signal to upsert whether reclaims are important (#18900)

* signal to upsert whether reclaims are important

* reclaims_must_be_empty -> previous_slot_entry_was_cached

* UPSERT_RECLAIMS_MUST_BE_EMPTY_FALSE -> UPSERT_PREVIOUS_SLOT_ENTRY_WAS_CACHED_FALSE

runtime/benches/accounts_index.rs

@@ -29,6 +29,7 @@ fn bench_accounts_index(bencher: &mut Bencher) {
                 &AccountSecondaryIndexes::default(),
                 AccountInfo::default(),
                 &mut reclaims,
+                false,
             );
         }
     }
@@ -46,6 +47,7 @@ fn bench_accounts_index(bencher: &mut Bencher) {
                 &AccountSecondaryIndexes::default(),
                 AccountInfo::default(),
                 &mut reclaims,
+                false,
             );
             reclaims.clear();
         }