message: Fix LocationLink:is to follow spec.
diff: @@ -244,7 +244,7 @@ export namespace LocationLink {
  export function is(value: any): value is LocationLink {
  let candidate = value as LocationLink;
  return Is.defined(candidate) && Range.is(candidate.targetRange) && Is.string(candidate.targetUri)
  - && (Range.is(candidate.targetSelectionRange) || Is.undefined(candidate.targetSelectionRange))
  + && Range.is(candidate.targetSelectionRange)
  && (Range.is(candidate.originSelectionRange) || Is.undefined(candidate.originSelectionRange));
  }
  }
  