RFR: Region (byte|word) shifts as the replacement for divisions

[Roman Kennke]

Am 31.08.2017 um 09:15 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/regionsizes-shift/webrev.01/
> 
> The actual performance fix is in SHR::required_regions(), where we have replaced the integer
> division on humongous allocation path with the shift. Other changes are done for consistency.
> 
> Testing: hotspot_gc_shenandoah
> 
> Thanks,
> -Aleksey
> 
Ok