[llvm] [ValueTracking] Extend LHS/RHS with matching operand to work without constants. (PR #85557)

[via llvm-commits]

goldsteinn wrote:

> > This patch seems to block SROA: [dtcxzyw/llvm-opt-benchmark#419 (comment)](https://github.com/dtcxzyw/llvm-opt-benchmark/pull/419#discussion_r1527863982).
> 
> This problem is still outstanding. Any thoughts about preserving information from the `exact` flag?

I think this is a more general problem that we don't have any good solution for. Think the diff is net positive so would prefer to not block this patch w/ the potentially intractable problem of folds throwing away information



https://github.com/llvm/llvm-project/pull/85557