message: Align first_hole configuration with single use
  Resolves dead_code warning in test configuration
diff: @@ -80,6 +80,7 @@ impl HoleList {
  }
  /// Returns information about the first hole for test purposes.
  + #[cfg(not(target_os = "hermit"))]
  #[cfg(test)]
  pub fn first_hole(&self) -> Option<(usize, usize)> {
  self.first
  