[9] RFR (XS): 8169000: Define reference reachability more precisely in java.lang.ref package

[Mandy Chung]

> On Nov 16, 2016, at 12:41 AM, Zoltán Majó <zoltan.majo at oracle.com> wrote:
> 
> 
>> When a reference becomes unreachable (not by examining the source code but the actual state of the VM at runtime), it will never be enqueued.
> 
> I also like that wording, thank you!

BTW I am not proposing this be added in the spec.  My intent is to clarify why I think the current statement in the spec is correct.

Mandy