Fix Array constructor bug impacting dart2js and ddc running on the same page.

lib/runtime/dart/core.js

Index: lib/runtime/dart/core.js
diff --git a/lib/runtime/dart/core.js b/lib/runtime/dart/core.js
index ca2fcc00161a98016bfe5d442416db0a8edb1ee3..5a6d0f1bf7caf80b6b1379c790065744d19378d0 100644
--- a/lib/runtime/dart/core.js
+++ b/lib/runtime/dart/core.js
@@ -1616,7 +1616,7 @@ var core;
     return List;
   });
   let List = List$();
-  dart.copyProperties(dart.global.Array.prototype, List.prototype);
+  dart.copyPropertySymbols(dart.global.Array.prototype, List.prototype);

[Jennifer Messerly, 2015/04/23 19:33:53]

dart.registerExtension(dart.global.Array, List)?

we might need this for the dynamic ops too. Seems nice to express the intent
here, rather than specifically how to implement it?

   let Map$ = dart.generic(function(K, V) {
     class Map extends Object {
       Map() {