Correctly handle constness for list and map literals inside bodies.

lib/compiler/implementation/tree/unparser.dart

Index: lib/compiler/implementation/tree/unparser.dart
diff --git a/lib/compiler/implementation/tree/unparser.dart b/lib/compiler/implementation/tree/unparser.dart
index f831c1a6139547cec7394faf5b16fe5e4ade2d27..83f32bd714e4ae95b755a9760e35d25e955c5c4a 100644
--- a/lib/compiler/implementation/tree/unparser.dart
+++ b/lib/compiler/implementation/tree/unparser.dart
@@ -130,12 +130,14 @@ class Unparser implements Visitor {
   }
 
   visitNewExpression(NewExpression node) {
+    // TODO(ahe): handle 'const'.
     add(node.newToken.value);
     sb.add(' ');
     visit(node.send);
   }
 
   visitLiteralList(LiteralList node) {
+    // TODO(ahe): handle 'const'.
     if (node.type !== null) {
       sb.add('<');
       visit(node.type);
@@ -305,6 +307,7 @@ class Unparser implements Visitor {
   }
 
   visitLiteralMap(LiteralMap node) {
+    // TODO(ahe): handle 'const'.
     if (node.typeArguments !== null) visit(node.typeArguments);
     visit(node.entries);
   }