Rollup merge of rust-lang#46121 - malbarbo:rc_arc_pointer, r=dtolnay

Print the address of the pointed value in Pointer impl for Rc and Arc

Fixes rust-lang#35384

Author: kennytm

src/liballoc/arc.rs

@@ -1328,7 +1328,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Arc<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> fmt::Pointer for Arc<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&self.ptr, f)
+        fmt::Pointer::fmt(&(&**self as *const T), f)
     }
 }
 

src/liballoc/rc.rs

@@ -1072,7 +1072,7 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Rc<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> fmt::Pointer for Rc<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Pointer::fmt(&self.ptr, f)
+        fmt::Pointer::fmt(&(&**self as *const T), f)
     }
 }