These are not needed after #35129 but making uncrustify still play nice
with them was a bit tricky.
Unfortunately `uncrustify --update-config-with-doc` breaks strings
with backslashes. This issue has been reported upstream,
and in the meanwhile auto-update on every single run has been disabled.
This type itself is not eval-specific. Moving it to types.h can avoid
including eval/funcs.h in many headers, and types.h is already included
by many headers.
