Multiple lines attributes break syntax highlighting for scss

[CaptainYouz]

• [yes] I have searched through existing issues
• [yes] I have read through docs
• [no] I have read FAQ

Info

• Platform: macOs
• Vetur version: 0.22.5
• VS Code version: 1.39.2

Problem

In the <style> part of the vue file, when putting style attributes in multiple lines, it messes up the syntax highlighting of the scss.

If

<style lang="scss" scoped>

become

<style
  lang="scss"
  scoped
>

then the scss syntax highlighting become weird.

before:

after:

Reproducible Case

Put <style> attributes on multiple lines.

[octref]

The grammar is fragile and I'm not sure what's the best way to support this. PR with test cases are welcome.