libtroch_cuda.so is missing in TORCH_LIBRARIES and TORCH_CUDA_LIBRARIES in PyTorch CMake if build flag BUILD_SHARED_LIBS is enabled, for example

find_package(Torch REQUIRED)
# libtorch_cuda.so is missing in TORCH_CUDA_LIBRARIES and TORCH_LIBRARIES
message(STATUS ${TORCH_CUDA_LIBRARIES} ${TORCH_LIBRARIES})

The impact is the user can't find libtorch_cuda.so via PyTorch CMake. They need to find it by themselves. This is not a friendly user experience.

cc @malfet @seemethere @ptrblck @msaroufim