is_markable_object 2975 gc.c               return is_markable_object(objspace, obj) && is_live_object(objspace, obj);
is_markable_object 4348 gc.c               if (!is_markable_object(objspace, obj)) return;
is_markable_object 7465 gc.c               if (is_markable_object(objspace, obj)) {