Make stack frames without columns print correctly.

pkg/stack_trace/test/frame_test.dart

Index: pkg/stack_trace/test/frame_test.dart
diff --git a/pkg/stack_trace/test/frame_test.dart b/pkg/stack_trace/test/frame_test.dart
index 62cfd2ee0a2b1b8c0ec997ca1c26fecdb42841bb..86b6df463fd3698b7a838e888087170c6e03684c 100644
--- a/pkg/stack_trace/test/frame_test.dart
+++ b/pkg/stack_trace/test/frame_test.dart
@@ -321,5 +321,10 @@ void main() {
               '(dart:core/uri.dart:5:10)').toString(),
           equals('dart:core/uri.dart 5:10 in Foo.<fn>'));
     });
+
+    test('prints a frame without a column correctly', () {
+      expect(new Frame.parseVM('#0 Foo (dart:core/uri.dart:5)').toString(),
+          equals('dart:core/uri.dart 5 in Foo.<fn>'));
+    });
   });
 }