Add --verify-ir flag to dartk and test.py.

pkg/kernel/test/check_bench.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.
-
-import 'dart:io';
-import 'package:kernel/checks.dart';
-import 'package:kernel/kernel.dart';
-
-final String usage = '''
-Usage: check_bench FILE.dill
-
-Measures the time it takes to run sanity checks on the given program.
-''';
-
-main(List<String> args) {
-  if (args.length != 1) {
-    print(usage);
-    exit(1);
-  }
-  var program = loadProgramFromBinary(args[0]);
-  var watch = new Stopwatch()..start();
-  runSanityChecks(program);
-  print('Cold: ${watch.elapsedMilliseconds} ms');
-  const int warmUpTrials = 20;
-  for (int i = 0; i < warmUpTrials; ++i) {
-    runSanityChecks(program);
-  }
-  watch.reset();
-  const int numberOfTrials = 100;
-  for (int i = 0; i < numberOfTrials; ++i) {
-    runSanityChecks(program);
-  }
-  double millisecondsPerRun = watch.elapsedMilliseconds / numberOfTrials;
-  print('Hot:  $millisecondsPerRun ms');
-}