[CMake] cmake on Windows x64

[John Drescher]

> Having CMAKE_SYSTEM_PROCESSOR be "x86" for a 64-bit build is very inconvenient when detecting machine-dependent compiler flags, constructing directory names for outputs based on configuration, configuring third party search directories, etc.  It's always possible to work around (among other things, one can consult the generator string for Visual Studio builds, though not for MinGW builds) but that doesn't mean it shouldn't be better behaved - it's entirely reasonable to assume that CMAKE_SYSTEM_PROCESSOR should be the target processor for the build, especially so that you can have similar behavior on Windows, Linux, and Mac.  Though as previously discussed I also have the opposite problem on Linux when compiling for 32-bit CPU on 64-bit OS.


I see. I have always compared the size of the pointer for this..

John