libxshmfence: fix glibc-2.27 build

packages/x11/lib/libxshmfence/package.mk

@@ -27,6 +27,7 @@ PKG_DEPENDS_TARGET="toolchain util-macros xproto"
 PKG_SECTION="x11/lib"
 PKG_SHORTDESC="libxshmfence: Shared memory 'SyncFence' synchronization primitive."
 PKG_LONGDESC="libxshmfence is the Shared memory 'SyncFence' synchronization primitive."
+PKG_TOOLCHAIN="autotools"
 
 PKG_CONFIGURE_OPTS_TARGET="--enable-static --disable-shared"
 

packages/x11/lib/libxshmfence/patches/libxshmfence-01-fix-glibc-2.27.patch

@@ -0,0 +1,31 @@
+From 33dc04e9de44aa7a1f72544ce00f2fe239c3a62c Mon Sep 17 00:00:00 2001
+From: MilhouseVH <milhouseVH.github@nmacleod.com>
+Date: Fri, 2 Feb 2018 03:30:53 +0000
+Subject: [PATCH] fix build with glibc 2.27
+
+With glibc 2.27 memfd_create() is behind a _GNU_SOURCE guard, so use
+AC_USE_SYSTEM_EXTENSIONS to define it.
+
+(From OE-Core rev: 88b3d730021107985ea749c92e52a323690f87dc)
+
+Ref: http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=fc56788a3201daf1b1a9f3b96d5501ffe489dcd1
+---
+ configure.ac | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index 0c98875..ebf4dee 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -28,6 +28,8 @@ AC_INIT([libxshmfence], [1.2],
+ AC_CONFIG_SRCDIR([Makefile.am])
+ AC_CONFIG_HEADERS([config.h])
+ 
++AC_USE_SYSTEM_EXTENSIONS
++
+ # Initialize Automake
+ AM_INIT_AUTOMAKE([foreign dist-bzip2])
+ 
+-- 
+2.14.1
+