There was a bug in disappeared-use tracking--a missing
syntax-local-introduce. This change uses `with-disappeared-uses` and
`syntax-local-value/record`, instead of the (broken) manual tracking
that was present before.
I believe that non-BR parser-tools also has this bug, but I haven't
ported the fix yet.
This commit adds 3 tests. All 3 should pass, but right now 2 of them
fail because char-complement is considering (repetition n n e) to be
a charset for *any* n, so long as e is a charset.
Jesse A. Tov
Matthew Butterick