Optional arguments in new compiler.

runtime/vm/code_generator_x64.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_CODE_GENERATOR_X64_H_
 #define VM_CODE_GENERATOR_X64_H_
 
 #ifndef VM_CODE_GENERATOR_H_
 #error Do not include code_generator_x64.h directly; use code_generator.h.
 #endif
@@ skipping 204 matching lines @@
   void HandleBackwardBranch(intptr_t loop_id, intptr_t token_index);
 
   void ErrorMsg(intptr_t token_index, const char* format, ...);
 
   int generate_next_try_index() { return try_index_ += 1; }
 
   void MarkDeoptPoint(intptr_t node_id, intptr_t token_index);
   void AddCurrentDescriptor(PcDescriptors::Kind kind,
                             intptr_t node_id,
                             intptr_t token_index);
+  void CopyParameters();
 
   Assembler* assembler_;
   const ParsedFunction& parsed_function_;
   intptr_t locals_space_size_;
   CodeGeneratorState* state_;
   DescriptorList* pc_descriptors_list_;
   HandlerList* exception_handlers_list_;
   int try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeGenerator);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_CODE_GENERATOR_X64_H_