Bug#770588: Bug#769072, #769191, #770588: nvidia-opencl-icd breaking non-nvidia systems

[Rebecca N. Palmer]

>> * nvidia-kernel-dkms: Switch to Recommends: nvidia-driver | libcuda1
>>   to break the chain libcuda1 -> nvidia-kernel-dkms -> nvidia-driver.
> #768185
> suggests that nvidia-opencl-icd works without the graphics side (can
> someone check that?), making this the more correct place to cut the chain.

Sorry, that may not be such a good idea.  #768185 says Nvidia OpenCL + 
Intel graphics can coexist; it says nothing about what would happen to 
an Nvidia-hardware-only system with nvidia kernel module (which 
blacklists the nouveau kernel module) + nouveau graphics userspace, 
which under the above would be the result of trying to install OpenCL on 
a previously nouveau-using system.

That leaves the options of cutting nvidia-opencl-icd -> libcuda1 and 
accepting broken OpenCL as less bad than broken graphics, or making the 
libgl1-nvidia-glx.preinst.in "do you really want to install this?" 
warning trigger on non-Nvidia hardware.