[libcxx] Replace find_executable with shutil.which

[DavidSpickett]

Summary

distutils is deprecated and shutil.which is the suggested
replacement for this function.

https://peps.python.org/pep-0632/#migration-advice
https://docs.python.org/3/library/shutil.html#shutil.which

which was added in 3.3 (https://docs.python.org/3/library/shutil.html#shutil.which)
and LLVM requires at least 3.6 (https://llvm.org/docs/GettingStarted.html#software).

[philnik]

Thanks for cleaning this up! LGTM assuming the CI is happy.

[DavidSpickett]

AIX is offline and sanitizer failures are pre-existing so I will land this.

libcxx/utils/libcxx/sym_check/extract.py

 # -*- Python -*- vim: set syntax=python tabstop=4 expandtab cc=80:
 #===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #
 #===----------------------------------------------------------------------===##
 """
 extract - A set of function that extract symbol lists from shared libraries.
 """
-import distutils.spawn
 import os.path
 from os import environ
 import re
+import shutil
 import subprocess
 import sys
 
 from libcxx.sym_check import util
 
 extract_ignore_names = ['_init', '_fini']
 
 class NMExtractor(object):
     """
     NMExtractor - Extract symbol lists from libraries using nm.
     """
 
     @staticmethod
     def find_tool():
         """
         Search for the nm executable and return the path.
         """
-        return distutils.spawn.find_executable('nm')
+        return shutil.which('nm')
 
     def __init__(self, static_lib):
         """
         Initialize the nm executable and flags that will be used to extract
         symbols from shared libraries.
         """
         self.nm_exe = self.find_tool()
         if self.nm_exe is None:
class ReadElfExtractor(object):
     ReadElfExtractor - Extract symbol lists from libraries using readelf.
     """
 
     @staticmethod
     def find_tool():
         """
         Search for the readelf executable and return the path.
         """
-        return distutils.spawn.find_executable('readelf')
+        return shutil.which('readelf')
 
     def __init__(self, static_lib):
         """
         Initialize the readelf executable and flags that will be used to
         extract symbols from shared libraries.
         """
         self.tool = self.find_tool()
         if self.tool is None:
class AIXDumpExtractor(object):
      AIXDumpExtractor - Extract symbol lists from libraries using AIX dump.
      """
 
      @staticmethod
      def find_tool():
          """
          Search for the dump executable and return the path.
          """
-         return distutils.spawn.find_executable('dump')
+         return shutil.which('dump')
 
      def __init__(self, static_lib):
          """
          Initialize the dump executable and flags that will be used to
          extract symbols from shared libraries.
          """
          # TODO: Support dump for reading symbols from static libraries
          assert not static_lib and "static libs not yet supported with dump"

libcxx/utils/libcxx/sym_check/util.py

 #===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #
 #===----------------------------------------------------------------------===##
 
 from pprint import pformat
 import ast
-import distutils.spawn
 import re
+import shutil
 import subprocess
 import sys
 
 
 def read_syms_from_list(slist):
     """
     Read a list of symbols from a list of strings.
     Each string is one symbol.
for sym in out_list:
         out_str += pformat(sym, width=100000) + '\n'
     if out is None:
         sys.stdout.write(out_str)
     else:
         with open(out, 'w') as f:
             f.write(out_str)
 
 
-_cppfilt_exe = distutils.spawn.find_executable('c++filt')
+_cppfilt_exe = shutil.which('c++filt')
 
 
 def demangle_symbol(symbol):
     if _cppfilt_exe is None:
         return symbol
     result = subprocess.run([_cppfilt_exe], input=symbol.encode(), capture_output=True)
     if result.returncode != 0:
         return symbol