[Bug c/123036] NaN != NaN should be true, but fails

[janschultke at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123036

--- Comment #1 from Jan Schultke <janschultke at googlemail dot com> ---
Oops the code comment is wrong. Nothing should compare unequal to itself with
ISO/IEC 60559, so it should be:

    static_assert(n != n); // should fail if the previous passes