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

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 1098 matching lines @@
   JSObject::AddProperty(
       global_object, object_name, isolate->object_function(), DONT_ENUM);
 
   Handle<JSObject> global(native_context()->global_object());
 
   // Install global Function object
   Handle<JSFunction> function_function =
       InstallFunction(global, "Function", JS_FUNCTION_TYPE, JSFunction::kSize,
                       empty_function, Builtins::kIllegal);
   function_function->initial_map()->set_is_callable();
+  function_function->initial_map()->set_is_constructor(true);
 
   {  // --- A r r a y ---
     Handle<JSFunction> array_function =
         InstallFunction(global, "Array", JS_ARRAY_TYPE, JSArray::kSize,
                         isolate->initial_object_prototype(),
                         Builtins::kArrayCode);
     array_function->shared()->DontAdaptArguments();
     array_function->shared()->set_function_data(Smi::FromInt(kArrayCode));
 
     // This seems a bit hackish, but we need to make sure Array.length
@@ skipping 815 matching lines @@
     JSObject::AddProperty(
         container, factory->InternalizeUtf8String("GeneratorFunctionPrototype"),
         generator_function_prototype, NONE);
 
     static const bool kUseStrictFunctionMap = true;
     Handle<JSFunction> generator_function_function =
         InstallFunction(container, "GeneratorFunction", JS_FUNCTION_TYPE,
                         JSFunction::kSize, generator_function_prototype,
                         Builtins::kIllegal, kUseStrictFunctionMap);
     generator_function_function->initial_map()->set_is_callable();
+    generator_function_function->initial_map()->set_is_constructor(true);
   }
 
   {  // -- S e t I t e r a t o r
     Handle<JSObject> set_iterator_prototype =
         isolate->factory()->NewJSObject(isolate->object_function(), TENURED);
     SetObjectPrototype(set_iterator_prototype, iterator_prototype);
     Handle<JSFunction> set_iterator_function = InstallFunction(
         container, "SetIterator", JS_SET_ITERATOR_TYPE, JSSetIterator::kSize,
         set_iterator_prototype, Builtins::kIllegal);
     native_context->set_set_iterator_map(set_iterator_function->initial_map());
@@ skipping 1363 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8