[PATCH, Fortran] Correctly set -fd-lines-as-comments with -fdec

[Thomas Koenig]

Hi Fritz,

> This is a simple patch. The original intent was for -fdec to set
> -fd-lines-as-comments by default if flag_d_lines was unspecified by
> the user. However, currently flag_d_lines is interrogated in
> set_dec_flags(), usually before its final value is determined. The
> attached patch fixes this behavior to work as intended.
> 
> Any objections for trunk? If not I think it is safe to commit.

Did you regression-test?  OK for trunk if yes.

Regards

	Thomas