use other thread instead of EDT as an argument to notifyThreadBusy to avoid tests crash

platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java

@@ -221,7 +221,11 @@ public class ApplicationImpl extends PlatformComponentManagerImpl implements App
     gatherStatistics = LOG.isDebugEnabled() || isUnitTestMode() || isInternal();
 
     Thread edt = UIUtil.invokeAndWaitIfNeeded(() -> {
-      AWTAutoShutdown.getInstance().notifyThreadBusy(Thread.currentThread()); // needed for EDT not to exit suddenly
+      // instantiate AppDelayQueue which starts "Periodic task thread" which we'll mark busy to prevent this EDT to die
+      // that thread was chosen because we know for sure it's running
+      AppScheduledExecutorService service = (AppScheduledExecutorService)AppExecutorUtil.getAppScheduledExecutorService();
+      Thread thread = service.getPeriodicTasksThread();
+      AWTAutoShutdown.getInstance().notifyThreadBusy(thread); // needed for EDT not to exit suddenly
       return Thread.currentThread();
     });
     myLock = new ReadMostlyRWLock(edt);

platform/util/src/com/intellij/util/concurrency/AppDelayQueue.java

@@ -84,4 +84,8 @@ class AppDelayQueue extends DelayQueue<SchedulingWrapper.MyScheduledFutureTask>
       throw new RuntimeException(e);
     }
   }
+
+  Thread getThread() {
+    return scheduledToPooledTransferer;
+  }
 }

platform/util/src/com/intellij/util/concurrency/AppScheduledExecutorService.java

@@ -208,4 +208,8 @@ public class AppScheduledExecutorService extends SchedulingWrapper {
       error();
     }
   }
+  @NotNull
+  public Thread getPeriodicTasksThread() {
+    return delayQueue.getThread();
+  }
 }