[llvm] [EarlyCSE,TTI] Clean up temporary insts created by getOrCreateResult. (PR #134534)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

> As far as I can tell, getMatchingValue/getOrCreateResult can get used either unconditionally, or for comparison against an existing value. The comparison against an existing value is of course always going to fail if new instructions are created. So I think the right way to do this would be to pass an extra flag whether creating instructions is allowed or not.

Yep, updated the patch.

https://github.com/llvm/llvm-project/pull/134534