Please publish JDK 9 Automatic-Module-Name entries

<!--

Before submitting an issue to ANTLR, please check off these boxes:

 

- [✓] I am not submitting a question on how to use ANTLR; instead, go to [antlr4-discussion google group](https://groups.google.com/forum/#!forum/antlr-discussion) or ask at [stackoverflow](http://stackoverflow.com/questions/tagged/antlr4)

- [✓] I have done a search of the existing issues to make sure I'm not sending in a duplicate



Please include information about the expected behavior, actual behavior, and the smallest grammar or code that reproduces the behavior. If appropriate, please indicate the code generation targets such as Java, C#, ...  Pointers into offending code regions are also very welcome.

-->



The jar files (particularly for the runtime) should contain `Automatic-Module-Name` entries so that modular JDK 9 projects have a stable name to use in module `requires` clauses. I'd suggest `org.antlr.antlr4.runtime` as this is close to what you're already using as the OSGi symbolic name, but with the hyphen replaced with a dot (module names at the language level can't contain hyphens).



I can submit a PR to make the changes if you like. My current interest in this is getting [jgrapht modularized](https://github.com/jgrapht/jgrapht/issues/448).

[]