Review Request: 8150468: ClassCircularityError on error in security policy file

[Sean Mullan]

Please review this fix for https://bugs.openjdk.java.net/browse/JDK-8150468:

     http://cr.openjdk.java.net/~mullan/webrevs/8150468/webrev.00/

The fix is to record bad policy files as they are parsed and ignore them 
during any subsequent permission checks.

Thanks,
Sean