[Bug debug/97989] -g3 somehow breaks -E

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97989

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
It will allow -g0 at the end to override the earlier -g3 and not add -dD in
that case.