Add test

From-SVN: r19884

gcc/testsuite/g++.old-deja/g++.other/overload2.C

+// Build don't run:
+
+template <class T>
+class ConstArray {
+};
+
+template <class T1, class T2>
+void operator+(const ConstArray<T1>&, const ConstArray<T2>&)
+{
+}
+
+template <class T1, class T2>
+void operator+(const ConstArray<T1>&, T2);
+
+template <class T1, class T2>
+void operator+(T1, const ConstArray<T2>&);
+
+const ConstArray<int> cai() { return ConstArray<int>(); }
+const ConstArray<double> cad() { return ConstArray<double>(); }
+
+int main()
+{
+  cai () + cad ();
+}