[turbofan] Add support for transitioning stores to double fields.

src/compiler/access-builder.h

 // Copyright 2014 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_ACCESS_BUILDER_H_
 #define V8_COMPILER_ACCESS_BUILDER_H_
 
 #include "src/compiler/simplified-operator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // This access builder provides a set of static methods constructing commonly
 // used FieldAccess and ElementAccess descriptors. These descriptors serve as
 // parameters to simplified load/store operators.
 class AccessBuilder final : public AllStatic {
  public:
   // ===========================================================================
   // Access to heap object fields and elements (based on tagged pointer).
 
   // Provides access to HeapObject::map() field.
   static FieldAccess ForMap();
 
+  // Provides access to HeapNumber::value() field.
+  static FieldAccess ForHeapNumberValue();
+
   // Provides access to JSObject::properties() field.
   static FieldAccess ForJSObjectProperties();
 
   // Provides access to JSObject::elements() field.
   static FieldAccess ForJSObjectElements();
 
   // Provides access to JSFunction::context() field.
   static FieldAccess ForJSFunctionContext();
 
   // Provides access to JSFunction::shared() field.
@@ skipping 79 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ACCESS_BUILDER_H_