#16918: merge with 3.3.

diff --cc Lib/test/test_codecs.py
Simple merge

diff --cc Misc/NEWS
index bf6ab72c86c9ced5f2445556eba99d98c17dcfc6,c5e987187187543f59d46578a4d9174220fa2c79..bb46fe1ba5b2d5e69a34d3b5cce099cbc4159993
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -618,8 -421,9 +618,11 @@@ Extension Module
  Tests
  -----
  
 +- Issue #16836: Enable IPv6 support even if IPv6 is disabled on the build host.
 +
+ - Issue #16918: test_codecs now works with unittest test discovery.
+   Patch by Zachary Ware.
+ 
  - Issue #16919: test_crypt now works with unittest test discovery.
    Patch by Zachary Ware.