[llvm] [InstCombine] Resolve FIXME: Use commutative matchers (PR #81060)

[Nikita Popov via llvm-commits]

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

Each change should be submitted separately, with appropriate test coverage. ***Do not submit changes for which you cannot demonstrate test changes.*** While some of it may be right, most of your changes in here are nonsensical.

https://github.com/llvm/llvm-project/pull/81060