[8] RFC: Pick up aarch64-shenandoah-jdk8u242-b08 to sh/jdk8

[Roman Kennke]

Yes, go!

Thanks,
Roman


> Hi,
> 
> Let's pick up the latest CPU update to sh/jdk8. The merge/update is trivial.
> 
> Testing: hotspot_gc_shenandoah {fastdebug,release}
>