[CMake] How can I tell the ninja generator on Windows to use cl.exe?

[Nico Weber]

Hi,

when I installed MinGW, `cmake -G Ninja` started producing ninja files
that use MinGW's gcc to compile source files. How can I tell cmake to
generate ninja files that use cl.exe instead?

I tried searching for "cmake ninja mingw msvs" and a few related
terms, but I didn't find anything.

Thanks,
Nico