[11] 2020-03-03, Bulk backports to sh/jdk11

[Roman Kennke]

Hi Aleksey,

Looks good to me.

Thank you!
Roman

> https://cr.openjdk.java.net/~shade/shenandoah/backports/jdk11-20200303/webrev.01/
> 
> This backports the following improvements to sh/jdk11:
>  [backport] 8238851: Shenandoah: C1: Resolve into registers of correct type
>  [backport] 8237837: Shenandoah: assert(mem == __null) failed: only one safepoint
>  [backport] 8240215: Shenandoah: remove ShenandoahAllocationTrace
>  [backport] 8240216: Shenandoah: remove ShenandoahTerminationTrace
>  [backport] 8240217: Shenandoah: remove ShenandoahEvacAssist
> 
> All apply cleanly, except 8240217, where ShenandoahEvacAssist has different context. This is not a
> problem, since the entire block is going away, so I purged it by hand.
> 
> Please review carefully.
> 
> Testing: hotspot_gc_shenandoah {fastdebug,release}
>