[llvm] [VPlan] Insert VPBlendRecipes in post order. NFC (PR #201782)

[Luke Lau via llvm-commits]

lukel97 wrote:

> I guess this is fine for now, so I definitely wouldn't want to block it, but I have a feeling RPOT would be better if we ever try to preserve some "uniform" branches as that would require placing SSA-phis sometimes.

Do you mean as in for partial control flow linearisation? I don't think we need to insert new phis, only adjust existing ones by replacing the incoming values with blends where control flow was linearized. Is there any reason why post order wouldn't work for that?

https://github.com/llvm/llvm-project/pull/201782