[llvm] [VPlan] Convert EVL loops to variable-length stepping after dissolution (PR #147222)

[Luke Lau via llvm-commits]

lukel97 wrote:

It looks like `LLVM.Transforms/LoopVectorize/RISCV/vectorize-force-tail-with-evl-interleave.ll` is failing on CI, it might need updated?

https://github.com/llvm/llvm-project/pull/147222