RFR: 8214795: Add safety check to dynalink inner class lookup

[Hannes Wallnöfer]

Please review:

Bug: https://bugs.openjdk.java.net/browse/JDK-8214795
Webrev: http://cr.openjdk.java.net/~hannesw/8214795/webrev.00/

This is to make sure we use the right inner classes regardless of the order of classes returned by Class.getClasses().

Thanks,
Hannes