Also, add test that assignment to function name is a syntax error with harmony scoping.

Does not fix issue 2243 directly, but with ES6, the required behaviour will change to what is implemented already anyway.

R=yangguo@chromium.org
BUG=v8:2243

Review URL: https://codereview.chromium.org/11607016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13234 ce2b1a6d-e550-0410-aec6-3dcde31c8c00