[llvm] [BOLT] Use deterministic xxh3 for computing BF/BB hashes (PR #72542)

[via llvm-commits]

spupyrev wrote:

The changes is a "completed" version of https://github.com/llvm/llvm-project/pull/65437 with tests -- I didn't know how to commandeer the change so had to create a new PR

https://github.com/llvm/llvm-project/pull/72542