For-of calls [Symbol.iterator]() on RHS to get iterator

src/generator.js

 // Copyright 2013 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.
 
 "use strict";
 
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Function = global.Function;
 
@@ skipping 42 matching lines @@
 }
 
 
 function SetUpGenerators() {
   %CheckIsBootstrapping();
   var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
   InstallFunctions(GeneratorObjectPrototype,
                    DONT_ENUM | DONT_DELETE | READ_ONLY,
                    ["next", GeneratorObjectNext,
                     "throw", GeneratorObjectThrow]);
+  %FunctionSetName(GeneratorObjectIterator, '[Symbol.iterator]');
   %SetProperty(GeneratorObjectPrototype, symbolIterator, GeneratorObjectIterator,
       DONT_ENUM | DONT_DELETE | READ_ONLY);
   %SetProperty(GeneratorObjectPrototype, "constructor",
                GeneratorFunctionPrototype, DONT_ENUM | DONT_DELETE | READ_ONLY);
   %SetPrototype(GeneratorFunctionPrototype, $Function.prototype);
   %SetCode(GeneratorFunctionPrototype, GeneratorFunctionPrototypeConstructor);
   %SetProperty(GeneratorFunctionPrototype, "constructor",
                GeneratorFunction, DONT_ENUM | DONT_DELETE | READ_ONLY);
   %SetPrototype(GeneratorFunction, $Function);
   %SetCode(GeneratorFunction, GeneratorFunctionConstructor);
 }
 
 SetUpGenerators();