[es6] Fix parsing of expressions in parameter lists

src/expression-classifier.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_EXPRESSION_CLASSIFIER_H
 #define V8_EXPRESSION_CLASSIFIER_H
 
 #include "src/v8.h"
 
 #include "src/messages.h"
@@ skipping 207 matching lines @@
     // As an exception to the above, the result continues to be a valid arrow
     // formal parameters if the inner expression is a valid binding pattern.
     if (productions & ArrowFormalParametersProduction &&
         is_valid_arrow_formal_parameters() &&
         !inner.is_valid_binding_pattern()) {
       invalid_productions_ |= ArrowFormalParametersProduction;
       arrow_formal_parameters_error_ = inner.binding_pattern_error_;
     }
   }
 
-  void AccumulateReclassifyingAsPattern(const ExpressionClassifier& inner) {
-    Accumulate(inner, AllProductions & ~PatternProductions);
-    if (!inner.is_valid_expression()) {
-      if (is_valid_binding_pattern()) {
-        binding_pattern_error_ = inner.expression_error();
-      }
-      if (is_valid_assignment_pattern()) {
-        assignment_pattern_error_ = inner.expression_error();
-      }
-    }
-  }
-
  private:
   unsigned invalid_productions_;
   Error expression_error_;
   Error binding_pattern_error_;
   Error assignment_pattern_error_;
   Error arrow_formal_parameters_error_;
   Error duplicate_formal_parameter_error_;
   Error strict_mode_formal_parameter_error_;
   Error strong_mode_formal_parameter_error_;
   DuplicateFinder* duplicate_finder_;
 };
 }
 }  // v8::internal
 
 #endif  // V8_EXPRESSION_CLASSIFIER_H