Move read-char-from-minibuffer from simple.el to subr.el and document it.

* doc/lispref/minibuf.texi (Multiple Queries):
Document read-char-from-minibuffer (bug#10477, bug#38076).

* lisp/subr.el (read-char-history)
(read-char-from-minibuffer-insert-other, empty-history)
(read-char-from-minibuffer): Move from simple.el to subr.el.
1 job for master in 90 minutes and 1 second (queued for 3 seconds)
Status Job ID Name Coverage
failed #4178


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-d0b76032 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds