Merge r8774 from bleeding edge to 3.4 branch.

Merge r8774 from bleeding edge to 3.4 branch.

Check for phi-uses of arguments object before eliminating dead phi's.

HGraphBuilder::TryArgumentsAccess does not emit any uses for receiver and will
generate incorrect code when receiver for a property access is defined by a phi
that returns either arguments object or something else.

BUG=v8:1582
TEST=test/mjsunit/regress/regress-1582.js
Committed: http://code.google.com/p/v8/source/detail?r=8775

[Kevin Millikin (Chromium), 2011-08-02 10:45:01]

LGTM.