I have a stripped down test project which contains a Servlet version 3.0, declared with annotations like so:
@WebServlet(\"/test\")
public class TestServ
I think in 8.5 and later it's just one liner:
Context.setAddWebinfClassesResources(true);
Sets the flag that indicates if /WEB-INF/classes should be treated like an exploded JAR and JAR resources made available as if they were in a JAR.
http://tomcat.apache.org/tomcat-8.5-doc/api/org/apache/catalina/core/StandardContext.html#setAddWebinfClassesResources(boolean)