[racket] How to create Linux AMD64 installer from source?

This is probably mostly addressed to Eli, but sent through the list
for posterity's sake.

I have a few 64-bit servers that I need to install Racket on when new
versions come out. I've been using the i386 installer, but would like
to avoid installing the 32-bit compatibility packages, if I can.

Building from source takes a long time, but I'm guessing that there's
a target in the Makefile that can build the installer, which i can
then run on each of the servers.

Assuming I've downloaded the source and all the dependencies, how
would I do that?

Todd