[llvm] [InstCombine] Fold select of and/or subset identity (PR #207925)

[Yingwei Zheng via llvm-commits]

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

A correctness issue was identified by [llvm-hackme](https://github.com/dtcxzyw/llvm-hackme). Please see the [issue comment](https://github.com/llvm/llvm-project/pull/207925#issuecomment-4902023250) for details.

https://github.com/llvm/llvm-project/pull/207925