func setUpval(i Instruction, vm LuaVM) {
	a, b, _ := i.ABC()
	a += 1
	b += 1
	vm.Copy(a, vm.UpvalueIndex(b))
}
UpValue[B] := R(A)
package vm
import . "github.com/zxh0/lua.go/api"
func getUpval(i Instruction, vm LuaVM) {
	a, b, _ := i.ABC()
	a += 1
	b += 1
	vm.Copy(vm.UpvalueIndex(b), a)
}