[parser] Only log messages using the pending error handling

src/pending-compilation-error-handler.h

 // Copyright 2015 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_PENDING_COMPILATION_ERROR_HANDLER_H_
 #define V8_PENDING_COMPILATION_ERROR_HANDLER_H_
 
 #include "src/base/macros.h"
 #include "src/globals.h"
 #include "src/handles.h"
@@ skipping 57 matching lines @@
     message_ = message;
     char_arg_ = nullptr;
     arg_ = nullptr;
     handle_arg_ = arg;
     error_type_ = error_type;
   }
 
   bool has_pending_error() const { return has_pending_error_; }
 
   void ThrowPendingError(Isolate* isolate, Handle<Script> script);
+  Handle<String> FormatMessage(Isolate* isolate);
 
  private:
+  Handle<String> ArgumentString(Isolate* isolate);
+
   bool has_pending_error_;
   int start_position_;
   int end_position_;
   MessageTemplate::Template message_;
   const AstRawString* arg_;
   const char* char_arg_;
   Handle<String> handle_arg_;
   ParseErrorType error_type_;
 
   DISALLOW_COPY_AND_ASSIGN(PendingCompilationErrorHandler);
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_PENDING_COMPILATION_ERROR_HANDLER_H_