bloom: ignore renames when computing changed paths

bloom: ignore renames when computing changed paths

The changed-path Bloom filters record an entry in the filter for
every path that was changed. This includes every add and delete,
regardless of whether a rename was detected. Detecting renames
causes significant performance issues, but also will trigger
downloading missing blobs in partial clone.

The simple fix is to disable rename detection when computing a
changed-path Bloom filter. This should already be disabled by
default, but it is good to explicitly enforce the intended
behavior.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>