fixes #157, renaming local library identifiers if needed.

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 476038365eaffe0e29928ddd821384372f5ee673..55d93429d0cf1f115fd5c3a95b8020c5c96b1d8e 100644
--- a/lib/runtime/dart/core.js
+++ b/lib/runtime/dart/core.js
@@ -1,5 +1,10 @@
-var core;
-(function(exports) {
+var core = dart.defineLibrary(core, {});
+var _js_helper = dart.import(_js_helper);
+var _internal = dart.import(_internal);
+var collection = dart.import(collection);
+var _interceptors = dart.import(_interceptors);
+var convert = dart.import(convert);
+(function(exports, _js_helper, _internal, collection, _interceptors, convert) {
   'use strict';
   class Object {
     constructor() {
@@ -2504,7 +2509,7 @@ var core;
     get pathSegments() {
       if (this[_pathSegments] == null) {
         let pathToSplit = !dart.notNull(this.path.isEmpty) && this.path.codeUnitAt(0) == Uri._SLASH ? this.path.substring(1) : this.path;
-        this[_pathSegments] = new (collection.UnmodifiableListView$(String))(pathToSplit == "" ? dart.const(dart.setType([], List$(String))) : new List$(String).from(pathToSplit.split("/")[$map](dart.bind(Uri, 'decodeComponent')), {growable: false}));
+        this[_pathSegments] = new (collection.UnmodifiableListView$(String))(pathToSplit == "" ? dart.const(dart.setType([], List$(String))) : new (List$(String)).from(pathToSplit.split("/")[$map](dart.bind(Uri, 'decodeComponent')), {growable: false}));
       }
       return this[_pathSegments];
     }
@@ -3486,4 +3491,4 @@ var core;
   exports.Type = Type;
   exports.Uri = Uri;
   exports.SupportJsExtensionMethods = SupportJsExtensionMethods;
-})(core || (core = {}));
+})(core, _js_helper, _internal, collection, _interceptors, convert);