64bit phobos on Windows?

[Richard Webb]

I know that 64bit support on Windows is behind Linux etc for various reasons,
but i thought i'd tried building some things with -m64 just to test, and got a
bunch of errors like

std\file.d(223): Error: undefined identifier GetLastError
std\file.d(2067): Error: undefined identifier WIN32_FIND_DATA

Which appears to be because various things in Phobos use version(Win32), and
only 'Win64' is set in 64bit builds.
I guess that at least some of these should be using version(Windows) instead?