[cfi] Mark a test as unsupported on darwin.
// This test uses jump tables containing PC-relative references to external
// symbols, which the Mach-O object writer does not currently support.
-// XFAIL: darwin
+// The test passes on i386 Darwin and fails on x86_64, hence unsupported instead of xfail.
+// UNSUPPORTED: darwin
#include <stdlib.h>
#include <stdio.h>
