vm_object_hold_try
if (vm_object_hold_try(pmobj) == 0) {
if (vm_object_hold_try(pmobj) == 0) {
VMOBJDEBUG(vm_object_hold_try)(vm_object_t obj VMOBJDBARGS)
int VMOBJDEBUG(vm_object_hold_try)(vm_object_t object VMOBJDBARGS);
if (vm_object_hold_try(obj)) {