[8] 2020-03-05, Bulk backports to sh/jdk8

[Roman Kennke]

Ok, looks good. THank you!

Roman


> https://cr.openjdk.java.net/~shade/shenandoah/backports/jdk8u-20200305/webrev.01/
> 
> This is hopefully the last batch of backports for April release:
>   [backport] 8240216: Shenandoah: remove ShenandoahTerminationTrace
>   [backport] 8240217: Shenandoah: remove ShenandoahEvacAssist
>   [backport] 8240534: Shenandoah: ditch debug safepoint timeout adjustment
> 
> Testing: hotspot_gc_shenandoah {fastdebug,release}
>