Added missing test

[SVN r16337]

test/as_to_python_function.cpp

@@ -0,0 +1,14 @@
+// Copyright David Abrahams 2002. Permission to copy, use,
+// modify, sell and distribute this software is granted provided this
+// copyright notice appears in all copies. This software is provided
+// "as is" without express or implied warranty, and with no claim as
+// to its suitability for any purpose.
+
+#include <boost/python/converter/to_python_function_type.hpp>
+
+struct hopefully_illegal
+{
+    static PyObject* convert(int&);
+};
+
+PyObject* x = boost::python::converter::as_to_python_function<int, hopefully_illegal>::convert(0);