[llvm] [InstCombine] Fold negation of unsigned div of non-negatives (PR #84951)

[Antonio Frighetto via llvm-commits]

antoniofrighetto wrote:

> We only want to perform this fold is RHS is constant.

Why is that the case and we don't want to extend it to values? The folding won't be applied on the current tests, which do not have any constants.

https://github.com/llvm/llvm-project/pull/84951