Add support for index properties with getters, setters or indexed interceptors.

For indexed interceptor case only fix crashes, do not guarantee any semantic soundness. Separate issue opened for this http://code.google.com/p/v8/issues/detail?id=877

BUG=http://code.google.com/p/v8/issues/detail?id=874

Review URL: http://codereview.chromium.org/3462005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5512 ce2b1a6d-e550-0410-aec6-3dcde31c8c00