Add generated code to calculate Math.log and to search Transcendental cache for logs.  Implemented on all platforms.
Review URL: http://codereview.chromium.org/5437002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5912 ce2b1a6d-e550-0410-aec6-3dcde31c8c00