By popular demand, print the configurations being tested by test.dart at startup.

tools/test-runtime.dart

 #!/usr/bin/env 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.
 
 // TODO(ager): Get rid of this version of test.dart when we don't have
 // to worry about the special runtime checkout anymore.
 // This file is identical to test.dart with test suites in the
 // directories samples, client, compiler, frog, and utils removed.
 
 #library("test");
 
 #import("testing/dart/test_runner.dart");
 #import("testing/dart/test_options.dart");
 
 #import("../tests/co19/test_config.dart");
 #import("../tests/corelib/test_config.dart");
 #import("../tests/isolate/test_config.dart");
 #import("../tests/language/test_config.dart");
 #import("../tests/standalone/test_config.dart");
 #import("../tests/utils/test_config.dart");
 #import("../runtime/tests/vm/test_config.dart");
 
 main() {
   var startTime = new Date.now();
   var optionsParser = new TestOptionsParser();
   List<Map> configurations = optionsParser.parse(new Options().arguments);
   if (configurations == null) return;
 
+  // Print the configurations being run by this excution of test.dart.
+  StringBuffer sb = new StringBuffer('Test configuration');
+  sb.add(configurations.length > 1 ? 's:' : ':');
+  for (Map conf in configurations) {
+    sb.add(' ${conf["component"]}_${conf["mode"]}_${conf["arch"]}');
+    if (conf['checked']) sb.add('_checked');
+  }
+  print(sb);
+
   // Extract global options from first configuration.
   var firstConf = configurations[0];
   Map<String, RegExp> selectors = firstConf['selectors'];
   var maxProcesses = firstConf['tasks'];
   var progressIndicator = firstConf['progress'];
   var verbose = firstConf['verbose'];
   var printTiming = firstConf['time'];
   var listTests = firstConf['list'];
   var keepGeneratedTests = firstConf['keep-generated-tests'];
 
@@ skipping 33 matching lines @@
   // Start process queue.
   var queue = new ProcessQueue(maxProcesses,
                                progressIndicator,
                                startTime,
                                printTiming,
                                enqueueConfiguration,
                                verbose,
                                listTests,
                                keepGeneratedTests);
 }