Add missing List imports.

stdlib/2and3/distutils/spawn.pyi

@@ -1,6 +1,6 @@
 # Stubs for distutils.spawn
 
-from typing import Optional
+from typing import List, Optional
 
 def spawn(cmd: List[str], search_path: bool = ...,
           verbose: bool = ..., dry_run: bool = ...) -> None: ...

stdlib/2and3/distutils/text_file.pyi

@@ -1,6 +1,6 @@
 # Stubs for distutils.text_file
 
-from typing import IO, Optional, Tuple, Union
+from typing import IO, List, Optional, Tuple, Union
 
 class TextFile:
     def __init__(self, filename: Optional[str] = ...,

stdlib/2and3/distutils/util.pyi

@@ -1,6 +1,6 @@
 # Stubs for distutils.util
 
-from typing import Any, Callable, Mapping, Optional, Tuple
+from typing import Any, Callable, List, Mapping, Optional, Tuple
 
 
 def get_platform() -> str: ...