Handle const constructor invocation in kernel_impact.

tests/compiler/dart2js/kernel/visitor_test.dart

 // Copyright (c) 2016, 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.
 
 /// Test that the dart2js copy of [KernelVisitor] generates the expected IR as
 /// defined by kernel spec-mode test files.
 
 import 'dart:io';
 import 'package:compiler/src/compiler.dart' show Compiler;
 import 'package:compiler/src/elements/elements.dart';
@@ skipping 23 matching lines @@
         if (arguments.isNotEmpty) continue;
         if (SKIP_TESTS.contains(name)) continue;
       }
 
       test(name, () async {
         LibraryElement library = await compiler.analyzeUri(file.absolute.uri);
         JavaScriptBackend backend = compiler.backend;
         StringBuffer buffer = new StringBuffer();
         Program program = backend.kernelTask.buildProgram(library);
         new MixinFullResolution().transform(program);
-        new Printer(buffer).writeLibraryFile(
-            program.mainMethod.enclosingLibrary);
+        new Printer(buffer)
+            .writeLibraryFile(program.mainMethod.enclosingLibrary);
         String actual = buffer.toString();
         String expected =
             new File('${TESTCASE_DIR}/spec-mode/$name.baseline.txt')
                 .readAsStringSync();
         if (selected) {
           String input =
               new File('${TESTCASE_DIR}/input/$name.dart').readAsStringSync();
           print('============================================================');
           print(name);
           print('--input-----------------------------------------------------');
           print(input);
           print('--expected--------------------------------------------------');
           print(expected);
           print('--actual----------------------------------------------------');
           print(actual);
         }
         expect(actual, equals(expected));
       });
     }
   }
 }