Ignore another test that fails mysteriously on BSD

Author: brson

Diff for: src/test/run-pass/class-cast-to-trait.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-test FIXME fails on BSD
+
 #[feature(managed_boxes)];
 
 trait noisy {