Tool(Builder &b, const std::string &t): Tool(b, 0, t) { }
Tool(Builder &b, const Architecture *a, const std::string &t): builder(b), architecture(a), tag(t) { }
Tool(Builder &b, const std::string &t): Tool(b, 0, t) { }
Tool(Builder &b, const Architecture *a, const std::string &t): builder(b), architecture(a), tag(t) { }