Added code to insure that the post switch extension was executed and

to made signals sent to a particular thread from an ISR operated correctly.
This behavior was required by the exception detection/reporting code
in the gnat runtime.

c/src/exec/posix/src/psignal.c

@@ -1285,6 +1285,11 @@ int pthread_kill(
         api->signals_pending |= signo_to_mask( sig );
 
         (void) _POSIX_signals_Unblock_thread( the_thread, sig, NULL );
+
+        the_thread->do_post_task_switch_extension = TRUE;
+
+        if ( _ISR_Is_in_progress() && _Thread_Is_executing( the_thread ) )
+          _ISR_Signals_to_thread_executing = TRUE;
       }
       _Thread_Enable_dispatch();
       return 0;