[llvm] [VPlan] Use VPInstruction for VPScalarPHIRecipe. (NFCI) (PR #129767)

[via llvm-commits]

================
@@ -71,6 +71,10 @@ Type *VPTypeAnalysis::inferScalarTypeForRecipe(const VPInstruction *R) {
   }
   case VPInstruction::ExplicitVectorLength:
     return Type::getIntNTy(Ctx, 32);
+  case Instruction::PHI:
+    // Avoid inferring the type for other operands, as this may lead to infinite
+    // recursions for cycles.
----------------
ayalz wrote:

```suggestion
    // Infer the type of first operand only, as other operands of header phi's may
    //  lead to infinite recursion.
```

https://github.com/llvm/llvm-project/pull/129767