Enable CMake support for Windows Phone (_WIN32+_M_ARM) and Windows Store...

... Apps,

Use this recent cmake version (http://cmakems.codeplex.com/) or future cmake that has the Windows Phone/Store App support
Use the following defines in CMake:
-DCMAKE_SYSTEM_NAME=WindowsPhone or -DCMAKE_SYSTEM_NAME=WindowsStore
-DCMAKE_SYSTEM_VERSION=8.0 or -DCMAKE_SYSTEM_VERSION=8.1
Thanks to Microsoft OSS group for the patch!