SPIGOT-2270: Retain Java 6 compat

nms-patches/ChunkProviderServer.patch

@@ -14,7 +14,7 @@
  
      private static final Logger a = LogManager.getLogger();
 -    private final Set<Long> unloadQueue = Sets.newHashSet();
-+    public final it.unimi.dsi.fastutil.longs.LongSet unloadQueue = new it.unimi.dsi.fastutil.longs.LongArraySet(); // CraftBukkit Set -> LongSet
++    public final Set<Long> unloadQueue = Sets.newHashSet(); // PAIL: private -> public
      public final ChunkGenerator chunkGenerator;
      private final IChunkLoader chunkLoader;
      public final Long2ObjectMap<Chunk> chunks = new Long2ObjectOpenHashMap(8192);