[llvm-branch-commits] [llvm][ProfDataUtils] provide getNumBranchWeights API (PR #90146)

[Paul Kirth via llvm-branch-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/90146

As suggested in https://github.com/llvm/llvm-project/pull/86609/files#r1556689262
an API for getting the number of branch weights directly from the MD node would
be useful in a variety of checks, and keeps the logic within ProfDataUtils.