refactor(data_structures): remove NonNull shim (#8423)

The `NonNull` shim in `oxc_data_structures` was just to emulate native APIs which only became stable in Rust 1.80.0. #8407 bumped our MSRV to 1.80.0, so now we can remove the shim and use `std::ptr::NonNull` directly.

crates/oxc_data_structures/src/stack/common.rs

@@ -3,12 +3,13 @@
 use std::{
     alloc::{self, Layout},
     mem::{align_of, size_of},
-    ptr, slice,
+    ptr::{self, NonNull},
+    slice,
 };
 
 use assert_unchecked::assert_unchecked;
 
-use super::{NonNull, StackCapacity};
+use super::StackCapacity;
 
 pub trait StackCommon<T>: StackCapacity<T> {
     // Getter + setter methods defined by implementer

crates/oxc_data_structures/src/stack/mod.rs

@@ -9,13 +9,11 @@
 mod capacity;
 mod common;
 mod non_empty;
-mod non_null;
 mod sparse;
 mod standard;
 
 use capacity::StackCapacity;
 use common::StackCommon;
 pub use non_empty::NonEmptyStack;
-use non_null::NonNull;
 pub use sparse::SparseStack;
 pub use standard::Stack;

crates/oxc_data_structures/src/stack/non_empty.rs

@@ -3,9 +3,10 @@
 use std::{
     mem::size_of,
     ops::{Deref, DerefMut},
+    ptr::NonNull,
 };
 
-use super::{NonNull, StackCapacity, StackCommon};
+use super::{StackCapacity, StackCommon};
 
 /// A stack which can never be empty.
 ///

crates/oxc_data_structures/src/stack/non_null.rs

@@ -1,109 +0,0 @@
-#![expect(clippy::inline_always)]
-
-use std::{cmp::Ordering, ptr::NonNull as NativeNonNull};
-
-/// Wrapper around `NonNull<T>`, which adds methods `add`, `sub`, `offset_from`, `byte_offset_from`,
-/// and `read`.
-/// These methods exist on `std::ptr::NonNull`, and became stable in Rust 1.80.0, but are not yet
-/// stable in our MSRV.
-///
-/// These methods are much cleaner than the workarounds required in older Rust versions,
-/// and make code using them easier to understand.
-///
-/// Once we bump MSRV and these methods are natively supported, this type can be removed.
-/// `#[expect(clippy::incompatible_msrv)]` on `_non_null_add_is_not_stable` below will trigger
-/// a lint warning when that happens.
-/// Then this module can be deleted, and all uses of this type can be switched to `std::ptr::NonNull`.
-#[derive(Debug)]
-#[repr(transparent)]
-pub struct NonNull<T>(NativeNonNull<T>);
-
-impl<T> NonNull<T> {
-    #[inline(always)]
-    pub const unsafe fn new_unchecked(ptr: *mut T) -> Self {
-        Self(NativeNonNull::new_unchecked(ptr))
-    }
-
-    #[inline(always)]
-    pub const fn dangling() -> Self {
-        Self(NativeNonNull::dangling())
-    }
-
-    #[inline(always)]
-    pub const fn as_ptr(self) -> *mut T {
-        self.0.as_ptr()
-    }
-
-    #[inline(always)]
-    pub const fn cast<U>(self) -> NonNull<U> {
-        // SAFETY: `self` is non-null, so it's still non-null after casting
-        unsafe { NonNull::new_unchecked(self.as_ptr().cast()) }
-    }
-
-    #[inline(always)]
-    pub const unsafe fn add(self, count: usize) -> Self {
-        NonNull(NativeNonNull::new_unchecked(self.as_ptr().add(count)))
-    }
-
-    #[inline(always)]
-    pub const unsafe fn sub(self, count: usize) -> Self {
-        NonNull(NativeNonNull::new_unchecked(self.as_ptr().sub(count)))
-    }
-
-    #[inline(always)]
-    pub const unsafe fn offset_from(self, origin: Self) -> isize {
-        self.as_ptr().offset_from(origin.as_ptr())
-    }
-
-    #[inline(always)]
-    pub const unsafe fn byte_offset_from(self, origin: Self) -> isize {
-        self.as_ptr().byte_offset_from(origin.as_ptr())
-    }
-
-    #[inline(always)]
-    pub const unsafe fn as_ref<'t>(self) -> &'t T {
-        self.0.as_ref()
-    }
-
-    #[inline(always)]
-    pub unsafe fn as_mut<'t>(mut self) -> &'t mut T {
-        self.0.as_mut()
-    }
-
-    #[inline(always)]
-    pub unsafe fn read(self) -> T {
-        self.0.as_ptr().read()
-    }
-}
-
-impl<T> Copy for NonNull<T> {}
-
-impl<T> Clone for NonNull<T> {
-    #[inline(always)]
-    fn clone(&self) -> Self {
-        *self
-    }
-}
-
-impl<T> Eq for NonNull<T> {}
-
-impl<T> PartialEq for NonNull<T> {
-    #[inline(always)]
-    fn eq(&self, other: &Self) -> bool {
-        self.0 == other.0
-    }
-}
-
-impl<T> Ord for NonNull<T> {
-    #[inline(always)]
-    fn cmp(&self, other: &Self) -> Ordering {
-        self.as_ptr().cmp(&other.as_ptr())
-    }
-}
-
-impl<T> PartialOrd for NonNull<T> {
-    #[inline(always)]
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}

crates/oxc_data_structures/src/stack/standard.rs

@@ -3,9 +3,10 @@
 use std::{
     mem::size_of,
     ops::{Deref, DerefMut},
+    ptr::NonNull,
 };
 
-use super::{NonNull, StackCapacity, StackCommon};
+use super::{StackCapacity, StackCommon};
 
 /// A simple stack.
 ///