Detect Option via lang item instead of diagnostics string

Author: 1c3t3a

compiler/rustc_codegen_llvm/src/consts.rs

@@ -5,6 +5,7 @@ use rustc_abi::{
 };
 use rustc_codegen_ssa::common;
 use rustc_codegen_ssa::traits::*;
+use rustc_hir::LangItem;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
@@ -16,7 +17,6 @@ use rustc_middle::mir::mono::{Linkage, MonoItem};
 use rustc_middle::ty::layout::{HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{self, Instance};
 use rustc_middle::{bug, span_bug};
-use rustc_span::sym;
 use tracing::{debug, instrument, trace};
 
 use crate::common::{AsCCharPtr, CodegenCx};
@@ -180,9 +180,9 @@ fn check_and_apply_linkage<'ll, 'tcx>(
             // instead of an extern_weak i8.
             let instance = Instance::mono(cx.tcx, def_id);
             if let ty::Adt(struct_def, generic_args) = instance.ty(cx.tcx, cx.typing_env()).kind()
-                && matches!(cx.tcx.get_diagnostic_name(struct_def.did()), Some(sym::Option))
-                && generic_args.len() == 1
-                && let ty::FnPtr(sig, header) = generic_args.first().unwrap().expect_ty().kind()
+                && let Some(LangItem::Option) = cx.tcx.lang_items().from_def_id(struct_def.did())
+                && let Some(first_arg) = generic_args.first()
+                && let ty::FnPtr(sig, header) = first_arg.expect_ty().kind()
             {
                 let fn_sig = sig.with(*header);