Remove redundant stable and unstable attributes in primitives.rs

Author: lygstate

library/core/src/ffi/primitives.rs

@@ -10,7 +10,6 @@ macro_rules! type_alias {
     } => {
         #[doc = include_str!($Docfile)]
         $( $Cfg )*
-        #[stable(feature = "core_ffi_c", since = "1.64.0")]
         pub type $Alias = $Real;
     }
 }
@@ -154,21 +153,18 @@ mod c_long_definition {
 ///
 /// This type is currently always [`usize`], however in the future there may be
 /// platforms where this is not the case.
-#[unstable(feature = "c_size_t", issue = "88345")]
 pub type c_size_t = usize;
 
 /// Equivalent to C's `ptrdiff_t` type, from `stddef.h` (or `cstddef` for C++).
 ///
 /// This type is currently always [`isize`], however in the future there may be
 /// platforms where this is not the case.
-#[unstable(feature = "c_size_t", issue = "88345")]
 pub type c_ptrdiff_t = isize;
 
 /// Equivalent to C's `ssize_t` (on POSIX) or `SSIZE_T` (on Windows) type.
 ///
 /// This type is currently always [`isize`], however in the future there may be
 /// platforms where this is not the case.
-#[unstable(feature = "c_size_t", issue = "88345")]
 pub type c_ssize_t = isize;
 
 mod c_int_definition {