Compatibility improvements

lib/utils/mem.c

 /*
- * SPDX-FileCopyrightText: 2018, 2019 Bruce Cowan <bruce@bcowan.me.uk>
+ * SPDX-FileCopyrightText: 2018-2020 Bruce Cowan <bruce@bcowan.me.uk>
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 
 #include "config.h"
+
+#ifdef HAVE_REALLOCARRAY
+  #define _GNU_SOURCE
+#endif
+
 #include "mem.h"
 
 #include <stdlib.h>

meson.build

@@ -2,7 +2,8 @@
 # SPDX-License-Identifier: CC0-1.0
 
 project('stdlib', 'c',
-  default_options: ['warning_level=3', 'c_std=gnu99'])
+  default_options: ['warning_level=3', 'c_std=gnu99'],
+  meson_version: '>=0.50.0')
 
 cc = meson.get_compiler('c')
 libm = cc.find_library('m')