[llvm] [VPlan] Create header phis once, after constructing VPlan0 (NFC). (PR #168291)

[Florian Hahn via llvm-commits]

================
@@ -8206,56 +8160,12 @@ bool VPRecipeBuilder::getScaledReductions(
 
 VPRecipeBase *VPRecipeBuilder::tryToCreateWidenRecipe(VPSingleDefRecipe *R,
----------------
fhahn wrote:

Updated, thanks!

https://github.com/llvm/llvm-project/pull/168291