test: Add missing #![feature(managed_boxes)]

The tests use managed boxes, but are not perfectly feature-gated because
they use `@` inside macros. (It causes issue after `--pretty expanded`.)

src/test/run-pass/assert-eq-macro-success.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(managed_boxes)]
+
 #[deriving(Eq, Show)]
 struct Point { x : int }
 

src/test/run-pass/binops.rs

@@ -10,6 +10,8 @@
 
 // Binop corner cases
 
+#![feature(managed_boxes)]
+
 fn test_nil() {
     assert_eq!((), ());
     assert!((!(() != ())));

src/test/run-pass/box-compare.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
+#![feature(managed_boxes)]
 
 pub fn main() {
     assert!((@1 < @3));

src/test/run-pass/ifmt.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 
-#![feature(macro_rules)]
+#![feature(macro_rules, managed_boxes)]
 #![deny(warnings)]
 #![allow(unused_must_use)]
 #![allow(deprecated_owned_vector)]

src/test/run-pass/nullable-pointer-iotareduction.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(macro_rules)]
+#![feature(macro_rules, managed_boxes)]
 
 use std::{option, mem};
 

src/test/run-pass/nullable-pointer-size.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(macro_rules)]
+#![feature(macro_rules, managed_boxes)]
 
 use std::mem;