feat: octal Debug representation of tree::EntryMode.

This makes it easier to reason about.

Author: Byron

gix-object/src/tree/mod.rs

@@ -42,10 +42,16 @@ pub struct Editor<'a> {
 ///
 /// Note that even though it can be created from any `u16`, it should be preferable to
 /// create it by converting [`EntryKind`] into `EntryMode`.
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Ord, PartialOrd, Hash)]
+#[derive(Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct EntryMode(pub u16);
 
+impl std::fmt::Debug for EntryMode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "EntryMode({:#o})", self.0)
+    }
+}
+
 /// A discretized version of ideal and valid values for entry modes.
 ///
 /// Note that even though it can represent every valid [mode](EntryMode), it might