[14] RFR (S) 8242365: Shenandoah: use uint16_t instead of jushort for liveness cache

[Roman Kennke]

It looks good, thank you!

Roman


> Original fix:
>   https://bugs.openjdk.java.net/browse/JDK-8242365
>   https://hg.openjdk.java.net/jdk/jdk/rev/9e3539baac38
> 
> The patch does not apply cleanly to 14u due to changed context. I had to change some jushort* to
> ShenandoahLiveData* by hand. 14u webrev:
>   https://cr.openjdk.java.net/~shade/8242365/webrev.14u.01/
> 
> Testing: hotspot_gc_shenandoah
>