Extend assembler with ability to produce comments for the generated code.

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 23 matching lines @@
 
   // Add pc descriptors to code.
   void FinalizePcDescriptors(const Code& code) { UNIMPLEMENTED(); }
 
   // Add stack maps to code.
   void FinalizeStackmaps(const Code& code) { UNIMPLEMENTED(); }
 
   // Add local variable descriptors to code.
   void FinalizeVarDescriptors(const Code& code) { UNIMPLEMENTED(); }
 
+  void FinalizeComments(const Code& code) { UNIMPLEMENTED(); }
+
   // Allocate and return an arguments descriptor.
   // Let 'num_names' be the length of 'optional_arguments_names'.
   // Treat the first 'num_arguments - num_names' arguments as positional and
   // treat the following 'num_names' arguments as named optional arguments.
   static const Array& ArgumentsDescriptor(
       int num_arguments,
       const Array& optional_arguments_names);
 
   // Return true if the VM may optimize functions.
   static bool CanOptimize();
 
  private:
   // Forward declarations.
   class DescriptorList;
 
   DescriptorList* pc_descriptors_list_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeGenerator);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_CODE_GENERATOR_X64_H_