[quant][graphmode] quantization support for aten::add (#34572)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/34572
Test Plan:
python test/test_jit.py
Imported from OSS
Differential Revision: D20519607
fbshipit-source-id: c57e062cffc24a47a76b73b58aff7f9ef80183fa
