RFR: 8142402: G1 should not redirty cards in free regions

[Erik Helin]

All,

I just rebased the patch and discovered that heap_region_containing_raw
has been renamed to heap_region_containing. Please see new webrevs:

- incremental:
http://cr.openjdk.java.net/~ehelin/8142402/webrev.00-01/
- full:
http://cr.openjdk.java.net/~ehelin/8142402/webrev.01/

Thanks,
Erik

On 2015-11-10, Erik Helin wrote:
> Hi all,
> 
> this patch ensures that G1 does not redirty cards for regions that are
> free. This not a problem for product builds, but it causes the card
> verification code to fail in debug builds, which is annoying.
> 
> Enhancement:
> https://bugs.openjdk.java.net/browse/JDK-8142402
> 
> Webrev:
> http://cr.openjdk.java.net/~ehelin/8142402/webrev.00/
> 
> Testing:
> JPRT
> 
> Thanks,
> Erik