Method xzero

pulley/src/interp.rs:1676–1679

(&mut self, dst: XReg)

    }

    fn xzero(&mut self, dst: XReg) -> ControlFlow<Done> {
        self.state[dst].set_i64(0);
        ControlFlow::Continue(())
    }

    fn xone(&mut self, dst: XReg) -> ControlFlow<Done> {
        self.state[dst].set_i64(1);