Accessing private function outside of the contract

NotSoPrivateFn.sol

// SPDX-License-Identifier: UNLICENSE

pragma solidity >=0.8.0 <0.9.0;

contract Private {
    function t_() private returns (uint256) {
        return 1;
    }

    function rt() public returns (bytes32 fp) {
        function () returns (uint256) t = t_;
        assembly {
            fp := t
        }
    }
}

contract P is Private {
    function p(bytes32 fp) public returns (uint256) {
        function () returns (uint256) t;
        assembly {
            t := fp
        }
        return t();
    }

    // the below, if uncommented makes this contract not compile
    // function f() public returns (uint256) {
    //     return t_();
    // }
}