Attached below is a patch against 0.8.17, and three new files that
should go in src/runtime. With this, SBCL builds on OS X 10.2, and
Unicode support seems to work.
The nl_langinfo replacement is kind of gross, but it works. If
LC_CTYPE and LANG are not set, it uses utf-8. It interprets "C" as
meaning latin-1, otherwise it uses utf-8.