[llvm] [VPlan] Simplify VPBlendRecipes to select instructions (PR #133993)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

I saw your follow-up patch, and I think this LGTM, although I feel like I'm missing context.

https://github.com/llvm/llvm-project/pull/133993