Add unit test

test/Function/bug_os17698041.js

@@ -0,0 +1,15 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+// Should not crash with switches:
+// -off:deferparse -force:redeferral -collectgarbage -parserstatecache -useparserstatecache
+
+function test() { }
+
+test();
+CollectGarbage();
+test();
+
+console.log('pass'); 

test/Function/rlexe.xml

@@ -449,4 +449,10 @@
       <compile-flags>-force:deferparse -force:redeferral</compile-flags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>bug_os17698041.js</files>
+      <compile-flags>-off:deferparse -force:redeferral -collectgarbage -parserstatecache -useparserstatecache</compile-flags>
+    </default>
+  </test>
 </regress-exe>