[compiler-rt] [sanitizer] Fix asserts in asan and tsan in pthread interceptors. (PR #75394)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

It's not critical for this component to mismatch join

However, it could be nice to see example why keeping the bug in the program is needed?
Obvious danger of this is thread reuse, and you are joining alive but wrong thread.
Sanitizer does not detect that, but if you hit this CHECK, it's possible.

Maybe rather introduce `detect_invalid_join` into `sanitizer_flags.inc`, set it true by default, and for let users disable it?
Would you like to do that? If not, please add TODO near the current CHECK





https://github.com/llvm/llvm-project/pull/75394