[turbofan] Eliminate redundant ChangeTaggedSignedToInt32.

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 5ae52c4854d08e4839668d8c15a21ab5be170f3b..2da6b847c4b016f8c031ae43487c4975684f12bb 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -89,6 +89,7 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
+    case IrOpcode::kChangeTaggedSignedToInt32:
     case IrOpcode::kChangeTaggedToInt32: {
       NumberMatcher m(node->InputAt(0));
       if (m.HasValue()) return ReplaceInt32(DoubleToInt32(m.Value()));