* external.cc (cygwin_internal): Add CW_INIT_EXCEPTIONS to allow cygwin

exception handling on threads not created by cygwin.
* sigproc.cc (proc_terminate): Don't release pinfo structs since we are
exiting.
* include/sys/cygwin.h: Add CW_INIT_EXCEPTIONS.

winsup/cygwin/dcrt0.cc

@@ -1042,7 +1042,7 @@ do_exit (int status)
     }
 
   if (cleanup_pinfo)
-    myself->record_death ();	// Locks pinfo mutex
+    myself->record_death ();
   else
     sigproc_printf ("not cleanup_pinfo");