Mark optimized modulo and memcpy code pages -w after writing them.

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/7563006

git-svn-id: http://v8.googlecode.com/svn/branches/3.4@8808 ce2b1a6d-e550-0410-aec6-3dcde31c8c00