[builtins] Also port the Object.prototype.__proto__ accessors to C++.

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 232 matching lines @@
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, obj, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
   MAYBE_RETURN(
       JSReceiver::SetPrototype(obj, prototype, false, Object::THROW_ON_ERROR),
       isolate->heap()->exception());
   return *obj;
 }
 
-
-RUNTIME_FUNCTION(Runtime_SetPrototype) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, obj, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
-  MAYBE_RETURN(
-      JSReceiver::SetPrototype(obj, prototype, true, Object::THROW_ON_ERROR),
-      isolate->heap()->exception());
-  return *obj;
-}
-
 RUNTIME_FUNCTION(Runtime_OptimizeObjectForAddingMultipleProperties) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
   CONVERT_SMI_ARG_CHECKED(properties, 1);
   // Conservative upper limit to prevent fuzz tests from going OOM.
   if (properties > 100000) return isolate->ThrowIllegalOperation();
   if (object->HasFastProperties() && !object->IsJSGlobalProxy()) {
     JSObject::NormalizeProperties(object, KEEP_INOBJECT_PROPERTIES, properties,
                                   "OptimizeForAdding");
@@ skipping 619 matching lines @@
   if (!success) return isolate->heap()->exception();
   MAYBE_RETURN(
       JSReceiver::CreateDataProperty(&it, value, Object::THROW_ON_ERROR),
       isolate->heap()->exception());
   return *value;
 }
 
 
 }  // namespace internal
 }  // namespace v8