Generated compatibility code error

[hdcljt]

• Vue@3.0.11 code

export function flushPostFlushCbs(seen?: CountMap) {
  if (pendingPostFlushCbs.length) {
    const deduped = [...new Set(pendingPostFlushCbs)]
    pendingPostFlushCbs.length = 0
  }
}

The problem is in this place

const deduped = [...new Set(pendingPostFlushCbs)]

• @vitejs/plugin-legacy@1.3.4 translated code

var deduped=[].concat(new Set(pendingPostFlushCbs))

The configuration file look like this:

{
    plugins: [vue(), legacy({ targets: ['defaults', 'since 2016', 'not IE 11'] })],
    build: {
        target: 'es2015',
        minify: false
    }
}

'since 2016'