[Bug c++/115898] Invalid use of non-static member function in noexcept is not diagnosed

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115898

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Short testcase:
```
struct f
{
  void g();
  void g(int);
} tt;
bool t = noexcept(tt.g);
```