Make data members protected instead of private (#4284)

src/ngraph/runtime/executable.hpp

@@ -165,7 +165,6 @@ protected:
     /// \param func The function with Results fully resolved.
     void set_parameters_and_results(const Function& func);
 
-private:
     ngraph::ParameterVector m_parameters;
     ngraph::ResultVector m_results;
 };