Replace resize_dim() with set_sizes_and_strides() in (#15348)

Replace resize_dim() with set_sizes_and_strides() in (#15348)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15348

We have a function resize_dim() on TensorImpl in c10/core/TensorImpl.h which lets you change the dimensionality of a tensor, resizing both sizes and strides. Unfortunately, this API is fairly easy to misuse, because it fills in the new entries with garbage when you size it larger. We want to refactor the call sites to use set_sizes_and_strides() instead, so that there is never an intermediate tensor state where the sizes/strides don't make sense. In this diff, resize_dim() is
replaced with set_sizes_and_strides() in aten/src/TH/THTensor.hpp.

Reviewed By: ezyang

Differential Revision: D13505512

fbshipit-source-id: 193bab89f0018c13ca07488be336d8e967746b76