message: Remove a pointless const
  Having the extra const makes no sense on an r-value and makes GCC8
  unhappy.
diff: @@ -761,7 +761,7 @@ struct rdcstr : public rdcarray<char>
  return !strcmp(elems, o);
  }
  bool operator==(const std::string &o) const { return o == elems; }
  - bool operator==(const rdcstr &o) const { return *this == (const char *const)o.elems; }
  + bool operator==(const rdcstr &o) const { return *this == (const char *)o.elems; }
  bool operator!=(const char *const o) const { return !(*this == o); }
  bool operator!=(const std::string &o) const { return !(*this == o); }
  bool operator!=(const rdcstr &o) const { return !(*this == o); }
  