Move constants from dir.c to stub file

[haszi]

Moves registering some constant from dir.c to its corresponding stub file with four constant registrations remaining in dir.c.

@kocsismate pinging you as this is a stub file change as well.

[kocsismate]

Very nice catch, I'm not sure why I didn't put these constants into stub! Thanks for the PR!

[haszi]

Very nice catch, I'm not sure why I didn't put these constants into stub! Thanks for the PR!

There are a few more of these that I think could be moved to a stub file. I'll open a PR for these today or tomorrow.
Additionally, there are ~20-25 constants whose values are evaluated during runtime. It might be a hack but if gen_stub.php could generate separate functions for these (as opposed to putting them in e.g. register_dir_symbols with the rest of the constants) then all constants could easily be moved to stub files.

I used the below command to list all the remaining constants not registered in stub files.
grep -rE --exclude=*.{php,md} --exclude={*arginfo.h,zend_constants.h} 'REGISTER_(.+)_CONSTANT'

[kocsismate]

LGTM, I had only 2 small nits. I'll merge the PR once these are resolved ) Thanks for your work!