rust: task: implement == operator for Task

It's useful to compare if two tasks are the same task or not. Rust
Binder wants this to check if a certain task is equal to the group
leader of current.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260324-close-fd-check-current-v3-2-b94274bedac7@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rust/kernel/task.rs

@@ -362,6 +362,15 @@ unsafe impl crate::sync::aref::AlwaysRefCounted for Task {
     }
 }
 
+impl PartialEq for Task {
+    #[inline]
+    fn eq(&self, other: &Self) -> bool {
+        ptr::eq(self.as_ptr(), other.as_ptr())
+    }
+}
+
+impl Eq for Task {}
+
 impl Kuid {
     /// Get the current euid.
     #[inline]