Make generators non-constructable

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index fe813510d50f0070cb4d07c51a5e7a1ff9f1841c..6c03ca315821dae9a07b1496aba36c2841b6ca25 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -821,6 +821,7 @@ void Genesis::CreateIteratorMaps() {
   // 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(
@@ -828,6 +829,7 @@ void Genesis::CreateIteratorMaps() {
 
   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(
@@ -836,6 +838,7 @@ void Genesis::CreateIteratorMaps() {
   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(