When optimizing a function defined inside a catch, we did not count
the catch context as part of the context chain.

R=vegorov@chromium.org
BUG=1521
TEST=regress-1521

Review URL: http://codereview.chromium.org/7285032

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8518 ce2b1a6d-e550-0410-aec6-3dcde31c8c00