Issue #17206: test.regrtest and test.script_helper enable faulthandler module

in subprocesses.

Lib/test/regrtest.py

@@ -701,7 +701,8 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
         output = Queue()
         pending = MultiprocessTests(tests)
         opt_args = support.args_from_interpreter_flags()
-        base_cmd = [sys.executable] + opt_args + ['-m', 'test.regrtest']
+        base_cmd = [sys.executable] + opt_args
+        base_cmd += ['-X', 'faulthandler', '-m', 'test.regrtest']
         def work():
             # A worker thread.
             try:

Lib/test/script_helper.py

@@ -17,7 +17,7 @@ from test.support import make_legacy_pyc, strip_python_stderr
 
 # Executing the interpreter in a subprocess
 def _assert_python(expected_success, *args, **env_vars):
-    cmd_line = [sys.executable]
+    cmd_line = [sys.executable, '-X', 'faulthandler']
     if not env_vars:
         cmd_line.append('-E')
     # Need to preserve the original environment, for in-place testing of