[Bug fortran/95146] gfortran -cpp – leading spaces before '#' preprocessing directive not handled

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95146

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Pre ANSI/ISO C (aka K&R C), preprocessor were true preprocessor and always
required # in the first column.

I think meson should be fixed really to work rather than working around the
issue in gfortran.