Add backticks to E0558

src/librustc_codegen_llvm/diagnostics.rs

@@ -48,8 +48,3 @@ unsafe { simd_add(i32x2(0, 0), i32x2(1, 2)); } // ok!
 "##,
 
 }
-
-
-register_diagnostics! {
-    E0558
-}

src/librustc_typeck/collect.rs

@@ -1909,7 +1909,7 @@ fn codegen_fn_attrs<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: DefId) -> Codegen
                 codegen_fn_attrs.export_name = Some(s);
             } else {
                 struct_span_err!(tcx.sess, attr.span, E0558,
-                                 "export_name attribute has invalid format")
+                                 "`export_name` attribute has invalid format")
                     .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
                     .emit();
             }

src/librustc_typeck/diagnostics.rs

@@ -3709,7 +3709,7 @@ The `export_name` attribute was malformed.
 Erroneous code example:
 
 ```ignore (error-emitted-at-codegen-which-cannot-be-handled-by-compile_fail)
-#[export_name] // error: export_name attribute has invalid format
+#[export_name] // error: `export_name` attribute has invalid format
 pub fn something() {}
 
 fn main() {}

src/test/ui/error-codes/E0558.stderr

@@ -1,4 +1,4 @@
-error[E0558]: export_name attribute has invalid format
+error[E0558]: `export_name` attribute has invalid format
   --> $DIR/E0558.rs:11:1
    |
 LL | #[export_name]