Teach C++ ArraySlice builtin to deal with arguments object.

Teach C++ ArraySlice builtin to deal with arguments object.

Array.prototype.slice.call(arguments, ...) idiom is pretty common (up to 97% of invocations
in GMail), so we'd better handle it efficiently too.

Committed: http://code.google.com/p/v8/source/detail?r=6085

[antonm, 2010-12-20 11:52:54]

Anders and Mads,

here comes another try.

BTW, there is slight inefficiency in Array.slice (and probably
Array.splice)---we are fine with COW elements for Array.slice and some cases of
splice.

I'll fix it with a next CL.

[Mads Ager (chromium), 2010-12-20 13:52:57]

LGTM!