Backport relevant test changes & additions from JDK-8130125

The main focus of JDK-8130125 is irrelevant to 8u, as it concerns the introduction of the module system. However, the change was also used to introduce a number of other test changes and open up three tests [0]. We should backport those parts of the change to 8u.

[0] https://mail.openjdk.java.net/pipermail/awt-dev/2015-July/009588.html