The VMOD does this during .compile(), and QP_Insert() is no longer
called during .add(). The .compile() call is now required in all
cases, and it must be called before .create_stats().

This is because QP_Insert() was not correctly rotating the trie
when a set has overlapping prefixes, and a shorter prefix was
added before the longer one. With sorted order, shorter prefixes
are always added first, so rotation is unnecessary.