Format all tests.

tests/language_strong/assign_instance_method_negative_test.dart

 // Copyright (c) 2011, 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.
 
 class A {
   A() {}
-  imethod() { return 0; }
+  imethod() {
+    return 0;
+  }
 }
 
 main() {
   var a = new A();
   // Illegal, can't change a member method
-  a.imethod = () { return 1; };
+  a.imethod = () {
+    return 1;
+  };
 }