[MLton] interrupted system call

[Stephen Weeks]

> I  thought  about  it a bit and definitely came to the conclusion that system
> calls not being interruptable is quite bad.   The  canonical  case  would  be
> where I have created some tmp files some where, so I want to catch SIGINT and
> SIGHUP so that I can clean up.  If I am reading from a device or a human, now
> hitting control-C will do nothing.

Is the Signal.restart flag good enough for what you want?  It seems
like it to me.