RFR: sh/jdk8 backport of JDK-8217016: Shenandoah: Streamline generation of CAS barriers

[Aleksey Shipilev]

On 5/14/19 9:27 AM, Roman Kennke wrote:
> http://cr.openjdk.java.net/~rkennke/backport-jdk8-2019-05-14/webrev.00/

*) Closing parenthesis is missing here in MacroAssembler::cmpxchg_oop_shenandoah:

2260   // Check if rb(expected)==rb(tmp1

Otherwise good.

-Aleksey