[lit] cleanup unused imports (#143930)

Remove imports that are not used in some lit test files.

Author: charles-zablit

lit/LitConfig.py

@@ -1,14 +1,12 @@
 from __future__ import absolute_import
+
 import inspect
 import os
-import platform
 import sys
 
-import lit.Test
-import lit.formats
-import lit.TestingConfig
 import lit.util
 
+
 # LitConfig must be a new style class for properties to work
 class LitConfig(object):
     """LitConfig - Configuration data for a 'lit' test runner instance, shared

lit/TestRunner.py

@@ -1,7 +1,4 @@
 from __future__ import absolute_import
-import errno
-import io
-import itertools
 import getopt
 import os, signal, subprocess, sys
 import re
@@ -12,11 +9,8 @@
 import shutil
 import tempfile
 import threading
-import typing
 from typing import Optional, Tuple
 
-import io
-
 try:
     from StringIO import StringIO
 except ImportError:

lit/discovery.py

@@ -6,8 +6,8 @@
 import os
 import sys
 
+from lit import Test, util
 from lit.TestingConfig import TestingConfig
-from lit import LitConfig, Test, util
 
 
 def chooseConfigFileFromDir(dir, config_names):

lit/worker.py

@@ -12,8 +12,6 @@
 import traceback
 
 import lit.Test
-import lit.util
-
 
 _lit_config = None
 _parallelism_semaphores = None