[MLton] Port to HP-UX/IA64 done

[Ville Laurikari]

I've ported trunk to HP-UX 11.23 IA64, and things seem to work.
Regression tests are currently running, so far so good.  I used GCC
4.2.1.  This is a 32-bit build.  I'm planning to get a 64-bit build
done as well, because that's what we would like to use if possible.

There were a few warnings like this in compiling the runtime:
  gc/cheney-copy.c:32: warning: cast increases required alignment of target type

It appears they cause no harm, or at least things seems to work
regardless of them.

In previous attempts I had trouble on IA64 with unaligned accesses to
gmp objects.  It appears these are now gone.  Perhaps they were fixed,
or maybe it was because previously I was going for a 64-bit build
directly.

The only real change I did was to set default alignment to 8 on IA64.
I'll commit and upload some binaries on the Experimental page at some
point.

--
http://www.iki.fi/vl/