[MLton] MLNLFFI doesn't link on MinGW(?)

[Vesa Karvonen]

Quoting Vesa Karvonen <vesa.karvonen at cs.helsinki.fi>:
[...]
> I would guess that the reason why the SML/NJ implementation uses the dl*
> functions to obtain malloc and free is that it is the only way (in SML/NJ).

I browsed the SML/NJ code a bit and my guess was incorrect.  You can call
C stuff from SML/NJ by writing stubs (of course!), but using the dl* stuff
is perhaps slightly easier (and then you don't have to write C code, which
is a huge benefit ;-).

I still think that it would be better if the MLton version would just use
the MLton FFI to import malloc & free.

-Vesa Karvonen