[8u40] Request for approval: JDK-8060724: ant test262parallel in Nashorn spends a significant amount of time after almost all the tests are run

[Hannes Wallnoefer]

Please approve backport of JDK-8060724 to 8u40.

Bug: https://bugs.openjdk.java.net/browse/JDK-8060724
Webrev: http://cr.openjdk.java.net/~hannesw/8060724/
Review thread: 
http://mail.openjdk.java.net/pipermail/nashorn-dev/2014-October/003690.html
Changeset: http://hg.openjdk.java.net/jdk9/dev/nashorn/rev/41d4537f8294

The patch applies cleanly to 8u40 after fixing path names.

This is a performance fix specifically for our "test262parallel" test. 
The code pattern is rather unusual for real world apps. I've added the 
noreg-perf label.

Thanks,
Hannes