[llvm] [LICM] Invalidate cached SCEV results after reassociation (PR #92655)

[Antonio Frighetto via llvm-commits]

antoniofrighetto wrote:

I thought about that, although 1) I feel like it overall feels more natural to modify in-place considering how the whole code here is structured around uses 2) If we do this for hoistMulAddAssociation, I think we should rewrite the other reassociate and hoist folds here not to be in-place as well? 3) It looks like we favour rewriting in-place when it comes to letting SCEV forget user in most of loop transform, but no strong opinions.

https://github.com/llvm/llvm-project/pull/92655