RFR 8191416: (bf) DirectByteBuffer extends MappedByteBuffer, confuses instanceof tests

[Roger Riggs]

Hi Brian,

Looks fine.

(I'm not sure I would describe the behavior as a no-op; since I think 
they do achieve the invariant as defined).

Roger

On 2/5/2018 8:17 PM, Brian Burkhalter wrote:
> https://bugs.openjdk.java.net/browse/JDK-8191416
> http://cr.openjdk.java.net/~bpb/8191416/webrev.00/
>
> As suggested in the issue description, change force(), load(), and isLoaded() to be no-ops when there is no backing file instead of throwing UnsupportedOperationException.
>
> Thanks,
>
> Brian