[foreign] RFR 8210650: Cursor.isAnonymousStruct is about embedded anon struct/union and not just name being empty

[Sundararajan Athijegannathan]

Please review.

Bug: https://bugs.openjdk.java.net/browse/JDK-8210650

Webrev: http://cr.openjdk.java.net/~sundar/8210650/webrev.00/

Includes other cleanups regarding equals, toString in Cursor, Type and 
SourceLocation.

Thanks,
-Sundar