Weaken test to pass on platforms without ObjC interop.

I don't know if there's a more direct way to conditionalize
the FileCheck test here.

Author: rjmccall

test/IRGen/type_layout_reference_storage.swift

@@ -20,8 +20,10 @@ struct ReferenceStorageTypeLayout<T> {
   weak            var cwi: C!
 
   // -- Open-code layout for protocol types with witness tables.
-  // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_16_8_[[REF_XI:[0-9a-f]+]], i32 0, i32 0)
-  // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_8_4_[[REF_XI:[0-9a-f]+]], i32 0, i32 0)
+  //   Note that the layouts for unowned(safe) references are
+  //   only bitwise takable when ObjC interop is disabled.
+  // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_16_8_[[REF_XI:[0-9a-f]+]]{{(,|_bt,)}} i32 0, i32 0)
+  // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_8_4_[[REF_XI:[0-9a-f]+]]{{(,|_bt,)}} i32 0, i32 0)
   unowned(safe)   var ps:  P
   // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_16_8_[[REF_XI]]_pod, i32 0, i32 0)
   // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_8_4_[[REF_XI]]_pod, i32 0, i32 0)
@@ -33,8 +35,8 @@ struct ReferenceStorageTypeLayout<T> {
   // CHECK-32: store i8** getelementptr inbounds ([3 x i8*], [3 x i8*]* @type_layout_8_4_[[WEAK_XI]], i32 0, i32 0)
   weak            var pwi: P!
 
-  // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_24_8_[[REF_XI]], i32 0, i32 0)
-  // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_12_4_[[REF_XI]], i32 0, i32 0)
+  // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_24_8_[[REF_XI]]{{(,|_bt,)}} i32 0, i32 0)
+  // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_12_4_[[REF_XI]]{{(,|_bt,)}} i32 0, i32 0)
   unowned(safe)   var pqs:  protocol<P, Q>
   // CHECK-64: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_24_8_[[REF_XI]]_pod, i32 0, i32 0)
   // CHECK-32: store i8** getelementptr inbounds ([4 x i8*], [4 x i8*]* @type_layout_12_4_[[REF_XI]]_pod, i32 0, i32 0)