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

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

Is the plan for this to replace #131005? From what I remember in that PR we wanted to keep the canonical IV around for the other vectorization passes since it's more amenable for analysis. Maybe things have changed in the meantime. cc @mshockwave 

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