[11] RFR/RFC: Pick up 11.0.6+2 to sh/jdk11

[Roman Kennke]

11u updates project had tagged the 11.0.6+2, which includes a bunch of
outstanding changes in 11u project. Let's pick those up.

The merge was trivial.

Changeset list:
http://cr.openjdk.java.net/~rkennke/sh-jdk11-11.0.6%2b02/changesets.txt

Testing: hotspot_gc_shenandoah {fastdebug,release}

I'd push the tag shenandoah-jdk-11.0.6+2 together with this merge.

Ok?

Roman