Python 3.2 rejects characters outside the range U+0000-U+10ffff in
some operations, but not everywhere. I fixed Python 3.3 to be more
strict and always reject characters outside this range. I noticed the
Solaris issue with mbstowcs() on locale encodings different than
UTF-8: #13441. I asked if it's more important to be strict on Unicode,
or if we need to handle the wcsxfrm() issue on python-dev:
http://mail.python.org/pipermail/python-dev/2011-December/114759.html

Stefan Krah answered: "Yes, if the cause is a broken mbstowcs() that
sounds good."
http://mail.python.org/pipermail/python-dev/2011-December/114781.html

I asked for help on OpenIndiana IRC channel, but nobody had a locale
encoding different than UTF-8. I didn't have access to a Solaris box,
so I chose to skip failing tests on Solaris.

My commit 2a2d0872d993 (and 7ffe3d304487) skips many locales to
workaround this issue in test__locale.