RFR: Improve/trim register saving/restoring around WB slowpath call in stub

[Aleksey Shipilev]

On 11/21/18 12:56 PM, Roman Kennke wrote:
>>> http://cr.openjdk.java.net/~rkennke/improve-wb-stub/webrev.00/
>>
>> Can you rebase it to current Shenandoah, please?
> 
> It is already based on current Shenandoah.

I meant, please rebase the patch against current sh/jdk, which now includes the "redo" of WB change.

-Aleksey