RFR: JDK-8224667: Shenandoah: Post-LRB cleanup

[Roman Kennke]

 We've got some leftover mentions of write-barrier in our code. We
better clean that up and change to corresponding load-reference-barrier
mentions. Also, some arraycopy code that previously named things
'READ-*' and 'WRITE-' is now more apppropriately named 'RESOLVE*' and
'EVAC*'.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8224667
Webrev:
http://cr.openjdk.java.net/~rkennke/JDK-8224667/webrev.00/

Testing: hotspot_gc_shenandoah

Ok?

Roman