RFC: Pick up 11.0.4+5 to sh/jdk11

[Roman Kennke]

Yes, let's do it.

Thanks,
Roman

> Upstream had published 11.0.4+5, let's pick that up to sh/jdk11. The merges were trivial, but I
> would like to give it a single pass via testing before tagging it shenandoah-jdk-11.0.4+5.
> 
> Changesets:
>   http://cr.openjdk.java.net/~shade/shenandoah/merges/jdk11-11.0.4%2b5/changesets.txt
> 
> Testing: hotspot_gc_shenandoah {fastdebug|release}
>