Noticed while investigating the issue with DECgraphics characters in
msg_window:full/combination/reverse output for tty which got fixed
by the previous commit. There was a discrepancy in DUMPLOG because
the pager code bypasses pline() in order to use putmixed(). tty
puts strings from the latter into ^P recall history (although they'll
only render correctly if nothing after the first character needs
special handling), but nothing was putting that same info into
DUMPLOG. This fix is pretty clumsy but eliminates the discrepancy.
423cf77a37