Undefine _POSIX_C_SOURCE before redefining in third_party/harfbuzz-ng/src/hb-blob.cc (again).

third_party/harfbuzz-ng/src/hb-blob.cc

 /*
  * Copyright © 2009  Red Hat, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
  *
  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  *
  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * Red Hat Author(s): Behdad Esfahbod
  */
 
 /* http://www.oracle.com/technetwork/articles/servers-storage-dev/standardheaderfiles-453865.html */
+#if defined(_POSIX_C_SOURCE)
+#undef _POSIX_C_SOURCE
+#endif
 #define _POSIX_C_SOURCE 199309L
 
 #include "hb-private.hh"
 
 #include "hb-object-private.hh"
 
 #ifdef HAVE_SYS_MMAN_H
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif /* HAVE_UNISTD_H */
@@ skipping 427 matching lines @@
 
   memcpy (new_data, blob->data, blob->length);
   _hb_blob_destroy_user_data (blob);
   blob->mode = HB_MEMORY_MODE_WRITABLE;
   blob->data = new_data;
   blob->user_data = new_data;
   blob->destroy = free;
 
   return true;
 }