Rewrite Object.prototype.toString in C++

src/objects.h

 // Copyright 2012 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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 2453 matching lines @@
   // Gets the number of currently used elements.
   int GetFastElementsUsage();
 
   // Deletes an existing named property in a normalized object.
   static void DeleteNormalizedProperty(Handle<JSObject> object,
                                        Handle<Name> name, int entry);
 
   static bool AllCanRead(LookupIterator* it);
   static bool AllCanWrite(LookupIterator* it);
 
+  // ES6 19.1.3.6 Object.prototype.toString
+  MUST_USE_RESULT static MaybeHandle<String> ObjectProtoToString(
+      Isolate* isolate, Handle<Object> object);
+
  private:
   friend class JSReceiver;
   friend class Object;
 
   static void MigrateFastToFast(Handle<JSObject> object, Handle<Map> new_map);
   static void MigrateFastToSlow(Handle<JSObject> object,
                                 Handle<Map> new_map,
                                 int expected_additional_properties);
 
   // Used from Object::GetProperty().
@@ skipping 8211 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_