Duplicate props show Duplicate Identifier error in wrong place

[andrewisaburden]

• I have searched through existing issues

Info

• Vetur version: 0.30.0
• VS Code version: any

Problem

Duplicate props don't show errors in the correct file, with correct line numbers.

Reproducible Case

Breaking test is to modify class-child.vue:

<script>
import { Vue, Component, Prop, PropSync, Model } from 'vue-property-decorator'

@Component({
  props: { foo: Number }
})
export default class Child extends Vue {
  @Prop(Number) bar
  @Prop({ default: 'car' }) car
  @Prop({ required: false }) dar
  @Prop({ required: true }) ear
  @Prop() ear
  @Prop([String, Number]) far
  @PropSync('name', { type: String }) syncedName

  @Model('change', { required: true }) checked
}
</script>

By adding @Prop() ear we now have duplicated the ear prop.

Expected result is to see both lines defining the ear prop to be errored, and for the class-child.vue file to be the source of the error.

Actual result is to see

Duplicate identifier 'ear'.Vetur(2300)
Duplicate identifier 'ear'.Vetur(2300)

in parent.vue with 0,0 as line number, character.

[yoyo930021]

If you can provide a project, we can study more easily.

[andrewisaburden]

https://github.com/andrewisaburden/veturpack/tree/2459-reproduction reproduction project.