Fn for Arc/Rc - fix build errors

Author: Centril

src/liballoc/arc.rs

@@ -1441,6 +1441,8 @@ mod fn_impls {
 
     #[cfg(test)]
     mod tests {
+        use super::Arc;
+
         #[test]
         fn is_fn() {
             use_fn(Arc::new(|x| x + 1));

src/liballoc/lib.rs

@@ -125,8 +125,9 @@
 #![feature(exact_chunks)]
 #![feature(pointer_methods)]
 #![feature(inclusive_range_fields)]
+#![feature(fn_traits)]
 
-#![cfg_attr(not(test), feature(fn_traits, placement_new_protocol, swap_with_slice, i128))]
+#![cfg_attr(not(test), feature(placement_new_protocol, swap_with_slice, i128))]
 #![cfg_attr(test, feature(test, box_heap))]
 
 // Allow testing this library

src/liballoc/rc.rs

@@ -1416,6 +1416,8 @@ mod fn_impls {
 
     #[cfg(test)]
     mod tests {
+        use super::Rc;
+
         #[test]
         fn is_fn() {
             use_fn(Rc::new(|x| x + 1));