RFR: Improve inlining of the update-refs closure. Implement update-refs verification.

[Aleksey Shipilev]

On 03/30/2017 01:48 PM, Roman Kennke wrote:
> This makes the update-refs closure inline better.
> 
> It's done by adding a templated marked_object_oop_iterate() method that
> uses a templated object->oop closure and call marked_object_iterate()
> with that. The effect is that the call to obj->oop_iterate() can use a
> non-virtual inlined call to the actual OopClosure.
> 
> I've also added a little verification routine that checks that no marked
> object points to any to-space object after updating references.
> 
> http://cr.openjdk.java.net/~rkennke/update-refs-inlining/webrev.01/

Looks fine.

-Aleksey