[MLton] cygwoes

[Matthew Fluet]

>>> Unfortunately, all this suggests that there is a lot more broken
>>> under the current version of Cygwin than just the virtual memory
>>> management.
>> 
>> I'm not so sure.  Keep in mind that all the regressions pass when run
>> with use-mmap.  With your fix of gc.c line 1319, do all the
>> regressions pass even without use-mmap?
>
> I can't even get a working compiler on Cygwin, even with the change to line 
> 1319 of gc.c.
>
> If I set UseMmap to FALSE, then I don't get the VirtualFree error 
> (obviously), I _do_ get the lowercase error, and I don't get the gcc/signal 
> error or the gcc/"No child process" error.

The lowercase error seems to be because I had  check_case:strict  in my 
CYGWIN environment variable.