Support ReduceSum in c2_pt_converter (#47889)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47889
Adds support for converting the [caffe2 ReduceSum](https://caffe2.ai/docs/operators-catalogue#reducesum) operator to torch.
ghstack-source-id: 116580127
Test Plan:
buck test //caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test : [results](https://our.intern.facebook.com/intern/testinfra/testrun/6755399466095119)
✓ ListingSuccess: caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test - main (60.273)
✓ Pass: caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test - test_sub_op (caffe2.torch.fb.model_transform.c2_convert.c2_pt_converter_test.C2PTConverterTest) (101.119)
✓ Pass: caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test - test_layer_norm_conversion (caffe2.torch.fb.model_transform.c2_convert.c2_pt_converter_test.C2PTConverterTest) (101.404)
✓ Pass: caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test - test_local_model_conversion (caffe2.torch.fb.model_transform.c2_convert.c2_pt_converter_test.C2PTConverterTest) (101.966)
✓ Pass: caffe2/torch/fb/model_transform/c2_convert:c2_pt_converter_test - test_reduce_sum (caffe2.torch.fb.model_transform.c2_convert.c2_pt_converter_test.C2PTConverterTest) (114.896)
Reviewed By: bugra
Differential Revision: D24925318
fbshipit-source-id: 3f3b791eff1b03e8f5adee744560fe8bc811c659
