{"ast_node_type":"function","tokens":[{"end":55,"kind":"keyword","start":0,"text":"fn"}]}
    fn reg_backend_type(&self, ty: &Reg) -> Self::Type;
    fn fn_ptr_backend_type(&self, fn_abi: &FnAbi<'tcx, Ty<'tcx>>) -> Self::Type;
    /// The backend type used for a rust type when it's in an SSA register.