Allow lexically declared "arguments" in function scope in sloppy mode.

src/ast/scopes.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_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/ast/ast.h"
 #include "src/base/hashmap.h"
 #include "src/globals.h"
@@ skipping 605 matching lines @@
     DCHECK(scope_info_.is_null());
     scope_info_ = scope_info;
   }
 
   bool asm_module() const { return asm_module_; }
   void set_asm_module() { asm_module_ = true; }
   bool asm_function() const { return asm_function_; }
   void set_asm_function() { asm_module_ = true; }
 
   void DeclareThis(AstValueFactory* ast_value_factory);
+  void DeclareArguments(AstValueFactory* ast_value_factory);
   void DeclareDefaultFunctionVariables(AstValueFactory* ast_value_factory);
 
   // This lookup corresponds to a lookup in the "intermediate" scope sitting
   // between this scope and the outer scope. (ECMA-262, 3rd., requires that
   // the name of named function literal is kept in an intermediate scope
   // in between this scope and the next outer scope.)
   Variable* LookupFunctionVar(const AstRawString* name);
 
   // Declare the function variable for a function literal. This variable
   // is in an intermediate scope between this function scope and the the
@@ skipping 206 matching lines @@
   void AllocateModuleVariables();
 
  private:
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_