Make svd / svdvals fully functorch compatible (#72181)
Summary:
This should (hopefully) make all the CI from `functorch` go green (including jvp's!) after changing `VARIADIC_BDIMS_BOXED(_svd_helper);` with `VARIADIC_BDIMS_BOXED(_linalg_svd);` and removing all the skip and xfails associated to `linalg.svdvals`.
Locally, there's just one test that started failing because of this, and that is `test_vmapjvpall_norm_nuc_cpu_float32`. I have no idea what's going on here, but it's a jvp product, so not a regression, and it might very well be caused by the jvp of other operation within `norm_nuc` as this is a composite operation.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72181
Reviewed By: ngimel
Differential Revision: D33952744
Pulled By: zou3519
fbshipit-source-id: 2a2510d97eed4a0bfc25615264ddd36e38856efe
(cherry picked from commit 5805fa107c3a91c58f8ecc9778cfc87aa7f64233)
