Rename OperandBundleOwned to OperandBundleBox

As with `DIBuilderBox`, the "Box" suffix does a better job of communicating
that this is an owning pointer to some borrowable resource.

This also renames the `raw` method to `as_ref`, which is what it would have
been named originally if the `Deref` problem had been known at the time.

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -363,12 +363,13 @@ pub(crate) fn last_error() -> Option<String> {
     }
 }
 
-/// Owns an [`OperandBundle`], and will dispose of it when dropped.
-pub(crate) struct OperandBundleOwned<'a> {
+/// Owning pointer to an [`OperandBundle`] that will dispose of the bundle
+/// when dropped.
+pub(crate) struct OperandBundleBox<'a> {
     raw: ptr::NonNull<OperandBundle<'a>>,
 }
 
-impl<'a> OperandBundleOwned<'a> {
+impl<'a> OperandBundleBox<'a> {
     pub(crate) fn new(name: &str, vals: &[&'a Value]) -> Self {
         let raw = unsafe {
             LLVMCreateOperandBundle(
@@ -378,21 +379,21 @@ impl<'a> OperandBundleOwned<'a> {
                 vals.len() as c_uint,
             )
         };
-        OperandBundleOwned { raw: ptr::NonNull::new(raw).unwrap() }
+        Self { raw: ptr::NonNull::new(raw).unwrap() }
     }
 
-    /// Returns inner `OperandBundle` type.
+    /// Dereferences to the underlying `&OperandBundle`.
     ///
-    /// This could be a `Deref` implementation, but `OperandBundle` contains an extern type and
-    /// `Deref::Target: ?Sized`.
-    pub(crate) fn raw(&self) -> &OperandBundle<'a> {
+    /// This can't be a `Deref` implementation because `OperandBundle` transitively
+    /// contains an extern type, which is incompatible with `Deref::Target: ?Sized`.
+    pub(crate) fn as_ref(&self) -> &OperandBundle<'a> {
         // SAFETY: The returned reference is opaque and can only used for FFI.
         // It is valid for as long as `&self` is.
         unsafe { self.raw.as_ref() }
     }
 }
 
-impl Drop for OperandBundleOwned<'_> {
+impl Drop for OperandBundleBox<'_> {
     fn drop(&mut self) {
         unsafe {
             LLVMDisposeOperandBundle(self.raw);