JDK 9 with drools: Trait tests fail on invokespecial codes

When Drools trait tests tests are executed with JDK 9, some of them fail with errors related to invokespecial codes with similar stacktrace to this [1]. Please see the linked spreadsheet [2] for more information. The spreadsheet contains JDK 9 fails also from other areas.

[1] https://gist.github.com/baldimir/9972c37fe1a1af09bfa0a1605c611306
[2] https://docs.google.com/a/redhat.com/spreadsheets/d/1acFYb9utXhHb3KU2t3FnvTQCmGln9qmC5Aa28UXu3EY/edit?usp=sharing