add comments

[jeffwashington]

Problem

Summary of Changes

Fixes #

[brooksprumo]

Looks like this comment pertains the new version, found here:

solana/runtime/src/in_mem_accounts_index.rs

Lines 441 to 451 in d525ef3

	/// Try to update an item in the slot list the given `slot` If an item for the slot
	/// already exists in the list, remove the older item, add it to `reclaims`, and insert
	/// the new item.
	/// if 'other_slot' is some, then also remove any entries in the slot list that are at 'other_slot'
	pub fn lock_and_update_slot_list(
	current: &AccountMapEntryInner<T>,
	new_value: (Slot, T),
	other_slot: Option<Slot>,
	reclaims: &mut SlotList<T>,
	previous_slot_entry_was_cached: bool,
	) {

But not this version of the fn. Dunno how you'd like to handle it for this PR though. Wdyt?

[jeffwashington]

fixed it

[brooksprumo]

Love it!