pytorch

ad94248b - Cleanup dead code (#63328)

Cleanup dead code (#63328) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/63328 This code supported the old `at::_fft_with_size` operator which no longer exists. Test Plan: Imported from OSS Reviewed By: astaff Differential Revision: D30343557 Pulled By: mruberry fbshipit-source-id: 7a71585e013acb46c98f14fd40e15bdfbf026bac