[MLton] FreeBSD port broken, FIX, and a hello again note

[Matthew Fluet]

> Currently, the FreeBSD port is broken. This is due to an upgrade of
> libgmp so it bumps from .so.6 --> .so.7. The bootstrap file is not
> statically linked, so it borks on the missing libgmp.so.6.
>
> The fix is to note that you do not need libgmp at all inside mlton, so
> by symlinking .so.7 to .so.6, the compile goes through effortlessly.
> I've tested a binary compiled like this on the regressions and it goes
> through without any kind of error.

I don't think that it is true that 'you do not need libgmp at all inside 
mlton.'  All numeric constants are represented by IntInf.int in the 
compiler, so I'd be very surprised that a self-compile never calls a 
libgmp function.  We use only documented APIs of libgmp, so I'm not 
surprised that we see no functional difference between successive 
versions.