Make the switch detection code much easier to understand by introducing a fewmore preprocessor sql functions.This is partly a showcase of how we can reduce some c code complexity usingthese functions.* build/transform_sql.py (process_file): Add RELPATH_JOIN(x, y), RELPATH_SKIP_ANCESTOR(x, y) and RELPATH_SKIP_JOIN(x, y, z) which is a combination of the other two.* subversion/libsvn_wc/wc-queries.sql (STMT_HAS_SWITCHED): Simplify query. Use additional argument instead of join. (STMT_HAS_SWITCHED_REPOS_ROOT, STMT_HAS_SWITCHED_WCROOT, STMT_HAS_SWITCHED_WCROOT_REPOS_ROOT): Remove queries that can now be handled by STMT_HAS_SWITCHED.* subversion/libsvn_wc/wc_db.c (has_switched_subtrees): Use single query. Pass repository relative path.* subversion/tests/libsvn_wc/wc-queries-test.c (slow_statements): Remove specialized selects on the entire wc.