RFR 8029809: sun/management/jmxremote/bootstrap/CustomLauncherTest.java fails intermittently with "Operation not permitted"

[Jaroslav Bachorik]

Please, review the following test fix.

Issue : https://bugs.openjdk.java.net/browse/JDK-8029809
Webrev: http://cr.openjdk.java.net/~jbachorik/8029809/webrev.00/

CustomLauncherTest.java fails intermittently with "Operation not 
permitted". The root cause is that it is not possible to check in 
executable files - and the test requires launcher executables to 
function properly. The naive approach taken was to add the executable 
flag to the launchers as needed, in-place. It turns out this is not such 
a great idea as documented by the intermediate failures.

The solution is to copy the launcher to the work dir and perform the 
modifications on the copy. The work dir is required to permit writing to 
files so this will resolve the failures.

Thanks,

-JB-