[11u] RFR: Fix non-Shenandoah builds

[Aleksey Shipilev]

On 7/19/19 7:42 PM, Roman Kennke wrote:
>> Well, I liked the first fix because it matched what jdk/jdk was doing.
> 
> Yes, I understand this, but in jdk/jdk Shenandoah is included in
> mainline, while in JDK11u we're not, and we want to make it obvious that
> we're good.
> 
> The proposed change below looks good.
Okay then, pushed that.

-- 
Thanks,
-Aleksey