lisp/progmodes/verilog-mode.el: Prepare for lexical-binding.

lisp/progmodes/verilog-mode.el: Prepare for lexical-binding.

* lisp/progmodes/verilog-mode.el: Activate lexical-binding.
Insert newlines to avoid some situations where arguments were easy
to misunderstand.
(verilog-set-compile-command): Strength-reduce `eval` to `symbol-value`.
(verilog-error-regexp-add-emacs): Replace `mapcar` => `mapc` since
the result is not used.
(verilog-surelint-off): Remove always-nil var `dir`.
(verilog-do-indent): Minor simplification of the code.
(verilog-pred): Delete var.  It was always nil.
(verilog-flag): Delete var; pass the corresponding data via
explicit arguments instead.
(verilog-keyword-completion): Use `dolist`.
(verilog-completion-response): Rename to `verilog--complete-with-action`.
Change calling convention to match that of `complete-with-action`.
Use `complete-with-action` instead when available.
Adjust all callers.
(verilog-completion, verilog-comp-defun): Change arg names so they
don't collide with dynamically scoped vars, and let-bind `verilog-str`
explicitly instead.  Use `with-current-buffer`.
(verilog-batch-execute-func): Use `with-current-buffer`.
(verilog-complete-word): Don't convert the completion list into
a completion alist, since lists work just as well.
(verilog-showscopes): Use `with-current-buffer`.
(verilog-symbol-detick, verilog-symbol-detick-text)
(verilog-signals-matching-enum): Strength-reduce `eval` to `symbol-value`.
(verilog--insert-indent): Rename from `verilog--insert-indent`.
Add `indent-pt` argument.
(verilog-insert-indent): New macro wrapper to provide the old
calling convention.
(verilog-auto-assign-modport, verilog-auto-inout-modport):
Remove always-nil var `direction-re`.
(verilog--auto-inst-first): Rename from `verilog-auto-inst-first`.
Add `indent-pt` argument.
(verilog-auto-inst-port): Adjust call accordingly.