[pytorch][codegen] gen_python_functions.py loading native_functions.yaml / deprecated.yaml directly (#47746)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47746
- Removed the integration hack in gen_python_functions.py. It now directly
loads native_functions.yaml. All dependencies on Declarations.yaml
have been removed / moved to elsewhere.
- Rewrote the deprecated.yaml parsing logic to work with new data model directly.
Confirmed byte-for-byte compatible with the old codegen:
```
Run it before and after this PR:
.jenkins/pytorch/codegen-test.sh <baseline_output_dir>
.jenkins/pytorch/codegen-test.sh <test_output_dir>
Then run diff to compare the generated files:
diff -Naur <baseline_output_dir> <test_output_dir>
```
Differential Revision: D24885067
Test Plan: Imported from OSS
Reviewed By: bhosmer
Pulled By: ljk53
fbshipit-source-id: 8e906b7dd36a64395087bd290f6f54596485ceb4
