RFR Shenandoah: Fix compilation errors after jdk-14+17+ merge

[Roman Kennke]

Yes. Thanks!

Roman


> Upstream changed method signature.
> 
> Webrev:
> http://cr.openjdk.java.net/~zgu/shenandoah/fix_comp_errors/webrev.00/
> 
> Test:
>   fastdebug and release build on Linux.
> 
> 
> Thanks,
> 
> -Zhengyu
>