bpo-28624: Add a test that checks that cwd parameter of Popen() accepts PathLike objects (#157) (#323)

(cherry picked from commit d5c11f7ace48701bb950c6345deee88c35c66e26)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index e63f9f2..3c871dd 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -347,6 +347,16 @@
         temp_dir = self._normalize_cwd(temp_dir)
         self._assert_cwd(temp_dir, sys.executable, cwd=temp_dir)
 
+    def test_cwd_with_pathlike(self):
+        temp_dir = tempfile.gettempdir()
+        temp_dir = self._normalize_cwd(temp_dir)
+
+        class _PathLikeObj:
+            def __fspath__(self):
+                return temp_dir
+
+        self._assert_cwd(temp_dir, sys.executable, cwd=_PathLikeObj())
+
     @unittest.skipIf(mswindows, "pending resolution of issue #15533")
     def test_cwd_with_relative_arg(self):
         # Check that Popen looks for args[0] relative to cwd if args[0]