RFC: [9] Bulk backports to sh/jdk9

[Aleksey Shipilev]

http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk9-20171109/webrev.01/

Changes include:

rev 13734 : [backport] Forcefully update counters when GC cycle is running
rev 13735 : [backport] Can not dedup string inside write barrier
rev 13736 : [backport] Add new pinned/cset region state for evac-failure-path

Testing: hotspot_gc_shenandoah {fastdebug|release}

Thanks,
-Aleksey