Check phi uses of the arguments object after redundant phies elimination.

This allows to handle code like:

var a = arguments;
while (smth) a[i];

without bailout.
Review URL: http://codereview.chromium.org/7562007

git-svn-id: http://v8.googlecode.com/svn/branches/3.3@8806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00