pytorch

1f6e3933 - Simplify parametrizations.SpectralNorm and improve its initialization (#59564)

Simplify parametrizations.SpectralNorm and improve its initialization (#59564) Summary: Implements a number of changes discussed with soulitzer offline. In particular: - Initialise `u`, `v` in `__init__` rather than in `_update_vectors` - Initialise `u`, `v` to some reasonable vectors by doing 15 power iterations at the start - Simplify the code of `_reshape_weight_to_matrix` (and make it faster) by using `flatten` Pull Request resolved: https://github.com/pytorch/pytorch/pull/59564 Reviewed By: ailzhang Differential Revision: D29066238 Pulled By: soulitzer fbshipit-source-id: 6a58e39ddc7f2bf989ff44fb387ab408d4a1ce3d