Reapplying the changes from r158717 as they were rolled back to avoid merge conflicts from a separate problematic patch.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158750 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/ms-declspecs.c b/test/CodeGen/ms-declspecs.c
index d3235ae..91862a7 100644
--- a/test/CodeGen/ms-declspecs.c
+++ b/test/CodeGen/ms-declspecs.c
@@ -1,5 +1,13 @@
 // RUN: %clang_cc1 -triple i386-pc-win32 %s -emit-llvm -fms-compatibility -o - | FileCheck %s
 
+struct __declspec(align(16)) S {
+  char x;
+};
+union { struct S s; } u;
+
+// CHECK: @u = {{.*}}zeroinitializer, align 16
+
+
 // CHECK: define void @t3() nounwind noinline naked {
 __declspec(naked) void t3() {}