Merge 3.2: Issue #13703 plus some related test suite fixes.
diff --git a/Tools/scripts/run_tests.py b/Tools/scripts/run_tests.py
index f750e19..fb7ce5c 100755
--- a/Tools/scripts/run_tests.py
+++ b/Tools/scripts/run_tests.py
@@ -25,6 +25,7 @@
             '-W', 'default',      # Warnings set to 'default'
             '-bb',                # Warnings about bytes/bytearray
             '-E',                 # Ignore environment variables
+            '-R',                 # Randomize hashing
             ]
     # Allow user-specified interpreter options to override our defaults.
     args.extend(test.support.args_from_interpreter_flags())