[CMake] Win32 multi-platform settings

[Bill Hoffman]

Steven Wilson wrote:
> Visual Studio supports having solution files where the solution can set 
> the supported platform to x64 and yet have individual projects in the 
> solution build for the Win32 platform despite having the solution set to 
> x64.   Can I configure CMake to set up projects/solutions in this fashion?
> 

Currently no.  You need a build tree for each.

-Bill