实现一个原生的数组push

[lynhao]

Array.prototype._push = function(...items) {
    let O = new Object(this);
    let len = O.length >>> 0;  // 取整
    let argCount = items.length >>> 0; // 取整
    let E = O;
    if (len + argCount > 2 ** 53 - 1) {
        throw new TypeError("the number of array os over the max value restrocted!");
    }

    for(let i = 0; i < argCount; i++) {
        E[len + i] = items[i];
        len++;
    }
    O.length =  len;
    return len;
}

测试用例后面补上, 先手动测吧😀