[llvm] [Reassociate] Use UniformityInfo to group uniform operands together (PR #198507)

[Jay Foad via llvm-commits]

jayfoad wrote:

I don't understand why you need TTI at all. Isn't UA supposed to be virtually free on targets without divergence? Especially now that the new pass manager also lets you avoid computing CycleInfo?

https://github.com/llvm/llvm-project/pull/198507