This will be needed as soon as config-poison.h moves from configure to
a meson custom_target (which is built at "ninja" time).
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We can use config-host.mak to decide whether the tool has to be built,
apart from that the conversion is straightforward.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>