RFR: Out-of-TLAB allocation should overwrite stale copies

[Zhengyu Gu]

Yes! I think this is the case. Looks good to me.

Thanks,

-Zhengyu

On 06/15/2017 06:18 AM, Aleksey Shipilev wrote:
> One of the failures we were chasing for a while now was apparently caused by the
> trouble with out-of-TLAB allocation during evacuation. Then, we could leave the
> "alive" object with garbled ptrs, on which we'd then crash during subsequent
> pauses. See more details in the patch comments.
>
> Fix:
>   http://cr.openjdk.java.net/~shade/shenandoah/evac-non-tlab/webrev.02
>
> I also cleaned up evacuate_object while we are at it.
>
> Testing: hotspot_gc_shenandoah (includes tests that were failing before)
>
> Thanks,
> -Aleksey
>