RFR(T) 8229231: Shenandoah: Non-PCH builds failed after JDK-8224932

[Roman Kennke]

Looks good! Thanks!

Roman


> Please review this trivial patch that fixes breakage of Shenandoah/jdk
> Non-PCH builds.
> 
> I could not reproduce on jdk/jdk, so let's push to shenandoah/jdk.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8229231
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8229231/webrev.00/
> 
> Test:
>   Non-PCH build on Windows.
> 
> Thanks,
> 
> -Zhengyu