Fix the edge case when y = 0 in kl_div (#82714)
Brought up in https://github.com/pytorch/pytorch/pull/80334#issuecomment-1193600883
We also prepare its opinfo to fix https://github.com/pytorch/pytorch/issues/80488
Pull Request resolved: https://github.com/pytorch/pytorch/pull/82714
Approved by: https://github.com/albanD
