[es6] Fix parsing of expressions in parameter lists

src/expression-classifier.h

Index: src/expression-classifier.h
diff --git a/src/expression-classifier.h b/src/expression-classifier.h
index fc89015d1fcee8a8f88cbb20169476cb523b14b1..716d4c7a3f29c24d2da337721c9089c4c3273616 100644
--- a/src/expression-classifier.h
+++ b/src/expression-classifier.h
@@ -225,18 +225,6 @@ class ExpressionClassifier {
     }
   }
 
-  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_;