RFR: 8189088: Add intrusive doubly-linked list utility

[Kim Barrett]

> On Oct 10, 2017, at 4:47 AM, David Holmes <david.holmes at oracle.com> wrote:
> 
> Hi Kim,
> 
> I get the gist of this but am not going to pretend I can follow all the details. :)
> 
> So what actually gets expanded into the target type to support this. Is it just a next/prev pointer or is there additional infrastructure needed?

The target type gets a next/prev pair of pointers, plus a debug-only pointer to the currently containing list to support various assertions.
Those are all packaged in the IntrusiveListLink class.  Replicated for each simultaneous list an object may need to be in.