Dir.children is available since Feature #11302. FileUtils uses

Dir.each on an internal method encapsulated on a private class
`Entry_#entry`, having no '.' neither '..' entries would make
now superfluous a chained reject filtering.

This change can improve the performance of these FileUtils
methods when the provided path covers thousands of files or
directories:

- chmod_R
- chown_R
- remove_entry
- remove_entry_secure
- rm_r
- remove_dir
- copy_entry

Related: Feature #13896 https://bugs.ruby-lang.org/issues/13896

[Feature #14109][Fix GH-1754]

Co-Authored-By: esparta <[email protected]>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65610 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: hsbt

lib/fileutils.rb

@@ -1274,8 +1274,7 @@ def door?
     def entries
       opts = {}
       opts[:encoding] = ::Encoding::UTF_8 if fu_windows?
-      Dir.entries(path(), opts)\
-          .reject {|n| n == '.' or n == '..' }\
+      Dir.children(path, opts)\
           .map {|n| Entry_.new(prefix(), join(rel(), n.untaint)) }
     end