vendor: add buildkit

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

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

@@ -0,0 +1,61 @@
+package fsutil
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/fsutil/types"
+)
+
+// constructs a Stat object. path is where the path can be found right
+// now, relpath is the desired path to be recorded in the stat (so
+// relative to whatever base dir is relevant). fi is the os.Stat
+// info. inodemap is used to calculate hardlinks over a series of
+// mkstat calls and maps inode to the canonical (aka "first") path for
+// a set of hardlinks to that inode.
+func mkstat(path, relpath string, fi os.FileInfo, inodemap map[uint64]string) (*types.Stat, error) {
+	relpath = filepath.ToSlash(relpath)
+
+	stat := &types.Stat{
+		Path:    relpath,
+		Mode:    uint32(fi.Mode()),
+		ModTime: fi.ModTime().UnixNano(),
+	}
+
+	setUnixOpt(fi, stat, relpath, inodemap)
+
+	if !fi.IsDir() {
+		stat.Size_ = fi.Size()
+		if fi.Mode()&os.ModeSymlink != 0 {
+			link, err := os.Readlink(path)
+			if err != nil {
+				return nil, errors.Wrapf(err, "failed to readlink %s", path)
+			}
+			stat.Linkname = link
+		}
+	}
+	if err := loadXattr(path, stat); err != nil {
+		return nil, errors.Wrapf(err, "failed to xattr %s", relpath)
+	}
+
+	if runtime.GOOS == "windows" {
+		permPart := stat.Mode & uint32(os.ModePerm)
+		noPermPart := stat.Mode &^ uint32(os.ModePerm)
+		// Add the x bit: make everything +x from windows
+		permPart |= 0111
+		permPart &= 0755
+		stat.Mode = noPermPart | permPart
+	}
+
+	return stat, nil
+}
+
+func Stat(path string) (*types.Stat, error) {
+	fi, err := os.Lstat(path)
+	if err != nil {
+		return nil, errors.Wrap(err, "os stat")
+	}
+	return mkstat(path, filepath.Base(path), fi, nil)
+}