patch: utf8_to_unicode (trivial)

In src/include/mb/pg_wchar.h , there is a function unicode_to_utf8 ,
but no corresponding utf8_to_unicode . However, there is a static
function called utf2ucs that does what utf8_to_unicode would do.

I'd like this function to be available because the JSON code needs to
convert UTF-8 to and from Unicode codepoints, and I'm currently using
a separate UTF-8 to codepoint function for that.

This patch renames utf2ucs to utf8_to_unicode and makes it public. It
also fixes the version of utf2ucs in src/bin/psql/mbprint.c so that
it's equivalent to the one in wchar.c .

This is a patch against CVS HEAD for application. It compiles and
tests successfully.

Comments? Thanks,

Joey Adams