Correctly handle constness for list and map literals inside bodies.

lib/compiler/implementation/compile_time_constants.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class Constant implements Hashable {
   const Constant();
 
   bool isNull() => false;
   bool isBool() => false;
   bool isTrue() => false;
@@ skipping 692 matching lines @@
       arguments.add(evaluate(link.head));
     }
     // TODO(floitsch): get type from somewhere.
     Type type = null;
     Constant constant = new ListConstant(type, arguments);
     compiler.constantHandler.registerCompileTimeConstant(constant);
     return constant;
   }
 
   Constant visitLiteralMap(LiteralMap node) {
-    // TODO(floitsch): check for isConst, once the parser adds it into the node.
-    // if (!node.isConst()) error(node);
+    if (!node.isConst()) error(node);
     List<StringConstant> keys = <StringConstant>[];
     List<Constant> values = <Constant>[];
     bool hasProtoKey = false;
     for (Link<Node> link = node.entries.nodes;
          !link.isEmpty();
          link = link.tail) {
       LiteralMapEntry entry = link.head;
       Constant key = evaluate(entry.key);
       if (!key.isString() || entry.key.asLiteralString() === null) {
         MessageKind kind = MessageKind.KEY_NOT_A_STRING_LITERAL;
@@ skipping 381 matching lines @@
             fieldValue = compiler.compileVariable(member);
           }
           jsNewArguments.add(fieldValue);
         }
       }
       classElement = classElement.superclass;
     } 
     return jsNewArguments;
   }
 }