Remove unnecessary unwind messages

Now that the type_id intrinsic is working across crates, all of these
unnecessary messages can be removed to have the failure type for a task truly be
~Any and only ~Any

src/libstd/task/spawn.rs

@@ -83,11 +83,11 @@ use local_data;
 use rt::local::Local;
 use rt::sched::{Scheduler, Shutdown, TaskFromFriend};
 use rt::task::{Task, Sched};
-use rt::task::{UnwindMessageLinked, UnwindMessageStrStatic};
 use rt::task::{UnwindResult, Success, Failure};
 use rt::thread::Thread;
 use rt::work_queue::WorkQueue;
 use rt::{in_green_task_context, new_event_loop, KillHandle};
+use task::LinkedFailure;
 use task::SingleThreaded;
 use task::TaskOpts;
 use task::unkillable;
@@ -324,7 +324,7 @@ impl Drop for Taskgroup {
         do RuntimeGlue::with_task_handle_and_failing |me, failing| {
             if failing {
                 for x in self.notifier.mut_iter() {
-                    x.task_result = Some(Failure(UnwindMessageLinked));
+                    x.task_result = Some(Failure(~LinkedFailure as ~Any));
                 }
                 // Take everybody down with us. After this point, every
                 // other task in the group will see 'tg' as none, which
@@ -379,7 +379,7 @@ impl AutoNotify {
             notify_chan: chan,
 
             // Un-set above when taskgroup successfully made.
-            task_result: Some(Failure(UnwindMessageStrStatic("AutoNotify::new()")))
+            task_result: Some(Failure(~("AutoNotify::new()") as ~Any))
         }
     }
 }