Allow relocatable device code linking in pytorch CUDA extensions (#78225)
Close https://github.com/pytorch/pytorch/issues/57543
Doc: check `Relocatable device code linking:` in https://docs-preview.pytorch.org/78225/cpp_extension.html#torch.utils.cpp_extension.CUDAExtension
Pull Request resolved: https://github.com/pytorch/pytorch/pull/78225
Approved by: https://github.com/ezyang, https://github.com/malfet
