According to the ES5 spec the implementation of DefineOwnProperty() has
to special case handling of arrays. This implementation correctly
handles definitions of array index properties and redefinitions of the
length property.

R=svenpanne@chromium.org
BUG=v8:1756
TEST=test262

Review URL: http://codereview.chromium.org/8776045

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10149 ce2b1a6d-e550-0410-aec6-3dcde31c8c00