Raise error if `at::native::embedding` is given 0-D weight (#42550)
Summary:
Previously, `at::native::embedding` implicitly assumed that the `weight` argument would be 1-D or greater. Given a 0-D tensor, it would segfault. This change makes it throw a RuntimeError instead.
Fixes https://github.com/pytorch/pytorch/issues/41780
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42550
Reviewed By: smessmer
Differential Revision: D23040744
Pulled By: albanD
fbshipit-source-id: d3d315850a5ee2d2b6fcc0bdb30db2b76ffffb01
