add virtual destructors where needed

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@5873 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/cpp_namespace.i

@@ -46,6 +46,7 @@ namespace Foo {
    typedef int Integer;
    class Test2 { 
    public:
+       virtual ~Test2() { }
        virtual char *method() {	
 	 return (char *) "Test2::method";
        }