Fix types with multiple args; refine closedness test

* GNUmakefile (OBFLAGS): Use `-tag`.

* btl/builtins.typer (expand_dmacro_): Remove redundant explicit args.
(sexp_dispatch_): Name the arguments.

* emacs/typer-mode.el (typer-smie-rules): Tweak rule for `=`.

* src/eval.ml (not_closed): Rename from closed_dbset_p.  Return a list.
(from_lctx): Add `meta_ctx` arg.  `clean` exps before passing to `fv`.

* src/lexp.ml (push_susp) <Inductive>: Don't reverse type's args.
<Case>: Don't skip unnamed fields.
(clean) <Let>: Fix up typo.
<Inductive>: Don't reverse type's args.
<Case>: Don't skip unnamed fields.

* src/lparse.ml (check_case.add_branch): Substitution was built in the
wrong order.
(lexp_expand_macro_): Check closeness of the macro definition.