Change: Make ScriptTile::IsBuildableRectangle use a TileArea for iteration

src/script/api/script_tile.cpp

@@ -50,13 +50,8 @@
 	/* Check whether we can extract valid X and Y */
 	if (!::IsValidTile(tile) || width < 1 || height < 1) return false;
 
-	uint tx = ScriptMap::GetTileX(tile);
-	uint ty = ScriptMap::GetTileY(tile);
-
-	for (uint x = tx; x < width + tx; x++) {
-		for (uint y = ty; y < height + ty; y++) {
-			if (!IsBuildable(ScriptMap::GetTileIndex(x, y))) return false;
-		}
+	for (auto cur_tile : TileArea(tile, width, height)) {
+		if (!IsBuildable(cur_tile)) return false;
 	}
 
 	return true;