Possible to attempt to build for X64.
Build will be unsuccessful, since all x64 source files are
missing and pointers are reinterpreted as integers everywhere.

Review URL: http://codereview.chromium.org/99186


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1817 ce2b1a6d-e550-0410-aec6-3dcde31c8c00