bug#20445: excessive redisplay / echo area resizing during byte-compilation

[martin rudalics]

> But I actually am not sure why (message nil) is used as a knob to
> control whether echo-area messages are or aren't displayed.  Can you
> explain?

Maybe (message nil) is supposed to suppress showing the previous message
in the echo area (but still keep its log somewhere).  If so, the concept
fails miserably here.

martin