Issue #16688: Fix backreferences did make case-insensitive regex fail on non-ASCII strings.
Patch by Matthew Barnett.
diff --git a/Misc/ACKS b/Misc/ACKS
index af9aa06..c947a45 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -70,6 +70,7 @@
 Nick Barnes
 Quentin Barnes
 David Barnett
+Matthew Barnett
 Richard Barran
 Cesar Eduardo Barros
 Des Barry