RFR(S): 8210513: Obsolete SyncFlags

Fri Sep 7 20:48:48 UTC 2018

Please review this change which obsoletes the SyncFlags flag.

Bug: https://bugs.openjdk.java.net/browse/JDK-8210513 <https://bugs.openjdk.java.net/browse/JDK-8210513>
Webrev: http://cr.openjdk.java.net/~mikael/webrevs/8210513/webrev.00/open/webrev/ <http://cr.openjdk.java.net/~mikael/webrevs/8210513/webrev.00/open/webrev/>

* Background (from bug)

The experimental SyncFlags flag can in theory be used to tune how the synchronization primitives behave. The flag was convenient when the various implementations were compared a long time ago. 

In practice the only implementation that is used and tested today is the default one. The SyncFlags flag no longer serves the purpose it used to, and is "Unsafe, Unstable" (the documentation of the flag says so explicitly). It should be obsoleted and later removed.

Testing: I’m running the normal tier1 testing (still in progress).

Cheers,
Mikael