fprintf(fp, "\n" "JSObject classes\n");
            if (obj_classes[0])
                fprintf(fp, "  %5d  %2.0d %s\n", obj_classes[0], 0, "none");
            for (class_id = 1; class_id < JS_CLASS_INIT_COUNT; class_id++) {
                if (obj_classes[class_id]) {
                    char buf[ATOM_GET_STR_BUF_SIZE];
                    fprintf(fp, "  %5d  %2.0d %s\n", obj_classes[class_id], class_id,
                            JS_AtomGetStrRT(rt, buf, sizeof(buf), js_std_class_def[class_id - 1].class_name));
                }
            }

promise define in another array
>static JSClassShortDef const js_async_class_def[] = {
    { JS_ATOM_Promise, js_promise_finalizer, js_promise_mark },                      /* JS_CLASS_PROMISE */
    { JS_ATOM_PromiseResolveFunction, js_promise_resolve_function_finalizer, js_promise_resolve_function_mark }, /* JS_CLASS_PROMISE_RESOLVE_FUNCTION */
    { JS_ATOM_PromiseRejectFunction, js_promise_resolve_function_finalizer, js_promise_resolve_function_mark }, /* JS_CLASS_PROMISE_REJECT_FUNCTION */
    { JS_ATOM_AsyncFunction, js_bytecode_function_finalizer, js_bytecode_function_mark },  /* JS_CLASS_ASYNC_FUNCTION */
    { JS_ATOM_AsyncFunctionResolve, js_async_function_resolve_finalizer, js_async_function_resolve_mark }, /* JS_CLASS_ASYNC_FUNCTION_RESOLVE */
    { JS_ATOM_AsyncFunctionReject, js_async_function_resolve_finalizer, js_async_function_resolve_mark }, /* JS_CLASS_ASYNC_FUNCTION_REJECT */
    { JS_ATOM_empty_string, js_async_from_sync_iterator_finalizer, js_async_from_sync_iterator_mark }, /* JS_CLASS_ASYNC_FROM_SYNC_ITERATOR */
    { JS_ATOM_AsyncGeneratorFunction, js_bytecode_function_finalizer, js_bytecode_function_mark },  /* JS_CLASS_ASYNC_GENERATOR_FUNCTION */
    { JS_ATOM_AsyncGenerator, js_async_generator_finalizer, js_async_generator_mark },  /* JS_CLASS_ASYNC_GENERATOR */
};

                if (obj_classes[class_id] && class_id < countof(js_std_class_def)) {