enable --dump-info with the --fast-startup emitter

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 6819491d334fc8d445a5121137a4468d997670c3..2033f8271b39186646435ec2b7acf465c7f062e9 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -230,11 +230,6 @@ abstract class Compiler implements LibraryLoaderListener {
     }
     enqueuer = backend.makeEnqueuer();
 
-    if (options.dumpInfo && options.useStartupEmitter) {
-      throw new ArgumentError(
-          '--dump-info is not supported with the fast startup emitter');
-    }
-
     tasks = [
       dietParser = new DietParserTask(idGenerator, backend, reporter, measurer),
       scanner = createScannerTask(),