RFR(XS): 8209686: cleanup arguments to PhaseIdealLoop() constructor

[Per Liden]

Hi Roland,

On 08/22/2018 10:35 AM, Roland Westrelin wrote:
> 
> Hi Per,
> 
>> Do we really want to encode ZGC into LoopOptsZgcLastRound? Shouldn't it
>> be just LoopOptsLastRound? I'm thinking this has little to do with ZGC,
>> except that ZGC happens to be the only user of it at the moment.
> 
> Ok. I'll make that change. Thanks for looking at this.

Ok, thanks. Change looked good otherwise.

Btw, I just learned that Nils' next iteration of the ZGC load barriers 
will remove the need for the LastRound state, so expect it to go away in 
the future.

cheers,
Per

> 
> Roland.
>