* class.c (dfs_find_final_overrider): Fix logic.

        * class.c (update_vtable_entry_for_fn): Uncomment optimization to use
        virtual thunk instead of non-virtual.
        (get_matching_virtual): Uncomment.

        * pt.c (unify): Don't recurse between the POINTER_TYPE and the
        OFFSET_TYPE.  If we're adding cv-quals, the extra ones would be on
        PARM, not ARG.

From-SVN: r43372