hg: jdk9/dev/langtools: 6415644: Make javax.lang.model.SourceVersion more informative

[joe.darcy at oracle.com]

Changeset: d6224976006a
Author:    darcy
Date:      2016-05-20 17:00 -0700
URL:       http://hg.openjdk.java.net/jdk9/dev/langtools/rev/d6224976006a

6415644: Make javax.lang.model.SourceVersion more informative
Reviewed-by: jjg

! src/java.compiler/share/classes/javax/lang/model/SourceVersion.java
! test/tools/javac/processing/model/TestSourceVersion.java