Tests in this directory cover the basics like tokens,
parsing, and basic errors in those phases.

Each file is run through "pip --print-ast". The output
is compared to the log.

The result is run again (to test that the "--print-ast"
option produces a valid program) and the results from
this second run are also compared to the log to ensure
that a fixed point is reached after two iterations.

Note that if the first run had an error (like a parse
error) then no second run is performed. The error itself
is compared against the log for a match.
