[Bug c++/67147] [concepts] ICE on checking concept with default template arguments

[andrew.n.sutton at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67147

--- Comment #5 from Andrew Sutton <andrew.n.sutton at gmail dot com> ---
This seems to have been fixed at some point. All examples compile in the
concepts-cxx2a branch.