const-stabilize NonNull::dangling and NonNull::cast

Author: SimonSapin

src/libcore/ptr.rs

@@ -2959,7 +2959,6 @@ impl<T: Sized> NonNull<T> {
     /// some other means.
     #[stable(feature = "nonnull", since = "1.25.0")]
     #[inline]
-    #[rustc_const_unstable(feature = "const_ptr_nonnull")]
     pub const fn dangling() -> Self {
         unsafe {
             let ptr = mem::align_of::<T>() as *mut T;
@@ -3023,7 +3022,6 @@ impl<T: ?Sized> NonNull<T> {
     /// Cast to a pointer of another type
     #[stable(feature = "nonnull_cast", since = "1.27.0")]
     #[inline]
-    #[rustc_const_unstable(feature = "const_ptr_nonnull")]
     pub const fn cast<U>(self) -> NonNull<U> {
         unsafe {
             NonNull::new_unchecked(self.as_ptr() as *mut U)

src/test/run-pass/consts/const-ptr-nonnull.rs

@@ -1,7 +1,5 @@
 // run-pass
 
-#![feature(const_ptr_nonnull)]
-
 use std::ptr::NonNull;
 
 const DANGLING: NonNull<u32> = NonNull::dangling();