[llvm] [VPlan] Extract reverse interleave pointer adjustment into VPReverseInterleavePtrRecipe (PR #144864)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

As mentioned in this patch, supporting interleaved access with EVL tail folding could be complex. The simplest approach might be to directly create a VPInterleaveEVLRecipe and extract as much shared code as possible into static functions. I'd like to open a discussion to clarify which direction would be preferable.

https://github.com/llvm/llvm-project/pull/144864