the implementation but still lives on in comments and identifier
names.

Where it was used, it has been changed to "caller's stack pointer".
Review URL: http://codereview.chromium.org/118500

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2137 ce2b1a6d-e550-0410-aec6-3dcde31c8c00