[sh/jdk8u] Backport region count/region size fixes

[Zhengyu Gu]

Updated: 
http://cr.openjdk.java.net/~zgu/shenandoah/sh-region-count/webrev.01/

Thanks,

-Zhengyu

On 5/27/21 1:04 PM, Aleksey Shipilev wrote:
> On 5/27/21 6:52 PM, Zhengyu Gu wrote:
>> Ah, forgot it.
>>
>> http://cr.openjdk.java.net/~zgu/shenandoah/sh-region-count/webrev.00/
> 
> Looks fine. You can restore the assert message with err_msg.
> 
>