Automatic completion of file names issue when import files

[star-reader]

I just found there is an issue when importing files in .vue files.
When trying to import some file in .vue files, the automatic completion of file names speed is so slow,
for example:

import use3DPath from '@/hooks/map/use3DPath'

after typed "@/", it will takes about 2~5 seconds to show the file list, however in other mode, it's normal.

[star-reader]

In my old computer I've already found that issue(in Vue2 with vetur it's normal). I thought it's beacuse my computer's poor performance. After I changed to a new computer, volar still has this issue

[johnsoncodehk]

Resolved by #3788.