files -- it was apparently dead, since all .expected files are here.

Currently equal to the performance of the table back-end.

by reading the positions from the lexbuf just in time. No speed
difference, but this should imply less frequent minor collections.

the environment record instead of updating it. This makes
the code back-end TWICE FASTER.

function is no longer required. This does not change the generated
code, but simplifies things slightly and reduces the generation time
(less work for the inliner).

to a Boolean field [env.error]. This yields slightly simpler
code and a small speed increase (maybe 5%).

in the special case where the language is empty or {epsilon} is now fixed.

or the singleton language {epsilon}.

rather than the Menhir in the PATH. This helps build the demos
while working.

No more deprecation warnings.

Modified [PreFront.read_whole_file] to use [IO.exhaust].