RFR 8217342: Build failed with excluding JFR

[Zhengyu Gu]

Thanks for reviewing, Aleksey and Per.

>>
>> I think zBarrierSet.hpp includes gc/shared/barrierSet.hpp already, so 
>> no need for it in
>> zBarrierSetC2.cpp?
> 
> Agree, only including zBarrierSet.hpp should be enough. Other than that, 
> the ZGC parts look good.

Verified.

Updated webrev: http://cr.openjdk.java.net/~zgu/JDK-8217342/webrev.01/

Thanks,

-Zhengyu

> 
> /Per