[mi] organize possible exec async mi oc command reasons

[Eli Zaretskii]

> Date: Sat, 26 Mar 2005 12:36:32 +0200
> From: "Eli Zaretskii" <eliz@gnu.org>
> 
> Btw, do we always have @var{reason} after "stopped"?  If not, then
> it's optional and should be inside [...].

In addition, it looks to me like "stopped" states the reason like so:

  *stopped,reason="REASON"

If this is true, then the first @table in the section we are talking
about should say

  @table @code
  @item
  *stopped,reason="@var{reason}"
  @end table