Refactor formal parameter error locations into a class

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 737 matching lines @@
   }
   ZoneList<const v8::internal::AstRawString*>* NewFormalParameterList(
       int size, Zone* zone) {
     return new (zone) ZoneList<const v8::internal::AstRawString*>(size, zone);
   }
   V8_INLINE Scope* NewScope(Scope* parent_scope, ScopeType scope_type,
                             FunctionKind kind = kNormalFunction);
 
   // Utility functions
   int DeclareArrowParametersFromExpression(Expression* expression, Scope* scope,
-                                           Scanner::Location* undefined_loc,
-                                           Scanner::Location* dupe_loc,
+                                           FormalParameterErrorLocations* locs,
                                            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(const AstRawString* name,
@@ 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_