[Bug c++/94553] Revise [basic.scope.declarative]/4.2

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94553

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I think it would make sense to detect this too:

struct E { };
template<typename> concept E = false;
template<typename> concept F = false;
struct F { };