[NFC][sanitizer] Add class to track thread arg and retval

We need something to keep arg and retval pointers for leak checking.
Pointers should keept alive even after thread exited, until the thread
is detached or joined.
We should not put this logic into ThreadRegistry as we need the the
same for the ThreadList of HWASAN.

Reviewed By: thurston

Differential Revision: https://reviews.llvm.org/D150104