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

[jakub at gcc dot gnu.org]

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

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Because without the -dD implicitly added for -g3 the -g3 option can't work as
documented, in particular record the macros in the debug information.  Because
they would be irrecoverably lost during the preprocessing phase.