fixes #157, renaming local library identifiers if needed.

lib/runtime/dart/_interceptors.js

Index: lib/runtime/dart/_interceptors.js
diff --git a/lib/runtime/dart/_interceptors.js b/lib/runtime/dart/_interceptors.js
index 6ebafabd39c0d05a7371d866dd43a0a09020eb54..18afca88a19fc722712c9d850ac3f683998ea23d 100644
--- a/lib/runtime/dart/_interceptors.js
+++ b/lib/runtime/dart/_interceptors.js
@@ -1,5 +1,10 @@
-var _interceptors;
-(function(exports) {
+var _interceptors = dart.defineLibrary(_interceptors, {});
+var core = dart.lazyImport(core);
+var _js_helper = dart.import(_js_helper);
+var _internal = dart.lazyImport(_internal);
+var _foreign_helper = dart.lazyImport(_foreign_helper);
+var _js_embedded_names = dart.lazyImport(_js_embedded_names);
+(function(exports, core, _js_helper, _internal, _foreign_helper, _js_embedded_names) {
   'use strict';
   let JSArray = Array;
   let JSMutableArray$ = dart.generic(function(E) {
@@ -1086,4 +1091,4 @@ var _interceptors;
   exports.JavaScriptObject = JavaScriptObject;
   exports.PlainJavaScriptObject = PlainJavaScriptObject;
   exports.UnknownJavaScriptObject = UnknownJavaScriptObject;
-})(_interceptors || (_interceptors = {}));
+})(_interceptors, core, _js_helper, _internal, _foreign_helper, _js_embedded_names);