Fix special handling of DefineOwnProperty on arrays.

Fix special handling of DefineOwnProperty on arrays.

According to the ES5 spec the implementation of DefineOwnProperty() has
to special case handling of arrays. This is a preliminary implementation
correctly handling definition of array index properties, defining length
properties is not completely covered yet.

R=rossberg@chromium.org
TEST=test262

Review URL: http://codereview.chromium.org/8221002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9596 ce2b1a6d-e550-0410-aec6-3dcde31c8c00