Re-land "Format all multitests"

tests/language_strong/duplicate_implements_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.
 // Check that duplicate types in implements/extends list are
 // compile-time errors.
 
-abstract class I { }
-abstract class J { }
-abstract class K<T> { }
+abstract class I {}
+
+abstract class J {}
+
+abstract class K<T> {}
 
 class X implements I, J, I { } //              //# 01: compile-time error
 class X implements J, I, K<int>, K<int> { } // //# 02: compile-time error
 
 abstract class Z implements I, J, J { } //             //# 03: compile-time error
 abstract class Z implements K<int>, K<int> { } //      //# 04: compile-time error
 
 main() {
   X x = new X(); // //# 01: continued
   X x = new X(); // //# 02: continued
   Z z = new Z(); // //# 03: continued
   Z z = new Z(); // //# 04: continued
 }