[llvm] [VPlan] Make canonical IV part of the region (PR #156262)

[via llvm-commits]

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@@ -509,8 +528,6 @@ static void createExtractsForLiveOuts(VPlan &Plan, VPBasicBlock *MiddleVPBB) {
   }
 }
 
-/// Return an iterator range to iterate over pairs of matching phi nodes in
-/// \p Header and \p ScalarHeader, skipping the canonical IV in the former.
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ayalz wrote:

Good to retain the documentation as well.

https://github.com/llvm/llvm-project/pull/156262