failure

[Matthew Fluet]

> Yikes: MAKECMDGOALS, what a hack.
> Note, this will fail if the person does
> 	make some-target mlyacc.cm some-other-target
> and the like.

Well, I'm open to other suggestions.  See my previous e-mail for "what I
want".  I think this hack is o.k.; the ml*.cm files only need to be
rebuilt when we know they need to -- when sources are added or deleted to
some sources.cm file.  So, make ml*.cm just corresponds to the step when
you would update the Makefile to reflect these new dependencies.