RFR(XS): 8159803 - Jittester: FileAlreadyExists exception during tests generation

[Dmitrij Pochepko]

Hi all,

please review small fix for 8159803 - Jittester: FileAlreadyExists 
exception during tests generation

A jittester rarely throws FileAlreadyExistsException while generating 
tests. This was caused by nonsuccessive generated test run. Such 
situation trigger test re-generation which fails because test file 
already exists. I've fixed this issue.

webrev: http://cr.openjdk.java.net/~dpochepk/8159803/webrev.01/
CR: https://bugs.openjdk.java.net/browse/JDK-8159803

I've tested this locally on linux-amd64

Thanks,
Dmitij