Fix bad bug in structseq slicing (NULL pointers in result).  Reported by
Jack Jansen on python-dev.
Add simple test case.
Move vereq() from test_descr to test_support (it's handy!).
diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py
index 4fd11a5..ca09ca9 100644
--- a/Lib/test/test_descr.py
+++ b/Lib/test/test_descr.py
@@ -1,12 +1,8 @@
 # Test enhancements related to descriptors and new-style classes
 
-from test_support import verify, verbose, TestFailed, TESTFN
+from test_support import verify, vereq, verbose, TestFailed, TESTFN
 from copy import deepcopy
 
-def vereq(a, b):
-    if not (a == b):
-        raise TestFailed, "%r == %r" % (a, b)
-
 def veris(a, b):
     if a is not b:
         raise TestFailed, "%r is %r" % (a, b)