dmd, x64 and Windows

[Iain Buclaw]

== Quote from Andrej Mitrovic (andrej.mitrovich at gmail.com)'s article
> I've been trying to compile GDC the last couple of days. I've ran into
> some issues, but I've put them in GDC tickets and it seems from the
> last comments that Iain Buclaw has managed to create a cross-compiler
> setup and working. This is all last-minute info so I don't know if
> we'll have GDC working on Windows just yet.

D2 Ming32 cross-compiler built, but haven't yet tested the quality of the object
files outputted (will no doubt be using WINE).

Changeset: https://bitbucket.org/goshawk/gdc/changeset/978bb5bc82cf

And briefly documented, as I *will* forget when the morning comes:
https://bitbucket.org/goshawk/gdc/wiki/MinGWCrossCompile