Miscellaneous cleanup

data/items/pocket_names.asm

@@ -1,9 +1,11 @@
 ItemPocketNames:
 ; entries correspond to item type constants
+	table_width 2, ItemPocketNames
 	dw .Item
 	dw .Key
 	dw .Ball
 	dw .TM
+	assert_table_length NUM_ITEM_TYPES
 
 .Item: db "ITEM POCKET@"
 .Key:  db "KEY POCKET@"