Merge r8780, r8803 from the bleeding edge 3.4 branch.

Merge r8780, r8803 from the bleeding edge 3.4 branch.

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.
Committed: http://code.google.com/p/v8/source/detail?r=8808

[Kevin Millikin (Chromium), 2011-08-03 11:01:07]

LGTM.