New test case.

From-SVN: r21212

gcc/testsuite/g++.old-deja/g++.ns/lookup5.C

@@ -0,0 +1,23 @@
+// Build don't link: 
+namespace A{
+  void f();
+}
+
+namespace B{
+  using namespace A;
+  void f(int);
+}
+
+using namespace B;
+
+void g()
+{
+  ::f();               // ERROR - A::f is not found
+}
+
+using namespace A;
+
+void g1()
+{
+  ::f();               // ok, it is found now
+}