Add constructors for JSArray

tests/compiler/dart2js/mock_compiler.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.
 
 library mock_compiler;
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:collection';
 
@@ skipping 84 matching lines @@
     toString() {}
     bool operator==(other) => identical(this, other);
     get hashCode => throw "Interceptor.hashCode not implemented.";
     noSuchMethod(im) { throw im; }
   }
   abstract class JSIndexable {
     get length;
     operator[](index);
   }
   abstract class JSMutableIndexable extends JSIndexable {}
-  class JSArray extends Interceptor implements List, JSIndexable {
+  class JSArray<E> extends Interceptor implements List<E>, JSIndexable {
+    JSArray();
+    factory JSArray.typed(a) => a;
     var length;
     operator[](index) => this[index];
     operator[]=(index, value) { this[index] = value; }
     add(value) { this[length + 1] = value; }
     removeAt(index) {}
     insert(index, value) {}
     removeLast() {}
   }
   class JSMutableArray extends JSArray implements JSMutableIndexable {}
   class JSFixedArray extends JSMutableArray {}
@@ skipping 388 matching lines @@
     } else {
       sourceFile = compiler.sourceFiles[uri.toString()];
     }
     if (sourceFile != null && begin != null && end != null) {
       print(sourceFile.getLocationMessage(message, begin, end, true, (x) => x));
     } else {
       print(message);
     }
   };
 }