[llvm] [InstCombine] Improve coverage of `foldSelectValueEquivalence` (PR #88298)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> If not any suggestions for simplifying to make it reviewable?

I guess I can provide some suggestions after the ir diff is available :)


https://github.com/llvm/llvm-project/pull/88298