Break the cycles after testing cmp() on cyclic objects.

Lib/test/test_b1.py

@@ -72,6 +72,8 @@ if cmp(a, b) != 0: raise TestFailed, "cmp(%s, %s)" % (a, b)
 if cmp(b, c) != 0: raise TestFailed, "cmp(%s, %s)" % (b, c)
 if cmp(c, a) != 0: raise TestFailed, "cmp(%s, %s)" % (c, a)
 if cmp(a, c) != 0: raise TestFailed, "cmp(%s, %s)" % (a, c)
+# okay, now break the cycles
+a.pop(); b.pop(); c.pop()
 
 print 'coerce'
 if fcmp(coerce(1, 1.1), (1.0, 1.1)): raise TestFailed, 'coerce(1, 1.1)'