all: use various net/netip parse funcs directly

Mechanical change with perl+goimports.

Changed {Must,}Parse{IP,IPPrefix,IPPort} to their netip variants, then
goimports -d .

Finally, removed the net/netaddr wrappers, to prevent future use.

Updates #5162

Change-Id: I59c0e38b5fbca5a935d701645789cddf3d7863ad
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

derp/derp_client.go

@@ -11,6 +11,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net/netip"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -609,5 +610,5 @@ func (c *Client) LocalAddr() (netaddr.IPPort, error) {
 	if a == nil {
 		return netaddr.IPPort{}, errors.New("nil addr")
 	}
-	return netaddr.ParseIPPort(a.String())
+	return netip.ParseAddrPort(a.String())
 }

derp/derp_server.go

@@ -25,6 +25,7 @@ import (
 	"math/rand"
 	"net"
 	"net/http"
+	"net/netip"
 	"os/exec"
 	"runtime"
 	"strconv"
@@ -663,7 +664,7 @@ func (s *Server) accept(ctx context.Context, nc Conn, brw *bufio.ReadWriter, rem
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	remoteIPPort, _ := netaddr.ParseIPPort(remoteAddr)
+	remoteIPPort, _ := netip.ParseAddrPort(remoteAddr)
 
 	c := &sclient{
 		connNum:        connNum,
@@ -1768,7 +1769,7 @@ func parseSSOutput(raw string) map[netaddr.IPPort]BytesSentRecv {
 		if len(ipInfo) < 5 {
 			continue
 		}
-		src, err := netaddr.ParseIPPort(ipInfo[4])
+		src, err := netip.ParseAddrPort(ipInfo[4])
 		if err != nil {
 			continue
 		}

derp/derphttp/derphttp_client.go

@@ -22,6 +22,7 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
+	"net/netip"
 	"net/url"
 	"runtime"
 	"strings"
@@ -583,7 +584,7 @@ func shouldDialProto(s string, pred func(netaddr.IP) bool) bool {
 	if s == "" {
 		return true
 	}
-	ip, _ := netaddr.ParseIP(s)
+	ip, _ := netip.ParseAddr(s)
 	return pred(ip)
 }