Fix build of spellcheck-tree.c with older gccs

gcc/ChangeLog:
	* spellcheck-tree.c (best_macro_match::best_macro_match):
	Explictly specify the template arguments when invoking the base
	class constructor, to help older C++ compilers.

From-SVN: r238598

gcc/ChangeLog

+2016-07-21  David Malcolm  <dmalcolm@redhat.com>
+
+	* spellcheck-tree.c (best_macro_match::best_macro_match):
+	Explictly specify the template arguments when invoking the base
+	class constructor, to help older C++ compilers.
+
 2016-07-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/71953

gcc/spellcheck-tree.c

@@ -91,7 +91,7 @@ find_closest_macro_cpp_cb (cpp_reader *, cpp_hashnode *hashnode,
 best_macro_match::best_macro_match (tree goal,
 				    edit_distance_t best_distance_so_far,
 				    cpp_reader *reader)
-  : best_match (goal, best_distance_so_far)
+: best_match <goal_t, candidate_t> (goal, best_distance_so_far)
 {
   cpp_forall_identifiers (reader, find_closest_macro_cpp_cb, this);
 }