[es6] Partially implement Reflect.preventExtensions.

src/bootstrapper.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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/code-stubs.h"
@@ skipping 1907 matching lines @@
   JSObject::AddProperty(global, reflect_string, reflect, DONT_ENUM);
 
   SimpleInstallFunction(reflect, "deleteProperty",
                         Builtins::kReflectDeleteProperty, 2, true);
   SimpleInstallFunction(reflect, "get",
                         Builtins::kReflectGet, 3, false);
   SimpleInstallFunction(reflect, "has",
                         Builtins::kReflectHas, 2, true);
   SimpleInstallFunction(reflect, "isExtensible",
                         Builtins::kReflectIsExtensible, 1, true);
+  SimpleInstallFunction(reflect, "preventExtensions",
+                        Builtins::kReflectPreventExtensions, 1, true);
 }
 
 
 void Genesis::InitializeGlobal_harmony_sharedarraybuffer() {
   if (!FLAG_harmony_sharedarraybuffer) return;
 
   Handle<JSGlobalObject> global(
       JSGlobalObject::cast(native_context()->global_object()));
 
   Handle<JSFunction> shared_array_buffer_fun = InstallFunction(
@@ skipping 1366 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8