Summary:
Previously, even when `bottommost_compression_opts`'s `enabled` flag was set, it only took effect when
`bottommost_compression` was also set to something other than `kDisableCompressionOption`.
This wasn't documented and, if we kept the old behavior, it'd make
things complicated like the migration instructions in https://github.com/facebook/rocksdb/issues/7619. We can
simplify the API by making `bottommost_compression_opts` always take
effect when its `enabled` flag is set.
Fixes https://github.com/facebook/rocksdb/issues/7631.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7633
Reviewed By: ltamasi
Differential Revision: D24710358
Pulled By: ajkr
fbshipit-source-id: bbbdf9c1b53c63a4239d902cc3f5a11da1874647
ec346da98c