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

tests/compiler/dart2js/simple_inferrer_try_catch_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 '../../../sdk/lib/_internal/compiler/implementation/types/types.dart'
     show TypeMask;
 
 import 'compiler_helper.dart';
 
@@ skipping 136 matching lines @@
   returnDyn4();
   returnInt5();
   returnDyn5();
   returnInt6();
   returnDyn6();
 }
 """;
 
 
 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;
 
   checkReturn(String name, type) {
     var element = findElement(compiler, name);
     Expect.equals(type,
         typesInferrer.internal.returnTypeOf[element].simplify(compiler));
   }
 
   checkReturn('returnInt1', typesInferrer.intType);
   checkReturn('returnInt2', typesInferrer.intType);
   checkReturn('returnInt3', typesInferrer.intType);
   checkReturn('returnInt4', typesInferrer.intType);
   checkReturn('returnInt5', typesInferrer.intType);
   checkReturn('returnInt6',
       new TypeMask.nonNullSubtype(compiler.intClass.rawType));
 
   var subclassOfInterceptor =
       findTypeMask(compiler, 'Interceptor', 'nonNullSubclass');
 
   checkReturn('returnDyn1', subclassOfInterceptor);
   checkReturn('returnDyn2', subclassOfInterceptor);
   checkReturn('returnDyn3', subclassOfInterceptor);
   checkReturn('returnDyn4', subclassOfInterceptor);
   checkReturn('returnDyn5', subclassOfInterceptor);
   checkReturn('returnDyn6', typesInferrer.dynamicType);
 }