Remove unused task_exit function

Issue #236

Author: brson

src/rt/rust_task.cpp

@@ -137,18 +137,6 @@ struct rust_closure_env {
     type_desc *td;
 };
 
-extern "C" CDECL
-void task_exit(rust_closure_env *env, int rval, rust_task *task) {
-    LOG(task, task, "task exited with value %d", rval);
-    if(env) {
-        // free the environment.
-        I(task->sched, 1 == env->ref_count); // the ref count better be 1
-        //env->td->drop_glue(NULL, task, NULL, env->td->first_param, env);
-        //env->td->free_glue(NULL, task, NULL, env->td->first_param, env);
-        task->free(env);
-    }
-}
-
 extern "C" CDECL
 void task_start_wrapper(spawn_args *a)
 {