[parser] better error message for generator constructors

src/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/v8.h"
 
 #include "src/bailout-reason.h"
@@ skipping 3088 matching lines @@
   if (property == Token::SMI || property == Token::NUMBER) return;
 
   if (is_static) {
     if (IsPrototype()) {
       this->parser()->ReportMessage("static_prototype");
       *ok = false;
       return;
     }
   } else if (IsConstructor()) {
     if (is_generator || type == kAccessorProperty) {
-      this->parser()->ReportMessage("constructor_special_method");
+      const char* msg =
+          is_generator ? "constructor_is_generator" : "constructor_is_accessor";
+      this->parser()->ReportMessage(msg);
       *ok = false;
       return;
     }
     if (has_seen_constructor_) {
       this->parser()->ReportMessage("duplicate_constructor");
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H