Add FIXME

Author: bjorn3

compiler/rustc_interface/src/queries.rs

@@ -123,6 +123,7 @@ impl<'tcx> Queries<'tcx> {
                 &sess.opts.unstable_opts.crate_attr,
             );
 
+            // FIXME modify krate.attrs in place once #65860 is a hard error.
             let pre_configured_attrs =
                 rustc_expand::config::pre_configure_attrs(sess, &krate.attrs);