For some reason the StackGuard runtime function took a dummy argument
that it always ignored.  Change it to take no arguments.

Review URL: http://codereview.chromium.org/3838003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5660 ce2b1a6d-e550-0410-aec6-3dcde31c8c00