vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/tonistiigi/fsutil/diskwriter_windows.go

@@ -0,0 +1,18 @@
+// +build windows
+
+package fsutil
+
+import (
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/fsutil/types"
+)
+
+func rewriteMetadata(p string, stat *types.Stat) error {
+	return chtimes(p, stat.ModTime)
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(path string, stat *types.Stat) error {
+	return errors.New("Not implemented on windows")
+}