[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257

[rafael at espindo dot la]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645

--- Comment #8 from Rafael Avila de Espindola <rafael at espindo dot la> ---
The internal compiler error reduces to

struct unordered_map {
    int cend() const noexcept;
};
template <typename a> concept HasMapInterface = requires(a t) { t.cend(); };
template <typename Mapper>
requires HasMapInterface<decltype(Mapper::map())> struct l {
    friend void foo(l opt) {
      ([]() {})();
  }
};
struct p {
  static unordered_map map();
};
void g(l<p> *y) { foo(*y); }