I\'ve written a detailed tutorial that incorporates the top two answers on this question: http://blog.johannesmp.com/2015/09/01/installing-clang-on-windows-pt1/
Try installing MSYS2 and then installing the mingw-w64-x86_64-clang (binary) package:
pacman -S mingw-w64-x86_64-clang
It is a bit old at the moment (3.6.2), but it might be good enough for you. Then when you run the Win64 shell provided by MSYS2, clang will be on your path.
If it's not good enough, I have recently been building a 64-bit version of clang with MSYS2 and using it to compile native 64-bit Windows executables. My process was something like:
export MINGW_INSTALLS=mingw64 (so you are only compiling the 64-bit version), and then run makepkg-mingw.It is unlikely you will get everything right on the first try, and some files might need to be edited. Clang may have changed since the last time I did this and some patches might not apply cleanly.