RFR: 8216258: Make FreeIdSet semaphore-based

[Kim Barrett]

> On Jan 24, 2019, at 12:32 PM, sangheon.kim at oracle.com wrote:
> 
> Hi Kim,
> 
> On 1/8/19 5:25 PM, Kim Barrett wrote:
>> New webrevs:
>> full: http://cr.openjdk.java.net/~kbarrett/8216258/open.01/
>> incr: http://cr.openjdk.java.net/~kbarrett/8216258/open.01.inc/
> Webrev.01 looks very nice.
> Sorry for the late review.
> 
> Thanks,
> Sangheon

Thanks.