impl Debug for DecInt

This is a best practice to be friendly to users who may want
to add things to their own structs and want to simply `#[derive(Debug)]`
and I'm assuming its omission was accidental.

Author: cgwalters

src/path/dec_int.rs

@@ -6,6 +6,8 @@
 
 use crate::ffi::ZStr;
 use crate::imp::fd::{AsFd, AsRawFd};
+#[cfg(feature = "std")]
+use core::fmt;
 use core::fmt::Write;
 use itoa::{Buffer, Integer};
 #[cfg(feature = "std")]
@@ -123,3 +125,10 @@ impl AsRef<Path> for DecInt {
         Path::new(as_os_str)
     }
 }
+
+#[cfg(feature = "std")]
+impl fmt::Debug for DecInt {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.as_str().fmt(fmt)
+    }
+}