RFE JDK-8187698: [Nestmates][Testbug] Test java/lang/invoke/AccessControlTest.java needs updating for nestmates

[mandy chung]

http://cr.openjdk.java.net/~mchung/valhalla/webrevs/8187698/webrev.00/

A simple test fix. Update AccessControlTest test how it determines whether
a test case should have access to handle the nestmates case when accessing
a private member.

Mandy