[WASM_WORKERS] Fix UB in pthread_mutex with debug+hybrid builds in pthread_mutex_unlock.c

[stephenduong1004]

Follow-up of #26673

[sbc100]

thanks @stephenduong1004 !

[sbc100]

Actually I'm not so sure about this. IIUC its only really possible to make PTHREAD_MUTEX_NORMAL work with this hack.

Other types of mutex rely on things like self->robust_list.

Are you trying to make mutex types other than PTHREAD_MUTEX_NORMAL work when called from wasm workers?

[stephenduong1004]

I think the mismatch between pthread_mutex_unlock.c and pthread_mutex_trylock.c https://github.com/emscripten-core/emscripten/pull/26673/changes#diff-b6d40570bfd7b8bba0fc45e0956292fb0dfffa5d0faee1e3be198a2e34157845 is causing some errors in hybrid mode. I am not sure if this is the best approach...

[sbc100]

I think the mismatch between pthread_mutex_unlock.c and pthread_mutex_trylock.c https://github.com/emscripten-core/emscripten/pull/26673/changes#diff-b6d40570bfd7b8bba0fc45e0956292fb0dfffa5d0faee1e3be198a2e34157845 is causing some errors in hybrid mode. I am not sure if this is the best approach...

Are you able to config if this fix address your issues?

It seems odd that it would because if your program is using anything other than PTHREAD_MUTEX_NORMAL them I think it will be hitting undefined behaviour with or without this patch.