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

src/compiler/js-intrinsic-lowering.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_JS_INTRINSIC_LOWERING_H_
 #define V8_COMPILER_JS_INTRINSIC_LOWERING_H_
 
 #include "src/compiler/graph-reducer.h"
 #include "src/compiler/simplified-operator.h"
 
@@ skipping 13 matching lines @@
   explicit JSIntrinsicLowering(JSGraph* jsgraph);
   ~JSIntrinsicLowering() FINAL {}
 
   Reduction Reduce(Node* node) FINAL;
 
  private:
   Reduction ReduceDeoptimizeNow(Node* node);
   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);
   Reduction Change(Node* node, const Operator* op, Node* a, Node* b, Node* c);
 
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }
   CommonOperatorBuilder* common() const;
   MachineOperatorBuilder* machine() const;
   SimplifiedOperatorBuilder* simplified() { return &simplified_; }
 
   JSGraph* jsgraph_;
   SimplifiedOperatorBuilder simplified_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_INTRINSIC_LOWERING_H_