Libvtv-test: Fix bug that scansarif.exp cannot be found in libvtv regression test.

	SARIF support was added in r13-967 but libvtv wasn't updated.

libvtv/ChangeLog:

	* testsuite/lib/libvtv-dg.exp: Add load_gcc_lib of scansarif.exp.

libvtv/testsuite/lib/libvtv-dg.exp

@@ -12,6 +12,8 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
+load_gcc_lib scansarif.exp
+
 proc libvtv-dg-test { prog do_what extra_tool_flags } {
     return [gcc-dg-test-1 libvtv_target_compile $prog $do_what $extra_tool_flags]
 }