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

src/compiler/js-intrinsic-lowering.h

Index: src/compiler/js-intrinsic-lowering.h
diff --git a/src/compiler/js-intrinsic-lowering.h b/src/compiler/js-intrinsic-lowering.h
index d19c0f612123b297f937f27d089f58c0420b600e..d728c273f63257784c387d46f977bc943b5d90b7 100644
--- a/src/compiler/js-intrinsic-lowering.h
+++ b/src/compiler/js-intrinsic-lowering.h
@@ -31,6 +31,9 @@ class JSIntrinsicLowering FINAL : public Reducer {
   Reduction ReduceInlineIsSmi(Node* node);
   Reduction ReduceInlineIsNonNegativeSmi(Node* node);
   Reduction ReduceInlineIsInstanceType(Node* node, InstanceType instance_type);
+  Reduction ReduceInlineOptimizedConstructDouble(Node* node);
+  Reduction ReduceInlineOptimizedDoubleLo(Node* node);
+  Reduction ReduceInlineOptimizedDoubleHi(Node* node);
   Reduction ReduceInlineValueOf(Node* node);
 
   Reduction Change(Node* node, const Operator* op);