8308429: jvmti/StopThread/stopthrd007 failed with "NoClassDefFoundErr…

…or: Could not initialize class jdk.internal.misc.VirtualThreads"

Reviewed-by: dholmes, sspitsyn

test/hotspot/jtreg/vmTestbase/nsk/jvmti/StopThread/stopthrd007.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2023, 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
@@ -28,6 +28,8 @@
 import nsk.share.*;
 import nsk.share.jvmti.*;
 
+import java.util.concurrent.locks.LockSupport;
+
 public class stopthrd007 extends DebugeeClass {
 
     // run test from command line
@@ -66,6 +68,11 @@ public int runIt(String argv[], PrintStream out) {
         log = new Log(out, argHandler);
         timeout = argHandler.getWaitTime() * 60 * 1000;
 
+        // Unpark virtual threads to load jdk.internal.misc.VirtualThreads
+        // and avoid NoClassDefFoundError if ThreadDeath is happen during unlock.
+        Thread vt = Thread.startVirtualThread(LockSupport::park);
+        LockSupport.unpark(vt);
+
         log.display("Debugee started");
 
         startingBarrier = new Wicket(3);