[12] RFR JDK-8202941: GenModuleInfoSource build tool does not detect missing semicolons

[mandy chung]

GenModuleInfoSource build tool augments module-info.java to include
platform-specific qualified exports/opens and uses/provides services.
This fixes the build tool to catch syntax errors as closely as javac
does. The build tool remains to allow duplicated provides until
JDK-8208463 is resolved.

http://cr.openjdk.java.net/~mchung/jdk12/webrevs/8202941/webrev.00/

Mandy