RFR (S): 8151322: Implement os::set_native_thread_name() on Solaris

[David Holmes]

RFE: https://bugs.openjdk.java.net/browse/JDK-8151322

Webrev: http://cr.openjdk.java.net/~dholmes/8151322/webrev/

As of Solaris 11.3 pthread_set_name_np has been implemented:

http://docs.oracle.com/cd/E53394_01/html/E54766/pthread-setname-np-3c.html#scrolltoc

https://blogs.oracle.com/observatory/entry/named_threads

So we can now implement os::set_native_thread_name using dynamic lookup 
as done on Linux. The only difference is we have 31 characters to play 
with instead of 16.

Testing: - JPRT (only 11.2 systems)
          - Manually on 11.3 - see examples in bug report

Thanks,
David