[lldb] Use shutil.which instead of distutils find_executable

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

It was added in Python3.3 but given that we're already using
shutil.which elsewhere I think this is ok/no worse than before.

We do have our own find_executable in lldb/test/Shell/helper/build.py
but I'd rather leave that as is for now. Also we have our own versions
of which() but again, a change for another time.

This work is part of #54337.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D124601

lldb/packages/Python/lldbsuite/test/lldbtest.py

@@ -49,7 +49,6 @@
 import sys
 import time
 import traceback
-import distutils.spawn
 
 # Third-party modules
 import unittest2
@@ -1568,7 +1567,7 @@ def findBuiltClang(self):
 
         # Tries to find clang at the same folder as the lldb
         lldb_dir = os.path.dirname(lldbtest_config.lldbExec)
-        path = distutils.spawn.find_executable("clang", lldb_dir)
+        path = shutil.which("clang", path=lldb_dir)
         if path is not None:
             return path
 

lldb/test/Shell/lit.cfg.py

@@ -12,7 +12,6 @@
 from lit.llvm import llvm_config
 from lit.llvm.subst import FindTool
 from lit.llvm.subst import ToolSubst
-from distutils.spawn import find_executable
 
 site.addsitedir(os.path.dirname(__file__))
 from helper import toolchain
@@ -121,7 +120,7 @@ def calculate_arch_features(arch_string):
 if config.lldb_enable_lzma:
     config.available_features.add('lzma')
 
-if find_executable('xz') != None:
+if shutil.which('xz') != None:
     config.available_features.add('xz')
 
 if config.lldb_system_debugserver: