parameters.  This could case the initial value to be lost or worse, a
crash.

Fix by handling the case of a declaration shadowing both
stack-allocated parameters and those in the arguments object.

This is related to V8 issue 540.
http://code.google.com/p/v8/issues/detail?id=540

BUG=29565
Review URL: http://codereview.chromium.org/469006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3429 ce2b1a6d-e550-0410-aec6-3dcde31c8c00