RFR(S): 8222518: Remove unnecessary caching of Parker object in java.lang.Thread

[Alan Bateman]

On 26/04/2019 06:32, David Holmes wrote:
> I pushed this today based on Dan and Robbin's reviews, but realized 
> just after the act that I should have waited for any feedback from 
> core-libs - apologies about that. If there are concerns I will roll it 
> back.
I don't think there are any concerns, it is of course very welcome to 
remove a field from Thread.

-Alan