don't use size()/stride() functions in TensorImpl, use size_[d]/stride_[d] instead (#30452)
Summary:
This improved multi-d microbenchmark by ~100 ns, empty_tensor_restride used to be 13% of iteration time, now about 5%
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30452
Test Plan: Covered by existing tests
Differential Revision: D18704233
Pulled By: ngimel
fbshipit-source-id: be527f09183bc31e9d1f63fd49bfbe0998fe167f
