* dcrt0.cc (do_exit): Eliminate "C" linkage. Call events_terminate early.

(exit_states): Move out of source file into header file.
* winsup.h: Move exit_states here.  Remove "C" linkage from do_exit
declaration.
* debug.cc (lock_debug): Remove explicit (and incorrect) external for
exit_state.
* sigproc.cc (sig_dispatch_pending): Don't flush signals if exiting.

winsup/cygwin/debug.cc

@@ -36,7 +36,6 @@ class lock_debug
  public:
   lock_debug () : acquired (0)
   {
-    extern int exit_state;
     if (locker && !exit_state)
       acquired = !!locker->acquire (INFINITE);
   }