Fix test case to work on non-ObjC targets.

Author: rjmccall

test/IRGen/enum.sil

@@ -2441,8 +2441,10 @@ struct ContainsUnownedObjC {
   unowned let x: C
 }
 // CHECK-LABEL: define {{.*}} @optional_unowned() {{.*}} {
-// CHECK-64:      ret { [[WORD]], [[WORD]], i1 } { [[WORD]] 0, [[WORD]] 0, i1 true }
-// CHECK-32:      ret { [[WORD]], [[WORD]], i1 } { [[WORD]] 0, [[WORD]] 1, i1 true }
+// CHECK-objc-64:     ret { [[WORD]], [[WORD]], i1 } { [[WORD]] 0, [[WORD]] 0, i1 true }
+// CHECK-native-64:   ret { [[WORD]], [[WORD]] } { [[WORD]] 0, [[WORD]] 2 }
+// CHECK-objc-32:     ret { [[WORD]], [[WORD]], i1 } { [[WORD]] 0, [[WORD]] 0, i1 true }
+// CHECK-native-32:   ret { [[WORD]], [[WORD]] } { [[WORD]] 0, [[WORD]] 1 }
 sil @optional_unowned : $@convention(thin) () -> (Optionable<ContainsUnowned>, Optionable<Optionable<ContainsUnowned>>) {
 entry:
   %a = enum $Optionable<ContainsUnowned>, #Optionable.None!enumelt