[llvm] [VPlan] Expand AddRecs in VPSCEVExpander (PR #209921)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> > Could you add an IR test case for this so we can confirm this is fixed by #215253?
> 
> Very sorry about not adding the test -- I was busy with SCEV work. However, the test would be no different in principle from what you've already included in the PR: llvm-opt-benchmark shows this. By the way, we can use llvm-opt-benchmark for vectorization, as it runs the vectorizer now!

Looks like it wasn't fixed -- will try to add that test now.

https://github.com/llvm/llvm-project/pull/209921