JRuby 9.3+ fails with Java::JavaLang::ArrayIndexOutOfBoundsException

[sebbASF]

Tests on JRuby 9.3+ are failing with Java::JavaLang::ArrayIndexOutOfBoundsException

This appears to be due to a JRuby bug: https://github.com/jruby/jcodings/issues/25 => https://github.com/jruby/jcodings/issues/26

I don't think there is a work-round, so I think we either need to stop testing on JRuby 9.3+, or allow for such test failures on those versions.

[ahorek]

With recent fixes on the JRuby's side, the test suite is passing again https://github.com/jruby/jruby/issues/7730 So we can close this.