Add a comment about why autoreconf is necessary

xorg-x11-proto-devel.spec

@@ -85,8 +85,11 @@ popd
 for dir in $(ls -1) ; do
 	pushd $dir
         [ -e configure ] || ./autogen.sh
-	# yes, this looks horrible, but it's to get the .pc files in datadir
+	# this is necessary for aarch64 support do not remove until all
+	# Sources have seen a new upstream release generated with a new
+	# enough autotools (rhbz#926827)
 	autoreconf -vif
+	# yes, this looks horrible, but it's to get the .pc files in datadir
 	%configure --libdir=%{_datadir} --without-xmlto
 	make %{?_smp_mflags}
 	# XXX presentproto, dri3proto missing this initially