gh-97669: Create Tools/patchcheck/ directory (#98186)

Move patchcheck.py, reindent.py and untabify.py scripts to a new
Tools/patchcheck/ directory.

Tools/patchcheck/untabify.py

@@ -0,0 +1,55 @@
+#! /usr/bin/env python3
+
+"Replace tabs with spaces in argument files.  Print names of changed files."
+
+import os
+import sys
+import getopt
+import tokenize
+
+def main():
+    tabsize = 8
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "t:")
+        if not args:
+            raise getopt.error("At least one file argument required")
+    except getopt.error as msg:
+        print(msg)
+        print("usage:", sys.argv[0], "[-t tabwidth] file ...")
+        return
+    for optname, optvalue in opts:
+        if optname == '-t':
+            tabsize = int(optvalue)
+
+    for filename in args:
+        process(filename, tabsize)
+
+
+def process(filename, tabsize, verbose=True):
+    try:
+        with tokenize.open(filename) as f:
+            text = f.read()
+            encoding = f.encoding
+    except IOError as msg:
+        print("%r: I/O error: %s" % (filename, msg))
+        return
+    newtext = text.expandtabs(tabsize)
+    if newtext == text:
+        return
+    backup = filename + "~"
+    try:
+        os.unlink(backup)
+    except OSError:
+        pass
+    try:
+        os.rename(filename, backup)
+    except OSError:
+        pass
+    with open(filename, "w", encoding=encoding) as f:
+        f.write(newtext)
+    if verbose:
+        print(filename)
+
+
+if __name__ == '__main__':
+    main()