Before this patch the functions below returns incorrect type for consts,
and hence optimize_skip_unused_shards does not work:
- cutToFirstSignificantSubdomainCustom()
- cutToFirstSignificantSubdomainCustomWithWWW()
- firstSignificantSubdomainCustom()
Custom TLD lists (added in #17748), may contain domain of the 3-d level,
however builtin TLD lists does not have such records, so it is not
affected.
Note that this will significantly increase hashtable lookups.
Fixes: #17748