JDK 9 RFR of JDK-6415644 Make javax.lang.model.SourceVersion more informative

[joe darcy]

Hello,

Please review this webrev to add some version-sensitive keyword and name 
queries:

     JDK-6415644 Make javax.lang.model.SourceVersion more informative

     http://cr.openjdk.java.net/~darcy/6415644.0/

Thanks,

-Joe