Request for Approval: Backport of 8147611: G1 - Missing memory barrier in start_cset_region_for_worker

[Yangfei (Felix)]

>>     Bug: https://bugs.openjdk.java.net/browse/JDK-8147611
>> 
>>     JDK9 Changeset: 
>> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/8fcd5cba7938
>> 
>> 
>> 
>>     The code change is trivial and should be easy for it to be applied to the jdk8u master repo.
>> 

> There doesn't seem to be a patch here for review.
> I applied the 11u version and the hunk had to be manually applied instead because of whitespace differences.
> I've pushed it now, but in future, cases like this should be posted for review before seeking approval. Skipping the review process is only applicable when the patch applies cleanly, after file paths are adjusted.
> The fix request comment on the bug should detail whether it applies cleanly or not, and link to a review thread if not.

Yes, that's the correct backport process.  I noticed that process later on and I was following it for my later backport requests.  
Thank you for your effort.  

> Also note that I gave approval for this on 2019-06-12, but it has never been committed in the subsequent two and half months.  

I also saw that approval.  I was expecting someone else to help push this `one-line` change as I am not a jdk8u committer.  

Felix