[stubs] Unify (and optimize) implementation of ToObject.

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 1443 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(Name, name, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, setter, 2);
   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();
 }
+
+
+RUNTIME_FUNCTION(Runtime_ToObject) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+  Handle<JSReceiver> receiver;
+  if (JSReceiver::ToObject(isolate, object).ToHandle(&receiver)) {
+    return *receiver;
+  }
+  THROW_NEW_ERROR_RETURN_FAILURE(
+      isolate, NewTypeError(MessageTemplate::kUndefinedOrNullToObject));
+}
+
 }  // namespace internal
 }  // namespace v8