RFR: JDK-8168108: lib/classlist should be packaged in java.base.jmod

[Erik Joelsson]

This patch changes how the dynamically generated lib/classlist is 
packaged. We already create an interim-image from java.base and 
java.logging to generate the classlist during the build. We then copy it 
into the jdk and jre images using makefile logic after jlinking those 
images. With this patch, lib/classlist is instead included in 
java.base.jmod.

To achieve this, I have introduced the concept of interim jmods for the 
jmods used to create the interim-image. These can be built explicitly 
from the top level using targets <module>-interim-jmod. It adds a little 
bit of build time, but it's hardly noticeable.

Bug: https://bugs.openjdk.java.net/browse/JDK-8168108

Webrev: http://cr.openjdk.java.net/~erikj/8168108/webrev.01/

/Erik