Box arguments that are supposed to be boxed.

src/test/run-pass/generic-tag.rs

@@ -1,6 +1,6 @@
 type option[T] = tag(some(@T), none());
 
 fn main() {
-  let option[int] a = some[int](10);
+  let option[int] a = some[int](@10);
   a = none[int]();
 }

src/test/run-pass/list.rs

@@ -3,5 +3,5 @@
 type list = tag(cons(int,@list), nil());
 
 fn main() {
-  cons(10, cons(11, cons(12, nil())));
+  cons(10, @cons(11, @cons(12, @nil())));
 }

src/test/run-pass/mlist.rs

@@ -3,5 +3,5 @@
 type mlist = tag(cons(int,mutable @mlist), nil());
 
 fn main() {
-  cons(10, cons(11, cons(12, nil())));
+  cons(10, @cons(11, @cons(12, @nil())));
 }