[llvm] [VPlan] Add VPRegionBlock::getCanonicalIVType (NFC). (PR #164127)

[via llvm-commits]

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@@ -69,8 +69,7 @@ class UnrollState {
                                 VPBasicBlock::iterator InsertPtForPhi);
 
   VPValue *getConstantVPV(unsigned Part) {
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ayalz wrote:

Independent:
```suggestion
  VPValue *getConstantIntVPV(unsigned Part) {
```

https://github.com/llvm/llvm-project/pull/164127