RFR: 8198432: Remove Thread extension point

[Erik Helin]

On 02/26/2018 11:54 AM, Stefan Johansson wrote:
> Hi,
> 
> Please review this small change to remove a now unused extension point.
> 
> Links
> JBS: https://bugs.openjdk.java.net/browse/JDK-8198432
> Webrev: http://cr.openjdk.java.net/~sjohanss/8198432/00/

Looks good, Reviewed.

Thanks,
Erik

> Summary
> The Thread class extension support made it possible to add extra data to 
> it. This is no longer needed since the internal code using it has been 
> removed.
> 
> Testing
> Built locally and through Mach5.
> 
> Thanks,
> Stefan