Yes, good suggestion, thank you. It worked and I was able to compile and run the test script! Also when compiling a running a simple echo hostCPU with the 64 bit compiler I do get amd64 as an answer.
After this succesful experiment my tentative answer to "How does nim infer that a cpu on windows is 64-bit" would be that it is not inferred at all, but instead it is baked in the compiler (both for nim and gcc). A still outstanding issue is how come the choosenim released version `choosenim-0.5.1_windows_amd64.zip` has a i386 baked in instead of amd64. But this I guess it belongs to choosenim issue tracker. I will open an issue there.
