message: syntax: add PartialOrd/Ord to types
diff: @@ -95,7 +95,7 @@ const MAX_UTF8_BYTES: usize = 4;
  ///
  /// For example, if there are two ranges, `[C2-DF][80-BF]`, then the byte
  /// sequence `\xDD\x61` would not match because `0x61 < 0x80`.
  -#[derive(Copy, Clone, Eq, PartialEq)]
  +#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord)]
  pub enum Utf8Sequence {
  /// One byte range.
  One(Utf8Range),
  @@ -191,7 +191,7 @@ impl fmt::Debug for Utf8Sequence {
  }
  /// A single inclusive range of UTF-8 bytes.
  -#[derive(Clone, Copy, PartialEq, Eq)]
  +#[derive(Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
  pub struct Utf8Range {
  /// Start of byte range (inclusive).
  pub start: u8,
  