Fix feature name

Author: alexbool

src/liballoc/arc.rs

@@ -895,7 +895,7 @@ impl<T: ?Sized + Hash> Hash for Arc<T> {
     }
 }
 
-#[stable(feature = "rust1", since = "1.6.0")]
+#[stable(feature = "from_for_ptrs", since = "1.6.0")]
 impl<T> From<T> for Arc<T> {
     fn from(t: T) -> Self {
         Arc::new(t)

src/liballoc/boxed.rs

@@ -376,7 +376,7 @@ impl<T: ?Sized + Hash> Hash for Box<T> {
     }
 }
 
-#[stable(feature = "rust1", since = "1.6.0")]
+#[stable(feature = "from_for_ptrs", since = "1.6.0")]
 impl<T> From<T> for Box<T> {
     fn from(t: T) -> Self {
         Box::new(t)

src/liballoc/rc.rs

@@ -699,7 +699,7 @@ impl<T> fmt::Pointer for Rc<T> {
     }
 }
 
-#[stable(feature = "rust1", since = "1.6.0")]
+#[stable(feature = "from_for_ptrs", since = "1.6.0")]
 impl<T> From<T> for Rc<T> {
     fn from(t: T) -> Self {
         Rc::new(t)