Windows build broken (again)

[Edward Z. Yang]

Maybe it's the Python 3 patches.

Excerpts from Brandon Allbery's message of 2014-10-02 14:00:26 -0700:
> On Thu, Oct 2, 2014 at 4:39 PM, Simon Peyton Jones <simonpj at microsoft.com>
> wrote:
> 
> > Presumably this is some kind of Windows escape-character problem.  But it
> > has worked fine for years, so what is going on?
> 
> 
> At a guess, something that was using / is now using \ and getting eaten by
> the shell. Or quoting that was preventing the \s from being eaten has been
> lost somewhere.
>