wc-queries-test.c

Avoid nested full table scans on two tables in a single query by rewriting the
query to a completely different pattern.

Only operate on the relevant subset of the actual table to avoid doing unneeded
work on all other nodes in the working copy.

The IN (select local_relpath FROM .. WHERE .. AND kind = 'qqq') style
queries are not optimized by Sqlite to use a select on local_relpath.

Depending on the number of affected nodes and nodes in the working copy, this
query is now orders of magnitude faster.

* subversion/libsvn_wc/wc-queries.sql
(STMT_UPDATE_ACTUAL_CHANGELISTS): Rewrite query.

* subversion/libsvn_wc/wc_db.c
(set_changelist_txn): Pass the operation root as second argument.

* subversion/tests/libsvn_wc/wc-queries-test.c
(slow_statements): Remove another slow statement from the list.