[llvm] [SamplePGO] Handle FS discriminators in SampleProfileMatcher (PR #90858)

[Krzysztof Pszeniczny via llvm-commits]

amharc wrote:

Tagging @wlei-llvm @xur-llvm @WenleiHe (I don't have commit access, so I can't directly assign reviewers).

https://github.com/llvm/llvm-project/pull/90858