Add test confirming correct handling of zope.interface.Interface in query.

python/ql/test/query-tests/Functions/general/special.py

@@ -12,4 +12,17 @@ class C(object):
         pass
 
     def __get__(self, *args):
-        pass
+        pass
+
+from zope.interface import Interface
+
+class I(Interface):
+    pass
+
+class M(I):
+
+    def __setattr__(name, value):
+        pass
+
+    def __getitem__(name):
+        pass