Summary:
Pull Request resolved: https://github.com/facebookresearch/faiss/pull/3247
add a context parameter to be passed to InvertedLists and InvertedListsIterator.
- add a context field in `SearchParametersIVF`, the context will be passed to `InvertedLists::get_iterator`. The user can create `InvertedListsIterator` with the context object
- add a context parameter in `IndexIVF::add_core` method. the context will be passed to `InvertedLists::add_entry`.
The user can use the context object to pass storage handlers, store error codes from storage layer, logging information, etc.
Reviewed By: mdouze
Differential Revision: D53113911
fbshipit-source-id: ff31d247d3dc949d0bb50bcaffc3142efd027089
Xiaozhong Pan