$NetBSD: patch-configure,v 1.1 2020/09/17 19:43:47 schmonz Exp $

On macOS with clang 12, get explicit definitions of snprintf and
vsnprintf to avoid warnings (treated as errors) and thereby pass
configure.

--- configure.orig	2020-01-16 22:02:50.000000000 +0000
+++ configure
@@ -14045,6 +14045,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdarg.h>
+#include <stdio.h>
                                                   char buf[16];
                                                   va_list ap;
 int
@@ -14074,6 +14075,7 @@ if test "$cross_compiling" = yes; then :
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+#include <stdio.h>
 char buf[4] = "abc";
 int
 main ()
