pytorch

279b5372 - [not for land] fix fx quant for quant_layer -> stack -> sum (#53196)

[not for land] fix fx quant for quant_layer -> stack -> sum (#53196) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/53196 Before this PR, code patterns like this did not work: ``` x = some_quant_layer(x) x = torch.stack([x, ...]) x = torch.sum(x, ...) ``` The reason this did not work is because `torch.sum` is treated as "quantized" because of the newly added fp16 support, even though it is not actually "quantized" for models where fp16 is not used. We may need to adjust the concept of "quantized vs non-quantized" into a "dtype" for the longer term fix. The current PR is a hacky fix to unblock. We need to clean things up before this is landable Test Plan: ``` python test/test_quantization.py TestQuantizeFx.test_quant_sum ``` Imported from OSS Reviewed By: jerryzh168 Differential Revision: D26783960 fbshipit-source-id: 3be7c3c1eaa2b8fcb99a105e1b0004c9ffd3a1c1