SymIntify convolution backend calculation (#89069)
We will need this to implement a convolution meta function that
is SymInt aware. I use templates so that regular convolution code
is not affected by the change. No tests for symbolic ints directly; that will
come in a subsequent PR which also needs to refactor fake tensors.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89069
Approved by: https://github.com/SherlockNoMad
