bpo-38453: Resolve test directories before chdir to them (GH-16723)

(cherry picked from commit d83fc27)

Co-authored-by: Steve Dower <[email protected]>

Author: miss-islington

Lib/test/support/__init__.py

@@ -1066,7 +1066,7 @@ def change_cwd(path, quiet=False):
     """
     saved_dir = os.getcwd()
     try:
-        os.chdir(path)
+        os.chdir(os.path.realpath(path))
     except OSError as exc:
         if not quiet:
             raise