8280553: resourcehogs/serviceability/sa/TestHeapDumpForLargeArray.java can fail if GC occurs

Reviewed-by: alanb, amenkov

Author: plummercj

test/hotspot/jtreg/resourcehogs/serviceability/sa/LingeredAppWithLargeArray.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,9 +23,12 @@
 
 import jdk.test.lib.apps.LingeredApp;
 
+import java.lang.ref.Reference;
+
 public class LingeredAppWithLargeArray extends LingeredApp {
     public static void main(String args[]) {
         int[] hugeArray = new int[Integer.MAX_VALUE/2];
         LingeredApp.main(args);
+        Reference.reachabilityFence(hugeArray);
     }
  }