[llvm] [VPlan] Add exit phi operands during initial construction (NFC). (PR #136455)

[via llvm-commits]

================
@@ -2501,35 +2501,41 @@ void VPlanTransforms::handleUncountableEarlyExit(
     if (!ExitIRI)
       break;
 
-    PHINode &ExitPhi = ExitIRI->getIRPhi();
-    VPValue *IncomingFromEarlyExit = RecipeBuilder.getVPValueOrAddLiveIn(
-        ExitPhi.getIncomingValueForBlock(UncountableExitingBlock));
-
+    unsigned EarlyExitIdx = 0;
     if (OrigLoop->getUniqueExitBlock()) {
+      // After the transform, the first incoming value is coming from the
+      // orignial loop latch, while the second operand is from the early exit.
----------------
ayalz wrote:

```suggestion
      // original loop latch, while the second operand to the early exit.
```

https://github.com/llvm/llvm-project/pull/136455