ANDROID: rust_binder: add back tracepoints

Tracepoints were removed from the the vendor module version of Rust
Binder as it required either fixing b/394605825 or hard-coding the
tracepoint declarations as created by bindgen.

As we are moving Rust Binder back into common/, this no longer depends
on invoking bindgen from the DDK. Thus, revert these changes.

Bug: 394605825
Bug: 388786466
Change-Id: I81fe5b2b4c92826c6478606cd78c8fccd8a5c7e4
Signed-off-by: Alice Ryhl <aliceryhl@google.com>

rust/kernel/sync/arc.rs

@@ -206,6 +206,9 @@ impl<T> Arc<T> {
         // `Arc` object.
         Ok(unsafe { Self::from_inner(KBox::leak(inner).into()) })
     }
+
+    /// The offset that the value is stored at.
+    pub const DATA_OFFSET: usize = core::mem::offset_of!(ArcInner<T>, data);
 }
 
 impl<T: ?Sized> Arc<T> {