IO#check_winsize_changed

static VALUE
console_check_winsize_changed(VALUE io)
{
    HANDLE h;
    DWORD num;

    h = (HANDLE)rb_w32_get_osfhandle(GetReadFD(io));
    while (GetNumberOfConsoleInputEvents(h, &num) && num > 0) {
        INPUT_RECORD rec;
        if (ReadConsoleInput(h, &rec, 1, &num)) {
            if (rec.EventType == WINDOW_BUFFER_SIZE_EVENT) {
                rb_yield(Qnil);
            }
        }
    }
    return io;
}