Merge the dart:uri library into dart:core and update the Uri class

tests/compiler/dart2js/simple_inferrer_final_field3_test.dart

Index: tests/compiler/dart2js/simple_inferrer_final_field3_test.dart
diff --git a/tests/compiler/dart2js/simple_inferrer_final_field3_test.dart b/tests/compiler/dart2js/simple_inferrer_final_field3_test.dart
index b43693e6dc365c76e1f58f49fe9e4bece1f03a65..058187bfb70857ef71f0743571be10cc3246f843 100644
--- a/tests/compiler/dart2js/simple_inferrer_final_field3_test.dart
+++ b/tests/compiler/dart2js/simple_inferrer_final_field3_test.dart
@@ -23,7 +23,7 @@ main() {
 """;
 
 void main() {
-  Uri uri = new Uri.fromComponents(scheme: 'source');
+  Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
   compiler.runCompiler(uri);
   var typesInferrer = compiler.typesTask.typesInferrer;