Explain wontfix comments in Checkmjar

[xeno-by]

def loop(tpe: Type): Type = {
  tpe match {
    case NoType =>
      NoType
    case NoPrefix =>
      NoPrefix
    case ThisType(sym) =>
      // WONTFIX: https://github.com/twitter/rsc/issues/90
      val sym1 = NoSymbol
      ThisType(sym1)
    case SingleType(pre: Type, sym: Symbol) =>
      // WONTFIX: https://github.com/twitter/rsc/issues/90
      val pre1 = loop(normalizePrefix(pre))
      val sym1 = sym
      SingleType(pre1, sym1)
    case ConstantType(lit) =>
      val lit1 = lit
      ConstantType(lit1)
    case TypeRef(pre, sym, targs) =>
      // WONTFIX: https://github.com/twitter/rsc/issues/90
      val pre1 = loop(normalizePrefix(pre))
      val sym1 = sym
      val targs1 = targs.map(loop)
      TypeRef(pre1, sym1, targs1)
    ...
  }
}

[xeno-by]

Superseded by #243.