* sigproc.cc (cygWFMO): Don't assume that cancellable event is always

* sigproc.cc (cygWFMO): Don't assume that cancellable event is always
available.
* fhandler_dsp.cc (fhandler_dev_dsp::Audio_out::waitforspace): Use cygWFMO
instead of WaitForMultipleObjects.
(fhandler_dev_dsp::Audio_in::waitfordata): Ditto.
* fhandler_fifo.cc (fhandler_fifo::wait): Ditto.
* fhandler_serial.cc (fhandler_serial::raw_read): Ditto.
(fhandler_serial::raw_write): Ditto.
* fhandler_tty.cc (fhandler_pty_slave::read): Ditto.
* select.cc (cygwin_select): Ditto for degenerate case.