[fx2trt] Add torch.nn.function.pad support for fx2trt (#67498)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67498
Add acc_ops.pad and a converter for it. We want to try padding convolution channel dimension to get better int8 performance.
This one only support padding the last two dimension though. Starting from 8.2, it's suggested to use Slice layer to do padding but this might be nice to have for old version support.
Test Plan: buck test mode/dev-nosan caffe2/test/fx2trt/converters:test_pad
Reviewed By: wushirong
Differential Revision: D32006072
fbshipit-source-id: 96c3aa2aec2d28345d044a88bee2f46aba5cca0e
