RFR: AArch64: Don't generate CAS barrier when -XX:-ShenandoahCASBarrier

[Aleksey Shipilev]

On 09/10/2018 09:35 PM, Roman Kennke wrote:
> Some tests are failing in aarch64 because we generate CAS barrier even
> when passing -XX:-ShenandoahCASBarrier in ShBSA:
> 
> http://cr.openjdk.java.net/~rkennke/aarch64-fixcas/webrev.00/

Looks good.

-Aleksey