[MLton] upcoming release

[Stephen Weeks]

> I noticed that a number of the profiling options are listed as
> expert and wondered whether any should be migrated to normal.
>
> The expert options are:
>   profile-c <regexp>
>   profile-exclude <regexp>
>   profile-include <regexp>
>   profile-raise {false|true}

It seems like complexity that people haven't been clamoring for, so I
lean toward keeping them as Expert.  We can always answer questions
and point people to them if needed.  But I don't feel strongly.  I've
barely ever used these.

> Also, -target-link-opt has kind of an odd description: why is
> dependent on the os and not on the target?

History only, I believe.  It has only ever been used with OS's.  Let's
expand the docs.  I'd leave in the list of OS's and add a list of
valid Arch's

> Also, why list -target-link-opt and not -target-cc-opt?

No good reason.  I think -target-{as,cc}-opt came later and so we put
them in as expert options.  I'm happy enough with both of them
becoming normal and being documented on CompileTimeOptions.  We've
used them for long enough.  Plus both are used in mlton-script.

> Finally, -basis has been deprecated through the last release; is it
> time to drop it?

Yes -- our usually policy is to drop something in the release
following the release in which it was deprecated.  Especially when it
is easy to replace its use (as it is with MLBs in this case).