The only reason why it's there (right next to compaction_fwd.hh) is
because the database::table_truncate_state subclass needs the definition
of compaction_manager::compaction_reenabler subclass.
However, the former sub is not used outside of database.cc and can be
defined in .cc. Keeping it outside of the header allows dropping the
compaction_manager.hh from database.hh thus greatly reducing its fanout
over the code (from ~180 indirect inclusions down to ~20).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#13622
5e201b9120