$NetBSD: patch-af,v 1.1 2008/09/05 02:07:51 dholland Exp $

Fix 64-bit build.

--- runtime/io.c~	1997-04-24 10:51:06.000000000 -0400
+++ runtime/io.c	2008-09-04 21:13:01.000000000 -0400
@@ -1,6 +1,7 @@
 /* Buffered input/output. */
 
 #include <errno.h>
+#include <unistd.h>
 #ifdef __MWERKS__
 #include "myfcntl.h"
 #else