message: Fix bug in `Limits::free`
diff: @@ -117,7 +117,7 @@ impl Limits {
  /// [`reserve`]: #method.reserve
  pub fn free(&mut self, amount: u64) {
  if let Some(max_alloc) = self.max_alloc.as_mut() {
  - *max_alloc -= std::cmp::min(*max_alloc, amount);
  + *max_alloc = max_alloc.saturating_add(amount);
  }
  }
  }
  