[llvm-branch-commits] [llvm][misexpect] Update MisExpect to use provenance tracking metadata (PR #86610)

[Paul Kirth via llvm-branch-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/86610

With the IR extension added to MD_prof branch weights, we can now easily
destinguish between weights added by `llvm.expect*` intrinsics and
weights from other sources. This patch re-enables the assert checking
for malformed metadata, which should never happen using the
`llvm.expect*` family of intrinsics.