8236582: (fc) FileChannel.map fails with InternalError when security manager enabled

[Brian Burkhalter]

This issue [1] is caused by using privateLookupIn() outside a privileged block. The patch [2] fixes this. The added test fails without the source patch but passes with it.

Thanks,

Brian

[1] https://bugs.openjdk.java.net/browse/JDK-8236582
[2] http://cr.openjdk.java.net/~bpb/8236582/webrev.00/