RFR(XXS) : 8199050 : reenable concurrent execution of compiler tests

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev/8199050/webrev.00/
> 3 lines changed: 0 ins; 3 del;

Hi all,

Concurrent execution has been disabled for compiler tests which use JIB b/c JIB wasn't able to perform artifactory installation concurrently. now w/ it being fixed, the tests can be run concurrently.

webrev: http://cr.openjdk.java.net/~iignatyev/8199050/webrev.00/
JBS: https://bugs.openjdk.java.net/browse/JDK-8199050
testing: compiler/aot tests

Thanks,
-- Igor