CPU watchpoints can be use by non-TCG accelerators.

KVM uses them:

  $ git grep CPUWatchpoint|fgrep kvm
  target/arm/kvm64.c:1558:        CPUWatchpoint *wp = find_hw_watchpoint(cs, debug_exit->far);
  target/i386/kvm/kvm.c:5216:static CPUWatchpoint hw_watchpoint;
  target/ppc/kvm.c:443:static CPUWatchpoint hw_watchpoint;
  target/s390x/kvm/kvm.c:139:static CPUWatchpoint hw_watchpoint;

See for example commit e4482ab7 ("target-arm: kvm - add support
for HW assisted debug"):

     This adds basic support for HW assisted debug. The ioctl interface
     to KVM allows us to pass an implementation defined number of break
     and watch point registers. [...]

This partially reverts commit 2609ec28.

Fixes: 2609ec28 ("softmmu: Extract watchpoint API from physmem.c")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230328173117.15226-4-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>