[MLton] x86-64 merge?

[Matthew Fluet]

> I think we should merge the x86-64 branch into the trunk.  It works
> fine on almost all of our platforms, and we are just causing problems
> by having it as a separate branch, as well as extra work porting
> patches between branches.  We're also missing out on getting some more
> testing from people who live in the trunk.
>
> Thoughts?

I don't have any strong reasons not to merge the branch.  I don't 
think that it is feasible to finish the x86-64 port without going through 
a period where the build is broken (that is, I prefer to checkpoint 
incomplete progress), so I would like to keep (or re-branch) the x86-64 
branch.  On the other hand, it isn't very hard to merge revisions on trunk 
into the branch; I haven't done so recently since I didn't think there 
were many critical revisions.  Also, I was hoping that someone could 
verify the x86-darwin port.