Regexps vs. locale

This came up on irc:

postgres=# show lc_ctype; lc_ctype   
-------------fr_FR.UTF-8

postgres=# show server_encoding;server_encoding 
-----------------UTF8
(1 row)

postgres=# select E'\303\201' ILIKE  E'\303\241';?column? 
----------t
(1 row)

postgres=# select E'\303\201' ~*  E'\303\241';?column? 
----------f
(1 row)

Obviously, this happens because the locale support functions in
backend/regex/regc_locale.c are (presumably intentionally) crippled so
as not to support non-ascii chars, despite all the code there using
wide chars for everything otherwise.

Why is this? It does not appear to be a documented restriction.

-- 
Andrew (irc:RhodiumToad)