Issue #11651: Move options for running tests into a Python script.

This will be particularly useful to Windows users.

run_tests.py originally written by Brett Cannon.

Tools/scripts/run_tests.py

@@ -0,0 +1,45 @@
+"""Run Python's test suite in a fast, rigorous way.
+
+The defaults are meant to be thorough but to skip certain resources are not
+used (by default) which can consume a lot of time and resources (e.g.,
+largefile) or can be distracting (e.g., audio and gui). These defaults
+can be overridden by simply passing a -u option to this script.
+
+"""
+
+import os
+import sys
+import test.support
+
+
+def is_multiprocess_flag(arg):
+    return arg.startswith('-j') or arg.startswith('--multiprocess')
+
+
+def is_resource_use_flag(arg):
+    return arg.startswith('-u') or arg.startswith('--use')
+
+
+def main(regrtest_args):
+    args = [sys.executable,
+            '-W', 'default',      # Warnings set to 'default'
+            '-bb',                # Warnings about bytes/bytearray
+            '-E',                 # Ignore environment variables
+            ]
+    # Allow user-specified interpreter options to override our defaults.
+    args.extend(test.support.args_from_interpreter_flags())
+    args.extend(['-m', 'test',    # Run the test suite
+                 '-r',            # Randomize test order
+                 '-w',            # Re-run failed tests in verbose mode
+                 ])
+    if not any(is_multiprocess_flag(arg) for arg in regrtest_args):
+        args.extend(['-j', '0'])  # Use all CPU cores
+    if not any(is_resource_use_flag(arg) for arg in regrtest_args):
+        args.extend(['-u', 'all,-largefile,-audio,-gui'])
+    args.extend(regrtest_args)
+    print(' '.join(args))
+    os.execv(sys.executable, args)
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])