[llvm] [SLP][TTI]Add support for strided loads. (PR #80310)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> Can I ask you to separate the TTI pieces to a separate review? I'd be comfortable LGTMing that with some pretty minimal changes, but can't reasonable review the SLP changes in any depth.

I can't, since don't know how to test TTI changes without SLP vectorizer support.

https://github.com/llvm/llvm-project/pull/80310