The default behavior of bin2c is to create binary arrays that have no
null termination. So to use it as a C array we need to explicitly tell
it to create valid null terminated strings.
This will safely allow us to run PTX tests across all CUDA drivers.
The target properties `CUDA_SEPARABLE_COMPILATION` and `CUDA_PTX_COMPILATION`
now aren't mutually exclusive and can now be used together on the same
target.