chainntnfs: update bitcoind and btcd backends to match new spend ntfn API

chainntnfs/bitcoindnotify/bitcoind.go

@@ -577,7 +577,7 @@ type spendCancel struct {
 // across the 'Spend' channel. The heightHint should represent the earliest
 // height in the chain where the transaction could have been spent in.
 func (b *BitcoindNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
-	heightHint uint32) (*chainntnfs.SpendEvent, error) {
+	pkScript []byte, heightHint uint32) (*chainntnfs.SpendEvent, error) {
 
 	ntfn := &spendNotification{
 		targetOutpoint: outpoint,

chainntnfs/btcdnotify/btcd.go

@@ -695,7 +695,7 @@ type spendCancel struct {
 // across the 'Spend' channel. The heightHint should represent the earliest
 // height in the chain where the transaction could have been spent in.
 func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
-	heightHint uint32) (*chainntnfs.SpendEvent, error) {
+	pkScript []byte, heightHint uint32) (*chainntnfs.SpendEvent, error) {
 
 	ntfn := &spendNotification{
 		targetOutpoint: outpoint,
@@ -710,6 +710,7 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 	case b.notificationRegistry <- ntfn:
 	}
 
+	// TODO(roasbeef): update btcd rescan logic to also use both
 	if err := b.chainConn.NotifySpent([]*wire.OutPoint{outpoint}); err != nil {
 		return nil, err
 	}

chainntnfs/interface.go

@@ -53,7 +53,7 @@ type ChainNotifier interface {
 	// NOTE: Dispatching notifications to multiple clients subscribed to a
 	// spend of the same outpoint MUST be supported.
 	RegisterSpendNtfn(outpoint *wire.OutPoint, pkScript []byte,
-		heightHint uint32, mempool bool) (*SpendEvent, error)
+		heightHint uint32) (*SpendEvent, error)
 
 	// RegisterBlockEpochNtfn registers an intent to be notified of each
 	// new block connected to the tip of the main chain. The returned