doesn't time out on our slowest platforms.  It turns out that almost
all the time was spent in Array.prototype.unshift on a non-array with
a length-field holding 40000.  We may want to look into that but on
the other hand it is a pretty obscure thing to do so we may not.


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1211 ce2b1a6d-e550-0410-aec6-3dcde31c8c00