHeapObject(WRL::ComPtr<IDebugHostContext> sp_context,
+                           uint64_t address, uint64_t referring_pointer,
+                           const char* type_name, bool is_compressed);
+
+// Expand a compressed pointer from 32 bits to the format that
+// GetObjectProperties expects for compressed pointers.
+inline uint64_t ExpandCompressedPointer(uint32_t ptr) { return ptr; }
+
+std::vector<std::u16string> ListObjectClasses();
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_V8_DEBUG_HELPER_INTEROP_H_
diff --git a/deps/v8/tools/v8windbg/src/v8windbg-extension.cc b/deps/v8/tools/v8windbg/src/v8windbg-extension.cc
new file mode 100644
index 0000000000..68c90d2833
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/v8windbg-extension.cc
@@ -0,0 +1,340 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/src/v8windbg-extension.h"
+
+#include <iostream>
+
+#include "tools/v8windbg/base/utilities.h"
+#include "tools/v8windbg/src/cur-isolate.h"
+#include "tools/v8windbg/src/list-chunks.h"
+#include "tools/v8windbg/src/local-variables.h"
+#include "tools/v8windbg/src/object-inspection.h"
+
+std::unique_ptr<Extension> Extension::current_extension_ = nullptr;
+const wchar_t* pcur_isolate = L"curisolate";
+const wchar_t* plist_chunks = L"listchunks";
+const wchar_t* pv8_object = L"v8object";
+
+HRESULT CreateExtension() {
+  if (Extension::Current() != nullptr || sp_data_model_manager == nullptr ||
+      sp_debug_host == nullptr) {
+    return E_FAIL;
+  } else {
+    std::unique_ptr<Extension> new_extension(new (std::nothrow) Extension());
+    if (new_extension == nullptr) return E_FAIL;
+    RETURN_IF_FAIL(new_extension->Initialize());
+    Extension::SetExtension(std::move(new_extension));
+    return S_OK;
+  }
+}
+
+void DestroyExtension() { Extension::SetExtension(nullptr); }
+
+bool Extension::DoesTypeDeriveFromObject(
+    const WRL::ComPtr<IDebugHostType>& sp_type) {
+  _bstr_t name;
+  HRESULT hr = sp_type->GetName(name.GetAddress());
+  if (!SUCCEEDED(hr)) return false;
+  if (std::string(static_cast<const char*>(name)) == kObject) return true;
+
+  WRL::ComPtr<IDebugHostSymbolEnumerator> sp_super_class_enumerator;
+  hr = sp_type->EnumerateChildren(SymbolKind::SymbolBaseClass, nullptr,
+                                  &sp_super_class_enumerator);
+  if (!SUCCEEDED(hr)) return false;
+
+  while (true) {
+    WRL::ComPtr<IDebugHostSymbol> sp_type_symbol;
+    if (sp_super_class_enumerator->GetNext(&sp_type_symbol) != S_OK) break;
+    WRL::ComPtr<IDebugHostBaseClass> sp_base_class;
+    if (FAILED(sp_type_symbol.As(&sp_base_class))) continue;
+    WRL::ComPtr<IDebugHostType> sp_base_type;
+    hr = sp_base_class->GetType(&sp_base_type);
+    if (!SUCCEEDED(hr)) continue;
+    if (DoesTypeDeriveFromObject(sp_base_type)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+WRL::ComPtr<IDebugHostType> Extension::GetV8ObjectType(
+    WRL::ComPtr<IDebugHostContext>& sp_ctx) {
+  return GetTypeFromV8Module(sp_ctx, kObjectU);
+}
+
+WRL::ComPtr<IDebugHostType> Extension::GetTypeFromV8Module(
+    WRL::ComPtr<IDebugHostContext>& sp_ctx, const char16_t* type_name) {
+  bool is_equal;
+  if (sp_v8_module_ctx_ == nullptr ||
+      !SUCCEEDED(sp_v8_module_ctx_->IsEqualTo(sp_ctx.Get(), &is_equal)) ||
+      !is_equal) {
+    // Context changed; clear the dictionary.
+    cached_v8_module_types_.clear();
+  }
+
+  GetV8Module(sp_ctx);  // Will force the correct module to load
+  if (sp_v8_module_ == nullptr) return nullptr;
+
+  auto& dictionary_entry = cached_v8_module_types_[type_name];
+  if (dictionary_entry == nullptr) {
+    const std::wstring type_name_w(reinterpret_cast<const wchar_t*>(type_name));
+    // The contract from debug_helper functions is to provide type names that
+    // would be valid if used in C++ code within the v8::internal namespace.
+    // They might be fully qualified but aren't required to be. Thus, we must
+    // simluate an "unqualified name lookup" here, by searching for the type
+    // starting in the innermost namespace and working outward.
+    if (SUCCEEDED(sp_v8_module_->FindTypeByName(
+            (L"v8::internal::" + type_name_w).c_str(), &dictionary_entry))) {
+      return dictionary_entry;
+    }
+    if (SUCCEEDED(sp_v8_module_->FindTypeByName((L"v8::" + type_name_w).c_str(),
+                                                &dictionary_entry))) {
+      return dictionary_entry;
+    }
+    sp_v8_module_->FindTypeByName(reinterpret_cast<PCWSTR>(type_name),
+                                  &dictionary_entry);
+  }
+  return dictionary_entry;
+}
+
+namespace {
+
+// Returns whether the given module appears to have symbols for V8 code.
+bool IsV8Module(IDebugHostModule* module) {
+  WRL::ComPtr<IDebugHostSymbol> sp_isolate_sym;
+  // The below symbol is specific to the main V8 module.
+  if (FAILED(module->FindSymbolByName(L"v8::Script::Run", &sp_isolate_sym))) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+WRL::ComPtr<IDebugHostModule> Extension::GetV8Module(
+    WRL::ComPtr<IDebugHostContext>& sp_ctx) {
+  // Return the cached version if it exists and the context is the same
+
+  // Note: Context will often have the CUSTOM flag set, which never compares
+  // equal. So for now DON'T compare by context, but by proc_id. (An API is in
+  // progress to compare by address space, which should be usable when shipped).
+  /*
+  if (sp_v8_module_ != nullptr) {
+    bool is_equal;
+    if (SUCCEEDED(sp_v8_module_ctx_->IsEqualTo(sp_ctx.Get(), &is_equal)) &&
+  is_equal) { return sp_v8_module_; } else { sp_v8_module_ = nullptr;
+      sp_v8_module_ctx_ = nullptr;
+    }
+  }
+  */
+  WRL::ComPtr<IDebugSystemObjects> sp_sys_objects;
+  ULONG proc_id = 0;
+  if (SUCCEEDED(sp_debug_control.As(&sp_sys_objects))) {
+    if (SUCCEEDED(sp_sys_objects->GetCurrentProcessSystemId(&proc_id))) {
+      if (proc_id == v8_module_proc_id_ && sp_v8_module_ != nullptr)
+        return sp_v8_module_;
+    }
+  }
+
+  // Search first for a few known module names, to avoid loading symbols for
+  // unrelated modules if we can easily avoid it. Generally, failing to find a
+  // module is fast but failing to find a symbol within a module is slow. Note
+  // that "v8" is listed first because it's highly likely to be the correct
+  // module if it exists. The others might include V8 symbols depending on the
+  // build configuration.
+  std::vector<const wchar_t*> known_names = {
+      L"v8", L"v8_for_testing", L"cctest_exe", L"chrome",
+      L"d8", L"msedge",         L"node",       L"unittests_exe"};
+  for (const wchar_t* name : known_names) {
+    WRL::ComPtr<IDebugHostModule> sp_module;
+    if (SUCCEEDED(sp_debug_host_symbols->FindModuleByName(sp_ctx.Get(), name,
+                                                          &sp_module))) {
+      if (IsV8Module(sp_module.Get())) {
+        sp_v8_module_ = sp_module;
+        sp_v8_module_ctx_ = sp_ctx;
+        v8_module_proc_id_ = proc_id;
+        return sp_v8_module_;
+      }
+    }
+  }
+
+  // Loop through all modules looking for the one that holds a known symbol.
+  WRL::ComPtr<IDebugHostSymbolEnumerator> sp_enum;
+  if (SUCCEEDED(
+          sp_debug_host_symbols->EnumerateModules(sp_ctx.Get(), &sp_enum))) {
+    HRESULT hr = S_OK;
+    while (true) {
+      WRL::ComPtr<IDebugHostSymbol> sp_mod_sym;
+      hr = sp_enum->GetNext(&sp_mod_sym);
+      // hr == E_BOUNDS : hit the end of the enumerator
+      // hr == E_ABORT  : a user interrupt was requested
+      if (FAILED(hr)) break;
+      WRL::ComPtr<IDebugHostModule> sp_module;
+      if (SUCCEEDED(sp_mod_sym.As(&sp_module))) /* should always succeed */
+      {
+        if (IsV8Module(sp_module.Get())) {
+          sp_v8_module_ = sp_module;
+          sp_v8_module_ctx_ = sp_ctx;
+          v8_module_proc_id_ = proc_id;
+          break;
+        }
+      }
+    }
+  }
+  // This will be the located module, or still nullptr if above fails
+  return sp_v8_module_;
+}
+
+Extension::Extension() = default;
+
+HRESULT Extension::Initialize() {
+  // Create an instance of the DataModel parent for v8::internal::Object types.
+  auto object_data_model{WRL::Make<V8ObjectDataModel>()};
+  RETURN_IF_FAIL(sp_data_model_manager->CreateDataModelObject(
+      object_data_model.Get(), &sp_object_data_model_));
+  RETURN_IF_FAIL(sp_object_data_model_->SetConcept(
+      __uuidof(IStringDisplayableConcept),
+      static_cast<IStringDisplayableConcept*>(object_data_model.Get()),
+      nullptr));
+  RETURN_IF_FAIL(sp_object_data_model_->SetConcept(
+      __uuidof(IDynamicKeyProviderConcept),
+      static_cast<IDynamicKeyProviderConcept*>(object_data_model.Get()),
+      nullptr));
+
+  // Register that parent model for all known types of V8 object.
+  std::vector<std::u16string> object_class_names = ListObjectClasses();
+  object_class_names.push_back(kObjectU);
+  object_class_names.push_back(kTaggedValueU);
+  for (const std::u16string& name : object_class_names) {
+    WRL::ComPtr<IDebugHostTypeSignature> sp_object_type_signature;
+    RETURN_IF_FAIL(sp_debug_host_symbols->CreateTypeSignature(
+        reinterpret_cast<const wchar_t*>(name.c_str()), nullptr,
+        &sp_object_type_signature));
+    RETURN_IF_FAIL(sp_data_model_manager->RegisterModelForTypeSignature(
+        sp_object_type_signature.Get(), sp_object_data_model_.Get()));
+    registered_object_types_.push_back(sp_object_type_signature);
+  }
+
+  // Create an instance of the DataModel parent for custom iterable fields.
+  auto indexed_field_model{WRL::Make<IndexedFieldParent>()};
+  RETURN_IF_FAIL(sp_data_model_manager->CreateDataModelObject(
+      indexed_field_model.Get(), &sp_indexed_field_model_));
+  RETURN_IF_FAIL(sp_indexed_field_model_->SetConcept(
+      __uuidof(IIndexableConcept),
+      static_cast<IIndexableConcept*>(indexed_field_model.Get()), nullptr));
+  RETURN_IF_FAIL(sp_indexed_field_model_->SetConcept(
+      __uuidof(IIterableConcept),
+      static_cast<IIterableConcept*>(indexed_field_model.Get()), nullptr));
+
+  // Create an instance of the DataModel parent class for v8::Local<*> types.
+  auto local_data_model{WRL::Make<V8LocalDataModel>()};
+  RETURN_IF_FAIL(sp_data_model_manager->CreateDataModelObject(
+      local_data_model.Get(), &sp_local_data_model_));
+
+  // Register that parent model for all known types that act like v8::Local.
+  std::vector<const wchar_t*> handle_class_names = {
+      L"v8::Local<*>", L"v8::MaybeLocal<*>", L"v8::internal::Handle<*>",
+      L"v8::internal::MaybeHandle<*>"};
+  for (const wchar_t* name : handle_class_names) {
+    WRL::ComPtr<IDebugHostTypeSignature> signature;
+    RETURN_IF_FAIL(
+        sp_debug_host_symbols->CreateTypeSignature(name, nullptr, &signature));
+    RETURN_IF_FAIL(sp_data_model_manager->RegisterModelForTypeSignature(
+        signature.Get(), sp_local_data_model_.Get()));
+    registered_handle_types_.push_back(signature);
+  }
+
+  // Add the 'Value' property to the parent model.
+  auto local_value_property{WRL::Make<V8LocalValueProperty>()};
+  WRL::ComPtr<IModelObject> sp_local_value_property_model;
+  RETURN_IF_FAIL(CreateProperty(sp_data_model_manager.Get(),
+                                local_value_property.Get(),
+                                &sp_local_value_property_model));
+  RETURN_IF_FAIL(sp_local_data_model_->SetKey(
+      L"Value", sp_local_value_property_model.Get(), nullptr));
+
+  // Register all function aliases.
+  std::vector<std::pair<const wchar_t*, WRL::ComPtr<IModelMethod>>> functions =
+      {{pcur_isolate, WRL::Make<CurrIsolateAlias>()},
+       {plist_chunks, WRL::Make<ListChunksAlias>()},
+       {pv8_object, WRL::Make<InspectV8ObjectMethod>()}};
+  for (const auto& function : functions) {
+    WRL::ComPtr<IModelObject> method;
+    RETURN_IF_FAIL(CreateMethod(sp_data_model_manager.Get(),
+                                function.second.Get(), &method));
+    RETURN_IF_FAIL(sp_debug_host_extensibility->CreateFunctionAlias(
+        function.first, method.Get()));
+  }
+
+  // Register a handler for supplying stack frame locals. It has to override the
+  // getter functions for "LocalVariables" and "Parameters".
+  WRL::ComPtr<IModelObject> stack_frame;
+  RETURN_IF_FAIL(sp_data_model_manager->AcquireNamedModel(
+      L"Debugger.Models.StackFrame", &stack_frame));
+  RETURN_IF_FAIL(OverrideLocalsGetter(stack_frame.Get(), L"LocalVariables",
+                                      /*is_parameters=*/false));
+  RETURN_IF_FAIL(OverrideLocalsGetter(stack_frame.Get(), L"Parameters",
+                                      /*is_parameters=*/true));
+
+  return S_OK;
+}
+
+HRESULT Extension::OverrideLocalsGetter(IModelObject* stack_frame,
+                                        const wchar_t* key_name,
+                                        bool is_parameters) {
+  WRL::ComPtr<IModelObject> original_boxed_getter;
+  WRL::ComPtr<IKeyStore> original_getter_metadata;
+  RETURN_IF_FAIL(stack_frame->GetKey(key_name, &original_boxed_getter,
+                                     &original_getter_metadata));
+  WRL::ComPtr<IModelPropertyAccessor> original_getter;
+  RETURN_IF_FAIL(UnboxProperty(original_boxed_getter.Get(), &original_getter));
+  auto new_getter{WRL::Make<V8LocalVariables>(original_getter, is_parameters)};
+  WRL::ComPtr<IModelObject> new_boxed_getter;
+  RETURN_IF_FAIL(CreateProperty(sp_data_model_manager.Get(), new_getter.Get(),
+                                &new_boxed_getter));
+  RETURN_IF_FAIL(stack_frame->SetKey(key_name, new_boxed_getter.Get(),
+                                     original_getter_metadata.Get()));
+  overridden_properties_.push_back(
+      {stack_frame, reinterpret_cast<const char16_t*>(key_name),
+       original_boxed_getter.Get(), original_getter_metadata.Get()});
+  return S_OK;
+}
+
+Extension::PropertyOverride::PropertyOverride() = default;
+Extension::PropertyOverride::PropertyOverride(IModelObject* parent,
+                                              std::u16string key_name,
+                                              IModelObject* original_value,
+                                              IKeyStore* original_metadata)
+    : parent(parent),
+      key_name(std::move(key_name)),
+      original_value(original_value),
+      original_metadata(original_metadata) {}
+Extension::PropertyOverride::~PropertyOverride() = default;
+Extension::PropertyOverride::PropertyOverride(const PropertyOverride&) =
+    default;
+Extension::PropertyOverride& Extension::PropertyOverride::operator=(
+    const PropertyOverride&) = default;
+
+Extension::~Extension() {
+  sp_debug_host_extensibility->DestroyFunctionAlias(pcur_isolate);
+  sp_debug_host_extensibility->DestroyFunctionAlias(plist_chunks);
+  sp_debug_host_extensibility->DestroyFunctionAlias(pv8_object);
+
+  for (const auto& registered : registered_object_types_) {
+    sp_data_model_manager->UnregisterModelForTypeSignature(
+        sp_object_data_model_.Get(), registered.Get());
+  }
+  for (const auto& registered : registered_handle_types_) {
+    sp_data_model_manager->UnregisterModelForTypeSignature(
+        sp_local_data_model_.Get(), registered.Get());
+  }
+
+  for (const auto& override : overridden_properties_) {
+    override.parent->SetKey(
+        reinterpret_cast<const wchar_t*>(override.key_name.c_str()),
+        override.original_value.Get(), override.original_metadata.Get());
+  }
+}
diff --git a/deps/v8/tools/v8windbg/src/v8windbg-extension.h b/deps/v8/tools/v8windbg/src/v8windbg-extension.h
new file mode 100644
index 0000000000..d54f43c847
--- /dev/null
+++ b/deps/v8/tools/v8windbg/src/v8windbg-extension.h
@@ -0,0 +1,81 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_SRC_V8WINDBG_EXTENSION_H_
+#define V8_TOOLS_V8WINDBG_SRC_V8WINDBG_EXTENSION_H_
+
+#include <memory>
+#include <unordered_map>
+#include <vector>
+
+#include "tools/v8windbg/base/utilities.h"
+
+// Responsible for initializing and uninitializing the extension. Also provides
+// various convenience functions.
+class Extension {
+ public:
+  Extension();
+  HRESULT Initialize();
+  ~Extension();
+  WRL::ComPtr<IDebugHostModule> GetV8Module(
+      WRL::ComPtr<IDebugHostContext>& sp_ctx);
+  WRL::ComPtr<IDebugHostType> GetTypeFromV8Module(
+      WRL::ComPtr<IDebugHostContext>& sp_ctx, const char16_t* type_name);
+  WRL::ComPtr<IDebugHostType> GetV8ObjectType(
+      WRL::ComPtr<IDebugHostContext>& sp_ctx);
+  void TryRegisterType(WRL::ComPtr<IDebugHostType>& sp_type,
+                       std::u16string type_name);
+  bool DoesTypeDeriveFromObject(const WRL::ComPtr<IDebugHostType>& sp_type);
+  static Extension* Current() { return current_extension_.get(); }
+  static void SetExtension(std::unique_ptr<Extension> new_extension) {
+    current_extension_ = std::move(new_extension);
+  }
+
+  // Returns the parent model for instances of v8::internal::Object and similar
+  // classes, which contain as their first and only field a tagged V8 value.
+  IModelObject* GetObjectDataModel() { return sp_object_data_model_.Get(); }
+
+  // Returns the parent model that provides indexing support for fields that
+  // contain arrays of something more complicated than basic native types.
+  IModelObject* GetIndexedFieldDataModel() {
+    return sp_indexed_field_model_.Get();
+  }
+
+ private:
+  HRESULT OverrideLocalsGetter(IModelObject* parent, const wchar_t* key_name,
+                               bool is_parameters);
+
+  // A property that has been overridden by this extension. The original value
+  // must be put back in place during ~Extension.
+  struct PropertyOverride {
+    PropertyOverride();
+    PropertyOverride(IModelObject* parent, std::u16string key_name,
+                     IModelObject* original_value,
+                     IKeyStore* original_metadata);
+    ~PropertyOverride();
+    PropertyOverride(const PropertyOverride&);
+    PropertyOverride& operator=(const PropertyOverride&);
+    WRL::ComPtr<IModelObject> parent;
+    std::u16string key_name;
+    WRL::ComPtr<IModelObject> original_value;
+    WRL::ComPtr<IKeyStore> original_metadata;
+  };
+
+  static std::unique_ptr<Extension> current_extension_;
+
+  WRL::ComPtr<IModelObject> sp_object_data_model_;
+  WRL::ComPtr<IModelObject> sp_local_data_model_;
+  WRL::ComPtr<IModelObject> sp_indexed_field_model_;
+
+  WRL::ComPtr<IDebugHostModule> sp_v8_module_;
+  std::unordered_map<std::u16string, WRL::ComPtr<IDebugHostType>>
+      cached_v8_module_types_;
+  std::vector<WRL::ComPtr<IDebugHostTypeSignature>> registered_object_types_;
+  std::vector<WRL::ComPtr<IDebugHostTypeSignature>> registered_handle_types_;
+  std::vector<PropertyOverride> overridden_properties_;
+  WRL::ComPtr<IDebugHostContext> sp_v8_module_ctx_;
+  ULONG v8_module_proc_id_;
+};
+
+#endif  // V8_TOOLS_V8WINDBG_SRC_V8WINDBG_EXTENSION_H_
diff --git a/deps/v8/tools/v8windbg/test/debug-callbacks.cc b/deps/v8/tools/v8windbg/test/debug-callbacks.cc
new file mode 100644
index 0000000000..0b11195bdb
--- /dev/null
+++ b/deps/v8/tools/v8windbg/test/debug-callbacks.cc
@@ -0,0 +1,94 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/v8windbg/test/debug-callbacks.h"
+
+namespace v8 {
+namespace internal {
+namespace v8windbg_test {
+
+MyOutput::MyOutput(WRL::ComPtr<IDebugClient5> p_client) : p_client_(p_client) {
+  p_client_->SetOutputCallbacks(this);
+}
+
+MyOutput::~MyOutput() { p_client_->SetOutputCallbacks(nullptr); }
+
+HRESULT __stdcall MyOutput::QueryInterface(REFIID InterfaceId,
+                                           PVOID* Interface) {
+  return E_NOTIMPL;
+}
+ULONG __stdcall MyOutput::AddRef(void) { return 0; }
+ULONG __stdcall MyOutput::Release(void) { return 0; }
+HRESULT __stdcall MyOutput::Output(ULONG Mask, PCSTR Text) {
+  if (Mask & DEBUG_OUTPUT_NORMAL) {
+    log_ += Text;
+  }
+  return S_OK;
+}
+
+HRESULT __stdcall MyCallback::QueryInterface(REFIID InterfaceId,
+                                             PVOID* Interface) {
+  return E_NOTIMPL;
+}
+ULONG __stdcall MyCallback::AddRef(void) { return S_OK; }
+ULONG __stdcall MyCallback::Release(void) { return S_OK; }
+HRESULT __stdcall MyCallback::GetInterestMask(PULONG Mask) {
+  *Mask = DEBUG_EVENT_BREAKPOINT | DEBUG_EVENT_CREATE_PROCESS;
+  return S_OK;
+}
+HRESULT __stdcall MyCallback::Breakpoint(PDEBUG_BREAKPOINT Bp) {
+  ULONG64 bp_offset;
+  HRESULT hr = Bp->GetOffset(&bp_offset);
+  if (FAILED(hr)) return hr;
+
+  // Break on breakpoints? Seems reasonable.
+  return DEBUG_STATUS_BREAK;
+}
+HRESULT __stdcall MyCallback::Exception(PEXCEPTION_RECORD64 Exception,
+                                        ULONG FirstChance) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::CreateThread(ULONG64 Handle, ULONG64 DataOffset,
+                                           ULONG64 StartOffset) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::ExitThread(ULONG ExitCode) { return E_NOTIMPL; }
+HRESULT __stdcall MyCallback::ExitProcess(ULONG ExitCode) { return E_NOTIMPL; }
+HRESULT __stdcall MyCallback::LoadModule(ULONG64 ImageFileHandle,
+                                         ULONG64 BaseOffset, ULONG ModuleSize,
+                                         PCSTR ModuleName, PCSTR ImageName,
+                                         ULONG CheckSum, ULONG TimeDateStamp) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::UnloadModule(PCSTR ImageBaseName,
+                                           ULONG64 BaseOffset) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::SystemError(ULONG Error, ULONG Level) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::SessionStatus(ULONG Status) { return E_NOTIMPL; }
+HRESULT __stdcall MyCallback::ChangeDebuggeeState(ULONG Flags,
+                                                  ULONG64 Argument) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::ChangeEngineState(ULONG Flags, ULONG64 Argument) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::ChangeSymbolState(ULONG Flags, ULONG64 Argument) {
+  return E_NOTIMPL;
+}
+HRESULT __stdcall MyCallback::CreateProcessW(
+    ULONG64 ImageFileHandle, ULONG64 Handle, ULONG64 BaseOffset,
+    ULONG ModuleSize, PCSTR ModuleName, PCSTR ImageName, ULONG CheckSum,
+    ULONG TimeDateStamp, ULONG64 InitialThreadHandle, ULONG64 ThreadDataOffset,
+    ULONG64 StartOffset) {
+  // Should fire once the target process is launched. Break to create
+  // breakpoints, etc.
+  return DEBUG_STATUS_BREAK;
+}
+
+}  // namespace v8windbg_test
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/tools/v8windbg/test/debug-callbacks.h b/deps/v8/tools/v8windbg/test/debug-callbacks.h
new file mode 100644
index 0000000000..8855d6ffbc
--- /dev/null
+++ b/deps/v8/tools/v8windbg/test/debug-callbacks.h
@@ -0,0 +1,90 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_TEST_DEBUG_CALLBACKS_H_
+#define V8_TOOLS_V8WINDBG_TEST_DEBUG_CALLBACKS_H_
+
+#if !defined(UNICODE) || !defined(_UNICODE)
+#error Unicode not defined
+#endif
+
+#include <DbgEng.h>
+#include <DbgModel.h>
+#include <Windows.h>
+#include <crtdbg.h>
+#include <pathcch.h>
+#include <wrl/client.h>
+
+#include <string>
+
+namespace WRL = Microsoft::WRL;
+
+namespace v8 {
+namespace internal {
+namespace v8windbg_test {
+
+class MyOutput : public IDebugOutputCallbacks {
+ public:
+  MyOutput(WRL::ComPtr<IDebugClient5> p_client);
+  ~MyOutput();
+  MyOutput(const MyOutput&) = delete;
+  MyOutput& operator=(const MyOutput&) = delete;
+
+  // Inherited via IDebugOutputCallbacks
+  HRESULT __stdcall QueryInterface(REFIID InterfaceId,
+                                   PVOID* Interface) override;
+  ULONG __stdcall AddRef(void) override;
+  ULONG __stdcall Release(void) override;
+  HRESULT __stdcall Output(ULONG Mask, PCSTR Text) override;
+
+  const std::string& GetLog() const { return log_; }
+  void ClearLog() { log_.clear(); }
+
+ private:
+  WRL::ComPtr<IDebugClient5> p_client_;
+  std::string log_;
+};
+
+// For return values, see:
+// https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/debug-status-xxx
+class MyCallback : public IDebugEventCallbacks {
+ public:
+  // Inherited via IDebugEventCallbacks
+  HRESULT __stdcall QueryInterface(REFIID InterfaceId,
+                                   PVOID* Interface) override;
+  ULONG __stdcall AddRef(void) override;
+  ULONG __stdcall Release(void) override;
+  HRESULT __stdcall GetInterestMask(PULONG Mask) override;
+  HRESULT __stdcall Breakpoint(PDEBUG_BREAKPOINT Bp) override;
+  HRESULT __stdcall Exception(PEXCEPTION_RECORD64 Exception,
+                              ULONG FirstChance) override;
+  HRESULT __stdcall CreateThread(ULONG64 Handle, ULONG64 DataOffset,
+                                 ULONG64 StartOffset) override;
+  HRESULT __stdcall ExitThread(ULONG ExitCode) override;
+  HRESULT __stdcall ExitProcess(ULONG ExitCode) override;
+  HRESULT __stdcall LoadModule(ULONG64 ImageFileHandle, ULONG64 BaseOffset,
+                               ULONG ModuleSize, PCSTR ModuleName,
+                               PCSTR ImageName, ULONG CheckSum,
+                               ULONG TimeDateStamp) override;
+  HRESULT __stdcall UnloadModule(PCSTR ImageBaseName,
+                                 ULONG64 BaseOffset) override;
+  HRESULT __stdcall SystemError(ULONG Error, ULONG Level) override;
+  HRESULT __stdcall SessionStatus(ULONG Status) override;
+  HRESULT __stdcall ChangeDebuggeeState(ULONG Flags, ULONG64 Argument) override;
+  HRESULT __stdcall ChangeEngineState(ULONG Flags, ULONG64 Argument) override;
+  HRESULT __stdcall ChangeSymbolState(ULONG Flags, ULONG64 Argument) override;
+  HRESULT __stdcall CreateProcessW(ULONG64 ImageFileHandle, ULONG64 Handle,
+                                   ULONG64 BaseOffset, ULONG ModuleSize,
+                                   PCSTR ModuleName, PCSTR ImageName,
+                                   ULONG CheckSum, ULONG TimeDateStamp,
+                                   ULONG64 InitialThreadHandle,
+                                   ULONG64 ThreadDataOffset,
+                                   ULONG64 StartOffset) override;
+};
+
+}  // namespace v8windbg_test
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TOOLS_V8WINDBG_TEST_DEBUG_CALLBACKS_H_
diff --git a/deps/v8/tools/v8windbg/test/script.js b/deps/v8/tools/v8windbg/test/script.js
new file mode 100644
index 0000000000..6ec21e0bc4
--- /dev/null
+++ b/deps/v8/tools/v8windbg/test/script.js
@@ -0,0 +1,14 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function a() {
+  JSON.stringify({firstProp: 12345, secondProp: null}, function replacer() {});
+}
+
+function b() {
+  var hello = 'hello';
+  a();
+}
+
+b();
diff --git a/deps/v8/tools/v8windbg/test/v8windbg-test.cc b/deps/v8/tools/v8windbg/test/v8windbg-test.cc
new file mode 100644
index 0000000000..59414f341d
--- /dev/null
+++ b/deps/v8/tools/v8windbg/test/v8windbg-test.cc
@@ -0,0 +1,243 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstdio>
+#include <exception>
+#include <vector>
+
+#include "src/base/logging.h"
+#include "tools/v8windbg/test/debug-callbacks.h"
+
+// See the docs at
+// https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/using-the-debugger-engine-api
+
+namespace v8 {
+namespace internal {
+namespace v8windbg_test {
+
+namespace {
+
+// Loads a named extension library upon construction and unloads it upon
+// destruction.
+class LoadExtensionScope {
+ public:
+  LoadExtensionScope(WRL::ComPtr<IDebugControl4> p_debug_control,
+                     std::wstring extension_path)
+      : p_debug_control_(p_debug_control),
+        extension_path_(std::move(extension_path)) {
+    p_debug_control->AddExtensionWide(extension_path_.c_str(), 0, &ext_handle_);
+    // HACK: Below fails, but is required for the extension to actually
+    // initialize. Just the AddExtension call doesn't actually load and
+    // initialize it.
+    p_debug_control->CallExtension(ext_handle_, "Foo", "Bar");
+  }
+  ~LoadExtensionScope() {
+    // Let the extension uninitialize so it can deallocate memory, meaning any
+    // reported memory leaks should be real bugs.
+    p_debug_control_->RemoveExtension(ext_handle_);
+  }
+
+ private:
+  LoadExtensionScope(const LoadExtensionScope&) = delete;
+  LoadExtensionScope& operator=(const LoadExtensionScope&) = delete;
+  WRL::ComPtr<IDebugControl4> p_debug_control_;
+  ULONG64 ext_handle_;
+  // This string is part of the heap snapshot when the extension loads, so keep
+  // it alive until after the extension unloads and checks for any heap changes.
+  std::wstring extension_path_;
+};
+
+// Initializes COM upon construction and uninitializes it upon destruction.
+class ComScope {
+ public:
+  ComScope() { hr_ = CoInitializeEx(nullptr, COINIT_MULTITHREADED); }
+  ~ComScope() {
+    // "To close the COM library gracefully on a thread, each successful call to
+    // CoInitialize or CoInitializeEx, including any call that returns S_FALSE,
+    // must be balanced by a corresponding call to CoUninitialize."
+    // https://docs.microsoft.com/en-us/windows/win32/api/combaseapi/nf-combaseapi-coinitializeex
+    if (SUCCEEDED(hr_)) {
+      CoUninitialize();
+    }
+  }
+  HRESULT hr() { return hr_; }
+
+ private:
+  HRESULT hr_;
+};
+
+// Sets a breakpoint. Returns S_OK if the function name resolved successfully
+// and the breakpoint is in a non-deferred state.
+HRESULT SetBreakpoint(WRL::ComPtr<IDebugControl4> p_debug_control,
+                      const char* function_name) {
+  WRL::ComPtr<IDebugBreakpoint> bp;
+  HRESULT hr =
+      p_debug_control->AddBreakpoint(DEBUG_BREAKPOINT_CODE, DEBUG_ANY_ID, &bp);
+  if (FAILED(hr)) return hr;
+  hr = bp->SetOffsetExpression(function_name);
+  if (FAILED(hr)) return hr;
+  hr = bp->AddFlags(DEBUG_BREAKPOINT_ENABLED);
+  if (FAILED(hr)) return hr;
+
+  // Check whether the symbol could be found.
+  uint64_t offset;
+  hr = bp->GetOffset(&offset);
+  return hr;
+}
+
+// Sets a breakpoint. Depending on the build configuration, the function might
+// be in the v8 or d8 module, so this function tries to set both.
+HRESULT SetBreakpointInV8OrD8(WRL::ComPtr<IDebugControl4> p_debug_control,
+                              const std::string& function_name) {
+  // Component builds call the V8 module "v8". Try this first, because there is
+  // also a module named "d8" or "d8_exe" where we should avoid attempting to
+  // set a breakpoint.
+  HRESULT hr = SetBreakpoint(p_debug_control, ("v8!" + function_name).c_str());
+  if (SUCCEEDED(hr)) return hr;
+
+  // x64 release builds call it "d8".
+  hr = SetBreakpoint(p_debug_control, ("d8!" + function_name).c_str());
+  if (SUCCEEDED(hr)) return hr;
+
+  // x86 release builds call it "d8_exe".
+  return SetBreakpoint(p_debug_control, ("d8_exe!" + function_name).c_str());
+}
+
+void RunAndCheckOutput(const char* friendly_name, const char* command,
+                       std::vector<const char*> expected_substrings,
+                       MyOutput* output, IDebugControl4* p_debug_control) {
+  output->ClearLog();
+  CHECK(SUCCEEDED(p_debug_control->Execute(DEBUG_OUTCTL_ALL_CLIENTS, command,
+                                           DEBUG_EXECUTE_ECHO)));
+  for (const char* expected : expected_substrings) {
+    CHECK(output->GetLog().find(expected) != std::string::npos);
+  }
+}
+
+}  // namespace
+
+void RunTests() {
+  // Initialize COM... Though it doesn't seem to matter if you don't!
+  ComScope com_scope;
+  CHECK(SUCCEEDED(com_scope.hr()));
+
+  // Get the file path of the module containing this test function. It should be
+  // in the output directory alongside the data dependencies required by this
+  // test (d8.exe, v8windbg.dll, and v8windbg-test-script.js).
+  HMODULE module = nullptr;
+  bool success =
+      GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
+                            GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                        reinterpret_cast<LPCWSTR>(&RunTests), &module);
+  CHECK(success);
+  wchar_t this_module_path[MAX_PATH];
+  DWORD path_size = GetModuleFileName(module, this_module_path, MAX_PATH);
+  CHECK(path_size != 0);
+  HRESULT hr = PathCchRemoveFileSpec(this_module_path, MAX_PATH);
+  CHECK(SUCCEEDED(hr));
+
+  // Get the Debug client
+  WRL::ComPtr<IDebugClient5> p_client;
+  hr = DebugCreate(__uuidof(IDebugClient5), &p_client);
+  CHECK(SUCCEEDED(hr));
+
+  WRL::ComPtr<IDebugSymbols3> p_symbols;
+  hr = p_client->QueryInterface(__uuidof(IDebugSymbols3), &p_symbols);
+  CHECK(SUCCEEDED(hr));
+
+  // Symbol loading fails if the pdb is in the same folder as the exe, but it's
+  // not on the path.
+  hr = p_symbols->SetSymbolPathWide(this_module_path);
+  CHECK(SUCCEEDED(hr));
+
+  // Set the event callbacks
+  MyCallback callback;
+  hr = p_client->SetEventCallbacks(&callback);
+  CHECK(SUCCEEDED(hr));
+
+  // Launch the process with the debugger attached
+  std::wstring command_line =
+      std::wstring(L"\"") + this_module_path + L"\\d8.exe\" \"" +
+      this_module_path + L"\\obj\\tools\\v8windbg\\v8windbg-test-script.js\"";
+  DEBUG_CREATE_PROCESS_OPTIONS proc_options;
+  proc_options.CreateFlags = DEBUG_PROCESS;
+  proc_options.EngCreateFlags = 0;
+  proc_options.VerifierFlags = 0;
+  proc_options.Reserved = 0;
+  hr = p_client->CreateProcessWide(
+      0, const_cast<wchar_t*>(command_line.c_str()), DEBUG_PROCESS);
+  CHECK(SUCCEEDED(hr));
+
+  // Wait for the attach event
+  WRL::ComPtr<IDebugControl4> p_debug_control;
+  hr = p_client->QueryInterface(__uuidof(IDebugControl4), &p_debug_control);
+  CHECK(SUCCEEDED(hr));
+  hr = p_debug_control->WaitForEvent(0, INFINITE);
+  CHECK(SUCCEEDED(hr));
+
+  // Break again after non-delay-load modules are loaded.
+  hr = p_debug_control->AddEngineOptions(DEBUG_ENGOPT_INITIAL_BREAK);
+  CHECK(SUCCEEDED(hr));
+  hr = p_debug_control->WaitForEvent(0, INFINITE);
+  CHECK(SUCCEEDED(hr));
+
+  // Set a breakpoint in a C++ function called by the script.
+  hr = SetBreakpointInV8OrD8(p_debug_control, "v8::internal::JsonStringify");
+  CHECK(SUCCEEDED(hr));
+
+  hr = p_debug_control->SetExecutionStatus(DEBUG_STATUS_GO);
+  CHECK(SUCCEEDED(hr));
+
+  // Wait for the breakpoint.
+  hr = p_debug_control->WaitForEvent(0, INFINITE);
+  CHECK(SUCCEEDED(hr));
+
+  ULONG type, proc_id, thread_id, desc_used;
+  byte desc[1024];
+  hr = p_debug_control->GetLastEventInformation(
+      &type, &proc_id, &thread_id, nullptr, 0, nullptr,
+      reinterpret_cast<PSTR>(desc), 1024, &desc_used);
+  CHECK(SUCCEEDED(hr));
+
+  LoadExtensionScope extension_loaded(
+      p_debug_control, this_module_path + std::wstring(L"\\v8windbg.dll"));
+
+  // Set the output callbacks after the extension is loaded, so it gets
+  // destroyed before the extension unloads. This avoids reporting incorrectly
+  // reporting that the output buffer was leaked during extension teardown.
+  MyOutput output(p_client);
+
+  // Set stepping mode.
+  hr = p_debug_control->SetCodeLevel(DEBUG_LEVEL_SOURCE);
+  CHECK(SUCCEEDED(hr));
+
+  // Do some actual testing
+  RunAndCheckOutput("bitfields",
+                    "p;dx replacer.Value.shared_function_info.flags",
+                    {"kNamedExpression"}, &output, p_debug_control.Get());
+
+  RunAndCheckOutput("in-object properties",
+                    "dx object.Value.@\"in-object properties\"[1]",
+                    {"NullValue", "Oddball"}, &output, p_debug_control.Get());
+
+  RunAndCheckOutput(
+      "arrays of structs",
+      "dx object.Value.map.instance_descriptors.descriptors[1].key",
+      {"\"secondProp\"", "SeqOneByteString"}, &output, p_debug_control.Get());
+
+  RunAndCheckOutput(
+      "local variables",
+      "dx -r1 @$curthread.Stack.Frames.Where(f => "
+      "f.ToDisplayString().Contains(\"InterpreterEntryTrampoline\")).Skip(1)."
+      "First().LocalVariables.@\"memory interpreted as Objects\"",
+      {"\"hello\""}, &output, p_debug_control.Get());
+
+  // Detach before exiting
+  hr = p_client->DetachProcesses();
+  CHECK(SUCCEEDED(hr));
+}
+
+}  // namespace v8windbg_test
+}  // namespace internal
+}  // namespace v8
diff --git a/deps/v8/tools/v8windbg/test/v8windbg-test.h b/deps/v8/tools/v8windbg/test/v8windbg-test.h
new file mode 100644
index 0000000000..48a845470d
--- /dev/null
+++ b/deps/v8/tools/v8windbg/test/v8windbg-test.h
@@ -0,0 +1,18 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_TOOLS_V8WINDBG_TEST_V8WINDBG_TEST_H_
+#define V8_TOOLS_V8WINDBG_TEST_V8WINDBG_TEST_H_
+
+namespace v8 {
+namespace internal {
+namespace v8windbg_test {
+
+void RunTests();
+
+}
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TOOLS_V8WINDBG_TEST_V8WINDBG_TEST_H_
diff --git a/deps/v8/tools/whitespace.txt b/deps/v8/tools/whitespace.txt
index e55c9c427d..482c695b65 100644
--- a/deps/v8/tools/whitespace.txt
+++ b/deps/v8/tools/whitespace.txt
@@ -7,10 +7,10 @@ A Smi balks into a war and says:
 The doubles heard this and started to unbox.
 The Smi looked at them when a crazy v8-autoroll account showed up...
 The autoroller bought a round of Himbeerbrause. Suddenly.....
-The bartender starts to shake the bottles.....................
-I can't add trailing whitespaces, so I'm adding this line...
+The bartender starts to shake the bottles......................
+I can't add trailing whitespaces, so I'm adding this line.....
 I'm starting to think that just adding trailing whitespaces might not be bad.
 
-Because whitespaces are not that funny.....
+Because whitespaces are not that funny......
 Today's answer to life the universe and everything is 12950!
 Today's answer to life the universe and everything is 6727!