VS: Set CUDA TargetMachinePlatform explicitly on x64
The TargetMachinePlatform
setting tells CUDA what --machine {32,64}
flag to pass to nvcc. While CUDA automatically chooses the proper
default for the target architecture, it does not reflect this in the
user-visible IDE settings. Set it explicitly to fix the user-visible
setting.
Fixes: #17355 (closed)