message: be explicit about types
diff: @@ -132,9 +132,9 @@ impl Default for MiriConfig {
  forwarded_env_vars: vec![],
  args: vec![],
  seed: None,
  - tracked_pointer_tags: Default::default(),
  - tracked_call_ids: Default::default(),
  - tracked_alloc_ids: Default::default(),
  + tracked_pointer_tags: HashSet::default(),
  + tracked_call_ids: HashSet::default(),
  + tracked_alloc_ids: HashSet::default(),
  tag_raw: false,
  data_race_detector: true,
  cmpxchg_weak_failure_rate: 0.8,
  