[clang] Revert "[Clang][CMake] Use IRPGO instead of FE PGO for Cmake Caches (#155957)" (PR #159367)

[Paschalis Mpeis via cfe-commits]

paschalis-mpeis wrote:

Hey @boomanaiden154,

Thanks for the quick reply! You are right, I've updated the PR description.

> I'll try and reproduce this locally on a AArch64 machine. If I can't, I'm going to need you to reproduce and send over a profile and maybe some bitcode. I'll reach out if I end up needing anything.

I was able to run without issues with this reversal patch on top of `a044d6118208`.
Of course, happy to follow-up if needed.

Given your approval, should I proceed with the merge?

https://github.com/llvm/llvm-project/pull/159367