[llvm] [VPlan] Skip uses-scalars restriction if one of ops needs broadcast. (PR #168246)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

Can we land this after https://github.com/llvm/llvm-project/pull/167880 reaches a conclusion? I think there's a valuable pre-commit test there, that might no longer be useful after this patch?

https://github.com/llvm/llvm-project/pull/168246