re PR c++/3242 (Forwarding using 'using' of base members broken?)

        PR c++/3242
        * class.c (add_method): Do compare 'this' quals when trying to match a
        used function.  Don't defer to another used function.

From-SVN: r48982

gcc/testsuite/g++.dg/inherit/using1.C

+// Test that overloading on 'this' quals works with class using-declarations.
+
+// { dg-do link }
+
+struct A {
+  void f() const;
+  void f() {}
+  void g() const {}
+  void g();
+  void h() const;
+  void h();
+  void i() const;
+  void i() {}
+};
+
+struct B: private A {
+  using A::f;
+  using A::g;
+  void h () const {}
+  using A::h;
+  void i () const {}
+  using A::i;
+};
+
+int main()
+{
+  B b1;
+  const B b2 = B();
+
+  b1.f ();
+  b2.g ();
+  b2.h ();
+  b1.i ();
+}