use (void*) NULL in execl to make sure it's 64-bit where it needs to be

www/php4/extensions/patches/patch-ext_standard_exec_c

@@ -0,0 +1,12 @@
+$OpenBSD: patch-ext_standard_exec_c,v 1.1 2004/04/15 00:43:43 jolan Exp $
+--- ext/standard/exec.c.orig	2003-11-19 09:34:36.000000000 -0600
++++ ext/standard/exec.c	2004-04-14 19:40:37.000000000 -0500
+@@ -942,7 +942,7 @@ PHP_FUNCTION(proc_open)
+ 				close(descriptors[i].childend);
+ 		}
+ 
+-		execl("/bin/sh", "sh", "-c", command, NULL);
++		execl("/bin/sh", "sh", "-c", command, (void *)NULL);
+ 		_exit(127);
+ 
+ 	} else if (child < 0) {