Review request 8153035: GenModuleInfoSource strips away the API

[Mandy Chung]

GenModuleInfoSource is a build tool that augments module-info.java with platform-specific declaration such as exports, uses and provides and generates the resulting module-info.java in gensrc directory.  This utility should really be a simple one that inserts/appends the extra info to the original module-info.java.  The patch replaces the old code and removes the unused files that were used for modules.xml.

http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8153035/webrev.00/

Mandy