Provide psignal() so that we don't get linked against psignal(3).

As there is no real process model currently, just "trap" the signals
appropriately.

sys/rump/librump/rumpkern/emul.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: emul.c,v 1.51 2008/10/10 13:14:41 pooka Exp $	*/
+/*	$NetBSD: emul.c,v 1.52 2008/10/13 11:14:14 pooka Exp $	*/
 
 /*
  * Copyright (c) 2007 Antti Kantee.  All Rights Reserved.
@@ -422,6 +422,18 @@ pg_find(pid_t pid, uint flags)
 	panic("%s: not implemented", __func__);
 }
 
+void
+psignal(struct proc *p, int signo)
+{
+
+	switch (signo) {
+	case SIGSYS:
+		break;
+	default:
+		panic("unhandled signal %d", signo);
+	}
+}
+
 void
 kpsignal(struct proc *p, ksiginfo_t *ksi, void *data)
 {