new codegen

[Henry Cejtin]

In the hedings it says

    mlton           == new codegen, -native-live-stack true
    mlton-stable    == mlton-20010806
    mlton-old       == new codegen, -native-live-stack false

I  take  this to mean that the new stuff is `mlton' and `mlton-old', with the
old stuff being `mlton-stable'.  (The ordering is rather crazy,  as  are  the
names.)

The relevant part of the run time table is

    benchmark         MLton stable MLton old MLton
    tailfib            16.7         25.1      19.9

Now  if it is just a matter of adding dashes, then the first number is MLton-
stable, the second is MLton-old and the third is MLton.  The inconsistency is
between  the  `mlton-stable' and `stable MLton'.  Adding a dash in the latter
is better, but changing the order between the modifier and the noun  is  bad.
Pick one or the other.  I don't care which, but changing them seems goofy.