[llvm] [LV, VPlan] Check if plan is compatible to EVL transform (PR #92092)

[Pengcheng Wang via llvm-commits]

wangpc-pp wrote:

> > I found some loops can't be vectorized and finally I dug to this PR. :-) I simply commented out these lines in this PR and the loop can be vectorized correctly. What's the status now? Are there any things I missed?
> 
> Do you find any other cases with functional/performance issue if it bails out to DataWithoutLaneMask style mask instead of discarding the VPlan? Is it better to bail out to TailFoldingStyle::Data style as what getPreferredTailFoldingStyle prefers when V extension enables. If it bails out to TailFoldingStyle::Data style, then useActiveLaneMask should do some work at tryToBuildVPlanWithVPRecipes.

The problem I met is because there are some `VPWidenPointerInductionRecipe`s and it can't be handled when using EVL tail folding. I don't see any problem when using `Data` or `DataWithoutLaneMask`.

https://github.com/llvm/llvm-project/pull/92092