[turbofan] Support for %_DoubleHi, %_DoubleLo and %_ConstructDouble.

src/compiler/machine-operator-reducer.h

Index: src/compiler/machine-operator-reducer.h
diff --git a/src/compiler/machine-operator-reducer.h b/src/compiler/machine-operator-reducer.h
index f7c3bd7cfde5b04f0eb81e8e80511f84ca101992..4fc11ce89899aafce7be75b6209905aad55751a4 100644
--- a/src/compiler/machine-operator-reducer.h
+++ b/src/compiler/machine-operator-reducer.h
@@ -78,6 +78,7 @@ class MachineOperatorReducer FINAL : public Reducer {
   Reduction ReduceWord32Sar(Node* node);
   Reduction ReduceWord32And(Node* node);
   Reduction ReduceWord32Or(Node* node);
+  Reduction ReduceFloat64InsertWord32(Node* node);
 
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }