[Mingw-w64-public] MSYS updated

[Ruben V. B. <van...@gm...>]

I have uploaded an updated MSYS package dated today, which includes the
latest MSYSCore update. That's about the only difference with the previous
archive. Not really worth updating if you ask me, but if you are a
fool-of-the-latest-and-greatest like me, please download away!

NB: link.exe is reincluded, after some confusion (completely from my part
with regards to the IMHO botched GMP configure script) which led to its
removal.