"Access to a private member" build failure(s) — clang 8.0.1

This code is accepted by g++ but refused by clang.
gcc bug #52373 has been reported, which is a duplicate of the bug #41437.
class A
{
    struct st
    {
        static void f();
    };
};

template <typename t> void foo()
{
    A::st::f();
}

No error detected for version 8.0.1