Grad input padding support for dilation argument (#33872)
Summary:
Fix https://github.com/pytorch/pytorch/issues/16012
It replaces https://github.com/pytorch/pytorch/pull/20684 that has gone stale and simply adds tests on top of it.
These calls used to crash, they now work and return the same value as the backward using the autograd engine.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33872
Differential Revision: D20148360
Pulled By: albanD
fbshipit-source-id: 1113f1a25be238570fa8900fc1be658b61a47802
