Fixed fs package tests on Windows

src/fs/Walk_windows.go

@@ -2,23 +2,27 @@
 
 package fs
 
-import (
-	"io/fs"
-	"path/filepath"
-	"strings"
-)
+import "os"
 
 // Walk calls your callback function for every file name inside the directory.
 // It doesn't distinguish between files and directories.
 func Walk(directory string, callBack func(string)) error {
-	return filepath.WalkDir(directory, func(path string, d fs.DirEntry, err error) error {
-		fileName := d.Name()
+	f, err := os.Open(directory)
 
-		if strings.HasPrefix(fileName, ".") {
-			return filepath.SkipDir
-		}
+	if err != nil {
+		return err
+	}
 
-		callBack(fileName)
-		return nil
-	})
+	files, err := f.Readdirnames(0)
+	f.Close()
+
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		callBack(file)
+	}
+
+	return nil
 }