#4 display wrong after jump to actual checkpoint

[Soam S. Vasani]

If you try to jump to a place where an actual checkpoint
has been taken, then GDB does not know where we are,
because we have never run.

stop_pc etc. have wrong values, so the insight display
shows the wrong line of code highlighted.

Reproducing the bug:
Trace the attached testcase
Start the replayer
jump_forward 7
(the display does not update)
fs
(the display now updates to line 8).

[Soam S. Vasani]