Fix blockstore_processor::load_frozen_forks() halt_at_slot behavior II (#28367)

PR #28317 previously attempted to fix a case where blockstore processing
would create children banks for slots past the halt_at_slot.

However, the previous fix didn't handle the case where a slot could be
strictly less than the halt_at_slot, but have children that were greater
than the halt_at_slot. For example, this could happen if a child of slot
S is S+n where n > 1.

Thus, this change covers our processing logic to cover this second case
as well.

ledger/src/blockstore_processor.rs

@@ -1360,6 +1360,7 @@ fn process_next_slots(
     blockstore: &Blockstore,
     leader_schedule_cache: &LeaderScheduleCache,
     pending_slots: &mut Vec<(SlotMeta, Bank, Hash)>,
+    halt_at_slot: Option<Slot>,
 ) -> result::Result<(), BlockstoreProcessorError> {
     if meta.next_slots.is_empty() {
         return Ok(());
@@ -1367,6 +1368,13 @@ fn process_next_slots(
 
     // This is a fork point if there are multiple children, create a new child bank for each fork
     for next_slot in &meta.next_slots {
+        let skip_next_slot = halt_at_slot
+            .map(|halt_at_slot| *next_slot > halt_at_slot)
+            .unwrap_or(false);
+        if skip_next_slot {
+            continue;
+        }
+
         let next_meta = blockstore
             .meta(*next_slot)
             .map_err(|err| {
@@ -1438,6 +1446,7 @@ fn load_frozen_forks(
         blockstore,
         leader_schedule_cache,
         &mut pending_slots,
+        opts.halt_at_slot,
     )?;
 
     let on_halt_store_hash_raw_data_for_debug = opts.on_halt_store_hash_raw_data_for_debug;
@@ -1604,6 +1613,7 @@ fn load_frozen_forks(
                 blockstore,
                 leader_schedule_cache,
                 &mut pending_slots,
+                opts.halt_at_slot,
             )?;
         }
     } else if on_halt_store_hash_raw_data_for_debug {