[Bug c++/89089] [9 regression] various ICEs in range-v3's 1.0 branch

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89089

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Reduced testcase from #c2, doesn't really need -fconcepts, ICEs also with just
-std=c++17.  Doesn't ICE without no_unique_address, G++ 8 ignores that
attribute with a warning.
template <typename...> struct A {};
template <typename T, typename... U> struct A<T, U...> {
private:
  [[no_unique_address]] A<U...> a;
};
struct B {
  template <typename... U> A<U...> operator()(U...) { return A<U...>(); }
} f;
auto fn = f (int{}, [] {});