[PATCH libXt] asprintf needs _GNU_SOURCE on some platforms

[Rob Clark]

Fixes a build break noticed on fedora 21 on arm (although I doubt that
is in any way arch specific).

http://tinderbox.x.org/builds/2015-01-26-0012/logs/libXt/#build

Signed-off-by: Rob Clark <robdclark at gmail.com>

---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 3633ec6..e60e88d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -66,7 +66,7 @@ fi
 AC_SUBST([CC_FOR_BUILD])
 DEFAULT_CPPFLAGS_FOR_BUILD="${CPPFLAGS}"
 AC_CHECK_FUNC(asprintf,
-  [DEFAULT_CPPFLAGS_FOR_BUILD="${DEFAULT_CPPFLAGS_FOR_BUILD} -DHAVE_ASPRINTF"])
+  [DEFAULT_CPPFLAGS_FOR_BUILD="${DEFAULT_CPPFLAGS_FOR_BUILD} -DHAVE_ASPRINTF -D_GNU_SOURCE"])
 CPPFLAGS_FOR_BUILD=${CPPFLAGS_FOR_BUILD-${DEFAULT_CPPFLAGS_FOR_BUILD}}
 AC_SUBST(CPPFLAGS_FOR_BUILD)
 DEFAULT_CFLAGS_FOR_BUILD="${CFLAGS} ${CWARNFLAGS}"
-- 
2.1.0