[llvm] [SCEV] Add missing Map.lookup in SCEVLoopGuardRewriter visitAddExpr/v… (PR #197433)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

There's something similar here https://github.com/llvm/llvm-project/pull/159942. There were some compile-time increases which is why I've not merged it yet, as I am currently still trying to see how we can reduce the impact. IIRC the main impact was actually from the early lookup

https://github.com/llvm/llvm-project/pull/197433