[parser] report errors for invalid binding patterns in async formal parameters

src/parsing/expression-classifier.h

Index: src/parsing/expression-classifier.h
diff --git a/src/parsing/expression-classifier.h b/src/parsing/expression-classifier.h
index 8e13d0e503756a4c841919348590e7abb302e31d..9e689aecbf854cbd5d3da022c89d1ab86c96d8a5 100644
--- a/src/parsing/expression-classifier.h
+++ b/src/parsing/expression-classifier.h
@@ -250,6 +250,19 @@ class ExpressionClassifier {
     Add(Error(loc, message, kBindingPatternProduction, arg));
   }
 
+  void ReplaceBindingPatternError(const Scanner::Location& loc,
+                                  MessageTemplate::Template message,
+                                  const char* arg = nullptr) {
+    if (!is_valid_binding_pattern()) {
+      Error& e = reported_error(kBindingPatternProduction);
+      e.location = loc;
+      e.message = message;
+      e.arg = arg;
+    } else {
+      RecordBindingPatternError(loc, message, arg);
+    }
+  }
+
   void RecordAssignmentPatternError(const Scanner::Location& loc,
                                     MessageTemplate::Template message,
                                     const char* arg = nullptr) {