Cygwin: FIFO: add a timeout to take_ownership

fhandler_fifo::take_ownership() is called from select.cc::peek_fifo
and fhandler_fifo::raw_read and could potentially block indefinitely
if something goes wrong.  This is always undesirable in peek_fifo, and
it is undesirable in a nonblocking read.  Fix this by adding a timeout
parameter to take_ownership.

Arbitrarily use a 1 ms timeout in peek_fifo and a 10 ms timeout in
raw_read.  These numbers may have to be tweaked based on experience.

Replace the call to cygwait in take_ownership by a call to WFSO.
There's no need to allow interruption now that we have a timeout.

winsup/cygwin/fhandler.h

@@ -1487,7 +1487,7 @@ public:
   void fifo_client_lock () { _fifo_client_lock.lock (); }
   void fifo_client_unlock () { _fifo_client_lock.unlock (); }
 
-  DWORD take_ownership ();
+  int take_ownership (DWORD timeout = INFINITE);
   void reading_lock () { shmem->reading_lock (); }
   void reading_unlock () { shmem->reading_unlock (); }