Fix PR c++/42634

gcc/cp/ChangeLog:
    PR c++/42634
    * error.c (dump_template_parms): Use innermost template
    arguments before calling count_non_default_template_args.
    (count_non_default_template_args): We are being called with
    template innermost arguments now. There is no need to ensure
    that again.

gcc/testsuite/ChangeLog:
    PR c++/42634
    * g++.dg/template/error45.C: New test.

From-SVN: r156022