IO#goto

static VALUE
console_goto(VALUE io, VALUE y, VALUE x)
{
#ifdef _WIN32
    COORD pos;
    int fd = GetWriteFD(io);
    pos.X = NUM2UINT(x);
    pos.Y = NUM2UINT(y);
    if (!SetConsoleCursorPosition((HANDLE)rb_w32_get_osfhandle(fd), pos)) {
        rb_syserr_fail(LAST_ERROR, 0);
    }
#else
    rb_io_write(io, rb_sprintf("\x1b[%d;%dH", NUM2UINT(y)+1, NUM2UINT(x)+1));
#endif
    return io;
}