[CMake] CUDA: COMPILE_DEFINITIONS not picked up

[Peter Steinbach]

Hey Karl,

just gave it another shot ... so I can confirm what you saw with cmake 
3.3 (btw, what cmake version did you use?). I should try a more recent 
one to make sure as well.

anyhow, there 2 global workarounds that you have at your disposal:
1) set(CUDA_NVCC_FLAGS "-Dfoo") needs to be called *BEFORE* any 
cuda_add_xxx according to `cmake --help-module FindCUDA`

2) add_definitions(-Dfoo), I called it before cuda_add_xxx too and it 
worked as well

Hope that get's you going -
P