gh-110756: Fix libregrtest clear_caches() for distutils

Restore code removed by recent sync with the main branch which no longer has distutils: commit 26748ed.
python · vstinner · Oct 17, 2023 · Oct 17, 2023 · Oct 17, 2023 · 7d7dc7ae05a281eb0c67a2b68d789174ced024fd
commit 7d7dc7ae05a281eb0c67a2b68d789174ced024fd
diff --git a/Lib/test/libregrtest/utils.py b/Lib/test/libregrtest/utils.py
@@ -184,6 +184,15 @@ def clear_caches():
         if stream is not None:
             stream.flush()
 
+    # Clear assorted module caches.
+    # Don't worry about resetting the cache if the module is not loaded
+    try:
+        distutils_dir_util = sys.modules['distutils.dir_util']
+    except KeyError:
+        pass
+    else:
+        distutils_dir_util._path_created.clear()
+
     try:
         re = sys.modules['re']
     except KeyError: