fix: fix Promise.finally missing in Firefox

fix #2012

packages/@vue/babel-preset-app/README.md

@@ -76,7 +76,7 @@ See [@babel/preset-env docs](https://new.babeljs.io/docs/en/next/babel-preset-en
 
 ### polyfills
 
-- Default: `['es6.promise', 'es6.array.iterator']`
+- Default: `['es6.array.iterator', 'es6.promise', 'es7.promise.finally']`
 
 A list of [core-js](https://github.com/zloirock/core-js) polyfills to pre-include when using `useBuiltIns: 'usage'`. **These polyfills are automatically excluded if they are not needed for your target environments**.
 

packages/@vue/babel-preset-app/index.js

@@ -1,10 +1,13 @@
 const path = require('path')
 
 const defaultPolyfills = [
-  'es6.promise',
   // promise polyfill alone doesn't work in IE,
   // needs this as well. see: #1642
-  'es6.array.iterator'
+  'es6.array.iterator',
+  // this is required for webpack code splitting, vuex etc.
+  'es6.promise',
+  // #2012 es6.promise replaces native Promise in FF and causes missing finally
+  'es7.promise.finally'
 ]
 
 function getPolyfills (targets, includes, { ignoreBrowserslistConfig, configPath }) {

packages/@vue/babel-preset-app/polyfillsPlugin.js

@@ -13,7 +13,8 @@ module.exports = ({ types }) => {
 
         const { polyfills } = state.opts
         const { createImport } = require('@babel/preset-env/lib/utils')
-        polyfills.forEach(p => {
+        // imports are injected in reverse order
+        polyfills.slice().reverse().forEach(p => {
           createImport(path, p)
         })
       }