In rare cases GC could be called from ComputeCallMiss function thus
breaking CallIC::LoadFunction.

Review URL: http://codereview.chromium.org/3047027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5174 ce2b1a6d-e550-0410-aec6-3dcde31c8c00