FindCUDA: drop CUDA_dl_LIBRARY

There is the global CMAKE_DL_LIBS setting which can be used instead. There are
even platforms where this is either empty because those functions are part of
the libc or is called entirely different, so this code wouldn't work reliable
anyway.

Modules/FindCUDA.cmake

@@ -764,13 +764,9 @@ if(CUDA_USE_STATIC_CUDA_RUNTIME)
     if (NOT APPLE)
       # Here is librt that has things such as, clock_gettime, shm_open, and shm_unlink.
       find_library(CUDA_rt_LIBRARY rt)
-      find_library(CUDA_dl_LIBRARY dl)
       if (NOT CUDA_rt_LIBRARY)
         message(WARNING "Expecting to find librt for libcudart_static, but didn't find it.")
       endif()
-      if (NOT CUDA_dl_LIBRARY)
-        message(WARNING "Expecting to find libdl for libcudart_static, but didn't find it.")
-      endif()
     endif()
   endif()
 endif()
@@ -793,13 +789,10 @@ set(CUDA_LIBRARIES)
 if(CUDA_BUILD_EMULATION AND CUDA_CUDARTEMU_LIBRARY)
   list(APPEND CUDA_LIBRARIES ${CUDA_CUDARTEMU_LIBRARY})
 elseif(CUDA_USE_STATIC_CUDA_RUNTIME AND CUDA_cudart_static_LIBRARY)
-  list(APPEND CUDA_LIBRARIES ${CUDA_cudart_static_LIBRARY} ${CMAKE_THREAD_LIBS_INIT})
+  list(APPEND CUDA_LIBRARIES ${CUDA_cudart_static_LIBRARY} ${CMAKE_THREAD_LIBS_INIT} ${CMAKE_DL_LIBS})
   if (CUDA_rt_LIBRARY)
     list(APPEND CUDA_LIBRARIES ${CUDA_rt_LIBRARY})
   endif()
-  if (CUDA_dl_LIBRARY)
-    list(APPEND CUDA_LIBRARIES ${CUDA_dl_LIBRARY})
-  endif()
   if(APPLE)
     # We need to add the default path to the driver (libcuda.dylib) as an rpath, so that
     # the static cuda runtime can find it at runtime.