[clang] [PAC] Implement authentication for C++ member function pointers (PR #99576)

[Daniil Kovalev via cfe-commits]

https://github.com/kovdan01 commented:

LGTM with minor non-blocking nits. However, I'd prefer to wait for @asl 's review before merging the PR. I'm OK with merging whenever @asl is.

https://github.com/llvm/llvm-project/pull/99576