Add is_intrinsic helper

compiler/rustc_middle/src/ty/intrinsic.rs

@@ -0,0 +1,10 @@
+use rustc_span::{def_id::DefId, Symbol};
+
+use super::TyCtxt;
+
+impl TyCtxt<'_> {
+    pub fn is_intrinsic(self, def_id: DefId, name: Symbol) -> bool {
+        let Some(i) = self.intrinsic(def_id) else { return false };
+        i == name
+    }
+}

compiler/rustc_middle/src/ty/mod.rs

@@ -149,6 +149,7 @@ mod generic_args;
 mod generics;
 mod impls_ty;
 mod instance;
+mod intrinsic;
 mod list;
 mod opaque_types;
 mod parameterized;