[Bug c++/82380] [concepts] Error when using requires constraint with attributes

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82380

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I tested it with "concept" not "concept bool" i.e.

template <class T>
concept C = true;

template <class T>
  requires C<T>
[[nodiscard]] int f(T t) {
  return 22;
}

int main() {
  return 0;
}