RFR: Optimize fwdptr region handling in ShenandoahVerifyOopClosure::verify_oop

[Roman Kennke]

Am 05.12.2017 um 17:01 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/verifier-perf-fhr/webrev.01/
> 
> This does the obvious optimization for fwdptr region handling: should not call
> heap_region_containing 4x times, when we can call it 1x time for non-forwarded objects.
> 
> Testing: hotspot_gc_shenandoah
> 
> Thanks,
> -Aleksey
> 
Ok