Run "TZ=UTC0 admin/update-copyright".

This simplifies code, and helps performance in some cases (Bug#36597).
* src/lisp.h (hash_rehash_needed_p): Remove.  All uses removed.
(hash_rehash_if_needed): Remove.  All uses removed.
(struct Lisp_Hash_Table): Remove comment about rehashing hash tables.
* src/pdumper.c (thaw_hash_tables): New function.
(hash_table_thaw): New function.
(hash_table_freeze): New function.
(dump_hash_table): Simplify.
(dump_hash_table_list): New function.
(hash_table_contents): New function.
(Fdump_emacs_portable): Handle hash tables by eager rehashing.
(pdumper_load): Restore hash tables.
(init_pdumper_once): New function.

GCC has removed the -fcheck-pointer bounds option, and the Linux
kernel has also removed support for Intel MPX, so there’s no point
to keeping this debugging option within Emacs.
* src/bytecode.c (BYTE_CODE_THREADED):
* src/lisp.h (DEFINE_LISP_SYMBOL, XSYMBOL, make_lisp_symbol):
Assume __CHKP__ is not defined.
* src/ptr-bounds.h: Remove.  All uses of ptr_bounds_clip,
ptr_bounds_copy, ptr_bounds_init, ptr_bounds_set removed.

Check Lisp_Compiled objects better as they’re created,
so that the byte-code interpreter needn’t do the checks
each time it executes them.  This improved performance
of ‘make compile-always’ by 1.5% on my platform.  Also,
improve the quality of the (still-incomplete) checks, as
this is more practical now that they’re done less often.
* src/alloc.c (make_byte_code): Remove.  All uses removed.
(Fmake_byte_code): Put a better (though still incomplete)
check here instead.  Simplify by using Fvector instead
of make_uninit_vector followed by memcpy, and by using
XSETPVECTYPE instead of make_byte_code followed by XSETCOMPILED.
* src/bytecode.c (Fbyte_code): Do sanity check and conditional
translation to unibyte here instead of each time the function is
executed.
(exec_byte_code): Omit no-longer-necessary sanity and
unibyte checking.  Use SCHARS instead of SBYTES where
either will do, as SCHARS is faster.
* src/eval.c (fetch_and_exec_byte_code): New function.
(funcall_lambda): Use it.
(funcall_lambda, lambda_arity, Ffetch_bytecode):
Omit no-longer-necessary sanity checks.
(Ffetch_bytecode): Add sanity check if actually fetching.
* src/lisp.h (XSETCOMPILED): Remove.  All uses removed.
* src/lread.c (read1): Check byte-code objects more thoroughly,
albeit still incompletely, and do translation to unibyte here
instead of each time the function is executed.
(read1): Use XSETPVECYPE instead of make_byte_code.
(read_vector): Omit no-longer-necessary sanity check.

* src/buffer.h (fetch_char_advance, fetch_char_advance_no_check)
(buf_next_char_len, next_char_len, buf_prev_char_len)
(prev_char_len, inc_both, dec_both): New inline functions,
replacing the old character.h macros FETCH_CHAR_ADVANCE,
FETCH_CHAR_ADVANCE_NO_CHECK, BUF_INC_POS, INC_POS, BUF_DEC_POS,
DEC_POS, INC_BOTH, DEC_BOTH respectively.  All callers changed.
These new functions all assume buffer primitives and so need
to be here rather than in character.h.
* src/casefiddle.c (make_char_unibyte): New static function,
replacing the old MAKE_CHAR_UNIBYTE macro.  All callers changed.
(do_casify_unibyte_string): Use SINGLE_BYTE_CHAR_P instead
of open-coding it.
* src/ccl.c (GET_TRANSLATION_TABLE): New static function,
replacing the old macro of the same name.
* src/character.c (string_char): Omit 2nd arg.  3rd arg can no
longer be NULL.  All callers changed.
* src/character.h (SINGLE_BYTE_CHAR_P): Move up.
(MAKE_CHAR_UNIBYTE, MAKE_CHAR_MULTIBYTE, PREV_CHAR_BOUNDARY)
(STRING_CHAR_AND_LENGTH, STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE)
(FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE)
(FETCH_STRING_CHAR_ADVANCE_NO_CHECK, FETCH_CHAR_ADVANCE)
(FETCH_CHAR_ADVANCE_NO_CHECK, INC_POS, DEC_POS, INC_BOTH)
(DEC_BOTH, BUF_INC_POS, BUF_DEC_POS): Remove.
(make_char_multibyte): New static function, replacing
the old macro MAKE_CHAR_MULTIBYTE.  All callers changed.
(CHAR_STRING_ADVANCE): Remove; all callers changed to use
CHAR_STRING.
(NEXT_CHAR_BOUNDARY): Remove; it was unused.
(raw_prev_char_len): New inline function, replacing the
old PREV_CHAR_BOUNDARY macro.  All callers changed.
(string_char_and_length): New inline function, replacing the
old STRING_CHAR_AND_LENGTH macro.  All callers changed.
(STRING_CHAR): Rewrite in terms of string_char_and_length.
(string_char_advance): New inline function, replacing the old
STRING_CHAR_ADVANCE macro.  All callers changed.
(fetch_string_char_advance): New inline function, replacing the
old FETCH_STRING_CHAR_ADVANCE macro.  All callers changed.
(fetch_string_char_as_multibyte_advance): New inline function,
replacing the old FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE macro.
All callers changed.
(fetch_string_char_advance_no_check): New inline function,
replacing the old FETCH_STRING_CHAR_ADVANCE_NO_CHECK macro.  All
callers changed.
* src/regex-emacs.c (HEAD_ADDR_VSTRING): Remove; no longer used.
* src/syntax.c (scan_lists): Use dec_bytepos instead of
open-coding it.
* src/xdisp.c (string_char_and_length): Rename from
string_char_and_length to avoid name conflict with new function in
character.h.  All callers changed.

They have not been generated by the byte-compiler since Emacs 25.

* lisp/emacs-lisp/bytecomp.el (byte-catch, byte-condition-case):
* src/bytecode.c (BYTE_CODES, exec_byte_code):
Mark as obsolete (since Emacs 25; they were still generated in 24.4).

Run "TZ=UTC0 admin/update-copyright $(git ls-files)".

Following a suggestion by Stefan Monnier in:
https://lists.gnu.org/r/emacs-devel/2019-07/msg00530.html
* doc/lispref/hash.texi (Creating Hash, Defining Hash):
* src/fns.c (Fsxhash_eq, Fsxhash_eql, Fsxhash_equal, Fmake_hash_table):
Don’t insist that hash codes be fixnums, reverting
the recent doc changes to the contrary.
* src/bytecode.c (exec_byte_code): Special-case only the eq case,
as the others aren’t worth tuning now that we treat bignum hashes
like fixnums.
* src/fns.c (hashfn_user_defined): If the hash code is a bignum,
reduce its hash down to a fixnum.

* src/fns.c (restore_mutability)
(hash_table_user_defined_call): New functions.
(cmpfn_user_defined, hashfn_user_defined): Use them.
(make_hash_table, copy_hash_table):
Mark new hash table as mutable.
(check_mutable_hash_table): New function.
(Fclrhash, Fputhash, Fremhash): Use it instead of CHECK_IMPURE.
* src/lisp.h (struct hash_table_test): User-defined functions
now take pointers to struct Lisp_Hash_Table, not to struct
hash_table_test.  All uses changed.
(struct Lisp_Hash_Table): New member ‘mutable’.
* src/pdumper.c (dump_hash_table): Copy it.
* test/src/fns-tests.el (test-hash-function-that-mutates-hash-table):
New test, which tests for the bug.

* src/fns.c (cmpfn_eql, cmpfn_equal, cmpfn_user_defined)
(hashfn_eq, hashfn_equal, hashfn_eql, hashfn_user_defined):
* src/profiler.c (cmpfn_profiler, hashfn_profiler):
Use new calling convention where the return value is a fixnum
instead of EMACS_UINT.  While we’re at it, put the hash table
at the end, since that’s a bit simpler and generates better
code (at least on the x86-64).  All callers changed.
* src/fns.c (hash_lookup): Store fixnum rather than EMACS_UINT.
All callers changed.
(hash_put): Take a fixnum rather than an EMACS_UINT.
All callers changed.  Remove unnecessary eassert (XUFIXNUM does it).
* src/lisp.h (struct hash_table_test):
Adjust signatures of cmpfn and hashfn.