Rollup merge of rust-lang#131923 - ranger-ross:impl-copy-hash-interrorkind, r=tgross35

Derive `Copy` and `Hash` for `IntErrorKind`

This PR derives `Copy` and `Hash` for `IntErrorKind` to make it easier to work with. (see rust-lang#131826)

I think an argument could be made to also derive `PartialOrd` + `Ord` as well given that other error kinds in the std like [`io::ErrorKind`](https://doc.rust-lang.org/src/std/io/error.rs.html#212-428) do this. Granted these seem much less useful for errors.

Fixes rust-lang#131826

Author: matthiaskrgr

core/src/num/error.rs

@@ -79,7 +79,7 @@ pub struct ParseIntError {
 /// # }
 /// ```
 #[stable(feature = "int_error_matching", since = "1.55.0")]
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Copy, Hash)]
 #[non_exhaustive]
 pub enum IntErrorKind {
     /// Value being parsed is empty.