Fix visibility of some Kani intrinsics (rust-lang#3323)

This PR fixes inadvertently exposing some of the unstable Kani
intrinsics.

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 and MIT licenses.

Author: artemagvanian

library/kani/src/mem.rs

@@ -300,7 +300,7 @@ unsafe fn has_valid_value<T: ?Sized>(_ptr: *const T) -> bool {
 /// Check whether `len * size_of::<T>()` bytes are initialized starting from `ptr`.
 #[rustc_diagnostic_item = "KaniIsInitialized"]
 #[inline(never)]
-pub fn is_initialized<T: ?Sized>(_ptr: *const T) -> bool {
+pub(crate) fn is_initialized<T: ?Sized>(_ptr: *const T) -> bool {
     kani_intrinsic()
 }
 
@@ -311,13 +311,25 @@ fn assert_is_initialized<T: ?Sized>(ptr: *const T) -> bool {
 }
 
 /// Get the object ID of the given pointer.
+#[doc(hidden)]
+#[crate::unstable(
+    feature = "ghost-state",
+    issue = 3184,
+    reason = "experimental ghost state/shadow memory API"
+)]
 #[rustc_diagnostic_item = "KaniPointerObject"]
 #[inline(never)]
 pub fn pointer_object<T: ?Sized>(_ptr: *const T) -> usize {
     kani_intrinsic()
 }
 
 /// Get the object offset of the given pointer.
+#[doc(hidden)]
+#[crate::unstable(
+    feature = "ghost-state",
+    issue = 3184,
+    reason = "experimental ghost state/shadow memory API"
+)]
 #[rustc_diagnostic_item = "KaniPointerOffset"]
 #[inline(never)]
 pub fn pointer_offset<T: ?Sized>(_ptr: *const T) -> usize {

library/kani_core/src/mem.rs

@@ -306,7 +306,7 @@ macro_rules! kani_mem {
         /// Check whether `len * size_of::<T>()` bytes are initialized starting from `ptr`.
         #[rustc_diagnostic_item = "KaniIsInitialized"]
         #[inline(never)]
-        pub fn is_initialized<T: ?Sized>(_ptr: *const T) -> bool {
+        pub(crate) fn is_initialized<T: ?Sized>(_ptr: *const T) -> bool {
             kani_intrinsic()
         }
 
@@ -320,16 +320,30 @@ macro_rules! kani_mem {
         }
 
         /// Get the object ID of the given pointer.
+        // TODO: Add this back later, as there is no unstable attribute here.
+        // #[doc(hidden)]
+        // #[crate::unstable(
+        //     feature = "ghost-state",
+        //     issue = 3184,
+        //     reason = "experimental ghost state/shadow memory API"
+        // )]
         #[rustc_diagnostic_item = "KaniPointerObject"]
         #[inline(never)]
-        pub fn pointer_object<T: ?Sized>(_ptr: *const T) -> usize {
+        pub(crate) fn pointer_object<T: ?Sized>(_ptr: *const T) -> usize {
             kani_intrinsic()
         }
 
         /// Get the object offset of the given pointer.
+        // TODO: Add this back later, as there is no unstable attribute here.
+        // #[doc(hidden)]
+        // #[crate::unstable(
+        //     feature = "ghost-state",
+        //     issue = 3184,
+        //     reason = "experimental ghost state/shadow memory API"
+        // )]
         #[rustc_diagnostic_item = "KaniPointerOffset"]
         #[inline(never)]
-        pub fn pointer_offset<T: ?Sized>(_ptr: *const T) -> usize {
+        pub(crate) fn pointer_offset<T: ?Sized>(_ptr: *const T) -> usize {
             kani_intrinsic()
         }
     };