Fix some bit op bugs introduced last week on IA32:
http://code.google.com/p/chromium/issues/detail?id=52096
Review URL: http://codereview.chromium.org/3151017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5273 ce2b1a6d-e550-0410-aec6-3dcde31c8c00