[Bug c++/104141] New: Access to private member function from requires-clause accepted

[fchelnokov at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141

            Bug ID: 104141
           Summary: Access to private member function from requires-clause
                    accepted
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fchelnokov at gmail dot com
  Target Milestone: ---

This is invalid code:
```
class A{
   static void f();
};
static_assert( requires{ !requires{ A::f(); }; } );
```
and rejected by Clang and MSVC due to access to a private member function. But
GCC accepts it. Demo: https://gcc.godbolt.org/z/76jhYav4v