Try to get ScenarioXGC passing

Author: slozier

Src/IronPythonTest/Stress/Engine.cs

@@ -41,6 +41,8 @@ private static long GetTotalMemory() {
 #if FEATURE_REFEMIT
         [Test]
         public void ScenarioXGC() {
+            Assert.AreEqual(1, 1); // prevents nunit from counting towards memory usage
+
             long initialMemory = GetTotalMemory();
 
             // Create multiple scopes: