rem: static unsigned int region_hash(void *_r, const void *key, unsigned int range)
add: region_hash(void *_r, const void *key, uint32 range)
context: static unsigned int region_hash(void *_r, const void *key, unsigned int range){	vm_region *r = _r;	const region_id *id = key;	if(r != NULL)		return (r->id % range);	else		return (*id % range);}