Several things have happened recently that affect the compare script's
ability to do clean comparisons for build change verification.
* The SystemModules.class has even more randomness in it and it
currently doesn't look like it can be reliably compared at all.
* The new lib/classlist file may have lines in different order between
builds.
* Support comparing the new licensee-src build mode.
By fixing this I'm again able to do a full -testset buildinfra JPRT
COMPARE_BUILD build using an empty patch and get a clean result.
Bug: https://bugs.openjdk.java.net/browse/JDK-8160728
Webrev: http://cr.openjdk.java.net/~erikj/8160728/webrev.top.01/
/Erik
