Consider migrating crates to slotmap-careful
Right now, these crates use slotmap, which has a bug behavior where version numbers can overflow, causing keys to be reused. (See #1282 (closed).) We have just merged slotmap-careful, a new crate that wraps slotmap and ensures that object keys are always unique.
(It would be lovely to have slotmap implement the behavior we want; see upstream ticket https://github.com/orlp/slotmap/issues/125 .)
There are currently some other crates that use slotmap; we might want to consider migrating them, based on the tradeoffs discussed in the slotmap-careful documentation.
The crates to consider migrating are:
tor-hsclienttor-hsservicetor-memquotator-rtmock