Skip inserting duplicate observers (#25504)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25504
Skip inserting duplicate observers for values observed
in forward method of a child module or other methods in
the current module.
Test Plan:
python test/test_jit.py -- 'TestJit.insert_observers'
python test/test_jit.py -- 'TestJit.insert_observers_child_qconfig'
python test/test_jit.py -- 'TestJit.insert_observers_skip_values'
Imported from OSS
Differential Revision: D17208888
fbshipit-source-id: e04f1c22ab1c4f410933a17a3ef31acf5f217323
