Issue #15539: Fix a backup file creation in pindent.py on Windows.

diff --cc Tools/scripts/pindent.py
index 25006ae35d6a06c90d127bf4f9cf915643b8ee36,2872dc047e0f52b5941764205d1138cbc796622f..33334204a4d455d26ae5ca36582003ab66e64c5a
--- 1/Tools/scripts/pindent.py
--- 2/Tools/scripts/pindent.py
+++ b/Tools/scripts/pindent.py
@@@ -370,6 -370,23 +370,23 @@@ def reformat_string(source, stepsize = 
      return output.getvalue()
  # end def reformat_string
  
 -        except os.error:
+ def make_backup(filename):
+     import os, os.path
+     backup = filename + '~'
+     if os.path.lexists(backup):
+         try:
+             os.remove(backup)
 -    except os.error:
++        except OSError:
+             print("Can't remove backup %r" % (backup,), file=sys.stderr)
+         # end try
+     # end if
+     try:
+         os.rename(filename, backup)
++    except OSError:
+         print("Can't rename %r to %r" % (filename, backup), file=sys.stderr)
+     # end try
+ # end def make_backup
+ 
  def complete_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
      with open(filename, 'r') as f:
          source = f.read()