message: make \b an escape character
diff: @@ -184,14 +184,9 @@ export const createRegExpParser = createParser(
  value: '\f',
  }, end);
  - case 'b':
  - return this.finishComplexToken('Character', {
  - escaped: false,
  - value: '\b',
  - }, end);
  -
  case 'd':
  case 'D':
  + case 'b':
  case 'B':
  case 's':
  case 'S':
  