[turbofan] Avoid unnecessary tagging of floating point values.

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 012004a8af6c1c895fd680c589501cd19c300bb1..c3bac877e10c7846c9d37e0c838ca620ce3aab8b 100644
--- a/src/compiler/simplified-operator-reducer.cc
+++ b/src/compiler/simplified-operator-reducer.cc
@@ -47,6 +47,7 @@ Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
     case IrOpcode::kChangeFloat64ToTagged: {
       Float64Matcher m(node->InputAt(0));
       if (m.HasValue()) return ReplaceNumber(m.Value());
+      if (m.IsChangeTaggedToFloat64()) return Replace(m.node()->InputAt(0));
       break;
     }
     case IrOpcode::kChangeInt32ToTagged: {