RFR (round 4), JDK-8214259: Implementation: JEP 189: Shenandoah: A Low-Pause Garbage Collector

[Roman Kennke]

Hi Magnus,

>> I got reviews for shared-build, but an earlier version, so maybe makes
>> sense to look over this again. Erik J, Magnus?
> 
> Build changes look good. 

Thanks, Magnus!

Roman