[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

I'm happy enough with it as is, I'd like @Sirraide to do 1 last pass, but if he approves, so do I.

https://github.com/llvm/llvm-project/pull/99656