RFR: JDK-8058118: Generate modules.list during the build

[Tim Bell]

  Hi Erik:

> The checked in modules.list file defines the dependencies between 
> modules for the build. The dependency information in this file is 
> already captured in the modules.xml. Rather than keeping two copies of 
> this information, with this change, modules.list is generated during 
> the build.
>
> Chris provided the java implementation for the actual list generation. 
> I've made the makefile changes.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8058118
> Webrevs: http://cr.openjdk.java.net/~erikj/8058118

Looks good to me.

/Tim