it's easier to inline the code on demand. Right now, we still
only inline the smi case code for bitwise operations.
Review URL: http://codereview.chromium.org/7669

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@547 ce2b1a6d-e550-0410-aec6-3dcde31c8c00