Factor out stripping of interpreter debug output in test.support.strip_python_stderr()
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index e6ba8cb..eb0f5d7 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -53,7 +53,7 @@
# In a debug build, stuff like "[6580 refs]" is printed to stderr at
# shutdown time. That frustrates tests trying to check stderr produced
# from a spawned Python process.
- actual = re.sub("\[\d+ refs\]\r?\n?$", "", stderr.decode()).encode()
+ actual = support.strip_python_stderr(stderr)
self.assertEqual(actual, expected, msg)