Retry "Templatise type representation" after making clang happy

The only thing different now is line types.h:208/236, which had a static_cast<Type*> before.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/133683002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18533 ce2b1a6d-e550-0410-aec6-3dcde31c8c00