message: Mark iterator functions inline
  Summary: Functions are trivial.
diff: @@ -24,10 +24,12 @@ macro_rules! def_iter {
  self.iter.next().map(Self::map)
  }
  + #[inline]
  fn nth(&mut self, n: usize) -> Option<Self::Item> {
  self.iter.nth(n).map(Self::map)
  }
  + #[inline]
  fn last(mut self) -> Option<Self::Item> {
  // Since these are all double-ended iterators we can skip to the end quickly
  self.iter.next_back().map(Self::map)
  @@ -38,10 +40,12 @@ macro_rules! def_iter {
  self.iter.size_hint()
  }
  + #[inline]
  fn count(self) -> usize {
  self.iter.len()
  }
  + #[inline]
  fn collect<C>(self) -> C
  where
  C: std::iter::FromIterator<Self::Item>,
  