Stop producing or using OverflowWarning.  PEP 237 thought this would
happen in 2.3, but nobody noticed it still was getting generated (the
warning was disabled by default).  OverflowWarning and
PyExc_OverflowWarning should be removed for 2.5, and left notes all over
saying so.
diff --git a/Misc/NEWS b/Misc/NEWS
index bc77b7d..56c687f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,12 @@
 Core and builtins
 -----------------
 
+- OverflowWarning is no longer generated.  PEP 237 scheduled this to
+  occur in Python 2.3, but since OverflowWarning was disabled by default,
+  nobody realized it was still being generated.  On the chance that user
+  code is still using them, the Python builtin OverflowWarning, and
+  corresponding C API PyExc_OverflowWarning, will exist until Python 2.5.
+
 - Py_InitializeEx has been added.
 
 - Fix the order of application of decorators.  The proper order is bottom-up;