RFR: JDK-8202884: SA: Attach/detach might fail on Linux if debugee application create/destroy threads during attaching

[Jini George]

>
>>
>> Going forward, we should remove the libpthread_db dependency for the
>> threads discovery and only depend on /proc/<pid>/task/<lwpid>s for this
>> (https://bugs.openjdk.java.net/browse/JDK-8181313).
> 
> It's great news!
> I will help you :-)
> 

Sure -- and thank you for the review!

-Jini.