Adds more coverage for function entry hook, sufficient to capture profiles that are contiguous from C++, through JS and back out to C++.

R=danno@chromium.org

Review URL: https://codereview.chromium.org/16578008

Patch from Sigurður Ásgeirsson <siggi@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15361 ce2b1a6d-e550-0410-aec6-3dcde31c8c00