[heap] Extract marking deque to separate file.

src/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 967 matching lines @@
         'heap/objects-visiting-inl.h',
         'heap/objects-visiting.cc',
         'heap/objects-visiting.h',
         'heap/page-parallel-job.h',
         'heap/remembered-set.h',
         'heap/scavenge-job.h',
         'heap/scavenge-job.cc',
         'heap/scavenger-inl.h',
         'heap/scavenger.cc',
         'heap/scavenger.h',
+        'heap/sequential-marking-deque.cc',
+        'heap/sequential-marking-deque.h',
         'heap/slot-set.h',
         'heap/spaces-inl.h',
         'heap/spaces.cc',
         'heap/spaces.h',
         'heap/store-buffer.cc',
         'heap/store-buffer.h',
         'intl.cc',
         'intl.h',
         'icu_util.cc',
         'icu_util.h',
@@ skipping 1493 matching lines @@
         }],
         ['want_separate_host_toolset==1', {
           'toolsets': ['host'],
         }, {
           'toolsets': ['target'],
         }],
       ],
     },
   ],
 }