build(antlr): 引入第三方 ANTLR4 runtime/tool 并接入构建

third_party/antlr4-runtime-4.13.2/runtime/src/atn/DecisionState.cpp

@@ -0,0 +1,12 @@
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#include "atn/DecisionState.h"
+
+using namespace antlr4::atn;
+
+std::string DecisionState::toString() const {
+  return ATNState::toString();
+}