Reserve the memory for vector to save cost in `gather_ranges_to_dense_op.h` (#73540)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/73540
Reviewed By: r-barnes
Differential Revision: D34492500
fbshipit-source-id: f973931b05880c76c82f799d1b40b128078d6702
(cherry picked from commit 64a51de23efaca0d29df88d141aaea40fadddbb0)
