Fix win arg patch for BUILD_SPLIT_CUDA=ON (#3419)

Author: peterjc123

CMakeLists.txt

@@ -44,7 +44,15 @@ if(MSVC)
       string(APPEND CMAKE_CUDA_FLAGS " -Xcudafe --diag_suppress=${diag}")
     endforeach()
     CUDA_CONVERT_FLAGS(torch_cpu)
-    CUDA_CONVERT_FLAGS(torch_cuda)
+    if(TARGET torch_cuda)
+      CUDA_CONVERT_FLAGS(torch_cuda)
+    endif()
+    if(TARGET torch_cuda_cu)
+      CUDA_CONVERT_FLAGS(torch_cuda_cu)
+    endif()
+    if(TARGET torch_cuda_cpp)
+      CUDA_CONVERT_FLAGS(torch_cuda_cpp)
+    endif()
   endif()
 endif()