message: Implement printer cases for TSUnknownKeyword, TSRestType, and TSOptionalType.
diff: @@ -1832,6 +1832,9 @@ function genericPrintNoParens(path, options, print) {
  case "TSUndefinedKeyword":
  return fromString("undefined", options);
  + case "TSUnknownKeyword":
  + return fromString("unknown", options);
  +
  case "TSNeverKeyword":
  return fromString("never", options);
  @@ -1915,6 +1918,19 @@ function genericPrintNoParens(path, options, print) {
  "]"
  ]);
  + case "TSRestType":
  + return concat([
  + "...",
  + path.call(print, "typeAnnotation"),
  + "[]"
  + ]);
  +
  + case "TSOptionalType":
  + return concat([
  + path.call(print, "typeAnnotation"),
  + "?"
  + ]);
  +
  case "TSIndexedAccessType":
  return concat([
  path.call(print, "objectType"),
  