Build failure on main and latest Python 3.14 beta (missing mt_continue_should_break)

[thesamesam]

Bug report

Bug description:

The 3.14 branch and main both fail to build with --enable-assertions:

$ ./configure --with-assertions
$ make
[...]
gcc  -fno-strict-overflow -Wsign-compare -g -O3 -Wall    -std=c11 -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wstrict-prototypes -Werror=implicit-function-declaration -fvisibility=hidden  -I./Include/internal -I./Include/internal/mimalloc  -I. -I./Include    -fPIC -c ./Modules/_zstd/compressor.c -o Modules/_zstd/compressor.o
In file included from ./Include/Python.h:19,
                 from ./Modules/_zstd/compressor.c:15:
./Modules/_zstd/compressor.c: In function ‘compress_mt_continue_lock_held’:
./Modules/_zstd/compressor.c:547:20: error: implicit declaration of function ‘mt_continue_should_break’ [-Wimplicit-function-declaration]
  547 |             assert(mt_continue_should_break(&in, &out));
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~
make: *** [Makefile:3579: Modules/_zstd/compressor.o] Error 1

I'll send a patch now.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-134768: Fix definition of mt_continue_should_break() #134769
• [3.14] gh-134768: Fix definition of mt_continue_should_break() (GH-134769) #134916

[gpshead]

thanks!