not point into the middle of the handler.  Also remove top-of-stack
caching from MacroAssembler::PushTryHandler.

Review URL: http://codereview.chromium.org/119358

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2128 ce2b1a6d-e550-0410-aec6-3dcde31c8c00