cmake LibDL examples

google/filament third_party/civetweb/src/CMakeLists.txt :51 

find_package(LibDl)

feelpp/feelpp feelpp/contrib/ginac/CMakeLists.txt :180 

find_package(LibDL)

lattice/quda lib/targets/cuda/target_cuda.cmake :528 

find_package(LibDL)