Out of the four listed reasons, two are obsolete now, since stepping
does not modify the code table any more. The first reason also cannot
happen any more, since removing a breakpoint will also patch the stack
of the isolate, and even if not, removing a breakpoint which is not set
will have no effect (not even a stack rewriting). The same applies for
the last listed reason.

So overall, this code is not needed any more, since it has no effect.

R=thibaudm@chromium.org

Bug: v8:10611
Change-Id: I773ac2515b66e8bf66cb035c315db552024485c3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2316299Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69041}