deps: backport 39642fa from upstream V8

This is an almost clean cherry-pick of the original commit. The only
conflict was related to a rename of an internal class.

Original commit message:

    [async-await] (simpler) fix for Return in try/finally in async functions

    Alternative approach to https://codereview.chromium.org/2667983004/, which
    does not depend on implicit control flow changes from
    https://codereview.chromium.org/2664083002

    - Remove handling for `async function` from Parser::RewriteReturn(). This functionality
    is moved to BytecodeGenerator::BuildAsyncReturn(). This ensures that promise resolution
    is deferred until all finally blocks are evaluated fully.

    - Add a new deferred command (CMD_ASYNC_RETURN), which instructs ControlScope to
    generate return code using BuildAsyncReturn rather than BuildReturn.

    - Parser has a new `NewReturnStatement()` helper which determines what type of return
    statement to generate based on the type of function.

    BUG=v8:5896, v8:4483
    R=littledan@chromium.org, neis@chromium.org, rmcilroy@chromium.org, adamk@chromium.org, gsathya@chromium.org

    Review-Url: https://codereview.chromium.org/2685683002
    Cr-Commit-Position: refs/heads/master@{#43104}

Fixes: https://github.com/nodejs/node/issues/11960
PR-URL: https://github.com/nodejs/node/pull/11752
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/deps/v8/src/ast/ast.h b/deps/v8/src/ast/ast.h
index af561e0a3f..0cf20b0e4c 100644
--- a/deps/v8/src/ast/ast.h
+++ b/deps/v8/src/ast/ast.h
@@ -895,17 +895,25 @@ class BreakStatement final : public JumpStatement {
 
 class ReturnStatement final : public JumpStatement {
  public:
+  enum Type { kNormal, kAsyncReturn };
   Expression* expression() const { return expression_; }
 
   void set_expression(Expression* e) { expression_ = e; }
+  Type type() const { return TypeField::decode(bit_field_); }
+  bool is_async_return() const { return type() == kAsyncReturn; }
 
  private:
   friend class AstNodeFactory;
 
-  ReturnStatement(Expression* expression, int pos)
-      : JumpStatement(pos, kReturnStatement), expression_(expression) {}
+  ReturnStatement(Expression* expression, Type type, int pos)
+      : JumpStatement(pos, kReturnStatement), expression_(expression) {
+    bit_field_ |= TypeField::encode(type);
+  }
 
   Expression* expression_;
+
+  class TypeField
+      : public BitField<Type, JumpStatement::kNextBitFieldIndex, 1> {};
 };
 
 
@@ -3217,7 +3225,13 @@ class AstNodeFactory final BASE_EMBEDDED {
   }
 
   ReturnStatement* NewReturnStatement(Expression* expression, int pos) {
-    return new (zone_) ReturnStatement(expression, pos);
+    return new (zone_)
+        ReturnStatement(expression, ReturnStatement::kNormal, pos);
+  }
+
+  ReturnStatement* NewAsyncReturnStatement(Expression* expression, int pos) {
+    return new (zone_)
+        ReturnStatement(expression, ReturnStatement::kAsyncReturn, pos);
   }
 
   WithStatement* NewWithStatement(Scope* scope,