Reland "In-object double fields unboxing (for 64-bit only)."

tools/gyp/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 676 matching lines @@
         '../../src/interface-descriptors.h',
         '../../src/interpreter-irregexp.cc',
         '../../src/interpreter-irregexp.h',
         '../../src/isolate.cc',
         '../../src/isolate.h',
         '../../src/json-parser.h',
         '../../src/json-stringifier.h',
         '../../src/jsregexp-inl.h',
         '../../src/jsregexp.cc',
         '../../src/jsregexp.h',
+        '../../src/layout-descriptor-inl.h',
+        '../../src/layout-descriptor.cc',
+        '../../src/layout-descriptor.h',
         '../../src/list-inl.h',
         '../../src/list.h',
         '../../src/lithium-allocator-inl.h',
         '../../src/lithium-allocator.cc',
         '../../src/lithium-allocator.h',
         '../../src/lithium-codegen.cc',
         '../../src/lithium-codegen.h',
         '../../src/lithium.cc',
         '../../src/lithium.h',
         '../../src/lithium-inl.h',
@@ skipping 1031 matching lines @@
         }],
         ['v8_compress_startup_data=="bz2"', {
           'libraries': [
             '-lbz2',
           ]
         }],
       ],
     },
   ],
 }