RFR (S) 8241844: Shenandoah: rename ShenandoahHeapRegion::region_number

[Roman Kennke]

>>> RFR:
>>>   https://bugs.openjdk.java.net/browse/JDK-8241844
>>>
>>> ShenandoahHeapRegion::region_number is too verbose of the name, plus most of the code already treats
>>> it as "index" in the local variable. Can rename it for consistency. I am not sure whether it should
>>> be "idx" or "index".
>>>
>>> Candidate fix:
>>>   https://cr.openjdk.java.net/~shade/8241844/webrev.01/
>>>
>>> Testing: hotspot_gc_shenandoah
>>
>> I'd prefer index, but if it's too much trouble to rename it, then leave
>> it as idx.
> 
> No bother until this is committed. Renamed to "index" like this:
>   https://cr.openjdk.java.net/~shade/8241844/webrev.01/
> 
> Better?

It's:
https://cr.openjdk.java.net/~shade/8241844/webrev.02/

Yes, this looks better to me.
Thank you!

Roman