Work around a bug in Tamarin. Sorry for the ugly. Hopefully it's temporary.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5068 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/as/com/threerings/presents/dobj/DEvent.as

@@ -32,6 +32,10 @@ public /* abstract */ class DEvent
 {
     public function DEvent (targetOid :int = 0)
     {
+        // TODO: Remove when https://bugzilla.mozilla.org/show_bug.cgi?id=433103 is fixed
+        if (UNSET_OLD_ENTRY == null) {
+            UNSET_OLD_ENTRY = new DummyEntry();
+        }
         _toid = targetOid;
     }
 
@@ -112,6 +116,6 @@ public /* abstract */ class DEvent
     /** The oid of the object that is the target of this event. */
     protected var _toid :int;
 
-    protected static const UNSET_OLD_ENTRY :DSet_Entry = new DummyEntry();
+    protected static var UNSET_OLD_ENTRY :DSet_Entry;
 }
 }