A couple of realloc fixes and add warning options

lib/utils/mem.c

@@ -17,6 +17,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#ifdef HAVE_REALLOCARRAY
+  #define _GNU_SOURCE
+#endif
+
 #include "config.h"
 #include "mem.h"
 
@@ -57,5 +61,5 @@ check_reallocarray (void   *ptr,
   if (!new)
     exit (EXIT_FAILURE);
 
-  return ptr;
+  return new;
 }

meson.build

 project('stdlib', 'c',
-  default_options: ['c_std=gnu99'])
+  default_options: ['warning_level=3', 'c_std=gnu99'])
 
 cc = meson.get_compiler('c')
 libm = cc.find_library('m')