* cygerrno.h (geterrno_from_nt_status): Declare.
* errno.cc (geterrno_from_nt_status): Define.
* flock.cc: Fix copyright dates.
* ntdll.h (enum _TIMER_TYPE): Define.
(PTIMER_APC_ROUTINE): Define.
(NtCancelTimer): Declare.
(NtCreateTimer): Declare.
(NtSetTimer): Declare.
* posix_ipc.cc (ipc_cond_timedwait): Rewrite to make interruptible and
restartable. Call pthread_testcancel in case of timeout to enable
pthread_cancel on waiting thread. Replace WFMO timeout with waiting
for a waitable timer. Explain why. Replace single call to WFMO with
two calls, one for the event, one for the mutex. Don't lock mutex in
case of error.
(ipc_cond_signal): Make void function.
(ipc_cond_close): Ditto.
(_mq_send): Immediately return -1 in case of error from
ipc_cond_timedwait.
(_mq_receive): Ditto.