Fixed an issue with ArrayInstances that were using name lookups, which it doesn't have.

jedi/evaluate/compiled/fake/builtins.pym

@@ -156,7 +156,7 @@ class set():
             yield i
 
     def pop(self):
-        return self.__iterable.pop()
+        return list(self.__iterable)[-1]
 
     def copy(self):
         return self