[quant][pt2] Fix and rename `move_model_to_eval` (#108891)
Summary:
This commit fixes two silent correctness problems with
the current implementation of `move_model_to_eval`:
(1) Previously the user had to manually call `eliminate_dead_code`
before calling `move_model_to_eval`, otherwise the dropout pattern
won't actually get eliminated. This is because subgraph rewriter
complains the match is not self-contained, and so silently does
not do the replacement.
(2) We wish to error when the user calls `model.train()` or
`model.eval()` on an exported model. This error is raised
correctly immediately after export today, but no longer raised
after the user calls prepare or convert.
We fix (1) by moving the `eliminate_dead_code` call into
`move_model_to_eval`, and fix (2) by ensuring the respective
errors are thrown after prepare and convert as well.
Additionally, this commit renames `move_model_to_eval` to
`move_exported_model_to_eval` to be more explicit.
bypass-github-export-checks
Test Plan:
python test/test_quantization.py TestQuantizePT2E.test_disallow_eval_train
python test/test_quantization.py TestQuantizePT2E.test_move_exported_model_to_eval
Imported from OSS
Differential Revision: D49097293
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108891
Approved by: https://github.com/jerryzh168
