[11] 2020-02-27, Bulk backports to sh/jdk11

[Roman Kennke]

Hi Aleksey,

This looks good. Thank you!

Roman

> https://cr.openjdk.java.net/~shade/shenandoah/backports/jdk11-20200227/webrev.01/
> 
> This backports another batch of simple changes:
> 
>  [backport] 8238385: CTW: C2 (Shenandoah) compilation fails with "Range check dependent CastII node
> was not removed"
>  [backport] 8240076: Shenandoah: pacer should cover reset and preclean phases
>  [backport] 8240069: Shenandoah: turn more flags diagnostic
>  [backport] 8239904: Shenandoah: accumulated penalties should not be over 100% of capacity
>  [backport] 8239868: Shenandoah: ditch C2 node limit adjustments
>  [backport] 8240070: Shenandoah: remove obsolete ShenandoahCommonGCStateLoads
> 
> Testing: hotspot_gc_shenandoah {fastdebug,release}
>