bpo-40112: distutils test_search_cpp: Fix logic to determine if C compiler is xlc on AIX (GH-19225) (GH-19444)

(cherry picked from commit 76db37b1d37a9daadd9e5b320f2d5a53cd1352ec)

Co-authored-by: Michael Felt <aixtools@users.noreply.github.com>
1 file changed