decomposition spectral ops fixes (#108360)
Fixes https://github.com/pytorch/pytorch/issues/105986, https://github.com/pytorch/pytorch/issues/108204, https://github.com/pytorch/pytorch/issues/108205
Fix all issues flagged when making changes for https://github.com/pytorch/pytorch/pull/107421
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108360
Approved by: https://github.com/ezyang
