the latter is both for ABI purposes, and to facilitate eventually
adding LC_TIME support. it's also nice to eliminate an extra source
file.

this seems to have been a simple copy-and-paste error from the code
for converting from legacy codepages.

to deal with the fact that the public headers may be used with pre-c99
compilers, __restrict is used in place of restrict, and defined
appropriately for any supported compiler. we also avoid the form
[restrict] since older versions of gcc rejected it due to a bug in the
original c99 standard, and instead use the form *restrict.

posix has resolved to add this usage; for now, we just avoid writing
anything to the new locale object since it's not used anyway.

dynamic-allocation of the structure is not valid; it can crash an
application if malloc fails. since localeconv is not specified to have
failure conditions, the object needs to have static storage duration.

need to review whether all the values are right or not still..

apparently this was never tested before.

these are mostly untested and adapted directly from corresponding byte
string functions and similar.

this should be everything except for some functions where the non-_l
version isn't even implemented yet (mainly some non-ISO-C wcs*
functions).

also support (and restrict to subsets) older chinese sets, and
explicitly refuse to convert to cjk (since there's no code for it yet)

this broke most uses of iconv in real-world programs, especially
glib's iconv wrappers.

sadly the C language does not specify any such implicit conversion, so
this is not a matter of just fixing warnings (as gcc treats it) but
actual errors. i would like to revisit a number of these changes and
possibly revise the types used to reduce the number of casts required.