Revert "Added AsRef implementations for Arc and Rc"

This reverts commit 7f3ae0a.

Author: alexcrichton

src/liballoc/arc.rs

@@ -330,15 +330,6 @@ impl<T: ?Sized> Deref for Arc<T> {
     }
 }
 
-#[stable(feature = "rc_arc_as_ref", since = "1.2.0")]
-impl<T: ?Sized> AsRef<T> for Arc<T> {
-
-    #[inline]
-    fn as_ref(&self) -> &T {
-        &self.inner().data
-    }
-}
-
 impl<T: Clone> Arc<T> {
     /// Make a mutable reference from the given `Arc<T>`.
     ///

src/liballoc/rc.rs

@@ -156,7 +156,6 @@ use std::boxed;
 use core::cell::Cell;
 use core::clone::Clone;
 use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering};
-use core::convert::AsRef;
 use core::default::Default;
 use core::fmt;
 use core::hash::{Hasher, Hash};
@@ -380,15 +379,6 @@ impl<T: ?Sized> Deref for Rc<T> {
     }
 }
 
-#[stable(feature = "rc_arc_as_ref", since = "1.2.0")]
-impl<T: ?Sized> AsRef<T> for Rc<T> {
-
-    #[inline(always)]
-    fn as_ref(&self) -> &T {
-        &self.inner().value
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> Drop for Rc<T> {
     /// Drops the `Rc<T>`.