Add some [[maybe_unused]] tags for when asserts are disabled

src/road.cpp

@@ -836,7 +836,7 @@ static void PublicRoad_FoundEndNode(AyStar *aystar, OpenListNode *current)
 			// We only get here if we have a parent and we're not adjacent to it. River/Tunnel time!
 			const DiagDirection road_direction = DiagdirBetweenTiles(tile, path->parent->node.tile);
 
-			auto end_tile = INVALID_TILE;
+			[[maybe_unused]] auto end_tile = INVALID_TILE;
 
 			const Slope tile_slope = GetTileSlope(tile);
 			if (IsUpwardsSlope(tile_slope, road_direction)) {

src/tracerestrict_gui.cpp

@@ -3430,7 +3430,7 @@ private:
 	 * Show a drop down list using @p list_set, setting the pre-selected item to the one corresponding to @p value
 	 * This asserts if @p value is not in @p list_set, and @p missing_ok is false
 	 */
-	void ShowCompanyDropDownListWithValue(CompanyID value, bool missing_ok, int button)
+	void ShowCompanyDropDownListWithValue(CompanyID value, [[maybe_unused]] bool missing_ok, int button)
 	{
 		DropDownList list;
 

src/tunnel_map.cpp

@@ -49,7 +49,7 @@ Tunnel::~Tunnel()
 		tunnel_tile_index_map.erase(this->tile_s);
 	}
 
-	bool have_erased = false;
+	[[maybe_unused]] bool have_erased = false;
 	const auto key = GetTunnelAxisHeightCacheKey(this);
 	for (auto it = tunnel_axis_height_index.lower_bound(key); it != tunnel_axis_height_index.end() && it->first == key; ++it) {
 		if (it->second == this) {