all: convert more code to use net/netip directly

perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

net/dns/resolver/tsdns_server_test.go

@@ -7,11 +7,11 @@ package resolver
 import (
 	"fmt"
 	"net"
+	"net/netip"
 	"strings"
 	"testing"
 
 	"github.com/miekg/dns"
-	"tailscale.com/net/netaddr"
 )
 
 // This file exists to isolate the test infrastructure
@@ -22,7 +22,7 @@ import (
 // to queries of type A it receives with an A record containing ipv4,
 // to queries of type AAAA with an AAAA record containing ipv6,
 // to queries of type NS with an NS record containing name.
-func resolveToIP(ipv4, ipv6 netaddr.IP, ns string) dns.HandlerFunc {
+func resolveToIP(ipv4, ipv6 netip.Addr, ns string) dns.HandlerFunc {
 	return func(w dns.ResponseWriter, req *dns.Msg) {
 		m := new(dns.Msg)
 		m.SetReply(req)
@@ -73,7 +73,7 @@ func resolveToIP(ipv4, ipv6 netaddr.IP, ns string) dns.HandlerFunc {
 // to queries of type A it receives with an A record containing ipv4,
 // to queries of type AAAA with an AAAA record containing ipv6,
 // to queries of type NS with an NS record containing name.
-func resolveToIPLowercase(ipv4, ipv6 netaddr.IP, ns string) dns.HandlerFunc {
+func resolveToIPLowercase(ipv4, ipv6 netip.Addr, ns string) dns.HandlerFunc {
 	return func(w dns.ResponseWriter, req *dns.Msg) {
 		m := new(dns.Msg)
 		m.SetReply(req)
@@ -220,7 +220,7 @@ func weirdoGoCNAMEHandler(target string) dns.HandlerFunc {
 // dnsHandler returns a handler that replies with the answers/options
 // provided.
 //
-// Types supported: netaddr.IP.
+// Types supported: netip.Addr.
 func dnsHandler(answers ...any) dns.HandlerFunc {
 	return func(w dns.ResponseWriter, req *dns.Msg) {
 		m := new(dns.Msg)
@@ -235,7 +235,7 @@ func dnsHandler(answers ...any) dns.HandlerFunc {
 			switch a := a.(type) {
 			default:
 				panic(fmt.Sprintf("unsupported dnsHandler arg %T", a))
-			case netaddr.IP:
+			case netip.Addr:
 				ip := a
 				if ip.Is4() {
 					m.Answer = append(m.Answer, &dns.A{