Update on "[PyTorch] Use .sizes() isntead of .size() in cat_serial_ke…

…rnel_impl"

As with previous diff, .sizes() is strictly more efficient.

Differential Revision: [D25546409](https://our.internmc.facebook.com/intern/diff/D25546409/)

**NOTE FOR REVIEWERS**: This PR has internal Facebook specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D25546409/)!

[ghstack-poisoned]

aten/src/ATen/native/cpu/CatKernel.cpp

@@ -20,6 +20,8 @@ struct InputMeta {
 
 template <typename scalar_t>
 void cat_serial_kernel_impl(Tensor& result, TensorList tensors, int64_t dim) {
+  TORCH_INTERNAL_ASSERT_DEBUG_ONLY(
+      dim >= 0 && dim < result.dim(), "dim out of range in cat_serial_kernel_impl");
   int64_t outer = result.numel() / (result.sizes()[dim] * result.strides()[dim]);
   scalar_t* result_data = result.data_ptr<scalar_t>();
   int64_t ninputs = tensors.size();