[cvs-nhc98] merging nhc98 and yhc

[Malcolm Wallace]

To Yhc/nhc98 people,

I have just re-merged the sources for the compiler98 directory across
our two projects, so that we can share development in the future.
Sadly, it does involve a loss of some VC history (from the yhc side),
but since yhc already lost VC history a couple of times in the past, I
judged that wasn't too critical.

So the plan is this:  both nhc98 and yhc projects should delete their
current
    src/compiler98
and pickup a new one from
    darcs get [--partial] --repo-name=src/compiler98 \
          http://darcs.haskell.org/york-compiler98
adjusting their darcs-all/scons scripts accordingly.

The only major difference you should notice is that yhc's former Main.hs
is now called MainYhc.hs (and likewise, nhc98's MainNew.hs becomes
MainNhc98.hs).  Any other regressions are a bug.  I'm expecting
_something_ to break, since there were 2693 diffs to merge, but the
result looks a whole lot more like yhc than like nhc98, and hopefully we
can find and fix mistakes quite easily.

Oh, and someone from yhc might want to keep a version of their repo with
the existing unshared compiler98, just to diff against.  You might want
to check what I've done anyway, or it might help debug some regressions.

Note that the _only_ sources now shared between nhc98 and yhc are for
the compiler itself - the runtime, libraries, tools, etc. are all
entirely different and unshareable.

A subsequent stage of the plan will be for other projects that partially
use nhc98 as a front-end to share this merged compiler too: namely, Hat,
and HPC.

Regards,
    Malcolm