Make generators non-constructable

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 803 matching lines @@
                         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
   // Create maps for generator functions and their prototypes.  Store those
   // maps in the native context. The "prototype" property descriptor is
   // writable, non-enumerable, and non-configurable (as per ES6 draft
   // 04-14-15, section 25.2.4.3).
   Handle<Map> strict_function_map(strict_function_map_writable_prototype_);
   // Generator functions do not have "caller" or "arguments" accessors.
   Handle<Map> sloppy_generator_function_map =
       Map::Copy(strict_function_map, "SloppyGeneratorFunction");
+  sloppy_generator_function_map->set_is_constructor(false);
   Map::SetPrototype(sloppy_generator_function_map,
                     generator_function_prototype);
   native_context()->set_sloppy_generator_function_map(
       *sloppy_generator_function_map);
 
   Handle<Map> strict_generator_function_map =
       Map::Copy(strict_function_map, "StrictGeneratorFunction");
+  strict_generator_function_map->set_is_constructor(false);
   Map::SetPrototype(strict_generator_function_map,
                     generator_function_prototype);
   native_context()->set_strict_generator_function_map(
       *strict_generator_function_map);
 
   Handle<Map> strong_function_map(native_context()->strong_function_map());
   Handle<Map> strong_generator_function_map =
       Map::Copy(strong_function_map, "StrongGeneratorFunction");
+  strong_generator_function_map->set_is_constructor(false);
   Map::SetPrototype(strong_generator_function_map,
                     generator_function_prototype);
   native_context()->set_strong_generator_function_map(
       *strong_generator_function_map);
 
   Handle<JSFunction> object_function(native_context()->object_function());
   Handle<Map> generator_object_prototype_map = Map::Create(isolate(), 0);
   Map::SetPrototype(generator_object_prototype_map, generator_object_prototype);
   native_context()->set_generator_object_prototype_map(
       *generator_object_prototype_map);
@@ skipping 2514 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8