C++: use struct_tag type

Author: Daniel Kroening

src/cpp/cpp_typecheck_resolve.h

@@ -71,7 +71,7 @@ class cpp_typecheck_resolvet
     resolve_identifierst &identifiers,
     const wantt want);
 
-  symbol_typet disambiguate_template_classes(
+  struct_tag_typet disambiguate_template_classes(
     const irep_idt &base_name,
     const cpp_scopest::id_sett &id_set,
     const cpp_template_args_non_tct &template_args);