(svn r20909) -Fix [FS#4137]: don't see coasts as water for object construction

src/water_map.h

@@ -170,6 +170,16 @@ static inline bool IsCoast(TileIndex t)
 	return GetWaterTileType(t) == WATER_TILE_COAST;
 }
 
+/**
+ * Is it a coast tile
+ * @param t Tile to query.
+ * @return \c true if it is a coast.
+ */
+static inline bool IsCoastTile(TileIndex t)
+{
+	return IsTileType(t, MP_WATER) && IsCoast(t);
+}
+
 /**
  * Get the other tile of the ship depot.
  * @param t Tile to query, containing one section of a ship depot.