[llvm] BasicAA: return more PartialAlias when scalable (PR #110519)

[Nikita Popov via llvm-commits]

nikic wrote:

> Gentle ping. Can we verify that this is useful?

The only thing that uses PartialAlias is GVN, where it is used to do store-to-load forwarding from a large store to a smaller load at an offset (see also VNCoercion). So I'd try to come up with some test cases like that and see if it helps anywhere. It's pretty likely that the relevant code doesn't support scalable types though.

https://github.com/llvm/llvm-project/pull/110519