disable loading lua bytecode
LUA_API int lua_yield (lua_State *L, int nresults) {
  luai_userstateyield(L, nresults);
  lua_lock(L);
  if (L->nCcalls > L->baseCcalls)
    luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
  L->base = L->top - nresults;  /* protect stack slots below */
  L->status = LUA_YIELD;
  lua_unlock(L);
  return -1;
}

LUA_API int lua_yield (lua_State *L, int nresults) {
  luai_userstateyield(L, nresults);
  lua_lock(L);
  if (L->nCcalls > L->baseCcalls)
    luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
  L->base = L->top - nresults;  /* protect stack slots below */
  L->status = LUA_YIELD;
  lua_unlock(L);
  return -1;
}
