added structure renderer.

src/main/java/carpet/script/CarpetScriptServer.java

@@ -43,6 +43,7 @@ public class CarpetScriptServer
 
     private static final List<Module> bundledModuleData = new ArrayList<Module>(){{
         add(new BundledModule("camera", false));
+        add(new BundledModule("structures", false));
         add(new BundledModule("event_test", false));
         add(new BundledModule("stats_test", false));
         add(new BundledModule("math", true));

src/main/java/carpet/script/Expression.java

@@ -1312,7 +1312,7 @@ public class Expression
             LazyValue boundedLHS;
             if (v1 instanceof ListValue || v1 instanceof MapValue)
             {
-                ((ListValue) v1).append(v2);
+                ((AbstractListValue) v1).append(v2);
                 boundedLHS = (cc, tt)-> v1;
             }
             else