RFR: Enable biased locking for Shenandoah by default

[Roman Kennke]

Am 20.11.2017 um 13:01 schrieb Aleksey Shipilev:
> On 11/20/2017 12:41 PM, Roman Kennke wrote:
>> Any idea if/how this affects latency?
> Few thoughts here:
>
>   *) Biased locking is inherently orthogonal to GC code, and is not visible even in gross GC pauses.
> Therefore, we have no observable improvements, as far as GC logging is concerned. (This is different
> for loop strip mining, that does improve gross pause times);
>
>   *) With the throughput hit we observe, it makes less sense to focus on orthogonal VM pauses.
>
> Thanks,
> -Aleksey
>
>
Yes.

Plus we don't really want to change flag defaults if we can avoid it. Ok 
from me.

Roman