8166229: Eliminate ParNew's use of klass_or_null()

[Jon Masamitsu]

Change looks good.

Jon

On 09/18/2016 03:23 PM, Kim Barrett wrote:
> Please review this change to ParNew (the young-gen collector paired
> with CMS), eliminating it's use of klass_or_null(), instead using
> list_ptr_from_klass().
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8166229
>
> Webrev:
> http://cr.openjdk.java.net/~kbarrett/8166229/webrev.00/
>
> Testing:
> Local jtreg tests with the following additional options:
>   -XX:+UseConcMarkSweepGC
>   -XX:-UseCompressedOops
>   -XX:-ParGCUseLocalOverflow
>   -XX:+ParGCWorkQueueOverflowALot
> and temporary logging on the code path where klass_or_null was being
> used, to verify testing reached the changed code.
>