{"ast_node_type":"other","tokens":[{"end":105,"kind":"keyword","start":0,"text":"//"}]}
        // If it's a frozen shared reference that's not already immutable, potentially make it immutable.
    ) -> InterpResult<'tcx, ImmTy<'tcx, CtfeProvenance>> {
        // (Do nothing on `None` provenance, that cannot store immutability anyway.)