Tag SyncUnsafeCell functions with #[rustc_as_ptr]

Author: gavincrawford

library/core/src/cell.rs

@@ -2306,6 +2306,7 @@ impl<T: ?Sized> SyncUnsafeCell<T> {
     /// when casting to `&mut T`, and ensure that there are no mutations
     /// or mutable aliases going on when casting to `&T`
     #[inline]
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[rustc_never_returns_null_ptr]
     pub const fn get(&self) -> *mut T {
         self.value.get()
@@ -2323,6 +2324,7 @@ impl<T: ?Sized> SyncUnsafeCell<T> {
     /// Gets a mutable pointer to the wrapped value.
     ///
     /// See [`UnsafeCell::get`] for details.
+    #[cfg_attr(not(bootstrap), rustc_as_ptr)]
     #[inline]
     pub const fn raw_get(this: *const Self) -> *mut T {
         // We can just cast the pointer from `SyncUnsafeCell<T>` to `T` because