Start supporting fixed length and immutable lists.

dart/frog/leg/emitter.dart

Index: dart/frog/leg/emitter.dart
diff --git a/dart/frog/leg/emitter.dart b/dart/frog/leg/emitter.dart
index f76b68ec196c99e7dc842bb25831f9e5820e096e..5d00bcd4f138434a56deac12f40a90bbb5691ca1 100644
--- a/dart/frog/leg/emitter.dart
+++ b/dart/frog/leg/emitter.dart
@@ -526,6 +526,7 @@ $prototype.toString = function() {
     CompileTimeConstantHandler handler = compiler.compileTimeConstantHandler;
     List<Constant> constants = handler.getConstantsForEmission();
     String prototype = "${namer.ISOLATE}.prototype";
+    emitMakeConstantList(prototype, buffer);
     for (Constant constant in constants) {
       String name = handler.getNameForConstant(constant);
       buffer.add('$prototype.$name = ');
@@ -534,6 +535,16 @@ $prototype.toString = function() {
     }
   }
 
+  void emitMakeConstantList(String prototype, StringBuffer buffer) {
+    buffer.add(prototype);
+    buffer.add(@'''.makeConstantList = function(list) {
+  list.immutable$list = true;
+  list.fixed$length = true;
+  return list;
+};
+''');
+  }
+
   void emitStaticFinalFieldInitializations(StringBuffer buffer) {
     CompileTimeConstantHandler constants = compiler.compileTimeConstantHandler;
     List<VariableElement> staticFinalFields =