Error message no longer implies #[track_caller] is a requirement for Rust ABI.

src/librustc_typeck/collect.rs

@@ -2616,7 +2616,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
                     tcx.sess,
                     attr.span,
                     E0737,
-                    "Rust ABI is required to use `#[track_caller]`"
+                    "`#[track_caller]` requires Rust ABI"
                 ).emit();
             }
             codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER;

src/test/ui/rfc-2091-track-caller/error-with-invalid-abi.rs

 #![feature(track_caller)]
 
-#[track_caller] //~ ERROR Rust ABI is required to use `#[track_caller]`
+#[track_caller]
 extern "C" fn f() {}
+//~^^ ERROR `#[track_caller]` requires Rust ABI
 
 fn main() {}

src/test/ui/rfc-2091-track-caller/error-with-invalid-abi.stderr

-error[E0737]: Rust ABI is required to use `#[track_caller]`
+error[E0737]: `#[track_caller]` requires Rust ABI
   --> $DIR/error-with-invalid-abi.rs:3:1
    |
 LL | #[track_caller]