[strong] Introduce strong bit

src/runtime/runtime-object.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug.h"
 #include "src/messages.h"
@@ skipping 1500 matching lines @@
 
 
 RUNTIME_FUNCTION(Runtime_IsSpecObject) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   return isolate->heap()->ToBoolean(obj->IsSpecObject());
 }
 
 
+RUNTIME_FUNCTION(Runtime_IsStrong) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj->IsJSReceiver() &&
+                                    JSReceiver::cast(obj)->map()->is_strong());
+}
+
+
 RUNTIME_FUNCTION(Runtime_ClassOf) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   if (!obj->IsJSReceiver()) return isolate->heap()->null_value();
   return JSReceiver::cast(obj)->class_name();
 }
 
 
 RUNTIME_FUNCTION(Runtime_DefineGetterPropertyUnchecked) {
@@ skipping 21 matching lines @@
   CONVERT_PROPERTY_ATTRIBUTES_CHECKED(attrs, 3);
 
   RETURN_FAILURE_ON_EXCEPTION(
       isolate,
       JSObject::DefineAccessor(object, name, isolate->factory()->null_value(),
                                setter, attrs));
   return isolate->heap()->undefined_value();
 }
 }
 }  // namespace v8::internal