From 4d42b61e02691f372e649f0fb497829109bf550e Mon Sep 17 00:00:00 2001
From: relaxcn <irelaxcn@outlook.com>
Date: Tue, 14 Oct 2025 00:12:22 +0800
Subject: [PATCH] Make `ops::DerefMut` a diagnostic item

---
 compiler/rustc_span/src/symbol.rs | 1 +
 library/core/src/ops/deref.rs     | 1 +
 2 files changed, 2 insertions(+)

diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 4f21189f9a7d5..639b5d0e9c423 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -219,6 +219,7 @@ symbols! {
         Decoder,
         Default,
         Deref,
+        DerefMut,
         DiagMessage,
         Diagnostic,
         DirBuilder,
diff --git a/library/core/src/ops/deref.rs b/library/core/src/ops/deref.rs
index 305861ea7b698..931ccfc4fd54e 100644
--- a/library/core/src/ops/deref.rs
+++ b/library/core/src/ops/deref.rs
@@ -266,6 +266,7 @@ impl<T: ?Sized> const Deref for &mut T {
 #[lang = "deref_mut"]
 #[doc(alias = "*")]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_diagnostic_item = "DerefMut"]
 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
 pub const trait DerefMut: [const] Deref + PointeeSized {
     /// Mutably dereferences the value.