Rewind additional parser state when reinterpreting arrow arguments

src/parser.h

Index: src/parser.h
diff --git a/src/parser.h b/src/parser.h
index fd24e8d4e952b4d33408f3fc03c0fcb83ec3bf43..b04f1dade12b38ea2110a7a28254d8283d34041c 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -339,6 +339,23 @@ class RegExpParser BASE_EMBEDDED {
 // ----------------------------------------------------------------------------
 // JAVASCRIPT PARSING
 
+
+class ParserCheckpoint BASE_EMBEDDED {
+ public:
+  template <typename Parser>
+  explicit ParserCheckpoint(Parser* parser) {
+    isolate_ = parser->zone()->isolate();
+    saved_ast_node_id_ = isolate_->ast_node_id();
+  }
+
+  void Restore() { isolate_->set_ast_node_id(saved_ast_node_id_); }
+
+ private:
+  Isolate* isolate_;
+  int saved_ast_node_id_;
+};
+
+
 class Parser;
 class SingletonLogger;
 
@@ -354,6 +371,7 @@ class ParserTraits {
     typedef v8::internal::Scope* ScopePtr;
     typedef Variable GeneratorVariable;
     typedef v8::internal::Zone Zone;
+    typedef ParserCheckpoint Checkpoint;
 
     typedef v8::internal::AstProperties AstProperties;
     typedef Vector<VariableProxy*> ParameterIdentifierVector;