[PATCH][libxshmfence] configure.ac: call AC_USE_SYSTEM_EXTENSIONS

[Adam Jackson]

On Mon, 2018-01-29 at 16:24 +0000, Ross Burton wrote:
> With glibc 2.27 memfd_create() is inside a _GNU_SOURCE guard, so call
> AC_USE_SYSTEM_EXTENSIONS to get this defined.
> 
> Signed-off-by: Ross Burton <ross.burton at intel.com>

remote: I: patch #201382 updated using rev 0b550a4e7acf02d3478602848f6afbfcbfb0d4b2.
remote: I: 1 patch(es) updated to state Accepted.
To ssh://git.freedesktop.org/git/xorg/lib/libxshmfence
   db7966b..0b550a4  master -> master

- ajax