RFR: 8238599: Refactor and simplify implAddOpensToAllUnnamed

[Claes Redestad]

On 2020-02-06 18:52, Alan Bateman wrote:
>> Webrev: http://cr.openjdk.java.net/~redestad/8238599/open.00/
> This looks good, just a minor nit that declaring emptySet without any 
> context looks a bit strange. If you move it to below the comment "open 
> specific packages in the system modules" then it will be clearer that 
> it's used in this part of the method.

Thanks, will fix before push.

/Claes