ml.lex/ml.grm

[Stephen Weeks]

> We could add dependencies in the Makefile that force ml.lex.sml and
> ml.grm.sig/ml.grm.sml to be compiled with the MLton versions of mllex and
> mlyacc before doing the call to smlnj.  

I added the appropriate dependencies to src/mlton/Makefile.  

> Of course, this still leaves a chicken-and-the-egg problem (from the point
> of view of a "fresh" compile): you need a MLton to produce mllex and
> mlyacc and you need mllex and mlyacc to produce a MLton.

I don't think this is a big deal, since we're going to require people to install 
the binary rpm in order to rebuild MLton anyways.

> I don't see the chicken-and-egg problem in this case.  Won't SML/NJ compile
> the MLton versions of ml.lex.sml?  

Yes.