Issue #16564: Fixed a performance regression relative to Python 3.1 in the

caching of compiled regular expressions.

diff --cc Misc/NEWS
index 893c592e3d534085156ce7eb52cc1d6f87ea01c9,fa689eae0aed02c55b99486bf60b24441c680f12..e69e03c9b753a2eae41709501e1144207fb75f4c
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -283,15 -193,11 +283,18 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #16564: Fixed a performance regression relative to Python 3.1 in the
+   caching of compiled regular expressions.
+ 
 +- Added missing FeedParser and BytesFeedParser to email.parser.__all__.
 +
  - Issue #17431: Fix missing import of BytesFeedParser in email.parser.
  
 +- Issue #12921: http.server's send_error takes an explain argument to send more
 +  information in response. Patch contributed by Karl.
 +
 +- Issue #17414: Add timeit, repeat, and default_timer to timeit.__all__.
 +
  - Issue #1285086: Get rid of the refcounting hack and speed up
    urllib.parse.unquote() and urllib.parse.unquote_to_bytes().