Calling a generator function returns a generator object

src/objects-printer.cc

Index: src/objects-printer.cc
diff --git a/src/objects-printer.cc b/src/objects-printer.cc
index 834223261f301a88af8912c43f24da913ca7e93a..64b688a0911161c59c0878149c851666ae417833 100644
--- a/src/objects-printer.cc
+++ b/src/objects-printer.cc
@@ -132,6 +132,7 @@ void HeapObject::HeapObjectPrint(FILE* out) {
     case JS_OBJECT_TYPE:  // fall through
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
     case JS_ARRAY_TYPE:
+    case JS_GENERATOR_ITERATOR_TYPE:
     case JS_REGEXP_TYPE:
       JSObject::cast(this)->JSObjectPrint(out);
       break;
@@ -530,6 +531,7 @@ static const char* TypeToString(InstanceType type) {
     case ODDBALL_TYPE: return "ODDBALL";
     case JS_GLOBAL_PROPERTY_CELL_TYPE: return "JS_GLOBAL_PROPERTY_CELL";
     case SHARED_FUNCTION_INFO_TYPE: return "SHARED_FUNCTION_INFO";
+    case JS_GENERATOR_ITERATOR_TYPE: return "JS_GENERATOR_ITERATOR";
     case JS_MODULE_TYPE: return "JS_MODULE";
     case JS_FUNCTION_TYPE: return "JS_FUNCTION";
     case CODE_TYPE: return "CODE";