This change fixes an assert we hit when we recognized a fast smi loop
with a parameter as the loop variable.

BUG=650


Review URL: http://codereview.chromium.org/1138003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4202 ce2b1a6d-e550-0410-aec6-3dcde31c8c00