[8u] approval request for 8158467: AccessControlException is thrown on public Java class access if "script app loader" is set to null

[Sundararajan Athijegannathan]

Please approve.

bug: https://bugs.openjdk.java.net/browse/JDK-8158467

jdk9 review thread: 
http://mail.openjdk.java.net/pipermail/nashorn-dev/2016-June/006274.html

jdk8u webrev: http://cr.openjdk.java.net/~sundar/8158467/8u/webrev.00/

Backported "as is" except for modular source layout difference.

-Sundar