Deduplicate some repeated tests

This removes one of each pair of equivalent tests duplicated within
`gix-index` and (separately) within `gix-pack`. See GitoxideLabs#1685.

gix-index/src/lib.rs

@@ -237,36 +237,3 @@ pub(crate) mod util {
         data.split_at(pos).into()
     }
 }
-
-// FIXME: Probably remove these in favor of the equivalent tests in `gix-index/tests/index/mod.rs`.
-#[cfg(test)]
-mod tests {
-    use gix_testtools::size_ok;
-
-    #[test]
-    fn size_of_entry() {
-        let actual = std::mem::size_of::<crate::Entry>();
-        let expected = 80;
-        assert!(
-            size_ok(actual, expected),
-            "the size of this structure should not change unexpectedly: {actual} <~ {expected}"
-        );
-    }
-
-    #[test]
-    fn size_of_entry_time() {
-        // The reason we have our own time is that it is half the size.
-        let ent_actual = std::mem::size_of::<crate::entry::stat::Time>();
-        let ent_expected = 8;
-        assert!(
-            size_ok(ent_actual, ent_expected),
-            "the size of this structure should not change unexpectedly: {ent_actual} <~ {ent_expected}"
-        );
-        let ft_actual = std::mem::size_of::<filetime::FileTime>();
-        let ft_expected = 16;
-        assert!(
-            size_ok(ft_actual, ft_expected),
-            "we will want to know if the size of this structure changes: {ft_actual} <~ {ft_expected}"
-        );
-    }
-}

gix-pack/src/cache/delta/mod.rs

@@ -22,40 +22,3 @@ pub mod from_offsets;
 mod tree;
 
 pub use tree::{Item, Tree};
-
-// FIXME: Probably remove this pair of tests or the equivalent pair in `gix-pack/src/cache/delta/tree.rs`.
-#[cfg(test)]
-mod tests {
-    use super::Item;
-    use gix_testtools::size_ok;
-
-    #[test]
-    fn size_of_pack_tree_item() {
-        let actual = std::mem::size_of::<[Item<()>; 7_500_000]>();
-        let expected = 300_000_000;
-        assert!(
-            size_ok(actual, expected),
-            "we don't want these to grow unnoticed: {actual} <~ {expected}"
-        );
-    }
-
-    #[test]
-    fn size_of_pack_verify_data_structure() {
-        pub struct EntryWithDefault {
-            _index_entry: crate::index::Entry,
-            _kind: gix_object::Kind,
-            _object_size: u64,
-            _decompressed_size: u64,
-            _compressed_size: u64,
-            _header_size: u16,
-            _level: u16,
-        }
-
-        let actual = std::mem::size_of::<[Item<EntryWithDefault>; 7_500_000]>();
-        let expected = 840_000_000;
-        assert!(
-            size_ok(actual, expected),
-            "we don't want these to grow unnoticed: {actual} <~ {expected}"
-        );
-    }
-}

gix-pack/src/cache/delta/tree.rs

@@ -226,7 +226,6 @@ mod tests {
         }
     }
 
-    // FIXME: Probably remove this pair of tests or the equivalent pair in `gix-pack/src/cache/delta/mod.rs`.
     mod size {
         use super::super::Item;
         use gix_testtools::size_ok;