mark _unused fields as such, don't bind unused vars in match

src/town.rs

@@ -15,14 +15,14 @@ enum Behavior {
 #[derive(Clone, Copy)]
 pub struct Town {
   map: Chunk,
-  npc_tile1: [Tile; 32],
-  npc_x1: [u8; 32],
-  npc_y1: [u8; 32],
-  npc_tile2: [Tile; 32],
-  npc_x2: [u8; 32],
-  npc_y2: [u8; 32],
-  npc_behavior: [Behavior; 32],
-  npc_talk_idx: [u8; 32],
+  _npc_tile1: [Tile; 32],
+  _npc_x1: [u8; 32],
+  _npc_y1: [u8; 32],
+  _npc_tile2: [Tile; 32],
+  _npc_x2: [u8; 32],
+  _npc_y2: [u8; 32],
+  _npc_behavior: [Behavior; 32],
+  _npc_talk_idx: [u8; 32],
 }
 
 impl HasMap for Town {