RFR: 8225779: Remove unused CollectedHeap::cell_header_size()

[Per Liden]

Thanks for reviewing, Aleksey!

/Per

On 6/17/19 2:55 PM, Aleksey Shipilev wrote:
> On 6/17/19 2:51 PM, Per Liden wrote:
>> Here's an updated webrev, which just removes the cell_header_size() and its uses, but otherwise
>> keeps the code as is.
>>
>> http://cr.openjdk.java.net/~pliden/8225779/webrev.1
> 
> Still looks good.
> 
> -Aleksey
>