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

[Pankaj Dwivedi via llvm-commits]

PankajDwivedi-25 wrote:

> Last call for pre-merge complaints (I can't tell if that "should TTI be here" is blocking or more of a "hmmmm...".
> 
> @PankajDwivedi-25 I figure we could either land this before LLVM 23 (so US tomorrow) or right after it (US Wednesday) - I'll leave that up to you.

as suggested I will wait for today for any further feedback.

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