regular expressions to be consistent with typeof in other contexts.
Typeof regular expressions should now be 'function' in all contexts.

In the JS natives, IS_FUNCTION, IS_OBJECT, and IS_REGEXP return the
same answers as before.

Review URL: http://codereview.chromium.org/360053

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3231 ce2b1a6d-e550-0410-aec6-3dcde31c8c00