Fix negative test by not complicating it by using the unit test framework.

tests/isolate/isolate2_negative_test.dart

Index: tests/isolate/isolate2_negative_test.dart
diff --git a/tests/isolate/isolate2_negative_test.dart b/tests/isolate/isolate2_negative_test.dart
index 587d53036361bd9dda10725de59cc1caa25796b2..11d66ed7411f6c1968d8e120b1285ea4d609ef9e 100644
--- a/tests/isolate/isolate2_negative_test.dart
+++ b/tests/isolate/isolate2_negative_test.dart
@@ -7,14 +7,11 @@
 
 #library('Isolate2NegativeTest');
 #import('dart:isolate');
-#import('../../lib/unittest/unittest.dart');
 
 void entry() {
   throw "foo";
 }
 
 main() {
-  test("catch exception from other isolate", () {
-    spawnFunction(entry);
-  });
+  SendPort port = spawnFunction(entry);
 }