quic: add LocalAddr and RemoteAddr to quic.Conn

These are missing for quic.Conn.

Fixes golang/go#70138

Change-Id: Ia443ffe0e73e143be5c29233a1ceb7cb16951acd
GitHub-Last-Rev: a326378
GitHub-Pull-Request: #225
Reviewed-on: https://go-review.googlesource.com/c/net/+/623157
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

quic/conn.go

@@ -176,6 +176,16 @@ func (c *Conn) String() string {
 	return fmt.Sprintf("quic.Conn(%v,->%v)", c.side, c.peerAddr)
 }
 
+// LocalAddr returns the local network address, if known.
+func (c *Conn) LocalAddr() netip.AddrPort {
+	return c.localAddr
+}
+
+// RemoteAddr returns the remote network address, if known.
+func (c *Conn) RemoteAddr() netip.AddrPort {
+	return c.peerAddr
+}
+
 // confirmHandshake is called when the handshake is confirmed.
 // https://www.rfc-editor.org/rfc/rfc9001#section-4.1.2
 func (c *Conn) confirmHandshake(now time.Time) {