[llvm] [PGO] Drive profile validator from opt (PR #147418)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

I'm assuming you've already looked at trying to just make `lit` add the flag to opt invocations rather than going through an additional CMake flag?

https://github.com/llvm/llvm-project/pull/147418