Shard dart2js unit tests as well.

dart/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 201 matching lines @@
     try:
       print 'Version of %s: %s' % (runtime, output[-1])
     except IndexError:
       # Failed to obtain version information. Continue running tests.
       pass
 
   if runtime == 'd8':
     # The dart2js compiler isn't self-hosted (yet) so we run its
     # unit tests on the VM. We avoid doing this on the builders
     # that run the browser tests to cut down on the cycle time.
+    unit_test_flags = [flag for flag in flags if flag.startswith('--shard')]
+    # Run the unit tests in checked mode (the VM's checked mode).

[ricow1, 2013/05/21 10:26:24]

We already do this on the checked mode bots, why not remove this? (i.e., we pass
in the --checked flag twice on the checked mode bots and once on the regular
bots)

[ahe, 2013/05/21 11:41:33]

We are not passing the "--checked" flag twice.  All flags but the shard flags
are being removed on line 222.

These are dart2js *unit* tests, and they are not being compiled with dart2js. 
Instead they are running directly on the Dart VM, and we should not be passing
dart2js flags to the Dart VM.

[kustermann, 2013/05/21 11:44:57]

In addition to that, test_options.dart will throw if we pass the same flag
multiple times AFAIK.

+    unit_test_flags.append('--checked')
     TestStep("dart2js_unit", mode, system, 'none', 'vm', ['dart2js'],
-             # Run the unit tests in checked mode (the VM's checked mode).
-             ['--checked'])
+             unit_test_flags)
 
   if system.startswith('win') and runtime.startswith('ie10'):
     TestStep("dart2js", mode, system, 'dart2js', runtime, ['html'], flags)
   else:
     # Run the default set of test suites.
     TestStep("dart2js", mode, system, 'dart2js', runtime, [], flags)
 
     # TODO(kasperl): Consider running peg and css tests too.
     extras = ['dart2js_extra', 'dart2js_native', 'dart2js_foreign']
     extras_flags = flags
@@ skipping 95 matching lines @@
   """
   with bot.BuildStep('Build SDK and d8'):
     args = [sys.executable, './tools/build.py', '--mode=' + build_info.mode,
             'dart2js_bot']
     print 'Build SDK and d8: %s' % (' '.join(args))
     bot.RunProcess(args)
 
 
 if __name__ == '__main__':
   bot.RunBot(GetBuildInfo, RunCompilerTests, build_step=BuildCompiler)