Bug#861878: nvidia-cuda-toolkit: nvcc needs to pass -fpie to compiler

[Lumin]

>> That means, the "build your whole application with clang-3.8"
>> advise is temporary and specific to CUDA 8.0. Before uploading
>> CUDA 9.0 to unstable/experimental, we can change the default
>> compiler back to GCC. And backporting CUDA 9.0 to stretch
>> will eliminate the compiler trouble.
>
> It would be interesting to know how GCC 7 plays along with CUDA 9.0

NVIDIA didn't say anything about CUDA 9.0's support on GCC-7.
This is to be tested.