Use --use-cps-ir compiler option in the test script to run dart2js with the new backend.

tools/bots/compiler.py

 #!/usr/bin/python
 
 # 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.
 
 """
 Dart2js buildbot steps
 
 Runs tests for the  dart2js compiler.
@@ skipping 341 matching lines @@
       [os.environ['PATH'], tools_dir, platform_tools_dir])
 
 def RunCompilerTests(build_info):
   test_flags = []
   if build_info.shard_index:
     test_flags = ['--shards=%s' % build_info.total_shards,
                   '--shard=%s' % build_info.shard_index]
   if build_info.checked: test_flags += ['--checked']
   if build_info.minified: test_flags += ['--minified']
   if build_info.host_checked: test_flags += ['--host-checked']
-  # cps backend does not work with batch mode due to the environment variable
-  # setting.
-  if build_info.batch and not build_info.cps_ir:
-    test_flags += ['--dart2js-batch']
+  if build_info.batch: test_flags += ['--dart2js-batch']
   if build_info.builder_tag: test_flags += ['--builder-tag=' +
                                              build_info.builder_tag]
   if build_info.cps_ir: test_flags += ['--cps-ir']
 
   if build_info.dart2js_full:
     compiler = build_info.compiler
     assert compiler == 'dart2js'
     system = build_info.system
     arch = build_info.arch
     mode = build_info.mode
@@ skipping 39 matching lines @@
     if build_info.mode == 'debug':
       target = 'dart2js_bot_debug'
     args = [sys.executable, './tools/build.py', '--mode=' + build_info.mode,
             '--arch=' + build_info.arch, target]
     print 'Build SDK and d8: %s' % (' '.join(args))
     bot.RunProcess(args)
 
 
 if __name__ == '__main__':
   bot.RunBot(GetBuildInfo, RunCompilerTests, build_step=BuildCompiler)