Specify that this works for Darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72899 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/FrontendC/2009-05-04-EnumInreg.c b/test/FrontendC/2009-05-04-EnumInreg.c
index 5619c0a..309be74 100644
--- a/test/FrontendC/2009-05-04-EnumInreg.c
+++ b/test/FrontendC/2009-05-04-EnumInreg.c
@@ -1,6 +1,6 @@
 // RUN: %llvmgcc -S -m32 -mregparm=3 %s -emit-llvm -o - | grep {inreg %action}
 // XFAIL: *
-// XTARGET: x86
+// XTARGET: x86,darwin
 // PR3967
 
 enum kobject_action {