message: turns out including postgres.h is a no-no
diff: #include "parser/tokens.hpp"
  namespace postgres {
  -#include "postgres.h"
  -#include "pg_query.h"
  +typedef uintptr_t Datum;
  +#include "c.h"
  #include "nodes/parsenodes.h"
  +#include "pg_query.h"
  #include "catalog/pg_trigger.h"
  } // namespace postgres
  