* cygthread.cc (cygthread::detach): Make error message a little more detailed.

* fhandler.cc (fhandler_base::raw_read): Ditto for debug message.
* dcrt0.cc (do_exit): Add some more synchronization tests.
* fhandler_fifo.cc (fhandler_fifo::dup): Don't duplicate a nonexistent handle.
Use derived return value rather than always retuning 0.
* fhandler_netdrive.cc (fhandler_netdrive::exists): Wnet -> WNet.
* winsup.h (exit_states): Add a couple of new exit states.

winsup/cygwin/winsup.h

@@ -187,6 +187,8 @@ extern "C" int dll_noncygwin_dllcrt0 (HMODULE, per_process *);
 enum exit_states
   {
     ES_NOT_EXITING = 0,
+    ES_SET_MUTO,
+    ES_GLOBAL_DTORS,
     ES_EVENTS_TERMINATE,
     ES_THREADTERM,
     ES_SIGNAL,