Add vendoring to containerd master

Initial vendor list validated with empty $GOPATH
and only master checked out; followed by `make`
and verified that all binaries build properly.
Updates require github.com/LK4D4/vndr tool.

Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>

vendor/github.com/tonistiigi/fifo/handle_nolinux.go

@@ -0,0 +1,49 @@
+// +build !linux
+
+package fifo
+
+import (
+	"syscall"
+
+	"github.com/pkg/errors"
+)
+
+type handle struct {
+	fn  string
+	dev uint64
+	ino uint64
+}
+
+func getHandle(fn string) (*handle, error) {
+	var stat syscall.Stat_t
+	if err := syscall.Stat(fn, &stat); err != nil {
+		return nil, errors.Wrapf(err, "failed to stat %v", fn)
+	}
+
+	h := &handle{
+		fn:  fn,
+		dev: uint64(stat.Dev),
+		ino: stat.Ino,
+	}
+
+	return h, nil
+}
+
+func (h *handle) Path() (string, error) {
+	var stat syscall.Stat_t
+	if err := syscall.Stat(h.fn, &stat); err != nil {
+		return "", errors.Wrapf(err, "path %v could not be statted", h.fn)
+	}
+	if uint64(stat.Dev) != h.dev || stat.Ino != h.ino {
+		return "", errors.Errorf("failed to verify handle %v/%v %v/%v for %v", stat.Dev, h.dev, stat.Ino, h.ino, h.fn)
+	}
+	return h.fn, nil
+}
+
+func (h *handle) Name() string {
+	return h.fn
+}
+
+func (h *handle) Close() error {
+	return nil
+}