RFR: Upstream merge to jdk-12+21

[Aleksey Shipilev]

On 11/22/18 4:43 PM, Roman Kennke wrote:
> jdk-12+21 arrived, let's merge up to it:
> 
> http://cr.openjdk.java.net/~rkennke/upstream-jdk12-merge-2018-11-22/outgoing.txt

Upstream is broken with JDK-8213419. We can pick up this merge, but we should really consider doing
another merge/cherry-pick soon.

Thanks,
-Aleksey