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

tests/compiler/dart2js/concrete_type_inference_test.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.
 
 import "package:expect/expect.dart";
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
 
 void compileAndFind(String code, String name,
                     check(compiler, element)) {
-  Uri uri = new Uri.fromComponents(scheme: 'source');
+  Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(code, uri);
   compiler.runCompiler(uri);
   var element = findElement(compiler, name);
   return check(compiler, element);
 }
 
 void checkPrintType(String expression, checkType(compiler, type)) {
   compileAndFind(
       'main() { print($expression); }',
       'print',
@@ skipping 74 matching lines @@
         Expect.identical(
             inferrer.nullType,
             typesTask.getGuaranteedTypeOfElement(thirdParameter));
       });
 }
 
 void main() {
   testBasicTypes();
   testOptionalParameters();
 }