[llvm] [BOLT] Expose pseudo probe function checksum (PR #99389)

[via llvm-commits]

WenleiHe wrote:

In theory we just need a function checksum, plus a set of stable block Ids for each function. I think we don't have to prefix everything with "pseudo-probe" -- probe is one way, and the current way of getting checksum and stable block id for llvm compiled binary when csspgo is used, but at bolt level, it doesn't have to be tied to probe and it can be anything that the compiler and binary provides. 

https://github.com/llvm/llvm-project/pull/99389