RFR: CODETOOLS-7902215: Follow-up generification and misc, part 3

[dmitry.bessonov at oracle.com]

Please review the following follow-up fix related to generics usage in 
JTHarness code; also compatibility with JTReg codebase has been restored.

JBS: https://bugs.openjdk.java.net/browse/CODETOOLS-7902215
Webrev: http://cr.openjdk.java.net/~dbessono/7902215/webrev/


dmitry