RFR: JDK-8167488: Race condition in build with new exploded-image-optimize target

[Erik Joelsson]

When introducing the exploded-image-optimize target, I tried to fix all 
the dependencies so that the module-info.class files would not be used 
by any other target at the same time as the optimization was happening. 
It seems I forgot about one class of such uses. Any java compilation 
target that links to the classes in jdk/modules is potentially affected.

This patch addresses all the cases I could find.

Bug: https://bugs.openjdk.java.net/browse/JDK-8167488

Webrev: http://cr.openjdk.java.net/~erikj/8167488/webrev.01/

/Erik