This allows a 30% speedup on the construction of large LR(1) automata
and in conflict explanation.

although it is not clear whether this is necessary.

Fix DWordBitSet.remove and QWordBitSet.remove in the same way, although it is not clear whether this is necessary.

always preserves physical equality when the element is already in the set.
This property was exploited by the conflict explanation code. The failure
of this property (since 2020/01/30) would cause all reduce/reduce conflicts
to be mistakenly declared unexplainable.

This grammar currently has an unexplainable conflict which in fact
should be explainable. Investigation shows that this is due to an
incorrect assumption about the function [TerminalSet.add]. This will
be fixed in the next commit.

instead of .cmo and .cmx. This should have been done earlier (when we
switched to automated installation via opam).

Remove --no-print-directory, because it prevents emacs from jumping to the file that contains the error.

Use [pvarlocated] when creating the mock file, so that warnings or errors about unused semantic values are reported in the .mly file.

Change [src/Makefile] so that [make] under emacs produces errors that emacs knows how to locate (yay).

A pseudo-token (declared e.g. by %left) could appear in a position where a
normal token was expected (e.g., as an actual parameter of a parameterized
symbol) and that was not detected, giving rise (later on) to an assertion
failure.

Infer: change the content of the .mock.ml file so that all occurrences of the type of a nonterminal symbol are shared. Also, use the type inferred by OCaml instead of the type declared by the user, as they do not necessarily coincide. This closes issue #37. Adjust the demo test/dynamic/misc/variants, where the OCaml type-checker now correctly requires one more branch in the [match] construct.

New test test/dynamic/misc/variants, which in the current version of Menhir causes a segmentation fault. This illustrates issue #37.

Change [Infer.ntvar] to return a type, not a string. Do not export [CodePieces.ntvar], which is unused.