Run (make vendor) for the first time.

This primarily adds vendor/github.com/containers/image/docs/ ,
but also updates other dependencies that are not pinned to a specific
commit.

vendor/golang.org/x/sys/unix/syscall_unix.go

@@ -9,6 +9,7 @@ package unix
 import (
 	"bytes"
 	"runtime"
+	"sort"
 	"sync"
 	"syscall"
 	"unsafe"
@@ -51,6 +52,28 @@ func errnoErr(e syscall.Errno) error {
 	return e
 }
 
+// ErrnoName returns the error name for error number e.
+func ErrnoName(e syscall.Errno) string {
+	i := sort.Search(len(errorList), func(i int) bool {
+		return errorList[i].num >= e
+	})
+	if i < len(errorList) && errorList[i].num == e {
+		return errorList[i].name
+	}
+	return ""
+}
+
+// SignalName returns the signal name for signal number s.
+func SignalName(s syscall.Signal) string {
+	i := sort.Search(len(signalList), func(i int) bool {
+		return signalList[i].num >= s
+	})
+	if i < len(signalList) && signalList[i].num == s {
+		return signalList[i].name
+	}
+	return ""
+}
+
 // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
 func clen(n []byte) int {
 	i := bytes.IndexByte(n, 0)