Re-land "Format all multitests"

tests/language/compile_time_constant_r_test.dart

 // Copyright (c) 2014, 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.
 
 const x =
           throw // //# 01: compile-time error
-          "x";
+    "x";
 
-const y = const {0:
+const y = const {
+  0:
                     throw // //# 02: compile-time error
-                    "y"};
+      "y"
+};
 
 main() {
   print(x);
   print(y);
   const z =
             throw // //# 03: compile-time error
-            1+1+1;
+      1 + 1 + 1;
   print(z);
 }