RFR(XS): 8163366 - compiler/codecache/jmx/ThresholdNotificationsTest.java doesn't set -XX:+UnlockDiagnosticVMOptions while using WB

[Dmitrij Pochepko]

Hi,

please review small fix for 8163366 - 
compiler/codecache/jmx/ThresholdNotificationsTest.java doesn't set 
-XX:+UnlockDiagnosticVMOptions while using WB

Test failed on product build because of missing 
UnlockDiagnosticVMOptions flag.

webrev: http://cr.openjdk.java.net/~dpochepk/8163366/webrev.01/
CR: https://bugs.openjdk.java.net/browse/JDK-8163366

I've tested it on linux-amd64.

Thanks,
Dmitrij