[llvm] [NFC] Clang format PeepholeOptimizer (PR #116325)

[Akshat Oke via llvm-commits]

optimisan wrote:

### Merge activity

* **Nov 18, 12:24 AM EST**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/116325).


https://github.com/llvm/llvm-project/pull/116325