RFR: Fix Shenandoah Windows build.

[Roman Kennke]

Am 27.03.2018 um 22:06 schrieb Zhengyu Gu:
> Fix Windows build.
> 
> Webrev:
> http://cr.openjdk.java.net/~zgu/shenandoah/sh-windows-build/webrev.00/
> 
> Thanks,
> 
> -Zhengyu
> 
> 

Ok :-)