message: Check file extension in visionaray_cuda_compile()
  Can only compile .cu
diff: @@ -11,6 +11,13 @@ function(visionaray_cuda_compile outfiles)
  endif()
  foreach(f ${ARGN})
  + get_filename_component(suffix ${f} EXT)
  +
  + if(NOT ${suffix} STREQUAL ".cu")
  + message(FATAL_ERROR "Cannot cuda_compile file with extension ${suffix}")
  + return()
  + endif()
  +
  if(BUILD_SHARED_LIBS)
  cuda_compile(cuda_compile_obj ${f} SHARED)
  else()
  