[llvm] [BOLT] Add sink block to flow CFG in profile inference (PR #95047)

[Amir Ayupov via llvm-commits]

https://github.com/aaupov approved this pull request.

This state looks good to me. @WenleiHe - do you have any unresolved questions or concerns? We'd like to keep the FlowGraph construction logic in BOLT for now.

https://github.com/llvm/llvm-project/pull/95047