[llvm] [InstCombine] Resolve TODO: Remove one-time check if other logic operand (Y) is constant (PR #77973)

[Jessica Clarke via llvm-commits]

https://github.com/jrtc27 requested changes to this pull request.

You have a commit to precommit tests, but the second commit doesn't touch any of the tests?

Also the precommit commit will need to be its own PR otherwise it'll get squashed when merging.

https://github.com/llvm/llvm-project/pull/77973