Update stdlib modules list

Also update `generate_stdlib_module_names.py` to collect `compression`,
a namespace package.

Author: emmatyping

Python/stdlib_module_names.h

@@ -70,8 +70,16 @@ def list_packages(names):
         package_path = os.path.join(STDLIB_PATH, name)
         if not os.path.isdir(package_path):
             continue
-        if any(package_file.endswith(".py")
-               for package_file in os.listdir(package_path)):
+        # Walk the package directory to check if the package is a namespace
+        has_py_files = False
+        for root, _dirs, files in os.walk(package_path):
+            for file in files:
+                if file.endswith(".py"):
+                    has_py_files = True
+                    break
+            if has_py_files:
+                break
+        if has_py_files:
             names.add(name)