handle ACKs separately in the sent packet handler packet struct

internal/ackhandler/ack_eliciting.go

@@ -2,17 +2,6 @@ package ackhandler
 
 import "github.com/lucas-clemente/quic-go/internal/wire"
 
-// Returns a new slice with all non-ack-eliciting frames deleted.
-func stripNonAckElicitingFrames(fs []wire.Frame) []wire.Frame {
-	res := make([]wire.Frame, 0, len(fs))
-	for _, f := range fs {
-		if IsFrameAckEliciting(f) {
-			res = append(res, f)
-		}
-	}
-	return res
-}
-
 // IsFrameAckEliciting returns true if the frame is ack-eliciting.
 func IsFrameAckEliciting(f wire.Frame) bool {
 	switch f.(type) {