gh-146547: Use lazy imports in ctypes, including for sysconfig, shutil, subprocess and warnings modules

Lib/ctypes/__init__.py

@@ -2,9 +2,10 @@
 
 import os as _os
 import sys as _sys
-import sysconfig as _sysconfig
 import types as _types
 
+lazy import sysconfig as _sysconfig
+
 from _ctypes import Union, Structure, Array
 from _ctypes import _Pointer
 from _ctypes import CFuncPtr as _CFuncPtr

Lib/ctypes/_layout.py

@@ -5,11 +5,12 @@
 """
 
 import sys
-import warnings
 
 from _ctypes import CField, buffer_info
 import ctypes
 
+lazy import warnings
+
 def round_down(n, multiple):
     assert n >= 0
     assert multiple > 0

Lib/ctypes/util.py

@@ -1,8 +1,9 @@
 import os
-import shutil
-import subprocess
 import sys
 
+lazy import shutil
+lazy import subprocess
+
 # find_library(name) returns the pathname of a library, or None.
 if os.name == "nt":