[llvm] [licm] don't drop `MD_prof` when dropping other metadata (PR #152420)

[Mircea Trofin via llvm-commits]

mtrofin wrote:

### Merge activity

* **Aug 16, 2:24 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/152420).


https://github.com/llvm/llvm-project/pull/152420