RFR (S): Merge strict oop operations for new upstream code

[Aleksey Shipilev]

Hi,

This is another post-merge fixup:
  http://cr.openjdk.java.net/~shade/shenandoah/merge9-strictoops/webrev.01/

Current head fails jcstress with -XX:+VerifyStrictOopOperations because of this.

Testing: hotspot_gc_shenandoah, jcstress -m quick

Thanks,
-Aleksey