[SR] Use at::DimVector in reshape_copy_out (#76473)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76473
Avoid some extra heap allocations by using DimVector
ghstack-source-id: 155569314
Test Plan: Existing unit tests
Reviewed By: navahgar, huiguoo
Differential Revision: D35972439
fbshipit-source-id: 971998d6bcaaf9bb598772f1e2ca6b13f29f92a4
(cherry picked from commit f2b70c38fffe6355cd8b2f0eb36f299c0d50e5d8)
