Windows devs - how are you building dmd, druntime, phobos?

[Atila Neves]

For dmd, neither win32.mak or win64.mak work for me at all. I'm 
at a loss as to how they work for the autotester. Fortunately I 
learned about build.d on github, and that works fine.

But then I tried druntime and couldn't build that with the 
Windows makefile. There's no build.d there though, at least not 
with that name. The makefile seems to try creating directories 
more than once and fails.

Given all the above, how is that people on Windows manage to work 
on the 3 core D repos? I'm trying to fix the situation (mostly so 
I can get the dmd bash tests to run there), but first I'd like to 
know if I'm doing something wrong.

Bear in mind I've build all 3 repos repeatedly on Windows 
before...