8288000: compiler/loopopts/TestOverUnrolling2.java fails with release VMs

Backport-of: d959c22a9574359e2d5134ac8365e8a9df4f7cef

Author: caojoshua

test/hotspot/jtreg/compiler/loopopts/TestOverUnrolling2.java

@@ -26,8 +26,8 @@
  * @bug 8286625
  * @key stress
  * @summary C2 fails with assert(!n->is_Store() && !n->is_LoadStore()) failed: no node with a side effect
- * @run main/othervm -XX:-BackgroundCompilation -XX:+StressIGVN -XX:StressSeed=4232417824 TestOverUnrolling2
- * @run main/othervm -XX:-BackgroundCompilation -XX:+StressIGVN TestOverUnrolling2
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-BackgroundCompilation -XX:+StressIGVN -XX:StressSeed=4232417824 TestOverUnrolling2
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:-BackgroundCompilation -XX:+StressIGVN TestOverUnrolling2
  */
 
 public class TestOverUnrolling2 {