RFR (S) 8232702: Shenandoah: gc/shenandoah/TestVerifyJCStress.java uses non-existent -XX:+VerifyObjectEquals

[Aleksey Shipilev]

Testbug:
  https://bugs.openjdk.java.net/browse/JDK-8232702

Fix:
  https://cr.openjdk.java.net/~shade/8232702/webrev.01/

This is the left-over from the days when ShenandoahVerifyObjectEquals was just VerifyObjectEquals.
It was removed by JDK-8231946. This test never noticed it, because it ignored unrecognized VM
options wholesale, but should really only do it for the ShVerifyOptoBarriers.

Testing: affected test on Linux x86_64 {release, fastdebug, slowdebug}

-- 
Thanks,
-Aleksey