pytorch

4acd14da - ns for fx: preserve observers and fake_quants through passes (#61323)

ns for fx: preserve observers and fake_quants through passes (#61323) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/61323 Before this PR, all observers and fake quants were silently removed when adding loggers with NS. This is problematic for QAT models because we need the fake quants to run in order to properly capture intermediate outputs. This PR fixes the issue by preserving the observers throughout the passes which add loggers. In detail: * for each quantization module or fusion, add additional patterns with that fusion and an observer/fake_quant at the end * remove the places in the logger model creation code which removed observers * add unit testing that QAT numerics do not change after adding loggers Test Plan: ``` python test/test_quantization.py TestFXNumericSuiteCoreAPIs.test_loggers_preserve_qat_numerics python test/test_quantization.py TestFXNumericSuiteCoreAPIs.test_shadow_loggers_preserve_qat_numerics ``` Imported from OSS Reviewed By: hx89 Differential Revision: D29600351 fbshipit-source-id: 5f25118b79eb47860c49bca882de6a8eae7a4456