Allow long-form --debug-info option

[eschnett]

The Julia executable allows long-form options (e.g. --optimize) for almost all options. Noticeably missing is a long-form option for -g, and this somehow rubs me the wrong way.

This PR adds long-form options for the two missing cases, --debug and --interactive.

[PallHaraldsson]

I've never used debug, i.e. -g, but I would like a debug option with some specific other changes, so maybe hold on on --debug? I see -d isn't used, not sure why -g was chosen, was it intentional to not conflict with a later --debug (and -d) option?

[KristofferC]

Yes, imo we should save --debug for a Julia debug option, e.g. #37874

--debug for assertion mode

[eschnett]

The option is likely called -g because this is the commonly used option name used by Fortran/C/C++ compilers, probably because -d and -D were already taken there. That's probably also the reason that the optimization level is set via an upper case -O.

[eschnett]

I renamed the option to --debuginfo.

[eschnett]

@KristofferC Do you approve if the long name of the -g option is --debuginfo?

[StefanKarpinski]

I think --debug-info would be more in line with other options.