RFR: TestFullGCCount still not quite right

[Zhengyu Gu]

By default, ExplicitGCInvokesConcurrent flag is true for Shenandoah, 
therefore, we need to filter it out when the flag is not specified.

diff -r 8b751872d64a test/hotspot/jtreg/gc/TestFullGCCount.java
--- a/test/hotspot/jtreg/gc/TestFullGCCount.java        Fri Nov 30 
16:04:44 2018 -0500
+++ b/test/hotspot/jtreg/gc/TestFullGCCount.java        Fri Nov 30 
16:10:37 2018 -0500
@@ -26,7 +26,7 @@
   * @bug 7072527
   * @summary CMS: JMM GC counters overcount in some cases
   * @requires !(vm.gc == "ConcMarkSweep" & 
vm.opt.ExplicitGCInvokesConcurrent == true)
- * @requires !(vm.gc == "Shenandoah"    & 
vm.opt.ExplicitGCInvokesConcurrent == true)
+ * @requires !(vm.gc == "Shenandoah"    & 
(vm.opt.ExplicitGCInvokesConcurrent == true | 
vm.opt.ExplicitGCInvokesConcurrent == null))
   * @modules java.management
   * @run main/othervm -Xlog:gc TestFullGCCount
   */


Test:
   make CONF=linux-x86_64-server-fastdebug run-test 
TEST=gc/TestFullGCCount.java 
JTREG="VM_OPTIONS=-XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC"

Should not run.

and

make CONF=linux-x86_64-server-fastdebug run-test 
TEST=gc/TestFullGCCount.java 
JTREG="VM_OPTIONS=-XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC 
-XX:-ExplicitGCInvokesConcurrent"

Should run.

Thanks,

-Zhengyu