chore: checkpoint before Python removal

vendor/thiserror/src/var.rs

@@ -0,0 +1,9 @@
+use core::fmt::{self, Pointer};
+
+pub struct Var<'a, T: ?Sized>(pub &'a T);
+
+impl<'a, T: Pointer + ?Sized> Pointer for Var<'a, T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Pointer::fmt(self.0, formatter)
+    }
+}