Forward cancel subscription in stream pipes.

tests/language/async_star_regression_fisk_test.dart

Index: tests/language/async_star_regression_fisk_test.dart
diff --git a/tests/language/async_star_regression_fisk_test.dart b/tests/language/async_star_regression_fisk_test.dart
index b05356a9fac9c0f0b927ddf9e7ade850cf4a34f2..b46d90faa1fe5d37d899d95b293caf7671e32805 100644
--- a/tests/language/async_star_regression_fisk_test.dart
+++ b/tests/language/async_star_regression_fisk_test.dart
@@ -34,10 +34,11 @@ main() {
   fugl(3).whenComplete(() => fugl(2))
       .whenComplete(() => fugl(1))
       .whenComplete(() {
-    Expect.listEquals(res,
+    Expect.listEquals(
         ["fisk 3", "+fisk", 0, 1, "-fisk", "done",
          "fisk 2", "+fisk", 0, 1, "-fisk", "done",
-         "fisk 1", "+fisk", 0, "done", "-fisk", ]);
+         "fisk 1", "+fisk", 0, "-fisk", "done"],
+        res);
     asyncEnd();
   });
 }