$NetBSD: patch-configure,v 1.1 2018/08/06 10:58:42 jperkin Exp $

Set _XOPEN_SOURCE / _POSIX_C_SOURCE correctly.

--- configure.orig	2006-05-22 12:10:32.000000000 +0000
+++ configure
@@ -20107,6 +20107,7 @@ fi
 # We could possibly need struct timespec and random(), which are not ANSI.
 
 cat >>confdefs.h <<\_ACEOF
+#if !defined (__sun) || (__STDC_VERSION__-0 < 199901L)
 #define _XOPEN_SOURCE 500
 _ACEOF
 
@@ -20115,6 +20116,7 @@ _ACEOF
 
 cat >>confdefs.h <<\_ACEOF
 #define _POSIX_C_SOURCE 199309
+#endif
 _ACEOF