RFR(S) [13] : 8158048 : Fix failure message from jtreg gtest wrapper

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8158048/webrev.00
> 125 lines changed: 108 ins; 10 del; 7 mod


Hi all,

could you please review this small fix which improves error message generated by jtreg gtest wrapper? now we try to parse xml file generated by gtest in order to get more meaningful error message which will include name of all failed tests.

webrev: http://cr.openjdk.java.net/~iignatyev//8158048/webrev.00
JBS: https://bugs.openjdk.java.net/browse/JDK-8158048
testing: manually modified a few tests to fail and checked thrown exception message

Thanks,
-- Igor