Use ExpressionClassifier to identify valid arrow function formals

src/parser.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_PARSER_H_
 #define V8_PARSER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/compiler.h"  // TODO(titzer): remove this include dependency
@@ skipping 742 matching lines @@
       // TODO(sigurds) Mark every parameter as maybe assigned. This is a
       // conservative approximation necessary to account for parameters
       // that are assigned via the arguments array.
       var->set_maybe_assigned();
     }
     return is_duplicate;
   }
 
   void DeclareArrowFunctionParameters(Scope* scope, Expression* expr,
                                       const Scanner::Location& params_loc,
-                                      FormalParameterErrorLocations* error_locs,
+                                      Scanner::Location* duplicate_loc,
                                       bool* ok);
-  void ParseArrowFunctionFormalParameters(
-      Scope* scope, Expression* params, const Scanner::Location& params_loc,
-      FormalParameterErrorLocations* error_locs, bool* is_rest, bool* ok);
+  void ParseArrowFunctionFormalParameters(Scope* scope, Expression* params,
+                                          const Scanner::Location& params_loc,
+                                          bool* is_rest,
+                                          Scanner::Location* duplicate_loc,
+                                          bool* ok);
 
   // Temporary glue; these functions will move to ParserBase.
   Expression* ParseV8Intrinsic(bool* ok);
   FunctionLiteral* ParseFunctionLiteral(
       const AstRawString* name, Scanner::Location function_name_location,
       bool name_is_strict_reserved, FunctionKind kind,
       int function_token_position, FunctionLiteral::FunctionType type,
       FunctionLiteral::ArityRestriction arity_restriction, bool* ok);
   V8_INLINE void SkipLazyFunctionBody(
       int* materialized_literal_count, int* expected_property_count, bool* ok,
@@ skipping 401 matching lines @@
 }
 
 
 Expression* ParserTraits::SpreadCallNew(
     Expression* function, ZoneList<v8::internal::Expression*>* args, int pos) {
   return parser_->SpreadCallNew(function, args, pos);
 }
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_