Based on kbless basic unicode support patchset from msysgit, Credits for the initial work belongs to him.
Rearranged some of the new api headers because of build problems otherwise.
Changed newlibs local.h to not include wchar.h because its not imported correctly that early in the build and causes errors
with mbstate_t not being defined properly. Moved a local copy of the wchar.h contents to local.h instead.
Added stdint.h and inttypes.h from cygwin 1.5 and fixed guards so the inttypes dont conflict with the ones in sys/types.h and machine/types.h .
Added network interfaces from cygwin 1.5.
Added strtoll and strtoull from cygwin 1.5.
Added the kill.exe function from msysgit.
Removed the strtoull compat function from kill.exe (no longer nessesary with new support).
Removed newlib.h from kbless patch (was not used anywhere).
Removed the unicode function wrappers from kbless patch since atleast gcc 3.4.4 and later cannot compile it,
besides it seems to work just as well without them.
Added nl_langinfo support (experimental may remove if it behaves abnormally).
Fixed a few weak exports from msys pthread functions.
Fixed a bunch of stuff to allow compiling the msys dll with gcc version 4 (cygcheck still links to libstdc++ investigating why).
Changed a few math functions from newlib to use _Ulong instead of _uint32_t (cygwin 1.5).
Big thanks to kbless for the initiall patch it helped a lot.
The folder inside this archive contains a batch script + some tools needed to patch an unmodified source dir
from the msysCORE-1.0.18-1-msys-1.0.18-src.tar.lzma archive.
besides unpacking the source its all automated so it should be pretty straight forward.
unpack this archive somewhere and extract the source directory from the msysCORE-1.0.18-1-msys-1.0.18-src.tar.lzma archive,
to where you unpacked this. Now run patcher.bat (just doubleclick it) and follow the directions.
Now unpack msysCORE-1.0.18-1-msys-1.0.18-src.tar.lzma where you want to build it and replace the source dir inside it with the patched one from here.
Open an msys shell (you need the msysdev package) and be sure its set to MSYS. Cd to the dir where the builddir is and run
./msysrlsbld. When done you should have a bunch of tar archives and an nstl directory. Close the msys shell and copy the contents of the nstl dir
to where your msys is installed. Open a shell again and try building something with multibyte support.