Fix buildbot issues due to _ctypes failing to compile in 3.1.

Recorded rollback of revisions 83837,83841 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k
diff --git a/setup.py b/setup.py
index 3cfd275..332033d 100644
--- a/setup.py
+++ b/setup.py
@@ -1636,7 +1636,8 @@
                    '_ctypes/callbacks.c',
                    '_ctypes/callproc.c',
                    '_ctypes/stgdict.c',
-                   '_ctypes/cfield.c']
+                   '_ctypes/cfield.c',
+                   '_ctypes/malloc_closure.c']
         depends = ['_ctypes/ctypes.h']
 
         if sys.platform == 'darwin':