bug#21867: 25.0.50; lossage's log doesn't treat characters read by read-char as separate commands

[Juri Linkov <juri@linkov.net>]

>>> in recent_keys.  `view-lossage' could use this to output this as
>>>
>>> C-x C-e a    ;; eval-last-sexp
>>
>> I think that would be no better than what we have now.  To be better,
>> we'd want something like:
>>
>>     C-x C-e [eval-last-sexp] a
>>
>> which clearly separates between the events received before the command
>> from those received during the command.
>
> Yes, that's better and should be even easier to achieve.  Although we
> may have to give up the columnar buffer to do that.

The intention of the columnar format was to maintain compatibility
with the Keyboard Macro Editor (edit-last-kbd-macro).  After typing
the same keys while recording the keyboard macro produces the
buffer where `a' is presented as `self-insert-command':

  ;; Keyboard Macro Editor.  Press C-c C-c to finish; press C-x k RET to cancel.
  ;; Original keys: C-x C-e a

  Command: last-kbd-macro
  Key: none

  Macro:

  C-x C-e                 ;; eval-last-sexp
  a                       ;; self-insert-command