[Bug debug/93951] [8/9/10 Regression] ICE with '-flto -g -femit-struct-debug-baseonly'

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93951

--- Comment #7 from Martin Liška <marxin at gcc dot gnu.org> ---
There's a reduced test-case:

$ cat pr93951.ii
# 2 "" 3
namespace std {
template <typename _Tp> struct A {};
template <typename, typename _Visitor> struct __gen_vtable {
  using _Func_ptr = _Visitor;
  using _Array_type = A<_Func_ptr>;
  static _Array_type m_fn1() {}
  static constexpr auto _S_vtable = m_fn1;
};
template <typename _Visitor> visit(_Visitor) {
  using _Result_type = decltype(0);
  __gen_vtable<_Result_type, _Visitor>::_S_vtable;
}
} // namespace std
struct V {
  m_fn2() {
    auto visitor = [] {};
    std::visit(visitor);
  }
};

Fails with:

$ g++ pr93951.ii -c -g -flto -femit-struct-debug-baseonly -std=c++17
-fno-eliminate-unused-debug-symbols -c

Will you take a look Richi?