RFC: Pick up jdk-10.0.1 to sh/jdk10

[Aleksey Shipilev]

Upstream had published changes for jdk-10.0.1, let's pick them up to sh/jdk10.
Most of the changes are jdk, and pose no problems for us.

hotspot/ changes look safe to me, added a single oopDesc::equals in new RP paths there:
  http://cr.openjdk.java.net/~shade/shenandoah/merge-jdk10-2018-04-19/hotspot-new.patch

Testing: hotspot_gc_shenandoah {fastdebug|release}

Thanks,
-Aleksey