[llvm] [LV][VPlan] Add initial support for CSA vectorization (PR #106560)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

I added some comments inline.

On the high level, it would be good to have a test that checks the printed VPlan, to see things on a higher level.

Supporting both EVL and non-EVL in a single patch makes the patch quite big and I think it would help to separate them and first start with the simpler case

https://github.com/llvm/llvm-project/pull/106560