[llvm] [VPlan] Dispatch to multiple exit blocks via middle blocks. (PR #112138)

[Florian Hahn via llvm-commits]

fhahn wrote:

> was doing. It's pretty difficult to parse all of the comment history in github - is the reason for the change because you want to avoid calling `hasUncountableEarlyExit` and are doing this as a shortcut? That seems fine.

Yep exactly, it is in some places more convenient to have a single call that returns `nullptr` if there's no vectorizable early exit block


https://github.com/llvm/llvm-project/pull/112138