Revert "In-object double fields unboxing (for 64-bit only)."
Revert "Fixes for Windows and Mac builds after r25250."
TBR=ishell@chromium.org

Review URL: https://codereview.chromium.org/699613004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25252 ce2b1a6d-e550-0410-aec6-3dcde31c8c00