Add ax_check_{compile,link}_flag.m4

debian/copyright

@@ -86,6 +86,36 @@ License: GPL-3+
  On Debian systems, the complete text of the GNU General
  Public License version 3 can be found in "/usr/share/common-licenses/GPL-3".
 
+Files: m4/ax_check_compile_flag.m4 m4/ax_check_link_flag.m4
+Copyright: 2008 Guido U. Draheim <guidod@gmx.de>
+           2011 Maarten Bosmans <mkbosmans@gmail.com>
+License: GPL-3+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the
+ Free Software Foundation, either version 3 of the License, or (at your
+ option) any later version.
+ .
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ Public License for more details.
+ .
+ You should have received a copy of the GNU General Public License along
+ with this program. If not, see <http://www.gnu.org/licenses/>.
+ .
+ As a special exception, the respective Autoconf Macro's copyright owner
+ gives unlimited permission to copy, distribute and modify the configure
+ scripts that are the output of Autoconf when processing the Macro. You
+ need not follow the terms of the GNU General Public License when using
+ or distributing such scripts, even though portions of the text of the
+ Macro appear in them. The GNU General Public License (GPL) does govern
+ all other use of the material that constitutes the Autoconf Macro.
+ .
+ This special exception to the GPL applies to versions of the Autoconf
+ Macro released by the Autoconf Archive. When you make and distribute a
+ modified version of the Autoconf Macro, you may extend this special
+ exception to the GPL to apply to your modified version as well.
+
 Files: src/crypto/ocb.cc
 Copyright: 2011 Ted Krovetz
 License: ISC