stdlib/os: Update method of extending builtin os.

Author: pi-anl

python-stdlib/os/os/__init__.py

@@ -1,5 +1,11 @@
-# Replace built-in os module.
-from uos import *
+# Include built-in os module.
+import sys
+__path = sys.path
+try:
+    sys.path.clear()
+    from os import *
+finally:
+    sys.path.extend(__path)
 
 # Provide optional dependencies (which may be installed separately).
 try: