Added support for skipping redundant dart2js compilations.

tests/standalone/io/test_runner_exit_code_script.dart

Index: tests/standalone/io/test_runner_exit_code_script.dart
diff --git a/tests/standalone/io/test_runner_exit_code_script.dart b/tests/standalone/io/test_runner_exit_code_script.dart
index f137022cf2056340ae79dc398f5e401f4771e5b8..94267a704600f8acf45df1dbf60b486ff2e985cf 100644
--- a/tests/standalone/io/test_runner_exit_code_script.dart
+++ b/tests/standalone/io/test_runner_exit_code_script.dart
@@ -28,7 +28,7 @@ main() {
   progress.allTestsKnown();
   progress.start(testCase);
   new CommandOutput.fromCase(testCase, dummyCommand, 1, false, false, [], [],
-                             new Date.now().difference(startTime));
+                             new Date.now().difference(startTime), false);
   progress.done(testCase);
   progress.allDone();
 }