[turbofan] CheckedTaggedToInt32 doesn't distinguish undefined and hole.

src/compiler/simplified-operator-reducer.cc

Index: src/compiler/simplified-operator-reducer.cc
diff --git a/src/compiler/simplified-operator-reducer.cc b/src/compiler/simplified-operator-reducer.cc
index d172adcf604e34ca3d05f0b8b8394835a9b37d42..5ae52c4854d08e4839668d8c15a21ab5be170f3b 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -126,6 +126,7 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
+    case IrOpcode::kCheckedTaggedToInt32:
     case IrOpcode::kCheckedTaggedSignedToInt32: {
       NodeMatcher m(node->InputAt(0));
       if (m.IsConvertTaggedHoleToUndefined()) {