Provide facility to ignore all marked files in vc

* lisp/vc/vc-dir.el: (vc-dir-ignore) With prefix argument, ignore all
marked files (bug#37240).
1 job for master in 90 minutes and 2 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #3290


Name Stage Failure
test-all Test The script exceeded the maximum execution time set for the job
  GEN      src/regex-emacs-tests.log
ELC src/syntax-tests.elc
GEN src/syntax-tests.log
ELC src/textprop-tests.elc
GEN src/textprop-tests.log
ELC src/thread-tests.elc
GEN src/thread-tests.log
Pulling docker image gitlab/gitlab-runner-helper:x86_64-d0b76032 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds