Compiler relocation with MinGW [Re: r50 mingw32 doesn't work]

[Anders F Björklund]

> Thanks for the info, I will try this with the gdcwin 3.4.5 build later.
> (will do the fake /gdc mount, instead of installing in /mingw like now)

Worked like a charm, built with --prefix=/gdc and later the
EXE installed into /mingw (C:\MinGW) without any problems...

I built GDC trunk SVN r20 for mac/win as a dress rehearsal
for the 0.20 release, that hopefully should be relocatable.

Thanks!
--anders

PS.
This time I included both "gdc.exe" and "mingw32-gdc.exe",
similar to "gdc" and "gdc-4.0" for the Mac OS X version.