[sanitizer] Move {,__}pthread_mutex_{lock,unlock} interceptors to tsan

These interceptors are pure forwarders for other sanitizers. Move them beside
tsan-specific pthread_mutex_{trylock,timedlock} interceptors.

While here, guard `__pthread_mutex_{lock,unlock}` (D46793) under `#if !__GLIBC_PREREQ(2, 34)`.

In glibc>=2.34 [1], `__pthread_mutex_{lock,unlock}` only have non-default-version definitions
(unversioned `__pthread_mutex_lock` causes a linker error. Program preloading is not expected).
In glibc>=2.36 [2], `dlsym(RTLD_NEXT, "__pthread_mutex_lock")` returns nullptr, so the interceptor won't work.

Fix https://github.com/llvm/llvm-project/issues/59820

[1]: https://sourceware.org/git/?p=glibc.git;a=commit;h=99f841c441feeaa9a3d97fd91bb3d6ec8073c982
[2]: https://sourceware.org/git/?p=glibc.git;a=commit;h=efa7936e4c91b1c260d03614bb26858fbb8a0204

Reviewed By: melver, vitalybuka

Differential Revision: https://reviews.llvm.org/D140957