This is a port to x64 of the following CLs:

http://codereview.chromium.org/554062 (use registers at all)
http://codereview.chromium.org/555098 (use registers for MUL, DIV and virtual frames)
http://codereview.chromium.org/556019 (optimize register order)

Review URL: http://codereview.chromium.org/555147

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3735 ce2b1a6d-e550-0410-aec6-3dcde31c8c00