Repeat most recently executed command.
If REPEAT-ARG is non-nil (interactively, with a prefix argument),
supply a prefix argument to that command. Otherwise, give the
command the same prefix argument it was given before, if any.
If this command is invoked by a multi-character key sequence, it
can then be repeated by repeating the final character of that
sequence. This behavior can be modified by the global variable
`repeat' ignores commands bound to input events. Hence the term
"most recently executed command" shall be read as "most
recently executed command not bound to an input event". (fn REPEAT-ARG)