These are regression tests for the Diderot compiler.  Each test lives in its
own directory under rtest/tests, data files live in the rtest/data directory.
Each test should have a sample output called "correct.nrrd" and a script
to assess the correctness of the output "assess.sh".

To run all of the tests, use the command scripts/run.sh.  It has the following
usage:

        scripts/run.sh [diderotc] [diderotc-flags] [-- runtime-flags]

As it runs, it writes progress information to standard out.  It also produces
two files.  A reprt file that summarizes the results and a log file that contains
any output from running the compiler or program (e.g., error messages).

To run a single test, use the command scripts/run-one.sh, which has the
following usage:

        scripts/run-one.sh test [diderotc] [diderotc-flags]