RFR: JDK-8207800: always_do_update_barrier is unused

[Evgeny Mandrikov]

Hello!

Please review patch [1] for JDK-8207800 [2]. Also it needs a sponsor since
I have only author status in OpenJDK Census [3].

After this change tier1 tests pass on my machine.


With best regards,
Evgeny Mandrikov

[1] http://cr.openjdk.java.net/~godin/8207800/webrev.00/
[2] https://bugs.openjdk.java.net/browse/JDK-8207800
[3] https://openjdk.java.net/census#godin