* lisp/info-xref.el (info-xref-check, info-xref-check-all): Move
commentary details into docstrings for better visibility.
Use compilation-mode for the results buffer.
(info-xref-output, info-xref-output-error, info-xref-with-output)
(info-xref-filename, info-xref-in-progress):
New internals for this.
(info-xref-check-list, info-xref-check-buffer)
(info-xref-check-all-custom): Use those.
(info-xref-output-buffer): Rename from info-xref-results-buffer.
(info-xref-output-heading): Rename from info-xref-filename-heading.
(info-xref-good, info-xref-bad, info-xref-xfile-alist)
(info-xref-filename-heading): Move to output managing section.
(info-xref-docstrings): New command checking "Info node `(foo)Bar'"
(info-xref-lock-file-p, info-xref-with-file): New helpers for it.
(info-xref-subfile-p): Move to generic section with those two.
(info-xref-check-node): New function split from
info-xref-check-buffer, shared by info-xref-docstrings.
(info-xref-goto-node-p): Move to a checking section with that func.
(info-xref-unavail): New counter.
(info-xref-check-node): Use it.
(info-xref-with-output): Show count of unavailables at end of output.
(info-xref-all-info-files): Exclude ".*" dotfiles. Ignore broken
symlinks. Exclude .texi files. Exclude Emacs backup files.
(info-xref-check-all-custom): Fix quietening viper-mode and
gnus-registry-install -- use setq not let so as not to unbind after load.
Fixes: debbugs:7611
Remove spurious node duplicate suppression, doesn't work, not wanted.
(info-xref-output): Take format style args, add "sit-for 0" to let
user see the results as they progress.
(info-xref-check-all-custom): New function.
(info-xref-all-info-files): Cons a bit less.
(info-xref-check-buffer): Use push and replace-regexp-in-string.
(info-xref-output): Call insert only once.
(info-xref-whitespace): Remove.
