message: style: use sum instead of fold
diff: @@ -410,7 +410,7 @@ impl InstRanges {
  self.ranges
  .iter()
  .map(|&(s, e)| 1 + (e as u32) - (s as u32))
  - .fold(0, |acc, len| acc + len) as usize
  + .sum::<u32>() as usize
  }
  }
  