RFR findWither with access checks

[Paul Sandoz]

http://cr.openjdk.java.net/~psandoz/valhalla/findWither-access/webrev/ <http://cr.openjdk.java.net/~psandoz/valhalla/findWither-access/webrev/>

Updates findWither to grant access if the lookup class is VCC or DVT with private access.

Paul.