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

pkg/analyzer_experimental/lib/src/generated/java_io.dart

 library java.io;
 
 import "dart:io";
-import "dart:uri";
 
 class JavaSystemIO {
   static Map<String, String> _properties = new Map();
   static String getProperty(String name) {
     {
       String value = _properties[name];
       if (value != null) {
         return value;
       }
     }
@@ skipping 62 matching lines @@
       return true;
     }
     if (_newDirectory().existsSync()) {
       return true;
     }
     return false;
   }
   bool isDirectory() {
     return _newDirectory().existsSync();
   }
-  Uri toURI() => new Uri.fromComponents(path: _path.toString());
+  Uri toURI() => new Uri(path: _path.toString());
   String readAsStringSync() => _newFile().readAsStringSync();
   int lastModified() => _newFile().lastModifiedSync().millisecondsSinceEpoch;
   File _newFile() => new File.fromPath(_path);
   Directory _newDirectory() => new Directory.fromPath(_path);
 }