Issue #16688: Fix backreferences did make case-insensitive regex fail on non-ASCII...

Patch by Matthew Barnett.

diff --cc Misc/ACKS
Simple merge

diff --cc Misc/NEWS
index d4aa0dda7605f70e3f930ca818aa7635b43be3fb,c2bfa00148e8c7a2097fffac9b1d06458bc0f5ff..702a30e42ba5a0d5a81fea4ec06ba4b08e2cab3a
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -200,8 -124,9 +200,11 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #16688: Fix backreferences did make case-insensitive regex fail on
+   non-ASCII strings. Patch by Matthew Barnett.
+ 
 +- Issue #16486: Make aifc files work with 'with' as context managers.
 +
  - Issue #16485: Fix file descriptor not being closed if file header patching
    fails on closing of aifc file.
  

diff --cc Modules/_sre.c
Simple merge