[ONNX] De-duplicate initializers (#68202) (#69547)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69547
ScriptModule export introduces duplicated ONNX initializers for shared weights, unnecessarily increases ONNX model size. This PR de-duplicates ONNX initializers for model exported in eval mode, by checking if the underlying tensors share the same `data_ptr`, `strides` and `sizes`.
Test Plan: Imported from OSS
Reviewed By: msaroufim
Differential Revision: D32994271
Pulled By: malfet
fbshipit-source-id: 10ac66638b6255890875272472aa9ed07a5b1d9a
Co-authored-by: BowenBao <bowbao@microsoft.com>
(cherry picked from commit d7cbde940c5c259a3feff5af870b01dd21fbf3e0)
