* DevNotes: Add entry cgf-000017.

* _cygtls.cc (_cygtls::call2): Use new exit_thread function in place of
ExitThread.
* miscfuncs.cc (thread_wrapper): Ditto.
* thread.cc (pthread::exit): Ditto.
(pthread_mutex::unlock): Set tid to NULL rather than 0.
(pthread_spinlock::unlock): Ditto.
* pinfo.cc (commune_process): Actually call lock_process constructor.
* sigproc.cc (exit_thread): New function.
(wait_sig): Handle __SIGTHREADEXIT case.  Don't just block rather than
returning from this function.
* sigproc.h (__SIGTHREADEXIT): New enum.
(exit_thread): Declare.
* sync.cc (muto::release): Accept a tls command-line argument.
* sync.h (muto::release): Accept a tls command-line parameter.  Default to
&_my_tls.

winsup/cygwin/sync.h

@@ -33,7 +33,7 @@ public:
   ~muto ()
 #endif
   int acquire (DWORD ms = INFINITE) __attribute__ ((regparm (2))); /* Acquire the lock. */
-  int release () __attribute__ ((regparm (1)));		     /* Release the lock. */
+  int release (_cygtls * = &_my_tls) __attribute__ ((regparm (2))); /* Release the lock. */
 
   bool acquired () __attribute__ ((regparm (1)));
   void upforgrabs () {tls = this;}  // just set to an invalid address
@@ -60,6 +60,7 @@ public:
     if (!skip_unlock)
       locker.release ();
   }
+  static void force_release (_cygtls *tid) {locker.release (tid);}
   friend class dtable;
   friend class fhandler_fifo;
 };