[quant][graphmode][fx] Make maxpool and flatten produce the reference pattern (#63501)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63501
Currently some of the ops are considered as working with both float and quantized input,
so we may have things like "quant - some_op - dequant" this might not work well with the backend,
we may consider change everything to produce "quant - dequant - some_op - quant - dequant" instead
in the future, this PR fixes it for maxpool and flatten only to unblock resnet benchmarking on TensorRT
Test Plan:
python test/test_quantization.py TestQuantizeFxOps
Imported from OSS
Reviewed By: mruberry
Differential Revision: D30402788
fbshipit-source-id: 892c5ff6552775070e2c1453f65846590fb12735
