[llvm] [SelectOpt] Add handling for Select-like operations. (PR #77284)

[Sjoerd Meijer via llvm-commits]

sjoerdmeijer wrote:

I might be wrong, but I suspect we could do with some test-cases, especially negative tests when this shouldn't trigger. From a quick look, things like when the pattern doesn't exactly matches, one use, dbg instructions, if it is not a terminator, etc.

https://github.com/llvm/llvm-project/pull/77284