Rollup merge of #108964 - majaha:ptr_metadata_doc, r=workingjubilee

Fix the docs for pointer method with_metadata_of

The name of the argument to `{*const T, *mut T}::with_metadata_of` was changed from `val` to `meta` recently, but the docs weren't updated to match.

Relevant pull request: #103701

library/core/src/ptr/const_ptr.rs

@@ -61,14 +61,14 @@ pub const fn cast<U>(self) -> *const U {
 
     /// Use the pointer value in a new pointer of another type.
     ///
-    /// In case `val` is a (fat) pointer to an unsized type, this operation
+    /// In case `meta` is a (fat) pointer to an unsized type, this operation
     /// will ignore the pointer part, whereas for (thin) pointers to sized
     /// types, this has the same effect as a simple cast.
     ///
     /// The resulting pointer will have provenance of `self`, i.e., for a fat
     /// pointer, this operation is semantically the same as creating a new
     /// fat pointer with the data pointer value of `self` but the metadata of
-    /// `val`.
+    /// `meta`.
     ///
     /// # Examples
     ///

library/core/src/ptr/mut_ptr.rs

@@ -60,14 +60,14 @@ pub const fn cast<U>(self) -> *mut U {
 
     /// Use the pointer value in a new pointer of another type.
     ///
-    /// In case `val` is a (fat) pointer to an unsized type, this operation
+    /// In case `meta` is a (fat) pointer to an unsized type, this operation
     /// will ignore the pointer part, whereas for (thin) pointers to sized
     /// types, this has the same effect as a simple cast.
     ///
     /// The resulting pointer will have provenance of `self`, i.e., for a fat
     /// pointer, this operation is semantically the same as creating a new
     /// fat pointer with the data pointer value of `self` but the metadata of
-    /// `val`.
+    /// `meta`.
     ///
     /// # Examples
     ///