vendor: update moby/buildkit

Update modules:

  go mod edit -require github.com/moby/buildkit@master
  go mod tidy -compat=1.17 && ./hack/update-vendor

Signed-off-by: Justin Chadwell <me@jedevc.com>

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

@@ -19,9 +19,29 @@ type WalkOpt struct {
 	// FollowPaths contains symlinks that are resolved into include patterns
 	// before performing the fs walk
 	FollowPaths []string
-	Map         FilterFunc
+	Map         MapFunc
 }
 
+type MapFunc func(string, *types.Stat) MapResult
+
+// The result of the walk function controls
+// both how WalkDir continues and whether the path is kept.
+type MapResult int
+
+const (
+	// Keep the current path and continue.
+	MapResultKeep MapResult = iota
+
+	// Exclude the current path and continue.
+	MapResultExclude
+
+	// Exclude the current path, and skip the rest of the dir.
+	// If path is a dir, skip the current directory.
+	// If path is a file, skip the rest of the parent directory.
+	// (This matches the semantics of fs.SkipDir.)
+	MapResultSkipDir
+)
+
 func Walk(ctx context.Context, p string, opt *WalkOpt, fn filepath.WalkFunc) error {
 	root, err := filepath.EvalSymlinks(p)
 	if err != nil {
@@ -258,7 +278,10 @@ func Walk(ctx context.Context, p string, opt *WalkOpt, fn filepath.WalkFunc) err
 			return ctx.Err()
 		default:
 			if opt != nil && opt.Map != nil {
-				if allowed := opt.Map(stat.Path, stat); !allowed {
+				result := opt.Map(stat.Path, stat)
+				if result == MapResultSkipDir {
+					return filepath.SkipDir
+				} else if result == MapResultExclude {
 					return nil
 				}
 			}
@@ -277,7 +300,8 @@ func Walk(ctx context.Context, p string, opt *WalkOpt, fn filepath.WalkFunc) err
 				default:
 				}
 				if opt != nil && opt.Map != nil {
-					if allowed := opt.Map(parentStat.Path, parentStat); !allowed {
+					result := opt.Map(parentStat.Path, parentStat)
+					if result == MapResultSkipDir || result == MapResultExclude {
 						continue
 					}
 				}