use shutil.rmtree in preference to pathlib unlink

The missing_ok argument was only added to pathlib.Path.unlink in Python 3.8.
This made the cleanup function fail (sometimes silently) on versions of Python
prior to 3.8.

diff --git a/rtest/rtest.py b/rtest/rtest.py
index f11ee78d207345d3e7fd8656f97807f1b39dfb6c..9bb2e5b57310708e032d5eea97dacd929edc484a 100755 (executable)
--- a/rtest/rtest.py
+++ b/rtest/rtest.py
@@ -10,6 +10,7 @@
 import os
 import shutil
 import tempfile
+import shutil
 import subprocess
 import sys
 import platform
@@ -300,9 +301,9 @@ def doTest(TEST):
   TESTTYPES = {}
 
 def cleanup():
-  pathlib.Path(TMPFILE1).unlink(missing_ok=True)
-  pathlib.Path(TMPFILE2).unlink(missing_ok=True)
-  pathlib.Path(TMPINFILE).unlink(missing_ok=True)
+  shutil.rmtree(TMPFILE1, ignore_errors=True)
+  shutil.rmtree(TMPFILE2, ignore_errors=True)
+  shutil.rmtree(TMPINFILE, ignore_errors=True)
 atexit.register(cleanup)
 
 # Set REFDIR