Implement is_qat in TorchVision

[datumbox]

Due to the breaking changes introduced at pytorch/pytorch#70009 and pytorch/pytorch#71956, TorchVision needs to make changes on the quantization code. This PR should make adjustments in a BC manner.

Before merging:

• CI needs to pass. Waiting for the PyTorch nightly to include the PR with the above changes.
• Verify Reference Scripts:
  • QAT training
  • PTQ training
  • Accuracy for ResNet18
  • Accuracy for MobileNetV2
  • Accuracy for MobileNetV3 Large model

cc @jerryzh168

[facebook-github-bot]

💊 CI failures summary and remediations

As of commit 3880b53 (more details on the Dr. CI page):

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• 2/2 failures introduced in this PR

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🕵️ 1 new failure recognized by patterns

The following CI failures do not appear to be due to upstream breakages:

CodeQL / build (1/1)

Step: "Build TorchVision" (full log | diagnosis details | 🔁 rerun)

2022-02-02T10:27:08.1513828Z ##[error]Process completed with exit code 1.

2022-02-02T10:27:08.0119076Z     self.finalize_options()
2022-02-02T10:27:08.0119591Z   File "/home/runner/.local/lib/python3.8/site-packages/setuptools/command/develop.py", line 52, in finalize_options
2022-02-02T10:27:08.0119987Z     easy_install.finalize_options(self)
2022-02-02T10:27:08.0120551Z   File "/home/runner/.local/lib/python3.8/site-packages/setuptools/command/easy_install.py", line 276, in finalize_options
2022-02-02T10:27:08.0120938Z     self._fix_install_dir_for_user_site()
2022-02-02T10:27:08.0121520Z   File "/home/runner/.local/lib/python3.8/site-packages/setuptools/command/easy_install.py", line 382, in _fix_install_dir_for_user_site
2022-02-02T10:27:08.0121900Z     self.create_home_path()
2022-02-02T10:27:08.0122566Z   File "/home/runner/.local/lib/python3.8/site-packages/setuptools/command/easy_install.py", line 1338, in create_home_path
2022-02-02T10:27:08.0123011Z     if path.startswith(home) and not os.path.isdir(path):
2022-02-02T10:27:08.0123448Z AttributeError: 'int' object has no attribute 'startswith'
2022-02-02T10:27:08.1513828Z ##[error]Process completed with exit code 1.
2022-02-02T10:27:08.1607791Z Post job cleanup.
2022-02-02T10:27:08.2747632Z [command]/usr/bin/git version
2022-02-02T10:27:08.2799435Z git version 2.35.1
2022-02-02T10:27:08.2831752Z [command]/usr/bin/git config --local --name-only --get-regexp core\.sshCommand
2022-02-02T10:27:08.2878204Z [command]/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'core\.sshCommand' && git config --local --unset-all 'core.sshCommand' || :
2022-02-02T10:27:08.3229793Z [command]/usr/bin/git config --local --name-only --get-regexp http\.https\:\/\/github\.com\/\.extraheader
2022-02-02T10:27:08.3265871Z http.https://github.com/.extraheader
2022-02-02T10:27:08.3276092Z [command]/usr/bin/git config --local --unset-all http.https://github.com/.extraheader
2022-02-02T10:27:08.3320673Z [command]/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'http\.https\:\/\/github\.com\/\.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :
2022-02-02T10:27:08.3850888Z Cleaning up orphan processes

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1 failure not recognized by patterns:

Job	Step	Action
cmake_macos_cpu	curl -o conda.sh https://repo.anaconda.com/miniconda/Miniconda3-latest-MacOSX-x86_64.sh
sh conda.sh -b
source $HOME/miniconda3/bin/activate
conda install -yq conda-build cmake
packaging/build_cmake.sh
	🔁 rerun

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[jerryzh168]

would you like to use fuse_model and fuse_model_qat or the flag?

[datumbox]

Thanks for the comment. Apologies, I'm not sure I follow. Could you clarify?

[jerryzh168]

Looks good I think, thanks for updating the APIs!