Change assertion throw to error message for const_run_impl call. (#121396)
Summary:
Currently we do not have a easy mechanism to distinguish between models created with some specific config.
We use a warning instead of failing directly.
Test Plan: Messaging change only.
Reviewed By: aakhundov
Differential Revision: D54622522
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121396
Approved by: https://github.com/chenyang78
