/// <summary>
/// setupval指令，将寄存器的值赋值给upval，a指定寄存器索引，b指定upval索引，c没用
/// </summary>
/// <param name="i"></param>
public void SetUpval(Instruction i)
{
int a = 0, b = 0, c = 0;
i.ABC(ref a, ref b, ref c);
luaState.SetUpval(b, luaState.Get(a + 1));
}
