chrome 原生promise 实现 promise.map

function yibu(i) {        return new Promise(function (resolve, reject) {            setTimeout(function () {                console.log("hello" + i)                resolve();            }, 1000)        });    }    var start = new Promise(function (resolve) {        resolve();    })    for (let i = 1; i < 10; i++) {        start = start.then(function () {            return yibu(i)        })    }