Get docstrings working.

jedi/evaluate/__init__.py

@@ -166,6 +166,9 @@ class Evaluator(object):
 
     @memoize_default(evaluator_is_first_arg=True)
     def eval_element(self, element):
+        if isinstance(element, iterable.AlreadyEvaluated):
+            return element
+
         debug.dbg('eval_element %s@%s', element, element.start_pos)
         if isinstance(element, (pr.Name, pr.Literal)) or pr.is_node(element, 'atom'):
             return self._eval_atom(element)