bool has_body(JSObject *obj) {
  MOZ_ASSERT(is_instance(obj));
  return JS::GetReservedSlot(obj, Slots::HasBody).toBoolean();
}
bool has_body(JSObject *obj) {
  MOZ_ASSERT(is_instance(obj));
  return JS::GetReservedSlot(obj, Slots::HasBody).toBoolean();
}