RFR: 8046817: JDK 8 schemagen tool does not generate xsd files for enum types

[Aleksej Efimov]

Hello,

Please, review the fix [1] for the 8046817 [2].
Problem: schemagen tool doesn't generate schema file for the enum types [3].
SchemaGenerator class gets a list of annotated elements and filters out 
only the class variables, but annotation parser (AnnotationParser.java) 
filters out the Class and Enum. The proposed fix solves the problem: 
SchemaGenerator filters like AnnotationParser.
Testing: JPRT build and test passes on platforms (with new regression 
test). JTREG tests: javax/xml - no failures.

Thanks,
Aleksej

[1] Webrev: http://cr.openjdk.java.net/~aefimov/8046817/9/webrev.00/
[2] Bug: https://bugs.openjdk.java.net/browse/JDK-8046817
[3] Enum type: 
http://cr.openjdk.java.net/~aefimov/8046817/9/webrev.00/jdk/test/javax/xml/ws/8046817/TestEnumType.java.html