Bookmark locations can refer to VC directory buffers (bug#39722)

* etc/NEWS: Document feature.
* lisp/vc/vc-dir.el (vc-dir-mode): Set local bookmark-make-record-function.
(bookmark-make-record-default, bookmark-prop-get, bookmark-default-handler)
(bookmark-get-bookmark-record): Declarations.
(vc-dir-bookmark-make-record): Make record used to bookmark a `vc-dir' buffer.
(vc-dir-bookmark-jump): Provides bookmark-jump behavior for a `vc-dir' buffer.
1 job for master in 90 minutes and 2 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #6047


Name Stage Failure
test-all Test The script exceeded the maximum execution time set for the job
  GEN      lisp/eshell/eshell-tests.log
ELC lisp/faces-tests.elc
GEN lisp/faces-tests.log
ELC lisp/ffap-tests.elc
GEN lisp/ffap-tests.log
ELC lisp/filenotify-tests.elc
GEN lisp/filenotify-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-f100a208 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds