Handle libbacktrace in contrib/gcc_update

	contrib/
	* gcc_update (files_and_dependencies): Handle libbacktrace.

From-SVN: r253346

contrib/ChangeLog

+2017-10-02  Thomas Schwinge  <thomas@codesourcery.com>
+
+	* gcc_update (files_and_dependencies): Handle libbacktrace.
+
 2017-09-18  Richard Biener  <rguenther@suse.de>
 
 	* download_prerequisites (isl): Bump version to 0.18.

contrib/gcc_update

@@ -168,6 +168,10 @@ liboffloadmic/configure: liboffloadmic/configure.ac
 liboffloadmic/plugin/aclocal.m4: liboffloadmic/plugin/configure.ac
 liboffloadmic/plugin/Makefile.in: liboffloadmic/plugin/Makefile.am
 liboffloadmic/plugin/configure: liboffloadmic/plugin/configure.ac
+libbacktrace/aclocal.m4: libbacktrace/configure.ac
+libbacktrace/Makefile.in: libbacktrace/Makefile.am libbacktrace/aclocal.m4
+libbacktrace/configure: libbacktrace/configure.ac libbacktrace/aclocal.m4
+libbacktrace/config.h.in: libbacktrace/configure.ac libbacktrace/aclocal.m4
 # Top level
 Makefile.in: Makefile.tpl Makefile.def
 configure: configure.ac config/acx.m4