[14] RFR(S/T) : 8235866 : bump jtreg requiredVersion to 4.2b16

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8235866/webrev.00
> 5 lines changed: 0 ins; 0 del; 5 mod

Hi all,

could you please review this small patch which updates TEST.ROOT in all test suites to require jtreg4.2b16?
8230067[1] updated profiles to use jtreg4.2b16, but didn't update TEST.ROOT files. this patch forces all users to have jtreg4.2b16, so there will be no difference in how tests are executed locally and in automated testing infrastructures.

webrev: http://cr.openjdk.java.net/~iignatyev//8235866/webrev.00
JBS: https://bugs.openjdk.java.net/browse/JDK-8235866
[1] https://bugs.openjdk.java.net/browse/JDK-8230067

Thanks,
-- Igor