Use RefCount type alias instead of u64 (#26472)

use RefCount type alias instead of u64

bucket_map/src/bucket.rs

@@ -240,7 +240,7 @@ impl<T: Clone + Copy> Bucket<T> {
         &mut self,
         key: &Pubkey,
         data: &[T],
-        ref_count: u64,
+        ref_count: RefCount,
     ) -> Result<(), BucketMapError> {
         let best_fit_bucket = IndexEntry::data_bucket_from_num_slots(data.len() as u64);
         if self.data.get(best_fit_bucket as usize).is_none() {

runtime/src/accounts_db.rs

@@ -2204,7 +2204,7 @@ impl AccountsDb {
     }
 
     fn calc_delete_dependencies(
-        purges: &HashMap<Pubkey, (SlotList<AccountInfo>, u64)>,
+        purges: &HashMap<Pubkey, (SlotList<AccountInfo>, RefCount)>,
         store_counts: &mut HashMap<AppendVecId, (usize, HashSet<Pubkey>)>,
     ) {
         // Another pass to check if there are some filtered accounts which
@@ -2212,7 +2212,7 @@ impl AccountsDb {
         // then increment their storage count.
         let mut already_counted = HashSet::new();
         for (pubkey, (account_infos, ref_count_from_storage)) in purges.iter() {
-            let no_delete = if account_infos.len() as u64 != *ref_count_from_storage {
+            let no_delete = if account_infos.len() as RefCount != *ref_count_from_storage {
                 debug!(
                     "calc_delete_dependencies(),
                     pubkey: {},