vendor: update buildkit

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/moby/spdystream/handlers.go

@@ -0,0 +1,52 @@
+/*
+   Copyright 2014-2021 Docker Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package spdystream
+
+import (
+	"io"
+	"net/http"
+)
+
+// MirrorStreamHandler mirrors all streams.
+func MirrorStreamHandler(stream *Stream) {
+	replyErr := stream.SendReply(http.Header{}, false)
+	if replyErr != nil {
+		return
+	}
+
+	go func() {
+		io.Copy(stream, stream)
+		stream.Close()
+	}()
+	go func() {
+		for {
+			header, receiveErr := stream.ReceiveHeader()
+			if receiveErr != nil {
+				return
+			}
+			sendErr := stream.SendHeader(header, false)
+			if sendErr != nil {
+				return
+			}
+		}
+	}()
+}
+
+// NoopStreamHandler does nothing when stream connects.
+func NoOpStreamHandler(stream *Stream) {
+	stream.SendReply(http.Header{}, false)
+}