[clang] [llvm] [PGOVerify] Add end-to-end IPGOVerifier infrastructure, validations, and function filtering (PR #196295)

[Shubham Sandeep Rastogi via cfe-commits]

https://github.com/rastogishubham commented:

I can't speak for the PGOVerify code itself, because PGO isn't my strong suit, but the code in StandardInstrumentations.h looks good to me

https://github.com/llvm/llvm-project/pull/196295