[llvm] [VP][EVL] Support select instruction with EVL-vectorization (PR #109614)

[via llvm-commits]

LiqinWeng wrote:


> In conclusion, we only need to transforms the partial recipes into EVL recipes. As for which ones exactly, we can determine by whether the recipe has a mask operand to decide if an EVL recipe is necessary.

If triple count is not a constant, can it be directly introduced into EVL?



https://github.com/llvm/llvm-project/pull/109614