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

tests/compiler/dart2js/simple_inferrer_postfix_prefix_test.dart

 // Copyright (c) 2013, 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';
 
 const String TEST = """
 
@@ skipping 43 matching lines @@
   new B()..returnString1()
          ..returnString2()
          ..returnDynamic1()
          ..returnDynamic2()
          ..returnDynamic3()
          ..returnDynamic4();
 }
 """;
 
 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;
 
   checkReturnInClass(String className, String methodName, type) {
     var cls = findElement(compiler, className);
     var element = cls.lookupLocalMember(buildSourceString(methodName));
     Expect.equals(type,
         typesInferrer.internal.returnTypeOf[element].simplify(compiler));
   }
@@ skipping 11 matching lines @@
   checkReturnInClass('A', 'returnDynamic2', subclassOfInterceptor);
   checkReturnInClass('A', 'returnDynamic3', typesInferrer.dynamicType);
 
   checkReturnInClass('B', 'returnString1', typesInferrer.stringType);
   checkReturnInClass('B', 'returnString2', typesInferrer.stringType);
   checkReturnInClass('B', 'returnDynamic1', typesInferrer.dynamicType);
   checkReturnInClass('B', 'returnDynamic2', typesInferrer.dynamicType);
   checkReturnInClass('B', 'returnDynamic3', typesInferrer.dynamicType);
   checkReturnInClass('B', 'returnDynamic4', typesInferrer.dynamicType);
 }