[bug#38612] Pass system and target arguments to gexp->file.

[Mathieu Othacehe]

Hey,

> In general, in monadic code, we should refer to (current-system) and
> (current-target-system), not to the SRFI-39 parameters.

Ok!

> By default, ‘gexp->file’ now uses the current system and target, so this
> change shouldn’t be necessary if you just want to use those.  Am I
> missing something?

Well turns out that gexp->file takes #f as default target (as
gexp->script and lower-object).

Using %current-target-system as default target argument (as gexp->sexp)
makes those two patches useless.

Would you have any objection to use %current-target-system as default
target argument in gexp->file and lower-object?

Thanks,

Mathieu