This introduces a new rule in our codebase, that any file that #includes
actorcompiler.h needs to do it as the last #include, and it needs to
then #include unactorcompiler.h at the end of the file.
The point of this is that it prevents our actorcompiler.h #defines from
leaking into boost or the c++ standard library. Both of these start
throwing errors if you s/state// their code, which `#define state `
effectively does.