I found this while doing the JFR compiler events and getting a nasty include conflict. Pushing this as its own change so I at least get one commit for my JFR work.
Removing include of c1/c1_runtime.hpp and opto/runtime.hpp from all os-files. I have no clue why they were there but they obviously aren't needed anymore. And it feels right that the os-files aren't including the entire compilers anymore.