Hash map that is faster but not resilient to DoS attacks.
(Similar to rustc_hash::FxHashMap but using hashbrown::HashMap instead of alloc::collections::HashMap.)
To construct a new instance: FastHashMap::default()
Hash set that is faster but not resilient to DoS attacks.
(Similar to rustc_hash::FxHashSet but using hashbrown::HashSet instead of alloc::collections::HashMap.)