[tensorexpr] conv2d handle optional bias (#64750)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64750
conv2d bias is optional. It will be ArgNone in processing of the graph.
This bias is prim::constant NoneType, so we do not know shape at the moment of constant binding.
This adding it as a constant zeros Tensor at the moment of graph processing => for that adding `std::vector<TensorExprKernel::ConstantDescr>& constants and std::vector<at::Tensor>& constant_tensors` to `computeOperandValue` as it is not in `TensorExprKernel`
Test Plan: Imported from OSS
Reviewed By: navahgar
Differential Revision: D30842101
Pulled By: IvanKobzarev
fbshipit-source-id: 88020f6934e43fe606f8eae928b7e21b7c3f15f6
