message: Use Map for Reference.prevIndexObj
diff: @@ -34,7 +34,7 @@ export class Reference implements IProvider {
  private readonly extension: Extension
  // Here we use an object instead of an array for de-duplication
  private readonly suggestions = new Map<string, ReferenceEntry>()
  - private prevIndexObj: { [k: string]: {refNumber: string, pageNumber: string} } = {}
  + private prevIndexObj = new Map<string, {refNumber: string, pageNumber: string}>()
  constructor(extension: Extension) {
  this.extension = extension
  @@ -124,7 +124,7 @@ export class Reference implements IProvider {
  file: cachedFile,
  position: ref.range instanceof vscode.Range ? ref.range.start : ref.range.inserting.start,
  range,
  - prevIndex: this.prevIndexObj[ref.label]
  + prevIndex: this.prevIndexObj.get(ref.label)
  })
  refList.push(ref.label)
  })
  @@ -223,7 +223,7 @@ export class Reference implements IProvider {
  this.suggestions.forEach((entry) => {
  entry.prevIndex = undefined
  })
  - this.prevIndexObj = {}
  + this.prevIndexObj = new Map<string, {refNumber: string, pageNumber: string}>()
  if (!fs.existsSync(auxFile)) {
  return
  }
  @@ -238,7 +238,7 @@ export class Reference implements IProvider {
  // Drop extra \newlabel entries added by cleveref
  continue
  }
  - this.prevIndexObj[result[1]] = {refNumber: result[2], pageNumber: result[3]}
  + this.prevIndexObj.set(result[1], {refNumber: result[2], pageNumber: result[3]})
  const ent = this.suggestions.get(result[1])
  if (ent) {
  ent.prevIndex = {refNumber: result[2], pageNumber: result[3]}
  