Relevance of SHARED option in CMakeLists "add_library" function

[cguzman95]

Hello @mattldawson ,

I'm merging some changes on CMakeLists from the main branch to my branch, and in the process this warning triggers when compiling with GPU:

nvlink warning : SM Arch ('sm_30') not found in 'CMakeFiles/camplib.dir/src/cuda/camp_gpu_solver.cu.o'

Seems this warning is triggered by setting the SHARED option from "add_library" function, like this:

What is the relevante of SHARED option? It is needed for some test or the fix can be delayed to some point in the future?