Improve scheduler auto outline

A few small tweaks to the scheduler

1. Allow devices to be applied to all functions at once (e.g., host(*);)
2. Allow auto-outline to be run on a selection of functions, instead of the entire module, and change the return to be labeled by the name of the function outlined from

juno_samples/schedule_test/src/sched.sch

@@ -40,5 +40,8 @@ fixpoint panic after 2 {
   phi-elim(*);
 }
 
+host(*);
+cpu(first, second);
+
 codegen-prep!(*);
 //xdot[true](*);