[llvm] [VPlan] Use VPlan predecessors in VPWidenPHIRecipe (NFC). (PR #126388)

[via llvm-commits]

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@@ -1958,13 +1958,12 @@ class VPScalarPHIRecipe : public VPHeaderPHIRecipe {
 #endif
 };
 
-/// A recipe for handling phis that are widened in the vector loop.
-/// In the VPlan native path, all incoming VPValues & VPBasicBlock pairs are
-/// managed in the recipe directly.
+/// A recipe for widened phis. Incoming values are operands of the recipe and
+/// their operand index corresponds to the incoming predeocessor block. If the
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ayalz wrote:

```suggestion
/// their operand index corresponds to the incoming predecessor block. If the
```

https://github.com/llvm/llvm-project/pull/126388