replay: introduce info hmp/qmp command

replay: introduce info hmp/qmp command

This patch introduces 'info replay' monitor command and
corresponding qmp request.
These commands request the current record/replay mode, replay log file
name, and the instruction count (number of recorded/replayed
instructions).  The instruction count can be used with the
replay_seek/replay_break commands added in the next two patches.

Signed-off-by: Pavel Dovgalyuk <[email protected]>
Acked-by: Dr. David Alan Gilbert <[email protected]>
Acked-by: Markus Armbruster <[email protected]>
Message-Id: <160174520026.12451.13112161947433306561.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <[email protected]>