Port r8876 (2aeeae7)

Original commit message:
Harmony is intended to make typeof null === "null". This may
break existing programs. Implementing it will allow us to run
some tests on the actual web.

BUG=
TEST=

Review URL: http://codereview.chromium.org/7650009
Patch from Paul Lind <plind44@gmail.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8939 ce2b1a6d-e550-0410-aec6-3dcde31c8c00