[lit] cleanup unused imports (#143930)

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

lld/test/Unit/lit.cfg.py

@@ -3,7 +3,6 @@
 # Configuration file for the 'lit' test runner.
 
 import os
-import subprocess
 
 import lit.formats
 

lldb/test/API/lit.cfg.py

@@ -9,8 +9,6 @@ import shutil
 import subprocess
 import sys
 
-import lit.formats
-
 # name: The name of this test suite.
 config.name = "lldb-api"
 

lldb/test/Shell/lit.cfg.py

@@ -7,12 +7,9 @@ import re
 import shutil
 import site
 import subprocess
-import sys
 
-import lit.formats
+import lit.util
 from lit.llvm import llvm_config
-from lit.llvm.subst import FindTool
-from lit.llvm.subst import ToolSubst
 
 site.addsitedir(os.path.dirname(__file__))
 from helper import toolchain

lldb/test/lit.cfg.py

@@ -2,9 +2,6 @@
 
 import os
 
-import lit.formats
-from lit.llvm import llvm_config
-
 # This is the top level configuration. Most of these configuration options will
 # be overriden by individual lit configuration files in the test
 # subdirectories. Anything configured here will *not* be loaded when pointing

llvm/utils/lit/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

llvm/utils/lit/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 shlex
 import shutil
 import tempfile
 import threading
-import typing
 from typing import Optional, Tuple
 
-import io
-
 try:
     from StringIO import StringIO
 except ImportError:

llvm/utils/lit/lit/discovery.py

@@ -6,8 +6,8 @@ import copy
 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):

llvm/utils/lit/lit/worker.py

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