[llvm] [InstCombine] Simplify and/or of icmp eq with op replacement (PR #70335)

[via llvm-commits]

mikaelholmen wrote:

> I've tried the following variant that only checks for true/false results ([d8ea7f2](https://github.com/llvm/llvm-project/commit/d8ea7f205a09e9c9adcd8556c21a1494cc05b170)). Unfortunately, this still causes stage2 llvm-tblgen crashes, so this wasn't the only issue :(

I applied https://github.com/nikic/llvm-project/commit/d8ea7f205a09e9c9adcd8556c21a1494cc05b170 locally and reran the original testcase I had that failed, and now it passes so unfortunately that isn't of any use anymore. :(

https://github.com/llvm/llvm-project/pull/70335