[llvm] [VPlan] Introduce scalar loop header in plan, remove VPLiveOut. (PR #109975)

[Florian Hahn via llvm-commits]

fhahn wrote:

>  Or if not, is it possible to tag me as a reviewer or subscriber for other patches in this area? Thanks!

Probably the best way would be to join the subscriber team for the vectorizer label: https://github.com/orgs/llvm/teams/pr-subscribers-vectorizers

https://github.com/llvm/llvm-project/pull/109975