Compute the correct signature for default constructors.

dart/tests/language/crash_12118_test.dart

Index: dart/tests/language/crash_12118_test.dart
diff --git a/dart/samples/tests/samples/browser/hi_test.dart b/dart/tests/language/crash_12118_test.dart
similarity index 54%
copy from dart/samples/tests/samples/browser/hi_test.dart
copy to dart/tests/language/crash_12118_test.dart
index 111797989253b6d72139ba36035872e9c3e54338..fea6996b338a21202bfd9d7197d1ea354b44a12b 100644
--- a/dart/samples/tests/samples/browser/hi_test.dart
+++ b/dart/tests/language/crash_12118_test.dart
@@ -2,16 +2,19 @@
 // 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.
 
-library hi_test;
+// Regression test for issue 12118 which caused a crash in dart2js.
 
-import '../../../hi/hi.dart' as hi;
+const X = 42;
 
-// @static-clean
+class A {
+  final x;
+  A({this.x: X});
+}
+
+class B extends A {}
 
-/**
- * This test exists to ensure that the hi sample compiles without errors.
- */
 void main() {
-  
+  if (new B().x != 42) {
+    throw 'Test failed';
+  }
 }
-