Remove the global Strength enum class completely.

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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 818 matching lines @@
 
 
 RUNTIME_FUNCTION(Runtime_IsJSReceiver) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   return isolate->heap()->ToBoolean(obj->IsJSReceiver());
 }
 
 
-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 273 matching lines @@
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(Object, o, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, properties, 1);
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, o, JSReceiver::DefineProperties(isolate, o, properties));
   return *o;
 }
 
 }  // namespace internal
 }  // namespace v8