[es6] Fix Function and GeneratorFunction built-ins subclassing.

test/mjsunit/es6/classes-subclass-builtins.js

Index: test/mjsunit/es6/classes-subclass-builtins.js
diff --git a/test/mjsunit/es6/classes-subclass-builtins.js b/test/mjsunit/es6/classes-subclass-builtins.js
index c65818eccaf1e297a25b6ea7fdc60c3011127967..4d640a918c442e6569c9c90b23d2682a341758ea 100644
--- a/test/mjsunit/es6/classes-subclass-builtins.js
+++ b/test/mjsunit/es6/classes-subclass-builtins.js
@@ -18,6 +18,30 @@ function checkPrototypeChain(object, constructors) {
 
 
 (function() {
+  class A extends Function {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A("this.foo = 153;");
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Function);
+  assertTrue(o instanceof A);
+  assertEquals("function", typeof o);
+  checkPrototypeChain(o, [A, Function, Object]);
+  assertEquals(42, o.a);
+  var oo = new o();
+  assertEquals(153, oo.foo);
+
+  var o1 = new A("return 312;");
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
   class A extends Boolean {
     constructor(...args) {
       assertTrue(%IsConstructCall());
@@ -294,6 +318,42 @@ function TestArraySubclassing(array) {
 
 
 (function() {
+  // TODO(ishell): remove once GeneratorFunction is available.
+  var GeneratorFunction = (function*() {}).__proto__.constructor;
+  class A extends GeneratorFunction {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+  var generator_func = new A("var index = 0; while (index < 5) { yield ++index; }");
+  assertTrue(generator_func instanceof Object);
+  assertTrue(generator_func instanceof Function);
+  assertTrue(generator_func instanceof GeneratorFunction);
+  assertTrue(generator_func instanceof A);
+  assertEquals("function", typeof generator_func);
+  checkPrototypeChain(generator_func, [A, GeneratorFunction, Function, Object]);
+  assertEquals(42, generator_func.a);
+
+  var o = new generator_func();
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof generator_func);
+  assertEquals("object", typeof o);
+
+  assertPropertiesEqual({done: false, value: 1}, o.next());
+  assertPropertiesEqual({done: false, value: 2}, o.next());
+  assertPropertiesEqual({done: false, value: 3}, o.next());
+  assertPropertiesEqual({done: false, value: 4}, o.next());
+  assertPropertiesEqual({done: false, value: 5}, o.next());
+  assertPropertiesEqual({done: true, value: undefined}, o.next());
+
+  var generator_func1 = new A("return 0;");
+  assertTrue(%HaveSameMap(generator_func, generator_func1));
+})();
+
+
+(function() {
   class A extends Boolean {
     constructor() {
       assertTrue(%IsConstructCall());