IE11 support

[zhaopengweily]

there is an error in IE11
缺少 ':'
SyntaxError: 缺少 ':'
at k (http://localhost:8080/js/chunk-vendors.js:5299:642225)
at _callee46$ (http://localhost:8080/js/chunk-vendors.js:5299:635484)
at tryCatch (http://localhost:8080/js/chunk-vendors.js:20872:7)
at Anonymous function (http://localhost:8080/js/chunk-vendors.js:20962:9)
at Anonymous function (http://localhost:8080/js/chunk-vendors.js:20903:9)
at asyncGeneratorStep (http://localhost:8080/js/chunk-vendors.js:20406:5)
at _next (http://localhost:8080/js/chunk-vendors.js:20420:9)
at callReaction (http://localhost:8080/js/chunk-vendors.js:32617:9)
at Anonymous function (http://localhost:8080/js/chunk-vendors.js:32642:7)
at flush (http://localhost:8080/js/chunk-vendors.js:26680:7)

ues demo like this:
import Vue from 'vue'
import { loadModule } from "vue3-sfc-loader/dist/vue2-sfc-loader";
const config = {
// note: Here, for convenience, we simply retrieve content from a string.
files: {
/* */
}
};

const options = {
moduleCache: { vue: Vue },
getFile: function(url) { return config.files[url] },
addStyle: function () {},
}

loadModule('/app.vue', options)
.then(function(app) {
new Vue(app).$mount('#app')
});