xxx! Ignore signal stuff on Mes.

XXX: This is for Mes.  It might be possible to move forward with
broken signal semantics.  We need to test to see if it is worth it
to fix this.

* gash/built-ins/trap.scm (main) [mes]: Do not call 'sigaction'.
* gash/shell.scm (%subshell) [mes]: Do not call 'restore-signals'.

gash/built-ins/trap.scm

@@ -62,7 +62,9 @@
        (for-each (lambda (condition)
                    (match (condition->signum condition)
                      (0 (set-atexit! handler))
-                     (n (sigaction n handler))))
+                     (n (cond-expand
+                         (mes #f)
+                         (else (sigaction n handler))))))
                  conditions))
      EXIT_SUCCESS)
     (_ (format (current-error-port)

gash/shell.scm

@@ -273,7 +273,9 @@ process."
     (0 (dynamic-wind
          (lambda () #t)
          (lambda ()
-           (restore-signals)
+           (cond-expand
+            (mes #f)
+            (else (restore-signals)))
            (set-atexit! #f)
            ;; We need to preserve the status given to 'exit', so we
            ;; catch the 'quit' key here.