[es6] Tail calls support.

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/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 2300 matching lines @@
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_destructuring_assignment)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_object_observe)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexps)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_unicode_regexps)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_completion)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tolength)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_do_expressions)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_regexp_lookbehind)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_function_name)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(promise_extra)
-
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_tailcalls)
 
 void InstallPublicSymbol(Factory* factory, Handle<Context> native_context,
                          const char* name, Handle<Symbol> value) {
   Handle<JSGlobalObject> global(
       JSGlobalObject::cast(native_context->global_object()));
   Handle<String> symbol_string = factory->InternalizeUtf8String("Symbol");
   Handle<JSObject> symbol = Handle<JSObject>::cast(
       JSObject::GetProperty(global, symbol_string).ToHandleChecked());
   Handle<String> name_string = factory->InternalizeUtf8String(name);
   PropertyAttributes attributes =
@@ skipping 595 matching lines @@
   static const char* harmony_proxies_natives[] = {"native proxy.js", nullptr};
   static const char* harmony_modules_natives[] = {nullptr};
   static const char* harmony_regexps_natives[] = {"native harmony-regexp.js",
                                                   nullptr};
   static const char* harmony_tostring_natives[] = {nullptr};
   static const char* harmony_sloppy_natives[] = {nullptr};
   static const char* harmony_sloppy_function_natives[] = {nullptr};
   static const char* harmony_sloppy_let_natives[] = {nullptr};
   static const char* harmony_species_natives[] = {"native harmony-species.js",
                                                   nullptr};
+  static const char* harmony_tailcalls_natives[] = {nullptr};
   static const char* harmony_unicode_regexps_natives[] = {
       "native harmony-unicode-regexps.js", nullptr};
   static const char* harmony_default_parameters_natives[] = {nullptr};
   static const char* harmony_reflect_natives[] = {"native harmony-reflect.js",
                                                   nullptr};
   static const char* harmony_destructuring_bind_natives[] = {nullptr};
   static const char* harmony_destructuring_assignment_natives[] = {nullptr};
   static const char* harmony_object_observe_natives[] = {
       "native harmony-object-observe.js", nullptr};
   static const char* harmony_sharedarraybuffer_natives[] = {
@@ skipping 678 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8