[Bug Report] webpack下vue2.7.x, el-table渲染空白

### Element UI version
2.15.9

### OS/Browsers version
macOS 12.4

### Vue version
2.7.4

### Reproduction Link
https://github.com/MinatoHikari/vue2.7-bug

### Steps to reproduce
git clone 复现链接项目，安装依赖
npm run dev 并打开默认页面

将vue-template-complier改成2.6.14
npm run dev 并打开默认页面

### What is Expected?
vue-template-complier 2.7.4 下el-table正常渲染

### What is actually happening?
vue-template-complier 2.6.14 下el-table正常渲染
vue-template-complier 2.7.4 下el-table渲染空白