RFR CODETOOLS-7902542: jtreg plugin broken with IntelliJ 2019.3

[Maurizio Cimadamore]

Hi,
the pluging no longer works due to a missing abstract method 
implementation. In reality the implementation is there, but since the 
signature of the method has changed, the implementation is no longer 
recognized as such. For now I opted for a simple solution which 
implements the new signature and forwards back to the old one.

Both are kept in place (and @Override) is removed on both, to preserve 
backwards compatibility as much as possible.

Webrev:

http://cr.openjdk.java.net/~mcimadamore/jtreg/7902542/

Maurizio