Update dependencies

vendor/gvisor.dev/gvisor/pkg/sync/sync.go

@@ -0,0 +1,9 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package sync provides synchronization primitives.
+//
+// +checkalignedignore
+package sync