all: Adjust windows perms in fs package (#5200)

lib/osutil/osutil.go

@@ -10,7 +10,6 @@ package osutil
 import (
 	"errors"
 	"io"
-	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -136,24 +135,6 @@ func copyFileContents(filesystem fs.Filesystem, src, dst string) (err error) {
 	return
 }
 
-var execExts map[string]bool
-
-func init() {
-	// PATHEXT contains a list of executable file extensions, on Windows
-	pathext := filepath.SplitList(os.Getenv("PATHEXT"))
-	// We want the extensions in execExts to be lower case
-	execExts = make(map[string]bool, len(pathext))
-	for _, ext := range pathext {
-		execExts[strings.ToLower(ext)] = true
-	}
-}
-
-// IsWindowsExecutable returns true if the given path has an extension that is
-// in the list of executable extensions.
-func IsWindowsExecutable(path string) bool {
-	return execExts[strings.ToLower(filepath.Ext(path))]
-}
-
 func IsDeleted(ffs fs.Filesystem, name string) bool {
 	if _, err := ffs.Lstat(name); fs.IsNotExist(err) {
 		return true