$NetBSD: patch-configure.ac,v 1.1 2021/05/03 08:34:37 wiz Exp $

This fixes build failure for latest source with autoconf. Add the check
glib-mkenums and definition of GLIB_MKENUMS to configure.ac

https://gitlab.freedesktop.org/farstream/farstream/-/commit/f047f4f6640146dda90cf9c87565fd61a3edeee8

--- configure.ac.orig	2020-03-11 23:26:39.000000000 +0000
+++ configure.ac
@@ -264,6 +264,12 @@ FS_PREFIX="`$PKG_CONFIG --variable=prefi
 AC_SUBST(GLIB_PREFIX)
 AC_SUBST(FS_PREFIX)
 
+dnl Check for glib-2.0 tools
+AC_MSG_CHECKING([for glib-mkenums])
+GLIB_MKENUMS="`$PKG_CONFIG --variable=glib_mkenums glib-2.0`"
+AC_SUBST(GLIB_MKENUMS)
+AC_MSG_RESULT($GLIB_MKENUMS)
+
 dnl *** set variables based on configure arguments ***
 
 dnl set license and copyright notice