search buffers for dtype
Author: cyyever
Pull request: yes

# What does this PR do?

This PR extends the logic of get_parameter_dtype to search buffers after parameters are searched. If a model is frozen such that all its parameters are turned into buffers, the current logic may not be able to find a dtype even if it tries to search module.\_\_dict\_\_.
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Comments:
_The documentation is not available anymore as the PR was closed or merged._