Warnings in testcases fix

Examples/test-suite/cpp11_ref_qualifiers.i

@@ -90,9 +90,11 @@ struct Renames {
 struct ConversionOperators {
   virtual operator string() & { return string(); }
   virtual operator string() && { return std::move(string()); }
+  virtual ~ConversionOperators() {}
 };
 struct ConversionOperators2 {
   virtual operator string() && { return std::move(string()); }
+  virtual ~ConversionOperators2() {}
 };
 %}
 

Examples/test-suite/template_empty_inherit.i

@@ -5,6 +5,7 @@
 %inline %{
 template<class Arg, typename Result> struct Functor {
   virtual Result operator()(Arg x) const = 0;
+  virtual ~Functor() {}
 };
 %}