dart2js: run dartfmt on tests

tests/compiler/dart2js_extra/constant_javascript_semantics3_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.
 
 import "package:expect/expect.dart";
 
 // Make sure we use JavaScript semantics when compiling compile-time constants.
 // In this case we test that the value-range analysis uses JavaScript semantics
 // too.
 
@@ skipping 11 matching lines @@
   i += 1000000000000000;
   // [i] is now at its maximum 53 bit value. The following increments will not
   // have any effect.
   i++;
   i++;
   i++;
   i -= 1000000000000000;
   i--;
   i--;
   i--;
-  i -= 8007199254740992;   // In JS semantics [i] would be -3, now.
+  i -= 8007199254740992; // In JS semantics [i] would be -3, now.
   return a[i];
 }
 
 main() {
-  Expect.throws(() => foo(),
-                (e) => e is RangeError);
+  Expect.throws(() => foo(), (e) => e is RangeError);
 }