JDK 9 RFR of DK-8176477: Use DirectiveVisitor to print module information

[joe darcy]

Hello,

The printing processor's support for modules ( JDK-8173609 ) was added 
before the directive visitor was added ( JDK-8175118 ).

The printing implementation should be refactored to use the directive 
visitor. Please review the webrev implementation that refactoring:

     http://cr.openjdk.java.net/~darcy/8176477.0/

Thanks,

-Joe