RFR(S): 8160276 - Jittester: bytecode tests generation hangs in ClassWriter infinite loop

[Dmitrij Pochepko]

Hi,

please review fix for 8160276 - Jittester: bytecode tests generation 
hangs in ClassWriter infinite loop

Jittester hangs in rare cases of specific seeds, so, fix launch test 
generation in separate thread and check for generation timeout. Test is 
generated again with next seed in case timeout was hit.

webrev: http://cr.openjdk.java.net/~dpochepk/8160276/webrev.01/
CR: https://bugs.openjdk.java.net/browse/JDK-8160276

I've tested it locally on linux-amd64.

Thanks,
Dmitrij