fix(tvix/eval): implement function/thunk ptr-equality for list ord

With this change, the test introduced by cl/7370 passes.

Change-Id: Ie7d2f02a59d61151f14ebd328e6cfa5892cacfb0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7375
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: Adam Joseph <adam@westernsemico.com>

tvix/eval/src/value/mod.rs

@@ -346,7 +346,7 @@ impl Value {
                         return Ok(Some(Ordering::Greater));
                     } else if i == l1.len() {
                         return Ok(Some(Ordering::Less));
-                    } else if !l1[i].nix_eq(&l2[i], vm)? {
+                    } else if !vm.nix_eq(l1[i].clone(), l2[i].clone(), true)? {
                         return l1[i].force(vm)?.nix_cmp(&*l2[i].force(vm)?, vm);
                     }
                 }